检索结果-南通市图书馆

Journal of Electromagnetic Analysis and Applications 2012年第6期4卷 230-234页

作者： Jitendra Kr. Sah Sun Chatterjee pragya bharati Dia Ghosh Aditi Anand Sudipta Chattopadhyay Department of ECE Siliguri Institute of Technology P.O-Sukna Darjeeling 734009 WB India

A simple rectangular microstrip antenna on low dielectric constant substrate such as air for improved radiation beam performance is theoretically investigated. The conventional patch antenna fabricated on common substrates always produces quite broader E plane pattern compared to its H plane. In the present investigation, the same microstrip antenna is designed on air substrate with a view to develop an efficient feed for parabolic reflector antenna, which shows an excellent radiation pattern with symmetrical 3 dB beam widths at its both E and H plane. The present antenna compared to conventional structure to show its excellence in the beam performance is presented. The complete quantitative analysis to explore such radiation beam characteristics for both the structures (conventional and the present one) is also presented in this paper. An easy and handful relationship between the length of patch antenna and its fringing length for different types of substrate is established in the background of 3 dB beam widths. The proposed idea has been verified through a commercial software package for a patch operating in X band and a concrete physical insight into the phenomenon is developed.

关键词： Air Substrate Rectangular Microstrip Antenna Symmetrical Beam widths.

Effect of orientation on the drag of a cone settling in a Bingham plastic fluid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2019年第2期17卷 157-170页

作者： pragya Mishra A.K. Tiwari R.P. Chhabra Department of Chemical Engineering. Indian Institute of Technology Kanpur 208016 India M2NeT Laboratory Wilfrid Laurier University 75 University Avenue West Waterloo ON N2L 3C5 Canada

Effects of the orientation and apex angle on the settling velocity of conical particles in Bingham plas-tic fluids are numerically investigated over a Reynolds number range of 1 ≤Re ≤100, Bingham number range of 0 ≤ Bn ≤ 100, and cone angle range of 20 ≤α≤ 150°. Governing equations (of continuity and momentum) are solved numerically using the finite element method to obtain velocity and pressure fields that are postprocessed to obtain values of the drag ***, the effect of cone ori-entation on the flow field is visualized and explored in terms of streamline contours and the morphology of yielded/uny ielded regions. Finally, the obtai ned values of drag are correlated via a simple predictive expression in terms of the modified Reynolds number. The effect of the cone angle on drag is found to be moderate because the drag force acting on the lateral surface is a small fraction of the overall drag.

关键词： Bingham number Reynolds number Yielded/unyielded regions Drag

In vivo antianxiety and antidepressant activity of Murraya paniculata leaf extracts

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 Integrative Medicine 2017年第4期15卷 320-325页

作者： pragya Sharma Sonali Batra Ashwani Kumar Anupam Sharma University Institute of Pharmaceutical Sciences Panjab University

OBJECTIVE： Different parts of Murraya paniculata have been used traditionally for treating several ailments including mental disorders. The present study was designed to evaluate the antianxiety and antidepressant potential of M. paniculata leaves using elevated plus maze model and forced swim test, respectively. METHODS： Extracts of M. panicu/ata made with petroleum ether （60-80 ℃）, chloroform, ethanol and water were evaluated for antianxiety and antidepressant activity. The anxiolytic chloroform extract was subjected to column chromatography, yielding five fractions （F1-F5）. Fraction F5 （100 mg/kg）, which showed notable anxiolytic activity, was further chromatographed to get four subfractions （F5.1-F5.4）. Simultaneously, the ethano extract was partitioned with ethyl acetate to obtain ethyl acetate soluble fraction （EASF） and ethyl acetate insoluble fraction. Phytochemical screening of bioactive extracts/fractions and detection of mahanimbine in M paniculata leaf extract by thin-layer chromatography was also carried out. RESULTS： Fraction F5.3 （25 mg/kg） and EASF （20 mg/kg） showed significant anxiolytic and antidepressant activity, respectively. Thin-layer chromatography and phytochemical screening demonstrated the absence of mahanimbine in M. paniculata leaves. Coumarins were observed to be responsible for the anxiolytic activity. CONCLUSION： The results validate the traditional use of M. paniculata leaves in the treatment of menta disorders.

关键词： Murraya paniculata anxiety depressant coumarins mahanimbine plants, medicinal

Coal fy ash:an emerging material for water remediation

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2022年第3期9卷 18-49页

作者： N.B.Singh Anupam Agarwal Anindita De pragya Singh Department of Chemistry and Biochemistry Sharda UniversityGreater NoidaIndia

Coal fy ash(CFA)is a byproduct of thermal power plant and collected from fue gases by *** of CFA depends on the type of coal used and it has both crystalline and amorphous *** is considered to be an environmental pollutant and used in number of *** is a useful material and widely used in cement production and as a promising adsorbent for water *** used for remediation of wastewater solves problems related to water quality issues and waste *** physical properties such as porosity,surface area,morphology,and chemical composition(iron oxide,alumina,silica,titania,etc.)make CFA efcient material for wastewater *** is also converted to geopolymer,which is used as an adsorbent and ***,organic compounds,toxic heavy metal ions,*** been removed using CFA and modifed CFA *** adsorption efciencies have been reported for diferent adsorbate and CFA *** of adsorption isotherm and kinetic models have been discussed.

关键词： Coal fy ash Adsorbent Dye Geopolymer Water remediation Pollutants

Green synthesis of biocompatible gold nanoparticles using Fagopyrum esculentum leaf extract

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2011年第4期5卷 379-387页

作者： Punuri Jayasekhar BABU pragya SHARMA Mohan Chandra KALITA Utpal BORA Biotech Hub Centre for the Environment Indian Institute of Technology Guwahati Guwahati Assam-781039 India Biomaterials and Tissue Engineering Laboratory Department of Biotechnology Indian Institute of Technology Guwahati Guwahati Assam-781039 India Department of Biotechnology Gauhati University Guwahati Assam-781039 India

This report describes the use of ethnolic extract of Fagopyrum esculentum leaves for the synthesis of gold nanoparticles. UV-visible spectroscopy analysis indicated the successful formation of gold nanoparticles. The synthesized nanoparticles were characterized by transmission electron microscopy （TEM）, high resolution TEM （HRTEM） and were found to be spherical, hexagonal and triangular in shape with an average size of 8.3 nm. The crystalline nature of the gold nanoparticles was confirmed from *** diffraction （XRD） and selected-area electron diffraction （SAED） patterns. Fourier transform infrared （FT-IR） and *** X-ray analysis （EDX） suggested the presence of organic biomolecules on the surface of the gold nanoparticles. Cytotoxicity tests against human HeLa, MCF-7 and IMR-32 cancer cell lines revealed that the gold nanoparticles were non-toxic and thus have potential for use in various biomedical applications.

关键词： biomaterials crystal growth electron microscopy Fourier transforminfrared spectroscopy adsorption

Mental health service users'progression from illicit drug use to schizophrenia in New Zealand

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

General Psychiatry 2019年第5期32卷 257-260页

作者： Graham Mellsop Rees Tapsell pragya Holmes Research Contractor AucklandNew Zealand University of Auckland Waikato Clinical School HamiltonNew Zealand

Background Recently,publications have hypothesised that the demonstrated increase in the incidence of schizophrenia in New Zealand is a side effect of the increased strength of available cannabis derivatives over the last 25+years and the much more recent increase in the population's use of *** To compare the rates of later schizophrenia between age-matched mental health service users with initial diagnoses as alcohol abusers or illicit drug *** From the PRIMHD comprehensive national database,all users of the mental health services over a 5-year period who received an ICD-10 presenting diagnosis of alcohol or substance use/abuse were *** each person identified,the database was examined for the following 3 years to determine the numbers later diagnosed with *** For the initial alcohol problem people in their twenties,1.7%were diagnosed as suffering from schizophrenia in the subsequent 3 *** the initial drug problem people,the rate was 10.9%.Within that drug-using population,the indigenous Maori developed schizophrenia at a higher rate than did the remainder of the *** These findings in New Zealand require further research into their generalisability,context and explanation.

关键词： schizophrenia alcohol service

Gold nanoparticles： sonocatalytic synthesis using ethanolic extract of Andrographis paniculata and functionalization with polycaprolactone-gelatin composites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2012年第3期6卷 236-249页

作者： Punuri Jayasekhar BABUA Sibyala SARANYA pragya SHARMA Ranjan TAMULI Utpal BORA Biomaterials and Tissue Engineering Laboratory Department of BiotechnologyIndian Institute of Technology GuwahatiGuwahatiAssam-781039India Biotech Hub Centre for the EnvironmentIndian Institute of Technology GuwahatiGuwahatiAssam-781039India Department of Biotechnology D.R.W.CollegeGudurSPS NelloreAndhra Pradesh-524101India

Gold nanoparticles （AuNPs） were synthesized by sonication using ethanolic leaf extract of Andrographis paniculata. We investigated the optimum parameters for AuNP synthesis and functionalization with polycaprolactone-gelatin （PCL-GL） composites. The AuNPs were characterized with various biophysical techniques such as TEM, XRD, FT-IR and EDX spectroscopy. TEM images showed that nanoparticles were spherical in shape with a size range from 5 to 75 nm. EDX analysis revealed the presence of molecular oxygen and carbon on the surface of AuNPs. The synthesized AuNPs were tested for their effect on HeLa （human cervical cancer） and MCF- 7 （human breast cancer） cell lines and found to be nontoxic and biocompatible, which are potential carriers for hydrophobic drugs.

关键词： sonocatalasis Andrographis paniculata functionalization crystal growth biomaterial PCL-GL composite

Precise Control of Highly Ordered Arrays of Nested Semiconductor/Metal Nanotubes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2011年第2期4卷 164-170页

作者： Diefeng Gu Helmut Baumgart Kandabara Tapily pragya Shrestha Gon Namkoong Xianyu Ao Frank Müller Department of Electrical Engineering Old Dominion University Norfolk Virginia 23529 USA The Applied Research Center Newport News Virginia 23606 USA Max Planck Institute of Microstructure Physics Halle Germany

Lithographically defined microporous templates in conjunction with the atomic layer deposition （ALD） technique enable remarkable control of complex novel nested nanotube structures. So far three-dimensional control of physical process parameters has not been fully realized with high precision resolution, and requires optimization in order to achieve a wider range of potential applications. Furthermore, the combination of composite insulating oxide layers alternating with semiconducting layers and metals can provide various types of novel applications and eventually provide unique and advanced levels of multifunctional nanoscale devices. Semiconducting TiO2 nanotubes have potential applications in photovoltaic devices. The combination of nanostructured semiconducting materials with nested metal nanotubes has the potential to produce novel multi functional vertically-ordered three-dimensional nanodevices. Platinum growth by ALD has been explored, covering the initial stages of the thin film nucleation process and the synthesis of high aspect ratio nanotube structures. The penetration depth of the Pt into porous templates having various pore sizes and aspect ratios has been investigated. Several multi-walled nested TiO2-Pt nanotubes in series have been successfully fabricated using microporous Si templates. These innovative nested nanostructures have the potential to produce novel multifunctional vertically-ordered three-dimensional nanodevices in photovoltaic and sensing technologies.

关键词： Atomic layer deposition (ALD) platinum nanotubes semiconductor/metal nanotubes microporous Si templates nanoporous alumina templates multilayer nested nanotubes

Distinguishing celadonite from glauconite for environmental interpretations:a review

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 Palaeogeography 2023年第2期12卷 179-194页

作者： pragya Singh Santanu Banerjee Tathagata Roy Choudhury Satadru Bhattacharya Kanchan Pande Department of Earth Sciences Indian Institute of Technology BombayPowaiMumbai400076India Space Applications Centre Indian Space Research OrganisationAhmedabad380015India

Celadonite and glauconite are comparable in terms of physical,chemical and mineralogical *** of both these minerals requires slightly oxygen-depleted conditions in a semiconfined micro-environment,facilitating the uptake of Fe into the *** glauconite is ubiquitous in marine deposits,celadonite forms in both marine and non-marine environments,more commonly by altering intermediate to mafic rocks.A review of data across the geological column shows that both these minerals are more common in the Mesozoic and Cenozoic,which may be related to extensive *** composition of celadonite and glauconite is highly variable and is controlled by the availability of cations within the pore water *** major element composition of celadonite overlaps with that of evolved to highly evolved glauconite to a large *** data and representative samples of celadonite and glauconite reveal subtle differences in X-ray diffraction parameters and Fourier transform infrared(FTIR)*** shows sharper basal and hkl reflections than *** characteristically exhibits distinct 111-021,003-022,023 and 130-131,and 060 reflections at less than 1.51A,indicating a betterordered crystallographic structure than *** FTIR spectra of celadonite and glauconite show similar absorption bands although Si-O bending,Si-O stretching and OH-stretching bands are sharper and well resolved in celadonite than that of *** palaeoenvironmental interpretations,it is,therefore,necessary to examine the subtle differences in X-ray diffraction parameters and FTIR spectra to confirm the identification of these two *** composition of celadonite relates closely to the host rock and depositional *** celadonite associated with mafic rock shows relatively high Fe,Mg and low Al *** contrast,those associated with felsic to intermediate composition rocks show slightly higher contents of Al and

关键词： Celadonite Glauconite Authigenic green silicates Large igneous province Marine Fourier transform infrared spectroscopy X-ray diffraction

New focus of Kyasanur Forest disease virus activity in a tribal area in Kerala, India, 2014

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Infectious Diseases of Poverty 2015年第1期4卷 122-125页

作者： Babasaheb V Tale Anukumar Balakrishnan pragya D Yadav Noona Marja Devendra T Mourya National Institute of Virology(NIV) 20-ADr Ambedkar RoadPuneMaharashtra 411001India National Institute of Virology Kerala Unit AlappuzhaKeralaIndia Deputy District Medical Officer(Public Health) MalappuramKeralaIndia

Background:Kyasanur Forest disease(KFD)is a febrile illness characterized by hemorrhages,and is reported endemic in the Shimoga district in Karnataka state,*** is caused by the KFD virus(KFDV)of the family Flaviviridae,and is transmitted to monkeys and humans by Haemaphysalis ***:We investigated a new focus of KFD among tribals in a reserve forest in Kerala state,India.A suspected case was defined as a person presenting with acute fever,headache,or *** sera were collected and tested for KFDV RNA by real-time RT-PCR,RT-nPCR assay,and anti-KFDV IgM and IgG by *** index case was a tribal woman with febrile illness,severe myalgia,gum bleeding,and ***-KFDV IgM antibody was detected in acute and convalescent sera of the index case along with IgG in the second *** of her family members reported *** verbal autopsy,two more fatal cases were identified as probable primary *** serum from a case in the second cluster was detected positive for KFDV RNA by real time RT-PCR(Ct=32)and *** of E gene showed highest similarity of 98.0%with the KFDV W-377 isolate nucleotide and 100%identity with amino ***-KFDV IgM was detected in the serum of one family member of the index case,as well as in one out of 17 other ***:We confirmed a new focus of KFDV activity among tribals in a reserve forest in the Malappuram district of Kerala,India.

关键词： Kyasanur Forest disease Hemorrhagic fever Arbovirus Flavivirus India Ticks