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Search results for: conductive hydrogels
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Electrical properties of Na2O-CaO-P2O5 glasses doped with SiO2 and Si3N4
PublicationSodium-calcium-phosphate glasses doped with SiO2 or Si3N4 having similar sodium ion concentrations were prepared by melt quenching. The conductivity was measured by impedance spectroscopy under nitrogen atmosphere in a wide frequency range (10 mHz–1 MHz) and wide temperature range (153–473 K). At 36.6 °C, DC conductivities of all glasses vary between 1.1 ∗ 10−12 and 8.9 ∗ 10−12 S cm−1 and have similar activation energies (between...
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A simplified energy dissipation based model of heat transfer for subcooled flow boiling
PublicationIn the paper a model is presented based on energetic considerations for subcooled flow boiling heat transfer. The model is the extension of authors own model developed earlier for saturated flow boiling and condensation. In the former version of the model we used the heat transfer coefficient for the liquid single-phase as a reference level, due to the lack of the appropriate model for heat transfer coefficient for the subcooled...
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Crystallographic study of self-organization in the solid state including quasi-aromatic pseudo-ring stacking interactions in 1-benzoyl-3-(3,4-dimethoxyphenyl)thiourea and 1-benzoyl-3-(2-hydroxypropyl)thiourea
Publication1-Benzoylthioureas contain both carbonyl and thiocarbonyl functional groups and are of interest for their biological activity, metal coordination ability and involvement in hydrogen-bond formation. Two novel 1-benzoylthiourea derivatives, namely 1-benzoyl-3-(3,4-dimethoxyphenyl)thiourea, C₁₆H₁₆N₂O₃S, (I), and 1-benzoyl-3-(2-hydroxypropyl)thiourea, C₁₁H₁₄N₂O₂S, (II), have been synthesized and characterized. Compound (I) crystallizes...
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Determination of moisture resistance of covered electrodes according to PN-EN ISO 14372
PublicationMoisture present in the electrode covering is one of the sources of diffusible hydrogen in welded joints. In order to study the diffusible hydrogen content in deposited metal, a stand for moisturizing covered electrodes, in accordance with the PN-EN ISO 14372 standard, was built. After the stand was completed, a test of moisturizing the electrodes was carried out and measurements of the diffusible hydrogen content in deposited...
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Jarosław Chojnacki prof. dr hab. inż.
PeopleBorn in 1961 in Bydgoszcz, professional education started at the Chemical Technical Highschool (I. Łukasiewicz). He graduated from the Faculty of Chemistry at the Gdańsk University of Technology in 1986, defending the work on ion-selective electrodes. Subsequent studies were related to organic and siliconorganic synthesis and, from 2002 year on, to crystallography. The doctoral thesis concerned the Silanotiolanes of coinage metals...
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Eco-Friendly Electromagnetic Interference Shielding Materials from Flexible Reduced Graphene Oxide Filled Polycaprolactone/Polyaniline Nanocomposites
PublicationHybrid nanocomposites have the unique ability of enhancing material properties due to the existing synergistic effect of the fillers. In this study, the authors report such an eco-friendly hybrid nanocomposite comprising of polyaniline and reduced graphene oxide in polycaprolactone. The conducting polyaniline improved the processability of polycaprolactone, and the final composites were prepared by incorporating graphene oxide...
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Subjective and Objective Quality Evaluation Study of BPL -PLC Wired Medium
PublicationThis paper presents results of research on the effectiveness of bi-directional voice transmission in a 6 kV mine cable network using BPL-PLC (Broadband over Power Line - Power Line Communication) technology. It concerns both emergency cable state (supply outage with cable shorted at both ends) and loaded with distorted current waveforms. The narrowband (0.5 MHz–15 MHz) and broadband (two different modes, frequency range of 3 MHz–7.5...
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FTIR spectra and IGC chromatograms for chemically reduced graphene oxide aerogels (rGOA)
Open Research DataThe effect of selected synthesis parameters on reduced graphene oxide aerogels properties was investigated using Fourier-transform infrared spectroscopy and dynamic adsorption method (Inverse Gas Chromatography, IGC). Samples were synthesized by sol-gel method by reduction induced self-assembly of graphene oxide. As a reductant l-ascorbic acid was used....
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Correlation between structural and electrical properties in highly porous (Y,Sr)(Ti,Nb)O3-delta SOFC anodes
PublicationIn order to find a relationship between structural and electrical properties, niobium and yttrium doped SrTiO3 ceramics were prepared via solid-state reaction. The samples were sintered in hydrogen and air conditions. The samples were also fabricated with a pore-former to obtain highly porous specimens. The electrical properties of Nb-doped SrTiO3 samples and yttrium and niobium co-doped SrTiO3 were compared. The comparable electrical...
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Group project (NT2-eng. sem.3) - 2023
e-Learning CoursesCourse for 2nd degree Students of Nanotechnology, sem. 3. The aim of the course is to prepare students for teamwork by implementing a project involving the analysis of the problem by the team, presenting a proposal to solve the problem, conducting research/tests and preparing a report.
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Photocatalysts for Solar Energy Conversion
PublicationPhotocatalytic oxidation over suspended solid photocatalysts (e.g., titanium dioxide) has been proposed as a sustainable process for treatment and purification of water and wastewater as well as the process for photoconversion of solar energy to hydrogen, methane, and other low hydrocarbons. Solar radiation could be used to drive heterogeneous electrochemical reactions at the surface of an optically active photocatalyst (e.g.,...
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Alternative methods for dark fermentation course analysis
PublicationDark fermentation course analysis is crucial, as complexed matrix of gaseous components may be formed and revealed during the process. The paper considers key issues related to the microbiological process in which complex organic substances are transformed into hydrogen. For the purposes of hydrogen generation, the application of wastewater mixed sludge pre-treated according to Faloye method (Faloye et al. in Int J Hydrog Energy...
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Aryl and N-arylamide carbon nanotubes for electrical coupling of laccase to electrodes in biofuel cells and biobatteries
PublicationSingle walled carbon nanotubes (SWCNTs) were equipped with aryl residues by chemical reactions. These insoluble materials were used to substitute classical soluble mediators, which help to transfer electrical charge between the conducting electrode and the redox active center of enzyme molecules. The effect of different aryl residues on the efficiency of the catalytic reduction of dioxygen in the presence of laccase was systematically...
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An Analysis of Elliptical-Rectangular Patch Structure on Multilayer Elliptic Cylinders
PublicationThe resonance frequency problem of an ellipticalrectangular patch mounted on multilayered dielectric coated elliptic conducting cylinder, is investigated in this paper. A fullwave analysis and a moment-method calculation are employed. The analysis is carried out considering the expansion of the field as a series of Mathieu functions. An additional theorem for Mathieu functions is utilized to investigate the non-confocal ellipse...
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Comparative study of flow condensation in conventional and small diameter tubes
PublicationFlow boiling and flow condensation are often regarded as two opposite or symetrical phenomena. Their description however with a single correlation has yet to be suggested.In the case of flow boiling in minichannels there is mostly encountered the annular flow structure, where the buble generetion is not present. Similar picture holds for the case of inside tube condensation, where annular flow structure predominates. In such case...
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Effect of power frequency on the stress state of disc actuator
PublicationThis paper presents the concept of determining the optimum frequency of coil supply in inductive-dynamic drive. As a criterion to obtain the sought frequency, the smallest value of reduced stress in the disc was assumed while maintaining the desired dynamics. The disc stress is determined on the basis of solution of vibrating thin plate equation. Magnetic pressure acting on the disc is obtained from a hybrid circumferentially-field...
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Computer-Aided Calculations of Earth Potential Rise in High Voltage Overhead Lines
PublicationHigh voltage overhead power lines with earth wires comprise towers made of conductive material. Some towers are in locations where people can be expected to be either for a long time or for a short time but very frequently. Evaluation of shock hazard near such towers requires calculation of line-to-earth short-circuit current, earth current and especially earth potential rise. Number of towers in high voltage power lines can exceed...
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Optical monitoring of electrochemical processes with ITO-based lossy-mode resonance optical fiber sensor applied as an electrode
PublicationIn this work we discuss the application of optical fiber sensors based on lossy-mode resonance (LMR) phenomenon for real-time optical monitoring of electrochemical processes. The sensors were obtained by a reactive high power impulse magnetron sputtering of indium tin oxide (ITO) on a 2.5 cm-long core of polymer-clad silica fibers. The LMR effect made monitoring of changes in optical properties of both ITO and its surrounding medium...
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Water uptake analysis of acceptor-doped lanthanum orthoniobates
PublicationIn this work, lanthanum orthoniobates doped with either antimony, calcium, or both have been synthesized and studied. The water uptake of the investigated materials has been analyzed by means of thermogravimetric studies. The results show the difference between the thermodynamics of hydration between the lanthanum orthoniobate system and other proton conducting ceramics. The relation between the water uptake and effective acceptor...
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The dimensions of national competitiveness: the empirical analysis based on The World Economic Forum’s data
PublicationThe aim of this research is to determine the minimum number of uncorrelated dimensions which can describe national competitiveness (NC). NC is thought of as the ability of a nation to provide a conducive environment for its firms to prosper. It is shown that the environment affects national productivity catalytically through the interactions with the production factors while itself remaining unchanged. Selected World Economic...
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Preparation and X-ray structures of selected aminium thiosulfates
PublicationVarious types of aminium thiosulfates (1–6), including hydrates and mixed salts, have been obtained by the reaction of ammonium thiosulfate with amines. Tertbutylamine, cyclo-hexylamine and 1,6-diaminohexane gave crystals of (t-BuNH3)2S2O3·H2O (1), (c-C6H11NH3)2S2O3 (3) and {(NH4)2(H3NC6H12NH3)(S2O3)2} (6), respectively, which were investigated by X-ray structural analysis. Extensive hydrogen bonding of the N-H…O and N-H…S type...
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Optimal Multivariable Control for Modified Z-source Based IPT
PublicationThis paper describes Z-source based inductive power transfer topologies control approaches. The goal of this work is a multi-variable control approach which involves a constant voltage/constant current control along with an optimal frequency control to obtain maximum efficiency. This control is applied to the wireless power transfer system based on a modified Z-source topology. The description of the control method along with simulation...
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Ewa Klugmann-Radziemska prof. dr hab.
PeopleEwa Klugmann-Radziemska graduated from the University of Gdansk with a degree in physics, and since 1996 has been associated with the Gdansk University of Technology, when she began PhD studies. Currently, he is a professor at the Faculty of Chemistry at the Gdansk University of Technology, since 2006 head of the Department of Chemical Apparatus and Machinery. In the years 2008–2016 she was the Vice-Dean for cooperation and development,...
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Zaawansowane utlenianie odcieków składowiskowych - przegląd metod
PublicationPrzedstawiono rozwiązania unieszkodliwiania odcieków składowiskowych metodami zaawansowanego utleniania, takimi jak: reakcja Fentona, utlenienie ozonem i nadtlenkiem wodoru, utlenienie elektrochemiczne, utlenienie w warunkach nadkrytycznych oraz mokre utlenienie powietrzem. Podstawy teoretyczne tych metod, ich efektywność oraz stosowane reagenty. Uwarunkowania stosowania poszczególnych metod.
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Patryk Ziółkowski dr inż.
PeoplePatryk Ziolkowski is a graduate of the Faculty of Civil and Environmental Engineering at the Gdansk University of Technology, specializing in Building and Engineering Structures. He works as an Assistant Professor at the Department of Engineering Structures. He participated in international projects, including projects for the Ministry of Transportation of the State of Alabama (2015), he is also the winner of a grant from the Kosciuszko...
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Spatial Modelling in Environmental Analysis and Civil Engineering
PublicationAs can be seen, Spatial Modelling in Environmental Analysis and Civil Engineering applies to a multitude of applications. In an attempt to bring the topic closer to potential readers, the special issue referred to security methods, optimization of calculations, conducting measurements and empirical tests. Each article has made an original contribution to the development of practical science that can be replicated by researchers...
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Effect of Nanohydroxyapatite on Silk Fibroin–Chitosan Interactions—Molecular Dynamics Study
PublicationFibroin–chitosan composites, especially those containing nanohydroxyapatite, show potential for bone tissue regeneration. The physicochemical properties of these biocomposites depend on the compatibility between their components. In this study, the intermolecular interactions of fibroin and chitosan were analyzed using a molecular dynamics approach. Two types of systems were investigated: one containing acetic acid and the other...
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Interactions of protons with furan molecules studied by collision-induced emission spectroscopy at the incident energy range of 50–1000 eV
PublicationInvestigations of the ion-molecule reactions provide insight into many fields ranging from the stellar wind interaction with interstellar media, up to medicine and industrial applications. Besides the applications, the understanding of these processes is itself a problem of fundamental importance. Thus, interactions of protons with the gas-phase furan molecules have been investigated for the first time in the energy range of 50–1000...
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Group project (NT2-eng. sem.3) - 2022
e-Learning CoursesCourse for 2nd degree Students of Nanotechnology, sem. 3, academic year 2022/2023. The aim of the course is to prepare students for teamwork by implementing a project involving the analysis of the problem by the team, presenting a proposal to solve the problem, conducting research/tests and preparing a report.
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Accurate modeling of layout parasitic to forecast EMI emitted from a DC-DC converter.
PublicationThis paper illustrates how to account for all parasitic due to the layout of a power converter (inductive and capacitive), in order to forecast electromagnetic interferences (EMI). The method is generic, and is validated here in the simple example of a DC-DC converter, realized on different technologies: insulated metal substrate (IMS), printed circuit board (PCB). In addition, several layouts aspects will be investigated. Conclusions...
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PROJECT IMPLEMENTATION IN ORGANISATIONS OF REPETITIVE ACTIVITIES
PublicationThe study presents the implementation of projects in organisations that achieve business objec-tives through the implementation of repetitive actions. Projects in these organisations are, on the one hand, treated as marginal activities, while the results of these projects have significant impact on the delivery of main processes, e.g. through the introduction of new products. Human capital and solutions in this field bear impact...
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Statistics of AFM current-voltage curves
Open Research DataMapping surface electrical conductivity offers enormous cognitive possibilities regarding the structure and properties of modern materials. The technique invented for this purpose (Conductive AFM) by Murrel's team and colleagues allows independent monitoring of the local conductivity of materials in correlation with the topographic profile. The mentioned...
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Corrosion and Cavitation Resistances of Low Alloy Steel After Frictional-Mechanical Treatment
PublicationPaper presents the results of the studies of wear, corrosion and cavitation resistances of the S355J2 low alloy medium carbon steel subjected to surface modification by friction-mechanical treatment, as tested in sea water simulated solution. To evaluate the effect of the surface treatment, the comparative studies of the corrosive properties of the steel before and after treatment have been considered. The treatment due to a severe...
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On the convergence of a finite-difference discretization à la Mickens of the generalized Burgers–Huxley equation
PublicationIn this note, we establish the property of convergence for a finite-difference discretization of a diffusive partial differential equation with generalized Burgers convective law and generalized Hodgkin–Huxley reaction. The numerical method was previously investigated in the literature and, amongst other features of interest, it is a fast and nonlinear technique that is capable of preserving positivity, boundedness and monotonicity....
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Mobile Laser Scanning Calibration on a Marine Platform
PublicationThe article describes the method of calibration of the Riegl VMZ-400 mobile scanning system on a floating platform and an experiment aimed at conducting measurements from a previously calibrated instrument. The issue of factors affecting the quality of measurements was discussed. Mobile laser scanning is an increasingly popular measurement solution, but it is still innovative on a European scale. The use of a floating platform...
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DWDM Network Laboratory Solution for Telecommunication Education Engineering
PublicationDevelopment of network architectures in the field of optical telecommunications technologies is an indicator of changes in telecommunication education engineering. Conducting didactic classes requires hardware infrastructure and research in terms of teaching needs. In the paper we present DWDM network laboratory solution for telecommunication education engineering on the basis of the ADVA Optical Networking equipment. We have to...
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Why is the cubic structure preferred in newly formed ice?
PublicationMolecular dynamics was employed to explain the preference for the cubic structure in newly formed crystals of ice. The results showed that in supercooled liquid water the molecules connected by hydrogen bonds are more likely to adopt relative orientations similar to the ones characteristic for cubic ice. The observed preference for certain relative orientations of molecules in the hydrogen-bonded pairs results in the higher probability...
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Thermally tuneable optical and electrochemical properties of Au-Cu nanomosaic formed over the host titanium dimples
PublicationAu-Cu nanostructures offer unique optical and catalytic properties unlike the monometallic ones resulting from the specific interaction. Among others, they have the ability to exhibit surface plasmon resonance, electrochemical activity towards the oxygen and hydrogen evolution reaction (OER, HER) as well as improved photoresponse in relation to monometalic but those properties depend highly on the substrate where bimetallic structures...
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Gas Composition Influence on the Properties of Boron-Doped Diamond Films Deposited on the Fused Silica
PublicationThe main subject of this study are molecular structures and optical properties of boron-doped diamond films with [B]/[C] ppm ratio between 1000 and 10 000, fabricated in two molar ratios of CH 4 -H 2 mixture (1 % and 4 %). Boron-doped diamond (BDD) film on the fused silica was presented as a conductive coating for optical and electronic purposes. The scanning electron microscopy images showed homogenous and polycrystalline surface...
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Towards truly sustainable IoT systems: the SUPERIOT project
PublicationThis paper provides an overview of the SUPERIOT project, an EU SNS JU (Smart Networks and Services Joint Undertaking) initiative focused on developing truly sustainable IoT systems. The SUPERIOT concept is based on a unique holistic approach to sustainability, proactively developing sustainable solutions considering the design, implementation, usage and disposal/reuse stages. The concept exploits radio and optical technologies...
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Analysis of Induced Voltages and Power Losses in High Voltage Power Cables for Selected Methods of Cables Sheaths Bonding
PublicationPower is increasingly supplied to city centres with 110 kV cable lines. This is a convenient way to supply power, and practically the only one possible in areas of dense urban development. A high-voltage cable contains a coaxial metallic sheath, in which in normal operation and in fault conditions (during short-circuits) significant line-to-earth voltages can be induced, which threatens electric shock and/or damage to the cable’s...
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Influence of alkali metal cations on the photoactivity of crystalline and exfoliated amorphous WO3 – photointercalation phenomenon
PublicationIn order to investigate the effect of photointercalation on photoelectrochemical properties, two types of WO3-based photoanodes, bulk and exfoliated have been prepared and investigated. An aqueous exfoliation method is introduced for the simple fabrication of amorphous and hydrated WO3 nanomaterial using commercial bulk WO3 precursor. The comparison of obtained material with bulk WO3 was performed using Raman, UV–vis, and XPS as...
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Biomedical engineering of polysaccharide-based tissue adhesives: Recent advances and future direction
PublicationTissue adhesives have been widely used for preventing wound leaks, sever bleeding, as well as for enhancing drug delivery and biosensing. However, only a few among suggested platforms cover the circumstances required for high-adhesion strength and biocompatibility, without toxicity. Antibacterial properties, controllable degradation, encapsulation capacity, detectability by image-guided procedures and affordable price are also...
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Non-Destructive Testing of the Longest Span Soil-Steel Bridge in Europe—Field Measurements and FEM Calculations
PublicationThe article describes interdisciplinary and comprehensive non-destructive diagnostic tests of final bridge inspection and acceptance proposed for a soil-steel bridge made of corrugated sheets, being the European span length record holder (25.74 m). As an effect of an original concept a detailed and precise information about the structure short-term response was collected. Periodic diagnostics of bridge deformations was done one...
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Self-assembly of secondary aryl amides in cocrystals with perfluoroaryl coformers: structural analysis and synthon preferences
PublicationCooperation of aryl⋯perfluoroaryl stacking interactions and hydrogen bonds was utilized in the construction of six novel cocrystals of aromatic cis-amides with pentafluorobenzoic acid (pfba) and pentafluorophenol (pfp). They were obtained by crystallization from solution and structurally characterized. In four instances, the components form heterotetrameric motifs, in which amide:amide homodimer interacts symmetrically on two sides...
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Entropy function application within the selection process of diagnostic parameters of marine diesel and gas turbine engines
PublicationThe paper presents the method of conducting an analysis of the diagnostic informativeness among the parameters characterizing the observed gas dynamic processes carried out within working spaces of marine diesel and gas turbine engines. An entropy function, as the measure of uncertainty of the identified states' set of the engine unfitness was applied. Having evaluated the diagnostic information the most adequate parameters were...
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Magnetism and charge density waves in RNiC2(R=Ce,Pr,Nd)
PublicationWe have compared the magnetic, transport, galvanomagnetic, and specific-heat properties of CeNiC2, PrNiC2, and NdNiC2 to study the interplay between charge density waves (CDW) and magnetism in these compounds. The negative magnetoresistance in NdNiC2 is discussed in terms of the partial destruction of charge density waves and an irreversible phase transition stabilized by the field-induced ferromagnetic transformation is reported....
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1,3-Di-<i>n</i>-butylthiourea
PublicationIn the title compound, C9H20N2S, the n-butyl groups are in syn and anti positions in relation to the C=S bond. In the crystal, two molecules are connected by two N-H···S=C hydrogen bonds into a centrosymmetric dimer. Another N-H···S=C hydrogen bond links the dimers, forming layers with a hydrophilic interior and a hydrophobic exterior, which spread across the (100) plane. Interlacing of the...
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Electronic conductivity in the SiO2-PbO-Fe2O3 glass containing magnetic nanostructures
PublicationThe linear impedance spectra of iron–silicate–lead glass samples were measured in the frequency range from 1 MHz to 1 MHz and in the temperature range from 153 K to 423 K. The structure was investigated by means of XRD and atomic force microscopy. Local electrical and magnetic properties of the samples were tested with the aid of electrostatic force microscopy (EFM) and magnetic force microscopy (MFM). The obtained results show...
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Study of the formation of calcareous deposits on cathodically protected steel in Baltic sea water
PublicationPurpose – The purpose of this paper is to investigate whether the sedimentation of calcareous deposits occurs on cathodically protected steel in Baltic sea water. Design/methodology/approach – Steel electrodes were cathodically polarized in natural Baltic sea water at potential þ0.150 V vs Zn electrode in potentiostatic mode. During exposure chronoamperometric measurements were carried out. After the exposure, the electrode’s surface...