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.
The importance of research and study of classical Persian literature is not overlooked. So far, there have been many studies in this area. But there are still some things that need more research. Persian grammar is one of the most important branches of Persian literature. This section has always been converted at different times. One of the issues that has been neglected in the studies of classical literature is the study of the technical tales of past and past poetry. These texts can be studied from different perspectives. Because Persian is a mixed language, it is possible to combine language terms with each other or to add prefixes and suffixes to express new concepts. They can be used by exam
... Show More
The removal of SO2 from simulated gas stream (SO2 + air) in a fixed bed reactor using Modified Activated Carbon (MAC) catalysts was investigated. All the experiments were conducted at atmospheric pressure, initial SO2 concentration of 2500 ppm and bed temperature of 90oC. MAC was prepared by loading a series of nickel and copper oxides 1, 3, 5, 7, and 10 w
... Show MoreThe grain hardness, wet and dry gluten contents, protein and ash contents are determined in grains from different cultivars of wheat which are important in food products, either which are present in raw materials or in final products. Wheat is also a very important food raw material, and flour as the final product of milling. The importance of knowing the physical and chemical properties of wheat and flour is due to the determination of quality and kind of flour which is produced after the milling process. In this work, some physical and chemical properties of different wheat cultivars are determined and the comparisons of these characteristics are performed in both wheat and flour. Uruq Wheat sample (W5) has the highest results when compar
... Show MoreThis study aims to test whether the institutions listed on the Iraq Stock Exchange have a significant correlation between the level of conservative accounting practice with the level of market share returns during the Coronavirus pandemic period as one of the policies to confront the economic repercussions of the Coronavirus pandemic. Furthermore, the sample included institutions listed on the Iraq Stock Exchange during the 2019 and 2020 years, i.e., the period before the Coronavirus pandemic and during the Coronavirus pandemic for the purpose of comparison. The market value to book value model was used, and the study found that conservative institutions had achieved the highest level of market share prices compared to non-conservat
... Show MoreThe adrenal gland is a vital endocrine gland that secretes many important hormones in the daily life of birds. It is located in the Iraqi Pterocles alchata bird on both sides of the aorta in the front and side of the cranial lobe of the kidney at the caudal end of the lungs, triangular shape with a creamy yellow color. The statistical analysis showed no significant differences between the weight and length of the right and left glands. Histologically the gland of the sandgrouse bird capsule contains autonomic nodes consisting of nerve cells and the average thickness of the capsule is 42.69±1.81μm, the parenchyma of the gland is divided into two areas; the cortex and medulla in addition to the blood sinuses. The cortex area is divided into
... Show MoreIn the contemporary political history of Iraq, a unique protest broke out on October 1st, 2019. This protest reappeared on October 25th and lasted up to the following weeks making this protest as the most comprehensive and deepest one. It has the possibility of lengthening and the diversification of methods among all the social protesting movements during the century for Iraq. This desperate youth movement presents various images and methods to highlight the image of the protesting movement. The role of the Iraqi woman was clear, which was embodied through the mural paintings expressing her artistic and social role in conveying and expressing the goal of the protest. The aim of the current research is to identify the social artistic implica
... Show MoreThis study aimed to show the extent of compliance with the income taxpayer to provide tax returns and increase the speed of collection of these taxes in addition to increasing confidence in Income Tax department and reduce the number of cases transferred to the courts and promote taxpayer awareness in charge of the importance of self-assessment system, and study sought to investigate the effect of the existence of records documents, technical audit, and computational audit and documentary audit on income tax collections in Jordan, from the point of viewof Jordanian income tax auditors ,results shows there's a strong relation between these variables and Income Tax collections.
A comparative study was carried out on ecological and genetical adaptation of three Iraqi
freshwater snails, Physa acuta, Melanopsis buccinoidea and Melanoides tuberculata, in
respect to acute toxicity of heavy metals (Zn, Cd and Hg). Longevity are used as poisoning
tolerance criterion. LT 50 and LT 100 were determined for the studied snails at (0.5, 1, 5, and
10 ppm), for the three metals. Results indicated that Physa acuta had a higher tolerance than
Melanopsis buccinoidea and Melanoides tuberculata, which was the lower one. Previous
exposure to heavy metals in the original habitat was affecting on experimental tolerance and
no relationships of physical and chemical factors (total hardness, temperature, D. O. and
E-learning is a lifeline for the educational process, which contributed to the sustainability of working educational organizations and prevented them from stopping, so the study came to measure the compatibility between E-learning quality dimensions (information technology, educational curricula, teaching methods, and intellectual capital of educational institution) as an independent variable, and educational services quality dimensions represented by (safety, tangibility, reliability and Confidence) as a dependent variable. The sample was 150 teachers was drawn from the College of Administration and Economics community of 293 teachers through the use of several statistical methods to measure the degree of correlation and impact between the
... Show More