http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Research Trends of Coronavirus: Bibliometric Analysis from 1989-2019
Shiv Singh,Sanjay Kataria,Tulika Dey 건국대학교 GLOCAL(글로컬)캠퍼스 지식콘텐츠연구소 2021 International Journal of Knowledge Content Develop Vol.11 No.4
The world is going through the most unprecedented time with the outbreak of novel Coronavirus disease (COVID-19), which has become a threat to millions. A Coronavirus is a group of viruses that cause a variety of diseases in mammals and birds leading to a range of illnesses in humans including common cold and more severe forms like severe acute respiratory syndrome Coronavirus (SARS-CoV), Middle East respiratory syndrome Coronavirus (MERS-CoV) and COVID-19, which are life-threatening. The virus gets its name from its shape which takes the form of a crown with protrusions around it. In December 2019, a pneumonia outbreak was reported in the Wuhan City of China, which was later traced to a novel strain of Coronavirus and termed as Novel COVID-19. It typically causes flu-like symptoms including fever, cough and shortness of breath and is transmitted through human-to-human and there is no cure for it till now. Thus, this bibliometric study has been carried out to analyze the research progress in Coronavirus and literature published during a period of 30 years (1989-2019). Data for the study were fetched from Web of Science(WoS) multidisciplinary database and the publication trends in terms of total articles, productive countries, institutions, journals, productive authors, most cited articles and authors, etc have been analyzed. In total, 4917 articles were retrieved; these were from 711 sources and were contributed by 14442 authors. The collaboration index was 3.11, which clearly indicates that there has been a lot of collaboration in this field. The most preferred journal for the study period was “Journal of Virology” and the maximum contribution has been from the University of Hong Kong.
Transversal lightlike submersions from indefinite Sasakian manifolds onto lightlike manifolds
Shiv Sharma Shukla,Vipul Singh 대한수학회 2023 대한수학회논문집 Vol.38 No.4
In this paper, we introduce and study two new classes of lightlike submersions, called radical transversal and transversal lightlike submersions between an indefinite Sasakian manifold and a lightlike manifold. We give examples and investigate the geometry of distributions involved in the definitions of these lightlike submersions. We also study radical transversal and transversal lightlike submersions from an indefinite Sasakian manifold onto a lightlike manifold with totally contact umbilical fibers.
Umrao, Sima,Gupta, Tejendra K.,Kumar, Shiv,Singh, Vijay K.,Sultania, Manish K.,Jung, Jung Hwan,Oh, Il-Kwon,Srivastava, Anchal American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.35
<P>The electromagnetic interference (EMI) shielding of reduced graphene oxide (MRG), B-doped MRG (BMRG), N-doped MRG (N-MRG), and B-N co-doped MRG (B-N-MRG) have been studied in the Ku-band frequency range (12.8-18 GHz). We have developed a green, fast, and cost-effective microwave assisted route for synthesis of doped MRG. B-N-MRG shows high electrical conductivity in comparison to MRG, B-MRG and N-MRG, which results better electromagnetic interference (EMI) shielding ability. The co-doping of B and N significantly enhances the electrical conductivity of MRG from 21.4 to 124.4 Sm-1 because N introduces electrons and B provides holes in the system and may form a nanojunction inside the material. Their temperature-dependent electrical conductivity follows 2D-variable range hopping (2D-VRH) and Efros-Shldovskii-VRH (ES-VRH) conduction model in a low temperature range (T < 50 K). The spatial configuration of MRG after doping of B and N enhances the space charge polarization, natural resonance, dielectric polarization, and trapping of EM waves by internal reflection leading to a high EMI shielding of -42 dB (-99.99% attenuation) compared to undoped MR.G (-28 dB) at a critical thickness of 1.2 mm. Results suggest that the B-N-MRG has great potential as a candidate for a new type of EMI shielding material useful in aircraft, defense industries, communication systems, and stealth technology.</P>
Naik B Naveen,Manoj Kumar Jaiswal,Venkata Ganesh,Ajay Singh,Shyam Charan Meena,Vamsidhar Amburu,Shiv Lal Soni 대한치과마취과학회 2022 Journal of Dental Anesthesia and Pain Medicine Vol.22 No.5
Background: Low-dose dexmedetomidine may be a suitable alternative to opioids for pediatric ambulatory procedures under general anesthesia (GA). However, the recovery profile remains unclear. Herein, we aimed to evaluate the effects of low-dose dexmedetomidine on the recovery profile of children. Methods: Seventy-two children undergoing ambulatory oral rehabilitation under GA were randomly and equally distributed into two groups (D and F). Group D received an infusion of dexmedetomidine 0.25 μg/kg for 4 min for induction, followed by maintenance of 0.4 μg/kg/h. Group F received an infusion of fentanyl 1 μg/kg over 4 min for induction, followed by maintenance at 1 μg/kg/h. The primary outcome was the extubation time. The secondary outcomes were awakening time, end-tidal sevoflurane (ET-Sevo) requirement, change in hemodynamic parameters, Richmond Agitation–Sedation Scale (RASS), Children's Hospital of Eastern Ontario pain scale (CHEOPS) score, length of PACU stay, and incidence of adverse events. Results: Statistically significant differences were observed in the recovery profile between the groups: the median time for extubation was 3.65 (3.44–6.2) vs. 6.25 (4.21–7) minutes in groups D vs. F (P=0.001), respectively, while the corresponding awakening times were 19 (18.75–21) and 22.5 (22–24) minutes, respectively (P < 0.001). The mean ET-Sevo was low in group D (1.1 vs. 1.2; P < 0.001). The heart rate was significantly low across all time points in group D, without resulting in bradycardia. The median RASS and CHEOPS scores were also significantly lower in group D. No significant differences were observed in the mean arterial pressure, incidence of adverse events, or length of PACU stay. Conclusion: Low-dose dexmedetomidine was more effective than fentanyl as an opioid substitute at providing a better recovery profile in pediatric ambulatory oral rehabilitation under GA. Dexmedetomidine also significantly reduced sevoflurane consumption without causing adverse events or prolonging hospital stay.
Asisa Kumar Panigrahi,Tamal Ghosh,C. Hemanth Kumar,Shiv Govind Singh,Siva Rama Krishna Vanjari 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.3
Diffusion of atoms across the boundary between two bonding layers is the key for achieving excellent thermocompressionWafer on Wafer bonding. In this paper, we demonstrate a novel mechanism to increase the diffusion across the bondinginterface and also shows the CMOS in-line process flow compatible Sub 100 °C Cu–Cu bonding which is devoid of Cusurface treatment prior to bonding. The stress in sputtered Cu thin films was engineered by adjusting the Argon in-let pressurein such a way that one film had a compressive stress while the other film had tensile stress. Due to this stress gradient, anominal pressure (2 kN) and temperature (75 °C) was enough to achieve a good quality thermocompression bonding havinga bond strength of 149 MPa and very low specific contact resistance of 1.5 × 10−8 Ω-cm2. These excellent mechanical andelectrical properties are resultant of a high quality Cu–Cu bonding having grain growth between the Cu films across theboundary and extended throughout the bonded region as revealed by Cross-sectional Transmission Electron Microscopy. Inaddition, reliability assessment of Cu–Cu bonding with stress engineering was demonstrated using multiple current stressingand temperature cycling test, suggests excellent reliable bonding without electrical performance degradation.
Changes in Inorganic Chemical Species in Fog Water over Delhi
Umesh Chandra Dumka,Suresh Tiwari,Rahul Sheoran,Hulivahana Nagaraju Sowmya,Deewan Singh Bisht,Atul Kumar Srivastava,Shiv Dev Attri,Philip Karl Hopke 한국대기환경학회 2022 Asian Journal of Atmospheric Environment (AJAE) Vol.16 No.2
Heavy fogs occur during the winter period over the part of northern India and impact aviation, public transport, the economy, public life, etc. During winter, fog water (FW) and non-monsoonal rainwater (NMRW) samples were collected in Delhi, which is a highly polluted and populated megacity in northern India. The collected FW and NMRW samples were analyzed for their inorganic chemical constituents (F-, Cl-, SO4 2-, NO3 -, NH4 +, Na+, K+, Ca2+, and Mg2+). The volume-weighted mean (VWM) pH, conductivity, and total dissolved solids (TDS) of FW were 6.89, 206 μS cm-1, and 107 mg L-1, respectively, indicating the dominance of alkaline species. The total measured ionic constituents (TMIC) in FW and NMRW were 5,738 and 814 μeq L-1, respectively, indicating highly concentrated FW in Delhi. The TMIC in FW were factors of 16 and 7 times more concentrated than MRW and NMRW samples, respectively. The concentrations of inorganic acidic species (SO4 2- and NO3 -) in FW were much higher than in monsoon rainwater (MRW: 3 and 5 times) and NMRW (8 and 12 times), respectively. Also, the concentrations of SO4 2- and NO3 in NMRW were approximately double compared to MRW indicating higher acidic species concentrations during the winter season over Delhi region. Significant decadal growth in the mean concentrations of ionic species in FW (SO4 2- - ~9 times; NH4 + - double) were observed between 1985 and 2010. However, the nitrate decreased by ~28%. The higher SO4 2- is likely from heavy-duty vehicles that burn sulfur-containing fuel. The anions in FW, MRW, and NMRW contributed 20, 42, and 43%. However, the cation contributions were 80, 58, and 57%, respectively. The anion contributions were lower in FW than MRW and NMRW indicating the weak formation of acidic species in fog water. The observed alkalinity suggests that it is unlikely for acid precipitation to be present in this region.
Electroless Amorphous NiP Coatings Over API X70 Steel: Resistance to Wear and Hydrogen Embrittlement
Santigopal Samanta,K. Vishwanath,K. Mondal,Monojit Dutta,Shiv Brat Singh 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2
The present work discusses very good resistance to hydrogen embrittlement as well as wear resistance of NiP coated API(American Petroleum Institute) X70 steel as compared to the bare steel and electrolytic crystalline Ni coated steel. The NiPcoatings with three compositions (hypo, hyper and near-eutectic compositions), prepared by an electroless technique, werepredominantly amorphous. The relative wear behavior of the coatings was studied using ball-on disc tests in air. The hydrogenembrittlement susceptibility (HES) was assessed using slow strain rate tensile (SSRT) tests after cathodic hydrogen chargingof the coated as well as bare steel. The superior wear resistance of the NiP coated steels showed abrasive wear, whereas theNi-coated steel showed adhesive wear. Hyper and hypo-eutectic NiP coated steels showed a comparatively lower H-inducedembrittlement than the uncoated and Ni-electroplated steels and these could be attributed to the excellent hydrogen barrierproperty of the NiP coatings.