Background: The ideal force-delivery system must: provide optimal tooth moving forces that elicit the desired effects, be comfortable and hygienic for the patient, require minimal operator manipulation and patient cooperation and provide rapid tooth movement with minimal mobility during orthodontic therapy, the elastomeric chains have the greatest potential to fulfill these requirements. Materials and Methods: This in vitro study was designed to determine the effect of three different mechanisms for canine retraction : (6-3 , 6-5-3 and chain loop ) on the load relaxation behavior of three types of elastomeric chains : (maximum clear , maximum silver and extreme silver) from the same company (Ortho Technology company) with two different brand configurations: closed loop and open (short filament) chains under effect of time at (zero time, 24hr., 7, 14 , 21 and 28 days) in artificial saliva. Results: Statistical analysis showed that there was a highly significant difference in the mean percentage force decay for the three different mechanisms (P? 0.001).For all the three types, the 6-3 mechanism had the smallest mean percentage force decay. There was a highly significant difference in the mean percentage force decay for the different types (P? 0.001). For all three mechanisms, extreme silver elastomeric chains had the smallest percentage force decay while maximum silver elastomeric chains had the highest percentage force decay. Conclusion: This study illustrated that for all the three types of elastomeric chains, the (6-3) mechanism had the smallest mean percentage force decay. This finding suggests that it may be most efficient to retract a canine utilizing elastomeric chain directly from the molar hook to the canine bracket. The chain loop mechanism may not be indicated for space closure in vivo due to the excessive physiological force values involved with this mechanism.
In this paper we introduce the basic of definitions of groups for geometric figures; we describe some of geometric figures by using the properties of groups. The classification of some geometric figures by using the properties of some algebraic structures.
The research is concerned with the problems of knowledge purification of kindergarten children by verifying its aims, identifying of knowledge purification among the first level of kindergarten children and the second level of kindergarten children, and the differences between the males and females in the variable of knowledge purification. The research community included the children in the state and private kindergartens in Baghdad governorate, on its two sides, Karkh and Rusafa, for the six districts for the academic year 2022-2023. After making the knowledge purification test according to the scientific steps of test constructions, the test has been presented to a group of experts specialized in the field of kindergarten to ascertain
... Show MoreIt has become familiar to see alchemy as a methodological approach that combines conscious, diverse, psychological, social, structural, and discrete approaches in the communications technology that Marshall McLuhan found to be able to extend our bodies and senses, The media discourse has a deep and superficial structure produced by the first, with its social, cultural and historical backgrounds, in a context that connects the image with the word, as the "meanings are made" - everywhere, as described by Jonathan ) In fashion, in the arts as a whole, and from its "signs" Our analysis of «meaning», in the media, and communication through advertising, magazines, newspapers, television, and the Internet. Therefore, alchemy is preoccupied wi
... Show MoreThe researcher found that neglecting our Arab Islamic heritage and bragging about what the West came in the field of education and psychology is common in our curriculum
So the researcher found it necessary to identify the thought of our media Arab Muslims like Ibn Al-Jawzi being a remarkable figure in the world of human thought therefore, the researcher in this research decided to identify his educational and psychological ideas and psychological emotions in his mind and methods of control and characteristics of the human soul and methods of development of the Muslim character by following the descriptive analytical approach.
Shoot tip of Actinidia chinensis plant were excised and sterilized with mercuric chloride (Hgcl2) at concentration 0.1% for 5 min, then cultured on MS medium supplemented with benzeladinine BA at concentration (0.0,0.5,1.0,2.0,2.5) mg/l in multiplication stage Moreover, indole butyric acid IBA at concentration (0.0, 0.5,1.0,2.0,4.0) mg/l and (0.0,0.5,1.0,2.0) mg/l on solid and liquid solution media respectively in rooting stage were studied. All experiments have done under controlled conditions (25 ±2) Cº and 1000Lux light intensity for 16 hrs / day. Results revealed that supplementing the media with BA at concentrations 2.0 and2.5 mg/l was superior to give highest rate of shoot and number of leaves reached 5.8 /explant and 6.0 l
... Show Moreهذا البحث يتحدى الافتراض القائل أن العراق بعد عام 2003 يجب دراسته بمعزل عن ديناميات التي سبقت عام 2003، اذ تبرهن هذه الدراسة على ان الشعبوية هي احدى الديناميات التي تمظهرت بصورة شعبوية استبدادية في النظام الديكتاتوري، نظرًا لأنه كان زعيم حزب علماني وعربي على نطاق واسع، لكنه استخدم الدين والقومية بشكل استراتيجي وانتقائي في ظروف معينة، مما خلق سياق الشعبوية الحديثة. الموجة الثانية هي الشعبوية العرقية والطائف
... Show MoreA mathematical model and associated computer program were developed to simulate the steady state operation of wiped film evaporators for the concentration of glycerol-water solution. In this model, various assumptions were made to facilitate the mathematical model of the wiped film evaporator. The fundamental phenomena described were: sensible heating of the solution and vaporization of water. Physical property data were coded into the computer program, which performs the calculations of this model. Randomly selected experiments were carried out in a small scale wiped film evaporator from ALVAL COMPANY, using different concentrations of the glycerol solution (10, 30 and 50 Wt. %) for different feed rates (30, 50, 80, 100 and 120 l/h) and
... Show MoreThe subject of multi- ethnics is one of the most important subjects in the study of political
geography, as multi- ethnics and its consequent problems are global geopolitical phenomena
that started early and reached its peak with the beginning of the twentieth century, because of
major changes in the political landscape that resulted by wars and led to the collapse of many
empires and major powers, a matter which led to put new political maps according to certain
considerations of the colonial powers, especially in Africa and Asia. All these things led to
the most serious challenges based on ethnic and sectarian conflict and led to the development
of geopolitical problems. Among the examples what most countries in th
