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.
General Directorate of Surveying is considered one of the most important sources of maps in Iraq. It produced digital maps for whole Iraq in the last six years. These maps are produced from different data sources with unknown accuracy; therefore, the quality of these maps needs to be assessed. The main aim of this study is to evaluate the positional accuracy of digital maps that produced from General Directorate of Surveying. Two different study areas were selected: AL-Rusafa and AL-Karkh in Baghdad / Iraq with an area of 172.826 and 135.106 square kilometers, respectively. Different statistical analyses were conducted to calculate the elements of positional accuracy assessment (mean µ, root mean square error RMSE, mini
... Show MoreThe research aims to identify the social control among kindergarten department students. In order to achieve the objective of the research, a sample of (400) female students: (200) from Baghdad University / Faculty of Education for women and (200) from Mustansiriyha University / Faculty of Basic Education were chosen randomly.
The researchers designed a tool to measure the social control of the study sample. It was exposed to group of specialists in the educational and psychological sciences, measurement and evaluation. In addition to specialists in kindergartens. Two indicators of validity were used. The Alpha-Cronbach method, Pearson correlation coefficient, and independent samples t-test were used to analyze the c
... Show Morenumerical study is applied to the mercury-argon mixture by solving the boltzman transport equation for different mixture percentage.
Background: Laparoscopic cholecystectomy (LC) has become the standard treatment for symptomatic cholelithiasis. Bile duct injury and accidental gallbladder perforation with spillage of bile and stone are common complications of LC. This study was carried out to assess the early complications of gallbladder perforation during LC, and identify the risk factor of that perforation.
Objectives: to evaluate the early complications which may occur after the perforation of the gallbladder during laparoscopic cholecystectomy and to determine the risk factors which are associated with the perforation of the gall bladder.
Subjects and methods: A prospective comparative study o
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There were signs of the first civilization known to humanity for more than 6000 years BC in the north of Iraq have disappeared this civilization to appear after 500 years in southern Iraq, the Sumerian civilization, which was considered as the opinion of scientists or civilizations, exceeds the impact to Asia and the countries that had been in contact (Sumerians) and see them today in other towns and villages. In subsequent periods of time appeared distinct personalities to their nature, religious, social, special clothing with clothes seem especially long. And usually dress is made from raw wool material making them in the Sumerian era. Put the garment on the body and leaves the top of the right shoulder with the survival of an ope
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Research summary
Praise be to God, Lord of the worlds, and prayers and peace be upon the one who was the most eloquent of people in language and the most eloquent of them in eloquence, our Master Muhammad (peace and blessings of God be upon him).
To proceed... There is no doubt that many studies have preceded me in talking about chalk, each according to his own destination and view, and what I do not deny is that I benefited a lot from it, and it provided me with a lot of valuable information, and I liked to be one of those study pens, trying as much as possible To add something new and different in the study, far from similarity and repetition. Especially in the Abbasid study.
The babble in the Abbasid society was d
... Show MoreMachine learning (ML) is a key component within the broader field of artificial intelligence (AI) that employs statistical methods to empower computers with the ability to learn and make decisions autonomously, without the need for explicit programming. It is founded on the concept that computers can acquire knowledge from data, identify patterns, and draw conclusions with minimal human intervention. The main categories of ML include supervised learning, unsupervised learning, semisupervised learning, and reinforcement learning. Supervised learning involves training models using labelled datasets and comprises two primary forms: classification and regression. Regression is used for continuous output, while classification is employed
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Objective:
This study aims to asses the patients' compliance with essential hypertension in respect to antihypertensive
medications, follow-up, dietary pattern and health habits, to identify the associated long-term complications, and
to find out the relationship between patient's compliance, and demographic characteristics such as age, gender,
level of education, and duration of disease.
Methodology:
A descriptive study was carried out in Nasiriyah Teaching Hospital to achieve presented objectives .
Results:
The results of the study revealed that there were a significant association between educational level and total
patient's compliance, a significant association was found between the duration of disease and
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