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Modeling a Traffic Remapping Attack Game in a Multi-hop Ad Hoc Network
PublicationIn multi-hop ad hoc networks, selfish nodes may unduly acquire high quality of service (QoS) by assigning higher priority to source packets and lower priority to transit packets. Such traffic remapping attacks (TRAs) are cheap to launch, impossible to prevent, hard to detect, and harmful to non-selfish nodes. While studied mostly in single-hop wireless network settings, TRAs have resisted analysis in multi-hop settings. In this paper...
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The nonlinear effects of sound in a liquid with relaxation losses
PublicationThe nonlinear effects of sound in electrolyte with a chemical reaction are examined. The dynamic equations that govern non-wave modes in the field of intense sound are derived, and acoustic forces of vortex, entropy, and relaxation modes are determined in the cases of low-frequency sound and high-frequency sound. The difference in the nonlinear effects of sound in electrolyte and in a gas with excited vibrational degrees of molecules,...
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Application of Multivariate Adaptive Regression Splines (MARSplines) Methodology for Screening of Dicarboxylic Acids Cocrystal Using 1D and 2D Molecular Descriptors
PublicationDicarboxylic acids (DiAs) are probably one of the most popular cocrystals formers. Due to the high hydrophilicity and non-toxicity, they are promising solubilizes of active pharmaceutical ingredients (APIs). Although DiAs appear to be highly capable of forming multicomponent crystals with various compounds, some systems reported in the literature are physical mixtures the solid state without forming stable intermolecular complex....
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Identyfikacja trajektorii obiektów dynamicznych w przestrzeni kartezjańskiej na podstawie informacji z wielu estymatorów stanu
PublicationW rozprawie przedstawiono metodologię umożliwiającą implementację rozproszonego asynchronicznego systemu wyznaczania trajektorii. System tego typu jest złożony ze zbioru tzw. węzłów (estymatorów lokalnych), które komunikują się ze sobą. Każdy węzeł wyznacza trajektorię obserwowanego obiektu/procesu na podstawie dwóch zbiorów danych. Pierwszym zbiorem są pomiary dostarczane przez skojarzone z danym...
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Nodal cooperation equilibrium analysis in multi-hop wireless ad hoc networks with a reputation system
PublicationMotivated by the concerns of cooperation security, this work examines selected principles of state-of-the-art reputation systems for multi-hop ad hoc networks and their impact upon optimal strategies for rational nodes. An analytic framework is proposed and used for identification of effective cooperation-enforcement schemes. It is pointed out that optimum rather than high reputation can be expected to be sought by rational nodes.
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Computed vibrational excitation ofCF4by low-energy electrons and positrons: Comparing calculations and experiments
PublicationQuantum calculations for the excitation of the asymmetric modes of the CF4 target gas, ν3 and ν4, by impact of low-energy electrons and positrons are carried out in the energy range around 1 eV and are compared with recent experimental findings. The similarities and differences between the two types of projectiles, and the two different modes, are analyzed and discussed vis à vis the present accord with the experimental results.
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Modeling SARS‐CoV‐2 proteins in the CASP‐commons experiment
PublicationCritical Assessment of Structure Prediction (CASP) is an organization aimed at advancing the state of the art in computing protein structure from sequence. In the spring of 2020, CASP launched a community project to compute the structures of the most structurally challenging proteins coded for in the SARS-CoV-2 genome. Forty-seven research groups submitted over 3000 three-dimensional models and 700 sets of accuracy estimates on...
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Wpływ struktur wsparcia na efektywność nauczania języka pisanego w środowisku e-learningowym
PublicationThe process of knowledge and language skills development during an online course can be very effective if student engagement in learning is achieved. This can be attained by introducing general and specific support mechanisms prior to the commencement of the course and during it. The former relates to the technological aspect, that is to familiarizing students with the functionalities of the virtual learning environment they will...
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Flexural behavior of composite structural insulated panels with magnesium oxide board facings
PublicationThe current report is devoted to the flexural analysis of a composite structural insulated panel (CSIP) with magnesium oxide board facings and expanded polystyrene (EPS) core, that was recently introduced to the building industry. An advanced nonlinear FE model was created in the ABAQUS environment, able to simulate the CSIP’s flexural behavior in great detail. An original custom code procedure was developed, which allowed to include...
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A multithreaded CUDA and OpenMP based power‐aware programming framework for multi‐node GPU systems
PublicationIn the paper, we have proposed a framework that allows programming a parallel application for a multi-node system, with one or more GPUs per node, using an OpenMP+extended CUDA API. OpenMP is used for launching threads responsible for management of particular GPUs and extended CUDA calls allow to manage CUDA objects, data and launch kernels. The framework hides inter-node MPI communication from the programmer who can benefit from...
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Estimation of wind pressure acting on the new palm house in Gdansk
PublicationThis paper deals with the problem of numerical simulations of wind loads acting on a Palm House with complex geometry. Flow simulations with aid of computational fluid dynamics procedures have been performed to check if the pressure distributions for the structure are greater than those calculated using the standard design codes with assumption that the Palm House horizontal cross sections are described by smooth cylinders.
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Subjective Quality Evaluation of Underground BPL-PLC Voice Communication System
PublicationDesigning a reliable voice transmission system is not a trivial task. Wired media, thanks to their resistance to mechanical damage, seem an ideal solution. The BPL-PLC (Broadband over Power Line – Power Line Communication) cable is resilient to electricity stoppage and partial damage of phase conductors. It maintains continuity of transmission in case of an emergency situation, including paramedic rescue operations. These features...
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Inwestycja w złoto – bezpieczna przystań, zabezpieczenie czy źródło dywersyfikacji dla polskiego inwestora
PublicationW artykule scharakteryzowano pojęcie inwestycji zabezpieczającej, dywersyfikującej oraz inwestycji określanej jako bezpieczna przystań. Celem opracowania jest zbadanie, czy występują powiązania między stopami zwrotu osiąganymi na polskim rynku akcji a stopami zwrotu z inwestycji w złoto. W pracy zweryfikowano hipotezę: stopa zwrotu z inwestycji w złoto spełnia funkcję inwestycji zabezpieczającej w długim okresie w stosunku do inwestycji...
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Nonlinear increase in bubbles radii caused by sound in a bubbly liquid
PublicationThe nonlinear interaction of acoustic and entropy modes in a bubbly liquid is considered. The reasons for interaction are both nonlinearity and dispersion. In the field of intense sound, a decrease in the mixture density is predicted. That corresponds to the well-established growth of bubbles volumes due to rectified diffusion. The nonlinear interaction of modes as a reason for a bubble to grow due to sound, is discovered. The...
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Distinguishing views in symmetric networks: A tight lower bound
PublicationThe view of a node in a port-labeled network is an infinite tree encoding all walks in the network originating from this node. We prove that for any integers n ≥ D ≥ 1, there exists a port-labeled network with at most n nodes and diameter at most D which contains a pair of nodes whose (infinite) views are different, but whose views truncated to depth Omega( D log(n/ D )) are identical.
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Polynomial Algorithm for Minimal (1,2)-Dominating Set in Networks
PublicationDominating sets find application in a variety of networks. A subset of nodes D is a (1,2)-dominating set in a graph G=(V,E) if every node not in D is adjacent to a node in D and is also at most a distance of 2 to another node from D. In networks, (1,2)-dominating sets have a higher fault tolerance and provide a higher reliability of services in case of failure. However, finding such the smallest set is NP-hard. In this paper, we...
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Instantaneous Heating and Cooling Caused by Periodic or Aperiodic Sound of Any Characteristic Duration in a Gas with Vibrational Relaxation
PublicationThermodynamic relaxation of internal degrees of a molecule's freedom in a gas occurs with some characteristic time. This makes wave processes in a gas behave differently depending on the ratio of characteristic duration of perturbations and the relaxation time. In particular, generation of the secondary non-wave modes by intense sound in a nonlinear flow dependens on frequency. These kinds of interaction are considered in this...
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Application of Doubly Connected Dominating Sets to Safe Rectangular Smart Grids
PublicationSmart grids, together with the Internet of Things, are considered to be the future of the electric energy world. This is possible through a two-way communication between nodes of the grids and computer processing. It is necessary that the communication is easy and safe, and the distance between a point of demand and supply is short, to reduce the electricity loss. All these requirements should be met at the lowest possible cost....
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All-gather Algorithms Resilient to Imbalanced Process Arrival Patterns
PublicationTwo novel algorithms for the all-gather operation resilient to imbalanced process arrival patterns (PATs) are presented. The first one, Background Disseminated Ring (BDR), is based on the regular parallel ring algorithm often supplied in MPI implementations and exploits an auxiliary background thread for early data exchange from faster processes to accelerate the performed all-gather operation. The other algorithm, Background Sorted...
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Finding safe and efficient shipping routes in ice-covered waters: A framework and a model
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Towards probabilistic models for the prediction of a ship performance in dynamic ice
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Estimating operability of ships in ridged ice fields
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Assessment of the ice jam potential on regulated rivers and reservoirs with the use of numerical model results
PublicationThis study presents an attempt at estimating the jam potential on rivers with significant anthropogenic intervention in the course or flow characteristics of the river. The DynaRiCE model was used for forecasting both the place and time of an ice jam occurrence. In this modified method, two ice parameters are subjected to analysis, namely the relative ice-to-water velocity (vi/vw),and the ice thickness to single floe thickness...
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Failure Analysis of footbridge made of composite materials
PublicationFinite element method analysis of a pedestrian footbridge made of sandwich material is presented. The internal structure of the material is modelled as a structural shell assuming the Equivalent Single Layer approach (ESL). Two FEM commercial codes are employed. The response of the structure is studied in order to determine the load level that activates Hashin and Tsai-Wu failure criteria. Some practical aspects of designing footbridges...
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S’attaquer à la suprématie du masculin sur le féminin : le français inclusif dans les publications des universités françaises dans les réseaux sociaux
PublicationThis paper aims to examine the use of inclusive French in the Internet publications of Paris universities on their social media. Three higher education institutions were selected: Paris Dauphine-PSL University, Gustave Eiffel University, and Sorbonne Paris North University. The publications were obtained from Facebook, Instagram, and LinkedIn. Firstly, the groups of people to whom the use of inclusive French referred...
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π-Stacking attraction vs. electrostatic repulsion: competing supramolecular interactions in a tpphz-bridged Ru(ii)/Au(iii) complex
PublicationThe synthesis and characterization of a mixed metal ruthenium(II)/gold(III) complex bridged by tetrapyridophenazine (tpphz) are described. It is isostructural and isoelectronic to the well-known photocatalysts with palladium(II) or platinum(II). Concentration dependent 1H-NMR spectroscopy and XRD studies show that the electrostatic repulsion between the gold(III) moieties exceeds the attractive π-stacking interaction. Theoretical...
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Reliability model of the crankshaft-piston assembly
PublicationThe laws that govern the durability of crankshaft-piston assembly friction nodes can be proved or at least derived or justified in an intuitive way. Operation of all the friction nodes is disturbed by external factors occurring with randomly changing intensity and also appearing at random. As the crankshaft-piston assembly friction nodes have a series structure and effects of those disturbances accumulate, their fitness for use...
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Collaborative Delivery by Energy-Sharing Low-Power Mobile Robots
PublicationWe study two variants of delivery problems for mobile robots sharing energy. Each mobile robot can store at any given moment at most two units of energy, and whenever two robots are at the same location, they can transfer energy between each other, respecting the maximum capacity. The robots operate in a simple graph and initially each robot has two units of energy. A single edge traversal by an robot reduces its energy by one...
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Synthesis of bicoumarin thiophosphate derivatives as steroid sulfatase inhibitors
PublicationBased on the frameworks of 7-hydroxy-2,3-dihydro-1H-cyclopenta[c]chromen-4-one, 3-hydroxy- 7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one and 3-hydroxy-8,9,10,11-tetrahydro-7H-cyclohepta[c] chromen-6-one, a series of bicoumarin thiophosphate analogs have been synthesized and biologically evaluated. Additionally, their binding modes have been modeled using docking techniques. The inhibitory properties of the synthesized compounds...
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Estimation of structural stiffness with the use of Particle Swarm Optimization
PublicationThe paper presents the theoretical background and four applications examples of the new method for the estimation of support stiffness coefficients of complex structures modelled discretely (e.g. with the use of the Finite Element Model (FEM) method based on the modified Particle Swarm Optimization (PSO) algorithm. In real-life cases, exact values of the supports’ stiffness coefficients may change for various reasons...
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Improved RSS-Based DoA Estimation Accuracy in Low-Profile ESPAR Antenna Using SVM Approach
PublicationIn this paper, we have shown how the overall performance of direction-of-arrival (DoA) estimation using lowprofile electronically steerable parasitic array radiator (ESPAR) antenna, which has been proposed for Internet of Things (IoT) applications, can significantly be improved when support vector machine (SVM) approach is applied. Because the SVM-based DoA estimation method used herein relies solely on received signal strength...
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A framework for detection of selfishness in multihop mobile ad hoc networks
PublicationThe paper discusses the need for a fully-distributed selfishness detection mechanism dedicated for multihop wireless ad hoc networks which nodes may exhibit selfish forwarding behaviour. The main contribution of this paper is an introduction to a novel approach for detecting and coping with the selfish nodes. Paper describes a new framework based on Dempster-Shafer Theory called Dempster-Shafer Theory-based Selfishness Detection...
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Combined operation of 900MW power plant with the ORC through the bleed steam extraction point and CO2 recovery system
PublicationThe work presented here is aimed at utylisation of waste heat in the reference supercritical power plant in the manner to produce electricity in ORC installation. The waste heat is available in the form of a stream of hot water at 90 C, recovered from the exhaust gases in the amount of 200MW. Such low enthalpy heat source is rather insufficient to produce a good quality vapour to feed the ORC turbine. Therefore an original approach...
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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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A GPU Solver for Sparse Generalized Eigenvalue Problems with Symmetric Complex-Valued Matrices Obtained Using Higher-Order FEM
PublicationThe paper discusses a fast implementation of the stabilized locally optimal block preconditioned conjugate gradient (sLOBPCG) method, using a hierarchical multilevel preconditioner to solve nonHermitian sparse generalized eigenvalue problems with large symmetric complex-valued matrices obtained using the higher-order finite-element method (FEM), applied to the analysis of a microwave resonator. The resonant frequencies of the low-order...
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Structure of the interlayer between Au thin film and Si-substrate: Molecular Dynamics simulations
PublicationInteraction between 2, 3, 5 and 7 atomic layers of gold and a (111) silicon surface was investigated with the molecular dynamics simulation method. The simulation of the diffusion interaction between gold and silicon in the temperature range 425-925 K has been carried out. The peculiarities of the concentration changes of the interacting components and the atomic density at the boundary...
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A study on transverse shear correction for laminated sandwich panels
PublicationThe paper presents a study on an application of the First Order Shear Deformation Theory in a linear static analysis of elastic sandwich panels. A special attention has been given to the issue of the transverse shear correction. Two benchmark examples of sandwich plate problems with known reference solutions have been selected for a comparative analysis performed with own Finite Element codes. Interesting results allowed for drawing...
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A Review of Antennas for Indoor Positioning Systems
PublicationThis paper provides a review of antennas applied for indoor positioning or localization systems. The desired requirements of thoseantennas when integrated in anchor nodes (reference nodes) are discussed, according to different localization techniques and theirperformance. The described antennas will be subdivided into the following sections according to the nature of measurements:received signal strength (RSS), time of flight (ToF),...
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An additional ultrasonographic sign of Hashimoto’s lymphocytic thyroiditis in children
PublicationWe present an additional sonographic sign of Hashimoto’s thyroiditis (HLT), increasing the specifi city of this method in pediatric populations. Methods: A total of 98 children (mean age 12.7 years, range 7–17 years) were selected from the registry of the endocrinology outpatient department. All subjects met the diagnostic criteria for HLT. All children underwent a prospective thyroid ultrasound examination with special attention...
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On Symmetry of Uniform and Preferential Attachment Graphs
PublicationMotivated by the problem of graph structure compression under realistic source models, we study the symmetry behavior of preferential and uniform attachment graphs. These are two dynamic models of network growth in which new nodes attach to a constant number m of existing ones according to some attachment scheme. We prove symmetry results for m=1 and 2 , and we conjecture that for m≥3 , both models yield asymmetry with high...
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RSS-based DoA Estimation Using ESPAR Antennas and Interpolated Radiation Patterns
PublicationIn this letter, it is shown how an algorithm, which employs received signal strength (RSS) values in order to estimate direction-of-arrival (DoA) of impinging signals in wireless sensor network (WSN) nodes equipped with electronically steerable parasitic array radiator (ESPAR) antennas, can easily be improved by applying an interpolation algorithm to radiation patterns recorded in the calibration phase of the DoA estimation process....
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Modal Analysis of Planar Elliptical Resonator Deposited on Unshielded Dielectric Slab
PublicationModal analysis of isolated open planar elliptical patch placed on dielectric slab is presented in the paper. It applies concept of Illuminating Modes which is formulated for the case of two-side opened structure. The current on patch is expanded in basis functions in form of Mathieu radial and angular functions. The spectrum of excited modes for exemplary planar resonators is presented and discussed using the concept of power of...
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Influence of plasmon resonance on the luminescence of titanium dioxide thin films doped with rare earth ions
PublicationIn this work the study of the optical properties of europium doped titanium dioxide thin films (TiO2:Eu) enhanced by gold plasmonic nanostructures are presented. Plasmonic platforms were manufactured by thermal annealing of thin film of Au, deposited on a Corning glass substrate. As a result of thermal treatment, gold spherical nanostructures with average dimensions of 50 nm were obtained. Luminescent TiO2:Eu film was deposited...
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Preparation and characterization of monometallic (Au) and bimetallic (Ag/Au) modified-titania photocatalysts activated by visible light
PublicationThe Au-TiO2 and Ag/Au-TiO2 nanoparticles have been prepared using a water-in-oil microemulsion system of water/AOT/cyclohexane and water/Triton X-100/cyclohexane. The obtained photocatalysts were subsequently characterized by a BET method, DRS spectroscopy, X-ray photoelectron emission spectroscopy (XPS), scanning transmission electron microscopy (STEM) and X-ray powder diffraction analysis (XRD). For gold-doped titanium (IV) oxide...
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Trust Management Method for Wireless Sensor Networks
PublicationA Wireless Sensor Network (WSN) is a network of spatially distributed autonomous sensors to monitor physical or environmental conditions, such as temperature, sound, pressure, etc. and to cooperatively pass their data to the main location. The first wireless network that bore any real resemblance to a modern WSN is the Sound Surveillance System (SOSUS), developed by the United States Military in the 1950s to detect and track Soviet...
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Price convergence in the EU-an aggregate and disaggregate approach
PublicationThis article examines the price dispersion in the European Union (EU) over 15 years (1990-2005). An extensive overview of the literature offers inconclusive results with the half-lives of price shocks from 2.8 to 282 months. Until now, most of the empirical research has been either micro or macro based. In contrast, we conducted a complex analysis utilizing both aggregate and disaggregate price data. The macro approach is based...
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New concept of drilling auger for displacement pile installation
PublicationIn 2020, a new version of the screw displacement auger for pile installation in soil was developed and patented in Poland. It was named DPDT (Displacement Pile Drilling Tool). The general aim of its development was to reduce the soil resistances to the auger during screwing into the ground while maintaning a good load-bearing capacity for the screw displacement piles. The “DPDT-Auger” prototype was tested as a scaled-down model...
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Effect of sisal fiber filler on thermal properties of bio-based polyurethane composites
PublicationThis work is mainly focused on study of thermal and thermomechanical properties of obtained bio-based polyurethane (coded as bio-PU) composites via using different types of bio-components (bio-glycol, modified soybean oil and sisal fiber) in the procedure. The chemical structure, morphology and mechanical properties were also investigated and described in this manuscript in order to know more perfect characterization of produced...
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Selected Problems of Transport in Port Towns – Tri-City as an Example
PublicationPort towns are strategic places from the point of view of transport systems. They form integration junctions for various transport branches , apart from the traditional - road and railway ones , also for water( sea) transport which is active there. Moreover, air transport comes also into consideration , whose efficient functioning must be connected with good accessibility, that concerns sea transport as well. Efficient and...
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Modelling of heat transfer in supercritical pressure recuperators
PublicationIn the paper presented is analysis of convective flow heat transfer at supercritical pressure in channels of heat exchanger working in the thermodynamic cycle. The modelling is based on the division of the flow into three regions, namely the heavy fluid, a two phase flow consisting of the heavy and light fluids and finally the light fluid flow. Modelling is concentrated on the region of simultaneous flow of two fluids divided into...