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Number of results: 37
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Abstract

The star-studded night sky has fascinated humankind since the dawn of time. Today, as we grow closer and closer to discovering a new Earthlike planet, our fascination with the skies has not weakened. On the contrary - our enchantment is approaching its zenit.
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Authors and Affiliations

Milena Ratajczak
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Abstract

Public space in geographical and social aspects. Space as a scientific and social term has many interpretations. Work organizes mutual relations between various kinds of spaces. The paper focuses on the contemporary determinants of shaping a public space in cities regarding the popularization of information and communication technologies. Attention was also paid to the metric feature of social spaces because it is usually neglected while constructing such spaces.
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Authors and Affiliations

Waldemar Ratajczak
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Abstract

The motion planning problem consists in finding a control function which drives the system to a desired point. The motion planning algorithm derived with an endogenous configuration space approach assumes that the motion takes place in an arbitrary chosen time horizon. This work introduces a modification to the motion planning algorithm which allows to reach the destination point in time, which is shorter than the assumed time horizon. The algorithm derivation relies on the endogenous configuration space approach and the continuation (homotopy) method. To achieve the earlier destination reaching a new formulation of the task map and the task Jacobian are introduced. The efficiency of the new algorithm is depicted with simulation results.
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Authors and Affiliations

Adam Ratajczak
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Abstract

Abstract The paper presents the approximation problem of the inverse kinematics algorithms for the redundant manipulators. We introduce the approximation of the dynamically consistent Jacobian by the extended Jacobian. In order to do that, we formulate the approximation problem and suitably defined approximation error. By the minimization of this error over a certain region we can design an extended Jacobian inverse which will be close to the dynamically consistent Jacobian inverse. To solve the approximation problem we use the Cholesky decomposition and the Ritz method. The computational example illustrates the theory.
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Authors and Affiliations

Joanna Ratajczak
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Abstract

Rozgwieżdżone nocne niebo fascynowało ludzkość od zarania dziejów. Dziś, u progu ery odkrycia drugiej Ziemi, fascynacja nieboskłonem nie słabnie. Wręcz. przeciwnie - oczarowanie sięga zenitu.
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Authors and Affiliations

Milena Ratajczak
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Abstract

The multi-dimensional cooperation between Count Władysław Zamoyski and St. Albert Chmielowski is an important fragment of Zakopane’s tradition. Their activity marked the period of the development of the town, which was on its way to becoming not only a famous spa, but also a centre of the Polish spiritual and political life. Owing to Zamoyski’s assistance, St. Albert erected a hermitage at the foot of the Tatra Mountains, which hosted some eminent artists from the Young Poland period. In line with the vision of Zakopane consistently implemented by Zamoyski, the sanctuary of prayer and contemplation was an indispensable element. There are testimonies according to which Count Zamoyski felt a monastic vocation and discussed the issue with the founder of the Albertine Brothers. St. Albert’s refusal to allow him to go resulted from his belief that Zamoyski’s economic activity was particularly beneficial from the social point of view, promoting not only civilizational but also spiritual progress. The cooperation of the two outstanding figures is without any doubt one of the most significant threads of Polish culture at the turn of the 20th century.

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Authors and Affiliations

Wiesław Ratajczak
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Abstract

The inscription “I am the Polish manor house, which fi ghts bravely and guards faithfully”, placed above the entry to the manor houses in the 19th century, suggested that in the face of the catastrophe of the state, the house has become a shelter of tradition. This belief was verifi ed by writers creating their works aft er the January Uprising, such as Michał Bałucki; but it was Eliza Orzeszkowa who presented the motif of the annihilation of a family seat most perfectly in her novella Śmierć domu [Death of the House]. In her poetic description, the author showed the transformation of the house into a grave. It is worth to recall Orzeszkowa’s last literary idea in this context. She shared it with Eugenia Żmijewska, who edited it as a novella Dwa spotkania [Two Meetings]. The romantic plot starts near a devastated, sealed Polish manor house. Theoretically speaking, the love between a Russian aristocrat and an insurgent’s widow could save the house, but it is also in this case that the destruction becomes unavoidable. The process of destruction was also described by Maria Rodziewiczówna in her novel Pożary i zgliszcza [Fires and Smoking Ruins]. Numerous images of the endangered or lost manor house express the [Poles’] awareness of the end of a certain form of Polish identity after 1864.

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Authors and Affiliations

Wiesław Ratajczak
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Abstract

We can hardly imagine the Earth without majestic trees and omnipresent shrubs. But not all of us realize that these plants owe their success to ubiquitous yet often unnoticeable fungi. What links these two types of organisms together is life-giving water. It is the reason why trees and fungi have been inseparable for hundreds of millions of years. How do droughts affect trees and their evolutionarily ancient symbiosis with fungi?

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Authors and Affiliations

Joanna Kijowska-Oberc
Ewelina Ratajczak
Marcin Pietras
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Abstract

The article characterizes geological formations occurring in the Polish lignite deposits having the characteristics of raw materials, i.e. accompanying minerals, giving their location, quality characteristics, estimated resources and potential applications. Attention has also been paid to the economic suitability, e.g. in infrastructure works and for the reclamation of many geological formations found in the overburden, classified as so-called earth or rock mass. There are also raw materials of sorption properties representing a huge potential source of minerals valuable for the economy and environmental protection. This refers to e.g.: beidellite clays from Bełchatów, Poznań clays from the region of Konin and Adamów, lacustrine chalk from Bełchatów, as well as Mesozoic limestone from the lignite bedding in Bełchatów. The reasons for the unsatisfactory use of accompanying minerals have been given. The authors described the methods used in the mining operation and processing of associated minerals, also applicable in Poland, as the legal basis for the extraction of these minerals and the economic and financial conditions. They stressed the need to protect mined not associated minerals used by the construction of anthropogenic deposits. This activity primarily requires regulating the legal status of these deposits and the development and application of an economic and financial system that stimulates the economy of these minerals. In summary, the necessary actions were taken to increase the use of the accompanying minerals and their contribution to the balance of mineral resources in the country.

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Authors and Affiliations

Tadeusz Ratajczak
Ryszard Uberman
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Abstract

The Legnica deposit is one of the most prospective in the context of future lignite mining. Its extraction will be inseparable from the removal of the rocks of the overburden, the volume of which is very large. Due to the raw material properties, some of the rocks can be classified as accompanying minerals. The raw material identification of overburden sediments in the Legnica lignite deposit is insufficient. So far, they haven’t been the subject of detailed and comprehensive research to prove their usefulness. The article was a summary of the knowledge on this subject. The following should be included in the accompanying minerals: Quaternary sands and gravels, tertiary sands and clays (Poznan clays). They are present in two colour variants in the Legnica deposit - and fiery. The mineral composition of greenish-blue clays allows them to be included in illite-kaolinite- smectite varieties, in turn fiery clays as kaolinite-illite-smectite varieties. The tertiary clays are a very useful raw material for the production of building materials. In addition, they are potential mineral sorbents due to the nature of the association of clay minerals (occurrence of montmorillonite). They also show suitability for building waterproofing barriers. Quaternary gravels and sands, developed in the overburden Legnica deposit are differentiated raw materials. Some of them are raw materials for the construction industry. The glacial tills can be used as a component of ceramic mixtures. Tertiary sands can be used as a proppant material. The information on the raw material properties of these sediments will be one of the essential criteria for their treatment as accompanying minerals. Minerals accompanying those developed in the Legnica deposit should be exploited and deposited selectively. The creation of anthropogenic deposits accumulating these minerals will provide the possibility of their use for decades after the termination of operation.

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Authors and Affiliations

Tadeusz Ratajczak
Elżbieta Hycnar
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Abstract

Abstract This paper presents the dynamically consistent Jacobian inverse for non-holonomic robotic system, and its application to solving the motion planning problem. The system’s kinematics are represented by a driftless control system, and defined in terms of its input-output map in accordance with the endogenous configuration space approach. The dynamically consistent Jacobian inverse (DCJI) has been introduced by means of a Riemannian metric in the endogenous configuration space, exploiting the reduced inertia matrix of the system’s dynamics. The consistency condition is formulated as the commutativity property of a diagram of maps. Singular configurations of DCJI are studied, and shown to coincide with the kinematic singularities. A parametric form of DCJI is derived, and used for solving example motion planning problems for the trident snake mobile robot. Some advantages in performance of DCJI in comparison to the Jacobian pseudoinverse are discovered.
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Authors and Affiliations

Joanna Ratajczak
Krzysztof Tchoń
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Abstract

The role of seeds is crucial in tree production and development, and the future of forests depends on them. But what impact is climate change having on the seed life cycle? Will the trees that grow out of them manage to survive and adapt to the new environment?

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Authors and Affiliations

Mikołaj Wawrzyniak
Ewelina Ratajczak
Ewa Kalemba
Paweł Chmielarz
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Abstract

What do biological powerhouses look like? How do they work? Why does generating a single “dose of energy” demand a highly complicated process? Why do seeds age? Answers to all these questions are to be found in one of the most complex cellular organelles: the mitochondrion.
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Authors and Affiliations

Joanna Kijowska-Oberc
1
Ewelina Ratajczak
1
Hanna Fuchs
1
Aleksandra Maria Staszak
2

  1. Institute of Dendrology, Polish Academy of Sciences in Kórnik, Poland
  2. Department of Biology and Plant Ecology, University of Bialystok, Poland
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Abstract

The exploitation and processing of lignite in the Bełchatów region is connected with the formation of various mineral waste materials: varied in origin, mineral and chemical composition and raw material properties of the accompanying minerals, ashes and slags from lignite combustion and reagipsum from wet flue gas desulphurisation installations. This paper presents the results of laboratory tests whose main purpose was to obtain data referring to the potential use of fly ashes generated in the Bełchatów Power Plant and selected accompanying minerals exploited in the Bełchatów Mine in the form of self-solidification mixtures. The beidellite clays were considered as the most predisposed for use from the accompanying minerals , due to pozzolanic and sorption properties and swelling capacity. Despite the expected beneficial effects of clay minerals from the smectite group on the self-settling process as well as the stability of such blends after solidification, the results of physical-mechanical tests (compressive strength and water repellence) were unsatisfactory. It was necessary to use Ca (OH)2, obtained from the lacustrine chalk as an activator of the self-settling process It was necessary to use lacustrine chalk as an activator of the self-solidification process. The presence of calcium will allow the formation of cement phases which will be able to strongly bond the skeletal grains. Also, the addition of reagipsum to the composition of the mixture would contribute to the improvement of the physico-mechanical parameters. The elevated SO4 2– ion in the mixture during the solidification allows for the crystallization of the sulphate phases in the pore space to form bridges between the ash and clay minerals. The use of mixtures in land reclamation unfavourably transformed by opencast mining in the Bełchatów region would result in measurable ecological and economic benefits and would largely solve the problem of waste disposal from the from the operation and processing of lignite energy.

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Authors and Affiliations

Elżbieta Hycnar
Marek Waldemar Jończyk
Tadeusz Ratajczak
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Abstract

The Tertiary lignite formations in the Bełchatów deposit, along with coal, are built of plastic, weakly compact and loose rocks. Their physical and mechanical parameters, don’t pose operational problems. However, varieties of a different lithological character and physical-mechanical properties rocks, causing difficulties when mining the overburden rocks, appear within them. These include: Mesozoic limestones, Tertiary sandstones and conglomerates, as well as Quaternary iron feldspar rocks. The article features a lithological characterization as well as values of basic physico-mechanical parameters. They form the basis of the geological engineering classification and decide about their difficult workability. The possibilities of their raw material utilization were also discussed.

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Authors and Affiliations

Elżbieta Hycnar
Marek Waldemar Jończyk
Tadeusz Ratajczak

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