Preferred Language
Articles
/
BIbl0YYBIXToZYALYbWz
Natural Convection Effect on Solidification Enhancement in a Multi-Tube Latent Heat Storage System: Effect of Tubes’ Arrangement
...Show More Authors

The solidification process in a multi-tube latent heat energy system is affected by the natural convection and the arrangement of heat exchanger tubes, which changes the buoyancy effect as well. In the current work, the effect of the arrangement of the tubes in a multi-tube heat exchanger was examined during the solidification process with the focus on the natural convection effects inside the phase change material (PCM). The behavior of the system was numerically analyzed using liquid fraction and energy released, as well as temperature, velocity and streamline profiles for different studied cases. The arrangement of the tubes, considering seven pipes in the symmetrical condition, are assumed at different positions in the system, including uniform distribution of the tubes as well as non-uniform distribution, i.e., tubes concentrated at the bottom, middle and the top of the PCM shell. The model was first validated compared with previous experimental work from the literature. The results show that the heat rate removal from the PCM after 16 h was 52.89 W (max) and 14.85 W (min) for the cases of uniform tube distribution and tubes concentrated at the bottom, respectively, for the proposed dimensions of the heat exchanger. The heat rate removal of the system with uniform tube distribution increases when the distance between the tubes and top of the shell reduces, and increased equal to 68.75 W due to natural convection effect. The heat release rate also reduces by increasing the temperature the tubes. The heat removal rate increases by 7.5%, and 23.7% when the temperature increases from 10 °C to 15 °C and 20 °C, respectively. This paper reveals that specific consideration to the arrangement of the tubes should be made to enhance the heat recovery process attending natural convection effects in phase change heat storage systems.

Scopus Clarivate Crossref
View Publication
Publication Date
Mon Dec 30 2013
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
A Study of Water Flux through Forward Osmosis Membrane Using Brine\Fresh Water System
...Show More Authors

The present work aims to improve the flux of forward osmosis with the use of Thin Film Composite membrane by reducing the effect of polarization on draw solution (brine solution) side.This study was conducted in two parts. The first is under the effect of polarization in which the flux and the water permeability coefficient (A) were calculated. In the second part of the study the experiments were repeated using a circulating pump at various speeds to make turbulence and reduce the effect of polarization on the brine solution side.
A model capable of predicting water permeability coefficient has been derived, and this is given by the following equations:
Z=Z+C.R.T/9.8(d2/D2+1) [Exp. [-9.8(d

... Show More
View Publication Preview PDF
Publication Date
Mon Nov 19 2018
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Effective of incentive system on development of Research creativity for professors of university: Analytical study at private collage in Baghdad
...Show More Authors

This research aims at studying and analyzing the creative research thinking of the educational staffs in private universities and colleges, and also the role of incentives, in its materialistic and moral sides in the development of such thinking and the pack of restraints which cause decline in interest level of the scientificresearch, and its weak role in the development of universities in Iraq, despite the interest of the Ministry of Higher Education and Scientific Research in Iraq in scientific research as part ofits academic and humanitarian targets.Based on study and analysis, and the using if some of statistical methods such as the Alpha Chronobaghcoefficient and the (T. Test)(F. Test),the research reached a number of conclusions.

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jul 12 2023
Journal Name
Energies
Finite Time Disturbance Observer Based on Air Conditioning System Control Scheme
...Show More Authors

A novel robust finite time disturbance observer (RFTDO) based on an independent output-finite time composite control (FTCC) scheme is proposed for an air conditioning-system temperature and humidity regulation. The variable air volume (VAV) of the system is represented by two first-order mathematical models for the temperature and humidity dynamics. In the temperature loop dynamics, a RFTDO temperature (RFTDO-T) and an FTCC temperature (FTCC-T) are designed to estimate and reject the lumped disturbances of the temperature subsystem. In the humidity loop, a robust output of the FTCC humidity (FTCC-H) and RFTDO humidity (RFTDO-H) are also designed to estimate and reject the lumped disturbances of the humidity subsystem. Based on Lyapunov theo

... Show More
View Publication
Scopus (7)
Crossref (6)
Scopus Clarivate Crossref
Publication Date
Tue Dec 01 2020
Journal Name
Journal Of Engineering
National Grid Connected 3-Phase Inverter based on Photovoltaic Solar System
...Show More Authors

In this paper, a national grid-connected photovoltaic (PV) system is proposed. It extracts the maximum power point (MPP) using three-incremental-steps perturb and observe (TISP&O) maximum power point tracking (MPPT) method. It improves the classic P&O by using three incremental duty ratio (ΔD) instead of a single one in the conventional P and O MPPT method. Therefore, the system's performance is improved to a higher speed and less power fluctuation around the MPP. The Boost converter controls the MPPT and then is connected to a three-phase voltage source inverter (VSI). This type of inverter needs a high and constant input voltage. A second-order low pass (LC) filter is connected to the output of VSI to reduce t

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Mon Oct 31 2022
Journal Name
Ingénierie Des Systèmes D Information
Iraqi Paradigm E-Voting System Based on Hyperledger Fabric Blockchain Platform
...Show More Authors

Voting is one of the most fundamental components of a democratic society. In 2021 Iraq held the Council of Representatives (CoR) elections in 83 electoral constituencies in 19 governorates. Nonetheless, several significant issues arose during this election, including the problem of logistics distribution, the excessively long period of ballot counting, voters can't know if their votes were counted or if their ballots were tampered with, and the inconsistent regulation of vote counting. Blockchain technology, which was just invented, may offer a solution to these problems. This paper introduces an electronic voting system for the Iraq Council of Representatives elections that is based on a prototype of the permission hyperledger fabr

... Show More
View Publication
Scopus (6)
Crossref (1)
Scopus Crossref
Publication Date
Sat May 24 2025
Journal Name
Iraqi Journal For Computer Science And Mathematics
Intrusion Detection System for IoT Based on Modified Random Forest Algorithm
...Show More Authors

An intrusion detection system (IDS) is key to having a comprehensive cybersecurity solution against any attack, and artificial intelligence techniques have been combined with all the features of the IoT to improve security. In response to this, in this research, an IDS technique driven by a modified random forest algorithm has been formulated to improve the system for IoT. To this end, the target is made as one-hot encoding, bootstrapping with less redundancy, adding a hybrid features selection method into the random forest algorithm, and modifying the ranking stage in the random forest algorithm. Furthermore, three datasets have been used in this research, IoTID20, UNSW-NB15, and IoT-23. The results are compared with the three datasets men

... Show More
View Publication Preview PDF
Scopus (4)
Crossref (2)
Scopus Crossref
Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
Theoretical Study of the Effect of Permeability Tensor upon Drainage of Soils
...Show More Authors

the influence of permeability tensor upon drainage of anisotropic soils under ponded water and steady recharge (rainfall) is theoretically investigated. Tensorial permeability has led to the formulation of mixed type partial differential equations. Since there is no analytical solution to this problem, the formulation is therefore solved numerically by the method of finite elements. The finite element formulation is implemented into a computer model which can be applied to any problem of seepage under steady state
conditions. Two different example problems representing two different flow conditions under full anisotropy have been studied. Results of the model for the isotropic case were checked against exact mathematical solutions de

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Sep 08 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The effect of financial leverage on the market value of the shares of Iraqi commercial banks: An applied research in the Bank of Baghdad for the period (2010-2019)
...Show More Authors

The aim of the research is to know the effect of financial leverage on the market value of the stock by applying it to a sample of private Iraqi commercial banks listed in the Iraqi Stock Exchange for the period (2010-2019) and to show the extent of that effect, based on the bank’s annual reports for the mentioned period through the use of financial leverage ratios represented b (Equity multiplier, cash balance ratio), its discussion, analysis, description, inferential description, and testing of research hypotheses,

A set of conclusions has been reached, the most important of which are: The research sample banks depend in their financial structures on borrowed funds in a greater proportion than their r

... Show More
View Publication Preview PDF
Publication Date
Mon Jan 01 2024
Journal Name
Journal Of Research In Pharmacy
Phytochemical constituents of ethyl acetate fraction of both roots and leaves of Sansevieria triafasciata cultivated in Iraq and assessment of its anti-proliferative effect on breast cancer cell line
...Show More Authors

View Publication
Scopus Clarivate Crossref
Publication Date
Thu Oct 01 2015
Journal Name
Engineering And Technology Journal
Genetic Based Optimization Models for Enhancing Multi- Document Text Summarization
...Show More Authors

View Publication
Crossref