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Journal of Coastal Life Medicine 2015年第10期 797-800页

作者： Yassir Sulieman abdel-aziz AAhmed Azzam Afifi Theerakamol Pengsakul Department of Zoology Faculty of Science and TechnologyUniversity of ShendiSudan Department of Zoology Faculty of ScienceUniversity of KhartoumSudan Department of Zoology Faculty of Science and TechnologyOmdurman Islamic UniversitySudan Faculty of Medical Technology Prince of Songkla UniversityHat YaiSongkhla 90110Thailand

Objective:To investigate the predation efficacy of the freshwater leech,Limnatis nilotica(***)as a potential biological control agent against different stages of the Bulinus truncatus(***),the intermediate host of human Schistosoma haematobium,under laboratory ***:The leech *** and the snail *** were collected from El Kiryab Agriculture Scheme,***,the predatory activity of the leech was evaluated against eggs,neonates and adults of the snail in a series of different experiments under laboratory ***:The findings showed that the *** leech was a voracious predator towards the eggs and neonates of *** snails with a shell length of up to 3 mm,as well as of adult snails with an shell length greater than 3 ***:The results showed that *** had a significant impact on *** ***,long term studies under natural field conditions are needed to support these results.

关键词： Bulinus truncatus snail Limnatis nilotica leech Biological control Schistosomiasis

Temperature Effects on the Electrical Performance of Large Area Multicrystalline Silicon Solar Cells Using the Current Shunt Measuring Technique

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Engineering（科研） 2010年第11期2卷 888-894页

作者： Hala Mohamed abdel Mageed Ahmed Faheem Zobaa Mohamed Helmy abdel Raouf Abla Hosni Abd El-Rahman Mohamed Mamdouh abdel aziz 不详

The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shunt measuring technique. Therefore, most of the problems encountered with traditional measuring techniques are avoided. The temperature dependency of the current shunt from 5oC up to 50oC has been investigated. Its temperature coefficient proves to be negligible which means that the temperature dependency of the solar cell is completely independent of the current shunt. The solar module installed in a tilted position at the optimum angle of the location, has been tested in two different seasons (winter and summer). The obtained solar cell short circuit current, open circuit voltage and output power are correlated with the measured incident radiation in both seasons and all results are discussed.

关键词： Large Area Multicrystalline Silicon Solar Cell Current Shunt Measuring Technique Temperature Effects Short Circuit Current Open Circuit Voltage Accumulated Power Incident Radiation

An Improved Design of a Fully Automated Multiple Output Micropotentiometer

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Energy and Power Engineering 2010年第2期2卷 103-110页

作者： Hala Mohamed abdel Mageed Ahmed Faheem Zobaa Mohamed Helmy abdel Raouf Abla Hosni Abd El-Rahman Mohamed Mamdouh abdel aziz National Institute for Standards GizaEgypt University of Exeter ExeterUK Cairo University GizaEgypt

This paper describes in details a new design of a fully automated multiple output micropotentiometer (?pot). A prototype has been built at the National Institute for Standards (NIS), Egypt to establish this highly improved AC voltage source in the millivolt range. The new device offers three different outputs covering a wide frequency range from only one outlet. This valuably supports the precise sourcing ranges of low AC voltage at NIS. The design and the operation theory of this prototype have been discussed in details. An automatic calibration technique has been introduced through specially designed software using the LabVIEW program to enhance the calibration technique and to reduce the uncertainty contributions. Relative small AC-DC differences of our prototype in the three output ranges are fairly verified. The expanded uncertainties of the calibration results for the three output ranges have been faithfully estimated. However, further work is needed to achieve the optimum performance of this new device.

关键词： Multiple Output μpot AC-DC Transfer Standard Single Junction Thermal Converter Calibration Uncertainty

Seroprevalence and Associated Risk Factors of Peste des Petits Ruminants among Sheep and Goats in Kassala State, Sudan

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Open Journal of Animal Sciences 2018年第4期8卷 381-395页

作者： Fatima A. Saeed Sana A. abdel-aziz Mohammed M. Gumaa Kassala Veterinary Research Laboratory Animal Resources Research Corporation Ministry of Animal Resources Khartoum Sudan Department of Microbiology Faculty of Veterinary Medicine University of Khartoum Khartoum Sudan

Peste des petits ruminant (PPR) is a contagious disease of small ruminants caused by a virus that belongs to the genus Morbillivirus of the family Paramyxoviridae. This study aimed to determine the seroprevalence of PPR disease in sheep and goats and its associated risk factors in Kassala State, Eastern Sudan. Across sectional study was conducted during the period from 30th August to 25th November 2015. The study was carried out using a structured questionnaire survey and a total of 918 blood samples were collected from apparently healthy unvaccinated sheep and goats in different localities in State of Kassala. A total of 546 sheep and 372 goats were tested for specific antibodies to nucleoprotein (NP) by competitive enzyme linked immunosorbent assay (cELISA). The apparent overall prevalence of PPR antibodies in Kassala was 58.2% while the true prevalence was calculated to be 61.3%. The apparent prevalence in sheep and goats was 68.1% and 43.5% respectively. Univariate analysis showed that the risk factors had significant associations with a cELISA positive status: locality, species, age, breed, husbandry system, housing mode, animals movement (p = 0.000) and animals sharing pasture and water (p = 0.003), while sex and newly introduced animals were not significant risk factors (p = 0.771) (p = 0.050) respectively. Factors found that significantly associated (p < 0.05) with increased odds of being cELISA positive in multivariate analysis were localities, species, age and newly introduced animals. The prevalence differed between localities and was the highest in the River Atbara (84.0%) locality, whereas it was lowest in Delta North (29.0%). No significant difference was observed among the sexes. However, the prevalence differed in different age groups and was 52.25% in animals of less than six months old;49.3% were between seven months and two years old and 65.5% were above two years old. In different husbandry systems, the prevalence was 47.9%, 73.0% and 49.2% in in

关键词： Peste des Petits Ruminants Sero-Prevalence Risk Factors Kassala State Sudan

Process Simulation of a 620 Mw-Natural Gas Combined Cycle Power Plant with Optimum Flue Gas Recirculation

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Open Journal of Energy Efficiency 2018年第2期7卷 33-52页

作者： Ahmed Badr Al Hashmi abdel aziz Abdulla Mohamed Zin Eddine Dadach Chemical & Petroleum Engineering Department Abu Dhabi Men’s College Higher Colleges of Technology Abu Dhabi UAE

The main objective of this investigation is to obtain an optimum value for the flue gas recirculation ratio in a 620 MW-Natural Gas Combined Cycle (NGCC) power plant with a 100% excess air in order to have a composition of the exhaust gas suitable for an effective absorption by amine solutions. To reach this goal, the recirculated flue gas is added to the secondary air (dilution air) used for cooling the turbine. The originality of this work is that the optimum value of a Flue Gas Recirculation (FGR) ratio of 0.42 is obtained from the change of the slope related to the effects of flue gas recirculation ratio on the molar percentage of oxygen in the exhaust gas. Compared to the NGCC power plant without flue gas recirculation, the molar percentage of carbon dioxide in the flue gas increases from 5% to 9.2% and the molar percentage of oxygen decreases from 10.9% to 3.5%. Since energy efficiency is the key parameter of energy conversion systems, the impact of the flue gas recirculation on the different energy inputs and outputs and the overall efficiency of the power plant are also investigated. It is found the positive effects of the flue gas recirculation on the electricity produced by the steam turbine generator (STG) are more important than its cooling effects on the power output of the combustion turbine generator (CTG). The flue gas recirculation has no effects on the water pump of the steam cycle and the increase of energy consumed by the compressor of flue gas is compensated by the decrease of energy consumed by the compressor of fresh air. Based on the Low heating value (LHV) of the natural gas, the flue gas recirculation increases the overall efficiency of the power plant by 1.1% from 57.5% from to 58.2%.

关键词： Natural Gas Combined Cycle (NGCC) Flue Gas Recirculation Absorption by Amine CCS

Endoscopic Third Ventriculostomy versus Ventriculo-Peritoneal Shunt for Infant Hydrocephalus

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Open Journal of Modern Neurosurgery 2020年第2期10卷 193-202页

作者： Khaled Ismail abdel-aziz Radwan Nouby Mahmoud Ahmed Thabet Mohammad Fekry Elshirbiny Department of Neurosurgery Faculty of Medicine Aswan University Aswan Egypt Department of Neurosurgery Faculty of Medicine Assiut University Assiut Egypt

Introduction: Patients with hydrocephalus, which is the most pediatric neurological disorder, undergo Cerebrospinal fluid (CSF) diversion through third ventriculostomy or ventriculo-peritoneal shunt. Up to date, the optimal hydrocephalus treatment modality is not clear. Aim: We compared the outcome of endoscopic third ventriculostomy (ETV) versus ventriculo-peritoneal shunt (VP shunt) as a second surgical intervention in management of Infant hydrocephalus concerning success rate and complications. Patients and Methods: We conducted an observational study of 52 children with hydrocephalus (congenital or acquired) in whom CSF diversion was performed using either ETV or VP shunt in randomized control trial. Results: During the period examined, 52 children, 26 underwent ETV and 26 underwent VP shunt. The mean age was 11.0 ± 4.3 months in ETV and 11.3 ± 4.7 months in VP shunt. Postoperative infection in the ETV group was lower than in the VP shunt group (23.1% vs. 53.8% P = 0.045). Regarding operating time, In ETV group operation duration was 46.9 min and 64.3 min in the V-P shunt group (P = 0.13). There was no statistically significant difference between the two study groups regarding the rate of obstruction, change in occipital frontal circumference (OFC) or the need of revision surgery. One year survival for VP shunt group vs. ETV group was 46.2% vs. 65.4% respectively. Conclusion: ETV associated with lower rates of postoperative infection and shorter operation time with no significant difference in rates of obstruction, change in OFC and revision surgery in comparison to VP shunt.

关键词： ETV VPS Pediatric Hydrocephalus

Elevated Temperatures Tensile Characteristics of Cast A356/Al2O3Nanocomposites Fabricated Using a Combination of Rheocasting and Squeeze Casting Techniques

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Materials Sciences and Applications 2011年第5期2卷 390-398页

作者： El-Sayed Youssef El-Kady Tamer Samir Mahmoud Mohamed abdel-aziz Sayed 不详

In the present investigation, the tensile properties of A356/Al2O3 nanocomposites at both ambient and elevated temperatures were studied. The A356/Al2O3 nanocomposites were fabricated using a combination between the rheocasting and squeeze casting techniques. The A356 matrix alloy was reinforced with Al2O3 nanoparticulates having average sizes of 60 nm and 200 nm with different volume fractions up to 5 vol%. The results revealed that the A356/Al2O3 nanocomposites exhibited better mechanical properties than the A356 monolithic alloy. Such improvement in the mechanical properties was observed at both room and elevated temperatures up to 300°C. Increasing the volume fraction and/or reducing the size of Al2O3 nanoparticulates increase both the tensile and yield strengths of the nanocomposites.

关键词： Nanocomposites Mechanical Properties Rhecocasting Squeeze Casting Aluminum Alloys

Directional Overcurrent Relays Coordination Restoration by Reducing Minimum Fault Current Limiter Impedance

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Journal of Energy and Power Engineering 2014年第6期8卷 1132-1141页

作者： Saadoun abdel aziz Mostafa DoaaKhalil Ibrahim Essam El-Din Abo El-Zahab Arab Contractor Company Nasr City 11852 Egypt Faculty of Engineering Cairo University Giza 12613 Egypt

FCL （fault current limiter） is used to solve relays miscoordination problem arises from DG （distributed generation） installation. In most published researches, different optimization methods are developed to obtain optimal relay settings to achieve coordination in case of not installing DG, then depending on the achieved optimal obtained relay settings, FCL impedance is deduced to ensure relays coordination restoration in case of installing DG. Based on original optimal relay settings, obtained FCL impedance is not the minimum one required to achieve relay coordination. The contribution of this paper is the generation of multi sets of original relay settings that increase the possibility of finding FCL impedance of minimum value which is lower than the calculated value based on original optimal relay settings. The proposed method achieves better economic target by reducing FCL impedance. The proposed approach is implemented and tested on IEEE-39 bus test system.

关键词： FCL (fault current limiter) IP (pickup current setting) relays coordination TDS (time-dial setting).

Characteristics of escape mutations from occult hepatitis B virus infected patients with hematological malignancies in South Egypt

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World Journal of Hepatology 2017年第9期9卷 477-486页

作者： Abeer Elkady Sayuki Iijima Sahar Aboulfotuh Elsayed Mostafa Ali Douaa Sayed Nashwa M abdel-aziz Amany M Ali Shuko Murakami Masanori Isogawa Yasuhito Tanaka Department of Clinical and Chemical Pathology Medical School of South Valley University Department of Virology and Liver Unit Nagoya City University Graduate School of Medical Sciences Department of Clinical and Chemica Pathology Medical School of Sohag University Department of Medical Oncology Medical School of Sohag University Department of Clinical and Chemical Pathology South Egypt Cancer Institute Department of Medical Oncology South Egypt Cancer Institue

AIM To investigate the prevalence and virological characteristics of occult hepatitis B virus(HBV) infections in patients with hematological malignancies in South *** Serum samples were collected from 165 patients with hematological malignancies to monitor titers of HBV DNA, hepatitis B surface antigen(HBs Ag), and antibodies to HBV core(anti-HBc) and surface antigens. Serum samples negative for HBs Ag and positive for anti-HBc were subjected to nucleic acid extraction and HBV DNA detection by real-time polymerase chain reaction. DNA sequences spanning the S region were analyzed in cases with occult HBV infection. In vitro comparative study of constructed 1.24-fold wild type and S protein mutant HBV genotype D clones was further performed. RESULTS HBV DNA was detected in 23(42.6%) of 54 patients with hematological malignancies who were HBsA g negative, but anti-HBc positive, suggesting the presence of occult HBV infection. The complete HBV genome was retrieved from 6 occult HBV patients, and P120 T and S143 L were detected in 3 and 2 cases, respectively. Site directed mutagenesis was done to produce 1.24-fold genotype D clones with amino acid mutations T120 and L143. The in vitro analyses revealed that a lower level of extracellular HBsA g was detected by chemiluminescence enzyme immunoassay(CLEIA) with the clone containing T120 mutation, compared with the wild type or the clone with S143 L mutation despite the similar levels of extracellular and intracellular HBs Ag detected by Western blot. Southern blot experiments showed that the levels of intracellular HBV DNA were not different between these clones. CONCLUSION Occult HBV infection is common in patients with hematological malignancies and associated with P120 T and S143 L mutations. 120 T mutation impairs the detection of HBsA g by CLEIA.

关键词： Occult hepatitis B infection Hematological malignancies Escape mutation

On the Electrical and Thermal Conductivities of Cast A356/Al2O3Metal Matrix Nanocomposites

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Materials Sciences and Applications 2011年第9期2卷 1180-1187页

作者： El-Sayed Youssef El-Kady Tamer Samir Mahmoud Ali abdel-aziz Ali 不详

To assess the effect of the dispersion of Al2O3 nanoparticles into A356 Al alloy on both the electrical and thermal conductivities, A356/Al2O3 metal matrix nanocomposites (MMNCs) were fabricated using a combination of rheocasting and squeeze casting techniques. Two different sizes of Al2O3 nanoparticles were dispersed into the A356 Al alloy, typically, 60 and 200 nm with volume fractions up to 5 vol%. The effect of the nanoparticles size and volume fraction on the electrical and thermal conductivities was evaluated. The results revealed that the A356 monolithic alloy exhibited better electrical and thermal conductivities than the MMNCs. Increasing the nanoparticles size and/or the volume fraction reduces both the thermal and electrical conductivities of the MMNCs. The maximum reduction percent in the thermal and electrical conductivities, according to the A356 monolithic alloy, were about 47% and 38%, respectively. Such percentages were exhibited by A356/Al2O3MMNCs containing 5 vol% of nanoparticles having 60 and 200 nm, respectively.

关键词： Nanocomposites Thermal Conductivity Electrical Conductivity Aluminum Alloys