47 research outputs found

    PERFORMANCE EXAMINATION OF AES ENCRYPTION ALGORITHM WITH CONSTANT AND DYNAMIC ROTATION

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    ABTRACT Lately, the Rijndael algorithm has been standardized by the NIST as the Advanced Encryption Standard (AES). This makes AES an essential and necessary data-protection mechanism for federal agencies in the US and other countries. In AES, rotation occurs in key expansion, ciphering, and deciphering. Rotation is vital for confusion and diffusion, which play an important role in any cryptography technique. Confusion and diffusion make breaking the key complex and difficult. This paper studies the effect of reconfiguring the structure of AES, especially replacing constant rotation with variable rotation. The resulting twin cipher is called Dynamic Rotation for Advanced Encryption Standard (DRAES). DRAES with variable rotation increases the complexity of the algorithm, and thus, increases the time consumed for brute-force attacks. We measured the diffusion of AES and DRAES algorithms. DRAES reached acceptable level of diffusion faster than AES

    Nano silica particles loaded with CYANEX-921 for removal of iron(III) from phosphoric acid

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    303-310A simple route for preparation of organically modified spherical silica (SiO2) nanoparticles with CYANEX 921 has been discussed. These modified particles has been used to remove Fe3+-SCN complex from 9M phosphoric acid. SEM, XRD, IR and EDS have been used to Characterized the powder in its several stages. The effect of SiO2 weight, thiocyanate concentration, initial Fe (III) concentration, H3PO4 concentration, stirring time, temperature and loaded SiO2 weight have been used to study the removal percent. The loaded silica succeeded in removal of 70% of Fe (III). Langmuir isotherm model well fit the experimental data with maximum sorption capacity 45.45 mg/g. The reaction kinetic is found to follow the pseudo second order kinetic model the adsorption reaction shows exothermic behavior

    Eating Habits and Lifestyles among a Sample of Obese Working Egyptian Women

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    BACKGROUND: The fundamental cause of obesity and overweight is an energy imbalance between calories consumed and calories expended.AIM: To figure out food habits and different lifestyle pattern among a sample of Egyptian females working at the National Research Centre.METHODS: A cross-sectional, descriptive study, including 138 overweight and obese Egyptian females (BMI ≥ 25 Kg/m2); working at the National Research Centre; was done. A specific questionnaire was used to gather information regarding lifestyle including dietary habits, physical activity and sedentary behaviour. RESULTS: The prevalence of overweight among the studied subjects was 27%, while that of obesity was 38%. Missing and or infrequent intake of breakfast at home, frequent consumption of snacks, low serving per day of fruits and vegetables with frequent consumption of sweets, fried food, eating while watching TV and sedentary behaviour were all predictors of obesity and overweight among the current sample.CONCLUSION: The present study identified several lifestyle factors and improper dietary habits associated with overweight and obesity among Egyptian females. There is a great need to change these habits to avoid the increasing risk of obesity. A national plan of action to overcome obesity is urgently needed to reduce its economic and health burden

    Image cytometric analysis of p53 and mdm-2 expression in primary and recurrent mucoepidermoid carcinoma of parotid gland: immunohistochemical study

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    <p>Abstract</p> <p>Aims and Objectives</p> <p>This study aims to analyze immunocytochemically p53 aberrant expression and mdm-2 expression in primary and recurrent mucoepidermoid carcinoma (MEC) of parotid gland and to ascertain if expression of these markers correlates with tumor behavior, clinical outcome, histological grade and local recurrence.</p> <p>Methods</p> <p>20 cases histologically diagnosed as primary MEC with different grades were included in the study. Out of 20 cases, 7 were classified as grade I, 8 as grade II and 5 as grade III. Immunohistochemical staining of these 20 primary cases as well as 6 recurrent cases with anti-p53 and anti-mdm-2 antibodies was carried out. Area fraction of immunopositivity was estimated by image analysis software.</p> <p>Results</p> <p>16/20 primary cases were p53 +ve (80%). The p53 positive cases included 3 cases classified as grade (I), 8 cases as grade (II) and 5 cases as grade (III). All 6 recurrent cases were p53 +ve. On the other hand, 14/20 primary and only 2/6 recurrent cases were mdm-2 +ve. The mdm-2 +ve primary cases included 2 classified as grade (I), 7 as grade (II) and 5 as grade (III). 12 primary MEC showed co-expression of both p53 and mdm-2 of which 2 cases showed local recurrence.</p> <p>Conclusions</p> <p>these data suggested that expression of p53 and mdm-2 in primary and recurrent MEC correlates with the high histological grade. P53 aberrant expression is not only considered as an early event in MEC carcinogenesis but also correlates to tumor behavior and local recurrence. Mdm-2 overexpression is correlated to pathogenesis of MEC. However, no strong evidence was found between mdm-2 expression and MEC local recurrence.</p

    Management of saltwater intrusion in coastal aquifers using different wells systems: a case study of the Nile Delta aquifer in Egypt

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    This is the author accepted manuscript. The final version is available from Springer via the DOI in this recordSaltwater intrusion (SWI) is a type of pollution that adversely affects the quality of groundwater in coastal aquifers. The Nile Delta aquifer (NDA) in Egypt contains a large amount of freshwater. Increasing abstraction from the aquifer and sea level rise have led to an increase in SWI, which has reached up to 100 km inland. Therefore, practical measures are required to prevent further SWI. This study aims to identify an optimal well system to manage the intrusion of saline water in NDA using a number of management systems, including pumping of brackish water, aquifer recharge, and abstraction of the freshwater. SEAWAT code is used to simulate SWI in the aquifer considering different scenarios of pumping and sea level rise. Four scenarios are used to control SWI, including: decreasing pumping from the aquifer, increasing recharge using treated waste water, increasing abstraction of brackish water for desalination, and a combination of these systems. The results showed that increasing recharge could lead to greater retardation of SWI (19.5%) than decreasing pumping (6.2%) and abstraction of brackish water (5.9%). However, a combined well system of pumping, recharge and abstraction is shown to be a more effective tool to control SWI in coastal aquifers, with retardation percentage of 21.3%.Water and Water Structures Engineering, Faculty of Engineering, Zagazig Universit

    LTE, LTE-advanced, and WiMAX: towards IMT-advanced networks

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    Preparation, Properties, and Characterization of ZnS Nanoparticles

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    In this paper, the structural, microstructural, thermal, electrical, and dielectric properties of synthesized ZnS nanoparticles are studied using the co-precipitation technique. The precipitate was characterized using X-ray diffraction (XRD). Characterization was confirmed via formation of a single-phase cubic nanocrystal line structure. The crystalline size was obtained using three different models. Information regarding thermal transition such as melting, oxidation, and crystallization was revealed using differential scanning calorimetry and thermogravimetry (DTG/TG). Transmission electron microscopy (TEM) images were obtained to explore the stability, morphology, and other properties of the ZnS nanoparticles. Regarding the crystallite size of the prepared ZnS, different techniques were utilized to estimate the crystallite size, and the calculations confirmed the formation of the ZnS in nanocrystal form. The electrical properties of the synthesized nanocrystals were measured at different temperatures (293–373 K) over a wide range of frequencies from about (50 Hz up to 5 MHz). Regarding the frequency dependence of the A.C conductivity and the Activation energy (Ea) was found to decrease as the frequency increase

    Effect of Benzotriazole on the Hydrogen Absorption by Iron

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