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Wyniki wyszukiwania dla: fractions of strontium
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The influence of roughness and geometrical structure of tissue surface on friction forces during the tissue cultivation in bioreactor = Wpływ chropowatości i geometrycznej struktury powierzchni tkanki na siły tarcia podczas hodowli tkanek w bioreaktorze
PublikacjaNajnowsze trendy naukowe w Unii Europejskiej i w USA w zakresie biotribologii idą w kierunku uwzględnienia zmian chropowatości zewnętrznej powierzchni tkanki w trakcie procesu hodowli w bioreaktorze.W mikrokontenerach bioreaktora hodowana tkanka jest permanentnie zraszana i polewana mediami o odżywczych oraz terapeutycznych właściwościach nienewtonowskich, gdzie często są to ciecze z odpowiednimi dodatkami lepko-sprężystymi wywołującymi...
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From Structure to Luminescent Properties of B2O3-Bi2O3-SrF2 Glass and Glass-Ceramics Doped with Eu3+ Ions
PublikacjaGlass-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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Modeling organic nitrogen conversions in activated sludge bioreactors
PublikacjaFor biological nutrient removal (BNR) systems designed to maximize nitrogen removal, the effluent total nitrogen (TN) concentration may range from 2.0 to 4.0 g N/m3 with about 25-50% in the form of organic nitrogen (ON). In this study, current approaches to modeling organic N conversions (separate processes vs. constant contents of organic fractions) were compared. A new conceptual model of ON conversions was developed and combined...
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Mathematical modeling of hydrogen production performance in thermocatalytic reactor based on the intermetallic phase of Ni3Al
PublikacjaThe main goal of the following work is to adjust mathematical modelling for mass transfer, to specific conditions resulting from presence of chemical surface reactions in the flow of the mixture consisting of helium and methanol. The thermocatalytic devices used for decomposition of organic compounds incorporate microchannels coupled at the ends and heated to 500 oC at the walls regions. The results of the experiment were compared...
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Fabrication and structural properties of Y and Fe co-doped SrTiO3 nanoceramics for SOFC
PublikacjaYttria and iron co-doped strontium titanate perovskites, (Y0,07Sr0,93Ti1-xFexO3-δx=0,1; 0,2) samples were fabricated by two methods: solid-state synthesis (SS) and the Pechinisol-gel modified method. The morphology of samples were measured by SEM and X-raydiffraction. Results were compared and discussed. The strong relationship between fabricationprocedure and microstructure has been proven. It was also observed, that the nanoceramicsobtained...
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Solid Oxide Fuel Cells with Ni infiltrated perovskite anode
PublikacjaNiobium-doped strontium titanate was used as the anode for a solid oxide fuel cell. Electrolyte-supported cells were prepared with pure perovskite and composite perovskite–yttria–stabilized-zirconia (YSZ) anodes. Fuel cell tests demonstrated significant improvement in power density after infiltration with a small amount of Ni. The obtained values of power densities are comparable with conventional Ni/YSZ cermet anode. In addition,...
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Solvation of alkaline earth metal ions in N,N-dimethylformamide and N,N-dimethylacetamide – A volumetric and acoustic study
PublikacjaDensities and sound velocities at temperatures (298.15, 303.15, 308.15, 313.15 and 318.15) K of magnesium(II), calcium(II) and strontium(II) rifluoromethanesulfonates (triflates), as well as barium(II) perchloratein N,N-dimethylformamide (dmf) and N,N-dimethylacetamide (dma) have been measured over the composition range studied. From these results, apparent molar volumes and apparent molar isentropic compressibilities at infinite...
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Lanthanide ions (Eu3+, Er3+, Pr3+) as luminescence and charge carrier centers in Sr2TiO4
PublikacjaA series of strontium orthotitanate (Sr2TiO4) samples doped with 2% of a mole of europium, praseodymium, and erbium were obtained using the solid-state synthesis method. The X-ray diffraction (XRD) technique confirms the phase purity of all samples and the lack of the influence of dopants at a given concentration on the structure of materials. The optical properties indicate, in the case of Sr2TiO4:Eu3+, two independent emission...
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A study of the kinetics of bismuth telluride synthesis by an oxide reduction method
PublikacjaThe kinetics of a reduction of bismuth and tellurium oxides in a hydrogen atmosphere, leading to the formation of thermoelectric bismuth telluride is investigated. The evaluation of the reaction kinetics was based on a thermogravimetric analysis performed in non-isothermal conditions. A non-parametric analysis method and the Friedman method were used for the evaluation of the data. Additionally, for a better understanding of the...
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Structural Properties and Water Uptake of SrTi1−xFexO3−x/2−δ
PublikacjaIn this work, Fe-doped strontium titanate SrTi1−xFexO3−x/2−δ, for x = 0–1 (STFx), has been fabricated and studied. The structure and microstructure analysis showed that the Fe amount in SrTi1−xFexO3−x/2−δ has a great influence on the lattice parameter and microstructure, including the porosity and grain size. Oxygen nonstoichiometry studies performed by thermogravimetry at different atmospheres showed that the Fe-rich compositions...
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Powder metallurgy of the porous Ti-13Nb-13Zr alloy of different powder grain size
PublikacjaThe objective of the present project was to determine the effects of powder granulation (fraction of grain size) for the Ti-13Nb-13Zr alloy, produced by powder metallurgy, on its porosity, grain cohesion, compressive strength, and Young`s modulus. Two powder fractions, 45–105 µm, and 106–250 µm were applied. The 50 mass pct of NH4HCO3 was added as a space holder. The specimens were in compaction stage uniaxially pressed at pressure...
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Electronic transition dipole moment functions of the first singlet Delta gerade and first triplet Delta ungerade states of the Lithium dimer
Dane BadawczeElectronic transition dipole moment functions (ETDMF) of the first singlet Delta gerade (1sDg) and first triplet Delta ungerade (1tDu) states have been calculated for the Lithium dimer. ETDMFs are needed in understanding processes like photodissociation, photoassociation, cooling, and trapping of molecules. The results of the four ETDMFs have been obtained...
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Electronic transition dipole moment functions of the first singlet Pi gerade and first triplet Pi gerade states of the Lithium dimer
Dane BadawczeElectronic transition dipole moment functions (ETDMF) of the first singlet Pi gerade (1sPg) and first triplet Pi gerade (1tPg) states have been calculated for the Lithium dimer. ETDMFs are needed in understanding processes like photodissociation, photoassociation, cooling, and trapping of molecules. The results of the four ETDMFs have been obtained...
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Electronic transition dipole moment functions of the second singlet Pi gerade and second triplet Pi gerade states of the Lithium dimer
Dane BadawczeElectronic transition dipole moment functions (ETDMF) of the second singlet Pi gerade (2sPg) and second triplet Pi gerade (2tPg) states have been calculated for the Lithium dimer. ETDMFs are needed in understanding processes like photodissociation, photoassociation, cooling, and trapping of molecules. The results of the four ETDMFs have been obtained...
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Electrical and structural properties of Nb-doped SrTiO3
PublikacjaNiobium-doped strontium titanate synthesized via conventional solid-state reaction has been studied. Influence of niobium content on the lattice parameters and electrical conductivity has been reported. Various reduction conditions have been investigated. For samples reduced in hydrogen at 1400°C, a transition from thermally activated to metallic behavior has been observed. Maximum electrical conductivity (ca. 55 Scm−1 at 650°C)...
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HYDROGEN PRODUCTION PERFORMANCE IN THERMOCATALYTIC REACTOR BASED ON THE INTERMETALLIC PHASE OF NI3AL
PublikacjaThe main aim of the following paper is mathematical modelling for momentum, heat and mass transfer, which is accompanied by chemical surface reactions of the flow of the mixture helium and methanol. The thermocatalytic devices used for decomposition of hydrocarbons incorporate vertical microchannels coupling at the ends and heated to 500 oC at the walls. The results of the experiment were compared with CFD calculations to calibrate...
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Single chamber solid oxide fuel cell - investigation of cathodes
PublikacjaSporo uwagi w ostatnim okresie przykuwają jednokomorowe ogniwa w związku z potencjalnym uroszczeniem konstrukcji w porównaniu z konwencjonalnymi ogniwami. W pracy zbadano wpływ warunków syntezy różnych materiałów katodowych na wydajność ogniw. Ogniwa zbudowane zostały z typowych materiałow stosowanych na ogniwa: stabilizowanego tleneku cyrkonu jako elektrolit, cermetu niklowego jako anody oraz samaru kobaltanu domieszkowanego strontem,...
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Sensitive Demonstration of the Twin-Core Couplers including Kerr Law Non-Linearity via Beta Derivative Evolution
PublikacjaTo obtain new solitary wave solutions for non-linear directional couplers using optical meta-materials, a new extended direct algebraic technique (EDAT) is used. This model investigates solitary wave propagation inside a fiber. As a result, twin couplers are the subject of this study. Kerr law is the sort of non-linearity addressed there. Because it offers solutions to problems with large tails or infinite fluctuations, the resulting...
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Apparent molar volumes and compressibilities of alkaline earth metal ions in methanol and dimethylsulfoxide
PublikacjaTemperature dependencies of density of magnesium (II), calcium (II), strontium (II), barium (II) perchlorates as well as beryllium (II), and sodium trifluoromethanesulfonates in methanol and dimethylsulfoxide have been determined over the composition range studied. From density data the apparent molar volumes and partial molar volumes of the salts at infinite dilution as well as the expansibilities have been evaluated. The apparent...
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Chemistry and Nanochemistry 2023
Kursy OnlineWe start from General Chemistry, including: calculus in chemistry, bonds, balancing the chemical reactions, redox reactions, electrochemistry, pH, acids, bases, salts, oxides, organic molecules, and many informations about synthesis, analysis and applications in nanochemistry.
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Dariusz Witt prof. dr hab. inż.
Osoby -
Materials science. Quantum particle approach. 2023.
Kursy OnlineQuantum ideas applied for particle systems and for chemical reactions.
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Właściwości strukturalne i katalityczne domieszkowanych związków typu SrTi(1-x)Fe(x)O3
PublikacjaPublikacja naukowa opisująca wytwarzanie i badanie właściwości strukturalnych i katalitycznych domieszkowanego itrem i żelazem tytanianu strontu.
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Donor-substituted SrTi1+xO3−δ anodes for SOFC
PublikacjaPrzebadano wpływ niestechiometrii na właściwości tytanianu strontu domieszkowanego niobem. Zaproponowano chemię defektów dla tego typu związków.
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Solid oxide fuel cells with Ni-infiltrated perovskite anode
PublikacjaWytworzono próbki na bazie tytanianu strontu domieszkowanego niobem i przebadano wpływ nasączania niklem na właściwości tych materiałów.
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The quality of sewage sludge stabilized for a long time in reed basins
PublikacjaThe aim of the work was to determine changes of long-term sewage sludge quality stabilized in reed basins from 7-15 years. The following parameters were evaluated: dry matter and organic matter concentration, nitrogen, phosphorus, and selected heavy metal (Cd, Ni, Pb, Cr, Cu, Zn) fractions. The material for the investigations was collected from 4 reed basin systems (utilisated sewage sludge) located in conventional WWTPs in Denmark...
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Quantification of ultrafine airborne particulate matter generated by the wear of car brake materials
PublikacjaThe wear of car brakes is one of the main sources of airborne particulate matter in urban environments. Ultrafine wear particles are of special environmental interest since they can easily penetrate the human body through inhalation and cause various diseases. In the present study, the contribution of ultrafine particles to airborne particulate matter emitted from car brake materials was investigated under different friction conditions....
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Electronic transition dipole moment functions of the second singlet Sigma ungerade plus and second triplet Sigma gerade plus states of the Lithium dimer
Dane BadawczeElectronic transition dipole moment functions (ETDMF) of the second singlet Sigma ungerade plus (2sSu+) and second triplet Sigma gerade plus (2tSg+) states have been calculated for the Lithium dimer. ETDMFs are needed in understanding processes like photodissociation, photoassociation, cooling, and trapping of molecules. The results of the four ETDMFs...
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Electronic transition dipole moment functions of the first singlet Sigma ungerade plus and first triplet Sigma gerade plus states of the Lithium dimer
Dane BadawczeElectronic transition dipole moment functions (ETDMF) of the first singlet Sigma ungerade plus (1sSu+) and first triplet Sigma gerade plus (1tSg+) states have been calculated for the Lithium dimer. ETDMFs are needed in understanding processes like photodissociation, photoassociation, cooling, and trapping of molecules. The results of the four ETDMFs...
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Electronic transition dipole moment functions of the third singlet Sigma ungerade plus and third triplet Sigma gerade plus states of the Lithium dimer
Dane BadawczeElectronic transition dipole moment functions (ETDMF) of the third singlet Sigma ungerade plus (3sSu+) and third triplet Sigma gerade plus (3tSg+) states have been calculated for the Lithium dimer. ETDMFs are needed in understanding processes like photodissociation, photoassociation, cooling, and trapping of molecules. The results of the four ETDMFs...
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On the relationship between the structural and volumetric properties of solvated metal ions in O-donor solvents using new structural data in amide solvents
PublikacjaThe structures of the N,N-dimethylformamide (dmf), N,N-dimethylacetamide (dma), and N,N-dimethylpropionamide (dmp) solvated strontium and barium ions have been determined in solution using large angle X-ray scattering and EXAFS spectroscopy. The strontium ion has a mean coordination number (CN) between 6.2 and 6.8, and the barium ion has a mean CN between 7.1 and 7.8 in these amide solvents. The non-integer numbers indicates that...
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Direct design of Controlled Modulus Columns (CMC) based on in-situ testing
PublikacjaIn this paper, the serviceability limit state and bearing capacity of tension screw displacement piles were analyzed using the results of static pile load tests, carried out on the test plot near the Elbląg city, and field, and laboratory tests. The paper presents the methodology of determining the pile load-settlement curve using different types of t-z transfer functions. The new method of constructing the pile load-settlement...
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An inclination in Thermal Energy Using Nanoparticles with Casson Liquid Past an Expanding Porous Surface
PublikacjaPhysical aspects of inclined MHD nanofluid towards a stretching sheet embedded in a porous medium are visualized. Two types of nanoparticles are used named as copper and alumna dioxide with water as base fluid. Similarity transformations are used to convert the partial differential equations into the set of ordinary differential equation. Closed solutions are found to examine the velocity and the temperature profiles. It is examined...
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Paintings
PublikacjaThe painting as a curtain (...) A contradiction is therefore what constitutes a painting, and ambiguity is its right. As a young artist, I intuitively defined the work of art as a boundary. Over the years that intuition changed into a conviction that the particular form of art which is painting at the same time reveals and hides; it exists at this intersection of functions as a see-through curtain. We don’t know why there are some...
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Badanie ogniwa paliwowego typu SORC z anodą na bazie perowskitu SrTi03
PublikacjaPublikacja naukowa opisująca budowę i badanie ogniwa paliwowego typu SOFC zbudowanego na elektrolicie z zastosowaniem anody na bazie domieszkowanego donorowo tytanianu strontu.
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Hyperbolic heat conduction at a microscopic sliding contact with account of adhesion-deformational heat generation and wear
PublikacjaDifferent non-Fourier models were proposed to simulate temperatures in materials subjected to extremely fast thermal disturbances, when the speed of heat propagation should be concerned. The present study investigated temperature and heat balance at a microscopic sliding contact during a single frictional interaction based on the Cattaneo-Vernotte hyperbolic heat conduction equation. Two fundamental features of friction, namely,...
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Modeling and simulation of blood flow under the influence of radioactive materials having slip with MHD and nonlinear mixed convection
PublikacjaRadioactive materials are widely in industry, nuclear plants and medical treatments. Scientists and workers in these fields are mostly exposed to such materials, and adverse effects on blood and temperature profiles are observed. In this regard, objective of the current study is to model and simulate blood based nanofluid with three very important radioactive materials, named as Uranium dioxide (UO2), Thorium dioxide (ThO2) and...
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Assessment of metal removal in a surface flow constructed wetland treating landfill leachate
PublikacjaThe study concerns heavy metal retention and transformation processes in a free water surface constructed wetland treating landfill leachate in a temperate climate. The total effectiveness of heavy metals removal in the analyzed CW was evaluated basing on heavy metals inflow and outflow concentrations. The concentrations of eight heavy metals (Fe, Mn, Zn, Pb, Ni, Cu, Cr, Cd) in landfill leachate (LL) and sediments were measured....
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Ocena odporności powłok na bazie DLC na doraźne uszkodzenie w warunkach tarcia ślizgowego ze smarowaniem wodą i solą fizjologiczną = Evaluation of DLC based coatings resistance to instanteneous damage under sliding friction conditions with distilated water or saline lubrication
PublikacjaWykonano serię testów w celu wyznaczenia granicznych warunków wymuszenia, zdefiniowaego jako średnie naciski powierzchniowe oraz prędkość ślizgania, po przekroczeniu których następuje gwałtowne zniszczenie powłoki. Na podstawie wyników pomiarów opracowano aproksymowane charakterystyki granicznych wymuszeń w układzie p - v oraz pokrewnych dla badanych materiałów, smarów i zakresu parametrów wymuszenia.
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Generalization of Kramers-Krönig relations for evaluation of causality in power-law media
PublikacjaClassical Kramers-Krönig (K–K) relations connect real and imaginary parts of the frequency-domain response of a system. The K–K relations also hold between the logarithm of modulus and the argument of the response, e.g. between the attenuation and the phase shift of a solution to a wave-propagation problem. For square-integrable functions of frequency, the satisfaction of classical K–K relations implies causality in the time domain....
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Application of gas chromatography to evaluate the quality of rapeseed oil
PublikacjaTwo-dimensional gas chromatography is an analytical technique, which is increasingly being used in food research. Through the analysis of volatile fraction, it is possible to determine the quality of food products. One of the reasons for the deterioration of food is thermal degradation. Products that are often subject to degradation reactions due to temperatures are edible oils. In the thesis, the results of edible oils with different...
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Clickable polysaccharides for biomedical applications: A comprehensive review
PublikacjaRecent advances in materials science and engineering highlight the importance of designing sophisticated biomaterials with well-defined architectures and tunable properties for emerging biomedical applications. Click chemistry, a powerful method allowing specific and controllable bioorthogonal reactions, has revolutionized our ability to make complex molecular structures with a high level of specificity, selectivity, and yield...
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Synthesis and properties of porous Sr 0.96 Y 0.04 Ti 1−x Nb x O 3
PublikacjaA series of porous, single phase Sr0.96Y0.04Ti1-xNbxO3 samples was obtained using a wet synthesis method (modified citrate sol-gel) method. Temperature-programmed reduction (TPR) and temperature-programmed oxidation (TPO) measurements have shown high stability of the obtained material in variable (oxidizing/reducing) atmospheres. All samples exhibit high conductivity in hydrogen atmosphere with the highest value (around 1S/cm)...
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Interaction of SrTi0.65Fe0.35O3-δ with LaNi0.6Fe0.4O3-δ, La0.6Sr0.4Co0.2Fe0.8O3-δ and Ce0.8Gd0.2O2-δ
PublikacjaIron doped strontium titanates SrTi1-xFexO3-δ are perovskites of versatile properties. They can be used in solid oxide fuel cells or high temperature oxygen sensors. Their reactivity with electrolyte materials, cathode buffer layer materials, other cathode materials or current collector layers has not been fully tested. In this study we use X-ray diffraction to check SrTi0.65Fe0.35O3-δ compatibility with Ce0.8Gd0.2O2-δ (used as...
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Thanos Of Titan
Osoby -
Variable Order Differential Models of Bone Remodelling * *This work was supported by FCT, through IDMEC, under LAETA, projects UID/EMS/50022/2013, BoneSys, joint Polish-Portuguese project Modelling and controlling cancer evolution using fractional calculus, PERSEIDS (PTDC/EMS-SIS/0642/2014) and IF/00653/2012
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Electrical and structural properties of Nb-doped SrTiO3 ceramics
PublikacjaPrzebadano wpływ zawartości niobu na strukturę i własności elektryczne tytanianu strontu. Zbadany został wpływ warunków redukcji i porowatości na właściwości materiału. Za optymalne uznano domieszkowanie niobem w wysokości 2% molowych.
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Evaluation of structural change during fast transformation process of cross-linked NR into liquid NR by light pyrolysis
PublikacjaThe presence of cross-linked networks in rubber creates a tremendous problem for recycling and reusing of waste rubber. Fast transformation of cross-linked natural rubber (NR) into liquid natural rubber was carried out by light pyrolysis in temperature range from 240 to 300 °C in variable time (in range: 1–30 min). The transformation efficiency was evaluated by measuring the sol fraction and the cross-link density of the gel fraction....
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A New Approach of Solidification Analysis in Modular Latent Thermal Energy Storage Unit Based on Image Processing
PublikacjaThe solidification process of RT18HC in a cylindrical shell and tube storage unit has been studied using a new methodology based on image processing. The main idea of the algorithm is to label the region of solidification and use statistical functions to calculate the dimensions of the solidification front over time. Said analysis includes two methods. The first method is to measure the solid fraction changes during solidification....
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Sensitivity analysis of free torsional vibration frequencies of thin-walled laminated beams under axial load
PublikacjaThe paper addresses sensitivity analysis of free torsional vibration frequencies of thin-walled beams of bisymmetric open cross-section made of unidirectional fibre-reinforced laminate. The warping effect and the axial end load are taken into account. The consideration is based upon the classical theory of thin-walled beams of non-deformable cross-section. The first-order sensitivity variation of the frequencies is derived with...