The risk of pedestrian injury and fatality in collisions with motor vehicles, a social ecological study of state routes and city streets in King County, Washington

This study examined the correlates of injury severity using police records of pedestrian–motor-vehicle collisions on state routes and city streets in King County, Washington. Levels of influence on collision outcome considered (1) the characteristics of individual pedestrians and drivers and their actions; (2) the road environment; and (3) the neighborhood environment. Binary logistic regressions served to estimate the risk of a pedestrian being severely injured or dying versus suffering minor or no injury.Significant individual-level influences on injury severity were confirmed for both types of roads: pedestrians being older or younger; the vehicle moving straight on the roadway. New variables associated with increased risk of severe injury or death included: having more than two pedestrians involved in a collision; and on city streets, the driver being inebriated.Road intersection design was significant only in the state route models, with pedestrians crossing at intersections without signals increasing the risk of being injured or dying.Adjusting for pedestrians’ and drivers’ characteristics and actions, neighborhood medium home values and higher residential densities increased the risk of injury or death. No other road or neighborhood environment variable remained significant, suggesting that pedestrians were not safer in areas with high pedestrian activity.     

Control algorithm synthesis for a crystal oscillator and clock by the use of an adaptive state regulator

An optimal state regulator has been designed for a frequency-time stabilization system for the GLONASS/GPS reference synchronizing receiver, in which the controlled object is represented as an extended state-equation system. __________ Translated from Izmeritel’naya Tekhnika, No. 6, pp. 37–39, June, 2007.     

Approach the powder contact force,voidage, tensile stress,wall frictional stress and state diagram of powder bed by simple pressure drop monitoring

The evaluation of the mechanical properties and the state of a powder bed are essential for industrial powder operations. We assume that the bed incipient yield is approximately the bed incipient fluidization, and the particle contact force, the bed voidage, the bed tensile stress and the bed-wall frictional stress can be determined by simple pressure drop monitoring when gradually increasing the superficial gas velocity from zero. A two-dimensional powder bed voidage-tensile stress state diagram at zero shear stress under anisotropic consolidation is initially prepared. For the sample powder bed, we show that the isotropic tensile stress estimated by the powder yield locus extrapolation, 340 Pa−770 Pa, from a shear tester is different from the anisotropic tensile stress evaluated, 120 Pa–180 Pa, by the pressure drop overshoot approximation.     

Least cost SO2 emission minimization for a petroleum refinery by optimum use of source reduction, tail gas treatment and flue gas desulphurization

With the growing awareness on the necessity to preserve the environment, pollution standards are turning more stringent and minimization of waste at the source has become the first choice option rather than the end-of-pipe treatment. The objective of the present research is to identify the optimum combination of source reduction (SR), tail gas treatment (TGT) and flue gas desulphurization (FGD) to minimize the total cost of overall SO₂ emission from a petroleum refinery to various desired limits. It has been found that for the typical refinery considered, the TGT is the lowest cost option than either SR or FGD; however, only a maximum of ~12.5% reduction is achievable through the TGT. After full utilization of TGT, for the next range of SO₂ emission reductions from ~12.5% to ~64%, the SR is more economical than FGD. For a still stringent SO₂ emission limit, i.e. SO₂ emission reduction higher than ~64%, the full utilization of the TGT and the optimum use of SR and FGD are the best options.     

Testing of numerical methods,convective schemes,algorithms for approximation of flows,and grid structures by the example of a supersonic flow in a step-shaped channel with the use of the CFX and fluent packages

An unsteady supersonic flow of a nonviscous gas with a Mach number M = 3 in a step-shaped channel has been calculated. The accuracy of the forecasts made has been analyzed on the basis of the Roe dissipation model and the advective upwind splitting method with the use of convective schemes of the second and third orders of accuracy and algorithms for approximation of flows. Triangular and polyhedral grids have been tested. The mechanism of formation of an artificial physical instability on grid structures with a local-gradient adaptation has been considered. It is shown that the existence of a singular point — a right corner — in the computational region causes a large phase change in the evolution of the flow. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 2, pp. 326–330, March–April, 2009.     

Synthesis and application of chloromethylated polystyrene modified with 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new sorbent for the on-line preconcentration and determination of copper in water, soil, and food samples by FAAS

In this paper, we report a simple and sensitive on-line solid phase extraction system for the preconcentration and determination of Cu(II) by flame atomic absorption spectrometry (FAAS). This method is based upon the on-line retention of copper at pH 5.0 on a minicolumn packed with chloromethylated polystyrene modified by 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new solid-phase extraction (SPE) sorbent. The retained Cu(II) ions were eluted with 1.0 M HNO₃, and transported directly to FAAS for determination. Several chemical and flow variables were studied and optimized for a quantitative preconcentration and determination of copper(II). At the optimized conditions, for preconcentration of 10.0 mL of a sample solution, a linear calibration graph was obtained over the concentration range of 3.00-120.0 μg L⁻¹ for Cu(II). The limit of detection (3σ), limit of quantification (10σ), and enrichment factor are 0.56 μg L⁻¹, 2.0 μg L⁻¹ and 41, respectively. The relative standard deviation (n = 6) at 20 μg L⁻¹ of Cu(II) is 2.0%. This method could be applied for determination of trace amounts of Cu(II) in water, soil, and food samples with satisfactory results.