Background: Alginate impression material is the irreversible hydrocolloid material that is widely used in dentistry. The contact time between alginate and gypsum cast could have a detrimental effect on the properties of the gypsum cast. The objective of this study is to evaluate the impact of various contact time intervals of Alginate impressions & type III dental stone on surface properties of stone cast. Materials and Methods: Time intervals tested were 1hour, 6 hours and 9 hours. Surface properties of stone cast evaluated were surface detail reproduction, hardness and roughness. Surface detail reproduction was determined using cylindrical brass test block in accordance with ISO 1563. Surface roughness was measured by profilometer and hardness was measured by Durometer (Shore D). Results: The detail reproduction showed significant difference (P<0.05), at 6 hr., and 9 hr. showed better results. While surface roughness significantly decreased (p<0.01) with prolonged contact time. However, surface hardness increased significantly (p<0.01) with increased contact time. Conclusions: Surface detail reproduction increased with increasing the contact time and this was noticed at (6, 9 hours). However, 1hour time interval showed decreased surface detailed reproduction. Roughness decreased when the contact time was increased between type III dental stone and alginate impression whereas, hardness was improved significantly with increasing contact time.
This paper reflects the evidence of the Islamic Development Bank's role in building human and institutional capacities in Member States and assisting governments in achieving economic development. The Bank's activities in the area of capacity development are an important part in following up the economic developments, And help governments to build and formulate effective policies and institutions to implement more effective macro policies leading to better economic outcomes. It is therefore helpful to help Member States increase their resources, modernize their banking systems, establish effective legal frameworks and improve Reports on macroeconomic and financial statistics. The Bank has faced many challenges and risks tha
... Show MoreIraq has the second largest proven oil reserves in the world. According to oil experts, it is expected that the Iraq's reserves to rise to 200+ billion barrels of high-grade crude.
Oil is a strategic commodity for producing and exporting countries in general, and Iraq in particular, as demonstrated by the international experience that oil is an important means to achieve economic growth, an important tool in the overall economic, social and political development. It is also an important source of hard currency for any national economy and a means to connect the local economy and the global economy. In this paper we focus our attention on selecting the best regression model that explain the effect of human capita
... Show MoreBackground: Orthodontic force is considered to stimulate cells in the periodontium to release many mediators such as cytokines which play a responsible role for periodontal and alveolar bone remodeling, bone resorption and new bone deposition. Aim of this study was carried out to estimate changes of the (interleukin-one beta, tumor necrosis factor – alpha and C-reactive protein) levels in unstimulated whole saliva during the leveling stage of orthodontic tooth movement. Materials and methods: The sample consisted of thirty adult patients (12 males and 18 females) with ages ranges (19-23) years. Each sample had Class I and Class II malocclusion dental classification and required bilateral extraction of their maxillary first premolars, und
... Show MoreProduction of the steroidal saponin digitonin in multiplied shoots of Digitalis purpurea , (var. Excelsior Mixed) has been achieved in vitro by two experiments. In the experiment 1, shoot tips ( 1cm length ) explants from the sterilized seedlings were excised and cultured on MS medium ( Murashige and Skoog medium) supplemented with 0.5 mg/L TDZ (thidiazuron) and cholesterol at the concentrations 0.0, 0.1, 0.3, 0.5, 1.0, 1.5, 2.0 or 4.0 mg/L. After 45 day, results showed that the treatment with 0.5 mg/L TDZ and 2.0mg/L cholesterol had a positive effected on increasing the dry weight of multiplied shoots and their production of digitonin when compared with other treatments, where this treatment gave 2
... Show MoreObliquely deposited (70o) Bi, Sb, and Bi-Sb alloy thin films have been prepared by thermal
resistive technique. Structural properties of these films were studied using XRD. Their resistance and
voltage responsivity for Nd:YAG and CO2 laser pulses have been recorded as function of operating
temperature between 10 oC and 120 oC. It was found that the maximum responsivity for these detectors
can be obtained at 75 oC. On the other hand, the dependence of responsivity on the width of detectors was
investigated.
Some structures such as tall buildings, offshore platforms, and bridge bents are subjected to lateral loads of considerable magnitude due to wind and wave actions, ship impacts, or high-speed vehicles. Significant torsional forces can be transferred to the foundation piles by virtue of eccentric lateral loading. The testing program of this study includes one group consists of 3 piles, four percentages of allowable vertical load were used (0%, 25%, 50%, and 100%) with two L/D ratios 20 and 30, vertical allowable load 110 N for L/D = 20 and 156 N for L/D = 30. The results obtained indicate that the torsional capacity for pile group increases with increasing the percentage of allowable vertical load, when the percentage of allowable vertica
... Show MoreIn this search, Ep/SiO2 at (3, 6, 9, 12 %) composites is prepared by hand Lay-up method, to measure the change in the thermal conductivity and Impact Strength of epoxy resin before and after immersion in H2SO4 Solution with a 0.3N for 10 days. The results before immersion decreases with the increase of the weight ratios of the reinforcement material (SiO2), It changed from (82.6×10-2 to 38.7×10-2 W/m.°C) with change weight ratios from (3 to 12) % respectively, but after immersion time in the chemical solution where it was (65.6×10-2 W/m.°C) at the weight ratios (6 %) and became (46.6 × 10-2 W/m.°C) after immersion in sulfuric acid. The results of the Impact strength decreased by increasing the percentage weight ratio, it changed f
... Show MoreThe objective of this research was to study the effect of physical exertion training on bio-kinetic abilities in weightlifting among students of Physical Education and Sports Sciences. The present study had a pre-posttest experimental design in which participants were recruited in two groups: experimental group and control group. A total of 30 students of Physical Education and Sports Sciences constituted the sample of the study. The sample selection was done by a comprehensive inventory method. Participants were equally allocated into two groups with n=15 in each group. Participants of experimental group were made to perform special physical exercises with three training units per week during eight weeks. The statisti
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