Improved method for cladding the inside of metal tubes

Creep characteristics of molybdenum at high temperature and stress are utilized to compress tungsten foil liner against inner surface of tantalum alloy cylinder to form bond at interface. Temperature and pressure can be accurately controlled and size of workpiece is limited only by furnace size

Statistical analysis of high-temperature creep-rate data for alloys of tantalum, molybdenum, and columbium

Creep rate equations for refractory metal alloys of tantalum molybdenum, and columbiu

Thermal expansion method for lining tantalum alloy tubing with tungsten

A differential-thermal expansion method was developed to line T-111 (tantalum - 8 percent tungsten - 2 percent hafnium) tubing with a tungsten diffusion barrier as part of a fuel element fabrication study for a space power nuclear reactor concept. This method uses a steel mandrel, which has a larger thermal expansion than T-111, to force the tungsten against the inside of the T-111 tube. Variables investigated include lining temperature, initial assembly gas size, and tube length. Linear integrity increased with increasing lining temperature and decreasing gap size. The method should have more general applicability where cylinders must be lined with a thin layer of a second material

Heat-transfer and pressure drop correlations for hydrogen and nitrogen flowing through tungsten wire mesh at temperatures to 5200 deg r

Heat transfer and friction pressure drop for forced convection of hydrogen and nitrogen through electrically heated tungsten wire mes

A 4500 deg R /2500 deg K/ flowing-gas facility

High temperature flowing gas heater consisting of four stages for heating gase

Illuminating trap density trends in amorphous oxide semiconductors with ultrabroadband photoconduction

Under varying growth and device processing conditions, ultrabroadband photoconduction (UBPC) reveals strongly evolving trends in the defect density of states (DoS) for amorphous oxide semiconductor thin-film transistors (TFTs). Spanning the wide bandgap of amorphous InGaZnO$_x$ (a-IGZO), UBPC identifies seven oxygen-deep donor vacancy peaks that are independently confirmed by energetically matching to photoluminescence emission peaks. The sub-gap DoS from 15 different types of a-IGZO TFTs all yield similar DoS, except only back-channel etch TFTs can have a deep acceptor peak seen at 2.2 eV below the conduction band mobility edge. This deep acceptor is likely a zinc vacancy, evidenced by trap density which becomes 5-6x larger when TFT wet-etch methods are employed. Certain DoS peaks are strongly enhanced for TFTs with active channel processing damage caused by plasma exposure. While Ar implantation and He plasma processing damage are similar, Ar plasma yields more disorder showing a 2x larger valence-band Urbach energy and two orders of magnitude increase in the deep oxygen vacancy trap density. Changing the growth conditions of a-IGZO also impacts the DoS, with zinc-rich TFTs showing much poorer electrical performance compared to 1:1:1 molar ratio a-IGZO TFTs owing to the former having a ~10xlarger oxygen vacancy trap density. Finally, hydrogen is found to behave as a donor in amorphous indium tin gallium zinc oxide TFTs.Comment: 11 pages, 6 figure

Non-Newtonian fluid flow through three-dimensional disordered porous media

We investigate the flow of various non-Newtonian fluids through three-dimensional disordered porous media by direct numerical simulation of momentum transport and continuity equations. Remarkably, our results for power-law (PL) fluids indicate that the flow, when quantified in terms of a properly modified permeability-like index and Reynolds number, can be successfully described by a single (universal) curve over a broad range of Reynolds conditions and power-law exponents. We also study the flow behavior of Bingham fluids described in terms of the Herschel-Bulkley model. In this case, our simulations reveal that the interplay of ({\it i}) the disordered geometry of the pore space, ({\it ii}) the fluid rheological properties, and ({\it iii}) the inertial effects on the flow is responsible for a substantial enhancement of the macroscopic hydraulic conductance of the system at intermediate Reynolds conditions. This anomalous condition of ``enhanced transport'' represents a novel feature for flow in porous materials.Comment: 5 pages, 5 figures. This article appears also in Physical Review Letters 103 194502 (2009

Validating a generic cancer consumer quality index in eight European countries, patient reported experiences and the influence of cultural differences

BackgroundTaking patient centeredness into account is important in healthcare. The European Cancer Consumer Quality Index (ECCQI) is a validated tool for international benchmarking of patient experiences and satisfaction.This study aimed to further validate the ECCQI in larger and more uniform groups of high volume tumours such as breast and prostate cancer. A second objective was the verification of the influence of cultural factors of the country to determine its possible use in international benchmarking.MethodsData from two survey studies in eight European countries were combined. Socio-demographic correlations were analysed with Kruskall-Wallis and Mann-Whitney tests. Cronbach's alpha was calculated to validate internal consistency. Influences of masculinity (MAS), power distance (PD) and uncertainty avoidance (UA) were determined by linear regression analysis in a general model and subgroup models.ResultsA total of 1322 surveys were included in the analysis (1093 breast- and 348 prostate cancer patients). Cronbach's alpha was good (alpha >= 0.7) or acceptable (0.5Peer reviewe

Off-Equilibrium Dynamics in Finite-Dimensional Spin Glass Models

The low temperature dynamics of the two- and three-dimensional Ising spin glass model with Gaussian couplings is investigated via extensive Monte Carlo simulations. We find an algebraic decay of the remanent magnetization. For the autocorrelation function $C(t,t_w)=[]_{av}$ a typical aging scenario with a $t/t_w$ scaling is established. Investigating spatial correlations we find an algebraic growth law $\xi(t_w)\sim t_w^{\alpha(T)}$ of the average domain size. The spatial correlation function $G(r,t_w)=[< S_i(t_w)S_{i+r}(t_w)>^2]_{av}$ scales with $r/\xi(t_w)$. The sensitivity of the correlations in the spin glass phase with respect to temperature changes is examined by calculating a time dependent overlap length. In the two dimensional model we examine domain growth with a new method: First we determine the exact ground states of the various samples (of system sizes up to $100\times 100$) and then we calculate the correlations between this state and the states generated during a Monte Carlo simulation.Comment: 38 pages, RevTeX, 14 postscript figure