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Search results for: LOW-VOLTAGE GRID ANALYSIS
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Single crystal growth and physical properties of MCo2Al9 (M= Sr, Ba)
PublicationSingle crystals of SrCo2Al and BaCo2Al9 were grown using a self-flux method. A LeBail analysis of the powder X-ray diffraction patterns show that both compounds crystallize in a hexagonal (P6/mmm) crystal structure with lattice parameters: a = 7.8995(1) Å, c = 3.9159(1) Å for SrCo2Al9, and a = 7.9162(2) Å, c = 3.9702(1) Å for BaCo2Al9 aluminide. The low temperature analysis of the heat capacity measurements give a Sommerfeld...
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Synthesis and structure of Bi 5 FeTi 3 O 15 ceramics
PublicationAim of the present research was to fabricate and study crystal structure and phase composition of Bi5FeTi3O15 (BTFO) ceramics exhibiting Aurivillius - type structure. By means of simultaneous thermal analysis and X-ray diffraction analysis the process of synthesis of BTFO ceramics has been studied. Mixed oxide method followed by pressureless sintering was used for ceramics preparation. Three endothermic thermal effects have been...
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High-conducting Bi4V2-xFexO11-δ ceramics containing Fe2O3 nanocrystals: Structure and properties
PublicationThe topography, structure, thermal, magnetic, and electrical properties of Bi4V2-xFexO11-δ ceramics substituted with x = 0.5 and 0.7 Fe were studied. The microscope analysis showed the presence of iron-rich nanocrystals formed on the Bi-Fe-V-O grains. The X-ray diffraction studies confirmed that grains are built mostly of tetragonal Bi4V1.5Fe0.5O10.5 phase. Thermal properties analysis showed an order-disorder type γ ↔ γʹ phase...
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Analiza bibliometryczna w badaniach dotyczących prognozowania upadłości przedsiębiorstw w Polsce
PublicationCelem opracowania jest ukazanie obrazu piśmiennictwa poświęconego zagadnieniom prognozowania upadłości przedsiębiorstw w Polsce. Jako metodę badawczą zastosowano analizę bibliometryczną. Do analizy wykorzystano bazę Google Scholar oraz narzędzie Publish or Perish 7. Okresem badań objęto lata 1995– 2019. Jako frazy do wyszukiwania publikacji zastosowano: „prognozowanie upadłości”, „prognozowanie zagrożenia finansowego”, „systemy...
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CMOS implementation of an analogue median filter for image processing in real time
PublicationAn analogue median filter, realised in a 0.35 μm CMOS technology, is presented in this paper. The key advantages of the filter are: high speed of image processing (50 frames per second), low-power operation (below 1.25 mW under 3.3 V supply) and relatively high accuracy of signal processing. The presented filter is a part of an integrated circuit for image processing (a vision chip), containing: a photo-sensor matrix, a set of...
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A multistage turbine for a micro power plant
PublicationThis paper presents results of a design analysis of a multi-stage turbine for the cogeneration micro-power plant working in accordance with Organic Rankine Cycle (ORC). The heat power of the plant is assumed equal to 20 kW and the corresponding available electric output is estimated to be of about 3 kW. Different variants of the radial and axial-flow turbines have been considered, while the detailed results of the calculations...
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New data acquisition system for birch sap concentrate production using the reverse osmosis technology
PublicationThe work presents a simple electronic device that helps to monitor the basic parameters of the reverse osmosis (RO) system during the concentration of birch tree sap. The construction costs are low (around 150 Euro) but the functionality of the device is high. It has an in-build two channel conductometer and can measure the volumetric flow rate of two streams of liquids. The collected data are transmitted wirelessly via Bluetooth...
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Wet H2S corrosion and degradation of pipeline in amine regeneration system
PublicationThe paper presents the results of NDT examinations, metallographic tests and risk assessment of degradation related to corrosion of amine regeneration unit in a desulphurisation system. Intensive corrosion resulting from acid gases environment upon water condensation causes perforation of the pipeline. Detailed analysis reveals cracking related to the mechanism of wet H2S. Hydrogen penetration, resulting from the wet H2S process,...
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Probability distribution of flicker noise in AuNPdecorated graphene–Si Schottky barrier diode
PublicationWe present results of the probability distribution analysis of flicker noise generated in Au nanoparticle (AuNP) decorated graphene–Si Schottky barrier diodes with and without yellow light illumination (592 nm), close to the localized surface plasmon resonance in the AuNPs (586 nm). The AuNPs occupy imperfections in the single-layer graphene and reduce the flicker noise intensity generated in the graphene layer. The estimated probability...
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Sensors integration in the smart home environment - a proposal to solve the problem with user identification
PublicationIn this preliminary study we, investigate the possibility of user recognition techniques suitable on smart home devices like chairs, beds, aiming for low–power, high accuracy and quick response time. We propose the two well know technique: voice speaker recognition and accelerometer signal from device mounted on the chair, and the third one optical system basing on IR LED transmitter/receiver circuit. The preliminary results proved...
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Impact of thermal loading into the structural performance of ships: A review
PublicationThe presented study reviews the recent advances done regarding the impact of thermal loading on the structural performance of ships. Firstly, the studies related to the mechanical and thermal properties of typical materials used in shipbuilding are outlined. Secondly, a brief introduction to the heat transfer analysis, Finite Element modelling and thermal stresses is provided. Finally, the review of papers dealing with the structural...
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Analysis of energy efficiency of suburban railway transport network
PublicationRising numbers of agglomeration residents cause increased need for people movement on daily basis. Because of congestion of local roads, air pollution and limited parking space, providing mass transit based on electric traction is reasonable. While the electric rail vehicles are considered highly efficient in themselves, they need to be analyzed as a part of a transport network, because energy consumption depends on operating conditions...
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Time window based features extraction from temperature modulated gas sensors for prediction of ammonia concentration
PublicationElectronic gas recognition systems, in literature commonly referred as electronic noses, enable the recognition of a type and a concentration of various volatile compounds. Typical electronic gas-analyzing device consists of four main elements, namely, gas delivery subsystem, an array of gas sensors, data acquisition and power supply circuits and data analysis software. The commercially available metal-oxide TGS sensors are widely...
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Analytical applications of smartphones for agricultural soil analysis
PublicationSoil is one of the most important farming resources. Appropriate managing of its quality promotes productive and sustainable agriculture. The valuable farm practice in soil quality managing is based on regular soil analysis with the aim to determine the exact amount of nutrients or other chemical, physical and biological soil properties. Soil analysis usually requires samples collection at desired sampling depth following by samples...
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Combination of instrumental and qualitative descriptive analysis for evaluation of selected tonic waters quality features
PublicationThe combination of sensory and instrumental analysis was applied for quality assurance of selected tonic waters. The Quantitative Descriptive Analysis (QDA) in terms of fourteen sensory attributes (aroma, astringency, bite, burn, numbing, tongue heaviness, carbonation, mouth coating, sweet taste, sour taste, bitter taste, sweet aftertaste, sour aftertaste, bitter aftertaste) of selected tonic waters was performed by sensory experts....
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The low-frequency magnetic field emissions on-board of the vessel
Open Research DataThe data represents measurement results performed on board of the vessel. The acquired time-waveforms, corresponding to the instantaneous values of the magnetic field (MF) induction were acquired near the cable supplying the bow thruster motor. Data recording of the magnetic field density (MFD) emissions was carried out with a/d converters of the data...
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A Compact Basis for Reliable Fast Frequency Sweep via the Reduced-Basis Method
PublicationA reliable reduced-order model (ROM) for fast frequency sweep in time-harmonic Maxwell’s equations by means of the reduced-basis method is detailed. Taking frequency as a parameter, the electromagnetic field in microwave circuits does not arbitrarily vary as frequency changes, but evolves on a very low-dimensional manifold. Approximating this low-dimensional manifold by a low dimension subspace, namely, reduced-basis space, gives...
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Recent progress in ultra-low formaldehyde emitting adhesive systems and formaldehyde scavengers in wood-based panels: a review
PublicationTraditional wood-based panels are produced with synthetic, formaldehyde-based adhesives, commonly made from fossil-derived constituents, such as urea, phenol, melamine, etc. Along with their numerous advantages, such as chemical versatility, high reactivity and excellent adhesive performance, these adhesives are characterized by certain problems, connected with the hazardous volatile organic compounds (VOCs), mostly free formaldehyde...
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Switched-capacitor DC-DC converters in arbitrary switching mode - topologically derived resistive models based on incremental graph approach.
PublicationIn the preceding paper we reviewed some of modeling approaches aimed at systematic formulation and solution of switched capacitor DC-DC converters. In our review, special attention was paid to computationally efficient and mathematically elegant methods. In so doing we had tried to demonstrate the virtues of unified Incremental Graph (IG) approach. Incremental Graph is, in concept, a tool originally created for analysis and synthesis...
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Infrared techniques for natural convection investigations in channels between two vertical, parallel, isothermal and symmetrically heated plates
PublicationThe effect of the gap width between two symmetrically heated vertical, parallel, isothermal plates on intensity of natural convective heat transfer in a gas (Pr = 0.71) was experimentally studied using the balance and gradient methods. In the former method heat fluxes were determined based on measurements of the voltage and electric current supplying the heaters placed inside the walls. In the latter, heat fluxes were calculated...
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Electro-thermal buckling of elastically supported double-layered piezoelectric nanoplates affected by an external electric voltage
PublicationPurpose Thermal buckling of double-layered piezoelectric nanoplates has been analyzed by applying an external electric voltage on the nanoplates. The paper aims to discuss this issue. Design/methodology/approach Double-layered nanoplates are connected to each other by considering linear van der Waals forces. Nanoplates are placed on a polymer matrix. A comprehensive thermal stress function is used for investigating thermal buckling....
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Theoretical designing of selenium heterocyclic non-fullerene acceptors with enhanced power conversion efficiency for organic solar cells: a DFT/TD-DFT-based prediction and understanding
PublicationIn this study, we have designed and explored a new series of non-fullerene acceptors for possible applications in organic solar cells. We have designed four molecules named as APH1 to APH4 after end-capped modification of recently synthesized Y6-Se-4Cl molecule. Density functional theory and time dependent-density functional theory have been employed for computing geometric and photovoltaic parameters of the designed molecules....
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Application of passive sampling techniques as a usable tool in the field of environmental quality monitoring
PublicationAnalysis of literature data published for the past 20 years leads to the conclusion, that passive sampling technique has been developing very quickly and is commonly used in the field of monitoring pollutants in air, water and soil environment. The popularity of application of passive sampling techniques in analytical and environmental chemistry results from its many advantages e.g.: Simplicity in use, low costs of exploitation,...
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Noise measurements on low noise pavements - problems with inhomogeneity of wearing course
PublicationDuring the last several years, when performing numerous CPX noise measurements on low noise pavements,significant inhomogeneity of the wearing course was observed in numerous cases. Similar problems were almost not existing regarding to the dense pavements.In general three main reasons of inhomogeneity can be defined. The first one are imperfections in technology of production of a asphalt mix or/and errors made already during...
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Strain energy density and entire fracture surface parameters relationship for LCF life prediction of additively manufactured 18Ni300 steel
PublicationIn this study, the connection between total strain energy density and fracture surface topography is investigated in additively manufactured maraging steel exposed to low-cycle fatigue loading. The specimens were fabricated using laser beam powder bed fusion (LB-PBF) and examined under fully-reversed strain-controlled setup at strain amplitudes scale from 0.3% to 1.0%. The post-mortem fracture surfaces were explored using a non-contact...
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Understanding the Dominant Physics Mechanisms on the p-i-n Perovskite Solar Cells Fabricated by Scalable Slot-Die Coating Process in Ambient Air
PublicationPerovskite solar cells (PSC) are emerging technologies that have shown continuous improvement in power conversion efficiency (PCE) and stability. However, a very important aspect that has been seldom considered is the reproducibility of PCE of PSC devices. It is possible to achieve PCE from 10.21% to 17.05% using scalable slot-die-coating technique. However, a spatial distribution of performance is clearly observed for device samples...
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Water-mediated influence of a crowded environment on internal vibrations of a protein molecule
PublicationThe influence of crowding on the protein inner dynamics is examined by putting a single protein molecule close to one or two neighboring protein molecules. The presence of additional molecules influences the amplitudes of protein fluctuations. Also, a weak dynamical coupling of collective velocities of surface atoms of proteins separated by a layer of water is detected. The possible mechanisms of these phenomena are described....
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Preparation and characterization of asphaltene based adsorbents for gas-solid adsorption systems
PublicationThe dissertation presents results of the experimental research on asphaltene-based adsorbents (support coated with asphaltene layer) for gas-solid adsorption systems, with special reference to volatile organic compounds (VOCs) removal from gas streams. Analysis of gas adsorption properties revealed that asphaltenes isolated from oxidized bitumen have strong affinity toward VOCs. Interactions with target gas molecules, and selectivity...
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Visible light activity of rare earth metal doped (Er3+, Yb3+ or Er3+/Yb3+) titania photocatalysts
PublicationA series of Er3+-TiO2, Yb3+-TiO2 and Er3+/Yb3+-TiO2 photocatalysts were obtained via sol-gel method, using rare earth metal (RE) precursor ranging from 0.25 to 10 mol%. The experiments demonstrated that phenol in aqueous solutions was successfully degraded under visible light (> 450 nm) using RE3+-TiO2. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron emission spectroscopy (XPS), UV-Vis...
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Rapid assessment of the authenticity of limequat fruit using the electronic nose and gas chromatography coupled with mass spectrometry
PublicationCitrus fruits are very popular food products. There are many species and varieties of them. There are also documented cases of some citrus fruits causing a severe allergic reaction. Some species of the citrus fruits, especially hybrid ones show a reduced allergenic effect due to the lack of seeds. There is a need for rapid methods for evaluation of citrus’ botanical origin. During research, the headspace of three citrus fruits...
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Innovative investment funds and stability of financial systems: Nonparametric study of exchange-traded funds in Europe
PublicationThe main aim of the paper is investigation of the potential contribution of exchange-trade funds (ETFs) to the instability of the European financial systems. The paper begins with presentation of the key theoretical concepts with regard to ETFs and financial stability. We discuss the key attributes of ETFs as the innovative category of investment funds, their hypothesized impact on the financial stability as well as briefly describe...
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The topography of strontium–borate glasses and glass-ceramics containing nanocrystallites of Bi2VO5.5. measured with SEM method
Open Research DataThe topography of strontium–borate glasses and glass-ceramics containing nanocrystallites of Bi2VO5.5. was measured by SEM.
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Tworzenie modelu pojęciowego dla zarządzania ryzykiem na przykładzie procesu laminowania w stoczni jachtowej
PublicationCelem artykułu jest zaproponowanie modelu pojęciowego normalizującego kryteria oceny ryzyka w systemie zarządzania jakością w stoczni jachtowej. Zamiarem jest przeprowadzenie analizy danych, pozwalającej wytyczyć zbiory o wysokim, średnim i niskim poziomie istotności dla wszystkich błędów powstających w procesie laminowania. W artykule skoncentrowano się na najważniejszych pojęciach związanych z ryzykiem i kryteriami jego oceny....
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Coacervative extraction as a green technique for sample preparation for the analysis of organic compounds
PublicationOne of the present trends in analytical chemistry is miniaturization, which is one of the methods of green analytical chemistry application. A particular emphasis is placed on the elimination of the use of large amounts of organic solvents which are toxic and harmful to the environment, maintaining high efficiency of the extraction process, high recovery values and low values of quantification (LOQ) and detection (LOD) limits....
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Study on 19th-century cast iron columns from the former financial office building in Kwidzyn
PublicationThe article presents the results for cast iron columns used as floor supports in the former financial office building in Kwidzyn (Poland).The stocktaking drawings provided the general and detailed data about the 19th century designer’s decisions. During the research, architectural and structural analysis was carried out. The graphics were used as a starting material for preparing 3D calculation models. The FEM-based numerical simulations...
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The conducted EMI in DC-DC converters
PublicationThis book presents the phenomena of conducted electromagnetic interference (EMI) generation in DC-DC converters. The measurement and simulation are used to analyze the impact of the most important parameters on the character, level and propagation path of interference. In this book, the analysis of the interference generation and propagation is presented on the example of three basic converters. The wide banded behavior of all...
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Influence of local bush wear on water lubricated sliding bearing load carrying capacity
PublicationOne of main problems concerning water-lubricated bearings is their durability. There are known cases of bearings with life time measured in decades, and some, whose refurbishment was necessary just days after start-up. Obtaining stable fluid film friction plays key role in the durability of these bearings. Unfortunately, their load-carrying capacity is limited due to water's low-viscosity. The conducted experimental...
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An experimental study of high-hydrogen welding processes
PublicationThis paper presents investigation results of determination of the diffusible hydrogen content in deposited metal obtained by means of two most often used methods-the glycerin method and the mercury method. Relation has been defined between results of those methods in the area characteristic of low-hydrogen as well as high-hydrogen welding processes. Relations available in the literature do not include the diffusible hydrogen content...
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Influence of dopants on structure of polycrystalline bismuth niobate
PublicationBismuth niobate (BiNbO4) has attracted attention as a low-fired ceramics with promising microwave application potential. BiNbO4 ceramics was fabricated by mixed oxide method and sintered at temperature T<1000˚C. As the sintering aids a small amount of CuO oxide was used. The crystalline structure of the ceramic samples was examined by X-ray diffraction method at room temperature. The Rietveld refinement method was used for analysis...
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Speed Observer Structure of Induction Machine Based on Sliding Super-Twisting and Backstepping Techniques
PublicationThis paper presents an analysis of the two speed observer structures which are based on the backstepping and sliding super twisting approach. The observer stabilizing functions result from the Lyapunov theorem. To obtain the observer tuning gains the observer structure is linearized near the equilibrium point. The rotor angular speed is obtained from non-adaptive dependence. In the sensorless control system structure the classical...
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Selected studies of flow maldistribution in a minichannel plate heat exchanger
PublicationAnalysis of the state of-the-art in research of minichannel heat exchangers, especially on the topic of flow maldistribution in multiple channels, has been accomplished. Studies on minichannel plate heat exchanger with 51 parallel minichannels with four hydraulic diameters, i.e., 461 μm, 574 μm, 667 μm, and 750 μm have been presented. Flow at the instance of filling the microchannel with water at low flow rates has been visualized. The...
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Partial Admission Stages of High Efficiency for a Microturbine
PublicationThe paper presents the results of a design analysis of a micro-turbine for a co-generation micro-power plant working in accordance with organic Rankine cycle. The heat power of the plant is assumed equal to 20kW and the corresponding available electric output is estimated to be about 3kW. After the design analysis, the axial turbine with partial admission in all stages was built and tested experimentally. Special attention was...
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Is the Concept of Zero Waste Possible to Implement in Construction?
PublicationThe scientifically treated problem of reusing building materials appeared in the literature more than 50 years ago. This paper includes an analysis of the characteristics of recycled building materials, which is a prerequisite for rational recycling. The analysis and simulation of building stocks at different scales has led to the conclusion that the most important link in the transformation of the construction industry towards...
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A brief note on entire fracture surface topography parameters for 18Ni300 maraging steel produced by LB-PBF after LCF
PublicationThe concept of entire fracture surface investigation is helpful in explaining fatigue phenomena. In this paper, this method has been applied for 18Ni300 maraging steel using a 3D measurement system. Before post-mortem analysis, the specimens produced by laser beam powder bed fusion (LB-PBF) were tested under low-cycle fatigue (LCF) for eight strain amplitudes in the interval 0.3% to 1.0%. The attention was placed on the relationship...
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Partial Admission Stages of High Efficiency for a Microturbine
PublicationThe paper presents the results of a design analysis of a microturbine for a cogeneration micro-power plant working in accordance with organic Rankine cycle. The heat power of the plant is assumed equal to 20kW and the corresponding available electric output is estimated to be about 3 kW. After the design analysis, the axial turbine with partial admission in all stages was built and tested experimentally. Special attentionwas paid...
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Ranking of Generation Source Locations by a Hybrid Multi-Criteria Method
PublicationThe paper presents a ranking of the locations of eight renewable energy sources (RES) made using a hybrid multi-criteria analysis method. The method is a combination of the analytical hierarchical process (AHP) method and numerical taxonomy. The considered generating sources, i.e. solar plants, biogas plants, and wind farms are sources that will significantly contribute to implementing the provisions of the energy and climate package...
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Effect of Coating Material Properties on Tilting-pad Thrust Bearing Performance
PublicationPolymer lined tilting-pad bearings demonstrate many advantages over traditional bearing systems. Bearings with a polymer layer in comparison with a babbitted layer show, for example: lower value of friction coefficient (important during start/stops), higher fatigue strength of the coating, better distribution of the load on individual pads due to lower elasticity of the polymers, wider range of operational temperatures or the ability...
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Recent developments in biological sample testing methods for the confirmation of gestational exposure to tobacco smoke anddrugs of abused
PublicationSubstance use is most prevalent in reproductive-aged people also by women during pregnancy. In national prevalence surveys among women aged 15 to 44 years, 10.8 % of women reported using alcohol during pregnancy, 17 % reported smoking during pregnancy, and 4.4 % reported abusing any illicit substances during pregnancy. Virtually all illegal drugs, such as heroin and cocaine, pose dangers to a pregnant woman. Legal substances, such...
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Predicting seismic response of SMRFs founded on different soil types using machine learning techniques
PublicationPredicting the Maximum Interstory Drift Ratio (M-IDR) of Steel Moment-Resisting Frames (SMRFs) is a useful tool for designers to approximately evaluate the vulnerability of SMRFs. This study aims to explore supervised Machine Learning (ML) algorithms to build a surrogate prediction model for SMRFs to reduce the need for complex modeling. For this purpose, twenty well-known ML algorithms implemented in Python software are trained...
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CPLFD-GDPT5: High-resolution gridded daily precipitation and temperature data set for two largest Polish river basins
PublicationThe CHASE-PL (Climate change impact assessment for selected sectors in Poland) Forcing Data–Gridded Daily Precipitation & Temperature Dataset–5 km (CPLFD-GDPT5) consists of 1951–2013 daily minimum and maximum air temperatures and precipitation totals interpolated onto a 5 km grid based on daily meteorological observations from the Institute of Meteorology and Water Management (IMGW-PIB; Polish stations), Deutscher Wetterdienst...