Preferred Language
Articles
/
joe-2070
Evaluation of Convective Heat Transfer and Natural Circulation in an Evacuated Tube Solar Collector
...Show More Authors

The evacuated tube solar collector ETC is studied intensively and extensively by experimental and
theoretical works, in order to investigate its performance and enhancement of heat transfer, for Baghdad climate
from April 2011 till the end of March 2012. Experimental work is carried out on a well instrumented collector
consists of 16 evacuated tubes of aspect ratio 38.6 and thermally insulated tank of volume 112L. The relation
between convective heat transfer and natural circulation inside the tube is estimated, collector efficiency, effect of
tube tilt angles, incidence angle modifier, The solar heating system is investigated under different loads pattern (i.e
closed and open flow) to evaluate the heat loss coefficient from tank and tubes, test the collector with various
aspect ratios (32.9 and 27.2). The enhancement in collector performance is studied by using two reflectors (Flat
Plate and Curved Plate) and nanofluid (Water-AL2O3).Theoretical work is run by software (Fluent 6.3), to compute
the velocity and temperature profiles within the tube, for different tube diameters, effect of tube junction angle and
stagnant region in the bottom of the evacuated tube. The experimental results shows that the heat loss coefficient
for tube is W/m2.K and for tank is W/m2.K, the maximum collector temperature is 79°C in winter and
99°C in summer, while that belong to nanofluid collector is 99°C in winter. The best tilted angle (optimum) of
evacuated tube is 41° annually. The collector efficiency increased when using nanofluid of (1, 0.6, 0.3)% volume
fraction as(28.4, 6.8, 0.6)% respectively. The efficiency decreases as (33, 62)% when decreasing tube aspect ratio
from 38.6% to 32.9% and 27.2% respectively. An increase of (16.9 and 7.08)% in collector efficiency is obtained
when using curved and flat plate reflectors respectively. From simulation the best junction angle of the tank is
22.5°. The stagnant region is influenced with changing heat flux, tilted angle and aspect ratio.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Jun 30 2013
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Kinetic Study and Simulation of Oleic Acid Esterification in Different Type of Reactors
...Show More Authors

Esterification reaction is most important reaction in biodiesel production. In this study, oleic acid was used as a suggested feedstock to study and simulate production of biodiesel. Batch esterification of oleic acid was carried out at operating conditions; temperature from 40 to 70 °C, ethanol to oleic acid molar ratio from 1/1 to 6/1, H2SO4 as the catalyst 1 and 5% wt of oleic acid, reaction time up to 180 min. The optimum conditions for the esterification reaction were molar ratio of ethanol/oleic acid 6/1, 5%wt H2SO4 relative to oleic acid, 70 °C, 90 min and conversion of oleic 0.92. The activation energy for the suggested model was 26625 J/mole for forward reaction and 42189 J/mole for equilibrium constant. The obtained results s

... Show More
View Publication Preview PDF
Publication Date
Thu Mar 30 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Antiplatelts Activity of Vitamin E in Relation to Dose and Duration of Therapy
...Show More Authors

           Vitamin E, having the well known antioxidant activity  through scavenging free radicals Ùˆ it occurs in several  isomeric forms , these isomers have relatively different functions . One of these actions is related to its ability to inhibit platelets aggregation and hence thrombosis. The present study included a total number of apparently healthy  62 males . 11of them served as standard group , treated  with 100 mg aspirin /day for more than one month . Another 31 subjects were randomly grouped into 5 groups that received different daily doses of α – tocopherol : 400 IU , 800 IU and 1200 IU for  2-6 months.The remainder ( 20 ) subjects served

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Apr 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Effect of Nano and Mineral NPK in Vegetative Growth Parameter of Pear Saplings
...Show More Authors
Abstract<p>An experiment during the two seasons 2019, 2020. The experiment conducted according to Split Plot Design by two factors; the first was addition Nano NPK with five levels (control, addition 7.5 g.plant<sup>-1</sup>, addition 15 g.plant<sup>-1</sup>, spray 1 g.L<sup>-1</sup>, spray 2 g.L<sup>-1</sup>). The second factor was four levels of Mineral NPK which were (control, 50 g.plant<sup>-1</sup>, 100 g.plant<sup>-1</sup>, 50 g.plant<sup>-1</sup>+1.5 g.L<sup>-1</sup>) respectively. N<sub>3</sub> (spray 1 g.L<sup>-1</sup> ) increased plant height, stem diameter first season, branch number se</p> ... Show More
View Publication
Scopus (1)
Scopus Crossref
Publication Date
Mon Feb 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Problematic of Non Performing Banking Loans in Iraq and the Methods of Treatment
...Show More Authors

The banking system considered as one of the most important intermediate circle between creditor and debtors it is mean the most important funding rings in economic activity, whether finance takes the a consumer or investment form and therefore it is the main base to stimulate economic activity both on the demand side, both consumption and investment and therefore of the main motivating factors for economic growth.

The banking system depends in achieve its goals on the grants and loan recovery, or what is known credit process and according to what the importance referred to the role of the banking system, it is important to ensure the safety and efficiency of the mechanisms of banking device and safety is

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Feb 01 2023
Journal Name
Baghdad Science Journal
Accumulation of Heavy Metals in Agricultural Crops and Ecological Series of Crops Placement
...Show More Authors

The accumulation of toxic elements in vegetables and melons grown in agriculture, Brassica rapa - turnip, Solanum lycopersicum - tomato, Citrullus lanatus - watermelon, Capsicum annuum - bell pepper, Daucus carota - carrots, Cucurbita pepo - pumpkin, Cucumis melo - melon, and also Prunus armeniaca - apricot from fruit trees were analyzed. The excess of maximum allowable concentrations in agricultural crops of the element As by 1.65-1.75, Cd - 1.6-2.3, Cr -1.2-2.35, Cu -1.6-3.3, Ni - 1.16-3.53, Pb - 1.54-3.08, Al - 1.36-3.5, Sb - 2.0-33, Se - 1.1-3.3 times was established. The maximum allowable concentration of mercury in vegetables and melons was equal to 0.02 mg/kg,

... Show More
View Publication Preview PDF
Scopus (7)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Sat Oct 20 2018
Journal Name
Journal Of Economics And Administrative Sciences
Analysis of the causes of poverty and progress strategy to combat in sudan
...Show More Authors

Abstract:

   The problem of poverty is one of the most important development challenges facing developing countries including Sudan for several decades. Although many efforts have been made to reduce poverty, however, its rates are increasing, and public policies adopted by the government in this regard remain elusive in achievinging its main objectives or making any significant progress. The purpose of the present study is to analyse poverty in Sudan by identifying its measurement, causes and the factors that have contributed to the increasing poverty rates over the past two decades. Also this study aims at investigating the interim poverty reduction strategy in Sudan as well as evaluates that strategy throug

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Mar 25 2017
Journal Name
Biomedical And Pharmacology Journal
Detection of Cytomegalovirus and Epstein Barr Virus in Placental Tissues of Aborted Women
...Show More Authors

Introduction The abortions reasons in several circumstances yet are mysterious, nevertheless the bacterial toxicities signify a main reason in abortion, where germs seems to be the utmost elaborate pathogens (Khameneh et.al., 2014) and (Oliver and Overton ,2014). Between numerous germs, Humano

View Publication
Scopus (3)
Scopus
Publication Date
Wed Apr 05 2023
Journal Name
Journal Of Agriculture And Crops
Distribution and Classification of Medicinal Plants in Zakhikhah Area of Al-Anbar Desert
...Show More Authors

This study included the Zakhikhah area in the Al- Anbar desert, which it bounded on the north, east, and west by the Euphrates River and on the south by the Ramadi-Qaim road. Several exploratory field trips were taken to the study area. During this time, a semi-detailed area survey was carried out based on satellite imagery captured by American Land sat-7, topographic maps, and natural vegetation variance. All necessary field tools, including a digital camera and GPS device, were brought to determine the soil type and collect plant samples. All of these visits are planned to cover the entire state of Zakhikhah. All vegetation cover observations, identifying sampling sites and attempting to inventory and collect medicinal plants in t

... Show More
View Publication
Crossref
Publication Date
Tue Oct 22 2024
Journal Name
Hemoglobin
Prevalence and Molecular Characterization of β-Thalassemia in Kirkuk Province of Northern Iraq
...Show More Authors

View Publication
Scopus (2)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Sun Jan 01 2023
Journal Name
International Journal Of Economics And Finance Studies
THE ROLE OF EXTERNAL INDEBTEDNESS OF THE ECONOMIC AND FINANCIAL DEVELOPMENT IN IRAQ
...Show More Authors

The imperative of achieving financial stability has transcended national boundaries, necessitating heightened attention from both researchers and policymakers. Consequently, this article delves into an examination of the impact of government debt and public debt on financial development within the context of Iraq. The study employs monetary policy, interest rate, inflation, and population growth as control variables to prognosticate financial development. Utilizing data extracted from the World Development Indicators (WDI) spanning the period from 1995 to 2022, the study employs the dynamic autoregressive distributed lag (DARDL) approach to scrutinize the associations under investigation. The findings underscore a negative association betwe

... Show More
Preview PDF
Scopus