Saturday, March 31, 2007

Bee (trigona minima)

( Original Source : Wikipedia Encyclopedia, Photo Source : Google Images )

Bees are flying insects, closely related to wasps and ants. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila. There are slightly fewer than 20,000 known species of bees, though many are undescribed and the actual number is probably higher. They are found on every continent except Antarctica.
Many species of bees are poorly known. The smallest bee is the dwarf bee (Trigona minima) and it is about 2.1 mm (5/64") long. The largest bee in the world is Megachile pluto, which can be as large as 39 mm (1.5"). The most common type of bee in the Northern Hemisphere are the many species of Halictidae, or sweat bees, though this may come as a surprise to people, as they are small and often mistaken for wasps or flies. The most well-known bee species is the Western honey bee, which, as its name suggests, produces honey, as do a few other types of bee. Human control of this species is known as beekeeping or apiculture.
Bees are adapted for feeding on nectar and pollen, the former primarily as an energy source, and the latter primarily for protein and other nutrients. Most pollen is used as food for larvae.

Bees have a long proboscis that enables them to obtain the nectar from flowers. Bees have antennae almost universally made up of thirteen segments in males and twelve in females, as is typical for the superfamily. They all have two pairs of wings, the back pair being the smaller of the two; in a very few species, one sex or caste has relatively short wings that make flight difficult or impossible, but none are wingless.

Pollination
Bees play an important role in pollinating flowering plants, and are the major type of pollinators in ecosystems that contain flowering plants. Bees may focus on gathering nectar or on gathering pollen, depending on their greater need at the time. Bees gathering nectar may accomplish pollination, but bees that are deliberately gathering pollen are more efficient pollinators. It is estimated that one third of the human food supply depends on insect pollination, most of this accomplished by bees.


Most bees are fuzzy and carry an electrostatic charge, thus aiding in the adherence of pollen. Female bees periodically stop foraging and groom themselves to pack the pollen into the scopa, which is on the legs in most bees, and on the ventral abdomen on others, and modified into specialized pollen baskets on the legs of honey bees and their relatives. Many bees are opportunistic foragers, and will gather pollen from a variety of plants, but many others are oligolectic, gathering pollen from only one or a few types of plant. A small number of plants produce nutritious floral oils rather than pollen, which are gathered and used by oligolectic bees. One small subgroup of stingless bees (called "vulture bees") is specialized to feed on carrion, and these are the only bees that do not use plant products as food. Pollen and nectar are usually combined together to form a "provision mass", which is often soupy, but can be firm. It is formed into various shapes (typically spheroid), and stored in a small chamber (a "cell"), with the egg deposited on the mass. The cell is typically sealed after the egg is laid, and the adult and larva never interact directly (a system called "mass provisioning").


Bees are extremely important as pollinators in agriculture, especially the domesticated Western honey bee, with contract pollination having overtaken the role of honey production for beekeepers in many countries. Monoculture and pollinator decline have increasingly caused honey bee keepers to become migratory so that bees can be concentrated in areas of pollination need at the appropriate season. Many other species of bees are increasingly cultured and used to meet the agricultural pollination need. Bees also play a major, though not always understood, role in providing food for birds and wildlife. Many of these bees survive in refuge in wild areas away from agricultural spraying, only to be poisoned in massive spray programs for mosquitoes, gypsy moths, or other pest insects.

Visiting flowers is a dangerous occupation with high mortality rates. Many assassin bugs and crab spiders hide in flowers to capture unwary bees. Others are lost to birds in flight. Insecticides used on blooming plants can kill large numbers of bees, both by direct poisoning and by contamination of their food supply. A honey bee queen may lay 2000 eggs per day during spring buildup, but she also must lay 1000 to 1500 eggs per day during the foraging season, simply to replace daily casualties. The population value of bees depends partly on the individual efficiency of the bees, but also on the population itself. Thus, while bumblebees have been found to be about ten times more efficient pollinators on cucurbits, the total efficiency of a colony of honey bees is much greater, due to greater numbers. Likewise, during early spring orchard blossoms, bumblebee populations are limited to only a few queens, thus they are not significant pollinators of early fruit.

Evolution
Bees, like ants, are essentially a highly specialized form of wasp. The ancestors of bees were wasps in the family Crabronidae, and therefore predators of other insects. The switch from insect prey to pollen may have resulted from the consumption of prey insects that were flower visitors and were partially covered with pollen when they were fed to the wasp larvae. This same evolutionary scenario has also occurred within the vespoid wasps, where the group known as "pollen wasps" also evolved from predatory ancestors. The oldest bee fossil, of the genus Melittosphex, is 100 million years old and supports the theory that bees evolved from wasps, and subsequently evolved alongside flowers. The earliest animal pollinated flowers were pollinated by insects such as beetles, so the syndrome of insect pollination was well established before bees first appeared. The novelty is that bees are specialized as pollination agents, with behavioral and physical modifications that specifically enhance pollination, and are much more efficient at the task than beetles, flies, butterflies, pollen wasps, or any other pollinating insect. The appearance of such floral specialists is believed to have driven the adaptive radiation of the angiosperms, and, in turn, the bees themselves.

Friday, March 23, 2007

Harry Potter and the Order of the Phoenix

( Original Source : Yahoo! Movies )

As his fifth year at Hogwarts School of Witchcraft and Wizardry approaches, 15-year-old Harry Potter is in full-blown adolescence, complete with regular outbursts of rage, a nearly debilitating crush, and the blooming of a powerful sense of rebellion. It's been yet another infuriating and boring summer with the despicable Dursleys, this time with minimal contact from our hero's non-Muggle friends from school. Harry is feeling especially edgy at the lack of news from the magic world, wondering when the freshly revived evil Lord Voldemort will strike. Returning to Hogwarts will be a relief--or will it?

Production Status : In Production/Awaiting Release
Genres : Action/Adventure, Kids/Family, Romance, Science Fiction/Fantasy and Adaptation
Release Date : July 13th, 2007 (wide)
Distributors : Warner Bros. Pictures Distribution
Production Co. : Wigram Productions, 1492 Pictures, Heyday Films
Studios : Warner Bros. Pictures, Inc.
Produced in : United Kingdom

Thursday, March 22, 2007

Nagarjuna Sagar Dam in India

( Original Source : Andhra Pradesh Tourism Website )

There would be very few modern constructions you will come across that evoke such a response. A feeling of awe and significance overcomes you when you lay eyes upon the Nagarjuna Sagar Dam for the first time. Its sheer size and magnitude leaves you breathless and astounded. As the tallest and largest masonry dam in the world, truly stands as one of the wonders of engineering excellence. Stretching across the mighty river Krishna, the barrage also has another distinction to its credit - it has created one of the world's largest man-made lake! The reservoir is a vital source of irrigation for vast tracts of the surroundings region. The two left and right canals, called Bahadur Canal and Jawahar canal respectively, cater to the watering needs of a very large area of the state. Successfully transforming a barren, thirsty land into a lush verdant landscape with acres and acres of green fields swaying in the breeze as far as the eye can see. Naturally, it has played a leading role in helping the state of Andhra Pradesh emerge as' the Rice Bowl of India'.

Significantly, the creation of this lake has submerged the excavations that were carried out here in 1926 which unearthed three historical sites- Dhanyakataka, capital of the Satavahanas; Sriparvata, Vijayapuri, capital of the Ikshvakus and a Buddist civilization that thrived here in the third and fourth centuries B.C. What is of special interest to historians is the fact that the excavations also revealed the existence of Brahmanical temples here which indicates that Hinduism and Buddhism flourished together in peaceful co-existence.

Wolverine (gulo gulo)

( Original Source : Nationalgeographic Website )

The wolverine is a powerful animal that resembles a small bear but is actually the largest member of the weasel family. These tough animals are solitary, and they need a lot of room to roam. Individual wolverines may travel 15 miles (24 kilometers) in a day in search of food. Because of these habitat requirements, wolverines frequent remote boreal forests, taiga, and tundra in the northern latitudes of Europe, Asia, and North America. Wolverines eat a bit of vegetarian fare, like plants and berries, in the summer season, but this does not make up a major part of their diet—they are tenacious predators with a taste for meat. Wolverines easily dispatch smaller prey, such as rabbits and rodents, but may even attack animals many times their size, such as caribou, if the prey appears to be weak or injured. These opportunistic eaters also feed on carrion—the corpses of larger mammals, such as elk, deer, and caribou. Such finds sustain them in winter when other prey may be thinner on the ground, though they have also been known to dig into burrows and eat hibernating mammals.

Males scent-mark their territories, but they share them with several females and are believed to be polygamous. Females den in the snow or under similar cover to give birth to two or three young each late winter or early spring. Kits sometimes live with their mother until they reach their own reproductive age—about two years old. Wolverines sport heavy, attractive fur that once made them a prime trapper's target in North America. Their fur was used to line parkas, though this practice is far less common today and the animals are protected in many areas.

Type: Mammal
Diet: Omnivore
Average lifespan in the wild: 7 to 12 years
Size: Head and body, 26 to 34 in (66 to 86 cm); Tail, 7 to 10 in (18 to 25 cm)
Weight: 24 to 40 lbs (11 to 18 kg)
Size relative to a 6 ft (2 m) man

Solar Energy

Renewable energy sources Mass production of electricity from renewable energy flows requires technology that harnesses the power of natural phenomena such as sunlight, wind, tides and geothermal heat. Each of these sources has unique characteristics which influence how and where they are used.

The majority of renewable energy technologies are directly or indirectly powered by the Sun. The Earth-Atmosphere system is in equilibrium such that heat radiation into space is equal to incoming solar radiation, the resulting level of energy within the Earth-Atmosphere system can roughly be described as the Earth's "climate". The hydrosphere (water) absorbs a major fraction of the incoming radiation. Most radiation is absorbed at low latitudes around the equator, but this energy is dissipated around the globe in the form of winds and ocean currents. Wave motion may play a role in the process of transferring mechanical energy between the atmosphere and the ocean through wind stress (Sorensen, 2004). Solar energy is also responsible for the distribution of precipitation which is tapped by hydroelectric projects, and for the growth of plants used to create biofuels. In this context, "solar energy" refers to energy that is collected from sunlight. However, most fossil and renewable energy sources are ultimately derived from "solar energy," so some ascribe much broader meanings to the term.
Solar energy can be applied in many ways, including to : 1. Generate electricity using photovoltaic solar cells. 2. Generate electricity using concentrated solar power. 3. Generate electricity by heating trapped air which rotates turbines in a Solar updraft tower. 4. Heat buildings, directly. Careful positioning of windows and use of brises soleil can maximise inflow of light at the times it is most needed, heating the building while preventing overheating during midday and summer. 5. Heat foodstuffs, through solar ovens. 6. Heat water or air for domestic hot water and space heating needs using solar-thermal panels. 7. Heat and cool air through use of solar chimneys. 8. Generate electricity using Space Solar Power Satellite in geostationary orbit and beam it down via microwaves.
The sun does not provide constant energy to any spot on the Earth, so its uninterrupted use on Earth requires a means for energy storage. This is typically accomplished by battery storage. However, battery storage implies energy losses. Some homeowners use a grid-connected solar system that feeds energy to the grid during the day and draw energy from the grid at night; this way no energy is expended for storage. Batteries provide direct current (DC), whereas most household appliances run off alternating current (AC). Conversion from DC to AC leads to some energy loss.
Advantages from solar energy sources include the inexhaustible supply of energy and zero emissions of greenhouse gas and air pollutants. Shortcomings include, depending on application : 1. Economic competitiveness with conventional energy conversion 2. Intermittency; it is not available at night or during heavy cloud cover. 3. For photovoltaics (solar-electric), the current generated is only of DC type, and must be converted if transmission over the standard AC grid is needed. ( Original Source : Wikipedia Encyclopedia, Photo Source : Google Images )

Batik

( Original Source : Wikipedia Encyclopedia, Photo Source : Google Images )

Batik or batique is an Indonesian-Malay word and refers to a generic wax-resist dyeing technique used on textile. The word originates from Malay word for dot or point, "titik" and the Javanese word "amba", meaning ”to write”. The island of Java in Indonesia is famous for batik. Melted wax is applied to cloth before being dipped in dye. Wherever the wax has seeped through the fabric, the dye will not penetrate. Sometimes several colors are used, with a series of dyeing, drying and waxing steps. Thin wax lines are made with a tjanting needle, wooden handled tool with a tiny metal cup with a tiny spout, out of which the wax seeps. Other methods of applying the wax onto the fabric include pouring the liquid wax, painting the wax on with a brush, and applying the hot wax to precarved wooden or metal wire block and stamping the fabric.

After the last dyeing, the fabric is hung up to dry. Then it is dipped in a solvent to dissolve the wax, or ironed between paper towels or newspapers to absorb the wax and reveal the deep rich colors and the fine crinkle lines that give batik its character. The invention of the copper block or tjap developed by the Javanese in the 20th century revolutionised batik production. It became possible to make high quality designs and intricate patterns much faster than one could possibly do by hand-painting. As compared to Indonesian batik, which are mystic-influenced and carry illustrations of animals and people, Malaysian batik have brighter hues and more versatile patterns.

Tulip

( Original Source : Wikipedia Encyclopedia, Photo Source : Google Images )

Tulip (Tulipa) is a genus of about 100 species of flowering plants in the family Liliaceae. They are native to southern Europe, north Africa, and Asia from Anatolia and Iran (where the flower is suggested on the nation's flag) east to northeast China and Japan. The centre of diversity of the genus is in the Pamir and Hindu Kush mountains and the steppes of Kazakhstan.


They are perennial bulbous plants growing to 10–70 centimetres (4–27 in) tall, with a small number of strap-shaped, waxy-textured, usually glaucous green leaves and large flowers with six tepals. The fruit is a dry capsule containing numerous flat disc-shaped seeds.


Cultivation
Tulips cannot be grown in the open in tropical climates, as they require a cold winter season to grow successfully. Manipulation of the tulip's growing temperature can, however, allow growers to "force" tulips to flower earlier than they normally would.

Some historical cultivars have had a striped, "feathered", "flamed", or variegated flower, as in the illustration below. While some modern varieties also display multicoloured patterns, this results from a natural change in the upper and lower layers of pigment in the tulip flower. Historical variegated varieties - such as those admired in the Dutch tulipomania gained their delicately feathered patterns from an infection with Tulip Breaking potyvirus. The mosaic virus is carried by green peach aphids, Myzus persicae, an insect common in European gardens of the seventeenth century, in which peach trees were often a prominent feature. While the virus produces fantastically beautiful flowers, it also causes the plant to sicken and die slowly. Today, it has been almost completely eradicated from growers' fields. The Black Tulip was the title of a historical romance by Alexandre Dumas (1850), in which the city of Haarlem has a reward outstanding for the first grower who can produce a truly black tulip. This fascination with growing a black tulip, a biologically impossible task, was historically accurate to the tulipomania in which the novel is set.

Tulips can be grown in either of two ways: through offsets or seed. Being genetic clones of the parent plant, offsets are the only way to enlarge the stock of a given tulip cultivar. By contrast, tulips do not come true from seed; the mixing of genes between parent tulips is very unpredictable. A tulip grown from seed will usually bear only a passing resemblance to the flower from which the seeds were taken. This makes for great potential in breeding new tulip flowers, and great variation in the wild. However, tulip growers must be patient: offsets often take at least a year to grow to sufficient size to flower, and a tulip grown from seed will not flower for anywhere between five and seven years after planting. "Broken" tulips (tulips affected by the mosaic virus) will occasionally revert to plain "breeder" colouring, but usually maintain their colourful, infected state when grown from offsets.

Introduction to Western Europe
It is unclear who first brought the flower to northwest Europe. The most widely accepted story is that of Oghier Ghislain de Busbecq, Ambassador from Ferdinand I to Suleyman the Magnificent of the Ottoman Empire in 1554. He remarks in a letter upon seeing "an abundance of flowers everywhere; Narcissus, hyacinths, and those which in Turkish Lale, much to our astonishment, because it was almost midwinter, a season unfriendly to flowers" (see Busbecq, qtd. in Blunt, 7). By 1559, an account was given by Conrad Gessner of seeing tulips flowering in the garden of Councilor Herwart in Augsburg, Bavaria. Due to the very nature of the tulip's growing cycle, if the bulbs are to be removed from the ground, it generally occurs in June, and they must be replanted again by September to endure the winter, Busbecq's account of the supposed first sighting of tulips by a European is likely spurious. While possible, it is doubtful that Busbecq could successfully have had the tulip bulbs removed, shipped, and replanted between his first sighting of them in March 1558 and Gessner's description in 1559. After introduction of the Tulip to Europe, it is believed to gain much popularity and shown as a sign of abundance and indulgence in the Ottoman Empire, The era which the Empire was wealthiest is called the Tulip Era, in Turkish Lale Devri.

Another oft-quoted account is that of Lopo Vaz de Sampayo, governor of the Portuguese possessions in India. Having been brought home in disgrace after usurping his position from the rightful governor, Sampayo supposedly took tulip bulbs with him from Sri Lanka. This tale too, however, does not hold up to scrutiny; tulips do not occur in Sri Lanka, and the island itself is far from the route Sampayo's ships should have taken.

Regardless of how the flower originally arrived in Europe, its popularity soared quickly. Charles de L'Ecluse (Clusius) is responsible for much of the spread of tulip bulbs in the final years of the sixteenth century. He was the author of the first major work on tulips, finally completed in 1592. Clusius had already begun to note and remark upon the diseased variations in colour that made the tulip so admired. His taste for tulips quickly spread to others. While occupying a chair in the medical faculty of the University of Leiden, Clusius planted both a teaching garden and his own private plot with tulip bulbs. In 1596 and 1598, however, Clusius suffered thefts from his garden, with over a hundred bulbs stolen in a single raid. Between 1634 and 1637, the early enthusiasm for the new flowers triggered a speculative frenzy now known as the tulip mania and tulip bulbs were then considered a form of currency. The Netherlands and tulips are still associated with one another. The term 'Dutch tulips' is often used for the cultivated forms.

Boomerang

( Original Source : Wikipedia Encyclopedia, Photo Source : Google Images )

A boomerang is a simple wooden implement used for various purposes. It is primarily attributed to Australian Aborigines, but other forms are found amongst peoples of North East Africa, Arizona Indians and in India. It comes in many shapes and sizes depending on its geographic/tribal origins and intended function. The most recognizable type is the returning boomerang, a kind of Throwing Stick that, when thrown correctly, travels in a curved path and returns to its point of origin. Other types of boomerang are of the non-returning sort, and indeed, some are not thrown at all but are used in hand-to-hand combat by Aboriginal people Boomerangs can be variously used as hunting weapons, percussive musical instruments, battle clubs, fire-starters, decoys for hunting waterfowl, and as recreational playthings. The smallest boomerang may be less than 10 cm from tip-to-tip, and the largest over 2 meters in length. Tribal boomerangs may be incised and/or painted with designs meaningful to its maker. Most boomerangs seen today are of the tourist or competition sort, and are almost invariably of the returning type.

History
Boomerang-like devices, including hunting sticks, have been used all over the world for hunting, religious and recreational activities. Their origin is still not fully clear. Research has shown that ancient tribes in Europe used special throwing axes. Also, in ancient Egypt a special type of stick was exclusively used by the pharaohs for hunting birds. However, the world famous "country of the boomerang" is Australia, where the Australian Aborigines have used both boomerangs and hunting sticks for many thousands of years. The name of the boomerang comes from the Indigenous Australian Turuwal tribe of Aborigines who lived south of Sydney, Australia.

Today, boomerangs are most used as sporting items. There are different types of throwing contests: accuracy of return; aussie round; trick catch; maximum time aloft; fast catch; and endurance (See below). The modern sport boomerang (often referred to as a 'boom' or 'rang'), is made of Finnish birch plywood, hardwood, plastic or composite materials and comes in many different shapes and colors. Most sport boomerangs typically weigh less than 100 grams, with MTA boomerangs (boomerangs used for the maximum time aloft event) often under 25 grams.


Design
A returning boomerang is an airfoil. Though it is not a requirement that the boomerang be in its traditional shape, it is usually flat. A falling boomerang starts spinning and most then fall in a spiral. When the boomerang is thrown with high spin, the wings produce lift. Larger boomerangs are used in hunting, thus they drop on the ground after striking the target. Smaller ones are used in sport, and are the only boomerangs that return to the thrower. Because of its rapid spinning, a boomerang flies in a curve rather than a straight line. When thrown correctly, a boomerang returns to its starting point.




Now in more detail
Returning boomerangs consist of two or more arms or wings, connected at an angle. Each wing is shaped as an airfoil, air travels faster over one surface of an airfoil than the other, as the air is accelerated due to the curvature, thus creating lift, along what is roughly a plane which intersects the airfoil at a near right angle along the long axis of the wing.

These wings are set so that the lift created by each wing opposes the lift of the other, but at an angle such that the flight pattern is constantly shifted as the forces of lift, drag, speed, rotational inertia etc. 'attempt' to reach equilibrium, see Boomerang engineer.

This is what makes the boomerang 'return gracefully to the thrower, fluttering to a stop in his hand'... when thrown correctly. This is also what makes the boomerang 'rocket straight up into the air before plunging to its shattered doom'... when thrown incorrectly. With the exception of long-distance boomerangs, they should not be thrown sidearm or like a frisbee, but rather throw with the long axis of the wings rotating in an almost-vertical plane.

Fast Catch boomerangs usually have three symmetrical wings (in the planform view), whereas a Long Distance boomerang is most often shaped very similar to a question mark. Maximum Time Aloft boomerangs have one wing considerably longer than the other. This feature, along with carefully executed bends and twists in the wings, help to set up an 'auto-rotation' effect to maximize the boomerang's hover-time in descending from its highest point in the flight.

Basic throwing instructions
A right-handed boomerang circles towards the left, a left-handed boomerang circles towards the right. Most sport boomerangs are in the range of 2.5 to about 4 ounces. The range on most of these is between 25 - 40 yards (or meters)
A right or left handed boomerang can be thrown with either hand, but the flight direction will depend upon the boomerang, not the thrower. Throwing a boomerang with the wrong handedness requires a throwing motion that will feel awkward to many throwers. Beginners should thus take care to get a boomerang with the right handedness.

Grasp one wing of the boomerang nearly vertically so that the other wing points forward and the flat side is away from you. The other way works also, but this way is usually easier to learn. Holding the tip by just the end between your thumb and one or two fingers, launch the boomerang forward quickly while trying more for spin than for very much force.

The boomerang should flatten out on its own and arc around, sometimes coming to rest a little in front of the thrower or behind the thrower, but ideally it should hover gently and allow the thrower to catch it as a sort of "boomerang sandwich" between the thrower's hands.

One should not throw a returning boomerang level, like a flying disc. The boomerang will turn in the direction of the top of its airfoils, so if that direction happens to be up rather than to the side it may fly high enough that the landing causes damage to the boomerang or whatever it lands on.

Friday, March 2, 2007

Sakura

Sakura (Japanese kanji & Chinese character : 桜 or 櫻; hiragana : さくら; katakana : サクラ) is the Japanese name for ornamental cherry trees, Prunus serrulata, and their blossoms. Cherry fruit (known as sakuranbo) come from a different species of tree. Sakura, a well-known and ubiquitous symbol of Japan, are represented on all manner of consumer goods, including kimono, stationery, and dishware. Cherry blossoms are an enduring metaphor for the ephemeral nature of life, and as such are frequently depicted in art. There is at least one popular folk song, originally meant for the shakuhachi (bamboo flute), titled "Sakura", as well as a number of pop songs. "Sakura" is also a common Japanese female name. Sakura is indigenous to the Himalayas and east Asia. Some trees can be found in China and Korea but the largest number and variety of sakura, more than 305 species, can be seen in Japan. Many of them were artificially hybridized or grafted by the Japanese many centuries ago. "On the other hand, in China, cherry blossom is the symbol of feminine dominance, female beauty and sexuality. Additionally, the cherry blossom is the Chinese symbol of feminine principle and it also symbolizes love in the language of herbs. Interestingly, cherry blossom is the flower of the April in China, whereas in Japan, it is wisteria." Spring flowers of Japan Japan's most beloved variety is the Somei Yoshino. Its flowers are nearly pure white, tinged with the palest pink, especially near the stem. The flowers bloom, and usually fall (or "scatter", 散る [chiru], in Japanese) within a week, before the leaves come out. Therefore, the trees look nearly white from top to bottom. The variety takes its name from the village of Somei (now part of Toshima in Tokyo). It was developed in the mid- to late-19th century at the end of the Edo period and the beginning of the Meiji period. The Somei Yoshino is so widely associated with cherry blossoms that jidaigeki and other works of fiction often depict the variety in the Edo period or earlier; such depictions are anachronisms.

Other categories include yamazakura, yaezakura, and shidarezakura. The yaezakura have large flowers, thick with rich pink petals. The shidarezakura, or weeping cherry, has branches that fall like those of a weeping willow, bearing cascades of pink flowers. Annually, the Japanese Meteorological Agency and general public track the sakura zensen, or Cherry-Blossom Front. Nightly forecasts follow the weather segment of news programs. The blossoming begins in Okinawa in January, and typically reaches Kyoto and Tokyo at the end of March or the beginning of April. Then it proceeds north, arriving in Hokkaidō a few weeks later. Japanese pay close attention to these forecasts. They will go to parks, shrines and temples with family and friends and hold a "flower viewing party" known as hanami (花見). Hanami festivals celebrate the beauty of sakura, and for many, it is a chance to relax and enjoy the beautiful view. Hanami custom in Japan dates back to many centuries ago. It is witten in Nihon Shoki (日本書紀) that the Hanami festival were already held in the 3rd century.
Most Japanese schools and public buildings have sakura trees outside of them. Since the fiscal and school year both begin in April, in many parts of Honshū, the first day of work or school will coincide with the cherry blossom season. The sakura has always been a symbol of ephemeral beauty in Japan and closely associated with samurai or bushi. Life was considered brief and beautiful, much like a cherry blossom. This theme remains alive today, seen often in pop culture (specifically manga and anime). Music also works with the theme. For example, the band Kagrra, that often associates sakura to its songs and live shows ambience.
( Original Source : Wikipedia Encyclopedia, Photo Source : Google Images )

Thursday, March 1, 2007

Greenhouse

A greenhouse (also called a glasshouse or hothouse) is a building where plants are cultivated. Explanation A greenhouse is structure with a glass or plastic roof and frequently glass or plastic walls; it heats up because incoming solar radiation from the sun warms plants, soil, and other things inside the building. Air warmed by the heat from hot interior surfaces is retained in the building by the roof and wall. These structures range in size from small sheds to very large buildings. The glass used for a greenhouse works as a selective transmission medium for different spectral frequencies, and its effect is to trap energy within the greenhouse, which heats both the plants and the ground inside it. This warms the air near the ground, and this air is prevented from rising and flowing away, in addition to the fact that infrared radiation cannot pass through the greenhouse glass. This can be demonstrated by opening a small window near the roof of a greenhouse: the temperature drops considerably. This principle is the basis of the autovent automatic cooling system. Greenhouses thus work by trapping electromagnetic radiation and preventing convection. Miniature greenhouses are known as a Cold frame. Uses Greenhouse effects are often used for growing flowers, vegetables, fruits, and tobacco plants. Bumblebees are the pollinators of choice for most greenhouse pollination, although other types of bees have been used, as well as artificial pollination. Besides tobacco, many vegetables and flowers are grown in greenhouses in late winter and early spring, then transplanted outside as the weather warms. Started plants are usually available for gardeners in farmers' markets at transplanting time.

The closed environment of a greenhouse has its own unique requirements, compared with outdoor production. Pests and diseases, and extremes of heat and humidity, have to be controlled, and irrigation is necessary to provide water. Significant inputs of heat and light may be required, particularly with winter production of warm-weather vegetables. Special greenhouse varieties of certain crops, like tomatoes, are generally used for commercial production.
Greenhouses are increasingly important in the food supply of high latitude countries. The largest greenhouse complex in the world is at Leamington, Ontario (close to Canada's most southern point) where about 200 acres (0.8 km²) of tomatoes are entirely grown under glass. Greenhouses protect crops from too much heat or cold, shield plants from dust storms and blizzards, and help to keep out pests. Light and temperature control allows greenhouses to turn unarable land into arable land. Greenhouses can feed starving nations where crops can't survive in the harsh deserts and arctic wastes. Hydroponics can be used in greenhouses as well to make the most use of the interior space.. History The idea of growing plants in environmentally controlled areas has existed since Roman times. Doctors for the Roman emperor Tiberius prescribed him a cucumber daily. The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year. Cucumbers were planted in wheeled carts which were put in the sun daily, then taken inside to keep them warm at night. The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as "specularia" or with sheets of mica. (Pliny the Elder and Columella).
The first modern greenhouses were built in Italy in the sixteenth century to house the exotic plants that explorers brought back from the tropics. They were originally called giardini botanici (botanical gardens). The concept of greenhouses soon spread to the Netherlands and then England, along with the plants. Some of these early attempts required enormous amounts of work to close up at night or to winterize. There were serious problems with providing adequate and balanced heat in these early greenhouses. Jules Charles, a French botanist, is often credited with building the first practical modern greenhouse in Leiden, Holland to grow medicinal tropical plants.
Originally on the estates of the rich, with the growth of the science of botany greenhouses spread to the universities. The British some times called their greenhouses conservatories, since they conserved the plants. The French called their first greenhouses orangeries, since they were used to protect orange trees from freezing. As pineapples became popular pineries were built. Experimentation with the design of greenhouses continued during the Seventeenth Century in Europe as technology produced better glass and construction techniques improved. The greenhouse at the Palace of Versailles was an example of their size and elaborateness; it was more than 500 feet long, 42 feet wide, and 45 feet high.
In the nineteenth Century the largest greenhouses were built. The conservatory at Kew Gardens in England is a prime example of the Victorian greenhouse. Although intended for both horticultural and non-horticultural exhibition these included London's Crystal Palace, the New York Crystal Palace and Munich’s Glaspalast. Joseph Paxton, who had experimented with glass and iron in the creation of large greenhouses as the head gardener at Chatsworth, in Derbyshire, working for the Duke of Devonshire, designed and built the first, London's Crystal Palace. In Japan, the first greenhouse was built in 1880 by Samuel Cocking, a British merchant who exported herbs. In the Twentieth Century the geodesic dome was added to the many types of greenhouses. ( Original Source : Wikipedia Encyclopedia, Photo Source : Google Images )