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alkej-110
Experimental Investigation of the Effect of Curvature Ratio on Heat Transfer in Double Pipe Helical Heat Exchanger
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Different parameters of double pipe helical coil were investigation experimentally. Four coils were used; three with a curvature ratio (0.037, 0.031, and 0.028) and 11mm diameter of the inner tube while the fourth with 0.033 curvature ratio and 13 mm diameter of the inner tube. The hot water flow in the inner tube whereas the cold water flows in the annulus. The inlet temperatures of hot and cold water are 50 0C and 18 0C respectively. The inner mass flow rate ranges from 0.0167 to 0.0583 kg/s. The results show the Nusselt number increase with increase curvature ratio. The Nusselt number of the coil with 0.037 curvature ratio increases by approximately 12.3 % as compare with 0.028 curvature ratio. The results also reveal that the Nusselt number of the coil with curvature ratio 0.033 increases by approximately 11.6 % as compare with 0.028 curvature ratio for 400 mm coil diameter.

 

 

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Publication Date
Fri Sep 30 2011
Journal Name
Al-khwarizmi Engineering Journal
Studying the Effect of Addition Particles of Alumina (Al2O3) and Zirconia (ZrO2), on Some Mechanical Properties for Matrix Composites (Al-Si-Mg) Alloy
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This study is concerned with the effect of adding two kinds of ceramic materials on the mechanical properties of (Al-7%Si- 0.3%Mg) alloy, which are zirconia with particle size (20μm > P.S ≥ 0.1μm) and alumina with particle size (20μm > P.S ≥ 0.1μm) and adding them to the alloy with weight ratios (0.2, 0.4, 0.6, 0.8 and 1%). Stirring casting method has been used to make composite material by using vortex technique which is used to pull the particles to inside the melted metals and distributed them homogenously.

After that solution treatment was done to the samples at (520ºC) and artificial ageing at (170ºC) in different times, it has been noticed that the values of hardness is increased with the aging time of the o

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Publication Date
Sat Dec 01 2018
Journal Name
Al-khwarizmi Engineering Journal
Effect Ti/AlTiN Multilayer Coating on the Crater Wear Process of Cutting Tool and Tribological Properties
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Tool wear is a major problem in machining operations because the resulting material loss gradually changes of the machine tool. There many factors may leads to material loss like; friction, corrosion, and also it’s happened by rubbing during machining processes between the work piece and the tool. Dimensional accuracy of the work piece, and also the surface finish will be reducing by tool wear. It can also increase cutting force. In this study, we focused on the effect of the coating process on crater wear problems. Crater wear is caused by the flow between the chip and the rake face of the tool, whereas flank wear is caused by the contact between the tool and the work piece. In reducing crater wear, aluminum titanium nitride (AlTiN) u

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Publication Date
Tue May 16 2023
Journal Name
Journal Of Engineering
Investigation of Backfill Compaction Effect on Buried Concrete Pipes
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The present study deals with the experimental investigation of buried concrete pipes. Concrete pipes are buried in loose and dense conditions of gravelly sand soil and subjected to different surface loadings to study the effects of the backfill compaction on the pipe. The experimental investigation was accomplished using full-scale precast unreinforced concrete pipes with 300 mm internal diameter tested in a laboratory soil box test facility set up for this study. Two loading platforms are used namely, uniform loading platform and patch loading platform. The wheel load was simulated through patch loading platform which have dimensions of 254 mm *508 mm, which is used by AASHTO to model the wheel load of a HS20 truck. The pipe-soil system

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Publication Date
Sat Dec 30 2023
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of Green Training and Development on Sustainable Performance: An Analytical Research in the Ministry of Environment
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The current study aims to test the impact of green training and development on sustainable performance and explore its effects within and outside the Iraqi Ministry of Environment. The main research problem revolves around the question of the extent of implementing green training and development and sustainable performance in the ministry (What is the nature of the relationship between green training and development and sustainable performance in the ministry?). To clarify the relationship between the research variables, two main hypotheses were formulated along with sub-hypotheses. The study also aims to assess the level of the ministry's interest in the research variables and provide key recommendations to enhance sustainable performan

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Publication Date
Mon Dec 18 2017
Journal Name
Al-khwarizmi Engineering Journal
Effect of Magnesium Addition on Corrosion Resistance of Aluminum -17%Silicon Alloy
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The electrochemical behavior of Al-17%Si alloy is investigated in 3.5wt% NaCl solution. Many alloys with addition of the different wt% magnesium metal of  1wt%, 2%, 3wt% ,4.5wt% ,and 9wt% were prepared by gravity die casting . The microstructures of prepared alloys were examined by optical and SEM microscopes. Corrosion behavior was investigated by using potentiostat instrument under static potentials test and corrosion current was recorded to determine corrosion resistance of all prepared samples. It was found that the addition of Mg metal improves the corrosion resistance of Al-17%Si alloy in 3.5%NaCl solution. The alloy containing 1%Mg shows less corrosion rate than the others while the alloys containing 4.5%Mg, 9%Mg content have

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Publication Date
Tue Sep 04 2018
Journal Name
Al-khwarizmi Engineering Journal
Effect of Carburization Parameters on Hardness of Carburized Steel Using MOORA Approach
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In this research, (MOORA) approach based– Taguchi design was used to convert the multi-performance problem into a single-performance problem for nine experiments which built (Taguchi (L9) orthogonal array) for carburization operation. The main variables that had a great effect on carburizing operation are carburization temperature (oC), carburization time (hrs.) and tempering temperature (oC). This study was also focused on calculating the amount of carbon penetration, the value of hardness and optimal values obtained during the optimization by Taguchi approach and MOORA method for multiple parameters. In this study, the carburization process was done in temperature between (850 to 950 ᵒC) for 2 to 6

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Publication Date
Thu Jan 04 2024
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The impact of strategic cohesion in achieving organizational prosperity: Applied research in the National Insurance Company
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Abstract

                The research aims to shed light on strategic cohesion and its dimensions represented by (strategic logic, organizational excitement, organizational founding, organizational synergy) and measure its impact on achieving organizational prosperity and its dimensions represented by (intellectual capital, innovation, infrastructure, organizational agility, sustainable competitive advantage). The research problem emerged by raising the main question, which is: Does the management of the researched company realize the importance of practicing strategic cohesion and its role in achieving organizational pros

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Publication Date
Sun Dec 09 2018
Journal Name
Baghdad Science Journal
Enhancement of the Tensile and the Compression Properties for Heat- Cured Acrylic Resin Denture Base Materials
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This work aims to investigate the tensile and compression strengths of heat- cured acrylic resin denture base material by adding styrene-butadiene (S- B) to polymethyl methacrylate (PMMA). The most well- known issue in prosthodontic practice is fracture of a denture base. All samples were a blend of (90%, 80%) PMMA and (10%, 20%) S- B powder melted in Oxolane (Tetra hydro furan). These samples were chopped down into specimens of dimensions 100x10x2.5mm to carry out the requirements of tensile tests. The compression strength test specimens were shaped into a cylinder with dimensions of 12.7mm in diameter and 20mm in length. The experimental results show a significant increase in both tensile and compression strengths when compared to cont

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Publication Date
Tue Sep 03 2024
Journal Name
Tropical Parasitology
Investigation the effect of the aqueous extract of Chara vulgaris (L.) on visceral leishmaniasis
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Abstract<sec><title>Background:

Visceral leishmaniasis (VL) is a parasitic disease that affects public health. It is described by weight reduction, irregular fever bouts, anemia, and amplification of the spleen and liver.

Materials and Methods:

Three concentrations (15.6, 31.2, and 62.5 μg/mL) were used to find the potency of an aqueous extract ofChara vulgarisalgae in the treatment of VL. A cytotoxicity assay was performed to show the cytotoxic effect of this extract on human cells. High-performance liquid chromatography (HPLC) test was done to determine the active compounds in the ext

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Publication Date
Sat Jan 01 2022
Journal Name
Journal Of Energy Storage
Intensifying the thermal response of PCM via fin-assisted foam strips in the shell-and-tube heat storage system
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