Background: Nickel-titanium (NiTi) archwires have become increasingly popular because of their ability to release constant light forces, which are especially useful during initial alignment and leveling phase. The aim of the present study was to investigate and compare the load–deflection characteristics of four commercially available NiTi archwires. Materials and methods: 200 NiTi 0.014, 0.016, 0.018, 0.016x0.022 and 0.019x0.025-inch nickel–titanium archwires from four different manufacturers (3M, Ortho Technology, Jiscop and Astar) were tested. The load-deflection properties of these archwires were evaluated by a full arch bending test in both palatal and gingival directionsat 37°C temperature using a universal material testing machine. Forces generated at maximumloading of 2mm and at unloading of 1.5mm were measured. Results: All the tested NiTi wires showed an increase in loading and unloading force with increased wire dimension.Generally, 3M gave the most flexible round wires and relatively stiff rectangular wires; with linear load deflection curves. Ortho Technology wires were flexible. Jiscop gave the stiffest round wires and the most flexible rectangular wires. Astar wires were stiff which gave the highest force levels during unloading. Conclusion: Force levels vary greatly from brand to brand and soNiTi wire brands must be selected with consideration to their load-deflection characteristics and mechanical properties.
In this study, gold nanoparticles (AuNPs) were synthesized using a plasma jet system at different exposure times. Using ultraviolet, visible spectra, X-ray diffraction, the nanoparticles were characterized (XRD). A Plasmon surface resonance concentrated at 530, 540, and 533 nm for the prepared AuNPs. The pattern of XRD showed that the extreme peaks of the film reflect crystalline existence. The face-centered cubic structure of the gold nanoparticles was prepared for all samples, with an average crystallite size of 25-40 nm. The effect of AuNPs in vivo on liver function levels was measured. For all doses, we notice an increase in the ranks of liver function in the blood during the period of dosing, and it begins to decrease when the dosi
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Been using a pv system program to determine the solar window for Baghdad city . the solar window for any location can be determine by deviating left and right from the geographical south as well as deviation according to the amount of tilt angle with the horizon for fixed panel so that will not change the average of solar radiation incident over the whole year and this lead to help in the process of installation of fixed solar panel without any effect on annual output .the range of solar window for Baghdad city between two angles ( -8 - +8 ) degrees left to right of the geographical south and tilt angle that allowed for the horizon range between angles (21- 30) degrees so that the amount of solar radiation that falling on the solar pan
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In this study, plain concrete simply supported beams subjected to two points loading were analyzed for the flexure. The numerical model of the beam was constructed in the meso-scale representation of concrete as a two phasic material (aggregate, and mortar). The fracture process of the concrete beams under loading was investigated in the laboratory as well as by the numerical models. The Extended Finite Element Method (XFEM) was employed for the treatment of the discontinuities that appeared during the fracture process in concrete. Finite element method with the feature standard/explicitlywas utilized for the numerical analysis. Aggregate particles were assumedof elliptic shape. Other properties such as grading and sizes of the aggr
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In the present work a dynamic analysis technique have been developed to investigate and characterize the quantity of elastic module degradation of cracked cantilever plates due to presence of a defect such as surface of internal crack under free vibration. A new generalized technique represents the first step in developing a health monitoring system, the effects of such defects on the modal frequencies has been the main key quantifying the elasticity modulii due to presence any type of un-visible defect. In this paper the finite element method has been used to determine the free vibration characteristics for cracked cantilever plate (internal flaws), this present work achieved by different position of crack. Stiffness re
... Show MoreBackground: Fiber-optic endoscopy is an important
investigation of the large intestine, whether or not the
radiologist (barium enema) has discovered a lesion in
the bowel. Colonoscopy affords a unique opportunity
to direct visualization of entire colonic mucosa. At
the same time, the physician can obtain biopsy specimens, remove polyps, and decompress volvuli.
Most experienced endoscopists and well prepared
patients can reach the cecum in over 90% of patients.
If colonoscopy is properly performed, it has a low
risk of complications, such as perforation and bleeding.
Methods: A total of 70 consecutive patients admitted
to Endoscopy department at Al-Kindy Teaching hospital from September- 2008 to July-2009.
The research problem lies in the fundamental questions that revolve around the role of each of the tools of promotion, namely advertising, personal sale, public relations, sales promotion, and direct marketing in achieving leadership for business organizations. Research to know the role of promoting the service in the researched company and whether the promotion of the service is qualified to lead the researched company to leadership, and for this purpose formulated research hypotheses of three hypotheses, the first hypothesis says that there is a significant impact relationship between promotion and entrepreneurship. The second hypothesis aimed to determine the role played by promotion in the researched company to achieve unique
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Objective: The evaluation of serum osteocalcin (OSN) for Iraqi infertile patients to see the effect of osteocalcin insufficiency, which may lead to a decreased level of testosterone production in males that may cause infertility. Methods: Forty two newly diagnosed infertile males age range (24–47) years and thirty two apparently healthy males as controls age range (25–58) years. Serum levels of testosterone (TEST), stimulating follicle hormone (FSH) and luteinizing hormone (LH), prolactin (PROL), osteocalcin OSN, and fasting blood sugar (FBS) were performed in both patients and controls. Estimation of serum OSN by Immulite1000 auto-analyzer, TEST, FSH, LH, PROL, and FBS by Immulite2000 auto-analyzer. Results: Infertile patients
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