Question

Write a 2 to 3 page, (750-1000 word) expanded definition of a technical or scientific term, plus works cited page.

For Example topics can be:

Environmental Science:

What is Global Warming?

What is Acid Rain?

What is biodegradation?

Engineering:

What is a suspension bridge?

What is a hydraulic lift?

What are fiber optics?

Digital Technology:

What is Virtual Reality?

What is a hologram?

What is facial recognition technology?

What are biometrics?

Answer 1

Environmental Science:

Global warming: Global Warming is a phenomenon described as heating of the planet of due to an insulation layer formed by the Greenhouse Gases (GHG) over the atmosphere of the earth which traps heat.

Cause: Global warming occurs when carbon dioxide (CO2) and other air pollutants and greenhouse gases collect in the atmosphere and absorb sunlight and solar radiation that have bounced off the earth’s surface. Normally, this radiation would escape into space—but these pollutants, which can last for years to centuries in the atmosphere, trap the heat and cause the planet to get hotter. That's what's known as the greenhouse effect.

How is global warming linked to extreme weather: Scientists agree that the earth’s rising temperatures are fueling longer and hotter heat waves, more frequent droughts, heavier rainfall, and more powerful hurricanes. In 2015, for example, scientists said that an ongoing drought in California—the state’s worst water shortage in 1,200 years—had been intensified by 15 percent to 20 percent by global warming. They also said the odds of similar droughts happening in the future had roughly doubled over the past century.

Effects of global warming:

• Melting glaciers, early snowmelt, and severe droughts will cause more dramatic water shortages and increase the risk of wildfires in the American West.
• Rising sea levels will lead to coastal flooding on the Eastern Seaboard, especially in Florida, and in other areas such as the Gulf of Mexico.
• Forests, farms, and cities will face troublesome new pests, heat waves, heavy downpours, and increased flooding. All those factors will damage or destroy agriculture and fisheries.
• Disruption of habitats such as coral reefs and Alpine meadows could drive many plant and animal species to extinction.
• Allergies, asthma, and infectious disease outbreaks will become more common due to increased growth of pollen-producing ragweed, higher levels of air pollution, and the spread of conditions favorable to pathogens and mosquitoes.

Acid rain: Acid rain caused by emission of SO2 and
NOX from various sources to the
atmosphere and they dissolve in
atmospheric water and produce acids in
the rain water. SO2 does not react much in
the atmospheric chemicals but it can
travel quicker to long distances and when
get contact with ozone or hydrogen
peroxide it produces SO3, which is highly soluble in water and form sulphuric acid.
Sulphur dioxide is naturally produced by
volcanic eruptions, sea spray, planktons,
rotting vegetation and forest fires.
Anthropogenic sources 69.4 % of Sulphur
dioxide released from industrial
combustion (point sources), house hold
heating of fire wood and coal (area or
non-point sources) and 3.7% from
transportation (mobile sources). Coal
burning sources such as coal power
plants, coal powered engines in vehicles,
smelting of metal ore, production of iron
and steel, process pure metal (obtaining
pure metals of Zn, Ni & Cu) oil refinery,
domestic and industrial boilers, it also
released from the manufacture of
sulphuric acid during the production of
disinfectants, bleaching agents and
fumigants. NOX is naturally produced by
lightening, bacterial action, forest fire and
volcanoes, manmade emission are by
automobiles (43%) and fertilizer
industries, utility plants and other
industrial combustion (32%).

Effects on surface water: Acid rain releases aluminum from the soil into lakes and streams which is toxic to
many aquatic organisms. According to
natural surface effects of deposition about
75% of the lakes and about 50% of the
streams in U.S are acidified as the pH falls
below 5. Similarly, in eastern Canada
about 14,000 lakes were reported as
acidic. Soft waters with low alkaline metal
ions are more susceptible to acidification.

Effects on forest: Acid precipitation on vegetation reduces
the photosynthesis and growth also
increase the susceptibility to draught and
disease, process called ‘dieback’ it causes
browning of leaf and fall off in addition, effects such as thinning of annual growth ring and reduction in

biomass (due to reduced growth), it also
damage the fine root system, affect root
mycorrhiza (due to increase in Al and
acidity) and decrease the lichens,
reduction of soil fertility as potassium
leached out of the soil, phosphorus is also
reduced this reduces the fruit production,
toxic metals such as zinc and aluminum
accumulates, aluminum toxicity retard
root growth and causes loss of
chlorophyll.

Health effects:
The causing agents of acid rain SO2, SO3
and NOx may affect the health particularly
SO2 & SO3 effect on asthma and
emphysema patients and increase the
incidence (Phamornsuwana, n.d.).
Particulate deposition of particles less
than PM 2.5 can even reach the blood
stream via lungs and cause harmful
effects such as lung cancer.

Conclusion:

Acid rain is one of the world’s major
environmental problems since 19th
century. Coal burning is the major cause
of SO2 production and also vehicle
emission and various fossil fuel based
power generation emits NOx. Both SO2
and NOx produces suplhuric and nitric
acid respectively by reacting with atmospheric water vapour and
precipitate as wet deposition such as rain,
snow, sleet and fog and dry deposition
including hazardous particles of PM 2.5.

Biodegradation: Biodegradable refers to the ability of materials to break down and return to nature. In order for packaging products or materials to qualify as biodegradable, they must completely break down and decompose into natural elements within a short time after disposal – typically a year or less.

Process: The process of biodegradation can be divided into three stages: biodeterioration, biofragmentation, and assimilation.Biodeterioration is sometimes described as a surface-level degradation that modifies the mechanical, physical and chemical properties of the material. This stage occurs when the material is exposed to abiotic factors in the outdoor environment and allows for further degradation by weakening the material's structure. Some abiotic factors that influence these initial changes are compression (mechanical), light, temperature and chemicals in the environment.While biodeterioration typically occurs as the first stage of biodegradation, it can in some cases be parallel to biofragmentation. Biofragmentation of a polymer is the lytic process in which bonds within a polymer are cleaved, generating oligomers and monomers in its place. The resulting products from biofragmentation are then integrated into microbial cells, this is the assimilation stage. Some of the products from fragmentation are easily transported within the cell by membrane carriers. However, others still have to undergo biotransformation reactions to yield products.