Security Implementation in Wireless Sensor Network by RF Signal Obfuscation

Wireless Personal Communications - In Wireless Sensor Network (WSN) the wireless communication is an open access communication. Eavesdropping is a common but severe security threat and it is the...     

Vertical distribution of polychlorinated biphenyl congeners in sediment core from Thane Creek area of Mumbai, India

In recent years there has been a growing concern all over the globe about the marine pollution due to persistent organic pollutants. Sediments, which is an important component of marine environment can serve as sorbent or concentrator for various persistent organic pollutants including Polychlorinated Biphenyls (PCBs). Transport and fate of PCB congeners in sediment depends on their physicochemical characteristics. In this study, the depth profile of accumulated PCBs in Thane Creek sediments of Mumbai, India, was studied. The sediment core samples were collected using a gravity corer, processed and analysed for different PCB congeners. Analysis of PCBs in the sediment samples were carried out using gas chromatography system equipped with electron capture detector. The study on vertical distribution of PCBs in sediment could reflect the geochemical history including changes due to anthropogenic releases into the system. The surface segment shows the downward trend for these compounds, indicating slow phase out of PCBs after ban. The concentration and composition of different homologues varies at different depth. An attempt has also been made to find out the various sources of PCBs which could have contributed to these compounds by performing factor analysis over the observed concentrations of the PCB compounds in the core sediment.     

iSuppli：中小型显示器市场随手机市场前进

iSuppli公司预计，新兴地区用户增长将推动2007年手机市场发货量首次打破10亿部的纪录。因此，今年所有中小型显示器（即对角线尺寸小于10英寸的显示器，用于手机、MP3播放器、便携式导航设备（PND）及许多其它产品等设备）发货量将由2006年的35亿台增至38亿台，增长率为6％。到2011年，营收将降至199亿美元，与2007年的220亿美元相比，年均复合增长率（CAGR）为负3％。     

Heterogeneous reactions of alkylamines with ammonium sulfate and ammonium bisulfate

The heterogeneous reactions between alkylamines and ammonium salts (ammonium sulfate and ammonium bisulfate) have been studied using a low-pressure fast flow reactor coupled to an ion drift-chemical ionization mass spectrometer (ID-CIMS) at 293 ± 2 K. The uptake of three alkylamines, i.e., monomethylamine, dimethylamine, and trimethylamine, on ammonium sulfate shows a displacement reaction of ammonium by aminium, evidenced by the release of ammonia monitored using protonated acetone dimer as the reagent ion. For the three alkylamines, the initial uptake coefficients (γ(0)) range from 2.6 × 10(-2) to 3.4 × 10(-2) and the steady-state uptake coefficients (γ(ss)) range from 6.0 × 10(-3) to 2.3 × 10(-4) and decrease as the number of methyl groups on the alkylamine increases. A different reaction mechanism is observed for the uptake of the three alkylamines on ammonium bisulfate, which is featured by an acid-base reaction (neutralization) with irreversible alkylamine loss and no ammonia generation and occurs at a rate limited by diffusion of gaseous alkylamines to the ammonium bisulfate surface. Our results reveal that the reactions between alkylamines and ammonium salts contribute to particle growth and alter the composition of ammonium sulfate and bisulfate aerosols in the atmosphere.     

手机和其他小型显示屏市场

中小型显示屏市场前景看好小型显示屏在消费电子领域扮演着重要角色,其市场总值在200亿美元左右。它不仅仅为客户提供了新的体验,同时也是用户选择产品时考虑的一个因素。而高质量的液晶显示屏价格持续下降也促进了市场的发展。预计未来几年这一市场的销售收入复合增长率将达2％,2007年的市场增长将非常迅猛。尽管这一市场在销售量上不断提高,但价格的下降将产生抵消作用。如果各供应厂家     

I see therefore i read: improving the reading capabilities of individuals with visual disabilities through immersive virtual reality

Universal Access in the Information Society - We aim to help improve the quality of life of people with visual disabilities through the application of emerging technologies. Our current research...