Wyniki wyszukiwania dla: CROSS-SPECTRAL DENSITY FUNCTION
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Network oscillations modulate interictal epileptiform spike rate during human memory
PublikacjaEleven patients being evaluated with intracranial electroencephalography for medically resistant temporal lobe epilepsy participated in a visual recognition memory task. Interictal epileptiform spikes were manually marked and their rate of occurrence compared between baseline and three 2 s periods spanning a 6 s viewing period. During successful, but not unsuccessful, encoding of the images there was a significant reduction in...
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Structural, optical and electrochemical performance of black phosphorus and black arsenic-phosphorus nanostructures
PublikacjaBlack phosphorus (BP)-based nanostructures have drawn a lot of attention due to their tunable bandgap and extraordinary properties such as: high surface-to-volume ratio, large number of active sites, and prominent edges. However, low dimensional structures of black phosphorus oxidize easily, which hamper their application on a broader scale. One way to overcome these difficulties is to modify the black phosphorus structure by substituting...
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Myrosinase activity in different plant samples; optimisation of measurement conditions for spectrophotometric and pH-stat methods
PublikacjaMyrosinase found in Brassicaceae plants, is the enzyme responsible for hydrolysis of glucosinolates. As a result a variety of biologically active metabolites are liberated, whose importance in crop protection and especially in cancer chemoprevention is rapidly gaining recognition. The growing practical application of glucosinolate degradation products requires that sensitive and reliable methods of myrosinase activity determination...
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Cadmium complex possessing simultaneously silanethiolato- and dithiocarbamato-ligands. A novel single-source precursor of cadmium sulfide
PublikacjaThermal decomposition of suitable coordination compounds may be used as efficient route for fabrication of semiconducting layers. A new potential CdS precursor—a cadmium complex with all-sulfur Cd-coordination sphere [Cd{l-SSi(OBut)3}(S2CNC4H8)]2 (1) —has been prepared and its properties are investigated. The complex was obtained in the reaction between dimeric bis(tri-tert-butoxysilanethiolato) cadmium(II) [Cd{SSi(OBut)3}2]2 and...
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Noise in biological Raman spectroscopy
PublikacjaRaman spectroscopy is a widely used method to investigate chemical molecules by analyzing their vibrational transitions. It utilizes inelastic scattering of the laser light irradiating the investigated object. The scattered light requires appropriate filtering to reduce dominant laser light and expose much weaker components having shifted wavelengths of a characteristic spectral pattern. These components are measured by dispersing...
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Low-Coherence Interferometric Fiber-Optic Sensors with Potential Applications as Biosensors
PublikacjaFiber-optic Fabry-Pérot interferometers (FPI) can be applied as optical sensors, and excellent measurement sensitivity can be obtained by fine-tuning the interferometer design. In this work, we evaluate the ability of selected dielectric thin films to optimize the reflectivity of the Fabry-Pérot cavity. The spectral reflectance and transmittance of dielectric films made of titanium dioxide (TiO2) and aluminum oxide (Al2O3) with...
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Two-spinors, oscillator algebras, and qubits: aspects of manifestly covariant approach to relativistic quantum information
PublikacjaThe first part of the paper reviews applications of 2-spinor methods to relativistic qubits (analogies between tetrads in Minkowski space and 2-qubit states, qubits defined by means of null directions and their role for elimination of the Peres-Scudo-Terno phenomenon, advantages and disadvantages of relativistic polarization operators defined by the Pauli-Lubanski vector, manifestly covariant approach to unitary representations...
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PREDICTION OF SHIP MOTIONS IN IRREGULAR WAVES BASED ON RESPONSE AMPLITUDE OPERATORS EVALUATED EXPERIMENTALLY IN NOISE WAVES
PublikacjaThe most common methods for predicting ship roll motions in a specified sea state are direct measurements of motions in a representative irregular wave realisation (time domain) or calculations of motions from response amplitude operators (RAOs) in the frequency domain. The result of the first method is valid only for the tested sea state, whilst the second method is more flexible but less accurate. RAO-based predictions are calculated...
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Light box for investigation of characteristics of optoelectronics detectors
PublikacjaIn this paper, a light box for investigation of characteristics of optoelectronic detectors is described. The light box consists of an illumination device, an optical power sensor and a mechanical enclosure. The illumination device is based on four types of high-power light emitting diodes (LED): white light, red, green and blue. The illumination level can be varied for each LED independently by the driver and is measured by optical...
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A three-dimensional periodic beam for vibroacoustic isolation purposes
PublikacjaThis paper presents results of investigations on a three-dimensional (3-D) isotropic periodic beam. The beam can represent a vibroacoustic isolator of optimised dynamic characteristics in the case of its longitudinal, flexural and torsional behaviour. The optimisation process concerned both the widths as well as the positions of particular frequency band gaps that are present in the frequency spectrum of the beam. Since the dynamic...
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Low-Coherence Interferometric Fiber-Optic Sensors with Potential Applications as Biosensors
PublikacjaFiber-optic Fabry-Pérot interferometers (FPI) can be applied as optical sensors, and excellent measurement sensitivity can be obtained by fine-tuning the interferometer design. In this work, we evaluate the ability of selected dielectric thin films to optimize the reflectivity of the Fabry-Pérot cavity. The spectral reflectance and transmittance of dielectric films made of titanium dioxide (TiO2) and aluminum oxide (Al2O3) with...
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Universal autonomous control and management system for multipurpose unmanned surface vessel
PublikacjaThe paper presents design, structure and architecture of the Universal Autonomous Control and Management System (UACAMS) for multipurpose unmanned surface vessel. The system was designed, installed and implemented on the multipurpose platform - unmanned surface vessel named HydroDron. The platform is designed to execute hydrographic survey missions with multi-variant configuration of the survey system (payload? ) including multi-beam...
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A Robust Random Forest Model for Classifying the Severity of Partial Discharges in Dielectrics
PublikacjaPartial Discharges (PDs) are a common source of degradation in electrical assets. It is essential that the extent of the deterioration level of insulating medium is correctly identified, to optimize maintenance schedules and prevent abrupt power outages. Temporal PD signals received from damaged insulation, collected through the IEC-60270 method is the gold standard for PD detection. Temporal signals may be transformed to the frequency...
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Effect of applied standard wood machining fluid on colour and chemical composition of the machined wood surface
PublikacjaAppropriate monitoring of wood machining processes is a key issue to ensure the expected quality of the processed wood, expected efficiency and minimize energy consumption of production processes. A new trend is the design of environmentally friendly machining fluids. In this paper, as a preliminary study in this field, the effect of applied standard wood machining fluid on changes in the colour and chemical composition of the...
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Reduced-Cost Microwave Modeling Using Constrained Domains and Dimensionality Reduction
PublikacjaDevelopment of modern microwave devices largely exploits full-wave electromagnetic (EM) simulations. Yet, simulation-driven design may be problematic due to the incurred CPU expenses. Addressing the high-cost issues stimulated the development of surrogate modeling methods. Among them, data-driven techniques seem to be the most widespread owing to their flexibility and accessibility. Nonetheless, applicability of approximation-based...
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Linear viscoelastic transversely isotropic model based on the spectral decomposition of elasticity tensors
PublikacjaThe linear viscoelasticity is still a useful model in the engineering for studying the behavior of materials loaded with different loading rates (frequencies). Certain types of materials reveal also an anisotropic behavior: fiber reinforced composites, asphalt concrete mixtures, or wood, to name a few. In general, researchers try to identify experimentally the dependence of engineering constants like: directional Young’s moduli...
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Crystal and electronic structures of Ni(II) silanethiolates containing flexible diamine ligands
PublikacjaFive nickel(II) complexes containing aliphatic diamines and tri-tert-butoxysilanethiolate ligand have been synthesized for the purpose of studying their structural, spectral (IR, UV–Vis, HF EPR) and thermal properties. Complexes (1)–(5) have been prepared in high yield by reactions of [Ni{SSi(OtBu)3}2(NH3)(H2O)] with 1.3-propanediamine (L1), 1,6-hexanediamine (L2), or 1,7-heptanediamine (L3). The X-ray structures were determined...
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Spectral Finite Element Method in Condition Monitoring and Damage Detection
PublikacjaIt is well known that the dynamic behaviour of engineering structures may carry very important and crucial information that can be further used for the assessment of their condition as well as detection of any damage induced. The current interest in monitoring techniques based on the propagation of guided elastic waves requires that numerical techniques used for modelling the phenomena associated must shift into the realm of high...
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Propagation of Ship-Generated Noise in Shallow Sea
PublikacjaContamination of sea environment by noise and any energy radiated to water constitutes today a problem to which more and more attention is paid, in view, a.o., of consequences of an impact of these factors onto marine fauna. European Union has introduced a directive by which EU countries are made responsible to undertake efforts aimed at reaching a good envirenmental status of European seas by 2020. A main source of underwater...
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Noise Analysis of Continuous GPS Time Series of Selected EPN Stations to Investigate Variations in Stability of Monument Types
PublikacjaThe type of monument that a GPS antenna is placed on plays a significant role in noise estimation for each permanent GPS station. In this research 18 Polish permanent GPS stations that belong to the EPN (EUREF Permanent Network) were analyzed using Maximum Likelihood Estimation (MLE). The antennae of Polish EPN stations are placed on roofs of buildings or on concrete pillars. The analyzed data covers a period of 5 years from 2008...
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Neutral Dissociation of Pyridine Evoked by Irradiation of Ionized Atomic and Molecular Hydrogen Beams
PublikacjaThe interactions of ions with molecules and the determination of their dissociation patterns are challenging endeavors of fundamental importance for theoretical and experimental science. In particular, the investigations on bond-breaking and new bond-forming processes triggered by the ionic impact may shed light on the stellar wind interaction with interstellar media, ionic beam irradiations of the living cells, ion-track nanotechnology,...
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Audio content analysis in the urban area telemonitoring system
PublikacjaArtykuł przedstawia możliwości rozwinięcie monitoringu miejskiego o automatyczną analizę dźwięku. Przedstawiono metody parametryzacji dźwięku, które możliwe są do zastosowania w takim systemie oraz omówiono aspekty techniczne implementacji. W kolejnej części przedstawiono system decyzyjny oparty na drzewach zastosowany w systemie. System ten rozpoznaje dźwięki niebezpieczne (strzał, rozbita szyba, krzyk) wśród dźwięków zarejestrowanych...
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Fluorescence studies by quenching and protein unfolding on the interaction of bioactive compounds in water extracts of kiwi fruit cultivars with human serum albumin
PublikacjaThe main aim of this investigation was to characterize new kiwi fruit cultivars after cold storage treatment and to determine the similarities and differences between them, using spectroscopic methods. The chemometric comparison of kiwi fruit cultivars based on physicochemical indices during cold storage was carried out. All kiwi fruit cultivars showed a high level of correlation between the contents of phenolic compounds (polyphenols,...
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In situ spectroelectrochemical and theoretical study on the oxidation of a 4H-imidazole-ruthenium dye adsorbed on nanocrystalline TiO2thin film electrodes
PublikacjaTerpyridine 4H-imidazole-ruthenium(ii) complexes are considered promising candidates for use as sensitizers in dye sensitized solar cells (DSSCs) by displaying broad absorption in the visible range, where the dominant absorption features are due to metal-to-ligand charge transfer (MLCT) transitions. The ruthenium(iii) intermediates resulting from photoinduced MLCT transitions are essential intermediates in the photoredox-cycle...
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Molecular level interpretation of excess infrared spectroscopy
PublikacjaInfrared (IR) spectroscopy is an invaluable tool in studying intermolecular interactions in solvent mixtures. The deviation of the IR spectrum of a mixture from the spectra of its pure components is a sensitive measure of the non-ideality of solutions and the modulation of intermolecular interactions introduced by mutual influence of the components. Excess IR spectroscopy, based on the established notion of excess thermodynamic...
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Low-cost multi-criterial design optimization of compact microwave passives using constrained surrogates and dimensionality reduction
PublikacjaDesign of contemporary microwave circuits is a challenging task. Typically, it has to take into account several performance requirements and constraints. The design objectives are often conflicting and their simultaneous improvement may not be possible; instead, compromise solutions are to be sought. Representative examples are miniaturized microwave passives where reduction of the circuit size has a detrimental effect on its electrical...
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Preliminary results from HEDGEHOG REXUS Project - sounding rocket experiment on accelerations, vibrations and heat flow
PublikacjaAs access to space conditions becomes more available, both technically and economically, scientists' interest in launching finer and more sophisticated experiments grows. This applies now more than ever to fragile by nature biological and chemical experiments. To be qualified for launch, such experiments need to be carefully tested prior to the event. The tests should represent actual launch conditions as closely and in as detailed...
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Synthesis, physicochemical and theoretical studies on new rhodium and ruthenium dimers. Relationship between structure and cytotoxic activity
PublikacjaTwo dimeric compounds of the general formulae (Et3NH)2[Rh2(μ2-L)4Cl2] (1) (where L = thiophene-2-carboxylate) and [((η6-p-cymene)Ru)2(μ-Cl)3]PF6 (2) have been synthesized using a new method. The unique anionic complex 1 (space group P bca) has octahedral coordination in which the equatorial positions are occupied by the oxygen atoms of four thiophene-2-carboxylates in a paddle wheel fashion. In complex 2 (space group ), each Ru(II)...
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Comparison of GPS tropospheric delays derived from two consecutive EPN reprocessing campaigns from the point of view of climate monitoring
PublikacjaThe main purpose of this research was to acquire information about consistency of ZTD (zenith total delay) linear trends and seasonal components between two consecutive GPS reprocessing campaigns. The analysis concerned two sets of the ZTD time series which were estimated during EUREF (Reference Frame Sub-Commission for Europe) EPN (Permanent Network) reprocessing campaigns according to 2008 and 2015 MUT AC (Military University...
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A Systematic Review for Establishing Relevant Environmental Parameters for Urban Lighting: Translating Research into Practice
PublikacjaThe application of lighting technologies developed in the 20th century has increased the brightness and changed the spectral composition of nocturnal night-time habitats and night skies across urban, peri-urban, rural, and pristine landscapes, and subsequently, researchers have observed the disturbance of biological rhythms of flora and fauna. To reduce these impacts, it is essential to translate relevant knowledge about the potential...
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The Rayleigh model of the multipath fading channel
Dane BadawczeThe dataset contains the results of simulations that are part of the research on modelling the multipath fading in the communication channel. The Rayleigh fading envelope is generated using the Monte-Carlo simulation (MCS) in the LabVIEW programming environment.
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Multiplicative Long Short-Term Memory with Improved Mayfly Optimization for LULC Classification
PublikacjaLand Use and Land Cover (LULC) monitoring is crucial for global transformation, sustainable land control, urban planning, urban growth prediction, and the establishment of climate regulations for long-term development. Remote sensing images have become increasingly important in many environmental planning and land use surveys in recent times. LULC is evaluated in this research using the Sat 4, Sat 6, and Eurosat datasets. Various...
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Recent Advances in Accelerated Multi-Objective Design of High-Frequency Structures using Knowledge-Based Constrained Modeling Approach
PublikacjaDesign automation, including reliable optimization of engineering systems, is of paramount importance for both academia and industry. This includes the design of high-frequency structures (antennas, microwave circuits, integrated photonic components), where the appropriate adjustment of geometry and material parameters is crucial to meet stringent performance requirements dictated by practical applications. Realistic design has...
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Investigation of noises in the EPN weekly time series
PublikacjaThe constantly growing needs of permanent stati ons’ velocities users cause their stability level to increase. To this research we included more than 150 stations located across Europe operating within the EUREF Permanent Network (EPN) w ith weekly changes in the ITRF2005 reference frame. The obvious long-range dependencies in the stochastic part of GPS time series were p roven by Ljung-Box...
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Dimensionality-Reduced Antenna Modeling with Stochastically Established Constrained Domain
PublikacjaOver the recent years, surrogate modeling methods have become increasingly widespread in the design of contemporary antenna systems. On the one hand, it is associated with a growing awareness of numerical optimization, instrumental in achieving high-performance structures. On the other hand, considerable computational expenses incurred by massive full-wave electromagnetic (EM) analyses, routinely employed as a major design tool,...
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Supramolecular junctions of the PDA tetramers
Dane BadawczeIn this dataset, a set of polydopamine (PDA) supramolecular junctions with linear and cyclic tetramers in different oxidation states (indolequinone , IQ or dihydroxyindole, DHI) in the scattering region are investigated. Electronic structure of the supramolecular junction with cyclic and linear PDA tetramers, including Electron density maps for the...
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The Weibull model of the multipath fading channel
Dane BadawczeThe dataset contains the results of simulations that are part of the research on modelling the multipath fading in the communication channel. The Weibull fading envelope is generated using the Monte-Carlo simulation (MCS) in the LabVIEW programming environment.
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Controlled grafting of vinylic monomers on polyolefins: a robust mathematical modeling approach
PublikacjaExperimental and mathematical modeling analyses were used for controlling melt free-radical grafting of vinylic monomers on polyolefins and, thereby, reducing the disturbance of undesired cross-linking of polyolefins. Response surface, desirability function, and artificial intelligence methodologies were blended to modeling/optimization of grafting reaction in terms of vinylic monomer content, peroxide initiator concentration,...
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THE VIBRATION BASED DIAGNOSTICS OF SHIP PROPULSION SYSTEMS
PublikacjaThe article has been worked out on the basis of the report devoted to the conducted diagnostic investigations of the ship main propulsion unit’s mechanical system. Gdansk University of Technology has been ordered with such investigations by the repair Shipyard carrying out the ship’s overhaul. Diagnostic tests involved measurements and analyses of the vibration signals generated in selected constructional kinematic pairs of the...
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Structural, magnetic and spectral properties of tetrahedral cobalt(II) silanethiolates: a variety of structures and manifestation of field-induced slow magnetic relaxation
PublikacjaBlue crystals of five heteroleptic cobalt(II) silanethiolates 1–5 have been obtained by the reaction of [Co{SSi (tBuO)3}2(NH3)]2 with aminopyridines and aminomethylpyridines at an appropriate molar ratio and their structural, spectral, thermal and magnetic properties have been established and described. All complexes 1–5 contain Co(II) ions in a tetrahedral CoN2S2 environment formed by (tBuO)3SiS− residues and pyridines and present...
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Investigation of long-range dependencies in the stochastic part of daily GPS solutions
PublikacjaThe long-range dependence (LRD) of the stochastic part of GPS-derived topocentric coordinates change (North, East, Up) results with relatively high autocorrelation values with a focus on self-similarity. One of the reasons for such self-similarity in the GPS time series are noises that are commonly recognised to prevail in the form of the flicker noise model. To prove the self-similarity of the stochastic part of GPS time series...
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Development of fragility curves in adjacent steel moment-resisting frames considering pounding effects through improved wavelet-based refined damage-sensitive feature
PublikacjaFragility curves present useful information related to earthquake-induced probability assessment of steel moment-resisting frames (MRFs) and determine the probability of the damage exceedance at different floor levels of MRFs. The review of the literature shows that most of the previous studies dealing with the fragility curves were based on conventional measures, such as spectral acceleration at the first mode period, peak...
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Integrated Experimental and Theoretical Approach for Efficient Design and Synthesis of Gold-Based Double Halide Perovskites
PublikacjaApplied cutting-edge electronic structure and phonon simulations provide a reliable knowledge about the stability of perovskite structures and their electronic properties, which are crucial for design of effective nanomaterials. Gold is one of the exceptional elements, which can exist both as a monovalent and a trivalent ion in the B site of a double perovskite such as A2BI BIIIX6. However, until now, electronic properties of Cs2AuI AuIIIX6...
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Density smoothness estimation problem using a wavelet approach
PublikacjaIn this paper we consider a smoothness parameter estimation problem for a density function. The smoothness parameter of a function is defined in terms of Besov spaces. This paper is an extension of recent results (K. Dziedziul, M. Kucharska, B. Wolnik, Estimation of the smoothness parameter ). The construction of the estimator is based on wavelets coefficients. Although we believe that the effective estimation of the smoothness...
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The α-µ model of the multipath fading channel
Dane BadawczeThe dataset contains the results of simulations that are part of the research on modelling the multipath fading in the communication channel. The envelope of the α-µ fading process is generated using the Monte-Carlo simulation (MCS) in the LabVIEW programming environment.
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Spectroscopic studies on physicochemical properties of selected unsymmetrical bisacridine derivatives and NMR analysis of their interactions with the model sequence Pu22 aided by molecular dynamics
PublikacjaIn recent years, new promising acridine derivatives have appeared, belonging to the unsymmetrical bisacridines (UAs) family with high anticancer activity. Both their physicochemical properties and their mechanism of action at the molecular level have not been thoroughly analyzed so far. Four derivatives were selected for the study, termed as: C-2028, C-2041, C-2045 and C-2053. The first aim of this work was to determine the protonation...
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Investigations of the Methods of Time Delay Measurement of Stochastic Signals Using Cross-correlation with the Hilbert Transform
PublikacjaThe article presents the results of simulation studies of four methods of estimating time delay for random signals using cross-correlation with the Hilbert Transform. Selected models of mutually delayed stochastic signals were used in the simulations, corresponding to the signals obtained from scintillation detectors in radioisotope measurements of liquid-gas two-phase flow. Standard deviations of the values of the individual functions...
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Structural and physico-mechanical properties of natural rubber/GTR composites devulcanized by microwaves: Influence of GTR source and irradiation time
PublikacjaGround tire rubber from car and truck was modified using microwave irradiation at variable time. The irradiated ground tire rubber was used as filler in composites based on natural rubber. The composites, with high content of ground tire rubber, were prepared using an internal batch mixer and subsequently cross-linked at 160℃. The influence of the ground tire rubber source (car/truck) and irradiation time on structure, physico-mechanical...
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Wojciech Sadowski prof. dr hab. inż.
OsobyWojciech Sadowski (ur. 2.02.1954 r. w Ostaszewie), naukowiec, polski inżynier, profesor Politechniki Gdańskiej, specjalista z fizyki ciała stałego, nanotechnologii, optoelektroniki. Studia wyższe ukończył w 1979 r. w Leningradzkim Instytucie Elektrotechnicznym w Leningradzie w specjalności dielektryki i półprzewodniki, uzyskując tytuł zawodowy magistra inżyniera elektronika. Od 1979 r. pracuje na Politechnice Gdańskiej, pełniąc...
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The differential impact of a density of Polish pine wood on cutting forces with its origin region taken into consideration
PublikacjaIn the article the dependence of cutting forces in a function the density of wood with regard to the wood origin are presented. Samples used in experiment were with Scotch pine (Pinus sylvestris L.) originating from four provenances in Poland (Figure 1). Wood density was measured by two methods: stereometric method (global density) and radiometric method (local density). Stereometric method consists in measurements the volume...