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
Thu Jan 01 2015
Journal Name
Chemical And Process Engineering Research
SYNTHESIS, Spectroscopic Characterization and Evaluation (Antibacterial & (GOT, G pT) Enzyme )Activity of Mixed Ligand Complexes of M(II) with Amino Acid (L-Asparagine) and Schiff Bases Derived from (Sulfamethoxazo Drug with 2,4Dimethoxybenzaldehyde)
...Show More Authors

The research includes the synthesis and identification of the mixed ligands complexes of M 2 Ions in general composition ,[M(Leu) 2 (SMX)] Where L leucine (C 6 H 13 NO 2 )symbolized (LeuH) as a primary ligand and Sulfamethoxazole C 10 H 11 N 3 O 3 S) symbolized (SMX)) as a secondary ligand . The ligands and the metal chlorides were brought in to reaction at room temperature in(v/v) ethanol /water as solvent containing NaOH. The reaction required the following [(metal: 2(Na Leu --): (SMX )] molar ratios with M(II) ions, Were M (  Mn ( II),Co (II),Ni(II),Cu( II),Zn (II),Cd(II)and Hg( The UV Vis and magnetic moment data revealed an octahedral geometry around M(II), The conductivity data show a non electrolytic nature of the complexes . The

... Show More
Preview PDF
Publication Date
Sat Dec 01 2018
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Measuring the impact of the financial value of human resources on investor decisions: (An Empirical Study)
...Show More Authors

The aim of the research is to clarify the measurement of the impact regarding financial value of human resources on investors' decisions by considering that the human element is one of the assets of the company. Therefore, a set of criteria must be available to determine the applicability of these standards in the human resource because it has an effective role in the success for the company. Is to measure the value of human resources in a financial format according to the first two methods depends on the value and the second depends on the cost.

In order to achieve the objectives of the study, a questionnaire was designed to survey the views of a number of employees of the General Company for Leather Industries in order to arriv

... Show More
View Publication
Crossref
Publication Date
Wed Aug 13 2025
Journal Name
Journal Of Baghdad College Of Dentistry
An Assessment of the Efficacy of Sinus Balloon Technique on Transcrestal Maxillary Sinus Floor Elevation Surgery
...Show More Authors

Background: A minimally invasive antral membrane balloon elevation (MIAMBE) has been introduced to overcome the invasiveness of modified Caldwell-Luc (lateral approach) and the drawbacks of the osteotome (summers' technique) in maxillary sinus floor elevation surgery. Materials and methods: A total of 13 adult Iraqi patients aged 28-55 years, 4 males and 9 females underwent sinus floor elevation surgery via crestal approach by using sinus balloon technique. A panoramic radiograph and (Cone beam computed tomography (CBCT)/or medical CT scan) were obtained before and after surgery. Postoperative gained bone was assessed and the patient reactions including pain, nasal bleeding, and ecchymosis were recorded. The whole follow up period was 1yea

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Fri Dec 22 2023
Journal Name
Eastern-european Journal Of Enterprise Technologies
Evaluating the impact of structure parameters on the acoustic performance of an exhaust muffler with shells
...Show More Authors

Recently, environmental noise has arisen from various sources, such as those from exhaust mufflers of combustion engines found in cars, trucks, or power generators, which produce significant noise during their operation. Controlling the radiated noise from these mufflers is a major factor in improving acoustic comfort and minimizing the impact on the surrounding communities. Numerous research has been presented for this reason by modification of the internal structure of the exhaust muffler. The main objective of this work is to reduce the noise level emitted from exhaust mufflers. This can be achieved by adjusting structure parameters to attenuate the surrounding environment's radiated noise. Analysis of pressure-wave propagation h

... Show More
View Publication
Scopus (2)
Crossref (1)
Scopus Crossref
Publication Date
Sun Jan 01 2023
Journal Name
8th Engineering And 2nd International Conference For College Of Engineering – University Of Baghdad: Coec8-2021 Proceedings
Effect of permeation grouting with nano-materials on shear strength of sandy soil: An experimental study
...Show More Authors

View Publication
Crossref (4)
Crossref
Publication Date
Tue Jan 01 2019
Journal Name
Desalination And Water Treatment
Synthesis of chitosan-iron keplerate composite as an adsorbent for removal of toxic ions from water
...Show More Authors

View Publication
Scopus (3)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Sat Mar 26 2022
Journal Name
Nasaq Journal
An analytical study of the science textbook of the intermediate 1st grade according to life skills
...Show More Authors

The aim of this study is to develop the science textbook for the 1st intermediate grade by analyzing it according to life skills. Its core areas were mental skills, environmental skills, and health skills. The analysis tool was used after verifying its validity and stability in analyzing the science textbook for the 1st intermediate grade, and the results of the study resulted in the inclusion of mental skills on a high percentage of repetitions, while we find that this percentage is low in the inclusion of environmental and health skills. The study recommended the importance of achieving balance and justice in including skills in the science textbook for the 1st intermediate grade, by emphasizing the environmental and health skills by incr

... Show More
Publication Date
Wed May 31 2017
Journal Name
Journal Of Engineering
Construction Policies on Campus An Analytical Study of the Policy of Construction Planning on Kufa Campus
...Show More Authors

     University Campuses, as any lively physical entity, is subject to continuous variation due to . growth, development and change. This reality covers the existing or futuristic additives or  additions, consecutively these changes may have a strong sensation of disorientation as a result of formatic changes in buildings, or in movement paths. And it epitomized the research problem to "the need for knowledge to clarify the impact of intellectual and executive policy in achieving coherence, functional and space organization of the elements of the university urban environment and in the stages of future growth and change,"  the search targeted "to highlight the study of constraction politics on campus Bmqomad

... Show More
View Publication Preview PDF
Publication Date
Thu Nov 02 2023
Journal Name
Journal Of Engineering
An Overview of How the Petrophysical Properties of Rock Influenced After Being Exposed to Cryogenic Fluid
...Show More Authors

Exposure to cryogenic liquids can significantly impact the petrophysical properties of rock, affecting its density, porosity, permeability, and elastic properties. These effects can have important implications for various applications, including oil and gas production and carbon sequestration. Cryogenic liquid fracturing is a promising alternative to traditional hydraulic fracturing for exploiting unconventional oil and gas resources and geothermal energy. This technology offers several advantages over traditional hydraulic fracturing, including reduced water consumption, reduced formation damage, and a reduced risk of flow-back fluid contamination. In this study, an updated review of recent studies demonstrates how the

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Thu Feb 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Post-evaluation of the strategic projects of the Directorate of Public Municipalities - Case study for the period (2004-2015
...Show More Authors

The research aims at conducting a follow-up evaluation of a number of strategic projects implemented by the Directorate of Public Municipalities, one of the Ministry of Construction, Housing and Municipalities and Public Works. The sample included (35) varied strategic projects implemented in most Iraqi governorates. Buildings, municipal buildings, minarets, massacres, multi-story parking, paving and rehabilitation of streets and residential neighborhoods. The difference between the actual and planned times and costs of these projects was then measured and analyzed. These projects were used as a tool for collecting data and information. The questionnaire included four axes, each representing one of the parties to the project, whi

... Show More
View Publication Preview PDF
Crossref