Nowe zasoby w Repozytorium PK http://suw.biblos.pk.edu.pl/ Biblioteka Politechniki Krakowskiej lipinska@biblos.pk.edu.pl 60 <![CDATA[Modelowanie serii czasowych przepływów w krótkoterminowej prognozie hydrologicznej]]> Fri, 15 Jan 2021 12:22:43 +0100 Siuta, Tomasz
rodzaj: artykuł w czasopiśmie
Abstrakt: Cel pracy W niniejszym artykule przedstawiono przykład opracowania skutecznej prognozy krótkoterminowej w cza-sie rzeczywistym przepływów wezbraniowych w przekroju wodowskazowym wybranej zlewni różnicowej rzeki Wisły. Prognoza ta oparta jest na przepływach obserwowanych w przekrojach wejściowych i wyjścio-wym systemu rzecznego z dobowym opóźnieniem bez uwzględnienia jakichkolwiek danych opadowych. Materiał i metody W celu oceny jakości prognozy opracowano cztery typy modeli serii czasowych chwilowego natężenia prze-pływu dla przekroju wyjściowego Smolice na rzece Wiśle. Pierwszy typ modelu to konwencjonalna liniowa zależność autoregresyjna (AR), drugi-trójwarstwowa sieć neuronowa typu feedforward (SSN), trzeci -dwu-warstwowa rekurencyjna sieć neuronowa i czwarty- trójwarstwowa rekurencyjna sieć neuronowa (RNN). Wszystkie modele były kalibrowane i testowane w oparciu o dane historyczne w formie hydrogramów na-tężenia przepływu. Wyniki i wnioski Spośród wszystkich testowanych typów modeli najdokładniejszą prognozę wartości chwilowej natężenia przepływu w przekroju zamykającym zlewnię uzyskano za pomocą modelu RNN. Ten typ modelu miał również największą zdolność do generalizowania wyników wykazując podobną jakość prognozy w trzech niezależnych testach.]]>
<![CDATA[PEG-POSS star molecules blended in polyurethane with flexible hard segments: morphology and dynamics]]> Fri, 15 Jan 2021 10:32:53 +0100 Raftopoulos, Konstantinos N. ; Hebda, Edyta ; Grzybowska, Anna ; Klonos, Panagiotis A.; Kyritsis, Apostolos ; Pielichowski, Krzysztof
rodzaj: artykuł w czasopiśmie
Abstrakt: A star polymer with a polyhedral oligomeric silsesquioxanne (POSS) core and poly(ethylene glycol) (PEG) vertex groups is incorporated in a polyurethane with flexible hard segments in-situ during the polymerization process. The blends are studied in terms of morphology, molecular dynamics, and charge mobility. The methods utilized for this purpose are scanning electron and atomic force microscopies (SEM, AFM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and to a larger extent dielectric relaxation spectroscopy (DRS). It is found that POSS reduces the degree of crystallinity of the hard segments. Contrary to what was observed in a similar system with POSS pendent along the main chain, soft phase calorimetric glass transition temperature drops as a result of plasticization, and homogenization of the soft phase by the star molecules. The dynamic glass transition though, remains practically unaffected, and a hypothesis is formed to resolve the discrepancy, based on the assumption of different thermal and dielectric responses of slow and fast modes of the system. A relaxation α′, slower than the bulky segmental α and common in polyurethanes, appears here too. A detailed analysis of dielectric spectra provides some evidence that this relaxation has cooperative character. An additional relaxation g, which is not commonly observed, accompanies the Maxwell Wagner Sillars interfacial polarization process, and has dynamics similar to it. POSS is found to introduce conductivity and possibly alter its mechanism. The study points out that different architectures of incorporation of POSS in polyurethane affect its physical properties by different mechanisms.]]>
<![CDATA[Modified maximum power point tracking algorithm under time-varying solar irradiation]]> Fri, 15 Jan 2021 09:29:19 +0100 Yildirim, Mehmet Ali; Nowak-Ocłoń, Marzena
rodzaj: artykuł w czasopiśmie
Abstrakt: Solar photovoltaic (PV) energy is one of the most viable renewable energy sources, considered less polluting than fossil energy. However, the average power conversion efficiency of PV systems is between 15% and 20%, and they must operate with high efficiency. Photovoltaic cells have non-linear voltage–current characteristics that are dependent on environmental factors such as solar irradiation and temperature, and have low efficiency. Therefore, it becomes crucial to harvest the maximum power from PV panels. This paper aims to study and analyze the most common and well-known maximum power point tracking (MPPT) algorithms, perturb and observe (P&O) and incremental conductance (IncCond). These algorithms were found to be easy to implement, low-cost techniques suitable for large- and medium-sized photovoltaic applications. The algorithms were tested and compared dynamically using MATLAB/Simulink software. In order to overcome the low performance of the P&O and IncCond methods under time-varying and fast-changing solar irradiation, several modifications are proposed. Results show an improvement in the tracking and overall system efficiencies and a shortened response time compared with original techniques. In addition, the proposed algorithms minimize the oscillations around the maximum power point (MPP), and the power converges faster.]]>
<![CDATA[Quality assessment of compressed and resized medical images based on pattern recognition using a convolutional neural network]]> Fri, 15 Jan 2021 08:46:18 +0100 Urbaniak, Ilona; Wolter, Marcin
rodzaj: artykuł w czasopiśmie
Abstrakt: Given the explosive growth of the amount of medical image data being produced and transferred over networks every day, employing lossy compression and other irreversible image operations is inevitable. As expected, irreversible image coding may decrease image fidelity by introducing undesired artifacts, which may lead to an invalid diagnosis. The purpose of this study is to propose a no-reference model of assessing the quality of a degraded medical image resulting from irreversible coding, based on pattern recognition with the use of a convolutional neural network (CNN). This deep neural network consists of six convolutional layers followed by two fully connected ones for the final image classification. Such network geometry is a common choice for image classification problems nowadays. We aim to construct a model that is specialized for medical images and could serve as a predictor of image quality for algorithm performance analysis. This technique uses a CNN to classify shapes of randomly chosen grayscale intensities. The shapes and grayscale shadings were chosen with the intention to mimic structures and edges appearing in a medical image. Using the accuracy of a classifier, we attempt to quantitatively measure how the information content in an image deteriorates after applying irreversible operations and how this loss of information affects the ability/inability of the neural network to recognize the shapes. The technique may be used to study the performance of irreversible image coding techniques. Two irreversible operations are employed for image degradation: compression and interpolation. We show the difference of image quality resulting from JPEG and JPEG2000 compression algorithms followed by scaling using several interpolation techniques. The main result of this work is the development of a model to quantitatively measure image quality based on pattern recognition using a deep neural network. The presented model of quantitative assessment of medical image quality may be helpful in determining the thresholds for irreversible image post-processing algorithms parameters (i.e. quality factor in JPEG) in order to avoid misdiagnosis. Further investigation of this problem will involve a connection of the introduced method with specific pathologies and various medical image modalities.]]>
<![CDATA[Pretekst : zeszyty Zakładu Architektury Mieszkaniowej i Kompozycji Architektonicznej]]> Thu, 14 Jan 2021 14:40:15 +0100 rodzaj: redakcja numeru czasopisma
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<![CDATA[Forma architektoniczna, funkcja oraz potencjał zespołów budynków wielorodzinnych zbudowanych w XXI wieku w Krakowie na przykładzie osiedli Kurdwanów Nowy i Piaski Nowe]]> Thu, 14 Jan 2021 13:23:51 +0100 Woźniczka, Magdalena
rodzaj: artykuł w czasopiśmie
Abstrakt: Piaski Wielkie oraz Kurdwanów to dawne przedmieścia Krakowa, których przestrzeń uległa silnym zmianom w ostatnim półwieczu. Pierwsza fala przemian nastąpiła w latach 70. i 80. kiedy to wzniesiono osiedla Piaski Nowe i Kurdwanów Nowy. Dalszy wzrost liczby mieszkańców Krakowa w XXI wieku, przyczynił się do ponownego skierowania uwagi inwestorów na te obszary. Obecnie tereny te są intensywnie zabudowywane. W niektórych rejonach tempo rozwoju infrastruktury drogowej i usługowej jest wolniejsze niż budowa obiektów mieszkaniowych. Tendencję tę widać w Piaskach Nowych, których funkcjonowanie opiera się głównie na ubiegłowiecznej infrastrukturze. Istotne stało się zbadanie form występujących w osiedlach, ich funkcji i potencjału, co pozwoli prowadzić skuteczną politykę przestrzenną w ich obrębie. Artykuł charakteryzuje formy architektoniczne, układy oraz podstawowe funkcje zespołów mieszkaniowych powstałych w latach 1999–2019 w Piaskach Nowych i Kurdwanowie Nowym. Wykonane badania wykazały, że oba osiedla mają predyspozycję do bycia atrakcyjnymi miejscami zamieszkania. Przyczyniają się do tego istniejące zaplecze usług publicznych oraz rozwijające się usługi prywatne. Ważnym czynnikiem jest też położenie miedzy III i IV obwodnicą Krakowa. Analiza form architektonicznych uwidoczniła zmiany w sposobie kształtowania zabudowy – zauważalna jest tendencja do upraszczania brył. Przedstawione realizacje pokazują, że uproszczenie nie jest jednak równoznaczne z końcem możliwości w kreowaniu form. Jest jedynie drogą do nowych rozwiązań.]]>
<![CDATA[Optymalne projektowanie konstrukcji w przypadku utraty stateczności dynamicznej – zjawisko flatteru dla nadkrytycznych prędkości płynu : rozprawa doktorska]]> Thu, 14 Jan 2021 12:48:01 +0100 Flis, Justyna Anna
rodzaj: rozprawa doktorska
Abstrakt: W pracy analizowano zagadnienie optymalizacji w projektowaniu konstrukcji kompozytowych narażonych na utratę stateczności dynamicznej – zjawisko flatteru dla nadkrytycznych prędkości płynu. Analiza obejmuje dwa rodzaje konstrukcji: płyty prostokątne (wykonane z laminowanych wielowarstwowych materiałów kompozytowych oraz z porowatych funkcjonalnych materiałów gradientowych) i panele cylindryczne (laminowane wielowarstwowe materiały kompozytowe). Szczegółowo omówiono metody rozwiązywania zagadnień utraty stateczności dynamicznej (analityczne i numeryczne). Przedyskutowano także zjawiska częstotliwości drgań swobodnych oraz maksymalizacji wartości ciśnienia aerodynamicznego w celu rozwiązania zadań optymalizacji. Przeprowadzona w pracy analiza dotyczy struktur z różnymi parametrami geometrycznymi, warunkami brzegowymi, orientacją laminatu oraz konfiguracją rozkładu porowatości w funkcjonalnych materiałach gradientowych. Zaproponowano i zastosowano z powodzeniem nową formę zmiennych decyzyjnych w przypadku laminatów o dyskretnej orientacji włókien. Zadania optymalizacji rozwiązano zarówno analitycznie stosując pakiet symboliczny Mathematica (konstrukcja ze specyficznymi warunkami brzegowymi), jak i numerycznie przy użyciu metody elementów skończonych – pakiet NISA II (konstrukcja z dowolnymi warunkami brzegowymi).]]>
<![CDATA[Climate change impacts on contaminant loads delivered with sediment yields from different land use types in a Carpathian basin]]> Thu, 14 Jan 2021 11:40:13 +0100 Szalińska, Ewa; Zemełka, Gabriela; Kryłów, Małgorzata; Orlińska-Woźniak, Paulina; Jakusik, Ewa; Wilk, Paweł
rodzaj: artykuł w czasopiśmie
Abstrakt: Soil runoff and sediment transport are considered as an important vector for particle-bound contaminant transfer from source to receiving waters. Under changing climate conditions and rapid basin development, identification of sediment origins is critical for planning further action to reduce erosion effects, and further pollution to surface waters. The goal of this study was to distinguish sediment sources in a Carpathian basin (Wolnica River, southern Poland) and to perform source-oriented contaminant load estimations. Sediment yields (SYLD) and land use specific sediment yields (LUSY) were modeled with the use of the Macromodel DNS/SWAT (Discharge-Nutrients-Sea/Soil and Water Assessment Tool). Sorting of sediment sources was performed by the fingerprinting method using variability of the geochemical composition of soils (Pb, Zn, Cd, Cu, Mn, Ni, Fe, Hg, total N and P, Σ16 PAHs, and 137Cs) of four land use (LU) types: arable lands (A), grasslands (G), residential areas (R), and forests (F). Statistical analysis revealed six metals (Pb, Zn, Cd, Cu, Ni, and Hg) as fingerprint properties providing the best source discrimination in this basin. The contribution of particular land use origin assessed with the use of the mixing model varied in the range of 20–30%. Finally, estimation of land use specific contaminant loads in suspended sediments was performed as a result of a modeling and sediment fingerprinting combination. The final estimates revealed yearly LUSY values varying between 716 t/y for A, 12 t/y for F, and metal loads from 31 kg/y for Zn to values below 100 g/y for Cd and Hg. Long-term predictions (2046–2055) of the metal loads revealed an increase by 75% under the combined RCP 8.5 climate change and land use scenarios. These findings are of great value for land management in the Carpathian basins, especially with regards to the predicted increase of forest cover which significantly alters contaminant signals conveyed through the system.]]>
<![CDATA[Usuwanie przecieków w żelbetowych zbiornikach na wodę]]> Thu, 14 Jan 2021 10:45:29 +0100 Dąbrowski, Wojciech; Żaba, Tadeusz; Zielina, Michał
rodzaj: artykuł w czasopiśmie
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<![CDATA[Digital monument reconstruction in architectural studies: synthesis of research on the previously unknown form of the palace in Łobzów (Cracow) from the period of the rule of John III Sobieski]]> Thu, 14 Jan 2021 09:48:18 +0100 Pikulski, Piotr
rodzaj: artykuł w czasopiśmie
Abstrakt: The former palace in Łobzów, which currently houses the Faculty of Architecture of the Cracow University of Technology, has an exceedingly rich architectural history. Since the Middle Ages, it has gone through a series of changes that have significantly altered its form each time. Thanks to modern digital reconstruction technology, it was possible to recreate all of its architectural phases in the form of 3D models on the basis of archaeological studies and the analysis of historical materials. The models were then used to reconstruct the most probable appearance of the building during the period when the Polish king John III Sobieski lived there. Determining the most probable state of the palace’s preservation during King Sobieski’s rule, which had not been investigated thus far, was possible only because of the combining of traditional research methods with modern technology.]]>
<![CDATA[DOE application for analysis of tribological properties of the Al2O3/IF-WS2 surface layers]]> Thu, 14 Jan 2021 09:19:11 +0100 Korzekwa, Joanna; Fal, Michał; Gądek-Moszczak, Aneta
rodzaj: artykuł w czasopiśmie
Abstrakt: The article presents the effect of the processing parameters on tribological properties of aluminum oxide coatings Al2O3 doped with fullerene-like tungsten disulfide (IF-WS2) by design of experiment (DOE). Anodic oxidation of aluminum alloy was carried out in a ternary solution of SAS (sulfuric, adipic and oxalic acids) with IF-WS2. The thickness, geometric structure of the surface (SGP) and the tribological properties such as friction coefficient of tribological pair: Al2O3/IF-WS2 with polieteroeteroketon filled with graphite, carbon fiber and PTFE (named PEEK/BG) were investigated. The influence of electrolysis time and temperature on the tribological properties of coatings was studied using 2k factorial design. The stabilization of the friction coefficient indicates generation of steady anti-wear and anti-seizure Al2O3/IF-WS2 oxide coatings. DOE suggest i.e. high positive correlation between oxide thickness and time and temperature of the anodizing process]]>
<![CDATA[Technologies of essential oils]]> Thu, 14 Jan 2021 08:57:43 +0100 Rachwalik, Rafał; Kurowski, Grzegorz; Vogt, Elżbieta; Vogt, Otmar
rodzaj: książka
Abstrakt: The monograph presents methods for preparation, properties and applications of essential oils. It should be mentioned that at present, almost 3.000 plants containing essential oils are known, but the oils are obtained only from 300 of them. Laboratory and industrial methods of collection of essential oils are discussed in the monograph, as well as methods of investigation of their properties.Thus, it is focused on the most popular commercial essential oils used in food industry, cosmetic industry, pharmaceutical industry, as well as aromatherapy. Moreover, it gives examples of less known oils, but also important considering their properties. As a criterion for division into individual groups, the most popular of classification was adopted, taking into account the plant part, from which the essential oil may be extracted. Therefore, essential oils obtained from: blossoms and flower buds, fruits, seeds, leaves, stalks and twigs, from bark and directly from wood, from resins, roots and rhizomes, are distinguished.Additionally, exemplary chromatograms for commercial essential oils described in the monograph are presented.]]>
<![CDATA[Biologiczne oczyszczanie ścieków zawierających formaldehyd. Cz. II**. Oczyszczanie w warunkach niedotlenionych i beztlenowych. Wspomaganie fizyczno-chemiczne]]> Wed, 13 Jan 2021 14:25:12 +0100 Baczyński, Tomasz
rodzaj: artykuł w czasopiśmie
Abstrakt: Dokonano przeglądu literatury dotyczącej badań nad biologicznym oczyszczaniem ścieków zawierających formaldehyd w warunkach niedotlenionych i beztlenowych. Omówiono ścieżki degradacji formaldehydu oraz oddziaływanie inhibicyjne. Przedstawiono także wyniki badań nad wspomaganiem oczyszczania biologicznego metodami fizyczno-chemicznymi.]]>
<![CDATA[Biologiczne oczyszczanie ścieków zawierających formaldehyd. Cz. I. Charakterystyka ścieków i oczyszczanie w warunkach tlenowych]]> Wed, 13 Jan 2021 13:28:27 +0100 Baczyński, Tomasz
rodzaj: artykuł w czasopiśmie
Abstrakt: Przedstawiono przegląd literatury dotyczącej badań nad biologicznym oczyszczaniem ścieków zawierających formaldehyd. Podano ogólną charakterystykę tego związku oraz rodzajów ścieków, w których on występuje. Zestawiono oraz omówiono wyniki prac doświadczalnych nad biologicznym oczyszczaniem ścieków formaldehydowych przeprowadzonych w warunkach tlenowych, zarówno z nitryfikacją, jak i bez niej. Ponadto przedstawiono w zarysie ścieżki biodegradacji oraz oddziaływanie inhibicyjne formaldehydu w takich warunkach.]]>
<![CDATA[Comparison of CFD and multizone modeling from contaminant migration from a household gas furnace]]> Wed, 13 Jan 2021 11:52:18 +0100 Szczepanik-Scislo, Nina; Scislo, Lukasz
rodzaj: artykuł w czasopiśmie
Abstrakt: In Central and Eastern Europe, a growing popularity of gas heaters as the main source of heat and domestic hot water can be observed. This is the result of new laws and strategies for funding that have been put in place to encourage households to stop using coal and replace it with cleaner energy sources. However, there is a growing concern that gas furnaces are prone to malfunction and can be a threat to occupants through CO (carbon monoxide) generation. To see how a faulty gas furnace with a clogged exhaust may affect a household, a series of multizone and computational fluid dynamics (CFD) simulations were carried out using the CONTAM software and CFD0 editor created by the National Institute of Standards and Technology (NIST). The simulations presented different placements of the furnace and ventilation outlet in an attached garage. The results showed how the placement influenced contaminant migration and occupant exposure to CO. It changed the amount of CO that infiltrated to the attached house and influenced occupant exposure. The results may be used by future users to minimize the risk of CO poisoning by using the proper natural ventilation methods together with optimal placement of the header in the household. ]]>
<![CDATA[Assessment of the influence of preventive maintenance on the reliability and availability indexes of diesel locomotives]]> Wed, 13 Jan 2021 11:37:34 +0100 Szkoda, Maciej; Kaczor, Grzegorz; Pilch, Robert; Smolnik, Maksymilian
rodzaj: materiały konferencyjne w książce
Abstrakt: The article investigates the influence of the preventive maintenance on the reliability and availability indexes of the railway means of transport. The research was done using the method based on fault tree analysis (FTA) and the Monte Carlo simulation. The authors performed a cause and effect analysis of the occurrence of undesirable events during the operation of selected vehicles. They identified the weakest components of the rail vehicle that affect the downtime and mean availability most significantly. Specialised software including Weibull++, BlockSim and MiniTab aided calculations were used to illustrate the application the results of a modernisation project involving a 6Dg diesel locomotive, carried out in cooperation with the biggest Polish rail carrier. The evaluation of reliability and availability was based on real operation data of a selected sample of 75 locomotives. The obtained results indicate that the proposed solution has a wide applicability potential.]]>
<![CDATA[Hybrid bilayer PLA/chitosan nanofibrous scaffolds doped with ZnO, Fe3O4, and Au nanoparticles with bioactive properties for skin tissue engineering]]> Wed, 13 Jan 2021 11:12:27 +0100 Radwan-Pragłowska, Julia; Janus, Łukasz; Piątkowski, Marek; Bogdał, Dariusz; Matýsek, Dalibor
rodzaj: artykuł w czasopiśmie
Abstrakt: Burns affect almost half a million of Americans annually. In the case of full-thickness skin injuries, treatment requires a transplant. The development of bioactive materials that promote damaged tissue regeneration constitutes a great alternative to autografts. For this reason, special attention is focused on three-dimensional scaffolds that are non-toxic to skin cells and can mimic the extracellular matrix, which is mainly composed of nanofibrous proteins. Electrospinning, which enables the preparation of nanofibers, is a powerful tool in the field of biomaterials. In this work, novel hybrid poly (lactic acid)/chitosan biomaterials functionalized with three types of nanoparticles (NPs) were successfully developed. ZnO, Fe3O4, and Au NPs were investigated over their morphology by TEM method. The top layer was obtained from PLA nanofibers, while the bottom layer was prepared from acylated chitosan. The layers were studied over their morphology by the SEM method and their chemical structure by FT-IR. To verify their potential in burn wound treatment, the scaffolds’ susceptibility to biodegradation as well as moisture permeability were calculated. Also, biomaterials conductivity was determined in terms of electrostimulation. Finally, cytotoxicity tests were carried out by XTT assay and morphology analysis using both fibroblasts cell line and primary cells. The hybrid nanofibrous scaffolds displayed a great potential in tissue engineering.]]>
<![CDATA[New housing complexes in post-industrial areas in city centres in Poland versus cultural and natural heritage protection-with a particular focus on Cracow]]> Wed, 13 Jan 2021 10:10:30 +0100 Gyurkovich, Mateusz ; Gyurkovich, Jacek
rodzaj: artykuł w czasopiśmie
Abstrakt: The cityscape changes constantly, reflecting the socio-economic conditions of a given urbanised area—both globally and in any given country. Post-industrial buildings and complexes have been its important elements since the nineteenth century. At present, many of them are undergoing adaptive reuse. The oldest, which are parts of post-industrial heritage and define the local identity, are now located in city centres. Some are revitalised and often adapted into multi-family housing. This paper fills a gap in the research on revitalised areas in Polish city centres, especially the ones converted into housing. It notes the links between these projects with elements of urban green-blue infrastructure, as well as the methods of protection of the reused postindustrial heritage. Studies from 2000–2020 on Polish multi-family housing architecture prove that the quality of buildings and semi-public green spaces is becoming increasingly important to developers and buyers. Properly used and exposed post-industrial heritage can contribute to raising the attractiveness of such spaces. In combination with city greenery systems, they can form attractive townscape sequences, as proven by Cracow cases. The paper’s conclusions indicate that the preservation and exposition of post-industrial heritage in newly built housing complexes is affected by numerous factors. The most important of these are legal determinants based on both state-level and local law. Economic factors also play a major role, as they directly affect projects. The skills and talent of designers who can create unique proposals that expose surviving relicts and a given place’s genius loci even in the most restrictive of economic and legal conditions, are also not without significance.]]>
<![CDATA[Smart, tunable CQDs with antioxidant properties for biomedical applications-ecofriendly synthesis and characterization]]> Wed, 13 Jan 2021 09:10:52 +0100 Janus, Łukasz; Radwan-Pragłowska, Julia; Piątkowski, Marek; Bogdał, Dariusz
rodzaj: artykuł w czasopiśmie
Abstrakt: Carbon quantum dots (CQDs) are nanoobjects of a size below 10 nm. Due to their favorable features, such as tunable luminescence, unique optical properties, water solubility, and lack of cytotoxicity, they are willingly applied in biomedicine. They can be obtained via bottom-up and top-down methods. However, to increase their quantum yield they must undergo post-processing. The aim of the following research was to obtain a new type of CQDs modified with a rhodamine b derivative to enhance their fluorescence performance without biocompability deterioration. For their preparation glucose was used as a precursor and four different carbonizing agents which affected semi- and final products luminescence properties. The ready nanomaterials were investigated over their chemical structure by FTIR and NMR, whereas morphology was investigated by the TEM method. Their optical properties were determined by UV–VIS spectroscopy. Fluorescence behavior, photo- and pH-stability, as well as solvatochromism showed their applicability in various biomedical applications due to the controlled properties. The samples exhibited excellent antioxidant activity and lack of cytotoxicity on L929 mouse fibroblasts. The results showed that proposed strategy enables preparation of the superior nanomaterials with outstanding luminescence properties such as quantum yield up to 17% which can be successfully applied in cell labelling, bioimaging, and theranostics.]]>
<![CDATA[Equalizing opportunities of first year students of engineering faculties by improving their knowledge in mathematics]]> Tue, 12 Jan 2021 15:34:46 +0100 Bednarz, Adam; Bistroń, Anna; Radoń, Małgorzata; Strycharz-Szemberg, Beata; Zajęcka, Małgorzata
rodzaj: materiały konferencyjne w książce
Abstrakt: In the paper we a study of three approaches to improving mathematical knowledge of first year students of engineering faculties implemented at Cracow University of Technology: inclusion of necessary topics in the course of higher mathematics, self-learning with the help of e-learning platform, and a complementary course.]]>
<![CDATA[Simulation as a tool to analyze changes in transition to smart mobility]]> Tue, 12 Jan 2021 14:49:59 +0100 Makarova, Irina; Pashkevich, Anton; Shubenkova, Ksenia
rodzaj: materiały konferencyjne w książce
Abstrakt: Sustainable transport is one of the basic systems of Smart City. Smart mobility implies three ways: efficient urban and transport infrastructure planning, transition to sustainable modes of transport (public, non-motorized modes of transport, electric transport) and minimizing the number of residents' trips. These ways were considered in the case study of Naberezhnye Chelny. To increase the attractiveness and efficiency of public transport, macromodel based simulation of city transport system was conducted. Our developed transport macromodel also allows predicting the influence of Internet of Everything integration into usual life. Simulation shows how public transport routes' optimization together with application of E-learning methods into educational system of Smart City can help to reduce traffic loads. To improve bottlenecks of the city transport system we have built the set of transport micromodels of problematic areas and suggested some managerial decisions. To solve the Last Mile Problem, the intelligent system to evaluate the bicycle routes is suggested. The idea is to integrate bicycle lane with public transport routes to inspire residents to use sustainable multimodal schemes of transportation despite private cars.]]>
<![CDATA[Metoda sztucznych sieci neuronowych w prognozowaniu bieżącym zapotrzebowania na wodę w Krakowie : rozprawa doktorska]]> Tue, 12 Jan 2021 14:21:50 +0100 Muszyński, Krzysztof
rodzaj: rozprawa doktorska
Abstrakt: Autor przedstawia budowę oraz możliwości sztucznych sieci neuronowych jako nowoczesnego narzędzia predykcyjnego. Uwzględniono podstawowe ich zalety, w porównaniu z tradycyjnymi metodami ARIMA. Opisano próby stosowania sztucznych sieci neuronowych jako modeli predykcyjnych oraz charakterystykę etapów budowy takiego modelu. Dysertacja jest próbą odpowiedzi na postawioną tezę, że sztuczne sieci neuronowe są alternatywnym (w stosunku do metod statystycznych), łatwym i szybkim w konstrukcji oraz prostym w użyciu narzędziem rekursywnym do prognozowania godzinowego zapotrzebowania na wodę i nadającym się do praktycznego wykorzystania w pracy przedsiębiorstwa wodociągowo-kanalizacyjnego w oparciu o podstawowe dane. Praca ta porusza zagadnienia budowy i przygotowania modelu predykcyjnego opartego na obliczeniach neuronowych oraz opisuje wyniki jego zastosowania oraz rozwiązuje następujące cele cząstkowe: • określenie optymalnych zbiorów danych opisujących proces rozbioru wody w Krakowie, • określenie optymalnej struktury sieci neuronowej służącej do prognozy zużycia wody w Krakowie, • określenie najodpowiedniejszego algorytmu uczenia sieci neuronowej służącej do prognozy zużycia wody w Krakowie, • zbadanie możliwości sztucznych sieci neuronowych do predykcji godzinowego zapotrzebowania na wodę w Krakowie, • zweryfikowanie pracy sieci, alternatywnym, dostępnym i znanym modelem prognostycznym ARIMA. Wyniki obliczeń zrealizowano wykorzystując własny algorytm opracowany w środowisku MATLAB. Uwzględniono szereg czasowy danych godzinowego zapotrzebowania na wodę oraz dane egzogeniczne: meteorologiczne i kalendarzowe do predykcji rozbioru godzinowego. Zastosowano metodę SSN do prognozy na podstawie niepełnego cyklu zużycia wody, z 3 kolejnych miesięcy.]]>
<![CDATA[3D hierarchical, nanostructured chitosan/PLA/HA scaffolds doped with TiO2/Au/Pt NPs with tunable properties for guided bone tissue engineering]]> Tue, 12 Jan 2021 13:43:32 +0100 Radwan-Pragłowska, Julia; Janus, Łukasz; Piątkowski, Marek; Bogdał, Dariusz; Matysek, Dalibor
rodzaj: artykuł w czasopiśmie
Abstrakt: Bone tissue is the second tissue to be replaced. Annually, over four million surgical treatments are performed. Tissue engineering constitutes an alternative to autologous grafts. Its application requires three-dimensional scaffolds, which mimic human body environment. Bone tissue has a highly organized structure and contains mostly inorganic components. The scaffolds of the latest generation should not only be biocompatible but also promote osteoconduction. Poly (lactic acid) nanofibers are commonly used for this purpose; however, they lack bioactivity and do not provide good cell adhesion. Chitosan is a commonly used biopolymer which positively affects osteoblasts' behavior. The aim of this article was to prepare novel hybrid 3D scaffolds containing nanohydroxyapatite capable of cell-response stimulation. The matrixes were successfully obtained by PLA electrospinning and microwave-assisted chitosan crosslinking, followed by doping with three types of metallic nanoparticles (Au, Pt, and TiO2). The products and semi-components were characterized over their physicochemical properties, such as chemical structure, crystallinity, and swelling degree. Nanoparticles' and ready biomaterials' morphologies were investigated by SEM and TEM methods. Finally, the scaffolds were studied over bioactivity on MG-63 and effect on current-stimulated biomineralization. Obtained results confirmed preparation of tunable biomimicking matrixes which may be used as a promising tool for bone-tissue engineering.]]>
<![CDATA[The short-circuit protections in hybrid systems with low-power synchronous generators]]> Tue, 12 Jan 2021 12:08:13 +0100 Rozegnał, Bartosz ; Albrechtowicz, Paweł ; Mamcarz, Dominik ; Radwan-Pragłowska, Natalia ; Cebula, Artur
rodzaj: artykuł w czasopiśmie
Abstrakt: Single-phase short-circuits are most often faults in electrical systems. The analysis of this damage type is taken for backup power supply systems, from small power synchronous generators. For these hybrid installations, there is a need for standard protection devices, such as fuses or miniature circuit breaker (MCB) analysis. Experimental research mentioned that a typical protective apparatus in low-voltage installations, working correctly during supplying from the grid, does not guarantee fast off-switching, while short-circuits occur during supplication from the backup generator set. The analysis of single-phase short-circuits is executed both for current waveform character (including sub-transient and transient states) and the carried energy, to show the problems with the fuses and MCB usage, to protect circuits in installations fed in a hybrid way (from the grid and synchronous generator set).]]>
<![CDATA[Facile synthesis of surface-modified carbon quantum dots (CQDs) for biosensing and bioimaging]]> Tue, 12 Jan 2021 11:02:20 +0100 Janus, Łukasz; Radwan-Pragłowska, Julia; Piątkowski, Marek; Bogdał, Dariusz
rodzaj: artykuł w czasopiśmie
Abstrakt: Recently, fluorescent probes became one of the most efficient tools for biosensing and bioimaging. Special attention is focused on carbon quantum dots (CQDs), which are characterized by the water solubility and lack of cytotoxicity. Moreover, they exhibit higher photostability comparing to traditional organic dyes. Currently, there is a great need for the novel, luminescent nanomaterials with tunable properties enabling fast and effective analysis of the biological samples. In this article, we propose a new, ecofriendly bottom-up synthesis approach for intelligent, surface-modified nanodots preparation using bioproducts as a raw material. Obtained nanomaterials were characterized over their morphology, chemical structure and switchable luminescence. Their possible use as a nanodevice for medicine was investigated. Finally, the products were confirmed to be non-toxic to fibroblasts and capable of cell imaging. ]]>
<![CDATA[Innovative environment-friendly interior finishing technologies resistant to mold growth]]> Tue, 12 Jan 2021 10:33:24 +0100 Czerski, Piotr; Radziszewska-Zielina, Elżbieta; Grześkowiak, Wojciech Ł.; Kwaśniewska-Sip, Patrycja; Krzyściak, Paweł
rodzaj: materiały konferencyjne w książce
Abstrakt: Excessive mold development in interior spaces can be the cause of health problems in their users, as well as of a decrease in the comfort of use of internal spaces. The aim of our study was the development of a service that can ensure the long-term elimination of the cause and effects of mold in buildings by using new compositions of materials and finish application techniques. For this purpose, the most mold-resistant variants of construction material compositions and the technology of their application were selected. The study features an analysis of 18 variants of samples taken from climatic boards with various building finishes, which were tested for resistance to three species of mold: A. versicolor, Ch. globosum and P. funiculosum, under different climate and humidity combinations. The results of the study pointed to the most effective anti-mold technology. One comprehensive solution that can improve the conditions of the use of interior spaces is an external wall interior thermal insulation application system that employs silicate and lime sheets.]]>
<![CDATA[Realization of PLM application integration with AR technology]]> Tue, 12 Jan 2021 10:32:53 +0100 Duda, J.; Oleszek, S.
rodzaj: artykuł w czasopiśmie
Abstrakt: The Augmented Reality (AR) can be used to simulate and improve production processes in a virtual manufacturing system before their physical implementation. These techniques make it possible to connect the real world with the virtual one in real time and in a threedimensional environment. Their effective application to the implementation of the product development phases would significantly limit its subsequent reworking and modifications. The difficulty, however, is to design and integrate AR with virtual production systems. The paper presents a proposal for a technical procedure for the implementation of the integration of a commercial PLM and a proprietary AR system.]]>
<![CDATA[Studium wykonalności dla inwestycji współfinansowanych ze środków UE]]> Tue, 12 Jan 2021 08:51:09 +0100 Dalman, Jolanta; Jędrzejewski, Zbigniew; Kalinowska, Ewa; Muszyński, Krzysztof; Piwowarczyk, Marcin
rodzaj: książka
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<![CDATA[Application of natural colorants in green polyethylene composites with lignocellulosic fillers: the influence of steam sterilization on mechanical properties and surface quality]]> Mon, 11 Jan 2021 14:49:28 +0100 Kufel, Anna; Kuciel, Stanisław
rodzaj: artykuł w czasopiśmie
Abstrakt: The concept of the presented research was to assess the applicability of natural colorants in dyeing biocomposites filled with natural fillers. As dyes, ground coffee, turmeric, couscous and ground paprika were used. Additionally, wood flour and walnut shell flour were added to improve strength parameters. The fillers were not dyed prior to processing, but the pigments were processed with the matrix and the filler. The optical observa-tion and the influence of steam sterilization on mechanical properties were carried out, taking into consideration esthetics and performance of the pro-duct. The results showed that natural colorants can be successfully used to dye composites. Low-density biocomposites with increased rigidity were obtained. Composites were characterized by lower tensile strength than neat green polyethylene which was approximately 18 MPa. The high result for tensile modulus was obtained for composition with coffee – it increased to 2045 MPa.]]>
<![CDATA[Tribo-mechanical properties of composites based on polyoxymethylene reinforced with basalt fiber and silicon carbide whiskers]]> Mon, 11 Jan 2021 13:21:40 +0100 Bazan, Patrycja; Nykiel, Marek; Kuciel, Stanisław
rodzaj: artykuł w czasopiśmie
Abstrakt: This paper presents an analysis of the hybrid reinforcement of polyoxymethylene composites. Basalt fibers and monocrystalline silicon carbide fibers were used as reinforcement. Basic tests of mechanical properties were carried out, such as the static tensile and flexural test. The tests were repeated under external factors, such as the influence of water aging and a wide range of exploitation temperatures. The materials were also subjected to tribological tests, that is, determination of the friction coefficient and the specific wear rate. Strength tests revealed an increase in the stiffness of the material as well as a reduction the friction coefficient and abrasive wear. The addition of monocrystalline fibers significantly limited water absorption, stabilized the strength properties in the water environment as well as provided better material's resistance to dynamic impact.]]>
<![CDATA[The potential of novel chitosan-based scaffolds in pelvic organ prolapse (POP) treatment through tissue engineering]]> Mon, 11 Jan 2021 13:10:24 +0100 Radwan-Pragłowska, Julia; Stangel-Wójcikiewicz, Klaudia; Piątkowski, Marek; Janus, Łukasz; Matýsek, Dalibor; Majka, Marcin; Amrom, Dalia
rodzaj: artykuł w czasopiśmie
Abstrakt: The growing number of female reproductive system disorders creates a need for novel treatment methods. Tissue engineering brings hope for patients, which enables damaged tissue reconstruction. For this purpose, epithelial cells are cultured on three-dimensional scaffolds. One of the most promising materials is chitosan, which is known for its biocompatibility and biodegradability. The aim of the following study was to verify the potential of chitosan-based biomaterials for pelvic organ prolapse regeneration. The scaffolds were obtained under microwave-assisted conditions in crosslinking reactions, using dicarboxylic acids and aminoacid as crosslinkers, including l-glutamic acid, adipic acid, malonic acid, and levulinic acid. The products were characterized over their physicochemical and biological properties. FT–IR analysis confirmed formation of amide bonds. The scaffolds had a highly porous structure, which was confirmed by SEM analysis. Their porosity was above 90%. The biomaterials had excellent swelling abilities and very good antioxidant properties. The cytotoxicity study was performed on vaginal epithelial VK2/E6E7 and human colon cancer HCT116 cell lines. The results showed that after certain modifications, the proposed scaffolds could be used in pelvic organ prolapse (POP) treatment.]]>
<![CDATA[ZnO nanorods functionalized with chitosan hydrogels crosslinked with azelaic acid for transdermal drug delivery]]> Mon, 11 Jan 2021 12:15:52 +0100 Radwan-Pragłowska, Julia; Janus, Łukasz; Piątkowski, Marek; Sierakowska, Aleksandra; Matysek, Dalibor
rodzaj: artykuł w czasopiśmie
Abstrakt: The growing number of people suffering from civilization diseases increases the amount of medication taken. Thus, novel methods for drug delivery must be developed which will constitute an alternative to oral administration. A new hope for patients bring transdermal drug delivery systems. To overcome skin barrier function, they must be prepared from materials which increase cell membrane permeability for the medication. Therefore, there is an increasing need for novel, advanced transdermal systems capable of controlled active substance release under specific stimuli. The aim of this research was to obtain novel hydrogel-based transdermal delivery systems through crosslinking process of chitosan using azelaic acid followed by doping with ZnO nanorods to enhance its drug sorption properties. Ready materials were investigated over their structure, morphology and durability. Drug loading capacity, controlled drug release ability and its kinetics were determined on medication used in treatment of cardiovascular system diseases - acetylsalicylic acid. Finally, lack of cytotoxicity was confirmed by XTT assay and cell morphology study carried out on L929 mouse fibroblasts. Obtained results show a great potential of the developed transdermal delivery systems in active substances administration through skin tissue and may help to protect digestive tract of the patients in the future.]]>
<![CDATA[Spatial differentiation of road safety in Europe based on NUTS-2 regions]]> Mon, 11 Jan 2021 11:16:24 +0100 Wachnicka, Joanna; Palikowska, Katarzyna; Kustra, Wojciech; Kiec, Mariusz
rodzaj: artykuł w czasopiśmie
Abstrakt: Road safety varies significantly across the regions in Europe. To understand the factors behind this differentiation and the effects they have, data covering 263 NUTS-2 (Nomenclature of Territorial Units for Statistics) regions across Europe (European Union and Norway) have been analysed. The assessment was made using Geographically Weighted Regression (GWR). As a dependent variable the Road Fatality Rate (RFR – number of fatalities in a given year per one million population of the region) was used. The GWR was developed from 2014 data and took account of variables that characterise economic, infrastructural and social development. The model was validated using 2016–2018 data. The following factors were found to be statistically significant: gross domestic product per person (GDPPC), number of passenger cars per inhabitant (MRPC), share of passenger vehicles (PPC), life expectancy at birth (LIFE), as well as variables related to the border of the regions, innerborder (IB) and outerborder (OB). Results suggest that the GWR has an advantage over the global linear model which does not address regional proximity. The model allows for identification of the differences in the level of road safety in regions, estimated on the basis of the RFR and the available data in Eurostat databases. This in turn allows for indicating regions in which activities to improve road safety should have the highest priority. The model shows a large spatial diversity of factors affecting the RFR, which indicates the need to take different actions to improve road safety depending on the region. The results suggest that the GWR model can be useful for predicting and more efficient management of road safety at the regional level in Europe.]]>
<![CDATA[Identyfikacja czynników ryzyka budowy i eksploatacji kolei próżniowej w Polsce]]> Mon, 11 Jan 2021 11:06:13 +0100 Iwaszczuk, Natalia; Łamasz, Bartosz ; Iwaszczuk, Aleksander
rodzaj: materiały konferencyjne w książce
Abstrakt: Ryzyko jest nieodłączną częścią procesów gospodarczych. Kolej próżniowa jest przedsięwzięciem bardzie narażonym na różnego typu zagrożenia, niż inne projekty transportowe, ze względu na brak doświadczenia w ich budowie. Łączą się tu ryzyka typowo budowlane i infrastrukturalne z zagrożeniami wykorzystania najnowszych technologii. Dlatego już na etapie tworzenia projektu należy dokonać identyfikacji czynników, które mogą stać się zagrożeniem zarówno dla realizacji projektu, jak i środowiska. W niniejszym opracowaniu czynniki ryzyka podzielono na dwie grupy, według kryterium źródeł ich pochodzenia: ryzyka zewnętrzne i ryzyka wewnętrzne. Na pierwszą grupę ryzyk inwestor (projektant) nie ma żadnego wpływu. Jednak nie oznacza to, że nie powinno się ich uwzględniać w dokumentacji projektowej. Świadomość istnienia poszczególnych rodzajów ryzyka jest bowiem podstawą przygotowania skutecznej strategii zarządzania ryzykiem, nastawionej na redukcję lub eliminację jego ewentualnego wpływu na przedsięwzięcie. Z kolei, ryzyka tkwiące wewnątrz podmiotu realizującego projekt inwestycyjny da się opanować, pod warunkiem wcześniejszego przygotowania odpowiedniej strategii zarządzania, która uwzględniać będzie różne rodzaje ryzyka i warianty radzenia sobie z nimi. Podobna analiza (z podziałem na ryzyka zewnętrzne i wewnętrzne) została też przeprowadzona dla etapu eksploatacji kolei próżniowej w Polsce. Jest ona tym bardzie ważna, że przewiduje się przewóz nie tylko ładunków, lecz również pasażerów, bezpieczeństwo życia i zdrowia których (jak i pracowników pracujących na kolei) jest największą wartością. Analizie został poddany cały kompleks obiektów kolei próżniowej, wraz z dworcami kolejowymi oraz stacjami przeładunkowymi i serwisowymi. Wskazano jakie metody zarządzania ryzykiem można wykorzystać i opracowano rekomendacje praktyczne dotyczące strategii zarządzania ryzykiem. Przygotowane w wariantowym ujęciu mogą one uchronić przed poniesieniem niezaplanowanych kosztów i strat.]]>
<![CDATA[Turkmenistan na globalnym rynku gazu: pozycja i strategie rozwoju]]> Mon, 11 Jan 2021 11:01:54 +0100 Iwaszczuk, Natalia; Iwaszczuk, Aleksander; Wolak, Jacek
rodzaj: materiały konferencyjne w książce
Abstrakt: Gaz ziemny to jeden z podstawowych nośników energii we współczesnej gospodarce. W dobie walki z ociepleniem klimatu pozostaje on jedynym paliwem kopalnym uznawanym za paliwo „czyste”, niepowodujące emisji gazów cieplarnianych oraz zmian klimatycznych. Z tego powodu w ostatnich latach wzrasta popyt na gaz ziemny wykorzystywany na różne cele gospodarcze. Z drugiej strony pojawiają się inne źródła pozyskiwania tego surowca, co wpływa na jego globalną podaż. Jednym z kluczowych dostawców gazu ziemnego na rynku globalnym jest Turkmenistan. Celem artykułu jest zbadanie obecnego i prognoza perspektywicznego potencjału tego kraju względem wydobycia i eksportu tego surowca. Ponadto, analiza sektora gazowniczego Turkmenistanu umożliwi opracowanie rekomendacji co do budowy strategii jego rozwoju. Jako metody badawcze wykorzystano: kompleksową analizę danych zastanych, analizę bibliograficzną, identyfikację czynników wpływających pozytywnie i negatywnie na rozwój sektora gazowniczego z wykorzystaniem metody SWOT.]]>
<![CDATA[Coumarin-modified CQDs for biomedical applications—two-step synthesis and characterization]]> Mon, 11 Jan 2021 10:28:37 +0100 Janus, Łukasz; Radwan-Pragłowska, Julia; Piątkowski, Marek; Bogdał, Dariusz
rodzaj: artykuł w czasopiśmie
Abstrakt: Waste biomass such as lignin constitutes a great raw material for eco-friendly carbon quantum dots (CQDs) synthesis, which find numerous applications in various fields of industry and medicine. Carbon nanodots, due to their unique luminescent properties as well as water-solubility and biocompatibility, are superior to traditional organic dyes. Thus, obtainment of CQDs with advanced properties can contribute to modern diagnosis and cell visualization method development. In this article, a new type of coumarin-modified CQD was obtained via a hybrid, two-step pathway consisting of hydrothermal carbonization and microwave-assisted surface modification with coumarin-3-carboxylic acid and 7-(Diethylamino) coumarin-3-carboxylate. The ready products were characterized over their chemical structure and morphology. The nanomaterials were confirmed to have superior fluorescence characteristics and quantum yield up to 18.40%. They also possessed the ability of biomolecules and ion detection due to the fluorescence quenching phenomena. Their lack of cytotoxicity to L929 mouse fibroblasts was confirmed by XTT assay. Moreover, the CQDs were proven over their applicability in real-time bioimaging. Obtained results clearly demonstrated that proposed surface-modified carbon quantum dots may become a powerful tool applicable in nanomedicine and pharmacy.]]>
<![CDATA[Modelling study of a catalytic fixed-bed reactor for direct synthesis of dimethyl ether: Performance analysis and process optimization]]> Mon, 11 Jan 2021 09:46:30 +0100 Cutillo, Enrico Alberto; D'Onofrio, Alfonso; Bizon, Katarzyna; Continillo, Gaetano
rodzaj: rozdział/fragment książki
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<![CDATA[Cell viability and collagen deposition on hydroxyapatite coatings formed on pretreated substrates]]> Fri, 08 Jan 2021 13:04:14 +0100 Yanovska, A.; Radwan-Pragłowska, J.; Piątkowski, M.; Janus, Ł.
rodzaj: artykuł w czasopiśmie
Abstrakt: A method of thermal deposition that involves localized high peak temperatures at the electrode-electrolyte interface was proposed for hydroxyapatite (HA) coatings deposition. Active surface layers were obtained by HA incorporation from the aqueous electrolyte into the substrate surface due to the decrease of HA solubility with increasing of substrate temperature. Commercially Ti-6Al-4V alloy (grade 4) substrates were pretreated by sandblasting combined with various chemical pre-treatments: 20% NaOH, 20% oxalic acid, and both. After both types of pre-treatment and HA thermal deposition, we can observe uniform coatings with a rough surface. HA presence was confirmed by X-ray Diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) analysis. According to received data, samples after 6.5 bar, one cycle of sandblasting and etching in 20% oxalic acid 2 h, 20% H3PO4 1 min as well as untreated samples showed the highest wettability. All measured contact angles are lower than 90°, which means that obtained HA surfaces are hydrophilic and indicates that the wetting of the surface is favorable, and the fluid will spread over a large area of the surface. Resazurin reduction assay showed satisfactory U2OS osteoblastic cell adhesion in 1 day of the experiment. There is no significant difference between non-treated polished surfaces and HA-covered with sandblasting pre-treatment. In contrast – the polished surface with HA coating demonstrates significantly less cell adhesion. It was confirmed low collagen production both in untreated and polished-HA surfaces in comparison with the sandblasted-HA ones. The obtained data suggest that roughness plays an important role in cell adhesion and proliferation, but HA coating provides additional stimuli for cell activity (collagen synthesis).]]>
<![CDATA[The study of physico-mechanical properties of polylactide composites with different level of infill produced by the FDM method]]> Fri, 08 Jan 2021 12:55:51 +0100 Gaweł, Anna; Kuciel, Stanisław
rodzaj: artykuł w czasopiśmie
Abstrakt: The aim of this study was to evaluate the changes in physical-mechanical properties of the samples manufactured by 3D printing technology with the addition of varying degrees of polylactide (PLA) infill (50, 70, 85 and 100%). Half of the samples were soaked in physiological saline. The material used for the study was neat PLA, which was examined in terms of hydrolytic degradation, crystallization, mechanical strength, variability of properties at elevated temperatures, and dissipation of mechanical energy depending on the performed treatment. A significant impact of the amount of infill on changeable mechanical properties, such as hydrolytic degradation and crystallization was observed. The FDM printing method allows for waste–free production of light weight unit products with constant specyfic strength.]]>
<![CDATA[Addendum to the paper “High‐order symmetric cubature rules for tetrahedra and pyramids”]]> Fri, 08 Jan 2021 10:58:25 +0100 Jaśkowiec, Jan; Sukumar, N.
rodzaj: artykuł w czasopiśmie
Abstrakt: In Jaśkowiec and Sukumar (Int J Numer Methods Eng., doi: 10.1002/nme.6528, 2020), we presented high‐order (p = 2–20) symmetric cubatures rules for tetrahedra and pyramids. This algorithm was sensitive to the initial location of the cubature nodes, and it did not converge for p > 11 over prisms and hexahedra (cubes). In this addendum, we resolve this issue and obtain high‐order symmetric rules over prisms and cubes. For the prism, we use the initial guess for the cubature rule as the tensor product of a cubature rule over a triangle and a univariate Gauss quadrature rule, and for the cube the initial guess is the tensor product of univariate Gauss quadrature rules. Verification and convergence tests are presented to affirm the accuracy of the cubature rules. On applying the cubature algorithm described in Jaśkowiec and Sukumar (Int J Numer Methods Eng., 121 (11), 2418‐2436, 2020), we also construct non‐symmetric high‐order (p = 2–20) cubature rules over prisms, cubes, and pyramids. In the Supplementary Materials, all cubature rules (128 digits of precision) are provided in a text file and in Matlab® format.]]>
<![CDATA[Application of pseudohomogeneous and heterogeneous models in assessing the behavior of a fluidized-bed catalytic reactor]]> Fri, 08 Jan 2021 09:25:32 +0100 Bizon, Katarzyna
rodzaj: artykuł w czasopiśmie
Abstrakt: Comparative analysis of the steady-state and transient properties of a bubbling fluidized-bed catalytic reactor obtained according to different mathematical models of the emulsion zone was performed to verify the commonly used assumption regarding the pseudohomogeneous nature of this zone. Four different mathematical models of the fluidized-bed reactor dynamics were formulated, based on different thermal and diffusional conditions at the gas-solid interface and within the catalyst pellet, namely the model based on the assumption of pseudohomogeneous character for the emulsion zone, and a group of two-scale models accounting for the heterogeneous character of this zone. It was demonstrated that, while the pseudohomogeneous model of the emulsion zone predicts almost identical behavior of the reactor at steady-state as the proposed heterogeneous models, it may fail in the prediction of the reactor start-up behavior, especially when dealing with highly exothermic processes run at relatively high fluidization velocity.]]>
<![CDATA[Characteristics of plastic waste processing in the modern recycling plant operating in Poland]]> Fri, 08 Jan 2021 08:56:21 +0100 Szostak, Elżbieta; Duda, Piotr; Duda, Andrzej; Górska, Natalia; Fenicki, Arkadiusz; Molski, Patryk
rodzaj: artykuł w czasopiśmie
Abstrakt: Although Poland is one of the leading recipients of the waste stream in the European Union (EU), it is at the same time below the average in terms of efficiency of their use/utilization. The adopted technological solutions cause waste processing rates to be relatively low in Poland. As a result, the report of the Early Warning and Response System (EWRS) of the EU indicated Poland as one of the 14 countries of the EU which are at risk in terms of possibility of achieving 50% recycling of waste. This article discusses the implemented technological solutions, and shows the profitability of the investment and the values of the process heat demand both for extractor and reactor. The experimental part analyzed the composition of the input and output of the process and compared it to the required fuel specifications. Attention was drawn to the need to improve the recycling process in order to increase the quality of manufactured fuel components. As potential ways of solving the problem of low fuel quality, cleaning the sorted reaction mass from solid particles and extending the technological line with a distillation column have been proposed. The recommended direction of improvement of the technology is also the optimization of the process of the reactor’s purification and removal of contaminants.]]>