Two methods for calculating transport parameters in semiconductor superlattices by applying Green’s functions are compared in the paper. For one of the methods, the Wannier functions method, where computations in the complex space and Wannier functions base are required, the Hamiltonian matrix is small in size and its elements depend solely on the energy. For the real space method, as it operates in the floating point domain and uses the Hamiltonian containing the elements dependent both on energy and position, the Hamiltonian matrix is larger in size. The size makes the method computationally challenging. To find the consequences of choosing one of the methods, a direct comparison between the computations, obtained for both methods with the same input parameters, was undertaken. The differences between the results are shown and explained. Selected simulations allowed us to discuss advantages and disadvantages of both methods. The calculations include transport parameters such as the density of states and the occupation functions, with regard to scattering processes where the self-consistent Born approximation was used, as well as the spatial distribution of electron concentration for two superlattices structures. The numerical results are obtained within the non-equilibrium Green’s functions formalism by solving the Dyson and the Keldysh equations.
The article examines the theoretical discussions on the dualism of “form” and “content” in literature and art that took place in Soviet Ukraine in the mid-1920s. The subject is considered in the context of the development of two competitive approaches of study of literature and art — Russian formalism and Marxism. The problem is observed through the comparison of ethical and ideological positions of the modernists and Marxists in Russia and Ukraine in the 1920s.
The following analysis investigates selected properties of the language of the tweets used in the interaction with consumers on English and Polish brand profiles. The analysis examines the structure of tweets, word frequency, as well as the frequency of informal and non-standard language items, language mistakes, the use of emoticons and hashtags. The study contrasts the language used by English and Polish representatives and reveals a number of similarities and differences between the corpora. What the corpora share is a high frequency of conventional politeness acts and language structures reflecting a customer-oriented tone of the interaction. Differences are observed in the frequency and use of informal and non-standard structures, emoticons and hashtags, as well as in the structure and complexity of the tweets. The study indicates a lower formulaicity and a greater individualization of the interaction on the Polish profiles.
The review covers Ruselina Nicolova’s The Bulgarian Grammar. This is a revised version of Bǔlgarska gramatika. Morfologiia (Sofiia 2008) edited in English by Frank & Timme (Berlin 2017). This outstanding achievement is appraised highly by the review author. The review compares the new work with an earlier academic morphology of Bulgarian (Gramatika na sǔvremenniia bǔlgarski knižoven ezik, t. 2: Morfologiia, Sofiia 1983). It concludes that the Grammar of R. Nicolova makes important progress in semantically and functionally oriented type of Bulgarian linguistic description as well as that publication of this study translated to English is important because it provides a widened reception of the work.
The author states that there are in our vocabulary three, and only three, classes of semantic units: a) predicates, i.e. generic concepts – the result of our conceptualization of the world; they represent more than 90% of the vocabulary; b) operators of reference – a small, almost closed set bounding predicates to their concrete denotates; c) proper names, which are by defi nition referentially bound and are object of research of a specialized linguistic discipline. Thus, the main tasks of our grammar are (1) to defi ne and to describe the scope of the grammaticalization in the language in question and (2) to present the semantic classification of predicates, the description of their – bound and/or free – functioning in the text included.
In a series of recent papers we have shown how the continuum mechanics can be extended to nano-scale by supplementing the equations of elasticity for the bulk material with the generalised Young-Laplace equations of surface elasticity. This review paper begins with the generalised Young-Laplace equations. It then generalises the classical Eshelby formalism to nano-inhomogeneities; the Eshelby tensor now depends on the size of the inhomogeneity and the location of the material point in it. The generalized Eshelby formalism for nano-inhomogeneities is then used to calculate the strain fields in quantum dot (QD) structures. This is followed by generalisation of the micro-mechanical framework for determining the effective elastic properties of heterogeneous solids containing nano-inhomogeneities. It is shown that the elastic constants of nanochannel-array materials with a large surface area can be made to exceed those of the non-porous matrices through pore surface modification or coating. Finally, the scaling laws governing the properties of nano-structured materials are given.
The article presents reviews of the European Union regulation on reporting formalities for ships entering the EU ports. It also analyses IMO regulation concerning that matter. Finally, the author exposes the differences between both legal systems and weaknesses of the solutions adopted. In the second part of the article the author discusses the Polish way of the reporting formalities system’s implementation. On the basis of a legal analysis as well as practice of the maritime authorities in Poland, the author finds that the Polish regulations seem to be exemplary.
Formalization of a set of beliefs expressed in one language consists in translating them into sentences of another language. The characteristic property of a good formalization is that the target language is correctly chosen and the translations precisely reflect the meaning of the original sentences. In the paper a formalization of ontology of situations (given by Professor Bogusław Wolniewicz) is discussed. I argue that this is an example of a perfect solution of the problem.
Becoming more and more a multidisciplinary domain of study, the development of research in second language acquisition, and even more visibly in multilingualism, has moved away from its sole focus on cognitive aspects to social-affective dimensions. Consequently, research in these areas makes more extensive use of research methodology characteristic of social sciences. The focus on identity brings together issues of social context and the construction of one’s identity through negotiation of who we are, how we relate to the outside world and how we position ourselves in relation to others (Pavlenko 2001). Language is the main tool in this construction/ negotiation through the acquisition/learning and use of multiple languages. In relation to the development of one’s multilingual identity, the major distinction has to be made between acquiring a language in its natural context (the case of one’s mother tongue or immigration) and learning it in formal contexts. Block (2014) believes that the issue of identity can only be studied in a natural environment of language acquisition, and not in a formal instruction context. This article aims to confi rm or reject the above belief, based on evidence from various studies of bi- and multiple language users and how they perceive their identities and their relation to the languages in their possession. It includes a pilot study of trilingual language learners and their understanding of how the individual languages they know (L1, L2, L3) build their identities and the way they enrich, impoverish or challenge who they see themselves to have been by birth (Gabryś-Barker 2018). The issues discussed relate to external (other people, situations, contexts) and internal identity-building factors (individual affectivity, personality features).
Selected scientific contacts of Jacek Hawranek and Jan Zygmunt with Professor Bogusław Wolniewicz in the period from the end of the 1980s to the beginning of the 21st century are presented in this essay. They concerned the algebraic aspects of the ontology of situations and from one moment – one only question that was posed by Wolniewicz in his note A question about join-semilattices (Bulletin of the Section of Logic, 19/3, 1990, pp. 108–108), and resulted in the Hawranek & Zygmunt paper Wokół pewnego zagadnienia z dziedziny półkrat górnych z jednością (“Some comments on a question about semilattices with unit”) (Acta Universitatis Wratislaviensis 1445, Logika 15 (1993), pp. 59–68) containing an answer to Wolniewicz’s question. The Hawranek & Zygmunt paper is reprinted below, and the essay might be also treated as a kind of an analytical and historical introduction to it. The story of contacts Wolniewicz – Hawranek & Zygmunt has been told with the help of the preserved correspondence between the three persons. In his letters Professor Wolniewicz appears as a passionate researcher, open to discussion, ready to share his research successes and difficulties with others.
The aim of the paper is to provide hints on how to read Acemoglu and Robinson’s institutional hypothesis. First, we recall the meaning of their inclusive and extractive institutions. Then, we classify and compare the concept to certain approaches present in development economics. Additionally, we outline the perspective of historical research of institutions, raising the approach of historical natural experiments and comparative methods. We claim in the paper that to understand Acemoglu and Robinson’s institutional hypothesis and their strong rejection of other hypotheses on economic development one has to turn back to the basic notion of institutions. We argue that the authors of Why Nations Fail are focused on considering formal institutions only, which impoverishes the research perspective presented in that book.
The national power industry is based primarily on its own energy mineral resources such as hard and brown coal. Approximately 80% of electrical energy production from these minerals gives us complete energy independence and the cost of its production from coal is the lowest in comparison to other sources. Poland has, for many decades had vast resources of these minerals, the experience of their extraction and processing, the scientific-design facilities and technical factories manufacturing machines and equipment for own needs, as well as for export. Nowadays coal is and should be an important source of electrical energy and heat for the next 25–50 years, because it is one of the most reliable and price acceptable energy sources. This policy may be disturbed over the coming decades due to the depletion of active resources of hard and brown coal. The conditions for new mines development as well as for all coal mining sector development in Poland are very complicated in terms of legislation, environment, economy and image. The authors propose a set of strategic changes in the formal conditions for acquiring mining licenses. The article gives a signal to institutions responsible for national security that without proposed changes implementation in the legal and formal process it, will probably not be possible to build next brown coal, hard coal, zinc and lead ore or other minerals new mines.
In this article I present the problem of identity of objects (that persist in time and space) and their identification (also in time and space, when these objects persist and change their location) indicated in the title of the paper. I therefore present an outline of P.F. Strawson’s proposal, but also a purely formal approach that can be found in formal sciences (logic and mathematics). In the final part I give some ontological solution to Strawson’s research. It is a solution based on formal considerations within the so-called ontologically oriented versions of modal and temporal logics, which I proposed in my book Indywidua. Idee. Pojęcia (2008).
Bogusław Wolniewicz, inspired by his formal ontology of situations, has put forward a question on semilattices with a unit (A question about joinsemilattices, Bulletin of the Section of Logic 19/3, 1990). The present paper is entirely devoted to this problem in the formulation given by Wolniewicz. First, the meaning of the question is analyzed and its lattice-theoretical and Boolean algebraic contents are exhibited. Second, set-theoretical and topological counterparts of the question are formulated and commented upon.