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Search results for: COMPLEX URBAN STRUCTURES
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On the use of instantaneous complex frequency for analysis and modification of simple sounds
PublicationW pracy przedstawiono możliwości wykorzystania zespolonej pulsacji chwilowej do analizy i modyfikacji prostych dźwięków. Opisywany algorytm składa się z dwóch kroków: bifaktoryzacji sygnału na obwiednię minimalnofazową i fazor dodatnipskrętny, a następnie estymacja i modyfikacja zespolonej pulsacji chwilowej obu czynników faktoryzacji.
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Complex investigations of structural and thermal properties of silica-titania adsorbents
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Obesity and hypertension—the issue is more complex than we thought
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Technological and tribological aspects of milling-burnishing process of complex surfaces
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Molecular modelling of amphotericin B-ergosterol primary complex in water
PublicationBadano właściwości pierwotnego kompleksu amfoterycyny B z ergosterolem przy pomocy symulacji dynamiki molekularnej. Otrzymane w wyniku naszych symulacji rezultaty słabo odpowiadają postulowanym przez innych autorów modelom kompleksu antybiotyk-sterol. Z drugiej strony uzyskane geometrie nie są sprzeczne z wynikami eksperymentów biofizycznych dotyczących powstawania kompleksów w wodzie i w środowisku wodno-alkoholowym.
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Modelling and computer programmes for dynamie analysis of complex mechanical systems
PublicationPraca dokumentuje dokonania samodzielnych pracowników naukowych Wydziału Mechanicznego Politechniki Gdańskiej i ma na celu przedstawienie i rozpowszechnienie wyników badań prowadzonych na Wydziale, szczególnie w ramach grantów KBN, rozpraw doktorskich i habilitacyjnych w ostatnich kilku latach.
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Estimation and tracking of complex-valued quasi-periodically varying systems
PublicationW artykule rozważany jest problem identyfikacji obiektów o parametrach zmieniających się w sposób pseudookresowy. Przedstawiono w nim algorytm oparty o metodę funkcji bazowych umożliwiający śledzenie takich obiektów oraz pokazano atrakcyjne z punktu widzenia złożoności obliczeń jego wersje zdekomponowane. Przydatność rozważanych algorytmów uzasadniono porównując je z rozwiązaniami innych autorów.
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Analysis of graphene multi-strip planar guiding structures with the use of spectral domain approach
PublicationSpectral domain approach is modified and used to analyze some simple structures containing graphene strips. The modification is simple and concerns the Green’s function only. Moreover, the method is combined with the recently published root finding algorithms, which significantly improve the efficiency of the analysis. The results obtained for a simple guiding structure is verified and the field displacement effect is confirmed.
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Reactions of cobalt(ii) chloride and cobalt(ii) acetate with hemisalen-type ligands: ligand transformation, oxidation of cobalt and complex formation. Preliminary study on the cytotoxicity of Co(ii) and Co(iii) hemisalen complexes
PublicationSeveral molecular cobalt(II) complexes, one Co(II) coordination polymer, and one ionic cobalt(III) complex with imine hemisalen ligands were synthesized. The hemisalen ligands were synthesized from o-vanillin (oVP) and diverse aminopyridines (compounds HL1–HL4) or aminophenol (compound HL5). It was observed that cobalt(II) chloride in dry acetonitrile catalyzes a transformation of HL1 and HL3 instead of complex formation. The conversion...
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Examination of advanced isotropic constitutive laws under complex stress states in plain and reinforced concrete specimens
PublicationThe performance of advanced isotropic constitutive laws under complex stress states in plain and reinforced concrete specimens is investigated. Three different formulations are chosen: original Mazars model, Mazars mi model and model proposed by Pereira and coworkers. The degradation of the material in all formulations is described via a single variable, but a strain/stress state is taken into account via quite sophisticated relationships....
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Efficient model order reduction for FEM analysis of waveguide structures and resonators
PublicationAn efficient model order reduction method for three-dimensional Finite Element Method (FEM) analysis of waveguide structures is proposed. The method is based on the Efficient Modal Order Reduction (ENOR) algorithm for creating macro-elements in cascaded subdomains. The resulting macro-elements are represented by very compact submatrices, leading to significant reduction of the overall number of unknowns. The efficiency of the model...
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Lower rim substituted p-tert-butylcalix[4]arene; Part 14. Synthesis, structures and binding studies of calix[4]arene thioamides
PublicationA number of p-tert-butylcalix[4]arene thioamides were synthesized and characterized by 1H-NMR and elemental analysis. Compounds 1-5 are O-substituted derivatives with -CH2-C(=S)-N-X groups, where NX = morpholidyl, NEt2, NHC2H4Ph, NHCH2Ph and NHEt,respectively. The X-ray structures of the ligands 1, 3, 5 and of the complex 3Pb(ClO4)2, (compound 6), are presented and their slightly distorted cone conformation is established. The...
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Modeling of the M X-ray line structures for tungsten and L X-ray line structures for molybdenum
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Slow-wave resonant structures in branch-line coupler miniaturization: a case study
PublicationA case study of novel slow-wave resonant structures dedicated to efficient microstrip branch-line coupler size reduction has been presented. A compact 3-dB branch-line coupler has been designed to mimic the performance of its conventional counterpart, simultaneously demonstrating a substantial 88% surface area reduction. The vital usefulness of the approach in the process of microstrip line abbreviation has been experimentally...
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Computationally Efficient Design Optimization of Compact Microwave and Antenna Structures
PublicationMiniaturization is one of the important concerns of contemporary wireless communication systems, especially regarding their passive microwave components, such as filters, couplers, power dividers, etc., as well as antennas. It is also very challenging, because adequate performance evaluation of such components requires full-wave electromagnetic (EM) simulation, which is computationally expensive. Although high-fidelity EM analysis...
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Crystal and electronic structures of Ni(II) silanethiolates containing flexible diamine ligands
PublicationFive nickel(II) complexes containing aliphatic diamines and tri-tert-butoxysilanethiolate ligand have been synthesized for the purpose of studying their structural, spectral (IR, UV–Vis, HF EPR) and thermal properties. Complexes (1)–(5) have been prepared in high yield by reactions of [Ni{SSi(OtBu)3}2(NH3)(H2O)] with 1.3-propanediamine (L1), 1,6-hexanediamine (L2), or 1,7-heptanediamine (L3). The X-ray structures were determined...
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Kościoły międzywojennej Gdyni - kontekst urbanistyczny i architektoniczny =The churches of the Interwar Gdynia - the urban and architectural context
PublicationArtykuł prezentuje kościoły zbudowane w Gdyni w okresie międzywojennym: dwa w śródmieściu i po jednym w takich dzielnicach jak Witomino, Grabówek, Działki Leśne, Wzgórze Focha, Cisowa i Oksywie. Ukazano dzieje budowy tych obiektów ich architekturę i autorów oraz spoecyficzny kontekst urbanistyczny nowo powstającego miasta.
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DEM investigations of two-dimensional granular vortex- and anti-vortex- structures during plane strain compression.
PublicationDEM investigations of two-dimensional granular vortex- and anti-vortex- structures during plane strain compression.
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Exploring educational traditions and experiences of block residents engaging in urban food self-production: a case study of Urban Living Lab
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Hybrid Finite Element Method Development for Offshore Structures’ Calculation with the Implementation of Industry Standards
PublicationIn the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulationand evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modelingand solution rely on finite element methods and cover the simulation of the structure’s properties along with the influenceof the marine environment – sea currents, wave...
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Detection of the First Component of the Received LTE Signal in the OTDoA Method
PublicationIn a modern world there is a growing demand for localization services of various kinds. Position estimation can be realized via cellular networks, especially in the currently widely deployed LTE (Long Term Evolution) networks. However, it is not an easy task in harsh propagation conditions which often occur in dense urban environments. Recently, time-methods of terminal localization within the network have been the focus of attention,...
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Change in Heavy Metals Concentrations in Sediments Deposited in Retention Tanks in a Stream after a Flood
PublicationOur paper presents the results of heavy metal (HM) (Zn, Cu, Pb, Cd) content in bottom sediments from retention tanks along Oliwa Stream in Gdańsk, Poland, before a flood (BF) and after a flood (AF) 14-15 July 2016. The flood had a huge impact on the quality of bottom sediments and their displacement. The concentrations of HM differed significantly for research series conducted 3 months BF and 8 months AF. The concentration of Cu...
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Adaptive system for recognition of sounds indicating threats to security of people and property employing parallel processing of audio data streams
PublicationA system for recognition of threatening acoustic events employing parallel processing on a supercomputing cluster is featured. The methods for detection, parameterization and classication of acoustic events are introduced. The recognition engine is based onthreshold-based detection with adaptive threshold and Support Vector Machine classifcation. Spectral, temporal and mel-frequency descriptors are used as signal features. The...
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Changes in the structure of Armenia’s labour resources between 1993 and 2020
PublicationThe article characterises the structure of Armenia’s labour resources in the period between1993 and 2020. It aims to assess the changes on the Armenian labour market by means of a deductive analysis of historical data and observation of changes in the structure of resources based on generally available macroeconomic data. The authors evaluate these processes against the background of demographic and economic changes, by presenting...
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Effective density of airborne wear particles from car brake materials
PublicationPeople living in urban environments are subject to high health risks due to various anthropogenic sources of airborne particulate matter, including wear of transport vehicle brakes. Studies of airborne particles often require an estimate of the effective particle density, a property that allows correct matching of mass and size characteristics measured by different aerosol instruments. In this study we investigated the effective...
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Porosity and shape of airborne wear microparticles generated by sliding contact between a low-metallic friction material and a cast iron
PublicationThe wear of brakes in transport vehicles is one of the main anthropogenic sources of airborne particulate matter in urban environments. The present study deals with the characterisation of airborne wear microparticles from a low-metallic friction material / cast iron pair used in car brakes. Particles were generated by a pin-on-disc machine in a sealed chamber at sliding velocity of 1.3 m/s and contact pressure of 1.5 MPa. They...
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Cycling as a Sustainable Transport Alternative in Polish Cittaslow Towns
PublicationIt is well known that growing motor traffic in urban areas causes air pollution and noise which affects the environment and public health. It is hardly surprising then that cycling should be used as an alternative mode of transport, not just in major cities but also in smaller ones including those that are members of the Cittaslow network. Their approach is based on sustainable development, care for the environment and transport...
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Expedited Yield-Driven Design of High-Frequency Structures by Kriging Surrogates in Confined Domains
PublicationUncertainty quantification is an important aspect of engineering design, also pertaining to the development and performance evaluation of high-frequency structures systems. Manufacturing tolerances as well as other types of uncertainties, related to material parameters (e.g., substrate permittivity) or operating conditions (e.g., bending) may affect the characteristics of antennas or microwave devices. For example, in the case...
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An investigation on the chemistry of the R2P=P ligand: reactions of a phosphanylphosphinidene complex of tungsten(VI) with electrophilic reagents
PublicationThe nucleophilic properties of the title compound [(2,6-i-Pr2C6H3N)2(Cl)W(η2-t-Bu2PvP)]Li·3DME (1) were investigated in reactions with selected electrophilic reagents such as MeI, M(CO)5THF (M = Cr, Mo, W), AlCl3, and GaCl3. Methylation of 1 by MeI yields phosphanylphosphido complexes [(2,6-i-Pr2C6H3N)2W(X)(1,2-η-t-Bu2PvP–CH3)] (X = Cl, I) (2-Cl/2-I) with the formation of a new P–C bond. Moreover, 1 reacts with electrophilic compounds...
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Structural Dynamics and Stability of Composite Structures
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Monitoring of metal structures with the dynamic methods
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Geodesic monitoring of tower and mast structures
PublicationW artykule przedstawiono obciążenia jakim są poddawane konstrukcje wieżowe i masztowe. Opisano zakres oraz wymagania dotyczące pomiarów geodezyjnych przeprowadzanych w czasie eksploatacji konstrukcji smukłych. Wskazano metody pomiaru oraz zaprezentowano niektóre sposoby pomiaru w praktyce. Zamieszczono wyniki pomiarów przemieszczeń elektrowni wiatrowej o mocy 2 MW i wysokości elementu wsporczego 80 m oraz zaprezentowano pomiary...
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Unusual structures of Mg2F5- superhalogen anion
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Geosynthetics tests in hydrotechnical structures design
PublicationW celu właściwego stosowania w konstrukcjach budowlanych (w tym również hydrotechnicznych)geosyntetyków - zarówno przepuszczalnych (geotekstylia i wyroby pokrewne) jak i nieprzepuszaczalnych (geomembrany i kompozyty uszczelniające), bardzo ważne jest wcześniejsze poddawanie go odpowiednim badaniom, których procedura musi być ściśle powiązana z późniejszym przeznaczeniem geomateriału i uwzględniać warunki, w jakich materiał będzie...
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Modal diagnostics of civil engineering structures.
PublicationKsiążka dotyczy zastosowania analizy modalnej do diagnostyki konstrukcji budowlanych.
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Selected problems of stability of steel structures.
PublicationW pracy przedstawiono wyniki badań dotyczących stateczności wybranych konstrukcji stalowych. Prezentowane rozważania są oparte na klasycznych założeniach teorii prętów cienkościennych o nieodkształcalnym przekroju poprzecznym. Wyznaczono pierwszą wariację sił krytycznych pręta cienkościennego o bisymetrycznym otwartym przekroju poprzecznym uwzględniając następujące zmienne projektowe: ⎯wymiary przekroju poprzecznego, ⎯ charakterystyki...
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Development of quay structures for container harbour .
PublicationPrace poświęcono nowym rozwiązaniom konstrukcyjnym nabrzeży przeznaczonym do przeładunku kontenerów. Zwrócono przy tym głównie uwagę na spełnienie warunków stateczności w przypadku występowania dużych prędkości strumieni zaśrubowych wywołanych napędami statków podczas ich manewrowania.
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Strengthening of structures by shock transmission units.
PublicationCelem niniejszego artykułu jest analiza możliwości zastosowania tzw. przenośników drgań do wzmacniania konstrukcji budowlanych (w tym mostowych) narażonych na oddziaływania dynamiczne takie jak: wiatr, siły hamowania pojazdów czy trzęsienia ziemi.
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Simulation and identification of damage in bar structures.
PublicationPraca zawiera opis i testy 3 procedur badawczych dotyczących lokalizacjizniszczeń w konstrukcjach. Procedury bazują na danych modalnych jakie obiektgeneruje podczas swoich drgań tzn. częstościach własnych i postaciach drgań Badane są zmiany podatności układu, zmiany krzywizn postaci drgań i wrażli-wość częstości na założone zniszczenia. Odpowiednie procedury wiążące się ztymi trzema metodami są przestestowane na przykładzie wspornika...
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On Reduced-Cost Design-Oriented Constrained Surrogate Modeling of Antenna Structures
PublicationDesign of contemporary antenna structures heavily relies on full-wave electromagnetic (EM) simulation models. Such models are essential to ensure reliability of evaluating antenna characteristics, yet, they are computationally expensive and therefore unsuitable for handling tasks that require multiple analyses, e.g., parametric optimization. The cost issue can be alleviated by using fast surrogate models. Conventional data-driven...
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Advanced Control Structures of Turbo Generator System of Nuclear Power Plant
PublicationIn the paper a synthesis of advanced control structures of turbine and synchronous generator for nuclear power plant working under changing operating conditions (supplied power level) is presented. It is based on the nonlinear models of the steam turbine and synchronous generator cooperating with the power system. Considered control structure consists of multi-regional fuzzy control systems with local linear controllers, including...
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Advanced Control Structures of Turbo Generator System of Nuclear Power Plant
PublicationIn the paper a synthesis of advanced control structures of turbine and synchronous generator for nuclear power plant working under changing operating conditions (supplied power level) is presented. It is based on the nonlinear models of the steam turbine and synchronous generator cooperating with the power system. Considered control structure consists of multi-regional fuzzy control systems with local linear controllers, including...
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Multidisciplinary approach to the assessment of historic structures based on the case of a masonry bridge in Galicia (Spain)
PublicationThe paper presents a general method to evaluate a masonry structure with a complex geometry and unknown material properties. This multidisciplinary approach integrates close range digital photogrammetry,ground probing radar (GPR) and finite elements analysis (FEM) to analyse a masonry bridge. The resulting information from photogrammetry and radar is applied to define a 3D model, which is then used to simulate the behaviour of...
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Reactions of (Ph)tBuP-P(SiMe3)Li·3THF with [(PNP)TiCl2] and [MeNacNacTiCl2·THF]. Synthesis of first PNP titanium(IV) complex with phosphanylphosphinidene ligand [(PNP)Ti(Cl){η2-P-P(Ph)tBu}]
PublicationLithium derivative of diphosphane (Ph)tBuP-P(SiMe3)Li (1) was isolated for the first time and investigated in reactions with β-diketiminate (MeNacnac− = [Ar]NC(Me)CHC(Me)N[Ar]; Ar = 2,6-iPr2C6H3) and PNP-pincer (PNP = N[2-PiPr2-4-methylphenyl]2) Ti(III) complexes. The β-diketiminate titanium(III) complex containing phosphanylphosphido ligand [MeNacNacTi(Cl){η2-P(SiMe3)-P(Ph)tBu}] (2) was prepared in reaction of [MeNacNacTiCl2·THF]...
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Accelerated Re-Design of Antenna Structures Using Sensitivity-Based Inverse Surrogates
PublicationThe paper proposes a novel framework for accelerated re-design (dimension scaling) of antenna structures using inverse surrogates. The major contribution of the work is a sensitivity-based model identification procedure, which permits a significant reduction of the number of reference designs required to render the surrogate. Rigorous formulation of the approach is supplemented by its comprehensive numerical validation using a...
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Pareto Ranking Bisection Algorithm for Expedited Multi-Objective Optimization of Antenna Structures
PublicationThe purpose of this letter is introduction of a novel methodology for expedited multi-objective design of antenna structures. The key component of the presented approach is fast identification of the initial representation of the Pareto front (i.e., a set of design representing the best possible trade-offs between conflicting objectives) using a Pareto-ranking bisection algorithm. The algorithm finds a discrete set of Pareto-optimal...
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Particle Shape Effect on Macroscopic Behaviour of Underground Structures: Numerical and Experimental Study
PublicationThe mechanical performance of underground flexible structures such as buried pipes or culverts made of plastics depend not only on the properties of the structure, but also the material surrounding it. Flexible drains can deflect by 30% with the joints staying tight, or even invert. Large deformations of the structure are difficult to model in the framework of Finite Element Method, but straightforward in Discrete Element Methods....
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Particle Shape Effect on Macroscopic Behaviour of Underground Structures: Numerical and Experimental Study
PublicationAbstract: The mechanical performance of underground flexible structures such as buried pipes or culverts made of plastics depend not only on the properties of the structure, but also on the material surrounding it. Flexible drains can deflect by 30% with the joints staying tight, or even invert. Large deformations of the structure are difficult to model in the framework of Finite Element Method, but straightforward in Discrete...
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Chitin and derivative chitosan-based structures — Preparation strategies aided by deep eutectic solvents: A review
PublicationThe high molecular weight of chitin, as a biopolymer, challenges its extraction due to its insolubility in the solvents. Also, chitosan, as the N-deacetylated form of chitin, can be employed as a primary material for different industries. The low mechanical stability and poor plasticity of chitosan films, as a result of incompatible interaction between chitosan and the used solvent, have limited its industrialization. Deep eutectic...
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Recent Advances in Performance-Driven Surrogate Modeling of High-Frequency Structures
PublicationDesign of high‐frequency structures, including microwave and antenna components, heavily relies on full‐wave electromagnetic (EM) simulation models. Their reliability comes at a price of a considerable computational cost. This may lead to practical issues whenever numerous EM analyses are to be executed, e.g., in the case of parametric optimization. The difficulties entailed by massive simulations may be mitigated by the use of...