In this study, thermal characteristics of a two-phase closed heat pipe were investigated experimentally and theoretically. A two-phase closed heat pipe (copper container, Fluorocarbon FC-72 (C6F14) working fluid) was fabricated to examine its performance under the effect of input heat flux range of 250–1253 W/m2 , 70% fill charge ratio and various tilt angles. The temperature distribution along the heat pipe, input heat to evaporator section, and output heat from condenser were monitored. A comprehensive mathematical model was developed to investigate the steadystate heat transfer performance of a two-phase closed heat pipe. A steady state analytical model, is presented to determine important parameters on the design of two-phase closed heat pipe, including temperature levels and heat transfer coefficients for condenser and evaporator. The experimental and simulation results of this work are found in good agreement. The experimental boiling heat transfer coefficients were compared with existing previously reported correlations.
For a long time, the intensification of profit represented a major goal for the company management ,but this goal confirmed a series of restrictions such the constriction on short period, the time rather than on long and medium strategic goal, the relationships with customers ,the supplies, employees , This goal is replaced by another one (intensification of the company's value) ,and the fortune of the share holders itself ,for the purpose of creating value, the company must generate great outcomes to cover the operating expense and to insure the a suitable compensation to the invested capital (the market value added) is the indication used to estimate the company ability to create value –added the development
... Show MoreABSTRACT Background: One of the major problems of all ceramic restorations is their probable fracture against the occlusal forces. The objective of this in vitro study was to evaluate the effect of two gingival finishing lines (90°shoulder and deep chamfer) on the fracture resistance of full contour CAD/CAM and heat press all-ceramic crowns. Materials and Methods: Thirty two maxillary first premolars were prepared to receive full contour CAD/CAM (zolid) and heat press (Cergo Kiss) ceramic crowns using a special paralleling device (Parallel-A-Prep). The teeth were divided into four groups according to the type of finishing line prepared. Each crown was cemented to its corresponding tooth using self-etch, self-adhesive dual cure resin ceme
... Show MoreThe present study was conducted to investigate the effect of adding various levels of Optifeed®, VêO® premium and Oleobiotec® to the diets as appetite stimulants in the production Performance of broiler males under heat stress conditions. The experiment was done for 42 days for the period from 30 August 2018 to 11 of October 2018 at the Poultry Research Station of the Livestock Research Department / Agricultural Research Department / Ministry of Agriculture (Baghdad - Abu Ghraib). In this study, 270 - one-day broiler males (Ross 308) were reared with the mean body weight of 37 g/chick, distributed randomly on 18 pens with dimensions of 2 x 3 m (length x width). The experimental treatments involved six treatments with three repli
... Show MoreThis study expands the state of the art in studies that assess torsional retrofit of reinforced concrete (RC) multi-cell box girders with carbon fiber reinforced polymer (CFRP) strips. The torsional behavior of non-damaged and pre-damaged RC multi-cell box girder specimens externally retrofitted by CFRP strips was investigated through a series of laboratory experiments. It was found that retrofitting the pre-damaged specimens with CFRP strips increased the ultimate torsional capacity by more than 50% as compared to the un-damaged specimens subjected to equivalent retrofitting. This indicated that the retrofit has been less effective for the girder specimen that did not develop distortion beforehand as a result of pre-loading. From
... Show MoreThis study expands the state of the art in studies that assess torsional retrofit of reinforced concrete (RC) multi-cell box girders with carbon fiber reinforced polymer (CFRP) strips. The torsional behavior of non-damaged and pre-damaged RC multi-cell box girder specimens externally retrofitted by CFRP strips was investigated through a series of laboratory experiments. It was found that retrofitting the pre-damaged specimens with CFRP strips increased the ultimate torsional capacity by more than 50% as compared to the un-damaged specimens subjected to equivalent retrofitting. This indicated that the retrofit has been less effective for the girder specimen that did not develop distortion beforehand as a result of pre-loading. From
... Show MoreMature oil reservoirs surrounded with strong edge and bottom water drive aquifers experience pressure depletion and water coning/cresting. This laboratory research investigated the effects of bottom water drive and gas breakthrough on immiscible CO2-Assisted Gravity Drainage (CO2-AGD), focusing on substantial bottom water drive. The CO2-AGD method vertically separates the injected CO2 to formulate a gas cap and Oil. Visual experimental evaluation of CO2-AGD process performance was performed using a Hele-Shaw model. Water-wet sand was used for the experiments. The gas used for injection was pure CO2, and the “oleic” phase was n-decane with a negative spreading coefficient. The aqueous phase was deionized water. To evaluate the feasibilit
... Show MoreCyclophosphamide is chemotherapeutic agent that utilized for the treatment of different malignancies; however its’ used associated with numerous adverse effects. Vitamin B2 and vitamin B12 suggested having myeloprotective effect. This work is designed to investigate the myeloprotective effect of both vitamins against cyclophosphamide induced myelosuppression. One hundred adult rats of both sexes were used in this study. The animals were randomly enrolled into ten groups of 10 rats each. Group I: Control group. Group II: Cyclophosphamide-treated. Group III and Group IV Orally-administered vitamin B2 (10, and 40 mg/kg/day), respectively alone for 7 days. Group V:
... Show MoreEducation specialists have differed about determining the best ways to detect the
talented. Since the appearance of the mental and psychological measurement movement, some
scholars adopted intelligence ratios as a criterion to identify the talented and others went to
rely on the degree of academic achievement. Each of these two methods has its own flaws and
mistakes and a large number of talented children were victims of these two methods.
Therefore the need to use other scales for the purpose of detection of talented children
appeared because they provide valuable information which may not be obtained easily
through objective tests and these scales are derived from consecutive studies of gifted andtalented children