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Search results for: CYLINDRICAL GUIDES
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Pre-swirl energy saving device in marine application
PublicationThis paper covers topics of energy saving device (ESD) with application to marine propulsors. The form of ESD, considered in this paper, consists of fixed lifting foils mounted in front of the screw propeller (the pre-swirl stator/guide vanes). An algorithm for designing propulsion systems, consisting of guide vanes and screw propeller, is presented. The proposed method relies on hybrid lifting line (guide vanes)-lifting surface...
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BEARING SYSTEMS OF WIND TURBINES – MAINTENANCE PROBLEMS
PublicationW praktyce eksploatacyjnej turbin wiatrowych o tradycyjnej konstrukcji (przekładniowych) obserwowana jest duża awaryjność przekładni, a zwłaszcza łożysk tocznych szybkoobrotowych wałów przekładni. W Polsce na zlecenie właściciela dużej farmy wiatrowej, firmy Energa Wytwarzanie S.A., Politechnika Gdańska we współpracy z Politechniką Poznańską i Akademią Górniczo Hutniczą podjęły badania mające na celu diagnozowanie przyczyn uszkodzeń...
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Experimental research of the stability of steel cylindricalshell subjected to circumferential compression
PublicationAt the Department of Metal Structures Gdańsk University of Technology, experiments have been performed on the stability of shell of steel cylindrical models. The experiments have been carried on a test bench built at the Department. The design based on other test benches which were created in the past by other scientists, where modernized by the courtesy of companies that offer modern solutions. The test bench enables to generate...
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A method to assess transverse vibration energy of ship propeller shaft for diagnostic purposes
PublicationThe article discusses a key problem of ship propulsion system vibration diagnostics, which concerns assessing this part of mechanical energy transmitted from the main engine to the ship propeller which is dissipated due to propeller shaft vibration. A simplified calculation model is proposed which allows the total energy of the generated torsional vibration to be assessed from the shaft deflection amplitude measured at the mind-span...
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High Performance Tubular Heat Exchanger with Minijet Heat Transfer Enhancement
PublicationIn the paper, the original cylindrical heat exchanger with minijets (MJHE) was introduced. The systematic experimental analysis of the prototype heat exchanger was described with special attention paid to such parameters as the heat transfer effectiveness, heat transfer rates, overall heat transfer coefficients, and pressure drop. The heat transfer coefficients were determined based on Wilson plot method, the most suitable approach...
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A Formal Approach to Model the Expansion of Natural Events: The Case of Infectious Diseases
PublicationA formal approach to modeling the expansion of natural events is presented in this paper. Since the mathematical, statistical or computational methods used are not relevant for development, a modular framework is carried out that guides from the external observation down to the innermost level of the variables that have to appear in the future mathematical-computational formalization. As an example we analyze the expansion of Covid-19....
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Extension management of a knowledge base migration process to IPv6
PublicationThere are many reasons to deploy IPv6 protocol with IPv4 address space depletion being the most indisputable. Unfortunately, migration to IPv6 protocol seems slower than anticipated. To improve pace of the IPv6 deployment, authors of the article developed the two applications that supports the migration process. Their main purpose is to help less experienced network administrators facilitate the migration process with a particular...
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Wykładnicze równanie Arrheniusa jako funkcja dojrzałości twardniejącego betonu
PublicationPoprawne określenie funkcji dojrzałości dla mieszanki betonowej warunkuje powodzenie szacowania wytrzymałości na ściskanie na bazie pomiarów temperatury in situ. W artykule omówiono zastosowanie równania Arrheniusa do opisu funkcji dojrzewania twardniejącego betonu. Szczególną uwagę zwrócono na zależności szybkości zachodzenia reakcji w odmiennych warunkach temperaturowych. Przedstawiono wyniki własnych badań na kostkach zaprawy...
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Global Surrogate Modeling by Neural Network-Based Model Uncertainty
PublicationThis work proposes a novel adaptive global surrogate modeling algorithm which uses two neural networks, one for prediction and the other for the model uncertainty. Specifically, the algorithm proceeds in cycles and adaptively enhances the neural network-based surrogate model by selecting the next sampling points guided by an auxiliary neural network approximation of the spatial error. The proposed algorithm is tested numerically...
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Analysis of MArkers of Exposure to Constituents of Environmental Tobacco Smoke (ETS)
PublicationTobacco smoke is a complex mixture of more than 4000 chemical compounds, many of which are harmful to human health. These compounds belong to various chemical classes, including amides, imides, lactams, carboxylic acids, aldehydes, ketones, alcohols, phenols, amines, hydrocarbons, ethers, and inorganic compounds. There are three types of tobacco smoke streams: the mainstream, the sidestream, and environmental tobacco smoke (ETS)....
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Formulation of Time-Fractional Electrodynamics Based on Riemann-Silberstein Vector
PublicationIn this paper, the formulation of time-fractional (TF) electrodynamics is derived based on the Riemann-Silberstein (RS) vector. With the use of this vector and fractional-order derivatives, one can write TF Maxwell’s equations in a compact form, which allows for modelling of energy dissipation and dynamics of electromagnetic systems with memory. Therefore, we formulate TF Maxwell’s equations using the RS vector and analyse their...
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Non-Salient Brushless Synchronous Generator Main Exciter Design for More Electric Aircraft
PublicationThis paper presents a prototype of high speed brushless synchronous generators (BSG) design for the application in autonomous electric power generation systems (e.g., airplane power grid). Commonly used salient pole field of the main generator part of BSG was replaced with a prototype non-salient pole field. The main objective of the research is an investigation into the advantages and disadvantages of a cylindrical field of the...
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Wpływ imperfekcji geometrycznych na bezpieczeństwo montażu i naprawy zbiorników cylindrycznych metoda podbudowy
PublicationW pracy zajęto się wyznaczeniem nośności granicznej zbiorników stalowych o osi pionowej montowanych lub naprawianych z zastosowaniem hydraulicznego systemu podnoszenia konstrukcji. Podniesiony zbiornik jest szczególnie narażony na utratę stateczności, a obciążenie wiatrem utrudnia prowadzenie prac. Jakiekolwiek deformacje blach, szczególnie w pobliżu zamocowań podnośników mogą w znacznym stopniu obniżyć obciążenie krytyczne konstrukcji....
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Neural Oscillation During Mental Imagery in Sport: An Olympic Sailor Case Study
PublicationThe purpose of the current study was to examine the cortical correlates of imagery depending on instructional modality (guided vs. self-produced) using various sports-related scripts. According to the expert-performance approach, we took an idiosyncratic perspective analyzing the mental imagery of an experienced two-time Olympic athlete to verify whether different instructional modalities of imagery (i.e., guided vs. self-produced)...
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Infographics in Educational Settings: A Literature Review
PublicationInfographics are visual representations of data that utilize various graphic elements, including pie charts, bar graphs, line graphs, and histograms. Educators and designers can maximize the potential of infographics as powerful educational tools by carefully addressing challenges and capitalizing on emerging technologies. However, current education systems showcase the need for development guidelines and the best practices targeted...
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Experimental study on static and dynamic properties of polymer mass
PublicationA new method of repairing damaged structures by filling the cracks with a specially prepared polymer mass has been recently proposed. This new and innovative technique, known as the Flexible Joint Method (FJM), is mainly dedicated to masonries and historical objects, where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure. The aim of the...
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Diagnosis of Damage in a Steel Tank Model by Shaking Table Harmonic Tests
PublicationThe aim of the present paper is to show the results of the shaking table experimental study concerning the diagnosis of damage in a model of cylindrical steel tank with self-supported roof which is filled with liquid. During the tests, the base of the structure was excited under the harmonic loading with variable frequency. The tests were repeated for different stages of damage, which was introduced in the model by easing the bolts...
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ARRAY OF MINIJETS – THERMAL AND HYDRAULIC PHENOMENA IN BOUNDARY LAYER
PublicationPresented work considers flow and thermal phenomena occurring in the system consisting of minijets array and heated with constant heat flux surface. Numerical analyses, based on the mass, momentum and energy conservation laws, were conducted. Focus was placed on the proper model construction, in which turbulence and boundary layer modelling was crucial. Calculations were done for various mass flow rates. The main calculations were...
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Full scattering profile of circular optical phantoms mimicking biological tissue
PublicationHuman tissue is one of the most complex optical media since it is turbid and nonhomogeneous. In our poster, we suggest a new type of skin phantom and an optical method for sensing physiological tissue condition, basing on the collection of the ejected light at all exit angles, to receive the full scattering profile. Conducted experiments were carried out on an unique set-up for noninvasive encircled measurement. Set-up consisted...
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Experimental investigation of two-phase thermosyphon heat exchanger charged with acetone
PublicationThis 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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A Conformal Circularly Polarized Series-Fed Microstrip Antenna Array Design
PublicationA conformal circularly polarized series-fed microstrip array design for broadside radiation is presented. The array aperture under design is conformal to a cylindrical surface of a given radius. The approach we present primarily addresses focusing of the circularly polarized major lobe of the conformal array by proper dimensioning of the aperture spacings. The proposed analytical models yield the values of the element spacings...
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Buckling of simplified models of silo with corrugated walls and vertical stiffeners
PublicationThe paper deals with buckling of cylindrical silos composed of corrugated sheets and vertical stiffeners (columns). Comprehensive finite element analyses were carried out for a perfect silo by means of a linear buckling approach. Corrugated walls were simulated as an equivalent orthotropic shell and vertical thin-walled columns as beam elements. Calculations for perfect silos with different numbers of columns made it possible to...
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Ewa Bieńkowska Culture Films, Texts & Quizes
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Skin Conductance Level (SCL) data collected during mental training of group of 30 athletes
Open Research DataThe dataset contain raw Skin Conductance Level (SCL) data, collected at a frequency of 40 Hz and expressed in units of microsiemens (μS), during mental training of group of 30 athletes, under the project "Psychophysiology of guided and self-produced imagery in sport".
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Determination of Flavonoids, Tannins and Ellagic acid in leaves fromRubus L. species
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Impaired baroreflex sensitivity as a potential marker of cardiovascular risk in hypertension
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On-line Search in Two-Dimensional Environment
PublicationWe consider the following on-line pursuit-evasion problem. A team of mobile agents called searchers starts at an arbitrary node of an unknown network. Their goal is to execute a search strategy that guarantees capturing a fast and invisible intruder regardless of its movements using as few searchers as possible. We require that the strategy is connected and monotone, that is, at each point of the execution the part of the graph...
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Computational analysis of power-law fluids for convective heat transfer in permeable enclosures using Darcy effects
PublicationNatural convection is a complex environmental phenomenon that typically occurs in engineering settings in porous structures. Shear thinning or shear thickening fuids are characteristics of power-law fuids, which are non-Newtonian in nature and fnd wide-ranging uses in various industrial processes. Non-Newtonian fuid fow in porous media is a difcult problem with important consequences for energy systems and heat transfer. In this...
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Jaroslaw Spychala dr
PeopleOprócz bardzo dobrego wykształcenia osoba posiada również wieloletnie doświadczenie zawodowe, które jest poświadczeniem tego, że potrafi wykorzystać swoją wiedzę teoretyczną w praktycznych działaniach. Doświadczenie zawodowe jest bardzo bogate i rozbudowane. Ze względu na nabyte całkiem nowe umiejętności zwiększa się atrakcyjność doświadczonego pracownika. Są to między innymi kreatywne myślenie, zorientowanie na cel, odporność...
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The Development of a Combined Method to Quickly Assess Ship Speed and Fuel Consumption at Different Powertrain Load and Sea Conditions
PublicationDecision support systems (DSS) recently have been increasingly in use during ships operation. They require realistic input data regarding different aspects of navigation. To address the optimal weather routing of a ship, which is one of the most promising field of DSS application, it is necessary to accurately predict an actually attainable speed of a ship and corresponding fuel consumption at given loading conditions and predicted...
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Towards Improving Optimised Ship Weather Routing
PublicationThe aim of the paper is to outline a project focusing on the development of a new type of ship weather routing solution with improved uncertainty handling, through better estimation of ship performance and responses to sea conditions. Ensemble forecasting is considered to take into account the uncertainty levels that are typical of operations in a stochastic environment. Increased accuracy of weather prediction is achieved through...
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Monitoring of breast tissue thermo-ablation by means of impedance measurements
PublicationW pracy przedstawiono rozważania dotyczące monitorowania jakości termoablacji zmian nowotworowych w piersi przy pomocy pomiarów impedancyjnych. Pokazano prototypowe konstrukcje sond do termoablacji jak również zaprezentowano wyniki symulacji i pierwszych eksperymentów. A usefulness of a developed probe combining power delivery to ablated breast tumour and simultaneous impedance measurements is discussed in the paper. It consists...
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Modelling of the Heat Flux Density Distribution for Laser Beam Welding
PublicationGreat interest of the laser beam welding in industry is a new theoretical task, making planning the welding procedure specification and the quality control of welded joints easier. Estimating and calculating the dimensions of a weld pool and temperature distribution near weld mainly concern heat source modelling. In the presented work calculations of welding pool shape and thermal field for cylindrical-powered-normally model of...
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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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Buckling Analysis of Cold Formed Silo Column
PublicationThe paper is devoted to stability analysis of different models of steel cold formed silo column. The steel cylindrical silos are often composed of corrugated walls and vertical open-sectional columns uniformly placed along the silo circumference. Both the whole 3D silo, a simplified model consisting of one column with a part of the silo walls, and a single column resting on elastic foundation provided by the silo walls were analyzed....
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Lighting requirements for pedestrian crossings - positive contrast
PublicationFor many years now in Poland there has been a large number of road accidents at pedestrian crossings during night periods [5, 11]. One of the technical solutions that can improve this condition is the use of proper lighting for pedestrian crossings. The designated pedestrian crossing should be visible in different weather conditions and at different times of the day. In case of night vision restrictions use artificial lighting...
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Rafał Leszczyna dr hab. inż.
PeopleDr hab. Rafal Leszczyna is an associate professor at Gdansk University of Technology, Faculty of Management and Economics. He holds the M.Sc. degrees of Computer Science and Business Management. In December, 2006 he earned a Ph.D. in Computer Science, specialisation - Computer Security at the Faculty of Electronics, Telecommunications and Informatics of Gdansk University of Technology. Between 2004 and 2008 he worked in the European...
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Detection of apple in orange juice using ultra-fast gas chromatography
PublicationThe determination of authenticity is an increasingly important issue for food quality and safety. The use of an electronic nose based on ultra-fast gas chromatography technique ensures rapid analysis of the volatile compounds from food products. Due to the fact that this technique enables chemical profiling of agricultural products, it can be an effective tool for authentication when combined with chemometrics. In this article...
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Chemistry and Nanochemistry 2023
e-Learning CoursesWe start from General Chemistry, including: calculus in chemistry, bonds, balancing the chemical reactions, redox reactions, electrochemistry, pH, acids, bases, salts, oxides, organic molecules, and many informations about synthesis, analysis and applications in nanochemistry.
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Divulging the anti-acetylcholinesterase activity of Colletotrichum lentis strain KU1 extract as sustainable AChE active site inhibitors
PublicationAlzheimer’s disease (AD), also called senile dementia is a neurodegenerative disease seen commonly in the elderly and is characterised by the formation of β-amyloid plaques and neurofbrillary tangles (NFT). Though a complete understanding of the disease is lacking, recent studies showed the role of the enzyme acetylcholinesterase (AChE) in pathogenesis. Finding new lead compounds from natural sources has always been a quest for...
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Piotr Dworakowski dr
PeoplePiotr Dworakowski received the MSc degree and PhD degree with distinction in electrical engineering from Gdansk University of Technology, Poland, in 2007 and 2020 respectively. From 2008 to 2013 he was working in Alstom Transport, Tarbes, France on traction drives control. Since 2014 he has been a Power Converters Team Leader in SuperGrid Institute, Lyon, France. His research interests include high efficiency power converters for...
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Membrane distillation assisting food production processes of thermally sensitive food liquid items: a review
PublicationPhysical separation technologies have become important tool for processing in the current food manufacturing industries, especially for the products containing bioactive compounds thanks to their health benefits in costumers. As for the processing of bioactive food ingredients implies the implementation of integrated systems oriented to their separation, fractionation, and recovery. In this field, membrane distillation (MD), which...
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Joachim Gudel prof. dr hab.
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Karol Gudek inżynier
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Michał Wróbel dr inż.
PeopleMichał Wróbel, Assistant Professor of Gdańsk University of Technology, computer scientist, a specialist in software engineering. I graduated from the Faculty of Electronics Technical University of Gdansk in 2002 with a degree in Computer Science, with specialization in Software Engineering and Databases. Until 2006 I worked as system administrator in several companies, including CI TASK. Since 2006 I have been working at the Faculty...
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Application of atmospheric pressure microwave plasma source for hydrogen production from ethanol
PublicationIn contrast to conventional technologies of hydrogen production like water electrolysis or coal gasification we propose a method based on the atmospheric pressure microwave plasma. In this paper we present results of the experimental investigations of the hydrogen production from ethanol in the atmospheric pressure plasma generated in waveguidesupplied cylindrical type nozzleless microwave (915 MHz and 2.45 GHz) plasma source (MPS)....
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Pressure drop of HFE7000 and HFE7100 during flow condensation in minichannels
PublicationAttention is focused on the issues of flow resistance and pressure drop of perspective refrigeration fluids during condensation in the two-phase flow in minichannels. The case of the flow through a cylindrical single channel of 2.3 mm inner diameter was carefully analyzed. Pressure drop tests have been performed in diabatic flow conditions. The effect of heat flux, mass flux, vapour quality and saturation temperature on the two-phase...
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Buried Object Characterization Using Ground Penetrating Radar Assisted by Data-Driven Surrogate-Models
PublicationThis work addresses artificial-intelligence-based buried object characterization using 3-D full-wave electromagnetic simulations of a ground penetrating radar (GPR). The task is to characterize cylindrical shape, perfectly electric conductor (PEC) object buried in various dispersive soil media, and in different positions. The main contributions of this work are (i) development of a fast and accurate data driven surrogate modeling...
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Thermal and hydraulic phenomena in boundary layer of minijets impingement on curved surfaces
PublicationPresented work considers flow and thermal phenomena occurring during the single minijet impingement on curved surfaces, heated with a constant heat flux, as well as the array of minijets. Numerical analyses, based on the mass, momentum and energy conservation laws, were conducted, regarding single phase and two-phase simulations. Focus was placed on the proper model construction, in which turbulence and boundary layer modeling...
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EM-driven topology evolution for bandwidth enhancement of hybrid quadrature patch couplers
PublicationA broad operational bandwidth is one of the key performance figures of hybrid patch couplers. Due to the lack of systematic design procedures, bandwidth enhancement is normally obtained through manual modifications of the structure geometry. In this work, an optimization-based topology evolution for EM-driven design of patch couplers with enhanced bandwidth has been proposed. The method exploits a novel spline-based EM model where...