ECCE

NWChem is part of the Molecular Science Software Suite (MS ) which has been recognized by R D Magazine as one of the 100 most technologically signihcant new products and processes of 1999. The other elements of MS are Ecce, which is a problem-solving environment, and ParSoft, which is the underlying libraries and tools for parallel communication and high-performance input/output. All of the MS components are available publicly. 

Standards for food-grade chemicals in the United States are set by the Committee on Eood Chemicals Codex of the National Academy of Sciences (NAS) which pubHshes them in the Food Chemicals Codex (ECC) (6) (see also Eood additives). Standards for laboratory reagents are set by the American Chemical Society (ACS) Committee on Analytical Reagents and are pubHshed in Feagent Chemicals—A.CS Specifications (7). Standards for electronic-grade chemicals, which have extremely low limits for trace ions, are pubHshed aimually in The Book of SEMI Standards (BOSS) by Semiconductor Equipment and Materials International (SEMI) (8). 

Safety. A large inventory of radioactive fission products is present in any reactor fuel where the reactor has been operated for times on the order of months. In steady state, radioactive decay heat amounts to about 5% of fission heat, and continues after a reactor is shut down. If cooling is not provided, decay heat can melt fuel rods, causing release of the contents. Protection against a loss-of-coolant accident (LOCA), eg, a primary coolant pipe break, is required. Power reactors have an emergency core cooling system (ECCS) that comes into play upon initiation of a LOCA. 

There are numerous companies that mine, modify, and supply clays to the mbber industry. Huber and ECC are considered leaders in the field RT Vanderbilt is also a suppHer. There are numerous other national and local sources (see Clays). 

A vapor-phase process primarily for ECC off-gas feeds was developed by Sinopec Technology Company based on a 2eoHte catalyst of the Pentasd type (24,25). It reHes on frequent regeneration of the catalyst to minimi2e pretreatment of the ECC off-gas and allows the impurities in the feed gas to react with ben2ene to form by-products. Consequently, the product yield and purity are low. Joint licensing by ABB Lummus Crest and Sinopec was announced in 1994. 

At least six specifications of standards for granulated sugar quaUty are appHcable ia the United States. These include Codex JUimentarius Food Chemicals Codex (ECC) (4), US. Pharmacopeia (USP) and National Formula (NE) (5), National Soft Drink Association (6), National Canners Association, and Mihtary Standard-900 for white sugar. These standards are intended to set limits on various components, including, but not necessarily limited to, polarization, invert or reducing sugar, ash, moisture, color, sulfur dioxide, arsenic, lead, and copper. 

The other significant industrial route to /-butyl alcohol is the acid cataly2ed hydration of isobutylene (24), a process no longer practiced in the United States. Raffinate 1, C-4 refinery streams containing isobutylene [115-11-7], / -butenes and saturated C-4s or C-4 fluid catalytic cracker (ECC) feedstocks (23)... 

The primary U.S. producers of ground calcium carbonate are Columbia River Carbonates, ECC International, Franklin Limestone Co., Genstar Stone Products, Georgia Marble Company, J.M. Huber Corp., Calcium Carbonates Division, James River Limestone Co., Inc., OMYA Inc. 

ECC third ed. sequesterant in food, cross-linker. solution unspecified concentrations 17... 

P. E. Glascow and A. A. Murica, "Process and Mechanical Design Considerations for ECC Regeneration Air Distributors," presented at Katalistiks... 

N. L. Giuricich and B. Kalen, "Dominant Criteria ia ECC Cyclone Design," presented at Katalistiks 3rdA.nnualFCC Symposium, Amsterdam, The Nethedands, May 1982. 

C. A. Cabrera, C. L. Hebner, and S. P. Davis, "Improve Refinery Economics via Enhanced ECC Operations," presented at Katalistiks 8thMnnual FCC Symposium, Budapest, Hungary, June 1987. 

This tread has iaflueaced the supply and availability of cerium, particularly ia comparison to the availability of lanthanum-rich cerium-poor materials. The iacrease ia La demand for ECC catalysts up to the mid-1980s, together with the need to separate out cerium ia order to make the La-rich Ce-poor compositions increasingly preferred, led to a glut of Ce-based raw materials at that time. Ia 1991, the La-rich Ce-poor portioa of the raw material was ia excess supply over demand. 

Product specifications for microbial food enzymes have been estabUshed by JECEA and ECC. They limit or prescribe the absence of certain ubiquitous contaminants such as arsenic, heavy metals, lead, coliforms, E. coli and Salmonella. Furthermore, they prescribe the absence of antibacterial activity and, for fungal enzymes only, mycotoxins. 

T. Sinhora and S. Kasada, "A Real Time Dynamic Simulator for the Residue ECC Process," paper presented at Eastern Simulation Conference, Odando, Fla., Apr. 18-21,1988. 

FIG. 8-69 Ecc( ntric plii valve shown in erosion-resistant reverse flow direction, Shaded components can he made of hard metal or ceramic materials, Cm 1 li(isy Fislier-R/iseuimini. ... 

It was concluded that 1.5Ti-3.0Al should be considered the most suitable alloy for ECC flue gas expander rotors. A 1,400-mm diameter expander rotor disk was manufactured using this alloy. Test specimens removed from the disk rim showed that the disk had equivalent tensile properties at both room and elevated temperatures, and the same creep rupture strength as that of AISI 685. 

The software in the Turbolog DSP eontroller ineludes a eontrol algorithm ealled SHEDCON, whieh eontrols the regenerator differential pressure under all operating eonditions. This software was designed in 1984 speeifieally for ECC applieations and was improved for the refinery projeet deseribed here. 

The ECC unit operating requirements make it neeessary for the bypass eontrol valves to open as soon as the expander inlet valves start to elose. Optimum eontrol response is aehieved if the bypass valves open so that the pressure at the outlet of the regenerator remains eompletely unaffeeted by the expander shutdown. 

The innovative features, such as passive, gravity-driven ECCS, simplified RCS, digital I C, optimized plant arrangement, and modular construction methods, characterize the AP600 design. These changes result in fewer systems, equipment, operations, inspections, maintenance, and QA requirements (Table 6.1-7). Features of the AP-6(K) are as follows ... 

Pressure relief valves failed to reclose, and Operator error in failing to diagnose the accident and in tripping the automatic ECCS operation. 

An hour later, in preparation for the test, the ECCS was blocked for unknown icasons, in violation of regulations. This had no effect on the accident but indicates something about plant safety although the operators were reputed to be the best. 

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