A Low-Complexity Circuit for On-Sensor Concurrent A/D Conversion and Compression

A low-complexity circuit for on-sensor compression is presented. The proposed circuit achieves complexity savings by combining a single-slope analog-to-digital converter with a Golomb-Rice entropy encoder and by implementing a low-complexity adaptation rule. The adaptation rule monitors the output codewords and minimizes their length by incrementing or decrementing the value of the Golomb-Rice coding parameter k. Its hardware implementation is one order of magnitude lower than existing adaptive algorithms. The compression circuit has been fabricated using a 0.35 muM CMOS technology and occupies an area of 0.0918 . Test measurements confirm the validity of the design.     

High-temperature long-term strength of shells in aggressive media with regard for the mass exchange

We study the long-term strength of long cylindrical shells placed in aggressive media under the conditions of complex stressed states. The influence of these states on the long-term strength of the shells is described with the help of equivalent scalar stresses. The time to fracture of the shell is found according to the Rabotnov kinetic theory by using two parameters, namely, the degree of damage to the material and the concentration of the medium in the material of the shell. As the boundary condition on the fracture front, we use the condition of mass exchange. We study the interaction between the diffusion and fracture fronts. The time to fracture of the shell is found by using the solution of a system of integrodifferential equations. Under the assumption of mean level of concentration of the medium, we deduce explicit relationships between the times to fracture of the shell in aggressive and neutral media. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 43, No. 2, pp. 17–24, March–April, 2007.     

Interlaboratory ring test of time-resolved fluoroimmunoassays for zeranol and alpha-zearalenol and comparison with zeranol test kits.

Many zeranol immunoassay test kits cross-react with toxins formed by naturally occurring Fusarium spp. fungi, leading to false-positive screening results. This paper describes the evaluation and application of recently published, dry reagent time-resolved fluoroimmunoassays (TR-FIA) for zeranol and the toxin alpha-zearalenol. A ring test of bovine urine fortified with zeranol and/or alpha-zearalenol in four European Union National Reference Laboratories demonstrated that the TR-FIA tests were accurate and robust. The alpha-zearalenol TR-FIA satisfactorily quantified alpha-zearalenol in urine fortified at 10-30 ng ml(-1). The specificity-enhanced zeranol TR-FIA accurately quantified zeranol in the range 2-5 ng ml(-1) and gave no false-positive results in blank urine, even in the presence of 30 ng ml(-1) alpha-zearalenol. Zeranol TR-FIA specificity was demonstrated further by analysing incurred zeranol-free urine samples containing natural Fusarium spp. toxins. The TR-FIA yielded no false-positive results in the presence of up to 22 ng ml(-1) toxins. The performance of four commercially available zeranol immunoassay test kits was more variable. Three kits produced many false-positive results. One kit produced only one potential false-positive using a protocol that was longer than that of the TR-FIA. These TR-FIAs will be valuable tools to develop inspection criteria to distinguish illegal zeranol abuse from contamination arising from in vivo metabolism of Fusarium spp. toxins.     

Granular gases in mechanical engineering: on the origin of heterogeneous ultrasonic shot peening

The behavior of an ultrasonic shot peening process is observed and analyzed by using a model of inelastic hard spheres in a gravitational field that are fluidized by a vibrating bottom wall (sonotrode) in a cylindrical chamber. A marked heterogeneous distribution of impacts appears when the collision between the shot and the side wall becomes inelastic with constant dissipation. This effect is one order of magnitude larger than the simple heterogeneity arising from boundary collision on the cylinder. Variable restitution coefficients bring the simulation closer to the general observation and allow the investigation of peening regimes with changing shot density. We compute within this model other physical quantities (impact velocities, impact angle, temperature and density profile) that are influenced by the number N of spheres.     

Hybridization of acoustic waves in piezoelectric plates

The conditions for hybridization of the zero-order and high-order acoustic waves propagating in a piezoelectric crystal plate have been studied. The dependence of the phase velocity of the hybrid waves on the parameter hf (h is the plate thickness and f is the wave frequency) is established for the potassium niobate and lithium niobate plates possessing various crystallographic orientations and conductivities. It is found that hybridization takes place when the conductivity of a thin surface layer exceeds a certain critical value, which can vary within broad limits depending on the plate material and orientation. The degree of dispersive repulsion of the coupled modes grows with increasing electromechanical coupling coefficient.     

Family-Responsive Interventions, Perceived Organizational and Supervisor Support, Work-Family Conflict, and Psychological Strain.

This study examined organizational family-responsive policies, perceptions of the organization as family supportive, and supervisor support as issues that may be salient to the experience of conflict between paid employment (work) and family roles. Data were collected from 355 managerial personnel in New Zealand. Although work-family conflict and psychological strain were strongly linked, the availability of organizational policies had no significant association with levels of conflict or strain, whereas policy usage was related only to work-to-family interference and not to family-to-work interference. On the other hand, perceptions of the organization as family supportive and supervisor support for work-family balance displayed significant relationships with key variables, highlighting the importance of these variables for interventions designed to ameliorate the negative impact of work-family conflict on managerial well-being. Implications for the effective implementation of family-responsive interventions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How Meta-Analysis Increases Statistical Power.

One of the most frequently cited reasons for conducting a meta-analysis is the increase in statistical power that it affords a reviewer. This article demonstrates that fixed-effects meta-analysis increases statistical power by reducing the standard error of the weighted average effect size (T?.) and, in so doing, shrinks the confidence interval around T?.. Small confidence intervals make it more likely for reviewers to detect nonzero population effects, thereby increasing statistical power. Smaller confidence intervals also represent increased precision of the estimated population effect size. Computational examples are provided for 3 effect-size indices: d (standardized mean difference), Pearson's r, and odds ratios. Random-effects meta-analyses also may show increased statistical power and a smaller standard error of the weighted average effect size. However, the authors demonstrate that increasing the number of studies in a random-effects meta-analysis does not always increase statistical power. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Elastic constants of face-centered cubic and L1<Subscript>2</Subscript> Ni-Si alloys: Composition and temperature dependence

The adiabatic elastic stiffness constants C _ij of Ni-Si single-crystal solid-solution alloys of two slightly different compositions, 10.78 and 11.17 at. pct Si, were measured over the temperature range from 20 °C to 900 °C using the rectangular parallelepiped resonance method. The isotropic elastic constants of the polycrystalline ordered intermetallic compound Ni₃Si containing 23 at. pct Si were also measured over this temperature range. Values of the C _ij for Ni₃Si were estimated from the data on the polycrystalline alloy, as well as from published data in the literature on isomorphous ternary ordered intermetallic compounds containing different amounts of Si. Using measured values and previously published data, the stiffness constants of Ni₃Ti were estimated; these are the only available data on this alloy. The estimated single-crystal elastic constants of Ni₃Si, as well as the experimentally measured bulk modulus, are considerably smaller than published values calculated from first-principles methods. The same is true for the C _ij of Ni₃Ti, but the discrepancies are smaller.     

Work-hardening and recovery mechanisms in gamma-based titanium aluminides

The work-hardening mechanisms in two-phase γ-titanium aluminide alloys were characterized in terms of the glide obstacles determining the velocity and slip path of dislocations, utilizing transmission electron microscopy (TEM) observations and thermodynamic-glide parameters. There was clear evidence that short-range obstacles in the form of dislocation debris and dipoles were produced during plastic deformation at room temperature. These dislocation obstacles contributed significantly to work hardening. The observed strong strain hardening arose from long-range elastic dislocation interactions and the production of dipole and debris defects. The thermal stability of these deformation-induced defects was assessed by isothermal and isochronal annealing. The results indicated that the dipole and debris defects were relatively unstable upon annealing at moderately high temperatures, which led to significant recovery of work hardening. This article is based on a presentation made in the symposium entitled “Fundamentals of Structural Intermetallics,” presented at the 2002 TMS Annual Meeting, February 21–27, 2002, in Seattle, Washington, under the auspices of the ASM and TMS Joint Committee on Mechanical Behavior of Materials.