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Search results for: TWO-DIMENSIONAL%20GAS%20CHROMATOGRAPHY
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On-line Search in Two-Dimensional Environment
PublicationWe consider the following on-line pursuit-evasion problem. A team of mobile agents called searchers starts at an arbitrary node of an unknown network. Their goal is to execute a search strategy that guarantees capturing a fast and invisible intruder regardless of its movements using as few searchers as possible. As a way of modeling two-dimensional shapes, we restrict our attention to networks that are embedded into partial grids:...
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Two-dimensional gas chromatography – principles and application in fruits analysis
PublicationTwo-dimensional gas chromatography is a rapidly developing analytical technique. One of the major uses of this technique is its use for food analysis. The paper presents the principle of operation and history of this analytical technique. The specification of the two-dimensional gas chromatography technique has been discussed. The principles of separation of ingredients and application of the method, particularly in the analysis...
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On exact two-dimensional kinematics for the branching shells
PublicationWe construct the two-dimensional (2D) kinematics which is work-conjugate to the exact 2D local equilibrium conditions of the non-linear theory of branching shells. It is shown that the compatible shell displacements consist of the translation vector and rotation tensor fields defined on the regular parts of the shell base surface as well as independently on the singular surface curve modelling the shell branching. Several characteristic...
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On the correspondence between two- and three-dimensional Eshelby tensors
PublicationWe consider both three-dimensional (3D) and two-dimensional (2D) Eshelby tensors known also as energy–momentum tensors or chemical potential tensors, which are introduced within the nonlinear elasticity and the resultant nonlinear shell theory, respectively. We demonstrate that 2D Eshelby tensor is introduced earlier directly using 2D constitutive equations of nonlinear shells and can be derived also using the throughthe-thickness...
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On-line Search in Two-Dimensional Environment
PublicationWe consider the following on-line pursuit-evasion problem. A team of mobile agents called searchers starts at an arbitrary node of an unknown network. Their goal is to execute a search strategy that guarantees capturing a fast and invisible intruder regardless of its movements using as few searchers as possible. We require that the strategy is connected and monotone, that is, at each point of the execution the part of the graph...
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Numerical Solution of the Two-Dimensional Richards Equation Using Alternate Splitting Methods for Dimensional Decomposition
PublicationResearch on seepage flow in the vadose zone has largely been driven by engineering and environmental problems affecting many fields of geotechnics, hydrology, and agricultural science. Mathematical modeling of the subsurface flow under unsaturated conditions is an essential part of water resource management and planning. In order to determine such subsurface flow, the two-dimensional (2D) Richards equation can be used. However,...
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Relativistic two-dimensional hydrogen-like atom in a weak magnetic field
PublicationA two-dimensional (2D) hydrogen-like atom with a relativistic Dirac electron, placed in a weak, static, uniform magnetic field perpendicular to the atomic plane, is considered. Closed forms of the first- and second-order Zeeman corrections to energy levels are calculated analytically, within the framework of the Rayleigh–Schrödinger perturbation theory, for an arbitrary electronic bound state. The second-order calculations are...
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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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Two-dimensional hydrogen-like atom in a weak magnetic field
PublicationWe consider a non-relativistic two-dimensional (2D) hydrogen-like atom in a weak, static, uniform magnetic field perpendicular to the atomic plane. Within the framework of the Rayleigh-Schr¨odinger perturbation theory, using the Sturmian expansion of the generalized radial Coulomb Green function, we derive explicit analytical expressions for corrections to an arbitrary planar hydrogenic bound-state energy level, up to the fourth...
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A Comparison of Simplified Two-dimensional Flow Models Exemplified by Water Flow in a Cavern
PublicationThe paper shows the results of a comparison of simplified models describing a two-dimensional water flow in the example of a water flow through a straight channel sector with a cavern. The following models were tested: the two-dimensional potential flow model, the Stokes model and the Navier-Stokes model. In order to solve the first two, the boundary element method was employed, whereas to solve the Navier-Stokes equations, the...
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On analytical solution of stationary two dimensional boundary problem of natural convection
PublicationApproximate analytical solution of two dimensional problem for sta- tionary Navier-Stokes, continuity and Fourier-Kirchho equations describ- ing free convective heat transfer from isothermal surface of half innite vertical plate is presented. The problem formulation is based on the typ- ical for natural convection assumptions: the uid noncompressibility and Boussinesq approximation. We also assume that orthogonal to the plate component...
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Topological-numerical analysis of a two-dimensional discrete neuron model
PublicationWe conduct computer-assisted analysis of a two-dimensional model of a neuron introduced by Chialvo in 1995 [Chaos, Solitons Fractals 5, 461–479]. We apply the method of rigorous analysis of global dynamics based on a set-oriented topological approach, introduced by Arai et al. in 2009 [SIAM J. Appl. Dyn. Syst. 8, 757–789] and improved and expanded afterward. Additionally, we introduce a new algorithm to analyze the return times...
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Modeling of the Two-Dimensional Flow Caused by Sea Conditions and Wind Stresses on the Example of Dead Vistula
PublicationThe article presents the results of two-dimensional modeling of flows caused by the sea conditions and wind stresses on the example of Dead Vistula. Based on the available bathymetric data, a numerical model of the river section was created, which was supplemented with data on the position of the water table depending on hydrometeorological conditions. To describe the flow field in steady conditions, a simplified model of two-dimensional...
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Two-Dimensional Gas Chromatography Coupled With Mass Spectrometry in Food Analysis
PublicationThe development of instrumental analytical techniques provided the opportunity for in-depth characterization of many food matrices. In particular, the use of gas chromatography coupled with mass spectrometry gives impressive results in terms of quality and authenticity testing, conducting food freshness evaluations and contamination assessments. A new variant of gas chromatography, namely two-dimensional gas chromatography (GC...
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Application of the Boundary Element Method for the Simulation of Two-dimensional Viscous Incompressible Flow
PublicationThe paper presents the application of an indirect variant of the boundary element method (BEM) to solve the two-dimensional steady flow of a Stokes liquid. In the BEM, a system of differential equations is transformed into integral equations. Thi smakes it possible to limit discretization to the border of the solution. Numerical discretization of the computational domain was performed with linear boundary elements, for which a...
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Bistability in a One-Dimensional Model of a Two-Predators-One-Prey Population Dynamics System
PublicationIn this paper, we study a classical two-predators-one-prey model. The classical model described by a system of three ordinary differential equations can be reduced to a one-dimensional bimodalmap. We prove that this map has at most two stable periodic orbits. Besides, we describe the bifurcation structure of the map. Finally, we describe a mechanism that leads to bistable regimes. Taking this mechanism into account, one can easily...
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Implementation of the Boundary Element Method to Two-Dimensional Heat Transfer with Thermal Bridge Effects
PublicationThe work presents an application of the boundary element method applied to a two-dimensional conductive heat transfer. The algorithm of the method is explained and its advantages are outlined. Green's function as a fundamental solution for Poisson's equation in two dimensions was used and the direct approach was applied. The presented results concern building construction elements as typical cases of thermal bridges. Some properties...
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Comprehensive two-dimensional gas chromatography - promising technique for analysis of complex food matrices
PublicationThe present paper is focused on brief description of operational principle of comprehensive two-dimensional gas chromatography (GC×GC) technique, instrumentation and data processing. Furthermore, the examples of application in the field of food analysis, performed also in the author's laboratory, are given. The detailed discussion of GC×GC characterization and comparison of the volatile composition of berries of different blue...
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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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Two- and three-dimensional elastic networks with rigid junctions: modeling within the theory of micropolar shells and solids
PublicationFor two- and three-dimensional elastic structures made of families of flexible elastic fibers undergoing finite deformations, we propose homogenized models within the micropolar elasticity. Here we restrict ourselves to networks with rigid connections between fibers. In other words, we assume that the fibers keep their orthogonality during deformation. Starting from a fiber as the basic structured element modeled by the Cosserat...
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Two dimensional inverse solution for diagonal pumps
PublicationW pracy przedstawiono rozwiązanie zadania odwrotnego dla wirnika i kierownicy pompy diagonalnej. Dla założonego kształtu powierzchni prądu wyznaczono kształt łopatek obu palisad. Geometria kanałów łopatkowych została wyznaczona w wyniku rozwiązania układu równań zapisanych w krzywoliniowym układzie współrzędnych. W pracy przedstawiono fotografie wirnika wykonanego techniką Rapid Prototyping.
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Quasi-exact solutions for two interacting electrons in two-dimensional anisotropic dots
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Comprehensive two-dimensional gas chromatography for determination of the terpenes profile of blue honeysuckle berries
PublicationTerpenes are the main group of secondary metabolites, which play essential role in human. The establishment of the terpenes profile of berries of different blue honeysuckle cultivars was achieved by headspace solid-phase microextraction coupled with comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (HS-SPME/GCGC-TOFMS). The berries were found to contain 44 terpenes identified by GCGC-TOFMS....
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Second-order Stark effect and polarizability of a relativistic two-dimensional hydrogenlike atom in the ground state
PublicationThe second-order Stark effect for a planar Dirac one-electron atom in the ground state is analyzed within the framework of the Rayleigh-Schrödinger perturbation theory, with the use of the Sturmian series expansion of the generalized Dirac-Coulomb Green's function. A closed-form analytical expression for the static dipole polarizability of that system is found. The formula involves the generalized hypergeometric function ${}_{3}F_{2}$...
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Two-Boson Correlations in Various One-Dimensional Traps
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Two-dimensional vertical analysis of dam-break flow
PublicationW artykule przedstawiono matematyczne modelowanie przepływów ze swobodną powierzchnią w kanałach otwartych. Do symulacji przepływu użyto dwuwymiarowy pionowy model RANS. Wchodzące w skład modelu równania Naviera-Stokesa rozwiązano stosując algorytm SIMPLE dla metody różnic skończonych. Do śledzenia zmian swobodnego zwierciadła wody zastosowano metodę MAC. Analizie poddano szybkozmienny przepływ po poziomym, gładkim dnie wywołany...
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Two dimensional inverse method of turbomachinery stage design
PublicationW artykule przedstawion rys historyczny dotyczący modelu osiowo-symetrycznego w zastosowaniu do maszyn wirnikowych. Została sformułowana metoda rozwiązywania zadania odwrotnego polegaająca na znajdywaniu powierzchni będfącej obrazem łopatki w osiowo symetrycznym modelu maszyny wirnikowej. Zaprezentowano przykłady zastosowania tej metody w odniesieniu do łopatki kierowniczej turbiny, spreżarki promieniowej oraz pompo-turbiny.
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Impact of the Finite Element Mesh Structure on the Solution Accuracy of a Two-Dimensional Kinematic Wave Equation
PublicationThe paper presents the influence of the finite element mesh structure on the accuracy of the numerical solution of a two-dimensional linear kinematic wave equation. This equation was solved using a two-level scheme for time integration and a modified finite element method with triangular elements for space discretization. The accuracy analysis of the applied scheme was performed using a modified equation method for three different...
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Authenticity Assessment of the "Onisiówka" Nalewka Liqueurs Using Two-Dimensional Gas Chromatography and Sensory Evaluation
PublicationThe “Onisiówka” nalewka liqueur is a regional Polish alcoholic beverage, which is inscribed on the list of regional and traditional products of the Ministry of Agriculture and Rural Development in Poland. It is produced from multiflower honey, black elderberry flower syrup, and spirit. Due to fact that the “Onisiówka” nalewka liqueur has never been investigated, these studies are the foundation for further work on this regional...
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Identification of pollutants at the adjacent areas to the landfill site using two dimensional gas chromatography with mass spectrometry technique
PublicationMunicipal landfills are considered one of the main sources of air pollutants. In this article is presented the use of a modern analytical technique: a two dimensional gas chromatography to identify the substances in the atmospheric air near a waste processing plant located in Gdansk. In order to determine the types of substances occurring in different atmospheric conditions, the study was conducted from February to April 2016....
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Ionic liquid as morphology-directing agent of two-dimensional Bi2WO6: New insight into photocatalytic and antibacterial activity
PublicationAn efficient and durable utilization of light to drive photocatalytic reactions still requires the overcoming of barriers. Herein, two-dimensional (2D) ultrathin IL_Bi2WO6 (IL_BWO) photocatalysts were prepared for the first time via ionic liquid-assisted hydrothermal route by adjusting the amount of tetrabutylammonium chloride [TBA][Cl], synthesis temperature and duration. IL played the role of morphology-directing agent given...
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Conductivity of two-dimensional composites with randomly distributed elliptical inclusions
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Two-dimensional rotation-symmetric number-conserving cellular automata
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Two-dimensional thermoluminescence method for checking LiF crystals homogeneity
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The numerical simulation of two-dimensional vertical incompressible viscous flow
PublicationW artykule przedstawiono numeryczne symulacje płaskiego pionowego przepływu nieściśliwej cieczy lepkiej ze swobodną powierzchnią. Zastosowano model bazujący na rozwiązaniu równań Naviera-Stokesa metodą "ciśnień" (SIMPLE). Przy takim podejściu otrzymano dywergencję równań Naviera-Stokesa oraz równanie Poissona na ciśnienie. W rozwiązaniu zastosowano schemat Laxa-Wendroffa z przesuniętą siatką Eulera. Takie podejście zapewnia dokładność...
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Application of two-dimensional intensity maps in high-accuracy polarimetry
PublicationWe propose the analysis of 2D intensity contour maps which is based on the optical transmission function for the polarizer-specimen-analyzer system. A small modification of the high-accuracy universal polarimeter (HAUP) technique was used to measure the intensity maps (HAUP maps) and determine the phase retardation, linear dichroism (LD) parameters, and multiple light reflection contribution in uniaxial crystals. We have performed...
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Two-dimensional simulations of concrete fracture at aggregate level with cohesive elements based on X-ray lCT images
PublicationThe paper presents results of two-dimensional meso-scale simulations of fracture in notched concrete beams subjected to three-point bending test. Concrete was assumed as a 4-phase material composed of aggregate grains placed in the cement matrix, interfacial transitional zones (ITZs) and macro-voids. The particle distribution was taken from real concrete beams on the basis of X-ray lCT images. Comprehensive numerical analyses were carried...
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Exactly solvable model of two interacting Rydberg-dressed atoms confined in a two-dimensional harmonic trap
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Conformational Studies of Two Bradykinin Antagonists by Using Two-dimensional NMR Techniques and Molecular Dynamics Simulations
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Comprehensive two-dimensional gas chromatography and three-dimensional fluorometry for detection of volatile and bioactive substances in some berries
PublicationThe volatilefractionsofCapegooseberryandblueberryweredeterminedbyheadspacesolid-phase microextractioncoupledwithcomprehensivetwo-dimensionalgaschromatographywithtime-of-flight mass spectrometry(HS-SPME/GCGC-TOFMS).Thehighestamountofalcohol(51.8%),ester(32.8%)and carboxylicacid(6.9%)wasinblueberryincomparisonwithgooseberryandoppositelyketones(14.7%), aldehydes(9.9%)andterpenes(8%)werefoundingooseberry.Thebioactivecompoundsandantioxidant capacities...
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Path components of the space of gradient vector fields on the two dimensional disc
PublicationWe present a short proof that if two gradient maps on the twodimensional disc have the same degree, then they are gradient homotopic.
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A New Type of Macro-Elements for Efficient Two-Dimensional FEM Analysis
PublicationThis letter deals with a model order reduction technique applicable for driven and eigenvalue problems solved using the finite element method (FEM). It allows one to efficiently compute electromagnetic parameters of structures comprising small features that require strong local mesh refinement. The subdomains of very fine mesh are separated from the global domain as so called macro-elements that undergo model reduction. The macro-elements...
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The homotopy type of the space of gradient vector fields on the two-dimensional disc
PublicationWe prove that the inclusion of the space of gradient vector fields into the space of all vector fields on D^2 non-vanishing in S^1 is a homotopy equivalence
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Numerical Simulation of two dimensional flow past a bridge cross section
PublicationThis work presents some numerical results concerning application of CFD in civil engineering problems. Selected theoretical aspects of fluid mechanics are elucidated. In the second part of the paper a cross section of upper footbridge of the Bella Sky Hotel in Copenhagen is analysed numerically in the field of wind action.
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Two dimensional modelling of the flood zones in the Vistula river valley in Warsaw
PublicationW artykule przedstawiono opis metodyki wyznaczania stref zalewu powodziowego na terenach miejskich. Rozprzestrzenianie się zalewu symulowano przy pomocy dwuwymiarowych równań de Saint-Venanta. Zasięg zalewu i strefy zagrożenia powodziowego przedstawiono w systemie GIS. Wykonano analizę zagrożenia powodziowego w dolinie Wisły w Warszawie.
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Enantioselective comprehensive two-dimensional gas chromatography of lavender essential oil
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Path components of the space of gradient vector fields on the two-dimensional disc
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Doped Two-Dimensional Silicon Nanostructures as a Platform for Next-Generation Sensors
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Damage detection in rectangular plates by continuous two-dimensional wavelet transform
PublicationPraca opisuje zastosowanie dwuwymiarowej transformaty falkowej do detekcji i lokalizacji uszkodzeń w konstrukcji płytowej. Defekt zlokalizowano na podstawie postaci drgań z symulacji numerycznych oraz z badań eksperymentalnych.
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Two-dimensional gel-based serum protein profile of growing piglets
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