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Elastic distortional buckling of thin-walled bars of closed quadratic cross-section
PublicationIn this study a tin-walled bar with closed quadratic cross-section is considered. The elastic stability of axially compressed bar related to the cross-section distortion is investigated. The governing differential equatio is derived with aid of the principle of stationary potential energy. The critical load for simply supported bar is found in an analytical form and it is copared with the FEM solution. Sufficient accuracy of the...
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QoS Extensions for Flow-Awareness Networks
PublicationThe paper contains a description and research results of the proposal for distributed QoS extensions for Flow-Based Networking. These QoS extensions let the network accept or reject flows based on current network load and QoS promises for each of the flows. Proposed solution consists of two distributed components, each of them performing in every node, measurement system and access control. The solution could be applied in any...
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Enzymatic cross-linking of β-lactoglobulin in solution and at air–water interface: Structural constraints
PublicationEffective and controlled use of cross-linking enzymes in structure engineering of food systems depends on characterization of the favorable conditions for enzyme-substrate complex and the limiting factors for the desired modification. In this respect, we analyzed the susceptibility of bovine β-lactoglobulin (BLG) to enzymatic cross-linking by Trichoderma reesei tyrosinase (TrTyr) and transglutaminase (TG). Changes in BLG molecular...
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Mitigation of the Flow Maldistribution in Minichannel and Minigap Heat Exchangers by Introducing Threshold in the Manifolds
PublicationIn the present paper, a detailed numerical investigation has been carried out to analyze the flow maldistribution in 50 parallel rectangular cross-section (1 mm depth and 1 mm width) minichannels and minigap section (1 mm depth and 99 mm width) with rectangular/trapezoidal manifolds in Z-type flow configuration. The author carried out numerical investigation with various mass flowrates, namely 0.05 kg/s, 0.1 kg/s and 0.2 kg/s which...
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Electron-impact dissociation of molecular hydrogen: benchmark cross sections
PublicationWe present a joint experimental and theoretical investigation of a fundamental process in atomic and molecular physics: electron impact excitation of molecular hydrogen’s (H2) most dominant transition (X1Σg+ → b3Σu+). Excitation of this state is by far the main channel that causes the dissociation of H2 into H + H atoms at low energies. The Convergent Close-Coupling (CCC) calculations predicted significant, more than factor of...
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Cross sections calculations for electron scattering from dimethylamine, NH(CH3)2, molecule
PublicationThe total cross section for single electron-impact ionization and the integral elastic cross section for electron scattering from dimethylamine have been calculated using the binary-encounter-Bethe model and the independent atom method, respectively.
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Impact of Energy Slope Averaging Methods on Numerical Solution of 1D Steady Gradually Varied Flow
PublicationIn this paper, energy slope averaging in the one-dimensional steady gradually varied flow model is considered. For this purpose, different methods of averaging the energy slope between cross-sections are used. The most popular are arithmetic, geometric, harmonic and hydraulic means. However, from the formal viewpoint, the application of different averaging formulas results in different numerical integration formulas. This study...
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Electron-scattering cross sections for selected alkyne molecules: Measurements and calculations
PublicationWe report cross-section results from experimental and theoretical studies on electron collisions with 1-butyne (HC≡C–CH2CH3) and acetylene (HC≡CH) molecules and from computations for a propyne (HC≡C–CH3) molecule. Absolute grand -total electron-scattering cross sections (TCSs) were measured at impact energies ranging from about 0.5 to 300 eV using the linear electron-transmission method. The TCS energy curve for 1-butyne has a...
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A Cross-Polarisation Discrimination Analysis of Off-Body Channels in Passenger Ferryboat Environments
PublicationThere is a need for investigating radio channels for Body Area Networks considering the depolarisation phenomenon and new types of environments, since these aspects are becoming very important for systems design and deployment. This paper presents an analysis of cross-polarisation discrimination for off-body channels based on a measurement campaign performed in a passenger ferryboat, i.e., where all walls, floors and ceilings are...
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Obtaining a Well-Trained Artificial Intelligence Algorithm from Cross-Validation in Endoscopy
PublicationThe article shortly discusses endoscopic video analysis problems and artificial intelligence algorithms supporting it. The most common method of efficiency testing of these algorithms is to perform intensive cross-validation. This allows for accurately evaluate their performance of generalization. One of the main problems of this procedure is that there is no simple and universal way of obtaining a specific instance of a well-trained...
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Pawlak's flow graph extensions for video surveillance systems
PublicationThe idea of the Pawlak's flow graphs is applicable to many problems in various fields related to decision algorithms or data mining. The flow graphs can be used also in the video surveillance systems. Especially in distributed multi-camera systems which are problematic to be handled by human operators because of their limited perception. In such systems automated video analysis needs to be implemented. Important part of this analysis...
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Cross-cultural Communication
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Cross-cultural Communication
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Comparison of Polypropylene and Ceramic Microfiltration Membranes Applied for Separation of 1,3-PD Fermentation Broths and Saccharomyces cerevisiae Yeast Suspensions
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Flow maldistribution and its mitigation in mini heat exchangers
PublicationIn the present paper, a detailed numerical investigation has been carried out to analyze the flow maldistribution in 50 parallel 1 mm x 1 mm rectangular minichannels and 1 mm depth minigap section with rectangular, trapezoidal, triangular or concave mani-folds in Z-type flow configuration (16 different cases). The working medium was ethanol and the mass flow rate was 5×10-4 kg/s. Both sections was heated from the bottom side. Heat...
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Absolute Photoabsorption Cross-Sections of Methanol for Terrestrial and Astrophysical Relevance
PublicationWe investigate the methanol absorption spectrum in the range 5.5–10.8 eV to provide accurate and absolute cross-sections values. The main goal of this study is to provide a comprehensive analysis of methanol electronic-state spectroscopy by employing high-resolution vacuum ultraviolet (VUV) photoabsorption measurements together with state-of-the-art quantum chemical calculation methods. The VUV spectrum reveals several new features...
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Comparative study of flow condensation in conventional and small diameter tubes
PublicationFlow boiling and flow condensation are often regarded as two opposite or symetrical phenomena. Their description however with a single correlation has yet to be suggested.In the case of flow boiling in minichannels there is mostly encountered the annular flow structure, where the buble generetion is not present. Similar picture holds for the case of inside tube condensation, where annular flow structure predominates. In such case...
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Influence of the presence of rhamnolipids and ionic cross-linking conditions on the mechanical properties of alginate hydrogels.
Open Research DataThe dataset contains the results of determination the effect of rhamnolipids concentration, calcium chloride concentration and ionic cross-linking time on the mechanical properties of alginate hydrogels prepared by immersing the alginate mixture limited by the dialysis membrane in an appropriate cross-linking solution containing calcium ions. The mechanical...
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CFD Simulations and Tests of a Prototype Flow Control Valve
PublicationIn this paper a prototype of a flow control valve is described and numerically simulated. The flow control valve is used in hydraulic systems to maintain constant fluid flow despite changing loads of a receiver. The standard construction of this type of valves is modified mainly by eliminating the spring. The prototype consists the hydrostatically unloaded throttle valve and pressure ratio valve substituting pressure difference...
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The equivariant spectral flow and bifurcation of periodic solutions of Hamiltonian systems
PublicationWe define a spectral flow for paths of selfadjoint Fredholm operators that are equivariant under the orthogonal action of a compact Lie group as an element of the representation ring of the latter. This G-equivariant spectral flow shares all common properties of the integer valued classical spectral flow, and it can be non-trivial even if the classical spectral flow vanishes. Our main theorem uses the G-equivariant spectral flow...
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A Study of Cross-Linguistic Speech Emotion Recognition Based on 2D Feature Spaces
PublicationIn this research, a study of cross-linguistic speech emotion recognition is performed. For this purpose, emotional data of different languages (English, Lithuanian, German, Spanish, Serbian, and Polish) are collected, resulting in a cross-linguistic speech emotion dataset with the size of more than 10.000 emotional utterances. Despite the bi-modal character of the databases gathered, our focus is on the acoustic representation...
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Total cross section measurements for electron scattering from tin(IV) chloride (SnCl4)
PublicationTotal cross section for electron scattering from SnCl4 molecules has been measured for energies from 0.6 to 300 eV. Obtained results have been compared with total cross sections for electron scattering from other tetrachloride molecules: XCl4 where X=C, Si, Ge.
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Flow of liquid in flat gaps of the satellite motor working mechanism
PublicationThe article describes the methodology and results of investigations of the flow of oil and HFA-E emulsion in flat gaps of the working mechanism of a satellite motor. The flow of liquid in those gaps is turbulent and not fully developed. The article presents two methods of modelling this flow. Method I makes use of the Darcy-Weisbach formula, while Method II bases on the assumption that in the variable-length gaps the flow is turbulent...
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Electron scattering cross sections for 1-pentene, H2C=CH-(CH2)2CH3, molecules
PublicationCross sections, both experimental and theoretical, are reported for electron scattering from 1-pentene (C5H10) molecules. Absolute grand-total cross sections (TCSs) were measured at electron impact energies ranging from 1 to 300 eV, using a linear electron-transmission technique. The dominant behaviour of the experimental TCS energy function is a distinct asymmetric enhancement with the maximum located around 6.5 eV. Discernible...
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Enzymatic and Chemical Cross-Linking of Bacterial Cellulose/Fish Collagen Composites—A Comparative Study
PublicationThis article compares the properties of bacterial cellulose/fish collagen composites (BC/Col) after enzymatic and chemical cross-linking. In our methodology, two transglutaminases are used for enzymatic cross-linking—one recommended for the meat and the other proposed for the fish industry—and pre-oxidated BC (oxBC) is used for chemical cross-linking. The structure of the obtained composites is characterized by scanning electron...
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TOTAL CROSS SECTIONS FOR ELECTRON SCATTERING FROM SELECTED HYDROCARBONS: THE SUBSTITUTIONAL AND ADDITIVITY EFFECTS
PublicationTotal cross sections (TCS) for electron scattering from selected alkyne molecules, ethylene and its derivatives are compared. All cross sections have been measured in a wide energy range, from about 1 eV up to 370 eV, with the same electrostatic electron spectrometer. The substitutional and additivity effects are indicated and discussed.
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Modeling lubricant flow between thrust-bearing pads
PublicationInlet temperature is one of the main inputs in all models for the analysis of fluid film bearing performance. At the same time, inlettemperature distribution and also oil velocity distribution at the inlet are the result of flow phenomena in the gap between the bearingpads. These phenomena are complex and in many cases further affected by any special arrangements of forced oil supply to the gapbetween pads. The reason for such...
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SDN testbed for validation of cross-layer data-centric security policies
PublicationSoftware-defined networks offer a promising framework for the implementation of cross-layer data-centric security policies in military systems. An important aspect of the design process for such advanced security solutions is the thorough experimental assessment and validation of proposed technical concepts prior to their deployment in operational military systems. In this paper, we describe an OpenFlow-based testbed, which was...
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Influence of the air phase on water flow in dikes
PublicationNumerical models are often used to describe flow and deformation processes occurring in dikes during flood events. Modeling of such phenomena is a challenging task, due to the complexity of the system, consisting of three material phases: soil skeleton, pore water and pore air. Additional difficulties are transient loading caused by variable in time water levels, heterogeneity of the soil or air...
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Experimental study on the seepage flow through the ice jam
PublicationIn light of the observed climate change, there is a need for better understanding of river ice processes for managing water resources in the cold regions. Ice jams produce significant resistance which may cause rise of water level and flooding. The jam resistance is only referred to the roughness of its underside, and this approach lead to exceptional roughness coefficients which has no physical explanation. Number of evidences...
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Pressure drop of HFE7000 and HFE7100 during flow condensation in minichannels
PublicationAttention is focused on the issues of flow resistance and pressure drop of perspective refrigeration fluids during condensation in the two-phase flow in minichannels. The case of the flow through a cylindrical single channel of 2.3 mm inner diameter was carefully analyzed. Pressure drop tests have been performed in diabatic flow conditions. The effect of heat flux, mass flux, vapour quality and saturation temperature on the two-phase...
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Measurements of Dispersed Phase Velocity in Two-Phase Flows in Pipelines Using Gamma-Absorption Technique and Phase of the Cross-Spectral Density Function
PublicationThis paper concerns the application of the gamma radiation absorption method in the measurements of dispersed phase velocity in two-phase flows: liquid–gas flow in a horizontal pipe- line and liquid–solid particles in a vertical pipe. Radiometric sets containing two linear 241Am gamma radiation sources and two NaI(Tl) scintillation detectors were used in the research. Due to the stochastic nature of the signals obtained from the...
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PROPERTIES OF ONE DIMENSIONAL OPEN-CHANNEL STEADY FLOW EQUATIONS
PublicationIn this paper properties of discrete forms of one dimensional steady gradually varied flow equations are discussed. Such forms of flow equations are obtained as a result of approximation of their differential forms, which is required to solve them numerically. For such purpose explicit or implicit numerical approximation schemes for ordinary differential equations can be applied. It turns out that dependently on the chosen approximation...
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Free-surface elevation in open vortex flow controls
PublicationRotational form of fluid motion is complex, but very important in science and technology. The paper is devoted to the hydraulic mechanism of flow in open vortex flow controls, or regulators. The velocity field was described by the kinematic model, and intensity of rotation - by means of the energy balance between the input and dissipation. In consequence some algebraic expresions were obtained, which can be useful in approximated...
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DISTRIBUTION OF FLOWS IN A CHANNEL NETWORK UNDER STEADY FLOW CONDITIONS
PublicationThe article presents an algorithm for calculating the distribution of flow in a junction of open channel network under steady flow conditions. The article presents a simplified calculation algorithm used to estimate the distribution of flow in a network of channels under steady flow conditions. The presented algorithm is based on the continuity equation and a simplified energy equation. To describe the relationship between the...
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The logistics streamlining of the material flow at the production company
PublicationThe main practical problem in the Logistics Department at the company is overstaffing in the unit responsible for the flow of materials. Carried out by the authors of the article, some detailed research on the process analysis in the discussed company indicates that the main cause of such a situation is related to an increase in the amount of transported material and a lack of redesigning the material flow in...
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Influence of meniscus shape in the cross sectional plane on the knee contact mechanics
PublicationWe present a three dimensional finite element analysis of stress distribution and menisci deformation in the human knee joint. The study is based on the Open Knee model with the geometry of the lateral meniscus which shows some degenerative disorders. The nonlinear analysis of the knee joint under compressive axial load is performed. We present results for intact knee, knee with partial and complete radial posterior meniscus root...
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Steady magnetohydrodynamic flow in a diverging channel with suction or blowing
PublicationAn analysis is made of steady two-dimensional divergent flow of an electrically conducting incompressible viscous fluid in a channel formed by two non-parallel walls, the flow being caused by a source of fluid volume at the intersection of the walls. The fluid is permeated by a magnetic field produced by an electric current along the line of intersection of the channel walls. The walls are porous and subjected to either suction...
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Comparative study of flow condensation in conventional and small diameter tubes
PublicationFlow boiling and flow condensation are often regarded as two opposite or symmetrical phenomena, however their description with a single correlation has yet to be suggested. In the case of flow boiling in minichannels there is mostly encountered the annular flow structure, where the bubble generation is not present. Similar picture holds for the case of inside tube condensation, where annular flow structure predominates. In such...
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Kinetics of cross-linking processes of fast-curing polyurethane system
PublicationThis work focuses on the application of thermal analysis and kinetics investigations to analyze chemical processes during cross-linking of the complex fast-curing polyurethane system. Non-isothermal Differential Scanning Calorimetry (DSC) measurements were performed for both stoichiometric mixtures of polyol and isocyanate component and for mixture with large isocyanate excess. Isoconversional methods were used to calculate initial...
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Recent progress in experimental studies of electrohydrodynamic flow in electrostatic precipitators
PublicationMany experimental, theoretical and numerical works were devoted to the electrohydrodynamic (EHD) flow generated in electrostatic precipitators (EPSs). The generally accepted conclusion from these studies is that the EHD flow plays an important role in the particle collection in ESPs. However, despite of the recent fast progress in numerical simulation and experimental techniques used in the ESPs studies many problems related to...
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ANYTIME POLYNOMIAL HEURISTIC ALGORITHM FOR PARTITIONING GROUPS OF DATA WITH PRESERVING CLASS PROPORTIONS FOR CROSS-VALIDATION
PublicationThe article describes a problem of splitting data for k-fold cross-validation, where class proportions must be preserved, with additional constraint that data is divided into groups that cannot be split into different cross-validation sets. This problem often occurs in e.g. medical data processing, where data samples from one patient must be included in the same cross-validation set. As this problem is NP-complete, a heuristic...
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Joint experimental and theoretical study on low-energy elastic electron scattering by gaseous alkynes: Differential cross sections, shape resonances, and methylation effects
PublicationA detailed comparison of experimental and theoretical elastic cross sections for low-energy electron scattering by ethyne, taken earlier in our group by Gauf et al. [Phys. Rev. A 87, 012710 (2013)], and some of its methylated derivatives, propyne, and the isomers 1-butyne and 2-butyne, taken here, are presented. The present differential cross sections were measured at incident electron energies ranging from 1 eV to 30 eV and...
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Selected aspects of two-phase flow studies using different visualization techniques in minichannels
PublicationThe subject of the study is to present the possibility of the use of visualization techniques in the researches on two-phase flows, carried out by the authors for many years. These works included as follows: heat transfer during the flow boiling, boiling crises and condensation in flow. The issue of the heat transfer intensification during the flow boiling through the channels of small diameters was analyzed. All this work focused...
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Numerical solutions for blood flow in elastic vessels
PublicationWe consider the differential–algebraic system for the blood flow and pressure in the systemic arteries. By the operator splitting method, we transform the system into the hyperbolic one, introduce the bicharacteristics, and perform the time–space nonuniform discretization, obtaining the innovative difference scheme. Our results are illustrated with numerical experiments.
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EVALUATION OF LIQUID-GAS FLOW IN PIPELINE USING GAMMA-RAY ABSORPTION TECHNIQUE AND ADVANCED SIGNAL PROCESSING
PublicationLiquid-gas flows in pipelines appear in many industrial processes, e.g. in the nuclear, mining, and oil industry. The gamma-absorption technique is one of the methods that can be successfully applied to study such flows. This paper presents the use of thegamma-absorption method to determine the water-air flow parameters in a horizontal pipeline. Three flow types were studied in this work: plug, transitional plug-bubble,...
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Description of the silo flow and bulk solid pulsations detection using ECT
PublicationW artykule przedstawiono wyniki zastosowania tomografii pojemnościowej do analizy pulsacji występujących w bezkohezyjnym materiale sypkim podczas opróżniania silosu cylindrycznego. Przeanalizowano wpływ parametrów zmiennych (zagęszczenia początkowego, szorstkości ściany, prędkości opróżniania) na wielkość dynamicznych pulsacji)
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Two-phase flow structure assessment based on dynamic image analysis
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Modelling of blood flow: from macro to microscales
PublicationThe aim of this paper it to review various scale approaches to blood flow modelling. Blood motion may be described by three types of mathematical models according to the observed scales or resolutions, namely microscopic, mesoscopic and macroscopic description. The above approaches are discussed together with their advantages and disadvantages. Several results of mesoscopic simulations are presented.
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A System for Cooling Electronic Elements with EHD Coolant Flow
PublicationA system for cooling electronic components where the liquid coolant flow is forced with ion-drag type EHD micropumps was tested.