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Investigation of Optimum Heat Flux Profile Based on the Boiling Safety Factor
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An experimental study is conducted to investigate the effect of heat flux distribution on the boiling safety factor of its cooling channel. The water is allowed to flow in a horizontal circular pipe whose outlet surface is subjected to different heat flux profiles. Four types of heat flux distribution profiles are used during experiments: (constant distribution profile, type a, triangle distribution profile with its maximum in channel center, type b, triangle distribution profile with its maximum in the channel inlet, type c, and triangle distribution profile with its maximum in the channel outlet, type d). The study is conducted using heat sources of (1000 and 2665W), water flow rates of (5, 7 and 9 lit/min). The water temperature at cooling channel inlet is kept constant at (25°C). Copper test section of (0.6 m) length (0.025m) inner diameter is used during the experiments. The electrical heater used for water heating is wrapped around the copper pipe covering (50 cm) of its length. Calibrated thermocouples are distributed along pipe surface at distances (0.1, 0.2, 0.3, 0.4 and 0.5 m) from pipe inlet to measure pipe surface temperature. The results shows that the heat source with heat flux profile of type (c) is the most reliable one from thermo-hydraulic safety point of view for both types of heat sources, as it ensures a maximum boiling safety factor (K) of (1.6, 1.7, 2) at water flow rates of (5, 7 and 9 lit/min) respectively based on maximum heat capacity of (2665 w), while the heat source with heat flux profile of type (d) which posses minimum boiling safety factors of (1, 1.2, 1.3) at water flow rates of (5, 7 and 9 lit/min) respectively based on same heat capacity value is the worst one from same point of view.

 

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Publication Date
Fri Dec 29 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Optimum Time Schedule for Industrial Processes (II)
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The  present study  deals  with successive  stages  of  productive

operations happened to produce a production within each stage befo re it  moves to the next one. ll cou ld  be deduced that this study is an extension  to what bas  been mentioned  in (1 ) .ln  (I),  the  optimum distribution of  di!Terent jobs of  workers and  machines  in  the productive operations has been st ud ied whi le the study  invol ves the optimum schedule for the succession of these operations presuming that thay have already been distributed on machines and workers (2).A mathematical form has been put for this study to define the "Object.ive Function "

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Publication Date
Mon Aug 01 2022
Journal Name
مجلة الرافدين للعلوم الرياضية
Fartlek exercises and their effect on molecular biology (vascular endothelial growth factor-basic fibroblast growth factor) and some physical variables for players 800m arena and field for youth
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The study aimed to : - To determine whether there are significant differences between Fartlek training and the increase in the molecular biology (VEGF - basal fibroblast growth factor) for arena and field players in an (800m) youth event. - Determine whether there are statistically significant differences between Fartlek training and the increase in molecular biology and some physical variables for the players (800m) in the arena and field for youth. - Determine whether the Fartlek training method is the most appropriate to achieve statistically significant differences in the research variables for the players (800m) in the arena and field for youth. The researchers used the experimental method for its suitability and the nature of the rese

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Publication Date
Sun Jan 13 2019
Journal Name
Iraqi Journal Of Physics
Measurement of background radiation, cosmic ray flux and their hazard parameter of Baghdad city districts
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The aim of this work was directed to measure the cosmic ray (CR)
flux and the background (BG) absorbed dose rate for districts of
Baghdad city. The maximum values of CR flux was 2.01
(particle/cm2.s) registered for several Baghdad districts and the
minimum was 0.403 (particle/cm2.s) belonging to Al-kadhimiya
district, whereas the overall average value was 1.24 (particle/cm2.s).
The BG measurements showed that the maximum absorbed dose was
25 nSv/h belonging to Noab AL-Dhbat district and the minimum
absorbed was 19.01 nSv/h observed in Al-Ghadeer district, while
the overall average was 22.56 nSv/h, and this value is small than the
Iraqi permissible limit, which is restricted by Iraqi Center of
Radiation Pr

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Publication Date
Thu Dec 31 2009
Journal Name
The Iraqi Journal Of Veterinary Medicine
Possible beneficial effects of amlodipine, lisinopril, and their Combination on lipid profile in hypertensive patients
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It is well known that monotherapy does not provide therapeutic response in all hypertensive. Somepatients show an excellent response, while in others there is a poor response. Combinationantihypertensive therapy is administered when blood pressure is inadequately controlled bymonotherapy to achieve a balanced and additive antihypertensive effect with minimum adverse effects.Both angiotensin converting enzyme (ACE) inhibitors and dihydropyridine type of calcium antagonistsare well established and widely used in monotherapy. An understanding of differences in themechanism of action of these agents allows a logical approach for the use of these agents as acombination therapy. This study was designed to evaluate the possible beneficial

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Publication Date
Thu Mar 30 2023
Journal Name
Al-mustansiriyah Journal Of Science
Seasonal Optimum Tilt Angle of Solar Panels for 100 Cities in the World
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Solar energy is the most abundant renewable energy source. This energy can be converted directly into electricity using solar panels. The fixed tilt solar panels are the most practical and the most widely installed throughout the world. Optimum tilt angle calculation has the advantage that it does not use expensive solar trackers. This research calculates the seasonal optimum tilt angle of solar panels for 17 cities in Iraq and 83 cities in 83 countries distributed around the world. Solar Panel Angle Calculator program was used in calculating the optimum tilt angles from vertical. The optimum tilt angle varies between 6° and 112° throughout the year. This angle for winter, spring/ autumn and summer seasons are found to be between

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Publication Date
Fri Jan 03 2020
Journal Name
Chalcogenide Letters
THE EFFECT OF Ag CONTENT AND HEAT TREATMENT ON STRUCTURAL AND MORPHOLOGICAL PROPERTIES OF THIN (Cu1-xAgx)2 ZnSnSe4 FILMS
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(Cu1-x,Agx)2ZnSnSe4 alloys have been fabricated with different Ag content(x=0, 0.1, and 0.2) successfully from their elements. Thin films of these alloys have been deposited on coring glass substrate at room temperature by thermal evaporation technique under vacuum of 10-5Torr with thickness of 800nm and deposition rate of 0.53 nm/sec. Later, films have been annealed in vacuum at (373, and 473)K, for one hour. The crystal structure of fabricated alloys and as deposited thin films had been examined by XRD analysis, which confirms the formation of tetragonal phase in [112] direction, and no secondary phases are founded. The shifting of main polycrystalline peak (112) to lower Bragg’s angle as compared to Cu2ZnSnSe4 angle refers to incorpora

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Publication Date
Sun Jan 05 2014
Journal Name
Paripex - Indian Journal Of Research
Effect of heat treatment on the structural and optical properties of CuIn1-xGaxSe thin films
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The structural, optical properties of cupper indium gallium selenite (CuIn1-xGaxSe) have been studied. CuIn1-xGaxSe thin films for x=0.6 have been prepared by thermal evaporation technique, of 2000±20 nm thickness, with rate of deposition 2±0.1 nm/sec, on glass substrate at room temperature. Heat treatment has been carried out in the range (373-773) K for 1 hour. It demonstrated from the XRD method that all the as-deposited and annealed films have polycrystalline structure of multiphase. The optical measurement of the CIGS thin films conformed that they have, direct allowed energy gap equal to 1.7 eV. The values of some important optical parameters of the studied films such as (absorption coefficient, refractive index, extinction coeffici

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Publication Date
Wed Jun 15 2022
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of Optiglaze Coating on the Staphylococcus aurous and Porosity of Heat Cured Acrylic Material
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Background: Polishing technique for acrylic resin material have great effect on properties of acrylic material and bacterial colonization such as staphylococcus aurous, which are responsible for many acrylic prosthetic infections such as the commonly ocular infections. Ineffective polishing technique could affect roughness and subsequently porosity of acrylic materials.So, a new effective method for polishing acrylic was used depending on the use of optiglaze coating material. So, this study aimed to evaluate the effect of optiglaze polishing on porosity of acrylic resin material and staphylococcus aurous activity in comparison to conventional polishing technique. 

Materials and methods: Specimen(n=120) were prepared :20 spe

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Publication Date
Sun May 22 2005
Journal Name
University Of Technology
Results Of The Factor Group CF(G,Z)/R(G)
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Publication Date
Tue Dec 30 2014
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Performance Evaluation of Three Phase Spray Direct Contact Heat Exchanger
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The present investigation deals with experimental study of three-phase direct-contact heat exchanger, for water-Freon R11 system, where water is the continuous phase (liquid) and Freon R11 (liquid-gas) is the dispersed phase. The test section consisted of a cylindrical Perspex column with inner diameter 8cm and 1.2m long, in which, water was to be confined. Liquid Freon R11 drops were injected into the hot water filled column, through a special design of distributors at the bottom of the column. The liquid Freon R11 drops rose on their way up and evaporated into two-phase bubbles at atmospheric pressure. The study was devoted to express the effect of process variables such as c

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