Vol. 13 No. 3 (2005)
Articles
Abstract: . Abstract: • In this paper the SnO2 will be examined to be used as a transparent antireflection coating with the n –type silicon wafer to fabricate the deposited SnO2 silicon Solar cell using vacuum evaporation technique. This SnO2 layer is simultaneously an antireflecting coating and a transparent upper contact. The oxidation of the Si surface takes place simultaneously with the evaporation process. A semiconductor – insulator – semiconductor (SIS) structure was obtained in such a way. The photoelectrical parameters of such SIS system of AM 1.5 conditions are: the short circuit current 18.5 mA/cm2, the open circuit voltage 0.48 V and the efficiency is 7.0%. The subgap response of the resulted structure is particularly strong and extends to wavelength up to 1100nm
Abstract: Abstract The present study defines the research problem as a reconsideration or reformulation of a scientific approach to study of the relation(s) between the transparency of the individualistic style and the collective styles in Islamic architecture. The research has adopted a literary approach in its analysis namely: Riffaterre structure approach and Yaul’s statistical measurement. Both styles have been compared for differences so as to find out whether there is a complementary relation between both styles or there is a divorce between
Abstract: Abstract The static Synchronous Compensator (STATCOM) is a solid-state shunt device that generates or absorbs reactive power and is one member of a family devices known as Flexible AC Transmission System (FACTS) devices. It is superior to the static VAR Compensator (SVC) in many ways. In this work it is suggested to use the (STATCOM) in the existing H.V. Iraqi North Region National Grid (INRNG) for the first time. The best location of the (STATCOM) is obtained using load flow study which is also used to determine the optimal value of the reactive power needed at different load conditions. The paper discusses a method of optimizing the operation of the (STATCOM) using intelligent techniques. The method uses the Artificial Neural Network (ANN). The obtained results using load flow program are considered as the input data to train the (ANN). Then any value within the training data limit can be used to get the optimal value of the (STATCOM) output. The data of the (INRNG) for the year 2001 is used to verify the validity of the proposed method
Abstract: Abstract Mosul city suffers from high water tables. This problem appears clearly during the rainy season. In this research thirty wells were chosed in an area in Mosul city on both sides of the Tigris river. A topographical map was prepared after surveying the area above the mean sea level. Then the water levels in these wells are measured every month during the rainy season (2001 -2002). The sources of ground water recharge were determined.The computer program ( surfer 32) is used for preparing contour maps. Also the seasonal variations of the ground water levels were studied. The results show that the rain was the main source for recharging the ground water. The maximum levels of the water table in the wells occurred in March and minimum levels in October. In 20% of the wells, the water levels less than one meter from the surface of the ground. The ground water moves in both sides of the study area toward Tigris river. Different solutions were proposed to minimize the water table in the area under study
Abstract: Abstract The current system called Expert System for Analysis and Control of Water Hammer Problems “ESACWHP” is developed to help engineers in the design and analysis of water hammer problems using the characteristic method with aid of the programming language called Visual Basic. Results obtained from the developed of “ESACWHP” show good agreement with that solved by traditional lengthy methods, in addition it is capable of handling more variables. The system is recommended to be used for analysis and design.
Abstract: ABSTRACT An Electro-Cardio-Graph (ECG) is a device that records the electrical activity of the heart. Skin electrodes placed at designated locations on the body collect ECG measurement information, and from these waveforms different information on heart condition can be derived. This paper discusses the design and implementation of a single-channel ECG (three-electrode) circuit with a bandwidth of (0.5-100) Hz for patient monitoring purposes. The front end of an ECG must be able to deal with weak signals ranging from few microvolts to few millivolts. An analogue ECG amplifier is designed and implemented using instrumentation amplifier (IA) followed by band pass filter (BPF), then by notch filter (NF) to minimize noise affecting the signal, and a right leg drive circuit (RLDC). . The ECG data is recorded and analyzed with greater flexibility using personal computer. The (ALS 4000) PC-sound card is used as a data acquisition device. The Matlab program (version 6.5) is employed to acquire data from sound card then digitally processing the signal in order to display the ECG signal on a PC monitor.