检索结果-南通市图书馆

study on kinetics of thermal decomposition of low LOI goethetic hematite iron ore

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining science and Technology 2017年第6期27卷 1031-1036页

作者： Beuria P.C. biswal s.k. Mishra B.k. Roy G.G. Mineral Processing Department CSIR–Institute of Minerals and Materials TechnologyBhubaneswar 751013India Indian Institute of Technology Kharagpur 721302India

In the present study, the kinetics of thermal decomposition of hydrated minerals associated in natural hematite iron ores has been investigated in a fixed bed system using isothermal methods of kinetic analysis. Hydrated minerals in these hematite iron ores are kaolinite, gibbsite and goethite, which contribute to the loss on ignition(LOI) during thermal decomposition. Experiments in fixed bed have been carried out at variable bed depth(16, 32, 48 and 64 mm),temperature(400-1200 ℃) and residence time(30,45, 60 and 75 min) for iron ore samples. It is observed that beyond a certain critical bed depth(16 mm), 100% removal of LOI is not found possible even at higher temperature and higher residence time. Most of the solid-state reactions of isothermal kinetic analysis have been used to analyze the reaction mechanism. The raw data are modified to yield fraction reacted "α" versus time and used for developing various forms of "α" functions.f(α) is the inverse of first derivative of g(α) with respect to α. The study demonstrates that decomposition of hydrated mineral in hematite follows the chemical *** estimated activation energy values in all the experimental situations are found to high, of the order of 60 kJ/mol, reinstating that the reactions are indeed controlled by moving phase boundary and random nucleation.

关键词： Loss on ignition Goethite kaolinite Gibbsite Roasting Pellet feed kinetic analysis

Management of ruptured renal angiomyolipoma with bilateral staghorn calculi

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Urology 2024年第3期11卷 509-510页

作者： Amit sharma Deepak biswal kishor Roy R.T.Raghavendra Department of Urology AIIMSRaipurCGIndia

Dear Editor,We present a case of ruptured renal angiomyolipoma(AML)and bilateral renal staghorn *** discuss about the management of this patient by angioembolization,partial nephrectomy,and pyelolithotomy,followed by contralateral interval percutaneous nephrolithotomy(PCNL).Our case is a 40-year-old male who presented with history of dull aching and dragging sensation in bilateral flanks of 6-month *** was admitted and evaluated at other hospital for dizziness,sweating,and loss of *** was found to have bilateral staghorn calculi and left AML and was referred to our institute for further management after initial *** proper written and informed consent was taken from the patient for management as well as publication of the report and images,maintaining the patient’s anonymity.

关键词： admitted sensation renal

Transcriptomic and Macroscopic Architectures of Multimodal Covariance Network Reveal Molecular–structural–Functional Co-alterations

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2024年第1期2023卷 471-487页

作者： Lin Jiang Yueheng Peng Runyang He Qingqing Yang Chanlin Yi Yuqin Li Bin Zhu Yajing si Tao Zhang Bharat B.biswal Dezhong Yao Lan Xiong Fali Li Peng Xu The Clinical Hospital of Chengdu Brain science Institute MOE Key Lab for NeuroinformationUniversity of Electronic Science and Technology of ChinaChengdu 611731China school of Life science and Technology Center for Information in BioMedicineUniversity of Electronic Science and Technology of ChinaChengdu 611731China school of Psychology Xinxiang Medical UniversityXinxiang 453003China school of science Xihua UniversityChengdu 610039China Department of Biomedical Engineering New Jersey Institute of TechnologyNewarkNJUSA school of Electrical Engineering Zhengzhou UniversityZhengzhou 450001China Research Unit of NeuroInformation Chinese Academy of Medical Sciences2019RU035ChengduChina Montreal Neurological Institute and Hospital McGill UniversityMontrealQCCanada Department of Electrical and Computer Engineering Faculty of Science and TechnologyUniversity of MacaoMacaoChina Radiation Oncology key Laboratory of sichuan Province 610041 ChengduChina Rehabilitation Center Qilu Hospital of Shandong UniversityJinan 250012China

Human cognition is usually underpinned by intrinsic structure and functional neural co-activation in spatially distributed brain *** to lacking an effective approach to quantifying the covarying of structure and functional responses,how the structural–functional circuits interact and how genes encode the relationships,to deepen our knowledge of human cognition and disease,are still ***,we propose a multimodal covariance network(MCN)construction approach to capture interregional covarying of the structural skeleton and transient functional activities for a single *** further explored the potential association between brain-wide gene expression patterns and structural–functional covarying in individuals involved in a gambling task and individuals with major depression disorder(MDD),adopting multimodal data from a publicly available human brain transcriptomic atlas and 2 independent *** analysis showed a replicable cortical structural–functional fine map in healthy individuals,and the expression of cognition-and disease phenotype-related genes was found to be spatially correlated with the corresponding MCN *** analysis of cell type-specific signature genes suggests that the excitatory and inhibitory neuron transcriptomic changes could account for most of the observed correlation with task-evoked MCN differences.

关键词： alterations evoked spatially

kinetics of thermal decomposition of hydrated minerals associated with hematite ore in a fluidized bed reactor

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2017年第3期24卷 229-239页

作者： P.C. Beuria s.k. biswal B.k. Mishra G.G. Roy Institute of Minerals and Materials Technology Council of Scientific & Industrial Research Bhubaneswar-751013 India Indian Institute of Technology Kharagpur-721302 India

The kinetics of removal of loss on ignition(LOI) by thermal decomposition of hydrated minerals present in natural iron ores(i.e.,kaolinite,gibbsite,and goethite) was investigated in a laboratory-scale vertical fluidized bed reactor(FBR) using isothermal methods of kinetic *** in the FBR in batch processes were carried out at different temperatures(300 to 1200°C) and residence time(1 to 30 min) for four different iron ore samples with various LOIs(2.34wt% to 9.83wt%).The operating velocity was maintained in the range from 1.2 to 1.4 times the minimum fluidization velocity(Umf).We observed that,below a certain critical temperature,the FBR did not effectively reduce the LOI to a desired level even with increased residence *** results of this study indicate that the LOI level could be reduced by 90% within 1 min of residence time at 1100°*** kinetics for low-LOI samples(s two different reaction mechanisms in two temperature *** lower temperatures(300 to 700°C),the kinetics is characterized by a lower activation energy(diffusion-controlled physical moisture removal),followed by a higher activation energy(chemically controlled removal of LOI).In the case of high-LOI samples,three different kinetics mechanisms prevail at different temperature *** temperature up to 450°C,diffusion kinetics prevails(removal of physical moisture);at temperature from 450 to 650°C,chemical kinetics dominates during removal of matrix *** temperatures greater than 650°C,nucleation and growth begins to influence the rate of removal of LOI.

关键词： thermal decomposition fluidized beds kinetic analysis hydrated iron ore activation energy

A model for expansion ratio in liquid-solid fluidized beds

在线全文

学校读者我要写书评

暂无评论

Particuology 2013年第6期11卷 789-792页

作者： Alok Tripathy A.k.sahu s.k.biswal B.k.Mishra Council of scientific and Industrial Research Institute of Minerals and Materials Technology

Liquid-solid fluidized beds are used in mineral processing industries to separate particles based on parti- cle size, density, and shape. Understanding the expanded fluidized bed is vital for accurately assessing its performance. Expansion characteristics of the fluidized bed were studied by performing several experi- ments with iron ore, chromite, quartz, and coal samples. Using water as liquid medium, experiments were conducted to study the effects of particle size, particle density, and superficial velocity on fluidized bed expansion. The experimental data were utilized to develop an empirical mathematical model based on dimensional analysis to estimate the expansion ratio of the fluidized bed in terms of particle character- istics, operating and design parameters. The predicted expansion ratio obtained from the mathematical model is in good agreement with the experimental data.

关键词： Fluidization Bed expansion Mathematical modelling Dimensional analysis Particle processing Void fraction

A numerical study of violent sloshing problems with modified MPs method

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2017年第4期29卷 659-667页

作者： Debadatta Jena kishore Chandra biswal Department of Civil Engineering National Institute of Technology

A numerical study on violent liquid sloshing phenomenon in a partially filled rectangular container is carried out by using moving particle semi-implicit（MPs） method. The present study deals with the implementation of five modifications all together over the original MPs method. The modifications include improved source terms for pressure Poisson equation, special approximation technique for the representation of gradient differential operator, collective action of mixed free surface particle identification boundary conditions, effecting Neumann boundary condition on solving the PPE and fixing judiciously the parting distance among particles to prevent collision. The suitability of the kernel function used in the original MPs method along with these five modifications is investigated for violent sloshing problems. The present model ensures a good agreement between numerical results with the existing experimental observations. The model is successfully applied to a partially filled tank undergoing horizontal sinusoidal excitation to compute the sloshing wave amplitudes and pressure on tank walls. The assessment of dynamic behaviour manifested in terms of base shear, overturning moment and impact pressure load exerted on tank ceiling induced by violent sloshing motion using MPs method is not reported in the open literature and has been efficiently carried out in the present study.

关键词： sloshing particle method impact pressure base shear overturning moment

Reduction behaviour of Odisha sands Complex,India ilmenite-coke composite pellets

在线全文

学校读者我要写书评

暂无评论

Journal of Central south University 2020年第6期27卷 1678-1690页

作者： D NAYAk N RAY N DAsH s s RATH s.k.biswal CsIR-Institute of Minerals&Materials Technology Bhubaneswar-751013OdishaIndia

Presently,ilmenite concentrates from Odisha sands Complex at Chhatrapur,India are utilized to produce TiO2 slag by direct smelting in an electric arc ***,the process involves the consumption of excess electrical energy and difficulty in handling the arc furnace due to frothing effects.A more efficient process of pre-reducing the ilmenite before smelting has been proposed in the present *** particular,studies have been undertaken on the reduction process of ilmenite-coke composite *** difference in the reduction behaviour of raw ilmenite and ilmenite-coke composite pellets has been established and compared with that of the pre-oxidized raw *** effects of various processing parameters like temperature,residence time,and reductant percentage on the metallization of composite pellets in a static bed have been *** of about 90%has been achieved at 1250°C for a reduction period of 360 min with a 4%coke ***,the reduced pellets have been characterized through chemical analysis,optical microscopy,field emission scanning electron microscopy and X-ray diffraction *** reduction behaviour of composite pellets has also been found better than that of pre-oxidized pellets indicating the former to be more efficient.

关键词： ilmenite composite pellet pre-oxidation reduction metallization

Frequency dependent electrical properties of Na_(2)Pb_(2)R_(2)W_(2)Ti_(4)Nb_(4)O_(30)(R=Nd,sm)ceramics

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2014年第3期3卷 215-223页

作者： Lalatendu biswal Piyush RDAs Banarji BEHERA Department of Physics SOTKIIT UniversityBhubaneswar-751024OdishaIndia Department of Physics Veer Surendra Sai University of TechnologyBurla-768018SambalpurIndia school of Physics Sambalpur UniversityJyoti ViharBurla-768019OdishaIndia

In the present research work,frequency dependent electrical properties of tungsten bronze structured compounds Na2Pb2R2W2Ti4Nb4O30(R=Nd,sm)are reported.X-ray diffraction(XRD)study of polycrystalline ceramic samples confirms the formation of compounds with orthorhombic *** of frequency dependent electrical data in the framework of modulus and conductivity formalism suggests the presence of thermally activated relaxation process in the compounds,which show Arrhenius *** magnitudes of activation energies give the nature of the relaxing *** real and imaginary parts of complex modulus trace the depressed semicircle in complex plane,suggesting non-Debye type relaxation process in the *** power law behavior of admittance data is successfully modeled by introducing constant phase element(CPE)to the equivalent circuit.A large value of power law parameter(n)of CPE below ferroelectric transition temperature(Tc)is attributed to the cooperative response of the dipoles which is reduced above *** behavior is correlated with the frequency dependence of CPE,suggesting a physical meaning to *** frequency dependent AC conductivity at different temperatures follows Jonscher’s universal power *** and West formalism is used to estimate the hopping rate,activation enthalpy and charge carrier concentration in the materials.

关键词： ceramics electrical properties microstructure electrical conductivity

Nrf2 is required for normal postnatal bone acquisition in mice

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bone Research 2014年第4期2卷 231-240页

作者： Jung-Hyun kim Vandana singhal shyam biswal Rajesh k Thimmulappa Douglas J Di Girolamo Department of Environmental Health sciences Johns Hopkins Bloomberg School of Public HealthBaltimoreMDUSA Department of Orthopaedic surgery Johns Hopkins University School of MedicineBaltimoreMDUSA

A large body of literature suggests that bone metabolism is susceptible to the ill effects of reactive species that accumulate in the body and cause cellular dysfunction. One of the body＇s front lines in defense against such damage is the transcription factor, Nrf2. This transcription factor regulates a plethora of antioxidant and cellular defense pathways to protect cells from such damage. Despite the breadth of knowledge of both the function of Nrf2 and the effects of reactive species in bone metabolism, the direct role of Nrf2 in skeletal biology has yet to be thoroughly examined. Thus, in the current study, we have examined the role of Nrf2 in postnatal bone metabolism in mice. Mice lacking Nrf2 （Nrf2-/-） exhibited a marked deficit in postnatal bone acquisition, which was most severe at 3 weeks of age when osteoblast numbers were 12-fold less than observed in control animals. While primary osteoblasts from Nrf2-/- mice functioned normally in vitro, the colony forming capacity of bone marrow stromal cells （BMsCs） from these mice was significantly reduced compared to controls. This defect could be rescued through treatment with the radical scavenger N-acetyl cysteine （NAC）, suggesting that increased reactive species stress might impair early osteoblastogenesis in BMsCs and lead to the failure of bone acquisition observed in Nrf2-/- animals. Taken together, these studies suggest Nrf2 represents a key pathway in regulating bone metabolism, which may provide future therapeutic targets to treat osteoporosis.

关键词： bone Nrf2 is required for normal postnatal bone acquisition in mice