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Urea or carbamide is an organic compound with the chemical formula (N H2)2C O. The molecule has two amine (-NH2) residues joined by a carbonyl (-CO-) functional group. Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals. Being solid, colourless, odorless, neither acidic nor alkaline, highly soluble in water, and relatively non-toxic, urea is widely used in fertilizers as a convenient source of nitrogen. Urea is also an important raw material for the chemical industry. The synthesis of this organic compound by Friedrich Wöhler in 1828 from an inorganic precursor was an important milestone in the development of chemistry. The terms urea and carbamide are also used for a class of chemical compounds sharing the same functional group RR'N-CO-NRR', namely a carbonyl group attached to two organic amine residues. Example include carbamide peroxide, allantoin, and hydantoin. Ureas are closely related to biurets and related in structure to amides, carbamates, diimides, carbodiimides, and thiocarbamides. From Wikipedia under the
GNU Free Documentation License  ofertas-commodities.com 271px x 525px | 23.80kB [source page] Ofertas de UREA Descargar Soft Offer Urea From Yahoo Image Search: "Urea"  handyman-source.com Handy Man ue, 17 Nov 2009 08:00:00 GM Some positive and alot more questions!!! ... hho hho tests HHO cell Hydrogen Hydrogen tests Hydrogen plates HHO plates.  physiciansskincare.blogspot.com Fred Martin MD (ret) Wed, 13 Jan 2010 20:45:00 GM That product is La Roche Posay Iso-. Urea. . Actually it works in all weather conditions, but our skin tends to be much dryer in colder weather, when our oil glands act like a bear in hibernation and almost totally shut-down. ...  hippobay.com unknown ue, 12 Jan 2010 11:05:01 GM Dominoes . Urea. pieces with pin (ItemID: 15124) by karastrade ZAR 30.00 (0 Bids) End Date: Sat, 13 Mar 2010 12:05:02 +0100 Duration: 2 Months | Country: South Africa | Zip/Postal Code: 7780 Category: General (1665) of Toys and Games (1628 ... From Google Blog Search: "Urea"  news.google.com Truck News Canadian agricultural products provider Agrium Inc. has entered into an exclusive agreement to supply diesel exhaust fluid-grade prilled urea from its ... and more » news.google.com Little About (blog) For his alleged role in the 1995 urea scam, Britain resident and Brazilian national Pinto was arrested in London in 1997 and was later extradited to India ... SC declines plea of urea scam accused Zee News all 10 news articles » news.google.com Automotive World Diesel exhaust fluid (DEF), the urea solution required by diesel-engined vehicles equipped with SCR (selective catalytic reduction) control of NOx emissions ... From Google News Search: "Urea" how to reduce the high pressure of liquid phase stream which consists of melamine and urea? Q. i'm doing the design of production of melamine. The liquid stream which out from reactor is 8000kpa and 400celcius.The stream consists of melamine and unreacted urea which in liquids phase. the pressure is too high. what equipments that i can used to depressurized the liquid stream? any body can give me the answer? Asked by cyin_86 - Fri Aug 22 03:39:52 2008 - - 1 Answers - 0 Comments A. First you need to cool it in a heat exchanger below about 80 celsius, otherwise it will boil. Then use adiabatic throttling to reduce the pressure to atmospheric. You will need a spring loaded pressure relief valve so as to maintain the 8000kpa pressure in the reactor. Make sure that there is plenty of surface area in the valve, or it might clog because of precipitated unreacted urea. Maybe have two pressure relief valves so that it is easy to switch to the other one for maintenance. You could also have a filter upstream of the valve to catch some of the urea crystals. Depending on how much urea is in the stream, you might need a cyclone separator. Answered by Dave D - Fri Aug 22 13:21:52 2008 What is the pathway of urea from the renal artery to the collecting ducts? Q. If you can, I'd prefer to see a website where I can verify your answer. Asked by HalfBloodPrincess - Tue Jan 26 20:58:53 2010 - - 1 Answers - 0 Comments A. it goes into the glomerulus which is the head of the nephron, and it goes through all of those channels including absorbing certain nutrients back into the body. Answered by mtwaites - Tue Jan 26 21:17:03 2010 What is the average concentration of urea in human urine?
Q. I have to find the value as a percentage, and I need a link or a reference to a book where it's quoted. It's for my coursework and it's holding me back as I've literally spent hours trying to find it on google and failed :( Any help much appreciated! Asked by Rubix - Sun May 18 07:29:20 2008 - - 2 Answers - 0 Comments A. Urea is an endogenous product of protein and aminoacid catabolism, and consequently 20-35 g of urea is excreted daily in human urine in avolume of about 1 - 1.5 litres. The amount will vary depending on protein intake since urea is produced from excess amino acids which the body doesn't need and is unable to store. Page 6 of this link - Answered by Peter S - Sun May 18 10:59:21 2008 From Yahoo Answer Search: "Urea" |
