检索结果-南通市图书馆

Role of MgF2 addition on high energy ball milled kalsilite:Implementation as dental porcelain with low temperature frit

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2014年第4期3卷 332-338页

作者： Pattem Hemanth kumar Abhinav SRIVASTAVA Vijay kumar Nandini JAISWAL Pradeep kumar Vinay kumar SINGH Department of Ceramic Engineering Indian Institute of Technology(BHU)VaranasiIndia Department of Chemical Engineering Indian Institute of Technology(BHU)VaranasiIndia

Porcelain fused to metal(PFM)has received great attention over the last few years due to its importance in the ***(K_(2)O·Al_(2)O_(3)·SiO_(2))is a high thermal expansion porcelain,suitable for bonding to ***,kalsilite is a metastable phase which gets converted into crystalline leucite upon *** the current work feasibility of developing stable kalsilite phase,dispersion of MgF2 in it as an additive and using mechanochemical synthesis are *** fine dental material has been formulated by mixing prepared kalsilite with low temperature frit(LTF)in different *** crystalline phases evolved in fired powders are characterized by powder X-ray diffraction(XRD)*** with different ratio of LTF has been cold pressed and heat treated to examine its coefficient of thermal expansion(CTE),flexural strength,apparent porosity(AP),bulk density(BD)and *** indicate that MgF_(2) addition and high milling duration help in kalsilite *** also plays an important role in this stabilization,and at 1100℃single phase kalsilite formation is *** outcomes demonstrate that it is easily possible to synthesize a stable single phase kalsilite with desirable properties.

关键词： kalsilite porcelain fused to metal(PFM) dental ceramic mechanochemical synthesis thermal expansion X-ray diffraction(XRD)

Fabrication and characterization of the Ti-Ca-P composites by vacuum sintering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Biomedical Science and Engineering 2011年第9期4卷 583-590页

作者： Dibakar Mondal swapan kumar Sarkar Dong-Won Lee Young-Seon Lee Byong-Taek Lee 不详

Using Ti and biphasic calcium phosphate (BCP) pow-ders, Ti-Ca-P composites which contained 0 - 30 vol.% BCP powders initially, were fabricated by vac-uum sintering at two different sintering temperatures, 1300°C and 1400°C. Detailed microstructural char-acteristics of the resulting composites were investi-gated. Mechanical properties like compressive strength, Vickers hardness were evaluated and they showed decreasing trend with the increasing initial BCP content. The x-ray diffraction (XRD) profiles revealed that extensive chemical reaction occurred and the initial BCP was degraded and formed CaO, TiO2, TiP, CaTiO3. However, the cell viability by MTT assay and cell proliferation behavior through one cell morphology analysis showed excellent in-creasing trend in biocompatibility which makes this materials suitable for hard tissue aid *** the composite containing 30 vol.% BCP content with Ti sintered at 1400°C showed excellent biocompati-bility with the Vickers Hardness value 108.8 HV and the compressive strength value 303.7 MPa.

关键词： Ti Calcium Phosphate Biocompatibility Bio-ceramic

Structural,thermomagnetic,and dielectric properties of Mn0.5Zn0.5GdxFe2-xO4(x=0,0.025,0.050,0.075,and 0.1)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2020年第2期9卷 243-254页

作者： Lakshita PHOR Vinod kumar Hydrogen Lab Department of PhysicsDCR University of Science and TechnologyMurthal-131039HaryanaIndia

In this paper,effect of Gd^3+was investigated on structural,magnetic,and dielectric properties of Mn0.5Zn0.5GdxFe2–xO4(x=0,0.025,0.050,0.075,and 0.1)nanoparticles prepared by facile coprecipitation method.X-ray diffraction(XRD)studies confirmed the single cubic spinel phase for all the samples and showed that lattice parameter(aexp)was found to increase from 8.414 to 8.446Åwith the substitution of Gd3+ions due to their larger ionic radii than the replaced Fe3+*** and size of developed nanoparticles were studied using transmission electron microscopy(TEM)and found that particle size decreased from 31.06 to 21.12 nm for x=0–*** properties showed that maximum magnetization decreased from 39.21 to 23.59 emu/g,and Curie temperature decreased from 192 to 176℃with increase in x from 0 to 0.1 due to weakening of superexchange *** parameters like dielectric constant(e¢ande¢),dielectric loss(tanδ),AC conductivity(σac),and impedance(Z¢and Z¢)as a function of frequency and composition were analyzed and *** was found thate¢,e¢,σac,and tanδvalues decreased with Gd substitution,which has been explained based on Maxwell–Wagner theory and hopping mechanism of electrons between Fe3+and Fe2+ions at octahedral *** plots for all the developed compositions showed single semi-circular arc which indicate the dominant effect of grain boundaries.

关键词： spinel ferrite coprecipitation method structural property magnetism dielectric property

Investigation of structural, morphological and electrochemical properties of mesoporous La2CuCoO6 rods fabricated by facile hydrothermal route

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2020年第7期27卷 987-995页

作者： Jashandeep Singh Ashok kumar Department of Physics National Institute of Technology KurukhsetraHaryana 136119India Department of Applied Sciences National Institute of Technical Teachers Training and ResearchChandigarh 160019India

This work introduces the facile hydrothermal synthesis of double perovskite La2CuCoO6.X-ray diffraction pattern confirmed the formation of a monoclinic phase with P121/c1 *** electron microscopy results revealed that the self-assembled porous rods were composed of nanocrystallite *** estimated specific surface area of these mesoporous rods with an average pore diameter of 6 nm was^41 m^2·g^–*** presence of ions with oxidation states of La^3+,Cu^2+,and Co^2+/Co^3+on the surface of the mesoporous La2CuCoO6 rods was confirmed by X-ray photoelectron spectroscopic *** cyclicvoltammetry and chronopotentiometry,the electrode fabricated from the mesoporous La2CuCoO6 rods were found to exhibit pseudocapacitive behavior with a specific capacitance of 259.4 F·g^–1 at a current density of 0.5 A·g^–***^89%retention in specific capacitance was achieved after 1000 charge/discharge cycles at a constant current density of4 A·g^–1.

关键词： rare earth double perovskites oxide materials hydrothermal electrochemical

Microstructure studies of air-plasma-spray-deposited CoNiCrAlY coatings before and after thermal cyclic loading for high-temperature application

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第8期23卷 934-942页

作者： Dipak kumar K.N.Pandey Dipak kumar Das Mechanical Engineering Department Motilal Nehru National Institute of TechnologyAllahabad-211004India Defense Metallurgical Research Laboratory Hyderabad-500058India

In the present study, bond-coats for thermal barrier coatings were deposited via air plasma spraying（APS） techniques onto Inconel 800 and Hastelloy C-276 alloy substrates. Scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, X-ray diffraction（XRD）, and atomic force microscopy（AFM） were used to investigate the phases and microstructure of the as-sprayed, APS-deposited Co Ni Cr Al Y bond-coatings. The aim of this work was to study the suitability of the bond-coat materials for high temperature applications. Confirmation of nanoscale grains of the γ/γ′-phase was obtained by TEM, high-resolution TEM, and AFM. We concluded that these changes result from the plastic deformation of the bond-coat during the deposition, resulting in Co Ni Cr Al Y bond-coatings with excellent thermal cyclic resistance suitable for use in high-temperature applications. Cyclic oxidative stability was observed to also depend on the underlying metallic alloy substrate.

关键词： thermal barrier coatings coating structure plasma spraying thermal cycle high-temperature applications microstructure studies

Identification of Groundwater in Hard Rock Terrain Using 2D Electrical Resistivity Tomography Imaging Technique: Securing Water Scarcity at the Time of Seasonal Rainfall Failure, South Andaman

在线全文

学校读者我要写书评

暂无评论

International Journal of Geosciences 2018年第1期9卷 59-70页

作者： Maniruzzaman Sk N. Ramanujam Vysakh Champoil swapan kumar Biswas Qazi Akhter Rasool Chandrakanta Ojha Department of Disaster Management Pondicherry University Puducherry India

Like many of the tropical islands, the population of Andaman and Nicobar Islands, though not directly, relies predominantly upon rain water harvesting to quench their need and also depends on the groundwater sources. In the background of climate change, severity of hydrological cycle is much anticipated which may cause more extreme and unusual precipitation. It is quite essential to have other alternatives. Accordingly, groundwater could be exploited as a potential alternative. The present study intends to find out the potential groundwater source and estimate aquifer parameters in Kodiyaghat (KD) and Burmanallah (BN). As these areas are composed of very hard rock, Wenner-Schlumberger array has been used to carry out a 2D Electrical Resistivity Tomography survey to find out the fracture zone as well as to delineate the aquifer. KD and BN show maximum resistivity of 25,416 Ωm and 5985 Ωm indicate very hard rock terrain. Similarly, the minimum values of resistivity (21.6 Ωm and 30.4 Ωm) were observed at KD and BN define the presence of freshwater aquifers respectively. The aquifer identified was found to be at a depth of 5 m to 19.9 m at KD and 2.5 m to 20 m at BN. The calculated Hydraulic conductivity (14.85 m/day and 30.14 m/day), transmissivity (86.25 m2/day and 271.27 m2/day) and porosity (28.7% and 31.24%) values at KD and BN confirmed that, the located aquifer was of fresh ground water quality and can be utilized for drinking and house hold purposes. According to the results, almost 70% of the study area is hard rock terrain and 30% comes under potential aquifer zone. The results also show that, both the areas were characterized by Horst and Graben topography and suggest possible groundwater sources for future exploration.

关键词： Aquifer 2D Electrical Resistivity Wenner-Schlumberger Array Ground Water South Andaman Ophiolite

Non-invasive optical characterization and estimation of Zn porosity in gas tungsten arc welding of Fe–Al joints using CR model and OES measurements

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2023年第11期25卷 133-141页

作者： Sai SRIKAR Tinku kumar Degala Venkata KIRAN Reetesh kumar GANGWAR Department of Physics&CAMOST Indian Institute of Technology TirupatiYerpedu 517619India Department of Mechanical Engineering Indian Institute of Technology TirupatiYerpedu 517619India

In this study,we employed a non-invasive approach based on the collisional radiative(CR)model and optical emission spectroscopy(OES)measurements for the characterization of gas tungsten arc welding(GTAW)discharge and quantification of Zn-induced porosity during the GTAW process of Fe–Al *** OES measurements were recorded as a function of weld current,welding speed,and input *** OES measurements revealed significant line emissions from Zn-I in 460–640 nm and Ar-I in 680–800 nm wavelength ranges in all experimental *** OES coupled CR model approach for Zn-I line emission enabled the simultaneous determination of both essential discharge parameters *** temperature and electron ***,these predictions were used to estimate the Zn-induced porosity using OES-actinometry on Zn-I emission lines using Ar as actinometer *** OES-actinometry results were in good agreement with porosity data derived from an independent approach,i.e.x-ray radiography *** current study shows that OES-based techniques can provide an efficient route for real-time monitoring of weld quality and estimate porosity during the GTAW process of dissimilar metal joints.

关键词： optical emission spectroscopy collisional radiative model actinometry GTAW Fe Al joints Zn vapor porosity radiographic imaging(Some figures may appear in colour only in the online journal)

Orthorectification and Digital Elevation Model (DEM) Generation Using Cartosat-1 Satellite Stereo Pair in Himalayan Terrain

在线全文

学校读者我要写书评

暂无评论

Journal of Geographic Information System 2010年第2期2卷 85-92页

作者： Vivek kumar Singh Prashant kumar Champati ray Ayyeum Perumal Thillai Jeyaseelan 不详

High resolution data have high relief displacement in hilly terrains. Development of Digital Elevation model helps to assess bio resources more accurately in such terrains. While estimating bio resources in the Himalayan hilly terrain using multispectral LISS-III data of 23 m spatial resolution, the need for orthorectifcation of satellite data was necessary to correct for spatial distances due to high undulating slopes. Therefore, Cartosat stereo pair based Digital Elevation Model (DEM) was generated using the Rational Polynomial Coefficients (RPC) supplied along with the data products. By using the DEM orthorectification of LISS-III was created. In order to evaluate the positional accuracy of ortho rectified LISS-III Ground control points were selected using the Global Positioning System in differential GPS mode. As there is variation in the spatial distances and height over few points, the GCP corrected DEM was used for ortho rectifcation of Cartosat PAN and LISS-III data. This paper presents the procedure followed for ortho rectification and digital elevation model generation using Cartosat stereo pair data. The result of the study indicated high spatial resolution stereo images helped generation of three dimensional mountainous regions more accurately which helps in estimating the bio resources using multispectral LISS III data.

关键词： DEM Cartosat Stereo Pair Orthorectification Himalaya

Phosphorus partitioning and recovery of low-phosphorus iron-rich compounds through physical separation of Linz-Donawitz slag

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第7期23卷 751-759页

作者： Dilip Makhija Rajendra kumar Rath Kaushik Chakravarty Abhay Shankar Patra Asim kumar Mukherjee Akhilesh kumar Dubey Research and Development Division Tata Steel Ltd. Mineral Processing Division CSIR-National Metallurgical Laboratory Raw Material Blending and Bedding Section Tata Steel Ltd.

The Linz-Donawitz（LD） steelmaking process produces LD slag at a rate of about 125 kg/t. After metallic scrap recovery, the non-metallic LD slag is rejected because its physical/chemical properties are unsuitable for recycling. X-ray diffraction（XRD） studies have indicated that non-metallic LD slag contains a substantial quantity of mineral phases such as di- and tricalcium silicates. The availability of these mineral phases indicates that LD slag can be recycled by iron（Fe）-ore sintering. However, the presence of 1.2wt% phosphorus（P） in the slag renders the material unsuitable for sintering operations. Electron probe microscopic analysis（EPMA） studies indicated concentration of phosphorus in dicalcium silicate phase as calcium phosphate. The Fe-bearing phases（i.e., wustite and dicalcium ferrite） showed comparatively lower concentrations of P compared with other phases in the slag. Attempts were made to lower the P content of LD slag by adopting various beneficiation techniques. Dry high-intensity magnetic separation and jigging were performed on as-received samples with particle sizes of 6 and 3 mm. Spiral separation was conducted using samples ground to sizes of less than 1 and 0.5 mm. Among these studies, grinding to 0.5 mm followed by spiral concentration demonstrated the best results, yielding a concentrate with about 0.75wt% P and 45wt% Fe.

关键词： steelmaking slag dephosphorization recycling