Dina Hegazy - Academia.edu (original) (raw)
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University of Illinois at Chicago, College of Medicine
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The present study was carried out to evaluate the effects of high plant densities of three corn v... more The present study was carried out to evaluate the effects of high plant densities of three corn varieties on soybean productivity and land equivalent ratio (LER) under two intercropping systems. Three corn varieties S.C. 128, S.C. 130 and Syn. Cairo 1 with soybean variety Giza 111 were tested under intercropping and solid plantings. Intercropping systems adopted were alternating 2:2 ridge (70 cm/ridge) and mixed one (140cm/bed). Soybean plants were grown in two rows per ridge and beds and thinned to two plants at 15 and 20 cm between hills under intercropping and solid plantings, respectively. Corn plants were thinned to two plants per hill distanced at 20, 25 and 30 cm between hills under intercropping and solid plantings. A split plot distribution in randomized complete block design with three replications was used. Corn varieties were randomly assigned to main plots, whereas, cropping systems were distributed in the sub-plots and corn plant densities were assigned to sub sub-plot...
The present study was carried out at the experimental and research station, Faculty of Agricultur... more The present study was carried out at the experimental and research station, Faculty of Agriculture, Cairo University, Giza, Egypt, during 2013 and 2014 summer seasons to evaluate land use efficiency and economic feasibility by intercropping soybean with corn varieties under high population densities of corn plants. Three corn varieties S.C. 128, S.C. 130 and Syn. Cairo 1 with soybean variety Giza 111 were tested under intercropping and solid plantings. Intercropping systems adopted were alternating 2:2 ridge and mixed one. Soybean plants were thinned to two plants at 15 and 20 cm between hills under intercropping and solid plantings, respectively. Meanwhile, corn plants were thinned to two plants per hill distanced at 30, 25 and 20 cm between hills under intercropping and solid plantings. A split plot distribution in randomized complete block design with three replications was used. Corn varieties were randomly assigned to main plots, whereas, cropping systems were distributed in th...
Hydraulic Fracture Modeling, 2018
Abstract The production in organic-rich shale reservoirs typically decline very rapidly as a resu... more Abstract The production in organic-rich shale reservoirs typically decline very rapidly as a result of decay in fracture conductivity. Proppant embedment into fracture walls results in reduction in the width of the proppant pack impacting the fracture conductivity. Spalling can take place as small particles break off, lowering the proppant pack permeability and porosity. The results of these two damage mechanisms have been investigated experimentally in this chapter for Niobrara and Vaca Muerta shale core samples using simultaneous measurements of compressional and shear wave velocities, conductivity, geomechanical properties, and geochemical composition changes during core flow experiments under triaxial stress state initially measuring intact sample properties, then using Brazilian tests to fracture the samples, place proppants in the fractures, and measure the variation of fracture conductivity. Niobrara samples presented about 20%–25% Young's modulus decrease when 2% KCl was used, whereas Vaca Muerta samples' Young's modulus reduction with the same fluid was 5%, yet conductivity reduction was larger than Niobrara. This variation was attributed to local mineralogical changes in the samples and the choice of higher strength calcite-filled fracture location in Niobrara sample.
The present study was carried out to evaluate the effects of high plant densities of three corn v... more The present study was carried out to evaluate the effects of high plant densities of three corn varieties on soybean productivity and land equivalent ratio (LER) under two intercropping systems. Three corn varieties S.C. 128, S.C. 130 and Syn. Cairo 1 with soybean variety Giza 111 were tested under intercropping and solid plantings. Intercropping systems adopted were alternating 2:2 ridge (70 cm/ridge) and mixed one (140cm/bed). Soybean plants were grown in two rows per ridge and beds and thinned to two plants at 15 and 20 cm between hills under intercropping and solid plantings, respectively. Corn plants were thinned to two plants per hill distanced at 20, 25 and 30 cm between hills under intercropping and solid plantings. A split plot distribution in randomized complete block design with three replications was used. Corn varieties were randomly assigned to main plots, whereas, cropping systems were distributed in the sub-plots and corn plant densities were assigned to sub sub-plot...
The present study was carried out at the experimental and research station, Faculty of Agricultur... more The present study was carried out at the experimental and research station, Faculty of Agriculture, Cairo University, Giza, Egypt, during 2013 and 2014 summer seasons to evaluate land use efficiency and economic feasibility by intercropping soybean with corn varieties under high population densities of corn plants. Three corn varieties S.C. 128, S.C. 130 and Syn. Cairo 1 with soybean variety Giza 111 were tested under intercropping and solid plantings. Intercropping systems adopted were alternating 2:2 ridge and mixed one. Soybean plants were thinned to two plants at 15 and 20 cm between hills under intercropping and solid plantings, respectively. Meanwhile, corn plants were thinned to two plants per hill distanced at 30, 25 and 20 cm between hills under intercropping and solid plantings. A split plot distribution in randomized complete block design with three replications was used. Corn varieties were randomly assigned to main plots, whereas, cropping systems were distributed in th...
Hydraulic Fracture Modeling, 2018
Abstract The production in organic-rich shale reservoirs typically decline very rapidly as a resu... more Abstract The production in organic-rich shale reservoirs typically decline very rapidly as a result of decay in fracture conductivity. Proppant embedment into fracture walls results in reduction in the width of the proppant pack impacting the fracture conductivity. Spalling can take place as small particles break off, lowering the proppant pack permeability and porosity. The results of these two damage mechanisms have been investigated experimentally in this chapter for Niobrara and Vaca Muerta shale core samples using simultaneous measurements of compressional and shear wave velocities, conductivity, geomechanical properties, and geochemical composition changes during core flow experiments under triaxial stress state initially measuring intact sample properties, then using Brazilian tests to fracture the samples, place proppants in the fractures, and measure the variation of fracture conductivity. Niobrara samples presented about 20%–25% Young's modulus decrease when 2% KCl was used, whereas Vaca Muerta samples' Young's modulus reduction with the same fluid was 5%, yet conductivity reduction was larger than Niobrara. This variation was attributed to local mineralogical changes in the samples and the choice of higher strength calcite-filled fracture location in Niobrara sample.