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Search results for: FRACTOGRAPHY HYDROGEN DAMAGE PITTING SLOW STRAIN RATE TEST (SSRT) SUPERAUSTENITIC STAINLESS STEE
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Urchin-like TiO2 structures decorated with lanthanide-doped Bi2S3 quantum dots to boost hydrogen photogeneration performance
PublicationThe formation of heterojunctions between wide- and narrow-bandgap photocatalysts is commonly employed to boost the efficiency of photocatalytic hydrogen generation. Herein, the photoactivity of urchin-like rutile particles is increased by decorating with pristine as well as Er- or Yb-doped Bi2S3 quantum dots (QDs) at varied QD loadings (1–20 wt%) and doping degrees (1–15 mol%), and the best hydrogen evolution performance is achieved at...
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Maximizing Bio-Hydrogen and Energy Yields Obtained in a Self-Fermented Anaerobic Bioreactor by Screening of Different Sewage Sludge Pretreatment Methods
PublicationEgypt faces significant challenges in managing its sewage sludge generated in large quantities from wastewater treatment plants. This study investigates the feasibility of utilizing sewage sludge as a renewable resource for hydrogen production through anaerobic digestion at the 100 L bioreactor level. Hydrogen is considered a promising alternative energy source due to its high energy content and environmental benefits. To optimize...
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Independent dynamics of slow, intermediate, and fast intracranial EEG spectral activities during human memory formation
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Telemedicine methods for low bit rate communication
PublicationW pracy przedstawiono metody, które mogą być zastosowane w wybranych aspektach telemedycyny przy zredukowanym strumieniu danych. Przedstawiono i omówiono rozwiązania dla telekonsultacji przygotowanych (przygotowane dane, telekonsultacje w czasie rzeczywistym) oraz telekonsultacji w wypadkach nagłych.
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Forecasting of the Employment Rate in the EU ICT Field
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Real-time speech-rate modification experiments
PublicationAn algorithm designed for real-time speech time scale modification (stretching) is proposed, providing a combination of typical synchronous overlap and add based time scale modification algorithm and signal redundancy detection algorithms that allow to remove parts of the speech signal and replace them with the stretched speech signal fragments. Effectiveness of signal processing algorithms are examined experimentally together...
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Optimal edge-coloring with edge rate constraints
PublicationWe consider the problem of covering the edges of a graph by a sequence of matchings subject to the constraint that each edge e appears in at least a given fraction r(e) of the matchings. Although it can be determined in polynomial time whether such a sequence of matchings exists or not [Grötschel et al., Combinatorica (1981), 169–197], we show that several questions about the length of the sequence are computationally intractable....
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Comparison of strain results at a laser weld notch obtained by numerical calculations and experimental measurements
PublicationIn the development of ship structures applying new materials and it’s purposeful placement play an important role. During the last years, especially in a construction of ro-ro type vessels, the usage of novel sandwich structures in cargo decks is profitable. Steel sandwich panel is an innovative solution which at a todays state of development can be used for the construction of any members not taking part in a global bending of...
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Damage imaging algorithm for non-destructive inspection of CFRP/steel adhesive joints based on ultrasonic guided wave propagation
PublicationThe paper concerns assessing the quality of the adhesive connection between a steel plate and the reinforcing CFRP laminate. A three-stage algorithm for non-destructive damage imaging was developed. As the first step, an initial study involving dispersion curves of joint components was executed to determine the material parameters and the appropriate excitation frequency. During the second step, damage identification in three-layer...
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Hopping or Tunneling? Tailoring the Electron Transport Mechanisms through Hydrogen Bonding Geometry in the Boron-Doped Diamond Molecular Junctions
PublicationMechanisms of charge transport in molecular junctions involving hydrogen bonds are complex and remain mostly unclear. This study is focused on the elucidation of the electron transfer in a molecular device consisting of two boron-doped diamond interfaces bound with an aromatic linker and a hydrogen bonding surrogating molecule. The projected local density of states (PLODS) analysis coupled with transmission spectra and current−voltage...
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Nonlinear strain gradient and micromorphic one-dimensional elastic continua: Comparison through strong ellipticity conditions
PublicationWe discuss the strong ellipticity (SE) conditions for strain gradient and micromorphic continua considering them as an enhancement of a simple nonlinearly elastic material called in the following primary material. Recently both models are widely used for description of material behavior of beam-lattice metamaterials which may possess various types of material instabilities. We analyze how a possible loss of SE results in the behavior...
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The initial selection of parameters for dynamic brake for car engine test dynamometer
PublicationThe article presents an analysis of the car engine loads. The aim of the analysis was to determine the parameters of the brake / electric motor on an engine test bad. Analysis of loads on the driving tests concerned on chassis dynamo to simulate them on an engine dynamometer. To check the range of dynamometer shaft angular acceleration inertial mass of a car was reduced on the crankshaft axis. The calculations of maximum shaft...
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Implementation of Haar wavelet, higher order Haar wavelet, and differential quadrature methods on buckling response of strain gradient nonlocal beam embedded in an elastic medium
PublicationThe present investigation is focused on the buckling behavior of strain gradient nonlocal beam embedded in Winkler elastic foundation. The first-order strain gradient model has been combined with the Euler–Bernoulli beam theory to formulate the proposed model using Hamilton’s principle. Three numerically efficient methods, namely Haar wavelet method (HWM), higher order Haar wavelet method (HOHWM), and differential quadrature method...
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Monitoring Steel Bolted Joints during a Monotonic Tensile Test Using Linear and Nonlinear Lamb Wave Methods: A Feasibility Study
PublicationThe structural integrity of steel bolted joints may be compromised due to excessive loading. Therefore, condition assessment and the detection of potential defects before they cause a failure have become a major issue. The paper is focused on the condition monitoring of a bolted lap joint subjected to progressive degradation in a tensile test. The inspection used Lamb waves propagated through the overlap area. Wave propagation...
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The motion influence on respiration rate estimation from low-resolution thermal sequences during attention focusing tasks
PublicationGlobal aging has led to a growing expectancy for creating home-based platforms for indoor monitoring of elderly people. A motivation is to provide a non-intrusive technique, which does not require special activities of a patient but allows for remote monitoring of elderly people while assisting them with their daily activities. The goal of our study was to evaluate motion performed by a person focused on a specific task and check...
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Investigation on water infiltration and water content changes in a large-scale experimental test dike
PublicationThe paper presents result of series of experiments made within the DREDGDIKES project, performed on a test dike built from composite soil. The composite is produced by mixing fly ash (by-product of energetics) with dredged material (sand) taken from the mouth of The Vistula river. The test dike, located near Gdansk in Poland, was subjected to hydraulic load in several flooding time scenarios and the unsaturated unsteady flow was...
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A novel method of local chirp-rate estimation of LFM chirp signals in the time-frequency domain
PublicationIn the paper, novel dynamic representations of a complex signal in the time-frequency domain are introduced. The proposed approach is based on using the gradient of the short-time Fourier transform complex phase. A channelized instantaneous complex frequency (CICF) and a complex local group delay (CLGD) are included in the presented signal representations. An application of the newly-introduced distributions is demonstrated by...
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Experimental Study of Flow Rate in Hydraulic Satellite Motor with the Rotating Case at a Low Constant Rotational Speed
PublicationIn this article was described the methodology for the experimental study of flows in the prototype of a satellite hydraulic motor with a rotating body. The experimental tests of the motor were carried out at a low constant rotational speed in a wide range of pressure drop in this motor. The constant rotational speed of the motor was kept by a worm gear. Based on the test results, the leakage characteristics in the flat gaps of...
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Structure and thermoelectric properties of nickel-doped copper selenide synthesised in a hydrogen atmosphere
PublicationNickel-doped copper selenide—Cu2-xNixSe (x = 0; 0.01; 0.02; 0.03)—materials with high thermoelectric properties were synthesised through reduction of reagents in hydrogen. The impact of the nickel content on both the microstructure and thermoelectric properties was examined. The nickel-doped samples’ microstructure differed significantly from pristine copper selenide. Besides Cu2Se, copper precipitations were present in the materials....
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Heart Rate Asymmetry, Its Compensation, and Heart Rate Variability in Healthy Adults during 48-h Holter ECG Recordings
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Correlation between destruction of the metal surface caused by pitting corrosion and intensity of the observed electrochemical noise.
PublicationPrzedstawiono wyniki badań korelacji między intensywnością szumów elektrochemicznych obserwowanych podczas występowania procesów korozji wżerowej a zmianami obserwowanymi na powierzchni metalu.Badania przeprowadzono dla elektrod metalowych o powierzchni eksponowanej na środowisko korozyjne poniżej 1 mm2. Do wykrywania uszkodzeń powierzchni wykorzystano oprogramowanie MatLab, wykrywające uszkodzenia powierzchni metalu w formie okręgów...
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Low-Barrier Hydrogen Bond Determines Target-Binding Affinity and Specificity of the Antitubercular Drug Bedaquiline
PublicationThe role of short strong hydrogen bonds (SSHB) in ligand-target binding remains largely unexplored, thereby hin- dering a potentially important avenue in the rational drug de- sign. Here, we investigate the interaction between bedaquiline (Bq), a potent anti-tuberculosis drug, and the mycobacterial ATP synthase, to unravel the role of a specific hydrogen bond to a conserved acidic residue in the target affinity and specificity....
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Interplay between Aryl···Perfluoroaryl and Hydrogen Bonding Interactions in Cocrystals of Pentafluorophenol with Molecules of Trigonal Symmetry
PublicationCocrystals of seven star-shaped triaryl compounds with pentafluorophenol (pfp) were prepared and structurally characterized by the single-crystal X-ray diffraction method. Cocrystallization of pfp with planar (or almost planar) compounds gave six 3:1 molecular complexes with well-defined layered structures. The layers are composed of alternating pfp3 trimers, linked by hydrogen bonding, and triaryl molecules held together in planes...
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Evaluating Accuracy of Respiratory Rate Estimation from Super Resolved Thermal Imagery
PublicationNon-contact estimation of Respiratory Rate (RR) has revolutionized the process of establishing the measurement by surpassing some issues related to attaching sensors to a body, e.g. epidermal stripping, skin disruption and pain. In this study, we perform further experiments with image processing-based RR estimation by using various image enhancement algorithms. Specifically, we employ Super Resolution (SR) Deep Learning (DL) network...
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Sintering Parameter Investigation for Bimetallic Stainless Steel 316L/Inconel 718 Composite Printed by Dual-Nozzle Fused Deposition Modeling
PublicationFused deposition modeling (FDM) nowadays offers promising future applications for fabricating not only thermoplastic-based polymers but also composite PLA/Metal alloy materials, this capability bridges the need for metallic components in complex manufacturing processes. The research is to explore the manufacturability of multi-metal parts by printing green bodies of PLA/multi-metal objects, carrying these objects to the debinding...
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Opinion about causes of framing of Kingston chest (box cooler) damage, on PSV vessel VS4411 DF-PSV (B-855)
PublicationThe subject of analysis is a damage of welded connection of box cooler framing segments, made as separate bars 50mm thickness, connected by the welds in corners. Studies of documents delivered by Customer shows cracks on the fusion of filet welds and twisting of box cooler frame. The subject of analysis is a damage of welded connection of box cooler framing segments, made as separate bars 50mm thickness, connected by the welds...
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Experimental investigations on the mechanical properties and damage detection of carbon nanotubes modified crumb rubber concrete
PublicationThis study presents a modified crumb rubber (MCR) concrete design mix reinforced with multi-walled carbon nanotubes (MWCNTs), mechanical characterization, and cracking monitoring using the acoustic emission (AE) technique. The results showed that the bridging effect of MWCNTs and MCR in the concrete mix mitigated the shortcomings of MWCNT-MCR concrete and improved the flexural and compressive strengths by 18.3% and 26.5%, respectively,...
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Application of probabilistic tools to extend load test design of bridges prior to opening
PublicationLoad tests of bridges are widely performed in a large number of countries. Deterministic comparison of measurement results to the theoretical, FEM (finite element method)-based outcomes with possible further calibration is mostly applied. Sometimes, the data collected in the tests are also used to calibrate the reliability factors of bridge structures or their components. This work proposes to complement the stage of the load test...
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Photoplethysmographic Time-Domain Heart Rate Measurement Algorithm for Resource-Constrained Wearable Devices and its Implementation
PublicationThis paper presents an algorithm for the measurement of the human heart rate, using photoplethysmography (PPG), i.e., the detection of the light at the skin surface. The signal from the PPG sensor is processed in time-domain; the peaks in the preprocessed and conditioned PPG waveform are detected by using a peak detection algorithm to find the heart rate in real time. Apart from the PPG sensor, the accelerometer is also used to...
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Finite element modelling of a historic church structure in the context of a masonry damage analysis
PublicationThe paper includes a case study of modelling a real historic church using the finite element method (FEM) based on laser scans of its geometry. The main goal of the study was the analysis of the causes of cracking and crushing of masonry walls. An FEM model of the structure has been defined in ABAQUS. A non-linear dynamic explicit analysis with material model including damage plasticity has been performed. A homogenization procedure...
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Damage Analysis of Tensioning Cable Anchorage Zone of a Bridge Superstructure, Using CDP Abaqus Material Model
PublicationNumerical analysis of the tensioning cables anchorage zone of a bridge superstructure is presented in this paper. It aims to identify why severe concrete cracking occurs during the tensioning process in the vicinity of anchor heads. In order to simulate the tensioning, among others, a so-called local numerical model of a section of the bridge superstructure was created in the Abaqus Finite Element Method (FEM) environment. The...
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Experimental-Numerical Analysis of the Effect of Bar Diameter on Bond in Pull-Out Test
PublicationBar diameter is one of the basic factors affecting bond behavior, which is still of interest due to opposing opinions regarding its effect on bond behavior in the pull-out test. This paper presents an experimental and numerical bond analysis of ribbed reinforcing bar in concrete. The aim was to experimentally evaluate the effect of bar diameter on the bond behavior in the pull-out test and to perform numerical simulations of the...
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The role of low-energy electrons in the charging process of LISA test masses
PublicationThe estimate of the total electron yield is fundamental for our understanding of the test-mass charging associated with cosmic rays in the Laser Interferometer Space Antenna (LISA) Pathfinder mission and in the forthcoming gravitational wave observatory LISA. To unveil the role of low energy electrons in this process owing to galactic and solar energetic particle events, in this work we study the interaction of keV and sub-keV...
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The effect of numerical 2D and 3D FEM element modelling on strain and stress distributions at laser weld notches in steel sandwich type panels
PublicationLike other means of transport, merchant ships face the problem of increasing requirements concerning the environment protection, which, among other issues, implies the reduction of fuel consumption by the ship. Here, the conventional approach which consists in making use of higher strength steels to decrease the mass of the ship hull can be complemented by the use of new steel structures of sandwich panel type. However, the lack...
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Interactions between Marek’s disease virus Rispens/CVI988 vaccine strain and adenovirus field strain in chicken embryo fibroblast (CEF) cultures
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Computer aided materials design of PM duplex stainless steels
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Effect of microstructure on impact toughness of duplex and superduplex stainless steels
PublicationW artykule przedstawiono wpływ wyżarzania stali dupleks 2205 i superdupleks 2507 na przemiany strukturalne oraz udarność. Obróbkę cieplną przeprowadzono w zakresie temperatur 500-900C i w czasie 6 - 600 min. Określono i porównano podatność obu stali do zmian właściwości po wyżarzaniu
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Mechanical properties and corrosion resistance of dissimilar stainless steel welds
PublicationW artykule przedstawiono właściwości mechaniczne oraz odporność korozyjną doczołowych złączy różnoimiennych stali odpornych na korozję, austenitycznej 316L oraz duplex 2205. Blachy o grubości 15 mm spawano automatycznie łukiem krytyn z różnymi energiami liniowymi. Wykazano, że właściwości mechaniczne złączy spełniają wymagania okrętowych towarzystw klasyfikacyjnych, natomiast najbardziej narażoną strefą złącza na działanie korozji...
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The Use of Direct Shear Test for Optimization of Interlayer Bonding Under a Poroelastic Layer
PublicationPoroelastic Road Surfaces (PERS) are characterised by porous structure with air void content of 20% or higher and stiffness almost 10 times lower than that of a standard asphalt course. Such properties enable noise reduction by up to 12 dB in comparison to SMA 11 mixture. However, the disadvantage of a poroelastic pavement is its low durability, which partially results from delamination from the lower layer. The paper aims to investigate...
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Analog fault signature based on sigma-delta modulation and oscillation-test methodology.
PublicationW artykule dokonano przeglądu prac z zakresu testowania układów elektronicznych metodą oscylacyjną. Wskazując na niedostatki aktualnie stosowanej techniki testowania oscylacyjnego zaproponowano nową sygnaturę uszkodzeń dla układów analogowych. Proponowany parametr diagnostyczny jest wydobywany z odpowiedzi czasowej oscylatora testującego, w układzie złożonym z detektora szczytowego, modulatora sigma-delta oraz licznika rewersyjnego....
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Nickel-based catalysts for electrolytic decomposition of ammonia towards hydrogen production
PublicationNickel is an attractive metal for electrochemical applications because it is abundant, cheap, chemically resilient, and catalytically active towards many reactions. Nickel-based materials (metallic nickel, its alloys, oxides, hydroxides, and composites) have been also considered as promising electrocatalysts for ammonia oxidation. The electrolysis of ammonia aqueous solution results in evolution of gaseous hydrogen and nitrogen....
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Hydrogen migration observed in fragmentation of the pyridine molecules in collisions with the H+, H2+, He+and He++cations
PublicationThe hydrogen atom migration preceding fragmentation of the pyridine molecules by the H+, H2+, He+ and He++ collisions has been investigated in the 5-2000 eV energy range. The pyridine molecule structure is lacking of the NH group, thus formation of the NH radicals is an evidence of the H atom relocation prior to the cation-induced fragmentation. The NH(A3Π) fragmentation yields measured by detecting its A3Π→X3Σ− fluorescence show...
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Low-energy electron scattering from molecular hydrogen: Excitation of the X1Σg+ to b3Σu+ transition
PublicationWe present time-of-flight differential cross-section measurements and convergent close-coupling calculations of differential cross sections for the electron-impact excitation of the X 1 g + → b 3 u + transition in molecular hydrogen. A part of this work was recently published [M. Zawadzki et al., Phys. Rev. A 97, 050702(R) (2018)]. In this work, agreement between theory and experiment is excellent overall, and marks a transition...
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Data set generation at novel test-rig for validation of numerical models for modeling granular flows
PublicationSignificant effort has been exerted on developing fast and reliable numerical models for modeling particulate flow; this is challenging owing to the complexity of such flows. To achieve this, reliable and high-quality experimental data are required for model development and validation. This study presents the design of a novel test-rig that allows the visualization and measurement of particle flow patterns during the collision...
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Hydrogen migration in photodissociation of the pyridine molecules
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Methods for the characterizing hydrogen degradation of materials
PublicationDokonano przeglądu różnych metod szacowania podatności na niszczenie wodorowe materiałów metalowych. Zaprezentowano charakterystyki warunków środowiskowych: standardowe składy środowisk ciekłych i gazowych, temperatury, warunki polaryzacji elektrochemicznej. Omówiono metody mechaniczne szacowania niszczenia wodorowego różniące się stanem naprężeń, w tym badania: przy stałym obciążeniu, stałym odkształceniu i stałej niskiej szybkości...
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Hydrogen generation using solar energy
PublicationWodór jest uważany za alternatywne i odnawialne źródło energii. Bezpośrednie wykorzystanie światła słonecznego do fotokatalitycznego lub fotoelektrochemicznego rozkładu wody może zapewnić w przyszłości ekonomicznie uzasadnione, alternatywne źródło wodoru. W pierwszym etapie naszych badań został zaprojektowany i zbudowany hybrydowy, fotowoltaiczno-elektrochemiczny układ, dokonujący konwersji energii promieniowania słonecznego na...
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Hydrogen generation using solar energy
PublicationWodór jest uważany za alternatywne i odnawialne źródło energii. Bezpośrednie wykorzystanie światła słonecznego do fotokatalitycznego lub fotoelektrochemicznego rozkładu wody może zapewnić w przyszłości ekonomicznie uzasadnione, alternatywne źródło wodoru. W wystąpieniu przedstawione zostały wyniki dotychczasowych prac związanych z hybrydową, fotowoltaiczno-elektrochemiczną instalacją do rozkładu wody oraz omówione zostały kierunki...
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Aluminum-TiO2 NPs Composites as Non-precious Catalysts for Efficient Electrochemical Generation of Hydrogen
PublicationIn this paper, we demonstrated, for the first time, aluminum titania nanoparticle (Al-TiO2 NP) composites with variable amounts of TiO2 NPs as nonprecious active catalysts for the electrochemical generation of H2. These materials were synthesized by mixing desired amounts of hydrogen titanate nanotubes (TNTs), fabricated here by a cost-effective approach at moderate hydrothermal conditions, with aluminum powder (purity 99.7%; size...
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Long-term effects of device-guided slow breathing in stable heart failure patients with reduced ejection fraction
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