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Experimental Study of Optimum Chilled Water Distribution Configuration in Air Conditioning Terminal Unit Using RSM Technique
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The distribution of chilled water flow rate in terminal unit is an important factor used to evaluate the performance of central air conditioning unit. A prototype of A/C unit has been made, which contains three terminal units with a complete set of accessories (3-way valve, 2-way valve, and sensors) to study the effect of the main parameters, such as total water flow rate and chilled water supply temperature with variable valve opening. In this work, 40 tests were carried out. These tests were in two groups, 20 test for 3-way valve case and 20 test for 2-way valve case. These tests were performed at three levels of valve opening, total water flow rate and water supply temperature according to the design matrices established by Design of Experiment (DOE) software 'version 7' with Response surface methodology (RSM) technique. The model was conducted for each case of total heat rate, then checked statistically for adequacy by Analysis of variance (ANOVA), and found good with 95% confidence level. The results showed that the water supply temperature has a significant effect on the total heat rate of two cases. It was found that the optimum solution for maximum total heat rate and minimum flow deviation represented by standard deviation was obtained at 10°C water supply temperature, 5.5 l/min total water flow rate and 70% valve opening. The total heat rate and standard deviation were (890.249 Watt), (0.000513), respectively in three-way valve case and (743.155 Watt), (0.00277), respectively in two-way valve case. Finally, the predicted and experimental results of total heat rate and standard deviation were in agreement with a maximum error of 6.6 % in three-way valve case and 1.4% in two-way valve case.

 

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Publication Date
Thu Mar 31 2016
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study of the Performance of Compound Parabolic Concentrating Solar Collector
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The design, construction and investigation of experimental study of two compound parabolic concentrators (CPCs) with tubular absorber have been presented. The performance of CPCs have been evaluated by using outdoor experimental measurements including the instantaneous thermal efficiency. The two CPCs are tested instantly by holding them on a common structure. Many tests are conducted in the present work by truncating one of them in three different levels. For each truncation the acceptance half angle (θc) was changed. Geometrically, the acceptance half angle for standard CPC is (26o). For the truncation levels for the other CPC 1, 2 and 3 the acceptance half angle were 20o, 26o and 5

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Publication Date
Sun Jul 02 2023
Journal Name
Iraqi Journal Of Science
Optimum Condition for Asparginase Activity in Crude Extract of Capiscum annum
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In this study asparaginase was extracted from fruit part of Capiscum annum then Asparaginase activity was detected and optimised. Optimum conditions for the activity of crude asparaginase were studied. Results showed maximum activity of asparaginase was achieved 140 u/ml when the enzyme was incubated with 200 mM of asparagines at 35 °C for 30 minutes in the presence of 0.05 M of potassium phosphate buffer solution at pH 8.

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Publication Date
Sun Oct 22 2023
Journal Name
Iraqi Journal Of Science
Optimum Condition for Asparginase Activity in Crude Extract of Capiscum annum
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In this study asparaginase was extracted from fruit part of Capiscum annum then Asparaginase activity was detected and optimised. Optimum conditions for the activity of crude asparaginase were studied. Results showed maximum activity of asparaginase was achieved 140 u/ml when the enzyme was incubated with 200 mM of asparagines at 35 °C for 30 minutes in the presence of 0.05 M of potassium phosphate buffer solution at pH 8.

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Publication Date
Sun Jan 26 2020
Journal Name
Iraqi Journal Of Science
Electro polymerization for (N-Terminal tetrahydrophthalamic acid) for Anti-corrosion and Biological Activity Applications
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The present work reports the electrochemical synthesis of poly N Terminal tetrahydrophthalamic acid on stainless steel 316 (S.S), which acts as a working electrode, using an electrochemical polymerization technique. Fourier Transform Infrared Spectroscopy (FT-IR), Atomic Force Microscope (AFM) and Scanning Electron Microscope (SEM) characterized the formed polymer film. Corrosion protection tests for coated and uncoated S.S with polymer film were studied in 0.2 M hydrochloric acid (HCl) solution by using electrochemical polarization technique. Kinetic and thermodynamic activation parameters (Ea, A, ΔH*, ΔS* and ΔG*) were calculated. The biological activity of the polymeric film was determined against Gram positive (Staphy

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Publication Date
Mon Mar 29 2021
Journal Name
Eureka: Physics And Engineering
INVESTIGATION ON THE AIR-GAS CHARACTERISTICS OF AIR-HYDROGEN MIXER DESIGNED FOR DUAL FUEL – ENGINES
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High smoke emissions, nitrogen oxide and particulate matter typically produced by diesel engines. Diminishing the exhausted emissions without doing any significant changes in their mechanical configuration is a challenging subject. Thus, adding hydrogen to the traditional fuel would be the best practical choice to ameliorate diesel engines performance and reduce emissions. The air hydrogen mixer is an essential part of converting the diesel engine to work under dual fuel mode (hydrogen-diesel) without any engine modification. In this study, the Air-hydrogen mixer is developed to get a homogenous mixture for hydrogen with air and a stoichiometric air-fuel ratio according to the speed of the engine. The mixer depends on the balance between th

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Publication Date
Mon Feb 04 2019
Journal Name
Journal Of The College Of Education For Women
Using Index of Compaction in interpreting the distribution and shapes of soil map units of Lower Diyala project.: Using Index of Compaction in interpreting the distribution and shapes of soil map units of Lower Diyala project.
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Abstract
This study was conducted by using soil map of LD7 project to interpret the
distribution and shapes of map units by using the index of compaction as an
index of map unit shape explanation. Where there were wide and varied
ranges of compaction index of map units, where the maximum value was
0.892 for MF9 map unit and the lower value was 0.010 for same map unit.
MF9 has wide range appearance of index of compaction after those indices
were statistically analyzed by using cluster analysis to group the similar
ranges together to ease using their values, so the unit MF9 was considered as
key map unit that appears in the soils of LD7 project which may be used to
expect another map units existence in area of

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Publication Date
Tue Jun 01 2021
Journal Name
Iraqi Journal Of Physics
Synthesis of Cinnamon Nanoparticles by Using Laser Ablation Technique
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    The natural  polyphenolic  compound that cinnamon contains is well known for its various biological activities, a broad variety of pharmacological and therapeutic properties.  Diversified biomedical and pharmacological applications benefit from organic nanoparticles with controlled properties. Bioactive and non-toxic, cinnamon nanoparticles (CNPs) can be effective antibacterial agents. Driven by this idea, we prepared spherical CNPs using liquid (PLAL) pulse laser ablation technique and defined those NPs. Using Q-switched Nd : YAG With a wavelength of 1064 nm  pulse laser of constant energy 500 mj , And different laser pulses ( 250 , 500 , 750 , 1000 ) pulse /sec a pure cinnamon target submerged in

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Publication Date
Sat Sep 30 2017
Journal Name
Al-khwarizmi Engineering Journal
Delignification of Date Palm Fronds using Modified Organosolv Technique
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Abstract

  In this study, modified organic solvent (organosolv) method was applied to remove high lignin content in the date palm fronds (type Al-Zahdi) which was taken from the Iraqi gardens. In modified organosolv, lignocellulosic material is fractionated into its constituents (lignin, cellulose and hemicellulose). In this process, solvent (organic)-water is brought into contact with the lignocellulosic biomass at high temperature, using stainless steel reactor (digester). Therefor; most of hemicellulose will remove from the biomass, while the solid residue (mainly cellulose) can be used in various industrial fields. Three variables were studied in this process: temperature, ratio of ethano

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Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Engineering
Fabrication of Copper-Graphite MMCs Using Powder Metallurgy Technique
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Copper, and its, alloys and composites (being the matrix), are broadly used in the electronic as well as bearing materials due to the excellent thermal and electrical conductivities it has.

In this study, powder metallurgy technique was used for the production of copper graphite composite with three volume perc ent of graphite.  Processing parameters selected is (900) °C sintering temperature and (90) minutes holding time for samples that were heated in an inert atmosphere (argon gas). Wear test results showed a pronounced improvement in wear resistance as the percent of graphite increased which acts as solid lubricant (where wear rate was decreased by about 88% as compared with pure Cu). Microhardness and

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Publication Date
Sun Dec 30 2018
Journal Name
Baghdad Science Journal
Electronic Structure of Copper Antimony Using Compton Scattering Technique
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In this paper we present the first ever measured experimental electron momentum density of Cu2Sb at an intermediate resolution (0.6 a.u.) using 59.54 keV 241Am Compton spectrometer. The measurements are compared with the theoretical Compton profiles using density function theory (DFT) within a linear combination of an atomic orbitals (LCAO) method. In DFT calculation, Perdew-Burke-Ernzerhof (PBE) scheme is employed to treat correlation whereas exchange is included by following the Becke scheme. It is seen that various approximations within LCAO-DFT show relatively better agreement with the experimental Compton data. Ionic model calculations for a number of configurations (Cu+x/2)2(Sb-x) (0.0≤x≤2.0) are also performed utilizing free a

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