Article asserts that the overall performance of polymer composites depends on not only the intrinsic properties of the polymer matrix and inorganic filler but also the quality of interfacial adhesion. The authors report carbon fiber (CF)/epoxy composites with improved interfacial adhesion by covalent bonding between CFs and the epoxy matrix, which leads to the improved ultimate mechanical properties and enhanced thermal aging performance.

A coupled thermomechanical, thermal transport and segregation analysis of aluminum alloys solidifying on uneven surfaces is presented here. Uneven surfaces are modelled as sinusoids with different wavelengths and amplitudes. Effects of various coupling mechanisms between the solid-shell deformation, air-gap formation, heat transfer, fluid flow and segregation, near the mold-metal interface, are observed for different mold topographies during the early stages of solidification of an aluminum alloy. The role of inverse segregation, arising from shrinkage driven flow in the melt, melt superheat and varying mold surface topography on nucleation of air-gaps and evolution of stresses in the solidifying shell is examined. The numerical model consists of a volume-averaged solidification model coupled with a small-deformation model combining elasto-viscoplastic deformation in the solidifying shell with air-gap nucleation and imperfect contact at the metal/mold interface. Heat transfer at the mold-metal interface is either contact pressure or air-gap dependent and is modelled using the actual contact pressure or air-gap size obtained from the contact sub-problem at the metal-mold interface. Variation in heat transfer leads to variations in fluid flow, segregation and stresses developing in the solid and mushy-zone, which in turn affect the morphology of the growing solid-shell. A wavelength range that leads to a …

The preparation of the title compound, [{sup 3}H{sub 3}]CNS-5161, was accomplished in three steps starting with the production of [{sup 3}H{sub 3}]iodomethane (CT{sub 3}I). The intermediate N-[{sup 3}H{sub 3}]methyl-3-(thiomethylphenyl)cyanamide was prepared in 77% yield by the addition of CT{sub 3}I to 3-(thiomethylphenyl)cyanamide, previously treated with sodium hydride. Reaction of this tritiated intermediate with 2-chloro-5-thiomethylaniline hydrochloride formed the guanidine compound [{sup 3}H{sub 3}]CNS-5161. Purification by HPLC gave the desired labeled product in an overall yield of 9% with greater than 96% radiochemical purity and a final specific activity of 66 Ci mmol{sup -1}.

Polymerase chain reaction (PCR) facilitates DNA detection by significantly increasing the concentration of specific DNA segments. A new class of PCR instruments uses a buoyancy-driven re-circulating flow to thermally cycle the DNA sample and benefits from reduced cycle times, low sample volumes, a miniaturized format, and low power consumption. This paper analyzes a specific buoyancy PCR device in a micro-channel ''race-track'' geometry to determine key parameters about PCR cycle times and other figures of merit as functions of device dimensions. The 1-D model balances the buoyancy driving force with frictional losses. A hydrostatic pressure imbalance concept is used between the left and right sides of the fluid loop to calculate the buoyancy driving force. Velocity and temperature distributions within the channels are determined from two-dimensional analysis of the channel section, with developing region effects included empirically through scaled values of the local Nusselt number. Good agreement between four independent verification steps validate the 1-D simulation approach: (1) analytical expressions for the thermal entrance length are compared against, (2) comparison with a full 3-D finite element simulation, (3) comparison with an experimental flow field characterization, and (4) calculation of the minimum PCR runtime required to get a positive PCR signal from …

The Lawrence Livermore Laboratory (LLL) is currently in the construction stage of the Mirror Fusion Test Facility (MFTF). MFTF will be the next large mirror fusion experiment and employs a large set of superconducting Yin-Yang coils. These coils contain 54,430 kg of stabilized NbTi conductor and will generate a peak field of 7.68 T with a stored energy of 409 MJ. This paper presents details of the design of these coils and the status of the fabrication.

Appropriate treatment for internal depositions of some radionuclides can reduce the radiation doses by as much as factors of two to ten. While at first thought that may seem a relatively small therapeutic effect, it is a useful gain for the patient in reducing the dose and may be a significant help in preventing late effects from the radiation. The list of important available treatments include agents that reduce gastrointestinal absorption, blocking and diluting compounds, mobilizing agents, and chelating drugs. Wound irrigation or excision and lung lavage are mechanical techniques that can reduce radionuclide depositions. Successful treatment depends on early application of these drugs and techniques following exposure. This must be done usually on the basis of very limited exposure information, which emphasizes the need for preplanning the medical emergency program if internal radioactive contamination is possible. In most cases, the risks of treatment are well identified. Since the exposure risks are often poorly understood when the decision for treatment must be made, the omission of treatment can be more serious than proceeding with a low or no risk therapeutic regimen.

The U.S. Department of Energy has established a dual-track approach to the disposition of plutonium arising from the dismantling of nuclear weapons. Both immobilization and reactor-based mixed-oxide (MOX) fuel technologies are being evaluated. The reactor-based MOX fuel option requires assessment of the potential impact of concentrations of gallium (on the order of 1 to 10 ppm), not present in conventional MOX fuel, on cladding material performance. An experimental program was designed to evaluate the performance of prototypic Zircaloy cladding materials against (1) liquid gallium, and (2) various concentrations of G~03. Three types of tests were performed: (1) corrosion, (2) liquid metal embrittlement, and (3) corrosion-mechanical. These tests were to determine corrosion mechanisms, thresholds for temperature and concentration of gallium that delineate behavioral regimes, and changes in the mechanical properties of Zircaloy. Results have generally been favorable for the use of weapons-grade (WG) MOX fhel. The Zircaloy cladding does react with gallium to form intermetallic compounds at >3000 C; however, this reaction is limited by the mass of gallium and is therefore not expected to be significant with a low level (parts per million) of gallium in the MOX fuel. Furthermore, no evidence for grain boundary penetration by gallium or liquid …

Radioactive wastes are generated by all activities which utilize radioactive materials as part of their processes. Generally such activities include all steps in the nuclear fuel cycle (for power generation) and non-fuel cycle activities. The increasing production of radioisotopes in a Member State without nuclear power must be accompanied by a corresponding development of a waste management system. An overall waste management scheme consists of the following steps: segregation, minimization, treatment, conditioning, storage, transport, and disposal. To achieve a satisfactory overall management strategy, all steps have to be complementary and compatible. Waste segregation and minimization are of great importance mainly because they lead to cost reduction and reduction of dose commitments to the personnel that handle the waste. Waste characterization plays a significant part in the waste segregation and waste classification processes, it implicates required waste treatment process including the need for the safety assessment of treatment conditioning and storage facilities.

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Current ideas for designing neutrino factories [ 1,2] and muon colliders [3] require unique configurations of fields and materials to prepare the muon beam for acceleration. This so-called front end system must accomplish the goals of phase rotation, bunching and cooling. We have continued the development of a 3-D tracking code, ICOOL [4], for examining possible muon collider front end configurations. A system is described in terms of a series of longitudinal regions with associated material and field properties. The tracking takes place in a coordinate system that follows a reference orbit through the system. The code takes into account decays and interactions of {approx}50-500 MeV/c muons in matter. Material geometry regions include cylinders and wedges. A number of analytic models are provided for describing the field configurations. Simple diagnostics are built into the code, including calculation of emittances and correlations, longitudinal traces, histograms and scatter plots. A number of auxiliary codes can be used for pre-processing, post-processing and optimization.

A review of different bump-bonding processes used for pixel detectors is given. A large scale test on daisy-chained components from two vendors has been carried out at Fermilab to characterize the yield of these processes. The vendors are Advanced Interconnect Technology Ltd. (AIT) of Hong Kong and MCNC in North Carolina, US. The results from this test are presented and technical challenges encountered are discussed.

Automatic differentiation is a technique for computing derivatives accurately and efficiently with minimal human effort. We employed this technique to generate derivative information of FCAP2 (2-D) and FCAP3 (3-D) programs that simulate the parasitic effects of interconnects and devices. This derivative information is used in the statistical modeling of worst-case interconnect delays and on-chip crosstalks. The ADIC (Automatic Differentiation in C) tool generated new versions of FCAP2 and FCAP3 programs that compute both the original results and the derivative information. Given the ANSI C source code for the function, ADIC generates new code that computes derivatives of the model output with respect to the input parameters. We report on the use of automatic differentiation and divided difference approaches for computing derivatives for FCAP3 programs. The results show that ADIC-generated code computes derivatives more accurately, more robustly, and faster than the divided difference approach.

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This paper describes the progress achieved by the Reduced Enrichment for Research and Test Reactors (RERTR) Program in collaboration with its many international partners during the year 2000 and discusses the main activities planned for the year 2001. The past year was characterized by important accomplishments and events for the RERTR program. Four additional shipments containing 503 spent fuel assemblies from foreign research reactors were accepted by the U.S. Altogether, 3,740 spent fuel assemblies from foreign research reactors have been received by the U.S. under the acceptance policy. Postirradiation examinations of three batches of microplates have continued to reveal excellent irradiation behavior of U-MO dispersion fuels in a variety of compositions and irradiating conditions. h-radiation of two new batches of miniplates of greater sizes is in progress in the ATR to investigate me swelling behavior of these fuels under prototypic conditions. These materials hold the promise of achieving the program goal of developing LEU research reactor fuels with uranium densities in the 8-9 g /cm{sup 3} range. Qualification of the U-MO dispersion fuels is proceeding on schedule. Test fuel elements with 6 gU/cm{sup 3} are being fabricated by BWXT and are scheduled to begin undergoing irradiation in the HFR-Petten in …

A systematic study of the energy and time-resolved photoluminescence of GaInP/GaNxAs1-x double heterostructures has been performed for 0=x=1.3%. A large temperature-dependent optical-bowing coefficient (about 20-25 eV) is observed and the bandgap variation with temperature is found to depend on the nitrogen content. Finally, the minority-carrier lifetime is not simply related to the nitrogen content. Instead, the recombination rate is proportional to the majority-carrier concentration for x=0.3% and the carbon concentration for x=0.3%.

The cleanup of liquid streams contaminated with radionuclides is obtained by the selection or a combination of a number of physical and chemical separations, processes or unit operations. Among those are: Chemical treatment; Evaporation; Ion exchange and sorption; Physical separation; Electrodialysis; Osmosis; Electrocoagulation/electroflotation; Biotechnological processes; and Solvent extraction.

The authors report the results of the BTeV silicon pixel detector tests carried out in the MTest beam at Fermilab in 1999--2000. The pixel detector spatial resolution has been studied as a function of track inclination, sensor bias, and readout threshold.

The vision of ''Smart Cities'' is the urban center of the future, made safe, secure environmentally green, and efficient because all structures--whether for power, water, transportation, etc. are designed, constructed, and maintained making use of advanced, integrated materials, sensors, electronics, and networks which are interfaced with computerized systems comprised of databases, tracking, and decision-making algorithms. This paper discusses a current initiative being led by the Brookhaven National Laboratory to create a research, development and deployment agenda that advances this vision. This is anchored in the application of new technology to current urban center issues while looking 20 years into the future and conceptualizing a city framework that may exist.

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The screening function for zero separation for two is reacting nuclei in a strongly coupled OCP plasma is obtained using new very accurate Monte Carlo OCP fluid simulation data by two methods. The first method obtains, H(0), the screening function at x =0, from the difference of free energies before and after the reaction. The second method is a direct fitting of the Widom expansion in powers of x{sup 2 }to the MC data for the pair distribution function, g(x). The two methods agree to 2%

Theories suggest there is a link between protamine concentrations in individual sperm and male fertility. Previously, biochemical analyses have used pooled samples containing millions of sperm to determine protamine concentrations. These methods have not been able to determine what percentage of morphologically normal sperm are biochemically defective and potentially infertile. Nuclear microscopy has been utilized to measure elemental profiles at the single sperm level. By measuring the amount of phosphorus and sulfur, the total DNA and protamine content in individual sperm from fertile bull and mouse semen have been determined. These values agree with results obtained from other biochemical analyses. Nuclear microscopy shows promise for measuring elemental profiles in the chromatin of individual sperm. The technique may be able to resolve theories regarding the importance of protamines to male fertility and identify biochemical defects responsible for certain types of male infertility.

Quasi-axisymmetry, external kinks and ballooning stability are studied with respect to the plasma shaping and variation in the pressure and current profiles for NCSX. We show that while the kink stability may require a delicate boundary shaping, most quasi-axisymmetry may be achieved using a few low order modes that eliminate the large mirror fields arising partly from boundary shaping for the kink stability. In addition, we demonstrate that the kink and ballooning instability may be improved in the NCSX configurations by a more peaked pressure profile or a broader current profile. Finally, we show numerically that it is possible to construct a quasi-axisymmetric configuration that is stable to the external kink at all current levels for which the edge rotational transform is less than 0.5.

The EPA has declared vitrification to be the Best Available Demonstrated Technology (BDAT) for High Level Radioactive Waste (40 CFR 268.42). Vitrification has been chosen as the method of choice for treating a number of radioactive residues and wastes in the DOE complex. Vitrification offers advantages of waste volume reduction, the ability to handle changing waste forms, and a stable, nonleachable final waste form. Microwave heating is a superior method for vitrification of radioactive wastes. Advantages of microwave heating include: (1) direct waste heating, eliminates need for electrodes, refractories and other consumables; (2) ``in-can`` processing allows for treatment of the material in its final container, (3) a mechanically simple system where the microwaves are generated away from the treatment area and transmitted to the treatment applicator by a wave guide, thus minimizing worker exposure to radiation; (4) easier equipment maintenance; and (5) a high degree of public acceptance.

The mask is deemed one of the areas that require significant research and development in EUVL. Silicon wafers will be used for mask substrates for an alpha-class EUVL exposure tool due to their low-defect levels and high quality surface finish. However, silicon has a large coefficient of thermal expansion that leads to unacceptable image distortion due to absorption of EUV light. A low thermal expansion glass or glass-ceramic is likely to be required in order to meet error budgets for the 70nm node and beyond. Since EUVL masks are used in reflection, they are coated with multilayers prior to patterning. Surface imperfections, such as polishing marks, particles, scratches, or digs, are potential nucleation sites for defects in the multilayer coating, which could result in the printed defects. Therefore we are accelerating developments in the defect reduction and surface finishing of low thermal expansion mask substrates in order to understand long-term issues in controlling printable defects, and to establish the infrastructure for supplying masks. In this paper, we explain the technical requirements for EUVL mask substrates and describe our efforts in establishing a SEMI standard for EUVL masks. We will also report on the early progress of our suppliers in producing …