2020 - Repozytorium publikacji - Politechnika Gdańska

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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.