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  • The occurrence and role of Nitrospira in nitrogen removal systems
    • Mohamad-Javad Mehrani
    • Dominika Sobotka
    • Przemysław Kowal
    • Sławomir Ciesielski
    • Jacek Mąkinia
    2020 Pełny tekst BIORESOURCE TECHNOLOGY

    Application of the modern microbial techniques changed the paradigm about the microorganisms performing nitrification. Numerous investigations recognized representatives of the genus Nitrospira as a key and predominant nitrite-oxidizing bacteria in biological nutrient removal systems, especially under low dissolved oxygen and substrate conditions. The recent discovery of Nitrospira capable of performing complete ammonia oxidation (comammox) raised a fundamental question about the actual role of Nitrospira in both nitrification steps. This review summarizes the current knowledge about morphological, physiological and genetic characteristics of the canonical and comammox Nitrospira. Potential implications of comammox for the functional aspects of nitrogen removal have been highlighted. The complex meta-analysis of literature data was applied to identify specific individual variables and their combined interactions on the Nitrospira abundance. In addition to dissolved oxygen and influent nitrogen concentrations, temperature and pH may play an important role in enhancing or suppressing the Nitrospira activity.

  • The ONETEP linear-scaling density functional theory program
    • Joseph C. A. Prentice
    • Jolyon Aarons
    • James C. Womack
    • Alice E. A. Allen
    • Lampros Andrinopoulos
    • Lucian Anton
    • Robert A. Bell
    • Arihant Bhandari
    • Gabriel A. Bramley
    • Robert J. Charlton
    • Rebecca J. Clements
    • Daniel J. Cole
    • Gabriel Constantinescu
    • Fabiano Corsetti
    • Simon Dubois
    • Kevin K. B. Duff
    • José María Escartín
    • Andrea Greco
    • Quintin Hill
    • Louis P. Lee
    • Edward Linscott
    • David D. O’Regan
    • Maximillian J. S. Phipps
    • Laura Ratcliff
    • Álvaro Ruiz Serrano
    • Edward W. Tait
    • Gilberto Teobaldi
    • Valerio Vitale
    • Nelson Yeung
    • Tim J. Zuehlsdorff
    • Jacek Dziedzic
    • Peter Haynes
    • Nicholas Hine
    • Arash Mostofi
    • Mike Payne
    • Chris-Kriton Skylaris
    2020 Pełny tekst JOURNAL OF CHEMICAL PHYSICS

    We present an overview of the ONETEP program for linear-scaling density functional theory (DFT) calculations with large basis set (planewave) accuracy on parallel computers. The DFT energy is computed from the density matrix, which is constructed from spatially localized orbitals we call Non-orthogonal Generalized Wannier Functions (NGWFs), expressed in terms of periodic sinc (psinc) functions. During the calculation, both the density matrix and the NGWFs are optimized with localization constraints. By taking advantage of localization, ONETEP is able to perform calculations including thousands of atoms with computational effort, which scales linearly with the number or atoms. The code has a large and diverse range of capabilities, explored in this paper, including different boundary conditions, various exchange– correlation functionals (with and without exact exchange), finite electronic temperature methods for metallic systems, methods for strongly correlated systems, molecular dynamics, vibrational calculations, time-dependent DFT, electronic transport, core loss spectroscopy, implicit solvation, quantum mechanical (QM)/molecular mechanical and QM-in-QM embedding, density of states calculations, distributed multipole analysis, and methods for partitioning charges and interactions between fragments. Calculations with ONETEP provide unique insights into large and complex systems that require an accurate atomic-level description, ranging from biomolecular to chemical, to materials, and to physical problems, as we show with a small selection of illustrative examples. ONETEP has always aimed to be at the cutting edge of method and software developments, and it serves as a platform for developing new methods of electronic structure simulation. We therefore conclude by describing some of the challenges and directions for its future developments and applications.

  • The Palais–Smale condition for the Hamiltonian action on a mixed regularity space of loops in cotangent bundles and applications
    • Luca Asselle
    • Maciej Starostka
    2020 Pełny tekst CALCULUS OF VARIATIONS AND PARTIAL DIFFERENTIAL EQUATIONS

    We show that the Hamiltonian action satisfies the Palais-Smale condition over a “mixed regular- ity” space of loops in cotangent bundles, namely the space of loops with regularity H^s, s ∈ (1/2, 1), in the baseand H^{1−s} in the fiber direction. As an application, we give a simplified proof of a theorem of Hofer-Viterbo on the existence of closed characteristic leaves for certain contact type hypersufaces in cotangent bundles.

  • The performance of ETFs on developed and emerging markets with consideration of regional diversity
    • Krystian Zawadzki
    2020 Pełny tekst Quantitative Finance and Economics

    This study evaluates the performance of Exchange-Traded Funds (ETFs) by using various tracking error calculation approaches. The aim of the paper is, on the one hand, an evaluation of the performance of ETFs relative to their benchmarking indexes and, on the other, an endeavour to specify any relationship between this performance and both geographical location and the degree of market development. The research was conducted on the basis of 18 different ETFs issued by iShares, six for each of three regions: both Americas, Asia and Europe. The sole criterion for ETF’s selection was the benchmark. All data were collected with daily frequency. They range from January 2013 to December 2019. The results indicate that ETFs do not mimic their corresponding indexes well. Calculated tracking errors do not equal zero and are often significantly negative. Furthermore, the value of tracking errors depends on the region and the degree of market development.

  • The Possibilities of Improving the Fatigue Durabilityof the Ship Propeller Shaft by Burnishing Process
    • Stefan Dzionk
    • Włodzimierz Przybylski
    • Bogdan Ścibiorski
    2020 Pełny tekst Machines

    Heavily loaded structural elements operating in a corrosive environment are usuallyquickly destroyed. An example of such an element is a ship propeller operating in a seawaterenvironment. This research presents a fatigue resistance test performed on elements operating inseawater. Different processing parameters applied on the samples in particular were compared withthe specimens whose surface had been burnished differently and they were compared to specimenswith a grinded surface. The research shows that the structural elements whose surface has beenburnished can have up to 30% higher fatigue strength in a seawater environment than the elementswhose surface has been grinded. During burnishing, an important feature of the process is the degreeof cold rolling of the material. The resistance of the component to fatigue loads increases only to acertain level with increasing the degree of the cold rolling. Further increasing the degree of coldrolling reduces the fatigue strength. Introducing additional stresses in the components (e.g., assemblystresses) reduces the fatigue strength of this component in operation and these additional stressesshould be accounted for while planning the degree of the cold rolling value. A device that allowsfor simultaneous turning and shaft burnishing with high slenderness is presented in the appendixof this article. This device can be connected to the computerized numerical control system andexecuted automatic process according to the machining program; this solution reduces the number ofoperations and cost in the process

  • The Potential of Improving Air Quality by Urban Mobility Management: Policy Guidelines and a Case Study
    • Joanna Badach
    2020 Pełny tekst IOP Conference Series: Earth and Environmental Science

    There is a growing recognition among planners and policy makers that proper transformation of urban mobility systems is crucial to the reduction of air pollution emission. The main objective of the work was to review the current urban mobility strategies in the city of Gdańsk, Poland in terms of their potential for the improvement of urban air quality. Firstly, general policy guidelines for mobility systems were formulated based on a review of recent relevant studies and existing solutions from various European and Asian cities. Then the main spatial characteristics of the transport system and mobility patterns in Gdańsk were determined and visualised by means of GIS-based tools, supported by the analysis of local urban and environmental planning documents. The current air quality status in Gdańsk was also described. Subsequently, the policies proposed in two documents for the urban mobility management in Gdańsk were identified and cross-compared with the previously reviewed solutions from other cities in terms of air quality improvement. The results showed that the strategies for air pollution mitigation are not integrated with the process of urban planning in Gdańsk to a sufficient degree. Finally, some recommendations were also suggested to improve the current strategies.

  • The power of personal brand authenticity and identification: top celebrity players’ contribution to loyalty toward football
    • Wioleta Kucharska
    • Ilenia Confente
    • Federico Brunetti
    2020 Pełny tekst Journal of Product & Brand Management

    Purpose: In the current era of fake news, illusions, manipulations, and other artificial attributes of virtuality and reality, authenticity is a virtue that people highly appreciate. This study examines the influence of the personal brand authenticity of top football players on loyalty to the football discipline in general, via the mediation of personal brand identification. Design: Based on data collected from a convenience sample of 562 respondents from Poland via an electronic survey and analyzed using the structural equation modeling method this study explored, first, the influence of top football players’ personal brand authenticity on consumers’ identification with these football players, and second, how this identification may lead to enhancing loyalty to the football discipline. Finally, it verified how the loyalty effect (attitudinal and behavioral) varies across different categories of spectators. Originality: This study presents evidence that the personal authenticity of football celebrities to measure loyalty to the football discipline in general, as mediated by personal brand identification. Moreover, this study proves that the loyalty to football driven by the personal brand authenticity of football stars differs between spectators’ categories, and it differs from the loyalty driven by clubs. Findings: Personal brand identification with authentic football stars is a focal factor enabling the creation of loyalty (attitudinal and behavioral) to the whole discipline. Consumers’ perceptions of the authenticity of the personal brands of football players play a role in increasing identification with these personal brands. This identification is essential in achieving loyalty to football as a sports discipline via football celebrities. Implications: Football players perceived as authentic are evaluated more positively, leading to consumer identification with these players, which, in turn, increases consumers’ loyalty to football. Thus, the presence of authentic, skilled players is important for football, but the actual loyalty effect from authenticity can be achieved only by identification. Therefore, football 3 requires exceptional, strong stars who reflect a set of desired personal values. Further research is needed to identify the desired set of values that leads to identification with football stars.

  • The preparation and evaluation of core-shell magnetic dummy-template molecularly imprinted polymers for preliminary recognition of the low-mass polybrominated diphenyl ethers from aqueous solutions
    • Mariusz Marć
    • Piotr Paweł Wieczorek
    2020 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT

    The design, preparation process, binding abilities, morphological characteristic and prospective field of application of dummy-template magnetic molecularly imprinted polymer (DMMIP) for preliminary recognition of the selected low-mass polybrominated diphenyl ethers (PBDE-47 and PBDE-99) from aquatic environment were investigated. The surface of iron oxide (Fe3O4) nanopowder (50-100 nm particles size) was modified with tetraethoxysilane and next prepared Fe3O4@SiO2 particles were dispersed in anhydrous toluene functionalized by (3-aminopropyl)triethoxysilane. Finally, MIPs' thin film layer on the surface of Fe3O4@SiO2@NH2 was formed in acetonitrile as a solvent solution, using ethylene glycol dimethacrylate as the cross-linker, building monomer, 1,1′-Azobis(cyclohexanecarbonitrile) as the radical initiator, methacrylic acid as a functional monomer and 4,4'- Dihydroxydiphenyl ether as the dummy template molecule as a structural analogue of low-mass PBDEs. To characterize the chemical structure of prepared DMMIPs, the Fourier transform infrared spectroscopy analysis was performed. The specific surface area of the developed sorbent was estimated using Brauner-Emmet-Teller nitrogen adsorption/desorption analysis. To assess the average pore sizes, pore diameters and pore volumes of the prepared sorbent, the Barret-Joyner-Halenda technique was applied. The average values of imprinting factor for PBDE-47 and PBDE-99 were 11.3 ± 1.6 and 13.7 ± 1.2, respectively. The average value of recovery of PBDE-47 and PBDE-99 for developed DMMIPs from modelling water : methanol solution were 85.4 ± 6.7% and 86.4 ± 9.4%, respectively. In a case of spiked distilled water, tap water as well as local river water the calculated recovery values ranged from 65%% up to 82% and from 33% up to 76% for PBDE-47 and PBDE-99, respectively. Following the preliminary research on selected water samples, the proposed combination of imprinting technology and core–shell materials with magnetic properties might be considered as a promising sorption tool used for targeted recognition of low-mass PBDEs in aquatic solutions.

  • The Product of Matrix Metalloproteinase Cleavage of Doxorubicin Conjugate for Anticancer Drug Delivery: Calorimetric, Spectroscopic, and Molecular Dynamics Studies on Peptide–Doxorubicin Binding to DNA
    • Kamila Butowska
    • Krzysztof Żamojć
    • Mateusz Kogut
    • Witold Kozak
    • Dariusz Wyrzykowski
    • Wiesław Wiczk
    • Jacek Czub
    • Jacek Piosik
    • Janusz Rak
    2020 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Matrix metalloproteinases (MMPs) are extracellular matrix degradation factors, promoting cancer progression. Hence, they could provide an enzyme-assisted delivery of doxorubicin (DOX) in cancer treatment. In the current study, the intercalation process of DOX and tetrapeptide-DOX, the product of the MMPs' cleavage of carrier-linked DOX, into dsDNA was investigated using stationary and time-resolved fluorescence spectroscopy, UV-Vis spectrophotometry and isothermal titration calorimetry (ITC). The molecular dynamics (MD) simulations on the same tetrapeptide-DOX…DNA and DOX…DNA systems were also performed. The undertaken studies indicate that DOX and tetrapeptide-DOX can effectively bond with dsDNA through the intercalation mode; however, tetrapeptide-DOX forms less stable complexes than free DOX. Moreover, the obtained results demonstrate that the differences in DNA affinity of both forms of DOX can be attributed to different intercalation modes. Tetrapeptide-DOX shows a preference to intercalate into DNA through the major groove, whereas DOX does it through the minor one. In summary, we can conclude that the tetrapeptide-DOX intercalation to DNA is significant and that even the lack of non-specific proteases releasing DOX from the tetrapeptide conjugate, the presence of which is suggested by the literature for the efficient release of DOX, should not prevent the cytostatic action of the anthracycline.

  • The Proposition of an Automated Honing Cell with Advanced Monitoring
    • Adam Barylski
    • Piotr Sender
    2020 Pełny tekst Machines

    Honing of holes allows for small shape deviation and a low value of a roughness profile parameter, e.g., Ra parameter. The honing process heats the workpiece and raises its temperature. The increase in temperature causes thermal deformations of the honed holes. The article proposes the construction of a honing cell, containing in addition to CNC honing machine: thermographic camera, sound intensity meter, and software for collecting and analyzing data received during machining. It was proposed that the level of sound intensity obtained during honing could be monitored continuously and that the images from a thermographic camera could be analyzed on-line. These analyses would be aimed at supervising honing along with the on-line correction of machining parameters. In addition to the oil cooler, the machining cell may have an automatic selection of the grain trajectory shape, with specified value of the radii of curvature of the abrasive grain trajectories, according to the wall thickness of the honed workpiece, which will result in reducing the temperature generated during honing. Automated honing cell can mostly increase honing process efficiency. Simulations in FlexSim showed the possibility of increasing the efficiency of the honing process more than 20 times.

  • The pulsed laser ablation synthesis of colloidal iron oxide nanoparticles for the enhancement of TiO2 nanotubes photo-activity
    • Piotr Kupracz
    • Emerson Coy
    • Katarzyna Grochowska
    • Jakub Karczewski
    • Jakub Rysz
    • Katarzyna Siuzdak
    2020 APPLIED SURFACE SCIENCE

    The rapid, only a few minutes long synthesis of FeO, Fe3O4, and Fe2O3nanoparticles mixture utilizing the pulsedlaser ablation using simply pure iron target and water was demonstrated. The size and crystal phase of Fe-basedNPs were characterized using DLS and HR-TEM techniques, respectively. The metastable suspension of FeO,Fe3O4, and Fe2O3nanoparticles was used to the decoration of anodized TiO2nanotubes (TiO2-NTs) by means ofthe ultrasonic bath. SEM inspection confirms preservation of the ordered morphology even upon 60 min longexposition to the ultrasounds whereas TOF SIMS indicated penetration of iron species down to the TiO2-NTsbase. Finally, the electrochemical investigation of decorated and bare TiO2-NTs has shown a response typical forFe2+/Fe3+iron species and the boosted activity towards oxygen evolution reaction in the anodic regime. As ofhigh importance, for the 30 min long ultrasound-assisted modification, the photocurrent was enhanced almost2.5 times comparing to the pristine material exposed to the solar light, although differences in optical propertieswere negligible. Taking into account outstanding activity namely response upon irradiation and effectiveness ofwater splitting, the proposed approach can be regarded as a facile one generating much less waste in comparisonto typical wet-chemistry methods.

  • The Quantum Efficiency Roll-Off Effect in Near-Infrared Organic Electroluminescent Devices with Iridium Complexes Emitters
    • Wojciech Mróz
    • Sagar Kesarkar
    • Alberto Bossi
    • Daniel Pelczarski
    • Piotr Grygiel
    • Waldemar Stampor
    2020 Pełny tekst Materials

    The electroluminescence quantum efficiency roll-off in iridium(III)-based complexes, namely Ir(iqbt)2(dpm) and Ir(iqbt)3(iqbt=1 (benzo[b]thiophen-2-yl)-isoquinolinate, dpm=2,2,6,6-tetramethyl-3,5-heptanedionate) utilized as near-infrared emitters in organic light emitting diodes with remarkable external quantum efficiencies, up to circa 3%, 1.5% and 1%, are measured and analyzed. With a 5–6 weight % of emitters embedded in a host matrix, the double-layer solution-processed structure as well as analogous three-layer one extended by a hole-conducting film are investigated. The triplet-polaron, the Onsager electron-hole pair dissociation and the triplet-triplet annihilation approaches were used to reproduce the experimental data. The mutual annihilation of triplets in iridium emitters was identified as prevailingly controlling the moderate roll-off,with the interaction between those of iridium emitters and host matrixes found as being less probable. Following the fitting procedure, the relevant rate constant was estimated to be(0.5−12)×10−12cm3/s,values considered to be rather too high for disordered organic systems, which was assigned to the simplicity of the applied model. A coexistence of some other mechanisms is therefore inferred, ones, however, with a less significant contribution to the overall emission quenching.

  • The Quaternization Reaction of 5-O-Sulfonates of Methyl 2,3-o-Isopropylidene-β-D-Ribofuranoside with Selected Heterocyclic and Aliphatic Amines
    • Barbara Dmochowska
    • Rafał Ślusarz
    • Jarosław Chojnacki
    • Justyna Samaszko-Fiertek
    • Janusz Madaj
    2020 Pełny tekst MOLECULES

    The synthesis of N-((methyl 5-deoxy-2,3-O-isopropylidene-β-D-ribofuranoside)-5-yl) ammonium salts are presented. To determine the effect of the nucleophile type and outgoing group on the quaternization reaction, selected aliphatic and heterocyclic aromatic amines reacted with: methyl 2,3-O-isopropylidene-5-O-tosyl-β-D-ribofuranoside or methyl 2,3-O-isopropylidene-5-O-mesyl-β-D -ribofuranoside or methyl 2,3-O-isopropylidene-5-O-triflyl-β-D-ribofuranoside were performed on a microscale. High-resolution 1H- and13C-NMR spectral data for all new compounds were recorded. Additionally, the single-crystal X-ray diffraction analysis for methyl 2,3-O-isopropylidene-5-O-mesyl-β-D-ribofuranoside and selected in silico interaction models are reported

  • The Reactivity of Phosphanylphosphinidene Complexes of Transition Metals Toward Terminal Dihaloalkanes
    • Anna Ordyszewska
    • Natalia Szynkiewicz
    • Jarosław Chojnacki
    • Jerzy Pikies
    • Rafał Grubba
    2020 Pełny tekst INORGANIC CHEMISTRY

    The reactivities of phosphanylphosphinidene complexes [(DippN)2W(Cl)(η2-P−PtBu2)]− (1), [(pTol3P)2Pt(η2- P=PtBu2)] (2), and [(dppe)Pt(η2-P=PtBu2)] (3) toward dihaloalkanes and methyl iodide were investigated. The reactions of the anionic tungsten complex (1) with stochiometric Br(CH2)nBr (n = 3, 4, 6) led to the formation of neutral complexes with a tBu2PP(CH2)3Br ligand or neutral dinuclear complexes with unusual tetradentate tBu2PP(CH2)nPPtBu2 ligands (n = 4, 6). The methylation of platinum complexes 2 and 3 with MeI yielded neutral or cationic complexes bearing side-on coordinated tBu2P−P-Me moieties. The reaction of 2 with I(CH2)2I gave a platinum complex with a tBu2P-P-I ligand. When the same dihaloalkane was reacted with 3, the P-P bond in the phosphanylphosphinidene ligand was cleaved to yield tBu2PI, phosphorus polymers, [(dppe)PtI2] and C2H4. Furthermore, the reaction of 3 with Br(CH2)2Br yielded dinuclear complex bearing a tetraphosphorus tBu2PPPPtBu2 ligand in the coordination sphere of the platinum. The molecular structures of the isolated products were established in the solid state and in solution by single-crystal X-ray diffraction and NMR spectroscopy. DFT studies indicated that the polyphosphorus ligands in the obtained complexes possess structures similar to free phosphenium cations tBu2P+=P−R (R = Me, I) or (tBu2P+=P)2.

  • The reduction of auxiliaries power demand: The challenge for electromobility in public transportation
    • Mikołaj Bartłomiejczyk
    • Robert Kołacz
    2020 Pełny tekst JOURNAL OF CLEANER PRODUCTION

    An important role in the consumption of electric energy in urban transport are non-traction needs (auxiliaries), the main part of which is heating and air condition (HVAC). Auxiliaries are responsible for almost half of total energy consumption (normal weather conditions) and in the winter (or hot summer) it reaches up to 70% in daily scale. The reduction of energy used for non-traction needs is currently the main challenge related to the reduction of energy demand of means of transport. It is particularly important for battery vehicles, powered from an energy source with a very limited capacity. The article presents the analysis of the influence of air temperature on the energy consumption of electric traction carried out on the basis of the real data measurement analysis. The relation between the ambient temperature and the demand for heating power was determined quantitatively. The impact of traffic delays on auxiliaries energy consumption was analyzed and it was shown, that traffic congestion can result in 60% overall energy consumption increase. Presented researches also refer to the relationship between the bus charging cycle (night charging, opportunity fast charging) and the optimal value of energy consumption, which should be assumed for energy calculations. Depending on the charging mode, the differences can reach up to 50%. In the final part of the article, different methods of optimization of non-traction needs systems were compared.

  • The resistance of S235JR steel to cavitation erosion
    • Alicja Krella
    • Dominika Zakrzewska
    • Artur Marchewicz
    2020 WEAR

    The erosion resistance of S235JR steel to flow cavitation was investigated. In order to understand an influence of steel properties and cavitation intensities on the degradation mechanisms, low-carbon S235JR steel was tested in the as-received state and after thermal treatment (annealing) under four different flow velocities. Annealing decreased steel hardness, which made S235JR steel less resistant to cavitation erosion. The performed investigations showed that the state of this steel affects the degradation process, e.g. erosion rate and development of surface roughness. An increase in flow velocity caused a linear increase in erosion rate of S235JR steel in as-received state, and an exponential increase in erosion rate of S235JR steel after thermal treatment. Regardless of the state of S235JR steel, an increase in the flow velocity caused a logarithmic increase in the area with increased roughness for Ra > 0.5 μm, where Ra parameter is the arithmetic average of all profile deviations from the mean line over the evaluation length. The increase in surface roughness and the Ra parameter depended on the flow velocity. However, for high flow rates, the Rp parameter, which is the mean of the five maximum profile peak heights from the mean line over the evaluation length, represented an effect of micro-jets impacts on the surface development better than the Ra parameter. A new parameter P, which combines elongation, impact energy and hardness, has been proposed. With increased value of this parameter, the resistance to cavitation erosion decreases. The performed investigations showed that the volume loss can be described by equation in the form of ΔV = C(t)∙(v-v0)n(t), where the function C(t) describes the development of cracks in the surface layer and the function n(t) describes the development of the hardened surface layer.

  • The Role of Electrostatics in Enzymes: Do Biomolecular Force Fields Reflect Protein Electric Fields?
    • Richard Bradshaw
    • Jacek Dziedzic
    • Chris-Kriton Skylaris
    • Jonathan Essex
    2020 Pełny tekst Journal of Chemical Information and Modeling

    Preorganization of large, directionally oriented, electric fields inside protein active sites has been proposed as a crucial contributor to catalytic mechanism in many enzymes, and it may be efficiently investigated at the atomistic level with molecular dynamics simulations. Here, we evaluate the ability of the AMOEBA polarizable force field, as well as the additive Amber ff14SB and Charmm C36m models, to describe the electric fields present inside the active site of the peptidyl-prolyl isomerase cyclophilin A. We compare the molecular mechanical electric fields to those calculated with a fully first-principles quantum mechanical (QM) representation of the protein, solvent, and ions, and find that AMOEBA consistently shows far greater correlation with the QM electric fields than either of the additive force fields tested. Catalytically relevant fields calculated with AMOEBA were typically smaller than those observed with additive potentials, but were generally consistent with an electrostatically driven mechanism for catalysis. Our results highlight the accuracy and the potential advantages of using polarizable force fields in systems where accurate electrostatics may be crucial for providing mechanistic insights.

  • The role of hydrogen bonding on tuning hard-soft segments in bio-based thermoplastic poly(ether-urethane)s
    • Paulina Kasprzyk
    • Hynek Beneš
    • Ricardo Keitel Donato
    • Janusz Datta
    2020 Pełny tekst JOURNAL OF CLEANER PRODUCTION

    This work describes the preparation of bio-based thermoplastic poly(ether-urethane)s (TPU) via a prepolymer method and investigates the effect of varying the interphase hydrogen-bonding (H-bonding) on physicochemical, thermal and mechanical properties. This was achieved by varying the glycol type and molar ratio of [NCO]/[OH] groups used during the prepolymer chain extending step. The TPUs’ chemical structure was analyzed by Fourier Transform Infrared Spectroscopy (FTIR-ATR) spectroscopy, the H-bonding fraction and crystallinity were examined by FTIR, Different Scanning Calorimetry (DSC), X-ray diffraction (XRD) and Polarized light optical microscopy (POM), and their processability was surveyed using the melt-flow index and Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF-MS). Moreover, a coupled- Thermogravimetric analysis (TGA)-FTIR method provided useful information about thermal degradation and low molecular mass volatile products formed during the TPUs’ thermal decomposition. Altogether, this study intends to provide engineers with new insights to obtain environmentally friendly TPU-based polymeric components (from prime materials to process methods), by associating the application of bio-based reactants to the TPU synthesis and understanding the conditions for these bio-TPUs been applied in low-waste processes such as additive manufacturing.

  • The role of numerical tests in assessing road restraint system functionality
    • Marcin Budzyński
    • Kazimierz Jamroz
    • Krzysztof Wilde
    • Wojciech Witkowski
    • Łukasz Jeliński
    • Dawid Bruski
    2020 Pełny tekst European Transport Research Review

    Key to understanding the needs and building road infrastructure management tools to prevent and mitigate run-off-road accidents is to identify hazards and their sources which are a result of wrong design, construction, and installation of road restraint systems. Building such tools requires advanced studies with field tests, simulations and models to demonstrate the effects of selected parameters on road user safety. The research work included building numerical models which were validated with crash tests and mathematical models to assess the effects of selected parameters on the safety and functionality of devices. Twenty five field tests were the basis for conducting 670 numerical tests. Preliminary results of numerical tests are also presented looking at selected problems such as barriers on curves, presence of kerbs and obstacles within barrier working width. The methodology will help with an optimal selection of parameters leading to improved safety as regards errant vehicles.

  • The role of robotisation in improving bakery product quality
    • Radosław Drozd
    2020 Aparatura Badawcza i Dydaktyczna

    The article aims to present the role of robotisation in increasing bakery product quality, as it is closely linked to machine reliability, as well as hygienic and sanitary conditions. All machines employed in the production process ought to be maintained at full production potential and reliability, which also has a fundamental influence on the final product’s quality. While participating in the 2014-2020 Smart Growth Operational Programme in a bakery, the author isolated factors influencing bakery product quality within the context of production line robotisation. He grouped the factors into three categories present within the production process, i.e., related to raw materials, technological processes, and organisational-technical aspects.

  • The role of traditional architectural models in the first stages of education.
    • Agnieszka Szuta
    • Antoni Taraszkiewicz
    2020 Pełny tekst World Transactions on Engineering and Technology Education

    The oldest architectural models discovered by scientists date from the Middle Ages, while models or 1:1 scale prototypes were used in ancient times. Architectural miniatures quickly evolved into an indispensable tool for designers that enabled them to creatively express their thoughts and ideas. Mock-ups became a way of helping a designer communicate a concept, and their educational value was also recognised. The method of modelling, as with the field of architecture itself, has developed over the centuries. Nowadays, traditional physical models are being replaced by virtual ones. The question arises: can traditional mock-ups be replaced completely by virtual models? The purpose of this article was to examine the present role in education of traditional, physical architectural models. The research was supported by experience gained, involving manual work and spatial games, from Architectural Design 1 in the Faculty of Architecture at Gdańsk University of Technology (FA-GUT). Are virtual models, which undoubtedly have many advantages, a good alternative to the physical ones?

  • The role of water in deep eutectic solvent-base extraction
    • Mária Vilková
    • Justyna Płotka-Wasylka
    • Vasil Andruch
    2020 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS

    Deep eutectic solvents (DESs) are currently being used in different sectors, such as electrochemistry, electrodeposition, organic synthesis, nanoparticle preparation, bioactive compound separation, etc. Their use in analytical chemistry has only recently begun to expand. Despite the publication of a sufficient number of DES-based analytical extraction procedures, some details, such as interaction of DESwith the sample and target analytes aswell as withwater are insufficiently explored and theoretically explained.Herewe discuss the role ofwater in DES-based extraction in terms of analytical chemistry, especially for the pre-treatment of solid samples.We believe that this reviewwill benefit those who have linked their researchwith DESs andwill enable themto speed up theirwork.

  • The Selection of Anchoring System for Floating Houses by Means of AHP Method
    • Emilia Miszewska
    • Maciej Niedostatkiewicz
    • Radosław Wiśniewski
    2020 Pełny tekst Buildings

    This paper indicates and analyses the use of anchoring systems, such as mooring piles, booms, mooring cables, and deadweight anchors with additional elastic connectors, which are the most frequently applied by the producers of floating houses. The selection of the most advantageous anchoring system is complicated and requires the application of quantitative and qualitative data and methods. This publication presents the results of the calculations using one of the most common methods of multi-criteria analysis of decision-making, namely AHP (analytic hierarchy process). The anchoring system, which is the most beneficial for users, has been indicated with the use of the main criteria such as: cost, time, external risk factors, geospatial factors, and the sub-criteria of the first and second order. Due to the conducted analysis, it has been shown that the most significant factor of the anchoring system selection for the users of floating houses is the investment cost that needs to be borne during the usage, and the most favourable anchoring system is the use of mooring cables.

  • The state of the art in the field of decrease the pollution in the South Baltic area
    • Hubert Byliński
    • Małgorzata Szopińska
    • Aneta Łuczkiewicz
    • Sylwia Fudala-Książek
    2020

    Various form of human activity such as maritime transports, industrial activities, busy traffic, intensive farming and animal husbandry can have negative impact on natural marine environment. Baltic Sea catchment area is characterized by the high river water flux and wastewater treatment plants discharges. Additionally, the limited shallow connection to the North Sea results in little water exchange and residence time of approximately 35 years. Thus, some hazardous substances, which accumulate in the marine can be toxic to organisms and they can cause a health risk for people. Some of them may be hazardous due to their persistence and bio-accumulating properties.

  • The Structure of Entrepreneurial Team Members’ Competencies: Between Effectuation and Causation
    • Katarzyna Stankiewicz
    • Michał Tomczak
    • Paweł Ziemiański
    • Beata Krawczyk-Bryłka
    2020 Pełny tekst Education Sciences

    A conscious shaping of entrepreneurial competence is a relevant element of entrepreneurial education. In order to recognize which of the competencies regarded as entrepreneurial are characteristic of members of entrepreneurial teams, which is crucial for the work of those teams, it is necessary to identify the structure of those competencies. This quantitative study was conducted with the use of a survey method and involved 111 entrepreneurs working within 48 entrepreneurial teams. The main objective of the research was to verify the compliance of entrepreneurial competence with the eectual vs. causal approach, which would allow us to answer the question regarding which of these approaches characterizes entrepreneurs to a greater extent. This study aimed to examine which entrepreneurial competencies characterize entrepreneurs working in entrepreneurial teams, to verify them with the eectual vs. causal approach, and to define their internal structure. The results of this research revealed that the competencies related to the eectual approach are indicated to more frequently and strongly characterize the surveyed entrepreneurs. Additionally, an exploratory factor analysis enabled the identification of three main, internally consistent groups of elements forming the competence structure of the surveyed entrepreneurs. Our results may be used n the development and modernization of curricula and courses in entrepreneurship education.

  • The Substantial Improvement of Amphotericin B Selective Toxicity Upon Modification of Mycosamine with Bulky Substituents
    • Edward Borowski
    • Natalia Salewska
    • Joanna Boros-Majewska
    • Marcin Serocki
    • Izabela Chabowska
    • Maria Milewska
    • Dominik Ziętkowski
    • Sławomir Milewski
    2020 Medicinal Chemistry

    Abstract: Background: It is assumed that the unfavorable selective toxicity of an antifungal drug Amphotericin B (AmB) can be improved upon chemical modification of the antibiotic molecule. Objective: The aim of this study was verification of the hypothesis that introduction of bulky substituents at the amino sugar moiety of the antibiotic may result in diminishment of mammalian vitro toxicity of thus prepared AmB derivatives. Methods: Twenty-eight derivatives of AmB were obtained upon chemical modification of amino group of mycosamine residue. This set comprised 10 N-succinimidyl-, 4 N-benzyl-, 5 Nthioureidyl- and 9 N-aminoacyl derivatives. Parameters characterizing biological in vitro activity of novel compounds were determined. Results: All the novel compounds demonstrated lower than AmB antifungal in vitro activity but most of them exhibited negligible cytotoxicity against human erythrocytes and three mammalian cell lines. In consequence, the selective toxicity of majority of novel antifungals, reflected by the selective toxicity index (STI = EH50/IC50) was improved in comparison with that of AmB, especially in the case of 5 compounds. The novel AmB derivatives with the highest STI, induced substantial potassium efflux from Candida albicans cells at concentrations slightly lower than IC50s but did not trigger potassium release from human erythrocytes at concentrations lower than 100 μg/mL. Conclusion: Some of the novel AmB derivatives can be considered promising antifungal drug candidates.

  • The Synergistic Microbiological Effects of Industrial Produced Packaging Polyethylene Films Incorporated with Zinc Nanoparticles
    • Szymon Mania
    • Mateusz Cieślik
    • Marcin Konzorski
    • Paweł Święcikowski
    • Andrzej Nelson
    • Adrianna Banach
    • Robert Tylingo
    2020 Pełny tekst Polymers

    Zinc compounds in polyolefin films regulate the transmission of UV-VIS radiation, affect mechanical properties and antimicrobial activity. According to hypothesis, the use of zinc- containing masterbatches in polyethylene films (PE) with different chemical nature—hydrophilic zinc oxide (ZO) and hydrophobic zinc stearate (ZS)—can cause a synergistic effect, especially due to their antimicrobial properties. PE films obtained on an industrial scale containing zinc oxide and zinc stearate masterbatches were evaluated for antimicrobial activity against E. coli and S. aureus strains. The morphology of the samples (SEM), composition (EDX), UV barrier and transparency, mechanical properties and global migration level were also determined. SEM micrographs confirmed the good dispersion of zinc additives in the PE matrix. The use of both masterbatches in one material caused a synergistic effect of antimicrobial activity against both bacterial strains. The ZO masterbatch reduced the transparency of films, increased their UV-barrier ability and improved tensile strength, while the ZS masterbatch did not significantly change the tested parameters. The global migration limit was not exceeded for any of the samples. The use of ZO and ZS masterbatch mixtures enables the design of packaging with high microbiological protection with a controlled transmission for UV and VIS radiation.

  • The Undisrupted Growth of the Airbnb Phenomenon between 2014–2020. The Touristification of European Cities before the COVID-19 Outbreak
    • Łukasz Bugalski
    2020 Pełny tekst Sustainability

    As a result of the Airbnb eruption, not only has the character of the short-term rental market been completely transformed, but the decades long growth in tourism has also been further accelerated. Therefore, due to the new demands of the tourism economy, the major shift in the usage of historic city centers occurred–the process of ‘touristification’, that results in the emergence of its new, unsustainable form. Despite the significance of those circumstances, there is a lack of any broader quantitative research that would present the dynamic of the Airbnb phenomenon. Therefore, thanks to the recognition of AirDNA data, such statistical analysis has become possible. The goal of this paper is to investigate the Airbnb’s growth trajectories—data that bind together a market dimension of the growth in tourism and the community aspect of an urban change caused by its impact—from the perspective of its spatial distribution across Europe between 2014 and 2020. As a result, it was possible to follow the Airbnb phenomenon during its undisrupted period of growth—from its sudden eruption, further spread, and potential future after the COVID-19 outbreak—all together with its logarithmic character, concentration form, and momentum of already reached economic equilibrium.

  • THE UNSUSTAINABILITY OF PUBLIC-SECTOR ORGANIZATIONAL NETWORKS: A CASE STUDY OF VOLUNTARY COURT NETWORKS
    • Przemysław Banasik
    • Sylwia Morawska
    • Monika Odlanicka-Poczobutt
    2020 Pełny tekst Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

    Purpose: The purpose of this study is to identify the problem of sustainability of public-sector 12 organizational networks on the example of common courts and what it implies for further 13 research. Methodology: The study used qualitative research tools in the form of structured 14 interviews. Interviews were conducted with 36 presidents and directors of common courts. 15 After conducting and transcribing each interview, their content was analyzed to capture data 16 related to network durability. Based on the proposed methodology, 5 elements of network 17 sustainability were distinguished: goal continuity, reliability, communication, network 18 capability, fairness. 19 Findings: It was found that the judiciary has the potential to take advantage of network 20 cooperation mechanisms, which may involve different relationships and interactions. However, 21 after the pilot project, voluntary court networks formed during the implementation of the project 22 gradually dissolved, ceased to exist. The identification of the elements of network was 23 an additional outcome of the analysis of the results of a pilot study PWP Edukacja w dziedzinie 24 zarządzania czasem i kosztami postępowań – case management. 25 Originality/value: Research on the networking of public organizations, and in particular 26 common courts, is still a cognitive gap. The results of research carried out for the purposes of 27 the article are trying to fill this gap. within the study, the causes of failures in maintaining 28 network relationships in common orchards were identified.

  • The Use of Organic Coagulants in the Primary Precipitation Process at Wastewater Treatment Plants
    • Krzysztof Czerwionka
    • Anna Wilińska
    • Agnieszka Tuszyńska
    2020 Pełny tekst Water

    Measurements for determining the effect of chemically enhanced primary treatment (CEPT) on the efficiency of pollutant removal from wastewater were carried out using conventional inorganic coagulants PIX113 with polymer A110 (Kemipol, Police, Poland) and unconventional cationic organic coagulants Cofloc (Attana, Coalville, UK) C29510 (Kemipol, Police, Poland) and Sedifloc 575 (3F Chimica, Sandrigo, Italy). The average removal efficiency in the 2-h sedimentation process was 46%, 34%, 8%, 12% for the total suspended solids, organic matter (COD), total nitrogen, and total phosphorus, respectively. The use of organic coagulants contributed to 14–81% increase of pollutant removal efficiency. Substantial discrepancies in biological nutrient removal processes were not discovered in two-phase (anaerobic-anoxic) experiments without and with the addition of the organic coagulants. The increase in organic matter removal efficiency as a result of the CEPT process may contribute to a 65–80% increase in biogas production. The conducted research confirms the possibility of using organic coagulants in the primary precipitation process in wastewater treatment plants (WWTPs) in accordance with the principles of maximum energy recovery, thereby promoting renewable energy sources. Additionally, organic coagulants, as opposed to inorganic ones, do not cause a significant increase of chloride and sulfate ion concentrations, which facilitates the use of treated wastewater in the water reuse systems, such as irrigation of agricultural crops.

  • The use of recycled semiconductor material in crystalline silicon photovoltaic modules production - A life cycle assessment of environmental impacts
    • Ewa Klugmann-Radziemska
    • Anna Kuczyńska-Łażewska
    2020 Pełny tekst SOLAR ENERGY MATERIALS AND SOLAR CELLS

    To offset the negative impact of photovoltaic modules on the environment, it is necessary to introduce a longterm strategy that includes a complete lifecycle assessment of all system components from the production phase through installation and operation to disposal. Recycling of waste products and worn-out systems is an important element of this strategy. As the conclusions from the previous studies have shown, thermal treatment provides an efficient first step in the recycling process, while chemical treatment was more advantageous in the second step. This study aims to assess the environmental impact of recovering and recycling the valuable semiconductor silicon wafer material from photovoltaic solar cells. A comparison was made between producing new solar cells with or without recycled silicon material. The analysis of the photovoltaic cell life cycle scenario including material recycling presented in this article was performed using SimaPro software and data combined and extended from different LCI databases. The idea is that the use of recycled materials, which were energy-consuming in the primary production stage, allows to meaningly reduce the energy input in the secondary life cycle. All stages of the silicon cell life cycle contribute to the Global Warming Potential (GWP) and greenhouse gas emissions reductions through the use of recycled silicon material represented 42%. The total environmental impact of photovoltaic production can be reduced by as much as 58%, mainly through reduced energy consumption in the production process of high purity crystalline silicon.

  • The Use of USV to Develop Navigational and Bathymetric Charts of Yacht Ports on the Example of National Sailing Centre in Gdańsk
    • Mariusz Specht
    • Cezary Specht
    • Maciej Szafran
    • Artur Makar
    • Paweł Dąbrowski
    • Henryk Lasota
    • Piotr Cywiński
    2020 Pełny tekst Remote Sensing

    Apart from extensive infrastructure protection, modern yacht ports should primarily provide vessels with navigational safety associated with their maneuvering on the approach fairway, as well as mooring in the port aquatory. For this reason, yachts entering the harbor should have up-to-date, accurate, and reliable charts of the port and its surroundings. This article presents hydrographic surveys conducted in the National Sailing Centre (NSC) yacht port at the Gdańsk University of Physical Education and Sport (GUPES), whose aim was to define and develop unique bathymetric and navigational charts of the harbor and the approach fairway. These can be used for example to manage berths in the marina or inform about the depths in the yacht port and on the approach fairway. The chart of the NSC-GUPES and its approach fairway is Poland’s first cartographic image of a harbor, performed entirely on the basis of surveys conducted by an Unmanned Surface Vehicle (USV). The study results demonstrated that the use of a small-sized USV in bathymetric measurements of yacht ports and marinas was significantly more effective than the traditional (manned) hydrographic surveys. Such vessels allow measurements to be carried out in hard-to-reach locations, even between mooring vessels, and in the immediate vicinity of quays. Thanks to the implemented automatic mode of steering on sounding profiles, USVs are equally efficient and capable of carrying out hydrographic surveys on a larger waterbody, i.e., the approach fairway.

  • Theoretical and Actual Feed Per Tooth During Wood Sawing on an Optimizing Cross-Cut Saw
    • Kazimierz Orłowski
    • Wojciech Blacharski
    • Daniel Chuchała
    • Przemysław Dudek
    2020 Pełny tekst

    The work presents the geometries of circular saw teeth, whose task is to divide the cross-cut of the cutting layer. For efficient machining on a cross-cut saw with high feed speed values (about 1 ms−1) maximal theoretical feeds per tooth are determined. These values were compared with the actual values determined during transverse cutting of pine wood on a special test stands in industrial conditions. In the experiment the rotational speed of the main driving motor and the feed speed of the saw blade were simultaneously measured. Unique experimental results revealed that the feed driving system with the crank mechanism driven with the rotary servo motor only the phenomenon of the decrease in the spindle rotational speed was present, which caused a slight increase of the feed per tooth. In the case of the pneumatic actuator applied in the feeding driving system its flexibility together with larger changes in feed speed additionally were observed. For that reason in a new cross-cut saw for the feeding system driven by the crank mechanism with the rotary servo motor ought to be recommended.

  • Theoretical and Economic Evaluation of Low-Cost Deep Eutectic Solvents for Effective Biogas Upgrading to Bio-Methane
    • Edyta Słupek
    • Patrycja Makoś
    • Jacek Gębicki
    2020 Pełny tekst ENERGIES

    This paper presents the theoretical screening of 23 low-cost deep eutectic solvents (DESs) as absorbents for effective removal of the main impurities from biogas streams using a conductor-like screening model for real solvents (COSMO-RS). Based on thermodynamic parameters, i.e., the activity coefficient, excess enthalpy, and Henry’s constant, two DESs composed of choline chloride: urea in a 1:2 molar ratio (ChCl:U 1:2), and choline chloride: oxalic acid in a 1:2 molar ratio (ChCl:OA 1:2) were selected as the most effective absorbents. The σ-profile and σ-potential were used in order to explain the mechanism of the absorptive removal of CO2, H2S, and siloxanes from a biogas stream. In addition, an economic analysis was prepared to demonstrate the competitiveness of new DESs in the sorbents market. The unit cost of 1 m3 of pure bio-methane was estimated to be in the range of 0.35–0.37 EUR, which is comparable to currently used technologies.

  • Theoretical and Experimental Studies on the Visible Light Activity of TiO2 Modified with Halide-Based Ionic Liquids
    • Marta Paszkiewicz-Gawron
    • Samanta Makurat
    • Janusz Rak
    • Magdalena Zdrowowicz
    • Wojciech Lisowski
    • Adriana Zaleska-Medynska
    • Kowalska Ewa
    • Paweł Mazierski
    • Justyna Łuczak
    2020 Pełny tekst Catalysts

    Formation of a surface complex between organic molecules and TiO2 is one of the possible strategies for the development of visible light-induced TiO2 photoactivity. Herein, three ionic liquids (ILs) with the same cation and dierent anions (1-butylpirydynium chloride/bromide/iodide) have been applied for the surface modification of TiO2 and to understand the role of anions in visible light-induced activity of ILs-TiO2 systems. Photocatalytic screening tests (the measurements of phenol photodegradation reaction rate) revealed that anion type aected visible light activity ( > 420 nm) of TiO2 obtained by the ILs-assisted solvothermal method. Density functional theory (DFT) calculations demonstrated that interactions between halogen anions and oxygen vacancies (OV) on the surface of the TiO2 particles could be responsible for the specific wavelength-induced excitation and finally for the observed photoactivity of titania under visible light. Finally, our theoretical calculations have been proven by experiments using monochromatic light (the apparent quantum eciency was measured) and the properties of obtained samples were characterized using scanning electron microscopy (SEM), X-ray powder

  • Theoretical and experimental study on scattering of low-energy electrons by dimethyl and diethyl ethers
    • Gillian Tatreau
    • Borna Hlousek
    • Mateusz Zawadzki
    • Murtadha Khakoo
    • Fernanda P Bardela
    • Alessandra Souza Barbosa
    • Márcio H F Bettega
    2020 JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS

    We report a joint theoretical and experimental investigation on low-energy electron scattering by dimethyl and diethyl ethers. The experimental elastic differential cross sections were measured at impact energies from 1 eV up to 30 eV and scattering angle range of 10◦ to 130◦. Theoretical elastic differential, integral and momentum-transfer cross sections are calculated at impact energies up to 30 eV, employing the Schwinger multichannel method implemented with norm-conserving pseudopotentials, in the static-exchange and static-exchange plus polarization approximations. Our experimental and theoretical results for dimethyl and diethyl ether are compared with previous data for their isomers, ethanol and butanol, respectively. These comparisons reveal that although the cross sections for the ether and its respective alcohol present similar magnitudes, the angular behavior of their differential cross sections shows some significant differences. From the analysis of the integral cross sections for electron scattering by dimethyl and diethyl ether, we observe a broad structure, at around 9.5 eV, which we assign as the overlap of several resonant structures.

  • Therapeutic Potential of Carnosine and Its Derivatives in the Treatment of Human Diseases
    • Klaudia Chmielewska
    • Krystyna Dzierzbicka
    • Iwona Inkielewicz-Stępniak
    • Maja Przybyłowska
    2020 Pełny tekst CHEMICAL RESEARCH IN TOXICOLOGY

    Despite significant progress in the pathogenesis, diagnosis, treatment, and prevention of cancer and neurodegenerative diseases, their occurrence and mortality are still high around theworld. The resistance of cancer cells to the drugs remains a significant problem in oncology today,while in the case of neuro-degenerative diseases, therapies reversing the process are still yet to be found. Furthermore, it is important to seek new chemotherapeutics reversing side effects of currently used drugs or helping them perform their function to inhibit progression of the disease. Carnosine, a dipeptide constisting of β-alanine and L-histidine, has a variety of functions to mention: antioxidant, antiglycation, and reducing the toxicity of metal ions. It has therefore been proposed to act as a therapeutic agent for many pathological states. The aim of this paper was to find if carnosine and its derivatives can be helpful in treating various diseases. Literature search presented in this review includes review and original papers found in SciFinder, PubMed, and Google Scholar. Searches were based on substantial keywords concerning therapeutic usage of carnosine and its derivatives in several diseases including neurodegenerative disorders and cancer. In this paper, we review articles and find that carnosine and its derivatives are potential therapeutic agents in many diseases including cancer, neurodegenerative diseases, diabetes, and schizophrenia. Carnosine and its derivatives can be used in treating neurodegenerative diseases, cancer, diabetes, or schizophrenia, although their usage is limited. Therefore, there’s an urge to synthesize and analyze new substances,vercoming the limitation of carnosine itself.

  • Thermal Biomass Conversion: A Review
    • Witold Lewandowski
    • Michał Ryms
    • Wojciech Kosakowski
    2020 Pełny tekst Processes

    In this paper, the most important methods of thermal conversion of biomass, such as: hydrothermal carbonization (180–250 °C), torrefaction (200–300 °C), slow pyrolysis (carbonization) (300–450 °C), fast pyrolysis (500–800 °C), gasification (800–1000 °C), supercritical steam gasification, high temperature steam gasification (>1000 °C) and combustion, were gathered, compared and ranked according to increasing temperature. A comprehensive model of thermal conversion as a function of temperature, pressure and heating rate of biomass has been provided. For the most important, basic process, which is pyrolysis, five mechanisms of thermal decomposition kinetics of its components (lignin, cellulose, hemicellulose) were presented. The most important apparatuses and implementing devices have been provided for all biomass conversion methods excluding combustion. The process of combustion, which is energy recycling, was omitted in this review of biomass thermal conversion methods for two reasons. Firstly, the range of knowledge on combustion is too extensive and there is not enough space in this study to fully discuss it. Secondly, the authors believe that combustion is not an environmentally-friendly method of waste biomass utilization, and, in the case of valuable biomass, it is downright harmful. Chemical compounds contained in biomass, such as biochar, oils and gases, should be recovered and reused instead of being simply burnt—this way, non-renewable fuel consumption can be reduced.

  • Thermal failure of a second rotor stage in heavy duty gas turbine
    • Daniel Sławiński
    • Paweł Ziółkowski
    • Janusz Badur
    2020 Pełny tekst ENGINEERING FAILURE ANALYSIS

    The impulse mode of operation and the supply of various types of fuels causes frequent failures even in the heavy duty gas turbines. The paper presents the ravages of second rotor stage failure in a gas turbine. The excessive thermal elongation rise caused by fuel change was indicated as the main cause. We applied nonlinear numerical analysis, preceded by thermodynamic calculations of the turbine and visual inspection of the effects of failure. Simulations were performed on undamaged blade geometry under load resulting from combustion: nominal fuel and the changed fuel. Thermodynamic calculations demonstrated a 70 °C increase in temperature using the changed fuel. The blade tip displacements demonstrated the possibility of abrasion. The amount of displacement of the tip of the turbine blade with increasing pressure or increasing rotational speed do not pose as great a threat, as does the increase in the temperature. To maintain long-term and safe operation of a gas turbine, it is necessary to strictly observe the manufacturer's guidelines regarding fuel composition. If during the operation of a gas turbine it is likely that it can be powered by various types of fuels, then the structure should have adequate effort reserves and working tolerances.

  • Thermal Images Analysis Methods using Deep Learning Techniques for the Needs of Remote Medical Diagnostics
    • Alicja Kwaśniewska
    2020 Pełny tekst

    Remote medical diagnostic solutions have recently gained more importance due to global demographic shifts and play a key role in evaluation of health status during epidemic. Contactless estimation of vital signs with image processing techniques is especially important since it allows for obtaining health status without the use of additional sensors. Thermography enables us to reveal additional details, imperceptible in images acquired with standard visible light cameras, yet, low resolution is its significant limitation. In the presented doctoral dissertation, original artificial intelligence solutions were proposed based on performed analysis of innovative thermal image processing methods using Deep Learning techniques for the needs of remote medical diagnostics. Possibility of modifying architecture of deep neural network designed for classification of visible light images in such a way that distribution of extracted features will be recreated enabling detection of facial areas from low resolution thermal data was verified in conducted experiments. Effectiveness of the proposed deep neural network architecture was demonstrated in practical applications, increasing resolution of thermal images and leading to better image quality metrics in comparison to stateof-the-art convolutional models, as well as increasing accuracy of facial areas detection, contactless estimation of respiratory rate and person recognition.

  • Thermally tuneable optical and electrochemical properties of Au-Cu nanomosaic formed over the host titanium dimples
    • Wiktoria Lipińska
    • Katarzyna Grochowska
    • Jakub Karczewski
    • Jacek Ryl
    • Adam Cenian
    • Siuzdak Katarzyna
    2020 Pełny tekst CHEMICAL ENGINEERING JOURNAL

    Au-Cu nanostructures offer unique optical and catalytic properties unlike the monometallic ones resulting from the specific interaction. Among others, they have the ability to exhibit surface plasmon resonance, electrochemical activity towards the oxygen and hydrogen evolution reaction (OER, HER) as well as improved photoresponse in relation to monometalic but those properties depend highly on the substrate where bimetallic structures are immobilized. In this work, bimetallic gold-copper mosaics over the conducting structured titanium substrate were fabricated via following steps: anodization of Ti foil, chemical etching of as-formed titania resulting in nanodimpled Ti substrate (TiND), sputtering of thin metal layer (Au, Cu) in various sequences, and finally thermal treatment in furnace at 450°C or 600°C. The morphology, optical and structural properties were investigated in details and it was shown that both arrangements of metallic films and thermal conditions strongly affect the morphology and optical features. The XPS results confirmed the presence of gold-copper alloys and copper oxide species. Last but not least, the electrochemical activities were verified in 0.1 M NaOH using cyclic voltammetry and linear voltammetry measurements performed in dark and under visible light illumination. Among all investigated materials in both anodic and cathodic regimes bimetallic 5Au/5Cu sample annealed at 450°C exhibits the highest response towards OER and HER, respectively. This is further boosted by the light with λ>420 nm. Upon exposure to visible light, the current density for 5Au/5Cu and 5Cu/5Au electrodes reached 1.32 mA cm-2 and 1.26 mA cm-2, respectively, while in the case of monometallic structures the current was below 10 μA cm-2. Both optical and electrochemical behaviour indicate a strong synergistic effect arising within the bimetallic mosaic formed over the TiND.

  • Thermal-Resistant Polyurethane/Nanoclay Powder Coatings: Degradation Kinetics Study
    • Maryam Jouyandeh
    • Behzad Hadavand
    • Farimah Tikhani
    • Reza Khalili
    • Babak Bagheri
    • Payam Zarrintaj
    • Krzysztof Formela
    • Henri Vahabi
    • Mohammad Saeb
    2020 Pełny tekst Coatings

    In the present study, thermal degradation kinetics of polyurethane (PU) powder coatings reinforced with organo-modified montmorillonite (OMMT) was investigated. PU nanocomposites were prepared in different concentrations of 1, 3, and 5 wt.% of OMMT via the extrusion method. The microstructure of the nanocomposites was observed by scanning electron microscope (SEM) illustrating uniform dispersion of OMMT nano-clay platelets in the PU matrix except for the sample containing 5 wt.% nano-palates. Thermal degradation kinetics of the PU nanocomposite was investigated using thermogravimetric analysis (TGA) at different heating rates of 5, 10, and 20 °C/min. The results showed that the initial decomposition temperatures were shifted toward higher values (more than 40 °C for T5% and up to 20 °C for T10%) by introducing the nano-clay to the PU matrix. Friedman, Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO), and modified Coats-Redfern iso-conversional methods were applied to model the decomposition reaction and the activation energy of the nanocomposite powder coatings. Overall, the presence of nano-clay increased the activation energy of the PU degradation up to 45 kJ/mol, when compared to the blank PU, which suggests very high thermal stability of nanocomposites. The Sestak-Berggren approach proposed a good approximation for the reaction model, especially at low temperatures. Thus, PU decomposition was detected as an autocatalytic reaction, which was suppressed by the barrier effect of OMMT nano-palates intercalated with polymer chains.

  • Thermochemical Conversion of Biomass and Municipal Waste into Useful Energy Using Advanced HiTAG/HiTSG Technology
    • Jan Stąsiek
    • Marek Szkodo
    2020 Pełny tekst ENERGIES

    An advanced thermal conversion system involving high-temperature gasification of biomass and municipal waste into biofuel, syngas or hydrogen-rich gas is presented in this paper. The decomposition of solid biomass and wastes by gasification is carried out experimentally with a modern and innovative regenerator and updraft continuous gasifier, among others. A ceramic high-cycle regenerator provides extra energy for the thermal conversion of biomass or any other solids waste. Highly preheated air and steam gas (heated up to 1600 C) was used as an oxidizing or gasification agent (feed gas). Preheated feed gas also enhances the thermal decomposition of the gasification solids for fuel gas. However, the main objective of this work is to promote new and advanced technology for the thermochemical conversion of biomass for alternative energy production. Selected results from experimental and numerical studies are also presented.

  • Thermodynamic study of binary mixtures of toluene with ionic liquids, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and 1-butylpyridinium bis(trifluoromethylsulfonyl)imide
    • Dorota Warmińska
    • Iwona Cichowska-Kopczyńska
    2020 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS

    Densities, refractive indices and viscosities at 293.15, 298.15, 303.15, 308.15 and 313.15 K of binary mixtures of toluene with 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and 1-butylpyridinium bis(trifluoromethylsulfonyl)imide have been measured over the miscible region at p = 0.1 MPa. From the experimental data, values of excess molar volume, excess thermal expansion, deviation in refractive index, deviation in viscosity and excess Gibbs energy of activation for viscous flow have been calculated. These properties have been fitted to the Redlich-Kister-type polynomial equation in order to analyse non-ideal behaviour of the studied mixtures. Moreover, partial and apparent molar volumes of toluene and ionic liquid in their binary systems have been calculated. Finally, the effects of temperature and cation of ionic liquid on the physicochemical properties were analysed and discussed in terms of intermolecular interactions occurring in the studied systems.

  • Thermohydraulic maldistribution reduction in mini heat exchangers
    • Paweł Dąbrowski
    2020 Pełny tekst APPLIED THERMAL ENGINEERING

    A detailed numerical investigation has been carried out to analyze the flow maldistribution in 50 parallel 1 mm × 1 mm rectangular minichannels and 1 mm depth minigap section with rectangular, trapezoidal, triangular or concave manifolds in Z-type flow configuration. The working medium was ethanol and the mass flow rate was 5 × 10−4 kg/s. Both sections were heated from the bottom side. Heat flux of 10 000 W/m2 and 5000 W/m2 was applied to the minichannel and minigap section respectively. The method of the flow maldistribution mitigation in the diabatic flow has been checked. Thanks to introducing a threshold, the maldistribution coefficient can be reduced about twice in the minigap section or three times in the minichannel section with the 0.5 mm threshold as compared to the conventional arrangement. The velocity profile and temperature profile over the heat exchanger’s surface have been analyzed. Reduction of the maldistribution results in lower maximum temperature over the surface. The distribution is more uniform in the minichannel section than in the minigap section. This is due to a two-dimensional flow over a minigap. Hence, a two-dimensional approach to define maldistribution coefficients in minigap sections, which has not been distinguished in literature yet was used.

  • Thermophysical study of the binary mixtures of triethyl phosphate with N-methylformamide, N,N-dimethylformamide and N,N-dimethylacetamide – Experimental and theoretical approach
    • Dorota Warmińska
    • Maciej Śmiechowski
    2020 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS

    Densities at (293.15, 298.15, 303.15 and 308.15) K, and viscosities and ultrasonic velocities at 298.15 K of binary liquid mixtures of triethyl phosphate with N-methylformamide, N,N-dimethylformamide and N,N-dimethylacetamide have been measured over the entire range of composition at p = 0.1 MPa. From the experimental data, values of excess molar volume, excess isentropic compressibility, viscosity deviation and excess Gibbs energy of activation for viscous flow have been calculated. These results were fitted to the Redlich-Kister-type polynomial equation. The viscosity deviations and the excess Gibbs energy were found to be positive for the all systems investigated, while the excess volumes and the excess isentropic compressibilities were negative for TEP + DMA and for TEP + DMF systems, and positive for mixtures TEP + NMF. These results were interpreted based on the strength of the specific interaction, size and shape of molecules. Molecular dynamics simulations were used to provide a detailed explanation of the differences between the TEP + NMF and other systems, which were ultimately traced to strong hydrogen bonding between NMF and TEP.

  • Thickness accuracy of sash gang sawing
    • Kazimierz Orłowski
    • Jakub Sandak
    • Daniel Chuchała
    2020 Pełny tekst BIORESOURCES

    Thin lamellae, corresponding to the layer components of structural glued members, i.e. 2-ply or 3-ply glued parquet, can be manufactured in re-sawing operations of kiln-dried wood blocks. These must be prepared with high dimensional accuracy and adequate surface quality following specific technical requirements for lamellae thickness variations, especially in the upper layers of the glued composite parquet. The accuracy of oak lamellae thickness was examined here for a re-sawing process performed on the sash gang saw. A series of cutting tests were carried out in sawmill production conditions. The overall objective for these observations was to determine an effect of both the cumulative time of sawing (progress of the tool wear) and the lamella position (distribution of lateral forces) on the dimensional accuracy of production. Lamellae size control was conducted following the Brown methodology. Detailed within-board, between-board, and total sawing standard deviations for the examined lamellae positions in the gang were determined. The obtained results revealed that outermost lamellae are more subjected to dimensional inaccuracy than lamellae from the centre of the sawn block or frieze

  • Three-dimensional printed trachea helps to design tailored treatment for tracheobronchomalacia
    • Robert Dziedzic
    • Gustaw Rzyman
    • Witold Rzyman
    2020 Pełny tekst Polish Archives of Internal Medicine

    Tracheobronchomalacia is a rare respiratory disease that is manifesting by impaired ventilation with expiratory collapse of the tracheal wall due to softening of the supporting cartilage and hypotonia of myoelastic elements [1]. Surgery is the mainstay of treatment. We report the case of 39 -year old man with exacerbation of chronic respiratory distress. The membranous wall of the trachea and the large bronchi was stretched to such an extent that the tracheal lumen was almost completely closed during the exhalation phase, and the cartilage bent in the opposite direction taking the opposite C-shape. To plan the operation in detail, we used 3D printing. We made the airway model in 3d using the GE AW-suite software. Then the model was printed on a 3d printer in plastic. The tracheobronchoplasty through right posterolateral thoracotomy was performed. A polipropylen mesh was sewn into the membranous wall of the trachea and main bronchi. A satisfactory wallresult was obtained. 3D printed trachea was very helpful in the planning of the operational strategy.

  • Tight bounds on global edge and complete alliances in trees
    • Kacper Wereszko
    • Robert Kozakiewicz
    • Robert Lewoń
    • Michał Małafiejski
    2020

    In the talk the authors present some tight upper bounds on global edge alliance number and global complete alliance number of trees. Moreover, we present our NP-completeness results from [8] for global edge alliances and global complete alliances on subcubic bipartite graphs without pendant vertices. We discuss also polynomial time exact algorithms for finding the minimum global edge alliance on trees [7] and complete alliance on trees [8].

  • TIM
    • Luciano Segreto
    2020

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