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Abstract

In knowledge based economy, which actually reflects the knowledge oriented modern society, career development of its members becomes the key factor, same as investing in career “portfolio”. In the article a career construct is invoked as an individual’s property considering individual career choices, individual career development planning and monitoring strategies. When addressing career related matter, one cannot overlook the issue of subjective meaning given to a career in the context of satisfactory outcome and success achievement experienced by the subject. Cognitively interesting issue addressed by the author are the results of research into evaluation of one’s own chances to succeed from the perspective of university students who are in the transition period from academic education to entering a job market.

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Authors and Affiliations

Agnieszka Cybal-Michalska
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Abstract

If the most parsimonious behavioral model between an observed behavior, Y, and some factors, X, can be defined as f(Y|X1, X2), then fx1 will measure the impact in behavior of a change in factor X1. Additionally, if fx1x2 ≠ 0, then the impact in behavior of a change in factor X1 is qualified, or moderated by X2. If this is the case, X2 is said to be a moderating variable and fx1x2 is said to be the moderating effect. When Y is modeled via a logistic regression, the moderation effect will exist regardless of whether the index function of the logit specification includes a moderation term or not. Thus, including a moderation terms in the index function will help the researcher more precisely qualify the moderation effect between X1 and X2. The question that naturally arises is whether the researcher must include the moderation term or not. In this document, we provide the conditions in which moderation terms will naturally arise in a logistic regression and introduce some modeling guidelines. We do so by introducing a general framework that nests models with no moderation terms in three scenarios for the independent variables, commonly found in applied research.

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Authors and Affiliations

Alfredo A. Romero
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Abstract

The aim of this work was to determine the influence of liming on the process of pyrolysis. Three samples of sludge from two wastewater treatment plants were selected for this study on pyrolysis: sludge without liming and limed sludge from the Central Wastewater Treatment Plant in Ostrava and sludge from the Wastewater Treatment Plant in Sviadnov. The samples had different content of calcite (CaCO3). The limed sludge contained 7% of CaCO3, sludge without liming 3.8% and sludge without liming from WWTP Sviadnov contained 0.5% of calcite. The results of laboratory pyrolysis proved that limed sludge released the maximum amount of carbon - 55.46 %, while sludge without liming from WWTP Sviadnov released only 48.92%. Calcite produces during its decomposition CaO and the product influences the pyrolysis process because it supports cracking of volatile organic compounds

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Authors and Affiliations

Adéla Čížková
Dagmar Juchelková
Helena Raclavská
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Abstract

This paper describes the theoretical background of electromagnetic induction from metal objects modelling. The response function of a specific case of object shape - a homogenous sphere from ferromagnetic and non-ferromagnetic material is introduced. Experimental data measured by a metal detector excited with a linearly frequency-swept signal are presented. As a testing target various spheres from different materials and sizes were used. These results should lead to better identification of the buried object.

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Authors and Affiliations

Josef Vedral
Jakub Svatoš
Pavel Fexa
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Abstract

This paper presents the results of research on high performance concretes (HPC) modified by theaddition of polypropylene fibres
(PP fibres). The scope of the research was the measurement of theresidual transport properties of heated and recooled concretes: gas permeability and surface waterabsorption. Seven types of concrete modified with fibrillated PP fibres were tested. Three lengths: 6,12 and 19 mm and three amounts of fibres: 0, 0.9 and 1.8 kg/m3 were used. The research programmewas designed to determine which length of fibres, used in which minimum amount, will, after thefibres melt, permit the development of a connected network and pathway for gases and liquids.

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Authors and Affiliations

I. Hager
T. Tracz
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Abstract

In order for the ultimate state methods to be applied in dimensioning of the load-bearing elements in a conveyance, it is required that their design loads during their normal duty cycle and under the emergency braking conditions should be first established. Recently, efforts have been made to determine the interaction forces between the shaft steelwork and the conveyance under the normal operating condition [1,2]. Thus far, this aspect has been mostly neglected in design engineering. Measurement results summarised in this paper and confronted with the theoretical data [3] indicate that the major determinant of fatigue endurance of conveyances is the force acting horizontally and associated with the conveyance being hoisted in relation to the vertical force due to the weight of the conveyance and payload.
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Bibliography

[1] F . Matachowski, PhD thesis, Opracowanie kryteriów projektowania wybranych elementów nośnych naczynia wydobywczego. AGH University of Science and Technology, Kraków, Poland (2011).
[2] S. Wolny, F. Matachowski, Operating Loads of the Shaft Steelwork – Conveyance System dne to Ranchon Irregularities of the Guiding Strings. Arch. Min. Sci. 55 (3), 589-603 (2010).
[3] S. Wolny, Wybrane problemy wytrzymałościowe w eksploatacji górniczych urządzeń wyciągowych. Monografia. Problemy Inżynierii Mechanicznej i Robotyki, AGH, Nr 20, Kraków (2003).
[4] M. Płachno, Metoda dynamiczna badań stanu zmienności naprężeń w cięgnach naczyń wyciągowych powodowanego nierównościami torów prowadzenia. In monograph: Transport szybowy 2007, Wydawnictwo KO MAG, Gliwice, II , 51-60 (2007).
[5] M. Płachno, Mathematical model of transverse vibrations of a high-capacity mining skip due misalignment of the guiding tracks in the hoisting shaft. Arch. Min. Sci. 63 (1), 3-26 (2018).
[6] D . Fuchs, H. Noeller, Untersuchungen an Haupttraggliedern hochbeanspruchter Fördermittel. Sonderabdruck aus Glückauf 124 (9), 512-514 (1998).
[7] M. Płachno, Z. Rosner, Możliwości wczesnego wykrywania procesów zmęczeniowych w cięgnach naczyń wyciągów górniczych. Bezpieczeństwo Pracy i Ochrona Środowiska w Górnictwie, Wydanie Specjalne, 241-246 (1997).
[8] S. Wolny, Interactions in mechanical systems due to random inputs on the example of a mine hoist. International Education & Research Journal, Engineering 1 (5), 70-74 (2015).
[9] S. Wolny, Displacements in mechanical systems due to random inputs in a mine hoist installation. Engineering Transactions 65 (3), 513-522 (2017).
[10] S. Wolny et al., Research work, Opracowanie kryteriów oceny konstrukcji nośnej naczyń górniczych wyciągów szybowych w aspekcie przedłużenia okresu bezpiecznej eksploatacji. Katedra Wytrzymałości Materiałów i Konstrukcji, AGH University of Science and Technology, Kraków (2003) (unpublished).
[11] A . Pieniążek, J. Weiss, A. Winiarz, Procesy stochastyczne w problemach i zadaniach. Wydawnictwo Politechniki Krakowskiej, Kraków (1999).
[12] V.A. Sretlickij, Slucajnye kolebanija mechaniceskich system. Moskva: Masinostroenie (1976).
[13] S. Wolny, Loads experienced by load-bearing components of mine hoist installations due to random irregularities and misalignments of the guide strings. Journal of Machine Construction and Maintenance 3 (110), 79-86 (2018).
[14] S. Wolny, S. Badura, Wytrzymałość cięgien nośnych górniczego naczynia wydobywczego. Journal of Civil Engineering, Environment and Architecture 34 (64), 149-158 (2017).
[15] S. Kawulok, Oddziaływanie zbrojenia szybu na mechanikę prowadzenia naczynia wyciągowego. Prace GIG, Katowice (1989).
[16] Przepisy górnicze „Rozporządzenie Rady Ministrów z dnia 30 kwietnia 2004 r. w sprawie dopuszczenia do stosowania w zakładach górniczych (Dz.U. Nr 99, poz. 1003 z 2005 r. Nr 80, poz. 695 oraz z 2007 r. Nr 249, poz. 1853, pkt 1.2 Naczynia wyciągowe” (2004).
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Authors and Affiliations

Stanisław Wolny
1
ORCID: ORCID

  1. AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Krakow, Poland
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Abstract

A probable risk for different diseases has been reported due to exposure of peoples living in the vicinity of electrical substations and electrical workers. The aim of this paper is to examine and reduce the induced current density due to the power system field acting on human beings in the working environment, by using the spheroidal calculation model. The results obtained by means of computer programs developed by the author in the MATLAB environment are compared with the limit values given by the International Committee on Non-Ionizing Radiation Protection (ICNIRP) for demonstrating the degree of danger due to the induced current and have a certain guidance function for worker’s health to ensure their safety.

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Authors and Affiliations

Manel Bidi

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