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Number of results: 162
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Abstract

On the basis of 35 one-hour series of the measurement of the wind velocity, read out every two minutes, the wind structure at the Arctowski Station, situated on Admiralty Bay, King George Island, was analysed. Very strong turbulence was found with air flow directions from over the area of the Island (S, SW. W and NW) and laminarity with directions from SE, E, NE and partly N, i.e. when the air flows from Admiralty Bay or from over the open waters of Bransfield Strait. The qustiness coefficient, the relationship between the maximum and mean velocities and the intensity of turbulence were determined for the two flow types. Two extremely different cases, in terms of flow character, were considered, by determining for them the distributions of instantaneous velocities and those of oscillations.
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Abstract

Helical coil heat exchangers are widely used in a variety of industry applications such as refrigeration systems, process plants and heat recovery. In this study, the effect of Reynolds number and the operating temperature on heat transfer coefficients and pressure drop for laminar flow conditions was investigated. Experiments were carried out in a shell and tube heat exchanger with a copper coiled pipe (4 mm ID, length of 1.7 m and coil pitch of 7.5 mm) in the temperature range from 243 to 273 K. Air – propan-2-ol vapor mixture and coolant (methylsilicone oil) flowed inside and around the coil, respectively. The fluid flow in the shell-side was kept constant, while in the coil it was varied from 6.6 to 26.6 m/s (the Reynolds number below the critical value of 7600). Results showed that the helical pipe provided higher heat transfer performance than a straight pipe with the same dimensions. The convective coefficients were determined using theWilson method. The values for the coiled pipe were in the range of 3–40 W/m2 ·K. They increased with increasing the gas flow rate and decreasing the coolant temperature.
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Abstract

Over the South American sector of the Antarctic Ocean intensive cyclonal activity occurred in turn with meridional circulation, which was a more common feature of winter 1986 than it usually is. At the Arctowski Station strong temperature oscillations were observed during the austral winter from May to October. In the end of July the lowest temperature of this winter, — 32.3°C, was recorded. In the first half of the winter an easterly air flow prevailed and in the second part — the westerly one. Winds were strong and gusty. The highest speed reached 74 ms-1 . Snowfalls were abundant; depth of snow exceeded 100 cm.
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Abstract

An algorithm of determination of mechanical stresses and deformations of the magnetic circuit shape, caused by forces of magnetic origin, is presented in this paper. The mechanical stresses cause changes of magnetizing characteristics of the magnetic circuit. The mutual coupling of magnetic and mechanical fields was taken into account in the algorithm worked out. A computational experiment showed that it was possible to include the interaction of both fields into one numerical model. The elaborated algorithm, taking into account the impact of mechanical stresses on magnetic parameters of construction materials, can be used in both the 2D and the 3D type field-model.
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Abstract

Exploitation of hard coal seams by roadway system is applied by two coal mines in southern Poland in Upper Silesian Basin. It is a secondary mining exploitation carries out in safety pillars of urban areas and shafts within mining areas of closed coal mines. Roadway system is the excavation process of gateways which are made in parallel order leaving coal pillars between them. An optimal width of coal pillar makes roadway stable and reduces subsidence of terrain surface. The article presents results of subsidence simulation caused by partial extraction using empirical and numerical methods on the example of one exploitation field of “Siltech” coal mine. The asymptotic state of subsidence was considered after mining ceased in the study area. In order to simulate of subsidence, numerical model of rock mass and model of Knothe-Budryk theory were calibrated. Simulation of vertical displacements in numerical method was carried out using RS3 program by Rocscience based on finite element method. The assumption was made that model of rock mass is transversely isotropic medium, in which panels were designed according to order of extraction of coal seams. The results of empirical and numerical methods were compared with measured values of subsidence at benchmarks along drawn lines (subsidence profiles).
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Abstract

This paper presents a complex study of anhydrite interbeds influence on the cavern stability in the Mechelinki salt deposit. The impact of interbeds on the cavern shape and the stress concentrations were also considered. The stability analysis was based on the 3D numerical modelling. Numerical simulations were performed with use of the Finite Difference Method (FDM) and the FLAC3D v. 6.00 software. The numerical model in a cuboidal shape and the following dimensions: length 1400, width 1400, height 1400 m, comprised the part of the Mechelinki salt deposit. Three (K-6, K-8, K-9) caverns were projected inside this model. The mesh of the numerical model contained about 15 million tetrahedral elements. The occurrence of anhydrite interbeds within the rock salt beds had contributed to the reduction in a diameter and irregular shape of the analysed caverns. The results of the 3D numerical modelling had indicated that the contact area between the rock salt beds and the anhydrite interbeds is likely to the occurrence of displacements. Irregularities in a shape of the analysed caverns are prone to the stress concentration. However, the stability of the analysed caverns are not expected to be affected in the assumed operation conditions and time period (9.5 years).
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Abstract

Paper discusses an issue of old-time gentry estates landscape formation based on po-lish agricultural textbooks. Theoretical proposals as well as real-life structures of gentry estates on polish lands in pre-parti-tion and post-partition times are analyzed. Article presents both rules of shaping mo-dest gardens of decorative and utilitarian functions alike in the vicinity of mansions, and other components of estate’s land-scape. Partial concurrence between theore-tical postulates and real land use is proven.
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Abstract

Article 51 of the UN Charter, in affi rming the inherent right of self-defence of each UN Member State “against which an armed attack has occurred”, clearly indicates that the concept of armed attack plays a key role in delineating the right of self-defence. The concept in question was not, however, defi ned in the UN Charter, and no universally acceptable defi nition has yet emerged either in practice or in doctrine. One of the fundamental questions to be addressed in this context is who must engage in armed activity for it to qualify as an armed attack. This question is of particular relevance today because of the threat of international terrorism and the expansion of the concept of armed attack through the inclusion of an act of terrorism. The article discusses in some detail the emerging legal framework for attribution of actions undertaken by non-state actors to states.
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Abstract

This article is referenced to the thirtieth anniversary of the ICJ’s Nicaragua judgement on the merits of 1986. It acknowledges the significance of this much-debated judgement for the modern international law on the use of force (jus ad bellum). However the text focuses on one aspect of the judgment only, i.e. the definition of the notion of “armed attack” as the most grave form of the use of force. The impact of the judgement in this respect is critically analysed. It is argued that the introduction to the UN Charter text of undefined notions of the use of force, aggression, and armed attack may be labelled as the “original sin” of contemporary jus ad bellum, as it results in conceptual obscurity. It is also claimed that the ICJ reaffirmed this original sin in its Nicaragua judgment because it explicitly argued for the notion of “armed attack” as the most grave form of the use of armed force and, in consequence, distinguished it from the other, lesser forms of the use of force, while failing to introduce any sort of clarity in the conceptual ambiguity of jus ad bellum. The article also offers some remarks de lege ferenda and suggests abandoning the gravity criterion, which would require abandoning the well-established judicial and doctrinal interpretation approaches to jus ad bellum.
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Abstract

Jean Pierre Norblin de la Gourdaine (1745–1830), a French artist working in Poland for the princely family of Czartoryski between 1774 and 1804, made a number of drawings picturing Polish dietines. We currently know his seventeen works devoted to this topic (some of them are his own replicas) as well as three copies of his drawings (one of them is a copy of an original which remains unknown). As many as six of the above works are kept in the collections of the PAN Kórnik Library. Dietines were regional assemblies of noblemen, which, consisting of elected members of the Sejm and some other officials, decided about taxation, approved decisions of the Parliament, and existed from the 15th until the 18th centuries. They were most often held in churches. As much as their source documentation is rich, their iconography is very scant. This mainly consists of Norblin’s drawings, which for this reason are often reproduced as illustrations of historical or popular science works. They have very rarely been subject to a scientific analysis. The author shows that Norblin’s Dietines, commonly considered to be drawn on the spot, are not documentaries depicting the reality, but works which manipulate its elements. On the one hand, Norblin was an excellent observer, who could minutely reproduce the realities of the material culture of the 18th century Poland (e.g. the cut of the uniforms of the Polish army, and the kontusz robes, żupan garments, hats, and sabres used by the Polish nobility, which changed between 1774 and 1794) even in quick sketches. At the same time, however, he did not shy away from inaccuracies, which sometimes possibly originated from his fantasy, and sometimes from his biased attitude to the scenes he was drawing. For example, some of the churches shown in his drawings are combinations of various Polish structures. Later, Norblin pictured Polish dietines in Gothic churches of French origins or even utterly fantastic shapes. Additionally, the author’s analysis proves that not a single composition refers to a concrete dietine (such identifications were offered earlier), or shows a concrete moment of the proceedings. Some elements were presented in an exaggerating caricature, or even in contrast to the reality – such as the participants sitting on altars and pulpits, or debating during a Holy Mass – which has never been the case. Norblin’s attitude to the presented topic changed over time. Initially, he strove to highlight the crisis suffered by the dietine as an institution in the 18th century. It was common for the poorer nobility who had voting rights to “sell” their votes and sabres to the rich candidates for the position of a member of the Sejm, and for sessions to change into disputes and brawls. Norblin’s first drawings show mainly the latter, whereas images depicting proper sessions and the most important personalities, i.e. magnates sitting in the centre of the temples and buying votes from the noblemen, are missing. But no wonder, since the artist’s patron, Prince Czartoryski, was such a magnate. The situation changed during the reforms adopted by the Sejm between 1788 and 1792, which aimed at the strengthening of the state and the improvement of the political system, including the dietines. Both Prince Czartoryski and Norblin himself were supporters of changes. From then on, the artist focused on a more positive, republican dimension of the dietine as an institution, although he did not entirely resign from grotesque motifs. However, Russia, Prussia, and Austria soon ended the existence of the Polish-Lithuanian Commonwealth, dividing its land between themselves (1795). Dietines became a part of past history. Eleven years later (1806), on a part of the area of the Commonwealth, Napoleon Bonaparte recreated the Polish state in a rump form and provided it with a constitution, which brought dietines back, although in a very limited dimension. Norblin’s last drawings date back to this period. They were made after the artist returned to France. These last compositions contain allusions concerning Napoleon’s impact on the Polish dietine as an institution. On the other hand, they were also reminiscent of an exotic past. It was for this reason that children and grandchildren of the artist’s former patrons purchased them. In this way, the majority of Norblin’s works found their way to the Kórnik collection created by Tytus Działyński and his son Jan. Worthy of note, during the Polish uprising against Prussia between 1848 and 1849, one of the artists covered by Tytus Działyński’s patronage created a lithograph showing the meeting of the socalled Polish League, which took place at the church in Kórnik in January 1849. His composition was clearly influenced by one of Norblin’s Dietines kept at the Kórnik Library.
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Abstract

The once famous defence of the manor house at Glanów near Imbramowice (a region of Małopolska) took place on Saturday 15 August, 1863. A detachment of insurgents under the command of the brothers Edward and Gustaw Habich, organised at the cost of Count Aleksander Krukowiecki, crossed the Austrian border to get to the Russian partition, and was attacked by three Moscow detachments by Glanów. The rear-guard comprising 10 insurgents led by the count, with Leon Rutkowski, to whom Glanów manor was leased, and his son Teofi l, defended themselves for several hours in the manor house set afi re by the Russians. Fatalities included a dozen or so Russians, Rutkowski, one insurgent and a woman. The encounter co-created the myth of the January Uprising for several dozens of years. It became the topic of a number of short literary works, but has not been the subject of a historical study so far. The author decided to fill in this gap and reconstructed the history of this encounter in detail, using previously unknown sources: a diary of the participant of the defence, Karol Firganek (…-1913; the work is highly critical towards official publications, which allows one to verify many details), as well as the archives and the tradition of the Novàk family – Leon Rutkowski’s descendants, who are still owners of the manor house at Glanów.
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Abstract

The 1863 uprising was directed against Russia, but the insurgents also came from the Polish territories remaining under the Austrian and Prussian partitions. The region of Western Wielkopolska, which at that time belonged to Prussia, was home to the illegal Działyński Committee headed by Count Jan Działyński, Lord of the Kórnik manor. The Committee, having its representatives all over the region, conducted a large-scale smuggling of weapons and volunteers through the Prussian- Russian border, organised whole detachments, and imported offi cers for them, mainly from France. It is no wonder then that numerous volunteers originated from Kórnik and its surroundings. About 50 of them were identifi ed by their full name, but we know that there were many more. 35 years ago comprehensive research on the issue was conducted by Ryszard Marciniak. The author of the article summarizes Marciniak’s research results, supplementing them at some points.
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Abstract

This article discusses the history and architecture of a typical urban smallholding located at ul. Poznańska 13 in Kórnik belonging to the Michałowski family and the daily life which occurred there. The property used to include a house, pig-sties, a stable, and a garden, all of which were located between the main town road and the edge of the lake, as well as a barn and a field situated outside the town. The owner of such an urban smallholding used to be referred to as a civis agricola, or Ackerburger in German. In the 18th century, the holding belonged to the Biniaks, a family o f craftsmen. Towards the end of the century, along with the hand of Katarzyna Biniak (ca. 1764-1844), it became the property of Andrzej Michałowski (1763-1830), a carpenter from the neighbouring town of Bnin. The current house and the surviving outbuildings were built in 1878 by Andrzej’s grandson, Michał Michałowski (1832-1902). It was one of the so-called Grunderzeit investment projects implemented at the beginning of the reign of Wilhelm I, Emperor of Prussia. From Michał, the property was taken over by Franciszek Michałowski (1858-1924) and his wife Anna nee Szelążkiewicz (1878-1962). The author extensively discusses the daily life in the smallholding in the first decades of the 20th century on the basis of written and oral sources collected also from their son Stanisław (1903-1984) and granddaughter Bogusława Michałowska-Kowalska (*1931), the author’s mother. Some furniture, windows, doors, paintings, daily objects, and numerous documents from the end of the 19th century and the beginning of the 20th century have managed to survive in the house until today. The later history of the property reflects the subsequent changes taking place in the life of the region and the country. After Franciszek’s death, Anna rebuilt the house, which ceased to be one household, becoming several tenant flats. During the Nazi occupation, Anna Michałowska was displaced, and deprived of her right to the property for the benefit of a German woman (Ursula Lehmann?). After 1945, the communist authorities assigned several families to live in the household, leaving only one room for Anna’s son, Stanisław. At that time, his political career (as an MP and as Deputy Mayor of Grudziądz in the 1930s; he was a member of the underground national authorities during the occupation) had been broken. During Stalinist times, he was imprisoned and was unable to practice his profession. It was then that he came back to Kórnik and the house became again the centre of a smallholding. Currently, it is the living place of the author - Stanisław’s grandson - and his closest family.
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Abstract

The aim of this article is to present a modern method of convective drying intensification caused by the external action of ultrasound. The purpose of this study is to discover the mechanism of ultrasonic interaction between the solid skeleton and the moisture in pores. This knowledge may help to explain the enhancement of drying mechanism affected by ultrasound, particularly with respect to biological products like fruits and vegetables. The experimental kinetics tests were conducted in a hybrid dryer equipped with a new ultrasonic generator. The drying kinetics curves determined on the basis of drying model developed by the author were validated with those by the ones obtained from experimental tests. The intensification of heat and mass transfer processes due to ultrasound induced heating effect and vibration effect are analysed. The obtained results allow to state that ultrasound makes drying processes more effective and enhance the drying efficiency of biological products without significant elevation of their temperature.
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