Accurate description of thermodynamic, structural, and electronic properties for bulk and surfaces of ceria (CeO2) necessitates the inclusion of the Hubbard parameter (U) in the density functional theory (DFT) calculations to precisely account for the strongly correlated 4f electrons. Such treatment is a daunting task when attempting to draw a potential energy surface for CeO2-catalyzed reaction. This is due to the inconsistent change in thermo-kinetics parameters of the reaction in reference to the variation in the U values. As an illustrative example, we investigate herein the discrepancy in activation and reaction energies for steps underlying the partial and full hydrogenation of acetylene over the CeO2(111) surface. Overall, we find that both activation and reaction energies positively correlate with the increase in the U value. In addition to benchmarking against more accurate theoretical methodologies, we suggest that U values are better optimized against kinetics modelling of experimentally observed profiles of products from the catalytic-assisted system of reactions.
Background: White spot lesion is the first visible sign of dental caries that is characterized by demineralized lesion underneath an intact surface. Several studies demonstrated that they could be treated using noninvasive techniques like the use of fluoride or casein phospho-peptide and amorphous calcium phosphate. Improvement in aesthetic outcomes by covering the demineralized enamel is one of the advantages of the use of resin infiltration and opal-ustre microabrasion, which are two new techniques that had been used for treatment of white spot lesion. The purpose of this study was to evaluate the impact of resin infiltration and microabrasion in the microhardness of the artificial white spot lesions at various depths. Material and method
... Show MoreThe purpose and goal of the research revolve around the diagnosis of intellectual capital as the logical indicator to study an effective human resource management practice and its influential role in determining the overall quality management of higher education institutions and scientific research in Baghdad.
To achieve the purpose of the research, an upgraded standard questionnaire was used to collect data and distribute it to the selected sample in a statistical manner from the study population of (5) institutions affiliated with the Ministry of Higher Education and Scientific Resear
... Show MoreLiterature on the use of the first-person pronoun in abstracts and conclusion sections of final-year projects is limited. In case of Algerian Master students, it is too scant. The present paper aims at filling this gap through a study concerned with students’ and engagement in their final projects (memoirs). This quantitative study examines the use of “we” and its various types, “our- us-I, my, the researcher” in memoirs chosen at random from the d-space portal of the University of Adrar, southern Algeria. Sixty-five papers, submitted in the fields of Linguistics or didactics between 2015 and 2020 and representing nearly half of the whole memoirs’ depository at the library’s d-space, constituted the corpus of study. The des
... Show MoreBirds of prey (Raptors) are top predator avian species that many migrate annually through Mesopotamian marshes in southern Iraq toward their wintering grounds in Arabia and Africa, while others are breeding residents; however, information on their current status is scarce. From January 2016 to April 2019, a total of 20 field expeditions were conducted in the geographical zone of the Mesopotamian marshes, wetlands of international importance. The survey covered the Central Marshes, Al-Hammar and Hawizeh Marsh. One of the objectives of the field surveys is to list the raptors species that wintering and/or migrating through the Mesopotamian marshes and to understand their current spatial and temporal distribution. In the present study, a to
... Show MoreIn this experimental and numerical analysis, three varieties of under-reamed piles comprising one bulb were used. The location of the bulb changes from pile to pile, as it is found at the bottom, center, and top of the pile, respectively.
In this research, damping properties for composite materials were evaluated using logarithmic decrement method to study the effect of reinforcements on the damping ratio of the epoxy matrix. Three stages of composites were prepared in this research. The first stage included preparing binary blends of epoxy (EP) and different weight percentages of polysulfide rubber (PSR) (0%, 2.5%, 5%, 7.5% and 10%). It was found that the weight percentage 5% of polysulfide was the best percentage, which gives the best mechanical properties for the blend matrix. The advantage of this blend matrix is that; it mediates between the brittle properties of epoxy and the flexible properties of a blend matrix with the highest percentage of PSR. The second stage
... Show MoreMatrix acidizing is a good stimulation process in which acid is introduced into the reservoir near the wellbore area via the wellbore or coil tubing. In the oil industry, formation damage is a prevalent problem. Bypassing wellbore damage by producing wormholes in carbonate reservoirs is the main purpose of acidizing the matrix of the formation. When doing lab tests, scientists are looking for a wormhole-inducing injection rate that can be used in the field. Meantime the ongoing works on the Ahdeb oil field's Mishrif reservoir, several reports have documented the difficulties encountered during stimulation operations, including high injection pressures that make it difficult to inject acid into the reservoir formation; and only a few
... Show MoreThe artistic process operates whether in general in all arts or specifically in one type of arts or one of the genres of arts types on the preoccupations of the pressing artistic references as the founder of the artistic work in the material formulations on the one hand and on the other hand as a translator to understand the artistic achievement in general and plastic art in particular and for the importance The researcher chose the title of her research tagged (the preoccupations of the pressing reference and its impact on the formations of postmodern arts).
The first chapter of the methodological framework deals with the problem of research, importance, objective, limits, and then terminology and its definition, and then the secon
Values are penetrating or interfering in the lives of individuals and groups and are connected to them in the sense of life itself, because they are closely linked to the motives of behavior, hopes and goals, and can be said that values are everything. The concept of values is one of the concepts that have received the attention of researchers from different disciplines. This has resulted in a kind of confusion and variation in use from one specialization to the other, and uses multiple uses within one specialization. Therefore, there is no uniform definition of values because they relate to individuals. Individuals differ in many things, such as perception,
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