Preferred Language
Articles
/
_obh0YYBIXToZYAL6rQE
Melting Enhancement in a Triple-Tube Latent Heat Storage System with Sloped Fins
...Show More Authors

Due to the potential cost saving and minimal temperature stratification, the energy storage based on phase-change materials (PCMs) can be a reliable approach for decoupling energy demand from immediate supply availability. However, due to their high heat resistance, these materials necessitate the introduction of enhancing additives, such as expanded surfaces and fins, to enable their deployment in more widespread thermal and energy storage applications. This study reports on how circular fins with staggered distribution and variable orientations can be employed for addressing the low thermal response rates in a PCM (Paraffin RT-35) triple-tube heat exchanger consisting of two heat-transfer fluids flow in opposites directions through the inner and the outer tubes. Various configurations, dimensions, and orientations of the circular fins at different flow conditions of the heat-transfer fluid were numerically examined and optimized using an experimentally validated computational fluid-dynamic model. The results show that the melting rate, compared with the base case of finless, can be improved by 88% and the heat charging rate by 34%, when the fin orientation is downward–upward along the left side and the right side of the PCM shell. The results also show that there is a benefit if longer fins with smaller thicknesses are adopted in the vertical direction of the storage unit. This benefit helps natural convection to play a greater role, resulting in higher melting rates. Changing the fins’ dimensions from (thickness × length) 2 × 7.071 mm2 to 0.55 × 25.76 mm2 decreases the melting time by 22% and increases the heat charging rate by 9.6%. This study has also confirmed the importance of selecting the suitable values of Reynolds numbers and the inlet temperatures of the heat-transfer fluid for optimizing the melting enhancement potential of circular fins with downward–upward fin orientations.

Scopus Clarivate Crossref
View Publication
Publication Date
Tue Jun 20 2023
Journal Name
Baghdad Science Journal
Insulin Like Growth Factor Binding Protein 7 as a Novel Diagnostic Marker in Sera of Iraqi Patients with Acromegaly
...Show More Authors

The purpose of this study was to measure serum levels of insulin-like growth factor-binding protein (IGFBP7), Insulin-like Growth Factor 1 (IGF-1), Growth Hormone (GH), Interleukin 6 (IL-6) and insulin in acromegaly patients and healthy controls. The acromegaly group had 60 patients, while the population group had 30 people who had never had acromegaly before. The concentration of IGFBP7, IGF-1, GH, IL-6, and insulin were determined. The results of the present study indicate that IGFBP7 level in the acromegaly group was significantly lower (1.690.07 ng/mL vs. 2.740.12 ng/mL, respectively, p = 0.001). IGF-1, GH, IL-6, and insulin concentrations were also significantly higher in acromegaly patients. The diagnostic accuracy (2.194) was exce

... Show More
View Publication Preview PDF
Scopus (7)
Crossref (3)
Scopus Crossref
Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
Obstacles to Administrative Creativity of Female Leaders in Secondary Schools (Curriculum System) in the Northern Border Region in Saudia Arabia
...Show More Authors

The study aimed to reveal the obstacles of administrative creativity among the leaders of secondary schools (the curriculum system) in the northern border region, which relate to the obstacles (organizational, motivational, and psychological). In addition, to identify the most important statistical differences between the responses of the members of the study sample, which attribute to the variables (educational qualification, year’s Administrative expertise). To achieve the goal of the study, the researcher used the descriptive analytical approach, and to verify the validity of the tool, it has presented to several referees and faculty members in the educational field. The validity of the internal consistency was also calculated for t

... Show More
View Publication Preview PDF
Publication Date
Wed Dec 14 2016
Journal Name
Journal Of Baghdad College Of Dentistry
Cell Surface Expression of 70 KDa Heat Shock Proteins and P21 in Normal Oral Mucosa, Oral Epithelial Dysplasia and Squamous Cell Carcinoma (An Immunohistochemical Study)
...Show More Authors

Background: Oral SCC is a complex malignancy where environmental factors, viral infections and genetic alterations most likely interact, and thus give rise to the malignant condition. The HSP70 play a direct role in apoptosis inhibition by aligning the improved integrity of a cell’s proteins with the improved chances of that particular cell’s survival.P21 gene produces p21 protein which is a potent cyclin-dependent kinase inhibitor that plays a significant role in carcinogenesis. The aims of the study were to evaluate and compare the immun-histochemical expression of the HSP70 and cell cycle protein p21in NOM, OED, and OSCC. Correlate both marker expressions with each other. Materials and methods: Forty six formalin-fixed, par

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Thu Jul 01 2021
Journal Name
Journal Of Engineering
Proposed Security Framework for Mobile Data Management System
...Show More Authors

Portable devices such as smartphones, tablet PCs, and PDAs are a useful combination of hardware and software turned toward the mobile workers. While they present the ability to review documents, communicate via electronic mail,  appointments management, meetings, etc. They usually lack a variety of essential security features. To address the security concerns of sensitive data, many individuals and organizations, knowing the associated threats mitigate them through improving authentication of users, encryption of content, protection from malware, firewalls,  intrusion prevention, etc. However, no standards have been developed yet to determine whether such mobile data management systems adequately provide the fu

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Fri Sep 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
The Quality of Audit Work Under Expert System
...Show More Authors

The research aims to extrapolate the repercussions of the use of expert systems in the work of the external auditor on the quality of audit, as the research problem was that despite the use of these techniques in audit work, there is a problem related to the efficiency and effectiveness of these technological systems used in audit work, the feasibility of their use and the extent of their impact: The quality of the audit process.

The researchers adopted the questionnaire as a tool for collecting study data from a community composed of auditors in auditing offices and companies in Iraq, and the auditors of the Iraqi Federal Financial Supervision Bureau. The number of recovered and valid qu

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Fri Mar 31 2017
Journal Name
Al-khwarizmi Engineering Journal
Emergency Fuel Rationing system using RFID Smart Cards
...Show More Authors

Rationing is a commonly used solution for shortages of resources and goods that are vital for the citizens of a country. This paper identifies some common approaches and policies used in rationing as well asrisks that associated to suggesta system for rationing fuelwhichcan work efficiently. Subsequently, addressing all possible security risks and their solutions. The system should theoretically be applicable in emergency situations, requiring less than three months to implement at a low cost and minimal changes to infrastructure.

View Publication Preview PDF
Crossref
Publication Date
Fri Mar 31 2017
Journal Name
Journal Of Engineering
Hydraulic Analysis of the Samarra-Al Tharthar System
...Show More Authors

Low incoming discharge upstream of Samarra-Al Tharthar System leads to sediment accumulation and forming islands, especially an island upstream of Al Tharthar Regulator. This island and the sedimentation threaten the stability of the structure and reduce the efficiency of the system. This study aims to hydraulically identify the sedimentation problem mentioned above, to find solutions of how to control the sediment problems, and to develop the capacity of
the system for 500 years return period flood of 15060 m3/s. Surface Water Modeling System (SMS10.1) with two dimensional depth average models (RMA-2) software were used to simulate and analyze the system. The results of analysis showed that the maximum permissible discharge through t

... Show More
View Publication Preview PDF
Publication Date
Fri Mar 01 2019
Journal Name
Al-khwarizmi Engineering Journal
COMPUTER-BASED ECG SIGNAL ANALYSIS AND MONITORING SYSTEM
...Show More Authors

This paper deals with the design and implementation of an ECG system. The proposed system gives a new concept of ECG signal manipulation, storing, and editing. It consists mainly of hardware circuits and the related software. The hardware includes the circuits of ECG signals capturing, and system interfaces. The software is written using Visual Basic languages, to perform the task of identification of the ECG signal. The main advantage of the system is to provide a reported ECG recording on a personal computer, so that it can be stored and processed at any time as required. This system was tested for different ECG signals, some of them are abnormal and the other is normal, and the results show that the system has a good quality of diagno

... Show More
View Publication Preview PDF
Publication Date
Sun Jun 12 2011
Journal Name
Baghdad Science Journal
Comparison between Direct and Coherent Optical Communication System
...Show More Authors

The work in this paper focuses on the system quality of direct and coherent communication system for two computers. A system quality is represented by Signal to Noise ratio (SNR) and Bit Error Rate (BER). First part of the work includes implementation of direct optical fiber communication system and measure the system quality .The second part of the work include implementation both the( homodyne and heterodyne)coherent optical fiber communication system and measure the system quality . Laser diode 1310 nm wavelength with its drive circuit used in the transmitter circuit . A single mode of 62.11 km optical fiber is selected as transmission medium . A PIN photo detector is used in the receiver circuit. The optical D-coupler was u

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Oct 01 2020
Journal Name
Journal Of Engineering
Ergodic Capacity for Evaluation of Mobile System Performance
...Show More Authors

In this research the performance of 5G mobile system is evaluated through the Ergodic capacity metric. Today, in an­­y wireless communication system, many parameters have a significant role on system performance. Three main parameters are of concern here; the source power, number of antennas, and transmitter-receiver distance. User equipment’s (UEs) with equal and non-equal powers are used to evaluate the system performance in addition to using different antenna techniques to demonstrate the differences between SISO, MIMO, and massive MIMO. Using two mobile stations (MS) with different distances from the base station (BS), resulted in showing how using massive MIMO system will improve the performance than the standar

... Show More
View Publication Preview PDF
Crossref (7)
Crossref