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PEO-PVP BLENDED Na^+ION CONDUCTING SOLID POLYMERIC MEMBRANES

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Chinese Journal of Polymer Science 2013年第11期31卷 1538-1545页

作者： Angesh chandra Department of Applied Physics Shri Shankaracharya Institute of Professional Management & Technology

Polyethylene oxide （PEO）-polyvinylpyrrolidone （PVP） blended Na＋ ion conducting solid polymeric membranes：（1-x） [75PEO：25NaPO3] ＋ x PVP, where 0 〈 x 〈 12 wt%, are reported. The polymeric blending was done using a solvent- free hot-press method. Two orders of conductivity enhancement （σca. 1.07× 10^-5 S·cm^-1） have been achieved with 3 wt% of PVP （i.e. the composition： [97（75PEO：25NaPO3）＋ 3PVP]）, from that of the pure host：（75PEO：25NaPO3）. The conductivity enhancement in PEO-PVP blended solid polymeric membranes have been explained by the ionic conductivity, ionic mobility and mobile ion concentration measurements. Materials characterization and polymer-salt complexation were done with the help of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, differential scanning calorimetry （DSC） and thermo gravimetric analysis （TGA） studies. The temperature dependent conductivity studies have also been done to compute the activation energy （Ea） values from lgσ-1/TArrhenius plots. A solid state polymeric battery was fabricated by using optimum conducting composition of solid polymer electrolyte （SPE OCC）, and some important cell parameters were also calculated from the discharge profile of the cell.

关键词： Polymer blending Activation energy Ionic conductivity SEM XRD DSC TGA.

SYNTHESIS, CHARACTERIZATION AND ION TRANSPORT PROPERTIES OF HOT-PRESSED SOLID POLYMER ELECTROLYTES (1-x) PEO:x KI

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Chinese Journal of Polymer Science 2013年第2期31卷 302-308页

作者： Angesh chandra Archana chandra K. Thakur Department of Applied Physics Shri Shankaracharya Institute of Prof. Manag. & Tech.Raipur 492015 C.G. India Department of Applied Chemistry Raipur Institute of TechnologyRaipur 492101 C.G. India

Synthesis and ion transport properties of hot-pressed solid polymer electrolytes （SPEs）, （l-x） PEO： x KI, where x is the content of KI in wt%, are reported. A hot-press technique has been used for the formation of the polymeric membranes in place of the usual solution cast method. The composition （80 PEO：20 KI） was identified as the highest conducting polymer electrolyte on the basis of compositional dependent conductivity studies of PEO：KI films. A conductivity enhancement of more than two orders of magnitude from that of the pure PEO was achieved. Materials characterization and ion transport mechanism were explained by using various experimental techniques.

关键词： Solid polymer electrolyte Hot-press technique Ionic conductivity Ionic mobility XRD Polymeric battery.

Non-Newtonian Flow of Blood in a Catheterized Bifurcated Stenosed Artery

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Journal of Bionic Engineering 2018年第1期15卷 173-184页

作者： Jagadis chandra Misrat Gopal chandra Shit Ranjan Pramanik Centre for Healtheare Science and Technology Indian Institute of Engineering Science and Technology Shibpur 711103 lndia Department of Mathematics Jadavpur University Kolkata 700032 India Department of Mathematics Indian Institute of Technology Kharagpur 721302 lndia

The paper is devoted to study the non-Newtonian behavior of blood flowing in an artery having a stenosis, in a situation when a catheter has been inserted into it. The blood rheology is described by Herschel-Bulkley fluid model. The flow configuration is con- structed by choosing suitable curvature at the lateral junction, where the flow separation is initiated. The effects of insertion of catheter and that of yield stress of blood on the velocity distribution, rate of flow and flow resistance of blood, distribution of shear stress at the arterial wall and the location of yield plane are investigated. The results provide some useful information for the prediction/treatment of some arterial diseases and circulatory disorders of the cardiovascular system, in a situation, when a stenosis is developed on the endothelium of the daughter artery / bifurcated artery. The study reveals that if the ratio between the radii of the catheter and the artery is increased, the shear stress at the arterial wall diminishes. However, when the bifurcation angle is increased, the wall shear stress is enhanced.

关键词： Herschel-Bulkley fluid model arterial bifurcation catheterized artery yield plane flow resistance

Upconversion nanoparticles:Recent strategies and mechanism based applications

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Journal of Rare Earths 2022年第9期40卷 1343-1359,I0001页

作者： Neha Dubey Sudeshna chandra Department of Chemistry Sunandan Divatia School of ScienceSVKM's NMIMS(Deemed to-be)UniversityVile Parle(West)Mumbai400056India

Upconversion nanoparticles(UCNPs)doped with lanthanides can convert near-infrared excitation into UV and visible *** of their relatively high emission efficiency,UCNPs are appealing materials for use in a variety of *** are known for low auto-fluorescence,excellent chemical and thermal photo-stability,deep tissue penetration,exceptional biocompatibility,low toxicity,color purity,and ease of surface *** this review,we explain a few recent strategies to boost the efficiency and luminescence of upconversion nanoparticles and minimize quenching by fabricating them as core/shell,nanofibers,or heavily doped *** of UCNPs in drug delivery,Photodynamic therapy(PDT),biosensors,bioimaging,and optogenetics are also discussed along with their mechanism of *** motivation for this review is to understand the working mechanism of UCNPs and their applications in various fields.

关键词： Luminescence Upconversion nanoparticles Optical imaging Mechanism Applications Rare earths

The benefits of yoga in children

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Journal of Integrative Medicine 2018年第1期16卷 14-19页

作者： chandra Nanthakumar Faculty of University Foundation Studies HELP University

The number of children suffering from stress and anxiety in Malaysia is on the rise. Evidence shows that mind-body therapies such as mindfulness therapy, meditation and yoga have been practiced in many other countries to reduce and/or manage the psychological effects of stress and anxiety. This review arti- cle looks at the intervention of yoga as a meditative movement practice in helping school children man- age stress and anxiety. Articles were retrieved using a combination of databases including PubMed/ MEDLINE, and PsyclNFO. Not only peer-reviewed articles, but also those written in English language were included in this review. All studies reviewed had incorporated some form of meditative movement exer- cise. The intervention encompassed asanas （postures）, pranayama （expansion of life force）, dharana （con- centration） and dhyana （meditation）, which are the different paths in yoga. A total of eight articles met the inclusion criteria and were reviewed. The findings of this review reveal that the practice of yoga has brought about, among other things, improvement in managing and reducing stress and anxiety. Despite the limitations in most, if not all of the studies reviewed, in terms of heterogeneity and sample size, yoga appears to be an effective modality for helping children cope with stress and anxiety. It appears that if schools in Malaysia can incorporate yoga as part of the physical education curriculum, it will definitely benefit the students.

关键词： Yoga Stress Physiology Anxiety Child

Synthesis and Characterization of ZnO Nanowires and ZnO–CuO Nanoflakes from Sputter-Deposited Brass(Cu_(0.65)–Zn_(0.35)) Film and Their Application in Gas Sensing

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Journal of Materials Science & Technology 2015年第11期31卷 1069-1078页

作者： Bhagaban Behera Sudhir chandra Centre for Applied Research in Electronics Indian Institute of Technology Delhi

A novel method was presented for synthesis of ZnO and ZnO-CuO composites in the form of nanowires, nanorods and nanoflakes on oxidized silicon substrates. Further, the use of the synthesized nanostructures for gas sensing was demonstrated. Pure brass （Cu0.65-Zn0.35） films were deposited on oxidized Si substrate by radio frequency （RF） diode sputtering. Subsequently, these films having thickness in the range of 100-200 nm were oxidized in different oxidizing ambient in the temperature range of 300-550 ℃. The effect of temperature, time and oxidizing ambient on the growth of nanostructures was investigated by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and photoluminescence （PL） techniques. The nanostructures surface was analyzed by X-ray photoelectron spectroscopy （XPS）. The synthesized nanowires had diameter in the range of 60-100 nm and length up to 50 μm. Based on these observations, the growth mechanism has been suggested. For the nanorods, the diameter was observed to be -150 nm. Samples having dense nanowires, nanorods and nanoflakes were used as a gas sensing material. The performance Of the sensor was investigated for different nanostructured materials for various volatile organic compounds （VOCs）, It was observed that ZnO- CuO nanoflakes were more sensitive to VOC sensing compared to ZnO nanowires and nanorods.

关键词： Brass Thermal oxidation Nanostructures ZnO CuO sensor Sensor Volatile organic compounds (VOCs)

Syntrophic co-culture of Bacillus subtilis and Klebsiella pneumonia for degradation of kraft lignin discharged from rayon grade pulp industry

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Journal of Environmental Sciences 2015年第7期27卷 229-238页

作者： Sangeeta Yadav Ram chandra Department of Environmental Microbiology School for Environmental Sciences Babasaheb Bhimrao Ambedkar University (A Central University)

In order to search the degradability of kraft lignin, the potential bacterial strains Bacillus subtilis（GU193980） and Klebsiella pneumoniae（GU193981） were isolated, screened and applied in axenic and co-culture conditions. Results revealed that mixed culture showed better decolorization efficiency（80%） and reduction of pollution parameters（COD 73% and BOD62%） than axenic culture. This indicated syntrophic growth of these two bacteria rather than any antagonistic effect. The HPLC analysis of degraded samples of kraft lignin has shown the reduction in peak area compared to control, suggesting that decrease in color intensity might be largely attributed to the degradation of lignin by isolated ***, the GC-MS analysis showed that most of the compounds detected in control were diminished after bacterial treatment. Further, the seed germination test using Phaseolus aureus has supported the detoxification of bacterial decolorized kraft lignin for environmental safety. All these observations have revealed that the developed bacterial co-culture was capable for the effective degradation and decolorization of lignin containing rayon grade pulp mill wastewater for environmental safety.

关键词： Degradation GC-MS Kraft lignin Seed germination test Syntropic

Effect of heavy metals and phenol on bacterial decolourisation and COD reduction of sucrose-aspartic acid Maillard product

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Journal of Environmental Sciences 2013年第1期25卷 172-180页

作者： Sangeeta Yadav Ram chandra Department of Environmental Microbiology School for Environmental SciencesBabasaheb Bhimrao Ambedkar University (A Central University)

Melanodins are amino-carbonyl complex, predominantly present in sugarcane molasses based distillery wastewater as major source of colourant. The microbial decolourisafion of melanoidin is a challenge due to its binding property with other co-pollutants of distillery waste. Results revealed that the presence of Zn2＋（2.00-20.00 mg/L） in melanoidin solution （1200 mg/L） stimulated the bacterial growth and sucrose-aspartic acid Maillard product （SAA） decolourisation as compared to control, while Fe3＋ and Mn2＋ at the same concentration inhibited the process. However, the presence of phenol （100 mg/L） along with Zn2＋, Fe3＋ and Mn2＋ suppressed the bacterial growth, SAA decolourisation and MnP activity. The shrinkage and reduced number of bacterial cell count at higher concentration of heavy metals in presence of phenol was also observed under scanning electron microscope.

关键词： degradation manganese peroxidase melanoidin

Journey through the birth, growth and maturity of X-ray astronomy

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Research in Astronomy and Astrophysics 2019年第10期19卷 1-16页

作者： Prahlad chandra Agrawal MU-DAE Centre of Excellence in Basic Sciences Mumbai University Campus at Vidhyanagari

In this biographical account, I recall my scientific journey that began in 1961 when I joined as a Physics Trainee in the BARC Training School and after one year course was admitted in TIFR as a Research Associate. During 1962–1967, I worked on determination of the He^3 /He^4 ratio in cosmic rays using a gas Cerenkov counter and also used a scintillation + solid Cerenkov detector to measure flux of protons and helium nuclei in primary cosmic rays. I also developed a large area scintillation-Cerenkov detector with a spark chamber between them for measuring charge composition of primary cosmic rays. I joined the X-ray astronomy programme in 1967 initiated by Prof. B. V. Sreekantan and played a leading role in developing a balloon borne hard X-ray instrument for studying time variability and energy spectra of cosmic X-ray sources. We carried out a series of balloon experiments and studied temporal intensity variation and energy spectra of X-ray objects like Sco X-1, Cyg X-1, etc. Results on rapid intensity changes and spectra appeared in a series of publications based on which I obtained a Ph.D. degree in 1972. Immediately afterwards, I joined Prof. Gordon Garmire at Caltech as a Research Fellow (a post-doctoral position) to work with him on the low energy component of HEAO A-2 experiment. The instrument was developed and successfully realised. Working on this satellite experiment was a thrilling experience which exposed me to the technical complexities of space instruments. The HEAO-1 satellite was launched in 1978. During 1978–1979, Guenter Riegler and I, working at JPL, reported detection of intense soft X-rays from several classes of extragalactic and Galactic objects like new BL Lacs, a new AM Her binary, coronal X-rays from active stars, etc. After returning to TIFR, I developed a rocket experiment with K. P. Singh to map the spatial and spectral distribution of the Soft Diffuse X-ray Background. At the same time, I also designed 15 cm deep Xenon filled Proportio

关键词： TIFR-X-ray Astronomy by balloons-rockets and satellites-Indian Astronomy Satellite ASTROSAT