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Oxidation behavior of Fev_(2)O_(4)and FeCr_(2)O_(4)particles in the air:Nonisothermal kinetic and reaction mechanism

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1839-1848页

作者： Junyi Xiang Xi lu luwei Bai Hongru rao Sheng liu Qingyun Huang Shengqin Zhang Guishang Pei Xuewei lü School of Metallurgy and Materials Engineering Chongqing University of Science and TechnologyChongqing 401331China Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Rep.of Korea College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

High-temperature oxidation behavior of ferrovanadium(Fev_(2)O_(4))and ferrochrome(FeCr_(2)O_(4))spinels is crucial for the application of spinel as an energy material,as well as for the clean usage of high-chromium vanadium ***,the nonisothermal oxidation behavior of Fev_(2)O_(4)and FeCr_(2)O_(4)prepared by high-temperature solid-state reaction was examined by thermogravimetry and X-ray diffraction(XRD)at heating rates of 5,10,and 15 K/*** apparent activation energy was determined by the Kissinger-Akahira-Sunose(KAS)method,whereas the mechanism function was elucidated by the Malek ***,in-situ XRD was conducted to deduce the phase transformation of the oxidation mechanism for Fev_(2)O_(4)and FeCr_(2)O_(4).The results reveal a gradual increase in the overall apparent activation energies for Fev_(2)O_(4)and FeCr_(2)O_(4)during *** stages of the oxidation process are observed based on the oxidation conversion rate of each *** oxidation mechanisms of Fev_(2)O_(4)and FeCr_(2)O_(4)are complex and have distinct *** particular,the chemical reaction controls the entire oxidation process for Fev_(2)O_(4),whereas that for FeCr_(2)O_(4)transitions from a three-dimensional diffusion model to a chemical reaction *** to the in-situ XRD results,numerous intermediate products are observed during the oxidation process of both compounds,eventually resulting in the final products FevO_(4)and v2O_(5)for Fev_(2)O_(4)and Fe_(2)O_(3)and Cr_(2)O_(3)for FeCr_(2)O_(4),respectively.

关键词： Fev_(2)O_(4) FeCr_(2)O_(4) oxidation nonisothermal kinetics mechanism

A novel approach for speaker diarization system using TMFCC parameterization and lion optimization

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Journal of Central South University 2017年第11期24卷 2649-2663页

作者： v.subba Ramaiah R.Rajeswara rao Mahatma Gandhi Institute of Technology KokapetHyderabadTelangana 500075India Jawaharlal Nehru Technological University Kakinada KakinadaAndhra Pradesh 535002India

In audio stream containing multiple speakers, speaker diarization aids in ascertaining "who speak when". This is an unsupervised task as there is no prior information about the speakers. It labels the speech signal conforming to the identity of the speaker, namely, input audio stream is partitioned into homogeneous segments. In this work, we present a novel speaker diarization system using the Tangent weighted Mel frequency cepstral coefficient(TMFCC) as the feature parameter and lion algorithm for the clustering of the voice activity detected audio streams into particular speaker groups. Thus the two main tasks of the speaker indexing, i.e., speaker segmentation and speaker clustering, are improved. The TMFCC makes use of the low energy frame as well as the high energy frame with more effect, improving the performance of the proposed system. The experiments using the audio signal from the ElSDSR corpus datasets having three speakers, four speakers and five speakers are analyzed for the proposed system. The evaluation of the proposed speaker diarization system based on the tracking distance, tracking time as the evaluation metrics is done and the experimental results show that the speaker diarization system with the TMFCC parameterization and lion based clustering is found to be superior over existing diarization systems with 95% tracking accuracy.

关键词： speaker diarization Mel frequency cepstral coefficient i-vector extraction lion algorithm

Phase transition of multi-component(TiZrvNb)C ceramics—Part I:Phase decomposition induced by carbon content

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Journal of Advanced Ceramics 2024年第5期13卷 679-688页

作者： Qingyi Kong rao Zhang lei Chen Sijia Huo Wenyu lu Yujin Wang Boxin Wei Yu Zhou Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150080China Key laboratory of Advanced Structure‒Function Integrated Materials and Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China School of Materials Science and Chemical Engineering Harbin University of Science and TechnologyHarbin 150001China National Key laboratory of Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China

Phase decomposition can effectively enhance the mechanical properties of carbide ceramics and can overcome the difficulty of enhancing the mechanical properties of single-phase multicomponent carbide *** this work,a series of nonstoichiometric(TiZrvNb)Cx ceramics were prepared by spark plasma sintering(SPS)at different *** effects of the carbon content on the phase composition,microstructure evolution,and mechanical properties were investigated in *** decomposition occurred with decreasing carbon *** different solid solutions of(Ti,v)-rich and Zr-rich phases formed from the decomposition of equimolar single-phase solid solutions,namely,the Zr-poor phase and Zr-rich phase,*** distribution of Nb element is relatively *** semicoherent interfaces between the Zr-poor phase and the Zr-rich phase can harden and strengthen effectively under the synergistic effect of grain *** with phase decomposition structures have apparent advantages compared to single-phase high-entropy *** work provides an important train of thought for the microstructure tailoring and properties optimization of multi-component carbide ceramics.

关键词： multicomponent ceramics nontoichiometry microstructure evolution phase decomposition mechanical properties

PGE and isotopic characteristics of Shergol and Suru valley Ophiolites,Western ladakh:Implications for supra-subduction tectonics along Indus Suture Zone

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Geoscience Frontiers 2021年第3期12卷 473-488页

作者： Irfan Maqbool Bhat Talat Ahmad D.v.subba rao Srinivasan Balakrishnan N.v.Chalapathi rao Department of Earth Sciences University of KashmirSrinagar 190006India vice Chancellors Office University of KashmirSrinagar 190006India Geochemistry Division CSIR-National Geophysical Research Institute(NGRI)Hyderabad 500007India Department of Earth Sciences Pondicherry UniversityPuducherry 605014India Centre of Advanced Study in Geology Institute of ScienceBanaras Hindu UniversityVaranasi 221005India

Present study reports the PGE-geochemistry of mantle peridotites and Nd-isotope geochemistry of arc related mafic rocks from the Indus Suture Zone(ISZ),western *** total PGE concentration of the Shergol and Suru valley peridotites(∑PGE=96-180 ppb)is much higher than that of the primitive mantle and global ophiolitic mantle *** studied peridotites show concave upward PGE-distribution patterns with higher palladium-group PGE/Iridium-group PGE ratios(i.e.,0.8-2.9)suggesting that the partial melting is not the sole factor responsible for the evolution of these *** observed PGE-distribution patterns are distinct from residual/refractory mantle peridotites,which have concave downward or flat PGE-distribution *** enrichment of palladium-group PGE as well as other whole-rock incompatible elements(e.g.,lIlE and lREE)and higher Pd/Ir ratio(1.1-5.9)reflects that these peridotites have experienced fluid/melt interaction in a supra-subduction zone(SSZ)tectonic ***,the Shergol mafic intrusives and Dras mafic volcanics,associated with the studied peridotites,have high^(143)Nd/^(144)Nd ratios(i.e.,0.512908-0.513078 and 0.512901-0.512977,respectively)and positiveε_(Nd)(t)(calculated for t=140 Ma)values(i.e.,+5.3 to+8.6 and+5.1 to+6.6,respectively),indicating derivation from depleted mantle sources within an intra-oceanic arc setting,similar to Spongtang and Nidar ophiolites from other parts of ladakh *** transition from SSZ-type Shergol and Suru valley peridotites to Early Cretaceous tholeiitic Shergol mafic intrusives followed by tholeiitic to calc-alkaline Dras mafic volcanics within the Neo-Tethys Ocean exhibit characteristics of subduction initiation mechanism analogous to the Izu-Bonin-Mariana arc system within western Pacific.

关键词： PGE Nd-isotope Mantle peridotites Ophiolites ladakh Neo-Tethys Ocean

Implications for the lithospheric structure of Cambay rift zone,western India:Inferences from a magnetotelluric study

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Geoscience Frontiers 2020年第5期11卷 1743-1754页

作者： Nagarjuna Danda C.K.rao Amit Kumar P.Rama rao P.B.v.subba rao Dr.K.S.Krishnan Geomagnetic Research laboratory IIGAllahabad221505India Indian Institute of Geomagnetism New PanvelNavi Mumbai410218India Department of Geophysics Andhra UniversityVisakhapatnam530003India

Broad-band and long-period magnetotelluric(MT)data were acquired along an east-west trending traverse of nearly 200 km across the Kachchh,Cambay rift basins,and Aravalli-Delhi fold belt(ADFB),western *** regional strike analysis of MT data indicated an approximate N59°E geoelectric strike direction under the traverse and it is in fair agreement with the predominant geological strike in the study *** decomposed transverse electric(TE)-and transverse magnetic(TM)-data modes were inverted using a nonlinear conjugate gradient algorithm to image the electrical lithospheric structure across the Cambay rift basin and its surrounding *** studies show a thick(~1-5 km)layer of conductive Tertiary-Mesozoic sediments beneath the Kachchh and Cambay rift *** resistive blocks indicate presence of basic/ultrabasic volcanic intrusives,depleted mantle lithosphere,and different Precambrian structural *** crustal conductor delineated within the ADFB indicates the presence of fluids within the fault zones,sulfide mineralization within polyphase metamorphic rocks,and/or Aravalli-Delhi sediments/*** observed conductive anomalies beneath the Cambay rift basin indicate the presence of basaltic underplating,volatile(CO2,H2 O)enriched melts and channelization of melt fractions/fluids into crustal depths that occurred due to plume-lithosphere *** variations in electrical resistivity observed across the profile indicate that the impact of Reunion plume on lithospheric structures of the Cambay rift basin is more dominant at western continental margin of India(WCMI)and thus support the hypothesis proposed by Campbell&Griffiths about the plume-lithosphere interactions.

关键词： Cambay rift Deccan basalts Magnetotellurics Partial melt Reunion plume

Enhanced Energy Efficient with a Trust Aware in MANET for Real-Time Applications

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Computers, Materials & Continua 2023年第4期75卷 587-607页

作者： M.v.Narayana vadla Pradeep Kumar Ashok Kumar Nanda Hanumantha rao Jalla subba Reddy Chavva Department of CSE Guru Nanak Institutions Technical CampusHyderabadRanga Reddy DistrictTelangana501506India Department of CSE B V Raju Institute of TechnologyNarsapurMedakTelangana502313India Department of CSE T.R.R.Government Degree College KandukurKandukurA.P.523105India Department of IT VFST&Research(Deemed to be University)VadlamudiA.P.522213India

Mobile ad hoc networks (MANETs) are subjected to attack detectionfor transmitting and creating new messages or existing message *** attacker on another node evaluates the forging activity in themessage directly or indirectly. Every node sends short packets in a MANETenvironment with its identifier, location on the map, and time through *** attackers on the network broadcast the warning message usingfaked coordinates, providing the appearance of a network collision. Similarly,MANET degrades the channel utilization performance. Performancehighly affects network performance through security algorithms. This paperdeveloped a trust management technique called Enhanced Beacon TrustManagement with Hybrid Optimization (EBTM-Hyopt) for efficient clusterhead selection and malicious node detection. It tries to build trust amongconnected nodes and may improve security by requiring every participatingnode to develop and distribute genuine, accurate, and trustworthy materialacross the network. Specifically, optimized cluster head election is done periodicallyto reduce and balance the energy consumption to improve the lifetimenetwork. The cluster head election optimization is based on hybridizingParticle Swarm Optimization (PSO) and Gravitational Search OptimizationAlgorithm (GSOA) concepts to enable and ensure reliable routing. Simulationresults show that the proposed EBTM-HYOPT outperforms the state-of-thearttrust model in terms of 297.99 kbps of throughput, 46.34% of PDR, 13%of energy consumption, 165.6 kbps of packet loss, 67.49% of end-to-end delay,and 16.34% of packet length.

关键词： MANET malicious nodes clustering trust management beacon message

Genotype×year interaction of pod and seed mass and stability of Pongamia pinnata families in a semi-arid region

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Journal of Forestry Research 2020年第4期31卷 1333-1346页

作者： G.R.rao B.Sarkar B.M.K.Raju P.Sathi Reddy A.v.M.subba rao Jessie Rebecca ICAR-Central Research Institute for Dryland Agriculture SantoshnagarHyderabadTelangana State 500059India Tropical Forest Research Institute(TFRI) Indian Council of Forestry Research&EducationMinistry of EnvironmentForest&Climate ChangeGovt.of IndiaJabalpur 482021India

Sixteen pongamia families were evaluated in a field experiment for eight consecutive years in dryland conditions to identify stable,high-yielding *** trial was conducted in a randomized complete block design with three *** family,consisting of nine trees per replication,was planted at a spacing of3 m x 3 *** stability was analyzed using(1)Eberhart and Russel’s regression coefficient(β_i)and deviation from regression(S_d^2),(2)Wrike’s ecovalence(W_i);(3)Shukla stability variance(σ_i^2);and(4)Piepho and lotito’s stability index(l_i).Families were also analyzed for adaptability and stability using AMMI and GGE biplots graphical *** study revealed significant variances due to family and family x year interaction for pod and seed *** performed differently and ranked differently across *** performance of families was influenced by both genetic factor and environmental conditions in different *** families tested,TNMP20,Acc14,TNMP14 and Acc30 were high yielders for pods,and Acc14,Acc30,TNMP6,RAK19 and TNMP14 were high for seed *** to the Eberhart and Russell model,Acc30,TNMP14 and TNMP3 were stable across *** the graphical view of family x year interaction based on AMMI methods,TNMP3,TNMP4 and TNMP14 had greater stability with moderate seed yield,and Acc14 and Acc30 had moderate stability with high seed *** the other hand,GGE biplots revealed Acc14,Acc30 and TNMP14 as high yielders with moderate *** and GGE biplots were able to capture nonlinear parts of the family x year interaction that were not be captured by the Eberhart and Russel model while also identifying stable *** on different methodologies,Acc14,Acc30 and TNMP14 were identified as high yielding and stable families for promoting pongamia cultivation as a biofuel crop for semi-arid regions.

关键词： Biofuel Pongamia Genetic diversity Stability AMMI (additive main effects multiplicative interaction) GGE biplots Multi-year trial SvD(singular value decomposition)

Petrogenesis of carbonatitic lamproitic dykes from Sidhi gneissic complex,Central India

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Geoscience Frontiers 2018年第2期9卷 531-547页

作者： M.Satyanarayanan D.v.subba rao M.l.Renjith S.P.Singh E.v.S.S.K.Babu M.M.Korakoppa CSIR-National Geophysical Research Institute Hyderabad 500007India Geological Survey of India Hyderabad 500068India Department of Geology Bundelkhand UniversityJhansi 284128India NCEGR Geological Survey of IndiaBengaluru 560070India

Petrographic, mineral chemical and whole-rock geochemical characteristics of two newly discovered lamproitic dykes(Dyke 1 and Dyke 2) from the Sidhi Gneissic Complex(SGC), Central India are presented here. Both these dykes have almost similar sequence of mineral-textural patterns indicative of:(1) an early cumulate forming event in a deeper magma chamber where megacrystic/large size phenocrysts of phlogopites have crystallized along with subordinate amount of olivine and clinopyroxene;(2) crystallization at shallow crustal levels promoted fine-grained phlogopite, K-feldspar, calcite and Fe-Ti oxides in the groundmass;(3) dyke emplacement related quench texture(plumose K-feldspar, acicular phlogopites) and finally(4) post emplacement autometasomatism by hydrothermal fluids which percolated as micro-veins and altered the mafic phases. Phlogopite phenocrysts often display resorption textures together with growth zoning indicating that during their crystallization equilibrium at the crystal-melt interface fluctuated multiple times probably due to incremental addition or chaotic dynamic self mixing of the lamproitic magma. Carbonate aggregates as late stage melt segregation are common in both these dykes, however their micro-xenolithic forms suggest that assimilation with a plutonic carbonatite body also played a key role in enhancing the carbonatitic nature of these dykes. Geochemically both dykes are ultrapotassic(K_2 O/Na_2 O: 3.0-9.4) with low CaO, Al_2 O_3 and Na_2 O content and high SiO_2(53.3-55.6 wt.%)and K_2 O/Al_2 O_3 ratio(0.51-0.89) characterizing them as high-silica lamproites. Inspite of these similarities, many other features indicate that both these dykes have evolved independently from two distinct magmas. In dyke 1, phlogopite composition has evolved towards the minette trend(Al-enrichment) from a differentiated parental magma having low MgO, Ni and Cr content; whereas in dyke 2, phlogopite composition shows an evolutionary affinity towards the lamproit

关键词： lamproite Phlogopite Carbonate aggregates Metasomatized mantle Sidhi Gneissic Complex Central India

Flotation studies on low grade graphite ore from eastern India

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International Journal of Mining Science and Technology 2015年第3期25卷 415-420页

作者： vasumathi N. vijaya Kumar T.v. Ratchambigai S. subba rao S. Bhaskar Raju G. CSIR-National Metallurgical laboratory Madras Centre CSIR Madras Complex

A low grade graphite ore from eastern India was beneficiated by flotation to improve its quality. The ore was composed of 87.80%ash and 8.59%fixed carbon. Primary coarse wet grinding （d80：186 μm） followed by rougher flotation in Denver flotation cell using diesel as collector and pine oil as frother yielded a rougher concentrate. Regrinding （d80：144 μm） of this rougher concentrate was opted for further libera-tion of graphite. It was followed by cleaning in laboratory flotation column. This combined process of relatively coarse primary grinding followed by regrinding and cleaning in flotation column resulted in final concentrate of 7.44% yield with 89.65% fixed carbon and 6.00% ash. This approach of two-stage grinding to recover the flake graphite at the coarsest possible grind can help to minimize grinding energy costs. A conceptual flow sheet which is cost effective was developed based on this methodology.

关键词： Graphite liberation Froth flotation Column flotation Flow-sheet development