2021 - Repozytorium publikacji - Politechnika Gdańska

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In Search for Answers: Light4Health Online Course of Health Research for Interior Lighting Design
- Karolina Zielińska-Dąbkowska
2021 Pełny tekst ARC Lighting In Architecture
Three years ago, when I wrote an article in arc called: Human Centric Lighting. The New X Factor? (arc no. 108 Feb/Mar 2019), my intention was to raise questions in relation to the new topic and to find solid, research-based answers in the years to come. Today, I am happy to report that the lighting community, with the Light4Health Online Course of Health Research for Interior Lighting Design, has a useful tool, and consortium members have managed to close the gap between research and practice/application, and translate complex research into an ‘easy to digest’ format for end users.
In silico assessment and sonochemical synthesis of 2-alkynyl 3-chloropyrazines as prospective ligands for SARS-CoV-2
- M.v. Satyanarayana
- Alugubelli Gopi Reddy
- M. Yedukondalu
- Mandava Bhuvan Tej
- Kazi Hossain
- Mandava Venkata Basaveswara Rao
- Manojit Pal
2021 Pełny tekst JOURNAL OF MOLECULAR STRUCTURE
The recent global pandemic caused by COVID-19 has triggered an intense effort worldwide towards the development of an effective cure for this disease. In our effort we have explored the 2-alkynyl substituted 3-chloropyrazine framework as a potential template for the design of molecules for this purpose. Our strategy was supported by the in silico studies of representative compounds to assess their binding affinities via docking into the N-terminal RNA-binding domain (NTD) of N-protein of SARS-CoV-2. Thus we created a small library of molecules based on the aforementioned template via an environmentally safer method that involved the rapid synthesis of 2-alkynyl 3-chloropyrazine derivatives under Cu-catalysis assisted by ultrasound. The reactions proceeded via the coupling of 2,3-dichloropyrazine with commercially available terminal alkynes in the presence of CuI, PPh3 and K2CO3 in PEG-400. Further molecular modelling studies helped in establishing a virtual SAR (Structure Activity Relationship) within the series and identification of three potential hits. The desirable ADME was also predicted for these three molecules suggesting their prospective medicinal value.
In Vitro Dissolution of Na-Ca-P-Oxynitrides
- Natalia Wójcik
- Polina Sinitsyna
- Sharafat Ali
- Leena Hupa
- Bo Jonson
2021 Pełny tekst Materials
: Sodium-calcium-phosphate based oxynitride glasses and glass-ceramics doped with Mg, Si, and Nb were studied in vitro in simulated body fluid (SBF) under static conditions. The release of ions and pH changes up to 7 days of immersion were investigated. The nitrogen incorporation into phosphate glass matrix was found to notably influence in vitro dissolution only of homogenous glasses. Increasing the nitrogen content in the samples decreased the mean mass loss, while the niobate incorporation increased it. The correlation between the nitrogen content and increase in pH of SBF was also observed. The presence of phosphates crystallites was found to support the dissolution process at the beginning step (up to 3 days).
Inception and Propagation of Electrical Trees in the Presence of Space Charge in HVAC Extruded Cables
- Mohammad AlShaikh Saleh
- Shady S. Refaat
- Marek Olesz
- Haitham Abu-Rub
2021 IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
This paper presents the space charge impact on the inception and propagation of electrical trees in cross-linked polyethylene (XLPE) insulation via simulations and experimentation. A 3D finite element analysis (FEA)-based modeling is proposed to simulate electrical trees via a needle embedded on the XLPE insulation. The proposed FEA model demonstrates the influence of the space charge magnitude and polarity on the initiation of partial discharges (PD). Then the critical parameters at the tip of an 8 tree are to be examined. Experimentation is necessary to verify the simulation results acquired and study the mechanism of electrical trees at the inception and propagation stage. Therefore, in the experiment, a needle with a curvature radius of 5 is embedded in the XLPE as a method of simulating defects, such as protrusions, voids, or cracks found in cable insulation. The power source supplies several high AC voltages on the 20 kV (rated voltage) cable under test for observing the inception and propagation behavior of the electrical trees. Phase-resolved partial discharge (PRPD) patterns are extracted at the inception and propagation stages of the electrical tree to determine the severity of the PDs occurring. A relationship is obtained for the PD magnitude with respect to the applied AC voltage while considering the positive and negative polarities of the PDs. This relationship then allows for the acquisition of the maximum electric field-tree length characteristics. The goal of the simulation of electrical trees is to provide the reader with a better understanding about the effect of space charge magnitude and polarity to comprehend the behavior of the treeing inception and propagation mechanisms. The injection and extraction of space charges is a complex phenomenon that requires further visualization through simulations. Therefore, the results of both the simulation and experiment are compared with the aim of establishing a clear relationship between space charge distribution and tree initiation.
Inclusive Communication Model Supporting the Employment Cycle of Individuals with Autism Spectrum Disorders
- Michał Tomczak
- Joanna Maria Szulc
- Małgorzata Szczerska
2021 Pełny tekst International Journal of Environmental Research and Public Health
Difficulties with interpersonal communication experienced by individuals with autism spectrum disorders (ASD) significantly contribute to their underrepresentation in the workforce as well as problems experienced while in employment. Consistently, it is vital to understand how communication within the employment cycle of this group can be improved. This study aims to identify and analyze the possibilities of modifying the communication processes around recruitment, selection, onboarding, and job retention to address the specific characteristics and needs of the representatives of this group. This qualitative study is based on 15 in-depth interviews conducted with 21 field experts, i.e.,: therapists, job trainers, and entrepreneurs employing people with ASD. The findings of this research informed the creation of an inclusive communication model supporting the employment cycle of individuals with ASD. The most important recommendations within the model that was created include the modification of job advertisements, use of less structured job interviews, providing opportunities for mentorship, and supportive and non-direct, electronically mediated communication. To apply the above-mentioned solutions and take full advantage of the talents of people with ASD, it is also necessary to provide tailored sensitivity and awareness training programs for their direct addressees as well as their neurotypical colleagues, including managerial staff.
Incorporation of nitrogen in diamond films – A new way of tuning parameters for optical passive elements
- Monika Kosowska
- Sandra Pawłowska
- Kamatchi J Sankaran
- Daria Majchrowicz
- Ken Haenen
- Kishan Dholakia
- Małgorzata Szczerska
2021 DIAMOND AND RELATED MATERIALS
This paper investigates the impact of nitrogen incorporation in diamond films for the construction of an interferometric sensor to measure displacement. Diamond films with different nitrogen levels (0–5%) were deposited on silicon substrates by microwave plasma enhanced chemical vapor deposition. The structural characteristics of these samples are characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), confocal micro-Raman spectroscopy, and electron energy loss spectroscopy (EELS). The homogeneous and continuous surface morphology of the films is observed through SEM. In the micro-Raman and electron energy loss spectroscopy studies, it is evident that there is a formation of sp2 -bonded carbon phases due to the increase in the concentration of nitrogen. This investigation gives a strong basis for utilizing these diamond films as reflective layers in fiber-optic devices. The interferometric measurement setup is constructed as a Fabry-P´erot interferometer. The nitrogen incorporated films are proved to be useful as mirrors as they achieve a measurement signal with high contrast. The achieved visibility values for the investigated samples are higher than 94% in the range of 40–100 μm.
Incorporation of the complete ammonia oxidation (comammox) process for modeling nitrification in suspended growth wastewater treatment systems
- Mohammad Javad Mehrani
- Lu Xi
- Przemysław Kowal
- Dominika Sobotka
- Jacek Mąkinia
2021 Pełny tekst JOURNAL OF ENVIRONMENTAL MANAGEMENT
The newly discovered process complete ammonia oxidation (comammox) has changed the traditional under-standing of nitrification. In this study, three possible concepts of comammox were developed and incorporated as part of an extended two-step nitrification model. For model calibration and validation, two series of long-term biomass washout experiments were carried out at 12 ◦C and 20 ◦C in a laboratory sequencing batch reactor. The inoculum biomass was withdrawn from a large biological nutrient removal wastewater treatment plant. The efficiency of the examined models was compared based on the behaviors of ammonia, nitrite, and nitrate in the studied reactor. Predictions of the conventional approach to comammox, assuming the direct oxidation of ammonia to nitrate, were slightly better than the two other approaches. Simulation results revealed that comammox could be responsible for the conversion of >20% of the influent ammonia load. Therefore, the role of commamox in the nitrogen mass balance in activated sludge systems should not be neglected and requires further investigation. Furthermore, sensitivity and correlation analysis revealed that the maximum growth rates (μ), oxygen half-saturation (KO), and decay rates (b) of the canonical nitrifiers and comammox were the most sen-sitive factors, and the highest correlation was found between μ and b among all considered kinetic parameters. The estimated μ values by the best model were 0.57, 0.11, and 0.15 d.
Independent Domination Subdivision in Graphs
- Ammar Babikir
- Magda Dettlaff
- Michael A. Henning
- Magdalena Lemańska
2021 Pełny tekst GRAPHS AND COMBINATORICS
A set $S$ of vertices in a graph $G$ is a dominating set if every vertex not in $S$ is adjacent to a vertex in~$S$. If, in addition, $S$ is an independent set, then $S$ is an independent dominating set. The independent domination number $i(G)$ of $G$ is the minimum cardinality of an independent dominating set in $G$. The independent domination subdivision number $\sdi(G)$ is the minimum number of edges that must be subdivided (each edge in $G$ can be subdivided at most once) in order to increase the independent domination number. We show that for every connected graph $G$ on at least three vertices, the parameter $\sdi(G)$ is well defined and differs significantly from the well-studied domination subdivision number $\sdg(G)$. For example, if $G$ is a block graph, then $\sdg(G) \le 3$, while $\sdi(G)$ can be arbitrary large. Further we show that there exist connected graph $G$ with arbitrarily large maximum degree~$\Delta(G)$ such that $\sdi(G) \ge 3 \Delta(G) - 2$, in contrast to the known result that $\sdg(G) \le 2 \Delta(G) - 1$ always holds. Among other results, we present a simple characterization of trees $T$ with $\sdi(T) = 1$.
Independent dynamics of low, intermediate, and high frequency spectral intracranial EEG activities during human memory formation
- Victoria Marks
- Krishnakant Saboo
- Çağdaş Topçu
- Michał Lech
- Theodore Thayib
- Petr Nejedly
- Vaclav Kremen
- Gregory A. Worrell
- Michał Kucewicz
2021 Pełny tekst NEUROIMAGE
A wide spectrum of brain rhythms are engaged throughout the human cortex in cognitive functions. How the rhythms of various frequency ranges are coordinated across the space of the human cortex and time of memory processing is inconclusive. They can either be coordinated together across the frequency spectrum at the same cortical site and time or induced independently in particular bands. We used a large dataset of human intracranial electroencephalography (iEEG) to parse the spatiotemporal dynamics of spectral activities induced during formation of verbal memories. Encoding of words for subsequent free recall activated low frequency theta, intermediate frequency alpha and beta, and high frequency gamma power in a mosaic pattern of discrete cortical sites. A majority of the cortical sites recorded activity in only one of these frequencies, except for the visual cortex where spectral power was induced across multiple bands. Each frequency band showed characteristic dynamics of the induced power specific to cortical area and hemisphere. The power of the low, intermediate, and high frequency activities propagated in independent sequences across the visual, temporal and prefrontal cortical areas throughout subsequent phases of memory encoding. Our results provide a holistic, simplified model of the spectral activities engaged in the formation of human memory, suggesting an anatomically and temporally distributed mosaic of coordinated brain rhythms.
Indoor accelerated controlled corrosion degradation test of small- and large-scale specimens
- Krzysztof Wołoszyk
- Yordan Garbatov
- Jakub Kowalski
2021 Pełny tekst OCEAN ENGINEERING
The work presented here is a part of a long-term project analysing the structural behaviour of ageing marine structures. An accelerated corrosion degradation set-up was developed to reproduce corroded marine structural specimens of different degrees of degradation, controlling various natural factors, i.e., temperature, oxygen content, salinity, and flow velocity. The nine stiffened plates of 1.2 m length and 30 small scale specimens made of mild steel of three different thicknesses have been corroded. The mean corrosion depth and rate have been controlled during the degradation process for all specimens. The corrosion degradation characteristics have been measured and analysed. In the case of small-scale specimens, microscope scanning, and for the stiffened plates, ultrasonic thickness measurements were performed. The obtained corrosion surfaces are highly non-uniform. During the corrosion degradation, a number of measurements were performed to satisfy a confidence level of 95% and an error of 10%. The developed corrosion degradation is compared with a real corrosion depth measurement of ship deck plates of ballast and cargo tanks, showing a very good similarity in the trend and the corrosion acceleration, concluding that the developed corrosion degradation controlled experimental set-up is efficient in reproducing marine structural specimens of different degree of degradation for further mechanical testing.
Induction Assisted Hybrid Friction Stir Welding of Dissimilar Materials AA5052 Aluminium Alloy and X12Cr13 Stainless Steel
- Dhanesh G. Mohan
- Jacek Tomków
- S Gopi
2021 Pełny tekst Advances in Materials Science
This research aimed to study the induction in-situ heated hybrid friction stir welding (IAFSW) method to join AA5052 aluminium alloy with X12Cr13 stainless steel (SS) to enhance joint strength. The potency of this method on the mechanical properties and microstructural characterizations were also investigated. The results show that the transverse tensile strength gained was 94% of the AA5052 base metal that is 229.5 MPa. This superior strength was achieved due to the annealing that happened to the AA 5052 region and elevated plastic flow in the weld zone by the in-situ induction heating, which resulted in the elongation of the weld region. The microstructure characterization indicates that a refined grain structure was gained in the nugget zone without defects.
Influence of alkali metal cations on the photoactivity of crystalline and exfoliated amorphous WO3 – photointercalation phenomenon
- Mariusz Szkoda
- Konrad Trzciński
- Grzegorz Trykowski
- Marcin Łapiński
- Anna Lisowska-Oleksiak
2021 Pełny tekst APPLIED CATALYSIS B-ENVIRONMENTAL
In order to investigate the effect of photointercalation on photoelectrochemical properties, two types of WO3-based photoanodes, bulk and exfoliated have been prepared and investigated. An aqueous exfoliation method is introduced for the simple fabrication of amorphous and hydrated WO3 nanomaterial using commercial bulk WO3 precursor. The comparison of obtained material with bulk WO3 was performed using Raman, UV–vis, and XPS as well as scanning and transmission electron microscopies. The photoelectrochemical and photocatalytic performances of bulk and exfoliated WO3 were compared. Generally, the proposed exfoliation procedure led to the preparation of photo(electro)catalyst characterized by better performance measured as a photocurrent of water oxidation and rate of methylene blue photodecomposition. The main aim of this research was to investigate the influence of alkali metal cations (Li+,Na+,K+,Cs+) presence in electrolyte on the photocatalytic and photo(electro)catalytic activity of the samples in a form of suspended powder and thin layer on transparent-conductive substrate (FTO), respectively.
Influence of Annealing Atmospheres on Photoelectrochemical Activity of TiO2 Nanotubes Modified with AuCu Nanoparticles
- Wiktoria Lipińska
- Katarzyna Grochowska
- Jacek Ryl
- Jakub Karczewski
- Siuzdak Katarzyna
2021 ACS Applied Materials & Interfaces
In this article, we studied the annealing process of AuCu layers deposited on TiO2 nanotubes (NTs) conducted in various atmospheres such as air, vacuum, argon, and hydrogen in order to obtain materials active in both visible and UV–vis ranges. The material fabrication route covers the electrochemical anodization of a Ti plate, followed by thin AuCu film magnetron sputtering and further thermal treatment. Scanning electron microscopy images confirmed the presence of spherical nanoparticles (NPs) formed on the external and internal walls of NTs. The optical and structural properties were characterized using UV–vis, X-ray diffraction, and X-ray photoelectron spectroscopies. It was proved that thermal processing under the argon atmosphere leads to the formation of a CuAuTi alloy in contrast to materials fabricated in air, vacuum, and hydrogen. The electrochemical measurements were carried out in NaOH using cyclic voltammetry, linear voltammetry, and chronoamperometry. The highest photoactivity was achieved for materials thermally treated in the argon atmosphere. In addition, the Mott–Schottky analysis was performed for bare TiO2 NTs and TiO2 NTs modified with gold copper NPs indicating a shift in the flatband potential. Overall, thermal processing resulted in changes in optical and structural properties as well as electrochemical and photoelectrochemical activities.
Influence of Bingham fluid viscosity on energy performances of a vortex chamber pump
- Andrii Rogovyi
- Vladimir Korohodskyi
- Ievgen Medvediev
2021 ENERGY
One of the problems in the development of coal-water technologies is the use of reliable and long-lasting pumps. To date, classic pumps, due to the use of mechanical moving parts and seals, are subject to rapid abrasive wear. The solution to this problem can lie in the creation of new vortex chamber pumps developed by the authors. They are highly reliable, simple in design and have no moving parts. The object of this paper consists in determining the range of vortex chamber pump performance when pumping Bingham fluids of different rheological parameters, as well as to determine the dependence of the pump efficiency on the Bingham viscosity and the yield stress. Study of the pump performance was conducted experimentally and with CFD simulation. It was found that an increase in the liquid viscosity reduces the vacuum value near the axis. For the first time it was found that the tenfold increase in plastic viscosity reduces the pump efficiency by about 20%. This results in the fact that the supercharger cannot pump the coal-water slurry with Pa and Pa s. The findings can be extended not only to coal-water slurry, but also to all Bingham fluids.
Influence of drying mode and feed per tooth rate on the fine dust creation in pine and beech sawing on a mini sash gang saw
- Tomasz Rogoziński
- Daniel Chuchała
- Marta Pędzik
- Kazimierz Orłowski
- Ladislav Dzurenda
- Tomasz Muziński
2021 Pełny tekst European Journal of Wood and Wood Products (HOLZ ALS ROH-UND WERKSTOFF)
The experimental results of the study focused on the effect of drying processes of modified air drying and warm air steam mixture drying of pine and beech wood on the size of sawdust particles created in cutting using PRW-15M sash gang saw, are presented in the paper. Particle size analysis of dry sawdust was performed using two methods—sieving method and laser diffraction analysis. The results showed that the drying process did not affect the general particle size distribution of the sawdust, but the content of very fine dust particles in beech wood sawdust is many times higher when the beech wood was dried in the warm air-steam mixture drying process and sawn at a feed per tooth of 0.105 mm.
Influence of effective width of flange on calculation and reinforcement dimensioning of beam of reinforced concrete frame
- Maciej Solarczyk
2021 Pełny tekst Budownictwo i Architektura
The paper analyses the influence of modelling the cross-section of a beam in two-storey reinforced concrete frame of industrial warehouse with dimensions: 18.0 m × 32.0 m using bar elements on the results of bending moments, the value of elastic deflection and the dimensioning of reinforcement due to bending. Six options were considered: a beam as a rectangular section and five T-beam variants with different definitions of effective flange width. The differences in obtained results were commented on. Conclusions useful for the designing of reinforced concrete structures were presented. The procedure for determining the effective flange width in the context of PN-EN 1992-1-1:2008 and PN-B 03264:2002 standards with a commentary on the use of effective flange width in calculations and construction of reinforcement in reinforced concrete structures were described. Brief description of determining the reinforcement due to bending according to the simplified method given in PN-EN 1992-1-1:2008 was presented. In addition, the standard formula for determining the minimum cross sectional area of reinforcement (9.1N) in PN-EN 1992-1-1:2008 with a proposal for its strict determination for the T-beam with the flange in tension was analyzed.
Influence of Escherichia coli on Expression of Selected Human Drug Addiction Genes
- Roman Kotłowski
2021 Pełny tekst Life
The impact of enteric microflora on the expression of genes associated with cocaine and amphetamine addiction was described. Human genome-wide experiments on RNA transcripts expressed in response to three selected Escherichia coli strains allowed for significant alteration (p > 0.05) of the linear regression model between HT-29 RNA transcripts associated with the KEGG pathway:hsa05030:Cocaine addiction after 3 h stimulation with intracellular pathogenic E. coli strain UM146 versus non-pathogenic E. coli Nissle 1917. Among the features influenced by the UM146 bacterial strain were visual learning, response to the presence of morphine, response to hypoxia, behavioral fear response and cognitive functions.
Influence of Gaps’ Geometry Change on Leakage Flow in Axial Piston Pumps
- Piotr Patrosz
2021 Pełny tekst
Axial piston pumps are the core elements of most medium and high-pressure hydraulic systems. High volumetric efficiency and high working pressures are the main advantages of this type of pumps. Therefore it is necessary to accurately calculate the leakage flow through the gaps to design efficient high-pressure pump. The main difficulty of such calculations is the fact, that the gaps change their geometry during pumping process. The change of gaps’ geometry can be caused by the motion of the pump’s elements or can be pressure-induced. Both of these factors are included in the article. The paper describes the leakage in: a gap between piston and cylinder block, gap in commutation window, gaps in hydrostatic bearings, the gap between commutation plate and cylinder block. The article includes the methodology and results of FEM and CFD simulation of flow through deformed and undeformed gaps. Basing on the CFD results the mathematical models of such gaps were prepared and added to the article.
Influence of Gd deposition on the oxidation behavior and electrical properties of a layered system consisting of Crofer 22 APU and MnCo2O4 spinel
- Tomasz Brylewski
- Sebastian Molin
- M. Marczyński
- Ł. Mazur
- K. Domaradzki
- O. Kryshtal
- A. Gil
2021 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
In the study, the surface of the Crofer 22APU ferritic steel was modified with gadolinium oxide nanoparticles and a protective-conducting layer consisting of the MnCo2O4 spinel. This system was studied in the context of application in IT-SOFC interconnects. Four types of samples were studied: unmodified steel, steel coated with a manganese-cobalt spinel layer, steel modified with gadolinium oxide nanoparticles, and a system consisting of steel after both modifications. Steel samples with Gd2O3 nanoparticles were obtained via dip-coating, while the spinel coatings were deposited electrophoretically. All samples were oxidized for 1000 and 2260 h in air at 1073 K. Microstructural and oxidation kinetics studies revealed that gadolinium segregation at grain boundaries in the Cr2O3 scale between the steel and the spinel layer reduces the oxidation rate for the steel/coating system, thereby improving the adhesion of the scale to the substrate. The applied modification decreased the chromium evaporation rate and improved the electrical properties of the interconnect material.
Influence of Holes Manufacture Technology on Perforated Plate Aerodynamics
- Joanna Grzelak
- Ryszard Szwaba
2021 Pełny tekst Materials
Transpiration flow is a very important and still open subject in many technical applications. Perforated walls are useful for the purpose of “flow control”, as well as for the cooling of walls and blades (effusive cooling) in gas turbines. We are still not able to include large numbers of holes in the numerical calculations and therefore we need physical models. Problems are related also to the quality of the holes in perforated plates. The present transpiration analysis concerns with experimental investigations of the air flow through perforated plates with microholes of 125 and 300 µm diameters. A good accordance of the results with other experiments, simulations and theory was obtained. The received results very clearly show that technology manufacturing of plate holes influences on their aerodynamic characteristics. It turned out that the quality of the plate microholes using laser technology and, consequently, the shape of the hole, can affect the flow losses. Therefore, this effect was investigated and the flow characteristics in both directions were measured, i.e., for two plate settings.