This paper presents a sliding mode observer for sensorless operation of SRM (switched reluctance motor) drive. Design of such an observer depends mainly on the nonlinear model of SRM. In this technique, neither extra hardware nor huge memory space arenot required but it only requires active phase measurements. Furthermore, PI (proportional integral) are suggested to operate individually along w...

The U.S. National Institute of Standards and Technology (NIST) provides a number of particulate matter (PM) standard reference materials (SRM) for use in environmental and toxicological methodology and research. We present here the first analysis with respect to the molecular structure of the carbon in three such NIST SRM samples, i.e., diesel engine exhaust soot from heavy duty equipment engin...

201 One cannot meaningfully evaluate solar geoengineering without a scenario for its implementation. It is now common, for example, to assert that more scientific research is needed to assess the balance between the risks and benefits of solar geoengineering, hereafter called solar radiation management (SRM). Yet the balance between risks and benefits depends at least as strongly on how SRM is ...

Two new species of Stenochironomus Kieffer, 1919 are described in Brazil. New records of Stenochironomus nudipupa Borkent, 1984 and S. gladius Borkent, 1984 from Brazil, new data on geographical distribution of S. jubatus Borkent, 1984 and S. triannulatus Borkent, 1984 from the State of Roraima, and S. bacrionis Borkent, 1984 recorded from the State of Amazonas, as well as emended descriptions ...

geographic information and analysis provide a wide range of data and techniques to monitor and manage natural resources. as an important case, in arid and semi-arid areas, water management is critical for both local governance and citizens. as a result, the estimation of water potential brought by snowmelt runoff and rainfalls seems to be very useful and important for these areas. hydrological ...

This paper addresses a basic control issue in switched reluctance motor (SRM) drives—the production of a ripple-free torque. Simple and largely model-independent conventional supply waveforms are not able to satisfy this requirement. The goal of this paper is to improve SRM dynamical performance by compensating for motor nonlinearities, while maintaining the robustness of conventional methods. ...

The problem of torque tracking PI-controller design for switched reluctance motor (SRM) drive is discussed, where SRM magnetization characteristics are highly nonlinear, and torque is a complex and coupled function of phase current and rotor position. A distinctive feature of the control system designed is that two-time-scale motions are artificially forced in the closed-loop system by the sele...

Prolonged anoxia has deleterious effects on islets. Gas-permeable cell culture devices can be used to minimize anoxia during islet culture and especially during shipment when elimination of gas-liquid interfaces is required to prevent the formation of damaging gas bubbles. Gas-permeable bags may have several drawbacks, such as propensity for puncture and contamination, difficult islet retrieval...