Heat exchanger is an important device in the industry for cooling or heating process. To increase the efficiency of heat exchanger, nanofluids are used to enhance the convective heat . transfer relative to the base fluid. - Al2O3/water nanofluid is used as cold stream in the shell and double concentric tube heat exchanger counter current to the hot stream basis oil. These nanoparticles were of particle size of 40 nm and it was mixed with a base fluid (water) at volume
concentrations of 0.002% and 0.004%. The results showed that each of Nusselt number and overall heat transfer coefficient increased as nanofluid concentrations increased. The pressure drop of nanofluid increased slightly than the base fluid because of the low concentration used.
After 2003 Iraq witnessed a rapid development in the number and kind of non-governmental organizations in addition to the increase in their sources.A lot of obstacles and constraints hinder the development of the said organizations and one of the most important and prominent obstacles is their administrative and accounting structure that affect directly on the existence, continuity and survival of these organizations.This research discussed the concept the non-governmental organizations and reaching the assessment of internal control System in these organizations. Therefore, the researcher has assessed the internal control System applied National Olympic Committee of Iraq. The study showed vulnerabilities in the internal control the said
... Show MoreThe degree of the woman’s satisfaction on clothing depends, to a large extent, on the body measurements. If clothing is very wide, it shows her enormous and if it is too tight it may draw attention to the defects of the body. It may also lead to the compatibility or incompatibility of clothing with fashion. Whatever the quality of the garment in terms of sewing and design, the costume which is not suitable for body size may affect the physical style negatively and may give the wearer an improper look. Clothing was carried out without measurements and did not use models (templates). The method of preparation affected the overall appearance because it often did not fit the shape of the body completely. Therefore, people thought in many w
... Show MorePhytophagous stink bugs (Hemiptera, Pentatomidae) are economically important insect pests of fruit, vegetable, nut and field crops. This study was carried out during the season of 2013 in orchards within Erbil city, to follow the stink bug Mustha spinulosa (Lefebvre, 1831) seasonal fluctuation on some fruit trees: olive, plum, apricot, pear, apple and almond.
The stink bug reaches its maximum abundance throughout the second week of August (38.2/tree) coinciding with mean temperature and relative humidity of 33.40C and 28.14% respectively, and the highest total mean of the number of the insect was recorded on the olive trees (181.8/tree). The study reveals that the stink bug attacked 22 trees (fruit and forest) while it has not atta
Background: Due to the variations in tooth anatomy and size among different populations, this study aimed to compare the mesiodistal width of primary second molars in Iraqi children with the mesiodistal width of stainless-steel crowns from different companies. Materials and Methods: This cross-sectional study was conducted on 220 intact maxillary and mandibular primary second molars selected from boys and girls’ Iraqi children aged 8-9 years collected from different primary schools in Baghdad city. The mesiodistal dimensions of the selected teeth and the available maxillary and mandibular stainless-steel crowns from three different companies were measured by using a 3-D scanner, and then the whole measurements were calculated usin
... Show MoreAbstract
This research aims to know the effect of job burnout in the worker’s performance. The researcher presented a theoretical basis for job burnout and the worker's performance. In order to achieve the objectives of the research, a hypothesis was drawn up that determines the nature of the relationship between the independent variable of job burnout and its dimensions (reduced personal accomplishment, depersonalization, Emotional Exhaustion) and variable dependent performance of workers dimensions (productivity, job satisfaction, organizational commitment, creativity), And to represent the volume of this community according to (de Morgan, D. Morgan) glo
... Show MoreThe purpose of this study was to investigate the effect of six thinking hats on creative thinking among 10th grade female students in Tulkarm district. The sample comprises two sections of 10th grade female students (n=80) in Adawiya secondary School, The two sections were divided into two groups; one as an experimental group which works with six thinking hats, and the second as control group that learns traditionally. Creative thinking exam was used to measure the creative thinking with reliability (0.88).
The results of the study have shown the following:
There were statistically significant differences at (α ≤ 0.05) in the creative thinking among 10th grade female student
... Show MoreFormation of Au–Ag–Cu ternary alloy nanoparticles (NPs) is of particular interest because this trimetallic system have miscible (Au–Ag and Au–Cu) and immiscible (Ag– Cu) system. So there is a possibility of phase segregation in this ternary system. At this challenge it was present attempts synthetic technique to generate such trimetallic alloy nanoparticles by exploding wire technique. The importance of preparing nanoparticles alloys in distilled water and in this technique makes the possibility of obtaining nanoparticles free of any additional chemical substance and makes it possible to be used in the treatment of cancer or diseases resulting from bacterial or virus with least toxic. In this work, three metals alloys Au-Ag-Cu
... Show MoreThe manganese doped zinc sulfide nanoparticles were synthesized by simple aqueous chemical reaction of manganese chloride, zinc acetate and thioacitamide in aqueous solution. Thioglycolic acid is used as capping agent for controlling the nanoparticle size. The main advantage of the ZnS:Mn nanoparticles of diameter ~ 2.73 nm is that the sample is prepared by using non-toxic precursors in a cost effective and eco-friendly way. The structural, morphological and chemical composition of the nanoparticles have been investigated by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) with energy dispersion spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy. The nanosize of the prepared nanoparticles was elucidated by Scan
... Show MoreThe Department of Art Education in the College of Fine Arts is one of the educational institutions that aims to prepare teachers specialized in teaching art education in secondary schools and other educational institutions, which forces those in charge of preparing the curricula for this section and developing it, taking into account the rapid scientific and technological development. And the subject (Music Appreciation) is one of the subjects taught for the third grades in Art Education departments, and through the exploratory study carried out by the researcher it became clear to him that the Faculties of Fine Arts agreed to define their educational objectives and outputs in the subject (Music Appreciation) in Art Education departments
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