in this research work nano porous silicon layers with different porosity were prepared by using electrochemical etching. surface morphology and size of pores were investigated by scanning electron microscopy (sem).tio2 thin films with ebpvd method have been deposited on the surface of psi layers. the influence of anodization conditions such as anodization time interval and current density on el...

Although traditional headrests are common in most passenger automobiles, they have resulted in only a 20 -30% reduction in whiplash injuries (Nygren 1 985). In response to the limited effectiveness of traditional headrests, automobile manufactures have recently developed more advanced headrests and whiplash prevention mechanisms (Sigi 1 998, and Viano 1 993). The objective of this study was to ...

INTRODUCTION Selecting the proper ADC for a particular application appears to be a formidable task, considering the thousands of converters currently on the market. A direct approach is to go right to the selection guides and parametric search engines, such as those available on the Analog Devices website. Enter the sampling rate, resolution, power supply voltage, and other important properties...

With an increasing number of devices that must be managed, the scalability of network and service management is a real challenge. A similar challenge seems to be solved by botnets which are the major security threats in today’s Internet where a botmaster can control several thousands of computers around the world. This is done although many hindernesses like firewalls, intrusion detection syste...

Online air ticket booking is a cognitively complex task even on fully-functional internet-access devices such as desktops, representing a repetitive multi-parametric search in the flights database and then browsing long lists of flights found, consisting of different carriers, prices, dates and times, to create an optimal combination of outbound and inbound flights. We present the results of re...

Designing mechanical devices, called linkages, that draw a given plane curve has been a topic that interested engineers and mathematicians for hundreds of years, and recently also computer scientists. Already in 1876, Kempe proposed a procedure for solving the problem in full generality, but his constructions tend to be extremely complicated. We provide a novel algorithm that produces much simp...

liquid-phases adsorption equilibrium of phenol onto two naturally available soils namely kalathur soil (kr) and adhanur soil (ar) were studied. the experimental data were analyzed using fourteen isotherm models, ranging from single-parametric model to multi-parametric models (up to 5 parameters) of the system. results show that in general the accuracy of models to fit experimental data improve...

Introduction of Human Development Index (HDI) by UNDP in early 1990 followed a surge in use of non-parametric and parametric indices for measurement and comparison of countries performance in development, globalization, competition, well-being and etc. The HDI is a composite index of three indicators. Its components are to reflect three major dimensions of human development: longevity, knowledg...

We propose a compact high-intensity room-temperature source of entangled photons based on the efficient second-order process of two-photon spontaneous emission from electrically pumped semiconductor quantum wells in a photonic microcavity. Two-photon emission rate in room-temperature semiconductor devices is determined solely by the carrier density, regardless of the residual one-photon emissio...

We extend the theory of parametric noise amplification to the case of transmission systems employing multiple optical phase conjugators, demonstrating that the excess noise due to this process may be reduced in direct proportion to the number of phase conjugation devices employed. We further identify that the optimum noise suppression is achieved for an odd number of phase conjugators, and that...