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Selected anionic and cationic surface active agents determined in river sediments – the Klodnica catchment
PublikacjaSurface active agents (SAAs) are specific compounds that contain hydrophilic/ hydrophobic group in their molecules named as amphiphilic structures. According to charge on the hydrophilic part of surfactants they can be classified into three main groups: anionic, cationic and non-ionic compounds. Due to the amphiphilic structure of SAAs they have specific properties (e.g. ability to adsorption at different surfaces, reduction of...
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Degradation of polycaprolactone modified with TPS or CaCO3 in biotic/abiotic seawater
PublikacjaThis paper is an investigation of the polymer degradation process in two types of seawater (with and without microorganisms) sourced from the Baltic Sea. The chosen polymeric materials were polycaprolactone modified with either thermoplastic starch (PCL/TPS>85%) or calcium carbonate (60% PCL/40% CaCO3) compared directly against unmodified polycaprolactone. All samples were incubated for 28 weeks in seawater with and without microorganisms...
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Coplanar Waveguide-Fed Broadband Microwave Devices with (or without) a Thin Dielectric Substrate for Use in Flexible Electronic Systems
PublikacjaTwo examples of microwave devices, fed by a coplanar waveguide and realized on a thin substrate (or without such a substrate), are employed to investigate the influence of devices’ curvatures and the proximity of different materials on their parameters. To perform the tests, a broadband antenna and a low-pass filter are chosen. A feeding coplanar waveguide is realized on a dielectric material brick attached to an SMA connector...
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FURTHER REMARKS ON THE SURFACE VIS IMPRESSA CAUSED BY A FLUID-SOLID CONTACT
PublikacjaIt is well-known that, nano-mechanics should take into account not only physical phenomena occuring within the bulk but, first of all, the physical phenomena appropriate for a surface of two materials contact. The huge volume density of internal surfaces as well countours lines located within the nanomaterial results in our interest in, apart from classical form of mass, momentum and entropy transport, those modes of transportation...
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Wavepacket of the Universe and its Spreading
PublikacjaWavepackets in quantum mechanics spread and the Universe in cosmology expands. We discuss a formalism where the two effects can be unified. The basic assumption is that the Universe is determined by a unitarily evolving wavepacket defined on space-time. Space-time is static but the Universe is dynamic. Spreading analogous to expansion known from observational cosmology is obtained if one regards time evolution as a dynamical process...
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Influence of Laser Modification on the Surface Character of Biomaterials: Titanium and Its Alloys—A Review
PublikacjaLaser surface modification is a widely available and simple technique that can be applied to different types of materials. It has been shown that by using a laser heat source, reproducible surfaces can be obtained, which is particularly important when developing materials for medical applications. The laser modification of titanium and its alloys is advantageous due to the possibility of controlling selected parameters and properties...
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Application of the expanded clay aggregate in form of granular materials for water treatment
PublikacjaThe paper aimed to evaluate the efficiency of Filtralite MonoMulti compared to the conventional dual-media filter beds comprising silica sand layer covered with anthracite coal. Filtralite media are composed of processed (expanded), highly porous clay products characterized by relatively rough grain surfaces. In order to compare these different media filters in a reliable way, the pilot filter columns operated in parallel, under...
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Simultaneous determination of Na+, K+, Ca2+, Mg2+ and Cl- in unstimulated and stimulated human saliva using all solid state multisensor platform
PublikacjaHuman saliva is one of the body fluids which collection method is relatively simple and non-invasive. The article is dedicated to assess concentration (activity) of Na+, K+, Ca2+, Mg2+ and Cl- in fresh, unstimulated or stimulated human saliva samples using single solid contact ion-selective electrodes with conventional reference electrode and self-made multisensor platform (MP) equipped with ion-selective membranes for Na+, K+,...
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Risk assessment for tram traffic on tramway bridges
PublikacjaMiejski transport szynowy wielu miastach stanowi istotny element systemu transportowego i jest przestrzennie rozwijającym się systemem zapewniającym mieszkańcom codzienną obsługę transportową. Bezpieczeństwo pasażerów transportu szynowego i użytkowników dróg jest jednym z najważniejszych czynników, który należy uwzględnić w trakcie projektowania infrastruktury oraz w ocenie operacyjnej systemu miejskiego transportu tramwajowego....
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SAMOCHÓD SPORTOWY DUOMOTO NAPĘDZANY DWOMA SILNIKAMI SPALINOWYMI
PublikacjaPrzedstawiono zaprojektowany i zbudowany przez zespół czterech dyplomantów Wydziału Mechanicznego Politechniki Gdańskiej samochód sportowy napędzany dwoma silnikami. Jeden z nich umieszczono z przodu pojazdu. Przekazuje on moment obrotowy na koła osi przedniej poprzez zespolony układ napędowy. Drugi silnik, usytuowany ztyłu pojazdu, w identyczny sposób przekazuje moment napędowy na koła osi tylnej....
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Multimodal Surveillance Based Personal Protection System
PublikacjaA novel, multimodal approach for automatic detection of abduction of a protected individual, employing dedicated personal protection device and a city monitoring system is proposed and overviewed. The solution is based on combining four modalities (signals coming from: Bluetooth, fixed and PTZ cameras, thermal camera, acoustic sensors). The Bluetooth signal is used continuously to monitor the protected person presence, and in case...
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Determination of the Bending Properties of Wire Rope Used in Cable Barrier Systems
PublikacjaThis paper presents research on the bending properties of 3 × 7 19-mm wire rope commonly used in road cable barriers. A total of 19 experimental tests were conducted. In addition, two nonlinear 3D numerical models of the wire rope using beam and solid finite elements were developed. Based on these models, four numerical simulations were carried out. The numerical results were validated against the experimental ones and a very good...
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Lighting requirements for pedestrian crossings - positive contrast
PublikacjaFor many years now in Poland there has been a large number of road accidents at pedestrian crossings during night periods [5, 11]. One of the technical solutions that can improve this condition is the use of proper lighting for pedestrian crossings. The designated pedestrian crossing should be visible in different weather conditions and at different times of the day. In case of night vision restrictions use artificial lighting...
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Impact of Intelligent Transport Systems Services on the Level of Safety and Improvement of Traffic Conditions
PublikacjaThe positive effects of the services of Intelligent Transport Systems (ITS) on the level of transport systems operation was confirmed by long-term studies conducted, inter alia, in the USA, Japan and Europe. Benefits resulting from the application of ITS services can be presented through performance indicators. The indicators represent in a numerical or qualitative manner to what extent ITS services can contribute to improving...
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Vehicle detector training with labels derived from background subtraction algorithms in video surveillance
PublikacjaVehicle detection in video from a miniature station- ary closed-circuit television (CCTV) camera is discussed in the paper. The camera provides one of components of the intelligent road sign developed in the project concerning the traffic control with the use of autonomous devices being developed. Modern Convolutional Neural Network (CNN) based detectors need big data input, usually demanding their manual labeling. In the presented...
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Effectiveness of various types of coating materials applied in reinforced concrete exposed to freeze–thaw cycles and chlorides
PublikacjaThis study assesses the durability of coated and uncoated concrete surfaces protected with four Different coating materials: water-soluble (BW), solvent-based (BR), mineral (MI), and epoxy (EP). The durability assessment includes evaluating the absorption rate of water, pull-of adhesion strength, and coating material thickness. Concrete samples were subjected to immersion in regular water and a 7% urea solution, followed by cyclic...
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Effect of TiO2 Concentration on Microstructure and Properties of Composite Cu–Sn–TiO2 Coatings Obtained by Electrodeposition
PublikacjaIn this work, Cu–Sn–TiO2 composite coatings were electrochemically obtained from a sulfate bath containing 0–10 g/L of TiO2 nanoparticles. The effect of TiO2 particles on kinetics of cathodic electrodeposition has been studied by linear sweep voltammetry and chronopotentiometry. As compared to the Cu–Sn alloy, the Cu–Sn–TiO2 composite coatings show rougher surfaces with TiO2 agglomerates embedded in the metal matrix. The highest...
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Artificial neural network based fatigue life assessment of friction stir welding AA2024-T351 aluminum alloy and multi-objective optimization of welding parameters
PublikacjaIn this paper, the fracture behavior and fatigue crack growth rate of the 2024-T351 aluminum alloy has been investigated. At first, the 2024-T351 aluminum alloys have been welded using friction stir welding procedure and the fracture toughness and fatigue crack growth rate of the CT specimens have been studied experimentally based on ASTM standards. After that, in order to predict fatigue crack growth rate and fracture toughness,...
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Estimation of structural stiffness with the use of Particle Swarm Optimization
PublikacjaThe paper presents the theoretical background and four applications examples of the new method for the estimation of support stiffness coefficients of complex structures modelled discretely (e.g. with the use of the Finite Element Model (FEM) method based on the modified Particle Swarm Optimization (PSO) algorithm. In real-life cases, exact values of the supports’ stiffness coefficients may change for various reasons...
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Accelerated large scale test set-up design in natural corrosion marine environment
PublikacjaThe standards for conducting small-scale specimen tests are well developed, but there is a lack of direct guidelines for conducting corrosion tests for large-scale specimens. The objective here is to develop a methodology which may be used in designing an accelerated corrosion test of large-scale structural components subjected to a natural corrosion marine environment. Different factors influencing corrosion degradation of steel...
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Acoustic Sensing Analytics Applied to Speech in Reverberation Conditions
PublikacjaThe paper aims to discuss a case study of sensing analytics and technology in acoustics when applied to reverberation conditions. Reverberation is one of the issues that makes speech in indoor spaces challenging to understand. This problem is particularly critical in large spaces with few absorbing or diffusing surfaces. One of the natural remedies to improve speech intelligibility in such conditions may be achieved through speaking...
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Free Convection Heat Transfer from Horizontal Cylinders
PublikacjaThe results of experimental investigation of free convection heat transfer in a rectangular container are presented. The ability of the commonly accepted correlation equations to reproduce present experimental data was tested as well. It was assumed that the examined geometry fulfils the requirement of no-interaction between heated cylinder and bounded surfaces. In order to check this assumption recently published correlation equations...
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Mn-Co spinel coatings on Crofer 22 APU by electrophoretic deposition: Up scaling, performance in SOFC stack at 850 °C and compositional modifications
PublikacjaCeramic coatings for metallic interconnects play a key role in limiting corrosion and chromium evaporation in solid oxide cells. This study presents the upscaling of the electrophoretic deposition (EPD) technique to process Mn-Co spinels on real-dimension Crofer 22 APU interconnects and the test in a SOFC stack. Area specific resistance of long-term test conducted for 5000 h at 850 °C demonstrated that two-steps sintering has a...
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Nickel-nanodiamond coatings electrodeposited from tartrate electrolyte at ambient temperature
PublikacjaIn this study, nanocrystalline Ni and Ni-diamond coatings were obtained by electrodeposition from tartrate electrolyte at ambient temperature aiming at improving corrosion and wear properties of the material. The created surfaces were investigated with regard to microhardness, adhesion, wear- and corrosion-resistance. The various methods such as atomic force microscopy, scanning electron microscopy, electrochemical impedance spectroscopy...
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Comparison of heat transfer characteristics in surface cooling with boiling microjets of water, ethanol and HFE7100
PublikacjaThe basis of microjet technology is to produce jets which impinge the surface at the stagnation point with a very high kinetic energy. Main objective of this paper was to investigate the physical phenomena occurring on solid surfaces upon impingement of the single microjet in case of three fluids, namely water, ethanol and HFE7100. Intense heat transfer in the impact zone of microjet has been examined and described with precise...
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Characterization and properties of LDPE/(ground tire rubber)/crosslinked butyl rubber blends
PublikacjaIn recent years, interest in used rubber recycling, mainly focusing on the utilization of end-of-life tires, has heightened. This interest, is owing to the activities related to environmental protection and economic factors, which both stimulate companies to reuse the high-quality rubber present in ground rubber scrap. In this study, the application of crosslinked butyl rubber in thermoplastic compositions of low-density polyethylene...
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Analysis of abrasive particle trajectories during single-sided lapping process with driven conditioning ring
PublikacjaIn this paper new kinematics systems were studied for a single lapping process. In order to ensure the constant profile wear of the tool a standard kinematic system can be changed. Lapping is carried out by applying loose abrasive grains between two surfaces and causes a relative motion between them. The result is a finish of multi-directional lay. During process, the mechanism of surface formation are decisively affected by a...
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Effectiveness of various types of coating materials applied in reinforced concrete exposed to freeze–thaw cycles and chlorides
PublikacjaThis study assesses the durability of coated and uncoated concrete surfaces protected with four different coating materials: water-soluble (BW), solvent-based (BR), mineral (MI), and epoxy (EP). The durability assessment includes evaluating the absorption rate of water, pull-off adhesion strength, and coating material thickness. Concrete samples were subjected to immersion in regular water and a 7% urea solution, followed by...
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Conspiracy beliefs about groups benefitting from the COVID-19 pandemic moderate the relationship between fear of COVID-19 and subjective assessment of the efficacy of preventive measures
PublikacjaDrawing on the protective motivation theory and parallel response model, in this cross-sectional, questionnaire-based study (N = 212) performed on the general public (age 18-65), we aimed to test the potential interaction effects of fear of COVID-19 and conspiracy beliefs about groups benefitting from the COVID-19 pandemic in predicting subjective assessment of the efficacy of three COVID-19 preventive measures. The results...
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Application of Stirling Engine Type Alpha Powered by the Recovery Energy on Vessels
PublikacjaThe Stirling engine is a device, in which thermal energy is transformed into mechanical without a contact between the heat carrier, and the working gas closed in the engine. Mentioned feature makes this type of engine very attractive for the use of the recovery energy, taken from other heat devices. One of the potential applications of Stirling engines is the use of thermal energy generated in the ship's engine room for producing...
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A Probe into the Corrosion Behavior of a WE43B Magnesium Alloy in a Simulated Body Fluid using Dynamic Electrochemical Impedance Spectroscopy
PublikacjaWE43B is one of the newest Mg alloys with practical application in biomedical implant technology. This work attempts to scrutinize the corrosion characteristics of WE43B alloy in a simulated body fluid (SBF) at a typical body temperature. The dynamic-electrochemical impedance spectroscopy with the capacity to track changes on surfaces in a dynamic corrosive system is used in combination with other classical techniques namely, linear...
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FDTD Simulations on Disjoint Domains with the Use of Discrete Green's Function Diakoptics
PublikacjaA discrete Green's function (DGF) approach to couple disjoint domains in the finite-difference time-domain (FDTD) grid is developed. In this method, total-field/scattered-field (TFSF) FDTD domains are associated with simulated objects whereas the interaction between them is modeled with the use of the DGF propagator. Hence, source and scatterer are simulated in separate domains and updating of vacuum cells, being of little interest,...
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Consequences of lysine auxotrophy for Candida albicans adherence and biofilm formation
PublikacjaA number of factors are known to be involved in Candida albicans virulence, although biofilm development on the surfaces of indwelling medical devices is considered to promote superficial or systemic disease. Based on previously reported up-regulation of saccharopine and acetyllysine in biofilm cells and activation of the lysine biosynthesis/degradation pathway, we investigated...
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Improvement of Thrust Bearing Calculation Considering the Convectional Heating within the Space between the Pads
PublikacjaA modern thrust bearing tool is used to estimate the behavior of tilting pad thrust bearings not only in the oil film between pad and rotating collar, but also in the space between the pads. The oil flow in the space significantly influences the oil film inlet temperature and the heating of pad and collar. For that reason, it is necessary to define an oil mixing model for the space between the pads. In the bearing tool, the solutions...
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Surface Texture Analysis of Hardened Shafts after Ceramic Ball Burnishing
PublikacjaThis article represents the results of testing the surface condition of shafts manufactured by the burnishing process. The shafts with a hardness of approximately 62 HRC (Rockwell C). were burnished with a ceramic ball (Si3N4), where the force range was controlled by the means of a hydraulic system. The machining process consisted of hard turning shafts with cubic boron nitride (CBN) inserts, followed by burnishing with the use...
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Estakada E2 - kluczowy obiekt Obwodnicy Wałcza
PublikacjaW artykule przedstawiono uwarunkowania i przebieg projektowania estakady E2 z betonu sprężonego w ciągu Obwodnicy Wałcza. Pokazano efekt procesu optymalizacji projektu pierwotnego. Opisano przeprowadzone analizy wynikające z przyjętej technologii nasuwania podłużnego oraz istotne aspekty, które należy poruszyć przy wyborze tej technologii. Zaprezentowano modele numeryczne konstrukcji przęseł i metodę analizy z uwzględnieniem pracy...
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Risks associated with the transportation of hazardous materials on public roads
PublikacjaA significant proportion of the transport of hazardous materials is carried out on public roads. Therefore, the safety of such transport is becoming increasingly important. Every catastrophe involving hazardous materials has a negative impact on direct road users and the surrounding environment, becauses its range is mostly not local. It follows that in the event of such catastrophe, its effects should be minimized. This is possible...
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Development of the New Polish Method for Capacity Analysis of Motorways and Expressways
PublikacjaThe paper presents development of the new Polish method for performing capacity analysis of basic segments of dual carriageway roads (motorways and expressways). The method is based on field traffic surveys conducted at 30 motorway and expressway sites (class A and S roads) in Poland. Traffic flows, composition and travel times were observed in 15-min intervals at each site using ANPR filming method. These data were used to calibrate...
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Localization of sound sources with dual acoustic vector sensor
PublikacjaThe aim of the work is to estimate the position of sound sources. The proposed method uses a setup of two acoustic vector sensors (AVS). The intersection of azimuth rays from each AVS should indicate the position of a source. In practice, the result of position estimation using this method is an area rather than a point. This is a result of inaccuracy of the individual sensors, but more importantly, of the influence of a source...
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Estimation of Vehicle Energy Consumption at Intersections Using Microscopic Traffic Models
PublikacjaThis paper addresses issues related to modeling energy consumption and emissions using microscopic traffic simulations. This paper develops a method in which a traffic model is used to calculate the energy needed to travel through selected types of intersections. This paper focuses on energy consumption and derived values of calculated energy, which can be, for example, carbon dioxide emissions. The authors present a review of...
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Western Front of the City Centre of Gdańsk. An Urban Conservation Study
PublikacjaThe western front of Gdańsk`s city centre is the key fragment of a ring road scheme, which was created at the turn of the 20th century during the great transformation of the city. It was at that time that new streets and squares were delineated on the site of the early modern earthen bastions, which for more than three centuries marked Gdańsk`s border. The new city development was set up in their surroundings. In 1945, Gdańsk was...
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Rospuda - czy wszędzie budować mosty?
PublikacjaStreszczenie - SummaryThe article presents the problem of planning transport system in the areas of high natural and landscape values. Bridges and roads crossing valuable areas undergo Environmental Impact Assessment (EIA) Procedure. This procedure in Poland is often treated only as formal requirement, not as an instrument helping to solve conflicts and to minimise negative environmental and landscape effects. The potential of...
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Effect of ionic liquids on surface and photocatalytic properties of selected semiconducttors
PublikacjaThe 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...
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Graphene-Coated PVDF Membranes: Effects of Multi-Scale Rough Structure on Membrane Distillation Performance
PublikacjaGraphene-coated membranes for membrane distillation have been fabricated by using a wet-filtration approach. Graphene nanoplatelets have been deposited onto PVDF membrane surfaces. Morphology and physicochemical properties have been explored to evaluate the changes in the surface topography and related effects on the membrane performance in water desalination. The membranes have been tested in membrane distillation plants by using...
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Investigation of the Effects of Tool Positioning Factors on Peak Temperature in Dissimilar Friction Stir Welding of AA6061-T6 and AA7075-T6 Aluminum Alloys
PublikacjaAmong the emerging new welding techniques, friction stir welding (FSW) is used frequently for welding high-strength aluminum alloys that are difficult to weld by conventional fusion-welding techniques. This paper investigated the effects of tool-positioning factors on the maximum temperature generated in the dissimilar FSW joint of AA6061-T6 and AA7075-T6 aluminum alloys. Three factors of plunge depth, tool offset, and tilt angle...
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Theoretical studies of fragmentation processes of neutral and ionized furan molecule
PublikacjaThis PhD thesis focuses on the fragmentation mechanism of the furan molecule in the gas phase. The approach taken in this work comprised of three theoretical methodologies considering the dynamical, energetical and entropic aspects of the studied process. First, molecular dynamics simulations were performed. Next, the potential energy surfaces were explored at the DFT/B3LYP level of theory. Finally, a new statistical Microcanonical...
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Mechanism of Li nucleation at graphite anodes and mitigation strategies
PublikacjaLithium metal plating is a critical safety issue in Li-ion cells with graphite anodes, and contributes significantly to ageing, drastically limiting the lifetime and inducing capacity loss. Nonetheless, the nucleation mechanism of metallic Li on graphite anodes is still poorly understood. But in-depth understanding is needed to rationally design mitigation measures. In this work, we conducted FirstPrinciples studies to elucidate...
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Media architecture for post-modern society - new forms of participation
PublikacjaThe article shows the relationship between the characteristics of the post-modern society, and the development of media architecture with the function of interactivity. In this context, the duality of the features of post-modern society was emphasized: taking into account its location between creativity and consumerism, as well as on the border between the real and virtual word. The development of media architecture has been linked...
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Plasma-Based Deposition and Processing Techniques for Optical Fiber Sensing
PublikacjaPlasma-based techniques are widely applied for well-controlled deposition, etching or surface functionalization of a number of materials. It is difficult to imagine fabrication of novel microelectronic and optoelectronic devices without using plasma-enhanced deposition of thin films, their selective etching or functionalization of their surfaces for subsequent selective binding of chemical or biological molecules. Depending on...
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Water absorption and blistering of glass fibre-reinforced polymer marine laminates with nanoparticle-modified coatings
PublikacjaMacro and microstructural damage was studied in typical glass fibre-reinforced polymer laminates with two types of coating systems – (a) isophtalic gel coat: pure or mixed with SiO2 nanoparticles 5 wt% (5%N) or 10 wt% (10%N) and (b) a two-layer coating system: urethane-modified vinyl ester-based gel coat and additional polyester barrier coat layer. Accelerated tests were performed at 50C for 50 days for specimens with nanoparticle-modified...