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.
Is hardly day expire without hearing the news either Abuse Managementthe accounting standards or the existence of serious misstatements by someauditors.Which caused the demanding of many companies in the recent republication of the financial statements and the re-announcement of its financialresults. Such acts raise questioning about the role that should be played by theauditors, prompting agencies responsible for setting auditing standards to takeTo throw increasingly responsibility on the auditors in order to interest risksfraud The Risks of Fraud in their review of the financial statements.also The Public Company Accounting Oversight Board in the U.S.called about the need of owning the Certified Public Accountants those whoaudits for
... Show MoreBackground: Many types of instruments and techniques are used in the instrumentation of the root canal system. These instruments and techniques may extrude debris beyond the apical foramen and may cause post-instrumentation complications. The aim of this study was to evaluate the amount of apically extruded debris resulted by using 4 types of nickel-titanium instruments (WaveOne, TRUShape 3D conforming files, Hyflex CM, and One Shape files) during endodontic instrumentation. Materials and methods: Forty freshly extracted human mandibular second premolar with straight canals and a single apex were collected for this study. All teeth were cut to similar lengths. Pre-weighted glass vials were used as collecting containers. Samples were randoml
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A newly developed FIA-merging zones spectrophotometric system, the method is rapid, accurate and sensitive for metformin hydrochloride determination through the oxidation of 1- naphthol by sodium hypochlorite and coupling with metformin.HCl in the presence of sodium hydroxide to form a blue soluble ion pair and this product was determined using homemade CFIA-Merging zones techniques , at 580 nm. Data treatment shows that linear range is (0.5-35) µg/ ml. The optimization conditions for various chemical and physical conditions of [MTF- NaOCl-α-naphthol-NaOH] system were investigated. The LOD was 0.01µg / ml and LOQ 0.1µg/ml from the lowest concentration of the calibration graph with r2% 99.18 and RSD% did
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The research aimed to evaluate the financial performance of the Public Company for the manufacture of medicines and medical supplies / Samarra - Iraq to know the strengths and weaknesses that affect its performance, as well as to compare its performance in the years between (2017-2019), which are characterized by security stability with its performance in previous years (2014 -2016) which is characterized by security instability, to assess the extent of its ability to achieve growth in performance, by answering the main question, what is the evaluation of the performance of the Public Company for the manufacture of medicines and medical supplies / Samarra - Iraq in the light of financial indicators?
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Two dwarf snakes were discovered, Eirenis thospitis Schmidtler & Lanza from Sereen mountain, north east of Arbil and E. rothii Jan from Saffin mountain North of Arbil city North of Iraqi Kurdistan. Supported by description and important notes on variation. In addition summarized list for 9 species of the genus Eirenis Jan in Iraq is also presented.
bstract This study was performed to isolate and identify the Burkholderia cepacia from rhizosphers of different plants and study their ability to produce Siderophore, the study was also aimed to assess the antifungal activity of the bacterial filtrate and extracts of the isolates against some pathogenic fungi. The isolate which showed higher inhibitory effects was selected for extraction of some active metabolites produced by it, and evaluate the activity in vitro, via inhibition of the growth of the fungi using different concentrations of extract (50, 100, 200 )µL/ml , The results showed that out of (250) samples of soil , (8) isolates (3.2%) gave positive
... Show MoreMM ABDUL-WAHHAB, SA AHMED, International Journal of Pharmaceutical Research, 2020 - Cited by 2
Cadmium has been known to be harmful to human healthy , manily Via contaminated drinking water , food supplies , tobacco and industrial pollutant . The aim of this study was to determine the toxicity of new Cadmium (II) complex ( Bis[ 5- ( P- nitrophenyl ) – ? 4 – Phenyl- 1,2,4- triazole -3- dithiocarbamatohydrazide] cadmium (II) Hydra ( 0.5) and compare it with anticancer drug cyclophosphamide ( CP) in female albino mice . This complex causes to several alterations in Enzymatic activity of Glutamate Pyruvate Transaminase (GPT) and Alkaline Phosphatase (ALP ) in three organs after the treatment of mice with different doses of a new cadmium (II) complex ( 0.09 / 0.25ml , 0.18/ 0.5ml and 0.25mg /0.7 ml /30 gm of mous
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This piece of research work aims to study one of the most difficult reaction and determination due to continuous and rapid variation of reaction products and the reactants. As molybdenum (VI) aid in the decomposition of hydrogen peroxide in alkaline medium of ammomia, thus means a continuous liberation of oxygen which cuases and in a continuous manner a distraction in the measurement process. On this basis pyrogallol was used to absorbe all liberated oxygen and the result is an a clean undisturbed signals. Molybdenum (VI) was determined in the range of 4-100 ?g.ml-1 with percentage linearity of 99.8% or (4-300 ?g.ml-1 with 94.4%) while L.O.D. was 3.5 ?g.ml-1. Interferring ions (cations and anions) were studied and their main effect was red
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