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Turning maneuver as a potential cause of the next stability failure mode for a ship in operation
PublicationThe only formal stability-related requirement referring to a turning maneuver of a ship results from the IS Codeand its application is limited to passenger ships only. The goal of the adopted criterion is to prevent an excessiveangle of heel in turn. Likewise, the remaining prescriptive criteria, this one is simply based on the concept ofa threshold that must not be exceeded. In this case, the angle of heel...
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Fault Tree Analysis and Failure Diagnosis of Marine Diesel Engine Turbocharger System
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Failure of cold-formed beam: How does residual stress affect stability?
PublicationIn machine industry, stresses are often calculated using simple linear FEM analysis. Occasional failures of elements designed in such a way require recomputation by means of more sophisticated methods, eg. including plasticity and non-linear effects. It usually leads to investigation of failure causes and improvement of an element in order to prevent its unwanted behavior in the future. The study presents the case where both linear...
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Risk of power cables insulation failure due to the thermal effect of solar radiation
PublicationLow-voltage, as well as high-voltage power cable lines, are usually buried in the ground. The ampacity of the power cables in the ground mainly depends on the thermal resistivity of the soil, which may vary in a wide range. A common practice in power cable systems performance is to supply them from a pole of an overhead line. If so, a section of the line is located in free air and can be directly exposed to solar radiation. In...
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Combined thrust radial bearing of a submarine main shaft – Design and analysis of failure
PublicationThis paper presents an analysis of the combined thrust radial bearing of a submarine propulsion shaft. The lubrication system of the bearing is based on a fixed ring. The efficiency of the lubrication system depends on the shaft speed and temperature, which affects oil viscosity. In turn, the thrust bearing load also depends on the rotational speed of the shaft, because as the speed increases, the drag of the ship increases simultaneously,...
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Performance of isotropic constitutive laws in simulating failure mechanisms in scaled RC beams
PublicationResults of numerical calculations of reinforced concrete (RC) beams are presented. Based on experimental results on longitudinally reinforced specimens of different sizes and shapes are investigated. Four different continuum constitutive laws with isotropic softening are used: one defined within continuum damage mechanics, an elasto-plastic with the Rankine criterion in tension and the Drucker-Prager criterion in compression, a...
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FE-analysis of failure behaviour of reinforced concrete columns under eccentric compression
PublicationArtykuł omawia obliczanie słupów żelbetowych poddanych ściskaniu mimośrodowemu z uwzględnieniem lokalizacji odkształceń. Obliczenia wykonano przy zastosowaniu MES i sprężysto-plastycznego prawa konstytutywnego rozszerzonego o długość charakterystyczną mikrostruktury za pomocą teorii nielokalnej.
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Numerical investigation on dynamic response of a steel lattice tower under various seismic events
PublicationThe present paper presents the results of the numerical study designed to investigate the soil-structure flexibility effects on modal parameters (i.e. fundamental frequencies) and time-history analysis response (represented by the top relative displacements) of a 46.8 m high steel lattice tower subjected to a number of ground motions including also one mining tremor. In addition to the fixed-base condition, three different soil...
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Polymeric Bearings as a new base isolation system suitable for mitigating machine-induced vibrations
PublicationThe present paper summarizes the preliminary results of the experimental shaking table investigation conducted in order to verify the effectiveness of a new base isolation system consisting of Polymeric Bearings in reducing strong horizontal machine-induced vibrations. Polymeric Bearing considered in the present study is a prototype base isolation system, which was constructed with the use of a specially prepared flexible polymer...
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Dynamic analysis of temporary steel grandstand equipped with different types of bracing system
PublicationIn the paper, behaviour of a temporary steel grandstand equipped with two different types of bracing system has been analysed through the numerical study. A typical solution concerning application of a diagonal tubular members has been compared with elements proposed by authors and called polymer dampers. A polymer element consists of two L-shape steel members bonded with polymer mass. The aim of the paper is to verify the effectiveness...
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Soil-structure interaction effects on modal parameters of office buildings with different number of stories
PublicationThe paper summarizes the results of a numerical investigation designed to study the soil-structure interaction effects on modal parameters of three office buildings. The reinforced-concrete 4-storey, 8-storey, and 12-storey office buildings, each with additional two levels of embedded basements, represent low, medium, and high-rise structures, respectively. In order to conduct this research, detailed finite-element structure models...
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Advanced Hysteretic Model of a Prototype Seismic Isolation System Made of Polymeric Bearings
PublicationThe present paper reports the results of acomprehensive study designed to verify the effectiveness of an advanced mathematical model in simulating the complex mechanical behaviour of a prototype seismic isolation system made of polymeric bearings (PBs). Firstly, in order to construct the seismic bearings considered in this research, a specially prepared flexible polymeric material with increased damping properties was employed....
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Badania właściwości elastomeru polimerowego jako materiału do redukcji drgań budowli poddanych obciążeniom sejsmicznym i parasejsmicznym
PublicationCelem niniejszej pracy jest przedstawienie wyników badań eksperymentalnych, przeprowadzonych na próbkach wykonanych z elastomeru polimerowego, wykorzystywanego w metodzie złączy podatnych. W referacie zaprezentowano wyniki badań statycznych dla ściskania oraz rozciągania, a także rezultaty z dynamiczno-mechanicznej analizy termicznej (DMA), której celem było przedstawienie zmian modułu zachowawczego, modułu stratności oraz tangensa...
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NONSTRUCTURAL STIFFNESS ASSESSMENT IN INSTRUMENTED STEEL BUILDINGS
PublicationLateral stiffness of nonstructural components may significantly influence the initial stiffness of the entire structure and consequently alter its dynamic characteristics. While methods for simulating structural members are well-established, approaches for modeling nonstructural components that also participate in seismic response are notably less developed. In this paper a simplified, physically-intuitive approach for estimating...
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Polymeric Bearings – A New Base Isolation System to Reduce Structural Damage during Earthquakes
PublicationBase isolators, like lead rubber bearings, high damping rubber bearings or friction pendulum systems are extensively used in practice in many seismically active regions to protect structures against earthquake forces. The present paper reports the results obtained from the experimental study aimed to determine the effectiveness of the Polymeric Bearings in suppressing structural vibrations during dynamic excitations and therefore...
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Numerical study on seismic response of a base-isolated building modelled with shell elements
PublicationSeismic isolation is counted among the most popular and effective means of protecting structures against earthquake forces. Base isolators, like Lead-Rubber Bearings (LRB), High-Damping Rubber Bearings (HDB) or Friction Pendulum Systems (FPS) are extensively used in practice in many earthquake-prone regions of the world. The present paper reports the results obtained from the numerical study on seismic response of a base-isolated...
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Experimental study on static and dynamic properties of polymer mass
PublicationA new method of repairing damaged structures by filling the cracks with a specially prepared polymer mass has been recently proposed. This new and innovative technique, known as the Flexible Joint Method (FJM), is mainly dedicated to masonries and historical objects, where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure. The aim of the...
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Reduction of vibrations of steel structure models with Polymeric Bearings - experimental study
PublicationEarthquake-induced ground motions are the most severe and unpredictable threats to the structures all around the world. Therefore, designing earthquake protective systems has become an extremely challenging problem in civil engineering. Base isolation is one of the most popular and widely adopted methods of protecting structures against earthquake forces. The present paper reports the results obtained from the shaking table experimental...
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Behaviour of asymmetric structures with base isolation made of Polymeric Bearings
PublicationEarthquake-induced ground motions are the most severe and unpredictable threats to the structures all around the world. Seismic excitations cause a lot of damage in a wide variety of ways, leaving thousands of casualties in their wake. During the last few years alone, the world has witnessed many major earthquakes, five of which have caused far-reaching consequences of a national scale for Haiti (January 2010), Chile (February...
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Finite-element analysis of a base-isolated multi-storey steel building under seismic motions
PublicationNumerical simulation of the seismic behaviour of a multi-storey steel building, both fixed-base and base-isolated, under the 1940 El Centro earthquake was performed in this paper. The analyzed 4-storey building was decoupled from the shaking ground with the Polymeric Bearings, which can be considered a proposal of a new seismic isolation system. It consists of rectangular-shaped blocks made of a specially prepared flexible polymeric...
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Effectiveness of a mathematical model in simulating nonlinear mechanical behaviour of a seismic isolation system made of polymeric bearings
PublicationThe present study was focused on determining the effectives of a nonlinear mathematical model in simulating complex mechanical behaviour of a seismic isolation system made of Polymeric Bearings. The proposed mathematical model defines the lateral force as a nonlinear function of the shear displacement and the deformation velocity. The effectiveness of the proposed mathematical model was verified by comparing the seismic response...
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Behaviour of Asymmetric Structure with Base Isolation Made of Polymeric Bearings
PublicationEarthquake-induced ground motions are the most severe and unpredictable threats to the structures all around the world. Seismic excitations cause a lot of damage in a wide variety of ways, leaving thousands of casualties in their wake. Due to randomness of earthquake occurrence, lack of visible causes and their power of destructiveness, structural engineers need to develop new technical solutions and protection systems against...
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Ocena efektywności modelu matematycznego do opisu nieliniowego zachowania wibroizolacji sejsmicznej w postaci łożysk polimerowych
PublicationW pracy została dokonana ocena efektywności modelu matematycznego, opisującego nieliniowe zachowanie prototypu wibroizolacji sejsmicznej w postaci łożysk polimerowych. Do budowy łożysk polimerowych został wykorzystany elastomer poliuretanowy, który charakteryzuje się dobrymi właściwościami tłumiącymi. Wyniki badań materiałowych przeprowadzonych dla analizowanego polimeru zostały przedstawione we wcześniejszych publikacjach. W zaproponowanym...
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Numerical Evaluation of Dynamic Response of a Steel Structure Model under Various Seismic Excitations
PublicationThe present paper reports the results of the study, which was designed to perform a numerical evaluation of dynamic response of a single-storey steel structure model. The experimental model was previously subjected to a number of different earthquake ground motions during an extensive shaking table investigation. The analyzed structure model was considered as a 1-DOF system with lumped parameters, which were determined by conducting...
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Experimental Study on Effectiveness of a Prototype Seismic Isolation System Made of Polymeric Bearings
PublicationSeismic isolation is identified as one of the most popular and effective methods of protecting structures under strong dynamic excitations. Base isolators, such as Lead Rubber Bearings, High Damping Rubber Bearings, and Friction Pendulum Bearings, are widely used in practice in many earthquake-prone regions of the world to mitigate structural vibrations, and therefore minimize loss of life and property damage during seismic events....
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Estimation of nonstructural stiffness in instrumented steel frames
PublicationLateral stiffness of nonstructural components may significantly influence the initial stiffness of the entire structure and consequently alter its dynamic characteristics. While methods for simulating structural members are well-established, approaches for modeling nonstructural components that also participate in seismic response are notably less developed. In this paper a simplified, physically-intuitive approach for estimating...
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Broadband NIR emission from rare earth doped-SiO2-Nb2O5 and SiO2-Ta2O5 nanocomposites
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Fabrication and Characterization of Flexible Medical-Grade TPU Filament for Fused Deposition Modeling 3DP Technology
PublicationThe possibility of using additive manufacturing (AM) in the medicine area has created new opportunities in health care. This has contributed to a sharp increase in demand for 3D printers, their systems and materials that are adapted to strict medical requirements. We described herein a medical-grade thermoplastic polyurethane (S-TPU) which was developed and then formed into a filament for Fused Deposition Modeling (FDM) 3D printers...
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Fabrication, structural and electrical properties of Sr(V,Nb)O 3-δ perovskite materials
PublicationThe SrV1-xNbxO3-δ materials with different niobium content in perovskite B-sublattice were prepared by a solid-state reaction process. The microstructure and phase compositions of obtained samples were analyzed by the X-ray diffraction technique (XRD) and scanning electron microscopy (SEM). The electrical conductivity of samples was measured by a DC 4-wire method in range of 100–600 °C in different gas conditions. The oxidation...
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Fabrication and Characterization of Flexible Medical-Grade TPU Filament for Fused Deposition Modeling 3DP Technology
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Fabrication and characterization of composite TiO2 nanotubes/ boron-doped diamond electrodes towards enhanced supercapacitors
PublicationThe composite TiO2 nanotubes / boron-doped diamond electrodes were deposited using Microwave Plasma Enhanced Chemical Vapor Deposition resulting in the improved electrochemical performance. This composite electrode can deliver high specific capacitance of 7.46 mF cm‐− 2 comparing to boron-doped diamond (BDD) deposited onto flat Ti plate (0.11 mF cm‐− 2).The morphology and composition of composite electrode were characterized...
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Fabrication, Microstructure and High Temperature Corrosion Resistance of Porous Alloys for Solid Oxide Fuel Cells
PublicationPorous alloys find use in modern Solid Oxide Fuel Cells as the supporting structures. As they are exposed to high temperatures (> 500°C) an oxide scale forms on their surface due to high temperature corrosion phenomena. Since the ratio between the surface area and volume is much higher than for planar samples, formation of the oxide can lead to a breakaway oxidation after relatively short times. Therefore corrosion properties of...
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Fabrication and Significant Photoelectrochemical Activity of Titania Nanotubes Modified with Thin Indium Tin Oxide Film
PublicationOrdered titanium dioxide nanotubes (TiO2NTs) modified with indium tin oxide (ITO) films were obtained via magnetron sputtering, in which ITO plate was used as a target, onto the as-anodized titania support followed by the calcination process. The morphology of fabricated material with deposited oxide was investigated using scanning electron microscopy. Raman and UV–Vis spectroscopies were utilized to characterize crystalline phase...
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An Aqueous Exfoliation of WO3 as a Route for Counterions Fabrication—Improved Photocatalytic and Capacitive Properties of Polyaniline/WO3Composite
PublicationIn this paper, we demonstrate a novel, electrochemical route of polyaniline/tungsten oxide (PANI)/WO3) film preparation. Polyaniline composite film was electrodeposited on the FTO (fluorine-doped tin oxide) substrate from the aqueous electrolyte that contained aniline (monomer) and exfoliated WO3 as a source of counter ions. The chemical nature of WO3 incorporated in the polyaniline matrix was investigated using X-ray photoelectron...
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Fabrication of ILs-Assisted AgTaO3 Nanoparticles for the Water Splitting Reaction: The Effect of ILs on Morphology and Photoactivity
PublicationThe design of an active, stable and ecient photocatalyst that is able to be used for hydrogen production is of great interest nowadays. Therefore, four methods of AgTaO3 perovskite synthesis, such as hydrothermal, solvothermal, sol-gel and solid state reactions, were proposed in this study to identify the one with the highest hydrogen generation eciency by the water splitting reaction. The comprehensive results clearly show that...
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Badania i analiza polaryzacji fal radiowych w sieciach BAN typu off-body w zamkniętym środowisku propagacyjnym
PublicationW artykule przedstawiono pomiarowe badania i analizę uwarunkowań propagacyjnych w sieciach pracujących w bezpośrednim otoczeniu ciała człowieka, w środowisku wewnątrzbudynkowym. Opisano stanowisko pomiarowe oraz scharakteryzowano badane środowisko propagacyjne. Przeanalizowano siedem scenariuszy pomiarowych (pięć statycznych i dwa dynamiczne) dla dwóch osób o różnej budowie ciała, a także dla przypadku anteny zamontowanej na dielektrycznym...
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Fully Automated AI-powered Contactless Cough Detection based on Pixel Value Dynamics Occurring within Facial Regions
PublicationIncreased interest in non-contact evaluation of the health state has led to higher expectations for delivering automated and reliable solutions that can be conveniently used during daily activities. Although some solutions for cough detection exist, they suffer from a series of limitations. Some of them rely on gesture or body pose recognition, which might not be possible in cases of occlusions, closer camera distances or impediments...
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Gamma irradiation mediated production improvement of some myco-fabricated nanoparticles and exploring their wound healing, anti-inflammatory and acetylcholinesterase inhibitory potentials
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Charakterystyka stopu Ł83 wytworzonego metodami odlewania i natryskiwania cieplnego = Characteristic of the Ł83 alloy fabricated by casting and thermal spraying methods
PublicationPrzedstawiono mikrostrukturę i twardość stopu łożyskowego Ł83 wytworzonego metodami natryskiwania cieplnego i odlewania odśrodkowego. W tym aspekcie dokonano analizy przydatności metody natryskiwania w produkcji łożysk ślizgowych.
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Synthesis and structural properties of (Y, Sr)(Ti, Fe, Nb)O3−δ perovskite nanoparticles fabricated by modified polymer precursor method
PublicationThe yttrium, iron and niobium doped-SrTiO3 powders have been successfully fabricated by a modified low–temperature synthesis method from a polymer complex. The usage of strontium hydroxide precursor instead of conventional strontium nitrate or strontium carbonate provides to the possibility of significant decrease of annealing temperature. It allows to prepare a material with sphere-shape grains of nanometric size (15–70 nm). The...
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Crack identification using wavelets on experimental staticdeflection profiles
PublicationArtykuł prezentuje metodę lokalizacji uszkodzeń w belce wspornikowej za pomocą transformaty falkowej statycznej linii ugięcia. Efektywnośc proponowanej techniki jest sprawdzona na podstawie badań eksperymentalnych. Do pomiaru statycznej linii ugięcia proponuje się metodę fotogrametryczną.
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Piecewise continuous distribution function method in the theory of wave disturbances of inhomogeneous gas
PublicationUkład równań typu hydrodynamicznego dla warstwowych gazów w polu grawitacyjnym pochodzi od równania BGK metodą częściowej ciągłej funkcji dystrybucji. Otrzymany system równań uogólnia układ Naviera-Stokesa w dowolnych liczbach Knudsena.
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Numerical modelling of different airbag folding patterns and their influence on occupant responses in frontal vehicle impact
PublicationThis paper presented a procedure for airbag folding for the application in occupant safety studies and analysed the influence of different airbag folding patterns on the occupant severity in frontal impact. Airbags were folded in two patterns: zig-zag and top-roll, using two folding techniques: Initial Metric Method and Explicit Folding. The explicit folding was found to be more expensive in terms of preparation time. However,...
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SPECTROPHOTOMETRIC DETERMINATION OF FOUR NAPHTHALENE SULFONATES IN SEAWATER AFTER THEIR MOLECULARLY IMPRINTED STIR BAR SORPTIVE EXTRACTION
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Molecularly imprinted stir bar sorptive extraction coupled with high-performance liquid chromatography for trace analysis of naphthalene sulfonates in seawater
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Occurrence of organic phosphates in particulate matter of the vehicle exhausts and outdoor environment – A case study
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Heat transfer enhancement of modular thermal energy storage unit for reversible heat pump cooperation
PublicationThe following article presents experimental comparison research on a hexagonal shelland-tube latent thermal energy storage (TES). Such shape of a shell was deliberately chosen instead of a cylindrical one due to its high modularity and with intent for future applications in automobiles (EV and PHEV) air conditioning systems (HVAC). Two geometries of helical coils, acting as tubes, were studied in this article. One was a simple...
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The In-House Method of Manufacturing a Low-Cost Heat Pipe with Specified Thermophysical Properties and Geometry
PublicationVarious types of heat pipes are available to purchase off the shelf, from various manufacturers, but most of them have strictly defined geometry and technical parameters. However, when there is a need to use a heat pipe (HP) with an unusual size and shape or working conditions other than the standard ones, it becomes very costly to order them from manufacturers, especially in small quantities, and only a few producers are willing...
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New approach for e-cigarette aerosol collection by an original automatic aerosol generator utilizing melt-blown non-woven fabric
PublicationCurrently, there is lack of standardized conditions for the collection and analysis of e-cigarette (EC) aerosol. Considering the urgent need for the development of these guidelines, a procedure for EC aerosol analysis was developed. A novel automatic e-cigarette aerosol generator was designed. For the first time, melt-blown non-woven fabric was applied for the effective uptake of compounds released from vaporized e-liquid. The...
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Analiza elektromodulowanej fotoluminescencji w organicznych układach molekularnych
PublicationCelem niniejszej rozprawy doktorskiej jest poddanie interpretacji danych doświadczalnych uzyskanych w pomiarach elektromodulowanej fotoluminescencji (EML), na gruncie różnych modeli teoretycznych separacji nośników ładunku pod wpływem zewnętrznego pola elektrycznego w organicznym molekularnym ciele stałym. Zainteresowanie powyższą tematyką wynika z konieczności weryfikacji istniejących modeli zjawisk fizycznych w materiałach molekularnych...