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.
This research is a continued efforts for a project on the fire tube boiler control for Al Rasheed edible oil factory. The aim is to enhance the control system with new integral control one. A functional blocks diagram (FBD) was built and simulated. With Schneider smart relays, FBD differs than ladder logic programming in which the PID option is active. An extensive work was done to understand the operation sequence, emergency shutdown, and faults causing the trips. A control program was designed to control logical sequence of operation. Furthermore temperature is controlled via cascade control with fuel and air controllers. The temperature controller output is send as remote set point to the fuel controller in a serial cascade manner. The f
... Show MoreThis research is concerned with documenting traditional clothes of girls and children in Makkah in the past 100 years and is a step towards preserving our heritage which is exposed to rapid changes. The researcher’s goal is to contribute to the Saudi’s folklore studies with a qualitative study of clothes and ceremonies used in the past. Sources of information were collected from human and material samples, ceremonies, clothes, techniques used to embellish them and from previous studies. The study concludes that aspects of civilization influenced clothes and resulted in a great deal of change. Children wore scale-down versions of adult clothing. Costumes were rich by their styles and adornment. The researcher emphasizes the importance
... Show MoreABSTRACTBackground: Concerns about hepatitis A infections is increasing worldwide specially after improving economic and sanitary conditions in many countries making older age groups who escape infection on early life vulnerable to infection.Objectives: The objectives were to estimate the frequency of hepatitis A among children consulting Al Alwyia pediatric Teaching Hospital during the year 2013 and to study some demographic characteristics of the disease.Methods: This cross - sectional hospital -based study wasconducted during 2013-2014 and include pediatric patients(43525 patients) who consult Al Alwyia pediatric hospitalduring that time. The outcome is total IgM antibodies tohepatitis A virus detected using Enzyme Linked FluorescentA
... Show MoreIn this research, design of advanced material for sunlight conversion requires focused research to obtain efficient photocatalytic system. Nanostructured ZnO was synthesized using spin coating technique. The structural, morphological and optical properties of annealed nanostructured ZnO thin film at 390 Co for 3 hours were characterized by x-ray diffraction, atomic force microscope AFM and UV-VIS spectrophotometer. Nanostructured ZnO was applied for removal Methylene Blue (MB) dye from water using sunlight induced photocatalytic process. Overall degradation of MB/ZnO was achieved after 120 minutes of sunlight irradiation while it needs more time for MB alone. The reaction rate constant fit pseudo first order for MB/ZnO degradation was 0.
... Show MoreBackground: Polycystic ovarian syndrome is one of the common gynaecological diseases encountered nowadays in the gynaecological clinic. Many criteria and diagnostic test had been evolved to be used with different classifications methods.Objectives: The present study aimed to measure the anti-mullerian hormone levels in serum of the women with Polycystic Ovary Syndrome and to test the possibility that if it can be used as a marker for diagnosis of polycystic ovary syndrome patients.Methods: A cross sectional study that had been conductedat Kamal AL-Samaraee Hospital, AL-Suwayrah Hospital andAl-Elwiya Maternity Teaching Hospital during the periodfrom July, 1st, 2013 – Jan. 1st, 2014. Where forty women withPolycystic ovarian syndrome (wit
... Show MoreAssessment of annual wind energy potential for three selected sites in Iraq has been analyzed in the present work. The wind velocities data from August 2014 to July 2015 were collected from the website of Weather Underground Organization (WUO) at stations elevation (35m, 32m, and 17m) for Baghdad, Najaf, and Kut Al-Hai respectively. Extrapolation of stations elevation and wind velocities was used to estimate wind velocities at (60m, 90m, and 120m). The objectives are to analyze the wind speed data and assess the wind energy potential for wind energy applications. Computer code for MATLAB software has been developed to solve the mathematical model. The results are presented as a monthly and annual average for wind velocities, standard deviat
... Show MoreNuclear emission rates for nucleon-induced reactions are theoretically calculated based on the one-component exciton model that uses state density with non-Equidistance Spacing Model (non-ESM). Fair comparison is made from different state density values that assumed various degrees of approximation formulae, beside the zeroth-order formula corresponding to the ESM. Calculations were made for 96Mo nucleus subjected to (N,N) reaction at Emax=50 MeV. The results showed that the non-ESM treatment for the state density will significantly improve the emission rates calculated for various exciton configurations. Three terms might suffice a proper calculation, but the results kept changing even for ten terms. However, five terms is found to give
... Show MoreA comparative study was done on the adsorption of methyl orange dye (MO) using non-activated and activated corn leaves with hydrochloric acid as an adsorbent material. Scanning electron microscopy (SEM) and Fourier Transform Infrared spectroscopy (FTIR) were utilized to specify the properties of adsorbent material. The effect of several variables (pH, initial dye concentration, temperature, amount of adsorbent and contact time) on the removal efficiency was studied and the results indicated that the adsorption efficiency increases with the increase in the concentration of dye, adsorbent dosage and contact time, while inversely proportional to the increase in pH and temperature for both the treated and untreated corn leav
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