Preferred Language
Articles
/
4hYYGYcBVTCNdQwCoDbN
Performance evaluation of the photovoltaic thermal system with a fin array and surface zigzag layout
...Show More Authors
Abstract<p>Solar photovoltaic (PV) has many environmental benefits and it is considered to be a practical alternative to traditional energy generation. The electrical conversion efficiency of such systems is inherently limited due to the relatively high thermal resistance of the PV components. An approach for intensifying electrical and thermal production of air-type photovoltaic thermal (PVT) systems via applying a combination of fins and surface zigzags was proposed in this paper. This research study aims to apply three performance enhancers: case B, including internal fins; case C, back surface zigzags; and case D, combinations of fins and surface zigzags; whereas the baseline smooth duct represents case A. A 2D, steady-state simulation model that took into account the impact of the convective flow of air circulating inside the PVT system in addition to radiative and convective heat losses from the front PV surface was developed and validated via previous tests. The results revealed that, under the same volume requirements, the application of surface zigzags is preferred for airflow rates of 0.06 kg/s or less, whereas the introduction of fins is preferred for higher airflow rates. The results also revealed that, of the three cases considered, the introduction of the fin–surface zigzag combination is the most effective and has the potential to improve the electrical and thermal efficiency by ~26% and 3%, respectively.</p>
Scopus Clarivate Crossref
View Publication
Publication Date
Sat May 01 2021
Journal Name
Materials Today: Proceedings
WITHDRAWN: Analyzing and measuring the impact of trade openness on the gross domestic product growth of the Iraqi economy after 2003
...Show More Authors

View Publication
Crossref (1)
Crossref
Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
The Effectiveness of Cognitive Conflict Strategy in Comprehending Reading Among the Fifth Literary Students in the Subject of Literature and Texts
...Show More Authors

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

... Show More
View Publication Preview PDF
Publication Date
Wed Oct 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Measure and analyze the relationship between oil prices and the Iraqi dinar exchange rate
...Show More Authors

In this research, we discussed and analyzed the relationship between oil prices and the U.S. dollar exchange rate in Iraq. The study adopted the descriptive analysis and econometrics analysis. The descriptive analysis refers to the rise (fall) in crude oil price lead to appreciate (depreciate) in the Iraqi dinar exchange rate, though the channel of the international reserves. The econometrics analysis is based on monthly data covered the period (December/2002 – December/2011), the unit root test, co-integration test, vector error correction model, and Granger causality test have been adopted in this research to check the existence and direction of this relationship. The results refer to the lon

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Oct 28 2022
Journal Name
Political Sciences Journal
The protest movements in Sudan and their role in the political and social transformation
...Show More Authors

This study investigates the factors that led to the outbreak of protest movements in Sudan, since Sudan’s independence in 1956 until December 2018. The study aims to identify the role of protests in bringing about political and social transformations in Sudan, besides identifying the factors that help in the success or failure of the governments that resulted from those protests, with special emphasis on the challenges of the government of the 2018 revolution. The main results of the study reveal that the December 2018 protests are the largest in term of numbers, and witness huge participation of youth and women, and the slogans raised were national and comprehensive. However, the challenges that the transitional government is going th

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Sep 17 2021
Journal Name
Political Sciences Journal
Pending issues between the federal government and the Kurdistan region (Constitutional and legal solutions)
...Show More Authors

The federal state is usually based on a number of regions because it is based on the multiplicity of political entities. The federal experiments were based on the existence of two or more regions and each federal system has its own peculiarities. Administrative authority between the federal government and local elected bodies of local people of absolute relative independence does not threaten the entity of the state according to the Constitution and the law and on a regional or reformer basis and exercise its powers within the legal scope prescribed The relationship between the federal authority and the Kurdistan region is the first level of the relationship on the real level, especially since no other region in Iraq has been formed exce

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jun 30 2022
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Adopting opportunity cost as a tool to increase tax revenue: Applied research in the General Tax Authority - Companies Division
...Show More Authors

This research seeks to try to address one of the important issues in society that prevents the state from achieving its social, economic, political and financial goals, represented by the low tax proceeds, through which it can achieve those goals. What is reflected on the tax proceeds, knowing that the General Tax Authority does not take into account the issue of analyzing the opportunity cost of corporate capital as one of the profit indicators when setting the annual controls, which leads to a decrease in the tax proceeds, and therefore the research objective will be to shed light on the importance of adopting the concept of analysis The opportunity cost by the General Tax Authority to achieve a tax proceeds commensurate with t

... Show More
View Publication Preview PDF
Publication Date
Wed Mar 01 2023
Journal Name
Human Gene
The deubiquitylase-ubiquitin-specific protease 4 absence in HeLa cells leads to a reduction in Semliki Forest virus replication
...Show More Authors

View Publication
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Wed Mar 29 2023
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Asphaltene Precipitation Investigation Using a Screening Techniques for Crude Oil Sample from the Nahr-Umr Formation/Halfaya Oil Field
...Show More Authors

Many oil and gas processes, including oil recovery, oil transportation, and petroleum processing, are negatively impacted by the precipitation and deposition of asphaltene. Screening methods for determining the stability of asphaltenes in crude oil have been developed due to the high cost of remediating asphaltene deposition in crude oil production and processing. The colloidal instability index, the Asphaltene-resin ratio, the De Boer plot, and the modified colloidal instability index were used to predict the stability of asphaltene in crude oil in this study. The screening approaches were investigated in detail, as done for the experimental results obtained from them. The factors regulating the asphaltene precipitation are different fr

... Show More
View Publication Preview PDF
Crossref (9)
Crossref
Publication Date
Tue Sep 01 2015
Journal Name
European Academic Research
Developing Students` Achievement by Using Self –Observation as a Reflective Teaching Techniques in Conversation Classes at the University Level.
...Show More Authors

The present study deals with the effect of self -observation on EFL University students` achievement in conversation classes. The process of self-observation helps the teacher to understand one’s own actions and the reactions in the process of teaching. The sample of this study is EFL students in the third stage at the Department of English Language, morning studies, College of Education /Ibn-Rushd .The sample of the study consists of (84) students distributed on experimental group(A) includes (42) students, and (42) students as control group(B). In order to achieve the aim of the study ,and to gain a closer idea about the impact of reflective teaching technique(self-observation) on the students achievement in conversation classes, a chec

... Show More
View Publication
Publication Date
Wed Jun 01 2022
Journal Name
Journal Of The College Of Languages (jcl)
The passive As a grammatical phenomenon in four selected textbooks: Das Passiv Als grammatisches Phӓnomen in vier ausgewӓhlten Lehrwerken
...Show More Authors

The research work is "The passive voice as a grammatical phenomenon in four selected textbooks". The research deals with the grammatical phenomenon passive in German. The research consists of two parts, the theoretical and the empirical part. The present research work is divided into 3 sections:

The first section includes the definition of passive, passive types, process passive, state passive, passive with modal verbs, and other types of passive. The second section provides illustrations of the four selected textbooks. The third chapter presents the passive voice in textbooks, namely German language teaching for foreigners by Dora Schulz and Heinz Griesbach, Delfin von Aufderstrasse H. and others, Em von Balme, M. and others and

... Show More
View Publication Preview PDF
Crossref