The current study presents an experimental investigation of heat transfer and flow characteristic for subcooled flow boiling of deionized water in the microchannel heat sink. The test section consisted of a single microchannel having 300μm wide nominal dimensions and 300μm height (hydraulic diameter of 300μm). The test section formed of oxygen-free copper with 72mm length and 12mm width. Experimental operation conditions spanned the heat flux (78-800) kW/m2, mass flux (1700 and 2100) kg/m2.s at 31˚C subcooled inlet temperature. The boiling heat transfer coefficient is measured and compared with existing correlations. Also, the experimental pressure drop is measured and compared with microscale pressure drop correlations. The results showed that higher mass flux leads to higher boiling heat transfer coefficient, and the dominant mechanism is convective boiling. Also, the experimental pressure drop decrease with increasing heat flux in a single-phase region while it increases in a two-phase region. Comparing the experimental results in the experimental condition range, showed that an existing correlation provides a satisfactory prediction of heat transfer coefficient and pressure drop.
An acidic environment causes surface changes of resin composites. Filler particlesize and filler distribution also have a direct effect on these surface changes. This invitro study evaluated the influence of Pepsi Cola drink on the surface roughness ofComposan LCM and Composan Ceram over time. Sixteen disc shaped specimens(10mm diameter, 2mm thickness) of each resin composite were fabricated, therebyforming two groups (n= 8). Surface roughness (Ra) was analyzed after 24 hrs beforeexposure to beverage. The specimens were submitted to a five minutes immersion inPepsi Cola three times daily interrupted by immersion in deionized distilled water (37C˚). Surface roughness measurements were done at 10, 30, and 60 days intervals. Datawere
... Show MoreThe present study was conducted in the Tigris River within Baghdad (University of Baghdad campus). The study included some physicochemical parameters and qualitative of epiphytic algae on the host plant (Ceratophyllum demersum) during summer season 2013. The results revealed that the study area was alkaline, hard and oxygenated water. A total of 105 taxa of epiphytic algae was identified. Bacillariophyceae diatoms composed 44.7% of the total and were represented by 42.4% of the order Pennales and 1.9 %of the order Centrales. Chlorophyceae composed 32.3%, followed by Cyanophyceae composed 22.8 % of the total. The total number of epiphytic algae was fluctuated among the study period. Most of the identified algae were benthos type and a few
... Show MoreResearch on the role of organizational change in easing the organizational conflict focuses for being one of the important topics and relatively modern and which have a significant impact on the future of organizations, so this study was to identify the relationship and the impact of organizational change and of deportation (technological, organizational structure, human resources, the change in the task) at the organizational conflict in the Earth company link Iraq, in order to reach the goals of the research, it has been the development of a questionnaire distributed to a random sample of (100) composed employees from managers and heads of departments and the people and staff at the Earth company link Iraq, the study found: the
... Show MorePreparing teacher occupies the attention of many thinkers and philosophers since the age of
kaldinics ( people of mesoptam / 2342 pH ) to the Islamic age where moslems philosophers
focus their attention on thought and philosophy where the philosophy of that teaching
depends on : teacher , student and family begin .
So , the issue of preparing and training teacher occupies the attention of education scientists
depending on his vital and important role in implementing of teaching policies in philosophies
and Islamic educational thought , therefore , the preparing and development of the teacher
regards as one of the basics of teaching development because of its importance in
development of teaching performance and th
Introduction: Articaine was developed in 1969, with reported advantages which are increased potency, increased duration of its anesthetic effect and superior diffusion through bony tissue. The effectiveness of using 4% articaine infiltration for extraction of mandibular molar teeth in comparison to 2% lidocaine inferior alveolar nerve block is not settled yet. Aim: The aim of this study was to evaluate the effectiveness of using 4% articaine infiltration for extraction of mandibular molars by comparing it to the use of 2% lidocaine inferior alveolar nerve block in terms of success, the volume of local anesthetic agents and the pain experienced during the procedure. Materials and methods: A prospective randomized controlled study included
... Show MoreIntroduction: An aneurysmal bone cyst are enigmatic lesion of unknown cause and presentation and are difficult to distinguish from other lesions, it is a benign, but expansible tumor like lesion that generally occurs in the long bones. An aneurysmal bone cyst arising from the flat bone like clavicle is rare . Case presentation: We report a 12-year-old girl child with an aneurysmal bone cyst of the lateral third of left clavicle treated with enblock resection. The pathologic findings confirmed the diagnosis of aneurysmal bone cyst. The patient has been followed up for one year with no evidence of recurrence . Conclusion: En bloc resection can be curative and provide good results for this rare type of clavicle tumour.
Objective: The aim of this study is to find out the impact of life events upon onset of depression, to describe the
prevalence of life events among depressed patients.
Methodology: Retrospective a case-control study conducted in AL-Diwanyia Teaching Hospital, Psychiatric
Department on A non-probability (purposive sample) of (60) depressed patients and (60) of healthy person were matched
with them from general population. The data were collected through the use of semi-structured interview by
questionnaire, which consists of two parts (1) divide, section A. cover letter and B. Sociodemographic data which consists
of 9-items, (2) Life events questionnaire consists of 51-items distributed to six dimensions include, family
In globalization, the world became open area to competition for the attractive of investment, and the abilities of each country to win the confidence of investors depend upon the preparation to optimize circumstances. The competitiveness is an essential means of expanding the capacity of developed to coexist in an international environment characterized by globalization. While competition describes the market structure, the behavior of investors and business, competitiveness is interested in the evaluation of business performance or countries and compare them in the conditions of competition available in these markets. Regarding Malaysia, which is depend on FDI-Export- Led Growth strategy, it has taking on diffe
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The research aims to identify the factors that affect the quality of the product by using the Failure Mode and Effect Analysis (FMEA) tool and to suggest measures to reduce the deviations or defects in the production process. I used the case study approach to reach its goals, and the air filter product line was chosen in the air filters factory of Al-Zawraa General Company. The research sample was due to the emergence of many defects of different impact and the continuing demand for the product. I collected data and information from the factory records for two years (2018-2019) and used a scheme Pareto Fishbone Diagram as well as an FMEA tool to analyze data and generate results.
Par
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