39 research outputs found
The kinetic parameters of peat conversion an oxidizing and inert media
В статье приведены экспериментально полученные данные технического анализа воздушно-сухого торфа, описаны особенности его применения в качестве энергетического топлива. Получены данные по скорости конверсии в инертной и окислительной среде при неизотермическом нагреве, проанализированы стадии разложения торфа в зависимости от степени конверсии образца. На основе проведенных исследований рассчитаны кинетические параметры конверсии для стадий выхода летучих и выгорания коксового остатка.The article presents the experimental data of the technical analysis of air-dry peat, the features of its use as an energy fuel are describes. The data on conversion rate in inert and oxidizing environment under non-isothermal heating, the decomposition stage of peat analyzed in the depending on the sample conversion degree. Based on these studies the kinetic conversion parameters for the yield of volatile and burning coke stages are calculated.Исследование выполнено в Уральском федеральном университете за счет гранта Российского научного фонда (проект №14-19-00524)
Immobilization of organic reagents on optically transparent mesoporous polymers and its analytical use
© 2015 Pleiades Publishing, Ltd. Sorption of organic reagents Arsenazo III and 1-(2-pyridylazo)-2-naphthol onto optically transparent mesoporous polymers prepared from macroinitiators and toluene 2,4-diisocyanate was studied. The possibility of preconcentration of organic reagents and their complexation with Cu(II) and Ca(II) ions in the polymer pore voids was demonstrated. Experiments on spectrophotometric analysis using the polymeric support showed that the lower limit of determination was 20 μg mL-1 for Ca(II) and 2 μg mL-1 for Cu(II)
Framed aromatic polyurethanes based on an anionic macroinitiator, 4,4'-diphenylmethane diisocyanate, and 4,4'-dihydroxy-2,2-diphenylpropane: Synthesis and characterization
© 2017, Pleiades Publishing, Ltd. Polyurethanes composed of aromatic components are synthesized using the catalytic effect of potassium alcoholates on the reaction of urethane formation occurring with participation of 4,4'-dihydroxy-2,2-diphenylpropane, 4,4'-diphenylmethane diisocyanate, and polyisocyanate, which is a mixture of 4,4'-diphenylmethane diisocyanate and its branched derivatives. In the case of 4,4'-diphenylmethane diisocyanate, segmented polyurethanes with the predetermined length of the rigid block are formed, while the use of polyisocyanate gives rise to framed aromatic polyurethanes. The use of macroinitiators as carriers of potassium alcoholate groups does not cause microphase separation of flexible and rigid segments
Mathematical model of the competition life cycle under limited resources conditions: Problem statement for business community
Present study is devoted to the development of competition life cycle mathematical model in the closed business community with limited resources. Growth of each agent is determined by the balance of input and output resource flows: input (cash) flow W is covering the variable V and constant C costs and growth dA/dt of the agent's assets A. Value of V is proportional to assets A that allows us to write down a first order non-stationary differential equation of the agent growth. Model includes the number of such equations due to the number of agents. The amount of resources that is available for agents vary in time. The balances of their input and output flows are changing correspondingly to the different stages of the competition life cycle. According to the theory of systems, the most complete description of any object or process is the model of its life cycle. Such a model describes all stages of its development: from the appearance ("birth") through development ("growth") to extinction ("death"). The model of the evolution of an individual firm, not contradicting the economic meaning of events actually observed in the market, is the desired result from modern AVMs for applied use. With a correct description of the market, rules for participants' actions, restrictions, forecasts can be obtained, which modern mathematics and the economy can not give. © 2017 Author(s).15-06-04863Present study was carried out under financial support of the Russian Fund of Fundamental Research grant № 15-06-04863 "Mathematical models of local payment system lifecycles"
Investigation of supramolecular organization of polyetherisocyanatesiloxanes
The characteristics of the supramolecular organization of polyetherisocyanatesiloxanes are inferred from measurements of the temperature dependence of the dielectric loss tangent. It is shown that the mutual influence of macromolecular components on the formation of interpenetrating polymer network depends on the prescription and temperature conditions of synthesis. © 2011 Pleiades Publishing, Ltd
Synthesis and properties of novel polyurethanes based on amino ethers of boric acid for gas separation membranes
© The Royal Society of Chemistry. Herein we present the structural and mechanical properties of polyurethanes synthesized from amino ethers of boric acid for gas separation. The polymers were characterized by light scattering methods, conductivity measurements, thermal gravimetric analysis, Fourier transform infrared spectroscopy, and atomic force microscopy. Additionally, the permeability of ammonia and carbon dioxide, as well as the selectivity for their diffusion and resultant impurity are presented. The results illustrate the steric hindrance, resulting in a branched architecture borate formation, leads to intermolecular complexation which may assist the polymer in ammonia diffusion selectivity
Supramolecular architecture of polymers as the basis of obtaining mesoporous polymers
Self-organization and arrangement of supramolecular structures from blockcopolymers are some of the ways used for the development of nanoporous and mesoporous polymers. Herein, reactive olygomers can play the key role in the design of supramolecular arranging of polymers. Optically transparent mesoporuos block-copolymers with adjusted free volume are obtained by the polyaddition of 2,4-toluene diisocyanate (TDI) to anionic macroinitiators. The mechanism of polyaddition of TDI to an anionic macroinitiator in various chemical solvents was studied by infrared spectroscopy. It is established that the reaction of forming polyisocyanate blocks of acetal nature (O-polyisocyanate) and stabilization of end O-polyisocyanate chains are based on the formation of voids in polymer. The formation of voids is conditioned by the geometry of self-organization of block-copolymers containing end potassium-O-polyisocyanates stabilized by crown ether fragments. The formation of urea with the participation of isocyanate groups of ortho-location of TDI is one of the main factors of the stabilization of O-polyisocyanate blocks. The investigation of the polymer sorption properties was carried out by electron spectroscopy. As an adsorbed dye Rhodamine 6G was used. The ability of Rhodamine 6G to sorb depended on the content of the O-polyisocyanate component in the polymer. Mesoporous polymers demonstrated high efficiency as an optically transparent matrix for laser-active media with high radiation stability. Rhodamine 6G in mesoporous polymers retains spectral luminescent properties and generates laser radiation during excitation by the second harmonic of Nd:YAG laser. © 2014 Taylor & Francis
Framed aromatic polyurethanes based on an anionic macroinitiator, 4,4'-diphenylmethane diisocyanate, and 4,4'-dihydroxy-2,2-diphenylpropane: Metal-complex modification
© 2017, Pleiades Publishing, Ltd. Metal complexes are prepared from poly(oxyethylene glycol) and iron(III) chloride and studied as modifiers of framed aromatic polyurethanes. The latter polymers are synthesized on the basis of macroinitiators, 4,4'-dihydroxy-2,2-diphenylpropane, and polyisocyanate, which is a mixture of 4,4'-diphenylmethane diisocyanate and its branched derivatives. The interaction of iron(III) chloride with poly(oxyethylene glycol) is accompanied by redox processes that lead to its degradation and partial reduction of Fe(III) to Fe(II). Aromatic polyurethanes are modified in the concentration range of metal complexes from 0.5 to 20%. At a concentration of metal complexes of 4–7%, the polymer shows high mechanical characteristics and excellent thermal stability. The framed structure of aromatic polyurethanes hampers the effective contacts of coordinately bonded Fe atoms that are present in various oxidation states
Immobilization of organic reagents on optically transparent mesoporous polymers and its analytical use
© 2015 Pleiades Publishing, Ltd. Sorption of organic reagents Arsenazo III and 1-(2-pyridylazo)-2-naphthol onto optically transparent mesoporous polymers prepared from macroinitiators and toluene 2,4-diisocyanate was studied. The possibility of preconcentration of organic reagents and their complexation with Cu(II) and Ca(II) ions in the polymer pore voids was demonstrated. Experiments on spectrophotometric analysis using the polymeric support showed that the lower limit of determination was 20 μg mL-1 for Ca(II) and 2 μg mL-1 for Cu(II)
Framed aromatic polyurethanes based on an anionic macroinitiator, 4,4'-diphenylmethane diisocyanate, and 4,4'-dihydroxy-2,2-diphenylpropane: Metal-complex modification
© 2017, Pleiades Publishing, Ltd. Metal complexes are prepared from poly(oxyethylene glycol) and iron(III) chloride and studied as modifiers of framed aromatic polyurethanes. The latter polymers are synthesized on the basis of macroinitiators, 4,4'-dihydroxy-2,2-diphenylpropane, and polyisocyanate, which is a mixture of 4,4'-diphenylmethane diisocyanate and its branched derivatives. The interaction of iron(III) chloride with poly(oxyethylene glycol) is accompanied by redox processes that lead to its degradation and partial reduction of Fe(III) to Fe(II). Aromatic polyurethanes are modified in the concentration range of metal complexes from 0.5 to 20%. At a concentration of metal complexes of 4–7%, the polymer shows high mechanical characteristics and excellent thermal stability. The framed structure of aromatic polyurethanes hampers the effective contacts of coordinately bonded Fe atoms that are present in various oxidation states