[en] Simple statistical mechanics models have been assembled into a wide-range equation of state for the hydrogen isotopes. The solid is represented by an Einstein-Grtineisen model delimited by a Lindemann melting curve. The fluid is represented by an ideal gas plus a soft-sphere fluid configurational term. Dissociation and ionization are approximated by modifying the ideal gas chemical-equilibrium formulation. The T = 0 isotherm and dissociation models have been fitted to new diamond-anvil isotherm and laser-generated shock data. The main limitation of the model is in ionization at high compression

[en] We have investigated the effect of deposition conditions of SnO2 films, deposited by chemical vapor deposition using tin tetrachloride and tetramethyltin precursors, on the film properties. The type of precursor and the deposition temperature affect the morphology of the films. The structure of the films is determined by the deposition temperature: films deposited at low temperatures show a mixed SnO and SnO2 phase. The processing temperature and type of substrate determine the impurity content in the films. Electrical properties (e.g. the carrier mobility) and optical properties of the films are affected by the structure and the impurity content in these layers

[en] Temperature-dependent transport and magnetic measurements on Sr₂Y_0.5Ca_0.5Co₂O₇ indicate that ferromagnetism appears along with a crossover between two forms of variable-range-hopping (VRH) conductivity on cooling. Efros-Shklovskii (ES)-type VRH conduction was found below approximately 30 K, transformed from Mott-type VRH at higher temperature. The magnitude of the Coulomb gap and the Mott-ES VRH crossover temperature are ∼57 K and ∼170 K, respectively. These are unusually large compared to those of nonmagnetic disordered materials. The peculiar electronic state for the ferromagnetic Coulomb gap is probably due to Coulomb correlations among d electrons in the disordered system

[en] In phase two of the Dual-Axis Radiographic Hydrodynamic Test facility (DARHT-II), four electron beam pulses of variable pulse length strike an X-ray converter target to produce time-resolved X-ray image. An important requirement for the converter target is to minimize the hydrodynamic expansion of the converter material so that there is enough material to generate the required X-ray dose for all four pulses. Minimizing the hydrodynamic expansion is also important from the standpoint of beam transport. If there is too much expansion of the converter material, the spot-size of the beam will deteriorate due to the charge neutralization of the beam by the target plasma. The beam spot size can also be deteriorated by backstreaming ions. However, this effect can be minimized by placing a barrier foil in front of the target. In this paper, we present a converter target design, based on the simulations using the radiation hydrodynamics code LASNEX and the Monte Carlo radiation transport code MCNP, that can produce the required X-ray dose for all four pulses with tolerable X-ray spot size variation. Our calculations also show that the barrier foil may block the backstreaming ions for all four pulses

[en] This theory examines the effect of the screened Coulomb field generated by impurity ions on various semiconductor phenomena. The exact equation for the screening length, which is derived for semiconductors, is a function of temperature, doping density and intrinsic carrier density. In silicon the screening length varies from a fraction of a nanometer to thousands of nanometers depending on the temperature and the doping density. The overlap of these impurity fields causes both crystal potential shift and repulsion among impurity ions. The repulsion among the impurity ions gives rise to a pressure build-up, which is attributed to such phenomena as solid solubility and diffusion-induced defect generation. The experimental solubilities of lithium in germanium, and boron, phosphorus, and arsenic in silicon are compared with the theoretical values. Also, the optically enhanced solubility during rapid thermal processing is explained

[en] Matrix-assisted pulsed laser evaporation direct-write was investigated by ultra high-speed optical microscopy. A layer of viscous fluid was irradiated with 355 nm, 30 ns laser pulses in a laser forward transfer configuration. The fluid response as a function of fluence was studied, and several distinct regimes of behavior were observed: plume, jetting and sub-threshold. This work emphasizes the fundamental differences between laser forward transfer of solid-state materials and rheological fluids

[en] Thin films of a transparent conducting oxide solid solution Cd_1+xIn_2-2xSn_xO₄ (x=0.15, 0.45, and 0.70) were deposited via rf magnetron sputtering. X-ray diffraction indicated the films consisted of a polycrystalline spinel phase. Atomic force microscopy measurements revealed a surface root mean square roughness between 1.3 and 6.0 nm. Optical absorption was 10% or less in the visible for x=0.15, 0.45, and 0.70. Optical gaps averaged near 3.5, 3.70, and 3.65 eV for films annealed in Ar/CdS of compositions corresponding to x=0.15, 0.45, and 0.70. Conductivity exceeded 2000 S/cm for x=0.15 and 4000 S/cm for x=0.45 and 0.70. Mobilities of 43, 50, and 56 cm²/Vs were measured for films annealed in Ar/CdS of compositions corresponding to x=0.15, 0.45, and 0.70, respectively. Composition data obtained via electron probe microanalysis indicate the films are becoming Cd deficient during the annealing process. This suggests an excess of In⁺³ and/or Sn⁺⁴ on Cd⁺² sites may play a role in carrier production in these films. The Cd volatilization may also inhibit crystallization and decrease mobility

[en] In view of the expected electricity shortages in Ontario, there is an urgent need for not only new supply but also a significant increase in conservation and load shifting efforts. This report presented the results of a study focused on key technology or market areas that presented opportunities for implementation of energy efficient measures. The materials, analytical results, and outcomes of the study could be utilized as a framework for developing future program delivery models. The report provided a comprehensive market analysis for large industrial operations in Ontario. A market profile was presented for the following sectors: mining; pulp and paper; iron and steel; the chemical industry; petroleum refining; motor vehicle, body and parts manufacturing; cement; and food. Opportunities for conservation and demand management were identified. The report also presented an analysis and recommendations for energy conservation demand management and demand response applicable to large industry. Examples of programs in other jurisdictions in Canada as well as the United States were discussed. 34 refs., 7 tabs., 23 figs., 1 appendix.

[en] Membrane proteins from alkalophilic Bacillus firmus RAB were extracted with octylglucoside, reconstituted into liposomes made from alkalophile lipids. The proteoliposomes were loaded with ²²Na⁺. Imposition of a valinomycin-mediated potassium diffusion potential, positive out, resulted in very rapid efflux of radioactive Na⁺ against its electrochemical gradient. That the Na⁺ efflux was mediated by the electrogenic Na⁺/H⁺ antiporter is indicated by the following characteristics that had been established for the porter in previous studies: dependence upon an electrical potential; pH sensitivity, with activity dependent upon an alkaline pH; inhibition by Li⁺; and an apparent concentration dependence upon Na⁺ that correlated well with measurements in cells and membrane vesicles

[en] Purpose: To develop a new technique, intraoperative high dose rate brachytherapy (IOHDR), to deliver localized radiation therapy intraoperatively to head and neck tumors at sites inaccessible to intraoperative electron beam radiotherapy (IOEBRT) in the skull base region. Methods: After maximal surgical resection, afterloading catheters spaced 1 cm apart embedded in custom surface applicators made of foam or silicone were placed on resected tumor beds. IOHDR was delivered in a shielded operating room using preplanned dosimetry with a nominal 10 Ci iridium-192 source in an HDR micro-Selectron afterloader. Twenty-nine patients (20 males, 9 females) ranging in age from 9 to 80 years (median=61) were irradiated intraoperatively for advanced head and neck tumors at sites inaccessible to IOEBRT. Six patients who had previously received external beam radiation (EBRT) ranging from 50 to 75 Gy, were given 15 Gy of IOHDR only. Twenty-three patients who had no prior radiation received 7.5 to 12.5 Gy IOHDR, and 45 to 50 Gy EBRT was planned post-operatively; however, six of these patients did not complete the planned EBRT. Doses to normal tissues were reduced whenever possible by shielding with lead or by displacement with gauze or retractors. Treatment time ranged from 3.8 to 23 min (median=6.5 min). Five patients received concurrent cis-platinum based chemotherapy. Results: Twenty-nine patients treated to 30 sites had local tumor control of 67% and crude survival of 72%, with the follow-up ranging from 3 to 33 months (median=21 months). In the group of 17 previously unirradiated patients who had completed full treatment (IOHDR and EBRT) to 18 sites, the local tumor control was 89%, and all of these patients survived. Tumor control in the six previously unirradiated patients who did not complete EBRT was 50% with a crude survival of 50%. In the group of six previously irradiated patients treated by IOHDR only, the local tumor control was 17% with a crude survival of 17%. No intraoperative complications were noted. The delayed morbidity included cerebrospinal fluid (CSF) leak with bone exposure (1), chronic subdural hematoma (1), septicemia (1), otitis media (1), and severe xerostomia (1). We cannot comment on long-term morbidity due to the relatively short follow-up period of 21 months. Conclusions: It is feasible to deliver IOHDR, with acceptable toxicity, to skull base tumors at sites inaccessible to IOEBRT. The use of IOHDR as a pre-radiotherapy boost produced excellent local control and survival in the selected group of patients who had no previous radiation therapy. The use of exclusive IOHDR in the previously irradiated group resulted in poor outcome, possibly due to the limitations on re-irradiation doses and/or volumes determined by normal tissue tolerance or because these patients have inherently radioresistant tumors. Higher IOHDR doses, additional EBRT, and/or chemotherapy should be considered for this group. The use of IOHDR as a pre-EBRT boost to maximize local control has a promising future in the treatment of carefully selected patients with advanced skull base tumor