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Wyniki wyszukiwania dla: UV-Vis spectroscopy
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Measurement system for nonlinear surface spectroscopy by atomic force microscopy for corrosion processes monitoring
PublikacjaIn addition to traditional imaging the surface, atomic force microscopy (AFM) enables wide variety of additional measurements. One of them is higher harmonic imaging. In tapping mode the nonlinear contact between tip and specimen results in higher frequency vibrations. More information available from the higher harmonics analysis proves to be helpful for more detailed imaging. Such visualization is especially useful for heterogeneous...
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Low temperature broad band dielectric spectroscopy of multiferroic Bi6Fe2Ti3O18 ceramics
PublikacjaIn the present research the tool of broadband dielectric spectroscopy was utilized to characterize dielectric behavior of Bi6Fe2Ti3O18 (BFTO) Aurivillius-type multiferroic ceramics. Dielectric response of BFTO ceramics was studied in the frequency domain (Δν=0.1Hz – 10MHz) within the temperature range ΔT=-100°C – 200°C. The Kramers-Kronig data validation test was employed to validate the impedance data measurements and it was found...
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Biosilica from sea water diatoms algae—electrochemical impedance spectroscopy study
PublikacjaHere, we report on an electrochemical impedance study of silica of organic origin as an active electrode material. The electrode material obtained from carbonized marine biomass containing nanoporous diatoms has been characterised by means of XRD, IR, SEM and EIS. Dif- ferent kinds of crystallographic phases of silica as a result of thermal treatment have been found. The electrode is electrochemically stable during subsequent cyclic...
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Weak hydrogen bonding interaction S-H···O=C studied by FT-IR spectroscopy and DFT calculations
PublikacjaInteractions between the thiolate group of tri-tert-butoxysilanethiol (TBST) and carbonyl group of acetone are studied with the use of FT-IR spectroscopy and DFT calculations.
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New Method of Non-Linear Electrochemical Impedance Spectroscopy with an Amplitude-Modulated Perturbation Signal
PublikacjaThe paper presents a new method of non-linear electrochemical impedance spectroscopy (NLEIS), which allows fast and nondestructive evaluation of the corrosion rate and determination of the Tafel coefficients values for a corrosion system under investigation. This method employs amplitude modulation of the ac perturbation signal. The study demonstrated that it was possible to obtain impedance characteristic as a function of the...
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Application of galvanodynamic impedance spectroscopy for studying passive film cracking under mechanical strain
PublikacjaThe paper reports the results of simultaneous mechanical and electrochemical investigations on austenitic (18/8) stainless steel in a 2 % solution of sulphuric acid. The measurements were performed using Galvanodynamic Electrochemical Impedance Spectroscopy (GDEIS). Electrochemical analysis of mechanical passive layer cracking and repassivation conditions during a tensile test was carried out. Application of this methodology allowed...
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Spectroscopic studies of UV-irradiated poly(vinyl alcohol)/elastin blends
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Selection of the UV irradiation conditions for accelerated edible oil oxidation procedure.
PublikacjaCelem badań było dobranie optymalnych warunków etapu naświetlania olejów roślinnych z zastosowaniem promieniowania ultrafioletowego. Dobrano powierzchnię naświetlania i grubość filmu oleju, a także odległość próbki oleju od źródła światła i moc promieniowania ultrafioletowego.Lotne produkty utleniania izolowano przy pomocy mikroekstrakcji do fazy stacjonarnej i rozdzielano z zastosowaniem chromatografii gazowej z detektorem płomieniowo-jonizacyjnym.
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Influence of UV on the self-adhesive properties of silicone pressure-sensitive adhesives
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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 Direct Methanol Fuel Cell Process Dynamics Using Dynamic Electrochemical Impedance Spectroscopy
PublikacjaA new technique, which was developed to characterize the direct methanol fuel cell under work conditions, has been presented in this paper. The impedance measurements were made using dynamic electrochemical impedance spectroscopy research technique in the galvanostatic mode, using multiple sinusoidal excitation. Obtained results show, that together with an increase of the temperature and working load, the global impedance...
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Silicon oxycarbide-tin nanocomposite derived from a UV crosslinked single source preceramic precursor as high-performance anode materials for Li-ion batteries
PublikacjaIn this work, we report an innovative and facile UV light-assisted synthesis of a nanocomposite based on silicon oxycarbide (SiOC) and tin nanoparticles. SiOC ceramic matrix, containing a conductive free carbon phase, participates in lithium-ion storage, and buffers the volume changes of Li-alloying/de-alloying material. The reported synthesis procedure through a polymer-derived ceramic route involves the preparation of a single-source...
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Combined analysis of whole human blood parameters by Raman spectroscopy and spectral-domain low-coherence interferometry
PublikacjaIn this article the simultaneous investigation of blood parameters by complementary optical methods, Raman spectroscopy and spectral-domain low-coherence interferometry, is presented. Thus, the mutual relationship between chemical and physical properties may be investigated, because low-coherence interferometry measures optical properties of the investigated object, while Raman spectroscopy gives information about its molecular...
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Synthesis, spectroscopy and computational studies of some novelphosphorylated derivatives of quinoline-5,8-diones
PublikacjaThe neutral phosphorus nucleophiles such as R2P(=Y)M allowed the radical addition to 2-methyl-5,8-dioxo-5,8-dihydroquinoline-7-amine and N-(2-methyl-5,8-dioxo-5,8-dihydroquinolin-7-yl)acetamide giving exclusively O-phosphorylated products. All products were quantitatively prepared and characterized by microanalysis, and multinuclear NMR spectroscopy. Seven of them, have been characterized by single crystal X-ray diffraction method....
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Instantaneous electrochemical impedance spectroscopy of electrode reactions
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Optical spectroscopy and scintillation mechanisms ofCexLa1−xF3
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High pressure spectroscopy of chromium doped LiTaO3crystals
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Hydration of tetrahydrofuran derived from FTIR spectroscopy
PublikacjaZbadano hydratację THF na podstawie spektroskopii FTIR drgań HDO oraz H2O. Dane widmowe poddano analizie przy pomocy ilościowej metody widm różnicowych. Ustalono, że w roztworach rozcieńczonych hydratacja THF typu hydrofobowego dominuje nad hydratacją typu elektrofilowego. Scharakteryzowano wodę w otoczce hydratacyjnej THF poprzez jej porównanie z wodą czystą.
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Evaluation of coating systems using impedance spectroscopy
PublikacjaTrwałość powłokowych systemów ochronnych zależy od oddziaływań środowiska i związana jest nieodwracalnymi procesami chemicznymi i fizycznymi. Zastosowanie spektroskopii impedancyjnej pozwala na określenie obszaru zastosowań danej powłoki i prognozowanie okresu jej trwałości. W pracy zamieszczono przykłady oceny trwałości systemów powłokowych stosowanych w strategicznych konstrukcjach.
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Instantaneous electrochemical impedance spectroscopy of electrode reactions.
PublikacjaUstalona została ciągła transformata STFT sinusoidalnego sygnału pobudzeniai odpowiedzi prądowej dla pierwszorzędowej reakcji elektrodowej. Impedancja elektrodowa wyznaczona została w łącznej dziedzinie czasowo-częstotliwościowej. Wykonano pomiary reakcji redukcji Cd(II) na kapiącej elektrodzie rtęciowej w funkcji czasu. Zaprezentowano możliwość wyznaczania chwilowych widm impedancyjnych. Opisano czasowe charakterystyki rezystancji...
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Fluorescent spectroscopy of collagen as a diagnostic tool in medicine
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Noise sources in Raman spectroscopy of biological objects
PublikacjaWe present an overview of noise sources deteriorating the quality of the recorded biological Raman spectra and the ability to determine the specimen composition. The acquired Raman spectra exhibit intense additive noise components or drifts because of low intensity of the scattered light. Therefore we have to apply expensive or bulky measurement setups to limit their inherent noise or to apply additional signal processing to reduce...
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Study of the NO2 sensing mechanism of PEDOT-RGO film using in situ Raman Spectroscopy
PublikacjaIn this work, the mechanism of the NO2 reaction with PEDOT-RGO composite film has been investigated via in situ Raman spectroscopy. Reduced graphene oxide (RGO), poly(3,4-ethylenedioxytiophene)-reduced graphene oxide (PEDOT-RGO) and poly(3,4-ethylenedioxytiophene)/ClO4− (PEDOT/ClO4−) films were fabricated using an electrodeposition method and used as resistance sensors of gaseous nitrogen dioxide. The experimental results indicate...
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Validity of impedance spectra obtained by dynamic electrochemical impedance spectroscopy verified by Kramers-Kronig transformation.
PublikacjaArtykuł przedstawia weryfikację wiarygodności widm impedancyjnych otrzymanych za pomocą niedawno wprowadzonej techniki eksperymentalnej - Dynamicznej Elektrochemicznej Spektroskopii Impedancyjnej (Dynamic Electrochemical Impedance Spectroscopy, DEIS). Technika ta zakłada, że badany system jest pseudostacjonarny jeśli czas pomiaru jest odpowiednio krótki. Czas potrzebny na otrzymanie pojedynczego spektrum zależy od długości okna...
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Study of the Layer-Type BST Thin Film with X-ray Diffraction and X-ray Photoelectron Spectroscopy
PublikacjaIn the present paper, results of X-ray photoelectron studies of electroceramic thin films of barium strontium titanate, Ba1xSrxTiO3 (BST), composition deposited on stainless-steel substrates are presented. The thin films were prepared by the sol-gel method. A spin-coating deposition of BST layers with different chemical compositions was utilized so the layer-type structure of (0-2) connectivity was formed. After the deposition,...
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Drop-coating deposition surface-enhanced Raman spectroscopy on silver substrates for biofluid analysis
PublikacjaUtilization of surface-enhanced Raman spectroscopy as a measurement technique is of particular interest in biodetection due to its superb chemical specificity and high sensitivity. The use of SERS substrates further improve this method by massive enhancement of the molecule Raman spectrum, permitting very low levels of detection. Therefore it is important to seek for new ways to develop reliable substrates, which are quickly and...
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Distribution of relaxation times as a method of separation and identification of complex processes measured by impedance spectroscopy
PublikacjaImpedance spectroscopy is one of the most commonly performed measurements to characterize electronic and electrochemical systems. Impedance spectra have limited resolution and many different processes may overlap what could be the reason of obstructions in its proper later analysis. Up to date, there are three approaches to solve this problem: examining impedance spectra itself, fitting spectra with equivalent circuits, and calculating...
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A Probe into the Corrosion Behavior of a WE43B Magnesium Alloy in a Simulated Body Fluid using Dynamic Electrochemical Impedance Spectroscopy
PublikacjaWE43B is one of the newest Mg alloys with practical application in biomedical implant technology. This work attempts to scrutinize the corrosion characteristics of WE43B alloy in a simulated body fluid (SBF) at a typical body temperature. The dynamic-electrochemical impedance spectroscopy with the capacity to track changes on surfaces in a dynamic corrosive system is used in combination with other classical techniques namely, linear...
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Higher harmonics of the intensity modulated Photocurrent/Photovoltage spectroscopy response - a tool for studying photoelectrochemical nonlinearities
PublikacjaIn this work, a higher harmonic analysis (HHA) of the intensity modulated photocurrent/photovoltage (IMPS/IMVS) spectroscopy data is proposed as a potent tool for studying nonlinear phenomena in photoelectrochemical and photovoltaic systems. Analytical solutions of kinetic equations were constructed for cases of single and double resonance accounting for various sources of higher harmonics. These sources correspond to the physical...
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UV-induced electron transfer between triethylamine and 5-bromo-2′-deoxyuridine. A puzzle concerning the photochemical debromination of labeled DNA
Publikacja5-Bromo-2'-deoxyuridine (BrdU) photosensitizes DNA to strand break formation. However, this type of photodamage is completely quenched by the presence of triethylamine (TEA) which originates from RP-HPLC purification commonly employed by oligonucleotide providers. While the presence of TEA in oligonucleotide samples does not interfere with PCR or other molecular biology applications, the mechanism of photochemical reaction proceeding...
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Detoxification of parabens using UV-A enhanced by noble metals—TiO2 supported catalysts
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UV Radiation Detection Using Optical Sensor Based on Eu3+ Doped PMMA
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Visible emission in Sm3+and Tb3+doped phosphate glass excited by UV radiation
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The influence of UV-irradiation on the poly(vinyl alcohol)/hyaluronic acid film properties
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Kleje samoprzylepne sieciowane UV zawierające nienasycony fotoinicjator na bazie benzofenonu
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The Response of Pseudomonas aeruginosa PAO1 to UV-activated Titanium Dioxide/Silica Nanotubes
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Właściwości pigmentów kadmowych po narażeniach chemicznych i naświetlaniu promieniowaniem UV
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The influence of UV-radiation on hyaluronic acid and its blends with addition of collagen and chitosan
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Effect of UV radiation and chitosan coating on the adsorption-photocatalytic activity of TiO2 particles
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Effect of Melanin on the Stability of Casein Films Exposed to Artificially Accelerated UV Aging
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Selective adsorption of BTEX on calixarene-based molecular coordination network determined by 13C NMR spectroscopy
PublikacjaBenzene, toluene, ethylbenzene, and xylenes (BTEX), a class of volatile organic compounds, are harmful pollutants but also very important precursors in organic industrial chemistry. Among different approaches used for the BTEX treatment, the adsorption technology has been recognized as an efficient approach because it allows to recover and reuse both adsorbent and adsorbate. However, the selective adsorption of the components is...
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Influence of Leu5 configuration on the equilibrium constants of complexes of [Leu]-enkephalin with β-cyclodextrin studied by fluorescence spectroscopy, microcalorimetry and 1H NMR spectroscopy
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Electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy and ab initio calculations of ethyl acetate
PublikacjaThe high-resolution vacuum ultraviolet photoabsorption spectrum of ethyl acetate, C4H8O2, is presented over the energy range 4.5−10.7 eV (275.5−116.0 nm). Valence and Rydberg transitions and their associated vibronic series observed in the photoabsorption spectrum, have been assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator strengths. Also, the photoabsorption cross sections...
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Isobutyl acetate: electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy and ab initio calculations
PublikacjaThe high-resolution vacuum ultraviolet photoabsorption spectrum of isobutyl acetate, C6H12O2, is presented here and was measured over the energy range 4.3–10.8 eV (290–115 nm). Valence and Rydberg transitions with their associated vibronic series have been observed in the photoabsorption spectrum and are assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator strengths. The measured...
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Absorption spectroscopy setup for determination of whole human blood and blood–derived materials spectral characteristics
PublikacjaA dedicated absorption spectroscopy system was set up using tungsten-halogen broadband source, optical fibers, sample holder, and a commercial spectrometer with CCD array. Analysis of noise present in the setup was carried out. Data processing was applied to the absorption spectra to reduce spectral noise, and improve the quality of the spectra and to remove the baseline level. The absorption spectra were measured for whole blood...
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EXAMINATION OF SOL-GEL DERIVED HYDROXYAPATITE ENHANCED WITH SILVER NANOPARTICLES USING OCT AND RAMAN SPECTROSCOPY
PublikacjaHydroxyapatite (HAp) has been attracting widespread interest in medical applications. In a form of coating, it enables to create a durable bond between an implant and surrounding bone tissues. With addition of silver nanoparticles HAp should also provide antibacterial activity. The aim of this research was to evaluate the composition of hydroxyapatite with silver nanoparticles in a non-destructive and non-contact way. For control measurements...
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SEI Growth and Depth Profiling on ZFO Electrodes by Soft X-Ray Absorption Spectroscopy
PublikacjaZnFe2O4 (ZFO) Li-ion batteries (LIBs) represent a reliable, affordable, and safe energy storage technology for use in portable application. However, current LIB active materials (graphite, lithium/transition metal spinel or layered oxides, olivine structures) can store only limited energy since they rely on insertion storage based on solid-state host-guest interactions. Moreover, performances and durability of the cells are strongly...
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Three modes of electrochemical impedance spectroscopy measurements performed on vanadium redox flow battery
PublikacjaThis article presents an innovative approach to monitor working redox flow batteries using dynamic electrochemical impedance spectroscopy, diverging from the commonly sequential impedance methods carried out under potentiostatic or galvanostatic conditions close to the open circle voltage. The authors introduce a fresh variation of dynamic impedance measurement that leverages an amplitude-modulated multi-frequency alternating current...
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Application of Dynamic Impedance Spectroscopy to Scanning Probe Microscopy
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Application of dynamic impedance spectroscopy to atomic force microscopy
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