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Journal of Materials science & Technology 2008年第2期24卷 272-278页

作者： B.C.samanta T.Maity s.dalai A.K.Banthia Department of Chelnistrv and Chemical Technology Vidyasagar UniversityMidnapore-721102India Materials science Centre Indian Institute of TechnologyKharagpur-721302India

An investigation was carried out to modify the toughness of triethylene tetramine cured DGEBA （diglycidyl ether of bisphenol-A） resin using solid amine terminated poly （ethylene glycol） benzoate （ATPEGB） as modifier with and without red mud waste particles. The solid ATPEGB modifier synthesized from the acid catalyzed esterification reaction of poly （ethylene glycol）（PEG） and 4-amino benzoic acid was characterized by Fourier transform infrared spectroscopy （FT-IR） and ^1H-NMR （nuclear magnetic resonance） spectroscopies, viscosity measurements, and solubility parameter calculation. The unfilled and red mud waste filled modified epoxy networks were evaluated with impact, adhesive, tensile, flexural and thermal properties by differential scanning calorimetry （DsC）, thermogravimetric （TG） and dynamic mechanical analysis （DMA）. The effect of modifier concentration and red mud waste particles on toughening behavior was also investigated. The optimum properties were obtained at 12.5 phr （parts per hundred parts of resin） concentration of the modifier. The ATPEGB modified cured epoxy was thermally stable up to 315℃. The morphology on fracture surfaces of cured epoxy was also analyzed by scanning electron microscopy （sEM）.

关键词： Epoxy Toughness Adhesive Morphology

Relationship between the microstructure and properties of thermomechanically processed Fe-17Mn and Fe-17Mn-3Al steels

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International Journal of Minerals,Metallurgy and Materials 2019年第1期26卷 64-75页

作者： Renuprava dalai siddhartha Das Karabi Das Department of Metallurgical and Materials Engineering Indian Institute of Technology

Two austenitic Mn steels(Fe-17 Mn and Fe-17 Mn-3 Al(wt%, so as the follows)) were subjected to thermomechanical processing(TMP) consisting of forging followed by solutionization and hot rolling. The rolled samples were annealed at 650 and 800°C to relieve the internal stress and to induce recrystallization. The application of TMP and heat treatment to the Fe-17 Mn/Fe-17 Mn-3 Al steels refined the austenite grain size from 169 μm in the as-solutionized state to 9–13 μm, resulting in a substantial increase in hardness from HV 213 to HV 410 for the Fe-17 Mn steel and from HV 210 to HV 387 for the Fe-17 Mn-3 Al steel. The elastic modulus values, as evaluated by the nanoindentation technique, increased from(175 ± 11) to(220 ± 12) GPa and from(163 ± 15) to(205 ± 13) GPa for the Fe-17 Mn and Fe-17 Mn-3 Al steels, respectively. The impact energy of the thermomechanically processed austenitic Mn steels was lower than that of the steels in their as-solutionized state. The addition of Al to the Fe-17 Mn steel decreased the hardness and elastic modulus but increased the impact energy.

关键词： austenitic manganese steel(AMs) thermomechanical processing(TMP) microstructure property hardness elastic modulus

Mixing and segregation of binary mixtures of biomass and silica sand in a fluidized bed

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Particuology 2021年第5期19卷 58-73页

作者： Tolu Emiola-sadiq Jiachen Wang Lifeng Zhang Ajay dalai Department of Chemical and Biological Engineering University of Saskatchewan.SaskatoonSK S7N 5A9Canada

In this work,mixing and segregation of binary mixtures involving biomass materials in a fluidized bed was experimentally investigated.A frozen bed method was employed to investigate both axial and radial distribution of biomass particles in silica *** different biomass materials were studied:willow sawdust,pelletized soy and oat hull *** loading investigated ranged from 5% to 30% by *** extent of mixing for each of the biomass composition was investigated using Lacey’s mixing index which is based on the standard deviations of the sample at different axial positions in the *** radial composition was also investigated by means of digital imaging analysis using a high-resolution digital *** experiments revealed the differences in the extent of particle distribution for pelletized biomass materials vs non-densified materials as a result of differences in particle size,density and importantly,the particle shape of the materials *** results showed an increase in the extent of mixing as the fluidizing velocity increased for both pellet materials while the mixing index for sawdust decreased beyond a loading of 20%.With an increase in biomass loading,an increase in mixing index was found for the two pellet materials.A similar trend was observed for sawdust at the lower loading ***,the mixing index started to decrease at higher loading level beyond 20%.The results greatly contributed to the understanding of the hydrodynamics of binary and multicomponent mixtures involving biomass materials,especially pelletized materials in fluidized beds.

关键词： Mixing segregation Biomass Binary Fluidization Pellets

[bmim]OH： An efficient catalyst for the synthesis of mono and bis spirooxindole derivatives in ethanol at room temperature

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Chinese Chemical Letters 2016年第5期27卷 714-720页

作者： swapnil A. Padvi Yogesh A. Tayade Yogesh B. Wagh Dipak s. dalai school of Chemical sciences North Maharashtra University Jalgaon 425 001 MS India

A rapid and efficient, one pot synthesis of spirooxindole derivatives has been attempted by three- component reaction of isatin, malononitrile and carbonyl compound possessing a reactive c^-methylene group by using task specific ionic liquid, 1-butyl-3-methyl imidazolium hydroxide [bmim]OH as a catalyst. The important features of this methodology are straight forward route in short reaction time at room temperature and avoid any hazardous organic solvent, toxic catalyst, tedious purification step. Interestingly, this protocol is not only limited to mono-systems but also to the synthesis of newer bis- spirooxindole system. The separation of the product and reusability of the catalyst are easy with excellent yield. The [bmim]OH catalyst system could be reused up to five recycles without appreciable loss of activity.

关键词： Task specific ionic liquid [bmim]OH lsatin spiro compounds Green synthesis

strain and kinematic vorticity analysis:An indicator for sinistral transpressional strain-partitioning along the Lancangjiang shear zone,western Yunnan,China

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science China Earth sciences 2009年第5期52卷 602-618页

作者： Bo Zhang JinJiang Zhang dalai Zhong Lei Guo state Key Laboratory Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China The Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education Peking University Beijing 10

This work deals with the preliminary relationship between strain path and strain partitioning pattern in a sinistral transpressional zone, Lancangjiang shear zone, located to the southeast of Tibet. Various ductile ro... 详细信息

关键词： strain kinematic vorticity transpression strain partitioning Lancangjiang shear zone

Crustal deformation and tectonic levels of Nujiang Gorge since the Miocene

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science China Earth sciences 2018年第1期61卷 93-108页

作者： LIU ZhiCheng JI JianQing sA Xiao CHEN YaPeng ZHONG dalai China Earthquake Disaster Prevention Center Beijing 100029 China school of Earth and space sciences Peking University Beijing 100871 China Power China beijing Engineering Corporation Limited Beijing 100024 China Institution of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

Crustal deformation shows different patterns at different depths due to changes in the physical properties of *** levels can be defined based on the geometry and deformation mechanisms of crustal deformation patterns. Nujiang Gorge, with a high riverbed drop, great erosion depth, and strong deformation, has rock exposures at different tectonic levels and thus provides an ideal lab for deformation study. This paper takes the Nujiang Gorge from Chawalong to Fugong as the object to identify structural deformation patterns at different depths through field study and deformation analysis. At depth, the primary form of deformation is flow deformation, as shown on the outcrops at Maji. Ductile shear deformation can be found in many outcrops within the study region, e.g., the Gaoligong dextral shear zone and Puladi-songta sinistral shear zone that lie to the south and north of Maji, respectively. Further to the north of Puladi, the dominated deformation pattern is similar fold and dense sub-vertical foliation. In addition, brittle faults, as evidence of shallow deformation, can be seen overprinting on the deeper deformation features all over the region. Based on those observations, this paper identifies four tectonic levels from depth to the surface: flow deformation, ductile shear deformation, similar fold, and brittle fault deformation, all of which result from the NEE-sWW compressive stress field. Further evidence from studies on the region′s thermal evolution and regional tectonics suggests that the development of different tectonic levels is closely linked to the discrepant uplift or denudation since the Miocene(~21 Ma).

关键词： Tectonic level Nujiang Gorge Flow deformation Ductile shear deformation Thermal evolution

studies on the effects of moisture and ageing on charge de-trapping properties of oilimpregnated pressboard based on IRC measurement

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High Voltage 2019年第2期4卷 151-157页

作者： Nasirul Haque sovan dalai Biswendu Chatterjee sivaji Chakravorti Department of Electrical Engineering Jadavpur UniversityRaja S.C.Mullick RoadKolkataWest BengalIndia NIT Calicut CalicutKeralaIndia

The dielectric properties of oil-paper insulation degrade due to moisture ingression and *** degradation significantly impacts the space charge accumulation and charge trapping behaviour in the insulation,which are vital parameters for insulation health under the high-voltage direct current *** this work,an improved model based on the isothermal relaxation current(IRC)has been developed to study the charge trapping behaviour of an oil pressboard under the influence of moisture and *** conventional IRC model considers the total relaxation current because of charge de-trapping ***,in the case of a composite dielectric like oil pressboard,dipolar relaxation also affects the relaxation *** this work,a methodology has been proposed to investigate charge de-trapping behaviour of oil-pressboard insulation considering the dipole relaxation process from IRC *** this purpose,frequency domain spectroscopy measurements and IRC measurements have been performed on oil-impregnated pressboard specimens carefully prepared in the laboratory having different ageing conditions and moisture *** presented in this work depict that charge trapping parameters,*** trap depth and trapped charge distribution are highly affected both by ageing and *** was observed that ageing leads to the generation of deeper traps,while moisture mainly enhances the density of shallow traps.

关键词： moisture trapping charge

Oxidative Coupling of Methane over Lithium Doped (Mn+W)/siO_2 Catalysts

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Journal of Natural Gas Chemistry 2007年第2期16卷 121-129页

作者： A. Malekzadeh A. Khodadadi A. K. dalai M. Abedini school of Chemistry Damghan University of Basic SciencesDamghanIran College of Chemical Engineering University of TehranTehranIran Department of Chemical Engineering University of SaskatchewanResearch Annex105 Maintenance RoadSaskatoonSK S7N 5C5Canada College of Chemistry University of TehranTehranIran

Modification and performance of Li induced silica phase transition of （Mn＋W）/siO2 catalyst, under reaction conditions of oxidative coupling of methane （OCM）, have been investigated employing textural characterizations and redox studies. stability and precrystalline form of fresh Li induced silica phase transition catalyst depend on the Li loading. A catalyst, with high lithium loading, destabilizes on OCM stream. This destabilization is not due to Li evaporation at OCM reaction conditions, α-cristobalite is proposed to be an intermediate in the crystallization of amorphous silica into quartz in the Li-induced silica phase transition process. However, the type of crystalline structure was found to be unimportant with regard to the formation of a selective catalyst. Metal-metal interactions of Li-Mn, Li-W and Mn-W, which are affected during silica phase crystallization, are found to be critical parameters of the trimetallic catalyst and were studied by TPR. Role of lithium in Li doped （Mn＋W）/siO2 catalyst is described as a moderator of the Mn-W interaction by involving W in silica phase transition. These interactions help in the improvement of transition metal redox properties, especially that of Mn, in favor of OCM selectivity.

关键词： oxidative coupling of methane silica phase transition lithium intermetallic interaction redox properties

structural and Geochronological Evidence for Multiple Episodes of Tertiary Deformation along the Ailaoshan-Red River shear Zone, southeastern Asia, since the Paleocene

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Acta Geologica sinica(English Edition) 2006年第1期80卷 79-96页

作者： ZHANG Jinjiang ZHONG dalai sANG Haiqing ZHOU Yong The Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education China ~ School of Earth and Space Sciences Peking University Beijing 100871 Institute of Geology and Geophysics Chinese Academy of Sciences P. O. Box 9825 Beijing 100029

structural analyses show that the Ailaoshan-Red River shear zone （AsRRsZ） in Ailao Mountain is composed of three different deformational domains. These domains may represent three episodes of left-lateral slip experienced by the AsRRsZ. The first episode of such deformation occurred throughout the eastern high-grade belt of the AsRRsZ under a transtensional regime and produced L- type tectonites of amphibolite grade. The second episode of left-lateral slip formed high strain zones overprinting the high-grade belt. Its deformational mechanism is similar to simple shear and the deformed rocks are L-s mylonites of greenschist grade. The third episode of left-lateral slip took place chiefly in a western low-grade belt of the AsRRsZ. This deformation occurred in a transpressional regime, formed an overall structure pattern of a sinistral thrust system and produced phyllonites of low-greenschist grade. Geochronological data indicated that the three episodes of left-lateral slip happened before ～58-56 Ma, at least from ～27 Ma to 22 Ma and at ～13-12 Ma respectively. The first episode of slip in the AsRRsZ appeared to correspond to the initial collision of India and Asia at ～60 Ma. The second episode took place almost at the same time as the most intensive compression and uplift in Tibet. The latest event might represent a further eastward material flow in Tibet after ～16-13 Ma. Thus, the AsRRsZ of southeastern Asia probably experienced three main episodes of Tertiary left- lateral slip in the course of intracontinental convergence since the India-Asia collision.

关键词： Ailaoshan-Red River shear zone southeastern Asia geochronology deformation history,India-Asia collision

study of cyanide removal from contaminated water using zinc peroxide nanomaterial

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Journal of Environmental sciences 2017年第5期29卷 76-85页

作者： Himani Uppal s. swarupa Tripathy sneha Chawla Bharti sharma M.K. dalai s.P. singh sukhvir singh Nahar singh CsIR-National Physical Laboratory New Delhi 110012 India Electronic science Kurukshetra University Kurukshetra Haryana 136119 India Academy of scientific and Innovative Research (AcsIR) India

The present study highlights the potential application of zinc peroxide （ZnO2） nanomaterial as an efficient material for the decontamination of cyanide from contaminated water. A process patent for ZnO2 synthesis has been granted in United states of America （Us Patent number 8,715,612; May 2014）, south Africa, Bangladesh, and India. The ZnO2 nanomaterial was capped with polyvinylpyrrolidone （PVP） to control the particle size. The PVP capped ZnO2 nanomaterial （PVP-ZnO2） before and after adsorption of cyanide was characterized by scanning electron microscope, transmission electron microscope, X-ray diffractorneter, Fourier transform infrared spectroscopy and time of flight-secondary ion mass spectrom- etry. The remaining concentration of cyanide after adsorption by PVP-ZnO2 was determined using ion chromatograph. The adsorption of cyanide over PVP-ZnO2 was also studied as a function of pH, adsorbent dose, time and concentration of cyanide. The maximum removal of cyanide was observed in pH range 5.8-7.8 within 15 rain. The adsorption data was fitted to Langmuir and Fruendlich isotherm and it has been observed that data follows both the isotherms and also follows second order kinetics.

关键词： Cyanide Zinc peroxide Adsorption Ion chromatograph