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Interfacially modified LDPE/GTR composites with non-polar elastomers: From microstructure to macro-behavior
PublikacjaThis paper provides some new insights into the mechanism of interaction and modifications in thermoplastic composites based on low density polyethylene (LDPE), ground tire rubber (GTR) and non-polar elastomer. The composites were prepared using a co-rotating twin-screw extruder at variable LDPE/GTR ratio and constant elastomer content. Two types of commercial elastomer were applied: styrene-butadiene-styrene (SBS) block copolymers (Kraton®)...
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Natural convective heat transfer from isothermalconic
PublikacjaTheoretical considerations on convective heat transfer from isothermal upward conicalsurfaces have been presented. The physical model of this phenomenon consists of an isothermalcone of inclination angle (φ) between the cone generating line (X) and the radius (R) of the cone base. The angle is a parameter of conical surface which varied from (φ = 0−circular horizontal plate) to (φ = π/2—vertical cylinder) . Onthe basis of Navier–Stokes...
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GPR investigation of the strengthening system of a historic masonry tower
PublikacjaIn this paper the condition assessment of the strengthening system of a masonry tower was carried out by the GPR method. The study provided unique experimental data acquired during measurements of the reinforced concrete frame embedded in masonry walls. Conducted numerical and experimental investigations were focused on the phenomenon of the diffraction-refraction scattering of the electromagnetic energy. A hyperbola resulting...
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Peripheral industrial NUTS 3 sub-regions in the European Union – identification and typology
PublikacjaA common phenomenon of development is the big difference in its levels, especially between metropolitan and non-metropolitan areas. Non-metropolitan areas are also very different. In some of them, industry plays a big role. European Union’s NUTS 3 non-metropolitan low developed sub-regions, whose gross domestic product per capita in 2011 was below 75% of the EU average, were the subject of research. It is based on the data and...
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Barcelona - from the province to Metropolis.The cogent strategy of branding the city
PublikacjaThe phenomenon of rebranding Barcelona's image, called the Barcelona effect or 'Barcelona Model', is exampled as one of the most spectacular transformations of the city perception in the last decade. Why has Barcelona been successful? Is it the effect of the recently intensified revitalization practice, or has the city of Barcelona built its brand market value for years? The aim of the research is to name these transition...
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Assessment of Supercapacitor’s Quality by Means of Low Frequency Noise
PublikacjaLow frequency noise is a well-known tool for quality and reliability assessment of electronic devices. This phenomenon is observed in different electrochemical devices as well (e.g., smart windows, electrochemical corrosion processes). Thus, we can assume that the same tool can be used to asses quality of supercapacitors. Their quality is usually determined only by capacitance and/or equivalent series resistance (ESR), or impedance....
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Tax Evasion, Tax Morale, and Trade Regulations: Company-Level Evidence from Poland
PublikacjaObjective: To investigate the determinants of the phenomenon of evading taxes among polish entrepreneurs. In particular, I examine such factors as tax administration satisfaction, tax morale, tax burden, and the influence of trade regulations. Research Design & Methods: A survey study conducted in 2017 in Poland among 454 enterprises. I used the zero-inflated negative binomial modelling technique to examine the impact of factors...
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A note on the applications of artificial intelligence in the hospitality industry: preliminary results of a survey
PublikacjaIntelligent technologies are widely implemented in different areas of modern society but specific approaches should be applied in services. Basic relationships refer to supporting customers and people responsible for services offering for these customers. The aim of the paper is to analyze and evaluate the state-of-the art of artificial intelligence (AI) applications in the hospitality industry. Our findings show that the major...
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Processing, physico-mechanical and thermal properties of reclaimed GTR and NBR/reclaimed GTR blends as function of various additives
PublikacjaIn this work, ground tire rubber (GTR) was mechano-chemically reclaimed in the presence of bitumen and various additives. During studies three types of processing and curing additives: (i) peptizer P300; (ii) vulcanization accelerator tetramethylthiuram disulfide (TMTD) and (iii) organic peroxide di(2-tert-butyl-peroxyisopropyl)benzene (BIB1) were applied to enhance reclaiming of GTR. Reclaiming process was evaluated by oscillating...
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Aerodynamic Shape Optimization for Delaying Dynamic Stall of Airfoils by Regression Kriging
PublikacjaThe phenomenon of dynamic stall produce adverse aerodynamic loading which can adversely affect the structural strength and life of aerodynamic systems. Aerodynamic shape optimization (ASO) provides an effective approach for delaying and mitigating dynamic stall characteristics without the addition of auxiliary system. ASO, however, requires multiple evaluations time-consuming computational fluid dynamics models. Metamodel-based...
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Coupling between Blood Pressure and Subarachnoid Space Width Oscillations during Slow Breathing
PublikacjaThe precise mechanisms connecting the cardiovascular system and the cerebrospinal fluid (CSF) are not well understood in detail. This paper investigates the couplings between the cardiac and respiratory components, as extracted from blood pressure (BP) signals and oscillations of the subarachnoid space width (SAS), collected during slow ventilation and ventilation against inspiration resistance. The experiment was performed on...
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State Interventionism in Tax System - Example of Action in a COVID-19 Crisis
PublikacjaThe following article presents and classifies changes in tax systems of selected countries as well as counts them as the response to the emergence of the crisis caused by the COVID-19 pandemic. Such actions were undertaken the context of state interventionism in the tax system. In order to achieve the objective of presenting the state interventionism in the context of tax rates, an analysis of the literature on the phenomenon described,...
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Data-driven, probabilistic model for attainable speed for ships approaching Gdańsk harbour
PublikacjaThe growing demand for maritime transportation leads to increased traffic in ports. From this arises the need to observe the consequences of the specific speed ships reach when approaching seaports. However, usually the analyzed cases refer only to the statistical evaluation of the studied phenomenon or to the empirical modelling, ignoring the mutual influence of variables such as ship type, length or weather conditions. In this...
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Toward an understanding of occupational burnout among employees with autism – the Job Demands‑Resources theory perspective
PublikacjaThis article aims to gain insight into the phenomenon of occupational burnout among employees with autism based on the theoretical framework of the Job Demands-Resources theory and the literature on employees with autism in the workplace. Firstly, we argue that although the resources and demands of the neurotypical and neurodivergent employees might be different, the theoretical mechanism of occupational burnout formation remains...
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Detection of anomalies in bee colony using transitioning state and contrastive autoencoders
PublikacjaHoneybees plays vital role for the environmental sustainability and overall agricultural economy. Assisting bee colonies within their proper functioning brings the attention of researchers around the world. Electronics systems and machine learning algorithms are being developed for classifying specific undesirable bee behaviors in order to alert about upcoming substantial losses. However, classifiers could be impaired when used...
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High-quality Experiment Dedicated to microGravity Exploration, Heat Flow and Oscillation Measurement from Gdańsk
PublikacjaIn this paper we propose HEDGEHOG (High-quality Experiment Dedicated to microGravity Exploration, Heat flow and Oscillation measurement from Gdańsk) REXUS experiment to investigate vibrational and heat flow phenomena during the whole (ascent, microgravity phase, descent and recovery) flight of a sounding rocket. First, a proposed system of cantilever beams is discussed to study dynamic behaviour of dummy payload. Dimensioning has...
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Analysis and Comparison of Safety of Children and Adult Passenger in Car Based on Crash Tests Results
PublikacjaMost important features of the child seat were presented. There was made analysis of selected dynamic loads acting on mannequins heads during a collision. Comparison of loads acting on the kid in a child seat and the other passengers in a car is presented. In analysis of the results particular attention has been paid on the children's secure in a car. The phenomena of collision child's occipital bone with seat backrest was described....
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A current-controlled FET
PublikacjaA novel semiconductor device, viz., Horizontally-Split-Drain Current-Controlled Field-Effect Transistor (HSDCCFET) with two control electrodes is proposed in this works. For the sake of brevity, the device can be called a CCFET. Operating principle of the proposed transistor is based on one of the galvanomagnetic phenomena, the Biot-Savart-Laplace law and a Gradual Channel Detachment Effect (GCDE). The transistor is dedicated...
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Ultrawideband transmission in physical channels: a broadband interference view
PublikacjaThe superposition of multipath components (MPC) of an emitted wave, formed by reflections from limiting surfaces and obstacles in the propagation area, strongly affects communication signals. In the case of modern wideband systems, the effect should be seen as a broadband counterpart of classical interference which is the cause of fading in narrowband systems. This paper shows that in wideband communications, the time- and frequency-domain...
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Hybrid model of geared rotor system
PublikacjaIn the paper a hybrid model of a geared multirotor system has been developed. The model is obtained by application of both the modal decomposition methodology and the spatial discretization method. Reduced modal model was constructed for the system without gyroscopic and damping effects. The gyroscopic interaction, damping and other phenomena which are difficult to include in the modal approach were modeled by application of simply...
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Tracking Fluorescent Dye Dispersion from an Unmanned Aerial Vehicle
PublikacjaCommercial unmanned aerial vehicles continue to gain popularity and their use for collecting image data and recording new phenomena is becoming more frequent. This study presents an effective method for measuring the concentration of fluorescent dyes (fluorescein and Rhodamine WT) for the purpose of providing a mathematical dispersion model. Image data obtained using a typical visible-light camera was used to measure the concentration...
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The effect of cable duct diameter on the ampacity of high-voltage power cables
PublikacjaThe ampacity of power cables depends, among others, on the conditions of heat dissipation from the cable to the environment. Cables are usually laid directly in the ground, but in some sections, they may be placed in ducts, which adversely affects the ampacity of the cable line. The paper presents heat transfer phenomena for cables installed in pipe-type ducts filled with air. The effect of cable duct diameter on this ampacity...
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Preliminary studies on the effect of feed speed on the colour change of wood
PublikacjaThis paper presents the results of preliminary analyses of the effect of cutting parameters on changes in the colour of wood. Beech wood cut with use circular saw was analysed. The cutting parameter tested was the feed speed, represented by the feed per tooth. Sawing processes with different feed per tooth ranging from 0.0008 mm to 0.09 mm were analysed. It was observed that over the entire range of feed rate per tooth analysed,...
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Analysis of the structure of the atomized fuel spray with marine diesel engine injector in the early stage of injection
PublikacjaThis paper presents the results of the experimental research of the atomized fuel spray with the marine diesel engine injector in the constant volume chamber. The specificity of the phenomena occurring in the marine engine cylinder was the reason to use the optical visualisation method in the studies – the Mie scattering technique. This work presents an analysis of the influence of different geometry of outlet orifice and opening...
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High Frequency Conducted Emission in AC Motor Drives Fed By Frequency Converters: Sources and Propagation Paths
PublikacjaProvides a concise and thorough reference for designing electrical and electronic systems that employ adjustable speed drives Electrical and electronic systems that employ adjustable speed drives are being increasingly used in present-day automation applications. They are considered by many application engineers as one of the most interfering components, especially in a contemporarily faced industrial environment. This book fills...
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Guided waves for nondestructive diagnostics of embedded waveguides
PublikacjaThe thesis concentrates on comprehensive theoretical, numerical and experimental analysis of guided wave propagation in bars embedded in concrete or mortar. The investigations are focused on a particular type of objects representing a laboratory model of a ground anchor. Complex description of wave propagation phenomena in partially embedded bars is given and its application in...
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Marine and Cosmic Inspirations for AI Algorithms
PublikacjaArtificial Intelligence (AI) is a scientific area that currently sees an enormous growth. Various new algorithms and methods are developed and many of them meets practical, successful applications. Authors of new algorithms draw different inspirations. Probably the most common one is the nature. For example, Artificial Neural Networks were inspired by the structure of human brain and nervous system while the classic Genetic Algorithm...
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Wind Turbines Modeling as the Tool for Developing Algorithms of Processing their Video Recordings
PublikacjaIn the real world, many factors exist disturbing observation of the examined phenomena and causing various noises and distortions in recorded signals. It very often makes it difficult or even impossible to optimize various signal processing algorithms, through finding appropriate parameters. In this paper, we show an application, that retrieves wind turbine rotor speed from recorded video. Next, we describe the process of reduction...
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Excitation of Non-Wave Modes by Sound of Arbitrary Frequency in a Chemically Reacting Gas
PublikacjaThe nonlinear phenomena in the field of high intensity sound propagating in a gas with a chemical reaction, are considered. A chemical reaction of A → B type is followed by dispersion and attenuation of sound which may be atypical during irreversible thermodynamic processes under some conditions. The first and second order derivatives of heat produced in the chemical reaction evaluated at the equilibrium temperature, density and...
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Tome-lapse X-ray tomography imaging of flow patterns in versatile silo model
PublikacjaThe paper introduces a new versatile silo model that was especially designed for in situ X-ray tomography studies of silo discharge for various flow conditions, namely concentric and eccentric. The presented work focuses on organic granular materials where low fraction of short-grain white rice is mixed with spheroidal sorghum particles. The high-quality tomography images combined with adequate image processing strategy allows...
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Turbulence models impact on the flow and thermal analyses of jet impingement
PublikacjaAccurate numerical reconstruction of heat and mass transfer processes in particular applications, such a jet impingement, is difficult to obtain even with the use of modern computational methods. In the proposed paper, the flow and thermal phenomena occurring during single minijet impingement on the flat, concave and convex, heated surfaces were considered. Problem of impingement on non-flat surface, still not common and purely...
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Good practices in requirements, project and risk managment in educational IT projects
PublikacjaOne can find many learning aids and simulations of physical phenomena on the market - provided as a standalone application or as part of an educational package. However, only a few of them allow for the building of interactive experiments: experiments similar to those that should be conducted in physics laboratories at schools. Gdańsk University of Technology decided to fill this market niche by designing and constructing a set...
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Wind Turbines Modeling as the Tool for Developing Algorithms of Processing their Video Recordings
PublikacjaIn the real world, many factors exist disturbing observation of the examined phenomena and causing various noises and distortions in recorded signals. It very often makes it difficult or even impossible to optimize various signal processing algorithms, through finding appropriate parameters. In this paper, we show an application, that retrieves wind turbine rotor speed from recorded video. Next, we describe the process of reduction...
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Analysis of the macrostructure of the fuel spray atomized with marine engine injector
PublikacjaOne of the main problem influencing the combustion process in the cylinder of the marine engine is an fuel spray phenomena. The parameters describing the shape of the fuel spray are named macro parameters. This article presents the research results of the macrostructure parameters of the fuel spray atomized with the marine engine injector. The research were carried out by optical visualization measurement method of Mie scattering....
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Weakly Hydrated Solute of Mixed Hydrophobic–Hydrophilic Nature
PublikacjaInfrared (IR) spectroscopy is a commonly used and invaluable tool in studies of solvation phenomena in aqueous solutions. Concurrently, density functional theory calculations and ab initio molecular dynamics simulations deliver the solvation shell picture at the molecular detail level. The mentioned techniques allowed us to gain insights into the structure and energy of the hydrogen bonding network of water molecules around methylsulfonylmethane...
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Knowledge management in SMEs – selected issues.
PublikacjaThe success of a small or medium-size enterprise might be dependent on the way in which this company manages its knowledge. With limited access to other resources like land, capital or labor force, the access to knowledge and its effective application might become a source of competitive advantage for an SME. It is confirmed that organizations, which successfully implement the concept of knowledge management might achieve better...
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DO WE NEED NAVIER NUMBER? – FURTHER REMARKS AND COMPARISON WITH ANOTHER DIMENSIONLESS NUMBERS
PublikacjaThis paper presents a role of the Navier number (Na-dimensionless slip-length) in universal modelling of flow reported in micro- and nano-channels like: capillary biological flows, fuel cell systems, micro-electro-mechanical systems and nano-electro-mechanical systems. Similar to another bulk-like and surface-like dimensionless numbers, the Na number should be treated as a ratio of internal viscous to external viscous momentum...
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Remarks on steam condensation modeling related to steam turbine large output
PublikacjaIn the paper numerical simulations have been performed to predict the performance of the diferent steam models. All of the considered models of steam condensation have been validated on the base of benchmark experiment employing expansion in nozzle and next on the low pressure part of the steam turbine equipped with the so-called Baumann stage. For numerical analysis three models have been finally used - the ideal steam model without...
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Scalar and Vector acoustic fields and sources: a new look
PublikacjaA study of fundamental problems of the wavefields that are the reaction of fluid continuum on two kinds of primary actions in fluid, then on two kinds of elementary point sources, is presented in this paper, based on the assumption of the physical duality of linear fluid mechanics and the formal symmetry of mathematical description. The two fundamental wavefields generated in fluid by physical point sources are discussed in detail,...
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Response of a fiber-optic Fabry-Pérot interferometer to refractive index and absorption changes – modelling and experiments
PublikacjaThis paper describes how the refractive index and the absorption of investigated substances change the spectrum of the optical radiation at the output of the fiber-optic Fabry-Pérot interferometer. The modeling of the operation of the interferometer takes into account not only the spectra of the refractive index and the absorption of the medium that is inside the cavity, but also spectra of the refractive indices of the core and...
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E-experiments in physics. Proper business process management, collaborative development process and project management guidance – remedy for avoiding the main IT project’s failure
PublikacjaOnly a few of learning aids and simulations of physical phenomena allow for building interactive experiments; experiments similar to those that should be conducted in physics laboratories at schools. Group of staff from Gdansk University of Technology decided to fill this market niche by designing and constructing a set of virtual experiments – so called e-experiments. To avoid common problems that a lot of IT products brought...
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A standard analytical method as the common good and pollution abatement measure
PublikacjaA standard method can be considered as a common-good “resource,” and the solution to “the commons” problems usually lies in societal self-organization. The multi-criteria decision analysis (MCDA) was applied to model complex phenomena, such as the standard selection for imidacloprid determination. In this process, the standard was self-selected by the analytical chemistry society. The results show that analytical chemistry is a...
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Three phase transient model of wet coal pyrolysis
PublikacjaA one-dimensional transient mathematical model was developed to describe the thermal and flow phenomena during coal pyrolysis in a coke oven. The model was solved numerically using partly implicit methods for gas flow and heat transfer problems. It was successfully validated with industrial-scale measurements of temperature change in the middle-plane of the coke oven chamber. The evolution of temperature and pressure, distributions...
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Quantum Coherence as a Resource
PublikacjaThe coherent superposition of states, in combination with the quantization of observables, represents one of the most fundamental features that mark the departure of quantum mechanics from the classical realm. Quantum coherence in many-body systems embodies the essence of entanglement and is an essential ingredient for a plethora of physical phenomena in quantum optics, quantum information, solid state physics, and nanoscale thermodynamics....
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Automatic Detection and Monitoring of Cyanobacterial Blooms in the Context of the Marine Cadastre
PublikacjaIn the wake of the European and global spatial data infrastructures (SDI) it is important to build information systems which use and serve thematic data in compliance with the INSPIRE Directive. In the context of hydrographic data, the Directive requires EU member states to collect and share information on maritime areas divided into regions and sub-regions, as well as coastal zone management areas. These data are part of recently...
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Preliminary results from HEDGEHOG REXUS project – A sounding rocket experiment on accelerations, vibrations and heat flow
PublikacjaDuring flight, a sounding rocket is subject to a unique environment - severe vibrations and substantial heat flux. In order to design payloads, precise measurement of these conditions is required. This paper presents preliminary results from HEDGEHOG REXUS Project, whose scientific goal was to characterise the thermal and dynamic environment of REXUS sounding rockets. For this purpose, two new sensors have been designed - mechanical...
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Hydrogen Bonds in Blends of Poly(N-isopropylacrylamide), Poly(N-ethylacrylamide) Homopolymers, and Carboxymethyl Cellulose
PublikacjaRecently, it was reported that the physical crosslinking exhibited by some biopolymers could provide multiple benefits to biomedical applications. In particular, grafting thermoresponsive polymers onto biopolymers may enhance the degradability or offer other features, as thermothickening behavior. Thus, different interactions will affect the different hydrogen bonds and interactions from the physical crosslinking of carboxymethyl...
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Impact of Demographic Changes onto National Economy Development
PublikacjaThe effects of population decline and their influence onto the national economy need to be analyzed with reference to modern demographic trends regarding society ageing process. The problem of demographic changes does not only concern the birth rate, life span and migration, but it also refers to economic phenomena and thus, the economic and demographic trend interrelation becomes quite obvious. Macroeconomic approach defines the...
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On Effective Bending Stiffness of a Laminate Nanoplate Considering Steigmann–Ogden Surface Elasticity
PublikacjaAs at the nanoscale the surface-to-volume ratio may be comparable with any characteristic length, while the material properties may essentially depend on surface/interface energy properties. In order to get effective material properties at the nanoscale, one can use various generalized models of continuum. In particular, within the framework of continuum mechanics, the surface elasticity is applied to the modelling of surface-related...
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Higher harmonics of the intensity modulated Photocurrent/Photovoltage spectroscopy response - a tool for studying photoelectrochemical nonlinearities
PublikacjaIn this work, a higher harmonic analysis (HHA) of the intensity modulated photocurrent/photovoltage (IMPS/IMVS) spectroscopy data is proposed as a potent tool for studying nonlinear phenomena in photoelectrochemical and photovoltaic systems. Analytical solutions of kinetic equations were constructed for cases of single and double resonance accounting for various sources of higher harmonics. These sources correspond to the physical...