Papers by Eng Mohamed Ibrahim
This paper presents simplified approaches for the convenient design of grounding grid configurati... more This paper presents simplified approaches for the convenient design of grounding grid configurations buried in uniform or non-uniform soil. The parallel grid conductors with different spaces are distributed using these approaches according to soil parameters which grid is buried in, hence, the equalization of current density and then decreasing of GPR are achieved. The image method is suggested to calculate the GPR and the earth surface potentials with accurate results for the grids buried in uniform or non-uniform soil structure. Charts of voltage profiles have been designed in 2D and 3D to make the selection of suitable earthing system easier. Index Terms – Touch voltage, earth surface potential, unequally spaces, conductor distribution.
Journal of Food Engineering, 2004
The effects of air temperature, air-flow rate and sample thickness on drying kinetics of carrot c... more The effects of air temperature, air-flow rate and sample thickness on drying kinetics of carrot cubes were investigated. Convective air drying characteristics of carrot cubes were evaluated in a cabinet dryer. Drying was carried out at 50, 60, 65, 70°C and drying data were analyzed to obtain diffusivity values from the period of falling drying rate. In the falling rate period, moisture transfer from carrot cubes was described by applying the FickÕs diffusion model, and effective moisture diffusion coefficients were calculated. Effective diffusivity increased with increasing temperature. An Arrhenius relation with an activation energy value of 28.36 kJ/mol expressed effect of temperature on the diffusivity. Two mathematical models available in the literature were fitted to the experimental data. The Page model is given better prediction than the Henderson and Pabis model and satisfactorily described drying characteristics of carrot cubes.
Journal of Food Engineering, 2002
This work presents a theoretical and experimental study of the drying kinetics of red peppers und... more This work presents a theoretical and experimental study of the drying kinetics of red peppers under different pretreatment and air drying conditions. Red peppers, Capsicum annuum, grown in the region of Kahramanmaras, Turkey, were pretreated with various solutions of alkaline emulsion of ethyl oleate (AEEO) and dried afterwards. To date, there has been no work that studied the effect of AEEO pretreatment solution on the drying of red peppers. Our results indicated that pretreated peppers dried faster and had higher Hunter L (lightness), þa (redness) and þb (yellowness) values than the untreated and dried peppers. 2% ethyl oleate and 5% K 2 CO 3 solution was found to be the most effective dipping solution that provided for whole peppers dried at 50°C, and yielded best color quality. Drying curves of sliced peppers were obtained using the Page and exponential equations. Comparing the r 2 values of both equations, it was concluded that the Page equation represents drying characteristics better than the exponential equation.
Journal of Food Engineering, 2005
Air-drying characteristics of okra were investigated in a laboratory scale hot-air dryer for a te... more Air-drying characteristics of okra were investigated in a laboratory scale hot-air dryer for a temperature range 50-70°C, and a relative humidity range 8-25%. Results indicated that drying took place in the falling rate period. Moisture transfer from okra was described by applying the FickÕs diffusion model, and the effective diffusivity was calculated. Effective diffusivity increased with increasing temperature. An Arrhenius relation with an activation energy value of 51.26 kJ/mol expressed the effect of temperature on the diffusivity. Two mathematical models, the Page and the simple exponential models, available in the literature were fitted to the experimental data. The performance of these models is evaluated by comparing the coefficient of determination (R 2) and reduced chi-square (v 2) between the observed and predicted moisture ratio. The Page model gave the best results for describing single layer drying of okra.
Energy Conversion and Management, 2009
An experimental investigation has been conducted to clarify heat transfer characteristics and ent... more An experimental investigation has been conducted to clarify heat transfer characteristics and entropy generation for individual elliptic tubes with longitudinal fins. The investigated geometrical parameters included the placement of the fins at the front of the tube, at the rear of the tube and at the front and rear of the tube. The experiments have been carried out on the different cases of electrically heated elliptic tubes which are separately installed in a square tunnel. The surface temperature at different cases of elliptic tubes, have been measured. The testing fluid was air and the Reynolds number ranged from about 4.75 Â 10 3 to 3.96 Â 10 4. The analysis of the entropy generation is based on the principle of minimizing the rate of total entropy generation that includes the generation of entropy due to heat transfer and friction forces are presented. The results indicate that the fin position on the elliptic tube has an effect on the results of heat transfer coefficient, friction factor and irreversibility ratio. The correlations of average Nusselt number, friction factor and irreversibility ratio with Re are presented.
Energy Conversion and Management, 2008
Heat and fluid flow characteristics for sinusoidal smooth pipes with different wavelength and amp... more Heat and fluid flow characteristics for sinusoidal smooth pipes with different wavelength and amplitude have been investigated experimentally. The effects of the dimensionless wavelength (a/d i) and the amplitude (b/d i) on the thermal performance of a sinusoidal pipe inside a straight pipe heat exchanger are investigated. The experiments employed one straight smooth pipe, five sinusoidal smooth pipes at different a/d i and three sinusoidal smooth pipes at different b/d i. The Reynolds number ranged from 8.8 • 10 3 to 2.8 • 10 4 , and the Prandtl number ranged from 4.53 to 5.85. The range of the dimensionless wavelength (b/d i) is from 18.52 to 55.55, and the dimensionless amplitude (a/d i) range is from 4 to 13.6. The results showed that the heat transfers in sinusoidal pipes are increased in all cases of a/d i and b/d i above those of the straight pipe. Also, the friction factor (f) in the sinusoidal pipes is increased in all cases of a/d i and b/d i above that of the straight pipe. The dimensionless exergy loss (e) decreases with the increase of b/d i , but in the case of a/d i , the maximum of e is attained at a/d i = 6.22 and the minimum is attained at a/d i = 13.6. Correlations of Nu and f as a function of Re, b/d i and a/d i are presented. Also, a correlation of e as a function of Re, b/d i and a/d i is given.
Magnetics, IEEE …, 1981
Svuaktmaefthh utlclo,tlupublhhw xmotmtln U,so wwwmwfM mtdfn snon8xc!whR, ro@tv+fHHw to *WI of mpf... more Svuaktmaefthh utlclo,tlupublhhw xmotmtln U,so wwwmwfM mtdfn snon8xc!whR, ro@tv+fHHw to *WI of mpfodua ttu Pubwud foml of t-tdbu. lton, of w Otlowotlufs todoM,*u.8.00wwnMtpur.-. LOS ALAMOS SCIENTIFIC LABORATORY wet Offlcs 60X W3 tm08 AIwI'108, ?dOW MOXkO 87MS All Mhllath Aotk)n/&@~En@Qf8r Lossfor lossAs Part Coil Alone, of Stack. x of 20 m zof20f4J 0.11 .1s
Journal of Food Engineering, 2002
This work presents a theoretical and experimental study of the drying kinetics of red peppers und... more This work presents a theoretical and experimental study of the drying kinetics of red peppers under different pretreatment and air drying conditions. Red peppers, Capsicum annuum, grown in the region of Kahramanmaras, Turkey, were pretreated with various solutions of alkaline emulsion of ethyl oleate (AEEO) and dried afterwards. To date, there has been no work that studied the effect of AEEO pretreatment solution on the drying of red peppers. Our results indicated that pretreated peppers dried faster and had higher Hunter L (lightness), þa (redness) and þb (yellowness) values than the untreated and dried peppers. 2% ethyl oleate and 5% K 2 CO 3 solution was found to be the most effective dipping solution that provided for whole peppers dried at 50°C, and yielded best color quality. Drying curves of sliced peppers were obtained using the Page and exponential equations. Comparing the r 2 values of both equations, it was concluded that the Page equation represents drying characteristics better than the exponential equation.
… of the Arab World: proceedings of …, 1992
ecancermedicalscience.com
Background: Locally advanced breast cancer (LABC) is common in developing countries and it freque... more Background: Locally advanced breast cancer (LABC) is common in developing countries and it frequently affects younger women. Patients do very poorly when treated by locoregional therapy alone; therefore, pre-operative systemic therapy (PST) is commonly used. Materials and methods: Medical records of 64 Saudi patients with LABC treated with PST in a single institution were retrospectively reviewed. Results: At diagnosis, most patients were young (median age 41 years), and had poor clinicopathological characteristics. Following surgery, complete pathologic response (pCR) in the breast was achieved in 13 patients (20%). Of 62 patients with known nodal status, 22 (34%) had negative axillary nodes. Presence of oestrogen receptor (ER) negative tumour was the only dependent variable that predicted pCR in the breast (p = 0.03). At a median follow-up of 42 months, the median progression-free survival (PFS) was 48 months (95% CI, 20-76 months) and the projected five-year overall survival (OS) was 68%. The recently published scoring system (Jeruss et al (2008) J Clin Oncol 26 2 246-52), was the only variable that independently influenced PFS, while ER negative tumours and presence of lymphovascular space invasion were the only factors that adversely affected OS. Conclusions: despite the use of standard multi-modality approach in the management of patients with LABC, prognosis remains guarded.
Journal of food engineering, 2005
Air-drying characteristics of okra were investigated in a laboratory scale hot-air dryer for a te... more Air-drying characteristics of okra were investigated in a laboratory scale hot-air dryer for a temperature range 5070° C, and a relative humidity range 825%. Results indicated that drying took place in the falling rate period. Moisture transfer from okra was described by ...
Journal of Physics-condensed Matter, 1998
Silver antimony diselenide 0953-8984/10/4/013/img7 thin films were prepared by a thermal vacuum e... more Silver antimony diselenide 0953-8984/10/4/013/img7 thin films were prepared by a thermal vacuum evaporation technique onto quartz and glass substrates kept at room temperature 0953-8984/10/4/013/img8. The as-deposited films were amorphous and transformed to a face centred cubic (FCC) polycrystalline nature with the lattice constant 0953-8984/10/4/013/img9 on post-deposition annealing above 423 K for one hour in argon atmosphere. The optical constants (the
Application of laser irradiation with porphyrin(s) or their derivatives for the destruction of tu... more Application of laser irradiation with porphyrin(s) or their derivatives for the destruction of tumors in humans requires preliminary studies of their localization in normal and malignant tissues. A novel derivative of hematoporphyrin (HP) was prepared. The newly developed hematoporphyrin (DHP) was administered to Fisher rats with bladder tumors and showed greater accumulation in the tumoral tissues. Comparative data oh (HP) and (DHP) are presented and discussed in light of the enhanced tumor porphyrin uptake caused by these agents. The homogeneous intense fluorescence noted with DHP-treated animals suggests that total tumor kill curative therapy will be more feasible. The study paves the way to refining increased porphyrin augment phototherapy and laser application in the field of oncology. bladder cancer / hematoporphyrin derivative / phototherapy / porphyrins
Journal of …, 1987
... Abstract. A moderate earthquake occurred in the unpopulated area of Kalabsha in the southeast... more ... Abstract. A moderate earthquake occurred in the unpopulated area of Kalabsha in the southeastern part of the Western Desert of Egypt on November 14, 1981. ... 5). The Kalabsha fault strikes east-west through the center of Wadi Kalabsha, passing south of the limestone plateau. ...
Journal of Parenteral …, 2002
This study sought to compare 2 strategies for the administration of enteral feeding to mechanical... more This study sought to compare 2 strategies for the administration of enteral feeding to mechanically ventilated medical patients. The prospective, controlled, clinical trial was carried out in a medical intensive care unit (19 beds) in a university-affiliated, urban teaching hospital. Between May 1999 and December 2000, 150 patients were enrolled. Patients were scheduled to receive their estimated total daily enteral nutritional requirements on either day 1 (early-feeding group) or day 5 (late-feeding group) of mechanical ventilation. Patients in the late-feeding group were also scheduled to receive 20% of their estimated daily enteral nutritional requirements during the first 4 days of mechanical ventilation. Seventy-five (50%) consecutive eligible patients were entered into the early-feeding group and 75 (50%) patients were enrolled in the late-feeding group. During the 5 five days of mechanical ventilation, the total intake of calories (2370 +/- 2000 kcal versus 629 +/- 575 kcal; p < .001) and protein (93.6 +/- 77.2 g versus 26.7 +/- 26.6 g; p < .001) were statistically greater for patients in the early-feeding group. Patients in the early-feeding group had statistically greater incidences of ventilator-associated pneumonia (49.3% versus 30.7%; p = .020) and diarrhea associated with Clostridium difficile infection (13.3% versus 4.0%; p = .042). The early-feeding group also had statistically longer intensive care unit (13.6 +/- 14.2 days versus 9.8 +/- 7.4 days; p = .043) and hospital lengths of stay (22.9 +/- 19.7 days versus 16.7 +/- 12.5 days; p = .023) compared with patients in the late-feeding group. No statistical difference in hospital mortality was observed between patients in the early-feeding and late-feeding groups (20.0% versus 26.7%; p = .334). The administration of more aggressive early enteral nutrition to mechanically ventilated medical patients is associated with greater infectious complications and prolonged lengths of stay in the hospital. Clinicians must balance the potential for complications resulting from early enteral feeding with the expected benefits of such therapy.
Genomics, 1992
The plasma membrane Ca 2+ -pumping ATPase (Ca 2+ -ATPase) is responsible for maintaining calcium ... more The plasma membrane Ca 2+ -pumping ATPase (Ca 2+ -ATPase) is responsible for maintaining calcium homeostasis in eukaryotic cells. The Ca 2+ -ATPase is a family of pumps that are encoded by at least four genes. A cDNA for the human version of Ca 2+ -ATPase isoform PMCA2 ...
Fertility and Sterility, 2011
Objective: To determine if outcomes after in vitro fertilization with intracytoplasmic sperm inje... more Objective: To determine if outcomes after in vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI) using sperm from men with spinal cord injury (SCI group) differ from those of other etiologies of male factor infertility (non-SCI group). In men with SCI, to determine if IVF/ICSI outcomes differ with sperm obtained by penile vibratory stimulation (PVS group) versus electroejaculation (EEJ group). Design: Retrospective analysis. Setting: University medical center and major infertility center. Patient(s): Couples with male factor infertility due to SCI versus other etiologies. Intervention(s): PVS, EEJ, surgical sperm retrieval, and IVF/ICSI. Main Outcome Measure(s): Rates of fertilization, pregnancy, and live birth. Result(s): A total of 31 couples in the SCI group underwent 48 cycles of IVF/ICSI, and a total of 297 couples in the non-SCI group underwent 443 cycles of IVF/ICSI. The SCI group had lower fertilization rates but similar pregnancy and live birth rates compared with the non-SCI group. These rates, however, did not differ significantly when the PVS group was compared with the EEJ group. Conclusion(s): IVF/ICSI of sperm from men with SCI yield lower fertilization rates but similar pregnancy and live birth outcomes as IVF/ICSI of sperm from men with other etiologies of male factor infertility. Sperm collected by PVS versus EEJ in men with SCI appear to result in similar IVF/ICSI success rates.
Journal of …, 2008
Semen from men with spinal cord injuries (SCI) and control subjects was investigated for sperm DN... more Semen from men with spinal cord injuries (SCI) and control subjects was investigated for sperm DNA damage using the sperm chromatin structure assay. Three experiments were performed. In experiment 1, the DNA fragmentation index (DFI) was compared in semen from SCI subjects and control subjects. In experiment 2, the % DFI was determined in repeated ejaculations to examine the effect of anejaculation on DFI. In experiment 3, the DFI was determined in neat vs processed semen to examine the effect of necrospermia or leukocytospermia on DFI. The results of experiment 1 showed a significantly higher mean (6 SEM) DFI in the semen of SCI subjects (65.2% 6 6.6%; range, 42.3%-90.8%) compared with control subjects (15.4% 6 2.9%; range, 5.4%-33.5%; P , .001). In experiment 2, there was a high correlation between the DFIs obtained in the first semen specimens and the DFIs obtained 3 days later in semen of the same SCI subjects (r s 5 .94; P , .02). In experiment 3, the results showed no significant difference between mean DFI in aliquots of neat semen (79.3% 6 9.9%) vs matched aliquots of semen processed to remove dead sperm and leukocytes in SCI subjects (75.2% 6 16.1%). The DFI is higher in semen from men with SCI vs controls. The cause of this condition is unknown but does not seem to be due to prolonged anejaculation or to the proximate conditions of necrospermia or leukocytospermia. The relevance of these findings to fertility outcomes with SCI male partners remains to be determined.
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Papers by Eng Mohamed Ibrahim