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Importance of Specific Heat Characterization when Reporting New Superconductors: An Example of Superconductivity in LiGa2Rh
PublicationWe show that the full-Heusler compound LiGa2Rh is a superconductor with Tc = 2.4 K. The new superconductor was found as a result of an intuition-based extension of a database search for superconductors that looked for the presence of peaks in the electronic band structure near the Fermi energy. The measurement of the entropy loss during the transition from the nonsuperconducting to the superconducting state, a straightforward measurement...
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Sensitivity analysis of flexural and torsional buckling loads of laminated columns
PublicationThe paper concerns first order sensitivity analysis of flexural and torsional bucklin g loads of axiallycompressed thin-walled columns with bisymmetric or axisymmetric cross-section made of unidirectional fibre-reinforcedlaminate. The first variation of critical loads versus some variations of the column material properties and cross-sectionaldimensions is derived. Numerical examples dealing with simply supported I-columns are...
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Quantitative assessment
PublicationThe main trends in the development of analytical chemistry are the determination of increasingly lower concentrations of analytes in samples with complex matrix composition (trace analysis). While the obtained analytical results must be reliable, which means that they must accurately (truly and precisely) reflect the actual content of analytes in a representative sample of the material object under study. However, it is an extremely...
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Influence of steel brackets supporting crane runway girders structure on the stress distribution in the brackets
PublicationThe paper presents a numerical analysis of steel brackets supporting a double-span crane runway girders. The purpose of the study was to assess the new structural solution based on the stress distribution in the brackets. In order to simplify the connection, the bottom flange of the crane runway girder is based directly on the upper flange of the bracket. As a result, the support reaction is no longer applied in the plane of the...
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Substrate Dependence in the Formation of Au Nanoislands for Plasmonic Platform Application
PublicationIn this work, the influence of the various substrates on Au nanoisland formation has been studied. Nanostructures were obtained via annealing of thin Au films. In order to determine nanoisland formation mechanisms, correlation between an initial film thickness and temperature of formation, shapes, and dimensions of nanostructures was examined. For the surface morphology studies, nanograin structure, and chemical composition analysis,...
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Influence of Phase Composition on Dielectric Properties of Bismuth-Based Ceramics with Scheelite-Type Structure
PublicationGoal of the present research was to study dielectric properties of BiNbO4 ceramics fabricated by solid state reaction route followed with pressureless sintering. The samples were fabricated from the mixture of oxides, viz. Nb2O5 and Bi2O3. Apart from stoichiometric amount an excess of 3%, 5% and 10% by mole of Bi2O3 was used. It was found that an excess amount of Bi2O3 oxide caused formation of Bi5Nb3O15 minor phase in amount of...
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Rheology of polymer blends
PublicationPolymer blends are physical mixtures of two or more homopolymers or copolymers. This type of materials have wide spectrum of technological applications, and their properties are influenced, e.g., by the properties of single components and morphology of final material. The rheology of polymer blends is connected with the processing of polymer blends and is influenced by thermodynamics, morphology, and their evolution during testing....
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Buckling analyses of metal cylindrical silos containing bulk solids during filling
PublicationThe paper presents 3D results on stability of thin-walled cylindrical metal silos made of isotropic rolled and corrugated plates containing bulk solids. The behavior of bulk solids was described using a hypoplastic constitutive model. Nonlinear finite element (FE) analyses with both geometric and material nonlinearity were performed with a perfect and an imperfect silo shell wherein initial geometric imperfections were taken into...
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MODELLING OF CONCRETE FRACTURE AT AGGREGATE LEVEL USING DEM BASED ON X-RAY mu CT IMAGES OF INTERNAL STRUCTURE
PublicationThe paper describes two-dimensional meso-scale numerical results of fracture in notched concrete beams under quasi-static three-point bending. Concrete was modelled as a random heterogeneous 4-phase material composed of aggregate particles, cement matrix, interfacial transitional zones (ITZs) and air voids. As a numerical approach, the discrete element method (DEM) was used. The concrete micro-structure in calculations was directly...
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Mesoscopic simulations of crack propagation in concrete using cohesive elements
PublicationThe paper presents results of two-and three-dimensional meso-scale simulations of fracture in notched concrete beams subjected to three-point bending test. Concrete was assumed as a 3-phase material composed of aggregate grains placed in the cement matrix with Interfacial Transitional Zones (ITZs) between then. In 2D simulations macro-voids were also taken into account. The particle distribution was taken from real concrete beams...
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„Jeśli my zapomnimy, kto będzie pamiętał?". Dzieło sztuki jako manifestacja postpamięci
PublicationTekst jest próbą ujęcia relacji między postpamięcią (lub inaczej ujmując - „pamięcią zastępczą”) a sztuką, przy czym szczególny akcent położono na sztuki wizualne. Dokonano analizy dzieł artystów młodszego pokolenia, podejmujących temat pamięci o Szoa (między innymi Libera, Bałka, Żmijewski, do pewnego stopnia Betlejewski), traktując je jako formy manifestacji postpamięci. Wychodząc z założenia, że analiza zjawisk artystycznych...
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Opracowanie technologii naprawy nieciągłości metalicznych w połączeniach spawanych, w konstrukcji podpór przednich pras filtracyjnych położonych na terenie Grupowej Oczyszczalni Ścieków Dębogórze
PublicationCelem niniejszej pracy jest opracowanie wytycznych technologicznych, których wdrożenie pozwoli na usunięcie istniejących pęknięć, co przyczyni się do stabilizacji wymiarowej podpór oraz całej konstrukcji pras. Osiągniecie tego celu wymaga podjęcia następujących działań: - ocenę stanu technicznego naprawianego komponentu- podpór przednich trzech pras filtracyjnych, - określenie własności spawalniczych materiału naprawianego, -...
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Electrochemical Characterization of Gelatine Derived Ceramics
PublicationNew materials obtained by pyrolysis of gelatine (G) and poly(1,2-dimethylsilazane) (PSN) (weight ratio: G/PSN 70/30) at temperatures 700 and 900 °C were characterized by SEM and Raman spectroscopy. The presence of ceramics influences on the cluster size of the materials. Electrochemical tests were performed by cyclic voltammetry and galvanostatic cyclic polarization. The capacity of G/PSN was 464 and 527 mAh/g for materials pyrolysed...
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Characterization of magnesium doped lanthanum orthoniobate synthesized by molten salt route
PublicationMolten salt synthesis method has been used to prepare the single phase magnesium doped lanthanum orthoniobate. The phase composition has been checked by X-ray diffraction method and the microstructure studies have been performed by scanning electron microscopy. The high temperature properties of the material have been investigated by thermogravimetry and electrochemical impedance spectroscopy. A dependence between sample total...
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Characterization of CaTi0.9Fe0.1O3/La0.98Mg0.02NbO4 composite
PublicationA composite of CaTi0.9Fe0.1O3 and electrolyte material, i.e. magnesium doped La0.98Mg0.02NbO4 was prepared and studied. The phase content and the sample microstructure was examined by an X-ray diffraction method and scanning electron microscopy. EDS measurements were done both for composite samples and the diffusion couple. The electrical properties were studied by four terminal DC method. The Ahigh-temperature interaction between...
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THE INFLUENCE OF WSR PARAMETER ON PET BOTTLE THICKNESS PROFILE IN SBM FROM PREFORM PROCESS
PublicationFrom a mechanical point of view, the thickness profile of PET bottles manufactured by ISBM process is determined by mechanical and thermal response of blown preforms. From the microscopic point of view the biggest influence on the mechanical and thermal properties of PET bottles have orientation and crystallization processes. From a technological point of view, the thickness profile of PET bottles after manufacture by SBM process...
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Representation of magnetic hysteresis in tape wound core using feedback Preisach model
PublicationThis paper presents a mathematical model for the hysteresis phenomenon in ferromagnetic tape wound core. The feedback scalar Preisach model of hysteresis is used to simulate magnetic behavior of the grain oriented silicon strip of ET114-27 type. Determination of B-H hysteretic curve is based on measurement of the initial magnetization curve and the main hysteresis loop. The Preisach distribution function (PDF) of ET114-27 material...
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Corrosion Study of Ceria Protective Layer Deposited by Spray Pyrolysis on Steel Interconnects
PublicationSingle fuel cells and electrolysis cells are assembled into stacks using interconnects in order to increase power and gas production capacity. The most common choice for the interconnect material is stainless steel. It has good electrical and mechanical properties and is also cost effective. One of the problems when using steel is the formation of a thermally grown oxide scale during use which has a lower electrical conductivity...
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New plasmonic platform for enhanced luminescence of Valrubicin
PublicationLuminescence enhanced by new structure of plasmonic platform with aluminum oxide (Al2O3) buffer layer deposited on gold nanostructures is investigated. Regularly distributed gold nanostructures of average dimension of 50 nm formed the active part of plasmonic platforms. They were manufactured on Corning 1737 glass substrate by melting of gold thin film. The nanostructures were coated by dielectric Al2O3 thin film with thickness...
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Logistics of Transnational Corporations as the Basis of Cooperation Between Ukraine and EU (for Poland Example)
PublicationThe article describes the scientific and theoretical basis for the organization of logistics management of modern international corporations, owning by assets in mining and metallurgical business in Ukraine and Poland; it had been analyzed the influence of transfer pricing mechanism as one of the main factors affecting on the efficiency of the organization of supply chain of resources (Ukrainian semi-finished goods) to ensure uninterrupted...
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Experimental and numerical evaluation of mechanical behaviour of composite structural insulated wall panels under edgewise compression
PublicationA composite structural insulated sandwich panel (CSIP) is a quite novel approach to the idea of sandwich structures. A series of natural-scale experimental test is required each time a change in panel’s geometry is planned and a reliable computational tool is required to precede actual laboratory testing with virtual simulations. An attempt of creating such a tool has been made with use of a commercial FEM code ABAQUS, in order...
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On the peculiarities of anti-plane surface waves propagation for media with microstructured coating
PublicationWe discuss new type of surface waves which exist in elastic media with surface energy. Here we present the model of a coating made of polymeric brush. From the physical point of view the considered model of surface elasticity describes a highly anisotropic surface coating. Here the surface energy model could be treated as 2D reduced strain gradient continuum as surface strain energy depends on few second spatial derivatives of...
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Polyurethanes as a Potential Medical-Grade Filament for Use in Fused Deposition Modeling 3D Printers – a Brief Review
PublicationThe possibility of using 3D printing technology (3DP) in medical field is a kind of revolution in health care. This has contributed to a rapid growth in demand for 3D printers, whose systems and materials are adapted to strict medical requirements. In this paper, we report a brief review of polyurethanes as a potential medical-grade filament for use in Fused Deposition Modeling (FDM) 3D printer technology. The advantages of polyurethanes...
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Comparison of Acoustic and Visual Voice Activity Detection for Noisy Speech Recognition
PublicationThe problem of accurate differentiating between the speaker utterance and the noise parts in a speech signal is considered. The influence of utilizing a voice activity detection in speech signals on the accuracy of the automatic speech recognition (ASR) system is presented. The examined methods of voice activity detection are based on acoustic and visual modalities. The problem of detecting the voice activity in clean and noisy...
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Three-point bending test of sandwich beams supporting the GFRP footbridge design process - validation
PublicationSome selected aspects concerning material and construction design issues for pedestrian footbridge made of GFRP composite materials are elaborated in this paper. The analysis is focused on validation tests, which are particularly important because of the advanced technology and materials that are used for this innovative bridge. The considered footbridge is a sandwich-type shell structure comprising of PET foam core and outer skins...
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The low temperature waste heat recovery in drying process of pine wood using micro-jet heat exchanger
PublicationThe article presents the influence of the drying medium temperature changes for the relative and absolute moisture content values during pine wood drying. The drying process was conducted at constant atmospheric pressure and with different drying medium (air) temperature levels, respectively: 40oC, 60oC, 80oC, 100oC, and 120oC. In order to develop a method that would enable low temperature drying of solid materials the experiments...
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Experimental and numerical analysis of an aluminum cantilevered beam with polymer adhesive
PublicationIn this paper, experimental and numerical investigation on a composite cantilevered aluminum beam has been conducted. The subject of the study consists of two plain aluminum elements bonded with polymer adhesive of different thickness. It has been proven in the previous study that this kind of material has high damping properties. During an experimental investigation, value of damping ratios have been obtained. The aim of a numerical...
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Application of spectroscopy to the measurement of blood parameters
PublicationSpectroscopy is the study of formation and interpretation of the spectra arising from the interactions of all types of radiation on matter, understood as a collection of atoms and molecules. This is a very important department of optics which gives us many opportunities to measure various parameters such as material blood parameters. Among the diseases that are associated significantly with changes in rheological properties of...
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Sessile droplet contact angle of water–Al2O3, water–TiO2 and water–Cu nanofluids
PublicationThis work presents measurements of the contact angle of sessile droplets for three nanofluids, i.e. water–Al2O3, water–TiO2 and water–Cu. The plates made of glass, anodized aluminium and stainless steel of different roughness served as substrates. Ultrasonic vibration was used for 30–60 min in order to stabilise the dispersion of the nanoparticles. Nanoparticles were tested at the concentration of 0.01%, 0.1%, and 1% by weight....
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Stability Investigation of the PCM Nanocomposites
PublicationEnsuring the stability is a key issue to be solved for the technical application of nanocomposites. In this work, fatty acid P1801 served as base phase change material (PCM)P1801, and its main ingredients are palmitic acid (58%) and stearic acid (38%). Titania (TiO2) and alumina (Al2O3) with mass concentrations of 1% and 5% were selected as nanoparticles, while polyvinylpyrrolidone (PVP) or oleic acid (OA) with mass concentrations...
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Inverse determination of sliding surface temperature based on measurements by thermocouples with account of their thermal inertia
PublicationThis study developed an inverse heat conduction algorithm to determine temperature at a sliding surface taking account of thermocouple thermal inertia. The direct heat conduction problem was solved analytically based on the Laplace integral transform approach. The inverse algorithm was applied to the problem of friction of a brake material against a steel. The experiments were conducted on a pin-on-disc tribometer for three short-time...
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Application of the corrosion tester in corrosion tests using the acoustic emission method.
PublicationThe article presents an innovative method of corrosion tests using the acoustic emission method and the corrosion tester. The problem of corrosion occurring in ballast tanks and tanks carrying petroleum products is discussed. The acoustic method is presented which, due to the use of a unique corrosion tester, is used to monitor the course of corrosion processes in steel. The principle of operation of the corrosion tester, its construction...
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Modeling, simulation, and validation of a TB41 crash test of the H2/W5/B concrete vehicle restraint system
PublicationThe paper addresses numerical simulations of a concrete vehicle restraint system. The model is described in detail. The advanced material law of the continuous surface cap model was used to analyze the damage locations in concrete barrier segments. The results were validated against the TB41 full-scale crash test. The test was conducted in compliance with European standard EN 1317, and the validation was performed in accordance...
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New approach for the synthesis of Ag3PO4-graphene photocatalysts
PublicationA facile and effective plasma sputtering method for the preparation of a visible light active photocatalyst - rhombic dodecahedral silver phosphate Ag3PO4 covered with nanographene (Ag3PO4-GR) with improved stability has been developed. Proposed method allows for the usage of readily available materials for nanographene sputtering and for easy scaling-up. The stability improvement, confirmed by visible light-induced phenol degradation...
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On modelling and non-linear elasto-plastic analysis of thin shells with deformable junctions
PublicationThe undeformed base surface of the irregular thin shell is modelled by the union of a finite number of regular smooth surface elements joined together along spatial curvilinear surface edges. The equilibrium conditions are formulated by postulating an appropriate form of the principle of virtual work, where also deformability of shell junctions is taken into account. The PVW is then discretised by C1 finite elements and the incremental-iterative...
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Roads unsafety - social costs
PublicationThe condition of road safety has a significant impact on the quality of citizens' life. Yearly, one in a hundred families in Poland suffers because of road accidents. It is affected by them not only in material terms but first and foremost in moral terms. Road accidents are one of the main causes of degradation in the quality of life. In Poland we hardly know anything about the fate of the road traffic victims, their life problems...
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Possibilities of Phoslock® application to remove phosphorus compounds from wastewater treated in hybrid wetlands
PublicationTreatment wetland technologies for wastewater treatment can be easily applied for removal of all pollutants except phosphorous. They are applicable in a small towns and rural areas, places where conventional wastewater treatment plant cannot properly operate because of common economic constraints. In Poland only the 8% of rural areas are equipped with sewer system, thus treatment wetlands might be an alternative, effective and...
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A review of phosphorus recovery methods at various steps of wastewater treatment and sewage sludge management. The concept of “no solid waste generation” and analytical methods
PublicationPhosphorus deposits around the world are rapidly depleting, therefore phosphorus recovery methods are gaining more and more interest both in science and industry. This article presents the main methods of phosphorus recovery from sewage sludge. The described approaches are divided in two groups: phosphorus recovery from sewage sludge and leachate, and recovery of phosphorus from sewage sludge ashes. The latter seems to have more...
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Numerical and Clinical Analysis of an Eyeball Injuries under Direc Impact
PublicationObjectives: The objective of this study was to develop a numerical model of the eyeball and orbit to simulate a blunt injury to the eyeball leading to its rupture, as well as to conduct a comparative analysis of the results obtained using the finite element method against the clinical material concerning patients who had suffered an eyeball rupture due to a blunt force trauma. Material and Methods: Using available sclera biometric and...
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Revitalization of Residential Buildings Dating Back to the Late19th and Early 20th Century on the Example of “Willa Halina” in Sopot (Poland)
PublicationResidential buildings dating back to the late 19th and early 20th century constitute an important element of the urban composition of many European cities, often determining their overall spatial expression. These buildings often require revitalization and sometimes also reconstruction or extension. Such activities make it possible to restore historical buildings to their former glory, but also to create new architecture, inscribed...
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Fire Protection and Materials Flammability Control by Artificial Intelligence
PublicationFire safety has become a major challenge of materials developers because of the massive production of organic materials, often combustibles, and their use for different purposes. In this sense, fire safety is critically considered in the development of engineering materials [1, 2]. The multiplicity of parameters contributing to the development of formulation of flame-retardant materials from one side and the sustainability concerns...
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Hydrothermal synthesis of vanadium ammonium compounds – the crucial role of the pressure
PublicationDue to the structural diversity and chemical activity, vanadium oxides and their derivatives are continuingly in the great interest of scientist. In a large family of vanadium compounds, one of the most interesting are ammonium vanadates (with the general formula (NH4)xVyOz). They have received much attention because of their promising application as cathode material in mono- and multivalent-ion batteries [1]. Hydrothermal synthesis...
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Drewniane więźby dachowe żuławskich domów podcieniowych typu III – badania, stan zachowania, analiza
PublicationZabytkowe domy podcieniowe ujścia Delty Wisły były obiektem zainteresowań wielu badaczy, jednak ich prace koncentrowały się głównie na aspektach historyczno-architektonicznych. Nie ma publikacji skupiających się na szczegółach i dokładnych analizach ustrojów budowlanych dla tej grupy historycznych obiektów. Artykuł jest rezultatem badań terenowych, kwerendy archiwalnej i obliczeń wykonanych przez autora....
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Resonant ultrasonic spectroscopy in high-voltage varistor spectroscopy
PublicationResonant spectroscopy is an effective non-destructive testing method focused on defects in tested objects. The testing procedure, based on the resonant pattern, allows rejection of the tested samples with defects which do not fit the pattern. A sweeping frequency method has been used to measure the spectrum of resonances in high-voltage varistors. As a result we can observe resonances that depend directly on inhomogeneity of the...
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Potrzeby osób z niepełnosprawnością a budżet obywatelski. Wyniki ankiety opinii wśród społeczności warszawskiego Muranowa
PublicationThe participatory budget in Warsaw is a form of citizen involvement in city planning. The projects submitted in the budget concern, among other things, the physical transformation of space, organizing events integrating the community, and educational programs. Each of the above categories may determine the inclusion of people with disabilities in society. Social inclusion in the perspective of city change is an interesting and...
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Lower Rim Substituted p-tert-Butyl-Calix[4]arene. Part 16. Synthesis of 25, 26, 27, 28-tetrakis(piperidinethiocarbonylmethylene)-p-tert-butylcalix[4]arene and its interaction with metal ions
PublicationThe synthesis, characterisation and X-ray crystal structures of p-tert-butyl-calix[4]arenethioamide L and its complex with lead L-Pb2+ is reported. The cation-binding properties in solution have been assessed by liquid-liquid extraction of the metal picrates from water into dichloromethane and by stability constants determination in acetonitrile using UV-absorption spectrophotometry or potentiometry. The compound was used as active...
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Maszyny elektryczne wokół nas. Poszukiwanie dróg do nauczania na kierunku Elektrotechnika Politechniki Gdańskiej = Electrical machines around us. searching for teaching ways at electrical engineering of the Gdansk University of Technology
PublicationStreszczenie angielskie: This paper provides a summary of the didactic assumptions, goals and approach concerning the syllabus and description/modelling of electrical machines (EM) for teaching in the field of power electrical engineering at the Gdansk University of Technology. They have been used to write e-text book entitled "Electrical machines around us" that covered the lectures on electrical machines given for the second...
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Corrosion of evaporator tubes in low emission steam boilers
PublicationPurpose of this paper is to reveal the mechanisms of corrosion processes of outer surfaces of low-emission steam boiler evaporator tubes. Examinations were performed to find the reasons of different corrosion susceptibility of tubes situated at combustion chamber on various levels. Examinations were conducted on several segments of 57 x 5.0 mm evaporator tubes made of 16M (16Mo3) steel grade. Segments were taken from level of...
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Modeling the electrical characteristics of P3HT:PCBM bulk heterojunction solar cells: Influence of the interface recombination
PublicationThe interface recombination of charge carriers located in the material with lower permittivity (Szmytkowski 2009 Chem.Phys.Lett. 470 123) has been implemented for the first time to calculate the electrical characteristics of the donor-acceptor P3HT:PCBM bulk heterojunction solar cell. In order to estimate the photocurrent density in this system, a simple analytical formula has been derived. We have obtained a very good agreement...
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Some kind of joints in composite polymer bridges
PublicationContemporary, polymer composites bridge structures are of two types: truss or arch structures(with many joints along the length) and beam structures with limited number of joints. Both of them have special types of composite polymer decks. An ideal solution is to join advantages of two types of structuresdescribed below and create long span FRP beam bridge structure system using joints along the length. Theproblem is to find the...