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Wyniki wyszukiwania dla: CHITOSAN HYDROGEL
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Fabrication of Paper Sheets Coatings Based on Chitosan/Bacterial Nanocellulose/ZnO With Enhanced Antibacterial and Mechanical Properties
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Molecular dynamics simulations of the affinity of chitin and chitosan for collagen: the effect of pH and the presence of sodium and calcium cations
PublikacjaChitosan and chitin are promising biopolymers used in many areas including biomedical applications, such as tissue engineering and viscosupplementation. Chitosan shares similar properties with hyaluronan, a natural component of synovial fluid, making it a good candidate for joint disease treatment. The structural and energetic consequences of intermolecular interactions are crucial for understanding the biolubrication phenomenon...
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Biopolymers in designing modern antimicrobial medical materials. Part I. Biopolymer medical materials - collagen, chitosan
PublikacjaThe article is a review of the literature concerning the possible use of biopolymers for the preparation of dressings with antimicrobial activity. Authors show the potential of biopolymers: collagen and chitosan - which have the ability to immobilize and control the release of various active compounds - for providing the appropriate antibacterial, bacteriostatic and wound healing properties. Types of threats, for which the dressing...
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Towards azeotropic MeOH-MTBE separation using pervaporation chitosan-based deep eutectic solvent membranes
PublikacjaDeep eutectic solvents (DESs) are a new class of solvents that can offset some of the major drawbacks of common solvents and ionic liquids. When dealing with the preparation of dense membranes, the use of DESs is still challenging due to their low compatibility with the polymer phase. In this research, a novel L-proline:sulfolane (molar ratio 1:2) DES was synthesized and used for the preparation of more sustainable bio-based membranes...
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Antibacterial properties of laser-encapsulated titanium oxide nanotubes decorated with nanosilver and covered with chitosan/Eudragit polymers
PublikacjaTo provide antibacterial properties, the titanium samples were subjected to electrochemical oxidation in the fluoride-containing diethylene glycol-based electrolyte to create a titanium oxide nanotubular surface. Afterward, the surface was covered by sputtering with silver 5 nm film, and the tops of the nanotubes were capped using laser treatment, resulting in an appearance of silver nanoparticles (AgNPs) of around 30 nm in diameter...
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Hybrid cross-linked chitosan/protonated-proline:glucose DES membranes with superior pervaporation performance for ethanol dehydration
PublikacjaThis work explores a protonated L-proline:glucose (molar ratio 5:1) deep eutectic solvent (DES) in fabricating biopolymer membranes utilizing chitosan (CS). Initially, the miscibility of CS and DES to prepare homogeneous dense blend membranes has been investigated. Different techniques, such as scanning electron microscopy, contact angle (CA), atomic force microscopy (AFM), Fourier transformed infrared spectroscopy (FTIR) and swelling...
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Mechanical, Structural and Diffusion Studies of Hydrogel Polyurethane Nanocomposites Containing Modified Montmorillonite
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Mechanical, structural and diffusion studies of hydrogel polyurethane nanocomposites containing modified montmorillonite
PublikacjaW pracy zaprezentowano wyniki badań hydrożeli poliuretanowych zawierających poli(tlenek etylenu) oraz montmorylonit. Otrzymane układy scharakteryzowano z użyciem technik XRD, DMA, badań mechanicznych oraz wyznaczono chłonność wody i parametry dyfuzji.
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Hydrogen production from biomass using dark fermentation
PublikacjaHydrogen applicability in the power, chemical and petrochemical industries is constantly growing. Efficientmethods of hydrogen generation from renewable sources, including waste products, are currently being de-veloped, even though hydrogen is mainly produced through steam reforming or thermal cracking of natural gasor petroleum fractions. In paper alternative methods of hydrogen production with a particular emphasis on darkfermentation...
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Hydrogen degradation of high strength low alloyed steels.
PublikacjaBadano wpływ polaryzacji katodowej na własności stali węglowej, stali o podwyższonej i wysokiej wytrzymałości metodą stałego powolnego odkształcania.Stwierdzono, że stopień kruchości wodorowej każdej z badanych stali zależał od stężenia wodoru dyfuzyjnego.
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Hydrogen Production via Biomethane Reforming in DBD Reactor
PublikacjaProduction of hydrogen from CH4:CO2 (70%:30%) mixture simulating dry biogas in a DBD reactor supplied with AC of 1.0-2.0 kHz or nanosecond negative pulses is presented. We have found that hydrogen production and methane conversion degree increase linearly with discharge power in the range of up to 50 W. Nanosecond voltage pulses are much more efficient in hydrogen production than sine AC voltage
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The role of hydrogen in microwave plasma valorization of producer gas
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Hydrogen activated axial inter-conversion in SiC nanowires
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Hydrogen degradation of structural steels in technical hydrocarbon liquids
PublikacjaDla stali stopowych przeprowadzono badania absorpcji wodoru, mechaniczno-korozyjne przy stałej małej prędkości odkształcania, przy stałym obciążeniu i przy obciążeniu cyklicznie-zmiennym. Środowiskiem było paliwo kotłowe, przepracowany olej mineralny oraz gliceryna. Stwierdzono, iż pochłonięty wodór nie powoduje przedwczesnego zniszczenia stali poddanych działaniu stałego obciążenia ponizej granicy plastyczności oraz, że zaabsorbowany...
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Hydrogen Storage in Geological Formations—The Potential of Salt Caverns
PublikacjaHydrogen-based technologies are among the most promising solutions to fulfill the ze- ro-emission scenario and ensure the energy independence of many countries. Hydrogen is considered a green energy carrier, which can be utilized in the energy, transport, and chemical sectors. However, efficient and safe large-scale hydrogen storage is still challenging. The most frequently used hydrogen storage solutions in industry, i.e., compression...
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Transport of paracetamol in swellable and relaxing polyurethane nanocomposite hydrogels
PublikacjaPolyurethane hydrogels are potentially attractive materials for biomedical applications. They are able to absorb large amount of water, biological fluids or active substances, and thus, they have potential to be used as absorbents or wound-healing dressings. They are also used for the controlled release of therapeutics because of their capacity to embed biologically active agents in their water-swollen network. The presence of...
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Hydrogen degradation of high-strength weldable steels in seawater
PublikacjaOceniono podatność na niszczenie wodorowe stali spawalnych o wysokiej wytrzymałości przy obciążeniach monotonicznie rosnących. Badano dwa gatunki stali ulepszonych cieplnie i ich złącza spawane. Przeprowadzono próby rozciągania z małą prędkością odkształcania w wodzie morskiej przy polaryzacji katodowej. Wykonano próby przenikania wodoru metodą Devanathana-Stachurskiego.
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Hydrogen delayed cracking of high-strength weldable steels
PublikacjaOceniano podatność na niszczenie wodorowe stali 14HNMBCu o wysokiej wytrzymałości i jej połączeń spawanych przy obciążeniu stałym w wodzie morskiej. Badania przeprowadzono w powietrzu, oraz w środowisku wody morskiej przy potencjale korozyjnym i przy polaryzacji katodowej. Obecność lub brak opóźnionych pęknięć próbek z karbem przyjęto za miarę odporności na niszczenie wodorowe przy stałym obciążeniu.
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Correlation between partial inhibition of hydrogen evolution using thiourea and catalytic activity of AB5-type hydrogen storage alloy towards borohydride electrooxidation
PublikacjaDirect borohydride fuel cells (DBFCs) are devices which directly convert the chemical energy stored in the borohydride ion and oxidant into electrical energy as a result of redox reactions. Unfortunately, a significant amount of fuel is lost as a result of the undesirable hydrolysis reaction. The selection of an efficient borohydride hydrolysis inhibitor requires detailed knowledge regarding the interaction mechanism between the...
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Silk Fibroin/Collagen/Chitosan Scaffolds Cross-Linked by a Glyoxal Solution as Biomaterials toward Bone Tissue Regeneration
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Physico-Chemical Characterization and Biological Tests of Collagen/Silk Fibroin/Chitosan Scaffolds Cross-Linked by Dialdehyde Starch
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The effect of chitosan/TiO2/hyaluronic acid subphase on the behaviour of 1,2-dioleoyl-sn-glycero-3-phosphocholine membrane
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SURFACE CHARACTERISTICS OF DPPC MONOLAYERS DEPOSITED FROM TITANIUM DIOXIDE–CHITOSAN–HYALURONIC ACID SUBPHASES ON A GLASS SUPPORT
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THE EFFECTS OF APPLYING CHITOSAN OF DIFFERENT MOLECULAR WEIGHTS ON THE QUALITY OF KAMCHATKA BERRIES (LONICERA CAERULEA L.): PART 2
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Effects of Surface Pretreatment of Titanium Substrates on Properties of Electrophoretically Deposited Biopolymer Chitosan/Eudragit E 100 Coatings
PublikacjaThe preparation of the metal surface before coating application is fundamental in determining the properties of the coatings, particularly the roughness, adhesion, and corrosion resistance. In this work, chitosan/Eudragit E 100 (chit/EE100) were fabricated by electrophoretic deposition (EPD) and both their microstructure and properties were investigated. The present research is aimed at characterizing the effects of the surface...
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Electrophoretically Deposited Chitosan/Eudragit E 100/AgNPs Composite Coatings on Titanium Substrate as a Silver Release System
PublikacjaDue to the possibility of bacterial infections occurring around peri-implant tissues, it is necessary to provide implant coatings that release antibacterial substances. The scientific goal of this paper was to produce by electrophoretic deposition (EPD) a smart, chitosan/Eudragit E 100/silver nanoparticles (chit/EE100/AgNPs) composite coating on the surface of titanium grade 2 using different deposition parameters, such as the...
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The Production Possibility of the Antimicrobial Filaments by Co-Extrusion of the PLA Pellet with Chitosan Powder for FDM 3D Printing Technology
PublikacjaThe last decades have witnessed a major advancement and development in three-dimensional (3D) printing technology. In the future, the trend’s utilization of 3D printing is expected to play an important role in the biomedical field. This work presents co-extrusion of the polylactic acid (PLA), its derivatives (sPLA), and chitosan with the aim of achieving filaments for printing 3D objects, such as biomedical tools or implants. The...
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Formulation and evaluation of hydrogel containing dry extract of Tormentillae rhizoma designed for periodontal disease
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In vivo anti-inflammatory and anti-allergic activities of cynaroside evaluated by using hydrogel formulations
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Observation of the Hydrogen Migration in the Cation-Induced Fragmentation of the Pyridine Molecules
PublikacjaThe ability to selectively control chemical reactions related to biology, combustion, and catalysis has recently attracted much attention. In particular, the hydrogen atom relocation may be used to manipulate bond-breaking and new bond-forming processes and may hold promise for far-reaching applications. Thus, the hydrogen atom migration preceding fragmentation of the gas-phase pyridine molecules by the H+, H2+, He+, He2+, and...
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Elimination and migration of hydrogen in the vacuum-ultraviolet photodissociation of pyridine molecules
PublikacjaElimination of the excited hydrogen atoms H(n), n = 4–7, and hydrogen migration in formation of the excited NH(A 3Π) free radicals in the photodissociation of pyridine, C5H5N, molecules have been studied over the 17.5–70 eV photon energy range. In the measurements the photon-induced fluorescence spectroscopy technique has been applied. Both fragments are produced through excitation of pyridine molecules into higher-lying superexcited...
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Electrochemical impedance studies of AB5-type hydrogen storage alloy
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Electron-impact dissociation of molecular hydrogen: benchmark cross sections
PublikacjaWe present a joint experimental and theoretical investigation of a fundamental process in atomic and molecular physics: electron impact excitation of molecular hydrogen’s (H2) most dominant transition (X1Σg+ → b3Σu+). Excitation of this state is by far the main channel that causes the dissociation of H2 into H + H atoms at low energies. The Convergent Close-Coupling (CCC) calculations predicted significant, more than factor of...
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Two-dimensional hydrogen-like atom in a weak magnetic field
PublikacjaWe consider a non-relativistic two-dimensional (2D) hydrogen-like atom in a weak, static, uniform magnetic field perpendicular to the atomic plane. Within the framework of the Rayleigh-Schr¨odinger perturbation theory, using the Sturmian expansion of the generalized radial Coulomb Green function, we derive explicit analytical expressions for corrections to an arbitrary planar hydrogenic bound-state energy level, up to the fourth...
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Production of hydrogen from biomass and its separation using membranetechnology
PublikacjaHydrogen is an important raw material for chemical industry and feasible renewable energy carrier that could replace fossil fuels. However, the specie seldom exists in a form of pure H2. Therefore, to obtain hydrogen in volumes suitable to be used as a raw material it is necesary to decompose hydrogen-rich compounds. The carbohydrate-rich biomass can be an important source of hydrogen by applying the process of dark fermentation....
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A study of a reduction of a micro- and nanometric bismuth oxide in hydrogen atmosphere
PublikacjaA reduction of bismuth oxide in hydrogen atmosphere was investigated. The reaction was performed with a material in various structural forms: powder: with micrometric grains, powder with nanometric grains and powder pressed into pellets. The process was performed in both isothermal and non-isothermal conditions. An activation energy of the reaction calculated with Friedman method was found to be about 85 kJ/mol for the reduction...
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Hydrogen production from wood waste by mean of dark fermentation
PublikacjaThe utilization of wood wastes in clean and green chemistry method like by mean of dark fermentation, is a highly desired solution of waste management. In the article model for the estimation hydrogen potential of wood waste is given. The model has been used to calculate the potential theoretical hydrogen mass that can be produced from wood wastes in Pomerania and Silesia: pine, spruce, fir, beech and oak. In the introduction,...
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Positron scattering on molecular hydrogen: Analysis of experimental and theoretical uncertainties
PublikacjaExperiments performed in recent years on positron scattering from molecular hydrogen indicated a rise of the total cross section in the limit of zero energy, but essentially disagree on the amplitude of this rise. Mitroy and collaborators [J.-Y. Zhang et al., Phys. Rev. Lett. 103, 223202 (2009)] predicted a scattering length somewhat different from values deduced experimentally. Using a Markov chain Monte Carlo modified effective...
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Different Modes of Hydrogen Peroxide Action During Seed Germination
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The quantum free energy barrier for hydrogen vacancy diffusion in Na3AlH6
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Is hydrogen capable of playing a central atom role in superhalogen anions?
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Hydrogen evolution on the reduced TiO2 under simulated solar lamp
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The overabundance of excited hydrogen atoms produced in the H2++ furan reaction
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Hydrogen and chalcogen bonds in crystals of chalcogenadiazolecarboxylic acids – competition or cooperation?
PublikacjaThis article presents crystal structures of chalcogenadiazolecarboxylic acids bearing both a hydrogen and a chalcogen bond donor. The selected molecules varied in the size of the aromatic unit, the chalcogen atom and/or the position of the carboxyl group in the core structure. The most common synthons in their lattice are "R" _"2" ^"2" (8) self-complementary acid dimers or four-membered [Ch···N]2 rings. Supramolecular synthons...
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Hydrogen degradation of high-strength weldable steels in sea-water
PublikacjaW artykule przedstawiono ocenę podatności stali o wysokiej wytrzymałości oraz ich złączy spawanych na kruchość wodorową. Wykonano próby powolnego rozciągania na stalach gatunku 17HMBVA i 14HNMBCu oraz ich złączach spawanych, w środowisku wody morskiej, przy polaryzacji katodowej. Wykonano badania elektrochemiczne przenikania wodoru przez membrany pobrane z rożnych obszarów złączy spawanych.
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The Effect of Welding Conditions on Diffusible Hydrogen Content in Deposited Metal
PublikacjaThe article presents the results of a literature survey and preliminary tests which set out effects of welding conditions on the amount of diffusible hydrogen in deposited metal. Experiments were conducted by using rutile coated electrodes which generate high contents of diffusible hydrogen in deposited metal. The amount of diffusible hydrogen was determined by a glycerin test.Eleven factors were considered: the electrode angle,...
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Advanced vanadium modified steels for high pressure hydrogen reactors
PublikacjaPrzedstawiono nową generację stali chromowo-molibdenowych zmodyfikowanych wanadem, przeznaczonych do budowy wodorowych reaktorów i porównano ze stalami konwencjonalnymi. Opisano mikrostrukturę, właściwości i zastosowanie stali. Podkreślono wpływ mikrostruktury nowych stali na przebieg degradacji środowiskowej.
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Hydrogen degradation of the 26H2MF alloy steel in H2SO4 and hydrocarbon environments.
PublikacjaSTAL 26H2MF ZOSTALA PODDANA RÓZNEJ OBRÓBCE CIEPLNEJ, PO KTÓREJ UZYSKAŁA ONA RÓŻNĄ MIKROSTRUKTURĘ ORAZ CHARAKTER PRZEŁOMU. WYKONANO PRÓBY POWOLNEGO ODKSZTAŁCANIA W ROZCIEŃCZONYM KWASIE SIARKOWYM, PALIWIE CIĘZKIM I PRZEPRACOWANYM OLEJU SILNIKOWYM PRZEPRACOWANYM.
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Critical conditions of hydrogen-air detonation in partially confined geometry
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Direct reduction of pellets through hydrogen: Experimental and model behaviour
PublikacjaThis paper presents the hydrogen reduction behaviour of industrial pellets designed for the efficient hydrogen based direct reduction. The pellets were provided with very low non ferrous oxides percentage (0.52 of basicity index) and with the absence on TiO2 oxides. The pellets measured diameters in the range 1.14–1.72 cm and were characterized in terms of porosity, pores size, tortuosity and compression strength. The pellets were...