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Hydrogen embrittlement of X2CrNiMoCuN25-6-3 super duplex stainless steel welded joints under cathodic protection
PublicationThe effect of cathodic polarization conditions on hydrogen degradation of X2CrNiMoCuN25-6-3 super duplex stainless steel welded joints, obtained using flux cored arc and submerged arc welding methods, was evaluated. Slow strain rate tensile tests of base material and welded specimens, ferrite content measurements, scanning electron microscopy observations, and statistical analysis were performed. It was found that hydrogenation...
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Crystal structure and electronic structure of CePt2In7
PublicationWe report a corrected crystal structure for the CePt2In7 superconductor, refined from single crystal x-ray diffraction data. The corrected crystal structure shows a different Pt–In stacking along the c-direction in this layered material than was previously reported. In addition, all of the atomic sites are fully occupied with no evidence of atom site mixing, resolving a discrepancy between the observed high resistivity ratio of...
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Measurements of Spectral Spatial Distribution of Scattering Materials for Rear Projection Screens used in Virtual Reality Systems
PublicationRapid development of computing and visualisation systems has resulted in an unprecedented capability to display, in real time, realistic computer-generated worlds. Advanced techniques, including three-dimensional (3D) projection, supplemented by multi-channel surround sound, create immersive environments whose applications range from entertainment to military to scientific. One of the most advanced virtual reality systems are CAVE-type...
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A Numerical Model Study on Grasse River Ice Control Structures
PublicationIce jams in the Grasse River have caused the erosion of capping material designed to prevent the resurfacing of the bed sediment in the PCB-contaminated area. Two in-stream ice-control structures are proposed to avoid the jam-induced erosion of the capping material. These two ice-control options are a pier-type ice-control structure and a reconstruction of a small hydropower dam upstream of the capping site. A numerical model study...
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Two-dimensional simulations of concrete fracture at aggregate level with cohesive elements based on X-ray lCT images
PublicationThe paper presents results of two-dimensional meso-scale simulations of fracture in notched concrete beams subjected to three-point bending test. Concrete was assumed as a 4-phase material composed of aggregate grains placed in the cement matrix, interfacial transitional zones (ITZs) and macro-voids. The particle distribution was taken from real concrete beams on the basis of X-ray lCT images. Comprehensive numerical analyses were carried...
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Wybrane problemy plastyczności w płaskim ośrodku mikropolarnym
PublicationW pracy analizuje się sprężysto-plastyczny płaski ośrodek mikropolarny. Do rozwiązań równań plastyczności wykorzystuje się technikę Closest Point Projection Method. Przedstawiono przykład numeryczny w płaskim stanie naprężenia, zasygnalizowano problem lokalizacji w zadaniach z osłabieniem materiału.
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Tailoring Graphene to Achieve Negative Poisson's Ratio Properties
PublicationGraphene can be made auxetic through the introduction of vacancy defects. This results in the thinnest negative Poisson's ratio material at ambient conditions known so far, an effect achieved via a nanoscale de-wrinkling mechanism that mimics the behavior at the macroscale exhibited by a crumpled sheet of paper when stretched.
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Determinanty i efekty uczenia się wydziałów ekonomicznych publicznych szkół wyższych województwa pomorskiego
PublicationPubliczne uczelnie wyższe jako twory przez lata bardzo zhierarchizowane, ze znacznymi przejawami biurokratyzmu i silnie scentralizowaną władzą, w XXI wieku mają przed sobą długą drogę w dążeniu do doskonalenia własnej zdolności do uczenia się. Głównym celem pracy było zdiagnozowanie stanu determinant i efektów uczenia się badanych organizacji. Postawiono następujące hipotezy badawcze: poziom determinant uczenia się wydziałów ekonomicznych...
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Mikrostruktura kompozytów poliestrouretanowo-gumowych wulkanizowanych siarką o różnej zawartości recyklatu gumowego
PublicationIntensywny rozwój przemysłu motoryzacyjnego szczególnie widoczny w przeciągu ostatnich kilkudziesięciu lat w krajach silnie rozwijających się na całym świecie, w tym również w Polsce generuje powstawanie coraz większej ilości poeksploatacyjnych opon samochodowych. Statystyki podają, że co roku w Polsce przybywa ok. 259 tys. ton poużytkowych opon samochodowych, w tym, ok. 16 tys. ton jest poddawane bieżnikowaniu, ok. 53 tys. ton...
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Set-Bounded joined parameter and state estimation for model predictive control of integrated wastewater treatment plant systems at medium time scale.
PublicationW artykule opisano moduł łącznej estymacji w postaci zbiorów ograniczonych (ang. set-bounded) parametrów i stanu systemu dla potrzeb sterowania predykcyjnego zintegrowanym systemem ściekowym w średniej skali czasu. Jest to jeden ze składowych elementów Inteligentnej Hierarchicznej Struktury Sterowania opracowanej w celu pokonania następujących problemów, które występują w kontrolowanym systemie: różne skale czasowe procesów, silnie...
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Highly Dissipative Materials for Damage Protection against Earthquake-Induced Structural Pounding
PublicationIt is a common situation that seismic excitations may lead to collisions between adjacent civil engineering structures. This phenomenon, called earthquake-induced structural pounding, may result in serious damage or even the total collapse of the colliding structures. Filling the gap between two buildings erected close to one another by using visco-elastic materials can be considered to be one of the most effective methods to avoid...
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NEW EXPERIENCES IN DIKE CONSTRUCTION WITH SOIL-ASH COMPOSITESAND FINE-GRAINED DREDGED MATERIALS
PublicationThe supporting structure inside a coastal dike is often made of dredged non-uniform sand with good compaction proper-ties. Due to the shortage of natural construction material for both coastal and river dikes and the surplus of different processed mate-rials, new experiments were made with sand-ash mixtures and fine-grained dredged materials to replace both dike core and dikecover materials resulting in economical, environmentally...
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Salt melt synthesis of curved nitrogen-doped carbon nanostructures: ORR kinetics boost
PublicationImplementing metal-free electrocatalysts for the oxygen reduction reaction (ORR) and revealing crucial chemical or topographical parameters driving their activity are vital for the development of power cells. The carbon-based catalysts are very often synthesized through carbonization of biopolymers, in particular, those one containing nitrogen groups such as chitosan. Unfortunately, the resulting carbonaceous materials usually...
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Experimental research on technical fabric of the Forest Opera Roof in Sopot
PublicationThe experimental analysis of the technical fabric Valmex is presented. The study involves uniaxial tensile, cyclic, rheological and biaxial tests. Some of the main differencies between two types of the analysed material have been identified. Mechanical properties of the textile have been modeled by the viscoelastic standard model with quite good effect.
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Stardust - Investigation of Microbes in the Stratosphere
PublicationThe stratospheric microbiome has been investigated several times using the methods of classical microbiology. In this experiment, we have combined them with some novel approaches including whole- metagenome amplification, Maldi TOF mass spectrometry and Sanger DNA sequencing. The results of the experiment may provide the scientists with knowledge about the mechanisms of survivability of microorganisms in stratospheric conditions...
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Strength parameters of polyester reinforced PVC coated fabric after short term creep loading in biaxial mode
PublicationThis study addresses the analysis of tensile strength parameters of the technical fabric VALMEX, which is composed of two orthogonal polyester thread families (named the warp and fill) and both sides PVC coated. The material was firstly subjected to 48-hour biaxial creep loading with the equal stress level in both orthogonal directions of the fabric. The stress levels were established as follows: 4.6 kN/m, 10.4 kN/m, 16.4 kN/m,...
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Experimental research of the effect of face milling strategy on the flatness deviations
PublicationIn this paper the dependencies between face milling strategy of EN AW6082-T6 aluminum alloy samples, with difference thicknesses (6, 8, and 12 mm) and two cold rolling directions, and flatness deviations were presented. Three strategies of milling included different proportions of material removed from both sides of the plates. This approach allowed to control the proportions of residual surface stresses on both sides of the specimens,...
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Novel Cold Crucible Ultrasonic Atomization Powder Production Method for 3D Printing
Publication: A new powder production method has been developed to speed up the search for novel alloys for additive manufacturing. The technique involves an ultrasonically agitated cold crucible installed at the top of a 20 kHz ultrasonic sonotrode. The material is melted with an electric arc and undergoes pulverization with standing wave vibrations. Several different alloys in various forms, including noble and metallic glass alloys, were...
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Application of advanced spectroscopic methods in the assessment of the leachability degree of hazardous elements from the matrix of cellular concretea
PublicationDue to its structure, autoclaved cellular concrete exhibits good insulating properties with relatively high compressive strength values. It is increasingly used in construction because of its economic attractiveness. Autoclaved cellular concrete is mainly used in interior structure layers, and therefore its potential exposure to heavy metal leaching from the matrix may be related to the presence of a high pH medium from other materials...
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Weldability of Underwater Wet-Welded HSLA Steel: Effects of Electrode Hydrophobic Coatings
PublicationThe paper presents the effects of waterproof coatings use to cover electrodes on the weldability of high-strength, low-alloy (HSLA) steel in water. With the aim of improving the weldability of S460N HSLA steel in water, modifications of welding filler material were chosen. The surfaces of electrodes were covered by different hydrophobic substances. The aim of the controlled thermal severity (CTS) test was to check the influence...
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The effect of dehydration/rehydration of bacterial nanocellulose on its tensile strength and physicochemical properties
PublicationBacterial nanocellulose (BNC) is a natural biomaterial with a wide range of biomedical applications. BNC contains 99 % of water which makes it too thick to be used as a bioimplant material. The aim of the work was to determine the effect of the BNC dehydration followed by rehydration on its mechanical and physicochemical properties, in the context of the use of BNC as bio-prostheses in the cardiovascular system. Dehydration involved the...
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Laser induced formation of copper species over TiO2 nanotubes towards enhanced water splitting performance
PublicationWe proposed fast and scalable route where the ordered TiO2 nanotubes coated with thin copper layers were annealed by the laser beam of 355 nm wavelength at different fluencies in the range of 15–120 mJ/cm2. As a result, copper species are integrated with the titania substrate and the formed material exhibits unique optical absorption bands in the visible range. Moreover, X-ray photoelectron spectroscopy analysis reveals the formation...
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A Noded Carbon Emission Tool (NCET) to Measure Embodied Carbon (EC) in Compositional Cementitious Materials
PublicationThe ever evolving modern construction industry is now producing the highest levels of carbon content adversely affecting the construction associated environment. Although, the impact of carbon induced emission is quite large, but still not enough measurable standards and tools to scale these emission are available. This study contributes to the body of knowledge by providing a Grasshopper based definition to calculate the embodied...
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High temperature oxidation behavior of SUS430 SOFC interconnects with Mn-Co spinel coating in air
PublicationIn this study, SUS430 alloy is evaluated for its high temperature corrosion properties as a possible material for interconnects of solid oxide fuel cells (SOFCs). Samples are coated with Mn-Co by commercial physical vapor deposition (PVD) process and oxidized in air for 1250 h at 800 °C. A dense cubic Mn-Co-Fe spinel layer is formed on the surface, showing great effect on corrosion reduction compared with the samples without coating....
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Estimation of fracture toughness and shear yield stress of orthotropic materials in cutting with rotating tools
PublicationThe cutting force is an energetic effect of splitting material, and might be considered from a point of view of modern fracture mechanics. Forecasting of the shear plane angle in cutting broaden possibilities for modelling of the cutting process even for thin uncut chips. Such mathematical model has been developed here for description of the orthotropic materials’ cutting on the base of fracture theory, and includes work of separation...
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Superconductivity in a new intermetallic structure type based on endohedral Ta@Ir7Ge4 clusters
PublicationWe report the observation of superconductivity at a temperature near 3.5 K for the previously unreported compound TaIr2Ge2. In addition to being a superconductor, this material displays a new crystal structure type that contains endohedral clusters, as determined by single-crystal x-ray diffraction structure refinement; the structure is more complex than those of the commonly observed tetragonal 122 intermetallic phases. Despite...
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Structure and electrical properties of Y, Fe-based perovskite mixed conducting composites fabricated by a modified polymer precursor method
PublicationIn this work, samples of Y0.07Sr0.93Ti1-xFexO3-d with 20, 40, 60 and 80 mol% of iron amount were prepared by a low-temperature polymer precursor method. The SEM-EDS analysis proved that analyzed Y0.07Sr0.93Ti1-xFexO3-d samples were composites of two Ti- and Fe-rich perovskite samples. This kind of composite consists of two phases in which one has a good ionic and the other electronic conductivity, which makes such a composite a...
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Corrosion behavior of hydrogen charged super duplex stainless steel welded joints
PublicationThe electrochemical behavior of the weld metal, heat-affected zone (HAZ), and base material of super duplex stainless steel (SDSS) welded joints, made with the application of flux-cored arc welding (FCAW) and submerged arc welding (SAW), were investigated with the use of metallographic examinations (optical microscopy and scanning electron microscopy), potentiodynamic polarization measurements and total hydrogen content determination...
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Preparation and Characterization of Nanomaterial Consisting of Silica Aerogel & Carbon Tested as an Electrode in Non-Aqueous Media Containing Lithium Salt.
PublicationSilica aerogel (SiO2ag) was combined with carbonaceous material in the pyrolysis process of hydrocarbons. The obtained nanocomposite SiO2ag/C was amorphous, partially preserving the porous structure of SiO2ag. The specific surface area changes from 445.6 m2/g for pure SiO2ag to 205.52 m2/g SiO2ag/C. The 29Si MAS-NMR shows a three-dimensional matrix with silicon atoms connected to other silicon atoms by four...
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Dynamic Research of Masonry Vault in a Technical Scale
PublicationThe paper presents preliminary results of dynamic tests of the masonry barrel vault in a technical scale. Experimental studies are intended to identify material properties of homogenized masonry vaults under dynamic loads. The aim of the work is to create numerical models to analyse vault’s dynamic response to dynamic loads in a simplest and accurate way. The process of building the vault in a technical scale is presented in the...
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Effect of isovalent substitution on microstructure and phase transition of LaNb1−xMxO4 (M=Sb, V or Ta; x=0.05–0.3)
PublicationLaNb1−xMxO4 oxides with pentavalent elements of different ionic sizes (M=Sb, Ta and V, x=0.05–0.3) were synthesized by the solid state reaction method. Special interest was devoted to the antimony substituted lanthanum niobate which is a new material in this group. Rietveld analysis of the X-ray diffraction patterns was used to determine the influence of the material composition on unit cell parameters. On the basis of dilatometric...
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Size effect in concrete under splitting tension
PublicationThe size effect is a fundamental phenomenon in concrete materials. It denotes that both the nominal structural strength and material ductility always decrease with increasing element size under tension. In the paper splitting tensile tests on cylindrical concrete specimens with the different diameter were carried out. Two types of the loading strip (plywood board and steel cylinder) were used. The concrete strength and ductility...
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Morphology of damage inflicted on brittle polymer in lubricated contact under cyclic static load
PublicationIn this article morphology of damage inflicted on the polymethylmethacrylate (PMMA) plate in static point lubricated contact with a ball made of five different materials under cyclic normal load has been presented. It is argued that the counterface material and lubricating film play an important role in the damage process and the extent of damage inflicted in the PMMA plate.
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Morse inequalities via Conley index theory
PublicationThe relation known as the Morse inequalities can be extended to a more general setting of flows on a locally compact metric spaces (Conley index) as well as dynamical systems on Hilbert spaces (LS-index). This paper is a discourse around this extension. Except the part concerning the LS-index the material is self-contained and has a character of a survey.
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Methods of solving the Atkins equation determine shear angle with taking into consideration a modern fracture mechanics
PublicationIn the paper are presented methods of solving nonlinear Atkins equation . The Atkins equation describe shear angle with taking into account properties of material cutting. To solve Atkins equation has been used iterative methods: Newton method and simplified method of simple iteration. Method of simple iteration is presented in the form of Java application.
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PRZESTRZEŃ PUBLICZNA MIASTA EUROPEJSKIEGO– SALON MIEJSKI CZY ISTOTNY ELEMENT BUDOWYPROGRAMU REWITALIZACJI? PRZYKŁAD MQW WIEDNIUEUROPEAN PUBLIC SPACE – SHOWROOM ORAN IMPORTANT ELEMENT OF REVITALIZATIONPROGRAMME?
PublicationPrzedmiotem artykułu jest próba odpowiedzi na pytanie, jakie miejsce weuropejskich programach rewitalizacji zajmuje obecnie przestrzeń publiczna iczy istotnie jest jego główną składową. Czy miejskość przestrzenipublicznej, która jest jakością miejsc niezwykłych, łączących w sobie kontekst polityczny wswojej materialnej formie tzw.material urbanity[2, s. 24]) jest brana pod uwagę przy programach rewitalizacji?! Czy wreszcie,mówiąc...
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The study on possibilities of recovery non-magnetic fraction by utilisation the magnetic separation technology in conditions of KGHM Polska Miedz S.A. division of concentrators = Próby odzysku frakcji niemagnetycznej metodą separacji magnetycznej w warunkach KGHM Polska Miedź S.A. Oddział Zakłady Wzbogacania Rud
PublicationW referacie przybliżono wyniki badań prowadzonych w kierunku określenia możliwości odzysku frakcji niemagnetycznej i słabomagnetycznej ze strumieni materiałowych O/ZWR, poprzez wykorzystanie metody separacji magnetycznej. Przeprowadzony cykl badawczy obejmował analizę występowania frakcji magnetycznej i związanej z nią frakcji niemagnetycznej w obiegach technologicznych w Rejonie ZWR Lubin, oraz możliwości ich odzysku. Uzyskane...
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Techniki chromatografii w rozdzielaniu i oznaczaniu ekdysteroidów w Rhaponticum carthamoides
PublicationRhaponticum carthamoides to syberyjska endemiczna wieloletnia bylina, od wieków wykorzystywana w medycynie ludowej, jako preparat wzmacniający organizm. Główną grupą związków chemicznych, występujących w roślinie oraz wzbudzających szczególne zainteresowanie, ze względu na wykazywaną aktywność, są ekdysteroidy. Dlatego też poznanie ich dokładnego składu oraz stężeń w tkankach roślinnych staje się istotnym elementem poznawczym oraz...
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On Non-holonomic Boundary Conditions within the Nonlinear Cosserat Continuum
PublicationWithin the framework of the nonlinear micropolar elastic continuum we discuss non-holonomic kinematic boundary conditions. By non-holonomic boundary conditions we mean linear relations between virtual displacements and virtual rotations given on the boundary. Such boundary conditions can be used for modelling of complex material interactions in the vicinity of the boundaries and interfaces.
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Materiały dla jednowarstwowych ogniw paliwowych
PublicationA composite material, which may be further applied as a single layer fuel cell, was synthesizes using solid state synthesis method. Composite consisted of two components. The first was a nanoeramic proton conductor - calcium doped lanthanum niobate. The second one was a nanoceramic semiconductor oxide composed of lithium, nickel and zinc oxides respectively.
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Strong ellipticity within the Toupin–Mindlin first strain gradient elasticity theory
PublicationWe discuss the strong ellipticity (SE) condition within the Toupin–Mindlin first strain gradient elasticity theory. SE condition is closely related to certain material instabilities and describes mathematical properties of corresponding boundary-value problems. For isotropic solids, SE condition transforms into two inequalities in terms of five gradient-elastic moduli.
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MnCo2O4 deposited by spray pyrolysis as a protective layer for stainless steel interconects
PublicationStainless steel interconnects working in Solid Oxide Fuel Cells stacks are exposed to high temperature resulting in their corrosion. Protective layers for the hydrogen and oxygen sides are necessary to protect the interconnect material, prolongate the stack lifetime and maintain the output power. In this paper MnCo2O4 protective layer for the oxygen side of the interconnect is deposited by spray pyrolysis and is examined.
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Load Testing of GFRP Composite U-Shape Footbridge
PublicationThe paper presents the scope of load tests carried out on an innovative shell composite footbridge. The tested footbridge was manufactured in one production cycle and has no components made from materials other than GFRP laminates and PET foam. The load tests, performed on a 14-m long structure, were the final stage of a research program in the Fobridge project carried out in cooperation with: Gdańsk University of Technology (leader),...
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Analiza oddziaływań w kryształach związków zawierających w strukturze pierścień pirydynowy
PublicationMożliwość tworzenia się wiązań wodorowych jest kluczowym parametrem z punktu widzenia inżynierii kryształu, ponieważ wiązania wodorowe mają bezpośredni wpływ na strukturę oraz trwałość sieci krystalicznej. Głównym celem niniejszej rozprawy doktorskiej była analiza porównawcza wiązań wodorowych występujących w układach, zawierających w strukturze pierścień pirydynowy. Badane układy podzielono na: (1) układy ze związkami krzemosiarkowymi...
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Modification of titanium dioxide with platinum ions and clusters: application in photocatalysis
PublicationW celu polepszenia właściwości fotokatalitycznych, TiO2 (komercyjny-P25 oraz syntezowany metoda zol-żel) był domieszkowany za pomocą jonów lub klasterów [Pt3(CO)6]62- platyny. Własności fizyczne fotokatalizatorów były badane za pomocą elektronowego mikroskopu transmisyjnego (TEM), dyfraktometru rentgenowskiego (XRD) oraz analizatora powierzchni właściwej (BET). Dyfuzyjna spektrometria odbiciowa (DRS) została zastosowana w celu...
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Diagnostyka metodą magnetyczną stanu naprężeń w złączu spawanym ze stali dupleks
PublicationStan naprężeń własnych w doczołowych złączach spawanych ze stali dupleks (typ 2205) i stali austenitycznej (typ A316L) zbadano wykorzystując efekt Barkhausena. Badania wykonano dla trzech typów ukosowania spawanych obszarów (1 - kształt Y, 2 - kształt 2Y oraz 3 - kształt I). W przypadku kształtu Y spawanie wykonano z warunkiem limitu energii (przypadek 1a) oraz bez ograniczeń energetycznych (przypadek 1b). Kalibracje naprężeniową...
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Context sensitive privacy management in a distributed environment
PublicationArtykuł przedstawia mechanizm zarządzania prywatnością stworzony dla systemu rozproszonego z założeniem, że węzły systemu mają ograniczone zasoby (moc procesora, pamięć). Podstawowy pomysł zakłada, że prywatne dane są filtrowane zgodnie z polityką prywatności użytkowników przed ich ujawnieniem innym użytkownikom. Te decyzje są silnie umiejscowione, co ogranicza narzut związany z zarządzaniem prywatnością na węzłach systemu. Sam...
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Charakterystyka podatku od zysków kapitałowych w Polsce na tle innych krajów Unii Europejskiej i możliwości jego ograniczania
PublicationPodatek od dochodów z kapitałów pieniężnych jest instrumentem, który silnie oddziałuje na inwestorów, szczególnie w okresie ekspansji i rozwoju rynku kapitałowego. Dlatego też postuluje się wprowadzenie zmian, mających na celu jego ograniczenie, lub też całkowite zniesienie. Interesujące w tym względzie jest porównanie charakterystyk tego podatku w Polsce i pozostałych krajach Unii Europejskiej.W zdecydowanej większości państw...
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Kalibracja i walidacja metody Mathara za pomocą Metody Elementów Skończonych
PublicationMetoda pomiaru naprężeń powierzchniowych przy pomocy rozet tensometrycznych i kontrolowanych odwiertów (metoda otworkowa) jest stosowana powszechnie w odniesieniu do stali izotropowych oraz silnie anizotropowych laminatów, natomiast nie została rozpoznana jej stosowalność do umiarkowanie anizotropowych stopów metali. W artykule opisane jest odniesienie wyników pomiarów wykonanych na płytach ze stali duplex do modelu numerycznego...
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Zastosowanie chromatografii żelowej (chromatografii wykluczania) w badaniach polimerów
PublicationZastosowanie chromatografii żelowej (GPC)/chromatografii wykluczenia (SEC) w badaniach polimerów i substratów stosowanych w ich syntezie, pozwala na wyznaczenie średniej wagowo i liczbowo masy cząsteczkowej, a także stopnia polidyspersyjności (PD). Są to niezmiernie istotne informacje, kluczowe na etapie planowania syntezy polimeru, w tym także modelowania zespołu właściwości użytkowych wyrobów otrzymywanych z ich udziałem. Praktyczne...