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61.
Ziad Mansour Mohd Raihan Taha Zamri Chik 《Bulletin of Engineering Geology and the Environment》2009,68(1):97-106
Problems have occurred with dykes constructed on the Lisan Marl to retain brine pumped from the Dead Sea, which is chemically
processed to produce potash. In this study the engineering behavior, collapse potential and compressibility of the Lisan Marl
were assessed by undertaking laboratory tests with both natural, distilled water and brine as the media. The results showed
that the liquid limit and fine particles increased when the soil was mixed with fresh/distilled water compared with brine
water. The soil can be classified as highly compressible with a low undrained shear strength. In terms of collapsibility,
the soil could be classified as slightly collapsible upon inundation with distilled water and moderately collapsible when
soaked in Dead Sea brine. The results are important when determining the height and nature of the dykes.
相似文献
62.
A novel methodology for the solvent free auto-oxidation of methylbenzenes under mild conditions is disclosed. The new scheme is based on a combination of metallic salt (cobalt chloride) and a quaternary ammonium phase transfer catalyst (didecyldimethylammonium bromide) which together form a complex soluble catalyst in the organic phase. Major reaction parameters are studied and optimized and the procedure is applied for the conversion of several substituted toluenes to the corresponding benzoic acids in excellent isolated yields. 相似文献
63.
Microalloyed steels are characterised by their mechanical properties. Nowadays, they are used in a wide range of applications. The convenience and simplicity of hardness tests permit to obtain economically and rapidly information on the structure of steels and control their treatments. This study has been carried out to derive equations for prediction of the mechanical properties of microalloyed steels by hardness measurement. With this objective, V‐ and Ti‐microalloyed plain carbon steel bars were melted, hot rolled, heat treated and machined for the measurement of their mechanical properties and to reach a correlation between both ultimate tensile strength, yield strength and uniform elongation and Vickers hardness. The obtained data were treated using different mathematical fittings. They are mathematically treated as groups according to the heat treatment processes and as one group. The derived equations show good agreement with each other and with most of the little relations found in the literature. General equations for deducing mechanical properties values from the easily measured Vickers hardness values were derived. The equations derived from one group without regarding the treatment processes are more reliable. 相似文献
64.
Mohamed A. Taha Nahed A. El-Mahallawy Rawia M. Hammouda Sherif I. Nassef 《Journal of Coatings Technology and Research》2010,7(6):793-800
Although magnesium alloys have the advantage of high specific strength, they have poor atmospheric corrosion resistance. An
important method of improving the corrosion resistance is by applying a coating layer. In this work, the physical vapor deposition
(PVD) technique is used for coating a magnesium (Mg) AZ31 sheet substrate with a thin layer of high purity aluminum (Al) and
Al–12.6% Si. Aluminum is expected to be suitable as a coating layer on Mg sheets, due to its corrosion resistance and its
formability. Before coating, the substrate was subjected to several consecutive surface preparations, including sand-blasting,
mechanical grinding, mirror-like polishing, ultrasonic etching, and finally ion etching by magnetron sputtering (MS). PVD
coating was conducted using a PVD machine with max electron beam power and voltage of 100 kW and 40 kV, respectively. This
was either with or without plasma activation, and with variable substrate speeds ranging between 10 and 70 mm/s. During MS
ion etching and coating, the substrate temperature increased. The substrate temperature increased with the application of
plasma activation and with lower substrate speeds. The coating-layer thickness varied inversely with substrate speed. A thinner
coat with finer morphology was obtained in the case of plasma activation. Other results included coating layer characteristics,
diffusion between the AZ 31 substrate and the Al coating layer, adhesion of the coating layer to the substrate, and corrosion
resistance by a humidity test. 相似文献
65.
Muhammad H. Alu'datt Taha Rababah Mohammad N. Alhamad Ghaid J. Al-Rabadi Carole C. Tranchant Ali Almajwal 《Critical reviews in food science and nutrition》2018,58(18):3209-3218
ABSTRACTPhenolic phytochemicals have become of interest due to their therapeutic potential, particularly with regards to their anti-cancer, anti-inflammatory, hypolipidemic, and hypoglycemic properties. An evolving area of research involving phenolics in foods and their products pertains to the functional, biological, and nutritional consequences resulting from the binding between certain phenolic compounds and the macronutrient and micronutrient constituents of foods. The goal of this review is to provide a summary of studies investigating endogenous phenolic interactions with major components in food systems, including carbohydrates, proteins, lipids, minerals and vitamins, with a focus on the phenolic compounds and nutrients in oil-bearing plants. Another major objective is to provide a comprehensive overview of the chemical nature of phenolic interactions with food constituents that could affect the quality, nutritional and functional properties of foods. Such information can assist in the discovery and optimization of specific phenolic complexes in plant-based foods that could be utilized towards various applications in the food, nutraceutical and pharmaceutical industries. 相似文献
66.
67.
Electrical capacitance volume tomography (ECVT) is a recently-developed technique for real-time, non-invasive 3D monitoring of processes involving materials with strong contrasts in dielectric permittivity. This work is first application of the method to visualization of water flow in soil. We describe the principles behind the method, and then demonstrate its use with a simple laboratory infiltration experiment. 32 ECVT sensors were installed on the sides of an empty PVC column. Water was poured into the column at a constant rate, and ECVT data were collected every second. The column was then packed with dry sand and again supplied with water at a constant rate with data collected every second. Data were analyzed to give bulk average water contents, which proved consistent with the water supply rates. Data were also analyzed to give 3D images (216 voxels) allowing visualization of the water distribution during the experiments. Result of this work shows that water infiltration into the soil, wall flow, progress of the unstable wetting front and the final water distribution are clearly visible. 相似文献
68.
Walid M. Ibrahim Najah Abu Ali Hossam S. Hassanein Abd‐Elhamid M. Taha 《Wireless Communications and Mobile Computing》2016,16(18):3316-3331
Deployments over large geographical areas in the Internet of Things (IoT) pose a major challenge for single‐hop localization techniques, giving rise to applications of multi‐hop localizations. And while many proposals have been made on implementations for multi‐hop localization, a close understanding of its characteristics is yet to be established. Such an understanding is necessary, and is inevitable in extending the reliability of location based services in IoT. In this paper, we study the characteristics of multi‐hop localization and propose a new solution to enhance the performance of multi‐hop localization techniques. We first examine popular assumptions made in simulating multi‐hop localization techniques, and offer rectifications facilitating more realistic simulation models. We identify the introduced errors to follow the Gaussian distribution, and the estimated distance follows the Rayleigh distribution. We next use our simulation model to characterize the effect of the number of hops on localization in both dense and sparse deployments. We find that, contrary to common belief, it is better to use long hops in sparse deployments, while short hops are better in dense deployments – despite the traffic overhead. Finally, we propose a new solution that decreases and manages the overhead generated during the localization process. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
69.
Taha Mansouri Alireza Farasat Mohammad B. Menhaj Mohammad Reza Sadeghi Moghadam 《Expert systems with applications》2011,38(5):4866-4874
This paper presents a new individual based optimization algorithm, which is inspired from asexual reproduction known as a remarkable biological phenomenon, called as asexual reproduction optimization (ARO). ARO can be essentially considered as an evolutionary based algorithm that mathematically models the budding mechanism of asexual reproduction. In ARO, a parent produces a bud through a reproduction operator; thereafter the parent and its bud compete to survive according to a performance index obtained from the underlying objective function of the optimization problem; this leads to the fitter individual. ARO adaptive search ability along with its strength and weakness points are fully described in the paper. Furthermore, the ARO convergence to the global optimum is mathematically analyzed. To approve the effectiveness of the ARO performance, it is tested with several benchmark functions frequently used in the area of optimization. Finally, the ARO performance is statistically compared with that of an improved genetic algorithm (GA). Results of simulation illustrate that ARO remarkably outperforms GA. 相似文献
70.
Ahmad A Hamza Taha ZN Sokkar Kermal A El‐Farahaty Mohammed I Raslan 《Polymer International》2010,59(7):1021-1030
A creep device attached to an automated multiple‐beam Fizeau system in transmission was modified with a designed digital ruler. This device allows on‐line measurements of fibre length during creep experiments in terms of an analogue voltage value. The influence of sustained stress values on creep deformation and optical properties (n||, n? and Δn) for polypropylene (PP) fibres was studied interferometrically. The opto‐viscoelastic properties of PP fibres were determined for three different values of constant applied stress of 11.536, 18.717 and 25.905 MPa, at room temperature. Also, the variations of the cross‐sectional area and Poisson's ratio were studied during creep extensions. The compliance curves were obtained as a function of both time and applied stresses. Empirical formulae are suggested to describe the creep compliance curves for PP fibres, and the constants of these formulae were determined and described at each applied stress. A Kelvin chain was used to model the mechanical behaviour of the PP fibres under study. The effect of strain on the mean refractive indices, orientation function density and crystallinity was investigated as a result of the recorded data. Microinterferograms are given for illustration. The modified creep device with the designed digital ruler enables one to obtain instantaneous automatic accurate recording of fibre length values during creep experiments. Calculation of refractive indices, orientation function and crystallinity shows a difference in material behaviour at small stresses from that at higher stresses which may be attributed to different strain rates caused by different stresses. Copyright © 2010 Society of Chemical Industry 相似文献