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Efficient PbS quantum dots tandem solar cells through compatible interconnection layer

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Journal of Energy Chemistry 2024年第11期98卷 47-57页

作者： Gomaa mohamed Gomaa khalaf Xinzhao Zhao Mingyu Li Chunxia Li Salman Ali Tianjun Ma Hsien-Yi Hsu Jianbin Zhang Haisheng Song Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and Technology(HUST)Wuhan 430074HubeiChina Solar and Space Department National Research Institute of Astronomy and Geophysics(NRIAG)HelwanCairoEgypt School of Energy and Environment&Department of Materials Science and Engineering City University of Hong KongKowloon TongHong Kong 999077China School of Integrated Circuits Huazhong University of Science and TechnologyWuhan 430074HubeiChina Optics Valley Laboratory Wuhan 430074HubeiChina

Lead sulfide quantum dots(PbS QDs) hold unique characteristics, including bandgap tunability, solutionprocessability etc., which make them highly applicable in tandem solar cells(TSCs). In all QD TSCs, its efficiency lags much behind to their single junction counterparts due to the deficient interconnection layer(ICL) and defective subcells. To improve TSCs performance, we developed three kinds of ICL structures based on 1.34 and 0.96 e V PbS QDs subcells. The control, 1,2-ethanedithiol capped PbS QDs(PbS-EDT)/Au/tin dioxide(SnO_(2))/zinc oxide(Zn O), utilized SnO_(2) layer to obtain high surface ***, its energy level mismatch causes incomplete recombination. Bypassing it, the second ICL(PbS-EDT/Au/Zn O) removed SnO_(2) and boosted the power conversion efficiency(PCE) from 5.75% to 8.69%. In the third ICL(PbS-EDT/poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA)/Au/Zn O), a thin layer of PTAA can effectively fill fissures on the surface of PbS-EDT and also protect the front cells from solvent penetration. This TSC obtained a PCE of 9.49% with an open circuit voltage of 0.91 V, a short circuit current density of 15.47 m A/cm~2, and a fill factor of 67.7%. To the best of our knowledge, this was the highest PCE achieved by all PbS QD TSCs reported to date. These TSCs maintained stable performance for a long working time under ambient conditions.

关键词： Quantum dots Tandem solar cell Interconnection layer Hysteresis Defect

Stable PbS colloidal quantum dot inks enable blade‑coating infrared solar cells

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Frontiers of Optoelectronics 2023年第3期16卷 131-140页

作者： Xinzhao Zhao Mingyu Li Tianjun Ma Jun Yan Gomaa mohamed Gomaa khalaf Chao Chen Hsien‑Yi Hsu Haisheng Song Jiang Tang Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and Technology(HUST)Wuhan 430074China School of Optical and Electronic Information Huazhong University of Science and Technology(HUST)Wuhan 430074China School of Energy and Environment and Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China Wenzhou Advanced Manufacturing Technology Research Institute of Huazhong University of Science and Technology Wenzhou 325035China

Infrared solar cells are more efective than normal bandgap solar cells at reducing the spectral loss in the near-infrared region,thus also at broadening the absorption spectra and improving power conversion *** colloidal quantum dots(QDs)with tunable bandgap are ideal infrared photovoltaic ***,QD solar cell production sufers from small-areabased spin-coating fabrication methods and unstable QD ***,the QD ink stability mechanism was fully investigated according to Lewis acid–base theory and colloid stability *** further studied a mixed solvent system using dimethylformamide and butylamine,compatible with the scalable manufacture of method-blade *** on the ink system,100 cm2 of uniform and dense near-infrared PbS QDs(~0.96 eV)flm was successfully prepared by blade *** average efciencies of above absorber-based devices reached 11.14%under AM1.5G illumination,and the 800 nm-fltered efciency achieved 4.28%.Both were the top values among blade coating method based *** newly developed ink showed excellent stability,and the device performance based on the ink stored for 7 h was similar to that of fresh *** matched solvent system for stable PbS QD ink represents a crucial step toward large area blade coating photoelectric devices.

关键词： PbS quantum dots Solvent engineering Colloid stability Blade coating Infrared solar cells

Purification of Produced Water from a Sour Oilfield in South Kuwait. 1. Oil-Water Separation and Industrial Salt Production

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Journal of Water Resource and Protection 2024年第2期16卷 156-180页

作者： Feras Al Salem Hessa Al Shamsi Mariam Mohammed Abdulla Alaryani Basmalah Abdelazim mohamed khalaf Omnia Elsheikh Vijo Poulose Yosef Al Jasem Thies Thiemann Department of Biology United Arab Emirates University Al Ain United Arab Emirates Department of Chemistry United Arab Emirates University Al Ain United Arab Emirates Department of Process & Design Engineering Solid Mechanical Equipment Co Abu Dhabi United Arab Emirates

Produced water from an oil extraction site in South Kuwait was sampled after primary oil – water separation had been carried out. The produced water was filtered through a mixture of activated charcoal and esterified cellulosic material gained from spent coffee grounds as a tertiary adsorption treatment. The earth-alkaline metal ions and heavy metals were separated from the de-oiled produced water by addition of either sodium or potassium hydroxide in the presence of carbon dioxide or by direct addition of solid sodium carbonate. The resulting filtrate gave salt of industrial purity upon selective crystallization on evaporation.

关键词： Produced Water Oil and Gas Adsorption Filtration Crystallization

Co-combustion of RDF and biomass mixture with bituminous coal:a case study of clinker production plant in Egypt

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Waste Disposal and Sustainable Energy 2021年第4期3卷 257-266页

作者： Osayed Sayed mohamed Abu‑Elyazeed mohamed Nofal khalaf Ibrahim Junfeng Yang Mechanical Power Engineering Department Faculty of EngineeringMatariaHelwan UniversityMasaken El-HelmiyaP.O.11718CairoEgypt School of Mechanical Engineering University of LeedsLeeds LS29JTUK

Cement clinker production in Egypt till 2013 relied mainly on fossil fuel as a primary energy ***,with multiple fossil fuel shortages,the utilization of biomass wastes was initiated by multiple cement *** the current work,and to present an industrial-scale biomass and coal co-combustion study,the utilization of multiple biomass fuels to substitute a portion of bituminous coal was studied in an Egyptian clinker production *** of biomass fuels were used to reduce the consumption of bituminous coal and to investigate the diminishing of the environmental impact of the clinker production *** current study was conducted during 8 days of the stable clinker production process by replacing 14%of bituminous coal with biomass mixtures while monitoring the major process control parameters and resulting *** results were compared to the nation’s regulations.A conclusion can be made that using biomass mixtures as alternative fuels minimized the dependency on coal as the main fuel and reduced the CO_(2)burden of the cement produc-tion *** addition,NO_(x)and SO_(2)emissions were declined while CO emissions were increased by utilizing biomass mixtures as alternative fuels;all emissions,however,were below the allowable limits stated by the Egyptian environmental ***,the heavy elements,dioxins,and furans were not changed significantly compared to those produced using coal only.

关键词： Refuse derived fuel Biomass Co-Combustion Clinker

Efect of early feeding practices and eating behaviors on body composition in primary school children

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World Journal of Pediatrics 2022年第9期18卷 613-623页

作者： Omneya Magdy Omar mohamed Naguib Massoud Afaf Gaber Ibrahim Nada Atef khalaf Department of Pediatrics Faculty of MedicineAlexandria UniversityAlexandria 21321Egypt Department of Community Medicine and Public Health Faculty of MedicineAlexandria UniversityAlexandriaEgypt

Background Understanding children’s feeding practices and eating behaviors is important to determine etiology of childhood *** study aimed to explore the relationship between early feeding practices,eating behavior and body composition among primary school *** The data were collected from 403 primary school *** were administered structured questionnaire,including sociodemographic characteristics,early feeding practices and Child’s Eating Behavior *** and blood pressure(BP)measurements were *** Children with obesity and overweight showed higher food approach subscales and lower food avoidance subscales compared to a healthy and underweight *** who were exclusively or predominantly breast fed during the frst 6 months had the lowest scores for the food approach subscales,food responsiveness(FR)and emotional overeating(EOE)and had the highest scores for the food avoidance subscales,satiety responsiveness(SR)and emotional under eating(EUE).Children who were introduced solid food after 6 months showed lower scores for FR,enjoyment of food and EOE but scored highest for SR,slowness in eating(SE)and *** anthropometric measurements were positively correlated with all food approach subscales and negatively with SE,SR and food *** food approach subscales were positively correlated with BP *** food avoidance subscales were negatively correlated with both BP percentiles,except for EUE,which was negatively correlated with diastolic BP percentile ***,SR,SE and FR were predictors for child body mass *** Early feeding practices and eating behavior are considered as prevention approaches for obesity.

关键词： Blood pressure Child eating behaviors Childhood obesity Feeding practices Waist circumference

Isotherm and kinetic studies on the adsorption of humic acid molecular size fractions onto clay minerals

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Acta Geochimica 2019年第6期38卷 863-871页

作者： mohamed E.A.El-Sayed Moustafa M.R.khalaf James A.Rice Department of Chemistry and Biochemistry South Dakota State UniversityBrookingsSD 57007USA Soils Waterand Environmental Research InstituteAgriculture Research CenterEl-GizaEgypt Chemistry Department Faculty of ScienceMinia UniversityEl-Minia 61519Egypt

Humic acid(HA)can adsorb onto mineral surfaces,modifying the physicochemical properties of the ***,understanding the sorption behavior of HA onto mineral surfaces is of particular interest,since the fate and transport of many organic and inorganic contaminants are highly correlated to HA adsorbed onto clay *** to the extreme heterogeneity of HA,the extracted IHSS Leonardite humic acid(LHA)used in this work was fractionated using an ultrafiltration technique(UF)into different molecular size fractions(Fr1,>0.2μm;Fr2,0.2 pm-300,000 daltons;Fr3,300,000-50,000 daltons;Fr4,50,000-10,000 daltons;Fr5,10,000-1000 daltons).Equilibrium and the kinetics of LHA and fraction adsorption onto kaolinite and montmorillonite were *** results demonstrated that the maximum adsorption capacity of LHA,Frl,Fr2,Fr3,Fr4,and Fr5 was 5.99,13.69,10.29,7.02,5.9&and 5.09 on kaolinite while it was 8.29,22.62,13.17,8.91,8.62,and 5.69 on montmorillonite,*** adsorption equilibrium data showed that the adsorption behavior of LHA and its fractions could be described more practically by the Langmuir model than the Freundlich *** rate of humic acid fraction adsorption onto clays increased with decreasing molecular size fraction and increasing carboxylic group ***-first-and second-order models were used to assess the kinetic data and the rate *** results explained that LHA and its fractions adsorption on clay minerals conformed more to pseudosecondo rder.

关键词： Kaolinite Montmorillonite Leonardite humic acid Humic acid fractions Kinetics Equilibrium

Variability of Wintertime Surface Air Temperature over the Kingdom of Saudi Arabia

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Atmospheric and Climate Sciences 2012年第3期2卷 307-321页

作者： Hosny mohamed Hasanean Abdel Rahman khalaf AL-khalaf Department of Meteorology Faculty of Meteorology Environment and Arid Land Agriculture King Abdulaziz University Jeddah Saudi Arabia

Variability of wintertime surface air temperature (SAT) in the Kingdom of Saudi Arabia (KSA) is studied. The study is based on time series over thirty one years in length (1978-2008). For the analysis, we use the coefficient of variability (COV) Mann-Kendal statistical test, running mean and cumulative annual mean (CAM). The coefficient of variability (COV) for wintertime SAT decreases gradually from the north to the south of KSA. The higher values for COV occur in northern and northeastern KSA;there are due to the effect of the traveling Mediterranean depressions and their interaction with the inverted-V shape trough of the Sudan low. The relationship between COV and latitude is highly significant, while with longitude it is not significant. The Mann-Kendal statistical test illustrates that positive trends (warming) in wintertime SAT series occurs over the all stations, and that the trends are significant at middle and southern regions of KSA. Recent warming has only occurred during the last two decades at most stations. While cooling in the wintertime SAT appears for the short period of about 5 years, 1978-1983 and 1988-1992. These trends are consistence with trends in the global mean SAT. The results obtained from CAW lead to the conclusion that the thermic regime is modifying in the KSA. This dramatic enhancement, occurred at the beginning of the year 1993, is reflected in net modification in the SAT time series. The analysis of the SAT also shows a significant warming trend after the year 1997 with a rate of 0.03?C/year.

关键词： Winter Temperature Saudi Arabia Coefficient of Variability Trends Cumulative Annual Mean

Subrectal and Subcutaneous Wound Infiltration with Bupivacaine versus Pethidine for Post Cesarean Section Pain Relief: Randomized Controlled Trial

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Open Journal of Obstetrics and Gynecology 2018年第11期8卷 1071-1083页

作者： Waleed M. khalaf mohamed Elmandouh mohamed Ibrahim Sarah Safwat Department of Obstetrics and Gynecology Faculty of Medicine Ain Shams University Cairo Egypt

Background: Cesarean section (CS), one of the most common major operative procedures, performed all over the world. Incisional infiltration with local anesthetics is a simple, cheap and effective mean of providing good analgesia for surgical operations without any major side effects & allowing early patients’ mobilization & postoperative recovery, so the purpose of study is to compare between the effect of wound infiltration with bupivacaine versus pethidine for post cesarean section pain relief. Patients and Methods: A randomized controlled trial (RCT) was conducted in Ain Shams University Maternity hospital in the period from August 2016 and January 2017. 100 full term pregnant females randomized into two groups: Group A (50 patients) Bupivacaine group: Subcutaneous and subrectal infiltration with 10 ml 0.25% Bupivacaine (2.5 mg/ml) diluted in 10 ml normal saline before closure of the wound was done;Group B (50 patients) Pethidine group: Subcutaneous and subrectal infiltration with 1 ml pethidine (50 mg/ml) diluted in 19 ml normal saline before closure of the wound was done. All patients had cesarean section under spinal anesthesia. Study outcome measures post-operative pain scores using visual analogue scale, post-operative analgesia requirement time to first rescue analgesia, onset of mobilization, side effect of local anesthetic, wound infection (after one week). It was registered on clinical *** with ID: NCT03652116. Results: Visual analogue scale values differ significantly between pethidine group and that of bupivacaine at rest and on coughing at 4, 8, 12, 24 hours & analgesic consumption (P value st time request analgesia per minute comparing group A to group B (P value 0.001). There is no significant difference between bupivacaine and pethidine regarding time of ambulation, side effects or complications. Conclusion: Infiltration of the wound of cesarean section with pethidine gives effective analgesia for several hours as compared to Bupivacaine.

关键词： Analgesia Ambulation Wound Infiltration Pethidine Bupivacaine

Outcomes of endoscopic submucosal dissection in cirrhotic patients: First American cohort

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World Journal of Hepatology 2024年第5期16卷 784-790页

作者： Robert Luke Pecha Fares Ayoub Ankur Patel Abdullah Muftah Michael W Wright Mai A khalaf mohamed O Othman Department of Gastroenterology and Hepatology UC DavisSacramentoCA 95817United States Department of Gastroenterology and Hepatology Baylor College of MedicineHoustonTX 77030United States Internal Medicine Baylor College of MedicineHoustonTX 77030United States Department of Gastroenterology and Hepatology University of Texas Medical Branch at GalvestonGalvestonTX 77550United States Medical School Baylor College of MedicineHoustonTX 77030United States Department of Tropical Medicine Tanta UniversityTanta 31527Egypt

BACKGROUND Among patients with cirrhosis and pre-malignant or early malignant mucosal lesions,surgical intervention carries a much higher bleeding *** such lesions are discovered,endoscopic submucosal dissection(ESD)may offer curative therapy with lower risks than surgery and improved outcomes compared to traditional endoscopic *** To evaluate the outcomes of ESD in patients with *** Patients with cirrhosis undergoing ESD between July 2015 and August 2022 were retrospectively matched in 1:2 fashion to controls based on lesion location,size,and anticoagulation *** outcomes were compared between *** A total of 64 Lesions from 59 patients were included(16 cirrhosis,43 control).There were no differences in patient or lesion characteristics between *** bloc and curative resection was achieved in 84.21%,78.94%of the cirrhosis group and 88.89%,68.89%of controls,respectively,with no significant *** patients had significantly higher rates of intra-procedural coagulation grasper use for control of bleeding(47.37%vs 20%;P=0.02).There were otherwise no significant differences in adverse event *** the 29 patients with follow up,we found higher rates of recurrence in the cirrhosis group compared to controls(40%vs 5.26%;P=0.019),however this effect did not persist on multivariable analysis controlling for known *** ESD may be safe and effective in patients with *** procedure related outcomes were not significantly different between ***-procedural bleeding requiring use of the coagulation grasper use was expectedly higher in the cirrhosis group given the known effects of liver disease on hemostasis.

关键词： Endoscopic aubmucosal dissection Cirrhosis Advanced polypectomy Intraprocedural bleeding Colon cancer