ABSTRACT Background:Hydrogen absorption and related degradation in the mechanical properties of Ni-Ti based orthodontic wires has been demonstrated following exposure to fluoride prophylactic agents. This study was designed to investigate the effects of three fluoride containing agents on the load deflection characteristics of heat activated nickel titanium arch wires during unloading phase. Material and method: Eighty specimens of heat activated nickel titanium arch wires were obtained from Ortho Technology Company, half of which had a 0.016 inch round and 0.019x0.025 rectangular. Ten specimens from both wire size were immersed in one of the tested fluoride prophylactic agents (neutral sodium fluoride gel, stannous fluoride gel or phos-flur mouth rinse) or in the controlled medium “normal salineâ€, and incubated at 37ËšC for sixty minutes. A Wp 300 universal material testing machine was modified and used to perform a three point bending test in a water path at 37ËšC ±1ËšC.The statistical difference between the different agents were analyzed using ANOVA and LSD tests. Results: The unloading forces at 0.5, 1.0, and 1.5 mm where significantly reduced especially in neutral sodium fluoride treated specimens. Conclusion: Based on the results founded in th study it might be preferred to use prophylactic agent with the least fluoride ions concentration.It can be concluded that the tested agents have only a limited effect on the load deflection behavior of the heat activated Ni-Ti wires, in a way that they do not have a clinically significant effect on the mechanical behavior of these wires.
В статье рассматриваются понятие наглядности и ее классификация, эффективное применение принципа наглядности, возможность и преимущество использования наглядности и современные инструменты ее реализации в ираке.
Вследствие глобальных изменений во всем мире изменилась и роль иностранного языка в системе образования. Современный человек, шагающий в ногу со временем, не мыслит себя без зна
... Show MoreRestoration of degraded lands by adoption of recommended conservation management practices can rehabilitate watersheds and lead to improving soil and water quality. The objective was to evaluate the effects of grass buffers (GBs), biomass crops (BCs), grass waterways (GWWs), agroforestry buffers (ABs), landscape positions, and distance from tree base for AB treatment on soil quality compared with row crop (RC) (corn [
In addition to being a religious book with high human and moral themes, Nahj al-Balagha is considered a mirror of Arab culture and a literary masterpiece at the height of eloquence and eloquence, and because proverbs in the form of short, concrete and understandable phrases for everyone, experiences, thoughts and convey ideas, Imam Ali (AS) used it to facilitate the understanding of various political, social and moral concepts. In this article, we intend to criticize the way Dashti, Shahidi and Foladvand translated it by using Newmark's model due to the importance and cultural reflections of proverbs in understanding the cultural atmosphere governing Nahj al-Balagheh. In his evaluation model, Newmark divides cult
... Show MoreGod created man with a social nature, that is, man cannot live alone, but there must be a society associated with him. And when God addressed Adam, the first of His creation, he addressed him with the speech of the Muthanna to him and his wife. “This tree, then you will be among the wrongdoers” (Al-Baqara: 35), and thus was the divine discourse for the first human experience on earth. It accommodates a social relationship, which is (the family), husband and wife. And since a person needs to meet, as Ibn Khaldun said: (The human meeting is necessary, and the wise men express this by saying (the human being is of course civil)) (). And as it is known that with the meeting, relations arise from love and hate, cooperation and struggle, a
... Show MoreIn the last few years, the use of artificial neural network analysis has increased, particularly, in geotechnical engineering problems and has demonstrated some success. In this research, artificial neural network analysis endeavors to predict the relationship between physical and mechanical properties of Baghdad soil by making different trials between standard penetration test, liquid limit, plastic limit, plasticity index, cohesion, angle of internal friction, and bearing capacity. The analysis revealed that the changes in natural water content and plastic limit have a great effect on the cohesion of soil and the angle of internal friction, respectively. . On the other hand, the liquid limit has a great impact on the bearing capacity and
... Show MoreIn the last few years, the use of artificial neural network analysis has increased, particularly, in geotechnical engineering problems and has demonstrated some success. In this research, artificial neural network analysis endeavors to predict the relationship between physical and mechanical properties of Baghdad soil by making different trials between standard penetration test, liquid limit, plastic limit, plasticity index, cohesion, angle of internal friction, and bearing capacity. The analysis revealed that the changes in natural water content and plastic limit have a great effect on the cohesion of soil and the angle of internal friction, respectively. . On the other hand, the liquid limit has a great impact on the bearing capacity and
... Show MoreIn the last few years, the use of artificial neural network analysis has increased, particularly, in geotechnical engineering problems and has demonstrated some success. In this research, artificial neural network analysis endeavors to predict the relationship between physical and mechanical properties of Baghdad soil by making different trials between standard penetration test, liquid limit, plastic limit, plasticity index, cohesion, angle of internal friction, and bearing capacity. The analysis revealed that the changes in natural water content and plastic limit have a great effect on the cohesion of soil and the angle of internal friction, respectively. . On the other hand, the liquid limit has a great impact on the bearing capacity and
... Show MoreTraumatic spinal cord injury is a serious neurological disorder. Patients experience a plethora of symptoms that can be attributed to the nerve fiber tracts that are compromised. This includes limb weakness, sensory impairment, and truncal instability, as well as a variety of autonomic abnormalities. This article will discuss how machine learning classification can be used to characterize the initial impairment and subsequent recovery of electromyography signals in an non-human primate model of traumatic spinal cord injury. The ultimate objective is to identify potential treatments for traumatic spinal cord injury. This work focuses specifically on finding a suitable classifier that differentiates between two distinct experimental
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