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

O.B Case Studies

|VALUES, ATTITUDES, AND JOB SATISFACTION | LEARNING OBJECTIVES After studying this chapter, students should be able to: 1. Contrast terminal and instrumental values 2. List the dominant values in today’s workforce 3. Identify the five value dimensions of national culture 4. Contrast the three components of an attitude 5. Summarize the relationship between attitudes and behavior 6. Identify the role that consistency plays in attitudes 7. State the relationship between job satisfaction and behavior 8.Identify four employee responses to dissatisfaction CHAPTER OVERVIEW Why is it important to know an individual’s values? Although they do not have a direct impact on behavior, values strongly influence a person’s attitudes. Knowledge of an individual’s value system can provide insight into his/her attitudes. Given that people’s values differ, managers can use the Rokeach Value Survey to assess potential employees and determine if their values align with the dominant values of the organization. An employee’s performance and satisfaction are likely to be higher if his/her values fit well with the organization.For instance, the person who places high importance on imagination, independence, and freedom is likely to be poorly matched with an organization that seeks conformity from its employees. Managers are more likely to appreciate, evaluate positively, and allocate rewards to employees who â€Å"fit in,† and employees are more likely to be satisfied if they perceive that they do fit. This argues for management to strive during the selection of new employees to find job candidates who not only have the ability, experience, and motivation to perform, but also a value system that is ompatible with the organization’s. Managers should be interested in their employees’ attitudes because attitudes give warnings of potential problems and because they influence behavior. Satisfied and committed employees, for inst ance, have lower rates of turnover and absenteeism. Given that managers want to keep resignations and absences down—especially among their more productive employees—they will want to do those things that will generate positive job attitudes.Managers should also be aware that employees will try to reduce cognitive dissonance. More importantly, dissonance can be managed. If employees are required to engage in activities that appear inconsistent to them or are at odds with their attitudes, the pressures to reduce the resulting dissonance are lessened when the employee perceives that the dissonance is externally imposed and is beyond his/her control or if the rewards are significant enough to offset the dissonance. WEB EXERCISESAt the end of each chapter of this instructor’s manual, you will find suggested exercises and ideas for researching the WWW on OB topics. The exercises â€Å"Exploring OB Topics on the Web† are set up so that you can simply photocopy t he pages, distribute them to your class, make assignments accordingly. You may want to assign the exercises as an out-of-class activity or as lab activities with your class. Within the lecture notes the graphic will note that there is a WWW activity to support this material.The chapter opens introducing Marge Savage, a Microsoft marketing analyst who is gathering information about the â€Å"Nexters† generation—people born after 1977. They are the first group of people to never know a world without computers and the Internet. She found that this group values integrity, teamwork, moral support, responsibility, and freedom to pursue their dreams. They want to work for a company that supports their needs, and where they can have significant influence in shaping society.They see technology and the Internet as a major force for changing the world—good news for Microsoft. CHAPTER OUTLINE |Values |Notes: | |Values represent basic convictions that â€Å"a specific mode of conduct or end-state of existence is personally or | | |socially preferable to an opposite or converse mode of conduct or end-state of existence. | | | | | |There is a judgmental element of what is right, good, or desirable. | | | | | |Values have both content and intensity attributes. | | | | |The content attribute says that a mode of conduct or end-state of existence is important. | | |The intensity attribute specifies how important it is. | | |Ranking an individual’s values in terms of their intensity equals that person’s value system. | | | | |Values are not generally fluid and flexible. They tend to be relatively stable and enduring. | | | | | |A significant portion of the values we hold is established in our early years—from parents, teachers, friends, | | |and others. | |The process of questioning our values, of course, may result in a change, but more often, our questioning acts | | |to reinforce the values we hold. | | |A. Importance of Values | | |1.Values lay the foundation for the understanding of attitudes and motivation because they influence our | | |perceptions. | | | | | |2. Individuals enter organizations with notions of what is right and wrong with which they interpret behaviors| | |or outcomes—at times this can cloud objectivity and rationality. | | | | |3. Values generally influence attitudes and behavior. | | |B. Types of Values | | |1.Rokeach Value Survey (Exhibit 3-1) | | | | | |It consists of two sets of values, with each set containing 18 individual value items. | | |One set—terminal values—refers to desirable end-states of existence, the goals that a person would like to | | |achieve during his/her lifetime. | |The other—instrumental values—refers to preferable modes of behavior, or means of achieving the terminal values. | | | | | | | | |2. Several studies confirm that the RVS values vary among groups. | | | | |People in the same occupations or categories t end to hold similar values. | | |Contemporary Work Cohorts | | |1.The unique value of different cohorts is that the U. S. workforce can be segmented by the era they entered | | |the workforce. (Exhibit 3-3) | | |Contemporary Work Cohorts (cont. ) |Notes: | |2.Veterans—Workers who entered the workforce from the early 1940s through the early 1960s | | |Influenced by the Great Depression and World War II | | |Believe in hard work | | |Tend to be loyal to their employer | | |Terminal values: Comfortable life and family security | | | | | |3. Boomers—Employees who entered the workforce during the 1960s through the mid-1980s | | | | | |Influenced heavily by John F.Kennedy, the civil rights and feminist movements, the Beatles, the Vietnam War, | | |and baby-boom competition | | |Distrust authority, but have a high emphasis on achievement and material success | | |Organizations who employ them are vehicles for their careers | | |Terminal values: sense of accomplishment and social recognition | | | | | |4.Xers—began to enter the workforce from the mid-1980s | | | | | |Shaped by globalization, two-career parents, MTV, AIDS, and computers | | |Value flexibility, life options, and achievement of job satisfaction | | |Family and relationships are important and enjoy team-oriented work | | |Money is important, but will trade off for increased leisure time | | |Less willing to make personal sacrifices for employers than previous generations | | |Terminal values: true friendship, happiness, and pleasure | | | | | |5. Nexters—most recent entrants into the workforce. | | | | |Grew up in prosperous times, have high expectation, believe in themselves, and confident in their ability to | | |succeed | | |Never-ending search for ideal job; see nothing wrong with job-hopping | | |Seek financial success | | |Enjoy team work, but are highly self-reliant | | |Terminal values: freedom and comfortable life | | | | | |Individuals’ values dif fer, but tend to reflect the societal values of the period in which they grew up. This | | |can be a valuable aid in explaining and predicting behavior. Employees in their 60s, for instance, are more | | |likely to accept authority than coworkers 15 years younger. | | | | | |7. Workers under 35 are more likely than the other groups to balk at having to work overtime or weekends, | | |and are more prone to leave a job in mid-career to pursue another that provides more leisure time. | | | | OB IN THE NEWS – American Workers Rethink Priorities Values are relatively permanent, but dramatic shocks can realign them. For example, the terrorists’ attacks on September 11 may have significantly reprioritized many Americans’ values. The initial response to the terrorist attacks for many people was a reevaluation of choices related to jobs, family, and career success. In some cases, this led to a rethinking of career paths, cutting back on grueling schedules, and deciding to pursue work that might pay less but seem more meaningful.For instance, in California, young workers who once talked of dot-com millions are now asking: â€Å"Is it worth it? † Some employees appear less concerned about putting in face time, making deadlines, and getting on the fast track. They seem more concerned about family and worry less about time at the office. CEOs say some of their employees are talking more earnestly about work/life balance, mortality, and other questions once considered taboo in the office. Said one consultant, â€Å"The event de-emphasized what most people value—the money and the luxuries. People are questioning what’s really important; they’re questioning work. It’s happening across the board. † It has now been more than a year since the terrorist attacks on New York and Washington D. C.That provides a more meaningful perspective on whether this event has had long-term implications on workplace values, or whet her any reprioritizing was merely a knee-jerk reaction to a traumatic event, followed by a return to â€Å"business as usual. † Do you think a significant portion of Americans have permanently reprioritized their values as a result of 9-11? Class Exercise: 1. Have students break into small groups to discuss the question: â€Å"Do you think a significant portion of Americans have permanently reprioritized their values as a result of 9-11? † Ask them to list examples of why or why not they think the way they do. 2. As a class, share what was discussed in the small groups. 3. Ask if they think America’s values have changed, or were they just reawakened? 4.Ask if they think organizations’ values have changed or reprioritized as a result of the events. 5. Ask them to relate this question to themselves. Have they reprioritized their lives as a result of the 9-11 events? (They may not want to share this information with the entire class—its purpose is jus t to get them thinking. ) |A. Values, Loyalty, and Ethical Behavior |Notes: | |Many people think there has been a decline in business ethics since the late 1970s. The four-stage model of | | |work cohort values might explain this perception. Exhibit 3-2) | | | | | |Managers consistently report the action of bosses as the most important factor influencing ethical and unethical| | |behavior in the organization. | | | | | |Through the mid-1970s, the managerial ranks were dominated by Veterans whose loyalty was to their employer; | | |their decisions were made in terms of what was best for the employer. | | | | |Boomers entered the workforce at this time and by the 1990’s had risen into the majority of management | | |positions. Loyalty was to their careers. Self-centered values would be consistent with a decline in ethical | | |values. Did this really happen? | | | | | |Recent entrants to the workforce—Xers—are now moving into middle management. Loyalty is to relationships, | | |therefore they may be more likely to consider the ethical implications of their actions on others around them. | |Instructor Note: At this point in the lecture you may want to introduce the Ethical Dilemma: Is it a Bribe or a Gift? Exercise found in the text. The purpose of the exercise is to provide the opportunity for students to understand that ethical situations are not always black or white and must be given consideration as business decisions are made. |B. Values Across Cultures |Notes: | |Values differ across cultures, therefore, understanding these differences helps to explain and to predict | | |behavior of employees from different countries.One of the most widely referenced approaches for analyzing | | |variations among cultures has been done by Geert Hofstede. | | | | | |Hofstede’s A framework for assessing cultures; five value dimensions of national culture (Exhibit 3-4): | | | | | |a.Power distance: | | | | | |The degree to which people i n a country accept that power in institutions and organizations is distributed | | |unequally. | | | | | |Individualism versus collectivism: | | | | |Individualism is the degree to which people in a country prefer to act as individuals rather than as members of | | |groups. | | |Collectivism equals low individualism. | | | | | |Quantity of life versus quality of life: | | | | | |Quantity of life is the degree to which values such as assertiveness, the acquisition of money and material | | |goods, and competition prevail. | |Quality of life is the degree to which people value relationships and show sensitivity and concern for the | | |welfare of others. | | | | | |Uncertainty avoidance: | | | | | |The degree to which people in a country prefer structured over unstructured situations. | | | | |Long-term versus short-term orientation: | | | | | |Long-term orientations look to the future and value thrift and persistence. | | |Short-term orientation values the past and present and emphasizes respect for tradition and fulfilling social | | |obligations. | | | | |Conclusions: | | | | | |Asian countries were more collectivist than individualistic. US ranked highest on individualism. German and | | |Hong Kong ranked highest on quality of life; Russia and The Netherlands were low. China and Hong Kong had a | | |long-term orientation; France and US were low. | | | | |3. Hofstede’s work is the basic framework for assessing cultures. However, it is nearly 30 years old. In | | |1993, the Global Leadership and Organizational Behavior Effectiveness (GLOBE) has begun updating this research | | |with date from 825 organizations and 62 countries. | | | | | |a.GLOBE Framework for Assessing Cultures: | | | | | |Assertiveness: The extent to which a society encourages people to be tough, confrontational, assertive, and | | |competitive versus modest and tender | | | | |Future Orientation: The extent to which a society encourages and rewards future-oriented b ehaviors such as | | |planning, investing in the future and delaying gratification | | | | | |Gender differentiation: The extent to which a society maximized gender role differences | | |Values Across Cultures (cont. |Notes: | | | | |Uncertainly avoidance: Society’s reliance on social norms and procedures to alleviate the unpredictability of | | |future events | | | | | |Power distance: The degree to which members of a society expect power to be unequally shared | | | | | |Individualism/Collectivism: The degree to which individuals are encouraged by societal institutions to be | | |integrated into groups within organizations and society | | | | | |In-group collectivism: The extent to which society’s members take pride in membership in small groups such as | | |their families and circles of close friends, and the organizations where they are employed | | | | | Performance orientation: The degree to which society encourages and rewards group members for performance | | |improvement and excellence | | | | | |Humane orientation: The degree to which a society encourages and rewards individuals for being fair, | | |altruistic, generous, caring, and kind to others | | | | | |b. Conclusion: The GLOBE study had extended Hofstede’s work rather than replaced it. It confirms Hofstede’s | | |five dimensions are still valid and provides updated measures of where countries are on each dimension. For | | |example, the U. S. in the 70s led the world in individualism—today, it is in the mid-ranks of countries. | |Instructor Note: At this point in the lecture you may want to introduce the Team Exercise: Challenges in Negotiating with Chinese Executives found in the text. The purpose of this exercise is to give the students an opportunity to develop awareness of how to effectively work with another culture when doing business. |C. Implications for OB | | |Americans have developed organizational behavior within domestic contexts—mor e than 80 percent of the articles | | |published in journals were by Americans. | | | | |Follow-up studies continue to confirm the lack of cross-cultural considerations in management and OB research. | | |From a cultural perspective this means: | | | | | |Not all OB theories and concepts are universally applicable. | |You should take into consideration cultural values when trying to understand the behavior of people in different| | |countries. | | |Attitudes | | |Attitudes are evaluative statements that are either favorable or unfavorable concerning objects, people, or | | |events. | | | | | |Attitudes are not the same as values, but the two are interrelated. | | | | |Three components of an attitude: | | | | | |Cognition | | |Affect | | |Behavior | | | | |The belief that â€Å"discrimination is wrong† is a value statement and an example of the cognitive component of an | | |attitude. | | |Attitudes (cont. ) |Notes: | |Value statements set the stage for the more critical part of an attitude—its affective component. Affect is the | | |emotional or feeling segment of an attitude. Example: â€Å"I don’t like Jon because he discriminates again | | |minorities. | | | | | |The behavioral component of an attitude refers to an intention to behave in a certain way toward someone or | | |something. Example: â€Å"I chose to avoid Jon because he discriminates. † | | | | | |Viewing attitudes as made up of three components helps with understanding of the potential relationship between | | |attitudes and behavior, however, when we refer to attitude essentially we mean the affect part of the three | | |components. | | | | |In contrast to values, your attitudes are less stable. Advertisements are directed at changing your attitudes | | |and are often successful. | | | | | |In organizations, attitudes are important because they affect job behavior. | | |A. Types of Attitudes | | |OB focuses our attention on a very limited number o f job-related attitudes.Most of the research in OB has been |Notes: | |concerned with three attitudes: job satisfaction, job involvement, and organizational commitment. | | | | | |Job satisfaction | | | | | |Definition: It is an individual’s general attitude toward his/her job. | | | | |A high level of job satisfaction equals positive attitudes toward the job and vice versa. | | | | | |Employee attitudes and job satisfaction are frequently used interchangeably. | | | | | |Often when people speak of â€Å"employee attitudes† they mean â€Å"employee job satisfaction. | | | | | |Job involvement | | | | | |A workable definition: the measure of the degree to which a person identifies psychologically with his/her job | | |and considers his/her perceived performance level important to self-worth. | | | | | |High levels of job involvement is thought to result in fewer absences and lower resignation rates. | | | | | |Job involvement more consistently predicts turnover than absenteeism. | | | | |Organizational commitment | | | | | |Definition: A state in which an employee identifies with a particular organization and its goals, and wishes to| | |maintain membership in the organization. | | | | |Research evidence demonstrates negative relationships between organizational commitment and both absenteeism and| | |turnover. | | | | | |An individual’s level of organizational commitment is a better indicator of turnover than the far more | | |frequently used job satisfaction predictor because it is a more global and enduring response to the organization| | |as a whole than is job satisfaction. | | | | |This evidence, most of which is more than two decades old, needs to be qualified to reflect the changing | | |employee-employer relationship. | | |A. Types of Attitudes (cont. ) |Notes: | |Organizational commitment is probably less important as a job-related attitude than it once was because the | | |unwritten â€Å"loyalty† contract i n place when this research was conducted is no longer in place. | | | | |In its place, we might expect â€Å"occupational commitment† to become a more relevant variable because it better | | |reflects today’s fluid workforce. | | Instructor Note: At this point in the lecture you may want to introduce the exercise Point-Counter Point: Mangers Can Create Satisfied Employees exercise found in the text. The purpose of the exercise is to replace popularly held notions with research-based conclusions. |B. Attitudes and Consistency |Notes: | |People sometimes change what they say so it does not contradict what they do. | | | | |Research has generally concluded that people seek consistency among their attitudes and between their attitudes | | |and their behavior. | | | | | |Individuals seek to reconcile divergent attitudes and align their attitudes and behavior so they appear rational| | |and consistent. | | | | |When there is an inconsistency, forces are initiated to return the individual to an equilibrium state where | | |attitudes and behavior are again consistent, by altering either the attitudes or the behavior, or by developing | | |a rationalization for the discrepancy. | | |C. Cognitive Dissonance Theory | | |Leon Festinger, in the late 1950s, proposed the theory of cognitive dissonance, seeking to explain the linkage | | |between attitudes and behavior. He argued that any form of inconsistency is uncomfortable and that individuals | | |will attempt to reduce the dissonance. | | | | |Dissonance means â€Å"an inconsistency. † | | | | | |Cognitive dissonance refers to â€Å"any incompatibility that an individual might perceive between two or more of | | |his/her attitudes, or between his/her behavior and attitudes. | | | | | |No individual can completely avoid dissonance. | | | | | |The desire to reduce dissonance would be determined by: | | | | | |The importance of the elements creating the dissonance. | | |The degree of infl uence the individual believes he/she has over the elements. | | |The rewards that may be involved in dissonance. | | | | |Importance: If the elements creating the dissonance are relatively unimportant, the pressure to correct this | | |imbalance will be low. | | | | | |Influence: If the dissonance is perceived as an uncontrollable result, they are less likely to be receptive to | | |attitude change. While dissonance exists, it can be rationalized and justified. | | | | |Rewards: The inherent tension in high dissonance tends to be reduced with high rewards. | | | | | |Moderating factors suggest that individuals will not necessarily move to reduce dissonance—or consistency. | | |C. Cognitive Dissonance Theory (cont. ) |Notes: | |Organizational implications | | | | |Greater predictability of the propensity to engage in attitude and behavioral change | | |The greater the dissonance—after it has been moderated by importance, choice, and rewards factors—the gr eater | | |the pressures to reduce it. | | |D. Measuring the A-B Relationship | | |Early research on attitudes and common sense assumed a causal relationship to behavior. In the late 1960s, this| | |assumed relationship between attitudes and behavior (A-B) was challenged. Recent research has demonstrated that| | |attitudes significantly predict future behavior. | | | | |The most powerful moderators: | | | | | |Importance | | |Specificity | | |Accessibility | | |Social pressures | | |Direct experience | | | | | |Importance: Reflects fundamental values, self-interest, or identification with individuals or groups that a | | |person values. | | | | | |Specificity: The more specific the attitude and the more specific the behavior, the stronger the link between | | |the two. | | | | |Accessibility: Attitudes that are easily remembered are more likely to predict behavior than attitudes that are | | |not accessible in memory. | | | | | |Social pressures: Discrepancies between att itudes and behavior are more likely to occur where social pressures | | |to behave in certain ways hold exceptional power. | | | | |Direct experience: The attitude-behavior relationship is likely to be much stronger if an attitude refers to an | | |individual’s direct personal experience. | | |E. Self-perception theory | | |Researchers have achieved still higher correlations by pursuing whether or not behavior influences attitudes. | | | | |Self-perception theory argues that attitudes are used to make sense out of an action that has already occurred | | |rather than devices that precede and guide action. Example: I’ve had this job for 10 years, no one has forced | | |me to stay, so I must like it! | | | | | |Contrary to cognitive dissonance theory, attitudes are just casual verbal statements; they tend to create | | |plausible answers for what has already occurred. | | | | |While the traditional attitude-behavior relationship is generally positive, the behavior- attitude relationship | | |is stronger particularly when attitudes are vague and ambiguous or little thought has been given to it | | |previously. | | |An Application: Attitude Surveys | | |The most popular method for getting information about employee attitudes is through attitude surveys. See | | |Exhibit 3-5) | | | | | |Using attitude surveys on a regular basis provides managers with valuable feedback on how employees perceive | | |their working conditions. Managers present the employee with set statements or questions to obtain specific | | |information. | | | | |Policies and practices that management views as objective and fair may be seen as inequitable by employees in | | |general or by certain groups of employees and can lead to negative attitudes about the job and the organization. | | | | | |Employee behaviors are often based on perceptions, not reality. Often employees do not have objective data from | | |which to base their perceptions. | | | | |The use of regular attitude surveys can alert management to potential problems and employees’ intentions early | | |so that action can be taken to prevent repercussions. | | |G. Attitudes and Workforce Diversity | | |A survey of U. S. organizations with 100 or more employees found that 47 percent or so of them sponsored some | | |sort of diversity training. | | | | |These diversity programs include a self-evaluation phase where people are pressed to examine themselves and to | | |confront ethnic and cultural stereotypes they might hold. This is followed by discussion with people from | | |diverse groups. | | | | | |Additional activities designed to change attitudes nclude arranging for people to do volunteer work in | | |community or social service centers in order to meet face to face with individuals and groups from diverse | | |backgrounds, and using exercises that let participants feel what it is like to be different. | | |Job Satisfaction | | |Measuring Job Satisfaction | | |Job satisfa ction is â€Å"an individual’s general attitude toward his/her job. | | | | | |Jobs require interaction with co-workers and bosses, following organizational rules and policies, meeting | | |performance standards, living with working conditions that are often less than ideal, and the like. This means | | |that an employee’s assessment of how satisfied or dissatisfied he or she is with his/her job is a complex | | |summation of a number of discrete job elements. | | | | |The two most widely used approaches are a single global rating and a summation score made up of a number of job | | |facets. | | | | | |a. The single global rating method is nothing more than asking individuals to respond to one question, such as| | |â€Å"All things considered, how satisfied are you with your job? | | |Measuring Job Satisfaction (cont. ) |Notes: | | A summation of job facets is more sophisticated: | | | | | |It identifies key elements in a job and asks for the employee’s feelings about each one ranked on a standardized| | |scale. | | | | |Typical factors that would be included are the nature of the work, supervision, present pay, promotion | | |opportunities, and relations with co-workers. | | | | | |Comparing these approaches, simplicity seems to work as well as complexity. Comparisons of one-question global | | |ratings with the summation-of-job-factors method indicate both are valid. | |How Satisfied Are People in Their Jobs? | | |Most people are satisfied with their jobs in the developed countries surveyed. | | | | | |However, there has been a decline in job satisfaction since the early 1990s. In the US nearly an eight percent | | |drop in the 90s. Surprisingly those last years were one’s of growth and economic expansion. | | | | |What factors might explain the decline despite growth: | | | | | |Increased productivity through heavier employee workloads and tighter deadlines | | |Employees feeling they have less control over thei r work | | | | | |While some segments of the market are more satisfied than others, they tend to be higher paid, higher skilled | | |jobs which gives workers more control and challenges. | | Instructor Note: At this point in the lecture you may want to introduce the exercise found in the MYTH OR SCIENCE: How Satisfied Are People in Their Jobs? box found in the text.The purpose of the exercise is to replace popularly held notions with research-based conclusions. MYTH OR SCIENCE? – â€Å"Happy Workers Are Productive Workers† This statement is generally false. The myth that â€Å"happy workers are productive workers† developed in the 1930s and 1940s, due to the Hawthorne studies at Western Electric. A careful review of the research indicates that, if there is a positive relationship between happiness (i. e. , satisfaction) and productivity, the correlations are low; no more than two percent of the variance in output can be accounted for by employee satisfaction. The evidence, however, is for the reverse—productive workers are likely to be happy workers.That is, productivity leads to satisfaction rather than the other way around. If the organization rewards productivity, these rewards, in turn, increase your level of satisfaction with the job. Class Exercise 1. Brainstorm with students about situations where they knew workers/employees were unhappy with the company or their jobs, but still did a reasonably good job. Perhaps have them share insights into their own feelings about their school, or a particular class they disliked but still tried very hard. 2. Discuss why someone who is unhappy with his/her job might work hard at it and do good work. 3. Why would someone who is happy with his/her job not perform at a higher level than the disgruntled worker? 4.Students should come to realize that most effort comes from internal drive, not external motivation. As a result, a highly internally motivated individual might perform well in any circumstance whereas his/her organizational environment would not positively affect a non-internally motivated individual. |C. The Effect of Job Satisfaction on Employee Performance |Notes: | |Managers’ interest in job satisfaction tends to center on its effect on employee performance. Much research has| | |been done on the impact of job satisfaction on employee productivity, absenteeism, and turnover. | | | | |Satisfaction and productivity:

Andrew Jackson DBQ Essay

Jackson was a man of many faces, and many of his views were not democratic. First, Jackson was not democratic for economic reasons, such as the Bank veto. Second, Jackson was not democratic for political reasons, such as implementing the Spoils system. Third, Jackson was not democratic for social reasons, such as being pro-slavery. Jacksonian views are not democratic. First, Jackson was not democratic for political reasons. During his presidency many of his actions were viewed as tyrannical and his behavior reflected that of a king rather than of a president. One person drew a cartoon of Jackson, where he is wearing a crown, holding a scepter in his hand, and trampling on the Constitution (Doc 11). This represents that people saw Andrew Jackson as â€Å"King Andrew† because he did whatever he wanted and acted like a dictator by disobeying the Constitution. Another example was when Jackson implemented the Spoils System, which was when the President appointed his supporters with government jobs. Jackson argued that there aren’t many major qualifications necessary for government jobs and that anyone can do it (Doc 4). However, opponents of Jackson considered him a tyrant because he replaced experienced politicians with illiterate farmers who had no political experience just because they supported his campaign. Jackson was not democratic for many political reasons. Second, Jackson was not democratic for economic reasons. To start, Jackson vetoed the bill to recharter the Second Bank of the United States. He claimed that he was protecting the democracy from corruption but in reality, he feared that the bankers would campaign against him. Jackson was a tyrant who destroyed the national bank for personal issues (Doc 8) and he was quoted as saying, â€Å"The Bank is trying to kill me but I will kill it.† Next, Jackson passed the Indian Removal Act, which forced the Indians to move west. Even though the Indians did not want to leave their lands and move into unknown lands, Jackson forced them to (Doc 6). Jackson argued that the white settlers needed the land and could make better use of it and could make the land more economically productive than the Indians had been able  to. Jackson was not democratic for these economic reasons. Third, Jackson was not a democratic president for social reasons. He did not believe in equality for all people. Jackson owned a large number of slaves during his presidency (Doc 5). This shows how Jackson supported slavery and only equality when it referred to white males. Jackson also treated the Native Americans very poorly. Jackson believed that Native Americans were inferior to whites’, and that it was not necessary to treat them fairly. He believed that Native Americans were children in need of guidance (Doc 10). He helped them by â€Å"guiding† them out of their lands and sending them on the Trail of Tears in which more than 4,000 Cherokee die of cold, hunger and disease. Jackson was not a democratic president due to many social reasons.

Phillisophical Analisys

Phillisophical Analisys Nicolo Machiavelli: Basic nature of man- believes it is better to be feared then loved. He believed that we should be avoid being hated. People more quickly forget the death of their father, than the loss of their inheritance.Purpose and aim of state- believes virtues can lead to ones construction, whereas some vices allow one to strive. Virtues, which we commonly praise in people, might lead to their downfall.Structures used to implement the state- believe best to have a reputation of being generous, if generosity is done in secret. Believes those two types of principal government's monarchies and republics.Use in role of law- he became an important diplomat when the Medici family regained power in 1512.Moral or Philosophical Ends To Be Achieved- he developed writings of plays that were historical, political philosophy, and even plays. In the end he ultimately gained favor with the Medici family.David Hume's statements on ethics foreshadowed tho...His greatest work is the prince wri tten in 1513 published after his death in 1532. Its main theme was that princes should retain absolute control over their territories. His work wasn't taken well and soon condemned by the pope.John Locke: Basic Nature of Man- man convinces others that a plot of land is his he combines his labor with his plot and this became property.Purpose and Aim of the State- awareness and reality Structure Used to Implement the State-Locke believes that we can only think about non-mental entities by being aware of mental entities that represent them. In building this relationship he wrote that we must controlled our belief forming capabilities and is our duty to do so.Use in role of law- Locke's second Treatise of Government a defining work in the soon to merge American Government, was based on Locke's concept of natural law.Moral or Philosophical Ends To Be Achieved- The hinge of the work was the concept of private property.Thomas Hobbes: Basic Nature of Man- Hobbes argues that in the absence o f social condition every action we perform no mater how charitable or benevolent, it is done for reasons which are self-serving. Says that people are poor, nasty, brutish, and short at best.Purpose and aim of the state- by the beginning of his residence in Paris 1640 Hobbes had matured the plan for his own philosophical work. It was to consist of three treatises, dealing respectively with matter or body, with human nature, and with society.Structure used to implement the state- Hobbes draws on the language of the natural law tradition of morality.Use in role of law- Hobbes studied the law of heresy and wrote a short treatise on the subject providing that there was no court that he could be judged. Argues that monarchy is the best type of government cause a monarch's interests are the same as the people.Moral or Philosophical Ends To Be Achieved- Sovereign can not be unjust or injure any subject; the sovereign can not be put to death; subject owe him sole loyalty; subjects can not be freed from their obligation; dissenters must consent with the majority in declaring a sovereign; the right to censor doctrines repugnant to peace; legislative power of prescribing rules; judicial power of deciding all controversies; make war and peace with other nations; choose counselors; power of reward and punishment; power of all civil appointments including the militia.Jean-Jacques Rousseau- Basic Nature of Man- said that man is essentially good, a noble savage when in state of nature, and that good people are made unhappy and crupted by their experiences in society. Purpose and Aim of State- he argued that the goal of government should be to secure freedom, equality, and justice for all within the state, regardless of the will of majority. Structure used to implement the State- Rousseau's political philosophy is that politics and morality should not be seperated. When a state fails in a moral fashion, it ceases to function in the proper manor in ceases to exert genuine author ity over the individual. The second most important principal is freedom, which the state is created to preserve.Use in role of law- argued that the advancement of art and science had not been beneficial to mankind. He proposed that the progress of knowledge had made governments more powerful, and crushed individual liberty. He concluded that material progress had actually undermined the possibility of sincere friendship, replacing it with jealousy, fear and suspicion. Moral or Philosophical Ends to be Achieved- Rousseau's ideas about education have profoundly influenced modern educational theory. He minimizes the importance of book learning, and recommends that a child's emotions should be educated before his reason. He placed a special emphasis on learning by experience.David Hume- Basic Nature of Man-Believed humans had passion, free-will and morality, offering original and often skeptical appraisals of these notions.Purpose and Aim of State-By the end of the century, Hume was rec ognized as the founder of the moral theory of Utility. Utilitarian political theorist, Jeremy Bentham, acknowledges Hume's direct influence on him. Hume's Political Discourses drew immediate praise and influenced economic thinkers such as Adam Smith, Godwin and Thomas Malthus.Structures Used to Implement the State-Hume was a candidate for the Chair of Moral Philosophy at the University of Edinburgh. The position was to vacated by John Pringle and leading candidates were Hume and William Cleghorn. The Edinburgh Town Counsel was responsible for electing the replacement. Critics opposed Hume by condemning his anti-religious writings.Use in Role of Law-Hume attacks the character of the clergy, accusing this profession of being motivated by ambition, conceit and revenge.Moral or Philosophical Ends to Be Achieved-Hume offered Rousseau refuge in England and secured him a government pension. In England, Rousseau became suspicious of plots, and publicly charged Hume with conspiring to ruin h is character under the appearance of helping him. Hume published a pamphlet defending his actions and was exonerated. His remaining years were spent refining and revising his published works, and socializing with friends in Edinburgh's intellectual circles. After his death, Hume's name took new significance as several of his previously unpublished works appeared.

Working in Partnership in Health and Social Care essay part 2Essay Writing Service

Working in Partnership in Health and Social Care essay part 2Essay Writing Service Working in Partnership in Health and Social Care essay part 2 Working in Partnership in Health and Social Care essay part 2Working in Partnership in Health and Social Care essay part  1Finally, there are private health and social care models that are funded entirely by private investors. In such a case, the health and social care lies under the full responsibility of privately owned organisations but the government agencies still have the right to monitor their performance to prevent the risk of the violation of human rights of patients or their abuse.However, as a rule, private health care organisations that also provide social care services are responsible because they are interested in the maintenance of the positive public image to attract more customers. Such health and social care organisations often have their own system of monitoring and control to ensure that their health and social care professionals provide patients with care of the high quality. Nevertheless, the government regulatory and controlling agencies should still keep suc h health and social care under control because there is still a probability that they may develop a negligent attitude toward their professional duties that may lead to such cases as was the case of the Mid Staffordshire NHS foundation trust and Adult A.Furthermore, today, the partnership in health and social care are regulated by the Health and Social Care Act of 2012, which regulates health and social care services and creates legal conditions for partnerships in health and social care. However, the Health and Social Care Act of 2012 focuses on setting regulations that will enhance the quality of health and social care with the prioritization of the unification of health and social care. In other words, the current legislation focuses on the merger of health and social care, while they used to develop separately in the past.Moreover, the mid Staffordshire NHS foundation trust and Adult A case has triggered the public debate and forced legislators to launch legal changes to protect patients, in case of professional negligence and under-performance of health and social care organisations and professionals working in those organisations. D. Cameron proposed to improve patient care, increase accountability of hospitals and tackle a culture of â€Å"complacency† in the National Health Service.  He proposed establishing the new post of chief inspector of hospitals (Limentani, 1999).In such a way, new legislative initiatives aim at the enhancement of the government monitoring and control over health and social care and partnerships in this field (Davis, 2006). In this regard, the current legislation provides the basis on the ground of which the further enhancement of the government control and monitoring should be implemented at the legislative level. Organisations operating in health and social care partnerships should be under the government control that decreases the probability of such cases as the Mid Staffordshire NHS foundation trust and Adult A.At the same time, it is worth mentioning the fact that differences in practices and policies in health care and social care have a considerable impact on the collaborative working and partnerships. In fact, the difference in practices and policies lead to substantial communication gaps and misunderstandings between health care and social care professionals.Moreover, such partnerships cannot integrate into their organisational structure that means that health care organisations remain disintegrated from social care organisations because of the differences in their practices and policies. The lack of the integration has a negative impact on the performance of organisations. In such a situation, patients cannot count on stable and reliable health and social care services because some services may overlap, while others may be under-performed.In such a situation, the effectiveness of the partnership in health care and social care decreases because they cannot work as a homogeneous body empl oying the same policies and practices. At this point, it is possible to refer to the case of mid Staffordshire NHS foundation trust and Adult A which has proved the ineffectiveness of such partnership and its failure was, to a significant extent, determined by the differences in practices and policies conducted by health care and social care providers.Section CIn fact, possible outcomes of partnerships in health and social care may be highly controversial. On the one hand, such partnerships have the huge potential. Health and social care partnerships can contribute to the consistent qualitative improvement of both health and social care. Isolated, social and health care services are less effective because they cannot always complement each other. On the contrary, health care organisations offer a set of health care services, while social care organisations offer their services which are not always related to health care services received by patients. In case of partnerships, patient s can enjoy health and social care services that complement each other. What is meant here is the fact that patients receiving health care services can also receive those social care services that match their current needs in terms of their health condition, ability/disability, and overall physical or mental health.On the other hand, the risk of such cases as was the case of the mid Staffordshire NHS foundation trust and Adult A persists. This is why partnerships may lead to the deception of patients, violation of their basic human rights, neglect and even death. In such a context, partnerships in health and social care often confront severe criticism from the part of the public as well as professionals working in both fields, i.e. health care and social care. The major source of criticism is the possibility of avoiding the just legal action, in case of the violation of partnerships or insufficient or ineffective performances in terms of partnerships. At this point, it is also worth mentioning the fact that partners may repose the responsibility on each other. For example, health care organisation may justify persisting health problems of a patient by poor social care services and, on the contrary, social care professionals can explain the failure of their performance by the poor health of clients and under-performance of health care professionals.The major potential barriers to partnerships in health and social care are closely intertwined with the difference in practices and policies conducted by health care and social care organisations. Many researchers (Coddington, Fischer,   Moore, 2000) point out that the difference in practices and policies persists today and has a considerable impact on the performance of health and social care partnerships.Furthermore, communication gaps may also raise barriers on the way to the effective partnership between health and social care. In actuality, communication gaps are particularly dangerous for the overall success of health and social care partnerships because the poor communication prevents partners from the effective interaction. As a result, organisations comprising the partnership under-perform. For example, health care professionals may provide incomplete information to social workers on a patient and social workers may fail to meet needs of the patient to the full extent. Similarly, the lack of information on social conditions and conditions of living of the patents may lead to the ineffective treatment since health care professionals cannot take into consideration all factors that may influence the health condition of their patient.At the same time, barriers may arise in the result of certain overlapping of functions, when health care professionals and organisations may believe that social care professionals and organisations interfere into their domain and vice versa. Therefore, they need to distribute functions clearly. In addition, the overlapping of functions increases costs of bot h health and social care that is absolutely unacceptable, when the costs of health care services are already high.Nevertheless, it is obvious that partnerships in health and social care may be effective. In this respect, it is possible to recommend several strategies to enhance such partnerships and make them more effective than they are at the moment. First, health care and social care organisations should eliminate differences in their practices and policies. The elimination of the differences may involve the development of common standards and reorganisation and restructuring that helps organisation to elaborate the common organisational structure, distribute functions effectively and provide clients with health and social care services of the high quality.Second, the close integration of health care and social care organisation should lead to the steady elimination of the frontline between them that means that health care professionals should be able to deliver basic social care services, while social workers should be able to deliver basic health care services. Such integration of health and social care professionals can help them to understand each other better. Therefore, they will be able to interact with each other better because they will understand what each other do and how they do it.Third, the enhancement of monitoring and control over health and social care partnership is essential but such monitoring and control should not be bound to the government monitoring and control only. Instead, independent auditing may be needed, including the involvement of auditing agencies as well as public organisations which may monitor the performance of health and social care partnerships effectively and professionally.   The monitoring and control will prevent such cases as the Mid Staffordshire NHS foundation trust and Adult A case. At any rate, the risk of occurrence of such cases will drop substantially, if health and social care organisations remain under the permanent monitoring and control from the part of the government agencies.Finally, the improvement of health and social care partnership should start with the close collaboration of professionals working in these two fields. Health care professionals should work hand in hand with social workers. In such a way, they will not only share their experience but they will also learn to understand each other better as they know how they work and what challenges they confront. The close cooperation helps health and social care professionals to understand specificities of their job and, thus, understand each other better.ConclusionThus, the case of the mid Staffordshire NHS foundation trust and Adult A reveals the full extent to which the current legislation concerning health and social care in the UK is imperfect. At the same time, the partnership in health and social care is still very prospective. This is why policy makers should consider possibilities of the improvement of such partn erships and enhancement of the government and public control over their performance.

Relationship between body image and self-esteem among adolescent girls Essay

Relationship between body image and self-esteem among adolescent girls - Essay Example This paper illustrates that lower levels of self-esteem and poor body image are clearly documented in the general literature as the significant cause of the concern among many adolescent girls. The first area of the review outlines the impact and emotional development of body image and self-esteem. The chapter then goes ahead to outline the immediate influence of family followed by an analysis of how the peers and the media impact self-esteem as well as body image. Importance of the article: Having a distorted body image among girls who are at the adolescent age have been linked to the advancement of dysfunctional eating pattern and disorders such as Anorexia Nervosa, Binge eating disorder or even Bulimia Nervosa. The self-esteem is so important factor; based on the research which shows that it is directly related to one’s personal image and how adolescent girls perceive themselves. It is quite clear and very necessary to know that, self-esteem corresponds with the emotional a s well, as the physical development, can directly affect an adolescent girl in either a positive or a negative way. Purpose of the study: The main purpose of the literature review is to determine whether a relationship exists between self-esteem and body image among adolescent girls. The self-esteem should never below for anyone who wishes to accept his or her self-personality, thus the study focuses on al the aspect which is deemed necessary for overcoming the challenge imposed by lack of this self-esteem and image. Procedures and steps: The study was based on the systematic approach, whereby different respondent was interviewed using both orally and written questioners, this facilitated the acquisition of information so efficiently and giving most accurate data that would be relayed upon in assessing the situation on the ground. Once the data was collected, it was critically analyzed to come up with the conclusion as well as the relevant recommendations. Important information is g iven more emphasis and much weight so as to avoid biases in coming up with the conclusion as well as the recommendation which shall be relied upon by the readers of the article. Participants: Considering the research conducted in schools as well as other social places, revealed a clear picture of how these two elements are affecting many teenagers both in their social and ordinary way of life. The study was conducted based on a random sampling to analyze the different perspectives as well as opinions that all these groups of personalities. As the estimate of 60% of the population visited was analyzed to determine the information necessary f r the research. For instance, the survey conducted Association of University Women showed that only 29% of the girls who were served did express self-satisfaction, while more than half of the boys did feel so good about themselves.

The necessity of human resource management Essay

The necessity of human resource management - Essay Example It helps in determination of objectives. No organization can succeed in its mission unless its objectives an identified and well denied. Management helps in achieving these objectives by the efficient use of resources. "Management is the art of getting things done through other people. Management is the dynamic, life-giving element in every business. Without it the resources of production remain resources and never become production." (Sharma, 2004) The people working in an organization are a valuable resource whose talents have to be developed and utilized in the best manner possible for the achievements of organizational objectives (Sherlekar, 1999). Meaningful personnel policy is based on the implied understanding that human resource constitutes the essential capital and assets of any business. Without this no business can prosper nor can it survive. The growth and success of the enterprise and the rate of human investment have positive and high correlation. If human investment is adequate and time, money and energy spent in planning, obtaining and developing the human resource are considered as integral part of overall corporate plan and policy, there is no reason why economic investment should not be fruitful (David et al, 2004) Firstly, management is a social process. ... Management is concerned with making such an interaction productive and useful for achieving organizational goals. It is the pervasiveness of the human element that gives management its special character as a social process. Secondly, management is an integrating process. Management is regarded as a process integrating human and other resources to achieve predetermined goals. Managers apply their knowledge and skills to achieve the desired result. For this purpose, it is necessary to create unity of effort or teamwork in the organization. In order to develop team spirit, managers has to synchronies different activities, relate means to ends, and strike an appropriate balance between organizational and individual goals. Thus management is regarded as an integrating process. Thirdly, management is a continuous process Management is an ongoing continuous process. It involves continuous handling of problems and issues. Management constantly identifies the problems and tries to solve them (Sherlekar, 1999). 4.0 Staffing Staffing may be defined as the process involved in identifying, assessing, planning, evaluating and developing individuals at work. The managerial function of staffing involves manning the organizational structure through the proper and effective selection, appraisal and development of personnel to fill the roles designed into the structure. 4.1 Phases in Staffing Process 4.1.1 Manpower Planning Manpower planning may be regarded, as a process of determining quantitative and qualitative needs in relation to manpower in an organization. It may be expressed as a process by which the management ensures the right number of people and right kind of people, at the right place, at the right time