The purpose of this study is to demonstrate a simple high sensitivity vapor sensor for propanol ((CH3)2CHOH). A free space gap was employed in two arms of a Mach-Zehnder interferometer to serve as the sensing mechanism by adding propanol volume (0.2, 0.4, 0.6, 0.8, and 1) ml and to set the phase reference with a physical spacing of (0.5, 1, 1.5, and 2) mm. The propagation constant of transmitted light in the Mach-Zehnder interferometer’s gap changes due to the small variation in the refractive index inside sensing arm that will further shift the optical phase of the signal. Experimental results indicated that the highest sensitivity of propanol was about 0.0275 nm/ml in different liquid volume while highest phase shift was 0.182×103 in liquid volume 0.2 ml for spacing 1 mm.
The present work includes design, construction and operates of a prototype solar absorption refrigeration system, using methanol as a refrigerant to avoid any refrigerant that cause global warming and greenhouse effect. Flat plate collector was used because it’s easy, ninexpensive and efficient. Many test runs (more than 50) were carried out on the system from May to October, 2013; the main results were taken between the period of July 15, 2013 to August 15, 2013 to find the maximum C.O.P, cooling, temperature and pressure of the system. The system demonstrates a maximum generator temperature of 93.5 oC, on July 18, 2013 at 2:30 pm, and the average mean generator temperature Tgavr was 74.7 °C, for this period. The maximum pressure Pg
... Show More
(3)
The effect of high energy radiation on the energy gap of compound semiconductor Silicon Carbide (SiC) are viewed. Emphasis is placed on those effects which can be interpreted in terms of energy levels. The goal is to develop semiconductors operating at high temperature with low energy gaps by induced permanent damage in SiC irradiated by gamma source. TEACO2 laser used for producing SiC thin films. Spectrophotometer lambda - UV, Visible instrument is used to determine energy gap (Eg). Co-60, Cs-137, and Sr-90 are used to irradiate SiC samples for different time of irradiation. Possible interpretation of the changing in Eg values as the time of irradiation change is discussed
Abstract. This study presents experimental and numerical investigation on the effectiveness of electrode geometry on flushing and debris removal in Electrical Discharge Drilling (EDD) process. A new electrode geometry, namely side-cut electrode, was designed and manufactured based on circular electrode geometry. Several drilling operations were performed on stainless steel 304 using rotary tubular electrodes with circular and side-cut geometries. Drilling performance was characterized by Material Removal Rate (MRR), Electrode Wear Rate (EWR), and Tool Wear Ratio (TWR). Dimensional features and surface quality of drilled holes were evaluated based on Overcut (OC), Hole Depth (HD), and Surface Roughness (SR). Three-dimensional
... Show More
(8)
(10)
(7)
The study of vegetative change of cities is one of the most important studies related to human life because of its direct correlation with the temporal conditions that occur. These include the economic problems that force people to move and look for job opportunities in the city, which leads to an increase in the population density of cities, especially for cities with an important economic and administrative location as in the capital city of Baghdad. In this study, the effect of the increasing in population density was analyzed on the urban planning of Baghdad city. The decreasing in vegetation was due to the increasing of urban areas on the outskirts of the city, which led to an increase in its area. Moreover, urban cities increased t
... Show More
تعد الثقافة التنظيمية في المجال االداري وكذلك الرياضي من المفاهيم الحديثة لذا وجب التعرف عليها من عدة اتجاهات لمعرفة تكوينها واب عادها والنظريات التي تناولتها لتكوين رؤية تختلف عن االخرين لما لها من دور مهم ونافع في مختلف المؤسسات ومنها االتحادات الرياضية، ولعل لعلوم الرياضة واالختبار والقياس على وجه الخصوص الدور الرئيس في المساعدة بإيجاد وسيلة علمية وتطبيقها على االعضاء لمعرفة انماط الثقافة لديهم ومن
... Show More
(1)
Remote surveying of unknown bound geometries, such as the mapping of underground water supplies and tunnels, remains a challenging task. The obstacles and absorption in media make the long-distance telecommunication and localization process inefficient due to mobile sensors’ power limitations. This work develops a new short-range sequential localization approach to reduce the required amount of signal transmission power. The developed algorithm is based on a sequential localization process that can utilize a multitude of randomly distributed wireless sensors while only employing several anchors in the process. Time delay elliptic and frequency range techniques are employed in developing the proposed algebraic closed-form solution.
... Show More
(2)
(2)
We describe the use of on-chip buckled-dome Fabry–Perot microcavities as pressure sensing elements. These cavities, fabricated by a controlled thin-film buckling process, are inherently sealed and support stable optical modes (finesse
(10)
(11)
تعد المواطنة مبدأ ومرجعية دستورية وسياسية لا تلغي عملية التدافع والتنافس في الفضاء الاجتماعي ، نضبطها بضوابط الوطن ووحدته القائمة على احترام التنوع وليس على نفيه ، والساعية بوسائل قانونية وسلمية للافادة من هذا التنوع في تمتين قاعدة الوحدة الوطنية ، بحيث يشعر الجميع بان مستقبلهم مرهون بها ، وانها لاتشكل نفيا لمحو حياتهم ، وانما مجالا للتعبير عنها بوسائل منسجمة وناموس الاختلاف وافاق العصر ومكتسبات الح
... Show More