The carbonate fuel cell promises highly efficient, cost-effective, environmentally superior power generation from pipeline natural gas, coal gas, biogas, and other gaseous and liquid fuels. ERC has been engaged in the development of this unique technology since the late 1970s, primarily focusing on the development of the Direct Fuel Cell (DFC) technology [1-6] pioneered by ERC. The DFC design incorporates the unique internal reforming feature which allows utilization of a hydrocarbon fuel directly in the fuel cell without requiring any external reforming reactor and associated heat exchange equipment. This approach provides upgrading of waste heat to chemical energy; thereby, it contributing to higher overall efficiency for conversion of fuel energy to electricity with low levels of environmental emissions. Among the internal reforming options, ERC has selected the Indirect Internal Reforming (IIR) - Direct Internal Reforming (DIR) combination as its baseline design. ERC plans to offer commercial DFC power plants in various sizes, initially focusing on the MW-scale units. The plan is to offer standardized, packaged MW-scale DFC power plants operating on natural gas or other hydrocarbon-containing fuels for commercial sale by the end of the decade. These power plants, which can be shop-fabricated and sited near the user, are ideally …

For years, contamination has been known to degrade the performance of optics and to sometimes initiate laser-induced damage to initiate. This study has W to quantify these effects for fused silica windows used at 355 mm Contamination particles (Al, Cu, TiO{sub 2} and ZrO{sub 2}) were artificially deposited onto the surface and damage tests were conducted with a 3 ns NdYAG laser. The damage morphology was characterized by Nomarski optical microscopy. The results showed that the damage morphology for input and output surface contamination is different. For input surface contamination, both input and output surfaces can damage. In particular, the particle can induce pitting or drilling of the surface where the beam exits. Such damage usually grows catastrophically. Output surface contamination is usually ablated away on the shot but can also induce catastrophic damage. Plasmas are observed during illumination and seem to play an important role in the damage mechanism. The relationship between fluence and contamination size for which catastrophic damage occurred was plotted for different contamination materials. The results show that particles even as small as 10 {micro}m can substantially decrease the damage threshold of the window and that metallic particles on the input surface have a more negative …

This paper describes a fiber-optic pH sensor based upon sol-gel encapsulation of a self-referencing dye, seminaphthorhodamine-1 carboxylate (SNARF-1C). The simple sol-gel fabrication procedure and low coating leachability are ideal for encapsulation and immobilization of dye molecules onto the end of an optical fiber. A miniature bench-top fluorimeter system was developed for use with the optical fiber to obtain pH measurements. Linear and reproducible responses were obtained in human blood in the pH range 6.8 to 8.0, which encompasses the clinically-relevant range. Therefore, this sensor can be considered for in vivo use.

We have presented a fast linear time algorithm for recognizing tandem repeats. Our algorithm is a one pass algorithm. No information about the periodicity of tandem repeats is needed. The use of the indices calculated from non-continuous and overlapping {kappa}-tuples allow tandem repeats with insertions and deletions to be recognized.

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This paper introduces PS300, a plasma sprayed, self-lubricating composite coating for use in sliding contacts at temperatures to 800{degrees}C. PS300 is a metal bonded chrome oxide coating with silver and BaF{sub 2}/CaF{sub 2} eutectic solid lubricant additives. PS300 is similar to PS200, a chromium carbide based coating; which is currently being investigated for a variety of tribological applications. In pin-on-disk testing up to 650{degrees}C, PS300 exhibited comparable friction and wear properties to PS200. The PS300 matrix, which is predominantly chromium oxide rather than chromium carbide, does not require diamond grinding and polishes readily with silicon carbide abrasives greatly reducing manufacturing costs compared to PS200. It is anticipated that PS300 has potential for sliding bearing and seal applications in both aerospace and general industry.

Ames Laboratory will develop an integrated sampling and analysis system suitable for on-line monitoring of mercury (Hg) and hydrogen chloride (HCl) in advanced coal-based gasifiers. The objectives of this project are to (1) summarize current technology for monitoring Hg and HCl in gaseous effluents; (2) identify analytical techniques for such determinations in high-temperature, high-pressure gases from coal-based systems for producing electrical power; (3) evaluate promising analytical approaches, and (4) produce reliable on-line monitors which are adaptable to plant-scale diagnostics and process control. For HG, the techniques selected for further consideration were atomic absorption and atomic fluorescence. For HCl, non-dispersive infrared absorption, a dry colorimetric procedure, and ion mobility spectroscopy were selected for testing in the laboratory. Results to date are described.

A general model for predicting the solubility properties of refrigerant/lubricant mixtures has been developed based on applicable theory for the excess Gibbs energy of non-ideal solutions. In our approach, flexible thermodynamic forms are chosen to describe the properties of both the gas and liquid phases of refrigerant/lubricant mixtures. After an extensive study of models for describing non-ideal liquid effects, the Wohl-suffix equations, which have been extensively utilized in the analysis of hydrocarbon mixtures, have been developed into a general form applicable to mixtures where one component is a POE lubricant. In the present study we have analyzed several POEs where structural and thermophysical property data were available. Data were also collected from several sources on the solubility of refrigerant/lubricant binary pairs. We have developed a computer code (NISC), based on the Wohl model, that predicts dew point or bubble point conditions over a wide range of composition and temperature. Our present analysis covers mixtures containing up to three refrigerant molecules and one lubricant. The present code can be used to analyze the properties of R-410a and R-407c in mixtures with a POE lubricant. Comparisons with other models, such as the Wilson or modified Wilson equations, indicate that the Wohl-suffix equations …

A diode-side-pumped discrete-optic E{sup 3+}:YAG laser employs pump-light coupling through a sapphire plate diffusion-bonded to the laser slab, giving reduced thermal lensing and exceptional beam quality (M{sup 2} {approx} 1.3.) The novel architecture is also applicable to other side-pumped lasers.

Press information, on the Annenberg Foundation, announcing their latest series of grants towards arts education. A $4.3 million challenge grant to six regional institutes to show how the arts can boost student academic achievements. The foundation is working with the Getty Center for Education and their consortia which includes, North Texas Institute for Educators on the Visual Arts.

A news release report, on North Texas Institute for Educators on the Visual Arts, one of the six recipients nationally of a $4.3 million challenge grant announced by the Annenberg Foundation. The grant goal is to reform public schools using a bold program of arts education. The grant will provide $1.43 million for UNT"s North Texas Institute for Educators on the Visual Arts to demonstrate how education in the arts can improve students.

Carbons derived from polymethylacrylonitrile (PMAN) have been studied for use as intercalation anodes in Li-ion cells. The effect of Si doping upon the electrochemical performance of PMAN carbons was studied using tetravinylsilane (TVS) and tetramethysilane (TMS) as sources of Si during the formation of the PMAN precursors. The carbons were characterized by galvanostatic cycling, cyclic voltammetry, and complex impedance. The presence of 9 to 11 w/o Si in the PMAN lattice greatly increased the irreversible capacity of these materials.

Cathode performance is critical to lithium ion rechargeable battery performance; effects of doping lithium manganese oxide cathode materials on cathode performance are being investigated. In this paper, Li diffusion in Al-doped LiMn{sub 2}O{sub 4} was studied and found to be controlled by the quantity of Al dopant. Electrochemical cycling was conducted at 0.5mA/cm{sub 2}; electrochemical impedance spectra were taken at open circuit potential, with impedance being measured at 65 kHz-0.01 Hz. As the Al dopant level was increased, the Li diffusion rate decreased; this was attributed to the decreased lattice parameter of the doped oxide.

The noninductive current driven by fast Alfven waves (FWCD) has been applied to discharges in DIII-D with negative central shear. Driven currents as high as 275 kA have been achieved with up to 3 MW of fast wave power with the efficiency and profile as predicted by theory-based modeling. When counter-current FWCD was applied to discharges with negative central shear, the negative shear was strengthened and prolonged, showing that FWCD can help to control the current profile in advanced tokamak discharges. Under some conditions in negative central shear, the plasma spontaneously makes a transition into a regime of improved performance, with a reduction in both the ion and the electron heat diffusivities. Up to 3 MW of fast wave power has been successfully coupled into H-mode discharges with large edge localized modes through use of an innovative decoupler/hybrid power splitter combination.

A titanate-based ceramic waste form, rich in phases structurally related to zirconolite (CaZrTi{sub 2}O{sub 7}), is being developed as a possible method for immobilizing excess plutonium from dismantled nuclear weapons. As part of this program, Lawrence Livermore National Laboratory (LLNL) produced several ceramics that were then characterized at Argonne National Laboratory (ANL). The plutonium- loaded ceramic was found to contain a Pu-Gd zirconolite phase but also contained plutonium titanates, Gd-polymignyte, and a series of other phases. In addition, much of the Pu was remained as PuO{sub 2- x}. The Pu oxidation state in the zirconolite was determined to be mainly Pu{sup 4+}, although some Pu{sub 3+} was believed to be present.

We are developing a prototype zooming World-Wide Web browser within Pad++, a multiscale graphical environment. Instead of having a single page visible at a time, multiple pages and the links between them are depicted on a large zoomable information surface. Pages are scaled so that the page in focus is clearly readable with connected pages shown at smaller scales to provide context. We quantitatively compared performance with the Pad++ Web browser and Netscape in several different scenarios. We examined how quickly users could answer questions about a specific Web site designed for this test. Initially we found that subjects answered questions slightly slower with Pad++ than with Netscape. After analyzing the results of this study, we implemented several changes to the Pad++ Web browser, and repeated one Pad++ condition. After improvements were made to the Pad++ browser, subjects using Pad++ answered questions 23% faster than those using Netscape.

This paper presents a simple, systematic approach for developing accident scenarios using generic accident types. Result is a necessary and sufficient set of accident scenarios that can be used to establish the safety envelope for a facility or operation. Us of this approach along with the methodology of SAND95-0320 will yield more consistent accident analyses between facilities and provide a sound basis for allocating limited risk reduction resources.

Organic analysis is the analytical arm for several Los Alamos National Laboratory (LANL) research programs and nuclear materials processes, including characterization and certification of nuclear and nonnuclear materials used in weapons, radioactive waste treatment and waste certification programs. Organic Analysis has an extensive repertoire of analytical technique within the group including headspace gas, PCBs/pesticides, volatile organics and semivolatile organic analysis. In addition organic analysis has mobile labs with analytic capabilities that include volatile organics, total petroleum hydrocarbon, PCBs, pesticides, polyaromatic hydrocarbons and high explosive screening. A natural extension of these capabilities can be applied to the detection of chemical and biological agents,

Reciprocal connections, in essence, are the dynamic wiring (connections) of the neural network circuitry. Given the high complexity of the neural circuitry in the human brain, it is quite a challenge to study the dynamic wiring of highly parallel and widely distributed neural networks. The measurements of stimulus evoked coherent oscillations provide indirect evidence of dynamic wiring. In this study, in addition to the coherent oscillation measurements, two more techniques are discussed for testing possible dynamic wiring: measurements of spatio-temporal interactions beyond the classical receptive fields, and neural structural testing using nonlinear systems analysis.

The human luminance spatial frequency contrast sensitivity function (CSF) has been well studied using psychophysical measurements by detecting spatial frequency (SF) grating patterns at threshold. Threshold CSFs at different eccentricities have proven to be quite useful in both basic and clinical vision research. However, near threshold, the CSF is measured at a linear area of the saturating contrast-response curve. In contrast, most of our everyday vision may be at suprathreshold levels, and thus may function most of the time at the nonlinear area of the contrast-response curve. In this study, in order to better characterize the CSF at normal contrast levels, we measured the SF tuning functions as well as the CR functions at different suprathreshold contrast levels and different eccentricities of the visual field using noninvasive MEG techniques. In this study, in addition to peak analysis, we have developed more reliable averaged power analysis methods where the average power can be calculated from the entire waveforms.

Neutron detectors are commonly used by the nuclear materials processing industry to monitor fissile materials in process vessels and tanks. The proper functioning of these neutron monitors must be periodically evaluated. We have developed and placed in routine use a PC-based multichannel analyzer (MCA) system for on-line BF3 and He-3 gas-filled detector function testing. The automated system: 1) acquires spectral data from the monitor system, 2) analyzes the spectrum to determine the detector`s functionality, 3) makes suggestions for maintenance or repair, as required, and 4) saves the spectrum and results to disk for review. The operator interface has been designed to be user-friendly and to minimize the training requirements of the user. The system may also be easily customized for various applications

The Savannah River Site`s Defense Waste Processing Facility (DWPF) near Aiken, SC is the nation`s first and world`s largest vitrification facility. Following a ten year construction period and nearly 3 year non-radioactive test program, the DWPF began radioactive operations in March, 1996. The results of the first 8 months of radioactive operations are presented. Topics include facility production from waste preparation batching to canister filling.

Tensile creep-rupture of a commercial gas pressure sintered Si3N4 and a sintered SiC is examined at 1038, 1150, and 1350 C. These 2 ceramics are candidates for nozzles and combustor tiles that are to be retrofitted in land-based gas turbine engines, and there is interest in their high temperature performance over service times {ge} 10,000 h (14 months). For this long lifetime, a static tensile stress of 300 MPa at 1038/1150 C and 125 Mpa at 1350 C cannot be exceeded for Si3N4; for SiC, the corresponding numbers are 300 Mpa at 1038 C, 250 MPa at 1150 C, and 180 MPa at 1350 C. Creep-stress exponents for Si3N4 are 33, 17, and 8 for 1038, 1150, 1350 C; fatigue- stress exponents are equivalent to creep exponents, suggesting that the fatigue mechanism causing fracture is related to the creep mechanism. Little success was obtained in producing failure in SiC after several decades of time through exposure to appropriate tensile stress; if failure did not occur on loading, then the SiC specimens most often did not creep-rupture. Creep-stress exponents for the SiC were determined to be 57, 27, and 11 for 1038, 1150, and 1350 C. For SiC, the fatigue-stress exponents …

Metalorganic chemical vapor deposition was used to prepare epitaxial or highly oriented PLT (Pb{sub 1-x}La{sub x}TiO{sub 3}) thin films with x = 0.21-0.34. The growth of PLT films resulted in 3-D epitaxial heterostructures on a (100) surface of both MgO and KTaO{sub 3} substrates. The PLT film grown on a KTaO{sub 3} (100) substrate has a significantly lower minimum channeling yield compared to that grown on the MgO (100) substrate because of the smaller lattice mismatch associated with KTaO{sub 3}. Thickness and refractive indices at 435-1523 nm were measured by prism coupling. Measured film thickness of 570 nm was in good agreement with that obtained from RBS. Refractive index of the PLT film is smaller than that of PbTiO{sub 3}, and its difference at {lambda} = 632.8 nm is about 2.5%. Dispersion of the refractive index was well fitted by a Sellmeier dispersion formula.