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.
This paper is a part of a cytological studies of the genus Bromus L. in Iraq . Cl number for 103 specimens ropro^eming l^species determined . The course of meiosis including an analysis of chromosome configuradon for 27 collections belonging to 8 species were investigated . Meiosis was regular in most species . Tetraploid for B.scoparius L. (new cytotype ) and hexaploid ?'or " Kunth. were re^rted for the first time, cytological findings were supported the view of maintaining the closely related species B.danthoniae Trin. and B.lanceolatus Roth, as distinct species .
The agricultural sector suffers from many risks and natural disasters, such as droughts and heavy rains that cause floods, as well as hail and agricultural pests, etc., that threaten agricultural activity and reduce it, which leads to the failure of farmers and peasants for fear of being subjected to continuous losses. Nevertheless, we notice almost complete reluctance to move towards agricultural insurance, due to the dependence of farmers on the government, which adopts the principle of compensation instead of agricultural insurance when natural disasters happen despite the difficulties and financial hardship as well as the suspicion of corruption that haunt the compensation process and this represents the most important problem for resea
... Show MoreIn this research study the synodic month for the moon and their
relationship with the mean anomaly for the moon orbit and date A.D
and for long periods of time (100 years), we was design a computer
program that calculates the period of synodic months, and the
coordinates of the moon at the moment of the new moon with high
accuracy. During the 100 year, there are 1236 period of synodic
months.
We found that the when New Moon occurs near perigee (mean
anomaly = 0°), the length of the synodic month at a minimum.
Similarly, when New Moon occurs near apogee (mean anomaly =
180°), the length of the synodic month reaches a maximum. The
shortest synodic month on 2053 /1/ 16 and lasted (29.27436) days.
The lo
In this study, the effect of pumping power on the conversion efficiency of nonlinear crystal (KTP) was investigated using laser pump-power technique. The results showed that the higher the pumping power values, the greater the conversion efficiency (η) and, as the crystal thickness increases within limitations, the energy conversion efficiency increases at delay time of (0.333 ns) and at room temperature. Efficiency of 80% at length of KTP crystal (L = 1.75 X 10-3 m) and Pin = 28MW, and also, compare the experimental results with numerical results by using MATLAB program.
This included the study of embryonic development of the heart in different lengths of embryos of Sailfin molly (Poecelia latipinna) fish, which is one of the invasive fish species in Iraq and is spread acrosswater bodies, especially in the marshes that are located in the south of Iraq. The fish samples were collected from the AGhazl market in Baghdad province, and dissected to remove the ovary that containing embryos at different lengths using fine forceps. All the samples were fixed using formalin after making a hole in the gas sac, especially in advanced embryos stage. In a 3 mm embryo, the heart was completely formed and the blood vessels and optic cup were clear, while the lens of the eye was beginning to form. In 4-5 mm embryo, it was
... Show MoreThe study of the current study (to the concept of the aesthetics of the imagined in Iraqi ceramics (Saad Shaker) as a model for the study, as it represents one of the most important plastic arts that was characterized by renewal and modernity and its possession of many creative potentials. And by glazing, and the use of color oxides or by the creative act of borrowing the cultural heritage to turn it into a vocal piece of art for creation and innovation.
The researcher (Saad Shaker), being one of the first potters, his ceramics had a lot of development and semantic transmission, studying and decoding codes written in ceramic works. The current study included the theoretical framework in the first research (the philosophical beauty) an
Space is considered as an important element in constructing artwork, it can be a dominant and fulfilled part that adds new existence to the content. Each artwork must have a space artistically or analytically. The internal and eternal space of artwork have associated with each other in order to be ann important connected unit that establishes the work epressions and helps the audience to understand it. Such kind of works can be represented by the works of the potter (Sheinyor Abdu Allah) which have uarious expressions of space which this study is based on.The study aims at finding out the treatment of apace in the ceramic sculpture works of the potter (Sheinyar Abdu Allah).The second chapter has many sections. T
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