Preferred Language
Articles
/
joe-45
The Effect of Fin Design on Thermal Performance of Heat Sink
...Show More Authors

      An experimental and computational study is conducted to analyze the thermal performance of heat sinks and to pick up more profound information in this imperative field in the electronic cooling. One important approach to improve the heat transfer on the air-side of the heat exchanger is to adjust the fin geometry. Experiments are conducted to explore the impact of the changing of diverse operational and geometrical parameters on the heat sink thermal
performance. The working fluid used is air. Operational parameters includes: air Reynolds number (from 23597 to 3848.9) and heat flux (from 3954 to 38357 W/m
2 ). Conformational parameters includes: change the direction of air flow and the area of conduction/convection. Six . parallel plate heat sinks are fabricated and tested in small wind tunnel: flat plate, cross-cut, perforated, perforated cross-cut, zigzag and serpentine. Three-dimensional numerical simulations using commercial available FLUENT 15 software, based on the Navier–Stokes equations standard k-ε applied turbulence model and energy equation, are acquired for forced convection of air in same heat sinks under the same experimental conditions. It is found that the numerical prediction of base temperature is in good agreement with experimental data. Results show that the Reynolds number has a significant effect on the thermal performance of the system. With increasing free stream velocity, the heat transfer coefficient increases and consequently the thermal resistance decreases. Furthermore, it is found that the heat transfer coefficient and thermal resistance are depending on heat flux. From the comparison analysis of various geometries of heat sinks, the perforated-cut heat sink showed the best thermal performance indicated heights Nusselt number and heat transfer coefficient, lowest thermal resistance.

 
 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Dec 03 2017
Journal Name
Baghdad Science Journal
Inhibitory Effect of Bacteriophages Isolated from Sewage Water in the City of Kirkuk on some Types of Human Pathogenic Bacteria
...Show More Authors

Most approaches to combat antibiotic resistant bacteria concentrate on discovering new antibiotics or modifying existing ones. However, one of the most promising alternatives is the use of bacteriophages. This study was focused on the isolation of bacteriophages that are specific to some of commonly human pathogens namely E. coli, Streptococcus pyogenes, Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella spp. and Klebsiella pneumoniae. These bacteriophages were isolated from sewages that were collected from four different locations in Kirkuk City. Apart from S. pyogenes, bacteriophages specific to all tested bacteria were successfully isolated and tested for their effectiveness by spot test. The most effective

... Show More
View Publication Preview PDF
Scopus (4)
Crossref (2)
Scopus Crossref
Publication Date
Wed Jan 01 2025
Journal Name
Baghdad Science Journal
The effect of Bio and Nano Fertilizer on Growth and Yield of Basil Plant and its Content of Active Ingredients
...Show More Authors

A factorial experiment was conducted at the College of Education for Pure Sciences Ibn al Haitham/University of Baghdad for the 2023 growing season to study the effect of the biofertilizer represented by the mycorrhizae vaccine and the NPK Nano fertilizer on some indicators of vegetative and root growth, yield, and volatile oil production of the basil plant, Ocimum basilicum L., the experiment included two factors. The rst factor was mycorrhizae inoculum at 2 levels: 0 (no addition) and an addition of 25 g plant–1, as the seeds were inoculated upon planting. The second factor was spraying the plant’s shoots with NPK Nano fertilizer at four levels (0, 0.5, 1, 1.5) g l–1. The results showed a signicant eect of the treatment of inocula

... Show More
View Publication Preview PDF
Scopus Clarivate Crossref
Publication Date
Tue Mar 27 2018
Journal Name
Mustansiria Dental Journal
The Effect of Modified Carisolv Gel on Surface Roughness of two Different Types of Ceramic Materials Using Light Polarizing Microscope
...Show More Authors

This in vitro study evaluated the influence of chemomechanical caries removal solution on the surface topography of metal-ceramic feldspar porcelain (MAJOR ceramic) and All-ceramic feldspar porcelain (Vita Alpha) using light polarizing microscope. Forty specimens of MAJOR ceramic and forty specimens of Vita Alpha ceramic of (12mm diameter & 3mm height) were prepared .All specimens were polished with silicon polishing burs, cleaned, autoglazed and stored in 37°C before exposure to Carisolv. Thirty specimens of each material randomly exposed to Carisolv gel for 5, 10 and 20 minutes respectively, other ten specimens were not, to act as control group. All specimens were subjected to surface roughness test by profilometer and evalua

... Show More
View Publication
Crossref
Publication Date
Tue Sep 01 2020
Journal Name
Baghdad Science Journal
Improving the Durability of Streak and Thermal Insulation of Petroleum Pipes by Using Polymeric Based Paint System: Polymer Matrix Composites have several and wide applications
...Show More Authors

This research deals with increasing the hardening and insulating the petroleum pipes against the conditions and erosion of different environments. So, basic material of epoxy has been mixed with Ceramic Nano Zirconia reinforcement material 35 nm with the percentages  (0,1,2,3,4,5) %, whereas the paint basis of broken petroleum pipes was used  to paint on it, then it was cut into dimensions (2 cm. × 2 cm.) and 0.3cm high. After the paint and percentages are completed, the samples were immersed into the paint. Then, the micro-hardness was checked according to Vickers method and thermal inspection of paint, which contained (Thermal conduction, thermal flux and Thermal diffusivity), the density of the painted samples was calculate

... Show More
View Publication Preview PDF
Scopus (13)
Crossref (11)
Scopus Clarivate Crossref
Publication Date
Mon May 01 2017
Journal Name
Journal Of The Mechanical Behavior Of Biomedical Materials
Bioactivity, cytocompatibility and thermal properties of experimental Bioglass-reinforced composites as potential root-canal filling materials
...Show More Authors

To evaluate the bioactivity and the cytocompatibility of experimental Bioglass-reinforced polyethylene-based root-canal filling materials. The thermal properties of the experimental materials were also evaluated using differential scanning calorimetry, while their radiopacity was assessed using a grey-scale value (GSV) aluminium step wedge and a phosphor plate digital system. Bioglass 45S5 (BAG), polyethylene and Strontium oxide (SrO) were used to create tailored composite fibres. The filler distribution within the composites was assessed using SEM, while their bioactivity was evaluated through infrared spectroscopy (FTIR) after storage in simulated body fluid (SBF). The radiopacity of the composite fibres and their thermal properties were

... Show More
View Publication Preview PDF
Crossref (30)
Crossref
Publication Date
Mon Sep 10 2018
Journal Name
Iraqi Journal Of Physics
Thermal conductivity and diffusion coefficient of polymer blend 80%EP/20%UPE reinforced with sand particles
...Show More Authors

New polymer blend with enhanced properties was prepared from (80 %) epoxy resin (Ep), (20%) unsaturated polyester resin (UPE) as a matrix material. The as-obtained polymer blend was further reinforced by adding Sand particles of particle size (53 μm) with various weight fraction (5, 10, 15, 20 %). Thermal conductivity and sorption measurements are performed in order to determine diffusion coefficient in different chemical solutions (NaOH, HCl) with concentration (0.3N) after immersion for specific period of time (30 days). The obtained results demonstrate that the addition of sand powder to (80%EP/20%UPE) blend leads to an increase of thermal conductivity, with an optimum/minimum diffusion coefficient in (HCl)/(NaOH), respectively.

View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Thu Mar 01 2018
Journal Name
مجلة الباحث في العلوم الإنسانية و الإجتماعية
The Rate of Performance of Scientific Committees in the University of Baghdad in Accordance to the Department’s Heads’ Viewpoint
...Show More Authors

The research aims at recognition of The rate of performing tasks done by the scientific committees in the scientific departments in the University of Baghdad, within the evaluative perspective of the departments’ Heads. To find any statistically significant differences in the responses of the research sample to the rates performance of the scientific committees in scientific departments in the University of Baghdad, within the evaluative perspective of the departments’ Heads, according to the two variables of the social gender; male and females, and field of specialization of Scientific and Humanities. The research sample consisted if (107) heads of the scientific department in the University of Baghdad. The researchers designed a

... Show More
View Publication
Publication Date
Tue Dec 15 2020
Journal Name
Al-academy
Acculturation and its Evolutionary Tendency in the Design of the Prayer Space Elements / Niche – A model: آلاء طالب كريم
...Show More Authors

The peculiarity of worship spaces in the Islamic architecture is evident by its symbolic connotations with doctrinal connections, thus the niche has a major status in that symbolic connotation, which transformed due to the cultural interaction from a rock on the wall directed towards Mecca into an element of integrated structural entity with performative and aesthetic characteristics. The spread of the Islamic religion contributed to subjecting it to a design acculturation process, thus the problem of the research was raised by the following question: has the evolutionary tendency of acculturation been able to effect a major transformation in the niche design? The research aims at identifying the design acculturation and its translation

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Feb 06 2020
Journal Name
Political Sciences Journal
Self-immuniztion: integration of Russian strategic performance a study in the geopolitical orientation circles "of the stage of president putin"n
...Show More Authors

In the period after the collapse of the Soviet Union in 1991, the Federal Republic of Russia witnessed a setback in the overall strategic performance of the country, as it went through a stage of performance flop between the orientation towards Europe in the era of President Boris Yelsen (1991-1999), or the change of direction towards Eurasia, as the Russian Federation managed After President Vladimir Putin assumed power in 2000, from rebuilding the same state and preserving national unity and social cohesion, as well as building a phased military doctrine that made clear moves in Russian strategic thought and future directions towards regions of eternal importance in Russian strategic perception Lack of a set of motivations based on it:

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Oct 03 2018
Journal Name
Opcion
Evaluating the financial performance according to the traditional and modern financial indicators
...Show More Authors

The research aims to develop the general performance and improve the level of activity of private insurance companies in line with the current progress of the country. Besides, Evaluating financial performance to diagnose weaknesses and strengths in sample research companies and then developing appropriate solutions. The deviation in the financial performance of the research sample was revealed by measuring the various accounts of the company. The research sample included five companies in the private insurance sector listed in the Iraqi Stock Exchange Market, which represent the private insurance sector. The research concluded that the added economic value is a broad concept that goes beyond the traditional performance evaluation process a

... Show More