Thursday, August 20, 2015

The Waste Management

the waste management

The term usually relates to all kinds of waste, whether generated during the extraction of raw materials, the processing of raw materials into intermediate and final products, the consumption of final products, or other human activities,[1] including municipal (residential, institutional, commercial), agricultural, and special (health care, household hazardous wastes, sewage sludge).[2] Waste management is intended to reduce adverse effects of waste on health, the environment or aesthetics.

history in waste management


Throughout most of history, the amount of waste generated by humans was insignificant due to low population density and low societal levels of the exploitation of natural resources. Common waste produced during pre-modern times was mainly ashes and human biodegradable waste, and these were released back into the ground locally, with minimum environmental impact. Tools made out of wood or metal were generally reused or passed down through the generations.
However, some civilizations do seem to have been more profligate in their waste output than others. In particular, the Maya of Central America had a fixed monthly ritual, in which the people of the village would gather together and burn their rubbish in large dumps.[4]
solutions

Disposal of waste in a landfill involvesquarriesmining voids or borrow pits. A properly designed and well-managed landfill can be a hygienic and relatively inexpensive method of disposing of waste materials. Older, poorly designed or poorly managed landfills and open dumps can create a number of adverse environmental impacts such as wind-blown litter, attraction of vermin, and generation of liquidleachate. Another common product of landfills is gas (mostly composed of methane and carbon dioxide), which is produced fromanaerobic breakdown of organic waste. This gas can create odor problems, kill surface vegetation and is a greenhouse gas.
burying the waste and this remains a common practice in most countries. Landfills were often established in abandoned or unused


recycling

Recycling is a resource recovery practice that refers to the collection and reuse of waste materials such as empty beverage containers. The materials from which the items are made can be reprocessed into new products. Material for recycling may be collected separately from general waste using dedicated bins and collection vehicles, a procedure called kerbside collection. In some communities, the owner of the waste is required to separate the materials into various different bins (e.g. for paper, plastics, metals) prior to its collection. In other communities, all recyclable materials are placed in a single bin for collection, and the sorting is handled later at a central facility. The latter method is known as "single-stream recycling."[11][12]
The most common consumer products recycled include aluminium such as beverage cans, copper such as wire, steel from food and aerosol cans, old steel furnishings or equipment, polyethylene and PET bottles, glass bottles and jars, paperboardcartonsnewspapers, magazines and light paper, and corrugated fiberboard boxes.

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The Climate Change

warming and climate change are terms for the observed century-scale rise in the average temperature of the Earth's climate system and its related effects.
Multiple lines of scientific evidence show that the climate system is warming.[2][3] Although the increase of near-surface atmospheric temperature is the measure of global warming often reported in the popular press, most of the additional energy stored in the climate system since 1970 has goGlobal ne into ocean warming. The remainder has melted ice, and warmed the continents and atmosphere.[4][a] Many of the observed changes since the 1950s are unprecedented over decades to millennia.[5]
Scientific understanding of global warming is increasing. The Intergovernmental Panel on Climate Change (IPCC)reported in 2014 that scientists were more than 95% certain that most of global warming is caused by increasing concentrations of greenhouse gases and other human (anthropogenic) activities.[6][7][8] Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to 1.7 °C (0.5 to 3.1 °F) for their lowest emissions scenario using stringent mitigation and 2.6 to 4.8 °C (4.7 to 8.6 °F) for their highest.[9] These findings have been recognized by the national science academies of the major industrialized nations.[10][b]

Causes

On the broadest scale, the rate at which energy is received from the sun and the rate at which it is lost to space determine the equilibrium temperature and climate of Earth. This energy is distributed around the globe by winds, ocean currents, and other mechanisms to affect the climates of different regions.
Factors that can shape climate are called climate forcings or "forcing mechanisms".[6] These include processes such as variations in solar radiation, variations in the Earth's orbit, variations in the albedo or reflectivity of the continents and oceans, mountain-building and continental drift and changes in greenhouse gas concentrations. There are a variety ofclimate change feedbacks that can either amplify or diminish the initial forcing. Some parts of the climate system, such as the oceans and ice caps, respond more slowly in reaction to climate forcings, while others respond more quickly. There are also key threshold factors which when exceeded can produce rapid change.
Forcing mechanisms can be either "internal" or "external". Internal forcing mechanisms are natural processes within the climate system itself (e.g., the thermohaline circulation). External forcing mechanisms can be either natural (e.g., changes in solar output) or anthropogenic (e.g., increased emissions of greenhouse gases).
Whether the initial forcing mechanism is internal or external, the response of the climate system might be fast (e.g., a sudden cooling due to airborne volcanic ash reflecting sunlight), slow (e.g. thermal expansion of warming ocean water), or a combination (e.g., sudden loss of albedo in the arctic ocean as sea ice melts, followed by more gradual thermal expansion of the water). Therefore, the climate system can respond abruptly, but the full response to forcing mechanisms might not be fully developed for centuries or even longer.

Glaciers

Glaciers are considered among the most sensitive indicators of climate change.[64] Their size is determined by a mass balance between snow input and melt output. As temperatures warm, glaciers retreat unless snow precipitation increases to make up for the additional melt; the converse is also true.
Glaciers grow and shrink due both to natural variability and external forcings. Variability in temperature, precipitation, and englacial and subglacial hydrology can strongly determine the evolution of a glacier in a particular season. Therefore, one must average over a decadal or longer time-scale and/or over many individual glaciers to smooth out the local short-term variability and obtain a glacier history that is related to climate.
A world glacier inventory has been compiled since the 1970s, initially based mainly on aerial photographs and maps but now relying more on satellites. This compilation tracks more than 100,000 glaciers covering a total area of approximately 240,000 km2, and preliminary estimates indicate that the remaining ice cover is around 445,000 km2. The World Glacier Monitoring Service collects data annually on glacier retreat and glacier mass balance. From this data, glaciers worldwide have been found to be shrinking significantly, with strong glacier retreats in the 1940s, stable or growing conditions during the 1920s and 1970s, and again retreating from the mid-1980s to present.[65]
The most significant climate processes since the middle to late Pliocene (approximately 3 million years ago) are the glacial and interglacial cycles. The present interglacial period (the Holocene) has lasted about 11,700 years.[66] Shaped by orbital variations, responses such as the rise and fall of continental ice sheets and significant sea-level changes helped create the climate. Other changes, including Heinrich eventsDansgaard–Oeschger events and the Younger Dryas, however, illustrate how glacial variations may also influence climate without the orbital forcing.Glaciers leave behind moraines that contain a wealth of material—including organic matter, quartz, and potassium that may be dated—recording the periods in which a glacier advanced and retreated. Similarly, by tephrochronological techniques, the lack of glacier cover can be identified by the presence of soil or volcanic tephra horizons whose date of deposit may also be ascertained.

Global warming and climate change are terms for the observed century-scale rise in the average temperature of the Earth's climate system and its related effects.
Multiple lines of scientific evidence show that the climate system is warming.[2][3] Although the increase of near-surface atmospheric temperature is the measure of global warming often reported in the popular press, most of the additional energy stored in the climate system since 1970 has gone into ocean warming. The remainder has melted ice, and warmed the continents and atmosphere.[4][a] Many of the observed changes since the 1950s are unprecedented over decades to millennia.[5]
Scientific understanding of global warming is increasing. The Intergovernmental Panel on Climate Change (IPCC)reported in 2014 that scientists were more than 95% certain that most of global warming is caused by increasing concentrations of greenhouse gases and other human (anthropogenic) activities.[6][7][8] Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to 1.7 °C (0.5 to 3.1 °F) for their lowest emissions scenario using stringent mitigation and 2.6 to 4.8 °C (4.7 to 8.6 °F) for their highest.[9] These findings have been recognized by the national science academies of the major industrialized nations.[10][b]

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the global warming

Climate change
Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time (i.e., decades to millions of years). Climate change may refer to a change in average weather conditions, or in the time variation of weather around longer-term average conditions (i.e., more or fewer extreme weather events). Climate change is caused by factors such as biotic processes, variations in solar radiation received by Earth, plate tectonics, and volcanic eruptions. Certain human activities have also been identified as significant causes of recent climate change, often referred to as "global warming".[1]
Scientists actively work to understand past and future climate by using observations and theoretical models. A climate record—extending deep into the Earth's past—has been assembled, and continues to be built up, based on geological evidence fromborehole temperature profiles, cores removed from deep accumulations of icefloral and faunal records, glacial and periglacialprocesses, stable-isotope and other analyses of sediment layers, and records of past sea levels. More recent data are provided by the instrumental record. General circulation models, based on the physical sciences, are often used in theoretical approaches to match past climate data, make future projections, and link causes and effects in climate change.

Terminology

The most general definition of climate change is a change in the statistical properties (principally its mean and spread)[2] of the climate system when considered over long periods of time, regardless of cause.[3] Accordingly, fluctuations over periods shorter than a few decades, such as El Niño, do not represent climate change.
The term sometimes is used to refer specifically to climate change caused by human activity, as opposed to changes in climate that may have resulted as part of Earth's natural processes.[4] In this sense, especially in the context of environmental policy, the term climate change has become synonymous with anthropogenic global warming. Within scientific journals, global warming refers to surface temperature increases while climate change includes global warming and everything else that increasing greenhouse gaslevels will affect.[5]

Causes

On the broadest scale, the rate at which energy is received from the sun and the rate at which it is lost to space determine the equilibrium temperature and climate of Earth. This energy is distributed around the globe by winds, ocean currents, and other mechanisms to affect the climates of different regions.
Factors that can shape climate are called climate forcings or "forcing mechanisms".[6] These include processes such as variations in solar radiation, variations in the Earth's orbit, variations in the albedo or reflectivity of the continents and oceans, mountain-building and continental drift and changes in greenhouse gas concentrations. There are a variety ofclimate change feedbacks that can either amplify or diminish the initial forcing. Some parts of the climate system, such as the oceans and ice caps, respond more slowly in reaction to climate forcings, while others respond more quickly. There are also key threshold factors which when exceeded can produce rapid change.
Forcing mechanisms can be either "internal" or "external". Internal forcing mechanisms are natural processes within the climate system itself (e.g., the thermohaline circulation). External forcing mechanisms can be either natural (e.g., changes in solar output) or anthropogenic (e.g., increased emissions of greenhouse gases).
Whether the initial forcing mechanism is internal or external, the response of the climate system might be fast (e.g., a sudden cooling due to airborne volcanic ash reflecting sunlight), slow (e.g. thermal expansion of warming ocean water), or a combination (e.g., sudden loss of albedo in the arctic ocean as sea ice melts, followed by more gradual thermal expansion of the water). Therefore, the climate system can respond abruptly, but the full response to forcing mechanisms might not be fully developed for centuries or even longer.

Glaciers

Glaciers are considered among the most sensitive indicators of climate change.[64] Their size is determined by a mass balance between snow input and melt output. As temperatures warm, glaciers retreat unless snow precipitation increases to make up for the additional melt; the converse is also true.
Glaciers grow and shrink due both to natural variability and external forcings. Variability in temperature, precipitation, and englacial and subglacial hydrology can strongly determine the evolution of a glacier in a particular season. Therefore, one must average over a decadal or longer time-scale and/or over many individual glaciers to smooth out the local short-term variability and obtain a glacier history that is related to climate.
A world glacier inventory has been compiled since the 1970s, initially based mainly on aerial photographs and maps but now relying more on satellites. This compilation tracks more than 100,000 glaciers covering a total area of approximately 240,000 km2, and preliminary estimates indicate that the remaining ice cover is around 445,000 km2. The World Glacier Monitoring Service collects data annually on glacier retreat and glacier mass balance. From this data, glaciers worldwide have been found to be shrinking significantly, with strong glacier retreats in the 1940s, stable or growing conditions during the 1920s and 1970s, and again retreating from the mid-1980s to present.[65]
The most significant climate processes since the middle to late Pliocene (approximately 3 million years ago) are the glacial and interglacial cycles. The present interglacial period (the Holocene) has lasted about 11,700 years.[66] Shaped by orbital variations, responses such as the rise and fall of continental ice sheets and significant sea-level changes helped create the climate. Other changes, including Heinrich eventsDansgaard–Oeschger events and the Younger Dryas, however, illustrate how glacial variations may also influence climate without the orbital forcing.
Glaciers leave behind moraines that contain a wealth of material—including organic matter, quartz, and potassium that may be dated—recording the periods in which a glacier advanced and retreated. Similarly, by tephrochronological techniques, the lack of glacier cover can be identified by the presence of soil or volcanic tephra horizons whose date of deposit may also be ascertained.

Global Warming
Global warming and climate change are terms for the observed century-scale rise in the average temperature of the Earth's climate system and its related effects.
Multiple lines of scientific evidence show that the climate system is warming.[2][3] Although the increase of near-surface atmospheric temperature is the measure of global warming often reported in the popular press, most of the additional energy stored in the climate system since 1970 has gone into ocean warming. The remainder has melted ice, and warmed the continents and atmosphere.[4][a] Many of the observed changes since the 1950s are unprecedented over decades to millennia.[5]
Scientific understanding of global warming is increasing. The Intergovernmental Panel on Climate Change (IPCC)reported in 2014 that scientists were more than 95% certain that most of global warming is caused by increasing concentrations of greenhouse gases and other human (anthropogenic) activities.[6][7][8] Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to 1.7 °C (0.5 to 3.1 °F) for their lowest emissions scenario using stringent mitigation and 2.6 to 4.8 °C (4.7 to 8.6 °F) for their highest.[9] These findings have been recognized by the national science academies of the major industrialized nations.[10][b]


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Wednesday, August 19, 2015

the community ecosystem


An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment (things like air, water and mineral soil), interacting as a system.[2] These biotic and abiotic components are regarded as linked together through nutrient cycles and energy flows.[3] As ecosystems are defined by the network of interactions among organisms, and between organisms and their environment,[4] they can be of any size but usually encompass specific, limited spaces[5] (although some scientists say that the entire planet is an ecosystem).[6]
Energy, water, nitrogen and soil minerals are other essential abiotic components of an ecosystem. The energy that flows through ecosystems is obtained primarily from the sun. It generally enters the system through photosynthesis, a process that also captures carbonfrom the atmosphere. By feeding on plants and on one another, animals play an important role in the movement of matter and energy through the system. They also influence the quantity of plant and microbial biomass present. By breaking down dead organic matter,decomposers release carbon back to the atmosphere and facilitate nutrient cycling by converting nutrients stored in dead biomass back to a form that can be readily used by plants and other microbes.[7]
Ecosystems are controlled both by external and internal factors. External factors such as climate, the parent material which forms the soil and topography, control the overall structure of an ecosystem and the way things work within it, but are not themselves influenced by the ecosystem.[8] Other external factors include time and potential biota. Ecosystems are dynamic entities—invariably, they are subject to periodic disturbances and are in the process of recovering from some past disturbance.[9] Ecosystems in similar environments that are located in different parts of the world can have very different characteristics simply because they contain different species.[8] Theintroduction of non-native species can cause substantial shifts in ecosystem function. Internal factors not only control ecosystem processes but are also controlled by them and are often subject to feedback loops.[8] While the resource inputs are generally controlled by external processes like climate and parent material, the availability of these resources within the ecosystem is controlled by internal factors like decomposition, root competition or shading.[8] Other internal factors include disturbance, succession and the types of species present. Although humans exist and operate within ecosystems, their cumulative effects are large enough to influence external factors like climate.[8]
Biodiversity affects ecosystem function, as do the processes of disturbance and succession. Ecosystems provide a variety of goods and services upon which people depend; the principles of ecosystem management suggest that rather than managing individual species,natural resources should be managed at the level of the ecosystem itself. Classifying ecosystems into ecologically homogeneous units is an important step towards effective ecosystem management, but there is no single, agreed-upon way to do this.

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Tuesday, August 18, 2015

How do You Breath

The human respiratory system is a series of organs responsible for taking in oxygen and expelling carbon dioxide. The primary organs of the respiratory system are lungs, which carry out this exchange of gases as we breathe.
Red blood cells collect the oxygen from the lungs and carry it to the parts of the body where it is needed, according to the American Lung Association. During the process, the red blood cells collect the carbon dioxide and transport it back to the lungs, where it leaves the body when we exhale.
The human body needs oxygen to sustain itself. A decrease in oxygen is known as hypoxia and a complete lack of oxygen is known as anoxia and, according to MedLine Plus. These conditions can be fatal; after about four minutes without oxygen, brain cells begin dying, according to NYU Langone Medical Center, which can lead to brain damage and ultimately death. 

In humans, the average rate of breathing is dependent upon age. A newborn's normal breathing rate is about 40 times each minute and may slow to 20 to 40 times per minute when the baby is sleeping, according to the Children's Hospital of Philadelphia.
For adults, the average resting respiratory rate for adults is 12 to 16 breaths per minute, according to Johns Hopkins Medicine. Physical exertion also has an effect on respiratory rate, and healthy adults can average 45 breaths per minute during strenuous exercise.

Parts of the respiratory system



As we breathe, oxygen enters the nose or mouth and passes the sinuses, which are hollow spaces in the skull. Sinuses help regulate the temperature and humidity of the air we breathe.
The trachea, also called the windpipe, filters the air that is inhaled, according to the American Lung Association. It branches into the bronchi, which are two tubes that carry air into each lung. The bronchial tubes are lined with tiny hairs called cilia. Cilia move back and forth, carrying mucus up and out. Mucus, a sticky fluid, collects dust, germs and other matter that has invaded the lungs. We expel mucus when we sneeze, cough, spit or swallow.
The bronchial tubes lead to the lobes of the lungs. The right lung has three lobes; the left lung has two, according to the American Lung Association. The left lung is smaller to allow room for the heart, according to the National Heart, Lung and Blood Institute (NHLBI). Lobes are filled with small, spongy sacs called alveoli, and this is where the exchange of oxygen and carbon dioxide occurs.
The alveolar walls are extremely thin (about 0.2 micrometers). These walls are composed of a single layer of tissues called epithelial cells and tiny blood vessels called pulmonary capillaries.
Blood passes through the capillaries. The pulmonary artery carries blood containing carbon dioxide to the air sacs, where the gas moves from the blood to the air, according to the NHLBI. Oxygenated blood goes to the heart through the pulmonary vein, and the heart pumps it throughout the body.
The diaphragm, a dome-shaped muscle at the bottom of the lungs, controls breathing and separates the chest cavity from the abdominal cavity, the American Lung Association noted. When a breath it taken, it flattens out and pulls forward, making more space for the lungs. During exhalation, the diaphragm expands and forces air out.

Diseases of the respiratory system

Diseases and conditions of the respiratory system fall into two categories:  Viruses such as influenza, bacterial pneumonia and the new enterovirus respiratory virus that has been diagnosed in children; and chronic diseases, such as asthma and chronic obstructive pulmonary disease (COPD). According to Dr. Neal Chaisson, who practices pulmonary medicine at the Cleveland Clinic, there is not much that can be done for viral infections but to let them run their course. "Antibiotics are not effective in treating viruses and the best thing to do is just rest," he said.
COPD is the intersection of three related conditions — chronic bronchitis, chronic asthma and emphysema, Chaisson told Live Science. It is a progressive disease that makes it increasingly difficult for sufferers to breath.
Asthma is a chronic inflammation of the lung airways that causes coughing, wheezing, chest tightness or shortness of breath, according to Tonya Winders, president of the Allergy & Asthma Network. These signs and symptoms may be worse when a person is exposed to their triggers, which can include air pollution, tobacco smoke, factory fumes, cleaning solvents, infections, pollens, foods, cold air, exercise, chemicals and medications.
Lung cancer is often associated with smoking, but the disease can affect non-smokers as well. Every year, about 16,000 to 24,000 Americans die of lung cancer, even though they have never smoked, according to the American Cancer Society. Like all cancers, lung cancer is caused by the uncontrolled growth of abnormal cells.

Diagnosing and treating respiratory ailments

Pulmonologists, a subspecialty of internal medicine, treat the respiratory system, including the lungs, according to the American College of Physicians. Because of the critical nature of the respiratory system, pulmonologists work in hospitals as well as in private practice. A pulmonologist must first be certified by the American Board of Internal Medicine and then obtain additional training in the subspecialty.
Common diagnostic tools for diagnosing respiratory disease include chest X-rays and a pulmonary function test (PFT), according to Merck Manuals. A PFT measures how well the lungs take in and release air and how well they circulate oxygen.
A doctor may also perform a bronchoscopy by inserting a tube with a light and camera into the airways — the trachea and the bronchial tubes — to examine for bleeding, tumors, inflammation or other abnormalities, according to the NHLBI. A similar procedure is a thoracoscopy, in which a doctor uses an optical device to examine the surfaces of the lungs.
A physician may order a PFT as part of a routine exam — especially for smokers, according to the University of Pittsburgh Medical Center. A PFT may also be ordered to test lung function before surgery or to help diagnose lung conditions or diseases.
For most healthy individuals, the most common respiratory ailment they may face is an infection, according to Dr. Matthew Exline, a pulmonologist and critical care expert at The Ohio State University Wexner Medical Center. A cough is the first symptom, possibly accompanied by a fever.
"However, cough can be a sign of chronic respiratory conditions such as asthma, chronic bronchitis or emphysema," he said. "In chronic lung disease, most respiratory diseases present with shortness of breath, initially with exertion, such as walking a significant distance or climbing several flights of stairs."
The most certain way to diagnose asthma is with a lung function test, a medical history and a physical exam, according to Winders. "However, it's hard to do lung function tests in children younger than 5 years. Thus, doctors must rely on children's medical histories, signs and symptoms, and physical exams to make a diagnosis."
For COPD, many patients benefit from respiratory rehabilitation, according to Dr. Brian Carlin, assistant professor of medicine at Drexel University College of Medicine. "It is much like cardiac rehabilitation for heart patients, and can provide education, exercise and training to reduce the number of respiratory incidents."

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