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Phenol in High-mass Star-forming Regions

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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

Comparative studies of lightweight deflectometer and Benkelman beam deflectometer in low volume roads

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Journal of Traffic and Transportation Engineering(English Edition) 2016年第5期3卷 438-447页

作者： Sunny Deol Guzzarlapudi Vinod kumar Adigopula Rakesh kumar Department of Civil Engineering Sardar Vallabhbhai National Institute of Technology

A comparative subgrade moduli study is carried out by static and dynamic deflection methods using lightweight deflectometer and conventional Benkelman beam deflec- tometer on low volume road. Field and laboratory tests are performed at 40 test locations on in-service road of 2 km stretch that contains three common types of cohesive soils （ch, CI, and CL）. Pavement static and dynamic responses are estimated to ascertain static, backcalculated, and composite moduli of subgrade. The backcalculated and composite moduli of subgrade is validated at given moisture content using repeated triaxial test. Static moduli values are on lower side as compared with dynamic moduli values whereas the composite, and laboratory moduli of subgrade are approximately consistent with 2% to 7% variation, respectively. Correlation analyses between static and dynamic moduli of different types of subgrade soils depict good correlation of determination （R2） varies between 0.75 and 0.91. Subsequently, validation of static moduli with California bearing ratio （CBR） related subgrade moduli shows moderate correlation of 0.67 to 0.74 whereas dynamic moduli shows good correlation of 0.74 to 0.93 for different types of soils, respectively. Therefore, the comparative analysis shows that lightweight deflectometer provides reliable subgrade moduli values, and it can be used as a quick subgrade strength evaluating tool for low volume roads.

关键词： Low volume road Lightweight deflectometer Backcalculated subgrade moduli Composite moduli of subgrade Static moduli of subgrade

SYNTHESIS,chARACTERIZATION AND ELECTRICAL PROPERTIES OF Nd/Zr CO-DOPED NANO BaTiO_(3) CERAMICS

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Journal of Advanced Dielectrics 2012年第1期2卷 34-47页

作者： ch.SAMEERA DEVI M.B.SURESH G.S.kumar G.PRASAD Department of Physics Osmania University HyderabadAndhra Pradesh 500007India International Advance Research Centre for Metallurgy and New Materials BalapurHyderabad 500007India Department of Physics Osmania University HyderabadAndhra Pradesh500007India

Ceramic samples of composition Ba_(1-3)xNd_(2x)Ti_(1-y)ZryO_(3)(x=0.025;y=0.025 and 0.05)were synthesized by modified sol-gel *** confirmation,surface morphology and electrical properties of the samples were studied using XRD,FESEM,impedance spectroscopy and DC ***,AC and DC conductivities of the samples were recorded in the temperature range room temperature(RT)-500℃.From impedance data,various parameters like bulk resistance(R_(b)),bulk capacitance(C_(b)),grain resistance(R_(g)),grain boundary resistance(R_(gb)),grain capacitance(C_(g))and grain boundary capacitance(Cgb)T were *** parameters were found to be function of both temperature and *** and grain boundary relaxation times(τ_(g),τ_(gb))were also evaluated as a function of *** AC and DC conductivity plots activation energies for conduction were *** obtained lead to improved understanding of conductivity and charge transportation kinetics in the present system of samples.

关键词： Sol-gel method BaTiO_(3) impedance spectroscopy DC conductivity AC conductivity

Synthesis, XRD &SEM Studies of Zinc Substitution in Nickel Ferrites by Citrate Gel Technique

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World Journal of Condensed Matter Physics 2012年第3期2卷 153-159页

作者： K. Rama Krishna D. Ravinder K. Vijaya kumar ch. Abraham Lincon Department of chemistry P. G. College of Science Osmania University Hyderabad India Department of Physics Jawaharlal Nehru Technological University Hyderabad College of Engineering Nachupally (Kondagattu) India Department of Physics Malla Reddy College of Engineering & Technology Secunderabad India Department of Physics P. G. College of Science Osmania University Hyderabad India

Ni-Zn ferrite with a nominal composition of Ni1–XZnXFe2O4 (X = 0, 0.2, 0.6, 0.8, 0.9 & 1.0) ferrite powders have been successfully prepared at a very low temperature (180℃) by a novel auto combustion process using citric acid as a coordinating agent. Phase purity of the solid solutions has been confirmed by X-ray diffraction. Morphological, elemental composition characterizations of the prepared samples were performed by high resolution scanning electron microscopy and energy dispersive spectroscopy (EDS). Magnetic properties of all samples are obtained by using VSM (Vibrating Sample Magnetometer) in the range of 10 K oe. The saturation magnetization values of the samples are carried out from the B-H loop. The effect of composition on saturation magnetization and magnetic moment are studied in this paper. The results showed that Saturation magnetization and magnetic moment values increases gradually as Zn2+ composition increases, it reaches maximum value 70.28 emu/gm for (X = 0.6) and decreases further with increasing Zn2+ composition.

关键词： Ni-Zn Ferrite Citrate Precursor Auto Combustion Saturation Magnetization Magnetic Moment

Molecular dynamics study on growth of carbon dioxide and methane hydrate from a seed crystal

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chinese Journal of chemical Engineering 2019年第9期27卷 2074-2080页

作者： Prajakta Nakate Bappa Ghosh Subhadip Das Sudip Roy Rajnish kumar chemical Engineering and Process Development National Chemical LaboratoryPune 411008India Physical and Materials chemistry Division National Chemical LaboratoryPune 411008India Department of chemistry Chaudhary Ranbir Singh UniversityfindHaryana-126102 Department of chemical Engineering Indian Institute of TechnologyMadrasChennai 600036Tamil NaduIndia

In the current work,molecular dynamics simulation is employed to understand the intrinsic growth of carbon dioxide and methane hydrate starting from a seed crystal of methane and carbon dioxide *** comparison was carried out because it has relevance to the recovery of methane gas from natural gas hydrate reservoirs by simultaneously sequestering a greenhouse gas like *** seed crystal of carbon dioxide and methane hydrate was allowed to grow from a super-saturated mixture of carbon dioxide or methane molecules in water *** different concentrations(1:6 and 1:8.5)of CO2/ch4 molecules per water molecule were chosen based on gas–water composition in hydrate *** molecular level growth as a function of time was investigated by all atomistic molecular dynamics simulation under suitable temperature and pressure range which was well above the hydrate stability zone to ensure significantly faster growth *** concentration of CO2 molecules in water played a significant role in growth kinetics,and it was observed that maximizing the CO2 concentration in the aqueous phase may not result in faster growth of CO2 *** the contrary,methane hydrate growth was independent of methane molecule concentration in the aqueous *** have validated our results by performing experimental work on carbon dioxide hydrate where it was seen that under conditions appropriate for liquid CO2,the growth for carbon dioxide hydrate was very slow in the beginning.

关键词： ch4 recovery Natural gas hydrate CO2 sequestration Kinetics F4 order parameter Cage dynamics Thermodynamics

Isospin dependent properties of the isotopic chains of Scandium and Titanium nuclei within the relativistic mean-field formalism

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chinese Physics C 2022年第8期46卷 155-169页

作者： Praveen K.Yadav Raj kumar M.Bhuyan School of Physics and Materials Science Thapar Institute of Engineering and TechnologyPatiala-147004PunjabIndia Center for Theoretical and Computational Physics Department of PhysicsFaculty of ScienceUniversity of MalayaKuala Lumpur 50603Malaysia Institute of Research and Development Duy Tan UniversityDa Nang 550000Vietnam

Density-dependent nuclear symmetry energy is directly related to iso spin asymmetry for finite and infinite nuclear *** is critical to determine the coefficients of symmetry energy and their related observables because they hold great importance in different areas of nuclear physics,such as the analysis of the structure of ground state exotic nuclei and neutron star *** ground state bulk properties of Scandium(Z=21) and Titanium(Z=22) nuclei are calculated,such as their nuclear binding energy(B.E.),quadrupole deformation(β_2),two-neutron separation energy(S_(2 n)),differential variation in the two-neutron separation energy(dS_(2 n)),and root-mean-square charge radius(r_(ch)).The iso spin properties,namely the coefficient of nuclear symmetry energy and its components,such as the surface and volume symmetry energy of a finite isotopic chain,from the corresponding quantities of infinite nuclear matter,are also ***,we correlate the neutron-skin thickness with the coefficient of symmetry energy and the related observables corresponding to the isotopic chains of these *** coherent density fluctuation model(CDFM) is used to estimate the iso spin-dependent properties of finite nuclei,such as symmetry energy,surface symmetry energy,and volume symmetry energy,from their corresponding component in infinite nuclear *** relativistic mean-field(RMF) formalism with non-linear NL3 and relativistic-Hartree-Bogoliubov theory with density-dependent DD-ME2 interaction parameters are employed in the *** weight function |F(x)|^(2) is estimated using the total density of each nucleus,which in turn is used with the nuclear matter quantities to obtain the effective symmetry energy and its components in finite *** calculate the ground state bulk properties,such as nuclear binding energy,quadrupole deformation,two-neutron separation energy,differential variation in the two-neutron separation energy,and root-mean-square charge radius,fo

关键词： relativistic energy density functional symmetry energy weight function isospin asymmetry

Vibrational Spectroscopy of ch/CD Stretches in Propadiene： An Algebraic Approach

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chinese Physics Letters 2009年第2期26卷 36-38页

作者： Joydeep choudhury Nirmal kumar Sarkar Srinivasa Rao Karumuri Ramendu Bhattacharjee Department of Physics Assam University Silchar- 788011 India Department of Physics Karimganj College Karimganj-788710 India

Using Hamiltonian based on Lie algebraic method, the stretching vibrational modes of C3H4 and C3D4 molecules are calculated up to higher overtones. The model appears to describe C-H and C-D stretching modes with less number of parameters. The locality parameter ξ confirms the highly local behaviour of the stretching modes of these molecules.

关键词： VIBRATIONAL spectra SPECTRUM analysis ALLENE LIE algebras HAMILTONIAN systems MOLECULES

ALMA and GMRT Studies of Dust Continuum Emission and Spectral Lines Toward Oort Cloud Comet C/2022 E3(ZTF)

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Research in Astronomy and Astrophysics 2024年第12期24卷 81-92页

作者： Arijit Manna Sabyasachi Pal Sekhar Sinha Sushanta kumar Mondal Department of Physics and Astronomy Midnapore City College Department of Physics Sidho-Kanho-Birsha University

The atomic and molecular compounds of cometary ices serve as valuable knowledge into the chemical and physical properties of the outer solar nebula, where comets are formed. From the cometary atmospheres, the atoms and gas-phase molecules arise mainly in three ways:（i） the outgassing from the nucleus,（ii） the photochemical process, and（iii） the sublimation of icy grains from the nucleus. In this paper, we present the radio and millimeter wavelength observation results of Oort cloud non-periodic comet C/2022 E3（ZTF） using the Giant Metrewave Radio Telescope（GMRT） band L and the Atacama Large Millimeter/submillimeter Array（ALMA） band 6. We do not detect continuum emissions and an emission line of atomic hydrogen（H I） at rest frequency 1420 MHz from this comet using the GMRT. Based on ALMA observations, we detect the dust continuum emission and rotational emission lines of methanol（ch3OH） from comet C/2022 E3（ZTF）. From the dust continuum emission, the dust production（Afρ） activity of comet ZTF is 2280 ± 50 cm. Based on LTE spectral modeling, the column density and excitation temperature of ch3OH toward C/2022 E3（ZTF） are（4.50 ± 0.25） × 1014cm-2and 70 ± 3 K respectively. The integrated emission maps show that ch3OH was emitted from the coma region of the comet. The production rate of ch3OH toward C/2022 E3（ZTF） is（7.32 ± 0.64） × 1026molecules s-1. The fractional abundance of ch3OH with respect to H2O in the coma of the comet is 1.52%. We also compare our derived abundance of ch3OH with the existence modeled value, and we see the observed and modeled values are quite similar. We claim that ch3OH is formed via the subsequential hydrogenation of formaldehyde（H2CO） on the grain surface of comet C/2022 E3（ZTF）.

关键词： Astrochemistry Comets: general Planets and satellites: composition Radio continuum: planetary systems Submillimeter: planetary systems

characteristics of La-modified Ni-Al_2O_3 and Ni-SiO_2 catalysts for CO_x-free hydrogen production by catalytic decomposition of methane

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Journal of Energy chemistry 2013年第6期22卷 853-860页

作者： chatla Anjaneyulu Velisoju Vijay kumar Suresh K.Bhargava Akula Venugopal Inorganic & Physical chemistry Division CSIR-Indian Institute of Chemical Technology College of Science Engineering and Health Advanced Materials & Industrial Chemistry School of Applied Sciences RMIT University

Hydrotalcite precursors of La modified Ni-Al2O3 and Ni-SiO2 catalysts prepared by co-precipitation method and the catalytic activities were examined for the production of COx-free H2 by ch4 decomposition. Physico-chemical characteristics of fresh, reduced and used catalysts were evaluated by XRD, TPR and O2 pulse chemisorptions, TEM and BET-SA techniques. XRD studies showed phases due to hydrotalcite-like precursors in oven dried form produced dispersed NiO species upon calcination in static air above 450 C. Raman spectra of deactivated samples revealed the presence of both ordered and disordered forms of carbon. Ni-La-Al2O3catalyst with a mole ratio of Ni : La : Al = 2 : 0.1 : 0.9 exhibited tremendously high longevity with a hydrogen production rate of 1300 molH2 mol 1 Ni. A direct relationship between Ni metal surface area and hydrogen yields was established.

关键词： ch4 decomposition Ni-La-Al hydrotalcite Ni metal surface area COx-free H2