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Number of results: 37
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Abstract

When one observes an ant colony, it probably seems like an efficient and harmonious community devoid of quarrels and conflicts. Nothing could be further from the truth. The world of ants, it turns out, is full of animosities. For example, there is friction between the queen and the workers over the gender of the offspring, or among workers themselves about laying unfertilized eggs. There are also other hostilities, for instance, between a colony's rightful inhabitants and any unwanted guests.
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Authors and Affiliations

Magdalena Witek
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Abstract

Mrowisko. Kiedy patrzy się na nie z boku, wydaje się, że wszystko w nim działa sprawnie i harmonijnie, i nie ma czasu na niepokoje i kłótnie. Tymczasem w kopcu mrówek istnieje wiele konfliktów. Na przykład między królową a robotnicami o stosunek płci płodnego potomstwa czy między siostrami robotnicami o składanie niezapłodnionych jaj. Są też innego rodzaju spory - choćby między prawowitymi mieszkańcami a ich niechcianymi gośćmi.
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Authors and Affiliations

Magdalena Witek
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Abstract

The article is a review of the book by Natalie Zemon Davis Slaves on Screen. Film and Historical Vzsion, Cambridge Mass. 2000.
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Authors and Affiliations

Piotr Witek
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Abstract

The article presents a dispute on problems connected with the shape and condition of contemporary science. The starting point is provided by the Author's criticism of two cultural formations (postmodernism and religions fundamentalism) based on his own paradigm of enlighted rationalistic fundamentalism. The Author discusses with Ernest Gellner's suggestions, presents a different, constructive interpretation of competing paradigms.
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Authors and Affiliations

Piotr Witek
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Abstract

The article deals with the philosophical, epistemological and methodological issues of the contemporary debate on historical policy which has taken place in recent years in Poland between historians, philosophers, politicians and columnists.
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Authors and Affiliations

Piotr Witek
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Abstract

The article is a polemics with some traditional concepts of theories of a historical source. The Author of the article takes Marek Henrykowski's assumption of a film being a historical source as a departing point for his own vision of a metaphor of a source and further discussion with some of Hendrykowski's concepts.
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Authors and Affiliations

Piotr Witek
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Abstract

Ewa Borzęcka's film Arizona presents contemporary life in a post-collectivised village. This film is an excuse for the author to wander into world of audio-visual historical narrative and the ethic implications of it.
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Authors and Affiliations

Piotr Witek
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Abstract

The article polemizes with traditional interpretations of a certain phenomenon of culture - the conspiracy theory. The point of reference is provided by Daniel Pipes' analysis of it. Referring in a critical way to the American historian's views, the Author suggests his own, culture oriented view on the notion of conspiracy and the theory of it.
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Authors and Affiliations

Piotr Witek
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Abstract

The aim of this work is to examine the impact of the hydrogen blended natural gas on the linepack energy under emergency scenarios of the pipeline operation. Production of hydrogen from renewable energy sources through electrolysis and subsequently injecting it into the natural gas network, gives flexibility in power grid regulation and the energy storage. In this context, knowledge about the hydrogen percentage content, which can safely effect on materials in a long time steel pipeline service during transport of the hydrogen-natural gas mixture, is essential for operators of a transmission network. This paper first reviews the allowable content of hydrogen that can be blended with natural gas in existing pipeline systems, and then investigates the impact on linepack energy with both startup and shutdown of the compressors scenarios. In the latter case, an unsteady gas flow model is used. To avoid spurious oscillations in the solution domain, a flux limiter is applied for the numerical approximation. The GERG-2008 equation of state is used to calculate the physical properties. For the case study, a tree-topological high pressure gas network, which have been inservice for many years, is selected. The outcomes are valuable for pipeline operators to assess the security of supply.
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Authors and Affiliations

Maciej Witek
1
Ferdinand Uilhoorn
1

  1. Warsaw University of Technology, Department of Heating and Gas Systems, Nowowiejska 20, 00-653 Warsaw, Poland
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Abstract

The aim of this paper is twofold: to estimate the unsteady pressure-flow variations in gas transmission pipelines using the ensemblebased data assimilation approach and to analyse the strength of steel tubes reinforced with composite sleeves containing localized part-wall thickness loss caused by corrosion while taking into consideration a safe operating pressure of the pipeline. For a steel thin-walled cylinder containing a partwall metal loss, a flexible wrap of fibreglass as well as carbon glass with epoxy resin are determined. The strength of the repaired pipeline with two kinds of materials for sleeves is investigated taking into consideration the internal pressure at the defect location. For the case study, a section of the Yamal transit pipeline on the Polish territory is selected. The results enable pipeline operators to evaluate the strength of corroded steel pipelines and develop optimal repair activities, which are of vital importance for the maintenance and operation of underground steel networks.

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Authors and Affiliations

Maciej Witek
Ferdinand Uilhoorn
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Abstract

On the basis of measurements of the depth of occurrence of 11000 krill aggregations and the biological analyses of these animals and measurements of some environmental factors the diurnal vertical distribution of aggregations is presented against the background of various environmental conditions. Vertical distribution of aggregations is closely related to the feeding rhythm of krill. Active vertical migrations have been recorded at civil twilight. The increasing and decreasing rate of aggregations in those periods is described.

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Authors and Affiliations

Janusz Kalinowski
Zbigniew Witek
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Abstract

In the plankton samples, collected with a Nansen net in three water layers downwards to a depth of 500 m, larvae and eggs of Euphausia superba were found as well as the larvae of E. crystallorophias and E. frigida. Eggs of the species E. superba predominated and among the larvae most numerous were calyptopis I and metanauplius stages. Eggs and larvae of E. superba occurred in small quantities, mainly in Bransfield Strait. Larvae of E. crystallorophias were found in the southeastern part of Bransfield Strait. Metanauplius, calyptopis I and II stages were predominant. Larvae of E. frigida, mostly calyptopis I stage, were very scarce and occurred only at the stations located in Drake Passage.

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Authors and Affiliations

Zbigniew Witek
Wojciech Kittel
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Abstract

This paper focuses on three issues. First, it is about the context and environment of pre-Nicene theology. It is emphasized that pre-Nicene theology did not neglect ca-techetical and liturgical reflection (ad intra) while at the same time successfully ente-red into a critical and creative dialogue with both the Semitic and Greco-Roman world where first Christians lived (ad extra). For contemporary theology its means that it cannot reject historical reasoning, placed in space and time. The second part stresses that, in spite of different situations and all historical and cultural contexts, theology before Nicea was above all an understanding of Sacred Scripture to which the key is the Risen Christ as the source and definitive fulfilment of the inspired writings. Finally, the third part of the paper focuses on the existential and spiritual experience from which pre-Nicene theology originated. For this theology the Gospel of Christ is not just the rule of faith but also the rule of life. This leads to a conclusion that a contem-porary theologian is a to take up an existential-personalistic reflection on Revelation using the historical-hermeneutic method .

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Authors and Affiliations

Ks. Krzysztof Witko
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Abstract

Andrzej Wajda’s films are interesting and serious historical narratives, which enter in dialog both with academic historiography and with other forms of familiarization with the past. Some of Wajda’s historical films are part of the paradigm of the affirmative vision of history. It is a vision that focuses on creating the positive picture of the bygone world, on showing those elements of the past that a given community recognizes as glorious and heroic, worth imitating, commemorating, and honoring, which can be the object of pride or even worship. The affirma-tive vision of history belittles, leaves in the background or omits all those themes from the past that fall outside positive evaluation for various reasons and could distort a consistent favorable picture of the past of a community. In the present article I would like to examine from the comparative perspective of two films, “A Generation [ Pokolenie]” (1954) and “Katyń” (2007). The comparison between Andrzej Wajda’s two films made in the space of fifty years shows that despite the fact that the two pictures were produced in entirely different historico‑cultural contexts, using different film styles, the two screen stories present the affirmation of diametri-cally disparate versions of history, it is the dramatic strategies for and techniques of affirmation of history that remain the same in either case.
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Authors and Affiliations

Piotr Witek
1
ORCID: ORCID

  1. Maria Curie‑Skłodowska University, Lublin
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Abstract

Distribution and population age structure of krill Euphausia superba larvae is presented for four consequent years on the basis of the summer materials from 1976 to 1979. An approximate rate of growth of krill larvae was calculated on the basis of the above observations and the literature data on the occurrence of particular larval stages. This allowed to determine the main period of krill breeding in particular years. Intense breeding of krill took place from January to middle of March in summers 1976/1977 and 1977/1978, but much earlier — mid November to mid January in 1975/1976. In summer of 1978/1979 the breeding of krill was poor till March.

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Authors and Affiliations

Zbigniew Witek
Andrzej Koronkiewicz
Grzegorz Jan Soszka
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Abstract

In the plankton samples collected with a Bongo net besides Euphausia superba the following species of the Euphausiacea were found:. £. frigida, crystallorophias, E. triacantha and T. macrura. The most aboundant and most frequently caught species was T. macrura equally distributed throughout the research area. The species E. frigida also occurred regularly though in much smaller numbers. E. triacantha occurred sporadically, mainly in the western part of the research region, and E. crystallorophias only at two stations in the Bransfield Strait. Some aspects of the biology and ecology of the mentioned above species are presented in this study.

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Authors and Affiliations

Wojciech Kittel
Zbigniew Witek
Henryk Czykieta
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Abstract

The knowledge about membrane contactors is growing rapidly but is still insufficient for a reliable designing. This paper presents a new type of membrane contactors that are integrated with one of the following ways of separation by using absorbents, micelles, flocculants, functionalized polymers, molecular imprints, or other methods that are based on aggregation. The article discusses methods for designing multi-stage cascade, usually counter-current. At every stage of this cascade, relevant aggregates are retained by the membrane, while the permeate passes freely through membrane. The process takes place in the membrane boundary layer with a local cross-flow of the permeate and the retentate. So the whole system can be called a cross-counter-current. The process kinetics, k, must be coordinated with the permeate flux, J, and the rate of surface renewal of the sorbent on the membrane surface, s. This can be done by using ordinary back-flushing or relevant hydrodynamic method of sweeping, such as: turbulences, shear stresses or lifting forces. A surface renewal model has been applied to adjust the optimal process conditions to sorbent kinetics. The experimental results confirmed the correctness of the model and its suitability for design of the new type of contactors.

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Authors and Affiliations

Andrzej B. Kołtuniewicz
Szymon Modelski
Anna Witek
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Abstract

The excellent property combination of thin wall ductile iron castings (TWDI), including thin wall alloyed cast iron (e.g. austenitic TWDI) has opened new horizons for cast iron to replace steel castings and forgings in many engineering applications with considerable cost benefits. TWDI is considered as a potential material for the preparation of light castings with good mechanical and utility properties, the cost of which is relatively low. In this study, unalloyed and high Ni-alloyed (25% Ni) spheroidal graphite cast iron, with an austenitic metallic matrix were investigated. The research was conducted for thin-walled iron castings with 2, 3 and 5mm wall thickness, using different mould temperature (20°C, and 160°C) to achieve various cooling rates. The metallographic examinations i.e. characteristic of graphite nodules, metallic matrix, and primary grains of austenite dendrites (in high-nickel NTWDI) and mechanical properties were investigated. The study shows that homogeneity of the casting structure of thin-walled castings varies when changing the wall thickness and mould temperature. Finally, mechanical properties of thin-walled ductile iron castings with ferritic-pearlitic and austenitic metallic matrix have been shown.

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Authors and Affiliations

M. Górny
M. Kawalec
G. Witek
A. Rejek
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Abstract

The article analyzes museum representations of communism in Poland from the perspective of exhibition strategies influencing the public understanding of the past. Over the past forty years, Western museums have increasingly moved away from the affirmative model of presenting the past, dominating since the nineteenth century, towards critical paradigms and even those pro-moting social activism. The analysis of Polish exhibitions devoted to recent history carried out from this perspective allows us to reveal the functions fulfilled by museum institutions in the Polish social and political reality.
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Authors and Affiliations

Anna Ziębińska-Witek
1
ORCID: ORCID

  1. Maria Curie‑Sklodowska University, Lublin
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Abstract

In the investigated area krill occured in low abundance. It was recorded mainly above the shelf and above the continental slope close to the Palmer Archipelago and near the northern shores of Elephant Island. In the central part of the Bransfield Strait E. superba was caught in especially small quantities. In general krill of small size occurred, the size decreasing from the west to the east. Mature krill was dominan in the western part of the investigated area, whereas juveniles in the eastern part. Gravid females were caught very rarely.

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Authors and Affiliations

Henryk Czykieta
Wojciech Kittel
Zbigniew Witek
Norbert Wolnomiejski
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Abstract

Macrozooplankton was collected at 63 stations by means of a Bongo sampler in the layer from the surface to a depth of 200 m. Wet formalin volume of siphonophors, polychaetes, pteropods, copepods, amphipods, euphausiids, chaetognaths, salps, and the remaining animals was determined; the distribution of major species was presented. Low diversity in macrozooplankton composition was observed in the study area. As far as biomass was concerned, salps predominated in the whole area; they occurred in exceptionally large quantities Large amounts of krill were also observed in some areas. Besides salps and krill, other euphausiids had the greatest share in the zooplankton; they were more abundant than copepods. Macrozooplankton biomass without salps and krill was low when compared with the values known from literature.

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Authors and Affiliations

Zbigniew Witek
Wojciech Kittel
Henryk Czykieta
Maria I. Żmijewska
Ewa Presler
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Abstract

The study has identified selected mechanical properties of fresh and stored fruit of large cranberry. The analyses focused on the changes in the values of peel and flesh puncture strength in the selected cranberry varieties depending on water content and storage duration. Measurements were also performed to examine deformations and energy needed to cut through the fruit peel and flesh. The value of breaking stress was calculated. The findings show a decrease in the relevant parameters during storage of fruit obtained from the examined varieties of large cranberry. Mean water contents in the fruit of the relevant varieties were in the range of 86.4-89.1%. There was a notable decrease in the mean value of peel and flesh puncture strength in the fruit of the relevant varieties of large cranberry. The mean value of peel and flesh puncture strength in the fresh fruit of cranberry was 6.1 N, and after 40 days in storage the value decreased by 2.3 N.
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Authors and Affiliations

Józef Gorzelany
Mirela Kotlicka
Natalia Matłok
Dagmara Migut
Grzegorz Witek

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