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Search results for: RESONANCE RAMAN-SPECTRA
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Raman spectroscopy analysis of molecular configuration forms of the macular xanthophylls
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Portable raman spectrometer for maritime security applications
PublicationThe fast identification of explosives, narcotics and other chemicals carried on board of ships or transported in containers to the harbors is an important problem of maritime security. Raman spectroscopy is widely used for fast identification of various chemicals. Continuous progress in the field of photonics has resulted in commercial availability of low-power compact Raman spectrometers which can be integrated into portable systems....
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Surface Science Spectra
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Optical method for verification of homogeneity of phantoms for calibration of magnetic resonance
PublicationThe primary purpose of this study was to develop a laboratory photonic set-up for characterisation of homogeneity of gel phantoms for calibration of magnetic resonance. In this system, optical coherence tomography allows the detection of micro- and macroscopic heterogeneities of a structure. The set-up was used to perform measurements of agar and agar-carrageenan gels, which are the basis for more complex phantoms for magnetic...
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IR and Raman study of oxy-nitride glasses
PublicationVarious silicate and phosphate glasses with and without nitride addition were structurally characterized by IR and Raman spectroscopy. The studied glass systems include Na-Ca-P-O-N (1), AE-Si-O-N (with AE=Mg, Ca, Sr, Ba)(2), La-Si-O-N (3) as well as the Na-(Li)-Be-O-(N) (4,5) system. The samples were prepared by different techniques such as remelting of pre-prepared glass samples of the oxide systems with Mg and/or Si3N4 powders...
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Prevention of resonance oscillations in gear mechanisms using non-circular gears
PublicationOne of the main disadvantages of gear mechanisms is the occurrence of noise and vibrations. This study investigated the applicability of non-circular gears for preventing resonance oscillations in gear mechanisms. The influence of a small deviation of the gear centrodes from the nominal circles on kinematic and oscillatory characteristics was analysed. It was shown that a larger deviation results in a smaller resonance amplitude...
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Computer-aided analysis of resonance risk in power system with Static Var Compensators
PublicationStatic Var Compensators operation in a power system may significantly improve voltage profiles in nodes and the reactive power balance, as well as ensure greater system stability in emergency conditions. However these devices may be a cause of a resonance in the system. The aim of this paper is to call attention to the need to include resonance phenomena in a compensator’s location evaluation process. The analysis performed in...
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Influence of Shunt Compensation with SVC Devices on Resonance Risk in Power Systems
PublicationMany analyses are required to locate a new reactive power source in a power system. The choice of a location is a very complex matter which requires various aspects to be considered. Selecting a location also entails the necessity to assess it from the point of view of the selected compensator’s structure as well as the system’s performance in various states with the new device on. The paper presents the issues of assessing compensator...
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Calculation of Resonance in Planar and Cylindrical Microstrip Structures Using a Hybrid Technique
PublicationA hybrid technique was employed for the analysis of the resonance frequency of thin planar and cylindrical microstrip structures with the patches of arbitrary geometry. The proposed technique utilizes a combination of Galerkin’s moment method and a finite-element method (FEM). In this approach, an FEM is adopted to calculate the patch surface current densities, and a method of moments is utilized to calculate the resonance frequencies...
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Ultra-thin film of aluminum oxide influence on the plasmon resonance in gold nanostructures
Open Research DataUltra-thin film of aluminum oxide influence on the plasmon resonance in gold nanostructures was measured by UV-VIS spectroscopy. Ultra thin film of Al2O3 was deposited on a gold nanostructures. Thickness of film was 2nm - 8nm. Shift of plasmon resonance was observed, as a result of various dielectric constant of layer.
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Monotone iterative method for first-order differential equations at resonance
PublicationThis paper concerns the application of the monotone iterative technique for first-order differential equations involving Stieltjes integrals conditions. We discuss such problems at resonance when the measure in the Stieltjes integral is positive and also when this measure changes the sign. Sufficient conditions which guarantee the existence of extremal, unique and quasi-solutions are given. Three examples illustrate the results.
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Vapor correction of FTIR spectra – A simple automatic least squares approach
PublicationFTIR spectroscopy is one of the best techniques to study intermolecular interactions. However, such an application requires high quality spectra with as little noise as possible, which are often difficult to obtain. One of the main sources of unwanted interference is water vapor. Here a robust method is proposed for automatic, fast and reliable vapor correction of FTIR spectra. The presented least squares approach of vapor subtraction...
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Non-invasive blood glucose monitoring with Raman spectroscopy: prospects for device miniaturization
PublicationThe number of patients with diabetes has reached over 350 million, and still continues to increase. The need for regular blood glucose monitoring sparks the interest in the development of modern detection technologies. One of those methods, which allows for noninvasive measurements, is Raman spectroscopy. The ability of infrared light to penetrate deep into tissues allows for obtaining measurements through the skin without its...
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Magnetic Resonance
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Visualizing spatially decomposed intermolecular correlations in the infrared spectra of aprotic liquids
PublicationInfrared (IR) spectroscopy is commonly used to study intermolecular interactions in the liquid phase, including solvation phenomena. On the other hand, ab initio molecular dynamics (AIMD) simulations offer the possibility to obtain IR spectra from first principles. Surpassing the experiment, AIMD simulations can deliver additional information on the spatial intermolecular correlations underlying the IR spectrum of the liquid. Although...
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Temperature influence on tyre/road noise frequency spectra
PublicationThe correction for temperature effect on measured tyre/road noise is very important as it may be one of the main sources of errors in measurement results due to substantial influence of this parameter on obtained values. The latest version of the Technical Specification ISO/CD TS 13471-1 about Temperature Corrections contains a proposal of correction procedure for normalizing measured noise levels to a reference air temperature...
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Hydration of amino acids: FTIR spectra and molecular dynamics studies
PublicationThe hydration of selected amino acids, alanine, glycine, proline, valine, isoleucine and phenylalanine, has been studied in aqueous solutions by means of FTIR spectra of HDO isotopically diluted in H2O. The difference spectra procedure and the chemometric method have been applied to remove the contribution of bulk water and thus to separate the spectra of solute-affected HDO. To support interpretation of obtained spectral results,...
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Detection of Denatonium Benzoate (Bitrex) Remnants in Noncommercial Alcoholic Beverages by Raman Spectroscopy
PublicationIllegal alcoholic beverages are often introduced into market using cheap technical alcohol, which is contaminated by denatonium benzoate (Bitrex) of very small concentration. Bitrex is the most bitter chemical compound and has to be removed before alcohol consumption. The home-made methods utilize sodium hypochlorite to disintegrate particles of denatonium benzoate in alcohol and to remove bitter taste before trading. In this experimental...
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Consideration of dynamic loads in the determination of axle load spectra for pavement design
PublicationAxle load spectra constitute a crucial part of the data for pavement design and pavement distress analysis. Typically, axle load spectra represent static load from vehicles and do not include dynamic loads generated by vehicles in motion. While dynamic loads can significantly contribute to faster pavement distress, this fact is mostly omitted in pavement design methods. The paper presents a methodology for consideration of dynamic...
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Design and modeling of the piezoelectric motor based on three resonance actuators
PublicationThis paper describes a piezoelectric motor which combines advantages from two existing piezoelectric motors topologies. The research work presents the design, simulations and measurements of the piezoelectric motor with three rotation-mode actuators. The aim of the project was to obtain the high speed piezoelectric motor. Other advantages of this conception are blocking torque, short response times, the ability to work in a hostile...
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EARTHQUAKE SPECTRA
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Self-healing mechanism of metallopolymers investigated by QM/MM simulations and Raman spectroscopy
PublicationThe thermally induced self-healing mechanisms in metallopolymers based on bisterpyridine complexes of iron(II) sulfate and cadmium(II) bromide, respectively, were studied by means of combined quantum mechanical/molecular mechanical (QM/MM) simulations and Raman spectroscopy. Two possible healing schemes, one based on a decomplexation of the cross-linking complexes and a second one relying on the dissociation of ionic clusters,...
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Computer Support of Analysis of Optical Spectra Measurements
PublicationThe verification of measurement errors has a big impact on the assessment of the accuracy of conducted measurements and obtained results. In many cases, computer simulation results are compared with measurement results in order to evaluate measurement errors. The purpose of our research was to check the accuracy of measurements made with a Fabry–Perot interferometer working in the transmission mode. In the measurement setup, a...
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Sea spectra revisited
PublicationPokazano, że widma falowania ITTC, wywodzące się z widma Bretschneidera, zależnego od dwóch parametrów, można zredukować do wspólnego widma bezwymiarowego, co oznacza, że są one geometrycznie powinowate. To samo dotyczy widma JONSWAP, które dodatkowo charakteryzuje trzeci paprametr, związany z kształtem piku. Umożliwia to aproksymację tych widm za pomocą rozkładu log-normalnego, co zapewnia realistyczny parametr szerokości widma,...
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DETERMINATION OF SP3 FRACTION IN ta-C COATING USING XPS AND RAMAN SPECTROSCOPY
PublicationThe paper presents results of studies on the structure of tetrahedral amorphous carbon films (ta-C) with a thickness in the range from 20 to 280 nm, deposited using pulsed vacuum arc technique with an electromagnetic Venetian blind plasma filter. The results of the phase structure analysis, obtained using visible Raman spectroscopy and UV Raman spectroscopy methods, showed a strong dependence of the results on the presence, on...
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Resonance microstrip structure with patch of arbitrary convex geometry with the use of field matching technique
PublicationAn analysis of the resonance frequency problem of planar microstrip structure with patch of arbitrary convex geometry is presented. A full-wave analysis is employed utilizing a combination of Galerkin’s moment method and field matching technique. In this approach, a field matching technique is adopted to calculate the patch surface current densities, and next the method of moments is utilized to calculate resonance frequencies...
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Resonance Frequency Calculation of Spherical Microstrip Structure Using Hybrid Technique
PublicationIn this paper the spherical microstrip structure is considered. The structure is composed of a metallic patch with an arbitrary shape placed on a dielectric coated metallic sphere. In the analysis the hybrid technique is utilized. In this approach the finite-difference technique is applied in a cavity model to determine the current basis functions on the patch. Next, using method of moments, the resonance frequency of the structure...
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Time domain model of the resonance-based electromagnetic pulses emission system
PublicationIn the literature, the emission properties of the electromagnetic field pulse systems based on high voltage antennas (HVR) have been widely described. In order to increase the emission efficiency by extending duration and increasing amplitude of the impulse it is possible to use a resonance system tuned to the parameters of the signal shaped in the pulse forming circuit. The synthesis of a time-domain simulation model of a complex...
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The Optical Coherence Tomography and Raman Spectroscopy for Sensing of the Bone Demineralization Process
PublicationThe presented research was intended to seek new optical methods to investigate the demineralization process of bones. Optical examination of the bone condition could facilitate clinical trials and improve the safety of patients. The authors used a set of complementary methods: polarization-sensitive optical coherence tomography (PS-OCT) and Raman spectroscopy. Chicken bone samples were used in this research. To stimulate in laboratory...
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Comparison of modelling and measurement results of spectra emitted by a programmable lamp
PublicationNowadays artificial light with an optimized spectrum is used in many different applications. For instance, it is widely used in museums and exhibitions to illuminate the art. Moreover, such light stimulates the growth of plants, or can be applied in industry and healthcare. To achieve the best results for each application, the adjusting of a dedicated spectrum is required, which is a complicated task. The ongoing research is focused...
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Decomposition of halogenated nucleobases by surface plasmon resonance excitation of gold nanoparticles
PublicationHalogenated uracil derivatives are of great interest in modern cancer therapy, either as chemotherapeutics or radiosensitisers depending on their halogen atom. This work applies UV-Vis spectroscopy to study the radiation damage of uracil, 5-bromouracil and 5- uorouracil dissolved in water in the presence of gold nanoparticles upon irradiation with an Nd:YAG ns-pulsed laser operating at 532nm at dierent uences. Gold nanoparticles...
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Electrochemically directed biofunctionalization of a lossy-mode resonance optical fiber sensor
PublicationIn this work, we present a direct electrochemical biofunctionalization of an indium-tin-oxide-coated lossy-mode resonance optical fiber sensor. The functionalization using a biotin derivative was performed by cyclic voltammetry in a 10 mM biotin hydrazide solution. All stages of the experiment were simultaneously verified with optical and electrochemical techniques. Performed measurements indicate the presence of a poly-biotin...
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Nanodiamonds Doped with Manganese for Applications in Magnetic Resonance Imaging
PublicationNanodiamonds (NDs) are emerging with great potential in biomedical applications like biomarking through fluorescence and magnetic resonance imaging (MRI), targeted drug delivery, and cancer therapy. The magnetic and optical properties of NDs could be tuned by selective doping. Therefore, we report multifunctional manganese-incorporated NDs (Mn-NDs) fabricated by Mn ion implantation. The fluorescent properties of Mn-NDs were tuned...
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Resonance Frequency Calculation of a Multilayer and Multipatch Spherical Microstrip Structure Using a Hybrid Technique
PublicationThis communication offers a rigorous analysis of the resonance frequency problem of a spherical microstrip structure mounted on a multilayer, dielectric-coated metallic sphere, with an electrically small radius. The structure consists of single or multiple metallic patches with arbitrary shapes. A full-wave analysis is employed with the use of proposed hybrid approach, combining the finite-difference technique with a spectral domain...
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Ultrastructural analysis of the submandibular sialoliths: Raman spectroscopy and electron back-scatter studies
PublicationThe aim of work was the epidemiological analysis of the occurrence of sialolithiasis of the submandibular gland in adults and the evaluation of the ultrastructure of salivary stones. The study sample consisted of 44 sialoliths. Analysis of the structure and chemical composition of sialoliths was performed using a Scanning Electron Microscope and Raman Spectroscopy. Comparing our results with the literature we can say that the epidemiology...
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JOURNAL OF RAMAN SPECTROSCOPY
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On ship roll resonance frequency
PublicationThe paper deals with the problem of modeling of rolling motion under a variety of excitation parameters. Special emphasis is put on the analysis and prediction of the frequency of the resonant mode of rolling, since it is often an essential issue in terms of motion of a ship related to her safety against capsizing or excessive amplitudes of roll. The research is performed for both free rolling and excited rolling and it is based...
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Raman studies of ferroelectric ceramics.
PublicationPrzedstawiono potencjał aplikacyjny spektroskopii Ramana w diagnostyce procesu technologicznego wytwarzania cienkowarstwowych struktur perowskitowych o strukturze Ba(Ti1 xZrx)O3, posiadających możliwość strojenia przenikalności elektrycznej za pomocą pola elektrycznego. Skonfigurowano systemy pomiarowe do badania zarówno próbek objętościowych, jak i struktur cienkowarstwowych. Zidentyfikowano najistotniejsze linie w widmach ramanowskich,...
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Chemometric Method of Spectra Analysis Leading to Isolation of Lysozyme and CtDNA Spectra Affected by Osmolytes
PublicationW niniejszej pracy zaprezentowana została chemometryczna metoda analizy danych widmowych, prowadząca do wyizolowania widm FTIR biomakrocząsteczek (lizozymu z białka jaja kurzego i ctDNA) zaburzonych przez wybrane osmolity (TMAO, betainę) w roztworach wodnych. Została ona oparta na metodzie widm różnicowych, wykorzystywanej pierwotnie do określania struktury rozpuszczalnika wokół cząsteczek substancji rozpuszczonej. Cykliczne wykorzystanie...
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FTIR, Raman spectroscopy and HT-XRD in compatibility study between naproxen and excipients
PublicationDetection of incompatibility between an active pharmaceutical ingredient (API) and excipients, including the selection of the most biopharmaceutical advantageous excipients is extremely important in the pre-formulation process of developing a solid dosage form technology. Therefore, having fast and reliable methods for identifying incompatibility is fundamental in pharmaceutical technology. For this purpose, combined Fourier transform...
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AMCA to TAMRA long range resonance energy transfer on a flexible peptide
PublicationFörster resonance energy transfer between 7-amino-4-methyl-3-coumarinylacetic acid, (AMCA, donor) and 5- carboxytetramethylrhodamine, (TAMRA, acceptor) bound to Lys(AMCA)-Gly-Pro-Arg-Ser-Leu-Ser-Gly-Lys (TAMRA)-NH2 peptide is demonstrated by various spectroscopic techniques in glycerol at room temperature. In particular, nonexponential character of fluorescence intensity decay evidences the distance distribution between the donor...
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Case studies of resonance phenomena in high voltage overhead power lines with shunt reactors
PublicationMisguided design of the towers of power transmission lines can lead to serious problems such as voltage asymmetry, overvoltages, electric arc extinction difficulties or resonance – in case of double circuit line with shunt reactors. The paper points out those threats on example of 400 kV double circuit overhead transmission line with shunt reactors.
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Towards spectroscopic monitoring of photoelectrodes: In-situ Raman photoelectrochemistry of a TiO2/prussian blue photoanode
PublicationHere, novel in-situ Raman photoelectrochemical measurements are performed. The obtained results have proved that it is possible to track the progress of a photoelectrochemical reaction that takes place on a semiconducting electrode using the spectroscopic method. As an exemplary system, the Ti/TiO2/Prussian blue electrode is investigated. Since TiO2 is an n-type semiconductor, it cannot act as an efficient anode in dark conditions....
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Drop-coating deposition surface-enhanced Raman spectroscopy on silver substrates for biofluid analysis
PublicationUtilization 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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The amplitude analysis of impedance spectra
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Nanodiamond phantoms mimicking human liver: perspective to calibration of T1 relaxation time in magnetic resonance imaging
PublicationPhantoms of biological tissues are materials that mimic the properties of real tissues. This study shows the development of phantoms with nanodiamond particles for calibration of T1 relaxation time in magnetic resonance imaging. Magnetic resonance imaging (MRI) is a commonly used and non-invasive method of detecting pathological changes inside the human body. Nevertheless, before a new MRI device is approved for use, it is necessary...
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Hyperelastic Microcantilever AFM: Efficient Detection Mechanism Based on Principal Parametric Resonance
PublicationThe impetus of writing this paper is to propose an efficient detection mechanism to scan the surface profile of a micro-sample using cantilever-based atomic force microscopy (AFM), operating in non-contact mode. In order to implement this scheme, the principal parametric resonance characteristics of the resonator are employed, benefiting from the bifurcation-based sensing mechanism. It is assumed that the microcantilever is made...
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A study of the photoelectron spectra of α-tetrahydrofurfuryl alcohol over the outer valence energy region (9–25 eV)
PublicationPhotoelectron spectra of α-tetrahydrofurfuryl alcohol (THFA) molecules, the threshold spectrum and spectra for constant photoelectron energies, have been measured over the photon energy range 9–25 eV. Analysis of the photoelectron spectra has allowed overlapping photoionization bands to be separated, tentatively assigned and their vertical photoionization energies to be determined. These energies are compared with existing theoretical...
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Frequency response spectra applied to assess efficiency of the training techniques
PublicationThe purpose of the research is to assess the increase of the muscle strength and power. Movement of the human body when the moving one impacts a stationary or moving body is taken under consideration. The waveform produced by an impact is transformed into frequency domain. The acceleration record is transformed as a complex spectrum, by the use of a Discrete Fourier Transformation. In this paper the applications of the discrete...
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Study on the accuracy of axle load spectra used for pavement design
PublicationWeigh-in-Motion (WIM) systems are used in order to reduce the number of overloaded vehicles. Data collected from WIM provide characteristics of vehicle axle loads that are crucial for pavement design as well as for the development of pavement distress prediction models. The inaccuracy of WIM data lead to erroneous estimation of traffic loads and in consequence inaccurate prediction of pavement distress process. The objective of...