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 paper examines some syntactic features of English legal texts, and the changes that may be reflected on these features when they are translated into Arabic. For example, passivization, nominalization, complex sentences and modality. The researcher tries to demonstrate why it is difficult to suggest a specific translation of each syntactic feature, especially the modal verbs. The researcher also attempts to provide translations for some legal sentences written in some charters and international organizations. The descriptive methodology is used to identify the characteristics of these syntactic features in order to provide a proper translation of each legal sentence. It has been concluded that the translator has to be aware of the preci
... Show MoreThe effects of solar radiation pressure at several satellite (near Earth orbit satellite, low Earth orbit satellite, medium Earth orbit satellite and high Earth orbit satellite ) have been investigated. Computer simulation of the equation of motion with perturbations using step-by-step integration (Cowell's method) designed by matlab a 7.4 where using Jacobian matrix method to increase the accuracy of result.
The research entitled "The Slogans of Demonstrators at Al-Tahreer Square – analytical study for communicative letters" studies the slogans of demonstrators as a communicative means having many signs reflecting the political, social, cultural relations exist in the minds of people. It is so easy to understand its meaning, examining its goals; and explaining their meanings. For these reasons, we have chosen such a topic. Since the means of communications transfer letters between a sender and receiver, the importance of this research is that it is a researchable trial to acknowledge the issues behind the demonstrators' slogans and the different styles have been chosen by them for a whole year; the different sides of the demonstration sinc
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This study's objective is to assess how well UV spectrophotometry can be used in conjunction with multivariate calibration based on partial least squares (PLS) regression for concurrent quantitative analysis of antibacterial mixture (Levofloxacin (LIV), Metronidazole (MET), Rifampicin (RIF) and Sulfamethoxazole (SUL)) in their artificial mixtures and pharmaceutical formulations. The experimental calibration and validation matrixes were created using 42 and 39 samples, respectively. The concentration range taken into account was 0-17 μg/mL for all components. The calibration standards' absorbance measurements were made between 210 and 350 nm, with intervals of 0.2 nm. The associated parameters were examined in order to develop the optimal c
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This study was designed to evaluate the effect of major surgery on thyroid hormones and thyrotropin in patient undergoing major lower abdominal surgery. The study included fifty patients scheduled for elective major lower abdominal surgery, the serum levels of T3, T4 and TSH were determined one day preoperatively, intraoperative, one day postoperatively, two days postoperatively, and rT3 was determined one day preoperatively, and one day postoperatively. We observed that the levels of (T3, T4, TSH) increased significantly (P<0.05) intraoperatively, one day postoperatively the levels of T3 and T4 reduced significantly (P<0.05), while TSH reduced not significantly (P>0.05), and two days postoperatively T4 and TSH returned to increase si
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The comedian scenes which Shakespeare has entered in some of his tragedies(Hamlet, King Lear, and Macbeth), constantly the wrath of conservative critics and theorists of Western Drama, as big violation to Aristotle’s rules of tragedy that is forbidden to insert comedian scene in tragedy. Chapter one deals with the research problem, and its significance, purpose,Boarders and the definition of Comic Relieve. Chapter two comprises the theoretical framework which has displayed Arist-Otle’s conception about the imitation way of heroes characters between tragedy and comedy, the different function of catharsis in each one. Then the research has exposed the economical and theatrical activities in London during Elizabethan age which was looke
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The fish assemblage in the East Hammar marsh was studied during December 2009 to May 2010. The fish fauna of the marsh consisted of 17 native, 23 marine (49%) and seven alien species. The dominant species were Liza abu (14.6%), Carassius auratus (13.4%) and Thryssa mystax (11.2%). The resident species formed 44.7%, occasional species 36.1% and seasonal species 19.2% of the total number of fish species. Fish species diversity index ranged from 1.28 to 2.61, richness from 1.98 to 4.50 and evenness from 0.45 to 0.78. Salinity ranged from 1.45 to 7.74‰. The increase in the proportion of marine species (49%) in the fish assemblage due to marine waters progress from Arabian Gulf had an impact on the values of ecological indices and the
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The specialized Journalism plays an important role in our daily lives using all of its different ways, including news, caricature, commentary and dialogue. The specialized Journalism deserves vigilance and interest for it is caring about having a new media system. It is meant by “specialization”, first: identifying the areas of work in which the person concerned possesses great knowledge in the specialty resulting from a long experience, it also means being able to continuously develop required skills in that specialty. The specialization is not only a feature of the press, but also a feature of human development; thousands of years ago, the primitive society consisted of people from different specializations: fishermen, farmers, her
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Objectives: The study aimed to determine the effect of chemotherapy on the life style of patients who
receive chemotherapy.
Methodology: A descriptive study was conducted in Specialty Surgery Teaching Hospital, Al-yamok
Teaching Hospital, and Radiation and Nuclear Medicine Hospital in Baghdad for the period from May
2007 to October 2008. A purposive "non-probability" sample of (loo) patients with bladder cancer
who receive chemotherapy where concerned in this study.
A questionnaire fom was constnicted for the purpose of the study and it was comprised of
two parts. The questiormaire consists of (125) items. They include (1) demographic information (2)
assessment of lifestyle dimension. The content validity of the q