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Natural Science 2012年第3期4卷 170-178页

作者： har lal singh Jangbhadur singh Department of Chemistry Faculty of Engineering & Technology Mody Institute of Technology and Science Sikar India

New dibutyltin(IV) complexes of Schiff base derived from 5-chloroindoline-2,3-dione, indoline- 2,3-dione with amino acids (tryptophan, alanine and valine) were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, and biological activity. The analytical data showed that the Schiff base ligand acts as bidentate towards metal ions via the azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of M:L (1:2) to form metal complexes. NMR (1H, 13C and 119Sn) spectral data of the ligands and metal complex agree with proposed structures. The conductivity values between 14 - 27 ohm-1cm2mol-1 in DMF imply the presence of non-electrolyte species. 3D molecular modeling and analysis of bond lengths and bond angles have also been conducted for a representative compound, [Bu2Sn(L2)2], to substantiate the proposed structures. Antibacterial results indicate that the metal complexes are more active than the free ligands.

关键词： Schiff Base Isatins Amino Acids Dibutyltin (IV) Complexes Spectral Studies Antimicrobial Activity

Synthesis, spectral, 3D molecular modeling and antibacterial studies of dibutyltin (IV) Schiff base complexes derived from substituted isatin and amino acids

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Performance evaluation of nanofluid-based minimum quantity lubrication grinding of Ni-Cr alloy under the influence of CuO nanoparticles

Natural Science 2012年第3期

作者： har lal singh Jangbhadur singh

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Advances in Manufacturing 2021年第4期9卷 580-591页

作者： Roshan lal Virdi Sukhpal singh Chatha Hazoor singh Department of Mechanical Engineering Punjabi UniversityPatialaIndia Yadavindra College of Engineering Guru Kashi Punjabi University CampusTalwandi SaboIndia

In machining processes,researchers are actively engaged in exploring minimum quantity lubrication(MQL)as a possible alternative to traditional flood cooling owing to economic and ecological *** search for ecologically safe lubricants has attracted the attention of scientists looking to use vegetable oil as a *** nanofluid MQL technique with biodegradable oils as the base is a relatively new method with the potential to replace mineral *** the present study,the grinding of Inconel-718 alloy was investigated using nanofluid MQL(NFMQL)with biodegradable oils as the *** are composed by dispersing 0.5%(mass fraction)and 1%(mass fraction)of CuO nanoparticles in vegetable *** surface morphology,G-ratio,forces,and grinding energy were examined under pure MQL,NFMQL,and dry and flood lubrication *** experimental results indicated that the nanofluid MQL significantly improved the machining *** to the polishing and rolling effect of nanoparticles on the tool work interface,a surface finish under a 0.5%(mass fraction)nanofluid was found to be better than pure MQL-dry and flood lubrication *** NFMQL technique with 1%(mass fraction)CuO nanoparticles with palm oil as the base helped in achieving a better evacuation of chips from the grinding zone,leading to a better surface finish with a high material removal rate along with less energy consumption compared to flood and dry grinding.

关键词： Minimum quantity lubrication(MQL) Nanoparticles Grinding Vegetable oils Inconel-718 alloy

User Assisted Cooperative Relaying in Beamspace Massive MIMO NOMA Based Systems for Millimeter Wave Communications

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China Communications 2019年第6期16卷 103-113页

作者： Jaipreet Kaur Maninder lal singh Department of Electronics Technology Guru Nanak Dev University

A novel scheme‘user assisted cooperative relaying in beamspace massive multiple input multiple output(M-MIMO)non-orthogonal multiple access(NOMA)system’has been proposed to improve coverage area,spectrum and energy efficiency for millimeter wave(mmWave)communications.A downlink system for M users,where base station(BS)is equipped with beamforming lens antenna structure having NRF radio frequency(RF)chains,has been considered.A dynamic cluster of users is formed within a beam and the intermediate users(in that cluster)between beam source and destination(user)act as relaying *** the use of successive interference cancellation(SIC)technique of NOMA within a cluster,the relaying stations relay the symbols with improved power to the *** maximizing achievable sum rate,transmit precoding and dynamic power allocation for both intra and inter beam power optimization are *** for performance evaluation are carried out to validate that the proposed system outperforms the conventional beamspace M-MIMO NOMA system for mmWave communications in terms of spectrum and energy efficiency.

关键词： cooperative relaying system(CRS) millimeter wave(mmWave) massive multiple input multiple output(M-MIMO) non-orthogonal multiple access(NOMA) power allocation sum rate

Investigating the Evolution of Amati Parameters with Redshift

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Research in Astronomy and Astrophysics 2024年第1期24卷 188-200页

作者： Meghendra singh Darshan singh Kanhaiya lal Pandey Dinkar Verma Shashikant Gupta Delhi Metro Rail Corporation Limited New Delhi 110001India GD Goenka University Gurugram 122103India Department of Physics Mata Raj Kaur Institute of Engineering and TechnologyRewari 123401India Department of Physics School of Advanced SciencesVellore Institute of TechnologyVellore 632014India

Gamma-ray bursts(GRBs) are among the brightest objects in the Universe and, hence, can be observed up to a very high redshift. Properly calibrated empirical correlations between intensity and spectral correlations of GRBs can be used to estimate the cosmological parameters. However, the possibility of the evolution of GRBs with redshift is a long-standing puzzle. In this work, we used 162 long-duration GRBs to determine whether GRBs below and above a certain redshift have different properties. The GRBs are split into two groups, and we fit the Amati relation for each group separately. Our findings demonstrate that estimations of the Amati parameters for the two groups are substantially dissimilar. We perform simulations to investigate whether the selection effects could cause the difference. Our analysis shows that the differences may be either intrinsic or due to systematic errors in the data, and the selection effects are not their true origin. However, in-depth analysis with a new data set comprised of 119 long GRBs shows that intrinsic scatter may partly be responsible for such effects.

关键词： Cosmology gamma rays:general (cosmology:)large-scale structure of universe galaxies:high-redshift

Long-Term Effects of Different Passages of Vehicular Traffic on Soil Properties and Carbon Storage of a Crosby Silt Loam in USA

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Pedosphere 2019年第2期29卷 150-160页

作者： Gulab singh YADAV Rattan lal Ram Swaroop MEENA Basant RIMAL Carbon Management and Sequestration Centre the Ohio State University

The passage of vehicles with heavy axle loads causes soil compaction, and this adversely affects soil properties and crop *** adverse effects can persist for several years due to significant changes in key soil properties. However, the mechanisms of the aforementioned effects are not well understood for conservation agriculture(CA)(e.g., no-till(NT)) wherein the use of heavy machinery is considerably common. Therefore, known compaction forces(0 Mg load for compaction(NT-0, control), two passages of 2.5 Mg water wagon axle load(NT-2), and four passages of 2.5 Mg water wagon axle load(NT-4)) were applied to all the plots annually for 20 consecutive years. The experiment was established in 1997 at the Waterman Agricultural and Natural Resources Laboratory(WANRL), Ohio State University, Columbus, Ohio. Each treatment was replicated thrice. Soil samples were obtained in November2016 to determine the effects of variations in the axle load and vehicular passages on carbon(C) and nitrogen(N) storage and selected soil properties of a Crosby silt loam soil under NT-based corn-soybean rotation with residue retention in Central Ohio, USA. Three locations were also randomly selected in an adjoining natural woodlot(WL) soil plot and sampled(30 m away from the compaction field) to compare the effects of vehicular traffic on soil under NT with WL soil. Results revealed that soil bulk density(ρb) and total porosity at 0–10 and 10–20 cm depths were not affected by the passages of vehicular traffic for 20 years under the NT *** penetration resistance(PR)(1.86 and 2.03 MPa at 0–10 and 10–20 cm soil depths, respectively) was significantly higher under NT-4 compared with that under other treatments. Saturated hydraulic conductivity at 0–10 and 10–20 cm soil depths ranged from19.7 to 31.4 and 18.5 to 29.5 mm d^(-1), respectively, across all the treatments. The proportion of macroaggregates(> 0.25 mm) and microaggregates(< 0.25 mm), mean weight diameter and geometric mean diam

关键词： carbon stock heavy machinery no-till residue retention soil aggregates soil compaction soil quality well-drained soil

Diversity,Distribution and Prioritization of Fodder Species for Conservation in Kullu District,Northwestern Himalaya,India

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Journal of Mountain Science 2007年第3期4卷 259-274页

作者： S. S. Samant Man singh Manohar lal Shreekar Pant G.B.Pant Institute of Himalayan Environment & Development Himachal UnitMohal-Kullu175 126Himachal PradeshIndia

In the Indian Himalayan Region predominantly rural in character, livestock is one of the main sources of livelihood and integral part of the economy. Livestock mostly rely on fodder from wild. The diversity, distribution, utilization pattern, nativity, endemism, rarity, seasonality of availability, nutritive values, perceived economic values and pressure use index of livestock have not been studied. The present study attempts to enumerate 150 species of fodder representing trees (51 spp.), shrubs (54 spp.) and herbs (45 spp.). Poaceae (19 spp.) and Fabaceae (13 spp.) amongst families and Salix (6 spp.), Ficus, Clematis, and Desmodium (5 spp., each) amongst genera are rich in species. Maximum species were found in the 1801 ~ 2600 m zone, and the remaining two zones showed relatively low diversity. Out of the 150 species, 109 are used in summer, 5 winter and 36 throughout year. During rainy season, mostly grasses are used as fodder. Only 83 species are native to the Himalayan region, one species, Strobilanthus atropuroureus is endemic and 35 species are near endemic. The nutritive values of the fodder species were reviewed, and economic values and status of the species were also assessed. The pressure use index of the species was calculated on the basis of cumulative values of the utilization pattern, altitudinal distribution, availability, status, nativity and endemism. Amongst the species, Grewia oppositifoilia, Morus serrata, Indigofera heterantha, Quercus leucotrichphora, Ulmus villosa, U. wallichiana and Aesculus indica showed highest PUI indicating high preference and pressure. Season wise prioritization of the species for different altitudinal zones has been done. Appropriate strategy and action plan have been suggested for the conservation and management of fodder species.

关键词： Diversity utilization native endemic nutritive and economic value pressure use index prioritization conservation Indian Himalayan Region

Investigation of rockfall-prone road cut slope near Lengpui Airport,Mizoram,India

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第1期11卷 146-158页

作者： A.K.Verma Sahil Sardana Pushpendra Sharma lal Dinpuia T.N.singh Department of Mining Engineering Indian Institute of Technology (Banaras Hindu Universiy) Department of Mining Engineering Indian Institute of Technology (Indian School of Mines) Department of Civil Engineering Lassonde School of Engineering York University Department of Ceology Pachhunga University College Department of Earth Sciences Indian Institute of Technology Bombay

Rockfall is one of severe natural hazards that are frequently reported in northeast region of India. It carries rock block falling from the cliff with high velocities and energies which can result in damages to vehicles, disruption to transportation, injuries and fatalities. The massive rockfall event which occurred in April 2017 on the highway NH-44 A, near Lengpui Airport, blocked the traffic for 1 d, and fortunately,no casualties were reported as the event occurred in the night. This is the only highway connecting the Aizawl city to the airport and the region is highly prone to rockfall events. Hence assessment of rockfall along this highway is necessary. In the current study, rockfall hazard assessment has been carried out on three locations by rockfall hazard rating system(RHRS). During pre-failure analysis, the result shows that most hazardous slopes have RHRS score of 639. The slopes were found to be vulnerable and later on the rockfall activity occurred. Three-dimensional(3 D) stability analysis has been carried out using 3 DEC software package to analyze the failure behavior and to decide the rockfall-prone zone(unstable blocks)for slope. The total displacement of 2.24 cm and velocity of 2,25 mm/s of the failed block have been observed in the numerical analysis. Further, the rockfall vulnerable zone(unstable blocks) is considered to determine the parameters such as run-out distance, bounce height and energies of the falling rock blocks. The maximum total kinetic energy of 5047 kJ has been observed in the numerical analysis with the maximum run-out distance up to 18 m.

关键词： Rockfall hazards Rockfall simulation Rockfall hazard rating system(RHRS) Road cut slopes Slope stability

Plant Species Diversity along an Altitudinal Gradient of Bhabha Valley in Western Himalaya

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Journal of Mountain Science 2008年第2期5卷 157-177页

作者： Amit Chawla S.Rajkumar K.N.singh Brij lal R.D.singh A.K.Thukral Bioresource Development Unit Institute of Himalayan Bioresource Technology (CSIR) Palampur Himachal Pradesh-176 061 India Department of Botanical & Environmental Sciences Guru Nanak Dev University Amritsar-143 005 India

The present study highlights the rich species diversity of higher plants in the Bhabha Valley of western Himalaya in India. The analysis of species diversity revealed that a total of 313 species of higher plants inhabit the valley with a characteristic of moist alpine shrub vegetation. The herbaceous life forms dominate and increase with increasing altitude. The major representations are from the families Asteraceae, Rosaceae, Lamiaceae and Poaceae, suggesting thereby the alpine meadow nature of the study area. The effect of altitude on species diversity displays a hump-shaped curve which may be attributed to increase in habitat diversity at the median ranges and relatively less habitat diversity at higher altitudes. The anthropogenic pressure at lower altitudes results in low plant diversity towards the bottom of the valley with most of the species being exotic in nature. Though the plant diversity is less at higher altitudinal ranges, the uniqueness is relatively high with high species replacement rates. More than 90 % of variability in the species diversity could be explained using appropriate quantitative and statistical analysis along the altitudinal gradient. The valley harbours 18 threatened and 41 endemic species, most of which occur at higher altitudinal gradients due to habitat specificity.

关键词： Plant species diversity threatened species altitudinal gradient flora Bhabha Valley western Himalaya India

Species Diversity and Population Status of Threatened Plants in Different Landscape Elements of the Rohtang Pass,Western Himalaya

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Journal of Mountain Science 2008年第1期5卷 73-83页

作者： K.N.singh Gopichand Amit Kumar Brij lal N.P.Todaria Biodiversity Division Institute of Himalayan Bioresource Technology (CSIR)PalampurHimachal Pradesh176 061India Forestry department HNB Garhwal UniversitySrinagarUttarakhandIndia

This paper highlights the quantitative estimates of plant species diversity and ecosystems of the Rohtang Pass,which is one of the most preferred visiting spots by tourists in Himachal Pradesh (H.P.),India. In spite of high pressure of anthropogenic activities,the Rohtang Pass still harbours a variety of flowering plants with economic value,including various medicinal herbs. In order to observe species diversity in different landscape elements (LSEs),ground surveys were conducted in nine unique LSEs within the elevation range between 3624 m and 4332 m. Plant community structure in each LSE was studied using stratified random sampling where a total 56 quadrats of 1 m2 in size for herbs and 7 quadrats of 25 m2 for shrubs were made. Of the total 50 plant species belonging to 15 families recorded in different random quadrats,24 species were found of medicinal value. Maximum species richness (18) and value of Shannon diversity (H'=2.2648) were observed on northeast-facing slope in Picrorhiza kurrooa dominated LSE in moist area,followed by Rheum emodi LSE (species richness = 17 and H' = 2.4141) distributed on south-facing slope. Maximum values of species richness and Shannon diversity in Rheum emodi LSE were observed between 8 ～ 12 and 1.4797 ～ 2.1911,respectively. Rhododendron anthopogon dominated LSE on northwest-facing slope was found least diverse in terms of species richness where the Simpson index of dominance (D) was 0.4205. The species were equal in abundance in P. kurrooa LSE on east-facing slope and Pleurospermum candollii LSE on north-facing slope,showing the maximum similarity in terms of species distribution between the two LSEs. Low turnover of species across common LSEs gives an idea regarding their limited distribution. Five species of threatened category according to the IUCN criteria were observed in seven LSEs. The largest population of threatened medicinal plants was recorded on northeast and northwest-facing slopes where population density of Bergenia

关键词： Species diversity threatened plant landscape Rohtang Pass western Himalaya