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Chinese Physics b 2018年第10期27卷 231-239页

作者： J P Singh V T Pham T Hayat S Jafari F E Alsaadi b k roy Department of Electrical Engineering National Institute of Technology Silchar 788010 India School of Electronics and Telecommunications Hanoi University of Science and Technology 01 Dai Co Viet Hanoi Viet Nam Department of Mathematics Faculty of Science King Abdulaziz University Jeddah 21589 Saudi Arabia Department of Mathematics Quaid-I-Azam University Islamabad 44000 Pakistan Ambikar University of Technology Tehran 15875-4413Iran Department of Information Technology Faculty of Computing and IT King Abdulaziz University Jeddah Saudi Arabia

This paper reports a new simple four-dimensional（4 D） hyperjerk chaotic system. The proposed system has only one stable equilibrium point. Hence, its strange attractor belongs to the category of hidden attractors. The proposed system exhibits various dynamical behaviors including chaotic, periodic, stable nature, and coexistence of various attractors. Numerous theoretical and numerical methods are used for the analyses of this system. The chaotic behavior of the new system is validated using circuit implementation. Further, the synchronization of the proposed systems is shown by designing an adaptive integrator backstepping controller. Numerical simulation validates the synchronization strategy.

关键词： new hyperjerk chaotic system stable equilibrium hidden attractors adaptive backstepping control synchronization

Effect of promoters on dynamics of gas-solid fluidized bed——Statistical and ANN approaches

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China Particuology 2007年第6期5卷 401-407页

作者： Y.k. Mohanty k.C. biswal G.k. roy b.P. Mohanty Department of Chemical Engineering GIET Gunupur 765 022 Rayagada Orissa India Department of Chemical Engineering NIT Rourkela 769008 Orissa India

In this study, a bubbling fluidized bed column, 99 mm in inside diameter and 960 mm in height, was used to investigate the effect of rod and disc promoters on fluctuation and expansion ratios. Factorial design （statistical approach） and artificial neural network （ANN） models were developed to predict the fluctuation and expansion ratios in this gas-solid fluidized bed with varying gas flow rates, bed heights, particle sizes and densities. The fluctuation and expansion predicted using these statistical and ANN models, for beds with and without promoters, were found to agree well with corresponding experiments. The statistical model was found to be superior to the ANN model due to its ability to take into account both individual and interactive effects. The rod promoters were found to be more effective in reducing bed fluctuation, and in increasing bed expansion at high gas mass velocities.

关键词： Gas-solid fluidized bed Fluctuation ratio Expansion ratio Promoter Factorial design Artificial neural network

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

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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(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

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

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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

Drop formation at nozzles submerged in quiescent continuous phase： an experimental study with TbP-dodecane and nitric acid system

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Nuclear Science and Techniques 2018年第6期29卷 110-118页

作者： Amitava roy MayurDarekar k. k. Singh k. T. Shenoy R. b. Grover Homi bhabha National Institute Anushaktinagar Mumbai 400094 India Chemical Engineering Division Bhabha Atomic Research Centre Mumbai 400085 India

Solvent extraction is an important process in the nuclear fuel cycle. Tributyl phosphate(TbP) diluted with dodecane is commonly used as a solvent for extracting heavy metals from nitric acid medium. Studies on hydrodynamics of a single drop, which is the smallest mass transfer entity, are required for better understanding of the complex mass transfer and phase separation phenomena that occur in extraction equipment. In this study, drop formation at nozzles is studied using 30% TbP-dodecane as the dispersed phase and dilute nitric acid as the quiescent continuous phase. Experiments are carried out to determine the drop diameter, jetting velocity, drop detachment height and drop detachment time for various dispersed phase velocities, nozzle diameters(1.91, 3.04, and 4.88 mm), and nitric acid concentrations(0.01, 1, 3 N). Drop formation is captured using high-speed imaging, which enables quantification of drop size, onset of jetting, drop detachment height, and drop detachment time. Experimental data are used to propose correlations for predicting drop diameter and minimum jetting velocity. The correlations are found to be very accurate with average absolute relative errors being 5.23 and 2.97%, respectively.

关键词：试验性硝酸静止沉没系统高速度分离现象磷酸盐

Hydrodynamics of three-phase fluidization of homogeneous ternary mixture in a conical conduit-Experimental and statistical analysis

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Chinese Journal of Chemical Engineering 2016年第10期24卷 1335-1343页

作者： R.k.Padhi D.T.k.Dora Y.k.Mohanty G.k.roy b.Sarangi Department of Chemical Engineering GIETGunupur-765 022RayagadaOdishaIndia Department of metallurgical Engineering ICITSarangaDhenkanalOdishaIndia

Hydrodynamics of conical fluidized bed differ from that of columnar beds by the fact that a velocity gradient exists along the axial direction of the *** gas–liquid–solid fluidized bed has emerged in recent years as one of the most promising devices for three-phase *** a device is of considerable industrial importance as evident from its wide applications in chemical,refining,petrochemical,biochemical processing,pharmaceutical and food *** explore this,a series of experiments have been carried out for homogeneous well-mixed ternary mixtures of dolomite of varying compositions in a three-phase conical fluidized *** hydrodynamic characteristics determined included the bed pressure drop,bed fluctuation and bed expansion *** single and combined effects of operating parameters such as superficial gas velocity,superficial liquid velocity,initial static bed height,average particle size and cone angle on the responses have been analyzed using response surface methodology(RSM).A 25 full factorial central composite experimental design has been *** of variance(ANOVA) showed a high coefficient of determination value and satisfactory prediction second-order regression models have been *** values of bed pressure drop,bed fluctuation and bed expansion ratios have been found to agree well with the developed correlations.

关键词： Gas-liquid-solid fluidization Conical bed bed pressure drop bed fluctuation ratio and bed expansion ratio ANOVA

bed dynamics of gas-solid fluidized bed with rod promoter

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China Particuology 2007年第4期5卷 261-266页

作者： Awadhesh kumar Gopendra k.roy Department of Civil Engineering National Institute of TechnologyRourkela 769008OrissaIndia Department of Chemical Engineering National Institute of TechnologyRourkela 769008OrissaIndia

The dynamic characteristics of a gas-solid fluidized bed with different rod promoters have been investigated in terms of bed expansion and fluctuation, minimum fluidization velocity and distributor-to-bed pressure drop ratio at minimum fluidization velocity. Experimentation based on statistical design has been carried out and model equations using factorial design of experiments have been developed for the above mentioned quantities for a promoted gas-solid fluidized bed. The model equations have been tested with additional experimental data. The system variables include four types of rod promoters of varying blockage volume, bed particles of four sizes and four initial static bed heights. A comparison between the predicted values of the output variables using the proposed model equation with their corresponding experimental ones shows fairly good agreement.

关键词： Dynamic characteristics Statistical design Gas-solid fluidization Rod promoter

A STUDY ON THE ESTIMATION OF TEMPERATURE STRUCTURE PARAMETER IN AbL WITH ELEVATED INVERSION

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Acta meteorologica Sinica 1995年第3期9卷 349-359页

作者： b.roy U.k.De b.Pal Physics Department Jadavpur University.Calcutta 700 032.India Department of Physics and Meteorology Indian Institute of TechnologyKharagpur 721 302India

Temperature structure parameter in the vertical is estimated once by using the turbulence outer scale approximation and another by using the Obukhov similarity relationship during the formation of an elevated inversion.A comparison of the profiles drawn using both the methods is done for the pur- pose of assessing the accuracy of the similarity method when applied to levels above the surface-based *** profiles obtained by both the methods are also compared with a similar profile obtained af- ter considering a bulk shear between the ground and top of the elevated layer.

关键词： kytoon Doppler sodar temperature structure parameter Obukhov similarity method elevated inversion

Recent Progress and Approaches on Carbon-Free Energy from Water Splitting

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Nano-Micro Letters 2019年第4期11卷 791-816页

作者： Aslam Hossain k.Sakthipandi A.k.M.Atique Ullah Sanjay roy Department of Physical and Inorganic Chemistry Institute of Natural Science and MathematicsUral Federal UniversityYekaterinburgRussia Department of Physics Sethu Institute of TechnologyKariapattiTamil Nadu 626115India Nanoscience and Technology Research Laboratory Atomic Energy CentreBangladesh Atomic Energy CommissionDhaka 1000Bangladesh Department of Chemistry Shibpur Dinobundhoo Institution(College)HowrahWest Bengal 711102India

Sunlight is the most abundant renewable energy resource,providing the earth with enough power that is capable of taking care of all of humanity’s desires-a hundred times ***,as it is at times diffuse and intermittent,it raises issues concerning how best to reap this energy and store it for times when the Sun is not *** increasing population in the world and modern economic development,there will be an additional increase in energy *** that use daylight to separate water into individual chemical elements may well be the answer to this issue,as water splitting produces an ideal *** such devices that generate fuel were to become widely adopted,they must be low in cost,both for supplying and ***,it is essential to research for cheap technologies for water *** review summarizes the progress made toward such development,the open challenges existing,and the approaches undertaken to generate carbon-free energy through water splitting.

关键词： Water splitting Renewable energy sources Hydrogen generation Photocatalysis Nanostructure

In silico designing of power conversion efficient organic lead dyes for solar cells using todays innovative approaches to assure renewable energy for future

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npj Computational Materials 2017年第1期3卷 263-274页

作者： Supratik kar Juganta k.roy Jerzy Leszczynski Interdisciplinary Center for Nanotoxicity Department of Chemistry and BiochemistryJackson State UniversityJacksonMS 39217USA

Advances in solar cell technology require designing of new organic dye sensitizers for dye-sensitized solar cells with high power conversion efficiency to circumvent the disadvantages of silicon-based solar *** silico studies including quantitative structureproperty relationship analysis combined with quantum chemical analysis were employed to understand the primary electron transfer mechanism and photo-physical properties of 273 arylamine organic dyes from 11 diverse chemical families explicit to iodine *** direct quantitative structure-property relationship models enable identification of the essential electronic and structural attributes necessary for quantifying the molecular prerequisites of 11 classes of arylamine organic dyes,responsible for high power conversion efficiency of dye-sensitized solar ***,N,N′-dialkylaniline and indoline have been least explored classes under arylamine organic dyes for dye-sensitized solar ***,the identified properties from the corresponding quantitative structure-property relationship models of the mentioned classes were employed in designing of“lead dyes”.Followed by,a series of electrochemical and photo-physical parameters were computed for designed dyes to check the required variables for electron flow of dye-sensitized solar *** combined computational techniques yielded seven promising lead dyes each for all three chemical classes ***(130,183,and 46%)increment in predicted %power conversion efficiency was observed comparing with the existing dye with highest experimental %power conversion efficiency value for tetrahydroquinoline,N,N′-dialkylaniline and indoline,respectively maintaining required electrochemical parameters.

关键词： designing dye aniline