Preferred Language
Articles
/
joe-1606
Numerical Study of Thermal Conductivity Effect on The Performance of Thermal Energy Storage
...Show More Authors

In this study, the effect of the thermal conductivity of phase change material (PCM) on the performance of thermal energy storage has been analyzed numerically. A horizontal concentric shell-and-tube latent heat thermal energy storage system (LHTESS) has been performed during the solidification process. Two types of paraffin wax with different melting temperatures and thermal conductivity were used as a PCM on the shell side, case1=0.265W/m.K and case2=0.311 W/m.K. Water has been used as heat transfer fluid (HTF) flow through in tube side. Ansys fluent has been used to analyze the model by taking into account phase change by the enthalpy method used to deal with phase transition. The numerical simulation assumptions were three-dimensional, transient, and laminar flow was used. The result for the PCMs of performance, temperature distribution, and liquid fraction during the discharge process were compared to each other. Furthermore, the Nusselt number was analyzed. The result showed that the increase in thermal conductivity of PCM reduces the time of the solidification process by 20%. The performance of LHTESS for case 2 is 63.2%, whereas for case1 is 54.6%.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Feb 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Study the reality of vocational education in the province of Basra Applied statistical study for the period 2004/2005 – 2010/2011
...Show More Authors

         Vocational education is the basis of contemporary educational movement that aims at satisfying human needs. Societies can develop their human resources via setting programs for the working class as an aspect of the comprehensive national development. Vocational education is the main source of technical cadres the Iraqi labor market requires of the vocational preparatory schools to provide after three years of schooling.

        The vocational schools of the governorate of Basra have a number of problems that lead to the lack of proficiency of their graduates. This study is an attempt to identify these problems or obstacles

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Feb 01 2019
Journal Name
Sci.int.(lahore)
TIME MANAGEMENT AND ITS RELATIONSHIP TO THE STAFF PERFORMANCE IN THE FACULTIES OF PHYSICAL EDUCATION AND SPORTS SCIENCES AT UNIVERSITY OF BAGHDAD
...Show More Authors

The study aimed to identify the importance of time in the Faculties of Physical Education and Sports Sciences at the University of Baghdad, as well as to identify the relationship between time management and the level of staff functional performance. The research population consisted of the staff members who work in the Faculties of Physical Education and Sports Sciences for Girls in Al-Jadriya for the academic year 2017-2018. A random sample of 50 staff members from each faculty were selected, that is the total number was (100) staff members. The researchers identified the concept of time management and functional performance, after that a questionnaire consisting of (39) statements and (6) parts presented to a specialized group of experts

... Show More
Publication Date
Thu Sep 29 2022
Journal Name
Al–bahith Al–a'alami
Factors Affecting the Professional Performance of Editors of The News in Iraqi Satellite Channels - A research drawn from a Master Degree thesis
...Show More Authors

Information pollution is regarded as a big problem facing journalists working in the editing section, whereby journalistic materials face such pollution through their way across the editing pyramid. This research is an attempt to define the concept of journalistic information pollution, and what are the causes and sources of this pollution. The research applied the descriptive research method to achieve its objectives. A questionnaire was used to collect data. The findings indicate that journalists are aware of the existence of information pollution in journalism, and this pollution has its causes and resources.

View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Jan 08 2019
Journal Name
Science International (lahore)
TIME MANAGEMENT AND ITS RELATIONSHIP TO THE STAFF PERFORMANCE IN THE FACULTIES OF PHYSICAL EDUCATION AND SPORTS SCIENCES AT UNIVERSITY OF BAGHDAD
...Show More Authors

The study aimed to identify the importance of time in the Faculties of Physical Education and Sports Sciences atthe University of Baghdad, as well as to identify the relationship between time management and the level of staff functionalperformance. The research population consisted of the staff members who work in the Faculties of Physical Education andSports Sciences for Girls in Al-Jadriya for the academic year 2017-2018. A random sample of 50 staff members from eachfaculty were selected, that is the total number was (100) staff members. The researchers identified the concept of timemanagement and functional performance, after that a questionnaire consisting of (39) statements and (6) parts presented to aspecialized group of experts. The

... Show More
Preview PDF
Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
The Role Of Intellectual Capital In The Performance Of Small And Medium Enterprises Research filed In Small And Medium Enterprises In Baghdad
...Show More Authors

The Research aims to determine role of The Intellectual capital in the performance of small and medium enterprises , to achieve this goal through a researcher from the theoretical literature and studies related to the construction of the scheme shows the hypothetical relationship between the variables, which was adopted by the independent variable intellectual capital, distributed four variable are:( human  capital, structure capital ,customer capital, innovation capital) as well as four variable (the financial perspective, the customer perspective, process perspective ,the learning & growth perspective) The  study were getting to  many results as bellow :the intellectual capital in the small and intermediate p

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Oct 01 2012
Journal Name
Iraqi Journal Of Physics
Synthesis and study the electrical properties of carbon nanotubes- polyvinylchloride composites
...Show More Authors

The aim of this paper, study the effect of carbon nanotubes on the electrical properties of polyvinylchloride. Samples of polyvinylchloride carbon nanotubes composite prepared by using hot press technique. The weight percentages of carbon nanotubes are 0,5,10 and 20wt.%. Results showed that the D.C electrical conductivity increases with increasing of the weight percentages of carbon nanotubes. Also, the D.C electrical conductivity changed with increase temperature for different concentrations of carbon nanotubes. The activation energy of D.C electrical conductivity is decreased with increasing of carbon nanotubes concentration.

View Publication Preview PDF
Publication Date
Wed Jan 01 2020
Journal Name
Plant Archives J.
Evaluation of the performance of triple, single crosses and their inbred in bred lines of maize under two plant population
...Show More Authors

Scopus (2)
Scopus
Publication Date
Thu Oct 01 2020
Journal Name
International Journal Of Interdisciplinary Telecommunications And Networking
Simulated Performance of TFRC, DCCP, SCTP, and UDP Protocols Over Wired Networks
...Show More Authors

Multimedia applications impose different QoS requirements (e.g., bounded end-to-end delay and jitter) and need an enhanced transport layer protocol that should handle packet loss, minimize errors, manage network congestion, and transmit efficiently. Across an IP network, the transport layer protocol provides data transmission and affects the QoS provided to the application on hand. The most common transport layer protocols used by Internet applications are TCP and UDP. There are also advanced transport layer protocols such as DCCP and TFRC. The authors evaluated the performance of UDP, DCCP, SCTP, and TFRC over wired networks for three traffic flows: data transmission, video streaming, and voice over IP. The evaluation criteria were thro

... Show More
View Publication
Crossref (2)
Clarivate Crossref
Publication Date
Wed Jun 10 2009
Journal Name
Iraqi Journal Of Laser
Real Time Quantum Bit Error Rate Performance Test for a Quantum Cryptography System Based on BB84 protocol
...Show More Authors

In this work, the performance of the receiver in a quantum cryptography system based on BB84 protocol is scaled by calculating the Quantum Bit Error Rate (QBER) of the receiver. To apply this performance test, an optical setup was arranged and a circuit was designed and implemented to calculate the QBER. This electronic circuit is used to calculate the number of counts per second generated by the avalanche photodiodes set in the receiver. The calculated counts per second are used to calculate the QBER for the receiver that gives an indication for the performance of the receiver. Minimum QBER, 6%, was obtained with avalanche photodiode excess voltage equals to 2V and laser diode power of 3.16 nW at avalanche photodiode temperature of -10

... Show More
View Publication Preview PDF
Publication Date
Tue Oct 01 2013
Journal Name
Radioelectronics And Communications Systems
BER performance enhancement for secure wireless communication systems based on DCSK-MIMO techniques under Rayleigh fading channel
...Show More Authors

There has been a growing interest in the use of chaotic techniques for enabling secure communication in recent years. This need has been motivated by the emergence of a number of wireless services which require the channel to provide very low bit error rates (BER) along with information security. As more and more information is transacted over wireless media, there has been increasing criminal activity directed against such systems. This paper investigates the feasibility of using chaotic communications over Multiple-Input-Multiple-Output (MIMO) channels. We have studied the performance of differential chaos shift keying (DCSK) with 2×2 Alamouti scheme and 2×1 Alamouti scheme for different chaotic maps over additive white Gaussian noise (

... Show More
View Publication
Scopus (1)
Crossref (1)
Scopus Crossref