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Search results for: SHIP STRUCTURE WELDING
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Multi-layered mineral glass units used as viewport elements of underwater ship structures
PublicationIn the paper, Authors deals with viewport elements of underwater marine constructions. If a single-plate viewport constructions are considered, big thicknesses of the glass plate are required to resist the pressure. To build the viewports from the commercially accessible glass panes, multi-layered glass units are proposed in the paper. Numerical calculations are presented, summarized and compared with experimental tests. Focusing...
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The Impact of Material Selection on Durability of Exhaust Valve Faces of a Ship Engine – A Case Study
Publicationwo alloys were used in order to extend the service life of marine engine exhaust valve head. Layers of cobalt base alloys were made of the powders with with chemical composition as follow: the layer marked L12; C-1,55%; Si-1,21%; Cr-29,7%; W-9%; Ni-2%; Mo<0,01%; Fe-1,7%; Co-54,83% and the layer marked N; C-1,45%; Co-38,9%; Cr-24,13%; Ni-10,43%; W-8,75%; Fe-7,64%; Mo-7,56%; Si-2,59%. Base metal was valve steel after heat treatment....
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Impact of the Time Window Length on the Ship Trajectory Reconstruction Based on AIS Data Clustering
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Elastic protection coating for ship fuel tanks, intended for the increasing of environment protection level
PublicationW opracowaniu przedstawiono problemy związane z wprowadzeniem nowego rozwiązania dla podniesienia bezpieczeństwa zbiorników paliwowych, poprzez zainstalowanie we wnętrzu zbiornika drugiej elastycznej bariery ochronnej opartej na warstwie wypełniacza. Przedstawiono wyniki prac związanych z doborem parametrów warstwy drugiej bariery jak również materiału wypełniacza.
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A decision-making module for aiding ship system automation design; A knowledge-based approach
PublicationZastosowanie elementów sztucznej inteligencji, w tym systemów z bazą wiedzy staje się coraz bardziej powszechne przy komputerowo wspomaganym projektowaniu. Proces projektowy związany jest z wieloma problemami decyzyjnymi, jak: wybór struktury podsystemu, podzespołów czy też elementów składowych. Z tego względu zdecydowano się opracować system z bazą wiedzy z modułem wspirającym proces podejmowania decyzji.W artykule przedstawiono...
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Influence of main design parameters of ship propeller shaft water-lubricated bearings on their properties
PublicationW artykule omówiono wpływ głównych parametrów konstrukcyjnych i eksploatacyjnych takich jak wielkość luzu łożyskowego, własności materiału panwi, stanu powierzchni skojarzenia ślizgowego oraz temperatury i zasolenia wody na nośność hydrodynamiczną łożyska okrętowego wału śrubowego smarowanego wodą.
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NOx emission from a two-stroke ship engine: Part 2 – Laboratory test
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NOx emission from a two-stroke ship engine. Part 1: Modeling aspect
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A design concept of main propulsion system with hydrostatic transmission gear for inland waterways ship
PublicationCelem analizy jest przedstawienie koncepcji napędu głównego statku oraz określenie jego sprawności całkowitej. Zrealizowanie zamierzenia przedstawionego powyżej wymaga spojrzenia na opis strat i sprawności energetycznej przekładni hydrostatycznej, uwzględniający jak najdalej idącą jego prostotę. Obraz wzajemnego wpływu strat we wszystkich elementach układu hydraulicznego okazuje się bardzo złożony. Przy założeniu koniecznych uproszczeń...
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Water-lubricated bearings of ship propeller shafts - problems, experimental tests and theoretical investigations
PublicationW pracy przedstawiono problemy związane z projektowaniem, montażem i ekspolatcją smarowanych wodą łożysk okrętowych wałów głównych.Przedstawiono wyniki prowadzonych prac badawczych ekperymntalnych i obliczeń.
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Damage tests of the single shell ship fuel tank with additional elastic protective coating
PublicationWejście na mieliznę lub kolizja średniej wielkości np. kontenerowca może doprowadzić do zanieczyszczenia środowiska Morza Bałtyckiego paliwem uwolnionym z rozszczelnionych, jednoposzyciowych zbiorników dennych, a ilość tego paliwa może być znaczna. W związku z tym podjęto prace badawcze zmierzające do opracowania sposobu obniżenia ryzyka rozlewu paliwa w wypadku kolizji poprzez wprowadzenie drugiej bariery ochronnej. Idea pomysłu...
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Expert elicitation of a navigation service implementation effects on ship groundings and collisions in the Gulf of Finland
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Enhancing human performance in ship operations by modifying global design factors at the design stage
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Safety Qualification Process for an Autonomous Ship Prototype – a Goal-based Safety Case Approach
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Changing the Ship Propulsion System Performances Induced by Variation in Reaction Degree of Turbocharger Turbine
PublicationArtykuł przedstawia szczegółowy model matematyczny układu napędu statku obejmującego: wolnoobrotowy silnik spalinowy okrętowy, śruba okrętowa oraz regulator prędkości kątowej. Model ten, następnie jest wykorzystany do badania symulacyjnego zachowania układu zarówno w stanach ustalonych jak i nieustalonych. Model jest zweryfikowany z wynikami eksperymentalnymi. Przedstawienie oryginalnej metody oceny wrażliwości układu względem...
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Semi-Markow Processes as Models of Devices´ Operating Process of Ship Pro-pulsion System
PublicationReferat zawiera formalny opis procesu eksploatacji urządzeń.
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Design and experimental evaluation of pod propulsor models for a large self-propelled ship model.
PublicationArtykuł przedstawia serię hydrodynamicznych badań swobodnych dwóch modeli pędnika podowego. Pędniki zostały zaprojektowane i zbudowane specjalnie dla dwóch wersji dużego modelu okrętu z własnym napędem, przeznaczonego do eksperymentów manewrowych. Jedna wersja jest napędzana pojedyńczym pędnikiem, druga jest wyposażona w dwa pędniki. Oba modele podów były badane w kanale obiegowym. Celem eksperymentu były pomiary sześciu składowych...
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Computer graphics toos application for visualsation of measurements results of ship hull sections and blocks.
PublicationOpisano zakres minimalnych wymagań dla programu komputerowego, służącego do wizualizacji wyników pomiarów sekcji i bloków kadłuba okrętowego. Przedstawiono sposób przenoszenia danych z urządzenia pomiarowego do programu i pokazano przykłady pomiarów wykonanych na sekcjach zbudowanych w Stoczni Gdynia S.A.
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On a risk-based method for safety assessment of a ship in critical conditions at the preliminary design stage.
PublicationW pracy przedstawiono wybrane rezultaty badań na temat metody oceny bezpieczeństwa statków w warunkach krytycznych, na etapie projektu wstępnego. Podano główne założenia nowoczesnego podejścia do oceny bezpieczeństwa statków. Przedstawiono opis metody do projektowania statków dla bezpieczeństwa, w warunkach krytycznych. Opisano główne elementy modelu obliczeniowego. Podano wybrane wyniki obliczeń. Opisano propozycje dalszych badań.
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Multifaceted Analyses of Four Different Prototype Lightweight Photovoltaic Modules of Novel Structure
PublicationDynamic growth of photovoltaic capacity in Poland encourages many entities to invest in photovoltaic systems. However, in the case of buildings with low roof-bearing capacity it can be problematic or even impossible to mount conventional PV modules due to their relatively high weight. Hence, the use of lightweight PV modules is a potential solution. In this paper four different prototype silicon lightweight modules of novel structure...
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Mechanical Design, Construction and Control of a Lower Extremity Exoskeleton Robot Prototype with a new structure in the form of three-wheeled Mobile robot
PublicationIn this paper, mechanical design, dynamic modeling, construction and Fuzzy computed torque control of a lab prototype of lower extremity exoskeleton robot with a new structure in the form of three-wheeled Mobile robot is presented. One of the most important applications of next generation of lower extremity exoskeleton robot is usability as smart vehicle. In order to autonomously moving of this robot which is the foundation...
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High performance super-twisting sliding mode control for a maritime autonomous surface ship (MASS) using ADP-Based adaptive gains and time delay estimation
PublicationThis research addresses two kinds of problems related to optimal trajectory tracking of a Maritime Autonomous Surface Ship (MASS): those caused by the time-varying external disturbances including winds, waves and ocean currents as well as those resulting from inherent dynamical uncertainties. As the paper shows, an accurate and robust optimal controller can successfully deal with both issues. An improved Optimal Adaptive Super-Twisting...
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High performance super-twisting sliding mode control for a maritime autonomous surface ship (MASS) using ADP-Based adaptive gains and time delay estimation
PublicationThis research addresses two kinds of problems related to optimal trajectory tracking of a Maritime Autonomous Surface Ship (MASS): those caused by the time-varying external disturbances including winds, waves and ocean currents as well as those resulting from inherent dynamical uncertainties. As the paper shows, an accurate and robust optimal controller can successfully deal with both issues. An improved Optimal Adaptive Super-Twisting...
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Architecture of security and application layer structure of radio system for monitoring and acquisition of data from traffic enforcement cameras
PublicationThe study presents architecture of security and application layer structure of Radio System for Monitoring and Acquisition of Data from Traffic Enforcement Cameras. It also provides general assumptions concerning the range of the system as well as its modules and application components.
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Numerical evaluation of dynamic response of an experimentally tested base-isolated and fixed-base steel structure model
PublicationSeismic isolation is recognized as one of the most popular and effective methods of protecting structures during earthquake. The present paper is focused on the comparison be-tween the dynamic responses of buildings with fixed and isolated bases exposed to seismic exci-tations. The aim of the study is to investigate the effectiveness of a simplified base isolation numerical modelling technique using the linear springs. One-storey...
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Study on the Structure-Property Dependences of Rigid PUR-PIR Foams Obtained from Marine Biomass-Based Biopolyol
PublicationThe paper describes the preparation and characterization of rigid polyurethane-polyisocyanurate (PUR-PIR) foams obtained with biopolyol synthesized in the process of liquefaction of biomass from the Baltic Sea. The obtained foams differed in the content of biopolyol in polyol mixture (0–30 wt%) and the isocyanate index (IISO = 200, 250, and 300). The prepared foams were characterized in terms of processing parameters (processing...
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High-conducting Bi4V2-xFexO11-δ ceramics containing Fe2O3 nanocrystals: Structure and properties
PublicationThe topography, structure, thermal, magnetic, and electrical properties of Bi4V2-xFexO11-δ ceramics substituted with x = 0.5 and 0.7 Fe were studied. The microscope analysis showed the presence of iron-rich nanocrystals formed on the Bi-Fe-V-O grains. The X-ray diffraction studies confirmed that grains are built mostly of tetragonal Bi4V1.5Fe0.5O10.5 phase. Thermal properties analysis showed an order-disorder type γ ↔ γʹ phase...
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Effect of hydroxylated soybean oil and bio-based propanediol on the structure and thermal properties of synthesized bio-polyurethanes
PublicationThe aim of this work was to obtain bio-polyurethanes using synthetic compounds and bio-components, i.e. bio-glycols. Bio-polyurethanes were prepared by means of the prepolymer method. Prepolymers were synthesized from 4,4′-diphenylmethane diisocyanate (MDI) and a polyol mixture containing 75% by weight of commercial polyether and 25% by weight of hydroxylated soybean oils (H2 or H3), the latter being obtained in the reaction with...
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Prediction of protein structure with the coarse-grained UNRES force field assisted by small X-ray scattering data and knowledge-based information
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Effect of chemical structure on complexation efficiency of aromatic drugs with cyclodextrins: The example of dibenzazepine derivatives
PublicationIt is widely believed that the hydrophobic effect governs the binding of guest molecules to cyclodextrins (CDs). However, it is also known that high hydrophobicity of guest molecules does not always translate to the formation of stable inclusion complexes with CDs. Indeed, a plethora of other factors can play a role in the efficiency of guest–CD interactions, rendering structure-based prediction of the complexation efficiency with...
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Green thermoplastic poly(ether-urethane)s – synthesis, chemical structure and selected properties investigation
PublicationThis work aimed to characterize the effect of the monomers chemical structure on the selected properties of the green thermoplastic poly(ether-urethane)s. During synthesis two types of polyether biopolyols, 4,4′-diphenylmethane diisocyanate and bio-based 1,3-propanediol were employed. Materials were synthesized with the use of two step method and two different prepolymers, which were mixed together in equimolar quantities. Obtained...
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Fe local structure in Pt-free nitrogen-modified carbon based electrocatalysts: XAFS study
PublicationThe paper presents a new results on the bonding environment (coordination number and geometry) and on oxidation states of Fe in nitrogen-modified Fe/C composites used as Pt-free catalysts for oxygen reduction in Direct Hydrogen Fuel Cells. Starting from glucose or fructose, two catalysts displaying different electrochemical performance were prepared and studied in the form of pristine powder and thin catalytic layer of electrode...
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Design of Structure of Tension Leg Platform for 6 MW Offshore Wind Turbine Based On Fem Analysis
PublicationThe article presents the calculation and design stages of the TLP platform serving as a supporting construction of a 6 MW offshore wind turbine. This platform is designed to anchor at sea at a depth of 60 m. The authors presented the method of parameterization and optimization of the hull geometry. For the two selected geometry variants, the load and motion calculations of the platform subjected to wind, wave and current under...
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From Structure to Luminescent Properties of B2O3-Bi2O3-SrF2 Glass and Glass-Ceramics Doped with Eu3+ Ions
PublicationGlass-ceramics with the composition B2O3 -Bi2O3 -SrF2 were synthesized by the conventional melt-quenching technique and subsequent crystallization of the parental glasses. The temperature at which the ceramization was carried out was selected based on differential scanning calorimetry (DSC) analysis. The structure of the studied materials and the formation of SrF2 nanocrystals were confirmed by the Fourier-transform infrared spectroscopy...
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Charge-assisted N(+)–H···(−)S hydrogen bonds in the crystal structure of selected diammonium thiophenolates.
PublicationNew salts of thiophenol with three flexible aliphatic diamines H2N(CH2)nNH2 (n = 2, 4 and 6) have been synthesized and characterized by elemental analyses, IR spectroscopy and X-ray crystallography in order to analyze their supramolecular architecture. Structural analyses indicate that in the crystals, proton transfer has occurred, with the –SH group giving (+)N–H···S(−) hydrogen bonding interaction. The structure of compound 1...
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Structure and hyperfine interactions in Bi1−xNdxFeO3 solid solutions prepared by solid-state sintering
PublicationThe series of polycrystalline ceramic powders, Bi1xNdxFeO3 (x = 0.11) was successfully synthesized by mixed oxide method followed by pressureless sintering. X-ray diffraction and Mössbauer spectroscopy were used as complementary methods to study structure and hyperfine interactions of the samples. It was found that with an increase of Nd content, within the range of x = 0.20.3 a structural phase transition from rhombohedral to...
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Short-range order structure and free volume distribution in liquid bismuth: X-ray diffraction and computer simulations studies
PublicationThe structure of liquid bismuth was studied by X-ray diffraction and computer simulation methods. The contraction of the atomic structure within the first coordination sphere in the temperature interval of 575- 1225 K is reported. The temperature dependencies of the coordination numbers and of the free volume are analysed. On the basis of the temperature dependencies of the free volume, the temperature dependencies of viscosity...
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The analysis of the influence of the corrosion protection method of selected steel elements on the steel structure life cycle costs
PublicationSteel products are widely used in the construction for the performance of essential and additional elements of engineering structures. They are characterized by high tensile strength, compression and bending, the structure homogeneity, the possibility of assembly regardless of the season and climatic conditions, ease of processing and the possibility of almost any shape. The main disadvantage of steel structures is their high susceptibility...
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Effect of bio-polyol molecular weight on the structure and properties of polyurethane-polyisocyanurate (PUR-PIR) foams
PublicationThe increasing interest in polyurethane materials has raised the question of the environmental impact of these materials. For this reason, the scientists aim to find an extremely difficult balance between new material technologies and sustainable development. This work attempts to validate the possibility of replacing petrochemical polyols with previously synthesized bio-polyols and their impact on the structure and properties...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston pump
PublicationA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Effect of Nb and Al on in vitro dissolution behavior and structure of Na2O-MgO CaO-P2O5 glasses
PublicationIn vitro dissolution, structure, and thermal properties of the glass series Na2O-MgOsingle bondCaOsingle bondNb2O5 -Al2O3-P2O5 were studied. The dissolution behavior in phosphate-buffered saline (PBS) confirmed the potential bioactive properties of tested glasses. The dissolution process was found to depend on the Al, Nb, and Mg contents. Al, respectively, suppresses the Nb and accelerates the Mg release process from the glasses....
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The effect of Sr and Mg substitutions on structure, mechanical properties and solubility of fluorapatite ceramics for biomedical applications
PublicationIonic substitutions play important role in the modifications of biological apatites. Recently, attention has been focused on the co-doping effects on the functional properties of apatite-based biomaterials. In this research work, the dense samples of fluorapatites, Ca10(PO4)6F2 and Ca8MgSr(PO4)6F2, were produced after sintering at 1250 °C for 6 h in air. Structural characterization carried out with XRD, IR, Raman and SEM, confirmed...
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Chemical structure, thermal and mechanical characterization of bio-based polyurethane composites filled with microcrystalline cellulose
PublicationOver the past several decades, the interest in replacing the synthetic components used in the production of polymers and composites with their natural counteparts has been growing. Biocomposites belong to the group of materials produced with the use of renewable raw materials. There has been a recent surge of interest in the industrial applications of composites containing natural fibres reinforced with biopolymers. Biopolymers...
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Polypropylene structure alterations after 5 years of natural degradation in a waste landfill
PublicationUp to 25% of plastic waste in Europe is still disposed of in landfills, despite recycling efforts. The plastic waste in the landfill plot may be exposed both to abiotic and biotic degradation processes, although it is thought that most of the plastic materials tend to be resistant to biodegradation or biodeterioration even after a long time. To verify if polypropylene (PP) can undergo the process of short-term biodegradation and...
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The valance state of vanadium-key factor in the flexibility of potassium vanadates structure as cathode materials in Li-ion batteries
PublicationPotassium hexavanadate (K2V6O16·nH2O) nanobelts have been synthesized by the LPE-IonEx method, which is dedicated to synthesis of transition metal oxide bronzes with controlled morphology and structure. The electrochemical performance of K2V6O16·nH2O as a cathode material for lithium-ion batteries has been evaluated. The KVO nanobelts demonstrated a high discharge capacity of 260 mAh g−1, and long-term cyclic stability up to 100...
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Modification of cellulosic filler with diisocyanates – volatile organic compounds emission assessment and stability of chemical structure over time
PublicationThis paper investigated the impact of type and content of diisocyanate on the structure of modified cellulose fillers. Four the most popular isocyanates were applied – isophorone, hexamethylene, toluene and methylene diphenyl diisocyanate – at loadings of 1–15 wt%. Chemical structure, and its short-term storage stability, were investigated for eight weeks. Moreover, the main volatile organic compounds detected during modification,...
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Structure and properties of the exopolysaccharides produced by Pseudomonas mutabilis T6 and P. mutabilis ATCC 31014
PublicationThis paper presents a study on the purification, primary structure, and rheological properties of exopolysaccharides isolated from cultures of Pseudomonas mutabilis T6 and P. mutabilis ATCC 31014. Both polymers are exopolysaccharides of D-mannose. The mannan isolated from P. mutabilis T6 contains on average about 5% of residual b-D-glucose, in contrast to the mannan from P. mutabilis ATCC 31014, which contained only trace amounts...
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The effect of calcination temperature on structure and photocatalytic properties of Au/Pd nanoparticles supported on TiO2
PublicationBimetallic nanoparticles, composed of two different metal elements, can exhibit peculiar electronic, optical, and catalytic or photocatalytic properties that are absent in the corresponding monometallic nanoparticles. We show the effect of calcination temperature (from 350 to 700°C) on the structure and the photocatalytic properties of Au/Pd-modified TiO2. The composition of the bimetallic Au/Pd nanoparticles in relation to their...
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Complexes of silanethiolate ligands: Synthesis, structure, properties and application
PublicationThe purposeful syntheses of silanethiolate complexes started approximately in the mid-eighties of the 20th century but no summary of the synthetic efforts has been reported till now. The synthetic methods and the resulting complexes have some common features, which are emphasized throughout the review. Thereby specific difficulties during synthesis are outlined and the structures, properties and possible applications of the resulting...
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Conductivity, structure, and thermodynamics of Y2Ti2O7–Y3NbO7 solid solutions
PublicationThe defect fluorite yttrium niobate Y3NbO7 and pyrochlore yttrium titanate Y2Ti2O7 solid solutions have been synthesized via a solid state synthesis route. The resulting stoichiometry of the oxides is Y2+xTi2−2xNbxO7, where x = 0 to x = 1. All of the samples were single-phase; however, for those with a predominant fluorite phase, a small amount of additional pyrochlore phase was detected. The volume of the solid solution unit cells...