Preferred Language
Articles
/
joe-733
Experimental Study on Double-Pass Solar Air Heater with and without using Phase Change Material
...Show More Authors

In this paper, an experimental study was conducted to enhance the thermal performance of a double-pass solar air heater (SAH) using phase change material (PCM) for thermal storage at climatic conditions of Baghdad city - Iraq. The double-pass solar air heater integrated with thermal storage system was manufactured and tested to ensure that the air heating reserved after the absence of the sun. The rectangular cavity filled with paraffin wax was used as a latent heat storage and incorporated into the lower channel of solar air heater. Experiments were carried out to evaluate the charging and discharging characteristics of two similar designed solar air collectors with and without using phase change material at a constant air mass flow rate of (0.0375 kg/sec). The parameters that affect the thermal performance of the SAH with and without the PCMs presented by solar radiation, the difference in air temperature, outlet air temperature, instantaneous thermal efficiency, and daily efficiency are evaluated. The experimental results show that when using the PCM, the temperature of the outlet air was enhanced and increased over the ambient temperature by (1.5 - 6.5 C) after sunset for 5 hours period. It was found that the instantaneous thermal efficiency of the heater using thermal storage exceeds 100% after sunset, this is due to a large amount of heat stored in the paraffin wax that has been released during the discharge process. Also, it was found that the daily efficiency of the double pass SAH integrated with and without thermal energy storage unit was (56, 47%) respectively.

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Aug 07 2020
Journal Name
Key Engineering Materials
The Effect of Particle Size Distribution on some Properties of Gypsum
...Show More Authors

Gypsum is one of the important construction materials in Iraq in plastering surfaces and gypsum board , the ability of gypsum to give a comfortable an aesthetic ambiance as a construction material increase the need of gypsum , The particle size , total surface area and particle size distribution were factors affecting plaster properties used for construction properties . In this study gypsum paste was used with different mixing ratios of particle size and studied the physical properties of these types of pastes named (standard consistency ,setting time ,density) and compressive strength . The results showed that the water to gypsum ratio increased with increasing the fineness of the gypsum to (0.75%) and the setting time to the maxi

... Show More
View Publication
Scopus (5)
Crossref (5)
Scopus Crossref
Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Effect of chelating agents on removal of 137Cs from contaminated soil
...Show More Authors

In the present research, the chemical washing method has been selected using three chelating agents: citric acid, acetic acid and Ethylene Diamine Tetraacetic Acid (EDTA) to remove 137Cs from two different contaminated soil samples were classified as fine and coarse grained. The factors that affecting removal efficiency such as type of soil, mixing ratio and molarity have been investigated. The results revealed that no correlation relation was found between removal efficiency and the studied factors. The results also showed that conventional chemical washing method was not effective in removing 137Cs and that there are further studies still need to achieve this objective.

View Publication Preview PDF
Crossref
Publication Date
Sat Mar 01 2008
Journal Name
Iraqi Journal Of Physics
Comparison between Different Data Image Compression Techniques Applied on SAR Images
...Show More Authors

In this paper, image compression technique is presented based on the Zonal transform method. The DCT, Walsh, and Hadamard transform techniques are also implements. These different transforms are applied on SAR images using Different block size. The effects of implementing these different transforms are investigated. The main shortcoming associated with this radar imagery system is the presence of the speckle noise, which affected the compression results.

View Publication Preview PDF
Publication Date
Thu Sep 13 2018
Journal Name
Baghdad Science Journal
Gamma Ray Effect on the Properties of Coumarin C47 Laser Dye
...Show More Authors

The research is concerned about studying the absorption spectrum of the solution coumarin dye C47. The chloroform solvent was used with C47 dye in three different concentrations 10-4, 10-5 and 10-6 M. The laser dye solution was prepared by dissolving the required amount of dye in chloroform alcohol, while studying absorption spectrum before and after irradiation with gamma ray by cobalt-60 source 60Co at exposure time, which are 0, 4, 6 and 18 hours with different absorbed doses 0, 136, 204 and 612 Gy. The results show that red shift in the absorption spectrum was increased by increasing the concentration of laser dye solutions , while the increase of gamma dose led to increase the red shift after irradiation, as the exposure period and irr

... Show More
View Publication Preview PDF
Scopus (3)
Scopus Clarivate Crossref
Publication Date
Sun Sep 03 2017
Journal Name
Baghdad Science Journal
In Vitro Toxicity Evaluation of Silver Nanoparticles on Entamoeba histolytica trophozoite
...Show More Authors

The protozoan parasite Entamoeba histolytica is a causative agent of amoebiasis, where it causes millions of cases of dysentery and liver abscess each year. Metronidazole is a drug of choice against amoebiasis. The drug is a choice because of its efficacy and low cost, but at the same time it causes several adverse side effects; therefore, it is important to find effective medications to treat amoebiasis without any complications or any side effects. The aim of this study is to evaluate the effectiveness of different concentrations (50, 75 and 100 µg/ml) of silver nanoparticle (AgNPs) against trophozoites stages of E. histolytica in vitro. The results showed a significant decrease (p ? 0.05) in numbers of trophozoites stages after treated

... Show More
View Publication Preview PDF
Scopus (8)
Crossref (2)
Scopus Crossref
Publication Date
Fri Mar 01 2019
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Additives on The Performance of Hydrostatic Thrust Bearings
...Show More Authors

 

The paper is concerned with, the behavior of the hydrostatic thrust bearings lubricated with liquid-solid lubricants using Einstein viscosity formula, and taking into account the centrifugal force resulting from high speed.  Also studied is the effect of the bearing dimensions on the pressure, flow rate, load capacity, shear stress, power consumption and stiffness.

The theoretical results show an increase in load capacity by (8.3%) in the presence of solid graphite particles with concentration of (16%) by weight as compared with pure oil, with increasing shear stress.  .

In general the performance of hydrostatic thrust bearings improve for load carrying capacity, volume flow rate,

... Show More
View Publication Preview PDF
Publication Date
Sat Mar 01 2008
Journal Name
Iraqi Journal Of Physics
Effect of Pressure on the Properties of HgBa2Ca2Cu3O8+δ HTSC System
...Show More Authors

High temperature superconductors with a nominal composition HgBa2Ca2Cu3O8+δ
for different values of pressure (0.2,0.3, 0.5, 0.6, 0.9, 1.0 & 1.1)GPa were prepared by
a solid state reaction method. It has been found that the samples were semiconductor
P=0.2GPa.while the behavior of the other samples are superconductor in the rang
(80-300) K. Also the transition temperature Tc=143K is the maximum at P is equal to
0.5GPa. X-ray diffraction showed a tetragonal structure with the decreasing of the
lattice constant c with the increasing of the pressure. Also we found an increasing of
the density with the pressure.

View Publication Preview PDF
Publication Date
Sun Dec 22 2019
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Effects of Hydrochlorothiazide on Tenofovir Disoproxil Fumarate-Induced Nephrotoxicity in Rats
...Show More Authors

Tenofovir disoproxil fumarate, a nucleotide reverse transcriptase inhibitor utilized for the treatment of hepatitis B virus and human immunodeficiency virus infections; and is now one of the most widely used antiretroviral drug. However, tenofovir disoproxil fumarate can induce nephrotoxicity, which may be attributed to the interaction between such drug and the organic anion transporters (hOAT1, and OAT3) with consequent changes in levels of some parameters that may have a role in nephrotoxicity. Thiazide diuretics have high to intermediate potency of inhibition of OAT1s and OAT3; thus, it may possess nephroprotective effects. This study was designed to investigate whether hydrochlorthiazide has nephroprotective effects on tenofovir diso

... Show More
View Publication Preview PDF
Scopus (2)
Crossref (1)
Scopus Crossref
Publication Date
Sun Jun 30 2019
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Adsorption of Chromium Ions on Activated Carbon Produced from Cow Bones
...Show More Authors

Due to the broad range uses of chromium for industrial purposes, besides its carcinogenic effect, an efficient, cost effective removal method should be obtained. In this study, cow bones as a cheap raw material were utilized to produce active carbon (CBAC) by physiochemical activation, which was characterized using: SEM to investigate surface morphology and BET to estimate the specific surface area. The best surface area of CBAC was 595.9 m2/gm which was prepared at 600 C activation temperature and impregnation ratio of 1:1.5. CBAC was used in aqueous chromium ions adsorption. The investigated factors and their ranges are: initial concentration (10-50 mg/L), adsorption time (30-300 min), temperature (20-50

... Show More
View Publication Preview PDF
Crossref (10)
Crossref
Publication Date
Sat Nov 07 2020
Journal Name
Theory And Practice Of Mathematics And Computer Science
Discussion on Bipolar Fuzzy n-fold KU-ideal of KU-algebras
...Show More Authors