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Wyniki wyszukiwania dla: electron paramagnetic resonance
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The structure, including stereochemistry, of levorin A1
PublikacjaThe constitution and stereostructure of levorin A1 1, an aromatic heptaeneantifungal antibiotic, was established on the basis of NMR studies, which contained DQFCOSY,ROESY, HSQC and HMBC experiments. Mycosamine moiety was used as an internalchiral probe to determine the absolute configuration of levorin A1 stereogenic centers: 13S,15R, 17S, 18R, 19S, 21R. The relative configuration of the remaining stereogenic centers wasassigned...
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Study of the Effect of Filling Thermoplastic Medical Polyurethane with PVA, PLA or Diatomite on the Relaxation Times Distributions of 1H NMR
PublikacjaIn this work, to characterize the mobility of diferent sections of the macromole‑ cules of polyurethane (PUR), polyvinyl alcohol (PVA), and polylactic acid (PLA), as well as the density of crosslinks of the polymer chains when using fllers, we used the distributions of spin–lattice and spin–spin relaxation times for the protons. It is shown that the rigidity of the thermoplastic polymers depends on the sizes of the granules of...
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Monosaccharides as internal probes for the determination of the absolute configuration of 2-butanol
PublikacjaD-dlukoza, D-mannoza i L-ramnoza zostały poddane reakcji z mieszaniną racemiczną 2-butanolu. Otrzymane w ten sposób glikozydy były analizowane za pomocą spektroskopii NMR, z wykorzystaniem eksperymentów COSY i NOESY. Analiza konformacyjna wiązania glikozydowego (dokonana w oparciu o modelowanie molekularne i heteronuklearne stałe sprzężenia) wraz z analizą sprzężeń dipolowych obserwowanych w widmie NOESY umożliwiła określenie konfiguracji...
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Stereostructure of mycoheptin A2
PublikacjaThe absolute configurations of all the stereogenic centers of the antibiotic mycoheptin A2 were established upon previously elaborated general procedure, consisting of DQF-COSY, NOESY, ROESY, HSQC and HMBC experiments as major tools. The structure of mycoheptin A2 without stereochemistry of its aglycone has been reported before.
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Silver-modified titania with enhanced photocatalytic and antimicrobial properties under UV and visible light irradiation
PublikacjaCommercial titania photocatalysts were modified with 2 wt% of silver by photodeposition. The properties of the samples were characterized by DRS, XPS, XRD, FE-SEM and STEM. The modified samples exhibited activity under visible light and enhanced activity under UV irradiation for 2-propanol and acetic acid oxidation, respectively. The time-resolved microwave conductivity (TRMC) analysis indicated that enhanced activity (2.5–8-fold...
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SEM micrographs of V2O5 nanorods as cathode material in Li-ion batteries
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of V2O5 nanorods as cathode materials before and after the galvanostatic charge/discharge curves.
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SEM micrographs of V2O5 nanocrystals as cathode material in Li-ion batteries
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of V2O5 nanocrystals as cathode materials before and after the galvanostatic charge/discharge curves.
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Synthesis and characterization of mononuclear Zn(II), Co(II) and Ni(II) complexes containing a sterically demanding silanethiolate ligand derived from tris(2,6-diisopropylphenoxy)silanethiol
PublikacjaFour heteroleptic complexes of zinc(II), cobalt(II) and nickel(II) containing a monodentate silanethiolate ligand derived from tris(2,6-diisopropylphenoxy)silanethiol (TDST), were prepared and characterized. The geometries of ligands in the complexes are typical: distorted tetrahedral in zinc and cobalt(II) complexes and square planar in nickel(II) compound. Magnetic studies performed for Ni(II) and Co(II) compounds confirm the...
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Supramolecular junctions of the PDA tetramers
Dane BadawczeIn this dataset, a set of polydopamine (PDA) supramolecular junctions with linear and cyclic tetramers in different oxidation states (indolequinone , IQ or dihydroxyindole, DHI) in the scattering region are investigated. Electronic structure of the supramolecular junction with cyclic and linear PDA tetramers, including Electron density maps for the...
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Total Ionization Cross Sections of Selected Amino Acids
Dane BadawczeThe data set contains tabulated values of cross-sections for a single electron-impact ionization of selected amino acids (glycine, alanine, phenylalanine, proline and tryptophan) calculated using binary-encouter-Bethe method. The data have been published in graphical form (figure 1) in the following paperA.M. Sheer, P. Mozejko, G.A. Gallup, P.D. Burrow...
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SEM micrographs of VO2 and V6O13 nanostructures
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of VO2 and V6O13 thin films deposited on a silicon substrate. The as-prepared thin films were annealing under a reducing atmosphere (94% Ar, 6% H2) at 600 and 700C for 10h.
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SEM micrographs of NH4VO3 crystals - molar concetration factor after annealing
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of NH4VO3 nano_crystals obtained by the LPE-IonEx method with different morphology after annealing at 400C under argon atmosphere (with a heating rate of 10 C/min).
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SEM micrographs and photos of salivary gland stones
Dane BadawczeThis dataset contains SEM micrographs and high-resolution photographs taken for salivary gland stones (sialolith) extracted during joint studies between Medical University of Gdansk and Gdansk University of Technology.
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SEM micrographs of ammonium vanadate nanocrystals
Dane BadawczeThe DataSet contains the electron microscopy (SEM) micrographs of ammonium vanadate nanobelts obtained by the hydrothermal method with different conditions. The results show that the morphology of samples dependent on reaction conditions.
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SEM micrographs of morphology evolution of VO2 and V2O3 thin films obtained at 1000°C
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of VO2 and V2O3 thin films obtained by the sol-gel method. The information about sol synthesis is described in the Journal of Nanomaterials. The thin films were deposited on a silicon and quartz glass substrate and were annealing at 1000°C under an argon atmosphere.
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SEM micrographs of vanadium oxide nanostructures obtained by V2O5 recrystallization at 1000°C
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of vanadium oxide nanostructures on quartz glass and silicon substrates obtained by recrystallization of V2O5 thin films at 1000°C under synthetic air. The thin films were obtained by the sol-gel method. The information about sol synthesis is described in the Journal of Nanomaterials.
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SEM micrographs of vanadium oxide nanostructures obtained by V2O5 recrystallization at 800°C
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of vanadium oxide nanostructures on quartz glass and silicon substrates obtained by recrystallization of V2O5 thin films at 800°C under synthetic air. The thin films were obtained by the sol-gel method. The information about sol synthesis is described in the Journal of Nanomaterials.
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SEM micrographs of morphology evolution of VO2 and V2O3 nanostructures
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of VO2 and V2O3 nanostructures obtained by the sol-gel with different reaction conditions. The information about xerogel powder synthesis is described in the Journal of Nanomaterials. The xerogel powder was annealing under argon atmosphere in the temperature range 400-800C. The...
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SEM micrographs of vanadium oxide nanostructures obtained by V2O5 recrystallization at 1200°C
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of vanadium oxide nanostructures on quartz glass and silicon substrates obtained by recrystallization of V2O5 thin films at 1200°C under synthetic air. The thin films were obtained by the sol-gel method. The information about sol synthesis is described in the Journal of Nanomaterials.
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Chemistry of the phosphinophosphinidene tBu2P-P, a novel ă-electron ligand.Appl. Organomet. Chem. [online]**2003 vol. 17 [6 December 2002] s. 28-35, 10 rys. bibliogr. 53 poz. Dostępny w Internecie www.interscience.wiley.com Chemia fosfinofosfinidenu tBu2P-P, nowego liganda ă-elektronowego.
PublikacjaFosfanofosfiniden tBu2P-P w kompleksach z metalami przejściowymi jest z re-guły kompleksowany na sposób hapta-2 i przyjmuje geometrię 1,1-ditertbutyl-difosfenu. W reakcjach z cyklicznymi olefinami związek ten wykazuje właści-wości elektrofilowego singletowego karbenu.
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Hydrothermal reactions: From the synthesis of ligand to new lanthanide 3D-coordination polymers
PublikacjaThe organic ligand 2,5-piperazinedione-1,4-diaceticacid (H2PDA) was synthesized under hydrothermal conditions starting from the iminodiacetic acid and catalyzed by oxalic acid. The X-ray powder diffraction data indicates that the compound crystallizes in the P21/c space group as reported in the literature. The ligand was also characterized by elemental analysis, magnetic nuclear resonance, infrared spectroscopy and thermogravimetric...
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Elucidating photoluminescent properties of Eu‐doped Ca–Al–Si–O(–N) glasses and the local structures of Eu ions
PublikacjaEuropium (Eu) ion–doped luminescent materials have attracted considerable attention for their numerous optical applications. Eu-doped Ca–Al–Si–O(–N) glasses were synthesized from a mixture of oxynitride glasses and Eu2O3 powder using a standard melt-quenching technique in a radiofrequency furnace. The source Eu trivalent ions primarily changed to Eu2+ during melting, and the ratio of Eu2+ ions increased with an increase in Eu content...
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Scanning Electron Microscopy Facility
Laboratoria -
Kagome Lattice Promotes Chiral Spin Fluctuations
PublikacjaDynamical spin fluctuations in magnets can be endowed with a slight bent toward left- or right-handed chirality by Dzyaloshinskii-Moriya interactions. However, little is known about the crucial role of lattice geometry on these chiral spin fluctuations and on fluctuation-related transport anomalies driven by the quantum-mechanical (Berry) phase of conduction electrons. Via thermoelectric Nernst effect and electric Hall effect experiments,...
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SEM micrographs of NH4VO3 crystals - molar concetration factor
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of NH4VO3 nano_crystals obtained by the LPE-IonEx method. The SEM images clearly show that the morphology of the end product can be nicely tuned by changing the molar concentration of ammonium salt in the solvent.
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SEM micrographs of morphology evolution of VO2 and V2O3 thin films obtained at 700°C
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of VO2 and V2O3 thin films obtained by the sol-gel method. The information about sol synthesis is described in the Journal of Nanomaterials. The thin films with different thicknesses (3-9 AsP layers) were deposited on a silicon substrate and were annealing at 700°C under an argon...
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SEM micrographs of morphology evolution of VO2 and V2O3 thin films obtained at 1000°C dependent on film thickness
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of VO2 and V2O3 thin films obtained by the sol-gel method. The information about sol synthesis is described in the Journal of Nanomaterials. The thin films with different thicknesses (2-3 AsP layers) were deposited on a silicon substrate and were annealing at 1000°C under an argon...
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SEM micrographs of morphology evolution of VO2 and V2O3 thin films obtained at 500°C
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of VO2 and V2O3 thin films obtained by the sol-gel method. The information about sol synthesis is described in the Journal of Nanomaterials. The thin films with different thicknesses (3-9 AsP layers) were deposited on a silicon substrate and were annealing at 500°C under an argon...
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SEM micrographs of morphology evolution of V2O5 thin films on quartz glass
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of V2O5 thin films deposited on a quartz glass substrate. The as-prepared thin films were annealing under an oxidizing atmosphere in the temperature range 200-600C. The results show that the morphology of the films dependent on the annealing temperature.
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SEM micrographs of morphology evolution of V2O3 nanostructures
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of V2O3 nanostructures obtained by the sol-gel with different reaction conditions. The xerogel powder was annealing under a reducing atmosphere (94% Ar, 6% H2) in the temperature range 350-700C. The results show that the morphology dependent on the annealing temperature.
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SEM micrographs of the V2O5 coatings after thermal treatment under reducing atmosphere
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of V2O5 coatings on the silicon substrate after thermal treatment under a reducing atmosphere. Thin films were annealed at 600C and 700C for 10 under a reducing atmosphere (94% Ar, 6% H2).
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SEM micrographs of V2O5 thin film morphology dependent on substrate types
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of V2O5 thin film morphology dependent on substrate types. The as-prepared thin films were deposited on alumina, zirconium, zirconium oxide and metallic vanadium substrate, then was annealing under an oxidizing atmosphere at 600C for 10h. The results show that the morphology of...
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SEM micrographs of morphology evolution of V2O5 thin films on silicon substrate
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of V2O5 thin films deposited on a silicon substrate. The as-prepared thin films were annealing under an oxidizing atmosphere in the temperature range 250-600C. The results show that the morphology of the films dependent on the annealing temperature.
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STRUCTURE AND MAGNETIC PROPERTIES OF Bi5Ti3FeO15 CERAMICS PREPARED BY SINTERING, MECHANICAL ACTIVATION AND EDAMM PROCESS. A COMPARATIVE STUDY
PublikacjaThree different methods were used to obtain Bi5Ti3FeO15 ceramics, i.e. solid-state sintering, mechanical activation (MA) with subsequent thermal treatment, and electrical discharge assisted mechanical milling (EDAMM). The structure and magnetic properties of produced Bi5Ti3FeO15 samples were characterized using X-ray diffraction and Mössbauer spectroscopy. The purest Bi5Ti3FeO15 ceramics was obtained by standard solid-state sintering...
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Interaction of 4-nitrothiophenol with low energy electrons: Implications for plasmon mediated reactions
PublikacjaThe reduction of 4-nitrothiophenol (NTP) to 4-4′-dimercaptoazobenzene (DMAB) on laser illuminated noble metal nanoparticles is one of the most widely studied plasmon mediated reactions. The reaction is most likely triggered by a transfer of low energy electrons from the nanoparticle to the adsorbed molecules. Besides the formation of DMAB, dissociative side reactions of NTP have also been observed. Here, we present a crossed electron-molecular...
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A Computational Analysis of the Aerodynamic and Aeromechanical Behavior of a Thermo-Well for Steam Temperature Measurement in a Steam Turbine
PublikacjaThe goal of the paper is twofold: firstly, it presents computational fluid dynamics analysis for finding maximum unsteady flow forces (and their frequencies) acting on a thermo-well for measuring steam temperature in a steam turbine control stage and secondly, it presents computational solid dynamics analysis of possibility of entry into resonance of the thermowell structure. There have been analyzed two cases of flow with changing...
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Semi-adaptive feedback active control of MRI noise
PublikacjaA feedback controller is proposed for cancellation of magnetic resonance imaging (MRI) noise. The design of the controller takes into account specific features of the MRI noise signal. Simulation results show that a considerable rejection rate of the MRI noise can be obtained.
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SEM micrographs of NH4VO3 crystals
Dane BadawczeThe DataSet contains the scanning electron microscopy (SEM) micrographs of NH4VO3 crystals obtained by the LPE-IonEx method. The SEM images clearly show that the morphology of the end product can be nicely tuned by changing the type of ammonium salt and the solvent. It can be concluded that the used solvent affected crystal shapes and their size was...
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Andrzej Okuniewski dr inż.
OsobyWykształcenie 2010-2014: Katedra Chemii Nieorganicznej, Wydział Chemiczny, Politechnika Gdańskadoktor nauk chemicznych (nauki chemiczne – chemia, chemia nieorganiczna) 2009-2010: Wydział Chemiczny, Politechnika Gdańskamagister chemii (chemia stosowana) 2005-2009: Wydział Chemiczny, Politechnika Gdańskainżynier chemik (chemia stosowana) 2002-2005: II Liceum Ogólnokształcące im. Władysława Pniewskiego w Gdańskuprofil biologiczno-chemiczno-fizyczny...
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Kinetic analysis of the stage for a high speed steam turbine
PublikacjaThis article analyzes possibilites of resonances within a control stage for a high speed steam turbine. This stage hase been based on assembling of a single blade to a rotating disk and increasing of rigidity of the system by using of a bandage. In the analysis will be nd a possiblity of resonance frequency, and mistuning by showing safety working ranges. The calculations have bean used the3D modal and harmonic analysis by the...
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Spectroscopic and magnetic studies of highly dispersible superparamagnetic silica coated magnetite nanoparticles
PublikacjaSuperparamagnetic behavior in aqueously well dispersible magnetite core-shell Fe3O4@SiO2 nanoparticles is presented. The magnetic properties of core-shell nanoparticles were measured with use of the DC, AC magnetometry and EPR spectroscopy. Particles were characterized by HR-TEM and Raman spectroscopy, showing a crystalline magnetic core of 11.5 ± 0.12 nm and an amorphous silica shell of 22 ± 1.5 nm in thickness. The DC, AC magnetic...
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Synthesis and properties of HoT2Al20 (T = Ti, V, Cr) intermetallic cage compounds
PublikacjaPolycrystalline samples of HoT2Al20 (T = Ti, V, Cr) intermetallics were synthesized using a step-wise arc-melting technique. All three compounds adopt the CeCr2Al20-type crystal structure with Ho atoms positioned inside oversized icosahedral cages formed by Al atoms. The structure of HoV2Al20 compound is reported. The materials properties were studied by means of electrical resistivity, magnetic susceptibility, and specific heat...
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Flow structure, heat transfer and scaling analysis in the case of thermo-magnetic convection in a differentially heated cylindrical enclosure
PublikacjaThe experimental, numerical and scaling analysis in the case of thermo-magnetic convection in a thermosyphon-like enclosure filled with a paramagnetic fluid is presented. Visualization of temperature field together with the numerical simulation gave an information about the flow structure, which indicated “finger-like” structures of hot and cold streams advecting each other. Their number depended on the Rayleigh number and also...
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X-Ray Diffraction, Mössbauer Spectroscopy and Magnetoelectric Effect Studies of Multiferroic Bi5Ti3FeO15 Ceramics
PublikacjaBi5Ti3FeO15 ceramics belongs to multiferroic class of materials. In this work it was prepared by solid-state sintering method and investigated by X-ray diffraction, Mössbauer spectroscopy, and magnetoelectric effect measurements. As it was proved by X-ray diffraction studies the single-phase Bi5Ti3FeO15 compound was obtained. The Mössbauer investigations revealed paramagnetic character of the compound at room temperature as well...
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Study of ultraviolet-visible fluorescence emission following resonant Auger decay of the 2p-1nl core-excited states of argon atoms
PublikacjaWe have studied the excitation and relaxation of Ar+ ions populated in resonant Auger decay from the Ar 2p−1nl core-excited states by using ultraviolet-visible fluorescence spectroscopy and photon-photon delayed coincidence technique. Fluorescence emission yields were measured in the photon energy range of 240-–255 eV for the 3s23p4(1D)5s(2D) → 3s23p4(1D)4p(2F) (393 nm) and 3s23p4(1D)4d(2F) → 3s23p4(1D)4p(2F) (335 nm) transitions...
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SEM micrographs of the austenitic stainless steel corrosion in asphalt fumes
Dane BadawczeThe dataset contains the scanning electron microscopy (SEM) studies of the austenitic stainless steels: AISI 304, AISI 316, AISI 321 and duplex stainless steel AISI 2205. The samples were polished and exposed to the installation carrying asphalt fumes at elevated temperatures (approx. ~210-240 Celsius). The exposition duration was three months. Some...
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Techniki zwiększania efektywności metody elementów skończonych poprzez redukcję dziedziny obliczeniowej z wykorzystaniem własności geometrii struktur
PublikacjaWspółczesna elektronika ze względu na swój szybki rozwój wymaga od nas efektywnego modelowania zjawisk polowych. Celem rozprawy jest zwiększanie efektywności metody elementów skończonych poprzez redukcję dziedziny obliczeniowej z wykorzystaniem własności geometrii struktur oraz jej hybrydyzację z użyciem technik analitycznych. Rozprawa zawiera przegląd stanu wiedzy na temat dostępnych obecnie technik modelowania jak również opis...
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Experimental determination of H2 mass stopping powers for low-energy electrons
PublikacjaWe present experimental mass stopping powers of electrons in gaseous H2 obtained with an electron time- of-flight spectrometer, for the incident electron energy range of 11 to 25 eV. In our procedure, the average energy loss is derived from conversion of the measured electron time-of-flight spectra into equivalent electron energy-loss spectra. Our present results are compared with the only available experimental measurement and...
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Feasibility study of a Raman spectroscopic route to drug detection
PublikacjaWe present an surface-enhanced Raman spectroscopy (SERS) approach for detection of drugs of abuse in whole human blood. We utilize a near infrared laser with 830 nm excitation wavelength in order to reduce the influence of fluorescence on the spectra of blood. However, regular plasmon resonance peak of plasmonic nanoparticles, such as silver or gold fall in a much lower wavelength regime about 400 nm. Therefore, we have shifted...
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The effect of nanoparticles size on photocatalytic and antimicrobial properties of Ag-Pt/TiO2 photocatalysts
PublikacjaAg-Pt-modified TiO2 nanocomposites were synthesized using the sol–gel method. Bimetallic modified TiO2 nanoparticles exhibited improved photocatalytic activity under visible-light irradiation, better than monometallic Ag/TiO2 and Pt/TiO2 nanoparticles (NPs). All modified powders showed localized surface plasmon resonance (LSPR) in visible region. The photocatalysts’ characteristics by X-ray diffractometry (XRD), scanning transmission...