Density functional theory (DFT) with B3LYP level and 6-311G[Formula: see text] basis sets for light atoms like N and O and SDD basis sets for heavy atoms like Sn is used to examine the interaction of tin dioxide nanocrystals with nitrogen dioxide as a function of temperature from 273[Formula: see text]K to 373[Formula: see text]K through a Gaussian 09W software program. Gibbs free energy, enthalpy, and entropy of activation and reaction are calculated. The situation of transition of SnO2 clusters toward nitrogen dioxide is investigated. According to the findings, the activation energy of SnO2 clusters with nitrogen dioxide increases as the temperature rises (in negative value). Gauss view 05 was used to investigate the geometrical structure of SnO2 cluster nanostructures and the nitrogen molecule. Spectroscopic analysis of the force constant, IR, Raman scattering and reduced masses as a function of frequencies had been investigated and compared to the experimental value of longitudinal optical (LO) modes of 690[Formula: see text]cm[Formula: see text] for SnO2 and 1600[Formula: see text]cm[Formula: see text] for NO2.
Background and objectives: This study aimed at testing the effect of plastic sleeve or barrier, used to cover the guide of the light cure unit to prevent cross-infection, on the shear bond strength and site of bond failure of stainless steel and ceramic orthodontic brackets. Materials and methods: Forty orthodontic brackets; twenty stainless steel and twenty ceramic brackets bonded to forty extracted human maxillary first premolars using light cure adhesive cured with and without the use of a protective plastic barrier on the guide. Comparing the effect of this barrier on the shear bond strength and adhesive remnant index was performed using an independent t-test and Chi-square test. Results: The protective barrier had decreased the shear b
... Show MoreExpansive soil is one of the most serious problems that face engineers during the execution of any infrastructure projects. Soil stabilization using chemical admixture is one of the most traditional and widespread methods of soil improvement. Nevertheless, soil improvement on site is one of the most economical solutions for many engineering applications. Using construction and demolishing waste in soil stabilization is still under research., The aim of this study is to identify the effect of using concrete demolishing waste (CDW) in soil stabilization. Serious tests were conducted to investigate the changes in the geotechnical properties of the natural soil stabilized with CDW. From the results, it is concluded that the
... Show MoreBackground: Waterpipe and cigarette are two products of tobacco consumption, tobacco use has detrimental effects on the oral cavity, numerous studies around the world have reported a significant relationship between smoking and increase dental caries and viable count of cariogenic bacteria, Materials and Methods: unstimulated saliva was collected from 84 subjects and divided equally into three groups waterpipe smokers, cigarette smokers, and non-smokers all of the participants are adult male aged between 25-60 years, dental caries was measured by use DMFT index, while S.mutans and S.sobrinus were isolated by using a selective medium SB 20M (Sugar bacitracin-20 modified) agar Results: this present study showed a significant (p≤0.01)
... Show MoreThis article examines and proposes a dietary chain model with a prey shelter and alternative food sources. It is anticipated that mid-predators' availability is positively correlated with the number of refuges. The solution's existence and exclusivity are examined. It is established that the solution is bounded. It is explored whether all potential equilibrium points exist and are locally stable. The Lyapunov approach is used to investigate the equilibrium points' worldwide stability. Utilizing a Sotomayor theorem application, local bifurcation is studied. Numerical simulation is used to better comprehend the dynamics of the model and define the control set of parameters.
Amino and fatty acids in the liver tissue of Uromastyx aegyptius microlepis during the periods of hibernation (December) and activity (May) were estimate by a high performance liquid chromatography, liver of a lizard during the activity and hibernation seasons, contained 18 amino acids, which include, 10 essential amino acids and 8 non-essential amino acids, and the liver in the male lizard contained five fatty acids during each season, the concentration rates of all the amino acids during the activity season were higher than their counterparts during the hibernation season, the total concentrations of essential and non-essential amino acids during the activity season were 19434.8 µg/ml, which was greater than the total concentrations leve
... Show MoreThe current study is based on previous findings, where corporate governance (CG) significantly increased corporate social responsibility (CSR) to enhance transparency while reducing the tendency of corporate management to engage in earnings management (EM). A sample of 11 Iraqi banks listed on the Iraq Stock Exchange from 2010 to 2020 was selected. The CG was included in the board size and board independence apart from the variables of Chief Executive Officer (CEOs) gender, majority shareholder ownership, foreign ownership, and institutional ownership. The CSR included the wage growth rate, bank contribution growth rate for social security, training programmes, subsidies, environmental protection, and bank compliance with the law. Specifica
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