bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Alumina Source and Soaking Time on Properties of Refractory Mortar Using as Slumping Mold
Authors: Nawaukkaratharnant Nithiwach , Wiratphinthu Bordin , Nilpairach Siripan , Mongkolkachit Charusporn , Wasanapiarnpong Thanakorn
Published: April 2014

Slumping molds or sagging molds are utilized for shaping glassware containers and many kinds of slumped glass products from glass plates. In Thailand, a large number of slumped glass factories use such molds in their production because slumping process is easy and cheap; however, the major cost of this process is slumping molds. They are imported from other countries and are expensive. In this research, slumping molds are created from local raw materials using the basic method to reduce the cost of the production. One of proper materials for making slumping mold is refractory mortar which can be easily formed into various shapes and sizes. Consequently, it is interesting to prepare slumping molds from refractory mortar. In this study, the effect of different sources of alumina (calcined alumina and aluminum sludge) and soaking time on the properties of the refractory mortar were investigated. Dolomite clay, milled sand and white portland cement were mixed with sources of alumina in distilled water to form pastes. Super plasticizer was added to the pastes to adjust flow ability. Plastic containers were used as molds for specimen forming. Specimens were cured at room temperature for 24 hours and dried in air for 24 hours. After that specimens were dried in an oven at 110 °C for 24 hours and then fired at 1100 °C. The result showed that the suitable condition for making slumping mold is to use calcined alumina as a source of alumina with soaking temperature of 1100 °C for 4 hours. The physical properties, chemical properties and thermal properties were discussed.
Crack Evolution from Ballistic Threats in Laminated Glass
Authors: Chaichuenchob Chidchanok , Aungkavattana Pavadee , Kochawattana Sujarinee
Published: April 2014

Laminated glass is widely used as safety material and transparent armor. Its typical structure is sandwich layers of glass sheets and Poly Vinyl Butyral (PVB) film. It is known that the ballistic performance of the laminated glass is highly influenced by its configuration. In this study, the damages from ballistic threats at level 3 according to NIJ standard in laminated glass were investigated. Laminated glass with various configurations was fabricated using rolling and vacuum techniques. The ballistic tests were performed and the resulting radial cracks, which intercept several circumferences on each sheet of glass, were quantified. It was found that the number of crack bifurcation and the configurations of laminated glass were significantly correlated. The tested specimens were also cross-sectional observed using water jet cutting machine so that, their ballistic penetration could be determined. The analysis results provide better understanding of crack evolution, leading to improved new transparent armor system.
Development of Engobe Samples for Dan Kwian Ceramic Body
Authors: Luangnaem Chaisiri , Sathonsaowaphak Apha , Kamon-In Onlamee , Pimraksa Kedsarin
Published: April 2014

This paper developed engobe samples for Dan Kwian ceramic body. Kaolinite clay, zirconium silicate, sodium feldspar and quartz were used as raw materials which were varied to obtain various samples. Mix proportion was designed by the square sampling method to obtain 16 samples. All samples were milled and fired at 1200°C under oxidation and reduction atmospheres. The results showed that the suitable engobe composition of kaolinite clay 10 wt%, zirconium silicate 10 wt%, sodium feldspar 40 wt% and quartz 40 wt% to produce good surface appearance for Dan Kwian ceramics. Engobe surfaces and the body had no defect both in the oxidation and reduction atmospheres. The color and engobe surface were opaque white and glossy, respectively.
Underglaze Tissue Printing for Ceramic Artists, a Collaborative Project to Re-Appraise 19th Century Printing Skills
Authors: Hoskins Stephen , Huson David
Published: April 2014

Under-glaze tissue ceramic transfer printing first developed circa 1750 and involved engraved or etched copper plates, from which tissue was printed with cobalt blue oxides. Under-glaze tissue has a very distinctive, subtle quality - it is an integral part of both English ceramic history and the history of copperplate engraving. The process was common in the UK ceramics industry until the1980s. However from the 1950s it began to be supplemented by screen-printing, because underglaze tissue transfer was relatively slow and required skilled artisans to apply the transfers. The authors are collaborating with Burleigh Pottery in Stoke-on-Trent, the last remaining company to produce ceramic tableware decorated using the traditional printed under-glaze tissue method. The pottery was recently saved from closure by the HRH Prince Charles Regeneration Trust, who wish to maintain the traditional manufacturing skills for the next 25 years. The Centre for Fine Print Research (CFPR) in Bristol has been reappraising the use of these traditional 19th Century skills with modern materials and methods for producing engraved plates. The project seeks to demonstrate how those 19th Century methods can be applied by contemporary ceramic artists. The paper will explain the process of ink manufacture, heating the plate for printing, digital methods of making plates and the use of potters tissue.
3D Printed Ceramics for Tableware, Artists/Designers and Specialist Applications
Authors: Huson David , Hoskins Stephen
Published: April 2014

The Centre for Fine Print Research at the University of the West of England has over five years experience in the 3D printing of ceramic materials. The first project undertaken was to investigate the use of 3D technologies for artists and resulted in the development of a patented ceramic body suitable for use in Z Corporation 3D printers. After bisque firing this material can be further processed using conventional glazing and decorating techniques. A follow on project has resulted in a modified ceramic body and the development of firing supports to enable thin section ceramic tableware to be produced for ceramic industry concept modelling and short run or one-off pieces for artists and designers. This paper will detail the progress of the research and will explain by using case studies and examples of collaboration with a leading UK pottery manufacturer, individual artists and designers how this novel technique can be utilised to form shapes and forms difficult or impossible to realise by conventional forming methods. The potential of how the ability to form ceramic objects with complex internal structures could be beneficial to more specialist ceramics industries will also be explored.
Effect of Al2O3, CaCO3 and MgCO3 on Physical Properties of Crawling Shino Glaze in Reduction Atmosphere
Authors: Junta Sarunyu , Mulinta Soravich , Saitan Adul , Ruammaitree Kanokkanya
Published: April 2014

The purpose of this research was to study the effect of Al2O3, CaCO3 and MgCO3 on the physical properties of crawling shino glaze at 1250 °C in a reduction atmosphere. The raw material used in the study are soda feldspar, lampang kaolinite and silica. Al2O3, CaCO3 and MgCO3 were used in ungrounded form as an additive at 5, 10, 15 and 20%wt. The specimen after fired were tested using eye appearance, texture, color of glaze and shrinkage. The results show that the optimum appearance Shino glaze was gained by adding MgCO3 at 15%wt.
Properties of Dan Kwian, Sukhothai and Ratchaburi Pottery Clays Fired at 700 and 900 °C
Authors: Meethong Nonglak , Pattanasiriwisawa Wanwisa , Somphon Weenawan , Tanthanuch Waraporn , Srilomsak Sutham
Published: April 2014

Dan Kwian, Sukhothai and Ratchaburi pottery clays are economically important pottery clays. They are well known in the Thai ceramic society for making Dan Kwian pottery, Sawankhalok pottery and Dragon jars, respectively. There have been several studies of these pottery clays. However, few of them used statistics to analyze their results. This work is a comparative study of the compositions and properties of these three pottery clays using statistical software to analyze the results. Results show that the major components of these pottery clays are SiO2 and Al2O3. The Modulus of Rupture (MOR) of each pottery clay fired at 700°C are not significantly different. Sukhothai pottery clay fired at 900°C has a higher MOR and bulk density while its porosity, water absorption and apparent specific gravity are less than those of the Dan Kwian and Ratchaburi pottery clays fired at the same temperature. Additionally, the current study developed regression equations for estimating the properties of all pottery clays under study. Finally, it was found that the L*, a*, b* and reflectance spectra of all pottery clays increased when firing temperature was increased from 700 to 900°C.
Foam Glass Development Using Glass Cullet and Fly Ash or Rice Husk Ash as the Raw Materials
Authors: Chakartnarodom Parinya , Ineure Pitcharat
Published: April 2014

The aim of this work is to study the recycling of glass cullet (waste glass), fly ash, and rice husk ash as the foam glass, a porous construction material having high compressive strength but low density, which are similar to the light weight brick. The foam glasses were prepared by mixing the ground glass cullet/ash mixtures with calcium carbonate (foaming agent) at 1 wt% and sodium silicate solution (binder) at 10 wt%, and then compacted into the rectangle shapes (30 cm × 30 cm × 7cm) which were fired at 650 °C for 30 min, and then for 1 hour at 750, 800, 850, or 900 °C. The sources of glass cullet were art glass factory and glass window industry. The percentages of ash in the ground glass cullet/ash (fly ash or rice husk ash) mixtures were 20, 40, and 60 wt%. The results showed that the foam glass that was made from 80wt% window glass/ 20wt% fly ash and fired at 750 °C had the most suitable properties for being produced commercially because it had good alkaline resistant, and the compressive strength and degree of water absorption better than the light weight brick (G2-type and G4-type autoclaved aerated concrete) while the density was similar to G2-type but lower than G4-type. The compressive strength, density, and degree of water absorption of this foam glass were 59.9 kg/cm2, 421 kg/m3, and 2.1 % respectively. Furthermore, as of September 2013, the total production cost (materials, labor, energy, etc.) of this foam glass is about 16 baht per piece (20 cm × 60 cm × 7.5 cm) which is 12.5 to 43.75% lower than the wholesale price of a light weight brick (18-23 baht per piece for G2-type and G4-type autoclaved aerated concrete).
Preparation of Xylem-Imitating Porous Ceramic by Coconut Coir and Pottery Clay
Authors: Phungsripheng Siwas , Pornprasertsuk Rojana , Wasanapiarnpong Thanakorn
Published: April 2014

The transport of water through xylems in tree is one of the most efficient transport mechanisms. Porous conventional ceramic is one way to mimic capillary force in xylem, which was operated by mixing pottery clay with volatile natural fiber (coconut coir) and extruded into 30 millimeter in diameter rod. The coconut coir content in the mixtures was varied from 0 to 8 wt% of dried clay. Dried samples were fired at 800 °C and 900 °C for 2 h to burn out the coconut coir. The water transport performance test of samples is performed by immersing 3 cm of the initial parts of samples in water and observe watermark at 1, 2, 4, 8 and 16 h under the humidity and temperature controls at 60% and 30 °C, respectively. The sample with the 8 wt% coconut coir after firing at 900 °C showed the highest watermark level at 45 cm from the initial point and the highest water transpiration rate of 2.275 g/h.
Development of Ceramic Candle Filters by Slip Casting Process
Authors: Islam Md. Fakhrul , Rizvi Mehedi Hasan , Khan Towkir Ahmed , Hasanuzzaman Muhammad
Published: April 2014

A well-defined porous ceramic having effective pore size less than 1 µm was fabricated by slip casting technique which provides a low-cost and single-stage filtration process. This single-stage filtration process removed suspended solids and pathogenic organism. In this study, diatomaceous earth was used as pore forming agent in clay based ceramic body. Varied amount of diatomaceous earth was used with fixed proportion of china clay, ball clay and lime stone. X-ray fluorescence spectroscopy (XRF) was used to determine the composition of raw materials and final sintered filter body. In terms of porosity and flow rate, 25% diatomaceous earth shows better filtration property. It was found that total porosity increased with decreasing milling time. As the firing temperature increased, porosity decreased rapidly after 1100 °C. However, the change of porosity in firing range of 1000 °C–1100 °C was found very small. Mercury intrusion porosimetry was used to measure the pore size and its distribution. An effective intra-particle pores in a range of 0.2-0.5 μm was identified. Inter- and intra-particle pores were observed using scanning electron microscope (SEM). Microbial removalefficiency of 99.99% was measured, while water flow rate was found in a range of 200-700 ml/hour.
Percolation Effects in Composites Superconductor – Ferromagnetic Half-Metal
Authors: Kononenko Victoria V. , Tarenkov V.Yu. , Dyachenko A.I. , Varyukhin V.N.
Published: April 2014

We investigated transport characteristics of composite that consist of the superconductor MgB2 and ferromagnetic half-metallic nanoparticles La0.7Ca0.3MnO3 (LCMO). The experiments were carried out in a wide temperature range with different volume content of the magnetic impurity. It was found that over 25% of the impurity manganite breaches percolation paths of the diboride magnesium. This leads to a considerable broadening of the MgB2 superconducting transition and the formation of the network of contacts through the ferromagnetic inclusions. This result shows the possibility of the spin - activated surface realization on the superconductor - manganite boundary. It's allowing the free transition of Cooper pairs with s wave symmetry of the order parameter in a ferromagnet with 100% spin-polarized carriers.
Magnetoelastic Resonance in Media with the Inhomogeneous Coupling Parameter
Authors: Ignatchenko Valter A. , Polukhin Dmitry S.
Published: April 2014

The matrix Greens function of coupled spin and elastic waves for media with the 3D inhomogeneities of the coupling parameter is studied. It has been shown that the difference in shapes of the Greens functions for the cases of 1D and 3D inhomogeneities appears only for the sufficiently large correlation wave number of the inhomogeneities.
First Principles Calculations of Magnetic Exchange Parameters of Fe-Mn-Al Heusler Alloys
Authors: Zagrebin M.A. , Buchelnikov Vasiliy D. , Sokolovskiy V.V. , Taranenko I.A. , Saunina S.I.
Published: April 2014

The composition dependences of magnetic exchange couplings for the cubic phase of Fe2+xMn1-xAl Heusler alloys, where 0.0 < x < 1.0 are obtained with the help of first principles calculations. Our simulations have shown that the Fe-Fe nearest neighbors present a strong ferromagnetic coupling. Moreover, these exchange interactions are larger than the other ones.
Coercivity of Amorphous Со-Р Single-Layer and Trilayer Films Fabricated by Chemical Deposition
Authors: Chzhan Anatoly V. , Kiparisov Semen Y. , Patrin Gennagy S.
Published: April 2014

Coercivity of amorphous Co-P single-layer and trilayer films fabricated by chemical deposition has been investigated. It has been established that the thickness dependences of the coercivity for isotropic and anisotropic films are different. Data on the coercivity variation with a nonmagnetic spacer thickness and a number of magnetic layers in the trilayer films are reported. The results obtained are analyzed with regard to the features of the induced anisotropy in amorphous ferromagnetic films and the magnetic coupling between magnetic layers in sandwich structures.
Uniaxial Magnetic Anisotropy of Bismuth-Doped Ferrite-Garnet Films, Induced by Weak Adsorption
Authors: Zubov Victor E. , Kudakov Andrey D. , Levshin Nikolay L.
Published: April 2014

Abstract. With the use of magneto-optical Faraday effect effective field of perpendicular magnetic anisotropy of iron garnet films is measured in vacuum and in the atmosphere of water vapor. It is established that a decrease of the mentioned field takes place due to adsorption of the water molecules by 20% in comparison with the value of field in vacuum. This result is in accordance with the conclusion reached on the base of investigation of influence of water molecules adsorption on domain structure of iron garnet films earlier.
Ising Antiferromagnet with Nearest-Neighbor and Next-Nearest-Neighbor Interactions on a Square Lattice
Authors: Murtazaev Akai K. , Ramazanov Magomedsheikh K. , Badiev Magomedzagir K.
Published: April 2014

The critical properties of two-dimensional antiferromagnetic Ising model in square lattice are investigated using the replica Monte-Carlo method with account of interactions of second nearest neighbors. The diagram of critical temperature dependence on an interaction value of second nearest neighbors is plotted. Static critical exponents of the heat capacity α, susceptibility γ, magnetization β, and correlation radius ν are calculated for this model using the finite-size scaling theory.
Structure Evolution of Fe- and Co-Based Amorphous Alloys Studied by the Electrical Resistivity Measurements
Authors: Kotvitckii Aleksandr , Kraynova Galina , Frolov Anatoly , Ivanov Vitaly , Plotnikov Vladimir
Published: April 2014

The subject of this study is the change of the electrical resistivity of Fe-based metallic glasses during heat treatment. Electrical resistivity is a structure-sensitive characteristic of materials. In metallic glasses, the scattering of conduction electrons on the disordered structure is the main mechanism responsible for the electrical resistivity. Hence amorphous metallic alloys have a much higher residual resistivity as compared to their crystalline analogs. It is typical for metallic glasses that the temperature coefficient of resistivity (TRC) is smaller than for the corresponding crystalline materials, and it can be either positive or negative.
Evolution of Structure-Scaling and Magnetic Properties during Thermal Loading of Melt-Spun Fe70Cr15B15(Sn) Alloys
Authors: Pisarenko Tatiana A. , Frolov Anatoly , Kraynova Galina
Published: April 2014

We have studied the scaling evolution of the structure and magnetic properties of the melt-spun Fe70Cr15B15(Sn) alloys. The magnetic percolation cluster about the percolation threshold forms at the vitrification stage that is determined by both the kinetics of magnetic and of transport properties and the variation of fractal dimensionality. Alloying by tin of contact surface of ribbon decreases the temperature of the cluster formation. It is shown that the evolution of a fractal ordering affects the kinetics of the physical properties of the alloys. The spectra of fractal dimensionality identify the symmetry character of melt-spun alloys. Fractal dimensionDfis reduced at the increasing complexity of hierarchical system.
Fundamental Limitations of Half-Metallicity in Spintronic Materials
Authors: Solontsov Alexander
Published: April 2014

Zero-point spin fluctuations are shown to strongly influence the ground state of ferromagnetic metals and to impose limitations for the fully spin polarized state assumed in half-metallic ferromagnets, which may influence their applications in spintronics. This phenomenon leads to the low-frequency Stoner excitations and cause strong damping and softening of magnons in magnetoresistive manganites observed experimentally.
Phase Transition in Ultrathin Films
Authors: Afremov Leonid L. , Petrov Aleksandr A.
Published: April 2014

Within the frame of average spin the dependence of Neel temperature of ultrathin antiferromagnetic film for FCC crystalline lattice on its thickness and the concentration of magnetic atoms has been defined. The λ values calculated by us are close to experimental values obtained for the films СoO/SiO2. The increasing of thickness leads to decreasing of the critical concentration down to the value equal to percolation threshold.
Effect of Sodium Hypophosphite Content to the Deposition Rate, Structure and Magnetic Properties of Electroless Deposited Ni-P Alloy
Authors: Yaroslavtsev Roman N. , Chekanova Lydia A. , Komogortsev Sergey V. , Iskhakov Rauf S.
Published: April 2014

The deposition kinetics, structure and magnetic properties of electroless deposited films Ni-P were investigated depending on the amount of sodium hypophosphite in the electroless bath. It was found that the film deposition rate is linear and unambiguously varies with the hypophosphite content from 2 to 13 g/l and from 23 to 25 g/l. The deposition rate varies widely in the hypophosphite concentration range from 13 to 23 g/l. The films are composed of amorphous Ni-P phase and fcc Ni-P solid solution with phosphorus content from 1 to 4 at.% P according to X-ray diffraction. The partial amount of amorphous phase is increased with concentration of sodium hypophosphite. The ferromagnetic resonance field is independent on the concentration of sodium hypophosphite, which assumes to be result from the laminated allocation of the amorphous and fcc phases in the film.
Perpendicular Magnetic Anisotropy and Atomic Ordering in FePd, Fe50Pd50-xPtx Alloy Films
Authors: Artemyev Evgeny M. , Yakimov Lev E.
Published: April 2014

Phase composition, crystal structure and magnetic properties of ordering FePd and Fe50Pd50-xPtx(х = 1-10 atomic %) alloy films were studied. Spectral dependencies of Faraday rotation and optical absorption were measured. We studied how thermal treatment affects crystal structure, magnetization and coercive force in ordered alloys and how the degree of atomic order affects the value of perpendicular magnetic anisotropy. It was shown that near equiatomic ordered FePd and Fe50Pd50-xPtx(х = 1-10 at. %) alloy films can be used as medium for magnetic and thermo-magnetic data recording.
Phase Transitions in the Two-Layer Ferrite-Garnet Film
Authors: Siryuk Julia A. , Bezus Alexey V.
Published: April 2014

The peculiarities of domain structures (DS) have been investigated in the two-layer film of (YGdTm)3(FeGa)5O12/(YEu)3(FeGa)5O12 composition with a magnetic compensation point (TC) in one of the layers and in the single-layer witnesses-films. It is shown that a change in the ratio of energies of magnetostatic and exchange interactions between the layers under temperature change induces a phase transition (PT) in the domain structure and a spin-reorientation phase transition (SRPT).
Morphology and Structure of the Interface Layers in Ni/Ge Thin Films
Authors: Greben'kova Yuliya E. , Edelman Irina S. , Chernichenko Angelina V. , Velikanov Dmitry A. , Zharkov Sergey M. , Turpanov Igor A.
Published: April 2014

Morphology and structure of the interface in Ni/Ge thin films being due to the mutual diffusion of these elements are investigated with the help of atomic force microscope, high resolution electron microscope and micro-diffraction. Strong effect of interface in magnetic behavior of Ni layers is demonstrated and explained by formation of magnetic order in the interface and rough boundaries between layers.
Influence of Heating Temperature on the ΔЕ-Effect of Amorphous Fe75Si10B15 Wires
Authors: Semenov Andrey , Golygin Evgeniy , Gavriliuk Alexey , Mokhovikov Alexander , Gafarov Alexander , Morozova Natalia
Published: April 2014

In the present work we have investigated the influence of the thermocycling on the magnetoelastic parameters (the ΔЕ-effect) of amorphous Fe75Si10B15 wires, which had been pretreated by dc current j with simultaneous applying of the tensile stresses σ. It was figured out the ΔЕ-effect behavior depends strongly on pretreatment circumstances. Namely, we have got the maximum absolute value of the ΔЕ-effect shifted into direction of the higher magnetic field magnitude at j<39 MA/m2 and σ<127 MPa. In addition, the negative ΔЕ-effect was not observed for samples, pretreated at j≥45MА/m2 or σ≥128 MPa . The features of such a behavior of the ΔЕ-effect were explained in terms of the magnetoelastic coupling between the inner core and the outer shell of the amorphous wire.
Magnetic and Magnetoresonance Properties of Multilayered Systems Based on (CoFeB)x-(SiO2)100-x Composite Layers
Authors: Chekrygina Ju. , Devizenko A. , Kalinin Y. , Kirov S. , Lebedeva E. , Shipkova I. , Sitnikov A. , Syr’ev N. , Vyzulin S.
Published: April 2014

Magnetic properties and ferromagnetic resonance data of (Co41Fe39B20)x-(SiO2)100-x composite films and multilayer structures composed of these films separated by SiC interlayers have been studied. It has been shown that one of the possible causes responsible for the differences of magnetic properties of composites and multilayer structures can be different shapes of magnetic particles and granules in these materials.
Electronic Structure and Magnetic Properties of Iron Doped TiO2 (Rutile): XPS Measurements and CPA Calculations
Authors: Korotin Michael A. , Skorikov Nikolay A. , Kurmaev Ernst Z. , Zatsepin Dmitry A. , Cholakh Seif O.
Published: April 2014

X-ray photoelectron spectra of TiO2:Fe are measured. Electronic structure and magnetic properties of rutile doped by iron are calculated in frames of the coherent potential approximation. The main experimental spectral features of TiO2:Fe such as heterovalent cation substitution (Fe3+→Ti4+), decreasing of the band gap value and appearance of additional features at the bottom and top of X-ray photoelectron spectra of valence band in comparison with those for undoped TiO2 are described.
Simulation of the Motion of Magnetic Nanoparticles in Human Tissues
Authors: Andriushenko Peter , Afremov Leonid L. , Chernova Maria
Published: April 2014

In this paper an attempt on the basis of the theory of mobile cellular automata to develop a model of motion of magnetic nanoparticles in human organs and tissues. In the framework of the method of movable cellular automata, the simulated system (tissues and organs) is represented by an assembly of interacting automata (elements of finite size). The concept of the method is based on the introduction of a new state type – the state of a pair of automata. Setting various parameters of the medium (tissues and organs). We can vary behavior of these particles in these mediums.
Nanostructured Magnetoimpedance Multilayers with Different Thickness of FeNi Components
Authors: Chlenova Anna A. , Kurlyandskaya Galina V. , Volchkov Stanislav O. , Lepalovskij Vladimir N. , El Kammouni Rhimou
Published: April 2014

Magnetic properties and magnetoimpedance of [FeNi/Cu]n/FeNi/Cu (500 nm)/[FeNi/Cu]m/FeNi MI asymmetric and symmetric structures were studied for multilayeres with different thickness (25, 50 or 170 nm) of permalloy layers. The asymmetric structures in the case of FeNi layers of 50 nm show higher sensitivities comparing with symmetric structures. Asymmetric multilayered structures with 25 nm thick FeNi layers are an interesting subject for further investigation as the interactions between FeNi layers seem to be providing the best MI response.
Statistical and Multifractal Properties of Barkhausen Jumps in Exchange-Coupled Antiferromagnetic/Ferromagnetic Bilayers
Authors: Shashkov Ivan V. , Lebyodkin Mikhail A. , Gornakov Vladimir S.
Published: April 2014

Statistical and multifractal properties of Barkhausen jumps in exchange-coupled ferromagnet/antiferromagnet bilayers are studied on Co/IrMn and NiFe/NiO heterostructures using a magneto-optical indicator film technique. The statistical analysis proves a nonstochastic character of magnetization jumps. In particular, power-law behavior is observed for Co/IrMn samples. Furthermore, the statistics depends on the ferromagnet layer thickness and antiferromagnet layer material structure. The average jump size displays an asymmetry between the forward and backward branches of the hysteresis loop, particularly pronounced for the structure with a thin Co layer. In spite of the observation of such an asymmetry in the activity of the domain nucleation and pinning centers, the statistical distributions of jumps do not show any significant differences for two branches of the hysteresis loop. The conclusion on a nonrandom character of the magnetization process is supported by the multifractal analysis which reveals the presence of correlations in the time arrangement of the Barkhausen jumps.
Features of Magnetic, Magnetoelectric and Magnetoelastic Properties of HoAl3(BO3)4
Authors: Begunov A.I. , Demidov A.A. , Gudim I.A. , Eremin Evgeniy V.
Published: April 2014

The main features of the magnetic, magnetoelastic and record magnetoelectric properties of a HoAl3(BO3)4 alumoborate single crystal have been studied experimentally and theoretically. ForB||awe have observed a giant polarization ΔPba(Ba) ≈ –5240 µС/m2 induced by field of 9 T at T = 5 K. We have calculated the magnetic characteristics of HoAl3(BO3)4 in the framework of a crystal-field model. The parameters of the crystal-field in HoAl3(BO3)4 have been determined. Good agreement of experimental and calculational magnetization curves Mc,^с(В) and the temperature dependences of magnetization Mс,^с(T) was achieved. For interpretation of magnetostriction in HoAl3(BO3)4 the field and temperature dependences of the multipole moments have been calculated.
Interface Structure and Magnetoresistance Studies of [Co/C]n Superlattices by Means of NMR and TEM
Authors: Chuprakov Stanislav A. , Krinitsina Tatiana P. , Bannikova Natalia S. , Blinov Iliya V. , Verkhovskii Stanislav V. , Milyaev Michail A. , Popov Vladimir V. , Ustinov Vladimir V.
Published: April 2014

Structural features of interfaces in [Co/Cu]n superlattices obtained by magnetron sputtering have been studied by nuclear magnetic resonance (NMR). Modification of interface structural characteristics and magnetoresistive properties of the superlattices with the increase of the number of [Co/C] bilayers is analyzed. Correlation between magnetoresistance and interface structural characteristics has been revealed.
Magnetization Dynamics and Electron Transport in the La0.7Sr0.3MnO3/Y3Fe5O12 Hybrid Structures
Authors: Volkov Nikita V. , Smolyakov Dmitry A. , Rautskii Mikhail V. , Chichkov Vladimir I. , Mukovskii Yakov M.
Published: April 2014

We present the results of investigations of the spin-polarized current and spin dynamics in the hybrid structures ferrimagnetic insulator/ferromagnetic metal subjected to microwave radiation. We studied the La0.7Sr0.3MnO3/Y3Fe5O12 bilayer films on the Gd3Ga5O12 substrate. It was experimentally established that under the action of spin pumping the resistance of the La0.7Sr0.3MnO3 film changes. The value of ΔR is maximum in the sample with a La0.7Sr0.3MnO3 layer thickness of 10 nm and sharply drops as the manganite film thickness is increased. The resistance decreases in the paramagnetic region and grows in the ferromagnetic region at temperatures below the metal-insulator transition point. The variation in the resistance of the manganite film can be attributed to the correlation of the spin dynamics and transport properties of conduction electrons in the structure.
Investigation of Evolution of Domain Structure in Iron Garnet Tb0.26Y2.74Fe5O12
Authors: Niyazov L.N. , Djuraev Davron R.
Published: April 2014

The technical magnetization and the domain structure of a Tb0.26Y2.74Fe5O12 single crystal have been studied in the temperature region of a spontaneous spin-flip phase transition (SFPT) by magneto-optical method. It has been found that the character of evolution of domain configuration in a SFPT depends from mechanical stresses in crystal.
Electronic Structure of Nonstoichiometric LaMnO3-x Calculated in the Coherent Potential Approximation
Authors: Korotin Mikhail A. , Skorikov Nikolay A. , Anisimov Vladimir I.
Published: April 2014

A method for electronic structure calculations of strongly correlated materials based on the coherent potential approximation is formulated and implemented. The evolution of the electronic structure of the LaMnO perovskite system in dependence on oxygen deficiency is studied.
X-Ray and Magnetic Measurements of TmFeTi2O7
Authors: Drokina Tamara V. , Petrakovskii German A. , Velikanov Dmitrii A. , Molokeev Maksim S.
Published: April 2014

In this paper we are reported about a peculiarity of the crystal structure and the magnetic state of TmFeTi2O7. The compound TmFeTi2O7 has been synthesizedusing the solid-phase reaction method. Using X-ray diffraction method the disorder in the distribution of the iron ions over five nonequivalent crystal sites was observed, also the populations of the iron atoms positions were determined. We show that below Tf = 6 K the magnetization of TmFeTi2O7 depends on the magnetic history of the sample. There are indications for spin glass state. This results allow us to assume the state of spin glass is realized below freezing temperature Tf = 6 K in TmFeTi2O7.
Electrical and Dielectrical Propeties of Gas-Sensor Resistive Type Bi2Sn2O7
Authors: Udod Lubov V. , Sitnikov Maxim N. , Aplesnin Sergei S. , Molokeev Maxim S.
Published: April 2014

Polycrystalline samples of Bi2Sn2O7 have been synthesized by conventional solid-state reaction method. According to the X-ray powder diffraction research, our sample co-existing of two polymorphs phases: cubic and rhombic, concurrently. The real dielectric permeability Re (ε) monotonic grows versus temperature and the imaginary dielectric permeability Im (ε) nonmonotonic is increased at the heating. There are maxima at Т=450 K on both temperature dependences Im (ε) and Re (ε) reveal. Anomalies in the temperature dependence of electrical resistivity at temperatures are found and to be correlated with the α→ β structural phase transition temperature.
Phase Transitions between Magnetic Incommensurate States of Terbium Manganite in Magnetic Field
Authors: Chupis Irina E. , Kovtun Helen A.
Published: April 2014

Phase transitions between incommensurate spin states in ferroelectromagnet TbMnO3 in magnetic field along the modulation vector are phenomenologically analyzed. It is shown that the competition between different terms of the fourth order in magnetic anisotropy energy is a reason of the reorientation of spin-cycloid plane and electric polarization by 900 (polarization flop). Calculated phase diagram is in a good agreement with experimental data.
Upper Critical Field in Electron-Doped Superconductor with Nonstoichiometric Disorder near Antiferromagnetic-Superconducting Phase Boundary
Authors: Charikova Tatiana B. , Shelushinina Nina G. , Harus German I. , Petukhov Denis S. , Ivanov Andrei A.
Published: April 2014

Using the resistivity method it was found that temperature dependence of the upper critical field for underdoped Nd1.86Ce0.14CuO4+δ have an anomalous upward curvature of Hc2(T) dependence and can be consistently explained by the two-band/two-gap model of a dirty superconductor. Near antiferromagnetic-superconducting phase boundary the critical temperature remains constant with the change of the disorder parameter and the slope of Bc2 increases with increasing of the disorder parameter. This behavior is completely different from dependencies for pure superconducting phase at optimal doping region. This difference may indicate the change of the type of the paring: from the predominance of the anisotropic s-wave component (may be due to unstable competition between antiferromagnetic (AF) and superconducting (SC) regions) in underdoped (x=0.14) region to the prevalence of d-wave part in optimal doped regions (x=0.15) because of residual spin fluctuations.
Tissue-Resident Exhausted Effector Memory CD8+ T Cells Accumulate in the Retina during Chronic Experimental Autoimmune Uveoretinitis
Authors: Boldison Joanne , Chu Colin J. , Copland David A. , Lait Philippa J. P. , Khera Tarnjit K. , Dick Andrew D. , Nicholson Lindsay B.
Published: April 2014

Experimental autoimmune uveoretinitis is a model for noninfectious posterior segment intraocular inflammation in humans. Although this disease is CD4+ T cell dependent, in the persistent phase of disease CD8+ T cells accumulate. We show that these are effector memory CD8+ T cells that differ from their splenic counterparts with respect to surface expression of CD69, CD103, and Ly6C. These retinal effector memory CD8+ T cells have limited cytotoxic effector function, are impaired in their ability to proliferate in response to Ag-specific stimulation, and upregulate programmed death 1 receptor. Treatment with fingolimod (FTY720) during the late phase of disease revealed that retinal CD8+ T cells were tissue resident. Despite signs of exhaustion, these cells were functional, as their depletion resulted in an expansion of retinal CD4+ T cells and CD11b+ macrophages. These results demonstrate that, during chronic autoimmune inflammation, exhausted CD8+ T cells become established in the local tissue. They are phenotypically distinct from peripheral CD8+ T cells and provide local signals within the tissue by expression of inhibitory receptors such as programmed death 1 that limit persistent inflammation.
Release of Cystic Fibrosis Airway Inflammatory Markers from Pseudomonas aeruginosa–Stimulated Human Neutrophils Involves NADPH Oxidase-Dependent Extracellular DNA Trap Formation
Authors: Yoo Dae-goon , Winn Matthew , Pang Lan , Moskowitz Samuel M. , Malech Harry L. , Leto Thomas L. , Rada Balázs
Published: April 2014

Cystic fibrosis (CF) airways are characterized by bacterial infections, excess mucus production, and robust neutrophil recruitment. The main CF airway pathogen is Pseudomonas aeruginosa. Neutrophils are not capable of clearing the infection. Neutrophil primary granule components, myeloperoxidase (MPO) and human neutrophil elastase (HNE), are inflammatory markers in CF airways, and their increased levels are associated with poor lung function. Identifying the mechanism of MPO and HNE release from neutrophils is of high clinical relevance for CF. In this article, we show that human neutrophils release large amounts of neutrophil extracellular traps (NETs) in the presence of P. aeruginosa. Bacteria are entangled in NETs and colocalize with extracellular DNA. MPO, HNE, and citrullinated histone H4 are all associated with DNA in Pseudomonas-triggered NETs. Both laboratory standard strains and CF isolates of P. aeruginosa induce DNA, MPO, and HNE release from human neutrophils. The increase in peroxidase activity of neutrophil supernatants after Pseudomonas exposure indicates that enzymatically active MPO is released. P. aeruginosa induces a robust respiratory burst in neutrophils that is required for extracellular DNA release. Inhibition of the cytoskeleton prevents Pseudomonas-initiated superoxide production and DNA release. NADPH oxidase inhibition suppresses Pseudomonas-induced release of active MPO and HNE. Blocking MEK/ERK signaling results in only minimal inhibition of DNA release induced by Pseudomonas. Our data describe in vitro details of DNA, MPO, and HNE release from neutrophils activated by P. aeruginosa. We propose that Pseudomonas-induced NET formation is an important mechanism contributing to inflammatory conditions characteristic of CF airways.
Functional Avidity and IL-2/Perforin Production Is Linked to the Emergence of Mutations within HLA-B*5701–Restricted Epitopes and HIV-1 Disease Progression
Authors: Buggert Marcus , Norström Melissa M. , Salemi Marco , Hecht Frederick M. , Karlsson Annika C.
Published: April 2014

Viral escape from HIV-1–specific CD8+ T cells has been demonstrated in numerous studies previously. However, the qualitative features driving the emergence of mutations within epitopes are still unclear. In this study, we aimed to distinguish whether specific functional characteristics of HLA-B*5701–restricted CD8+ T cells influence the emergence of mutations in high-risk progressors (HRPs) versus low-risk progressors (LRPs). Single-genome sequencing was performed to detect viral mutations (variants) within seven HLA-B*5701–restricted epitopes in Gag (n = 4) and Nef (n = 3) in six untreated HLA-B*5701 subjects followed from early infection up to 7 y. Several well-characterized effector markers (IFN-γ, IL-2, MIP-1β, TNF, CD107a, and perforin) were identified by flow cytometry following autologous (initial and emerging variant/s) epitope stimulations. This study demonstrates that specific functional attributes may facilitate the outgrowth of mutations within HLA-B*5701–restricted epitopes. A significantly lower fraction of IL-2–producing cells and a decrease in functional avidity and polyfunctional sensitivity were evident in emerging epitope variants compared with the initial autologous epitopes. Interestingly, the HRPs mainly drove these differences, whereas the LRPs maintained a directed and maintained functional response against emerging epitope variants. In addition, LRPs induced improved cell-cycle progression and perforin upregulation after autologous and emerging epitope variant stimulations in contrast to HRPs. The maintained quantitative and qualitative features of the CD8+ T cell responses in LRPs toward emerging epitope variants provide insights into why HLA-B*5701 subjects have different risks of HIV-1 disease progression.
TLR3–Responsive, XCR1+, CD141(BDCA-3)+/CD8α+-Equivalent Dendritic Cells Uncovered in Healthy and Simian Immunodeficiency Virus–Infected Rhesus Macaques
Authors: Dutertre Charles-Antoine , Jourdain Jean-Pierre , Rancez Magali , Amraoui Sonia , Fossum Even , Bogen Bjarne , Sanchez Cindy , Couëdel-Courteille Anne , Richard Yolande , Dalod Marc , Feuillet Vincent , Cheynier Rémi , Hosmalin Anne
Published: April 2014

In mice, CD8α+ myeloid dendritic cells (mDC) optimally cross-present Ags to CD8+ T cells and respond strongly to TLR3 ligands. Although equivalent DC have been identified by comparative genomic analysis and functional studies in humans as XCR1+CD141 (BDCA-3)+Clec9A+cell adhesion molecule 1+ mDC, and in sheep as CD26+ mDC, these cells remained elusive in nonhuman primates. To remedy this situation, we delineated precisely DC and monocyte populations by 12-color flow cytometry and transcriptomic analyses in healthy rhesus macaques. We identified a new mDC population, with strong phenotypic and transcriptional homology to human CD141+ and murine CD8α+ mDC, including XCR1 membrane expression as a conserved specific marker. In contrast, high CD11c expression was not characteristic of mDC in macaques, but of CD16+ monocytes. Like their human and murine homologs, simian XCR1+ mDC had much stronger responses to TLR3 stimulation than other myeloid cells. The importance of this new mDC population was tested in SIVmac251 infection, the most relevant animal model for pathogenic HIV-1 infection and vaccination. This population increased sharply and transiently during acute infection, but was reduced in blood and spleen during advanced disease. The identification of XCR1+ mDC in rhesus macaques opens new avenues for future preclinical vaccinal studies and highlights XCR1 as a prime candidate for targeted vaccine delivery.
Cutting Edge: NKG2ChiCD57+ NK Cells Respond Specifically to Acute Infection with Cytomegalovirus and Not Epstein–Barr Virus
Authors: Hendricks Deborah W. , Balfour Henry H. , Dunmire Samantha K. , Schmeling David O. , Hogquist Kristin A. , Lanier Lewis L.
Published: April 2014

CMV induces the expansion of a unique subset of human NK cells expressing high levels of the activating CD94-NKG2C receptor that persist after control of the infection. We investigated whether this subset is CMV specific or is also responsive to acute infection with EBV. We describe a longitudinal study of CMV− and CMV+ students who were acutely infected with EBV. The NKG2Chi NK subset was not expanded by EBV infection. However, EBV infection caused a decrease in the absolute number of immature CD56brightCD16− NK cells in the blood and, in CMV+ individuals, induced an increased frequency of mature CD56dimNKG2A+CD57+ NK cells in the blood that persisted into latency. These results provide further evidence that NKG2C+ NK cells are CMV specific and suggest that EBV infection alters the repertoire of NK cells in the blood.
Protection from Intestinal Inflammation by Bacterial Exopolysaccharides
Authors: Jones Sara E. , Paynich Mallory L. , Kearns Daniel B. , Knight Katherine L.
Published: April 2014

Host inflammatory responses against pathogenic organisms can be abrogated by commensals; however, the molecular mechanisms by which pathogenesis is prevented are still poorly understood. Previous studies demonstrated that administration of a single dose of Bacillus subtilis prevented disease and inflammation by the enteric mouse pathogen Citrobacter rodentium, which causes disease similar to the human pathogen enteropathogenic Escherichia coli. No protection was observed when an exopolysaccharide (EPS)-deficient mutant of B. subtilis was used, suggesting that EPS are the protective factor. In this study, we isolated and characterized EPS and showed that they also prevent C. rodentium–associated intestinal disease after a single injection. Protection is TLR4 dependent because EPS-treated TLR4 knockout mice developed disease. Furthermore, protection could be conveyed to wild-type mice by adoptive transfer of macrophage-rich peritoneal cells from EPS-treated mice. We found that EPS specifically bind peritoneal macrophages, and because mice lacking MyD88 signaling in myeloid cells were not protected by EPS, we conclude that bacterial EPS prevent colitis in a TLR4-dependent manner that requires myeloid cells. These studies provide a simple means of preventing intestinal inflammation caused by enteric pathogens.
Cutting Edge: Salivary Gland NK Cells Develop Independently of Nfil3 in Steady-State
Authors: Cortez Victor S. , Fuchs Anja , Cella Marina , Gilfillan Susan , Colonna Marco
Published: April 2014

Nfil3 is viewed as an obligate transcription factor for NK cell development. However, mouse CMV (MCMV) infection recently was shown to bypass the requirement for Nfil3 by inducing the appearance of NK cells that express the MCMV-specific receptor Ly49H. Thus, signals transmitted by Ly49H and proinflammatory cytokines are sufficient to promote NK cell differentiation in the absence of Nfil3. In this study, we report that salivary gland (SG) NK cells develop in an Nfil3-independent fashion in the steady-state in the absence of MCMV or any infection. Moreover, we show that SG NK cells have an integrin profile reminiscent of tissue-resident lymphocytes and express TRAIL for killing target cells. These results demonstrate that SG NK cells, although related to conventional NK cells, are a distinct subset of innate lymphoid cells that deviates from the conventional developmental pathway, perhaps under the influence of tissue-specific factors.