Thursday, March 29, 2007

Unmanned space missions

100 Unmanned space missions are those using remote-controlled spaceship. The first such assignment was the Sputnik I assignment, launched October 4, 1957. Some missions are more appropriate for unmanned missions rather than manned space missions, due to minor cost and lower risk factors. Since the early 1970s, most unmanned space missions have been based on space probe with built-in assignment computers, and as such may be classified as entrenched systems.

Most American unmanned missions have been synchronized by the Jet Propulsion Laboratory, and European missions by the European Space Operations Centre, part of ESA. ESA has conducted comparatively few space examination missions. ESA has, however, launched a variety of spacecraft to carry out astronomy, and is a coworker with NASA on the Hubble Space Telescope. There have been a great number of very winning Russian space missions. There were also a small number of Japanese and Chinese missions.

Sunday, March 25, 2007

Microphone

A microphone, sometimes called a mic (pronounced "mike"), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, tape recorders, hearing aids, motion picture production and in radio and television broadcasting.
The invention of a practical microphone was crucial to the early development of the telephone system. Emile Berliner made-up the first microphone on March 4, 1877, but the first helpful microphone was invented by Alexander Graham Bell. Many early developments in microphone design took place in Bell Laboratories.
In all microphones, sound waves (sound pressure) are translated into mechanical vibrations in a thin, flexible diaphragm. These sound vibrations are then converted by various methods into an electrical signal which varies in voltage amplitude and frequency in an analog of the original sound. For this reason, a microphone is an acoustic wave to voltage modulation transducer.

Tuesday, March 20, 2007

Flower anatomy

Flowering plants are heterosporangiate (producing two types of reproductive spores) and the pollen (male spores) and ovules (female spores) are created in different organs, but these are jointly in a bisporangiate strobilus that is the typical flower.
A flower is regarded as a customized stem with shortened internodes and bearing, at its nodes, structures that may be very modified leaves. In essence, a flower structure forms on a modified shoot or axis with an apical meristem that does not grow continuously (growth is determinate). The stem is called a pedicel, the end of which is the torus or receptacle. The parts of a flower are set in whorls on the torus. The four main parts or whorls (starting from the base of the flower or lowest node and working upwards) are as follows:
Poppycalyx – the outer whorl of sepals; typically these are green, but are petal-like in some species.
corolla – the whorl of petals, which are usually thin, soft and colored to attract insects that help the process of pollination.
androecium– one or two whorls of stamens, each a filament topped by an anther where pollen is produced. Pollen contains the male gametes.
gynoecium– one or more pistils. The female reproductive organ is the carpel: this contains an ovary with ovules (female gametes). A pistil may consist of a number of carpels merged together, in which case there is only one pistil to each flower, or of a single individual carpel (the flower is then called apocarpous). The sticky tip of the pistil, the stigma, is the receptor of pollen. The supportive stalk, the style becomes the pathway for pollen tubes to grow from pollen grains adhering to the stigma, to the ovules, carrying the reproductive material.

Wednesday, March 14, 2007

Black gold

Black gold is a type of gold used in jewelry. It is created by various methods, such as electrodeposition using black rhodium or ruthenium; plasma assisted chemical vapour deposition process concerning amorphous carbon; and controlled oxidation of carat gold containing chromium or cobalt. Electroplating solutions that have ruthenium give a slightly harder black coating than those that contain rhodium.

Unfortunately, black gold is very hard and making jewellery out if it regularly necessitates using previously-made melting forms. Varying the size, adding stones or other customizations are often too hard for the common goldsmith.

Black gold

Black gold is a type of gold used in jewelry. It is created by various methods, such as electrodeposition using black rhodium or ruthenium; plasma assisted chemical vapour deposition process concerning amorphous carbon; and controlled oxidation of carat gold containing chromium or cobalt. Electroplating solutions that have ruthenium give a slightly harder black coating than those that contain rhodium.

Unfortunately, black gold is very hard and making jewellery out if it regularly necessitates using previously-made melting forms. Varying the size, adding stones or other customizations are often too hard for the common goldsmith.

Friday, March 09, 2007

Silk

Silk, known as pattu, has a long history in India and is generally produced today. Historically silk was used by the upper classes, while cotton was used by the poorer classes. Today silk is mostly produced in Kanchipuram, Dharmavaram, Mysore, etc. in South India and Banaras in the North. "Murshidabad silk", well-known from historical times, is mostly produced in Malda and Murshidabad district of West Bengal and woven with hand looms in Birbhum and Murshidabad district. The silk from Kanchi is mainly well-known for its classic designs and enduring quality. The silk is traditionally hand-woven and hand-dyed and regularly also has silver threads woven into the cloth. Most of this silk is used to make saris. The saris usually are very expensive and vibrant in color. Garments made from silk form an integral part of Indian weddings and other celebrations. In the northeastern state of Assam, three different types of silk are produced, together called Assam silk: Muga, Eri and Pat silk. Muga, the golden silk, and Eri are produced by silkworms that are native only to Assam. The heritage of silk rearing and weaving is very old and continues today particularly with the production of Muga and Pat riha and mekhela sador, the three-piece silk saris woven with traditional motifs.

Monday, March 05, 2007

Mars

Mars is the fourth planet from the Sun and is known as the Red Planet due to its reddish look as seen from Earth. The planet is named after Mars, the Roman god of war. A terrestrial planet, Mars has a thin atmosphere and surface features reminiscent both of the impact craters of the Moon and the volcanoes, valleys, deserts and polar ice caps of Earth. It has the peak mountain in the solar system, Olympus Mons and the largest canyon, Valles Marineris. Mars' turning period and seasonal cycles are also related to those of the Earth.
Mars has two tiny natural moons, Phobos and Deimos, which orbit very close to the planet and are attention to be captured asteroids.
Both satellites were discovered in 1877 by Asaph Hall, and are named after the characters Phobos (panic/fear) and Deimos (terror/dread) who, in Greek mythology, accompanied their father Ares, god of war, into battle. Ares was known as Mars to the Romans.
From the surface of Mars, the motions of Phobos and Deimos appear very different from that of our own moon. Phobos rises in the west, sets in the east, and rises another time in just 11 hours. Deimos, being only just outside synchronous orbit—where the orbital period would match the planet's period of rotation—rises as expected in the east but very slowly. Despite the 30 hour orbit of Deimos, it takes 2.7 days to set in the west as it slowly falls behind the rotation of Mars, then just as long once more to rise.
Because Phobos' orbit is under synchronous altitude, the tidal forces from the planet Mars are slowly lowering its orbit. In about 50 million years it will either crash into Mars' surface or break up into a ring structure around Mars.

Thursday, March 01, 2007

Chili fruit

The fruit is eaten cooked or raw for its fiery hot flavour which is concerted along the top of the pod. The stem end of the pod has glands which create the capsaicin, which then flows down through the pod. The white pith, that surrounds the seeds, contains the highest concentrations of capsaicin. Removing the seeds and inner membranes is thus effectual at reducing the heat of a pod.
Chile powder is a spice made of the dried ground chilies, generally of the Mexican chile ancho variety, but with small amounts of cayenne added for heat, while chili powder is composed of dried ground chili peppers, cumin, garlic and oregano. The bottled hot sauce Tabasco sauce is made from Tabasco chilies, similar to cayenne, which may also be fermented. Chipotles are dry, smoked red (ripe) jalapeños.
Indian cooking has multiple uses for chilies, from snacks like bajji where the chilies are dipped in batter and fried to the infamously hot vindaloo. Chilies are also dried and roasted and salted for later use as a side dish for rice varieties like vadam (a kind of pappad). In Turkish or Ottoman cuisine, chilies are commonly used where it is known as Kırmızı Biber (Red Pepper) or Acı Biber (Hot Pepper). Sambal is dropping sauce made from chili peppers with many other ingredients such as garlic, onion, shallots, salt, vinegar and sugar, which is very popular in Indonesia, Malaysia and Singapore.