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Search results for: SEMI-ANALYTICAL MODELLING
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Modelling of heat and mass transfer through wooden buildings
PublicationThe aim of this review paper is to examine the most recent available studies dealing with theoretical, numerical and experimental aspects related to modelling of heat and mass transfer through wooden buildings. The main thermophysical, mechanical and hygrometric properties of wood are firstly discussed. Then, the basic governing equations of heat and mass transfer phenomena are presented. A detailed description of the physical...
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Importance of sign conventions on analytical solutions to the wave-induced cyclic response of a poro-elastic seabed
PublicationThis paper discusses the influence of different sign conventions for strains and stresses, i.e. the solid mechanics sign convention and the soil mechanics sign convention, on the form of governing partial differential equations (the static equilibrium equations and the continuity equation) used to describe the wave-induced cyclic response of a poro-elastic seabed due to propagation of a sinusoidal surface water-wave. Some selected...
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Hydrological predictors used for vegetation modelling in the lower Biebrza valley 1900-2099
Open Research DataThis data set contains hydrological predictors used for vegetation modelling in the lower Biebrza valley, NE Poland.The predictors were obtained from simulations using integrated hydrological model - HydroGeoSphere, with the Hydraulic Mixing-Cell method.Forcing data for the model were Twentieth Century Reanalysis (20CR) data for the period 1900-2015...
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Life Cycle Assessment of Analytical Protocols
PublicationLife cycle assessment is a relatively new tool for environmental management, which is becoming more and more important owing to the globalization of the world economy, where there is a need to develop standards in protecting the environment
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Mineral components in food - analytical implications
PublicationRozdział w całości poświęcony jest analizie próbek żywności pod kątem oznaczania w nich mikro i makroelementów. Przedstawione zostały metody przygotowania próbek oraz techniki wykorzystywane na etapie oznaczeń końcowych.
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Analytical procedure for the determination of chlorobenzenes in sediments
PublicationW pracy przedstawiono badania nad opracowaniem procedury oznaczania chlorobenzenów w próbkach osadów dennych. Składa się ona z następujących etapów: ekstrakcji za pomocą rozpuszczalnika (wytrząsanie); oczyszczanie ekstraktu; odparowanie rozpuszczalnika (redukcja objętości ekstraktu); analiza z wykorzystaniem techniki GC-MS. Przeprowadzono badania stopnia odzysku z wykorzystaniem wzorca wewnętrznego (deuterowany 1,2-dibromobenzen).
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Analytical design method of reverse curves
PublicationThe paper deals with a new approach relating to the design of the region of railway track direction alteration adapted to Mobile Satellite Measurements technique. The method may be particularly useful in situations when both the straights of the route directions cannot be connected in an elementary way using a circular arc with transition curves; this also refers to the application of a compound curve. Thus the only solution becomes...
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Perspectives on the replacement of harmful organic solvents in analytical methodologies: a framework toward the implementation of a generation of eco-friendly alternatives
PublicationVolatile organic solvents derived from non-renewable fossil feedstocks are commonplace in analytical laboratories. In spite of their convenient performance in countless unit operations, their environmental, health and safety issues represent a major area of concern. The progressive replacement of organic solvents obtained from fossil resources by eco-friendly alternatives would involve remarkable advances within the framework of...
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GENERALISED HERSCHEL MODEL APPLIED TO BLOOD FLOW MODELLING
PublicationThis paper introduces a new rheological model of blood as a certain generalisation of the standard Herschel-Bulkley model. This model is a rheological constitutive equation and belongs to the group of the so-called generalised Newtonian fluids. Experimental data is compared with results, obtained from the new model, to demonstrate that it allows for the best agreement together with Luo-Kuang model. The new model may be easily implemented...
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A two dimensional approach for modelling of pennate muscle behaviour
PublicationThe purpose of this study was to elaborate a two-dimensional approach for unipennate and bipennate striated skeletal muscle modelling. Behavior of chosen flat pennate muscle is modelled as a rheological system composed of serially linked passive and active fragments having different mechanical properties. Each fragment is composed of three elements: mass element, elastic element and viscous element. Each active fragment furthermore...
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Amygdalin: Toxicity, Anticancer Activity and Analytical Procedures for Its Determination in Plant Seeds
PublicationAmygdalin (D-Mandelonitrile 6-O--D-glucosido--D-glucoside) is a natural cyanogenic glycoside occurring in the seeds of some edible plants, such as bitter almonds and peaches. It is a medically interesting but controversial compound as it has anticancer activity on one hand and can be toxic via enzymatic degradation and production of hydrogen cyanide on the other hand. Despite numerous contributions on cancer cell lines, the clinical...
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APPLICATION OF THE THEORY OF SEMI-MARKOV PROCESSES TO DETERMINE A LIMITING DISTRIBUTION OF THE PROCESS OF CHANGES OF ABILITY AND INABILITY STATES OF FUEL SUPPLY SYSTEMS IN HEAVY FUEL DIESEL ENGINES
PublicationThe paper presents applicability of the theory of semi-Markov processes to determine a limiting distribution of the process of changes of technical states of fuel systems for marine engines running on heavy fuel oils. The proposed study of this process includes the components of such fuel systems like: 1 - injectors, 2 - high pressure hoses, 3 - injection pumps, 4 - low pressure hoses, 5 – fine filters, 6 - coarse filters, 7 – fuel-feed...
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On various modelling approaches to real-time visualisation of blood flow
PublicationThis paper reviews various modelling approaches to real-time visualisation of blood flow. These include classic, macroscale approach based on the momentum conservation equation together with a proper constitutive equation. Moreover, modern micro- and mesoscale approaches, such as molecular dynamics and dissipative particle dynamics, are discussed. Advantages and disadvantages of the discussed methods are highlighted with particular...
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Cost‐efficient performance‐driven modelling of multi‐band antennas by variable‐fidelity electromagnetic simulations and customized space mapping
PublicationElectromagnetic (EM) simulations have become an indispensable tool in the design of contemporary antennas. EM‐driven tasks, for example, parametric optimization, entail considerable computational efforts, which may be reduced by employing surrogate models. Yet, data‐driven modelling of antenna characteristics is largely hindered by the curse of dimensionality. This may be addressed using the recently reported domain‐confinement...
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A novel heterogeneous model of concrete for numerical modelling of ground penetrating radar
PublicationThe ground penetrating radar (GPR) method has increasingly been applied in the non-destructive testing of reinforced concrete structures. The most common approach to the modelling of radar waves is to consider concrete as a homogeneous material. This paper proposes a novel, heterogeneous, numerical model of concrete for exhaustive interpretation of GPR data. An algorithm for determining the substitute values of the material constants...
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Application of deep eutectic solvents in analytical sample pretreatment (update 2017–2022). Part A: Liquid phase microextraction
PublicationSustainable development in all branches of human activity has become an unequivocal necessity in the last two decades, and green chemistry goes hand in hand with it. Various ways have been proposed in analytical chemistry to meet the current requirements of green chemistry. One such approach is the research of new reagents and solvents for analytical purposes. Deep eutectic solvents (DESs) began being investigated and used in analytical...
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An analytical approach to determine the health benefits and health risks of consuming berry juices
PublicationFood products composition analysis is a prerequisite for verification of product quality, fulfillment of regulatory enforcements, checking compliance with national and international food standards, contracting specifications, and nutrient labeling requirements and providing quality assurance for use of the product for the supplemen- tation of other foods. These aspects also apply to the berry fruit and berry juice. It also must...
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Simplified saturation modelling in three-leg power transformer for the system stability analisys
PublicationThe paper presents a simplified method for modelling non-linearity of the magnetic circuit of the power transformer. The saturation effect is implemented by describing the self and mutual inductances as a function of the magnetic flux. The most important element of this function is the saturation coefficient which is calculated based on transient state during the unloaded transformer switch on. The transformer model is described...
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Relevance of Urban Freight Transport Modelling Towards the Challenges of Urban Freight Policy
PublicationThe main objective of this paper is to investigate how recent trends in urban freight transport analysis and modelling are related to urban freight measures set out in Gdynia’s 2016 Sustainable Urban Mobility Plan. Building on the literature a review framework was defined including 1) stakeholders, 2) descriptors, 3) objectives and 4) solution approach applied in freight modelling efforts. It was clear that the implementation...
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Analytical Techniques for Determining Pharmaceutical Residues in Drinking Water – State of Art and Future Prospects
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Geometric methods in dynamical systems modelling: electrical, mechanical and control systems
PublicationRozważono zagadnienia modelowania systemów dynamicznych z zastosowaniem metod geometrii różniczkowej. Równania dynamiczne otrzymano w postaci inkluzji różniczkowych. Przestrzenie konstytucyjne przyjęto w postaci subwiązek włóknistych. Rozważono przestrzenie konstytucyjne układów elektrycznych, układów mechanicznych i układów sterowania. Podstawowe wyniki pracy dotyczą struktury przestrzeni rozwiązań rozważanych systemów.
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Journal of Analytical Methods in Chemistry
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Analytical calculations of scattering lengths for a class of long-range potentials of interest for atomic physics
PublicationWe derive two equivalent analytical expressions for an $l$th partial-wave scattering length $a_{l}$ for central potentials with long-range tails of the form % \begin{math} \displaystyle V(r)=-\frac{\hbar^{2}}{2m}\frac{Br^{n-4}}{(r^{n-2}+R^{n-2})^{2}} -\frac{\hbar^{2}}{2m}\frac{C}{r^{2}(r^{n-2}+R^{n-2})}, \end{math} % ($r\geqslant r_{s}$, $R>0$). % For $C=0$, this family of potentials reduces to the Lenz potentials discussed in...
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Low cost real time UAV stereo photogrammetry modelling technique – accuracy considerations
PublicationThe paper presents accuracy considerations regarding three 3D modelling techniques. The tested new consumer type stereo camera (ZED 3D Stereolabs) has been implemented info an aerial mapping system, on board micro air vehicle MAV) and tested object has been mapped using a real-time photogrammetry with original real-time software application. The evaluated results has been compared with model gained with a state of art unmanned...
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Numerical Modelling of Forced Convection of Nanofluids in Smooth, Round Tubes: A Review
PublicationA comprehensive review of published works dealing with numerical modelling of forced convection heat transfer and hydrodynamics of nanofluids is presented. Due to the extensive literature, the review is limited to straight, smooth, circular tubes, as this is the basic geometry in shell-and-tube exchangers. Works on numerical modelling of forced convection in tubes are presented chronologically in the first part of the article....
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Improved Uniform Sampling in Constrained Domains for Data-Driven Modelling of Antennas
PublicationData-driven surrogate modelling of antenna structures is an attractive way of accelerating the design process, in particular, parametric optimization. In practice, construction of surrogates is hindered by curse of dimensionality as well as wide ranges of geometry parameters that need to be covered in order to make the model useful. These difficulties can be alleviated by constrained performance-driven modelling with the surrogate...
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Review of sewage sludge management: standards, regulations and analytical methods
PublicationThis article presents the most popular methods of sewage sludge management and associated unit operations and processes referring to them. The most popular methods are: Reclamation and adaptation of lands to specific needs; plant cultivation not intended for consumption or for production of food; usage in agriculture; usage in building; recovery of phosphorus, rare earth metals or fats and usage in industry; producing combustible...
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The challenge of abandonment for the sustainable management of Palaearctic natural and semi-natural grasslands
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Detonations in hydrogen-methane-air mixtures in semi confined flat channels
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Semi-Markovian models of the process of technical state changes of technical objects.
PublicationNajistotniejszym problemem eksploatacji wszystkich obiektów technicznych (urządzeń) jest problem racjonalnego (a zwłaszcza optymalnego) decyzyjnego sterowania procesem zmian stanów technicznych tych obiektów. Sterowanie takie może być realizowane w przypadku zastosowania między innymi modelu wspomnianego procesu zmian stanów. Mając to na uwadze, w opracowaniu tym przedstawiono formalny opis procesu eksploatacji obiektów technicznych...
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Capturing semantics of semi-structured data using partial-order trees
PublicationW artykule zaprezentowano nowe podejście do problemu klasyfikacji danych semistrukturalnych. Kryteria klasyfikacji bazują na strukturze danych (zwanej typem danych) oraz na ich usytuowaniu w grafir danych (zwanym rolą danych). Zastosowano model OEM (Object Exchange Model) do reprezentacji nazy danych semistrukturalnych. Bazując na tej reprezentacji, definiuje się typy i role obiektów semistrukturalnych i organizuje się je w struktury...
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An efficient approach to optimization of semi‐stable routing in multicommodity flow networks
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Some developments in constitutive modelling of soft clays, Keynote lecture
PublicationPrzedstawiono przegląd najczęściej stosowanych modeli konstytutywnych dla naturalnych gruntów słabonośnych, takich jak: gliny, namuły lub torfy. Skupiono się przede wszystkim na takich elementach charakterystyki mechanicznej gruntów słabonośnych jak: anizotropia, zjawisko pełzania i relaksacji oraz destrukturyzacja. Artykuł jest podsumowaniem 4-letniego projektu badawczego finansowanego w ramach 5 ramowego projektu Unii Europejskiej:...
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Krzysztof Giaro prof. dr hab. inż.
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Modular Approach for Modelling Warming Up Process in Water Installations with Flow-Regulating Elements
PublicationThe paper presents a new method for modelling the warming up process of a water system with elements regulating the flow in a stochastic manner. The paper presents the basic equations describing the work of typical elements which the water installation is composed of. In the proposed method, a new computational algorithm was used in the form of an iterative procedure enabling the use of boundary conditions that can be stochastically...
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Cyclic behaviour modelling of additively manufactured Ti-6Al-4V lattice structures
PublicationThe present work is concerned with the numerical modelling of the cyclic behaviour of Ti-6Al-4V lattice structures. In the study, diamond structures of titanium alloy produced by the additive laser powder bed fusion (LPBF) method with different degrees of relative density were used. Realistic geometric models of the studied mesostructures were generated using computed microtomography, taking into account the imperfections of the...
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FEM-based wave propagation modelling for SHM: Certain numerical issues in 1D structures
PublicationThe numerical modelling of structural elements is an important aspect of modern diagnostic systems. However, the process of numerical implementation requires advanced levels of consideration of multiple aspects. Important issues of that process are the positive and negative aspects of solution applied methods. Therefore the aim of this article is to familiarise the reader with the most important aspects related to the process of...
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Linear viscoelastic modelling of damage-involved structural pounding during earthquakes
PublicationDamage-involved structural pounding during earthquakes has been recently intensively studied using different impact force models. The results of the previous studies indicate that the linear viscoelastic model is relatively simple yet accurate in modelling pounding-involved behaviour of structures during earthquakes. The only shortcoming of the model is a negative value of the pounding force occurring just before separation, which...
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Computational modelling of historic masonry railroad arch bridges
PublicationThe problems encountered during the analyzes of structural response of historic masonry railroad arch bridges are described in this paper. The attention is mainly focused on the stiffness of the masonry arches, their strengths and appropriate estimation of railroad load intensity. Issues related to computational modelling of two, existing, almost 130 years old masonry arch railroad bridges are presented in this context. The main...
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Interaction Between Storm Water Conduit And Surface Flow For Urban Flood Inundation Modelling
PublicationRapid development of urban areas always comes with great side effects. One of them is the occurrence of urban floods. Growth of impervious surfaces in cities leads to increasing run-off values. This together with difficulties connected with sewage modernization in cities marks urban inundations as being one of the most important issues concerning urban water. Accurate prediction of a phenomenon is difficult as it is highly dependent...
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Quality Assurance and Quality Control in the Analytical Chemical Laboratory. A practical approach : Second edition
PublicationThe second edition defines the tools used in QA/QC, especially the application of statistical tools during analytical data treatment. Clearly written and logically organized, it takes a generic approach applicable to any field of analysis. The authors begin with the theory behind quality control systems, then detail validation parameter measurements, the use of statistical tests, counting the margin of error, uncertainty estimation,...
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Rigid finite elements and multibody modelling used in estimation and reduction of rod vibrations
PublicationIn the paper, a mechanical set composed of a robot (manipulator) and of an elastic beam is considered. The beam is fixed to the top of the robot structure. In most of the similar cases, undesired vibrations can be excited in the beam. They are especially significant, when dynamics in the robot braking period is examined. In the paper, estimation and modification of length of the braking period is proposed, in order to reduce the...
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Modelling the loss of time caused by traffic incidents on motorways
PublicationFor each road incident important factors like location, capacity reduction, traffic management, duration of road incidents and amount of traffic should be defined. All performer operations and effects of incidents affect the capacity of the road, average speed, time loss, vehicle queues and traffic jams. In the article road incidents were divided into planned and unexpected. Statistical analysis prepared using the database of traffic...
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Derivation of the scaling laws used in geotechnical centrifuge modelling-application of dimensional analysis and Buckingham Π theorem
PublicationGeotechnical centrifuge modelling has been a world-wide used technology in physical tests. In this paper a derivation of scaling laws by dimensional analysis for the centrifugal modelling is presented. Basic principles of centrifuge modelling are described. Scaling laws for slow events like consolidation and fast events like dynamic loads are shown. The differences in scale factors for both processes are noticed. The aim of this...
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Random field modelling of mechanical behaviour of corroded thin steel plate specimens
PublicationThe objective of this work is to explore the possibility of corrosion degradation modelling of thin steel plate specimens with the use of random field approach. The mechanical properties are obtained via the nonlinear Finite Element Analysis with the use of an explicit dynamic solver. The fully nonlinear material model is adopted to obtain the proper stress-strain response. Sensitivity analysis considering the main statistical...
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Modelling of a medium-term dynamics in a shallow tidal sea, based on combined physical and neural network methods
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Application of theory of semi-Markov processes to determining distribution of probabilistic process of marine accidents resulting from colission of ships
PublicationIn this paper is presented possible application of the theory of semi-Markov processes to elaborating an eight-state model of the process of occurrence of serviceability state and unserviceability states of sea-going ships making critical manoeuvres during their entering and leaving the ports. In the analysis it was taken into account that sea-going ships are in service for a very long time t (t → ∞). The model was elaborated to...
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Experimentation, material modelling and simulation of bonded joints with a flexible adhesive
PublicationThe paper deals with material parameters identification of a flexible adhesive and the numerical simulation of its behaviour in a single lap bonded joint. The material modelling was based on the simple shear and tensile-shear laboratory tests of the bonded joints made of thin aluminium and polyurethane plates with the flexible adhesive Terostat MS 9360 manufactured by Henkel AG & Co. The adhesive was considered as a hyperelastic...
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An analytical four-layer horizontal electric current dipole model for analysing underwater electric potential in shallow seawater
PublicationThe paper presents a new analytical four‑layer (air–water–bottom–non‑conductive layer) horizontal electric dipole model which allows an accurate approximation of ship’s Underwater Electric Potential (UEP) from a sufficient depth in shallow coastal marine waters. The numerical methods, usually Finite Element Method (FEM) or Boundary Elements Method (BEM), are typically used to estimate the electric field and the distribution of...
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Quasi-discrete modelling of PMSM phase currents in drives with low switching-to-fundamental frequency ratio
PublicationThis study proposes a new quasi-discrete approach to modelling the permanent magnet synchronous motor (PMSM). The quasi-discrete modelling reflects the impact of continuous rotor movement, which takes place during a control cycle, on the shape of motor current waveforms. This provides much improvement in current modelling accuracy under inverter low switching-to-fundamental frequency operation. The proposed approach may be used...