Wyniki wyszukiwania dla: EXPERIMENTAL SPECTRA
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Analysis of experimental and simulated vibrational spectra for the antiferroelectric liquid crystal 12OBBB1M6
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Study of the Experimental and Simulated Vibrational Spectra Together with Conformational Analysis of Thioether Cyanobiphenyl-Based Liquid Crystal Dimers
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Calculation of Vibrational Resonance Raman Spectra of Molecules Using Quantum Chemistry Methods
PublikacjaThe understanding and interpretation of experimental resonance Raman (RR) spectra can strongly benefit from theoretical simulations. These can be achieved by combining quantum chemistry (QC) methods to calculate the electronic and vibrational molecular properties, together with appropriate models and approximations to compute the Raman intensities. This chapter presents the main and most commonly employed approaches to calculate...
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Manifestation of Intermolecular Interactions in the IR Spectra of 2- and 4-Methylmethcathinones Hydrochlorides: DFT Study and Hirshfeld Surfaces Analysis
PublikacjaThis paper reports a Hirshfeld surfaces analysis of crystalline 2- and 4-methylmethcathinone (2-MMC and 4-MMC) hydrochlorides to analyze NH∙Cl and CH∙∙∙Cl intermolecular interactions and approve the formation of the NН2+–Cl– salt fragment in both 2-MMC∙HCl and 4-MMC∙HCl crystals. Two isomeric dimers were separated from the corresponding crystal packing to model IR spectra of the crystalline 2-MMC∙HCl...
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Sea spectra revisited
PublikacjaPokazano, 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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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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Polynomial analysis as a new way of describing dynamic impedance spectra – Differential and relative impedance spectra
PublikacjaModel measurements of an equivalent electrical system were carried out using the technique of Dynamic Electrochemical Impedance Spectroscopy. The measurement took the form of potentiodynamic changes imposed on the tested system. Using the possibility of continuous impedance measurements, an attempt was made to develop an original and innovative method of analyzing impedance spectrograms, which is termed polynomial analysis. As...
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Chemometric Method of Spectra Analysis Leading to Isolation of Lysozyme and CtDNA Spectra Affected by Osmolytes
PublikacjaW 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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The amplitude analysis of impedance spectra
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Algorithms of chemicals detection using raman spectra
PublikacjaRaman spectrometers are devices which enable fast and non-contact identification of examined chemicals. These devices utilize the Raman phenomenon to identify unknown and often illicit chemicals (e.g. drugs, explosives)without the necessity of their preparation. Now, Raman devices can be portable and therefore can be more widely used to improve security at public places. Unfortunately, Raman spectra measurements is a challenge...
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Anticrossing effects in Stark spectra of helium
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Local impedance spectra of organic coatings
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Local impedance spectra of organic coatings
PublikacjaPublikacja przedstawia nowe podejście do lokalnych spektroskopowych pomiarów impedancyjnych powłok organicznych, oparte o mikroskop sił atomowych pracujący w trybie kontaktowym. Pomiędzy nieporuszającą się igłę mikroskopu i podłoże metalowe pokryte powłoką epoksydową przyłożono serię sinusoidalnych napięciowych sygnałów pobudzenia w zadanym zakresie częstotliwości. W ten sposób zarejestrowano lokalne widma w trybie "frequency by...
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Substituent effect in theoretical VCD spectra
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Substituent effect in theoretical ROA spectra
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Differential analysis of dynamic immittance spectra
PublikacjaThis work presents a new approach to the analysis of immittance spectrograms of systems characterised by non-stationarity. The possibility of linking the evolution of the immittance response with changes in the parameters describing the system is achieved by introducing a spectrum in differential form. By using the above procedure, it becomes possible to separate elements with a dependence (or lack thereof) from an independent...
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Computer Support of Analysis of Optical Spectra Measurements
PublikacjaThe 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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Temperature influence on tyre/road noise frequency spectra
PublikacjaThe 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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Photoelectron and threshold photoelectron valence spectra of pyridine
Publikacja. The pyridine molecule has been examined by the means of photoelectron and threshold photoelectron spectroscopies. Ionization energies were determined for both outer and inner valence orbitals and new adiabatic values were also resolved. Vibronic structure associated with several states was assigned mainly to be due to C–C stretches and ring bends. Additionally a Rydberg state converging to 7b2 state was ascribed. The data shown...
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On dielectric spectra of thin copper phthalocyanine films
PublikacjaPraca przedstawia niskosygnałowe widma dielektryczne, w zakresie częstotliwości 25 Hz-1 MHz, układów kanapkowych takich jak złoto/ftalocyjanina miedzi/magnez i złoto/ftalocyjanina miedzi/złoto.Przeprowadzona analiza umożliwiła odróżnienie w odpowiedzi dielektrycznej oporności elektrod i polaryzacji sieci od procesów związanych z transportem elektrycznych, takich jak relaksacja nośników ładunku w obszarze ładunku przestrzennego...
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High pressure luminescence spectra of CaMoO4:Pr3+
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The time dependence of pit creation impedance spectra
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Calculation of vibrational spectra for cyanobiphenyl liquid crystals
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The time dependence of pit creation impedance spectra.
PublikacjaPrzeprowadzono pomiar impedancyjny w warunkach chronoamperometrycznych uzyskując zmiany impedancji układu w czasie. Na ich podstawie wyznaczono zmiany rezystancji przeniesienia ładunku i pojemności w czasie opisujące inicjację i rozwój korozji wżerowej. Potwierdzono użyteczność dynamicznej elektrochemicznej spektroskopii impedancyjnej w badaniu korozji wżerowej.
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Higher-Order Spectra in Nanoparticle Gas Sensors.
PublikacjaPrzedstawiono wyniki badań rezystancji fluktuacji w rezystancyjnych sensorach gazu wykonanych z nanocząstek Pdx(WO3)1-x dla x=0.01 oraz x=0.12. Rozkład prawdopodobieństwa obserwowanych fluktuacji wskazywał na występowanie składowej o rozkładzie różnym od rozkładu normalnego. Do jego scharakteryzowania wykorzystano spektra wyższych rzędów oraz ich przekroje.
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Computer support of analysis optical spectra measurements
PublikacjaVerification of measurement errors has a big impact on assessment of 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 Fabry-Perot interferometer working in the transmission mode. In measurement setup, a 1310 nm superluminescent...
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Ambiphilic phosphorous compounds
Dane BadawczeResults of theoretical and experimental studies on ambiphilic phosphorous compounds:
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Hydration of amino acids: FTIR spectra and molecular dynamics studies
PublikacjaThe 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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Rengel Cane Sia Doctoral Candidate
OsobyI'm Rengel, born and raised in the Philippines. As an undergraduate I did kinetic modeling on Copper-catalyzed atom transfer radical addition (ATRA). Then I was inspired to do both theoretical and experimental studies, which led me to propose my master's thesis on Synthesis, Computational, Electrochemical, and Photoconductivity Studies on Naphthalene and its derivatives. This led to a master's degree in Chemistry in the Mindanao...
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Comparison of modelling and measurement results of spectra emitted by a programmable lamp
PublikacjaNowadays 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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Core–shell excitation of isoxazole at the C, N, and O K-edges – an experimental NEXAFS and theoretical TD-DFT study
PublikacjaThe near-edge X-ray absorption fine structure (NEXAFS) spectra of the gas-phase isoxazole molecule have been measured by collecting total ion yields at the C, N, and O K-edges. The spectral structures have been interpreted using time-dependent density functional theory (TD-DFT) with the short-range corrected SRC2-BLYP exchange–correlation functional. Experimental and calculated energies of core excitations are generally in good...
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Application of wave spectra to mathematical model of multihull vessel
PublikacjaDynamiczne układy mechaniczne reprezentujące obiekty pływające są ściśle związane z procesami stochastycznymi. Zmienne stanu i parametry wejścia w tych modelach mają charakter probabilistyczny. Modele matematyczne takich układów są reprezentowane przez układy stochastycznych równań różniczkowych tworząc układy równań ''Ito''. W artykule zostały wyznaczone współczynniki transmitancji dla wybranych trzech widm falowania: Kongresu...
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Application of higher order spectra in the electrochemical noise analysis
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Theoretical description of the measuring method of instantaneous impedance spectra
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Gaussian mixture decomposition in the analysis of MALDI-TOF spectra
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Language specific spectra generated in the human vocal tract
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Analysis of the vibrational spectra of chiral liquid crystalline thioesters
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Frequency response spectra applied to assess efficiency of the training techniques
PublikacjaThe 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
PublikacjaWeigh-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...
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Ambiphilic phosphorous compounds 2
Dane BadawczeResults of theoretical and experimental studies on ambiphilic phosphorous compounds:
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Vapor correction of FTIR spectra – A simple automatic least squares approach
PublikacjaFTIR 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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Visualizing spatially decomposed intermolecular correlations in the infrared spectra of aprotic liquids
PublikacjaInfrared (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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Consideration of dynamic loads in the determination of axle load spectra for pavement design
PublikacjaAxle 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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Influence of orientational disorder on the optical absorption properties in hybrid metal‐halide perovskite CH3NH3PbI3. A combined DFT/TD‐DFT and experimental study.
PublikacjaAn experimental and theoretical investigation is reported to analyze the relation between the structural and absorption properties of CH3NH3PbI3 in the tetragonal phase. More than 3000 geometry optimizations were performed in order to reveal the structural disorder and to identify structures with the lowest energies. The electronic structure calculations provide an averaged band gap of 1.674 eV, which is in excellent agreement...
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Raman Spectra Measurements for Chemical Identifications - Aspect of Uncertainty Sources and Reduction of Their Effects
PublikacjaRaman spectrometers enable fast and non-contact identification of examined chemicals. These devices measure Raman spectra and compare with the spectra database to identify unknown and often illicit chemicals (e.g. drugs, explosives) usually without any sample preparation. Raman spectra measurements are a challenge due to noise and interferences present outside the laboratories (field applications). The design of a portable Raman...
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Proton hydration in aqueous solution: FTIR studies of HDO spectra
PublikacjaW artykule scharakteryzowano sfery hydratacyjne protonu w roztworze wodnym na podstawie pomiarów widm FTIR wody półciężkiej (HDO), rozcieńczonej izotopowo w H2O. Wyniki eksperymentalne skonfrontowano z obliczonymi metodami chemii kwantowej strukturami niewielkich klasterów wodnych typu H+(H2O)n. Otrzymane geometrie optymalne porównano z odległościami międzyatomowymi otrzymanymi na podstawie położeń pasm HDO. Pierwsza sfera hydratacyjna...
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High pressure luminescence and time resolved spectra of La2Be2O5:Pr3+
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High pressure luminescence and time resolved spectra of LiNbO3:Pr3+
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Instantaneous impedance spectra of a non-stationary model electrical system
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Hydration of simple amides. FTIR spectra of HDO and theoretical studies
PublikacjaZastosowano metodę ważonych widm różnicowych do opisu hydratacji amidów w roztworach wodnych: formamidu, N-metyloformamidu, N,N-dimetyloformaidu, acetamidu, N-metyloacetamidu, N,N-dimetyloacetamidu. Narzędziem wspomagającym interpretację wyników eksperymentalnych są struktury agregatów solwatacyjnych wokół cząsteczki substancji rozpuszczonej uzyskane na podstawie obliczeń teoretycznych metodą ab initio z korelacją elektronową...