tsunami. WHAT CAUSES A TSUNAMI? Tsunamis may also be caused by underwater landslides or volcanic eruptions. They may even be launched, as they frequently were in Earth’s ancient past, by the impact of a large meteorite plunging into an ocean. TSUNAMI Can race up to 805 kilometers an hour. At that pace, they can cross the entire expanse of the Pacific Ocean in less than a day. And their long wavelengths mean they lose very little energy along the way. In deep ocean, tsunami waves may appear only a foot or so high. But as they approach shoreline and enter shallower water they slow down and begin to grow in energy and height. WHAT HAPPENS WHEN IT HITS LAND? • A tsunami’s trough, the low point beneath the wave’s crest, often reaches shore first. When it does, it produces a vacuum effect that sucks
centimeter) Hale Telescope. Caltech astronomer Avishay Gal-Yam had two hours before the supernova would dip too low in the sky for the telescope to see it. Still more luminous than a billion suns, the supernova outshone the combined light from all the stars in its home galaxy, glowing white-hot from the radioactive decay of unstable nickel atoms forged in the explosion. Gal-Yam pointed to a computer screen showing a squiggly line--the glow broken down into its component colors, or wavelengths. Each dip in the line represented a wavelength of light absorbed by a different element--silicon, cobalt, calcium, iron--in the debris of the star. Destruction and creation were conjoined on the screen. The elements revealed there, like those from countless earlier supernovas, will eventually find their way into new stars and perhaps new planets, Gal-Yam said. He added: "I'm just really happy to be observing this."
Rainforests now cover less than 6% of Earth's land surface. AlpineCold, snowy, windy. In the summer average temperatures range from 10 to 15° C . In the winter the temperatures are below freezing. The winter season can last from October to May. The summer season may last from June to September. The temperatures in the Alpine biome can also change from warm to freezing in one day. Alpine animals have to deal with two types of problems: the cold and too much high UV wavelengths. 4. How are plants adapted to life in the biome? Tundra plants are small -- usually less than a foot high .The hairs on the stems of many tundra plants, such as the Arctic crocus, help to trap heat near the plant and act as protection from the wind. Plants adapted to the tundra have small waxy leaves to prevent the loss of precious water in this dry environment. Quick-Developing, Cup-Shaped Flowers Soil Not Needed for Growth
spektriosas, mis ei ole inimsilmale vahetult nähtav. 3 Kas valgele paberile kirjutatud punast kirja saab lugeda läbi punase klaasi vaadates? Ei saa, kuna osa valgust neeldub aines. 4 Miks on taevas sinine? Vihje: õhumolekulide elektronide omavõnkesagedused asuvad spektri sinakas-violetses piirkonnas. The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air.However, much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky. Whichever direction you look, some of this scattered blue light reaches you. 5 Miks Päike on tõustes ja loojudes punakas-oranz?
Gröönimaad väisav Põhja-Atlandi hoovus on globaalse termohaliinse tsirkulatsiooni osa. Fotosünteetiliselt aktiivne kiirgus Ligikaudu pool maa pinnani jõudvast valguskiirgusest on kasutatav fotosünteesil. Tegelikult kasutavad rohelised taimed sellest ainult 1-2%. Fotosünteetiliselt aktiivne kiirgus on inimsilmale nähtav kiirgus, lainepikkusega 400700 nm. Photosynthetically active radiation radiation visible to the human eye, wavelengths from 400 to 700 nm. 400 700 . Fotosünteetiliselt aktiivne kiirgus Kõige enam vajab taim violetset-sinist (380-470 nm) ja oranzi-punast (580-700 nm) spektriosa. Rohekas valgus peegeldub suures osas taime pinnalt. Seetõttu tajuvad meie silmad taimi rohelistena. Taimelehtedes muundatakse päikesevalgus fotosünteesi teel kompleksseteks energiarikasteks molekulideks. Hiljem, olgu siis taim ise või taimi toiduks kasutavad loomad, lõhustavad need molekulid selleks, et saada
Poikilotherms, for example, have a body temperature that is largely regulated and dependent on the temperature of the external environment. In contrast, homeotherms regulate their internal body temperature by expending metabolic energy. [2][86] [157] There is a relationship between light, primary production, and ecological energy budgets. Sunlight is the primary input of energy into the planet's ecosystems. Light is composed of electromagnetic energyof different wavelengths. Radiant energy from the sun generates heat, provides photons of light measured as active energy in the chemical reactions of life, and also acts as a catalyst for genetic mutation.[2][86][157] Plants, algae, and some bacteria absorb light and assimilate the energy throughphotosynthesis. Organisms capable of assimilating energy by photosynthesis or through inorganic fixation of H2S are autotrophs. Autotrophs--responsible for primary production--assimilate
ENVIRONMENTAL FATE In reviewing the fate of formaldehyde in the environment, it should be noted that the environmental factors that influence the bioavailability to humans of formaldehyde from contaminated air, water, or plant material have not been studied. Air Formaldehyde is removed from the atmosphere by direct photolysis and oxidation by photochemically produced hydroxyl radicals. Formaldehyde absorbs ultraviolet (UV) radiation at wavelengths of 360 nm and longer; therefore, it is capable of photolyzing in sunlight. A half-life of 6 hours has been measured for photolysis in simulated sunlight. There are two photolytic pathways, one producing H2 and CO, and the other producing H and HCO radicals. When the rates of these reactions are combined with estimates of actinic irradiance, the predicted half-life of formaldehyde due to photolysis in the lower atmosphere is 1.6 hours at a solar zenith angle of 40 degrees. Based
CE has one advantage over column chromatography processes. It is not necessary to wait until the last peak will cover the distance to the exit of the capillary, as after each analysis, the capillary is washed with a special solution and filled with new buffer. Because of the use of quartz capillary filled with buffer, onlineUV detection at wavelengths up to 200 nm is possible. The advantage of direct passage of a beam of light through the capillary is the fact that in this case there is no band broadening caused by the detector cell and inlet capillaries. This detection does not introduce additional dead space. Its drawback, however, is a small internal diameter of capillaries (from 25 to 100 micrometers)
Multimode & Singlemode Fibers Multimode & Singlemode fiber are the two types of fiber in common use. Both fibers are 125 microns in outside diameter - a micron is one one-millionth of a meter and 125 microns is 0.005 inches- a bit larger than the typical human hair. Multimode fiber has light traveling in the core in many rays, called modes. It has a bigger core (almost always 62.5 microns, but sometimes 50 microns ) and is used with LED sources at wavelengths of 850 and 1300 nm (see below!) for slower local area networks (LANs) and lasers at 850 and 1310 nm for networks running at gigabits per second or more. Singlemode fiber has a much smaller core, only about 9 microns, so that the light travels in only one ray. It is used for telephony and CATV with laser sources at 1300 and 1550 nm. Plastic Optical Fiber (POF) is large core ( about 1mm) fiber that can only be used for short, low speed networks.
8.1 Photovoltaic energy Photovoltaic energy is the conversion of sunlight into electricity. A photovoltaic cell, commonly called a solar cell or PV, is the technology used to convert solar energy directly into electrical power. A photovoltaic cell is a nonmechanical device usually made from silicon alloys. Sunlight is composed of photons, or particles of solar energy. These photons contain various amounts of energy corresponding to the different wavelengths of the solar spectrum. When photons strike a photovoltaic cell, they may be reflected, pass right through, or be absorbed. Only the absorbed photons provide energy to generate electricity. When enough sunlight (energy) is absorbed by the material (a semiconductor), electrons are dislodged from the material's atoms. Special treatment of the material surface during manufacturing makes the front surface of the cell more receptive to free electrons,
max 3 [3] 6. (a) (i) award both marks for correct answer 10 000 / 800 000 (× 100); 1.25 / 1.3 / 1(%); 2 (ii) R any reference to energy / light missing the plant reflected (off plant) / only certain wavelengths of light can be, absorbed / used; ora absorbed by / hits, non-photosynthetic parts; e.g. bark passes through leaf / misses chlorophyll / misses chloroplasts; some is heat that is used in evaporation / respiration; max 2 (iii) bacteria / named bacterium decomposer; (Nitrobacter, Nitrosomonas) 1 (iv) take the first 2 answers:
caused by the slow speed of the phototransistor. 62 Analog Interfacing to Embedded Microprocessors IR Problems Most slotted and reflective sensors use IR LEDs and phototransistors. This means that the response of the part may not be the same as it would be for something in the visible spectrum. Specifically, objects that are good at reflect- ing or blocking visible light may be less effective at IR wavelengths. IR is also susceptible to interference from fluorescent lights and sunlight. Figure 3.9 shows how driving the LED with a square wave signal can be combined with a filter to eliminate this type of interference. In this example, a source of ambient light causes the phototransistor to have a con- stant DC offset, and the signal is superimposed on a 60 Hz signal from fluorescent lighting. By passing the output of the transistor through a filter that is tuned to the
and Alocilja 2003). U.S.) has been developed for on-line mea- surements of moisture and fat content in ground meat. There exists also an on-line Microwave Spectrometry sensor for measuring the fat-to-lean ratio in Microwaves include waves with wavelengths pork middles (Keam Holden Ltd., New from 3m to 3mm. The corresponding Zealand). frequency range extends from 100MHz to 1mmGHz (Kent 2001). In the electromag- Near Infrared Spectroscopy netic spectrum, microwaves are located between radio waves at low frequencies and Near infrared (NIR) spectroscopy is a tech- infrared at higher frequencies (Fig. 25.1). nique that uses a portion of the electromag-
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