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Friction 2020年第5期8卷 945-956页

作者： Shishobhan sharma Bharat PATEl Rasmika PATEl Department of Materials Science Sardar Patel UniversityVallabh VidyanagarAnandGujarat 380012India Kana Advanced Composites Industry PORVadodaraGujarat 380012India

Friction and wear characteristics correlating the fiber reinforcement percentage of carbon–carbon (C/C) composites solely developed from petroleum pitch matrices were investigated. This study exhibits the tribo-characteristics of C/C composites developed in a single-step carbonization process for varying loads for the first time without a reimpregnation process. A pin-on-disc tribometer with a sliding speed of 0.5 m/s and loads of 5, 10, and 20 n with a flat tool grade stainless steel pin as a static partner was employed. Further, polarized light optical and scanning electron microscopes (SEM) were utilized for a morphological analysis. Elastic modulus and strength were determined by a compression test. A result analysis is conducted to analyze sliding wear accompanied with minor abrasion. The composites with a high percentage of reinforcement exhibit credible wear resistance and mechanical robustness.

关键词： carbon sliding wear microstructure composite friction pitch characterization

Kinetics and mechanistic study of n-alkane hydroisomerization reaction on Pt-doped g-alumina catalyst

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Petroleum 2017年第4期3卷 489-495页

作者： Abhishek Dhar Rohit l.Vekariya Pushan sharma Department of Science&Technology Government of West BengalVigyan Chetana Bhavan Plot no.26/BBlock DDSector e ISalt LakeKolkata 64India School of Chemical Engineering Fuzhou UniversityFuzhou 350116Fujian ProvincePR China Department of Mechanical Engineering Indian Institute of TechnologyDelhiHauz KhasNew Delhi 110016India

The catalysts g-alumina(GA,the reference catalyst)and Pt doped g-alumina(PGA-s)were synthesized using a simple sol-gel technique,in which at first preparation of porous base(GA),then impregnation of platinum salt over the base and finally reduction of platinum in the surface of the support were *** catalysts prepared in different mole ratios of Pt:Al as 2:1,1:1 and 1:2 are named as PGA-1,PGA-2 and PGA-3 *** isomerization of n-alkanes(n-hexane,nheptane and n-octane)were investigated over the synthesized *** 2-methyl pentane(2-MP),2,2-dimethyl pentane(2,2-DMP)and 2,3-dimethyl hexane(2,3-DMH)are the major products of respective isomerization of n-hexane,n-heptane and n-octane,besides a small amount of other branched isomers are also *** product distribution is comparable to that reported for Pt based other *** optimal mole ratios of Pt:Al is 1:1(PGA-2)gives quite good catalytic activity for isomerization of *** through in reusability study,PGA-2 gives better performance than *** have mainly focused on kinetic study,reaction mechanism behind isomerization and calculated the order of reactions and activation energies of the isomerization reactions in the present work.

关键词： Isomerization n-alkanes Catalyst Reaction mechanism Kinetics study Activation energy

A novel method of water remediation of organic pollutants and industrial wastes by solution- route processed CZTS nanocrystals

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Journal of Materiomics 2021年第5期7卷 904-919页

作者： Pooja Semalti Vikash sharma Shailesh narain sharma CSIR-national Physical laboratory(nPl) Dr.K.S.Krishnan RoadNew Delhi110012India Academy of Scientific and Innovative Research(AcSIR) Council of Scientific&Industrial Research(CSIR)-Human Resource Development Centre(CSIRHRDC)CampusGhaziabadUttar Pradesh201002India

CZTS(Cu_(2)ZnSnS_(4)),a P-type semiconductor with a direct bandgap(1.2-1.7eV),earth-abundant,non-toxic,and has a large absorption coefficient makes it extremely useful in optoelectronics and light-harvesting *** this work,CZTS is prepared by an ingenious,cost-effective colloidal route using the‘hotinjection’method with the usage of different *** XRD and Raman spectroscopy shows the single-phase highly crystalline CZTS nanoparticles with kesterite *** TEM results show that the size of CZTS nanoparticles is about 2-5 nm and monodispersity is confirmed by DlS(Dynamic light Scattering).FTIR confirms the presence of different ligands used in CZTS *** Uv-vis absorption shows the direct bandgap of *** contact angle study shows the hydrophobic nature of as-synthesized CZTS nanoparticles which were further ligand exchanged with l-cysteine hydrochloride to make it hydrophilic to study the photocatalytic degradation activity of organic pollutants and industrial waste in the *** photocatalysis experiments were performed under two conditions:(i)under bare sunlight(Intensity~900 W/m^(2))(ii)focussing the sample under the sunlight via converging lens(1800 W/m^(2)).The photocatalytic efficiencies were then compared and the best photocatalytic efficiency achieved under sunlight was 98.4%for organic pollutants and 75%for industrial waste via converging lens while the corresponding efficiencies with bare sunlight were 98.1% and 73% *** the best of the author’s knowledge,a rapid and highly efficient photocatalysis of CZTS nPs employing a converging lens for water-remediation without the usage of noble&transition-metals has been reported for the first time.

关键词： Photocatalysis Copper zinc tin sulfide(CZTS) Converging lens Industrial waste Hot injection Organic pollutants nanoparticles TOP TOPO

new Phenomenon of the Hysteresis of 4He in Vycor Glass

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Chinese Physics letters 1992年第2期9卷 83-85页

作者： JIn Xin XU Xiaonong YAn Yong A.l.Thomson D.F.Brewer S.Haynes n.sharma Department of Physics Nanjing UniversityNanjing 210008 Physics Building University of Sussex Brighton BN19QHEngland

The low t emperature part of hysteresis curves of the freezing and melting processes of ^(4)He in vycor glass with the lowest temperature O.4K were measured,as the pressure ranged from 36.45 to 55.18(1O^(5)Pa).Some novel characteristics of these curves were observed in such high temperature and pressure *** may result from the existence of superfluid ^(4)He.

关键词： freezing hysteresis curves

Effect of hydrogen bond formation/replacement on solubility characteristics, gastric permeation and pharmacokinetics of curcumin by application of powder solution technology

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Acta Pharmaceutica Sinica B 2016年第6期6卷 600-613页

作者： Vijay sharma Kamla Pathak Department of Pharmaceutics Rajiv Academy for Pharmacy

The present research aimed to improve the dissolution rate and bioavailability of curcumin using the potential of liquisolid technology. Twelve drug-loaded liquisolid systems (lS-1 to lS-12) were prepared using different vehicles (PEG 200, PEG 400 and Tween 80) and curcumin concentrations in vehicle (40%, 50%, 60% and 70%, w/w). The carrier [microcrystalline cellulose (MCC) PH102] to coat (Aerosil®) ratio was 20 in all formulations. The systems were screened for pre-compression properties before being compressed to liquisolid tablets (lT-1 to lT-12). Post compression tests and in vitro dissolution of lTs were conducted and the results compared with those obtained for a directly compressed tablet (DCT) made of curcumin, MCC PH102 and Aerosil®. lTs exhibited higher cumulative drug release (CDR) than the DCT and the optimum formulation, lT-9 (made using Tween 80), was studied by powder XRD, DSC, SEM and FTIR. Ex-vivo permeation of curcumin from lT-9 through goat gastrointestinal mucosa was significantly (Pnhanced and its oral bioavailability was increased 18.6-fold in new Zealand rabbits. In vitro cytotoxicity (IC50) of lT-9 towards nCl 87 cancer cells was 40.2 µmol/l substantiating its anticancer efficacy. Accelerated stability studies revealed insignificant effects of temperature and humidity on lT-9. In summary, solubility enhancement of curcumin in lTs produced significant improvements in its permeation and bioavailability.

关键词： liquisolid tablet Powder solution technology Curcumin Hydrogen bond formation Cytotoxicity Gastric permeation Bioavailability Pharmacokinetics

A theoretical investigation of the band alignment of type-I direct band gap dilute nitride phosphide alloy of Gan_xAs_yP_(1-x-y)/GaP quantum wells on GaP substrates

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Chinese Physics B 2014年第7期23卷 640-644页

作者： O l nsal B Gnül M Temiz Department of Engineering Physics University of Gaziantep

The GaP-based dilute nitride direct band gap material Ga（nAsP） is gaining importance due to the monolithic integra- tion of laser diodes on Si microprocessors. The major advantage of this newly proposed laser material system is the small lattice mismatch between GaP and Si. However, the large threshold current density of these promising laser diodes on Si substrates shows that the carrier leakage plays an important role in Ga（nAsP）/GaP QW lasers. Therefore, it is necessary to investigate the band alignment in this laser material system. In this paper, we present a theoretical investigation to optimize the band alignment of type-I direct band gap GanxAsyP1-x-y/GaP QWs on GaP substrates. We examine the effect of nitrogen （n） concentration on the band offset ratios and band offset energies. We also provide a comparison of the band alignment of type-I direct band gap GanxAsyP1-x-y/GaP QWs with that of the GanxAsyP1-x-y/Al2Ga1-2P QWs on GaP substrates. Our theoretical calculations indicate that the incorporations of n into the well and AI into the barrier improve the band alignment compared to that of the GaAsP/GaP QW laser heterostructures.

关键词： quantum well band alignment carrier confinement dilute nitride phosphide alloy

large-Scale Estimation of Distribution Algorithms with Adaptive Heavy Tailed Random Pro jection Ensembles

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Journal of Computer Science & Technology 2019年第6期34卷 1241-1257页

作者： Momodou l.Sanyang Ata Kabán School of Computer Science University of BirminghamEdgbastonBirmingham B152TTU.K. School of Information Technology and Communication University of The GambiaSerekundaThe Gambia

We present new variants of Estimation of Distribution Algorithms (EDA) for large-scale continuous optimisation that extend and enhance a recently proposed random projection (RP) ensemble based approach. The main novelty here is to depart from the theory of RPs that require (sub-)Gaussian random matrices for norm-preservation, and instead for the purposes of high-dimensional search we propose to employ random matrices with independent and identically distributed entries drawn from a t-distribution. We analytically show that the implicitly resulting high-dimensional covariance of the search distribution is enlarged as a result. Moreover, the extent of this enlargement is controlled by a single parameter, the degree of freedom. For this reason, in the context of optimisation, such heavy tailed random matrices turn out to be preferable over the previously employed (sub-)Gaussians. Based on this observation, we then propose novel covariance adaptation schemes that are able to adapt the degree of freedom parameter during the search, and give rise to a flexible approach to balance exploration versus exploitation. We perform a thorough experimental study on high-dimensional benchmark functions, and provide statistical analyses that demonstrate the state-of-the-art performance of our approach when compared with existing alternatives in problems with 1000 search variables.

关键词： covariance adaptation estimation of distribution algorithm random projection ensemble t-distribution

Multifunctional nanocomposites modulating the tumor microenvironment for enhanced cancer immunotherapy

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Bioactive Materials 2024年第1期31卷 440-462页

作者： Prashant sharma Mario Otto Department of Child Health University of Arizona College of Medicine-PhoenixABC1 Building425 N 5th StreetPhoenixAZ85004USA Center for Cancer and Blood Disorders(CCBD) Phoenix Children’s1919 E Thomas RdPhoenixAZ85016USA

Cancer immunotherapy has gained momentum for treating malignant tumors over the past *** blockade and chimeric antigen receptor cell therapy(CAR-T)have shown considerable potency against liquid and solid ***,the tumor microenvironment(TME)is highly immunosuppressive and hampers the effect of currently available cancer immunotherapies on overall treatment *** in the design and engineering of nanomaterials have opened new avenues to modulate the *** in the current nanocomposite technology can overcome immunosuppression and trigger robust immunotherapeutic responses by integrating synergistic functions of different *** will review recent advancements in nanomedical applications and discuss specifically designed nanocomposites modulating the TME for cancer *** addition,we provide information on the current landscape of clinical-stage nanocomposites for cancer immunotherapy.

关键词： Tumor microenvironment nanocomposites Immunotherapeutic Cancer Immunosuppressive

Internal transcribed spacer guided multiplex PCR for species identification of Convolvulus prostratus and Evolvulus alsinoides

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Acta Pharmaceutica Sinica B 2016年第3期6卷 253-258页

作者： Sonal sharma neeta Shrivastava B.V. Patel Pharmaceutical Education and Research Development (PERD) Centre Sarkhej-Gandhinagar Highway nirma University

Shankhpushpi is a reputed drug from an Indian system of medicine for treating mental disorders and enhancing memory. Two herbs, namely Convolvulus prostratus Forssk. and Evolvulus alsinoides(l.) l., are commonly known as Shankhpushpi. Ambiguous vernacular identity can affect the scientific validity of the Shankpushpi-based herbal drug therapy. In the present investigation, a novel and sensitive multiplex PCR method based on polymorphism in the internal transcribed spacer(ITS) region was developed to establish the molecular identity of C. prostratus and E. alsinoides. DnA was isolated and the ITS region was amplified, sequenced and assembled. Sequences were aligned to identify variable nucleotides in order to develop plant-specific primers. Primers were validated in singleplex reactions and eventually a multiplex assay was developed. This assay was tested for sensitivity and validated by amplifying DnA isolated from the simulated blended powdered plant material. Primers developed for C. prostratus resulted into a 200 bp amplicon and 596 bp for E. alsinoides. The assay was found to be sensitive enough for amplification of low quantities of DnA. The method can detect 10% of the mixing of plants with each other in blended material. This PCR assay can be used for rapid botanical identification of Shankhpushpi plant materials and will improve evidence-based herbal drug therapy.

关键词： PCR Internal transcribed spacers Shankhpushpi Botanical identification Adulteration Substitution Herbal drugs DnA barcoding

Plant Disease Diagnosis and Image Classification Using Deep learning

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Computers, Materials & Continua 2022年第5期71卷 2125-2140页

作者： Rahul sharma Amar Singh Kavita n.Z.Jhanjhi Mehedi Masud Emad Sami Jaha Sahil Verma School of Computer Applications Lovely Professional University Jalandhar144411India Department of Computer Science and Engineering Chandigarh UniversityMohaliIndia Department of Computer Science and Engineering Tailor’s UniversityMalaysia Department of Computer Science College of Computer and Information TechnologyTaif UniversityTaif21944Saudi Arabia Department of Computer Science Faculty of Computer and Information TechnologyKing Abdulaziz UniversityJeddah21589Saudi Arabia

Indian agriculture is striving to achieve sustainable intensification,the system aiming to increase agricultural yield per unit area without harming natural resources and the *** farming employs technology to improve *** and accurate analysis and diagnosis of plant disease is very helpful in reducing plant diseases and improving plant health and food crop *** disease experts are not available in remote areas thus there is a requirement of automatic low-cost,approachable and reliable solutions to identify the plant diseases without the laboratory inspection and expert’s *** learning-based computer vision techniques like Convolutional neural network(Cnn)and traditional machine learning-based image classification approaches are being applied to identify plant *** this paper,the Cnn model is proposed for the classification of rice and potato plant leaf *** leaves are diagnosed with bacterial blight,blast,brown spot and tungro *** leaf images are classified into three classes:healthy leaves,early blight and late blight *** leaf dataset with 5932 images and 1500 potato leaf images are used in the *** proposed Cnn model was able to learn hidden patterns from the raw images and classify rice images with 99.58%accuracy and potato leaves with 97.66%*** results demonstrate that the proposed Cnn model performed better when compared with other machine learning image classifiers such as Support Vector Machine(SVM),K-nearest neighbors(Knn),Decision Tree and Random Forest.

关键词： Plant diseases detection Cnn image classification deep learning in agriculture