Sunday, February 25, 2007

Gold

Gold is a extremely sought-after valuable metal that for many centuries has been used as money, a store of value and in ornaments. The metal occurs as nugget or grains in rocks and in alluvial deposits and is one of the coinage metals. It is a soft, glossy, yellow, dense, malleable, and ductile change metal. Modern manufacturing uses include dentistry and electronics. Gold forms the basis for a financial typical used by the International Monetary Fund and the Bank for International resolution . Its ISO currency code is XAU.

Gold is a tinny element with a trait yellow color, but can also be black or ruby when finely alienated, while colloidal solutions are intensely tinted and often purple. These colors are the effect of gold's plasmon frequency lying in the visible range, which causes red and yellow glow to be reflected, and blue light to be engrossed. Only silver colloids show the same interactions with light, albeit at a shorter occurrence, making silver colloids yellow in color.

Gold is a good conductor of temperature and electricity, and is not precious by air and most reagents. Heat, damp, oxygen, and most corrosive agents have very little chemical effect on gold, making it well-suited for use in coins and jewelry; equally, halogens will chemically alter gold, and aqua regia dissolve it.

Pure gold is too soft for ordinary use and is hard-boiled by alloying with silver, copper, and other metals. Gold and its lots of alloys are most often used in jewelry, coinage and as a typical for monetary exchange in various countries. When promotion it in the form of jewelry, gold is calculated in karats , with pure gold being 24k. However, it is more commonly sold in lower capacity of 22k, 18k, and 14k. A lower "k" indicates a higher percent of copper or silver assorted into the alloy, with copper being the more typically used metal between the two. Fourteen karat gold-copper alloy will be almost identical in color to definite bronze alloys, and both may be used to produce polish and added badges. Eighteen karat gold with a high copper content is establish in some traditional jewelry and will have a distinct, though not dominant copper cast, giving an attractively warm color. A comparable karat weight when alloyed with silvery metals will appear less humid in color, and some low karat white metal alloys may be sold as "white gold", silvery in exterior with a slightly yellow cast but far more resistant to decay than silver or sterling silver. Karat weights of twenty and higher is more general in modern jewelry. Because of its high electrical conductivity and confrontation to decay and other desirable combinations of physical and chemical properties, gold also emerged in the late 20th century as an vital industrial metal, particularly as thin plating on electrical card associates and connectors.





Sunday, February 18, 2007

Rice vinegar

Rice vinegar is vinegar prepared from fermented rice or rice wine in China and Japan. Japanese rice vinegar is very soft and mellow and ranges in colour from colourless to pale yellow. There are two different types of Japanese vinegar: one is made from fermented rice and the other is made by adding rice vinegar to sake. Chinese rice vinegars are stronger than Japanese ones, and range in colour from clear to different shades of red and brown. Chinese and especially Japanese vinegars are very mild and sweet compared to purify and more acidic Western vinegars which, for that reason, are not proper substitutes for rice vinegars. White rice vinegar is colorless to pale yellow liquid, superior in vinegar content and more similar to Western vinegars, but still less acidic and milder in flavor.

Black rice vinegar is popular in southern China. Chinkiang vinegar, which originated in the city of Zhenjiang in the eastern coastal province of Jiangsu, China, is measured the best of the black rice vinegars. Usually black rice vinegar is made with glutinous rice, although millet or sorghum may be used instead. It is dark in colour, and has a deep, almost smoky flavor. In addition to Zhenjiang, it is too produced in Hong Kong.

Red rice vinegar is darker than white rice vinegar, and paler than black rice vinegar, with a typical red colour from Red yeast rice, which is cultivated with the mold Monascus purpureus. This vinegar has a distinctive flavour of its own due to the red mold. In Chinese cookbooks, ½ tablespoon of Western white vinegar is equivalent in strength to 1 tablespoon Chinkiang vinegar. Many Chinese people who grow up with rice vinegars take time to raise accustomed to the strength of Western vinegars when they begin to encounter them. Rice vinegar is also used to make sushi.

Monday, February 12, 2007

Chinese White Dolphin

The Chinese White Dolphin also called Indo-Pacific Humpback Dolphin, is a species of the Humpback dolphin and is one of eighty cetacean species. The adult dolphin is generally white or grey in colour. The population along the Chinese coast is unique in that they display a pink-coloured skin. This colour of the skin is not an effect of colour pigmentation, but is actually from blood vessels used for thermoregulation to avoid overheating during exertion. The adult's body length is about 220 - 250 centimeters and the infant's body length is about 1 meter. The normal weight of an adult is around 150 to 230 kilograms.
The Indo-Pacific dolphins can be found throughout Southeast Asia, and they breed from South Africa to Australia. There are two types, with Sumatra, one of the Indonesian islands, as the dividing line between the Chinese and the Western subspecies, Sousa chinensis plumbea. The two subspecies vary in color and size of their dorsal fin. The subspecies found in Southeast Asia has pinkish white skin and a bigger dorsal fin but lacks the fatty hump of its South African and Australian counterparts.

Monday, February 05, 2007

Jewellery

One universal issue is control over who could wear what jewellery, a point which indicate the powerful symbolism the wearing of jewellery evoked. In ancient Rome, for instance, only convinced ranks could wear rings; later, sumptuary laws dictated who could wear what type of jewellery; again based on rank. Cultural dictate have also played a important role; for example, the wearing of earrings by Western men was considered "effeminate" in the 19th and early 20th centuries. on the other hand, the jewellery industry in the early 20th century launched a crusade to popularize wedding rings for men — which caught on — as well as appointment rings for men , going so far as to make a false history and claim that the practice had Medieval roots. By the mid 1940s, 85% of weddings in the U.S. feature a double-ring ceremony, up from 15% in the 1920s.Religion has also played a role: Islam, for instance, consider the wearing of gold by men as a social taboo,and many religions have edicts against extreme display.