Phosgene is the organic chemical compound with the formula COCl2. It is a colorless gas. Phosgene is a valued industrial building block for the production of urethanes and polycarbonate plastics. However, it is poisonous and was used as a chemical weapon during World War I where it was responsible for 85,000 deaths. In addition to its industrial production, small amounts occur from the breakdown and the combustion of organochlorine compounds. Phosgene is a planar molecule; the C=O distance is 1.18 Å, the C−Cl distance is 1.74 Å and the Cl−C−Cl angle is 111.8°. It is one of the simplest acyl chlorides, being formally derived from carbonic acid. Industrially, phosgene is produced by passing purified carbon monoxide and chlorine gas through a bed of porous activated carbon, which serves as a catalyst: CO + Cl2 → COCl2 The reaction is exothermic, therefore the reactor must be cooled; the reaction is conducted between 50 and 150 °C. Above 200 °C, phosgene reverts to carbon monoxide and chlorine, Keq = 0.05.
World production of this compound was estimated to be 2.74 million tonnes in 1989. Because of safety issues, phosgene is produced and consumed within the same plant, extraordinary measures are made to contain it, it is listed on Schedule 3 of the Chemical Weapons Convention: All production sites manufacturing more than 30 tonnes per year must be declared to the OPCW. Although less dangerous than many other chemical weapons such as sarin, phosgene is still regarded as a viable chemical warfare agent because it is so easy to manufacture when compared to the production requirements of more technically advanced chemical weapons such as the first-generation nerve agent tabun. Upon ultraviolet radiation in the presence of oxygen, chloroform converts into phosgene by a radical reaction. To suppress this photodegradation, chloroform is stored in brown-tinted glass containers and with a small percentage of ethanol added. Chlorinated solvents used to remove oil from metals, such as automotive brake cleaners, are converted to phosgene by the UV rays of arc welding processes.
Phosgene may be produced during testing for leaks of older-style refrigerant gases. Chloromethanes were leak-tested in situ by employing a small gas torch with a sniffer tube and a copper reaction plate in the flame nozzle of the torch. If any refrigerant gas was leaking from a pipe or joint, the gas would be sucked into the flame through the sniffer tube and would cause a colour change of the gas flame to a bright greenish blue. In the process, phosgene gas would be created due to the thermal reaction. No valid statistics are available, but anecdotal reports suggest that numerous refrigeration technicians suffered the effects of phosgene poisoning due to their ignorance of the toxicity of phosgene, produced during such leak testing. Electronic sensing of refrigerant gases phased out the use of flame testing for leaks in the 1980s. Phosgene poisoning is a possibility for people fighting fires that occur in the vicinity of refrigerant leaks from air-conditioning systems or refrigeration equipment, smoking in the vicinity of a freon refrigerant leak, or fighting fires using halon or halotron.
Phosgene can be released during building fires. In one instance, a deputy fire chief died ten days after inhaling fumes that wafted down outside a burning restaurant. After a two-day hospitalization he had appeared to recover, but suffered cardiac arrest at home following tracheobronchial inflammation, alveolar hemorrhage, pulmonary edema; the phosgene was produced by decomposing Freon 22 after flames ducted up from a grease fire heated an air-conditioning unit on the roof and ruptured a hose. Phosgene was synthesized by the Cornish chemist John Davy in 1812 by exposing a mixture of carbon monoxide and chlorine to sunlight, he named it "phosgene" in reference of the use of light to promote the reaction. It became important in the chemical industry as the 19th century progressed in dye manufacturing; the great majority of phosgene is used in the production of isocyanates, the most important being toluene diisocyanate and methylene diphenyl diisocyanate. These two isocyanates are precursors to polyurethanes.
The reaction of an organic substrate with phosgene is called phosgenation. Significant amounts are used in the production of polycarbonates by its reaction with bisphenol A. Polycarbonates are an important class of engineering thermoplastic found, for example, in lenses in eyeglasses. Diols react with phosgene to give either linear or cyclic carbonates: HOCR2−X−CR2OH + COCl2 → 1⁄n n + 2 HClPhosgenation of hydroxamic acids gives dioxazolone, a class of cyclic carbonate esters: RCNHOH + COCl2 → RC=NOCO2 + 2 HCl The synthesis of isocyanates from amines illustrates the electrophilic character of this reagent and its use in introducing the equivalent of "CO2+": RNH2 + COCl2 → RN=C=O + 2 HCl Such reactions are conducted in the presence of a base such as pyridine that absorbs the hydrogen chloride. In the research laboratory phosgene still finds limited use in organic synthesis. A variety of substitutes have been developed, notably trichloromethyl chloroformate, a liquid at room temperature, bis carbonate, a crystalline substance.
Aside from the above reactions that are practiced industrially, phosgene is used to produce acyl chlorides and carbon dioxide from carboxylic acids: RCO2H + COCl2 → RCCl + HCl + CO2Such acid chlorides react with amines and
Arthur Andrew Demarest is an American anthropologist and archaeologist, known for his studies of the Maya civilization. Demarest, a Louisiana Cajun, studied Mesoamerican anthropology and archaeology at Tulane University, where he graduated Summa Cum Laude and was awarded the Dean's Medal. Demarest earned his M. A. and doctorate in anthropology and archaeology at Harvard University, he held the endowed Danforth Chair in Archeology, was elected to the prestigious Harvard Society of Fellows club. From 1984 to 1986 he served as Assistant Professor at Vanderbilt University in Tennessee, USA. In 1986 he was named to the endowed Centennial Chair, he now holds the endowed chair of Ingram Professor of Anthropology and is the Director of Mesoamerican Archaeology and Development. Demarest has worked in Mesoamerica for over 35 years, leading archaeological excavations and investigative expeditions every year, he is considered one of the world's leading experts on the Maya, but is interested in the Olmec, Incas and many aspects of anthropological theory the collapse of civilizations, the role of religion in ancient societies, ethics in anthropology.
He divides his efforts between archaeological excavations and exploration, development programs for indigenous Maya communities, management of the Vanderbilt-owned, but Maya-managed, Cancuen tropical forest and archaeological park in the Peten region of Guatemala. He is director of both the Vanderbilt Cancuen Regional Archaeological project in the Peten forest of Guatemala and the Vanderbilt/Universidad del Valle San Andres Semetabej Regional Archaeology and Development projects in Guatemala's volcanic highlands. Demarest has been involved in several lawsuits filed by graduate student Brigitte Kovacevich regarding his actions while conducting scientific research in Guatemala; the first of these lawsuits was filed in 2007, alleged that Demarest "engaged in repeated unprofessional and outrageous conduct that included burning down the field camp, destruction of artifacts, fabrication of a crime scene, the misappropriation and misuse of Vanderbilt University and government funds, threats against students and assaults of students."
That suit was settled in 2008. Demarest was again sued in the following year for violating the terms of the previous settlement. Kovacevich alleged that Demarest contacted the University Press of Colorado and claimed that Kovacevich did not have permission from an artist to use certain illustrations in her book, Demarest attempted to coerce the artist into withdrawing his consent; that suit was settled. In 2010 Science published a profile of his work. Demarest's work with the Maya in Mesoamerica has been featured in many TV documentaries by National Geographic, the History Channel, Travel Channel, NBC, CBS, programs in Brazil and Guatemala; as an authority in the field, Demarest has been interviewed on NPR, CBS, other venues and most the PBS Lehrer News hour regarding his research development work, the ancient Maya civilization and the collapse of civilizations. Demarest himself is the author or editor of over a dozen books and monographs and over a hundred articles and book chapters. Demarest has been awarded various prizes for his archaeological and educational work in Guatemala and for his development work assisting contemporary Q'eqchi' contemporary Maya people communities.
In 2000 Demarest was presented with the Orden del Pop, a career leadership award bestowed by Guatemala's Universidad Francisco Marroquín in recognition of his services to Guatemalan archaeology his training of most of the current Guatemalan leaders in the archaeology of their country. In 2004 Demarest became the first U. S. citizen to be awarded the Orden Nacional del Patrimonio Cultural de Guatemala. Demarest was presented with that award by the President of Guatemala, Óscar Berger, in a ceremony on November 10 of that year with a citation for his successful battles with looters and his contributions to "the rescue and protection of the tangible cultural patrimony of Guatemala."Dr. Demarest was named Distinguished Alumni for 2003 by Tulane University, he has won the Madison-Sarratt Award from Vanderbilt University for outstanding undergraduate teaching in the Arts and Sciences College. Dr. Demarest, his wife, Vilma Lorena Anleu de Demarest and three sons are residents in Guatemala and the U.
S. and frequently in Finland, where they collaborate with European museum exhibitions and international indigenous development efforts. Presentation on the Vanderbilt University website. Works by or about Arthur Demarest in libraries
The Parish of Lake George is an Australian parish of the County of Murray which covers Lake George and part of the surrounding area. It is with Argyle to the north-east; the Federal Highway runs through the parish. Some parish maps of the area just record it as a lake and not as a parish, however it does have separate parish maps. Gearys Gap lookout, where the federal highway meets Lake George in the south, is just in the parish, on the edge. From this point for about a mile northward the boundary of the parish is near the road further northward the parish includes the Lake George Range to the west of the road as well. Old parish maps show the area was divided between Yarrowlumla Shire in the south, Gunning Shire in the west and Mulwaree Shire in the north-east, they note the area was in the Pastures Protection Districts of Braidwood and Goulburn, a Sanctuary for birds and animals was proclaimed for part of the area on 12 September 1919. New South Wales Parish maps preservation project "Lake George".
Geographical Names Register of NSW. Geographical Names Board of New South Wales. Retrieved 4 August 2013
The 2014 NASCAR Nationwide Series was the 33rd season of the Nationwide Series, a stock car racing series sanctioned by the NASCAR in the United States. It began with the DRIVE4COPD 300 at Daytona International Speedway on February 22, ended with the Ford EcoBoost 300 at Homestead-Miami Speedway on November 15; this was the final year that the Nationwide Mutual Insurance Company sponsored the series, opting for increased involvement in the Sprint Cup Series, as well as the final season the series was broadcast by ESPN. Ford entered the season as the defending Manufacturer's Champion. After 2014, Xfinity became the series sponsor. Notes Between the 2013 and 2014 seasons, several driver changes have occurred. Kevin Harvick will run with JR Motorsports for 13 races. Numerous drivers will move up to the Nationwide Series full-time. Maryeve Dufault will contest a limited schedule. Sam Hornish, Jr. moves from Penske Racing to Joe Gibbs Racing, where he will share a ride with Kyle Busch. Kyle Busch Motorsports will not field any cars in 2014 due to lack of funding.
The calendar was released on October 18, 2013. Bold – Pole position awarded by qualifying time. Italics – Pole position earned by points standings or practice time. * – Most laps led Bold - Pole position awarded by time. Italics - Pole position set by final practice results or rainout. * – Most laps led. 2014 NASCAR Sprint Cup Series 2014 NASCAR Camping World Truck Series 2014 NASCAR K&N Pro Series East 2014 NASCAR K&N Pro Series West 2014 NASCAR Whelen Modified Tour 2014 NASCAR Whelen Southern Modified Tour 2014 NASCAR Canadian Tire Series 2014 NASCAR Toyota Series 2014 NASCAR Whelen Euro Series
Since the rise of the personal computer in the 1980s, IBM and other vendors have created PC-based IBM-compatible mainframes which are compatible with the larger IBM mainframe computers. For a period of time PC-based mainframe-compatible systems had a lower price and did not require as much electricity or floor space. However, they were not as dependable as mainframe-class hardware; these products have been popular with mainframe developers, in education and training settings, for small companies with non-critical processing, in certain disaster relief roles. Up until the mid-1990s, mainframes were large machines that occupied entire rooms; the rooms were air conditioned and had special power arrangements to accommodate the three-phase electric power required by the machines. Modern mainframes are now physically comparatively small and require little or no special building arrangements. IBM had demonstrated use of a mainframe instruction set in their first desktop computer—the IBM 5100, released in 1975.
This product used microcode to execute many of the System/370's processor instructions, so that it could run a modified version of IBM's APL mainframe program interpreter. In 1980 rumors spread of a new IBM personal computer a miniaturized version of the IBM System/370. In 1981 the IBM Personal Computer appeared. However, IBM did use their new PC platform to create some exotic combinations with additional hardware that could execute S/370 instructions locally. In October 1983, IBM announced the IBM Personal Computer XT/370; this was a three-in-one product. It could run PC DOS locally, it could act as 3270 terminal, finally—its most important distinguishing feature relative to an IBM 3270 PC—was that it could execute S/370 instructions locally; the XT/370 was an IBM Personal Computer XT with three custom 8-bit cards. The processor card, contained two modified Motorola 68000 chips, an Intel 8087 coprocessor modified to emulate the S/370 floating point instructions; the second card, which connected to the first with a unique card back connector contained 512 KiB of memory.
The third card, was a 3270 terminal emulator required to download system software from the host mainframe. The XT/370 computer booted into DOS ran the VM/PC Control Program; the card's memory space added additional system memory, so the first 256 KiB memory could be used to move data to the 512 KiB expansion card. The expansion memory was dual ported, provided an additional 384 KiB to the XT Machine bringing the total RAM on the XT side to 640 KiB; the memory arbitrator could bank switch the second 128 KiB bank on the card to other banks, allowing the XT Intel 8088 processor to address all the RAM on the 370PC-M card. Besides the 416 KB of usable RAM for S/370 applications, the XT/370 supported up to 4 MB of virtual memory using the hard drive as its paging device. IBM claimed the XT/370 reached 0.1 MIPS. In 1984, the list price of an XT/370 in its typical configuration was $12,000 so compared favorably with IBM's own mainframes on a $/MIPS basis. While it theoretically reduced demand on customers' mainframes by offloading load onto the smaller computer, as customers purchased more XT/370s they increased the overall load on the mainframes, increasing IBM's mainframe sales.
To the mainframe version of VM/CMS, the VM/PC created the illusion of virtual disks, but on the PC version these were maintained as PC DOS files, either on floppy or hard disk. For example, the CMS virtual disk belonging to user FRED at device address 101 was stored as the DOS file FRED.101. The CMS IMPORT and EXPORT commands allowed extraction of files from these virtual drives as well as ASCII/EBCDIC conversion; the XT/370 came with an XT-style 83-key keyboard. Newer revisions of the XT/370 dropped the PC3277-EM in favor of the IBM 3278/79 boards; the XT/370 was among the XT systems that could use a second hard drive mounted in the 5161 expansion chassis. BYTE in 1984 called the XT/370 "a qualified success"; the magazine praised IBM for "fitting all of the 370's features into the XT", hoped for technical improvements that "might result in an better computer". In 1984, IBM introduced the IBM Personal Computer AT/370 with similar cards as for the XT/370 and updated software, supporting both larger hard disks and DMA transfers from the 3277 card to the AT/370 Processor card.
The system was 60% faster than the XT/370. The AT/370 used different, 16-bit interface co-processing cards than the XT, called PC/370-P2 and PC/370-M2; the latter card still had only 512 KB for memory, out of which 480 KB were usable for programs in S/370 mode, while 32 KB were reserved for microcode storage. For the terminal emulation function, the AT/370 came with the same 3278/79 Emulation Adapter as the late-series XT/370; the AT/370 motherboard itself was equipped with 512 KB of RAM. The AT/370 ran VM/PC, but with PC DOS 3.0 instead of 2.10 that the XT version used. VM/PC version 2, launched in November 1985, improved performance by up to 50%. A November 1985 Computerworld article noted that the machine was "slow selling". In April 1988, IBM introduced a System/370 workstation, shipping to some customers since August 1987. Called the IBM 7437 VM/SP Technical Workstation, it was a freestan
Celso Esquivel González is a Paraguayan footballer, playing for Club Almagro of the Primera B Metropolitana in Argentina.. Esquivel played in Argentina for San Lorenzo, Racing Talleres. In his native country he did for Sportivo Luqueño. Esquivel was a member of the Paraguayan squad at the 2001 FIFA World Youth Championship and was part of the silver medal-winning Paraguayan 2004 Olympic football team. Paraguay U23 Olympic Games: in Athens Celso Esquivel at Football Lineups Celso Esquivel at BDFA Celso Esquivel at National-Football-Teams.com Argentine Primera statistics at Fútbol XXI at the Wayback Machine