Radiation-induced electron migration along DNA is a mechanism by which randomly produced stochastic energy deposition events can lead to nonrandom types of damage along DNA manifested distal to the sites of the initial energy deposition. Electron migration along DNA is significantly influenced by the DNA base sequence and DNA conformation. Migration along 7 base pairs in oligonucleotides containing guanine bases was observed for oligonucleotides irradiated in solution which compares to average migration distances of 6 to 10 bases for Escherichia coli DNA irradiated in solution and 5.5 base pairs for Escherichia coli DNA irradiated in cells. Evidence also suggests that electron migration can occur preferentially in the 5{prime} to 3{prime} direction along DNA. Our continued efforts will provide information regarding the contribution of electron transfer along DNA to formation of locally multiply damaged sites created in DNA by exposure to ionizing radiation.

We summarize recent theoretical results of our group concerning the electronic states of the strongly correlated fermions at nonzero temperature. The state of almost localized fermions is discussed within a mean-field approach for auxiliary bosons, both in the narrow-band (Section 2) and in the hybridized band (Section 3) cases. This state represents a metallic state of correlated fermion systems (such as V{sub 2}O{sub 3}) below the Mott-Hubbard localization threshold. The Fermi liquid state does not describe properly the properties of narrow band electrons in the large Hubbard -- U limit beyond the localization threshold. Therefore, in Section 4 and 5 we introduce a phenomenological concept of statistical spin liquid which describes principal features of a crossover from a high-temperature superconductor to the Mott insulator for a two-dimensional system. It also reproduces the main features of the phase diagram for La{sub 2-x}Sr{sub x}CuO{sub 4} system, which is modelled by a planar structure.

While much is known about nocturnal drainage flow down a mountain valley, the factors that determine the structure of the valley flow are not completely understood. For example, there are a number of questions regarding the influence of tributaries on the valley flow. Does the presence of tributaries increase or decrease the mass flux out of the valley; does their presence alter the mass flux along the valley; how is the drainage jet structure modified by the presence of tributaries; or, is their presence insignificant? In this study, we investigate these questions via numerical experiments.

The purpose of this document is to establish the fire protection policy for Westinghouse Hanford Company (WHC) relative to US Department of Energy (DOE) directives for Fire Hazards Analyses (FHAs) and their relationship to facility Safety Analysis Reports (SARs) as promulgated by the DOE Richland Operations Office.

Need-based cross cutting technology is being developed which is broadly applicable to the clean up of hazardous and radioactive waste within the US Department of Energy`s complex. Highly modular, reusable technologies which plug into integrated system architectures to meet specific robotic needs result from this research. In addition, advanced technologies which significantly extend current capabilities such as automated planning and sensor-based control in unstructured environments for remote system operation are also being developed and rapidly integrated into operating systems.

We have measured the temperature dependence of the intensity of the lowest energy two-photon absorption line in poly(di-n-hexylsilane) and find that it does not change between ambient temperature and 14 K. The line width decreases by about a factor of three.

The Sloan Digital Sky Survey will produce a detailed digital photometric map of half the northern sky to about 23 magnitude using a special purpose wide field 2.5 meter telescope. From this map we will select {approximately} 10{sup 6} galaxies and 10{sup 5} quasars, and obtain high resolution spectra using the same telescope. The imaging catalog will contain 10{sup 8} galaxies, a similar number of stars, and 10{sup 6} quasar candidates.

The fast spectrum reactor provides the only avenue to control of the overall amounts of plutonium world-wide that also fits naturally into electricity-generation systems. Sufficient plutonium has now been produced, and is currently being produced, that the characteristic that this system possesses to burn plutonium rather than breed it should be the reference configuration for such reactors for a long time. Fuel recycle is the key and recycle with as little plutonium purification as possible is desirable. Such development is taking place within the integral Fast Reactor program and is at the point of demonstration at engineering scale.

New, high-strength, hollow, glass microspheres filled with pressurized hydrogen exhibit storage densities which make them attractive for bulk hydrogen storage and transport. The hoop stress at failure of our engineered glass microspheres is about 150,000 psi, permitting a three-fold increase in pressure limit and storage capacity above commercial microspheres, which fail at wall stresses of 50,000 psi. For this project, microsphere material and structure will be optimized for storage capacity and charge/discharge kinetics to improve their commercial practicality. Microsphere production scale up will be performed, directed towards large-scale commercial use. Our analysis relating glass microspheres for hydrogen transport with infrastructure and economics` indicate that pressurized microspheres can be economically competitive with other forms of bulk rail and truck transport such as hydride beds, cryocarbons and pressurized tube transports. For microspheres made from advanced materials and processes, analysis will also be performed to identify the appropriate applications of the microspheres considering property variables, and different hydrogen infrastructure, end use, production and market scenarios. This report presents some of the recent modelling results for large beds of glass microspheres in hydrogen storage applications. It includes plans for experiments to identify the properties relevant to large-bed hydrogen transport and storage applications, of the …

Storage of electrical energy on a utility scale is currently not practicable for most utilities, preventing the full utilization of existing base-load capacity. A potential solution to this problem is Flywheel Energy Storage (FES), made possible by technological developments in high-temperature superconducting materials. Commonwealth Research Corporation (CRC), the research arm of Commonwealth Edison Company, and Argonne National Laboratory are implementing a demonstration project to advance the state of the art in high temperature superconductor (HTS) bearing performance and the overall demonstration of efficient Flywheel Energy Storage. Currently, electricity must be used simultaneously with its generation as electrical energy storage is not available for most utilities. Existing storage methods either are dependent on special geography, are too expensive, or are too inefficient. Without energy storage, electric utilities, such as Commonwealth Edison Company, are forced to cycle base load power plants to meet load swings in hourly customer demand. Demand can change by as much as 30% over a 12-hour period and result in significant costs to utilities as power plant output is adjusted to meet these changes. HTS FES systems can reduce demand-based power plant cycling by storing unused nighttime capacity until it is needed to meet daytime demand.

The working group on colonel streamers convened on the first day of the 2nd SOHO Workshop, which took place in Marciana Marina, Isola d`Elba, 27 September--1 October 1993. Recent progress in streamer observational techniques and theoretical modeling was reported. The contribution of streamers to the mass and energy supply for the solar wind was discussed. Moreover, the importance of thin electric current sheets for determining both the gross dynamical properties of streamers and the fine-scale filamentary structure within streamers, was strongly emphasized. Potential advances to our understanding of these areas of colonel physics that could be made by the contingent of instruments aboard SOHO were pointed out.

CALOR89, A Monte Carlo particle physics code package in conjunction with ISAJET, a high energy particle collision code, has been successfully used to evaluate the radiation environment of a high energy physics collider detector. We found that for a collider luminosity of 10{sup 33} cm{sup {minus}2sec{minus}1}, the neutron fluences can be significant at certain detector locations.

Material properties affect the deformation and failure modes in structural parts. When performing finite element analyses to compare response for different materials, different levels of mesh discretization may be necessary for each analyses because the failure mode changes, even through the part geometry and loading remain the same. Take, for example, strain localization, a material dependent phenomenon. When localization occurs, the mesh needs to be much finer to capture the steep strain gradients in the region of localization than in a case where localization does not occur. Although this requirement is almost intuitive once stated, it is often not used in practice because the effects are less pronounced when failure is not present, and also because failure modes are difficult to anticipate. The lack of availability of constitutive models for failure prediction is also a contributing factor. This paper describes a recent study regarding the effect of mesh refinement on failure prediction in a part modeled with two different materials.

Quality systems development in environmental measurements for compliance with regulatory requirements for nuclear and other contaminants in the environment is one of the major challenges in current technology disciplines. Efforts to fulfill the mission and objectives of funded projects will not be successful on a timely and cost-effective schedule without adequate plans and credible action for the protection of workers, facilities, and the public in environment, safety, and health aspects. This can be accomplished through quality assurance planning and implementation of an effective, controlled environmental measurements program.

This is the first of two articles concerned with the simulation of multiphase flows. The discussion begins here with a derivation of the exact, ensemble-average equations. Examples of the most basic closures are given, and the well-posedness of the equations is demonstrated in the context of forward-time numerical solution procedures.

Analytical and experimental methods were used to study a series of test specimens consisting of plasma sprayed layers of NiCrA1Y/ZrO{sub 2} of various compositions.The coatings were seeded with artificial defects and were sprayed on steel disks. Two types of defects were used: flat bottomed holes drilled in the steel substrate and patches of room temperature vulcanizing silicone within the coatings. Defect sizes ranged from 0.1 to 10 mm and were at depths below the coating surface from 0.6 to 3.6 min. The method of time resolved infrared radiometry was used with two different heat sources, an acetylene torch and a high intensity lamp, to inspect the coatings. The torch allowed excellent sensitivity at depths of less than 2 mm and the lamp revealed flaws through the full coating thickness. Two analytical models were developed to study beat flow in the test specimens: a finite element model and an electrical analog model. Results from the two models were compared to check consistency and the finite element model results were compared with experimental results. The finite element code was chosen for further development due to its greater flexibility and ease of use.

The FOEHN critical experiments were analyzed to validate the use of multigroup cross sections in the design of the Advanced Neutron Source. Eleven critical configurations were evaluated using the KENO, DORT, and VENTURE neutronics codes. Eigenvalue and power density profiles were computed and show very good agreement with measured values.

Epitaxial PbTiO{sub 3} films were prepared by metal-organic chemical vapor deposition (MOCVD) on MgO(001), SrTiO{sub 3}(001) and LaAlO{sub 3}(001) surfaces. Four-circle X-ray diffraction and optical waveguiding experiments were performed to characterize the deposited films. The films on all three substrates were single-crystal; however, the domain structure of the films was strongly dependent on the substrate material. Films on MgO and LaAIO{sub 3} substrates showed a large amount of 90{degrees} domain structures, whereas, the degree of twinning was greatly suppressed for films on SrTiO{sub 3}. The refractive indices and optical birefringence of the films were measured as a function of wavelength using the film-prism coupling method. The authors found that for films on LaAIO{sub 3}(001), the ordinary index and for films on MgO(001) both the ordinary and extraordinary refractive indices were higher than those of bulk single-crystal PbTiO{sub 3}. For films grown on SrTiO{sub 3}(001), the ordinary refractive index was very close to that of single crystal PbTiO{sub 3}. They correlate the increased refractive index and the reduced birefringence to the degree of epitaxial strain and twinning in the samples, respectively.

Thin films of amorphous carbon/hydrogen, also known as diamond-like carbon or DLC, are of interest as an economical alternative to diamond in a variety of coatings applications. We have investigated the thermal stability of DLC films deposited onto tungsten and aluminum substrates via plasma CVD of methane. These films contain approximately 40 atom % hydrogen, and based on Auger spectra the carbon in the films is estimated to be 60% sp{sup 3} hybridized and 40% sp{sup 2} hybridized. Thermal desorption, Auger, and Raman measurements all indicate that the DLC films are stable to 250--300C. Between 300 and 500C, thermal evolution of hydrogen from the films is accompanied by the conversion of carbon from sp{sup 3} to sp{sup 2} hybridization, and Raman spectra indicate the conversion of the overall film structure from DLC to micro-crystalline graphite or so called ``glassy`` carbon. These results suggest that DLC of this type is potentially useful for applications in which the temperature does not exceed 250C.

Several leading line- and point-focus photovoltaic concentrator system development programs are reviewed, including those by ENTECH, SEA Corporation, AMONIX, and Alpha Solarco. Concentrating collectors and trackers are gaining maturity and reaching product status as designs are made more manufacturable and reliable. Utilities are starting to take notice of this emerging technology, and several privately-funded utility installations are underway. Several advantages are offered by concentrators, including low system and capital cost and rapid production ramp-up. These are discussed along with issues generally raised concerning concentrator technology.

We have found that a strain-induced oscillation in the decay of the picosecond photoinduced absorption of polyacetylene (CH){sub x} can be used to identify the allowed and forbidden electronic transitions in that polymer.

The authors report on the development of a 260mJ 248 nm KrF laser with 98.7% depth of modulation at 1.3 GHz and 77% depth of modulation at 2.6 GHz using a 1.3 GHz microwave source driving a Pockel`s cell. Subsequent single-pass amplification of the modulated KrF source to the 1/4-joule level is shown to be straight forward with no noticeable degradation of the modulation depth.

Continuum fluorescence across interfaces separating regions of differing composition is difficult to calculate. This paper illustrates a case of continuum fluorescence in analysis of superconducting NbTi/Cu composite wire which could lead to erroneous compositions due to Cu fluorescence by continuum x rays generated in an NbTi alloy. An approximate treatment of the continuum fluorescence is presented. 3 figs, 4 refs.

Perhaps the most outstanding discrepancy between prediction and measurements in current particle physics comes from the solar neutrino problem, in which a large deficit of high-energy solar neutrinos is observed. Many Nonstandard Solar Models have been invoked to try to reduce the predicted flux, but all have run into problems in trying to reproduce other measured parameters (e.g., the luminosity) of the Sun. Other explanations involving new physics such as neutrino decay and neutrino oscillations, etc. have also been proffered. Again, most of these explanations have been ruled out by either laboratory or astrophysical measurements. It appears that perhaps the most likely particle physics solution is that of matter enhanced neutrino oscillation, the Mikheyev-Smirnov-Wolfenstein (MSW) oscillations. Two new radiochemical gallium experiments, which have a low enough threshold to be sensitive to the dominant flux of low-energy p-p neutrinos, now also report a deficit and also favor a particle physics solution.