2018 - Repozytorium publikacji - Politechnika Gdańska

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Publikacje z roku 2018

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Structure-property relationships in peroxide-assisted blends of poly(ε-caprolactone) and poly(3-hydroxybutyrate)
- Marta Przybysz-Romatowska
- Łukasz Zedler
- Mohammad Saeb
- Krzysztof Formela
2018 REACTIVE & FUNCTIONAL POLYMERS
Poly(ε-caprolactone) and poly(3-hydroxybutyrate) (PCL/PHB) blends in two weight ratios (75/25 and 50/50) were reactively compatibilized in the presence of di-(2-tert-butyl-peroxyisopropyl)-benzene and dicumyl peroxide as free radical initiators. Rheological, mechanical, thermal properties and morphological features, as well as the chemical structure of PCL/PHB blends were investigated. It was found that regardless of PCL/PHB blend ratio, the viscosity of reactively compatibilized blends increased, approximately 4-fold for dicumyl peroxide and 7-fold for di-(2-tert-butyl-peroxyisopropyl)-benzene, which confirmed their partial branching/cross-linking. The results showed that studied peroxides are effective compatibilizers for PCL/PHB (75/25) blends. However, di-(tert-butylperoxyisopropyl)benzene peroxide was more efficient and its application in PCL/PHB (75/25) blends resulted in significant increase of the tensile yield strength and elongation at break of 38% and 144%, respectively. On the other hand, the compatibilization effects of peroxides on tensile properties of PCL/PHB (50/50) blends were negligible. This is due to free-radical induced degradation of PHB and formulation of low molecular weight compounds. These degradation products can act as plasticizers and reduce the interfacial tension in the phase boundary, which corresponded to changes in morphology and chemical structure of studied PCL/PHB blends.
Structure-rheology relationship of fully bio-based linear polyester polyols for polyurethanes - Synthesis and investigation
- Paulina Parcheta
- Janusz Datta
2018 Pełny tekst POLYMER TESTING
The synthesis of polyols from renewable substances as an alternative for petrochemical-based polyols play important matter in the polyurethane industry. In this work, the fully bio-based linear polyester polyols with different catalyst amounts were synthesized via two-step polycondensation method. The effect of various catalyst content on the structure and rheological behavior were established. Fourier Transform Infrared Spectroscopy, Nuclear Magnetic Resonance, Gel Permeation Chromatography and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry allowed confirming the impact of the catalyst amount during synthesis on the molecular structure of the resulted polyols. Through the hyphenation of these sophisticated polymer characterization techniques, information on the molecular weight distribution was obtained. Moreover, it was found that the obtained polyols are non-Newtonian fluids. According to conducted measurements, it was observed that the poly(propylene succinate)s prepared with the use of the 0.25 wt.% and 0.30 wt.% catalyst revealed the structures and selected properties the most akin to design.
Student Perspectives on the 2017 ESA Concurrent Engineering Challenge
- Kelsey Doerksen
- Thomas van‘t Klooster
- William Ferguson
- Sean Pepper
- Darian van Paridon
- Renato Amorim
- Rohan Chotalal
- Katarzyna Ciechowska
- Adam Dąbrowski
- Verena Kunbrger
- Jakub Porębski
- Schwinning Marius
- Yuchen Shang
- Maxime Valençon
2018 Pełny tekst
In September 2017, the first ESA Academy’s Concurrent Engineering Challenge (CEC) was held, giving 88 Master’s and PhD-level students from twelve ESA Member and Associate States a powerful platform to experience system engineering in an intense, fast paced, and real-world environment. Within four days, teams of physics and engineering students in Concurrent Design Facilities (CDF) located in Politecnico di Torino, Universidad Polit´ecnica de Madrid, University of Strathclyde and ESA’s European Space Security and Education Centre (ESEC) each developed a preliminary design for a satellite mission to map the Lunar south pole for water-ice as a precursor for the Moon village concept. Each team was divided into subsystem groups of two to three students each. As the subsystems design progressed, key parameters were regularly updated and shared within the team using ESA’s Open Concurrent Design Tool (OCDT). The Challenge concluded with final presentations and critical discussion of the four satellite designs. Lessons learned during CEC were carried back by the students to their respective universities and projects and are discussed by the ESEC student team. The remaining co-authors are listed in the Acknowledgements section of the paper.
Studies on novel BiyXz-TiO2/SrTiO3 composites: Surface properties and visible light-driven photoactivity
- Martyna Marchelek
- Ewelina Grabowska
- Tomasz Klimczuk
- Wojciech Lisowski
- Elio Giamello
- Adriana Zaleska-Medynska
2018 APPLIED SURFACE SCIENCE
A series of novel BiyXz-TiO2/SrTiO3 composites were prepared by multistep synthesis route. The asprepared photocatalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), Fourier transform infrared (FT-IR), Raman spectra and BET analysis. The photocatalytic activity test was performed in aqueous solution of phenol under the irradiation of visible light range ( ≥ 420 nm). Obtained results revealed that the BiOI TiO2/SrTiO3 sample exhibit the highest photocatalytic activity under visible irradiation (0.6 mol/dm3/min). Thus, it was demonstrated that modification of the TiO2/SrTiO3 microspheres by flowers-like structure made of bismuth oxyiodide resulted in enhancement of photocatalytic activity under visible light. The role of active species during the decomposition process of organic compound was investigated using different types of active species scavengers as well as electron paramagnetic resonance analysis (EPR). The study showed that in the BiOI TiO2/SrTiO3/Vis system the holes (h+) plays relevant role in phenol decomposition. Furthermore, the stability and recyclable properties of obtained BiOI TiO2/SrTiO3 sample were confirmed during three consecutive processes.
Studies on optical transmittance of boron-doped nanocrystalline diamond films
- Aleksandra Wieloszyńska
- Robert Bogdanowicz
2018 Pełny tekst Photonics Letters of Poland
Thickness is one of the most important parameters in many applications using thin layers. This article describes thickness determination of a boron-doped nanocrystalline diamond (NCD) grown on fused silica glass. A spectroscopic measurement system has been used. A high refractive index (2.3 at 550nm) was achieved for NCD films. The thickness of NCD samples has been determined from the transmission spectrum.
Studies on Silver Ions Releasing Processes and Mechanical Properties of Surface-Modified Titanium Alloy Implants
- Aleksandra Radtke
- Marlena Grodzicka
- Michalina Ehlert
- Tadeusz Muzioł
- Marek Szkodo
- Michał Bartmański
- Piotr Piszczek
2018 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Dispersed silver nanoparticles (AgNPs) on the surface of titanium alloy (Ti6Al4V) and titanium alloy modified by titania nanotube layer (Ti6Al4V/TNT) substrates were produced by the chemical vapor deposition method (CVD) using a novel precursor of the formula [Ag5(O2CC2F5)5(H2O)3]. The structure and volatile properties of this compound were determined using single crystal X-ray diffractometry, variable temperature IR spectrophotometry (VT IR), and electron inducted mass spectrometry (EI MS). The morphology and the structure of the produced Ti6Al4V/AgNPs and Ti6Al4V/TNT/AgNPs composites were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Moreover, measurements of hardness, Young’s modulus, adhesion, wettability, and surface free energy have been carried out. The ability to release silver ions from the surface of produced nanocomposite materials immersed in phosphate-buffered saline (PBS) solution has been estimated using inductively coupled plasma mass spectrometry (ICP-MS). The results of our studies proved the usefulness of the CVD method to enrich of the Ti6Al4V/TNT system with silver nanoparticles. Among the studied surface-modified titanium alloy implants, the better nano-mechanical properties were noticed for the Ti6Al4V/TNT/AgNPs composite in comparison to systems non-enriched by AgNPs. The location of silver nanoparticles inside of titania nanotubes caused their lowest release rate, which may indicate suitable properties on the above-mentioned type of the composite for the construction of implants with a long term antimicrobial activity.
Study Analysis of Transmission Efficiency in DAB+ Broadcasting System
- Przemysław Falkowski-Gilski
2018 Pełny tekst
DAB+ is a very innovative and universal multimedia broadcasting system. Thanks to its updated multimedia technologies and metadata options, digital radio keeps pace with changing consumer expectations and the impact of media convergence. Broadcasting analog and digital radio services does vary, concerning devices on both transmitting and receiving side, as well as content processing mechanisms. However, the biggest difference is the way of managing content from numerous service providers. The main difference between forming the analog and digital radio signal is the fact, that in case of digital DAB+ transmission signals from all service providers need to be grouped in the so-called ensemble before entering the transmitter. Of course, the number of content providers, as well as assigned bitrate, is limited by the regulator. In this work a new adaptive bitrate assignment and resource allocation method has been described. This allocation depends on various characteristics and quality requirements assigned to different radio programs, which depend on the type of provided services, in particular transmitting content in the form of audio and speech signals. In order to verify the proposed method, a simulator has been developed, as well as a demonstrator consisting of a transmitting and receiving side.
Study of the Anti-Staphylococcal Potential of Honeys Produced in Northern Poland
- Katarzyna Grecka
- Piotr Kuś
- Randy Worobo
- Piotr Szweda
2018 Pełny tekst MOLECULES
The antimicrobial activity of 144 samples of honeys including 95 products from apiaries located in Northern Poland was evaluated. The antibacterial activity of those natural products, their thermal stability, and activity in the presence of catalase was investigated by microdilution assays in titration plates. The MTT assay was performed for the determination of anti-biofilm activity. Spectrophotometric assays were used for the determination of antioxidant potential, total phenolic content, and ability to generate hydrogen peroxide. Some of the investigated honeys exhibited surprisingly high antimicrobial, especially anti-staphylococcal, potential, with Minimal Inhibitory Concentration (MIC) values of only 1.56% (v/v). Much higher resistance was observed in the case of staphylococci growing as biofilms. Lower concentrations of the product, up to 12.5% (v/v) stimulated its growth and effective eradication of biofilm required concentration of at least 25% (v/v). Hydrogen peroxide has been identified as a crucial contributor to the antimicrobial activity of honeys supplied by Polish beekeepers. However, some of the results suggest that phytochemicals, especially polyphenols, play an important role depending on botanical source (both positive, e.g., in the case of buckwheat honeys as well as negative, e.g., in the case of some rapeseed honeys) in their antimicrobial potential.
Study of the influence of thermal factors on the welding process of polyethylene gas pipelines,
- M.v. Panchuk
- L. S. Shlapak
- N. Theremko
- Marek Szkodo
- Wojciech Kiełczyński
- S. Kishka
2018 Journal of Hydrocarbon Power Enigneering
A one-dimensional calculation scheme is proposed with the help of which it is possible to determine and set the technological parameters with the accuracy to be realized in production conditions: the temperature of the heating element and the heating time, which allows maximum mechanization of the technological operations of polyethylene gas pipelines welding. The numerical value of the coefficient of temperature for polyethylene grade PE-80 is determined and it is found that the presence of molten polymer mass at the ends of pipes is an additional source of their heating and a significant factor in obtaining high quality and reliable welds.
Study of the NO2 sensing mechanism of PEDOT-RGO film using in situ Raman Spectroscopy
- Katarzyna Dunst
- Konrad Trzciński
- Błażej Scheibe
- Mirosław Sawczak
- Piotr Jasiński
2018 SENSORS AND ACTUATORS B-CHEMICAL
In this work, the mechanism of the NO2 reaction with PEDOT-RGO composite film has been investigated via in situ Raman spectroscopy. Reduced graphene oxide (RGO), poly(3,4-ethylenedioxytiophene)-reduced graphene oxide (PEDOT-RGO) and poly(3,4-ethylenedioxytiophene)/ClO4− (PEDOT/ClO4−) films were fabricated using an electrodeposition method and used as resistance sensors of gaseous nitrogen dioxide. The experimental results indicate that NO2 causes overoxidation of the PEDOT polymer (PEDOT/ClO4− film) which leads to resistance increase and irreversible response. In contrast, the PEDOT-RGO response in the presence of NO2 is reversible. During short NO2 exposure, PEDOT from the PEDOT-RGO composite does not react to the gas but the presence of RGO in the PEDOT-RGO composite does not affect the overoxidation potential. It was found that the nitrogen dioxide reacts more readily to reduced graphene oxide, thus RGO “protects” the polymer against the adverse overoxidation process.
Study of ultraviolet-visible fluorescence emission following resonant Auger decay of the 2p-1nl core-excited states of argon atoms
- Tomasz Wąsowicz
- Antti Kivimäki
- Matija Stupar
- Marcello Coreno
2018 JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA
We have studied the excitation and relaxation of Ar+ ions populated in resonant Auger decay from the Ar 2p−1nl core-excited states by using ultraviolet-visible fluorescence spectroscopy and photon-photon delayed coincidence technique. Fluorescence emission yields were measured in the photon energy range of 240-–255 eV for the 3s23p4(1D)5s(2D) → 3s23p4(1D)4p(2F) (393 nm) and 3s23p4(1D)4d(2F) → 3s23p4(1D)4p(2F) (335 nm) transitions as well as for the 380–500 nm wideband emission. Delayed coincidence photon decay curves for the cascade transitions of the 335/459 nm and 393/459 nm lines were measured at the four most intense Ar 2p core excitations and the coincidence yields for both studied cascade channels were obtained at these Ar 2p excitations.
Study on 19th-century cast iron columns from the former financial office building in Kwidzyn
- Michał Kwasek
- Aleksander Piwek
- Robert Jankowski
2018 Pełny tekst MATEC Web of Conferences
The article presents the results for cast iron columns used as floor supports in the former financial office building in Kwidzyn (Poland).The stocktaking drawings provided the general and detailed data about the 19th century designer’s decisions. During the research, architectural and structural analysis was carried out. The graphics were used as a starting material for preparing 3D calculation models. The FEM-based numerical simulations were conducted using ABAQUS software. It was shown that the selection of such a structural solution in the building allowed arranging the interior space in an innovative way. The results of the study prove the thesis put forward of a low application extent of the load-bearing capacity of cast iron column used.
Studying road restraint systems to develop new guidelines
- Marcin Budzyński
- Krzysztof Wilde
- Kazimierz Jamroz
- Jacek Chróścielewski
- Wojciech Witkowski
- Stanisław Burzyński
- Dawid Bruski
- Łukasz Jeliński
2018 Pełny tekst
The paper will present a proposed approach to such work along with preliminary results of numerical studies for selected problems using road safety devices such as safety barriers on horizontal curves, the effect of kerbs on bridges or the location of obstacles within the barrier’s working width. The paper will discuss assumptions to a methodology of numerical models, calculations and automated processing of data to help with assessing the functionality of the devices.The paper will outline the design of the method for selecting optimal road safety devices. This will be based on device selection factors, fieldwork, surveys and simulations. The models andprocedures used in the method will help to identify and link different sources of hazard when using road safety devices to tackle a specific event and will help to identify the weaknesses in the safe use of types of road safety devices. The method will take account of the effect of different factors on optimising device selection. They are: types of hazard sources, road class and its parameters, road traffic parameters (volume, structure, speed). The method will be further developed in new research.
Studying the Behaviour of Pedestrians and Drivers Within Pedestrian Crossings
- Marcin Budzyński
- Kazimierz Jamroz
- Łukasz Jeliński
- Mariusz Kieć
2018
Every third road accident in Poland involves a pedestrian as a participant or, most of the time, a casualty. Pedestrian accidents are usually the result of complex situations and the outcome of a number of factors related to driver and pedestrian behaviour and road infrastructure. Safety depends largely on how well the traffic condition is perceived and on visibility in traffic. The re-lations between pedestrians and motorists and the resulting hazards should researched to ensure that pedestrians are provided with the right conditions for walking.
Suitability of LoRaWAN Technology for the Development of Maritime Applications
- Łukasz Wiszniewski
2018 TASK Quarterly
The LoRaWAN Technology opens new possibilities for gathering and analysis of distributed data. In the paper we concentrate on its maritime usability which was tested by us in the period from June to August 2018. Measurements of the LoRaWAN network coverage in the Bay of Gdansk area were carried out. Various conditions and places were tested. The research was planned in such a way as to gradually increase the range and control the impact of environmental factors. The results of the measurements confirm the wide application and a broad range of the technology. Combined with cloud computing it leads to new kinds of services and applications.
Sundials of St Mary’s Church in Gdańsk / Zegary słoneczne kościoła pw. Wniebowzięcia Najświętszej Panny Marii w Gdańsku
- Tomasz Tadeusz Jażdżewski
- Aleksander Piwek
2018 Pełny tekst Architectus
The paper presents contemporary research evidence of form, function and history of the sundials of St Mary’s Church in Gdańsk. The discussed sundials are located on the southern wall of the church transept. The sundial, which is believed to be made by Lorenzo Zachau in 1533, is placed on the west side of the western window, at the edge of the wall. The face of this sundial is separated by a horizontal line into two parts. The upper part is painted in stars and sun with metal bar (polos). The painting in the lower part has numbers and divisions denoting hours and halfhours. Researches, which have been conducted in connection to the conservational works allowed identifying irregular relics of plaster on the east side of this sundial and on the left side of the central window as relics of the second sundial. Outline of its face is marked by dents on the bricks. In the upper part a hole was found in which the polos was embedded. This sundial was located under the waterspout. Falling water caused its destruction, abandonment and foundation of the new sundial in a different place (near the edge of the wall). From these facts one can infer about the time of the foundation of this sundial. Probably it was made in the 2nd half of the 15th century as the first sundial in Gdańsk. Value of two sundials of St Mary church in Gdańsk arise from early origins and unique form.
Superconducting SrSnP with Strong Sn–P Antibonding Interaction: Is the Sn Atom Single or Mixed Valent?
- Xin Gui
- Zuzanna Sobczak
- Tay-Rong Chang
- Xitong Xu
- Angus Huang
- Shuang Jia
- Horng-Tay Jeng
- Tomasz Klimczuk
- Weiwei Xie
2018 CHEMISTRY OF MATERIALS
The large single crystals of SrSnP were prepared using Sn self-flux method. The superconductivity in the tetragonal SrSnP is observed with the critical temperature of ∼2.3 K. The results of a crystallographic analysis, superconducting characterization, and theoretical assessment of tetragonal SrSnP are presented. The SrSnP crystallizes in the CaGaN structure type with space group P4/nmm (S.G. 129, Pearson symbol tP6) according to the single-crystal X-ray diffraction characterization. A combination of magnetic susceptibility, resistivity, and heat capacity measurements confirms the bulk superconductivity with Tc = 2.3(1) K in SrSnP. According to the X-ray photoelectron spectroscopy measurement, the assignments of Sr2+ and P3– are consistent with the chemical valence electron balance principles. Moreover, it is highly likely that Sn atom has only one unusual oxidation state. First-principles calculations indicate the bands around Fermi level are hybridized among Sr d, Sn p, and P p orbitals. The strong Sn–P and Sr–P interactions pose as keys to stabilize the crystallographic structure and induce the superconductivity, respectively. The physics-based electronic and phononic calculations are consistent with the molecular viewpoint. After inclusion of the spin–orbit coupling into the calculation, the band degeneracies at Γ-point in the first Brillouin zone split into two bands, which yield to the van Hove singularities around Fermi level.
Superconductivity in the superhard boride WB4.2
- Elizabeth M. Carnicom
- Judyta Strychalska-Nowak
- Piotr Wiśniewski
- Dariusz Kaczorowski
- Weiwei Xie
- Tomasz Klimczuk
- R.j. Cava
2018 SUPERCONDUCTOR SCIENCE & TECHNOLOGY
We show that the superhard boride WB4.2 is a superconductor with a Tc of 2.05(5) K. Temperature-dependent magnetic susceptibility, electrical resistivity, and specific heat measurements were used to characterize the superconducting transition. The Sommerfeld constant γ for WB4.2 is 2.07(3) mJ mol−1 K−2 and the ΔC/γTc=1.56, which is somewhat higher than what is expected for weakly coupled Bardeen–Cooper–Schrieffer type superconductors. The Hc2 versus T plot is linear over a wide temperature range but does show signs of flattening by the lowest temperatures studied and therefore the zero temperature upper critical field (μ0Hc2(0)) for WB4.2 lies somewhere between the linear extrapolation of μ0Hc2(T) to 0 K and expectations based on the Werthamer–Helfand–Hohenberg model.
Support for Employees with ASD in the Workplace Using a Bluetooth Skin Resistance Sensor–A Preliminary Study
- Michał Tomasz Tomczak
- Marek Wójcikowski
- Paulina Listewnik
- Bogdan Pankiewicz
- Daria Majchrowicz
- Małgorzata Szczerska
2018 Pełny tekst SENSORS
The application of a Bluetooth skin resistance sensor in assisting people with Autism Spectrum Disorders (ASD), in their day-to-day work, is presented in this paper. The design and construction of the device are discussed. The authors have considered the best placement of the sensor, on the body, to gain the most accurate readings of user stress levels, under various conditions. Trial tests were performed on a group of sixteen people to verify the correct functioning of the device. Resistance levels were compared to those from the reference system. The placement of the sensor has also been determined, based on wearer convenience. With the Bluetooth Low Energy block, users can be notified immediately about their abnormal stress levels via a smartphone application. This can help people with ASD, and those who work with them, to facilitate stress control and make necessary adjustments to their work environment.
Support Product Development Framework by Means of Set of Experience Knowledge Structure (SOEKS) and Decisional DNA
- Edward Szczerbicki
- Muhammad Ahmed
- Cesar Sanin
2018
In this paper, we propose a framework to support product development activi-ties by utilizing Set of Experience Knowledge Structure (SOEKS) and Decisional DNA (DDNA). This idea will provide a new direction to researchers working on product development, especially designers and manufacturers. They will be working on the same platform and this will be reducing their communication gap. Once the final idea is perceived about product development, it will be easy to de-sign and manufacture it quickly and efficiently. Early consideration of manufac-turing issues can shorten product development cycle time, minimize overall de-velopment cost, and ensure a smooth transition into production. In the product development process, knowledge of previous products and processes is very im-portant as product development requires both knowledge and experience. This framework will store knowledge in the form of experiences of past decisions, and the system will update itself after every decision is taken.