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computational fluid dynamics applied to high temperature hydrogen separation membranes

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Frontiers of chemical Science and Engineering 2012年第1期6卷 3-12页

作者： Guozhao JI Guoxiong WANG Kamel HOOMAN suresh BHATIA Joao c. DINIZ da cOSTA School of chemical Engineering the University of Queensland Brisbane 4072 Australia School of Mechanical and Mining Engineering the University of Queensland Brisbane 4072 Australia

This work reviews the development of computational fluid dynamics （cFD） modeling for hydrogen separation, with a focus on high temperature membranes to address industrial requirements in terms of membrane systems as contactors, or in membrane reactor arrange- ments. cFD modeling of membrane,.s attracts interesting challenges as the membrane provides a discontinuity of flow, and therefore cannot be solved by the Navier-Stokes equations. To address this problem, tile concept of source has been introduced to understand gas flows on both sides or domains （feed and permeate） of the membrane. This is an important solution, as the gas flow and concentrations in the permeate domain are intrinsically affected by the gas flow and concentrations in the feed domain and vice-versa. In turn, the source term will depend on the membrane used, as different membrane materials comply with different transport mechanisms, in addition to varying gas selectiv- ity and fluxes. This work also addresses concentration polarization, a common effect in membrane systems, though its significance is dependent upon the performance of the membrane coupled with the operating conditions. Finally, cFD modeling is shifting from simplified single gas simulation to industrial gas mixtures, when the mathematical treatment becomes more complex.

关键词： membrane gas separat:ion computationalfluid dynamics concentration polarization hydrogen

Seminal characteristics and sexual behavior in men of different age groups： is there an aging effect？

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Asian Journal of Andrology 2006年第A3期8卷 337-341页

作者： Panayiotis M. Zavos Khalied Kaskar Juan R. correa suresh c. Sikka Andrology Institute of America Lexington Kentucky 40523 USA centre de Fertilidad del caribe Rio Piedras Puerto Rico 00923 USA Department of Urology Tulane University School of Medicine New Orleans Louisiana 70118 USA

Aim： To assess the seminal characteristics as well as the sexual behavior of men of various age groups to establish the presence of an aging effect on those characteristics. Methods： Semen samples were collected from men （n = 792） undergoing in vitro fertilization or intrauterine insemination in cases of female factor infertility only. Samples were collected using a seminal collection device at intercourse and evaluated manually according to World Health Organization （WHO） standards. Men were divided into four groups according to their ages：（i） 20-30, （ii） 31-40, （iii） 41-50 and （iv） 51-60 years, and their seminal characteristics and responses to a sexual behavior questionnaire were compared. Results： The data showed statistically significant differences in the seminal characteristics tested, most notably in the sperm concentration, motility, grade of motility, hypo-osmotic swelling and normal sperm morphology. Furthermore, the decline in normal sperm morphology with age was more pronounced when using strict criteria rather than WHO standards. There were also differences in total sperm count, total motile sperm and total functional sperm fraction （assessed by both WHO and strict criteria）. Significant differences were also observed in the sexual behavior patterns in older men in terms of the number of years they have been trying to conceive, sexual frequency and sexual satisfaction. conclusion： The data clearly illustrate an aging effect on semen characteristics and sexual behavior in men as they age. It is suggested that the aging effect be taken into consideration when proposing normal standard values for semen characteristics in routine semen analysis as outlined by WHO standards.

关键词： seminal parameters male aging effect fertility sexual behavior semen quality male factor infertility

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大麻槿治疗尿石症和胆石症的临床前评价

Digital chinese Medicine 2023年第2期6卷 189-197页

作者： Swathi suresh Ankul Singh S chitra Vellapandian Department of Pharmacology SRM College of PharmacySRM Institute of Science and TechnologyKattankulathurTamil Nadu 603209India

目的探究大麻槿叶对尿石症和胆石症的疗效。方法评价大麻槿叶水提物对硫脲嘧啶和胆固醇胆酸饮食诱导的BALB/c小鼠胆石症和乙二醇诱导的Wistar大鼠尿石症的治疗作用。选取3个剂量的水提物(40、80和160 mg/kg)对小鼠胆石症的药效进行评价... 详细信息

目的探究大麻槿叶对尿石症和胆石症的疗效。方法评价大麻槿叶水提物对硫脲嘧啶和胆固醇胆酸饮食诱导的BALB/c小鼠胆石症和乙二醇诱导的Wistar大鼠尿石症的治疗作用。选取3个剂量的水提物(40、80和160 mg/kg)对小鼠胆石症的药效进行评价;另外3个剂量的水提物(400、800和1600 mg/kg)对大鼠尿石症的药效进行评价。在胆石症模型中测定胆汁胆固醇、胆汁磷脂、胆汁酸等生化指标;在尿石症模型中测定24小时尿量及肌酐、尿酸、蛋白质、尿素、草酸钙结晶、红细胞和脓尿等尿参数。结果给予3个试验剂量的大麻槿叶水提物后,动物的胆道和泌尿系统参数差别均具有统计学意义(P<0.05)。结论大麻槿对高脂致石饮食导致的尿石症和胆石症具有明显疗效。

关键词：大麻槿胆石症尿石症红麻胆结石肾结石

Stability Indicating RP-UPLc Method for Quantification of Glycopyrrolate, Methylparaben and Propylparaben Assay in Liquid Oral Formulation

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American Journal of Analytical chemistry 2022年第12期13卷 538-552页

作者： Sreenivas Pippalla Arjuna Rao Nekkalapudi suresh Babu Jillellamudi Sikkim Professional University Gangtok India Asphar Research Labs Pvt. Ltd. Hyderabad India

Stability indicating RP-UPLc technique was developed for the simultaneous quantification of glycopyrrolate, methylparaben, and propylparaben in glycopyrrolate oral solution. The method was established by using gradient UPLc and a Waters Acquity UPLc BEH c18, 100 mm 2.1 mm, i.d 1.7 μm particle size column with a gradient program of mobile phase A and mobile phase B with a flow rate of 0.25 mL/minute, UV wavelength detection at 222 nm, column temperature of 40°c, injection volume of 2 μL, mobile phase A contains 0.05% trifluoro acetic acid in water and Acetonitrile (90:10) v/v and mobile phase-B contains 0.05% trifluoro acetic acid in water and Acetonitrile (10:90) v/v. The current research describes a single UPLc method for developing an assay method for Glycopyrrolate Oral solution that includes Glycopyrrolate (Active), Methylparaben (Preservative), and Propylparaben (Preservative). The assay method was validated in accordance with IcH guidelines. The retention times of glycopyrrolate, methyl paraben and propylparaben were 6.051 min, 3.458 min and 8.095 min, respectively. Linearity range of glycopyrrolate, methyl paraben and propylparaben were in the range of 4 - 32 μg per mL, 35 - 290 μg per mL and 4 - 32 μg per mL, respectively. Recovery of glycopyrrolate, methylparaben and propylparaben ranged from 100.1% to 98.9%, 100.2% - 100.8%, and 100.2% - 100.8%. Validation of analytical method demonstrated that the method is suitable, specific, linear, accurate, precise, rugged and stability indicating for estimating three components in the pharmaceutical dosage form.

关键词： Glycopyrrolate Oral Solution UPLc Assay Methylparaben Propylparaben

catalyst-and solvent-free,thermal generation of microporous polymer networks

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Science china chemistry 2017年第8期60卷 1103-1106页

作者： christian widling michael forster venkata m.suresh ullrich scherf bergische universitt wuppertal macromolecular chemistry group(buwmakro)and institute for polymer technologyD-42119 WuppertalGermany

Multifunctional iodoaryl monomers were used for the catalyst-and solvent-free generation of microporous polymer networks of high surface areas up to 732 m^2 g^(-1). The thermal conversion of the monomers relies on the homolytic cleavage of weak iodine–carbon bonds followed by a c–c coupling of the radicalic intermediates. By using tri-or tetrafunctional monomers and by tuning reaction temperature and time, the optimum reaction conditions allow the formation of the corresponding microporous networks in good yields of 71%–86%. The resulting networks exhibit notable high cO_2 and H_2 adsorption capacities of up to 8.89wt%(273 K, 1 bar) and up to 1.31 wt%(77 K, 1 bar), respectively.

关键词： microporous polymer networks thermal generation gas uptake

comparative evaluation of semen parameters in pre-and post-Hurricane Katrina human population

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Asian Journal of Andrology 2015年第4期17卷 676-680页

作者： caner Baran Wayne J Hellstrom suresh c Sikka Department of Urology Tulane University School of Medicine New Orleans LA 70112 USA.

A natural disaster leading to accumulation of environmental contaminants may have substantial effects on the male reproductive system. Our aim was to compare and assess semen parameters in a normospermic population residing in the Southern Louisiana, USA area pre- and post-Hurricane Katrina. We retrospectively evaluated semen analyses data （n = 3452） of 1855 patients who attended the Tulane University Andrology/Fertility clinic between 1999 and 2013. The study inclusion criteria were men whose semen analyses showed -〉 1.5 ml volume; _〉15 million ml1 sperm concentration; _〉39 million total sperm count; _〉40% motility; 〉30% morphology, with an abstinence interval of 2-7 days. After the inclusion criteria applied to the population, 367 normospermic patients were included in the study. Descriptive statistics and group-based analyses were performed to interpret the differences between the pre-Katrina （Group 1, 1999-2005） and the post-Katrina （Group 2, 2006-2013） populations. There were significant differences in motility, morphology, number of white blood cell, immature germ cell count, pH and presence of sperm agglutination, but surprisingly there were no significant differences in sperm count between the two populations. This long-term comparative analysis further documents that a major natural disaster with its accompanied environmental issues can influence certain semen oarameters （e.g.. motility and morphology） and, bv extension, fertility potential of the population of such areas.

关键词： environment Hurricane Katrina, New Orleans area normospermic infertile population retrospective semen analYSiS

海枣核cO_2活化和磷酸活化制备活性炭及其结构、吸附性能(英文)

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新型炭材料 2012年第5期27卷 344-351页

作者： K. suresh Kumar Reddy Ahmed Al Shoaibi c. Srinivasakannan chemical Engineering Department The Petroleum Institute P.O. Box 2533 Abu Dhabi UAE

由于具有很大的吸附容量,多孔炭材料是优良的吸附剂。笔者试图比较海枣核分别经cO2活化和磷酸活化所制活性炭的结构和吸附性能。活化过程和工艺条件对炭的物理化学性质影响较大,根据文献报道的结果选取了优化的工艺参数。基于氮气吸附... 详细信息

由于具有很大的吸附容量,多孔炭材料是优良的吸附剂。笔者试图比较海枣核分别经cO2活化和磷酸活化所制活性炭的结构和吸附性能。活化过程和工艺条件对炭的物理化学性质影响较大,根据文献报道的结果选取了优化的工艺参数。基于氮气吸附等温线、SEM、FT-IR等分析结果,评估了活性炭的结构特征,吸附性能则由亚甲蓝吸附值表示。cO2活化得到了微孔活性炭,产率为44%、BET比表面积是666 m2·g-1;磷酸活化得到了产率为14.8%的中孔活性炭,BET比表面积为725 m2·g-1。cO2活化活性炭的平均孔径是1.51 nm,磷酸活化活性炭的则为2.91 nm。活性炭的亚甲蓝吸附等温线分别用Langmuir等温线和Freundlich等温线进行了验证,在优化工艺条件下制备的cO2活化炭和磷酸活化炭的亚甲蓝w单分子吸附容量分别为110 mg·g-1和345 mg·g-1。然而,磷酸活化产生的亚甲蓝吸附值最高达455 mg·g-1。

关键词：活性炭物理活化化学活化 Langmuir等温线 Freundlich等温线

Distribution Pattern of Vascular Plant Species of Mountains in Nepal and their Fate Against Global Warming

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Journal of Mountain Science 2015年第6期12卷 1345-1354页

作者： suresh chandra SUBEDI Khem Raj BHATTARAI Ram Prasad cHAUUDHARY Earth and Environment Department Florida International University National Herbarium and Plant Laboratories Department of Plant Resources Ministry of Forest and Soil conservation Research center for Applied Science and Technology Tribhuvan University

This study aims to find the altitudinal distribution pattern of vascular plant species reported from high mountain of Nepal(Manang) along the whole Himalayan elevation gradient, and evaluate their fate against climate change. Data was gathered from multiple sources, field investigations, literatures, and herbarium specimens. Altogether, 303 vascular plant species were reported from Manang. We used a published data to calculate distribution range of each species by interpolating between its upper and lower elevation limits. The relationship between elevation and species richness is elucidated by generalized linear model. The consequence of global warming upon Manang's vascular plant species was estimated based on projected temperature change for next century and adiabatic lapse rate along the elevation gradient of the Himalayas. The vascular plant species richness has a unimodel relationship with elevation along the whole elevation gradient of Nepal as well as in three biogeographical regions of Nepal. Vascular plants of Manang are found distributed from low land Terai to high alpine regions of Nepal and their elevation distribution range varies from 200 to 4700 m. Out of 303 vascular plants of Manang, only seven species might be affected if temperature increase by 1.5°c, whereas at least 70 species will be affected with 5°c temperature increased. However, the majority of species(233 species) have wider distribution range(> 1000 m) and more than 5°c temperature tolerance range, thus they are likely to be less affected from global warming by the end of 21 st century.

关键词：垂直分布格局全球变暖维管植物尼泊尔维管束植物喜马拉雅山脉海拔梯度植物物种

characteristics of La-modified Ni-Al_2O_3 and Ni-SiO_2 catalysts for cO_x-free hydrogen production by catalytic decomposition of methane

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Journal of Energy chemistry 2013年第6期22卷 853-860页

作者： chatla Anjaneyulu Velisoju Vijay Kumar suresh K.Bhargava Akula Venugopal Inorganic & Physical chemistry Division CSIR-Indian Institute of Chemical Technology college of Science Engineering and Health Advanced Materials & Industrial Chemistry School of Applied Sciences RMIT University

Hydrotalcite precursors of La modified Ni-Al2O3 and Ni-SiO2 catalysts prepared by co-precipitation method and the catalytic activities were examined for the production of cOx-free H2 by cH4 decomposition. Physico-chemical characteristics of fresh, reduced and used catalysts were evaluated by XRD, TPR and O2 pulse chemisorptions, TEM and BET-SA techniques. XRD studies showed phases due to hydrotalcite-like precursors in oven dried form produced dispersed NiO species upon calcination in static air above 450 c. Raman spectra of deactivated samples revealed the presence of both ordered and disordered forms of carbon. Ni-La-Al2O3catalyst with a mole ratio of Ni : La : Al = 2 : 0.1 : 0.9 exhibited tremendously high longevity with a hydrogen production rate of 1300 molH2 mol 1 Ni. A direct relationship between Ni metal surface area and hydrogen yields was established.

关键词： cH4 decomposition Ni-La-Al hydrotalcite Ni metal surface area cOx-free H2