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Journal of Environmental Sciences 2012年第7期24卷 1240-1250页

作者： I. Ameur-Bouddabbous J. Kasperek A. Barbier f. Harel B. Hannoyer GPM-UMr 6634 CNrS. Ufr Science and Technology University of Rouen BP 12 76801 Saint Etienne du Rouvray Cedex France LCAE Chemistry Department Science Faculty of Tunis Campus Universitaire 2092 El Manar Tunis Tunisie DIrNO Rue de Verdun 76160 Darnetal France

With regard to automotive traffic, a tunnel-type semi enclosed atmosphere is characterized by a higher concentration of gaseous pollutants than on urban traffic roads and highlights the gaseous effluent species having an impact on material degradation. Therefore, a transverse approach between air quality and its consequences upon the longevity of materials is necessary, implying better knowledge of tunnel atmosphere and a better understanding of material degradation inside a tunnel for operating administration. Gaseous pollutant measurements carried out in a road tunnel in rouen （Normandy） give the real world traffic concentrations of experimental exposure conditions. The sampling campaigns, achieved in summer and winter include SO2, NO2, BTEX and aldehyde analyses. Effluent profiles in the upward and downward tubes have been established. The current work shows that SO2, NO〉 formaldehyde, acetaldehyde, propanal and butanal must be considered in the degradation process of materials in a stuffy environment. As regards NO,, its concentration depends on the modification of the automotive fleet. The total aldehyde concentrations indicate no particular trend between the two bores. formaldehyde, acetaldehyde, propanal, butanal and acrolein species are the most abundant species emitted by vehicles and represent 90% to 95% of the total aldehyde emissions.

关键词： SO2 tunnel study aldehydes NO2 BTEX atmospheric corrosion

Sintered fe-0.8%C-1.0%Si-0.4%Cu P/M Steel Preform Behaviour During Cold Upsetting

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Journal of Iron and Steel research International 2008年第5期15卷 81-87页

作者： A rajeshkannan K S Pandey S Shanmugam r Narayanasamy Thiagarajar College of Engineering ThiruparankundramMadurai 625015Tamil NaduIndia Maulana Azad National Institute of Technology Bhopal 462007Madhya PradeshIndia Department of Mechanical Engineering National Institute of TechnologyTiruchirappalli 620015Tamil NaduIndia Department of Production Engineering National Institute of TechnologyTiruchirappalli 620015Tamil NaduIndia

Cold upsetting experiments were carried out on sintered fe 0.8%C1.0%Si-0. 4%Cu steel preforms in order to evaluate their deformation characteristics. Powder preforms of 86 % of theoretical density, with two different ratios of height to diameter, were prepared using a suitable die set assembly on a 1.0 MN capacity hydraulic testing machine. Sintering was carried out in an electric muffle furnace for 1.5 h at 1 150 ℃. Each sintered compact was subjected to incremental loading of 0.04 MN under dry friction condition till a crack appeared at the free surfaces. The experimental results were critically analysed, the stress as a function of strain and densification was obtained, then the work hardening behaviour was analyzed. It has been found that in the process of enhancing densification, strength and strain hardening is also induced during upsetting, but the work hardening behaviour is not homogenously enhanced against strain and densification.

关键词： cold upsetting stress height strain densification work hardening behaviour

Biomaterials for refractive correction:corneal onlays and inlays

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Science China Chemistry 2014年第4期57卷 501-509页

作者： WU Jian fUNDErBUrGH James L WAGNEr William r McGowan Institute for regenerative Medicine University of Pittsburgh Department of Surgery University of Pittsburgh School of Medicine Department of Ophthalmology University of Pittsburgh School of Medicine Department of Bioengineering University of Pittsburgh

Corneal inlays and onlays represent a means of providing patients with permanent refractive error correction. As an alternative to conventional spectacles and contact lens, these techniques are less invasive compared with laser-based refractive surgery and are reversible. In this review, we provide a brief overview of the anatomic microstructure of the human cornea, indicating the primary physiological function for each component. Next, the wide range of biomaterials used as corneal inlays and onlays are considered, from synthetic polymers to biological components derived from the extracellular matrix. The limitations and challenges associated with the most common materials are discussed as is the need to improve their properties to achieve long-term, complication-free intraocular implantation. finally, the prospect of applying tissue engineering strategies is noted for its potential to generate autologous corneal tissue that could be implanted as the optimal inlay or onlay materials.

关键词： refractive error onlays inlays synthetic polymer biological extracellular matrix refractive surgery

Computerised Gate firing Control for 17-Level MLI using Staircase PWM

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Computer Systems Science & Engineering 2023年第1期44卷 813-832页

作者： M.Geetha r.Vijayabhasker Suresh Seetharaman Department of Electronics and Communications Engineering Kalaignar Karunanidhi Institute of TechnologyCoimbatoreTamilnadu641402India Department of Electrical and Electronics Engineering Anna UniversityRegional Centre CoimbatoreTamilnadu641046India

A basic 7-level MLI topology is developed and the same is extended to the 9-level then further increased to *** developed structure minimizes the component’s count and size to draw out the system *** the various advantages of MLIs,efficiency and reliability play a major role since the usage of components is higher for getting a low Total Harmonics Distortion(THD)*** becomes a major challenge incorporated in boosting the efficiency without affecting the THD *** parametric observations are done and realized for the designed 9-level and 17-level MLI,being the Total Standing Voltage(TSV),efficiency,cost function per level count,and power *** respective parameters are compared with several existing and modern circuits and found to be effective in their performance.A novel single-phase 17-level asymmetrical Multi-Level Inverter(MLI)topology is developed to reduce the number of overall *** developed topology generates 17-levels by using unequal DC *** developed MLI is proved under various tests con-ducted experimentally for the various loads like resistive,inductive,and combinational loads.A detailed comparison is done on several factors and represented graphically ***,the proposed design provides a less TSV value is 6 V_(dc),efficiency is 94.21%and cost factor per level Cf/L value for both values ofαis 2.01 and 2.05 and devices count with a low THD value 41.4%with respectively.

关键词： Inverters 9-level and 17-level MLI switches count load current voltages round-robin staircase PWM

Natural convection effects on TNT solidification inside a shaped charge mold

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Defence Technology（防务技术） 2022年第9期18卷 1653-1661页

作者： Cigdem Susantez Aldelio B.Caldeira Bruna r.Loiola Trakya University Engineering FacultyMechanical Engineering DepartmentEdirne22030Turkey Management and Technological Innovation Agency Brazilian ArmyRio de Janeiro23020-470Brazil Military Institute of Engineering Mechanical Engineering DepartmentRio de Janeiro22290-270Brazil

High Explosive Anti-tank(HEAT) warheads and ammunitions are frequently produced by explosive casting inside an axis-symmetric mold with an inverted conical geometry in the basis. In order to prevent manufacturing defects, the solidification process must be controlled. In this study, a dimensionless solidification model has been proposed to investigate the heat transfer considering the natural convection inside the liquid explosive and the numerical simulations were performed by using COMSOL Multiphysics and Modeling Software, employing trinitrotoluene(TNT) thermophysical properties. The effect of three different boundary conditions on the top of the mold have been evaluated: convection, adiabatic and isothermal. It has been observed that solidification process was faster for convection case and slower for isothermal case, while an intermediary total solidification time value was found for adiabatic ***, liquid explosive was completely surrounded by solid explosive during the solidification process for convection case and also for adiabatic case through the end of the process. Otherwise, it was not observed for isothermal case. The natural convection effects promoted a vortex inside the liquid explosive, accelerating the heat transfer process. It has been concluded that isothermal mold top boundary condition should be preferred to prevent manufacturing defects, avoiding high thermal stress.

关键词： Solidification Natural convection Explosive Dimensionless model Anti-tank ammunition

Application of Electron Energy Loss Spectroscopy and Energy filtering Transmission Electron Microscopy for Microchemical Studies in 2.25Cr-1Mo Steel

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Journal of Materials Science & Technology 2005年第3期21卷 361-366页

作者： P.Parameswaran Ilse Papst f.Hofer W.Grogger V.S.raghunathan Materials Characterisation Group Research Institute for Electron MicroscopyResearch Institute for Electron MicroscopyResearch Institute for Electron MicroscopyMaterials Characterisation Group Indira Gandhi Centre for Atomic ResearchKalpakkam 603 102IndiaTech.Univ.A-8010GrazAustriaTech.Univ.A-8010GrazAustriaTech.Univ.A-8010GrazAustriaIndira Gandhi Centre for Atomic ResearchKalpakkam 603 102India

Electron enregy loss spectroscopy (EELS) and energy filtering transmission electron microscopy (EfTEM) investigation on 2.25Cr-lMo steel was carried out to understand the nature of evolution of secondary carbides. The filtered images obtained from two different ageing treatments indicate that the steel evolves to a more stable carbide namely M23C6 in comparison to M2C. Microchemical information was generated from EELS spectra. Suitable choice for estimating the microchemical state was discussed. To evaluate the behaviour of ageing an elemental ratio of fe to Cr is employed.

关键词： ferritic steels 2.25Cr-lMo steel EfTEM EELS Ageing

Protein photocrosslinking reveals dimer of dimers formation on Marr protein in Escherichia coli

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Science China Chemistry 2012年第1期55卷 106-111页

作者： CHEN Xing HAO ZiYang CHEN Peng r. Beijing National Laboratory for Molecular Sciences(BNLMS) Department of Chemical BiologyCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

The multiple antibiotic resistance regulatory protein(Marr) binds to two promoter sites on the marO operator in Escherichia *** study showed that more than one Marr dimer proteins bound to either of its two promoter sites(Site I and Site II),suggesting that Marr might form higher complexes than homodimers when bound to DNA inside *** *** further verify this hypothesis,we site-specifically incorporated a photocrosslinking probe at the interface between two Marr dimer *** in living *** cells revealed a covalent linkage between the two interdimer subunits of Marr,suggesting that Marr forms dimer of dimers in vivo.

关键词： Marr protein antibiotic resistance protein photocrosslinking DNA binding site dimerization

Geo-vegetation Mapping and Soil Geochemical Characteristics of the Indikolapelessa Serpentinite Outcrop,Southern Sri Lanka

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Journal of Earth Science 2014年第1期25卷 152-168页

作者： Tilak Hewawasam G W A r fernando Danushka Priyashantha Department of Natural resources Sabaragamuwa University of Sri Lanka Department of Geography University of Peradeniya Department of Physics Open University of Sri Lanka

The serpentinite blocks of Indikolapelessa, located along an identified litho-tectonic boundary between the Highland Complex （HC） and the Vijayan Complex （VC） of Sri Lanka, have undergone extensive lateralization with metal enrichment. Characteristic serpentinite vegetation with some endemic species was recognized in the soils and supergene deposits develop on serpentinite lithology. This type of geological and ecological relationship forms vegetation covers on serpentinite lithologies which are sharply demarcated from the surrounding metamorphic terrains. The aforesaid ＂geo-ecological phenomenon＂ can be used as a tool for geo-vegetation mapping in ultramafic terrains to trace the geological boundaries in landscapes where rock outcrops are virtually absent. We success- fully applied the concept of geo-vegetation mapping in order to demarcate the boundary of underlain serpentinite rocks from surrounding non-serpentinite metamorphic rocks （e.g. granitic gneiss）. The hypothesis was supported by the geochemical variations of soils/supergene deposits found at serpen- tinite and non-serpentinite sites, especially immobile elements and some trace elements. Based on whole rock chemistry and soil chemical data obtained, we suggest that the Indikolapelessa serpentinite outcrop, together with the other four serpentinite outcrops, is more likely to represent the Mg-rich mantle fragments at the time of overthrusting of the two crustal blocks of HC and VC during the Pan- African event.

关键词： serpentinite serpentinite soil geochemistry geo-vegetation ultramafic rock Sri Lanka.

role of Disinfection in food Industry

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食品科学 2006年第11期27卷 159-163页

作者： G Sansebastiano r Zoni r Zanelli L Bigliardi Department of Public Health Section of Hygiene University of ParmaItaly

At present microbiological risk are still the most frequent in the food industry and the disinfection is one of the procedures that can be carried out in the general prevention of foodborne infectious diseases. In the industrial process of food transformation the cleaning and disinfection procedures of surfaces and machinery have to be considered an integrate system with food production,a technological aspect that surely affects the finished product quality and safety. first of all to carry out properly these operations it is necessary that the factory and the equipment have been designed and constructed with high standard of hygiene to reduce the risk of contamination and to facilitate the sanitation. The procedures involve several stages which generally include pre-washing with water,cleaning,real disinfection,and a final rinsing with water. In order to assure a right disinfections of surfaces areas and of processing equipment the choice of disinfectant takes on particular importance. Some of the most widely used disinfectants include the hypochlorous acid,the chlorine dioxide and the peroxides like peracetic acid; the latter is widely used in soft drink and mineral water industries. The efficiency of these chemical agents depends on various factors as pH,temperature and the presence of organic substances with which the disinfectants can react to give by-products which can reduce the activity and can present toxicity. The use of hypochlorite may led to the formation of carcinogenic substance such as trialomethanes (THM) while the use of chlorine dioxide may lead to the formation of chlorites and chlorates. The peracetic acid is a good alternative compounds and it doesn’t lead to the formation of carcinogenic by-products. In our researches we evaluated the effectiveness of peracetic acid to inactivate some resistant micro-organism like hepatitis A virus; our results show that in practical application in CIP (cleaning in place) it’s necessary to use concentration of

关键词： food industry disinfection peracetic acid HAV

Modeling flow in naturally fractured reservoirs： effect of fracture aperture distribution on dominant sub-network for flow

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Petroleum Science 2017年第1期14卷 138-154页

作者： J. Gong W. r. rossen Department of Geoscience and Engineering Delft University of Technology 2628 CN Delft The Netherlands

fracture network connectivity and aperture （or conductivity） distribution are two crucial features controlling flow behavior of naturally fractured reservoirs. The effect of connectivity on flow properties is well documented. In this paper, however, we focus here on the influence of fracture aperture distribution. We model a two dimensional fractured reservoir in which the matrix is impermeable and the fractures are well connected. The fractures obey a power-law length distribution, as observed in natural fracture networks. for the aperture distribution, since the information from subsurface fracture networks is limited, we test a number of cases： log-normal distributions （from narrow to broad）, power-law distributions （from narrow to broad）, and one case where the aperture is pro- portional to the fracture length. We find that even a well- connected fracture network can behave like a much sparser network when the aperture distribution is broad enough （c~ 〈 2 for power-law aperture distributions and σ ≥ 0.4 for log-normal aperture distributions）. Specifically, most fractures can be eliminated leaving the remaining dominant sub-network with 90% of the permeability of the original fracture network. We determine how broad the aperture distribution must be to approach this behavior and the dependence of the dominant sub-network on the parameters of the aperture distribution. We also explore whether one can identify the dominant sub-network without doing flow calculations.

关键词： Naturally fractured reservoir Non-uniformflow Effective permeability Percolation Waterflood