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.
Background: Postpartum hemorrhage is an important cause of maternal morbidity and mortality. Considerable difference of opinion exist regarding the optimal approach to the management of the 3rd stage of labour, practice varies between countries &between units.Objectives: To evaluate the effectiveness of intra umbilical vein injection of oxytocin and umbilical cord driange in shortening the duration of third stage of labour.Patient and Methods: In this randomized controlled study, 100 women were enrolled in this study they divided into three groups. (Group 1 ,N =30 )received 20 units of oxytocin diluted in 20 ml 0.9% saline solution injected in the umbilical vein after clamping.(Group 2, N = 34) placental cord drainage.(Group 3,
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The major climate changes that have affected the planet in addition to wave the big drought plaguing the study area, including the lack of water for imports Badra River fatigue because of the Iran constructing dams on this river and make use of the waters for the benefitof its territory. The subject of finding sources of water has become available with the possibility of exploiting them in an exemplary manner is one of the key things in order to be exploited somewhere.
The study area was chosen within the eastern border of the province of Wasit within the district of Badra border, an area of (1557.5 km2) almost "to study the characteristics of hydrological and identify possibilities for water harvesting them. In this study was conduct
Abstract
The space occupied by the dialogic imperative in the language is a very wide range, as it is present in most of the speeches received by the recipient, and this is not limited to dialogues. That the literary discourse is a dialogical and fulfillment imperative, as the implication is related to the implicit connotations, as if the implication covers the indirect actions of the speech act theory.
The application of low order panel method with the Dirichlet boundary condition on complex aircraft configuration have been studied in high subsonic and transonic speeds. Low order panel method has been used to solve the case of the steady, inviscid and compressible flow on a forward swept wing – canard configuration with cylindrical fuselage and a vertical stabilizer with symmetrical cross section. The aerodynamic coefficients for the forward swept wing aircraft were calculated using measured wake shape from an experimental work on same model configuration. The study showed that the application of low order panel method can be used with acceptable results
The role of internal control is based on the effectiveness of the budget through an analysis of the reality of the budget in the research sample as it was studied in the preparation and preparation stages and the implementation stage. The sample showed that the sample did not comply with what is stated in the Ministry of Finance publication of instructions and ceilings. In the process of preparing and resulting from the occurrence of deviations in large proportions both in the discussion of the Ministry of Finance or when implementation as a low rate of implementation and the absence of allocations for some items, although there is a need for them as well as the transfer of large proportions of transfers both up or down and the purpose o
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This article investigates the decline of language loyalty in the age of audiovisual nearness. It is a socio-linguistic review of previous literature related to language disloyalty. It reviews the current theoretical efforts on the impact of audiovisual nearness created by social media and language loyalty. The descriptive design is used. The argument behind this review is that the audiovisual nearness provided by social media negatively affects language loyalty. This article concludes that the current theoretical efforts have paid much attention to the relationship between the audiovisual nearness and language loyalty. Such efforts have highlighted the fact that the social media platforms have provided unprecedented nearness that provoke in
... Show MorePurpose: The research aims to study the measurement of the performance of accounting units level of the research sample by using the Federal quality Model European (EFQM) Design/methodology/approach: the (EFQM) which included seven dimensions "Leadership, Strategic Planning, External Focus, Information and Analysis, Faculty / Staff and Workplace Focus, Process Effectiveness & Outcomes and Achievements" And its effect on the Control Environment, which includes three dimensions: "Integrity, management philosophy and commitment to powers" . the sample is supervisory units of colleges affiliated with the University of Baghdad in Iraq, and a sample was chosen that included fifty-one individuals in the accounting departments.
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CdSe quantum dots possess a tuning energy gap which can control gap values according to the size of the quantum dots, this is made the material able to absorb the wavelengths within visible light. A simple model is provided for the absorption coefficient, optical properties, and optical constants for CdSe quantum dots from the size 10nm to 1nm with the range of visible region between (300-730) nm at room temperature. It turns out that there is an absorption threshold for each wavelength, CdSe quantum dots begin to absorb the visible spectrum of 1.4 nm at room temperature for a wavelength of 300 nm. It has been noted that; when the wavelength is increased, the absorption threshold also increases. This applies to the optical propertie
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This paper introduces the Multistep Modified Reduced Differential Transform Method (MMRDTM). It is applied to approximate the solution for Nonlinear Schrodinger Equations (NLSEs) of power law nonlinearity. The proposed method has some advantages. An analytical approximation can be generated in a fast converging series by applying the proposed approach. On top of that, the number of computed terms is also significantly reduced. Compared to the RDTM, the nonlinear term in this method is replaced by related Adomian polynomials prior to the implementation of a multistep approach. As a consequence, only a smaller number of NLSE computed terms are required in the attained approximation. Moreover, the approximation also converges rapidly over a
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