Pattern of cesarean deliveries among women in an urban and rural district in Egypt

Aim: to compare patterns of delivery at an urban and a rural district in Egypt over 3 years. Methods: This retrospective study included 500 women and 50 obstetricians from each district from January, 2013 till December, 2015. Women answered a questionnaire about their deliveries. Obstetricians answered a questionnaire about their practiceof CS. Results: CS rate in the rural district was 57.2% compared to 54.8% in the urban district in 2013. In 2014 and 2015, CS rates increased to 65.3% and 69%, respectively in the rural district compared to 56% and 57.7%, respectively in the urban district. 66% of obstetricians in the rural district performed CS for more than 50% of their patients compared to 76% of obstetricians in the urban district. 52% and 4% of obstetricians in the rural and urban districts, respectively, performed CS upon maternal request. 70.3% of women in the rural district who delivered by CS preferred to deliver vaginally. 51.4% of urban women who delivered by CS preferred to deliver vaginally. Level of education was the only factor showing statistical significance. Conclusion: CS rates increased over time with higher rates in the rural area. Level of women's education was the only factor affecting delivery choice. Keywords: Cesarean sections; CS rate; urban area; rural area; Egypt; obstetricians

A parametric study of the development of transverse deck cracking

Bridges and especially bridge decks experience problems of transverse cracking and deterioration. The causes of early age cracking are mainly due to plastic shrinkage, temperature effects, autogenous shrinkage, and drying shrinkage. Many parameters can affect the development of such cracks. The cracks can be influenced by material characteristics, formwork, climate conditions, geometry, load patterns, amount of deflection, and time dependent factors. It is important to resolve the issue of transverse deck cracking otherwise several bridge decks may experience loss of stiffness and the possibility loss of function which may affect the safety of bridges. This paper examines the effect of a wide range of parameters on the development of cracking. The parameters include, the number of spans, the span length, girder spacing, deck thickness, concrete compressive strength, dead load, hydration, temperature, shrinkage, and creep. The importance of each parameter is identified and then evaluated. Also, the AASHTO Standard Specification limits live-load deflections to L/800 for ordinary bridges and L/1000 for bridges in urban areas that are subject to pedestrian use. One of the main objectives of the study is also to ensure that the current deflection limit is adequate. It is determined that the deflection limit is an important parameter to affect cracking. The current deflection limit needs to be revisited and modified. A set of recommendations to limit the transverse deck cracks in bridge decks is also presented. © Civil-Comp Press, 2012

Bond strength durability of BFRP bars in concrete subjected to elevated temperature and alkaline environment

The use of basalt fiber–reinforced polymer (BFRP) bars as a reinforcing material for concrete structures has gained increasing interest worldwide. Limited studies have been reported on the performance of BFRP bars in concrete when exposed to harsh environments. This paper presents the test results of an experimental study aimed at investigating the bond strength durability of BFRP bars embedded in concrete when exposed to accelerated environmental effects. The experimental program included testing and investigating BFRP deformed bars with 12-mm diameter. Pullout specimens were tested under direct tensile load after being exposed to an alkaline solution (pH=12.9) for up to 6 months at elevated temperatures of 40 o C. Effects of alkali environment and exposure periods on the bond strength, degradation mechanism, and mode of failure of reinforced specimens with BFRP were investigated. The test results revealed that the average bond strength of conditioned specimens after 1.5, 3, and 6 months of exposure at 40o C were 14.8, 13.3, and 12.5 MPa, while the bond strength of unconditioned specimens was 15.5 MPa. Accelerated alkaline environments had a harmful effect on bond strength of conditioned specimens over time. After 6 months of exposure, the bond strength retention was 81% compared to that of the unconditioned specimens

Efficient Energy Recovery Scenarios from Pressure-Reducing Stations Intended for New Al-Alamein City in Egypt

Worldwide concerns over energy optimization and harnessing have sparked a variety of research on utilizing wasted energy. Natural gas, in particular, has been an essential energy commodity for domestic and industrial applications. This paper approaches the same principle throughout the Egyptian natural gas conventional national grid. The real case of Egypt’s Al-Alamein city gas line extension is analytically studied for energy harness. Thus, this paper aims to study the replacement of conventional energy-wasting pressure-reducing stations with power-producing expander generator systems to utilize pressure reduction in electricity generation. The mathematical equations that describe the energy recovery processes are presented. Reliable commercial software is used to verify the possible implementation of turbo expander stations in three scenarios. Each scenario is defined, and its main components and numerical parameters are introduced. Hence, the resulting energy outputs and applicability of all scenarios are compared to provide adequate energy recovery solutions

Analiza numeryczna różnic między charakterystykami działania stożkowych wężownic spiralnych i zwykłych wężownic spiralnych stosowanych jako osuszacze w zespołach osuszania i nawilżania w instalacjach odsalania wody

This numerical research is devoted to introducing the concept of helical cone coils and comparing the performance of helical cone coils as heat exchangers to the ordinary helical coils. Helical and spiral coils are known to have better heat and mass transfer than straight tubes, which is attributed to the generation of a vortex at the helical coil. This vortex, known as the Dean Vortex, is a secondary flow superimposed on the primary flow. The Dean number, which is a dimensionless number used in describing the Dean Vortex, is a function of Reynolds Number and the square root of the curvature ratio, so varying the curvature ratio for the same coil would vary the Dean Number. Numerical investigation based on the commercial CFD software fluent is used to study the effect of changing the structural parameters (taper angle of the helical coil, pitch and the base radius of curvature changes while the height is kept constant) on the Nusselt Number, heat transfer coefficient and coil outlet temperature. Six main coils having pipe diameters of 10 and 12.5 mm and base radius of curvature of 70, 80 and 90 mm were used in the investigation. It was found that, as the taper angle increases, both Nusselt Number and the heat transfer coefficient increase, also the pitch at the various taper angles was found to have an influence on Nusselt Number and the heat transfer coefficient. A MATLAB code was built to calculate the Nusselt Number at each coil turn, then to calculate the average Nusselt number for all of the coil turns. The MATLAB code was based on empirical correlation of Manlapaz and Churchill for ordinary helical coils. The CFD simulation results were found acceptable when compared with the MATLAB results.W pracy przedstawiono badania numeryczne mające na celu prezentację koncepcji stożkowych wężownic spiralnych i porównanie charakterystyk ich działania jako wymienników ciepła do charakterystyk zwykłych wężownic spiralnych. Jak wiadomo, wężownice spiralne i stożkowe charakteryzują się lepszym przenoszeniem ciepła i masy niż proste rury, co jest związane z powstawaniem wiru w wężownicy spiralnej. Ten tzw. wir Deana (Dean Vortex) jest przepływem wtórnym, nałożonym na przepływ pierwotny. Bezwymiarowy współczynnik Deana, stosowany do opisu wiru Deana, jest funkcją liczby Reynoldsa i pierwiastka kwadratowego ze współczynnika krzywizny, toteż liczba Deana zmienia się dla danej wężownicy wraz z jej krzywizną. Obliczenia numeryczne wykonano przy użyciu komercyjnego oprogramowania CFD w celu zbadania wpływu zmian parametrów strukturalnych wężownicy spiralnej (kąt zbieżności, skok i promień bazowy krzywizny zmieniały się, podczas gdy wysokość pozostawała stała) na liczbę Nusselta, współczynnik wymiany ciepła i temperaturę na wyjściu wężownicy. W badaniach wykorzystano sześć głównych wężownic, o średnicach rury 10 i 12,5 mm i promieniach bazowych krzywizny 70, 80 i 90 mm. W wyniku badań stwierdzono, że zarówno liczba Nusselta jak współczynnik wymiany ciepła rosną wraz ze wzrostem kąta zbieżności. Stwierdzono również, że przy różnych kątach zbieżności skok spirali ma wpływ na liczbę Nusselta i współczynnik wymiany ciepła. Opracowano program w środowisku MATLAB przy pomocy którego obliczono liczby Nusselta dla każdego zwoju wężownicy; na tej podstawie obliczono następnie wartość średnią liczby Nusselta dla całej wężownicy. Program obliczeniowy był oparty na równaniu empirycznym Manlapaza i Churchilla dla zwykłych wężownic spiralnych. Wyniki symulacji uzyskane przy użyciu oprogramowania CFD okazały się możliwe do przyjęcia w zestawieniu z wynikami obliczeń w programie MATLAB

Genetic resistance of eight native Egyptian chicken breeds having chicken B-cell marker 6 gene post-challenge with field strain of Marek's disease-induced tumor virus

Aim: The aim of this work was to detect chicken B-cell marker 6 (ChB6) gene in some native breeds in Egypt and find the relationship between founded genes in these different breeds to determine the resistance of native Egyptian breeds of chicken to Marek's disease (MD). Materials and Methods: A total of 14 different chicken breeds (30 each) including ten native breeds in addition to SPF Lohmann, High Line, Bovans, and Roodiland were used. Blood samples were collected for the detection of (ChB6,) by polymerase chain reaction (PCR) assay and sequenced to determine the presence or absence of ChB6 gene. Experimental infection was done using local field isolated MD virus (MDV) of 11 (1 day old) unvaccinated chick breeds having no maternal antibodies against MDV. Ten breeds of them carry ChB6 gene, eight breeds were native, and the rest two breeds were SPF Lohmann and High Line in addition to a group of ChB6 gene-lacking breed (Bovans) were infected. Spleen samples were collected from all infected breeds at 20th, 25th, 30th, 35th, and 40th weeks post-infection and tested by PCR assay for the detection of MDV. Furthermore, at 40th week post-infection, tumorized spleen sample of Bovans breed was collected and prepared for examination by transmission electron microscope (TEM) to confirm the presence of MDV. Results: Our results revealed the positivity of 10 out of 14 breeds (Gimmizah , Sinai, Dandarawi, Fayoumi, Golden Montazah, Matrouh, Beheri, Dokki, SPF Lohmann, and High Line) to the presence of ChB6 gene and resistance to MDV infection, while the Bovans, Mandarah , Inshas and Roodiland breeds lack the ChB6 gene and are susceptible to MDV infection. The collected spleen samples revealed negative for the presence of challenged MDV by PCR in 10 breeds (Gimmizah, Sinai, Dandarawi, Fayoumi, Golden Montazah, Matrouh, Beheri, Dokki, SPF Lohmann, and High Line) and positive for Bovans breed. TEM is used to confirm MDV infection in Bovans group which demonstrated tumors. Conclusion: The study confirms the relationship between the presence of ChB6 gene in our native breeds and the absence of tumors

Numerical simulation of double-diffusive natural convective flow in an inclined rectangular enclosure in the presence of magnetic field and heat source, part A: Effect of Rayleigh number and inclination angle

Double-diffusive convective flow in an inclined rectangular enclosure with the shortest sides being insulated and impermeable is investigated numerically. Constant temperatures and concentration are imposed along the longest sides of the enclosure. In addition, a uniform magnetic field is applied in a horizontal direction. Laminar regime is considered under steady state condition. The transport equations for continuity, momentum, energy and species transfer are solved using the finite volume technique. The validity of the numerical code used is ascertained and good agreement was found with published results. The numerical results are reported for the effect of thermal Rayleigh number on the contours of streamline, temperature, and concentration. In addition, results for the average Nusselt and Sherwood numbers are presented and discussed for various parametric conditions. This study was done for constant Prandtl number, Pr = 0.7, aspect ratio, A = 2, Lewis number, Le = 2, the buoyancy ratio, N = 1, Hartmann number, Ha = 10 and the dimensionless heat generation, Φ = 1. Computations are carried out for RaT ranging from 103 to 5 * 105 and inclination angle range of 0° ⩽ γ ⩽ 180°