The present study involves experimental analysis of the modified Closed Wet Cooling Tower (CWCT) based on first and second law of thermodynamics, to gain a deeper knowledge in this important field of engineering in Iraq. For this purpose, a prototype of CWCT optimized by added packing under a heat exchanger was designed, manufactured and tested for cooling capacity of 9 kW. Experiments are conducted to explore the effects of various operational and conformational parameters on the towers thermal performance. In the test section, spray water temperature and both dry bulb temperature and relative humidity of air measured at intermediate points of the heat exchanger and packing. Exergy of water and air were calculated by applying the exergy destruction method on the cooling tower. Experimental results showed a significant performance improvement when using packing on the CWCT. It can be observed that the thermal efficiency for the CWCT with packing under a heat exchanger and CWCT with packing above the heat exchanger are approximately 40% and 25% higher than that of the CWCT without packing respectively. As another part of the experiment results, it is indicated that the exergy destruction is directly proportional to air flow rate, cooling water flow rate, inlet cooling water flow rate and inlet Air Wet Bulb Temperature (AWBT) whereas, it is inversely proportional with spray water flow rate. In comparison with the cooling capacity of the tower, it was found that the exergy destruction approximately less than 20%. Exergy efficiency behavior is inversely proportional with the behavior of the exergy destruction. Empirical correlations are obtained to predict water film heat transfer coefficient and air-water mass transfer coefficient considering the influences of operational parameters.
Manuscript (Tuhfat Al-Ashaba and the Nuzha Al-Kulbab) by Ahmed bin Ibrahim Al-Hanafi Al-Suruji (d.710 AH / 1310 AD), one of the important manuscripts as an encyclopedia characterized by the diversity of its topics
تتطلب كرة القدم الحديثة تطوير الصفات البدنية والمهارية للوصول باللاعب إلى لمستويات العليا، ولما كانت هذه الصفات مرتبطة مع بعضها البعض، فانها تتطلب ان يتم تطويرها معا في نفس الوقت دون تنمية كل صفة على حده، وإن توافر الحد الأدنى من الصفات البدنية كمتطلبات أساسية للأداء المهاري يعتبر الهدف الأساسي للتخطيط لأي برنامج تدريبي، وإن الصفات البدنية لها مفهوم شاسع وواسع الاستعمال في مجال البحوث الرياضية، وقد أعطيت ع
... Show MoreThe study is dealing with an application reengineering process clean solar cells in the Ministry of electricity, as aimed at the possibility of the applicability and impact of re-engineering to achieve the level of performance of the Ministry's operations, with the application of the cleaning process solar cells, developed, improved and found a correlation, statistically significant effect between variable re-engineering and performance as well as the application of process reengineering clean solar cells:1- Before the re-engineering process the total time for cleaning up and solar cell 20 minutes and number of columns performed per day 24 columns and total columns750 which were completed per month that re
... Show Moreهدف البحث إلى إعداد تدريبات الثبات المحوري باالنقباض المتحرك لالعبين الشباب بكرة القدم، والتعرف على تأثير تدريبات الثبات المحوري باالنقباض في التوازن المتحرك والقوة المميزة بالسرعة للرجلين والمناولة المتوسطة لالعبين الشباب بكرة القدم، واعتمد المنهج التجريبي بتصميم المجموعتين ً التجريبية والضابطة على عينة بلغت )24 ( العبا بأسلوب ً من فئة الشباب بكرة القدم اختيرت عمديا الحصر الشامل وبنسبة )100 %( من نادي الشرط
... Show Moreاهمية البحث هي مرحلة نمو وبناء اجهزة الجسم للاعبين الاشبال واعداد تدريبات بأسلوب التدريب الدائري لبناء التحمل لتطوير بعض القدرات الحركية والمهارية لدى اللاعبين الاشبال بكرة القدم , حيث لاحظت الباحثة ضعف في مستوى الاداء الحركي ارتأت اعداداً بدنيا ومهارياً منذ مرحلة البناء الأولى للاعب الفئات العمرية , واستخدم الباحث المنهج التجريبي بالاختبار القبلي والبعدي للمجموعتين التجريبية والضابطة لملائمته لطبيعة ال
... Show MoreThe present study included the microscopic and molecular identification of Entamoeba histolytica by using specific primers to detect four virulence factors possessed by Entamoeba histolytica. Virulence factors included Active Cysteine proteinase, Galactose/N-acetyl-D-galactose-lectin, Amoeba pore C and Phospholipase. Titanium dioxide nanoparticles (TiO2NPs) were synthesized from Pseudomonas aeruginosa which producing Pyocyanin pigment as a reducing agent to form it. After that we studied the ability ofTiO2NPs to inhibit virulence factors production and curing the genes responsible for encoding them by using four different dose 2 ,3, 4, 6 mg/Kg and administered by intraperitoneal injection
... Show MoreThe study is carried out by using personal dosimeters (film badge). The films are irradiated to absorbed dose of range (0.01-10000 rad). The calibration curves are drawn by using the ordinary method taking into account the filtration effects in three regions (D (Pb/Sn),D(Du),D(300). The calibration films are stored in ambient condition. It is found that the optical density increases, which is attributed to the photodegradation of the films may induce localized states in the energy gap causing increasing in optical absorption, but optical density decreases, which attributed to the photodegradation of the films may cause some cracks at the film surface during the first month, whereas at the rest months we see clear stability in optical d
... Show MoreABSTRACT
Critical buckling temperature of angle-ply laminated plate is developed using a higher-order displacement field. This displacement field used by Mantari et al based on a constant ‘‘m’’, which is determined to give results closest to the three dimensions elasticity (3-D) theory. Equations of motion based on higher-order theory angle ply plates are derived through Hamilton, s principle, and solved using Navier-type solution to obtain critical buckling temperature for simply supported laminated plates. Changing (α2/ α1) ratios, number of layers, aspect ratios, E1/E2 ratios for thick and thin plates and their effect on thermal
... Show MoreIn this investigative endeavor, a novel concrete variety incorporating sulfur-2,4-dinitrophenylhydrazine modification was developed, and its diverse attributes were explored. This innovative concrete was produced using sulfur-2,4-dinitrophenylhydrazine modification and an array of components. The newly created sulfur-2,4-dinitrophenylhydrazine modifier was synthesized. The surface texture resulting from this modifier was examined using SEM and EDS techniques. The component ratios within concrete, chemical and physical traits derived from the sulfur-2,4-dinitrophenylhydrazine modifier, chemical and corrosion resistance of concrete, concrete stability against water absorption, concrete resilience against freezing, physical and mechanical p
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