Advantages of Reverse Logistics

Reverse logistics describes the process by which a business may get items back from a customer. For instance, if a product is defective, reverse logistics are used to figure out how the customer can deliver the product back to the manufacturer. Reverse logistics are used by automotive, electronic and computer businesses, among others.

Reclaimed Value
With reverse logistics, companies are able to retrieve faulty products and refurbish them. Therefore, raw materials are not wasted and thrown away, and the cost of manufacturing can decrease. Even if the collected product is unusable, it can be recycled by the company itself. This will give the scrap value back to the company, but also ensure these parts are properly recycled. This adds to the environmental impact of a business.

Satisfaction
Customer satisfaction is very important for businesses. When a customer knows he can return a product to the company in exchange for a new one, he will be more confident in that company. Therefore, by maintaining proper reverse logistics, a company can increase customer satisfaction while keeping costs down. If a company is transparent about processing, it can increase satisfaction even more, as a customer will know exactly what is required to return a product.

Customer Cost
With reverse logistics, a company can save money, but the customer will save money in the end, as well. Refurbished or repaired products are often sold at lower costs than new products, even though they are in perfect working order. This is especially true in the computer industry, where refurbished products and spare parts are increasing in popularity. Many computer companies have accommodated this need by providing more refurbished products.

Control
Reverse logistics can complete the loop in the cycle of a product, ensuring that a company has complete control over their product. Without reverse logistics, a company is unsure of what might happen to their product after it is sold. With proper reverse logistics, a business retains control over what happens to their product. This can include even having a customer return a product when it no longer functions, such as with printer ink, so it can be recycled properly.

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Latitude & Altitude & Temperature

Latitude refers to the distance of a location of a place on the earth surface from the equator; while altitude describes how high a place is located above the sea level. Latitude and altitude are two primary factors known to affect variations in temperature on the earth surface because of unequal heating of the earth's atmosphere.

Variation in Altitude
For every 100-meter rise in altitude, temperature decreases by about 1 degree Celsius. Regions in high altitudes, such as mountainous places, experience low temperatures. The earth's surface absorbs heat energy from the sun and when it warms up, the heat diffuses into the atmosphere, warms it and in turn transfers some of the heat to the upper layers of the atmosphere. Therefore the layers of atmosphere closest to the earth's surface receive the most heat compared to the high-altitude areas.

Temperature Inversion
Although typically higher altitudes experience low temperatures, this may not always be true. At times, temperature decreases with altitude (what is referred to as lapse rate) in some layers of the atmosphere (such as the troposphere). This occurs during cold winter nights when the sky is clear and the air is dry so the heat from the earth's surface radiates and cools faster than atmospheric air. It then warms the low-lying atmospheric air that rises rapidly into the sky. Consequently, places located in high altitudes, such as mountainous regions, get to experience high temperatures. Usually, the average lapse rate in the troposphere is 2 degrees Celsius per 1,000 feet.

Angle of Incidence
Angle of incidence on the earth's surface depends on the region's latitude (distance from the equator). It refers to the angle at which the sun's rays strike the earth's surface so that when the sun is positioned directly above the earth's surface at 90 degrees, the solar radiations strike the surface of the earth at right angles, making these regions experience high temperatures. However, if the sun is 45 degrees above the horizon, the solar radiations strike the earth's surface at an angle that spreads out rays over a larger surface area with less intensity, making these regions experience lower temperatures. Such regions are located further from the equator, therefore the further you go from the equator, the cooler it becomes. In essence, regions at the equator experience higher temperatures than those in the North and South poles.

Diurnal Variation
Diurnal variation is the change in temperature from day to night and often depends on latitude and the earth's rotation on its axis. Normally, the earth receives heat during the day by solar radiation and loses heat through terrestrial radiation at night. During the day the sun's radiation heats the earth's surface, but the intensity would depend on the length of the day, as some days are shorter than others. Regions with longer days will experience more intense heat. In this case, during polar winter when the sun is below the horizon for 24 hours, no solar radiation is felt and these regions remain cold. Solar radiation intensity on the earth's surface would hence depend on the latitude, the sun's altitude and the time of the year (season), ranging from no solar radiation during polar winter to maximum solar radiation of about 400 watts per square meters during summer.

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How Computers Pollute Environment

In the 21st century computers are an fundamental part of daily life. At home, at work and on the go, computers are quickly evolving. The rate of change and advancement will make this year's technology obsolete by this time next year. Computers have many positive effects on lives, however, they also place a large strain on the environment.

Electrical Strain
At the time of publication, approximately 1.3 billion people worldwide own personal computers. In the United States, roughly 164 million people own computers. Computers used for business and personal use put an enormous strain on the electrical grid. The average PC uses 746 kilowatts of power each year, requiring more power than a refrigerator, which uses only 500 kilowatts. Computers add to the strain on power plants to produce enough energy to power the world. The production of energy creates pollution and emissions. The amount of electricity needed to power computers contributes to the millions of tons of greenhouse gases that are emitted into the atmosphere each year.

Energy Waste
Computers also contribute to energy waste. Waste creates needless pollution that could be saved each year if businesses and households would shut down their computers and power off their monitors when they are not using them. U.S. businesses waste approximately 1 billion dollars each year in electricity used to power computers and monitors left on after hours. Putting your computer on stand-by or letting your monitor go into sleep mode also creates energy waste, as these modes still require power. Even leaving your computer plugged in while it is shut down will draw a small amount of power from your electrical outlet. This energy waste translates into greenhouse excess gases that contribute to pollution and global climate change.

Production
The production of computers creates pollution. The manufacturing of computers requires a large amount of fossil fuels and chemicals. Despite the fact that computers continue to decrease in size, computers still require 10 times their weight in chemicals and pollutants during manufacturing. The pollution created by computer production is harmful to the health of those living in close proximity to manufacturing facilities which expel harmful chemicals and pollutants into the air.

Landfill Waste
Changing technology and computer breakdowns lead to millions of tons of waste in discarded computers each year. An estimated 50 million tons of electronic waste are discarded each year. Most of these discarded computers are sent to landfills overseas in Africa, China, India, Vietnam and the Philippines. There are entire regions in these countries that are polluted due to computer waste. Computers contain heavy metals like lead and toxic chemicals that pollute the soil and contaminate groundwater when they are dumped into landfills. Runoff from these landfills can contaminate water used for drinking and bathing, exposing people to dangerous chemicals.

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Industry Versus General Environments

Industry and general environments are terms economists use to describe conditions of a specific financial sector or broad external conditions that can affect organizations. For example, florists and car manufacturers have other concerns as far as raw materials, production process and distribution are concerned, but they are both concerned about customers' purchasing power and taxation. Therefore, the difference between industry and general environments lies in scale and universality.

Industry Environment Defined
An industry's environment describes all conditions that can affect a business within the strict boundaries of a financial sector. It encompasses "Porter's Five Forces," such as rivalry between the industry's firms, the threat of new entrants, the threat of substitute products, the bargaining power of customers and the bargaining power of suppliers. These forces determine the industry's degree of competitiveness and price pressure.

Differences Between Industry Environments
Industry environments may have huge differences between them, as serious topics of one sector can be non-existent for another. Gas providers don't have to care about the bargaining power of customers for example, as without an alternative, people must buy gasoline for their transportation and gas heat, no matter what the cost. On the other hand, food producers must provide competitive prices, as with an abundance of substitutes, consumers can go for other products when, for example, the price of tomatoes rises dramatically.

General Environment Described
The general environment refers to external conditions that may affect an organization and go beyond the boundaries of a single industry. It describes how society can affect a business or industry in general. These can be government regulations on trade practices, employment and taxation or even the economic climate: whether consumers have the purchasing power and willingness to buy products and services.

Examples of External Conditions
The general environment can be beneficiary or harmful for different types of organizations. Industries based on unskilled manual labor have little room for profit in societies with a relatively high minimum wage. On the other hand, in such societies, businesses can try their luck on advanced, but expensive, products and services, such as information technology and pharmaceuticals. Furthermore, low tax rates can give a boost to budding entrepreneurs, while high educational standards guarantee an ever-existing skilled workforce.

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What Is Forecast Statement

A forecast statement involves writing a brief preview of the basic ideas or information that you wish to convey to readers in your writing. It gives your readers a brief outline of what they should expect in your piece of work (paper). It is an effective way of informing your readers in advance of what to expect, particularly concerning how you have organized ideas in your writing.

Uses of Forecast Statement
The writing of a forecast statement is a building block of good writing in various fields. It can be used in essays where it serves as a broad view of the topic, the purpose of the paper and boundaries of the paper. In scientific writing, it can be used to give an outline of the investigative approach to a problem since they can be used to list a series of steps used during the investigation process. Also, you can use a forecast statement in writing a résumé. Forecast statements, also known as career objectives in résumé writing, underscore the job you are seeking as well as how you would benefit your potential employer if he hires you. Additionally, in your cover letter you may as well use a forecast statement to provide additional information regarding your skills and competences. Also the forecast statement is the last thing in your introduction of the thesis statement.

Benefits
Forecasting statements help in providing your audience or readers with organizational information since it offers them a preview of what lies ahead in the main body of your paper as well as how the contents are organized. Consequently, forecast statements help readers to predict what to expect, which encourages readers to go ahead and read the entire writing. Also, its simple and straightforward nature gives readers the appeal of simplicity, which is a great point in helping the readers to understand the basis of your paper.

Deciding on Details to Include
When deciding on the details to include in the forecast statement, it is imperative to provide some specific ideas as to what you intend to discuss and the likely arrangement of your points in your paper. Additionally, you should not provide more details than your audience has the capacity to remember since forecasting statements are aimed at helping them to understand what to anticipate but not to test their memory. Lastly, you should not forecast more than one level at a time since it may burden the reader with confusing details. In that case, include only the major divisions of a particular section and in case those divisions are themselves divided, then each of them can have individual forecasting statements.

Procedure of Writing Forecast Statement
First, begin with the most important information and think about the emotional response that the writing will evoke. Start from the most general information as you move to more specific or supporting facts. Put the most important points or details in a list form rather than paragraphs for easy reading. Edit the forecast statement to ensure there are no grammatical mistakes. The forecast statement should be brief, clear and concise.

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Environmental Pros of Feedlots

A feedlot is an animal feeding operation used in factory farming to prepare livestock for slaughter. Feedlots provide all conventionally raised beef and most organic and naturally raised beef. They appeared in the 1960s and 1970s. Large feedlots are concentrated animal feeding operations (CAFOs). Almost 30 percent have more than 1,000 penned cattle per feedlot; some contain up to 100,000. The environmental impact of such large-scale ranching is great.

Feedlot Advantages
Feedlot-produced meat satisfies U.S. consumer demand, which the U.S. Department of Agriculture (USDA) reports averages 60 lb. of beef yearly. While all cattle start out eating grass, 75 percent mature in feedlots, fed specially formulated, grain-based feed. Once cattle weigh roughly 650 lb., the cattle are sent to a feedlot to consume a diet of corn byproducts and other grains. The animal may gain 400 lb. during its final few months. USDA Prime, the highest grade, has more marbling and flavor, is more tender and can be produced inexpensively in feedlots. According to the U.N. Food and Agriculture Organization, 60 percent of the world's pastures are covered by grazing systems that supply only 9 percent of the world's beef production. Feedlots are far more efficient.

Environmental Risks
The Union of Concerned Scientists estimates that approximately 70 percent of antibiotic use in the U.S. is for animals on factory farms. The antibiotics prevent infection in closely confined animals and spur their growth, but pose risks to humans in the form of resistant strains of bacteria. Alternatives to antibiotics include expanded sanitation and testing procedures. Feedlot cattle may be covered in fecal matter and bacteria. However, a Kansas State University study found no differences in organic, naturally raised beef and feedlot raised beef in terms of E. coli. Also, after the animal is slaughtered, the meat is cleaned with chlorine; for hamburger, dry ice is mixed in.

Government Regulation
Most feedlots require government permitting and plans to deal with the waste generated. Manure contains nitrogen and phosphorus; if not managed properly, they can pollute nearby water bodies. Citizen groups have raised concerns about water quality to regulatory agencies such as the Environmental Protection Agency (EPA). In 2003, the EPA revised permitting requirements and effluent limitations for CAFOs, estimating that these regulations would prevent 56 million lb. of phosphorus and 110 million lb. of nitrogen from entering water bodies each year. The EPA requires CAFOs to have a National Pollution Discharge Elimination System permit and a Nutrient Management Plan.

Risk Mitigation
Low-cost steps can be taken to preserve the benefits of industrialized livestock production while limiting its harms. These include reformulating feed, designing sloped feed stalls, monitoring microbes and using manure to create energy. Countries such as Canada and Australia have innovated their feedlot systems. A U.S. Economic Research Service executive has said the growth and consolidation of the cattle industry have actually benefited sustainability because large operators can address manure volume and other environmental hazards.

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Water Cycle Important to Ecosystem

Water is a necessity for life. Living organisms comprise at least 70 percent of water. It is the only substance present on Earth and in the atmosphere in its three phases -- solid, liquid and gaseous -- at the same time. The water, or hydrological, cycle is the circulation of water as ice, liquid water and water vapor throughout the Earth and its atmosphere. Ecosystems are biological, or biotic, communities and the chemical and physical, or abiotic, processes that influence their structure. Ecosystem boundaries range from a coastline to a pond, a field to a forest, or different depths of water in the oceans.

Clouds
The cycle starts as water evaporates from the surface of the ocean. Water vapor rises, cools and condenses into water droplets and ice particles that move over the Earth's surface. Clouds play a pivotal role in controlling the Earth's climate. They reflect incoming solar radiation back into space and exert a cooling effect on the Earth's surface. Clouds also trap outgoing radiation from the Earth and produce a warming effect on the Earth's surface.

Precipitation
Water falls back to the Earth as rain, hail or snow in the next stage of the cycle. On the ground, prevailing heat on the surface causes some of the water to evaporate again. Another part of the water penetrates surface soil and collects underground as groundwater that seeps into river systems and oceans, and emerges at the surface again as a spring. Remaining water, or runoff, flows into rivers, lakes and oceans where the cycle begins again.

Vegetation
Vegetation on the Earth's surface absorbs groundwater and nutrients through roots and evaporates it back into the atmosphere from its leaves. This is the process of transpiration that forms a further branch of the cycle. According to the U.S. Geological Survey, a large oak tree transpires 40,000 gallons of water per year, while a 1-acre corn field produces 3,000 to 4,000 gallons of water daily. This enables the vegetation to humidify the air and keep the water cycle moving in regions far away from oceans. Clearing away trees across large areas slows down rain, leading to drought and desert formation.

Oceans
Oceans are the main liquid stage of the water cycle. They cover 70 percent of the Earth's surface, hold 96.5 percent of the world's water and are responsible for the creation of 85 percent of water vapor in the atmosphere. Oceans hold the world's largest ecosystems. These communities vary according to the depth of water, its temperature, salinity and availability of sunlight. Evaporation of pure water from the surface of the ocean leaves behind salts, which become concentrated in the water. Coral reefs grow in shallow warm waters while microorganisms and bottom feeders -- flatfish and stingrays -- live in the dark, cold and deep waters.

Icecaps
Icecaps and glaciers are the solid stage of the water cycle and store 68.7 percent of the world's fresh water. The Geological Survey estimates that if all the ice melted, sea levels would rise by 230 feet. Like clouds, icecaps reflect a part of the sun's radiation back to space and act as a cooling influence on the Earth's temperature. Icecaps are integral to thermohaline circulation, which is the process in which temperature and salinity differences in various parts of the oceans drive the ocean currents. If this circulation did not exist, the Earth's polar regions would become colder and the equatorial regions would become hotter. Their respective ecosystems would not survive.

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Disadvantages of Deforestation

Deforestation has always been an extremely contentious political topic, with vast swathes of the world's forests being sacrificed to fuel growth across the world. Environmentalists have argued that widespread deforestation could have grave consequences for the world if it is allowed to continue at its current rate.

Destruction of Habitats
Deforestation destroys the habitats of thousands upon thousands of animals and plants that rely on the forests to provide them with the correct nutrients and environment. Deforestation has already led to the extinction of numerous species, something which can wreak havoc on the food chains in forested areas and upset the ecosystems that exist. Each tree that is cut down is home to numerous species of animals and plants, each of which relies on the habitat the tree provides to survive. Deforestation is believed to have contributed heavily to the extinction of the Bali Tiger.

Soil
Deforestation can have a catastrophic effect on the soil in areas where it is carried out extensively. Deforestation leads to increased soil erosion and also means that depletion of the nutrients contained within the soil can occur. This means that, not only has the original forest been destroyed, but it becomes effectively impossible for the trees to be replaced and for new environments to grow. Prof. Jared Diamond , a physiologist at the University of California, suggests that societies in the past, such as Easter Island, have collapsed due to deforestation-induced soil erosion.

Increased Carbon Dioxide in the Atmosphere
William Laurance and Philip Fearnside, researchers from the Smithsonian Tropical Research Institute in Panama and the National Institute for Amazonian Research in Brazil, respectively, have found a link between the increasing levels of deforestation that are occurring and global warming, suggesting that 2.4 billion tons of greenhouse gases were being omitted as a direct result of deforestation each year. This is because forests suck in carbon dioxide from the atmosphere and release oxygen into it, so if there are fewer forests then the amount of carbon dioxide in the atmosphere will increase.

Uprooting of Indigenous Peoples
Widespread deforestation in areas can lead to the uprooting of indigenous tribes who have lived on that land for centuries. This is a sensitive issue, with many of these peoples having their lives turned upside down by deforestation in their area. They rely on the habitat and the ecosystem for hunting and for food, as well as their centuries-old lifestyles.

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Identify Scrap Brass & Copper

Scrap metal sales are a way for you to earn a little extra money while cleaning out damaged appliances or home fixtures. Brass and copper are both metals commonly found in metal recycling plants. While brass is a product of copper and zinc, there are notable differences in these metals that affect the value of each. Before selling your brass or copper to your local recycling plant, you must determine these differences and separate each piece to ensure a fair price.

Note what the metal is used for. For example, copper is commonly used in cookware and electrical appliance wiring. Brass is used more for decorative art and piping throughout a home.

Examine the color of the metal. Pure copper is pink, while tarnish will give copper a red, orange or green hue. Brass is yellow and tarnish shows black or dark gray.

Hold the metal in your hand to determine its weight. Copper is heavier than brass because of its chemical composition. Copper has the same density and weight as iron while brass is light and flimsy.

Examine any markings on the metal. Stamps that say "Copper Alloy" or "Bronze" also refer to brass metals. Pure copper will most likely be unstamped.

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Salary of an Environmentalist

Environmentalists generally are concerned with protecting the environment, but the incomes environmentalists earn depend on how they choose to turn their concerns into a career. Therefore, there is no overall average salary for environmentalists because their concerns about pollution, water quality, forest conservation and other issues carry them into many different occupations.

Function
Environmentalists often choose careers that allow them to influence environmental policies and public opinions or to change corporate or government practices that harm the environment, according to a "Princeton Review" career guide. For example, environmentalists work as conservationists, engineers, scientists, technicians and public relations specialists in an effort to research and promote environmentally-friendly practices in numerous industries. Their incomes depend on the careers they choose, but "The Princeton Review" indicates that understanding environmental issues is the key to getting a job related to those issues.

Scientists and Engineers
Environmental scientists seek to identify and prevent pollution or other hazards that affect the environment and the health of the surrounding population. They examine food, soil and water sources to recommend ways to improve their quality with better environmental practices. Data from the U.S. Bureau of Labor Statistics show that environmental scientists earn a mean salary of $67,810, as of 2010. Environmental engineers may research and design waste-treatment and pollution-control technologies to eliminate or reduce environmental hazards. Environmental engineers earn a mean salary of $83,160 as of 2010, based on BLS data.

Conservation Work
Forest and conservation workers help protect forest, woodlands, wetlands and other areas by planting trees and combating diseases that harm plants. They also build structures to control water flow and prevent soil erosion. The BLS indicates that as of 2010 figures, conservation workers earn about $27,740. Forest and conservation technicians gather data on the condition of forests and other areas. Their duties include tracking the movement of wildlife and examining insect damage to plants and trees. As of 2010 conservation technicians earn a mean salary of $36,860.

Other Jobs
Some environmentalists may choose occupations in which they're indirectly involved with energy conservation by installing solar, wind and other energy-producing systems to conserve electric power. For example, the BLS indicates that solar photovoltaic installers may earn starting salaries that range from $30,000 to $40,000 per year. Other environmentalists may work with organizations as public relations specialists to promote an organization's environmental concerns. The overall mean salary for public relations specialists as of 2010 is $59,150, according to the BLS.

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Uses of Cobalt in Polyester Resins

Polyester resin is ubiquitous in modern life. It is used to make many items, including wall and ceiling panels, car engine covers and circuit breakers for electrical appliances. Cobalt-based products are added to the polyester resin to ensure proper curing or hardening to a solid state.

Polyester Resin
The building blocks of polyester resin are called monomers. The chemical structures of these monomers are different, depending on the type of resin needed. The monomers form polymer chains. A reactive diluent then bonds the polymer chains. This bonding, or cross linking, process is known as free radical copolymerization. A resin manufacturer can make many types of polyester resins to suit the many different uses.

Curing the Resin
During the curing process, the reactive diluent, which is usually styrene, begins the cross-linking process that bonds the polymer chains until the resin forms a gel and then hardens. Cross-link density determines the strength of the finished product. An initiator, which is usually a peroxide, begins the process by decomposing into highly reactive molecule fractions that start a chain reaction. Accelerators activate the initiator, promoting the decomposition of the initiator as the resin cures at room temperature. The accelerators, or promoters, are almost always a form of cobalt metal salt (cobalt naphthenate, cobalt octoate, or cobalt neodecanoate). Usually the cobalt accelerator is added at about 0.01 phr (parts per hundred resin), although the amount varies depending on the finished product. But small amounts of cobalt can make the difference between a strong, usable finished product and one that is cracked or flawed.

Cobalt
For thousands of years people have used cobalt to make a blue dye. However it wasn’t until 1735 that a Swedish chemist isolated and named the metal. At the time of publication, 39 percent of the cobalt in use comes from Africa — especially the Democratic Republic of Congo and Zambia — where it is a byproduct of copper mining. Cobalt is also a byproduct in the mining of nickel, silver, lead and iron ores, and it is found in meteorites. Cobalt has many uses today. For example, it enhances the performance of rechargeable batteries. It also enhances the high-temperature strength of alloys used in just engines.

Alternatives to Cobalt Accelerators
While the accelerators used in polyester resin manufacture are almost always cobalt products, a company in the Netherlands is developing alternatives that use no cobalt or a smaller amount of cobalt. The company, AkzoNobel, launched the first of its alternative accelerators late in 2010 and plans to launch additional cobalt-free alternatives in 2011.

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What Is Megawatt Hour

A megawatt-hour (MWh) is equal to 1,000 kilowatts or 1 million watts of electricity produced by a power plant that runs continuously for one hour. In other words, one megawatt-hour is equivalent to the total amount of electrical energy produced by a power plant that can power about 330 homes in one hour. By learning important concepts about a megawatt hour, you will not only be able to perform relevant calculations, but know the different types of electric power-generating plants.

Calculation
You can calculate the actual amount of energy produced by an electric power plant in one year, E, in megawatts hours (MWh) by multiplying the plant’s capacity (C) in megawatts (MW) by the number of hours in one year, 8,760.

Conversion
Converting megawatts-hours into other multiple units of watts and megawatt-hours, including gigawatts, megawatts, kilowatts, gigawatt-hours, megawatt-hours, and kilowatt-hours, involves formulas that employ basic division and multiplication skills. For example, to convert megawatt-hour to megawatts, you can divide the number of megawatt hours by the number of hours using a calculator.

Cost
Power utility companies sell electrical energy in units of kilowatt-hour. Several market forces determine the wholesale price, including demand and time of day, while the state regulates retail prices. For example, in the United States, for all sectors of usage, the average retail price of electricity for March 2011 was 9.66 cents per kilowatt-hour (kWh). Thus in megawatt-hour, the retail price was 9.66 cents multiplied by 1,000, or $96.60.

Plant Types
Commonly used power plants, according to Edison Electric Institute, include coal, petroleum, natural gases, biomass, geothermal, solar, wind, nuclear electric power, and hydroelectric pumped storage. Different regions or states use different plants depending on several factors, including availability, quality, and cost of fossil fuels used by electric power generating plants. Throughout 2010, in the United States, the net generation by all energy sources totaled 4,120,028 megawatt-hours.

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White-Tailed Deer Feet Adaptation

White-tailed deer, members of the order Artiodactyla, usually inhabit hardwood forests, forest edges, streams, marshes and brushy areas. The male deer is called a buck and typically weighs about 300 pounds while the female is called a doe is smaller at approximately 110 pounds. White-tailed deer change their color from red-brown in summer to gray-brown in the winter and show specific hoof adaptations to the environment.

Glands
White-tailed deer have metatarsal and tarsal glands on their feet. These glands are found on the deer's hind legs. They use the tarsal gland on the inner surface of the hind legs to identify individual deers while the metatarsals on the lower outer surface of the hind legs help in controlling the deer's temperature. The secretions from the glands on the feet serve to describe a deer's health and breeding condition. The secretions can also describe the social status of the deer. They do this by using urine to wash their scent from the metatarsal glands to a scrape made on a tree.

Sharp Hooves
The white-tailed deer has sharp hooves which are used as defensive weapons for fighting predators, which include humans. The hooves at the front are longer than the rear hooves and the deer is likely to use the front hooves more than the rear ones. It can easily kill a wolf with a blow from the front hooves. The deer also utilizes the sharp hooves to make scrapes in trees to mark their scent during the mating seasons and to dig for food.

Long Legs
The legs of a white-tailed deer are adapted to enhance running and leaping. They can run at about 30 miles per hour and jump at a remarkable height of 10 feet. Their legs have powerful muscles and ligaments which provide extra spring and increase the speed and thrust in a deer's stride. The outer layer of the hoof is strong and this helps absorb the shock as the deer lands on the ground. The hoof's inner surface is softer and tougher to provide cushion and traction on harder surfaces. These deer seldom fall except when the terrain is covered by ice. Their ability to run incredibly fast is part of what protects them from predators.

Foot Stomp
When a white-tailed deer senses there is danger lurking or something is amiss in the vicinity, it will raise its front legs and stomp forcefully on the ground. This is done to startle the dangerous creature or individual and to alert and warn other deer nearby. Inter digital glands located between the deer's hooves secrete a scent as the deer stomps its feet. This scent will warn other deers that pass the location later that there was danger here.

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Persistent & Non-Persistent Chemicals

Chemicals can be classified as persistent and nonpersistent chemicals. Chemicals are released into the environment by human action. For instance, a chemical could be introduced into the environment by the use of pesticides. Some of these chemicals endure in the environment for a long time, while some linger for a shorter period.

Persistent Chemicals
Persistent chemicals are those chemicals that tend to endure in the environment for years after they are released into it. It takes longer to remove them from the environment after their use is over. For instance, if pesticides containing persistent chemicals have been sprayed, it is difficult to get the chemicals out of the environment even after they have served their purpose. Examples of persistent chemicals are chlorinated hydrocarbons such as aldrin and lindane.

Nonpersistent Chemicals
Nonpersistent chemicals are those chemicals that linger only for a brief period after their release in the environment. This category of chemicals includes organophosphates such as guthion and malathion. As well, chlorinated hydrocarbons such as endosulfan fall into this category.

Life Span
A chemical's half life is the time it takes for half the material to break down and degenerate. In the case of persistent chemicals, their half lives could range from anywhere between months and decades. In the case of nonpersistent chemicals, their half lives are as short as hours and could run into weeks at most.

Toxic Effects
Nonpersistent chemicals tend to have a more immediate toxic action than persistent chemicals. Nonpersistent chemicals tend to affect humans, causing poisoning, within a few hours after contact. Once they degenerate, they no longer pose a toxic threat. Persistent chemicals, on the other hand, tend to reveal their hazardous effects over the long term. Humans exposed to persistent chemicals could develop cancer and liver disease. As persistent chemicals linger in the environment, they tend to affect some animals more than others. For example, there is some concern that exposure to persistent chemicals could damage the reproductive capabilities of creatures such as the peregrine falcon and the seal.

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Causes of Urban Encroachment

Urban encroachment, also known as urban sprawl, is a key concept in planning and land use. While definitions vary widely, urban encroachment is characterized by economic and business development outside of concentrated urban centers. Urban sprawl is also characterized by low-density housing and retail development in suburban areas adjacent to larger urban centers.

Characteristics of Urban Encroachment
Policy analyst Anthony Downs has identified 10 traits of urban encroachment. According to Downs, urban encroachment is characterized by an "unlimited outward extension" of development beyond a compact urban area; "leapfrog development," in which residential development occurs far from the urban center and bypasses suitable parcels of land closer to the urban center; low-density residential and commercial development; dispersal of power among many small localities rather than one local government; automobiles rather than public transport as the dominant means of transportation; strip commercial development; unplanned land development with no central planning or control agency; large economic disparities and inequalities among localities; land use that is segregated into different zones such as residential and commercial; and a reliance on what Downs terms "trickle down" processes to provide housing to low-income residents.

Causes of Urban Encroachment
While the causes of urban encroachment vary depending on the locale, there are some common factors. In the United States, a major cause of urban encroachment appears to be the desire for single family housing, especially large houses with large lawns. Encouragement of commercial development along major roads and highways, rather than in concentrated urban centers, also contributes to urban encroachment; strip malls and strip centers are most often the result. Lack of public transportation in many areas and Americans' over-reliance on their cars, also promotes urban encroachment.

Impacts of Urban Encroachment
Urban encroachment has several deleterious effects on the environment, though a lack of understanding of these effects appears to be a contributing factor in encroachment. At the most basic level, urban encroachment consumes thousands of acres of woodland and farmland, negatively effecting the animals and plant life that call them home. The reliance on automobiles that characterizes urban encroachment contributes to higher pollution from emissions as well. Groundwater quality suffers from development and industrial pollution can further erode groundwater and soil quality. Economic impacts of urban encroachment include the flight of commerce from urban centers, which may contribute to unemployment and urban blight. The dispersed nature of economic benefit from urban encroachment, as well as the fragmentation of power among many small localities, may lead to underfunded (and thus undermaintained) infrastructure, including highways and public services. Less tangible impacts of urban encroachment include a loss of community as people live further away from each other and in the relative isolation of single-family homes. This isolation and lack of connection can, according to some social scientists, negatively impact quality of life.

Solutions to Urban Encroachment
Planners have suggested several solutions to urban encroachment. These include public investment in public transit; recycling of existing buildings rather than continuous new construction; encouraging investment in urban centers as a way to bring businesses and residents back into these areas; and placing stricter regulations on developers so they are more accountable to the public.

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Lower NOX That Is High

The exhaust gas recirculation (EGR), or engine intake system, is the part of an engine that is responsible for pollution control. The EGR reduces the amount of Nitrous Oxide (NOx) emitted from the engine. The EGR valve re-circulates exhaust gas back into the combustion chamber. By re-circulating these gases, their temperature cools and consequently the amount of NOx created in the chamber is reduced. If NOx is found to be too high, cleaning or replacing the EGR valve is necessary.

Put on the gloves and goggles for safety. Ensure that the engine has not run for four or five hours. The EGR valve can be hot if you attempt to remove it after operating the engine.

Consult the owner’s manual of your vehicle to identify the position of your car’s intake system. Once you have done that, locate the EGR valve. It has a shape resembling a mushroom.

Detach the vacuum hose and electrical connector attached to the EGR valve by unclamping them from the valve.

Unscrew the two bolts found on the side of the valve with a wrench that corresponds with the size of the bolts. Disconnect the pipe underneath the valve using a wrench that corresponds with the size of the pipe.

Inspect the passages of the EGR valve. If there is heavy carbon buildup inside the passages, gently use the scratch awl to clear out the carbon deposits. This is the likely cause of the high NOx reading and won’t require a new EGR valve. If you find little to no carbon deposits, the EGR valve itself is likely damaged and must be replaced.

Return the old valve or put the new valve back in position. Reattach the pipe and volts. Clamp the vacuum hose and electrical connector back in their original positions.

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How Deforestation Affects Weather

Deforestation occurs when trees in a forest are destroyed faster than they can replace themselves. Natural deforestation happens during extreme weather events such as hurricanes and ice ages. Fire from lightning or volcanic eruptions destroys trees. Man-made deforestation is the clearance of trees so the land may be used for agricultural crops, ranches and urban development. Forests affect cloud formation, rainfall and temperature. They regulate weather through their absorption of solar energy, creation of rainfall and exchange of atmospheric gases. Deforestation causes soil erosion and flooding.

Albedo
Albedo is the measure of the power with which any surface reflects sunlight. Forests absorb solar radiation through leaves on trees and have a low albedo. Deforested regions have a high albedo and reflect more solar energy. As the albedo increases with deforestation, the reduction of absorbed energy also reduces air convection currents and rainfall. The daily variation of temperatures increases with forest clearance.

Evapotranspiration
Forests absorb water and nutrients from the soil through their root systems and evaporate it back into the atmosphere from their leaves. This is the process of evapotranspiration where the tree acts as a humidifier for the air. Most of the moisture in inland regions such as Central Africa comes from forests. Coastal regions receive moisture from water vapor evaporation from the surface of the oceans. Deforestation slows down precipitation and leads to drought. As tree roots no longer tap ground water, the groundwater levels fall. Tree roots also hold the soil together. Their removal loosens the soil, causing erosion and flooding.

Aerodynamics
The topmost leaves in a forest, the canopy, create a rough surface. The roughness provides friction with air currents and increases air turbulence. The turbulence provides momentum to global air circulation patterns. Tropical rain forests pump heat into the atmosphere during evapotranspiration. This air in turn circulates to cooler temperate regions on the globe. Forests also allow some air through the trees as well as over and around them. This way they slow down winds. Deforestation contributes to an increase of local wind speeds and a cooling of temperate regions.

Pollution
Forest-clearing fires release aerosols -- particulate matter such as soot -- into the atmosphere. Aerosols both heat and cool the air. Light-colored particles reflect incoming solar radiation back into space and contribute to falling temperatures. Dark-colored particles absorb solar radiation and increase temperatures. Clouds form around soot aerosols but the cloud droplets do grow large enough to trigger rainfall. The decomposition of organic matter after a fire increases carbon dioxide levels in the atmosphere.

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Hazards of Polyethylene Bags

According to the United States Environmental Protection Agency, the world uses approximately 500 billion to one trillion plastic bags annually. Less than one percent of these plastic bags are recycled since it is more expensive to recycle a polythene bag than to make a new one. Polythene bags are widely used since they are light in weight, readily available and inexpensive. Plastic bags are discarded after use littering the environment and creating an eyesore. Apart from this visual pollution, they produce catastrophic effects on the entire environment.

Poor Soils
Polythene bags accumulate continuously on soils and since they cannot decompose and rot easily it results in poor soil aeration and absorption of water and nutrients in the soil. The acidic combination present in the polythene bags also interferes with the chemical formula of the soils making them less productive. Polythene bags photo-degrade breaking down into smaller and toxic petro-polymers contaminating the soil. Crops planted on such soils might produce low yields due to poor nutrition and water absorption.

Threat to Animal Survival
Animals such as sheep and cows might feed on plastic bags in their search for food leading to death since they are difficult to digest. Plastics can also cause a slow death as they are not easily ingested and remain in the intestines for a long period of time. Since plastics are bulky, they take up most of the space in the stomach, thus the animal is unable to feed properly, starving to death. Marine animals easily mistake plastic bags littering seas, oceans, lakes and rivers for food chocking and suffocating them to death. Small children and infants can also suffocate to death by blocking their mouths and nostrils with airtight plastic bags when playing, un-monitored by adults.

Pollution
Polythene bags are durable and since they do not decompose easily, they pile up resulting in a mountain of trash. Polythene bags take up a lot of land to dispose since they are generated in large numbers and hardly decompose. When plastic bags are buried in the landfills, they take a lot of time to rot since they are made from petroleum which is not easily broken down. Plastic bags also pollute the water ways and land when carelessly disposed. The only way of getting rid of plastics is burning them up and this produces toxic fumes which pollute the air.

Spread of Diseases
Discarded polythene bags can clog and block the drainage system resulting to overflow of sewerage. In developing countries with poor sanitation, exposed sewage might mix with drinking water contaminating it, causing water borne diseases such as typhoid and cholera. Rainwater collects in polythene bags, providing a breeding ground for mosquitoes in tropical areas leading to the spread of malaria and yellow fever. Malaria is responsible for the high infant mortality rate in Africa especially during the wet season. Polythene bags can also harbor rats and mice which might transmit diseases and fleas to human beings.

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