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991.
Healthcare executives struggle with schemes to encourage their institution's affiliated physicians to "buy" into the information systems master plan. By involving physicians initially as members of an MIS Executive Committee, one tertiary-care medical center in Pennsylvania promoted not only "buy-in," but stimulated physician curiosity, active use and even demands about future directions of IS at the medical center. 相似文献
992.
Examination of some possible biases in double pair comparison estimates of safety belt effectiveness
L Evans 《Accident; analysis and prevention》1988,20(3):215-218
Biases in double pair comparison estimates of safety belt effectiveness due to two effects (noncoding of some surviving passengers, and driver/passenger impact during crashes) are investigated by calculating effectiveness from fatality frequencies assumed altered by the biases. Noncoding surviving right-front passengers does not affect estimates for drivers, but does overestimate slightly passenger effectiveness. Two biasing driver/passenger contact effects occur for right-side impacts--a "cushioning" effect (risk to unbelted driver is reduced by striking passenger rather than the vehicle interior) and a "missile" effect (passenger risk is increased by being struck by unrestrained driver). Cushioning and missile effects both reduce estimates; their combined effects could cause right-side impact effectiveness to be underestimated by as much as 20% (probably much less). Correcting for all effects increases the overall estimate from 42.6% to 43.2%. Thus, to the nearest percent, the result is still that if all presently unbelted drivers and right-front-seat passengers were to become wearers, fatalities to this group would decline by (43 +/- 3)%. 相似文献
993.
Sean G. Fronczak Jordan M. N. Thorpe Myles C. Thomas Maggie J. Cassidy Jennifer L. Evans 《Journal of Adhesion Science and Technology》2018,32(19):2099-2110
Variations in roughness on a surface spawn variations in adhesion force between the surface and any particles that contact the surface. To fully characterize the adhesion that will be exhibited when a particle contacts any location on the surface, it is desirable to map the surface with nanoscale detail. Since it is impractical to make nanoscale roughness measurements over the entirety of a surface with a characteristic dimension on the order of centimeters, a relationship between the number of surface measurements and the likely variation in the expected adhesion force is similarly desirable. In this work, the predicted van der Waals force was used to describe the particle adhesion force. The bootstrap statistical method was employed to estimate the error associated with the predicted mean adhesion force between a smooth spherical particle and a rough surface as a function of the number of locations on the surface where the roughness was measured. Specifically, 40 atomic force microscope (AFM) topographical scans (5 × 5 μm) were taken of three different surfaces and used as model surface inputs to an existing van der Waals adhesion force simulator. The simulator described the expected adhesion force resulting from 1200 contacts between the smooth, spherical particle (10 μm diameter) and random locations on each scanned area. After analyzing the results using the bootstrap method, it was determined that the adhesion between the particle and 10–15 scanned areas (out of 40) optimizes the accuracy of the predicted adhesion with respect to the researcher’s labor. 相似文献
994.
Drew Evans 《Polymer International》2018,67(4):351-355
For almost four decades conducting polymers (CPs) have maintained the interest of the global scientific community. This interest arises from the unique blend of properties that these materials possess: tuneable electrical properties combined with mechanical flexibility of traditional polymers. In more recent times the broader investigation of CP properties and behaviour has led to new potential applications, such as photovoltaic and bioelectronic devices. The promise of CPs is considerable, yet to date they have had limited penetration into the commercial and industrial sectors. This perspective article highlights some of the challenges and opportunities ahead as CPs translate from the research sector into commercial products. In particular is the need to study in depth the manufacturing process(es) of CPs and how they relate to existing or emerging industry. © 2018 The Author. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 相似文献
995.
Dheeraj Bansal David J. Evans Barrie Jones 《International Journal of Machine Tools and Manufacture》2006,46(10):1068-1078
An algorithm, to estimate the machine system parameters from the motion current signature, based upon non-linear time series techniques for use in the real-time predictive maintenance system is presented in this paper. Earlier work has introduced the use of a neural-network approach to learn non-linear mapping functions for condition monitoring systems. However, the performance of the neural-network largely depends upon the quality of the training data, and that of the quality and type of the pre-processing of the input data. A reverse algorithm called BJEST (Bansal–Jones Estimation), for estimating the machine input parameters using the motion current signature, has been designed and proven to be successful in estimating the macro-dynamics of the motion current signature. This motivated the enhancement of the predictive analysis to incorporate non-linear characteristic of the motion current signature. The results show considerable improvement in the estimation of the parameters using the enhanced BJEST algorithm due to estimation consistency, hence, improving the real-time predictive maintenance system. 相似文献
996.
Coupon specimens of 20% Cr-25% Ni-Nb-stabilized steel have been oxidized in an atmosphere of CO
2-2%CO-670 vppb COS at 0.1 MPa pressure for periods up to 500 hr at 1123 K. Standard specimens, annealed at 1203 K prior to testing, showed an enhancement of iron in the surface scale and a much increased propensity to spall compared with control tests in a sulfur-free atmosphere. The main purpose of the work was to examine the effect of sulfur on the ease of formation of a healing layer under duplex attack produced by depleting specimens in chromium by prior vacuum annealing. It is shown that although a chromium-rich layer had formed, extensive breakdown occurred in the sulphidizing atmosphere leading to continued internal oxidation. Sulfur was found to partition at the base of this attack and to be associated with a large concentration of nickel. Spaliation was also enhanced in the depleted specimens, the favored site being the interface between the spinel and outer iron-rich oxide of the duplex structure. Partitioning of both sulfur and carbon was observed at this interface in those regions of the specimen showing healing layer breakdown. 相似文献
997.
G. A. Freeman Carl Rampacek L. G. Evans 《JOM Journal of the Minerals, Metals and Materials Society》1961,13(5):370-372
A segregation process to concentrate ores not amenable to conventional floatation concentration or sulfuric acid leach treatment is described, and results are given for pilot-plant results over a six-month period. 相似文献
998.
999.
A spectral element method coupled with the elastic viscous split stress technique for computing viscoelastic flows is presented. The rate of deformation tensor is introduced as an additional variable in the momentum equation, but not in the constitutive equation. The nonlinear rheological model, Oldroyd-B, is chosen to simulate the flow of a viscoelastic fluid. Numerical solutions are investigated based on a planar 4:1 abrupt contraction channel flow benchmark problem with different Weissenberg numbers. The results show a good agreement with other numerical predictions. 相似文献
1000.
S. R. J. Saunders H. E. Evans M. Li D. D. Gohil S. Osgerby 《Oxidation of Metals》1997,48(3-4):189-200
Deflection tests have been used to estimate the stresses developed in the alumina layer formed during short-term oxidation of a Fe-22Cr-5Al-0.3Y Fecralloy steel at 1000°C. Elastic analysis of the deflecting specimen is inappropriate under these test conditions because of the low creep strength of the alloy. Accordingly, a recent creep analysis has been used in this work using currently determined creep properties of the alloy substrate. The results of the analysis show that for the thin oxides produced (<1 m), the planar stress within the oxide layer is everywhere compressive. Average values are approximately 850 MPa after 0.5 hr oxidation but reduce to <200 MPa after 6.5 hr. These values are very much less than would be expected under conditions of elastic deformation.Reproduced by permission of the Controller of HMSO. 相似文献