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Early Phases of Star Formation: Testing chemical Tools

Research in Astronomy and Astrophysics 2024年第1期24卷 96-118页

作者： n.c.Martinez S.Paron cOnIcET-Universidad de Buenos Aires.Instituto de Astronomía y Física del Espacio Ciudad Universitaria(C1428EGA)Ciudad Autónoma de Buenos AiresArgentina

Star-forming processes strongly influence the ISM ***,many high-quality databases are available at millimeter *** them,it is possible to carry out studies that review and deepen previous *** these studies involve large samples of sources,it is preferred to use direct tools to study the molecular *** the aim of testing these tools such as the use of the Hcn/Hnc ratio as a thermometer,and the use of H^(13)cO^(+),Hc_(3)n,n_(2)H^(+) and c_(2)H as "chemical clocks," we present a molecular line study toward 55 sources representing massive young stellar objects at different evolutionary stages:infrared dark clouds(IRDcs),highmass protostellar objects(HMPOs),hot molecular cores(HMcs) and ultracompact H II *** found that the use of the Hcn/Hnc ratio as a universal thermometer in the ISM should be taken with care because the Hcn optical depth is a big issue that can affect the ***,this tool should be utilized only after a careful analysis of the Hcn spectrum,checking that no line,neither the main nor the hyperfine ones,presents absorption *** point out that the analysis of the emission of H^(13)cO^(+),Hc_(3)n,n_(2)H^(+) and c_(2)H could be useful to trace and distinguish regions among IRDcs,HMPOs and *** molecular line widths of these four species increase from the IRDc to the HMc stage,which can be a consequence of the gas dynamics related to the starforming processes taking place in the molecular *** results not only contribute with more statistics,acting as a probe of such chemical tools,useful to obtain information in large samples of sources,but also complement previous works through the analysis of other types of sources.

关键词： stars:formation ISM:molecules ISM:clouds

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Imprints of a gravitational wave through the weak field deflection of photons

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chinese Physics c 2024年第8期48卷 240-245页

作者： Reggie c.Pantig Ali Övgün Physics Department Mapúa University658 Muralla St.IntramurosManila 1002Philippines Physics Department Eastern Mediterranean UniversityFamagusta99628 North Cyprusvia Mersin 10Turkiye

In this study,we investigate the novel phenomenon of gravitational lensing experienced by gravitational waves traveling past a Schwarzschild black hole perturbed by a specific,first-order,polar gravitational *** apply the gauss-Bonnet theorem,finding a topological contribution to the deflection of light rays passing near the black *** demonstrate that the deflection angle can be determined by analyzing a region entirely outside the path of the light ray,leading to a calculation based solely on the parameters of the perturbing wave(Legendre polynomial order,l;frequency,σ).This approach offers a unique perspective on gravitational lensing and expands our understanding of black hole interactions with gravitational waves.

关键词： supermassive black holes gravitational waves chaos weak deflection angle gauss-Bonnet theorem

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Effect of Al_(2)O_(3)on the Mechanical Properties of(B_(4)c+Al_(2)O_(3))/Al neutron Absorbing Materials

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1411-1420页

作者： J.X.cai B.M.Shi n.Li Y.Liu Z.g.Zhang Y.n.Zan Q.Z.Wang B.L.Xiao Z.Y.Ma Shi‑changxu Innovation center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Laboratory of nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China nuclear Equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.Ltd.Beijing 100840China Department of Materials Science School of Mechanical EngineeringShenyang UniversityShenyang 110044China

B_(4)c/Al composites are widely utilized as neutron absorbing materials for the storage and transportation of spent nuclear *** order to improve the high-temperature mechanical properties of B_(4)c/Al composites,in-situ nano-Al_(2)O_(3)was introduced utilizing oxide on Al powder *** this study,the Al_(2)O_(3)content was adjusted by utilizing spheroid Al powder with varying diameters,thereby investigating the impact of Al_(2)O_(3)content on the tensile properties of(B_(4)c+Al_(2)O_(3))/Al *** was found that the pinning effect of Al_(2)O_(3)on the grain boundaries could hinder the recovery of dislocations and lead to dislocation accumulation at high *** the result,with the increase in Al_(2)O_(3)content and the decrease in grain size,the high-temperature strength of the composites increased *** finest Al powder used in this investigation had a diameter of 1.4μm,whereas the resultant composite exhibited a maximum strength of 251 MPa at room temperature and 133 MPa at 350℃,surpassing that of traditional B_(4)c/Al composites.

关键词： Al matrix composites neutron absorbing materials (B_(4)c+Al_(2)O_(3))/Al composites High-temperature strength

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Measurement of yields and angular distributions ofγ-quanta from the interaction of 14.1 MeV neutrons with oxygen,phosphorus,and sulfur

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chinese Physics c 2024年第3期48卷 79-92页

作者： D.n.grozdanov n.A.Fedorov S.B.Dabylova Yu.n.Kopatch I.n.Ruskov V.R.Skoy T.Yu.Tretyakova c.Hramco P.I.Kharlamov g.V.Pampushik P.g.Filonchik A.V.Andreev Joint Institute for nuclear Research(JInR) DubnaRussia Institute for nuclear Research and nuclear Energy Bulgarian Academy of SciencesSofiaBulgaria Faculty of Physics Lomonosov Moscow State UniversityMoscowRussia L.n.gumilyov Eurasian national University AstanaKazakhstan Skobeltsyn Institute of nuclear Physics Moscow State UniversityMoscowRussia Institute of chemistry of Moldova ChisinauRepublic of Moldova Moscow Institute of Physics and Technology MoscowRussia

A study of the inelastic scattering of neutrons with an energy of 14.1 MeV on the nuclei of oxygen,phosphorus,and sulfur was performed at the TAngRA facility at JInR(Dubna).The experiment aimed to refine existing data and obtain new data on the yields and angular distributions ofγ-quanta emitted by the studied nuclei due to neutron-induced nuclear reactions using the tagged neutron *** types of detector systems were used to registerγ-***γ-ray yields were measured using a high-purity germanium(HPge)*** angular distributions ofγ-rays were obtained using a system of 18 scintillation detectors based on bismuth germanite Bi_(4)ge_(3)O_(12)(BgO)located around the *** performed experiments measured the yields of two transitions for the reaction of tagged neutrons with 16O,nine transitions for the reaction with ^(31)P,and nine transitions for the reaction with ^(32)S for the first *** angular anisotropy of theγ-radiation accompanying the inelastic scattering of neutrons with an energy of 14.1 MeV on ^(31)P nuclei was also measured for the first time.

关键词： tagged neutron method yields of gamma-quanta high-resolution gamma-spectrometry neutron-nuclear reactions neutron scattering

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Fault Location Method for Overhead Feeders with Distributed generation Units Based on Direct Load Flow Approach

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Journal of Modern Power Systems and clean Energy 2024年第4期12卷 1135-1146页

作者： charalampos g.Arsoniadis Vassilis c.nikolaidis Department of Electrical and computer Engineering Democritus University of ThraceXanthi 67100Greece

This paper proposes a novel fault location method for overhead feeders,which is based on the direct load flow *** method is developed in the phase domain to effec-tively deal with unbalanced network conditions,while it can al-so handle any type of distributed generation(Dg)units without requiring equivalent *** utilizing the line series parame-ters and synchronized or unsynchronized voltage and current phasor measurements taken from the sources,the method reli-ably identifies the most probable faulty *** the aid of an index,the exact faulty section among the multiple candi-dates is *** simulation studies for the IEEE 123-bus test feeder demonstrate that the proposed method accu-rately estimates the fault position under numerous short-circuit conditions with varying pre-fault system loading conditions,fault resistances,and measurement *** proposed meth-od is promising for practical applications due to the limited number of required measurement devices as well as the short computation time.

关键词： Fault location distribution system direct load flow distributed generation

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Assessment of cO_(2)storage prospect based on physical properties of Rio Bonito Formation rock units

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Energy geoscience 2024年第1期5卷 321-330页

作者： Richardson M.Abraham-A Stephanie San Martín cañas Isabella F.S.Miranda colombo c.g.Tassinari Institute of Energy and Environment(IEE) University of São Paulo(USP)Brazil Research centre for greenhouse gas Innovation(RcgI) University of Sãao Paulo(USP)Brazil

The physical properties of the rock units associated with the Rio Bonito Formation are presented in this study with the focus on modelling reservoir quality based on petrophysics-derived parameters to evaluate cO_(2)storage *** involves the modelling of the reservoir depths,thicknesses,flow zone indicators(FZI),and effective permeability(Keff)and presenting the cO_(2)storage efficiency factors peculiar to the rock units of the study *** results presented by this study for the stated objectives are not quite common in the *** values range from 200 mD to higher than 2000 mD,and FZI values are generally above 1.0 mm and up to 13.0 mm within the portions covered by the drilled *** sandstone units recorded are up to 20 m thick in some *** Keff and FZI models indicate the sandstone reservoirs as permeable units to support the injection and circulation of cO_(2)within the potential reservoir units of the Rio Bonio Formation across São Paulo *** from some points in the southeastern part of the study location,where the Rio Bonito are delineated at depths less than 800 m(minimum cO_(2)storage depth based on best practices),other portions are deeper,ranging from 950 m to 3500 ***-bedded layers will affect the integrity of the rocks as cO_(2)storage tanks or reservoir seals/traps/overburden within the *** bed thicknesses are up to 20 m in some ***,hybrid cO_(2)reservoir units are feasible,especially in portions where thin siltstone layers are sandwiched between sandstone units to provide considerable thicknesses based on cO_(2)storage *** current study shows that useable areas considering reservoir thickness,depth,and other physical qualities will significantly control the cO_(2)storage efficiency of the study *** studies featuring a detailed geophysical exploration of the site to confirm the availability and saturations of preexisting fluid(hydrocarbon and water)are encouraged

关键词： Rio Bonito Effective permeability Fluid transmissibility cO_(2)storage prospect Reservoir quality Overburden integrity Flow zones

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Semi-analytical investigation of heat transfer in a porous convective radiative moving longitudinal fin exposed to magnetic field in the presence of a shape-dependent trihybrid nanofluid

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 197-216页

作者： c.g.PAVITHRA B.J.gIREESHA M.L.KEERTHI Department of Pg Studies and Research in Mathematics Kuvempu UniversityShankaraghatta 577451India Department of Mathematics and Statistics M.S.Ramaiah University of Applied SciencesBengaluru 560058India

The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, are considered. These shapes include spherical(Fe_3O_4), cylindrical(Au), and platelet(Zn) configurations. The combination approach is utilized to evaluate the physical and thermal characteristics of the trihybrid and hybrid nanofluids, excluding the thermal conductivity and dynamic viscosity. These two properties are inferred by means of the interpolation method based on the volume fraction of nanoparticles. The governing equation is transformed into a dimensionless form, and the Adomian decomposition Sumudu transform method(ADSTM) is adopted to solve the conundrum of a moving fin immersed in a trihybrid nanofluid. The obtained results agree well with those numerical simulation results, indicating that this research is reliable. The influence of diverse factors on the thermal overview for varying noninteger values of γ is analyzed and presented in graphical representations. Furthermore, the fluctuations in the heat transfer concerning the pertinent parameters are studied. The results show that the heat flux in the presence of the combination of spherical, cylindrical, and platelet nanoparticles is higher than that in the presence of the combination of only spherical and cylindrical nanoparticles. The temperature at the fin tip increases by 0.705 759% when the value of the Peclet number increases by 400%, while decreases by 11.825 13% when the value of the Hartman number increases by 400%.

关键词： convection radiation moving longitudinal fin Adomian decomposition Sumudu transform method(ADSTM) trihybrid nanofluid magnetic field

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geochemistry and depositional environment of fuchsite quartzites from Sargur group,western Dharwar craton,India

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Acta geochimica 2024年第3期43卷 555-570页

作者： c.S.Sindhuja g.Harshitha c.Manikyamba K.S.V.Subramanyam cSIR(council of Scientific and Industrial Research)-national geophysical Research Institute(ngRI) Uppal RoadHyderabad 500007India

Meso-neoarchean fuchsite quartzites are present in different stratigraphic positions of Dharwar craton including the oldest(~3.3 ga)Sargur group of western Dharwar *** present study deals with the petro-graphic and geochemical characteristics of the fuchsite quartzites from the ghattihosahalli belt to evaluate their genesis,depositional setting and the enigma involved in the ancient sedimentation *** major mineral assemblages include quartz,fuchsite,and feldspars along with accessory kyanite and *** geochemical com-positions are characterized by high SiO_(2),Al_(2)O_(3),low MgO,caO,strongly enriched cr(1326–6899 ppm),Ba(1165–3653 ppm),Sr(46–210 ppm),V(107–868 ppm)and Zn(11–158 ppm)contents compared to the upper continental crust(Ucc).The Ucc normalized rare earth element(REE)patterns are characterized by depleted light REE[(La/Sm)Ucc=0.33–0.95]compared to heavy REE[(gd/Yb)_(Ucc)=0.42–1.65]with conspicuous positive Eu-anomalies(Eu/Eu^(*)=1.35–18.27)characteristic of hydrothermal solutions evidenced through the interlayered *** overall major and trace element systematics reflect a combined mafic-felsic provenance and suggest their deposition at a passive continental margin *** comprehensivefield,petrographic,and geo-chemical studies indicate that these quartzites are infiltrated by cr-richfluids released during high-grade metamorphism of associated ultramafic *** Sargur and the subse-quent Dharwar orogeny amalgamated diverse lithounits from different tectonic settings,possibly leading to the release of cr-richfluids and the formation of fuchsite quartzite during or after the *** sug-gest a pre-existing stable crust prior to the Sargur group and the link between orogenic events and various mineral deposits in the Dharwar craton.

关键词： Dharwar craton ghattihosahalli Fuchsite quartzite Provenance Depositional setting

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Magnesium oxide(MgO)nanoadsorbents in wastewater treatment:A comprehensive review

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Journal of Magnesium and Alloys 2024年第5期12卷 1709-1773页

作者： H.c.S.Perera V.gurunanthanan Anoop Singh M.M.M.g.P.g.Mantilaka g.Das Sandeep Arya Department of Physics Khalifa UniversityAbu Dhabi12788United Arab Emirates Postgraduate Institute of Science University of PeradeniyaPeradeniyaSri Lanka Department of Humanities and Sciences Guru Nanak Institutions Technical CampusIbrahimpatnamHyderabad501506India centre for global Health Research Saveetha Medical College and HospitalsSaveetha Institute of Medical and Technical SciencesChennai602105Tamil NaduIndia Department of Physics University of JammuJammu and Kashmir180006India

Wastewater contamination by heavy metals and synthetic dyes presents a significant environmental challenge,necessitating effective and sustainable separation *** review article provides a detailed examination of magnesium oxide(MgO)nanoparticles as an innovative nanoadsorbent for wastewater treatment,with a specific focus on heavy metal and dye *** review comprehensively explores various aspects of MgO nanoparticles,including their structural characteristics and synthesis *** article delves into the morphology and crystallographic arrangement of MgO nanoparticles,offering insights into their structural *** the complexity of adsorption processes,the review identifies and analyzes parameters influencing the adsorption efficiency of MgO nanoparticles,such as temperature,pH,contact time,initial concentration,and co-existing *** interplay between these parameters and the adsorption capability of MgO nanoparticles emphasizes the importance of optimizing operational ***,the review assesses various synthesis methods for MgO nanoparticles,including sol-gel,hydrothermal,precipitation,green synthesis,solvothermal,and template-assisted *** discusses the advantages,limitations,and resulting nanoparticle characteristics of each method,enabling readers to grasp the implications of synthesis processes on adsorption *** comprehensive review consolidates current insights into the effectiveness of MgO nanoparticles as a potent nanoadsorbent for removing heavy metals and dyes from wastewater covering a wide spectrum of aspects related to MgO ***,there is a need to investigate the use of MgO in the treatment of actual wastewater or river water,in order to leverage its cost-effectiveness and high efficiency for practical water treatment applications in real-time.

关键词： MgO nanoparticles nanoadsorbent Wastewater treatment Heavy metals Dye separation Adsorption Synthesis methods

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Approach for c_(1)to c_(2)products commencing from carbon dioxide:A brief review

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Petroleum 2024年第3期10卷 373-398页

作者： g.R.Dey Radiation and Photochemistry Division Bhabha Atomic Research CentreTrombayMumbai 400085India Homi Bhabha national Institute AnushaktinagarMumbai 400094India

The carbon dioxide(cO_(2))conversion to useable compounds remains a great contest to scientists,engineers,and environmentalists with regard to the reverse of the oxidative degradation of *** conversion is essential for the development of complementary fuels and raw materials for various industries,which in turn will help in avoiding the drastic increase in tropospheric temperature due to greenhouse effect leading to global *** solar energy is the earth's essential power source along with the other various forms of energy for example fossil fuels,hydropower,wind,and biomaterials,*** final goal is to establish the artificial photosynthesis,which can be replicated thru various chemical reduction techniques of cO_(2)by employing appropriate photo-,thermal-and electro-catalysts in order to produce different one carbon atom(c_(1))and higher carbon atoms containing ***,the utilization of clean and sustainable cO_(2)towards high-value products is of great interest today due to the recognized environmental worries and subsequent lessening of the fossil fuels utilization load to meet the energy demand of *** way,solar energy can directly and/or indirectly be altered and stored in chemical energy form for industrial as well as societal *** this article our endeavor is to summarize the advances in cO_(2)chemical reduction research area till date especially in free radical-based methods such as electrochemical,photochemical and plasma chemical for the development of carbon species up to two carbon(c_(2))atoms containing products perceived in the chemical reduction of cO_(2).The author hopes that this piece of work will be helpful to researchers and readers who are focused on the field of cO_(2).

关键词： Photocatalysis Electrocatalysis Plasmolysis Thermolysis carbon dioxide chemical reduction

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