Abstract

One of the most suitable materials to be used in latent heat thermal energy storage system (LHTES) are Phase change materials, but a problem of slow melting and solidification processes made many researchers focusing on how to improve their thermal properties. This experimental work concerned with the enhancing of thermal conductivity of phase change material. The enhancing method was by the addition of copper Lessing rings in phase change material (paraffin wax). The effect of diameter for the used rings was studied by using two different diameters (0.5 cm and 1cm). Also, three volumetric percentages of rings addition (3%, 6% and 10%) were tested for each diameter. The discharging process was done with

The objective of this study is to apply Artificial Neural Network for heat transfer analysis of shell-and-tube heat exchangers widely used in power plants and refineries. Practical data was obtained by using industrial heat exchanger operating in power generation department of Dura refinery. The commonly used Back Propagation (BP) algorithm was used to train and test networks by divided the data to three samples (training, validation and testing data) to give more approach data with actual case. Inputs of the neural network include inlet water temperature, inlet air temperature and mass flow rate of air. Two outputs (exit water temperature to cooling tower and exit air temperature to second stage of air compressor) were taken in ANN.

The aim of the current study is to identify the effectiveness of cognitive conflict strategy in comprehending reading among literary fifth students in literature and literature texts. The researcher uses experimental method with partial control. The sample consisted of (80) students distributed into control and experimental groups. The scientific material, the behavioral goals, the teaching plans, and the instrument of the research have been prepared (reading comprehension test) by the researcher.

The instrument's validity and reliability have been calculated and then applied to the sample. After treating the data statistically by using SPSS, the results have revealed that there is a statistically significant difference at the si

                The current research aims to show the impact of the international auditing standard IAS 540 in reducing income smoothing practices in Iraq. To achieve the objectives of the research, the researcher adopted a questionnaire for a sample of auditors in Iraq. Where 60 forms were distributed and after the questionnaire was retrieved and statistical analysis was done using the SPSS program, The research reached a number of results, the most important of which are: the existence of a statistically significant effect of the application of the international auditing standard IAS 540 in reducing income smoothing practices, The research recommended the necess

The aim of the research is to identify the imaginative thinking skills included in the content of the chemistry textbook for fifth-grade students in biological sciences at the preparatory stage, which is approved by the Ministry of Education, General Directorate of Curricula in the academic year 2020-2021. To achieve the objective of the study, the researcher depends on the previous studies in the field and content of imaginative thinking skills for preparing a list of skills that includes (3) essential skills and (11) sub-skills and (28) items related to all skills. The researcher adopted the analytical descriptive approach because of its appropriation of the goals of the research. Then the researcher analyzed the content of the book de

The research seeks to identify the correlation relationship between strategic intelligence and fifth preparatory students’ achievement in mathematics. To achieve this objective, stratified random sampling were used based on participants’ gender and the branch of study. The sample consisted of (200) male and female fifth preparatory students for both (literary and scientific branch) who were displaced to Arbil city in Iraq for the academic year 2016-2017. As for research tool, the researcher administered strategic intelligence test to the study sample in the second semester which was designed by Ibrahim (2017), it includes (30) items divided into five domains (predictability, organized thinking, future view, motivation, and pa

ان الهدف من هذا البحث هو تحليل كتاب الفيزياء للصف الخامس العلمي للمرحلة الاعدادية في ضوء معايير تصميم وانتاج الانفوجرافيك. ويتم التحقق من هدف البحث من خلال الاجابة عن الاسئلة الاتية: ما هي المعايير التي يمكن في ضوئها تقويم كتاب الفيزياءلصف الخامس العلمي؟ ما النسبة الواجب توافرها لمعايير تصميم وانتاج الانفوجرافيك في كتاب الفيزياء لصف الخامس العلمي؟ ما مدى توفر معايير تصميم وانتاج الانفوجرافيك في كتاب الفيزي

The aim of the research is to identify the role of public relations in promoting tourism by the Palestinian tourism and travel companies in Gaza from the public relations officer’s point of view in those companies.
The researcher used the descriptive analytical method as the most appropriate for such studies and implemented the questionnaire as a tool to obtain the required data from the respondents.
The Researcher reached several conclusions:
1- There is a low percentage of women working in the field of public relations in Palestinian tourism establishments in the Gaza Strip, where the percentage did not exceed 5%.
2- The interpersonal communication counted as one of the elements of integra

يهدف البحث الحالي التعرف على اسباب السرقة لدى تلاميذ المرحلة الابتدائية كما يراها معلموهم ومعلماتهم ، وعن الاساليب المتبعة في معالجة ظاهرة السرقة من قبلهم ، ولقد شملت عينة البحث على ( 200 ) فرداً من معلمي ومعلمات تلاميذ المرحلة الابتدائية في مدينة المكلا للعام الدراسي ( 2004 ـ 2005 ) ، وقد استخدمت الباحثة استبياناً أعدته كأداة للوصول الى اهداف البحث بعد ان تم التأكد من صدقه وثباته ، استخدمت الباحثة معادلة ارتب