2021 - Repozytorium publikacji - Politechnika Gdańska

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Ultrafiltration Process in Disinfection and Advanced Treatment of Tertiary Treated Wastewater
- Rafał Bray
- Katarzyna Jankowska
- Eliza Kulbat
- Aneta Łuczkiewicz
- Aleksandra Sokołowska
2021 Pełny tekst Membranes
The paper presents the results of research on the use of ultrafiltration, using membranes of 200 and 400 kDa separation, for disinfection of municipal treated wastewater. The research was conducted on a fractional technical scale using real municipal treated wastewater from two large wastewater treatment plants treating most of the wastewater over the one-million polycentric Gdańsk agglomeration (1.2 million inhabitants). UF 200 kDa and UF 400 kDa processes enabled further improvement of the physical and chemical parameters of treated wastewater. Total phosphorus (to below 0.2 mg/L–UF 200 kDa, 0.13 mg/L–UF 400 kDa) and turbid substances (to below 0.2 mg/L, both membranes) were removed in the highest degree. COD was reduced efficiently (to below 25.6 mgO2/L–UF 200 kDa, 26.8 mgO2/L–UF 400 kDa), while total nitrogen was removed to a small extent (to 7.12 mg/L–UF 200 kDa and 5.7 mg/L–UF 400 kDa. Based on the reduction of indicator bacteria; fecal coliforms including E. coli (FC) and fecal enterococci (FE) it was found that the ultrafiltration is an effective method of disinfection. Not much indicator bacterial were observed in the permeate after processes (UF 200 kDa; FC—5 CFU/L; FE—1 CFU/L and UF 400 kDa; FC—70 CFU/L; FE—10 CFU/L. However, microscopic analysis of prokaryotic cells and virus particles showed their presence after the application of both membrane types; TCN 3.0 × 102 cells/mL–UF 200 kDa, 5.0 × 103 cells/mL–UF 400 kDa, VP 1.0 × 105/mL. The presence of potentially pathogenic, highly infectious virus particles means that ultrafiltration cannot be considered a sufficient disinfection method for treated wastewater diverted for reuse or discharged from high load wastewater treatment plants to recreational areas. For full microbiological safety it would be advisable to apply an additional disinfection method (e.g., ozonation)
Ultrasensitive electrochemical determination of the cancer biomarker protein sPD-L1 based on a BMS-8-modified gold electrode
- Paweł Niedziałkowski
- Magdalena Bojko
- Jacek Ryl
- Anna Wcisło
- Marta Spodzieja
- Katarzyna Magiera Mularz
- Katarzyna Guzik
- Grzegorz Dubin
- Tad A. Holak
- Tadeusz Ossowski
- Sylwia Rodziewicz-Motowidło
2021 Pełny tekst BIOELECTROCHEMISTRY
This work describes the modification of a gold electrode with the BMS-8 compound that interacts with the Programmed Death-Ligand 1 (PD-L1), an immune checkpoint protein. The results show that we can confirm the presence of the sPD-L1 in the concentration range of 10−18 to 10−8 M using electrochemical impedance spectroscopy (EIS) with a limit of detection (LOD) of 1.87 × 10−14 M for PD-L1 (S/N = 3.3) and at a concentration of 10−14 M via cyclic voltammetry (CV). Additionally, high-resolution X-ray photoelectron spectroscopy (XPS), contact angle, and surface free energy measurements were applied to confirm the functionalization of the electrode. We investigated the selectivity of the electrode for other proteins: Programmed Death-1 (PD-1), cluster of differentiation 160 (CD160), and B- and T-lymphocyte attenuator (BTLA) at concentrations of 10−8 M. Differentiation between PD-L1 and PD-1 was achieved based on the analysis of the capacitance effect frequency dispersion at the surface of the modified Au electrode with BMS-8 after incubation at various concentrations of PD-L1 and PD-1 proteins in the range of 10−18 to 10−8 M. Significant differences were observed in the heterogeneity of PD-L1 and PD-1. The results of the quasi-capacitance studies demonstrate that BMS-8 strongly and specifically interacts with the PD-L1 protein.
Ultrasonic-assisted Electrodeposition of Cu-Sn-TiO2 Nanocomposite Coatings with Enhanced Antibacterial Activity
- Dmitry Kharitonov
- Aliaksandr Kasach
- Denis Sergievich
- Angelika Wrzesińska
- Izabela Bobowska
- Kazimierz Darowicki
- Artur Zieliński
- Jacek Ryl
- Irina Kurilo
2021 Pełny tekst ULTRASONICS SONOCHEMISTRY
Copper-based coatings are known for their high antibacterial activity. In this study, nanocomposite Cu–Sn–TiO2 coatings were obtained by electrodeposition from an oxalic acid bath additionally containing 4 g/dm3 TiO2 with mechanical and ultrasonic agitation. Ultrasound treatment was performed at 26 kHz frequency and 32 W/dm3 power. The influence of agitation mode and the current load on the inclusion and distribution of the TiO2 phase in the Cu–Sn metallic matrix were evaluated. Results indicated that ultrasonic agitation decreases agglomeration of TiO2 particles and allows for the deposition of dense Cu–Sn–TiO2 nanocomposites. It is shown that nanocomposite Cu–Sn–TiO2 coatings formed by ultrasonic-assisted electrodeposition exhibit excellent antimicrobial properties against E. coli bacteria.
Ultrasound-assisted wet-impregnation of Ag–Co nanoparticles on cellulose nanofibers: Enhanced catalytic hydrogenation of 4-nitrophenol
- Vividha K. Landge
- Shirish H. Sonawane
- Sivakumar Manickam
- G.Uday Bhaskar Babu
- Grzegorz Boczkaj
2021 Journal of Environmental Chemical Engineering
In this study, a novel nanocomposite of bimetallic Ag–Co nanoparticles supported on cellulose nanofibers (CNFs) was synthesised using the ultrasound-assisted wet-impregnation method for catalytic applications. CNFs were prepared from cellulose acetate using the electrospinning technique. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the successful synthesis of CNFs. Further, scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) revealed a uniform dispersion of Ag and Co metals on the CNFs. At the same time, X-Ray diffraction (XRD) spectra indicated the highly crystalline nature of the as-produced composite. The hydrogenation of 4-nitrophenol (4-NP) was used to study the efficiency of the synthesised nanocomposite. The progress of the reaction was examined via UV–visible spectroscopy. It was noted that Ag-Co nanoparticles supported on CNFs catalysed the hydrogenation of 4-NP (0.1 mM) to 4-aminophenol within just 110 s with an apparent rate constant of 0.0172 s−1. This study proved that the obtained catalysts have superior stability and reusability with about 100% conversion up to 5 cycles. The excellent activity of the as-synthesised Ag-Co/CNFs nanocomposites makes it a promising nanocatalyst for catalytic applications.
Understanding Knowledge-Intensive Business Services. Identification, Systematization, and Characterization of Knowledge Flows
- Małgorzata Zięba
2021 Pełny tekst
This book contributes to an improved understanding of knowledge-intensive business services and knowledge management issues. It offers a complex overview of literature devoted to these topics and introduces the concept of ‘knowledge flows’, which constitutes a missing link in the previous knowledge management theories. The book provides a detailed analysis of knowledge flows, with their types, relations and factors influencing them. It offers a novel approach to understand the aspects of knowledge and its management not only inside the organization, but also outside, in its environment.
Understanding the capacitance of thin composite films based on conducting polymer and carbon nanostructures in aqueous electrolytes
- Anita Cymann-Sachajdak
- Magdalena Graczyk-Zajac
- Grzegorz Trykowski
- Monika Wilamowska-Zawłocka
2021 Pełny tekst ELECTROCHIMICA ACTA
In this work electrochemical performance of thin composite films consisted of poly(3,4-ethylenedioxythiophene) (PEDOT), graphene oxide (GOx) and oxidized multiwalled carbon nanotubes (oxMWCNTs) is investigated in various sulphates (Li2SO4, Na2SO4, K2SO4, MgSO4) and acidic (H2SO4) electrolytes. Capacitance values, rate capability and cycling stability achieved for the composite layers are correlated with the electrolytes’ properties such as the conductivity, viscosity, cation size and pH. The highest capacitance values are achieved in acidic solution (98.6 mF cm−2 at 1 mA cm−2), whereas cycling stability is better in neutral electrolytes (88.4% of initial capacitance value after 10’000 cycles recorded for symmetric supercapacitor in 0.5 M MgSO4 solution). Diffusion controlled and non-diffusion controlled capacitance contributions are calculated and the results are discussed considering various ranges of sweep rates taken into account in the linear fitting and extrapolation of parameters.
Understanding the interactions between protein stabilizers and the peptide bond through the analysis of the volumetric and compressibility properties for the model systems
- Emilia Kaczkowska
- Jarosław Wawer
- Magdalena Tyczyńska
- Małgorzata Jóźwiak
- Joanna Krakowiak
2021 Pełny tekst JOURNAL OF CHEMICAL THERMODYNAMICS
This work confirms our earlier supposition, that volumetric and acoustic parameters for simple model proposed by us are directly related to stabilizing/destabilizing effect of osmolytes on proteins structure. The apparent molar volumes, V and the apparent molar isentropic compressions, KS,, of glycine and N,N,N –trimethylglycine (betaine) were determined from densities and speed of sound measurements in aqueous solution of N-methylacetamide (as a model of peptide bond of protein). The standard molar parameters for osmolytes were obtained from concentration dependence of the calculated quantities at NMA concentration equal 2, 4, 6 and 8 (mol/kg) and at temperature T = (288.15, 298.15 and 308.15) K. The standard values were combined with volumetric and compressibility data for amino acids in pure water to obtain transfer properties from water to aqueous N-methylacetamide solutions. The standard partial molar volume of transfer of studied osmolytes, 〖Δ_t V〗_Φ^0, seems to be related mainly to hydrophilic/hydrophobic features of molecules. The stabilizing/destabilizing effect of solute on protein structure is reflected in temperature influence on the limiting partial molar quantities.
Underwater acoustic communication system using broadband signal with hyperbolically modulated frequency
- Jan Schmidt
- Aleksander Schmidt
2021 Pełny tekst Vibrations in Physical Systems
The implementation of reliable acoustic underwater communication in shallow waters is a scientific and engineering challenge, mainly due to the permanent occurrence of the multipath phenomenon. The article presents the concept of a transmission system using a broadband signal with hyperbolically modulated frequency (HFM) to transmit data symbols and synchronize data frames. The simulation tests were carried out in channels with Rician fading, reflecting the short- and mediumrange shallow water channels. The simulation also took into account the presence of additive Gaussian noise in the channel on the functioning of the receiver. The obtained results prove the high reliability of the underwater communication system based on broadband HFM signals.
Unexpected Z/E isomerism of N-methyl-O-phosphothioyl benzohydroxamic acids, their oxyphilic reactivity and inertness to amines
- Arkadiusz Majewski
- Jarosław Chojnacki
- Witold Przychodzeń
2021 Pełny tekst STRUCTURAL CHEMISTRY
Thiophosphinoylation of N-methyl p-substituted benzohydroxamic acids using disulfanes (method A) or diphenylphosphinothioyl chloride (method B) provides only one conformer of the respective O-phosphothioyl derivative (Xray and NMR analysis). Undergoing the P-transamidoxylation reaction is an evidence of the reversibility of thiophosphinoylation. Only those products containing strong EWG substituents in the aroyl residue or bulky substituents at the phosphorus atom possess E conformation. DFT calculations confirmed the energetic domination of each isomer. The Z-isomers are distorted amides having both high degree of nitrogen pyramidalization (38–55°) and amide twist (12–30°). In solution they exist in a defined conformation that is evidenced by the presence of a sharp signal of N-methyl protons at low temperature. They do not isomerize in solutions. Some of them slowly undergo the N-O bond scission above 100 °C. Both isomers are not as sensitive to neutral hydrolysis as twisted amides can be and are inert toward amines. The rate of alkaline hydrolysis can be correlated with pKa of hydroxamic acid. Because of their outstanding oxyphilicity, these compounds can be defined as nerve agent surrogates and safer alternatives of phosphorus fluorides for serine-active enzyme inhibition studies
Unity-Gain Zero-Offset CMOS Buffer with Improved Feedforward Path
- Waldemar Jendernalik
- Jacek Jakusz
- Robert Piotr Piotrowski
- Grzegorz Blakiewicz
- Stanisław Szczepański
2021 Pełny tekst Electronics
A voltage unity-gain zero-offset CMOS amplifier with reduced gain error and increased PSRR (power supply rejection ratio) is proposed. The amplifier uses two feed mechanisms, negative feedback and supporting positive feedforward, to achieve low deviation from unit gain over the entire input range. The circuit, designed in a standard 180-nanometer 1.8-voltage CMOS process, is compared with two known buffers of similar topology, also designed in the same process. Simulations show that, with the same supply (1.8 V), power (1.2 mW), load (12 pF), bandwidth (50 MHz), and similar area (600 m2), the proposed buffer achieves the lowest gain error (0.3%) and the highest PSRR (72 dB).
University Students’ Research on Artificial Intelligence and Knowledge Management. A Review and Report of Multi-case Studies
- Mieczysław Owoc
- Paweł Weichbroth
2021 Pełny tekst
Leading technologies are very attractive for students preparing their theses as the completion of their studies. Such an orientation of students connected with professional experiences seems to be a crucial motivator in the research in the management and business areas where these technologies condition the development of professional activities. The goal of the paper is the analysis of students’ thesis topics defended in the last 10 years in business informatics and computer science in two selected universities in Poland. Our study relies on a detailed review and analysis of qualitative data, obtained from a literature review and multi-case-study research. In the case of the artificial intelligence domain, we have identified six areas of research, namely: general AI, machine learning (ML), natural language processing (NLP), artificial neural networks (ANNs), expert systems, and hybrids. In the case of the knowledge management domain, we have recognized eleven areas of research, regarding the following sectors: e-government, technology, space exploration, social media, manufacturing, healthcare, finance, entertainment, education, e-commerce, and business. Future research will be directed toward extending the scope by including other regions and universities as well as identifying and analyzing students’ motivational factors, associated with research projects and higher education.
Uniwersalny Kontroler Radiowy w systemie STRADAR
- Sylwester Kaczmarek
- Mariusz Miszewski
- Marcin Wyczyński
2021 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
Opisano praktyczne rozwiązanie uniwersalnego kontrolera radiowego UKR – jednego z podstawowych elementów funkcjonalnych systemu STRADAR – który obsługuje sensory wykorzystywane na granicy morskiej państwa. Jest on także odpowiedzialny za komunikację personelu Straży Granicznej. UKR ma dwie wersje, jedną mobilną – na jednostki pływające, pojazdy lądowe i jednostki latające, drugą stacjonarną – na stałe punkty obserwacyjne rozmieszczone wzdłuż granicy. Urządzenie to uzyskało pozytywny wynik testów akceptacyjnych oraz badań certyfikacyjnych i osiągnęło IX poziom gotowości technologii.
Upamiętnianie w zdecentralizowanej formule
- Agnieszka Gębczyńska-Janowicz
2021
Realizacje kommemoratywne tworzone obecnie w przestrzeni publicznej udowadniają, e definicja pomnika jest niejednoznaczna, wynika z różnych aspektów twórczości i dostosowuje się do kontekstu kulturowego epoki. Celem artykułu jest analiza współczenej realizacji formuły zdecentralizowanej.
Uptake, accumulation, and translocation of Zn, Cu, Pb, Cd, Ni, and Cr by P. australis seedlings in an urban dredged sediment mesocosm: impact of seedling origin and initial trace metal content
- Nicole Nawrot
- Ewa Wojciechowska
- Ksenia Pazdro
- Jacek Szmagliński
- Janusz Pempkowiak
2021 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT
The study presents results from 6 months of phytoremediation of sediments dredged from three urban retention tanks carried out in a mesocosm setup with the use of P. australis. Two kinds of P. australis seedlings were considered: seedlings originating from natural (uncontaminated - Suncont) and anthropogenically changed environments (contaminated – Scont); this distinction was reflected in the baseline concentrations of trace metals inside their tissues. The potentially toxic elements (PTEs) considered in this study were as follows: Zn, Cu, Cd, Ni, Cr, and Pb. The aim of the study was to compare the uptake, accumulation, and translocation properties of seedlings with different initial trace metal contents. The PTE concentrations were analyzed in sediments as well as in belowground and aboveground parts of plants in the middle (3rd month) and at the end of the investigation period using inductively coupled plasma mass spectrometry (ICP-MS), and the accumulation of PTEs in plant tissues was calculated. Phytoextraction efficiency was evaluated using the bioconcentration factor (BF) and translocation factor (TF). Plant morphology was assessed with scanning electron microscopy (SEM) to document plant stress due to PTE exposure. The results of our study indicated that P. australis seedlings originating from sites differing in the initial trace metal content exhibited different behavior when grown on sediments dredged from urban retention tanks. Suncont seedlings with low initial metal contents tended to adapt to the dredged sediments and showed phytoextraction ability, while Scont seedlings originating from sites with initial high contents of trace metals acted as phytoexcluders and tended to release PTEs from their tissues into the sediments. The morphological and structural effects caused by metal toxicity were observed in growth limitation, root tissue disturbance, root hair number decrease, and structural alterations in the epidermis and endodermis. Therefore, the Suncont seedlings presented better properties and adaptability for phytoremediation purposes.
Urban Lighting Research Transdisciplinary Framework—A Collaborative Process with Lighting Professionals
- Catherine Vega, Pérez
- Karolina Zielińska-Dąbkowska
- Franz Hölker
2021 Pełny tekst International Journal of Environmental Research and Public Health
Over the past decades, lighting professionals have influenced the experience of the night by brightly illuminating streets, buildings, skylines, and landscapes 24/7. When this became the accepted norm, a dual perspective on night-time was shaped and the visual enjoyment of visitors after dusk was prioritized over natural nightscapes (nocturnal landscapes). During this time, researchers of artificial light at night (ALAN) observed and reported a gradual increase in unnatural brightness and a shift in color of the night-time environment. As a consequence, ALAN has been identified as a relevant pollutant of aquatic and terrestrial habitats, and an environmental stressor, which may adversely affect a wide range of organisms, from micro-organisms to humans. Unfortunately, lighting professionals and ALAN researchers usually attempt to solve today’s sustainable urban lighting problems distinctive to their fields of study, without a dialogue between research and practice. Therefore, in order to translate research knowledge as an applicable solution for the lighting practice and to minimize the impact on the environment, a collaborative framework involving a transdisciplinary process with lighting professionals is crucial to potentially bring the practice, research, production, decision-making, and planning closer to each other. This paper presents a framework to help reduce the existing gap of knowledge, because appropriate lighting applications depend upon it. Access to less light polluted nightscapes in urban environments is just as important as access to unpolluted water, food, and air. This call for action towards sustainable urban lighting should be included in future lighting policies to solve the urgent environmental and health challenges facing our world.
Use of Bi-Temporal ALS Point Clouds for Tree Removal Detection on Private Property in Racibórz, Poland
- Patrycja Przewoźna
- Paweł Hawryło
- Karolina Zięba-kulawik
- Adam Inglot
- Krzysztof Mączka
- Piotr Wężyk
- Piotr Matczak
2021 Pełny tekst Remote Sensing
Trees growing on private property have become an essential part of urban green policies. In many places, restrictions are imposed on tree removal on private property. However, monitoring compliance of these regulations appears difficult due to a lack of reference data and public administration capacity. We assessed the impact of the temporary suspension of mandatory permits on tree removal, which was in force in 2017 in Poland, on the change in urban tree cover (UTC) in the case of the municipality of Racibórz. The bi-temporal airborne laser scanning (ALS) point clouds (2011 and 2017) and administrative records on tree removal permits were used for analyzing the changes of UTC in the period of 2011–2017. The results show increased tree removal at a time when the mandatory permit was suspended. Moreover, it appeared that most trees on private properties were removed without obtaining permission when it was obligatory. The method based on LiDAR we proposed allows for monitoring green areas, including private properties.
Using deep learning to increase accuracy of gaze controlled prosthetic arm
- Tomasz Kocejko
2021
This paper presents how neural networks can be utilized to improve the accuracy of reach and grab functionality of hybrid prosthetic arm with eye tracing interface. The LSTM based Autoencoder was introduced to overcome the problem of lack of accuracy of the gaze tracking modality in this hybrid interface. The gaze based interaction strongly depends on the eye tracking hardware. In this paper it was presented how the overall the accuracy can be slightly improved by software solution. The cloud of points related to possible final positions of the arm was created to train Autoencoder. The trained model was next used to improve the position provided by the eye tracker. Using the LSTM based Autoencoder resulted in nearly 3% improvement of the overall accuracy.
Using Evidence-based Arguments to Support Dependability Assurance - Experiences and Challenges
- Janusz Górski
2021 ACM SIGAda Ada Letters
The presentation introduces to the problem of evidence-based arguments and their applications. Then, based on the experiences collected during development and commercial deployment of a concrete solution to this problem (system NOR-STA) we overview selected challenges and the ways of addressing them.
Using FreeFEM open software for modelling the vibrations of piezoelectric devices
- Marek Moszyński
2021 Pełny tekst Vibrations in Physical Systems
Modelling vibrations of piezoelectric transducers has been a topic discussed in the literature for many decades. The first models - so-called one-dimensional - describe the vibrations only near operating frequency and near its harmonics. Attempts to introduce two-dimensional models were related to the possibility of one transducer working at several frequencies, including both thickness vibrations and those resulting from the transducer horizontal dimensions. In recent decades, thanks to the use of the finite element method and its derivatives, and the progress related to the increase in processor speed and memory availability, the implementation of models based on three-dimensional modelling is possible using software on personal computers. As the implementation of finite element method algorithms is characterized by high complexity, several professional software packages have been created on the commercial market, among which only a few implement the piezoelectric equations. In this context, this article presents how to use open source software along with developed programming language for intuitive definition of piezoelectric equations and its solution.
Using the ultrasonic tomography method to study the condition of wooden beams from historical buildngs
- Monika Zielińska
- Magdalena Rucka
2021
The need to evaluate the integrity of wooden structural elements is constantly increasing. Non-destructive methods are becoming more popular in this field of research. One type of non-destructive testing is the ultrasonic imaging method, which allows the analysis of internal wood structures without disturbing their state and integrity. In this study, we are interested in assessing the effect of wood condition on the ultrasound time of flight (TOF). The research was carried out on wooden beams, which were obtained from a historical building. The images obtained from ultrasound tomography were compared with results of a visual inspection.Places of discontinuities, voids and cracks in wood caused a much lower velocity of wave propagation.The location of the wood core was illustrated by the places with the highest velocity. The article proved the validity of using ultrasonic tomography to assess the technical condition of historic wooden beams.