Coupling to a receiving aperture from a random medium at millimetric wavelengths

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Effect of Foundation Deformations on the Damage of a Masonry Villa (Case History)

Cracks in the masonry walls of a one storey villa due to foundation deformations are investigated in this paper. In spite of the fact that the soil formation in the site was found to be almost uniform, hogging deformation profile took place in the strip foundation due to unequal loading. Analysis of the walls together with their supporting soil, as one integrated system, showed that very small foundation deformation can produce tensile stresses in the wall higher than its tensile strength. Repair of the cracks was proposed and carried out successfully

Feature Selection Approach based on Firefly Algorithm and Chi-square

Dimensionality problem is a well-known challenging issue for most classifiers in which datasets have unbalanced number of samples and features. Features may contain unreliable data which may lead the classification process to produce undesirable results. Feature selection approach is considered a solution for this kind of problems. In this paperan enhanced firefly algorithm is proposed to serve as a feature selection solution for reducing dimensionality and picking the most informative features to be used in classification. The main purpose of the proposedmodel is to improve the classification accuracy through using the selected features produced from the model, thus classification errors will decrease. Modeling firefly in this research appears through simulating firefly position by cell chi-square value which is changed after every move, and simulating firefly intensity by calculating a set of different fitness functionsas a weight for each feature. K-nearest neighbor and Discriminant analysis are used as classifiers to test the proposed firefly algorithm in selecting features. Experimental results showed that the proposed enhanced algorithmbased on firefly algorithm with chi-square and different fitness functions can provide better results than others. Results showed that reduction of dataset is useful for gaining higher accuracy in classification

الميزة النسبية لمصر في إنتاج اللحم واللبن مــن الجاموس

As Egypt faces limited agricultural resources, either land acreage or water sources for irrigation, it is necessary to focus on either cows or buffaloes to produce red meat and milk under the existing intensive agricultural system. This study conducted a comparative analysis of the technical and economic criteria to investigate the comparative advantage of Egypt in producing meat and / or milk from buffaloes in comparison with local cows and both cows and dairy buffalo in other countries. The comparison used milk equivalent of 4% fat to adjust the high fat percent in buffalo milk. The study used the published time series data the research studies based upon field sample surveys. The technical criteria included the percentage of milking animals, milk yield and milk composition, as well as the feed utilization efficiency. The economic criteria included the role of buffalo in generating labor employment, poverty alleviation and improving food security in rural areas, in addition to the costs of production per ton and per 100 grams of protein and the farm price ratio. All criteria have provided evidences that Egypt has comparative advantage in raising buffalo for milk production. The study recommended a development programs for buffalo production in Egypt. It is basically, depends upon vertical expansion rather than horizontal which is not feasible under limited water and agricultural land resources. Therefore the genetic improvement of Egyptian buffalo population, for milk production should be the main approach, using artificial insemination and supported by the reform of the milk marketing system and improving the Egyptian buffalo reproductive performances

A detailed hydrothermal investigation of a helical micro double-tube heat exchanger for a wide range of helix pitch length

The present study was numerically inquired the heat transfer performance and fluid flow characteristic of a helical micro double-tube heat exchanger (HMDTHX) using the finite volume method. The tube length was considered to be constantly equal to 30 mm, and 12 different configurations were modeled by changing in turn number and pitch length (P) for Reynolds numbers of 50, 100, 150, and 200. The findings indicated that the heat transfer would enhance by applying any helix angle in the straight tube. However, it had an optimum point which varied by Reynolds number (Re). Rising Re caused overall heat transfer coefficient (OHTC), pressure drop, and pumping power augment for all cases. Increasing P in overall reduced OHTC, pressure drop, and pumping power which had different maximum points between P = 0.5 to 3. Maximum overall heat transfer coefficient (OHTC) enhancement was equal to 45% for Re = 200 and P = 2. Also, maximum effectiveness was 11.5% for P = 2 and Re = 200. Moreover, a 42% maximum increment was achieved for pressure drop, pumping power, and friction factor at Re = 200 and P = 2. Shear stress for Re = 100 to 200 showed that the values are almost the same for P = 0.5 and 1. Then by increasing P, the shear stress decreases. While, for Re = 50, a maximum is seen at P = 2. The temperature distribution was indicated that the maximum temperature of the straight tube and helical tube are the same, but the difference is in the average temperature, which was 3.2 K between straight and helical tubes. Finally, by investigating the velocity contour, it was determined that a secondary flow through the HMDTHX, affected by centrifugal force, was existed, enhancing the fluid flow turbulency and heat transfer rate

Chitosan Modification of Adenovirus to Modify Transfection Efficiency in Bovine Corneal Epithelial Cells

BACKGROUND: The purpose of this study is to modulate the transfection efficiency of adenovirus (Ad) on the cornea by the covalent attachment of chitosan on adenoviral capsids via a thioether linkage between chitosan modified with 2-iminothiolane and Ad cross-linked with N-[gamma-maleimidobutyryloxy]succinimide ester (GMBS). METHODOLOGY/PRINCIPAL FINDINGS: Modified Ad was obtained by reaction with the heterobifunctional crosslinking reagent, GMBS, producing maleimide-modified Ad (Ad-GMBS). Then, the chitosan-SH was conjugated to Ad-GMBS via a thioether bond at different ratios of Ad to GMBS to chitosan-SH. The sizes and zeta potentials of unmodified Ad and chitosan-modified Ads were measured, and the morphologies of the virus particles were observed under transmission electron microscope. Primary cultures of bovine corneal epithelial cells were transfected with Ads and chitosan-modified Ads in the absence or presence of anti-adenovirus antibodies. Chitosan modification did not significantly change the particle size of Ad, but the surface charge of Ad increased significantly from -24.3 mV to nearly neutral. Furthermore, primary cultures of bovine corneal epithelial cells were transfected with Ad or chitosan-modified Ad in the absence or presence of anti-Ad antibodies. The transfection efficiency was attenuated gradually with increasing amounts of GMBS. However, incorporation of chitosan partly restored transfection activity and rendered the modified antibody resistant to antibody neutralization. CONCLUSIONS/SIGNIFICANCE: Chitosan can provide a platform for chemical modification of Ad, which offers potential for further in vivo applications