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

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

The Effectiveness of a Program Based on Mathematical Communication on Conceptual Understanding and Mathematics Anxiety of Eighth-Grade Students فاعلية برنامج قائم على الاتصال الرياضي في الفهم المفاهيمي وقلق الرياضيات لدى طلبة الصف الثامن الأساسي في الاردن

Abstract: The present study aimed to investigate the effectiveness of a program based on mathematical communication in conceptual understanding and the level of mathematics anxiety among eighth grade students. The study sample consisted of (54) students of eighth grade students enrolled in two schools in the town of Ala\u27al belonging to the Directorate of Education of the brigade of Irbid during the second semester of the academic year 2017-2018, distributed equally to two groups (experimental, control). Experimental group subordinated to a program based on mathematical communication. The other was a control group studied by a traditional method. The study adopted the quasi-experimental design. To achieve the objectives of the study, a test was conducted to measure the conceptual understanding, and the measure of the concern of mathematics, were verified for their validity and reliability. The results showed significant differences between the two groups on the conceptual understanding test. These differences were in favor of the experimental group. The results showed that there were differences on the math anxiety scale in the experimental group compared to the control group. ملخص: هدفت الدراسة إلى تقصّي فاعلية برنامج قائم على الاتصال الرياضي في تنمية الفهم المفاهيمي وخفض مستوى قلق الرياضيات لدى طلبة الصف الثامن الأساسي. وتكونت عينة الدراسة من (54) طالبة من طالبات الصف الثامن الأساسي المسجلات في مدرستين في بلدة علعال التابعتين لمديرية التربية والتعليم للواء قصبة إربد خلال الفصل الثاني للعام الدراسي 2017-2018م, وزعن بالتساوي إلى مجموعتين (تجريبية وضابطة), إذ تعرضت التجريبية لبرنامج قائم على الاتصال الرياضي, أما الضابطة فقد درست بالطريقة الاعتيادية, وقد اعتمدت الدراسة المنهج شبه التجريبي. ولتحقيق أهداف الدراسة, تمّ إعداد اختبار لقياس الفهم المفاهيمي, ومقياس قلق الرياضيات, تمّ التأكد من صدقهما وثباتهما. وقد أظهرت النتائج وجود فروق جوهرية بين المجموعتين على اختبار الفهم المفاهيمي, وجاءت هذه الفروق لصالح المجموعة التجريبية. وكما أظهرت النتائج وجود فروق على مقياس قلق الرياضيات؛ لدى المجموعة التجريبية مقارنة بالمجموعة الضابطة

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

Catalytic cleavage of HEAT and subsequent covalent binding of the tetralone moiety by the SARS-CoV-2 main protease

Here we present the crystal structure of SARS-CoV-2 main protease (Mpro) covalently bound to 2-methyl-1-tetralone. This complex was obtained by co-crystallization of Mpro with HEAT (2-(((4-hydroxyphenethyl)amino)methyl)-3,4-dihydronaphthalen-1(2H)-one) in the framework of a large X-ray crystallographic screening project of Mpro against a drug repurposing library, consisting of 5632 approved drugs or compounds in clinical phase trials. Further investigations showed that HEAT is cleaved by Mpro in an E1cB-like reaction mechanism into 2-methylene-1-tetralone and tyramine. The catalytic Cys145 subsequently binds covalently in a Michael addition to the methylene carbon atom of 2-methylene-1-tetralone. According to this postulated model HEAT is acting in a pro-drug-like fashion. It is metabolized by Mpro, followed by covalent binding of one metabolite to the active site. The structure of the covalent adduct elucidated in this study opens up a new path for developing non-peptidic inhibitors

Calpeptin is a potent cathepsin inhibitor and drug candidate for SARS-CoV-2 infections

Several drug screening campaigns identified Calpeptin as a drug candidate against SARS-CoV-2. Initially reported to target the viral main protease (Mpro), its moderate activity in Mpro inhibition assays hints at a second target. Indeed, we show that Calpeptin is an extremely potent cysteine cathepsin inhibitor, a finding additionally supported by X-ray crystallography. Cell infection assays proved Calpeptin’s efficacy against SARS-CoV-2. Treatment of SARS-CoV-2-infected Golden Syrian hamsters with sulfonated Calpeptin at a dose of 1 mg/kg body weight reduces the viral load in the trachea. Despite a higher risk of side effects, an intrinsic advantage in targeting host proteins is their mutational stability in contrast to highly mutable viral targets. Here we show that the inhibition of cathepsins, a protein family of the host organism, by calpeptin is a promising approach for the treatment of SARS-CoV-2 and potentially other viral infections