bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of welds by the method of the magneto-optical eddy current flaw detection
Authors: Lugovskoy Nazar , Berzhansky Vladimir , Filippov Dmitry , Prokopov Anatoliy , Shuyskyy Alexandr
Published: July 2018

The paper deals with the magneto-optical eddy current method of flaw detection of conducting materials, in which epitaxial films of ferrite garnet are used as sensors. In particular, the possibilities of visualization of welded seams in magnetic and non-magnetic samples, as well as the defectoscopy of the seams themselves, are considered. The second part of the work is devoted to mathematical modeling of the distribution of the magnetic fields of eddy currents near similar defects.
Hypersound excitation of magnetization and elastic displacement in case of magnetization reversal
Authors: Asadullin Fanur , Pleshev Dmitriy , Vlasov Vladimir , Kotov Leonid , Poleshchikov Sergey , Shavrov Vladimir , Shcheglov Vladimir
Published: July 2018

The paper gives a description of hypersound magnetoelastic oscillations excitation along magnetisation reversal of normal magnetized single-layer and multi-layers ferrite plates, also provides definition of distinctive features of magnetic and elastic oscillations development. The relation of oscillations to the parameters of saturation magnetization, magnetic and elastic damping has been revealed.
Frequency dependence of microwave complex permeability under magnetic bias
Authors: Shiryaev Artem O. , Bobrovskii Stanislav Y. , Osipov Aleksey V. , Petrov Dmitry A. , Rozanov Konstantin N. , Starostenko Sergey N.
Published: July 2018

Measurement of the frequency dependence of the permeability under magnetic bias is proposed as a new method for studying the microwave magnetic properties of magnetic materials. The samples under study are either rolls of thin ferromagnetic films or the composites filled with sendust particles. It is shown that the permeability measured under external magnetic bias depends on sample thickness. The correct interpretation of the measured data is possible only when sample demagnetization is accounted for. The values of the anisotropy field and the saturation magnetization of thin nitrogen doped iron films and flake-shaped sendust particles are calculated considering demagnetization of the washer-shaped sample.
Atomic ordering and coercive force of nanocrystalline Fe-Co alloy films
Authors: Repina Nataliya
Published: July 2018

In single crystal films of the Fe0,5Co0,5 alloys grown by the method of vacuum condensation, a metastable condition may be received that is similar to the completely disordering condition. Approximately during ten days after the condensation in the film at the room temperature the short range and then long range atomic ordering is developed. Simultaneously the changes of magnetic anisotropy, electroresistance and coercive force of the films were investigated. This investigations show that the appearance of the shot range atomic ordering increases the electroresistance of films and the long range atomic ordering reduces it. The dependence of coercive force from time to time at room temperature atomic ordering films Fe0,5Co0,5 alloys, and Fe0,75Co0,25. Found that the biggest change Hc (double) is observed in single-crystal films when changing mechanism of magnetization reverse. Most is a consequence of the changes to the crystallographic anisotropy.
Interaction of magnetic elements in metallic ferromagnetic nanofilms
Authors: P Panaetov V.
Published: July 2018

In this paper, a comparative analysis of the distances between magnetic elements is made, under which a noticeable effect arises when they interact. The sides of the domain (domain walls), the terminal part of the domain (domain apex), we called magnetic elements. During magnetization, the domain structure is restructured. The distances between the domain walls, between the domain wall and domain apex, between the apexes of the domains change. A metallic ferromagnetic nanofilm can be a medium for recording information with the help of magnetic moments of electrons. Interaction of domain walls, the interaction of the domain wall and the domain apex, the interaction of the domain apexes in the design of storage devices must be taken into account.
Magnetic properties of Tm2Fe16 under pressure
Authors: Kuchin Anatoly , Arnold Zdenek , Kamarád Jiri , Platonov Sergey
Published: July 2018

The magnetic properties of the non-stoichiometric Tm2Fe16 compound under hydrostatic pressures up to 1 GPa were studied. We have revealed that the high-temperature ferrimagnetic state easily magnetized in the basal plane is very sensitive to the volume changes and even moderate pressure is sufficient to its complete suppression and transformation to a helimagnetic state. At the same time, the low-temperature ferrimagnetic state easily magnetized along the hexagonal axis does not disappear under pressure and the temperature of its transition to the high-temperature magnetic states increases under pressure. The remarkable stability of the ground ferrimagnetic state under external pressure can be attributed to the strengthening of the uniaxial magnetic anisotropy and to the mutual perpendicular orientation of the magnetic moments in the ground and the high-temperature magnetic states.
Effect of aging on the magnetic properties of rapidly quenched Nd-rich Nd-Fe alloys
Authors: Wiafe-Akenteng Dennis , Menushenkov Vladimir , Shchetinin Igor , Savchenko Alexander
Published: July 2018

The FexNd100-x (x = 14, 28) alloys were successfully prepared by melt-spinning. Hysteretic and thermomagnetic properties of the as-melt-spun alloys and short-aged ribbons were investigated. Both ribbons exhibit a soft magnetic behavior at room temperature but at 5 K, the coercive force (Hci) proliferated to 8.6 kOe and 11.7 kOe, respectively. Thermomagnetic measurements, Zero Field Cooling (ZFC) and Field Cooling (FC), demonstrated that the rise in magnetization of the ribbons at temperatures lower 34 K is associated with ferromagnetism of fcc Nd-Fe solid solution clusters. Positive effect of aging on the coercivity of the Fe14Nd86 and Fe28Nd72 ribbons was observed. At 300 K, Hci of the ribbons upsurge to 2 - 2.8 kOe after aging at 400 - 450°C for 15 minutes but sharply diminished after aging at temperatures higher than 500°C. It was suggested that the increase in RT coercivity during aging was as a result of the decomposition of the amorphous phase and formation of the hard magnetic Fe-rich clusters. For both ribbons aged at 500°C, the magnetic transition at 340 K was observed to be in relation to the TC of the Nd2Fe17 compound. The appearance of this soft magnetic phase in the microstructure of the aged ribbons was linked with the drastic diminution of the coercivity at that temperature.
Stress Effects on Magnetic Properties of Amorphous Microwires Subjected to Current Annealing
Authors: Nematov Makhsudsho G. , Yudanov Nicolay A. , Yakubtsev Rodion A. , Panina Larissa V. , Beklemisheva Anna V. , Morchenko Alexander T. , Atul Thakur
Published: July 2018

Effects of current annealing on magnetic hysteresis properties and magnetoimpedance (MI) of glass-coated amorphous microwires with nominal composition of Co71Fe5B11Si10Cr3 and small positive magnetostriction were investigated with the purpose to control the magnetic anisotropy. We have demonstrated that current annealing can produce a controllable change in the easy anisotropy direction from almost axial to circular, depending on the annealing time. The induced magnetization configuration is very sensitive to the applied tensile stress. The combination of positive magnetostriction and helical anisotropy makes it possible to realise large stress-magnetoimpedance (S-MI) effect without use of any dc bias fields owing to the directional change in magnetization. This is especially important for microwave frequency S-MI effect and can be very interesting for developing stress-sensors operating at the high frequency region.
Investigation of magnetic phase transition and magnetocaloric effect of (Ni,Co)-Mn-Al melt-spun ribbons
Authors: Nguyen Yen , Nguyen Mai , Vu Quang , Pham Thanh , Koledov Victor , Kamantsev Alexander , Mashirov Alexey , Tran Thanh , Kieu Hau , Seong Yu , Nguyen Dan
Published: July 2018

Magnetic phase transition, magnetocaloric effect and critical parameters of Ni50-xCoxMn50-yAly (x = 5 and 10; y = 17, 18 and 19) rapidly quenched ribbons have been studied. X-ray diffraction patterns exhibit a coexistence of the L21 and 10M crystalline phases of the ribbons. Magnetization measurements show that all the samples behave as soft magnetic materials with a low coercive force less than 60 Oe. The shape of thermomagnetization curves considerably depends on Co and Al concentrations. The Curie temperature (TC) of the alloy ribbons strongly increases with increasing the Co concentration and slightly decreases with increasing the Al concentration. The Ni45Co5Mn31Al19 and Ni40Co10Mn33Al17 ribbons reveal both the positive and negative magnetocaloric effects. Under magnetic field change (ΔGH) of 13.5 kOe, the maximum magnetic entropy change (|ΔSm|max) of the Ni45Co5Mn31Al19 ribbon is about 2 and -1 J·kg−1·K−1 for negative and positive magnetocaloric effects, respectively. Basing on Arrott - Noakes and Kouvel - Fisher methods, critical parameters of the Ni45Co5Mn31Al19 ribbon were determined to be TC ≈ 290 K, β ≈ 0.58, γ ≈ 0.92 and δ ≈ 2.59. The obtained values of the critical exponents indicate that the magnetic order of the alloy ribbon is close to the mean-field model.
Phase formation and magnetocaloric effect in (Pr,Nd)-Fe alloys prepared by rapidly quenched method
Authors: Nguyen Dan , Nguyen Ha , Nguyen An , Nguyen Yen , Pham Thanh , Koledov Victor , Kamantsev Alexander , Mashirov Alexey , Tran Thanh , Kieu Hau , Yu Seong
Published: July 2018

In this work, Pr2-xNdxFe17 (x = 0 - 2) ribbons with thickness of about 15 μm were prepared by melt-spinning method. The alloy ribbons were then annealed at different temperatures (900 - 1100°C) for various time (0.25 - 2 h). The formation of the (Pr,Nd)2Fe17 (2:17) crystalline phase in the alloys strongly depends on the Pr/Nd ratio and annealing conditions. Annealing time for the completed formation of the 2:17 phase in the rapidly quenched ribbons is greatly reduced in comparison with that of bulk alloys. Curie temperature, TC, of the alloys can be controlled in room temperature region by changing Pr/Nd ratio. Maximum magnetic entropy change (|ΔSm|max) and full width at haft the maximum peak (FWHM) of the magnetic entropy change of the alloys were respectively found to be larger than 1.5 J.kg−1K−1 and 40 K in room temperature region with magetic field change ΔH = 12 kOe.
Double magnetocaloric peak feature observed in quaternary Ni-Mn-In based Heusler alloys
Authors: Rodionov I. D. , Dubenko I. S. , Prudnikov V. N. , Granovsky A. B. , Titov I. S. , Saletsky A. M.
Published: July 2018

We present the results of the studies of magnetic and magnetocaloric (MCE) properties of quaternary Heusler alloys Ni48.5Mn35In15Co1.5 and Ni50Mn35In13.5Al1.5 in temperature range between 80 K and 400 K. While doping initial ternary Ni-Mn-In alloy with 1.5 at.% Al does not change TCA as well as MS, doping with 1.5 at.% Co significantly increases both TCA and MS. The direct magnetocaloric measurements around martensitic transition and austenite Curie temperature reveal the competition between the contributions of different signs. The latter is related to the vicinity of transition temperatures of austenite and martensite, resulting in mixed state, where both phases undergo magnetic order-disorder transformation in the same temperature region. Additionally temperature dependencies of adiabatic temperature change ΔTad and magnetic entropy ΔSM of the system exhibit additional peak feature which we attribute to intermartensitic transition occurring in these alloys.
Shubnikov-de Haas oscillations in diluted magnetic semiconductors (Cd1-x-yZnxMny)3As2
Authors: Zakhvalinskii Vasilii S. , Nikulicheva Tatyana B. , Lähderanta Erkki , Kochura Aleksey V. , Nikitovskaia Ekaterina A. , Pilyk Evgeny A. , Pogrebneak Mikhail A.
Published: July 2018

Single crystals of a diluted magnetic semiconductor (Cd1-x-yZnxMny)3As2(CZMA) (x+y= 0.4;y=0.04 and 0.08) obtained by Bridgman method were used. The Shubnikov-de Haas (SdH) effect was observed within studying of the dependence of the resistivity on the magnetic field in CZMA solid solutions. The values of the cyclotron massmc, Hall and Shubnikov carrier concentrations were calculated.
Magnetotransport properties of InSb-MnSb nanostructured films
Authors: Kochura Aleksey , Marenkin Sergey , Novodvorsky Oleg , Mikhalevsky Vladimir , Davidov Alexander , Shakhov Mikhail , Lahderanta Erkki , Zakhvalinskii Vasilii , Kuzmenko Alexander
Published: July 2018

Hybrid nanostructured InSb - MnSb films were obtained by the pulsed laser deposition using the mechanical droplet separation. Films structure was characterized by different methods (electron diffraction, scanning electron microscopy, atomic and magnetic force microscopy). The negative magnetoresistance (nMR) takes place below 100 K. This temperature is several times more than the temperature at which the nMR occurs in homogenous In1-xMnxSb films. At low temperatures the spin-dependent scattering of the holes by the localized Mn2+ moments prevails. When the temperature rises, the low nMR is observed due to the weak spin-dependent scattering on magnetic inclusions.
Effect of oxygen nonstoichiometry on magnetic phase transitions in frustrated cobaltites YBaCo4O7+x (x = 0, 0.1, 0.2)
Authors: Kazei Zoya , Snegirev Vyacheslav , Kozeeva Ludmila , Kameneva Margarita , Lavrov Alexander
Published: July 2018

Experimental studies were carried out for structural and elastic properties of cobaltites YBaCo4O7+x (x = 0, 0.1, 0.2) obtained by various technologies and distinguished by oxygen content. Correlation was revealed between the structure distortion at room temperature and a hysteresis in a ΔE(T)/T0 curve in the temperature range 80 – 280 K, as well as the anomaly value in the region of TN. It was found, that small deviations from stoichiometry (x = 0.1, 0.2) result in suppression of structural transition, reduce a hysteresis, quickly smooth out and reduce anomalies of the Young’s modulus ΔE(T)/T0 in the range of magnetic phase transition. This behavior indicates that structural and magnetic transitions are suppressed in nonstoichiometric samples and only short range correlations of order parameters are retained
Influence of Magnetic Order Parameter Symmetry and Spin Fluctuations on Forming of Ferroelectric Order in Mn2O5 Oxides
Authors: Men`shenin Vladimir
Published: July 2018

The magnetic phase transitions from paramagnetic to magnetic phases have studied in RMn2O5 oxides. Using a symmetry analysis and renormalization group method it was shown that an appearance of the electric polarization or lack whereof in the magnetic phases are determined the symmetry of these phases and spin fluctuations in the vicinity of the phase transitions.
MFM Study of the Domain Structure of Permalloy Microparticles under Mechanical Stress
Authors: Biziyaev Dmitry , Bukharaev Anastas , Nurgazizov Niyaz
Published: July 2018

The domain structure of planar permalloy (Py) microparticles was studied under mechanical stress. An array of Py particles was formed by electron beam evaporation of Py on flat and preliminarily bent glass substrates. After evaporation the substrate was unbent and the Py particles were compressed along one axis. The change of the domain structure of stressed particles in comparison with that of unstressed particles was studied. It was shown that the change of the domain structure of Py particles depends on their compression ratio.
Isolation of proximity-induced triplet pairing channel in a superconductor/ferromagnet spin valve
Authors: Kamashev Andrey , Validov Aidar , Garif’yanov Nadir , Fominov Yakov , Leksin Pavel , Schumann Joachim , Thomas Jürgen , Kataev Vladislav , Büchner Bernd , Garifullin Ilgiz
Published: July 2018

In the present work we have studied the proximity-induced superconducting triplet pairing in CoOx/Py1/Cu/Py2/Cu/Pb spin-valve structure (where Py = Ni0:81Fe0:19). For CoOx(3 nm)/Py(3 nm)/Cu(4 nm)/Py(0.6 nm)/Cu(2 nm)/Pb(70 nm) we have studied the dependence of the Tc on the angle α between the direction of the cooling field and the external field both applied in the plane of the sample. We obtained that the Tc does not change monotonically with the angle but passes through a minimum. To observe an “isolated” triplet spin-valve effect we exploited the oscillatory feature of the magnitude of the ordinary spin-valve effect ΔTc in the dependence of the Py2-layer thickness dPy2. We determined the value of dPy2 at which ΔTc caused by the ordinary spin-valve effect is suppressed. This means that the difference in the Tc between the antiparallel and parallel mutual orientation of magnetizations of the Py1 and Py2 layers is zero. For such a sample a “pure” triplet spin-valve effect which causes the minimum in Tc at the orthogonal configuration of magnetizations has been observed.
Inhomogeneity and irreversibility field of superconducting Nb-Ti tapes
Authors: Guryev Valentin , Shavkin Sergey , Kruglov Vitaly
Published: July 2018

Magnetizations and current-voltage characteristics of superconducting tapes from Nb-50% wt.Ti alloy are studied. In the region of external magnetic fields close to the upper critical field, there is a so called irreversibility field, which is often associated with the phase transition of vortex matter. However, in this study it is shown that the whole volume of experimental data can be described if we abandon the hypothesis of a phase transition and go over to the hypothesis of macroscopic inhomogeneity. This hypothesis implies the existence of two superconducting components with different upper critical fields, which naturally arise as a result of the production process.
Features of microstructure and magnetic flux dynamics in superconducting Nb-Ti tapes with strong anisotropic pinning
Authors: Shavkin Sergey , Guryev Valentin , Kruglov Vitaly , Ovcharov Alexey , Likhachev Igor , Vasiliev Alexandre , Veligzhanin Alexey , Zubavichus Yan
Published: July 2018

Results of micro-structural, phase and texture analysis of Nb-Ti tapes and results of magnetic flux dynamics fixed by Magneto-Optical Imaging (MOI) method are presented in order to investigate origin and consequences of the anisotropic pinning model proposed, and implemented earlier experimental results including Guided Vortex Motion (GVM) phenomenon.
Thermomagnetic convection in a cylindrical enclosure. Part 1: Zero gravity
Authors: Krakov Mikhail S. , Nikiforov Ivan V.
Published: July 2018

The effects of a uniform external magnetic field on the thermomagnetic convection of magnetic fluid in a cylindrical enclosure are numerically studied. It was found that uniform magnetic field can be cause the convection in the non-uniformly heated magnetic fluid in a cylindrical enclosure even in the case of zero gravity. There are two threshold values of fluid magnetization and temperature gradient. Above the first threshold the convective flow is realized as circular flow, above the second one there are two cells in the enclosure. The angle between a magnetic field strength and a temperature gradient is found to be significant factor influencing structure of a convective flow and heat transfer control.
Frequency dependence of magnetothermal properties for magnetic fluid and magnetically functionalized implants
Authors: Salakhova R.T. , Vylegzhanin A. G. , Kashtanov E.A. , Zverev V.I. , Müller R. , de Sena Pereira F.D. , Parfenov V.A. , Mironov V.A. V.A. , Kritskaya E.A. , Pyatakov A.P. , Markov V.K. , Malyshev A.Yu , Kamilov K.I , Tishin A.M
Published: July 2018

Heating of the magnetic nanoparticles in AC magnetic field is the effect promising for application in medicine. The mechanisms of heating in AC-magnetic field implies nontrivial dependence of the power dissipated by magnetic nanoparticles on frequency. With the use of a reconfigurable experimental setup, this frequency-dependent magnetic heating was measured on two characteristic examples: the magnetite nanoparticles conventionally used in medicine and polymer coating with micrometer sized magnetite particles. The saturation of the heating power with frequency is shown that is more pronounced for the second case of microparticles.
Deformation of a magnetic liquid drop in an applied non-stationary uniform magnetic field
Authors: Tyatyushkin Alexander
Published: July 2018

Small steady-state deformational oscillations of a drop of magnetic liquid in a nonstationary uniform magnetic field are theoretically investigated. The drop is suspended in another magnetic liquid immiscible with the former. The Reynolds number is so small that the inertia can be neglected. The variation of the magnetic field is so slow that the quasi-stationary approximation for the magnetic field and the quasi-steady approximation for the flow may be used.
Research of the deformation of a thin body with a magnetizable elastomer in the magnetic field of a coil
Authors: Merkulov Dmitrii
Published: July 2018

Deformation of a thin cylindrical body with a magnetizable elastomer based on silicone in the magnetic field of an electromagnetic coil is investigated experimentally and theoretically. It is observed that a bistability of the thin body equilibrium shape exists at some values of the coil current. The method of measuring elasticity coefficients of the magnetizable elastomer in the Mooney – Rivlin model is proposed.
Magnetic fluid bridge between two cones and a cylinder in the magnetic field of a current-carrying wire
Authors: Vinogradova Alexandra S. , Turkov Vladimir A. , Naletova Vera A.
Published: July 2018

A magnetic fluid (MF) changes its surface shape in the magnetic field of a current-carrying wire while the current is changing. In the present paper, we propose to study a MF bridge which can open or close the channel formed by two cones and a cylinder by imposing the magnetic field of a wire. Numerical modelling of the bridge behavior for different values of MF volumes and currents in the wire is done for two cases: when the MF wets and does not wet surrounding solid boundaries. It is shown that the presence of limiting cones allows the MF to sustain the pressure drop which is much higher in case of non-wetting than in case of wetting. In case of wetting, the MF cannot sustain any pressure drop at low currents, but in case of non-wetting, the MF can do it even at zero current. It is found that in case of non-wetting, spasmodic and hysteresis phenomena are possible for some values of MF volumes and currents in the wire. The use of a MF in valves, dispensers and pumps is one of possible actuation methods.
Selected features of morpho-functional reactions of eukaryotic microorganisms grown in the presence of maghemite iron oxide nanoparticles obtained by laser target evaporation
Authors: Simonova Elena V. , Denisova Tatyana P. , Khandukhanov Roman T. , Melnikov Grigory Yu. , Medvedev Anatoly I. , Beketov Igor V. , Andrade Ricardo
Published: July 2018

Biological activity of iron introduced into nutrient medium as a suspension of iron oxide nanoparticles (MNPs) synthesized by the laser target evaporation was investigated. Exophiala nigrum (E. nigrum) eukaryotes were grown either in the presence or in absence of MNPs. De-aggregated suspensions of Fe2.75O4 MNPs were added in concentrations of 1 to 104 maximum permissive dose (MPD, being 0.3 mg/L of Fe ions in water). Cells were exposed for 24 to 96 hours periods and then plated onto a solid medium. The effect of MNPs was evaluated by the change in the number of cells during exposure and the number and morphology of the colonies. For 1-10 MPD yeast showed unaltered characteristics. For 100 or 1000 MPD for 72 hours of exposure and above the number of cells increases up to 30 times in comparison with the control. A pronounced stimulating effect was revealed at 104 MPD of iron. A significant excess of the number of cells was observed for the first day. At exposures of 72 and 96 hours the differences in the number of cells in comparison with the control were 11 and 30 times, respectively. A change in the colonies morphology was observed at 100 MPD concentration.
Methodological aspects of small iron concentrations determination in black yeasts grown in the presence of iron oxide nanoparticles
Authors: Melnikov Grigory Yu. , Denisova Tatyana P. , Safronov Alexander P. , Samatov Oleg M. , Khandukhanov Roman T. , Kulesh Nikita A. , Andrade Ricardo , Kurlyandskaya Galina V.
Published: July 2018

Nonpathogenic Exophiala nigrum (black yeasts) unicelular organisms of the Baikal Lake were used as a model system for determination of small iron concentrations in the samples grown without or with controlled amount of maghemite nanoparticles (MNPs) in nutrient. MNPs were produced by the electrophysical laser target evaporation technique. Electrostatically stabilized suspensions were prepared using sodium citrate solutions in distilled water. We assumed that one maximum permissive dose of ionic iron in water 1 MPD is equal to 0.3 mg/L. For biological experiments Saburo liquid nutrient medium was prepared with iron concentrations of 0, 102, 103 and 104 MPD. One ml of E. Nigrum cell suspension was added to Saburo liquid nutrient for 24 hours exposure. Followed by sowing onto a solid agar Saburo for 30 days colonies grows. Biosamples for electron microscopy, magnetic and total reflection X-ray fluorescence spectroscopy measurements were collected simultaneously. We were able to comparatively analyze the trace concentrations of iron in the yeast of the order of 10 ppm for control group and 600 ppm for the group grown in the presence of 104 MPD of iron.
Possibility to use of the Fe3O4/Ta2O5 core-shell nanoparticles in radiotherapy
Authors: Lukyanenko Kseniya , Afremov Leonid , Apanasevich Vladimir , Shmykova Mariya , Medkov Mikhail , Lukyanov Pavel , Tarakova Olga , Kustov Vladimir
Published: July 2018

The study was carried out of the possibility of using magnetic core-shell nanoparticles Fe3O4/Ta2O5 as a radio-modifier. It is investigated the influence of the inhomogeneous magnetic field on the distribution of the nanoparticles in the region of its maximum inhomogeneity. The increase of the core-shell nanoparticles’ concentration leads to the increase of the number of 511keV gamma-quanta. The absorption of gamma-quanta with lower energy (20-200 keV) increases with increase in concentration of nanoparticles.
Frustrations and phase transitions in magnets of various dimensionality
Authors: Kassan-Ogly Felix , Proshkin Alexey
Published: July 2018

We studied magnetic orderings, phase transitions, and frustrations in the Ising, 3-state Potts and
standard 4-state Potts models on 1D, 2D, and 3D lattices: linear chain, square, triangular, kagome, honeycomb, and body-centered cubic. The main challenge was to find out the causes of frustrations phenomena and those features that distinguish frustrated system from not frustrated ones. The spins may interrelate with one another via the nearest-neighbor, the next-nearest-neighbor or higher-neighbor exchange interactions and via an external magnetic field that may be either competing or not. For problem solving we mainly calculated the entropy and specific heat using the rigorous analytical solutions for Kramers-Wannier transfer-matrix and exploiting computer simulation, par excellence, by Wang-Landau algorithm. Whether a system is ordered or frustrated is depend on the signs and values of exchange interactions. An external magnetic field may both favor the ordering of a system and create frustrations. With the help of calculations of the entropy, the specific heat and magnetic parameters, we obtained the points and ranges of frustrations, the frustration fields and the phase transition points. The results obtained also show that the same exchange interactions my either be competing or noncompeting which depends on the specific model and the lattice topology.
Unconventional phase separation in the model 2D spin-pseudospin system
Authors: Budrin K.S. , Panov Yu.D. , Moskvin A.S. , Chikov A.A.
Published: July 2018

The competition of charge and spin orderings is a challenging problem for strongly correlated systems, in particular, for high-Tc cuprates. We addressed a simplified static 2D spin-pseudospin model which takes into account both conventional spin exchange coupling and the on-site and inter-site charge correlations. Classical Monte-Carlo calculations for large square lattices show that homogeneous ground state antiferromagnetic solutions found in a mean-field approximation are unstable with respect to phase separation into the charge and spin subsystems behaving like immiscible quantum liquids. In this case, with lowering of a temperature one can observe two sequential phase transitions: first, antiferromagnetic ordering in the spin subsystem diluted by randomly distributed charges, then, the charge condensation in the charge droplets. The inhomogeneous droplet phase reduces the energy of the system and changes the diagram of the ground states. On the other hand, the ground state energy of charge-ordered state in a mean-field approximation exactly matches the numerical Monte-Carlo calculations. The doped charges in this case are distributed randomly over a system in the whole temperature range. Various thermodynamic properties of the 2D spin-pseudospin system are studied by Monte-Carlo simulation.
Magnetic excitations of carbon nanotubes in chiral model of graphene
Authors: Rybakov Yu.P.
Published: July 2018

Within the scope of the chiral model of graphene in 8-spinor realization, suggested earlier [1, 2], the combined spinor field Ψ is used as a new order parameter, which contains information on spin and quasispin excitations in graphene (8-spinor part) and also that on sp-hybridization effect of carbon valence electrons [SU(2)-matrix part]. This model admits two kinds of configurations describing, in the long-wave approximation, the graphene mono-atomic plane and the carbon nanotube respectively. The first one is given by the domain-wall (or kink-like) solution and the second one is described by the hedgehog ansatz with large topological charge (winding number n). We consider the infinite carbon nanotube in a static external magnetic field oriented along the tube and analyze the structure of the magnetic intensity on the outside. The diamagnetic behavior of the material is shown by the perturbation method which proves to be self-consistent for n ≫ 1.
The Monte Carlo simulation of 2D ANNNI-model
Authors: Akai Kurbanovich Murtazaev , Zhavrail Gadzhievich Ibaev
Published: July 2018

In this, study we present the data for 2D Axial Next Nearest Neighbor Ising model (ANNNI-model) obtained from Monte Carlo (MC) simulations using the standard Metropolis algorithm. The temperature dependences of thermodynamic parameters for a cubic lattice with linear sizes L=32 at different values of the competing interaction parameter |J1/J|=0.1÷1.0. Transition temperatures of ferromagnetic ordering to the paramagnetic state at |J1/J|<0.3 and to the modulated state at 0.3<|J1/J|<0.5 are shown to shift towards low temperatures with an increase in a competing interaction parameter absolute value. Conversely, transition temperatures of the modulate state to the paramagnetic ordering grow. The modulated ordering in the 2D ANNNImodel appears in the temperature range 0.1<T<2.0 at 0.2<|J1/J|≤1.0. Modulated structure parameters are computed using a mathematic apparatus of Fourier transform spectral analysis. According to the Fourier analysis results, the wave number grows with an increase in the competing interaction parameter absolute value. Summarizing obtained results, we plot a phase diagram of 2D anisotropic Ising model with competing interactions.
The wave making resistance prediction of a mini-submarine by using tent function method
Authors: Sulisetyono Aries , Nugroho Yulianto Ardi
Published: July 2018

This paper describes the wave making resistance solution of a mini submarine operating in under water surface with different level depth. The Thin ship theory was adopted to solve the problem for a case of the slenderness body. The source distribution along the centre plane of the body was expressed in Green’s function of Havelock source potential under water surface. The Tent function method was proposed to illustrate the hull form based on offsets data, and to solve the Michell integral problem numerically. Four operational conditions were performed i.e. floating, snorkelling, and diving with 0.5m and 1m under water surface. The computational results for the mini submarine with length of 2m and diameter of 0.25m explained a more deeply operated under water surface cause to decrease a value of wave making resistance for all cases of Froude numbers. While in the diving conditions of 0.5m and 0.1m under the water surface, the wave making resistance were resulted about 64% and 74% less than the case of floating condition respectively. Furthermore, the effect of vertical fin on the body was investigated, where the wave making resistance could increase average 7.2% in snorkelling, 11.4% in 0.5m diving, and in the 1m diving about 9.07% for all Froude numbers. Over all the results of this approach shown a good agreement with the results come from Mitchell code.
Coastal Monitoring Program of Bathymetry Using Video Images Technique
Authors: Zikra Muhammad , Hashimoto Noriaki
Published: July 2018

The objective of this research is to investigate the capabilities of optical remote sensing to monitor bathymetry in nearshore area using video images. The technique is designed to extract wave number components based on variation of intensity of brightness at each pixel in the images using cross-spectral correlation approach. This approach is based on pixel array analysis that utilizes a nonlinear inverse method ‘Levenberg-Marquardt’. The technique is applied to the data collected at Hasaki beach in Japan from August to December 2006. The results indicate that the estimate of nearshore bathymetry is proved reasonable accurate near shoreline and breaking area where the differences between estimated and survey water depth are less than 10-30 cm.
Development of Ecotourism Floating Restaurant in Surabaya City
Authors: Setyo Koenhardono Eddy , Sarwito Sardono , Saut Gurning RO , Badrus Zaman M. , Baheramsyah Alam , Ranu Kusuma Indra , Cahyono Beni , Prananda Juniarko , Yulianto Totok , Hasannudin
Published: July 2018

In the 18th century, Kalimas’s river serves as a workspace, marketing space, and transportation routes for residents of Surabaya. Although the current condition of Kalimas river has changed a lot, but Kalimas’s river has good potential of water tourism and transportation facilities. Therefore, the Surabaya city government setup a policy to revitalize the Kalimas’s River. The submarine monument area as one of Surabaya's landmarks next to Kalimas’s River will be developed as a 'Riverside Center Business Center'. One feasible way to support the city government program is the development of a floating restaurant. Floating restaurant is just a place to eat, when doing business negotiations or family tours. The concept of floating restaurant development based on ecotourism. Hence, this restaurant is designed environmentally friendly, empowering local people, and become a means of learning and education. The eco-friendly concept is manifested in a flat outward-side asynchronous catamaran form and battery-based electric propulsion systems and solar panels. The menus are provided by local vendors along the river bank of Kalimas so the local food supplier will be more empowered.
Comparative of Feasibility Study Between Diesel Mechanical Propulsion System and Combination of Diesel Engine and Electric Motor Propulsion System on Offshore Patrol Vessel (OPV) 80 m
Authors: Setyo Koenhardono Eddy , Amiadji
Published: July 2018

The modern offshore patrol vessel is designed to carry out various missions in the management of economic exclusion zones, thus having some speed of service. For example, the speed for slow patrol is 10 knots, regular patrols 18 knots and chasing 22 knots. This condition requires a flexible propulsion system, which is combination of mechanical and electrical propulsion system. The application of this propulsion system to the OPV can increase the load factor of the propulsion system, resulting in lower fuel consumption than when using a mechanical propulsion system. Based on feasibility analysis results, the choice of combination of mechanical and electrical propulsion system is more advantageous than mechanical propulsion system, although investment and maintenance cost is higher. Therefore, patrol boats should use combination of mechanical and electrical propulsion system.
Domestic Waste Mass Estimation and Perceptions of Coastal Citizen about Waste Management in Besuki Region, Situbondo, East Java, Indonesia
Authors: Sakinah Wazirotus , Septiningtyas Dina T , D Pahlewi Anita
Published: July 2018

Coastal citizen in Besuki region have a habit of throwing garbage directly into estuary and sea. To know the bad conditions that can occur in the marine environment especially in Besuki region so domestic waste mass estimation is needed. Proportional random sampling is used to determine the number of samples and measurement of domestic waste is conducted for 8 days. Measurement with SNI (Indonesia National Standard) Number 19-3964-1994 method is used. To know perceptions of coastal citizen about waste management, the distribution of questionnaires to the sample was done. The result is waste mass estimation in Besuki Coastal Region is 167.57 g/people.day where non-organic waste more than organic waste that has percentage 63% and 37%, respectively. From questionnaire survey, 73% citizen throw their wastes in the sea or/and the river, 27% has been burned, and 0% in landfill. Generally, 80% citizens do not have the basic knowledge about marine debris impact and 20% citizens have knowledge about marine debris impact. Their interest about self-waste management is 33%.
Determination of shoreline change along the East-Java coast, using Digital Shoreline Analysis System
Authors: den Boer Eva Louise , Suntoyo  , Oele A C
Published: July 2018

This study focused on determining the shoreline change at the East-Java coast by comparing the shorelines between 2006 and 2015, using digital shoreline analysis system (DSAS) techniques to identify and measure erosion (shoreline retreat) and accretion (shoreline advance). Shoreline change rates are calculated according to Shoreline Change Envelope (SCE), Net Shoreline Movement (NSM), End Point Rate (EPR), and Linear Regression Rate (LRR). Results present local variations in shoreline change distance as well as in shoreline change rates. The statistical methods showed similarities with the highest accretion distance of 991.57 meters in the region of Mulyorejo and highest erosion distance of 928.75 meters in Sidoarjo. The EPR shows a rate with a maximum of 169.98 m/year and a minimum of 3.428 m/year. As for the LRR a maximum of 189.58 m/year and a minimum of 5.467 m/year were conducted from calculations.
Identification of factors influence to complétion of adoption procès of ecolabel in fisheries product
Authors: Purwaningsih Ratna , Susanty Aries , Khaifa Wafa Amru , Arvianto Ary , Ariany Zulfaidah
Published: July 2018

This study aims to determine what factors affect consumers in the process of adoption of eco-label on fishery products and provide program recommendations to improve eco-label adoption. The study used primary data through the questionnaire in a Likert scale 1-5 to 200 respondents in Semarang City, Central Java Indonesia. The process of adoption of eco-label is divided into two phases: initiation of adoption process and completion of the adoption process, the discussion focus on completion phase. Hypothesis testing is done by multiple linear regression analysis. The results indicate that in the phase of completion of the adoption process, consumer buying intention and consumer experience is moderator variable that has the greatest influence to accelerate the completion of the adoption process.
Sedimentation Modeling For Development of Kenjeran - Surabaya
Authors: Winda Amalia Herdianti , Suntoyo  , Wahyudi
Published: July 2018

Surabaya City administratively has a maritime boundary consisting of 11 districts known as Pantai Timur Surabaya (Pamurbaya). One of them is Kenjeran area. The area located in the Development Unit 3 in the Urban Spatial Plan (RTRW) used as a Service and Trade Area and also used as a Tourism Area. Therefore, this study is important to know the shoreline changes and made recommendations in zone management development. Results of this study found that the area of Kenjeran dominated by sedimentation with sedimentation range 0.002-0.015 meters. The largest sedimentation is 2.36x106 m2 with sedimentation of 0.02 meters. Development of the area in Kenjeran is suitable with the RTRW Surabaya, but due to the large sedimentation, there are some things that must be considered such as the uncertainty of land ownership arise in Kenjeran and ecosystem damage. The solution offered is that the government should restrict the use of arising land and there should be clarification of rules from the government on arising land.
Study on ultimate strength of ship’s hull considering cross section and beam finite element.
Authors: Muis Alie Muhammad Zubair , Juswan  , Wahyuddin  , Rachman Taufiqur
Published: July 2018

The objective of the present research is to study the ultimate strength of ship’s hull considering cross section and beam finite element under longitudinal bending. The single hull bulk carrier and double hull oil tanker are taken to be analysed. The one-frame space of ship is considered in the calculation. The cross section of ship’s hull is divided into element composed plate and stiffened plate. The cross section is assumed to be remained plane and the simply supported is imposed to both side of the cross section. The longitudinal bending moment is applied to the cross section for hogging and sagging condition. The Smith’s method is adopted and implemented into the in-house program of the cross section and beam finite element to calculate the ultimate strength of ship’s hull. The result of the ultimate strength for hogging and sagging condition obtained by considering the cross section and beam finite element is compared with one another.
When to abandon the search for an elusive gastrointestinal bleeding source
Authors: Sonnenberg Amnon
Published: July 2018

Background and study aims In some patients with gastrointestinal bleeding, even multiple consecutive endoscopic procedures fail to achieve lasting hemostasis. The current decision analysis was designed to answer the question of when to continue or abandon a sequence of endoscopic attempts of endoscopic hemostasis.

Materials and methods A decision tree with a threshold analysis was used to model the decision between continued endoscopy or expectant management. A low threshold probability was indicative of a preferred management option.

Results For continued endoscopy to be the favored decision, its probability of success in achieving hemostasis needed to exceed the success probability of expectant management by a greater amount than its costs exceeded those of expectant management. Endoscopic attempts at hemostasis should be discontinued if the costs of endoscopy are high compared with those of expectant management. The endoscopic attempt should be continued, if its probability for achieving lasting hemostasis is high.

Conclusions Such principles are applicable as rule of thumb in managing patients with ongoing chronic gastrointestinal bleeding.
White opaque substance visualized by magnifying narrow-band imaging is associated with intragastric acid conditions
Authors: Togo Kazumi , Ueo Tetsuya , Yao Kenshi , Wada Kurato , Honda Hideho , Inoue Syotaro , Fukuda Masahide , Yanai Yuka , Yonemasu Hirotoshi , Murakami Kazunari
Published: July 2018

Background and study aims The presence of white opaque substance (WOS) is an endoscopic marker of intestinal metaplasia. Considering that the nature of WOS is absorbed lipid droplets, lipase plays an important role in the lipid absorption process and is inactivated at strong acidity. WOS may only be present in a hypochlorhydria state following Helicobacter pylori infection, and, thus, may not be highly sensitive marker, especially in H. pylori-eradicated patients. We investigated the relationship between WOS and gastric acid conditions.

Patients and methods A total of 501 patients were retrospectively evaluated for the presence of WOS at 2 regions of interest using magnifying narrow-band imaging. The pH level of collected gastric juice was also measured. Study end points were (1) prevalence of WOS and its relationship with gastric juice pH in 3 groups: H. pylori-uninfected, H. pylori-infected, and H. pylori-eradicated; (2) the relationship between prevalence of WOS and gastric juice pH before and after proton pump inhibitor (PPI) administration in 29 H. pylori-eradicated cases.

Results Prevalence of WOS was 0 % (0 /206), 28.4 % (31/109), and 3.2 % (6/186) in the H. pylori-uninfected, H. pylori-infected, and H. pylori-eradicated groups, respectively. Mean gastric juice pH was significantly higher in WOS-positive cases than in WOS-negative cases in the H. pylori-infected and H. pylori-eradicated groups (P < 0.0001). Mean gastric juice pH increased from 1.1 to 6.9 after PPI administration and WOS prevalence increased from 0 % (0/29) to 45 % (13/29) of cases.

Conclusion The prevalence of WOS is closely associated with the neutralization of intragastric pH.
Plastic stents are more cost-effective than lumen-apposing metal stents in management of pancreatic pseudocysts
Authors: Chen Yen-I , Khashab Mouen , Adam Viviane , Bai Ge , Singh Vikesh , Bukhari Majidah , Brewer Gutierrez Olaya , Elmunzer B. , Moran Robert , Fayad Lea , El Zein Mohamad , Kumbhari Vivek , Repici Alessandro , Barkun Alan
Published: July 2018

Background and study aims Endoscopic ultrasound-guided drainage is an effective and accepted primary modality for management of pancreatic pseudocyst (PP). A lumen-apposing metal stent (LAMS) has recently been developed specifically for drainage of pancreatic fluid collections which may be superior to using traditional plastic stents (PS) but is more expensive. Because use of a stent involves a risk of unplanned endoscopy, percutaneous drainage (PCD) and surgery, their costs should also be included in the comparison and a cost-effectiveness analysis of LAMS and PS should therefore be performed

Patients and methods A decision tree was developed assessing both endoscopic drainage strategies for patients with PP: LAMS and PS over a 6-month time horizon. For each strategy, inpatients received a stent and were followed for subsequent need for direct further interventions or adverse events leading to unplanned endoscopy, PCD, surgery, or successful endoscopic drainage using probabilities obtained from the literature. The unit of effectiveness was successful endoscopic drainage without need for PCD or surgery. Sensitivity analyses were performed.

Results Success rates were 93.9 % for LAMS and 96.96 % for PS. Respective costs per successful drainage were US $ 18,129 (LAMS) and US $ 10,403 (PS). The LAMS strategy was thus characterized as dominated by the PS approach because it was costlier and less effective than PS. Both deterministic and probabilistic sensitivity analyses confirmed the robustness of these findings.

Conclusion Use of LAMS is not less effective and more costly than PS in management of patients with PP. As such, PS should be preferred over LAMS as initial management of these patients.
Update Muskel- und Bandverletzungen an der unteren Extremität: Mechanismen, Verletzungsarten, Interventionen
Authors: Schmitt Holger
Published: July 2018

Verletzungen an der unteren Extremität sind sehr häufig der Grund für unfreiwillige Unterbrechungen der sportlichen Aktivität. Eine optimale Versorgung ist daher
für die schnelle Rückkehr zum Sport unerlässlich. Dieser Artikel informiert Sie über den aktuellen Stand der ärztlichen Therapie bei Verletzungen von Muskeln,
Menisken und dem vorderen Kreuzband.