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wszystkich: 493
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Wyniki wyszukiwania dla: VACUUM RABI OSCILLATIONS
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GPS-derived height changes in diurnal and sub-diurnal timescales
PublikacjaThis paper describes the research concerning precise short-time GPS solutions conducted in the Centre of Applied Geomatics, Military University of Technology, Warsaw, Poland. The data from ASG-EUPOS (Polish Active Geodetic Network) was processed using Bernese 5.0 software and EPN (EUREF Permanent Network) standards and models. In this study, the adapted 3-hour observation window is shifted every hour for obtaining hourly geocentric...
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Application of short-time GNSS solution geodynamical studies
PublikacjaThe paper presents the results of research related to the application of GNSS solutions in short observational periods in geodynamical investigations. Authors used the 3-hour solution appointed from hour-long interval of about 30 chosen stations on mountainous terrains from over 100 which were worked out. The main aim was to check the correctness of such solutions by the comparison with the daily ones. Some outliers in East component...
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Effective highly accurate time integrators for linear Klein-Gordon equations across the scales
PublikacjaWe propose an efficient approach for time integration of Klein-Gordon equations with highly oscillatory in time input terms. The new methods are highly accurate in the entire range, from slowly varying up to highly oscillatory regimes. Our approach is based on splitting methods tailored to the structure of the input term which allows us to resolve the oscillations in the system uniformly in all frequencies, while the error constant...
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Effective highly accurate time integrators for linear Klein-Gordon equations across the scales
PublikacjaWe propose an efficient approach for time integration of Klein-Gordon equations with highly oscillatory in time input terms. The new methods are highly accurate in the entire range, from slowly varying up to highly oscillatory regimes. Our approach is based on splitting methods tailored to the structure of the input term which allows us to resolve the oscillations in the system uniformly in all frequencies, while the error constant...
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Characteristics of volatile organic compounds emission profiles from hot road bitumens
PublikacjaA procedure for the investigation and comparison of volatile organic compounds (VOCs) emission profiles to the atmosphere from road bitumens with various degrees of oxidation is proposed. The procedure makes use of headspace analysis and gas chromatography with universal as well as selective detection, including gas chromatography–mass spectrometry (GC–MS). The studies revealed that so-called vacuum residue, which is the main component...
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THIRD-ORDER EXPONENTIAL INTEGRATOR FOR LINEAR KLEIN–GORDON EQUATIONS WITH TIME AND SPACE-DEPENDANT MASS
PublikacjaAllowing for space- and time-dependance of mass in Klein–Gordon equations re- solves the problem of negative probability density and of violation of Lorenz covariance of interaction in quantum mechanics. Moreover it extends their applicability to the domain of quantum cosmology, where the variation in mass may be accompanied by high oscillations....
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THIRD-ORDER EXPONENTIAL INTEGRATOR FOR LINEAR KLEIN–GORDON EQUATIONS WITH TIME AND SPACE-DEPENDANT MASS
PublikacjaAllowing for space- and time-dependance of mass in Klein–Gordon equations re- solves the problem of negative probability density and of violation of Lorenz covariance of interaction in quantum mechanics. Moreover it extends their applicability to the domain of quantum cosmology, where the variation in mass may be accompanied by high oscillations....
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Dysfunctional prefrontal cortical network activity and interactions following cannabinoid receptor activation.
PublikacjaCoordinated activity spanning anatomically distributed neuronal networks underpins cognition and mediates limbic-cortical interactions during learning, memory, and decision-making. We used CP55940, a potent agonist of brain cannabinoid receptors known to disrupt coordinated activity in hippocampus, to investigate the roles of network oscillations during hippocampal and medial prefrontal cortical (mPFC) interactions in rats. During...
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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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On degradation of glass/polyester laminate immersed in water
PublikacjaMechanical behaviour was compared for glass/ polyester laminates manufactured in the boatbuilding plant using three methods: hand lay-up, vacuum bagging, infusion. Specimens were tested in dry condition and following accelerated water immersion test (70°C- corresponding to the exposure of 30 years at 19°C). In three point bending test 40-50% reduction in laminate strength was observed due to water immersion. The highest degradation...
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STUDY ON THE EFFECTIVENESS OF THE TURBINE CONDENSER AIR EXTRACTION SYSTEM USING HYDRO EJECTORS
PublikacjaThe aim of the paper is to investigate the effectiveness of the 18K380 steam turbine condenser air extraction system using hydro ejectors. Motivation for the analysis is a need of improvement of the energy conversion ratio of the power plant. To achieve this goal it is necessary to establish efficiency of each subsystem of the energy cycle. The air extraction system is not a highly power consuming system but it has great impact...
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Dynamical description of quantum computing: generic nonlocality of quantumnoise
PublikacjaWe develop a dynamical non-Markovian description of quantum computing in the weak-coupling limit, in the lowest-order approximation. We show that the long-range memory of the quantum reservoir (such as the 1/t4 one exhibited by electromagnetic vacuum) produces a strong interrelation between the structure of noise and the quantum algorithm, implying nonlocal attacks of noise. This shows that the implicit assumption of quantum error...
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Influence of mesh density on 2D viscous flutter in a turbomachinery cascade
PublikacjaIn this study numerical simulations of 2D viscous flutter were performed and compared with available experimental results for various mesh densities and flow parameters. Calculations were carried out for the bending oscillations of an Eleventh Standard Configuration cascade. ANSYS CFX code was used for the SST, SA and k-ω turbulence model calculations.
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Automatic Regularization by Quantization in Reducible Representations of CCR: Point-Form Quantum Optics with Classical Sources
PublikacjaElectromagnetic fields are quantized in a manifestly covariant way by means ofa class of reducible "center-of-mass N-representations" of the algebra of canonical commutationrelations (CCR). The four-potential Aa(x) transforms in these representations as aHermitian four-vector field in Minkowski four-position space (without change of gauge), butin momentum space it splits into spin-1 massless photons and two massless scalars. Whatwe...
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Qualification of brazing procedure for furnace brazing of austenitic steel according to requirements of the ASME BPVC section IX
PublikacjaThe article presents the procedure for qualifying brazing technology in a vacuum furnace on the example of stainless steel elements joined with copper filler material from the F-No group. 105, in accordance with the ASME Sec. IX, part QB (ASME Boiler and Pressure Vessel Code. Qualification Standard for Welding, Brazing and Fusing; Procedures; Welders; Brazers; and Welding, Brazing and Fusing Operators). The essential variables...
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Multifunctional PID Neuro-Controller for Synchronous Generator
PublikacjaThis paper deals with a PID Neuro-Controller (PIDNC) for synchronous generator system. The controller is based on artificial neural network and adaptive control strategy. It ensures two functions: maintaining the generator voltage at its desired value and damping electromechanical oscillations. The performance of the proposed controller is evaluated on the basis of simulation tests. A comparative study of the results obtained with...
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Contribution to the mechanism of liquid membrane oscillators involving cationic surfactant.
PublikacjaIt is shown that liquid membrane oscillators with cationic surfactants havemore complex oscillation patterns than observed previously. The actual details of the oscillations depend strongly on the nature of the membrane material, dislosing even the presence of parallel molecular events. It appearsthat sampling topology also has a great influence on the observed oscillato-ry behaviour. Variation of oscillation patterns with...
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Badanie dynamiki platform pływających morskich turbin wiatrowych z zastosowaniem metod numerycznej mechaniki płynów
PublikacjaPraca dotyczy badania ruchu platform pływających pod morskie turbiny wiatrowe. Przedstawiono w niej główne metody obliczeń i przedyskutowano ich zastosowanie. Na przykładzie koncepcji konstrukcji 3-kolumnowej platformy typu Spar przedstawiono metodykę wykonywania obliczeń z zastosowaniem programu AQWA opartego na metodzie dyfrakcyjnej, rozszerzonego o współczynniki wynikające z lepkości wyznaczone za pomocą obliczeń RANSE-CFD....
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Influence of Annealing Atmospheres on Photoelectrochemical Activity of TiO2 Nanotubes Modified with AuCu Nanoparticles
PublikacjaIn this article, we studied the annealing process of AuCu layers deposited on TiO2 nanotubes (NTs) conducted in various atmospheres such as air, vacuum, argon, and hydrogen in order to obtain materials active in both visible and UV–vis ranges. The material fabrication route covers the electrochemical anodization of a Ti plate, followed by thin AuCu film magnetron sputtering and further thermal treatment. Scanning electron microscopy...
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Effect of Maximal Apnoea Easy-Going and Struggle Phases on Subarachnoid Width and Pial Artery Pulsation in Elite Breath-Hold Divers
PublikacjaPurpose: The aim of the study was to assess changes in subarachnoid space width (sas-TQ), the marker of intracranial pressure (ICP), pial artery pulsation (cc-TQ) and cardiac contribution to blood pressure (BP), cerebral blood flow velocity (CBFV) and cc-TQ oscillations throughout the maximal breath hold in elite apnoea divers. Non-invasive assessment of sas-TQ and cc-TQ became possible due to recently developed method based on...
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Intelligent turbogenerator controller based on artifical neural network
PublikacjaThe paper presents a desing of an intelligent controller based on neural network (ICNN). The ICNN ensures at the same time two fundamental functions : the maintaining of generator voltage at the desired value and the damping of the electromechanical oscillations. Its performance is evaluted on a single machine infinite bus power system through computer simulations. The dynamic and transient operation of the proposed controller...
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Monitoring of volatile organic compounds (VOCs) in atmospheric air. Part II. Sample collection and preparation
PublikacjaThe paper reviews literature information on air sampling techniques commonly used for monitoring volatile organic compounds (VOCs) levels in atmospheric air. It describes containers for collecting samples of atmospheric air, such as vacuum canisters and bags made from synthetic materials. It discusses dynamic, passive and denudational techniques for sampling analytes from air combining isolation with preliminary enrichment, and...
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Combined environmental testing device for picosatellites
PublikacjaAs access to space conditions becomes more available, both technically and economically, scientists’ interest in launching finer and more sophisticated experiments grows. 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 a detailed manner. Typical tests for payload include: vibration tests, thermal and vacuum tests,...
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The QDMC Model Predictive Controller for the Nuclear Power Plant Steam Turbine Control
PublikacjaThere are typically two main control loops with PI con trollers operating at each turbo-generator set. In this paper a model predictive controller QDMC for the steam turbine is proposed - instead of a typical PI controller. The QDMC controller utilize a step-response model for the controlled system. This model parameters are determined, based on the simplified and linear model of turbo-generator set, which parameters are identified...
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Application in circular sawing machines of the experimental results of investigations of the chip removing system operation
PublikacjaThe experimental results of the chip removing system operation are presented. The main aim of them was to optimize suction system of the panel saw Fx3 and its follower Fx550. The attention was focused on the upper casing, which was the part of removing system. Within the framework of the work a systematic experimental study of pressure distribution in the casing during operation of the selected rotational speed of saw blade with...
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Sensitivity of entanglement decay of quantum-dot spin qubits to the external magnetic field
PublikacjaWe study the decay of entanglement of quantum-dot electron-spin qubits under hyperfine-interaction-mediated decoherence.We show that two-qubit entanglement of a single entangled initial state may exhibit decay characteristic of two disentanglement regimes in a single sample, when the externalmagnetic field is changed. The transition is manifested by the suppression of time-dependent entanglement oscillations which are superimposed...
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Preparation of porous TiO2 films by means of pulsed laser deposition for photocatalytic applications
PublikacjaIn this work the preparation and structure properties of porous thin films of TiO2 were investigated. The films were produced by means of the pulsed laser deposition technique using laser pulses at 266nm (10Hz) and at fluencies of 1-3.5J/cm2. The process was performed in vacuum using O2 buffer gas and films were deposited on the SiO2 glass or Si substrate. X-ray diffraction (XRD) and Raman analysis of the structure and chemical...
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A correlation between electron-hole pair radii and magnetomodulation of exciplex fluorescence in electron donor-electron acceptor organic systems
PublikacjaElectric field dependencies of electromodulated photoluminescence and magnitudes of the magnetic-field effect on photoluminescence havebeen measured in vacuum-evaporated films of m-MTDATA [4,4',4"-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine]:bathophe-nanthroline, m-MTDATA:BCP (bathocuproine), as well as 4,4',4"-tris[2-naphthyl(phenyl)amino]triphenylamine:BCP. The Sano-Tachiya-Noolandi-Hong extension of standard Onsager...
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Spatio-Temporal Validation of GNSS-Derived Global Ionosphere Maps Using 16 Years of Jason Satellites Observations
PublikacjaExisting ionospheric models perform very well in mapping the calm state of the ionosphere. However, the problem is accurately determining the total electron content (TEC) for disturbed days. Knowledge of the exact electron density is essential for single−frequency receivers, which cannot eliminate the ionospheric delay. This study aims to investigate temporal and spatial variability in the distribution of TEC based on differences...
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The distributed model predictive controller for the nuclear power plant turbo-generator set
PublikacjaTypically there are two main control loops with PI controllers operating at each turbo-generator set. In this paper a distributed model predictive controller DMPC, with local QDMC controllers for the turbine generator, is proposed instead of a typical PI controllers. The local QDMC controllers utilize step-response models for the controlled system components. These models parameters are determined based on the proposed black-box...
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The Effect of Full-Cell Impregnation of Pine Wood (Pinus sylvestris L.) on Changes in Electrical Resistance and on the Accuracy of Moisture Content Measurement Using Resistance Meters
PublikacjaThe impact of the full-cell impregnation of pine wood was investigated with respect to changes in electrical resistance and the accuracy of moisture content measurement. This study compared the resistance of impregnated and untreated pine timber harvested from the northern part of Poland (Pomeranian region). The wood was impregnated by the vacuum-pressure method. The preservative (TANALITH E 3475) and coloring (TANATONE 3950) agents...
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Optimization of chip removing system operation in circular sawing machine
PublikacjaThe paper presents the optimization of the wood chips removing system in the sliding table saw. Chips are generated during the cutting of the material. The attention was focused on the upper casing of mentioned system. The methodical experimental studies of the pressure distribution inside the casing during the wood chip removing operation for the selected rotational speed of saw blade with a diameter of 300 mm and 450 mm were...
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Determination of pitting corrosion stage of stainless steel by galvanodynamic impedance spectroscopy
PublikacjaThis paper investigates the methodology for differentiation of multistep process of pitting corrosion of AISI 304 stainless steel in the environment of iron (III) chloride. Measurements were performed using Galvanodynamic Electrochemical Impedance Spectroscopy (GDEIS). Application of this methodology allowed monitoring of natural corrosion process without external current (IDC = 0A) nor potential perturbation of the system. Applied...
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MACHINE LEARNING APPLICATIONS IN RECOGNIZING HUMAN EMOTIONS BASED ON THE EEG
PublikacjaThis study examined the machine learning-based approach allowing the recognition of human emotional states with the use of EEG signals. After a short introduction to the fundamentals of electroencephalography and neural oscillations, the two-dimensional valence-arousal Russell’s model of emotion was described. Next, we present the assumptions of the performed EEG experiment. Detail aspects of the data sanitization including preprocessing,...
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Design of synchronous generator two inputs regulator based on hinf control theory.
PublikacjaThe power system is highly nonlinear system, its dynamics depends on system network configuration, system loading… etc. To overcome the above mentioned difficulties and fulfill the performance requirements the different control methods are considered and tested for design of synchronous generator control system. Application of the H optimization method to synchronous generator regulator based on measurement of generator voltage...
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Design of synchronous generator voltage regulator based on h control theory
PublikacjaThe power system is highly nonlinear system, which dynamics depends on system network configuration, system loading…etc. To overcome the above mentioned difficulties and to fulfill the performance requirements the different control methods are considered and tested for application to generating control unit. Application of the H optimization method to automatic voltage regulator is studied in this paper. Simulation results have...
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DETERMINATION OF SP3 FRACTION IN ta-C COATING USING XPS AND RAMAN SPECTROSCOPY
PublikacjaThe paper presents results of studies on the structure of tetrahedral amorphous carbon films (ta-C) with a thickness in the range from 20 to 280 nm, deposited using pulsed vacuum arc technique with an electromagnetic Venetian blind plasma filter. The results of the phase structure analysis, obtained using visible Raman spectroscopy and UV Raman spectroscopy methods, showed a strong dependence of the results on the presence, on...
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Wood Moisture-Content Measurement Accuracy of Impregnated and Nonimpregnated Wood
PublikacjaThe influence of the impregnation process of pine wood (Pinus sylvestris L.) samples on the electrical resistance changes and the moisture-content measurement accuracy is presented in this paper. In this study, the resistances of impregnated and nonimpregnated green pine timber harvested from northern Poland were compared. An impregnation method based on a vacuum-pressure chamber was used. Copper salts were applied as the impregnated...
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A new procedure for the determination of distillation temperature distribution of high-boiling petroleum products and fractions
PublikacjaThe distribution of distillation temperatures of liquid and semi-fluid products, including petroleum fractions and products, is an important process and practical parameter. It provides information on properties of crude oil and content of particular fractions, classified on the basis of their boiling points, as well as the optimum conditions of atmospheric or vacuum distillation. At present, the distribution of distillation temperatures...
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Tribo-Environment Dependent Chemical Modification of Sliding Interfaces in Ultrananocrystalline Diamond Nanowall Film: A Correlation with Friction and Wear
PublikacjaTribological properties of ultrananocrystalline diamond nanowall (UNCD NW) films were investigated quantitatively in three different and controlled tribo-environmental conditions, proposing the passivation and graphitization mechanisms. However, these mechanisms are rather complicated and possibly can be understood in well-controlled tribological conditions. It was shown that the friction and wear of these films were high in highPage 1...
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Laplace domain BEM for anisotropic transient elastodynamics
PublikacjaIn this paper, we describe Laplace domain boundary element method (BEM) for transient dynamic problems of three-dimensional finite homogeneous anisotropic linearly elastic solids. The employed boundary integral equations for displacements are regularized using the static traction fundamental solution. Modified integral expressions for the dynamic parts of anisotropic fundamental solutions and their first derivatives are obtained....
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Dirac fermions and possible weak antilocalization in LaCuSb2
PublikacjaLayered heavy-metal square-lattice compounds have recently emerged as potential Dirac fermion materials due to bonding within those sublattices. We report quantum transport and spectroscopic data on the layered Sb square-lattice material LaCuSb2. Linearly dispersing band crossings, necessary to generate Dirac fermions, are experimentally observed in the electronic band structure observed using angle-resolved photoemission spectroscopy,...
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Optimization of the femtosecond laser impulse for excitation and the Spin-Orbit mediated dissociation in the NaRb Dimer
PublikacjaWe study the dynamics of multiple coupled states under the influence of an arbitrary time-dependent external field to investigate the femtosecond laser-driven excitation and the spin-orbit mediated dissociation in the NaRb dimer. In this process, the dimer is excited from the ground triplet state 1^3Sigma+ to the 1^3Pi state using the femtosecond laser impulse and the spin-orbit coupling between the 1^3Pi and 2^1Sigma+ states results...
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Hydroxyapatite deposition on the laser modified Ti13Nb13Zr alloy
PublikacjaThe Ti13Nb13Zr alloy was subjected to laser modification with the Nd:YAG laser provided that such treatment would increase the surface roughness followed improved adhesion of hydroxyapatite (HAp) coatings The hydroxyapatite was deposited by electrophoretic method in suspension of 0.5 g HA powder and 100 ml ethyl alcohol. The deposition was carried out for 10 min at 10 V voltage followed by drying at room temperature for 24 h and...
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Experimental investigation of two-phase thermosyphon heat exchanger charged with acetone
PublikacjaThis paper presents thermal characteristics of prototype of a two-phase thermosyphon heat exchanger (TPTHEx) charged with acetone as a working fluid. The TPTHEx consists of two horizontal cylindrical vessels connected by two risers and a downcomer. Tube bundles placed in the lower and upper cylinders work as an evaporator and a condenser, respectively. The tested TPTHEx operates in a vacuum. Therefore, the working liquid is boiled...
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Design of control algorithms for mobile robots in an environment with static and dynamic obstacles
PublikacjaThis article proposes the construction of autonomous mobile robots and designing of obstacle avoidance algorithms for them. Nowadays, mobile robots are gaining more and more popularity on the customer as well as industrial market, for example as automatic vacuum cleaners or lawnmowers. Obstacle avoidance algorithms play an important role in performance of this types of robots. The proposed algorithms were designed for builds with...
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Experimental analysis of chip removing system in circular sawing machine
PublikacjaPaper presents analysis of the process of removing the wood chips generated during the cutting of the material on the circular sawing machine. The attention is focused on the upper cover of the chip removing system. Within the framework of the work a systematic experimental study of pressure distribution in the cover during operation of the selected rotational speed of saw blade with a diameter of 300 mm and 450 mm was carried...
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Photoconduction and magnetic field effect on photoconduction in hole-transporting star-burst amine (m-MTDATA) films
PublikacjaPhotoconduction and magnetic field effect on photoconduction have been investigated as a function of electric field strength, excitation light intensity and wavelength in vacuum evaporated films of m-MTDATA (4,4′,4″-tris(N-(3-methylphenyl)-N-phenylylamino) triphenylamine), the starburst amine commonly used as hole-transporting material in organic light-emitting diodes. The photocurrent is found to be generated by the singlet exciton...
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A Quantitative Investigation of Dislocation Density in an Al Matrix Composite Produced by a Combination of Micro-/Macro-Rolling
PublikacjaAn aluminum matrix composite with dispersed carbon nanotubes (CNTs) was produced via flake powder metallurgy using a micro-rolling process and vacuum hot pressing (VHP), followed by conventional rolling using a macro-rolling process. The microstructure and mechanical properties of the produced composites were studied. In addition, a new quantitative model was introduced to study the dislocation density based on the microstructural...
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Combined spline wavelet decomposition for 3d seafloor imaging from multibeam sonar echoes
PublikacjaThe paper proposes combined spline-wavelet approach to the raw echoes seaflor imaging from Multibeam Sonar System (MBSS) records. Wavelet representation is closely related to image representation, due to its unique approximations properties. Splines have the best approximation properties among all known wavelets of a given order, so they are best suited for approximating of smooth seafloor surface. Additionaly, wavelet bases have...