The objective of the work presented in this paper was to apply a method for handling two-phase reacting flow for prediction of pulverized coal combustion in large-scale boiler furnace and to assess the ability of the model to predict existing power plant data. The paper presents the principal steps and results of the numerical modeling of power boiler furnace with tangential disposition of the burners. The computational fluid dynamics/computational thermal analysis (CFD/CTA) approach is utilized for creation of a three-dimensional model of the boiler furnace, including the platen superheater in the upper part of the furnace. Standard k-e model is employed for description of the turbulent flow. Coal combustion is modeled by the mixture fraction/probability density function approach for the reaction chemistry, with equilibrium assumption applied for description of the system chemistry. Radiation heat transfer is computed by means of the simplified P-N model, based on the expansion of the radiation intensity into an orthogonal series of spherical harmonics. Some distinctive results regarding the examined boiler performance in capacity range between 65 and 95% are presented graphically. Comparing the simulation predictions and available site measurements concerning temperature, heat flux and combustion efficiency, a conclusion can be drawn that the model produces realistic insight into the furnace processes. Qualitative agreement indicates reasonability of the calculations and validates the employed sub-models. After the validation and verification of the model it was used to check the combustion efficiency as a function of coal dust sieve characteristics, as well as the impact of burners modification with introduction of over fire air ports to the appearance of incomplete combustion, including CO concentration, as well as to the NOx concentration. The described case and other experiences with CFD/CTA stress the advantages of numerical modeling and simulation over a purely field data study, such as the ability to quickly analyze a variety of design options without modifying the object and the availability of significantly more data to interpret the results. .
Small heat shock proteins (sHsps) are an evolutionarily conserved class of ATP-independent chaperones that form the first line of defence during proteotoxic stress. sHsps are defined not only by their relatively low molecular weight, but also by the presence of a conserved α-crystallin domain, which is flanked by less conserved, mostly unstructured, N- and C-terminal domains. sHsps form oligomers of different sizes which deoligomerize upon stress conditions into smaller active forms. Activated sHsps bind to aggregation-prone protein substrates to form assemblies that keep substrates from irreversible aggregation. Formation of these assemblies facilitates subsequent Hsp70 and Hsp100 chaperone-dependent disaggregation and substrate refolding into native species. This mini review discusses what is known about the role and place of bacterial sHsps in the chaperone network.
In response to the last financial crisis new institutional reforms were implemented. The aim for these reforms is to save and secure the functioning of markets in financial instruments. It seems though that these efforts lack the clarity of the basic notion, which is the term "institution". This weakness my cause interpretational problems on both theoretical and practical level. The aim of this article is to clarify the understanding of the notion of "institution" in finance. One of ways to achieve this goal is to present the institutional structure of the market in financial instruments, to specify the characteristics of both individual institutions and the whole environment in which they act. And, lastly, to outline an institutional transformation process which is driven by innovations. The classification of institutions is also proposed. As a result of analysis, following types of institutions are singled out: institutions in a broad meaning (established through institutional contracts), institutions in a narrow sense (norms and social rules). Additionally, the formal and informal institutions are distinguished.
In response to the outbreak of the global financial crisis, central banks and regulatory and supervisory bodies undertook a number of measures to mitigate the effects of the crisis and minimize its impact in the future. Changes were also made in Poland in 2009-2016, among others, in the areas of monetary policy (since 2015 interest rates have been at historically low levels), prudential regulations, the functioning of the deposit guarantee scheme, structured bankruptcy, and the so-called bank tax. The aim of this study is to attempt to answer the question of how changes in monetary policy and the regulatory environment affected the efficiency of banks in Poland. The study period was the years 2009-2016 and the sample consisted of the seventeen largest banks, divided into two groups. The division criterion was the value of the solvency ratio as a measure of a bank's capital strength (the limit value adopted was the total capital ratio of 9%). Based on the research conducted, it can be argued that despite the fact that banks with lower capital ratios still achieve higher profitability on banking operations, better capitalized banks have significantly compensated for the gap by further improving the return on assets compared to less capitalized institutions.
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