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Search results for: VISCOELASTIC PHASE SEPARATION
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Research on the separation properties of empty-column gas chromatography (EC-GC) and conditions for simulated distillation (SIMDIS)
PublicationThe paper presents the results of investigations on new procedures of determination of selected cleaning additives in diesel fuel. Two procedures: one-step analysis using gas chromatography with flame ionization detection (GC-FID) or mass spectrometry (GC-MS) and a two-step procedure in which normal-phase high-performance liquid chromatography (NP-HPLC) was used for preliminary separation of the additives, were compared. The additive...
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Multi-DBD plasma actuator for flow separation control around NACA 0012 and NACA 0015 airfoil models
PublicationIn this paper application of innovative multi-DBD plasma actuator for flow separation control is presented. The influence of the airflowgenerated by this actuator on the flow around NACA 0012 and NACA 0015 airfoil models was investigated. The results obtained from 2D PIVmeasurements showed that the multi-DBD actuator with floating interelectrode can be attractive for leading and trailing edge separation control.
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Accuracy and parameter estimation of elastic and viscoelastic models of water hammer
PublicationW artykule analizowany jest zagadnienie uderzenia hydraulicznego, stanowiące jeden z najważniejszych problemów nieustalonego przepływu w przewodach pod ciśnieniem. Mimo ponad stuletnich doświadczeń w badaniach zagadnienie to jest ciągle nie w pełni rozpoznane. Może być onio rozpatrywane na dwóch płaszczyznach - praktycznej i teoretycznej. W obu przypadkach na etapie rozwiązania powstają problemy sprawiające, że wyniki nie są satysfakcjonujące....
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Finite element description of nonlinear viscoelastic behaviour of technical fabric
PublicationW pracy podano propozycję nieliniowego modelowania zachowania się tkaniny technicznej. Podano wyniki identyfikacji i zweryfikowano poprzez numeryczną symulację prób laboratoryjnych
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Non-linear viscoelastic modelling of earthquake-induced structural pounding
PublicationCelem artykułu jest analiza nieliniowego lepko-sprężystego modelu siły zderzenia, który ma zastosowanie do symulacji zderzeń pomiędzy konstrukcjami budowlanymi podczas trzęsień ziemi. Efektywność modelu sprawdzono poprzez porównanie wyników symulacji numerycznych z wynikami eksperymentalnymi. Wyniki pracy pokazują, iż w stosunku do innych modeli zderzeń, nieliniowy model lepko-sprężysty umożliwia najdokładniejszą symulację siły...
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Viscoelastic lubrication on spherical slide bearing in impulsive unsteady motion.
PublicationNiniejsza praca przedstawia numeryczne i semi-analityczne wyznaczanie składowych wektora prędkości lepkosprężystego oleju, oraz wartości ciśnienia hydrodynamicznego i sił nośnych w sferycznym łożysku ślizgowym o zmieniającej się w czasie niesymetrycznej szczelinie smarnej podczas nieustalonego impulsywnego smarowania. Łożyska ślizgowe o czopach kulistych występują w maszynach transportowych w celu lepszego manewrowania ustawieniem...
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Ongoing progress on novel nanocomposite membranes for the separation of heavy metals from contaminated water
PublicationMembranes, as the primary separation element of membrane-based processes, have greatly attracted the attention of researchers in several water treatment applications, including wastewater treatment, water purification, water disinfection, toxic and non-toxic chemical molecules, heavy metals, among others. Today, the removal of heavy metals from water has become challenging, in which chemical engineers are approaching new materials...
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Asynchronous phase-location system
PublicationThis paper presents concept and implementation of digital phase-location system, designed as a navigational aid for marine applications. The main feature of the proposed system is the ability to work in both synchronous mode, with one master station and set of slave stations synchronised with master, and in asynchronous mode with independent clocking of all stations.
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Computed aided system for separation and classification of the abnormal erythrocytes in human blood
PublicationThe human peripheral blood consists of cells (red cells, white cells, and platelets) suspended in plasma. In the following research the team assessed an influence of nanodiamond particles on blood elements over various periods of time. The material used in the study consisted of samples taken from ten healthy humans of various age, different blood types and both sexes. The markings were leaded by adding to the blood unmodified...
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Integrated Three-Level Dual-Phase Inverter
PublicationIn view of reducing the number of inverter legs that provide dual-phase, three-level output voltages (as may be needed in an uninterruptible power supply), and that also provide a wide range of output frequencies (as needed in an advanced motor drive system with wide speed ranges), a three-level, dual-phase inverter topology is presented in this paper. Its three-level attribute was based on the F-type inverter topological concept,...
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Trailing-Edge Separation Control of a NACA 0015 Airfoil Using Dielectric-Barrier-Discharge Plasma Actuators
PublicationThis paper presents a part of the works conducted in the Plasmaero European project (task 3.1), where the trailing-edge flow separation of a NACA 0015 airfoil has been controlled using four different dielectric barrier discharge (DBD) actuator types at three institutions across Europe. The results show that it is possible to enhance the aerodynamic performance of aircraft at speeds up to 40 m/s. Dielectric-barrier-discharge vortex...
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FLUID PHASE EQUILIBRIA
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Effective Gap Size Index for Determination of Optimum Separation Distance Preventing Pounding between Buildings during Earthquakes
PublicationSeismic excitations may lead to collisions between adjacent civil engineering structures causing major damage. In this paper, an effective equation for calculating the gap size index is proposed so as to provide the optimum separation distance preventing structural pounding during different earthquakes. Evaluation of the best prediction of the required separation distance between two adjacent buildings was carried out by using...
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Automatic evaluation of sound separation quality
PublicationW publikacji tej opisano problem oceny efektywności algorytmów separacji dźwięków muzycznych. Standardowa procedure służąca do takiej oceny nie istnieje. Najbardziej uzasadnionym podejściem wydają się być odsłuchowe testy subiektywne. Niemniej, aby taka ocena była wartościowa, niezbędna jest porządna walidacja statystyczna wyników, co oznacza iż grupa ekspertów powinna być duża oraz właściwości akustyczne pomieszczenia. Ponadto...
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Application of chiral chromatography for enantiomeric separation of currently used pesticides from various chemical groups
PublicationChiral pesticides account for more than 25 % of currently used pesticides and this ratio is still increasing. According to the number of chiral centers in the structure, a pesticide may consist of two or multiple enantiomers or stereoisomers. Studies into the stereoselective behaviour of pesticides started in the early 1990s and most research efforts focused on understanding the environmental fate and effects of these pesticides....
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Verification of Formulas for Periods of Adjacent Buildings Used to Assess Minimum Separation Gap Preventing Structural Pounding during Earthquakes
PublicationInsufficient separation distance between adjacent buildings may lead to serious damages during earthquakes due to structural pounding. The best way to prevent collisions is to provide sufficiently large separation distance between the structures. In this paper, the periods of two closely-spaced linear and nonlinear buildings have been investigated so as to accurately assess the minimum in-between separation gap. A new equation...
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Miniaturized solid-phase extraction techniques
PublicationMore than 80% of analysis time is spent on sample collection and sample preparation, so sample preparation is a critical part of the analytical process. Traditionally, liquid-liquid extraction was developed and employed to screen for general unknowns. However, solid-phase extraction (SPE) is becoming highly popular as an alternative, due to its simplicity and economy in terms of time and solvent. This review summarizes the current...
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New Polymeric Materials for Solid Phase Extraction
PublicationSolid phase extraction (SPE) is a popular sample preparation technique, which can be applied directly in gas–solid phase and liquid–solid phase, or indirectly to solid samples by using, e.g., thermodesorption with subsequent chromatographic analysis. Although SPE can be described as a physical extraction process involving a liquid phase and a solid phase, the increased use of packed sorbent formats seems to have led to a bias toward...
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A new concept of measuring the friction forces for cartilage and polymers with viscoelastic properties
PublicationReferat przedstawia nową koncepcję dotyczącą pomiaru niskich sił tarcia oraz właściwości materiałów lepkosprężystych. Zaprezentowano: ogólny zarys metody pomiaru, wskazania dotyczące projektowania i budowy urządzenia pomiarowego, model matematyczny oraz sposób identyfikacji parametrów modelu. Metoda ta jest szczególnie przydatna w przypadku analizy właściwości materiałowej polimerów oraz tkanki chrząstki stawowej człowieka, zarówno...
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Pounding of structures during earthquakes modelled by nonlinear viscoelastic impact element.
PublicationAnalizowano zderzenia konstrukcji budowlanych podczas trzęsień ziemi wykorzystując model lepkosprężysty siły zderzenia. W analizie, zachowanie konstrukcji o różnych własnościach dynamicznych symulowane jest modelem dyskretnym o skupionych masach. wyniki badań pokazują, iż zderzenie może prowadzić do znacznego wzrostu odpowiedzi konstrukcji mniej sztywnej i lżejszej.
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Numerical contribution to the viscoelastic magnetic lubrication of human joint in periodic motion.
PublicationPraca przedstawia rozwiązania problemu smarowania stawów człowieka w układzie współrzędnych ortogonalnych krzywoliniowych dla ruchu nieustalonego okresowego w polu magnetycznym. Uwzględnia się lepkosprężyste właściwości cieczy synowialnej w trakcie smarowania
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THE PHASE SHIFTERS INFLUENCE ON THE POWER SYSTEM STABILITY
PublicationThe paper presents the effect of phase shifters as FACTS devices on the possibility of improving the angle stability. Presented results obtained by the dynamic simulation performed on the mathematical model of the three machine system cooperating with the 400 kV network. The generative blocks models include turbine models with their controllers and models of synchronous generators with their excitation systems and voltage regulation....
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Influence of Ionic Liquid Structure on Supported Ionic Liquid Membranes Effectiveness in Carbon Dioxide/Methane Separation
PublicationThis paper indicates the possibility of application of imidazolium ionic liquids immobilized in polymeric supports—supported ionic liquid membranes—in CO2 separation from gaseous streams (e.g., biogas). Imidazolium salts containing alkyl fluoride anions, bis(trifluoromethylsulfonyl)imide and trifluoromethanesulfonate, selectively separating CO2 were used. The permeability of CO2 through membranes was investigated under gas pressure...
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Critical behaviour of the smectic A*–C* phase transition and electroclinic effect of ferroelectric liquid crystals with terphenyl rigid core
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Phase transition of a dimorphic fungus Penicillium marneffei
PublicationPenicillium marneffei is a pathogenic fungus that afflicts immunocompromised individuals who live or travel in Southeast Asia. This species is unique, because it is the only dimorphic member of the genus Penicillium. Dimorphism results from a process, termed phase transition, which is regulated by temperature of incubation. At room temperature, the fungus grows filamentously (mould phase), but at body temperature (37°C), a uninucleate...
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Automated Design of Linear Phase Filters
PublicationThis paper presents a fast technique for an automated design of microwave filters with linear phase. The proposed method exploits the cost function defined using the location of complex zeros and poles of the filter’s transfer and reflection function. The effectiveness of the proposed technique is presented with two illustrative examples.
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On phase equilibrium of an elastic liquid shell with wedge disclination
PublicationBased on the six-parameter shell theory we consider the phase equilibrium of a two-phase liquid membrane containing a wedge disclination. The considered problems are related to modelling of phase transitions in biological or lipid membranes. In order to capture the membrane behaviour we consider a special case of elastic shells which energy is invariant under major transformations of a reference configuration and can be treated...
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Liquid–phase microextraction: A review of reviews
PublicationSample preparation is an important step in chemical analysis. It is generally done to deal with problems associated with the nature of the matrix, low analyte concentrations in real samples or analyte features incompatible with the instrumentation. Classical methods of extraction consume large volumes of hazardous solvents and other reagents and are not in line with the recent emergence of green analytical chemistry. Liquid-phase...
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Stability and phase transition investigation of olanzapine polymorphs
PublicationWe use electrical embedded-fragment QM method with both DFT/ωB97XD/6-31G* and MP2/6-31G* to investigate the phase transformations of olanzapine. Gibbs free energy calculations predict that form I is always the most stable structure and form II is the least stable one, while form IV is more stable than form III below about 200 K but less stable above this temperature, implying a polymorphic phase transformation. This may account...
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Evaluation of the stiffness modulus and phase angle of cold in-place recycled mix-tures for long curing periods
PublicationArticle presents the changes inbehaviour of cold-in place recycling mixtures made using cement and bituminous emulsion (CIR mixtures) after anelongated time of curing. Most of the available literatureregarding change instiffness modulus and phase angle presents resultsfor a maximum of several dozen days,which makesit difficult to predict the behaviour over the whole life of the compacted layer. The article...
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Phase-difference positioning in asynchronous system
PublicationThis paper presents concept and implementation of digital positioning system based on phase difference measurements, designed as a navigational aid for marine applications. Main feature of proposed system is the ability to work in both synchronous mode, with one master station and set of slave stations synchronized with master, and in asynchronous mode with independent clocking of all stations.
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Musical Instrument Separation Applied to Music Genre Classification . Separacja instrumentów muzycznych w zastosowaniu do rozpoznawania gatunków muzycznych
PublicationThis paper outlines first issues related to music genre classification and a short description of algorithms used for musical instrument separation. Also, the paper presents proposed optimization of the feature vectors used for music genre recognition. Then, the ability of decision algorithms to properly recognize music genres is discussed based on two databases. In addition, results are cited for another database with regard to...
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Miniaturized solid phase microextratcion
PublicationWithout any doubt analytical laboratories have an essential role in environmental protection due to the fact that they takes an active part in the monitoring pollutants present in air, water or soil. From the other side, the analytical activity is involved in the generation of toxic waste what is associated with the use of not eco-friendly reagents and solvents. For these reasons, green analytical chemistry (GAC) was introduced...
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Polymeric metal‐containing ionic liquid sorbent coating for the determination of amines using headspace solid‐phase microextraction
PublicationThis study describes the design, synthesis, and application of polymeric ionic liquid sorbent coatings featuring nickel metal centers for the determination of volatile and semivolatile amines from water samples using headspace solidphase microextraction. The examined polymeric ionic liquid sorbent coatings were composed of two ionic liquid monomers (tetra(3-vinylimidazolium)nickel bis[(trifluoromethyl)sulfonyl]imide [Ni2+(VIM)4]...
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Superconductivity in the Nb-Ru-Ge σ phase
PublicationWe show that the previously unreported ternary σ-phase material Nb20.4Ru5.7Ge3.9 (Nb0.68Ru0.19Ge0.13) is a superconductor with a critical temperature of 2.2 K. Temperature-dependent magnetic susceptibility, resistance, and specific-heat measurements were used to characterize the superconducting transition. The Sommerfeld constant γ for Nb20.4Ru5.7Ge3.9 is 91 mJ mol f.u. −1K−2 (∼3 mJ mol atom−1 K−2) and the specific-heat anomaly at...
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Effect of Laminar Pulsatile Fluid Flow on Separation of Volatile Organic Compounds from Aqueous Solution by a Hollow Fiber Membrane-Based Process
PublicationIn this study, a laminar pulsatile fluid flow was used for the separation of benzene, toluene, ethylbenzene, and xylene isomers (BTEX) from aqueous solutions. Polyether sulfone hollow fiber membrane has been applied to this process. The effects of BTEX concentration, and feed and extraction flow rates were examined. It was found that the application of the pulsatile fluid flow with...
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A Fast Method of Separation of the Noisy Background from the Head-Cross Section in the Sequence of MRI Scans
PublicationThe paper presents a new method of removing the noisy background from the sequence of magnetic resonance imaging (MRl) scans. The sequence of scans is required in order to monitor a passage of a contrast agent through the brain tissue. The scans contain the noisy head-cross data and also the noisy background data. The latter has to be removed and excluded from a further analysis. It is achieved by applying some basic morphological...
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Phase Transition in a Sequence-Structure Channel
PublicationWe study an interesting channel which maps binary sequences to self-avoiding walks in the two-dimensional grid, inspired by a model of protein folding from statistical physics. The channel is characterized by a Boltzmann/Gibbs distribution with a free parameter corresponding to temperature. We estimate the conditional entropy between the input sequence and the output fold, giving an upper bound which exhibits an unusual phase transition...
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Damped forced vibration analysis of single-walled carbon nanotubes resting on viscoelastic foundation in thermal environment using nonlocal strain gradient theory
PublicationIn this paper, the damped forced vibration of single-walled carbon nanotubes (SWCNTs) is analyzed using a new shear deformation beam theory. The SWCNTs are modeled as a flexible beam on the viscoelastic foundation embedded in the thermal environment and subjected to a transverse dynamic load. The equilibrium equations are formulated by the new shear deformation beam theory which is accompanied with higher-order nonlocal strain...
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Separation of saline oily wastewater by membrane distillation
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The influence of frequency separation on imaging properties in DFEIT
PublicationW artykule przedstawiono wpływ wyboru składowych częstotliwościowych dla różnicowej tomografii impedancyjnej na wynik i własności obrazowania w dwuczęstotliwościowej różnicowej tomografii impedancyjnej.A Dual Frequency EIT is an extension of a traditional EIT that uses two sinusoidal signals for imaging. Appropriate selection of signals' frequency allows to achieve reasonable contrast of imaged structure. It has already been shown...
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Evaluation of the separation algorithm performance employing ANNs
PublicationCelem niniejszego rozdziału jest przedstawienie metodyki separacji dźwięków muzycznych bez informacji a priori o dźwiękach zawartych w muzycznym miksie. W pracy pokazano, że prawidłowo wytrenowana sztuczna sieć neuronowa (SNN)jest w stanie w sposób automatyczny poprawnie sklasyfikować dźwięki zawarte w zmiksowanym sygnale. Skuteczność klasyfikacji SNN jest porównywalna z oceną subiektywną ekspertów.
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Application of ionic liquids for gas separation processes
PublicationNowym kierunkiem w procesach separacji dwutlenku węgla stało się w ostatnich latach zastosowanie cieczy jonowych. Niemierzalna prężność par i możliwość dostosowania ich właściwości czyni je idealnymi mediami zastępującymi lotne, korozyjne i toksyczne rozpuszczalniki. Ponadto ciecze jonowe wykazują niską współabsorpcję innych gazów. Dlatego też, możliwe jest selektywne odseparowanie dwutlenku węgla z mieszanin gazowych
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Evolutionary sets of safe ship trajectories with speed reduction manoeuvres within traffic separation schemes
PublicationIn the previous paper the author presented the evolutionary ship trajectory planning method designed to support Traffic Separation Schemes (TSS). This time the extensions of this method are described which allow to combine evolutionary trajectory planning with speed reduction manoeuvres. On TSS regions with higher than usual density of traffic and smaller distances between ships, the course alterations alone are not always sufficient...
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Computational Fluid Dynamics Simulation of Gas–Liquid Multiphase Flow in T-junction for CO2 Separation
PublicationThe article presents the results of a computational fluid dynamics (CFD) analysis of gas-liquid multiphase flow. The simulation was conducted using CFD code and the Euler–Euler approach. The presented study relates to the non–reactive, steady-state, turbulent flow of water and carbon dioxide mixture in a 3D pipe. Separation phenomenon between phases is observed. The solution was obtained using a mixture model. Different values...
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CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY
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Calcification Alters the Viscoelastic Properties of Tendon Fascicle Bundles Depending on Matrix Content
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Theoretical and experimental assessment of parameters for the non-linear viscoelastic model of structural pounding
PublicationZjawisko zderzeń pomiędzy sąsiednimi konstrukcjami budowlanymi podczas trzęsień ziemi jest w ostatnim czasie intensywnie badane z wykorzystaniem różnych modeli numerycznych siły zderzenia w czasie kontaktu. Wyniki badań eksperymentalnych pokazują, iż nieliniowy model lepko-sprężysty jest najdokładniejszy wśród modeli stosowanych do analizy. Model ten zdefiniowany jest poprzez dwa parametry: liczbę tłumienia zderzenia oraz parametr...
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Classification of Music Genres Based on Music Separation into Harmonic and Drum Components . Klasyfikacja gatunków muzycznych wykorzystująca separację instrumentów muzycznych
PublicationThis article presents a study on music genre classification based on music separation into harmonic and drum components. For this purpose, audio signal separation is executed to extend the overall vector of parameters by new descriptors extracted from harmonic and/or drum music content. The study is performed using the ISMIS database of music files represented by vectors of parameters containing music features. The Support Vector...
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MgPdSb─An Electron-Deficient Half-Heusler Phase
PublicationThe half-Heusler family consists of many semiconducting intermetallic compounds, virtually all of them having a valence electron count (VEC) of 18. We have studied an electron-deficient (VEC = 17) phase MgPdSb and its Pd-stuffed variant MgPd1.25Sb. The cubic F4̅3m crystal structure was confirmed by the Rietveld refinement of powder X-ray diffraction (XRD) data. The lattice parameter is a = 6.284 and 6.335 Å for MgPdSb and MgPd1.25Sb,...