2022 - Publications Repository - Gdańsk University of Technology

Show publications from the year

Publications from the year 2022

Show all

Early Stages of RNA-Mediated Conversion of Human Prions
- Emilia Lubecka
- Ulrich H. E. Hansmann
2022 Full text JOURNAL OF PHYSICAL CHEMISTRY B
Prion diseases are characterized by the conversion of prion proteins from a PrPC fold into a disease-causing PrPSC form that is self-replicating. A possible agent to trigger this conversion is polyadenosine RNA, but both mechanism and pathways of the conversion are poorly understood. Using coarse-grained molecular dynamic simulations we study the time evolution of PrPC over 600 μs. We find that both the D178N mutation and interacting with polyadenosine RNA reduce the helicity of the protein and encourage formation of segments with strand-like motifs. We conjecture that these transient β-strands nucleate the conversion of the protein to the scrapie conformation PrPSC.
Edge-Computing based Secure E-learning Platforms
- Sameer Ahmad Bhat
- Dalia Alyahya
- Muneer Ahmad Dar
- Saadiya Shah
2022 Full text
Implementation of Information and Communication Technologies (ICT) in E-Learning environments have brought up dramatic changes in the current educational sector. Distance learning, online learning, and networked learning are few examples that promote educational interaction between students, lecturers and learning communities. Although being an efficient form of real learning resource, online electronic resources are subject to threats and vulnerabilities on the internet. Authentication, access and storage of data is a major concern among many organizations implementing E-learning platforms. This study provides a literature review of past five-year research studies, and proposes Edge-computing based solution to the currently existing authentication and data access problems that prevail in the current E-learning management systems using cloud services for data storage. The study guides researchers towards enabling Edge-computing based E-learning platforms to support low power computing devices running Elliptic Curve Cryptography for secure access and authentication.
Education Towards The Use Of BIM On The Example Of Polish Universities
- Waldemar Kosiedowski
- Marek Wirkus
2022 Full text Organization Technology and Management in Construction
BIM (Building Information Modeling) has been one of the rapidly developing fields of digital techniques supporting the realization of construction projects in recent years. Further development, and especially the use of these techniques, depends to a large extent on the qualifications of young construction engineers who start their professional careers in this field. The article attempts to synthetically list and compare subjects, specializations or fields related to teaching about the BIM methodology in Polish universities curricula. The aim of the study is to present the key factors and differences in the approach to education in this field and on this basis an attempt to formulate conclusions regarding the optimal way of conducting the didactic process in the field of BIM education. The subject of the research were BIM education offers at Polish universities at various levels of education. The places where education occur at Polish universities were identified and the time of implementing BIM technology teaching was compared. The levels, paths, graduate profile, educational programs, the presence of practical elements, the achieved results as well as the types, forms and modes of conducting classes at individual universities were analyzed. The analysis was conducted on the basis of information available on the Internet about the faculties and programs of education of individual universities, supplemented with additional information obtained in e-mail correspondence and conducted by telephone interviews. As a result of the analyzes, the key guidelines for conducting education at the university level were proposed.
Educational Dataset of Handheld Doppler Blood Flow Recordings
- Tomasz Kocejko
2022 Full text
Vital signals registration plays a significant role in biomedical engineering and education process. Well acquired data allow future engineers to observe certain physical phenomena as well learn how to correctly process and interpret the data. This dataset was designed for students to learn about Doppler phenomena and to demonstrate correctly and incorrectly acquired signals as well as the basic methods of signal processing. This paper presents three corresponding datasets consisting of 21 recording of signals acquired from the neck area with USG gel applied and 21 distorted recordings acquired without gel.
EE-ISAC—Practical Cybersecurity Solution for the Energy Sector
- Tania Wallis
- Rafał Leszczyna
2022 Full text ENERGIES
A recent survey of cybersecurity assessment methods proposed by the scientific community revealed that their practical adoption constitutes a great challenge. Further research that aimed at identifying the reasons for that situation demonstrated that several factors influence the applicability, including the documentation level of detail, the availability of supporting tools, and the continuity of support. This paper presents the European Energy Information Sharing and Analysis Centre (EE-ISAC)—a cybersecurity platform for the energy sector that has been adopted by multiple organisations. The platform facilitates sharing information about cybersecurity incidents, countermeasures, and assessment results. Prospectively, it is envisaged to be integrated with the threat intelligence platform that enables real-time situational awareness. By considering both fault and attack scenarios together, threat awareness can be mapped onto operational contexts to prioritise decisions and responses. This paper analyses EE-ISAC’s approach based on the conceptual applicability framework developed during the research, to improve the applicability and usefulness of this platform for energy sector participants and to identify areas that require further development.
Effect of asymmetric fluid flow distribution on flow boiling in a microchannel heat sink – An experimental investigation
- Kumar Ritunesh
- Gurjeet Singh
- Dariusz Mikielewicz
2022 Full text APPLIED THERMAL ENGINEERING
Flow boiling in microchannels is emerging as an exclusive cooling solution for miniaturized high-power electronic devices alongside having other high heat flux applications. Size miniaturization at microscale strangely increases heat transfer performance as well as flow boiling instabilities. Many flow boiling instabilities are interrelated and result from imperfect hydrodynamic conditions. One of such problems is flow maldistribution among parallel channels of a microchannel heat sink. Very limited studies have dedicatedly investigated the negative effects of flow aldistribution on the boiling process in microchannels. A microchannel heat sink with twenty-five rectangular microchannels (width × height × length = 0.45 × 0.725 × 25 mm) made on a copper block base of 25 × 25 × 85 mm using wire electrical discharge machining under an I-type flow configuration is investigated for that purpose. Flow boiling patterns of central and side microchannels as well as the temperature profile of central and side microchannels are recorded. The boiling process always incepts in side microchannels and rapidly converts into a periodic flow reversal up to the inlet manifold, whereas weak, stable, bubbly flow and single-phase liquid flow are observed in the neighboring and central microchannels, respectively. Furthermore, with the increase of heat flux, flow boiling intensity increases and more parallel microchannels start experiencing rapid bubble growth; consequently, the intensity of flow reversal in side channels also increases. At high heat fluxes, the vapor backflow of side microchannels reaches the central microchannel and blocks the flow through it, named mirage flow confinement. Boiling in the central channel aggravates under the influence of the mirage flow reversal processes. Temperature non-uniformity across the microchannel heat sink increases with the increase of heat flux and mass flux caused by the early appearance of a partial dryout of side channels and the escalation of the flow distribution asymmetry. Whereas, better temperature distribution is observed at higher inlet fluid temperatures.
Effect of Chitosan Solution on Low-Cohesive Soil’s Shear Modulus G Determined through Resonant Column and Torsional Shearing Tests
- Marta Bocheńska
- Marcin Bujko
- Ireneusz Dyka
- Piotr E. Srokosz
- Rafał Ossowski
2022 Full text Applied Sciences-Basel
In this study the effect of using a biopolymer soil stabilizer on soil stiffness characteristics was investigated. Chitosan is a bio-waste material that is obtained by chemical treatment of chitin (a chemical component of fungi or crustaceans’ shells). Using chitosan solution as a soil stabilizer is based on the assumption that the biopolymer forms temporary bonds with soil particles. What is important is that these bonds are biodegradable, so the product does not leave any harmful waste and has high eco-compatibility. The biopolymer itself is a by-product of many industrial chemical processes, so its application is compliant with the goals of sustainable geotechnical engineering. The effect of chitosan on soil shear strength, permeability or surface erosion has already been investigated in several different studies. In this study specimens of low-cohesive soil stabilized with two different chitosan solutions were subject to cyclic loading (torsional shearing test) and dynamic loading (resonant column) to obtain soil shear modulus G as a function of strain values. It has been shown that chitosan solution added to medium-grained materials improves their shear modulus G substantially (up to 3 times) even for relatively low chitosan concentration solutions (1.5 g of chitosan per 1 kg of dry silica sand). The results obtained in this study and the known chitosan properties suggest that chitosan solutions can be a very effective and eco-friendly short-term stabilizer for temporary geotechnical structures, e.g., working platforms.
Effect of convection and microwave heating on the retention of bioactive components in human milk
- Dorota Martysiak-Żurowska
- Edyta Malinowska-Pańczyk
- Małgorzata Orzołek
- Bogumiła Kiełbratowska
- Elena Sinkiewicz-Darol
2022 Full text FOOD CHEMISTRY
Bioactive substances are very important components of human milk (HM), especially for premature newborns. The effects of convection (CH) and microwave heating (MWH) at 62.5 and 66 °C, on the level of selected bioactive components of HM: lysozyme (LZ), lactoferrin (LF), secretory immunoglobulin A (sIgA), basal lipase (BL), cytokine TGF-2, vitamin C and total antioxidant capacity (TAC) was compared. Regardless of the used heating methods the TAC of HM, determined by TEAC and ORAC-FL assay, proved to be insensitive to temperature pasteurization, in contrary to BL. MWH in the conditions of 62.5 for 5 min and 66 °C for 3 min are ensuring microbiological safety with a higher retention of most of the tested active HM proteins compared to CH. Only in the case of LZ the MWH had a more degradative effect on its concentration. Controlled conditions of MWH preserve the bioactive components of the HM better than CH.
Effect of elliptical defect orientation on the durability of specimens subjected to cyclic bending
- Zbigniew Marciniak
- Ricardo Branco
- Rui F. Martins
- Dariusz Rozumek
- Wojciech Macek
2022 Full text Procedia Structural Integrity
This work presents the effect of elliptical defects orientation on the durability of specimens made of C45 steel. Three kinds of specimens with elliptical defects in the form of a one-sided notch oriented at different angles 45, 60, and 90 degrees were subjected to cyclic bending (R=-1). The stress state analysis was performed using local and non-local methods to determine an equivalent amplitude of stress, and then the results were compared with those obtained for smooth specimens.
Effect of Ion and Binding Site on the Conformation of Chosen Glycosaminoglycans at the Albumin Surface
- Piotr Sionkowski
- Piotr Bełdowski
- Natalia Kruszewska
- Piotr Weber
- Beata Marciniak
- Krzysztof Domino
2022 Full text ENTROPY
Albumin is one of the major components of synovial fluid. Due to its negative surface charge, it plays an essential role in many physiological processes, including the ability to form molecular complexes. In addition, glycosaminoglycans such as hyaluronic acid and chondroitin sulfate are crucial components of synovial fluid involved in the boundary lubrication regime. This study presents the influence of Na+, Mg2+ and Ca2+ ions on human serum albumin–hyaluronan/chondroitin-6- sulfate interactions examined using molecular docking followed by molecular dynamics simulations. We analyze chosen glycosaminoglycans binding by employing a conformational entropy approach. In addition, several protein–polymer complexes have been studied to check how the binding site and presence of ions influence affinity. The presence of divalent cations contributes to the decrease of conformational entropy near carboxyl and sulfate groups. This observation can indicate the higher affinity between glycosaminoglycans and albumin. Moreover, domains IIIA and IIIB of albumin have the highest affinity as those are two domains that show a positive net charge that allows for binding with negatively charged glycosaminoglycans. Finally, in discussion, we suggest some research path to find particular features that would carry information about the dynamics of the particular type of polymers or ions
Effect of ionic liquids on surface and photocatalytic properties of selected semiconducttors
- Anna Pancielejko
2022
The main aim of this doctoral dissertation was to explain the role of ionic liquids in shaping the morphology of selected semiconductors, thereby enhancing the photocatalytic activity. In order to achieve this goal, the following research steps were taken: (i) developing synthesis methods of selected semiconductors, with particular emphasis on the electrochemical oxidation method; (ii) understanding the influence of the selected ionic liquids introduced into the reaction environment on the surface and photocatalytic properties of selected photocatalysts; (iii) explaining the role of ionic liquids in the mechanism of the photocatalytic reaction; (iv) correlating the morphological parameters and structural/surface properties with the photocatalytic activity of the obtained nanomaterials. The doctoral dissertation discusses the results of two research areas: (i) TiO2 nanotubes obtained in the presence of [EAN][NO3] or [BPy][Cl] with added traditional organic electrolyte; (ii) thin film BiOBr/Bi2WO6 heterojunction prepared via a two-step approach involving electrochemical oxidation and hydrothermal transformation in the presence of [BPy][Br]. The experimental results show that by using ionic liquids during the synthesis of semiconductors, it is possible to control their surfaces, and thus, photocatalytic properties.
Effect of microwave and convection heating on selected nutrients of human milk
- Dorota Martysiak-Żurowska
- Edyta Malinowska-Pańczyk
- Małgorzata Orzołek
- Barbara Kusznierewicz
- Bogumiła Kiełbratowska
2022 Full text FOOD CHEMISTRY
The aim of this study was to determine the influence of the microwave heating method (MWH) on selected determinants of the nutritional value of human milk (HM) and compare to the effect exerted by the standard convection heating (CH) method, including holder pasteurization (HoP). It was showed that using MWH under conditions assumed to ensure microbiological safety, changes in the level of the nutrients were not observed. In these conditions concentration of fatty acids (FAs), lipid peroxides (LP) and α-lactalbumin (α-La) were on a similar level as in raw milk, and furosine was not formed. MWH treatment of HM led to slight increase in the malonaldehyde (MDA) and protein carbonyls (PC) content. However, MDA content in HM as a result of MWH was lower than after application CH.
Effect of Nb and Al on in vitro dissolution behavior and structure of Na2O-MgO CaO-P2O5 glasses
- Natalia Wójcik
- Stefania Wolff
- Jakub Karczewski
- Małgorzata Rutkowska
- Sharafat Ali
2022 Full text JOURNAL OF NON-CRYSTALLINE SOLIDS
In vitro dissolution, structure, and thermal properties of the glass series Na2O-MgOsingle bondCaOsingle bondNb2O5 -Al2O3-P2O5 were studied. The dissolution behavior in phosphate-buffered saline (PBS) confirmed the potential bioactive properties of tested glasses. The dissolution process was found to depend on the Al, Nb, and Mg contents. Al, respectively, suppresses the Nb and accelerates the Mg release process from the glasses. Moreover, Al stays highly bonded in the phosphate network during 14 days of immersion. In all glasses, the phosphate network was found to be highly disrupted and built mostly of Q1 units. Al and Mg addition decreases the polymerization of the glass network. The Nb addition effect was found to be the opposite. Thermal properties were correlated mostly with the Nb and Al contents. However, the fragility index of glasses increases with the content of P and Al.
Effect of Particle Size of Fly Ash Microspheres (FAMs) on the Selected Properties of Concrete
- Elżbieta Haustein
- Aleksandra Kuryłowicz-Cudowska
2022 Full text Minerals
This paper presents the investigations of selected properties of concrete containing two fractions of fly ash microspheres (FAMs) with grain size up to 200 μm and up to 500 μm. Concrete mixtures with ordinary Portland cement and three substitution rates of cement by FAMs, 1.3%, 2.0%, and 2.6%, were investigated. For all concrete mixes, the constant water–binder ratio (w/b) equal to 0.50 was used. The research program included the determination of chemical composition, particle size distribution, and pozzolanic activity of FAMs. The analysis showed that the microspheres consist of three main elements: silicon, aluminum, and iron, whose oxides constitute about 89% of the material. The total content of air pores, measured in concrete at 28 days, ranges from 1.3 to 3.1% for the grain sizes below 200 μm and from 1.4% to 3.9% for the grain sizes up to 500 μm. The FAMs with a particle diameter < 200 μm have a relatively high level of activity pozzolanic at 28 days. The SEM analysis proved that the use of microspheres reduces gaps and increases the CSH phase. The compression test showed that the addition of fly ash microspheres with grain size below 200 μm increases long‐term concrete strength.
Effect of Porosity on the Thermo-Mechanical Behavior of Friction-Stir-Welded Spark-Plasma-Sintered Aluminum Matrix Composites with Bimodal Micro- and Nano-Sized Reinforcing Al2O3 Particles
- Behzad Sadeghi
- Behzad Sadeghian
- Aboozar Taherizadeh
- Aleksandra Laska
- Pasquale Cavaliere
- Arun Gopinathan
2022 Full text Metals
The thermo-mechanical behavior of nanosized Al2O3 particles reinforcing aluminum was analyzed in the present paper. The material was prepared by spark plasma sintering and friction stir welding. The thermal stresses affecting the composite behavior during welding were modeled through COMSOL MultiPhysics, and the results were validated by the analyses of the composites’ mechanical properties. The spark-plasma-sintered materials presented limited porosity, which was taken into account during the modeling phase. Both model and experiments revealed that higher heat input is related to better material mixing during welding and sound mechanical properties. Thermal stresses lead to residual stresses close to 300 MPa in the thermo-mechanically affected zone for processing conditions of 1900 RPM and 37 mm/min. This leads to an increase in hardness up to 72 HV.
EFFECT OF PRESS DRYING ON DIMENSION STABILITY AND DENSITY OF BEECH WOOD,
- Ivan Klement
- Peter Vilkovský
- Tatiana Vilkovská
- Jacek Barański
- Aleksandra Suchta
2022 Full text Trieskove a Beztrieskove Obrabanie Dreva
Timber is traditionally dried in kilns by processes that often take several days or weeks to complete. At present, it is possible to apply several methods of rapid drying of timber, including, for example, press drying. This research is based on the use of this process. Drying was performed using the heating plates with a temperature of 160 °C. Three pressures were compared in the research 1.0 MPa, 1.4 MPa, and 1.8 MPa. The density of the samples remarkably increased during press drying. The pressure of the heating plates had a substantial effect. The difference in the average density between the pressure of 1.0 MPa and 1.8 MPa was more than 92 kg.m-3 . A larger increase in density was discovered for radial samples (ranging between +95.31 to+110.85). The difference in the change of sample thickness was larger in the case of the tangential samples. For both groups of samples (radial, tangential) and all ressures, the samples dried by the contact method were more stable during swelling than the samples dried by the convection method.
Effect of Processing Parameters on Strength and Corrosion Resistance of Friction Stir-Welded AA6082
- Aleksandra Laska
- Marek Szkodo
- Damian Koszelow
- Pasquale Cavaliere
2022 Full text Metals
The friction stir welding method is increasingly attracting interest in the railway sector due to its environmental friendliness, low cost, and ease of producing high-quality joints. Using aluminum alloys reduces the weight of structures, increasing their payload and reducing fuel consumption and running costs. The following paper presents studies on the microstructure, strength, and corrosion resistance of AA6082 aluminum alloy sheets joined via friction stir welding. The sheets were joined by employing two different traverse speeds (200 and 250 mm/min), two different rotational speeds (1000 and 1250 rpm), and two different tool tilt angles (0◦ and 2◦ ). It was observed that the use of the inclined tool provides finer microstructure in the nugget zone, higher value of microhardness, and better corrosion resistance, compared to the tilt angle equal to 0◦ . By increasing the value of revolutionary pitch, finer grains are observed in the nugget zone and the measured hardness is higher. It was also observed that the change in process parameters strongly influences the radius of the nugget zone and the potentiodynamic properties of the friction stir-welded material. The joints produced with the tool tilt angle equal to 2◦ , the tool traverse speed of 200 mm/min, and its rotational speed of 1250 rpm revealed the highest hardness in the nugget zone (about 92% of the base material). Moreover, the finest grain size in the nugget with the average value of 9.8 ± 1.5 µm was found. The lowest corrosion current density equal to 16.029 µA cm−2 was noted for the sample with the highest strength, which also provides its good corrosion resistance.
Effect of slag coal ash and foamed glass on the mechanical properties of two-stage concrete
- Hakim S. Abdelgader
- Marzena Kurpińska
- Mugahed Amran
2022 Materials Today: Proceedings
Two-stage concrete (TSC) is known by various names such as colcrete, Polcrete, preplaced aggregate concrete and prepacked concrete. It is different from traditional concrete in two fundamental ways, namely method of construction and mix proportion. Two-stage concrete (TSC) is defined as firstly, coarse aggregates are placed into the formwork and grout is applied to fill in the between coarse aggregate particles voids. Secondly, the percentage of coarse aggregates in the mix proportion of TSC is higher than that in normal concrete. The typical value is about 60% as compared with 40% in traditional concrete. As coarse aggregates are preplaced first, they can occupy up to 60–70% of the total volume. As coarse aggregates are not involved in the mixing process, TSC is environmentally friendly with lesser consumption of energy. With a higher content of aggregates, TSC reduces the use of cement by 20–30% and may minimize the temperature rise. Engineering properties of TSC, including its stress–strain relationship, is mainly governed by the properties of coarse aggregates as stress is transferred from the skeleton of aggregates to hardened grout. Main advantages of TSC include a higher volume of coarse aggregates and the ability to use larger size coarse aggregates. The latter also reduces the cost of crushing. TSC has beneficial properties such as low drying shrinkage, high bonding strength, high modulus of elasticity, and excellent durability. The method of TSC has proved particularly useful in a number of applications like underwater construction, and masonry repair, where placement by conventional methods is extremely difficult. The method is also applicable in case of massive concrete where low heat of hydration is required. It is studied the feasibility of casting two stage concrete with 100% steel slag as coarse aggregate. In term of formulation, to adopt two stage concreting method we could minimize the risk of concrete bleeding and segregation due to high water absorption and quite high density of slag aggregate. The effect of slag coal ash and foamed glass on the mechanical properties of two-stage concrete has rarely been reported. Thus, the development of an eco-efficient alkali-activated grout for two-stage concrete is a new research topic that has no robust results to draw solid conclusions and it should blaze the track towards a cleaner production of building materials with outstanding sustainability.
Effect of temperature change on refractive index of an egg white and yolk: a preliminary study
- Patryk Sokołowski
2022 Full text Photonics Letters of Poland
In this article, the refractive index of an egg white and yolk depending on temperature in range 30 - 47 °C over 1550 nm was determined. The measurement head was constructed as fiber optic Fabry-Perot interferometer with interference between polished fiber end-face and aluminum weighing dish. The measurement setup has been made of an optical spectrum analyzer, a superluminescent diode with a central wevelength of 1550 nm, 2:1 fiber coupler and heat plate.
Effect of the ionic liquids on extraction of aromatic and sulfur compounds from the model petrochemical stream
- Wiśniewski Piotr
- Konrad Bołoz
- Anna Wiśniewska
- Zbigniew Dąbrowski
- Dominika Kubica
- Justyna Łuczak
- Urszula Domańska
2022 FLUID PHASE EQUILIBRIA
Suitability of a imidazolium ionic liquids (ILs) as solvents in dearomatization and desulfurization in the ternary systems and in a model multicomponent systems has been analyzed. With this aim, ternary liquid-liquid phase equilibrium data (LLE) have been obtained for ternary mixtures of {IL + benzene, or toluene, or thiophene, or 2-butanethiol + hexane}, or {IL + benzene + 2-methylpentane} at T = 298.15 K and ambient pressure, as well as for multicomponent systems –model petrochemical stream {IL + model stream (benzene, toluene, thiophene, 2-butanethiol) + hexane} at T = 303.15 K and ambient pres- sure. Two ILs have been studied: 1-ethyl-3-methylimidazolium thiocyanate, [EMIM][SCN] and 1-ethyl- 3-methylimidazolium dicyanamide, [EMIM][DCA]. The values of solute distribution ratio and selectivity have been evaluated. It has been shown that ILs investigated in this work are able to extract sulfur com- pounds in preference to benzene and toluene. The solute distribution ratios for both ILs are similar. The selectivity of the aromatic and sulfur compounds are higher for [EMIM][SCN]. The best distribution ratio ( > 1.98) and selectivity ( > 242) was observed for thiophene extracted from the model stream 1:1.