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Wyniki wyszukiwania dla: protonic ceramics
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The Effect of Sodium Tetrafluoroborate on the Properties of Conversion Coatings Formed on the AZ91D Magnesium Alloy by Plasma Electrolytic Oxidation
PublikacjaMagnesium and its alloys are widely used in many areas because of their light weight, excellent dimensional stability, and high strength-to-weight ratio. However, the material exhibits poor wear and corrosion resistance, which limits its use. Plasma electrolytic oxidation (PEO) is an effective surface modification method for producing ceramic oxide layers on Mg and their alloys. The influence of the additions of sodium tetrafluoroborate...
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Design of an Autonomous IoT Node Powered by a Perovskite-Based Wave Energy Converter
PublikacjaThis paper presents the results of experimental research focused on wave energy harvesting and its conversion to power Internet of Things (IoT) devices. The harvesting and conversion process was performed using a wave energy converter (WEC) consisting of a lead zirconate titanate piezoelectric ceramic perovskite material and a prototype power electronic circuit. The designed WEC was considered as a power supply for an end node...
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Potentiometric Oxygen Sensor with Solid State Reference Electrode
PublikacjaThe concentration or the partial pressure of oxygen in an environment can be determined using different measuring principles. For high temperature measurements of oxygen, ceramic-based sensors are the most practical. They are simple in construction, exploration and maintenance. A typical oxygen potentiometric sensor consists of an oxygen ion conducting solid electrolyte and two electrodes deposited...
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Organic light sources look forward to optimize the photosynthesis process
PublikacjaW pracy opisano własności organicznej diody EL, zbudowanej na bazie organicznego kompleksu platyny, emitującej światło czerwone i niebieskie, które może być wykorzystane w procesie fotosyntezy.
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DEM ANALYSIS OF EFFECT OF INTERFACIAL TRANSITIONAL ZONES ON FRACTURE IN CONCRETE.
PublikacjaArtykuł omawia wyniki numeryczne dotyczące pękania betonu uzyskane stosując metodę elementów dyskretnych. Trójwymiarowe obliczenia wykonano dla próbek betonowych podczas zginania. Beton został opisany jako model 4-fazowy. Mikrostrukturę betonu przyjęto na podstawie 3D zdjęć mikro-tomograficznych. Zbadano wpływ stref przejściowych na wytrzymałość i proces pękania. Wyniki numeryczne zostały porównane z wynikami doświadczalnymi. Uzyskano...
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INVESTIGATIONS OF QUASI-STATIC VORTEX-STRUCTURES IN 3D SAND SPECIMENS BASED ON DEM AND HELMHOLTZ-HODGE VECTOR FIELD DECOMPOSITION.
PublikacjaArtykuł omawia wyniki numeryczne dotyczące struktur wirowych w materiałach granulowanych w warunkach 3D. Obliczenia wykonano dla ściskania dwuosiowego. W symulacjach wykorzystano metodę elementów dyskretnych i dekompozycję pola wektorowego wg Helmholtza-Hodge’a Struktury wirowe okazały się znakomitym prekursorem lokalizacji odkształceń stycznych w materiałach granulowanych podczas obciążenia.
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Investigations of vortex structures in granular materials under earth pressure conditions by DEM
PublikacjaW artykule pokazano rozwój wirów na poziomie ziarna materiału granulowanego podczas parcia pasywnego piasku na sztywną ściankę przemieszczającą się poziomo. Obliczenia wykonano stosując metodę DEM. Przyjęto 3 różne sposoby wyznaczenia wirów i ich czestotliwości.
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Modelling of concrete facture at aggregate level using DEM based on x-ray mu CT images of internal structure
PublikacjaW artykule pokazano wyniki dyskretne DEM dla pękania betonu poddanego zginaniu. Beton został symulowany jako ośrodek 4-fazowy. Mikrostrukturę betonu określono na podstawie zdjęć uzyskanych mikro-tomografem. Szczególną uwagę zwrócono na zjawiska mikrostrukturalne podczas zarysowania na poziomie kruszywa.
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Investigation of the thermal conductivity of λ gypsum using the hot wire method
Dane BadawczeAn experimental study was conducted to determine the thermal conductivity coefficient λ using the ‘hot wire’ method for a building material. Gypsum specimens measuring 400 x 60 x 50 mm were made for the experiment. Along the long axis of the model, an insulated resistance wire with a diameter of 0.2 mm was poured into the gypsum slurry in the centre...
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Recycling of Industrial Waste as Soil Binding Additives—Effects on Soil Mechanical and Hydraulic Properties during Its Stabilisation before Road Construction
PublikacjaTo improve the in situ soil stabilization, different chemical additives are used (ion exchange compounds, additives based on H2SO4 or vinyl polymers, and organic additives using lignosul- fonates). One interesting alternative is the production of additives from various waste materials. The extensive testing of waste-based blends with soil was performed; the mechanical (unconfined compressive strength (UCS)) and hydraulic (capillary...
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Time-frequency analysis in optical coherence tomography for technical objects examination
PublikacjaOptical coherence tomography (OCT) is one of the most advanced optical measurement techniques for complex structure visualization. The advantages of OCT have been used for surface and subsurface defect detection in composite materials, polymers, ceramics, non-metallic protective coatings, and many more. Our research activity has been focused on timefrequency spectroscopic analysis in OCT. It is based on time resolved spectral analysis...
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Microgrinding with single-disk lapping kinematics.
PublikacjaGrinding operations are carried out with a variety of tool-workpiece configurations. The selection of a grinding process for a particular application depends on part shape, part size, ease of fixture, requirements concerning the acceptable shape errors. It is evident that lapping is very effective in eliminating the waviness while surface grinding is not. Dual disk machines for the double face grinding with planetary kinematics...
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Occurrence and Determination of Volatile Fatty Acids in Landfill Leachate and Gas
PublikacjaIn landfills containing biological matter volatile fatty acids (VFAs) are generated at high rate at the early stage of waste disposal and their content in leachate is high as compared to the leachate from old parts of landfill since they are converted to methane gas. Monitoring of the leachate for the content of VFAs can help determine the processes occurring in waste and possible effect of the leachate on the environment in the...
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Occurrence and Determination of Volatile Fatty Acids in Landfill Leachate and Gas
PublikacjaIn landfills containing biological matter volatile fatty acids (VFAs) are generated at high rate at the early stage of waste disposal and their content in leachate is high as compared to the leachate from old parts of landfill since they are converted to methane gas. Monitoring of the leachate for the content of VFAs can help determine the processes occurring in waste and possible effect of the leachate on the environment in the...
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Optimization of Graphene Oxide Synthesis and Its Reduction
PublikacjaIn this article, we present the review of the chemical methods of synthesis of graphene oxide and its reduction in order to obtain the so-called reduced graphene oxide (rGO) whose properties are similar to those of pure graphene. We also present our experiments and the results in this field and the comparison of the efficiency of different methods of synthesis as well as the reduction of graphene oxide. To characterize the obtained...
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Configurational and Conformational Preferences in Stereoselective Acylations of N-Methyl-1,3-diaminopropane with Acyl Chlorides
PublikacjaEvidence for a stereoinduction profile of the reaction of N-methyl-1,3-diaminopropane with acyl chlorides was provided. A possibility to engage in intramol. CH2···HN and Cl···H-N interactions and the proton migration process to the methylamino group leads to the E secondary amides carrying the N···H+···N or N-H···N bridges, that show unusual spectroscopic images. Empirical relations between the ΔδC chem. shift differences,...
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T1 RELAXATION TIME CALLIBRATION IN MAGNETIC RESONANCE IMAGING USING NANODIAMOND PHANTOMS
PublikacjaMRI is increasingly used in radiation treatment planning because of the excellent soft tissue contrast in the obtained images. It allows more precise definition of the boundaries between healthy tissues and those affected by cancerous lesions. To obtain good image quality, the difference in signal between two types of tissue must be significant despite the noise so it must be properly calibrated. This calibration includes...
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Dissociative electron attachment and anion-induced dimerization in pyruvic acid
PublikacjaWe report partial cross sections for the dissociative electron attachment to pyruvic acid. A rich fragmentation dynamics is observed. Electronic structure calculations facilitate the identification of complex rearrangement reactions that occur during the dissociation. Furthermore, a number of fragment anions produced at electron energies close to 0 eV are observed, that cannot originate from single electron-molecule collisions....
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In Vitro Biological Characterization of Silver-Doped Anodic Oxide Coating on Titanium
PublikacjaDespite the high biocompatibility and clinical effectiveness of Ti-based implants, surface functionalization (with complex osteointegrative/antibacterial strategies) is still required. To enhance the dental implant surface and to provide additional osteoinductive and antibacterial properties, plasma electrolytic oxidation of a pure Ti was performed using a nitrilotriacetic acid (NTA)-based Ag nanoparticles (AgNP)-loaded calcium–phosphate...
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Protective and Suppressing Electromagnetic Interference Properties of Epoxy Coatings Containing Nano-Sized NiZn Ferrites
PublikacjaNano-crystalline ferrites with the chemical formula NixZn(1−x)Fe2O4, where x = 0, 0.2, 0.4, 0.6, 0.8, 1.0, were synthesized using a co-precipitation method. The obtained ferrites were investigated by X-ray diffraction (XRD). The corrosion inhibiting behavior of nano-sized ferrites was tested using carbon steel samples and 10% aqueous ferrite extracts. Results were compared with previous data obtained for micro-sized ceramic ferrites....
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Protein thermal stabilization in aqueous solutions of osmolytes
PublikacjaProteins’ thermal stabilization is a significant problem in various biomedical, biotechnological, and technological applications. We investigated thermal stability of hen egg white lysozyme in aqueous solutions of the following stabilizing osmolytes: Glycine (GLY), N-methylglycine (NMG), N,N-dimethylglycine (DMG), N,N,N-trimethylglycine (TMG), and trimethyl-N-oxide (TMAO). Results of CD-UV spectroscopic investigation were compared...
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Optical low-coherence interferometry for selected technical applications
PublikacjaW artykule przedstawiono teoretyczne podstawy optycznej interferometrii niskokoherentnej i przedyskutowano jej unikatowe właściwości. Opisano w nim opracowany przez autorów system OCT przeznaczony do badań strukturalnych materiałów technicznych. Badania te obejmują także zmiany stanu polaryzacji promieniowania rozproszonego w badanym obiekcie. W artykule zawarto wyniki badań wybranych materiałów silnie rozpraszających promieniowanie...
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Hydrogen migration in formation of NH(A3Π) radicals via superexcited states in photodissociation of isoxazole molecules
PublikacjaFormation of the excited NH(A 3Π) free radicals in the photodissociation of isoxazole (C3H3NO) molecules has been studied over the 14-22 eV energy range using photon-induced fluorescence spectroscopy. The NH(A 3Π) is produced through excitation of the isoxazole molecules into higher-lying superexcited states. Observation of the NH radical, which is not a structural unit of the isoxazole molecule, corroborates the hydrogen atom...
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Cation sensing by diphenyl-azobenzocrowns
PublikacjaMetal cations complexation and proton binding by 13- and 16-membered diphenyl-azobenzocrowns and diphenyl-hydroxyazobenzocrowns were studied in acetonitrile using spectroscopic methods: UV–vis spectroscopy, spectrofluorimetry, and 1H NMR spectroscopy. Phenyl moieties in benzene rings were found to affect binding strength alkali and alkaline earth metal cations and hydrogen ion, and affect tautomeric equilibrium of hydroxyazobenzocrowns....
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Isolation of Citrus lemon extracellular vesicles: Development and process control using capillary electrophoresis
PublikacjaA new and scalable method for the isolation of extracellular vesicles (EV) from Citrus lemon juice samples was developed. The methodology included preliminary preconcentration of the sample using ultrafiltration (UF) followed by size-exclusion chromatography (SEC) purification and final preconcentration of the eluates. Transmission electron microscopy and proteomic analysis showed that isolates contained exosome-like vesicles, exocyst-positive...
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The influence oil additives on spread cracks in silicon nitride
PublikacjaThe paper presents an experimental study of the influence of oil additives (Cl, S, P, cerium dioxide (CeO2)) on spread cracks in silicon nitride. The additives Cl, S, P are bound in molecules in liquid form soluble in the base oil. The CeO2 is purely in powder form in suspension. The use of CeO2 powder was made based on the good results of polishing of silicon nitride. A ceramic angular contact ball bearing was modelled using a...
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Editorial for the special issue on advances in forward and inverse surrogate modeling for high-frequency design
PublikacjaThe design of modern‐day high‐frequency devices and circuits, including microwave/RF, antenna and photonic components, historically has relied on full‐wave electromagnetic (EM) simulation tools. Initially used for design verification, EM simulations are nowadays used in the design process itself, for example, for finding optimum values of geometry and/or material parameters of the structures of interest. In a growing number of...
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A XAS study of a highly diluted Pt electrocatalyst operating in PEM fuel cells
PublikacjaWe present an X-ray absorption spectroscopy (XAS) study of a low Pt content catalyst layer(Pt loading 0.1 mg c2) operating at the cathode of a proton exchange membrane fuel cell(PEMFC). This catalyst is based on the use of a mesoporous inorganic matrix as a support forthe catalyst Pt nanoparticles. Due to the high Pt dilution, in situ measurements of itsstructural properties by XAS are challenging and suitable experimental strategies...
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Nowe rozwiązania metodyczne w zakresie badań oddechu stosowane w diagnostyce medycznej
PublikacjaSkład wydychanego powietrza zależny jest od stanu zdrowia pacjentów, dzięki czemu możliwe jest wykorzystanie analizy oddechu do celów diagnostycznych. Badanie oddechu może zostać użyte do oceny funkcjonowania narządów człowieka, a także do rozpoznania chorób, takich jak przewlekła obturacyjna choroba płuc, cukrzyca czy gruźlica. W artykule przedstawiono obecnie stosowane próbniki próbek oddechu, a także możliwość zastosowania nowych...
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Damage detection in 3D printed plates using ultrasonic wave propagation supported with weighted root mean square calculation and wavefield curvature imaging
Publikacja3D printing (additive manufacturing, AM) is a promising approach to producing light and strong structures with many successful applications, e.g., in dentistry and orthopaedics. Many types of filaments differing in mechanical properties can be used to produce 3D printed structures, including polymers, metals or ceramics. Due to the simplicity of the manufacturing process, biodegradable polymers are widely used, e.g., polylactide (polylactide...
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Rotation Triggers Nucleotide-Independent Conformational Transition of the Empty β Subunit of F1-ATPase
PublikacjaF1-ATPase (F1) is the catalytic portion of ATP synthase, a rotary motor protein that couples proton gradients to ATP synthesis. Driven by a proton flux, the F1 asymmetric γ subunit undergoes a stepwise rotation inside the α3β3 headpiece and causes the β subunits’ binding sites to cycle between states of different affinity for nucleotides. These concerted transitions drive the synthesis of ATP from ADP and phosphate. Here, we study...
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pH-tunable equilibria in azocrown ethers with histidine moieties
PublikacjaEtery koronowe posiadające elektro- i fotoaktywne reszty azowe oraz ugrupowania z ruchliwymi protonami jak w grupie COOH histydyny charakteryzują się unikalnym, zależnym od pH, efektem stymulowania pozornej obecności/nieobecności ugrupowania azowego. Obserwowane różnice właściwości elektrochemicznych eterów azokoronowych z resztą N-acetylohistydyny lub resztami imidazolu uwidaczniają się przebiegiem chemicznej redukcji w silnie...
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Analysis of allophones based on audio signal recordings and parameterization
PublikacjaThe aim of this study is to develop an allophonic description of English plosive consonants based on recordings of 600 specially selected words. Allophonic variations addressed in the study may have two sources: positional and contextual. The former one depends on the syllabic or prosodic position in which a particular phoneme occurs. Contextual allophony is conditioned by the local phonetic environment. Co-articulation overlapping...
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Reliable data-driven modeling of high-frequency structures by means of nested kriging with enhanced design of experiments
PublikacjaData-driven (or approximation) surrogate models have been gaining popularity in many areas of engineering and science, including high-frequency electronics. They are attractive as a way of alleviating the difficulties pertinent to high computational cost of evaluating full-wave electromagnetic (EM) simulation models of microwave, antenna, and integrated photonic components and devices. Carrying out design tasks that involve massive...
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Influence of LCVD technologicalparameters on propertiesof polyazomethine thin films
PublikacjaPurpose: The aim of this paper is to show influence of technological parameters (temperature and gas streamintensity) of low-temperature chemical vapour deposition (LCVD) on optical properties and morphology ofpolyazomethine thin films.Design/methodology/approach: Thin layers of poly (1,4-phenylene-methylenenitrilo-1,4-phenylenenitrilo-methylene) (PPI) were prepared by low temperature LCVD method with use of argon as a transport...
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Coupled nonlinear Schrödinger equations in optic fibers theory
PublikacjaIn this paper a detailed derivation and numerical solutions of CoupledNonlinear Schr¨odinger Equations for pulses of polarized electromagnetic wavesin cylindrical fibers has been reviewed. Our recent work has been compared withsome previous ones and the advantage of our new approach over other methods hasbeen assessed. The novelty of our approach lies is an attempt to proceed withoutloss of information within the frame of basic...
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Wpływ parametrów docierania na jakość powierzchni powłok Cr2O3.
PublikacjaPrzedmiotem niniejszej rozprawy doktorskiej były badania wpływu wybranych parametrów docierania na jakość powłoki ceramiki Cr2O3. Analizowano wpływ wielkości ziarna, nacisków, prędkości i czasu docierania na wartości parametrów chropowatości powierzchni i ubytek liniowy powłoki ceramicznej nałożonej metodą plazmową na podłoże stalowe. Badania realizowano wg planowanego eksperymentu na docierarce jednotarczowej ze standardowym (pierścieniowym)...
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Visualization of the surface of the Nafion membrane
Dane BadawczeFuel cells use the chemical energy of hydrogen or other fuels to produce electricity. If the fuel is hydrogen, the only products are electricity, water and heat. Fuel cells are unique in the variety of their potential applications, they can use a wide variety of fuels. They are also highly scalable devices that can power both cars and mobile phones....
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Water-Lubricated Sintered Bronze Journal Bearings—Theoretical and Experimental Research
PublikacjaWater lubricated bearings are used from many years in shipbuilding, hydro power and other industries because of their advantages such as: extensive serviceable life, low coefficient of friction, longevity of shaft sleeve, good abrasion resistance, low maintenance required, unit simplicity, no danger of pollution and low price. Various types of water lubricated sliding bearings have been tested at the Technical University of Gdansk...
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Preparation of MnCo2O4 and Mn1.7CuFe0.3O4 single-layer, and novel MnCo2O4/ Mn1.7CuFe0.3O4 dual-layer spinel protective coatings on complex-shaped metallic interconnects by EPD method
PublikacjaCeramic protective coatings applied to metallic interconnects play a vital role in solid oxide cells (SOCs) preventing interconnect degradation. In this study, uniform, dense, and crack-free single-layer coatings of MnCo2O4, Mn1.7CuFe0.3O4, and dual-layer coatings of MnCo2O4/ Mn1.7CuFe0.3O4 spinel are deposited onto complex-shaped metallic interconnect using electrophoretic deposition (EPD) method. The porosity of sintered MnCo2O4...
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Reduction in Errors in Roughness Evaluation with an Accurate Definition of the S-L Surface
PublikacjaCharacterization of surface topography, roughly divided into measurement and data analysis, can be valuable in the process of validation of the tribological performance of machined parts. Surface topography, especially the roughness, can respond straightly to the machining process and, in some cases, is defined as a fingerprint of the manufacturing. When considering the high precision of surface topography studies, the definition...
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Determination of Selected Organic Acids in Animal Farm Water Samples by Ion Chromatography
PublikacjaLow molecular mass carboxylic acids (LCAs) occur in many environmental compartments due to natural processes and human activity. They are an important group of organic pollutants of waste water that mainly includes, volatile fatty acids, and also dicarboxylic, aromatic, hydroxy- and ketoacids. LCAs are present in the environment at concentrations between 1 to 5000 ppm and different methods have been reported for their determination...
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Man in Early Islamic Philosophy: Al-Kindi and Al-Farabi
PublikacjaMan was, neither for Al-Kindi, nor for Al-Farabi, a clearly isolated object of philosophical reflection. This does not mean, however, that both Islamic philosophers were not at all concerned with the uniqueness of man, his nature or the purpose of his existence. In order to understand and analyze in depth the philosophies of man voiced by Al-Kindi and Al-Farabi, one must focus primarily on their epistemologies, on their philosophical...
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Increasing the conductivity of V2O5 -TeO2 glass by crystallization: structure and charge transfer studies
PublikacjaIn the present paper, V2O5-TeO2 glass...
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Early prediction of macrocrack location in concrete and other granular composite materials
PublikacjaHeterogeniczne kruche kompozyty, takie jak beton, ceramika i skały składają się z ziaren połączonych wiązaniami. Pytanie, czy ścieżka pęknięcia, która prowadzi do zniszczenia może być przewidziania na podstawie znanych cech mikrostrukturalnych, a mianowicie łączności wiązań, rozmiaru, energii pękania, wytrzymałości pozostają otwarte. Istnieje wiele kryteriów pęknięć. Najczęściej używane są oparte na postulowanym ekstremum naprężenia...
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Structural and electrical properties of titanium-doped yttrium niobate
PublikacjaIn this work, the influence of the substitution of niobium by titanium in Y3Nb1-xTixO7-δ on the structural and electrical properties is reported. Several experimental techniques, i.e. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS) and Electrochemical Impedance Spectroscopy (EIS), were applied to investigate the system Y3Nb1-xTixO7-δ. Titanium in Y3Nb1-xTixO7-δ is an acceptor-type...
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Carboxylation Enhances Fragmentation of Furan upon Resonant Electron Attachment
PublikacjaWe report a dissociative electron attachment study to 2-furoic acid (C5H4O3) isolated in a gas phase, which is a model molecule consisting of a carboxylic group and a furan ring. Dissociation of furan by low energy electrons is accessible only via electronic excited Feshbach resonances at energies of incident electrons above 5 eV. On the other hand, carboxylic acids are well- known to dissociate via attachment of electrons at subexcitation energies....
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Surprising Radiolytic Stability of 8‑Thiomethyladenine in an Aqueous Solution
Publikacja8-Thiomethyladenine (ASCH3), a potentially radiosensitizing modified nucleobase, has been synthesized in a reaction between 8-thioadenine and methyl iodide. Despite favorable dissociative electron attachment (DEA) characteristics, the radiolysis of an aqueous solution of ASCH3 with a dose of X-ray amounting to as much as 300 Gy leads to no effects. Nevertheless, crossed electron-molecule beam experiments in the gas phase on ASCH3...
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Revealing dynamic changes of the volatile profile of food samples using PTR–MS
PublikacjaVolatile compounds carry valuable information regarding the properties of foodstuffs. Volatiles emitted from food can be used as, for example, indicators of quality, shelf-life, or authenticity. A better understanding of the multitude of transformations which occur during food processing could facilitate the optimisation of production, increase the desirability of food products, and also their wholesomeness. However, as some of...
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Emission Profiles of Volatiles during 3D Printing with ABS, ASA, Nylon, and PETG Polymer Filaments
PublikacjaIn this short communication we characterize the emission of volatile organic compounds (VOCs) from fused filament fabrication (FFF) 3D printing using four polymer materials, namely polyethylene terephthalate glycol-modified (PETG), acrylonitrile styrene acrylate (ASA), Nylon, and acrylonitrile butadiene styrene (ABS). Detailed emission profiles are obtained during thermal degradation of the polymers as a function of temperature...