Zinc, in commerce also spelter, is a chemical element; it has the symbol Zn and atomic number 30. It is the first element of group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is 2. Zinc is the 24th most abundant element in the Earth's crust and has five stable . The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest mineable amounts are found in Australia, A..
Copper is a chemical element with the symbol Cu (from cuprum) and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; a freshly exposed surface has a reddish-orange color. It is used as a conductor of heat and electricity, a building material, and a constituent of various metal .
André Coelho Matos (born September 14, 1971) is a Brazilian vocalist, pianist and composer. He was involved in the heavy metal bands Viper, Angra and Shaaman. Since October 2006 André Matos has been dedicating his time to his solo band.
Arthur Casagrande (August 28, 1902 – September 6, 1981) was an Austrian-born American civil engineer who made important contributions to the fields of engineering geology and geotechnical engineering during its infancy. Renowned for his ingenious designs of soil testing apparatus and fundamental research on and soil liquefaction, he is also credited for developing the soil mechanics teaching programme at Harvard University during the early 1930s that has since been modelled in many universities around th..
Electronic mail, most commonly called email or e-mail since around 1993, is a method of exchanging digital messages from an author to one or more recipients. Email operates across the Internet or other .
History (from Greek ἱστορία, historia, meaning "inquiry, knowledge acquired by investigation") is the study of the past, specifically how it relates to humans. It is an umbrella term that relates to past events as well as the discovery, collection, organization, and presentation of information about these events. The term includes cosmic, geologic, and organic history, but is often generically implied to mean human history. Scholars who write about history are called . Events occurring prior to wr..
A coupling (or a coupler) is a mechanism for connecting rolling stock in a train. The design of the coupler is standard, and is almost as important as the track gauge, since flexibility and convenience are maximised if all rolling stock can be coupled together.
In computing, a denial-of-service ( DoS) attack is an attempt to make a machine or network resource unavailable to its intended users, such as to temporarily or indefinitely interrupt or suspend services of a host connected to the Internet. A distributed denial-of-service ( DDoS) is where the attack source is more than one–and often thousands of-unique IP addresses.
Originally made of cotton or flax, most modern webbing is made of synthetic fibers such as nylon, polypropylene or polyester. Webbing is also made from exceptionally high-strength material, such as Dyneema, and Kevlar. Webbing is both light and strong, with breaking strengths readily available in excess of 10,000 lb (44.4 kN)
