This article discusses the effect of solvent polarity on the fluorescence emission fine structures of coronene derivatives.

This article discusses the solubility of budesonide, hydrocortisone, and prednisolone in ethanol and water mixtures at 298.2 K.

Article discussing polycyclic aromatic hydrocarbon solute probes and the effect of solvent polarity on the fluorescence emission fine structures of coronene derivatives.

A batch vitrification process, which utilizes an oxalate precipitate and frit (or cullet), is being developed at the Savannah River Technology Center (SRTC) to immobilize an Am-Cm solution. Prior to being accepted as the baseline flowsheet, numerous laboratory-scale tests were conducted to demonstrate its feasibility and to characterize the general melt behavior of the oxalate/frit system. The effects of frit particle size and oxalate precipitation temperature were the initial focus of these studies. Two technical issues were identified during these initial tests that warranted further study: a volume or bed expansion was observed at approximately 1140 degrees C and ''excessive'' bubble formation between 1220 - 1250 degrees C. Although high temperature bubble formation does not pose a serious process concern (i.e., longer residence times and/or higher process temperatures minimize bubble retention), the volume expansion is undesirable during processing. The volume expansion may limit the amount of glass that can be produced in a single batch. That is, the batch height may have to be controlled so that the material is contained within the Pt-Rh vessel at all times. Both the volume expansion and high temperature bubble formation have been linked to the thermal reduction of CeO{sub 2}. As part of …

Polymer electrolyte fuel cells (PEFCs) are being actively developed worldwide for transportation applications. The fuel gas generated from reforming hydrocarbon fuels contains small amounts of CO (0.5-1 vol%), even after the water-gas shift reaction. Carbon monoxide is preferentially adsorbed on the platinum electrocatalyst in the PEFC, thus blocking the access of H{sub 2} to the surface of the catalyst and resulting in the degradation of the cell performance. Therefore, the CO concentration in the PBFC reformate must be reduced to a tolerable level of {le} 100 ppm (1). Catalytic preferential oxidation (2), anode air bleed (3), or a combination of the two can be used to reduce CO to trace levels, but their use in a dynamically varying system is problematic. We are developing a sorption process based on the reversible complex-forming and dissociation reactions of CO with Cu(I). These reactions are well documented in patent and literature (4,5).

An initial investigation for the use of an amorphous silicon flat panel as an imaging detector for thermal neutrons is described. A dpiX Model SS2200 imaging panel was used with a Li-6 enriched, LiF-ZnS(Ag) scintillator screen for a thermal neutron imaging investigation using the Breazeale Nuclear Reactor and the neutron radiography facility at Penn State University''s Radiation Science and Engineering Center. Good quality thermal neutron images were obtained at exposures in the range of 106 to 107n/cm2, values that compare favorably with those normally required for a medium-speed film result. Spatial resolution observed was in the order of 2 line pairs/mm, a value consistent with the resolution limitation of the imaging screen. The neutron images showed excellent quality, as determined with radiographs of the modified Type A gage test piece, often used to evaluate thermal neutron radioscopic images. Fourteen consecutive holes in the ''A'' gage test piece were observed, an excellent result as compared to typical neutron radioscopic systems.

The refining industry is a major source of CO{sub 2} emissions in the industrial sector and therefore in the future can expect to face increasing pressures to reduce emission levels. The energy used in refining is impacted by market dictates, crude quality, and environmental regulations. While the industry is technologically advanced and relatively efficient opportunities nevertheless exist to reduce energy usage and CO{sub 2} emissions. The opportunities will vary from refinery to refinery and will necessarily have to be economically viable and compatible with each refiner's strategic plans. Recognizing the many factors involved, a target of 15-20% reduction in CO{sub 2} emissions from the refining sector does not appear to be unreasonable, assuming a favorable investment climate.

Previous work showed the possible existence of a total-dose latch effect in fully-depleted SOI transistors that could severely limit the radiation hardness of SOI devices. Other work showed that worst-case bias configuration during irradiation was the transmission gate bias configuration. In this work we further explore the effects of total-dose ionizing irradiation on fully-depleted SOI transistors. Closed-geometry and standard transistors fabricated in two fully-depleted processes were irradiated with 10-keV x rays. Our results show no evidence for a total-dose latch effect as proposed by others. Instead, in absence of parasitic trench sidewall leakage, our data suggests that the increase in radiation-induced leakage current is caused by positive charge trapping in the buried oxide inverting the back-channel interface. At moderate levels of trapped charge, the back-channel interface is slightly inverted causing a small leakage current to flow. This leakage current is amplified to considerably higher levels by impact ionization. Because the back-channel interface is in weak inversion, the top-gate bias can modulate the back-channel interface and turn the leakage current off at large, negative voltage levels. At high levels of trapped charge, the back-channel interface is fully inverted and the gate bias has little effect on leakage current. However, it is …

The ASTM standards provide guidance and instruction on how to field and interpret reactor dosimetry. They provide a roadmap towards understanding the current ''state-of-the-art'' in reactor dosimetry, as reflected by the technical community. The consensus basis to the ASTM standards assures the user of an unbiased presentation of technical procedures and interpretations of the measurements. Some insight into the types of standards and the way in which they are organized can assist one in using them in an expeditious manner. Two example are presented to help orient new users to the breadth and interrelationship between the ASTM nuclear metrology standards. One example involves the testing of a new ''widget'' to verify the radiation hardness. The second example involves quantifying the radiation damage at a pressure vessel critical weld location through surveillance dosimetry and calculation.

Scientific publications and media reports continually remind us about the environmental hazards that surround us. We are appraised of the environmental legacies left by chemical industries, the defense complex, and even our local dry cleaning establishments. Governmental regulations have dictated that industry provide detailed listings of their input materials, wastes, and emissions to the public and perform risk assessments to demonstrate compliance with standards. These regulations were designed to make industry more accountable and to give the public information that would allow them to understand risks and either work for change or accept their living conditions. This process would appear to be rational, fair, and acceptable to both industry and the public. However, our inability to reach agreement on questions such as ``How Clean is Clean?`` or ``Is It Safe?`` after more than ten years of scientific and public discussions, coupled with the frequency of environmental demonstrations throughout the world, serves as evidence that ``acceptable risk`` has not yet been defined.

The role of the national laboratories, particularly the defense program laboratories, since the end of the cold war, has been a topic of continuing debate. The relationship of national laboratories to industry spurred debate which ranged from designating the labs as instrumental to maintaining U.S. economic competitiveness to concern over the perception of corporate welfare to questions regarding the industrial globalization and the possibility of U.S. taxpayer dollars supporting foreign entities. Less debated, but equally important, has been the national laboratories' potential competition with academia for federal research dollars and discussions detailing the role of each in the national research enterprise.

Research and test reactors around the world are currently returning spent fuel originally enriched in the United States back to the U. S. In May 2006, operators of the reactors will cease to be eligible to return their spent fuel and will have to find national or regional solutions for continued storage, if they want to continue operations of their research reactors. The Savannah River Site (SRS) has looked at a number of options like dry storage, melt-dilute, or continued wet storage for fuel currently stored at SRS. This paper reviews the highlights of the wet basin studies conducted at SRS since 1992. Based on an understanding of the important factors affecting the corrosion of aluminum-clad spent fuel, criteria are presented for the corrosion protection of this fuel in extended water storage. With optimum water quality, aluminum-clad spent fuel can be stored safely and with minimum corrosion for times exceeding 25 years.

Small wind turbines offer a promising alternative for many remote electrical uses where there is a good wind resource. The National Wind Technology Center (NWTC) of the National Renewable Energy Laboratory helps further the role that small turbines can play in supplying remote power needs. The NWTC tests and develops new applications for small turbines. The NWTC also develops components used in conjunction with wind turbines for various applications. This paper describes wind energy research at the NWTC for applications including battery charging stations, water desalination/purification, and health clinics. Development of data acquisition systems and tests on small turbines are also described.

Prototype fuel-cell-powered vehicles have recently been demonstrated in Japan, Europe, and North America. Conceptual designs and simulations of fuel-cell-powered vehicles have also been published [1-3]. Many of these simulations include detailed vehicle performance models, but they use relatively simplistic fuel-cell power system models. We have developed a comprehensive model of a polymer electrolyte fuel cell (PEFC) power system for automotive propulsion. This system simulation has been used to design and analyze fuel-cell systems and vehicles with gasoline (or other hydrocarbons) as the on-board fuel. The major objective of this analysis is to examine the influence of design parameters on system efficiency and performance, and component sizes.

The latest nuclear data are used to examine the sensitivity of the least squares adjustment of the {sup 235}U fission spectrum to the measured reaction rates, dosimetry cross sections, and prior spectrum covariance matrix. All of these parameters were found to be very important in the spectrum adjustment. The most significant deficiency in the nuclear data is the absence of a good prior covariance matrix. Covariance matrices generated from analytic models of the fission spectra have been used in the past. This analysis reveals some unusual features in the covariance matrix produced with this approach. Specific needs are identified for improved nuclear data to better determine the {sup 235}U spectrum. An improved {sup 235}U covariance matrix and adjusted spectrum are recommended for use in radiation transport sensitivity analyses.

Storage of aluminum-clad spent nuclear fuel at the Savannah River Site (SRS) and other locations in the U. S. and around the world has been a concern over the past decade because of the long time interim storage requirements in water. Pitting corrosion of production aluminum-clad fuel in the early 1990''s at SRS was attributed to less than optimum quality water and corrective action taken has resulted in no new pitting since 1994. The knowledge gained from the corrosion surveillance testing and other investigations at SRS over the past 8 years has provided an insight into factors affecting the corrosion of aluminum in relatively high purity water. This paper reviews some of the early corrosion issues related to aluminum-clad spent fuel at SRS, including fundamentals for corrosion of aluminum alloys. It updates and summarizes the corrosion surveillance activities supporting the future storage of over 15,000 research reactor fuel assemblies from countries over the world during the next 15-20 years. Criteria are presented for providing corrosion protection for aluminum-clad spent fuel in interim storage during the next few decades while plans are developed for a more permanent disposition.

The ability to forecast the transport and diffusion of airborne contaminants over long distances is vital when responding to nuclear emergencies. Atmospheric models used in such emergency response applications must be able to include the effects of the evolving synoptic weather systems in a timely manner. The European Tracer EXperiment (ETEX), conducted in October and November 1994, is designed to evaluate the performance of such models. In addition to the tracer experiments, concurrent real-time modeling exercises were conducted by some 24 organizations world-wide, including the Savannah River Technology Center (SRTC) of the U.S. Department of Energy`s Savannah River Site. This paper describes the forecast results obtained by atmospheric modelers at SRTC in applying an advanced three-dimensional modeling system to forecast tracer transport and diffusion during ETEX. Forecast results from the first of two tracer experiments are presented in this preprint paper. Data for the tracer gas concentrations is not yet available; however, surface and sounding data are available from the time periods of the releases. This paper will focus on the evaluation of the forecasts in light of the surface wind data, and relate the forecast evaluations to the differences in the tracer gas dispersion predicted using these forecasts. Plume …

The temperature of highly charged titanium ions produced and trapped in an electron beam ion trap was determined by precisely measuring the broadening of the emission line profile caused by the thermal Doppler motion. The measured temperature ranges from about 700 eV for deeply trapped ions to about 70 eV for ions in a shallow trap. The latter value represents the lowest temperature at which the x-ray emission of collisonally excited heliumlike Ti{sup 20}+ ions has ever been recorded, and the measured transitions represent the narrowest x-ray lines observed from highly charged titanium ions.

The major components of CALOR are HETC, MORSE, EGS4, EGS4PREP, and SPECT, working sequentially on calorimeter detector for high energy physics, experimental analysis, or shielding studies. An effort to combine the components into a single code is described. The new code is modular in nature. For example, one may run only HETC and MORSE. In addition, HETC itself has become modular and may be run in three energy options--up to 2.5 GeV, 15 GeV, and 20 TeV. The size of the low-energy option of HETC is less than 40% of the original HETC. A great advantage of the new code is the elimination of three huge files for passing information from one component to another.

This paper describes a methodology for estimating energy externalities. These externalities are environmental, health, and other damages and benefits that traditionally have not been considered as part of the cost of producing and consuming goods and services. An example of externalities is the effect on human health from exposure to ozone formed by NO{sub x} and other emissions from electric power plants. These damages are valued adversely by individuals (and by society) but are not reflected in the price of electricity. The damage function approach is a methodology which is used for developing quantitative estimates of externalities. This paper describes the five major steps in the damage function approach, focuses on the use of ozone models in that framework, and points out the effects of meteorological variables on estimates of ozone concentrations.

Blazar flare data show energy-dependent lags and correlated variability between optical/X-ray and GeV-Tev energies, and follow characteristic trajectories when plotted in the spectral-index/flux plane. This behavior is qualitatively explained if nonthermal electrons are injected over a finite time interval in the comoving plasma frame and cool by radiative processes. Numerical results are presented which show the importance of the effects of synchrotron self-Compton cooling and plasmoid deceleration. The use of INTEGRAL to advance the understanding of these systems is discussed.

Previous experience with emergency medical rescues in the presence of radiation or contamination indicates that the training provided to emergency responders is not always appropriate. A new course developed at Los Alamos includes specific procedures for emergency response in a variety of radiological conditions.

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Efficient production and collection of a large number of muons is needed to make a neutrino factory based on a muon storage ring viable. Results of extensive MARS simulations are reported for 2 to 30 GeV protons on various targets in a 20 T hybrid solenoid, followed by a matching section and decay channel. Part 1 describes pion and muon yields, targetry issues, and beam energy and power considerations. Part 2 describes radiation loads on targets, the capturing system and shielding.