The present study reports the effect of temperature and liquid hourly space velocity (LHSV) on the cumene cracking reaction rate and selectivity by using a laboratory continuous flow unit with fixed bed reactor operating at atmospheric pressure. The prepared HX zeolite was made from Iraqi kaolin with good crystallinity .The activity and selectivity of prepared HX-zeolite was compared with standard HY zeolite and HX zeolite catalysts in the temperature range of 673-823K and LHSV of 0.7-2.5 h-1 . It was found that the cumene conversion increases with increasing temperature and decreasing LHSV at 823K and LHSV of 0.7 h-1 the conversions 65.32, 42.88 and 59.42 mol% for HY, HX and prepared HX catalysts respectively and at LHSV of 2.5 h-1 and the same temperature the conversions decrease to 29.24, 12.53 and 22.89 mol%, respectively .It also found that the benzene yield increases with increasing temperature at 823K and LHSV of 0.7 h-1 the benzene yields were 58.79, 38.56 and 54.56 mol% for HY zeolite , HX zeolite and prepared HX zeolite, respectively and the selectivity to benzene is nearly constant over the studied temperatures range. The kinetics of cumene cracking ( the kinetics parametersrate constant )and activation energy are used in this study to characterize differences between various catalysts. The reaction was found to be first order with activation energy equal to 78.58 , 89.10 and 97.77 kJ/mol for HY, prepared HX and HX , respectively
The purpose of this research is to determine the relationship between the strategic thinking and organizational change via the use of many statistical methods such as Simple linear regression equation. The 80% of the hypotheses of correlation and influence were established, and the research was reached a number of conclusions. Including the fluctuation of the level of strategic thinking capabilities in the sample surveyed. Although, there are certain levels, but an organization of this importance need to be higher. Based on these conclusions, the researcher has made some recommendations to address the findings of the research. Reflexión del pensamiento estratégico sobre el cambio organizacional Resumen El propósito de esta investigación
... Show MoreThe strategy of designing the covers of international magazines emerges as one of the expressive means that reflect the emotional and expressive aspects and employ them according to the spatial transformations and the struggles of globalization to usurp the intellectual, cultural, value and civilizational essence of man, which makes him vulnerable to psychological and spiritual alienation and becomes the abstract meaning of identity and culture, and the empowerment of cultural invasion and the control of consumer thought The contemporary globalist on the largest area and the globalization of the peoples of the world, and the study came in the first chapter: the general framework that includes the problem of the research to raise in our m
... Show MoreThe study was enriched by examining (Islamic Sharia’s position on the phenomenon of bullying) becausee bullying is a recurring aggressive behavior that Is one of the types of violence directed by a person or group of prsons; With the intent of deliberately harming and offending anotherr person or group of persons, It has several verbal, physical, electronIc or other formsforms Bullies may follow a policy of Ientimidation or intimidation, as well as ridicule; In order to belittle the victim .The study aims to know the Islamic Sharia ruling on bullying as a modern term for a content that Is as old as man, and the study reached several results, Including: Islam’s affirmation of the prohibition of this phenomenon In word, deed and gesture,
... Show MoreThis research aims to test the effect of strategic cohesion with its dimensions (organizational excitement, organizational casting, organizational synergy) as an independent variable on administrative excellence as a dependent variable in the Ministry of Planning, and through surveying several employees (general managers, heads of departments, and units managers). As a research community, and based on the importance of the research topic in the aforementioned research community. The researchers have adopted the descriptive-analytical using the questionnaire as the main data collection. 155 questionnaires were distributed, yet,114 of them were retrieved and 110 were used for final statistical analysis. The researchers used the relev
... Show MoreIn this paper we present the theoretical foundation of forward error analysis of numerical algorithms under;• Approximations in "built-in" functions.• Rounding errors in arithmetic floating-point operations.• Perturbations of data.The error analysis is based on linearization method. The fundamental tools of the forward error analysis are system of linear absolute and relative a prior and a posteriori error equations and associated condition numbers constituting optimal of possible cumulative round – off errors. The condition numbers enable simple general, quantitative bounds definitions of numerical stability. The theoretical results have been applied a Gaussian elimination, and have proved to be very effective means of both a prior
... Show MoreReceipt date:11/19/2020 acceptance date:10/1/2021 Publishing date:12/31/2021
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Human rights are one of the basic concepts of modern and contemporary times, and political thought as the origin of political science and its source of knowledge have impact in this science and its branches
... Show MoreIn this research, we present a nonparametric approach for the estimation of a copula density using different kernel density methods. Different functions were used: Gaussian, Gumbel, Clayton, and Frank copula, and through various simulation experiments we generated the standard bivariate normal distribution at samples sizes (50, 100, 250 and 500), in both high and low dependency. Different kernel methods were used to estimate the probability density function of the copula with marginal of this bivariate distribution: Mirror – Reflection (MR), Beta Kernel (BK) and transformation kernel (KD) method, then a comparison was carried out between the three methods with all the experiments using the integrated mean squared error. Furthermore, some
... Show MoreThis study aims to clarify areas of using information technology in accounting and its impact on the profession of auditors by reviewing the concept, types, areas and the importance of information technology and its implications on the audit profession as well as to clarify the extent of contribution of information technology in developing of procedures of the audit profession and what its requirement, also this study aims to enhance the theoretical side by identifying the views of a sample of auditors in Arab countries selected (Iraq, Syria, Jordan), for the extent of using of information technology in their work and level of their perception for the importance of that
The research aims to find out the impact of Lee’s cognitive strategy on the achievement of fifth-grade literary students in the module of history. The research community consists of the secondary female day schools of Al-Karkh Al-Oula Directorate General of Education. The size of the research sample comprises (45) female students of the fifth grade of the literary brunch, (21) students for the experimental group and (24) students for the control group. The researchers have chosen an experimental design with partial control to suit the current research and its goal. They used a unified tool to measure the achievement of female students, which consisted of (50) items characterized by sincerity and they extracted the stability of t
... Show MoreThe topic of the research aims to consolidate the concept of fair value, and then to identify the international financial reporting standard and its role in the application of fair value in the Iraqi local environment and the possibility of using it in determining the value of the company. To achieve the goal of the research, the analytical approach was adopted for the data and information that was obtained by the researcher by conducting interviews with a number of bank and department managers in a sample of Iraqi banks registered in the Iraq Stock Exchange, and then analyzed by adopting some quantitative financial methods. The researchers reached a set of conclusions, the most important of which was the impact of fair value accoun
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