Abstract: Objectives: To investigate the effect of temperature elevation on the bonding strength of resin cement to the zirconia ceramic using fractional CO2 laser. Background: Fractional CO2 laser is an effective surface treatment of zirconia ceramic, as it increases the bonding strength of zirconia to resin cement. Methods: Thirty sintered zirconia discs (10 mm diameter, 2 mm thickness) were prepared and divided to three groups (N=10) and five diffident pulse durations were used in each group (0.1, 0.5, 1, 5 and 10 ms). Group A was treated with 10 W power setting, group B with 20 W and group C with 30 W. During laser irradiation, temperature elevation measurement was recorded for each specimen. Luting cement was bonded to the treated zirconia surfaces and cured for 30 seconds. Shear bond strength was evaluated by a testing machine (universal) with bond failure mode determination. Results: The lowest temperature elevation measurement of the irradiated specimen which gave maximum shear bond strength was about 1.6±0.3 Ċ higher than ambient room temperature (27±0.2 ºC). Apparent micromechanical irregularities were seen in the treated samples and cracks formation with increased pulse duration and power setting were also observed. Conclusions: The temperature elevation is a vital factor in the surface roughness of zirconia ceramic with fractional CO2 laser irradiation and the lowest temperature elevation at best shear bond strength of zirconia ceramic to the resin cement is satisfied with the shorter pulse duration of 0.1 millisecond.
Violence is a very serious phenomenon affecting the upbringing and culture kids, are playing the most violent forms of development of these Phenomenon, the research aims to determine the role of the media in reducing violence, and conducted a field study on parents Children by 200 form, the results revealed the importance of the media in raising awareness of the risks of violence on the child Especially television, which hugely increased Show features, as well as the role of parents in guiding the child to buy Useful because the game to play negative impact of violence on children's health, and the media play an important role in raising awareness of these Risks through educational programs and television commercials, and o
... Show MoreThe fractional order partial differential equations (FPDEs) are generalizations of classical partial differential equations (PDEs). In this paper we examine the stability of the explicit and implicit finite difference methods to solve the initial-boundary value problem of the hyperbolic for one-sided and two sided fractional order partial differential equations (FPDEs). The stability (and convergence) result of this problem is discussed by using the Fourier series method (Von Neumanns Method).
The aim of the study was to know the factors analysis of scale Bar-On & Parker, post analysis is found fourteen factors for the first degree of the scale. Also we extracted five factors from the second degree.
The scale consists of (60) items , applied on sample of (200) students (Male &Female ) age (15-18) years randomly chosen from preparatory schools . The scale unveiled satis factors validity and reliability. An others aims is to low the emotional Intelligence level and know the difference of statistical in sex , age variable and the specialization variable .The result was no difference of statistical in sex and specialization variable , but the difference appear
... Show MoreIn this research, the influence of the fermentation treatments and baking in Iraqi’s flour type (Ibaa 99, Al-rashed, Tamus, Abu-grabe) and Turkish flour type (Muaamel) on phytic acid was investigated. In whole wheat flour, the phytic acid was (1500, 1290, 1450, 1230, 1440 ( mg/ 100 g flour respectively, and the inorganic phosphorous was (29.18, 25.15, 23.89, 20.85, 22.83) mg/100 g flour respectively. The dough prepared from flour with a higher phytic acid content also contained higher amount of phytic acid. During fermentation, degradation of phytic acid occurred. The cumulative loss of phytic acid after fermentation in all type of dough was ~ 23, 22, 34, 26 and 27% respectively،While increased of inorganic phosphorous occurred. The c
... Show MoreA new metal complexes are made from the ligands derived from amoxicillin based Schiff's base coordinated with Pd(II) and Co(II) have been synthesized and characterized via different spectroscopic methods. FT-IR spectroscopy have shown a formation of tetrahedral and square planar geometry for Co(II) and Pd(II) complexes, respectively. Surface morphology was inspected via field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The Brunauer–Emmett–Teller surface area of the metal complexes samples is about 6.63 to 8.71 m2/g, with pore diameters and volume of 0.030–0.0501 cm3/g and 18.39–22.98 nm, respectively. The quadrupo
Purpose: To use the balanced measurement approach as a strategic link for increasing the effectiveness of strategic planning in the direction of achieving satisfaction rates at Bisha University in Saudi Arabia
Design / methodology / approach –The questionnaire survey was used to collect the data of the study from the faculty members at University of Bisha.
Findings –Prove the assumption that the use of the balanced measurement approach - as a strategic planning tool - leads to maximize the satisfaction rates among faculty members at the University of Bisha.
Research limitations/implications- adopt effective strategic planning in order to achieve
... Show MoreThe study aimed to identify the degree of academic leaders practices at the University of Northern Border for creative leadership, which attribute to different variables (nature of work, employer, gender, years of experience in administrative work at the university). To achieve the goal of the study, the researcher used the descriptive approach survey. Therefore, the researcher used a questionnaire as a study tool, which consisted of (40) items that included dimensions (sensitivity to problems, initiative, originality, flexibility). The study sample consisted of (240) participants included (agents of colleges, and supporting deanships, and their employees) during the second semester of the academic year 1439/1440 AH. The results showed t
... Show MoreIn this study, the effects of blending the un-branched acrylate polymer known as Poly (n-decyl acrylate), and the branched acrylate polymer known as Poly (iso-octyl acrylate), on the viscosity index (VI), and the pour point of the Iraqi base stocks 40, and 60 respectively, were investigated. Toluene was used as a carrier solvent for both polymer types. The improvement level of oils (VI, & pour point) gained by blending the oil with the acrylate derived polymers was compared with the values of (VI, and pour point) gained by blending the oil with a commercial viscosity index, and pour point improver. The commercial lubricant additive was purchased and used by Al-Daura Refineries. It consisted of an un-known olefin copolymer dissolved i
... Show MoreThe Organizational Transparency is regarded one of the effective means in the attempts of the restoration and working to prevent the corruption and reduce the negative managerial economic social and political effects.
Accordingly, this study aims at importance of performing an explorative analytical study in order to stand on the effect of the Organizational Transparency in the reduction of environment of Iraqi Organizations.
To achieve this study, three hypotheses were chosen; the first is the correlation relation and the second is the effect and the third is the differences, and statistical means represented by correlation coefficient "Spearman", "", "Mann- Whit
... Show MoreHR Ghanim, GA Abdulhassan, International Journal of Early Childhood Special Education, 2022