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.
The purpose of this paper is to introduce and study the concepts of fuzzy generalized open sets, fuzzy generalized closed sets, generalized continuous fuzzy proper functions and prove results about these concepts.
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Asthma is a chronic respiratory disease highly prevalent worldwide. Recent studies have suggested a role for microbiome-associated gut–lung axis in asthma development. In the current study, we investigated if Resveratrol (RES), a plant-based polyphenol, can attenuate ovalbumin (OVA)-induced murine allergic asthma, and if so, the role of microbiome in the gut–lung axis in this process. We found that RES attenuated allergic asthma with significant improvements in pulmonary functions in OVA-exposed mice when tested using plethysmography for frequency (F), mean volume (MV), specific airway resistance (sRaw), and delay time(dT). RES treatment also suppressed inflammatory cytokines in the lungs. RES modulated lung microbiota and cause
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Language is an important means through which one can construct one's social world. Accordingly, the way we view ourselves and the world is basically formed by language use whereby identities, relations, and values are constructed and maintained. Most discourse analysts consider narrative not only the locus of construction and enactment of identity, but also a distinguished genre for its analysis.The present study is concerned with how identity can poetically be informed, hence exploring the way black poets use language when reflecting their identity and culture. The poem, right on: white america by the black American poetess Sonia Sanchez, is chosen to be analyzed based on Simpson's stylistic model (2004). In this model, the ana
... Show MoreThe aim of this research does not deal with evaluation occurs at any points in the design of the plan alternatives themselves or formulation of goals and objectives. The aim of this research is that test and evaluate the fully alternatives. We can therefore state as the principle that evaluation of alternative plans must be based on attempts to show how far each plan satisfies all the objectives are expressed as specification of the performance of the urban and regional system. The planner can submit the result (as in the traditional way) for each alternative, with particular reference to the weighting of objectives. The summery result can be presented and the preferred plan indicated that with largest index of Goals-achievement.
... Show MoreThe research aimed to identify "the effectiveness of educational-learning design according to the model of brain compatibility in achievement among firstmiddle grade students in mathematics", in schools affiliated with the Second Karkh Directorate of Education. To achieve the goal of research, the following zero hypothesis has been formulated: " There is no statistically significant difference at the semantic level (05.0) between the average scores of experimental group students who will study with design accreditation (educational - learning) according to the brain compatibility model and the grades of control group students who will study in the usual way in the achievement thinking test". The research community, which is represented by
... Show MoreThe study included a statement toxicity of some heavy metals individually and collectively and the existence of plant nutrients in the center Agirenk bluish green moss growth and Askhaddm biomass as an indicator of the study, in addition to portability moss on the accumulation of the metal
The current phase distinguish by the rapid scientific development, which pushes individuals to have the necessities of scientific and practical life through the proper scientific thinking which contribute to the development of invention and creativity away from memorizing and indoctrination and encouraging individuals to looking for information and then attempting to process and develop these information instead of being a passive receiver. The investment of minds becomes the logical investment in all societies by preparing the citizen to become able to face life changes and its necessities. It is very important to take care of individuals and develop their mental abilities and thinking skills. The constructive strateg
... Show MoreThe Green Productivity topic is considered as one of the more conceptual novelty in the field of Production and Operations Management, and one of the least topics addressed in the literature competent, Green Productivity (GP) is a strategy for enhancing a business's Productivity and environmental performance at the same time, for overall socio - economic development, It is the application of appropriate techniques , technologies , and management systems to produce environmentally compatible goods and services. the research aimed to find the contribution of this concept for success the industrial Organizations.
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