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Abstract

The economics of an ORC system is strictly linked to thermodynamic properties of the working fluid. A bad choice of working fluid could lead to a less efficient and expensive plant/generation unit. Some selection criteria have been put forward by various authors, incorporating thermodynamic properties, provided in literature but these do not have a general character. In the paper a simple analysis has been carried out which resulted in development of thermodynamic criteria for selection of an appropriate working fluid for subcritical and supercritical cycles. The postulated criteria are expressed in terms of non-dimensional numbers, which are characteristic for different fluids. The efficiency of the cycle is in a close relation to these numbers. The criteria are suitable for initial fluid selection. Such criteria should be used with other ones related to environmental impact, economy, system size, etc. Examples of such criteria have been also presented which may be helpful in rating of heat exchangers, which takes into account both heat transfer and flow resistance of the working fluid.

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Authors and Affiliations

Dariusz Mikielewicz
Jarosław Mikielewicz
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Abstract

The work presented here, concentrates on experimental surface roughness analysis in the milling of hardened steel using a monolithic torus mill. Machined surface roughness with respect to milling process dynamics has been investigated. The surface roughness model including cutter displacements has been developed. Cutting forces and cutter displacements (vibrations) were measured in order to estimate their quantitative influence on Ra and Rz parameters. The cutter displacements were measured online using a scanning 3D laser vibrometer. The influence of cutting speed vc on surface roughness parameters (Ra, Rz) was also studied. The research revealed that real surface roughness parameters are significantly higher than those calculated on the basis of a kinematic-geometric basic model, and their values are strongly dependent on dynamic cutter displacements.

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Authors and Affiliations

Szymon Wojciechowski
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Abstract

The paper presents a method of measuring the angle of rotation and twist using a tilted fibre Bragg grating

(TFBG) periodic structure with a tilt angle of 6◦, written into a single-mode optical fibre. It has been shown

that the rotation of the sensor by 180◦ causes a change in the transmission coefficient from 0.5 to 0.84 at

a wavelength of 1541.2 nm. As a result of measurements it was determined that the highest sensitivity can

be obtained for angles from 30◦ to 70◦ in relation to the basic orientation. The change in the transmission

spectrum occurs for cladding modes that change their intensity with the change in the polarization of light

propagating through the grating. The same structure can also be used to measure the twist angle. The

possibility of obtaining a TFBG twist by 200◦ over a length of 10 mm has been proved. This makes it

possible to monitor both the angle of rotation and the twist of an optical fibre with the fabricated TFBG.

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Authors and Affiliations

Sławomir Cięszczyk
Piotr Kisała
Krzysztof Skorupski
Patryk Panas
Jacek Klimek

Authors and Affiliations

Jan Surman
Alexander Dmitriev
Riccardo Nicolosi
Dietlind Hüchtker
Monika Wulz
Karl Hall
Bernhard Kleeberg
Kornelia Kończal
Katherine Lebow
Emilia Plosceanu
Joanna Wawrzyniak
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Abstract

This article takes up Adam Dziadek’s somatic approach to literature to explore the theme of erotic experience in two poems by Jarosław Iwaszkiewicz, ‘L’amour Cosaque’ and ‘Amore profane’. With the help of inputs from gender studies and the contemporary theories of the subject it has been possible to profi le the ‘I’ of the poems as a deeply fragmented and sexually ambiguous subject, and, upon the evidence of the elusive autobiographical details woven into the text, as a subject suspended in a liminal space, between the real and the fi ctive world. After analyzing the body represented in the text, both perfect and decrepit, as well as traces of the poet’s carnality that interfere with the text and the reader’s sense of his own soma the article arrives at the following conclusion: in Jarosław Iwaszkiewicz’s lyrics the body seems to project its impressions and experiences onto reality, thus blurring the border between the inside and the outside.

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Authors and Affiliations

Łukasz Kraj
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Abstract

This article asks the question to what extent Ryszard Nycz’s ambitious project of cultural practice outlined in his book Culture as Verb succeeds in opening up ‘a new form of knowledge’ and thus equipping the humanities with a fresh validity. Nycz takes up the poststructuralist concept of the humanities as a site of alternative or subversive knowledge, founded on the principles of interpretation and textual dispersion, and refocuses it on involvement (participation) and binary oppositions (borders), i.e. human vs. nonhuman, or nature vs. culture as a construct. The article, rather than addressing the issues of involvement and borders (liminality), concentrates instead on the contradictions that Nycz’ s theory gives rise to when applied to history, time and the emergence of subjectivity (identity). There is nothing objectionable about the proposition that temporal change is at the very core of culture, yet its locus must be sought not in the proclamations of individual agents, but in the conceptual ruptures that expose and reveal the boundaries of (collective) consciousness and unconsciousness, i.e. the operation of contingency.

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Authors and Affiliations

Jakub Momro

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