Juvenile delinquency Assignment Example | Topics and Well Written Essays - 250 words

Juvenile delinquency - Assignment Example Girls are also expected to refrain from fighting or engaging in other such unladylike behaviors. These behaviors, to a large extent, affect how boys and girls will behave when they are adults (Parker, 76). While there are a number of men that have psychopathic personalities, the vast majority of criminals became that way because they were influenced by an erroneous view of what represents true masculinity back in their impressionable childhood years. The effect of single motherhood on teenage delinquency. Children who grow up in homes where only the mother is present are usually confronted with conflicting feelings that they may not have the mental capacity to solve. In addition, there is less parental supervision of their activities because their mothers are usually too busy trying to provide for them to adequately supervise them. This means that they are presented with more opportunities to engage in delinquent behaviors. It is also a fact that single parents try to befriend their children and unintentionally use them as supporters instead of acting as parents and disciplining them when the need arises. This means that even when they have the chance to, they are not likely to reprimand their children for wrong or irresponsible behavior because they want their children to like them so

Coldplay Essay Example for Free

Coldplay Essay British alternative rock band formed in 1996 by lead vocalist Chris Martin and lead guitarist Jonny Buckland at University College London. [3] After forming Pectoralz, Guy Berryman joined the group as a bassist and they changed their name to Starfish. [4] Will Champion joined as a drummer, backing vocalist, and multi-instrumentalist, completing the line-up. Manager Phil Harvey is often considered an unofficial fifth member. [5] The band renamed themselves Coldplay in 1998,[6] before recording and releasing three EPs; Safety in 1998, Brothers Sisters as a single in 1999 and The Blue Room in the same year. The latter was their first release on a major label, after signing to Parlophone. [7] They achieved worldwide fame with the release of the single Yellow in 2000, followed by their debut album released in the same year, Parachutes, which was nominated for the Mercury Prize. The bands second album, A Rush of Blood to the Head (2002), was released to favourable reviews and won multiple awards, including NMEs Album of the Year, and has been widely considered the best of the Nelson-produced Coldplay albums. Their next release, XY, the best-selling album worldwide in 2005, was initially met with mixed reviews upon its release. However, the bands fourth studio album, Viva la Vida or Death and All His Friends (2008), was produced by Brian Eno and released again to largely favourable reviews, earning several Grammy nominations and wins at the 51st Grammy Awards. [8] In August 2011, they announced that a fifth studio album, titled Mylo Xyloto, would be released on October 24, 2011. The band has won a number of music awards throughout their career, including six Brit Awards — winning Best British Group three times, four MTV Video Music Awards, and seven Grammy Awards from twenty nominations.

The Outsiders :: essays research papers

"The Outsiders" is a story that deals with a conflict between two gangs, the "Greasers" from the East Side of town and the "Socs" from the east-side of town. This is a story that is told in the first person. Ponyboy Curtis is the one telling the story. Here is a summary of the story. Ponyboy has a dispute with his brother Darry and ends up running away to the park with Johnnycake. There, Ponyboy and Johnnycake get into a fight with Randy, Bob, and three other members of the Socs. The Socs try to down Ponyboy, so Johnnycake stabs Bob with a knife and ends up killing him. Ponyboy and Johnnycake run to a party where they meet up with Dallas, one of their close friends. He gives them a gun, money, and tells them to get a train out of town to an abandoned church. They are told to stay there until Dallas comes to get them. When Johnnycake and Ponyboy get the church they go right to sleep. When Ponyboy wakes up, he finds that Johnny has gone to the store to get them food. While there, they both decide to disguise themselves by cutting their hair. Ponyboy decides to bleach his hair with peroxide. Dallas finally shows up to get them. They all go to town to get something to eat. When they return to the church, it was on fire. Ponyboy and Johnnycake went in to save the children from the burning church. Johnnycake is trapped inside. Dallas goes into save him. Then, the church collapses. They are rushed to the hospital. Ponyboy and Dallas are okay, but Johnny is severely injured. Ponyboy talks with one of the Socs and they both discuss about how they are tired of fighting. Everyone should be equal. Later, the Greasers and Socs get into an enormous brawl , but in the end the Greasers win. Ponyboy and Dallas rush to the hospital to tell Johnnycake they won the brawl. Johnnycake tells Ponyboy to stay gold. Those are the last words Johnny spoke before he died. Darry goes crazy over Johnny's death and decides to rob a convenience store. The cops chase him, Dallas fires a few shots at them with his gun.

Napoleon’s Buttons

The motivation behind each endeavors goals could have been the use for good, wealth, money, or prosperity. The chemistry of the compound is related to their usage and motive for obtaining them because molecules can control the trade and use of one specific area of the world. Some major molecules that were valued are phenol, Suppression, silk, cellulose, and glucose. Phenols were used as antiseptics during surgery to prevent cuts and wounds from getting infected. Suppression, which is rubber, has been made into countless everyday items that we use to this day.Silk is one of the most valued fabrics in the world. Silk is very hard to harvest and it is expensive. Cellulose is the main component of cotton. Cotton is cheap and most of our clothes are made out of it today but it has fueled slavery for most of the 18th and 19th centuries. Glucose is our everyday sweetener that is always at hand but this has also been a product of slavery during the same time period of cotton. All of these mo lecules have been valued at some point or another. Each molecule here has been a product of someone's endeavor to gain some sort of goal. . Serendipity Is the occurrence and development of events by chance In a happy or beneficial way. A decent majority of chemical discoveries are serendipitous, either by means of trying to create artificial chemicals, failing and creating something accidental, or just by plain dumb luck. Most of the discoveries and expansions of intro compounds has to do with luck. One account of pure randomness is when Christian Frederica Such ¶been spilled a mixture of nitric acid and sulfuric acid on his wife's apron.When he hung it to dry, he had converted the cellulose in the apron as an internal source of oxygen; when heated, it exploded. Phenols also had a high probability in chance. Joseph Leister covered a clothe in phenols as an antiseptic which worked almost every time in use. This led to the cleanliness for germ-free techniques In surgery. Suppression , or rubber, Is another discovery with luck by Its side. If a Christopher Columbus hadn't gone to the new world and brought back rubber a lot of our everyday Items wouldn't exist.Charles Macintosh also discovered a waste product from a local gas works that could convert rubber into a fabric. This fabric is a very useful item in our lives, for its waterproof qualities. Wonder drugs have come a long way in past couple of centuries, from herbs to pills. Without these painkillers, many would have suffered or even died. Chlorination compounds have kept our food fresh and spoil free for decades. CIFS have refrigerated items across oceans and continents and kept them from rotting, which could have been detrimental to sailors in the 19th century.All of these chemical discoveries had some type of serendipitous involvement in our world for good and beneficial reasons. 3. â€Å"With great power comes great responsibility. † In some cases, the men In charge began to neglect their moral p ower of the Industry. During the process of making silk In the early 20th century, the corporations used child labor. The children could get in places could not, sanitary or unsanitary. The children got very little or no infectious diseases and had deformed backs.Today in the world, Japanese corporations treat their workers the same: low pay and poor working conditions. Slavery was another big issue once the trading of sugar began. When sugar plantations began in the new world, we enslaved innocent Africans to work on the plantations. The slaves had to work from the break of dawn till the sun set. Slaves were beat if they didn't obey the master's rules and they poor living conditions. Today in Africa children are tricked into being enslaved to work on cocoa plantations just as slaves did two hundred years ago.

Theoretical Considerations Regarding Hazards And Risks Environmental Sciences Essay

The cognition of natural and technological hazards is of the extreme importance for carry oning hazard and impact appraisal surveies, every bit good as land usage planning and exigency response planning. This whole mechanism significantly contributes to the society ‘s sustainable development. For the overall comprehension of this issue, it is extremely relevant to specify the repeating constructs of this work, viz. jeopardy and hazard.The jeopardy constructTo get down with, a short ethimological analysis of the word â€Å" jeopardy † is necessary. This term has been taken by the Gallic from Arabic, where it means dice game ( Mac and Petrea, 2002 ) . Harmonizing to the Longman Dictionary of Contemporary English, 2010, † jeopardy † means â€Å" something that may be unsafe, or cause accidents or jobs † . In 1992, the United Nations International Decade for Natural Disaster Reduction secretariat published a multilingual lexicon so as to clear up and unite the significances of such footings. In this dictionary, jeopardy is defined as â€Å" a baleful event or the possibility for a phenomenon with destructive potency to look in a individual part and in a given period of clip † . Another definition is offered by the Grand Larousse Dictionary, volume V, cited by ZA?voianu and Dragomirescu in 1994: â€Å" accidental and, by and large, unforeseeable interface between two or more causal series, whose common dealingss are purely defined in every minute and whose comparative independency can merely be attributed to our ignorance and impotence † . Scheidegger, 1994, cited by ArmaAY , 2003 defined jeopardy as â€Å" the chance of rapid alteration of a system ‘s province or stable conditions † . In 1997 Grecu defined this construct as â€Å" the possibility that a potentially annihilating phenomenon appears in a certain period of clip and in a certain part. † In 1999 Octavia Bogdan and Elena Niculescu specify jeopardy as â€Å" a random phenomenon on a big graduated table, unpredictable, a deficiency of finding between clip and infinite, a qualitative lap, a threshold in the system ‘s development, downloading immense energy and doing upset, instability on the natural environmental development ‘s graduated table, in its manner towards a new province of equilibrium † . In 2000 Ozunu defines the construct under treatment as aˆza state of affairs with the potency of an accident † ; in 2001, BA?lteanu states that jeopardy is aˆza endangering event, stand foring the possibility for a potentially detrimental phenomenon to go on. † Harmonizing to him, harm to people, goods and the environment occur. Alexander, 2000, cited by Thywissen, 2006, defines hazard as aˆzan utmost geophysical event that can do a catastrophe. aˆsExtreme ‘ refers to an either positive or negative characteristic, harmonizing to the tendency it is related to. The jeopardy ‘s cardinal properties are: location, clip, magnitude and frequence. Many utmost phenomena are perennial in clip and predictable in footings of location. We define hazard as an utmost event arising from the biosphere, lithosphere, hydrosphere or atmosphere. † Mac, 2003, considers hazard as aˆzthe beginning of an utmost event with energy discharge in a certain minute and with a instead unforeseeable magnitude. In fact, jeopardy can be referred to as aˆza phenomenological class that refers to objects and phenomena ( air multitudes, H2O, lithomass, biomass, people, twisters, epidemics, temblors, avalanches etc. ) , to their actions ( inundations, clay flows, landslides, illness etc. ) every bit good as to their characteristics † ( Mac, 2003 ) . In 2003, Cardona, cited by Thywissen, 2006, offers another definition of the term: aˆzthe possibility for a natural and unsafe event to go on in a certain clip and infinite † . Generally, the construct of jeopardy is used to mention to a latent danger or to an external hazard factor of a system or exposed capable. A jeopardy is composed of three basic elements ( C. A. Ericson, 2005 ) : 1. Dangerous belongings – the basic beginning of the danger that creates the jeopardy, i.e. a unsafe energy beginning etc. 2. Initiation mechanism – the event that triggers or initiates the happening of the jeopardy, transforming the jeopardy from a inactive province to an active 1. 3. Target and menace – the individual, object, state of affairs vulnerable to damage caused by the materialisation of the jeopardy. These three elements compose the jeopardy trigon shown in figure 2.1: Figure 2.1 – The jeopardy trigon ( C. A. Ericson, 2005 ) The jeopardy trigon illustrates that all three above mentioned are interlinked. All three constituents are necessary in order to organize a jeopardy. The remotion of one portion of the trigon consequences in the riddance of the jeopardy, because it can non take to an incident. By extenuating the induction mechanism the chance of the incident to happen is reduced, and accordingly by extenuating an component of the unsafe belongings or mark and menace the badness of the incident will be reduced. These theoretical facets and categorization prove to be important in any undertaking refering jeopardy designation, extenuation, and hazard and impact appraisal. The basic construct of jeopardy theory can be summarized as follows ( C. A. Ericson, 2005 ) : Hazards are deterministic entities and non a random 1s ; Hazards are constituted accidentally in systems ; Hazards are predictable and hence can be controlled and prevented ; Hazards can be identified by their constituents ; Hazards will happen taking history of the constituents involved ; Hazards consequence in incidents. One of the term ‘s most recent definitions is the 1 offered in 2009 by the International Strategy for Disaster Reduction Secretariat: â€Å" a unsafe phenomenon, substance, human activity or status that may do loss of life, hurt or other wellness impacts, belongings harm, loss of supports and services, societal and economic break, or environmental harm. † As it can be noticed from the above-named definitions, jeopardy is characterized through certain parametric quantities, such as geographical location, strength ( magnitude ) , frequence and its chance to go on. In many of these definitions, one can detect the accent lies upon entropy, deficiency of determinacy and capriciousness ( Mac 2003 ) . In order to measure these phenomena ‘s possibility to go on, surveies refering their extreme values are considered. Furthermore, in all these definitions the construct of jeopardy has a instead negative intension, since it implies a certain grade of danger. Hazard can take the signifier of some remarkable phenomena or of some combines 1s, in footings of infinite and clip. Hazard appraisal purposes at identifying: the likeliness of a specified jeopardy to go on in the hereafter, in a certain period of clip, its magnitude and impact country ( Pine, 2009 ) . For the appraisal of certain jeopardies such as inundations, temblors and vents there are good established, predefined methods. The consequences of these ratings are extremely relevant in footings of lucubrating land usage planning schemes and in implementing accident bar steps.Hazard vs. hazardThe term â€Å" jeopardy † is closely related with the term â€Å" hazard † . Not few are the instances when confusion arises between the significances of these two constructs. This is why it is necessary to separate between them. Hazards are phenomena whose manifestations can barely be predicted and controlled. They have negative effects on population and on the environment. Imputing the characteristic of jeopardy to a natural or anthropic phenomenon is non conditioned by the production of mater ial harm or by the being of victims, but by the potency of these effects to go on. ( Baldea, 2007 ) . Merely when that jeopardy or phenomenon exceeds certain critical values, taking to material harm or casualties, does it go hazard. Therefore, a jeopardy is the menace that an event might go on and non the event itself. Should it impact a human community, to a certain extent, it becomes hazard. It must be mentioned that the term â€Å" hazard † is attributed assorted significances, being used in different contexts. Its definitions have societal, economic, political and environmental values. In order to better understand its deductions, a short diachronic analysis is necessary. To get down with, the term under treatment was foremost used in the fifteenth century, when it referred to the trade ‘s fiscal danger ( Proske, 2008 ) . Initially, this construct was associated with economic activities, being so used in the theory of chance and gaming. In the nineteenth century it is integrated in economic system, experiential doctrine and determination theory, whereas in the twentieth century it was used as political term in atomic engineering in order to gauge the degree of security that was acceptable for people. Until the 8th decennary of the old century constructs such as hazard, jeopardy and hazard direction were associated with natural phenomena. Hazard and natural or anthropic jeopardies analysis became an interdisciplinary kingdom of survey with its specific nomenclature merely in the last 30 old ages. The Longman Dictionary for Contemporary English, 2010, defines hazard as â€Å" the possibility that something bad, unpleasant, or unsafe may go on † . In 2007 ISDR defines hazard as â€Å" the combination of the chance of an event and its negative effects † . In 1999 Octavia Bogdan and Elena Niculescu define hazard as â€Å" the existent chance or possibility for a phenomenon to go on † . This event is someway expected and has negative reverberations, in response to which world can merely be inactive. Another definition is offered by Ozunu in 2000: â€Å" the chance that the existing jeopardy turns into an accident † . Alwang, 2001, cited by Thywissen, 2006, defines hazard as â€Å" the possible distribution of some known or unknown events. These are characterized by magnitude, frequence, continuance and history † . In the same twelvemonth, Peduzzi, cited by Brauch, 2005, considers risk aˆza step of possible losingss generated by a jeopardy of a certain magnitude, produced in a certain part and period of clip † . It must be stated that natural events can turn into social hazards when they surpass the immediate capacity of being counteracted or absorbed. They are, in most of the instances, utmost events. An utmost natural event is any event or series of events that shows a fleeting or durable fluctuation as compared to its common values. ( White, cited by ArmaAY , 2003 ) The widely accepted definition of hazard as the merchandise between the chance for an event to go on and the negative effects it may hold is expressed as follows: R= F x C ( Eq. 2.1 ) where: R- hazard ( losses/unit of clip ) , F- frequence of happening ( no. of events/unit of clip ) , C- effects ( losses/event ) . Hazard can besides be defined as â€Å" the chance of human exposure, of semisynthetic goods and of the environment to the action of a jeopardy of a certain magnitude and their exposure towards it † ( BA?lteanu, 2005 ) . For Petrea, 2009, hazard is â€Å" the possibility that some negative effects for human communities or losingss ( human lives, hurts, diminished agencies of subsistence, goods, harm of the environmental constituents ) appear as an interaction between natural or anthorpic jeopardies and territorial exposure † . This expression associates two distinguishable elements, viz. the jeopardy and the receiving system ( in most of the instances, a certain population ) . In most of the instances, the undermentioned expression is used: R= Hazard x Vulnerability ( Eq. 2.2 ) This underlines the relation between an event and its effects. In a certain country, the hazard is comparatively changeless. What differs is community exposure, in footings of its reaction to menaces or its degree of readiness to confront them. Harmonizing to the above-named expression, hazard may match to a high-frequency jeopardy and a low exposure or to a low-frequency jeopardy and high exposure. The disadvantage of this expression is that it does non see the population denseness, i.e. its exposure to hazard. Mitchell, 1990, cited by Brauch, 2005, completes this expression, sing jeopardy as a map of hazard, exposure, exposure and response: Hazard= degree Fahrenheit ( hazard ten exposure x exposure x response ) ( Eq. 2.3 ) where: hazard – the chance that negative effects appear, exposure – the size and characteristics of the open population, exposure – the potency of harm to bring forth and response refers to the enforced steps for hazard decrease. Another definition is given by Ozunu and Anghel in 2007: R = F x C x V ( Eq. 2.4 ) where: R – hazard ; F- frequence ; C – effects ; V- exposure ( – ) . The harm produced as a consequence of a catastrophe is really the consequence of the interaction among physical environmental factors ( clime, H2O, landscape etc. ) , population ( societal categories, civilization etc. ) and the built environment ( edifices, substructure etc. ) ( Mileti, 1999 ) . Therefore, jeopardy can be considered the pre-disaster state of affairs, when hazard does non look. A phenomenon ‘s development has three phases, more precisely: the jeopardy one, when merely hazard appears, the hazard phase, when jeopardy can impact human society and, eventually, the catastrophe. ( Alexander, 1993 ) In decision we can province that there are two types of hazards, viz. an acceptable one, where losingss are tolerable for the population and catastrophe, when losingss can non be tolerated by the local community.Categorization of jeopardies and hazardsAs antecedently mentioned, jeopardies and hazards are defined and characterized in multiple ways. In this chapter, a categorization is presented harmonizing to the most relevant features: beginning, effects, frequence, affected surface, etc.Categorization after beginningThe categorization of jeopardies harmonizing to their beginning is presented in table 2.1: Table 2.1 – Categorization after beginning ( BA?lteanu, 2005 ) :Natural jeopardiesEndogenousVolcanic eruptions, seismicityExogenousClimatic Cyclones, twister, storms, lightning, hail, hoar, drouth, etc. Geomorphologic Mass supplanting, eroding Hydrologic Flash-floods Oceanographic Rise of planetal ocean, El Nino Biological Epidemics, viruses, insect invasionsAnthropogenetic jeopardiesTechnologicalIndustrial, agricultural, transport accidentsHuman( Benedek, 2002 ) Social Poverty, unemployment, urbanisation, life style Medical Infectious, viral, chronic, degenerative diseases Demographic Emigration, population growing, aging of population Political Territorial, political differences2.3.2 Classification harmonizing to the manifestation mannerThe categorization of jeopardies harmonizing to their manifestation manner is presented in table 2.2 ( GoA?iu and Surdeanu, 2008 ) : Table 2.2 – Hazards categorization harmonizing to their manifestationViolent jeopardies– temblors – vents – severe storms, twister, etc. – local storms with hail etc. – catastrophic landslides, avalanchesHazards with progressive development– Mediterranean disturbances ( Mediterranean cyclones with retrograde development )Hazards with slow development– drouth – severe drouth – radiation and vaporization mists2.3.3 Categorization after continuanceHazards can besides be classified harmonizing to their temporal development. Harmonizing to ArmaAY , 2008 the categorization after the continuance of jeopardies is presented in table 2.3: Table 2.3 – Hazards categorization harmonizing to their continuanceWith sudden happening and rapid developmentEndogenous, tectonic jeopardies, sudden mass supplantings, flash – inundationsWith long continuanceTerrain debasement, drouths, desertification2.3.4 Categorization after affected surface, and continuance of effectsHazards can endanger assorted extents of a district. Within the affected surface the effects can prevail for assorted sums of clip. Harmonizing to Chardon, 1990 and Grecu, 1997 a categorization after the affected surface and the continuance of effects is presented in table 2.4: Table 2.4 – Hazards categorization harmonizing to affected surface and continuance of effectsCalamity typeAffected surfaceDuration of effectsExamplesGiga calamity100 – 510 mil. km2 several old ages volcanic eruptionsMega calamity1 – 100 mil. km2 several months big temblors volcanic eruptions tropical drouthsMeso calamity10.000 – 1.000.000 km2 several hebdomads – a few months volcanic eruptions temblors, cold moving ridges tropical stormsCalamity100 – 10.000 km2 a few hebdomads little temblors, twister exceeding rainsLocal phenomenaunder 100 km2 a few yearss – a few hebdomads landslides hail storms The present thesis focuses on the appraisal with optoelectronic engineerings of two major jeopardies from the above mentioned categorizations: Natural jeopardies – volcanic ash by active and inactive remote feeling Technological jeopardies – monitoring and patterning the impact of SO2 emanations associated with big burning workss.NATECH jeopardiesThis thesis focuses both on natural and anthropogenetic jeopardies individually. In order to develop efficient schemes for measuring hazards and impact, the NATECH ( natural jeopardies which trigger technological accidents ) rule is necessary to be considered when measuring either of the two above mentioned types of jeopardy. Current EU ordinances in the field of hazard appraisal and catastrophe direction ( European Commission, 2010 ) stress the necessity of a multi-risk and multi-hazard attack in all natural and anthropogenetic jeopardy and hazard surveies. Therefore, there is a turning involvement in the scientific community and among stakeholders sing natural jeopardies which trigger technological accidents ( NATECHs ) . NATECHs have important negative effects on human wellness, the environment and the economic system. The addition in the figure of such events is closely linked with the exponential technological development of the past decennaries, due to the variegation of engineerings, the turning figure of personal exposed, and the substances used in the technological procedures. The effects of NATECH events have become more terrible within this timeframe chiefly due to the exposure of the population life near these installations. Given these facts, there is an pressing demand for raising consciousness about bar and readiness steps refering these high effect low chance events ( Cruz and Okada, 2008 ) . Due to the complexness of NATECH events, their word picture is instead hard, and many NATECHs are analyzed and assessed as separate natural or technological events ( Embelton and Embelton-Hamann, 1997 ) . One needs to take into history that the effects of such an event differ in complexness from the effects of the two events taken individually ( Cruz and Krausmann, 2008 ) . Therefore, there is a demand for scientific research on the interactions and dealingss between natural jeopardies and technological accidents. Addressing NATECHs requires a combined attempt of industrial and technological hazard direction specializers working together with specializers concentrating on natural jeopardy probes. The specific features of a NATECH event ( Domino impacts, multiple effects ) need specific steps for the bar, response and recovery after such an event. An integrated hazard and impact direction scheme must include the possibility of NATECHs to happen, and necessitate specialised planning for extenuation, response, and recovery ( Ozunu et al. , 2011 ) The Activities Report On the Collaboration Agreement between the International Strategy for Disaster Reduction of the United Nations and the Directorate General Joint Research Center of the European Commission proposes a scheme for the extenuation of NATECH events by: iˆ Industry hazard direction specifically turn toing the possible impacts of natural jeopardies on technological installings. Additional hazard direction processs ( Figure 2.2 ) in order to cut down the exposure to NATECHs: the usage of excess safety systems, natural jeopardy resistant designs, guidelines to inform industry about NATECH planning, and strategic arrangement of risky substances inside a unit. Figure 2.2 – Catastrophe Management processs ( Torok et al. , 2009 ) Efficient Emergency planning, including bar and extenuation, and response planning for NATECHs at all degrees of authorities. The purpose of the Risk Analysis procedure is to cut down uncertainnesss by increasing safety degrees by developing more efficient Emergency Plans, offering immediate determinations, detailed, accurate and steady instructions ( ( Torok et al. , 2009 ) iˆ Land usage planning, as an of import tool for setting-up insularity margins in order to protect occupants populating near risky installations. ( Christou et al.,2006 quoted by Torok et Al. 2011c ) . Article 13 of the SEVESO III Directive ( Directive 2012/18/EU ) provinces that: â€Å" Member States shall guarantee that the aims of forestalling major accidents and restricting the effects of such accidents for human wellness and the environment are taken into history in their land-use policies or other relevant policies † Information and instruction of the populace, authorities bureaus and all stakeholders involved in exigency direction, including decision-makers. iˆ Public engagement in NATECH hazard decrease planning, in order to better understand the perceptual experience of the degree of the NATECH hazard and the degree at which this hazard is considered acceptable ( Ozunu et al. , 2011 )Qualitative and quantitative methods for placing jeopardies and measuring hazardsA systematic designation of possible environmental impacts atmospheric pollutants have, every bit good as a strict analysis of their magnitude is required. The intent of such a procedure can be divided in two major issues, on one manus to bring forth quantitatively accurate appraisal of peculiar hazard and a comprehensive list of possible environmental impacts, and on the other manus produce a principle for doing public policy determinations that is both good reasoned, and recognized as legitimate and acceptable by the socio-economical factors. A complex environmental impact appraisal ( EIA ) and hazard appraisal ( RA ) methodological analysis requires assorted sets of informations about beginning footings, emanations, imissions, exposure, local weather forecasting, terrain informations etc.. Most of the air scattering theoretical accounts have been developed for the anticipation of lee concentration of air pollutants and for the appraisal of short-run and medium-term effects of these pollutants. The quality of consequences obtained utilizing these patterning systems depend largely on the versatility and quality of input informations and the right pick of the theoretical account ( Torok et al. , 2011a ) . In instance of EIA surveies, the medium-term effects appraisal requires emanation and meteoric informations for several months in order to obtain a realistic distribution of the largely contaminated countries. The consequence of the complex terrain on the air motion in the commixture bed is important. Therefore the meteoric information for the modeling period should be calculated sing the air flow above the complex terrain. For RA, the appraisal of immediate effects of ague exposure requires on-site informations for a short clip period. These informations sets must incorporate information about emitted substances ( type and concentration ) every bit good as real-time local meteorological informations, which along with terrain informations can be used in a rapid environmental and risk appraisal, which is a valuable tool for on-site exigency planning in instance of accidental or deliberated releases of toxic substances in the ambiance ( Torok et al. , 2011a ) . In the field of hazard analysis and hazard appraisal there are differences of sentiment sing the usage of qualitative or quantitative hazard analysis methods. The qualitative-quantitative factor is the basic belongings of jeopardies analyses methods. Most of the analysis methods are developed in order to place jeopardies and to find the hazard of that jeopardy turning into an accident. For finding the accident hazard of the identified jeopardy, a methodological analysis for the word picture of chance and magnitude parametric quantities must be used. There were developed both qualitative and quantitative methods, which are successfully used, each methods holding its specific advantages and disadvantages ( Torok et al. , 2011a ) .Qualitative methods used in jeopardy analysisA qualitative analysis implies the usage of qualitative standards, utilizing different classs for parametric quantities separation, with qualitative definition which set up the graduated table for each class. Besides, qualitative determinations are made, based on the field experience, in order to delegate elements into classs. This attack is subjective, but it allows a higher generalisation grade, being less restrictive.2.5.1.1 Designation of jeopardiesThe designation of technological jeopardies is the basic measure in hazard appraisal procedure. Hazards appear in the industry all the clip, due to the procedure and runing conditions of the installings and the physical, chemical and toxicological belongingss of the substances used in these procedures. This is why it is extremely of import to place the substances ‘ risky belongingss and the operating conditions that put at hazard these procedures, the series of events that may take to the materialisation of a jeopardy. In order to develop an in-depth survey of jeopardies and hazard analysis, the risky belongingss of the substances must be identified and assessed in order to find conditions or non they pose a jeopardy to human life, the environment of the technological procedure. From a qualitative point of position this can be achieved utilizing checklists. A comprehensive checklist used in the appraisal of jeopardies and hazards posed by substances is presented in table 2.5: Table 2.5 – Hazardous belongingss of substances- Checklist ( Hyatt, 2003 )TypePropertyGeneral belongingssMolecular construction Freezing point Melting point Vapour force per unit area Boiling temperature Critical force per unit area Critical temperature Critical volume Density Specific heat Viscosity Thermal conduction Fluid denseness Latent vaporisation heat Dielectric invariable Electric conductionFlammabilityExplosion/ Flammability bounds Explosion threshold Auto ignition temperature Minimal ignition energy OverheatingCorrosionCorrosive for building stuffs Incompatibility with other stuffsPolymerizationDecompositionFeatures of polymerisation Features of decomposition Features of hydrolysisImpuritiesImpurities in equipment stuffs Impurities in substanceChemical reactions, detonationsHeat of formation Heat of decomposition Combustion heat Thermal stableness Resistance to impact Potential energy jeopardiesToxicityExposure bounds: IDLH ; ERPG1-2-3 ; AEGL 1-2-3 ; LC50 and LD50 Exposure effects ( inspiration, consumption, tegument and oculus contact ) Effectss of long-run exposure with little sums Warning bounds ( odor threshold )RadiationRadiation bounds I ± , I? , I? atoms Material toxicity It must be stated that stuff toxicity depends on a series of physical and chemical factors, in the type of contact and on the interaction of substances with beings. The ways in which this penetrates the organic structure are assorted, viz. unwritten ( through the oral cavity, in the tummy ) , cuticular ( toxicity enters the tegument ) or by agencies of inspiration ( through the respiratory system ) . The harmful belongingss of risky substances can be divided into the undermentioned classs ( Ozunu and Anghel, 2007 ) : acute toxicity ( really toxic, toxic, harmful, annoying ) specific belongingss ( allergic, carcinogenic, with consequence on reproduction or familial consequence ) with harmful impact on the environment Whereas the first two classs mentioned supra have direct inauspicious consequence on wellness, the last one acts indirectly on human existences by damaging the environment. The harmful actions start when little sums of substances appear in the organic structure ; should larger sums appear, they can take to one ‘s decease. The most normally used indexs to find substance toxicity are ( Torok et al. , 2011c ) : medium deadly dose- LD50 is the dosage at which half of the experimental population of animate beings ( or worlds, should human deceases be registered ) dice. LD50 index at consumption and at the skin degree is shown in milligram ( mgs ) of substance per kg of animate being organic structure, taking into history a individual disposal. the medium deadly concentration – LC50: concentration for inspiration is measured in mgs of substance per litre of air breathed or in volumetric parts per million -ppm ( exposure clip differs depending on substance toxicity ) the immediate unsafe concentration for life and wellness – IDLH is inspiration with irreversible effects on wellness These bounds of concentration are used as indexs in both the US and the EU statute law ( NIOSH, 2012 ) . The bounds of toxicity for a series of substances are set in the Dangerous Substances Directive 67/548/ EEC. They are grouped harmonizing to some classs presented below. Each type of danger has a hazard phrase ( Rphrase ) consisting of a figure and of the appropriate hazard description ( Ozunu and Anghel, 2007 ; Directive 67/548/ EEC ) . Table 2.6 – LD50 ( unwritten )ClassLD50( mg/kg )SymbolRphraseVery toxic& lt ; 25 T+ R26, R27, R28Toxic25 – 200 Thymine R23, R24, R25Harmful200 – 2000 Xn R20, R21, R25 The current thesis focal points on two major jeopardies, natural 1s, with a instance survey on volcanic ash, and anthropogenetic 1s, with instance surveies on S dioxide ( SO2 ) . Sing volcanic ash, the most serious jeopardies can be associated with its: caustic belongingss on stuffs, i.e. aircraft engines, windscreens, etc. , runing point, the volcanic ash runing inside the turbine due to the high temperatures, and so solidifies in the ice chest parts of the engine s. denseness, the denseness of volcanic ash is comparatively high, dry ash being up to 5 times, wet ash about 20 times denser than snow. This fact represents a major jeopardy to edifices when ash accumulates on the roofs in sufficient measures, taking to prostrations. In the instance of SO2, the major jeopardies are associated with:Quantitative methods used in hazard appraisalQuantitative analysis implies the usage of numerical or quantitative informations and provides quantitative consequences. This attack is more nonsubjective and more precise. It must be mentioned that the quantitative consequences can be extremely affected by the preciseness and cogency of the input parametric quantities. Therefore, the quantitative consequences within the hazard analyses should non be taken into consideration as exact Numberss, but as estimations, with a variable graduated table depending on informations quality ( Torok, 2010 ) .2.4.2.1. ModelingThe representation of world through mold is extremely relevant, since it offers one the possibility to analyze and analyze systems in footings of mathematics and technology. It must be mentioned that a system consists of a set of elements that interact with one another within some bounds. Furthermore, this system has a specific behavior. These bounds are really the 1s that separate the system from the other 1s. These theoretical accounts can be divided into two classs, viz. physical and abstract ( fanciful or mathematical ) theoretical accounts. With respect to the physical theoretical accounts, they describe the system from a physical point of position, utilizing the physical Torahs that apply upon the system under treatment. The mathematical theoretical account of a system describes it in footings of mathematical equations, utilizing simplifying hypotheses. Abstractization works in both ways, i.e. from object to its representation ( theoretical account ) and so back to world. Still, it must be stated that this theoretical account does non picture world all the clip ; it tries to be as closer to it as possible. The more complex a system is, the more complicated the theoretical account becomes. In this context, the purpose of patterning systems and processes utilizing the computing machine is to make a theoretical account that contains a description realistic plenty for the given application. The basic stairss for the accomplishment of a mathematical theoretical account are as follows ( Savii and Savii, 2000 ) : job designation and the pick of variables building of mathematical dealingss among variables utilizing simplifying premises the purchase of information sing the size, importance and interrelatednesss for each variable under treatment the choice of input signals ‘ parametric quantities constitution of province variables proof of premises and dealingss utilizing the right theoretical account harmonizing to the state of affairs.2.4.2.2. SimulationWith the development of information engineering and computation equipment, the scrutiny of theoretical accounts utilizing simulations has become possible. Simulation allows proving those systems ‘ functionality theoretical accounts that have yet to be or are presently in design stage. Simulation is the lone possibility of analyzing the dynamic behavior of such a theoretical account. Discrete simulation, utilizing theoretical accounts of distinct systems, is of great aid for projecting production systems, where issues of optimisation appear ( Savii and Savii, 2000 ) . In the present thesis we focus chiefly on the mathematical mold of the gas pollutants ‘ scattering in the ambiance. Beginning theoretical accounts are used to specify the quantitative emanation scenario of substances by gauging their flow rate, the scattering of substance after release. Dispersion theoretical accounts turn the end products from beginning theoretical accounts into isoconcentration curves specifying concentration countries and cipher the development of concentration in clip. The mass conveyance of molecular-scale fluid occurs through diffusion, with a changeless diffusion velocity throughout its motion. However, unstable scattering is a procedure different from molecular diffusion, since the mass conveyance occurs at assorted scale lengths of the disruptive motion. Disruptive scattering is much more efficient than molecular diffusion. The scattering rate is non changeless ; it depends on the size of the whirl and of that of the cloud of spread pollutant. These whirls can be of different sizes ; on a big graduated table, they determine the motion of the pollutant cloud, whereas on a little graduated table they contribute to its dilution. The energy and size of these whirls determine gas plumes scattering. Their continuance, length and strength are the chief factors that influence this procedure. The mathematical mold of gas pollutants in the ambiance is based on equations of mass, energy and impulse preservation. Such an equation must be established for each pollutant. It represents the fluctuation of atoms ‘ denseness in clip and infinite. From these equations one can acquire a complex system of equations that can be solved by agencies of numerical methods, obtaining the existent behavior of concentration in clip and infinite. A literature reappraisal reveals two chief methods used for picturing the behavior of pollutants released into the ambiance, viz. the Eulerian formalism and the Lagrangian 1. Both methods are used to depict the statistical belongingss of pollutant concentration. The Eulerian formalism starts from ciphering fluid speeds in the ten, Y and omega waies, measured in fixed points in the fluid under treatment. Input information is comparatively easy to obtain from the measuring or mold of discharges, but work outing the mathematical equations system can be really complex, ensuing in inaccurate solutions. Dispersion coefficients can be retrieved utilizing the Pasquill-Gifford graduated table ( Pasquill, 1961 ) . After this, the imission map for a beginning point and meteoric scenario can be developed. The Lagrangian formalism uses the statistical belongingss of some fluid atoms that move passively, freely. As compared to the Eulerian formalism, the mathematical equations system is easier to work out, therefore it is computationally really efficient, and merely the fraction of the sphere really involved in the scattering is simulated. Disruptive procedures are included in the theoretical account in a more natural manner, and there is no important numerical diffusion ( Stohl et al. , 2005 ) . Still, the method ‘s pertinence is limited by the troubles encountered when finding the statistics of fluid atoms. The Lagrangian formalism is applicable upon long-distance scatterings, when the complex topography influences the flow of air-pollutant multitudes. Although the scattering procedure is a typically Lagrangian one, about all information available refering the ambiance are based on Eulerian measurings. Therefore, a relation between the Eulerian belongingss and the Lagrangian 1s is ( widely ) accepted ( Sandu et al. , 2004 ) .

Free Essays on Formalistic Criticism For “Revelation”

Formalistic Criticism for â€Å"Revelation† Formalistic critics often analyze stories by showing the relationship between various elements’ meanings such as: plot, characters, point of view, setting tone, diction, images, and symbols. In â€Å"Revelation† the best formalistic approach is about the setting. This factor is used to define the characters in the story. It also gives the reader clues about the time period and geographic location. The protagonist of the story thinks that everyone is defined by his or her outward appearance; the question O’ Connor asks is, â€Å"Should people judge others by superficial things like appearance?† In an attempt to explore the complexity (or hypocrisy) of the class system in the South, O’ Connor uses a well-know setting described in vivid detail and stocked with stereotypical characters speaking local dialect. O’ Connor describes the primary setting in vivid detail. In the first paragraph O’ Connor describes how the doctor’s waiting room is very small and almost full when the protagonist, Mrs. Turpin enters. O’ Connor also mentions that â€Å"when Mrs. Turpin, who was very large, enters she made the room look even smaller† (O’ Connor 338). The setting shows the closeness of all the stereotypical characters makes for a conflict that is inevitable. The room may also represent the protagonist’s small mindedness. Mrs. Turpin is narrow minded because of the way she thinks she is a good person, but yet has inner conflicts. She judges everyone by the way they look. Mrs. Turpin describes one person in particular who demonstrates lower class; as she looked around the room Mrs. Turpin sees â€Å"a woman with a yellow sweatshirt and wine-colored slacks, both gritty-looking, and the rims of her lips were stained with snuff. Her dirty yellow hair was t ied behind with a little piece of red paper ribbon. Worse than niggers any day, Mrs. Turpin thought† (340). Her quick judgment reveals how small... Free Essays on Formalistic Criticism For â€Å"Revelation† Free Essays on Formalistic Criticism For â€Å"Revelation† Formalistic Criticism for â€Å"Revelation† Formalistic critics often analyze stories by showing the relationship between various elements’ meanings such as: plot, characters, point of view, setting tone, diction, images, and symbols. In â€Å"Revelation† the best formalistic approach is about the setting. This factor is used to define the characters in the story. It also gives the reader clues about the time period and geographic location. The protagonist of the story thinks that everyone is defined by his or her outward appearance; the question O’ Connor asks is, â€Å"Should people judge others by superficial things like appearance?† In an attempt to explore the complexity (or hypocrisy) of the class system in the South, O’ Connor uses a well-know setting described in vivid detail and stocked with stereotypical characters speaking local dialect. O’ Connor describes the primary setting in vivid detail. In the first paragraph O’ Connor describes how the doctor’s waiting room is very small and almost full when the protagonist, Mrs. Turpin enters. O’ Connor also mentions that â€Å"when Mrs. Turpin, who was very large, enters she made the room look even smaller† (O’ Connor 338). The setting shows the closeness of all the stereotypical characters makes for a conflict that is inevitable. The room may also represent the protagonist’s small mindedness. Mrs. Turpin is narrow minded because of the way she thinks she is a good person, but yet has inner conflicts. She judges everyone by the way they look. Mrs. Turpin describes one person in particular who demonstrates lower class; as she looked around the room Mrs. Turpin sees â€Å"a woman with a yellow sweatshirt and wine-colored slacks, both gritty-looking, and the rims of her lips were stained with snuff. Her dirty yellow hair was t ied behind with a little piece of red paper ribbon. Worse than niggers any day, Mrs. Turpin thought† (340). Her quick judgment reveals how small...

Free Essays on Odinary Men To Japaness Soldier

â€Å"Ordinary Men† to â€Å"Japanese Soldiers† Iris Chang's "Rape of Nanking" is a book that fails to heal but rather sears all efforts for good international relations because it prioritizes passion at the cost of basic historical facts. While Christopher Browning’s â€Å"Ordinary Men† tells the story of Police Battalion 101, and how they play a role in the Second World War in Europe. Both of these books outline what kinds of items a civilian would be subjected to during wartime. This ranges from persecution, certain death, or to begin made to mobilize to help one country’s war effort. In Brown’s Ordinary men he shows in detail the sequence of events and individual reactions which may turn ordinary men into killers. To understand where the story of these so-called â€Å"ordinary men† there must be an in-depth look taken at why these groups of Reserve Policemen where formed. The Order Police resulted from the third attempt in war enraged Germany to create large police forces with military and equipment. The police force that was created was supposed to work along side the German military to secure lands that the German army has conquered. Before the start of WWII the use of these men had not been thought about, but with the German army quickly advancing someone would have to occupy conquered lands. That is were these Order Police come into play. Police Battalion 101 was used a great deal in Poland. They were subsequently involved in rounding up Polish soldiers cut off behind advancing lines. They also collected military equipment that was abandoned by the retreating Poles, and also providing other services to secure the rear areas. (chap 2 Browning) Another duty that the Order Police were placed with was the collection and deportation of the Jews that occupied Poland. Early in the war they were used in Poland to collect the Jewish people and load then on trains that where headed to the ghettos wer... Free Essays on Odinary Men To Japaness Soldier Free Essays on Odinary Men To Japaness Soldier â€Å"Ordinary Men† to â€Å"Japanese Soldiers† Iris Chang's "Rape of Nanking" is a book that fails to heal but rather sears all efforts for good international relations because it prioritizes passion at the cost of basic historical facts. While Christopher Browning’s â€Å"Ordinary Men† tells the story of Police Battalion 101, and how they play a role in the Second World War in Europe. Both of these books outline what kinds of items a civilian would be subjected to during wartime. This ranges from persecution, certain death, or to begin made to mobilize to help one country’s war effort. In Brown’s Ordinary men he shows in detail the sequence of events and individual reactions which may turn ordinary men into killers. To understand where the story of these so-called â€Å"ordinary men† there must be an in-depth look taken at why these groups of Reserve Policemen where formed. The Order Police resulted from the third attempt in war enraged Germany to create large police forces with military and equipment. The police force that was created was supposed to work along side the German military to secure lands that the German army has conquered. Before the start of WWII the use of these men had not been thought about, but with the German army quickly advancing someone would have to occupy conquered lands. That is were these Order Police come into play. Police Battalion 101 was used a great deal in Poland. They were subsequently involved in rounding up Polish soldiers cut off behind advancing lines. They also collected military equipment that was abandoned by the retreating Poles, and also providing other services to secure the rear areas. (chap 2 Browning) Another duty that the Order Police were placed with was the collection and deportation of the Jews that occupied Poland. Early in the war they were used in Poland to collect the Jewish people and load then on trains that where headed to the ghettos wer...

On the SAT, How Many People Get a 1400, 1500, or 1600

On the SAT, How Many People Get a 1400, 1500, or 1600 SAT / ACT Prep Online Guides and Tips How many students get a high score on the SAT? How many students get a perfect score? Here we look at the number of students and the percentile of these top ranks. Then we find out whether you should retake the SAT if you get these scores. Note:This guide was created when the SAT used its old 2400 scoring scale. Unfortunately, we don't have the same data for the current version of the SAT (out of 1600 points), but we do have a conversion chart below so you can convert your 1600-scale SAT score to a 2400-scale score and still make use of the information in this article. SAT Score Conversion Chart Below is the conversion chart you can use to convert your current SAT score to the old 2400-scale version of the SAT. For example, if you scored an 1150 on the current version of the SAT, that's equivalent to a 1590 on the old SAT. So 1590 is the score you'd use for reference as you read the rest of the article to get a sense of where you rank in regards to other SAT test takers. New SAT Old SAT New SAT Old SAT New SAT Old SAT 1600 2390 1200 1670 800 1060 1590 2370 1190 1650 790 1040 1580 2350 1180 1640 780 1030 1570 2330 1170 1620 770 1010 1560 2300 1160 1610 760 990 1550 2280 1150 1590 750 980 1540 2260 1140 1570 740 960 1530 2230 1130 1560 730 950 1520 2210 1120 1540 720 930 1510 2190 1110 1530 710 910 1500 2170 1100 1510 700 900 1490 2150 1090 1490 690 880 1480 2130 1080 1480 680 870 1470 2110 1070 1460 670 860 1460 2090 1060 1450 660 850 1450 2080 1050 1430 650 840 1440 2060 1040 1420 640 830 1430 2040 1030 1400 630 820 1420 2020 1020 1390 620 810 1410 2000 1010 1370 610 800 1400 1990 1000 1360 600 790 1390 1970 990 1340 590 780 1380 1950 980 1330 580 770 1370 1930 970 1310 570 760 1360 1920 960 1300 560 750 1350 1900 950 1280 550 740 1340 1880 940 1270 540 730 1330 1870 930 1250 530 730 1320 1850 920 1240 520 720 1310 1840 910 1220 510 710 1300 1820 900 1210 500 700 1290 1810 890 1200 490 690 1280 1790 880 1180 480 680 1270 1780 870 1170 470 670 1260 1760 860 1150 460 660 1250 1750 850 1140 450 650 1240 1730 840 1120 440 640 1230 1710 830 1110 430 630 1220 1700 820 1090 420 620 1210 1680 810 1070 410 610 400 600 Which SAT Data Is the Most Important for You? Before we talk about the exact numbers, it's important to know which data you should care about. Take a score like 2200. According to the College Board, who has comprehensive statistics on all takers of the official SAT, there are 2,574 students who got exactly a 2200 in 2014. However, if you are comparing yourself to the College Board's official numbers, you should be careful about how they construct it.The College Board is only looking at 2014 college-bound seniors - so if you are pretty far removed from this group, it won't represent how you're performing. For example, if you are a sophomore, a 2200 will be much more impressive than the official table of numbers suggests because you've had two less years of school compared to high school seniors. Percentiles vs Absolute Numbers You should also consider whether you should care about absolute numbers or percentiles most. If you care about how you're doing compared to the average test taker, you might care more about percentiles - a 2200 is 98th percentile (or inverted top 2 percentile). This tells you you're within the top 2% of test takers. Picture the median test taker in your mind: aUS student who performs average in class and prepares just a few hours for the SAT. When does comparing against this person help you determine where you are? I suggest that the absolute number of people matters more.After all, Harvard takes in a class of 1200 per year, the top ten colleges probably take in around 20,000, and how you numerically fit into that picture matters more. Cumulative Numbers Back to absolute numbers - 2,574 students got a 2200. But that doesn't mean that if you got a 2200, you're within the top 2,574 students. You have to count all the people who got 2200 or above. In statistics, this is called the cumulative number. This is important because you're not just competing against people who got a 2200 exactly - you're pretty much neck-to-neck with those who got 2210, 2220 and so forth. That's why you want to look at people who got a score or above. This number is most useful to figure out the sort of colleges you're competitive for. For example, if you're in the top 3000 or so, you're competitive for every college, since the top two to three colleges together accept that many per year. Likewise, wherever you place, you can count the slots colleges have above that. The Raw Facts Here is the table showing data for scores from 2200 to 2400, and below is more explanation of what each of the columns show. Score Number of Students Cumulative Number Precise Top Percentile 2400 583 583 0.0348% 2350 630 2969 0.1775% 2300 1371 8812 0.5269% 2250 1914 17225 1.0299% 2200 2574 28834 1.7241% Your Score = The SAT 3-Section Score (out of 2400) Number of Students = Number of students in 2014 who got exactly your score. This number is not cumulative and isn't the best measure of performance. Cumulative Number = This is the total number of students in 2014 who got the same score as you or more. This is the group you're competing with. Precise Percentile = Here we include the precise percentile this score puts you in. The College Board represents percentiles only roughly - they just tell you 99%+ in your score report. We use their exact numbers to re-run the calculation and tell you what exact top fraction you're in. Bonus: Should You Retake the SAT? I've written before that students can easily get 100 points more or less during different SATs without doing anything different, and colleges know that. A change of 100 points is not statistically significant. Does that mean colleges don't care about a 100 point difference - that colleges don't care between a SAT score of 2150 and a 2250, or between a 2250 and 2350? Not at all - because the idea of statistical significance is not the same as expected difference. (This is where my master's degree in statistics can shine!) Statistical significance measures whether someone who got 2350 could get 2250 by likely chance - the answer is absolutely yes! But expected difference measures whether on average, someone who happens to get a 2350 is better than someone who got a 2250 - the answer is also yes. It's not hard to understand intuitively - if you get a 2350 you probably just got a couple of questions wrong, all due to a careless mistake. When you get in the 2250 zone, you're getting up to half a dozen wrong, and that on average reflects a degree of care and mastery that's simply different from a 2350. Our advice then is that especially due to superscoring, even if you're getting 2200, it's worth retaking it up to just above a 2300. What's Next? Not happy with your SAT score?If you want to raise your score,check out our guide on low SAT scoresfor helpful tips. For more strategies, take a look at our guides to getting a perfect SAT score on Reading, Math, Writing and overall. What kinds of study materials do you need to study for the SAT? We break down what the best prep books are (and which books to avoid) in this expert guide. Want to learn more about the SAT but tired of reading blog articles? Then you'll love our free, SAT prep livestreams. Designed and led by PrepScholar SAT experts, these live video events are a great resource for students and parents looking to learn more about the SAT and SAT prep. Click on the button below to register for one of our livestreams today!

Assign3 Assignment Example | Topics and Well Written Essays - 500 words

Assign3 - Assignment Example The proofs were presented through the view of the South Pole Telescope where by the brightest cluster galaxies have been found. They are undergoing a violent internal motion caused by a smashup from other galaxies. Abell 3627 generates an x ray which is blue along with hydrogen light. On the other side, Eso 137-001 galaxy has been seen for 260000 light years. It has a tail which the scientists have failed to understand to date. Clusters of galaxies are a collection of galaxies which are bonded by the gravity that is bounded by hot gases. The tails which were formed from the hot gas formed by the spiral arms of the galaxies. This causes an effect to the galaxy hence evolution changes the formation of the stars. 4. In relevance to the top down structure formation, the scenario first forms the large pancakes then followed by the fragment that forms the lumps which are sized. The scenario is important because of the information concerning the existence of the large sheets with low density. In respect to bottom up structure’s scenario, there occurs a formation of the galaxies which are small and dwarfs first, followed by the formation of the clusters. 5. The world was molten many years ago. It took some years for the earth to cool and pass through the process of conduction and radiation. In respect to laws of thermodynamics, the earth has around 24 to 40 million years. The amount of the salt in the oceans also shows that it must have taken them time for salt evaporation process to occur. Nowadays, oceans have only a small amount of salt. The thickness of existing sedimentary rocks is over three million years old. Marine mollusks have also a number of series of million years on the universe thus the world is old enough to have been completed many years. The decay of the radioactivity processes also passes a number of age measures of the rocks and

What protection is afforded to beneficial co-owners of property in Essay

What protection is afforded to beneficial co-owners of property in situations where the trustees or third parties apply to a court for an order to sell land which is subject to a trust of land - Essay Example The law of co-ownership operates whenever two or more people enjoy the rights of ownership of property at the same time, either freehold or leasehold. The law of co-ownership is to be found in the 1925 legislation (LPA 1925), common law, and TLATA 1996. The law of co-ownership can be broken down into various components, first being the nature of co-ownership and types of co-ownership, Secondly, there is the statutory machinery that regulates the use and enjoyment of co-owned land, thirdly, there are those statutory and common law rules governing the creation of co-ownership, fourthly, there is the impact of co-ownership on third parties, fifthly, there are matters relating to the termination of co-ownership. 1 The concurrent co-ownership of property describes the simultaneous enjoyment of land by two or more persons i.e. enjoyment of the rights of ownership by two or more persons at the same time. Co-ownership since 1 January 1926 will either be by way of a â€Å"joint tenancy† or a â€Å"tenancy in common†.2 In a joint tenancy, each co-owner is treated as being entitled to the whole of that land. There are no distinct â€Å"shares†, and no single co-owner can claim any greater right over any part of the land than other. As far as the rest of the world is concerned, the land is treated as if it is owned by one person only and all the joint tenants share in that one ownership. In practical terms, this means that, when land is subject to a joint tenancy, there is only one formal title to it, and that title is owned jointly by all the joint tenants. Moreover, if the land is registered, there will be but one title registered at HM Land Registry, with each co-owner registered as proprietor of that title in the proprietorship section of the register. If the land is unregistered, there will be but one set of title deeds, specifying the four owners.3 It is pertinent to mention here that prior to 1st January

Landuse analysis of Famagusta Walled City Essay

Landuse analysis of Famagusta Walled City - Essay Example If this trend continues unabated the city will be hollowed out both physically and socially; what is known as the doughnut syndrome. Moreover land is a finite resource and for an island like Cyprus which is an aggregarian island and much of its income depends on what it is able to grow, because this encroachment upon its green field not only eats up arable land but also destroys its biota. Even though several researches have been conducted on this specific area but they have offered palliatives rather than concrete or practical tools for implementation. This paper aims to highlight sustainable ways in which the city should be allowed to expand and develop and to bracket ways in which the theories advanced can be implemented in the city. Implementing this theory would mean redesign and development of the unused spaces according to smart growth theories and principles that oppose everything negative growth stands for. This constitutes tools for compact urban development which include the development of Brownfield sites, infill and mixed use of development and transit oriented

Competitive brand management plan Assignment Example | Topics and Well Written Essays - 2500 words

Competitive brand management plan - Assignment Example The brand activation at this occasion will allow the Co operative healthy brand to build strong relationship with the consumers by helping them to form New Year’s resolution regarding healthy eating and lifestyle. This will also make it easy for the Co operative healthy brand to develop direct associations in the mind of the customers between healthy eating and the Co operative healthy brand. Background Situation: There has been drastic increase in the overall obesity rate all over the globe. In the region of UK around quarter of the adult population are classified as obese (NHS, 2012). This in turn has increased the health concerns among the people. The consumers are shifting towards healthier lifestyle and are giving preference to the healthy and balanced food items as shown in the image below: (Kimmell, 2009) There has been growing shift in the overall consumer purchase behaviour as consumers are giving preference to the foods and drinks which are providing more health bene fits as shown in the image below: (Datamonitor, 2009) This increasing preference for the healthy food items has provided opportunity to the health retailers and supermarkets to provide the customers with different health foods. This in turn has given rise to different own health brands. Co operative food healthy brand is also competing in this category and is trying to increase the market penetration and improve the overall brand image. Brand Positioning: Brand positioning is used in order to present and describe the competitive advantage of a particular brand against other competitors in the industry. This means that brand positioning presents how the brand will compete with the competitors in effective and efficient manner. It is important to keep in consideration different elements and factors in order to come up with effective and long lasting brand positioning (Kapferer, 2008). Goals and Objectives: The goal of the co operative healthy brand is to become the most preferred heal thy brand in the region by increasing overall awareness of its healthy products and encouraging the consumers to shift towards healthy life style and eating. For achieving this goal certain brand objectives have to be fulfilled, which are as follow: The co operative healthy brand should increase the interaction with consumers in order to improve the overall brand awareness and image The co operative healthy brand should provide customers with more value and benefits The co operative food have to provide more promotion and shelf space to its own healthy brands The co operative food healthy brand should improve the overall brand experience of the customers Brand Inventory: It is important for the brand to maintain and manage attractive and easy to access brand inventory in order to increase the brand interaction and awareness. The brand inventory can include brand colour, the logo, tag line, and even the physical location (Keller, 2008). The Co operative food and healthy brand use gre en and other fresh colours

Groups and Teams Paper Essay Example | Topics and Well Written Essays - 750 words - 1

Groups and Teams Paper - Essay Example Harvey Dubin (2005) stresses the need for high performance team: "A high-performing team will produce innovations and results that take the company to the next level." He further adds that this "will reduce costs, increase productivity, shorten time for research and development, and get products and services to market faster." With these advantages, high performance teams are a "must have" for any business organization. The establishment of high performance teams should be commenced by the individual employees' commitment. In starting any specific task, a team can only function efficiently if each of the members vows their total devotion and dedication to the job to be accomplished. Each of the members should not be bound by their past experience but should seek to commit and perform in ways they never have before, opening themselves to new skills and perspectives. According to Harvey (2005): Building a high-performing team is not about people's skills, abilities or knowledge. It's about their commitment. It is not about putting together the right team. It's about putting together the right challenge. It is not about avoiding or overcoming setbacks and corporate resistance. It's about embracing difficulties and leveraging them to galvanize the team in a relentless pursuit of results. A research conducted by the Filine Institute c... Good communication is really a key in achieving process gains. Communication enables the dispensation of relevant information which will aid the whole organization in transferring ideas, evaluating possibilities, and promotes harmonious relationship between group members. Good communication also eliminates probable errors which can be brought about by miscommunications. Cohesion or interdependence is another key in boosting the performance of a team. The realization within the group that they are a part of a cohesive whole whose goals can only be achieved by strong coordination will motivate each member to do best for the group. Cohesion also cultivates each member's sense of belongingness. Meanwhile, Donald J. Bodwell (2002) recognized that high performance teams consistently displays trust, respect, and support for each team member. He argues that "team members need to be coached in the need to trust and support each other" (Bodwell 2002). He emphasizes t he value of support which involves keeping an eye on each team member as well as offering help when needed. In order to become a high performance team, members should constantly show that they are strongly and tightly united in order to achieve a common goal. Nowadays, the new trend in business organizations is diversity hiring. As companies come to recognize the contribution of workplace diversity, it is widely observed that players are closely monitoring the extent of diversity in its human resource. The rationale in favoring a human resource with different origins, backgrounds, interests, and status is fairly simple: diversity will is able to pool together various talents, ideas, skills, and knowledge

Competitive brand management plan Assignment Example | Topics and Well Written Essays - 2500 words

Competitive brand management plan - Assignment Example The brand activation at this occasion will allow the Co operative healthy brand to build strong relationship with the consumers by helping them to form New Year’s resolution regarding healthy eating and lifestyle. This will also make it easy for the Co operative healthy brand to develop direct associations in the mind of the customers between healthy eating and the Co operative healthy brand. Background Situation: There has been drastic increase in the overall obesity rate all over the globe. In the region of UK around quarter of the adult population are classified as obese (NHS, 2012). This in turn has increased the health concerns among the people. The consumers are shifting towards healthier lifestyle and are giving preference to the healthy and balanced food items as shown in the image below: (Kimmell, 2009) There has been growing shift in the overall consumer purchase behaviour as consumers are giving preference to the foods and drinks which are providing more health bene fits as shown in the image below: (Datamonitor, 2009) This increasing preference for the healthy food items has provided opportunity to the health retailers and supermarkets to provide the customers with different health foods. This in turn has given rise to different own health brands. Co operative food healthy brand is also competing in this category and is trying to increase the market penetration and improve the overall brand image. Brand Positioning: Brand positioning is used in order to present and describe the competitive advantage of a particular brand against other competitors in the industry. This means that brand positioning presents how the brand will compete with the competitors in effective and efficient manner. It is important to keep in consideration different elements and factors in order to come up with effective and long lasting brand positioning (Kapferer, 2008). Goals and Objectives: The goal of the co operative healthy brand is to become the most preferred heal thy brand in the region by increasing overall awareness of its healthy products and encouraging the consumers to shift towards healthy life style and eating. For achieving this goal certain brand objectives have to be fulfilled, which are as follow: The co operative healthy brand should increase the interaction with consumers in order to improve the overall brand awareness and image The co operative healthy brand should provide customers with more value and benefits The co operative food have to provide more promotion and shelf space to its own healthy brands The co operative food healthy brand should improve the overall brand experience of the customers Brand Inventory: It is important for the brand to maintain and manage attractive and easy to access brand inventory in order to increase the brand interaction and awareness. The brand inventory can include brand colour, the logo, tag line, and even the physical location (Keller, 2008). The Co operative food and healthy brand use gre en and other fresh colours

Motivational statement for joining Army Medical Corp Reserve Essay

Motivational statement for joining Army Medical Corp Reserve - Essay Example military as a field officer, my immediate objective to joining the Army Medical Corp reserve is to help solders who suffer from both medical and psychological injuries together with their families. This is majorly because I want my country’s defense force to have a positive image of a safe profession that can attract dedicated personnel. By working hard as a medical officer, and through influencing dedication among other members of the reserve, I hope to elimination permanent disabilities among wounded officers, and subsequent psychological instability among their family members. This will not only be a motivational factor to serving army personnel and their families but will also motivate others who currently perceive the military as a risky profession, to join the forces in protecting our country. My interest in adventure, structures, and challenging encounters, opportunities that are available within the reserve’s scope, are also motivators to my desire to join the Army Medical Corp reserve. I am also dedicated to exercise the expected level of discipline that is required within the

Nutrition and The Journey of Life Essay Example for Free

Nutrition and The Journey of Life Essay Caring for and fueling our bodies requires for the mother to take prenatal vitamins in order to meet us to keep a balanced nutrition. Just as our bodies The nutritional needs of the growing fetus. need the right nutritions so does a embryo, futons and baby in order to grow and develop properly. Nutrition and pregnancy The mother must make good nutritional The first eight weeks after fertilization which choices such as eating foods such as the ones is known as the embryonic stage the embryo gets its illustrated above rather then processed foods and nutrition from the lining of the uterus, but after week snacks that will provide little nutrients, these good 9 of development the growing fetus will get its nutritional habits can be practiced after birth and oxygen and nutrients from the placenta. Can be taught to the baby. The fetus is growing everyday which requires a If the nutritional needs of the fetus are not met variety of nutrients such as calcium, copper, folic acid, several health concerns may occur such as iron,vitamins A, B6, C, D and E. The demand for these Complications with fetal development, fetal size nutrients by the fetus will have to be met by having a organs, brain, and may cause a miscarriage and proper and Healthy diet, but it may also be necessary death of the infant and or mother. Post Birth Nutrition Additional Information From conception to birth the process of creating Having the proper knowledge of the nutritional baby requires a lot of energy and nutrient for the mother needs of the body before conception and post and the developing fetus, after the birth of the baby the child birth is very important for the well being newborn will continue to need nutrient in order to grow of the mother, fetus, and baby. The are several and develop. The baby will receive it nutrient from milk resources that people can use to learn more for the first year of its life so it is important to decide about the nutritional needs of the mother and weather the baby will consume breast mil or formula. fetus, listed below are some of these resources. Breast milk VS. Formula 1. Chosemyplate.gov Breast milk is the perfect food for babies it contains all 2. Medline Plus webpage and call center the nutrients that the baby will need to grow and 3. Baby center develop . Unlike formula breast milk contains properties 4. Seek the advice of your doctor that protect against infections such as white blood cells  also breast milk can pass on immune shots that the mother  may receive such as a flu shot. Formula are getting better  through he years to mach the ingredients found in breast   milk such as DHA and ARA. References Choose my plate. (2016). Retrieved from http://www.choosemyplate.gov/pregnancy-breastfeeding/pregnancy-nutritional-needs.html Grosvendr, M., Gmolin, L. (2012). Visualizing Nutrition Everyday Choices (2nd ed.). Retrieved from .

Water Mist Replacement for Halon Extinguishers

Water Mist Replacement for Halon Extinguishers CHAPTER ONE: 1.1: Introduction Choosing the best fire suppression technology is not an easy task. It even involves discussing risks and operations with insurance companies. The most relevant concern of a fire safety engineer is the protection of life which entails the safe evacuation of personnel. The starting point of a suppression system is a risk analysis to reduce the potential occurrence of a fire. This is followed by the control of the damage and the recovery effort or emergency response associated with the means of fire suppression adopted. The quality of installation, efficiency and maintenance of the suppression system adopted cannot be over-emphasised. The phase out of halons, due to environmental concerns, has lead to forceful development of new fire prevention strategies and technologies that are efficient, as well as environmentally friendly technologies. Fire protection halons were phased out of production in developing countries due to the quest to regulate the use of ozone depleting substances(ODS) as reflected in the Montreal Protocol,1987(London Amendment 1990, and Copenhagen amendment1992). Fire suppression agents have two (2) toxicological aspects to them: The toxicity of the agent The toxicity of combustion products of the agent. Several new fire suppression systems have been developed such as inert and halocarbon gaseous systems, water mist systems, gas and aerosol generators. Fire has been extinguished with water since ancient times. Water in the normal form is not a suitable suppression medium of all classes of fire. The efficiency of water in suppression is enhanced by its use of water in form of mists. Survey by Mawhinney and Richardson in 1996 showed that about 50 agencies worldwide are involved in the research and development of water fire mist and suppression systems. Water mist in fire suppression does not behave like true gaseous agents and is affected by fire size, the degree of obstruction, ceiling and the ventilation conditions of the compartment. To effectively suppress a fire, a water mist system must generate and deliver optimum sized droplets with an adequate. 1.2: Objectives and Structure of Dissertation This project aims at studying the water mist as a replacement for halons systems in the extinguishment of fires. This replacement is a direct consequence of the phase out of halons due to environmental issues and the need to find a drop-in replacement or a suitable alternative in areas where high level of fire safety is required and the cost of fatalities is too high. Chapter 2 2.1: Overview of Fire Suppression To suppress fires, the type of fire needs to be identified. The class of the fire to be extinguished also determines the type of extinguisher that can be used. There are six (6) types of fires: Class A FIRES: These involve flammable or combustible solids such as wood, rubber, fabric, paper and some plastics. Class B FIRES: These are fires involving flammable and combustible liquids or liquefiable solids such as oil, alcohol, petrol, paint and liquefiable waxes.[9] Class C FIRES: These are fires involving flammable gases such as natural gas, hydrogen, propane, butane.[9] Class D FIRES: These are fires involving combustible metals, such as sodium and potassium.[9] Class E FIRES: These are fires involving any of the materials found in Class A and B fires, but including electrical appliances, wiring, or other electrically energized objects in the vicinity of the fire, with a resultant electrical shock risk if a conductive agent is used to control the fire.[9] http://www.sqa.org.uk/e-learning/FirstLineO2CD/page_06.htm Class F FIRES: These fires involve cooking fats and oils, especially in industrial kitchens. The temperature of these fats and oil on fire is much greater than that of other flammable liquids. 2.2: Means of Fire Suppression The aim of fire suppression is to provide cooling, control the spread of the fire as well as extinguish the fire. The behaviour of a fire is charcterised by the fire triangle which has fuel, oxygen and heat as its three sides. Combustion process is represented by: Fuel + O2 HEAT H2O + CO2 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn2.1 The combustion process is an exothermic reaction, involving a fuel and oxygen. The ratio of fuel to air must be within the flammability limits of the fuel for combustion to occur. The Lower Flammability Limit (LFL) is the minimum concentration of fuel vapour in air, below which a flame cannot be supported in the presence of an ignition source. The Upper Flammability Level (UFL) is the maximum concentration of fuel vapour in air, above which a flame cannot be supported. Stoichiometric Mixture is the ratio of fuel in oxygen that requires minimal energy to support a flame. A branch of the triangle must be removed for the fire to be extinguished. Fires can either be smoldering or flaming combustion. Smoldering occurs when solids such as wood or plastics burn at or on the surface. It usually involves the release of toxic gases and can be difficult to extinguish. Flaming combustion is a gas phase phenomenon that involves the release of visible and infrared radiation. This type of fire generates much more heat. The extinguishing of a fire involves either chemical or physical mechanisms. Physical mechanism: Involves the removal of one side of the fire triangle. This can be done by either blanketing the fire (causing the fuel and air to be separated) or by removing the heat source using an agent with a high heat capacity/ latent heat of vaporization (this will cool the flame by absorbing the heat). Physical mechanism could be thermal or dilution. Thermal physical effect involves adding non-reactive gas to a fire plume leading to a reduction in the flame temperature. This is achieved by the distribution of the heat generated to a larger heat area. The heat capacity of the introduced agent determines the efficiency of the process. On the other hand, for dilution physical effect, the collision frequency of oxygen molecules with the fuel is lowered when the additional gas is introduced into the fuel-air mixture. This effect is quite minimal and negligible. Chemical mechanism: This is the use of an extinguishing agent or its degradation product to disrupt the chain reaction for sustaining combustion. This entails inhibition by halogen atoms. Most good suppressants apply both the physical and the chemical mechanisms. The type of hazard associated with an area determines the fire protection system that will be put in place. Halons have been used in a wide range of applications. Other alternatives include: Water Sprinkler Systems: This is a very common type of fixed protection that offers safe protection to limit structural damage. The cost of installing water sprinkler systems into existing structures is quite expensive. They are better at protecting structures than its contents [11]. The reliability of water sprinkler system has encouraged its wide use. Accidental discharge is uncommon with water sprinkler systems. Water sprinklers have a much slower response than other systems. They also cause a considerable secondary damage. They cannot be used on live electrical equipment and flammable liquids, but they are used widely in computer and control rooms as well as storage rooms in the USA. Detectors: This involves the use of high sensitive smoke detection. This is not exactly an active fire protection approach but it serves as an initiator to other fire protection systems [2]. Carbon dioxide: Carbon dioxide is widely used in gaseous based fire extinguishing systems. There are two types of carbon dioxide system depending on the manner by which they are stored. These are high pressure and low pressure carbon dioxide systems. It is a clean agent and has a good penetrating ability. This makes it safe for use on live electrical equipment. They are also used in unoccupied spaces such as computer and control rooms. Carbon dioxide causes very minimal direct or secondary damage and allows the installation being put back to immediate use after a fire. It is however toxic and cannot be used in total flooding situations. Carbon dioxide cannot also be used in situations where weight and space are important. High concentrations of carbon dioxide are required for extinguishment and as such they are bulky and heavy. They cannot be used in manned areas because they reduce the oxygen concentration to levels below life support and thus cannot be set in automatic mode. Carbon dioxide systems are generally fast acting and cost effective. Carbon dioxide has also found use in record storage, flammable liquid fires, chemical processing equipment, turbine generators, marine applications, computer rooms and shipboard machinery. Inert Gases: inert gases in use for fire suppression are majorly argon and nitrogen mixtures. These are electrically non-conductive fire suppressants. The mechanism behind their use is the lowering of the oxygen concentration of air to that below the lower flammability point (LFL). They are not liquefied gases and they are bulky because they are stored at high pressure. The concentration of inert gases released in the hazardous area is high because they have densities that are similar to that of air. Their response time is not very fast and so they are not efficient in situations where the rate of fire spread is high. Inert gases do not decompose thermally and thus they form no breakdown products [2]. Inert gases can cause an extreme decrease in the composition of oxygen in the body accompanied by an increase in the concentration of carbon dioxide leading to loss of consciousness or death and as such health and safety issues have to be considered in its use. Inert gases have found wi de acceptance because they pose no environmental problems. They are not ozone depleting substances neither do they contribute to global warming. They are employed in computer and control rooms, record storage, flammable liquid fires and shipboard machinery [2]. Halocarbon Gases: These are hydrofluorocarbons and perfluorocarbons with zero ozone depleting potentials. They are however greenhouse gases and are governed by the Kyoto protocol and hence its release counts towards the national emissions inventory of global warming gases. Halocarbons are electrically non-conductive, are clean agents and are not bulky in terms of space and weight. Foam Systems: Foam systems could be low, medium or high expansion systems. Foam systems are efficient for extinguishing liquid pool fires and large cable fires. In this case, the foam acts as a barrier between the fire and the supply of oxygen. The use of chemical dispersants to clean up after its use has limited the wide use of foam systems. Furthermore the use of smoke detectors for its activation limits its speed of response. They cannot be used to protect any substance that reacts violently with water. Foams systems are often used with water sprinklers. This increases the efficiency of the systems. Foam systems have found use in the extinguishment of flammable liquid fires, engine compartments and shipboard machinery. Dry Powder: Powders have very high response time for extinguishing fires but have no cooling effect. They thus become ineffective as soon as it settles [2]. They are limited in application to extinguishing flammable liquid fires as well as engine spaces. Fine Solid Particulates: This system is used in combination with halocarbon gases and inert gases [2]. They have the advantage of reduced wall and surface losses relative to water mist and particle size is easier to control[2]. They however pose problems to sensitive equipment and cannot be used for explosion suppression applications because they are generated at high temperatures. Fine solid particulates can only be used in unmanned areas because of the problems associated with inhalation of particulate substances. Water Mist: This employs the use of fine water sprays, usually less than 100 microns in diameter. Water mists can be used on flammable liquid fires, as well as electrical equipment. They are not as effective on small or slow burning fires. Water mist installations pose problems in their design and fabrication. Hybrid Systems: Hybrid systems combine one or more of the above fire protection system. A common example of this is the combination of water mist systems and carbon dioxide. There are two methods of applying fire extinguishing agents-Total Flooding and Local Application. Total Flooding: They are operated automatically and manually. It entails applying an extinguishing agent to an enclosed space to achieve a concentration of the extinguisher that is capable of putting out the fire. This method is the most common system of application Local Application: The agent is applied directly onto the fire plume or the affected enclosure. Portable fire extinguishers are the most common forms of this approach. This method is also known as streaming application. There is an increase in the need for the phasing out of halons and this has brought the search for the perfect or drop-in replacement. The department of trade and industry in 1995 listed checklists for the selection of alternatives to halons in critical uses situations as: Fire fighting effectiveness: This involves the speed of fire suppression, the post fire hold time, the ability of the alternative to permeate, the elimination of the risk of reignition, the suitability of the alternative to the fire hazard. Ease of Installation: Ease of maintenance, pipe work, and cost of installation, cost of refill, floor space and weight, system re-instate time, and availability of the extinguisher. Hazards to occupants: Toxicity, noise levels, pressurisation, inhalation, visibility, safety as regards electrical work, thermal decomposition products [2]. Discharge effect on equipment: water damage, clean up, corrosion, thermal shock. Environmental acceptability: Ozone depletion potential, atmospheric lifetime, and global warming potential. Discharge damage: This entails clean up of the agent after use, water damage, thermal shock and corrosion. Esso Australia, while looking for alternatives to halons on their installations considered the following issues [14]: Effectiveness at extinguishing fires Environmental effects (a zero ozone depleting and global warming potential) of the agent before use and after thermal decomposition. Toxicity level and a safety margin between its No Observed Adverse Effects Level (NOAEL value) and the extinguishing concentration required Third party approval from regulatory bodies and safety partners such as International Maritime Organisation (IMO), NFPA, and EPA or Underwriters laboratory Organisations. Level of engineering required to modify an existing halon protected installations. Availability as regards to installation and maintenance at a reasonable cost. 2.2: Health and Safety Issues Considering the health and safety in the UK, there is no specific regulation as regards choice of fire extinguishing systems. Otherwise fire risks and risk from the use of extinguishment can be categorised under risks at work. The Management of Health and Safety at Work Regulations 1992 stipulates all risks at work are to be assessed and prevented where ever it is reasonably practicable, controlled. In cases where fire extinguishing systems contain toxic substances then the Control of Substances Hazardous to Health Regulations 1988 (COSHH regs) will also apply. The basis of the two regulations is the prevention rather than control of the risk. 2.3: Environmental regulations The International Maritime Organisation (IMO) has prohibited the use of new halon systems from 1994, but accepts the use of existing ones. The EU has banned its use onboard vessels by the end of 2003. The following are regulations that are put in place to phase out the use of halons. The Montreal protocol on Substances that Deplete the Ozone layer- the Montreal protocol, signed by 25 countries on the 16th of September, 1987 is an international treaty for the control of the production and use of ozone depleting substances. It involves the restriction and eventual prohibition of the production, distribution and use of Ozone Depleting Substances. A copy of this document is attached in Appendix 1. The EC regulations: This European legislation was put in place to further tighten the restriction on the ban of ozone depleting substances. EC Regulation 3093/94 came into force on the 23rd of December 1994. EC Regulation 3093/94 is directly binding in all EU Member States and does not require any national implementing legislation. The new Regulation EC 2037/2000 came into force on 1 October 2000, replacing the Regulation 3093/94. The enforcement requires the use of bodies such as the HM Customs and Excise concerning import of controlled substances. The Department of the Environment proposes to implement these arrangements through enforcement regulations made under both the Environmental Protection Act 1990 s.140 and the European Communities Act 1972.(EC REGULATION) The new requirements are applicable to the production, distribution, use and recovery, and control of hazardous substances. The regulations also require the recovery of used controlled substances from certain equipment, s uch as fire protection systems, for disposal or recycling, during servicing and maintenance procedures of equipment. A copy of the regulation is attached to Appendix 2. The Victorian Environment Protection Legislation for the Control of Ozone Depleting substances (Victorian Government Gazette No.S57, 1990) this piece of legislation depicts the Australian governments compliance, reliance and advocacy to the implementation of the Montreal protocol on the phasing out of halon use [14]. Environmental Protection agency: Under the Clean Air Amendment, the United States Environmental Protection agency, EPA analysed various substances that could substitute fire extinguishing agents that destroy the ozone layer. These substances also have low global warming potential and low Atmospheric lifetime. The SNAP program (Significant New Alternatives Policy) is used by the EPA to replace the use of halons with environmentally friendly systems in the United States. The Clean Air Act was signed into law in 1990. With this Act, the US banned the production and import of new halons 1211, 1301 and 2402 from the 1st of January 1994 in compliance with the Montreal Protocol. The US government also imposed excise tax on halons through specialized training and proper recycling and disposal. Chapter Three: Halon Systems Halon is the generic name for bromine contained halogenated hydrocarbons. Halons systems were first installed in the late 1960s and early 1970s. In the gaseous form, halons are excellent fire extinguishers. Halons are mostly employed in situations where fire safety standards are high. Halons are identified by a four digit number. The numbering system is assigned by the number of carbon, number of fluorine, chlorine and bromine atoms respectively. Halon 1301, containing carbon, fluorine and bromine is used in total flooding applications while halon 1211, containing carbon, fluorine, chlorine and bromine is used as hand held portable extinguishers. The two common halon types described are effective in extinguishing classes A, B and C fires. These halons are preferred because they exhibited: high efficiency in suffocating combustion, availability in volume at reasonable cost, high storage stability, low electrical conductivity, as well as acceptable toxic properties. 3.1: Characteristics of Halons Halons interfere with the chemical reactions which take place during a fire. The properties of halons allow for its use in most situations and thus most of its applications are linked to particular characteristics. These principal applications include: Clean fire fighting agent: Halons leave no residue after use. This eliminates secondary damages and keeping loss caused by the fire to a minimum [12]. Electrically non-conductive: This property makes it suitable for safe application on fires involving electrical equipment. It will prevent exposure of fire fighters to electric shock. Low toxicity: This property makes halons acceptable and in most cases halon flooding systems are set in automatic mode by default. They can also be used to extinguish fires while people are present in the protected room. Halon flooding systems do not displace so much oxygen which can lead to suffocation[12] Rapid response: Halons are effective for rapid knockdown of flames. This property is mostly essential for class B fires involving liquid and liquefiable solids. Low concentration requirement: This means low quantity or amount of halons are required for extinguishment. It minimizes weight and space allowance [12]. Gaseous state: This allows for good penetration and effective extinguishment in confined spaces. Boiling point: The boiling point of about -4 allows it to be discharged (in the case of hand-held extinguishers) as a liquid for a while before it vaporises. This is a key requirement in some manual fire fighting applications.[12] Low heat of vaporisation: Halons will not condense to form water or ice in halon flooding systems. The most important advantage of halons is in its cost effectiveness. Halon fixed systems are the most cost effective of all extinguishing systems. 3.2: Extinguishing Mechanisms of Halons Halons extinguish fires both chemically and physically. Chemically they interfere with the chemical reactions that take place during the fire. This characterises halons as inhibitors. Radicals released during combustion to keep the fire burning are suppressed chemically by halons. This reaction is anti-catalytic. When halons are heated during combustion, they produce free radicals which compete with those produced by the original combustion process [2]. Halon 1301 produces bromine radicals which react with hydrogen free radicals to produce hydrogen bromide. The hydrogen bromide then reacts with hydroxyl radical to form water and bromide. The bromide released reacts with the combustion fire again and the whole cycle is repeated. The hydrogen and hydroxyl free radicals produced by combustion are greatly reduced in concentration by combining with the halogen free radicals produced by halons [3]. Where RH is the combustible fuel, XBr is a halon agent RH + O2 ENERGY OH + R †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.1 XBr ENERGY Br + X†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.2 RH + Br HBr + R†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.3 HBr + OH H2O + Br†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.4 RH ENERGY R + H†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.5 H + Br HBr†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.6 The combination of bromine and hydroxyl radical is also an ozone destructive reaction: HOBr UV Br + OH†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.7 OH + O3 HO2 + O2..eqn3.8 Br + O3 BrO + O2†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.9 BrO + HO2 HOBr + O2 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.10 3.3: HALONS AND THE OZONE 3.3.1: The ozone layer The earth is enclosed by the atmosphere. This atmosphere is made up of a mixture of numerous gases in varying proportions. The atmosphere is further subdivided into three regions depending on temperature. These regions are: Mesosphere, Stratosphere and Troposphere. The word ozone is from a Greek word, ozein, for to smell. It is an allotropic form of oxygen having three atoms in each molecule. It is a pale blue, highly poisonous gas with a strong odour. [10] In its thickest part in the stratosphere, it is only a trace gas.. Ozone is highest in concentration, about 97%, in the stratosphere (15-60 kilometers above the Earths surface) where it absorbs the ultraviolet radiation from the sun. Ozone is also highly concentrated at the Earths surface in and around cities. The buildup of ozone on the earths surface in and around cities is a result of industrial activities and is toxic to organisms living at the Earths surface. Table 3.1 shows the percentage volume composition of the constituents of atmospheric air *variable gases http://www.physicalgeography.net/fundamentals/7a.html Ozone is very reactive and a stronger oxidising agent than oxygen. It is used in purifying water, sterilising air, and bleaching certain foods. Ozone is formed when an electric spark is passed through oxygen. Ozone is prepared commercially by passing cold, dry oxygen through a silent electrical discharge [7]. Ozone formed in the atmosphere is from nitrogen oxides and organic gases emitted by automobiles and industrial sources [7]. This is achieved by short wavelength ultraviolet. This is actually a health hazard, and it may cause crop damage in some regions. Ultraviolet wavelengths less than 200 nanometer reacts with oxygen molecules to make ozone. O2 UV O + O†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.11 O + O2 O3 + Heat†¦Ã¢â‚¬ ¦.eqn3.12 The heat released here is absorbed by the atmosphere and results in a rise in temperature of the atmosphere. The structure of ozone has 3 oxygen atoms, but steric hindrance prevents it from forming a triangular structure, with each O atom forming the expected 2 bonds. Instead each atom of oxygen forms only 1 bond, with the remaining negative charge being spread throughout the molecule.[7] Ozone is very unstable. It is decomposed either by collision with monoatomic oxygen or by ultraviolet radiation on it. The decomposition causes ozone to form oxygen molecules. Heat is also released to the atmosphere by this reaction O + O3 O2 + O2†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.13 O3 UV O2 + O + Heat†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.14 Ozone is decomposed in the stratosphere to prevent highly energetic ultraviolet radiation from reaching the surface of the earth. 3.3.2: Halons and ozone depletion The ozone layer is mainly depleted by compounds containing chlorine and bromine. Halogens are a chemical family containing fluorine, chlorine, bromine and iodine; any carbon compound containing them is known as a halocarbon. While all halogens have the ability to catalyze ozone breakdown, they have an unequal impact on the ozone layer. The quantity of halons released into the atmosphere is small relative to the number of gases present in the atmosphere. Yet they are more active in destroying the ozone or disrupting the ozone balance for two reasons: Ozone is in a constant state of imbalance, as it is destroyed and produced by natural processes. This process is controlled by solar input that does not undergo significant fluctuations. The stability of halons makes it transportable from the troposphere to the stratosphere where halogens are made active and broken down very fast, destroying ozone in the stratosphere. . The impact is described as depletion potential of the halocarbon. The OZONE DEPLETING POTENTIAL (ODP) is a simple measure of its ability to destroy stratospheric ozone. The ODP of compounds are calculated with reference to the ODP of CFC-11, which is defined to be 1. Thus ODP is a relative measure. A compound withan ODP of 0.2 is, roughly speaking, one-fifth as bad as CFC-11. The ODP of a compound x is expressed mathematically as the ratio of the total amount of ozone destroyed by a fixed amount of compound x to the amount of ozone destroyed by the same mass of CFC-11[8]: Global loss of Ozone due to x ODP(x) == †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.15[8] Global loss of ozone due to CFC-11. The above expression depicts that the ODP of CFC-11 is 1.0 by definition. The uncertainties experienced in evaluating the global loss of ozone due to a compound are eliminated here since the mathematical expression is a ratio. Evaluating the ODP of a compound is affected by the following: The quantity of chlorine or bromine atoms in a molecule. The nature of the halogen, as bromine is a more ozone- destructive catalyst than chlorine. Atmospheric lifetime of the substance: The atmospheric lifetime of the halon is the time it takes for the global amount of the gas to decay to 36.8% of its original concentration after initial emission. Compounds with low atmospheric lifetimes have lower ODP because it is destroyed in the troposphere. Molecular mass of the substance: This is because ODP is evaluated by comparing equal masses and not number of moles. Table3.2 gives time-dependent and steady-state ODPs for some halocarbon in wide use. Compound Formula Ozone Depletion Potential 10yr 30yr 100yr Steady State CFC-113 CF2ClFCl2 0.56 0.62 0.78 1.10 Carbon tetrachloride CCl4 1.25 1.22 1.14 1.08 Methyl Chloroform CH3CCl3 0.75 0.32 0.15 0.12 HCFC-22 CHF2Cl 0.17 0.12 0.07 0.05 Halon-1301 CF3Br 10.4 Water Mist Replacement for Halon Extinguishers Water Mist Replacement for Halon Extinguishers CHAPTER ONE: 1.1: Introduction Choosing the best fire suppression technology is not an easy task. It even involves discussing risks and operations with insurance companies. The most relevant concern of a fire safety engineer is the protection of life which entails the safe evacuation of personnel. The starting point of a suppression system is a risk analysis to reduce the potential occurrence of a fire. This is followed by the control of the damage and the recovery effort or emergency response associated with the means of fire suppression adopted. The quality of installation, efficiency and maintenance of the suppression system adopted cannot be over-emphasised. The phase out of halons, due to environmental concerns, has lead to forceful development of new fire prevention strategies and technologies that are efficient, as well as environmentally friendly technologies. Fire protection halons were phased out of production in developing countries due to the quest to regulate the use of ozone depleting substances(ODS) as reflected in the Montreal Protocol,1987(London Amendment 1990, and Copenhagen amendment1992). Fire suppression agents have two (2) toxicological aspects to them: The toxicity of the agent The toxicity of combustion products of the agent. Several new fire suppression systems have been developed such as inert and halocarbon gaseous systems, water mist systems, gas and aerosol generators. Fire has been extinguished with water since ancient times. Water in the normal form is not a suitable suppression medium of all classes of fire. The efficiency of water in suppression is enhanced by its use of water in form of mists. Survey by Mawhinney and Richardson in 1996 showed that about 50 agencies worldwide are involved in the research and development of water fire mist and suppression systems. Water mist in fire suppression does not behave like true gaseous agents and is affected by fire size, the degree of obstruction, ceiling and the ventilation conditions of the compartment. To effectively suppress a fire, a water mist system must generate and deliver optimum sized droplets with an adequate. 1.2: Objectives and Structure of Dissertation This project aims at studying the water mist as a replacement for halons systems in the extinguishment of fires. This replacement is a direct consequence of the phase out of halons due to environmental issues and the need to find a drop-in replacement or a suitable alternative in areas where high level of fire safety is required and the cost of fatalities is too high. Chapter 2 2.1: Overview of Fire Suppression To suppress fires, the type of fire needs to be identified. The class of the fire to be extinguished also determines the type of extinguisher that can be used. There are six (6) types of fires: Class A FIRES: These involve flammable or combustible solids such as wood, rubber, fabric, paper and some plastics. Class B FIRES: These are fires involving flammable and combustible liquids or liquefiable solids such as oil, alcohol, petrol, paint and liquefiable waxes.[9] Class C FIRES: These are fires involving flammable gases such as natural gas, hydrogen, propane, butane.[9] Class D FIRES: These are fires involving combustible metals, such as sodium and potassium.[9] Class E FIRES: These are fires involving any of the materials found in Class A and B fires, but including electrical appliances, wiring, or other electrically energized objects in the vicinity of the fire, with a resultant electrical shock risk if a conductive agent is used to control the fire.[9] http://www.sqa.org.uk/e-learning/FirstLineO2CD/page_06.htm Class F FIRES: These fires involve cooking fats and oils, especially in industrial kitchens. The temperature of these fats and oil on fire is much greater than that of other flammable liquids. 2.2: Means of Fire Suppression The aim of fire suppression is to provide cooling, control the spread of the fire as well as extinguish the fire. The behaviour of a fire is charcterised by the fire triangle which has fuel, oxygen and heat as its three sides. Combustion process is represented by: Fuel + O2 HEAT H2O + CO2 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn2.1 The combustion process is an exothermic reaction, involving a fuel and oxygen. The ratio of fuel to air must be within the flammability limits of the fuel for combustion to occur. The Lower Flammability Limit (LFL) is the minimum concentration of fuel vapour in air, below which a flame cannot be supported in the presence of an ignition source. The Upper Flammability Level (UFL) is the maximum concentration of fuel vapour in air, above which a flame cannot be supported. Stoichiometric Mixture is the ratio of fuel in oxygen that requires minimal energy to support a flame. A branch of the triangle must be removed for the fire to be extinguished. Fires can either be smoldering or flaming combustion. Smoldering occurs when solids such as wood or plastics burn at or on the surface. It usually involves the release of toxic gases and can be difficult to extinguish. Flaming combustion is a gas phase phenomenon that involves the release of visible and infrared radiation. This type of fire generates much more heat. The extinguishing of a fire involves either chemical or physical mechanisms. Physical mechanism: Involves the removal of one side of the fire triangle. This can be done by either blanketing the fire (causing the fuel and air to be separated) or by removing the heat source using an agent with a high heat capacity/ latent heat of vaporization (this will cool the flame by absorbing the heat). Physical mechanism could be thermal or dilution. Thermal physical effect involves adding non-reactive gas to a fire plume leading to a reduction in the flame temperature. This is achieved by the distribution of the heat generated to a larger heat area. The heat capacity of the introduced agent determines the efficiency of the process. On the other hand, for dilution physical effect, the collision frequency of oxygen molecules with the fuel is lowered when the additional gas is introduced into the fuel-air mixture. This effect is quite minimal and negligible. Chemical mechanism: This is the use of an extinguishing agent or its degradation product to disrupt the chain reaction for sustaining combustion. This entails inhibition by halogen atoms. Most good suppressants apply both the physical and the chemical mechanisms. The type of hazard associated with an area determines the fire protection system that will be put in place. Halons have been used in a wide range of applications. Other alternatives include: Water Sprinkler Systems: This is a very common type of fixed protection that offers safe protection to limit structural damage. The cost of installing water sprinkler systems into existing structures is quite expensive. They are better at protecting structures than its contents [11]. The reliability of water sprinkler system has encouraged its wide use. Accidental discharge is uncommon with water sprinkler systems. Water sprinklers have a much slower response than other systems. They also cause a considerable secondary damage. They cannot be used on live electrical equipment and flammable liquids, but they are used widely in computer and control rooms as well as storage rooms in the USA. Detectors: This involves the use of high sensitive smoke detection. This is not exactly an active fire protection approach but it serves as an initiator to other fire protection systems [2]. Carbon dioxide: Carbon dioxide is widely used in gaseous based fire extinguishing systems. There are two types of carbon dioxide system depending on the manner by which they are stored. These are high pressure and low pressure carbon dioxide systems. It is a clean agent and has a good penetrating ability. This makes it safe for use on live electrical equipment. They are also used in unoccupied spaces such as computer and control rooms. Carbon dioxide causes very minimal direct or secondary damage and allows the installation being put back to immediate use after a fire. It is however toxic and cannot be used in total flooding situations. Carbon dioxide cannot also be used in situations where weight and space are important. High concentrations of carbon dioxide are required for extinguishment and as such they are bulky and heavy. They cannot be used in manned areas because they reduce the oxygen concentration to levels below life support and thus cannot be set in automatic mode. Carbon dioxide systems are generally fast acting and cost effective. Carbon dioxide has also found use in record storage, flammable liquid fires, chemical processing equipment, turbine generators, marine applications, computer rooms and shipboard machinery. Inert Gases: inert gases in use for fire suppression are majorly argon and nitrogen mixtures. These are electrically non-conductive fire suppressants. The mechanism behind their use is the lowering of the oxygen concentration of air to that below the lower flammability point (LFL). They are not liquefied gases and they are bulky because they are stored at high pressure. The concentration of inert gases released in the hazardous area is high because they have densities that are similar to that of air. Their response time is not very fast and so they are not efficient in situations where the rate of fire spread is high. Inert gases do not decompose thermally and thus they form no breakdown products [2]. Inert gases can cause an extreme decrease in the composition of oxygen in the body accompanied by an increase in the concentration of carbon dioxide leading to loss of consciousness or death and as such health and safety issues have to be considered in its use. Inert gases have found wi de acceptance because they pose no environmental problems. They are not ozone depleting substances neither do they contribute to global warming. They are employed in computer and control rooms, record storage, flammable liquid fires and shipboard machinery [2]. Halocarbon Gases: These are hydrofluorocarbons and perfluorocarbons with zero ozone depleting potentials. They are however greenhouse gases and are governed by the Kyoto protocol and hence its release counts towards the national emissions inventory of global warming gases. Halocarbons are electrically non-conductive, are clean agents and are not bulky in terms of space and weight. Foam Systems: Foam systems could be low, medium or high expansion systems. Foam systems are efficient for extinguishing liquid pool fires and large cable fires. In this case, the foam acts as a barrier between the fire and the supply of oxygen. The use of chemical dispersants to clean up after its use has limited the wide use of foam systems. Furthermore the use of smoke detectors for its activation limits its speed of response. They cannot be used to protect any substance that reacts violently with water. Foams systems are often used with water sprinklers. This increases the efficiency of the systems. Foam systems have found use in the extinguishment of flammable liquid fires, engine compartments and shipboard machinery. Dry Powder: Powders have very high response time for extinguishing fires but have no cooling effect. They thus become ineffective as soon as it settles [2]. They are limited in application to extinguishing flammable liquid fires as well as engine spaces. Fine Solid Particulates: This system is used in combination with halocarbon gases and inert gases [2]. They have the advantage of reduced wall and surface losses relative to water mist and particle size is easier to control[2]. They however pose problems to sensitive equipment and cannot be used for explosion suppression applications because they are generated at high temperatures. Fine solid particulates can only be used in unmanned areas because of the problems associated with inhalation of particulate substances. Water Mist: This employs the use of fine water sprays, usually less than 100 microns in diameter. Water mists can be used on flammable liquid fires, as well as electrical equipment. They are not as effective on small or slow burning fires. Water mist installations pose problems in their design and fabrication. Hybrid Systems: Hybrid systems combine one or more of the above fire protection system. A common example of this is the combination of water mist systems and carbon dioxide. There are two methods of applying fire extinguishing agents-Total Flooding and Local Application. Total Flooding: They are operated automatically and manually. It entails applying an extinguishing agent to an enclosed space to achieve a concentration of the extinguisher that is capable of putting out the fire. This method is the most common system of application Local Application: The agent is applied directly onto the fire plume or the affected enclosure. Portable fire extinguishers are the most common forms of this approach. This method is also known as streaming application. There is an increase in the need for the phasing out of halons and this has brought the search for the perfect or drop-in replacement. The department of trade and industry in 1995 listed checklists for the selection of alternatives to halons in critical uses situations as: Fire fighting effectiveness: This involves the speed of fire suppression, the post fire hold time, the ability of the alternative to permeate, the elimination of the risk of reignition, the suitability of the alternative to the fire hazard. Ease of Installation: Ease of maintenance, pipe work, and cost of installation, cost of refill, floor space and weight, system re-instate time, and availability of the extinguisher. Hazards to occupants: Toxicity, noise levels, pressurisation, inhalation, visibility, safety as regards electrical work, thermal decomposition products [2]. Discharge effect on equipment: water damage, clean up, corrosion, thermal shock. Environmental acceptability: Ozone depletion potential, atmospheric lifetime, and global warming potential. Discharge damage: This entails clean up of the agent after use, water damage, thermal shock and corrosion. Esso Australia, while looking for alternatives to halons on their installations considered the following issues [14]: Effectiveness at extinguishing fires Environmental effects (a zero ozone depleting and global warming potential) of the agent before use and after thermal decomposition. Toxicity level and a safety margin between its No Observed Adverse Effects Level (NOAEL value) and the extinguishing concentration required Third party approval from regulatory bodies and safety partners such as International Maritime Organisation (IMO), NFPA, and EPA or Underwriters laboratory Organisations. Level of engineering required to modify an existing halon protected installations. Availability as regards to installation and maintenance at a reasonable cost. 2.2: Health and Safety Issues Considering the health and safety in the UK, there is no specific regulation as regards choice of fire extinguishing systems. Otherwise fire risks and risk from the use of extinguishment can be categorised under risks at work. The Management of Health and Safety at Work Regulations 1992 stipulates all risks at work are to be assessed and prevented where ever it is reasonably practicable, controlled. In cases where fire extinguishing systems contain toxic substances then the Control of Substances Hazardous to Health Regulations 1988 (COSHH regs) will also apply. The basis of the two regulations is the prevention rather than control of the risk. 2.3: Environmental regulations The International Maritime Organisation (IMO) has prohibited the use of new halon systems from 1994, but accepts the use of existing ones. The EU has banned its use onboard vessels by the end of 2003. The following are regulations that are put in place to phase out the use of halons. The Montreal protocol on Substances that Deplete the Ozone layer- the Montreal protocol, signed by 25 countries on the 16th of September, 1987 is an international treaty for the control of the production and use of ozone depleting substances. It involves the restriction and eventual prohibition of the production, distribution and use of Ozone Depleting Substances. A copy of this document is attached in Appendix 1. The EC regulations: This European legislation was put in place to further tighten the restriction on the ban of ozone depleting substances. EC Regulation 3093/94 came into force on the 23rd of December 1994. EC Regulation 3093/94 is directly binding in all EU Member States and does not require any national implementing legislation. The new Regulation EC 2037/2000 came into force on 1 October 2000, replacing the Regulation 3093/94. The enforcement requires the use of bodies such as the HM Customs and Excise concerning import of controlled substances. The Department of the Environment proposes to implement these arrangements through enforcement regulations made under both the Environmental Protection Act 1990 s.140 and the European Communities Act 1972.(EC REGULATION) The new requirements are applicable to the production, distribution, use and recovery, and control of hazardous substances. The regulations also require the recovery of used controlled substances from certain equipment, s uch as fire protection systems, for disposal or recycling, during servicing and maintenance procedures of equipment. A copy of the regulation is attached to Appendix 2. The Victorian Environment Protection Legislation for the Control of Ozone Depleting substances (Victorian Government Gazette No.S57, 1990) this piece of legislation depicts the Australian governments compliance, reliance and advocacy to the implementation of the Montreal protocol on the phasing out of halon use [14]. Environmental Protection agency: Under the Clean Air Amendment, the United States Environmental Protection agency, EPA analysed various substances that could substitute fire extinguishing agents that destroy the ozone layer. These substances also have low global warming potential and low Atmospheric lifetime. The SNAP program (Significant New Alternatives Policy) is used by the EPA to replace the use of halons with environmentally friendly systems in the United States. The Clean Air Act was signed into law in 1990. With this Act, the US banned the production and import of new halons 1211, 1301 and 2402 from the 1st of January 1994 in compliance with the Montreal Protocol. The US government also imposed excise tax on halons through specialized training and proper recycling and disposal. Chapter Three: Halon Systems Halon is the generic name for bromine contained halogenated hydrocarbons. Halons systems were first installed in the late 1960s and early 1970s. In the gaseous form, halons are excellent fire extinguishers. Halons are mostly employed in situations where fire safety standards are high. Halons are identified by a four digit number. The numbering system is assigned by the number of carbon, number of fluorine, chlorine and bromine atoms respectively. Halon 1301, containing carbon, fluorine and bromine is used in total flooding applications while halon 1211, containing carbon, fluorine, chlorine and bromine is used as hand held portable extinguishers. The two common halon types described are effective in extinguishing classes A, B and C fires. These halons are preferred because they exhibited: high efficiency in suffocating combustion, availability in volume at reasonable cost, high storage stability, low electrical conductivity, as well as acceptable toxic properties. 3.1: Characteristics of Halons Halons interfere with the chemical reactions which take place during a fire. The properties of halons allow for its use in most situations and thus most of its applications are linked to particular characteristics. These principal applications include: Clean fire fighting agent: Halons leave no residue after use. This eliminates secondary damages and keeping loss caused by the fire to a minimum [12]. Electrically non-conductive: This property makes it suitable for safe application on fires involving electrical equipment. It will prevent exposure of fire fighters to electric shock. Low toxicity: This property makes halons acceptable and in most cases halon flooding systems are set in automatic mode by default. They can also be used to extinguish fires while people are present in the protected room. Halon flooding systems do not displace so much oxygen which can lead to suffocation[12] Rapid response: Halons are effective for rapid knockdown of flames. This property is mostly essential for class B fires involving liquid and liquefiable solids. Low concentration requirement: This means low quantity or amount of halons are required for extinguishment. It minimizes weight and space allowance [12]. Gaseous state: This allows for good penetration and effective extinguishment in confined spaces. Boiling point: The boiling point of about -4 allows it to be discharged (in the case of hand-held extinguishers) as a liquid for a while before it vaporises. This is a key requirement in some manual fire fighting applications.[12] Low heat of vaporisation: Halons will not condense to form water or ice in halon flooding systems. The most important advantage of halons is in its cost effectiveness. Halon fixed systems are the most cost effective of all extinguishing systems. 3.2: Extinguishing Mechanisms of Halons Halons extinguish fires both chemically and physically. Chemically they interfere with the chemical reactions that take place during the fire. This characterises halons as inhibitors. Radicals released during combustion to keep the fire burning are suppressed chemically by halons. This reaction is anti-catalytic. When halons are heated during combustion, they produce free radicals which compete with those produced by the original combustion process [2]. Halon 1301 produces bromine radicals which react with hydrogen free radicals to produce hydrogen bromide. The hydrogen bromide then reacts with hydroxyl radical to form water and bromide. The bromide released reacts with the combustion fire again and the whole cycle is repeated. The hydrogen and hydroxyl free radicals produced by combustion are greatly reduced in concentration by combining with the halogen free radicals produced by halons [3]. Where RH is the combustible fuel, XBr is a halon agent RH + O2 ENERGY OH + R †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.1 XBr ENERGY Br + X†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.2 RH + Br HBr + R†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.3 HBr + OH H2O + Br†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.4 RH ENERGY R + H†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.5 H + Br HBr†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.6 The combination of bromine and hydroxyl radical is also an ozone destructive reaction: HOBr UV Br + OH†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.7 OH + O3 HO2 + O2..eqn3.8 Br + O3 BrO + O2†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.9 BrO + HO2 HOBr + O2 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.10 3.3: HALONS AND THE OZONE 3.3.1: The ozone layer The earth is enclosed by the atmosphere. This atmosphere is made up of a mixture of numerous gases in varying proportions. The atmosphere is further subdivided into three regions depending on temperature. These regions are: Mesosphere, Stratosphere and Troposphere. The word ozone is from a Greek word, ozein, for to smell. It is an allotropic form of oxygen having three atoms in each molecule. It is a pale blue, highly poisonous gas with a strong odour. [10] In its thickest part in the stratosphere, it is only a trace gas.. Ozone is highest in concentration, about 97%, in the stratosphere (15-60 kilometers above the Earths surface) where it absorbs the ultraviolet radiation from the sun. Ozone is also highly concentrated at the Earths surface in and around cities. The buildup of ozone on the earths surface in and around cities is a result of industrial activities and is toxic to organisms living at the Earths surface. Table 3.1 shows the percentage volume composition of the constituents of atmospheric air *variable gases http://www.physicalgeography.net/fundamentals/7a.html Ozone is very reactive and a stronger oxidising agent than oxygen. It is used in purifying water, sterilising air, and bleaching certain foods. Ozone is formed when an electric spark is passed through oxygen. Ozone is prepared commercially by passing cold, dry oxygen through a silent electrical discharge [7]. Ozone formed in the atmosphere is from nitrogen oxides and organic gases emitted by automobiles and industrial sources [7]. This is achieved by short wavelength ultraviolet. This is actually a health hazard, and it may cause crop damage in some regions. Ultraviolet wavelengths less than 200 nanometer reacts with oxygen molecules to make ozone. O2 UV O + O†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.11 O + O2 O3 + Heat†¦Ã¢â‚¬ ¦.eqn3.12 The heat released here is absorbed by the atmosphere and results in a rise in temperature of the atmosphere. The structure of ozone has 3 oxygen atoms, but steric hindrance prevents it from forming a triangular structure, with each O atom forming the expected 2 bonds. Instead each atom of oxygen forms only 1 bond, with the remaining negative charge being spread throughout the molecule.[7] Ozone is very unstable. It is decomposed either by collision with monoatomic oxygen or by ultraviolet radiation on it. The decomposition causes ozone to form oxygen molecules. Heat is also released to the atmosphere by this reaction O + O3 O2 + O2†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.13 O3 UV O2 + O + Heat†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.14 Ozone is decomposed in the stratosphere to prevent highly energetic ultraviolet radiation from reaching the surface of the earth. 3.3.2: Halons and ozone depletion The ozone layer is mainly depleted by compounds containing chlorine and bromine. Halogens are a chemical family containing fluorine, chlorine, bromine and iodine; any carbon compound containing them is known as a halocarbon. While all halogens have the ability to catalyze ozone breakdown, they have an unequal impact on the ozone layer. The quantity of halons released into the atmosphere is small relative to the number of gases present in the atmosphere. Yet they are more active in destroying the ozone or disrupting the ozone balance for two reasons: Ozone is in a constant state of imbalance, as it is destroyed and produced by natural processes. This process is controlled by solar input that does not undergo significant fluctuations. The stability of halons makes it transportable from the troposphere to the stratosphere where halogens are made active and broken down very fast, destroying ozone in the stratosphere. . The impact is described as depletion potential of the halocarbon. The OZONE DEPLETING POTENTIAL (ODP) is a simple measure of its ability to destroy stratospheric ozone. The ODP of compounds are calculated with reference to the ODP of CFC-11, which is defined to be 1. Thus ODP is a relative measure. A compound withan ODP of 0.2 is, roughly speaking, one-fifth as bad as CFC-11. The ODP of a compound x is expressed mathematically as the ratio of the total amount of ozone destroyed by a fixed amount of compound x to the amount of ozone destroyed by the same mass of CFC-11[8]: Global loss of Ozone due to x ODP(x) == †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.15[8] Global loss of ozone due to CFC-11. The above expression depicts that the ODP of CFC-11 is 1.0 by definition. The uncertainties experienced in evaluating the global loss of ozone due to a compound are eliminated here since the mathematical expression is a ratio. Evaluating the ODP of a compound is affected by the following: The quantity of chlorine or bromine atoms in a molecule. The nature of the halogen, as bromine is a more ozone- destructive catalyst than chlorine. Atmospheric lifetime of the substance: The atmospheric lifetime of the halon is the time it takes for the global amount of the gas to decay to 36.8% of its original concentration after initial emission. Compounds with low atmospheric lifetimes have lower ODP because it is destroyed in the troposphere. Molecular mass of the substance: This is because ODP is evaluated by comparing equal masses and not number of moles. Table3.2 gives time-dependent and steady-state ODPs for some halocarbon in wide use. Compound Formula Ozone Depletion Potential 10yr 30yr 100yr Steady State CFC-113 CF2ClFCl2 0.56 0.62 0.78 1.10 Carbon tetrachloride CCl4 1.25 1.22 1.14 1.08 Methyl Chloroform CH3CCl3 0.75 0.32 0.15 0.12 HCFC-22 CHF2Cl 0.17 0.12 0.07 0.05 Halon-1301 CF3Br 10.4