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Search results for: gram-charlier series
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Mechanical characterization of a gravel column in a calibration chamber operating as a triaxial cell
PublicationA series of tests considering the behavior of gravel columns was performed. A segment of column with a height of 1 m and a diameter of 0.53 m was modelled in a calibration chamber used as a triaxial cell at three different lateral stress applied. The vertical load transferred on the column head was simulated with steady increase of water pressures in the upper and lower membranes. During the loading the volumetric changes in the...
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Accuracy analysis of the RSSI BLE SensorTag signal for indoor localization purposes
PublicationIn this paper we describe possibility of use the RSSI signal (Radio Signal Strength Indication) from Texas Instruments SensorTag CC2650 for indoor positioning purposes. This idea is not a new but in our opinion it is possible to use SensorTags with Bluetooth LE wireless interface for positioning inside buildings in such applications as people findings in hospitals, senior come care, etc. RSSI is mostly selected as the sensor localization...
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TS-based RSM-aided design of cold-formed steel stiffened C-sectional columns susceptible to buckling
PublicationThe paper focuses on joint-performance analysis of a built-up cold-formed thin-walled C-sectional column with a fillister (stiffener) of the same type, interconnected with a series of bolts located along the length of the compressed members in specific spacing. The quantity of bolts and the non-connected starting distance of the fillister are considered random variables of the problem. Optimal distribution of joints on the stiffener...
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Annihilation rates of low-energy positron scattering from simple diatomic molecules
PublicationWe discuss the calculations of Zeff coefficients for a series of diatomic molecules over the range of energies below the positronium formation. During the development of a general code for polyatomic, nonlinear molecules colliding with positrons, it was discovered that the earlier one, employed only for diatomic molecules, had an error. The error is corrected and the corrected results are presented here. We also discuss a way of...
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Towards Audio Signal Equalization Based on Spectral Characteristics of a Listening Room and Music Content Reproduced
PublicationThis study presents investigations of the influence of the room acoustics on the frequency characteristic of the audio signal playback. First, the concept of a novel spectral equalization method of the room acoustic conditions is introduced. On the basis of the room spectral response, a system for room acoustics compensation based on an equalizer designed is proposed. The system settings depend on music genre recognized automatically....
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Positron binding to alkali-metal hydrides: The role of molecular vibrations
PublicationThe bound vibrational levels for J=0 have been computed for the series of alkali-metal hydride molecules from LiH to RbH, including NaH and KH. For all four molecules the corresponding potential-energy curves have been obtained for each isolated species and for its positron-bound complex (e+XH). It is found that the calculated positron affinity values strongly depend on the molecular vibrational state for which they are obtained...
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A robust 18-pulse diode rectifier with coupled reactors
PublicationThe article presents the principle of operation and selected results of simulation and laboratory tests of the 18-pulse rectifier system with coupled reactors and small series active power filter. The presented system makes it possible to reduce, especially in distribution supply networks, undesired higher current harmonics. The 18-pulse nature of operation of the rectifier is reached using a set of coupled three-phase network...
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Computational Complexity and Its Influence on Predictive Capabilities of Machine Learning Models for Concrete Mix Design
PublicationThe design of concrete mixtures is crucial in concrete technology, aiming to produce concrete that meets specific quality and performance criteria. Modern standards require not only strength but also eco-friendliness and production efficiency. Based on the Three Equation Method, conventional mix design methods involve analytical and laboratory procedures but are insufficient for contemporary concrete technology, leading to overengineering...
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Synthesis, structural characterization, and thermal properties of Ca‐ and La‐doped soda‐lime glasses by laser melting
PublicationLaser melting techniques have been used in the preparation of unconventional glass compositions with high melting temperatures. Thus, we wanted to test the feasibility of using a CO2 laser in the preparation of nitrogen-rich oxynitride glasses and nitride silicate glasses. Melting from oxides and metallic raw materials, we wanted to study first glass formation and possible evaporation losses of the glass components. Two glass series...
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Reactions of cobalt(ii) chloride and cobalt(ii) acetate with hemisalen-type ligands: ligand transformation, oxidation of cobalt and complex formation. Preliminary study on the cytotoxicity of Co(ii) and Co(iii) hemisalen complexes
PublicationSeveral molecular cobalt(II) complexes, one Co(II) coordination polymer, and one ionic cobalt(III) complex with imine hemisalen ligands were synthesized. The hemisalen ligands were synthesized from o-vanillin (oVP) and diverse aminopyridines (compounds HL1–HL4) or aminophenol (compound HL5). It was observed that cobalt(II) chloride in dry acetonitrile catalyzes a transformation of HL1 and HL3 instead of complex formation. The conversion...
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Comparative Analysis of Metabolic Variations, Antioxidant Profiles and Antimicrobial Activity of Salvia hispanica (Chia) Seed, Sprout, Leaf, Flower, Root and Herb Extracts
PublicationThe purpose of this study was to evaluate the phytochemical profiles of the seeds, sprouts, leaves, flowers, roots and herb of Salvia hispanica and to demonstrate their significant contribution to antioxidant and antimicrobial activities. Applied methods were: HPLC-DAD coupled with post-column derivatization with ABTS reagent, untargeted metabolomics performed by LC-Q-Orbitrap HRMS, and two-fold micro-dilution broth method, which...
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Application of gaze tracking technology to quality of experience domain
PublicationA new methodological approach to study subjective assessment results employing gaze tracking technology is shown. Notions of Human-Computer Interaction (HCI) and Quality of Experience (QoE) are shortly introduced in the context of their common application. Then, the gaze tracking system developed at the Multimedia Systems Department (MSD) of Gdansk University of Technology (GUT) is presented. A series of audio-visual subjective...
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Application of auto calibration and linearization algorithms to improve sound quality of computer devices
PublicationAn application of auto calibration and linearization algorithms designed for correcting acoustic characteristics of selected computer devices was presented in the paper. The functionality of the algorithms were presented for two kind of computer devices: ultrabook class computer and portable device of All-In-One type. The algorithms were adjusted for the given type of the device on the basis of series of measurements conducted...
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Efficiency of Wastewater Treatment in Single-Family Constructed Wetlands in Kaszuby Lake District
PublicationIn the paper results of investigation upon three different configurations of single family treatment wetlands were presented. It was indicated that the application of treatment wetlands for single family effluent is a effective and sustainable solution for wastewater treatment in the rural areas. In spite of the receiving higher concentration of pollutants in comparison to the TWs operated in Europe and USA analysed TWs ensure...
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Enhancing capabilities of Atomic Force Microscopy by tip motion harmonics analysis
PublicationMotion of a tip used in an atomic force microscope can be described by the Lennard-Jones potential, approximated by the van der Waals force in a long-range interaction. Here we present a general framework of approximation of the tip motion by adding three terms of Taylor series what results in non-zero harmonics in an output signal. We have worked out a measurement system which allows recording of an excitation tip signal and its...
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Optical Spectroscopic Studies of Tetrahydrofuran Fragmentation Induced by Collisions with Dihydrogen Cations
PublicationCollisions of dihydrogen cations with tetrahydrofuran molecules have been studied. Luminescence spectra and the emission functions of the excited products at projectile energies ranging from 8 to 1000 eV have been measured using collision-induced emission spectroscopy. The recorded spectra are dominated by the atomic lines of the hydrogen Balmer series, whose intensities decrease more quickly than derived by the quantum-theoretical...
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Music signal equalization in a changing environment
PublicationThe paper presents the concept of an automatic system for music signal correction, considering room frequency response and music genre being played. The proposed algorithm, based on the room frequency response, compensates acoustic conditions surrounding the sound source. Additionally, the compensation process considers the signal content by recognizing music genre. As part of the described research, a series of subjective tests...
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KTaO3-based nanocomposites for air treatment
PublicationA series of single semiconductors and their nanocomposites combination (such as KTaO3 + CdSe + SrTiO3; KTaO3 + CdS +WO3; KTaO3 + CdS + MoS2) were prepared using hydrothermal route. Photocatalytic activity of as-prepared nanocomposites was estimated by photocatalytic degradation of toluene in the gas phase using light-emitting diodes (LEDs, 375 nm) in four subsequent cycles. The nanocomposites were characterized by scanning electron...
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Magnetic and capacitive couplings influence on power losses in double circuit high voltage overhead transmission line
PublicationPurpose – The paper aims to discuss problems of power and energy losses in a double-circuit overhead transmission line. It was observed from energymeters’ readings, that in such a line, active power losses can be measured as “negative”. The “negative” active power losses appear when the active power injected to the circuit is lower than the active power received at the circuit end. The purpose of this paper is to explain this phenomenon. Theoretical...
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Nitrogen-doped diamond thin films: potential application in Fabry-Pérot interferometer
PublicationIn this paper we present results of preliminary research of using nitrogen-doped diamond (NDD) films as reflective layer in Fabry-Pérot interferometer. NDD films were deposited on Si substrates by Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) with the use of CH4, H2 and N2 gas mixtures. During deposition process methane flow rate varied while nitrogen flow was constant. We performed series of measurements which showed...
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R&D of satellite pumps and motors with small geometrical displacement supplied with oil and non-flammable liquids
PublicationThe newest construction of satellite motors and self-suction satellite pumps with small geometrical displacement have been described in this article. The characteristics of volumetric and total efficiency of one satellite motor, selected from the series, supplied with oil have been presented. These characteristics have been compared with the orbital motors' characteristics. The remaining specifications of these motors were also...
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Peculiarities of measurement uncertainty evaluation at calibrating a ring gauge
PublicationExample S13 from EA-4/02 M:2013 “Calibration of a ring gauge with a nominal diameter of 90 mm” is analyzed. The report uses the kurtosis method and the law of propagation of expanded uncertainty developed by the authors to the expanded uncertainty evaluation. It is shown that the introduction of a coaxiality correction for the ring gauge and the measuring axis of the comparator leads to the need to estimate its standard measurement...
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Performance of LSP preemption methods in different MPLS networks
PublicationPreemption in Multiprotocol Label Switching (MPLS) is an optional traffic engineering technique used to create a new path of high priority when there is not enough bandwidth available. In such case the path is admitted by removing one or more previously allocated paths of lower priority. As there are usually many possible sets of low priority paths which can be selected, a preemption algorithm is being started to select the best...
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Simple method for preparation of Dialkyl (2,3-dihydro-1,3-thiazol-2-yl)-phosphonates
PublicationAbstract A simple synthesis of dialkyl (2,3-dihydro-1,3-thiazol-2-yl)-phosphonates from thiazoliumsalts and trialkyl phosphites is described. The series of dialkyl (2,3-dihydro-1,3-thiazol-2-yl)-phosphonates with various substituents in positions 3, 4, and 5 of the thiazole ring wereprepared. However, only phosphonates with an aryl on the nitrogen atom were stable enoughfor chromatographic purification, although all the new phosphonates...
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Syntheses of N-Substituted Thymine Thioacetamides. A Novel Approach to Site Selective Acylation of Diaminoalkanes
PublicationA new series of N-substituted thiocarbamoyl derivs. contg. histamine, tryptamine, and other moieties having at least one amino group attached to an aliph. chain has been synthesized from (1-thyminyl)thioacetamide in good isolated yields (69-86%). N-[2-(4-Imidazolyl)ethyl](1-thyminyl)thioacetamide was hydrolyzed to its amide on prolonged heating in water. Ammonium sulfide (20-22% soln. in water) has found interesting new applications...
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Functional phase bistability in a nanocrystalline RbMn[Fe(CN)6] thin film fabricated by matrix-assisted laser evaporation
PublicationOne of the main barriers hindering applications of Prussian blue metal assemblies is their poor processability, which makes the fabrication of intact thin films very difficult. In this work, a nanocrystalline RbMn[Fe(CN)6]·xH2O film on silicon substrate was obtained for the first time via laser-stimulated deposition and investigated. Temperature-induced phase transition and bistability within broad hysteresis loop (120 K), along...
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The Influence of Cooperation on the Operation of an MPC Controller Pair in a Nuclear Power Plant Turbine Generator Set
PublicationThe paper discusses the problem of cooperation between multiple model predictive control (MPC) systems. This approach aims at improving the control quality in electrical energy generation and forms the next step in a series of publications by the authors focusing on the optimization and control of electric power systems. Cooperation and cooperative object concepts in relation to a multi MPC system are defined and a cooperative control...
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Evolution of Physical Properties of RE 3 Ni 5 Al 19 Family (RE = Y, Nd, Sm, Gd, Tb, Dy, Ho, and Er)
PublicationSingle crystals of RE3Ni5Al19 series (RE = Y, Nd, Sm, Gd, Tb, Dy, Ho, and Er) are grown using the Al self-flux method. The crystal structure is examined by both single crystal and powder X-ray diffraction. Physical properties are studied for the first time for RE3Ni5Al19 (RE = Y, Nd, Gd, Tb, Dy, Ho, and Er) by means of magnetic susceptibility, electrical resistivity, and heat capacity measurements. Complex magnetic behaviors, with...
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PHOTON LUMINESCENCE STUDIES OF TETRAHYDROFURAN FOLLOWING TRIHYDROGEN CATIONS IMPACT IN THE 20–1000 EV ENERGY RANGE
PublicationPhoton emission arising during tetrahydrofuran (C4H8O, THF) fragmentation initiated by H3 + ion impact has been studied experimentally. Luminescence fragmentation spectra and the relative emission cross-sections of the excited fragments have been measured using collision-induced emission spectroscopy in the 20–1000 eV energy range. The main features in the spectra are the H Balmer series lines, whose intensities decrease with increasing...
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Communication Platform for Evaluation of Transmitted Speech Quality
PublicationA voice communication system designed and implemented is described. The purpose of the presented platform was to enable a series of experiments related to the quality assessment of algorithms used in the coding and transmitting of speech. The system is equipped with tools for recording signals at each stage of processing, making it possible to subject them to subjective assessments by listening tests or, objective evaluation employing...
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An Analysis of Elliptical-Rectangular Multipatch Structure on Dielectric-Coated Confocal and Nonconfocal Elliptic Cylinders
PublicationA rigorous analysis of the resonance frequency problem of an elliptical-rectangular microstrip structure mounted on dielectric-coated elliptic conducting cylinder, with electrically small radius, is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. The analysis is carried out considering the expansion of the field as a series of Mathieu functions. The complex resonance frequencies of...
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Application of Web-GIS and Geovisual Analytics to Monitoring of Seabed Evolution in South Baltic Sea Coastal Areas
PublicationRegular surveys of coastal zone seabed deliver important information about geomorphologic processes such as silting of waterways. The recent introduction of the Sentinel series of sensors has allowed for the use of satellite sensing for shallow bathymetry morphology monitoring. In this context, this article presents a dedicated Geographic Information System for Baltic Sea shallow water depth monitoring on the basis of Sentinel-2...
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The dynamic performance analysis of the Micro-turbine's rotor supparted on slide and roling element bearings
PublicationThis article presents the results of investigations of dynamic characteristics of a small-dimension rotor with slide and rolling element bearings. The object of investigations was the rotor-bearing system designed for the ORC based low-power steam micro-turbine. The investigations were performed using MESWIR series programs, as well as commercial FEA software ABAQUS and MADYN 2000. The results of modal analysis of the micro-rotor...
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Representation of magnetic hysteresis in single-phase transformer for circuit simulations
PublicationThe paper presents a mathematical model for the hysteresis phenomenon in a multi-winding single-phase core type transformer. In the circuit transformer model, it is assumed that there is a flux common Φ to all windings as nonlinear and hysteretic function of the total currents Θ (Ampere turns) of all windings. To simulate magnetic behaviour of the iron core the feedback scalar Preisach model of hysteresis is developed. The Preisach...
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Multidimensional GIS for satellite imagery analysis
PublicationMultidimensional Geographical Information System allows storing, querying and processing of multidimensional query data. It is able to process satellite imagery and provide tools for its analysis. In the article authors present the developed system that analyzes a time series of SENTINEL - 1 mission satellite imagery acquired over the coast of Poland. The algorithm used finds and detects changes in the shape...
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Optimizing the computation of a parallel 3D finite difference algorithm for graphics processing units
PublicationThis paper explores the possibilities of using a graphics processing unit for complex 3D finite difference computation via MUSTA‐FORCE and WENO algorithms. We propose a novel algorithm based on the new properties of CUDA surface memory optimized for 2D spatial locality and compare it with 3D stencil computations carried out via shared memory, which is currently considered to be the best approach. A case study was performed for...
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Thermoplastic polyurethane/(organically modified montmorillonite) nanocomposites produced by in situ polymerization
PublicationA series of polyurethane nanocomposites were synthesized from thermoplastic polyurethanes (with different hard segment ratios) and two types of organically modified montmorillonites (OMMT) - Cloisite® 10A and Cloisite® 20A. The thermal behavior was examined by non-isothermal thermogravimetry (TG, DTG), Differential Scanning Calorimetry (DSC) and Dynamic-Mechanical Thermal Analysis (DMTA). The results of X-ray analyses showed that...
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Torsion of restrained thin-walled bars of open constant bisymmetric cross-section
PublicationElastic and geometric stiffness matrices were derived using Castigliano's first theorem, for the case of torsion of restrained thin-walled bars of open constant bisymmetric cross-section. Functions which describe the angles of torsion were adopted from the solutions of thedifferential equation for restrained torsion. The exact solutions were simplified by expanding them in a power series. Numerical examples were taken from Kujawa...
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Failure characterisation of sandwich beams using integrated acoustic emission and digital image correlation techniques
PublicationThe paper presents the experimental study of the failure behaviour of sandwich beams subjected to bending. The samples examined are sandwich beams made of polyethylene terephthalate foam core and glass fibre-reinforced polymer laminate face sheets. In a series of experiments, it has been proposed to integrate diagnostic techniques with acoustic emission and digital image correlation to accurately track the cracking process on the...
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Application of COSMO-RS-DARE as a Tool for Testing Consistency of Solubility Data: Case of Coumarin in Neat Alcohols
PublicationCoumarin is a naturally occurring lactone-type benzopyrone with various applications in the pharmaceutical, food, perfume, and cosmetics industries. This hydrophobic compound is poorly soluble in water but dissolves well in protic organic solvents such as alcohols. Despite the extensive use of coumarin, there are only a few reports documenting its solubility in organic solvents, and some reported data are incongruent, which...
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Sustainable energy consumption – Empirical evidence of a household in Poland
PublicationThere is an expected increase in the demand for electricity from households in European countries. The outcome of the growing proportion of renewable energy sources in the energy supply mix should result in improved customer awareness regarding their electricity usage. Additionally, they must assume a more proactive role in overseeing their electricity usage. Innovation and pollution management have become crucial catalysts for...
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Novel 2-(2-alkylthiobenzenesulfonyl)-3-(phenylprop-2-ynylideneamino)guanidine derivatives as potent anticancer agents – Synthesis, molecular structure, QSAR studies and metabolic stability
PublicationA series of new 2-(2-alkylthiobenzenesulfonyl)-3-(phenylprop-2-ynylideneamino)guanidine derivatives have been synthesized and evaluated in vitro by MTT assays for their antiproliferative activity against cell lines of colon cancer HCT-116, cervical cancer HeLa and breast cancer MCF-7. The obtained results indicated that these compounds display prominent cytotoxic effect. The best anticancer properties have been observed for derivatives...
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Surface texture generation during cylindrical milling in the aspect of cutting force variations
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Surface roughness analysis after machining of direct laser deposited tungsten carbide
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Laboratorial studies on the seepage impact in open-channel flow turbulence
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Kinematic the flaying frontal rising kick
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Artificial neural network model of hardness, porosity and cavitation erosion wear of APS deposited Al2O3 -13 wt% TiO2 coatings
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The crack surface morphology investigation of S355J2 steel after bending-torsion fatigue
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Status of the MPD Experiment at JINR
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Preliminary Studies on a Lightweight Porous Cement-Based Composite – Gel Concrete
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