Problem statement: A half-bridge LLC resonant converter with a voltage doubler rectifier has a simple structure and its Zero-Voltage-Switching (ZVS) capability is excellent from zero to full load condition. But conduction loss is more due to high circulating energy thus reducing the system efficiency. Moreover a variable frequency control method makes the control circuits more complicated than ...

amir kabir dam was built in varian strait, at 23 km north of karaj in 1961. the dam is multipurpose and its maim aims are the spring floods control, supplying potable water for tehran city, producing electricity and providing irrigation water. different pollutants which discharge to the river finally enter to the dam reservoir. determining the pollution loads of the dam sub-catchments can help ...

In this study, to achieve the constant current drive and brightness control without a separate pulse width modulation (PWM) converter, a single converter is designed and verified by experiment under the condition of a multiple LED light load with different output voltage (Vf) characteristics. In the case of the input of 140 Watt class level, the proposed converter can drive two voltage type 95 ...

When old adults participate in a strength-training program with heavy loads, they experience an increase in muscle strength and an improvement in the steadiness of submaximal isometric contractions. The purpose of this study was to determine the effect of light- and heavy-load strength training on the ability of old adults to perform steady submaximal isometric and anisometric contractions. Thi...

INTRODUCTION Association between Ascaris lumbricoides infection and asthma is a controversial subject that has been studied by several authors based on the hygiene theory. This work contributes to better understanding this issue. METHODOLOGY This was a cross-sectional study involving 1,004 children from a neighborhood of low socioeconomic status in Campina Grande, Paraíba, northeastern Brazil...

Mobility in ad hoc networks causes link failures, which in turn result in packet losses. TCP attributes these losses to congestion. This results in frequent TCP retransmission timeouts and degradation in TCP performance even at light loads. We propose mechanisms that are based on signal strength measurements to alleviate such packet losses due to mobility at light loads. Our key ideas are (a) i...

Server-class computers cannot consume power without bound, since increased energy consumption translates into increased heat dissipation, greater cooling requirements, reduced computational density, and higher operating costs. For a typical data center, storage alone accounts for 27% of the energy consumption, making storage an important target for energy reduction. Unfortunately, conventional ...

BACKGROUND Previous studies in mice showed that respiratory syncytial virus (RSV) infection was associated with RSV RNA persistence. This study was designed to characterize the significance of RSV RNA persistence and its relation to RSV-induced chronic airway disease. METHODS Mice were inoculated with live RSV, UV light-treated RSV, heat-inactivated RSV, or medium. Bronchoalveolar lavage flui...