The composition of air

Air is what we need to breathe. It is approximately 21% oxygen with the remainder mostly nitrogen with a very small amount of various gases thrown in at the end. The most important aspect of air is the 21% oxygen. At sea level, this gives our bodies approximately 95% oxygen inhalation which is what we need for metabolism and survival.

Air is always 21% oxygen, but percent is a portion of something.

21% of an apple is a larger amount than 21% of a grape. At sea level, we mentioned before, the 21% oxygen is enough to sustain life. At much higher altitudes, the atmosphere is still 21% oxygen, but the total quantity of air is a lesser amount, therefore this 21% oxygen is not enough to sustain life. We will need supplemental oxygen in order to live. This is why jet pilots and people who climb mountains such as Everest must have supplemental oxygen, or they will die.

The nitrogen in the air is not important for survival. In fact, people who require machines to give them supplemental oxygen; i.e. people with emphysema or other respiratory or circulatory diseases that require supplemental oxygen at sea level, get the 95% oxygen that they need from the machine. The nitrogen is blown back into the air in the room. Good circulation in the room is adequate to supply enough oxygenated air for the machine to work properly.

To summarize, what we concern ourselves with in everyday live is air; but, the portion of air that is oxygen is what we need to survive.

http://www.helium.com/items/504965-the-composition-of-air

Understanding air to air intercoolers

Engine Performance Parts improve supercharger performance...

I am compiling a guide on information on how to pick the exact engine performance parts to fit your target power requirements. Basically I want to eliminate all the guess work out of tuning and save you some money from having to do things over and over again.

While I was doing research for 'buying the right intercooler' I got lost, honestly.

There are two types of information you will find out there:

1-One class of articles is written by engineers talking about pressure differentials, thermal efficiencies, enthalpy and multi variable equations that are very remotely related to flow, horsepower, torque, supercharger rpm or other things that we KNOW that we can use as an input to our equations. (Basically this science needs to be translated to layman's terms)

2-The other class is a group of random trial and error advice by enthusiasts, press releases and other materials that you find online.

Here's what we do know:

First let's talk about how intercoolers work. There is some debate about whether the intercooler is like a heat sink whose function is to absorb thermal energy from the incoming air to prevent the heat from reaching the engine, or whether the intercooler is like a radiator, where the air flow over the intercooler is responsible for extracting heat from the inlet air charge.

The true answer is both are correct...

The air running through the intercooler spends very little time inside the intercooler and slowing it down for more thermal exchange (like we would coolant in the radiator) would mean preventing air from reaching the engine which is a restriction on power. Because the air spends little time in the intercooler, the intercooler usually has multiple passages, internal ribs, and fins inside of it to maximize the surface area contact between the intercooler aluminum and the compressed air molecules. In this sense, the overall volume of the intercooler, and the overall surface area of its internal surfaces are like a heat sink that absorbs the heat energy out of the compressed air. In this aspect it makes sense that the larger our intercooler, the better. Furthermore it also makes sense, that the more complex and intricate the internal passages of our core, the more heat we will be able to extract out of the charge air. Of course the flipside of this is that very complex internal passages can create turbulence and restrict airflow so ultimately there is a balance in good design

between internal complexity and flow capacity.

When we start out, the intercooler is cold, and with our first power run, as the hot compressed air runs through the intercooler, the heat is transferred to our heat sink (which is the intercooler) and nice cool air is left to enter the engine. After the first run, the intercooler is warm; and if we were to make a second power run back to back, the intercooler will not be able to SINK much heat because it is already somewhat heated.

This is where the intercooler as a radiator comes in, the heat that was transferred from the air to the intercooler core, needs to be taken away either by cross flowing air in an air to air intercooler, or by cooling fluid in an air to water intercooler, or even by an ice-water bath for drag racing applications. Without harvesting the heat that the intercooler has absorbed out of the compressed air, the intercooler will heat up run after run until its temperature is the same as the compressed air heating it. At this point there is no temperature difference between the air and the intercooler core and we can no longer SINK any heat.

Some cars have their intercoolers located under the car's hood (like the Mazda Sentia / 626). In this kind of installation the intercooler is mostly a heat sink and will be used for a few passes till it soaks, once it soaks it needs to be left to cool till it returns to under hood temperatures before it can be effective again as an intercooler. From this we gather, that any intercooler no matter how small, or poorly placed is better than no intercooler because at least for that first power run it will potentially increase horsepower.

MORE AT: http://www.helium.com/items/1509590-intercooler-supercharger-turbocharger-air-to-air-aftercooler-charge-cooler?page=1

The Tragedy of the Commons

The Effects of air pollutions today

The term "Tragedy of the Commons" was coined by Garrett Hardin in a 1968 magazine article, however, the idea dates back to the days of Aristotle. Briefly, it holds that a shared resource is inevitably ruined by uncontrolled use.

Hardin uses a community field or common to explain the concept. The town’s people bring their cows to the common to feed on its grass. Everyone wants to get grass for their cows before it is gone. No one thinks through the consequences of so many cows eating the grass to depletion, and the Tragedy of the Commons occurs. The grass disappears and the common is ruined.

There are many non-fictional abuses that people feel are examples of the phenomenon. Some include human-created air pollution; the hunting of the American buffalo to near extinction in the 1800s; the widespread abuse and destruction of rainforests and our oceans’ coral reefs; and human-induced climate change due largely to the burning of fossil fuels for energy use.

Some people believe that the Tragedy of the Commons can only be averted by making most commodities private property instead of freely available to all. But how does someone own the air or the ocean? And can the air and ocean stay unpolluted with populations of 10 million or more in the world’s megacities? Another proposed solution are laws and taxing devices which would make it more costly to serve one’s self interest over the common good. For now, almost everyone can agree that such vital resources need some form of control so that they can be sustained and the Tragedy of the Commons avoided.

http://www.windows.ucar.edu/tour/link=/milagro/effects/tragedy_commons.html

Pollution's Effects on Us

An inversion layer hangs over residents of Boulder, Colorado.

The air is shared among all living things. When it is polluted by a factory in Asia, a fire in Australia, a dust storm in Africa, or car emissions in North America, the sharing continues despite the fact that these chemicals and particles have detrimental effects.

Scientists have determined many of the harmful local effects of air pollution. We know, for instance, that air pollution can negatively impact human health and cause coughs, burning eyes, breathing problems, and even death. We know that atmospheric haze or smog reduces visibility and that acid rain from chemical emissions damages property, pollutes water resources, and can harm forests, wildlife, and agriculture.

But what are the regional and global impacts of air pollution? Through large scientific field campaigns such as MILAGRO, scientists are beginning to track its movement from cities into regional and global environments. Their goal is to determine air pollution’s movement and impact on climate and atmospheric composition locally, regionally, and globally.

Is human-produced air pollution and its effects an example of the "Tragedy of the Commons" –– a concept that states that any resource open to everyone will eventually be destroyed? Despite the fact that people are creating much of today’s air pollution, the answer will ultimately depend on how humankind responds to the problem. A lot has been done to improve air quality in recent decades, but we still have a long way to go.

http://www.windows.ucar.edu/tour/link=/milagro/effects/pollution_effects_overview.html

Sources of air pollution

Sources of air pollution refer to the various locations, activities or factors which are responsible for the releasing of pollutants in the atmosphere. These sources can be classified into two major categories which are:

Anthropogenic sources (human activity) mostly related to burning different kinds of fuel

• "Stationary Sources" include smoke stacks of power plants, manufacturing facilities (factories) and waste incinerators, as well as furnaces and other types of fuel-burning heating devices

• "Mobile Sources" include motor vehicles, marine vessels, aircraft and the effect of sound etc.

• 

• Chemicals, dust and controlled burn practices in agriculture and forestry management. Controlled or prescribed burning is a technique sometimes used in forest management, farming, prairie restoration or greenhouse gas abatement. Fire is a natural part of both forest and grassland ecology and controlled fire can be a tool for foresters. Controlled burning stimulates the germination of some desirable forest trees, thus renewing the forest.

• Fumes from paint, hair spray, varnish, aerosol sprays and other solvents

• Waste deposition in landfills, which generate methane.Methane is not toxic; however, it is highly flammable and may form explosive mixtures with air. Methane is also an asphyxiant and may displace oxygen in an enclosed space. Asphyxia or suffocation may result if the oxygen concentration is reduced to below 19.5% by displacement

• Military, such as nuclear weapons, toxic gases, germ warfare and rocketry

Natural sources

• Dust from natural sources, usually large areas of land with little or no vegetation.
• Methane, emitted by the digestion of food by animals, for example cattle.
• Radon gas from radioactive decay within the Earth's crust.Radon is a colorless, odorless, naturally occurring, radioactive noble gas that is formed from the decay of radium. It is considered to be a health hazard.Radon gas from natural sources can accumulate in buildings, especially in confined areas such as the basement and it is the second most frequent cause of lung cancer, after cigarette smoking.

• Smoke and carbon monoxide from wildfires
• Volcanic activity, which produce sulfur, chlorine, and ash particulates.

• 

From Wikipedia, the free encyclopedia

Air pollution

Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or damages the natural environment, into the atmosphere.

The atmosphere is a complex, dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth's ecosystems.

Air Pollution

Pollutants

An air pollutant is known as a substance in the air that can cause harm to humans and the environment. Pollutants can be in the form of solid particles, liquid droplets, or gases. In addition, they may be natural or man-made.

Pollutants can be classified as either primary or secondary. Usually, primary pollutants are substances directly emitted from a process, such as ash from a volcanic eruption, the carbon mon

oxide gas from a motor vehicle exhaust or sulfur dioxide released from factories.

Smoke from factory

Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. An important example of a secondary pollutant is ground level ozone - one of the many secondary pollutants that make up photochemical smog.

Note that some pollutants may be both primary and secondary: that is, they are both emitted directly and formed from other primary pollutants.

About 4 percent of deaths in the United States can be attributed to air pollution, according to the Environmental Science Engineering Program at the Harvard School of Public Health.

Major primary pollutants produced by human activity include:

• Sulfur oxides (SO_x) - especially sulfur dioxide, a chemical compound with the formula SO₂. SO₂ is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide. Further oxidation of SO₂, usually in the presence of a catalyst such as NO₂, forms H₂SO₄, and thus acid rain.[2] This is one of the causes for concern over the environmental impact of the use of these fuels as power sources.
• Nitrogen oxides (NO_x) - especially nitrogen dioxide are emitted from high temperature combustion. Can be seen as the brown haze dome above or plume downwind of cities.Nitrogen dioxide is the chemical compound with the formula NO₂. It is one of the several nitrogen oxides. This reddish-brown toxic gas has a characteristic sharp, biting odor. NO₂ is one of the most prominent air pollutants.
• Carbon monoxide - is a colourless, odourless, non-irritating but very poisonous gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.
• Carbon dioxide (CO₂) - a greenhouse gas emitted from combustion but is also a gas vital to living organisms. It is a natural gas in the atmosphere.
• Volatile organic compounds - VOCs are an important outdoor air pollutant. In this field they are often divided into the separate categories of methane (CH₄) and non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas which contributes to enhanced global warming. Other hydrocarbon VOCs are also significant greenhouse gases via their role in creating ozone and in prolonging the life of methane in the atmosphere, although the effect varies depending on local air quality. Within the NMVOCs, the aromatic compounds benzene, toluene and xylene are suspected carcinogens and may lead to leukemia through prolonged exposure. 1,3-butadiene is another dangerous compound which is often associated with industrial uses.

• Particulate matter - Particulates, alternatively referred to as particulate matter (PM) or fine particles, are tiny particles of solid or liquid suspended in a gas. In contrast, aerosol refers to particles and the gas together. Sources of particulate matter can be man made or natural. Some particulates occur naturally, originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray. Human activities, such as the burning of fossil fuels in vehicles, power plants and various industrial processes also generate significant amounts of aerosols. Averaged over the globe, anthropogenic aerosols—those made by human activities—currently account for about 10 percent of the total amount of aerosols in our atmosphere. Increased levels of fine particles in the air are linked to health hazards such as heart disease, altered lung function and lung cancer.

• Toxic metals, such as lead, cadmium and copper.
• Chlorofluorocarbons (CFCs) - harmful to the ozone layer emitted from products currently banned from use.
• Ammonia (NH₃) - emitted from agricultural processes. Ammonia is a compound with the formula NH₃. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceuticals. Although in wide use, ammonia is both caustic and hazardous.
• Odors - such as from garbage, sewage, and industrial processes
• Radioactive pollutants - produced by nuclear explosions, war explosives, and natural processes such as the radioactive decay of radon.

Secondary pollutants include:

• Particulate matter formed from gaseous primary pollutants and compounds in photochemical smog .Smog is a kind of air pollution; the word "smog" is a portmanteau of smoke and fog. Classic smog results from large amounts of coal burning in an area caused by a mixture of smoke and sulfur dioxide. Modern smog does not usually come from coal but from vehicular and industrial emissions that are acted on in the atmosphere by sunlight to form secondary pollutants that also combine with the primary emissions to form photochemical smog.
• Ground level ozone (O₃) formed from NO_x and VOCs. Ozone (O₃) is a key constituent of the troposphere (it is also an important constituent of certain regions of the stratosphere commonly known as the Ozone layer). Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night. At abnormally high concentrations brought about by human activities (largely the combustion of fossil fuel), it is a pollutant, and a constituent of smog.
• Peroxyacetyl nitrate (PAN) - similarly formed from NO_x and VOCs.

Minor air pollutants include:

• A large number of minor hazardous air pollutants. Some of these are regulated in USA under the Clean Air Act and in Europe under the Air Framework Directive.
• A variety of persistent organic pollutants, which can attach to particulate matter.

Persistent organic pollutants (POPs) are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Because of this, they have been observed to persist in the environment, to be capable of long-range transport, bioaccumulate in human and animal tissue, biomagnify in food chains, and to have potential significant impacts on human health and the environment.