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Number of results: 8
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Abstract

The aim of the article is to present the issue of risk and related management methods, with a particular emphasis on the conditions of investment in energy infrastructure. The work consists of two main parts; the first one is the theoretical analysis of the issue, while the second discusses the application of analysis methods on the example of the investment in an agricultural biogas plant. The article presents the definitions related to the investment risk and its management, with a particular emphasis on the distinction between the risk and uncertainty. In addition, the main risk groups of the energy sector were subjected to an analysis. Then, the basic systematics and the division into particular risk groups were presented and the impact of the diversification of investments in the portfolio on the general level of risk was determined. The sources of uncertainty were discussed with particular attention to the categories of energy investments. The next part of the article presents risk mitigation methods that are part of the integrated risk management process and describes the basic methods supporting the quantification of the risk level and its effects – including the Monte Carlo (MC), Value at risk (VaR), and other methods. Finally, the paper presents the possible application of the methods presented in the theoretical part. The investment in agricultural biogas plant, due to the predictable operation accompanied by an extremely complicated and long-term investment process, was the subject of the analysis. An example of “large drawing analysis” was presented, followed by a Monte Carlo simulation and a VaR value determination. The presented study allows for determining the risk in the case of deviation of financial flows from the assumed values in particular periods and helps in determining the effects of such deviations. The conducted analysis indicates a low investment risk and suggests the ease of similar calculations for other investments.

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Authors and Affiliations

Jakub Kaliński
Józef Paska
Karol Pawlak
Paweł Terlikowski
Dawid Urbanek
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Abstract

The rim of a post-exploitation basin is a particularly dangerous zone for buildings. This is due to the impact of mining on the nearby buildings, which persists even after exploitation activities are finished. The rim of the basin remains constantly deformed. This paper presents numerical analyses of buildings located in Marklowice (Silesian Voivodeship, Poland). They are located in an area that was exploited for mining, above the initial exploitation edge on the rim of the basin. The area of the analysed buildings was geodetically monitored during mining works. The results of the measurements allowed the observation of changes in terrain deformation indicators, together with the determination of the settlement’s final values after the operation was completed. Knowledge of the results enabled the preparation of numerical analyses of buildings with the use of the finite element method (FEM), the purpose of which was to determine the residual stresses in the structures after the end of the exploitation. The results are presented in the form of stress maps, which show changes in the internal forces in buildings left by mining operations. Specific examples are used. Two residential two-storey buildings were analysed; they were built using traditional brick methods, with a single-storey outbuilding. All of the analysed buildings are located in the mining commencement zone, in which the deformation of the surface has not faded away.
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Authors and Affiliations

Leszek Szojda
1
ORCID: ORCID
Łukasz Kapusta
2
ORCID: ORCID

  1. Silesian University of Technology, Department of Structural Engineering, Akademicka 5,44-100, Gliwice, Poland
  2. Kielce University of Technology, Faculty of Environmental Engineering, Geomatics and Renewable Energy, 7 Tysiąclecia Państwa Polskiego Av., 25-314 Kielce, Poland
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Abstract

Thermal augmentation in flat tube of car radiator using different nanofluids has been performed more often, but use of artificial roughness has been seldom done. Artificial roughness in the form of dimple is used in the present research work. Present study shows the impact of dimple shaped roughness and nanofluid (Al2O3/pure water) on the performance of car radiator. The pitch of dimples is kept at 15 mm (constant) for all the studies performed. The Reynolds number of the flow is selected in the turbulent regime ranging from 9350 to 23 000 and the concentration of the nanofluid is taken in the range of 0.1–1%. It has been found that the heat transfer rate has improved significantly in dimpled radiator tube on the expense of pumping power. Furthermore, the heat transfer rate also increases with increase in nanoparticle concentration from 0.1% to 1.0%. The highest heat transfer enhancement of 79% is observed at Reynolds number 9350, while least enhancement of 18% is observed for Reynolds number of 23 000.
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Authors and Affiliations

Robin Kumar Thapa
1
Vijay Singh Bisht
1
Prabhakar Bhandari
2
Kamal Singh Rawat
3

  1. Uttarakhand Technical University, Faculty of Technology, Chakrata Road, Dehradun-248007, Uttarakhand, India
  2. K.R. Mangalam University, Mechanical Engineering Department, Sohna Road, Gurgram-122103, Haryana, India
  3. MIET, Mechanical Engineering Department, Meerut-250005, Uttar Pradesh, India
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Abstract

In line with the principles of modern design a building structure should not only be safe but also optimized. In deterministic optimization, the uncertainties of the structures are not explicitly taken into account. Traditionally, uncertainties of the structural system (i.e. material parameters, loads, dimensions of the cross-sections) are considered by means of partial safety factors specified in design codes. Worth noticing, that optimal structures are sensitive to randomness design parameters and deterministic optimal solutions may lead to reduced reliability levels. It therefore seems natural to extend the formulation of deterministic optimization with the random scatter of parameter values. Such a formulation is offered by robust optimization and reliability-based design optimization. The applicability ofRBDOis strongly dependent on the availability of the joint probability density function.Aformulation of non-deterministic optimization that better adapts to the design realities is robust optimization. Unlike RBDO optimization, this formulation does not require estimation of failure probabilities. In the paper using the examples of steel beams, the authors compare the strengths and weaknesses of both formulations.
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Authors and Affiliations

Paweł Zabojszcza
1
ORCID: ORCID
Urszula Radoń
1
ORCID: ORCID
Piotr Tauzowski
2
ORCID: ORCID

  1. Kielce University of Technology, Faculty of Civil Engineering and Architecture, Al. Tysiaclecia Panstwa Polskiego 7, 25-314 Kielce, Poland
  2. Institute of Fundamental Technological Research Polish Academy of Sciences, Department of Informationand Computational Science, Adolfa Pawinskiego 5B St., 02-106 Warsaw, Poland
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Abstract

The paper describes the political use of symbols of childhood and orphanhood in the current policy of the Russian authorities. At the beginning of the Bolshevik regime, homeless children (bezprizorni) became a subject of interest for the security apparatus organized by F. Dzerzhinsky. At that time, A. Makarenko developed his innovative pedagogical approach. These activities were designed to create a “new Soviet man”. After the collapse of the Soviet Union, Russia again faced the problem of homeless children. After several years, however, children and orphans are now being used as a symbol of vulnerability in the government policy of the Kremlin. As an answer to the so-called “Magnitsky Act”, the Russian authorities implemented the “DimaYakovlev law” prohibiting adoptions of Russian children to the United States. In addition to this, the child as a symbol of innocence and vulnerability is an invariant element in the policy of the Russian authorities. This combines symbolism associated with bravery, dedication and sacrifice, allowing justification of the current political course of power in Russia.

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Authors and Affiliations

Wojciech Siegień
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Abstract

The paper describes a fuel cell based system and its performance. The system is based on two fuel cell units, DC/DC converter, DC/AC inverter, microprocessor control unit, load unit, bottled hydrogen supply system and a set of measurement instruments. In the study presented in the paper a dynamic response of the proton exchange membrane (PEM) fuel cell system to unit step change load as well as to periodical load changing cycles in the form of semi-sinusoidal and trapezoidal signals was investigated. The load was provided with the aid of an in-house-developed electronic load unit, which was fully PC controlled. The apparatus was commissioned by testing the steady-state operation of the module. The obtained efficiency of the fuel cell shows that the test apparatus used in the study provides data in substantial agreement with the manufacturer’s data.

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Authors and Affiliations

Janusz T. Cieśliński
Tomasz Z. Kaczmarczyk
Bartosz Dawidowicz
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Abstract

This study includes hydrologie characteristics of the Potok Toszecki basin area and the results of chemical analysis of water quality of the Potok Toszecki. These investigations were carried out in following periods: from March 1993 till May 1994 and from January 1997 till June 1998. The results of investigations on the chemical parameters of water quality were compared with analysis, carried out in 1976. Under the results of this investigations water quality of the Potok Toszecki - a watercourse, which flows to the Pławniowice Reservoir - was defined and essential factors, connected with character of the basin area have been shown. Classification of several parameters was achieved under the official decree of the ministry of environmental protection from November 5th 1991. On the basis of this classification it was found, that the main risk for the Pławniowice Reservoir are biogenie substances and suspension, inflowing to the Reservoir together with the water of the Potok Toszecki. Improvement of the existing situation will be possible only if firm waste-water managements action will be taken.
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Authors and Affiliations

Maciej Kostecki
Jerzy Kozłowski
Agata Domurad
Bartłomiej Zych
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Abstract

A Polish translation of Book 10 of Quintus of Smyrna’s Posthomerica, whose climactic part treats the deaths of Paris and Oenone. This foreshadows the first Polish translation of the whole of Quintus’ poem since the rendering by Jacek Idzi Przybylski published in Cracow in 1815.
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Authors and Affiliations

Włodzimierz Appel
1
ORCID: ORCID

  1. Katedra Filologii Klasycznej, Uniwersytet Mikołaja Kopernika

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