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.
Diffraction patterns formed by a ferronematic sample, which contains 4-(trans-4-n-hexylcyclohexyl)-isothiocyanatobenzene (6CHBT) liquid crystal doped with Fe3O4 rodlike magnetic nanoparticles, was studied. The studied mixture can be applicated as a liquid magnetic switch. The diffraction patterns were observed from the micro-lines scribed on the polymer layer, which was contained by the liquid crystal mixture cell, with dimensions of 4 nm for depth and 0.32 µm for width and 5000 line per 1 mm2 in the case of absence and presence of the DC magnetic field. From the experimental results, it was observed that the application of the magnetic field caused more than 17% expansion in the diffraction patterns a
... Show MoreThis paper study two stratified quantile regression models of the marginal and the conditional varieties. We estimate the quantile functions of these models by using two nonparametric methods of smoothing spline (B-spline) and kernel regression (Nadaraya-Watson). The estimates can be obtained by solve nonparametric quantile regression problem which means minimizing the quantile regression objective functions and using the approach of varying coefficient models. The main goal is discussing the comparison between the estimators of the two nonparametric methods and adopting the best one between them
The art of calligraphy is regarded as one of the tremendous and distinct products in the history of Islamic arts through the unparalleled high ranks it reached to, until it gained Islam's indication and became a symbol for it, in terms of its function linked to the calligraphy of the holy Qur'anic texts, where this merit formed a strong impulse in seeking its development, the emergence of the calligraphic constructs, including the calligraphic straps, is one of this continual seeking products, and an advanced stage at the level of technical and expressive development, and also one of the natural results generated by the development of fonts and the increase of their employing methods through what they recorded at the level of formal char
... Show MoreObjectives: To choose the best mode of delivery
for term, frank or complete, breech presentation
through studying the perinatal outcome of each mode of
delivery decided when managing a group of pregnant
ladies presented with breech delivery in our centre.
Methods: One hundred and fifty pregnant ladies
presented at term with singleton, frank or complete,
breech presentation for delivery in our centre during the
period from May 2004 toAugust 2005.
Mode of delivery, parity, gestational age, maternal age,
maternal medical illness, and birth weight where the
variables that have been tested in each delivery
included in the study to verify their relationship to
perinatal outcome.
Results: No significant
The recent escalation in Southeast Asia showed that the region is on the verge of political and economic crises through the United States and its allies imposing economic sanctions against China, and a military escalation that may begin with China’s invasion of Taiwan, especially since two-thirds of the American forces in the world are located in the Taiwan Strait and the South China Sea.
The United States claims that it is ready to defend the island of Taiwan in the event of the start of Chinese military operations, but the reality shows that the United States supports Taiwan militarily by equipping it with modern weapons to defend itself. Supporting Taiwan economically by engaging it in trade agreements with US allies in the r
... Show MoreThree hundred and fifty five patients with hepatitis were investigated in this study all cases gave negative result with HBs Ag , IgM-anti HCV , IgM-anti HEV, IgM-anti HDV and anti-HIV tests . The frequency of IgM-anti HAV was 113 and the percentage was 32 % in all ages but when these patients divided into five groups dependent on ages. The highest percentage of IgM-anti HAV was (45%) in age <10 and the percentage declined with age increase till to 9% in age >41 year.
Scenes of love constitute a large space within the orbit of the movies, so that there is almost no film (no matter what kind) void of these scenes, as they are associated with many dimensions and they constitute a major attraction for viewers, and thus the direction solutions and their connection to the director's vision constitute a large part in the process of employing signs to highlight what should be highlighted or to refer to it symbolically on the grounds that the director does not have full freedom in the transfer of scenes of love at all levels as they are in reality. The research included three sections within the theoretical framework:The first section: the concept of image and its rhetorical importance. This section discussed
... Show MoreAbstract:
The aim of the research is to demonstrate the impact of the professional specialization of the audit companies in the detection of fraud in the financial statements of the economic units listed in the Iraqi market for securities for the period 2014-2015 through the application of the model (Carcello) to test the hypothesis of research on the impact of professional specialization of audit companies in the detection of fraud in lists The effect of the variables was revealed through the use of statistical models of logistic regression model and correlation coefficient. After testing the hypotheses of the research, a number of conclusions were reached. The most important was the existence of a signi
... Show MoreThe research aims to identify the reality of the management strategy followed in the treatment of solid waste in the city of Baquba, and what strategies are used to treat solid waste, and the extent of the application of these strategies, through personal interviews with leading cadres in the Directorate of Baquba Municipality, their assistants and heads of departments, they numbered (55) Individuals. The descriptive method was adopted through a questionnaire prepared to measure the extent of the implementation of the strategy of solid waste management in the city of Baquba and using statistical tools including (arithmetic mean, standard deviation, relative importance, the gap). The research reac
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