[en] In this paper we present an architectural design and analysis of a programmable image processor, nicknamed Snake. The processor was designed with a high degree of parallelism to speed up a range of image processing operations. Data parallelism found in array processors has been included into the architecture of the proposed processor. The implementation of commonly used image processing algorithms and their performance evaluation are also discussed. The performance of Snake is also compared with other types of processor architectures. (author)

[en] The miracle chip microprocessor represents a quantum leap in the technology of mankind, a development that over the past decade has acquired the significance in industrial automation and has led PCs to become workhorses in the everyday industrial environment. The communication of Microprocessor to the outside world depends upon the I/O devices and Interfacing Techniques. This work deals with the technique of interfacing Intel, Motorola, and Zilog processors, with their respective I/O devices (PPI, PIA, and PIO) for parallel data transfer. The PC based trainer is specifically designed to demonstrate how a particular microprocessor selects and initializes an I/O device, what hardware chips are necessary, what software instructions are used, and how various data transfers take place. Many practical exercises can be developed in software to expose students to more complex applications using PC-based Programmable Peripheral I/O Devices Trainer. (author)

[en] Holographic environment is based on high-equipped Multimedia information systems. These are based on the evolving powers of computers to handle huge volume of information. Holographic environment is a simulated environment that allows the user to touch and interact with projections, which are derived from the distant real environment. A new communications technology is being developed that will facilitate to interact inside a simulated environment, even if you are thousands of miles apart. This is done with enhancing the electro-holography, which is the computer based generation of diffraction fringes from 3D input data and the display of the reconstructed object in real-time. This research paper presents the design and development of holographic environment for reduction of distances in business and educational applications. The Holographic Environment development with the use of multimedia information systems is discussed. In Particular the characteristics of holographic data and the current research results in the area of real time holographic display systems are spanned. The Technical components of holographic system are also encountered. Finally, issues of improvement in efficiency of Holographic Environments by compression of data are presented along with its utilization for educational and business applications. (author)

[en] Air pollution in Dhaka City has become an alarming issue in recent days. Unless necessary measures are taken for the abatement of air pollution, it is going to bring adverse consequences inhuman lives. The aim of this work is to measure air pollutants of different parts of Dhaka City and also to determine breathing air quality. The field experiments revealed the concentrations of RDP (Respirable Dust Particle) suspended in air, Nitrogen oxides (NO/sub x/) and Sulfur dioxides (So/sub 2/). A respirable dust sampler was employed to measure the concentrations of air pollutants. This work also covers an in depth study of types of air pollutants, sources, effects on human and materials and ways of controlling air pollution. This investigation is an endeavor to start a systematic collection of technical information with reliable chemical analysis using available equipment. (author)

[en] Photosensitive gaseous detectors provide an attractive solution for photon localization over very large areas and under high illumination flux. They offer single photon sensitivity and possibility of operation under very intense magnetic fields normally encountered in high energy physics experiments. A large variety of photosensitive gaseous detectors has been developed over the last two decades and is successfully employed in numerous experiments in high energy and nuclear physics, plasma diagnostics and medical imaging. Here we discuss the recent progress made in UV-photo cathodes capable of operation under gas multiplication and visible photo cathodes providing, for the first time, the possibility of operating gaseous detectors in the visible range. (author)

[en] Determination of net recharge to the groundwater is of prime importance while managing irrigation and drainage system of the area. Without knowing the groundwater and recharge both systems irrigation and drainage, are two sides of one coin may mislead. In order to determine net recharge to the groundwater, the data of important parameters such as irrigation delivery at head of the channel, total losses, crop water requirement, water table fluctuation, operation hours of tube wells and surface drain discharge and shallow as well as deep ground water quality were measured for Rabi season (November, 1999 to March, 2000). Using different approaches such as actual observation of inflow and outflow components, change of water table and SURFER (Software), the net recharge was determined. Results have shown that in Rabi season, the groundwater is recharged except in the month of January (canal closure period) and March, depending on various irrigation and drainage factors, which are complex. Shallow groundwater quality was observed good and use able due to recharge by surface water. About 41 % of command area was under shallow water table with salinity of water 300-800 ppm, 29 % was under water quality of 800-1300 ppm, 9% was between 1800-2300 ppm and rest 12% of the area was observed more than 2300 ppm. The quality of fresh water pump lifting water from the depth of 40 ft was up to 2400 ppm and deeper pump water quality was about 25000 ppm in scavenger and saline tube wells. Average water table was about 3.0 ft and fluctuation was between 2.38-3.8 feet in spite of running the tube wells.(author)

[en] An attempt has been made to investigate the effect of post heat treatment of processes on torsional behavior of carbonized SAE 1020 steel, with 0.2 %-0.25% C, 0.6%-0.7% Mn, 0.15%-0.25% Si, 0.035% S, 0.035% P. All the specimens were heated up to 920 degree C temperature for fully austenitizing, and then different heating and cooling cycles were conducted just to alter the case core hardness. Hardness profile and Torque-Twist data was measured after different post heat treatments. It was found that with increasing 3.85% case hardness the torque efficiency also increased up to 55%, whereas no significant effect of core hardness on the torque has been revealed. (author)

[en] Thermal recovery is the most mature technology available for (EOR) Enhanced Oil Recovery). Thermal processes are either heat-injection processes or in-situ heat generation processes, and are particularly applicable to the recovery of heavy oils and tar sands. In-situ heat generation processes require combustion within the reservoir. These processes are categorized as either forward combustion, reverse combustion, or wet combustion. A high pressure disc type reactor has been used to study the effect of the main variables thought to affect the kinetics of heavy oil in a consolidated porous media on combustion. The processes observed were very dependent on the conditions used. The rate of oxygen consumption and carbon burning rate increased when the air flux is increased. This behavior is attributed to the overall increase in the rate of oxidation reactions. When the heating rate was reduced from 5 degree C min/sup -1/ to 1.5 degree C min/sup-1/ with constant inlet flux, LTO (Low Temperature Oxidation) reactions were found more significant. In addition, the rate of fuel burning reaction HTO (High Temperature Oxidation) decreased with decreased heating rate. The change in the rate of the fuel burning reaction is attributed to the change in the nature of the fuel burnt in a consolidated formation. (author)

[en] In order to examine the feasibility of wind energy for water pumping in Bangladesh, an experimental investigation of performance characteristics of horizontal axis wind turbines has been conducted. Wind characteristics of various regions of Bangladesh have been analysed and hence a compatible design of horizontal axis wind turbine applicable to the pump has been suggested. The wind data collected by the meteorological department of Bangladesh for a period 16 years of 20 stations at different heights between 5m and 10m have been converted to 20m hub-height using power law. From these data monthly average speeds have been calculated. It is observed that for few regions of Bangladesh, there is reasonable wind speed available throughout the year to extract useful power. Considering a particular prospective region of Bangladesh a wind turbine has been designed for water pumping. The design incorporates the generalized procedure for determination of rotor and pump sizes. Thus it can be also used for any other region as well. In this paper, a generalized design for Bangladesh, a nomogram and an empirical relation have been developed for the rotor and the pump size for a particular region of Bangladesh.(author)

[en] For the simulation of transient sediment transport equation simultaneously with Navier-Stokes equations, a finite element numerical procedure has been established using multi-step technique. This technique is based on the Taylor-Galerkin method which adopts and time discretization in Taylor-expansion series form, prior to the spatial Galerkin discretization and leads to second order time-stepping procedure of considerable computational accuracy and efficiency. The pressure-correction method is employed to account for the incompressibility constraint, which decouples the velocity and pressure terms of the momentum equations and implies the consideration of a Poisson equation for the pressure of each time-step. (author)