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
In this study NiO - CoO bimetallic catalysts are prepared with two Ni/Co ratios (70:30 and 80: 20) using the precipitation method of nitrate salts. The effects of Ni /Co ratio and preparation methods on the catalyst are analyzed by using different characterization techniques, i.e. atomic absorption (AA) , XRD, surface area and pore volume measurements according to the BET method . The results indicate that the best catalyst is the one containing the percentage of Ni :Co ( 70 : 30 ). Experiments indicate that the optimal conditions to prepare catalyst are stirring for three hours at a temperature of 60oC of the preparation , pH= (8-9) , calcination temperature at 400oC for two hours
... Show MoreThe present study addressed "Performance Appraisal of Human Resource Management and Its Effect on Achieving the Organizational Success", for the topics of performance appraisal of human resource management and the organizational success gained an increasing interest being relatively important and modern topics which had a great effect on the future of organizations.
The study aimed at revealing the pattern of appraising the performance of human resource management for the study sample, and whether it was qualified to lead the ministry towards the organizational success, for this purpose two main hypotheses were formulated: 1) there is a positive significant correlation between both variables: performanc
... Show MoreIn this paper, a description of a design for new DES block cipher, namely DES64X and DES128X. The goals of this design, a part of its security level, are large implementation flexibility on various operating systems as well as high performances. The high level structure is based on the principle of DES and Feistel schema, and proposes the design of an efficient key-schedule algorithm which will output pseudorandomsequences of subkeys. The main goal is to reach the highest possible flexibility, in terms of round numbers, key size, and block size. A comparison of the proposed systems on 32-bit, 64-bit operating system, using 32-bit and 64-bit Java Virtual Machine (JVM), showed that the latter has much better performance than the former.
... Show MoreThe effect of using three different interpolation methods (nearest neighbour, linear and non-linear) on a 3D sinogram to restore the missing data due to using angular difference greater than 1° (considered as optimum 3D sinogram) is presented. Two reconstruction methods are adopted in this study, the back-projection method and Fourier slice theorem method, from the results the second reconstruction proven to be a promising reconstruction with the linear interpolation method when the angular difference is less than 20°.
Experiment Factorial conducted with two factor in field texture silt clay loam soil, the first factor were Two Rotavator plow which different in number of rotary blades on flanges, weight, width, made and type, the second factor were four speeds tractor 2.62, 5.10, 7.55, 9.23 km/hr to compare performance two Rotavator under depth 12 cm and knowledge slippage, distance between beat blades, practical productivity, disturbed soil volume, percentage of the soil clods which have diameter less than 5 cm under complete block design with three replications using Least Significant Design 0.05. Results showed Galucho Rotavator recorder the higher practical productivity 0>7089 ha/hr, disturbed soil volume 809.8 m3/hr, percentage of the soil clods 96.1
... Show MoreAn experimental work has been conducted on wall attachment fluidics amplifiers, one of them to study the effect of output pressure or load on the amplifier performance. The output load has been simulated as a piston connected to the device output and the piston can be loaded accordingly. The results shows that the output volume flow rate increases as the supply pressure increases under different load and the output pressure remains constant as the supply pressure increases under constant load.
Lighting is a very important element of treatment if the color contains many imaging system (digital cameras) and the unit of light and the light within these units are not strong , but usefel when the light is low , in different lighting intensities conditions image quality will not persist good enough and image may become dark or slightly exposed to light which leads to lower the details in image where we can not modify contrast or light ness to compensate thr decrease without losing the light and dark deatials . So we went in this research to study the variation colored texts written on the painting and lighting cases of non –regular ( a few) and different distances . As the diversity of these texts written on the board a
... Show MoreThis research aims to demonstrate the nature and concept of the Corona pandemic, its implications for the global economy, and the management and performance of companies in particular. Additionally, the research intends to measure the impact of the Corona pandemic on companies' financial performance. Listed on the Iraqi Stock Exchange, which has finished compiling its year-end financial statements for 2019-2020. The investigation arrived at several findings, the most significant of which was that most businesses were not prepared for such a crisis technologically or to develop human resources to deal with this pandemic. In addition, most companies experienced a decrease in their financial performance as a direct result of the Corona pandemi
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