Chlorinated volatile organic compounds (CVOCs) are toxic chemical entities emitted invariably from stationary thermal operations when a trace of chlorine is present. Replacing the high-temperature destruction operations of these compounds with catalytic oxidation has led to the formulation of various potent metal oxides catalysts; among them are ceria-based materials. Guided by recent experimental measurements, this study theoretically investigates the initial steps operating in the interactions of ceria surface CeO2(111) with three CVOC model compounds, namely chloroethene (CE), chloroethane (CA) and chlorobenzene (CB). We find that, the CeO2(111) surface mediates fission of the carbon–chlorine bonds in the CE, CA and CB molecules via modest reaction barriers. As a result of localization of excess electrons left behind after creation of oxygen vacancies, analogous fission over an oxygen vacant surface systematically necessitates lower energy barriers. Dehydrochlorination of CE and CA molecules preferentially proceeds via a dissociative addition route; however, subsequent desorption of vinyl and ethyl moieties requires less energy than surface assisted β C–H bond breakage. The profound stability of hydrocarbon species on the surface contributes to the observed deactivation of ceria at temperatures as low as 580 K under pyrolytic conditions. Adsorption of an oxygen molecule at an oxygen vacant site initiates decomposition of the adsorbed phenyl moiety. Likewise, adsorbed surface hydroxyl groups serve as the hydrogen source in the observed conversion of CB into benzene. A plausible mechanism for the formation of 1,4-dichlorobenzene incorporates abstraction of a para hydrogen in the CB molecule by an O− surface anion followed by chlorine transfer from the surface. Plotted conversion–temperature profiles via a simplified kinetic model against corresponding experimental profiles exhibit a reasonable agreement. The results from this study could be useful in the ongoing efforts to improve ceria's catalytic capacity for destroying CVOCs.
In this research, we highlight the most important research related to the mixed ligand complexes of the drug trimethoprim (TMP), and for the past 7 years where this drug has been used as a chelating ligand and gives stability to the complexes with ions of metal elements where these complexes, prepared and diagnosed, and for some research the bacterial activity was studied against different types of bacteria.
Background : The number of primary hip arthroplasty is growing with every passing year. At present this surgical operation has no equal in the rate of yielding good results. Despite the fact that in many cases in the long term after surgery radiolucent lines around the cup are observed, the clinical outcomes remain satisfactory.Aim of the study :To study the clinical and radiological manifestations of the aseptic loosening of the endoprosthesisMethods: This is a prospective study based on an analysis of diagnostic findings of 51 patients with aseptic loosening of hip joint components, aged 30 to 84 years. We depend for diagnosis of a septic losing by both clinical evaluation and X-ray assessment Results:The majority of clinical and
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« This paper presents the indicators of the development of excellent public relations in the institutions of higher education that are possible for three contextual variables: institutional, professional, professional, and effective communication. Therefore, the study used six indicators to measure the excellent public relations in institutions of higher education and scientific research. These indicators are based on the theory of excellence in public relations . Research Objectives: The aim of the research paper is to uncover the institutional, professional, and professional indicators of effective communication of excellent public relations in higher education institutions. Resea |
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In the region of the north of Iraq using the method of analyzing thin section microfacies to 38 of rockyslices which were gathered from a place near Aqra city. These slides are divided into seven microfacies depending on lithologcal component and fossils.
1) Dolostone facies.
2)Recrystallized bioclastic wackestone facies.
3) Bioclastic packstone microfacies
4)Sucrosic dolomite facies.
5) Bioclastic grainstone in microfacies.
According to water energy, these facies were divided to three zone:
- a) Low energy environment.
- b) Transitional zone.
- c) High energy environment.
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Giant Cell Fibroma (GCF) is a relatively rare oral mucosal lesion, so named due to the characteristic giant cells present within the fibrous stroma of the lesion, limited number of clinicopathological studies were performed in previously published literature. This study was performed to evaluate the clinicopathological features of Giant cell fibroma in a sample of Iraqi patients. Formalin-fixed paraffin-embedded sections from 22 giant cell fibroma in period between 2010 and 2018 were retrieved from the laboratory of oral pathology of Baghdad University/College of Dentistry, Clinical data and microscopic features were reviewed and analyzed according to the available surgical reports. The mean age of patients at the time of diagnosis was 29.6
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Interest has largely centered on the use of plant fibers to reinforce plastics, because these fibers are abundant and cheap. Carrot fibers (Curran) have been extracted from carrot, left over from carrot juice manufacture. The fibers of two sizes fine (50<µm) and coarse (100-150 µm) have been mixed with epoxy in four levels of loading (10, 20, 30, 40 wt %) respectively. Impact test, shore d hardness test and three point bending test of epoxy and carrot fiber-epoxy composites samples have been determined. The impact strength values of samples prepared with fine and coarse fibers increased as compared with pure epoxy sample. Hardness values increased, and the Young’s modulus values decreased with fiber content of both sizes.
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Shallow foundations have been commonly used to transfer load to soil layer within the permissible limits of settlement based on the bearing capacity of the soil. For most practical cases, the shape of the shallow foundation is of slight significance. Also, friction resistance forces in the first layers of soils are negligible due to non-sufficient surrounding surface area and compaction conditions. However, the bearing capacity of a shallow foundation can be increased by several techniques. Geocell is one of the geosynthetic tool applied mainly to reinforce soil. This study presents a numerical approach of honeycombed geocell steel panels reinforcing the sandy soil under shallow foundation, and several parameters are investigated such as th
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