A design model for surface-termination optimization of off-statesemiconductor devices

An optimization design model for surface termination of off-state semiconductor devices under reverse-bias conditions is presented. The multivariable design model is used to optimize the surface profile shapes for nonplanar devices and the doping profiles of material regions along the surface for planar devices. The effectiveness of the design model in reducing the peak surface electric field to below 50% of the bulk value is demonstrated for two examples of each type of device     

Geothermal reservoir simulation

This paper is intended to be a state of the art review of geothermal reservoir simulation. Its recent application to the modelling of real geothermal reservoirs is described and put in the context of an emerging general approach to reservoir modelling. The use of computer simulation for geothermal well test analysis is described. One of the main recent uses of reservoir simulators has been for conducting numerical experiments aimed at improving the understanding of geothermal reservoir physics. Such studies on fractured reservoirs, the thermal structure of reservoirs and the effects of non-condensable gases and dissolved salts are outlined.     

Investigation of the geothermal anomaly of Travale (Tuscany) by telluric, magnetotelluric and geomagnetic deep sounding measurements

As part of the European Community research programme telluric, magnetotelluric and geomagnetic deep sounding measurements were undertaken at 40 sites within the geothermal area of Travale. In the period range of 6–10,000 s the telluric field inside the Travale graben is strongly polarized and directed, independent of the period, about parallel to the graben strike. The lateral variation of the telluric field amplitude is determined mainly by the distribution of the rocks (e.g. the central part of the geothermal anomaly inside the graben is correlated with a horst structure of resistive rocks) and an influence of the geothermal anomaly on the telluric field distribution cannot be observed. The apparent resistivity, as well as the phase curves, are rather similar at all sites within the graben, exhibiting 4–40 ohm · m for periods of 10 s and 50–500 ohm · m for periods of 10,000 s in E-polarization. In the period range of 10–100 s the E- and B-polarization of magnetotelluric measurements can be interpreted by the 2-D effect of the Travale graben, while with increasing period the induced current system becomes more and more 3-D below all sites. This limits the determination of the sedimentary cover thickness (max. 2500 m) by 1-D and 2-D model calculations to periods of less than 100 s.     

Thirty years later: Attitudes toward the employment of older workers.

Replicated W. K. Kirchner and M. D. Dunnette's (see record 1955-03161-001) study on attitudes toward older workers with 71 male and 5 female hourly employees (aged 18–61 yrs) and 22 male supervisors (aged 27–63 yrs) of a nonunion manufacturing plant. Ss completed a questionnaire that was nearly identical to the one administered in the Kirchner and Dunnette study. Results are similar to those obtained in the earlier study: Hourly workers held more positive attitudes toward older employees than did supervisors, and attitude score correlated strongly with the age of hourly workers but not with the age of supervisors. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

WHIM, the Window Handler and Input Manager

This article describes WHIM, the Window Handler and Input Manager, a window management system being developed as part of the QuickSilver operating system project at IBM's Almaden Research Center. Another version of WHIM runs under AIX on the IBM PC RT. This article contrasts and compares the overlapped window scheme used in WHIM with the tiled window scheme used in other systems. The advantages of the window management scheme used in WHIM are detailed, and the effect of display interfaces on the window manager is described.     

Evaluation of NDT methods for detection of prestressing steel damage at post-tensioned concrete structures

For an assessment of the risk potential of existing structures, where in the case of prestressing steel damage the load-bearing capacity could be significantly affected, non-destructive testing techniques which enable reliable evaluation of the condition of the prestressing steels are of utmost importance. During the demolition of a post-tensioned concrete bridge in Berlin where damage of prestressing wires due to hydrogen-induced stress corrosion cracking were found in former investigations, parts of the girders of the bridge superstructure could be taken out. After non-destructive investigations by means of two testing techniques based on magnetic leakage flux measurement and one technique based on electromagnetic resonance measurement, subsequent removal of the concrete cover up to the ducts, opening the ducts and evaluation of the prestressing steels allowed a verification of the results obtained by the NDT methods. From the results it can be concluded that areas with fractures of several wires can be detected by the two techniques based on magnetic leakage flux measurement.     

A Graphene Field-Effect Device

In this letter, a top-gated field-effect device (FED) manufactured from monolayer graphene is investigated. Except for graphene deposition, a conventional top-down CMOS-compatible process flow is applied. Carrier mobilities in graphene pseudo-MOS structures are compared to those obtained from the top-gated Graphene-FEDs. The extracted values exceed the universal mobility of silicon and silicon-on-insulator MOSFETs