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Acid-treated carbon nanotubes and their effects on mortar strength

Frontiers of Structural and Civil Engineering 2016年第2期10卷 180-188页

作者： M. ELKASHEF K. WAnG M.n. ABOU-zeid Civil Construction and Environmental Engineering Department Iowa State University Ames IA 50011-2151 USA Construction and Architectural Engineering Department The American University in Cairo Egypt

In the present study, multi-walled carbon nanotubes （MWCnTs） were treated in an acidic mixture solution, made with nitric and sulfuric acids in a ratio of 3：1 by volume. The durations of the treatment were 100 and 180 min. The defects of these treated MWCnTs were examined using Raman spectroscopy. The attachment of hydroxyl functional groups to the walls of the MWCnTs were verified using FTIR spectroscopy. The dispersion of CnTs with acid treatment is assessed using UV-Vis spectroscopy and Scanning Electron Microscopy （SEM）. The results indicate that the duration of the acid treatment has significant effect on both the degree of defects and functionality of the MWCnT. The compressive strength of mortar increased with the addition of the acid-treated MWCnTs; however, no appreciable difference was noted for the two treatment durations under this study.

关键词： carbon nanotubes concrete composites nanomaterials cement

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High surface area and mesoporous activated carbon from KOH-activated dragon fruit peels for methylene blue dye adsorption:Optimization and mechanism study

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Chinese Journal of Chemical Engineering 2021年第4期34卷 281-290页

作者： Ali H.Jawad Ahmed Saud Abdulhameed Lee D.Wilson Syed Shatir A.Syed-Hassan zeid a.alothm.n Mohammad Rizwan Khan Faculty of Applied Sciences Universiti Teknologi MARA40450 Shah AlamSelangorMalaysia Department of Medical Instrumentation Engineering Al-Mansour University CollegeBaghdadIraq Department of Chemistry University of SaskatchewanSaskatoonSaskatchewan S7N 5C9 Canada Faculty of Chemical Engineering Universiti Teknologi MARA40450 Shah AlamSelangorMalaysia Chemistry Department College of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia

In this study,an alternative precursor for production of activated carbon was introduced using dragon fruit(Hylocereus costaricensis)peel(DFP).Moreover,KOH was used as a chemical activator in the thermal carbonization process to convert DFP into activated carbon(DFPAC).In order to accomplish this research,several approaches were employed to examine the elemental composition,surface properties,amorphous and crystalline nature,essential active group,and surface morphology of the *** BrunauerEmmettTeller test demonstrated a mesoporous structure of the DFPAC has a high surface area of 756.3 m2g *** cationic dye Methylene Blue(MB)was used as a probe to assess the efficiency of DFPAC towards the removal of MB dye from aqueous *** effects of adsorption input factors(*** dose(A:0.040.12 g L 1),pH(B:310),and temperature(C:3050℃))were investigated and optimized using statistical analysis(*** design(BBD)).The adsorption kinetic model can be best categorized as the pseudofirst order(PFO).Whereas,the adsorption isotherm model can be best described by Langmuir model,with maximum adsorption capacity of DFPAC for MB dye was 195.2 mg g 1 at 50℃.The adsorption mechanism of MB by DFPAC surface was attributed to the electrostatic interaction,pp interaction,and ***,the results support the ability of DFP to be a promising precursor for production of highly porous activated carbon suitable for removal of cationic dyes(***).

关键词： Statistical modeling Activated carbon Dragon fruit peels Box-Behnken design Methylene blue dye Adsorption

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介孔载体嫁接的离子液体催化二氧化碳合成碳酸丙烯酯

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石油化工 2009年第12期38卷 1264-1269页

作者：张学兰 Abdullah S n Al-Arifi Taieb Aouak zeid Abdullah Al-Othman 魏伟孙予罕中国科学院山西煤炭化学研究所煤转化国家重点实验室山西太原030001 中国科学院研究生院北京100049 Chemistry Department King Saud UniversityRiyadh 11451Kingdom of Saudi Arabia

将离子液体1-丙基(三乙氧基硅基)-3-甲基咪唑的氢氧化物([Smim]OH)分别嫁接到介孔SiO_2、MCM-41和SBA-15分子筛上制备了非均相嫁接型离子液体,用傅里叶变换红外光谱、n_2吸附、元素分析和热重分析等技术对3种非均相嫁接型离子液体进行... 详细信息

将离子液体1-丙基(三乙氧基硅基)-3-甲基咪唑的氢氧化物([Smim]OH)分别嫁接到介孔SiO_2、MCM-41和SBA-15分子筛上制备了非均相嫁接型离子液体,用傅里叶变换红外光谱、n_2吸附、元素分析和热重分析等技术对3种非均相嫁接型离子液体进行了表征。在无溶剂、温和的条件下,以非均相嫁接型离子液体为催化剂,研究了环氧丙烷(PO)与CO_2环加成合成碳酸丙烯酯的反应。实验结果表明,3种非均相嫁接型离子液体均具有较好的催化性能,[Smim]OH/SiO_2的催化性能最好;在[Smim]OH/SiO_2 1.260 mmol、PO 70 mmol、CO_22 MPa、120℃、8 h的优化反应条件下,PO的转化率可达99.5%;[Smim]OH/SiO_2重复使用4次后仍能保持较高的催化性能。

关键词：介孔载体离子液体催化剂二氧化碳环氧丙烷碳酸丙烯酯

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Trends and outcomes of pancreaticoduodenectomy for periampullary tumors: A 25-year single-center study of 1000 consecutive cases

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World Journal of Gastroenterology 2017年第38期23卷 7025-7036页

作者： ayman el nakeeb waleed askar ehab atef ehab el hanafy ahmad m sultan tarek salah ahmed shehta mohamed el sorogy emad hamdy mohamed el hemly ahmed a el-geidi tharwat kandil mohamed el shobari talaat abd allah amgad fouad mostafa abu zeid ahmed abu el eneen nabil gad el-hak gamal el ebidy omar fathy ahmed sultan mohamed abdel wahab gastroenterology surgical center mansoura university

AIM To evaluate the evolution, trends in surgical approaches a n d r e c o n s t r u c t i o n t e c h n i q u e s, a n d i m p o r t a n t lessons learned from performing 1000 consecutive pancreaticoduodenectomies(PDs) for periampullary *** This is a retrospective review of the data of all patients who underwent PD for periampullary tumor during the period from January 1993 to April 2017. The data were categorized into three periods, including early period(1993-2002), middle period(2003-2012), and late period(2013-2017).RESULTS The frequency showed PD was increasingly performed after the year 2000. With time, elderly, cirrhotic and obese patients, as well as patients with uncinate process carcinoma and borderline tumor were increasingly selected for PD. The median operative time and postoperative hospital stay decreased significantly over the periods. Hospital mortality declined significantly, from 6.6% to 3.1%. Postoperative complications significantly decreased, from 40% to 27.9%. There was significant decrease in postoperative pancreatic fistula in the second 10 years, from 15% to 12.7%. There was a significant improvement in median survival and overall survival among the *** Surgical results of PD significantly improved, with mortality rate nearly reaching 3%. Pancreatic reconstruction following PD is still debatable. The survival rate was also improved but the rate of recurrence is still high, at 36.9%.

关键词： Pancreaticoduodenectomy Pancreaticogastrostomy Pancreaticojejunostomy Postoperative pancreatic fistula Periampullary tumor

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