Transients in a circulating fluidized bed boiler

Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for calculating the time constants of unsteady processes are obtained. © 2013 Pleiades Publishing, Inc

Generation and reduction of nitrogen oxides in firing different kinds of fuel in a circulating fluidized bed

The processes through which nitrogen oxides are generated and reduced in the course of firing different kinds of fuel in a circulating fluidized bed are addressed. All experimental studies were carried by the authors on their own laboratory installations. To construct a model simulating the generation of nitrogen oxides, the fuel combustion process in a fluidized bed was subdivided into two stages: combustion of volatiles and combustion of coke residue. The processes through which nitrogen oxides are generated and reduced under the conditions of firing fuel with shortage of oxygen (which is one of efficient methods for reducing nitrogen oxide emissions in firing fuel in a fluidized bed) are considered. © 2013 Pleiades Publishing, Inc

Consumer behavior in the context of global economic transformations

Transition to alternative methods of service and omnichannelity allows the buyer to be more demanding and discerning. The current trends in the development of retail trade caused by globalization forcing the redistribution of consumer budget from a high-margin offline cart to a low-margin online cart that instigate not only the necessity of transformations in management, but also the study of consumer behavior. Dynamical development of trading innovative technologies allows the buyers not only to expand the range of their aspiration, but also to become participants in the cognitive and learning processes, where the acquirement of the new experience and emotions influences the traditional ways of making purchases on offline trading. To remain competitive, retailers should not only provide high-quality goods and services at the best prices, but also to contribute to their high-quality and get-to-able supply. Most purchasing decisions are made "by feel", that contradict to the theories of rational choice and theories using marketing concepts. The article gives views on the factors and criteria that determine consumers behavior in online and offline trade.peer-reviewe

Influence of a binder on the electrochemical behaviour of Si/RGO composite as negative electrode material for Li-ion batteries

Received: 02.12.2020. Accepted: 21.12.2020. Published:30.12.2020.A composite consisting of silicon nanoparticles and reduced graphene oxide nanosheets (Si/RGO) was studied as a promising material for the negative electrode of lithium-ion batteries. Commonly used polyvinylidene fluoride (PVdF) and carboxymethyl cellulose (CMC) served as a binder. To reveal the influence of the binder on the electrochemical behaviour of the Si/RGO composite, binder-free electrodes were also prepared and examined. Anode half-cells with composites comprising CMC as a binder demonstrated the best properties: capacity over 1200 mAh·g–1, excellent cycling performance and good rate capability up to 1.0C.This work was performed with financial support from the Ministry of Science and Higher Education of Russian Federation, project ID RFMEFI60419X0235

Внутриклеточные сигнальные системы в эпителии и гладких мышцах воздухоносных путей

A role of intracellular signal systems for the regulation of the epithelium and smooth muscle relations in the respiratory tract as well as interaction of the secondary agents participating in regulation of the epithelium relaxing factor production with the consideration of its effect on the smooth muscles were studied. It has been determined that the relaxing factor production by the epithelium is a calcium dependent process which is regulated by the calmoduline type Ca2+ binding proteins and the С proteinkinase. The mechanisms of ERF relaxing effect on smooth muscles depend on the interaction of two cyclic nucleotides (cAM P and cGM P) with the phosphodiesterase involvement.В работе изучалась роль внутриклеточных сигнальных систем в регуляции эпителиальногладкомышечных взаимоотношений в респираторном тракте, взаимодействие вторичных посредников, участвующих в регуляции выработки эпителиального релаксирующего фактора (ЭРФ) и реализации его эффектов на гладкие мышцы. Установлено, что продукция релаксирующих факторов эпителием является кальцийзависимым процессом и регулируется при участии кальмодулинподобных Са2+ -связывающих белков и протеинкиназы С. Механизмы релаксирующего эффекта ЭРФ на гладкие мышцы связаны со взаимодействием двух циклических нуклеотидов —  цАМФ и цГМФ, осуществляющимся при участии фосфодиэстеразы

Морфологические особенности и механизмы регуляции тонуса стенки легочных артерий

Morphological features of pulmonary artery (PA) wall in rabbits and mechanisms of its cholinergic, histaminergic and adrenergic regulation were investigated. The PA structure in its upper part is of a blended type with light predominance of elastic elements and while branching it transforms to a muscular type.A two-component dose dependent character is a peculiarity of the segment PA cholinergic regulation. A low-threshold component of relaxing action of pilocarpine has the endothelium-dependent origin. An important feature of PA histaminergic regulation is a direct contractile effect of histamine that is not inherent to the systemic circulation. The endothelium inhibits histamin-induced contraction of PA smooth muscles (SM). The basic feature of the PA adrenergic regulation are beta-adrenergic contractile effects on SM of the vascular wall. Activation of the cAMP-dependent signalling system in PA SM is able to cause constriction. So, the determined features of the PA tone regulation can be of great clinical and physiological significance.Изучены морфологические особенности стенки легочных артерий (ЛА) кроликов и механизмы холинергической, гистаминергической и адренергической регуляции ее тонуса. В верхних отделах ЛА кроликов имеет смешанный тип строения с небольшим преобладанием эластических элементов, а по мере ветвления превращается в сосуд мышечного типа.Особенностью холинергической регуляции сегментов ЛА является двухкомпонентный характер дозовой зависимости. При этом низкопороговый компонент расслабляющего действия пилокарпина имеет эндотелийзависимую природу. Важной особенностью гистаминергической регуляции тонуса ЛА является прямой сократительный эффект гистамина, что не присуще сосудам большого круга. Эндотелий оказывает угнетающее действие на гистаминергическое сокращение гладких мышц (ГМ) стенки ЛА. Принципиальной особенностью адренергической регуляции тонуса ЛА являются P-адренергические контрактильные эффекты на ГМ сосудистой стенки. Активация цАМФ-зависимой сигнальной системы в ГМ ЛА способна оказывать констрикторный эффект. Выявленные особенности регуляции тонуса ЛА могут иметь существенное клинико-физиологическое значение