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Search results for: fundamenty specjalne
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Cichy sonar - stan aktualny i perspektywy
PublicationW zastosowaniach militarnych często istnieje potrzeba prowadzenia obserwacji w sposób skryty za pomocą urządzeń emitujących sygnały trudne do przechwycenia przez przeciwnika. Rozwiązania stosowane w cichych radarach stanowiły punkt wyjścia do opracowania cichego sonaru. Prace nad projektem rozpoczęto na Politechnice Gdańskiej w roku 2010 w ramach Grantu NCBiR i są one dalej kontynuowane. W celu zachowania w cichym sonarze warunków...
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Diagnostyka nakładek stykowych z wykorzystaniem systemu wizyjnego 3D
PublicationKolejowe pojazdy szynowe są szczególnym typem ruchomych odbiorników energii elektrycznej. Zasilane są one zazwyczaj z górnej sieci jezdnej za pośrednictwem odbieraka prądu, zainstalowanego na dachu pojazdu. Istotnym elementem odbieraka jest ślizgacz, zawierający najczęściej dwie nakładki stykowe. Odbiór prądu zapewniony jest przez ruchomy zestyk pomiędzy przewodem jezdnym a nakładkami stykowymi. Poprawny odbiór prądu uwarunkowany...
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Drgania tarcz łożyskowych silników asynchronicznych wymuszane siłami elektromagnetycznymi
PublicationW silnikach dużej mocy przyczyny drgań i hałasu tarcz łożyskowych pochodzą głównie od pracy łożysk. W widmach drgań tarcz silników asynchronicznych małej mocy występują dominanty o częstotliwościach niezwiązanych w żaden sposób z pracą łożysk tocznych. Celem niniejszej rozprawy jest określenie mechanizmów wiążących drgania tarcz łożyskowych z wymuszeniami elektromagnetycznymi stojana. Przyjętymi metodami realizacji celu rozprawy...
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Budownictwo morskie. Wybrane zagadnienia wraz z przykładami obliczeniowymi
PublicationJednym z głównych zadań projektanta budowli morskiej jest poprawne uwzględnienie kombinacji oddziaływań takich czynników jak: falowanie, prądy morskie, wiatr, zjawiska sejsmiczne. Innym istotnym elementem jego pracy jest zagwarantowanie spełnienia warunków stateczności budowli poprzez umiejętną analizę współoddziaływania środowiska morskiego i budowli morskiej z jednoczesnym interaktywnym projektowaniem geometrii budowli oraz doborem...
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Vibro-Electrical Behavior of a Viscoelastic Piezo-Nanowire in an Elastic Substrate Considering Stress Nonlocality and Microstructural Size-Dependent Effects
PublicationThis research deals with dynamics response of a Pol/BaTiO3 nanowire including viscosity influences. The wire is also impressed by a longitudinal electric field. Hamilton's principle and Lagrangian strains are employed in conjunction with a refined higher-order beam theory in order to derive equations of motion. By combining nonlocality and small size...
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Decision-Making Models of the Human-Operator as an Element of the Socio-Technical Systems
PublicationThe authors of the chapter proved that the fundamental intellectual processes, which lie on the basis of decision-making behavior of the human-operator, could be identified on the bases on the analogies with the devices (elements). The basic intellectual processes of the Rational decision-making models can be adequately identified by the transient processes of the PID-controller; the intellectual processes of the Bounded Rationality...
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Identification of models and signals robust to occasional outliers
PublicationIn this paper estimation algorithms derived in the sense of the least sum of absolute errors are considered for the purpose of identification of models and signals. In particular, off-line and approximate on-line estimation schemes discussed in the work are aimed at both assessing the coefficients of discrete-time stationary models and tracking the evolution of time-variant characteristics of monitored signals. What is interesting,...
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Identification of models and signals robust to occasional outliers
PublicationIn this paper estimation algorithms derived in the sense of the least sum of absolute errors are considered for the purpose of identification of models and signals. In particular, off-line and approximate on-line estimation schemes discussed in the work are aimed at both assessing the coefficients of discrete-time stationary models and tracking the evolution of time-variant characteristics of monitored signals. What is interesting,...
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Maszyny elektryczne wokół nas. Poszukiwanie dróg do nauczania na kierunku Elektrotechnika Politechniki Gdańskiej = Electrical machines around us. searching for teaching ways at electrical engineering of the Gdansk University of Technology
PublicationStreszczenie angielskie: This paper provides a summary of the didactic assumptions, goals and approach concerning the syllabus and description/modelling of electrical machines (EM) for teaching in the field of power electrical engineering at the Gdansk University of Technology. They have been used to write e-text book entitled "Electrical machines around us" that covered the lectures on electrical machines given for the second...
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Comparison of reproduction strategies in genetic algorithm approach to graph searching
Publicationgenetic algorithms (ga) are a well-known tool used to obtain approximate solutions to optimization problems. successful application of genetic algorithm in solving given problem is largely dependant on selecting appropriate genetic operators. selection, mutation and crossover techniques play a fundamental role in both time needed to obtain results and their accuracy. in this paper we focus on applying genetic algorithms in calculating...
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Numerical modeling of exciton impact in two crystalographic phases of the organo-lead halide perovskite (CH3NH3PbI3) solar cell
PublicationTo improve the power conversion efficiency of solar cells based on organo–lead halide perovskites, a detailed understanding of the device physics is fundamental. Here, a computational analysis of excitons impact is reported for these types of photocell. Numerical calculations based on the model, which take into account electronic charge carriers (electrons and holes), excitons and ions, have been carried out. The role of excitons...
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Neural networks and deep learning
PublicationIn this chapter we will provide the general and fundamental background related to Neural Networks and Deep Learning techniques. Specifically, we divide the fundamentals of deep learning in three parts, the first one introduces Deep Feed Forward Networks and the main training algorithms in the context of optimization. The second part covers Convolutional Neural Networks (CNN) and discusses their main advantages and shortcomings...
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Consistency of Quantum Computation and the Equivalence Principle.
PublicationThe equivalence principle, being one of the building blocks of general relativity, seems to be crucial for analysis of quantum effects in gravity. In this paper we consider the relation between the equivalence principle and the consistency of quantum information processing in gravitational field. We propose an analysis with a looped evolution consisting of steps both in the gravitational field and in the accelerated reference frame....
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The role of low-energy electrons in the charging process of LISA test masses
PublicationThe estimate of the total electron yield is fundamental for our understanding of the test-mass charging associated with cosmic rays in the Laser Interferometer Space Antenna (LISA) Pathfinder mission and in the forthcoming gravitational wave observatory LISA. To unveil the role of low energy electrons in this process owing to galactic and solar energetic particle events, in this work we study the interaction of keV and sub-keV...
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Disciplines and measures of information resilience
PublicationCommunication networks have become a fundamental part of many critical infrastructures, playing an important role in information delivery in various failure scenarios triggered e.g., by forces of nature (including earthquakes, tornados, fires, etc.), technology-related disasters (for instance due to power blackout), or malicious human activities. A number of recovery schemes have been defined in the context of network resilience...
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Determination of the minimal critical rotational speeds of the circular saw blades with the quasi-twin resonant frequencies
PublicationTo determine the minimal critical rotational speeds of the circular saw blades is the fundamental aspect of obtaining the range of the rotational operating speeds, by which the circular saw blade can work with required stability. While for the circular saw blades with full-homogeneous bodies the determination of such rotational speeds is the relatively low level of difficulty function, whereas for circular saw blades with more...
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Optimized Space Vector Modulation strategy for five phase voltage source inverter with third harmonic injection
PublicationThis paper presents a simple and an effective SVM algorithm for five-phase Voltage-Source Inverters with the possibility to control independently the voltage vectors for fundamental and auxiliary orthogonal subspaces. The essential benefit is that output voltage is generated using only four active voltage vectors with limited numbers of switching. In the proposed solution, four active vectors are arbitrary chosen, independent of...
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OCENA UZIEMIEŃ SŁUPÓW LINII ELEKTROENERGETYCZNYCH ZWŁASZCZA POSADOWIONYCH NA GRUNTACH O WYSOKIEJ REZYSTYWNOŚCI
PublicationW artykule została omówiona problematyka pomiaru i oceny właściwości uziemień słupów linii elektroenergetycznych z wykorzystaniem przebiegów wolno-i szybkozmiennych. Uzyskanie odpowiednio niskiej wartości rezystancji uziemienia słupa posadowionego na gruncie o rezystywności powyżej 1000Ωm może być trudne. Praca zawiera analizę zmian właściwości statycznych i udarowych uziemień w funkcji rezystywności...
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Pomiary uziemień słupów linii elektroenergetycznych
PublicationW odprowadzaniu do ziemi prądu zwarciowego lub piorunowego biorą udział elementy uziomu sztucznego słupa oraz jego fundamenty. Podczas pomiarów kontrolnych rezystancji lub impedancji takich uziemień powinny być uwzględniane oba elementy uziemienia. Ponadto procedura pomiarowa musi brać pod uwagę fakt, że uziemienia słupów linii są połączone równolegle poprzez przewody odgromowe. W artykule została omówiona problematyka pomiaru...
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Analiza możliwości automatycznego rozpoznawania zachowań zwierząt doświadczalnych
PublicationAutomatyzacja analizy zachowań zwierząt laboratoryjnych umożliwia szybką i obiektywną ocenę obserwacji. Rozwiązania w istniejących systemach skupiają się na detekcji prostych aspektów zachowań, która jest możliwa dzięki pomiarowi parametrów motorycznych zwierząt, ich punktów charakterystycznych czy kształtu ciała. Jednym z istotnych problemów w dziedzinie rozpoznania zachowań są zachowania złożone, dla których trudno jest zdefiniować...
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Analysis of Lombard speech using parameterization and the objective quality indicators in noise conditions
PublicationThe aim of the work is to analyze Lombard speech effect in recordings and then modify the speech signal in order to obtain an increase in the improvement of objective speech quality indicators after mixing the useful signal with noise or with an interfering signal. The modifications made to the signal are based on the characteristics of the Lombard speech, and in particular on the effect of increasing the fundamental frequency...
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NADZOROWANIE WYPOSAŻENIA DO MONITOROWANIA I POMIARÓW WEDŁUG WYMAGAŃ WYBRANYCH NORM ORAZ PRZEPISÓW PRAWNYCH
Publication: Przyrządy pomiarowe stanowią zasadniczy element złożonego systemu oceny jakości wyrobów na wszystkich etapach produkcji. Odpowiednio zaprojektowane procedury opisujące procesy kontrolne i pomiarowe, sprawnie zorganizowane i przeprowadzane operacje monitorowania i pomiarów parametrów procesów i produktów oraz skutecznie funkcjonujący nadzór nad wyposażeniem do monitorowania i pomiarów w organizacji są podstawą do wykazania, że...
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Dopants and gas modifiers in ion mobility spectrometry
PublicationThe ion mobility techniques, including the most commonly used drift-tube ion mobility spectrometry (IMS) and differential mobility spectrometry (DMS), are used successfully for the detection of a wide range of organic compounds in the gas phase. In order to improve detection quality, admixtures are added to gas streams flowing through the detector. Dopants mostly prevent the ionization of interfering chemicals however, better detection...
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A large family of filled skutterudites stabilized by electron count
PublicationThe Zintl concept is important in solid-state chemistry to explain how some compounds that combine electropositive and main group elements can be stable at formulas that at their simplest level do not make any sense. The electronegative elements in such compounds form a polyatomic electron-accepting molecule inside the solid, a ‘polyanion’, that fills its available energy states with electrons from the electropositive elements...
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The effect of adding a standard on the result of determination of polychlorinated biphenyls in bottom sediment samples
PublicationBottom sediments are a very important component of aquatic ecosystems. The sediment matrix is highly diverse and heterogeneous; in consequence, compounds entering the aquatic environment from different sources are considerably enriched at its surface. Bottom sediments are regarded as natural sorbents, since they accumulate many harmful substances, such as heavy metals and stable organic contaminants.Extraction is a key stage in...
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Playback Attack Detection: The Search for the Ultimate Set of Antispoof Features
PublicationAutomatic speaker verification systems are vulnerable to several kinds of spoofing attacks. Some of them can be quite simple – for example, the playback of an eavesdropped recording does not require any specialized equipment nor knowledge, but still may pose a serious threat for a biometric identification module built into an e-banking application. In this paper we follow the recent approach and convert recordings to images, assuming...
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Crank–Nicolson FDTD Method in Media Described by Time-Fractional Constitutive Relations
PublicationIn this contribution, we present the Crank-Nicolson finite-difference time-domain (CN-FDTD) method, implemented for simulations of wave propagation in media described by time-fractional (TF) constitutive relations. That is, the considered constitutive relations involve fractional-order (FO) derivatives based on the Grünwald-Letnikov definition, allowing for description of hereditary properties and memory effects of media and processes....
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Electrical properties of organic and perovskite systems used in solar cells
PublicationNowadays, a great progress in the areas of molecular and hybrid photovoltaics is observed. The devices based on organic and perovskite materials are getting attention mostly due to their low cost production process. However, their efficiency and stability are still lower than for inorganic materials which make them less popular. Therefore, a detailed understanding of the device physics is fundamental for organic and perovskite...
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The Latest Advances in Wireless Communication in Aviation, Wind Turbines and Bridges
PublicationPresent-day technologies used in SHM (Structural Health Monitoring) systems in many implementations are based on wireless sensor networks (WSN). In the context of the continuous development of these systems, the costs of the elements that form the monitoring system are decreasing. In this situation, the challenge is to select the optimal number of sensors and the network architecture, depending on the wireless system’s other parameters...
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Diamond investments – Is the market free from multiple price bubbles?
PublicationThe following study aims to investigate whether multiple price bubbles, in which the quoted market price of diamonds significantly deviates from their fundamental value, exist in the diamond market. It was conducted using ADF, SADF and GSADF tests, with the latter found to be an optimal form of evaluating the analysed issue. The presented results support the conclusion that the diamond market is not free from periods defined as...
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Analysis of volatile fraction of sweetie (Citrus maxima × Citrus paradisi) and its parent fruit using proton transfer reaction mass spectrometry
PublicationThe quality of the fruit is affected by several main ingredients and the aroma plays a fundamental role during the selection of fruit by consumers. In the case where several fruit have similar aromas and only one of them has specific health properties, it is very important to find the differences in the volatile organic compounds (VOCs) composition to distinguish these samples. Such situations are often found for hybrid fruit....
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Remote Monitoring of Environmental Pollutants
PublicationAtmospheric air quality is one of the key factors influencing human health. Air quality evaluation is not an easy task as the atmosphere is a complex system subjected to continuous changes in time. Observed progress in the development of measurement devices and technologies is fundamental for acquisition of more reliable information about condition and quality of atmospheric air. Unfortunately, this process leads to an increase...
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The occurrence and role of Nitrospira in nitrogen removal systems
PublicationApplication of the modern microbial techniques changed the paradigm about the microorganisms performing nitrification. Numerous investigations recognized representatives of the genus Nitrospira as a key and predominant nitrite-oxidizing bacteria in biological nutrient removal systems, especially under low dissolved oxygen and substrate conditions. The recent discovery of Nitrospira capable of performing complete ammonia oxidation...
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Effects of Surface Pretreatment of Titanium Substrates on Properties of Electrophoretically Deposited Biopolymer Chitosan/Eudragit E 100 Coatings
PublicationThe preparation of the metal surface before coating application is fundamental in determining the properties of the coatings, particularly the roughness, adhesion, and corrosion resistance. In this work, chitosan/Eudragit E 100 (chit/EE100) were fabricated by electrophoretic deposition (EPD) and both their microstructure and properties were investigated. The present research is aimed at characterizing the effects of the surface...
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Recent progress in the development of steroid sulfatase inhibitors – examples of the novel and most promising compounds from the last decade
PublicationThe purpose of this review article is to provide an overview of recent achievements in the synthesis of novel steroid sulfatase (STS) inhibitors. STS is a crucial enzyme in the biosynthesis of active hormones (including estrogens and androgens) and, therefore, represents an extremely attractive molecular target for the development of hormone-dependent cancer therapies. The inhibition of STS may effectively reduce the availability...
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Simulating Power Generation from Photovoltaics in the Polish Power System Based on Ground Meteorological Measurements—First Tests Based on Transmission System Operator Data
PublicationThe Polish power system is undergoing a slow process of transformation from coal to one that is renewables dominated. Although coal will remain a fundamental fuel in the coming years, the recent upsurge in installed capacity of photovoltaic (PV) systems should draw significant attention. Owning to the fact that the Polish Transmission System Operator recently published the PV hourly generation time series in this article, we aim...
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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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PRELIMINARY FIELD TESTS AND LONG-TERM MONITORING AS A METHOD OF DESIGN RISK MITIGATION: A CASE STUDY OF GDAŃSK DEEPWATER CONTAINER TERMINAL
PublicationAppropriate risk assessment plays a fundamental role in the design. . The authors propose a possible method of design risk mitigation, which follows recommendations included in Eurocode 7. The so-called “Observational Method” (OM) can produce savings in costs and programmes on engineering projects without compromising safety. The case study presented is a complex design solution that deals with the heavy foundations of a gantry...
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Information transfer during the universal gravitational decoherence
PublicationRecently Pikovski et al. (Nat Phys 11:668, 2015) have proposed in an intriguing universal decoherence mechanism, suggesting that gravitation may play a conceptually important role in the quantum-to-classical transition, albeit vanishingly small in everyday situations. Here we analyze information transfer induced by this mechanism. We show that generically on short time-scales, gravitational decoherence leads to a redundant information...
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Determination of the optimal curvature of the turnout diverging track for HSR using dynamic analysis
PublicationThe paper presents an analytical method of identifying the curvature of the turnout diverging track consisting of sections of varying curvature. Such turnout is mainly applied on High Speed Railway. Both linear and nonlinear (polynomial) curvatures of the turnout diverging track are considered in the paper. Obtained solutions enable to assume curvature values at the beginning and end point of the geometrical layout of the turnout.The...
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Modeling the impact of rotor movement on non-linearity of motor currents waveforms in high-speed PMSM drives
PublicationMotor current measurement techniques as well as predictive control algorithms for electric drives rely on an assumption of linear motor currents changes resulting from constant inverter output voltages. Recent research has reported that this assumption does not hold in motors with short electrical time constant, and in drives whose rotor position advances substantially during a control period. This paper proposes a simulation model...
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Theoretical Model of Acoustic Wave Propagation in Shallow Water
PublicationThe work is devoted to the propagation of low frequency waves in a shallow sea. As a source of acoustic waves, underwater disturbances generated by ships were adopted. A specific feature of the propagation of acoustic waves in shallow water is the proximity of boundaries of the limiting media characterised by different impedance properties, which affects the acoustic field coming from a source situated in the water layer “ deformed”...
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The influence of road surface unevenness on tyre rolling resistance
PublicationThe geometric characteristics of road surface substantially affect the interaction between tyre and road. Depending on pavement texture wavelength, the texture chiefly affects tyre/road friction, rolling resistance, interior and exterior noise, tyre wear, and ride comfort. The article presents results of investigations on the influence of road surface unevenness on the rolling resistance of passenger car and truck tyres. The tests...
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Matura 2010 - Matematyka (cz. 2)
PublicationArtykuł omawia pewne czynniki, które wpłynęły na podjęcie decyzji o powrocie matematyki jako przedmiotu obowiązkowego na maturze oraz wskazuje na potrzeby zmian w systemie kształcenia z tego przedmiotu na uczelniach technicznych. Z pewnością można twierdzić, że matematyka jest nauką ścisłą opartą na dedukcji, czyli metodzie dochodzenia do wniosków z uwzględnieniem praw logiki w sposób absolutnie pewny. Dlatego jest to przedmiot...
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Badania eksperymentalne i numeryczne zachowania się zbiorników stalowych poddanych wstrząsom górniczym i sejsmicznym
PublicationW niniejszej dysertacji opisano wyniki kompleksowych badań zachowania się zbiorników stalowych poddanych wstrząsom górniczym i umiarkowanym trzęsieniom ziemi. Badania prowadzono dla dwóch zbiorników rzeczywistych zlokalizowanych na terenie Polski. W pierwszym etapie badań przeprowadzono badania eksperymentalne na specjalnym stanowisku laboratoryjnym dla modeli doświadczalnych zbiorników. Badania prowadzono dla różnego poziomu wypełnienia...
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Application of gas chromatography-olfactometry (GC-O) in analysis and quality assessment of alcoholic beverages - a review
PublicationW ostatnich latach prowadzone są intensywne badania nad aktywnością sensoryczną poszczególnych składników zapachów napojów alkoholowych i nad zależnościami pomiędzy zapachem, a składem chemicznym lotnej frakcji tych produktów z wykorzystaniem techniki chromatografii gazowej z detekcją olfaktometryczną (GC-O). GC-O jest techniką wykorzystującą możliwość oceny sensorycznej eluatu z kolumny chromatograficznej, przy czym dla każdego...
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Results of acoustic emission tests of corrosion protection degree of ship steel tanks covered by means of protective coatings (Phase I)
PublicationThis paper presents methods and results of the 1st series of tests of acoustic emission (AE) signals, aimed at assessing degree of corrosion protection of a tank made of hull structural steel, protected by means of a protective coating combined from polyurethane layer and concrete filler. The tests were carried outin compliance with a method specially elaborated for application to the work in question. In the method were used requirements...
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Architektura przyszłości – przekraczanie granic poprzez interfejsy
PublicationArchitektura przyszłości rozpatrywana jest w kontekście rozwoju technologii cyfrowych, które umożliwiają nadawanie obiektom architektonicznym cech interfejsów. Przekraczanie granic dotyczy więc nadawania architekturze nowych funkcji - funkcjonalności zapożyczonych ze świata wirtualnego, emisji informacji oraz interakcji. W tym ujęciu „interfejs architektoniczny” stanowi płaszczyznę komunikacji pomiędzy obiektem architektonicznym...
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Analiza układów kinematycznych docierania powierzchni płaskich w aspekcie równomierności zużycia tarczy docierającej
PublicationPrzedmiotem rozprawy doktorskiej jest analiza układów kinematycznych docierania jednotarczowego w aspekcie równomierności zużycia tarczy docierającej. W pierwszej części pracy szczegółowo opisano mechanizm docierania powierzchni płaskich oraz określono wpływ poszczególnych parametrów procesu na dokładność obróbki. Przeanalizowano dotychczas opracowane modele zużycia docieraka oraz opisano istniejące rozwiązania konstrukcyjne układów...
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Metody intensyfikacji wymiany ciepła "po stronie płaszcza" w kompaktowym wężownicowym wymienniku ciepła
PublicationZe względu na rosnącą populację i zwiększające się zanieczyszczenie środowiska naturalnego coraz aktualniejsza staje się tematyka wysokosprawnych wymienników ciepła . Elementy te mają duże znaczenie dla systemów energetycznych, instalacji chłodniczych i wentylacyjnych oraz inżynierii spożywczej i chemicznej . Jedną z częściej spotykanych konstrukcji jest wężownicowy aparat cieplny . Ten typ aparatu cieplnego został opracowany w...