Tuesday, February 27, 2007

Constituents of sand

The most common constituent of sand, in inland continental settings and non-tropical coastal settings, is silica (silicon dioxide, or SiO2), typically in the form of quartz, which, because of its chemical inertness and considerable hardness, is resistant to weathering. The composition of sand varies according to local rock sources and conditions. The bright white sands originate in tropical and subtropical coastal settings are ground-up limestone. Arkose is a sand or sandstone with significant feldspar content which is derived from the weathering and erosion of a (usually nearby) granite. Some locations have sands that contain magnetite, chlorite, glauconite or gypsum. Sands rich in magnetite are dark to black in color, as are sands derivative from volcanic basalts. The chlorite-glauconite bearing sands are usually green in color, as are sands derived from basalts (lavas) with a high olivine content. The gypsum sand dunes of the White Sands National Monument in New Mexico are famous for their bright, white color. Sand deposits in some areas have garnets and other resistant minerals, with some small gemstones.

Thursday, February 22, 2007

The Institution of Engineers

The Institution of Engineers (IEI) was established by Sir Thomas Holland and others in Madras in 1920. In 1935, it obtained the Royal Charter from King George V to promote and move ahead the art, science and practice of engineering and technology in India.
The first President of the Institution was Sir Thomas R J Ward. Sir Thomas Guthrie Russell played a key role in the winning petition for a Royal Charter. The current President is Prof S C Naik.
The organization has been prominent amongst the founder members of the Commonwealth Engineers' Council and the Federation of Engineering Institutions of South and Central Asia. The Institution has a conditional membership of the Engineers Mobility Forum since 2003.
Today, the Institution is head-quartered in Kolkata, with 94 state and local centres. With half a million members, it is one of the biggest professional bodies in the English-speaking world. Life corporate members of the Institution are accredited with the Chartered Engineer title.

Sunday, February 18, 2007

Sun-Life cycle

The Sun's current age, determined via computer models of stellar evolution and nucleocosmochronology, is thought to be about 4.57 billion years.
The Sun is about halfway through its main-sequence growth, during which nuclear fusion reactions in its core fuse hydrogen into helium. Each second, more than 4 million tonnes of matter are changed into energy within the Sun's core, producing neutrinos and solar radiation. The Sun will waste a total of approximately 10 billion years as a main sequence star.
The Sun does not have sufficient mass to explode as a supernova. Instead, in 4-5 billion years, it will enter a red giant phase, its outer layers growing as the hydrogen fuel in the core is consumed and the core contracts and heats up. Helium fusion will start on when the core temperature reaches around 100 MK, and will make carbon and oxygen. While it is likely that the expansion of the outer layers of the Sun will reach the current position of Earth's orbit, latest research suggests that mass lost from the Sun previous in its red giant phase will cause the Earth's orbit to move more out, preventing it from being engulfed. However, Earth's water will be boiled away and most of its atmosphere will run off into space.
Following the red giant phase, strong thermal pulsations will cause the Sun to throw off its outer layers, forming a planetary nebula. The only object that will stay after the outer layers are ejected is the really hot stellar core, which will gradually cool and fade as a white dwarf over many billions of years. This stellar evolution scenario is typical of low- to medium-mass stars.

Sunday, February 11, 2007


Diamonds do not show all of their attractiveness as rough stones; instead, they must be cut and polished to exhibit the characteristic fire and intensity that diamond gemstones are known for. Diamonds are cut into a variety of shapes that are commonly designed to accentuate these features.Diamonds which are not cut to the specifications of round brilliant shape (or subsequent variations) are known as "fancy cuts." Popular fancy cuts include the baguette (from the French, meaning rod or loaf of bread), marquise, princess (square outline), heart, briolette (a form of the rose cut), and pear cuts. Newer cuts that have been introduced into the jewelry industry are the "cushion" "radiant"(similar to princess cuts, but with rounded edges instead of square edges) and "Asscher" cuts. Many fancy colored diamonds are now being cut according to these new styles. Generally speaking, these "fancy cuts" are not held to the same strict standards as Tolkowsky-derived round brilliants and there are less specific mathematical guidelines of angles which determine a well-cut stone. Cuts are influenced heavily by fashion: the baguette cut—which accentuates a diamond's luster and downplays its fire—was all the rage during the Art Deco period, whereas the princess cut—which accentuates a diamond's fire rather than its luster—is currently gaining popularity. The princess cut is also popular amongst diamond cutters: of all the cuts, it wastes the least of the original crystal. The past decades have seen the development of new diamond cuts, often based on a modification of an existing cut. Some of these include extra facets. These newly developed cuts are viewed by many as more of an attempt at brand differentiation by diamond sellers, than actual improvements to the state of the art

Monday, February 05, 2007

Early Stages of a pregnant woman and her health

Pregnancy is not an easy job for a woman. Starting from conception to birth, a woman's body carries out the most miraculous process of fertilization, implantation and the maturity and growth of her baby (or babies). Her body is her baby's dwelling place for the next nine months (or around 40 weeks) and the occurrences of pregnancy turn into a journey of many new physical feelings. Whether it is first, second, third (or more) pregnancy, her body will respond in a different way to each individual pregnancy. So health of a pregnant woman is very important to be taken care of.
Throughout the first 12 weeks of pregnancy called the '1st trimester’, a woman's body adjust to present a fostering and protective environment for her baby to grow and develop. Seldom, the early signs of pregnancy can make a woman feel puzzled. This may be for the reason that many of the physical signs of in the early hours of pregnancy such as enlarged tender breasts, sensitivity of tiredness, overstuffed and perhaps experiencing spasms and/or pelvic uneasiness can be considered as normal pre-menstrual signs. In all these stages the health of the woman declines because she is not only feeding herself, also her little developing fetus.
They may also sense disgusted or sick, due to morning sickness. It is not unusual to feel unsure about what is 'normal' during the early stages of pregnancy development, and unfamiliar signs or sensations may trigger concerns about the health, of her and baby. It’s been proved by the Gynecologists that every woman's body will react in a different way to being pregnant. Many women find their early pregnancy symptoms very difficult to cope with, both at work and generally.
Due to continuous vomiting and nourishing the fetus the pregnant woman may be exhausted very easily. She has to constantly keep her energetic by maintaining a healthy diet schedule as prescribed by the physicians. She can have more fresh green vegetables and fruit juices to make her feel fresh and energetic. It’s always significant to make sure that she avoids drinking and smoking because whatever she has will be directly absorbed by the baby. Once the fetus starts developing she has to get primed for all the obstacles she has to experience throughout pregnancy. Many psychologists predict that a healthy pregnancy is not only from taking care of the nutrition for the pregnant women, more than that she has to be taken care from all the hassles in her family. It’s the duty of a loving husband to caress her comfortably and keep her happy always throughout the gestation period. This will not only make the woman feel happy and hopeful it will directly lead to the good development of the fetus.