Ali Nasser - Academia.edu (original) (raw)
Papers by Ali Nasser
Journal of Al-Azhar University Engineering Sector
Metal rolling processes are usually subjected to continuous development for increasing the effici... more Metal rolling processes are usually subjected to continuous development for increasing the efficiency of metals industry and broadening the applicability of soft metals in the structural applications. During this study, cold plate rolling have been conducted under different conditions. Particularly, the rolling power and the resulted separating force have been analyzed after changing the roll diameter, the draft thickness, and the lubricant type. It was observed that, decreasing the reduction by pass and reducing the roll diameter could minimize the need for high power during operation. It was also noticed that, among the different experiments, using olive and paraffin oil as lubricant at the roll-metal surface show a significant effect on reducing the power consumption and increasing the rolling process efficiency in a high agreement with the mathematical modeling.
Journal of Materials Engineering and Performance, 2016
Abstract WC-W2C/ZrO2 nanocomposites were synthesized by pressure-less sintering (PS) and spark pl... more Abstract WC-W2C/ZrO2 nanocomposites were synthesized by pressure-less sintering (PS) and spark plasma sintering (SPS) of tungsten carbide/yttria-stabilized tetragonal zirconia, WC/TZ-3Y. Prior to sintering, WC/TZ-3Y powders were totally ball-milled for 20 and 120 h to obtain targeted nano (N) and nano-nano (N-N) structures, indicated by transmission electron microscopy and powder x-ray diffraction (PXRD). The milled powders were processed via PS at temperatures of 1773 and 1973 K for 70 min and SPS at 1773 K for 10 min. PXRD as well as SEM-EDS indicated the formation of WC-W2C/ZrO2 composites after sintering. The mechanical properties were characterized via Vicker microhardness and nanoindentation techniques indicating enhancements for sufficiently consolidated composites with high W2C content. The effects of reducing particle sizes on phase transformation, microstructure and mechanical properties are reported. In general, the composites based on the N structure showed higher microhardness than those for N-N structure, except for the samples PS-sintered at 1773 K. For instance, after SPS at 1773 K, the N structure showed a microhardness of 18.24 GPa. Nanoindentation measurements revealed that nanoscale hardness up to 22.33 and 25.34 GPa and modulus of elasticity up to 340 and 560 GPa can be obtained for WC-W2C/ZrO2 nanocomposites synthesized by the low-cost PS at 1973 K and by SPS at 1773 K, respectively.
Almost one-third of all burn centre admissions involve children under the age of ten years. Carin... more Almost one-third of all burn centre admissions involve children under the age of ten years. Caring for the burned child continues to demand the close attention of a multidisciplinary team to the patient's many needs. Paediatric burns impose enormous economic burdens on families and on society as a whole. Scald burns secondary to household accidents predominate in most series, constituting 70% of all thermal injuries in infants, toddlers, and preschool children. Most of these injuries are potentially preventable. Children with 5% TBSA third-degree burns or more than 10% TBSA second-and third-degree burns need to be hospitalized for proper resuscitation and burn wound management. Children with burn injuries involving the face, hands, or genital areas also require hospitalization. The goal of the resuscitation of hospitalized burn victims is to restore circulating blood volume and to minimize the early stress response. This is accomplished with adequate fluid replacement, correction of hypoxia and ventilatory disturbances, prevention of hypothermia, and adequate control of pain and anxiety. Minor burns can be treated at home with topical ointments. The recently introduced MEBO (Moist Exposed Burn Ointment) seems to be highly promising in this regard. Burn wounds should be encouraged to heal in the shortest possible period by a judicious combination of topical therapy, eschar excision, and skin grafting.
Case Reports in Surgery, 2015
ERCP is attended with certain complications, the majority of which are well known to the medical ... more ERCP is attended with certain complications, the majority of which are well known to the medical community. Other less-known complications also exist. Guidewire injury to the hepatic or pancreatic parenchyma represents one of the much less appreciated, albeit preventable, complications. In this report, we present the clinical course of three patients who sustained guidewire perforation of the pancreatic or hepatic parenchyma. In one patient, the clinical deterioration was confidently attributed to guidewire perforation of the pancreatic parenchyma. Conservative treatment was successful and unnecessary emergency surgery was thus avoided. In the other two, in whom the cause of the clinical deterioration was unclear, an emergency surgery was performed. Guidewire injury to the hepatic parenchyma was then confirmed which needed only intraperitoneal drainage, with successful outcome.
Physics of Plasmas, 2000
The effects of the presence of a uniform magnetic field on the growth rate and the threshold inte... more The effects of the presence of a uniform magnetic field on the growth rate and the threshold intensity of the two-plasmon decay in a homogeneous plasma have been investigated. Analytical expressions for the growth rate and threshold intensity have been obtained. It has been shown that the presence of a magnetic field affects significantly the growth rate and the threshold intensity for the two-plasmon decay.
… , 1989, IEEE 39th, 1989
The authors present look angle contours over Arab Gulf countries to enable engineers and technici... more The authors present look angle contours over Arab Gulf countries to enable engineers and technicians to point any earth station directly (without any calculations) towards a given satellite in the geostationary orbit. Contours over Arab Gulf countries have ...
Analytical Biochemistry, 1995
A novel homogeneous immunoassay requiring only one incubation step, and applicable in principle t... more A novel homogeneous immunoassay requiring only one incubation step, and applicable in principle to the determination of low- as well as high-molecular-weight substances, has been developed. The method is based on (a) photooxidation by singlet oxygen (1O2) of a fluorescent substrate (1,3-diphenylisobenzofuran, DPBF) embedded in unilamellar vesicles on the surface of which antibody to the analyte antigen is covalently attached (DPBF-immunoliposomes); (b) generation of singlet oxygen, upon illumination, by a chromophore (erythrosine) covalently attached to an antibody (Ab*) or antigen (Ag*); (c) formation of a "sandwich"- or "competition"-type complex whereupon the singlet oxygen-generating chromophore conjugate (Ab* or Ag*) and immunoliposome-embedded DPBF are brought into close proximity. Competition- and sandwich-type model assay systems for the detection of protein antigens and viruses were investigated. The detection range with protein antigens in competition- and sandwich-type assays was three (10(-10) - 10(-7) M) and two (10(-10) - 10(-8) M) orders of magnitude, respectively. With poliovirus using a sandwich-type assay, the detection range was 10(2) - 10(6) plaque-forming units per milliliter (pfu/ml).
Toxicology …, 1996
the pulsatile pattern of ACTH. The mean values of ACTH during the bleeding period and the absolut... more the pulsatile pattern of ACTH. The mean values of ACTH during the bleeding period and the absolute pulse amplitude of ACTH peaks were significantly decreased, whereas a significant increase of pulse frequency of this hormone, by acute cadmium administration, was observed. On the other hand, cadmium administration did not change neither pulse duration nor relative amplitude of the ACTH peaks. These data suggest that acute cadmium chloride administration in adult male rats is followed by changes in the pulsatile ACTH pattern, which might be part of the mechanism to explain cadmium effects on the pituitary-adrenal axis.
Toxicology …, 1998
Carbon monoxide concentration was determined in the different departments of the Iron and Steel f... more Carbon monoxide concentration was determined in the different departments of the Iron and Steel factory.Carboxy-haemoglobin was also determined for twenty-five exposed workers and fifteen subjects nonoccupationally exposed to carbon monoxide. The highest ...
Catheterization and …, 1999
Degenerative disease of aortocoronary saphenous vein grafts is a major cause of late morbidity an... more Degenerative disease of aortocoronary saphenous vein grafts is a major cause of late morbidity and mortality in patients after coronary bypass surgery. We previously described a technique for recanalization of totally occluded grafts using extraction atherectomy (TEC) as a ...
The Annals of Thoracic Surgery, 2002
Journal of Al-Azhar University Engineering Sector
Metal rolling processes are usually subjected to continuous development for increasing the effici... more Metal rolling processes are usually subjected to continuous development for increasing the efficiency of metals industry and broadening the applicability of soft metals in the structural applications. During this study, cold plate rolling have been conducted under different conditions. Particularly, the rolling power and the resulted separating force have been analyzed after changing the roll diameter, the draft thickness, and the lubricant type. It was observed that, decreasing the reduction by pass and reducing the roll diameter could minimize the need for high power during operation. It was also noticed that, among the different experiments, using olive and paraffin oil as lubricant at the roll-metal surface show a significant effect on reducing the power consumption and increasing the rolling process efficiency in a high agreement with the mathematical modeling.
Journal of Materials Engineering and Performance, 2016
Abstract WC-W2C/ZrO2 nanocomposites were synthesized by pressure-less sintering (PS) and spark pl... more Abstract WC-W2C/ZrO2 nanocomposites were synthesized by pressure-less sintering (PS) and spark plasma sintering (SPS) of tungsten carbide/yttria-stabilized tetragonal zirconia, WC/TZ-3Y. Prior to sintering, WC/TZ-3Y powders were totally ball-milled for 20 and 120 h to obtain targeted nano (N) and nano-nano (N-N) structures, indicated by transmission electron microscopy and powder x-ray diffraction (PXRD). The milled powders were processed via PS at temperatures of 1773 and 1973 K for 70 min and SPS at 1773 K for 10 min. PXRD as well as SEM-EDS indicated the formation of WC-W2C/ZrO2 composites after sintering. The mechanical properties were characterized via Vicker microhardness and nanoindentation techniques indicating enhancements for sufficiently consolidated composites with high W2C content. The effects of reducing particle sizes on phase transformation, microstructure and mechanical properties are reported. In general, the composites based on the N structure showed higher microhardness than those for N-N structure, except for the samples PS-sintered at 1773 K. For instance, after SPS at 1773 K, the N structure showed a microhardness of 18.24 GPa. Nanoindentation measurements revealed that nanoscale hardness up to 22.33 and 25.34 GPa and modulus of elasticity up to 340 and 560 GPa can be obtained for WC-W2C/ZrO2 nanocomposites synthesized by the low-cost PS at 1973 K and by SPS at 1773 K, respectively.
Almost one-third of all burn centre admissions involve children under the age of ten years. Carin... more Almost one-third of all burn centre admissions involve children under the age of ten years. Caring for the burned child continues to demand the close attention of a multidisciplinary team to the patient's many needs. Paediatric burns impose enormous economic burdens on families and on society as a whole. Scald burns secondary to household accidents predominate in most series, constituting 70% of all thermal injuries in infants, toddlers, and preschool children. Most of these injuries are potentially preventable. Children with 5% TBSA third-degree burns or more than 10% TBSA second-and third-degree burns need to be hospitalized for proper resuscitation and burn wound management. Children with burn injuries involving the face, hands, or genital areas also require hospitalization. The goal of the resuscitation of hospitalized burn victims is to restore circulating blood volume and to minimize the early stress response. This is accomplished with adequate fluid replacement, correction of hypoxia and ventilatory disturbances, prevention of hypothermia, and adequate control of pain and anxiety. Minor burns can be treated at home with topical ointments. The recently introduced MEBO (Moist Exposed Burn Ointment) seems to be highly promising in this regard. Burn wounds should be encouraged to heal in the shortest possible period by a judicious combination of topical therapy, eschar excision, and skin grafting.
Case Reports in Surgery, 2015
ERCP is attended with certain complications, the majority of which are well known to the medical ... more ERCP is attended with certain complications, the majority of which are well known to the medical community. Other less-known complications also exist. Guidewire injury to the hepatic or pancreatic parenchyma represents one of the much less appreciated, albeit preventable, complications. In this report, we present the clinical course of three patients who sustained guidewire perforation of the pancreatic or hepatic parenchyma. In one patient, the clinical deterioration was confidently attributed to guidewire perforation of the pancreatic parenchyma. Conservative treatment was successful and unnecessary emergency surgery was thus avoided. In the other two, in whom the cause of the clinical deterioration was unclear, an emergency surgery was performed. Guidewire injury to the hepatic parenchyma was then confirmed which needed only intraperitoneal drainage, with successful outcome.
Physics of Plasmas, 2000
The effects of the presence of a uniform magnetic field on the growth rate and the threshold inte... more The effects of the presence of a uniform magnetic field on the growth rate and the threshold intensity of the two-plasmon decay in a homogeneous plasma have been investigated. Analytical expressions for the growth rate and threshold intensity have been obtained. It has been shown that the presence of a magnetic field affects significantly the growth rate and the threshold intensity for the two-plasmon decay.
… , 1989, IEEE 39th, 1989
The authors present look angle contours over Arab Gulf countries to enable engineers and technici... more The authors present look angle contours over Arab Gulf countries to enable engineers and technicians to point any earth station directly (without any calculations) towards a given satellite in the geostationary orbit. Contours over Arab Gulf countries have ...
Analytical Biochemistry, 1995
A novel homogeneous immunoassay requiring only one incubation step, and applicable in principle t... more A novel homogeneous immunoassay requiring only one incubation step, and applicable in principle to the determination of low- as well as high-molecular-weight substances, has been developed. The method is based on (a) photooxidation by singlet oxygen (1O2) of a fluorescent substrate (1,3-diphenylisobenzofuran, DPBF) embedded in unilamellar vesicles on the surface of which antibody to the analyte antigen is covalently attached (DPBF-immunoliposomes); (b) generation of singlet oxygen, upon illumination, by a chromophore (erythrosine) covalently attached to an antibody (Ab*) or antigen (Ag*); (c) formation of a "sandwich"- or "competition"-type complex whereupon the singlet oxygen-generating chromophore conjugate (Ab* or Ag*) and immunoliposome-embedded DPBF are brought into close proximity. Competition- and sandwich-type model assay systems for the detection of protein antigens and viruses were investigated. The detection range with protein antigens in competition- and sandwich-type assays was three (10(-10) - 10(-7) M) and two (10(-10) - 10(-8) M) orders of magnitude, respectively. With poliovirus using a sandwich-type assay, the detection range was 10(2) - 10(6) plaque-forming units per milliliter (pfu/ml).
Toxicology …, 1996
the pulsatile pattern of ACTH. The mean values of ACTH during the bleeding period and the absolut... more the pulsatile pattern of ACTH. The mean values of ACTH during the bleeding period and the absolute pulse amplitude of ACTH peaks were significantly decreased, whereas a significant increase of pulse frequency of this hormone, by acute cadmium administration, was observed. On the other hand, cadmium administration did not change neither pulse duration nor relative amplitude of the ACTH peaks. These data suggest that acute cadmium chloride administration in adult male rats is followed by changes in the pulsatile ACTH pattern, which might be part of the mechanism to explain cadmium effects on the pituitary-adrenal axis.
Toxicology …, 1998
Carbon monoxide concentration was determined in the different departments of the Iron and Steel f... more Carbon monoxide concentration was determined in the different departments of the Iron and Steel factory.Carboxy-haemoglobin was also determined for twenty-five exposed workers and fifteen subjects nonoccupationally exposed to carbon monoxide. The highest ...
Catheterization and …, 1999
Degenerative disease of aortocoronary saphenous vein grafts is a major cause of late morbidity an... more Degenerative disease of aortocoronary saphenous vein grafts is a major cause of late morbidity and mortality in patients after coronary bypass surgery. We previously described a technique for recanalization of totally occluded grafts using extraction atherectomy (TEC) as a ...
The Annals of Thoracic Surgery, 2002