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Quaternary Ammonium-based Composite particles for Antibacterial Finishing of Cotton-based Textiles

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Journal of Materials Science & Technology 2014年第1期30卷 19-29页

作者： M.Messaoud E.Chadeau p.Chaudouёt N.Oulahal M.Langlet LMGp(Grenoble Institute of Technology-Minatec) LRGIA(Universit de Lyon Universit Lyon 1)

The antibacterial finishing of cotton-based fabrics has been achieved from quaternary ammonium-based composite particles. This functionalization is based on the simple dilution of a quaternary ammonium cation （QAC） hybrid alkoxide within a sol-gel derived crystalline suspension （CS） of TiO2 in liquid solution. This protocol yields the preparation of QAC-Ti02 （QT） composite sols by using a same CS over a long period of time, and enables an easy regeneration of derived QT sols after quite long aging periods. Composite sols can then be impregnated on various kinds of substrates, including textile fabrics. Fourier transform infrared spectroscopy studies, as well as optical and scanning electron microscopy observations, have been used to investigate chemical and morphological features arising from QT particles. Antibacterial tests have then been performed on so-finished textiles and are discussed in relation to chemical and morphological features. It is shown that this sol-gel route flexibly yields a similarly strong antibacterial activity on cotton-based fabrics against both Gram-negative and Gram-positive bacteria, Le. tested fabrics exhibit an antibacterial activity （a（~cording to the ISO 20743-2005 standard） ranging between 7.5 and 7.9 against both kinds of bacteria tested here. Finishing treatments also allow preserving the hand feeling and visual aspect of the textiles and promote a rather good attachment of impregnated particles on the surface of textile fibers.

关键词： Quaternary ammonium TiO2 Antibacterial efficiency Textile Sol-gel

DISCRETE AppROXIMATIONS FOR SINGULARLY pERTURBED BOUNDARY VALUE pROBLEMS WITH pARABOLIC LAYERS, III

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Journal of Computational Mathematics 1996年第2期14卷 273-290页

作者： p.A. Farrell(Department of Mathematics and Computer Science, Kent State University, USA)p.W. Hemker(CWI Center for Mathematics and Computer Science, Amsterdam, The Netherlands)G.I. Shishkin(IMM, Institute of Mathematics and Mechanics, Ural Branch of the Kent State University 美国 Center for Mathematics and Computer Science 荷兰 Institute of Mathematics and Mechanics 俄罗斯

In this series of three papers we study singularly perturbed (Sp) boundary vaue problems for equations of elliptic and parabolic troe. For small values of the perturbation parameter parabolic boundary and interior layers appear in these problems. If classical discretisation methods are used, the solution of the finite difference scheme and the approximation of the diffusive flux do not converge uniformly with respect to this parameter. Using the method of special, adapted grids,we can construct difference schemes that allow approkimation of the solution and the normalised diffusive flux uniformly with respect to the small *** also consider singularly perturbed boundary value problems for convection diffusion equations. Also for these problems we construct special finite difference schemes, the solution of which converges E-uniformly We study what problems appear, when classical schemes are used for the approximation of the spatial deriva tives. We compare the results with those obtained by the adapted approach. Results of numerical experiments are *** the three papers we first give an introduction on the general problem, and then we consider respectively (i) problems for Sp parabolic equations, for which the solution and the normalised diffusive fluxes are required; (ii) problems for Sp elliptic equations with boundary conditions of Dirichlet, Neumann and Robin type;(iii) problems for Sp parabolic eqllation with discontinuous boundaxy conditions

关键词： III DISCRETE AppROXIMATIONS FOR SINGULARLY pERTURBED BOUNDARY VALUE pROBLEMS WITH pARABOLIC LAYERS

Influence of cryogenic treatment on the wear characteristics of 100Cr6 bearing steel

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International Journal of Minerals,Metallurgy and Materials 2014年第1期21卷 46-51页

作者： R.Sri Siva D.Mohan Lal p.Kesavan Nair M.Arockia Jaswin Department of Mechanical Engineering College of Engineering GuindyAnna University Department of Metallurgical and Material Engineering Indian Institute of Technology Madras Department of Mechanical Engineering Aksheyaa College of Engineering

A series of reciprocating wear tests were performed on the deep cryogenically treated and conventionally heat-treated samples of 100Cr6 bearing steel to study the wear resistance. The worn surfaces as well as the wear debris were analyzed by scanning electron microscopy. The improvement in wear resistance of the deep cryogenically treated samples ranges from 49% to 52%. This significant improvement in wear resistance can be attributed to finer carbide precipitation in the tempered martensitie matrix and the transformation of retained aus- tenite into martensite. X-ray diffraction analysis shows that the volume fraction of retained austenite in the conventionally heat-treated samples is 14% and that of the deep cryogenically treated samples is only 3%.

关键词： bearing steel cryogenic treatment wear resistance carbides martensite

Synthesis and Characterization of Zinc Succinate, Zn(C4H4O4)

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Chemical Research in Chinese Universities 2001年第1期17卷 20-25页

作者： ZHENG Yue qing ** (Institute for Solid State Chemistry, Ningbo University, Ningbo 315211, p. R. China) 宁波大学浙江宁波 315211 Max-planck Institute fur Festkor per forschung 德国 D-70569

pETERS Karl and von SCHNERING Hans Georg (Max planck Institute für Festkrperforschung, D 70569 Stuttgart, Germany)Zn(C 4H 4O 4) prepared by dissolving 0.483 g (1.41 mol) of Zn 3(OH) 4CO 3·H 2O and 0.5 g (4.23 mol) of C 4H 6O 4 in 50 mL of H 2O followed by slow evaporation at room temperature crystallizes in the monoclinic space group C 2 with the cell parameters a =0.757 9(1) nm, b =0.597 6(1) nm , c =0.626 5(1) nm, β =108.45(1)°, V =0.269 17(7) nm 3, D x=2.239 \{g/cm 3\}, Z =2 and the final R(F o)=0.039 and wR(F o 2)=0.088 for 396 reflections [ F o 2≥2 σ(F o 2)]. In the crystal structure unit, each Zn is tetrahedrally coordinated by four O atoms from four (C 4H 4O 4) 2- anions, each of which, in turn, bridges four Zn atoms to build up a 3D \{\} 3 ∞[Zn(C 4H 4O 4) 4/4 ] network. The thermal analyses indicate that Zn(C 4H 4O 4) is stable below 420 ℃.

关键词： Synthesis Zinc succinate Crystal structure Thermal decomposition

Clinical features and radiological manifestations of COVID-19 disease

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World Journal of Radiology 2020年第11期12卷 247-260页

作者： pedro Landete Carlos Andres Quezada Loaiza Beatriz Aldave-Orzaiz Susana Hernandez Muniz Antonio Maldonado Enrique Zamora Allan Charles Sam Cerna Elia del Cerro raquel Cano Alonso Felipe Counago Department of pulmonology H.U.La PrincesaMadrid 28006Spain Department of pulmonology H.12 de OctubreMadrid 28041Spain Department of Radiologist H.U.La PrincesaMadrid 28006Spain Department of Radiation Oncology Hospital Universitario Quironsalud MadridMadrid 28223Spain Department of pulmonology Hospital MD Anderson Madrid.EspanaMadrid 28033Spain Department of Diagnostic Imaging Hospital Universitario Quiron MadridMadrid 28223Spain Department of Radiation Oncology Hospital La LuzUniversidad Europea de MadridMadrid 28028Spain

Coronavirus disease 2019(COVID-19)was discovered after unusual cases of severe pneumonia emerged in December 2019 in Wuhan province(China).Coronavirus is a family of single-stranded RNA *** acute respiratory syndrome coronavirus 2(SARS-CoV-2)is transmitted from person to *** asymptomatic individuals can transmit the virus,symptomatic patients are more *** incubation period ranges from 3-7 d and symptoms are mainly respiratory,including pneumonia or pulmonary embolism in severe *** serum levels of interleukins(IL)-2,IL-6,IL-7 indicate the presence of cytokine release syndrome,which is associated with disease *** disease has three main phases:Viral infection,pulmonary involvement,and *** date,no treatment has proved to be safe or *** X-ray and computed tomography(CT)are the primary imaging tests for diagnosis of SARS-CoV-2 pneumonia,follow-up,and detection of *** main radiological findings are ground-glass opacification and areas of *** long-term clinical course is unknown,although some patients may develop pulmonary *** emission tomography-computed tomography(pETCT)is useful to assess pulmonary involvement,to define the affected areas,and to assess treatment *** pathophysiology and clinical course of COVID-19 infection remain poorly ***,patterns detected on CT and pETCT may help to diagnose and guide *** this mini review,we analyze the clinical manifestations and radiological findings of COVID-19 infection.

关键词： COVID-19 Coronavirus Natural history Clinical features pathogenesis Radiology images

Enrichment of Resveratrol in Wine through a New Vinification procedure

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Journal of Life Sciences 2015年第7期9卷 327-333页

作者： Raul Francisco pastor Magdalena raquel Gargantini Marcelo Murgo Sebastian prieto Humberto Manzano Carla Aruani Claudia In6s Quini Maria-Isabel Covas Roberto H6ctor Iermoli Section polyphenols Wine and Health Fourth Chair in Internal Medicine Clinics Hospital University of Buenos Aires BuenosAires C1408FZB Argentina Department Special Analytical Standards National Wine Institute Mendoza M5500AAR Argentina Department Oenological and Sensory Studies National Wine Institute Mendoza M5500AAR Argentina NUpROAS Handesbolag Sicka Alle Nacka 13165 Sweden

Sulphur dioxide is used in the vinification process as an antimicrobial agent, but it is also considered as an important risk factor for liver diseases. Stilbenes have inhibitory effects on the growth of lactic acid bacteria strains isolated from wine. The authors investigated the viability of obtaining free-SO2 resveratrol-enriched red wines. Substitution of sulfite （7 g/100kg） for resveratrol （150 mg/L and 300 mg/L） in the vinification process did not change the basic physical and chemical properties of wine or its sensorial profile To the best of the authors＇ knowledge this is the first time that this type of vinification procedure is reported.

关键词： Vinification sulfur dioxide resveratrol wine enrichment.

phase transformation and crystal growth behavior of 8mol%(SmO1.5, GdO1.5, and YO1.5) stabilized ZrO2 powders

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International Journal of Minerals,Metallurgy and Materials 2017年第7期24卷 842-849页

作者： R.Mahendran S.p.Kumaresh Babu S.Natarajan S.Manivannan A.Vallimanalan Department of Metallurgical and Materials Engineering National Institute of Technology Tirchirappalli 620015 Tamil Nadu india

Nanocrystalline powders of ZrO_2–8mol%SmO1.5（8Sm SZ）, ZrO_2–8mol%GdO1.5（8Gd SZ）, and ZrO_2–8mol%YO1.5（8YSZ） were prepared by a simple reverse-coprecipitation technique. Differential thermal analysis/thermogravimetry（DTA/TG）, Fourier transform infrared spectroscopy（FTIR）, X-ray diffraction（XRD）, Raman spectroscopy, and high-resolution transmission electron microscopy（HRTEM） were used to study the phase transformation and crystal growth behavior. The DTA results showed that the ZrO_2 freeze-dried precipitates crystallized at 529, 465, and 467°C in the case of 8Sm SZ, 8Gd SZ, and 8YSZ, respectively. The XRD and Raman results confirmed the presence of tetragonal ZrO_2 when the dried precipitates were calcined in the temperature range from 600 to 1000°C for 2 h. The crystallite size increased with increasing calcination temperature. The activation energies were calculated as 12.39, 12.45, and 16.59 k J/mol for 8Sm SZ, 8Gd SZ, and 8YSZ respectively.

关键词： zirconia thermal analysis reverse coprecipitation activation energy

Kinetics of thermal decomposition of hydrated minerals associated with hematite ore in a fluidized bed reactor

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International Journal of Minerals,Metallurgy and Materials 2017年第3期24卷 229-239页

作者： p.C. Beuria S.K. Biswal B.K. Mishra G.G. Roy Institute of Minerals and Materials Technology Council of Scientific & Industrial Research Bhubaneswar-751013 India Indian Institute of Technology Kharagpur-721302 India

The kinetics of removal of loss on ignition(LOI) by thermal decomposition of hydrated minerals present in natural iron ores(i.e.,kaolinite,gibbsite,and goethite) was investigated in a laboratory-scale vertical fluidized bed reactor(FBR) using isothermal methods of kinetic *** in the FBR in batch processes were carried out at different temperatures(300 to 1200°C) and residence time(1 to 30 min) for four different iron ore samples with various LOIs(2.34wt% to 9.83wt%).The operating velocity was maintained in the range from 1.2 to 1.4 times the minimum fluidization velocity(Umf).We observed that,below a certain critical temperature,the FBR did not effectively reduce the LOI to a desired level even with increased residence *** results of this study indicate that the LOI level could be reduced by 90% within 1 min of residence time at 1100°*** kinetics for low-LOI samples(perature *** lower temperatures(300 to 700°C),the kinetics is characterized by a lower activation energy(diffusion-controlled physical moisture removal),followed by a higher activation energy(chemically controlled removal of LOI).In the case of high-LOI samples,three different kinetics mechanisms prevail at different temperature *** temperature up to 450°C,diffusion kinetics prevails(removal of physical moisture);at temperature from 450 to 650°C,chemical kinetics dominates during removal of matrix *** temperatures greater than 650°C,nucleation and growth begins to influence the rate of removal of LOI.

关键词： thermal decomposition fluidized beds kinetic analysis hydrated iron ore activation energy

Abnormal psychology : clinical perspectives on psychological disorders 4th ed. 4th ed.

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Abnormal psychology : clinical perspectives on psychological...