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Wyniki wyszukiwania dla: load-bearing structure
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Report no WOiO/II/67/2015 - Expertise about load capacity of twistlock foundation and sliding foundation
PublikacjaCustomer delivered to Laboratory 17 elements - twist lock foundations and sliding lock foundations (ship equipment for container lashing). Elements were selected from production series. Each element was loaded for braking load. After test visual inspection had been performed. The expertise contains: description of tested elements, test assumptions, test stand, results and conclusions
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The Method of Multi-criteria Analysis to Support the Decision on Load or Micro-generation Connection to a Low- or Medium-voltage Power Grid
PublikacjaThis paper presents a method that supports the decision in terms on selecting the best option of a load connection to a low- or medium-voltage power distribution grid, and of a micro-generation source connection to a low-voltage grid. The method is based on the search for the option with the lowest aggregate assessment measure, which is the weighted average of partial assessment measures determined for each of eight considered...
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A CONCEPT OF DETERMINING THE RELATION BETWEEN LOAD AND WEAR OF TRIBOLOGICAL SYSTEMS OF SHIP MAIN SELF-IGNITION ENGINES BY USING PROBABILISTIC APPROACH PROBABILISTIC APPROACH
PublikacjaThis paper presents a proposal of simultaneous consideration of load and wear associated with it , of tribological systems of ship main engines (intended for ship propulsion) . Based on results of investigations it was assumed that both the load Q (i.e. a cause of wear ) and the wear Z (i.e. an effect of load occurrence) considered in a given time t(0 ≤ t ≤ t) are random variables Qt and Zt, respectively. There was characterized...
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Speed Observer Structure of Induction Machine Based on Sliding Super-Twisting and Backstepping Techniques
PublikacjaThis paper presents an analysis of the two speed observer structures which are based on the backstepping and sliding super twisting approach. The observer stabilizing functions result from the Lyapunov theorem. To obtain the observer tuning gains the observer structure is linearized near the equilibrium point. The rotor angular speed is obtained from non-adaptive dependence. In the sensorless control system structure the classical...
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Parametric analysis of Istanbul's Ring Road viaduct for three levels of seismic load
PublikacjaThe paper presents a numerical analysis of the Istanbul's ring road viaduct that is currently under construction within the Northern Marmara Highway project. The structure, due to its location on seismic prone areas is exposed to seismic loads of different magnitude and different return periods. The study is fo-cused on concrete bridge supports that are design to work in nonlinear range. The study, conducted in SOFISTIK environment,...
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Janusz Kozak prof. dr hab. inż.
OsobyDr hab. inż. Janusz Kozak Dziekan Wydziału Oceanotechniki i Okrętownictwa Politechniki Gdańskiej Urodzony: 04.07.1953 w Pucku Absolwent Technikum Budowy Okrętów „Conradinum” w Gdańsku, 1973. Absolwent Instytutu Okrętowego PG, 1978. Po ukończeniu studiów praca w Stoczni Gdynia, a od roku 1980 w Katedrze Technologii Okrętów Instytutu Okrętowego a później Wydziału Oceanotechniki i Okrętownictwa Politechniki Gdańskiej kolejno na...
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Simplified approach to assess the dynamic response of a container ship subjected to bow slamming load
PublikacjaSimplified approach to assess the dynamic response of a container ship subjected to the bow slamming load, resulting in a transient vibratory response, typically called a 'whip-ping', is presented. The accurate numerical modelling is very complex and involves cou-pling of the hydrodynamic and structural solution at every time step, leading to huge com-putational and workload cost. Thus, the one-way coupling methodology is adopted,...
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Experimental research on water lubricated three layer sliding bearing with lubrication grooves in the upper part of the bush and its comparison with a rubber bearing
Publikacjacomposite. Eachofitslayershasanimportantfunction.Speciallypreparedslidingsurfaceensures minimum resistance.Followingrunning-initssmoothnessbecomesveryhighandthebearingmay continue workingunder fluid lubricationregime.NBRlayerensuresbearingelasticity,goodvibration damping propertiesandinsusceptibilitytoshaftaxismisalignment.Theexternalbrasslayermakes fitting thebearingeasier. Experiment resultsoftheconductedresearchwerecomparedwiththoseforarubberbearingof similar...
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Numerical analysis of mechanical properties of an infill structure used in 3D printings
PublikacjaThe paper presents results of a numerical analysis focused on an identification of mechanical properties of an element created by using Fused Deposition Modelling additive manufacturing technique (FDM). There is presented a description of technology of the 3D printing, numerical model created by using the finite element method (FEM), as well as some problems referred to estimation of the mechanical properties of the printout. The...
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Synthesis and Characterization of Poly(zwitterionic) Structures for Energy Conversion and Storage
PublikacjaZwitterions are unique class of molecules that possess two functional groups bearing electric charges, one positive and second negative. This setup results in peculiar properties such as high water retention and anti-fouling capability. Therefore, zwitterionic coatings and gels are commonly applied in e.g. biosensing and bioelectronic devices. Despite those applications, there are other perspectives for zwitterionic materials....
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Yerba Mate - A Long but Current History
PublikacjaBearing in mind the growing interest in Yerba Mate, a comprehensive study has been prepared containing the most important aspects and possibilities of its use. The introduction of the work contains the species characteristics of Yerba Mate, as well as information about the origin and places of cultivation. The next part focuses on the analysis of the composition, pointing to purine alkaloids, polyphenols, saponins, and minerals...
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Thermal and technological aspects of double face grinding of Al2O3 ceramic materials
PublikacjaDouble face grinding with planetary kinematics is a process to manufacture workpieces with plan parallel functional surfaces, such as bearing rings or sealing shims. In order to increase the economic efficiency of this process, it has to be advanced permanently. The temperature in the contact zone of most grinding processes has a huge influence on the process efficiency and the workpiece qualities. In contrast to most grinding...
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Digital Gaps and Economic Inequalities in MENA Countries: An Empirical Investigation
PublikacjaThis research contributes to the present state of the art by examining changes in cross-country inequalities in digital technologies deployment and economic performance. Our empirical target builds on the hypothesis that rapid global diffusion of digital technologies unequivocally leads to gradual eradication of cross-country digital gaps and cross-country inequalities in terms of deployment of ICT; the technology convergence occurs....
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Parametric analysis of Istanbul's Ring Road viaduct for three levels of seismic load
PublikacjaThe paper presents a parametric analysis of the Istanbul's ring road viaduct that is currently under construction within the Northern Marmara Highway project. The structure, due to its location on seismic prone areas is exposed to seismic loads of different strengths and different return periods. The study is focused on concrete bridge supports that are design to work in nonlinear range. The parametric study, conducted in MATLAB...
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Numerical modelling and analysis of steel specimens subjected to marine immersed corrosion and tensile load
PublikacjaThe present study develops numerical models to analyse the behaviour of steel specimens subjected to marine immersed corrosion degradation and tensile load. The finite element method with the use of the explicit dynamic solver LS-DYNA, satisfying the quasi-static conditions, is employed. Two numerical models are developed, where in the first one, the scans of surfaces gathered from corroded plate specimens are implemented directly...
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Experimental tests of water lubricated marine rubber bearing
PublikacjaW referacie przedstawiono stosowane obecnie rodzaje łożysk gumowych smarowanych wodą. Omówiono ich zalety i wady.W drugiej części pracy przedstawiono wyniki badań eksperymantalnych typowego okrętowego łożyska gumowego. Uzyskane rezultaty porównano z wynikami badań łożysk z polimerową panwią.
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Influence of Collar Deformations on Hydrodynamic Thrust Bearing Performance
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Estimation of pile bearing capacity by dynamic and static tests
PublikacjaBadania dynamiczne, szczególnie dla pali wbijanych, w budownictwie hydrotechnicznym stają się coraz bardziej popularne. Badania, poparte formalnie zapisami zawartymi w Eurokodzie 7, wykorzystywane w badaniach ''na wodzie'' i ''na lądzie'' są szybkie i ekonomiczne. Przedstawiono serię badań dla gruntów uwarstwionych dla pali prefabrykowanych żelbetowych, wbijanych stalowych pali rurowych oraz pali Vibro-Fundex. Badania dynamiczne...
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Mechanism of the fatigue cracks development in bearing slide layer
PublikacjaNa podstawie literatury przedstawiono wybrane problemy dotyczące powiązania wytrzymałości zmęczeniowej łożysk ślizgowych ze strukturą i charakterystyką materiału tworzącego warstwę ślizgową panwi.W szczególności analizowano mechanizm inicjacji i propagacji pęknięć zmęczeniowych jako zależną nie tylko od wzorca obciążenia dynamicznego, lecz również od geometrii i struktury warstwy ślizgowej.Wyróżniono dwa typy pęknięć: strukturalne...
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Bearing errors passive sonar stationary target location
PublikacjaPrzedstawiono metodę wyznaczania współrzędnych nieruchomego celu na podstawie namiarów wykonywanych w sonarze pasywnym. Określono wymagania odnośnie ruchu sonaru, przy których błędy wyznaczania współrzędnych są minimalne. Podano zależności umożliwiające analityczne wyznaczanie błędów współrzędnych. Poprawność wyników analizy potwierdzono eksperymentami numerycznymi.
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Bearing capacity factors of sand assessed by model tests
PublikacjaPrzedstawiono wyniki własnych badań modelowych fundamentów bezpośrednich posadowionych na trzech rodzajach piasków, wykonane w warunkach płaskiego stanu odkształcenia. Przeanalizowano wpływ tarcia gruntu o ściany boczne stanowiska badawczego, wpływ efektu skali oraz powtarzalności wyników na nośność badanych fundamentów bezpośrednich. Zastosowano specjalną własną metodykę wykonywania badań modelowych eliminującą wymieniony wpływ...
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Testing of fatigue strength limit of slide bearing materials
PublikacjaPrzedstawiono wyniki badań wytrzymałości zmęczeniowej wybranych trójwarstwowych łożysk cienkościennych. Zaprezentowano zdjęcia typowych pęknięć zmęczeniowych warstwy stopu łożyskowego. Obliczono i oceniono krytyczne wartości naprężeń stycznych warstwy ślizgowej.
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Hydrodynamic journal bearing - ''Y'' particularly for steam turbines.
PublikacjaW artykule przedstawiono koncepcję i zasadę działania nowego, ślizgoweo łożyska poprzecznego typu ''Y''. Przedstawiono wady i zalety nowego rozwiązania. Porównano charakterystyki dynamiczne i statyczne klasycznego łożyska cytrynowego (soczewkowego) z nowym łożyskiem ''Y''.Podano przykładowe wdrożenia i ich efekty.
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Non-linear model of high damping rubber bearing.
PublikacjaCelem artykułu jest analiza modelu łożyska wykonanego z wysokotłumiącej gumy, które wykorzystywane są do posadowienia konstrukcji budowlanych na terenach sejsmicznych. Model umożliwia numeryczną symulację pracy urządzenia pod zadanym obciążeniem i w danych warunkach termiczno-wilgotnościowych. Wyniki analizy pokazują, iż proponowany model umożliwia symulację zachowania się łożyska w szerokim zakresie odkształceń.
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Effect of preconsolidation on pile bearing capacity in model tests
PublikacjaBadanie wpływu prekonsolidacji gruntu w badaniach modelowych w komorze kalibracyjnej. Zagęszczone piaski kwarcowe poddano prekonsolidacji przy OCR nie większym od 7. Analiza współczynnika parcia spoczynkowego gruntu. Wpływ wskaźnika prekonsolidacji na nośność podstawy i pobocznicy pali oraz zmiany naprężeń wokół modelu i odkształcenia objętościowe masywu gruntowego.
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A stochastic approach to the problem of bearing capacity by the method of characteristics
PublikacjaW pracy omówiono zagadnienie nośności granicznej podłoża o własnościach losowych, przy obciążeniu od spoczywającego na nim fundamentu. Zaproponowano stochastyczną modyfikację metody charakterystyk bazującej na metodzie różnic skończonych. Analizowano zagadnienia związane z dyskretyzacją losowego ośrodka gruntowego, symulacją pola losowego oraz ze zbieżnością i stabilnością rozwiązania. Przedstawione podejście umożliwiło uwzględnienie...
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Chained machine learning model for predicting load capacity and ductility of steel fiber–reinforced concrete beams
PublikacjaOne of the main issues associated with steel fiber–reinforced concrete (SFRC) beams is the ability to anticipate their flexural response. With a comprehensive grid search, several stacked models (i.e., chained, parallel) consisting of various machine learning (ML) algorithms and artificial neural networks (ANNs) were developed to predict the flexural response of SFRC beams. The flexural performance of SFRC beams under bending was...
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Structure and thermal expansion of liquid bismuth
PublikacjaExperimental structural data for liquid Bi were used for estimation of the main structure parameters as well as the thermal expansion coefficient both in supercooled and superheated temperature ranges. It was shown that the equilibrium melt had a positive thermal expansion coefficient within a temperature range upon melting and a negative one at higher temperatures. The former was related to structure changes upon melting, whereas...
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A New Method of the Load Compensation Use During Creation of Post Blackout Start-up Path in Power System
PublikacjaIn the paper a new method of effective use of load compensation during creation of post blackout start-up path is proposed. Theoretical assumptions and simulation results of an investigation are presented. An experiment performed in the Polish Power System is also described. This experiment proved that the method proposed by the authors is advisable. The method may be utilized by power system operators for power system restoration...
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Smooth least absolute deviation estimators for outlier-proof identification
PublikacjaThe paper proposes to identify the parameters of linear dynamic models based on the original implementation of least absolute deviation estimators. It is known that the object estimation procedures synthesized in the sense of the least sum of absolute prediction errors are particularly resistant to occasional outliers and gaps in the analyzed system data series, while the classical least squares procedure unfortunately becomes...
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Reactivity of Diimido Complexes of Molybdenum and Tungsten towards Lithium Derivatives of Diphosphanes and Triphosphanes
PublikacjaThe reaction of R2P–P(SiMe3)Li (R = tBu, iPr) with the diimido molybdenum complex [(ArN)2MoCl2·dme] (Ar = 2,6-iPr2C6H3; dme = 1,2-dimethoxyethane) yielded the side-oncoordinated phosphanylphosphinidene anionic complexes [(2,6-iPr2C6H3N)2Mo(Cl)(η2-P=PR2)]– (7Mo, 8Mo). The thermal decomposition of [(2,6-iPr2C6H3N)2M(Cl)(η2-P=PR2)]–[M = Mo (7Mo), W (8W)] to [(2,6-iPr2C6H3N)2M(Cl)(1,2-η-tBu2P=P–PtBu2)] [M = Mo (3Mo), W (3W)] was investigated...
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Study on some of the strength properties of soft clay stabilized with plastic waste strips
PublikacjaIt is well known that if plastic wastes are not well managed, it has a negative impact on the environment as well as on human health. In this study, recycling plastic waste in form of strips for stabilizing weak subgrade soil is proposed. For this purpose, a weak clay soil sample was mixed with 0.2%, 0.3%, and 0.4% of plastic strips by weight of soil, and the experimental results were compared to the control soil sample with 0%...
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The Experimental Determination of Bearings Dynamic Coefficients in a Wide Range of Rotational Speeds, Taking into Account the Resonance and Hydrodynamic Instability
PublikacjaMethods for the experimental determination of dynamic coefficients are commonly used for the analysis of various types of bearings, including hydrodynamic, aerodynamic and foil bearings. There are currently several algorithms that allow estimating bearing dynamic coefficients. Such algorithms usually use various excitation techniques applied to rotor–bearings systems. So far only a small number of scientific publications show how...
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Axial-Flux Permanent-Magnet Dual-Rotor Generator for a Counter-Rotating Wind Turbine
PublikacjaCoaxial counter-rotating propellers have been widely applied in ships and helicopters for improving the propulsion efficiency and offsetting system reactive torques. Lately, the counter-rotating concept has been introduced into the wind turbine design. Distributed wind power generation systems often require a novel approach in generator design. In this paper, prototype development of axial-flux generator with a counter-rotating...
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Synthesis, structure, DNA binding and anticancer activity of mixed ligand ruthenium(II) complex
PublikacjaIn order to obtain a potential chemotherapeutic which is not affected on the normal BALB/3T3 cell line, a new arene ruthenium(II) complex {[RuCl(L1)(η6-p-cymene)]PF6}2 · H2O has been synthesized by a direct reaction of precursor, [{(η6-p-cymene)Ru(μ-Cl)}2Cl2], with N,N-chelating ligand (L1 - 2,2′-bis(4,5-dimethylimidazole). The compound has been fully characterized by elemental analysis, X-ray diffraction, IR, UV–Vis and 1H, 13C...
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A probabilistic concept of load assessment of self-ignition engines
PublikacjaPrzedstawiono propozycję probabilistycznej interpretacji obciążenia silników spalinowych o zapłonie samoczynnym. Zaproponowano probabilistyczny opis obciążenia tych silników z uwzględnieniem znanych parametrów (wskaźników) ich pracy. Wykazano, że obciążenie tego rodzaju silników, rozpatrywane w dowolnej chwili, może być uważane za zmienną losową. Zwrócono uwagę, że obciążenie to może być uważane za zmienną losową wielowymiarową....
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Dynamic load tests of piles in non-cohesive soils.
PublikacjaThe results of investigations of various types of piles, the analysis of dynamic tests carried out recently in Poland and the correlations between the results of dynamic and static tests of piles are presented. Przedstawiono wyniki badań nośności różnych rodzajów pali, analizę badań dynamicznych wykonanych w Polsce w ostatnich latach oraz korelacje pomiędzy wynikami badań statycznych i dynamicznych.
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The association between allostatic load and brain: A systematic review
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Numerical analysis of cylindrical shell subjected to explosive load
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Performance of organic coatings upon cyclic mechanical load
PublikacjaA number of engineering structures fail due to the fatigue damage resulting from cyclic mechanical stress. However, as far as organic coatings are concerned this degradation factor remains underestimated. In the paper the authors propose a methodology combining global electrochemical impedance spectroscopy and local atomic force microscopy measurements for evaluation of coating resistance to an impact of repetitive mechanical stress. Typical...
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Analysis of transverse load of saw in wood cutting process
PublikacjaW pracy przedstawiono przyczyny, rodzaje i efekty poprzecznego obciążenia zarówno pojedynczego ostrza, jak również wypadkowego obciążenia piły w procesie przecinania drewna. Dokonano rozkładu całkowitej siły odporowej na składową wolną- i szybkozmienną. Przedstawiono skutki wpływu poszczególnych rodzajów poprzecznego obciążenia pił na dokładność obróbki.
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Shortening and non linear load settlement behaviour of piles.
PublikacjaPrzedstawiono praktyczne wartości współczynnika B do obliczeń skrócenia trzonu pali. W analizie zastosowano metodę funkcji transformacyjnych t-z oraz q-z. Wykorzystano wyniki próbnych obciążeń statycznych pali, w sumie 184 pali próbnych.
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Mechanical properties of Precontraint 1202S coated fabric under biaxial tensile test with different load ratios
PublikacjaThe paper describes a method of laboratory tests necessary for identifying the mechanical properties of polyester coated fabrics named Precontraint 1202S with PVDF surface treatment. Two sets of initial material parameters for dense net model and orthotropic model are specified. Material parameters for Precontraint 1202S coated fabric are specified on the basis of the biaxial tensile tests for different load ratios. In order to...
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Wideband crossover structure with double ring resonators
PublikacjaThe structure of a four-port microstrip crossover is presented. The device is composed of two ring resonators, one circular and one built from meander lines, connected by four straight lines. The equivalent circuit model of the crossover is derived. The structure is designed on thin and flexible substrate to allow it to bend. The possibility of applying the device on curved surfaces is tested experimentally.
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Experimental database of 3D lattice structure scaffolds testing
Dane BadawczeDataset contains results of validation (experimental testing) of 3D lattice scaffolds proposed in the paper "Mathematical approach to design 3D scaffolds for the 3D printable bone implant". There are presented three series of experimental testing for each of seven tested scaffolds:
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Improving Output Performance of the Ultrasonic Multicell Piezoelectric Motor by Development the Multi-Rotor Structure
PublikacjaIn recent years, many researches have been carried out on piezoelectric multi-rotor structures. This paper describes the analysis, development and experimental process of an ultrasonic multi-cell piezoelectric motor using a multi-rotor structure. In this design, three independent cells have been integrated into a mechatronic system. Analytical model and finite element method are used for modal and dynamic analysis of the proposed...
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The Boltzmann sequence-structure channel
PublikacjaWe rigorously study a channel that maps binary sequences to self-avoiding walks in the two-dimensional grid, inspired by a model of protein statistics. This channel, which we also call the Boltzmann sequence-structure channel, is characterized by a Boltzmann/Gibbs distribution with a free parameter corresponding to temperature. In our previous work, we verified experimentally that the channel capacity has a phase transition for...
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Design of Structure of Tension Leg Platform for 6 MW Offshore Wind Turbine Based On Fem Analysis
PublikacjaThe article presents the calculation and design stages of the TLP platform serving as a supporting construction of a 6 MW offshore wind turbine. This platform is designed to anchor at sea at a depth of 60 m. The authors presented the method of parameterization and optimization of the hull geometry. For the two selected geometry variants, the load and motion calculations of the platform subjected to wind, wave and current under...
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Structure and paramagnetism in weakly correlated Y8Co5
PublikacjaWe report the basic physical properties of monoclinic Y8Co5 determined by means of magnetic susceptibility, electrical resistivity, and specific heat measurements. The crystal structure of Y8Co5 is monoclinic (P21/c) with lattice parameters a = 7.0582(6) Å, b = 7.2894(6) Å, c = 24.2234(19) Å, and β = 102.112(6)° as refined by using synchrotron powder x-ray diffraction data. The compound shows temperature independent paramagnetism...
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Surface Structure of Components Created by Stereolitography
PublikacjaStereolithography is an additive rapid prototyping method. This method is based on the principle of solidifying a liquid photopolymer (resin) by laser radiation. Models obtained with this method are characterized by a specific surface structure called “stairstep effect”. It causes that, the surface should be processed by additional finishing (postprocessing). To minimize the additional machining process, the model should be set...