Theoretical and experimental investigations of the transient heat transfer parameters of constant heat flux source subjected to water flowing in the downward direction in closed channel are conducted. The power increase transient is ensured by step change increase in the heat source power. The theoretical investigation involved a mathematical modeling for axially symmetric, simultaneously developing laminar water flow in a vertical annulus. The mathematical model is based on one dimensional downward flow. The boundary conditions of the studied case are based on adiabatic outer wall, while the inner wall is subjected to a constant heat flux. The heat & mass balance equation derived for specified element of bulk water within the annulus and solved by using Laplace method to
determine the variation of bulk water temperature. The experimental investigation included a set of experiments carried out to investigate the temperature variation along the heat source for power increase transient of (5%, 10%, 15% and 20%) of its nominal value during and after reaching the steady state condition. Estimation of the boiling safety factor is predicted and compared with the theoretical values. Reliable agreement between experimental and theoretical approaches is reached. The later showed that the elapsed time required for the clad surface temperature to reach its steady state values after each transient is less than that related to bulk water temperature. New correlation for prediction of critical heat flux, CHF based on inlet water temperature and water mass flux are investigated and compared with CHF correlations obtained from previous researches. Specific recommendations concerned with preventive measured required to eliminate the effect of boiling crisis are concluded based on theoretical and experimental results related to transients setting times obtained from each case study.
The present paper aims at finding out the Variance Ratio of Trips Set Out by Scholars of Both Marrouzzeen and Baihaq .The researcher has come up with conclusion including certain findings ,one of which is that the trip is considered an essential base with high effectiveness since the old times and has been evolved .This means that the trip has been the main source of knowledge and sciences from the scholars directly .This had driven the scholars of both Baihaq and Marrouz cities .It has been noticed , though this paper, that the number of the Marrouz scholars who visited was less than those of Baihaq . The researcher has focused on their meetings or conferences and investigated what has been going on in suc
... Show MoreThis study investigates the phonotactics of English obstruent clusters in the word-final position from a markedness theory perspective among Iraqi EFL College Students whose native language, Arabic, prefers only two-member word-final obstruent cluster as a maximum. The markedness of clusters is measured depending on Iraqi EFL College Students’ utilization of the simplification strategies. This study tries to answer whether or not word-final obstruent clusters are marked or unmarked for Iraqi EFL College Students, and whether or not the markedness of the obstruent cluster increases as to its length. In order to answer these questions, a test has been distributed among 60 Iraqi EFL Fourth-Year College students, Department of English, Colleg
... Show MoreThis study has been accomplished by testing three different models to determine rocks type, pore throat radius, and flow units for Mishrif Formation in West Qurna oilfield in Southern Iraq based on Mishrif full diameter cores from 20 wells. The three models that were used in this study were Lucia rocks type classification, Winland plot was utilized to determine the pore throat radius depending on the mercury injection test (r35), and (FZI) concepts to identify flow units which enabled us to recognize the differences between Mishrif units in these three categories. The study of pore characteristics is very significant in reservoir evaluation. It controls the storage mechanism and reservoir fluid prope
The digital communication of a product of communication and information revolution. It is characterized by accurate and comprehensive in its services and its effects, which brought changes in the structure of many communities and their organizational structures. They have significant impacts on the social systems and social relations, especially in the Arab societies, which are the focus of the globalized Western media, for many reasons: economical, political , cultural and social.
According to this perception, the Arab identity has become in an encounter with big challenges by the globalized media of trade and the media, which aims to achieve greater profits because of identity and its importance to the communities. This occurs par
This research aims to clarify the role of Information Technology Competency (ITC) with dimensions' (IT Usage, IT Knowledge, and IT Operations) as an independent variable in the activation of Human Resources Management Practices (HRM Practices) as a dependent variable with dimensions' (Training and Development, Recruitment, Job Design, and Performance appraisal). Based on this, the correlation and effect relationships between the independent and dependent variables are determined by formulating two main hypotheses. There are a significant relationship and effect of IT competency with HRM practices within the dimensions. Furthermore, the scope and population of this research are the Informatics and Communications P
... Show MoreThe purpose of this study is to examine the effect of human resource diversity management practices on achieving entrepreneurship in Jordanian public universities. To achieve the aims of the study, a well-designed questionnaire was used for collecting data. The population of the study was (7433) faculty members (including different ranks such as professors, associate professors, assistant professors and lecturers) in Jordanian public universities. The study sample was selected through the use of a random sample, the questionnaire is distributed to a sample (of 400 with the percentage of 5%) selected by using a random sampling (350) copies of the questionnaire were collected, reaching about (87.5%) out of the sum total of the dist
... Show MoreBackground: A successful endodontic treatment is aimed at the sterilization of the entire pulp space. The use of extracts from Rhamnus prinoides as a novel irrigating material for root canal has not been studied . Hence, the antimicrobial efficacy of the alcoholic extract of Rhamnus prinoides as an irrigation material against E. faecalis was evaluated in comparison with the 2.5% sodium hypochlorite (NaOCL) solution used for root canals of permanent teeth. Methods: A total of 30 single-rooted human permanent teeth were thoroughly cleaned, shaped, and disinfected. Then, each tooth was subjected to a two-week infection with Enterococcus faecalis at 37 °C . Afterward, the samples were divided into three groups (10 teeth per group): 0.9
... Show MoreThis study examines the relationship between the increase in the number of tourists coming to Tunisia and GDP during the period 1995-2017, using the methodology of joint integration, causal testing and error correction model. The research found the time series instability of the logarithm of the number of tourists coming to Tunisia and the output logarithm but after applying the first differences, these chains become stable, THUS these time series are integrated in the first differences. Using the Johansson method, we found the possibility of a simultaneous integration relationship between the logarithm of the number of tourists coming to Tunisia and the logarithm of GDP in Tunisia, and there is a causal relationship in one direc
... Show MoreThe summary:
This research paper presents a standard economic study. This study aims to build an economic standard form of the investment effect in Human Capital on Economic Growth in Algeria. The study showed that there is an inverse relationship between the investment and human capital. This is expressed by expending on education and economic growth. This contradicts with the economic theory. Such matter could be explained by that expending on education does not contribute in the economic growth. This refers to that the education sector result does not employee or save jobs. Thus, it does not contribute in growth; in addition, the Algerian economy depends on petrol in the first class. This means the ab
... Show MoreThis research revolves around the study of sports press coverage to the third African Youth Games that took place in Algeria from 19 to 28 July 2018. The games featured approximately 3000 athletes from 54 countries who competed in 27 sports. Five sports were qualified for the Youth Olympic Games in Argentina. The aim of this study was to analyze the content of the Algerian newspaper Ennahar El-Djadid by focusing on the discussions of various sports activities during the event. Thus, the descriptive approach and content analysis method were adopted for this research. They were used to highlight the newspaper's interest in this sports phenomenon. The chosen study samples were ten issue numbers of Ennahar El-Djadid newspaper