2021 - Repozytorium publikacji - Politechnika Gdańska

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Copper Slag as a Potential Waste Filler for Polyethylene-Based Composites Manufacturing
- Aleksander Hejna
- Paulina Kosmela
- Mateusz Barczewski
- Olga Mysiukiewicz
- Adam Piasecki
2021 Pełny tekst Tanzania Journal of Science
The present study aimed to analyze the application of waste material from copper production– copper slag (ŻŻL) as filler for composites based on the high-density polyethylene (HDPE). Copper slag filler was introduced in the amounts of 1–20 wt%, and its influence on the appearance (color analysis), chemical structure (Fourier-transform infrared (FTIR) spectroscopy), microstructure (optical microscopy), as well as static (tensile tests) and dynamic (dynamical mechanical analysis (DMA)) mechanical properties of composites were investigated. Proper dispersion of filler implicated that the incorporation of up to 5 wt% of filler caused only slight, 5% drop of tensile strength, with the simultaneous 16% rise of Young’s modulus. Further increase of filler loading resulted in higher values of porosity and the rise of the adhesion factor, determined from DMA results, which led to the deterioration of mechanical performance. Moreover, spectroscopic analysis of PE-ŻŻL composites indicated that the analyzed filler might be applied as a coloring agent, and the appearance of composites may be engineered by adjustment of filler loading.
Copper(I) halide cluster-based coordination polymers modulated by chiral ditopic dithiodianthranilide ligands: synthesis, crystal structure and photoluminescence
- Jarosław Chojnacki
- Teresa Olszewska
- Tadeusz Połoński
- Michał Mońka
- Illia E. Serdiuk Serdiuk
- Piotr Bojarski
2021 CRYSTENGCOMM
Reaction of copper(I) halides with chiral dithiodianthranilidesmdtaandbdtaafforded polymeric complexeswhere polynuclear CuX clusters were linked together by ditopic bridging ligands into 1D chains or 2D layerstructures. In the case of racemic ligands double stranded chain polymers were formed where the Cu4X4(X = I or Br) cores are connected by enantiomeric pairs of the ditopic ligands. In contrast, a homochiralmdtaligand created a single stranded hybrid chain involving singlemdtaenantiomers and solvated Cu5I5clusters or 2D square (4,4) nets composed of rings comprising four Cu3X3clusters in nodes and fourhomochiral ligand molecules in sides with solvent MeCN molecules between the grid layers. The hybridlayer structure obtained from CuCl and the racemicmdtaligand crystallized as a conglomerate that led toits self-resolution into enantiomeric chiral crystals. The solid state CD spectra revealed contribution of twoelectronic transitions to the diffuse lowest energy absorption band of the complexes. In addition theobserved long wavelength Cotton effect sign reflected the helicity of the thiobenzamide chromophore inthe ligand unit. At room temperature the solid complexes exhibited weak red phosphorescence near 600–620 nm. Upon cooling down to 10 K all investigated complexes are phosphorescent with average lifetimesof 17–84μs.
Correlation between Fractal Dimension and Areal Surface Parameters for Fracture Analysis after Bending-Torsion Fatigue
- Wojciech Macek
2021 Pełny tekst Metals
This paper investigates the fracture surface topography of two steel and aluminum alloys subject to bending-torsion fatigue loadings, as well as their susceptibility to fatigue performance and failure mechanisms. Using fracture surface topography data analysis, elements with different geometries were elaborated. A correlation between the fractal dimension, other selected parameters of surface topography such as areal Sx, and fatigue loading conditions was found. Distinctions in particular regions of cracks were also recognized through proving the correctness and universality of the total fracture surface method. The influence of fatigue loading parameters on the surface to pography of fatigue fractures was demonstrated. For the analyzed cases, results show that the frac tal dimension and standard surface topography parameters represent a correlation between them and loading conditions. As a single parameter, the appropriate loading ratio cannot be outright calculated with fractal dimension, but can be estimated with some approximation, taking into ac count additional assumptions.
Corrosion Resistance and Surface Bioactivity of Ti6Al4V Alloy after Finish Turning under Ecological Cutting Conditions
- Kamil Leksycki
- Agnieszka Kaczmarek-Pawelska
- Kamil Ochał
- Andrzej Gradzik
- Danil Yurievich Pimenov
- Khaled Giasin
- Daniel Chuchała
- Szymon Wojciechowski
2021 Pełny tekst Materials
The influence of cooling conditions and surface topography after finish turning of Ti6Al4V titanium alloy on corrosion resistance and surface bioactivity was analyzed. The samples were machined under dry and minimum quantity lubrication (MQL) conditions to obtain different surface roughness. The surface topographies of the processed samples were assessed and measured using an optical profilometer. The produced samples were subjected to electrochemical impedance spectroscopy (EIS) and corrosion potential tests (Ecorr) in the presence of simulated body fluid (SBF). The surface bioactivity of the samples was assessed on the basis of images from scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analysis. The inspection of the surfaces of samples after turning under dry and MQL conditions revealed unevenly distributed precipitation of hydroxyapatite compounds (Ca/P) with a molar ratio in the range of 1.73–1.97. Regardless of the cutting conditions and surface roughness, the highest values of Ecorr ~0 mV were recorded on day 7 of immersion in the SBF solution. The impedance characteristics showed that, compared to the MQL conditions, surfaces machined under dry conditions were characterized by greater resistance and the presence of a passive layer on the processed surface. The main novelty of the paper is the study of the effect of ecological machining conditions, namely, dry and MQL cutting on the corrosion resistance and surface bioactivity of Ti6Al4V titanium alloy after finish turning. The obtained research results have practical significance. They can be used by engineers during the development of technological processes for medical devices made of Ti6Al4V alloy to obtain favorable functional properties of these devices.
Cost-Efficient EM-Driven Size Reduction of Antenna Structures by Multi-Fidelity Simulation Models
- Anna Pietrenko-Dąbrowska
- Sławomir Kozieł
2021 Pełny tekst Electronics
Design of antenna systems for emerging application areas such as the Internet of Things (IoT), fifth generation wireless communications (5G), or remote sensing, is a challenging endeavor. In addition to meeting stringent performance specifications concerning electrical and field properties, the structure has to maintain small physical dimensions. The latter normally requires searching for trade-off solutions because miniaturization has detrimental effects on antenna characteristics, in-cluding the impedance matching, gain, efficiency, or axial ratio bandwidth. Furthermore, explicit size reduction is more demanding than optimization with respect to other figures of merit. On the one hand, it is a constrained task with acceptance thresholds set on the bandwidth, gain, etc. On the other hand, optimum solutions are normally located at the boundary of the feasible region, traversing of which is a difficult problem by itself. The necessity of using full-wave electromagnet-ic (EM) analysis for antenna evaluation only aggravates the problem due to high computational costs associated with numerical optimization algorithms. This paper proposes a procedure for ex-pedited optimization-based miniaturization of antenna structures involving trust-region gradient search and multi-fidelity EM simulations, as well as implicit handling of design constraints using a penalty function approach. The assumed model management scheme is associated with the con-vergence status of the optimization process with the lowest fidelity model employed at the early stages of the algorithm run and the discretization density of the structure gradually increased to reach the high-fidelity level towards the end of the run. This allows us to achieve a considerable computational speedup without compromising the reliability. Our methodology is demonstrated using two broadband microstrip antennas. The obtained CPU savings exceed seventy percent as compared to the reference procedure involving high-fidelity model only.
Coupling between Blood Pressure and Subarachnoid Space Width Oscillations during Slow Breathing
- Agnieszka Gruszecka
- Magdalena Nuckowska
- Monika Waskow
- Jacek Kot
- Pawel Winklewski
- Wojciech Guminski
- Andrzej F. Frydrychowski
- Jerzy Wtorek
- Adam Bujnowski
- Piotr Lass
- Tomislav Stankovski
- Marcin Gruszecki
2021 Pełny tekst ENTROPY
The precise mechanisms connecting the cardiovascular system and the cerebrospinal fluid (CSF) are not well understood in detail. This paper investigates the couplings between the cardiac and respiratory components, as extracted from blood pressure (BP) signals and oscillations of the subarachnoid space width (SAS), collected during slow ventilation and ventilation against inspiration resistance. The experiment was performed on a group of 20 healthy volunteers (12 females and 8 males; BMI =22.1±3.2 kg/m2; age 25.3±7.9 years). We analysed the recorded signals with a wavelet transform. For the first time, a method based on dynamical Bayesian inference was used to detect the effective phase connectivity and the underlying coupling functions between the SAS and BP signals. There are several new findings. Slow breathing with or without resistance increases the strength of the coupling between the respiratory and cardiac components of both measured signals. We also observed increases in the strength of the coupling between the respiratory component of the BP and the cardiac component of the SAS and vice versa. Slow breathing synchronises the SAS oscillations, between the brain hemispheres. It also diminishes the similarity of the coupling between all analysed pairs of oscillators, while inspiratory resistance partially reverses this phenomenon. BP–SAS and SAS–BP interactions may reflect changes in the overall biomechanical characteristics of the brain.
Coupling transformation of carbon, nitrogen and sulfur in a long-term operated full-scale constructed wetland
- Jacek Mąkinia
- Wenbo Liu
- Md. Hasibur Rahaman
- Jun Zhai
2021 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT
The coupling transformation of carbon, nitrogen and sulfur compounds has been studied in lab-scale and pilot-scale constructed wetlands (CWs), but few studies investigated full-scale CW. In this study, we used batch experiments to investigate the potentials of carbon, nitrogen and sulfur transformation in a long-term operated, full-scale horizontal subsurface flow wetland. The sediments collected from the HSFW were incubated for 48h in the laboratory with supplying various dosages of carbon, nitrogen and sulfur compounds. The results showed that heterotrophic denitrification was the main pathway. At the same time, the sulfide(S2-)-based autotrophic denitrification was also present. Increasing TOC concentration or NO3- concentration could promote heterotrophic denitrification but did not inhibit the sulfide-based autotrophic denitrification. In our experiment, the highest NO3- removal via autotrophic denitrification was 25.23% while that via heterotrophic denitrification was 73.66%, leading to the total NO3- removal of 98.89%. The results also demonstrated that NO3- rather than NO2- was the preferable electron acceptor for both heterotrophic and sulfide-based autotrophic denitrification in the CW. Increasing S2- concentrations promote NO3- removal from 12.99% to 25.23% without organic carbon, but varying NO3- or NO2- has no effects. These results indicated that concentrations of S2-, instead of NO3- or NO2-, was the limiting factor for sulfide-based autotrophic denitrification in the studied CW. The microbial community analysis and correlation analysis between the transformation of carbon, nitrogen and sulfur compounds and relative abundance of bacteria further confirmed that in the CW, the key pathways coupling transformation were heterotrophic denitrification and sulfide-based autotrophic denitrification. Overall, the current study will enhance understanding of carbon, nitrogen, and sulfur transformation in CW and support better design and treatment efficiency.
Creating Polish space language dictionary - lessons learned
- Adam Dąbrowski
- Marek Moszyński
2021 Pełny tekst
Polish space industry suffers from lack of space vocabulary. Since joining European Space Agency in 2012, the sector has expanded rapidly now employing over 1000 specialists focusing mainly on space sustainability, space debris detection and tracking, robotics and propulsion systems. The Polish Space Agency together with The Polish Committee for Standardization have committed to creating the first lexicon of space language, along with definitions and even standards. Such tool will be used both in daily work of the industry as well as in teaching students and young professionals. This paper presents a unique challenge of creating a space wordbook from scratch with proper care for a language maintaining habits already established in the country. The task of the Polish Space Agency is to support the Polish space industry by combining the world of business and science. An important aspect of the Agency's activity is to promote the development of satellite technology that can be used in everyday life, including communication, navigation, environmental monitoring and weather forecasting. The Polish Committee for Standardization (Polski Komitet Normalizacyjny – PKN) is a national standards body responsible for the organization of standardization activities. The PKN is not a government agency, but a body governed by public law.
Creating Shared Value by the University
- Elżbieta Karwowska
2021 Social Responsibility Journal
Purpose Works that link creating shared value (CSV) with the university are arising, and there is a hope for a great future of this combination. The main problem with these works is that they are based on the wrong assumptions of what CSV is. The aim of the paper is to properly explain the concept of CSV and match it with university social responsibility (USR) at a strategic level. Design/methodology/approach A literature review on CSV and USR is briefly outlined. Then, at the foundation of existing models of the USR, normative model that integrates CSV at a strategic level is proposed. To validate the model and explain its assumptions, a qualitative study on Polish universities was conducted. Furthermore, a piece of recommendation for implementing CSV is presented. Findings Signs of CSV at universities have been observed. The trend may have positive implications, as it is similar to the recommended strategy: starting small, doing good and growing the program based on the lessons learned. Research limitations/implications In this study, the ecosystem’s impact on CSV at the university has been omitted. The qualitative research was based on vaguely distinguished aspects proposed by the new model. One should be cautious about considering findings as anything more than observations. Practical implications The normative model may serve as a foundation for future research or a practical guideline to higher education institutions. Originality/value The paper links CSV with USR at a strategic level supported by real examples of activities that create social and economic value. The normative model may serve as a foundation for future research or a practical guideline to higher education institutions.
CRUNCH Time na 17 Biennale Architektury w Wenecji, w Pawilonie Włoskim
- Joanna Bach-Głowińska
2021
https://arch.pg.edu.pl/strona-glowna/wydarzenia/crunch-time-na-biennale-architektury-w-wenecji-2021 https://pg.edu.pl/aktualnosci/2021-10/sukces-gdanskich-urbanistow-crunch-time-na-biennale-architektury-w-wenecji
Crystalline Polysaccharides: A Review
- Farzad Seidi
- Mohsen Khodadadi Yazdi
- Maryam Jouyandeh
- Sajjad Habibzadeh
- Muhammad Tajammal Munir
- Henri Vahabi
- Babak Bagheri
- Navid Rabiee
- Payam Zarrintaj
- Mohammad Saeb
2021 CARBOHYDRATE POLYMERS
The biodegradability and mechanical properties of polysaccharides are dependent on their architecture (linear or branched) as well as their crystallinity (size of crystals and crystallinity percent). The amount of crystalline zones in the polysaccharide significantly governs their ultimate properties and applications (from packaging to biomedicine). Although synthesis, characterization, and properties of polysaccharides have been the subject of several review papers, the effects of crystallization kinetics and crystalline domains on the properties and application have not been comprehensively addressed. This review places focus on different aspects of crystallization of polysaccharides as well as applications of crystalline polysaccharides. Crystallization of cellulose, chitin, chitosan, and starch, as the main members of this family, were discussed. Then, application of the aforementioned crystalline polysaccharides and nano-polysaccharides as well as their physical and chemical interactions were overviewed. This review attempts to provide a complete picture of crystallization-property relationship in polysaccharides.
Current divider-based nanosecond high current pulse measuring systems
- Mikołaj Nowak
- Kazimierz Jakubiuk
- Daniel Kowalak
- Marek Pikoń
- Józef Czucha
- Jacek Starzyński
2021 Pełny tekst MEASUREMENT
This paper presents the analysis of the new approach to the measurement methodology of significant values (in order of hundreds of kA) and huge steepness (in order of MA/μs) current pulses based on current dividers along with a comparison of the various types transducers suitability in measuring systems with such extreme parameters. Such dividers are used to extend the measurement ranges of current transducers with limited current conversion capabilities. The results of the selected current dividers field-circuit simulations have been presented, including their attributes and potential application as an important elements of the high-current measurement circuits. The physical prototypes of dividing systems have been verified using an experimental high-power pulse generation and forming system based on the flux compression generator and ultra-fast fuse-opening switch. As the additional aim of this study, the dividers current ratio error compensation method based on the general field-circuit model of current divider has been proposed.
Current Source Inverter Fed Drive
- Marcin Morawiec
- Arkadiusz Lewicki
2021
This book covers three-phase and multiphase (more than three-phase) motor drives including their control and practical problems faced in the field (e.g., adding LC filters in the output of a feeding converter), are considered. The new edition contains links to Matlab®/Simulink models and PowerPoint slides ideal for teaching and understanding the material contained within the book. Readers will also benefit from the inclusion of: A thorough introduction to high performance drives, including the challenges and requirements for electric drives and medium voltage industrial applications An exploration of mathematical and simulation models of AC machines, including DC motors and squirrel cage induction motors A treatment of pulse width modulation of power electronic DC-AC converter, including the classification of PWM schemes for voltage source and current source inverters Examinations of harmonic injection PWM and field-oriented control of AC machines Voltage source and current source inverter-fed drives and their control Modelling and control of multiphase motor drive system Supported with a companion website hosting online resources.
Curved Surface Minijet Impingement Phenomena Analysed with ζ-f Turbulence Model
- Tomasz Kura
- Elżbieta Fornalik-Wajs
- Jan Wajs
- Sasa Kenjeres
2021 Pełny tekst ENERGIES
The jet impingement phenomenon plays an important role among the heat transfer intensification methods. Very often its application and analyses refer to simple flat surfaces, while there is a lack of information in the literature for cases addressing curved surfaces. In the present work, the single jet impingement on the non-flat (concave and convex) surface is studied for a wide range of geometries, which originate from the mini-jet heat-exchanger design. The numerical simulations were performed by an advanced ζ-f turbulence model implemented in the open-source OpenFOAM (ESI-OpenCFD Ltd, Bracknell, United Kingdom) code. Noticeable differences in the phenomena occurring on the convex and concave surfaces were identified in the stagnation zone. Besides, the existence and location of the secondary peak in the Nusselt number distribution differed between the cases. These distributions were influenced by the shape of geometry, which determined flow characteristics and resulting heat transfer performance. The origins of these differences were looked at in the turbulence characteristics close to the impinged surface of the stagnations zone and its vicinity, where turbulence kinetic energy and enstrophy were analysed. It was stated that the differences are already noticeable for the single jet impingement case, but they might sum up when multiple jets are considered. Therefore, here presented results would be important for the analysis of the overall unit of mentioned mini-jets heat-exchanger.
CyberEye: New Eye-Tracking Interfaces for Assessment and Modulation of Cognitive Functions beyond the Brain
- Michał Lech
- Andrzej Czyżewski
- Michał Kucewicz
2021 Pełny tekst SENSORS
The emergence of innovative neurotechnologies in global brain projects has accelerated research and clinical applications of BCIs beyond sensory and motor functions. Both invasive and noninvasive sensors are developed to interface with cognitive functions engaged in thinking, communication, or remembering. The detection of eye movements by a camera offers a particularly attractive external sensor for computer interfaces to monitor, assess, and control these higher brain functions without acquiring signals from the brain. Features of gaze position and pupil dilation can be effectively used to track our attention in healthy mental processes, to enable interaction in disorders of consciousness, or to even predict memory performance in various brain diseases. In this perspective article, we propose the term ‘CyberEye’ to encompass emerging cognitive applications of eye-tracking interfaces for neuroscience research, clinical practice, and the biomedical industry. As CyberEye technologies continue to develop, we expect BCIs to become less dependent on brain activities, to be less invasive, and to thus be more applicable.
Cytocompatibility of stabilized black phosphorus nanosheets tailored by directly conjugated polymeric micelles for human breast cancer therapy
- M. Biedulska
- Paweł Jakóbczyk
- Marta Sosnowska
- Bartłomiej Dec
- A. Muchlińska
- A. J. Zaczek
- Dawid Nidzworski
- Robert Bogdanowicz
2021 Pełny tekst Scientific Reports
The novel procedure of few-layer black phosphorus (FLBP) stabilization and functionalisation was here proposed. The cationic polymer PLL and non-ionic PEG have been involved into encapsulation of FLBP to allow sufficient time for further nanofabrication process and overcome environmental degradation. Two different spacer chemistry was designed to bind polymers to tumor-homing peptides. The efficiency of functionalisation was examined by RP-HPLC, microscopic (TEM and SEM) and spectroscopic (FT-IR and Raman) techniques as well supported by ab-initio modelling. The cell and dose dependent cytotoxicity of FLBP and its bioconjugates was evaluated against HB2, MCF-7 and MDA-MB-231 cell lines. Functionalisation allowed not only for improvement of environmental stability, but also enhances therapeutic effect by abolished the cytotoxicity of FLBP against HB2 cell line. Moreover, modification of FLBP with PLL caused increase of selectivity against highly aggressive breast cancer cell lines. Results indicate the future prospect application of black phosphorus nanosheets as nanocarrier, considering its unique features synergistically with conjugated polymeric micelles.
Czy Ziemia przetrwa inwazję człowieka?
- Zygfryd Witkiewicz
- Waldemar Wardencki
- Anna Świercz
2021
Zagadnienia poruszane w książce maja charakter uniwersalny, zwracaja uwagę na zagrożenia egzystencjalne dla naszej planety. Zagrazenia te zwiazane są w dużej mierze z działalnościa czlowieka, których skutki sa przede wszystkim niepokojace zmiany klimatu i utrata bioróżnorodności. Sytuację pogarsza ciagle wzrastajaca liczba ludności, która nie chce ograniczać produkcji dóbr konsumpcyjnych, a jednocześnie wprowadza do srodowiska coraz więcej zanieczyszczeń, głównie chemicznych. Coraz wiekszym problemem staja się także zanieczyszczenia tworzywami sztucznymi i odpady komunalno-przemysłowe.
Damage detection in plates based on Lamb wavefront shape reconstruction
- Beata Zima
2021 Pełny tekst MEASUREMENT
Many of the current studies in the area of damage detection using elastic wave propagation are based on deploying sensor networks with a large number of piezoelectric transducers to detect small-size cracks. A major limitation of these studies is that cracks are usually larger and have different shapes in real cases. Moreover, using a large number of sensing nodes for damage detection is both costly and computationally intensive. The paper proposes a novel elastic wave propagation method for damage detection based on the reconstruction of the shape of the reflected wavefront. The main advantage of the developed approach is that merely three sensors are necessary to localize and estimate the size of the cracks with various sizes and shapes. Several damage cases with different number of piezoelectric transducers and placement have been investigated experimentally. Extensive numerical simulations are performed to benchmark the performance of the proposed method.
Damage Development on the Surface of Nickel Coating in the Initial Period of Erosion
- Dominika Zakrzewska
- Marta Buszko
- Alicja Krella
- Anna Komenda
- Grzegorz Mordarski
- Robert P. Socha
2021 Pełny tekst Materials
The common occurrence of the phenomenon of cavitation in many industries and the multitude of factors affecting the resistance to cavitation erosion of used materials contribute to the search for methods and appropriate parameters of coating application that are able to minimize the effects of erosion. To determine the validity of the developed application parameters and the method used, cavitation studies and microscopic observations of the development of erosion during the cavitation test were carried out. There was a clear lack of incubation time and a linear increase in losses after 60 min of the test. Moreover, the damage observed during the test overlapped, widening the area of erosion and thus leading to damage to the integrity of the coating.
DATA JOURNALS AND DATA PAPERS IN VARIOUS RESEARCH AREAS AND SCIENTIFIC DISCIPLINES – BIBLIOMETRIC ANALYSIS BASED ON INCITES
- Beata Adamczak
2021 Pełny tekst TASK Quarterly
The main aim of this work is to provide insight into a bibliometric analysis of Data Journals and Data Papers in terms of research areas, disciplines, publication year and country. In particular, we calculated many bibliometric indicators, especially: the number of publications and citations. Furthermore, this work also investigated the top 20 journals in which scientists published the largest number of Data Papers. It was found that the first Data Paper in Medical and Health Science was published in 2006. Our results indicate that about 64% of Data Papers are cited and about 30% of Data Papers are articles that have international co-authors. We also found that a significant number of Data Papers were published in top quartile (Q1) Open Access journals. Furthermore, most Data Papers were published in Multidisciplinary Sciences, followed by Biological Sciences, Earth and related Environmental Sciences as well as Computer and Information Sciences. Our analyses show that the largest number of Data Papers were published in journals with an Impact Factor ranging from 5 to 6. Additionally, the largest number of Data Papers were published in the USA, China, the United Kingdom, Italy and France. From the point of view of scientists, this work is needed because scientists can check information about journals in which they may publish research data. Moreover, they can find Data Journals with a high Impact Factor and MEiN points. This analysis is also interesting because scientists/publishers can compare the disciplines and countries in which researchers have published the greatest number of Data Papers. Finally, it is worth noting that this work gives insights into the various bibliometric indicators related to citations and the number of publications. This information can be useful for people associated with bibliometric analyses.