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Том 477, № 2 (2017)
- Год: 2017
- Статей: 5
- URL: https://journals.rcsi.science/0012-5008/issue/view/9282
Chemistry
The effect of the type of conductivity on the initiation and formation of pores in silicon during electrochemical etching
Аннотация
The effect of the type of Si conductivity on the initiation and formation of pores in silicon samples during electrochemical etching was studied. The difference between the pore formation processes in n- and p-conducting silicon was attributed to the properties and the nature of layers formed in the initial period of etching on the Si surface. A possible composition of the layers formed on the Si surface was proposed considering the chemistry of Si interaction with the etching agent.
271-273
Carbonized fibers based on polyvinyl alcohol
Аннотация
On the basis on polyvinyl alcohol (PVA), carbonized fibers were produced in the form of a complex technical thread with tensile strength above 200 MPa and specific electrical conductivity of at least 0.5 S/cm. Using thermogravimetric and differential thermal analysis, Raman scattering, and wide-angle X-ray diffraction, structures of these fibers were characterized. The structural parameters of carbonized PVA fibers are close to the parameters of carbonized coal tar pitch obtained by heat treatment at 1000°C. The structure and properties of carbonized fibers modified with potassium bisulfate were also studied.
274-277
Synthesis of chlorin–phorbin dimer with carborane fragment
Аннотация
A chlorin–phorbin dimer with the carborane fragment attached to the dimer via amide bond has been synthesized. The obtained boronated dimer is of interest for a further study as a promising agent for combined application in boron neutron capture and photodynamic therapy of oncological diseases.
278-281
Chemical Technology
Computer modeling of the chemical-power engineering process of roasting of a moving multilayer mass of phosphorite pellets
Аннотация
A mathematical model and a computer model were developed for the multistage chemical and energy engineering process of roasting of phosphorite pellets, which includes the reactions of dissociation of carbonates and the processes of sintering in a moving dense multilayer mass of phosphorite pellets in a complex chemical and energy engineering system—travelling grate machine. The adequacy of the developed mathematical model was tested. Computational experiments were performed to determine the roasting process parameters at various physicochemical characteristics of the phosphate feedstock and the external heattransfer gas flow.
282-285
Optimizing the energy efficiency of the chemical and energy engineering process of drying of a moving dense multilayer mass of phosphorite pellets
Аннотация
Conceptual and mathematical formulations were developed for the problem of optimizing the chemical and energy engineering process (CEEP) of drying of a moving dense multilayer mass of phosphorite pellets in a complex chemical and energy engineering system (CEES)—travelling grate machine—as a discrete dynamic programming problem. A criterion of the efficiency of the drying CEEP was taken to be the minimum of the cost of the heat and power consumed in the drying CEEP. The obtained results of solving the optimization problem were applied to calculate the characteristics of the energy efficiency of the drying of pellets in the CEES. It was determined that, under the optimal conditions of the drying of the moving multilayer mass of pellets, there is no overmoistening zone, the heat- and moisture-transfer processes are intensified, the power consumption reduces, and the quality of the final product increases.
286-289