Friday, November 29, 2019

Solar Water Purifier free essay sample

BACKGROUND INFORMATION4 STATEMENT OF THE PROBLEM4 Objectives4 Justifications and significance4 Limitations4 Precautions5 Advantages5 CHAPTER 26 Literature review6 CHAPTER 37 Methodology7 Apparatus7 Procedure7 Observations7 CHAPTER 49 DATA ANALYSIS AND INTERPRETATION9 CHAPTER 510 CONCLUSION AND RECOMMENDATION10 REFERENCES10 CHAPTER 1: ABSTRACT BACKGROUND INFORMATION Solar water purifier is a device that purifies water through solar energy. Dirty water is a key link in the cycle of water borne diseases that affects the worlds’ poorest day who would otherwise contribute more to the overall economic and social development. Improved solar water purifier directly impacts on achieving universal education and reducing the rate of mortality. Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids and gases from contaminated water. The goal is to produce water fit for a specific purpose. Most water is purified for human consumption (drinking water), but water purification may also be designed for a variety of other purposes, including meeting the requirements of medical, pharmacological, chemical and industrial applications. We will write a custom essay sample on Solar Water Purifier or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page In general the methods used include physical processes such as filtration, sedimentation, and distillation, biological processes such as slow sand filters or biologically active carbon, chemical processes such as flocculation and chlorination and the use of electromagnetic radiation such as ultraviolet light. The purification process of water may reduce the concentration of particulate matter including suspended particles, parasites, bacteria, algae, viruses, fungi; and a range of dissolved and particulate material derived from the surfaces that water may have made contact with after falling as rain. The standards for drinking water quality are typically set by governments or by international standards. These standards will typically set minimum and maximum concentrations of contaminants for the use that is to be made of the water. It is not possible to tell whether water is of an appropriate quality by visual examination. Simple procedures such as boiling or the use of a household activated carbon filter are not sufficient for treating all the possible contaminants that may be present in water from an unknown source. Even natural spring water – considered safe for all practical purposes in the 19th century – must now be tested before determining what kind of treatment, if any, is needed. Chemical and microbiological analysis, while expensive, are the only way to obtain the information necessary for deciding on the appropriate method of purification. According to a 2007 World Health Organization (WHO) report, 1. 1 billion people lack access to an improved drinking water supply, 88 percent of the 4 billion annual cases of diarrheal disease are attributed to unsafe water and inadequate sanitation and hygiene, and 1. million people die from diarrheal diseases each year. The WHO estimates that 94 percent of these diarrheal cases are preventable through modifications to the environment, including access to safe water. [1] Simple techniques for treating water at home, such as chlorination, filters, and solar disinfection, and storing it in safe containers could save a huge number of lives each year. [2] Reducing deaths from waterborne diseases is a major public health goal in developing countries. STATEMENT OF THE PROBLEM The rate at which flooding occurs especially this season is rising at an alarming rate . Places such as Kano plains, Tana river , Budalangi are experiencing high levels of flooding. The water from floods may come across open sewerages, decaying organism and garbage which contaminate water sources. Such water is not healthy for human consumption. Approximately 1. 8 million people die due to diarrhoeal diseases such as cholera every year. Access to clean water is one of the global issues affecting the world and will continue to be so, as demand increases. Objectives 1 . Reduce intake and usage of dirty water domestically. 2. Reduce the number of medical cases brought about by intake of dirty water. 3. Introduction of a method of water purification which requires less human labour and its environment friendly. 4. To put an end to usage of chemicals in water purification which maybe a health hazard. Justifications and significance 1. It enables Kenyans to use clean water and minimize the medical cases brought about by dirty water. 2. It minimizes the rate at which people die due to water borne diseases. Limitations 1. It can’t work when the saturation deficit is low in the atmosphere. . It tends to be slow. 3. It is not portable. Precautions 1. It should be handled with care as it tends to be delicate. Advantages 1. It continues to work when sun rays are cut off because the black coating tends to lose heat at a lower intensity which can’t penetrate through the glass thus heat is retained. 2. Energy is readily available and renewable which is the sun. 3. The materials that are used to build it are locally available and at an affordable cost. 4. Its efficient and healthy as the water is purified at the end of the process. 5. Its environmental friendly as it doesn’t pollute the environment 6. It is ideal for the arid and semi –arid areas where there are high temperatures. CHAPTER 2 Literature review Sources of water Further information: Water supply 1. Groundwater: The water emerging from some deep ground water may have fallen as rain many tens, hundreds, or thousands of years ago. Soil and rock layers naturally filter the ground water to a high degree of clarity and often it does not require additional treatment other than adding chlorine or chloramines as secondary disinfectants. Such water may emerge as springs, artesian springs, or may be extracted from boreholes or wells. Deep ground water is generally of very high bacteriological quality (i. e. , pathogenic bacteria or the pathogenic protozoa are typically absent), but the water may be rich in dissolved solids, especially carbonates and sulfates of calcium and magnesium. Depending on the strata through which the water has flowed, other ions may also be present including chloride, and bicarbonate. There may be a requirement to reduce the iron or manganese content of this water to make it acceptable for drinking, cooking, and laundry use. Primary disinfection may also be required. Where groundwater recharge is practised (a process in which river water is injected into an aquifer to store the water in times of plenty so that it is available in times of drought), the groundwater may require additional treatment depending on applicable state and federal regulations. 2. Upland lakes and reservoirs: Typically located in the headwaters of river systems, upland reservoirs are usually sited above any human habitation and may be surrounded by a protective zone to restrict the opportunities for contamination. Bacteria and pathogen levels are usually low, but some bacteria, protozoa or algae will be present. Where uplands are forested or peaty, humic acids can colour the water. Many upland sources have low pH which require adjustment. 3. Rivers, canals and low land reservoirs: Low land surface waters will have a significant bacterial load and may also contain algae, suspended solids and a variety of dissolved constituents. 4. Atmospheric water generation is a new technology that can provide high quality drinking water by extracting water from the air by cooling the air and thus condensing water vapor. . Rainwater harvesting or fog collection which collects water from the atmosphere can be used especially in areas with significant dry seasons and in areas which experience fog even when there is little rain. 6. Desalination of seawater by distillation or reverse osmosis. 7. Surface Water: Freshwater bodies that are open to the atmosphere and are not designated as groundwater are classified i n the USA for regulatory and water purification purposes as surface water. Treatment The processes below are the ones commonly used in water purification plants. Some or most may not be used depending on the scale of the plant and quality of the raw (source) water. Pre-treatment 1. Pumping and containment – The majority of water must be pumped from its source or directed into pipes or holding tanks. To avoid adding contaminants to the water, this physical infrastructure must be made from appropriate materials and constructed so that accidental contamination does not occur. 2. Screening (see also screen filter) – The first step in purifying surface water is to remove large debris such as sticks, leaves, rubbish and other large particles which may interfere with subsequent purification steps. Most deep groundwater does not need screening before other purification steps. 3. Storage – Water from rivers may also be stored in backside reservoirs for periods between a few days and many months to allow natural biological purification to take place. This is especially important if treatment is by slow sand filters. Storage reservoirs also provide a buffer against short periods of drought or to allow water supply to be maintained during transitory pollution incidents in the source river. 4. Pre-chlorination – In many plants the incoming water was chlorinated to minimize the growth of fouling organisms on the pipe-work and tanks. Because of the potential adverse quality effects (see chlorine below), this has largely been discontinued. Widely varied techniques are available to remove the fine solids, micro-organisms and some dissolved inorganic and organic materials. The choice of method will depend on the quality of the water being treated, the cost of the treatment process and the quality standards expected of the processed water. H adjustment Pure water has a pH close to 7 (neither alkaline nor acidic). Sea water can have pH values that range from 7. 5 to 8. 4 (moderately alkaline). Fresh water can have widely ranging pH values depending on the geology of the drainage basin or aquifer and the influence of contaminant inputs (acid rain). If the water is acidic (lower than 7), lime, soda ash, or sodium hydroxide can be added to raise the pH during water purificati on processes. Lime addition increases the calcium ion concentration, thus raising the water hardness. For highly acidic waters, forced draft degasifiers can be an effective way to raise the pH, by stripping dissolved carbon dioxide from the water. Making the water alkaline helps coagulation and flocculation processes work effectively and also helps to minimize the risk of lead being dissolved from lead pipes and from lead solder in pipe fittings. Sufficient alkalinity also reduces the corrosiveness of water to iron pipes. Acid ( carbonic acid, hydrochloric acid or sulfuric acid) may be added to alkaline waters in some circumstances to lower the pH. Alkaline water (above pH 7. 0) does not necessarily mean that lead or copper from the plumbing system will not be dissolved into the water. The ability of water to precipitate calcium carbonate to protect metal surfaces and reduce the likelihood of toxic metals being dissolved in water is a function of pH, mineral content, temperature, alkalinity and calcium concentration. Coagulation and flocculation One of the first steps in a conventional water purification process is the addition of chemicals to assist in the removal of particles suspended in water. Particles can be inorganic such as clay and silt or organic such as algae, bacteria, viruses, protozoa and natural organic matter. Inorganic and organic particles contribute to the turbidity and colour of water. The addition of inorganic coagulants such as aluminum sulfate (or alum) or iron (III) salts such as iron(III) chloride cause several simultaneous chemical and physical interactions on and among the particles. Within seconds, negative charges on the particles are neutralized by inorganic coagulants. Also within seconds, metal hydroxide precipitates of the aluminum and iron (III) ions begin to form. These precipitates combine into larger particles under natural processes such as Brownian motion and through induced mixing which is sometimes referred to as flocculation. The term most often used for the amorphous metal hydroxides is â€Å"floc. † Large, amorphous aluminum and iron (III) hydroxides adsorb and enmesh particles in suspension and facilitate the removal of particles by subsequent processes of sedimentation and filtration. Aluminum hydroxides are formed within a fairly narrow range, typically: 5. 5 to about 7. 7. Iron (III) hydroxides can form over a larger pH range including pH levels lower than are effective for alum, typically: 5. 0 to 8. 5. In the literature, there is much debate and confusion over the usage of the terms coagulation and flocculation—where does coagulation end and flocculation begin? In water purification plants, there is usually a high energy, rapid mix unit process (detention time in seconds) where the coagulant chemicals are added followed by flocculation basins (detention times range from 15 to 45 minutes) where low energy inputs turn large paddles or other gentle mixing devices to enhance the formation of floc. In fact, coagulation and flocculation processes are ongoing once the metal salt coagulants are added. [10]:74-5 Organic polymers were developed in the 1960s as aids to coagulants and, in some cases, as replacements for the inorganic metal salt coagulants. Synthetic organic polymers are high molecular weight compounds that carry negative, positive or neutral charges. When organic polymers are added to water with particulates, the high molecular weight compounds adsorb onto particle surfaces and through antiparticle bridging coalesce with other particles to form floc. PolyDADMAC is a popular cationic (positively charged) organic polymer used in water purification plants. [9]:667-8 Sedimentation Waters exiting the flocculation basin may enter the sedimentation basin, also called a clarifier or settling basin. It is a large tank with low water velocities, allowing floc to settle to the bottom. The sedimentation basin is best located close to the flocculation basin so the transit between the two processes does not permit settlement or floc break up. Sedimentation basins may be rectangular, where water flows from end to end, or circular where flow is from the centre outward. Sedimentation basin outflow is typically over a weir so only a thin top layer of water—that furthest from the sludge—exits. In 1904, Allen Hazen showed that the efficiency of a sedimentation process was a function of the particle settling velocity, the flow through the tank and the surface area of tank. Sedimentation tanks are typically designed within a range of overflow rates of 0. 5 to 1. 0 gallons per minute per square foot (or 1. 25 to 2. 5 meters per hour). In general, sedimentation basin efficiency is not a function of detention time or depth of the basin. Although, basin depth must be sufficient so that water currents do not disturb the sludge and settled particle interactions are promoted. As particle concentrations in the settled water increase near the sludge surface on the bottom of the tank, settling velocities can increase due to collisions and agglomeration of particles. Typical detention times for sedimentation vary from 1. 5 to 4 hours and basin depths vary from 10 to 15 feet (3 to 4. 5 meters). [8]:9. 39-9. 40[9]:790-1[10]:140-2, 171 Inclined flat plates or tubes can be added to traditional sedimentation basins to improve particle removal performance. Inclined plates and tubes drastically increase the surface area available for particles to be removed in concert with Hazen’s original theory. The amount of ground surface area occupied by a sedimentation basin with inclined plates or tubes can be far smaller than a conventional sedimentation basin. Sludge storage and removal As particles settle to the bottom of a sedimentation basin, a layer of sludge is formed on the floor of the tank. This layer of sludge must be removed and treated. The amount of sludge that is generated is significant, often 3 to 5 percent of the total volume of water that is treated. The cost of treating and disposing of the sludge can be a significant part of the operating cost of a water treatment plant. The sedimentation tank may be equipped with mechanical cleaning devices that continually clean the bottom of the tank or the tank can be periodically taken out of service and cleaned manually. Floc blanket clarifiers A subcategory of sedimentation is the removal of particulates by entrapment in a layer of suspended floc as the water is forced upward. The major advantage of floc blanket clarifiers is that they occupy a smaller footprint than conventional sedimentation. Disadvantages are that particle removal efficiency can be highly variable depending on changes in influent water quality and influent water flow rate. [9]:835-6 Dissolved air flotation When particles to be removed do not settle out of solution easily, dissolved air flotation (DAF) is often used. Water supplies that are particularly vulnerable to unicellular algae blooms and supplies with low turbidity and high colour often employ DAF. After coagulation and flocculation processes, water flows to DAF tanks where air diffusers on the tank bottom create fine bubbles that attach to floc resulting in a floating mass of concentrated floc. The floating floc blanket is removed from the surface and clarified water is withdrawn from the bottom of the DAF tank. [8]:9. 46 Filtration After separating most floc, the water is filtered as the final step to remove remaining suspended particles and unsettled floc. Rapid sand filters Cutaway view of a typical rapid sand filter The most common type of filter is a rapid sand filter. Water moves vertically through sand which often has a layer of activated carbon or anthracite coal above the sand. The top layer removes organic compounds, which contribute to taste and odour. The space between sand particles is larger than the smallest suspended particles, so simple filtration is not enough. Most particles pass through surface layers but are trapped in pore spaces or adhere to sand particles. Effective filtration extends into the depth of the filter. This property of the filter is key to its operation: if the top layer of sand were to block all the particles, the filter would quickly clog. [11] To clean the filter, water is passed quickly upward through the filter, opposite the normal direction (called backflushing or backwashing) to remove embedded particles. Prior to this step, compressed air may be blown up through the bottom of the filter to break up the compacted filter media to aid the backwashing process; this is known as air scouring. This contaminated water can be disposed of, along with the sludge from the sedimentation basin, or it can be recycled by mixing with the raw water entering the plant although this is often considered poor practice since it re-introduces an elevated concentration of bacteria into the raw water Some water treatment plants employ pressure filters. These work on the same principle as rapid gravity filters, differing in that the filter medium is enclosed in a steel vessel and the water is forced through it under pressure. Advantages: †¢Filters out much smaller particles than paper and sand filters can. †¢Filters out virtually all particles larger than their specified pore sizes. †¢They are quite thin and so liquids flow through them fairly rapidly. †¢They are reasonably strong and so can withstand pressure differences across them of typically 2–5 atmospheres. †¢They can be cleaned (back flushed) and reused. Slow sand filters Slow artificial filtration (a variation of bank filtration) to the ground, Water purification plant Karany, Czech Republic Slow sand filters may be used where there is sufficient land and space, as the water must be passed very slowly through the filters. These filters rely on biological treatment processes for their action rather than physical filtration. The filters are carefully constructed using graded layers of sand, with the coarsest sand, along with some gravel, at the bottom and finest sand at the top. Drains at the base convey treated water away for disinfection. Filtration depends on the development of a thin biological layer, called the zoogleal layer or Schmutzdecke, on the surface of the filter. An effective slow sand filter may remain in service for many weeks or even months if the pre-treatment is well designed and produces water with a very low available nutrient level which physical methods of treatment rarely achieve. Very low nutrient levels allow water to be safely sent through distribution systems with very low disinfectant levels, thereby reducing consumer irritation over offensive levels of chlorine and chlorine by-products. Slow sand filters are not backwashed; they are maintained by having the top layer of sand scraped off when flow is eventually obstructed by biological growth. [citation needed] A specific large-scale form of slow sand filter is the process of bank filtration, in which natural sediments in a riverbank are used to provide a first stage of contaminant filtration. While typically not clean enough to be used directly for drinking water, the water gained from the associated extraction wells is much less problematic than river water taken directly from the major streams where bank filtration is often used. Membrane filtration Membrane filters are widely used for filtering both drinking water and sewage. For drinking water, membrane filters can remove virtually all particles larger than 0. 2 um—including giardia and cryptosporidium. Membrane filters are an effective form of tertiary treatment when it is desired to reuse the water for industry, for limited domestic purposes, or before discharging the water into a river that is used by towns further downstream. They are widely used in industry, particularly for beverage preparation (including bottled water). However no filtration can remove substances that re actually dissolved in the water such as phosphorus, nitrates and heavy metal ions. Removal of ions and other dissolved substances Ultrafiltration membranes use polymer membranes with chemically formed microscopic pores that can be used to filter out dissolved substances avoiding the use of coagulants. The type of membrane media determines how much pressure is needed to drive t he water through and what sizes of micro-organisms can be filtered out. Ion exchange:[12] Ion exchange systems use ion exchange resin- or zeolite-packed columns to replace unwanted ions. The most common case is water softening consisting of removal of Ca2+ and Mg2+ ions replacing them with benign (soap friendly) Na+ or K+ ions. Ion exchange resins are also used to remove toxic ions such as nitrate, nitrite, lead, mercury, arsenic and many others. Precipitative softening:[8]:13. 12-13. 58 Water rich in hardness (calcium and magnesium ions) is treated with lime (calcium oxide) and/or soda-ash (sodium carbonate) to precipitate calcium carbonate out of solution utilizing the common-ion effect. Electrodeionization:[12] Water is passed between a positive electrode and a negative electrode. Ion exchange membranes allow only positive ions to migrate from the treated water toward the negative electrode and only negative ions toward the positive electrode. High purity deionized water is produced with a little worse degree of purification in comparison with ion exchange treatment. Complete removal of ions from water is regarded as electrodialysis. The water is often pre-treated with a reverse osmosis unit to remove non-ionic organic contaminants. Disinfection Disinfection is accomplished both by filtering out harmful micro-organisms and also by adding disinfectant chemicals. Water is disinfected to kill any pathogens which pass through the filters and to provide a residual dose of disinfectant to kill or inactivate potentially harmful micro-organisms in the storage and distribution systems. Possible pathogens include viruses, bacteria, including Salmonella, Cholera, Campylobacter and Shigella, and protozoa, including Giardia lamblia and other cryptosporidia. Following the introduction of any chemical disinfecting agent, the water is usually held in temporary storage – often called a contact tank or clear well to allow the disinfecting action to complete. Chlorine disinfection Main article: Water chlorination The most common disinfection method involves some form of chlorine or its compounds such as chloramine or chlorine dioxide. Chlorine is a strong oxidant that rapidly kills many harmful micro-organisms. Because chlorine is a toxic gas, there is a danger of a release associated with its use. This problem is avoided by the use of sodium hypochlorite, which is a relatively inexpensive solution that releases free chlorine when dissolved in water. Chlorine solutions can be generated on site by electrolyzing common salt solutions. A solid form, calcium hypochlorite, releases chlorine on contact with water. Handling the solid, however, requires greater routine human contact through opening bags and pouring than the use of gas cylinders or bleach which are more easily automated. The generation of liquid sodium hypochlorite is both inexpensive and safer than the use of gas or solid chlorine. All forms of chlorine are widely used, despite their respective drawbacks. One drawback is that chlorine from any source reacts with natural organic compounds in the water to form potentially harmful chemical by-products. These by-products, trihalomethanes (THMs) and haloacetic acids (HAAs), are both carcinogenic in large quantities and are regulated by the United States Environmental Protection Agency (EPA) and the Drinking Water Inspectorate in the UK. The formation of THMs and haloacetic acids may be minimized by effective removal of as many organics from the water as possible prior to chlorine addition. Although chlorine is effective in killing bacteria, it has limited effectiveness against protozoa that form cysts in water (Giardia lamblia and Cryptosporidium, both of which are pathogenic). Chlorine dioxide disinfection Chlorine dioxide is a faster-acting disinfectant than elemental chlorine, however it is relatively rarely used, because in some circumstances it may create excessive amounts of chlorite, which is a by-product regulated to low allowable levels in the United States. Chlorine dioxide is supplied as an aqueous solution and added to water to avoid gas handling problems; chlorine dioxide gas accumulations may spontaneously detonate. Chloramine disinfection The use of chloramine is becoming more common as a disinfectant. Although chloramine is not as strong an oxidant, it does provide a longer-lasting residual than free chlorine and it wont form THMs or haloacetic acids. It is possible to convert chlorine to chloramine by adding ammonia to the water after addition of chlorine. The chlorine and ammonia react to form chloramine. Water distribution systems disinfected with chloramines may experience nitrification, as ammonia is a nutrient for bacterial growth, with nitrates being generated as a by-product. Ozone disinfection Ozone is an unstable molecule which readily gives up one atom of oxygen providing a powerful oxidizing agent which is toxic to most waterborne organisms. It is a very strong, broad spectrum disinfectant that is widely used in Europe. It is an effective method to inactivate harmful protozoa that form cysts. It also works well against almost all other pathogens. Ozone is made by passing oxygen through ultraviolet light or a cold electrical discharge. To use ozone as a disinfectant, it must be created on-site and added to the water by bubble contact. Some of the advantages of ozone include the production of fewer dangerous by-products and the absence of taste and odour problems (in comparison to chlorination) . Although fewer by-products are formed by ozonation, it has been discovered that ozone reacts with bromide ions in water to produces concentrations of the suspected carcinogen bromate. Bromide can be found in fresh water supplies in sufficient concentrations to produce (after ozonation) more than 10 ppb of bromate — the maximum contaminant level established by the USEPA. [13] Another advantage of ozone is that it leaves no residual disinfectant in the water. Ozone has been used in drinking water plants since 1906 where the first industrial ozonation plant was built in Nice, France. The U. S. Food and Drug Administration has accepted ozone as being safe; and it is applied as an anti-microbiological agent for the treatment, storage, and processing of foods. Ultraviolet disinfection Ultraviolet light (UV) is very effective at inactivating cysts, in low turbidity water. UV lights disinfection effectiveness decreases as turbidity increases, a result of the absorption, scattering, and shadowing caused by the suspended solids. The main disadvantage to the use of UV radiation is that, like ozone treatment, it leaves no residual disinfectant in the water; therefore, it is sometimes necessary to add a residual disinfectant after the primary disinfection process. This is often done through the addition of chloramines, discussed above as a primary disinfectant. When used in this manner, chloramines provide an effective residual disinfectant with very few of the negative aspects of chlorination. Various portable methods of disinfection Main article: Portable water purification Available for disinfection in emergencies or in remote locations. Disinfection is the primary goal, since aesthetic considerations such as taste, odor, appearance, and trace chemical contamination do not affect the short-term safety of drinking water. Solar water disinfection One low-cost method of disinfecting water that can often be implemented with locally available materials is solar disinfection (SODIS). [14][15][16][17] [18] Unlike methods that rely on firewood, it has low impact on the environment. One recent study has found that the wild Salmonella which would reproduce quickly during subsequent dark storage of solar-disinfected water could be controlled by the addition of just 10 parts per million of hydrogen peroxide. [19] Additional treatment options 1. Water fluoridation: in many areas fluoride is added to water with the goal of preventing tooth decay. Fluoride is usually added after the disinfection process. In the U. S. , fluoridation is usually accomplished by the addition of hexafluorosilicic acid, which decomposes in water, yielding fluoride ions. 2. Water conditioning: This is a method of reducing the effects of hard water. In water systems subject to heating hardness salts can be deposited as the decomposition of bicarbonate ions creates carbonate ions that precipitate out of solution. Water with high concentrations of hardness salts can be treated with soda ash (sodium carbonate) which precipitates out the excess salts, through the common-ion effect, producing calcium carbonate of very high purity. The precipitated calcium carbonate is traditionally sold to the manufacturers of toothpaste. Several other methods of industrial and residential water treatment are claimed (without general scientific cceptance) to include the use of magnetic and/or electrical fields reducing the effects of hard water. ] 3. Plumbosolvency reduction: In areas with naturally acidic waters of low conductivity (i. e. surface rainfall in upland mountains of igneous rocks), the water may be capable of dissolving lead from any lead pipes that it is carried in. The addition of small quantities of phosphate ion and increasing the pH slightly both assist in greatly reducing plumbo-solvency by creating insoluble lead salts on the inner surfaces of the pipes. 4. Radium Removal: Some groundwater sources contain radium, a radioactive chemical element. Typical sources include many groundwater sources north of the Illinois River in Illinois. Radium can be removed by ion exchange, or by water conditioning. The back flush or sludge that is produced is, however, a low-level radioactive waste. 5. Fluoride Removal: Although fluoride is added to water in many areas, some areas of the world have excessive levels of natural fluoride in the source water. Excessive levels can be toxic or cause undesirable cosmetic effects such as staining of teeth. Methods of reducing fluoride levels is through treatment with activated alumina and bone char filter media. Other water purification techniques Other popular methods for purifying water, especially for local private supplies are listed below. In some countries some of these methods are also used for large scale municipal supplies. Particularly important are distillation (de-salination of seawater) and reverse osmosis. 1. Boiling: Water is heated hot enough and long enough to inactivate or kill micro-organisms that normally live in water at room temperature. Near sea level, a vigorous rolling boil for at least one minute is sufficient. At high altitudes (greater than two kilometres or 5000 feet) three minutes is recommended. 23] In areas where the water is hard (that is, containing significant dissolved calcium salts), boiling decomposes the bicarbonate ions, resulting in partial precipitation as calcium carbonate. This is the fur that builds up on kettle elements, etc. , in hard water areas. With the exception of calcium, boiling does not remove solutes of higher boiling point than water a nd in fact increases their concentration (due to some water being lost as vapour). Boiling does not leave a residual disinfectant in the water. Therefore, water that is boiled and then stored for any length of time may acquire new pathogens. . Granular Activated Carbon filtering: a form of activated carbon with a high surface area, adsorbs many compounds including many toxic compounds. Water passing through activated carbon is commonly used in municipal regions with organic contamination, taste or odors. Many household water filters and fish tanks use activated carbon filters to further purify the water. Household filters for drinking water sometimes contain silver as metallic silver nanoparticle. If water is held in the carbon block for longer period, microorganisms can grow inside which results in fouling and contamination. Silver nanoparticles are excellent anti-bacterial material and they can decompose toxic halo-organic compounds such as pesticides into non-toxic organic products. [24] 3. Distillation involves boiling the water to produce water vapour. The vapour contacts a cool surface where it condenses as a liquid. Because the solutes are not normally vaporised, they remain in the boiling solution. Even distillation does not completely purify water, because of contaminants with similar boiling points and droplets of unvapourised liquid carried with the steam. However, 99. 9% pure water can be obtained by distillation. 4. Reverse osmosis: Mechanical pressure is applied to an impure solution to force pure water through a semi-permeable membrane. Reverse osmosis is theoretically the most thorough method of large scale water purification available, although perfect semi-permeable membranes are difficult to create. Unless membranes are well-maintained, algae and other life forms can colonize the membranes. 5. The use of iron in removing arsenic from water. See Arsenic contamination of groundwater. 6. Direct Contact Membrane Distillation (DCMD). Applicable to desalination. Heated seawater is passed along the surface of a hydrophobic polymer membrane. Evaporated water passes from the hot side through pores in the membrane into a stream of cold pure water on the other side. The difference in vapour pressure between the hot and cold side helps to push water molecules through. 7. Desalination is a process by which saline water (generally sea water) is converted to fresh water. The most common desalination processes are distillation and reverse osmosis. Desalination is currently expensive compared to most alternative sources of water, and only a very small fraction of total human use is satisfied by desalination. It is only economically practical for high-valued uses (such as household and industrial uses) in arid areas. 8. Gas hydrate crystals centrifuge method. If carbon dioxide or other low molecular weight gas is mixed with contaminated water at high pressure and low temperature, gas hydrate crystals will form exothermically. Separation of the crystalline hydrate may be performed by centrifuge or sedimentation and decanting. Water can be released from the hydrate crystals by heating[25] 9. In Situ Chemical Oxidation, a form of advanced oxidation processes and advanced oxidation technology is an environmental remediation technique used for soil and/or groundwater remediation to reduce the concentrations of targeted environmental contaminants to acceptable levels. ISCO is accomplished by injecting or otherwise introducing strong chemical oxidizers directly into the contaminated medium (soil or groundwater) to destroy chemical contaminants in place. It can be used to remediate a variety of organic compounds, including some that are resistant to natural degradation 10. Water Purification with Moringa Seeds Crushed Moringa seeds clarify and purify water to suit domestic use and lower the bacterial concentration in the water making it safe for drinking. Moringa seed powder can be used as a quick and simple method for cleaning dirty river water. Studies showed that this simple method of filtering not only diminishes water pollution, but also harmful bacteria. The moringa powder joins with the solids in the water and sinks to the bottom. This treatment also removes 90-99% of bacteria contained in water. [26] Demineralized water Distillation removes all minerals from water, and the membrane methods of reverse osmosis and nanofiltration remove most to all minerals. This results in demineralized water which is not considered ideal drinking water. The World Health Organization has investigated the health effects of demineralized water since 1980. [29] Experiments in humans found that demineralized water increased diuresis and the elimination of electrolytes, with decreased blood serum potassium concentration. Magnesium, calcium, and other minerals in water can help to protect against nutritional deficiency. Demineralized water may also increase the risk from toxic metals because it more readily leaches materials from piping like lead and cadmium, which is prevented by dissolved minerals such as calcium and magnesium. Low-mineral water has been implicated in specific cases of lead poisoning in infants, when lead from pipes leached at especially high rates into the water. Recommendations for magnesium have been put at a minimum of 10 mg/L with 20–30 mg/L optimum; for calcium a 20 mg/L minimum and a 40–80 mg/L optimum, and a total water hardness (adding magnesium and calcium) of 2 to 4 mmol/L. At water hardness above 5 mmol/L, higher incidence of gallstones, kidney stones, urinary stones, arthrosis, and arthropathies have been observed. [30] Additionally, desalination processes can increase the risk of bacterial contamination. [30] Manufacturers of home water distillers claim the opposite—that minerals in water are the cause of many diseases, and that most beneficial minerals come from food, not water. [31][32] They quote the American Medical Association as saying The bodys need for minerals is largely met through foods, not drinking water. The WHO report agrees that drinking water, with some rare exceptions, is not the major source of essential elements for humans and is not the major source of our calcium and magnesium intake, yet states that demineralized water is harmful anyway. Additional evidence comes from animal experiments and clinical observations in several countries. Animals given zinc or magnesium dosed in their drinking water had a significantly higher concentration of these elements in the serum than animals given the same elements in much higher amounts with food and provided with low-mineral water to drink. The solar water purifier ‘the best invention of the year’ enables users to drink water safely from contaminated water sources. It’s ideal for home owners during emergencies such as local flooding which can contaminate drinking water supplies. It is also ideal for campers and hikers who may be drinking from rivers or lakes; it is also ideal for travelers who don’t want to rely on the quality of local water. CHAPTER 3: Methodology Apparatus -Glass window. -Containers (3). -Charcoal. -Stands. Procedure Take a container A, pour dirty water and hang two pieces of cloth at its side ith their bases in contact with the water. The container should be raised 1metre above the ground. From the container A, a pipe should be leading to another container B containing charcoal. The whole part containing the tray with charcoal should have a black coating and be covered by a glass window . Lastly place container B at the end to collect the pure water. Observations The resulting water is clear. Water droplets were observed on the glass window. DATA It has been noticed there’s a high percentage of death due to dirty water . As stated earlier on, dirty water is a key link in the cycle of water borne diseases. 97 % of water in this world is salty sea water, 0. 07% retained water and 2. 23% is usable fresh water. The small percentage of water left is contaminated daily. The 97% of withheld water can be purified through the solar water purifier to solve strategies on lack of access of clean water. Approximately 1. 8 million people die due dirty water intake CHAPTER 4 DATA ANALYSIS AND INTERPRETATION 41% of 39. 8 million Kenyans do not have access to clean water. In 2008, only 59% of all Kenyans had access to safe water. 1 The 2006 drought in Kenya was declared a national disaster, as 3. 5 million people faced starvation and food shortages. 5 Droughts continue to plague the region. Beyond the threat of drought-induced food scarcity, 10% of deaths in Kenya occur from water-borne or sanitation-related diseases. 6 DATA SHOWING KEY STATISTICS IN THE WATER SECTOR IN KENYA PERCENTAGEDESCRIPTION 41%The number of people who do not have access to clean water 59%Have access to clean water 0%The percentage of land in Kenya that is arid and semi- arid 10%Percentage of deaths in Kenya caused by water and sanitation-related diseases SOURCES Ministry of water and sanitation http://www. quietway. org/water-for-kenya/ CHAPTER 5 CONCLUSION AND RECOMMENDATION As stated earlier, the solar water purifier is healthy and efficient as the end product is pure. The materials used to construct it are locally available and it requires less human labour to construct it. Besides it is environment friendly as it does not pollute the environment in any way. It is also advisable to use it in purification of tap water as it may contain lead due to metallic pipes. We would like to recommend that the solar water purifier should be used in places such as slums, arid areas, flooding areas, by campers and tourists who do not rely on local water. This will reduce the rate of medical cases linked with water borne diseases, not to forget the rising death rates. We recommend that the government should distribute the solar water purifier to the less privileged as that will aid them. REFERENCES F. A. ABOTT , ADVANCE LEVEL PHYSICS 1999, LONDON www. wikipedia. com www. deka. org/water purification

Monday, November 25, 2019

Free Essays on Suicide Evaluation

Suicide Evaluation Suicide is a serious problem that needs to be studied so as to best determine a source of prevention for the numerous people groups that attempt suicide every year. The study of suicide can be directed through many different topics and sub-topics in an attempt to gain more insight concerning a specific faction of people. This paper will evaluate five particular topics of suicide through which a qualified study has been completed and recorded in a professional journal of medicine. These topics of suicide include a study focused on the old elderly, American adolescents, South Asian women of the United Kingdom, white and black/mixed race female prisoners of the United Kingdom, and the heightened risk of suicide in patients that gain energy while still heavily depressed. Article # 1 â€Å"Predictors of Suicide in the Old Elderly† The suicide of senior citizens as examined by Waern, Rubenowitz, and Wilhelmson (2003) states that: Seniors aged 75 and above have the highest suicide rates of all age groups in most industrial- ized countries. However, research concerning risk factors for suicide in the old elderly is sparse. The purpose was to determine predictors for suicide among the old elderly (75+). Their hypotheses is that the old elderly (75+) is at greater risk of suicide than the young elderly (65-74) due to extenuating circumstances that affect both groups but has a greater impact on the old elderly. Research was conducted in Sweden through a series of surveys and interviews with a specified sample of the Swedish population. Waern, Rubenowitz, and Wilhelmson (2003) states that: 85 consecutive cases of suicide that occurred in western Sweden and 153 control persons with the same sex, birth year, and zip code as the suicide cases were randomly selected from the tax register. The old elderly group included 38 cases and 71 controls; the young elderl... Free Essays on Suicide Evaluation Free Essays on Suicide Evaluation Suicide Evaluation Suicide is a serious problem that needs to be studied so as to best determine a source of prevention for the numerous people groups that attempt suicide every year. The study of suicide can be directed through many different topics and sub-topics in an attempt to gain more insight concerning a specific faction of people. This paper will evaluate five particular topics of suicide through which a qualified study has been completed and recorded in a professional journal of medicine. These topics of suicide include a study focused on the old elderly, American adolescents, South Asian women of the United Kingdom, white and black/mixed race female prisoners of the United Kingdom, and the heightened risk of suicide in patients that gain energy while still heavily depressed. Article # 1 â€Å"Predictors of Suicide in the Old Elderly† The suicide of senior citizens as examined by Waern, Rubenowitz, and Wilhelmson (2003) states that: Seniors aged 75 and above have the highest suicide rates of all age groups in most industrial- ized countries. However, research concerning risk factors for suicide in the old elderly is sparse. The purpose was to determine predictors for suicide among the old elderly (75+). Their hypotheses is that the old elderly (75+) is at greater risk of suicide than the young elderly (65-74) due to extenuating circumstances that affect both groups but has a greater impact on the old elderly. Research was conducted in Sweden through a series of surveys and interviews with a specified sample of the Swedish population. Waern, Rubenowitz, and Wilhelmson (2003) states that: 85 consecutive cases of suicide that occurred in western Sweden and 153 control persons with the same sex, birth year, and zip code as the suicide cases were randomly selected from the tax register. The old elderly group included 38 cases and 71 controls; the young elderl...

Thursday, November 21, 2019

3.European governments have recently passed legislation making it Essay

3.European governments have recently passed legislation making it easier for firms to introduce short-term employment contracts. Evaluate the implications for - Essay Example This old convention, symbolised by an interchange of job security for work done and faithfulness, is being replaced by a new convention wherein employers guarantee to teach workers and enable them to be employed in several firms, but give no assurance of permanent job. The use of short-term contract workers is not restricted to clerical work, but also clinches high-skill profession like engineering, research, computer programming, drafting etc. (Kalleberg; Knoke; Marsden 4) The method of employing provisional short-term contract employees is not a new or an innovative one. IT firms started this method in the mid part of the 1990s and they have been effectively employing contractors since the last decade. But in the last few years, there has been an increasing dependence on contract workers in the fields like medical writing, communications, sales and marketing of the products of pharmaceutical companies. Several huge pharmaceutical as well as biotech firms have understood that it is more lucrative to employ temporary workers on a required basis when compared with keeping costly permanent employees having significantly lesser work. (Contract Employment: A New Paradigm for Pharma and Biotech) Reducing cost has an effect on the size as well as structure of jobs. Companies are able to stimulate a switch of permanent jobs with that of short-term contracts. (Nunziata, L; Stafolani 73) In recent times, there have been labour changes across Europe. It has been argued that the small employment boom that has been witnessed of late in Europe has mainly been due to short-term employment. (Alesina; Giavazzi 9) In France, the law forming the First Employment Contract known as the Contrat Premiere Embauche or CPE was being passed by parliament with regard to an expansive bill relating to equal opportunities. According to the CPE, short-term work contract was to be provided with a 2-year testing

Wednesday, November 20, 2019

Policy Lightening Essay Example | Topics and Well Written Essays - 250 words

Policy Lightening - Essay Example The public should work together with the government to avoid recurrence (Kettl, 2014, p. 1). â€Å"Policy Lightening† was used to refer to anything that takes place when policies are blowing off by the lightening on striking occasion. There are inescapable conclusions, and they are two, this includes; a policy lightening that take place in excessive frequencies that is it keep on recurring. Another inescapable conclusion is that some changes are befalling and it make the situation worst, it causes many destructions if became more frequent (Kettl, 2014, p. 5). Many things have been happening in the government. The government has lost trust with the public. The government has repeatedly made so many mistakes; this includes; the misuse of public resources without clear explanation, like Bruno Iksil, who went to unknown with the finances, President and Chairman could not go through this failure. Ilksil lost a lot of money, which was more than 5 billion dollars. Another one was Hur ricane Katrina, which happened in 2005, the government failed to overcome the disaster though there was a forecast, and they did not prepare and mitigate the storm. Another failure that has recurred is when the private company failure of taking their responsibilities for the disaster that is when British Petroleum oil spillage and explosion in deep water. The spillage was devastating that it needed government to intervene in it.

Monday, November 18, 2019

Disscussion question Assignment Example | Topics and Well Written Essays - 500 words

Disscussion question - Assignment Example Effecting of sanctions and embargoes might do more harm than beneficial to a country for this reason; it should be done carefully after assessment of the possible aftermaths. America at one point had an embargo on almost all commodities excluding oil; this was because oil is one of their economies’ driving forces. The other strategy is through innovations which drive towards sustainable growth and quality jobs. Based on the idea that US economy is reliant on fossil fuels, it is tremendously valuable for the US government to protect consumers and businesses against harmful price shocks. Lovett, Eckes & Brinkman (2004) further explains that it has been the government’s role to assure continuous supply of strategic materials such as oil. For a long time, the U.S has left this task to the national defense stockpile which ensures that materials needed are available in time of war and this meant leaving it to the free market to guarantee supply for the industrial economy. In order to trim down US dependence on doubtful sources of supply of strategic materials need to be based on a combination of approaches (Lovett, Eckes, & Brinkman 2004). Through planned purchasing and procurement, the state ensures availability of strategic materials. When it is done by professional, it is termed as supply management. This makes sure that there is a constant supply of the strategic materials needed to the state and in a reasonable time so that there are no cases of deficit (Lovett, Eckes, & Brinkman (2004). As many would believe, US policy should be aiming at increasing trade. It is fascinating to note that, not all Americans are happy with the policy makers as the majorly dwell on business importance coupled with overwhelming goodwill that incorporate other priorities. Eckes (2000) argues that for a long time, now majority of American have been supporting the trade policy as they believe that it will improve trade. For instance, in 2001, poll

Saturday, November 16, 2019

Definition Of Industry And Porter Economics Essay

Definition Of Industry And Porter Economics Essay This chapter presents a basic explanation of how the pharmaceutical industry will be defined and which models will be used to analyse it. 2.1 Definition of Industry The most important definition of industry was given by Michael Porter in 1979: a group of competitors producing substitutes that are close enough that the behavior of any firm affects each of the others either directly or indirectly.  [1]  Later, Porter defined the term more precisely as a group of companies offering products or services that are close substitutes for each other, that is, products or services that satisfy the same basic customers needs.  [2]  This new definition emphasizes the importance of industry borders and industrys role as a market supplier or producer of goods and services, as distinguished from a market, defined as a consumer of goods and services. Furthermore, inside every industry there are groups of companies that follow similar strategies, defined by Michael S. Hunt in his unpublished 1972 Ph.D. dissertation as strategic groups.  [3]  Between these groups there are differences in entry barriers, bargaining power with buyers and suppliers and skills and resources  [4]  . Strategic groups compete against each other within the industry as a result of these differences. 2.2 Models to Analyze the Industry and Its Environment The literature agrees that comprehension of the industry structure is essential to developing a firms strategy and has a greater effect on the firms performance than whether it is business-specific or corporate-parent.  [5]  The comprehension of the structure requires analyses of the industrys life cycle. It also requires step-by-step political, legal, technological, social and economic analyses as well as the five driving forces of business, provided by Michael Porter. By utilizing these analysis techniques, it is also possible to anticipate changes in industry competition and profitability over time. 2.2.1 Industry Life Cycle Analysis During its development an industry passes through different phases, each characterized by a different environment that obliges competition to assume different forms. Through studying the life cycle, the industry realizes its stake in the market and its influence on consumers. The industry life cycle model includes four different phases: introduction, growth, maturity and decline.  [6]   The introductory phase is characterized by low demand, resulting in higher prices as a consequence of the firms inability to realize economies of scale. This situation gives rise to low profit margins and losses are expected due to substantial investments in new categories. Market penetration may be obstructed by a lack of technologies and competencies. Strategy is focused mainly on RD and production, with the goal of enhancing novelty and quality. Competitors, attracted by the rising demand, attempt to replicate the new product.  [7]   In the second phase, growth, the use of the product is extended, demand grows, prices decline due to economies of scale, barriers to entry are lower and the threat of new entry is high. At this phase the technology is usually not exclusive property of one or more firms, and the primary reaction to competition is marketing expenditure and initiatives; profits are not very high because prices decline as competitors enter the market. There is a transition period, or shakeout, between the second and the third phases. The shakeout involves finding and using all investment opportunities, because the market is near saturation and demand grows more slowly.  [8]   In the third phase, maturity, market growth is low or nonexistent, and the focus shifts to gaining market share; demand is represented only by the substitution of products, investment in RD decreases and there is little innovation. In this phase firms seek cost reductions, and competition is based primarily on advertising and quality because of the low differentiation between products. Big firms acquire smaller players, while others are forced to exit. As a conseguence of high barrier to entry, the threat of new entrants are low.  [9]   The last phase is decline, so called because of the continued decline in demand. Industries arrive at this stage for a variety of reasons. These include a change in social behaviors, demographic changes, international competition, technological innovations and increased customer knowledge. The buying process is based primarily on price rather than innovation. As a result, profit and revenues decline, and the industry as a whole may be supplanted.  [10]   2.2.2 PEST Analysis The term PEST is an acronym of several factors Political, Economic, Social and Technological that influence business activities at any given moment. Due to the fact that each aspect may have an independent impact on the industry, it is essential that each be individually identified and analyzed through the PEST Analysis.  [11]   The political aspect of analysis encompasses various factors that influence business activities in a given country at several levels: national, subnational and supranational levels.  [12]  These include trade policies control imports, exports and international business partners, government ownership of industry, attitude toward monopolies and competition and trade policies. Hence, failure to consider these policies may result in loss of revenue due to taxes or penalty fees. Government stability is also very important, because it eradicates the risks associated with wars and conflicts. For an industry to thrive, political stability must be uncompromised; otherwise, sales and business activities will be uncertain, and investors will lose interest. The internal political issues in any country influence the running of industries. Politics based on race or religion may define the course for certain industries, especially if an industry falls short of political expectations. Elections and changes in leadership also influence an industrys strengths and opportunities and thus should be considered during the analysis. In addition to internal issues, international pressures and influences may affect some industries, such as environmental degradation or product safety. Another factor is terrorism. Though uncommon in many countries, poor or unstable governance may attract terrorist activities, vengeful or otherwise, which can have adverse effects on the industries operating in that country. All these issues may stunt industrial growth and discourage stakeholders from making significant investments.  [13]   The economic aspect of analysis includes many factors. The first factor to consider is the current economic situation and trends in the country in which the industry is based. Companies should note inflation and economic decline so that when it comes to investing, they can avoid being financially affected. Failure to do this results in an economically blind platform that may cause the industrys sudden collapse. Another factor to consider in analysis is taxation rates. When there are high taxation rates in a given country, price-based competition may affect a given industry in the international market. International economic trends are also very important, because they define currency exchange rates, imports and exports. Other factors to consider are consumer expenditure and disposable income and, finally, legal issues, including all trade legislation in a given country and other legal regulations that inhibit or encourage expansion of business activities. Also to be considered are co nsumer protection laws, employment laws, environmental protection laws and quality standardization regulations. Law regulating industrial competition, market policies and guidelines also have a significant impact on the stability of industry and future expansion opportunity.  [14]   When considering the social aspect, factors including demographic changes, shifts in values and culture and changes in lifestyle are important to note so as to strategize on expansion and growth  [15]  . Certain factors, such as media and communities, influence an industrys growth and returns. Brand name and corporate image are also very important in influencing growth and returns since they shape customer loyalty and shareholder investment. The medias views on certain industrial products should be incorporated into the analysis, as should consumer attitudes and sensibility to green issues, that is, issues that affect the environment, energy consumption and waste and its disposal. A companys information systems and internal and external communications should also be analyzed to ensure that it keeps pace with its competitors. Other factors are the policies regulating education, health and distribution of income, all of which, in the long run, influence consumer use of products   [16]  . The technological aspect of analysis encompasses a variety of factors. In addition to developing technologies, all associated technologies, along with their innovation potentials, speed of change and adoption of new technology, should be analyzed for a proper evaluation of the industry. Other technological factors are transportation, waste management and online business. The level of expenditure on RD should also be considered in order to secure the industrys competitive position to prevent losses and collapse  [17]  . 2.2.3 Porters Five Competitive Forces Analysis Porters model, as described by Kay, is an evolution of the Structure-Conduct-Performance paradigm conceived by Edward Mason at Harvard University in the 1930s and detailed by Scherer in the 1980s.  [18]  ,  [19]  The model aims to determine the intensity of industry competition, major issues in determining strategy and whether an industry is attractive or not.  [20]  Porter identified five competitive forces that act on an industry and its environment: threat of entry, intensity of rivalry among existing competitors, threat of substitutes, bargaining power of buyers and bargaining power of suppliers.  [21]   The first competitive force, threat of entry, refers to the threat of new entrants in an established industry or acquisition to gain market share. Reactions of participants and barriers to entry are the main factors used to establish whether the threat is high or low. Six major entry barriers have been identified: capital required to compete in the industry (especially in risky industry, such as advertising or RD) switching costs access to distribution channels economies of scale cost disadvantages independent of scale, such as patents, access to know-how, access to limited resources, favorable locations, government subsidies or policies and learning or experience curves product differentiation expected retaliation from existing firms against the new entrants Strong barriers to the entry of new firms enable a few firms to dominate the market and thereby influence prices. The second force is intensity of rivalry among existing competitors. Rivalry takes place when one or more firms inside an industry try to improve their position using tactics such as price competition, new product introduction or new services. Rivalry depends on several factors: number and size of competitors, industry growth, product characteristics (which determine whether the rivalry is based on price or differentiation), cost structure, exit barriers, diverse competitors, operative capacity and high strategic stakes. If an industry is inhibited, then firms will experience difficulties when trying to expand. The growth of foreign competition and the corporate stakes should also be included in the analysis. Threat of substitutes is the third forces. Substitutes are those products manufactured by other industries but serving the same purposes as the initial product. These substitute products cause the demand to decline. The implications are reduced profits and reduced market command by the original capital investor. This is of particular importance when the buyer has no switching costs and can easily compare products in terms of price and efficiency. Bargaining power of buyers is the fourth force. High bargaining power positions weak firms inside the industry, forcing price down, enhancing competition between industry players and resulting in bargaining for higher quality or services. This power is particularly high under certain conditions, such as few and specific buyers, undifferentiated products, low switching costs, the possibility of backward integration and information about demand and the availability of market price to the buyers. Furthermore, bargaining power is high if product quality is not a crucial factor of decision-making and if what the buyer is acquiring is a modest fraction of his total costs. Bargaining power is even higher when the buyer is a retailer or a wholesaler able to influence the consumers purchasing decision. The fifth and last force is the bargaining power of suppliers. This can act on the industry in several ways: raising prices, lowering quality or privileging some buyers. Supplier power can be divided into several elements. One of these elements is supplier concentration. Suppliers are in a stronger position when there are few suppliers, switching costs are high, the industry they are serving account for a small fraction of their business or their products are an important part of the buyers business. The bargaining power of suppliers is low or nonexistent when there are substitute products. Lastly, purchase volume and the suppliers influence on cost are very important.

Wednesday, November 13, 2019

The Elements of a Real Athlete Essay example -- Sports Athletics Sport

The Elements of a Real Athlete   Ã‚  Ã‚  Ã‚  Ã‚  When you think of an athlete, what comes to mind? The first things that probably come to mind are sports, entertainment, and physical abilities. If these are the first things you think of, then how would athletes significant? If you look at athletes from a different perspective, their significance can be seen. From this point of view one can see that athletes are significant because they provide role models, contribute to our business world, bring countries or groups of people together, and they provide sources of inspriration. Their prominence, which is enhanced by the media, can cause them to have a greater effect in these types of roles.   Ã‚  Ã‚  Ã‚  Ã‚  Athletes are a big part of the business community. The media exposure athletes receives cause them to be perceived more as celebrities. It causes them to have a greater impact in the marketing and selling of products. For instance, the tremendous amount of media coverage that Michael Jordan received gave him a prominent role in the business world. Athletic companies and various kinds of businesses wanted him to endorse their products. Now, because of his Nike endorsement, the athletic apparel and shoe industries are a big part of the American economy. Through endorsements companies now look upon athletes to strengthen their products. In most cases, this method is usually successful. This gives an overall boost to the economy, hence fortifying athletes’ significance.   Ã‚  Ã‚  Ã‚  Ã‚  With their functi...

Monday, November 11, 2019

Social Mobility vs Structural Mobility vs Exchange Mobility

Social mobility refers to change in an individual's social class position either between their own and their parents' social class or over the course of their working career. Social mobility has taken place between my grandmother, my mother, and me. My grandmother did not finish high school and she became an apartment manager. My mom finished high school and was able to start her own cleaning business. I am currently attending college and I work for a nonprofit organization as a disability services professional.My mom experienced upward social mobility. My grandmother managed an apartment complex for most of her life. My mom was more successful than her mother. My mom finished school and went on to start and run her own cleaning business. I am currently on my way up the success ladder to experience upward social mobility. I am currently attending college for business administration. When I am finished, I hope to be a successful business woman. Within the past three generations of my family, we have not experienced any downward social mobility.My mom was able to be more successful than her mother and I plan to be more successful than my mother. Structural mobility refers to change in society that allows large numbers of people to move up or down the class ladder. Structural mobility has also taken place between my grandmother, my mother, and me. My mother moved up the social class ladder because she was more successful than her mother. Because she was more successful, she had a broader social class of friends. I also moved upward on the social class ladder.With today’s society, it is much harder to find a social class to fit in to. I have been fortunate enough to have a numerous variety of friends from different social classes because I attend college, and because of my work profession. Exchange mobility occurs when large numbers of people move up and down the social class ladder, but, on balance, the proportions of the social classes remain about the sam e. Right now, I do not think that my family is experiencing exchange mobility.It seems that our social classes are not balancing out. Since my mother moved up the ladder and I am also moving up the ladder; that means my families current social class’s ratio is 2:1. If I have a daughter later on in life, she will become the fourth generation of my family. If my daughter was unable to be as successful as I am, that would mean that she would move down the social class ladder. This would make our family experience exchange mobility because our social class’s ratio would then be 2:2.

Saturday, November 9, 2019

6 Things to Know When Picking a Family Reunion Location

6 Things to Know When Picking a Family Reunion Location The ideal family reunion site is one which is accessible and affordable for the majority of the people you want to attend. Its a place where everyone can be comfortable and enjoy their time together. When choosing a location for your family reunion, there are some important things to consider. Distance Will the family reunion be just one day, an entire weekend, or a full week? If youre planning a short reunion, most people probably wont be as willing to travel long distances to attend. Select a location close to a majority of family members - possibly a neighborhood park, a family members home, or a local hotel or restaurant. Longer gatherings, especially special one-time reunions, may warrant a more elaborate location such as a cruise, dude ranch, or family resort. Convenience How far will guests have to travel to get to your reunion location? If a number of them will have to travel by air, consider holding your family reunion in an area convenient to a major airport. A location thats accessible and easy to find means that more people will likely attend. Accessibility Do you have people with limited mobility attending your reunion? Elderly relatives in wheelchairs or young children in strollers? Make sure that the location you choose will comfortably accommodate everyone who will attend. Children need safe, supervised areas in which to play, and seniors will welcome comfortable seating and nearby restrooms. Affordability Cost - including rental fees, food, and parking fees - is a significant factor for most family reunions. Make sure that the location you choose fits into your budget, as well as that of your relatives. Many facilities offer group discounts and package deals for family reunions. Accommodations If your reunion is held in a setting that doesnt include overnight accommodations, make sure that a sufficient number of affordable rooms in local homes and hotels are available nearby. Features and Activities What attractions and activities does the reunion site and nearby area provide? Recreational activities such as boating, swimming, golf, and camping can be fun when incorporated into a family reunion. People attending from outside the area may enjoy a location with nearby museums, historic sites, amusement parks, sports facilities, and other attractions. Find a location that makes your reunion less of a meeting and more of a destination. When choosing your location, be sure to ask about facilities such as parking, restrooms and, for outdoor reunions, alternatives in case of rain. To help with the legwork, dont be afraid to make use of local travel bureaus and chambers of commerce. Since they like to bring people to their area, they are usually more than happy to help you with location ideas, lodging and dining listings, and recreation and sightseeing opportunities.

Wednesday, November 6, 2019

How to Improve the People Contribution to Project Management

How to Improve the People Contribution to Project Management Abstract In the modern day business environment, organizations are constantly forced to exhibit innovation and enhanced performance so as to remain relevant and profitable in an ever increasingly competitive arena. The input of both the individuals and groups in the organization is invaluable to the achievement of organizational goals.Advertising We will write a custom report sample on How to Improve the People Contribution to Project Management specifically for you for only $16.05 $11/page Learn More This research paper sets out to explore various dimensions that contribute towards effective and efficient group processes in an organizational setting. This shall be achieved by going into a detailed discussion as to what effective group processes consists of. To this end, an analysis on what group process refers to shall be offered and its relevance to leadership and organizational development addressed. How these processes affect the levels of commitment and performance exhibited by individuals working in groups shall also be outlined. In addition, a discussion regarding the various issues that may affect group processes shall also be presented. Introduction In the past few decades, the importance of project governance in various sectors has gained prominence. This has mainly been due to the fact that we have been moving into an era where businesses employ most of their resources into various projects which are aimed at increasing productivity, enhance competition and improve quality of goods and services offered. As such, project management mechanisms have been developed to ensure that any proposed project completes its course with little to no complications. Project governance and management often refers to the rules and regulations instituted by an organization to ensure that a project achieves its purpose (Kerzner, 2006). However, in the recent past, there have been many documented reports which indicate that most projects started off by organizations end up failing or fulfilling the expected purpose. Methodology According to McGuire and Ikpa (2008), the most suitable tool to use while evaluating situations is analyzing the correlations that exist between the aspects presented. As such, the study shall use the descriptive correlation research method.Advertising Looking for report on project management? Let's see if we can help you! Get your first paper with 15% OFF Learn More This is because it seeks to identify the relationship between two variables which in this case are group dynamics and project success or failure in various organizations. Data used to compile this report shall include peer reviewed articles related to this topic as well as books used in class and other online sources. Group process To have a better understanding of the term ‘Group process’, it would be a worthwhile endeavor to shed some light on what each word means. As regarding to human resource in an organizational setting, a group can simply be defined as a given number of people who carryout various organizational tasks together in a bid to achieve predetermined goals and objectives (Brown Harvey, 2006). A process on the other hand refers to a course of action characterized by a series of stages that is implemented to facilitate the achievement of particular goals and objectives. With these concepts and definitions in mind, we can therefore proceed to defining the term Group process as used in organizational development. Webne-Behrman (2008) defines group process as the procedures implemented by member of an organization who are closely working together in a bid to come up with the best solutions to handle or solve a common problem. Impact of group processes to organizations Leadership refers to a process through which one person uses the help and support of others towards achieving a particular goal or task. Strong leadership is not only desirable but also essential to th e success of the business for it is through it that organizational goals are met. As mentioned earlier, understanding group process enables leaders to support groups as they work towards achieving organizational goals. As Brown (2000) asserts, an expert in group process can be able to evaluate a group’s ability to work as a problem solving and decision-making entity, all the while designing measures to counter undesirable behavioral traits that seem to inhibit the group’s ability to perform as required. Greene Burleson (2003) further contend that the success of any organization depends mainly on the effectiveness and ability of the leader to inspire. Studies have it that the stock prices of well led companies increased by over 900% in a 10 year period as opposed to a bare 74% growth recorded by those companies that lacked good leadership.Advertising We will write a custom report sample on How to Improve the People Contribution to Project Management specificall y for you for only $16.05 $11/page Learn More This fact effectively underscores the importance of understanding group dynamics because a leader is deemed worthless if he lacks the backing and support of a team/group. It is therefore important that all leaders work towards cultivating and generating an intellectual capital for their firms. By understanding group process, a leader is better placed to motivate group members towards working together as a team. This duly gives an organization a competitive advantage over other competitors in the market. In most organization, only a fraction of the capability of the work force is utilized because leaders do not fully understand how best to motivate employees. Huszczo (2004) acknowledges that managers cannot gain much by coercing the employees to work harder. Instead, an increase in productivity can be achieved if the leaders invest highly on retraining programs, ensure availability of essential resources, and provide mot ivational attributes like bonuses, promotions and even pay increments to act as incentives. Such interventions can only be discovered if leaders understand how groups behave and react to certain positive or negative stimuli. An exemplary leader should ensure that his organization has a sense of purpose and is working towards the achievement of some organizational goals. He/she should also set out to generate and sustain trust between the administration, employees and clients. Malhotra (2000) asserts that this will result in the promotion of hope and confidence amongst the organizations worker force. These qualities heighten the levels of optimism within the organization all the while boosting employee’s morale and guarantees future success in all organizational endeavors (Porter Lilly, 1993). However, if a leader does not understand the needs and behaviors of different members of a group, there is a high likelihood that the leader’s efforts to reassure employees will fail because employees tend to follow leaders who understand them and their work needs.Advertising Looking for report on project management? Let's see if we can help you! Get your first paper with 15% OFF Learn More Project management: A brief overview The Standish group (1995) report has for a long time been noted as the landmark report on IT project failures. The report displayed results gathered from executive managers who had invested in various IT projects across different sectors. The results indicated that: â€Å"31.1% of projects will be canceled before they ever get completed. Further results indicate 52.7% of projects will cost over 189% of their original estimates (Standish Group, 1995)†. In regards to success rates, the report indicated that; â€Å"only 16.2% for software projects that are completed on-time and on-budget (Standish Group, 1995)†. Ever since the report was presented, the number of failed IT projects across different sectors has been increasing at an alarming rate. Case study: Queensland Health Government of Queensland Australia Queensland Health is an organization dedicated to the provision of healthcare services to the Australian community. In a bid t o improve its efficiency, accuracy and cost reduction in service delivery, the organization thought it wise to modernize its payroll system (ERP). As such, the project which cost the organization $64.5 Australian dollars was expected to end by June 2010. However, the project which aimed at replacing the aging payroll system that had been in use ended up as a major failure for the organization. This failure not only had serious financial repercussions to the organization, but also left thousands of employees with little to no pay due to major cut-over. Even though, the organization is yet to provide a conclusive report accounting for this failure, the press and business analysts highlighted the major mistakes that were made during the project. Contributing factors as reported by analysts and the press Key contributing factors as documented in various literatures included but were not limited to: poor project planning, lack of clear roles and responsibilities for project team members, poor communication skills and training. In addition, the stakeholders were not engaged effectively in the project and there was evidence of tension between government departments. On the same note, the project managers failed to resolve the complex business processes before implementing the new system. Finally, reports indicate that the project requirements and alignment did not meet the needs of the business. In summary, the project failed due to poor planning, communication, managerial and, risk management skills. The same factors have been documented as being among the core factors that lead to project failures in most businesses. Evaluating group success or failure: A literature review According to Ledingham and Bruning (2000), good communication is considered to be one of the fundamental building blocks of a successful organization. If efficient communication is to take place, there must be some levels of trust exuded and mutual respect by parties involved in any given project . Ledingham and Bruning (2000) advance that interaction with each other leads to greater appreciation and hence building of mutual respect and eventually establishment of trust. Considering the adversarial communication currently exhibited in the organization, team building exercises e.g. sporting activities, interdepartmental parties and other social events would have averted the communication hurdles that led to the project failure. Communication issues are complex and dynamic and therefore no one way can be proposed as solving all the problems involving communication in an organizational context. In order to ensure that communication is effective, it is important to consider the relevant channel of communication as settling for the correct channel ensures the message is relayed in the most appropriate manner. Having communication skills within a group ensures that group members evaluate how they communicate in order to avoid conflicts (Pinto, Pinto Prescott, 1993). As such, it w ould also be vital to develop a relevant message and this ensures that the correct information is passed on. This entails understanding the audience and once accomplished it will then be easier to appropriately develop message (Adair, 2009). Setting objectives that one hopes to achieve through the message can also help ensure the message is not only effective but well understood. In addition, Hashmi (2010) reiterates that project failures are in most cases as a result of poor planning, managerial skills and conflicts. As such, the author proposes that an exemplary project manager should ensure that his team has a sense of purpose and is working towards the achievement of some organizational goals. He/she should also set out to generate and sustain trust between the administration, employees, stakeholders and clients. This results in the promotion of hope and confidence amongst the organizations worker force. These qualities heighten the levels of optimism within the organization all the while boosting employee’s morale and guarantees future success in all organizational endeavors (Hashmi, 2010). Shenhar et al (2002) embark on a sensitive topic regarding business success. The authors state that we live in a world whereby projects play a pivotal role in ensuring that organizations remain relevant in a highly competitive business environment. In their article which evaluates the meaning of project success, the authors reveal the fact that most people term a project as successful when it is completed on time and within the budgetary allocation. However, the authors disagree with this clichà © stating that while this may seem true, there are other factors that need to be considered whenever an evaluation of a project’s success is to be undertaken. In their argument, Shenhar et al (2002) state that in some cases, projects that experienced financial overruns and delays often end up being successful business ventures. As an example, they refer to Micros oft Company which experienced a lot of difficulties as they tried to come up with their first operating system. Even though the project had major delays and resource overruns, it is now used by close to 90% of all operational PCs in the world. This and many other examples shows that project success in most cases is not analyzed as required. In contrast, projects can be completed on time and within the budget but fail to cater for the organizational needs. Nogeste and Walker (2005) suggest that having and sharing a vision has proven to be among the most effective ways of ensuring project success. A vision can be loosely defined as the detailed mental image of things to come. Possessing a vision is paramount for any organization since it gives a sense of purpose and meaning to the organization members (Palmer 2008). As such, it is imperative that in any setting there be a leader who comes up with a future plan and then steer his followers towards its achievement. Visions are often for mulated by an individual or a group of people towards a specific purpose. As such, the visions may be highly personalized and may not necessarily conform to the desires of the majority. As a leader, it is important to communicate such visions to the followers and convince them as to the need to embark on the proposals since it is the followers who will determine the success of the vision (Christenson and Walker 2004). This will act as a source of motivation and morale in their day to day activities. According to Nogeste and Walker (2005), sharing a vision of the future reassures the followers of better days ahead. In addition to this, it provides meaning and a sense of belong to the followers and other stakeholders as they deem themselves as part of something greater. A shared vision inspires and motivates them to aim higher and employ extra effort so as to actualize the vision and make a significant difference in their own capacities (Schneider et al, 2008). This in turn acts as a unifying factor and creates a sense of community between them. In addition to this, Turner (2009) contends that communication of visions provides the followers with a theme of change or transformation. From the definition of project management, it is evident that there are some contributing factors that if well defined may drive a project to success. However, Munns and Bjeirmi (1996) assert that there are some factors that may lead to a project failure. They include but are not limited to, inadequate directions on how the project should be managed, unskilled personnel within the project’s team, lack of commitment or support from team members and top management and poor project planning. These factors suggest that if successful project management is to be achieved, there must be a competent project manager, clearly defined goals and objectives, adequate resources and commitment from all parties involved (Mason Harvey, 2006). Fong (2003), states that for project management to be successful, there are various techniques and tools that should be used to facilitate this. For example, he suggests that all projects should have work schedules, execution plans and effective communication channels. These factors enable the project team to avoid under-costing, overspending and delays. These are the most renowned causes of project failures. In addition, Gido Clements, 2009) reiterate that the success of a project is hinged on the belief that individuals involved in the project will execute their responsibilities accordingly. As such, project management entails defining the roles and responsibilities of each party involved in project activities. Failure to do so may lead to a situation where decisions are made slowly and there are many conflicts during the execution of the project. Conclusion From the discussion presented herein, it is evident that establishing a strong interpersonal bond amongst members of a group is of great importance if an organization is to re main successful. In this report, a definition and description of group process has been provided. Similarly, issues such as discrimination, conflict and miscommunication have been cited as being among the most prevalent factors that can influence the effectiveness of a group. In addition, the impact of group process on individual’s performance and commitment levels has also been discussed. Arguably, understanding group process gives leaders a chance to avert most of the common shortcomings that lead to organizational failures. As such, business leaders should ensure that they take time to understand various group dynamics because the future of their businesses may rely on such knowledge and understanding. References Adair, J. 2009, Effective Communication: The Most Important Management Skill of All, Pan Macmillan, New York. Brown, D. Harvey, D. 2006, An experiential approach to organizational development, 7th edn, Pearson Education. Brown, R. 2000, Group processes: dynamics within and between groups, Wiley-Blackwell, New Jersey. Christenson, D. Walker, D. 2004, ‘Understanding the Role of Vision in Project Success’, Project Management Journal, vol. 35, no. 3, pp. 39-52. Fong PSW 2003, ‘Knowledge Creation in Multidisciplinary Project Teams: an empirical study of the processes and their dynamic interrelationships’, International Journal of Project Management vol. 21 no. 7 pp. 479-486. Gido J. Clements J. D. 2009, Successful Project Management, 4th edn, South Western Cengage Learning, California. Greene, O. Burleson, R. 2003, Handbook of Communication and Social Interaction Skills, Routledge, New York. Hashmi, M. 2010, Identification of the Root Causes of Software Project Failure, Lap Lambert Academic Publishing, USA. Huszczo, G. 2004, Tools for Team Leadership: Delivering the X-factor in Team Excellence, Davies-Black Publishing, USA. Kerzner, H. 2006, Project management: a systems approach to planning, scheduling and controlli ng, 9th edn, John Wiley and Sons, New Jersey. Malhotra, Y. 2000, ‘Knowledge Management New Organization Forms: A Framework for Business Model Innovation’, Information Resources Management Journal, vol. 13, no. 1, pp. 5-14. McGuire, C. K. Ikpa, V. W. 2008, Policy, leadership, and student achievement: implications for urban communities: Achievement gap, research, practice, and policy, IAP, USA. Mason O. H. D Harvey, D. 2006, An experiential approach to organizational development, 7th edn, Pearson Education, New Jersey. Munns, A. K. Bjeirmi, B. F. 1996, ‘The Role of Project Management in Achieving Project Success’, International Journal of Project Management, vol. 14, no. 2, pp. 81-87. Nogeste, K. Walker, D. 2005 ‘Project Outcomes and Outputs: Making the Intangible Tangible’, Measuring Business Excellence, Emerald, UK, vol. 9, no. 4, pp. 55-68. Palmer, E. 2008, Ultimate leadership: winning execution strategies for your situation, Wharton Scho ol Publishing, USA. Pinto M. B., Pinto J. K. Prescott J. E. 1993, ‘Antecedents and Consequence of Project Team Cross-functional Cooperation’, Management Science, vol. 39 no. 10 pp. 1281. Porter T. W. Lilly B. S. 1993, ‘The Effects of Conflict, Trust and Task Commitment on Project Team Performance’, International Journal of Conflict Management vol. 7 no. 4 pp. 361-376. Shenhar, A. J., Dvir, D., Levy, O. Maltz, A. C. 2001, ‘Project Success: A Multidimensional Strategic Concept’, Long Range Planning, vol. 34, pp. 699 – 725. Schneider, M. et al 2008, Groups: process and practice, Cengage Learning, New York. Standish Group 1995, Chaos (Application Project Failure and Success). Web. Turner, J. R. 2009, The Handbook of Project-Based Management: Leading Strategic Change in Organizations, 3rd edn, McGraw-Hill, New York. Webne-Behrman, H. 2008, The Practice of Facilitation: Managing Group Process and Solving Problems, IAP, USA.

Monday, November 4, 2019

CONCEPTUAL ANALYSIS Assignment Example | Topics and Well Written Essays - 500 words

CONCEPTUAL ANALYSIS - Assignment Example There is a great deal of conceptual knowledge to be removed from an application even though it seems to be too obvious to figure out. In light of this, the meaning triangle must be used to extract abstract conceptual knowledge by creating distinctions between conceptual, external and verbal entities. Whereas words (lexical objects) refer to the concrete linguistic entities employed in written text or speech (word node), the concepts represent the tools used to help in the thinking process. Therefore, the concept node represents the constructs utilized in building mental images of the world. Lastly, the referent node represents the physical entities or objects that are viewed as being part and parcel of the outside/external world. Thus, apart from being used to aid in the building of better knowledge based entities now, the meaning triangle will be vital in charting out a way for computer based knowledge acquisition. Conceptual analysis is vital in various aspects according to Sowa (1984). Therefore, conceptual analysis has made it possible to retrieve arguments and ideas from text. Further, it has demonstrated that individuals should look further beyond keyword indexes so as to encourage and develop their own ideas while in the process of looking for information. Also, it is vital to note that conceptual analysis has bridged and narrowed the gap between artificial intelligence audiences and IR audiences. Further, conceptual analysis was not binded by any single rigid syntactic formula or linguistic theory. As a result, conceptual analysis has been used to explain and express concepts such as cybernetics. Although the early definition of cybernetics was broad and included artificial intelligence, the rapid development of the field brought out the differences between cybernetics and artificial intelligence. However, conceptual analysis has attempted to bridge and lower this gap. Additionally, conceptual

Saturday, November 2, 2019

The Potential Causes of Female Violence Essay Example | Topics and Well Written Essays - 500 words

The Potential Causes of Female Violence - Essay Example However, one can see that ‘Women are more likely to commit crimes now than in the past, although women who commit crimes are more likely to be arrested for nonviolent property crimes compared to male criminals whose crimes are more likely to involve violence’ (The White House). But an overview of some of the female offenders in America proves that there were women who engaged in violent crimes like men. One of such examples can be cited with Aileen Wuornos, a very notorious female serial killer and prostitute who took the life of seven men in Florida from 1989 to 1990 (Criminal Justice Degrees Guide, 2013). The way she committed the crimes are more aggressive than the male offenders and she won in her attempts to escape from trial till she commits the seventh murder. Analyzing the social factors that contributed her criminal behavior, one can see that Wuornos had a rocky upbringing that led her into prostitution at a young age. The improper guidance she received from the tender age itself had channelized her into criminal activities such as disorderly conduct, assault, armed robbery and theft. Considering the psychological reasons for her criminal behavior, it is evident that her social background is the main culprit. She committed all these crimes to make money in order to help support Tyria Moore, a hotel maid, to whom she had established an intimate relationship (Criminal Justice Degrees Guide, 2013). When Wuornos felt that her prostitution earnings are insufficient to help the maid she turned to criminal activities by robbing her customers and shooting them. Regarding the biological factors, one is sure that naturally a woman cannot overpower a man physically. Therefore, Wuornos engaged in sexual contact with her customers and after making them physically weak, she shot them to death. Among violent female offenders, 53% committed the offense while alone, and 40% were with others, all of whom were female (Greenfeld, L.A., Snell, T. L., 1999). The