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Wyniki wyszukiwania dla: melting point calculation
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The performance of ETFs on developed and emerging markets with consideration of regional diversity
PublikacjaThis study evaluates the performance of Exchange-Traded Funds (ETFs) by using various tracking error calculation approaches. The aim of the paper is, on the one hand, an evaluation of the performance of ETFs relative to their benchmarking indexes and, on the other, an endeavour to specify any relationship between this performance and both geographical location and the degree of market development. The research was conducted on...
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Implementation of high-precision computation capabilities into the open-source dynamic simulation framework YADE
PublikacjaThis paper deals with the implementation of arbitrary precision calculations into the open-source discrete element framework YADE published under the GPL-2+ free software license. This new capability paves the way for the simulation framework to be used in many new fields such as quantum mechanics. The implementation details and associated gains in the accuracy of the results are discussed. Besides the "standard" double (64 bits)...
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Detection of petroleum products using optical coherence tomography
PublikacjaIn this work, we present a novel method developed for the analysis of the properties of thin layers for detecting petroleum products on a water surface using a commercially available optical coherence tomography (OCT) system. The spectral density analysis of the signal from a spectroscopic OCT (S-OCT) enables us to perform the precision calculation of the thin layer thickness and other properties like homogeneity, and dispersion,...
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OPTIMIZATION OF THE LAST STAGE OF GAS-STEAM TURBINE USING A HYBRID METHOD
PublikacjaThis paper relates to the CFD calculation of a new turbine type which is in the phase of theoretical analysis, because the working fluid is a mixture of steam and gas generated in wet combustion chamber. At first, this article concentrates on a possibility of streamlining the flow efficiency of a last stage of axial turbine working on gas-steam mixture using a hybrid of the particle swarm optimization algorithm with the Nelder-Mead...
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The Methodology for Determining the Theoretical Based on the Characteristics of Effective Absorbency Versus Pressure Drop in the Motor
PublikacjaThis article describes a method for determining the theoretical and actual working volume of a hydraulic motor. It has been shown that the actual working volume of the motor is the sum of the theoretical working volume and the additional volume that depends on the pressure drop in the working chambers of the motor. It was also shown that the volumetric losses in the hydraulic motor are not only a function of the pressure drop in...
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CONCRETE MIX DESIGN USING ABRAMS AND BOLOMEY METHODS
PublikacjaOne way to reduce the consumption of cement is to optimize its use. Many known methods of concrete design, based on the Abrams law and the Bolomey method. Therefore, the authors chose those methods for analysis. The concrete composition with the assumed strength class, calculated by any method differs significantly. This applies especially to the cement content, as its content in the composition of concrete varies from 20 to 50%....
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Very accurate time propagation of coupled Schrödinger equations for femto- and attosecond physics and chemistry, with C++ source code
PublikacjaIn this article, I present a very fast and high-precision (up to 33 decimal places) C++ implementation of the semi-global time propagation algorithm for a system of coupled Schrödinger equations with a time-dependent Hamiltonian. It can be used to describe time-dependent processes in molecular systems after excitation by femto- and attosecond laser pulses. It also works with an arbitrary user supplied Hamiltonian and can be used...
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Comparison of the Efficiency of Deammonification under Different DO Concentrations in a Laboratory-Scale Sequencing Batch Reactor
PublikacjaThe efficiency of deammonification depends on the cooperation of ammonium oxidizing bacteria and archaea (AOB/AOA), anaerobic ammonium oxidizing bacteria (AnAOB) and the effective suppression of nitrite oxidizing bacteria (NOB) that compete with AnAOB for nitrite (NO2 -N). One of the effective NOB suppression strategies is intermittent aeration. However, it is important to have a good understanding of the optimum dissolved oxygen...
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Closed Form Constraint Equations Used to Express Frictionless Slip of Multibody Systems Attached to Finite Elements—Application to a Contact between a Double Pendulum and a Beam
PublikacjaThis paper focuses on the numerical modeling of the dynamics of mechanical systems. Robots that can inspect high-voltage lines inspired this research. Their control systems must anticipate potential grab positions appropriately. We intend to formulate equations dedicated to the numerical description of the robot/cable contact. The investigated problem is not straightforward, since parts of the modeled systems are numerically inhomogeneous....
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Bifurcation of equilibrium forms of an elastic rod on a two-parameter Winkler foundation
PublikacjaWe consider two-parameter bifurcation of equilibrium states of an elastic rod on a deformable foundation. Our main theorem shows that bifurcation occurs if and only if the linearization of our problem has nontrivial solutions. In fact our proof, based on the concept of the Brouwer degree, gives more, namely that from each bifurcation point there branches off a continuum of solutions.
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Badania i analizy kolejowych konstrukcji odciążających typu mostowego
PublikacjaW pracy przedstawiono i omówiono wybrane modele obliczeniowe, wyniki analiz teoretycznych oraz badań trzech typów kolejowych konstrukcji odciążających typu mostowego. Zaprezentowano modele obliczeniowe oraz metodykę badań in situ tego typu konbstrukcji. Przedstawiono wnioski dotyczące zaawansowanych metod obliczeniowych rozszerzonych badań in situ w celu diagnozowania rzeczywistej pracy obiektów mostowych.
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Application, design and operation of constructed wetland systems: case studies of systems in the Gdańsk region, Poland
PublikacjaDifferences in operation result from physical, chemical and biological conditions, which directly influence transformations in the whole aquatic-matrix-plants environment. Depending on the quantity of inflowing organic matter load and the rate of biochemical processes, the contaminations could be removed or/and retuned in the system. From this point of view the facility should be designed and operated in such way that the highest...
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Purely quantum superadditivity of classical capacities of quantum multiple access channels
PublikacjaWe are studying classical capacities of quantum memoryless multiaccess channels in geometric terms and we are revealing a break of additivity of the Holevo-like capacity. This effect is a purely quantum mechanical one, since, as we point out, the capacity regions of all classical memoryless multiaccess channels are additive. It is the first such effect revealed in the field of classical information transmission via quantum channels.
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Visualization of Spatial Issues in Adobe Acrobat 3D PDF
PublikacjaThe ability to capture and embed model information in a 3D PDF file and subsequently share it for free is highly needed in the education of descriptive geometry. The described technology and in particular inserting 3D models into the other files can improve the existing teaching materials. The strongest point of 3D PDF technology is that the model can be visualized and manipulated in multiple ways by viewers which enhance the...
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Application of Reverse Engineering Technology in Part Design for Shipbuilding Industry
PublikacjaIn the shipbuilding industry, it is difficult to create CAD models of existing or prototype parts, especially with many freeform surfaces. The paper presents the creation of the CAD 3D model of a shipbuilding component with the application of the reverse engineering technology. Based on the data obtained from the digitization process, the component is reconstructed in point cloud processing programs and the CAD model is created....
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Time-domine Dipole Fields in acoustic and Elektromagnetics
PublikacjaThe ultrawideband (UWB) radio technique presents a challenge not just for technology. The UWB carrier-free pulses act at a close distance, their electromagnetic fields being very different from classic monochromatic plane wave. The author proposes to adapt a time-domian approach to analysis of broadband spherical fields, both acoustic and electromagnetic, in fundamental cases of quasi-point physical sources.
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Experience Visualizaton
PublikacjaSet of Experience Knowledge Structure (SOEKS) has proved its capability of storing substantial part of experience at a particular decision point. The management of SOEKS record is also proposed in many papers for example referring to concepts of Decisional DNA knowledge representation, that is a collection of a number of SOEKS. The aim of this paper is to focus on visualization and practical aspects of presenting gathered knowledge...
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Towards Cognitive and Perceptive Video Systems
PublikacjaIn this chapter we cover research and development issues related to smart cameras. We discuss challenges, new technologies and algorithms, applications and the evaluation of today’s technologies. We will cover problems related to software, hardware, communication, embedded and distributed systems, multi-modal sensors, privacy and security. We also discuss future trends and market expectations from the customer’s point of view.
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Functional delay fractional equations
PublikacjaIn this paper, we discuss functional delay fractional equations. A Banach fixed point theorem is applied to obtain the existence (uniqueness) theorem. We also discuss such problems when a delay argument has a form α(t) = αt, 0 < α < 1, by Rusing the method of successive approximations. Some existence results are also formulated in this case. An example illustrates the main result.
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Design of OFDM-based radio communication systems for coast-to-sea and coast-to-air propagation environments
PublikacjaIn the paper the study of radio communication system design process for systems based on OFDM transmission is considered. The signal propagation model for 1.4 GHz frequency band is discussed, and the study of signal propagation characteristics, important from the point of view of OFDM system design, is presented. The methodology of OFDM interface design is proposed and some characteristics of the OFDM-based radio communication...
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Positivity and job burnout in emergency personnel: examining linear and curvilinear relationship
PublikacjaThe aim of this study was to examine whether the relationship between the ratio of job-related positive to negative emotions (positivity ratio) and job burnout is best described as linear or curvilinear. Participants were 89 police officers (12% women) and 86 firefighters. The positivity ratio was evaluated using the Job-related Affective Wellbeing Scale (Van Katwyk, Fox, Spector, & Kelloway, 2000). Exhaustion and disengagement,...
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Ekspatrianta versus lokalny menedżer, czyli kto powinien kierować filią zagraniczną? = Expatriate versus host country manager - who should run a foreign subsidiary?
PublikacjaThere is ample literature on expatriate management that presents a parent company's point of view on this issue. A consideration of subsidiary management from the local perspective is missing. Relationships with foreigners (including expatriates) are cross-cultural interactions and their effectiveness is affected by cultural factors. Therefore, in this article there are questions that need to be answered:1. What role does an expatriate...
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Cross-layer integration of network mechanisms for increasing efficiency of multimedia session support in IEEE 802.11s environment
PublikacjaWith an IEEE 802.11 wireless networks operating in Point-to-Multipoint mode being the most popular WLAN access technology employed today, it can be expected that a Wireless Mesh Network (WMN) based on the technology can provide significant advantages for such network systems. The IEEE 802.11s standard amendment provides the comprehensive set of mechanisms required to implement and deploy a WMN utilizing this widely popular technology....
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Comparative study of a bottoming SRC and ORC for Joule–Brayton cycle cooling modular HTR exergy losses, fluid-flow machinery main dimensions, and partial loads
PublikacjaEnergy conversion efficiency increase in power plants with high-temperature gas-cooled reactors via implementation of the bottoming cycle was investigated under nominal and minimal thermal load of a high-temperature reactor (HTR). Heat transfer surface area and turbine outlet volumetric flow rate in bottoming cycles was also investigated. Water and two low-boiling point working fluids (ammonia and ethanol) were analyzed. Analyzed...
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Selected Problems of Transport in Port Towns – Tri-City as an Example
PublikacjaPort 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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Proton affinities of simple organic compounds
PublikacjaThe Restricted Hatree-Fock method with 6-311G** split-valence molecular orbitals basis sets has been applied to geometrical optimizations and calculations of total electronic, zero point vibrational energies and proton affinities at 298 K for small neutral and protonated alkanes, alcohols, acetic acid, methyl and ethyl acetate, acetone, and acetaldehyde. Calculated values of proton affinities are compared with experimental data.
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Aspects of multistation quantum information broadcasting
PublikacjaWe study quantum information transmission over multiparty quantum channel. In particular, we show an equivalence of different capacity notions and provide a multiletter characterization of a capacity region for a general quantum channel with k senders and m receivers. We point out natural generalizations to the case of two-way classical communication capacity. (C) 2010 Elsevier B.V. All rights reserved.
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PROBABILISTIC ANALYSIS OF A SPACE TRUSS BY MEANS OF A MULTIDIMENSIONAL VARIABLE DESCRIPTION
PublikacjaThe objective of this paper is to present a variant of the point estimate method (PEM) to determine mean values and standard deviations of limit loads of engineering structures. This approach is illustrated by limit state analysis of a space truss, considering geometric and material imperfections. The calculations were performed for different random models, so the influence of random parameters on the limit load of the truss can...
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Microcrystalline diamond film evaluation by spectroscopic optical coherence tomography
PublikacjaThis study has focused on the microcrystalline diamond film (MCD) thickness evaluation. For this purpose, optical coherence tomography (OCT) enhanced by spectroscopic analysis has been used as a method of choice. The average thickness of the tested layer was about 1.5 µm, which is below the standard 2-point OCT resolution. In this case, the usefulness of the spectroscopic analysis was confirmed for the evaluation of the thickness...
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Low-Cost Method for Internal Surface Roughness Reduction of Additively Manufactured All-Metal Waveguide Components
PublikacjaIn this study, a novel low-cost polishing method for internal surface roughness reduction of additively manufactured components, developed for waveguide (WG) circuits operating in the millimeter frequency range is proposed. WG components fabricated using powder bed fusion (PBF) generally feature roughness of ten to fifty microns, which influences the increase of roughness-related conductor power losses having a major effect on...
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The New LM-PCR/Shifter Method for the Genotyping of Microorganisms Based on the Use of a Class IIS Restriction Enzyme and Ligation Mediated PCR
PublikacjaThis study details and examines a novel Ligation-Mediated - Polymerase Chain Reaction (LM-PCR) method. Named the LM-PCR/Shifter, it relies on the use of a Class IIS restriction enzyme giving restriction fragments with different 4 base, 5' overhangs, this being the Shifter, and the ligation of appropriate oligonucleotide adapters. A sequence of 4-base, 5' overhangs of the adapter and a 4-base sequence of the 3' end of the primer(s)...
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Occurrences, sources, and transport of organochlorine pesticides in the aquatic environment of Antarctica
PublikacjaWe review information on the concentration levels of organochlorine pesticides in the abiotic aquatic environment (in seawater, sea ice, surface freshwater, snow, firn, and glacial ice) and the organisms inhabiting those, in Antarctica. Particular attention is given to the environmental fate of these pollutants, which modifies their impact on the organisms living in the Antarctic. OCPs have been delivered to the Antarctic environment...
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Anodic titania nanotubes decorated with gold nanoparticles produced by laser-induced dewetting of thin metallic films
PublikacjaHerein, we combine titania layers with gold species in a laser-supported process and report a substantial change of properties of the resulting heterostructures depending on the major processing parameters. Electrodes were fabricated via an anodisation process complemented with calcination to ensure a crystalline phase, and followed by magnetron sputtering of metallic films. The obtained TiO2 nanotubes with deposited thin (5, 10...
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Elucidating photoluminescent properties of Eu‐doped Ca–Al–Si–O(–N) glasses and the local structures of Eu ions
PublikacjaEuropium (Eu) ion–doped luminescent materials have attracted considerable attention for their numerous optical applications. Eu-doped Ca–Al–Si–O(–N) glasses were synthesized from a mixture of oxynitride glasses and Eu2O3 powder using a standard melt-quenching technique in a radiofrequency furnace. The source Eu trivalent ions primarily changed to Eu2+ during melting, and the ratio of Eu2+ ions increased with an increase in Eu content...
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Effect of bending-torsion on fracture and fatigue life for 18Ni300 steel specimens produced by SLM
PublikacjaIn this study, different fracture surfaces caused by fatigue failure were generated from 18Ni300 steel produced by selective laser melting (SLM). Hollow round bars with a transverse hole were tested under bending-torsion to investigate the crack initiation mechanisms and fatigue life. Next, the post-failure fracture surfaces were examined by optical profilometer and scanning electron microscope. The focus is placed on the relationship...
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Ferromagnetism in Pr-rich binary Pr7Ru3 intermetallic compound
PublikacjaWe present the synthesis and experimental characterization of the binary intermetallic compound Pr7Ru3. The polycrystalline sample was prepared by arc melting pure Pr and Ru, followed by homogenization at 500 °C and 600 °C for 48 and 89 h, respectively. Powder x-ray diffraction confirms that Pr7Ru3 crystallizes in an orthorhombic crystal structure (Pnma, space group no. 62) with the lattice parameters: a = 7.3606(7) Å, b = 23.120(1)...
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Wpływ właściwości czynników chłodniczych na straty egzergii w pompie ciepła (Influence of Refrigerants Properties for Exergy Losses in Heat Pump)
PublikacjaArtykuł poświęcony jest wpływowi występujących w pompie ciepła strat egzergii na jej efektywność energetyczną, a co za tym idzie koszty funkcjonowania instalacji. Autorzy prezentują tu metodologię obliczeniową, która może być zastosowana w procesach projektowania układów cieplno-przepływowych. Obliczenia zostały wykonane na podstawie typowego układu powietrznej pompy ciepła pracującej w klimacie środkowo-europejskim. Ponadto w...
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The issue of uncertainty of visual measurement techniques for long distance measurements based on the example of applying electric traction elements in diagnostics and monitoring
PublikacjaRail transport is the most economical and energy-effective in the field of land transport, in particular electrified. In order to ensure efficient and reliable operation of electrified rail transport, the issues of monitoring and diagnostics of the traction infrastructure and vehicles are extremely important. The most critical point in the transmission of electric energy to the vehicle is the sliding contact of the current collector...
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Personal Branding and Brand Loyalty, Social Network Users Brand Identification: Polish-French Model
PublikacjaSocial network brand sites are increasingly attracting the attention of scientists and managers intrigued by their potential application for brand value creation. The aim of this research, based on a multinational sample, is to fill the gap in understanding how users choose among social networking sites as an act of brand identification. The authors of the paper point to the fact that creating a personal brand is becoming more...
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Cyfrowa wewnątrzsamolotowa magistrala komunikacyjna ARINC 429
PublikacjaW artykule przedstawiono standard cyfrowej magistrali komunikacyjnej ARINC 429 przeznaczonej do współpracy urządzeń na pokładzie samolotów. Skupiono się na warstwie fizycznej i protokolarnej tego standardu.
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Simplified method of applying loads to flat slab floor structural model
PublikacjaThe article analyses the impact of the live load position on the surface of a reinforced concrete flat slab floor of 32.0 m × 28.8 m. Four variants of a live load position are investigated: located on the entire concrete slab, set in a chessboard pattern, applied by bands and imposed separately in each of the slab panels. Conclusions are drawn upon differences in bending moments, the time of calculation and the size of output files....
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Numerical assessment of ultimate strength of severe corroded stiffened plates
PublikacjaThe objective of this work is to investigate numerically (using the non-linear FEM and the approach stipulated by the Common Structural Rules) the severe nonuniform corrosion degradation effect on the ultimate strength of stiffened plates and compare the results to the already published experimental works. Different factors governing structural behavior of corroded stiffened plates are investigated, such as corrosion degradation level,...
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Improved magnitude estimation of complex numbers using alpha max and beta min algorithm
PublikacjaThe paper presents an improved algorithm for calculating the magnitude of complex numbers. This problem, which is a special case of square rooting, occurs for example, in FFT processors and complex FIR filters. The proposed method of magnitude calculation makes use of the modified alpha max and beta min algorithm. The improved version of the algorithm allows to control the maximum magnitude approximation error by using an adequate...
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Dynamics of cutting power during sawing with circular saw blades as an effect of wood properties changes in the cross section
PublikacjaIn the paper the effect of the method calculation upon the cutting power is presented. In computations were used models in which fracture toughness was incorporated. The comparison concerned models as follows: FM-CM – classic model in which the sum of all uncut chip thicknesses of the simultaneously teeth engaged represented the mean uncut chip thickness, FM-FDM – full dynamical model in which besides variable uncut chip thickness...
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Electron interactions with Bis(pentamethylcyclopentadienyl) titanium(IV) dichloride and difluoride
PublikacjaWe present a combined experimental and theoretical study of the interaction of electrons with Bis(pentamethylcyclopentadienyl)titanium(IV) dichloride (Cp∗2TiCl2) and difluoride (Cp∗2TiF2). We report the experimental measurements of partial cross sections for the dissociative electron attachment (DEA) and the electron ionization (EI) mass spectra of isolated molecules. Estimates of the absolute cross sections are done on the basis...
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Flow through a prosthetic mechanical aortic valve: Numerical model and experimental study
PublikacjaThis research presents a numerical model dedicated for virtual patient diagnostics in the field of synthetic valve implantation. The model operates based on computational fluid dynamics solver with implemented rigid body motion solver. Characteristic indicators related to the prosthetic valve were determined to assess the correctness of cardiac system operation after implantation. A novel approach for dynamic time discretization...
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The influence of water and mineral oil on volumetric losses in the displacement pump for offshore and marine applications
PublikacjaIn this paper volumetric losses in a positive displacement pump supplied with water and mineral oil are described and compared. The experimental tests were conducted using a prototype of a satellite pump (with a non-circular tooth working mechanism). In this paper the sources of volumetric losses in this pump are characterised. On this basis, a mathematical model of these losses has been presented. The results of the calculation...
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Problems of analytical determination of journal bearing bush fatigue strength estimates
PublikacjaProblems connected with determination of stress distribution in sliding layer of thinwalled bearing bushes, investigated in bearing fatigue test rigs, have been presented. Using an example of plain bearings tested in the fatigue machine SMOK (built at the Gdask University of Technology) problems with obtaining a convergence of iterative procedure for determining the fatigue strength estimators of bearing alloy surface layer are...
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Multibeam sonar data processing for seafloor characterisation
PublikacjaThe approach to seafloor characterisation was investigated. It relies on calculation of several descriptors (parameters) related to seabed type using three types of multibeam sonar data obtained during seafloor sensing: 1) the grey-level sonar images of seabed, 2) the 3D model of the seabed surface which consist of (x, y, z) points, 3) the set of time domain echo envelopes corresponding to several beams. The proposed method has...
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Combined method of multibeam sonar signal processing and image analysis for seafloor classification
PublikacjaThe combined approach to seafloor characterisation was investigated. It relies on calculation of several descriptors (parameters) related to seabed type using three types of multibeam sonar data obtained during seafloor sensing: 1) the grey-level sonar images (echograms) of seabed, 2) the 3D model of the seabed surface which consists of bathymetric data, 3) the set of time domain bottom echo envelopes received in the consecutive...