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cO_2 adsorption using TiO_2 composite polymeric membranes:A kinetic study

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Journal of Environmental Sciences 2015年第9期27卷 163-171页

作者： Sarah Hafeez X.Fan Arshad Hussain c.F.Martín School of chemical and Materials Engineering (ScME) National University of Sciences & Technology Institute for Materials and Processes School of Engineering University of Edinburgh University of Aberdeen School of Engineering Fraser Noble Building King's College

cO2is the main greenhouse gas which causes global climatic changes on larger scale. Many techniques have been utilised to capture cO2. Membrane gas separation is a fast growing cO2 capture technique, particularly gas separation by composite membranes. The separation of cO2 by a membrane is not just a process to physically sieve out of cO2 through the controlled membrane pore size. It mainly depends upon diffusion and solubility of gases, particularly for composite dense membranes. The blended components in composite membranes have a high capability to adsorb cO2. The adsorption kinetics of the gases may directly affect diffusion and solubility. In this study, we have investigated the adsorption behaviour of cO2 in pure and composite membranes to explore the complete understanding of diffusion and solubility of cO2 through membranes. Pure cellulose acetate（cA） and cellulose acetatetitania nanoparticle（cA-TiO2） composite membranes were fabricated and characterised using SEM and FTIR analysis. The results indicated that the blended cA-TiO2 membrane adsorbed more quantity of cO2 gas as compared to pure cA membrane. The high cO2 adsorption capacity may enhance the diffusion and solubility of cO2 in the cA-TiO2 composite membrane, which results in a better cO2 separation. The experimental data was modelled by Pseudo first-order, pseudo second order and intra particle diffusion *** to correlation factor R2, the Pseudo second order model was fitted well with experimental data. The intra particle diffusion model revealed that adsorption in dense membranes was not solely consisting of intra particle diffusion.

关键词： Global warming cellulose acetate Gas adsorption Pseudo order models cO2 Ti O2

Important parameters in plasma jets for the production of RONS in liquids for plasma medicine: A brief review

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Frontiers of chemical Science and Engineering 2019年第2期13卷 238-252页

作者： Anna khlyustova cédric Labay Zdenko Machala Maria-Pau Ginebra cristina canal Biomaterials Biomechanics and Tissue Engineering GroupDepartment of Materials Science and MetallurgyUniversitat Politecnica de CatalunyaBarcelona 08019Spain Research centre in Multiscale Science and Engineering Universitat Politecnica de CatalunyaBarcelona 08019Spain Faculty of Mathematics Physics and InformaticsComenius UniversityBratislava 84248Slovakia

Reactive oxygen and nitrogen species (RONS) are among the key factors in plasma medicine. They are generated by atmospheric plasmas in biological fluids, living tissues and in a variety of liquids. This ability of plasmas to create a delicate mix of RONS in liquids has been used to design remote or indirect treatments for oncological therapy by treating biological fluids by plasmas and putting them in contact with the tumour;Documented effects include selective cancer cell toxicity, even though the exact mechanisms involved are still under investigation. However, the "right" dose for suitable therapeutical activity is crucial and still under debate. The wide variety of plasma sources hampers comparisons. This review focuses on atmospheric pressure plasma jets as the most studied plasma devices in plasma medicine and compiles the conditions employed to generate RONS in relevant liquids and the concentration ranges obtained. The concentrations of H2O2, NO2^-, NO3^- and short-lived oxygen species are compared critically to provide a useful overview for the reader.

关键词： atmospheric plasma jets liquids ROS RNS plasma-dose

Seismic response of bridge pier on rigid caisson foundation in soil stratum

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Earthquake Engineering and Engineering Vibration 2008年第1期7卷 33-43页

作者： c. Tsigginos N. Gerolymos D. Assimaki G. Gazetas National Technical University of Athens Greece Civil Engineer civil Engineering National Technical University of Athens Greece Lecturer civil Engineering Georgia Institute of Technology Atlanta USA Assistant Professor civil Engineering National Technical University of Athens Greece Professor

An analytical method to study the seismic response of a bridge pier supported on a rigid caisson foundation embedded in a deep soil stratum underlain by a homogeneous half space is developed. The method reproduces the kinematic and inertial responses, using translational and rotational distributed Winkler springs and dashpots to simulate the soil-caisson interaction. closed-form solutions are given in the frequency domain for vertical harmonic S-wave excitation. comparison with results from finite element （FE） analysis and other available solutions demonstrates the reliability of the model. Results from parametric studies are given for the kinematic and inertial responses. The modification of the fundamental period and damping ratio of the bridge due to soil-structure interaction is graphically illustrated.

关键词： caisson embedded foundations kinematic response inertial response Winkler model effective period effective damping

Ambient noise during rough weather and cyclones in the shallow Bay of Bengal

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chinese Journal of Oceanology and Limnology 2014年第4期32卷 921-932页

作者： M. c. SANJANA G. LATHA A. THIRUNAVUkkARASU National Institute of Ocean Technology PallikaranaiChennai-600 100Tamil NaduIndia

This paper presents ambient noise analysis during rough weather, using time series measurements from an automated noise measurement system in the shallow southwest Bay of Bengal during October–November 2010. The period witnessed low-pressure events including depressions and cyclones, with JAL cyclone passing close to the measurement site. The time series noise level shows a shift in mid-October, after which deep depressions and cyclones formed, with an average increase of 5–10 dB in the lower band and 2–3 dB in the higher band of frequencies. Furthermore, correlation between noise level and wave height(data from wave rider buoy deployed at the site) for sea state scale 3 and above shows good correlation with an increase in noise level with increase in wave height, the effect being most pronounced at 0.5 kHz. The noise captured during JAL was analysed to identify the spectrum components due to convective precipitation and heavy wind/wave activity and shows anomalously high levels during the crossing of the cyclone. Rain noise spectra from the rain bands associated with the wall of the cyclone are reported. This has been correlated with radar refl ectivity measurements to ascertain the presence of rain, and discriminate between convective and stratiform types. Also, vertical directionality pattern of ambient noise during JAL showed clearly distinct surface contributions. On the whole, knowledge of ambient noise fields during high sea states and precipitation is useful in optimizing SONAR performance. The findings at the study site have been compared with measurements from other shallow water locations during rough weather.

关键词： ambient noise JAL cyclone shallow water

Simple shear extrusion versus equal channel angular pressing:A comparative study on the microstructure and mechanical properties of an Mg alloy

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Journal of Magnesium and Alloys 2023年第5期11卷 1769-1790页

作者： A.Rezaei R.Mahmudi c.cayron R.E.Logé School of Metallurgical and Materials Engineering College of EngineeringUniversity of TehranNorth Kargar StreetTehran 14395-515Iran Laboratory of Thermomechanical Metallurgy-PX Group chair Ecole Polytechnique Fédérale de Lausanne(EPFL)Neuchâtel CH-2002Switzerland

Two severe plastic deformation(SPD)techniques of simple shear extrusion(SSE)and equal channel angular pressing(EcAP)were employed to process an extruded Mg-6Gd-3Y-1.5Ag(wt%)alloy at 553 k for 1,2,4 and 6 *** microstructural evolutions were studied by electron back scattered diffraction(EBSD)analysis and transmission electron microscopy(TEM).The initial grain size of 7.5μm in the extruded alloy was reduced to about 1.3μm after 6 SPD *** dynamic recrystallization was suggested to be operative in both SSE and EcAP,with also a potential contribution of continuous dynamic recrystallization at the early stages of *** difference in the shear strain paths of the two SPD techniques caused different progression rate of dynamic recrystallization(DRX),so that the alloys processed by EcAP exhibited higher fractions of recrystallization and high angle grain boundaries(HAGBs).It was revealed that crystallographic texture was also significantly influenced by the difference in the strain paths of the two SPD methods,where dissimilar basal plane texture components were *** compression tests,performed along extrusion direction(ED),indicated that the compressive yield stress(cYS)and ultimate compressive strength(UcS)of the alloys after both SEE and EcAP augmented continuously by increasing the number of ***-processed alloys had lower values of cYS and UcS compared to their counterparts processed by *** difference in the mechanical responses was attributed to the different configurations of basal planes with respect to the loading direction(ED)of each SPD technique.

关键词： Mg-Gd-Y alloys Severe plastic deformation Simple shear extrusion Equal channel angular pressing Dynamic recrystallization Mechanical properties

Study of Transition from Laminar to Turbulent Boundary Layer on a Tilted Flat Plate Using Heat Transfer Measurements

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Journal of Thermal Science 2007年第2期16卷 186-191页

作者： E.Sanz c.Nicot R.Point F.Plaza Laboratoire de Mécanique des Fluides et Acoustique LMFA(ECL-UCB-INSA Lyon-CNRS)36Avenue Guy de Collongue69134 Ecully.France.

The boundary layer transition over a flat tilted plate has been studied by means of heat transfer measurements. A heat flux sensor has been developed, in order to measure the efficiency of convective heat transfer for various types of surfaces or flows. Its operation at constant temperature allows direct and fast measurements of heat flux. The present paper reports the development of the sensor and presents its application to the study of transition in a boundary layer depending on the angle of incidence of the external flow. An exponential relationship between critical Reynolds number and pressure gradient parameter has been found.

关键词： convective heat flux boundary layer transition pressure gradient.

Photo-induced Synthesis and characterization of Poly(methyl methacrylate) Grafted Sodium Salt of Partially carboxymethylated Guar Gum

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chinese Journal of Polymer Science 2014年第12期32卷 1690-1703页

作者： J.H.Trivedi M.D.Thaker H.c.Trivedi P.G. Department of chemistry Sardar Patel University

Photo-induced graft copolymerization of methyl methacrylate（MMA） onto sodium salt of partially carboxymethylated guar gum（Na-PcMGG, DS = 0.291） was carried out in an aqueous medium using ceric ammonium nitrate（cAN） as photoinitiator to synthesize a novel graft copolymer, Na-PcMGG-g-PMMA, which may find its potential application as a metal adsorbent. The influences of synthesis variables such as concentrations of photoinitiator（cAN）, nitric acid and monomer（MMA） as well as reaction time, temperature and amount of substrate on the grafting yields were studied and the reaction conditions for optimum photo-grafting were evaluated. At optimum concentration, the maximum values of the grafting yields achieved were G = 271.61% and GE = 63.89%. The experimental results were found to be in very good agreement with the proposed kinetic scheme. The photo-graft copolymerization of MMA onto Na-PcMGG（ DS = 0.291） was also carried out in the presence and absence of ultraviolet radiation for studying the efficiency of the photoinitiator. The influence of carboxymethyl groups introduced onto the guar gum molecules with regard to its behavior towards ultra-violet radiation induced grafting with MMA was also investigated. Photo-grafting process was confirmed and the products were characterized with the help of the spectroscopic（1H-NMR and FTIR） and SEM techniques.

关键词： Photo-induced grafting Methyl methacrylate Sodium salt of partially carboxymethylated guar gum Optimum reaction conditions characterization.

Overview of Fischer-Tropsch Synthesis in Slurry Reactors

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chinese Journal of chemical Engineering 2000年第3期8卷 255-266页

作者：丁百全李涛 A.A.c.M.Beenackers G.P.vanderLaan DepartmentofchemicalEngineering EastChinaUniversityofScienceandTechnologyShanghai200237China DepartmentofchemicalEngineering UniversityofGroningenNijenborgh49747AGGroningenTheNetherlands

A brief review of Fischer-Tropsch synthesis specially in slurry reactors is presented, covering reaction kinetics, activity and selectivity of catalysts, product distribution, effects of process parameters, mass transfer and solubility of gas. Some important aspects of further research are proposed for improving both theories and production.

关键词： Fischer-Tropsch synthesis slurry reactor kinetics catalyst mass transfer

Nitrogen mass balance in a constructed wetland treating piggery wastewater effluent

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Journal of Environmental Sciences 2014年第6期26卷 1260-1266页

作者： Soyoung Lee Marla c.Maniquiz-Redillas Jiyeon choi Lee-Hyung kim Water Environment Research Dept. National Institute of Environmental Research Hwangyeong-ro 42 Seo-gu Incheon 404-708 Korea Department of civil and Environmental Engineering Kongju National University 275 Budaedong Seobukgu Cheonan Chungnamdo 331-717Korea

The nitrogen changes and the nitrogen mass balance in a free water surface flow constructed wetland （cW） using the four-year monitoring data from 2008 to 2012 were estimated. The cW was composed of six cells in series that include the first settling basin （cell 1）, aeration pond （cell 2）, deep marsh （cell 3）, shallow marsh （cell 4）, deep marsh （cell 5） and final settling basin （cell 6）. Analysis revealed that the NH4＋-N concentration decreased because of ammonification which was then followed by nitrification. The NO4＋-N and NO4＋-N were also further reduced by means of microbial activities and plant uptake during photosynthesis. The average nitrogen concentration at the influent was 37,819 kg/year and approximately 45% of that amount exited the cW in the effluent. The denitrification amounted to 34% of the net nitrogen input, whereas the accretion of sediment was only 7%. The biomass uptake of plants was able to retain only 1% of total nitrogen load. In order to improve the nutrient removal by plant uptake, plant coverage in four cells （i.e., cells 1, 3, 4 and 5） could be increased.

关键词： constructed wetland livestock wastewater nitrogen mass balance plant uptake sediment