A study is being conducted at NASA Lewis Research Center to determine the feasibility of using a carbide particle strengthened Nb-1% Zr base alloy to meet the anticipated temperature and creep resistance requirements of proposed near term space power systems. In order to provide information to aid in the determination of the suitability of the PWC-11 alloy as an alternative to Nb-1% Zr in space power systems this study investigated (1) the long-time high-vacuum creep behavior of the PWC-11 material and the Nb-1% Zr alloy, (2) the effect of prior stress-free thermal aging on this creep behavior, (3) the effect of electron beam (EB) welding on this creep behavior, and (4) the stability of creep strengthening carbide particles. 14 refs., 5 figs., 2 tabs.

The diffusion length of positrons has been measured in liquid and solid gallium and bismuth using a vertical positron beam. For Ga our results indicate a drop in the diffusion length from 1200 (100) {Angstrom} to 30 (5) {Angstrom} as the sample melts, as the temperature is increased there is a surprising increase in the diffusion length. At the melting point the annihilation parameter S in the bulk increases sharply, and stays constant with temperature, which indicates that vacancy size trapping centers exist in the liquid. For Bi, the diffusion length drops in the liquid from 500 {Angstrom} to 200 {Angstrom}, and increases slightly as the temperature is increased. This drop is interpreted in terms of increased scattering with Bi ions. A small change is observed in bulk S, indicating no trapping of positrons as the sample melts. This behaviour, which is so different in these two metals, indicates the sensitivity of positrons to the liquid structure. 6 refs., 2 figs.

A bench-scale reactor is being used to conduct studies of the conversion of synthesis gas to methanol by a novel process. During the last quarter, the effect of potassium methoxide and Cu-chromite loading on the MeOH formation rate was investigated. The rate obtained with Cu-chromite was compared to that using Cu-ZnO as catalyst. Work also continued on the modification of the experimental equipment to permit on-line monitoring of liquid and gas compositions.

A three-year research program for the development of novel XUV spectroscopic diagnostics for magnetically confined fusion plasmas is proposed. The new diagnostic system will use layered synthetic microstructures (LSM) coated, flat and curved surfaces as dispersive elements in spectrometers and narrow band XUV filter arrays. In the framework of the proposed program we will develop impurity monitors for poloidal and toroidal resolved measurements on PBX-M and Alcator C-Mod, imaging XUV spectrometers for electron density and temperature fluctuation measurements in the hot plasma core in TEXT or other similar tokamaks and plasma imaging devices in soft x-ray light for impurity behavior studies during RF heating on Phaedrus T and carbon pellet ablation in Alcator C-Mod. Recent results related to use of multilayer in XUV plasma spectroscopy are presented. We also discuss the latest results reviewed to q{sub o} and local poloidal field measurements using Zeeman polarimetry.

A process and apparatus for extruding a superconducting metal oxide composition YBa{sub 2}Cu{sub 3}O{sub 7-x} provides a wire (tube or ribbon) having a cohesive mass and a degree of flexibility together with enhanced electrical properties. Wire diameters in the range of 6--85 mils have been produced with smaller wires on the order of 10 mils in diameter exhibiting enhanced flexibility for forming braided, or multistrand, configurations for greater current carrying capacity. The composition for extrusion contains a polymeric binder to provide a cohesive mass to bind the particles together during the extrusion process with the binder subsequently removed at lower temperatures during sintering. The composition for extrusion further includes a deflocculent, an organic plasticizer and a solvent which also are subsequently removed during sintering. Electrically conductive tubing with an inner diameter of 52 mil and an outer diameter of 87--335 mil has also been produced. Flat ribbons have been produced in the range of 10--125 mil thick by 100--500 mil wide. The superconducting wire, tube or ribbon may include an outer ceramic insulating sheath co-extruded with the wire, tubing or ribbon.

Low photo desorption (PSD) from surfaces of vacuum chambers increases the beam lifetime and reduces the cost of the pumping system of any storage ring. In compact rings where all radiated power ({approximately}10 kW) is incident on a few meters only, low PSD and good thermal conductivity of photon absorbers are of particular importance. An experimental chamber in which one meter long bars can be exposed to white photon beam with 500 eV critical energy has been built and installed on the U10B beamline in the VUV ring at the NSLS. Several reference bars made of high purity copper and a TiN coating on copper have been measured. Subsequent runs will include gold coating on copper, aluminum (200{degree}C baked), diamond coating on copper and uncoated beryllium bars. In this paper the desorption coefficients will be measured and compared. 6 refs., 4 figs.

System owners and operators are increasingly emphasizing the actual amount of time equipment is capable of performing its intended function. For military systems, added complexity, longer service life requirements, reduced periodic maintenance, and less frequent checkouts are increasing system availability requirements. However, these factors compound the difficulty in estimating the system's true availability. With dormant or semi-dormant systems, the amount of time a system appears'' available may differ form the real'' availability. The difference in real'' and apparent'' availability is often the result of a transition from an operational but dormant state to an inoperational but dormant state. The major contributions from this research are: the development of the concept of complex'' availability that applies to systems which combine two or more elements of instantaneous, mission system, or steady-state availability; and the development of modeling technique to estimate the real'' availability for a system which involves complex'' availability. 28 refs., 2 figs.

Approximately 2,000 m{sup 3} of liquid containing radioactive and chemical wastes leaked from the 241-T-106 single-shell tank at the Hanford Site. The leak discharged into the unsaturated, coarse-grained sediments of the Hanford formation which underlie the base of the tank. The PORFLO-3 computer code was used to study plume migration for {sup 106}Ru and {sup 137}Cs. The flow and transport properties of the soils through which the plume has migrated are critical input data for the model but are not available. Information from a catalogue of Hanford Site soil properties was used. The transient magnitudes and locations of the plume were simulated in three dimensions. Using the reduced vertical hydraulic conductivity, the migration of {sup 106}Ru and {sup 137}Cs was simulated for the time between 1973 and 1990. 24 refs., 33 figs., 3 tabs.

This paper is documentation of a video presentation and provides a brief summary of the Virginia power/US Department of Energy Cooperative Cask Testing/Demonstration Program. The program consists of two phases. The first phase has been completed and involved the unlicensed performance testing (heat transfer and shielding) of three metal spent fuel storage casks at the federally owned Idaho National Engineering Laboratory. The second phase is ongoing and consists of licensed demonstrations of standard casks from two different vendors and of one or two enhanced capacity casks. 6 refs., 1 tab.

Design requirements for a visible wavelength free-electron laser being developed at the Accelerator Test Facility at Brookhaven National Laboratory are presented along with predictions of laser performance from 3-D numerical simulations. The design and construction of the optical resonator, its alignment and control systems are also described. 15 refs., 8 figs., 4 tabs.

This invention relates to a thermal storage apparatus and more particularly to an apparatus for use in conjunction with solar dynamic energy storage systems. The invention is comprised of a thermal energy storage system comprising a germanium phase change material and a graphite container.

Bench-scale and pilot-scale experiments have been conducted to measure the mass transfer and kinetic rates at simulated duct injection conditions. Section 2 describes the tank reactor test results. The stirred tank reactor was used to study absorption of SO{sub 2} into saturated Ca(OH){sub 2} solutions with varied ionic strengths. The results of current experiments were compared with previous tests using saturated Ca(OH){sub 2} solution and 0.1 M CaCl{sub 2}. Section 3 summarizes the status of the Short-Time Differential Reactor (STDR) tests for Task 2.3. The effect of CO{sub 2} on reactivity of Mississippi Ca(OH){sub 2} with SO{sub 2} was investigated. The extent of carbonation was measured for a commercial Mississippi Ca(OH){sub 2} and laboratory-produced sorbents. Section 4 presents pilot plant testing conducted to evaluate various operating conditions and process schemes to support large-scale field testing at Meredosia and Beverly (Task 3). Consistent data were obtained from pilot testing of in-duct dry injection downstream of the humidifier. Section 5 reports differential reactor (Task 4) tests. The differential reactor has been modified to determine the effect of initial water content on the sorbent reactivity. An experimental method has been developed to prepare solid samples containing reproducible, predictable quantities of water. The experiments …

The US Department of Energy's Pittsburgh Energy Technology Center (PETC) is actively pursuing the development and testing of coal-fired combustion systems for residential, commercial, and industrial market sectors. In response, MTCI initiated the development of a new combustor technology based on the principle of pulse combustion under the sponsorship of PETC (Contract No. AC22-83PC60419). The initial pulse combustor development program was conducted in three phases (MTCI, Development of a Pulsed Coal Combustor Fired with CWM, Phase III Final Report, DOE Contract No. AC22-83PC60419, November 1986). Phase I included a review of the prior art in the area of pulse combustion and the development of pulse combustor design concepts. It led to the conclusion that pulse combustors offer technical and base-of-operation advantages over conventional burners and also indicated favorable economics for replacement of oil- and gas-fired equipment.

Transit time, the time from bridgewire burst until breakout of detonation from the output pellet of an exploding bridgewire detonator, was measured as a function of burst current. From this data, in conjunction with known equations for run distance versus pressure, unreacted explosive Hugoniots, and detonation properties of the initial pressing pellet, the run distance in the initial pressing explosive pellet and shock pressure from the exploding bridgewire were determined, both as a function of burst current.

The use of depleted uranium (DU) penetrators as armor-piercing projectiles in the field results in the release of uranium into the environment. Elevated levels of uranium in the environment are of concern because of radioactivity and chemical toxicity. In addition to the direct contamination of the soil with uranium, the penetrators will also chemically react with rainwater and surface water. Uranium may be oxidized and leached into surface water or groundwater and may subsequently be transported. In this report, we review some of the factors affecting the oxidation of the DU metal and the factors influencing the leaching and mobility of uranium through surface water and groundwater pathways, and the uptake of uranium by plants growing in contaminated soils. 29 refs., 10 figs., 3 tabs.

The goal of this project is to understand at the molecular level how phytochrome functions and how intracellular proteins are degraded. Phytochrome is marked for degradation by covalent attachment of ubiquitin. Ubiquitin-phytochrome conjugates (UbP) were characterized with respect to formation kinetics, subcellular localization and site of ubiquitin attachment. UbP appears to be a general phenomenon during phytochrome degradation in a variety of species. UbP was isolated from oat seedlings and characterized. Residues 747-830 of phytochrome have been identified as a possible attachment site for ubiquitin. By placing the gene for etiolated phytochrome in tobacco we have created a transgenic system for over expressing phytochrome. The effects of this over expression are described, and it appears that tobacco degrades this foreign protein through formation of UbP. We have created a series of site-directed mutants of the oat phytochrome gene, and are in the process of characterizing them to determine sequence requirements for ubiquination. 8 refs., 1 fig. (MHB)

This project is designed to develop methods for pre-combustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic solvent. Enzymes from commercial sources or microbial extracts are being investigated for their capacity to remove organic sulfur from coal by oxidation of the sulfur groups, splitting of C-S bonds and loss of sulfur as sulfuric acid Dibenzothiophene (DBT) and ehtylphenylsulfide (EPS)are serving as serving as models of organic sulfur-containing components of coal in initial studies.

Characteristics of J/{psi} and {Upsilon} produced at the Tevatron and detected in the dimuon channel at CDF are reviewed. The masses of the J/{psi} and {Upsilon} are measured to be 3.096 {plus minus} 0.001 GeV/c{sup 2} and 9.469 {plus minus} 0.010 GeV/c{sup 2} respectively. These mass measurements are used to determine the systematic uncertainty on the momentum scale in the central tracking chamber. 2 refs., 14 figs.

This report discusses research on the following topics: high-{Tc} superconductors; The response of crystal to an applied electric field; quasicrystals; surface structure and kinetics of surface layer formation; EXAFS studies of superconductors and heterostructures; effect of iron on the crystal structure of perovskite; x-ray detector development; and SAXS experiments. (LSP)

The objective of this program is to investigate the direct conversion of light gaseous hydrocarbons, such as those produced during Fischer-Tropsch synthesis or as a product of gasification, to liquid transportation fuels via a partial oxidation process. The process will be tested in an existing pilot plant to obtain credible mass balances. Specific objectives to be met include determination of optimal process conditions, investigation of various processing options (e.g. feed injection, product quench, and recycle systems), and evaluation of an enhanced yield thermal/catalytic system. Economic evaluation of the various options will be performed as experimental data become available.

Accelerator-based neutron sources for R D of materials in nuclear energy systems, including fusion reactors, can provide sufficient neutron flux, flux-volume, fluence and other attractive features for many aspects of materials research. The neutron spectrum produced from the D-Li reaction has been judged useful for many basic materials research problems, and to be a satisfactory approximation to that of the fusion process. The technology of high-intensity linear accelerators can readily be applied to provide the deuteron beam for the neutron source. Earlier applications included the Los Alamos Meson Physics Facility and the Fusion Materials Irradiation Test facility prototype. The key features of today's advanced accelerator technology are presented to illustrate the present state-of-the-art in terms of improved understanding of basic physical principles and engineering technique, and to show how these advances can be applied to present demands in a timely manner. These features include how to produce an intense beam current with the high quality required to minimize beam losses along the accelerator and transport system that could cause maintenance difficulties, by controlling the beam emittance through proper choice of the operating frequency, balancing of the forces acting on the beam, and realization in practical hardware. A most interesting aspect …

To better understand the flotation behavior of coal pyrite, studies have been initiated to characterize the floatability of coal pyrite and mineral pyrite. The hydrophobicity of coal material pyrite was examined over a range of pH and oxidation times. The results indicate that surface oxidation plays an important role in coal and mineral pyrite hydrophobicity. The hydrophobicity of mineral pyrite decreases with increasing oxidation time (20 min. to 5 hr.) and increasing pH (pH 4.6 to 9.2), with maximum depression occurring at pH 9.2. However, coal pyrite exhibited low floatability, even at the lowest oxidation time, over the entire pH range. X-ray photoelectron spectroscopy (XPS) results suggest the growth of an oxidized iron layer as being responsible for the deterioration in floatability, while a sulfur-containing species present on the sample surfaces may promote floatability. Preliminary studies of the effect of frother indicate an enhancement in the floatability of both coal and mineral pyrite over the entire pH range.

This report summarizes the International Conference on Fusion Reactor Materials (ICFRM-4) which was held December 4--9, 1989, in Kyoto, Japan, as well as the results of several workshops, planning meetings, and laboratory visits made by the travelers. The ICFRM-4 is the major forum to present and exchange information on materials research and development in support of the world's fusion development efforts. About 360 papers were presented by the 347 conference attendees. Highlights of the conference are presented. A proposal by the United States to host ICFRM-5 was accepted by the International Advisory Committee. ORNL will be the host laboratory. A meeting of the DOE/JAERI Annex I Steering Committee to review the US/Japan Collaborative Testing of First Wall and Blanket Structural Materials with Mixed Spectrum Fission Reactors was held at JAERI Headquarters on December 1. The Japanese emphasized the critical importance of a resumption of HFIR operation. Even though the HFIR outage has lasted three plus years this program has continued to provide new and important data on materials behavior which has particular relevance to ITER.

The marginal performer -- an employee who is not meeting performance standards established in the performance appraisal process -- is a fact of life that most supervisors eventually have to face. Screening of job applicants can reduce the number of employees with skill or performance difficulties, but problems can arise even with the most carefully chosen employee. They can also develop in people who were once productive.