Abstract: In the present work, the heat transfer of Nano Aluminum Oxide -NAO- has been studied practically to define the appropriate insulation conditions. This study focuses on finding of the amount of heat transfer through a glass substrate that is coated with nanoalumina doped on PMMA matrix. The optical and thermal properties were systematically investigated. The density of heat flow rate, was calculated in the range values (240-260) W/m2 while the optimum values confine between (250-260) W/m2 at temp. (25-35)Co. The results showed that the thermal insulation of the sample was significantly enhanced at temp. (30-50)Co. The simulated net heat transfer through window decreased linearly with increase of both of coating thickness concentration. Furthermore, the overall transmittance in the visible region and reflectance in infrared and ultraviolent regions decrease with increasing of weight content of the coated film.
Background: Deterioration of maxillofacial silicone properties due to microbial colonization is a common problem and leads to the replacement of the prosthesis. Incorporation of the antimicrobial agent into the silicone could be a solution. The purpose of this study was to evaluate the effect of silver-zinc zeolite addition on some mechanical properties of a maxillofacial silicone (VST-50). Materials and methods: Total 120 specimens were fabricated and divided into 3 groups: 40 specimens for tear strength test, 40 specimens for tensile and percentage of elongation tests and 40 specimens for Shore A hardness and surface roughness. Each group was divided into 4 subgroups according to the amount of zeolite added (0% “control”, 0.5%, 1% and
... Show MoreNo-fine concrete (NFC) is cellular concrete and it’s light weight concrete produced with the exclusion of sand from the concrete. This study includes the mechanical properties of lightweight reinforced by steel fiber, containing different proportions of steel fiber. This study was done using number of tests. These tests were density, compressive strength, flexural strength and absorption. These tests of the molds at different curing time. The results of tests that implication of fiber to No. fine concrete did not affect significantly on the compressive strength, While the flexural strength were gets better. Results explained that, the flexural strength of (1%) fiber No- fine concrete molds are four times that of the reference mold
... Show MoreThe crude aqueous extract of menthespicata , the objective of this study was to investigate the effects of this extraction , on the histological changes of the ovares and levels of sex hormone , ( FSH , LH , Estradiol ) in albino female mice . the extract was given orally for( 45 ) days . fourty mature female mice were used in this study , the animals divided into four major groups . each group was include ten mice . the first three groups was given different concentration )) (21 , 14 , 7 %) . While the fourth group considered as control group which had been administrated tab water . For ( 45 ) days each group had been killed for hormonal assay in blood
... Show MorePbxCd1-xSe compound with different Pb percentage (i.e. X=0,
0.025, 0.050, 0.075, and 0.1) were prepared successfully. Thin films
were deposited by thermal evaporation on glass substrates at film
thickness (126) nm. The optical measurements indicated that
PbxCd1-xSe films have direct optical energy gap. The value of the
energy gap decreases with the increase of Pb content from 1.78 eV to
1.49 eV.
Expansive soils are recognized by their swelling potential upon wetting due to the existence of some clay minerals such as montmorillonite. An effective solution was found to avoid the danger of such soils by using piles. A single pile embedded in an elasto-plastic expansive soil has been analyzed by using one of the available software which is ABAQUS to investigate the effect of applied loads on pile’s top and investigate the effect of swelling soils on load carrying capacity of the pile. The result shows that as the pile is axially loaded at its top, the axial force along the pile gradually changes from (tension) to (compression) and the pile tends to move downward. The applied load needed to initiate pile’s settlement depend
... Show MoreThis work was conducted to study the oxidation of phenol in aqueous solution using copper based catalyst with zinc as promoter and different carrier, i.e. γ-Alumina and silica. These catalysts were prepared by impregnation method.
The effect of catalyst composition, pH (5.6-9), phenol to catalyst concentration ratio (2-0.5), air feed rate (30-50) ml/s, stirring speed (400-800) rpm, and temperature (80-100) °C were examined in order to find the best conditions for phenol conversion.
The best operating conditions which lead to maximum phenol conversion (73.1%) are : 7.5 pH, 4/6 phenol to catalyst concentration, 40 ml/s air feed rate, 600 rpm stirring speed, and 100 °C reaction temperature. The reaction involved an induction period
The purpose of this research highlight the achievement of the effectiveness of small and medium enterprises dimensions and conformable to analyze the relationship between business strategies and human resources management strategies , and launched search of a dilemma thought provoking fundamental questions revolve around the search is the lack of appropriate strategies in these enterprises to help them continuity and permanence in business and markets , as these enterprises lack the human resources management strategies appropriate , as well as business strategies that make them withstand the changes in the market environment is changing and volatile . It was to
... Show MoreThis research tries to reveal how to manage and control the competitive edge for business by building managerial skills in various organizational levels. Our research aims at finding out the nature of various technical, human and in tellectual skills of a new president whose superiority is his competitive ness in the application field at general company for construe tioual industriesand testing the surveyed minor and major changes through a questionnaire to collect information from officials. The sample was composed of (45) director. The data was analyzed using some methods and statistical programs. The most prominent of these is (SPSS) that was used to extract the arithmetic mean, standard deviation, correlation coefficient
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