This paper presents a new approach for the automatic definition and treatment of mechanical contact in explicit nonlinear finite element analysis. Automatic contact offers the benefits of significantly reduced model construction time and fewer opportunities for user error, but faces significant challenges in reliability and computational costs. Key aspects of the proposed new method include automatic identification of adjacent and opposite surfaces in the global search phase, and the use of a well-defined surface normal which allows a consistent treatment of shell intersection and corner contact conditions without a ad-hoc rules. The paper concludes with three examples which illustrate the performance of the newly proposed algorithm in the public DYNA3D code.

This project is aimed at development of a process that, by using ultra fine magnetite suspension, would expand the application of heavy media separation technology to processing fine, {minus}28 mesh coals. These coal fines, produced during coal mining and crushing, are separated in the conventional coal preparation plant and generally impounded in a tailings pond. Development of an economic process for processing these fines into marketable product will expand the utilization of coal for power production in an environmentally acceptable and economically viable way. This process has been successfully researched at PETC but has not been studied on a continuous bench-scale unit, which is a necessary step towards commercial development of this promising technology. The goal of the program is to investigate the technology in a continuous circuit at a reasonable scale to provide a design basis for larger plants and a commercial feasibility data. The project is divided into eight tasks which include design, construction, operation and testing, sample analysis, evaluation, and decommissioning. Coal will be received from three different mines and processed through the bench scale{backslash}e plant. Testing has been split into three phases: (1) Component Testing which will examine each of the major components independently, optimize, and …

A Texas Instruments (TI) TMS320C30-based S-Bus digital signal processing (DSP) module was used to accelerate a wavelet-based compression and decompression algorithm applied to high-resolution fingerprint images. The law enforcement community, together with the National Institute of Standards and Technology (NISI), is adopting a standard based on the wavelet transform for the compression, transmission, and decompression of scanned fingerprint images. A two-dimensional wavelet transform of the input image is computed. Then spatial/frequency regions are automatically analyzed for information content and quantized for subsequent Huffman encoding. Compression ratios range from 10:1 to 30:1 while maintaining the level of image quality necessary for identification. Several prototype systems were developed using SUN SPARCstation 2 with a 1280 {times} 1024 8-bit display, 64-Mbyte random access memory (RAM), Tiber distributed data interface (FDDI), and Spirit-30 S-Bus DSP-accelerators from Sonitech. The final implementation of the DSP-accelerated algorithm performed the compression or decompression operation in 3.5 s per print. Further increases in system throughput were obtained by adding several DSP accelerators operating in parallel.

Preliminary sketches of the furnace setting with dimensions and other appropriate data was distributed to appropriate boiler design groups. The purpose of this work was to define and/or establish unique mechanical and support requirements and furnace water circulation requirements. A preliminary convection pass arrangement and heating surface requirements were established. Initial computer runs indicate, as expected, that establishing even a preliminary arrangement to meet steam duty requirements was going to be a challenge. This due to slightly lower furnace exit gas temperatures (result of NO{sub x} control conditions) and higher final steam temperatures (results increasing plant efficiency) than typical of conventional design. Work on the furnace and convection pass design for the base preliminary unit was completed only to the extent necessary to identify design deficiencies, prepare an arrangement drawing and determine budgetary cost. Engineering work has been completed to the extent planned in this subtask for the base preliminary unit, Advanced Overfire Air, including preliminary designs for the furnace, convection pass, pulverizers, airheaters, flues and ducts, preliminary general arrangement drawings, and budgetary cost estimates. Work is nearly complete on design of the LEBS unit control system based on control methods and philosophy established in the NO{sub x} Control Subsystems. …

The Geotechnical Board, a part of the US National Research Council, which is the operating arm of the National Academy of Sciences and the National Academy of Engineering, serves to advise the federal government and others on issues where geotechnology can have an impact, such as environmental remediation and infrastructure development. The board met three times during the reporting period to review current projects and to initiate activities that move the knowledge base of geotechnology forward. The board operates with two long-standing national committees, the US National Committee for Rock Mechanics and the US National Committee on Tunneling Technology. It also conducts special studies at the request of the government. A list of attachments is given.

One of the major obstacles to the economical use of coal is managing the behavior of its mineral matter. Ash size and composition are of critical importance for a variety of reasons. Fly ash size and emissivity affect radiant furnace heat transfer. Heat transfer is also affected by the tendency of ash to adhere to heat transfer surfaces, and the properties of these deposits. Removal of ash from flue gas by electrostatic precipitators is influenced by both particle size and particle resistivity. The efficiency of fabric filter-based cleaning devices is also influenced by ash size. Both types of devices have reduced collection efficiencies for smaller-sized particles, which corresponds to the size most efficiently retained in the alveolar region of the human lung. Laboratory work and studies of full-scale coal-fired boilers have identified two general mechanisms for ash production. The vast majority of the ash is formed from mineral matter that coalesces as the char burns, yielding particles that are normally larger than 0.5 {mu}m. The second major mechanism is the generation of a submicron aerosol through a vaporization/condensation mechanism. Although these particles represent a relatively small fraction of the mass, they can present a large fraction of the surface area. …

A phase 2 study has been initiated to investigate surfactant- assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This report covers the fourth quarter of work. The major accomplishments were (1) Completion of coal liquefaction autoclave reactor runs and related analysis with Illinois {number_sign}6 coal with time as a variable at 375{degree}C, and pressures of 1800 psig; (2) an investigation into the mechanism of the effect that the lignosulfonate surfactant has in enhancing liquefaction yields; and (3) completion of a bench-scale test with the surfactant in the continuous flow Catalytic Two Stage Liquefaction Process (CTSL) reactor at HRI.

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A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.