In work carried out on this project, the usual mathematical modeling of ultrasonic wave scattering by flaws is being extended to account for several typical characteristics of fatigue and stress-corrosion cracks, and the environment of such cracks. Work has been completed on scattering by macrocrack-microcrack configurations. We have also investigated reflection and transmission by a flaw plane consisting of an infinite array of randomly oriented cracks. In another investigation the propagation of mechanical disturbances in solids with periodically distributed cracks has been studied.

In work carried out on this project, the usual mathematical modeling of ultrasonic wave scattering by flaws is being extended to account for several typical characteristics of fatigue and stress-corrosion cracks, and the environment of such cracks. Work has been completed on scattering by macrocrack-microcrack configurations. We have also investigated reflection and transmission by a flaw plane consisting of an infinite array of randomly oriented cracks. In another investigation the propagation of mechanical disturbances in solids with periodically distributed cracks has been studied.

In inertial confinement fusion (ICF) experiments, the high electromagnetic fields propagating through a relatively dense plasma can result in a transverse instability, causing the matter and light to form filaments oriented parallel to the light beam. We examine whether a similar instability exists in the electron beam of a free-electron laser, where such an instability could interfere with the transfer of beam kinetic energy into optical wave energy. We heuristically examine the instability in a relativistic beam through which an intense laser beam is propagating. We ignore the FEL effects. We estimate how the altered index of refraction in an FEL affects the dispersion relation. Finally, we estimate the effect that the instability could have on the phase coherence of a particle as it transits an FEL. 10 refs., 2 tabs.

Gaseous acid treatment (HBr) of surface-hardened binary glass microballoons results in etching and the growth of salt nodules, tubes or whiskers, depending on moisture conditions. Temperatures from 400/sup 0/C to 625/sup 0/C for 24 h or more are required for the effects to be significant. Numerous imperfections, including craters, are documented on the unexposed interiors surfaces. The evident phase separation and nucleation sites suggest a need for better production controls and post-production annealing. 6 figures.

The objective of the decontamination effort was to place the Radioactive Materials Disposal Facility (RMDF) leach field in a condition suitable for release for unrestricted use. Radioactively contaminated soil was excavated from the leach field to produce a condition of contamination as low as reasonably achievable (ALARA). The contaminated soil was boxed and shipped to an NRC-licensed burial site at Beatty, Nevada, and to the DOE burial site at Hanford, Washington. The soil excavation project successfully reduced the contamination level in the leach field to background levels, except for less than 0.6 mCi of Sr-90 and trace amounts of Cs-137 that are isolated in cracks in the bedrock. The cracks are greater than 10 ft below the surface and have been sealed with a bituminous asphalt mastic. A pathways analysis for radiation exposure to humans from the remaining radionuclides was performed, assuming intensive home gardening, and the results show that the total first year whole body dose equivalent would be about 0.1 mrem/year. This dose equivalent is a projection for the hypothetical ingestion of vegetables grown on the site. Assuming that an average adult consumes 64 kg of green leafy vegetables per year and that the entire yearly supply could …

Constant extension rate tests (CERT) were run on ten irradiated specimens in continuation of a study of environmental effects on intergranular stress corrosion cracking of type 304 stainless steel. Specimens of both furnace sensitized and annealed material were irradiated to fluences of 1 to 2 {times} 10{sup 21} neutrons (E {ge} 0.1 Mev) per square centimeter at a temperature of {approximately}150{degree}C in a reflector position of the High Flux Isoptope Reactor at ORNL. CERT test conditions duplicated conditions for testing of non-irradiated specimens. The time-to-failure for the sensitized and irradiated specimens showed the same pattern of dependence on test variables as the non-irradiated specimens in an associated study. The annealed and irradiated specimens showed no evidence of irradiation assisted stress corrosion cracking.

Constant extension rate tests (CERT) were run on ten irradiated specimens in continuation of a study of environmental effects on intergranular stress corrosion cracking of type 304 stainless steel. Specimens of both furnace sensitized and annealed material were irradiated to fluences of 1 to 2 {times} 10{sup 21} neutrons (E {ge} 0.1 Mev) per square centimeter at a temperature of {approximately}150{degree}C in a reflector position of the High Flux Isoptope Reactor at ORNL. CERT test conditions duplicated conditions for testing of non-irradiated specimens. The time-to-failure for the sensitized and irradiated specimens showed the same pattern of dependence on test variables as the non-irradiated specimens in an associated study. The annealed and irradiated specimens showed no evidence of irradiation assisted stress corrosion cracking.

The overall objective of this research is to design, synthesize, and evaluate cyclic and polycyclic host organic compounds for the abilities to complex and lipophilize guest metal ions, their complexes, and their clusters. Host organic compounds consist of strategically placed solvating, coordinating, and ion-pairing sites tied together by covalent bonds through hydrocarbon units around cavities shaped to be occupied by guest metal ions, or by metal ions plus their ligands. Specificity in complexation is sought by matching the following properties of host and guest: cavity and metal ion sizes; geometric arrangements of binding sites; numbers of binding sites; characters of binding sites; and valences. The hope is to synthesize new classes of compounds useful in the separation of metal ions, their complexes, and their clusters.

An analysis is made of the rules implementing Sections 201 and 210 of the Public Utility Regulatory Policies Act of 1978 (PURPA). The act provides that utilities must purchase power from qualifying producers of electricity at nondiscriminatory rates, and it exempts private generators from virtually all state and Federal utility regulations. Most of the analysis presented is taken from the perspective of photovoltaics (PV) and solar thermal electric point-focusing distributed receivers (pfdr). It is felt, however, that the analysis is applicable both to cogeneration and other emerging technologies. Chapters presented are: The FERC Response to Oral Comments on the Proposed Rules Implementing Sections 201 and 210 of PURPA; Additional Changes Made or Not Made That Were Addressed in Other Than Oral Testimony; View on the Proposed Rules Implementing Sections 201 and 210 of PURPA; Response to Comments on the Proposed 201 and 210 Rules; and Summary Analysis of the Environmental Assessment of the Rules. Pertinent reference material is provided in the Appendices, including the text of the rules. (MCW)

To understand the evolution of giant stars, it is important to pin down the masses for Cepheids. The 7- to 10-day bump Cepheids imply lower than evolutionary mass (60%). Recent theoretical work, though, indicates that for Cepheids with periods of 15 to 16 days, the best understanding of the light curves results from using evolutionary masses.

Potential ridges, now identified as the locus of breakdown of approximate separability of coordinates, require a special physico-mathematical treatment the initial phase of which has now been completed. The role of a potential ridge in separating the pair of exit channels of lower-energy two-electron excitations is circumscribed and hence accessible to numerical calculations; it has thus been studied in some detail for earth-alkaline-like configurations and for He/sup -/. Quantum defect theory approaches have been extended to molecular predissociation and to the study of Stark effect wave-functions; these extensions have now proved so far from the origins of the approach that a new name and description would be more appropriate.

The conceptual design of a large superconducting solenoid suitable for a magnetic detector at the Superconducting Super Collider (SSC) was done at Fermilab. The magnet will provide a magnetic field of 1.7 T over a volume 8 m in diameter by 16 m long. The particle-physics calorimetry will be inside the field volume and so the coil will be bath cooled and cryostable; the vessels will be stainless steel. Predictability of performance and the ability to safely negotiate all probable failure modes, including a quench, are important items of the design philosophy. Our conceptual design of the magnet and calorimeter has convinced us that this magnet is a reasonable extrapolation of present technology and is therefore feasible. The principal difficulties anticipated are those associated with the very large physical dimensions and stored energy of the magnet. 5 figs.

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This report describes work completed, work in progress, and work planned during the continuation of funding. Research is being carried out on the following: bonded inclusions are being treated as problems of a homogeneous body; the problem of two cavities or inclusions is being studied; the examination of non-classical transformations is leading to conservation laws in statics and dynamics with applications in fracture and defect mechanics; mathematical and physical modeling of damage in brittle solids is being performed; a theoretical and numerical study of subsonic interfacial waves in bonded piezoelectric dissimilar half-spaces has been completed; the study of which crystal classes are capable of admitting the so-called Type 3 transonic state in anisotropic elasticity is also complete; and wave studies will be extended into the supersonic regime. The authors also intend to complete a study of the general self-force on a 3-dimensional dislocation loop element in an elastic medium of arbitrary anisotropy, as this is currently a needed ingredient in modern fracture and damage mechanics and in the study of defects in integrated circuit materials.

Field studies at the Nevada Test Site by researchers at Lawrence Livermore National Laboratory have demonstrated that radionuclides are being transported by colloidal material suspended in groundwater. This observation is counter to most predictions from contaminant transport models because the models assume adsorbed species are immobile. The purpose of this research is to quantify the transport processes for colloidal materials and develop the mechanistic understanding necessary to predict radionuclide transport in fractured media. There were three areas of investigation during this year that have addressed these issues: chemical control of colloid deposition on clean mineral surfaces, colloid accumulation on fracture surfaces, and the influence of deposited colloids on colloid and tracer migration. 7 refs.

In March, a workshop was held at Cornell University on the accelerator. The conclusion of this workshop was that a 20 TeV on 20 TeV proton-proton collider is technically feasable, that construction could begin after 2.5 to 4 years of research and development, and the cost would be 1.3 to 2 billion dollars. To put this machine into perspective one must consider the existing facilities listed in table I. There are about 23 high energy physics laboratories in the world that are being operated or constructed. Most of these labs have an effective energy of less than 100 GeV and study principally the known quarks and leptons. The only accelerator operating at an effective energy greater than 100 GeV is the CERN proton-antiproton system. As has been presented at this conference in other papers their success has been great in a very short time, the discovery of the vector bosons W and Z. The only machine approved that will have an effective energy greater than 1000 GeV is the Russian accelerator UNK. The effective energy of a 20 TeV on 20 TeV proton-proton collider would be about 15 TeV.

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The Hf implanted Ni system has been studied by the time-differential perturbed angular correlation (TDPAC) technique and by Rutherford backscattering (RBS)/channeling. Low fluence implants were thermally annealed in vacuum at increasing temperature in order to study the evolution of substitutional and defect-associated solutes using TDPAC. Both detrapping and precipitation (or segregation) effects have been observed. Higher fluence implants were studied by both TDPAC and RBS/channeling in as-implanted as well as laser-surface-melted regimes. 10 figures.

The oxidation of ion-implanted Ta in two different high temperature regimes has been studied. Oxidations were carried out at 500/sup 0/C in Ar/O/sub 2/ mixtures, where oxide growth is known to follow a parabolic rate law in initial stages, and at 1000/sup 0/C in pure O/sub 2/, where a linear-rate behavior obtains. Implanted species include Al, Ce, Cr, Li, Si and Zr at fluences of the order of 10/sup 17//cm/sup 2/. Oxidized samples were studied using Rutherford backscattering, nuclear reaction analysis, Auger spectroscopy, secondary-ion mass spectroscopy, x-ray diffraction and optical microscopy. Significant differences among the specimens were noted after the milder 500/sup 0/C treatment, specifically, in the amount of oxide formed, the degree of oxygen dissolution in the metal beneath the oxide, and in the redistribution behavior of the implanted solutes. Under the severe 1000/sup 0/C treatment, indications of different solute distributions and of different optical features were found, whereas overall oxidation rate appeared to be unaffected by the presence of the solute. 7 figures.

Equipment modifications to a Freon 11 boil-off type calorimeter are described. The calorimetric system was used to measure the enthalpies of thiophene experimentally. Data were taken over a temperature range of 100/sup 0/F to 750/sup 0/F at pressures of 50, 100, 200, 400, 600, 825.9 (the critical), 1000, and 1500 psia. Thermodynamic properties derived from the data are compared to values in the literature, and the agreement is exceptionally good. The data are then compared directly to results calculated by means of two correlations: a modification of the BWR equation of state by Kesler and Lee, and a modified SRK equation of state method. Both correlations are found to work well in predicting the enthalpy of thiophene.

The depolymerization of Illinois No. 6 coal by a series of solvents having different basecities (pK/sub a/) and nucleophilicities (Swain-Scott nu values) showed no dependence on either the basicity of nucleophilicity of the solvents. As expected, the conversion decreases as the temperature of the reaction is reduced, but the lower the reaction temperature, the higher the percentage of amine incorporation becomes in the products. 5 tables.

The objective of this project is to produce one or more microorganisms capable of removing the organic and inorganic sulfur in coal. The original specific technical objectives of the project were to: Clone and characterize the genes encoding the enzymes of the ``4S`` pathway (sulfoxide/sulfone/sulfonate/sulfate) for release of organic sulfur from coal; return multiple copies of genes to the original host to enhance the biodesulfurization activity of that organism; transfer this pathway into a fast-growing chemolithotropic bacterium; conduct a batch-mode optimization/analysis of scale-up variables.

The objective of this project is to produce one or more microorganisms capable of removing the organic and inorganic sulfur in coal. The original specific technical objectives of the project were to: Clone and characterize the genes encoding the enzymes of the 4S'' pathway (sulfoxide/sulfone/sulfonate/sulfate) for release of organic sulfur from coal; return multiple copies of genes to the original host to enhance the biodesulfurization activity of that organism; transfer this pathway into a fast-growing chemolithotropic bacterium; conduct a batch-mode optimization/analysis of scale-up variables.

The scope of this effort includes the theoretical development of a multi-input, multi-output (MIMO) Model Reference Control (MRC) algorithm, (i.e., model following control law), Model Reference Adaptive Control (MRAC) algorithm and the formulation of a nonlinear model of a typical electric power plant. Previous single-input, single-output MRAC algorithm designs have been generalized to MIMO MRAC designs using the MIMO MRC algorithm. This MRC algorithm, which has been developed using Command Generator Tracker methodologies, represents the steady state behavior (in the adaptive sense) of the MRAC algorithm. The MRC algorithm is a fundamental component in the MRAC design and stability analysis. An enhanced MRC algorithm, which has been developed for systems with more controls than regulated outputs, alleviates the MRC stability constraint of stable plant transmission zeroes. The nonlinear power plant model is based on the Cromby model with the addition of a governor valve management algorithm, turbine dynamics and turbine interactions with extraction flows. An application of the MRC algorithm to a linearization of this model demonstrates its applicability to power plant systems. In particular, the generated power changes at 7% per minute while throttle pressure and temperature, reheat temperature and drum level are held constant with a reasonable level …