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
Objectives: Successful endodontic treatment outcome requires effective shaping and cleaning of root canals. This study aims to evaluate the smear layer removal after continuous chelation (CC) ) NaOCL\HEDP( and sequential chelation (SC) )NaOCL\EDTA( and their influence on the push-out bond strength (POBS) of Bio-C sealer. Materials and Methods: Palatal roots of the maxillary first molar (n=72) were divided into four groups (n=18) as follows: 3% NaOCL, SC: 3% NaOCL followed by 17% EDTA, CC: 3% NaOCL \9% HEDP and Distilled water. Thirty-two roots (n=8/group) were split longitudinally for smear layer evaluation using SEM. Forty roots were obturated with Guttapercha and Bio-C sealer using a single cone technique. Thre
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Abstract
Agricultural Bank is an important source of funding Specialist His role in lending to farmers, it imposes a great job in providing the necessary head for any developmental process in the agricultural sector money. The ACB of ancient Iraqi banks, and that because of its importance to the advancement of the national economy and contribute to the development and regulation of the economic sector through the support and the assignment of the Iraqi agricultural sector in various agricultural activities because it is responsible
for the process of granting agricultural loans to farmers bank.
The aim of the internal control in the agricultural banks to
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The researcher is one of the workers in university sports student activities, as he noticed that there is a diversity in the use of leadership patterns among managers of student activities in Iraqi universities between one director and another, which leads to the impact of these leadership styles on performance, positive or negative, in the level of human relations and the achievement of results. The researcher adopted the descriptive method in the survey method with relational relationships. The research sample consisted of (184) sports coaches who represent (27) universities and governmental and private colleges. To achieve the research objectives, the researcher used the Statistical Package for Social Sciences (Spss). To extract.statisti
... Show MoreThe paper aims to measure the impact of monetary policy on price stability , by testing the causal relationship between the money supply, inflation rate and the exchange rate , In order to prove that the inflation is a monetary phenomenon in the Iraqi economy , and that the exchange rate is controlled in the money supply , the money supply as an endogenous variable continued we found by using the standard tests to the existence of a single co-integration between the money supply and the rate of inflation and the money supply and the parallel exchange rate, This confirms the existence of a long-term relationship between the variables , It also confirmed the results of the vector error correctio
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natural and non-natural disasters, is an environmental challenges the society and the economy as well as a direct and indirect economic affect, and the units are part of the system overlapping among themselves and thus affected by external indicators, directly or indirectly, these direct effects appear in the destruction or damage inflicted by disasters in property , infrastructure , superstructure , accounting information systems and indirectly in the outcome of future business, comes research problem through access to accounting treatments issued by the Federal Office of financial supervision to address the damage caused by the disasters and prepare the missing financial accounts it turns out us that there is negligence of a nu
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Abstract
Personality is one of the most important elements that should be developed in university student. Thus, we have to develop the positive traits and neutralize the negative traits of students as well as we have to pay attention to the level of student achievement at the same time, the researcher designed a scale to measure the traits of study sample. The research come out with a number of recommendations and proposals, the most important of which Enhancing the positive characteristics of university students in order to reach them to the level of mature personality with mental health. Enhancing the positive role of the high level of achievement by motivating the stude
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The phonetic replacement is the process of putting a sound or a linguistic
syllable instead of another in one word that results in changing its meaning . It is one
way of vocabulary varionsness and discrimination because replacement among the
sounds of one expression and changing its image lead to change its meaning , and
accordingly , each replaced sound has its own linguistic value that distinguishes it . In
other words , the phonetic replacement is based on system of phonemic change
which is a general phenomenon in all languages . The linguistic system doesn’t stand
straight for word unless it is based on different standards that work on variousness ,
assortment and relating the phonetic change wi