摘要：The most important aim of nanotechnology development is to construct atomic-scale devices, and those atomic-scale devices are required to use some measurements that have ability to control and build in the range of these dimensions. A method based on super- heterodyne interferometers can be used to access the measurements in nano-scale. One of the most important limitations to increase the resolution of the displacement measurement is nonlinearity error. According to the base and measurement signals received by optical section of super-heterodyne interferometer, it is necessary for circuits to reconstruct and detect corresponding phase with target displacement. In this paper, we designed, simulated, and implemented the circuits required for electronic part of interferometer by complementary metal-oxide-semicon- ductor （CMOS） 0.5 ~tm technology. These circuits included cascade low-noise amplifiers （LNA） with 19.1 dB gain and 2.5dB noise figure （NF） at 500MHz frequency, band-pass filters with 500MHz central fre- quency and 400 kHz bandwidth, double-balanced mixers with 233/0.6pm ratio for metal-oxide-semiconductor field-effect transistors （MOSFETs）, and low-pass filters with 300 kHz cutoff frequency. The experimental results show that the amplifiers have 19.41 dB gain and 2.7 dB noise factor, mixers have the ratio of radio frequency to local oscillator （RF/LO） range between 80 and 2500 MHz with intermediate frequency （IF） range between DC to 1000 MHz, and the digital phase measurement circuit based on the time-to-digital converter （TDC） has a nanosecond resolution.

摘要：In this paper the Delaware Method published in 1963 is analyzed and upgraded with using correction factors which take into account the undesirable currents of the mean flow. However, this method presents graphically these correction factors which imply an impediment to fulfill the software calculations. Thus, the equations corresponding to the correction factor equations and a Fortran 77 numerical program were established. This system is given to explore different design alternatives in order to find the optimal solution to each proposed problem. The results of this work was a simple software that can perform calculations with the introduction of parameters depending only on the geometry of the heat exchanger, i.e., geometry, temperature and fluid characteristics eliminating the human errors and increasing the calculations speed and accuracy.

摘要：Power-line networks are designed to deliver electricity. They reach most of the domiciles and other buildings nowadays, so most of the people have access to it. On the other hand the backbone for the communications networks is not available in all countries especially the developing ones. A high cost and changing the design for the networks may be needed to construct this backbone. If data can be transmitted over the power-line networks, a recognized cost and time save can be achieved. In Egypt, the infrastructure is not always available for constructing a communications network backbone due to the already designed buildings before the need for these backbones. In this paper, we overcome this problem by designing a reliable Power-line Modem that operates safely on the low voltage grid. The modem is based on the Direct Sequence Spread Spectrum technique. It uses the mains zero crossing as an efficient way for the synchronization between the transmitter and the receiver. The Modem takes into account the problems of the Power-line including noise, attenuation and impedance dismatching.

摘要：In this paper, a quantum cascade photodetector based on intersubband transitions in quantum wells with ability of detecting 1.33 μm and 1.55 μm wavelengths in two individual current paths is introduced. Multi quantum wells structures based on III-Nitride materials due to their large band gaps are used. In order to calculate the photodetector parameters, wave functions and energy levels are obtained by solving 1-D Schrodinger–Poisson equation self consistently at 80 ?K. Responsivity values are about 22 mA/W and 18.75 mA/W for detecting of 1.33 μm and 1.55 μm wavelengths, respectively. Detectivity values are calculated as 1.17 × 107 (Jones) and 2.41 × 107 (Jones) at wavelengths of 1.33 μm and 1.55 μm wavelengths, respectively.

摘要：This paper demonstrates the analysis of antenna pattern and gain for different designs of full-wave dipole antenna feeding techniques. Seven such techniques were studied and analyzed;symmetrical dual feeding in phase, symmetrical dual feeding out of phase, asymmetrical dual feeding in phase, asymmetrical dual feeding out of phase, symmetrical triple feeding in phase and symmetrical triple feeding out of phase. Symmetrical dual feeding in phase produced high gain as compared to the single and center-fed antennas. An improvement of about 3 to 3.5 dB was achieved comparing to center tap fed and off center fed. It was found that an asymmetrical dual feeding in-phase provides good performance, considering the directivity, pattern, and input impedance. A 2.46 dB gain has been attained. It was found that a symmetrical triple feeding provides an overall best performance with respect to gain, radiation pattern, beam width and input impedance.

摘要：This article explores, through a case study, measures of energy efficiency in data processing centers. An analysis of this case demonstrates how the design criteria could improve the rate of consumption in IT centers, which is currently the second most contaminating industry on the planet, and is the responsible for 2% of CO2 emissions, surpassed only by the aeronautical industry. The present and future situation of IT center energy consumption and associated environmental effects is analyzed, and also looks at how state-of-the-art technology, correctly implemented, could ensure significant rationalization of data processing center energy consumption. The article will examine optimization techniques, specific problems and case studies.

摘要：已经开发了的ABSs系统改善了突然制动和特别是滑动路面状况时车辆控制。这样的控制目标是在保持车辆合适稳定性及可操纵性和缩短车辆刹车距离情况下在要求的方向增大车轮的牵引力。本文提出了ABSs系统优化的模糊控制器。从保持其车轮滑动值为目标函数获得车轮最大的牵引力和车轮最大的减速度。采用遗传算法优化模糊系统的全部组件。采用误差数整体优化方法收敛接近最优点。仿真结果表明快速收敛和对不同路况的控制器的最好性能。

摘要：The voltage uprating of existing overhead lines is an interesting solution for increasing the transmission of electricity, especially in areas where it is difficult to build new lines. If a line is uprated with minor changes of its design and without improvement of the grounding electrodes of towers, its lightning performance remains unchanged. The consequence is that the uprated line will have a lightning flashover rate very high compared to an overhead line of same nominal voltage but of standard design. One attractive solution to solve this problem is to use line arresters. The goal of this paper is to study the use of line arresters to achieve a satisfactory lightning performance of an overhead line uprated from 225 kV to 400 kV without major design modifications. In order to compare different strategies of line arrester installation the flashover rate is calculated based on a software able to launch automatically EMTP-RV. The software named LIPS has been developed under the cover of a partnership between Hydro-Quebec, RTE and EDF.

摘要：The present work is a study on the influence of temperature and the velocity of air on the drying kinetics of pineapple slices. The main objective is to define from this drying kinetics rules to help a designer choose an adequate principle or drying configuration and optimize the design of dryers adapted to the use of it. The experiments were made in an electric dryer using a parallel flow system. The air was used at three different temperatures （40, 50 and 60 ~C） and at four different velocities （0.27, 0.5, 1 and 1.8 m/s） during the experiment. The results show that an increase of 10 ℃ of the drying temperature reduced the drying time by 45% and increased the drying velocity by 30%. On the set of air velocities tested, it was noticed that the influence of air velocity on drying was more striking at the beginning than at the end of the drying process （variation of less than 20%）. Whatever the variation of parameters during the drying process, the best performance was observed when the products water content during the drying process was between 50% and 80%.