Nuclear fuel performance modeling and simulation are critical tasks for nuclear fuel design optimization and safety analysis under normal and transient conditions.Fuel performance is a complicated phenomenon that invo...Nuclear fuel performance modeling and simulation are critical tasks for nuclear fuel design optimization and safety analysis under normal and transient conditions.Fuel performance is a complicated phenomenon that involves thermal,mechanical,and irradiation mechanisms and requires special multiphysics modules.In this study,a fuel performance model was developed using the COMSOL Multiphysics platform.The modeling was performed for a 2D axis-symmetric geometry of a UO2fuel pellet in the E110 clad for VVER-1200 fuel.The modeling considers all relevant phenomena,including heat generation and conduction,gap heat transfer,elastic strain,mechanical contact,thermal expansion,grain growth,densification,fission gas generation and release,fission product swelling,gap/plenum pressure,and cladding thermal and irradiation creep.The model was validated using a code-to-code evaluation of the fuel pellet centerline and surface temperatures in the case of constant power,in addition to validation of fission gas release(FGR)predictions.This prediction proved that the model could perform according to previously published VVER nuclear fuel performance parameters.A sensitivity study was also conducted to assess the effects of uncertainty on some of the model parameters.The model was then used to predict the VVER-1200 fuel performance parameters as a function of burnup,including the temperature profiles,gap width,fission gas release,and plenum pressure.A compilation of related material and thermomechanical models was conducted and included in the modeling to allow the user to investigate different material/performance models.Although the model was developed for normal operating conditions,it can be modified to include off-normal operating conditions.展开更多
Studies of atmospheric dispersion are essential to both the site selection of a nuclear power plant and the evaluation of the environmental impacts of nuclear operations. Atmospheric stability plays the most important...Studies of atmospheric dispersion are essential to both the site selection of a nuclear power plant and the evaluation of the environmental impacts of nuclear operations. Atmospheric stability plays the most important role in the dispersion of air pollutants. The focus of attention in the present study is the estimation of the degree of stability of the atmosphere for the north coast of Egypt to evaluate the ability of the atmosphere to disperse pollutants. A FORTRAN program （Appendix 1） is presented to determine atmospheric stability using the Pasquill-Tunner Method PTM, which defines the turbulent state of the atmosphere and also reflects upon the dispersion capabilities of the atmosphere at the site. This method used several meteorological factors such as wind speed, insulation, cloud cover height and type. Meteorological data from Matrouh stations in Egypt is applied for a simulated model. The total patterns of stability classification, both monthly and seasonal patterns, are determined, also the stability-wind rose and stability-wind summary are provided. Finally prediction of Iodine surface air concentration is reported as well as the annual effective dose for I- 131 as a case study.展开更多
Prays oleae Bern, （OM） andPalpita unionalis Hfib., （JM） are two of the most important pests in olive groves in Egypt. A 3-year monitoring study using sex pheromone traps in semi-arid and arid olive groves was perf...Prays oleae Bern, （OM） andPalpita unionalis Hfib., （JM） are two of the most important pests in olive groves in Egypt. A 3-year monitoring study using sex pheromone traps in semi-arid and arid olive groves was performed. In the semi-arid grove, flight pattern of the OM was the same as in other Mediterranean countries, but in dates concordating plant phenology. The moth completes three generations annually： the first flight is in March to April, the second is in May to June and the third occurs in August to October. In the arid olive grove, an interesting flight pattern was observed. First flight was always very close or overlapped with the second one with no male catches during August to October. However, eggs were present most of the season, indicating unusually high female presence and oviposition activity of the OM during the absence of males in the traps. Generally, moth densities were significantly lower in low fruiting years than in higher ones and were also lower in the arid olive grove than in the semi-arid one. In contrast, JM males were present all season, exhibiting six to seven and three to four overlapping flight peaks in arid and semi-arid olive groves, respectively. Moth densities were significantly higher in the arid olive grove than those in the semi-arid one. This study shows that trapping location and fruit beating year are characteristics that strongly affect the grove-specific information needed to estimate correctly adult emergence and thus the timing of control measures.展开更多
Development and implementation of pilgrims (Hajj) Guide application to be used at Hajj season would facilitate follow-up of campaign supervisors on their campaign’s safety and location. The systems would also allow H...Development and implementation of pilgrims (Hajj) Guide application to be used at Hajj season would facilitate follow-up of campaign supervisors on their campaign’s safety and location. The systems would also allow Hajj and Umrah administration to manage the crowd of the campaigns in an easy manner. In this paper, we propose Android/iPhone application that allows Hajj administration to monitor pilgrims using Quick Response Codes. Using quick response code application allows campaign supervisors and Hajj and Umrah employees to monitor pilgrims and guide them in case of getting lost. The application offers an easier and faster service than traditional approach used at Hajj season by human guidance. It is a very convenient service that would relief stresses of pilgrim’s relatives who worry about their relatives performing Hajj. The results show that the average score of our approach (QR) is 4.72 out of 5 comparing with traditional mobile applications indicating that the users are feeling enjoyable while using the new application features and the system is easy to use. Finally, the systems would assist in achieving the highest degree of pilgrims safety at Hajj season.展开更多
The pathogenic effect of Staphylococci is due to extra-cellular factors and properties such as adherence and biofilm production. The nature of the biofilm and the physiological properties of biofilm-producing bacteria...The pathogenic effect of Staphylococci is due to extra-cellular factors and properties such as adherence and biofilm production. The nature of the biofilm and the physiological properties of biofilm-producing bacteria result in an inherent antibiotic resistance and require further investigation. Two hundred and sixty Staphylococcal strains were cultured from 600 clinical specimens obtained from hospitalized patients. Among these, 155 were identified as coagulase-positive (CPS) and 105 as coagulase-negative (CNS) staphylococci. Staphylococcal strains were tested for biofilm production using the tissue culture plate (TCP) method. TCP detection showed that of the 155 CPS, 124 (80%) were biofilm producers, while 63 (60%) of the 105 CNS were biofilm producers. Biofilm-producing strains were scanned by scanning electron microscope (SEM) to confirm biofilm formation, study biofilm production, and examine antibiotic effects on biofilm formation. Disc diffusion method was used to study resistance of planktonic and biofilm-forming cells to antibiotics. Planktonic cells were less resistant to antibiotics than biofilm-forming cells. Microbroth dilution method and a new BioTimer assay were used to determine antibiotic MICs affecting planktonic and biofilm cells. Both methods showed that the MICs for planktonic cells were less than that for biofilm cells. The BioTimer assay was therefore found to be sensitive, accurate, and reliable, with results in agreement with those from the broth dilution method and SEM.展开更多
AIM: To investigate the effects of methyl palmitate and lutein on lipopolysaccharide(LPS)-induced acute lung injury(ALI) in rats and explore the possible mechanisms. METHODS: Male Sprague-Dawley rats were divided into...AIM: To investigate the effects of methyl palmitate and lutein on lipopolysaccharide(LPS)-induced acute lung injury(ALI) in rats and explore the possible mechanisms. METHODS: Male Sprague-Dawley rats were divided into 4 groups:(1) control;(2) LPS;(3) Methyl palmitate; and(4) Lutein groups. Methyl palmitate(300 mg/kg, ip) was administered 3 times per week on alternating days while lutein(100 mg/kg, oral) was given once daily. After 1 wk of vehicle/methyl palmitate/lutein treatment, ALI was induced by a single dose of LPS(7.5 mg/kg, iv). After 24 h of LPS injection, animals were sacrificed then biochemical parameters and histopathology were assessed. RESULTS: Treatment with methyl palmitate attenuated ALI, as it significantly decreased the lung wet/dry weight(W/D) ratio, the accumulation of the inflammatory cells in the bronchoalveolar lavage fluid(BALF) andhistopathological damage. However, methyl palmitate failed to decrease lactate dehydrogenase(LDH) activity in BALF. On the other hand, lutein treatment produced significant anti-inflammatory effects as revealed by significant decrease in accumulation of inflammatory cells in lung, LDH level in BALF and histopathological damage. Methyl palmitate and lutein significantly increased superoxide dismutase(SOD) and reduced glutathione(GSH) activities with significant decrease in the lung malondialdehyde(MDA) content. Importantly, methyl palmitate and lutein decreased the level of the inflammatory cytokine tumor necrosis factor-α(TNF-α) in the lung. Lutein also reduced LPS-mediated overproduction of pulmonary nitrite/nitrate(NO-2/NO-3), which was not affected by methyl palmitate pretreatment. CONCLUSION: These results demonstrate the potent protective effects of both methyl palmitate and lutein against LPS-induced ALI in rats. These effects can be attributed to potent antioxidant activities of these agents, which suppress inflammatory cell infiltration and regulated cytokine effects.展开更多
基金The Science,Technology&Innovation Funding Authority(STDF)in cooperation with The Egyptian Knowledge Bank(EKB).
文摘Nuclear fuel performance modeling and simulation are critical tasks for nuclear fuel design optimization and safety analysis under normal and transient conditions.Fuel performance is a complicated phenomenon that involves thermal,mechanical,and irradiation mechanisms and requires special multiphysics modules.In this study,a fuel performance model was developed using the COMSOL Multiphysics platform.The modeling was performed for a 2D axis-symmetric geometry of a UO2fuel pellet in the E110 clad for VVER-1200 fuel.The modeling considers all relevant phenomena,including heat generation and conduction,gap heat transfer,elastic strain,mechanical contact,thermal expansion,grain growth,densification,fission gas generation and release,fission product swelling,gap/plenum pressure,and cladding thermal and irradiation creep.The model was validated using a code-to-code evaluation of the fuel pellet centerline and surface temperatures in the case of constant power,in addition to validation of fission gas release(FGR)predictions.This prediction proved that the model could perform according to previously published VVER nuclear fuel performance parameters.A sensitivity study was also conducted to assess the effects of uncertainty on some of the model parameters.The model was then used to predict the VVER-1200 fuel performance parameters as a function of burnup,including the temperature profiles,gap width,fission gas release,and plenum pressure.A compilation of related material and thermomechanical models was conducted and included in the modeling to allow the user to investigate different material/performance models.Although the model was developed for normal operating conditions,it can be modified to include off-normal operating conditions.
文摘Studies of atmospheric dispersion are essential to both the site selection of a nuclear power plant and the evaluation of the environmental impacts of nuclear operations. Atmospheric stability plays the most important role in the dispersion of air pollutants. The focus of attention in the present study is the estimation of the degree of stability of the atmosphere for the north coast of Egypt to evaluate the ability of the atmosphere to disperse pollutants. A FORTRAN program （Appendix 1） is presented to determine atmospheric stability using the Pasquill-Tunner Method PTM, which defines the turbulent state of the atmosphere and also reflects upon the dispersion capabilities of the atmosphere at the site. This method used several meteorological factors such as wind speed, insulation, cloud cover height and type. Meteorological data from Matrouh stations in Egypt is applied for a simulated model. The total patterns of stability classification, both monthly and seasonal patterns, are determined, also the stability-wind rose and stability-wind summary are provided. Finally prediction of Iodine surface air concentration is reported as well as the annual effective dose for I- 131 as a case study.
文摘Prays oleae Bern, （OM） andPalpita unionalis Hfib., （JM） are two of the most important pests in olive groves in Egypt. A 3-year monitoring study using sex pheromone traps in semi-arid and arid olive groves was performed. In the semi-arid grove, flight pattern of the OM was the same as in other Mediterranean countries, but in dates concordating plant phenology. The moth completes three generations annually： the first flight is in March to April, the second is in May to June and the third occurs in August to October. In the arid olive grove, an interesting flight pattern was observed. First flight was always very close or overlapped with the second one with no male catches during August to October. However, eggs were present most of the season, indicating unusually high female presence and oviposition activity of the OM during the absence of males in the traps. Generally, moth densities were significantly lower in low fruiting years than in higher ones and were also lower in the arid olive grove than in the semi-arid one. In contrast, JM males were present all season, exhibiting six to seven and three to four overlapping flight peaks in arid and semi-arid olive groves, respectively. Moth densities were significantly higher in the arid olive grove than those in the semi-arid one. This study shows that trapping location and fruit beating year are characteristics that strongly affect the grove-specific information needed to estimate correctly adult emergence and thus the timing of control measures.
文摘Development and implementation of pilgrims (Hajj) Guide application to be used at Hajj season would facilitate follow-up of campaign supervisors on their campaign’s safety and location. The systems would also allow Hajj and Umrah administration to manage the crowd of the campaigns in an easy manner. In this paper, we propose Android/iPhone application that allows Hajj administration to monitor pilgrims using Quick Response Codes. Using quick response code application allows campaign supervisors and Hajj and Umrah employees to monitor pilgrims and guide them in case of getting lost. The application offers an easier and faster service than traditional approach used at Hajj season by human guidance. It is a very convenient service that would relief stresses of pilgrim’s relatives who worry about their relatives performing Hajj. The results show that the average score of our approach (QR) is 4.72 out of 5 comparing with traditional mobile applications indicating that the users are feeling enjoyable while using the new application features and the system is easy to use. Finally, the systems would assist in achieving the highest degree of pilgrims safety at Hajj season.
文摘The pathogenic effect of Staphylococci is due to extra-cellular factors and properties such as adherence and biofilm production. The nature of the biofilm and the physiological properties of biofilm-producing bacteria result in an inherent antibiotic resistance and require further investigation. Two hundred and sixty Staphylococcal strains were cultured from 600 clinical specimens obtained from hospitalized patients. Among these, 155 were identified as coagulase-positive (CPS) and 105 as coagulase-negative (CNS) staphylococci. Staphylococcal strains were tested for biofilm production using the tissue culture plate (TCP) method. TCP detection showed that of the 155 CPS, 124 (80%) were biofilm producers, while 63 (60%) of the 105 CNS were biofilm producers. Biofilm-producing strains were scanned by scanning electron microscope (SEM) to confirm biofilm formation, study biofilm production, and examine antibiotic effects on biofilm formation. Disc diffusion method was used to study resistance of planktonic and biofilm-forming cells to antibiotics. Planktonic cells were less resistant to antibiotics than biofilm-forming cells. Microbroth dilution method and a new BioTimer assay were used to determine antibiotic MICs affecting planktonic and biofilm cells. Both methods showed that the MICs for planktonic cells were less than that for biofilm cells. The BioTimer assay was therefore found to be sensitive, accurate, and reliable, with results in agreement with those from the broth dilution method and SEM.
文摘AIM: To investigate the effects of methyl palmitate and lutein on lipopolysaccharide(LPS)-induced acute lung injury(ALI) in rats and explore the possible mechanisms. METHODS: Male Sprague-Dawley rats were divided into 4 groups:(1) control;(2) LPS;(3) Methyl palmitate; and(4) Lutein groups. Methyl palmitate(300 mg/kg, ip) was administered 3 times per week on alternating days while lutein(100 mg/kg, oral) was given once daily. After 1 wk of vehicle/methyl palmitate/lutein treatment, ALI was induced by a single dose of LPS(7.5 mg/kg, iv). After 24 h of LPS injection, animals were sacrificed then biochemical parameters and histopathology were assessed. RESULTS: Treatment with methyl palmitate attenuated ALI, as it significantly decreased the lung wet/dry weight(W/D) ratio, the accumulation of the inflammatory cells in the bronchoalveolar lavage fluid(BALF) andhistopathological damage. However, methyl palmitate failed to decrease lactate dehydrogenase(LDH) activity in BALF. On the other hand, lutein treatment produced significant anti-inflammatory effects as revealed by significant decrease in accumulation of inflammatory cells in lung, LDH level in BALF and histopathological damage. Methyl palmitate and lutein significantly increased superoxide dismutase(SOD) and reduced glutathione(GSH) activities with significant decrease in the lung malondialdehyde(MDA) content. Importantly, methyl palmitate and lutein decreased the level of the inflammatory cytokine tumor necrosis factor-α(TNF-α) in the lung. Lutein also reduced LPS-mediated overproduction of pulmonary nitrite/nitrate(NO-2/NO-3), which was not affected by methyl palmitate pretreatment. CONCLUSION: These results demonstrate the potent protective effects of both methyl palmitate and lutein against LPS-induced ALI in rats. These effects can be attributed to potent antioxidant activities of these agents, which suppress inflammatory cell infiltration and regulated cytokine effects.
