Background: Porcelain veneers are under a great deal of stress which may lead to clinical failure as fracture or dettachment. This study examined whether different finishing lines and lingual shoulder preparations in the incisal area of the maxillary central incisor affect the bond of the porcelain veneers. Materials and methods: A two- dimensional finite element model was made. Location and magnitude of maximum Von Mises stresses were calculated in porcelain veneer. Six types of preparations were drawn as:incisal overlap of 0.5mm, 1mm and 1.5mm depth and lingual shoulder, and incisal overlap of 0.5mm, 1mm and 1.5mm depth without shoulder preparation. Results: Stress formation is maximum in the incisal edge region. All the lingual shoulder preparations presented better stress distribution than the non shoulder preparations Conclusion: Stress is distributed more evenly when the tested preparation possesses a good thickness of porcelain and the more the surface area with incisal overlap the less possibility of bond failure.
The current research aims to evaluate the activities and evaluation questions implied in the content of the computer textbook for the fifth preparatory grade according to the creative thinking and developing suggestions through answering the following question: what is the percentage of creative thinking skills in the content of the computer textbook for the fifth Preparatory grade students issued by the Iraqi Ministry of Education/ Directorate General of the curriculum in the academic year (2019-2020)? The researchers followed the descriptive-analytical approach. The research community was determined by the content of the computer textbook for the fifth preparatory grade. As for the research sample, it was limited to all activitie
... Show MoreIn this paper, the system of the power plant has been investigated as a special type of industrial systems, which has a significant role in improving societies since the electrical energy has entered all kinds of industries, and it is considered as the artery of modern life.
The aim of this research is to construct a programming system, which could be used to identify the most important failure modes that are occur in a steam type of power plants. Also the effects and reasons of each failure mode could be analyzed through the usage of this programming system reaching to the basic events (main reasons) that causing each failure mode. The construction of this system for FMEA is dependi
... Show MoreThis research aims to the possibility of evaluating the strategic performance of the State Board for Antiquities and Heritage (SBAH) using a balanced scorecard of four criteria (Financial, Customers, Internal Processes, and Learning and Growth). The main challenge was that the State Board use traditional evaluation in measuring employee performance, activities, and projects. Case study and field interviews methodology has been adopted in this research with a sample consisting of the Chairman of the State Board, 6 General Managers, and 7 Department Managers who are involved in evaluating the strategic performance and deciding the suitable answers on the checklists to analyze it ac
... Show MoreThis research aims to the possibility of evaluating the strategic performance of the State Board for Antiquities and Heritage (SBAH) using a balanced scorecard of four criteria (Financial, Customers, Internal Processes, and Learning and Growth). The main challenge was that the State Board use traditional evaluation in measuring employee performance, activities, and projects. Case study and field interviews methodology has been adopted in this research with a sample consisting of the Chairman of the State Board, 6 General Managers, and 7 Department Managers who are involved in evaluating the strategic performance and deciding the suitable answers on the checklists to analyze it according to the 7-points Likert scale. Data analysis re
... Show MoreCalcium carbonate is predominantly present in aqueous systems, which is
commonly used in industrial processes. It has inverse solubility characteristics
resulting in the deposition of scale on heat transfer surface. This paper focuses on
developing methods for inhibition of calcium carbonate scale formation in cooling
tower and air cooler system where scaling can cause serious problems, ZnCl 2 and ZnI
2 has been investigated as scale inhibitor on AISI 316 and 304. ZnCl 2 were more
effective than ZnI 2 in both systems, and AISI 316 show more receptivity to the
chlorides salt compared to AISI 304. The inhibitors were more effective in cooling
tower than air cooler system. AISI 316 show more constant inhibition effic
The experiment was conducted in the old botanical garden belong to Biology Department/ College of Education for Pure Science - Ibn Al-Haitham/Baghdad University for growing season 2015-2016 to study the effect of irrigation with four concentrations of sodium chloride (0, 50, 100, 150) mM.L-1 and spraying with selenium in three concentrations (0, 10, 20) mgL-1 on growth of broad bean plant using clay pots. The experiment was design according to completely randomized design (CRD) with three replications. Results indicated that broad bean plant irrigated with saline water and increasing concentrations of sodium chloride in growth medium caused a significant decreased in the plant growth parameters (plant height, no. of compound leaves. Plant-1
... Show MoreTo determine the association between cigarette smoking and oxidative stress, a study was conducted in the period from January 2020 to April 2021, at College of Medicine, Al-Nahrain University, Baghdad, Iraq. The Enzyme-linked immunosorbent assay (ELISA) technique was utilized for measurement the antioxidant enzymes including: Glutathione superoxide (GPX) and catalase (CAT) and the biomarker of lipid peroxidation Malondialdehyde (MDA). Also, the gene expression of Nrf2 and HO-1were determined by using RT-PCR technique. The results indicate lower level of both GPX and CAT (p ≤ 0.001) in smokers compared with non-smokers. While the result of MDA indicate higher level in smokers (p≤0.001) compared with nonsmokers. The Nrf2 and HO-1 gene exp
... Show MoreThe current research aims to identify the fear of intimacy and post-traumatic stress disorder among Yazidi women and the correlation between them. To achieve the objectives of the research, the researcher adopted the Descutner, 1991 & (Thelen) scale, which consisted of (35) items. The researcher also adopted the post-traumatic stress disorder scale for (Davidson, 1995) translated by (Abdul Aziz Thabet), which consists of (17) items. These two scales were administered to a sample of (200) individuals. Then, the researcher analyzes the data using the Statistical Package for Social Sciences (SPSS). The results showed that the research sample of Yazidi women has a fear of intimacy. The research sample of Yazidi women is characterized by
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