Background: Coated aesthetic archwires are currently the existing solutions for the esthetic problem, but the color of these archwires tends to change overtime. This study was aimed to evaluate the color stability of different types of esthetic archwires from four different companies at different time periods after immersion of two different staining drinks which are tea and Pepsi cola. Materials and methods: 48 specimens were prepared, each specimen contains 10 aesthetic archwires; and were divided according to type of solution into two groups: A (tea) &B (Pepsi cola); each group contained 24 specimens (12 specimens were immersed in the staining solution as 4 specimens for each time intervals and 12 specimens were immersed in distilled water as control group). Each subgroup contains one specimen from each company. Color measurements were performed by means of a computed spectrophotometer according to the Commission Internationale de I’Eclairage L*a*b* system, and color changes (ΔE*) and National Bureau of Standards units. Results: Both staining solution caused color change in variable degree and the higher amount of color instability was found for the archwires from the Hubit Company while the least amount of color change was for the archwires from the Orthotechnology Company. Conclusion: The tea caused highly significant change on the aesthetic archwires which is higher than the effect of the Pepsi cola. Key words: Color stability, aesthetic archwires, staining drinks.
The present study was conducted to determine the optimum conditions required for lipase enzyme activity extracted from germinated sunflower seeds, including temperature, pH, agitation, time of incubation, enzyme concentration, substrate type, and concentrations of mineral salts and EDTA. Optimum pH, temperature and time of incubation required for lipase stability were also determined. The results showede optimum lipase activity (3.251U/ml) wasund at 30 ÌŠC and pH 7 after 20 minutes of incubation when using 1 ml lipase enzyme with 0.02 ml of CaCl2 (10 mM) at 100 rpm of agitation and in the presence of olive oil as the substrate for enzyme reaction. EDTA appeared to have inhibitory effects, while Ca+2 and Mg+2 have stimulatory effec
... Show MoreThe aim of this study is to develop the science textbook for the 1st intermediate grade by analyzing it according to life skills. Its core areas were mental skills, environmental skills, and health skills. The analysis tool was used after verifying its validity and stability in analyzing the science textbook for the 1st intermediate grade, and the results of the study resulted in the inclusion of mental skills on a high percentage of repetitions, while we find that this percentage is low in the inclusion of environmental and health skills. The study recommended the importance of achieving balance and justice in including skills in the science textbook for the 1st intermediate grade, by emphasizing the environmental and health skills by incr
... Show MoreThe press release plays an important role in understanding and recognizing the policy of governments by the public in managing the state, especially in times of crises, as it helps to clarify the position of the government and its decisions.In addition, it is considered as one of the most important tools of communication between the government and its public at the present time.
In light of the technical developments and adopting modern mechanisms in transferring of what is issued by the government, the press release has been edited and published electronically; and helps in the success of this transfer speed and knowledge of the reactions of the masses towards the implications,In a crisis like the Basrah crisis in particular, the Ira
The aim of the research is to clarify the measurement of the impact regarding financial value of human resources on investors' decisions by considering that the human element is one of the assets of the company. Therefore, a set of criteria must be available to determine the applicability of these standards in the human resource because it has an effective role in the success for the company. Is to measure the value of human resources in a financial format according to the first two methods depends on the value and the second depends on the cost.
In order to achieve the objectives of the study, a questionnaire was designed to survey the views of a number of employees of the General Company for Leather Industries in order to arriv
... Show MoreUniversity Campuses, as any lively physical entity, is subject to continuous variation due to . growth, development and change. This reality covers the existing or futuristic additives or additions, consecutively these changes may have a strong sensation of disorientation as a result of formatic changes in buildings, or in movement paths. And it epitomized the research problem to "the need for knowledge to clarify the impact of intellectual and executive policy in achieving coherence, functional and space organization of the elements of the university urban environment and in the stages of future growth and change," the search targeted "to highlight the study of constraction politics on campus Bmqomad
... Show MoreThe research to knows some biomechanics variables in different spots with and without players in basketball youth players and analysis by using destructive method in surfing study and the research were applied for jump shoot from one of basketball players in ( middle , left , right ) in side zone and out of zone also from three point shoot with and without defense and we depend on successful shoot on analyze .The results and conclusions that center of weight of the player on standby on high and knee angel and hips were more wide also the two angle of wrist , elbow on start of shooting be more wide with defender more than without defender .the maximum high center of weight and shooting angle and ball entrance being less degree with defender
... Show MoreThe research discusses the problem of salaries in the public sector in terms of the process of analyzing its structure and the possibility of benefiting from the information provided by the analysis process for the strategic planning process, and the General Authority for Groundwater has been adopted and one of the formations of the Ministry of Water Resources, which is centrally funded, to represent the salary structure of its employees (1117) employees be a field of research, as the salary structure in it was analyzed for the period between (2014-2019) using the quantitative approach to analysis and by relying on a number of statistical tools in the analysis process, including mathematical circles, upper limits, lower limits, p
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