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.
In this work, a convex lens concentrating solar collector is designed and manufactured locally by using 10 convex lenses (concentrator) of a diameter 10cm and one Copper absorber tube of a diameter 12.5mm and 1mm in thickness 1m length. Two axes manual Tracking system also constructed to track the sun continuously in two directions. The experiments are made on 17th of May 2015 in climatic conditions of Baghdad. The experimental data are fed to a computer program to solve the thermal performing equation, to find efficiency and actual useful energy. Then this data is used in numerical CFD software for three different absorber diameters (12.5 mm, 18.75 mm and 25 mm). From the results that obtained the maximum the
... Show MoreAtenolol is one of beta-adrenergic receptor blocking agent. It is widely used for the treatment of hypertension as a selective antihypertensive drug. But long term usage of atenolol may cause one of the cardiovascular diseases like myocardial infarction. To prove the relationship between atenolol and cardiovascular disease, measurement of creatinekinase-MB as a diagnostic indicator in early and long term usage of this drug by hypertensive patients is recommended. A comparative study was conducted in Al-Yarmouk Teaching Hospital–Emergency Department- on 30 hypertensive patients using atenolol. They were divided into (2) groups A and B according to the duration of the drug usage. Group A- (15) patients with a mean age (56
... Show MoreSpecial exercises in individual games are an important pillar in learning their basic skills. The aim of the research is to prepare special exercises using tools and their effect on learning the skill of landing with Salto backward tucked to stand - knowing the effect of special exercises using tools and their effect on learning the skill of landing with Salto backward tucked to stand on the horizontal bar. Either the research assumes the existence of significant differences in the pre- and post-tests in learning the skill of landing with Salto backward tucked to stand on the horizontal bar in favor of the post-test. The researchers used the experimental method with a single sample design to suit the research problem, as the researc
... Show MoreBackground: Immediate implant placement in the maxillary anterior region was challenging, especially with the jumping gap and limited primary implant stability. Objective: To assess the autogenous dentin graft biomaterial's ability to improve the esthetic outcomes of an immediately inserted implant. Methods: Twenty patients with non-restorable retained roots in the maxillary non-molar region surrounded by natural sound teeth were included in this study after a complete clinical and radiological examination, including patient health and clinical fitness for the immediate dental implant procedure. A single dental implant was inserted for each patient, and the resulting jump distance was filled with the mineralized dentin graft and co
... Show MoreThe dose rate for bremsstrahlung radiation from beta particles with energy (1.710) MeV and (2.28) MeV which comes from (32P and 90Y) beta source respectively have been calculated through six materials (polyethylene, wood, aluminum, iron, tungsten and lead) for first shielding material with thickness (x=1) mm which are putting between beta sources and second shield (polyethylene, aluminum and lead) with thickness (1, 2 &4) mm have been calculated. The distance between beta source and second shield is constant (D=1) cm. This dose rate was found by program called Rad Pro Calculator (version 3.26). The results of dose rate of beta particles were plotted as a function to the atomic number (Z) for first shield materials for each
... Show MoreAutorías: Mustafa Abdulamir Hussain, Ahmed Sebeaatea Almujamay, Riyadh khaleel khammas. Localización: Revista iberoamericana de psicología del ejercicio y el deporte. Nº. 5, 2022. Artículo de Revista en Dialnet.
The objective of this article is to study the impact of environmental pollution on air, water, and soil quality with a focus on the role of environmental bacteria in bioremediation of pollutants. The research also addresses the ability of some strains of bacteria to remove heavy metals and petroleum hydrocarbons and degrade toxic substances, resulting in improved environmental quality. Outcomes: Empirical studies reveal that environmental pollution leads to significant health and environmental problems, such as a rise in respiratory disease as a result of air pollution, water pollution that affects aquatic life, and soil pollution that decreases crop output. Other bacterial strains such as Pseudomonas, Bacillus, and Streptomyces have also b
... Show MoreThe dose rate for bremsstrahlung radiation from beta particles with energy (1.710) MeV and (2.28) MeV which comes from (32P and 90Y) beta source respectively have been calculated through six materials (polyethylene, wood, aluminum, iron, tungsten and lead) for first shielding material with thickness (x=1) mm which are putting between beta sources and second shield (polyethylene, aluminum and lead) with thickness (1, 2 &4) mm have been calculated. The distance between beta source and second shield is constant (D=1) cm. This dose rate was found by program called Rad Pro Calculator (version 3.26). The results of dose rate of beta particles were plotted as a function to the atomic number (Z) for first shield materials for each
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The aim of the current research is to identify the Effect of the alternative evaluation strategy on the achievement of fourth-grade female students in the subject of biology. The researchers adopted the zero hypothesis to prove the research objectives, which is there is no statistically significant difference at the level (0.05) between the average scores of the experimental group who study according to the alternative evaluation strategy and the average scores of the control group who study in accordance with the traditional method. The researchers selected the experimental partial adjustment design of the experimental and control groups with the post-test. The researchers intentionally selected (Al-fed
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