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Experimental Study on Double-Pass Solar Air Heater with and without using Phase Change Material
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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.

 

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Publication Date
Fri Jan 19 2018
Journal Name
Journal Of Global Pharma Technology
Synthesis, Characterization and Study of Electrical Properties of Some New Aromatic Polyester
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This research discloses the synthesis of various polyester resins, the polyesters containing homoring aromatic and others heterocyclic were synthesized by the condensation polymerization of suitable monomers (which are containing variety function groups in different structures) with phthalic anhydride. The main objective is synthesis of new polyester with keeping a reasonable electrical insulating behavior. The structural of polymer was characterized by Fourier Transform infra-red spectroscopy FTIR and HNMR. The dielectric constant (real ε' and imaginary parts ε") and AC conductivity (σAC) for all the polyester samples are studied by varying the frequency (30, 50, 70, 90, 120, 300, 500Hz and 1KHZ) at 25⁰ C. Indeed, study of the electri

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Publication Date
Sun Mar 27 2022
Journal Name
Journal Of The College Of Basic Education
A Cross-Cultural Study of Criticism Strategies: Iraqi and Malay ESL Learners
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        Criticism, as an evaluative criterion, is a significant speech act for English language learners to improve their speech and actions in their academic life. Yet, it is realized differently across diverse cultures. Few studies have shown that the linguistics forms of one language are different from those available in another language. Hence, this study aims to investigate the cross-cultural similarities and differences between 60 Iraqi and Malay university learners in the use of criticism strategies. The data are collected using a Discourse Completion Test (DCT) and a Focus Group Interview (FGI). The data are coded based on Nguyen’s (2005) coding scheme of criticism in terms of the realization strategies. Qualitative

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Publication Date
Sun Mar 02 2008
Journal Name
Baghdad Science Journal
Study the Band Energy Structure and Absorption Coefficient for PbSe Thin Films
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The PbSe alloy was prepared in evacuated quarts tubs by the method of melt quenching from element, the PbSe thin films prepared by thermal evaporation method and deposited at different substrate temperature (Ts) =R.T ,373 and 473K . The thin films that deposited at room temperature (R.T=303)K was annealed at temperature, Ta= R.T, 373 and 473K . By depended on D.C conductivity measurements calculated the density of state (DOS), The density of extended state N(Eext) increases with increasing the Ts and Ta, while the density of localized state N(Eloc) is decreased . We investigated the absorption coefficient (?) that measurement from reflection and transmission spectrum result, and the effect of Ts and Ta on it , also we calculated the tai

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Publication Date
Thu Dec 31 2015
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Comparative Study of New Re-Ni-Mo/Al2o3 and Conventional Hydrodesulphurization Catalyst
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New types of hydrodesulfurization (HDS) catalyst Re-Ni-Mo/ γ-Al2O3 was prepared and tested separately with two prepared conventional HDS catalysts (Ni-Mo/ γ-Al2O3 and Co-Mo//γ-Al2O3) by using a pilot plant hydrotreatment unit. Activities of three prepared hydrodesulfurization catalysts were examined in hydrodesulfurization (HDS) of atmospheric gas oil at different temperatures 275 to 350 °C and LHSV 1 to 4 h-1, the reactions conducted under constant pressure 40 bar and H2/HC ratio 500 ml/ml .Moreover, the hydrogenation of aromatic (HAD) in gas oil has been studied. HDS was much improved by adding promoter Re to the Ni-Mo/Al2O3

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Publication Date
Mon Feb 28 2022
Journal Name
Journal Of Educational And Psychological Researches
Perceptual for enrolled and not enrolled the puplis in kindergartens (comparative study)
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Enrollment in kindergarten child accomplishes many positive aspects, that’s what Im sure a lot of modern educational trends in child education preschool in the importance of exposing children to a variety of sensory stimuli that contribute to impart a range of sound concepts.

Current research aims to know:

1.the level of sensory perception in the first primary grade students a sample search.

2.differences in perception of elementary first-graders with variable gender male, female))   3.differences in perception of the first primary grade students attending and not attending kindergarten in accordance with variable attendance (attending, not attending).

school students (first grade) from attendi

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Publication Date
Sun Feb 10 2019
Journal Name
Iraqi Journal Of Physics
Electrical and morphological study of thermally evaporated (Sb2S3)1-xSnx thin films
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(Sb2S3)1-xSnx thin films with different concentrations (0, 0.05 and
0.15) and thicknesses (300,500 and 700nm) have been deposited by
single source vacuum thermal evaporation onto glass substrates at
ambient temperature to study the effect of tin content, thickness and
on its structural morphology, and electrical properties. AFM study
revealed that microstructure parameters such as crystallite size, and
roughness found to depend upon deposition conditions. The DC
conductivity of the vacuum evaporated (Sb2S3)1-x Snx thin films was
measured in the temperature range (293-473)K and was found to
increase on order of magnitude with

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Publication Date
Fri Mar 01 2019
Journal Name
Al-khwarizmi Engineering Journal
Zinc Oxide Hydrogen Sulfide Removal Catalyst/ Preparation, Activity Test and Kinetic Study
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Hydrogen sulfide removal catalyst was prepared chemically by precipitation of zinc bicarbonate at a controlled pH. The physical and chemical catalyst characterization properties were investigated. The catalyst was tested for its activity in adsorption of H2S using a plant that generates the H2S from naphtha hydrodesulphurization and a unit for the adsorption of H2S. The results comparison between the prepared and commercial catalysts revealed that the chemical method can be used to prepare the catalyst with a very good activity.

It has observed that the hydrogen sulfide removal over zinc oxide catalyst follows first order reaction kinetics with activation energy of 19.26 kJ/mole and enthalpy and e

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Publication Date
Sat Feb 15 2025
Journal Name
Iraqi Journal Of Pharmaceutical Sciences
Physician and Medical Representative Interaction in Iraqi Private Sector: A Qualitative Study
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Pharmaceutical companies assign a budget for activities and promotions that aim to change the prescription habits of the physicians to choose the most suitable medications for their patients, which will eventually grow their sales. The study's objectives were to explore physicians' and medical representatives' perspectives on the criteria of impactful professional PP and the factors influencing the interaction between physicians and medical representatives. Qualitative in-depth interviews with flexible probing techniques were carried out in 2023. A semi-structured, open-ended interview questionnaire was used to interview physicians and medical representatives (MRs) from different private clinics in several governorates in Iraq. Ten physicia

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Publication Date
Sun Feb 10 2019
Journal Name
Journal Of The College Of Education For Women
Psychological Burnout for Teachers of Kindergarten Public and Private (A Contrastive Study)
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The psychological burnout is considered one of dangerous phenomenon’s which appeared in the 70s of the 20th century and suffered by most of the society classes. It is a term which the wide uses and various meaning like emotional, mental, and physical exhaustion and chronic weak exhaustion. The presented research aims t identify the psychological burnout as for the Kindergarten teacher and the differences significance according to the variations (Kindergarten type: private or govern mental). The research sample contains 400 female teachers divided to 170 governmental Kindergarten teachers and 230 private Kindergarten teachers. The researcher prepared a measurement method to measure the psychological burnout for those teachers after

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Publication Date
Thu Apr 01 2021
Journal Name
Iop Conference Series: Earth And Environmental Science
Comparative study for Environmental Impact Assessment in Environmental Iraqi and Saudi legislation
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Abstract<p>Countries are developing the spatial development of their societies through the projects that they undertake in various ways, and this development may be cause great impact on the environment, which also depend on the type of development, whether industrial, agricultural, or service and after the problems that occurred as a result of development on the environment, most of the countries currently did to legislating laws Environmental and some other procedures before granting environmental approvals for the purpose of establishing spatial development projects. One of the most important of these laws and regulations is Environmental impact assessment (EIA). The environmental impact asse</p> ... Show More
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