Extreme modes in the system of differential heat- and mass-transfer equations

With regard to the desiccation process and the experimental methods of determining the thermophysical characteristics of capillary-porous colloidal bodies, the system of differential heat- and mass-transfer equations is analyzed for extreme modes.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 24, No. 1, pp. 152–155, January, 1973.     

Reducing the equations of nonlinear non-steady-state high-intensity heat- and mass-transfer to equivalent linear equations. An analogy of the theory of high-intensity heat- and mass-transfer

We have derived the basic forms of the equivalent linear equations for nonlinear high-intensity non-steady-state heat- and mass-transfer. Methods are proposed for the modeling of these processes on the basis of various physical analogies.     

Effect of sound on heat- and mass-transfer processes in gaseous media

Expressions are derived for the dimensionless heat- and mass-transfer coefficients for bodies of simple shape and the calculated relations are compared with the existing experimental data. The limits of applicability of the results are considered.     

Forced oscillations in a heat- and mass-transfer system with a finite transfer rate

The solution of the general boundary-value problem for the one-dimensional inhomogeneous heat- and mass-transfer equation with a finite transfer rate is investigated. The forced oscillations are analyzed in several special cases.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 21, No. 1, pp. 165–167, July, 1971.     

General method for transformation of heat- and mass-transfer processes in a bed

A general method is worked out for transforming the output curve (of the temperature or concentration) for a bed of width h₁ into the output curves for beds of any other width h_m, where h_m ?5 h₁.     

Breakdown of stability of heat- and mass-transfer processes in certain gas-liquid systems

Using the critical equation for the limiting regimes of a gas-liquid system with independent flow rate of the gaseous phase, experimental results on the stability of a two-phase mixture are generalized to thermosiphons.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 34, No. 6, pp. 1001–1006, June, 1978.     

Problem of the nonstationary state of heat- and mass-transfer processes in binary gaseous mixtures

Nonstationary heat- and mass-transfer processes in gaseous mixtures are considered, and expressions are obtained for the heat-diffusion ratio and for the contribution of diffusion thermal conduction in conductive heat transfer.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 40, No. 4, pp. 726–731, April, 1981.     

Investigation of certain heat- and mass-transfer parameters in the ocean by an optical method

An optical method for studying fluctuations of the index of refraction of liquids and gases is described. The apparatus is described and experimental values of the coefficient of anisotropy and the magnitude of the temperature fluctuations for sea-water are presented.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 32, No. 4, pp. 602–606, April, 1977.     

Study of heat- and mass-transfer characteristics in the symmetry planes of bodies of different shapes

Results are presented from comparative studies of heat- and mass-transfer characteristics in flows about bodies of different shapes at angles of attack.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 50, No. 1, pp. 5–14, January, 1985.     

Dependence of the temperature coefficient of drying on the heat- and mass-transfer similarity criteria for various values of the heat-transfer Biot number

The influence of similarity criteria on the temperature coefficient of drying is analyzed for various values of the heat-transfer Biot number.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 33, No. 1, pp. 131–136, July, 1977.     

Methods of analyzing the thermal conditions of engineering systems and inverse heat- and mass-transfer problems

Problems of thermal investigation in the course of designing and analyzing thermoprotective systems are considered.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 56, No. 5, pp. 359–362, March, 1989.     

Boundary conditions for the heat- and mass-transfer equations of coarsely disperse aerosols in a turbulent flow

Boundary conditions taking account of particle interaction with the boundary surface are obtained on the basis of the Chapman-Enskog method of solving the kinetic equation.Translated from Inzhenerno-fizicheskii Zhurnal, Vol. 61, No. 4, pp. 546–553, October, 1991.     

Investigation of convective heat- and mass-transfer on sublimation of a rotating sphere in rarefied air

The process of heat and mass transfer for a substance on sublimation of a rotating sphere in rarefied air is examined experimentally in this paper. We have determined the average values for the coefficients of convective heat transfer at pressures of 105 N/m² for the medium at rotation velocities for the sphere up to 60 rad/sec.     

Mathematical simulation of heat- and mass-transfer processes in separated flows with a laminar mixing region at low reynolds numbers

The lower limit of applicability of the mathematical model of heat and mass transfer constructed by Batchelor and Lavrent'ev for separated flow past a bottom trench is extended.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 32, No. 5, pp. 847–855, May, 1977.     

A method for the solution of nonlinear heat- and mass-transfer equations on network and combined electrical models

A term containing the transfer coefficient that is a function of the potential is isolated in the transfer equations. In mathematical simulation on electrical network models this method makes it possible to reduce the number of nonlinear elements and significantly to simplify the method of solving the nonlinear transfer equations on combined electrical models.     

Ritz solutions for axisymmetric temperature and stress fields in finite elastic cylinders

Variational formulations are given for the stationary heat conduction and thermodelasticity problems of an orthotropic, non-homogeneous, finite length, cylinder. It is demonstrated that a single-element approach based upon Ritz approximations and the method of Lagrange multipliers offers and efficient means for computing the temperature and thermal stress distributions.     

Thermodynamic analysis of mass-transfer motive forces in the course of crystallization from solutions

On the basis of taking the volume, mass, momentum, and energy of the surface phase into account the structure of the motive forces of mass transfer to the phase interface (and from it into the carrier phase) in crystallization and solution is established. The correctness of the relations obtained is verified in two systems.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 42, No. 2, pp. 260–266, February, 1982.     

Recovery of alumina and alkali in Bayer red mud by the formation of andradite-grossular hydrogarnet in hydrothermal process

Bayer red mud (RM) is an alumina refinery waste product rich in aluminum oxides and alkalis which are present primarily in the form of sodium hydro-aluminosilicate desilication product (DSP). A hydrothermal process was employed to recover alumina and alkali from "Fe-rich" and "Fe-lean" RM, the two representative species of RM produced in China. The hydrothermal process objective phase is andradite-grossular hydrogarnet characterized by the isomorphic substitution of Al and Fe. Batch experiments were used to evaluate the main factors influencing the recovery process, namely reaction temperature, caustic ratio (molar ratio of Na(2)O to Al(2)O(3) in sodium solution), sodium concentration and residence time. The results revealed that the Na(2)O content of 0.5 wt% and A/S of 0.3 (mass ratio of Al(2)O(3) to SiO(2)) in leached residue could be achieved with Fe-rich RM under optimal conditions. However, the hydrothermal treatment of Fe-lean RM proved less successful unless the reaction system was enriched with iron. Subsequent experiments examined the effects of the ferric compound's content and type on the substitution ratio.     

浅谈烘干法水分测定仪的检定方法

该文着重介绍烘干法水分测定仪的检定方法。温度和质量是这类水分测定仪的两大关键计量指标,因此,将水分测定仪的检定分为衡量装置和烘干装置两大部分,其中衡量装置依据OIMLR76直接检定,而烘干装置则采用间接测量的方法。根据上述两部分的性能指标,参照OIMLR59综合评定水分测定仪的计量性能。     

Synthesis and formation mechanism of hematite hollow microspheres by a one-pot templateless surfactant-free hydrothermal process

Hollow microspheres of hematite (α-Fe₂O₃) were prepared by a simple hydrothermal treatment of ferrous ammonium sulphate hexahydrate ((NH₄)₂Fe(SO₄)₂·6H₂O) aqueous solution without any surfactants and additives at 180–200 °C. The products were characterized by XRD, FE-SEM and TEM. The results show that α-Fe₂O₃ hollow microspheres are about 1 μm in diameters and are composed of α-Fe₂O₃ nanoparticles with a diameter range from 50 nm to 150 nm. The effects of reaction parameters such as reaction time, temperature and [(NH₄)₂Fe(SO₄)₂·6H₂O] on the morphology of the final product were investigated. A potential formation mechanism of α-Fe₂O₃ hollow microspheres was also proposed, where the intermediate, urchin-like goethite, served as a sacrificial template for the formation of hollow structure. The reaction parameters-depended morphologies of the final products consisted well with the proposed formation mechanism.