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Search results for: RESONANT ULTRASONIC SPECTROSCOPY
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Fast bubble dynamics and sizing
PublicationSingle bubble sizing is usually performed by measuring the resonant bubble response using the Dual Frequency Ultrasound Method. However, in practice, the use of millisecond-duration chirp-like waves yields nonlinear distortions of the bubble oscillations. In comparison with the resonant curve obtained under harmonic excitation, it was observed that the bubble dynamic response shifted by up to 20 percent of the resonant frequency...
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Studies on the influence of β-cyclodextrin derivatives on the physical stability of famotidine
PublicationThe usage of Fourier transform infrared spectroscopy, near infrared spectroscopy, differential scanning calorimetry and microscopy is presented in this work focused on the exploration of the effect of CD on the physical stability of famotidine (FAM). The most significant information was achieved by analysis of the second derivatives ofnear infrared (NIR) spectra recorded. Changes in the shape of spectra derivatives allow...
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Cross-sections for electron-scattering from 2-methyl-1-buten-3-yne, C 5 H 6 , molecules
PublicationtCross-sections for electron collisions with the 2-methyl-1-buten-3-yne [H2C C(CH3)C CH] moleculewere measured and calculated. Absolute grand-total electron-scattering cross-section (TCS) was takenat impact energies from 0.6 to 300 eV in the linear electron-transmission experiment. The TCS energydependence for the electron–C5H6collision has two prominent enhancements separated with a deepminimum located near 1.8 eV. In addition,...
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Modeling of the alcohol dehydrogenase active site. Two different modes of alcohol binding in crystals of zinc and cadmium tri-tert-butoxysilanethiolates evidenced by X-ray diffraction and solid state vibrational spectroscopy
PublicationOpisano syntezę, struktury cząsteczkowe oraz widma FT-IR, 1H. 13C, 29Si, 113Cd NMR dziesięciu nowych, mieszanoligandowych kompleksów cynku i kadmu z ligandem tri-tert-butoksysilanotiolanowym i pochodnymi imidazolu. Za pomocą rentgenowskiej analizy strukturalnej i spektroskopii w podczerwieni udokumentowano dwa różne sposoby wiązania etanolu i metanolu w kryształach tych związków. Opisane kompleksy stanowią modele miejsca aktywnego...
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APPLICATION OF THE HIGH FREQUENCY LINEARIZATION OF THE EAR IN PATIENTS WITH TINNITUS . Metoda linearyzacji narządu słuchu u osób cierpiących z szumami usznymi
PublicationThis paper summarises the problem of tinnitus, hypotheses on its causes and the treatment methods. Moreover, a hypothesis on tinnitus origins is explained, based on the mechanisms of the analog-to-digital conversion and quantization. In addition, this paper describes methods of determining the acoustic intensity and spectra of low- level ultrasonic signals, as well as impedance characteristics of an ultrasound transducer. Furthermore,...
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Raman investigation of the patina layers on Hungarian copper ingots from a fifteenth century shipwreck
PublicationWe report results of the patina study of underwater archeological finding ofmedieval copper objects performed by means of the Raman and complementary spectroscopic techniques. The objects were found submerged in the sea as cargo part of the ship which sunk in the Gulf of Gdańsk in 1408. The excavated collection consists of 230 oval ingots of the size and mass up to about 60 cm and 18 kg (total of 2 tons), respectively. In the Raman...
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Mode vibrations of plates – experimental analysis
PublicationIn this paper results of the square MDF plate and circular saw blades examination with the use of the harmonic method to static identification of resonant frequencies and shapes of mode vibrations are presented. Obtained results reveled that for circular saws with large holes in a saw blade appeared two resonant frequencies for the same nodal number.
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YSZ Thin film deposited on porous substrate by spray pyrolysis
PublicationIn this work the results of deposition of YSZ layer on a porous substrate using an ultrasonic Spray Pyrolysis are presented.
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Developments in ultrasound-assisted microextraction techniques for isolation and preconcentration of organic analytes from aqueous samples
PublicationThe great potential of ultrasonic assistance in sample preparation, especially extraction, is being recognized. In this review, we discuss the applications of ultrasonic radiation in assisting microextraction. Topics covered include ultrasound-assisted emulsification microextraction, ultrasound-assisted-emulsification-dispersive liquid-liquid microextraction, and ultrasound-assisted hollow-fiber liquid-phase microextraction with...
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Polymer based thick films - material quality and interface resistance evaluation
PublicationThe properties of polymer based thick film layers mede using different resistive pastes and dipping silvers have been studied. The composite of carbon and graphite (C/Gr) conducting particles suspended in different polymer vehicles were used for preparation resistive layers. Interface resistance Rc created between dipping silver (DiAg) contact layer and resistive layer was determined from the surface potential distribution measurements...
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Intensification of catechin extraction from the bark of Syzygium cumini using ultrasonication: Optimization, characterization, degradation analysis and kinetic studies
PublicationCatechin is a prominent polyphenolic component that possesses various medicinal properties. Present work communicates the intensification and optimization of catechin extraction from the bark of Syzygium cumini tree using stirred reactor, soxhlet, ultrasonic bath, and ultrasonic horn technique. The optimization of several parameters such as type of solvent, solid to solvent ratio (1:100 w/v), speed of agitation (300 RPM), extraction...
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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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Ultrasound monitoring for evaluation of damage in reinforced concrete
PublicationThe paper deals with automated monitoring of damage evolution in concrete elements subjected to three-point bending tests. The monitoring is based on the nonlinear interactions of traveling ultrasonic waves with micro-crack zones inside the concrete specimens and surface-breaking cracks. The developed procedure assumes semi-continuous ultrasonic testing during the element full loading cycle and generation of the power spectral...
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Fluorescence of p-hydroxyazobenzocrowns – Tautomeric equilibrium effect
PublicationThe spectroscopic properties of a series of para-hydroxyazobenzocrowns, including three novel compounds, were investigated using UV–Vis absorption and emission spectroscopy. This study presents, for the first time, determined quantum yield (QY) values for macrocycles of this category, ranging between 0.122 and 0.195. The highest values were obtained for crowns bearing two phenyl substituents in benzene rings. The impact of aromatic...
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UV-Vis-Induced Degradation of Phenol over Magnetic Photocatalysts Modified with Pt, Pd, Cu and Au Nanoparticles
PublicationThe combination of TiO2 photocatalyst and magnetic oxide nanoparticles enhances the separation and recoverable properties of nanosized TiO2 photocatalyst. Metal-modified (Me = Pd, Au, Pt, Cu) TiO2/SiO2@Fe3O4 nanocomposites were prepared by an ultrasonic-assisted sol-gel method. All prepared samples were characterized by X-ray powder diffraction (XRD) analysis, Brunauer-Emmett-Teller (BET) method, X-ray photoelectron spectroscopy...
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Interactions of fish gelatin and chitosan in uncrosslinked and crosslinked with EDC films: FT-IR study
PublicationFilms based on fish gelatin, chitosan and blend of fish gelatin and chitosan before and after cross-linking with EDC have been characterized by FT-IR spectroscopy. The FT-IR spectrum of fish gelatin film showed the characteristic amide I, amide II and amide III bands, and the FT-IR spectrum of chitosan film confirmed that the polymer was only a partially deacetylated product, and included CH3-C=O and NH2 groups, the latter both...
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Effect of ectoine on hydration spheres of peptides–spectroscopic studies
PublicationIn this paper, we use FTIR spectroscopy to characterize the hydration water of ectoine, its interactions with two peptides–diglycine and NAGMA, and the properties of water molecules in the hydration spheres of both peptides changed by the presence of the osmolyte. We found that the interaction of ectoine with the peptide hydration shells had no effect on its own hydration sphere. However, the enhanced hydration layer of the osmolyte...
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Resonance in Rectangular Microstrip Structure Loaded with a Pseudochiral Medium Layer
PublicationA rectangular microstrip structure with multilayer substrate containing dielectric and pseudochiral medium layers is studied in this paper. The effect of Omega medium layer location in the substrate and its thickness on the complex resonant frequency of the rectangular microstrip structure is investigated.
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The influence of intermolecular correlations on the infrared spectrum of liquid dimethyl sulfoxide
PublicationDimethyl sulfoxide (DMSO) is routinely applied as an excellent, water-miscible solvent and chemical reagent. Some of the most important data concerning its liquid structure were obtained using infrared (IR) spectroscopy. However, the actual extent of intermolecular correlations that connect the isolated monomer spectrum to the IR response of the bulk liquid is poorly studied thus far. Using ab initio molecular dynamics (AIMD) simulations,...
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Discrete element method modelling of elastic wave propagation in a meso-scale model of concrete
PublicationThis paper deals with the accurate modelling of ultrasonic wave propagation in concrete at the mesoscopic level. This was achieved through the development of a discrete element method (DEM) model capable of simulating elastic wave signals comparable to those measured experimentally. The main objective of the work was to propose a novel methodology for constructing a meso-scale model of concrete dedicated to the analysis of elastic...
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Prediction of the Mechanical Properties of P91 Steel by Means of Magneto-acoustic Emission and Acoustic Birefringence
PublicationThe paper describes an application of nondestructive volumetric magnetic and ultrasonic techniques for evaluation of the selected mechanical parameter variations of P91 steel having direct influence on its suitability for further use in critical components used in power plants. Two different types of deformation processes were carried out. First, a series of the P91 steel specimens was subjected to creep and second, one to plastic...
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Chemometric determination of solute-affected solvent vibrational spectra as a superior way of information extraction on solute solvation phenomena
PublicationW pracy zaprezentowano dwie chemometryczne metody wyznaczania widm zaburzonych rozpuszczalnika oraz liczby cząsteczek zaburzonych, na podstawie zmierzonych serii wibracyjnych widm FT-IR roztworów substancji. Pierwsza z metod została stworzona na podstawie Namiarowej Analizy Faktorowej (ang. Target Factor Analysis). Druga z nich wykorzystuje algorytm izolacji widm czystych składników z serii widm mieszanin. Działanie obu metod zostało...
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FT-IR studies of molecular interactions in formamide-methanol mixtures
PublicationTechniką ATR zmierzono widma FT-IR roztworów metanolu(MeOH) i formamidu(FA) w całym zakresie ich składu. Przeprowadzono analizę faktorową widm, która wykazała obecność dwóch kompleksów molekularnych matanolu z formamidem. Na podstawie profilów stężeniowych indywiduów absorbujących wyznaczono średni skład kompleksów w zależności od składu mieszaniny. Przeprowadzono również analizę pasma CO formamidu metodą widm różnicowych. Wyniki...
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Application of polyethylene glycol-coated iron oxide nanoparticles for magnetic solid phase extraction of copper from seawater samples and its determination by graphite furnace atomic absorption spectrometry using response surface methodology for optimization of extraction
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Stabilization of N-, N,N-, N,N'-Methylated and Unsubstituted Simple Amidine Salts by Multifurcated Hydrogen Bonds
PublicationIn the light of the usefulness of amidines in medicinal chem., this paper considers the effects on biol. properties and chem. reactivities of org. mols. affected by intramol. interactions. The study of chem. shifts has been an important source of information on the electronic structure of amidine salts and their ability to form non-covalent bonds with nucleic acids. The NMR and IR results demonstrate that hydrogen bonds are...
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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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Polyurethane Nanocomposites Containing Reduced Graphene Oxide, FTIR, Raman, and XRD Studies
PublicationRecently, graphene and other graphene-based materials have become an essential part of composite science and technology. Their unique properties are not only restricted to graphene but also shared with derivative compounds like graphene oxide, reduced graphene oxide, functionalized graphene, and so forth. One of the most structurally important materials, graphene oxide (GO), is prepared by the oxidation of graphite. Though removal...
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Total cross section for low-energy electron scattering from formic acid, (HCOOH), molecules
PublicationTotal cross section (TCS) for low-energy electron scattering from formic acid molecules has been measured using electrostatic electron spectrometer working in linear transmission mode. Two local maxima centered around 1.7 eV and 7.8 eV have been observed and associated with resonant scattering processes.
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Nanotechnologies in Development of Structural Materials and Biomaterials
PublicationThe nanometric materials and technologies resulted in nanostructures are reviewed. The examples of nanomaterials are shown. The typical nanotechnologies, including plastic deformation, mechanical attrition, controlled detonation, hot plasma jet synthesis, laser vaporisation, CVD and PVD, mechanical milling, annealing, ultrasonic irradiation, nanolithography, electrocrystallisation, electrospinning, sol-gel method, cryogenic laser-enhanced...
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Comparison of active proximity radars for the wearable devices
PublicationTwo methods of object position and movement estimation in relation to the user of smart glasses were investigated. An active infrared and ultrasonic methods of the obstacle detection were presented and compared. Application of these methods depend on active transducers type (physical medium used), geometry and surface properties of detected objects and their movement direction and speed. In the article properties of both detectors...
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Substrate Integrated Waveguide-Based Frequency-Tunable Self-Octaplexing Antenna
PublicationThis communication presents the first-ever substrate integrated waveguide (SIW)-based frequency-tunable self-octaplexing antenna (SOA) for wireless communication. The structure is arranged by implementing eight distinct patches with planar 50-ohm feedlines at the top of the SIW cavity, which realize eight distinct resonant frequencies. Independent tuning of each resonant frequency is achieved by incorporating appropriately allocated...
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Multi-transformer primary-side regulated flyback converter for supplying isolated IGBT and MOSFET drivers
PublicationThis paper presents primary-side voltage regulated multi-transformer quasi-resonant flyback converter (MTFC) for supplying isolated power switch drivers. The proposed topology offers distinct advantages over frequently used flyback converter possessing one high frequency transformer with isolated multiple outputs. Particularly, when a large number of separate dc supply units is required, then MTFC enables improved regular distribution...
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GUIDED WAVES IN SHIP STRUCTURAL HEALTH MONITORING – A FEASIBILITY STUDY
PublicationShips and offshore structures operate in a severe corrosion degradation environment and face difficulty in providing long- lasting corrosion protection. The Classification Societies recommend regular thickness measurements leading to structural component replacements, to ensure structural integrity during service life. The measurements are usually performed using ultrasonic thickness gauges and such an approach requires multiple...
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A CMRC-based compact rat-race coupler with harmonic suppression
PublicationIn this paper, an eective miniaturization technique exploiting compact microstrip resonant cells has been discussed and experimentally validated on the basis of a 3-dB microstrip rat-race coupler. The application of the method proposed has resulted in 91 % circuit area reduction in comparison to a conventional rat-race coupler. Experimental results show good agreement with theoretical characteristics, as well as an additional eect,...
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SiC-based phase-shift dual half bridge DC-DC converter as a key component of multilevel cascaded MV converters
PublicationThe paper describes SiC-based dual half bridge (DHB) DC-DC converter considered as a key component of high frequency isolated multilevel cascaded medium voltage converters. Two topologies of bi-directional DC-DC converters: the resonant half-bridge DC-DC converter and the phase-shift DHB converter are compared in the paper. Experimental results of SiC-based 50 kHz DHB DC-DC converter are presented in the paper.
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Cavitation Erosion of P110 Steel in Different Drilling Muds
PublicationThe P110 steel specimens were subjected to ultrasonic cavitation erosion in different compositions of drilling muds and surfactant additive. The test procedure was based on ASTM-G-32 standard recommendations. API 5CT-P110 steel is used for pipes in oil and gas industry. The harsh environment and high velocity of flows poses corrosive and erosive threat on materials used there. The composition of drilling fluid influences its rheological...
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INFLUENCE OF NANOPARTICLE CONCENTRATION ON THERMAL PROPERTIES OF THERMAL OIL-MWCNT NANOFLUID
PublicationThis paper deals with measurements of dynamic viscosity, thermal conductivity, electrical conductivity and pH of thermal oil-MWCNT (TO-MWCNT) nanofluid. Nanoparticles were tested at the concentration of 0.001%, 0.005%, 0.01%, 0.05%, and 0,1% by weight. Ultrasonic vibration was used in order to stabilize the dispersion of the nanoparticles. Thermal oil (TO) was selected as a base liquid, because of possible application in ORC systems...
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An Innovative Antenna Array with High Inter Element Isolation for Sub-6 GHz 5G MIMO Communication Systems
PublicationA novel technique is shown to improve the isolation between radiators in antenna arrays. The proposed technique suppresses the surface-wave propagation and reduces substrate loss thereby enhancing the overall performance of the array. This is achieved without affecting the antenna’s footprint. The proposed approach is demonstrated on a four-element array for 5G MIMO applications. Each radiating element in the array is constituted...
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Search for the most useful geometry of an acoustic journal bearing
PublicationComputer simulations of a number of journal bearing’s geometries utilising acoustic levitation were carried out. The choice of the best geometry depended on the ability of a deformed shape, created by piezo-electric elements, to facilitate squeeze film ultrasonic levitation, and also to create three evenly distributed diverging aerodynamic gaps. Deformations of analysed variants of the bearing’s shape were generated by numerical...
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The Experimental Determination of Bearings Dynamic Coefficients in a Wide Range of Rotational Speeds, Taking into Account the Resonance and Hydrodynamic Instability
PublicationMethods for the experimental determination of dynamic coefficients are commonly used for the analysis of various types of bearings, including hydrodynamic, aerodynamic and foil bearings. There are currently several algorithms that allow estimating bearing dynamic coefficients. Such algorithms usually use various excitation techniques applied to rotor–bearings systems. So far only a small number of scientific publications show how...
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Die Sandgrube „Köplitz“ – ein interessanter geologischer Aufschluss am Nordwestrand der Schmiedeberger Stauchendmoräne
PublicationDie Kiessandgrube Köplitz ermöglicht einen Einblick in die komplizierten, durch glazidynamische Überprägung gekennzeichneten geologischen Lagerungsverhältnisse im Bereich der Schmiedeberger Stauchendmoräne. Anhand neuer Geländedokumentationen wird ein kleiner Eindruck vom komplizierten injektiven „Fließfalten-Schuppenbau“ der Stauchendmoräne vermittelt. Die steil aufgerichteten, aus tertiären (Untermiozän bis Oligozän) und quartären...
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Badania eksperymentalne rezonansowego przetwornika piezoelektrycznego typu "unimorph"
PublicationW artykule opisano badania eksperymentalne piezoelektrycznego rezonansowego przetwornika zastosowanego do pomiaru właściwości mechanicznych tkanek miękkich. Po krótkim wstępie w kolejnych punktach przedstawiono opis stanowiska pomiarowego oraz metody pomiaru odkształceń prototypów, przesunięć częstotliwości rezonansowej, impedancji elektromechanicznej i parametrów schematów zastępczych. W dalszej...
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Electron Density from Balmer Series Hydrogen Lines and Ionization Temperatures in Inductively Coupled Argon Plasma Supplied by Aerosol and Volatile Species
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Nonradiative excitation energy transport and its analysis in concentrated systems
PublicationW pracy przedstawiono analizę transportu energii w roztworach dwuskładnikowych. Porównano wyniki pomiarów z modelem hoppingowym i diagramatycznym oraz z wynikami symulacji Monte Carlo. Stwierdzono dobrą zgodność wyników eksperymentalnych z przewidywaniami teorii i symulacjami komputerowymi.
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Space-mapping-based design flow of miniaturized broadband matching transformer with perforated metallization
PublicationA fast design procedure of unconventional passive components has been presented and experimentally validated on the basis of a wideband microstrip four-section matching transformer (50:6 OHm). A classic impedance matching circuit has been miniaturized by means of compact microstrip resonant cells (CMRCs) leading to a considerable length reduction (34%) together with minor degradation in its performance. The spacemapping-based design...
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Research on assessment of bolted joint state using elastic wave propagation
PublicationThe work contains results of experimental investigation of elastic wave propagation in a bolted single-lap joint. Tests were carried out for the excitation perpendicular to the connection plane. In experimental studies, PZT transducers were used for both excitation and registration of ultrasonic waves. The analyses took into account varying contact conditions between the elements of the connection depending on the value of the...
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Development and Assessment of Regeneration Methods for Peptide-Based QCM Biosensors in VOCs Analysis Applications
PublicationCleaning a quartz crystal microbalance (QCM) plays a crucial role in the regeneration of its biosensors for reuse. Imprecise removal of a receptor layer from a transducer’s surface can lead to unsteady operation during measurements. This article compares three approaches to regeneration of the piezoelectric transducers using the electrochemical, oxygen plasma and Piranha solution methods. Optimization of the cleaning method allowed...
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A GPU Solver for Sparse Generalized Eigenvalue Problems with Symmetric Complex-Valued Matrices Obtained Using Higher-Order FEM
PublicationThe paper discusses a fast implementation of the stabilized locally optimal block preconditioned conjugate gradient (sLOBPCG) method, using a hierarchical multilevel preconditioner to solve nonHermitian sparse generalized eigenvalue problems with large symmetric complex-valued matrices obtained using the higher-order finite-element method (FEM), applied to the analysis of a microwave resonator. The resonant frequencies of the low-order...
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Designing a High-sensitivity Microscale Triple-band Biosensor based on Terahertz MTMs to provide a perfect absorber for Non-Melanoma Skin Cancer diagnostic
PublicationNon-melanoma skin cancer (NMSC) is among the most prevalent forms of cancer originating in the top layer of the skin, with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) being its primary categories. While both types are highly treatable, the success of treatment hinges on early diagnosis. Early-stage NMSC detection can be achieved through clinical examination, typically involving visual inspection. An alternative,...
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Cavitation based cleaner technologies for biodiesel production and processing of hydrocarbon streams: A perspective on key fundamentals, missing process data and economic feasibility – A review
PublicationThe present review emphasizes the role of hydrodynamic cavitation (HC) and acoustic cavitation in clean and green technologies for selected fuels (of hydrocarbon origins such as gasoline, naphtha, diesel, heavy oil, and crude oil) processing applications including biodiesel production. Herein, the role of cavitation reactors, their geometrical parameters, physicochemical properties of liquid media, liquid oxidants, catalyst loading,...