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Study of plasma parameters of coaxial plasma source using triple Langmuir probe and Faraday cup diagnostics

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Plasma Science and Technology 2024年第4期26卷 94-100页

作者： sunil kANCHI Rohit SHUkLA Archana sharma Pulsed Power and Electromagnetics Division Bhabha Atomic Research CentreVisakhapatnam 531011India Homi Bhabha National Institute Mumbai 400085India Beam Technology Development Group Bhabha Atomic Research CentreMumbai 400085India

Coaxial plasma guns are a type of plasma source that produces plasma which propagates radially and axially controlled by the shape of the ground electrode, which has attracted much interest in several applications. In this work, a 120° opening angle of CPG nozzle is used as a plasma gun configuration that operates at the energy of 150 J. The ionization of polyethylene insulator between the electrodes of the gun produces a cloud of hydrogen and carbon *** triple Langmuir probe and Faraday cup are used to measure plasma density and plasma temperature. These methods are used to measure the on-axis and off-axis plasma divergence of the coaxial plasma gun. The peak values of ion densities measured at a distance of 25 mm on-axis from the plasma gun are(1.6±0.5)×10^(19)m^(-3)and(2.8±0.6)×10^(19)m^(-3)for hydrogen and carbon plasma respectively and the peak temperature is 3.02±0.5 eV. The mean propagation velocity of plasma is calculated using the transit times of plasma at different distances from the plasma gun and is found to be 4.54±0.25 cm/μs and 1.81±0.18 cm/μs for hydrogen and carbon plasma respectively. The Debye radius is obtained from the measured experimental data that satisfies the thin sheath approximation. The shot-to-shot stability of plasma parameters facilitates the use of plasma guns in laboratory experiments. These types of plasma sources can be used in many applications like plasma opening switches, plasma devices, and as plasma sources.

关键词： coaxial plasma source triple Langmuir probe Faraday cup plasma density plasma temperature

Structural characterization of carboxyl cellulose nanofibers extracted from underutilized sources

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Science China(Technological Sciences) 2019年第6期62卷 971-981页

作者： ZHAN ChengBo sharma Priyanka R. GENG LiHong sharma sunil k. WANG RuiFu JOSHI Ritika HSIAO Benjamin S. Department of Chemistry Stony Brook University Stony Brook NY 11794-3400 USA National Engineer Research Center of Novel Equipment for Polymer Processing Key Laboratory of Polymer Processing Engineering of Ministry of Education South China University of Technology Guangzhou 510640 China

Two different chemical methods, TEMPO-oxidation and nitro-oxidation, were used to extract carboxyl cellulose nanofibers(CNFs) from non-wood biomass sources(i.e., jute, soft and hard spinifex grasses). The combined TEMPO-oxidation and homogenization approach was very efficient to produce CNFs from the cellulose component of biomass;however, the nitrooxidation method was also found to be effective to extract CNFs directly from raw biomass even without mechanical *** effect of these two methods on the resulting cross-section dimensions of CNFs was investigated by solution small-angle Xray scattering(SAXS), transmission electron microscopy(TEM) and atomic force microscopy(AFM). The UV-Vis spectroscopic data from 0.1 wt% TEMPO-oxidized nanofiber(TOCNF) and nitro-oxidized nanofiber(NOCNF) suspensions showed that TOCNF had the highest transparency(> 95%) because of better dispersion, resulted from the highest carboxylate content(1.2 mmol/g). The consistent scattering and microscopic results indicated that TOCNFs from jute and spinifex grasses possessed rectangular cross-sections, while NOCNFs exhibited near square cross-sections. This study revealed that different oxidation methods can result in different degrees of biomass exfoliation and different CNF morphology.

关键词： cellulose nanofibers TEMPO-oxidation nitro-oxidation SAXS microscopy jute spinifex

Multilayer Self-Defense System to Protect Enterprise Cloud

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Computers, Materials & Continua 2021年第1期66卷 71-85页

作者： Shailendra Mishra sunil kumar sharma Majed A.Alowaidi College of Computer and Information Sciences Majmaah UniversityMajmaah11952Saudi Arabia

A data breach can seriously impact organizational intellectual property,resources,time,and product *** risk of system intrusion is augmented by the intrinsic openness of commonly utilized technologies like TCP/IP *** TCP relies on IP addresses,an attacker may easily trace the IP address of the *** that many organizations run the risk of data breach and cyber-attacks at a certain point,a repeatable and well-developed incident response framework is critical to shield *** cloud possesses the challenges of security,lack of transparency,trust and loss of *** eases quickens the processing of information but holds numerous risks including hacking and confidentiality *** risk increases when the organization outsources the cloud storage services through the vendor and suffers from security breaches and need to create security systems to prevent data networks from being *** business model also leads to insecurity issues which derail its *** attack mitigation system is the best solution to protect online services from emerging *** research focuses on cloud computing security,cyber threats,machine learning-based attack detection,and mitigation *** proposed SDN-based multilayer machine learning-based self-defense system effectively detects and mitigates the cyber-attack and protects cloud-based enterprise *** results show the accuracy of the proposed machine learning techniques and the effectiveness of attack detection and the mitigation system.

关键词： Cybersecurity cyber threats cyber-attacks attack mitigation system

Neglected scrub typhus:An updated review with a focus on omics technologies

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Asian Pacific Journal of Tropical Medicine 2022年第12期15卷 531-541页

作者： Dixit sharma Ankita sharma Birbal Singh sunil kumar Shailender kumar Verma Centre for Computational Biology and Bioinformatics School of Life SciencesCentral University of Himachal PradeshKangra 176206India Department of Animal Science School of Life SciencesCentral University of Himachal PradeshKangra 176206India ICAR-Indian Veterinary Research Institute Regional StationPalampur 176061India

Scrub typhus is a neglected disease and one of the most serious health problems in the Asia-Pacific *** disease is caused by an obligate intracellular bacteria Orientia tsutsugamushi,which is transmitted by chigger bites or larval mite *** typhus is a threat to billions of people worldwide causing different health complications and acute encephalitis in infants and growing *** disease causes multiple organ failure and mortality rates may reach up to 70%due to a lack of appropriate *** available genome and proteome databases,and bioinformatics methods are valuable tools to develop novel therapeutics to curb the *** review discusses the state-of-the-art of information about Orientia tsutsugamushi-mediated scrub typhus and delineates the role of omics technologies to develop drugs against the *** role of proteome-wide in silico approaches for the identification of therapeutic targets is also highlighted.

关键词： Orientia tsutsugamushi Scrub typhus Therapeutic targets Omics technologies Drug discovery

Nonlinear Time Series Analysis of Pathogenesis of COVID-19 Pandemic Spreadin Saudi Arabia

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Computers, Materials & Continua 2021年第1期66卷 805-825页

作者： sunil kumar sharma Shivam Bhardwaj Rashmi Bhardwaj Majed Alowaidi College of Computer and Information Sciences Majmaah UniversityMajmaah11952Saudi Arabia Maharaja Agrasen Institute of Technology Guru Gobind Singh Indraprastha UniversityDelhi110086India Non-Linear Dynamics Research Laboratory GGS Indraprastha UniversityDelhi110078India

This article discusses short–term forecasting of the novel Corona Virus(COVID-19)data for infected and recovered cases using the ARIMA method for Saudi *** COVID-19 data was obtained from the Worldometer and MOH(Ministry of Health,Saudi Arabia).The data was analyzed for the period from March 2,2020(the first case reported)to June 15,*** ARIMA(2,1,0),we obtained the short forecast up to July 02,*** statistical parameters were tested for the goodness of fit to evaluate the forecasting *** results show that ARIMA(2,1,0)gave a better forecast for the data *** 19 data followed quadratic behavior,and in the long run,it spreads with a high *** is concluded that COVID-19 will follow secondary shock waves,and it is strongly advisable to maintain social distancing with all safety measures as the pandemic situation is not in control.

关键词： COVID-19 short-term forecast ARIMA GIS

Spatial distribution of fossil fuel derived CO_(2) over India using radiocarbon measurements in crop plants

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Journal of Environmental Sciences 2023年第2期124卷 19-30页

作者： Rajveer sharma Ravi kumar kunchala sunil Ojha Pankaj kumar Satinath Gargari Sundeep Chopra Inter University Accelerator Centre New Delhi 110067India Centre for Atmospheric Sciences Indian Institute of Technology DelhiNew Delhi 110016India

Examining the contribution of fossil fuel CO_(2) to the total CO_(2) changes in the atmosphere is of primary concern due to its alarming levels of fossil fuel emissions over the globe,specifically developing *** radiocarbon represents an important observational constraint and utilized to trace fossil fuel derived CO_(2)(CO_(2ff))in the *** the first time,we have presented a detailed analysis on the spatial distribution of fossil fuel derived CO_(2)(CO_(2ff))over India using radiocarbon(Δ14C)measurements during three-year *** shows that theΔ14C values are varying between 29.33‰ to-34.06‰ across India in the year 2017,where highest value belongs to a location from Gujarat while lowest value belongs to a location from *** on the14C patterns,spatial distributions of CO_(2ff) mole fractions have been determined over India and the calculated values of CO_(2ff) mole fractions are varying between 4.85 ppm to 26.59 ppm across *** is also noticed that the highest CO_(2ff) mole fraction is observed as 26.59 ppm from a site in ***_(2ff) mole fraction values from four high altitude sites are found to be varied between 4.85 ppm to 14.87 *** of sampling different crop plants from the same growing season and different crop plant organs(grains,leaves,stems)on theΔ14C and CO_(2ff) have been *** and intra seasonal variations in theΔ14C and CO_(2ff) mole fractions have also been analyzed from a rural location(Dholpur,Rajasthan).

关键词： Carbon dioxide Crop plants Fossil fuel CO_(2) Radiocarbon measurements

In vitro evaluation of antimicrobial and antioxidant activities of methanolic extract of Jasminum humile Leaves

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Asian Pacific Journal of Tropical Medicine 2011年第10期4卷 804-807页

作者： Parminder Nain Ashok kumar sunil sharma Jaspreet Nain M.M.College of Pharmacy M.M.UniversityMullana(Ambala)-133207India Department of Pharmaceutical sciences Guru Jambeshwer UniversityHisar(Haryana)-125001India

Objective:To evaluate in vitro antimicrobial and antioxidant activities of methanolic extract of Jasminum humile（***） leaves ***:Methanolic extract of *** was evaluated for its antimicrobial activity by using agar well diffusion method & their possible antioxidant assay by two complementary test systems,namely DPPH and hydrogen peroxide scavenging *** various antioxidant activities were compared to standard antioxidants such as ascorbic acid for both the ***:In the DPPH & hydrogen peroxide scavenging activity,the IC50 value of methanol extract was 70.43μg/mL & 60.79μg/mL respectively. Further,the extract showed inhibitory activity for Gram-positive and negative bacteria at different *** maximum antibacterial activity of extract was exhibited against Staphylococcus aureus（***） at concentration 50 mg/mL when compared with ciprofloxacin Conclusions:These results clearly indicate that *** is effective in scavenging free radicals and has the potential to be a powerful ***,the results obtained in the present study indicate that *** leaves extract could be considered as a potential source of natural antioxidants and that could be used as an effective source against bacterial diseases.

关键词： Jasminum humile Methanol extract Antimicrobial activity Antioxidant activity

Modelling and Analysis of Bacteria Dependent Infectious Diseases with Variable Contact Rates

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Computers, Materials & Continua 2021年第8期68卷 1859-1875页

作者： J.B.Shukla Shikha Singh Jitendra Singh sunil kumar sharma Innovative Internet University for Research Kanpur208017India P.P.N.(P.G.)College CSJM UniversityKanpur208001India College of Computer and Information Sciences Majmaah UniversityMajmaah11952Saudi Arabia

In this research,we proposed a non-linear SIS model to study the effect of variable interaction rates and non-emigrating population of the human habitat on the spread of bacteria-infected *** assumed that the growth of bacteria is logistic with an intrinsic growth rate is a linear function of *** this model,we assume that contact rates between susceptibles and infectives as well as between susceptibles and bacteria depend on the density of the non-emigrating population and the total population of the *** stability theory has been analyzed to analyzed to study the crucial role played by bacteria in the increased spread of an infectious *** is shown that as the density of non-emigrating population increases,the spread of an infectious disease *** is shown further that as the emigration increases,the spread of the disease decreases in both the cases of contact mentioned above rates,but this spread increases as these contact rates *** suggested that the control of bacteria in the human habitat is very useful to decrease the spread of an infectious *** results are confirmed by numerical simulation.

关键词： Mathematical modelling density dependent contact rates stability analysis

Composition and diversity of five major forest types in moist temperate climate of the western Himalayas

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Forestry Studies in China 2011年第2期13卷 139-153页

作者： Sumeet GAIROLA Chandra M. sharma Sarvesh SUYAL sunil k. GHILDIYAL Department of Botany Post Box No. 51 HNB Garhwal University

The present study was undertaken in five major forest types （dominated by Quercus semecarpifolia, Quercusfloribunda, Acer acuminatum, Abiespindrow and Aesculus indica, respectively） between 2400 and 2850 m a.s.1, in a moist temperate forest of the Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim was to assess the variation in composition and diversity in different vegetation layers, i.e., herb, shrub and tree, among these five forest types. Diversity indices, such as the Shannon-Wiener diversity index, density, total basal cover, Simpson＇s concentration of dominance index, Simpson＇s diversity index, Pielou＇s equitability, species richness, species heterogeneity and r-diversity, were calculated to understand community structures. Dominance-diversity curves were drawn to ascertain resource apportionment among various species in different forest types.

关键词： density diversity elevation fl-diversity dominance-diversity curves Garhwal Himalayas