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A phase II 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 sixth quarter of work. The major accomplishments were (1) Completion of the distillation of the liquid product from coal liquefaction autoclave reactor runs with Illinois No. 6 coal at 400{degree}C, with and without surfactant and/or catalyst at pressures of 1700 psig, (2) Batch autoclave runs at 375 and 400{degree}C with 1 wt % lignin to Illinois No. 6 coal to further define the surfactant effect of sodium lignosulfonate, and (3) a preliminary economic evaluation of the application of the lignosulfonate surfactant in an industrial liquefaction process and a proposed conceptual plant design.

The vision for the future of the planetary exploration program includes the capability to deliver {open_quotes}constellations{close_quotes} or {open_quotes}fleets{close_quotes} of microspacecraft to a planetary destination. These fleets will act in a coordinated manner to gather science data from a variety of locations on or around the target body, thus providing detailed, global coverage without requiring development of a single large, complex and costly spacecraft. Such constellations of spacecraft, coupled with advanced information processing and visualization techniques and high-rate communications, could provide the basis for development of a {open_quotes}virtual{close_quotes} {open_quotes}presence{close_quotes} in the solar system. A goal could be the near real-time delivery of planetary images and video to a wide variety of users in the general public and the science community. This will be a major step in making the solar system accessible to the public and will help make solar system exploration a part of the human experience on Earth.

Concern over the future availability of high quality liquid fuels or use in furnaces and boilers prompted the U. S. Department of Energy (DOE) to consider alternate fuels as replacements for the high grade liquid fuels used in the 1970`s and 1980`s. Alternate fuels were defined to be combinations of a large percentage of viscous, low volatility fuels resulting from the low end of distillation mixed with a small percentage of relatively low viscosity, high volatility fuels yielded by the high end of distillation. The addition of high volatility fuels was meant to promote desirable characteristics to a fuel that would otherwise be difficult to atomize and burn and whose combustion would yield a high amount of pollutants. Several questions thus needed to be answered before alternate fuels became commercially viable. These questions were related to fuel atomization, evaporation, ignition, combustion and pollutant formation. This final report describes the results of the most significant studies on ignition and combustion of alternative fuels.

A search was made for improved TE materials that could have higher efficiency than state-of-the-art SiGe alloys used in Radioisotope Thermoelectric Generators. A new family of materials having the skutterudite structure was identified (cubic space group Im3, formula (Fe, Co, Ni)As{sub 3}). Properties of n-type IrSb{sub 3}, CoSb{sub 3}, and their solid solutions were investigated. Pt, Te, Tl, and In were used as dopants. The thermal conductivity was reduced by about 70% for the solid solutions vs the binary compounds. A maximum ZT of about 0.36 was measured on Co-rich solid solutions which is 160% improved over that of the binary compounds.

We have found that there is a limited range of solid solutions between the skutterudite compounds CoSb{sub 3} and RuSb{sub 2}Te (about 5% on each side). For the system (RuSb{sub 2}Te){sub x}(CoSb{sub 3}){sub 1-x}, preliminary results obtained on one n-type sample on the CoSb{sub 3}-rich side show that these alloys have good thermoelectric properties and a maximum ZT of about 0.89 was obtained at about 600 C. More experiments will be started to investigate the possibility of a broader range of miscibility in this system which would allow an even further decrease in the lattice thermal conductivity, resulting in better thermoelectric properties. IrSb{sub 3} and RuSb{sub 2}Te form a complete range of solid solutions. Hot-pressed samples in this system have shown p-type conductivity. The thermoelectric properties of these p-type alloys have been measured and results have shown that their potential for thermoelectric applications is limited mainly because of the relatively low Seebeck coefficient values for p-type materials. Efforts will be directed on preparing n-type samples of the same alloys by doping with various dopants such as Ni and Pd.

The overall objective of the Direct Conversion Technology task is to develop an experimentally verified technology base for promising direct conversion systems that have potential application for energy conservation in the end-use sectors. Initially, two systems were selected for exploratory research and advanced development. These are Alkali Metal Thermal-to-Electric Converter (AMTEC) and Two-Phase Liquid Metal MD Generator (LMMHD). This report describes progress that has been made during the first six months of 1992 on research activities associated with these two systems. (GHH)

Transport of alkali metal atoms through porous cathodes of alkali metal thermal-to-electric converter (AMTEC) cells is responsible for significant, reducible losses in the electrical performance of these cells. Experimental evidence for activated transport of metal atoms at grain surfaces and boundaries within some AMTEC electrodes has been derived from temperature dependent studies as well as from analysis of the detailed frequency dependence of ac impedance results for other electrodes, including thin, mature molybdenum electrodes which exhibit transport dominated by free molecular flow of sodium gas at low frequencies or dc conditions. Activated surface transport will almost always exist in parallel with free molecular flow transport, and the process of alkali atom adsorption/desorption from the electrode surface will invariably be part of the transport process, and possibly a dominant part in some cases. Little can be learned about the detailed mass transport process from the ac impedance or current voltage curves of an electrode at one set of operating parameters, because the transport process includes a number of important physical parameters that are not all uniquely determined by one experiment. The temperature dependence of diffusion coefficient of the alkali metal through the electrode in several cases provides an activation energy and …

The objective of this multiyear effort was the development, fabrication and testing of a zirconia oxygen production module capable of delivering approximately 100 liters/minute (LPM) of oxygen. The work discussed in this report consists of development and improvement of the zirconia cell along with manufacture of cell components, preliminary design of the final plant, additional economic analysis and industrial participation. (VC)

The overall objective of the Direct Conversion Technology task is to develop an experimentally verified technology base for promising direct conversion systems that have potential application for energy conservation in the end-use sectors. This report contains progress of research on the Alkali Metal Thermal-to-Electric Converter (AMTEC) and on the Two-Phase Liquid-Metal MHD Electrical Generator (LMMHD) for the period January 1, 1991 through December 31, 1991. Research on AMTEC and on LMMHD was initiated during October 1987. Reports prepared on previous occasions (Refs. 1--5) contain descriptive and performance discussions of the following direct conversion concepts: thermoelectric, pyroelectric, thermionic, thermophotovoltaic, thermoacoustic, thermomagnetic, thermoelastic (Nitionol heat engine); and also, more complete descriptive discussions of AMTEC and LMMHD systems.

Long lifetimes are required for AMTEC (or sodium heat engine) components for aerospace and terrestrial applications, and the high heat input temperature as well as the alkali metal liquid and vapor environment places unusual demands on the materials used to construct AMTEC devices. In addition, it is important to maximize device efficiency and power density, while maintaining a long life capability. In addition to the electrode, which must provide both efficient electrode kinetics, transport of the alkali metal, and low electrical resistance, other high temperature components of the cell face equally demanding requirements. The beta{double prime} alumina solid electrolyte (BASE), the seal between the BASE ceramic and its metallic transition to the hot alkali metal (liquid or vapor) source, and metallic components of the device are exposed to hot liquid alkali metal. Modification of AMTEC components may also be useful in optimizing the device for particular operating conditions. In particular, a potassium AMTEC may be expected to operate more efficiently at lower temperatures.

The purpose of the following computer study is to determine the set of necessary conditions under which the addition of photo-voltaic (PV) cells to electric vehicles provides a net utility or economic benefit. Economic benefits are given the primary focus and are evaluated in terms of a payback period.

A phase II 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 second quarter of work. The major accomplishments were (1) completion of coal liquefaction autoclave reactor runs with Illinois No. 6 coal at processing temperatures of 300, 325, and 350[degrees]C, and pressures of 1800 psig, (2) analysis of the filter cake and the filtrate obtained from the treated slurry in each run, and (3) correlation of the coal conversions and the liquid yield quality to the surfactant concentration. An increase in coal conversions and upgrading of the liquid product quality due to surfactant addition was observed for all runs.

A phase II study has been initiated to investigate surfactant-assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This publication covers the first quarter of work. The major accomplishments were: (1) the refurbishment of the high-pressure, high-temperature reactor autoclave, (2) the completion of four coal liquefaction runs with Pittsburgh [number sign]8 coal, two each with and without sodium lignosulfonate surfactant, and (3) the development of an analysis scheme for the product liquid filtrate and filter cake. Initial results at low reactor temperatures show that the addition of the surfactant produces an improvement in conversion yields and an increase in lighter boiling point fractions for the filtrate.

A phase II 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 fifth quarter of work. The major accomplishments were: (1) Completion of coal liquefaction autoclave reactor runs and related analysis with Illinois no. 6 coal at 400{degrees}C with and without surfactant and/or catalyst at pressures of 1700 psig; (2) A literature search into the effect that lignin has in the coprocessing of coal; and (3) Presentation of a report summarizing the first year of work on this task at the Annual Liquefaction Contractors Review Conference. Results from this quarter show that lignosulfonate surfactant continues to increase overall MAF conversion of Illinois no. 6 coal at temperatures up to 400{degrees}C and produces an improvement in light boiling fraction distillate over the base case of no surfactant addition.

The objective of this multiyear effort was the development, fabrication and testing of a zirconia oxygen production module capable of delivering approximately 100 liters/minute (LPM) of oxygen. The work discussed in this report consists of development and improvement of the zirconia cell along with manufacture of cell components, preliminary design of the final plant, additional economic analysis and industrial participation. (VC)

This study has been made to assess the needs, potential benefits and the applicability of early (circa year 2000) Nuclear Electric Propulsion (NEP) technology in conducting NASA science missions. The study goals are: to obtain the performance characteristics of near term NEP technologies; to measure the performance potential of NEP for important OSSA missions; to compare NEP performance with that of conventional chemical propulsion; to identify key NEP system requirements; to clarify and depict the degree of importance NEP might have in advancing NASA space science goals; and to disseminate the results in a format useful to both NEP users and technology developers. This is a mission performance study and precludes investigations of multitudes of new mission operation and systems design issues attendant in a NEP flight.

The overall objective of the Direct Conversion Technology task is to develop an experimentally verified technology base for promising direct conversion systems that have potential application for energy conservation in the end-use sectors. This report contains progress of research on the Alkali Metal Thermal-to-Electric Converter (AMTEC) and on the Two-Phase Liquid-Metal MHD Electrical Generator (LMMHD) for the period January 1, 1991 through December 31, 1991. Research on AMTEC and on LMMHD was initiated during October 1987. Reports prepared on previous occasions (Refs. 1--5) contain descriptive and performance discussions of the following direct conversion concepts: thermoelectric, pyroelectric, thermionic, thermophotovoltaic, thermoacoustic, thermomagnetic, thermoelastic (Nitionol heat engine); and also, more complete descriptive discussions of AMTEC and LMMHD systems.

The Pasadena Workshop on System Software and Tools for High Performance Computing Environments was held at the Jet Propulsion Laboratory from April 14 through April 16, 1992. The workshop was sponsored by a number of Federal agencies committed to the advancement of high performance computing (HPC) both as a means to advance their respective missions and as a national resource to enhance American productivity and competitiveness. Over a hundred experts in related fields from industry, academia, and government were invited to participate in this effort to assess the current status of software technology in support of HPC systems. The overall objectives of the workshop were to understand the requirements and current limitations of HPC software technology and to contribute to a basis for establishing new directions in research and development for software technology in HPC environments. This report includes reports written by the participants of the workshop`s seven working groups. Materials presented at the workshop are reproduced in appendices. Additional chapters summarize the findings and analyze their implications for future directions in HPC software technology development.

We have implemented a 2D electrostastic plasma particle in cell (PIC) simulation code on the Caltech/JPL Mark IIIfp Hypercube. The code simulates plasma effects by evolving in time the trajectories of thousands to millions of charged particles subject to their self-consistent fields. Each particle`s position and velocity is advanced in time using a leap frog method for integrating Newton`s equations of motion in electric and magnetic fields. The electric field due to these moving charged particles is calculated on a spatial grid at each time by solving Poisson`s equation in Fourier space. These two tasks represent the largest part of the computation. To obtain efficient operation on a distributed memory parallel computer, we are using the General Concurrent PIC (GCPIC) algorithm previously developed for a 1D parallel PIC code.

Dynamic load balancing has been implemented in a concurrent one-dimensional electromagnetic plasma particle-in-cell (PIC) simulation code using a method which adds very little overhead to the parallel code. In PIC codes, the orbits of many interacting plasma electrons and ions are followed as an initial value problem as the particles move in electromagnetic fields calculated self-consistently from the particle motions. The code was implemented using the GCPIC algorithm in which the particles are divided among processors by partitioning the spatial domain of the simulation. The problem is load-balanced by partitioning the spatial domain so that each partition has approximately the same number of particles. During the simulation, the partitions are dynamically recreated as the spatial distribution of the particles changes in order to maintain processor load balance.

Long lifetimes are required for AMTEC (or sodium heat engine) components for aerospace and terrestrial applications, and the high heat input temperature as well as the alkali metal liquid and vapor environment places unusual demands on the materials used to construct AMTEC devices. In addition, it is important to maximize device efficiency and power density, while maintaining a long life capability. In addition to the electrode, which must provide both efficient electrode kinetics, transport of the alkali metal, and low electrical resistance, other high temperature components of the cell face equally demanding requirements. The beta{double_prime} alumina solid electrolyte (BASE), the seal between the BASE ceramic and its metallic transition to the hot alkali metal (liquid or vapor) source, and metallic components of the device are exposed to hot liquid alkali metal. Modification of AMTEC components may also be useful in optimizing the device for particular operating conditions. In particular, a potassium AMTEC may be expected to operate more efficiently at lower temperatures.

A phase II 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 second quarter of work. The major accomplishments were (1) completion of coal liquefaction autoclave reactor runs with Illinois No. 6 coal at processing temperatures of 300, 325, and 350{degrees}C, and pressures of 1800 psig, (2) analysis of the filter cake and the filtrate obtained from the treated slurry in each run, and (3) correlation of the coal conversions and the liquid yield quality to the surfactant concentration. An increase in coal conversions and upgrading of the liquid product quality due to surfactant addition was observed for all runs.

Cellulase (CBHI) was modified by bis (2,2- bipyridine) ruthenium (II) and the modified enzyme was assayed for cellulase activity using p- nitrophenyl beta-D-cellobioside as substrate. Absorption spectroscopy of native and modified CBHI was also conducted.