Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 8
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

Lasers emitting mid-infrared (MIR) beams have become indispensable for spectroscopy, free space communication or remote security measures. To the one of the most promising families of the lasers suitable for these applications certainly belongs a group of the Quantum Cascade Lasers (QCL). However, among the conditions they must satisfy there is a high enough radiance of the beam they emit. Radiance depends in a complicated way on the laser output power and optical quality of the laser beam. This paper has been devoted to a description and a short analysis of the factors that decide about radiance of so far developed QCLs. Literature concerning both single devices and QCL arrays operating in beam combining systems have been examined and results described. The survey may be useful for estimation of how far the QCLs have come of age.

Go to article

Authors and Affiliations

B. Mroziewicz
E. Pruszyńska-Karbownik
Download PDF Download RIS Download Bibtex

Abstract

We are observing an increase in development activity of the cities with poviat rights nowadays. It is visible especially in the area of obtaining European funds, financial policy, infrastructure or entrepreneurship. Those matters, especially experience of cities with poviat rights as the main beneficiaries became an interesting research area now. The aim of the article is to assess the competitiveness and development level of the cities with poviat rights in voivodships of Eastern Poland. For the purposes of this article, a synthetic measure has been used. Taking into account the availability and comparability of data as well as statistical criteria, the variables describing: financial situation, economy and infrastructure in the system of cities with poviat rights in voivodships of Eastern Poland were adopted. Data from the Local Data Bank of the Central Statistical Office for 2008, 2012 and 2016 were the main source of the article.

Go to article

Authors and Affiliations

Andrzej Pawlik
Download PDF Download RIS Download Bibtex

Abstract

Discourse Completion Test (DCT) became a very popular research instrument after the publication of the infl uential Blum-Kulka & Olshtain’s (1984) paper titled “Requests and apologies: a cross-cultural study of speech act realization patterns (CCSARP)”. Hundreds and thousands of papers employing the data collection instrument, originally developed by Blum-Kulka in 1982, have been published since then, and the controlled elicitation procedure has left a very important mark on the way in which speech acts have been studied cross-culturally. DCT has its strong supporters as well as pronounced enemies, but its contribution to the development of the fi eld cannot be questioned. The paper presents an overview of the advantages and disadvantages of the data collection tool, as well as a synthesis of the most important fi ndings which it has managed to yield so far. Major directions of research are summarized and possible future developments outlined.
Go to article

Authors and Affiliations

Adam Wojtaszek
Download PDF Download RIS Download Bibtex

Abstract

The analyzed heat accumulator is a key element in a hybrid heating system. In this paper, analytical and numerical models of the ceramic heat accumulator are presented.The accuracy of finite difference methods will be assessed by comparing the results with those obtained from the exact analytical solution.

Go to article

Authors and Affiliations

Dawid Taler
Piotr Cisek
Download PDF Download RIS Download Bibtex

Abstract

Mixing of granular materials is unquestionably important. Mixing solids is common in industrial applications and frequently represents a critical stage of the processes. The effect of mixing determines the quality of the products. Achieving a gas or liquid mixture ideally homogeneous in terms of composition in the case of dissolving components is not that difficult, while in case of granular materials that usually differ in sizes and densities, obtaining a homogenous mixture is practically impossible. The aim of the paper is to present the kinetics of mixing of a multicomponent, nonhomogeneous granular mixture. For the first time in mixing of granular materials, a reference has been made to the terminology used in kinematics of fluid mixtures to determine the state of the mixture: turbulent or laminar. By means of statistical analysis the mixing process was divided into two stages. The initial phase of the process was called the stage of turbulent changes, due to large differences in the quality of the observed mixtures; the final step of the process was called the stage of laminar, stable changes, where further mixing did not result in a significant improvement in quality. The research was conducted in industrial conditions in a two-tonne mixer.

Go to article

Authors and Affiliations

Jolanta B. Królczyk
Download PDF Download RIS Download Bibtex

Abstract

The article deals with one of the most pressing topics in bioethics, namely the attitude to abortion. The author focuses on the interpretation of this practice as a kind of conflict between a woman and the fetus that she gestates (this conflict concerns women’s rights and duties to the fetus, its interests, and the moral status of the fetus in general). Considering several variants of arguments which protect women’s right to abortion (primarily utilitarian arguments based on analogy), the author tries to identify the structure of argumentation. Finally, she presents her own argument against the practice of terminating pregnancy.

Go to article

Authors and Affiliations

Kateryna Rassudina
Download PDF Download RIS Download Bibtex

Abstract

The paper formulates several critical observations about the official (established by Polish legal statutes) rules of evaluation scientific publications. These rules are based on so-called parameterization, that is, ascription of points to papers and books published by scientists. The criticism is made from the point of view of the humanities and social sciences, although some assertions have a more general character. Although the author shares the opinion that evaluation of science is necessary, he points out several disadvantages of parameterization. One of them consists in the fact that the ascription of points to publications uses a relatively weak scale, that is, based on the ordering relation. This feature essentially limits the range of mathematical operations admissible to results of measuring in such a way. This situation results in conventional character of parameterization, contrary to expectations that it successfully display the real value of scientific achievements. The paper illustrates this problem by concrete examples as well as shows that parameterization makes possible pathological cases stemming from political and world-view preferences.
Go to article

Authors and Affiliations

Jan Woleński
1
ORCID: ORCID

  1. Wyższa Szkoła Informatyki i Zarządzania w Rzeszowie
Download PDF Download RIS Download Bibtex

Abstract

This article analyses a hierarchical structure of academia within two academic social media networking sites, i.e. Academia.edu and ResearchGate. In this study, I investigate profiles (in these two services) of all academic staff members of Adam Mickiewicz University in Poznań (N = 2661). I use the concept of prestige to analyse whether the hierarchical structure of academia is being reproduced in analysed services. Since prestige is an unobservable construct, I use two indicators to measure it: the number of followers and the number of views. My findings show that the hierarchical structure differs between Academia.edu and Research- Gate. While the structure of ResearchGate is explicitly hierarchical in reference to degrees of the researchers (a higher degree is related to a higher value of the prestige indicators), the structure of Academia.edu resembles a reversed pyramid (a higher degree is related to a lower value of the prestige indicators). The article concludes with a discussion concerning possible causes of differences between services in terms of reproducing the hierarchical structure. Moreover, I provide potential implications of the results as well as the justification of the necessity of using the concept of prestige to determine hierarchical structure of academia.

Go to article

Authors and Affiliations

Kinga Ciereszko

This page uses 'cookies'. Learn more