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.
In the article we consider features of official style, its functions and factors which influence the definition of the style. The topicality of the issue can be explained by rapid development of market economy which affects in its turn business correspondence. In this regard, there are a lot of cliché, terms and professionalisms appeared recently. Only correct usage of them can serve as a key to successful communication in Russian as well as other languages. This work highlights documents that are part of the diplomatic style such as declarations, credentials, notes, resolutions and other documents. The administrative style can include orders and instructions.
Аннотация.
В данной статье рассмо
... Show MoreThe research deals with the Presidents of the Christians who called themselves (Ghaltka) in the book titled (orient chirsy patriarchs) that talked about their scientific practical biography adding to) that their completeness on the position of Ghaltka with its decrees and caliphs who were contemporaries to them ,as well as their places, deaths, cemeteries and their accomplishments In accordance with the powers granted to them and also it mentions the situation of The Abbasid caliphate with them and with the sons of their sect .
Problems in the Translation of Spanish phraseology to Arabic in the Literary Text (A Comparative Study from the Perspective translatological)
Abstract
One of the most common problems facing the translator is the identification and subsequent search for correspondences of phraseological units. The importance of the phraseological competence in a foreign language is widely recognized by many authors (Howarth, Corpas Pastor, Pamies Bertran, to name a few).
We must lose our fear to recognize that the domain of the phraseology is the highest level of command of any language. The objective of the present study is to clarify the differences in UFS Spanish to Arabi
... Show Moreهدف هذا البحث الى استعمال الأسلوب الرياضي أسلوب التحليل الهرمي وتطبيقه وفق ابعاد بطاقة الاداء المتوازن في تقييم الأداء الاستراتيجي في الهيئة العامة للأثار والتراث، وتمثلت أدوات البحث باستعمال استمارات التحليل الهرمي وطبقت على معايير بطاقة الأداء المتوازن المتمثلة في (المالي، الزبائن، العمليات الداخلية، والتعلم والنمو)، وتم استهداف عينة قصدية متمثلة في رئيس الهيئة والمدراء العامون بعض من مدراء الأقسام ال
... Show MoreThe research deals with the issues related to the fixed names of God U, which are from a set of issues mentioned in the Book of Observations of the Keys Explaining the Mishkat al-Masbah by Abu Al-Hasan Al-Mubarakfory (d. 141 AH). It included five demands: the first of them is in proving and identifying the most beautiful names and divisions of God, and the second in the name, name and name. And the third: It was in their number, while the fourth: in deriving the names, is it suspensive or not? And Fifth: The Compilation of Allah’s Most Beautiful Names.
The present study aimed to identify the problems thatthe students of College of Education, for women in Iraqia university are suffering from and how to overcome them. thesample of the study contained of (392) student which forms (20%) of the basic sample which is (2180) student, distributed on the six departments of the college they have been chosen randomly and the researcher has used the descriptive analytic method by applying one contains (67) items distributed on six fields,they are as follows: study skills field, academic field, curriculums field, students- teacher relationship field, examinations field, students family field,.
The study has come with
... Show MoreThis study discussed a biased estimator of the Negative Binomial Regression model known as (Liu Estimator), This estimate was used to reduce variance and overcome the problem Multicollinearity between explanatory variables, Some estimates were used such as Ridge Regression and Maximum Likelihood Estimators, This research aims at the theoretical comparisons between the new estimator (Liu Estimator) and the estimators
In this study, the thermal buckling behavior of composite laminate plates cross-ply and angle-ply all edged simply supported subjected to a uniform temperature field is investigated, using a simple trigonometric shear deformation theory. Four unknown variables are involved in the theory, and satisfied the zero traction boundary condition on the surface without using shear correction factors, Hamilton's principle is used to derive equations of motion depending on a Simple Four Variable Plate Theory for cross-ply and angle-ply, and then solved through Navier's double trigonometric sequence, to obtain critical buckling temperature for laminated composite plates. Effect of changing some design parameters such as, ortho
... Show MoreThis study “discusses the benefit of “addition waste paper as a “new cellulose material “in mortar mixes. A partial addition of waste paper by cement weight was achieved to produce cement composite mortar. Pulp and paper is the third major industrial dumper of air, soil and water. In recent year, paper and paperboard constitute a greater portion of many countries’ urban solid discarded generation. Beside, it increases characteristic “strength due to existence “of hydrogen links “in the microstructure of “paper. Furthermore, it consume “better thermal protection. The addition percentages “of waste paper used “in this work were (5%, 10%, 15% and 20%) by “mass of cement to measure and evaluat
... Show MoreDiesel engine oil was subjected to thermal oxidization (TO) for six periods of time (0 h, 24 h, 48 h, 72 h, 96 h, and 120 h) and was subsequently characterized by terahertz time domain spectroscopy (THz-TDS). The THz refractive index generally increased with oxidation time. The measurement method illustrated the potential of THz-TDS when a fixed setup with a single cuvette is used. A future miniaturized setup installed in an engine would be an example of a fixed setup. For the refractive index, there were highly significant differences among the oxidation times across most of the 0.3–1.7 THz range.