Background:The demand for esthetic orthodontic appliances is increasing so that the esthetic orthodontic archwires were introduced. This in vitro study was designed to evaluate the surface roughness offiber-reinforced polymer composite (FRPC) archwires compared to coated nickel-titanium (NiTi) archwires immersed in artificial saliva. Materials and Methods:Three types of esthetic orthodontic archwires were used: FRPC (Dentaurum), Teflon coated NiTi (Dentaurum) and epoxy coated NiTi (Orthotechnology). They were round (0.018 inch) in cross section and cut into pieces of 15 mm in length.Forty pieces from each type were divided into four groups; one group was left at a dry condition and the other three groups were immersed in artificial saliva (pH=6.75 ± 0.015) at 37ºC for 1, 14 and 28 days intervals. The AFM was used to evaluatesurface analysis of all samples.ANOVA, Kruskal-Wallis, LSD and Mann-Whitney U tests were used to identify and localize the source of differences among the groups. Results:At each immersion period, FRPC wires exhibited the highest Ra among the study groups, except at 28 days immersion period where the Teflon coatings were the roughest. On the other hand, the least rough surfaces were the epoxy coatings when compared to analogous esthetic archwires, except at 1 day immersion period where the Teflon coatings had the least roughness. However, statistically non-significant differences were found between Teflon and epoxy at the dry condition and the 1 day immersion. Conclusions:The epoxy coated archwires are the best and the most appropriate esthetic orthodontic alignment archwires in term of the least surface roughness initially and over the course of study period.
Abstract :
The research aims to Estimate the Strength of Strategic Innovation application in terms of application strength , and on the overall level in number of Iraqi Industrial business organizations . After wards determine whether their is differerences among those organizations in application process for the dimensions , and for the overall process .
The Research revealed number of conclusions including that the process of strategic innovation is applied in a good Level , and demonstrates the desier of the industrial companies Leaders to Launch beyond the familiar products , and to provide new products that
... Show MoreIn this work the production of activated carbon (AC) from Imperata is done by microwave assisted Potassium hydroxide (KOH) activation and using this activated carbon for the purpose of the uptake of amoxicillin (AMX) by adsorption process from aqueous solution. The effects for irradiation power (450-800W), irradiation time (6-12min) as well as impregnation ratio (0.5-1 g/g) on the AMX uptake and yield AMX uptake at an initial concentration of AMX (150 mg/g). The optimum conditions were 700 W irradiation power, 10 min time of irradiation, as well as 0.8 g/g impregnation ratio with 14.821% yield and 12.456 mg/g AMX uptake. Total volume of hole and the area of the surface (BET) are 0.3027 m³/g, and 552.7638 m²/g respectively. The properti
... Show MoreThis paper is summarized with one of the applications of adsorption behavior; A UV-Vis method has been applied to survey the isotherm of adsorption. Results for experimental showed the applicability of Langmuir equation. The effect of temperature on the adsorption of cobalt (II) Complex by bentonite surface was studied. The results shown that the amount of adsorption was formed to increase, such as the temperature increase (Endothermic process). Cobalt (II) Complex has adsorption studies by bentonite surface at different pH values (1.6-10); these studies displayed an increase in adsorption with increasing pH. ΔG, ΔH, and ΔS thermodynamic functions of the cobalt (II) Complex for their adsorption have been calculated.
Laser cleaning of materials’ surfaces implies the removal of deposited pollutants without affecting the material. Nanosecond Nd:YAG pulsed laser, operating at 1064 nm and 532nm, was utilized. Different laser intensities and number of pulses were used on metallic and non-metallic surfaces under O2 and Ar environments to remove metal oxide and crust. Cleaning efficiency was studied by optical microscope. The results indicated the superiority of 1064 nm over the 532 nm wavelength without any detectable damage to materials’ surfaces. Marble cleaned in Oxygen gas environment was better than in Ar gas.
This paper is summarized with one of the applications of adsorption behavior; A UV-Vis method has been applied to survey the isotherm of adsorption. Results for experimental showed the applicability of Langmuir equation. The effect of temperature on the adsorption of cobalt (II) Complex by bentonite surface was studied. The results shown that the amount of adsorption was formed to increase, such as the temperature increase (Endothermic process). Cobalt (II) Complex has adsorption studies by bentonite surface at different pH values (1.6-10); these studies displayed an increase in adsorption with increasing pH. ∆G, ∆H, and ∆S thermodynamic functions of the cobalt (II) Complex for their adsorption have been calculated
Aeroelastic flutter in aircraft mechanisms is unavoidable, essentially in the wing and control surface. In this work a three degree-of-freedom aeroelastic wing section with trailing edge flap is modeled numerically and theoretically. FLUENT code based on the steady finite volume is used for the prediction of the steady aerodynamic characteristics (lift, drag, pitching moment, velocity, and pressure distribution) as well as the Duhamel formulation is used to model the aerodynamic loads theoretically. The system response (pitch, flap pitch and plunge) was determined by integration the governing equations using MATLAB with a standard Runge–Kutta algorithm in conjunction with Henon’s method. The results are compared with
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Investment in the human resource has become an important part of the strategies of educational organizations so that they can be competitive, so that the access of academics in universities to the international awards as a result of their research excellence indicates the effectiveness of this human talent so the interest has emerged in the implementation of a strategy to manage these human talent in organizations in general and educational ones In particular as one of the power sources that can not be imitated. The focus of the organization on the interaction between the working people has increased attention to the human element in order to achieve the desired quality levels, which called for organi
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