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Phenol in High-mass Star-forming Regions

Research in Astronomy and Astrophysics 2022年第6期22卷 256-268页

作者： Rana Ghosh Milan Sil Suman kumar Mondal Prasanta Gorai Dipen Sahu rahul kumar kushwaha Bhalamurugan Sivaraman Ankan Das Indian Centre for Space Physics 43 ChalantikaGaria Station RoadKolkata 700084India S.N.Bose National Centre for Basic Sciences Salt LakeKolkata 700106India Department of Space Earth&EnvironmentChalmers University of TechnologySE-41296 GothenburgSweden Institute of Astronomy and Astrophysics Academia Sinica Taipei Taipei 10617China Atomic and Molecular Physics Laboratory Institute for Nuclear Research(Atomki)Debrecen H-4026Hungary Physical Research Laboratory NavrangpuraAhmedabad 380009India

Phenol,which belongs to the C_(6)H_(6)O isomeric group,is the simplest molecule in the family of alcohol of the aromatic *** phenol has yet to be detected in the interstellar medium,a tentative identification was reported toward the Orion KL hot core using the IRAM-30 m line *** explore some more species of this isomeric group,we consider ten species to study the fate of their astronomical *** is noticed that phenol is the most energetically favorable isomer of this *** contrast,propargyl ether is the least favorable(having relative energy~103kcal mol^(-1)compared to phenol)species of this *** far,the studies associated with the formation of phenol are heavily concentrated on combustion ***,we suggest a few key reactions(C_(6)H_(6)+OH→C_(6)H_(5)+H_(2)O,C_(6)H_(6)+O→C_(6)H_(5)OH,C_(6)H_(6)+H→C_(6)H_(5)+H_(2),and C_(6)H_(5)+OH→C_(6)H_(5)OH+hν)for the formation of *** these pathways are included in a large gas-grain chemical network to study its formation in high mass star-forming regions and dark cloud *** is noticed that the phenyl(-C_(6)H_(5))formation by the ice-phase hydrogen abstraction reaction of benzene(i.e.,C_(6)H_(6)+OH→C_(6)H_(5)+H_(2)O if allowed at~10 K)could serve as the starting point for the formation of phenol in the gas phase by radiative association reaction C_(6)H_(5)+OH→C_(6)H_(5)OH+hν.The gasphase reaction C_(6)H_(6)+O→C_(6)H_(5)OH significantly contributes to the formation of phenol,when the ice-phase reaction C_(6)H_(6)+OH→C_(6)H_(5)+H_(2)O is not considered at low *** 4 ALMA archival data of a hot molecular core,G10.47+0.03,are *** yields an upper limit on phenol abundance of 5.19×10^(-9).Our astrochemical model delivers an upper limit on phenol abundance of~2.20×10^(-9)in the hot molecular core,whereas its production in the dark cloud is not satisfactory.

关键词： astrochemistry-ISM abundances-ISM molecules-(ISM:)evolution

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Single-atom catalysts boosted ultrathin film sensors

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Rare Metals 2020年第10期39卷 1110-1112页

作者： rahul kumar Mahesh kumar Department of Electrical Engineering Indian Institute of Technology JodhpurJodhpur 342037India

Nowadays,demand for fast and accurate detection of toxic and flammable gases is increasing for human health safety,industrial process and environmental ***,gas sensor technology has become a requisite in our daily *** nanoscience and nanotechnology propel fabrication of a gas sensor at the miniaturization level for burgeoning Internet of things applications.

关键词： film nanotechnology gases

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Potential of roots and shoots of Napier grass for arresting soil erosion and runoff of mollisols soils of Himalayas

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International Soil and Water Conservation Research 2023年第3期11卷 538-548页

作者： Sushma Tamta Akhilesh kumar Daniel Prakash kushwaha Krishi Vigyan Kendra Khodawandpur848202BegusaraiBiharIndia Department of Soiland Water Conservation Engineering G.B.Pant University of Agriculture and TechnologyPantnagar263145India

In this study, a soil filled Hydraulic Tilting Flume (HTF) was used as a test plot under simulated rainfallconditions. This flume was flled with mollisols soils (sandy loam in texture) collected from tarai regionof Himalayas. The effects of root and shoot characteristics of Napier grass in terms of leaf area index (LAI),shoot length (SL), number of leaves (NL), number of tillers (NT), shoot biomass (SB), root density (RD),root length (RL), root biomass (RB), and total biomass (TB) were investigated on runoff and sedimentoutflow at 90, 120 and 150 days after planting (DAP). Four simulated rainfall intensities namely 4.0, 6.5,8.3 and 9.4 cm/h over three land slopes of 1, 2 and 3% were selected. Runoff samples collected fromwhole plant plot and only root plot were analyzed for runoff and sediment outflow. Findings revealedthat Napier grasses were very effective to reduce runoff and sediment outflow and its efficacy increasedwith the extended growth stages. The reduction in runoff and sediment outflow at 90, 120 and 150 DAPwas obtained as 56% and 85%, 68% and 90%, and 74% and 96%, respectively, as compared to bare plotconditions. It was observed that the comparative contribution of shoots in runoff rate reduction washigher than the roots. On the contrary, the root part of the plant showed more contribution in sedimentrate reduction as compared to the shoot part. Step wise regression was attempted for the selection ofeffective input parameters to establish authentic runoff and sediment outflow models. Power form ofmultiple non-linear regression (MNLR) showed very satisfactory results for predicting runoff and sedimentoutflow with coefficient of determination (R^(2)) as 97.4% and 99.0%, respectively, root mean squareerror (RMSE) as 38.8 cc/m^(2)/min and 0.126 g/m^(2)/min, respectively, and coefficient of efficiency (CE) as93.9% and 96.7%, respectively, during testing period.

关键词： Rootand shoot characteristics Runoff and sedimentreduction Simulated rainfall conditions Hydraulic tilting flume Step wise regression analysis

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Floristic analysis and dominance pattern of sal(Shorea robusta)forests in Ranchi,Jharkhand,eastern India

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Journal of Forestry Research 2020年第2期31卷 415-427页

作者： rahul kumar Purabi Saikia Department of Environmental Sciences Central University of JharkhandBrambeRanchi 835205JharkhandIndia

The present study describes the floristic composition and dominance pattern of sal forests in Ranchi,Jharkhand,eastern *** was studied in 47 belt transects(509100 m)that had 137 plant species(110 identified and 27 unidentified)belonging to 51 *** family Fabaceae with 17 species(8 *** to subfamily Faboideae,6 *** Caesalpinioideae and 3 *** Mimosoidieae)contributed the most to diversity,followed by Rubiaceae(8 spp.)and Euphorbiaceae(6 spp.).Tree density in sal was inversely related to species *** tree density(C 10 cm GBH)in the studied forests was 397 individuals ha-1,with a basal cover of 262.50 m2 *** plants of conservation concern are Pterocarpus marsupium Roxb,Andrographis paniculata(Burm.f.)Wall,Sterculiaurens Roxb.,Tinospora cordifolia(Willd.)Miers,and Asparagus densiflorus(Kunth)*** had the highest percentage(71%,with percentage deviation from normal life form of?25)followed by therophyte(15%,with percentage deviation?2).Observed percentage deviation from normal life form was much lower(with?2 percentage deviation)in both chamaephytes(8%)and therophytes(15%),suggesting that the studied sal forests are favorable for supporting various plants *** forest management strategies should focus on the increasing demands for different timber and non-timber forest products to conserve the plant diversity of these natural forests.

关键词： Sal forests Species richness Life form Jharkhand

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Room-Temperature Gas Sensors Under Photoactivation:From Metal Oxides to 2D Materials

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Nano-Micro Letters 2020年第11期12卷 292-328页

作者： rahul kumar Xianghong Liu Jun Zhang Mahesh kumar Department of Electrical Engineering Indian Institute of Technology JodhpurJodhpur 342037India College of Physics Center for Marine Observation and CommunicationsQingdao UniversityQingdao 266071People’s Republic of China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin 300071People’s Republic of China

Room-temperature gas sensors have aroused great attention in current gas sensor technology because of deemed demand of cheap,low power consumption and portable sensors for rapidly growing Internet of things *** an important approach,light illumination has been exploited for room-temperature operation with improving gas sensor's attributes including sensitivity,speed and *** review provides an overview of the utilization of photoactivated nanomaterials in gas sensing ***,recent advances in gas sensing of some exciting different nanostructures and hybrids of metal oxide semiconductors under light illumination are ***,excellent gas sensing performance of emerging two-dimensional materialsbased sensors under light illumination is discussed in details with proposed gas sensing *** impressive features from the interaction of photons with sensing materials are elucidated in the context of modulating sensing ***,the review concludes with key and constructive insights into current and future perspectives in the light-activated nanomaterials for optoelectronic gas sensor applications.

关键词： Gas sensor Room temperature Photoactivation Metal oxide 2D materials

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Measurement of Hubble constant: were differences in secondary distance indicators apparent as early as the HST Key Project?

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Research in Astronomy and Astrophysics 2021年第3期21卷 97-106页

作者： rahul kumar Thakur Shashikant Gupta rahul Nigam PK Thiruvikraman Birla Institute of Technology&Science Pilani-Hyderabad CampusIndia G D Goenka University GurgaonHaryana122103India

Different measurements of the Hubble constant(H_(0))are not consistent,and a tension between the CMB based methods and cosmic distance ladder based methods has been *** from various distance based methods are also *** aggravate the problem,the same cosmological probe(TypeⅠa SNe for instance)calibrated through different methods also provides different values of H_(0).We compare various distance ladder based methods through the already available unique data obtained from the Hubble Space Telescope(HST).Our analysis is based on parametric(t-test)as well as non-parametric statistical methods such as the Mann-Whitney U test and Kolmogorov-Smirnov *** results show that different methods provide different values of H_(0) and the differences are statistically *** biases in the calibration would not account for these differences as the data have been taken from a single telescope with a common calibration *** unknown physical effects or issues with the empirical relations of distance measurement from different probes could give rise to these differences.

关键词： Cosmology Supernovae Hubble constant

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Investigating the Hubble Tension Through Hubble Parameter Data

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Research in Astronomy and Astrophysics 2023年第6期23卷 199-202页

作者： rahul kumar Thakur Shashikant Gupta rahul Nigam PK Thiruvikraman Avantika University Ujjain456006India G D Goenka University GurgaonHaryana122103India Birla Institute of Technology&Science Pilani-Hyderabad CampusIndia

The Hubble constant(H_0),which represents the expansion rate of the universe,is one of the most important cosmological *** recent measurements of H0using the distance ladder methods such as type Ia supernovae are significantly greater than the CMB measurements by *** difference points to a crisis in the standard model of cosmology termed Hubble *** this work we compare different cosmological models,determine the Hubble constant and comment on the Hubble tension using the data from differential ages of *** data we use are free from systematic effects as the absolute age estimation of the galaxies is not *** apply the Bayesian approach along with the commonly used maximum likelihood method to estimate H_0 and calculate the AIC scores to compare the different cosmological *** non-flat cosmological model provides a higher value for matter density as well as the Hubble constant compared to the flatΛCDM *** AIC score is smaller for the flatΛCDM cosmology compared to the non-flat model indicating the flat model a better *** best-fit values of H_0 for both these models are 68.7±3.1 km s^(-1)Mpc^(-1)and 72.2±4km s^(-1)Mpc^(-1),*** results are consistent with the CCHP ***,the flat model result does not agree with the SH0ES result,while the non-flat result is inconsistent with the Planck value.

关键词： (cosmology:)cosmological parameters galaxies:high-redshift (stars:)supernovae:general

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Universal converse flexoelectricity in dielectric materials via varying electric field direction

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International Journal of Smart and Nano Materials 2021年第1期12卷 107-128页

作者： Saurav Sharma Rajeev kumar rahul Vaish School of Engineering Indian Institute of Technology MandiMandiIndia

Flexoelectricity is a symmetry independent electromechanical cou-pling phenomenon that outperforms piezoelectricity at micro and nanoscales due to its size-dependent behavior arising from gradi-ent terms in its constitutive ***,due to this gradient term flexoelectricity,to exhibit itself,requires specially designed geometry or material composition of the dielectric *** of its kind,the present study put forward a novel strategy of achieving electric field gradient and thereby converse flexoelectri-city,independent of geometry and material composition of the *** spatial variation of the electric field is established inside the dielectric material,Ba_(0.67)Sr_(0.33)TiO_(3)(BST),by manipulating electrical boundary *** unique patterns of electrode placement are suggested to achieve this spatial *** varying direction of electric field gives rise to electric field gradient,the prerequisite of converse flexoelectricity.A multi-physics cou-pling based theoretical framework is established to solve the flexo-electric actuation by employing isogeometric analysis(IGA).Electromechanically coupled equations of flexoelectricity are solved to obtain the electric field distribution and the resulting displace-ments *** maximum displacements of 0.2 nm and 2.36 nm are obtained with patterns I and II,respectively,while pattern III can yield up to 85 nm of maximum displacement.

关键词： Converse flexoelectricity electrical boundary conditions electric field direction isogeometric analysis

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An experimental study for optimization of high range water reducing superplasticizer in self compacting concrete

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Frontiers of Structural and Civil Engineering 2013年第1期7卷 62-71页

作者： rahul DUBEY Pardeep kumar Department of Civil Engineering National Institute of TechnologyHamirpur 177005India

Concrete is extensively used construction material in the infrastructure development *** increase in technical knowhow,the need of research for high performance concretes such as self-compacting concrete(SCC)has increased in the last *** adaptability of SCC is due to its fluidic behavior in fresh ***,to develop SCC using indigenous materials,the lack of standardized mix design procedures is the biggest *** with the advent of chemical admixtures,it is possible to achieve concrete with high fluidity,but at the same time durability issues require more *** have these fresh state properties SCC mixes are typically designed with high powder contents,and chemical *** and optimization of these materials is a key issue in the mix design of *** paper focuses mainly on experimental study to optimize dosages of superplasticizer for mortar of SCC and then in concrete mixture itself.

关键词： self-compacting concrete(SCC) fresh properties superplasticizer optimization compressive strength

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Blumgart's technique of pancreaticojejunostomy: Analysis of safety and outcomes

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Hepatobiliary & Pancreatic Diseases International 2019年第2期18卷 181-187页

作者： Vishal Gupta Saket kumar Vivek Gupta Pradeep Joshi rahul rahul Rakesh kumar Yadav Amit Dangi Abhijit Chandra Department of Surgical Gastroenterology King George's Medical University Department of Human Organ Transplant King George's Medical University

Background: Blumgart's pancreaticojejunostomy(PJ) has been described with low pancreatic leak rates. This study aimed to evaluate our experience with this technique regarding the pancreatic leak and other perioperative outcomes. Methods: We performed a single-center retrospective analysis of a cohort of 81 patients who underwent pancreaticoduodenectomy in our department from January 2011 to February 2018. The primary endpoint was the occurrence of a clinically relevant postoperative pancreatic fistula(CR-POPF) and analysis of its risk factors. Results: The CR-POPF rate was 12.3%. Fistula risk score(FRS) was the only significant risk factor for the occurrence of overall POPF in multivariate analysis. However, none of the other factors including FRS was found to be significantly associated with CR-POPF risk. A strong positive correlation was found between the CR-POPF and the incidence of delayed gastric emptying, post-pancreatectomy hemorrhage and increased length of hospital stay. Conclusion: Blumgart's technique is a safe technique of pancreatico-enteric anastomosis with low rates of CR-POPF. CR-POPF with this technique is independent of most of the preoperative and intraoperative factors. Therefore, this technique can be used for all types of the pancreas with consistently good results.

关键词： Pancreaticoduodenectomy Pancreatico-jejunal anastomosis Postoperative pancreatic fistula Pancreatic leak

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