greenhouse effect

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					•Gas emissions
•Deforestation and forest fires

•Greenhouse effects

•Radioactive contamination
   Gas emissions are the gases that are released in the atmosphere by
    cars, airplanes, factories etc. Those gases are very harmful for the
    environment and the humans. They are responsible for the
    greenhouse effect and the acid rain . Some of them are greenhouse
    gas and carbon dioxide.
   A greenhouse gas (sometimes abbreviated GHG) is a gas in an
    atmosphere that absorbs and emits radiation within the thermal infrared
    range. This process is the fundamental cause of the greenhouse effect. The
    primary greenhouse gases in the Earth’s atmosphere are water vapor,
    carbon dioxide, methane, nitrous oxide, and ozone. In the Solar System,
    the atmospheres of Venus, Mars, and Titan also contain gases that cause
    greenhouse effects. Greenhouse gases greatly affect the temperature of
    the Earth; without them, Earth's surface would be on average about 33 °C
    (59 °F) colder than at present
   Carbon dioxide (chemical formula CO2) is a naturally
    occurring chemical compound composed of two
    oxygen atoms covalently bonded to a single carbon
    atom. It is a gas at standard temperature and pressure
    and exists in Earth's atmosphere in this state, as a trace
    gas at a concentration of 0.039% by volume.
   Deforestation is the removal of trees in a forest. The main causes
    are to build roads or for urban use. As a result, the production of
    oxygen is being reduced. Furthermore, many of the animals who
    used to live there lose their houses and most of them have
    nowhere else to go as a result to die.
   The four major natural causes of wildfire ignitions are lightning,
    volcanic eruption, sparks from rock falls, and spontaneous
    combustion. By the fires, tones of CO2        are produced and
    thousands of km2 of forest are destroyed.




                         Spacefoto from the fires in
                         Greece in the summer of 2007
   The greenhouse effect is a process by which thermal radiation from a planetary
    surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all
    directions. Since part of this re-radiation is back towards the surface, energy is
    transferred to the surface and the lower atmosphere. As a result, the temperature
    there is higher than it would be if direct heating by solar radiation were the only
    warming mechanism.
                                        
    Solar radiation at the high frequencies of visible light passes through the
    atmosphere to warm the planetary surface, which then emits this energy at the
    lower frequencies of infrared thermal radiation. Infrared radiation is absorbed by
    greenhouse gases, which in turn re-radiate much of the energy to the surface and
    lower atmosphere. The mechanism is named after the effect of solar radiation
    passing through glass and warming a greenhouse, but the way it retains heat is
    fundamentally different as a greenhouse works by reducing airflow, isolating the
    warm air inside the structure so that heat is not lost by convection.
   The greenhouse effect was discovered by French mathematician Joseph Fourier in
    1824, first reliably experimented on by Irish physicist John Tyndall in 1858, and
    first reported quantitatively by Swedish scientist Svante Arrhenius in 1896.
   Ozone depletion describes two distinct but related phenomena observed since the
    late 1970s: a steady decline of about 4% per decade in the total volume of ozone in
    Earth's stratosphere (the ozone layer), and a much larger springtime decrease in
    stratospheric ozone over Earth's polar regions. The latter phenomenon is referred
    to as the ozone hole. In addition to these well-known stratospheric phenomena,
    there are also springtime polar troposphere ozone depletion events.
   The details of polar ozone hole formation differ from that of mid-latitude thinning,
    but the most important process in both is catalytic destruction of ozone by atomic
    halogens. The main source of these halogen atoms in the stratosphere is photo
    dissociation of man-made halocarbon refrigerants (CFCs, freons, halons). These
    compounds are transported into the stratosphere after being emitted at the surface.
    Both types of ozone depletion were observed to increase as emissions of halo-
    carbons increased.
   CFCs and other contributory substances are referred to as ozone-depleting
    substances (ODS). Since the ozone layer prevents most harmful UVB wavelengths
    (280–315 nm) of ultraviolet light (UV light) from passing through the Earth's
    atmosphere, observed and projected decreases in ozone have generated worldwide
    concern leading to adoption of the Montreal Protocol that bans the production of
    CFCs, halons, and other ozone-depleting chemicals such as carbon tetrachloride
    and trichloroethane. It is suspected that a variety of biological consequences such
    as increases in skin cancer, cataracts, damage to plants, and reduction of plankton
    populations in the ocean's photic zone may result from the increased UV exposure
    due to ozone depletion.
   Radioactive contamination, also called radiological
    contamination, is radioactive substances on surfaces, or within
    solids, liquids or gases (including the human body), where their
    presence is unintended or undesirable, or the process giving rise
    to their presence in such places. Also used less formally to refer to
    a quantity, namely the activity on a surface (or on a unit area of a
    surface).
   As with other contamination, radioactive contamination refers
    only to the presence of the unintended or undesired radioactivity,
    and gives no indication of the magnitude of hazard involved
    Radioactive contamination is a result of the 20th century activities in
    atomic physics, such as nuclear power generation and nuclear weapons
    research, manufacture and deployment.
   This is a totally blind long-nose sucker fishcaught
    downstream from the Beaverlodge uranium mill (early
    1980s). This fish is a casualty of radioactive and heavy
    metal pollution — the eyes have no pupils. Blindness
    in fish is a known result of radioactive contamination
    from uranium mines; fish accumulate so much
    radioactivity in their bodies that in some areas
    immediately downstream from uranium mines, they
    present a health hazard if eaten regularly.
•   Georgina Kakaletri G’1/g
•   Rudolph Maslias G’5/g
•   Panos Pappas G’1/g
•   Konstantinos Svourakis G’4/g
•   “Arcturos”
•   “Helmepa”
•   “Animal Welfare”
•   “Greenpeace”
•   “Hellenic Ornithological Society”
•   “Medasset”
     The ARKTOYROS is a non-governmental, non-profit environmental
    organization founded in 1992 for the protection of wildlife and natural
    environment through field research, scientific study, public awareness,
    environmental education and volunteer to protect wildlife, enhance
    biodiversity and sustainability in Greece and abroad.
                                       Activities
   Brown bears once ranged all across Europe, but human encroachment on
    their forest habitats have made them an endangered species. Through the
    efforts of Arcturos, the size of the Greek brown bear population appears to
    have doubled in recent years.
   The organization also undertakes the rescue of bears kept captive in
    inhumane conditions—such as the notorious "dancing bears", which are
    taken as cubs to be trained following the killing of their mother, as well as
    orphan bears and those improperly kept in zoos.
   The Hellenic Marine Environment Protection Association (HELMEPA),
    established in 1982, is Europe’s first private sector voluntary marine
    environment protection association.
   HELMEPA's aims are to eliminate ship-generated marine pollution
    and enhance safety at sea. The Association trains seafarers and
    executives so that they are aware of safety and the protection of the
    marine environment," .
   HELMEPA supports governments in ratifying and implementing
    international conventions on the protection of the marine
    environment.
   There are animal activists who claim that Greeks don't care about animals
    and who send out pictures of suffering puppies because it makes them feel
    like they are helping them. They tell people to boycott Greece as if that will
    make the plight of animals any better. But the people in Greece who are
    actually helping animals are those on the front lines, in the streets and
    neighbourhoods of Athens and in the villages and countryside and they
    need your support.
   These organizations below are doing what they can do help animals and to
    educate people in an effort to eliminate animal cruelty. They need
    volunteers and money so if you care about the plight of animals in Greece
    contact one or more of them.
                              Greenpeace
   The Greek branch of this worldwide organisation for environmental
    action can be contacted at its Athens offices on 210-380-6374/5 or
    210-384-0774 or through its website www.greenpeace.gr.




                      Hellenic Ornithological Society
   This organisation works with international birdlife organisations,
    aims to protect indigenous species and keep safe havens for
    migratory birds on their travels. Conducts research into, and
    provides data about, populations of wild birds. Call 210-822-7937.
                   Medasset
 Thisorganisation sets up conservation projects and
 awareness campaigns about all species of sea turtle
 and lobbies the government to formulate and enforce
 legislation to protect indigenous species. Call 210-
 361-3572 or e-mail medasset@hol.gr
ENVIRONMENTAL
   City problems (Katie Statiri)
   Recycling (Sylia Giakumaki)
   Forest fires (Tortzina Teza)
   Ozone layer (Eutihia Albanou)
   Our life without environmental problems
    (Eleana Koutsoubeli)
       Gas reduction
       It may take up to one year for one tree to fix the amount of CO2 found in 3 litres of gas, so:


      1.Windmill kits are inexpensive and a great source of electricity in windy areas. Solar
        energy, especially solar collectors for water heaters, is possible for most homes. Some
        companies will buy back excess electricity.
      2.Reduce the usage of refrigerants and   air-conditioners
      3.Charge batteries rather then throw them away
      4. Walk short distances rather than drive
      5. Use public transportation or carpool for long trips.
      6.Concider ditcing the car altogether
      7. Research biodiesel
      8.Research energy efficient, electric, hybrid and diesel engines when buying a new car,
    motorbike or scooter
Opt for reusable bags
Put a « No Junk Mail » sticker on your letterbox
Avoid food waste
Buy in bulk or in large-size packaging
Buy eco-rechargeable or refillable products
Drink tap water
Limit use of
the printer
Restrict printer usage
Start composting
Donate old clothing
Borrow or hire tools
Repair goods and appliances
you would never want your house
to be so dirty then why you do it to
your kids??? 
     Κάντε κλικ εδώ για την
 Invest inεισαγωγή τίτλου
          green jobs and clean energy
Κάντε κλικ εδώ για την εισαγωγή
διάρθρωσης clean energy industries,
 1:Investing in
 such as wind and solar, energy efficiency
 programs and retooling manufacturing
 plants lead us out of crisis and into a new
 clean energy economy.
       Κάντε κλικ εδώ για την
          εισαγωγή τίτλου
Drive smarter cars
  Κάντε κλικ εδώ για την εισαγωγή
  διάρθρωσης
2:Breaking our oil addiction and retooling
plants to manufacture the fuel-efficient
cars that consumers are demanding,
including hybrids and plug-in hybrids.
      Κάντε κλικ εδώ για την
           εισαγωγή τίτλου
Create green homes and buildings
  Κάντε κλικ εδώ για την εισαγωγή
3:New buildings should meet strong new
  διάρθρωσης
energy-efficiency standards that maximize
energy savings. And existing homes and
commercial spaces can be retrofitted to save
energy by weatherizing and installing energy
efficient heating, cooling and lighting systems.
Lets take a break!!!
      Biomass
 fluorescent lamps

    Photovoltaic
    Water heaters
    Biomass, as a renewable

    energy source is biological
    material from living, or
    recently living organisms. As
    an energy source, biomass
    can either be used directly, or
    converted into other energy
    products such as biofuel.
   In the first sense, biomass is plant
    matter used to generate electricity with
    steam turbines & gasifiers or produce
    heat, usually by direct combustion. .
    Examples include forest residues (such
    as dead trees, branches and tree
    stumps, yard clippings, wood chips
    and even municipal solid waste. In the
    second sense, biomass includes plant
    or animal matter that can be converted
    into fibers or other industrial
    chemicals such as biofuels. Industrial
    biomass can be grown from numerous
    types of plants, including miscanthus ,
    switchgrass, hemp, corn, poplar,
    willow, sorghum, sugarcane, and a
    variety of tree species, ranging from
    eucalyptus to oil palm.
   These are processes in which
    heat is the dominant
    mechanism to convert the
    biomass into another
    chemical form. The basic
    alternatives of combustion,
    torrefaction, pyrolysis, and
    gasification are separated
    principally by the extent to
    which the chemicalinvolved
    are allowed to proceed
    (mainly controlled by the
    availability of oxygen and
    conversion temperature).
    reactions ivlolved are
    allowed to be proceed
    (mainly controlled by the
    availability of oxygen and
    conversion temperature).
    Chemical conversion
    A range of chemical processes may be used to
     convert biomass into other forms, such as to
     produce a fuel that is more conveniently used,
     transported or stored, or to exploit some property
     of the process itself.
    Biochemical conversion
    As biomass is a natural material, many highly
     efficient biochemical processes have developed in
     nature to break down the molecules of which
     biomass is composed, and many of these
     biochemical conversion processes can be
     harnessed.
   The incandescent lamp comprises a thin metal
    thread, heavy, usually tungsten , wrapped in
    spirals. This is claimed by its edges welded to
    two thicker wires in which the voltage which
    sets the electric charges in motion which forces
    the thread to illuminate the heating. When the
    length of the filament is larger than 2 cm it is
    supported and intermediate non-electrified
    wires in a radial arrangement. This structure is
    enclosed in a glass ampoule spherical or
    elliptical low-pressure gas.
   Main causes of damage and "death" of the incandescent
    lamp is the sublimation of the tungsten filament
    thickness progressively decreases until it cut to the
    point where it is weakest. The sublimation is also the
    reason to prevent the increase of temperature. Other
    major causes of reduced life are:
   1. Increases in voltage, an increase of approximately 5%
    reduction in life observed 30%.
   2. Switching on the lamps thereof, that means that in 1
    / 10 sec is power almost 12 times more than normal.
    This is because the resistance presented by the
    tungsten filament is approximately 12 times lower
    when it is cold compared to the resistance shows that
    when it is hot, that is in operation
   The use of such common bulbs today, although
    a low efficiency, is very broad due to the very
    low cost. The fluorescent lamp is a gas
    discharge lamp that uses electricity to stimulate
    pressure mercury . The lamps are available in
    various shapes and sizes, with the most
    common of these tube (used for lighting offices
    and shops) and compact fluorescent lamp
    (used for lighting homes). Manufactured in
    standard lengths, the straight, and diameters,
    circular and grid voltages 220 V and 110 V.
   Photovoltaic (PV) is a method of generating
    electrical power by converting solar radiation
    into direct current electricity using
    semiconductors that exhibit the photovoltaic
    effect. Photovoltaic power generation employs
    solar panels composed of a number of solar
    cells containing a photovoltaic material.
    Materials presently used for photovoltaic
    include monocrystalline silicon, polycrystalline
    silicon, amorphous silicon, cadmium telluride,
    and copper indium gallium selenide/sulfide.
   The photovoltaic effect is the creation of a
    voltage (or a corresponding electric current) in
    a material upon exposure to light. Though the
    photovoltaic effect is directly related to the
    photoelectric effect, the two processes are
    different and should be distinguished.[

   The photovoltaic effect was first observed by
    Alexandre-Edmond Becquerel in 1839.
   Thanks for watching …..

   Iliana Chandra
   Penny Stamatelatou
   Marianna Kopsahili
   Christiana Tsantrizou

				
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posted:11/26/2012
language:English
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