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Mg2＋-ion Conducting Polymer Electrolytes： Materials Characterization and All-Solid-State Battery Performance Studies

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Journal of Physical Science and Application 2013年第1期3卷 9-17页

作者： rakesh Chandra Agrawal Dinesh kumar Sahu Solid State lonics Research Laboratory SOS in Physics and Astrophysics Pt. Ravishankar Shukla University Raipur 492010India Rungta Engineering College Raipur 492001 India

For All-Solid-State battery applications, Mg2＋-ion conducting polymer electrolytes and Mg-metal electrode are currently considered as alternate choices in place of Li＋-ion conducting polymer electrolytes/Li-metal electrode. Present paper reports fabrication of All-Solid-State battery based on the following Mg2＋-ion conducting nano composite polymer electrolyte （NCPE） films： [85PEO： 15Mg（C104）2] ＋ 5% TiO2 （〈 100 nm）, [85PEO： 15Mg（CIO4）2] ＋ 3% SiO2（-8 nm）. [85PEO： 15Mg（CIO4）2] ＋ 3% MgO （〈 100 nm）, [85PEO：15Mg（C1O4）2] ＋ 3% MgO （-44 μm）. NCPE films were prepared by hot-press technique. Solid Polymer Electrolyte （SPE） composition： [85PEO： 15Mg（CIO4）2], identified as high conducting film at room temperature, has been used as ISt--phase host and nano/micro particles of active （MgO）/passive （SiO2, TiO2） fillers as IInd-phase dispersoid. Filler particle dependent conductivity studies identified above mentioned NCPE films as optimum conducting composition （OCC） at room temperature. Ion transport behavior of SPE/NCPE film materials was investigated previously. Present paper reports materials characterization and cell performance studies on All-Solid-State batteries： Mg （Anode） Ⅱ SPE or NCPE films tt C＋MnO2＋Electrolyte （Cathode）. Open circuit voltage （OCV） obtained was in the range： 1.79-1.92 V. The batteries were discharged at room temperature under different load conditions and some important battery parameters have been evaluated from plateau region of cell-potential discharge profiles. All the batteries performed quite satisfactorily specially under low current drain states.

关键词： Solid polymer electrolyte (SPE) nano composite polymer electrolyte (NCPE) hot-press technique all-solid-state batteries.

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Facile one-pot synthesis of a novel all-carbon stair containing dimerized pentalene core from alkyne

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Chinese Chemical Letters 2022年第4期33卷 2047-2051页

作者： Hui Zhao rakesh kumar Gupta Wei Zhang Jiong Jia Qun Yu Zhiyong Gao Guilin Zhuang Dacheng Li Xingpo Wang Chen Ho Tung Di Sun Key Laboratory of Colloid and Interface Chemistry Ministry of EducationSchool of Chemistry and Chemical EngineeringState Key Laboratory of Crystal MaterialsShandong UniversityJi’nan 250100China College of Chemical Engineering and Materials Science Zhejiang University of TechnologyHangzhou 310032China School of Chemistry and Chemical Engineering Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine ChemicalsKey Laboratory of Green Chemical Media and ReactionsMinistry of EducationHenan Normal UniversityXinxiang 453007China Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology and School of Chemistry and Chemical EngineeringLiaocheng UniversityLiaocheng 252000China

The construction of all-carbon molecule frameworks remains challenging. Herein, we report a facile and efficient one-pot synthesis of a novel all-carbon stair containing dimerized pentalene core using inexpensive cyclopropyl alkyne catalyzed by in situ generated Cu(I) from the comproportionation reaction of Cu(II) salt and Cu powder under mild reaction conditions. The reaction proceeds via sequential acetylenic coupling, followed by cyclization and [2 + 2] cycloaddition to directly produce pentalene dimer, which is difficult to access by other established methods. Different mechanistic paths were studied for the pentalene formation using density functional theory, suggesting that the reaction also proceeds through acetylenic coupling followed by cyclization and [2 + 2] cycloaddition. Based on the activation energy barriers, Path 1 has the rate-determining step of 38.63 kcal/mol, which is the most thermodynamically preferred one among the four paths.

关键词： One-pot synthesis Penatlene dimerization Comproportionation reaction Crystal structure Theoretical calculations

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Predicting heat-stressed EEG spectra by self-organising feature map and learning vector quantizers——SOFM and LVQ based stress prediction

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Journal of Biomedical Science and Engineering 2010年第5期3卷 529-537页

作者： Prabhat kumar Upadhyay rakesh kumar Sinha Bhuwan Mohan Karan 不详

Self-Organising Feature Map (SOFM) along with learning vector quantizers (LVQ) have been designed to identify the alterations in brain electrical potentials due to exposure to high environmental heat in rats. Three groups of rats were considered—acute heat stressed, chronic heat stressed and control groups. After long EEG recordings following heat exposure, EEG data representing three different vigilance states such as slow wave sleep (SWS), rapid eye movement (REM) sleep and AWAKE were visually selected and further subdivided into 2 seconds long epoch. In order to evaluate the performance of artificial neural network (ANN) in recognizing chronic and acute effects of heat stress with respect to the control subjects, unsupervised learning algorithm was applied on EEG data. Mean performance of SOFM with quadratic taper function was found to be better (chronic-92.6%, acute-93.2%) over the other two tapers. The effect of LVQ after the initial SOFM training seems explicit giving rise to considerable improvements in performance in terms of selectivity and sensitivity. The percentage increase in selectivity with uniform taper function is maximum for chronic and its control group (4.01%) and minimum for acute group (1.29%) whereas, with Gaussian it is almost identical (chronic-2.57%, acute-2.03%, control- 2.33%). Quadratic taper function gives rise to an increase of 2.41% for chronic, 1.96% for acute and 2.91% for control patterns.

关键词： ANN EEG Heat Stress SOFM LVQ

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Detection and analysis of the effects of heat stress on EEG using wavelet transform ——EEG analysis under heat stress

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Journal of Biomedical Science and Engineering 2010年第4期3卷 405-414页

作者： Prabhat kumar Upadhyay rakesh kumar Sinha Bhuwan Mohan Karan 不详

Continuous wavelet transform (CWT) method has been applied to capture localized time-frequency information of rat electroencephalogram (EEG) in different vigilance states and analyze alterations in transients during awake, slow wave sleep (SWS), and rapid eye movement (REM) sleep stages due to exposure to high environmental heat. Rats were divided in three group (i) acute heat stress-subjected to a single exposure for four hours in the Biological Oxygen Demand (BOD) incubator at 38?C;(ii) chronic heat stress-exposed for 21 days daily for one hour in the incubator at 38?C, and (iii) handling control groups. After two hours long EEG recordings from young healthy rats, EEG data representing three sleep states was visually selected and further subdivided into 2 seconds long epoch. Powers of wavelet spectra corresponding to delta, theta, alpha, and beta bands at all scales and locations were computed and variation in their states investigated. The wavelet analysis of EEG signals following exposure to high environmental heat revealed that powers of subband frequencies vary with time unlike Fourier technique. Changes in higher frequency components (beta) were significant in all sleep-wake states following both acute and chronic heat stress conditions. Percentage power of different components of the four bands was always found to be varying at different intervals of time in the same signal of analysis.

关键词： Electroencephalogram Rat Sleep Wavelet transform

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Synthesis, Characterization, Optical and Transport Properties of BaSnO<SUB>3</SUB>Synthesized by Wet Chemical Route

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Materials Sciences and Applications 2018年第1期9卷 92-110页

作者： rakesh Kurre Sharmila Bajpai Parmendra kumar Bajpai Department of Pure & Applied Physics Guru Ghasidas Vishwavidyalaya Bilaspur India

Alkaline earth stannates have renewed attention as potential materials for gas sensing, transparent conducting oxides and ceramic capacitor applications. A noble wet chemical route is chosen to synthesize BaSnO3 powders having micron size grains. Problems related to uneven grains and poor densification in conventional solid state route have been overcome in the present method. X-ray diffraction data confirms the single phase formation without any secondary phase having cubic perovskite structure (S.G. Pm-3m). The estimated lattice parameter is ≈4.11933Åand percentage density is ≈90%. The microstructure probed by scanning electron micrograph reveals almost homogeneously distributed particles having random shape with some porosity. Phonon modes in FT-IR and Raman spectra confirm the local symmetry distortion. The DC conductivity at 200°C approaches almost 2 × 10-2 (Ω-cm)-1, which is almost of the same order as that observed in perovskite based electronic conductors. DC and a.c. electrical conductivity of the material follow Mott’s variable range hopping at low temperature and Arrhenius type thermally activated process at elevated temperatures. Evidence of small polar on formation is also verified. Optical band gap estimated from absorption data is ≈2.94 very close to the reported value. Composition prepared through the noble wet chemical route has high electrical conduction and suitable for gas sensing applications.

关键词： X-Ray Diffraction Raman Spectra Variable Range Hopping Phonons

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Radiation dose analysis of computed tomography coronary angiography in Children with Kawasaki disease

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世界临床儿科杂志 2023年第4期12卷 230-236页

作者： Mahesh Chandra Bhatt Manphool Singhal rakesh kumar Pilania Subhash Chand Bansal Niranjan Khandelwal Pankaj Gupta Surjit Singh Department of Radiodiagnosis and Imaging Postgraduate Institute of Medical Education and ResearchChandigarh 160012India Pediatric Allergy Immunology Unit Department of PediatricsAdvanced Pediatrics CentrePost Graduate Institute of Medical Education and ResearchChandigarh 160012India

BACKGROUND There is evolving role of computed tomography coronary angiography(CTCA)in non-invasive evaluation of coronary artery abnormalities in children with Kawasaki disease(KD).Despite this,there is lack of data on radiation dose in this group of children undergoing *** To audit the radiation dose of CTCA in children with *** Study(December 2013-February 2018)was performed on dual source CT scanner using adaptive prospective *** dose length product(DLP in ***)was *** radiation dose(millisieverts-mSv)was calculated by applying appropriate age adjusted conversion factors as per recommendations of International Commission on Radiological *** dose was compared across the groups(0-1,1-5,5-10,and>10 years).RESULTS Eighty-five children(71 boys,14 girls)with KD underwent *** median age was 5 years(range,2 mo-11 years).Median DLP and effective dose was 21 ***,interquartile ranges(IQR)=15(13,28)and 0.83 mSv,IQR=0.33(0.68,1.01)*** DLP increased significantly across the age *** effective dose in infants(0.63 mSv)was significantly lower than the other age groups(1-5 years 0.85 mSv,5-10 years 1.04 mSv,and>10 years 1.38 mSv)(P<0.05).There was no significant difference in the effective dose between the other groups of *** the CTCA studies were of diagnostic *** child required a repeat *** CTCA is feasible with submillisievert radiation dose in most children with ***,CTCA has the potential to be an important adjunctive imaging modality in children with KD.

关键词： Computed tomography coronary angiography Coronary artery abnormalities Dual source computed tomography Kawasaki disease Radiation exposure

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Stability and Leakage Analysis of a Novel PP Based 9T SRAM Cell Using N Curve at Deep Submicron Technology for Multimedia Applications

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Circuits and Systems 2011年第4期2卷 274-280页

作者： Shilpi Birla rakesh kumar Singh Manisha Pattanaik 不详

Due to continuous scaling of CMOS, stability is a prime concerned for CMOS SRAM memory cells. As scaling will increase the packing density but at the same time it is affecting the stability which leads to write failures and read disturbs of the conventional 6T SRAM cell. To increase the stability of the cell various SRAM cell topologies has been introduced, 8T SRAM is one of them but it has its limitation like read disturbance. In this paper we have analyzed a novel PP based 9T SRAM at 45 nm technology. Cell which has 33% increased SVNM (Static Voltage Noise Margin) from 6T and also 22%.reduced leakage power. N curve analysis has been done to find the various stability factors. As compared to the 10T SRAM cell it is more area efficient.

关键词： N Curve Scaling SVNM (Static Voltage Noise Margin) Leakage Power 9T SRAM Cell

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Influence of Pre-Impregnation Treatment on Bamboo Reinforced Epoxy/UPE Resin Composites

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Open Journal of Composite Materials 2012年第4期2卷 139-141页

作者： Pradeep Kr. Kushwaha rakesh kumar Indian Institute of Technology New Delhi India Indian Plywood Industries Research and Training Institute Mohali India

Bamboo based biocomposites were made with woven bamboo mats and epoxy/unsaturated polyester (UPE) resins. The effects of pre-impregnation on the mechanical and water resistant properties of composites were studied. An alkaline treatment was used to enhance the fiber wetting so as to achieve complete pre-impregnation with epoxy and unsaturated polyester resins. A combined treatment of alkali and dilute epoxy/polyester gives the best result. Bending strength, modulus of elasticity, tensile strength, tensile modulus, impact strength, water absorption were evaluated and compared for all composites. Scanning electron microscopy (SEM) studies of the composites tensile fracture surface also indicated that there is an improved adhesion between fiber and matrix. The mechanical as well as water resistant properties of the biocomposites improved after pre-impregnation treatment.

关键词： Biocomposites Pre-Impregnation Epoxy Resin Polyester Resin Mechanical Properties

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Rock fragmentation control in opencast blasting

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第2期8卷 225-237页

作者： P.K.Singh M.P.Roy R.K.Paswan Md.Sarim Suraj kumar rakesh Ranjan Jha CSIR-Central Institute of Mining and Fuel Research

The blasting operation plays a pivotal role in the overall economics of opencast *** blasting subsystem affects all the other associated sub-systems,***,transport,crushing and milling *** control through effective blast design and its effect on productivity are the challenging tasks for practicing blasting engineer due to inadequate knowledge of actual explosive energy released in the borehole,varying initiation practice in blast design and its effect on explosive energy release *** paper describes the result of a systematic study on the impact of blast design parameters on rock fragmentation at three mines in *** mines use draglines and shoveledumper combination for removal of *** its pivotal role in controlling the overall economics of a mining operation,the expected blasting performance is often judged almost exclusively on the basis of poorly defined parameters such as powder factor and is often qualitative which results in very subjective assessment of blasting *** an approach is very poor substitutes for accurate assessment of explosive and blasting *** one blasts were conducted with varying blast designs and charging patterns,and their impacts on the rock fragmentation were documented.A high-speed camera was deployed to record the detonation sequences of the *** efficiency of the loading machines was also correlated with the mean fragment size obtained from the fragmentation analyses.

关键词： Opencast blast Rock fragmentation Explosives performance Dragline efficiency Fragment size

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Controversies in diagnosis and management of Kawasaki disease

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World Journal of Clinical Pediatrics 2018年第1期7卷 27-35页

作者： rakesh kumar Pilania Dharmagat Bhattarai Surjit Singh Department of Pediatrics Advanced Pediatrics Centre Post Graduate Institute of Medical Education and Research (PGIMER)

Kawasaki disease(KD) is a common medium vessel systemic vasculitis that usually occurs in small children. It has a predilection for the coronary arteries, but other medium sized arteries can also be involved. The etiology of this disorder remains a mystery. Though typical presentation of KD is quite characteristic, it may also present as incomplete or atypical disease in which case the diagnosis can be very challenging. As both incomplete and atypical forms of KD can be associated with serious coronary artery complications, the pediatrician can ill afford to miss these diagnoses. The American Heart Association has enunciated consensus guidelines to facilitate the clinical diagnosis and treatment of this condition. However, there are still several issues that remain controversial. Intravenous immunoglobulin remains the cornerstone of management but several other treatment modalities, especially glucocorticoids, are increasingly finding favour. We review here some of the contemporary issues, and the controversies thereon, pertaining to management of KD.

关键词： Kawasaki disease Diagnosis Intravenous immunoglobulin Treatment Controversies

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