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Search results for: SEMI-ANALYTICAL MODELLING
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Road safety analysis in Poland using time-series modelling techniques
PublicationA number of international studies argue that there is a correlation between the number of traffic fatalities and the degree of public activity. The studies use the unemployment rate to support that argument. As unemployment grows miles travelled fall, a factor known to affect road safety. This relationship seems to be true for Poland, as well. The model presented in the paper is intended to prove it. It is a structural time-series local...
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Urban Freight Transport Demand Modelling and Data Availability Constraints
PublicationThe paper provides a review of urban freight transport demand modelling approaches confronted with constrains regarding adequate data provision from a perspective of the local authorities. Demand estimation models has been selected as a reference because they are the most representative in terms of inclusion of urban freight indicators which can be transformed into a decision-support tool for evaluation of freight measures. The...
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Research on flue gas flow measurement and modelling in the moving grate biomass boiler
PublicationThe aim of this research was to determine the nature of gas flow in a grate boiler model by the method of Particle Image Velocimetry (PIV) and CFD. The paper presents the comparison of the PIV results with numerical simulations made in the environment of ANSYS Fluent. The main goal of the experiment was to describe the phenomena occurring on the grate. Methodology of modelling solid fuel combustion on the moving grate was proposed...
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New Technique of preparation of standard gas mixtures needed for validation of analytical procedures used in environmental studies
PublicationStandard gas mixtures are indispensable reference materials for ensuring the reliability of analytical work. Paper presents one novel approach in the field of production of gaseous reference materials based on the application of thermal decomposition process of proper surface compound for obtaining the desired gaseous analyte. The main fields of application of reference materials are presented. The field of application of thermal...
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Web-based GIS technologies dedicated for presenting semi-dynamic geospatial data
PublicationSieciowe technologie prezentacji danych przestrzennych przeżywają aktualnie rozkwit spowodowany między innymi spadającymi cenami sprzętu komputerowego. Wynikający z tego wzrost wydajności domowych i biurowych stacji roboczych pozwala na praktyczne zastosowanie czasochłonnych algorytmów wizualizacji i przetwarzania skomplikowanych danych rastrowych i wektorowych. Niniejszy artykuł omawia wybrane technologie sieciowej prezentacji...
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Equitable and semi-equitable coloring of cubic graphs and its application in batch scheduling
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Semi- incremental construction of minimal cyclic finite state automata usingcontinuation classes.
PublicationMinimalne automaty skończone są często wybierane do przedstawiania słowników morfologicznych języka naturalnego. Wśród ich zalet znajdują się duża szybkość rozpoznawania i małe wymagania pamięciowe. Tłumaczenie opisów morfologicznych opartych o klasy kontynuacji na minimalne, cykliczne automaty skończone jest tradycyjnie dokonywane w kilku fazach, zawierających tworzenie automatu niedeterministycznego z przejściami etykietowanymi...
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Magnetotransport Properties of Semi-Metallic Bismuth Thin Films for Flexible Sensor Applications
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Parametric versus nonparametric modelling of dynamic susceptibility contrast enhanced MRI based data
PublicationDynamic tracking of a bolus of a paramagnetic agent (dynamic susceptibility contract - DSC) in MRI (magnetic resonance imaging) measurements is successfully used for assessment of the tissue perfusion and the other features and functions of the brain (i.e. cerebral blood flow - CBF, cerebral blood volume - CBV, mean transit time - MTT). The parametric and nonparametric approaches to the identification of MRI models are presented...
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Analytical method for calculation of heat source temperature drop for the Organic Rankine Cycle application
PublicationIn the paper presented are considerations on the cooperation of the limited capacity heat source with the Organic Rankine Cycle unit. Usually the heat source providing thermal energy to the Organic Rankine Cycle (ORC) may have twofold characteristics. It can be in the form of a single phase fluid, i.e. as hot exhaust gas or hot liquid, or in some cases it may be available as a phase changing fluid, as for example, technological...
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A multi-analytical approach to the characterization of natural organic dyestuffs and inorganic substrates present in the 19th-century artistic oil paints manufactured by a French art materials supplier Richard Aines
PublicationThis paper presents a comprehensive analysis of artistic paints produced in the 19th century by a French art materials supplier Richard Ain`es. Improved mild extraction with hydrofluoric acid enabled the observation of intact organic dyes. Reversed-phase liquid chromatography with diode-array and mass spectrometry detection was utilised for the identification of 35 dyes present in yellow and red paint samples, and in selected plant...
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Analytical procedures for quality control of pharmaceuticals in terms of residual solvents content: Challenges and recent developments
PublicationResidual solvents play an important role in the synthesis of drugs and in product formulations. In addition, they pose a serious problem, that is toxicity, as many of them exhibit toxic or environmentally hazardous properties. Therefore, constant monitoring of quality control is needed. In this study, we present an overview of regulatory and general methods described by various pharmacopoeias. Then, the most commonly used methodologies...
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Book review: Simulation-Driven Design Optimisation and Modelling for Microwave Engineering
PublicationCelem książki jest przedstawienie aktualnego stanu badań dotyczących projektowania układów mikrofalowych poprzez modelowanie i optymalizacje wspomagane symulacjami elektromagnetycznymi. Grupa międzynarodowych ekspertów zajmujących się rożnymi aspektami komputerowo wspomaganego projektowania układów mikrofalowych, podsumowuje i dokonuje przeglądu ostatnich osiągnięć w tej dziedzinie oraz przedstawia szereg praktycznych zastosowań....
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Modelling of elastic wave propagation in a bolted joint using a thin layer of shell elements
PublicationThere are many mathematical models describing the propagation of elastic waves through the imperfect boundary of two media. They were successfully applied to modelling of high frequency bulk waves and their interaction with local defects. On the other hand, the existing literature models of bolted connections ignore the aspect of imperfect connection between elements. Therefore, this paper presents the concept of application of...
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Modelling of Longitudinal Elastic Wave Propagation in a Steel Rod Using the Discrete Element Method
PublicationThe paper deals with the issue of modelling elastic wave propagation using the discrete element method (DEM). The case of a longitudinal wave in a rod with a circular cross-section was considered. A novel, complex algorithm consisting of the preparation of models and simulation of elastic waves was developed. A series of DEM models were prepared for simulations, differing in discretisation and material parameters. Additional calculations...
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The Dynamics of Trade Relations between Ukraine and Romania: Modelling and Forecasting
PublicationThe article examines the monthly dynamics of exports, imports and balance of trade between Ukraine and Romania in the period from 2005 to 2021. Time series from 2015 to 2021 were used for modelling and forecasting (since the date the European Union–Ukraine Association Agreement took effect). Adequate models of the dynamics series of the Box-Jenkins methodology were built: additive models with seasonal component ARIMA (Autoregressive...
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House dust as a source of analytical information on concentration of polybrominated diphenyl ethers (PBDEs) - first approach
PublicationPolybrominated diphenyl ethers (PBDEs), which are best recognized as flame retardants, were in 2001, by virtue of Stockholm Convention, listed in a group of Persistent Organic Compounds (POPs). Increasing concentration levels of PBDEs, reported in human tissues (e.g., blood, serum, breast milk, etc.) haverecently caught worldwide concern due to their potential tendency to disrupt thyroid hormones, neurobehavioral deficits and endocrine...
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The optimisation of analytical parameters for routine profiling of antioxidants in complex mixture by HPLC coupled post-column derivatisation
PublicationIntroduction: The wide application of natural and artificial antioxidants in food, cosmetic and pharmaceutical industry as well as the recognition of the importance of food antioxidants for supporting human health created demand for reliable and industrially applicable methods of determining antioxidative activity. This requirement can be fullfilled with the recently proposed HPLC-post-column derivatisation approach enabling the...
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Surf Zone Currents in the Coastal Zone of the Southern Baltic Sea – a Modelling Approach
PublicationNearshore currents in a multi-bar non-tidal coastal zone environment located in the Southern Baltic Sea are studied. Spatiotemporal seaward-directed jets – so-called rip currents – are an important part of the nearshore current system. In previous research, Dudkowska et al. (2020) performed an extended modelling experiment to determine the wave conditions that are conducive to the emergence of rip currents. In this paper, the...
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Numerical Modelling of Connections Between Stones in Foundations of Historical Buildings
PublicationThe aim of this paper is to analyse the behaviour of old building foundations composed of stones (the main load-bearing elements) and mortar, based on numerical analysis. Some basic aspects of historical foundations are briefly discussed, with an emphasis on their development, techniques, and material. The behaviour of a foundation subjected to the loads transmitted from the upper parts of the structure is described...
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Adaptive estimation of the transformer stray capacitances for DC–DC converter modelling
PublicationNew low cost and accurate estimation method of transformer stray capacitances for wide band DC–DC converter modelling and design is proposed. The Wiener filter (WF) method is applied to estimate the transformer impedance – referred to the selected transformer winding configurations. Laboratory tests are used to adapt the filter, that is to find optimal impedance which minimises mean square error between measured, noise perturbed...
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The Matter of Decision-Making Control Over Operation Processes of Marine Power Plant Systems with the Use of their Models in the form of Semi-Markov Decision-Making Processes
PublicationThe article presents the possibility to control the real operation process of an arbitrary device installed in the marine power plant based on the four-state semi-Markov process, being the model of the process, which describes the transition process of operational states of the device and the transition process of its technical states. All these states are precisely defined for the ship main engine (SG). A hypothesis is proposed...
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Problems with modelling the strength properties of sailing vessels rigging ropes
PublicationThis article presents the basic parameters of soft ropes: natural fibre ropes, soft wire ropes and synthetic fibre ropes used for running rigging. There are only several materials still used for the production of natural fibre ropes, including cotton, jute, hemp, sisal and manila hemp. The most commonly used soft wire ropes are twisted pair ropes; for smaller diameters there is a 6x19M - FC rope and for larger diameters – 6x37M...
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MODELLING OF THE VISCOSITY EFFECT OF HEAVE PLATES FOR FLOATING WIND TURBINES BY HYDRODYNAMIC COEFFICIENTS
PublicationOne of the methods of modelling the movement of floating wind turbines is the use of the diffraction method. However, this method does not take into account the influence of viscosity; therefore, in many cases, it needs to be extended with a matrix of appropriate coefficients. The effect of viscosity causes both the added mass coefficient and the damping coefficient to increase. The determined coefficients were entered into the...
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Identification and non-integer order modelling of synchronous machines operating as generator
PublicationThis paper presents an original mathematical model of a synchronous generator using derivatives of fractional order. In contrast to classical models composed of a large number of R-L ladders, it comprises half-order impedances, which enable the accurate description of the electromagnetic induction phenomena in a wide frequency range, while minimizing the order and number of model parameters. The proposed model takes into account...
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The Algorithm of Modelling and Analysis of Latent Semantic Relations: Linear Algebra vs. Probabilistic Topic Models
PublicationThis paper presents the algorithm of modelling and analysis of Latent Semantic Relations inside the argumentative type of documents collection. The novelty of the algorithm consists in using a systematic approach: in the combination of the probabilistic Latent Dirichlet Allocation (LDA) and Linear Algebra based Latent Semantic Analysis (LSA) methods; in considering each document as a complex of topics, defined on the basis of separate...
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Multivariate statistical comparison of analytical procedures for benzene and phenol determination with respect to their environmental impact
PublicationThe studydescribesthepossibilityofapplicationofself-organizingmapstechniquetoassessthe greenness ofanalyticalmethodologies.Themetrologicaland “environmentalimpact” parametersof proceduresforbenzeneandphenoldeterminationinwatersamplesweresetsofinputdatafor chemometric analysis.Totally47objectsand8variablesformedthedatausedforanalysis.Themajor factors responsiblefornon-greencharacterofthemethodologyaretheamountoforganicsolventand amount...
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Novel analytical method for detection of orange juice adulteration based on ultra-fast gas chromatography
PublicationThe food authenticity assessment is an increasingly important issue in food quality and safety. The application of an electronic nose based on ultra-fast gas chromatography technique enables rapid analysis of the volatile compounds from food samples. Due to the fact that this technique provides chemical profiling of natural products, it can be a powerful tool for authentication in combination with chemometrics. In this article,...
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Pathways and analytical tools in degradation studies of organic pollutants
PublicationWszystkie substancje chemiczne podlegają różnym procesom w wyniku wielu reakcji chemicznych, biochemicznych czy też fotochemicznych. W zależności od elementu środowiska w jakim znajduje się analit (np.: gleba, sedymenty, wody powierzchniowe i podziemne), może on ulegać powolnym przemianom w wyniku różnych procesów. W pracy przedstawiono niektóre drogi degradacji wybranych substancji w różnych warunkach. Omówiono problem identyfikacji...
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Analytical techniques used in monitoring of atmospheric air pollutants
PublicationW artykule opisano najczęściej spotykane zanieczyszczenia powietrza atmosferycznego, ich interakcje i wpływ na środowisko. Przedstawiono klasyfikację technik i metodyk stosowanych w badaniach zanieczyszczeń powietrza. Przeprowadzono przegląd technik pobierania i dozowania próbek gazowych. Zaprezentowano także przykłady typowych systemów służących do analizy zanieczyszczeń powietrza.
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Analytical procedures used in examining human urine samples.
PublicationŹródłem informacji o stanie środowiska mogą być zarówno wyniki badań próbek części nieożywionej (woda, gleba, powietrze) jak i części biotycznej, w tym także tkanek i płynów ustrojowych człowieka, który jest nieustannie narażony na działanie szerokiego spektrum ksenobiotyków. Badanie płynów ustrojowych człowieka (głównie krwi i moczu) może być bardzo użyteczną i interesującą drogą do uzyskania informacji o stanie środowiska....
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Consolidation analysis of clayey soils using analytical tools
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Analytical and numerical solution of a coupled KdV - MKdV system.
PublicationTransformację Darboux zastosowano do całkowania układów równań KdV - MKdV.Reprezentacja Laxa używa 2x2 macierzowe zagadnienie spektralne drugiego rzędu. Numeryczną metodę wprowadzono razem z dowodem zbieżności.
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Analytical and numerical solution of a coupled KdV-MKdV system.
PublicationTransformacje Darboux zostały użyte do rozwiązania układu równań KdV-MKdV.
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Estimating uncertainty in analytical procedures based on chromatographic techniques
PublicationTechniki chromatograficzne są bardzo często wykorzystywane w procedurach analitycznych na etapie rozdzielania i oznaczania oraz identyfikacji szerokiego spektrum analitów występujących w próbkach charakteryzujących się złożonym a niekiedy także zmiennym matryce. Bardzo często są jednak sytuacje, że przy oszacowywaniu niepewności wyników oznaczeń końcowych pomija się niepewności związane z procesem chromatograficznym. W efekcie...
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Some analytical assays for the determination of bioactivity of exotic fruits
PublicationPrzedmiotem badań były próbki owoców egzotycznych (mango, durian, gruszka adwokacka) zebrane w 2008 roku w Tajlandii i w Izraelu (po etapie liofilizacji). W próbkach oznaczano zawartość:- białek, - tłuszczów,- węglowodanów,- flawonoidów,- tanin- polifenoli stosując zarówno zaawansowane techniki instrumentalne jak i proste testy spektrofotometryczne (FRAP, ABTS, DPPH, CUPRAC). Uzyskana wieloparametrowa baza danych pomiarowych została...
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Analytical characteristics of a new amperometric sulfur dioxide sensor
PublicationZaprojektowano i skonstruowano wyposażony w układ trójelektrodowy amperometryczny czujnik ditlenku siarki. Elektroda pracująca czujnika była napylona bezpośrednio na powierzchnię membrany. Zbadano charakterystyki czujnika z membranami z mikroporowatego Teflonu oraz Nafionu. Porównano parametry statyczne i dynamiczne tych czujników wypełnionych roztworami elektrolitów wewnętrznych, zawierających dodatek dimetylosulfotlenku.
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Analytical Steady-State Model of the Pipeline Flow Process
PublicationThe paper addresses the issue of modeling the flow process in transmission pipelines. A base model used for numerical simulation is introduced. Under certain assumptions concerning steady state analysis, the differential equations describing the process are solved analytically for two cases: zero and nonzero inclination angle α. These equations describe a constant flow rate and a corresponding distribution of the pressure along...
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Analytical fluctuation enhanced sensing by resistive gas sensors
PublicationResistance fluctuations across polarised resistive gas sensors were studied in detail to evaluate sensor working conditions for detecting methane and ammonia at various concentrations. The 1/f noise component typically dominates other noise sources up to a few kHz and can be utilised to improve gas selectivity when compared with measurements of the sensor DC resistance. The Arrhenius plot was created and the activation energy for...
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Photogrammetry image-based approach for imperfect structure modelling and FE analysis
PublicationThis study aims to model and analyse imperfect tructures using real measurements, employing photogrammetry technique commonly used in the geodesy. The study highlights the capability of the photogrammetry in aiding the structural analysis of imperfect engineering objects. Firstly, the photogrammetry measurements of a stiffened plate are carried out using a specially designed for the purpose experimental stand. Then, the plate surface...
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Chemical-vapor generation of transition metals through the reaction with tetrahydroborate in recent achievements in analytical atomic spectrometry
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An analytical performance of atmospheric pressure glow discharge generated in contact with flowing small size liquid cathode
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Analytical studies on ascosin, candicidin and levorin multicomponent antifungal antibiotic complexes. The stereostructure of ascosin A2
PublicationIn the class of polyene macrolides, there is a subgroup of aromatic heptaenes, which exhibit the highest antifungal activity within this type of antibiotics. Yet, due to their complex nature, aromatic heptaenes were not extensively studied and their potential as drugs is currently underexploited. Moreover, there are many inconsistencies in the literature regarding the composition and the structures of the individual components...
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Spectral Methods for Modelling of Wave Propagation in Structures in Terms of Damage Detection—A Review
PublicationModern methods of detection and identification of structural damage direct the activities of scientific groups towards the improvement of diagnostic methods using for example the phenomenon of mechanical wave propagation. Damage detection methods that use mechanical wave propagation in structural components are extremely effective. Many different numerical approaches are used to model this phenomenon, but, due to their universal...
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An assessment of wastewater pollution, treatment efficiency and management in a semi-arid urban area of Pakistan
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Semi-Markow Processes as Models of Devices´ Operating Process of Ship Pro-pulsion System
PublicationReferat zawiera formalny opis procesu eksploatacji urządzeń.
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An attempt to identify volatile and semi-volatile organic compounds present in the Odra river waters.
PublicationCelem pracy była identyfikacja związków z grup lotnych i średniolotnych związkó organicznych. W badaniach wykorzystano technikę Pt-TD-GC-MS. Komputerowa analiza widm masowych wykazała obecność wielu związków organicznych pochodxenia naturalnego i antropogenicznego. W powłokach wód pobranych w okolicy Brzegu Dolnego oznaczono stężenia związków chloroorganicznych na poziomie pojedynczych prób. Nieco wyższe spektrum związków chloroorganicznych,...
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Intensification of thermal convection near electric devices using flat screens – computer modelling
PublicationIntensification of natural thermal convection near electric devices is possible by application of additional elements as screens creating convection canals close to the device. In the earlier authors paper the results of the analysis of thermal convection with the use of only one additional screen close to the electric device were presented. This paper presents computer modelling of thermal convection when two screens near the...
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Modelling of two-component turbulent mass and heat transfer in air-fed pressurised suits
PublicationIn this paper the modelling of an important industrial problem is addressed, which involves the two-component turbulent flow with heat transfer that takes place inside protective clothing. The geometry of the flow boundaries is reconstructed in a CAD system from photogrammetry scan data. The overall model is sufficiently realistic to allow, after validation, design improvements to be tested. Those presented here allow the reduction...
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Numerical Modelling of Shear Localization in Granular Bodies using MPM and Non-local Hypoplasticity
PublicationThe paper deals with modelling of shear localization in granular bodies by means of an enhanced hypoplastic constitutive model and material point method (MPM). The calculations were carried out for plane strain compression of non-cohesive sand. In order to properly capture the width and inclination of shear zones, the constitutive model was enriched by a characteristic length of micro-structure by means of a non-local theory....