The conductivity of an Al0.24Ga0.76As/GaAs quantum well was studied as a function of the surface charge generated by electron bombardment of the sample in the absence of an externally applied surface electric field. Under a suitable rate of electron irradiation, it was possible to completely shut off the conductive channel, implying a surface density n = 2.5 × 10 el/cm. Light illumination quenc...

We consider a Jackson-type network comprised of 2 queues having state-dependent service rates, in which the queue lengths evolve periodically, exhibiting noisy cycles. To reduce this noise a certain heuristic, utilizing regions in the phase space in which the system behaves almost deterministically, is applied. Using this heuristic, we show that in order to decrease the probability of a custome...

When asked to look through a tube, young children (normal, strabismic, monocularly enucleated) place it between the eyes, while older children turn the head or shut one eye. We videotaped 174 children (normals and strabismics, 2-17 yr of age) and 16 normal adults to find out when and why head turn occurs. In learning to look with one eye, children progressed through a sequence of four responses...

Modern aircrafts have seen a significant growth of avionics systems. Most of new aircrafts have systems for navigation, automatic flight control, collision avoidance systems, flight data recorder, weather radar system as well as communication and monitoring systems. All of these systems use embedded computer systems with increasing memory requirements. In order to reduce the electricity consume...

At the present time, the maintenance of the equipment becomes an essential task for any production system. This task is becoming more important from both the quantity and the quality points of view, particularly in developing countries. Initiating a maintenance system controlled by the computer will be valuable and effective. The developed expert system is a combination of an intelligent infere...

The cost of damage to the non-structural systems in critical facilities like nuclear power plants and hospitals can exceed 80% of the total cost of damage during an earthquake. The failure of nonstructural components, especially, piping systems led to leakage of water and subsequent shut-down of hospitals immediately after the event. Consequently, the evaluation of performance of these types of...

Field tests indicate that temporary well shut-ins may enhance oil recovery from a shale reservoir; however, there is currently no systematic research to specifically guide such detailed operations in the field, especially for design of shut-in scheme and multiple rounds shut-ins. In this study, applicability reservoirs studied, numerical model built using finite element method. order simulate p...

ECONOMIC VALUE OF QUALITY IN WATER THE original abundance of water in the state of New York its very commonness, has dulled her people's appreciation of the subtle qualit;y value of their heritage. M\Iomentarily shut off from their supply the cities and industr-ies would instantly realize its vital necessity. Precipitate ruin of the wonderfully rich, living waters of the state would awaken imme...

We investigate whether the recent slow-down of Whillans Ice Stream (WIS),West Antarctica, may lead to its complete stoppage in the near future, using a numerical model. Basal resistance to ice-stream motion is represented by a continuous till layer whose strength changes in response to basal melting and freezing.We implement a basal drainage system, which acts to hinder ice-stream stoppage thro...