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International Journal of Minerals,Metallurgy and Materials 2015年第2期22卷 132-140页

作者： Jagannath pal Satadal Ghorai Avimanyu Das National Metallurgical Laboratory Council of Scientific and Industrial Research

Iron ore microfines and concentrate have very limited uses in sintering processes. They are used in pelletization; however, this process is cost intensive. Furthermore, the microfines of non-coking coal and other carbon-bearing materials, e.g., blast-furnace flue dust （BFD） and coke frees, are not used extensively in the metallurgical industry because of operational difficu]ties and handling problems. In the present work, to utilize these microfines, coal composite iron oxide micropellets （2-6 mm in size） were produced through an innovative technique in which lime and molasses were used as binding materials in the micropellets. The micropellets were subsequently treated with CO2 or the industrial waste gas to induce the chemical bond formation. The results show that, at a very high carbon level of 22wt% （38wt% coal）, the cold crushing strength and abrasion index of the micropellets are 2.5-3 kg/cm2 and 5wt%-9wt%, respectively; these values indicate that the pellets are suitable for cold handling. The developed micropellets have strong potential as a heat source in smelting reduction in iron making and sintering to reduce coke breeze. The micropellets produced with BFD and coke fines （8wt%-12wt%） were used in iron ore sin- tering and were observed to reduce the coke breeze consumption by 3%-4%. The quality of the produced sinter was at par with that of the conventional blast-furnace sinter.

关键词： ironmaking microfines non-coking coal iron ore concentrates micropellets pelletizing, waste utilization

Hybrid fuzzy-grey-Taguchi based multi weld quality optimization of Al/Cu dissimilar friction stir welded joints

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Advances in Manufacturing 2016年第3期4卷 237-247页

作者： Prakash Kumar Sahu Kanchan Kumari Sukhomay pal Surjya K. pal Department of Mechanical Engineering Indian Institute of Technology Guwahati Guwahati Assam 781039 India Department of Mechanical Engineering Indian Institute of Technology Kharagpur Kharagpur West Bengal 721302India

Nowadays aluminum alloys substitute copper in various applications for weight reduction and cost savings. This paper presents fuzzy-grey Taguchi technique for optimization of friction stir welding condition with seven weld quality attributes of dissimilar A1/Cu joints with the minimum number of experiments for effective productivity and product quality. Taguchi＇s L16 orthogonal array was used to conduct the experiments. Fuzzy inference system was adapted to convert the multi quality characteristics into an equivalent single quality parameter which was opti- mized by Taguchi approach. Four parameters namely, rotational speed of the tool, welding speed, plunging depth and tool pin offset were varied in four levels for investi- gating the effects on the process output like tensile strength, compressive strength, percentage of elongation, bending angle, weld bead thickness and average hardness at the nugget zone. The hardness profile is consistent with the variation of the structure within the nugget zone （NZ）. Confirmation experiment was conducted using predicted optimum parameter setting and it showed that the proposed approach could efficiently optimize weld quality parame- ters. The microstructural analyses were also performed for all the zones of the joints at both Al and Cu sides. It revealed the finer grain size at the NZ compared to the base material due to dynamic recrystallization.

关键词： Dissimilar friction stir welding - Grey relational analysis. Fuzzy inference system Multi-response optimization Mechanical properties Microstructural analysis

Influence of A-site cation disorder on structural and magnetocaloric properties of Nd_(0.7–x)La_xSr_(0.3)MnO_3(x=0.0, 0.1, 0.2 & 0.3)

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Journal of Rare Earths 2015年第10期33卷 1072-1080页

作者： Sudharshan Vadnala Prem pal Saket Asthana Department of Physics Indian Institute of Technology Hyderabad

In the present research, the influence of A-site ionic size disorder on structural, magnetic and magnetocaloric properties of Ndo.7_xtaxSr0.3MnO3 （for x=0.0, 0.1, 0.2 ＆ 0.3） compounds were investigated. These compounds were synthesized by solid state reaction route and crystallized in orthorhombic structure with Pnma space group. An average ionic radius 〈rA〉 increased with La-substitution which influenced the physical properties such as the magnetic entropy varying from 4.78 J/kg.K （for x-=0.0） to 3.55 J/kg.K （for x=0.3） and the maximum magnetization at 5 K changing from 3.92 μB （for x=0.0） to 3.59 μB （for x=0.3）. The change in maximum magnetic entropy decreased with increase of A-site average ionic radius. The decrease in magnetic entropy indicated the suppression of lattice disorder that influenced the spin-lattice coupling. The ferromagnetic transition temperature shifted toward room temperature with La substitution. As 〈rA〉 increased, the phase transition changed from first order （for x-=0.0） to second order （for x≥ 0.1） and the refrigeration capacity increased to a significant level. The modest change in magnetic entropy over a wide range of transition temperature might be useful for future active magnetic refrigeration technology.

关键词： manganites magnetocaloric effect relative cooling Curie temperature rare earths

Downstream Decreasing Channel Capacity of a Monsoon-dominated Bengal Basin River: A Case Study of Dwarkeswar River, Eastern India

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Chinese Geographical Science 2020年第5期30卷 900-920页

作者： MALIK Sadhan pal Subodh Chandra Department of Geography University of BurdwanBurdwan 713104West BengalIndia

Downstream changes in channel morphology and flow over the ephemeral Dwarkeswar River in the western part of the Bengal Basin, eastren India were investigated. The river stretches from the Proterozoic Granite Gneiss Complex to the recent Holocene alluvium, forming three distinctive geomorphological regions across the river basin: the pediplane and upper and lower alluvial areas. Sixty cross-sections from throughout the main trunk stream were surveyed and the bankfull width, depth, cross-sectional area, and maximum depth were measured. Sediment samples from each location were studied and the flow velocity, stream power, Manning’s roughness coefficient, and shear stress were estimated. The results show that the bankfull channel cross-section area, width, width-to-depth ratio, and channel capacity increased between the beginning and middle of the river. Thereafter, the size of the river started to decrease in the lower alluvial area. This was characterized by gentle gradients, cohesive bank materials with grass cover, and channel switching. Within the lower part of the river, the channel capacity was observed to diminish as the drainage area increased. This increased the bankfull flow frequency and accelerated large floodwater losses in the floodplain via overbank flows and floodways.

关键词： bankfull channel width bankfull discharge Dwarkeswar River flat alluvial plain channel degradation overbank flow and flood

Microscopic mechanism of unusual lattice thermal transport in TlInTe_(2)

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npj Computational Materials 2021年第1期7卷 1-8页

作者： Koushik pal Yi Xia Chris Wolverton Department of Materials Science and Engineering Northwestern UniversityEvanstonIL 60208USA

We investigate the microscopic mechanism of ultralow lattice thermal conductivity(κl)of TlInTe_(2)and its weak temperature dependence using a unified theory of lattice heat transport,that considers contributions arising from the particle-like propagation as well as wave-like tunneling of *** we use the Peierls–Boltzmann transport equation(PBTE)to calculate the particlelike contributions(κl(PBTE)),we explicitly calculate the off-diagonal(OD)components of the heat-flux operator within a firstprinciples density functional theory framework to determine the contributions(κl(OD))arising from the wave-like tunneling of *** each temperature,T,we anharmonically renormalize the phonon frequencies using the self-consistent phonon theory including quartic anharmonicity,and utilize them to calculateκl(PBTE)andκl(OD).With the combined inclusion ofκl(PBTE),κl(OD),and additional grain-boundary scatterings,our calculations successfully reproduce the experimental *** analysis shows that large quartic anharmonicity of TlInTe_(2)(a)strongly hardens the low-energy phonon branches,(b)diminishes the three-phonon scattering processes at finite T,and(c)recovers the weaker than T^(−1) decay of the measuredκl.

关键词： lattice phonon harmonic

Identification of high-dielectric constant compounds from statistical design

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npj Computational Materials 2022年第1期8卷 1396-1405页

作者： Abhijith Gopakumar Koushik pal Chris Wolverton Department of Materials Science and Engineering Northwestern University2220 Campus DriveEvanstonIL60208USA

The discovery of high-dielectric materials is crucial to increasing the efficiency of electronic devices and ***,we report three previously unexplored materials with very high dielectric constants(69<ϵ<101)and large b... 详细信息

关键词： dielectric high constant

Fabrication of core-shell PLGA/PLA-pNIPAM nanocomposites for improved entrapment and release kinetics of antihypertensive drugs

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Particuology 2018年第5期16卷 169-176页

作者： Tanushree Basu Bonamali pal Satnam Singh School of Chemistry and Biochemistry Thapar lnstitute of Engineering and TechnologyPatiala 147004Punjablndia

Polylactic acid (PLA)and poly(lactic-co-glycolic)acid (PLGA)are two commonly applied biodegrad- able polymers for the preparation of nanocomposites used in drug-delivery ***,these polymers lack desirable attributes such as resistance to aggregation during long-term storage due to *** improve their efficacy,in this work,PLA and PLGA were encapsulated within a shell of poly(N-isopropylacrylamide)(pNIPAM)using a single emulsion technique followed by an aqueous free radical precipitation polymerisation process,yielding core-shell PLA/PLGA-pNIPAM nanocomposites. The nanocomposites were cbaracterised using zeta potential,dynamic light scattering,and transmission electron microscopy analyses and were further applied as a delivery system for ramipril,an antihypertensive *** drug-loaded PLGA-pNIPAM core-shell nanoparticles exhibited a higher drug content (91%)and entrapment efficiency (78%)than their PLA *** in vitro release study of the formulations at pH 7.3in phosphate-buffered saline indicated that PLGA was more efficient than PLA with a sustained release of 86% of ramipril from the polymer matrix within ***,to determine the release kinetics,the data were fitted to Korsmeyer-Peppas and Higuchi models;the release of ramipril from the polymer matrix followed zero-order rate kinetics and an anomalous (non-Fickian)diffusion mechanism.

关键词： Poly(lactic-co-glycolic)acid Polylactic acid Poly(N-isopropylacrylamide) Antihypertensive drug Entrapment efficiency Drug release

Purification and concentration of gluconic acid from an integrated fermentation and membrane process using response surface optimized conditions

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Frontiers of Chemical Science and Engineering 2019年第1期13卷 152-163页

作者： Parimal pal Ramesh Kumar Subhamay Banerjee Environment and Membrane Technology Laboratory Chemical Engineering Department National Institute of Technology Durgapur West Bengal 713209 India Department of Chemistry The University of Burdwan West Bengal 713104 India

A response surface method was used to optimize the purification and concentration of gluconic acid from fermentation broth using an integrated membrane system. Gluconobacter oxydans was used for the bioconversion of the glucose in sugarcane juice to gluconic acid (concentration 45 g·L^-1) with a yield of 0.9 g·g^-1. The optimum operating conditions, such as trans-membrane pressure (TMP), pH, cross-flow rate (CFR) and initial gluconic acid concentration, were determined using response surface methodology. Five different types of polyamide nanofiltration membranes were screened and the best performing one was then used for downstream purification of gluconic acid in a flat sheet cross-flow membrane module. Under the optimum conditions (TMP=12 bar and CFR=400 L·h^-1), this membrane retained more than 85% of the unconverted glucose from the fermentation broth and had a gluconic acid permeation rate of 88% with a flux of 161 L·m^-2·h^-1. Using response surface methods to optimize this green nanofiltration process is an effective way of controlling the production of gluconic acid so that an efficient separation with high flux is obtained.

关键词： gluconic acid optimized nanofiltration green processing process intensification

Sorption behavior of coal for implication in coal bed methane an overview

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International Journal of Mining Science and Technology 2017年第2期27卷 307-314页

作者： Manasi Manjari Mohanty Bhatu Kumar pal N.I.T. Rourkela 769008OdishaIndia Mining Engineering Department N.I.T Rourkela 769008OdishaIndia

CBM has been recognized as a significant natural gas resource for a long time. Recently, CO_2 sequestration in coalbeds for ECBM has been attracting growing attention because of greater concerns about the effects of greenhouse gases and the emerging commercial significance of CBM. Reservoir-simulation technology,as a useful tool of reservoir development, has the capability to provide us with an economic means to solve complex reservoir-engineering problems with efficiency. The pore structure of coal is highly heterogeneous, and the heterogeneity of the pores depends on the coal type and rank.

关键词： ECBM Greenhouse gases Sequestration Adsorption and desorption Porosity and permeability

NMR relaxation and diffusion studies to probe the motional dynamics of risperidone within PLGA microsphere

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Magnetic Resonance Letters 2023年第2期3卷 197-205,I0005页

作者： Deepak Kumar Samanwita pal Department of Chemistry Indian Institute of Technology JodhpurRajasthan342037.India Central Ayurveda Research Institute Kolkata CCRASBidhannagarKolkata700091India

The present study aims to investigate the motional dynamics of risperidone within polylactic co-glycolic acid(PLGA)microsphere by employing solution state'H and 19F nuclear magnetic resonance(NMR)***,a second-generation fluorinated antipsychotic drug used for the treatment of schizophrenia is commercially marketed as PLGA microsphere formulation resulting in prolonged release of the drug in *** the current trend in the pharmaceutical market is to develop drug formulation with long-acting release(LAR)products,complete physicochemical characterization of such formulations are *** the effects of microsphere encapsulation on the motional properties and diffusion behavior of the drugs are not discussed adequately in any of the earlier *** therefore,have employed NMR relaxation and diffusion measurements to decipher the interaction of PLGA cavity water with risperidone.A detailed analysis of NMR relaxation rates confirmed the event of encapsulation and the presence of local motion in the non-fluorinated end of ***,the relaxation data indicated a significant alteration in 19F chemical shift anisotropy(CSA)and CSA/dipole-dipole(DD)cross-correlated relaxation mechanism and decreased effect of solvent relaxation pointing out reduced water concentration within the microsphere cavity.'H and 19F diffusion coefficients of risperidone led to the information about hydrodynamic radius of risperidone in free and encapsulated *** of hydrodynamic radius supported the presence of limited water in PLGA cavity allowing higher translational mobility of risperidone after the encapsulation.

关键词： Polylactic co-glycolic acid(PLGA)microsphere Motional dynamics 1H and 19F NMR Diffusion Hydrodynamic radius Cross-correlated relaxation