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Plasma science and Technology 2017年第9期19卷 35-40页

作者： g c DAs gyan Darshan Academy VIP RoadGuwahati-781022India

Based on quasipotential analysis, a plasma sheath is studied through the derivation of the sagdeev potential equation in dusty plasma coexisting with adiabatically heated electrons and ions. salient features as to the existence of sheaths are shown by solving the sagdeev potential equation through the Runge–Kutta method, with appropriate consideration of adiabatically heated electrons and ions in the dynamical system. It has been shown that adiabatic heating of plasma sets a limit to the critical dust speed depending on the densities and Mach number, and it is believed that its role is very important to the sheath. One present problem is the contraction of the sheath region whereby dust grains levitated into the sheath lead to a crystallization similar to the formation of nebulons and are compressed to a larger chunk of the dust cloud by shrinking of the sheath. Our overall observations advance knowledge of sheath formation and are expected to be of interest in astroplasmas.

关键词： sheath heated dynamical Kutta Runge derivation shrinking coexisting grains compressed

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移情心理学

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

作者： (瑞士)c.g. 荣格

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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(cates 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

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

Neutrino masses,cosmological inflation and dark matter in a variant U(1)B-L model with type II seesaw mechanism

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chinese Physics c 2021年第2期45卷 621-630页

作者： J.g.Rodrigues A.c.O.santos J.g.Ferreira Jr c.A.de s.Pires Departamento de Física Universidade Federal da ParaíbaCaixa Postal 500858051-970João PessoaPBBrasil Departamento de Física Universidade Federal do Rio Grande do Norte59078-970NatalRNBrasil

In this study,we implemented the type Ⅱ seesaw mechanism into the framework of the U(l)B-L gauge *** achieve this,we added a scalar triplet,A,to the canonical particle content of the U(l)B-Lgauge *** imposing that the U(l)B-L gauge symmetry be spontaneously broken at TeV scale,we show that the type Ⅱ seesaw mechanism is realized at an intermediate energy scale,more precisely,at approximately 109 *** prevent heavy right-handed neutrinos from disturbing the mechanism,we evoke a Z2 discrete ***,as a result,we have standard neutrinos with mass around eV scale and right-handed neutrinos with mass in TeV scale,with the lightest one fulfilling the condition of dark *** developed all of these in this *** addition,we show that the neutral component of Δ may perform unproblematic non-minimal inflation with loss of unitarity.

关键词： models beyond the standard model particle-theory and field-theory models of the early universe neutrino mass and mixing

Improved Osteointegration of Ti-6Al-4V-implants of Different surface Texture by the Use of Bone Morphogenetic Protein-3 (BMP-3)

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Journal of Wuhan University of Technology(Materials science) 2005年第B12期20卷 301-303页

作者： Esenwein s A Esenwein s Herr g Hauser J Muhr g Hartwig c-H Department of surgery BG Trauma Center Bergmannsheil University Hospital Buerkle-de-la-Camp-Platz 1 D-44789 Bochum Germany Dental Practice Am Obstmarkt 5 D-71522 Backnang Germany Advanced Tissue Regeneration gmbH Turmstr. 16 D-35578 Wetzlar Germany Department of Orthopaedics Michaelis-Hospital Eichenstrasse 34 D-20244 Hamburg Germany

Half of altogether 60 cylindrical implant devices made of titanium-aluminum-vanadium alloy （ Ti-6Al-4V） were plusna-sprayed with a hydroxyapatite-couting and the other half had a corundum blasted porous surface. 15 implants of each group of the titanium test buplants were coated with 230 μg porcine, high-purified BMP- 3-precipitute per implant. In each case a BMP- 3-couted and an uncoated control-device were implanted into the femoral part of the putellofemoral joint of the right and left leg of 30 adult giant rabbits. Histomorphological and histomorphometrical we found in both groups with BMP- 3-coated test devices an improved osteointegrution. stutistical evaluation using the t-test for matched samples showed 5 weeks after surgery a significant higher volume of tony formed bone of the BMP- 3-coated corundum- blasted or hydroxyapathe- coated Ti- 6Al- 4 V test devices compared to the non-couted controls of the same t）pe （p 〈 0.01, t-test for matched samples）. In both implant groups with BMP-couting a synergetic effect was verifiable although the bone ongrowth in the hydroxyaputite coated implants was more extensive than in the corundum blasted implants. Light microscopy demonstrated osteointegrution without connective tissue membrane around the surface of the implants. Our results indicate that composite metal implants,as used in endoprosthetics and implantology , are suitable carriers for BMP- 3 and im proved fixation of the implants can be achieved. The hydroxyapatite surface is superior to the corundum-blasted surface with regards to the observed parameters because of its pronounced bioactivity and its osteoconductive characteristics.

关键词： bone morphogenetic protein-3 BMP- 3 hydroxyapatite osteointegration surface coating bone ingrowth implantology

Biodegradation of crystal Violet by Agrobacterium radiobacter

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