Authors:María José Nieves-Remacha and Klavs F. Jensen
Ozonolysis of alkenes in liquid phase is conducted from micro scales to milli scales using a multichannel microreactor, a Corning low-flow reactor (LFR), and a Corning advanced-flow reactor (AFR). For the mass transfer limited test case of ozonolysis of 1-decene, maximum conversions that depend on the ozone availability in the gas phase are achieved regardless of the operating conditions, proving an excellent mass transfer in all three reactors. Ozonolysis of Sudan Red 7B dye provides visualization of the completion of the reaction in the glass-made AFR and LFR. Overall mass transfer coefficients are estimated to be on the order of 1/s in both the LFR and AFR, increasing with both liquid and gas flow rates. These values are within the same range observed in microchannels and one order of magnitude larger than in other conventional contactors.
thermal decomposition, and volatile matter has not been released. Heat and masstransfer in this stage could be expressed as follows: biomass continues to heat up at the constant heating rate and the moisture diffuse rapidly toward the surface to satisfy
A scientometric method is developed for studying the intersectional communications at scientific conferences. As an example, a series of multisectional Heat and Mass Transfer Conferences held in Minsk, USSR, during the years 1961–1980 are considered. The clusters of the interplay between the sections are constructed on the basis of the data from the registration cards of the Conference participants. Teh matrix of the topical interrelation of sections enables one to calculate the coefficient of the information impact of a section. A comparison of this coefficient with the resource indicators of sections makes it possible to grade the scientific justification of planning a series of multisectional scientific conferences.
(OAc–) proceeding in shell-core inorganic ion exchanger Ti (HPO4)2·1/2H2O has been studied and the diffusion equation whose boundary conditions are satisfied by a shell-core model was solved. Based on the equation solved and experimental data, the diffusion coefficients corresponding to the exchange process
(OAc–) and Li+–H+ (OAc–) at 17°C are found to be 7.7×10–9 and 6.2×10–8 cm2 s–1 and the activation energies 3.4×104 and 5.0×103 J mol–1, respectively. Compared to the gel type of styrene-divinylbenzene strong acid exchanger with 20% cross linking, it can be concluded that the rate of
This article is a review about the ways in which solidification and the melting may occur within emulsions submitted to steady
cooling and heating performed in a differential scanning calorimeter. Simple, multiple and mixed emulsions are considered.
Due to nucleation phenomena creating supercooled and supersaturated liquids, the DSC curves obtained during cooling and heating
are quite different. The influence of a solute in the disperse phase is described in detail. Some implications about the instabilities
of emulsions due to mass transfer phenomena are described.
Authors:M. Mikheeva, A. Novikov, B. Myasoedov, and S. Tikhomirov
The main regularities of membrane extraction of americium under conditions of different redox potentials in aqueous phases have been studied. The physico-chemical model of the process including steps of americium oxidation in feed solution, extraction by membrane, partial reduction on membrane surface, trans-membrane diffusion and reextraction to strip solution has been developed. The calculation of reduction rate constant on membrane surface has been carried out.
The removal of Na+ by a composite hydrated antimony pentoxide-sulfonated phenol-formaldehyde ion exchanger (C-HAP) from 4M HCl was studied using the breakthrough technique. The dynamic removal capacity for Na+ from 4M HCl is 12.3 mg Na+/g and 9.87 mg Na+/g at 0.2 ml/min and 0.8 ml/min, respectively. Height equivalent to a theoretical plate varies almost linearly with flow rate indicating particle diffusion control.