Showing papers in "Advances in Chemical Engineering in 1966"
TL;DR: The chapter provides a summary of attempts of applying engineering analysis for elucidating growth and replication phenomena in very simple systems: cultures of unicellular organisms reproducing by binary fission.
Abstract: Publisher Summary This chapter focuses on the unstructured models of microbial cell population, distributed structured models, segregated structured models, and growth of single microbial cells. It offers quantitative analyses of some simpler biological phenomena and suggests experimental work that may profitably be carried out. The chapter provides a summary of attempts of applying engineering analysis for elucidating growth and replication phenomena in very simple systems: cultures of unicellular organisms reproducing by binary fission. The study of biological systems so as to apply the knowledge gained to nonbiological systems is familiar to electrical engineers. State in an unstructured model can only refer to population density or to concentration of protoplasm, because, by definition, a model is unstructured if only one state variable appears. The basic supposition in distributed models is that protoplasm is composed of two structural components, whose interaction with each other and with the surrounding medium produces growth. The gross metabolic rates of the culture represent averages over the distribution of cell structures. One of the principal problems is then to establish the factors, which determine the distribution.
185 citations
TL;DR: This chapter focuses on the field of low Reynolds number flows, with particular regard to the hydrodynamic resistance of particles in this regime using symbolic “drag coefficients” and symbolic heat- and mass-transfer “coefficients” for describing the intrinsic, interphase transport properties of particles for a wide variety of boundary conditions.
Abstract: Publisher Summary This chapter focuses on the field of low Reynolds number flows, with particular regard to the hydrodynamic resistance of particles in this regime. Use of symbolic “drag coefficients” and symbolic heat- and mass-transfer “coefficients” furnishes a unique method for describing the intrinsic, interphase transport properties of particles for a wide variety of boundary conditions. The particle resistance is characterized by a partial differential operator that represents its intrinsic resistance to vector or scalar transfer, independently of the physical properties of the fluid, the state of motion of the particle, or of the unperturbed velocity or temperature fields at infinity. The chapter discusses different particles in its context. One of these particles is helicoidally isotropic particles that furnish the simplest examples of bodies manifesting screw-like behavior. These particles are isotropic, in that their properties are the same in all directions. Yet they possess a sense and spin as they settle in a fluid.
151 citations
TL;DR: In this paper, heat transfer to drops moving in a constant-temperature field and continuously varying temperature field is discussed, and three models are taken into account: rigid drop, completely mixed drop, and drop with internal circulation.
Abstract: Publisher Summary The basic characteristics of heat transfer between dispersed and continuous media are of both scientific and practical interest. The advantages of direct-contact heat transfer over the conventional processes using metallic transfer surfaces have lately stimulated research on its utilization for water desalination projects. Despite intensive efforts toward better understanding of transfer phenomena between drops and continuous media, accurate prediction of the transfer coefficients for a given system can as yet only be hoped for. Nevertheless, accumulated experience may provide an indication of the transfer mechanism to be encountered and the relevant coefficients may be estimated accordingly. This chapter discusses heat transfer to drops moving in a constant-temperature field and continuously varying temperature field. Heat is transferred to drops and bubbles with simultaneous phase change. While discussing about constant-temperature field, three models are taken into account: rigid drop, completely mixed drop, and drop with internal circulation. Work on direct-contact heat exchangers was stimulated earlier by the quest for economic water-desalination units. Multiphase exchange, where latent heat is transferred among the immiscible fluids, has been effectively used in direct-contact freezing units in which a dispersed volatile fluid evaporates in the saline water with simultaneous freezing of part of the water.
47 citations
TL;DR: In this paper, a general two-component bubble growth solution for arbitrary initial temperature and concentration was proposed, where the initial temperature is a function of the radial distance between the boundary layer and bubble volume.
Abstract: Publisher Summary The study of diffusive bubble growth processes adds an extra dimension of complexity over certain probable situations. It is not only necessary to consider the convective motion, resulting from the large change in density upon vaporization, in the diffusion equation, but also separately to consider the equation of motion, because inertial, surface tension, and viscous effects may be appreciable. A more general two-component bubble growth solution permits both the initial temperature and concentration to be the arbitrary functions of the radial distance. The same procedures used to solve the single-component problem are employed. A general solution is obtained and various limiting cases are examined. The theory of isolated bubble growth in a liquid of arbitrary initial temperature and/or concentration distribution is well established, providing that the boundary layer volume is smaller than the bubble volume.
26 citations