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91.
A model involving head motion is given for self-consistently computing magnetic recording medium magnetization patterns. The reduction in demagnetizing field due to the presence of the high-permeability head structure is included, as is record head removal, read head replacement, and computation of the readback voltage. The model is capable of handling an arbitrary record current waveform. Optimum record-current amplitude for nonreturn to zero (NRZ) digital recording is first determined, and then single-, double-, and quadruple-transition computations are performed using two different values of hysteresis loop squarenessM_{r}/M_{s} and both linear and exponential current reversals. Results are primarily for the Karlquist fringe field, but the recording properties of a head exhibiting regions in which the fringe field reverses sign are also briefly investigated. 相似文献
92.
The laminar dispersion of a solute in a capillary tube is used to measure diffusion coefficient of oxygen in liquids. A Polarographic type oxygen microelectrode is used to detect the pulse. Such a procedure overcomes the problems of measuring dissolved gases and makes it possible to apply this well known technique to oxygen-liquid systems. The results are in agreement with literature values 相似文献
93.
Ethanol suppressed, in a dose-related manner, glucose-induced insulin (IRI) release and thus delayed the disappearance of glucose from the blood of rats. Pretreatment with pyrazole, an alcohol dehydrogenase inhibitor, exacerbated the effect of ethanol on IRI release, glucose tolerance and glucagon (IRG) release. These results suggest that ethanol produces glucose intolerance by inhibiting glucose-induced IRI release and by augmenting IRG release. Moreover, these findings indicate that ethanol does not have to be metabolized completely in order to produce these effects. 相似文献
94.
Contemporary Reviews of Mine Water Studies in Europe 总被引:2,自引:0,他引:2
95.
Terrorist and criminal acts are now considered credible risks in the process industries. Deliberate attacks on the nation's petroleum refineries and chemical plants would pose a significant threat to public welfare, national security, and the US economy. To-date, the primary response of government and industry has been on improved security to prevent attacks and the associated consequences. While prevention is clearly preferred, the potential for successful attacks must be addressed. If plant security is breached, the extent of the inflicted damage is determined by the available plant safety systems and procedures. We refer to this "inside the gate" response as process threat management. The authors have initiated a joint industry/academia study to address: the level of safety provided by existing plant equipment and safety systems in response to a terrorist act, and identification of process (rather than security) needs or opportunities to address this new safety concern. This paper describes the initial perspectives and issues identified by the team at the beginning of the study. 相似文献
96.
97.
The application of output value analysis, a type of benefit/cost analysis, to a psychiatric patient population is reported. A method for discounting the value of the program if a patient was readmitted within a year after discharge was introduced. The application of this discount factor reduces the value produced by the program and thereby reduces both productivity and effectiveness indices. When applied to groups known to differ in readmission rates, such as first admissions and readmissions or voluntary and involuntary admissions, the discount factor can accentuate group differences markedly. When selected diagnostic groups were compared, the discount factor could even reverse the relative standing of the groups. 相似文献
98.
An alloy of Ti-14.4 at% Al was irradiated with 3.0 MeV 58Ni ions at temperatures near 600°C and to damage levels from 1.3 to 14.7 dpa. TEM examination of these specimens showed the damage produced voids, dislocation loops and network dislocations. The undersize aluminum solute atom segregated to the voids, grain boundaries and the irradiated surface, causing enhanced precipitation of γ'-Ti3Al at these sinks for point defects. Shells of thick coated the voids and a continuous film of γ' was observed on the irradiated surface and on some grain boundaries. The surface film of α2 contained antiphase boundaries. Voids have not been previously observed in irradiated hcp Ti and this is the first observation of substantial irradiation-induced segregation in an hcp alloy. 相似文献
99.
Automatic particle detection through efficient Hough transforms 总被引:4,自引:0,他引:4
Manual selection of single particles in images acquired using cryo-electron microscopy (cryoEM) will become a significant bottleneck when a very large number of images are required to achieve three-dimensional reconstructions at near atomic resolution. Investigation of fast, accurate approaches for automatic particle detection has become one of the current challenges in the cryoEM community. At the same time, the investigation is hampered by the fact that few benchmark particles or image datasets exist in the community. The unavailability of such data makes it difficult to evaluate newly developed algorithms and to leverage expertise from other disciplines. The paper presents our recent contribution to this effort. It also describes our newly developed computational framework for particle detection, through the application of edge detection and a sequence of ordered Hough transforms. Experimental results using keyhole limpet hemocyanin (KLH) as a model particle are very promising. In addition, it introduces a newly established web site, designed to support the investigation of automatic particle detection by providing an annotated image dataset of KLH available to the general scientific community. 相似文献
100.