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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

Electrical Performance Study of a Large Area Multicrystalline Silicon Solar Cell Using a Current Shunt and a Micropotentiometer

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Engineering（科研） 2010年第4期2卷 263-269页

作者： Hala mohamed abdel Mageed Ahmed Faheem Zobaa Ahmed Ghitas mohamed Helmy abdel Raouf mohamed Sabry Abla Hosni Abd El-Rahman mohamed mamdouh abdel aziz 不详

In this paper, a new technique using a Current Shunt and a Micropotentiometer has been used to study the electrical performance of a large area multicrystalline silicon solar cell at outdoor conditions. The electrical performance is mainly described by measuring both cell short circuit current and open circuit voltage. The measurements of this cell by using multimeters suffer from some problems because the cell has high current intensity with low output voltage. So, the solar cell short circuit current values are obtained by measuring the voltage developed across a known resistance Current Shunt. Samples of the obtained current values are accurately calibrated by using a Micropotentiometer (μpot) thermal element (TE) to validate this new measuring technique. Moreover, the solar cell open circuit voltage has been measured. Besides, the cell output power has been calculated and can be correlated with the measured incident radiation.

关键词： Large Area Multicrystalline Silicon Solar Cell Current Measurements Calibration Current Shunt Micropotentiometer Short Circuit Current Open Circuit Voltage

Mitigating diabetes-related complications:Empowering metformin with cholecalciferol and taurine supplementation in type 2 diabetic rats

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World Journal of Diabetes 2024年第8期15卷 1778-1792页

作者： Mai S Attia Fadwa Ayman mohamed S Attia Galal Yahya Mansour H Zahra Magdi mohamed Ibrahim Khalil abdel aziz A Diab Department of Zoology Faculty of ScienceZagazig 44519Egypt Department of Pharmaceutics Faculty of PharmacyZagazig 44519Egypt Department of Microbiology and Immunology Faculty of PharmacyZagazig UniversityZagazig 44519Egypt Department of Biochemistry Faculty of MedicineZagazig 44519Egypt

BACKGROUND Type 2 diabetes is one of the most prevalent chronic diseases worldwide,significantly impacting patients'quality of *** treatment options like metformin(MET)effectively counteract hyperglycemia but fail to alleviate diabetes-associated complications such as retinopathy,neuropathy,nephropathy,hepatopathy,and cardiovascular *** To propose the supplementation of cholecalciferol(CHO)and taurine(TAU)to enhance MET efficacy in controlling diabetes while minimizing the risk of associated *** The study involved sixty rats,including ten non-diabetic control rats and fifty experimental rats with type 2 diabetes induced by *** experimental rats were further subdivided into positive control and treatment *** four treatment groups were randomly allocated to a single MET treatment or MET combined with supplements either CHO,TAU,or *** Diabetic rats exhibited elevated levels of glucose,insulin,Homeostasis Model Assessment of Insulin Resistance(HOMA-IR),glycated hemoglobin percentage,lipid markers,aspartate aminotransferase,and malondialdehyde,along with reduced levels of antioxidant enzymes(catalase and superoxide dismutase).The administration of CHO and TAU supplements alongside MET in diabetic rats led to a noticeable recovery of islet *** antioxidative,anti-inflammatory,and anti-apoptotic properties of the proposed combination therapy significantly ameliorated the aforementioned *** The supplementation of CHO and TAU with MET showed the potential to significantly improve metabolic parameters and protect against diabetic complications through its antioxidative,anti-inflammatory,and antiapoptotic effects.

关键词： Diabetes complications Metformin Cholecalciferol Taurine Glycated hemoglobin% Antioxidant

Microbial,immune and antioxidant responses of Nile tilapia with dietary nano-curcumin supplements under chronic low temperatures

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Aquaculture and Fisheries 2024年第1期9卷 57-65页

作者： Mohammed F.El Basuini mohamed A.A.Zaki abdelaziz M.El-Hais mohamed G.Elhanafy Emad H.El-Bilawy Amr I.Zaineldin mohamed F.A.abdel-aziz Ibrahim A.Abouelsaad Ibrahim TEl-Ratel Kumbukani Mzengereza Ronick S.Shadrack Islam I.Teiba Faculty of Agriculture Tanta UniversityTanta31527Egypt King Salman International University South Sinai46618Egypt Faculty of Agriculture Alexandria UniversityAlexandria21526Egypt Animal Health Research Institute(AHRI-DOKI) Agriculture Research CenterGiza12619Egypt Fish Rearing Lab. Aquaculture DivisionNational Institute of Oceanography and FisheriesAlexandria21556Egypt Horticulture Department Faculty of AgricultureDamanhour UniversityDamanhur22511Egypt Department of Poultry Production Faculty of AgricultureDamietta UniversityDamietta34517Egypt Laboratory of Aquatic Animal Nutrition Faculty of FisheriesKagoshima UniversityKagoshima890-0065Japan Department of Aquatic and Fisheries Science Mzuzu UniversityMzuzuPrivate Bag 201Malawi Faculty of Aquaculture and Marine Fisheries Arish UniversityArish45516Egypt

A 56-day feeding period was performed to investigate the possible impacts of dietary nano curcumin(0,50,100,150,and 200 ppm)on the growth,nutrient utilization,non-specific immune parameters,antioxidants in Nile tilapia under chronic low temperature(21.02±0.11◦C).Fishes(n=225;Initial weight=4.39±0.08 g/fish)were randomly stocked at 15 fish/tank for five experimental groups in *** low-temperature circumstances,dietary curcumin in nano form showed no notable alteration in growth variable,nutrient efficiency,digestive enzymes efficiency,biometric indices,survival rates,and hematological ***,the serum of fishes with nano curcumin diets under low-temperature stress displayed higher total protein as well as lower glucose,cortisol,and total cholesterol compared with the control ***,fish fed nano curcumin diets displayed higher lysozyme and bactericidal activities compared to the control group and the best performance was found at dietary nano curcumin level of≥100 ***,groups fed the basal diet demonstrated the poorest antioxidant capacity,and the best superoxide dismutase(SOD)and glutathione peroxidase(GPx)existed in fish with nano curcumin diets while the best catalase(CAT)efficiency occurred at higher nano curcumin levels≥100 *** addition,higher counts of intestinal microbiota in terms of total bacterial count(TBC),total yeast and molds count(TYMC),and coliform were noticed in fish consumed the basal diet compared to groups fed on nano curcumin *** conclusion,incorporating nano curcumin at a level of≥100 mg/kg diet(particularly at 150 mg/kg)improved a non-specific immune response,antioxidant,and healthier gastrointestinal microbiota in Nile tilapia under chronic low-temperature stress.

关键词： Nano curcumin Gastrointestinal microbiota Antioxidants Non-specific immune responses Temperature stress

Flavonoid chemical composition and antidiabetic potential of Brachychiton acerifolius leaves extract

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Asian Pacific Journal of Tropical Biomedicine 2017年第5期7卷 389-396页

作者： Aisha Hussein Abou Zeid mohamed Ali Farag Manal abdel aziz Hamed Zeinab abdel aziz Kandil Radwa Hassan El-Akad Hanaa mohamed El-Rafie Pharmacognosy Department National Research Centre Pharmacognosy Department College of PharmacyCairo University Therapeutic Chemistry Department National Research Centre

Objective:To evaluate Brachychiton acerifolius leaf extracts as antidiabetic potential agent and to identify the main active constituents using bioactivity guided ***:In vitro antioxidant activity was evaluated for *** different extracts using DPPH assay and vitamin C as *** activity was then determined using STZ-induced rats treated daily with ethyl acetate and 70% ethanol leaf extracts for4 weeks at a dose of 200 g/kg body weight against gliclazide reference *** glucose,a-amylase,lipid profile,liver function enzymes and oxidative stress markers were assessed along with histopathological study for liver and pancreatic *** and structural elucidation of active compounds were made using Diaion and Sephadex followed by spectral ***:The results indicated that ethyl acetate and ethanol leaf extracts exhibited the strongest antioxidant activity compared to that of vitamin C(IC500.05,0.03 and 12 mg/m L,respectively).Both extracts showed potent anti-hyperglycemic activity evidenced by a significant decrease in serum glucose levels by 82.5% and 80.9% and a-amylase by45.2% and 53.6%,as compared with gliclazide 68% and 59.4%,*** of ethanol extract resulted in the isolation of 9 flavonoids including apigenin-7-O-arhamnosyl(1/2)-b-D-glucuronide,apigenin-7-O-b-D-glucuronide,apigenin-7-O-b-Dglucoside and ***:This study highlights the potential use of *** leaf extract enriched in flavones for the treatment of diabetes that would warrant further clinical trials investigation.

关键词： STZ-induced diabetes Diaion fractionation Flavonoid glucuronides Brachychiton acerifolius

Antifouling evaluation of extracts from Red Sea soft corals against primary biofilm and biofouling

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Asian Pacific Journal of Tropical Biomedicine 2017年第11期7卷 991-997页

作者： Yosry abdel aziz Soliman Ahmed Mohammed Brahim Ahmed Hussein Moustafa mohamed abdel Fattah Hamed Marine Chemistry Lab. Marine Environment DivisionNational Institute of Oceanography and FisheriesSuezEgypt Department of Chemistry Faculty of ScienceZagazig UniversityZagazigEgypt

Objectives: To evaluate antifouling property of extracts from Red Sea soft corals against primary biofilm and ***: Seven species of soft corals Sarcophyton glaucum(a), Sinularia compressa,Sinularia cruciata(a), Heteroxenia fuscescens(a), Sarcophyton glaucum(b), Heteroxenia fuscescens(b) and Sinularia cruciata(b) were chosen to test their extracts as antibacterial and antifouling agents in Eastern Harbour of Alexandria, Mediterranean *** compounds of soft corals were extracted by using methanol and concentrated under vacuum. The residues of extracts were mixed in formulation of inert paint which consisted of rosin, chlorinated rubber and ferrous oxide against micro and macro fouling organisms. The formulated paints were then applied on PVC panels twice by brush,hanged in a steel frame and immersed in Eastern Harbour of Alexandria Mediterranean Sea followed by visual inspection and photographic ***: After 185 days of immersion in seawater, the antifouling results agreed with the antibacterial results where extracts of Sinularia compressa and Heteroxenia fuscescens(b) gave the best activity against marine fouling tubeworms and barnacles. The inhibition activity was correlated with the major functional groups(hydroxyl, amino, carbonyl,aliphatic(fatty acids), C]C of alkene or aromatic rings and CeC l of aryl halides) of the ***: The strong antifouling activity makes them promising candidates for new antifouling additives. After the screening and application of natural organic compounds from soft corals, marine organisms show activity against micro and macro fouling organisms.

关键词： Antibacterial Antifouling Paints Seawater Marine Organisms

Isolation, purification and structure elucidation of three newbioactive secondary metabolites from Streptomyces lividans AM

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BIOCELL 2021年第5期45卷 1263-1271页

作者： MOHAMMAD EL-METWALLY mamdouh abdel-MOGIB MANAL ELFEDAWY GAAD SOHSAH AHMED REZK MAHMOUD MOUSTAFA mohamed SHAABAN Botany and Microbiology Department Faculty of ScienceDamanhour UniversityDamanhour22511Egypt Chemistry Department Faculty of ScienceMansoura UniversityEl-Mansoura35516Egypt Bioprocess Development Department Genetic Engineering and Biotechnology Research InstituteCity of Scientific Research and Technological Applications(SRTA-City)New Borg El-Arab CityAlexandria21934Egypt Biology Department College of ScienceKing Khalid UniversityAbha9004Saudi Arabia Chemistry of Natural Compounds Department Division of Pharmaceutical IndustriesNational Research CentreDokki-Cairo12622Egypt Organic and Bioorganic Chemistry Department of ChemistryBielefeld UniversityBielefeld33615Germany

Microorganisms are a huge mine of bioactive metabolites,and actinomycetes are one of the very active groups in this *** this article,we are concerned about the full taxonomical characterization of Streptomyces lividans AM,isolated from Egyptian *** isolate produced three new bioactive metabolites,namely:1-Nona-decanoyl,4-oleyl disuccinate(1),filoboletic acid;(9Z,11E)-8,13-dihydroxy octadeca-9,11-dienoic acid(2),and sitosteryl-3β-D-glucoside(3).Extensive 1D and 2D NMR and HR-mass spectrometry were used to elucidate the structures of the three ***,ten known compounds were also *** antimicrobial activity of the producing organism and newly reported compounds(1–3)was investigated against a selected group of pathogenic microorganisms.A full taxonomical characterization of the strain was described as well.

关键词： Bioactive metabolites Streptomyces sp. Taxonomy Biological activity

Cartilage tympanoplasty in the treatment of adhesive otitis media with and without Eustachian tube balloon dilatation

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Journal of Otology 2022年第4期17卷 226-231页

作者： Ahmed abdel rahman abdel aziz Ahmed Mahmoud Youssef Mostafa mohamed Mostafa Mostafa talaat Khaled mohamed abdelzaher Ahmed Adel Sadeq Department of Otorhinolaryngology Faculty of MedicineEl MiniaEgypt Radiology Department Faculty of MedicineEl MiniaEgypt

Purpose:To compare cartilage tympanoplasty(CT)combined with eustachian tube balloon dilatation(ETBD)and cartilage tympanoplasty alone as a surgical treatment modality for adhesive otitis media(AdOM)in terms of graft healing,audiological outcomes,and impact on life style,using Chronic Otitis Media Outcome Test 15(COMOT-15).Methods:50 patients with AdOM were randomly classified into 2 groups:25 patients for cartilage tympanoplasty only(CT group)and 25 patients for cartilage tympanoplasty combined with eustachian tube balloon dilatation(CT t ETBD group).Clinical outcomes in both groups were compared at 3 and 6 months of follow ***:There was no significant difference in graft healing between the two *** COMOT-15 scores significantly decreased in both groups with a significant difference between the groups with regard to the decrease in COMOT-15 scores at 3 and 6 months of follow-up(P<0.05).Hearing improvement was achieved,as the mean preoperative ABG was 26.5±5.4 and 27.1±4.6 dB,and the mean postoperative ABG at 6 months was 19.4±4.4 and 14.6±3.9 dB in the CT and the CT t ETBD groups,*** difference in the magnitude of ABG reduction in the two groups was significant at 3 and 6 months of postoperative follow-up(P<0.05)in favour of the CT t ETBD ***:ETBD can increase the success rate of cartilage tympanoplasty in patients with AdOM by enhancing the audiological outcome and quality of life.

关键词： balloon healing otitis