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Search results for: GRAVITY, SEA MEASUREMENTS, EARTH, GEOLOGIC MEASUREMENTS, SEA SURFACE, MATHEMATICAL MODEL
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Niobate in silicate and phosphate glasses: Effect of glass basicity on crucible dissolution
PublicationUsing niobium crucibles for melting phosphate and silicate glasses of various modifier oxide contents, and therefore varying optical basicity (Λ), was found to result in varying dissolution rates of niobate during melting. Because of their high electronic polarizability, even small concentrations of niobates are detectable in the Raman spectra of glasses. Even less than 1 mol% Nb2O5 can be identified, as independently confirmed...
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Evaluation of citric acid corrosion inhibition efficiency and passivation kinetics for aluminium alloys in alkaline media by means of dynamic impedance monitoring
PublicationA novel approach is proposed for constructing the adsorption isotherm in corrosion studies, based on a well-known interaction between citric acid and aluminium in alkaline electrolytes. Our approach utilizes the instantaneous impedance measurements via Dynamic Electrochemical Impedance Spectroscopy in galvanostatic mode (g-DEIS). Unlike other common tools, g-DEIS delivers exact information about the concentration required for full...
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The Concept of Accuracy Analysis of the Vertical Displacements Gained from the Hydrostatic Levelling Systems’ Measurements
PublicationAbstract: Nowadays, hydrostatic levelling is a widely used method for the vertical displacements’ determinations of objects such as bridges, viaducts, wharfs, tunnels, high buildings, historical buildings, special engineering objects (e.g., synchrotron), sports and entertainment halls. The measurements’ sensors implemented in the hydrostatic levelling systems (HLSs) consist of the reference sensor (RS) and sensors located on the...
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Isothermal Vulcanization and Non-Isothermal Degradation Kinetics of XNBR/Epoxy/XNBR-g-Halloysite Nanotubes (HNT) Nanocomposites
PublicationThe effect of several concentrations of carboxylated nitrile butadiene rubber (XNBR) functionalized halloysite nanotubes (XHNTs) on the vulcanization and degradation kinetics of XNBR/epoxy compounds were evaluated using experimental and theoretical methods. The isothermal vulcanization kinetics were studied at various temperatures by rheometry and differential scanning calorimetry (DSC). The results obtained indicated that the...
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Manoeuvring forces on azimuthing podded propulsor model
PublicationThis paper presents the preliminary part of comprehensive manoeuvring open- water tests of a gas carrier model. The paper focuses on open water experiments with an azimuthing podded propulsor. The test program was carried out in the cavitation tunnel and the large towing tank of Ship Hydromechanics Division, Ship Design and Research Centre, Gdańsk. The pod was tested as a pushing unit with a 161.3 mm diameter propeller. Steering...
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Optimising approach to designing kernel PCA model for diagnosis purposes with and without a priori known data reflecting faulty states
PublicationFault detection plays an important role in advanced control of complex dynamic systems since precise information about system condition enables efficient control. Data driven methods of fault detection give the chance to monitor the plant state purely based on gathered measurements. However, they especially nonlinear, still suffer from a lack of efficient and effective learning methods. In this paper we propose the two stages learning...
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An Off-Body Narrowband and Ultra-Wide Band Channel Model for Body Area Networks in a Ferryboat Environment
PublicationIn the article an off-body narrowband and ultra-wide band channel model for body area networks in a ferryboat environment is described. Considering the limited number of publications there is a need to develop an off-body channel model, which will facilitate the design of radio links, both from the multimedia services provider and the security point of view, for body area networks in this atypical environment. A mobile heterogeneous...
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Estimation of DC motor parameters using a simple CMOS camera
PublicationDifferent components of control systems for mobile robots are based on dynamic models. In low-cost solutions such a robot is wheeled and equipped with DC motors, which have to be included in the model of the robot. The model is fairly simple but determination of its parameters needs not to be easy. For instance, DC motor parameters are typically identified indirectly using suitable measurements, concerning engine voltage, current,...
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Uniwersalny program komputerowy do projektowania zmiany kierunku trasy
PublicationW pracy przedstawiono kolejny program komputerowy stanowiący implementację algorytmu obliczeniowego dotyczącego projektowania zmiany kierunku trasy kolejowej, dostosowanego do techniki ciągłych pomiarów satelitarnych. Program ten ma charakter uniwersalny, gdyż w ogólnym przypadku obejmuje wprowadzenie do układu geometrycznego dwóch łuków kołowych o różnym promieniu, czyli zastosowanie łuku koszowego. Może się to okazać szczególnie...
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Accident susceptibility index for a passenger ship-a framework and case study
PublicationThe continuous monitoring and assessment of operational vulnerability and accident susceptibility of passenger ships is crucial from the perspective of ship and passenger safety. Despite the existing solutions for vulnerability monitoring, stemming mainly from watertight door operations, a comprehensive framework for accident susceptibility assessment and monitoring is missing in the literature. Therefore, this paper offers a...
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Features of load and wear of main propulsion devices on sea-going ships with piston combustion engines and their impact on changes in technical states of the systems
PublicationThe paper presents the specificity of operation of propulsion systems of seagoing ships which causes the need to control the load on them, especially on their engines called main engines. The characteristics of the load on the propulsion systems, especially on the main engines as well as on the shaft lines and propellers driven by the engines, along with the process of wear in tribological joints (sliding tribological systems)...
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The voltage on bus bars of the main switchboard of the ferry electrical power system during a layover at the port
Open Research DataThe dataset is part of the research results on the quality of supply voltage on bus bars of the main switchboard of the ship's electrical power system in different states of ship exploitation. The attached dataset contains the measurement results carried out onboard the ferry during a layover at the port.
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Injury Prediction Models for Onshore Road Network Development
PublicationIntegrating different modes of transport (road, rail, air and water) is important for port cities. To accommodate this need, new transport hubs must be built such as airports or sea ports. If ports are to grow, they must be accessible, a feature which is best achieved by building new roads, including fast roads. Poland must develop a network of fast roads that will provide good access to ports. What is equally important is to upgrade...
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Cathodic activation of synthesized highly defective monoclinic hydroxyl‐functionalized ZrO2 nanoparticles for efficient electrochemical production of hydrogen in alkaline media
PublicationThe high electrochemical stability of Zirconia (ZrO2) at high potentials strongly suggested it as an alternative to carbon supports, which experience reduced efficiency due to some corrosion problems particularly during prolonged electrocatalysis activity. However, the use of ZrO2 was limited by its low electrical conductivity and surface area. In this work, we developed a methodology for synthesizing monoclinic ZrO2 NPs with increased...
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Power Hardware-In-the-Loop Approach for Autonomous Power Generation System Analysis
PublicationThe article presents the Power Hardware-In-the-Loop (PHIL) dynamic model of a synchronous generator of 125 kVA for autonomous power generation system analysis. This type of system is typically composed of electrical energy sources in the form of several diesel generator units with synchronous machines, the main distribution switchboard and different loads. In modern power distribution systems, the proposed power management strategies...
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Heat transfer characteristics of hybrid microjet – Microchannel cooling module
PublicationThe paper presents experimental investigation of heat transfer intensification in a microjet–microchannel cooling module. Applied technology takes benefits from two very attractive heat removal techniques. When jets are impinging on the surface, they have a very high kinetic energy at the stagnation point, also in microchannels boundary layer is very thin allowing to obtain very high heat fluxes. Main objective of this paper was...
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Separation of the effects of notch and macro residual stress on the MFL signal characteristics
PublicationMagnetic flux leakage (MFL) distribution for three configurations of samples has been investigated in order to study the influence of notch and plastic deformation separately as well as together. Samples have been made of S355 steel. The MFL signal measurements were carried out along the longest dimension of the sample over a length of 120 mm. Two components of magnetic field were measured: 1) tangential to the main axis and 2)...
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Assessment of the impact of bacteria Pseudomonas denitrificans, Pseudomonas fluorescens, Bacillus subtilis and yeast Yarrowia lipolytica on commercial poly(ether urethanes)
PublicationThe assessment of the impact of the bacteria Pseudomonas denitrificans, Pseudomonas fluorescens, Bacillus subtilis and yeast Yarrowia lipolytica on commercial poly(ether urethanes) Tecoflex® and Tecothane® is presented. The polyurethane samples were incubated with pure cultures of the microorganisms at 30 °C for five months. The changes in the chemical structure of the polymers were evaluated using loss of weight and contact angle...
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The valance state of vanadium-key factor in the flexibility of potassium vanadates structure as cathode materials in Li-ion batteries
PublicationPotassium hexavanadate (K2V6O16·nH2O) nanobelts have been synthesized by the LPE-IonEx method, which is dedicated to synthesis of transition metal oxide bronzes with controlled morphology and structure. The electrochemical performance of K2V6O16·nH2O as a cathode material for lithium-ion batteries has been evaluated. The KVO nanobelts demonstrated a high discharge capacity of 260 mAh g−1, and long-term cyclic stability up to 100...
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A Study of Mutual Coupling Suppression between Two Closely Spaced Planar Monopole Antenna Elements for 5G New Radio Massive MIMO System Applications
Publication5G NR (new radio) introduces the concept of massive MIMO (multiple-input-multiple-output) technology, in which a larger number of antenna arrays are installed on the transceiver. Due to the increased number of antenna elements allocated close to each other (approximately at half-wavelength distance), mutual coupling becomes a serious problem leading to performance degradation of the MIMO communication system. In this communication,...
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Application of adjusted subpixel method (ASM) in HRCT measurements of the bronchi in bronchial asthma patients and healthy individuals
PublicationBackground: Recently, we described a model system which included corrections of high-resolution computedtomography (HRCT) bronchial measurements based on the adjusted subpixel method (ASM).Objective: To verify the clinical application of ASM by comparing bronchial measurements obtained bymeans of the traditional eye-driven method, subpixel method alone and ASM in a group comprised ofbronchial asthma patients and healthy individuals.Methods:...
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Transmission parameters of underwater communication channels
PublicationThe underwater environment is tough and demanding as a communication channel for ultrasonic signals. The channel transmission characteristics in marine and inland waters depend much on local bathymetry and changing weather conditions. The architecture and performance of a reliable underwater acoustic communication (UAC) system should allow real-time adaptation of its transmission parameters to a large variety of possible channel...
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Statistically efficient smoothing algorithm for time-varying frequency estimation
PublicationThe problem of extraction/elimination of a nonstationary sinusoidal signal from noisy measurements is considered. This problem is usually solved using adaptive notch filtering (ANF) algorithms. It is shown that the accuracy of frequency estimates can be significantly increased if the results obtained from ANF are backward-time filtered by an appropriately designed lowpass filter. The resulting adaptive notch smoothing (ANS) algorithm...
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Investigation of the road noise source employing an automatic noise monitoring station
PublicationThe paper presents a pilot investigation of noise source models in two selected localizations in the context of future dynamic noise map creation. The experiments were carried out using the automatic noise monitoring station engineered at the Multimedia Systems Departmentof the Gda´nsk University of Technology. The results of the noise measurements employing monitoring stations and its comparison to the reference values are depicted....
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Superconductivity in the superhard boride WB4.2
PublicationWe show that the superhard boride WB4.2 is a superconductor with a Tc of 2.05(5) K. Temperature-dependent magnetic susceptibility, electrical resistivity, and specific heat measurements were used to characterize the superconducting transition. The Sommerfeld constant γ for WB4.2 is 2.07(3) mJ mol−1 K−2 and the ΔC/γTc=1.56, which is somewhat higher than what is expected for weakly coupled Bardeen–Cooper–Schrieffer type superconductors....
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Low-energy positron collisions with water: elastic and rotationally inelastic scattering
PublicationDifferential, integral and momentum transfer cross sections for the vibrationally elastic and rotationally inelastic scattering of positrons from water at low collision energy (E ≤ 10 eV) are reported. Several models within the R-matrix method are used to compute the body-fixed T-matrices, while the scattering calculations are performed within the fixed-nuclei approximation corrected with the standard Born-closure formula. These...
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Fading Characteristics for Dynamic Body-to-Body Channels in Indoor and Outdoor Environments
PublicationThis paper presents an analysis of the fading characteristics in dynamic body-to-body channels, based on measurements performed at 2.45 GHz in indoor and outdoor environments. The statistical analysis of the small- and large-scale fading shows that the Nakagami Distribution is the best model for the former and the Log-Normal one for the latter. An important influence of body shadowing...
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Electrical characterization of diamond/boron doped diamond nanostructures for use in harsh environment applications
PublicationThe polycrystalline boron doped diamond (BDD) shows stable electrical properties and high tolerance for harsh environments (e.g. high temperature or aggressive chemical compounds) comparing to other materials used in semiconductor devices. In this study authors have designed electronic devices fabricated from non-intentionally (NiD) films and highly boron doped diamond structures. Presented semiconductor devices consist of highly...
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Antibacterial Porous Systems Based on Polylactide Loaded with Amikacin
PublicationThree porous matrices based on poly(lactic acid) are proposed herein for the controlled release of amikacin. The materials were fabricated by the method of spraying a surface liquid. Description is given as to the possibility of employing a modifier, such as a silica nanocarrier, for prolonging the release of amikacin, in addition to using chitosan to improve the properties of the materials, e.g., stability and sorption capacity....
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Enhanced photoelectrochemical and photocatalytic performance of iodine-doped titania nanotube arrays
PublicationThe paper discusses the synthesis and performance of iodine doped titania nanotube arrays exhibited under irradiation. The doping procedure was performed as an additional, electrochemical process carried out after formation of nanotube arrays via anodization of Ti substrate. The optical and structural properties were characterized using Raman, UV-vis, photoluminescence and X-ray photoelectron spectroscopy. The surface morphology...
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Pilot-Scale Studies of WO3/S-Doped g-C3N4 Heterojunction toward Photocatalytic NOx Removal
PublicationDue to the rising concentration of toxic nitrogen oxides (NOx) in the air, effective methods of NOx removal have been extensively studied recently. In the present study, the first developed WO3/S-doped g-C3N4 nanocomposite was synthesized using a facile method to remove NOx in air efficiently. The photocatalytic tests performed in a newly designed continuous-flow photoreactor with an LED array and online monitored NO2 and NO system...
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Ultrasensitive electrochemical determination of the cancer biomarker protein sPD-L1 based on a BMS-8-modified gold electrode
PublicationThis work describes the modification of a gold electrode with the BMS-8 compound that interacts with the Programmed Death-Ligand 1 (PD-L1), an immune checkpoint protein. The results show that we can confirm the presence of the sPD-L1 in the concentration range of 10−18 to 10−8 M using electrochemical impedance spectroscopy (EIS) with a limit of detection (LOD) of 1.87 × 10−14 M for PD-L1 (S/N = 3.3) and at a concentration of 10−14...
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The abrasive wear resistance of coatings manufactured on high-strength low-alloy (HSLA) offshore steel in wet welding conditions
PublicationSome marine and offshore structure elements exploited in the water cannot be brought to the surface of the water as this will generate high costs, and for this reason, they require in-situ repairs. One of the repair techniques used in underwater pad welding conditions is a wet welding method. This paper presents an investigation of the abrasive wear resistance of coatings made in wet welding conditions with the use of two grades...
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Impact of Tetrazolium Ionic Liquid Thermal Decomposition in Solvothermal Reaction on the Remarkable Photocatalytic Properties of TiO2 Particles
PublicationIonic liquids (ILs) could serve as a structuring agent, a solvent, or a source of dopant during solvothermal synthesis of semiconductors particles. To understand the role of IL during formation of TiO2 particles, it is necessary to study the stability of this IL in solvothermal synthesis conditions, as well as studying the surface properties of formed TiO2 particles. In view of this, the effect of the 2,3,5-triphenyltetrazolium...
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Controlling the size and morphology of precipitated calcite particles by the selection of solvent composition
PublicationCalcium carbonate particles were obtained in the reaction of calcium hydroxide with carbon dioxide at 65°C. Initial Ca(OH)2 suspensions were prepared in pure water and aqueous solutions of ethylene glycol or glycerol of the concentration range up to 20% (vol.). The course of reaction was monitored by conductivity measurements. Precipitated solids were analyzed by FTIR, XRD, SEM and the particles size distribution was determined...
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A Wideband Channel Model for Body Area Networks in Circular Metallic Indoor Environments
PublicationIn this paper, the wideband characterization of the propagation channel in circular metallic indoor environments is addressed, regarding Body Area Networks and 5G small cells, an analytical model for the dependence of the mean delay and the average delay spread on the circle radius, the working frequency and the distance between the transmitter and the receiver being proposed. The derivation of the model is initially done analytically,...
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Novel hierarchical nonlinear control algorithm to improve dissolved oxygen control in biological WWTP
PublicationWastewater treatment is a problem known to humankind for centuries. The quality of treated sewage determines the condition of reservoirs around the world. Control of such a complex and nonlinear system as a wastewater treatment plant requires thorough knowledge of the process. The paper presents a hierarchical control system of a Sequencing Batch Reactor (SBR) in Wastewater Treatment Plant (WWTP) taking into account a model based...
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Przekształtnik prądu jako sterownik w układach napędowych z silnikami indukcyjnymi
PublicationThe circuits used for power conversion applied in drives with electric machines are classified into two groups: voltage source inverters (VSI) and current source inverters (CSI). Application of the current source inverter results in better properties of drive than application of voltage source inverter because there is no output filter. The development of power electronics and especially the IGBTs, in which on/off-times are very...
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Sawing Processes as a Way of Determining Fracture Toughness and Shear Yield Stresses of Wood
PublicationA new computational model, based on fracture mechanics, was used to determine cutting forces. Unlike traditional computing methods, which depend on many coefficients reflecting the machining of solid wood, the new model uses two main parameters: fracture toughness and shear yield stresses. The aim of this study was to apply this new method to determine these parameters for the tooth cutting edge principal positions and longitudinal...
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Influence of User Mobility and Antenna Placement on System Loss in B2B Networks
PublicationIn this paper, the influence of user mobility and on-body antenna placement on system loss in body-to-body communications in indoor and outdoor environments and different mobility scenarios is studied, based on system loss measurements at 2.45 GHz. The novelty of this work lies on the proposal of a classification model to characterise the effect of user mobility and path visibility on system loss, allowing to identify the best...
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Improvement of Thrust Bearing Calculation Considering the Convectional Heating within the Space between the Pads
PublicationA modern thrust bearing tool is used to estimate the behavior of tilting pad thrust bearings not only in the oil film between pad and rotating collar, but also in the space between the pads. The oil flow in the space significantly influences the oil film inlet temperature and the heating of pad and collar. For that reason, it is necessary to define an oil mixing model for the space between the pads. In the bearing tool, the solutions...
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Fading Modeling in Maritime Container Terminal Environments
PublicationIn this paper, an analytical model for slow and fast fading effects in maritime container terminals is derived, from fitting distributions to the results of measurements performed in an actual operational environment. The proposed model is composed of a set of equations, enabling to evaluate fading statistical distribution parameters for different system and environments conditions, as a function of frequency, base station antenna...
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Distribution of relaxation times as a method of separation and identification of complex processes measured by impedance spectroscopy
PublicationImpedance spectroscopy is one of the most commonly performed measurements to characterize electronic and electrochemical systems. Impedance spectra have limited resolution and many different processes may overlap what could be the reason of obstructions in its proper later analysis. Up to date, there are three approaches to solve this problem: examining impedance spectra itself, fitting spectra with equivalent circuits, and calculating...
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Współczesne metody zapewniania jakości oprogramowania. Od klasyki do zwinności
PublicationKsiążka opisuje problematykę jakości w kontekście metod wytwarzania oprogramowania. Składa się z 22 rozdziałów podzielonych na 6 części: Znaczenie jakości oprogramowania, Podstawowe pojęcia i problemy jakości, Jakość w ujęciu klasycznym, Pomiary jakości, Dokumentacja i normy jakości procesu, Jakość w podejściu zwinnym. Zebrany materiał pokazuje ewolucję podejścia do jakości w klasycznych metodykach wytwarzania (od modelu kaskadowego...
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Correlation–polarization effects in electron/positron scattering from acetylene: A comparison of computational models
PublicationDifferent computational methods are employed to evaluate elastic (rotationally summed) integral and differential cross sections for low energy (below about 10 eV) positron scattering off gas-phase C2H2 molecules. The computations are carried out at the static and static-plus-polarization levels for describing the interaction forces and the correlation–polarization contributions are found to be an essential component for the correct...
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Predicting sulfanilamide solubility in the binary mixtures using a reference solvent approach
PublicationBackground. Solubility is a fundamental physicochemical property of active pharmaceutical ingredients. The optimization of a dissolution medium aims not only to increase solubility and other aspects are to be included such as environmental impact, toxicity degree, availability, and costs. Obtaining comprehensive...
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A system for Direction-Of-Arrival estimation in ISM 2.4 GHz frequency band based on ESPAR antenna and SDR technology
PublicationDetermination of the direction of the signal arrival (DOA) finds many applications in various areas of science and industry. Knowledge of DOA is used, among others to determine the position of a satellite with a low Earth orbit (LEO), localization of people and things as well as in research of wireless communication systems, for instance the determination of the number of...
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Comparison of hydrochemistry and organic compound transport in two non-glaciated high Arctic catchments with a permafrost regime (Bellsund Fjord, Spitsbergen)
PublicationAn increase in air temperature related to climate change results in the retreat of glaciers, the degradation of permafrost, and the expansion of glacier-free areas in the polar regions. All these processes lead to changes in the Arctic landscape. They influence the hydrochemistry of streams and rivers fed by glaciers and thawing permafrost. In this study, we examine eighty two water samples from two non-glaciated catchments with...
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Internet photogrammetry for inspection of seaports
PublicationThis paper intends to point out the possibility of using Internet photogrammetry to construct 3D models from the images obtained by means of UAVs (Unmanned Aerial Vehicles). The solutions may be useful for the inspection of ports as to the content of cargo, transport safety or the assessment of the technical infrastructure of port and quays. The solution can be a complement to measurements made by using laser scanning and traditional...
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Measurements of guided wave propagation in CFRP/steel adhesive joints obtained by scanning laser vibrometry
Open Research DataThe DataSet contains guided wave signals measured in adhesive joints of steel plates (steel of type S355 with a thickness of 11.9 mm ) and carbon fibre reinforced polymer (CarboDur S1012 with a thickness of 1.24 mm). The samples were as follows: #0 – intact; #1 – 10% disbond; #2 – 20% disbond; #3 – 50% disbond; #4 – 80% disbond; #5 – 100% disbond.