Repozytorium publikacji - Politechnika Gdańska

Ustawienia strony

english
Repozytorium publikacji
Politechniki Gdańskiej

Pokaż publikacje z roku

Ostatnie pozycje

  • Interactions between hydration spheres of two different solutes in solution: The least squares fitting with constraints as a tool to determine water properties in ternary systems
    • Aneta Panuszko
    • Janusz Stangret
    • Bartosz Nowosielski
    • Piotr Bruździak
    2020 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS

    Biological systems are complex and the problem of their description lies in mutual interactions between their components. This paper is focused on model experiment-based studies which can reduce these difficulties. The ternary aqueous N-methylacetamide (NMA)–Na2HPO4 system has been studied by means of the FTIR spectroscopy. A novel difference spectra method aimed to extract the spectral contribution of water affected simultaneously by two solutes is proposed. The key improvement is the additional least squares curve fitting procedure with carefully selected constraints which allow obtaining information on the composition of water affected in complex solutions. The fitting parameters are optimized with the Monte Carlo method and the human influence on parameter selection is minimized. The simple method allows determining individual contributions originating in hydration of multiple solution components. FTIR spectra of water in the NMA–Na2HPO4 system gave an insight into the interactions and susceptibility for interactions between solvent and co-solutes or hydrated co-solutes.

  • Interface analysis of compatibilized polymer blends
    • Farnaz Mostafapoor
    • Azadeh Khosravi
    • Abdolhossein Fereidoon
    • Reza Khalili
    • Seyed Hassan Jafari
    • Vahabi Henri
    • Krzysztof Formela
    • Mohammad Saeb
    2020

    This chapter seeks to address the interface location in the compatibilized polymer blends and paves the way for quantitative analysis of interface in terms of interfacial tension and interfacial adhesion to provide support for understanding the relationship between morphology and ultimate properties in the compatibilized polymer blends through the lens of interface. Since understanding and analysis of interfacial phenomena in the compatibilized polymer blends are cumbersome, we started from binary blends and then opened some windows toward quantitative analysis of interface in the compatibilized ternary blends. Then, we give a broad view of interface situation having in mind both physical and chemical interactions to highlight the importance of interface analysis in reactive polymer blends. The contribution of interfacial phenomena to performance of compatibilized ternary blends, as the complex case, is finally discussed for the sake of optimization of properties by interfacial adhesion manipulation

  • Interfacial water controls the process of adsorption of hyperactive antifreeze proteins onto the ice surface
    • Joanna Grabowska
    • Anna Kuffel
    • Jan Zielkiewicz
    2020 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS

    A mechanism of interactions between the ice-binding surface of a hyperactive antifreeze protein molecule and the ice surface is proposed, involving the influence of water present between the two surfaces on the behavior of the approaching molecule. It is demonstrated that the interfacial water, even before its full solidification, can act as a factor that pushes away or pulls nearer the protein molecule to ensure its proper positioning. It is possible thanks to the structural properties of interfacial water. These properties include the ability to create high-volume aggregates of water molecules. They can appear near and be anchored to both the ice-binding plane of the anti- freeze molecule and the ice surface. When an AFP approaches the growing face of ice, these high-volume, ordered structures near the ice and near the AFP molecule merge together smoothly, but only if the proper distance be- tween the ice and the AFP is ensured. If this is not the case, the resulting merged structure is deformed from its preferred shape and as a result a force occurs that attempts to correct the positioning of the protein. Only then the crystallization of the merged aggregate can proceed unhampered which results in binding of the AFP molecule onto the ice.

  • Intergranular Corrosion Detection Using Electromagnetic Transducers for Ultrasonic Testing
    • Mateusz Cieślik
    • Kazimierz Darowicki
    2020 Pełny tekst ARCHIVES OF METALLURGY AND MATERIALS

    The aim of this paper is to create a research methodology that allows a quick analysis of the structural state of high alloy austenitic steels using non-destructive ultrasonic tests, in contrast to destructive standard methods. Electromagnetic acoustic transducers (EMAT) are used to generate and receive the ultrasonic wave and detect the microstructural changes caused by sample sensitization in elevated temperature, even after 0.5 h in high temperature exposition. Different acoustic response for reference sample and sensitized samples were recorded. In this work, changes in share wave amplitude were measured.

  • Interlaboratory Test to Characterize the Cyclic Behavior of Bituminous Interlayers: An Overview of Testing Equipment and Protocols
    • Francesco Canestrari
    • Thomas Attia
    • Hervé Di Benedetto
    • Andrea Graziani
    • Piotr Jaskuła
    • Youngsoo Richard Kim
    • Maciej Maliszewski
    • Jorge C. Pais
    • Christophe Petit
    • Christiane Raab
    • Davide Ragni
    • Dawid Ryś
    • Cesare Sangiorgi
    • Cédric Sauzéat
    • Adam Zofka
    2020 Pełny tekst

    The performance assessment of multi-layered pavements strongly depends on the mechanical behavior of the interface between bituminous layers. So far, comprehensive studies have been carried out mainly using quasi-static laboratory tests focusing on the interlayer shear strength at failure. However, it is generally recognized that cyclic shear testing will lead to the determination of parameters which are more closely linked to the performance of pavements under traffic loading than the quasi-static shear tests. This paper outlines the research work that has been carried out within the Task Group 3 “Pavement multilayer system” of the RILEM TC 272-PIM. The activities focused on cyclic shear testing of interfaces in bituminous pavements involve an interlaboratory test with nine participating laboratories. The interface behavior was investigated through both direct shear and torque tests on double-layered specimens extracted from lab compacted slabs prepared by one of the laboratories. The different testing equipment and protocols used by the participating laboratories are presented, highlighting the variety of geometries, loading modes, and testing parameters.

  • International architectural - urban - landscape design workshops to strengthen students’ education, capabilities and mobility
    • Aleksandra Sas-Bojarska
    • Magdalena Rembeza
    2020 Pełny tekst World Transactions on Engineering and Technology Education

    Five international architectural/urban/landscape workshops in Poland and Portugal between 2011 and 2015 are discussed in this article. The general aims of the workshops were to plan to connect divided city spaces, to harmonise them and make them attractive for different uses. The main task was to create in multicultural groups of students the vision of sustainable development in the context of architecture, urban and landscape design, with special attention to the environmental, social, spatial and transportation issues. The case studies could be good examples of academic co-operation that supports the mobility of students and academic teachers. Both groups benefited from the exchange of views, new ideas and trends, co-operation and the building of professional and personal relationships.

  • Interpolation methods in GPR tomographic imaging of linear and volume anomalies for cultural heritage diagnostics
    • Magdalena Rucka
    • Erwin Wojtczak
    • Monika Zielińska
    2020 Pełny tekst MEASUREMENT

    This paper presents results of a ground penetrating radar (GPR) survey conducted in St. Joseph’s Church in Gdańsk, Poland. The aim of the study was to produce tomographic imaging of a renovated floor as well as the objects buried under the floor to detect linear and volume inclusions. The assumed track spacing was meaningfully greater than the single signal spacing in each track, which induced the need for interpolation methods to estimate signal values in the areas beyond the trace lines. Various interpolation techniques were used to prepare the tomography maps. GPR time slices allowed the identification of reinforcing meshes, underfloor heating system elements and the foundations of entrances to crypts. The results obtained were compared to the exact images acquired in a dense regular grid to evaluate the efficiency of the applied interpolation methods and to verify the possibility of conducting GPR surveys with coarse track spacing.

  • Interpretation and modeling of emotions in the management of autonomous robots using a control paradigm based on a scheduling variable
    • Zdzisław Kowalczuk
    • Michał Czubenko
    • Tomasz Merta
    2020 Pełny tekst ENGINEERING APPLICATIONS OF ARTIFICIAL INTELLIGENCE

    The paper presents a technical introduction to psychological theories of emotions. It highlights a usable ideaimplemented in a number of recently developed computational systems of emotions, and the hypothesis thatemotion can play the role of a scheduling variable in controlling autonomous robots. In the main part ofthis study, we outline our own computational system of emotion – xEmotion – designed as a key structuralelement in the developed target device, being an Intelligent System of Decision-making (ISD) for autonomousand robotic units.The ISD system has a cognitive architecture based on the principles of human psychology. The mainpurpose of building such a system is to prepare a framework for autonomous units used in system engineering(Kowalczuk and Czubenko, 2011; Czubenko et al., 2015). In particular, ISD is based on the concepts ofcognitivepsychology(in information processing) andmotivation theory, which includes the system ofneeds(for decision-making). The xEmotion subsystem, however, focuses on modeling an alternative approach based on emotion.The xEmotion implementation covers aspects of somatic, appraisal and evolutionary theories of emotions usingfuzzy sets.In this article, we also illustrate the core emotional behavior of the ISD system using simulation. Thefirst application is a user interface for identifying emotions and predicting human behavior. The second is aneSailor simulation, which illustrates the possible behavior of the xEmotion subsystem. The last is an xDriversimulation experiment, which is to prove the validity of the concept of using emotion-based systems, accordingto the SVC principle. In summary, we also discuss other possible applications of the xEmotion system.

  • Interrelations between Travel Patterns and Urban Spatial Structure of the Largest Russian Cities
    • Ekaterina Saveleva
    2020

    The study presented within this dissertation involves the analysis of the relationship between urban spatial structure and travel patterns in the largest Russian cities. It is an empirical investigation of how the spatial structure, formed during the Soviet and post-Soviet periods, affects the travel patterns in the largest cities of contemporary Russia. It aims to determine what measures, both urban structure and transportation related, are suitable for such urban form to introduce most sustainable mobility patterns. The dissertation examines in detail how urban form and travel are interlinked, and how mobility patterns are created through many factors, not the last of which is the built environment. It provides a review of theoretical model of interaction between urban form and travel patterns followed by the empirical analysis of the link between urban spatial structure and travel patterns performed on a sample of the 13 largest Russian cities. The result of the GIS-based spatial analysis of the Russian cities‘ urban morphology comes in the form of quantitative dataset of various urban form characteristics, which are further used for the exploration of the interrelation between them and travel patterns in the largest Russian cities. Building on the findings regarding travel and urban form relationship in the largest Russian cities, the dissertation proposes both general directions for the development of cities with Soviet past and particular recommendations for the largest Russian cities, taking into account the current mobility situation, the specificities of their urban structure and the influence it has on the travel patterns.

  • Invasive Assessment of the Myocardial Microcirculation during Beating Heart Coronary Artery Bypass Grafting
    • Mariusz Kaszubowski
    • Marcin Hellmann
    2020 Pełny tekst Journal of Clinical Medicine

    Coronary artery bypass grafting may be associated with several cardiac complications, including ischemia, acute myocardial infarction, arrhythmias, or hemodynamic instability. Accumulating evidence suggests that well-developed coronary collateral circulation may protect against adverse effects, including myocardial ischemia. Assessment of myocardial microvascular perfusion is, therefore, of great clinical interest in beating heart surgery. In this paper, myocardial microvascular perfusion is continuously assessed on the beating heart using laser Doppler flowmetry in consecutive patients who underwent coronary artery bypass grafting procedures. No significant (p = 0.110) differences were found between the averaged perfusion signal (n = 42) at the baseline, during artery occlusion, or after reperfusion (732.4 ± 148.0 vs. 711.4 ± 144.1 vs. 737.0 ± 141.2, respectively). In contrast, significantly different (p < 0.001) mean perfusion signals (n = 12) were found (805.4 ± 200.1 vs. 577.2 ± 212.8 vs. 649.3 ± 220.8) in a subset of patients who presented with hemodynamic instability and myocardial ischemia. Additionally, a strong positive correlation between the plasma levels of high-sensitivity troponin I and perfusion decrease level after artery occlusion was found (r = 0.854, p < 0.001). This study argues that myocardial microvascular perfusion remains constant during coronary artery bypass grafting on the beating heart in advanced coronary artery disease. This phenomenon is most likely due to an extensive coronary collateral circulation.

  • Inverse Analysis as a Key Element of Safety Assessment under the Snow Load For The Large Suspension Roofs Structure
    • Krzysztof Żółtowski
    • Michał Drawc
    2020 Pełny tekst Archives of Civil Engineering

    The paper presents a concept and realization of monitoring system for the Silesian Stadium in Chorzow. The idea of the system lies in fusion of structure monitoring with a calibrated numerical FEM model [1]. The inverse problem is solved. On the base of measured selected displacements, the numerical FEM model of the structure combined with iterative method, develops the current snow load distribution. Knowing the load, we can calculate the forces and stresses in each element of the structure and thanks to this we can determine the safety thresholds and asses the owner. Test results and conclusions are presented

  • Inverse shadowing and related measures
    • Sergey Kryzhevich
    • Sergei Pilyugin
    2020 Pełny tekst Science China-Mathematics

    We study various weaker forms of the inverse shadowing property for discrete dynamical systems on a smooth compact manifold. First, we introduce the so-called ergodic inverse shadowing property (Birkhoff averages of continuous functions along an exact trajectory and the approximating one are close). We demonstrate that this property implies the continuity of the set of invariant measures in the Hausdorff metric. We show that the class of systems with ergodic inverse shadowing is quite broad; it includes all diffeomorphisms with hyperbolic nonwandering sets. Second, we study the so-called individual inverse shadowing (any exact trajectory can be traced by approximate ones, but this shadowing is not uniform with respect to the initial point of the trajectory). We demonstrate that this property is closely related to structural stability and Ω-stability of diffeomorphisms.

  • Investigating Analytics Dashboards’ Support for the Value-based Healthcare Delivery Model
    • Mona Isazad Mashinchi
    • Adegboyega Ojo
    • J. Francis Sullivan
    2020 Pełny tekst

    Improving the value of care is one of the essential aspects of Value-Based Healthcare (VBHC) model today. VBHC is a new HC delivery model which is centered on patient health outcomes and improvements. There is anecdotal evidence that the use of decision aid tools like dashboards can play a significant role in the successful implementation of VBHC models. However, there has been little or no systematic studies and reviews to establish the extent to which analytics dashboards are used to support patient care in a VBHC delivery context. This paper bridges this knowledge gap through a systematic review of the existing literature on dashboards in the HC domain. Our study reveals dashboard capabilities as an enabling tool for value improvements and provides insight into the design of dashboards. This study concludes by highlighting a few gaps, question, and need for research in the future.

  • Investigating Feature Spaces for Isolated Word Recognition
    • Povilas Treigys
    • Grazina Korvel
    • Gintautas Tamulevicius
    • Jolita Bernataviciene
    • Bożena Kostek
    2020

    The study addresses the issues related to the appropriateness of a two-dimensional representation of speech signal for speech recognition tasks based on deep learning techniques. The approach combines Convolutional Neural Networks (CNNs) and time-frequency signal representation converted to the investigated feature spaces. In particular, waveforms and fractal dimension features of the signal were chosen for the time domain, and three feature spaces were investigated for the frequency domain, namely: Linear Prediction Coefficient (LPC) spectrum, Hartley spectrum, and cochleagram. Due to the fact that deep learning requires an adequate training set size of the corpus and its content may significantly influence the outcome, thus for the data augmentation purpose, the created dataset was extended with mixes of the speech signal with noise with various SNRs (Signal-to-Noise Ratio). In order to evaluate the applicability of the implemented feature spaces for isolated word recognition task, three experiments were conducted, i.e., 10-, 70-, and 111-word cases were analyzed.

  • Investigating the Impact of Curing System on Structure-Property Relationship of Natural Rubber Modified with Brewery By-Product and Ground Tire Rubber
    • Łukasz Zedler
    • Xavier Colom
    • Javier Cañavate
    • Mohammad Saeb
    • Józef Haponiuk
    • Krzysztof Formela
    2020 Pełny tekst Polymers

    The application of wastes as a filler/reinforcement phase in polymers is a new strategy to modify the performance properties and reduce the price of biocomposites. The use of these fillers, coming from agricultural waste (cellulose/lignocellulose-based fillers) and waste rubbers, constitutes a method for the management of post-consumer waste. In this paper, highly-filled biocomposites based on natural rubber (NR) and ground tire rubber (GTR)/brewers’ spent grain (BSG) hybrid reinforcements, were prepared using two different curing systems: (i) sulfur-based and (ii) dicumyl peroxide (DCP). The influence of the amount of fillers (in 100/0, 50/50, and 0/100 ratios in parts per hundred of rubber) and type of curing system on the final properties of biocomposites was evaluated by the oscillating disc rheometer, Fourier-transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, swelling behavior, tensile testing, and impedance tube measurements. The results show, that the scorch time and the optimum curing time values of sulfur cured biocomposites are affected by the change of the hybrid filler ratio while using the DCP curing system, and the obtained values do not show significant variations. The results conclude that the biocomposites cured with sulfur have better physico-mechanical and acoustic absorption, and that the type of curing system does not influence their thermal stability. The overall analysis indicates that the difference in final properties of highly filled biocomposites cured with two different systems is mainly affected by the: (i) cross-linking efficiency, (ii) partial absorption and reactions between fillers and used additives, and (iii) affinity of additives to applied fillers.

  • Investigation into MPI All-Reduce Performance in a Distributed Cluster with Consideration of Imbalanced Process Arrival Patterns
    • Jerzy Proficz
    • Piotr Sumionka
    • Jarosław Skomiał
    • Marcin Semeniuk
    • Karol Niedzielewski
    • Maciej Walczak
    2020 Pełny tekst Advances in Intelligent Systems and Computing

    The paper presents an evaluation of all-reduce collective MPI algorithms for an environment based on a geographically-distributed compute cluster. The testbed was split into two sites: CI TASK in Gdansk University of Technology and ICM in University of Warsaw, located about 300 km from each other, both connected by a fast optical fiber Ethernet-based 100 Gbps network (900 km part of the PIONIER backbone). Each site hosted a set of 10~compute nodes interconnected locally by the InfiniBand switches with the traffic forwarded by specialized hardware: IBEX G40 - QDR InfiniBand RDMA based Extension Platform. A set of six all-reduce algorithms, consisting of two ring-based (including a PAP-aware pre-reduced ring), two binomial-tree based and two hierarchical ones, was tested for balanced and imbalanced process arrival patterns (PAPs). The results showed high and stable bandwidth with large data transmission latency of the branch connecting the remote sites (about 13 ms in comparison to 10 us locally), and for the tested algorithms there was an advantage of hierarchical approach, and then binomial tree. Finally, we also observed some performance increase in PAP-aware solution in comparison to its regular counterpart. The main conclusion is that for the distributed cluster environment with imbalanced PAPs, there is a need for designing new hierarchical algorithms with PAP-aware support.

  • Investigation of Parallel Data Processing Using Hybrid High Performance CPU + GPU Systems and CUDA Streams
    • Paweł Czarnul
    2020 Pełny tekst COMPUTING AND INFORMATICS

    The paper investigates parallel data processing in a hybrid CPU+GPU(s) system using multiple CUDA streams for overlapping communication and computations. This is crucial for efficient processing of data, in particular incoming data stream processing that would naturally be forwarded using multiple CUDA streams to GPUs. Performance is evaluated for various compute time to host-device communication time ratios, numbers of CUDA streams, for various numbers of threads managing computations on GPUs. Tests also reveal benefits of using CUDA MPS for overlapping communication and computations when using multiple processes. Furthermore, using standard memory allocation on a GPU and Unified Memory versions are compared, the latter including programmer added prefetching. Performance of a hybrid CPU+GPU version as well as scaling across multiple GPUs are demonstrated showing good speed-ups of the approach. Finally, the performance per power consumption of selected configurations are presented for various numbers of streams and various relative performances of GPUs and CPUs.

  • Investigation of praseodymium and samarium co-doped ceria as an anode catalyst for DIR-SOFC fueled by biogas
    • Beata Bochentyn
    • Piotr Błaszczak
    • Maria Gazda
    • A. Fuerte
    • S. F. Wang
    • Piotr Jasiński
    2020 Pełny tekst INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

    The Pr and Sm co-doped ceria (with up to 20 mol.% of dopants) compounds were examined as catalytic layers on the surface of SOFC anode directly fed by biogas to increase a lifetime and the efficiency of commercially available DIR-SOFC without the usage of an external reformer. The XRD, SEM and EDX methods were used to investigate the structural properties and the composition of fabricated materials. Furthermore, the electrical properties of SOFCs with catalytic layers deposited on the Ni-YSZ anode were examined by a current density-time and current density-voltage dependence measurements in hydrogen (24h) and biogas (90h). Composition of the outlet gasses was in situ analysed by the FTIR-based unit. It has been found out that Ce0.9Sm0.1O2-δ and Ce0.8Pr0.05Sm0.15O2-δ catalytic layers show the highest stability over time and thus are the most attractive candidates as catalytic materials, in comparison with other investigated lanthanide-doped ceria, enhancing direct internal reforming of biogas in SOFCs.

  • Investigation of rotational state-changing collisions of C2N− ions with helium
    • Jan Franz
    • Francesco Antonio Gianturco
    2020

    The cross sections for rotational inelastic collisions between atoms and a molecular anion can be very large, if the anion has a dipole moment. This makes molecular anions very efficient in cooling atomic gases. We address rotational inelastic collisions of Helium atoms with the molecular anion C2N–. Here we present preliminary calculations of the potential energy surface.

  • Investigation of the Dynamism of Nanosized SOA Particle Formation in Indoor Air by a Scanning Mobility Particle Sizer and Proton-Transfer-Reaction Mass Spectrometry
    • Klaudia Pytel
    • Renata Marcinkowska
    • Bożena Zabiegała
    2020 Pełny tekst MOLECULES

    Terpenes are VOCs of particular importance, since they are emitted from a wide range of indoor sources and are considered to be precursors of Secondary Organic Aerosol (SOA) formation. It has been proven that SOA particles, especially nanosized ones, pose a threat to human health. In this research, experiments with the application of an environmental chamber and real-time measurement techniques were carried out to investigate in a complimentary way the formation of monoterpene oxidation products and nanosized SOA particles initiated by monoterpene ozonolysis. Proton-Transfer-Reaction Mass Spectrometry with a Time-Of-Flight analyzer (PTR-TOF-MS) and a Scanning Mobility Particle Sizer (SMPS) were applied to determine in real time the dynamism of the formation of the corresponding terpene ozonolysis products and submicron SOA particles. Results proved that firstly, oxidation products were formed, and then, they underwent nucleation and condensation, forming particles whose diameters grew with time. The oxidation products formed were different depending on the type of terpenes applied. The comparison of the results obtained during the experiments with gaseous standard mixtures and real samples commonly present and used in indoor air revealed that the diversified chemical composition of the emission source had implications for both the particle formation initiated by the oxidation of essential oil components and the chemical reactions occurring via the oxidation process. With the instrumentation utilized, the concentration changes at the level of a few ppbv could be monitored

  • Investigation on the Sources and Impact of Trace Elements in the Annual Snowpack and the Firn in the Hansbreen (Southwest Spitsbergen)
    • Andrea Spolaor
    • Beatrice Moroni
    • Bartłomiej Luks
    • Adam Nawrot
    • Marco Roman
    • Catherine Larose
    • Łukasz Stachnik
    • Federica Bruschi
    • Krystyna Kozioł
    • Filip Pawlak
    • Clara Turetta
    • Elena Barbaro
    • Jean-Charles Gallet
    • David Cappelletti
    2020 Pełny tekst Frontiers in Earth Science

    We present a thorough evaluation of the water soluble fraction of the trace element composition (Ca, Sr, Mg, Na, K, Li, B, Rb, U, Ni, Co, As, Cs, Cd, Mo, Se, Eu, Ba, V, Ge, Ga, Cr, Cr, P, Ti, Mn, Zr, Ce, Zn, Fe, Gd, Y, Pb, Bi, Yb, Al, Nb, Er, Nd, Dy, Sm, Ho, Th, La, Lu, Tm, Pr, Tb, Fe, In, Tl) and their fluxes in the annual snowpack and the firn of the Hansbreen (a tidewater glacier terminating in the Hornsund fjord, southwest Spitsbergen). The trace element samples were obtained from a 3 m deep snow pit dug at the plateau of the glacier (450 m a.s.l.), and from a 2 m deep firn core collected from the bottom of the snow pit. The comparison of elemental fluxes and enrichment factors allowed us to constrain specific summer and wintertime deposition patterns of water soluble trace elements in the southern part of the Svalbard archipelago. Our results suggest that the chemical composition of the Hansbreen (and likely other glaciers where the summit is close to the equilibrium line) is mainly affected by summertime deposition of trace elements from local sources and some volatile elements, which may be transported into the Arctic when polar vortex is weak. The melting of the annual snowpack seems to have a minor influence on the overall chemical signature of the glacier ice.

  • Investigations of the Methods of Time Delay Measurement of Stochastic Signals Using Cross-correlation with the Hilbert Transform
    • Robert Hanus
    • Marcin Zych
    • Rafał Chorzępa
    • Anna Golijanek-Jędrzejczyk
    2020 Pełny tekst

    The article presents the results of simulation studies of four methods of estimating time delay for random signals using cross-correlation with the Hilbert Transform. Selected models of mutually delayed stochastic signals were used in the simulations, corresponding to the signals obtained from scintillation detectors in radioisotope measurements of liquid-gas two-phase flow. Standard deviations of the values of the individual functions were designated and compared, along with standard deviations of time delay estimates determined on their basis. The obtained results were compared with the results for classic cross-correlation function (CCF). It was found that for the analysed range of the signal-to-noise ratio (SNR): 0.2 ≤ SNR ≤ 5, the lowest values of standard deviation of time delay estimates were obtained for the CCFHT function (cross-correlation with the Hilbert Transform of the delayed signal).

  • Investigations of the Working Process in a Dual-Fuel Low-Emission Combustion Chamber for an FPSO Gas Turbine Engine
    • Serhiy Serbin
    • Badri Diasamidze
    • Marek Dzida
    2020 Pełny tekst Polish Maritime Research

    This investigation is devoted to an analysis of the working process in a dual-fuel low-emission combustion chamber for a floating vessel’s gas turbine. The low-emission gas turbine combustion chamber with partial pre-mixing of fuel and air inside the outer and inner radial-axial swirlers was chosen as the object of research. When modelling processes in a dual-flow low-emission gas turbine combustion chamber, a generalized method is used, based on the numerical solution of the system of conservation and transport equations for a multi-component chemically reactive turbulent system, taking into consideration nitrogen oxides formation. The Eddy-Dissipation-Concept model, which incorporates Arrhenius chemical kinetics in a turbulent flame, and the Discrete Phase Model describing the interfacial interaction are used in the investigation. The obtained results confirmed the possibility of organizing efficient combustion of distillate liquid fuel in a low-emission gas turbine combustion chamber operating on the principle of partial preliminary formation of a fuel-air mixture. Comparison of four methods of liquid fuel supply to the channels of radial-axial swirlers (centrifugal, axial, combined, and radial) revealed the advantages of the radial supply method, which are manifested in a decrease in the overall temperature field non-uniformity at the outlet and a decrease in nitrogen oxides emissions. The calculated concentrations of nitrogen oxides and carbon monoxide at the flame tube outlet for the radial method of fuel supply are 32 and 9.1 ppm, respectively. The results can be useful for further modification and improvement of the characteristics of dual-fuel gas turbine combustion chambers operating with both gaseous and liquid fuels.

  • Ion recognition properties of new pyridine-2,6-dicarboxamide bearing propeller-like pendant residues: multi-spectroscopic approach
    • Ewa Wagner-Wysiecka
    • Natalia Łukasik
    • Andrzej Okuniewski
    • Błażej Galiński
    2020 Pełny tekst MONATSHEFTE FUR CHEMIE

    The synthesis and ion binding properties of new amide derived from propeller-like tris(2-pyridyl)amine and 2,6-pyridinedicarboxylic acid chloride were described. Amide binds divalent metal cations: copper(II), nickel(II), zinc(II), and lead(II) in acetonitrile. In acetonitrile:water mixture (9:1 v/v) amide interacts only with copper(II) and nickel(II) cations forming complexes of 1:1 stoichiometry. It was found that the introduction of bulky, nitrogen donor atom bearing pendant groups can influence coordination mode of pyridine-2,6-dicarboxamides. The probable model of ligand-ion interactions is proposed on the basis of 1H NMR and FT-IR spectroscopy.

  • Ionic liquids in the microextraction techniques: the influence of ILs structure and properties
    • Kateryna Yavir
    • Karolina Konieczna
    • Łukasz Marcinkowski
    • Adam Kloskowski
    2020 TRAC-TRENDS IN ANALYTICAL CHEMISTRY

    Ionic liquids (ILs) are composed entirely of ions thus they possess unique properties, including negligible volatility, a liquid state in a broad range of temperatures and ability to change them depending on the chosen type of anion and cation, which make ILs unique and useful for many applications in sample preparation techniques. A deeper understanding of the nature of ILs and the impact of their structure on their parameters is the key to the success of conscious use of them as potential sorption media for a given purpose. This review describes the key physical and chemical properties of ILs in the context of their importance in sample preparation techniques. The review also presents selected combinations of ILs with solid-phase microextraction, SPME; single drop microextraction, SDME; dispersive liquid-liquid microextraction, DLLME, in terms of the role of ILs properties in a given technique.

  • Iron doped manganese cobaltite spinel coatings produced by electrophoretic co-deposition on interconnects for solid oxide cells: Microstructural and electrical characterization
    • Elisa Zanchi
    • Sebastian Molin
    • A Sabato
    • B Talic
    • Grzegorz Cempura
    • A Boccaccini
    • F Smeacetto
    2020 JOURNAL OF POWER SOURCES

    We report a systematic microstructural and electrical characterization of iron doped Mn–Co spinel coatings processed by electrophoretic co-deposition of Mn1.5Co1.5O4 and Fe2O3 powders on Crofer 22 APU and AISI 441 steel substrates. Iron addition to Mn–Co spinel coating leads to a reduction of the area specific resistance on both substrates, after 3200 h at 750 °C. The Fe doped Mn–Co coating both leads to a thinner oxide scale and reduces the sub scale oxidation for the Crofer 22 APU substrate. Fe doped Mn–Co on AISI 441 shows both a thicker oxide scale and low area specific resistance values, likely due to a doping effect of the oxide scale by minor alloying elements. The different mechanisms by which iron doping of Mn–Co spinels can influence elemental interdiffusion at the steel-oxide scale-coating interfaces and relative contributions to the overall area specific resistance are evaluated by means of advanced electron microscopy. The promising results are further confirmed in a cell test, where the Fe doped MnCo coated interconnect does not induce any degradation of the oxygen electrode, proving its efficiency.

  • Is Artificial Intelligence Ready to Assess an Enterprise’s Financial Security?
    • Oleksandr Melnychenko
    2020 Pełny tekst Journal of Risk and Financial Management

    This study contributes to the literature on financial security by highlighting the relevance of the perceptions and resulting professional judgment of stakeholders. Assessing a company’s financial security using only economic indicators—as suggested in the existing literature—would be inaccurate when undertaking a comprehensive study of financial security. Specifically, indices and indicators based on financial or managerial reporting calculated at any particular point in time, provide only a superficial understanding—and may even distort the overall picture. It has also been suggested that expert assessment is the most objective method, although it has disadvantages related to individual cognitive limitations. These limitations are not particular to artificial intelligence, which could assess an enterprise’s financial security in a less biased way. However, by only imitating human behavior, it is not able to perceive and evaluate with intuition the dynamics of the company’s development and holistically assess the financial condition—despite the possibility of learning and forecasting—because artificial intelligence is not able to think and predict, which, in an enterprise, is the most important skill of a manager. Therefore, the risk of developing artificial intelligence to assess a firm’s financial security lies in a biased assessment of the enterprise’s activities in general—and its financial security in particular.

  • Is sequential batch reactor an efficient technology to protect recipient against non-steroidal anti-inflammatory drugs and paracetamol in treated wastewater?
    • Katarzyna Kołecka
    • Magdalena Gajewska
    • Stanisław Cytawa
    • Piotr Stepnowski
    • Magda Caban
    2020 BIORESOURCE TECHNOLOGY

    The tested facility was a wastewater treatment plant (WWTP) in Swarzewo, where the wastewater treatment takes place in aeration chambers with activated sludge using sequential batch reactors (SBRs). The concentration of the following pharmaceuticals: ibuprofen, paracetamol, flurbiprofen, naproxen, diclofenac, and its metabolites 5OH-diclofenac and 4OH-diclofenac was tested in influents and effluents. Simultaneously, the conventional parameters were characterised. The removal of conventional pollutants was high (94.4–99.5%). At the same time, the removal of pharmaceuticals was variable. In the case of diclofenac and its metabolites, the concentration in the effluent was higher than in the influents. The risk quotients (RQs) calculated for analyzed pharmaceuticals suggest low environmental risk for selected species. However, negative impact for the biota due to the chronic presence of diclofenac cannot be excluded. It can be concluded that the SBRs, similarly to traditional flow activated sludge technology, are not efficient in the removal of target pharmaceuticals.

  • Issues relating to the efficient Application of passive solar protection in multi-family residential buildings
    • Katarzyna Zielonko-Jung
    • Janusz Marchwiński
    • Justyna Kobylarczyk
    2020 Pełny tekst Czasopismo Techniczne

    The following article is intended to discuss the issues concerning the introduction of passive measures aimed at improving solar protection in multi-family buildings. A system of classifying these methods into two groups of solutions (architectural and material-building) was applied. The first group includes issues concerning facade design, the spatial features of which (such as loggias, balconies and other overhangs) can be treated as one of the solar protection methods. The authors’ own studies are presented and expressed in a sequence of formulas. The formulas enable assessment of the effectiveness of the above elements, depending on external conditions. As far as the second group is concerned, material-construction solutions for building facades and roofs are discussed. The solutions mentioned include solar-control glazing, spatial shading elements (such as venetian blinds, roller blinds), roof and façade vegetation, and the thermal mass of the building. The essence of the functioning of the analysed solutions in relation to the characteristic functional specificity of multi-family buildings is discussed. Problematic areas of application of the above methods are indicated. As shown in the study, problematic areas may include a group of utilitarian-operating, economic and aesthetic issues, in the case of which the use of passive solutions encounters limitations. In conclusion, the possibilities for alleviating these limitations are highlighted. The authors’ own solutions presented in the following paper can contribute to energy savings and may thus prove beneficial for environmental reasons, thereby serving the aims of sustainable development.

  • Istnienie i regularność heteroklinicznych rozwiązań równania Allena-Cahna z anizotropowym operatorem eliptycznym
    • Karol Wroński
    2020 Pełny tekst

    Celem rozprawy jest udowodnienie dwóch twierdzeń dotyczących równań różniczkowych cząstkowych typu eliptycznego. Pierwsze mówi o regularności słabych rozwiązań pewnej klasy równań z operatorem eliptycznym, który pochodzi od wypukłej i anizotropowej G-funkcji spełniającej odpowiednie warunki wzrostu. To twierdzenie jest pewnym uogólnieniem znanych wyników z izotropowymi warunkami wzrostu na przypadek operatorów anizotropowych. Drugie twierdzenie przedstawione w rozprawie jest przykładem w jaki sposób można zastosować uzyskane wyniki o regularnosci słabych rozwiązań. Mówi ono o istnieniu heteroklinicznych rozwiązań problemu typu Allena-Cahna z operatorem anizotropowym. Jest ono dowodzone poprzez zastosowanie metod wariacyjnych w specjalnie skonstruowanej podprzestrzeni przestrzeni Orlicza-Sobolewa pochodzącej bezpośrednio od G-funkcji z operatora eliptycznego.

  • Istota zamieszkiwania.
    • Agnieszka Kurkowska
    2020

    Obiekt architektoniczny wyrasta i wrasta. To kolejno po sobie następujące etapy naturalnego rozwoju procesu zamieszkiwania w aspekcie projektowania i realizacji, a następnie użytkowania obiektu architektonicznego. Wykonane ideowe rzeźby architektoniczne, zgodnie z ich zamysłem ideowym i poprzedzającymi modele grafikami, ujawniają kilka odsłon zagadnienia. Obrazy ukazują podstawową potrzebę i konieczność zapewnienia sobie przez wszelkie organizmy żywe, w tym w szczególności przez człowieka, bezpiecznej kryjówki. Metaforyczne wyobrażenia archetypicznej formy schronienia pokazuje jej adaptowalność do różnorodnych uwarunkowań. Kontekst stanowi zadanie problemowe, na które odpowiedzią jest konkretna forma schronienia, spasowana do swojego otoczenia i odpowiadająca zastanej sytuacji przestrzennej. Najbardziej oczywiste, a dotyczące formowania przestrzeni zamieszkiwania, archetypy funkcjonujące w kulturze odnoszą się do schronienia. Jego forma, pierwotnie determinowana funkcją, zapewniała fizycznie i informowała symbolicznie mieszkańców o bezpieczeństwie. Wizualne wpisanie obiektów skonstruowanych przez człowieka w ich naturalne otoczenie przyrodnicze stanowi znak zamieszkania, obrazuje miejsce przynależności i pozwala przechowywać ważne ślady i znaki w pamięci jako wyobrażeniową reprezentację miejsca pochodzenia i przebywania. Czym jest lub powinien być Dom, jest zagadnieniem bliższym rozważaniom filozoficznym lub socjologicznym. Człowiek, poprzez zamieszkiwanie, zabezpiecza zasadniczą potrzebę schronienia oraz realizuje różnorodne potrzeby towarzyszące.

  • Iterative learning approach to active noise control of highly autocorrelated signals with applications to machinery noise
    • Adam Lasota
    • Michał Meller
    2020 IET Signal Processing

    This paper discusses the design and application of iterative learning control (ILC) and repetitive control (RC) for high modal density systems. Typical examples of these systems are structural and acoustical systems considered in active structural acoustic control (ASAC) and active noise control (ANC) applications. The application of traditional ILC and RC design techniques, which are based on a parametric system model, on systems with a high modal density has several important drawbacks: the design procedure is complex, the controllers require much computational power and the robustness of the controllers is low. This paper describes a novel strategy to design noncausal ILC and RC filters, which is especially suited for high modal density systems. Since it does not require a parametric system model, the novel strategy avoids several drawbacks of the traditional techniques: no cumbersome parametric model estimation is required; the ILC and RC controllers are robust to small changes of the poles and zeros of the controlled system; and the complexity of the ILC and RC control filters is restricted. A crucial element in the proposed strategy is the noncausal filtering in the ILC and RC controllers, which requires the availability of a trigger signal to announce a new ILC trial or RC period in advance. A numerical validation on a simulation model proves the potential of the developed strategy.

  • Izolacja i identyfikacja naturalnych substancji barwiących obecnych w tkaninach grobowych
    • Magdalena Śliwka-Kaszyńska
    2020

    .

  • Jaką rolę pełni i czego oczekujemy od telekomunikacji?
    • Józef Woźniak
    2020

    Zaprezentowano podstawowe kierunki rozwoju telekomunikacji, zarówno w ujęciu historycznym jak też w kontekście rozwoju technologii informacyjno-komunikacyjnych. Wskazano na potrzebę zdefiniowania nowych usług komunikacji elektronicznej oraz przytoczono podstawowe informacje na temat polskiego i unijnego podej­ścia do kwestii usług. Przedstawiono podstawowe paradygmaty współczesnej telekomunikacji i teleinformatyki, wskazując też ich kluczowe problemy badawcze i wdrożeniowe. Słowa kluczowe: podstawowe osiągnięcia telekomunikacji, nowe usługi komunikacji elektronicznej, polskie i europejskie prawo telekomunikacyjne, paradygmaty współczesnej telekomunikacji, kluczowe problemy badawcze .

  • JAKOŚĆ USŁUG W ARCHITEKTURZE SIECI ASON/GMPLS A MECHANIZMY REZERWACJI ZASOBÓW
    • Arkadiusz Dumin
    • Sylwester Kaczmarek
    • Magdalena Młynarczuk
    2020 Pełny tekst Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W artykule przedstawiono mechanizmy rezerwacji zasobów w architekturze sieci ASON/GMPLS, która spełnia wymagania nowoczesnych sieci optycznych, a jednocześnie umożliwia sterowanie siecią z gwarancją jakości usług. W artykule porównano dwa mechanizmy rezerwacji zasobów z gwarancją jakości i podejściem typu POOL. Efektywność prezentowanych mechanizmów zweryfikowano metodą symulacji komputerowej w środowisku OMNeT++.

  • Justification of quasi-stationary approximation in models of gene expression of a self-regulating protein
    • Agnieszka Bartłomiejczyk
    • Marek Bodnar
    2020 Communications in Nonlinear Science and Numerical Simulation

    We analyse a model of Hes1 gene transcription and protein synthesis with a negative feedback loop. The effect of multiple binding sites in the Hes1 promoter as well as the dimer formation process are taken into account. We consider three, possibly different, time scales connected with: (i) the process of binding to/dissolving from a binding site, (ii) formation and dissociation of dimers, (iii) production and degradation of Hes1 protein and its mRNA. Assuming that the first two processes are much faster than the third one, using the Tikhonov theorem, we reduce in two steps the full model to the classical Hes1 model. In the intermediate step two different models are derived depending on the relation between the time scales of processes (i) and (ii). The asymptotic behaviour of the solutions of systems are studied. We investigate the stability of the positive steady state and perform some numerical experiments showing differences in dynamics of the considered models.

  • Kalendarium działalności środowiska Ruchu Społeczeństwa Alternatywnego 1980-1990
    • Wojciech Mazur
    • Michał Przyborowski
    • Krzysztof Skiba
    • Zbigniew Stybel
    • Janusz Waluszko
    2020

    Kalendarium obejmuje fragment historii Ruchu Społeczeństwa Alternatywnego z lat 1980-1990 (nie ujęto okresu do 2005 i dalej, jako wykraczającego poza zainteresowania IPN i ECS). Zostało stworzone przy współpracy kilkudziesięciu osób związanych z RSA i zredagowane przez jego uczestników na podstawie materiałów archiwalnych (m.in. z IPN), informacji w prasie oficjalnej i podziemnej (w tym własnej) oraz wspomnień uczestników wydarzeń

  • Kanał radiowy w sieciach WBAN
    • Sławomir Ambroziak
    2020

    Monografia poświęcona modelowaniu kanałów radiowych w sieciach WBAN, czyli sieciach radiokomunikacyjnych krótkiego zasięgu, obejmujących swoim działaniem ciało człowieka (lub zwierzęcia) i jego bezpośrednie otoczenie. Podano definicję sieci WBAN i ich klasyfikację. Opisano podstawowe zagadnienia związane z tymi sieciami z uwzględnieniem problematyki radiokomunikacyjnej, narzędzia statystyczne najczęściej stosowane do analizy wyników eksperymentalnych badań propagacji fal radiowych, modele i metody umożliwiające oszacowanie wartości parametrów kanału radiowego w sieciach WBAN różnego typu oraz wyniki badań eksperymentalnych prowadzonych przez autora, stanowiących istotny wkład w rozwój telekomunikacji. Odbiorcy: pracownicy naukowi, inżynierowie oraz studenci telekomunikacji, elektroniki i informatyki, jak również specjaliści z zakresu inżynierii biomedycznej.

  • Kaszubskie zamieszkiwanie. Studium
    • Agnieszka Kurkowska
    2020

    Graficzne, malarskie i fotograficzne przedstawianie przestrzeni zamieszkiwania poprzez obraz oraz formalne poprzez rzeźbę to poszukiwanie nowych środków wyrazu dla ukazania osobistych refleksji na temat domu i jego relacji środowiskowych. Stanowią dopełnienie pracy naukowej i projektowej. Cykl „kaszubskie zamieszkiwanie. studium” to efekt projektu stypendialnego (stypendium dla twórców kultury Marszałka Województwa Pomorskiego na 2020 rok II edycja) zrealizowanego w 2020 roku na Kaszubach. Zaprezentowany zbiór grafik, obrazów, rzeźb i fotografii to studium ujawniające przemyślenia, obserwacje i wyobrażenia domu osadzonego w regionie - wyrastającego z lokalnych uwarunkowań.

  • Katalizatory do konwersji metanu z dwutlenkiem węgla
    • Izabela Wysocka
    2020 Laboratorium

    W ratykule zawarto przegląd literatury w zakresie katalizatorów do suchego reformingu metanu.

  • Kinetics of cross-linking processes of fast-curing polyurethane system
    • Adrian Olejnik
    • Kamila Gosz
    • Łukasz Piszczyk
    2020 Pełny tekst THERMOCHIMICA ACTA

    This work focuses on the application of thermal analysis and kinetics investigations to analyze chemical processes during cross-linking of the complex fast-curing polyurethane system. Non-isothermal Differential Scanning Calorimetry (DSC) measurements were performed for both stoichiometric mixtures of polyol and isocyanate component and for mixture with large isocyanate excess. Isoconversional methods were used to calculate initial parameters for the multi-step procedure. Data were fitted according to autocatalytic Sestak- Berggren equation and activation energies and reaction orders were obtained. Those investigations led to the successful identification of three main reactions i.e. polyaddition, isocyanate deblocking and formation allophanate groups.

  • Kinetics of Cross-Linking Reaction of Epoxy Resin with Hydroxyapatite-Functionalized Layered Double Hydroxides
    • Zohre Karami
    • Mohammad Ganjali
    • Maryam Zarghamidehaghani
    • Mustafa Aghazadeh
    • Maryam Jouyandeh
    • Amin Esmaeili
    • Sajjad Habibzadeh
    • Ahmad Mohaddespour
    • . Inamuddin
    • Krzysztof Formela
    • Józef Haponiuk
    • Mohammad Saeb
    2020 Pełny tekst Polymers

    The cure kinetics analysis of thermoset polymer composites gives useful information about their properties. In this work, two types of layered double hydroxide (LDH) consisting of Mg2+ and Zn2+ as divalent metal ions and CO32− as an anion intercalating agent were synthesized and functionalized with hydroxyapatite (HA) to make a potential thermal resistant nanocomposite. The curing potential of the synthesized nanoplatelets in the epoxy resin was then studied, both qualitatively and quantitatively, in terms of the Cure Index as well as using isoconversional methods, working on the basis of nonisothermal differential scanning calorimetry (DSC) data. Fourier transform infrared spectroscopy (FTIR) was used along with X-ray diffraction (XRD) and thermogravimetric analysis (TGA) to characterize the obtained LDH structures. The FTIR band at 3542 cm−1 corresponded to the O–H stretching vibration of the interlayer water molecules, while the weak band observed at 1640 cm-1 was attributed to the bending vibration of the H–O of the interlayer water. The characteristic band of carbonated hydroxyapatite was observed at 1456 cm−1. In the XRD patterns, the well-defined (00l) reflections, i.e., (003), (006), and (110), supported LDH basal reflections. Nanocomposites prepared at 0.1 wt % were examined for curing potential by the Cure Index as a qualitative criterion that elucidated a Poor cure state for epoxy/LDH nanocomposites. Moreover, the curing kinetics parameters including the activation energy (Eα), reaction order, and the frequency factor were computed using the Friedman and Kissinger–Akahira–Sunose (KAS) isoconversional methods. The evolution of Eα confirmed the inhibitory role of the LDH in the crosslinking reactions. The average value of Eα for the neat epoxy was 54.37 kJ/mol based on the KAS method, whereas the average values were 59.94 and 59.05 kJ/mol for the epoxy containing Zn-Al-CO3-HA and Mg Zn-Al-CO3-HA, respectively. Overall, it was concluded that the developed LDH structures hindered the epoxy curing reactions.

  • Kinetics of molecular decomposition under irradiation of gold nanoparticles with nanosecond laser pulses—A 5-Bromouracil case study
    • Telma S. Marques
    • Robin Schürmann
    • Kenny Ebel
    • Christian Heck
    • Małgorzata Śmiałek-Telega
    • Samuel Eden
    • Nigel J. Mason
    • Ilko Bald
    2020 Pełny tekst JOURNAL OF CHEMICAL PHYSICS

    ABSTRACT Laser illuminated gold nanoparticles (AuNPs) efficiently absorb light and heat up the surrounding medium, leading to versatile applications ranging from plasmonic catalysis to cancer photothermal therapy. Therefore, an in-depth understanding of the thermal, optical, and electron induced reaction pathways is required. Here, the electrophilic DNA nucleobase analog 5-Bromouracil (BrU) has been used as a model compound to study its decomposition in the vicinity of AuNPs illuminated with intense ns laser pulses under various conditions. The plasmonic response of the AuNPs and the concentration of BrU and resulting photoproducts have been tracked by ultraviolet and visible (UV–Vis) spectroscopy as a function of the irradiation time. A kinetic model has been developed to determine the reaction rates of two parallel fragmentation pathways of BrU, and their dependency on laser fluence and adsorption on the AuNP have been evaluated. In addition, the size and the electric field enhancement of the decomposed AuNPs have been determined by atomic force microscopy and finite domain time difference calculations, respectively. A minor influence of the direct photoreaction and a strong effect of the heating of the AuNPs have been revealed. However, due to the size reduction of the irradiated AuNPs, a trade-off between laser fluence and plasmonic response of the AuNPs has been observed. Hence, the decomposition of the AuNPs might be limiting the achievable temperatures under irradiation with several laser pulses. These findings need to be considered for an efficient design of catalytic plasmonic systems.

  • Kinetics of pollutants removal in vertical and horizontal flow constructed wetlands in temperate climate
    • Magdalena Gajewska
    • Katarzyna Skrzypiec
    • Krzysztof Jóźwiakowski
    • Zbigniew Mucha
    • Włodzimierz Wójcik
    • Agnieszka Karczmarczyk
    • Piotr Bugajski
    2020 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT

    This paper reports a comparative study on kinetics of organic matter expressed as BOD5 and nitrogen removal in constructed wetlands operated in Poland. Analyzed data were collected at eight wetland systems, composed of subsurface flow beds: horizontal flow (HF) and vertical flow (VF), in different number and sequences. The analysis involved particularly mass removal rates (MRR) and first-order removal rate coefficients of BOD5 and total nitrogen (kA and kv for VF and HF filters, respectively, and k20 as a parameter averaged for a temperature of 20 °C). It was found that the higher the load of pollutants applied to the beds, the higher MRR values were obtained. The average k-rates in analyzed systems were mostly lower than those reported in the literature, especially in the case of total nitrogen. Its removal obtained in horizontal flow beds was kv = 0.002–0.042 d−1, while in vertical flow systems kA varied from 0.007 m d−1 to 0.0037 m d−1. According to data given by previous studies, first-order reaction rates for nitrogen removal varied in range from kv = 0.048 d−1 to kv = 0.19 d−1 and kA from 0.007 to 0.1 m d−1 in HF and VF beds, respectively. Regarding BOD5 shown in literature, removal rate kv for HF beds varied from 0.071 to 6.11 d−1, and kA for VF beds varied from 0.019 to 1.0 m d−1, while in this study lower k-rates were obtained: kv = 0.005–0.085 d−1 and kA = 0.015–0.130 m d−1. Relatively long monitoring period, for some of constructed wetland up to 16 years, resulted in good data set and enables creation of the graphs, which could be helpful in evaluation and designing of constructed wetlands for PE bigger than 50, in moderate climate conditions.

  • KLASYFIKACJA SYGNAŁU EKG PRZY UŻYCIU KONWOLUCYJNYCH SIECI NEURONOWYCH
    • Maria Ferlin
    2020 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    Podniesienie jakości i zautomatyzowanie procesu diagnozy jest istotnym elementem rozwoju medycyny i samokontroli stanu zdrowia pacjentów. Od dłuższego czasu istnieją i są stosowane różne metody analizy i klasyfikacji sygnału EKG, jednak nie zawsze ich dokładność jest zadowalająca. Największym problemem jest trudność rozpoznania istniejącej nieprawidłowości, w przypadku gdy jej reprezentacja jest podobna do prawidłowej pracy serca np. przedwczesny skurcz komorowy. W ostatnich latach obserwujemy dynamiczny rozwój nowego narzędzia z rodziny metod sztucznej inteligencji - głębokich sieci neuronowych. Cechuje je duża selektywność klasyfikacji nawet najbardziej skomplikowanych sygnałów w postaci szeregów czasowych czy obrazów, często na podstawie cech niezauważalnych dla ludzkiego oka. W niniejszym artykule przedstawiono sposób analizy zarejestrowanego sygnału elektrycznej czynności mięśnia sercowego (EKG), na podstawie pojedynczego, wyodrębnionego cyklu pracy serca. Celem badania było zdiagnozowanie sześciu różnych typów ewolucji mogących świadczyć o występowaniu arytmii. Badania przeprowadzono z wykorzystaniem ogólnodostępnej bazy danych MIT-BIH Arrhythmia Database. W celu podniesienia jakości ekstrakcji cech analizowanego sygnału, dokonano jego dekompozycji czasowo - przestrzennej przy wykorzystaniu transformacji falkowej. W rezultacie uzyskano zadowalające wyniki klasyfikacji: dokładność 92,4% i swoistość (zdolność do wykrycia braku cechy) 96,5%. Osiągnięte wyniki potwierdzają skuteczność systemu automatycznej klasyfikacji cyklów pracy serca, mogącego wspomóc lekarzy w procesie żmudnej analizy dużej liczby zarejestrowanych danych.

  • Klasztor dominikanów przy kościele św. Piotra i Pawła w Chełmnie. Stan zachowania na początku XIX w. i zagospodarowanie terenu po jego rozbiórce
    • Piotr Samól
    2020 Tabularium Historiae

    Celem artykułu jest przestrzenna rekonstrukcja zburzonego w latach 30. XIX w. klasztoru dominikanów w Chełmnie. Podstawą studiów są prowadzone przez autora badania architektoniczne oraz szeroka kwerenda archiwalna, która pozwoliła odnaleźć nowe źródła do dziejów obiektu (plany administracji pruskiej w związku z kasatą lat 30. XIX w. oraz akta budowlane gminy protestanckiej osadzonej w kościele po odebraniu go katolikom). W artykule omówiono dotychczasowy stan badań i podjęto polemikę z najnowszą pracą M. Jakubek-Raczkowskiej, J. Raczkowskiego i P. Olińskiego dotyczącej klasztorów na ziemi chełmińskiej. Wykazano, że możliwe jest ustalenie relacji przestrzennych i układu pomieszczeń w klasztorze w latach 30. XIX w., a także - dzięki konfrontacji źródeł pisanych z wynikami badań architektonicznych - badania nad wcześniejszymi przekształceniami przestrzennymi zabudowań (co jednak wykracza poza zakres artykułu). Wyniki badań stanowić będą podstawę ewentualnie prowadzonych w przyszłości badań archeologicznych, a także uzupełniają istotny brak wiedzy o zabudowie mendykantów w Chełmnie.

  • Knowledge management and factors influencing its implementation in small KIBS firms – evidence from Poland
    • Małgorzata Zięba
    • Ettore Bolisani
    • Enrico Scarso
    2020 Pełny tekst

    Purpose – Even if the notion of knowledge management (KM) has been introduced more than three decades ago, the application of this concept in the context of small firms has still not been sufficiently explored. The relatively few contributions, however, agree on the fact that small companies do not manage knowledge the same way as their larger counterparts. In order to fill this gap, the present paper aims to the investigate the if and how different aspects of knowledge management in small enterprises offering knowledge-intensive business services (KIBS) – such as: type of adopted KM practices, barriers to KM implementation and use – are related with some characteristics of the companies such as: their size, the business sector they belong, the kind of adopted strategic knowledge approach followed. Specifically, paper examines some features of KM in companies belonging to various KIBS sectors (ICT, architectural and engineering services, professional services, R&D services and marketing and communication services) in Poland. The findings are based on a quantitative survey conducted among 104 small companies of this type. Investigated KM-related aspects were: the role played by knowledge and KM, the KM practices adopted, the factors that have hindered the adoption of such practices, the way they are used. KIBS companies were investigated because knowledge and its management are vital for their operations and they are perceived as intensive users of KM tools and practices. The findings of the survey show that the approaches to KM followed by small KIBS companies results to be rather differentiated. Concerning the factors that influence the KM approach adopted by the individual company, the size and the kind of followed strategy help in explaining the differences between companies more than the sector of belonging. In particular, the size seems to act as a constraint (in terms of number of adopted practice and of role of promoters) while the kind of strategy as an enabler (a more reflected strategy is connected with a greater number of adopted practices). The study offers food for thought about KM features in the KIBS sector and moreover, it contributes to a better understanding of KM in small enterprises. The knowledge presented in the paper may be of use to managers and owners wishing to better understand their KM practices and implement more suitable solutions.

  • Knowledge risks inherent in business sustainability
    • Susanne Durst
    • Małgorzata Zięba
    2020 Pełny tekst JOURNAL OF CLEANER PRODUCTION

    Since the connection between business sustainability and knowledge risks has not been established in the literature so far, this paper provides a conceptual framework to demonstrate the possible impact of various knowledge risks on business sustainability and offers potential ways to manage and overcome these risks. The aim of this conceptual paper is to address two main questions: What are the potential effects of knowledge risks on the three dimensions of sustainability in organizations? and How can organizations cope with knowledge risks to become truly sustainable? Taking insights from both the theories of knowledge management and business sustainability, it proposes a research agenda both for researchers and practitioners.

  • Knowledge-Based Virtual Modeling and Simulation of Manufacturing Processes for Industry 4.0
    • Syed Imran Shafiq
    • Cesar Sanin
    • Edward Szczerbicki
    2020 Pełny tekst CYBERNETICS AND SYSTEMS

    ABSTRACT Industry 4.0 aims at providing a digital representation of a production landscape, but the challenges in building, maintaining, optimizing, and evolving digital models in inter-organizational production chains have not been identified yet in a systematic manner. In this paper, various Industry 4.0 research and technical challenges are addressed, and their present scenario is discussed. Moreover, in this article, the novel concept of developing experience-based virtual models of engineering entities, process, and the factory is presented. These models of production units, processes, and procedures are accomplished by virtual engineering object (VEO), virtual engineering process (VEP), and virtual engineering factory (VEF), using the knowledge representation technique of Decisional DNA. This blend of the virtual and physical domains permits monitoring of systems and analysis of data to foresee problems before they occur, develop new opportunities, prevent downtime, and even plan for the future by using simulations. Furthermore, the proposed virtual model concept not only has the capability of Query Processing and Data Integration for Industrial Data but also real-time visualization of data stream processing.

  • KOMPUTER W LABORATORIUM VS LABORATORIUM W KOMPUTERZE
    • Ewa Kozłowska
    2020

    Abstract. In March 2020, all of the sudden, university teachers have been made to run all the classes remotely. But, how to deal with lab classes for future engineers? Different aspects of teaching labs on Moodle, that should be taken in consideration, are not only connected with the content of the class, but also with transferring the knowledge and materials to the students in a way that would avoid distractions and help students absorb the knowledge most effectively.