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Tracking of the broadband source of the underwater noise in the very shallow water conditions
PublicationThe paper contains the result s, both theoretical and experimental , connected with the tracking of the underwater noise source as small ships, pontoon , diver and so on. The pro blem of security in the shallow water area is the challenge for underwater acousticians. In this paper there is take n into account the detection of the sources that move on the surface of the sea or underwater in shallow...
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A Series-Inclined-Slot-Fed Circularly Polarized Antenna for 5G 28-GHz Applications
PublicationThis letter presents the design of a single-point-fed, geometrically simple circularly polarized (CP) antenna for 28 GHz Ka-band applications. The proposed antenna is based on a straight microstrip line printed on one side and coupled with the nearly square patches through a 45-degree inclined V-shape slot aperture on the other side. In order to generate circular polarization, the fundamental radiating mode is degenerated at a...
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Analysis of circular polarization antenna design trade‐offs using low‐cost EM‐driven multiobjective optimization
PublicationCircular polarization (CP) antennas are vital components of modern communication systems. Their design involves handling several requirements such as low reflection and axial ratio (AR) within the frequency range of interest. Small size is an important criterion for antenna mobility which is normally achieved as a by‐product of performance‐oriented modifications of the structure topology. In this work, multiobjective optimization...
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Influence of soil anisotropic stiffness on the deformation induced by an open pit excavation.
PublicationIn this paper, the problem of deformation induced by an open pit excavation in anisotropic stiff soils is analysed by FE modelling. The presented research is focused on the influence of material model with anisotropic stiffness on the accuracy of deformation predictions as compared with the field measurements. A new hyperelastic-plastic model is applied to simulate anisotropic mechanical behaviour of stiff soils. It is capable...
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On dynamics of origami-inspired rod
PublicationWe discuss the dynamics of a relatively simple origami-inspired structure considering discrete and continuum models. The latter was derived as a certain limit of the discrete model. Here we analyze small in-plane deformations and related equations of infinitesimal motions. For both models, dispersion relations were derived and compared. The comparison of the dispersion relations showed that the continuum model can capture the behavior...
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On refined constitutive equations in the six-field theory of elastic shells
PublicationWithin the resultant six-field shell theory, the second approximation to the complementary energy density of an isotropic elastic shell undergoing small strains is constructed. In this case, the resultant drilling couples are expressed explicitly by the stress resultants and stress couples as well as by amplitudes of the quadratic and cubic distributions of an intrinsic deviation vector. The refined 2D strain-stress and stress-strain...
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Wzrost zatrudnienia w pomorskich firmach – świadome planowanie czy przypadek
Publicationroblematyka poruszająca relację planowania w małych przedsiębiorstwach do wyników przez nie osiąganych doczekała się wielu badań, których wyniki są niejednoznaczne. Niejednoznaczność ta w dużym stopniu jest spowodowana wykorzystywaniem różnych miar tych zależności. Przeprowadzone na Pomorzu badania panelowe wskazały jednoznacznie na brak związków między planowaniem a wynikiem funkcjonowania przedsiębiorstwa mierzonego wzrostem...
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MODELOWANIE TURBINY WIATROWEJ Z DWOMA PRZECIWBIEŻNIE OBRACAJĄCYMI SIĘ WIRNIKAMI
PublicationW artykule przedstawiono sposoby modelowania dwuwirnikowej turbiny wiatrowej z wykorzystaniem technik Obliczeniowej Mechaniki Płynów. Omówiono uproszczone metody modelowania Actuator Disc i Actuator Line Method oraz aspekty związane z dokładnym odwzorowaniem turbiny na siatce obliczeniowej. Zaprezentowano przykładowe wyniki obliczeń turbiny dwuwirnikowej złożonej z wirników NREL o mocy nominalnej 5 MW każdy. Do wykonania badań...
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Chip suction system in circular sawing machine: empirical research and computational fluid dynamics numerical simulations
PublicationThe experimental analysis of the wood chip removing system during its redesigning in the existing sliding table circular saw and computational fluid dynamic (CFD) numerical simulations of the air flow process is presented in the paper. The attention was focused on the extraction hood and the bottom shelter of the actual existing system. The main aim was to perform experimental research on the pressure distribution inside the...
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Laser-assisted approach for improved performance of Au-Ti based glucose sensing electrodes
PublicationThis paper focuses on the synthesis route and electrochemical properties of electrocatalytic material based on gold nanoparticles (NPs) embedded in a structured titanium template obtained via optimized anodization, chemical etching and laser processing. SEM inspection reveals the presence of Au NPs (60–90 nm in diameter) sited in the titanium foil cavities. Performed electrochemical measurements enable nomination of the set of working...
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Laser-assisted modification of titanium dioxide nanotubes in a tilted mode as surface modification and patterning strategy
PublicationElectrochemical anodization is regarded as a facile and easily scalable fabrication method of titania nanotubes (TiO2NTs). However, due to the extended duration of calcination and further modifications, much faster alternatives are highly required. As a response to growing interest in laser modification of nanotube arrays, a comprehensive investigation of pulsed-laser irradiation and its effect onto TiO2NT properties has been carried out....
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ASSESSING THE POTENTIAL REPLACEMENT OF MINERAL OIL WITH ENVIRONMENTALLY ACCEPTABLE LUBRICANTS IN A STERN TUBE BEARING: AN EXPERIMENTAL ANALYSIS OF BEARING PERFORMANCE
PublicationT his study compares the performance of a plain bearing, with a similar structure to a tail shaft stern bearing, lubricated with either mineral oil or an environmentally acceptable lubricant (EAL). The main characteristic of the bearing is its length/diameter ratio of <1. Measurements are carried out with the bearing operating under loads from 0.5 to 1 MPa and seven speeds ranging from 1 to 11 rev/s. The bearing lubricated...
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Size effect at aggregate level in microCT scans and DEM simulation – Splitting tensile test of concrete
PublicationThe paper describes an experimental and numerical study of size effect on concrete cylindrical specimens in splitting tensile test. Own experimental campaign was performed on specimens with 5 various diameters from D = 74, 105, 150, 192 and 250 mm with hardboard loading strips (distributed load according to standard methods) scaled proportionally to the specimen diameter. The crack opening-control system was applied to obtain the...
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Biomass Production and Removal of Nitrogen and Phosphorus from Processed Municipal Wastewater by Salix schwerinii: A Field Trial
PublicationIn many Baltic regions, short-rotation willow (Salix spp.) is used as a vegetation filter for wastewater treatment and recycling of valuable nutrients to upsurge bioeconomy development. In this context, a four-year field trial (2016–2019) was carried out near a wastewater treatment plant in eastern Finland (Outokumpu) to investigate the effect of the processed wastewater (WW) on biomass production as well as the nutrients uptake...
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Prediction of Pile Shaft Capacity in Tension Based on Some Direct CPT Methods—Vistula Marshland Test Site
PublicationThis paper presents different CPT methodologies for the prediction of the pile shaft resistance in tension on the example of three reference screw piles of the Jazowa test site in Poland. The shaft capacity was estimated based on the cone resistance, sleeve friction and CPT excess pore water pressure. Three piles with diameter 0.4 m and the length varied from 8 m to 14.6 m were subjected to static load tests in tension. Their...
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Experimental study and comparison with predictive methods for flow boiling heat transfer coefficient of HFE7000
PublicationThis article describes an experimental study of flow boiling of HFE7000 inside a smooth vertical channel. The investigation has been carried out in a circular stainless-steel tube with an inner diameter of 2.3 mm. The data have been collected for the applied heat fluxes q ranging from 61 to 205 kW/m2, the mass flux G ranging from 214 to 1006 kg/(m2 s), the saturation temperature Tsat ranging from 30 to 54 °C and the full range...
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Mechanical and fracture properties of concrete reinforced with recycled and industrial steel fibers using Digital Image Correlation technique and X-ray micro computed tomography
PublicationPaper presents investigation of fracture phenomenon in plain concrete and in concrete reinforced with both recycled steel fibers (RSF) and industrial steel fibers (ISF). The wedge splitting test (WST), which enables stable crack propagation for quasi-brittle materials, was carried out on 75 75 75 mm cube samples. Initially, fracture process zone development was investigated only on the surface of samples using Digital Image Correlation...
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Comparison of noise reduction methods in radiometric correlation measurements of two-phase liquid-gas flows
PublicationTwo-phase liquid-gas flows occur frequently in the mining, energy, chemical, and petrochemical industries. One of non-contact methods used to analyse these flows is the gamma ray absorption method. However, the signals received from radiation detectors contain a significant stochastic noise, which makes them difficult to analyse. The article describes four methods of noise reduction in cross-correlation measurements of water-air...
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Screw displacement pile shaft deformations measured by vibrating wire and fiber optic systems during a static load test
PublicationThis paper describes a full scale static load test performed on a 400 mm diameter screw displacement pile equipped with four different strain measuring systems. Three types of vibrating wire strain gauges (VWSG) were used: global - retrievable, local attached to steel pipe and local concrete embedded. The fourth system was distributed fiber optic sensors based on Rayleigh back scattering (DFOS) - three in the pile cross section....
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Solid Oxide Fuel Cells with Ni infiltrated perovskite anode
PublicationNiobium-doped strontium titanate was used as the anode for a solid oxide fuel cell. Electrolyte-supported cells were prepared with pure perovskite and composite perovskite–yttria–stabilized-zirconia (YSZ) anodes. Fuel cell tests demonstrated significant improvement in power density after infiltration with a small amount of Ni. The obtained values of power densities are comparable with conventional Ni/YSZ cermet anode. In addition,...
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An Analysis of Probe-Fed Rectangular Patch Antennas With Multilayer and Multipatch Configurations on Cylindrical Surfaces
PublicationA multi-patch configuration of probe-fed rectangular microstrip antennas mounted on a cylindrical body, with electrically small radius, with an arbitrary number of substrate and superstrate layers is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. A unified procedure for creating proper matrices for the investigated geometry of the structure is outlined here. Numerical results for...
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FATE OF LAS SURFACT ANTS IN WWTPs BASED ON MEASURED CONCENTRATIONS IN WASTEWATER AND SLUDGE
PublicationThe fate of the surfactant LAS in the two different types of Waste Water Treatment Plants has been reviewed: the small “Swarzewo” WWTP (45 000 PE), and large WWTP “Wschód” (760 000 PE). The elimination of LAS from the water stream in Swarzewo (98,7%), is better than that found in Gdańsk (97,6%). In the sludge treatment course, the reduction of LAS in Swarzewo is greater than that in Gdańsk due to the greater biodegradation of LAS...
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Sensorless Rotor Position Estimation of Doubly-Fed Induction Generator Based on Backstepping Technique
PublicationThis paper proposes a speed observer algorithm for the sensorless control of a doubly-fed induction generator based on classical adaptive backstepping technique. The sensorless control is shown using classic stator field oriented control which is used to active and reactive power control. Performance of the proposed algorithm of a speed observer is validated by simulation and experimental results obtained using a small-rating generator...
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Comparison of selected parametric methods for prediction of inland waterways ship hull resistance in towing tank test
PublicationIn the paper selected approximate methods for calculation of inland waterways ship resistance and their verification by towing tests, compared on the example of a small urban ferry, are presented. The test results are made for both the bare hull and the hull with appendages (skeg, azimuthal propeller). Significant differences between results of the theoretical methods and experimental ones, especially in the case of the model with...
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Control of a vapour microturbine set in cogeneration applications
PublicationSystems with microturbines are implemented for local generation of heat and electricity. This paper presents the analysis of control concepts for a vapour microturbine set with a generator with permanent magnets, intended to work in small heat and power plants. Control system variants differed by the selection of controlled signals and set parameters. Possible ways of control were discussed and compared with experimentally determined...
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Using Continuous Integration Techniques in Open Source Projects – An Exploratory Study
PublicationFor a growing number of software projects, continuous integration (CI) techniques are becoming an essential part of the process. However, the maturity of their adoption in open source projects varies. In this paper, we present an empirical study on GitHub repositories to explore the use of continuous integration techniques in open source projects. Following the Goal-Question-Metric (GQM) approach, 3 research questions and 7 metrics...
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The bile salt content of human bile impacts on simulated intestinal proteolysis of β-lactoglobulin
PublicationThe gastrointestinal hydrolysis of food proteins has been portrayed in scientific literature to predominantly depend on the activity and specificity of proteolytic enzymes. Human bile has not been considered to facilitate proteolysis in the small intestine, but rather to assist in intestinal lipolysis. However, human bile can potentially influence proteins that are largely resistant to gastric digestion, and which are mainly hydrolysed...
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Multisensor System for the Protection of Critical Infrastructure of Seaport
PublicationThere are many separated infrastructural objects within a harbor area that may be considered “critical”, such as gas and oil terminals or anchored naval vessels. Those objects require special protection, including security systems capable of monitoring both surface and underwater areas, because an intrusion into the protected area may be attempted using small surface vehicles (boats, kayaks, rafts, floating devices with weapons...
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The Proposal to “Snapshot” Raim Method for Gnss Vessel Receivers Working in Poor Space Segment Geometry
PublicationNowadays, we can observe an increase in research on the use of small unmanned autonomous vessel (SUAV) to patrol and guiding critical areas including harbours. The proposal to “snapshot” RAIM (Receiver Autonomous Integrity Monitoring) method for GNSS receivers mounted on SUAV operating in poor space segment geometry is presented in the paper. Existing “snapshot” RAIM methods and algorithms which are used in practical applications...
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On adaptive covariance and spectrum estimation of locally stationary multivariate processes
PublicationWhen estimating the correlation/spectral structure of a locally stationary process, one has to make two important decisions. First, one should choose the so-called estimation bandwidth, inversely proportional to the effective width of the local analysis window, in the way that complies with the degree of signal nonstationarity. Too small bandwidth may result in an excessive estimation bias, while too large bandwidth may cause excessive...
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Low-Cost Unattended Design of Miniaturized 4 × 4 Butler Matrices with Nonstandard Phase Differences
PublicationDesign of Butler matrices dedicated to Internet of Things and 5th generation (5G) mobile systems—where small size and high performance are of primary concern—is a challenging task that often exceeds capabilities of conventional techniques. Lack of appropriate, unified design approaches is a serious bottleneck for the development of Butler structures for contemporary applications. In this work, a low-cost bottom-up procedure for...
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Efficient Surrogate Modeling and Design Optimization of Compact Integrated On-Chip Inductors Based on Multi-Fidelity EM Simulation Models
PublicationHigh-performance and small-size on-chip inductors play a critical role in contemporary radio-frequency integrated circuits. This work presents a reliable surrogate modeling technique combining low-fidelity EM simulation models, response surface approximations based on kriging interpolation, and space mapping technology. The reported method is useful for the development of broadband and highly accurate data-driven models of integrated...
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Relatively high-Seebeck thermoelectric cells containing ionic liquids supplemented by cobalt redox couple
PublicationMeanwhile no general and reliable equation determining the Seebeck coefficient (S e ) and involving electro-chemical reaction effects was derived for solutions. We reported the database of 15,000 ionic liquids supplemented by three different redox couple systems: 0.01 mol/l Co 3+/2+ (bpy) 3 , 0.01 mol/l I 3-/3I- and 0.2 mol/l 3- /3I- , and the corresponding estimated Seebeck coefficients. We also reported methods for estimating...
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ZRÓŻNICOWANIE STRUKTURY KAPITAŁOWO-MAJĄTKOWEJ W ZALEŻNOŚCI OD WIELKOŚCI PRZEDSIĘBIORSTWA
PublicationW artykule przedstawiono różnice w kształtowaniu struktury kapitałowo-majątkowej pomiędzy małymi, średnimi i dużymi przedsiębiorstwami. W trakcie przeprowadzonych badań uwzględniono 97 471 sprawozdań finansowych przedsiębiorstw, prowadzących działalność gospodarczą w 12 różnych działach polskiej gospodarki narodowej. Do potwierdzenia zróżnicowania struktury kapitałowo-majątkowej w zależności od wielkości przedsiębiorstwa wykorzystano...
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Zarządzanie wiedzą w małych przedsiębiorstwach oferujących wiedzochłonne usługi biznesowe
PublicationCelem artykułu jest przedstawienie praktyk zarządzania wiedzą oraz czynników wpływających na sukces, bądź porażkę w ich wdrażaniu na podstawie badania jakościowego przeprowadzonego w trzech firmach działających na terenie województwa pomorskiego. Firmy te należą do sektora małych i średnich przedsiębiorstw oraz oferują wiedzochłonne usługi biznesowe (knowledge-intensive business services – KIBS). W artykule podjęto próbę odpowiedzi...
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Characteristics of La0.8Sr0.2Ga0.8Mg0.2O3-delta -supported micro-tubular solid oxide fuel cells with bi-layer and tri-layer electrolytes
PublicationIn this study, La0.8Sr0.2Ga0.8Mg0.2O3−δ (LSGM)-supported micro tubular solid oxide fuel cells (T-SOFCs) with two different configurations, one containing an LSGM–Ce0.6La0.4O2−δ (LDC) bi-layer electrolyte (Cell A) and one containing an LDC–LSGM–LDC tri-layer electrolyte (Cell B), were fabricated using extrusion and dip-coating. After optimizing the paste formulation for extrusion, the flexural strength of the dense and uniform LSGM...
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High Resolution Sea Ice Floe Size and Shape Data from Knox Coast, East Antarctica
PublicationThis dataset contains floe size distribution data from a very high resolution (pixel size: 0.3 m) optical satellite image of sea ice, acquired on 16 Feb. 2019 off the Knox Coast (East Antarctica). The image shows relatively small ice floes produced by wave-induced breakup of landfast ice between Mill Island and Bowman Island. The ice floes are characterised by a narrow size distribution and angular, polygonal shapes, typical...
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Molecular detection of Candida krusei
PublicationThe species identification of fungi belonging to genus Candida is an important issue as this genus becomes the emerging problem of nosocomial infections. As Candida krusei presents intrinsicresistance to the fluconazole that is the drug of the first choice in case of invasive candidiasis the PCR identifying the DNA of C. krusei was elaborated. The analytical sensitivity of the assay on spiked blood samples was estimated at 3-5...
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Wireless intelligent audio-video surveillance prototyping system
PublicationThe presented system is based on the Virtex6 FPGA and several supporting devices like a fast DDR3 memory, small HD camera, microphone with A/D converter, WiFi radio communication module, etc. The system is controlled by the Linux operating system. The Linux drivers for devices implemented in the system have been prepared. The system has been successfully verified in a H.264 compression accelerator prototype in which the most demanding...
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Multi-source-supplied parallel hybrid propulsion of the inland passenger ship STA.H. Research work on energy efficiency of a hybrid propulsion system operating in the electric motor drive mode
PublicationIn the Faculty of Ocean Engineering and Ship Technology, Gdansk University of Technology, design has recently been developed of a small inland ship with hybrid propulsion and supply system. The ship will be propelled by a specially designed so called parallel hybrid propulsion system. The work was aimed at carrying out the energy efficiency analysis of a hybrid propulsion system operating in the electric motor drive mode and at...
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Usage of the Gstreamer framework for generation, analysis, processing and visualization of sonar signal
PublicationIn this paper a novel method of the bearing estimation in a passive sonar system with a towed array is introduced. The classical approach of the bearing estimation based on the spatial spectrum is extended by using the synchrosqeezing method that is a part of the reassignment method introduced by Kodera et al. The usage of this method leads to the precise bearing estimation. The proposed method requires a relatively small amount...
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THE SYNCHROSQUEEZING METHOD IN BEARING ESTIMATION OF STATIONARY SIGNALS FOR PASSIVE SONAR WITH TOWED ARRAY
PublicationIn this paper, a novel method of bearing estimation in a passive sonar system with a towed array is introduced. The classical approach of bearing estimation based on the spatial spectrum [1] is extended by using the synchrosqeezing method that is a part of the reassignment method introduced by Kodera et al. [2]. Using this method leads to a precise bearing estimation. The proposed method requires a relatively small amount of computation,...
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Dilemmas associated with the implementation of quality management systems in Polish smaller health care units
PublicationThe article presents the considerations and recommendations for the implementation of the process-oriented quality management systems (QMS) in small health care units. As an example, the unit providing services for children with disabilities (therapy and rehabilitation) localized in northern part of Poland have been selected. The essential elements of the implementation of the quality system, taking into account the objectives...
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Central heating temperature control algorithm for systems with condensing boilers
PublicationThe problem of control of a central heating system in a small residence is considered. It is assumed that the system is based on a condensing boiler. Since the boiler efficiency depends on a returning water temperature, the proposed control goal is to provide proper air temperature in the residence as well as the lowest possible water temperature. The proposed algorithm is applied to two buildings. Both of them have the same heating...
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Study of the Flow Dynamics of Surface Water Masses in the Area of the Coastal Gulf of Gdansk
PublicationThe paper describes two methods of predicting the movement of small objects with surface water masses. One of the methods uses graph theory to describe the motion of water masses in port docks. The results of this study were compared to a simulation using the hydrodynamic numerical model M3D. The results obtained in a virtual environment were related to the experiments in the real world. In the coastal area of the Gulf of Gdansk,...
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Monitoring of the Process of System Information Broadcasting in Time
PublicationOne of the problems of quantum physics is how a measurement turns quantum, noncopyable data, towards copyable classical knowledge. We use the quantum state discrimination in a central system model to show how its evolution leads to the broadcasting of the information, and how orthogonalization and decoherence factors allow us to monitor the distance of the state in question to the one perfectly broadcasting information, in any...
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A Concept and Design Optimization of Compact Planar UWB Monopole Antenna
PublicationA novel structure concept of a compact UWB monopole antenna is introduced together with a low-cost design optimization procedure. Reduced footprint is achieved by introduction of a protruded ground plane for current path increase and a matching transformer to ensure wideband impedance matching. All geometrical parameters of the structure are optimized simultaneously by means of surrogate based optimization involving variable-fidelity...
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Experimental Research on Insufficient Water Lubrication of Marine Stern Tube Journal Bearing with Elastic Polymer Bush
PublicationWater-lubricated bearings with polymer bushes are steadily gaining popularity due to their advantages, including environmental friendliness, relatively simple construction and long-term operation. Nevertheless, in practice instances of damage to such bearings occur due to insufficient or absent flow of the lubricating agent. In this study, experimental tests established that elastic polymer bush bearing is capable of operating...
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Studies of the separation performance of silanized silica gel for simulated distillation
PublicationWe present the results of investigations of the chromatographic (sorptive) properties of silanized silica gel as a stationary phase for gas chromatography used for simulated distillation. Commercially available silanized sorbent (particle diameter range 63–200 m, average pore size 60 Å) was sieved to obtain the 80–100 mesh fraction (180–150 m). The obtained results revealed that silanized silica gel allows the complete separation...
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Ordered titanium templates functionalized by gold films for biosensing applications – Towards non-enzymatic glucose detection
PublicationRecently, metal nanostructures evoke much interest due to application potential in highly sensitive detectors in biochemistry and medical diagnostics. In this work we report on preparation and characteristics of thin (1–100 nm) Au films deposited onto highly ordered structured titanium templates for SERS (Surface Enhanced Raman Spectroscopy) and electrochemical sensing. The Ti templates are formed by selective removal of TiO2 nanotubes...