Stereo lithography (SLA) three-dimensional (3D) printing process is a type of additive manufacturing techniques that uses digital models from computer-aided design to automatically produce customized 3D objects. Around 30 years, it has been widely utilized in the manufacturing, design, engineering, industrial sectors and its applications in dentistry for manufacturing prosthodontics are very important. The stereo lithography technology is highly regarded because it can produce items with excellent precision especially when selecting the best process parameters. This review article offers a useful and scientific summary of SLA three-dimensional printing technology and its brief history. The specific type of 3D printers which is SLA type based on light curing resin and material overview is also presented. Moreover, the survey was conducted to gain substantial knowledge of the various advantages and disadvantages of SLA 3D printing. According to this study, a summary has been specified on the accuracy of SLA 3D printers and various factors that affected its accuracy and dimension measurement namely layer thickness, normal exposure time, bottom or top exposure time, post processing and room temperature. The majority of works in the literatures conducted till date are on improving the physical part attributes like dimensional accuracy and surface roughness but the improving of the mechanical properties have received less attention and need more focusing in the future works.
Ab – initio restricted Hartree - Fock method within the framework of large unit cell (LUC) formalism is used to investigate the electronic structure of Si and Ge nanocrystals. The surface and core properties are investigated. A large unit cell of 8 atoms is used in the present analysis. Cohesive energy, energy gap, conduction and valence band widths are obtained from the electronic structure calculations. The results are compared with available experimental data and theoretical results of other investigators. The calculated lattice constant is found to be slightly larger than the corresponding experimental value because we use only 8 atoms and we compared the results with that of the bulk crystals, nanoclusters are expected to have str
... Show MoreThe treatment of migraine headache targets the neurovascular mechanism and involves the use of serotonin receptor antagonists. Some of these drugs are used for the treatment of acute attacks; while others are effective as prophylactic measures to decrease the duration and frequency of attacks. Pizotifen, a 5-HTA antagonist, is one of the prophylactic drugs for which the clinical use resulted in low outcomes in reducing migraine symptoms. Melatonin, a serotonin derived neurohormone, was reported to exert many functions like sleep induction, anti-inflammatory, neurovascular regulation, cytoprotection and modulation of neurotransmitter release. In the view of the involvement of serotonin in the pathophysiology of migraine a
... Show MoreDetermination of the level of adipokines (obestatin, vaspin, tumor necrosis factor-? and interleukin-6)in hypo-and hyperthyroid patients from Educational Baghdad Hospital in Baghdad City was investigated. Fifty patients with hypothyroidism and Fifty patients with hyperthyroidism were selected. A control group of thirty euthyroid persons was included. Blood was collected by vein puncture and serum was separated and stored at –20C. Adipokines (obestatin, vaspin, tumor necrosis factor-? and interleukin-6) were estimated using ELISA method. The findings show a significant (p<0.05) increase in obestatin level in hypothyroid patients, while there is no significant difference in hyperthyroid patientsas compared with the euthyroid subjects.
... Show MoreThe aim of the research is to identify the percentage of success and failure of some compound offensive skills in joiner basketball. It was evident that development only occurred though the mastery of the basic single offence skills as well as the ability to perform compound skills accurately and consistently. Not paying enough attention to compound skills leads evidentially to weakness in the athlete's level that in turn leads to mistakes in performance. Six joiner games of the best four teams in Baghdad were filmed and analyzed. The results of analyzing the compound offence skills were as follows: There was some weakness in the athletes' ability in using compound offence skills specially receiving, dribbling and following through that
... Show MoreBackground: The microbial production of substances that have the potency to suppress the growth of other microorganisms is probably one of the prevalent defense strategy developed in nature, microorganisms produce a variable bunch of microbial defense systems, which include antibiotics, metabolic by-products, lytic agents, bacteriocins and others. Objective: The purpose of the present study was to isolate and identify Enterococcus faecium isolates then detecting its ability of carrying the gene responsible for enterocin production in this species. Materials and methods: Out of 50 samples from different sources (food and clinical sources) were collected for the Enterococcus faecium isolation, and the isolated bacteria Enterococ
... Show MoreThe present study is an academic attempt to show how the threeUmayyad poets ; Jarir ,
Al-Farazdaq and Al-Akhtal have skillfully employed old conventions and traditions in their
poetry to serve a dual purpose of making their ideas striking , memorable and compelling and
of reaching eminence as poets.
The primary aim of the poets has been to amuse , convince and influence the readers or
listeners of their poetry . as it were, a mirror image of the social , religious and historical
beliefs , values and customs which prevailed throughout the ages before the emergence.
To approach the problem of individual oppression with an international perspective drawing on Foucauldian concepts, this paper compares George Orwell’s 1984 (1949) and the Iraqi Sinan Antoon’s I’jaam (2004), which was translated into English in 2007. Even though Orwell and Antoon come from dissimilar cultural backgrounds, religions and epochs, they have tackled the issue of individuals’ oppression through their oppressed characters in a strikingly similar way. Hence, by applying the theories of both the American School of Comparative Literature and Foucauldian concepts, the current study attempts to establish a relationship between the Western and Eastern ways of dealing with the issue of oppression as an international problem in au
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