Search results for: UNSTEADY CREEP
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The use of liquid crystal thermography TLC and particle image velocimetry PIV in selected technical applications
PublicationNowadays, the energy cost is very high and this problem is carried out to seek techniques for improvement of the aerothermal and thermal (heat flow) systems performances in different technical applications. The transient and steady-state techniques with liquid crystals for the surface temperature and heat transfer coefficient or Nusselt number distribution measurements have been developed. The flow pattern produced by transverse...
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Application of the fluid–structure interaction technique for the analysis of hydrodynamic lubrication problems.
PublicationFluid–structure interaction technique seems to be one of the most promising possibilities for theoretical analysis of lubrication problems. It allows coupling of different physical fields in one computational task, taking into account the interaction between them. In this article, two sets of fluid–structure interaction analyses focusing on the bearing performance evaluation are presented. One analysis was applied to a water-lubricated...
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Alternative diagnostic method applied on marine diesel engines having limited monitoring susceptibility
PublicationThe paper presents a method of technical state evaluation of working spaces of a marine diesel engine at the limited control susceptibility. The method foresees making a diagnosis of the engine's working spaces on the basis of measurements of the exhaust gas pressure in the channels connecting engine cylinders with the turbocharger's turbine. Diagnostic measurements are carried out at representative (comparative) steady loads depending...
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Trustworthiness and Subversion in Large Service- Oriented Multi-Agent Systems under Virtual Anonymity and Blind Provider Selection
PublicationTo promote honest service provision in multi-agent systems, a Computational Trustworthiness and Rating scheme collects service ratings and computes agents' trustworthiness levels (TLs). Studies of existing schemes fail to reflect closed-loop dynamics of TLs arising from the mutual influence of agents' behavior and TLs, and to capture relevant properties. Recent simulative and analytical models produce results tied to a particular...
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Synthesis of a state feedback controller for an averaging tank with variable filling
PublicationIn paper, a nonlinear averaging tank with variable filling is considered. The main purpose of this research work was the modelling and control system synthesis of an averaging tank. The control objectives included ensuring stability and zero steady-state error of the system and achieving settling time as short as possible, while maintaining a minimal overshoot. In order to achieve the intended purpose, firstly a mathematical model...
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Novel application of dynamic electrochemical impedance monitoring to a cataphoretic coating process
PublicationThe paper presents a novel method of on-line impedance monitoring of cataphoretic coating application process. Utilization of dynamic electrochemical impedance spectroscopy (DEIS) overcame the fundamental problem connected with non-stationarity of the aforementioned coating deposition process, which eliminates classical impedance spectroscopy technique from a real-time description of cataphoresis. The paper illustrates selected examples...
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Parallel Implementation of the Discrete Green's Function Formulation of the FDTD Method on a Multicore Central Processing Unit
PublicationParallel implementation of the discrete Green's function formulation of the finite-difference time-domain (DGF-FDTD) method was developed on a multicore central processing unit. DGF-FDTD avoids computations of the electromagnetic field in free-space cells and does not require domain termination by absorbing boundary conditions. Computed DGF-FDTD solutions are compatible with the FDTD grid enabling the perfect hybridization of FDTD...
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MULTI-OBJECTIVE OPTIMIZATION PROBLEM IN THE OptD-MULTI METHOD
PublicationNew measurement technologies, e.g. Light Detection And Ranging (LiDAR), generate very large datasets. In many cases, it is reasonable to reduce the number of measuring points, but in such a way that the datasets after reduction satisfy specific optimization criteria. For this purpose the Optimum Dataset (OptD) method proposed in [1] and [2] can be applied. The OptD method with the use of several optimization criteria is called...
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Programmatic Simulation of Laser Scanning Products
PublicationThe technology of laser scanning is widely used for producing three-dimensional digital representations of geographic features. The measurement results are usually available in the form of 3D point clouds, which are often used as a transitional data model in various remote sensing applications. Unfortunately, while the costs of Light Detection And Ranging scanners have dropped significantly in recent years, they are still considered...
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The importance of the shape of the protein–water interface of a kinesin motor domain for dynamics of the surface atoms of the protein
PublicationA single kinesin motor domain immersed in water has been investigated using molecular dynamics. It has been found that local properties of water in the solvation shell change along with the nature of the neighboring protein surface. However, a detailed analysis leads to the conclusion that the geometrical features of hydrogen bonds and overall structure of kinesin hydration water are not very different from bulk water. The local...
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Synthesis and structural properties of (Y, Sr)(Ti, Fe, Nb)O3−δ perovskite nanoparticles fabricated by modified polymer precursor method
PublicationThe yttrium, iron and niobium doped-SrTiO3 powders have been successfully fabricated by a modified low–temperature synthesis method from a polymer complex. The usage of strontium hydroxide precursor instead of conventional strontium nitrate or strontium carbonate provides to the possibility of significant decrease of annealing temperature. It allows to prepare a material with sphere-shape grains of nanometric size (15–70 nm). The...
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Alternative Methods of Preparation of Soluble Keratin from Chicken Feathers
PublicationHuge amount of keratinous waste, especially birds’ feathers, demands more value-added application instead of dumping. The present work reports the results of experiments aimed at preparing soluble keratin useful for novel bioproduct formation. The effect of thermo-chemical treatments with various reducing agents, i.e. 2-mercaptoethanol, dithiothreitol, sodium m-bisulphite, and sodium bisulphite, as well as sodium hydroxide, on...
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Unusual behavior of secondary amine group as a leaving group
PublicationIn our recent project we focused on reactivity of2,2-dimethyl-4,6-dioxane-1,3-dione carbamoilo- and thiocarbamoylo- derivatives as a ketenesource. Meldrum`s acid derivatives after thermal decomposition gives substituted keteneswith stoichiometric yield, that can be trapped with various spectrum of nucleophiles likealcohols, thiols, amine, imines etc. In case of5-[3-(dimethylamino)-sulfanyl-propyliden]-2,2-dimethyl-1,3-dioxane-4,6-dione...
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The importance of the shape of the protein-water interface of a kinesin motor domain for dynamics of the surface atoms of the protein
PublicationSingle kinesin motor domain immersed in water has been investigated using molecular dynamics. It has been found that local properties of water in solvation shell change along with the nature of neighboring protein surface. However, a detailed analysis leads to the conclusion that the geometrical features of hydrogen bonds and overall structure of kinesin hydration water is not very different from bulk water. The local values of...
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Information Retrieval in Wikipedia with Conceptual Directions
PublicationThe paper describes our algorithm used for retrieval of textual information from Wikipedia. The experiments show that the algorithm allows to improve typical evaluation measures of retrieval quality. The improvement of the retrieval results was achieved by two phase usage approach. In first the algorithm extends the set of content that has been indexed by the specified keywords and thus increases the Recall value. Then, using the...
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Histogram of Oriented Gradients with Cell Average Brightness for Human Detection
PublicationA modification of the descriptor in a human detector using Histogram of Oriented Gradients (HOG) and Support Vector Machine (SVM) is presented. The proposed modification requires inserting the values of average cell brightness resulting in the increase of the descriptor length from 3780 to 3908 values, but it is easy to compute and instantly gives ≈ 25% improvement of the miss rate at 10‒4 False Positives Per Window (FPPW). The...
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Surface Dielectric Barrier Discharge Plasma Actuators
PublicationThis paper presents a part of the works conducted in the Plasmaero European project (task 1.1) on surface dielectric barrier discharge actuators applied to airflow control. The study is divided into several parts. In the first part, the goal is to enhance the electric wind produced by a typical single DBD actuator by optimization of the active electrode shape. For instance, the use of a thin wire instead of a plate air-exposed...
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Do Leonardo da Vinci’s drawings, room acoustics and radio astronomy have anything in common?
PublicationAfter introducing Leonardo da Vinci’s (LdV) predecessors in the field of light propagation research, his drawings on the topic of reflecting light by a spherical mirror are analysed. The discovery of LdV is presented, according to which, at an infinitely distant source of rays, a small fragment of the canopy is enough to generate a focus, while the rest of the mirror forms a caustic for which LdV did not indicate an application....
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Tensor Decomposition for Imagined Speech Discrimination in EEG
PublicationMost of the researches in Electroencephalogram(EEG)-based Brain-Computer Interfaces (BCI) are focused on the use of motor imagery. As an attempt to improve the control of these interfaces, the use of language instead of movement has been recently explored, in the form of imagined speech. This work aims for the discrimination of imagined words in electroencephalogram signals. For this purpose, the analysis of multiple variables...
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Three Principles for Healthy Living with Light and Lighting
PublicationThe lockdown measures applied to cities and towns during the worldwide Covid-19 pandemic have had a widespread impact on people’s lives. Some have found themselves confined to their homes, with limited social contact and a reduced quality of life. Others have found that the lockdown improved their wellbeing, as more time was spent outside, instead of commuting and working in an office building, plus the benefits of spending increased...
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OECD Guidelines for Micro Statistics on Household Wealth
PublicationThis report reflects the contributions of members of the OECD Expert Group on Micro Statistics on Household Income, Consumption and Wealth. Members of the Expert Group included representatives from National Statistical Offices – Bob McColl (Chair, Australia); Alison Hale (Canada); Andre Bustamante and David Niculcar (Chile); Henrik Sejerbo Soerensen (Denmark); Yafit Alfandari (Israel); Shinji Yoshioka (Japan); Sinho Kim...
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Dietary intervention with beetroot juice during doxorubicin cancer chemotherapy in vivo reduces markers of oxidative stress
PublicationCancer chemotherapy with doxorubicin, despite high antitumor activity and broad spectrum of this drug, is on decline due to toxic side effects. The clinical efficacy of anthracyclines have continuously prompted the search for new adjuvants to alleviate undesirable side toxicity incurred by this group of cytostatics. The recent approaches involve the application of synthetic or purified natural antioxidants in combination with doxorubicin...
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DST-Based Detection of Non-cooperative Forwarding Behavior of MANET and WSN Nodes
Publication. Selfish node behavior can diminish the reliability of a mobile ad hoc network (MANET) or a wireless sensor network (WSN). Efficient detection of such behavior is therefore essential. One approach is to construct a reputation scheme, which has network nodes determine and share reputation values associated with each node; these values can next be used as input to a routing algorithm to avoid end-to-end routes containing ill-reputed...
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Durability of Asphalt Concrete Subjected to Deteriorating Effects of Water and Frost
PublicationThe paper presents testing of the detrimental effects of water and frost on asphalt pavements. It included laboratory testing of 5 fatigue life of asphalt concrete that was subjected to action of water and frost and field testing of damages caused by water and frost on 6 existing asphalt pavements, such as stripping, raveling, and potholes. Laboratory simulation of water and frost action was based on the 7 original AASHTO T283...
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Increasing the Seismic Resistance of Wood-frame Buildings by Applying PU Foam as Thermal Insulation
PublicationWood-frame buildings are very common in regions that are exposed to earthquakes. Most of residential buildings are constructed using this technology; therefore, the seismic resistance of them is really essential in order to prevent human losses and structural damage. The aim of the present article is to show the results of the detailed numerical FEM analysis focused on the seismic behaviour of the wood-frame house with different...
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Borrowing Images of Empire. The contribution of research on the artistic influence of the Holy Roman Empire on Polish Romanesque architecture in the eleventh and twelfth centuries
PublicationAlthough knowledge concerning Romanesque architecture in Poland has developed over many years, most cathedrals and ducal or royal seats have not been comprehensively examined. Moreover, a substantial number of contemporary scholarly works have erased the thin line between material evidence and its interpretation. As a consequence, the architectural remains of Polish Romanesque edifices are often considered the basis for wider comparative...
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Theoretical Investigation of the Electron-Transfer Dynamics and Photodegradation Pathways in a Hydrogen-Evolving Ruthenium-Palladium Photocatalyst
PublicationTime-dependent density functional theory calcula- tions combinedwith the Marcus theory of electron transfer (ET) were app lied on the molecular photocatalys t [(tbbpy) 2 Ru(tpph z)PdC l 2 ] 2 + in order to elucidate thelight-in- duced relaxation pathways populated upon excitation in the longer wavelength range of its absorption spectrum. The computational resultsshow that after the initial excitation, metal (Ru) to ligand (tpphz)chargetransfer...
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Implementing a CSR Strategy in a Small Enterprise - a Case Study
PublicationAs a result of employees’ meetings conducted according to Kaizen workshops formula and seeking new development directions for the company (including CSR actions) various product and service innovations have been implemented. Also a market niche has been discovered, and as a consequence the company gained another profitable aspect of the business activity. The atmosphere and contribution in performing tasks have improved among...
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Mathematical modelling of two-step nitrification-denitrification for treatment of sludge digester liquors: influence of nitrite (NO2-N) on the process kinetics
PublicationSeparate treatment of the sludge digester liquors is an alternative for expansion of the mainstream treatment line. In order to reduce the oxygen demand for nitrification and organic carbon demand for denitrification, a shortcut in the nitrogen conversion pathway has been promoted in recent years, i.e. nitrification-denitrification via NO2-N instead of NO3-N. Although NO2-N is a common intermediate product of nitrification and...
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A method of determining and visualizing safe motion parameters of a ship navigating in restricted waters
PublicationThe paper presents a method of displaying ship collision avoidance information which is based on an unconventional Collision Threat Parameters Area (CTPA) technique. The solution presented here extends CTPA's functionality from past works by supporting navigation in restricted waters and handling ship domains analytically instead of numerically. It visualizes potential navigational threats as well as possible collision avoidance...
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Looking through the past: better knowledge retention for generative replay in continual learning
PublicationIn this work, we improve the generative replay in a continual learning setting to perform well on challenging scenarios. Because of the growing complexity of continual learning tasks, it is becoming more popular, to apply the generative replay technique in the feature space instead of image space. Nevertheless, such an approach does not come without limitations. In particular, we notice the degradation of the continually trained...
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Active Learning on Ensemble Machine-Learning Model to Retrofit Buildings Under Seismic Mainshock-Aftershock Sequence
PublicationThis research presents an efficient computational method for retrofitting of buildings by employing an active learning-based ensemble machine learning (AL-Ensemble ML) approach developed in OpenSees, Python and MATLAB. The results of the study shows that the AL-Ensemble ML model provides the most accurate estimations of interstory drift (ID) and residual interstory drift (RID) for steel structures using a dataset of 2-, to 9-story...
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Actual and reference evapotranspiration for a natural, temperate zone fen wetland – Upper Biebrza case study
PublicationEvapotranspiration is the key and predominant component of the water balance in wetlands. Direct evapotranspiration measurements are challenging in wetlands due to their remoteness and high surface water level. This article describes the actual (ETa and reference evapotranspiration (ET0) from a cultivated wet meadow located in the Biebrza National Park – the largest national park in north-east Poland, Central Europe. The data were...
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Anaerobic consortia mediate Mn(IV)-dependent anaerobic oxidation of methane
PublicationManganese-dependent anaerobic oxidation of methane (Mn-AOM) is a major methane sink and vital to mitigating global warming. However, it is difficult for microorganisms to mediate electron transfer between the hardly dissolved CH4 and insoluble Mn(IV) minerals, leading to poor understanding of species mediating Mn-AOM. This study successfully enriched an anaerobic consortium mediating AOM driven by Mn-dependent respiratory growth,...
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The influence of selected strain-based failure criteria on ship structure damage resulting from a collision with an offshore wind turbine monopile
PublicationOffshore wind farms are developing well all over the world, providing green energy from renewable sources. The evaluation of possible consequences of a collision involves Finite Element computer simulations. The goal of this paper was to analyse the influence of selected strain-based failure criteria on ship damage resulting from a collision with an offshore wind turbine monopile. The case of a collision between an offshore supply...
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Application of probabilistic tools to extend load test design of bridges prior to opening
PublicationLoad tests of bridges are widely performed in a large number of countries. Deterministic comparison of measurement results to the theoretical, FEM (finite element method)-based outcomes with possible further calibration is mostly applied. Sometimes, the data collected in the tests are also used to calibrate the reliability factors of bridge structures or their components. This work proposes to complement the stage of the load test...
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On ship roll resonance frequency
PublicationThe paper deals with the problem of modeling of rolling motion under a variety of excitation parameters. Special emphasis is put on the analysis and prediction of the frequency of the resonant mode of rolling, since it is often an essential issue in terms of motion of a ship related to her safety against capsizing or excessive amplitudes of roll. The research is performed for both free rolling and excited rolling and it is based...
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Unusual divergence of magnetoacoustic beams
PublicationTwo-dimensional magnetosonic beams directed along a line forming a constant angle h with the equilibrium straight magnetic field are considered. Perturbations in a plasma are described by the system of ideal magnetohydrodynamic equations. The dynamics of perturbations in a beam are different in the cases of fast and slow modes, and it is determined by h and equilibrium parameters of a plasma. In particular, a beam divergence may...
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Multiscalar Control Based Airgap Flux Optimization of Induction Motor for Loss Minimization
PublicationBased on the induction motor model, considering the core loss resistance that accounts for magnetic characteristic saturation, a speed control approach is devised with an adaptive full-order (AFO) speed observer. The induction motor model analysis is done sincerely in a stationary reference frame. The control approach incorporates a flux reference generator designed to meet optimal operational circumstances and a nonlinear speed...
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Activity-based payments: alternative (anonymous) online payment model
PublicationElectronic payments are the cornerstone of web-based commerce. A steady decrease in cash usage has been observed, while various digital payment technologies are taking over. They process sensitive personal information raising concerns about its potentially illicit usage. Several payment models that confront this challenge have been proposed. They offer varying levels of anonymity and readiness for adoption. The aim of this study...
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Justification of quasi-stationary approximation in models of gene expression of a self-regulating protein
PublicationWe analyse a model of Hes1 gene transcription and protein synthesis with a negative feedback loop. The effect of multiple binding sites in the Hes1 promoter as well as the dimer formation process are taken into account. We consider three, possibly different, time scales connected with: (i) the process of binding to/dissolving from a binding site, (ii) formation and dissociation of dimers, (iii) production and degradation of Hes1...
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Photophysics of Soret-Excited Tin(IV) Porphyrins in Solution
PublicationThe photophysics of low-chlorin tin(IV) tetraphenylporphyrin dihydroxide, a core building block for axially substituted supramolecular tin porphyrin constructs, has been studied in a variety of hydrogen-bonding, nonpolar, and aprotic polar solvents using steady-state, nanosecond, and femtosecond time-resolved emission, and femtosecond time-resolved absorption methods. In hydrogen-bonding solvents the metalloporphyrin exists as...
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Development of different methods for drugs and psychoactive substances extraction from hair samples and their identification based on HPLC-ESI-QTOF analysis
PublicationOver the past decade, the use of non-controlled designer drugs and drug of abuse has rapidly increased. Hair, as a human matrix, enables detection of drugs incorporated into its structure. Studies of presence and identification of drug metabolites in human hair samples has been performed using liquid chromatography electrospray ionization quadrupole time of flight mass spectrometry (HPLC-ESI-QTOF-MS) with steady alternation of...
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Self-Association of Amphotericin B: Spontaneous Formation of Molecular Structures Responsible for the Toxic Side Effects of the Antibiotic
PublicationAmphotericin B (AmB) is a lifesaving antibiotic used to treat deep-seated mycotic infections. Both the pharmaceutical activity and highly toxic side effects of the drug rely on its interaction with biomembranes, which is governed by the molecular organization of AmB. In the present work we present detailed analysis of self-assembly of AmB molecules in different environments, interesting from the physiological standpoint, based...
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Systematic comparison of a biotrickling filter and a conventional filter for the removal of a mixture of hydrophobic VOCs by Candida subhashii
PublicationThis work systematically compared the potential of a conventional fungal biofilter (BF) and a fungal biotrickling filter (BTF) for the abatement of a mixture of hydrophobic volatile organic compounds (VOCs). Candida subhashii was herein used for the first time, to the best of the author's knowledge, to remove n-hexane, trichloroethylene, toluene and α-pinene under aerobic conditions. C. subhashii immobilized on polyurethane foam...
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Analytical Study of Sliding Instability due to Velocity- and Temperature-Dependent Friction
PublicationThe instability of sliding causes deterioration of performance characteristics of tribosystems and is undesired. To predict its occurrence, the motion of a body of a one-degree-of-freedom system with friction is investigated about the steady sliding equilibrium position. The motion equation is formulated with the friction coefficient dependent on the sliding velocity and contact temperature changing due to transient heat conduction...
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Analysis of Induced Voltages and Power Losses in High Voltage Power Cables for Selected Methods of Cables Sheaths Bonding
PublicationPower is increasingly supplied to city centres with 110 kV cable lines. This is a convenient way to supply power, and practically the only one possible in areas of dense urban development. A high-voltage cable contains a coaxial metallic sheath, in which in normal operation and in fault conditions (during short-circuits) significant line-to-earth voltages can be induced, which threatens electric shock and/or damage to the cable’s...
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ROBOT TYPU QUADROCOPTER STEROWANY MIKROKONTROLERAMI O NIEWIELKIEJ MOCY OBLICZENIOWEJ
PublicationWspółczesna robotyka rozwija się bardzo dynamicznie. Coraz więcej osób prywatnych i inżynierów konstruuje różnego rodzaju pojazdy mobilne. Dlatego autorzy niniejszego referatu postawili sobie następującą tezę: możliwa jest budowa latającego robota mobilnego na bazie kontrolera o niskiej mocy obliczeniowej oraz prostego regulatora, i podjęli się jej udowodnienia.
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Assessment of organic coating degradation via local impedance imaging
PublicationThe paper presents a new approach to organic coating condition evaluation at micrometer scale using localized impedance measurements. It is based on atomic force microscopy (AFM) in contact mode. Impedance is measured between conductive AFM tip and metal substrate covered with organic coating. A single-frequency voltage perturbation signal is applied between the electrodes and current response signal is registered. As the tip is...
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General paradigm for distilling classical key from quantum states
PublicationIn this paper, we develop a formalism for distilling aclassical key from a quantum state in a systematic way, expandingon our previous work on a secure key from bound entanglement(Horodecki et al., 2005). More detailed proofs, discussion, andexamples are provided of the main results. Namely, we demonstratethat all quantum cryptographic protocols can be recast in away which looks like entanglement theory, with the only changebeing...