TY - JOUR A1 - Stadler, Dominik A1 - Hofmann, Matthias J. A1 - Motschmann, Hubert A1 - Shamonin (Chamonine), Mikhail T1 - Automotived system for measuring the surface dilational modulus of liquid-air interfaces JF - Measurement Science and Technology N2 - The surface dilational modulus is a crucial parameter for describing the rheological properties of aqueous surfactant solutions. These properties are important for many technological processes. The present paper describes a fully automated instrument based on the oscillating bubble technique. It works in the frequency range from 1 Hz to 500 Hz, where surfactant exchange dynamics governs the relaxation process. The originality of instrument design is the consistent combination of modern measurement technologies with advanced imaging and signal processing algorithms. Key steps on the way to reliable and precise measurements are the excitation of harmonic oscillation of the bubble, phase sensitive evaluation of the pressure response, adjustment and maintenance of the bubble shape to half sphere geometry for compensation of thermal drifts, contour tracing of the bubbles video images, removal of noise and artefacts within the image for improving the reliability of the measurement, and, in particular, a complex trigger scheme for the measurement of the oscillation amplitude, which may vary with frequency as a result of resonances. The corresponding automation and programming tasks are described in detail. Various programming strategies, such as the use of MATLAB® software and native C++ code are discussed. An advance in the measurement technique is demonstrated by a fully automated measurement. The instrument has the potential to mature into a standard technique in the fields of colloid and interface chemistry and provides a significant extension of the frequency range to established competing techniques and state-of-the-art devices based on the same measurement principle. KW - automated measurements KW - DILATATIONAL PROPERTIES KW - dilational modulus KW - graphical user interfaces KW - image processing KW - MEDIUM FREQUENCY-RANGE KW - OSCILLATING BUBBLE TECHNIQUE KW - RHEOLOGY KW - signal processing KW - STABILITY KW - surface rheology KW - TENSIOMETRY Y1 - 2016 U6 - https://doi.org/10.1088/0957-0233/27/6/065301 VL - 27 IS - 6 PB - IOP Science ER - TY - JOUR A1 - Stadler, Dominik A1 - Hofmann, Matthias J. A1 - Motschmann, Hubert A1 - Shamonin (Chamonine), Mikhail T1 - Automated system for measuring the surface dilational modulus of liquid-air interfaces JF - Measurement Science and Technology N2 - The surface dilational modulus is a crucial parameter for describing the rheological properties of aqueous surfactant solutions. These properties are important for many technological processes. The present paper describes a fully automated instrument based on the oscillating bubble technique. It works in the frequency range from 1 Hz to 500 Hz, where surfactant exchange dynamics governs the relaxation process. The originality of instrument design is the consistent combination of modern measurement technologies with advanced imaging and signal processing algorithms. Key steps on the way to reliable and precise measurements are the excitation of harmonic oscillation of the bubble, phase sensitive evaluation of the pressure response, adjustment and maintenance of the bubble shape to half sphere geometry for compensation of thermal drifts, contour tracing of the bubbles video images, removal of noise and artefacts within the image for improving the reliability of the measurement, and, in particular, a complex trigger scheme for the measurement of the oscillation amplitude, which may vary with frequency as a result of resonances. The corresponding automation and programming tasks are described in detail. Various programming strategies, such as the use of MATLAB (R) software and native C++ code are discussed. An advance in the measurement technique is demonstrated by a fully automated measurement. The instrument has the potential to mature into a standard technique in the fields of colloid and interface chemistry and provides a significant extension of the frequency range to established competing techniques and state-of-the-art devices based on the same measurement principle. KW - automated measurements KW - dilational modulus KW - graphical user interfaces KW - Image processing KW - oscillating bubble technique KW - signal processing KW - STABILITY KW - surface rheology Y1 - 2016 U6 - https://doi.org/10.1088/0957-0233/27/6/065301 VL - 27 IS - 6 PB - IOP PUBLISHING ER - TY - JOUR A1 - Burdin, Dmitrii A. A1 - Chashin, Dmitri V. A1 - Ekonomov, Nikolai A. A1 - Fetisov, Leonid Y. A1 - Fetisov, Yuri K. A1 - Shamonin (Chamonine), Mikhail T1 - DC magnetic field sensing based on the nonlinear magnetoelectric effect in magnetic heterostructures JF - Journal of physics D: Applied physics N2 - Recently, highly sensitive magnetic field sensors using the magnetoelectric effect in composite ferromagnetic-piezoelectric layered structures have been demonstrated. However, most of the proposed concepts are not useful for measuring dc magnetic fields, because the conductivity of piezoelectric layers results in a strong decline of the sensor's sensitivity at low frequencies. In this paper, a novel functional principle of magnetoelectric sensors for dc magnetic field measurements is described. The sensor employs the nonlinear effect of voltage harmonic generation in a composite magnetoelectric structure under the simultaneous influence of a strong imposed ac magnetic field and a weak dc magnetic field to be measured. This physical effect arises due to the nonlinear dependence of the magnetostriction in the ferromagnetic layer on the magnetic field. A sensor prototype comprising of a piezoelectric fibre transducer sandwiched between two layers of the amorphous ferromagnetic Metglas (R) alloy was fabricated. The specifications regarding the magnetic field range, frequency characteristics, and noise level were studied experimentally. The prototype showed the responsivity of 2.5 V mT(-1) and permitted the measurement of dc magnetic fields in the range of similar to 10 nT to about 0.4 mT. Although sensor operation is based on the nonlinear effect, the sensor response can be made linear with respect to the measured magnetic field in a broad dynamic range extending over 5 orders of magnitude. The underlying physics is explained through a simplified theory for the proposed sensor. The functionality, differences and advantages of the magnetoelectric sensor compare well with fluxgate magnetometers. The ways to enhance the sensor performance are considered. KW - composite KW - magnetic field sensors KW - magnetic heterostructures KW - magnetoelectric effect KW - nonlinear magnetostriction KW - Sensors KW - voltage harmonic generation Y1 - 2016 U6 - https://doi.org/10.1088/0022-3727/49/37/375002 VL - 49 IS - 37 PB - IOP Publishing ER - TY - JOUR A1 - Kalita, Viktor M. A1 - Snarskii, Andrei A. A1 - Zorinets, Denis A1 - Shamonin (Chamonine), Mikhail T1 - Single-particle mechanism of magnetostriction in magnetoactive elastomers JF - Physical Review E N2 - Magnetoactive elastomers (MAEs) are composite materials comprised of micrometer-sized ferromagnetic particles in a nonmagnetic elastomermatrix. Asingle-particle mechanism ofmagnetostriction in MAEs, assuming the rotation of a soft magnetic, mechanically rigid particle with uniaxial magnetic anisotropy in magnetic fields is identified and considered theoretically within the framework of an alternative model. In this mechanism, the total magnetic anisotropy energy of the filling particles in the matrix is the sum over single particles. Matrix displacements in the vicinity of the particle and the resulting direction of the magnetization vector are calculated. The effect of matrix deformation is pronounced well if the magnetic anisotropy coefficient K is much larger than the shear modulus mu of the elastic matrix. The feasibility of the proposed magnetostriction mechanism in soft magnetoactive elastomers and gels is elucidated. The magnetic-field-induced internal stresses in the matrix lead to effects of magnetodeformation and may increase the elastic moduli of these composite materials. KW - BEHAVIOR KW - Deformation KW - DEPENDENCE KW - FERROGELS KW - HOMOGENEOUS MAGNETIC-FIELD KW - magnetodeformation KW - MICROSTRUCTURE KW - SENSITIVE ELASTOMERS Y1 - 2016 U6 - https://doi.org/10.1103/PhysRevE.93.062503 VL - 93 IS - 6 PB - American Physical Society ER - TY - JOUR A1 - Kurzweil, Peter A1 - Shamonin (Chamonine), Mikhail A1 - Udalzow, Anton T1 - Selbstentladung und Leckstromverhalten elektrochemischer Speicher: Impedanzspektroskopie im Langzeitversuch JF - Forschungsbericht 2016 / OTH Amberg-Weiden N2 - Doppelschichtkondensatoren sind elektrochemische Speicher, die innerhalb von Mikrosekunden auf schnelle Laständerungen antworten. Auf der Basis einer mehr als zehnjährigen Testerfahrung unserer Arbeitsgruppe sind wir in der Lage, das Alterungsverhalten von Superkondensatoren anhand von Kapazitätsverlust, parasitären Nebenreaktionen und der chemischen Analyse von Alterungsprodukten zu quantifizieren. Weitgehend ungeklärt sind die elektrochemischen Mechanismen bei der Selbstentladung der Bauteile, die wir nun mithilfe der Impedanzspektroskopie näher untersucht haben . Double-layer capacitors are electrochemical storage devices that are able to respond to immediate load changes within some microseconds. Based on more than ten years testing experience of our work group, the aging behaviour of supercapacitors is quantified in terms of capacitance loss, parasitic side reactions, and the chemical analysis of decomposition products. So far, the electrochemical processes during self-discharge have been widely unknown. By the help of impedance spectroscopy, we investigated this item in more detail. Y1 - 2016 UR - https://www.oth-aw.de/files/oth-aw/Aktuelles/Veroeffentlichungen/Forschungsbericht/Forschungsbericht_2016.pdf SN - 2365-1997 SP - 90 EP - 94 PB - Ostbayerische Technische Hochschule Amberg-Weiden ER - TY - CHAP A1 - Shamonin (Chamonine), Mikhail A1 - Dechant, Eduard A1 - Fedulov, Feodor A1 - Fetisov, Leonid Y. T1 - Bandwidth optimization of piezoelectric cantilever beam arrays for harvesting energy from broadband, low-frequency mechanical vibrations T2 - INTERMATIC 2016, 21.–25.11.2016, Moskau Y1 - 2016 UR - https://elibrary.ru/item.asp?id=29382003 VL - 16 SP - 187 EP - 190 CY - Moskau ER - TY - JOUR A1 - Belyaeva, Inna A. A1 - Kramarenko, Elena Yu A1 - Stepanov, Gennady V. A1 - Sorokin, Vladislav V. A1 - Stadler, Dominik A1 - Shamonin (Chamonine), Mikhail T1 - Transient magnetorheological response of magnetoactive elastomers to step and pyramid excitations JF - SOFT MATTER N2 - Transient rheological response of magnetoactive elastomers is experimentally studied using dynamic torsion at a fixed oscillation frequency in temporally stepwise changing magnetic fields and oscillation amplitudes. For step magnetic-field excitations, at least three exponential functions are required to reasonably describe the time behavior of the storage shear modulus over long time scales (>10(3) s). The deduced characteristic time constants of the corresponding rearrangement processes of the filler network differ approximately by one order of magnitude: tau(1) less than or similar to 10(1) s, tau(2) similar to 10(2) s, and tau(3) similar to 10(3) s. The sudden imposition of the external magnetic field activates a very fast rearrangement process with the characteristic time under 10 s, which cannot be determined more precisely due to the measurement conditions. Even more peculiar transient behavior has been observed during pyramid excitations, when either the external magnetic field was first stepwise increased and then decreased in a staircase manner at a fixed strain amplitude gamma or the strain amplitude gamma was first stepwise increased and then decreased in a staircase manner at a fixed magnetic field. In particular, the so-called "cross-over effect'' has been identified in both dynamical loading programs. This cross-over effect seems to be promoted by the application of the external magnetic field. The experimental results are discussed in the context of the specific rearrangement of the magnetic filler network under the simultaneous action of the external magnetic field and shear deformation. Striking similarities of the observed phenomena to the structural relaxation processes in glassy materials and to the jamming transition of granular materials are pointed out. The obtained results are important for fundamental understanding of material behavior in magnetic fields as well as for the development of devices on the basis of magnetoactive elastomeric materials. KW - AMPLITUDE KW - BEHAVIOR KW - DEPENDENCE KW - FLUID KW - HOMOGENEOUS MAGNETIC-FIELD KW - NORMAL FORCE KW - OSCILLATORY SHEAR KW - TIME KW - VISCOELASTIC PROPERTIES Y1 - 2016 U6 - https://doi.org/10.1039/c5sm02690c VL - 12 IS - 11 SP - 2901 EP - 2913 PB - ROYAL SOC CHEMISTRY ER -