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Piotr Konieczka prof. dr hab. inż.
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Thermodynamics of solid phases containing rare earth oxides
PublicationRare earth elements (RE) are incorporated into a large variety of complex oxide phases to provide tailored mechanical, electrical, optical, and magnetic properties. Thermodynamics control phase stability, materials compatibility in use, corrosion, and transformation. This review presents, in one compilation, the thermodynamic properties of a large number of such materials and discusses systematic trends in energetics and the factors...
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Modelling of Different Aeration Modes Influencing Processes in SBR Bioreactor
PublicationCurrently, computer modelling together with the simulation tools tailored for that purpose constitute a very important element in planning technological changes within wastewater treatment plant. From the point of view of the WWTP operator every modification should be introduced in order to improve the quality of treated sewage with the lowest financial outlays. These requirements can be met by using computer programmes to effectuate...
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Recent advances in high-frequency modeling by means of domain confinement and nested kriging
PublicationDevelopment of modern high-frequency components and circuits is heavily based on full-wave electromagnetic (EM) simulation tools. Some phenomena, although important from the point of view of the system performance, e.g., EM cross-coupling effects, feed radiation in antenna arrays, substrate anisotropy, cannot be adequately accounted for using simpler means such as equivalent network representations. Consequently, the involvement...
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Video traffic data - Interchange Sosnica (A1 - 902), Poland
Open Research DataThe data includes video traffic data registered with 8 video cameras at weaving area (weaving section type A) of the Sosnica interchange within A1 motorway in Poland (interchange of motorway A1 and regional road 902, located in the Silesian Agglomeration).The data covers the two days: 12.09.2017 (motorway A1) and 11.09.2017 (road 902).
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Spectral splittings in the Conley index theory
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Otopy classes of equivariant maps
PublicationW artykule definiuje się stopień topologiczny niezmienniczych odwzorowań lokalnych w przypadku gradientowym i niegradientowym. Wyniki dotyczą relacji pomiędzy tymi dwoma niezmiennikami topologicznymi.
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On relations between gradient and classical equivariant homotopy groups of spheres
PublicationWe investigate relations between stable equivariant homotopy groups of spheres in classical and gradient categories. To this end, the auxiliary category of orthogonal equivariant maps, a natural enlargement of the category of gradient maps, is used. Our result allows for describing stable equivariant homotopy groups of spheres in the category of orthogonal maps in terms of classical stable equivariant groups of spheres with shifted...
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Combinatorial scheme of finding minimal number of periodic points for smooth self-maps of simply connected manifolds
PublicationLet M be a closed smooth connected and simply connected manifold of dimension m at least 3, and let r be a fixed natural number. The topological invariant D^m_r [f], defined by the authors in [Forum Math. 21 (2009), 491-509], is equal to the minimal number of r-periodic points in the smooth homotopy class of f, a given self-map of M. In this paper, we present a general combinatorial scheme of computing D^m_r [f] for arbitrary dimension...
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Connected components of the space of proper gradient vector fields
PublicationWe show that there exist two proper gradient vector fields on Rn which are homotopic in the category of proper maps but not homotopic in the category of proper gradient maps.
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The Hopf type theorem for equivariant gradient local maps
PublicationWe construct a degree-type otopy invariant for equivariant gradient local maps in the case of a real finite-dimensional orthogonal representation of a compact Lie group. We prove that the invariant establishes a bijection between the set of equivariant gradient otopy classes and the direct sum of countably many copies of Z.
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Morse cohomology in a Hilbert space via the Conley index
PublicationThe main theorem of this paper states that Morse cohomology groups in a Hilbert space are isomorphic to the cohomological Conley index. It is also shown that calculating the cohomological Conley index does not require finite-dimensional approximations of the vector field. Further directions are discussed.
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Periodic expansion in determining minimal sets of Lefschetz periods for Morse–Smale diffeomorphisms
PublicationWe apply the representation of Lefschetz numbers of iterates in the form of periodic expansion to determine the minimal sets of Lefschetz periods of Morse–Smale diffeomorphisms. Applying this approach we present an algorithmic method of finding the family of minimal sets of Lefschetz periods for Ng, a non-orientable compact surfaces without boundary of genus g. We also partially confirm the conjecture of Llibre and Sirvent (J Diff...
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The Conley index, cup-length and bifurcation
PublicationZastosowano strukturę modułu w indeksie kohomologicznym Conleya do dowodu twierdzenia o minimalnej ilości rozwiązań okresowych dla układów Hamiltonowskich. Wykazano też ogólne twierdzenia dotyczące nietrywialności struktury mudułu.
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Connecting orbits for a periodically forced singular planar Newtonian system
PublicationW niniejszym artykule badamy problem istnienia i krotności rozwiązań homoklinicznych i heteroklinicznych dla nieautonomicznych układów Newtonowskich na płaszczyźnie z potencjałem okresowym ze względu na zmienną czasową, mającym maksimum globalne właściwe przyjmowane w dwóch punktach płaszczyzny i punkt osobliwy (studnię nieskończonej głębokości), w otoczeniu którego potencjał spełnia warunek Gordona (gradient potencjału ze względu...
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Depth Images Filtering In Distributed Streaming
PublicationIn this paper, we propose a distributed system for point cloud processing and transferring them via computer network regarding to effectiveness-related requirements. We discuss the comparison of point cloud filters focusing on their usage for streaming optimization. For the filtering step of the stream pipeline processing we evaluate four filters: Voxel Grid, Radial Outliner Remover, Statistical Outlier Removal and Pass Through....
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Share of gross value added by factors of production prices generated by the enterprise sector in Poland and in the EU countries in the GDP of individual countries
Open Research DataCompanies operating in the EU countries are characterized by a greater contribution to the creation of GDP than Polish enterprises. Discrepancies in shaping the described value also result from a different industry structure of companies. In other EU countries, more companies are involved in services, and in Poland, enterprises conducting commercial...
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A Series-Inclined-Slot-Fed Circularly Polarized Antenna for 5G 28-GHz Applications
PublicationThis letter presents the design of a single-point-fed, geometrically simple circularly polarized (CP) antenna for 28 GHz Ka-band applications. The proposed antenna is based on a straight microstrip line printed on one side and coupled with the nearly square patches through a 45-degree inclined V-shape slot aperture on the other side. In order to generate circular polarization, the fundamental radiating mode is degenerated at a...
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Smart Asset Management for District Heating Systems in the Baltic Sea Region.
PublicationThe purpose of this review is to provide insight and a comparison of the current status of district heating (DH) systems for selected Baltic Sea countries (Denmark, Germany, Finland, Latvia, Lithuania, Poland, and Sweden), especially from viewpoints of application and solutions of novel smart asset management (SAM) approaches. Furthermore, this paper considers European projects ongoing from 2016, involving participants from the...
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Experimental comparison of hydrodynamic thrust bearings with different pad surface materials
PublicationBabbitt is the material most frequently used as the pad surface material for hydrodynamic bearings operating at usual operating conditions. It shows many advantages important for safe bearing operation, as for example: low friction coefficient, corrosion resistance, fair mechanical properties and outstanding conformability. On the other hand, it is not free from disadvantages, such as limited fatigue strength or limited resistance...
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Karolina Krośnicka dr hab. inż. arch.
PeopleKarolina A. Krośnicka, Ph.D., D.Sc., Eng. Arch., is associated professor at Department of Urban Design and Regional Planning, Faculty of Architecture, Gdańsk University of Technology (Poland). For many years (1998 – 2016) she was employed at the Department of Transport and Logistics at the Faculty of Navigation at Gdynia Maritime University (Gdynia, Poland), where she was mostly involved in issues connected with seaports and port...
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The impact of addition of olive oil on thermal degradation of refined rapeseed oil
PublicationFats are an important component of the everyday diet and have a significant impact on the proper functioning of human organism. However, during the process of frying chemical transformations take place in the oil; hence fats characterised by high oxidative stability should be given preference. The aim of this work was to determine the quality of rapeseed oil, blended oil, and refined olive oil, all sourced from the domestic market....
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Duct adenocarcinoma, NOS - Female, 66 - Tissue image [12010630011279481]
Open Research DataThis is the histopathological image of BREAST tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Duct adenocarcinoma, NOS - Female, 66 - Tissue image [12010630011271431]
Open Research DataThis is the histopathological image of BREAST tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Study on Microstructure and Mechanical Properties of Laser Welded Dissimilar Joint of P91 Steel and INCOLOY 800HT Nickel Alloy
PublicationThis investigation attempts to explore the weld characteristics of a laser welded dissimilar joint of ferritic/martensitic 9Cr-1Mo-V-Nb (P91) steel and Incoloy 800HT austenitic nickel alloy. This dissimilar joint is essential in power generating nuclear and thermal plants operating at 600–650 °C. In such critical operating conditions, it is essential for a dissimilar joint to preserve its characteristics and be free from any kind...
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High-Efficacy Global Optimization of Antenna Structures by Means of Simplex-Based Predictors
PublicationDesign of modern antenna systems has become highly dependent on computational tools, especially full-wave electromagnetic (EM) simulation models. EM analysis is capable of yielding accurate representation of antenna characteristics at the expense of considerable evaluation time. Consequently, execution of simulation-driven design procedures (optimization, statistical analysis, multi-criterial design) is severely hindered by the...
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On bounded load routings for modeling k-regular connection topologies
PublicationW pracy analizowane są problemy modelowania k-regularnych topologii sieci komputerowych z punktu widzenia routingu typu point-to-point. Zaprezentowane są algorytmy oraz przeprowadzona jest analiza złożoności obliczeniowej.
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Android OS: A Review
PublicationDue to the technological development, mobile terminals have evolved into functionally sophisticated devices such as smartphones and tablets. The Android platform has become one of the most popular operating system with millions of new users each year. Despite many studies, none have provided a comprehensive description of this operating system. In this paper we present a review of the Android OS. We describe the platforms history...
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Sample preparation techniques for determination of pesticide residues in food samples
PublicationPesticides are very important in increasing the efficiency and quality of agricultural production. They are applied in many spheres of life, not only in agriculture, and their applications are expanding. Despite their numerous merits, pesticides are some of the most toxic substances contaminating our environment and have a negative impact on the human health. Properties of pesticides such as stability, ability to bioaccumulation...
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DETERMINATION OF THE AERODYNAMIC DRAG OF PNEUMATIC LIFE RAFTS AS A FACTOR FOR INCREASING THE RELIABILITY OF RESCUE OPERATIONS
PublicationEnsuring the safety of ship crews at sea is of the utmost importance. Life rafts are one of the basic components of any seagoing vessel and ensuring their stability is an important component of maritime research. This study concerns the determination of the aerodynamic drag coefficients of pneumatic life rafts in a full range of wind speed and directions. The drag coefficients are based on full-scale experimental studies and numerical...
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Computational Bar Size Optimization of Single Layer Dome Structures Considering Axial Stress and Shape Disturbance
PublicationA computational method is proposed in this paper to minimize the material usage in the construction of modern spatial frame structures by prestressing a minimal number of members. The computational optimization is conducted in two steps. Firstly, a numerical model of a single-layer dome structure is used to minimize the cross-sectional area through several iterations. Different assumed ratios (r) ranging from 0.95 to 0.75 are multiplied...
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Chromium Cluster Luminescence: Advancing Near‐Infrared Light‐Emitting Diode Design for Next‐Generation Broadband Compact Light Sources
Open Research DataIn modern technology devices, an energy-saving miniature near-infrared (NIR) light source plays a critical role in non-destructive, non-invasive sensing applications and further advancement of technology. This dataset reports the broadband NIR luminescence of Cr3+ clusters for designing phosphor-converted NIR light-emitting diodes as an alternative...
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Measurements of power supply system properties of "Magnetic SpeedLine" ultra-fast robot prototype for IML labeling
Open Research DataTests of the power supply system of "SpeedLine magnetic" ultra-fast industrial robot for IML labeling were carried out to analyze the effect of the active power filter (APF) parameters on the power quality. at the target duty cycle. Tests were performed with the target duty cycle. Linear synchronous motors with permanent magnets were used to drive...
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WIG rate of return histogram and normal distribution curve
Open Research DataThe conducted market analysis covered the period of stock exchange quotations from the beginning of 2010 to the end of 2019 (04/01/2010 - 30/12/2019). Daily data was used, in the form of closing prices of indices operating on the Warsaw Stock Exchange. In order to obtain a complete and generalized picture of the market, the quotations of 4 indices were...
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Flame retardant epoxy/halloysite nanotubes nanocomposite coatings: Exploring low-concentration threshold for flammability compared to expandable graphite as superior fire retardant
PublicationEpoxy nanocomposites containing halloysite nanotubes (HNTs) were developed and their low-concentration thresholds for thermal stability and flame retardancy were compared with that of epoxy system containing expandable graphite (EG), as a reference with superior flame retardancy. The effects of HNTs and EG on the peak of Heat Release Rate (pHRR), Total Heat Release (THR), and Time-To-Ignition (TTI) of the prepared samples were...
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Molecular dynamics simulations reveal the balance of forces governing the formation of a guanine tetrad—a common structural unit of G-quadruplex DNA
PublicationG-quadruplexes (G4) are nucleic acid conformations of guanine-rich sequences, in which guanines are arranged in the square-planar G-tetrads, stacked on one another. G4 motifs form in vivo and are implicated in regulation of such processes as gene expression and chromosome maintenance. The structure and stability of various G4 topologies were determined experimentally; however, the driving forces for their formation are not fully...
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Novel Versatile Topologies and Design Optimization of Wide-Bandstop Frequency Selective Surfaces for X-Band, Ku-Band and Millimeter-Wave Applications
PublicationNovel designs of frequency selective surface (FSS) are presented for wideband applications in X, Ku and mmWave (millimeter Wave) bands. Two identical metallic layers of FSS are imprinted on both sides of the RO4003 substrate. The geometry parameters are optimized to maximize the bandstop at the specified in-band maximum transmission level of –10 dB; satisfaction of the latter condition is enforced through appropriate formulation...
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Considerations about the applicability of the Reynolds equation for analyzing high-speed near field levitation phenomena
Publicationequation for analyzing near field levitation (NFL) phenomena. Two separate approaches were developed, experimentally verified, and applied to meet the research objective. One was based on the Reynolds equation and the other was based on general conservation equations for fluid flow solved using computational fluid dynamic (CFD). Comparing the calculation results revealed that, for certain operating conditions, differences in the...
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Uproszczone metody obliczania wyboczenia silosów z blachy falistej wzmocnionych słupami na podstawie analizy MES i wyników doświadczalnych
PublicationRozprawa doktorska dotyczy zagadnienia stateczności i nośności granicznej stalowych silosów z płaszczem z blachy falistej wzmocnionych pionowymi słupami. Przeprowadzono zaawansowane analizy numeryczne MES oraz badania doświadczalne dotyczące wyboczenia/stateczności analizowanych silosów. Analizy numeryczne zostały przeprowadzone w zakresie liniowej oraz nieliniowej analizy stateczności, z uwzględnieniem wstępnych imperfekcji geometrycznych...
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Anomalous anisotropy of deuterium-grown boron-doped diamond and the role of boron-tetramers in the Mott-Insulator transition
Open Research DataWe show anisotropy in the superconductivity for boron-doped diamond thin films prepared with Microwave Plasma Assisted Chemical Vapor Deposition using deuterium-rich plasma. This anomalous phase transition is linked with the emergence of boson quantum entanglement states behaving as a bosonic insulating state. Here, we show that the superconducting...
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Simulation of ship spiral test for ballast and full load conditions
Open Research DataThe data show the results of the spiral test for the simplified ship model, taking into account two states of loading: ballast and full load. The data set contains the results of time simulation for sea state 10 on the Beaufort scale: changes in rudder angle delta_tab[deg]; angular velocity r_tab[deg/s]; surge velocity u_tab (m/s); sway velocity v_tab...
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Modeling of entrained flow steam gasification of sewage sludge
PublicationProper management of sewage sludge becomes increasingly problematic due to legal requirements aiming at diminishing environmental impact, as well as rationalizing the utilization from the point of view of logistics. Steam gasification of sewage sludge can result in very good quality of the producer gas. So far, the works have been focused on the gasification in fixed bed gasifiers. However, this does not allow to take full advantage...
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Extremal thermal loading of a bifurcation pipe
PublicationThe subject of considerations is a spherical bifurcation pipe of a live steam made of steel P91, which is an element of a block of coal-fired power plant working with a 18K370 turbine. As experience shows, it is a very sensitive element of the boiler pipelines. An extreme work scenario for such a block has been adopted, in which the turbine is shutting down to a warm state three times in 24 hours. This is an action dictated by...
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Accelerated design optimization of miniaturized microwave passives by design reusing and Kriging interpolation surrogates
PublicationElectromagnetic (EM) analysis has become ubiquitous in the design of microwave components and systems. One of the reasons is the increasing topological complexity of the circuits. Their reliable evaluation—at least at the design closure stage—can no longer be carried out using analytical or equivalent network representations. This is especially pertinent to miniaturized structures, where considerable EM cross-coupling effects occurring...
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Theoretical analysis and experimental tests of tilting pad journal bearings with shoes made of polymer material and low-boiling liquid lubrication
PublicationSelecting the appropriate bearing system for the rotor requires a good knowledge of the available solutions and the operating conditions of the machine. For newly designed machinery operating in adverse conditions, selecting bearings that ensure correct and long-lasting operation can be extremely challenging. Difficulties in- crease when the machine’s operating parameters are beyond the technical capabilities of available technical solutions....
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A robust sliding mode observer for non-linear uncertain biochemical systems
PublicationA problem of state estimation for a certain class of non-linear uncertain systems has been addressed in this paper. In particular, a sliding mode observer has been derived to produce robust and stable estimates of the state variables. The stability and robustness of the proposed sliding mode observer have been investigated under parametric and unstructured uncertainty in the system dynamics. In order to ensure an unambiguous non-linear...
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Gold nanocubic structures agglomeration when put on conductive surfaces
Open Research DataThis dataset contains SEM images of gold nanocubes (AuNC), which were deposited at the conductive Si wafer surface and dried. The deposition method, the solvent used and AuNC concentration have a significant influence on the homogeneous distribution and their agglomeration at the surface, further influencing the electrochemical characteristics of the...
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X-ray diffraction spectra of nitrogen-doped carbon in hybrid materials containing praseodymium oxide
Open Research DataX-ray powder diffraction patterns of samples were carried out by Philips X’Pert diffractometer, which was radiated by graphite monochromatized Cu Kα (l equal 1.540598). The operating voltage was maintained at 40 kV, the current was maintained at 30 mA and analyzed in the range from 20° to 90°. The data presented confirmed the presence of the PrBSCF...
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Place identity in socialist-modernist building
Open Research DataThe data include 96 individual response of falowiec's residents on the following scales (1) social identification, (2) falowiec’s place identity (3) interest in history of place. Each line represents responses obtained from one participant and his or her demographic characteristics. like gender, age, and education level.
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Place attachment, place identity, and satisfaction with urban aesthetic.
Open Research DataThe data include individual responses on the following scales (1) place attachment, (2) place identity, and (3) satisfaction with an urban aesthetic. Each line represents responses obtained from one participant and his or her demographic characteristics. like gender, age, and education level.