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Sample records for randomly oriented grain

  1. Grain orientation, deformation microstructure and flow stress

    International Nuclear Information System (INIS)

    Hansen, N.; Huang, X.; Winther, G.

    2008-01-01

    Dislocation structures in deformed metals have been analyzed quantitatively by transmission electron microscopy, high-resolution electron microscopy and Kikuchi line analysis. A general pattern for the microstructural evolution with increasing strain has been established and structural parameters have been defined and quantified. It has been found that two dislocation patterns co-exist in all grains, however, with very different characteristics dependent on grain orientation. This correlation with the grain orientation has been applied in modeling of the tensile flow stress and the flow stress anisotropy of fcc polycrystals. In conclusion some future research areas are briefly outlined

  2. Randomly grain growth in metallic materials

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, A. [Instituto Politecnico Nacional, (SEPI-ESIME), Unidad Profesional Ticoman, Av. Ticoman 600, Del. G.A.M., C.P. 07340 Distrito Federal, Mexico (Mexico); Instituto Politecnico Nacional, (SEPI-ESIQIE), Unidad Profesional Zacatenco, Edif. 6 y Edif. Z planta baja C.P.07300, Distrito Federal, Mexico (Mexico)], E-mail: adaramil@yahoo.com.mx; Chavez, F. [Instituto Politecnico Nacional, (SEPI-ESIQIE), Unidad Profesional Zacatenco, Edif. 6 y Edif. Z planta baja C.P.07300, Distrito Federal, Mexico (Mexico); Demedices, L. [Instituto Politecnico Nacional, (SEPI-ESIME), Unidad Profesional Ticoman, Av. Ticoman 600, Del. G.A.M., C.P. 07340 Distrito Federal, Mexico (Mexico); Instituto Politecnico Nacional, (SEPI-ESIQIE), Unidad Profesional Zacatenco, Edif. 6 y Edif. Z planta baja C.P.07300, Distrito Federal, Mexico (Mexico); Cruz, A.; Macias, M. [Instituto Politecnico Nacional, (SEPI-ESIQIE), Unidad Profesional Zacatenco, Edif. 6 y Edif. Z planta baja C.P.07300, Distrito Federal, Mexico (Mexico)

    2009-10-30

    Computational modeling of grain structures is a very important topic in materials science. In this work, the development of the computational algorithms for a mathematical model to predict grain nucleation and grain growth is presented. The model place a number of nucleated points randomly in a liquid pool according with the solid and liquid fractions (X{sub sol} and X{sub liq}) of metal solute and the local temperature distribution (SS{sub I,J}). Then these points grows isotropically until obtain a grain structure with straight interfaces. Different grain morphologies such as columnar and equiaxed can be obtained as a function of the temperature distributions and growth directions.

  3. Randomly grain growth in metallic materials

    International Nuclear Information System (INIS)

    Ramirez, A.; Chavez, F.; Demedices, L.; Cruz, A.; Macias, M.

    2009-01-01

    Computational modeling of grain structures is a very important topic in materials science. In this work, the development of the computational algorithms for a mathematical model to predict grain nucleation and grain growth is presented. The model place a number of nucleated points randomly in a liquid pool according with the solid and liquid fractions (X sol and X liq ) of metal solute and the local temperature distribution (SS I,J ). Then these points grows isotropically until obtain a grain structure with straight interfaces. Different grain morphologies such as columnar and equiaxed can be obtained as a function of the temperature distributions and growth directions.

  4. Observation of changing crystal orientations during grain coarsening

    International Nuclear Information System (INIS)

    Sharma, Hemant; Huizenga, Richard M.; Bytchkov, Aleksei; Sietsma, Jilt; Offerman, S. Erik

    2012-01-01

    Understanding the underlying mechanisms of grain coarsening is important in controlling the properties of metals, which strongly depend on the microstructure that forms during the production process or during use at high temperature. Grain coarsening of austenite at 1273 K in a binary Fe–2 wt.% Mn alloy was studied using synchrotron radiation. Evolution of the volume, average crystallographic orientation and mosaicity of more than 2000 individual austenite grains was tracked during annealing. It was found that an approximately linear relationship exists between grain size and mosaicity, which means that orientation gradients are present in the grains. The orientation gradients remain constant during coarsening and consequently the character of grain boundaries changes during coarsening, affecting the coarsening rate. Furthermore, changes in the average orientation of grains during coarsening were observed. The changes could be understood by taking the observed orientation gradients and anisotropic movement of grain boundaries into account. Five basic modes of grain coarsening were deduced from the measurements, which include: anisotropic (I) and isotropic (II) growth (or shrinkage); movement of grain boundaries resulting in no change in volume but a change in shape (III); movement of grain boundaries resulting in no change in volume and mosaicity, but a change in crystallographic orientation (IV); no movement of grain boundaries (V).

  5. Evolution of orientations and deformation structures within individual grains in cold rolled columnar grained nickel

    DEFF Research Database (Denmark)

    Wu, G.L.; Godfrey, A.; Winther, Grethe

    2011-01-01

    Columnar grained Ni is used as a model material allowing simultaneous non-surface investigations of the evolution of crystallographic orientations and deformation microstructures within individual grains as a function of rolling strain up to ε=0.7. Electron channelling contrast and electron...... backscattered diffraction are used to visualise microstructures and crystallographic orientations. It is found that both the microstructural and the textural development depend strongly on the initial grain orientation. A grain size effect is observed on the deformation-induced orientation scatter within...

  6. Grain Orientation and Interface Character Distribution During Austenite Precipitation Phase in Duplex Stainless Steel

    Directory of Open Access Journals (Sweden)

    XU Ting

    2018-02-01

    Full Text Available The grain orientation and the interface character distribution were investigated for γ precipitation from the supersaturated α during aging at 1323K in duplex stainless steel by using EBSD technique and misorientation analysis based on Rodrigues-Frank (R-F space. The results show that sharp texture and the grain boundary character distribution featured by a high population of low angle grain boundary (LAB and a small number of twin boundaries (TBs are produced in the γ precipitated from cold-rolled supersaturated coarse α with pre-strain of ε=2. The precipitated γ grains approximately possess K-S, N-W and Bain orientation relationship with the α matrix equally. For the unstrained α matrix of the same orientation, nearly random texture and the grain boundary character predominated by TBs are introduced in the γ precipitation after aging. Most of γ have K-S relation with the α matrix. However, twining in γ leads to the deviation from typical K-S orientation relationship. And also, one-fourth of phase boundaries along γ grains containing twins are found to obey a new orientation relationship of 35°/〈110〉 with α matrix.

  7. Coincidence orientations of grains in hexagonal materials

    International Nuclear Information System (INIS)

    Grimmer, H.; Warrington, D.H.

    1986-06-01

    The connection between the rotation matrix in hexagonal lattice coordinates and an angle-axis quadruple is given. The multiplication law of quadruples is derived. It corresponds to multiplying two matrices and gives the effect of two successive rotations. The relation is given between two quadruples that describe the same relative orientation of two lattices due to their hexagonal symmetry; a unique standard description of the relative orientation is proposed. The restrictions satisfied by rotations generating coincidence site lattices (CSLs) are derived for any value of the axial ratio rho = c/a. It is shown that the law for cubic lattices, where the multiplicity SIGMA of the CSL was equal to the least common denominator of the elements of the rotation matrix, does not always hold for hexagonal lattices. A generalisation of this law to lattices of arbitrary symmetry is given and another, quicker method to determine SIGMA for hexagonal lattices is derived. Finally, convenient algorithms are described for determining bases of the CSL and the DSC lattice. (author)

  8. Processing, microstructure and properties of grain-oriented ferroelectric ceramics

    International Nuclear Information System (INIS)

    Okazaki, K.; Igarashi, H.; Nagata, K.; Yamamoto, T.; Tashiro, S.

    1986-01-01

    Grain oriented ferroelectric ceramics such as PbBi/sub 2/Nb/sub 2/O/sub 9/, bismuth compound with layer structure, (PbLa)Nb/sub 2/O/sub 6/, tungsten-bronze structure and SbSI were prepared by an uni-axial hot-pressing, a double-stage hot-pressing and tape casting methods. Microstructures of them were examined by SEM and the prefered textures of the ceramics composed of thin plate and/or needle crystallites were ascertained. Grain orientation effects on electrical, piezoelectric, optical and mechanical properties are discussed

  9. Mechanism of secondary recrystallization of Goss grains in grain-oriented electrical steel

    Science.gov (United States)

    Hayakawa, Yasuyuki

    2017-12-01

    Since its invention by Goss in 1934, grain-oriented (GO) electrical steel has been widely used as a core material in transformers. GO exhibits a grain size of over several millimeters attained by secondary recrystallization during high-temperature final batch annealing. In addition to the unusually large grain size, the crystal direction in the rolling direction is aligned with , which is the easy magnetization axis of α-iron. Secondary recrystallization is the phenomenon in which a certain very small number of {110} (Goss) grains grow selectively (about one in 106 primary grains) at the expense of many other primary recrystallized grains. The question of why the Goss orientation is exclusively selected during secondary recrystallization has long been a main research subject in this field. The general criterion for secondary recrystallization is a small and uniform primary grain size, which is achieved through the inhibition of normal grain growth by fine precipitates called inhibitors. This paper describes several conceivable mechanisms of secondary recrystallization of Goss grains mainly based on the selective growth model.

  10. Anisotropy model for modern grain oriented electrical steel based on orientation distribution function

    Directory of Open Access Journals (Sweden)

    Fan Jiang

    2018-05-01

    Full Text Available Accurately modeling the anisotropic behavior of electrical steel is mandatory in order to perform good end simulations. Several approaches can be found in the literature for that purpose but the more often those methods are not able to deal with grain oriented electrical steel. In this paper, a method based on orientation distribution function is applied to modern grain oriented laminations. In particular, two solutions are proposed in order to increase the results accuracy. The first one consists in increasing the decomposition number of the cosine series on which the method is based. The second one consists in modifying the determination method of the terms belonging to this cosine series.

  11. Origin of grain orientation during solidification of an aluminum alloy

    International Nuclear Information System (INIS)

    Wei, H.L.; Elmer, J.W.; DebRoy, T.

    2016-01-01

    The evolution of grain morphology during solidification of a moving aluminum alloy pool is simulated by considering heat transfer, flow of liquid metal in the molten pool and solidification parameters. The computationally efficient model consists of a 3D coupled heat transfer and fluid flow simulation to predict the molten pool shape and temperature field, and a 2D model of grain formation in the molten pool. The results demonstrate that columnar grains grow in a curved pattern rather than along straight lines from the fusion boundary towards the center of the molten pool. The calculated results are validated with independent experimental data. The computed ratio of local temperature gradient to solidification rate, G/R, is used to model the columnar to equiaxed transition during solidification. The simulated results show that only curved columnar grains are formed when the scanning speed is low (2.0 mm/s). In contrast, a transition from curved columnar to equiaxed morphologies occurs at the higher scanning speeds of 8.0 mm/s and 11.5 mm/s, with higher equiaxed grain fraction at higher speed. The similarities between the physical processes governing fusion welding and additive manufacturing (AM) make the model capable of predicting grain orientation in both processes.

  12. Correlation between grain orientation and the shade of color etching

    International Nuclear Information System (INIS)

    Szabo, Peter J.; Kardos, I.

    2010-01-01

    Color etching is an extremely effective metallographic technique not only for making grains well visible, but also for making them distinguishable for automated image analyzers. During color etching, a thin film is formed on the surface of the specimen. The thickness of this layer is in the order of magnitude of the visible light and since both the metal-film boundary and the film surface reflect light, an interference occurs. A wavelength-component of the white line is eliminated and its complementary color will be seen on the surface. As the thickness changes, the colors also change grain by grain. The thickness of the film is dependent on several factors, mostly on the type of the phase. However, different color shades can be observed on the surfaces of single phase materials, which phenomenon is caused by the different crystallographic orientations of the grains. This paper shows a combined color etching electron backscatter diffraction (EBSD) investigation of cast iron. An area of the surface of a gray cast iron specimen was etched. Colors were characterized by their luminescence and their red, green and blue intensity. An EBSD orientation map was taken from the same area and the orientations of the individual grains were determined. Results showed that a strong correlation was found between the luminescence and the R, G, B intensity of the color and the angle between the specimen normal and the direction, while such correlation was not observed between the color parameters and the and directions, respectively. This indicates that film thickness is sensitive to the direction of the crystal.

  13. Microstructure-grain orientation relationship in coarse grain nickel cold-rolled to large strain

    International Nuclear Information System (INIS)

    Chen, H.S.; Godfrey, A.; Hansen, N.; Xie, J.X.; Liu, Q.

    2008-01-01

    The relationship between crystallographic orientation and the deformation microstructure formed during cold-rolling to high strains (up to ε vM = 4.5) has been investigated. The starting material was Ni (99.96% purity) with a coarse initial average grain size (approximately 500 μm). Microstructural characterization was carried out using a combination of electron channeling contrast imaging and electron back-scatter diffraction orientation mapping. An orientation dependence of the deformation microstructure was observed even at the highest strain examined. A large increase in the average boundary misorientation is found at strains above ε vM = 1.8 for regions with the {1 1 2} and {1 2 3} orientations. This increase accompanies the structural transition from a medium strain microstructure to a high strain lamellar microstructure. In contrast, the average misorientation in regions of {1 1 0} orientation increases only slowly even up to the highest strain examined

  14. Interactive contribution of grain size and grain orientation to coercivity of melt spun ribbons

    International Nuclear Information System (INIS)

    Wang, N.; Li, G.; Yao, W.J.; Wen, X.X.

    2010-01-01

    During melt spinning process, the improvement of certain grain orientation and the refinement of grain size with surface velocity have interactive and contradictory effects on the magnetic properties. The contributions of these effects have seldom been taken into account and they were discussed in this paper via Fe-2, 4, 6.5 wt% Si alloys. Heat treatment at 1173 K for 1 h was performed to show the annealing impact. The X-ray diffraction patterns show that the high surface velocity and heat treatment increase the intensity ratio of line (2 0 0) to (1 1 0) of A2 phase. The (2 0 0) line corresponds to (2 0 0) plane in direction, easy magnetization direction of α-Fe phase in Fe-Si alloy. The improvement of this grain orientation with the surface velocity decreases the coercivity, which should increase due to the grain refinement. It is revealed that the texture promoted by the anisotropic heat release during melt spinning process is one factor to improve the magnetic properties and should be considered when preparing soft magnetic materials.

  15. Random walks of oriented particles on fractals

    International Nuclear Information System (INIS)

    Haber, René; Prehl, Janett; Hoffmann, Karl Heinz; Herrmann, Heiko

    2014-01-01

    Random walks of point particles on fractals exhibit subdiffusive behavior, where the anomalous diffusion exponent is smaller than one, and the corresponding random walk dimension is larger than two. This is due to the limited space available in fractal structures. Here, we endow the particles with an orientation and analyze their dynamics on fractal structures. In particular, we focus on the dynamical consequences of the interactions between the local surrounding fractal structure and the particle orientation, which are modeled using an appropriate move class. These interactions can lead to particles becoming temporarily or permanently stuck in parts of the structure. A surprising finding is that the random walk dimension is not affected by the orientation while the diffusion constant shows a variety of interesting and surprising features. (paper)

  16. Effects of Cold Rolling Reduction and Initial Goss Grains Orientation on Texture Evolution and Magnetic Performance of Ultra-thin Grain-oriented Silicon Steel

    Directory of Open Access Journals (Sweden)

    LIANG Rui-yang

    2017-06-01

    Full Text Available The ultra-thin grain-oriented silicon steel strips with a thickness of 0.06-0.12mm were produced by one-step-rolling methods with different Goss-orientation of grain-oriented silicon steel sheets. The effect of cold rolling reduction and initial Goss-orientation of samples on texture evolution and magnetic performance of ultra-thin grain-oriented silicon steel strips was studied by EBSD. The result shows that with the increase of cold rolling reduction and decrease of strips thickness, the recrystallization texture is enhanced after annealing.When the cold rolling reduction is 70%,RD//〈001〉 recrystallization texture is the sharpest, and the magnetic performance is the best. The higher degree of Goss orientation in initial sample is, the better magnetic performance of ultra-thin grain-oriented silicon steel.Therefore, for producing an ultra-thin grain-oriented silicon steel with high performance, a material with a concentrated orientation of Goss grains can be used.

  17. Comparison of grain to grain orientation and stiffness mapping by spatially resolved acoustic spectroscopy and EBSD.

    Science.gov (United States)

    Mark, A F; Li, W; Sharples, S; Withers, P J

    2017-07-01

    Our aim was to establish the capability of spatially resolved acoustic spectroscopy (SRAS) to map grain orientations and the anisotropy in stiffness at the sub-mm to micron scale by comparing the method with electron backscatter diffraction (EBSD) undertaken within a scanning electron microscope. In the former the grain orientations are deduced by measuring the spatial variation in elastic modulus; conversely, in EBSD the elastic anisotropy is deduced from direct measurements of the crystal orientations. The two test-cases comprise mapping the fusion zones for large TIG and MMA welds in thick power plant austenitic and ferritic steels, respectively; these are technologically important because, among other things, elastic anisotropy can cause ultrasonic weld inspection methods to become inaccurate because it causes bending in the paths of sound waves. The spatial resolution of SRAS is not as good as that for EBSD (∼100 μm vs. ∼a few nm), nor is the angular resolution (∼1.5° vs. ∼0.5°). However the method can be applied to much larger areas (currently on the order of 300 mm square), is much faster (∼5 times), is cheaper and easier to perform, and it could be undertaken on the manufacturing floor. Given these advantages, particularly to industrial users, and the on-going improvements to the method, SRAS has the potential to become a standard method for orientation mapping, particularly in cases where the elastic anisotropy is important over macroscopic/component length scales. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  18. Simulation of growing grains under orientation relation - dependent quadruple point dragging

    International Nuclear Information System (INIS)

    Ito, K

    2015-01-01

    The growth behaviour of a specified grain embedded in matrix grains, for which the migration mobility of the quadruple points depended on the relation between the orientations of the growing and shrinking grains, was studied using a modified Potts MC-type threedimensional simulation. Large embedded grains continued to grow without being overcome by coarsening matrix grains, whereas small embedded grains disappeared, under the influence of the relative mobilities of the quadruple points, the composition of the matrix grain texture and the width of the grain size distribution of the matrix grains. These results indicate that orientation relation-dependent quadruple point dragging can affect the recrystallization texture during the grain coarsening stage. (paper)

  19. Grain interaction mechanisms leading to intragranular orientation spread in tensile deformed bulk grains of interstitial-free steel

    DEFF Research Database (Denmark)

    Winther, Grethe; Wright, Jonathan P.; Schmidt, Søren

    2017-01-01

    environments representing the bulk texture, yet their deformation-induced rotations are very different. The ALAMEL model is employed to analyse the grain interaction mechanisms. Predictions of this model qualitatively agree with the directionality and magnitude of the experimental orientation spread. However......, quantitative agreement requires fine-tuning of the boundary conditions. The majority of the modelled slip is accounted for by four slip systems also predicted to be active by the classical Taylor model in uniaxial tension, and most of the orientation spread along the grain boundaries is caused by relative...... variations in the activities of these. Although limited to two grains, the findings prove that shear at the grain boundaries as accounted for by the ALAMEL model is a dominant grain interaction mechanism....

  20. Wetting morphologies on randomly oriented fibers.

    Science.gov (United States)

    Sauret, Alban; Boulogne, François; Soh, Beatrice; Dressaire, Emilie; Stone, Howard A

    2015-06-01

    We characterize the different morphologies adopted by a drop of liquid placed on two randomly oriented fibers, which is a first step toward understanding the wetting of fibrous networks. The present work reviews previous modeling for parallel and touching crossed fibers and extends it to an arbitrary orientation of the fibers characterized by the tilting angle and the minimum spacing distance. Depending on the volume of liquid, the spacing distance between fibers and the angle between the fibers, we highlight that the liquid can adopt three different equilibrium morphologies: 1) a column morphology in which the liquid spreads between the fibers, 2) a mixed morphology where a drop grows at one end of the column or 3) a single drop located at the node. We capture the different morphologies observed using an analytical model that predicts the equilibrium configuration of the liquid based on the geometry of the fibers and the volume of liquid.

  1. Microstructure Control of Barium Titanate Grain-oriented Ceramics and Their Piezoelectric Properties

    International Nuclear Information System (INIS)

    Mori, Rintaro; Nakashima, Koichi; Fujii, Ichiro; Wada, Satoshi; Hayashi, Hiroshi; Nagamori, Yoshitaka; Yamamoto, Yuichi

    2011-01-01

    The Barium titanate (BaTiO 3 , BT) [110] grain-oriented ceramics along [110] direction were prepared by a templated grain growth (TGG) method. The [110] oriented BT platelike particles (t-BT) were used as template particles. The relationship between poling treatment program and piezoelectric constant was investigated. The change in the poling conditions did not greatly influence domain size and the piezoelectric constant. The relationship between piezoelectric properties and domain size in BT grain-oriented ceramics was investigated. The smaller domain size was required to increase the piezoelectric constant.

  2. Influence of crystal orientation on magnetostriction waveform in grain orientated electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Kijima, Gou, E-mail: g-kijima@jfe-steel.co.jp [Steel Research Laboratory, JFE Steel Corporation, Kawasaki, 210-0855 (Japan); Yamaguchi, Hiroi; Senda, Kunihiro; Hayakawa, Yasuyuki [Steel Research Laboratory, JFE Steel Corporation, Kurashiki, 712-8511 (Japan)

    2014-08-01

    Aiming to gain insight into the mechanisms of grain-oriented electrical steel sheet magnetostriction waveforms, we investigated the influence of crystal orientations. An increase in the β angle results in an increase in the amplitude of magnetostriction waveform, but does not affect the waveform itself. By slanting the excitation direction to simulate the change of the α angle, change in the magnetostriction waveform and a constriction–extension transition point in the steel plate was observed. The amplitude, however, was not significantly affected. We explained the nature of constriction–extension transition point in the magnetostriction waveform by considering the magnetization rotation. We speculated that the change of waveform resulting from the increase in the coating tensile stress can be attributed to the phenomenon of the magnetization rotation becoming hard to be generated due to the increase of magnetic anisotropy toward [001] axis. - Highlights: • β angle is related with the amplitude of magnetostriction waveform. • α angle is related with the magnetostriction waveform itself. • The effect of α angle can be controlled by the effect of coating tensile stress.

  3. Characterizing Grain-Oriented Silicon Steel Sheet Using Automated High-Resolution Laue X-ray Diffraction

    Science.gov (United States)

    Lynch, Peter; Barnett, Matthew; Stevenson, Andrew; Hutchinson, Bevis

    2017-11-01

    Controlling texture in grain-oriented (GO) silicon steel sheet is critical for optimization of its magnetization performance. A new automated laboratory system, based on X-ray Laue diffraction, is introduced as a rapid method for large scale grain orientation mapping and texture measurement in these materials. Wide area grain orientation maps are demonstrated for both macroetched and coated GO steel sheets. The large secondary grains contain uniform lattice rotations, the origins of which are discussed.

  4. Effect of crystal orientation on grain boundary migration and radiation-induced segregation

    International Nuclear Information System (INIS)

    Hashimoto, N.; Eda, Y.; Takahashi, H.

    1996-01-01

    Fe-Cr-Ni, Ni-Al and Ni-Si alloys were electron-irradiated using a high voltage electron microscope (1 MeV), and in situ observations of the structural evolution and micro-chemical analysis were carried out. During the irradiation, the grain boundaries in the irradiated region migrated, while no grain boundary migration occurred in the unirradiated area. The occurrence of boundary migration depended on the orientation relationship of the boundary interfaces. Grain boundary migration took place in Fe-Cr-Ni and Ni-Si alloys with large crystal orientation difference between the two grains across a grain boundary. In Ni-Al, however, the grain boundary migration did not occur. The solute segregation was caused at grain boundary under irradiation and this segregation behavior was closely related to solute size, namely the concentrations of undersized Ni and oversized Cr elements in Fe-Cr-Ni alloy increased and reduced at grain boundary, respectively. The same dependence of segregation on the solute size was derived in Ni-Si and Ni-Al alloys, in which Si and Al solutes are undersized and oversized elements, respectively. Therefore, Si solute enriched and Al solute depleted at grain boundary. From the present segregation behavior, it is suggested that the flow of point defects into the boundary is the cause of grain boundary migration. (orig.)

  5. The Role of Grain Orientation and Grain Boundary Characteristics in the Mechanical Twinning Formation in a High Manganese Twinning-Induced Plasticity Steel

    Science.gov (United States)

    Shterner, Vadim; Timokhina, Ilana B.; Rollett, Anthony D.; Beladi, Hossein

    2018-04-01

    In the current study, the dependence of mechanical twinning on grain orientation and grain boundary characteristics was investigated using quasi in-situ tensile testing. The grains of three main orientations (i.e., , , and parallel to the tensile axis (TA)) and certain characteristics of grain boundaries (i.e., the misorientation angle and the inclination angle between the grain boundary plane normal and the TA) were examined. Among the different orientations, and were the most and the least favored orientations for the formation of mechanical twins, respectively. The orientation was intermediate for twinning. The annealing twin boundaries appeared to be the most favorable grain boundaries for the nucleation of mechanical twinning. No dependence was found for the inclination angle of annealing twin boundaries, but the orientation of grains on either side of the annealing twin boundary exhibited a pronounced effect on the propensity for mechanical twinning. Annealing twin boundaries adjacent to high Taylor factor grains exhibited a pronounced tendency for twinning regardless of their inclination angle. In general, grain orientation has a significant influence on twinning on a specific grain boundary.

  6. 2D magnetization of grain-oriented 3%-Si steel under uniaxial stress

    International Nuclear Information System (INIS)

    Permiakov, V.; Dupre, L.; Pulnikov, A.; Melkebeek, J.

    2005-01-01

    Magnetization in electrical steels is strongly affected by mechanical stress. The stress dependence of magnetic properties of non-oriented steels has been studied at one- and two-dimensional magnetization. This paper deals with the stress effect on one- and two-dimensional magnetization in grain-oriented 3%-Si steel. The special magnetic measurements system is applied to combine uniaxial stress and 2D magnetic measurements. The uniaxial stress ranges from 10 MPa compressive stress to 100 MPa tensile stress. A domain theory is a suitable tool for prediction and a physical explanation of stress dependency in grain-oriented steel

  7. Development of microstructure and texture in strip casting grain oriented silicon steel

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yang; Xu, Yun-Bo, E-mail: yunbo_xu@126.com; Zhang, Yuan-Xiang; Fang, Feng; Lu, Xiang; Liu, Hai-Tao; Wang, Guo-Dong

    2015-04-01

    Grain oriented silicon steel was produced by strip casting and two-stage cold rolling processes. The development of microstructure and texture was investigated by using optical microscopy, X-ray diffraction and electron backscattered diffraction. It is shown that the microstructure and texture evolutions of strip casting grain oriented silicon steel are significantly distinct from those in the conventional processing route. The as-cast strip is composed of coarse solidification grains and characterized by pronounced 〈001〉//ND texture together with very weak Goss texture. The initial coarse microstructure enhances {111} shear bands formation during the first cold rolling and then leads to the homogeneously distributed Goss grains through the thickness of intermediate annealed sheet. After the secondary cold rolling and primary annealing, strong γ fiber texture with a peak at {111}〈112〉 dominates the primary recrystallization texture, which is beneficial to the abnormal growth of Goss grain during the subsequent high temperature annealing. Therefore, the secondary recrystallization of Goss orientation evolves completely after the high temperature annealing and the grain oriented silicon steel with a good magnetic properties (B{sub 8}=1.94 T, P{sub 1.7/50}=1.3 W/kg) can be prepared. - Highlights: • Grain oriented silicon steel was developed by a novel ultra-short process. • Many evenly distributed Goss “seeds” were originated from cold rolled shear bands. • More MnS inhibitors were obtained due to the rapid cooling of strip casing. • The magnetic induction of grain oriented silicon steel was significantly improved.

  8. Analysis of Orientation Relations Between Deformed Grains and Recrystallization Nuclei

    DEFF Research Database (Denmark)

    West, Stine S.; Winther, Grethe; Juul Jensen, Dorte

    2011-01-01

    Nucleation in 30 pct rolled high-purity aluminum samples was investigated by the electron backscattering pattern method before and after annealing. A total of 29 nuclei including two twins were observed, and approximately one third of these nuclei had orientations not detected in the deformed state....... Possible orientation relations between these nuclei and the deformed state were by 20 to 55 deg rotation around axes. These axes were compared with the active slip systems, and the crystallographic features of the deformation-induced dislocation boundaries. Good agreement was found between the rotation...

  9. 78 FR 70574 - Grain-Oriented Electrical Steel From China, Czech Republic, Germany, Japan, Korea, Poland, and...

    Science.gov (United States)

    2013-11-26

    ...)] Grain-Oriented Electrical Steel From China, Czech Republic, Germany, Japan, Korea, Poland, and Russia..., Germany, Japan, Korea, Poland, and Russia of grain-oriented electrical steel, provided for in subheadings... alleged to be sold in the United States at less than fair value (LTFV), and by reason of imports of grain...

  10. Secondary recrystallization behavior in a twin-roll cast grain-oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hong-Yu; Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn; Wang, Yin-Ping; Wang, Guo-Dong

    2017-04-15

    The microstructure and texture evolution along the processing was investigated with a particular focus on the secondary recrystallization behavior in a 0.23 mm-thick twin-roll cast grain-oriented electrical steel. A striking feature is that Goss orientation originated during twin-roll casting as a result of shear deformation and it was further enhanced during hot rolling and normalizing. After primary recrystallization annealing, a homogeneous microstructure associated with a sharp γ-fiber texture was produced. During secondary recrystallization annealing, the γ-fiber texture was first strengthened and weakened with increasing temperature prior to the onset of secondary recrystallization. Goss grains always exhibited more 20–45° misoriented boundaries than the matrix. The matrix was quite stable during secondary recrystallization with the aid of dense inhibitors. Finally, a complete secondary recrystallization microstructure consisting of large Goss grains was produced. The grain boundary characteristics distribution indicated that the high energy model was responsible for the abnormal growth of Goss grains under the present conditions. - Highlights: • A 0.23 mm twin-roll cast grain-oriented silicon steel sheet was produced. • Goss orientation originated during twin-roll casting. • Secondary recrystallization behavior was briefly investigated. • γ-fiber texture was enhanced prior to the onset of secondary recrystallization. • A complete secondary recrystallization microstructure was produced.

  11. Behavior of Goss, {411}<148>, and {111}<112> Oriented Grains During Recrystallization and Decarburization After Cold-rolling of Fe-3.1% GrainOriented Electrical Steel

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sung-Ji; Park, No-Jin [Kumoh National Institute of Technology, Gumi (Korea, Republic of); Joo, Hyung-Don; Park, Jong-Tae [POSCO, Pohang (Korea, Republic of)

    2016-07-15

    Grain-oriented electrical steel is used as a core material in transformers and motors. To obtain improved magnetic properties from the grain-oriented electrical steel, the steel should have a strong {110}<001> Goss texture. Recently, controlled manufacturing processes have been employed for developing electrical steels with a strong Goss texture. It is important to carry out research on the {411}<148> and {111}<112> oriented grains in relation to coincidence site lattice (CSL) boundaries, as they have an effect on the easy growth of the Goss grains upon secondary recrystallization. In this study, the behavior of the{411}<148> and {111}<112> oriented grains, which are neighbored with Goss grains after recrystallization with rapid and typical heating rates, and after decarburization, was examined by using x-ray diffraction (XRD) and electron back-scattered diffraction (EBSD) measurements. In the decarburized specimen, the Goss grains encroached the {411}<148> and {111}<112> oriented grains to a greater extent with a rapid heating rate than with a typical heating rate, and larger Goss grains were observed with the rapid heating rate. The {111}<112> oriented grains especially affect the easy growth of the Goss grains, as they are located near the Goss grains. Therefore, larger Goss grains can be produced at rapid heating rates, and the product is estimated to exhibit improved magnetic properties after secondary recrystallization.

  12. Effects of crystallographic orientation vs. grain interaction on slip systems

    DEFF Research Database (Denmark)

    Winther, Grethe

    . Such investigations reveal both similarities and differences. The present contribution gives an overview of a series of investigations, including transmission electron microscopy as well as three-dimensional x-ray diffraction on polycrystalline aluminium deformed to strains of 5-50%. The data are analysed focusing...... on the set of activated slip systems, more precisely whether the observed differences can be attributed to fluctuations in the relative activities of the same set of systems or whether activation of truly different systems is the origin of the variations between and within grains....

  13. Study of secondary recrystallization in grain-oriented steel treated under dynamical heat treatment conditions

    Directory of Open Access Journals (Sweden)

    V. Stoyka

    2009-04-01

    Full Text Available The present study was made to investigate secondary recrystallization in grain-oriented steels annealed at short time temperature exposures with application of dynamical heating. The investigated GO steels for experiments were taken from one industrial line after final cold rolling reduction and subsequent box annealing. It was shown that application of short time heat treatment conditions could lead to complete abnormal grain growth in the investigated GO steel. The texture and microstructure obtained in the laboratory treated material is similar to that observed in the same GO steel taken after industrial final box-annealing. However, some “parasitic” grains were observed in the secondary recrystallized matrix of the laboratory treated GO steel. These “parasitic” grains possess the unwanted from magnetic properties point of view {111} orientation components.

  14. Spatially resolved acoustic spectroscopy for rapid imaging of material microstructure and grain orientation

    International Nuclear Information System (INIS)

    Smith, Richard J; Li, Wenqi; Coulson, Jethro; Clark, Matt; Somekh, Michael G; Sharples, Steve D

    2014-01-01

    Measuring the grain structure of aerospace materials is very important to understand their mechanical properties and in-service performance. Spatially resolved acoustic spectroscopy is an acoustic technique utilizing surface acoustic waves to map the grain structure of a material. When combined with measurements in multiple acoustic propagation directions, the grain orientation can be obtained by fitting the velocity surface to a model. The new instrument presented here can take thousands of acoustic velocity measurements per second. The spatial and velocity resolution can be adjusted by simple modification to the system; this is discussed in detail by comparison of theoretical expectations with experimental data. (paper)

  15. Crystalline orientation dependent photoresponse and heterogeneous behaviors of grain boundaries in perovskite solar cells

    Science.gov (United States)

    Jiang, Chuanpeng; Zhang, Pengpeng

    2018-02-01

    Using photoconductive atomic force microscopy and Kelvin probe force microscopy, we characterize the local electrical properties of grains and grain boundaries of organic-inorganic hybrid perovskite (CH3NH3PbI3) thin films on top of a poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS)/ITO substrate. Three discrete photoconductivity levels are identified among perovskite grains, likely corresponding to the crystal orientation of each grain. Local J-V curves recorded on these grains further suggest an anti-correlation behavior between the short circuit current (JSC) and open circuit voltage (VOC). This phenomenon can be attributed to diffusion-limited surface recombination at the non-selective perovskite-tip contact, where a higher carrier mobility established in the perovskite grain results in an enhanced surface recombination and thus a lower VOC. In addition, the photoresponse of perovskite films displays a pronounced heterogeneity across the grain boundaries, with the boundaries formed between grains of the same photoconductivity level displaying even enhanced photocurrent and open circuit voltage compared to those of the adjacent grain interiors. These observations highlight the significance of controlling the microstructure of perovskite thin films, which will be a necessary route for further improving the efficiency of perovskite solar cells.

  16. Magnetic uni- and tri-axial grain-orientation in superconductors with layered structures

    International Nuclear Information System (INIS)

    Horii, S.; Yamaki, M.; Ogino, H.; Maeda, T.; Shimoyama, J.

    2010-01-01

    We report the grain-orientation effects under a modulated rotation magnetic field for Y-based cuprate superconductors and LaFeAsO (La1111). Tri-axial orientation has been successfully achieved only for orthorhombic Y 2 Ba 4 Cu 7 O y and YBa 2 Cu 4 O 8 powders without a twin microstructure, while separation of three crystallographic axes could not be observed in twinned YBa 2 Cu 3 O y (Y123) and tetragonal La1111 powders. The morphology of grains, in addition to the symmetry of crystal structures, seriously affects the degrees of tri-axial orientation, which means that the control of twin microstructures is required for the tri-axial magnetic orientation in Y123.

  17. Anisotropy and intergrain current density in oriented grained bulk YBa2Cu3Ox superconductor

    International Nuclear Information System (INIS)

    Selvamanickam, V.; Salama, K.

    1990-01-01

    The intergrain transport current density and its anisotropy have been studied in oriented grained bulk YBa 2 Cu 3 O x superconductors fabricated by the liquid phase processing method. Current density measurements were performed on oriented grained samples with the transport current aligned at different angles to the a-b plane. In these measurements, the transport current passed through several oriented grain boundaries. The results indicate that the critical current density drops rapidly when the transport current flows at small angles to the a-b plane and then decreases slowly at larger angles. At 77 K and zero magnetic field, an anisotropy ratio of about 25 is observed between J c along a-b plane and that perpendicular to the plane. Further, the critical current density in these samples is found to depend weakly on magnetic field even though the current crosses grain boundaries. These results support the notion that grain boundaries of these superconductors are different in nature from those of solid-state sintered samples.

  18. Shape preferred orientation of iron grains compatible with Earth's uppermost inner core hemisphericity

    Science.gov (United States)

    Calvet, Marie; Margerin, Ludovic

    2018-01-01

    Constraining the possible patterns of iron fabrics in the Earth's Uppermost Inner Core (UIC) is key to unravel the mechanisms controlling its growth and dynamics. In the framework of crystalline micro-structures composed of ellipsoidal, aligned grains, we discuss possible textural models of UIC compatible with observations of P-wave attenuation and velocity dispersion. Using recent results from multiple scattering theory in textured heterogeneous materials, we compute the P-wave phase velocity and scattering attenuation as a function of grain volume, shape, and orientation wrt to the propagation direction of seismic P-waves. Assuming no variations of the grain volume between the Eastern and Western hemisphere, we show that two families of texture are compatible with the degree-one structure of the inner core as revealed by the positive correlation between seismic velocity and attenuation. (1) Strong flattening of grains parallel to the Inner Core Boundary in the Western hemisphere and weak anisometry in the Eastern hemisphere. (2) Strong radial elongation of grains in the Western hemisphere and again weak anisometry in the Eastern hemisphere. Both textures can quantitatively explain the seismic data in a limited range of grain volumes. Furthermore, the velocity and attenuation anisotropy locally observed under Africa demands that the grains be locally elongated in the direction of Earth's meridians. Our study demonstrates that the hemispherical seismic structure of UIC can be entirely explained by changes in the shape and orientation of grains, thereby offering an alternative to changes in grain volumes. In the future, our theoretical toolbox could be used to systematically test the compatibility of textures predicted by geodynamical models with seismic observations.

  19. Quantitative characterization of the orientation spread within individual grains in copper after tensile deformation

    DEFF Research Database (Denmark)

    Krog-Pedersen, Stine; Bowen, Jacob R.; Pantleon, Wolfgang

    2009-01-01

    By means of electron backscatter diffraction, orientations are determined on a regular grid on a polished section of a copper specimen after tensile deformation to 25%. Individual grains separated by boundaries with disorientation angles above 7° are identified and the microtexture in the form...

  20. Grain orientation mapping of passivated aluminum interconnect wires with X-ray micro-diffraction

    International Nuclear Information System (INIS)

    MacDowell, A.A.; Padmore, H.A.; Thompson, A.C.; Chang, C.H.; Patel, J.R.

    1998-06-01

    A micro x-ray diffraction facility is under development at the Advanced Light source. Spot sizes are typically about 1-microm size generated by means of grazing incidence Kirkpatrick-Baez focusing mirrors. Photon energy is either white of energy range 6--14 keV or monochromatic generated from a pair of channel cut crystals. A Laue diffraction pattern from a single grain in passivated 2-microm wide bamboo structured Aluminum interconnect line has been recorded. Acquisition times are of the order of a few seconds. The Laue pattern has allowed the determination of the crystallographic orientation of individual grains along the line length. The experimental and analysis procedures used are described, as is a grain orientation result. The future direction of this program is discussed in the context of strain measurements in the area of electromigration

  1. Grain orientation mapping of passivated aluminum interconnect lines with X-ray micro-diffraction

    International Nuclear Information System (INIS)

    Chang, C.H.; Patel, J.R.; MacDowell, A.A.; Padmore, H.A.; Thompson, A.C.

    1998-01-01

    A micro x-ray diffraction facility is under development at the Advanced Light Source. Spot sizes are typically about 1-microm size generated by means of grazing incidence Kirkpatrick-Baez focusing mirrors. Photon energy is either white of energy range 6--14 keV or monochromatic generated from a pair of channel cut crystals. Laue diffraction pattern from a single grain in a passivated 2-microm wide bamboo structured Aluminum interconnect line has been recorded. Acquisition times are of the order of seconds. The Laue pattern has allowed the determination of the crystallographic orientation of individual grains along the line length. The experimental and analysis procedure used is described, as is the latest grain orientation result. The impact of x-ray micro-diffraction and its possible future direction are discussed in the context of other developments in the area of electromigration, and other technological problems

  2. Grain orientation mapping of passivated aluminum interconnect lines by x-ray micro-diffraction

    International Nuclear Information System (INIS)

    Chang, C. H.; Patel, J. R.; MacDowell, A. A.; Padmore, H. A.; Thompson, A. C.

    1998-01-01

    A micro x-ray diffraction facility is under development at the Advanced Light Source. Spot sizes are typically about 1-μm size generated by means of grazing incidence Kirkpatrick-Baez focusing mirrors. Photon energy is either white of energy range 6-14 keV or monochromatic generated from a pair of channel cut crystals. Laue diffraction pattern from a single grain in a passivated 2-μm wide bamboo structured Aluminum interconnect line has been recorded. Acquisition times are of the order of seconds. The Laue pattern has allowed the determination of the crystallographic orientation of individual grains along the line length. The experimental and analysis procedure used is described, as is the latest grain orientation result. The impact of x-ray micro-diffraction and its possible future direction are discussed in the context of other developments in the area of electromigration, and other technological problems

  3. Machine Learning and Infrared Thermography for Fiber Orientation Assessment on Randomly-Oriented Strands Parts

    Science.gov (United States)

    Maldague, Xavier

    2018-01-01

    The use of fiber reinforced materials such as randomly-oriented strands has grown in recent years, especially for manufacturing of aerospace composite structures. This growth is mainly due to their advantageous properties: they are lighter and more resistant to corrosion when compared to metals and are more easily shaped than continuous fiber composites. The resistance and stiffness of these materials are directly related to their fiber orientation. Thus, efficient approaches to assess their fiber orientation are in demand. In this paper, a non-destructive evaluation method is applied to assess the fiber orientation on laminates reinforced with randomly-oriented strands. More specifically, a method called pulsed thermal ellipsometry combined with an artificial neural network, a machine learning technique, is used in order to estimate the fiber orientation on the surface of inspected parts. Results showed that the method can be potentially used to inspect large areas with good accuracy and speed. PMID:29351240

  4. Machine Learning and Infrared Thermography for Fiber Orientation Assessment on Randomly-Oriented Strands Parts.

    Science.gov (United States)

    Fernandes, Henrique; Zhang, Hai; Figueiredo, Alisson; Malheiros, Fernando; Ignacio, Luis Henrique; Sfarra, Stefano; Ibarra-Castanedo, Clemente; Guimaraes, Gilmar; Maldague, Xavier

    2018-01-19

    The use of fiber reinforced materials such as randomly-oriented strands has grown in recent years, especially for manufacturing of aerospace composite structures. This growth is mainly due to their advantageous properties: they are lighter and more resistant to corrosion when compared to metals and are more easily shaped than continuous fiber composites. The resistance and stiffness of these materials are directly related to their fiber orientation. Thus, efficient approaches to assess their fiber orientation are in demand. In this paper, a non-destructive evaluation method is applied to assess the fiber orientation on laminates reinforced with randomly-oriented strands. More specifically, a method called pulsed thermal ellipsometry combined with an artificial neural network, a machine learning technique, is used in order to estimate the fiber orientation on the surface of inspected parts. Results showed that the method can be potentially used to inspect large areas with good accuracy and speed.

  5. Electrodeposited copper oxide films: Effect of bath pH on grain orientation and orientation-dependent interfacial behavior

    International Nuclear Information System (INIS)

    Wang, L.C.; Tacconi, N.R. de; Chenthamarakshan, C.R.; Rajeshwar, K.; Tao, M.

    2007-01-01

    Copper (I) oxide (Cu 2 O) films were cathodically electrodeposited on Sn-doped indium oxide substrates. The influence of electrodeposition bath pH on grain orientation and crystallite shape was carefully re-examined using X-ray diffraction and scanning electron microscopy. In addition to the (100) and (111) preferred orientations identified in two previous sets of studies, as the bath pH was varied in the present study from ∼ 7.5 to ∼ 12, a third preferred orientation, (110), was identified in a narrow pH range, ∼ 9.4 to ∼ 9.9. A remarkable shift in the flat-band potential (spanning ∼ 500 mV) was measured in a non-aqueous electrolyte medium for the various Cu 2 O samples obtained from baths of varying pH

  6. Effects of seed orientation on the growth behavior of single grain REBCO bulk superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Gyoun [Korea Polytechnic University, Siheung (Korea, Republic of)

    2017-06-15

    This study presents a simple method to control the seed orientation which leads to the various growth characteristics of a single grain REBCO (RE: rare-earth elements) bulk superconductors. Seed orientation was varied systematically from c-axis to a-axis with every 30 degree rotation around b-axis. Orientations of a REBCO single grain was successfully controlled by placing the seed with various angles on the prismatic indent prepared on the surface of REBCO powder compacts. Growth pattern was changed from cubic to rectangular when the seed orientation normal to compact surface was varied from c-axis to a-axis. Macroscopic shape change has been explained by the variation of the wetting angle of un-reacted melt depending on the interface energy between YBa2Cu3O7-y (Y123) grain and melt. Higher magnetic levitation force was obtained for the specimen prepared using tilted seed with an angle of 30 degree rotation around b-axis.

  7. Relative effect(s) of texture and grain size on magnetic properties in a low silicon non-grain oriented electrical steel

    International Nuclear Information System (INIS)

    PremKumar, R.; Samajdar, I.; Viswanathan, N.N.; Singal, V.; Seshadri, V.

    2003-01-01

    Hot rolled low Si (silicon) non-grain oriented electrical steel was cold rolled to different reductions. Cold rolled material was subsequently recrystallized, 650 deg. C and 2 h, and then temper rolled (to 7% reduction) for the final grain growth annealing and decarburization treatment at 850 deg. C for 2-24 h. The development of texture, grain size and magnetic properties were characterized at different stages of processing. Effect of texture on magnetic properties (watt loss and permeability) was observed to be best represented by the ratio of volume fractions of (1 1 1) /(0 0 1) fibers, as estimated by convoluting X-ray ODFs (orientation distribution functions) with respective model functions. Such a ratio was termed as generalized texture factor (tf) for the non-grain oriented electrical steel. An effort was made to delink effects of grain size and texture, as represented by respective tf, on watt loss and permeability by careful analysis of experimental data. In general, low tf and/or high grain size were responsible for low watt loss and high permeability. However, individual effect of grain size or tf on magnetic properties was less significant at low tf or large grain size, respectively. An attempt was made to fit regression equations, namely--linear, exponential and power, relating magnetic properties with tf and grain size, limiting the fitting parameters to 3. Least standard deviations, between experimental and predicted values, were obtained by power regression equations for both magnetic properties

  8. Three-dimensional investigation of grain orientation effects on void growth in commercially pure titanium

    International Nuclear Information System (INIS)

    Pushkareva, Marina; Adrien, Jérôme; Maire, Eric; Segurado, Javier; Llorca, Javier; Weck, Arnaud

    2016-01-01

    The fracture process of commercially pure titanium was visualized in model materials containing artificial holes. These model materials were fabricated using a femtosecond laser coupled with a diffusion bonding technique to obtain voids in the interior of titanium samples. Changes in void dimensions during in-situ straining were recorded in three dimensions using x-ray computed tomography. Void growth obtained experimentally was compared with the Rice and Tracey model which predicted well the average void growth. A large scatter in void growth data was explained by differences in grain orientation which was confirmed by crystal plasticity simulations. It was also shown that grain orientation has a stronger effect on void growth than intervoid spacing and material strength. Intervoid spacing, however, appears to control whether the intervoid ligament failure is ductile or brittle.

  9. Three-dimensional investigation of grain orientation effects on void growth in commercially pure titanium

    Energy Technology Data Exchange (ETDEWEB)

    Pushkareva, Marina [Department of Mechanical Engineering, University of Ottawa, 150 Louis Pasteur, Ottawa, ON, Canada K1N 6N5 (Canada); Adrien, Jérôme; Maire, Eric [Université de Lyon, INSA-Lyon, MATEIS CNRS UMR5510, 7 Avenue Jean Capelle, F-69621 Villeurbanne (France); Segurado, Javier; Llorca, Javier [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Department of Materials Science, Polytechnic University of Madrid, E. T. S. de Ingenieros de Caminos, 28040 Madrid (Spain); Weck, Arnaud, E-mail: aweck@uottawa.ca [Department of Mechanical Engineering, University of Ottawa, 150 Louis Pasteur, Ottawa, ON, Canada K1N 6N5 (Canada); IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, ON, Canada K1N 6N5 (Canada); Centre for Research in Photonics at the University of Ottawa, 800 King Edward Ave., Ottawa, ON, Canada K1N 6N5 (Canada)

    2016-08-01

    The fracture process of commercially pure titanium was visualized in model materials containing artificial holes. These model materials were fabricated using a femtosecond laser coupled with a diffusion bonding technique to obtain voids in the interior of titanium samples. Changes in void dimensions during in-situ straining were recorded in three dimensions using x-ray computed tomography. Void growth obtained experimentally was compared with the Rice and Tracey model which predicted well the average void growth. A large scatter in void growth data was explained by differences in grain orientation which was confirmed by crystal plasticity simulations. It was also shown that grain orientation has a stronger effect on void growth than intervoid spacing and material strength. Intervoid spacing, however, appears to control whether the intervoid ligament failure is ductile or brittle.

  10. Evolution of surface topography in dependence on the grain orientation during surface thermal fatigue of polycrystalline copper

    CERN Document Server

    Aicheler, M; Taborelli, M; Calatroni, S; Neupert, H; Wuensch, W; Sgobba, S

    2011-01-01

    Surface degradation due to cyclic thermal loading plays a major role in the Accelerating Structures (AS) of the future Compact Linear Collider (CLIC) In this article results on surface degradation of thermally cycled polycrystalline copper as a function of the orientation of surface grains are presented Samples with different grain sizes were subjected to thermal fatigue using two different methods and were then characterized using roughness measurements and Orientation Imaging Scanning-Electron-Microscopy (OIM-SEM) Samples fatigued by a pulsed laser show the same trend in the orientation-fatigue damage accumulation as the sample fatigued by pulsed Radio-Frequency-heating (RF) it is clearly shown that 11 1 1] surface grains develop significantly more damage than the surface grains oriented in {[}100] and three reasons for this behaviour are pointed out Based on observations performed near grain boundaries their role in the crack initiation process is discussed The results are in good agreement with previous f...

  11. Determination of lattice orientation in aluminium alloy grains by low energy gallium ion-channelling

    Energy Technology Data Exchange (ETDEWEB)

    Silk, Jonathan R. [Aerospace Metal Composites Ltd., RAE Road, Farnborough, GU14 6XE (United Kingdom); Dashwood, Richard J. [WMG, University of Warwick, Coventry, CV4 7AL (United Kingdom); Chater, Richard J., E-mail: r.chater@imperial.ac.u [Department of Materials, Imperial College, London SW7 2AZ (United Kingdom)

    2010-06-15

    Polished sections of a fine-grained aluminium, silicon carbide metal matrix composite (MMC) alloy were prepared by sputtering using a low energy gallium ion source and column (FIB). The MMC had been processed by high temperature extrusion. Images of the polished surface were recorded using the ion-induced secondary electron emission. The metal matrix grains were distinguished by gallium ion-channelling contrast from the silicon carbide component. The variation of the contrast from the aluminium grains with tilt angle can be recorded and used to determine lattice orientation with the contrast from the silicon carbide (SiC) component as a reference. This method is rapid and suits site-specific investigations where classical methods of sample preparation fail.

  12. Effect of grain orientation and heat treatment on mechanical properties of pure W

    Energy Technology Data Exchange (ETDEWEB)

    Noto, Hiroyuki, E-mail: noto_hiroyuki@iae.kyoto-u.ac.jp [Graduate School of Energy Science, Kyoto University, Kyoto 611-0011 (Japan); Research Fellow of Japan Society for the Promotion of Science (Japan); Taniguchi, Shuichi [Graduate School of Energy Science, Kyoto University, Kyoto 611-0011 (Japan); Kurishita, Hiroaki; Matsuo, Satoru [International Research Center for Nuclear Materials Science, Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Ukita, Takashi; Tokunaga, Kazutoshi [Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Kimura, Akihiko [Institute of Advanced Energy, Kyoto University, Kyoto 611-0011 (Japan)

    2014-12-15

    The effect of grain orientation, heat-treatment temperature and test temperature on the mechanical properties of tungsten (W), which vary depending on plastic working and fabrication process, was investigated by mechanical testing of tensile or bending. Heavily worked W samples (1.5–2.0 mm in the final thickness) exhibit degradation of fracture strength due to recrystallization embrittlement after heat-treatment at 1240 °C (temperature of diffusion bonding between W and a candidate material of the Fe base support structure). On the other hand, W samples with lower thickness reduction rates do not suffer degradation of fracture strength after heating up to around 1300 °C, and show somewhat higher fracture strength by heat-treatment below 1300 °C than the samples in the as-received state. The observed behavior is a reflection of recovery of dislocations introduced by plastic working. High temperature tensile testing of ITER grade W with an anisotropic grain structure and S-TUN with an equiaxed grain structure revealed that both W grades exhibit plastic elongation at temperatures higher than 200 °C with essentially the same temperature dependence of yield strength, which is relatively insensitive to grain orientation in the structure at 200–1300 °C.

  13. Effect of grain orientation and heat treatment on mechanical properties of pure W

    International Nuclear Information System (INIS)

    Noto, Hiroyuki; Taniguchi, Shuichi; Kurishita, Hiroaki; Matsuo, Satoru; Ukita, Takashi; Tokunaga, Kazutoshi; Kimura, Akihiko

    2014-01-01

    The effect of grain orientation, heat-treatment temperature and test temperature on the mechanical properties of tungsten (W), which vary depending on plastic working and fabrication process, was investigated by mechanical testing of tensile or bending. Heavily worked W samples (1.5–2.0 mm in the final thickness) exhibit degradation of fracture strength due to recrystallization embrittlement after heat-treatment at 1240 °C (temperature of diffusion bonding between W and a candidate material of the Fe base support structure). On the other hand, W samples with lower thickness reduction rates do not suffer degradation of fracture strength after heating up to around 1300 °C, and show somewhat higher fracture strength by heat-treatment below 1300 °C than the samples in the as-received state. The observed behavior is a reflection of recovery of dislocations introduced by plastic working. High temperature tensile testing of ITER grade W with an anisotropic grain structure and S-TUN with an equiaxed grain structure revealed that both W grades exhibit plastic elongation at temperatures higher than 200 °C with essentially the same temperature dependence of yield strength, which is relatively insensitive to grain orientation in the structure at 200–1300 °C

  14. Grain orientation and strain measurements in sub-micron wide passivated individual aluminum test structures

    International Nuclear Information System (INIS)

    Tamura, N.; Valek, B.C.; Spolenak, R.; MacDowell, A.A.; Celestre, R.S.; Padmore, H.A.; Brown, W.L.; Marieb, T.; Bravman, J.C.; Batterman, B.W.; Patel, J.R.

    2001-01-01

    An X-ray microdiffraction dedicated beamline, combining white and monochromatic beam capabilities, has been built at the Advanced Light Source. The purpose of this beamline is to address the myriad of problems in Materials Science and Physics that require submicron x-ray beams for structural characterization. Many such problems are found in the general area of thin films and nano-materials. For instance, the ability to characterize the orientation and strain state in individual grains of thin films allows us to measure structural changes at a very local level. These microstructural changes are influenced heavily by such parameters as deposition conditions and subsequent treatment. The accurate measurement of strain gradients at the micron and sub-micron level finds many applications ranging from the strain state under nano-indenters to gradients at crack tips. Undoubtedly many other applications will unfold in the future as we gain experience with the capabilities and limitations of this instrument. We have applied this technique to measure grain orientation and residual stress in single grains of pure Al interconnect lines and preliminary results on post-electromigration test experiments are presented. It is shown that measurements with this instrument can be used to resolve the complete stress tensor (6 components) in a submicron volume inside a single grain of Al under a passivation layer with an overall precision of about 20 MPa. The microstructure of passivated lines appears to be complex, with grains divided into identifiable subgrains and noticeable local variations of both tensile/compressive and shear stresses within single grains

  15. Place oriented ecological footprint analysis. The case of Israel's grain supply

    International Nuclear Information System (INIS)

    Kissinger, Meidad; Gottlieb, Dan

    2010-01-01

    In today's world, any nation's ecological footprint is spread all over the globe. Still, most footprint studies are not yet sensitive to the specific locations on which the footprint falls and to the unique production characteristics of each supporting region. In recent years some studies have acknowledged the need to quantify the 'real land' footprints and particularly the share of the footprint embodied in trade. Our goal is to analyse the ecological footprint of grain-based consumption in the state of Israel during the last two decades. We present a detailed, place oriented calculation procedure of Israel's grain footprint on specific locations around the world. We document modes of production, major energy inputs in specific sources of supply, the energy required for shipping from each source, and the CO 2 emissions from those operations. Our research reveals that most of Israel's grain footprint falls on North America followed by the Black Sea region. It also shows that while the overall consumption of grain products has increased throughout the research period, the size of the footprint has been dropping in recent years as a consequence of changing sources of supply and grain composition. Finally, we discuss some of the implications of the method presented here for future footprint calculations and environmental resource management. (author)

  16. Effect of Primary Recrystallized Microstructure and Nitriding on Secondary Recrystallization in Grain Oriented Silicon Steel by Low Temperature Slab Reheating

    Directory of Open Access Journals (Sweden)

    LIU Gong-tao

    2018-01-01

    Full Text Available Different primary recrystallized grain sizes were obtained by controlling decarburization process in grain oriented silicon steel produced by low temperature slab reheating technique. The effect of primary grain size on secondary recrystallization and magnetic properties was studied. The appropriate nitrogen content after nitriding was explored in case of very large primary grain size, and the effect of {411}〈148〉 primary recrystallized texture on the abnormal growth behavior was discussed. The results show that an increase in average primary grain size from 10μm to 15μm leads to an increase of secondary recrystallization temperature and a sharper Goss texture with higher magnetic permeability, in the condition of a very large average primary grain size of 28μm, the suitable amount of nitrogen increases to about 6×10-4. The {411}〈148〉 oriented grains in primary recrystallized microstructure can easily grow into larger sizes due to their size advantage, and thus hinder the abnormal growth of secondary grains, moreover, the hindering effect is more pronounced in the abnormal growth of Brass-oriented grains due to their misorientation with low migration rate other than Goss grains.

  17. Nanocompositional Electron Microscopic Analysis and Role of Grain Boundary Phase of Isotropically Oriented Nd-Fe-B Magnets

    Directory of Open Access Journals (Sweden)

    Gregor A. Zickler

    2017-01-01

    Full Text Available Nanoanalytical TEM characterization in combination with finite element micromagnetic modelling clarifies the impact of the grain misalignment and grain boundary nanocomposition on the coercive field and gives guidelines how to improve coercivity in Nd-Fe-B based magnets. The nanoprobe electron energy loss spectroscopy measurements obtained an asymmetric composition profile of the Fe-content across the grain boundary phase in isotropically oriented melt-spun magnets and showed an enrichment of iron up to 60 at% in the Nd-containing grain boundaries close to Nd2Fe14B grain surfaces parallel to the c-axis and a reduced iron content up to 35% close to grain surfaces perpendicular to the c-axis. The numerical micromagnetic simulations on isotropically oriented magnets using realistic model structures from the TEM results reveal a complex magnetization reversal starting at the grain boundary phase and show that the coercive field increases compared to directly coupled grains with no grain boundary phase independently of the grain boundary thickness. This behaviour is contrary to the one in aligned anisotropic magnets, where the coercive field decreases compared to directly coupled grains with an increasing grain boundary thickness, if Js value is > 0.2 T, and the magnetization reversal and expansion of reversed magnetic domains primarily start as Bloch domain wall at grain boundaries at the prismatic planes parallel to the c-axis and secondly as Néel domain wall at the basal planes perpendicular to the c-axis. In summary our study shows an increase of coercive field in isotropically oriented Nd-Fe-B magnets for GB layer thickness > 5 nm and an average Js value of the GB layer < 0.8 T compared to the magnet with perfectly aligned grains.

  18. Diffraction-amalgamated grain boundary tracking for mapping 3D crystallographic orientation and strain fields during plastic deformation

    International Nuclear Information System (INIS)

    Toda, Hiroyuki; Kamiko, Takanobu; Tanabe, Yasuto; Kobayashi, Masakazu; Leclere, D.J.; Uesugi, Kentaro; Takeuchi, Akihisa; Hirayama, Kyosuke

    2016-01-01

    By amalgamating the X-ray diffraction technique with the grain boundary tracking technique, a novel method, diffraction-amalgamated grain boundary tracking (DAGT), has been developed. DAGT is a non-destructive in-situ analysis technique for characterising bulk materials, which can be applied up to near the point of fracture. It provides information about local crystal orientations and detailed grain morphologies in three dimensions, together with high-density strain mapping inside grains. As it obtains the grain morphologies by utilising X-ray imaging instead of X-ray diffraction, which latter is typically vulnerable to plastic deformation, DAGT is a fairly robust technique for analysing plastically deforming materials. Texture evolution and localised deformation behaviours have here been successfully characterised in Al–Cu alloys, during tensile deformation of 27% in applied strain. The characteristic rotation behaviours of grains were identified, and attributed to the effects of interaction with adjacent grains on the basis of the 3D local orientation and plastic strain distributions. It has also been revealed that 3D strain distribution in grains is highly heterogeneous, which is not explained by known mechanisms such as simple incompatibility with adjacent grains or strain percolation through soft grains. It has been clarified that groups consisting of a few adjacent grains may deform coordinately, especially in shear and lateral deformation, and the characteristic deformation pattern is thereby formed on a mesoscopic scale.

  19. Inductive current measurements in an oriented grained YBa2Cu3Ox superconductor

    International Nuclear Information System (INIS)

    Kupfer, H.; Keller, C.; Salama, K.; Selvamanickam, V.

    1989-01-01

    The critical current of grain aligned YBa 2 Cu 3 O x bulk material was investigated by inductive flux profile and ac susceptibility measurements. The induced current was directed perpendicular to the a-b plane oriented grains where high values of the transport current, have been previously reported. In spite of the unfavorable geometry of the investigated shielding current, no features of granularity were observed. The results yield a uniform bulk critical current density j c of 3x10 4 A/cm 2 at zero field and 77 K. Field and temperature dependences of this j c are discussed and compared with those in a granular Y-Ba-Cu-O material

  20. Analysis of microstructure and microtexture in grain-oriented electrical steel (GOES during manufacturing process

    Directory of Open Access Journals (Sweden)

    A. Volodarskaja

    2015-10-01

    Full Text Available The final Goss texture in grain-oriented electrical steels (GOES is affected by microstructure evolution and inheritance during the whole production process. This paper presents the results of detailed microtexture and microstructure investigations on GOES after the basic steps of the industrial AlN + Cu manufacturing process: hot rolling, first cold rolling + decarburization annealing, second cold rolling and final high temperature annealing. Microstructure studies showed that a copper addition to GOES affected solubility of sulphides. Copper rich sulphides dissolved during hot rolling and re-precipitated during decarburization annealing. An intensive precipitation of AlN and Si3N4 took place during decarburization annealing. No ε - Cu precipitation was detected. After high temperature annealing the misorientation of individual grains reached up to 8°.

  1. Transport current anisotropy in oriented grained bulk YBa2Cu3O(x) superconductor

    International Nuclear Information System (INIS)

    Selvamanickam, V.; Salama, K.

    1990-01-01

    The anisotropy in transport current density has been studied on bulk YBa2Cu3O(x) superconductor. The transport current density measurements were performed on oriented grained YBa2Cu3O(x) superconductor with the current aligned at different angles to the a-b plane. The angular dependence of Jc shows a rapid drop when the transport current is misaligned from the a-b plane at small angles and then a slow decrease at higher angles. An anisotropy ratio of about 25 is observed at 77 K and zero field between the Jc along a-b plane and that perpendicular to the plane. 15 refs

  2. Transport current anisotropy in oriented grained bulk YBa2Cu3Ox superconductor

    International Nuclear Information System (INIS)

    Selvamanickam, V.; Salama, K.

    1990-01-01

    The anisotropy in transport current density has been studied on bulk YBa 2 Cu 3 O x superconductor. The transport current density measurements were performed on oriented grained YBa 2 Cu 3 O x superconductor with the current aligned at different angles to the a endash b plane. The angular dependence of J c shows a rapid drop when the transport current is misaligned from the a endash b plane at small angles and then a slow decrease at higher angles. An anisotropy ratio of about 25 is observed at 77 K and zero field between the J c along a endash b plane and that perpendicular to the plane

  3. Selective Electron Beam Manufacturing of Ti-6Al-4V Strips: Effect of Build Orientation, Columnar Grain Orientation, and Hot Isostatic Pressing on Tensile Properties

    Science.gov (United States)

    Wang, J.; Tang, H. P.; Yang, K.; Liu, N.; Jia, L.; Qian, M.

    2018-03-01

    Many novel designs for additive manufacturing (AM) contain thin-walled (≤ 3 mm) sections in different orientations. Selective electron beam melting (SEBM) is particularly suited to AM of such thin-walled titanium components because of its high preheating temperature and high vacuum. However, experimental data on SEBM of Ti-6Al-4V thin sections remains scarce because of the difficulty and high cost of producing long, thin and smooth strip tensile specimens (see Fig. 1). In this study, 80 SEBM Ti-6Al-4V strips (180 mm long, 42 mm wide, 3 mm thick) were built both vertically (V-strips) and horizontally (H-strips). Their density, microstructure and tensile properties were investigated. The V-strips showed clearly higher tensile strengths but lower elongation than the H-strips. Hot isostatic pressing (HIP) produced the same lamellar α-β microstructures in terms of the average α-lath thickness in both types of strips. The retained prior-β columnar grain boundaries after HIP showed no measurable influence on the tensile properties, irrespective of their length and orientation, because of the formation of randomly distributed fine α-laths.[Figure not available: see fulltext.

  4. Giant piezoelectric voltage coefficient in grain-oriented modified PbTiO3 material.

    Science.gov (United States)

    Yan, Yongke; Zhou, Jie E; Maurya, Deepam; Wang, Yu U; Priya, Shashank

    2016-10-11

    A rapid surge in the research on piezoelectric sensors is occurring with the arrival of the Internet of Things. Single-phase oxide piezoelectric materials with giant piezoelectric voltage coefficient (g, induced voltage under applied stress) and high Curie temperature (T c ) are crucial towards providing desired performance for sensing, especially under harsh environmental conditions. Here, we report a grain-oriented (with 95% texture) modified PbTiO 3 ceramic that has a high T c (364 °C) and an extremely large g 33 (115 × 10 -3  Vm N -1 ) in comparison with other known single-phase oxide materials. Our results reveal that self-polarization due to grain orientation along the spontaneous polarization direction plays an important role in achieving large piezoelectric response in a domain motion-confined material. The phase field simulations confirm that the large piezoelectric voltage coefficient g 33 originates from maximized piezoelectric strain coefficient d 33 and minimized dielectric permittivity ɛ 33 in [001]-textured PbTiO 3 ceramics where domain wall motions are absent.

  5. Strain Amount Dependent Grain Size and Orientation Developments during Hot Compression of a Polycrystalline Nickel Based Superalloy

    Directory of Open Access Journals (Sweden)

    Guoai He

    2017-02-01

    Full Text Available Controlling grain size in polycrystalline nickel base superalloy is vital for obtaining required mechanical properties. Typically, a uniform and fine grain size is required throughout forging process to realize the superplastic deformation. Strain amount occupied a dominant position in manipulating the dynamic recrystallization (DRX process and regulating the grain size of the alloy during hot forging. In this article, the high-throughput double cone specimen was introduced to yield wide-range strain in a single sample. Continuous variations of effective strain ranging from 0.23 to 1.65 across the whole sample were achieved after reaching a height reduction of 70%. Grain size is measured to be decreased from the edge to the center of specimen with increase of effective strain. Small misorientation tended to generate near the grain boundaries, which was manifested as piled-up dislocation in micromechanics. After the dislocation density reached a critical value, DRX progress would be initiated at higher deformation region, leading to the refinement of grain size. During this process, the transformations from low angle grain boundaries (LAGBs to high angle grain boundaries (HAGBs and from subgrains to DRX grains are found to occur. After the accomplishment of DRX progress, the neonatal grains are presented as having similar orientation inside the grain boundary.

  6. Random walk analysis of grain motion during superplastic deformation of TZP

    International Nuclear Information System (INIS)

    Okamoto, T; Yasuda, K; Shiota, T

    2009-01-01

    This study focuses on grain motion in TZP (Tetragonal Zirconia Polycrystal) ceramics during superplastic deformation. The specimen was 16 times elongated repeatedly at 1400 0 C in air. The increment of true plastic strain was set to be 2%, and the specimen was deformed up to 30.3% true plastic strain finally. After each deformation, displacement vectors of specified 748 grains were measured from their position vectors determined by FE-SEM micrographs. As a result, the grains move to the tensile loading direction in zigzag way. And also, the zigzag motion changes with plastic strain: The grains move randomly (random walk motion) by the first 15% true plastic strain, and then grain motion becomes spatially uniform gradually. It is related to changes of constraint of surrounding matrix.

  7. Structure analysis of aluminium silicon manganese nitride precipitates formed in grain-oriented electrical steels

    International Nuclear Information System (INIS)

    Bernier, Nicolas; Xhoffer, Chris; Van De Putte, Tom; Galceran, Montserrat; Godet, Stéphane

    2013-01-01

    We report a detailed structural and chemical characterisation of aluminium silicon manganese nitrides that act as grain growth inhibitors in industrially processed grain-oriented (GO) electrical steels. The compounds are characterised using energy dispersive X-ray spectrometry (EDX) and energy filtered transmission electron microscopy (EFTEM), while their crystal structures are analysed using X-ray diffraction (XRD) and TEM in electron diffraction (ED), dark-field, high-resolution and automated crystallographic orientation mapping (ACOM) modes. The chemical bonding character is determined using electron energy loss spectroscopy (EELS). Despite the wide variation in composition, all the precipitates exhibit a hexagonal close-packed (h.c.p.) crystal structure and lattice parameters of aluminium nitride. The EDX measurement of ∼ 900 stoichiometrically different precipitates indicates intermediate structures between pure aluminium nitride and pure silicon manganese nitride, with a constant Si/Mn atomic ratio of ∼ 4. It is demonstrated that aluminium and silicon are interchangeably precipitated with the same local arrangement, while both Mn 2+ and Mn 3+ are incorporated in the h.c.p. silicon nitride interstitial sites. The oxidation of the silicon manganese nitrides most likely originates from the incorporation of oxygen during the decarburisation annealing process, thus creating extended planar defects such as stacking faults and inversion domain boundaries. The chemical composition of the inhibitors may be written as (AlN) x (SiMn 0.25 N y O z ) 1−x with x ranging from 0 to 1. - Highlights: • We study the structure of (Al,Si,Mn)N inhibitors in grain oriented electrical steels. • Inhibitors have the hexagonal close-packed symmetry with lattice parameters of AlN. • Inhibitors are intermediate structures between pure AlN and (Si,Mn)N with Si/Mn ∼ 4. • Al and Si share the same local arrangement; Mn is incorporated in both Mn 2+ and Mn 3+ . • Oxygen

  8. Randomly oriented twin domains in electrodeposited silver dendrites

    Directory of Open Access Journals (Sweden)

    Ivanović Evica R.

    2015-01-01

    Full Text Available Silver dendrites were prepared by electrochemical deposition. The structures of Ag dendrites, the type of twins and their distribution were investigated by scanning electron microscopy (SEM, Z-contrast high angle annular dark field transmission electron microscopy (HAADF, and crystallografically sensitive orientation imaging microscopy (OIM. The results revealed that silver dendrites are characterized by the presence of randomly distributed 180° rotational twin domains. The broad surface of dendrites was of the {111} type. Growth directions of the main dendrite stem and all branches were of type. [Projekat Ministarstva nauke Republike Srbije, br. 172054

  9. Magnetic losses reduction in grain oriented silicon steel by pulse and continuous fiber laser processing

    Science.gov (United States)

    Petryshynets, Ivan; Kováč, František; Puchý, Viktor; Šebek, Martin; Füzer, Ján; Kollár, Peter

    2018-04-01

    The present paper shows the impact of different laser scribing conditions on possible reduction of magnetic losses in grain oriented electrical steel sheets. The experimental Fe-3%Si steel was taken from industrial line after final box annealing. The surface of investigated steel was subjected to fiber laser processing using both pulse and continuous scribing regimes in order to generate residual thermal stresses inducing the magnetic domains structure refinement. The magnetic losses of experimental samples before and after individual laser scribing regimes were tested in AC magnetic field with 50Hz frequency and induction of 1.5T. The most significant magnetic losses reduction of 38% was obtained at optimized conditions of continuous laser scribing regime. A semi quantitative relationship has been found between the domain patterns and the used fiber laser processing.

  10. Magnetic losses reduction in grain oriented silicon steel by pulse and continuous fiber laser processing

    Directory of Open Access Journals (Sweden)

    Ivan Petryshynets

    2018-04-01

    Full Text Available The present paper shows the impact of different laser scribing conditions on possible reduction of magnetic losses in grain oriented electrical steel sheets. The experimental Fe-3%Si steel was taken from industrial line after final box annealing. The surface of investigated steel was subjected to fiber laser processing using both pulse and continuous scribing regimes in order to generate residual thermal stresses inducing the magnetic domains structure refinement. The magnetic losses of experimental samples before and after individual laser scribing regimes were tested in AC magnetic field with 50Hz frequency and induction of 1.5T. The most significant magnetic losses reduction of 38% was obtained at optimized conditions of continuous laser scribing regime. A semi quantitative relationship has been found between the domain patterns and the used fiber laser processing.

  11. Scaling-based prediction of magnetic anisotropy in grain-oriented steels

    Directory of Open Access Journals (Sweden)

    Najgebauer Mariusz

    2017-06-01

    Full Text Available The paper presents the scaling-based approach to analysis and prediction of magnetic anisotropy in grain-oriented steels. Results of the anisotropy scaling indicate the existence of two universality classes. The hybrid approach to prediction of magnetic anisotropy, combining the scaling analysis with the ODFs method, is proposed. This approach is examined in prediction of angular dependencies of magnetic induction as well as magnetization curves for the 111-35S5 steel. It is shown that it is possible to predict anisotropy of magnetic properties based on measurements in three arbitrary directions for φ = 0°, 60° and 90°. The relatively small errors between predicted and measured values of magnetic induction are obtained.

  12. Thin grain oriented electrical steel for PWM voltages fed magnetic cores

    Directory of Open Access Journals (Sweden)

    Thierry Belgrand

    2018-04-01

    Full Text Available This paper reports on performances of high permeability grain oriented electrical steel when used in association with power electronic switching devices. Loss measurement results obtained from the Epstein test, using sinusoidal or various PWM voltages in medium frequency range, show that for both studied thicknesses (HGO 0.23mm and HGO 0.18mm, comparing performances at a fixed induction level between the various situations may not be the most convenient method. The effect of magnetic domain refinement has been investigated. After having shown the interest of lowering the thickness, an alternative way of looking at losses is proposed that may help to design the magnetic core when it comes to the matter of reducing size in considering frequency and magnetization levels.

  13. Numerical Simulation of Shear Slitting Process of Grain Oriented Silicon Steel using SPH Method

    Directory of Open Access Journals (Sweden)

    Bohdal Łukasz

    2017-12-01

    Full Text Available Mechanical cutting allows separating of sheet material at low cost and therefore remains the most popular way to produce laminations for electrical machines and transformers. However, recent investigations revealed the deteriorating effect of cutting on the magnetic properties of the material close to the cut edge. The deformations generate elastic stresses in zones adjacent to the area of plastically deformed and strongly affect the magnetic properties. The knowledge about residual stresses is necessary in designing the process. This paper presents the new apprach of modeling residual stresses induced in shear slitting of grain oriented electrical steel using mesh-free method. The applications of SPH (Smoothed Particle Hydrodynamics methodology to the simulation and analysis of 3D shear slitting process is presented. In experimental studies, an advanced vision-based technology based on digital image correlation (DIC for monitoring the cutting process is used.

  14. An ultrasonic methodology to non-destructively estimate the grain orientation in an anisotropic weld

    Directory of Open Access Journals (Sweden)

    Wirdelius Håkan

    2014-06-01

    Full Text Available The initial step towards a non-destructive technique that estimates grain orientation in an anisotropic weld is presented in this paper. The purpose is to aid future forward simulations of ultrasonic NDT of this kind of weld to achieve a better result. A forward model that consists of a weld model, a transmitter model, a receiver model and a 2D ray tracing algorithm is introduced. An inversion based on a multi-objective genetic algorithm is also presented. Experiments are conducted for both P and SV waves in order to collect enough data used in the inversion. Calculation is conducted to fulfil the estimation with both the synthetic data and the experimental data. Concluding remarks are presented at the end of the paper.

  15. Effects of DC bias on magnetic performance of high grades grain-oriented silicon steels

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Guang; Cheng, Ling [Global Energy Interconnection Research Institute, State Key Laboratory of Advanced Transmission Technology,Beijing 102211 (China); Lu, Licheng [State Grid Corporation of China, Beijing 100031 (China); Yang, Fuyao; Chen, Xin [Global Energy Interconnection Research Institute, State Key Laboratory of Advanced Transmission Technology,Beijing 102211 (China); Zhu, Chengzhi [State Grid Zhejiang Electric Power Company, Hangzhou 310007 (China)

    2017-03-15

    When high voltage direct current (HVDC) transmission adopting mono-polar ground return operation mode or unbalanced bipolar operation mode, the invasion of DC current into neutral point of alternating current (AC) transformer will cause core saturation, temperature increasing, and vibration acceleration. Based on the MPG-200D soft magnetic measurement system, the influence of DC bias on magnetic performance of 0.23 mm and 0.27 mm series (P{sub 1.7}=0.70–1.05 W/kg, B{sub 8}>1.89 T) grain-oriented (GO) silicon steels under condition of AC / DC hybrid excitation were systematically realized in this paper. For the high magnetic induction GO steels (core losses are the same), greater thickness can lead to stronger ability of resisting DC bias, and the reasons for it were analyzed. Finally, the magnetostriction and A-weighted magnetostriction velocity level of GO steel under DC biased magnetization were researched. - Highlights: • Magnetic properties of 0.23 mm and 0.27 mm series (P{sub 1.7}=0.70–1.05 W/kg, B{sub 8}>1.89 T) grain-oriented (GO) silicon steels under condition of AC / DC hybrid excitation were systematically analyzed. • Influence of DC biased magnetization on core loss, magnetostriction, and A-weighted magnetostriction velocity level of GO steel were researched. • Greater thickness and relatively lower magnetic induction (B{sub 8}>1.89 T yet) of GO steel can lead to stronger ability of resisting DC bias, and the reasons for it were analyzed.

  16. Formation of {1 0 0} textured columnar grain structure in a non-oriented electrical steel by phase transformation

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Li; Yang, Ping, E-mail: yangp@mater.ustb.edu.cn; Zhang, Ning; Zong, Cui; Xia, Dongsheng; Mao, Weimin

    2014-04-01

    This study confirms the effect of anisotropic strain energy on the formation of {1 0 0} textured columnar grain structure induced by temperature gradient during γ to α phase transformation in pure hydrogen atmosphere. Results indicate that high temperature gradient in pure hydrogen atmosphere induces a significant strain energy difference across grain boundaries during γ to α phase transformation, leading to the formation of {1 0 0} texture with columnar grains. Given its simplicity in processing and its ability to obtain good texture-related magnetic properties, the proposed approach is helpful to the development of new types of non-oriented electrical steel. - Highlights: • A strong {1 0 0} texture with columnar grains was obtained. • Good texture and magnetic properties are attributed to the anisotropic strain energy. • The anisotropy in elastic strain energy was induced by the temperature gradient. • The phase transformation rate affects columnar grain morphology.

  17. Transmission and Andreev reflection in one-dimensional chain with randomly doped superconducting grains

    International Nuclear Information System (INIS)

    Hu Dongsheng; Xiong Shijie

    2002-01-01

    We investigate the transport properties and Andreev reflection in one-dimensional (1D) systems with randomly doped superconducting grains. The superconducting grains are described by the Bogoliubov-de Gene Hamiltonian and the conductance is calculated by using the transfer matrix method and Landauer-Buettiker formula. It is found that although the quasiparticle states are localized due to the randomness and the low dimensionality, the conductance is still kept finite in the thermodynamical limit due to the Andreev reflection. We also investigate the effect of correlation of disorder in such systems and the results show the delocalization of quasiparticle states and suppression of Andreev reflection in a wide energy window

  18. 78 FR 59059 - Grain-Oriented Electrical Steel From China, Czech Republic, Germany, Japan, Korea, Poland, and...

    Science.gov (United States)

    2013-09-25

    ...)] Grain-Oriented Electrical Steel From China, Czech Republic, Germany, Japan, Korea, Poland, and Russia... Republic, Germany, Japan, Korea, Poland, and Russia that are alleged to be sold in the United States at less than fair value. Unless the Department of Commerce extends the time for initiation pursuant to...

  19. Anomalous diffusion on 2d randomly oriented diode networks

    International Nuclear Information System (INIS)

    Aydiner, E.; Kiymach, K.

    2002-01-01

    In this work, we have studied the diffusion properties of a randomly oriented two- dimensional diode network, using Monte Carlo Simulation method. The characteristic exponent α of the diffusion is obtained against the reverse transition probability W γ . We have found two critical values of W γ ; 0.003 and 0.4. α has been found to be 0.376 for W γ ≤ 0.003, and ≅ 1 for W γ ≥ 0.4 . For W γ >0.4 normal diffusion, and for 0.003≤W γ ≤0.4 anomalous sub-diffusion are observed. But for W γ ≤0.003 there seems to be no diffusion at all

  20. A DETERMINATION OF THE FLUX DENSITY IN CORE OF DISTRIBUTION TRANSFORMERS, WHAT BUILT WITH THE COMMON USING OF GRAIN AND NON GRAIN ORIENTED MAGNETIC STEELS

    Directory of Open Access Journals (Sweden)

    I.V. Pentegov

    2015-12-01

    Full Text Available Purpose. The development of calculation method to determinate the flux densities in different parts of the magnetic cores of distribution transformers, what built from different types magnetic steel (mixed core. Methodology. The method is based on the scientific positions of Theoretical Electrical Engineering – the theory of the electromagnetic field in nonlinear mediums to determine the distribution of magnetic flux in mixed core of transformer, what are using different types of steel what have the different magnetic properties. Results. The developed method gives possible to make calculation of the flux density and influence of skin effect in different parts of the magnetic cores of distribution transformer, where are used mix of grain oriented (GO and non grain oriented (NGO steels. Was determinate the general basic conditions for the calculation of flux density in the laminations from grain and non grain oriented steels of the magnetic core: the strength of magnetic field for the laminations of particular part of mixed core is the same; the sum of the magnetic fluxes in GO and NGO steels in particular part of mixed core is equal with the designed magnetic flux in this part of mixed core. Discover, the magnetic flux in mixed core of the transformer has specific distribution between magnetic steels. The flux density is higher in laminations from GO steel and smaller in laminations from the NGO steel. That is happened because for magnetic flux is easier pass through laminations from GO steel, what has better magnetic conductance than laminations from NGO steel. Originality. The common using of different types of magnetic steels in cores for distribution transformers gives possibility to make design of transformer with low level of no load losses, high efficiency and with optimal cost. Practical value. The determination of the flux density in different parts of magnetic core with GO and NGO steels gives possibility make accurate calculation of

  1. Micromagnetic simulation of the orientation dependence of grain boundary properties on the coercivity of Nd-Fe-B sintered magnets

    Directory of Open Access Journals (Sweden)

    Jun Fujisaki

    2016-05-01

    Full Text Available This paper is focused on the micromagnetic simulation study about the orientation dependence of grain boundary properties on the coercivity of polycrystalline Nd-Fe-B sintered magnets. A multigrain object with a large number of meshes is introduced to analyze such anisotropic grain boundaries and the simulation is performed by combining the finite element method and the parallel computing. When the grain boundary phase parallel to the c-plane is less ferromagnetic the process of the magnetization reversal changes and the coercivity of the multigrain object increases. The simulations with various magnetic properties of the grain boundary phases are executed to search for the way to enhance the coercivity of polycrystalline Nd-Fe-B sintered magnets.

  2. Precipitation and Evolution Behavior of Second Phase Particles in Grain-oriented Silicon Steel with Cu

    Directory of Open Access Journals (Sweden)

    LI Zhi-chao

    2017-12-01

    Full Text Available The precipitation behavior and distribution of second phase particles in conventional grain-oriented silicon steel during manufacturing process were observed by field emission scanning electron microscopy, and the average particle size, the areal particle density, and the Zener factor were statistically analyzed. The results show that the samples mainly contain two kinds of precipitates:A class is the (Cu,MnS composite precipitates with the average size of 1μm; B class is the Cu2S precipitates with the size of 10-30nm, the key inhibition effect is produced by Cu2S. Hot rolling leads to a large amount of fine second phase particles precipitation, which has the minimum average particle size and the highest areal density; in the manufacturing process before high temperature annealing, the average particle size is increasing and the areal density is decreasing; in the process of high temperature annealing, with the decrease of volume fraction of precipitates, the inhibition ability exhibits reducing trend,obvious aggregation occurs at 960℃,secondary recrystallization will happen when Zener factor A decreases below the critical value of 0.19nm-1, and the residual particles will not produce valid inhibition effect.

  3. Orientation-dependent evolution of the dislocation density in grain populations with different crystallographic orientations relative to the tensile axis in a polycrystalline aggregate of stainless steel

    International Nuclear Information System (INIS)

    Ungár, Tamás; Stoica, Alexandru D.; Tichy, Géza; Wang, Xun-Li

    2014-01-01

    Line profile analysis was carried out on neutron diffraction patterns collected by the energy-dispersive method for an in situ tensile-deformed AISI-316 stainless steel specimen. The experiments were carried out at the VULCAN engineering beam line of the spallation neutron source of the Oak Ridge National Laboratory. Both the dislocation densities and the local stresses in grains oriented with different h k l crystal directions along the tensile axis were determined. The work-hardening equation of Taylor was tested for the h k l-dependent phenomenological constant α. The grain-orientation-dependent α values were directly related to the heterogeneity of dislocation distribution in correlation with previous transmission electron microscopy data

  4. Influence of Substrate on Crystal Orientation of Large-Grained Si Thin Films Formed by Metal-Induced Crystallization

    Directory of Open Access Journals (Sweden)

    Kaoru Toko

    2015-01-01

    Full Text Available Producing large-grained polycrystalline Si (poly-Si film on glass substrates coated with conducting layers is essential for fabricating Si thin-film solar cells with high efficiency and low cost. We investigated how the choice of conducting underlayer affected the poly-Si layer formed on it by low-temperature (500°C Al-induced crystallization (AIC. The crystal orientation of the resulting poly-Si layer strongly depended on the underlayer material: (100 was preferred for Al-doped-ZnO (AZO and indium-tin-oxide (ITO; (111 was preferred for TiN. This result suggests Si heterogeneously nucleated on the underlayer. The average grain size of the poly-Si layer reached nearly 20 µm for the AZO and ITO samples and no less than 60 µm for the TiN sample. Thus, properly electing the underlayer material is essential in AIC and allows large-grained Si films to be formed at low temperatures with a set crystal orientation. These highly oriented Si layers with large grains appear promising for use as seed layers for Si light-absorption layers as well as for advanced functional materials.

  5. Orientations of recrystallization nuclei developed in columnar-grained Ni at triple junctions

    DEFF Research Database (Denmark)

    Xu, C.L.; Huang, S.; Zhang, Yubin

    2015-01-01

    A high purity columnar grained nickel sample with a strong <001> fiber texture was cold rolled to 50% reduction in thickness, followed by annealing at different temperatures. Optical microscopy was used to depict the grain boundaries prior to annealing and to detect nuclei formed on grain boundar...

  6. Influence of orientation mismatch on charge transport across grain boundaries in tri-isopropylsilylethynyl (TIPS) pentacene thin films.

    Science.gov (United States)

    Steiner, Florian; Poelking, Carl; Niedzialek, Dorota; Andrienko, Denis; Nelson, Jenny

    2017-05-03

    We present a multi-scale model for charge transport across grain boundaries in molecular electronic materials that incorporates packing disorder, electrostatic and polarisation effects. We choose quasi two-dimensional films of tri-isopropylsilylethynyl pentacene (TIPS-P) as a model system representative of technologically relevant crystalline organic semiconductors. We use atomistic molecular dynamics, with a force-field specific for TIPS-P, to generate and equilibrate polycrystalline two-dimensional thin films. The energy landscape is obtained by calculating contributions from electrostatic interactions and polarization. The variation in these contributions leads to energetic barriers between grains. Subsequently, charge transport is simulated using a kinetic Monte-Carlo algorithm. Two-grain systems with varied mutual orientation are studied. We find relatively little effect of long grain boundaries due to the presence of low impedance pathways. However, effects could be more pronounced for systems with limited inter-grain contact areas. Furthermore, we present a lattice model to generalize the model for small molecular systems. In the general case, depending on molecular architecture and packing, grain boundaries can result in interfacial energy barriers, traps or a combination of both with qualitatively different effects on charge transport.

  7. Grain Oriented Perovskite Layer Structure Ceramics for High-Temperature Piezoelectric Applications

    Science.gov (United States)

    Fuierer, Paul Anton

    The perovskite layer structure (PLS) compounds have the general formula (A^{2+}) _2(B^{5+})_2 O_7, or (A^ {3+})_2(B^{4+ })_2O_7, and crystallize in a very anisotropic layered structure consisting of parallel slabs made up of perovskite units. Several of these compounds possess the highest Curie temperatures (T_{rm c} ) of any known ferroelectrics. Two examples are Sr_2Nb_2O _7 with T_{rm c} of 1342^circC, and La_2Ti_2O _7 with T_{rm c} of 1500^circC. This thesis is an investigation of PLS ceramics and their feasibility as a high temperature transducer material. Piezoelectricity in single crystals has been measured, but the containerless float zone apparatus necessary to grow high quality crystals of these refractory compounds is expensive and limited to a small number of research groups. Previous attempts to pole polycrystalline Sr_2Nb _2O_7 have failed, and to this point piezoelectricity has been absent. The initiative taken in this research was to investigate PLS ceramics by way of composition and processing schemes such that polycrystalline bodies could be electrically poled. The ultimate objective then was to demonstrate piezoelectricity in PLS ceramics, especially at high temperatures. Donor-doping of both La_2Ti _2O_7 and Sr_2Nb_2O _7 was found to increase volume resistivities at elevated temperatures, an important parameter to consider during the poling process. Sr_2Ta _2O_7 (T _{rm c} = -107 ^circC) was used to make solid solution compositions with moderately high Curie temperatures, of about 850^circC, and lower coercive fields. A hot-forging technique was employed to produce ceramics with high density (>99% of theoretical) and high degree of grain orientation (>90%). Texturing was characterized by x-ray diffraction and microscopy. Considerable anisotropy was observed in physical and electrical properties, including thermal expansion, resistivity, dielectric constant, and polarization. The direction perpendicular to the forging axis proved to be the

  8. Interactions between the phase stress and the grain-orientation-dependent stress in duplex stainless steel during deformation

    International Nuclear Information System (INIS)

    Jia, N.; Peng, R. Lin; Wang, Y.D.; Chai, G.C.; Johansson, S.; Wang, G.; Liaw, P.K.

    2006-01-01

    The development of phase stress and grain-orientation-dependent stress under uniaxial compression was investigated in a duplex stainless steel consisting of austenite and ferrite. Using in situ neutron diffraction measurements, the strain response of several h k l planes to the applied compressive stress was mapped as a function of applied stress and sample direction. Analysis based on the experimental results and elastoplastic self-consistent simulations shows that phase stresses of thermal origin further increase during elastic loading but decrease with increased plastic deformation. Grain-orientation-dependent stresses become significant in both austenite and ferrite after loading into the plastic region. After unloading from the plastic regime, a considerable intergranular stress remains in the austenitic phase and dominates over the phase stress. This study provides fundamental experimental inputs for future micromechanical modeling aiming at the evaluation and prediction of the mechanical performance of multiphase materials

  9. Preparation and characterization of Grain-Oriented Barium Titanate Ceramics Using Electrophoresis Deposition Method under A High Magnetic Field

    Energy Technology Data Exchange (ETDEWEB)

    Kita, T; Kondo, S; Takei, T; Kumada, N; Nakashima, K; Fujii, I; Wada, S [Material Science and Technology, Interdisciplinary Graduate School of Medical and Engineering, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi 400-8510 (Japan); Suzuki, T S; Uchikoshi, T; Sakka, Y [National Institute for materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Miwa, Y; Kawada, S; Kimura, M, E-mail: swada@yamanashi.ac.jp [Murata Manufacturing Co., Ltd. 2288 Ooshinohara, Yasu, Shiga 520-2393 (Japan)

    2011-10-29

    Barium titanate (BaTiO{sub 3}) grain-oriented ceramics were prepared using electrophoresis deposition (EPD) method under high magnetic field of 12 T. First, BaTiO{sub 3} nanoparticles with high c/a ratio of 1.008 and size of 84 nm were prepared by two-step thermal decomposition method with barium titanyl oxalate nanoparticles. Using the BaTiO{sub 3} slurry, BaTiO{sub 3} nanoparticle accumulations were prepared by EPD method under high magnetic field. After binder burnout, the accumulations were sintered and BaTiO{sub 3} grain-oriented ceramics were prepared. Moreover, dielectric properties of their ceramics were investigated

  10. Thin resolver using the easy magnetization axis of the grain-oriented silicon steel as an angle indicator

    Directory of Open Access Journals (Sweden)

    Jisho Oshino

    2017-05-01

    Full Text Available A new type of thin resolver is presented, in which the easy axis of the magnetic anisotropy in the grain-oriented silicon steel is used as an angle indicator. The total thickness including a rotor, PCB coils and a back yoke can be made less than 4 mm. With a rotor of 50 mm diameter, a good linear response (non-linearity error < 0.4% between the mechanical angle input and the electrical angle output has been obtained. The influence of a weak magnetic anisotropy in the non-grain-oriented silicon steel used for the back yoke on the accuracy of the resolver can be deleted by the method proposed in this paper.

  11. Localised corrosion in AA 2099-T83 aluminium-lithium alloy: The role of grain orientation

    International Nuclear Information System (INIS)

    Ma, Y.; Zhou, X.; Liao, Y.; Yi, Y.; Wu, H.; Wang, Z.; Huang, W.

    2016-01-01

    Highlights: • Schmid factor of the grain/subgrain can indicate its corrosion susceptibility. • The localised corrosion prefers the grain with relatively large Schmid factor. • The localised corrosion is related to selective dissolution of T_1 phase. - Abstract: The mechanism for localised corrosion in AA 2099-T83 alloy during immersion in 3.5% NaCl solution is investigated. It is found that localised corrosion tends to occur in the grain with relatively large Schmid factor. The localised corrosion is related to selective dissolution of T_1 (Al_2CuLi) phase that preferentially precipitates at grain/subgrain boundaries and dislocations within grain interiors. A model is proposed to explain the development of the localised corrosion in the alloy by taking into account heterogeneous plastic deformation during cold working and preferential precipitation of T_1 phase at crystallographic defects within deformed grains.

  12. CREATION OF EXPORT-ORIENTED NETWORK OF GRAIN ELEVATORS IN UKRAINE

    Directory of Open Access Journals (Sweden)

    D. M. Kozachenko

    2017-04-01

    Full Text Available Purpose. The scientific paper highlights improving the efficiency of export rail transportation of grain cargoes in Ukraine by introducing shipper routing and concentration of loading at the terminal grain elevators. Methodology. According to the experience of the USA and Canada, one of the most effective ways to reduce costs in the grain to-port supply chain is a shipper routing of the rail traffic. Shipper routing for transportation of grain cargoes involves the concentration of their loading on the multiple junctions. The junctions are proposed to be selected with the use of cluster analysis methods. For the formation of the grain loading concentration areas the authors used methods of set theory and multi-criteria optimization. Findings. Based on agglomerative cluster analysis algorithm, the junctions on a network of Ukrainian railways are selected and the areas of possible concentration of grain loading are formed. DSU-algorithm allowed distinguishing the overlapping and non-overlapping areas of concentration. The problem of selecting non-overlapping areas of the grain loading concentration is formalized as the problem of multiobjective integer programming with boolean variables. The solution of this problem by a modified simplex algorithm allows selecting on the railway network of Ukraine 24 districts of possible grain loading concentration, which cover 70 stations and at minimal additional cost provide routing of about 7.5 million tons of grain per year. Originality. The originality of the work lies in the fact that the authors developed the mathematical procedure for selection of junctions and concentration areas of grain loading at the Ukrainian railway network, taking into account the economic efficiency of the process. Practicalvalue. Application of the developed method of grain loading concentration for the formation of unit trains will significantly reduce the logistics costs in the supply chain of grain to Ukrainian ports for

  13. A novel ultra-low carbon grain oriented silicon steel produced by twin-roll strip casting

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yang, E-mail: wy069024019@163.com [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Zhang, Yuan-Xiang; Lu, Xiang; Fang, Feng; Xu, Yun-Bo; Cao, Guang-Ming; Li, Cheng-Gang [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Misra, R.D.K. [Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical, Materials and Biomedical Engineering, University of Texas at El Paso, TX 79968 (United States); Wang, Guo-Dong [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China)

    2016-12-01

    A novel ultra-low carbon grain oriented silicon steel was successfully produced by strip casting and two-stage cold rolling method. The microstructure, texture and precipitate evolution under different first cold rolling reduction were investigated. It was shown that the as-cast strip was mainly composed of equiaxed grains and characterized by very weak Goss texture ({110}<001>) and λ-fiber (<001>//ND). The coarse sulfides of size ~100 nm were precipitated at grain boundaries during strip casting, while nitrides remained in solution in the as-cast strip and the fine AlN particles of size ~20–50 nm, which were used as grain growth inhibitors, were formed in intermediate annealed sheet after first cold rolling. In addition, the suitable Goss nuclei for secondary recrystallization were also formed during intermediate annealing, which is totally different from the conventional process that the Goss nuclei originated in the subsurface layer of the hot rolled sheet. Furthermore, the number of AlN inhibitors and the intensity of desirable Goss texture increased with increasing first cold rolling reduction. After secondary recrystallization annealing, very large grains of size ~10–40 mm were formed and the final magnetic induction, B{sub 8}, was as high as 1.9 T. - Highlights: • A novel chemical composition base on strip casting silicon steel was proposed. • The ultra-low carbon design could shorten the processing routes. • The novel composition and processes were beneficial to obtain more inhibitors. • The magnetic induction of grain oriented silicon steel was significantly improved.

  14. Precipitation of grain boundary α in a laser deposited compositionally graded Ti-8Al-xV alloy - an orientation microscopy study

    International Nuclear Information System (INIS)

    Banerjee, R.; Bhattacharyya, D.; Collins, P.C.; Viswanathan, G.B.; Fraser, H.L.

    2004-01-01

    A graded ternary Ti-8Al-xV alloy (all compositions in wt%) has been deposited using the laser engineered net-shaping (LENS TM ) process. A compositional gradient in the alloy, from binary Ti-8Al to Ti-8Al-20V, has been achieved within a length of ∼25 mm. The feedstock used for depositing the graded alloy consisted of elemental Ti, Al, and V powders. Due to the columnar growth morphology of the β grains in these LENS TM deposited Ti alloys, the same prior β grain boundary often extends across lengths ∼10 mm. Using orientation microscopy techniques in a scanning electron microscope, the crystallography of precipitation of grain boundary α across the same boundary with changing composition has been investigated in detail. It was observed that while most grain boundary α precipitates maintain a Burgers or near-Burgers orientation relationship with only one of the β grains, a few of these precipitates develop a Burgers orientation relationship with the other β grain. In some rare instances, the grain boundary α did not develop a Burgers or near-Burgers orientation relationship with either β grains. Interestingly, in many cases while the grain boundary α maintained Burgers relationship with one of the β grains, precipitates of two different variants decorated the boundary, in a near-alternate fashion

  15. Magnetic field and temperature dependence of flux creep in oriented grained and single-crystalline YBa2Cu3Ox

    International Nuclear Information System (INIS)

    Keller, C.; Kuepfer, H.; Gurevich, A.; Meier-Hirmer, R.; Wolf, T.; Fluekiger, R.; Selvamanickam, V.; Salama, K.

    1990-01-01

    Thermally activated flux creep of oriented grained and single-crystalline YBa 2 Cu 3 O x was studied in fields up to 12 T and at temperatures ranging between 4 and 90 K. In fixed fields the activation energy U 0 of both samples was found to increase with temperature, pass through some maximum and drop to the order of k B T around the irreversibility line. While at constant temperature U 0 of the oriented grained sample showed a monotonous decrease with field; in the case of the single crystal it was found to follow a characteristic minimum-maximum structure paralleled by the previously observed field dependence of the shielding current. This clearly demonstrates the influence of the coupling properties, i.e., bulk behavior of the oriented grained sample and granularity of the single crystal, on relaxation. Therefore, models exclusively based either on a pinning or on a junction approach alone could not describe our experimental findings. A more appropriate explanation is based on the properties of the defect structure. Depending on field and temperature, defective regions are driven into the normal state whereby additional pinning centers are created which in turn give rise to increasing activation energies. The connectivity of the sample then depends on size and density of these defects

  16. Influence of grain size and additions of Al and Mn on the magnetic properties of non-oriented electrical steels with 3 wt. (% Si

    Directory of Open Access Journals (Sweden)

    Rodrigo Felix de Araujo Cardoso

    2008-03-01

    Full Text Available The influence of hot-band grain size and additions of aluminum and manganese on the magnetic properties of non-oriented grain (NOG low-carbon electrical steel with about 3 wt. (% Si were investigated using optical microscopy and X ray diffraction. The addition of manganese resulted in larger grains after final annealing. Coarse grains in the hot-band and addition of Mn led to a Goss orientation component after final annealing, which resulted in an increase in the magnetic permeability.

  17. Effect of non-metallic precipitates and grain size on core loss of non-oriented electrical silicon steels

    Science.gov (United States)

    Wang, Jiayi; Ren, Qiang; Luo, Yan; Zhang, Lifeng

    2018-04-01

    In the current study, the number density and size of non-metallic precipitates and the size of grains on the core loss of the 50W800 non-oriented electrical silicon steel sheets were investigated. The number density and size of precipitates and grains were statistically analyzed using an automatic scanning electron microscope (ASPEX) and an optical microscope. Hypothesis models were established to reveal the physical feature for the function of grain size and precipitates on the core loss of the steel. Most precipitates in the steel were AlN particles smaller than 1 μm so that were detrimental to the core loss of the steel. These finer AlN particles distributed on the surface of the steel sheet. The relationship between the number density of precipitates (x in number/mm2 steel area) and the core loss (P1.5/50 in W/kg) was regressed as P1.5/50 = 4.150 + 0.002 x. The average grain size was approximately 25-35 μm. The relationship between the core loss and grain size (d in μm) was P1.5/50 = 3.851 + 20.001 d-1 + 60.000 d-2.

  18. The random phase transducer in ultrasonic NDT of coarse grain stainless steel

    International Nuclear Information System (INIS)

    Bordier, J.M.; Fink, M.; Le Brun, A.; Cohen-Tenoudji, F.

    1993-11-01

    Ultrasonic NDT of cast stainless steel is known to be difficult due to a huge loss of focussing of the ultrasonic beam, and to a high level speckle noise generated by the coarse grain structure. In this paper, we describe the principle of the ultrasonic random phase transducer. Experimental results are compared with those obtained with a standard spatial compound technique. We show that the random phase transducer is a good tool to characterize the multiple scattering process generated by these materials. (authors). 7 figs., 11 refs

  19. Effect of deformation mode and grain orientation on misorientation development in a body-centered cubic steel

    International Nuclear Information System (INIS)

    Kang, J.-Y.; Bacroix, B.; Regle, H.; Oh, K.H.; Lee, H.-C.

    2007-01-01

    Strain-induced misorientation development was studied in an IF steel as a function of strain for two deformation modes, plane strain compression and simple shear. Using electron back-scattered diffraction, orientation maps of 'large' areas were obtained, from which several individual grains associated with the principal texture components could be extracted so that only intragranular misorientations could be estimated for these orientations. It was observed that the increase of the misorientation angle was more prominent in simple shear than in plane strain compression and that the orientation influence was different for each mode. Considering texture evolution as a possible source of misorientation development, the lattice spin tensor was estimated with the Taylor model for the two deformation modes; both reorientation axis and angle were compared with misorientation angle and axis. The striking concordance of both quantities allows us to conclude that there is a direct contribution of texture evolution to misorientation accumulation with strain

  20. On the orientation dependent grain boundary migration in an Fe-6at.%Si alloy

    International Nuclear Information System (INIS)

    Lejcek, P.; Adamek, J.

    1995-01-01

    The [100]symmetrical tilt grain boundaries in an Fe-6at.%Si alloy were found to exhibit as pronounced anisotropy of activation enthalpy of migration characterized by its high values for special boundaries as compared to general ones. This rather surprising posing three main contributions to the migration enthalpy: intrinsic migration enthalpy, migration enthalpy resulting from grain boundary segregation, and migration enthalpy resulting from alloy mixing. It is shown that the differences in migration enthalpy of special and general grain boundaries in a concentrated alloy reflect the prevailing character of the intrinsic migration enthalpy over the weakened segregation effects. (orig.)

  1. Comparison between measured and computed magnetic flux density distribution of simulated transformer core joints assembled from grain-oriented and non-oriented electrical steel

    Directory of Open Access Journals (Sweden)

    Hamid Shahrouzi

    2018-04-01

    Full Text Available The flux distribution in an overlapped linear joint constructed in the central region of an Epstein Square was studied experimentally and results compared with those obtained using a computational magnetic field solver. High permeability grain-oriented (GO and low permeability non-oriented (NO electrical steels were compared at a nominal core flux density of 1.60 T at 50 Hz. It was found that the experimental results only agreed well at flux densities at which the reluctance of different paths of the flux are similar. Also it was revealed that the flux becomes more uniform when the working point of the electrical steel is close to the knee point of the B-H curve of the steel.

  2. Influence of welding passes on grain orientation – The example of a multi-pass V-weld

    International Nuclear Information System (INIS)

    Ye, Jing; Moysan, Joseph; Song, Sung-Jin; Kim, Hak-Joon; Chassignole, Bertrand; Gueudré, Cécile; Dupond, Olivier

    2012-01-01

    The accurate modelling of grain orientations in a weld is important, when accurate ultrasonic test predictions of a welded assembly are needed. To achieve this objective, Electricité de France (EDF) and the Laboratoire de Caractérisation Non Destructive (LCND) have developed a dedicated code, which makes use of information recorded in the welding procedure. Among the welding parameters recorded, although the order in which the welding passes are made is of primary importance in the welding process, this information is not always well known or accurately described. In the present paper we analyse in greater detail the influence of the order of welding passes, using data obtained from the Centre for Advanced Non Destructive Evaluation (CANDE), derived from a dissimilar metal weld (DMW) with buttering. Comparisons are made using grain orientation measurements on a macrograph. - Highlights: ► Influence of welding process on grain structure is studied using the MINA model. ► For the first time the importance of a slight slope of the layers is evaluated. ► Two orders of passes are compared for the modelling approach. ► A major effect is observed due to a change in the order of passes.

  3. Fine-Grained Forward-Secure Signature Schemes without Random Oracles

    DEFF Research Database (Denmark)

    Camenisch, Jan; Koprowski, Maciej

    2006-01-01

    We propose the concept of fine-grained forward-secure signature schemes. Such signature schemes not only provide nonrepudiation w.r.t. past time periods the way ordinary forward-secure signature schemes do but, in addition, allow the signer to specify which signatures of the current time period...... remain valid when revoking the public key. This is an important advantage if the signer produces many signatures per time period as otherwise the signer would have to re-issue those signatures (and possibly re-negotiate the respective messages) with a new key.Apart from a formal model for fine......-grained forward-secure signature schemes, we present practical schemes and prove them secure under the strong RSA assumption only, i.e., we do not resort to the random oracle model to prove security. As a side-result, we provide an ordinary forward-secure scheme whose key-update time is significantly smaller than...

  4. Measurement of magnetic properties of grain-oriented silicon steel using round rotational single sheet tester (RRSST)

    International Nuclear Information System (INIS)

    Gorican, Viktor; Hamler, Anton; Jesenik, Marko; Stumberger, Bojan; Trlep, Mladen

    2004-01-01

    The magnetic properties of grain-oriented material under rotational magnetic flux condition were measured, using two different pairs of B coils with different angle with respect to the rolling direction. It is known that induced voltages in two perpendicularly positioned B coils do not represent the actual amplitude and the angular speed of vector B in the measuring region. Consequently, the control of the induced voltages in the B coils at different positions means that the sample is measured under different magnetic flux condition. This leads to a difference between the results of vector H and the rotational loss

  5. Movement and Orientation Decision Modeling of Rhyzopertha dominica (Coleoptera: Bostrichidae) in the Grain Mass.

    Science.gov (United States)

    Cordeiro, Erick M G; Campbell, James F; Phillips, Thomas W

    2016-04-01

    Grain stored in bins is initially a relatively homogenous resource patch for stored-product insects, but over time, spatial pattern in insect distribution can form, due in part to insect movement patterns. However, the factors that influence stored-product insect movement patterns in grain are not well-understood. This research focused on the movement of the lesser grain borer, Rhyzopertha dominica (F.), within a simulated wheat grain mass (vertical monolayer of wheat) and the identification of factors that contribute to overall and upward movement (age since adult emergence from an infested kernel [1, 7, and 14 d], sex, strain, and different levels of environment quality). We also used the model selection approach to select the most relevant factors and determine the relationships among them. Three-week-old adults tended to stay closer to the surface compared with 1- or 2-wk-old insects. Also, females tended to be more active and to explore a larger area compared with males. Explored area and daily displacement were also significantly strain-dependent, and increasing grain infestation level decreased daily displacement and explored area. Variation in movement pattern is likely to influence the formation of spatial pattern and affect probability to disperse. Understanding movement behavior within a grain bin is crucial to designing better strategies to implement and interpret monitoring programs and to target control tactics. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

  6. Reconstruction of Single-Grain Orientation Distribution Functions for Crystalline Materials

    DEFF Research Database (Denmark)

    Hansen, Per Christian; Sørensen, Henning Osholm; Sükösd, Zsuzsanna

    2009-01-01

    for individual grains of the material in consideration. We study two iterative large-scale reconstruction algorithms, the algebraic reconstruction technique (ART) and conjugate gradients for least squares (CGLS), and demonstrate that right preconditioning is necessary in both algorithms to provide satisfactory...

  7. Sensitivity analysis of Immersed Boundary Method simulations of fluid flow in dense polydisperse random grain packings

    Directory of Open Access Journals (Sweden)

    Knight Chris

    2017-01-01

    Full Text Available Polydisperse granular materials are ubiquitous in nature and industry. Despite this, knowledge of the momentum coupling between the fluid and solid phases in dense saturated grain packings comes almost exclusively from empirical correlations [2–4, 8] with monosized media. The Immersed Boundary Method (IBM is a Computational Fluid Dynamics (CFD modelling technique capable of resolving pore scale fluid flow and fluid-particle interaction forces in polydisperse media at the grain scale. Validation of the IBM in the low Reynolds number, high concentration limit was performed by comparing simulations of flow through ordered arrays of spheres with the boundary integral results of Zick and Homsy [10]. Random grain packings were studied with linearly graded particle size distributions with a range of coefficient of uniformity values (Cu = 1.01, 1.50, and 2.00 at a range of concentrations (ϕ ∈ [0.396; 0.681] in order to investigate the influence of polydispersity on drag and permeability. The sensitivity of the IBM results to the choice of radius retraction parameter [1] was investigated and a comparison was made between the predicted forces and the widely used Ergun correlation [3].

  8. Differentiation of grain orientation with corrosive and colour etching on a granular bainitic steel.

    Science.gov (United States)

    Reisinger, S; Ressel, G; Eck, S; Marsoner, S

    2017-08-01

    This study presents a detailed verification of the etching methods with Nital and Klemm on a granular bainitic steel. It is shown that both methods allow the identification of the crystal orientation, whereas Klemm etching enables also a quantification of the apparent phases, as also retained austenite can be distinguished from the other bainitic microstructures. A combination of atom probe tomography with electron-back-scattered-diffraction showed that both etching methods emphasize the bainitic {100} crystal orientation. However, a cross-section produced by focused ion beam evidenced that Klemm etching leads to the formation of a topography of the different oriented bainitic crystals that directly affects the thickness and therefore the apparent colour of the deposited layer formed during etching. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Evolution of microstructure, texture and inhibitor along the processing route for grain-oriented electrical steels using strip casting

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Yao, Sheng-Jie [School of Materials Science and Engineering, Harbin Institute of Technology at Weihai, 264209 (China); Sun, Yu; Gao, Fei; Song, Hong-Yu; Liu, Guo-Huai [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Li, Lei; Geng, Dian-Qiao [Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110819 (China); Liu, Zhen-Yu; Wang, Guo-Dong [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China)

    2015-08-15

    In the present work, a regular grade GO sheet was produced successively by strip casting, hot rolling, normalizing annealing, two-stage cold rolling with intermediate annealing, primary recrystallization annealing, secondary recrystallization annealing and purification. The aim of this paper was to characterize the evolution of microstructure, texture and inhibitor along the new processing route by comprehensive utilization of optical microscopy, X-ray diffraction and transmission electron microscopy. It was found that a fine microstructure with the ferrite grain size range of 7–12 μm could be obtained in the primary recrystallization annealed sheet though a very coarse microstructure was produced in the initial as-cast strip. The main finding was that the “texture memory” effect on Goss texture started on the through-thickness intermediate annealed strip after first cold rolling, which was not similar to the “texture memory” effect on Goss texture starting on the surface layers of the hot rolled strip in the conventional production route. As a result, the origin of Goss nuclei capable of secondary recrystallization lied in the grains already presented in Goss orientation in the intermediate annealed strip after first cold rolling. Another finding was that fine and dispersive inhibitors (mainly AlN) were easy to be produced in the primary recrystallization microstructure due to the initial rapid solidification during strip casting and the subsequent rapid cooling, and the very high temperature reheating usually used before hot rolling in the conventional production route could be avoided. - Highlights: • A regular grade grain-oriented electrical steel was produced. • Evolution of microstructure, texture and inhibitor was characterized. • Origin of Goss nuclei lied in the intermediate annealed strip. • A fine primary recrystallization microstructure could be produced. • Effective inhibitors were easy to be obtained in the new processing route.

  10. Giant strain with ultra-low hysteresis and high temperature stability in grain oriented lead-free K0.5Bi0.5TiO3-BaTiO3-Na0.5Bi0.5TiO3 piezoelectric materials.

    Science.gov (United States)

    Maurya, Deepam; Zhou, Yuan; Wang, Yaojin; Yan, Yongke; Li, Jiefang; Viehland, Dwight; Priya, Shashank

    2015-02-26

    We synthesized grain-oriented lead-free piezoelectric materials in (K0.5Bi0.5TiO3-BaTiO3-xNa0.5Bi0.5TiO3 (KBT-BT-NBT) system with high degree of texturing along the [001]c (c-cubic) crystallographic orientation. We demonstrate giant field induced strain (~0.48%) with an ultra-low hysteresis along with enhanced piezoelectric response (d33 ~ 190pC/N) and high temperature stability (~160°C). Transmission electron microscopy (TEM) and piezoresponse force microscopy (PFM) results demonstrate smaller size highly ordered domain structure in grain-oriented specimen relative to the conventional polycrystalline ceramics. The grain oriented specimens exhibited a high degree of non-180° domain switching, in comparison to the randomly axed ones. These results indicate the effective solution to the lead-free piezoelectric materials.

  11. Effect of hot band grain size on development of textures and magnetic properties in 2.0% Si non-oriented electrical steel sheet

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.M. [Department of Materials Science and Engineering, Korea University, 5-1, Anam-dong, Sungbuk-Gu, Seoul 136-701 (Korea, Republic of); Huh, M.Y., E-mail: myhuh@korea.ac.kr [Department of Materials Science and Engineering, Korea University, 5-1, Anam-dong, Sungbuk-Gu, Seoul 136-701 (Korea, Republic of); Lee, H.J.; Park, J.T.; Kim, J.S. [Electrical Steel Sheet Research Group, Technical Research Laboratories, POSCO, Goedong-dong, Pohang (Korea, Republic of); Shin, E.J. [Korea Atomic Energy Research Institute, Neutron Science Division, Daejeon 305-353 (Korea, Republic of); Engler, O. [Hydro Aluminium Rolled Products GmbH, Research and Development Bonn, P.O. Box 2468, D-53014 Bonn (Germany)

    2015-12-15

    The effect of hot band grain size on the development of crystallographic texture and magnetic properties in non-oriented electrical steel sheet was studied. After cold rolling the samples with different initial grain sizes displayed different microstructures and micro-textures but nearly identical macro-textures. The homogeneous recrystallized microstructure and micro-texture in the sample having small grains caused normal continuous grain growth. The quite irregular microstructure and micro-texture in the recrystallized sample with large initial grain size provided a preferential growth of grains in 〈001〉//ND and 〈113〉//ND which were beneficial for developing superior magnetic properties. - Highlights: • We produced hot bands of electrical steel with different grain size but same texture. • Hot band grain size strongly affected cold rolling and subsequent annealing textures. • Homogeneous recrystallized microstructure caused normal continuous grain growth. • Irregular recrystallized microstructure led to selective growth of <001>//ND grains. • Hot band with large grains was beneficial for superior magnetic properties.

  12. A fine-grained, customizable debugger for aspect-oriented programming

    NARCIS (Netherlands)

    Yin, Haihan; Leavens, G.T.; Chiba, S.; Bockisch, Christoph; Aksit, Mehmet; Tanter, E.

    2013-01-01

    To increase modularity, many aspect-oriented programming languages provide a mechanism based on implicit invocation: An aspect can influence runtime behavior of other modules without the need that these modules refer to the aspect. Recent studies show that a significant part of reported bugs in

  13. Effects of crystal structure and grain orientation on the roughness of deformed polycrystalline metals

    NARCIS (Netherlands)

    Wouters, Onne; Vellinga, WP; van Tijum, Redmer; De Hosson, JTM

    Surface roughening during tensile deformation of polycrystalline aluminum, iron and zinc is investigated using white light confocal microscopy and orientation imaging microscopy. A height-height correlation technique is used to analyze the data. The surface obeys self-affine scaling on length scales

  14. Influence of MgO containing strontium on the structure of ceramic film formed on grain oriented silicon steel surface

    Directory of Open Access Journals (Sweden)

    Daniela C. Leite Vasconcelos

    1999-07-01

    Full Text Available The oxide layer formed on the surface of a grain oriented silicon steel was characterized by SEM and EDS. 3% Si steel substrates were coated by two types of slurries: one formed by MgO and water and other formed by MgO, water and SrSO4. The ceramic films were evaluated by SEM, EDS and X-ray diffraction. Depth profiles of Fe, Si and Mg were obtained by GDS. The magnetic core losses (at 1.7 Tesla, 60 Hz of the coated steel samples were evaluated as well. The use of MgO containing strontium reduced the volume fraction of forsterite particles beneath the outermost ceramic layer. It was observed a reduced magnetic core loss with the use of the slurry with MgO containing strontium.

  15. Microstructure and crystallographic preferred orientation of polycrystalline microgarnet aggregates developed during progressive creep, recovery, and grain boundary sliding

    Science.gov (United States)

    Massey, M.A.; Prior, D.J.; Moecher, D.P.

    2011-01-01

    Optical microscopy, electron probe microanalysis, and electron backscatter diffraction methods have been used to examine a broad range of garnet microstructures within a high strain zone that marks the western margin of a major transpression zone in the southern New England Appalachians. Garnet accommodated variable states of finite strain, expressed as low strain porphyroclasts (Type 1), high strain polycrystalline aggregates (Type 2), and transitional morphologies (Type 3) that range between these end members. Type 1 behaved as rigid porphyroclasts and is characterized by four concentric Ca growth zones. Type 2 help define foliation and lineation, are characterized by three Ca zones, and possess a consistent bulk crystallographic preferred orientation of (100) symmetrical to the tectonic fabric. Type 3 show variable degrees of porphyroclast associated with aggregate, where porphyroclasts display complex compositional zoning that corresponds to lattice distortion, low-angle boundaries, and subgrains, and aggregate CPO mimics porphyroclast orientation. All aggregates accommodated a significant proportion of greenschist facies deformation through grain boundary sliding, grain rotation and impingement, and pressure solution, which lead to a cohesive behavior and overall strain hardening of the aggregates. The characteristic CPO could not have been developed in this manner, and was the result of an older phase of partitioned amphibolite facies dislocation creep, recovery including chemical segregation, and recrystallization of porphyroclasts. This study demonstrates the significance of strain accommodation within garnet and its affect on composition under a range of PT conditions, and emphasizes the importance of utilizing EBSD methods with studies that rely upon a sound understanding of garnet. ?? 2010 Elsevier Ltd.

  16. Mechanical properties and deformation mechanism of Mg-Al-Zn alloy with gradient microstructure in grain size and orientation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Liu; Yuan, Fuping; Jiang, Ping; Xie, Jijia; Wu, Xiaolei, E-mail: xlwu@imech.ac.cn

    2017-05-10

    The surface mechanical attrition treatment was taken to fabricate the gradient structure in AZ31 magnesium alloy sheet. Microstructural investigations demonstrate the formation of dual gradients with respect to grain size and orientation, where the microstructural sizes decreased from several microns to about 200 nm from center area to treated surface, while the c-axis gradually inclined from being vertical to treated plane towards parallel with it. According to tensile results, the gradient structured sample has yield strength of 305 MPa in average, which is increased by about 4 times when compared with its coarse-grained counterpart. Meanwhile, contrary to quickly failure after necking in most traditional magnesium alloys, the failure process of gradient structure appears more gently, which makes it has 6.5% uniform elongation but 11.5% total elongation. The further comparative tensile tests for separated gradient layers and corresponding cores demonstrate that the gradient structured sample has higher elongation either in uniform or in post-uniform stages. In order to elucidate the relationship between mechanical properties and deformation mechanisms for this dual gradient structure, the repeated stress relaxation tests and pole figure examinations via X-ray diffraction were conducted in constituent gradient layer and corresponding core, as well as gradient structured sample. The results show that the pyramidal dislocations in dual gradient structure are activated through the whole thickness of sample. Together with the contribution of grain-size gradient, more dislocations are activated in dual gradient structure under tensile loading, which results in stronger strain hardening and hence higher tensile ductility.

  17. Mechanical properties and deformation mechanism of Mg-Al-Zn alloy with gradient microstructure in grain size and orientation

    International Nuclear Information System (INIS)

    Chen, Liu; Yuan, Fuping; Jiang, Ping; Xie, Jijia; Wu, Xiaolei

    2017-01-01

    The surface mechanical attrition treatment was taken to fabricate the gradient structure in AZ31 magnesium alloy sheet. Microstructural investigations demonstrate the formation of dual gradients with respect to grain size and orientation, where the microstructural sizes decreased from several microns to about 200 nm from center area to treated surface, while the c-axis gradually inclined from being vertical to treated plane towards parallel with it. According to tensile results, the gradient structured sample has yield strength of 305 MPa in average, which is increased by about 4 times when compared with its coarse-grained counterpart. Meanwhile, contrary to quickly failure after necking in most traditional magnesium alloys, the failure process of gradient structure appears more gently, which makes it has 6.5% uniform elongation but 11.5% total elongation. The further comparative tensile tests for separated gradient layers and corresponding cores demonstrate that the gradient structured sample has higher elongation either in uniform or in post-uniform stages. In order to elucidate the relationship between mechanical properties and deformation mechanisms for this dual gradient structure, the repeated stress relaxation tests and pole figure examinations via X-ray diffraction were conducted in constituent gradient layer and corresponding core, as well as gradient structured sample. The results show that the pyramidal dislocations in dual gradient structure are activated through the whole thickness of sample. Together with the contribution of grain-size gradient, more dislocations are activated in dual gradient structure under tensile loading, which results in stronger strain hardening and hence higher tensile ductility.

  18. Effect of texture and grain size on magnetic flux density and core loss in non-oriented electrical steel containing 3.15% Si

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.M.; Park, S.Y. [Department of Materials Science and Engineering, Korea University, 5-1, Anam-dong, Sungbuk-Gu, Seoul 136-701 (Korea, Republic of); Huh, M.Y., E-mail: myhuh@korea.ac.kr [Department of Materials Science and Engineering, Korea University, 5-1, Anam-dong, Sungbuk-Gu, Seoul 136-701 (Korea, Republic of); Kim, J.S. [Electrical Steel Sheet Research Group, Technical Research Laboratories, POSCO, Goedong-dong, Pohang (Korea, Republic of); Engler, O. [Hydro Aluminium Rolled Products GmbH, R and D Center Bonn, P.O. Box 2468, D-53014 Bonn (Germany)

    2014-03-15

    In an attempt to differentiate the impact of grain size and crystallographic texture on magnetic properties of non-oriented (NO) electrical steel sheets, samples with different grain sizes and textures were produced and analyzed regarding magnetic flux density B and core loss W. The textures of the NO electrical steel samples could be precisely quantified with the help of elliptical Gaussian distributions. In samples with identical textures, small grain sizes resulted in about 15% higher core loss W than larger grains, whereas grain size only moderately affected the magnetic flux density B. In samples having nearly the same grain size, a correlation of the magneto-crystalline anisotropic properties of B and W with texture was obtained via the anisotropy parameter A(h{sup →}). With increasing A(h{sup →}) a linear decrease of B and a linear increase of W were observed. - Highlights: • We produced electrical steel sheets having different grain size and texture. • Magnetic flux density B and core loss W were varied with grain size and texture. • Correlation of B and W with texture was established via anisotropy parameter A(h{sup →}). • With increasing A(h{sup →}) a linear decrease of B and a linear increase of W were observed. • Grain size mainly affected W with only minor impact on B.

  19. Influence of specimen size and grain orientation to the life of a polycrystalline Ni-base alloy at LCF stress

    International Nuclear Information System (INIS)

    Seibel, Thomas

    2014-01-01

    In the present work the LCF (Low Cycle Fatigue) crack initiation life of the conventionally cast Ni-base alloy RENE 80 was analyzed as a function of specimen size and grain orientation. Five specimen geometries with distinctly different gauge sections were used: 3 geometries with cylindrical gauge section (G1-G3) and two notched geometries with a stress concentration factor of α 1 = 1,62 (KG1) and α 2 = 2,60 (KG2), resulting in a maximum difference of the damage relevant surface area up to a factor of approximately 72. Correction factors were determined by FEM calculations for all specimen geometries with highly reduced gauge sections where direct strain measurement was not possible. Additionally a uniform failure criterion with a relatively small crack size of 0,962 mm 2 was defined. Totally, 116 isothermal LCF tests were carried out at the different specimen types at a temperature of 850 C in total strain control with a load ratio (minimum strain / maximum strain) of R ε = -1. The load cycles were applied with triangular waveform at a frequency of 0.1 Hz for high strain amplitudes and 1 Hz for low strain amplitudes, respectively. After the LCF-Tests the fracture surfaces of all samples were analyzed in more detail by SEM to identify the crack initiation mechanisms as well as the crack initiation sites. In this context it could be shown, that fatigue cracks were generally initiated at slip bands in surface grains. Accordingly, the grain orientations at the crack initiation sites were measured by electron back scatter diffraction (EBSD) and the maximum shear stresses in the respective principal slip system (111) <110> was calculated using the Schmid approach. For this, longitudinal sections were be prepared exactly at the crack initiation sites of samples loaded with low strain amplitudes where clearly defined single crack initiation sites were observed. Afterwards the maximum shear stress in the principal slip system at the crack initiation site was correlated

  20. Effects by the microstructure after hot and cold rolling on the texture and grain size after final annealing of ferritic non-oriented FeSi electrical steel

    Science.gov (United States)

    Schneider, J.; Stöcker, A.; Franke, A.; Kawalla, R.

    2018-04-01

    The magnetic properties of fully processed non-oriented FeSi electrical steel are characterized by their magnetization behavior and specific magnetic losses. The magnetic properties are determined by the texture and microstructure. Less gamma fiber intensity and a high intensity of preferable texture components, especially cube fiber texture, are desirable to obtain an excellent magnetizing behavior. Furthermore, large grain sizes are necessary to reach low values of the specific magnetic losses. The fabrication route of the fully processed non-oriented electrical steels comprises a heavy cold rolling of the hot rolled material before final annealing. To fulfill the requirements on large grain size for low loss materials, grain growth, which appears after complete recrystallization, plays an important role. In this paper we will analyze the influence of different microstructures of the hot strip and the resulting microstructure after cold rolling on the appearance of recrystallization and grain growth after final annealing. The evolution of texture reflects the present ongoing softening processes: recovery, recrystallization and finally grain growth at the given annealing conditions. It will be shown that the image of texture at recrystallization is remarkable different from the texture at grain growth. Substantially grain growth is obtained at lower annealing temperatures for an optimum microstructure of the hot rolled material.

  1. Effects by the microstructure after hot and cold rolling on the texture and grain size after final annealing of ferritic non-oriented FeSi electrical steel

    Directory of Open Access Journals (Sweden)

    J. Schneider

    2018-04-01

    Full Text Available The magnetic properties of fully processed non-oriented FeSi electrical steel are characterized by their magnetization behavior and specific magnetic losses. The magnetic properties are determined by the texture and microstructure. Less gamma fiber intensity and a high intensity of preferable texture components, especially cube fiber texture, are desirable to obtain an excellent magnetizing behavior. Furthermore, large grain sizes are necessary to reach low values of the specific magnetic losses. The fabrication route of the fully processed non-oriented electrical steels comprises a heavy cold rolling of the hot rolled material before final annealing. To fulfill the requirements on large grain size for low loss materials, grain growth, which appears after complete recrystallization, plays an important role. In this paper we will analyze the influence of different microstructures of the hot strip and the resulting microstructure after cold rolling on the appearance of recrystallization and grain growth after final annealing. The evolution of texture reflects the present ongoing softening processes: recovery, recrystallization and finally grain growth at the given annealing conditions. It will be shown that the image of texture at recrystallization is remarkable different from the texture at grain growth. Substantially grain growth is obtained at lower annealing temperatures for an optimum microstructure of the hot rolled material.

  2. Influence of cold rolling direction on texture, inhibitor and magnetic properties in strip-cast grain-oriented 3% silicon steel

    Energy Technology Data Exchange (ETDEWEB)

    Fang, F., E-mail: fangfengdbdx@163.com [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China); Lu, X.; Zhang, Y.X.; Wang, Y.; Jiao, H.T.; Cao, G.M.; Yuan, G.; Xu, Y.B. [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China); Misra, R.D.K. [Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical, Materials and Biomedical Engineering, University of Texas at El Paso, EL Paso, TX 79968 (United States); Wang, G.D. [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China)

    2017-02-15

    An unconventional cold rolling scheme (inclined rolling at 0°, 30°, 45°, 90° during second-stage cold rolling process) was adopted to process grain-oriented silicon steel based on strip casting process. The influences of inclination angles on microstructure, texture, inhibitor and magnetic properties were studied by a combination of EBSD, XRD and TEM. It was found that the α-fiber texture was weakened and γ-fiber was strengthened in cold rolled sheet with increase in inclination angle. The primary recrystallization sheet exhibited more homogeneous microstructure with relatively strong γ-fiber, medium α-fiber texture, weak λ-fiber texture and Goss component at high inclination angles. Fine and homogeneous inhibitors were obtained after primary annealing with increase in inclination angle from 0° to 90° because of more uniform deformation after inclined rolling. The grain-oriented silicon steel experienced completely secondary recrystallization at various inclination angles after final annealing process, with superior magnetic properties at 0° and 90°. Furthermore, Goss nuclei capable of final secondary recrystallization in strip casting process newly formed both in-grain shear bands and grain boundaries region during second-stage cold rolling and subsequent annealing process, which is different from the well-accepted results that Goss texture originated from the subsurface layer of the hot rolled sheet or during intermediate annealing process. In addition, the Goss texture that nucleated in-grain shear bands was weaker but more accurate as compared to that in grain boundaries region. - Highlights: • Inclined cold rolling was adopted to process strip-cast grain-oriented silicon steel. • Influence of inclination angles on texture, inhibitor and magnetic properties was studied. • The initial texture was changed with respect to the inclination angle. • Homogeneous inhibitors were obtained after primary annealing at various inclination angles.

  3. Cardiovascular benefits from ancient grain bread consumption: findings from a double-blinded randomized crossover intervention trial.

    Science.gov (United States)

    Sereni, Alice; Cesari, Francesca; Gori, Anna Maria; Maggini, Niccolò; Marcucci, Rossella; Casini, Alessandro; Sofi, Francesco

    2017-02-01

    Ancient grain varieties have been shown to have some beneficial effects on health. Forty-five clinically healthy subjects were included in a randomized, double-blinded crossover trial aimed at evaluating the effect of a replacement diet with bread derived from ancient grain varieties versus modern grain variety on cardiovascular risk profile. After 8 weeks of intervention, consumption of bread obtained by the ancient varieties showed a significant amelioration of various cardiovascular parameters. Indeed, the ancient varieties were shown to result in a significant reduction of total cholesterol, low-density lipoprotein (LDL)-cholesterol and blood glucose, whereas no significant differences during the phase with the modern variety were reported. Moreover, a significant increase in circulating endothelial progenitor cells were reported after the consumption of products made from the ancient "Verna" variety. The present results suggest that a dietary consumption of bread obtained from ancient grain varieties was effective in reducing cardiovascular risk factors.

  4. Differential Effects of Red Meat/Refined Grain Diet and Dairy/Chicken/Nuts/Whole Grain Diet on Glucose, Insulin and Triglyceride in a Randomized Crossover Study.

    Science.gov (United States)

    Kim, Yoona; Keogh, Jennifer B; Clifton, Peter M

    2016-10-30

    Epidemiological studies suggest that a diet high in processed meat, with a high glycemic index is associated with an increased risk of type 2 diabetes. It is not clear if this is due to altered insulin sensitivity or an enhanced postprandial glucose. We aimed to compare the acute metabolic response of two different types of meals after ingestion of the matching diet for four weeks. The study was a randomized, crossover acute meal study. Volunteers consumed either a red meat/refined grain meal or a dairy/chicken/nuts/wholegrain meal after four weeks of the matching diet. After a three-week washout period and four weeks of the alternate diet, they consumed the matching meal. The diets differed with respect to both protein and carbohydrate sources. Blood samples were taken for 180 min for the measurement of glucose, insulin, C-peptide and triglyceride. Fifty-one participants (age: 35.1 ± 15.6 years; body mass index: 27.7 ± 6.9 kg/m², 17 with normal and 34 with impaired glucose tolerance) completed two meal tests. The area under the curve ( p glucose tolerance group ( p glucose; the red meat/refined grain diet increased glucose relative to the dairy/chicken/nuts/whole grain diet only in the normal group (+2.5 mmol/L/3 h). The red meat/refined grain diet increased glucose and insulin responses compared with the dairy/chicken/nuts/whole grain diet. This meal pattern would increase pancreatic stress long term and may account for the increased risk of type 2 diabetes with this diet.

  5. Differential Effects of Red Meat/Refined Grain Diet and Dairy/Chicken/Nuts/Whole Grain Diet on Glucose, Insulin and Triglyceride in a Randomized Crossover Study

    Directory of Open Access Journals (Sweden)

    Yoona Kim

    2016-10-01

    Full Text Available Epidemiological studies suggest that a diet high in processed meat, with a high glycemic index is associated with an increased risk of type 2 diabetes. It is not clear if this is due to altered insulin sensitivity or an enhanced postprandial glucose. We aimed to compare the acute metabolic response of two different types of meals after ingestion of the matching diet for four weeks. The study was a randomized, crossover acute meal study. Volunteers consumed either a red meat/refined grain meal or a dairy/chicken/nuts/wholegrain meal after four weeks of the matching diet. After a three-week washout period and four weeks of the alternate diet, they consumed the matching meal. The diets differed with respect to both protein and carbohydrate sources. Blood samples were taken for 180 min for the measurement of glucose, insulin, C-peptide and triglyceride. Fifty-one participants (age: 35.1 ± 15.6 years; body mass index: 27.7 ± 6.9 kg/m2, 17 with normal and 34 with impaired glucose tolerance completed two meal tests. The area under the curve (p < 0.001 and incremental area under the curve (p = 0.001 for insulin was significantly higher after the red meat/refined grain diet than after the dairy/chicken/nuts/whole grain diet. There was an interaction between meal and glucose tolerance group (p < 0.05 in the area under the curve (AUC and the incremental area under the curve (iAUC of glucose; the red meat/refined grain diet increased glucose relative to the dairy/chicken/nuts/whole grain diet only in the normal group (+2.5 mmol/L/3 h. The red meat/refined grain diet increased glucose and insulin responses compared with the dairy/chicken/nuts/whole grain diet. This meal pattern would increase pancreatic stress long term and may account for the increased risk of type 2 diabetes with this diet.

  6. Grain-orientation-dependent of γ–ε–α′ transformation and twinning in a super-high-strength, high ductility austenitic Mn-steel

    Energy Technology Data Exchange (ETDEWEB)

    Eskandari, M., E-mail: m.eskandari@scu.ac.ir [Department of Materials Science & Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz (Iran, Islamic Republic of); Zarei-Hanzaki, A. [Hot Deformation & Thermo-mechanical Processing of High Performance Engineering Materials, School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Mohtadi-Bonab, M.A. [Department of Mechanical Engineering, University of Bonab, Velayat Highway (Iran, Islamic Republic of); Onuki, Y. [Frontier Research Center for Applied Atomic Sciences, Ibaraki University (Japan); Basu, R. [Department of Mechanical Engineering, ITM University, Gurgaon (India); Asghari, A. [Electrical and Computer Engineering Department, University of Texas at San Antonio, Texas (United States); Szpunar, J.A. [Advanced Materials for Clean Energy, Department of Mechanical Engineering, University of Saskatchewan (Canada)

    2016-09-30

    A newly developed, austenitic lightweight steel, containing a low-density element, Al, exhibits tensile elongation up to 50% as well as high ultimate-tensile stress (tensile fracture at 1800 MPa) without necking behavior. Electron backscatter diffraction analysis is carried out to investigate the orientation dependence of the martensitic transformation in tensile testing to 30% strain at 323 K (25 °C). A pronounced γ→ε→α′ transformation is observed in <111> and <110>∥TD (TD: tensile direction) γ-grains. The α′-transformation textures is analyzed. Large misorientation spreads is seen in the <100>∥TD γ-grains. Interestingly, twin-assisted martensitic transformation is detected in the <111>∥TD followed by the twin boundary directly moving to a γ/α′ phase boundary. These phenomena are related to a change of Schmid factor for different orientations of grains.

  7. Differential Effects of Red Meat/Refined Grain Diet and Dairy/Chicken/Nuts/Whole Grain Diet on Glucose, Insulin and Triglyceride in a Randomized Crossover Study

    OpenAIRE

    Kim, Yoona; Keogh, Jennifer B.; Clifton, Peter M.

    2016-01-01

    Epidemiological studies suggest that a diet high in processed meat, with a high glycemic index is associated with an increased risk of type 2 diabetes. It is not clear if this is due to altered insulin sensitivity or an enhanced postprandial glucose. We aimed to compare the acute metabolic response of two different types of meals after ingestion of the matching diet for four weeks. The study was a randomized, crossover acute meal study. Volunteers consumed either a red meat/refined grain meal...

  8. Effect of asymmetric hot rolling on texture, microstructure and magnetic properties in a non-grain oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S., E-mail: Shangping.chen@tatasteel.com [Tata Steel, 1970 CA IJmuiden (Netherlands); Butler, J. [Tata Steel, S60 3AR South Yorkshire (United Kingdom); Melzer, S. [Tata Steel, 1970 CA IJmuiden (Netherlands)

    2014-11-15

    In this study, both asymmetric hot rolling (AHR) and conventional hot rolling (CHR) were carried out to study the effect of the hot rolling conditions on the evolution of the texture and microstructure in a non-grain oriented (NGO) steel. The microstructure and texture in the subsequent processing stages were characterised and related to the final magnetic properties. The results show that AHR, compared with CHR, tends to homogenise texture through thickness of the hot band strips. AHR results in a higher fraction of the θ-fibre ({0 0 1}) and a lower fraction of the γ-fibre ({1 1 1}) in the hot band strips, which are favourable features in relation to the magnetic properties of the strip. However, the favourable features observed in hot rolled AHR strips are eliminated after cold rolling and annealing. Contrarily, the required θ-fibre is decreased and the unwanted γ-fibre is intensified in the AHR sheet after cold rolling and their strength is maintained in the subsequent process steps. On the other hand, AHR does not produce a discernible change in the grain size in the hot band annealed strip and in the final annealed sheet, except that the magnetic anisotropy in the AHR is improved after skin pass and extra annealing as the result of the redistribution of the texture components within the θ-fibre, no significant improvement of the magnetic properties as a direct consequence of the application of asymmetric hot rolling has been observed under the current AHR experimental conditions. - Highlights: • Asymmetrical hot rolling (AHR) produces more uniform distribution of texture through the thickness of the hot rolled strips and of the hot band annealed strips when compared with conventional hot rolling (CHR). • AHR results in a higher fraction of the θ-fibre ({0 0 1}) and a lower fraction of the γ-fibre ({1 1 1}) in the hot band strips. The θ-fibre is decreased but the γ-fibre is intensified in the AHR sheet after cold rolling

  9. Effect of asymmetric hot rolling on texture, microstructure and magnetic properties in a non-grain oriented electrical steel

    International Nuclear Information System (INIS)

    Chen, S.; Butler, J.; Melzer, S.

    2014-01-01

    In this study, both asymmetric hot rolling (AHR) and conventional hot rolling (CHR) were carried out to study the effect of the hot rolling conditions on the evolution of the texture and microstructure in a non-grain oriented (NGO) steel. The microstructure and texture in the subsequent processing stages were characterised and related to the final magnetic properties. The results show that AHR, compared with CHR, tends to homogenise texture through thickness of the hot band strips. AHR results in a higher fraction of the θ-fibre ({0 0 1}) and a lower fraction of the γ-fibre ({1 1 1}) in the hot band strips, which are favourable features in relation to the magnetic properties of the strip. However, the favourable features observed in hot rolled AHR strips are eliminated after cold rolling and annealing. Contrarily, the required θ-fibre is decreased and the unwanted γ-fibre is intensified in the AHR sheet after cold rolling and their strength is maintained in the subsequent process steps. On the other hand, AHR does not produce a discernible change in the grain size in the hot band annealed strip and in the final annealed sheet, except that the magnetic anisotropy in the AHR is improved after skin pass and extra annealing as the result of the redistribution of the texture components within the θ-fibre, no significant improvement of the magnetic properties as a direct consequence of the application of asymmetric hot rolling has been observed under the current AHR experimental conditions. - Highlights: • Asymmetrical hot rolling (AHR) produces more uniform distribution of texture through the thickness of the hot rolled strips and of the hot band annealed strips when compared with conventional hot rolling (CHR). • AHR results in a higher fraction of the θ-fibre ({0 0 1}) and a lower fraction of the γ-fibre ({1 1 1}) in the hot band strips. The θ-fibre is decreased but the γ-fibre is intensified in the AHR sheet after cold rolling

  10. On Techniques to Characterize and Correlate Grain Size, Grain Boundary Orientation and the Strength of the SiC Layer of TRISO Coated Particles: A Preliminary Study

    Energy Technology Data Exchange (ETDEWEB)

    I.J.van Rooyen; J.L. Dunzik Gougar; T. Trowbridge; Philip M van Rooyen

    2012-10-01

    The mechanical properties of the silicon carbide (SiC) layer of the TRi-ISOtropic (TRISO) coated particle (CP) for high temperature gas reactors (HTGR) are performance parameters that have not yet been standardized by the international HTR community. Presented in this paper are the results of characterizing coated particles to reveal the effect of annealing temperature (1000 to 2100°C) on the strength and grain size of unirradiated coated particles. This work was further expanded to include possible relationships between the grain size and strength values. The comparative results of two strength measurement techniques and grain size measured by the Lineal intercept method are included. Preliminary grain boundary characterization results determined by electron backscatter diffraction (EBSD) are included. These results are also important for future fission product transport studies, as grain boundary diffusion is identified as a possible mechanism by which 110mAg, one of the fission activation products, might be released through intact SiC layers. Temperature is a parameter known to influence the grain size of SiC and therefore it is important to investigate the effect of high temperature annealing on the SiC grain size. Recommendations and future work will also be briefly discussed.

  11. Electroless Co–P-Carbon Nanotube composite coating to enhance magnetic properties of grain-oriented electrical steel

    International Nuclear Information System (INIS)

    Goel, Vishu; Anderson, Philip; Hall, Jeremy; Robinson, Fiona; Bohm, Siva

    2016-01-01

    The effect of Co–P-CNT coating on the magnetic properties of grain oriented electrical steel was investigated. To analyse the coating, Raman spectroscopy, Superconducting QUantum Interference Device (SQUID), single strip testing, Scanning Electron Microscopy (SEM) and talysurf surface profilometry were performed. Raman spectra showed the D and G band which corroborates the presence of Multi-Walled Carbon Nanotubes (MWCNT) in the coating. The magnetic nature of the coating was confirmed by SQUID results. Power loss results show an improvement ranging 13–15% after coating with Co–P-CNT. The resistivity of the coating was measured to be 10 4 µΩ cm. Loss separation graphs were plotted before and after coating to study the improvement in power loss. It was found that the coating helps in reducing the hysteresis loss. The thickness of the coating was found to be 414±40 nm. The surface profilometry results showed that the surface roughness improved after coating the sample. - Highlights: • Co–P-CNT coating on Fe–3%Si steel was able to reduce the power loss by 13–15%. • Co–P-CNT coating reduced the surface roughness and enhanced the magnetic properties. • The decrease in coating thickness increased the stacking factor. • The stacking factor was further improved by the magnetic nature of the coating.

  12. CrAlN coating to enhance the power loss and magnetostriction in grain oriented electrical steel

    Directory of Open Access Journals (Sweden)

    Vishu Goel

    2016-05-01

    Full Text Available Grain oriented electrical steels (GOES are coated with aluminium orthophosphate on top of a forsterite (Mg2SiO4 layer to provide stress and insulation resistance to reduce the power loss and magnetostriction. In this work Chromium Aluminium Nitride (CrAlN was coated on GOES samples with electron beam physical vapour deposition and was tested in the single strip and magnetostriction tester to measure the power loss and magnetostriction before and after coating. Power loss was reduced by 2% after coating and 6 % post annealing at 800 °C. For applied compressive stress of 6 MPa, the magnetostrictive strain was zero with the CrAlN coating as compared to 22 and 24 μϵ for fully finished GOES and GOES without phosphate coating. The thickness of the coating was found to be 1.9 ± 0.2 μm estimated with Glow Discharge Optical Emission Spectroscopy (GDOES. The magnetic domain imaging showed domain narrowing after coating. The reduction in power loss and magnetostriction was due to the large residual compressive stress and Young’s modulus (270 GPa of the coating.

  13. CrAlN coating to enhance the power loss and magnetostriction in grain oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Goel, Vishu; Anderson, Philip; Hall, Jeremy [Wolfson Centre for Magnetics, Cardiff University, Cardiff- CF243AA (United Kingdom); Robinson, Fiona [Cogent power Ltd., Newport-NP190RB (United Kingdom); Bohm, Siva [Dept. of metallurgical engineering & materials science, IIT Bombay, Mumbai-400076 (India)

    2016-05-15

    Grain oriented electrical steels (GOES) are coated with aluminium orthophosphate on top of a forsterite (Mg{sub 2}SiO{sub 4}) layer to provide stress and insulation resistance to reduce the power loss and magnetostriction. In this work Chromium Aluminium Nitride (CrAlN) was coated on GOES samples with electron beam physical vapour deposition and was tested in the single strip and magnetostriction tester to measure the power loss and magnetostriction before and after coating. Power loss was reduced by 2% after coating and 6 % post annealing at 800 °C. For applied compressive stress of 6 MPa, the magnetostrictive strain was zero with the CrAlN coating as compared to 22 and 24 μϵ for fully finished GOES and GOES without phosphate coating. The thickness of the coating was found to be 1.9 ± 0.2 μm estimated with Glow Discharge Optical Emission Spectroscopy (GDOES). The magnetic domain imaging showed domain narrowing after coating. The reduction in power loss and magnetostriction was due to the large residual compressive stress and Young’s modulus (270 GPa) of the coating.

  14. Orthogonal decomposition of core loss along rolling and transverse directions of non-grain oriented silicon steels

    Directory of Open Access Journals (Sweden)

    Xuezhi Wan

    2017-05-01

    Full Text Available Rotational core loss of the silicon steel laminations are measured under elliptical rotating excitation. The core loss decomposition model is very important in magnetic core design, in which the decomposition coefficients are calculated through the measurement data. By using the transformation of trigonometric function, the elliptical rotational magnetic flux can be decomposed into two parts along two directions. It is assumed that the rotating core loss is the sum of alternating core losses along rolling and transverse directions. The magnetic strength vector H of non-grain oriented (NGO silicon steel 35WW270 along rolling and transverse directions is measured by a novel designed 3-D magnetic properties tester. Alternating core loss along the rolling, transverse directions and rotating core loss in the xoy-plane of this specimen in different frequencies such as 50 Hz, 100 Hz, and 200 Hz. Experimental results show that the core loss model is more accurate and useful to predict the total core loss.

  15. Electroless Co–P-Carbon Nanotube composite coating to enhance magnetic properties of grain-oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Goel, Vishu, E-mail: vishu.goel.nit@gmail.com [Wolfson Centre for Magnetics, Cardiff University, Cardiff CF243AA (United Kingdom); Anderson, Philip, E-mail: AndersonPI1@cf.ac.uk [Wolfson Centre for Magnetics, Cardiff University, Cardiff CF243AA (United Kingdom); Hall, Jeremy, E-mail: HallJP@cf.ac.uk [Wolfson Centre for Magnetics, Cardiff University, Cardiff CF243AA (United Kingdom); Robinson, Fiona, E-mail: fiona.cj.robinson@tatasteel.com [Cogent power Ltd., Newport NP19 0RB (United Kingdom); Bohm, Siva, E-mail: siva.bohm@tatasteel.com [IIT Bombay, Mumbai 400076 (India)

    2016-06-01

    The effect of Co–P-CNT coating on the magnetic properties of grain oriented electrical steel was investigated. To analyse the coating, Raman spectroscopy, Superconducting QUantum Interference Device (SQUID), single strip testing, Scanning Electron Microscopy (SEM) and talysurf surface profilometry were performed. Raman spectra showed the D and G band which corroborates the presence of Multi-Walled Carbon Nanotubes (MWCNT) in the coating. The magnetic nature of the coating was confirmed by SQUID results. Power loss results show an improvement ranging 13–15% after coating with Co–P-CNT. The resistivity of the coating was measured to be 10{sup 4} µΩ cm. Loss separation graphs were plotted before and after coating to study the improvement in power loss. It was found that the coating helps in reducing the hysteresis loss. The thickness of the coating was found to be 414±40 nm. The surface profilometry results showed that the surface roughness improved after coating the sample. - Highlights: • Co–P-CNT coating on Fe–3%Si steel was able to reduce the power loss by 13–15%. • Co–P-CNT coating reduced the surface roughness and enhanced the magnetic properties. • The decrease in coating thickness increased the stacking factor. • The stacking factor was further improved by the magnetic nature of the coating.

  16. In situ neutron diffraction study of grain-orientation-dependent phase transformation in 304L stainless steel at a cryogenic temperature

    International Nuclear Information System (INIS)

    Tao Kaixiang; Wall, James J.; Li, Hongqi; Brown, Donald W.; Vogel, Sven C.; Choo, Hahn

    2006-01-01

    In situ time-of-flight neutron diffraction was performed to investigate the martensitic phase transformation during quasistatic uniaxial compression testing of 304L stainless steel at 300 and 203 K. In situ neutron diffraction enabled the bulk measurement of intensity evolution for various hkl atomic planes during the austenite (fcc) to martensite (hcp and bcc) phase transformation. Based on the neutron diffraction patterns, the martensite phases were observed from the very beginning of the plastic deformation at 203 K. However, at 300 K, no newly formed martensite, except a small amount of preexisting hcp phase, was observed throughout the test. From the changes in the relative intensities of individual hkl atomic planes, the grain-orientation-dependent phase transformation was investigated. The preferred orientation of the newly formed martensite grains was also investigated for the sample deformed at 203 K using neutron diffraction. The results reveal the orientation relationships between the austenite and the newly formed martensites. The fcc grain family diffracting with (200) plane normal parallel to the loading axis is favored for the fcc to bcc transformation and the bcc (200) plane normals are primarily aligned along the loading direction. For the fcc to hcp transformation, the fcc grains with (111) plane normals at an angle in between about 10 deg. and 50 deg. to the loading direction are favored

  17. Microstructure and texture evolution of ultra-thin grain-oriented silicon steel sheet fabricated using strip casting and three-stage cold rolling method

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hong-Yu; Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn; Wang, Yin-Ping; Wang, Guo-Dong

    2017-03-15

    A 0.1 mm-thick grain-oriented silicon steel sheet was successfully produced using strip casting and three-stage cold rolling method. The microstructure, texture and inhibitor evolution during the processing was briefly analyzed. It was found that Goss texture was absent in the hot rolled sheet because of the lack of shear deformation. After normalizing, a large number of dispersed MnS precipitates with the size range of 15–90 nm were produced. During first cold rolling, dense shear bands were generated in the deformed ferrite grains, resulting in the intense Goss texture after first intermediate annealing. The microstructure was further refined and homogenized during the subsequent cold rolling and annealing processes. After primary recrystallization annealing, a homogeneous microstructure consisting of fine and equiaxed grains was produced while the associated texture was characterized by a strong γ-fiber texture. Finally, a complete secondary recrystallization microstructure consisting of entirely large Goss grains was produced. The magnetic induction B{sub 8} and iron loss P{sub 10/400} was 1.79 T and 6.9 W/kg, respectively. - Highlights: • Ultra-thin grain-oriented silicon steel was produced by strip casting process. • Microstructure, texture and inhibitor evolution was briefly investigated. • Goss texture was absent in primary recrystallization annealed sheet. • MnS precipitates with a size range of 15–90 nm formed after normalizing. • A complete secondary recrystallization microstructure was produced.

  18. Microwave single-scattering properties of randomly oriented soft-ice hydrometeors

    Directory of Open Access Journals (Sweden)

    D. Casella

    2008-11-01

    Full Text Available Large ice hydrometeors are usually present in intense convective clouds and may significantly affect the upwelling radiances that are measured by satellite-borne microwave radiometers – especially, at millimeter-wavelength frequencies. Thus, interpretation of these measurements (e.g., for precipitation retrieval requires knowledge of the single scattering properties of ice particles. On the other hand, shape and internal structure of these particles (especially, the larger ones is very complex and variable, and therefore it is necessary to resort to simplifying assumptions in order to compute their single-scattering parameters.

    In this study, we use the discrete dipole approximation (DDA to compute the absorption and scattering efficiencies and the asymmetry factor of two kinds of quasi-spherical and non-homogeneous soft-ice particles in the frequency range 50–183 GHz. Particles of the first kind are modeled as quasi-spherical ice particles having randomly distributed spherical air inclusions. Particles of the second kind are modeled as random aggregates of ice spheres having random radii. In both cases, particle densities and dimensions are coherent with the snow hydrometeor category that is utilized by the University of Wisconsin – Non-hydrostatic Modeling System (UW-NMS cloud-mesoscale model. Then, we compare our single-scattering results for randomly-oriented soft-ice hydrometeors with corresponding ones that make use of: a effective-medium equivalent spheres, b solid-ice equivalent spheres, and c randomly-oriented aggregates of ice cylinders. Finally, we extend to our particles the scattering formulas that have been developed by other authors for randomly-oriented aggregates of ice cylinders.

  19. Macroscopic optical constants of a cloud of randomly oriented nonspherical scatterers

    International Nuclear Information System (INIS)

    Borghese, F.; Denti, P.; Saija, R.; Toscano, G.; Sindoni, O.I.

    1984-01-01

    A method to calculate the macroscopic optical constants of a low-density medium consisting of a cloud of identical nonspherical scatterers is presented. The scatterers in the medium are clusters of dielectric spheres and the electromagnetic field scattered by each of the clusters is obtained as a superposition of multipole fields, as previously proposed by the authors. The transformation properties of the spherical multipoles under rotation allow the orientation-dependent terms in the expression for the forward-scattering amplitude of each of the clusters to be factored out. In this way the sum of the scattering amplitudes of the clusters with different orientations, needed to calculate the optical response of the medium, is greatly facilitated and admits a simple analytic expression in the case of randomly oriented clusters. Results of calculations of the optical constants for a few model media are presented

  20. Graded index and randomly oriented core-shell silicon nanowires for broadband and wide angle antireflection

    Directory of Open Access Journals (Sweden)

    P. Pignalosa

    2011-09-01

    Full Text Available Antireflection with broadband and wide angle properties is important for a wide range of applications on photovoltaic cells and display. The SiOx shell layer provides a natural antireflection from air to the Si core absorption layer. In this work, we have demonstrated the random core-shell silicon nanowires with both broadband (from 400nm to 900nm and wide angle (from normal incidence to 60º antireflection characteristics within AM1.5 solar spectrum. The graded index structure from the randomly oriented core-shell (Air/SiOx/Si nanowires may provide a potential avenue to realize a broadband and wide angle antireflection layer.

  1. Multitrait, Random Regression, or Simple Repeatability Model in High-Throughput Phenotyping Data Improve Genomic Prediction for Wheat Grain Yield.

    Science.gov (United States)

    Sun, Jin; Rutkoski, Jessica E; Poland, Jesse A; Crossa, José; Jannink, Jean-Luc; Sorrells, Mark E

    2017-07-01

    High-throughput phenotyping (HTP) platforms can be used to measure traits that are genetically correlated with wheat ( L.) grain yield across time. Incorporating such secondary traits in the multivariate pedigree and genomic prediction models would be desirable to improve indirect selection for grain yield. In this study, we evaluated three statistical models, simple repeatability (SR), multitrait (MT), and random regression (RR), for the longitudinal data of secondary traits and compared the impact of the proposed models for secondary traits on their predictive abilities for grain yield. Grain yield and secondary traits, canopy temperature (CT) and normalized difference vegetation index (NDVI), were collected in five diverse environments for 557 wheat lines with available pedigree and genomic information. A two-stage analysis was applied for pedigree and genomic selection (GS). First, secondary traits were fitted by SR, MT, or RR models, separately, within each environment. Then, best linear unbiased predictions (BLUPs) of secondary traits from the above models were used in the multivariate prediction models to compare predictive abilities for grain yield. Predictive ability was substantially improved by 70%, on average, from multivariate pedigree and genomic models when including secondary traits in both training and test populations. Additionally, (i) predictive abilities slightly varied for MT, RR, or SR models in this data set, (ii) results indicated that including BLUPs of secondary traits from the MT model was the best in severe drought, and (iii) the RR model was slightly better than SR and MT models under drought environment. Copyright © 2017 Crop Science Society of America.

  2. Influence of initial heating during final high temperature annealing on the offset of primary and secondary recrystallization in Cu-bearing grain oriented electrical steels

    Science.gov (United States)

    Rodriguez-Calvillo, P.; Leunis, E.; Van De Putte, T.; Jacobs, S.; Zacek, O.; Saikaly, W.

    2018-04-01

    The industrial production route of Grain Oriented Electrical Steels (GOES) is complex and fine-tuned for each grade. Its metallurgical process requires in all cases the abnormal grain growth (AGG) of the Goss orientation during the final high temperature annealing (HTA). The exact mechanism of AGG is not yet fully understood, but is controlled by the different inhibition systems, namely MnS, AlN and CuxS, their size and distribution, and the initial primary recrystallized grain size. Therefore, among other parameters, the initial heating stage during the HTA is crucial for the proper development of primary and secondary recrystallized microstructures. Cold rolled 0.3 mm Cu-bearing Grain Oriented Electrical Steel has been submitted to interrupted annealing experiments in a lab tubular furnace. Two different annealing cycles were applied:• Constant heating at 30°C/h up to 1000°C. Two step cycle with initial heating at 100°C/h up to 600°C, followed by 18 h soaking at 600°C and then heating at 30°C/h up to 1050°C. The materials are analyzed in terms of their magnetic properties, grain size, texture and precipitates. The characteristic magnetic properties are analyzed for the different extraction temperatures and Cycles. As the annealing was progressing, the coercivity values (Hc 1.7T [A/m]) decreased, showing two abrupt drops, which can be associated to the on-set of primary and secondary recrystallization. The primary recrystallized grain sizes and recrystallized fractions are fitted to a model using a non-isothermal approach. This analysis shows that, although the resulting grain sizes were similar, the kinetics for the two step annealing were faster due to the lower recovery. The on-set of secondary recrystallization was also shifted to higher temperatures in the case of the continuous heating cycle, which might end in different final grain sizes and final magnetic properties. In both samples, nearly all the observed precipitates are Al-Si-Mn nitrides

  3. Influence of initial heating during final high temperature annealing on the offset of primary and secondary recrystallization in Cu-bearing grain oriented electrical steels

    Directory of Open Access Journals (Sweden)

    P. Rodriguez-Calvillo

    2018-04-01

    Full Text Available The industrial production route of Grain Oriented Electrical Steels (GOES is complex and fine-tuned for each grade. Its metallurgical process requires in all cases the abnormal grain growth (AGG of the Goss orientation during the final high temperature annealing (HTA. The exact mechanism of AGG is not yet fully understood, but is controlled by the different inhibition systems, namely MnS, AlN and CuxS, their size and distribution, and the initial primary recrystallized grain size. Therefore, among other parameters, the initial heating stage during the HTA is crucial for the proper development of primary and secondary recrystallized microstructures. Cold rolled 0.3 mm Cu-bearing Grain Oriented Electrical Steel has been submitted to interrupted annealing experiments in a lab tubular furnace. Two different annealing cycles were applied:• Constant heating at 30°C/h up to 1000°C. Two step cycle with initial heating at 100°C/h up to 600°C, followed by 18 h soaking at 600°C and then heating at 30°C/h up to 1050°C. The materials are analyzed in terms of their magnetic properties, grain size, texture and precipitates. The characteristic magnetic properties are analyzed for the different extraction temperatures and Cycles. As the annealing was progressing, the coercivity values (Hc 1.7T [A/m] decreased, showing two abrupt drops, which can be associated to the on-set of primary and secondary recrystallization. The primary recrystallized grain sizes and recrystallized fractions are fitted to a model using a non-isothermal approach. This analysis shows that, although the resulting grain sizes were similar, the kinetics for the two step annealing were faster due to the lower recovery. The on-set of secondary recrystallization was also shifted to higher temperatures in the case of the continuous heating cycle, which might end in different final grain sizes and final magnetic properties. In both samples, nearly all the observed precipitates are Al

  4. Distribution of orientation selectivity in recurrent networks of spiking neurons with different random topologies.

    Science.gov (United States)

    Sadeh, Sadra; Rotter, Stefan

    2014-01-01

    Neurons in the primary visual cortex are more or less selective for the orientation of a light bar used for stimulation. A broad distribution of individual grades of orientation selectivity has in fact been reported in all species. A possible reason for emergence of broad distributions is the recurrent network within which the stimulus is being processed. Here we compute the distribution of orientation selectivity in randomly connected model networks that are equipped with different spatial patterns of connectivity. We show that, for a wide variety of connectivity patterns, a linear theory based on firing rates accurately approximates the outcome of direct numerical simulations of networks of spiking neurons. Distance dependent connectivity in networks with a more biologically realistic structure does not compromise our linear analysis, as long as the linearized dynamics, and hence the uniform asynchronous irregular activity state, remain stable. We conclude that linear mechanisms of stimulus processing are indeed responsible for the emergence of orientation selectivity and its distribution in recurrent networks with functionally heterogeneous synaptic connectivity.

  5. Effects of Whole Grain Wheat Bread on Visceral Fat Obesity in Japanese Subjects: A Randomized Double-Blind Study.

    Science.gov (United States)

    Kikuchi, Yosuke; Nozaki, Satomi; Makita, Miki; Yokozuka, Shoji; Fukudome, Shin-Ichi; Yanagisawa, Takashi; Aoe, Seiichiro

    2018-04-18

    Metabolic syndrome is a risk factor for cardiovascular diseases and has become increasingly common in Japan. Epidemiological studies show inverse associations between intake of whole wheat grains and metabolic syndrome, but few dietary intervention trials have investigated the effect of whole wheat grain consumption. It was investigated whether a diet in which refined wheat bread (RW diet) was substituted by whole grain wheat bread (WW diet) would reduce visceral fat obesity in Japanese subjects. A randomized double-blind placebo-controlled intervention study was conducted in 50 Japanese subjects with body mass index (BMI) ≥ 23 kg/m 2 . Subjects were randomly assigned WW (WW group) or RW diets (RW group) for 12 weeks. Blood samples and computed tomography scans were obtained every 6th week. The WW group showed decrease (-4 cm 2 ) in visceral fat area (VFA) (p < 0.05), whereas the RW group showed no significant changes. These time-dependent changes were significantly different between the groups. WW diet led to significant and safe reductions in VFA in subjects with BMI ≥ 23 kg/m 2 . WW diet may contribute to preventing visceral fat obesity.

  6. Current distributions in superconducting wires subject to a random orientation magnetic field, and corresponding to the Tokamak usual conditions

    International Nuclear Information System (INIS)

    Artaud, J.F.

    1994-01-01

    The main themes of this thesis are: review of superconductivity principles; critical current in a random orientation magnetic field; the MHD model applied to superconductors (with comprehensive calculation of the field in a plate type conductor); the magnetization created by a variation of a random orientation magnetic field; the electric field in a superconductor in steady or quasi-steady state (MHD displacement, pinning and thermal effects). 145 figs., 166 refs

  7. Blocking of grain reorientation in self-doped alumina materials

    International Nuclear Information System (INIS)

    Suarez, M.; Fernandez, A.; Menendez, J.L.; Ramirez-Rico, J.; Torrecillas, R.

    2011-01-01

    Alumina nanoparticles 10-20 nm in diameter were nucleated on alumina particles, 150 nm average diameter, by a colloidal route followed by calcination. It is shown that after sintering, the final grain size is up to 20% smaller due to the addition of the alumina nanoparticles. Electron backscattered diffraction analysis shows that whereas a correlation in the relative crystalline orientations between neighbouring grains exists in the pure materials, the addition of alumina nanoparticles results in a random crystalline orientation.

  8. Influence of grain orientation on evolution of surface features in fatigued polycrystalline copper: A comparison of thermal and uniaxial mechanical fatigue results

    International Nuclear Information System (INIS)

    Aicheler, Markus

    2010-01-01

    Surface state plays a major role in the crack nucleation process of pure metals in the High-Cycle-Fatigue (HCF) as well as in the Ultra-High-Cycle-Fatigue (UHCF) regime. Therefore, in studies dealing with HCF or UHCF, special attention is paid to the evolution of surface degradation during fatigue life. The accelerating structures of the future Compact Linear Collider (CLIC) under study at CERN will be submitted to a high number of thermal-mechanical fatigue cycles, arising from Radio Frequency (RF) induced eddy currents, causing local superficial cyclic heating. The number of cycles during the foreseen lifetime of CLIC reaches 2x10 11 . Fatigue may limit the lifetime of CLIC structures. In order to assess the effects of superficial fatigue, specific tests are defined and performed on polycrystalline Oxygen Free Electronic (OFE) grade Copper, a candidate material for the structures. Surface degradation depends on the orientation of near-surface grains. Copper samples thermally fatigued in two different fatigue experiments, pulsed laser and pulsed RF-heating, underwent postmortem Electron Backscattered Diffraction measurements. Samples fatigued by pulsed laser show the same trend in the orientation-fatigue damage behavior as samples fatigued by pulsed RF-heating. It is clearly observed that surface grains, oriented [1 1 1] with respect to the surface, show significantly more damage than surface grains oriented [1 0 0]. Results arising from a third fatigue experiment, the ultrasound (US) swinger, are compared to the results of the mentioned experiments. The US swinger is an uniaxial mechanical fatigue test enabling to apply within several days a total number of cycles representative of the life of the CLIC structures, thanks to a high repetition rate of 24 kHz. For comparison, laser fatigue experiments have much lower repetition rates. The dependence of surface degradation on grain orientation of samples tested by the US swinger was monitored during the fatigue life

  9. Effect of NICU Department Orientation Program on Mother’s Anxiety: a Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Leila Valizadeh

    2016-09-01

    Full Text Available Introduction: Neonatal intensive care unit induces the high level of anxiety for mothers. The aim of this study was to evaluate the effectiveness of NICU orientation program on the anxiety of mothers who had preterm newborns hospitalized in NICU. Methods: This study was a randomized clinical trial (three parallel groups. Participants included 99 mothers with preterm newborns hospitalized in NICU of Al- Zahra hospital, affiliated to Tabriz University of Medical Sciences in 2015. Mothers were randomly assigned to one of three groups (film, booklet, and control. Mothers completed the State- Trait Anxiety Inventory before entering to the NICU, and then mothers in the experiment groups became familiar with the NICU environment through watching a film or reading booklet. After the first NICU visit, all mothers completed the STAI and Cattell's Anxiety Questionnaires. Data were analyzed using SPSS ver. 13 software. Results: There was no significant difference between three groups regarding state- trait anxiety before the intervention. After the first NICU visit, a significant reduction in maternal state anxiety was seen in the both experiment groups. There was no statistical significant difference regarding trait anxiety. Data obtained from Cattell's anxiety questionnaire after intervention, showed significant difference in state anxiety between groups. Conclusion: Employing film and booklet orientation strategy after preterm delivery can reduce the mother’s anxiety and beneficent for the mother, baby, family and health care system.

  10. Performance of Novel Randomly Oriented High Graphene Carbon in Lithium Ion Capacitors

    Directory of Open Access Journals (Sweden)

    Rahul S. Kadam

    2018-01-01

    Full Text Available The structure of carbon material comprising the anode is the key to the performance of a lithium ion capacitor. In addition to determining the capacity, the structure of the carbon material also determines the diffusion rate of the lithium ion into the anode which in turn controls power density which is vital in high rate applications. This paper covers details of systematic investigation of the performance of a structurally novel carbon, called Randomly Oriented High Graphene (ROHG carbon, and graphite in a high rate application device, that is, lithium ion capacitor. Electrochemical impedance spectroscopy shows that ROHG is less resistive and has faster lithium ion diffusion rates (393.7 × 10−3 S·s(1/2 compared to graphite (338.1 × 10−3 S·s(1/2. The impedance spectroscopy data is supported by the cell data showing that the ROHG carbon based device has energy density of 22.8 Wh/l with a power density of 4349.3 W/l, whereas baseline graphite based device has energy density of 5 Wh/l and power density of 4243.3 W/l. This data clearly shows advantage of the randomly oriented graphene platelet structure of ROHG in lithium ion capacitor performance.

  11. Real-Space x-ray tomographic reconstruction of randomly oriented objects with sparse data frames.

    Science.gov (United States)

    Ayyer, Kartik; Philipp, Hugh T; Tate, Mark W; Elser, Veit; Gruner, Sol M

    2014-02-10

    Schemes for X-ray imaging single protein molecules using new x-ray sources, like x-ray free electron lasers (XFELs), require processing many frames of data that are obtained by taking temporally short snapshots of identical molecules, each with a random and unknown orientation. Due to the small size of the molecules and short exposure times, average signal levels of much less than 1 photon/pixel/frame are expected, much too low to be processed using standard methods. One approach to process the data is to use statistical methods developed in the EMC algorithm (Loh & Elser, Phys. Rev. E, 2009) which processes the data set as a whole. In this paper we apply this method to a real-space tomographic reconstruction using sparse frames of data (below 10(-2) photons/pixel/frame) obtained by performing x-ray transmission measurements of a low-contrast, randomly-oriented object. This extends the work by Philipp et al. (Optics Express, 2012) to three dimensions and is one step closer to the single molecule reconstruction problem.

  12. The production of grain oriented lanthanum titanate (La2Ti2O7) ceramics by uniaxial hot-forging process for improved fracture toughness

    International Nuclear Information System (INIS)

    Ceylan, Ali

    2008-01-01

    The layered-structural ceramics, such as lanthanum titanate (La 2 Ti 2 O 7 ), have been known for their good electrical and optical properties at high frequencies and temperatures. However, few studies have been conducted on the mechanical properties of these ceramics. The interest in ceramic hot-forging (HF) has been greatly increased recently due to the enhancement in fracture toughness via bridging effect of oriented grains. In this study, grain oriented lanthanum titanate was produced by the hot-forging process. The characterizations of the samples were achieved by density measurement, scanning electron microscopy (SEM), optical microscopy, X-ray diffraction (XRD), Vickers indentation and three-point bending test. According to X-ray diffraction patterns, the orientation factor (f) was found to be 0.73 for certain hot-forging conditions resulting an improved fracture toughness. The improved fracture toughness of La 2 Ti 2 O 7 (3.2 MPa m 1/2 ) reached to the value of monolithic alumina (Al 2 O 3 ) between 3 and 4 MPa m 1/2

  13. Photoionization cross-section for atomic orbitals with random and fixed spatial orientation

    International Nuclear Information System (INIS)

    Goldberg, S.M.; Fadley, C.S.; Kono, S.

    1981-01-01

    Atomic photoionization subshell cross-sections and asymmetry parameters necessary for determining the differential cross-sections of randomly-oriented atoms have been calculated within the one-electron, central-potential model and the dipole approximation for all subshells of C, O, Al, Si, S, Ni, Cu, Ga, Ge, As, Se, In, Sb, Cs, Ba, Ce, Ta, W, Pt, Au, and Pb for a photon energy range from 20 to 1500 eV, and the relevant Cooper minima located to within 10 eV. These values are tabulated for general use, together with the associated radial matrix elements and phase shifts. Differential photoionization cross-sections for fixed-orientation s-, p- and d-orbitals have also been derived within the same model for a completely general experimental geometry, and closed-form expressions depending on radial matrix elements and phase shifts are given. For the special geometry of a polarized excitation source with polarization parallel to the electron emission direction, it is further shown that such oriented-atom cross-sections are exactly proportional to the probability distribution of the initial orbital, a result equivalent to that derived by using a plane-wave final-state approximation. However, detailed numerical calculations of cross-sections for oriented Cu 3d and O 2p orbitals in various general geometries and at various energies exhibit significant differences in comparison to plane-wave cross-sections. By contrast, certain prior angular-resolved X-ray photoemission studies of single-crystal valence bands are found to have been carried out in an experimental geometry that fortuitously gave cross-sections close to the plane-wave predictions. (orig.)

  14. Effect of Grain Orientation and Boundary Distributions on Hydrogen-Induced Cracking in Low-Carbon-Content Steels

    Science.gov (United States)

    Masoumi, Mohammad; Coelho, Hana Livia Frota; Tavares, Sérgio Souto Maior; Silva, Cleiton Carvalho; de Abreu, Hamilton Ferreira Gomes

    2017-08-01

    Hydrogen-induced cracking (HIC) causes considerable economic losses in a wide range of steels exposed to corrosive environments. The effect of crystallographic texture and grain boundary distributions tailored by rolling at 850 °C in three different steels with a body-centered cube structure was investigated on HIC resistance. The x-ray and electron backscattered diffraction techniques were used to characterize texture evolutions during the rolling process. The findings revealed a significant improvement against HIC based on texture engineering. In addition, increasing the number of {111} and {110} grains, associated with minimizing the number of {001} grains in warm-rolled samples, reduced HIC susceptibility. Moreover, the results showed that boundaries associated with low {hkl} indexing and denser packing planes had more resistance against crack propagation.

  15. Dielectric, piezoelectric, and ferroelectric properties of grain-orientated Bi3.25La0.75Ti3O12 ceramics

    International Nuclear Information System (INIS)

    Liu Jing; Shen Zhijian; Yan Haixue; Reece, Michael J.; Kan Yanmei; Wang Peiling

    2007-01-01

    By dynamic forging during Spark Plasma Sintering (SPS), grain-orientated ferroelectric Bi 3.25 La 0.75 Ti 3 O 12 (BLT) ceramics were prepared. Their ferroelectric, piezoelectric, and dielectric properties are anisotropic. The textured ceramics parallel and perpendicular to the shear flow directions have similar thermal depoling behaviors. The d 33 piezoelectric coefficient of BLT ceramics gradually reduces up to 350 deg. C; it then drops rapidly. The broadness of the dielectric constant and loss peaks and the existence of d 33 above the permittivity peak, T m , show that the BLT ceramic has relaxor-like behavior

  16. Guiding the orientation of smooth muscle cells on random and aligned polyurethane/collagen nanofibers.

    Science.gov (United States)

    Jia, Lin; Prabhakaran, Molamma P; Qin, Xiaohong; Ramakrishna, Seeram

    2014-09-01

    Fabricating scaffolds that can simulate the architecture and functionality of native extracellular matrix is a huge challenge in vascular tissue engineering. Various kinds of materials are engineered via nano-technological approaches to meet the current challenges in vascular tissue regeneration. During this study, nanofibers from pure polyurethane and hybrid polyurethane/collagen in two different morphologies (random and aligned) and in three different ratios of polyurethane:collagen (75:25; 50:50; 25:75) are fabricated by electrospinning. The fiber diameters of the nanofibrous scaffolds are in the range of 174-453 nm and 145-419 for random and aligned fibers, respectively, where they closely mimic the nanoscale dimensions of native extracellular matrix. The aligned polyurethane/collagen nanofibers expressed anisotropic wettability with mechanical properties which is suitable for regeneration of the artery. After 12 days of human aortic smooth muscle cells culture on different scaffolds, the proliferation of smooth muscle cells on hybrid polyurethane/collagen (3:1) nanofibers was 173% and 212% higher than on pure polyurethane scaffolds for random and aligned scaffolds, respectively. The results of cell morphology and protein staining showed that the aligned polyurethane/collagen (3:1) scaffold promote smooth muscle cells alignment through contact guidance, while the random polyurethane/collagen (3:1) also guided cell orientation most probably due to the inherent biochemical composition. Our studies demonstrate the potential of aligned and random polyurethane/collagen (3:1) as promising substrates for vascular tissue regeneration. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  17. Orientation dependence of grain-boundary energy in metals in the view of a pseudoheterophase dislocation core model

    International Nuclear Information System (INIS)

    Missol, W.

    1976-01-01

    A new dislocation model for symmetric tilt grain boundaries was developed as a basis for deriving the quantitative dependence of grain-boundary energy upon misorientation angle in the form of an expression similar to that given by Read and Shockley [Phys. Rev. 78: 275(1950)]. The range of applicability of this equation was extended to over 20 degrees. A comparison of theory and experiment was made for Bi, Ag, Cu, and Fe--Si 3 percent in the teen-degree range of misorientation angles and for Au, α-Fe, Mo, and W in the high-angle range

  18. A Study on the Effects on Low Cycle Fatigue Life of a High Pressure Turbine Nozzle due to the Perturbation of Crystal Orientation of Grain of DS Materials

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Jae Sung; Kang, Young Seok; Rhee, Dong Ho [Korea Aerospace Research Institute, Daejeon (Korea, Republic of)

    2016-07-15

    High pressure components of a gas turbine engine are generally made of nickel-base superalloys, using precision casting process due to complicated geometries with intricate channels and cooling holes. Turbine components manufactured from directionally solidified and single crystal materials have columnar grains; however, it is found that the crystals do not grow in its preferred direction, although the orientation can be controlled. This anisotropy can lead to the variations of elastic and Hill's parameters in constitutive equations, and they alter stress distributions and the low cycle fatigue life. We aims to evaluate the effects of perturbed crystal orientations on the structural integrity of a directionally solidified nozzle using low cycle fatigue life. We also attempt to show the necessity for the control of allowed manufacturing errors and stochastic analysis. Our approaches included conjugate heat transfer and structural analysis, along with low cycle fatigue life assessment.

  19. Application of Electron Backscattered Diffraction (EBSD) and Atomic Force Microscopy (AFM) to Determine Texture, Mesotexture, and Grain Boundary Energies in Ceramics

    International Nuclear Information System (INIS)

    Glass, S.J.; Rohrer, G.S.; Saylor, D.M.; Vedula, V.R.

    1999-01-01

    Crystallographic orientations in alumina (Al 2 0 3 ) and magnesium aluminate spinel (MgAl 2 0 4 ) were obtained using electron backscattered diffraction (EBSD) patterns. The texture and mesotexture (grain boundary mis-orientations) were random and no special boundaries were observed. The relative grain boundary energies were determined by thermal groove geometries using atomic force microscopy (AFM) to identify relationships between the grain boundary energies and mis-orientations

  20. Strain hardening behavior and microstructural evolution during plastic deformation of dual phase, non-grain oriented electrical and AISI 304 steels

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Guilherme Corrêa; Gonzalez, Berenice Mendonça; Arruda Santos, Leandro de, E-mail: leandro.arruda@demet.ufmg.br

    2017-01-27

    Strain hardening behavior and microstructural evolution of non-grain oriented electrical, dual phase, and AISI 304 steels, subjected to uniaxial tensile tests, were investigated in this study. Tensile tests were performed at room temperature and the strain hardening behavior of the steels was characterized by three different parameters: modified Crussard–Jaoul stages, strain hardening rate and instantaneous strain hardening exponent. Optical microscopic analysis, X-ray diffraction measurements, phase quantification by Rietveld refinement and hardness tests were also carried out in order to correlate the microstructural and mechanical responses to plastic deformation. Distinct strain hardening stages were observed in the steels in terms of the instantaneous strain hardening exponent and the strain hardening rate. The dual phase and non-grain oriented steels exhibited a two-stage strain hardening behavior while the AISI 304 steel displayed multiple stages, resulting in a more complex strain hardening behavior. The dual phase steels showed a high work hardening capacity in stage 1, which was gradually reduced in stage 2. On the other hand, the AISI 304 steel showed high strain hardening capacity, which continued to increase up to the tensile strength. This is a consequence of its additional strain hardening mechanism, based on a strain-induced martensitic transformation, as shown by the X-ray diffraction and optical microscopic analyses.

  1. Study of rapid grain boundary migration in a nanocrystalline Ni thin film

    International Nuclear Information System (INIS)

    Kacher, Josh; Robertson, I.M.; Nowell, Matt; Knapp, J.; Hattar, Khalid

    2011-01-01

    Research highlights: → Abnormal growth is distributed randomly in the foil and initiates at different times. → Growth occurs from seemingly uncorrelated regions of the grain boundary. → Growth twins are created during all stages of abnormal grain growth. → Grain growth patterns are qualitatively similar to a vacancy diffusion model. → Grain boundaries and orientations evolve during growth to minimize system energy. - Abstract: Grain boundary migration associated with abnormal grain growth in pulsed-laser deposited Ni was studied in real time by annealing electron transparent films in situ in the transmission electron microscope. The resulting texture evolution and grain boundary types produced were evaluated by ex situ electron backscatter diffraction of interrupted anneals. The combination of these two techniques allowed for the investigation of grain growth rates, grain morphologies, and the evolution of the orientation and grain boundary distributions. Grain boundaries were found to progress in a sporadic, start/stop fashion with no evidence of a characteristic grain growth rate. The orientations of the abnormally growing grains were found to be predominately //ND throughout the annealing process. A high fraction of twin boundaries developed during the annealing process. The intermittent growth from different locations of the grain boundary is discussed in terms of a vacancy diffusion model for grain growth.

  2. Growth and structural discrimination of cortical neurons on randomly oriented and vertically aligned dense carbon nanotube networks

    Directory of Open Access Journals (Sweden)

    Christoph Nick

    2014-09-01

    Full Text Available The growth of cortical neurons on three dimensional structures of spatially defined (structured randomly oriented, as well as on vertically aligned, carbon nanotubes (CNT is studied. Cortical neurons are attracted towards both types of CNT nano-architectures. For both, neurons form clusters in close vicinity to the CNT structures whereupon the randomly oriented CNTs are more closely colonised than the CNT pillars. Neurons develop communication paths via neurites on both nanoarchitectures. These neuron cells attach preferentially on the CNT sidewalls of the vertically aligned CNT architecture instead than onto the tips of the individual CNT pillars.

  3. Effects of whole grain, fish and bilberries on serum metabolic profile and lipid transfer protein activities: a randomized trial (Sysdimet.

    Directory of Open Access Journals (Sweden)

    Maria Lankinen

    Full Text Available We studied the combined effects of wholegrain, fish and bilberries on serum metabolic profile and lipid transfer protein activities in subjects with the metabolic syndrome.Altogether 131 subjects (40-70 y, BMI 26-39 kg/m(2 with impaired glucose metabolism and features of the metabolic syndrome were randomized into three groups with 12-week periods according to a parallel study design. They consumed either: a wholegrain and low postprandial insulin response grain products, fatty fish 3 times a week, and bilberries 3 portions per day (HealthyDiet, b wholegrain and low postprandial insulin response grain products (WGED, or c refined wheat breads as cereal products (Control. Altogether 106 subjects completed the study. Serum metabolic profile was studied using an NMR-based platform providing information on lipoprotein subclasses and lipids as well as low-molecular-weight metabolites.There were no significant differences in clinical characteristics between the groups at baseline or at the end of the intervention. Mixed model analyses revealed significant changes in lipid metabolites in the HealthyDiet group during the intervention compared to the Control group. All changes reflected increased polyunsaturation in plasma fatty acids, especially in n-3 PUFAs, while n-6 and n-7 fatty acids decreased. According to tertiles of changes in fish intake, a greater increase of fish intake was associated with increased concentration of large HDL particles, larger average diameter of HDL particles, and increased concentrations of large HDL lipid components, even though total levels of HDL cholesterol remained stable.The results suggest that consumption of diet rich in whole grain, bilberries and especially fatty fish causes changes in HDL particles shifting their subclass distribution toward larger particles. These changes may be related to known protective functions of HDL such as reverse cholesterol transport and could partly explain the known protective

  4. Static magnetism and thermal switching in randomly oriented L10 FePt thin films

    Science.gov (United States)

    Lisfi, A.; Pokharel, S.; Alqarni, A.; Akioya, O.; Morgan, W.; Wuttig, M.

    2018-05-01

    Static magnetism and thermally activated magnetic relaxation were investigated in granular FePt films (20 nm-200 nm thick) with random magnetic anisotropy through hysteresis loop, torque curve and magnetization time dependence measurements. While the magnetism of thicker film (200 nm thick) is dominated by a single switching of the ordered L10 phase, thinner film (20 nm) displays a double switching, which is indicative of the presence of the disordered cubic phase. The pronounced behavior of double switching in thinner film suggests that the film grain boundary is composed of soft cubic magnetic phase. The magnetic relaxation study reveals that magnetic viscosity S of the films is strongly dependent on the external applied field and exhibits a maximum value (12 kAm) around the switching field and a vanishing behavior at low (1 kOe) and large (12 kOe) fields. The activation volume of the thermal switching was found to be much smaller than the physical volume of the granular structure due to the incoherent rotation mode of the magnetization reversal mechanism, which is established to be domain wall nucleation.

  5. Large Piezoelectric Strain with Superior Thermal Stability and Excellent Fatigue Resistance of Lead-Free Potassium Sodium Niobate-Based Grain Orientation-Controlled Ceramics.

    Science.gov (United States)

    Quan, Yi; Ren, Wei; Niu, Gang; Wang, Lingyan; Zhao, Jinyan; Zhang, Nan; Liu, Ming; Ye, Zuo-Guang; Liu, Liqiang; Karaki, Tomoaki

    2018-03-19

    Environment-friendly lead-free piezoelectric materials with high piezoelectric response and high stability in a wide temperature range are urgently needed for various applications. In this work, grain orientation-controlled (with a 90% ⟨001⟩ c -oriented texture) (K,Na)NbO 3 -based ceramics with a large piezoelectric response ( d 33 *) = 505 pm V -1 and a high Curie temperature ( T C ) of 247 °C have been developed. Such a high d 33 * value varies by less than 5% from 30 to 180 °C, showing a superior thermal stability. Furthermore, the high piezoelectricity exhibits an excellent fatigue resistance with the d 33 * value decreasing within only by 6% at a field of 20 kV cm -1 up to 10 7 cycles. These exceptional properties can be attributed to the vertical morphotropic phase boundary and the highly ⟨001⟩ c -oriented textured ceramic microstructure. These results open a pathway to promote lead-free piezoelectric ceramics as a viable alternative to lead-based piezoceramics for various practical applications, such as actuators, transducers, sensors, and acoustic devices, in a wide temperature range.

  6. Determination of Specific Losses in the Limbs of an Epstein Frame Using a Three Epstein Frame Methodology Applied to Grain Oriented Electrical Steels.

    Science.gov (United States)

    Parent, Guillaume; Penin, Rémi; Lecointe, Jean-Philippe; Brudny, Jean-François; Belgrand, Thierry

    2016-06-04

    An experimental method to characterize the magnetic properties of Grain Oriented Electrical Steel in the rolling direction is proposed in this paper. It relies on the use of three 25 cm Epstein frames combined to generate three test-frames of different lengths. This enables the identification of the effective specific losses of the electrical steel when magnetization is applied along the rolling direction. As a consequence, it evidences the deviation of the loss figures obtained using the standardised Epstein test. The difference in losses is explained by the fact that the described method gives "only" the losses attached to the straight parts. The concept of the magnetic path length as defined by the standard is discussed.

  7. Determination of Specific Losses in the Limbs of an Epstein Frame Using a Three Epstein Frame Methodology Applied to Grain Oriented Electrical Steels

    Directory of Open Access Journals (Sweden)

    Guillaume Parent

    2016-06-01

    Full Text Available An experimental method to characterize the magnetic properties of Grain Oriented Electrical Steel in the rolling direction is proposed in this paper. It relies on the use of three 25 cm Epstein frames combined to generate three test-frames of different lengths. This enables the identification of the effective specific losses of the electrical steel when magnetization is applied along the rolling direction. As a consequence, it evidences the deviation of the loss figures obtained using the standardised Epstein test. The difference in losses is explained by the fact that the described method gives “only” the losses attached to the straight parts. The concept of the magnetic path length as defined by the standard is discussed.

  8. Investigating the fatigue behavior of grain-oriented Fe-3%Si steel sheets using magnet-optical Kerr microscopy and micromagnetic multiparameter, microstructure and stress analysis

    Directory of Open Access Journals (Sweden)

    Deldar Shayan

    2018-01-01

    Full Text Available Fatigue is considered as a reason for a significant number of mechanical failures of engineering materials. Conventionally, microstructural investigations along with stress-strain hysteresis measurements are performed to understand and characterize the fatigue behavior of metallic materials. Moreover, further physical data like temperature, electrical resistance and, in the case of ferromagnetic materials, magnetic properties can be used for a comprehensive characterization of fatigue process. The present work has employed Magneto-Optical Kerr Effect (MOKE microscope and Micromagnetic Multiparameter, Microstructure and stress Analysis (3MA system to illustrate magnetic domain structure and various intrinsic magnetic properties including magnetic Barkhausen noise (MBN of the investigated material. In order to investigate the influence of the mechanical deformation processes on the magnetic parameters, samples were produced out of the grain-oriented electrical steel sheets and were subjected to a tensile test as well as a cyclic strain increase load test with R = 0 at ambient temperature.

  9. Effect of laser cutting on microstructure and on magnetic properties of grain non-oriented electrical steels

    Energy Technology Data Exchange (ETDEWEB)

    Belhadj, A. E-mail: ahmed@metallur.rug.ac.be; Baudouin, P.; Breaban, F.; Deffontaine, A.; Dewulf, M.; Houbaert, Y

    2003-01-01

    Non-oriented electrical steels have been cut with two different techniques, the laser cutting and the mechanical cutting. In order to investigate the effect of the first technique on magnetic properties, different cutting parameters have been tested. Despite this, the best magnetic properties have been obtained after mechanical cutting. The laser cutting causes a coercive field increase and a permeability drop. Due to thermal effect, internal stress seems to be the main process drawback. No correlation between the heat affected zone and the magnetic properties has been found00.

  10. Influence of crystal shapes on radiative fluxes in visible wavelength: ice crystals randomly oriented in space

    Directory of Open Access Journals (Sweden)

    P. Chervet

    1996-08-01

    Full Text Available Radiative properties of cirrus clouds are one of the major unsolved problems in climate studies and global radiation budget. These clouds are generally composed of various ice-crystal shapes, so we tried to evaluate effects of the ice-crystal shape on radiative fluxes. We calculated radiative fluxes of cirrus clouds with a constant geometrical depth, composed of ice crystals with different shapes (hexagonal columns, bullets, bullet-rosettes, sizes and various concentrations. We considered ice particles randomly oriented in space (3D case and their scattering phase functions were calculated by a ray-tracing method. We calculated radiative fluxes for cirrus layers for different microphysical characteristics by using a discrete-ordinate radiative code. Results showed that the foremost effect of the ice-crystal shape on radiative properties of cirrus clouds was that on the optical thickness, while the variation of the scattering phase function with the ice shape remained less than 3% for our computations. The ice-water content may be a better choice to parameterize the optical properties of cirrus, but the shape effect must be included.

  11. Generalized Pareto for Pattern-Oriented Random Walk Modelling of Organisms' Movements.

    Directory of Open Access Journals (Sweden)

    Sophie Bertrand

    Full Text Available How organisms move and disperse is crucial to understand how population dynamics relates to the spatial heterogeneity of the environment. Random walk (RW models are typical tools to describe movement patterns. Whether Lévy or alternative RW better describes forager movements is keenly debated. We get around this issue using the Generalized Pareto Distribution (GPD. GPD includes as specific cases Normal, exponential and power law distributions, which underlie Brownian, Poisson-like and Lévy walks respectively. Whereas previous studies typically confronted a limited set of candidate models, GPD lets the most likely RW model emerge from the data. We illustrate the wide applicability of the method using GPS-tracked seabird foraging movements and fishing vessel movements tracked by Vessel Monitoring System (VMS, both collected in the Peruvian pelagic ecosystem. The two parameters from the fitted GPD, a scale and a shape parameter, provide a synoptic characterization of the observed movement in terms of characteristic scale and diffusive property. They reveal and quantify the variability, among species and individuals, of the spatial strategies selected by predators foraging on a common prey field. The GPD parameters constitute relevant metrics for (1 providing a synthetic and pattern-oriented description of movement, (2 using top predators as ecosystem indicators and (3 studying the variability of spatial behaviour among species or among individuals with different personalities.

  12. Oriented Markov random field based dendritic spine segmentation for fluorescence microscopy images.

    Science.gov (United States)

    Cheng, Jie; Zhou, Xiaobo; Miller, Eric L; Alvarez, Veronica A; Sabatini, Bernardo L; Wong, Stephen T C

    2010-10-01

    Dendritic spines have been shown to be closely related to various functional properties of the neuron. Usually dendritic spines are manually labeled to analyze their morphological changes, which is very time-consuming and susceptible to operator bias, even with the assistance of computers. To deal with these issues, several methods have been recently proposed to automatically detect and measure the dendritic spines with little human interaction. However, problems such as degraded detection performance for images with larger pixel size (e.g. 0.125 μm/pixel instead of 0.08 μm/pixel) still exist in these methods. Moreover, the shapes of detected spines are also distorted. For example, the "necks" of some spines are missed. Here we present an oriented Markov random field (OMRF) based algorithm which improves spine detection as well as their geometric characterization. We begin with the identification of a region of interest (ROI) containing all the dendrites and spines to be analyzed. For this purpose, we introduce an adaptive procedure for identifying the image background. Next, the OMRF model is discussed within a statistical framework and the segmentation is solved as a maximum a posteriori estimation (MAP) problem, whose optimal solution is found by a knowledge-guided iterative conditional mode (KICM) algorithm. Compared with the existing algorithms, the proposed algorithm not only provides a more accurate representation of the spine shape, but also improves the detection performance by more than 50% with regard to reducing both the misses and false detection.

  13. Generalized Pareto for Pattern-Oriented Random Walk Modelling of Organisms' Movements.

    Science.gov (United States)

    Bertrand, Sophie; Joo, Rocío; Fablet, Ronan

    2015-01-01

    How organisms move and disperse is crucial to understand how population dynamics relates to the spatial heterogeneity of the environment. Random walk (RW) models are typical tools to describe movement patterns. Whether Lévy or alternative RW better describes forager movements is keenly debated. We get around this issue using the Generalized Pareto Distribution (GPD). GPD includes as specific cases Normal, exponential and power law distributions, which underlie Brownian, Poisson-like and Lévy walks respectively. Whereas previous studies typically confronted a limited set of candidate models, GPD lets the most likely RW model emerge from the data. We illustrate the wide applicability of the method using GPS-tracked seabird foraging movements and fishing vessel movements tracked by Vessel Monitoring System (VMS), both collected in the Peruvian pelagic ecosystem. The two parameters from the fitted GPD, a scale and a shape parameter, provide a synoptic characterization of the observed movement in terms of characteristic scale and diffusive property. They reveal and quantify the variability, among species and individuals, of the spatial strategies selected by predators foraging on a common prey field. The GPD parameters constitute relevant metrics for (1) providing a synthetic and pattern-oriented description of movement, (2) using top predators as ecosystem indicators and (3) studying the variability of spatial behaviour among species or among individuals with different personalities.

  14. Exceptionally High Piezoelectric Coefficient and Low Strain Hysteresis in Grain-Oriented (Ba, Ca)(Ti, Zr)O3 through Integrating Crystallographic Texture and Domain Engineering.

    Science.gov (United States)

    Liu, Yingchun; Chang, Yunfei; Li, Fei; Yang, Bin; Sun, Yuan; Wu, Jie; Zhang, Shantao; Wang, Ruixue; Cao, Wenwu

    2017-09-06

    Both low strain hysteresis and high piezoelectric performance are required for practical applications in precisely controlled piezoelectric devices and systems. Unfortunately, enhanced piezoelectric properties were usually obtained with the presence of a large strain hysteresis in BaTiO 3 (BT)-based piezoceramics. In this work, we propose to integrate crystallographic texturing and domain engineering strategies into BT-based ceramics to resolve this challenge. [001] c grain-oriented (Ba 0.94 Ca 0.06 )(Ti 0.95 Zr 0.05 )O 3 (BCTZ) ceramics with a texture degree as high as 98.6% were synthesized by templated grain growth. A very high piezoelectric coefficient (d 33 ) of 755 pC/N, and an extremely large piezoelectric strain coefficient (d 33 * = 2027 pm/V) along with an ultralow strain hysteresis (H s ) of 4.1% were simultaneously achieved in BT-based systems for the first time, which are among the best values ever reported on both lead-free and lead-based piezoceramics. The exceptionally high piezoelectric response is mainly from the reversible contribution, and can be ascribed to the piezoelectric anisotropy, the favorable domain configuration, and the formation of smaller sized domains in the BCTZ textured ceramics. This study paves a new pathway to develop lead-free piezoelectrics with both low strain hysteresis and high piezoelectric coefficient. More importantly, it represents a very exciting discovery with potential application of BT-based ceramics in high-precision piezoelectric actuators.

  15. Bilateral robotic priming before task-oriented approach in subacute stroke rehabilitation: a pilot randomized controlled trial.

    Science.gov (United States)

    Hsieh, Yu-Wei; Wu, Ching-Yi; Wang, Wei-En; Lin, Keh-Chung; Chang, Ku-Chou; Chen, Chih-Chi; Liu, Chien-Ting

    2017-02-01

    To investigate the treatment effects of bilateral robotic priming combined with the task-oriented approach on motor impairment, disability, daily function, and quality of life in patients with subacute stroke. A randomized controlled trial. Occupational therapy clinics in medical centers. Thirty-one subacute stroke patients were recruited. Participants were randomly assigned to receive bilateral priming combined with the task-oriented approach (i.e., primed group) or to the task-oriented approach alone (i.e., unprimed group) for 90 minutes/day, 5 days/week for 4 weeks. The primed group began with the bilateral priming technique by using a bimanual robot-aided device. Motor impairments were assessed by the Fugal-Meyer Assessment, grip strength, and the Box and Block Test. Disability and daily function were measured by the modified Rankin Scale, the Functional Independence Measure, and actigraphy. Quality of life was examined by the Stroke Impact Scale. The primed and unprimed groups improved significantly on most outcomes over time. The primed group demonstrated significantly better improvement on the Stroke Impact Scale strength subscale ( p = 0.012) and a trend for greater improvement on the modified Rankin Scale ( p = 0.065) than the unprimed group. Bilateral priming combined with the task-oriented approach elicited more improvements in self-reported strength and disability degrees than the task-oriented approach by itself. Further large-scale research with at least 31 participants in each intervention group is suggested to confirm the study findings.

  16. High spatial resolution grain orientation and strain mapping in thin films using polychromatic submicron x-ray diffraction

    Science.gov (United States)

    Tamura, N.; MacDowell, A. A.; Celestre, R. S.; Padmore, H. A.; Valek, B.; Bravman, J. C.; Spolenak, R.; Brown, W. L.; Marieb, T.; Fujimoto, H.; Batterman, B. W.; Patel, J. R.

    2002-05-01

    The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area two-dimensional detector technology, has allowed us to develop an x-ray synchrotron technique that is capable of mapping orientation and strain/stress in polycrystalline thin films with submicron spatial resolution. To demonstrate the capabilities of this instrument, we have employed it to study the microstructure of aluminum thin film structures at the granular and subgranular levels. Due to the relatively low absorption of x-rays in materials, this technique can be used to study passivated samples, an important advantage over most electron probes given the very different mechanical behavior of buried and unpassivated materials.

  17. The influence of laser scribing on magnetic domain formation in grain oriented electrical steel visualized by directional neutron dark-field imaging

    Science.gov (United States)

    Rauscher, P.; Betz, B.; Hauptmann, J.; Wetzig, A.; Beyer, E.; Grünzweig, C.

    2016-12-01

    The performance and degree of efficiency of transformers are directly determined by the bulk magnetic properties of grain oriented electrical steel laminations. The core losses can be improved by post manufacturing methods, so-called domain refinement techniques. All these methods induce mechanical or thermal stress that refines the domain structure. The most commonly used technique is laser scribing due to the no-contact nature and the ease of integration in existing production systems. Here we show how directional neutron dark-field imaging allows visualizing the impact of laser scribing on the bulk and supplementary domain structure. In particular, we investigate the domain formation during magnetization of samples depending on laser treatment parameters such as laser energy and line distances. The directional dark-field imaging findings were quantitatively interpreted in the context with global magnetic hysteresis measurements. Especially we exploit the orientation sensitivity in the dark-field images to distinguish between different domain structures alignment and their relation to the laser scribing process.

  18. Influences of crystallographic orientations on deformation mechanism and grain refinement of Al single crystals subjected to one-pass equal-channel angular pressing

    International Nuclear Information System (INIS)

    Han, W.Z.; Zhang, Z.F.; Wu, S.D.; Li, S.X.

    2007-01-01

    The influences of crystallographic orientations on the evolution of dislocation structures and the refinement process of sub-grains in Al single crystals processed by one-pass equal-channel angular pressing (ECAP) were systematically investigated by means of scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy. Three single crystals with different orientations, denoted as crystal I, crystal II and crystal III, were specially designed according to the shape of the ECAP die. For crystal I, its insert direction is parallel to [1 1 0] and its extrusion direction is parallel to [1-bar11]. For crystal II, the (1-bar11) plane is located parallel to the intersection plane of the ECAP die, and the [1 1 0] direction is along the general shear direction on the intersection plane. For crystal III, the (1-bar11) plane is laid on the plane perpendicular to the intersection of the ECAP die, and the [1 1 0] direction is vertical to the general shear direction. For crystal I, abundant cell block structures with multi-slip characters were formed, and they should be induced by four symmetric slip systems, while for crystal II, there are two sets of sub-grain structures with higher misorientation, making an angle of ∼70 deg., which can be attributed to the interactions of the two asymmetric primary slip planes, whereas for crystal III, only one set of ribbon structures was parallel to the traces of (1-bar11) with the lowest misorientation angle among the three single crystals, which should result from the homogeneous slip on the primary slip plane. The different microstructural features of the three single crystals provide clear experimental evidence that the microstructures and misorientation evolution are strongly affected by the crystallographic orientation or by the interaction between shear deformation imposed by the ECAP die and the intrinsic slip deformation of the single crystals. Based on the experimental results and the

  19. Hindrance Velocity Model for Phase Segregation in Suspensions of Poly-dispersed Randomly Oriented Spheroids

    Science.gov (United States)

    Faroughi, S. A.; Huber, C.

    2015-12-01

    Crystal settling and bubbles migration in magmas have significant effects on the physical and chemical evolution of magmas. The rate of phase segregation is controlled by the force balance that governs the migration of particles suspended in the melt. The relative velocity of a single particle or bubble in a quiescent infinite fluid (melt) is well characterized; however, the interplay between particles or bubbles in suspensions and emulsions and its effect on their settling/rising velocity remains poorly quantified. We propose a theoretical model for the hindered velocity of non-Brownian emulsions of nondeformable droplets, and suspensions of spherical solid particles in the creeping flow regime. The model is based on three sets of hydrodynamic corrections: two on the drag coefficient experienced by each particle to account for both return flow and Smoluchowski effects and a correction on the mixture rheology to account for nonlocal interactions between particles. The model is then extended for mono-disperse non-spherical solid particles that are randomly oriented. The non-spherical particles are idealized as spheroids and characterized by their aspect ratio. The poly-disperse nature of natural suspensions is then taken into consideration by introducing an effective volume fraction of particles for each class of mono-disperse particles sizes. Our model is tested against new and published experimental data over a wide range of particle volume fraction and viscosity ratios between the constituents of dispersions. We find an excellent agreement between our model and experiments. We also show two significant applications for our model: (1) We demonstrate that hindered settling can increase mineral residence time by up to an order of magnitude in convecting magma chambers. (2) We provide a model to correct for particle interactions in the conventional hydrometer test to estimate the particle size distribution in soils. Our model offers a greatly improved agreement with

  20. A Randomized Trial to Measure the Efficacy of Applying Task Oriented Role Assignment to Improve Neonatal Resuscitation

    Science.gov (United States)

    2017-05-06

    In an effort to address performance gaps we devised a teaching paradigm, called Task-Oriented Role Ass ignment’, in which we have delegated a...task delegation , thereby improving NRP performance. Health care professionals taking the NRP course were randomized to either the control group, which...such as leadership (mean = 4· control, s study; p = 0.05). However, both groups scored similarly in overall NRP task performance with mean scores of

  1. Whole grain and body weight changes in apparently healthy adults: a systematic review and meta-analysis of randomized controlled studies123

    DEFF Research Database (Denmark)

    Pol, Korrie; Christensen, Robin; Bartels, Else M

    2013-01-01

    Background: Whole grains have received increased attention for their potential role in weight regulation. A high intake has been associated with smaller weight gain in prospective cohort studies, whereas the evidence from randomized controlled studies has been less consistent. Objective: We...... assessed the effects of whole-grain compared with non–whole-grain foods on changes in body weight, percentage of body fat, and waist circumference by using a meta-analytic approach. Design: We conducted a systematic literature search in selected databases. Studies were included in the review if they were...... weight compared with control consumption, but a small beneficial effect on body fat may be present. The relatively short duration of intervention studies (≤16 wk) may explain the lack of difference in body weight and fat. Discrepancies between studies may be caused by differences in study design....

  2. Monte Carlo simulation of grain growth

    Directory of Open Access Journals (Sweden)

    Paulo Blikstein

    1999-07-01

    Full Text Available Understanding and predicting grain growth in Metallurgy is meaningful. Monte Carlo methods have been used in computer simulations in many different fields of knowledge. Grain growth simulation using this method is especially attractive as the statistical behavior of the atoms is properly reproduced; microstructural evolution depends only on the real topology of the grains and not on any kind of geometric simplification. Computer simulation has the advantage of allowing the user to visualize graphically the procedures, even dynamically and in three dimensions. Single-phase alloy grain growth simulation was carried out by calculating the free energy of each atom in the lattice (with its present crystallographic orientation and comparing this value to another one calculated with a different random orientation. When the resulting free energy is lower or equal to the initial value, the new orientation replaces the former. The measure of time is the Monte Carlo Step (MCS, which involves a series of trials throughout the lattice. A very close relationship between experimental and theoretical values for the grain growth exponent (n was observed.

  3. Task-Oriented Training with Computer Games for People with Rheumatoid Arthritis or Hand Osteoarthritis: A Feasibility Randomized Controlled Trial.

    Science.gov (United States)

    Srikesavan, Cynthia Swarnalatha; Shay, Barbara; Szturm, Tony

    2016-09-13

    To examine the feasibility of a clinical trial on a novel, home-based task-oriented training with conventional hand exercises in people with rheumatoid arthritis or hand osteoarthritis. To explore the experiences of participants who completed their respective home exercise programmes. Thirty volunteer participants aged between 30 and 60 years and diagnosed with rheumatoid arthritis or hand osteoarthritis were proposed for a single-center, assessor-blinded, randomized controlled trial ( ClinicalTrials.gov : NCT01635582). Participants received task-oriented training with interactive computer games and objects of daily life or finger mobility and strengthening exercises. Both programmes were home based and were done four sessions per week with 20 minutes each session for 6 weeks. Major feasibility outcomes were number of volunteers screened, randomized, and retained; completion of blinded assessments, exercise training, and home exercise sessions; equipment and data management; and clinical outcomes of hand function. Reaching the recruitment target in 18 months and achieving exercise compliance >80% were set as success criteria. Concurrent with the trial, focus group interviews explored experiences of those participants who completed their respective programmes. After trial initiation, revisions in inclusion criteria were required to promote recruitment. A total of 17 participants were randomized and 15 were retained. Completion of assessments, exercise training, and home exercise sessions; equipment and data collection and management demonstrated excellent feasibility. Both groups improved in hand function outcomes and exercise compliance was above 85%. Participants perceived both programmes as appropriate and acceptable. Participants who completed task-oriented training also agreed that playing different computer games was enjoyable, engaging, and motivating. Findings demonstrate initial evidence on recruitment, feasibility of trial procedures, and acceptability of

  4. Processing, adhesion and electrical properties of silicon steel having non-oriented grains coated with silica and alumina sol-gel

    International Nuclear Information System (INIS)

    Vasconcelos, D.C.L.; Orefice, R.L.; Vasconcelos, W.L.

    2007-01-01

    Silicon steels having non-oriented grains are usually coated with a series of inorganic or organic films to be used in electrical applications. However, the commercially available coatings have several disadvantages that include poor adhesion to the substrates, low values of electrical resistance and degradation at higher temperatures. In this work, silica and alumina sol-gel films were deposited onto silicon steel in order to evaluate the possibility of replacing the commercially available coatings by these sol-gel derived materials. Silica and alumina sol-gel coatings were prepared by dipping silicon steel samples into hydrolyzed silicon or aluminum alkoxides. Samples coated with sol-gel films were studied by scanning electron microscopy, energy dispersive spectroscopy and infrared spectroscopy. Adhesion between silicon steel and sol-gel films was measured by using several standard adhesion tests. Electrical properties were evaluated by the Franklin method. Results showed that homogeneous sol-gel films can be deposited onto silicon steel. Thicknesses of the films could be easily managed by altering the speed of deposition. The structure of the films could also be tailored by introducing additives, such as nitric acid and N,N-dimethyl formamide. Adhesion tests revealed a high level of adhesion between coatings and metal. The Franklin test showed that sol-gel films can produce coated samples with electrical resistances suitable for electrical applications. Electrical properties of the coated samples could also be manipulated by altering the structure of the sol-gel films or by changing the thickness of them

  5. Use of the Fourier transform infrared (FTIR) technique for determination of the composition of final phosphate coatings on grain-oriented electrical steel

    International Nuclear Information System (INIS)

    Poultney, Darren; Snell, David

    2008-01-01

    Electrical steels are highly specialised, magnetically soft materials, used to form the cores that carry the magnetic flux in electrical machines such as motors, generators and transformers. The steel strip is coated with a phosphate-based solution, which, on curing, provides an electrically insulating layer that also imparts a tension onto the strip. It has previously been shown that the magnetic losses of the material are affected by the ratio of phosphate and silica within the coating solution [O. Tanaka, H. Kobayashi, E. Minematsu, New insulating coating for grain-oriented electrical steel, J. Mater. Eng. 13 (1991) 161-168.]. It would therefore be highly beneficial to possess an analytical technique that can be used to accurately and rapidly determine the composition of this coating. This paper details the evaluation of the Fourier transform infrared (FTIR) technique for this purpose. Analysing each of the important constituents separately enabled their specific absorption bands to be identified, and laboratory trials produced spectra that exhibited a good agreement with theoretical predictions. Analysis of samples coated under production conditions was found to be more challenging due to the detection of an underlying forsterite layer. However, there is potential for FTIR analysis when using regions of the spectra that were unaffected by this compound

  6. 3D random Voronoi grain-based models for simulation of brittle rock damage and fabric-guided micro-fracturing

    Directory of Open Access Journals (Sweden)

    E. Ghazvinian

    2014-12-01

    Full Text Available A grain-based distinct element model featuring three-dimensional (3D Voronoi tessellations (random poly-crystals is proposed for simulation of crack damage development in brittle rocks. The grain boundaries in poly-crystal structure produced by Voronoi tessellations can represent flaws in intact rock and allow for numerical replication of crack damage progression through initiation and propagation of micro-fractures along grain boundaries. The Voronoi modelling scheme has been used widely in the past for brittle fracture simulation of rock materials. However the difficulty of generating 3D Voronoi models has limited its application to two-dimensional (2D codes. The proposed approach is implemented in Neper, an open-source engine for generation of 3D Voronoi grains, to generate block geometry files that can be read directly into 3DEC. A series of Unconfined Compressive Strength (UCS tests are simulated in 3DEC to verify the proposed methodology for 3D simulation of brittle fractures and to investigate the relationship between each micro-parameter and the model's macro-response. The possibility of numerical replication of the classical U-shape strength curve for anisotropic rocks is also investigated in numerical UCS tests by using complex-shaped (elongated grains that are cemented to one another along their adjoining sides. A micro-parameter calibration procedure is established for 3D Voronoi models for accurate replication of the mechanical behaviour of isotropic and anisotropic (containing a fabric rocks.

  7. Do Savings Mediate Changes in Adolescents' Future Orientation and Health-Related Outcomes? Findings From Randomized Experiment in Uganda.

    Science.gov (United States)

    Karimli, Leyla; Ssewamala, Fred M

    2015-10-01

    This present study tests the proposition that an economic strengthening intervention for families caring for AIDS-orphaned adolescents would positively affect adolescent future orientation and psychosocial outcomes through increased asset accumulation (in this case, by increasing family savings). Using longitudinal data from the cluster-randomized experiment, we ran generalized estimating equation models with robust standard errors clustering on individual observations. To examine whether family savings mediate the effect of the intervention on adolescents' future orientation and psychosocial outcomes, analyses were conducted in three steps: (1) testing the effect of intervention on mediator; (2) testing the effect of mediator on outcomes, controlling for the intervention; and (3) testing the significance of mediating effect using Sobel-Goodman method. Asymmetric confidence intervals for mediated effect were obtained through bootstrapping-to address the assumption of normal distribution. Results indicate that participation in a matched Child Savings Account (CSA) program improved adolescents' future orientation and psychosocial outcomes by reducing hopelessness, enhancing self-concept, and improving adolescents' confidence about their educational plans. However, the positive intervention effect on adolescent future orientation and psychosocial outcomes was not transmitted through saving. In other words, participation in the matched CSA program improved adolescent future orientation and psychosocial outcomes regardless of its impact on reported savings. Further research is necessary to understand exactly how participation in economic strengthening interventions, for example, those that employ matched CSAs, shape adolescent future orientation and psychosocial outcomes: what, if not savings, transmits the treatment effect and how? Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  8. Grain-resolved elastic strains in deformed copper measured by three-dimensional X-ray diffraction

    DEFF Research Database (Denmark)

    Oddershede, Jette; Schmidt, Søren; Poulsen, Henning Friis

    2011-01-01

    This X-ray diffraction study reports the grain-resolved elastic strains in about 1000 randomly oriented grains embedded in a polycrystalline copper sample. Diffraction data were collected in situ in the undeformed state and at a plastic strain of 1.5% while the sample was under tensile load...

  9. Grain boundary migration

    International Nuclear Information System (INIS)

    Dimitrov, O.

    1975-01-01

    Well-established aspects of grain-boundary migration are first briefly reviewed (influences of driving force, temperature, orientation and foreign atoms). Recent developments of the experimental methods and results are then examined, by considering the various driving of resistive forces acting on grain boundaries. Finally, the evolution in the theoretical models of grain-boundary motion is described, on the one hand for ideally pure metals and, on the other hand, in the presence of solute impurity atoms [fr

  10. A Novel Screen for Suppressors of Breast Tumor Cell Growth Using an Oriented Random Peptide Library Method to Identify Inhibitors of the ErbB2 Tyrosine Kinase

    National Research Council Canada - National Science Library

    Carraway, Kermit

    1998-01-01

    .... To identify potential antagonists, the extracellular ligand binding domain of the ErbB2 is immobilized on a column support, and used to affinity purify cyclic peptides from oriented random peptide libraries...

  11. A Novel Screen for Suppressors of Breast Tumor Cell Growth Using an Oriented Random Peptide Library Method to Identify Inhibitors of the ErbB2 Tyrosine Kinase

    National Research Council Canada - National Science Library

    Carraway, Kermit

    1999-01-01

    .... To identify potential antagonists, the extracellular ligand binding domain of the ErbB2 is immobilized on a column support, and used to affinity purify cyclic peptides from oriented random peptide libraries...

  12. Mechanical properties of banana/kenaf fiber-reinforced hybrid polyester composites: Effect of woven fabric and random orientation

    International Nuclear Information System (INIS)

    Alavudeen, A.; Rajini, N.; Karthikeyan, S.; Thiruchitrambalam, M.; Venkateshwaren, N.

    2015-01-01

    Highlights: • This paper is presents the fabrications of kenaf/banana fiber hybrid composites. • Effect of weaving pattern and random orientation on mechanical properties was studied. • Role of interfacial adhesion due to chemical modifications were analyzed with the aid of SEM. • Hybridization of kenaf and banana fibers in plain woven composites exhibits maximum mechanical strength. - Abstract: The present work deals with the effect of weaving patterns and random orientatation on the mechanical properties of banana, kenaf and banana/kenaf fiber-reinforced hybrid polyester composites. Composites were prepared using the hand lay-up method with two different weaving patterns, namely, plain and twill type. Of the two weaving patterns, the plain type showed improved tensile properties compared to the twill type in all the fabricated composites. Furthermore, the maximum increase in mechanical strength was observed in the plain woven hybrid composites rather than in randomly oriented composites. This indicates minimum stress development at the interface of composites due to the distribution of load transfer along the fiber direction. Moreover, alkali (NaOH) and sodium lauryl sulfate (SLS) treatments appear to provide an additional improvement in mechanical strength through enhanced interfacial bonding. Morphological studies of fractured mechanical testing samples were performed by scanning electron microscopy (SEM) to understand the de-bonding of fiber/matrix adhesion

  13. The Influence of Coping-oriented Hypnotic Suggestions on Chronic Pain in Patients with Spinal Cord Injury (SCI): A Randomized Controlled Study

    DEFF Research Database (Denmark)

    Knudsen, Lone; Kjøgx, Heidi; Kasch, Helge

    -hypnosis is unknown. The aim is to investigate the effect of coping-oriented hypnotic suggestions on chronic pain post-hypnosis. Methods: Seventy-five SCI-patients with chronic pain (>3, NRS 0-10) are randomized into one of three conditions; 1) coping-oriented hypnosis plus current treatment, 2) neutral hypnosis plus...

  14. Effects of Coping-Oriented Couples Therapy on Depression: A Randomized Clinical Trial

    Science.gov (United States)

    Bodenmann, Guy; Plancherel, Bernard; Beach, Steven R. H.; Widmer, Kathrin; Gabriel, Barbara; Meuwly, Nathalie; Charvoz, Linda; Hautzinger, Martin; Schramm, Elisabeth

    2008-01-01

    The aim of this study was to evaluate the effectiveness of treating depression with coping-oriented couples therapy (COCT) as compared with cognitive-behavioral therapy (CBT; A. T. Beck, C. Ward, & M. Mendelson, 1961) and interpersonal psychotherapy (IPT; M. M. Weissman, J. C. Markowitz, & G. L. Klerman, 2000). Sixty couples, including 1…

  15. Circulating bile acids in healthy adults respond differently to a dietary pattern characterized by whole grains, legumes and fruits and vegetables compared to a diet high in refined grains and added sugars: a randomized, controlled, crossover feeding study.

    Science.gov (United States)

    Ginos, Bigina N R; Navarro, Sandi L; Schwarz, Yvonne; Gu, Haiwei; Wang, Dongfang; Randolph, Timothy W; Shojaie, Ali; Hullar, Meredith A J; Lampe, Paul D; Kratz, Mario; Neuhouser, Marian L; Raftery, Daniel; Lampe, Johanna W

    2018-02-16

    The effects of diets high in refined grains on biliary and colonic bile acids have been investigated extensively. However, the effects of diets high in whole versus refined grains on circulating bile acids, which can influence glucose homeostasis and inflammation through activation of farnesoid X receptor (FXR) and G protein-coupled bile acid receptor 1 (TGR5), have not been studied. We conducted a secondary analysis from a randomized controlled crossover feeding trial (NCT00622661) in 80 healthy adults (40 women/40 men, age 18-45 years) from the greater Seattle Area, half of which were normal weight (BMI 18.5-25.0 kg/m 2 ) and half overweight to obese (BMI 28.0-39.9 kg/m 2 ). Participants consumed two four-week controlled diets in randomized order: 1) a whole grain diet (WG diet), designed to be low in glycemic load (GL), high in whole grains, legumes, and fruits and vegetables, and 2) a refined grain diet (RG diet), designed to be high GL, high in refined grains and added sugars, separated by a four-week washout period. Quantitative targeted analysis of 55 bile acid species in fasting plasma was performed using liquid chromatography tandem mass spectrometry. Concentrations of glucose, insulin, and CRP were measured in fasting serum. Linear mixed models were used to test the effects of diet on bile acid concentrations, and determine the association between plasma bile acid concentrations and HOMA-IR and CRP. Benjamini-Hochberg false discovery rate (FDR) < 0.05 was used to control for multiple testing. A total of 29 plasma bile acids were reliably detected and retained for analysis. Taurolithocholic acid (TLCA), taurocholic acid (TCA) and glycocholic acid (GCA) were statistically significantly higher after the WG compared to the RG diet (FDR < 0.05). There were no significant differences by BMI or sex. When evaluating the association of bile acids and HOMA-IR, GCA, taurochenodeoxycholic acid, ursodeoxycholic acid (UDCA), 5β-cholanic acid-3β,12

  16. Influence of grain size in the near-micrometre regime on the deformation microstructure in aluminium

    International Nuclear Information System (INIS)

    Le, G.M.; Godfrey, A.; Hansen, N.; Liu, W.; Winther, G.; Huang, X.

    2013-01-01

    The effect of grain size on deformation microstructure formation in the near-micrometre grain size regime has been studied using samples of aluminium prepared using a spark plasma sintering technique. Samples in a fully recrystallized grain condition with average grain sizes ranging from 5.2 to 0.8 μm have been prepared using this technique. Examination in the transmission electron microscope of these samples after compression at room temperature to approximately 20% reduction reveals that grains larger than 7 μm are subdivided by cell block boundaries similar to those observed in coarse-grained samples, with a similar dependency on the crystallographic orientation of the grains. With decreasing grain size down to approx. 1 μm there is a gradual transition from cell block structures to cell structures. At even smaller grain sizes of down to approx. 0.5 μm the dominant features are dislocation bundles and random dislocations, although at a larger compressive strain of 30% dislocation rotation boundaries may also be found in the interior of grains of this size. A standard 〈1 1 0〉 fibre texture is found for all grain sizes, with a decreasing sharpness with decreasing grain size. The structural transitions with decreasing grain size are discussed based on the general principles of grain subdivision by deformation-induced dislocation boundaries and of low-energy dislocation structures as applied to the not hitherto explored near-micrometre grain size regime

  17. Random Pattern Vertically Oriented, Partial Thickness Buccinator Myomucosal Flap for Intraoral Reconstruction: A Report of Two Cases

    Directory of Open Access Journals (Sweden)

    Amin Rahpeyma

    2016-05-01

    Full Text Available Introduction: Reconstruction of the oral cavity witha flap design containing the buccal mucosa and buccinator muscle but excluding the facial artery and vein is the topic of these case reports. Case Reports: This article uses random pattern vertically oriented partial thickness buccinator myomucosal flap for intraoral reconstruction in two cases. The first was for lining the mandibular anterior vestibule in a trauma patient. The second was for oral side coverage of bone graft in special cleft patient. In both patients, this flap survived and good bone coverage with non-keratinized mucosa was obtained. Conclusion:  Thin long buccal myomucosal flap not including facial artery and vein can survive.

  18. Shape dependency of the extinction and absorption cross sections of dust aerosols modeled as randomly oriented spheroids

    Directory of Open Access Journals (Sweden)

    R. Wagner

    2011-09-01

    Full Text Available We present computational results on the shape dependency of the extinction and absorption cross sections of dustlike aerosol particles that were modeled as randomly oriented spheroids. Shape dependent variations in the extinction cross sections are largest in the size regime that is governed by the interference structure. Elongated spheroids best fitted measured extinction spectra of re-dispersed Saharan dust samples. For dust particles smaller than 1.5 μm in diameter and low absorption potential, shape effects on the absorption cross sections are very small.

  19. Analysis and modeling of resistive switching mechanisms oriented to resistive random-access memory

    International Nuclear Information System (INIS)

    Huang Da; Wu Jun-Jie; Tang Yu-Hua

    2013-01-01

    With the progress of the semiconductor industry, the resistive random-access memory (RAM) has drawn increasing attention. The discovery of the memristor has brought much attention to this study. Research has focused on the resistive switching characteristics of different materials and the analysis of resistive switching mechanisms. We discuss the resistive switching mechanisms of different materials in this paper and analyze the differences of those mechanisms from the view point of circuitry to establish their respective circuit models. Finally, simulations are presented. We give the prospect of using different materials in resistive RAM on account of their resistive switching mechanisms, which are applied to explain their resistive switchings

  20. Mindfulness-Oriented Recovery Enhancement for Internet Gaming Disorder in U.S. Adults: A Stage 1 Randomized Controlled Trial

    Science.gov (United States)

    Li, Wen; Garland, Eric L.; McGovern, Patricia; O'Brien, Jennifer E.; Tronnier, Christine; Howard, Matthew O.

    2017-01-01

    Empirical studies have identified increasing rates of Internet Gaming Disorder (IGD) and associated adverse consequences. However, very few evidence-based interventions have been evaluated for IGD or problematic video gaming behaviors. This study evaluated Mindfulness-Oriented Recovery Enhancement (MORE) as a treatment for IGD. Thirty adults (M age = 25.0, SD = 5.4) with IGD or problematic video gaming behaviors were randomized to 8 weeks of group-based MORE or 8 weeks of a support group (SG) control condition. Outcome measures were administered at pre-and posttreatment, and 3-month following treatment completion using self-report instruments. Linear mixed models were used for outcome analyses. MORE participants had significantly greater reductions in the number of DSM-5 IGD criteria they met, craving for video gaming, and maladaptive cognitions associated with gaming than SG participants, and therapeutic benefits were maintained at 3-month follow-up. MORE is a promising treatment approach for IGD. PMID:28437120

  1. Highly efficient hybrid energy generator: coupled organic photovoltaic device and randomly oriented electrospun poly(vinylidene fluoride) nanofiber.

    Science.gov (United States)

    Park, Boongik; Lee, Kihwan; Park, Jongjin; Kim, Jongmin; Kim, Ohyun

    2013-03-01

    A hybrid architecture consisting of an inverted organic photovoltaic device and a randomly-oriented electrospun PVDF piezoelectric device was fabricated as a highly-efficient energy generator. It uses the inverted photovoltaic device with coupled electrospun PVDF nanofibers as tandem structure to convert solar and mechanical vibrations energy to electricity simultaneously or individually. The power conversion efficiency of the photovoltaic device was also significantly improved up to 4.72% by optimized processes such as intrinsic ZnO, MoO3 and active layer. A simple electrospinning method with the two electrode technique was adopted to achieve a high voltage of - 300 mV in PVDF piezoelectric fibers. Highly-efficient HEG using voltage adder circuit provides the conceptual possibility of realizing multi-functional energy generator whenever and wherever various energy sources are available.

  2. Random oriented hexagonal nickel hydroxide nanoplates grown on graphene as binder free anode for lithium ion battery with high capacity

    Science.gov (United States)

    Du, Yingjie; Ma, Hu; Guo, Mingxuan; Gao, Tie; Li, Haibo

    2018-05-01

    In this work, two-step method has been employed to prepare random oriented hexagonal hydroxide nanoplates on graphene (Ni(OH)2@G) as binder free anode for lithium ion battery (LIB) with high capacity. The morphology, microstructure, crystal phase and elemental bonding have been characterized. When evaluated as anode for LIB, the Ni(OH)2@G exhibited high initial discharge capacity of 1318 mAh/g at the current density of 50 mA/g. After 80 cycles, the capacity was maintained at 834 mAh/g, implying 63.3% remaining. Even the charge rate was increased to 2000 mA/g, an impressive capacity of 141 mAh/g can be obtained, indicating good rate capability. The superior LIB behavior of Ni(OH)2@G is ascribed to the excellent combination between Ni(OH)2 nanoplates and graphene via both covalent chemical bonding and van der Waals interactions.

  3. Comparison of antiemetic efficacy of granisetron and ondansetron in Oriental patients: a randomized crossover study.

    Science.gov (United States)

    Poon, R. T.; Chow, L. W.

    1998-01-01

    A double-blind randomized crossover trial was performed to compare the antiemetic efficacy of two 5-HT3 receptor antagonists, granisetron and ondansetron, in Chinese patients receiving adjuvant chemotherapy (cyclophosphamide, methotrexate and 5-fluorouracil) for breast cancer. Twenty patients were randomized to receive chemotherapy with either granisetron on day 1 and ondansetron on day 8 of the first cycle followed by the reverse order in the second cycle, or vice versa. The number of vomiting episodes and the severity of nausea in the first 24 h (acute vomiting/nausea) and the following 7 days (delayed vomiting/nausea) were studied. Acute vomiting was completely prevented in 29 (72.5%) cycles with granisetron and 27 (67.5%) cycles with ondansetron, and treatment failure (>5 vomiting episodes) occurred in two (5%) cycles with each agent (P = NS). Acute nausea was completely controlled in 15 (37.5%) cycles with granisetron and 14 (35%) cycles with ondansetron, whereas severe acute nausea occurred in four (10%) cycles with each agent (P = NS). However, complete response for delayed vomiting was observed in only 21 (52.5%) cycles with granisetron and 22 (55%) cycles with ondansetron (P = NS), and delayed nausea was completely controlled in only 11 (27.5%) and ten (25%) cycles respectively (P = NS). In conclusion, both granisetron and ondansetron are effective in controlling acute nausea and vomiting in Chinese patients, with equivalent antiemetic efficacy. Control of delayed nausea and vomiting is less satisfactory. PMID:9635849

  4. Mechanical properties of unidirectional and randomly oriented kenaf bast fibre composites using polypropylene resin matrix

    International Nuclear Information System (INIS)

    Sharifah Hanisah Syed Abd Aziz; Khairul Zaman Mohd Dahlan

    2004-01-01

    Fibres are known to confer strength and rigidity to the weak and brittle matrix and currently, research in composite materials is being directed at using natural fibers instead of synthetic fibres. In this work long and random kenaf fibers were used in the as-received condition and alkalized with a 0.06M NaOH solution. They were combined with polypropylene thin sheets and hot-pressed to form natural fibre composites. The mechanical properties of the composites were investigated to observe the effect of fibre alignment, fibre treatment, and the method of moulding technique used. A general trend was observed whereby alkalized and long fibre composites give higher flexural modulus and flexural strength compared with random mat and untreated fibres. The long fibre composites also gave a higher work of fracture. However, the correlation between fibre surface treatment and the work of fracture was less clear. The method of moulding used also need to be improved to optimize the performance of the composites manufactured as the overall mechanical test result showed some irregularities. Pre-irradiation on the polypropylene pellets before the composite is manufactured will be considered as one of the mechanism in enhancing the mechanical performance of the composites in future work. (Author)

  5. Resource-oriented coaching for reduction of examination-related stress in medical students: an exploratory randomized controlled trial.

    Science.gov (United States)

    Kötter, Thomas; Niebuhr, Frank

    2016-01-01

    The years spent in acquiring medical education is considered a stressful period in the life of many students. Students whose mental health deteriorates during this long period of study are less likely to become empathic and productive physicians. In addition to other specific stressors, academic examinations seem to further induce medical school-related stress and anxiety. Combined group and individual resource-oriented coaching early in medical education might reduce examination-related stress and anxiety and, consequently, enhance academic performance. Good quality evidence, however, remains scarce. In this study, therefore, we explored the question of whether coaching affects examination-related stress and health in medical students. We conducted a randomized controlled trial. Students who registered for the first medical academic examination in August 2014 at the University of Lübeck were recruited and randomized into three groups. The intervention groups 1 and 2 received a 1-hour psychoeducative seminar. Group 1 additionally received two 1-hour sessions of individual coaching during examination preparation. Group 3 served as a control group. We compared changes in self-rated general health (measured by a single item), anxiety and depression (measured by the hospital anxiety and depression scale), as well as medical school stress (measured by the perceived medical school stress instrument). In order to further investigate the influence of group allocation on perceived medical school stress, we conducted a linear regression analysis. We saw a significant deterioration of general health and an increase in anxiety and depression scores in medical students while preparing for an examination. We found a small, but statistically significant, effect of group allocation on the development of perceived medical school stress. However, we could not differentiate between the effects of group coaching only and group coaching in combination with two sessions of individual

  6. Structural and magnetic properties of Co films on highly textured and randomly oriented C_6_0 layers

    International Nuclear Information System (INIS)

    Kim, Dong-Ok; Choi, Jun Woo; Lee, Dong Ryeol

    2016-01-01

    The structural and magnetic properties of Co/C_6_0/pentacene and Co/C_6_0 thin film structures were investigated. Atomic force microscopy and x-ray reflectivity analysis show that the presence or absence of a pentacene buffer layer leads to a highly textured or randomly oriented C_6_0 layer, respectively. A Co film deposited on a randomly oriented C_6_0 layer penetrates into the C_6_0 layer when it is deposited at a slow deposition rate. The Co penetration can be minimized, regardless of the Co deposition rate, by growth on a highly textured and nanostructured C_6_0/pentacene layer. Vibrating sample magnetometry measurements show that the saturation magnetization of Co/C_6_0/pentacene is significantly reduced compared to that of Co/C_6_0. On the other hand, the Co penetration does not seem to have an effect on the magnetic properties, suggesting that the structural properties of the Co and C_6_0 layer, rather than the Co penetration into the organic C_6_0 layer, are critical to the magnetic properties of the Co/C_6_0. - Highlights: • Structural and magnetic properties of metal(Co)-organic(C_6_0) interface is studied. • Highly textured C_6_0 layer was grown on a pentacene buffer layer (C_6_0/pentacene). • Co penetration into the C_6_0 is significantly suppressed in Co/C_6_0/pentacene. • The Co magnetization in Co/C_6_0/pentacene is reduced than that in Co/C_6_0.

  7. Structural and magnetic properties of Co films on highly textured and randomly oriented C{sub 60} layers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Ok [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Choi, Jun Woo, E-mail: junwoo@kist.re.kr [Center for Spintronics Research, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Lee, Dong Ryeol, E-mail: drlee@ssu.ac.kr [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of)

    2016-03-01

    The structural and magnetic properties of Co/C{sub 60}/pentacene and Co/C{sub 60} thin film structures were investigated. Atomic force microscopy and x-ray reflectivity analysis show that the presence or absence of a pentacene buffer layer leads to a highly textured or randomly oriented C{sub 60} layer, respectively. A Co film deposited on a randomly oriented C{sub 60} layer penetrates into the C{sub 60} layer when it is deposited at a slow deposition rate. The Co penetration can be minimized, regardless of the Co deposition rate, by growth on a highly textured and nanostructured C{sub 60}/pentacene layer. Vibrating sample magnetometry measurements show that the saturation magnetization of Co/C{sub 60}/pentacene is significantly reduced compared to that of Co/C{sub 60}. On the other hand, the Co penetration does not seem to have an effect on the magnetic properties, suggesting that the structural properties of the Co and C{sub 60} layer, rather than the Co penetration into the organic C{sub 60} layer, are critical to the magnetic properties of the Co/C{sub 60}. - Highlights: • Structural and magnetic properties of metal(Co)-organic(C{sub 60}) interface is studied. • Highly textured C{sub 60} layer was grown on a pentacene buffer layer (C{sub 60}/pentacene). • Co penetration into the C{sub 60} is significantly suppressed in Co/C{sub 60}/pentacene. • The Co magnetization in Co/C{sub 60}/pentacene is reduced than that in Co/C{sub 60}.

  8. SILICON CARBIDE GRAIN BOUNDARY DISTRIBUTIONS, IRRADIATION CONDITIONS, AND SILVER RETENTION IN IRRADIATED AGR-1 TRISO FUEL PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Lillo, T. M.; Rooyen, I. J.; Aguiar, J. A.

    2016-11-01

    Precession electron diffraction in the transmission electron microscope was used to map grain orientation and ultimately determine grain boundary misorientation angle distributions, relative fractions of grain boundary types (random high angle, low angle or coincident site lattice (CSL)-related boundaries) and the distributions of CSL-related grain boundaries in the SiC layer of irradiated TRISO-coated fuel particles. Two particles from the AGR-1 experiment exhibiting high Ag-110m retention (>80%) were compared to a particle exhibiting low Ag-110m retention (<19%). Irradiated particles with high Ag-110m retention exhibited a lower fraction of random, high angle grain boundaries compared to the low Ag-110m retention particle. An inverse relationship between the random, high angle grain boundary fraction and Ag-110m retention is found and is consistent with grain boundary percolation theory. Also, comparison of the grain boundary distributions with previously reported unirradiated grain boundary distributions, based on SEM-based EBSD for similarly fabricated particles, showed only small differences, i.e. a greater low angle grain boundary fraction in unirradiated SiC. It was, thus, concluded that SiC layers with grain boundary distributions susceptible to Ag-110m release were present prior to irradiation. Finally, irradiation parameters were found to have little effect on the association of fission product precipitates with specific grain boundary types.

  9. Infrared Extinction Performance of Randomly Oriented Microbial-Clustered Agglomerate Materials.

    Science.gov (United States)

    Li, Le; Hu, Yihua; Gu, Youlin; Zhao, Xinying; Xu, Shilong; Yu, Lei; Zheng, Zhi Ming; Wang, Peng

    2017-11-01

    In this study, the spatial structure of randomly distributed clusters of fungi An0429 spores was simulated using a cluster aggregation (CCA) model, and the single scattering parameters of fungi An0429 spores were calculated using the discrete dipole approximation (DDA) method. The transmittance of 10.6 µm infrared (IR) light in the aggregated fungi An0429 spores swarm is simulated by using the Monte Carlo method. Several parameters that affect the transmittance of 10.6 µm IR light, such as the number and radius of original fungi An0429 spores, porosity of aggregated fungi An0429 spores, and density of aggregated fungi An0429 spores of the formation aerosol area were discussed. Finally, the transmittances of microbial materials with different qualities were measured in the dynamic test platform. The simulation results showed that the parameters analyzed were closely connected with the extinction performance of fungi An0429 spores. By controlling the value of the influencing factors, the transmittance could be lower than a certain threshold to meet the requirement of attenuation in application. In addition, the experimental results showed that the Monte Carlo method could well reflect the attenuation law of IR light in fungi An0429 spore agglomerates swarms.

  10. Controlling the opto-electronic properties of nc-SiOx:H films by promotion of 〈220〉 orientation in the growth of ultra-nanocrystallites at the grain boundary

    Science.gov (United States)

    Das, Debajyoti; Samanta, Subhashis

    2018-01-01

    A systematic development of undoped nc-SiOx:H thin films from (SiH4 + CO2) plasma diluted by a combination of H2 and He has been investigated through structural, optical and electrical characterization and correlation. Gradual inclusion of O into a highly crystalline silicon network progressively produces a two-phase structure where Si-nanocrystals (Si-nc) are embedded into the a-SiOx:H matrix. However, at the intermediate grain boundary region the growth of ultra-nanocrystallites controls the effectiveness of the material. The ultra-nanocrystallites are the part and portion of crystallinity accommodating the dominant fraction of thermodynamically preferred 〈220〉 crystallographic orientation, most favourable for stacked layer device performance. Atomic H plays a dominant role in maintaining an improved nanocrystalliny in the network even during O inclusion, while He in its excited state (He*) maintains a good energy balance at the grain boundary and produces a significant fraction of ultra-nanocrystalline component which has been demonstrated to organize the energetically favourable 〈220〉 crystallographic orientation in the network. The nc-SiOx:H films, maintaining proportionally good electrical conductivity over an wide range of optical band gap, remarkably low microstructure factor and simultaneous high crystalline volume fraction dominantly populated by ultra-nanocrystallites of 〈220〉 crystallographic orientation mostly at the grain boundary, have been obtained in technologically most popular 13.56 MHz PECVD SiH4 plasma even at a low substrate temperature ∼250 °C, convenient for device fabrication.

  11. Grain Interactions in Crystal Plasticity

    International Nuclear Information System (INIS)

    Boyle, K.P.; Curtin, W.A.

    2005-01-01

    The plastic response of a sheet metal is governed by the collective response of the underlying grains. Intragranular plasticity depends on intrinsic variables such as crystallographic orientation and on extrinsic variables such as grain interactions; however, the role of the latter is not well understood. A finite element crystal plasticity formulation is used to investigate the importance of grain interactions on intragranular plastic deformation in initially untextured polycrystalline aggregates. A statistical analysis reveals that grain interactions are of equal (or more) importance for determining the average intragranular deviations from the applied strain as compared to the orientation of the grain itself. Furthermore, the influence of the surrounding grains is found to extend past nearest neighbor interactions. It is concluded that the stochastic nature of the mesoscale environment must be considered for a proper understanding of the plastic response of sheet metals at the grain-scale

  12. Determination of grain boundary mobility during recrystallization by statistical evaluation of electron backscatter diffraction measurements

    International Nuclear Information System (INIS)

    Basu, I.; Chen, M.; Loeck, M.; Al-Samman, T.; Molodov, D.A.

    2016-01-01

    One of the key aspects influencing microstructural design pathways in metallic systems is grain boundary motion. The present work introduces a method by means of which direct measurement of grain boundary mobility vs. misorientation dependence is made possible. The technique utilizes datasets acquired by means of serial electron backscatter diffraction (EBSD) measurements. The experimental EBSD measurements are collectively analyzed, whereby datasets were used to obtain grain boundary mobility and grain aspect ratio with respect to grain boundary misorientation. The proposed method is further validated using cellular automata (CA) simulations. Single crystal aluminium was cold rolled and scratched in order to nucleate random orientations. Subsequent annealing at 300 °C resulted in grains growing, in the direction normal to the scratch, into a single deformed orientation. Growth selection was observed, wherein the boundaries with misorientations close to Σ7 CSL orientation relationship (38° 〈111〉) migrated considerably faster. The obtained boundary mobility distribution exhibited a non-monotonic behavior with a maximum corresponding to misorientation of 38° ± 2° about 〈111〉 axes ± 4°, which was 10–100 times higher than the mobility values of random high angle boundaries. Correlation with the grain aspect ratio values indicated a strong growth anisotropy displayed by the fast growing grains. The observations have been discussed in terms of the influence of grain boundary character on grain boundary motion during recrystallization. - Highlights: • Statistical microstructure method to measure grain boundary mobility during recrystallization • Method implementation independent of material or crystal structure • Mobility of the Σ7 boundaries in 5N Al was calculated as 4.7 × 10"–"8 m"4/J ⋅ s. • Pronounced growth selection in the recrystallizing nuclei in Al • Boundary mobility values during recrystallization 2–3 orders of magnitude

  13. Interface Orientation Distribution during Grain Growth in Bulk SrTiO3 Measured by Means of 3D X-Ray Diffraction Contrast Tomography

    DEFF Research Database (Denmark)

    Syha, Melanie; Rheinheimer, Wolfgang; Bäurer, Michael

    2012-01-01

    3D x-ray diffraction contrast tomography (DCT) is a non-destructive technique for the determination of grain shape and crystallography in polycrystalline bulk materials. Using this technique, a strontium titanate specimen was repeatedly measured between annealing steps.. A systematic analysis...

  14. Resource-oriented coaching for reduction of examination-related stress in medical students: an exploratory randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Kötter T

    2016-08-01

    Full Text Available Thomas Kötter,1 Frank Niebuhr2 1Institute of Social Medicine and Epidemiology, 2Institute of Family Medicine, University of Lübeck, Lübeck, Germany Introduction: The years spent in acquiring medical education is considered a stressful period in the life of many students. Students whose mental health deteriorates during this long period of study are less likely to become empathic and productive physicians. In addition to other specific stressors, academic examinations seem to further induce medical school-related stress and anxiety. Combined group and individual resource-oriented coaching early in medical education might reduce examination-related stress and anxiety and, consequently, enhance academic performance. Good quality evidence, however, remains scarce. In this study, therefore, we explored the question of whether coaching affects examination-related stress and health in medical students.Methods: We conducted a randomized controlled trial. Students who registered for the first medical academic examination in August 2014 at the University of Lübeck were recruited and randomized into three groups. The intervention groups 1 and 2 received a 1-hour psychoeducative seminar. Group 1 additionally received two 1-hour sessions of individual coaching during examination preparation. Group 3 served as a control group. We compared changes in self-rated general health (measured by a single item, anxiety and depression (measured by the hospital anxiety and depression scale, as well as medical school stress (measured by the perceived medical school stress instrument. In order to further investigate the influence of group allocation on perceived medical school stress, we conducted a linear regression analysis.Results: We saw a significant deterioration of general health and an increase in anxiety and depression scores in medical students while preparing for an examination. We found a small, but statistically significant, effect of group allocation on

  15. Nanoscale charge localization induced by random orientations of organic molecules in hybrid perovskite CH3NH3PbI3

    Science.gov (United States)

    Ma, Jie; Wang, Lin-Wang

    2015-03-01

    Perovskite-based solar cells have achieved high solar-energy conversion efficiencies and attracted wide attentions nowadays. Despite the rapid progress in solar-cell devices, many fundamental issues of the hybrid perovskites have not been fully understood. Experimentally, it is well known that in CH3NH3PbI3, the organic molecules CH3NH3 are randomly orientated at the room temperature, but the impact of the random molecular orientation has not been investigated. Using linear-scaling ab-initiomethods, we have calculated the electronic structures of the tetragonal phase of CH3NH3PbI3 with randomly orientated organic molecules in large supercells up to ~20,000 atoms. Due to the dipole moment of the organic molecule, the random orientation creates a novel system with long-range potential fluctuations unlike alloys or other conventional disordered systems. We find that the charge densities of the conduction-band minimum and the valence-band maximum are localized separately in nanoscales due to the potential fluctuations. The charge localization causes electron-hole separation and reduces carrier recombination rates, which may contribute to the long carrier lifetime observed in experiments. We have also proposed a model to explain the charge localization.

  16. The effect of integrated emotion-oriented care versus usual care on elderly persons with dementia in the nursing home and on nursing assistants: a randomized clinical trial

    NARCIS (Netherlands)

    Finnema, E.J.; Dr�es, R.M.; Ettema, T.P.; Ooms, M.E.; Adèr, H.J.; Ribbe, M.W.; van Tilburg, W.

    2005-01-01

    Objectives: To examine the effect of integrated emotion-oriented care on nursing home residents with dementia and nursing assistants. Design: A multi-site randomized clinical trial with matched groups, and measurements at baseline and after seven months. Setting: Sixteen psychogeriatric wards in

  17. The effect of integrated emotion-oriented care versus usual care on elderly persons with dementia in the nursing home and on nursing assistants: a randomized clinical trial

    NARCIS (Netherlands)

    Finnema, E.J.; Dr�es, R.M.; Ettema, T.P.; Ooms, M.E.; Adèr, H.J.; Ribbe, M.W.; Tilburg, van W.

    2005-01-01

    OBJECTIVES: To examine the effect of integrated emotion-oriented care on nursing home residents with dementia and nursing assistants. DESIGN: A multi-site randomized clinical trial with matched groups, and measurements at baseline and after seven months. SETTING: Sixteen psychogeriatric wards in

  18. Characterization of Grain Amaranth (Amaranthus spp. Germplasm in South West Nigeria Using Morphological, Nutritional, and Random Amplified Polymorphic DNA (RAPD Analysis

    Directory of Open Access Journals (Sweden)

    Pamela E. Akin-Idowu

    2016-01-01

    Full Text Available Efficient utilization of plant genetic resources for nutrition and crop improvement requires systematic understanding of the important traits. Amaranthus species are distributed worldwide with an interesting diversity of landraces and cultivars whose leaves and seeds are consumed. Despite their potential to enhance food security and economic livelihoods, grain amaranth breeding to improve nutritional quality and adoption by farmers in sub-Saharan Africa is scanty. This study assessed the variation among 29 grain amaranth accessions using 27 phenotypic (10 morphological and 17 nutritional characters and 16 random amplified polymorphic DNA (RAPD primers. Multivariate analysis of phenotypic characters showed the first four principal components contributing 57.53% of observed variability, while cluster analysis yielded five groups at 87.5% similarity coefficient. RAPD primers generated a total of 193 amplicons with an average of 12.06 amplicons per primer, 81% of which were polymorphic. Genetic similarities based on Jaccard’s coefficient ranged from 0.61 to 0.88. The RAPD-based unweighted pair group method with arithmetic mean dendrogram grouped the accessions into nine clusters, with the same species clustering together. RAPD primers distinguished the accessions more effectively than phenotypic markers. Accessions in the different clusters as obtained can be exploited for heterotic gain in desired nutritional traits.

  19. Grain-Boundary Resistance in Copper Interconnects: From an Atomistic Model to a Neural Network

    Science.gov (United States)

    Valencia, Daniel; Wilson, Evan; Jiang, Zhengping; Valencia-Zapata, Gustavo A.; Wang, Kuang-Chung; Klimeck, Gerhard; Povolotskyi, Michael

    2018-04-01

    Orientation effects on the specific resistance of copper grain boundaries are studied systematically with two different atomistic tight-binding methods. A methodology is developed to model the specific resistance of grain boundaries in the ballistic limit using the embedded atom model, tight- binding methods, and nonequilibrium Green's functions. The methodology is validated against first-principles calculations for thin films with a single coincident grain boundary, with 6.4% deviation in the specific resistance. A statistical ensemble of 600 large, random structures with grains is studied. For structures with three grains, it is found that the distribution of specific resistances is close to normal. Finally, a compact model for grain-boundary-specific resistance is constructed based on a neural network.

  20. Proposal for the award of a contract for the supply of moulded assemblies of tape-wound cut cores of grain-oriented silicon-steel for the LHC beam dumping system

    CERN Document Server

    2001-01-01

    This document concerns the award of a contract for the supply of moulded assemblies of tape-wound cut cores of grain-oriented silicon-steel for the three different types of fast pulsed magnets for the beam dumping system of the LHC. Following a market survey carried out among 14 firms in four Member States and six firms in two non-Member States, a call for tenders (IT-2674/SL/LHC) was sent on 26 January 2001 to one firm in one Member State. By the closing date, CERN had received a tender from the firm. The Finance Committee is invited to agree to the negotiation of a contract with TELMAG MAGNETIC COMPONENTS (UK), the only bidder, for the supply of 2885 moulded assemblies of tape-wound cut cores of grain-oriented silicon-steel, of three different types, for a total amount of 2 414 664 euros (3 692 147 Swiss francs), not subject to revision, with options for 560 additional moulded core assemblies of three different types, for an additional amount of 468 496 euros (716 355 Swiss francs), not subject to revision,...

  1. Quick synthesis of highly aligned or randomly oriented nanofibrous structures composed of C60 molecules via self-assembly

    International Nuclear Information System (INIS)

    Kurosu, Shunji; Fukuda, Takahiro; Maekawa, Toru

    2013-01-01

    Assemblies, which are composed of nanoparticles such as nanofibres, have been intensively studied in recent years. This has particularly been the case in the field of biomedicine, where the aim is to develop efficient methodologies for capturing and separating target biomolecules and cells and/or encouraging bio-chemical reactions, utilizing the extremely high surface area to volume ratio of assemblies. There is an urgent need for the development of a quick synthesis method of forming nanofibrous structures on the surface of biomedical microchips and devices for the investigation of the interactions between biomolecules/cells and the nanostructures. Here, we produce nanofibrous structures composed of C 60 molecules, which are aligned in one direction or randomly oriented, by dissolving C 60 molecules and sulphur in benzene and evaporating a droplet of the solution on a glass substrate under appropriate conditions. The synthesis time is as short as 30 s. Sulphur is extracted and nanofibres are crystallized by leaving them in supercritical carbon dioxide. (paper)

  2. Standard practice for X-Ray determination of retained austenite in steel with near random crystallographic orientation

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This practice covers the determination of retained austenite phase in steel using integrated intensities (area under peak above background) of X-ray diffraction peaks using chromium Kα or molybdenum Kα X-radiation. 1.2 The method applies to carbon and alloy steels with near random crystallographic orientations of both ferrite and austenite phases. 1.3 This practice is valid for retained austenite contents from 1 % by volume and above. 1.4 If possible, X-ray diffraction peak interference from other crystalline phases such as carbides should be eliminated from the ferrite and austenite peak intensities. 1.5 Substantial alloy contents in steel cause some change in peak intensities which have not been considered in this method. Application of this method to steels with total alloy contents exceeding 15 weight % should be done with care. If necessary, the users can calculate the theoretical correction factors to account for changes in volume of the unit cells for austenite and ferrite resulting from vari...

  3. Influence of applied compressive stress on the hysteresis curves and magnetic domain structure of grain-oriented transverse Fe-3%Si steel

    International Nuclear Information System (INIS)

    Perevertov, O; Schäfer, R

    2012-01-01

    The influence of an applied compressive stress on the hysteresis curve and domain structure in conventional (1 1 0) [0 0 1] Fe-3%Si steel cut transverse to the rolling direction is studied. Quasistatic hysteresis loops under compressive stress up to 75 MPa were measured. The magnetic domains and magnetization processes were observed by longitudinal Kerr microscopy at different levels of stress. It is shown that the bulk hysteresis loop can be described with a good accuracy by the action of an effective field, which is the product of the stress and a function of magnetization. Domain observations have shown that the reasons for the effective field are demagnetizing fields due to the disappearance of supplementary domains along [0 1 0] and [1 0 0] at low fields and different domain systems in different grains at moderate fields. The latter are caused by differences in grain sensitivity to stress depending on the degree of misorientation. A decrease in the effective field above 1 T is connected with a transformation of all grains into the same domain system—the column pattern. (paper)

  4. Giant grains

    International Nuclear Information System (INIS)

    Leitch-Devlin, M.A.; Millar, T.J.; Williams, D.A.

    1976-01-01

    Infrared observations of the Orion nebula have been interpreted by Rowan-Robinson (1975) to imply the existence of 'giant' grains, radius approximately 10 -2 cm, throughout a volume about a parsec in diameter. Although Rowan-Robinson's model of the nebula has been criticized and the presence of such grains in Orion is disputed, the proposition is accepted, that they exist, and in this paper situations in which giant grains could arise are examined. It is found that, while a giant-grain component to the interstellar grain density may exist, it is difficult to understand how giant grains arise to the extent apparently required by the Orion nebula model. (Auth.)

  5. “To see a world in a grain of sand”: Towards Future-oriented What-If Analysis in Narrative Research

    NARCIS (Netherlands)

    Sools, Anna Maria

    2012-01-01

    In this article, I explore narrative building blocks for future-oriented what-if (i.e., possibilities-generating) analysis developed in a health promotion study. The aim of this study was to gain insight into future possibilities for good health among participants known for their poor health status.

  6. Nuclear magnetic relaxation induced by exchange-mediated orientational randomization: longitudinal relaxation dispersion for spin I = 1.

    Science.gov (United States)

    Nilsson, Tomas; Halle, Bertil

    2012-08-07

    The frequency dependence of the longitudinal relaxation rate, known as the magnetic relaxation dispersion (MRD), can provide a frequency-resolved characterization of molecular motions in complex biological and colloidal systems on time scales ranging from 1 ns to 100 μs. The conformational dynamics of immobilized proteins and other biopolymers can thus be probed in vitro or in vivo by exploiting internal water molecules or labile hydrogens that exchange with a dominant bulk water pool. Numerous water (1)H and (2)H MRD studies of such systems have been reported, but the widely different theoretical models currently used to analyze the MRD data have resulted in divergent views of the underlying molecular motions. We have argued that the essential mechanism responsible for the main dispersion is the exchange-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings when internal water molecules or labile hydrogens escape from orientationally confining macromolecular sites. In the EMOR model, the exchange process is thus not just a means of mixing spin populations but it is also the direct cause of spin relaxation. Although the EMOR theory has been used in several studies to analyze water (2)H MRD data from immobilized biopolymers, the fully developed theory has not been described. Here, we present a comprehensive account of a generalized version of the EMOR theory for spin I = 1 nuclides like (2)H. As compared to a previously described version of the EMOR theory, the present version incorporates three generalizations that are all essential in applications to experimental data: (i) a biaxial (residual) electric field gradient tensor, (ii) direct and indirect effects of internal motions, and (iii) multiple sites with different exchange rates. In addition, we describe and assess different approximations to the exact EMOR theory that are useful in various regimes. In particular, we consider the experimentally

  7. Grain interaction effects in polycrystalline Cu

    DEFF Research Database (Denmark)

    Thorning, C.; Somers, Marcel A.J.; Wert, John A.

    2005-01-01

    Crystal orientation maps for a grain in a deformed Cu polycrystal have been analysed with the goal of understanding the effect of grain interactions on orientation subdivision. The polycrystal was incrementally strained in tension to 5, 8, 15 and 25% extension; a crystal orientation map...... was measured after each strain increment. The measurements are represented as rotations from the initial crystal orientation. A coarse domain structure forms in the initial 5% strain increment and persists at higher strains. Crystal rotations for all coarse domains in the grain are consistent with the full...... range of Tailor solutions for axisymmetric strain; grain interactions are not required to account for the coarse domain structure. Special orientation domains extend 20-100 µm into the grain at various locations around its periphery. The special orientation domain morphologies include layers along...

  8. Effect of oriental medicine music therapy on patients with Hwa-byung: a study protocol for a randomized controlled trial

    Science.gov (United States)

    2012-01-01

    Background Hwa-byung, a Korean culture-bound syndrome with both psychological and somatic symptoms, is also known as ‘anger syndrome’. It includes various physical symptoms including anxiety, a feeling of overheating, a sensation of pressure on the chest, heart palpitations, respiratory stuffiness, insomnia, and anxiety. Methods/design The proposed study is a single-center, double-blind, randomized, controlled trial with two parallel arms: an oriental medicine music therapy (OMMT) group and a control music therapy (CMT) group. In total, 48 patients will be enrolled into the trial. The first visit will be the screening visit. At baseline (visit 2), all participants fulfilling both the inclusion and the exclusion criteria will be split and randomly divided into two equal groups: the OMMT and the CMT (n = 24 each). Each group will receive treatment sessions over the course of 4 weeks, twice per week, for eight sessions in total. The primary outcome is the State-Trait Anxiety Inventory (STAI), and the secondary outcomes are the Hwa-byung scale (H-scale), the Center for Epidemiologic Studies Depression Scale (CES-D), the Hwa-byung visual analogue scale (H-VAS) for primary symptoms, the World Health Organization Quality of Life scale, brief version (WHOQOL-BREF), and levels of salivary cortisol. Patients will be asked to complete questionnaires at the baseline visit (visit 2), after the last treatment session (visit 9), and at 4 weeks after the end of all trial sessions (visit 10). From the baseline (visit 2) through the follow-up (visit 10), the entire process will take a total of 53 days. Discussion This proposed study targets patients with Hwa-byung, especially those who have exhibited symptoms of anxiety. Therefore, the primary outcome is set to measure the level of anxiety. OMMT is music therapy combined with traditional Korean medicinal theories. Unlike previously reported music therapies, for which patients simply listen to music passively, in OMMT, patients

  9. Effect of oriental medicine music therapy on patients with Hwa-byung: a study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Park Jeong-Su

    2012-09-01

    Full Text Available Abstract Background Hwa-byung, a Korean culture-bound syndrome with both psychological and somatic symptoms, is also known as ‘anger syndrome’. It includes various physical symptoms including anxiety, a feeling of overheating, a sensation of pressure on the chest, heart palpitations, respiratory stuffiness, insomnia, and anxiety. Methods/design The proposed study is a single-center, double-blind, randomized, controlled trial with two parallel arms: an oriental medicine music therapy (OMMT group and a control music therapy (CMT group. In total, 48 patients will be enrolled into the trial. The first visit will be the screening visit. At baseline (visit 2, all participants fulfilling both the inclusion and the exclusion criteria will be split and randomly divided into two equal groups: the OMMT and the CMT (n = 24 each. Each group will receive treatment sessions over the course of 4 weeks, twice per week, for eight sessions in total. The primary outcome is the State-Trait Anxiety Inventory (STAI, and the secondary outcomes are the Hwa-byung scale (H-scale, the Center for Epidemiologic Studies Depression Scale (CES-D, the Hwa-byung visual analogue scale (H-VAS for primary symptoms, the World Health Organization Quality of Life scale, brief version (WHOQOL-BREF, and levels of salivary cortisol. Patients will be asked to complete questionnaires at the baseline visit (visit 2, after the last treatment session (visit 9, and at 4 weeks after the end of all trial sessions (visit 10. From the baseline (visit 2 through the follow-up (visit 10, the entire process will take a total of 53 days. Discussion This proposed study targets patients with Hwa-byung, especially those who have exhibited symptoms of anxiety. Therefore, the primary outcome is set to measure the level of anxiety. OMMT is music therapy combined with traditional Korean medicinal theories. Unlike previously reported music therapies, for which patients simply listen to music passively, in

  10. Effect of texture on grain boundary misorientation distributions in polycrystalline high temperature superconductors

    International Nuclear Information System (INIS)

    Goyal, A.; Specht, E.D.; Kroeger, D.M.; Mason, T.A.

    1996-01-01

    Computer simulations were performed to determine the most probable grain boundary misorientation distribution (GBMD) in model polycrystalline superconductors. GBMDs in polycrystalline superconductors can be expected to dictate the macroscopic transport critical current density, J c . Calculations were performed by simulating model polycrystals and then determining the GBMD. Such distributions were calculated for random materials having cubic, tetragonal, and orthorhombic crystal symmetry. In addition, since most high temperature superconductors are tetragonal or pseudotetragonal, the effect of macroscopic uniaxial and biaxial grain orientation texture on the GBMD was determined for tetragonal materials. It is found that macroscopic texture drastically alters the grain boundary misorientation distribution. The fraction of low angle boundaries increases significantly with uniaxial and biaxial texture. The results of this study are important in correlating the macroscopic transport J c with the measured grain orientation texture as determined by x-ray diffraction copyright 1996 American Institute of Physics

  11. Anisotropic Negative Thermal Expansion Behavior of the As-Fabricated Ti-Rich and Equiatomic Ti-Ni Alloys Induced by Preferential Grain Orientation

    Science.gov (United States)

    Zhao, Zhong-Xun; Ma, Xiao; Cao, Shan-Shan; Ke, Chang-Bo; Zhang, Xin-Ping

    2018-03-01

    The present study focuses on the anisotropic negative thermal expansion (NTE) behaviors of Ti-rich (Ti54Ni46) and equiatomic Ti-Ni (Ti50Ni50) alloys fabricated by vacuum arc melting and without subsequent plastic deformation. Both alloys exhibit NTE responses in vertical and horizontal directions, and the total strains and CTEs of the NTE stage along the two mutually perpendicular measuring directions are obviously different, indicating obvious anisotropic NTE behavior of the alloys. Besides, the numerical differences between the starting temperature of NTE and austenitic transformation and between the finishing temperature of NTE and austenitic transformation are very small, which indicates that an apparent relationship exists between the NTE behavior and the phase transformation. The microstructure in the vertical cross sections shows obviously preferential orientation characteristics: Ti2Ni phases of both alloys grow along the vertical direction, and B19' martensite of Ti50Ni50 alloy has distinct preferential orientation, which results from a large temperature gradient between the top and the bottom of the button ingots during solidification. The microstructure with preferential orientation induces the anisotropic NTE behavior of the samples.

  12. Dietary black-grained wheat intake improves glycemic control and inflammatory profile in patients with type 2 diabetes: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Liu Y

    2018-02-01

    Full Text Available Yanping Liu,1,* Ju Qiu,2,* Yanfen Yue,3 Kang Li,3 Guixing Ren41Department of Nutrition, Peking Union Medical College Hospital, Beijing, 2Institute of Food and Nutrition Development, Ministry of Agriculture, Beijing, 3Department of Nutrition, Pinggu Hospital of Traditional Chinese Medicine, Beijing, 4Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China *These authors contributed equally to this workIntroduction: Although black-grained wheat (BGW is recognized as a nutritional food for humans in China, it has yet to be utilized well for industrial applications, which can be attributed to the limited research data available on its health benefits. Thus, the hypothesis was tested that a daily substitution of BGW for a partial staple food would improve glycemia and inflammatory profile of type 2 diabetes mellitus (T2DM patients by a randomized controlled trial. Materials and methods: A total of 120 patients were randomly divided between control group (diet control and nutritional education and BGW group (daily substitution of BGW for a partial staple food. Results: Based on the significant difference between BGW and control groups (P<0.05, the primary outcomes were that BGW treatment in diet resulted in a significant lowering of glycated albumin (GA, 18.05 to 16.06 mmol/L level in T2DM patients after a 5-week intervention, and this treatment regimen was much more efficient than the strategy of diet control alone. In addition, BGW supplementation prevented the increase in tumor necrosis factor (TNF-α and interleukin (IL-6 induced by T2DM. There were no significant differences in blood glucose, glycated hemoglobin or insulin levels between the 2 groups. The subgroup analyses of the BGW daily intake showed that, except the TNF-α, significant improvements in GA and IL-6 were observed when the BGW intake dose was >69 g/day.Conclusion: These findings support the hypothesis that BGW may improve glycemia and the

  13. Core stability exercise is as effective as task-oriented motor training in improving motor proficiency in children with developmental coordination disorder: a randomized controlled pilot study.

    Science.gov (United States)

    Au, Mei K; Chan, Wai M; Lee, Lin; Chen, Tracy Mk; Chau, Rosanna Mw; Pang, Marco Yc

    2014-10-01

    To compare the effectiveness of a core stability program with a task-oriented motor training program in improving motor proficiency in children with developmental coordination disorder (DCD). Randomized controlled pilot trial. Outpatient unit in a hospital. Twenty-two children diagnosed with DCD aged 6-9 years were randomly allocated to the core stability program or the task-oriented motor program. Both groups underwent their respective face-to-face training session once per week for eight consecutive weeks. They were also instructed to carry out home exercises on a daily basis during the intervention period. Short Form of the Bruininks-Oseretsky Test of Motor Proficiency (Second Edition) and Sensory Organization Test at pre- and post-intervention. Intention-to-treat analysis revealed no significant between-group difference in the change of motor proficiency standard score (P=0.717), and composite equilibrium score derived from the Sensory Organization Test (P=0.100). Further analysis showed significant improvement in motor proficiency in both the core stability (mean change (SD)=6.3(5.4); p=0.008) and task-oriented training groups (mean change(SD)=5.1(4.0); P=0.007). The composite equilibrium score was significantly increased in the task-oriented training group (mean change (SD)=6.0(5.5); P=0.009), but not in the core stability group (mean change(SD) =0.0(9.6); P=0.812). In the task-oriented training group, compliance with the home program was positively correlated with change in motor proficiency (ρ=0.680, P=0.030) and composite equilibrium score (ρ=0.638, P=0.047). The core stability exercise program is as effective as task-oriented training in improving motor proficiency among children with DCD. © The Author(s) 2014.

  14. Omitted Data in Randomized Controlled Trials for Anxiety and Depression: A Systematic Review of the Inclusion of Sexual Orientation and Gender Identity

    Science.gov (United States)

    Heck, Nicholas C.; Mirabito, Lucas A.; LeMaire, Kelly; Livingston, Nicholas A.; Flentje, Annesa

    2016-01-01

    Objective The current study examined the frequency with which randomized controlled trials (RCTs) of behavioral and psychological interventions for anxiety and depression include data pertaining to participant sexual orientation and non-binary gender identities. Method Using systematic review methodology, the databases PubMed and PsycINFO were searched to identify RCTs published in 2004, 2009, and 2014. Random selections of 400 articles per database per year (2400 articles in total) were considered for inclusion in the review. Articles meeting inclusion criteria were read and coded by the research team to identify whether the trial reported data pertaining to participant sexual orientation and non-binary gender identities. Additional trial characteristics were also identified and indexed in our database (e.g., sample size, funding source etc.). Results Of the 232 articles meeting inclusion criteria, only one reported participants’ sexual orientation and zero articles included non-binary gender identities. A total of 52,769 participants were represented in the trials, 93 of which were conducted in the U.S. and 43 acknowledged the National Institutes of Health as a source of funding. Conclusions Despite known mental health disparities on the basis of sexual orientation and non-binary gender identification, researchers evaluating interventions for anxiety and depression are not reporting on these important demographic characteristics. Reporting practices must change in order to ensure that our interventions generalize to lesbian, gay, bisexual, and transgender persons. PMID:27845517

  15. Orientation and thickness dependence of magnetic levitation force and trapped magnetic field of single grain YBa{sub 2}Cu{sub 3}O{sub 7-y} bulk superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Y.; Go, S. J.; Joo, H. T. [Korea Science Academy of Korea Advanced Institute of Science and Technology, Pusan (Korea, Republic of); Lee, Y. J.; Park, S. D.; Jun, B. H.; KIm, C. J. [Neutron Utilization Technology Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-03-15

    The effects of the crystallographic orientation and sample thickness on the magnetic levitation forces (F) and trapped magnetic field (B) of single grain YBCO bulk superconductors were examined. Single grain YBCO samples with a (001), (110) or (100) surface were used as the test samples. The samples used for the force-distance (F-d) measurement were cooled at 77 K without a magnetic field (zero field cooling, ZFC), whereas the samples used for the B measurement were cooled under the external magnetic field of a Nd-B-Fe permanent magnet (field cooling, FC). It was found that F and B of the (001) surface were higher than those of the (110) or (100) surface, which is attributed to the higher critical current density (J{sub c}) of the (001) surface. For the (001) samples with t=5–18 mm, the maximum magnetic levitation forces (F{sub max}s) of the ZFC samples were larger than 40 N. About 80% of the applied magnetic field was trapped in the FC samples. However, the F and B decreased rapidly as t decreased below 5 mm. There exists a critical sample thickness (t=5 mm for the experimental condition of this study) for maintaining the large levitation/trapping properties, which is dependent on the material properties and magnitude of the external magnetic fields.

  16. Additive Effect of Qidan Dihuang Grain, a Traditional Chinese Medicine, and Angiotensin Receptor Blockers on Albuminuria Levels in Patients with Diabetic Nephropathy: A Randomized, Parallel-Controlled Trial

    Science.gov (United States)

    Xiang, Lei; Jiang, Pingping; Zhou, Lin; Sun, Xiaomin; Bi, Jianlu; Cui, Lijuan; Nie, Xiaoli; Luo, Ren; Liu, Yanyan

    2016-01-01

    Albuminuria is characteristic of early-stage diabetic nephropathy (DN). The conventional treatments with angiotensin receptor blockers (ARB) are unable to prevent the development of albuminuria in normotensive individuals with type 2 diabetes mellitus (T2DM). Purpose. The present study aimed to evaluate the effect of ARB combined with a Chinese formula Qidan Dihuang grain (QDDHG) in improving albuminuria and Traditional Chinese Medicine Symptom (TCMS) scores in normotensive individuals with T2DM. Methods. Eligible patients were randomized to the treatment group and the control group. Results. Compared with baseline (week 0), both treatment and control groups markedly improved the 24-hour albuminuria, total proteinuria (TPU), and urinary albumin to creatinine ratio (A/C) at 4, 8, and 12 weeks. Between treatment and the control group, the levels of albuminuria in the treatment group were significantly lower than in the control group at 8 and 12 weeks (p < 0.05). In addition, treatment group markedly decreased the scores of TCMS after treatment. Conclusion. This trial suggests that QDDHG combined with ARB administration decreases the levels of albuminuria and the scores for TCMS in normotensive individuals with T2DM. PMID:27375762

  17. Influence of specimen size and grain orientation to the life of a polycrystalline Ni-base alloy at LCF stress; Einfluss der Probengroesse und der Kornorientierung auf die Lebensdauer einer polykristallinen Ni-Basislegierung bei LCF-Beanspruchung

    Energy Technology Data Exchange (ETDEWEB)

    Seibel, Thomas

    2014-07-01

    In the present work the LCF (Low Cycle Fatigue) crack initiation life of the conventionally cast Ni-base alloy RENE 80 was analyzed as a function of specimen size and grain orientation. Five specimen geometries with distinctly different gauge sections were used: 3 geometries with cylindrical gauge section (G1-G3) and two notched geometries with a stress concentration factor of α{sub 1} = 1,62 (KG1) and α{sub 2} = 2,60 (KG2), resulting in a maximum difference of the damage relevant surface area up to a factor of approximately 72. Correction factors were determined by FEM calculations for all specimen geometries with highly reduced gauge sections where direct strain measurement was not possible. Additionally a uniform failure criterion with a relatively small crack size of 0,962 mm{sup 2} was defined. Totally, 116 isothermal LCF tests were carried out at the different specimen types at a temperature of 850 C in total strain control with a load ratio (minimum strain / maximum strain) of R{sub ε} = -1. The load cycles were applied with triangular waveform at a frequency of 0.1 Hz for high strain amplitudes and 1 Hz for low strain amplitudes, respectively. After the LCF-Tests the fracture surfaces of all samples were analyzed in more detail by SEM to identify the crack initiation mechanisms as well as the crack initiation sites. In this context it could be shown, that fatigue cracks were generally initiated at slip bands in surface grains. Accordingly, the grain orientations at the crack initiation sites were measured by electron back scatter diffraction (EBSD) and the maximum shear stresses in the respective principal slip system (111) <110> was calculated using the Schmid approach. For this, longitudinal sections were be prepared exactly at the crack initiation sites of samples loaded with low strain amplitudes where clearly defined single crack initiation sites were observed. Afterwards the maximum shear stress in the principal slip system at the crack initiation

  18. Friction force microscopy: a simple technique for identifying graphene on rough substrates and mapping the orientation of graphene grains on copper

    International Nuclear Information System (INIS)

    Marsden, A J; Wilson, N R; Phillips, M

    2013-01-01

    At a single atom thick, it is challenging to distinguish graphene from its substrate using conventional techniques. In this paper we show that friction force microscopy (FFM) is a simple and quick technique for identifying graphene on a range of samples, from growth substrates to rough insulators. We show that FFM is particularly effective for characterizing graphene grown on copper where it can correlate the graphene growth to the three-dimensional surface topography. Atomic lattice stick–slip friction is readily resolved and enables the crystallographic orientation of the graphene to be mapped nondestructively, reproducibly and at high resolution. We expect FFM to be similarly effective for studying graphene growth on other metal/locally crystalline substrates, including SiC, and for studying growth of other two-dimensional materials such as molybdenum disulfide and hexagonal boron nitride. (paper)

  19. Improving the thermoelectric performance of metastable rock-salt GeTe-rich Ge-Sb-Te thin films through tuning of grain orientation and vacancies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, I. Nan [Department of Physics, National Taiwan University, Taipei (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei (China); Chong, Cheong-Wei [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei (China); Center for Condensed Matter Sciences, National Taiwan University, Taipei (China); Wong, Deniz P.; Lyu, Liang-Ming; Chien, Wei-Lun; Anbalagan, Ramakrishnan; Aminzare, Masoud; Chen, Kuei-Hsien [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei (China); Chen, Yang-Fang [Department of Physics, National Taiwan University, Taipei (China); Chen, Li-Chyong [Center for Condensed Matter Sciences, National Taiwan University, Taipei (China)

    2016-12-15

    Phase-change memory materials such as the pseudobinary GeTe-Sb{sub 2}Te{sub 3} compounds have recently gained attention for their good thermoelectric properties, which can be used for power-generation/cooling applications. In this work, GeTe-rich Ge-Sb-Te thin films deposited using a radio-frequency magnetron sputtering method readily exhibit the metastable face-centered cubic (FCC) phase at room temperature. This is in stark contrast to its bulk form, which only transforms to its FCC phase after a transition temperature of around 350 C. Based on previous works, the FCC phase contributes to the superior thermoelectric properties of this material system. In this study, by decreasing the working deposition pressure, the preferred orientation of (200) plane is observed that translates to improved carrier mobility. Moreover, increasing the annealing temperature has been shown to decrease the carrier concentration due to Te deficiency, leading to a significant improvement in the Seebeck coefficient of the film. By combining these effects, an optimized thermoelectric power factor (21 μW/cm K{sup 2}) was obtained at an operating temperature of 350 C. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Crystallographic investigation of grain selection during initial solidification

    International Nuclear Information System (INIS)

    Esaka, H; Shinozuka, K; Kataoka, Y

    2016-01-01

    Normally, macroscopic solidified structure consists of chill, columnar and equiaxed zones. In a chill zone, many fine grains nucleate on the mold surface and grow their own preferred growth direction. Only a few of them continue to grow because of grain selection. In order to understand the grain selection process, crystallographic investigation has been carried out in the zone of initial solidification in this study. 10 g of Al-6 wt%Si alloy was melted at 850 °C and poured on the thick copper plate. Longitudinal cross section of the solidified shell was observed by a SEM and analyzed by EBSD. The result of EBSD mapping reveals that crystallographic orientation was random in the range of initial solidification. Further, some grains are elongated along their <100> direction. Columnar grains, whose growth directions are almost parallel to the heat flow direction, develop via grain selection. Here, a dendrite whose growth direction is close to the heat flow direction overgrows the other dendrite whose growth direction is far from the heat flow direction. However, sometimes we observed that dendrite, whose zenith angle is large, overgrew the other dendrite. It can be deduced that the time of nucleation on the mold surface is not constant. (paper)

  1. Effects of mirror therapy integrated with task-oriented exercise on the balance function of patients with poststroke hemiparesis: a randomized-controlled pilot trial.

    Science.gov (United States)

    Cha, Hyun-Gyu; Oh, Duck-Won

    2016-03-01

    This study aimed to explore the effects of mirror therapy integrated with task-oriented exercise on balance function in poststroke hemiparesis. Twenty patients with poststroke hemiparesis were assigned randomly to an experimental group (EG) and a control group (CG), with 10 individuals each. Participants of the EG and CG received a task-oriented exercise program with a focus on the strengthening of the lower limb and the practice of balance-related functional tasks. An additional option for the EG was front and side wall mirrors to provide visual feedback for their own movements while performing the exercise. The program was performed for 30 min, twice a day, five times per week for 4 weeks. Outcome measures included the Berg balance scale, the timed up-and-go test, and quantitative data (balance index and dynamic limits of stability). In the EG and CG, all variables showed significant differences between pretest and post-test (Phemiparesis.

  2. Interstellar grains

    Energy Technology Data Exchange (ETDEWEB)

    Hoyle, F.; Wickramasinghe, N.C.

    1980-11-01

    Interstellar extinction of starlight was observed and plotted as a function of inverse wavelength. Agreement with the calculated effects of the particle distribution is shown. The main kinds of grain distinguished are: (1) graphite spheres of radius 0.02 microns, making up 10% of the total grain mass (2) small dielectric spheres of radius 0.04 microns making up 25% and (3) hollow dielectric cylinders containing metallic iron, with diameters of 2/3 microns making up 45%. The remaining 20% consists of other metals, metal oxides, and polysiloxanes. Absorption factor evidence suggests that the main dielectric component of the grains is organic material.

  3. Task-oriented training with computer gaming in people with rheumatoid arthritisor osteoarthritis of the hand: study protocol of a randomized controlled pilot trial.

    Science.gov (United States)

    Srikesavan, Cynthia Swarnalatha; Shay, Barbara; Robinson, David B; Szturm, Tony

    2013-03-09

    Significant restriction in the ability to participate in home, work and community life results from pain, fatigue, joint damage, stiffness and reduced joint range of motion and muscle strength in people with rheumatoid arthritis or osteoarthritis of the hand. With modest evidence on the therapeutic effectiveness of conventional hand exercises, a task-oriented training program via real life object manipulations has been developed for people with arthritis. An innovative, computer-based gaming platform that allows a broad range of common objects to be seamlessly transformed into therapeutic input devices through instrumentation with a motion-sense mouse has also been designed. Personalized objects are selected to target specific training goals such as graded finger mobility, strength, endurance or fine/gross dexterous functions. The movements and object manipulation tasks that replicate common situations in everyday living will then be used to control and play any computer game, making practice challenging and engaging. The ongoing study is a 6-week, single-center, parallel-group, equally allocated and assessor-blinded pilot randomized controlled trial. Thirty people with rheumatoid arthritis or osteoarthritis affecting the hand will be randomized to receive either conventional hand exercises or the task-oriented training. The purpose is to determine a preliminary estimation of therapeutic effectiveness and feasibility of the task-oriented training program. Performance based and self-reported hand function, and exercise compliance are the study outcomes. Changes in outcomes (pre to post intervention) within each group will be assessed by paired Student t test or Wilcoxon signed-rank test and between groups (control versus experimental) post intervention using unpaired Student t test or Mann-Whitney U test. The study findings will inform decisions on the feasibility, safety and completion rate and will also provide preliminary data on the treatment effects of the task-oriented

  4. Economic evaluation of schema therapy and clarification-oriented psychotherapy for personality disorders: A multicenter, randomized controlled trial

    NARCIS (Netherlands)

    Bamelis, L.L.M.; Arntz, A.; Wetzelaer, P.; Verdoorn, R.; Evers, S.M.A.A.

    2015-01-01

    Purpose: To compare from a societal perspective the cost-effectiveness and cost-utility of schema therapy, clarification-oriented psychotherapy, and treatment as usual for patients with avoidant, dependent, obsessive-compulsive, paranoid, histrionic, and/or narcissistic personality disorder. Method:

  5. Grain centre mapping - 3DXRD measurements of average grain characteristics

    DEFF Research Database (Denmark)

    Oddershede, Jette; Schmidt, Søren; Lyckegaard, Allan

    2014-01-01

    characteristics of each grain (such as their centre-of-mass positions, volumes, phases, orientations and/or elastic strain tensor components), while the exact locations of the grain boundaries are unknown. In the present chapter a detailed description of the setup and software for both grain centre mapping...... and the closely related boxscan method is given. Both validation experiments and applications for in situ studies of microstructural changes during plastic deformation and crack growth are given. Finally an outlook with special emphasis on coupling the measured results with modelling is given....

  6. Scattering from randomly oriented scatterers of arbitrary shape in the low-frequency limit with application to vegetation

    Science.gov (United States)

    Karam, M. A.; Fung, A. K.

    1984-01-01

    A general theory of intensity scattering from small particles of arbitrary shape was developed based on the radiative transfer theory. Upon permitting the particles to orient in accordance with any prescribed distribution, scattering models can be derived. By making an appropriate choice of the particle size, the scattering model may be used to estimate scattering from media such as snow, vegetation and sea ice. For the purpose of illustration only comparisons with measurements from a vegetated medium are shown. The difference in scattering between elliptic and circular shaped leaves is demonstrated. In the low frequency limit, the major factors on backscattering from vegetation are found to be the depth of the vegetation layer and the orientation distribution of the leaves. The shape of the leaf is of secondary importance.

  7. Annealing behavior of a cast Mg-Gd-Y-Zr alloy with necklace fine grains developed under hot deformation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yi [Educational Key Laboratory of Nonferrous Metal Materials Science and Engineering, School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Yang, Xuyue, E-mail: yangxuyue@mail.csu.edu.cn [Educational Key Laboratory of Nonferrous Metal Materials Science and Engineering, School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Nonferrous Metal Oriented Advanced Structural Materials and Manufacturing Cooperative Innovation Center, Central South University, Changsha 410083 (China); Xiao, Zhenyu; Zhang, Duxiu [Educational Key Laboratory of Nonferrous Metal Materials Science and Engineering, School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Wang, Jun [Institute for Frontier Materials, Deakin University, Geelong, VIC 3216 (Australia); Sakai, Taku [UEC Tokyo (The University of Electro-Communications), Chofu, Tokyo 182-8585 (Japan)

    2017-03-14

    The microstructure and texture development of a cast Mg-Gd-Y-Zr alloy during hot deformation and subsequent annealing were investigated by optical microscopy (OM) and electron backscattered diffraction (EBSD) technology. Initial microstructures with partially and fully developed new fine grains (NFGs), separately attended by continuous or interrupted hot forging, were various mixed grain structures composed of NFGs in necklace and retained coarse grains. It is shown that, during annealing, the development of grain size can be divided into three stages: i.e. an incubation of grain growth, a rapid coarsening and a normal grain growth. After a long time annealing of over 10{sup 4} ks at 693 K, the average grain size for samples continuous compressed to ε=1.2 and those interrupted compressed to ε=1.6 were close. Moreover, orientations of such strain-induced fine grains were relatively randomly distributed, leading to a weakened basal texture, while the basal plane of retained coarse grains were perpendicular to the forging direction. Such texture even became weaker during subsequent annealing. The results show that the development of necklace NFGs during hot deformation can be effective for homogeneous grain refinement under subsequent annealing.

  8. Establishment of Grain Farmers' Supply Response Model and Empirical Analysis under Minimum Grain Purchase Price Policy

    OpenAIRE

    Zhang, Shuang

    2012-01-01

    Based on farmers' supply behavior theory and price expectations theory, this paper establishes grain farmers' supply response model of two major grain varieties (early indica rice and mixed wheat) in the major producing areas, to test whether the minimum grain purchase price policy can have price-oriented effect on grain production and supply in the major producing areas. Empirical analysis shows that the minimum purchase price published annually by the government has significant positive imp...

  9. Grain Refinement and Texture Mitigation in Low Boron Containing TiAl-Alloys

    Science.gov (United States)

    Hecht, Ulrike; Witusiewicz, Victor T.

    2017-12-01

    Controlling the grain size and texture of lamellar TiAl-alloys is essential for well-balanced creep and fatigue properties. Excellent refinement and texture mitigation are achieved in aluminum lean alloys by low boron additions of 0.2 at.%. This amount is sufficient to promote in situ formation of ultrafine borides during the last stages of body centered cubic (BCC) solidification. The borides subsequently serve as nucleation sites for hexagonal close packed (HCP) during the BCC-HCP phase transformation. Bridgman solidification experiments with alloy Ti-43Al-8Nb-0.2C-0.2B were performed under a different growth velocity, i.e., cooling rate, to evaluate the HCP grain size distribution and texture. For slow-to-moderate cooling rates, about 65% of HCP grains are randomly oriented, despite the pronounced texture of the parent BCC phase resulting from directional solidification. For high cooling rates, obtained by quenching, texture mitigation is less pronounced. Only 28% of the HCP grains are randomly oriented, the majority being crystallographic variants of the Burgers orientation relationship.

  10. Applications of the rotating orientation XRD method to oriented materials

    International Nuclear Information System (INIS)

    Guo Zhenqi; Li Fei; Jin Li; Bai Yu

    2009-01-01

    The rotating orientation x-ray diffraction (RO-XRD) method, based on conventional XRD instruments by a modification of the sample stage, was introduced to investigate the orientation-related issues of such materials. In this paper, we show its applications including the determination of single crystal orientation, assistance in crystal cutting and evaluation of crystal quality. The interpretation of scanning patterns by RO-XRD on polycrystals with large grains, bulk material with several grains and oriented thin film is also presented. These results will hopefully expand the applications of the RO-XRD method and also benefit the conventional XRD techniques. (fast track communication)

  11. Stress-assisted grain growth in nanocrystalline metals: Grain boundary mediated mechanisms and stabilization through alloying

    International Nuclear Information System (INIS)

    Zhang, Yang; Tucker, Garritt J.; Trelewicz, Jason R.

    2017-01-01

    The mechanisms of stress-assisted grain growth are explored using molecular dynamics simulations of nanoindentation in nanocrystalline Ni and Ni-1 at.% P as a function of grain size and deformation temperature. Grain coalescence is primarily confined to the high stress region beneath the simulated indentation zone in nanocrystalline Ni with a grain size of 3 nm. Grain orientation and atomic displacement vector mapping demonstrates that coalescence transpires through grain rotation and grain boundary migration, which are manifested in the grain interior and grain boundary components of the average microrotation. A doubling of the grain size to 6 nm and addition of 1 at.% P eliminates stress-assisted grain growth in Ni. In the absence of grain coalescence, deformation is accommodated by grain boundary-mediated dislocation plasticity and thermally activated in pure nanocrystalline Ni. By adding solute to the grain boundaries, the temperature-dependent deformation behavior observed in both the lattice and grain boundaries inverts, indicating that the individual processes of dislocation and grain boundary plasticity will exhibit different activity based on boundary chemistry and deformation temperature.

  12. 75 FR 60161 - WTO Dispute Settlement Proceeding Regarding China-Countervailing and Antidumping Duties on Grain...

    Science.gov (United States)

    2010-09-29

    ... Proceeding Regarding China--Countervailing and Antidumping Duties on Grain Oriented Flat-Rolled Electrical... States of grain oriented flat-rolled electrical steel. That request may be found at http://www.wto.org... countervailing and antidumping duties on grain oriented flat-rolled electrical steel (``GOES'') exported from the...

  13. Quantitative time domain analysis of lifetime-based Förster resonant energy transfer measurements with fluorescent proteins: Static random isotropic fluorophore orientation distributions

    DEFF Research Database (Denmark)

    Alexandrov, Yuriy; Nikolic, Dino Solar; Dunsby, Christopher

    2018-01-01

    Förster resonant energy transfer (FRET) measurements are widely used to obtain information about molecular interactions and conformations through the dependence of FRET efficiency on the proximity of donor and acceptor fluorophores. Fluorescence lifetime measurements can provide quantitative...... into new software for fitting donor emission decay profiles. Calculated FRET parameters, including molar population fractions, are compared for the analysis of simulated and experimental FRET data under the assumption of static and dynamic fluorophores and the intermediate regimes between fully dynamic...... analysis of FRET efficiency and interacting population fraction. Many FRET experiments exploit the highly specific labelling of genetically expressed fluorescent proteins, applicable in live cells and organisms. Unfortunately, the typical assumption of fast randomization of fluorophore orientations...

  14. High electron mobility through the edge states in random networks of c-axis oriented wedge-shaped GaN nanowalls grown by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Bhasker, H. P.; Dhar, S.; Sain, A.; Kesaria, Manoj; Shivaprasad, S. M.

    2012-01-01

    Transport and optical properties of random networks of c-axis oriented wedge-shaped GaN nanowalls grown spontaneously on c-plane sapphire substrates through molecular beam epitaxy are investigated. Our study suggests a one dimensional confinement of carriers at the top edges of these connected nanowalls, which results in a blue shift of the band edge luminescence, a reduction of the exciton-phonon coupling, and an enhancement of the exciton binding energy. Not only that, the yellow luminescence in these samples is found to be completely suppressed even at room temperature. All these changes are highly desirable for the enhancement of the luminescence efficiency of the material. More interestingly, the electron mobility through the network is found to be significantly higher than that is typically observed for GaN epitaxial films. This dramatic improvement is attributed to the transport of electrons through the edge states formed at the top edges of the nanowalls.

  15. Performance of inverted polymer solar cells with randomly oriented ZnO nanorods coupled with atomic layer deposited ZnO

    International Nuclear Information System (INIS)

    Zafar, Muhammad; Yun, Ju-Young; Kim, Do-Heyoung

    2017-01-01

    Highlights: • Hydrothermally grown, randomly oriented, and low areal density ZnO nanorods have been successfully adopted as the electron transport layer in inverted organic solar cells. • The addition of atomic layer deposited ZnO on the ZnO nanorods effectively enhance the photovoltaic performances of inverted organic solar cells. • The inverted organic solar cells with 5 nm thick-ALD ZnO showed the highest power conversion efficiency of 3.08%, which is an enhancement of approximately 80% compared to the cells without the ALD ZnO layer (PCE = 1.67%). - Abstract: Nanostructuring of the electron transport layer (ETL) in organic photovoltaic cells (OPV) is of great interest because it increases the surface area of the cell and electron transport. In this work, hydrothermally grown, randomly oriented, and low areal density ZnO nanorods (NRs) have been adopted as the ETL, and the effect of adding atomic layer deposited (ALD) ZnO on the ZnO NRs on the inverted organic solar cell performance has been investigated. The fabricated inverted organic solar cell with 5-nm-thick ALD-ZnO grown on the ZnO NRs showed the highest power conversion efficiency (PCE) of 3.08%, which is an enhancement of 85% from that of the cell without ALD-ZnO (PCE = 1.67%). The ultrathin ALD-ZnO was found to act as a curing layer of the surface defects on the hydrothermally grown ZnO NRs, resulting in an improvement in photovoltaic performance.

  16. Performance of inverted polymer solar cells with randomly oriented ZnO nanorods coupled with atomic layer deposited ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Zafar, Muhammad [School of Chemical Engineering, Chonnam National University, 300 Youngbong-dong, Gwangju 500-757 (Korea, Republic of); Yun, Ju-Young [Center for Vacuum, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Daejeon 305-600 (Korea, Republic of); Kim, Do-Heyoung, E-mail: kdhh@chonnam.ac.kr [School of Chemical Engineering, Chonnam National University, 300 Youngbong-dong, Gwangju 500-757 (Korea, Republic of)

    2017-03-15

    Highlights: • Hydrothermally grown, randomly oriented, and low areal density ZnO nanorods have been successfully adopted as the electron transport layer in inverted organic solar cells. • The addition of atomic layer deposited ZnO on the ZnO nanorods effectively enhance the photovoltaic performances of inverted organic solar cells. • The inverted organic solar cells with 5 nm thick-ALD ZnO showed the highest power conversion efficiency of 3.08%, which is an enhancement of approximately 80% compared to the cells without the ALD ZnO layer (PCE = 1.67%). - Abstract: Nanostructuring of the electron transport layer (ETL) in organic photovoltaic cells (OPV) is of great interest because it increases the surface area of the cell and electron transport. In this work, hydrothermally grown, randomly oriented, and low areal density ZnO nanorods (NRs) have been adopted as the ETL, and the effect of adding atomic layer deposited (ALD) ZnO on the ZnO NRs on the inverted organic solar cell performance has been investigated. The fabricated inverted organic solar cell with 5-nm-thick ALD-ZnO grown on the ZnO NRs showed the highest power conversion efficiency (PCE) of 3.08%, which is an enhancement of 85% from that of the cell without ALD-ZnO (PCE = 1.67%). The ultrathin ALD-ZnO was found to act as a curing layer of the surface defects on the hydrothermally grown ZnO NRs, resulting in an improvement in photovoltaic performance.

  17. A Randomized Controlled Trial of Group Coping-Oriented Therapy vs Supportive Therapy in Schizophrenia: Results of a 2-Year Follow-up.

    Science.gov (United States)

    Schaub, Annette; Mueser, Kim T; von Werder, Thomas; Engel, Rolf; Möller, Hans-Jürgen; Falkai, Peter

    2016-07-01

    Over the past 30 years, illness management programs and cognitive-behavioral therapy for psychosis have gained prominence in the treatment of schizophrenia. However, little is known about the long-term benefits of these types of programs when delivered during inpatient treatment following a symptom exacerbation. To evaluate this question, we conducted a randomized controlled trial comparing the long-term effects of a group-based coping-oriented program (COP) that combined the elements of illness management with cognitive behavioral-therapy for psychosis, with an equally intensive supportive therapy (SUP) program. 196 inpatients with DSM-IV schizophrenia were randomized to COP or SUP, each lasting 12 sessions provided over 6-8 weeks. Outcome measures were collected in the hospital at baseline and post-assessment, and following discharge into the community 1 and 2 years later. We compared the groups on rehospitalizations, symptoms, psychosocial functioning, and knowledge about psychosis. Intent-to-treat analyses indicated that patients in COP learned significantly more information about psychosis, and had greater reductions in overall symptoms and depression/anxiety over the treatment and follow-up period than patients in SUP. Patients in both groups improved significantly in other symptoms and psychosocial functioning. There were no differences between the groups in hospitalization rates, which were low. People with schizophrenia can benefit from short-term COPs delivered during the inpatient phase, with improvements sustaining for 2 years following discharge from the hospital. More research is needed to evaluate the long-term impact of coping-oriented and similar programs provided during inpatient treatment. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. The PULSAR Specialist Care protocol: a stepped-wedge cluster randomized control trial of a training intervention for community mental health teams in recovery-oriented practice.

    Science.gov (United States)

    Shawyer, Frances; Enticott, Joanne C; Brophy, Lisa; Bruxner, Annie; Fossey, Ellie; Inder, Brett; Julian, John; Kakuma, Ritsuko; Weller, Penelope; Wilson-Evered, Elisabeth; Edan, Vrinda; Slade, Mike; Meadows, Graham N

    2017-05-08

    Recovery features strongly in Australian mental health policy; however, evidence is limited for the efficacy of recovery-oriented practice at the service level. This paper describes the Principles Unite Local Services Assisting Recovery (PULSAR) Specialist Care trial protocol for a recovery-oriented practice training intervention delivered to specialist mental health services staff. The primary aim is to evaluate whether adult consumers accessing services where staff have received the intervention report superior recovery outcomes compared to adult consumers accessing services where staff have not yet received the intervention. A qualitative sub-study aims to examine staff and consumer views on implementing recovery-oriented practice. A process evaluation sub-study aims to articulate important explanatory variables affecting the interventions rollout and outcomes. The mixed methods design incorporates a two-step stepped-wedge cluster randomized controlled trial (cRCT) examining cross-sectional data from three phases, and nested qualitative and process evaluation sub-studies. Participating specialist mental health care services in Melbourne, Victoria are divided into 14 clusters with half randomly allocated to receive the staff training in year one and half in year two. Research participants are consumers aged 18-75 years who attended the cluster within a previous three-month period either at baseline, 12 (step 1) or 24 months (step 2). In the two nested sub-studies, participation extends to cluster staff. The primary outcome is the Questionnaire about the Process of Recovery collected from 756 consumers (252 each at baseline, step 1, step 2). Secondary and other outcomes measuring well-being, service satisfaction and health economic impact are collected from a subset of 252 consumers (63 at baseline; 126 at step 1; 63 at step 2) via interviews. Interview-based longitudinal data are also collected 12 months apart from 88 consumers with a psychotic disorder

  19. MOVING: Motivation-Oriented interVention study for the elderly IN Greifswald: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Kleinke, Fabian; Schwaneberg, Thea; Weymar, Franziska; Penndorf, Peter; Ulbricht, Sabina; Lehnert, Kristin; Dörr, Marcus; Hoffmann, Wolfgang; van den Berg, Neeltje

    2018-01-22

    Cardiovascular diseases (CVD) are the leading cause of mortality. In 2014, they were responsible for 38.9% of all causes of death in Germany. One major risk factor for CVD is a lack of physical activity (PA). A health-promoting lifestyle including regular PA and minimizing sitting time (ST) in daily life is a central preventive measure. Previous studies have shown that PA decreases in older age; 2.4-29% of the people aged over 60 years achieve the World Health Organization recommendations. This age group spends on average 9.4 h per day in sedentary activities. To increase PA and decrease ST, a low-threshold intervention, consisting of individualized feedback letters based on objectively measured data of PA and ST, was developed. The research question is: Do individual feedback letters, based on accelerometer data, have a positive effect on PA and ST? MOVING is a two-arm, randomized controlled trial. Inclusion criteria are age ≥ 65 years and the ability to be physically active. Exclusion criteria are the permanent use of a wheelchair and simultaneous participation in another study on PA. At baseline participants who give informed consent will receive general information and recommendations about the positive effects of regular PA and less ST. Participants of both groups will receive an accelerometer device, which records PA and ST over a period of seven consecutive days following by a randomization. Participants in the intervention group will receive automatically generated, individualized feedback letters by mail based on their PA and ST at baseline and at 3-month follow-up. Further follow-up examinations will be carried out at 6 and 12 months. The primary outcome is the increase of PA and the reduction of ST after 6 months in the intervention group compared to the control group. The goal of the study is to examine the effects of a simple feedback intervention on PA and ST in elderly people. We aim to achieve an effect of 20% increase in moderate

  20. Ferroelectric domain continuity over grain boundaries

    DEFF Research Database (Denmark)

    Mantri, Sukriti; Oddershede, Jette; Damjanovic, Dragan

    2017-01-01

    Formation and mobility of domain walls in ferroelectric materials is responsible for many of their electrical and mechanical properties. Domain wall continuity across grain boundaries has been observed since the 1950's and is speculated to affect the grain boundary-domain interactions, thereby...... impacting macroscopic ferroelectric properties in polycrystalline systems. However detailed studies of such correlated domain structures across grain boundaries are limited. In this work, we have developed the mathematical requirements for domain wall plane matching at grain boundaries of any given...... orientation. We have also incorporated the effect of grain boundary ferroelectric polarization charge created when any two domains meet at the grain boundary plane. The probability of domain wall continuity for three specific grain misorientations is studied. Use of this knowledge to optimize processing...

  1. Patient Acceptance of Sexual Orientation and Gender Identity Questions on Intake Forms in Outpatient Clinics: A Pragmatic Randomized Multisite Trial.

    Science.gov (United States)

    Rullo, Jordan E; Foxen, Jilian L; Griffin, Joan M; Geske, Jennifer R; Gonzalez, Cesar A; Faubion, Stephanie S; van Ryn, Michelle

    2018-03-09

    To (1) test whether patient attitudes toward intake forms at three Midwestern outpatient clinics are significantly more negative among those who are asked to complete SOGI questions versus those who are not; and (2) gain an in-depth understanding of patient concerns about SOGI questions. Data were collected between 6/29/2015 and 2/29/2016 from new patients (N = 491) who presented at three outpatient clinics in a large academic medical center. This study was originally a quality improvement project, and later, institutional review board approval was obtained for secondary data analysis. Two-stage mixed-methods study. (1) Experimental: New patients at three sites were randomly assigned to complete either routine intake forms (control) or routine intake forms with SOGI questions (experimental); and (2) qualitative: interviews with patients who responded negatively to SOGI questions. There were no significant differences in patient attitudes between experimental and control groups (p > .05). Of those who received SOGI questions, only 3 percent reported being distressed, upset, or offended by the SOGI questions. Collection of SOGI data as a part of the routine clinical patient intake process is not distressing to 97 percent of patients who are heterosexual, cisgender, and older than 50 years. © Health Research and Educational Trust.

  2. Feeling Thanks and Saying Thanks: A Randomized Controlled Trial Examining If and How Socially Oriented Gratitude Journals Work.

    Science.gov (United States)

    O'Connell, Brenda H; O'Shea, Deirdre; Gallagher, Stephen

    2017-10-01

    This study examined the effect of a reflective interpersonal gratitude journal, a reflective-behavioral interpersonal gratitude journal and an active control journal, on primary qualities of well-being and depression. Participants (n = 192; 67.2% female) completed this 3-month longitudinal randomized controlled design. Participants in the reflective-behavioral condition experienced the greatest improvements in affect balance and reductions in depression at immediate posttest. Both gratitude interventions improved affect balance at 1 month, compared to the control. Changes in affect balance for those in the reflective-behavioral condition were mediated by the rate at which people expressed gratitude in their existing relationships. This effect was moderated by participant's baseline depressive status. Expressing felt gratitude to others appears to be a crucial step in deriving benefits, and these benefits may not be limited to the emotionally healthy. Given the applied popularity of gratitude interventions, understanding not only if but also how they work is essential. © 2017 Wiley Periodicals, Inc.

  3. Multiscale model of short cracks in a random polycrystalline aggregate

    International Nuclear Information System (INIS)

    Simonovski, I.; Cizelj, L.; Petric, Z.

    2006-01-01

    A plane-strain finite element crystal plasticity model of microstructurally small stationary crack emanating at a surface grain in a 316L stainless steel is proposed. The model consisting of 212 randomly shaped, sized and oriented grains is loaded monotonically in uniaxial tension to a maximum load of 1.12Rp0.2 (280MPa). The influence that a random grain structure imposes on a Stage I crack is assessed by calculating the crack tip opening (CTOD) and sliding displacements (CTSD) for single crystal as well as for polycrystal models, considering also different crystallographic orientations. In the single crystal case the CTOD and CTSD may differ by more than one order of magnitude. Near the crack tip slip is activated on all the slip planes whereby only two are active in the rest of the model. The maximum CTOD is directly related to the maximal Schmid factors. For the more complex polycrystal cases it is shown that certain crystallographic orientations result in a cluster of soft grains around the crack-containing grain. In these cases the crack tip can become a part of the localized strain, resulting in a large CTOD value. This effect, resulting from the overall grain orientations and sizes, can have a greater impact on the CTOD than the local grain orientation. On the other hand, when a localized soft response is formed away from the crack, the localized strain does not affect the crack tip directly, resulting in a small CTOD value. The resulting difference in CTOD can be up to a factor of 4, depending upon the crystallographic set. Grains as far as 6 times the value of crack length significantly influence that crack tip parameters. It was also found that a larger crack containing grain tends to increase the CTOD. Finally, smaller than expected drop in the CTOD (12.7%) was obtained as the crack approached the grain boundary. This could be due to the assumption of the unchanged crack direction, only monotonic loading and simplified grain boundary modelling. (author)

  4. Behaviors of Deformation, Recrystallization and Textures Evolution of Columnar Grains in 3%Si Electrical Steel Slabs

    Directory of Open Access Journals (Sweden)

    SHAO Yuan-yuan

    2017-11-01

    Full Text Available The behaviors of deformation and recrystallization and textures evolution of 3% (mass fraction Si columnar-grained electrical steel slabs were investigated by electron backscatter diffractometer technique and X-ray diffraction. The results indicate that the three columnar-grained samples have different initial textures with the long axes arranged along rolling, transverse and normal directions. Three shear orientations can be obtained in surface layer after hot rolling, of which Goss orientation is formed easily. The α and γ fibre rolling orientations are obtained in RD sample, while strong γ fibre orientations in TD sample and sharp {100} orientations in ND sample are developed respectively. In addition, cube orientation can be found in all the three samples. The characteristics of hot rolled orientations in center region reveal distinct dependence on initial columnar-grained orientations. Strong {111}〈112〉 orientation in RD and TD samples separately comes from Goss orientation of hot rolled sheets, and sharp rotated cube orientation in ND sample originates from the initial {100} orientation of hot rolled sheets after cold rolling. Influenced by initial deviated orientations and coarse grain size, large orientation gradient of rotated cube oriented grain can be observed in ND sample. The coarse {100} orientated grains of center region in the annealed sheets show the heredity of the initial columnar-grained orientations.

  5. Mobile Augmented Reality as a Feature for Self-Oriented, Blended Learning in Medicine: Randomized Controlled Trial

    Science.gov (United States)

    2017-01-01

    Background Advantages of mobile Augmented Reality (mAR) application-based learning versus textbook-based learning were already shown in a previous study. However, it was unclear whether the augmented reality (AR) component was responsible for the success of the self-developed app or whether this was attributable to the novelty of using mobile technology for learning. Objective The study’s aim was to test the hypothesis whether there is no difference in learning success between learners who employed the mobile AR component and those who learned without it to determine possible effects of mAR. Also, we were interested in potential emotional effects of using this technology. Methods Forty-four medical students (male: 25, female: 19, mean age: 22.25 years, standard deviation [SD]: 3.33 years) participated in this study. Baseline emotional status was evaluated using the Profile of Mood States (POMS) questionnaire. Dermatological knowledge was ascertained using a single choice (SC) test (10 questions). The students were randomly assigned to learn 45 min with either a mobile learning method with mAR (group A) or without AR (group B). Afterwards, both groups were again asked to complete the previous questionnaires. AttrakDiff 2 questionnaires were used to evaluate the perceived usability as well as pragmatic and hedonic qualities. For capturing longer term effects, after 14 days, all participants were again asked to complete the SC questionnaire. All evaluations were anonymous, and descriptive statistics were calculated. For hypothesis testing, an unpaired signed-rank test was applied. Results For the SC tests, there were only minor differences, with both groups gaining knowledge (average improvement group A: 3.59 [SD 1.48]; group B: 3.86 [SD 1.51]). Differences between both groups were statistically insignificant (exact Mann Whitney U, U=173.5; P=.10; r=.247). However, in the follow-up SC test after 14 days, group A had retained more knowledge (average decrease of the

  6. Mobile Augmented Reality as a Feature for Self-Oriented, Blended Learning in Medicine: Randomized Controlled Trial.

    Science.gov (United States)

    Noll, Christoph; von Jan, Ute; Raap, Ulrike; Albrecht, Urs-Vito

    2017-09-14

    Advantages of mobile Augmented Reality (mAR) application-based learning versus textbook-based learning were already shown in a previous study. However, it was unclear whether the augmented reality (AR) component was responsible for the success of the self-developed app or whether this was attributable to the novelty of using mobile technology for learning. The study's aim was to test the hypothesis whether there is no difference in learning success between learners who employed the mobile AR component and those who learned without it to determine possible effects of mAR. Also, we were interested in potential emotional effects of using this technology. Forty-four medical students (male: 25, female: 19, mean age: 22.25 years, standard deviation [SD]: 3.33 years) participated in this study. Baseline emotional status was evaluated using the Profile of Mood States (POMS) questionnaire. Dermatological knowledge was ascertained using a single choice (SC) test (10 questions). The students were randomly assigned to learn 45 min with either a mobile learning method with mAR (group A) or without AR (group B). Afterwards, both groups were again asked to complete the previous questionnaires. AttrakDiff 2 questionnaires were used to evaluate the perceived usability as well as pragmatic and hedonic qualities. For capturing longer term effects, after 14 days, all participants were again asked to complete the SC questionnaire. All evaluations were anonymous, and descriptive statistics were calculated. For hypothesis testing, an unpaired signed-rank test was applied. For the SC tests, there were only minor differences, with both groups gaining knowledge (average improvement group A: 3.59 [SD 1.48]; group B: 3.86 [SD 1.51]). Differences between both groups were statistically insignificant (exact Mann Whitney U, U=173.5; P=.10; r=.247). However, in the follow-up SC test after 14 days, group A had retained more knowledge (average decrease of the number of correct answers group A: 0

  7. Effects of unfermented and fermented whole grain rye crisp breads served as part of a standardized breakfast, on appetite and postprandial glucose and insulin responses: a randomized cross-over trial.

    Directory of Open Access Journals (Sweden)

    Daniel P Johansson

    Full Text Available Whole grain rye products have been shown to increase satiety and elicit lower postprandial insulin response without a corresponding change in glucose response compared with soft refined wheat bread. The underlying mechanisms for these effects have not been fully determined The primary aim of the study was to investigate if whole grain rye crisp bread compared to refined wheat crisp bread, elected beneficial effects on appetite and postprandial insulin response, similarly as for other rye products.In a randomized cross-over trial, 23 healthy volunteers, aged 27-70 years, BMI 18-31.4 kg/m2, were served a standardized breakfast with unfermented whole grain rye crisp bread (uRCB, fermented whole grain rye crisp bread (RCB or refined wheat crisp bread (WCB, Appetite was measured using a visual analogue scale (VAS until 4 h after breakfast. Postprandial glucose and insulin were measured at 0-230 min. Breads were chemically characterized including macronutrients, energy, dietary fiber components, and amino acid composition, and microstructure was characterized with light microscopy.Reported fullness was 16% higher (P<0.001, and hunger 11% and 12% lower (P<0.05 after ingestion of uRCB and RCB, respectively, compared with WCB. Postprandial glucose response did not differ significantly between treatments. Postprandial insulin was 10% lower (P<0.007 between 0-120 min but not significantly lower between 0-230 min for RCB compared with WCB. uRCB induced 13% (P<0.002 and 17% (P<0.001 lower postprandial insulin response between 0-230 min compared with RCB and WCB respectively.Whole grain rye crisp bread induces higher satiety and lower insulin response compared with refined wheat crisp bread. Microstructural characteristics, dietary fiber content and composition are probable contributors to the increased satiety after ingestion of rye crisp breads. Higher insulin secretion after ingestion of RCB and WCB compared with uRCB may be due to differences in fiber

  8. Impairment-oriented training or Bobath therapy for severe arm paresis after stroke: a single-blind, multicentre randomized controlled trial.

    Science.gov (United States)

    Platz, T; Eickhof, C; van Kaick, S; Engel, U; Pinkowski, C; Kalok, S; Pause, M

    2005-10-01

    To study the effects of augmented exercise therapy time for arm rehabilitation as either Bobath therapy or the impairment-oriented training (Arm BASIS training) in stroke patients with arm severe paresis. Single blind, multicentre randomized control trial. Three inpatient neurorehabilitation centres. Sixty-two anterior circulation ischaemic stroke patients. Random assignment to three group: (A) no augmented exercise therapy time, (B) augmented exercise therapy time as Bobath therapy and (C) augmented exercise therapy time as Arm BASIS training. Fugl-Meyer arm motor score. Secondary measure: Action Research Arm Test (ARA). Ancillary measures: Fugl-Meyer arm sensation and joint motion/pain scores and the Ashworth Scale (elbow flexors). An overall effect of augmented exercise therapy time on Fugl-Meyer scores after four weeks was not corroborated (mean and 95% confidence interval (CI) of change scores: no augmented exercise therapy time (n=20) 8.8, 5.2-12.3; augmented exercise therapy time (n=40) 9.9, 6.8-13.9; p = 0.2657). The group who received the augmented exercise therapy time as Arm BASIS training (n=20) had, however, higher gains than the group receiving the augmented exercise therapy time as Bobath therapy (n=20) (mean and 95% CI of change scores: Bobath 7.2, 2.6-11.8; BASIS 12.6, 8.4-16.8; p = 0.0432). Passive joint motion/pain deteriorated less in the group who received BASIS training (mean and 95% CI of change scores: Bobath -3.2, -5.2 to -1.1; BASIS 0.1, -1.8-2.0; p = 0.0090). ARA, Fugl-Meyer arm sensation, and Ashworth Scale scores were not differentially affected. The augmented exercise therapy time as Arm BASIS training enhanced selective motor control. Type of training was more relevant for recovery of motor control than therapeutic time spent.

  9. Cognitively oriented behavioral rehabilitation in combination with Qigong for patients on long-term sick leave because of burnout: REST--a randomized clinical trial.

    Science.gov (United States)

    Stenlund, Therese; Ahlgren, Christina; Lindahl, Bernt; Burell, Gunilla; Steinholtz, Katarina; Edlund, Curt; Nilsson, Leif; Knutsson, Anders; Birgander, Lisbeth Slunga

    2009-01-01

    Despite an increase in the occurrence of burnout, there is no agreement on what kind of rehabilitation these patients should be offered. Primary aim of this study was to evaluate effects on psychological variables and sick leave rates by two different group rehabilitation programs for patients on long-term sick leave because of burnout. Rehabilitation program A (Cognitively oriented Behavioral Rehabilitation (CBR) and Qigong) was compared with rehabilitation program B (Qigong only). In a randomized clinical trial, 96 women and 40 men with a mean age of 41.6 +/- 7.4 years were allocated to one of the two rehabilitation programs. A per-protocol analysis showed no significant difference in treatment efficacy between the groups. Both groups improved significantly over time with reduced levels of burnout, self-rated stress behavior, fatigue, depression, anxiety, obsessive-compulsive symptoms, and sick leave rates. In an intention-to-treat analysis, patients in program A had fewer obsessive-compulsive symptoms and larger effect sizes in self-rated stress behavior and obsessive-compulsive symptoms compared to patients in program B. This study showed no differences in effect between CBR and Qigong compared with Qigong only in a per-protocol analysis. Both rehabilitation programs showed positive effect for patients with burnout.

  10. Branching-induced grain boundary evolution during directional solidification of columnar dendritic grains

    International Nuclear Information System (INIS)

    Guo, Chunwen; Li, Junjie; Yu, Honglei; Wang, Zhijun; Lin, Xin; Wang, Jincheng

    2017-01-01

    We present an investigation of secondary and tertiary branching behavior in diverging grain boundaries (GBs) between two columnar dendritic grains with different crystallographic orientations, both by two-dimensional phase-field simulations and thin-sample experiments. The stochasticity of the GB trajectories and the statistically averaged GB orientations were analyzed in detail. The side-branching dynamics and subsequent branch competition behaviors found in the simulations agreed well with the experimental results. When the orientations of two grains are given, the experimental results indicated that the average GB orientation was independent of the pulling velocity in the dendritic growth regime. The simulation and experimental results, as well as the results reported in the literature exhibit a uniform relation between the percentage of the whole gap region occupied by the favorably oriented grain and the difference in the absolute values of the secondary arm growth directions of the two competitive grains. By describing such a uniform relation with a simple fitting equation, we proposed a simple analytical model for the GB orientation at diverging GBs, which gives a more accurate description of GB orientation selection than the existing models.

  11. Grain Boundary Engineering of Electrodeposited Thin Films

    DEFF Research Database (Denmark)

    Alimadadi, Hossein

    is not yet well-understood. This, at least partly, owes to the lack of robust characterization methods for analyzing the nature of grain boundaries including the grain boundary plane characteristics, until recently. In the past decade, significant improvements in the 2-dimensional and 3-dimensional analysis...... of the favorable boundaries that break the network of general grain boundaries. Successful dedicated synthesis of a textured nickel film fulfilling the requirements of grain boundary engineered materials, suggests improved boundary specific properties. However, the textured nickel film shows fairly low...... thermal stability and growth twins annihilate by thermal treatment at 600 degree C. In contrast, for oriented grains, growth nano-twins which are enveloped within columnar grains show a high thermal stability even after thermal treatment at 600 degree C. In order to exploit the high thermal...

  12. Stochastic rocket dynamics under random nozzle side loads: Ornstein-Uhlenbeck boundary layer separation and its coarse grained connection to side loading and rocket response

    Energy Technology Data Exchange (ETDEWEB)

    Keanini, R.G.; Srivastava, N.; Tkacik, P.T. [Department of Mechanical Engineering, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28078 (United States); Weggel, D.C. [Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28078 (United States); Knight, P.D. [Mitchell Aerospace and Engineering, Statesville, North Carolina 28677 (United States)

    2011-06-15

    A long-standing, though ill-understood problem in rocket dynamics, rocket response to random, altitude-dependent nozzle side-loads, is investigated. Side loads arise during low altitude flight due to random, asymmetric, shock-induced separation of in-nozzle boundary layers. In this paper, stochastic evolution of the in-nozzle boundary layer separation line, an essential feature underlying side load generation, is connected to random, altitude-dependent rotational and translational rocket response via a set of simple analytical models. Separation line motion, extant on a fast boundary layer time scale, is modeled as an Ornstein-Uhlenbeck process. Pitch and yaw responses, taking place on a long, rocket dynamics time scale, are shown to likewise evolve as OU processes. Stochastic, altitude-dependent rocket translational motion follows from linear, asymptotic versions of the full nonlinear equations of motion; the model is valid in the practical limit where random pitch, yaw, and roll rates all remain small. Computed altitude-dependent rotational and translational velocity and displacement statistics are compared against those obtained using recently reported high fidelity simulations [Srivastava, Tkacik, and Keanini, J. Appl. Phys. 108, 044911 (2010)]; in every case, reasonable agreement is observed. As an important prelude, evidence indicating the physical consistency of the model introduced in the above article is first presented: it is shown that the study's separation line model allows direct derivation of experimentally observed side load amplitude and direction densities. Finally, it is found that the analytical models proposed in this paper allow straightforward identification of practical approaches for: (i) reducing pitch/yaw response to side loads, and (ii) enhancing pitch/yaw damping once side loads cease. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Arm rehabilitation in post stroke subjects: A randomized controlled trial on the efficacy of myoelectrically driven FES applied in a task-oriented approach.

    Science.gov (United States)

    Jonsdottir, Johanna; Thorsen, Rune; Aprile, Irene; Galeri, Silvia; Spannocchi, Giovanna; Beghi, Ettore; Bianchi, Elisa; Montesano, Angelo; Ferrarin, Maurizio

    2017-01-01

    Motor recovery of persons after stroke may be enhanced by a novel approach where residual muscle activity is facilitated by patient-controlled electrical muscle activation. Myoelectric activity from hemiparetic muscles is then used for continuous control of functional electrical stimulation (MeCFES) of same or synergic muscles to promote restoration of movements during task-oriented therapy (TOT). Use of MeCFES during TOT may help to obtain a larger functional and neurological recovery than otherwise possible. Multicenter randomized controlled trial. Eighty two acute and chronic stroke victims were recruited through the collaborating facilities and after signing an informed consent were randomized to receive either the experimental (MeCFES assisted TOT (M-TOT) or conventional rehabilitation care including TOT (C-TOT). Both groups received 45 minutes of rehabilitation over 25 sessions. Outcomes were Action Research Arm Test (ARAT), Upper Extremity Fugl-Meyer Assessment (FMA-UE) scores and Disability of the Arm Shoulder and Hand questionnaire. Sixty eight subjects completed the protocol (Mean age 66.2, range 36.5-88.7, onset months 12.7, range 0.8-19.1) of which 45 were seen at follow up 5 weeks later. There were significant improvements in both groups on ARAT (median improvement: MeCFES TOT group 3.0; C-TOT group 2.0) and FMA-UE (median improvement: M-TOT 4.5; C-TOT 3.5). Considering subacute subjects (time since stroke rehabilitation (57.9%) than in the C-TOT group (33.2%) (difference in proportion improved 24.7%; 95% CI -4.0; 48.6), though the study did not meet the planned sample size. This is the first large multicentre RCT to compare MeCFES assisted TOT with conventional care TOT for the upper extremity. No adverse events or negative outcomes were encountered, thus we conclude that MeCFES can be a safe adjunct to rehabilitation that could promote recovery of upper limb function in persons after stroke, particularly when applied in the subacute phase.

  14. Effect of a Family-Oriented Communication Skills Training Program on Depression, Anxiety, and Stress in Older Adults: A Randomized Clinical Trial.

    Science.gov (United States)

    Ghazavi, Zahra; Feshangchi, Simin; Alavi, Mousa; Keshvari, Mahrokh

    2016-03-01

    Older adults face several physical and psychological problems such as hearing loss, vision loss, and memory loss, which diminish the quality of their communication. Poor communication in turn affects their psychological wellbeing and induces substantial depression, anxiety, and stress. The family has an important role in the mental health of older adults. This study aimed to investigate the effect of a family-oriented communication skills training program on depression, anxiety, and stress in older adults. For this randomized controlled clinical trial, we enrolled 64 older adults from two healthcare centers affiliated to the Isfahan University of Medical Sciences. The subjects were randomly allocated to an experimental group (n = 32) and a control group (n = 32). In the experimental group, older adults along with their primary caregiver participated in six sessions of communication skill education. The control group participated in two training sessions on nutrition and exercise. All participants answered the DASS21 questionnaire three times-at the start of the study, at the end of the sixth week, and a month after the last educational session of the experimental group. Data were analyzed using chi-square, Fisher's exact and t tests and by repeated measures analysis of variance (ANOVA). In the experimental group, the mean depression score significantly reduced from 10.56 ± 3.34 before intervention to 7.46 ± 2.80 and 6.30 ± 2.75 after intervention and at follow-up, respectively; the mean anxiety score significantly reduced from 8.46 ± 1.88 before intervention to 5.83 ± 1.93 and 5.80 ± 2.12 after intervention and at follow-up, respectively; and the mean stress score significantly decreased from 11.40 ± 4.53 before intervention to 8.90 ± 3.81 and 8.43 ± 3.31 after intervention and at follow-up, respectively (P communication skills could reduce depression, anxiety, and stress in the elderly. Therefore, such programs should be adopted as a non

  15. Polarized Radiative Transfer of a Cirrus Cloud Consisting of Randomly Oriented Hexagonal Ice Crystals: The 3 x 3 Approximation for Non-Spherical Particles

    Science.gov (United States)

    Stamnes, S.; Ou, S. C.; Lin, Z.; Takano, Y.; Tsay, S. C.; Liou, K.N.; Stamnes, K.

    2016-01-01

    The reflection and transmission of polarized light for a cirrus cloud consisting of randomly oriented hexagonal columns were calculated by two very different vector radiative transfer models. The forward peak of the phase function for the ensemble-averaged ice crystals has a value of order 6 x 10(exp 3) so a truncation procedure was used to help produce numerically efficient yet accurate results. One of these models, the Vectorized Line-by-Line Equivalent model (VLBLE), is based on the doubling- adding principle, while the other is based on a vector discrete ordinates method (VDISORT). A comparison shows that the two models provide very close although not entirely identical results, which can be explained by differences in treatment of single scattering and the representation of the scattering phase matrix. The relative differences in the reflected I and Q Stokes parameters are within 0.5 for I and within 1.5 for Q for all viewing angles. In 1971 Hansen showed that for scattering by spherical particles the 3 x 3 approximation is sufficient to produce accurate results for the reflected radiance I and the degree of polarization (DOP), and he conjectured that these results would hold also for non-spherical particles. Simulations were conducted to test Hansen's conjecture for the cirrus cloud particles considered in this study. It was found that the 3 x 3 approximation also gives accurate results for the transmitted light, and for Q and U in addition to I and DOP. For these non-spherical ice particles the 3 x 3 approximation leads to an absolute error 2 x 10(exp -6) for the reflected and transmitted I, Q and U Stokes parameters. Hence, it appears to be an excellent approximation, which significantly reduces the computational complexity and burden required for multiple scattering calculations.

  16. Nuclear magnetic relaxation induced by exchange-mediated orientational randomization: longitudinal relaxation dispersion for a dipole-coupled spin-1/2 pair.

    Science.gov (United States)

    Chang, Zhiwei; Halle, Bertil

    2013-10-14

    In complex biological or colloidal samples, magnetic relaxation dispersion (MRD) experiments using the field-cycling technique can characterize molecular motions on time scales ranging from nanoseconds to microseconds, provided that a rigorous theory of nuclear spin relaxation is available. In gels, cross-linked proteins, and biological tissues, where an immobilized macromolecular component coexists with a mobile solvent phase, nuclear spins residing in solvent (or cosolvent) species relax predominantly via exchange-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings. The physical or chemical exchange processes that dominate the MRD typically occur on a time scale of microseconds or longer, where the conventional perturbation theory of spin relaxation breaks down. There is thus a need for a more general relaxation theory. Such a theory, based on the stochastic Liouville equation (SLE) for the EMOR mechanism, is available for a single quadrupolar spin I = 1. Here, we present the corresponding theory for a dipole-coupled spin-1/2 pair. To our knowledge, this is the first treatment of dipolar MRD outside the motional-narrowing regime. Based on an analytical solution of the spatial part of the SLE, we show how the integral longitudinal relaxation rate can be computed efficiently. Both like and unlike spins, with selective or non-selective excitation, are treated. For the experimentally important dilute regime, where only a small fraction of the spin pairs are immobilized, we obtain simple analytical expressions for the auto-relaxation and cross-relaxation rates which generalize the well-known Solomon equations. These generalized results will be useful in biophysical studies, e.g., of intermittent protein dynamics. In addition, they represent a first step towards a rigorous theory of water (1)H relaxation in biological tissues, which is a prerequisite for unravelling the molecular basis of soft

  17. Statistics of grain misorientations in molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Rybin, V V; Titovets, Yu F; Teplitskij, D M; Zolotorevskij, N Yu

    1982-03-01

    Sets of misorientations between neighbouring grains for three recrystallized molybdenum polycrystals differing in purity, phase composition and prehistory are experimentally determined. The data obtained are analyzed according to modern representations of intergrain boundary structure. In the two materials among the three mentioned above the share of boundaries close to special boundaries with high density of coinciding points turned to be 1.5 times higher than in the polycrystal with chaotic distribution of grains by orientations.

  18. Grain dissection as a grain size reducing mechanism during ice microdynamics

    Science.gov (United States)

    Steinbach, Florian; Kuiper, Ernst N.; Eichler, Jan; Bons, Paul D.; Drury, Martin R.; Griera, Albert; Pennock, Gill M.; Weikusat, Ilka

    2017-04-01

    Ice sheets are valuable paleo-climate archives, but can lose their integrity by ice flow. An understanding of the microdynamic mechanisms controlling the flow of ice is essential when assessing climatic and environmental developments related to ice sheets and glaciers. For instance, the development of a consistent mechanistic grain size law would support larger scale ice flow models. Recent research made significant progress in numerically modelling deformation and recrystallisation mechanisms in the polycrystalline ice and ice-air aggregate (Llorens et al., 2016a,b; Steinbach et al., 2016). The numerical setup assumed grain size reduction is achieved by the progressive transformation of subgrain boundaries into new high angle grain boundaries splitting an existing grain. This mechanism is usually termed polygonisation. Analogue experiments suggested, that strain induced grain boundary migration can cause bulges to migrate through the whole of a grain separating one region of the grain from another (Jessell, 1986; Urai, 1987). This mechanism of grain dissection could provide an alternative grain size reducing mechanism, but has not yet been observed during ice microdynamics. In this contribution, we present results using an updated numerical approach allowing for grain dissection. The approach is based on coupling the full field theory crystal visco-plasticity code (VPFFT) of Lebensohn (2001) to the multi-process modelling platform Elle (Bons et al., 2008). VPFFT predicts the mechanical fields resulting from short strain increments, dynamic recrystallisation process are implemented in Elle. The novel approach includes improvements to allow for grain dissection, which was topologically impossible during earlier simulations. The simulations are supported by microstructural observations from NEEM (North Greenland Eemian Ice Drilling) ice core. Mappings of c-axis orientations using the automatic fabric analyser and full crystallographic orientations using electron

  19. DEVELOPMENT OF GRAIN MARKET IN UKRAINE

    Directory of Open Access Journals (Sweden)

    Aleksandr Maslak

    2015-11-01

    Full Text Available The subject of the research is a set of theoretical, methodological and practical fundamentals of organizational and economic functioning are integrated agricultural formations in the grain market of Ukraine. The methodological basis of research is the complex analysis of economic processes in the grain market in Ukraine and the world. During research we used such methods as method of systematization and comparison, statistic, economic, balance, constructive, target-oriented, and the methods of induction and deduction, analogy and comparison. Main aim of this article is the analysis of the situation on the grain market in Ukraine, defining the role of integrated agricultural formations in this market, improving the organizational-economic mechanism of its functioning, identifies ways of improving the competitiveness of Ukraine among world exporters of grain. Using results of the studies we examined trends grain market in Ukraine; influence of businesses in grain production; analysis of constraints to improve production efficiency of grain; defined domestic (internal needs of grain in Ukraine; assessed the status and expediency transformation infrastructure of the grain market of Ukraine; defined priority directions of development of the grain market in Ukraine. As a result of the preparation of articles, it is obtained the following conclusions: Ukraine is the world's largest producers and exporters of grain, the production of integrated agricultural units to a third of the total grain; technical condition of farm does not meet the needs of production; the domestic market is unable to provide the existing demand for grain production, contributing to export growth; Ukraine has a number of problems due to increased grain production, namely the shortage of storage capacity for the storage of grain, limited performance transshipment of grain in port elevators and imperfection and depreciation of transport systems; solving the existing problems is

  20. Rapid heating effects on grain-size, texture and magnetic properties ...

    Indian Academy of Sciences (India)

    Administrator

    oriented electrical steels (Kumar et ... through changes in recovery and recrystallization beha- viour during the final annealing treatment (Duan et .... recovery, recrystallization and grain coarsening (Doherty et al 1988). The size of recrystallized grain is ...

  1. Grain Handling and Storage.

    Science.gov (United States)

    Harris, Troy G.; Minor, John

    This text for a secondary- or postecondary-level course in grain handling and storage contains ten chapters. Chapter titles are (1) Introduction to Grain Handling and Storage, (2) Elevator Safety, (3) Grain Grading and Seed Identification, (4) Moisture Control, (5) Insect and Rodent Control, (6) Grain Inventory Control, (7) Elevator Maintenance,…

  2. Grain Grading and Handling.

    Science.gov (United States)

    Rendleman, Matt; Legacy, James

    This publication provides an introduction to grain grading and handling for adult students in vocational and technical education programs. Organized in five chapters, the booklet provides a brief overview of the jobs performed at a grain elevator and of the techniques used to grade grain. The first chapter introduces the grain industry and…

  3. A healthy diet with and without cereal grains and dairy products in patients with type 2 diabetes: study protocol for a random-order cross-over pilot study--Alimentation and Diabetes in Lanzarote--ADILAN.

    Science.gov (United States)

    Fontes-Villalba, Maelán; Jönsson, Tommy; Granfeldt, Yvonne; Frassetto, Lynda A; Sundquist, Jan; Sundquist, Kristina; Carrera-Bastos, Pedro; Fika-Hernándo, María; Picazo, Óscar; Lindeberg, Staffan

    2014-01-02

    Research on the role of nutrition in type 2 diabetes has largely focused on macro/micronutrient composition and dietary fiber intake, while fewer studies have tested the effects of differing food choice. Some observational studies and short-term intervention studies suggest that a food pattern mimicking the diet with which humans evolved positively influences glucose control and associated endocrine systems. Such a food pattern mainly differs from other common healthy food patterns in its absence of cereal grains and dairy products. The primary aim of this pilot study is to determine the effect of two healthy diets with or without cereal grains and dairy products on glucose control, while keeping participants' weight stable and other food parameters, such as macro/micronutrient composition, dietary fiber and glycemic load, the same in both diets. We intend to include 15 adult patients with a medical diagnosis of type 2 diabetes mellitus with or without medication and with an increased waist circumference (≥ 80 cm for women and ≥ 94 cm for men) in a random-order cross-over diet intervention study during two periods of four-weeks separated by a six-week washout period. Patients will be instructed to eat two healthy diets according to official dietary guidelines with respect to macro/micronutrient composition and fiber content, but differing in the type of food included, with one diet being without cereal grains and dairy products. Lunch will be served in a hospital kitchen for control of nutrient intake, while the rest of the meals will be eaten at home according to specific directions. The energy content of the diets will be individually adjusted to maintain a stable body weight during the two four-week intervention periods. Primary outcomes will be change in fasting plasma glucagon and fructosamine, while secondary outcomes include change in fasting glucose and glycated hemoglobin, glucose and glucagon response during oral glucose tolerance test, blood

  4. A healthy diet with and without cereal grains and dairy products in patients with type 2 diabetes: study protocol for a random-order cross-over pilot study - Alimentation and Diabetes in Lanzarote -ADILAN

    Science.gov (United States)

    2014-01-01

    Background Research on the role of nutrition in type 2 diabetes has largely focused on macro/micronutrient composition and dietary fiber intake, while fewer studies have tested the effects of differing food choice. Some observational studies and short-term intervention studies suggest that a food pattern mimicking the diet with which humans evolved positively influences glucose control and associated endocrine systems. Such a food pattern mainly differs from other common healthy food patterns in its absence of cereal grains and dairy products. The primary aim of this pilot study is to determine the effect of two healthy diets with or without cereal grains and dairy products on glucose control, while keeping participants’ weight stable and other food parameters, such as macro/micronutrient composition, dietary fiber and glycemic load, the same in both diets. Methods/Design We intend to include 15 adult patients with a medical diagnosis of type 2 diabetes mellitus with or without medication and with an increased waist circumference (≥ 80 cm for women and ≥ 94 cm for men) in a random-order cross-over diet intervention study during two periods of four-weeks separated by a six-week washout period. Patients will be instructed to eat two healthy diets according to official dietary guidelines with respect to macro/micronutrient composition and fiber content, but differing in the type of food included, with one diet being without cereal grains and dairy products. Lunch will be served in a hospital kitchen for control of nutrient intake, while the rest of the meals will be eaten at home according to specific directions. The energy content of the diets will be individually adjusted to maintain a stable body weight during the two four-week intervention periods. Primary outcomes will be change in fasting plasma glucagon and fructosamine, while secondary outcomes include change in fasting glucose and glycated hemoglobin, glucose and glucagon response during oral

  5. Dynamics of interplanetary dust grains

    International Nuclear Information System (INIS)

    Lamy, P.L.

    1975-01-01

    The interaction of spherical grains of various materials-three silicates (quartz, obsidian and andesite), water-ice and iron - whose radii lie in the micronic and submicronic range with the interplanetary medium is solved. This includes: the interaction with the solar radiation field which is solved using Mie scattering theory and taking into account the precise dependence of the optical properties of the five materials upon wavelength; the interaction with the solar wind: corpuscular tangential drag is found to be always important and may even be larger than the Poynting-Robertson drag; the interaction with the interplanetary magnetic field is investigated in terms of a diffusion or random walk through a series of electromagnetic scatterings, leading to a Chapman-Komolgorov equation (i.e., a generalized Liouville equation). Numerical results are presented for these interactions spanning the entire solar system with circularity of elliptical orbits, direct or retrograde, with grains of various materials and sizes and giving -probably for the first time - a clear global picture of the interaction of dust grains with the interplanetary medium. The dynamics of the grains is then investigated using the theory of general perturbations and the numerical integration of trajectories of circum-solar grains

  6. Fabrication of crystal-oriented barium-bismuth titanate ceramics in high magnetic field and subsequent reaction sintering

    International Nuclear Information System (INIS)

    Tanaka, Satoshi; Tomita, Yusuke; Furushima, Ryoichi; Uematsu, Keizo; Shimizu, Hiroyuki; Doshida, Yutaka

    2009-01-01

    High magnetic field was applied to fabricate novel lead-free piezoelectric ceramics with a textured structure. A compact of crystallographically oriented grains was prepared by dry forming in a high magnetic field from a mixed slurry of bismuth titanate and barium titanate powders. Bismuth titanate particles with a size of about 1 μ m were used as the host material. In the forming process, the slurry was poured into a mold and set in a magnetic field of 10 T until completely dried. Bismuth titanate particles were highly oriented in the slurry under the magnetic field. The dried powder compact consisted of highly oriented bismuth titanate particles and randomly oriented barium titanate particles. Barium bismuth titanate ceramics with a- and b-axis orientations were successfully produced from the dried compact by sintering at temperatures above 1100 deg. C.

  7. The PULSAR primary care protocol: a stepped-wedge cluster randomized controlled trial to test a training intervention for general practitioners in recovery-oriented practice to optimize personal recovery in adult patients.

    Science.gov (United States)

    Enticott, Joanne C; Shawyer, Frances; Brophy, Lisa; Russell, Grant; Fossey, Ellie; Inder, Brett; Mazza, Danielle; Vasi, Shiva; Weller, Penelope June; Wilson-Evered, Elisabeth; Edan, Vrinda; Meadows, Graham

    2016-12-20

    General practitioners (GPs) in Australia play a central role in the delivery of mental health care. This article describes the PULSAR (Principles Unite Local Services Assisting Recovery) Primary Care protocol, a novel mixed methods evaluation of a training intervention for GPs in recovery-oriented practice. The aim of the intervention is to optimize personal recovery in patients consulting study GPs for mental health issues. The intervention mixed methods design involves a stepped-wedge cluster randomized controlled trial testing the outcomes of training in recovery-oriented practice, together with an embedded qualitative study to identify the contextual enablers and challenges to implementing recovery-oriented practice. The project is conducted in Victoria, Australia between 2013 and 2017. Eighteen general practices and community health centers are randomly allocated to one of two steps (nine months apart) to start an intervention comprising GP training in the delivery of recovery-oriented practice. Data collection consists of cross-sectional surveys collected from patients of participating GPs at baseline, and again at the end of Steps 1 and 2. The primary outcome is improvement in personal recovery using responses to the Questionnaire about the Process of Recovery. Secondary outcomes are improvements in patient-rated measures of personal recovery and wellbeing, and of the recovery-oriented practice they have received, using the INSPIRE questionnaire, the Warwick-Edinburgh Mental Well-being Scale, and the Kessler Psychological Distress Scale. Participant data will be analyzed in the group that the cluster was assigned to at each study time point. Another per-protocol dataset will contain all data time-stamped according to the date of intervention received at each cluster site. Qualitative interviews with GPs and patients at three and nine months post-training will investigate experiences and challenges related to implementing recovery-oriented practice in primary

  8. Thickness effect on the structure, grain size, and local piezoresponse of self-polarized lead lanthanum zirconate titanate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Melo, M.; Araújo, E. B., E-mail: eudes@dfq.feis.unesp.br [Departamento de Física e Química, Faculdade de Engenharia de Ilha Solteira, UNESP—Univ. Estadual Paulista, 15385-000 Ilha Solteira, SP (Brazil); Shvartsman, V. V. [Institute for Materials Science, University Duisburg-Essen, 45141 Essen (Germany); Shur, V. Ya. [Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation); Kholkin, A. L. [Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation); Department of Physics and CICECO—Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro (Portugal)

    2016-08-07

    Polycrystalline lanthanum lead zirconate titanate (PLZT) thin films were deposited on Pt/TiO{sub 2}/SiO{sub 2}/Si substrates to study the effects of the thickness and grain size on their structural and piezoresponse properties at nanoscale. Thinner PLZT films show a slight (100)-orientation tendency that tends to random orientation for the thicker film, while microstrain and crystallite size increases almost linearly with increasing thickness. Piezoresponse force microscopy and autocorrelation function technique were used to demonstrate the existence of local self-polarization effect and to study the thickness dependence of correlation length. The obtained results ruled out the bulk mechanisms and suggest that Schottky barriers near the film-substrate are likely responsible for a build-in electric field in the films. Larger correlation length evidence that this build-in field increases the number of coexisting polarization directions in larger grains leading to an alignment of macrodomains in thinner films.

  9. Microstructure, texture and magnetic properties of strip-cast 1.3% Si non-oriented electrical steels

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yuanxiang, E-mail: yunboxu@126.com [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang (China); Xu Yunbo; Liu Haitao; Li Chenggang; Cao Guangming; Liu Zhenyu; Wang Guodong [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang (China)

    2012-10-15

    In this work, the evolution of microstructure, texture and magnetic properties of non-oriented 1.3% silicon steel processed using the twin-roll strip casting was investigated, especially under different solidification structures. A number of microstructures about the as-cast strips show that the initial solidification structure of casting a strip can be controlled by the melt superheats. The microstructures with the average grain size of {approx}100-400 {mu}m can be obtained in strips when the melt superheats are from 20 to 60 Degree-Sign C. A nearly random, diffuse, homogeneous texture under a low melt superheat, but comparatively developed {l_brace}100{r_brace} oriented grains are formed under a high melt superheat through the cast strip thickness. The relatively low core loss and high magnetic induction can be obtained in the cold rolled and annealed sheets when increasing the initial grain size of cast-strip. The textures in annealed sheets with coarse initial grain size are characterized by the relatively strong Goss component and {l_brace}001{r_brace} fiber but weak {gamma}-fiber component, which lead to the high permeability. - Highlights: Black-Right-Pointing-Pointer The superheat has an evident effect on the grain size and orientation of strip. Black-Right-Pointing-Pointer Developed Cube and Goss textures were formed in the annealed sheet. Black-Right-Pointing-Pointer High magnetic properties were obtained in the twin-rolled strip casting process.

  10. Deformation inhomogeneity in large-grained AA5754 sheets

    International Nuclear Information System (INIS)

    Zhu Guozhen; Hu Xiaohua; Kang Jidong; Mishra, Raja K.; Wilkinson, David S.

    2011-01-01

    Research highlights: → Microstructure and strain relationship at individual grain level was studied. → 'Hot spots' nucleate early and most keep growing throughout deformation stages. → 'Hot spots' are correlated with 'soft' grains and soft-evolution grains. → Grains with high Schmid factors tend to be 'soft' grains. → Grains with the direction close to tensile axis tend to become softer. - Abstract: Models for deformation and strain localization in polycrystals that incorporate microstructural features including particles are computationally intensive due to the large variation in scale in going from particles to grains to a specimen. As a result such models are generally 2-D in nature. This is an issue for experimental validation. We have therefore studied deformation heterogeneities and strain localization behavior of coarse-grained alloys with only two grains across the sample thickness, therefore mimicking 2-D behavior. Aluminum alloy sheets (AA5754) have been investigated by a number of surface techniques, including digital image correlation, slip trace analysis and electron backscattered diffraction, at the individual grain level. Local strain concentration zones appear from the very beginning of deformation, which then maintain sustained growth and lead, in one of these regions, to localization and final fracture. These 'hot spots' occur in areas with locally soft grains (i.e. grains with or close to the tensile direction) and soft-evolution orientations (i.e. grains with close to the tensile direction). These grains can be correlated with Taylor and/or Schmid factors.

  11. Simulation of grain boundary effects on electronic transport in metals, and detailed causes of scattering

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, Baruch [Process Technology Modeling, Design and Technology Solutions, Technology and Manufacturing Group, Intel Corporation, Santa Clara, CA 95052 (United States); Department of Physics, University of Washington, Seattle, WA 98195 (United States); Park, Seongjun; Haverty, Michael; Shankar, Sadasivan [Process Technology Modeling, Design and Technology Solutions, Technology and Manufacturing Group, Intel Corporation, Santa Clara, CA 95052 (United States); Dunham, Scott T. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Department of Electrical Engineering, University of Washington, Seattle, WA 98195 (United States)

    2010-07-15

    We present first-principles simulations of single grain boundary reflectivity of electrons in noble metals, Cu and Ag. We examine twin and non-twin grain boundaries using non-equilibrium Green's function and first principles methods. We also investigate the determinants of reflectivity in grain boundaries by modeling atomic vacancies, disorder, and orientation and find that both the change in grain orientation and disorder in the boundary itself contribute significantly to reflectivity. We find that grain boundary reflectivity may vary widely depending on the grain boundary structure, consistent with published experimental results. Finally, we examine the reflectivity from multiple grain boundaries and find that grain boundary reflectivity may depend on neighboring grain boundaries. This study raises some potential limitations in the independent grain boundary assumptions of the Mayadas-Shatzkes (MS) model. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  12. Towards modeling intergranular stress corrosion cracks on grain size scales

    International Nuclear Information System (INIS)

    Simonovski, Igor; Cizelj, Leon

    2012-01-01

    Highlights: ► Simulating the onset and propagation of intergranular cracking. ► Model based on the as-measured geometry and crystallographic orientations. ► Feasibility, performance of the proposed computational approach demonstrated. - Abstract: Development of advanced models at the grain size scales has so far been mostly limited to simulated geometry structures such as for example 3D Voronoi tessellations. The difficulty came from a lack of non-destructive techniques for measuring the microstructures. In this work a novel grain-size scale approach for modelling intergranular stress corrosion cracking based on as-measured 3D grain structure of a 400 μm stainless steel wire is presented. Grain topologies and crystallographic orientations are obtained using a diffraction contrast tomography, reconstructed within a detailed finite element model and coupled with advanced constitutive models for grains and grain boundaries. The wire is composed of 362 grains and over 1600 grain boundaries. Grain boundary damage initialization and early development is then explored for a number of cases, ranging from isotropic elasticity up to crystal plasticity constitutive laws for the bulk grain material. In all cases the grain boundaries are modeled using the cohesive zone approach. The feasibility of the approach is explored.

  13. The relevance of grain dissection for grain size reduction in polar ice: insights from numerical models and ice core microstructure analysis

    Science.gov (United States)

    Steinbach, Florian; Kuiper, Ernst-Jan N.; Eichler, Jan; Bons, Paul D.; Drury, Martyn R.; Griera, Albert; Pennock, Gill M.; Weikusat, Ilka

    2017-09-01

    The flow of ice depends on the properties of the aggregate of individual ice crystals, such as grain size or lattice orientation distributions. Therefore, an understanding of the processes controlling ice micro-dynamics is needed to ultimately develop a physically based macroscopic ice flow law. We investigated the relevance of the process of grain dissection as a grain-size-modifying process in natural ice. For that purpose, we performed numerical multi-process microstructure modelling and analysed microstructure and crystallographic orientation maps from natural deep ice-core samples from the North Greenland Eemian Ice Drilling (NEEM) project. Full crystallographic orientations measured by electron backscatter diffraction (EBSD) have been used together with c-axis orientations using an optical technique (Fabric Analyser). Grain dissection is a feature of strain-induced grain boundary migration. During grain dissection, grain boundaries bulge into a neighbouring grain in an area of high dislocation energy and merge with the opposite grain boundary. This splits the high dislocation-energy grain into two parts, effectively decreasing the local grain size. Currently, grain size reduction in ice is thought to be achieved by either the progressive transformation from dislocation walls into new high-angle grain boundaries, called subgrain rotation or polygonisation, or bulging nucleation that is assisted by subgrain rotation. Both our time-resolved numerical modelling and NEEM ice core samples show that grain dissection is a common mechanism during ice deformation and can provide an efficient process to reduce grain sizes and counter-act dynamic grain-growth in addition to polygonisation or bulging nucleation. Thus, our results show that solely strain-induced boundary migration, in absence of subgrain rotation, can reduce grain sizes in polar ice, in particular if strain energy gradients are high. We describe the microstructural characteristics that can be used to

  14. The Relevance of Grain Dissection for Grain Size Reduction in Polar Ice: Insights from Numerical Models and Ice Core Microstructure Analysis

    Directory of Open Access Journals (Sweden)

    Florian Steinbach

    2017-09-01

    Full Text Available The flow of ice depends on the properties of the aggregate of individual ice crystals, such as grain size or lattice orientation distributions. Therefore, an understanding of the processes controlling ice micro-dynamics is needed to ultimately develop a physically based macroscopic ice flow law. We investigated the relevance of the process of grain dissection as a grain-size-modifying process in natural ice. For that purpose, we performed numerical multi-process microstructure modeling and analyzed microstructure and crystallographic orientation maps from natural deep ice-core samples from the North Greenland Eemian Ice Drilling (NEEM project. Full crystallographic orientations measured by electron backscatter diffraction (EBSD have been used together with c-axis orientations using an optical technique (Fabric Analyser. Grain dissection is a feature of strain-induced grain boundary migration. During grain dissection, grain boundaries bulge into a neighboring grain in an area of high dislocation energy and merge with the opposite grain boundary. This splits the high dislocation-energy grain into two parts, effectively decreasing the local grain size. Currently, grain size reduction in ice is thought to be achieved by either the progressive transformation from dislocation walls into new high-angle grain boundaries, called subgrain rotation or polygonisation, or bulging nucleation that is assisted by subgrain rotation. Both our time-resolved numerical modeling and NEEM ice core samples show that grain dissection is a common mechanism during ice deformation and can provide an efficient process to reduce grain sizes and counter-act dynamic grain-growth in addition to polygonisation or bulging nucleation. Thus, our results show that solely strain-induced boundary migration, in absence of subgrain rotation, can reduce grain sizes in polar ice, in particular if strain energy gradients are high. We describe the microstructural characteristics that can be

  15. Large modulation of carrier transport by grain-boundary molecular packing and microstructure in organic thin films

    KAUST Repository

    Rivnay, Jonathan

    2009-11-08

    Solution-processable organic semiconductors are central to developing viable printed electronics, and performance comparable to that of amorphous silicon has been reported for films grown from soluble semiconductors. However, the seemingly desirable formation of large crystalline domains introduces grain boundaries, resulting in substantial device-to-device performance variations. Indeed, for films where the grain-boundary structure is random, a few unfavourable grain boundaries may dominate device performance. Here we isolate the effects of molecular-level structure at grain boundaries by engineering the microstructure of the high-performance n-type perylenediimide semiconductor PDI8-CN 2 and analyse their consequences for charge transport. A combination of advanced X-ray scattering, first-principles computation and transistor characterization applied to PDI8-CN 2 films reveals that grain-boundary orientation modulates carrier mobility by approximately two orders of magnitude. For PDI8-CN 2 we show that the molecular packing motif (that is, herringbone versus slip-stacked) plays a decisive part in grain-boundary-induced transport anisotropy. The results of this study provide important guidelines for designing device-optimized molecular semiconductors. © 2009 Macmillan Publishers Limited. All rights reserved.

  16. A Cellular Automaton / Finite Element model for predicting grain texture development in galvanized coatings

    Science.gov (United States)

    Guillemot, G.; Avettand-Fènoël, M.-N.; Iosta, A.; Foct, J.

    2011-01-01

    Hot-dipping galvanizing process is a widely used and efficient way to protect steel from corrosion. We propose to master the microstructure of zinc grains by investigating the relevant process parameters. In order to improve the texture of this coating, we model grain nucleation and growth processes and simulate the zinc solid phase development. A coupling scheme model has been applied with this aim. This model improves a previous two-dimensional model of the solidification process. It couples a cellular automaton (CA) approach and a finite element (FE) method. CA grid and FE mesh are superimposed on the same domain. The grain development is simulated at the micro-scale based on the CA grid. A nucleation law is defined using a Gaussian probability and a random set of nucleating cells. A crystallographic orientation is defined for each one with a choice of Euler's angle (Ψ,θ,φ). A small growing shape is then associated to each cell in the mushy domain and a dendrite tip kinetics is defined using the model of Kurz [2]. The six directions of basal plane and the two perpendicular directions develop in each mushy cell. During each time step, cell temperature and solid fraction are then determined at micro-scale using the enthalpy conservation relation and variations are reassigned at macro-scale. This coupling scheme model enables to simulate the three-dimensional growing kinetics of the zinc grain in a two-dimensional approach. Grain structure evolutions for various cooling times have been simulated. Final grain structure has been compared to EBSD measurements. We show that the preferentially growth of dendrite arms in the basal plane of zinc grains is correctly predicted. The described coupling scheme model could be applied for simulated other product or manufacturing processes. It constitutes an approach gathering both micro and macro scale models.

  17. Microbiota of kefir grains

    Directory of Open Access Journals (Sweden)

    Tomislav Pogačić

    2013-03-01

    Full Text Available Kefir grains represent the unique microbial community consisting of bacteria, yeasts, and sometimes filamentous moulds creating complex symbiotic community. The complexity of their physical and microbial structures is the reason that the kefir grains are still not unequivocally elucidated. Microbiota of kefir grains has been studied by many microbiological and molecular approaches. The development of metagenomics, based on the identification without cultivation, is opening new possibilities for identification of previously nonisolated and non-identified microbial species from the kefir grains. Considering recent studies, there are over 50 microbial species associated with kefir grains. The aim of this review is to summarise the microbiota composition of kefir grains. Moreover, because of technological and microbiological significance of the kefir grains, the paper provides an insight into the microbiological and molecular methods applied to study microbial biodiversity of kefir grains.

  18. Three dimensional grain boundary modeling in polycrystalline plasticity

    Science.gov (United States)

    Yalçinkaya, Tuncay; Özdemir, Izzet; Fırat, Ali Osman

    2018-05-01

    At grain scale, polycrystalline materials develop heterogeneous plastic deformation fields, localizations and stress concentrations due to variation of grain orientations, geometries and defects. Development of inter-granular stresses due to misorientation are crucial for a range of grain boundary (GB) related failure mechanisms, such as stress corrosion cracking (SCC) and fatigue cracking. Local crystal plasticity finite element modelling of polycrystalline metals at micron scale results in stress jumps at the grain boundaries. Moreover, the concepts such as the transmission of dislocations between grains and strength of the grain boundaries are not included in the modelling. The higher order strain gradient crystal plasticity modelling approaches offer the possibility of defining grain boundary conditions. However, these conditions are mostly not dependent on misorientation of grains and can define only extreme cases. For a proper definition of grain boundary behavior in plasticity, a model for grain boundary behavior should be incorporated into the plasticity framework. In this context, a particular grain boundary model ([l]) is incorporated into a strain gradient crystal plasticity framework ([2]). In a 3-D setting, both bulk and grain boundary models are implemented as user-defined elements in Abaqus. The strain gradient crystal plasticity model works in the bulk elements and considers displacements and plastic slips as degree of freedoms. Interface elements model the plastic slip behavior, yet they do not possess any kind of mechanical cohesive behavior. The physical aspects of grain boundaries and the performance of the model are addressed through numerical examples.

  19. The role of grain size in He bubble formation: Implications for swelling resistance

    Science.gov (United States)

    El-Atwani, O.; Nathaniel, J. E.; Leff, A. C.; Muntifering, B. R.; Baldwin, J. K.; Hattar, K.; Taheri, M. L.

    2017-02-01

    Nanocrystalline metals are postulated as radiation resistant materials due to their high defect and particle (e.g. Helium) sink density. Here, the performance of nanocrystalline iron films is investigated in-situ in a transmission electron microscope (TEM) using He irradiation at 700 K. Automated crystal orientation mapping is used in concert with in-situ TEM to explore the role of grain orientation and grain boundary character on bubble density trends. Bubble density as a function of three key grain size regimes is demonstrated. While the overall trend revealed an increase in bubble density up to a saturation value, grains with areas ranging from 3000 to 7500 nm2 show a scattered distribution. An extrapolated swelling resistance based on bubble size and areal density indicated that grains with sizes less than 2000 nm2 possess the greatest apparent resistance. Moreover, denuded zones are found to be independent of grain size, grain orientation, and grain boundary misorientation angle.

  20. Inter-grain coupling and grain charge in dusty plasma Coulomb crystals

    International Nuclear Information System (INIS)

    Smith, M. A.; Goodrich, J.; Mohideen, U.; Rahman, H. U.; Rosenberg, M.; Mendis, D. A.

    1998-01-01

    We have studied the lattice structure and grain charge of dusty plasma Coulomb crystals formed in rectangular conductive grooves as a function of plasma temperature and density. The crystal appears to be made of mutually repulsive columns of grains confined by the walls of the groove. The columns are oriented along the direction of the electrode sheath electric field. A simple phenomenological model wherein the inter-grain spacing results from an attractive electric field induced dipole-dipole force balanced by a repulsive monopole Coulomb force is consistent with observed features of the Coulomb crystal

  1. A comparison of grain boundary evolution during grain growth in fcc metals

    International Nuclear Information System (INIS)

    Brons, J.G.; Thompson, G.B.

    2013-01-01

    Grain growth of Cu and Ni thin films, subjected to in situ annealing within a transmission electron microscope, has been quantified using a precession-enhanced electron diffraction technique. The orientation of each grain and its misorientation with respect to its neighboring grains were calculated. The Cu underwent grain growth that maintained a monomodal grain size distribution, with its low-angle grain boundaries being consumed, and the Ni exhibited grain size distributions in stages, from monomodal to bimodal to monomodal. The onset of Ni’s abnormal grain growth was accompanied by a sharp increase in the Σ3 and Σ9 boundary fractions, which is attributed to simulation predictions of their increased mobility. These Σ3 and Σ9 fractions then dropped to their room temperature values during the third stage of grain growth. In addition to the Σ3 and Σ9 boundaries, the Σ5 and Σ7 boundaries also underwent an increase in total boundary fraction with increasing temperature in both metals

  2. Pollen Grains, Random Walks and Einstein

    Indian Academy of Sciences (India)

    Gouy showed that the fluctuations became more rapid if the viscosity of the fluid ..... so we see that the root-mean-square displacement is. ~(t) = bv'N = VV2Tt ..... finance, the working of motor proteins in cells, the analysis of DNA sequences,.

  3. Pollen Grains, Random Walks and Einstein

    Indian Academy of Sciences (India)

    real thing. It's easier said than done, but it can be done. An- other way to see it is to point a low-power laser (a .... temperature T would wander, in a time t, a distance3. R(t) ("'oJ v'Di, .... 3.2 How Far does a Brownian Particle Travel? Assume that ...

  4. German Orientalism

    OpenAIRE

    Margaret Olin

    2011-01-01

    Review of: Suzanne L. Marchand, German Orientalism in the Age of Empire: Religion, Race and Scholarship, Cambridge and Washington, D.C.: Cambridge University Press, 2009. This analysis of Suzanne L. Marchand’s German Orientalism in the Age of Empire: Religion, Race and Scholarship reads her contribution in part against the background of Edward Said’s path breaking book Orientalism. Differences lie in her more expansive understanding of the term ‘Oriental’ to include the Far East and her conce...

  5. Effectiveness of the Lunch is in the Bag program on communication between the parent, child and child-care provider around fruits, vegetables and whole grain foods: A group-randomized controlled trial.

    Science.gov (United States)

    Sharma, Shreela V; Rashid, Tasnuva; Ranjit, Nalini; Byrd-Williams, Courtney; Chuang, Ru-Jye; Roberts-Gray, Cynthia; Briley, Margaret; Sweitzer, Sara; Hoelscher, Deanna M

    2015-12-01

    To evaluate the effectiveness of the parent- and early care education (ECE) center-based Lunch is in the Bag program on communication between parent, child, and their ECE center providers around fruits, vegetables and whole grain foods (FVWG). A total of n=30 ECE center; 577 parent-child dyads participated in this group-randomized controlled trial conducted from 2011 to 2013 in Texas (n=15 ECE center, 327 dyads intervention group; n=15 ECE center, 250 dyads comparison group). Parent-child and parent-ECE center provider communication was measured using a parent-reported survey administered at baseline and end of the five-week intervention period. Multilevel linear regression analysis was used to compare the pre-to-post intervention changes in the parent-child and parent-ECE center provider communication scales. Significance was set at pparent-child and parent-ECE center provider communication scores were low. There was a significant increase post-intervention in the parent-ECE center provider communication around vegetables (Adjusted β=0.78, 95%CI: 0.13, 1.43, p=0.002), and around fruit (Adjusted β=0.62, 95%CI: 0.04, 0.20, p=0.04) among the parents in the intervention group as compared to those in the comparison group. There were no significant intervention effects on parent-child communication. Lunch is in the Bag had significant positive effects on improving communication between the parents and ECE center providers around FVWG. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Shock fabrics in fine-grained micrometeorites

    Science.gov (United States)

    Suttle, M. D.; Genge, M. J.; Russell, S. S.

    2017-10-01

    The orientations of dehydration cracks and fracture networks in fine-grained, unmelted micrometeorites were analyzed using rose diagrams and entropy calculations. As cracks exploit pre-existing anisotropies, analysis of their orientation provides a mechanism with which to study the subtle petrofabrics preserved within fine-grained and amorphous materials. Both uniaxial and biaxial fabrics are discovered, often with a relatively wide spread in orientations (40°-60°). Brittle deformation cataclasis and rotated olivine grains are reported from a single micrometeorite. This paper provides the first evidence for impact-induced shock deformation in fine-grained micrometeorites. The presence of pervasive, low-grade shock features in CM chondrites and CM-like dust, anomalously low-density measurements for C-type asteroids, and impact experiments which suggest CM chondrites are highly prone to disruption all imply that CM parent bodies are unlikely to have remained intact and instead exist as a collection of loosely aggregated rubble-pile asteroids, composed of primitive shocked clasts.

  7. Grain distinct stratified nanolayers in aluminium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Donatus, U., E-mail: uyimedonatus@yahoo.com [School of Materials, The University of Manchester, Manchester, M13 9PL, England (United Kingdom); Thompson, G.E.; Zhou, X.; Alias, J. [School of Materials, The University of Manchester, Manchester, M13 9PL, England (United Kingdom); Tsai, I.-L. [Oxford Instruments NanoAnalysis, HP12 2SE, High Wycombe (United Kingdom)

    2017-02-15

    The grains of aluminium alloys have stratified nanolayers which determine their mechanical and chemical responses. In this study, the nanolayers were revealed in the grains of AA6082 (T6 and T7 conditions), AA5083-O and AA2024-T3 alloys by etching the alloys in a solution comprising 20 g Cr{sub 2}O{sub 3} + 30 ml HPO{sub 3} in 1 L H{sub 2}O. Microstructural examination was conducted on selected grains of interest using scanning electron microscopy and electron backscatter diffraction technique. It was observed that the nanolayers are orientation dependent and are parallel to the {100} planes. They have ordered and repeated tunnel squares that are flawed at the sides which are aligned in the <100> directions. These flawed tunnel squares dictate the tunnelling corrosion morphology as well as appearing to have an affect on the arrangement and sizes of the precipitation hardening particles. The inclination of the stratified nanolayers, their interpacing, and the groove sizes have significant influence on the corrosion behaviour and seeming influence on the strengthening mechanism of the investigated aluminium alloys. - Highlights: • Stratified nanolayers in aluminium alloy grains. • Relationship of the stratified nanolayers with grain orientation. • Influence of the inclinations of the stratified nanolayers on corrosion. • Influence of the nanolayers interspacing and groove sizes on hardness and corrosion.

  8. Deformation-induced microstructural evolution at grain scale

    DEFF Research Database (Denmark)

    Winther, Grethe

    During plastic deformation metals develop microstructures which may be analysed on several scales,spanning from crystallographic textures averaged over the entire sample to the scale of individualgrains. Even within individual grains, intragranular phenomena in the form of orientation gradients...... aswell as dislocation patterning by formation of dislocation boundaries occur. Experimental data andassociated data analysis at the grain scale and below will be presented to illustrate our current level ofunderstanding. The basis for the analysis is the crystallographic orientation of the grain as well...... is presented for both fcc and bcc materials inseveral deformation modes, demonstrating a clear grain orientation dependence [Huang & Winther,2007]. This dependence has its origin in a dependence on the slip systems [Winther & Huang, 2007].This further implies that the dislocations in the boundaries come from...

  9. Orienteering injuries

    OpenAIRE

    Folan, Jean M.

    1982-01-01

    At the Irish National Orienteering Championships in 1981 a survey of the injuries occurring over the two days of competition was carried out. Of 285 individual competitors there was a percentage injury rate of 5.26%. The article discusses the injuries and aspects of safety in orienteering.

  10. Elevated temperature mechanical properties of novel ultra-fine grained Cu–Nb composites

    Energy Technology Data Exchange (ETDEWEB)

    Primorac, Mladen-Mateo [Department of Materials Physics, Montanuniversität Leoben (Austria); Abad, Manuel David; Hosemann, Peter [Department of Nuclear Engineering, University of California, Berkeley (United States); Kreuzeder, Marius [Department of Materials Physics, Montanuniversität Leoben (Austria); Maier, Verena [Department of Materials Physics, Montanuniversität Leoben (Austria); Erich-Schmid Institute for Materials Science, Austrian Academy of Sciences, Leoben (Austria); Kiener, Daniel, E-mail: daniel.kiener@unileoben.ac.at [Department of Materials Physics, Montanuniversität Leoben (Austria)

    2015-02-11

    Ultra-fine grained materials exhibit outstanding properties and are therefore favorable for prospective applications. One of these promising systems is the composite assembled by the body centered cubic niobium and the face centered cubic copper. Cu–Nb composites show a high hardness and good thermal stability, as well as a high radiation damage tolerance. These properties make the material interesting for use in nuclear reactors. The aim of this work was to create a polycrystalline ultra-fine grained composite for high temperature applications. The samples were manufactured via a powder metallurgical route using high pressure torsion, exhibiting a randomly distributed oriented grain size between 100 and 200 nm. The mechanical properties and the governing plastic deformation behavior as a function of temperature were determined by high temperature nanoindentation up to 500 °C. It was found that in the lower temperature regions up to 300 °C the plastic deformation is mainly governed by dislocation interactions, such as dislocation glide and the nucleation of kink pairs. For higher temperatures, thermally activated processes at grain boundaries are proposed to be the main mechanism governing plastic deformation. This mechanistic view is supported by temperature dependent changes in hardness, strain rate sensitivity, activation volume, and activation energy.

  11. Grain by grain study of the mechanisms of crack propagation during iodine SCC of Zry-4

    International Nuclear Information System (INIS)

    Haddad Andalag, R.E.

    1993-01-01

    This paper describes the tests conducted to determine the conditions leading to cracking of a specified grain of metal, focussing on the crystallographic orientation of crack paths, the critical stress conditions and the significance of the fractographic features encountered. In order to get orientable cracking, a technique was developed to produce iodine SCC, by means of pressurizing tubes of a specially heat treated Zry-4 having very large grains, shaped as discs of a few millimeters in diameter and grown up to the wall thickness. Careful orientation of fractured grains, performed by means of a back-reflection Laue technique with a precision better than one degree, has proved that transgranular cracking occurs only along basal planes. The effect of anisotropy, plasticity, triaxiality and residual stresses originated in thermal contraction, has to be considered to account for the influence of the stress state . A grain by grain calculation led to the conclusion that transgranular cracking always occurs on those bearing the maximum resolved tensile stress on basal planes. There are clear indications of the need of a triaxial stress state for the process to occur. Fracture modes other than pseudo-cleavage have been encountered, including intergranular separation, ductile tearing produced by prismatic slip and propagation along twin boundaries. In each case the fractographic features have been identified, and associations have been made with fractographs obtained in normal fuel cladding. (Author)

  12. Electromechanical Response of Polycrystalline Barium Titanate Resolved at the Grain Scale

    DEFF Research Database (Denmark)

    Majkut, Marta; Daniels, John E.; Wright, Jonathan P.

    2017-01-01

    critical for understanding bulk polycrystalline ferroic behavior. Here, three-dimensional X-ray diffraction is used to reconstruct a 3D grain map (grain orientations and neighborhoods) of a polycrystalline barium titanate sample and track the grain-scale non-180° ferroelectric domain switching strains...

  13. Determining grain resolved stresses in polycrystalline materials using three-dimensional X-ray diffraction

    DEFF Research Database (Denmark)

    Oddershede, Jette; Schmidt, Søren; Poulsen, Henning Friis

    2010-01-01

    An algorithm is presented for characterization of the grain resolved (type II) stress states in a polycrystalline sample based on monochromatic X-ray diffraction data. The algorithm is a robust 12-parameter-per-grain fit of the centre-of-mass grain positions, orientations and stress tensors...

  14. Investigation of grain competitive growth during directional solidification of single-crystal nickel-based superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xinbao [National Energy R and D Center of Clean and High-Efficiency Fossil-Fired Power Generation Technology, Xi' an Thermal Power Research Institute Co. Ltd., Xi' an (China); Northwestern Polytechnical University, State Key Laboratory of Solidification Processing, Xi' an (China); Liu, Lin; Zhang, Jun [Northwestern Polytechnical University, State Key Laboratory of Solidification Processing, Xi' an (China)

    2015-08-15

    Grain competitive growth of nickel-based single-crystal superalloys during directional solidification was investigated. A detailed characterization of bi-crystals' competitive growth was performed to explore the competitive grain evolution. It was found that high withdrawal rate improved the efficiency of grain competitive growth. The overgrowth rate was increased when the misorientation increased. Four patterns of grain competitive growth with differently oriented dispositions were characterized. The results indicated that the positive branching of the dendrites played a significant role in the competitive growth process. The effect of crystal orientation and heat flow on the competitive growth can be attributed to the blocking mechanism between the adjacent grains. (orig.)

  15. Compaction of cereal grain

    OpenAIRE

    Wychowaniec, J.; Griffiths, I.; Gay, A.; Mughal, A.

    2013-01-01

    We report on simple shaking experiments to measure the compaction of a column of Firth oat grain. Such grains are elongated anisotropic particles with a bimodal polydispersity. In these experiments, the particle configurations start from an initially disordered, low-packing-fraction state and under vertical shaking evolve to a dense state with evidence of nematic-like structure at the surface of the confining tube. This is accompanied by an increase in the packing fraction of the grain.

  16. Evolution of interstellar grains

    International Nuclear Information System (INIS)

    Greenberg, J.M.

    1984-01-01

    The principal aim of this chapter is to derive the properties of interstellar grains as a probe of local physical conditions and as a basis for predicting such properties as related to infrared emissivity and radiative transfer which can affect the evolution of dense clouds. The first sections will develop the criteria for grain models based directly on observations of gas and dust. A summary of the chemical evolution of grains and gas in diffuse and dense clouds follows. (author)

  17. Microbiota of kefir grains

    OpenAIRE

    Tomislav Pogačić; Sanja Šinko; Šimun Zamberlin; Dubravka Samaržija

    2013-01-01

    Kefir grains represent the unique microbial community consisting of bacteria, yeasts, and sometimes filamentous moulds creating complex symbiotic community. The complexity of their physical and microbial structures is the reason that the kefir grains are still not unequivocally elucidated. Microbiota of kefir grains has been studied by many microbiological and molecular approaches. The development of metagenomics, based on the identification without cultivation, is opening new possibilities f...

  18. Whole-grain wheat consumption reduces inflammation in a randomized controlled trial on overweight and obese subjects with unhealthy dietary and lifestyle behaviors: role of polyphenols bound to cereal dietary fiber

    NARCIS (Netherlands)

    Vitaglione, P.; Mennella, I.; Ferracane, R.; Rivellese, A.A.; Giacco, R.; Ercolini, D.; Gibbons, S.M.; Storia, la A.; Gilbert, A.J.; Jonnalagadda, S.; Thielecke, F.; Gallo, M.A.; Scalfi, L.; Fogliano, V.

    2015-01-01

    Background: Epidemiology associates whole-grain (WG) consumption with several health benefits. Mounting evidence suggests that WG wheat polyphenols play a role in mechanisms underlying health benefits. Objective: The objective was to assess circulating concentration, excretion, and the physiologic

  19. Effect of grain refinement by severe plastic deformation on the next-neighbor misorientation distribution

    International Nuclear Information System (INIS)

    Toth, L.S.; Beausir, B.; Gu, C.F.; Estrin, Y.; Scheerbaum, N.; Davies, C.H.J.

    2010-01-01

    Next-neighbor misorientation distributions (NNMD) in severely deformed polycrystalline materials are commonly measured by orientation imaging. A procedure is proposed which enables the separation of NNMD of ultrafine-grained materials into two parts: the distribution of misorientations between newly emerged grains within the original ('parent') grain interior ('internal daughter grains') and the distribution of misorientations between grains adjacent to an original grain boundary on its opposite sides ('grain boundary daughter grains'). The procedure is based on electron backscatter diffraction orientation map analyses carried out on different planes of deformed samples considering the evolution of the grain size and shape during severe plastic deformation. It was applied to copper processed by up to three passes of equal-channel angular pressing. A characteristic feature of the measured NNMD is the occurrence of a double peak, which is clearly due to the differences between the NNMD of the two distinct populations of new grains defined above. The peak at low angles represents mainly the continual grain subdivision process in the interior of a parent grain (and is associated with internal daughter grains), while the peak at large angles is due to the high angle misorientations of the grain boundary daughter grains.

  20. Process parameters, orientation, and functional properties of melt-processed bulk Y-Ba-Cu-O superconductors

    International Nuclear Information System (INIS)

    Zakharchenko, I.V.; Terryll, K.M.; Rao, K.V.; Balachandran, U.

    1995-03-01

    This study compared the microstructure, texturing, and functional properties (critical currents) of YBa 2 Cu 3 O 7-x -based bulk pellets that were prepared by the quench-melt-growth-process (QMGP), melt-textured growth (MTG), and conventional solid-state reaction (SSR) approaches. Using two X-ray diffraction (XRD) methods, θ-2θ, and rocking curves, the authors found that the individual grains of two melt-processed pellets exhibited remarkable preferred orientational alignment (best rocking curve width = 3.2 degree). However, the direction of the preferred orientation among the grains was random. Among the three types of bulk materials studied, the QMGP sample was found to have the best J c values, ∼ 4,500 A/cm 2 at 77 K in a field of 2 kG, as determined from SQUID magnetic data

  1. Origins of GEMS Grains

    Science.gov (United States)

    Messenger, S.; Walker, R. M.

    2012-01-01

    Interplanetary dust particles (IDPs) collected in the Earth s stratosphere contain high abundances of submicrometer amorphous silicates known as GEMS grains. From their birth as condensates in the outflows of oxygen-rich evolved stars, processing in interstellar space, and incorporation into disks around new stars, amorphous silicates predominate in most astrophysical environments. Amorphous silicates were a major building block of our Solar System and are prominent in infrared spectra of comets. Anhydrous interplanetary dust particles (IDPs) thought to derive from comets contain abundant amorphous silicates known as GEMS (glass with embedded metal and sulfides) grains. GEMS grains have been proposed to be isotopically and chemically homogenized interstellar amorphous silicate dust. We evaluated this hypothesis through coordinated chemical and isotopic analyses of GEMS grains in a suite of IDPs to constrain their origins. GEMS grains show order of magnitude variations in Mg, Fe, Ca, and S abundances. GEMS grains do not match the average element abundances inferred for ISM dust containing on average, too little Mg, Fe, and Ca, and too much S. GEMS grains have complementary compositions to the crystalline components in IDPs suggesting that they formed from the same reservoir. We did not observe any unequivocal microstructural or chemical evidence that GEMS grains experienced prolonged exposure to radiation. We identified four GEMS grains having O isotopic compositions that point to origins in red giant branch or asymptotic giant branch stars and supernovae. Based on their O isotopic compositions, we estimate that 1-6% of GEMS grains are surviving circumstellar grains. The remaining 94-99% of GEMS grains have O isotopic compositions that are indistinguishable from terrestrial materials and carbonaceous chondrites. These isotopically solar GEMS grains either formed in the Solar System or were completely homogenized in the interstellar medium (ISM). However, the

  2. Whole-grain wheat consumption reduces inflammation in a randomized controlled trial on overweight and obese subjects with unhealthy dietary and lifestyle behaviors: role of polyphenols bound to cereal dietary fiber.

    Science.gov (United States)

    Vitaglione, Paola; Mennella, Ilario; Ferracane, Rosalia; Rivellese, Angela A; Giacco, Rosalba; Ercolini, Danilo; Gibbons, Sean M; La Storia, Antonietta; Gilbert, Jack A; Jonnalagadda, Satya; Thielecke, Frank; Gallo, Maria A; Scalfi, Luca; Fogliano, Vincenzo

    2015-02-01

    Epidemiology associates whole-grain (WG) consumption with several health benefits. Mounting evidence suggests that WG wheat polyphenols play a role in mechanisms underlying health benefits. The objective was to assess circulating concentration, excretion, and the physiologic role of WG wheat polyphenols in subjects with suboptimal dietary and lifestyle behaviors. A placebo-controlled, parallel-group randomized trial with 80 healthy overweight/obese subjects with low intake of fruit and vegetables and sedentary lifestyle was performed. Participants replaced precise portions of refined wheat (RW) with a fixed amount of selected WG wheat or RW products for 8 wk. At baseline and every 4 wk, blood, urine, feces, and anthropometric and body composition measures were collected. Profiles of phenolic acids in biological samples, plasma markers of metabolic disease and inflammation, and fecal microbiota composition were assessed. WG consumption for 4-8 wk determined a 4-fold increase in serum dihydroferulic acid (DHFA) and a 2-fold increase in fecal ferulic acid (FA) compared with RW consumption (no changes). Similarly, urinary FA at 8 wk doubled the baseline concentration only in WG subjects. Concomitant reduction in plasma tumor necrosis factor-α (TNF-α) after 8 wk and increased interleukin (IL)-10 only after 4 wk with WG compared with RW (P = 0.04) were observed. No significant change in plasma metabolic disease markers over the study period was observed, but a trend toward lower plasma plasminogen activator inhibitor 1 with higher excretion of FA and DHFA in the WG group was found. Fecal FA was associated with baseline low Bifidobacteriales and Bacteroidetes abundances, whereas after WG consumption, it correlated with increased Bacteroidetes and Firmicutes but reduced Clostridium. TNF-α reduction correlated with increased Bacteroides and Lactobacillus. No effect of dietary interventions on anthropometric measurements and body composition was found. WG wheat

  3. Reversal of asymmetry of X-ray peak profiles from individual grains during a strain path change

    DEFF Research Database (Denmark)

    Wejdemann, Christian; Lienert, U.; Pantleon, Wolfgang

    2010-01-01

    X-ray peak profiles are measured from individual bulk grains during tensile deformation. Two differently oriented copper samples pre-deformed in tension show the expected peak profile asymmetry caused by intra-grain stresses. One of the samples is oriented to achieve a significant change of the i......X-ray peak profiles are measured from individual bulk grains during tensile deformation. Two differently oriented copper samples pre-deformed in tension show the expected peak profile asymmetry caused by intra-grain stresses. One of the samples is oriented to achieve a significant change...

  4. Pattern recognition in bees : orientation discrimination

    NARCIS (Netherlands)

    Hateren, J.H. van; Srinivasan, M.V.; Wait, P.B.

    1990-01-01

    Honey bees (Apis mellifera, worker) were trained to discriminate between two random gratings oriented perpendicularly to each other. This task was quickly learned with vertical, horizontal, and oblique gratings. After being trained on perpendicularly-oriented random gratings, bees could discriminate

  5. Grain dynamics and inter-grain coupling in dusty plasma Coulomb crystals

    International Nuclear Information System (INIS)

    Rahman, H.U.; Mohideen, U.; Smith, M.A.; Rosenberg, M.; Mendis, D.A.

    2001-01-01

    We review our results on the lattice structure and the lattice dynamics of dusty plasma Coulomb crystals formed in rectangular conductive grooves. The basic structure appears to be made of mutually repulsive columns of grains confined by the walls of the groove. The columns are oriented along the direction of the electrode sheath electric field. Inter-grain coupling as a function of plasma temperature and density were investigated by measurement of these parameters. A simple phenomenological model wherein the inter-grain spacing along the column results from an attractive electric field induced dipole-dipole force balanced by a repulsive monopole Coulomb force is consistent with observed features of the Coulomb crystal. In addition, here we present some preliminary measurements of the vibration and rotation dynamics of the individual grains in the Coulomb crystal. The thermal energy of the dust grain thus calculated is much less than the inter-grain Coulomb potential energy as required for the formation of stable structures. Also the observed rotational frequency is consistent with the assumption of thermal equilibrium between the dust grains and the neutral gas. (orig.)

  6. Microstructure and orientation of hydrides in zircaloy-4 tubes for CAREM 25 fuel rods

    International Nuclear Information System (INIS)

    Juarez, G; Flores, A; Bianchi, D; Vizcaino, P

    2012-01-01

    The aim of the present work was giving support to the development of Zircaloy-4 fuel claddings for the CAREM 25 reactor through microstructural and mechanical properties studies along the manufacturing process. The manufacturing route was defined in 4 cold rolling stages and two thermal treatments, one at the middle and one after the last rolling stage. The first two rolling stages were performed in FAESA and the last two in PPFAECNEA using the rolling machine HPTR 8-15. The reference values for the evaluation were those indicated in the technical specification CAREM25 F ET-3-B0610. In this context, four tubes were received from FAESA. To these tubes microstructural and hydride orientation studies were performed to characterize the material in each step performed in PPFAE. The material received from FAESA has a grain size of 6 um, which fulfills the specification requirements for the final product (<11.2 um), so that, the final rolling stages (3rd and 4th) refine the grain until 3 um finished in the microstructure. Hydride morphology evolved from a random orientation in the recrystallized material or radial in the stress relieved material to the circumferential orientation requested in the specification. The final thermal treatment did not modify this morphology. The PD. (Marshall parameter) produced a value of 48, indicating that only 4% of the hydrides are oriented between 48 o and 90 o , that is, far from the circumferential direction (author)

  7. Exfoliation of GaAs caused by MeV 1H and 4He ion implantation at left angle 100 right angle , left angle 110 right angle axial and random orientations

    International Nuclear Information System (INIS)

    Rauhala, E.; Raeisaenen, J.

    1994-01-01

    The exfoliation procedure of the ion range determination of gaseous implants in single crystal GaAs is investigated. The correlation of the observed crater depth with the ion range is studied for random, left angle 100 right angle and left angle 110 right angle axial orientation high dose implantations of 1.5-2.5 MeV 1 H and 4 He ions. Depending on the experimental conditions, the crater depths corresponded to range values between the modal range and the range maximum. The observed crater depths could be related to the actual He concentration depth distributions by determining the profiles of the 4 He implants by 2.7 MeV proton backscattering. The implantation parameters affecting the exfoliation process, and especially the increase rate of the sample temperature, are investigated. The range distribution parameters for the 1.5 MeV 4 He implants are presented. ((orig.))

  8. Plasticity mechanisms in ultrafine grained freestanding aluminum thin films revealed by in-situ transmission electron microscopy nanomechanical testing

    International Nuclear Information System (INIS)

    Idrissi, Hosni; Kobler, Aaron; Amin-Ahmadi, Behnam; Schryvers, Dominique; Coulombier, Michael; Pardoen, Thomas; Galceran, Montserrat; Godet, Stéphane; Raskin, Jean-Pierre; Kübel, Christian

    2014-01-01

    In-situ bright field transmission electron microscopy (TEM) nanomechanical tensile testing and in-situ automated crystallographic orientation mapping in TEM were combined to unravel the elementary mechanisms controlling the plasticity of ultrafine grained Aluminum freestanding thin films. The characterizations demonstrate that deformation proceeds with a transition from grain rotation to intragranular dislocation glide and starvation plasticity mechanism at about 1% deformation. The grain rotation is not affected by the character of the grain boundaries. No grain growth or twinning is detected

  9. Plasticity mechanisms in ultrafine grained freestanding aluminum thin films revealed by in-situ transmission electron microscopy nanomechanical testing

    Energy Technology Data Exchange (ETDEWEB)

    Idrissi, Hosni, E-mail: hosni.idrissi@ua.ac.be [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-La-Neuve (Belgium); Kobler, Aaron [Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology - KIT, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Joint Research Laboratory Nanomaterials (KIT and TUD) at Technische Universität Darmstadt (TUD), Petersenstr. 32, 64287 Darmstadt (Germany); Amin-Ahmadi, Behnam; Schryvers, Dominique [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Coulombier, Michael; Pardoen, Thomas [Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-La-Neuve (Belgium); Galceran, Montserrat; Godet, Stéphane [Matters and Materials Department, Université Libre de Bruxelles, 50 Av. FD Roosevelt CP194/03, 1050 Brussels (Belgium); Raskin, Jean-Pierre [Information and Communications Technologies, Electronics and Applied Mathematics (ICTEAM), Microwave Laboratory, Université catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Kübel, Christian [Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology - KIT, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-03-10

    In-situ bright field transmission electron microscopy (TEM) nanomechanical tensile testing and in-situ automated crystallographic orientation mapping in TEM were combined to unravel the elementary mechanisms controlling the plasticity of ultrafine grained Aluminum freestanding thin films. The characterizations demonstrate that deformation proceeds with a transition from grain rotation to intragranular dislocation glide and starvation plasticity mechanism at about 1% deformation. The grain rotation is not affected by the character of the grain boundaries. No grain growth or twinning is detected.

  10. Effects of whole grain rye, with and without resistant starch type 2 supplementation, on glucose tolerance, gut hormones, inflammation and appetite regulation in an 11-14.5 hour perspective; a randomized controlled study in healthy subjects.

    Science.gov (United States)

    Sandberg, Jonna C; Björck, Inger M E; Nilsson, Anne C

    2017-04-21

    The prevalence of obesity is increasing worldwide and prevention is needed. Whole grain has shown potential to lower the risk of obesity, cardiovascular disease and type 2 diabetes. One possible mechanism behind the benefits of whole grain is the gut fermentation of dietary fiber (DF), e.g. non-starch polysaccharides and resistant starch (RS), in whole grain. The purpose of the study is to investigate the effect of whole grain rye-based products on glucose- and appetite regulation. Twenty-one healthy subjects were provided four rye-based evening test meals in a crossover overnight study design. The test evening meals consisted of either whole grain rye flour bread (RFB) or a 1:1 ratio of whole grain rye flour and rye kernels bread (RFB/RKB), with or without added resistant starch (+RS). White wheat flour bread (WWB) was used as reference evening meal. Blood glucose, insulin, PYY, FFA, IL-6 as well as breath H 2 and subjective rating of appetite were measured the following morning at fasting and repeatedly up to 3.5 h after a standardized breakfast consisting of WWB. Ad libitum energy intake was determined at lunch, 14.5 h after evening test and reference meals, respectively. The evening meal with RFB/RKB + RS decreased postprandial glucose- and insulin responses (iAUC) (P appetite regulation in a semi-acute perspective. Meanwhile, RFB and RFB/RKB improved subjective appetite ratings. The effects probably emanate from gut fermentation events. The study was registered at: ClinicalTrials.gov, register number NCT02347293 ( www.clinicaltrials.gov/ct2/show/NCT02347293 ). Registered 15 January 2015.

  11. Soft and Hard Tissue Changes around Tissue-Oriented Tulip-Design Implant Abutments: A 1-Year Randomized Prospective Clinical Trial.

    Science.gov (United States)

    Gutmacher, Zvi; Levi, Guy; Blumenfeld, Israel; Machtei, Eli E

    2015-10-01

    The advantages of platform switching using narrower abutments remain controversial. Many researchers suggest that platform switching can yield enhanced clinical results, while others remain skeptical. We hypothesize that the effectiveness of platform switching might be associated with the degree of reduction in size of the abutment. To radiographically and clinically examine a new abutment design created to move the implant-abutment interface farther medially. This was a prospective, randomized controlled clinical trial that included 27 patients (41 MIS Lance Plus® implants; MIS Implant Technologies, Karmiel, Israel). The patients' age ranged from 39 to 75 years. At the second stage of the surgery, the implants were randomly assigned to either the new platform switch Tulip abutment (TA) design or to the standard platform abutment (SA). Implant probing depth (IPD) and bleeding on probing (BOP) were recorded at baseline and after 12 months. Standardized periapical radiographs were taken (at baseline and at 12 months) and the marginal bone height measured. All implants were successfully integrated. The mean IPD at 1 year post-op was 2.91 mm for the SA group and 2.69 mm for the TA group (p > .05). Similarly, the BOP at 1 year was almost identical in both groups. The mean values of bone resorption at baseline were 0.98 ± 0.37 mm and 0.69 ± 0.20 for the TA and SA groups, respectively (p > .05). Bone loss (baseline to 12 months) was significantly greater in the SA group compared with the TA group. Use of the new TA, with its significantly downsized diameter, resulted in reduced bone loss at 1 year. Further research will be required to assess the long-term effect of this abutment on peri-implant health. © 2014 Wiley Periodicals, Inc.

  12. Kansas Agents Study Grain Marketing

    Science.gov (United States)

    Schoeff, Robert W.

    1973-01-01

    Author is an extension specialist in feed and grain marketing for Kansas State University. He describes a tour set up to educate members of the Kansas Grain and Feed Dealers' Association in the area of grain marketing and exporting. (GB)

  13. Advantageous grain boundaries in iron pnictide superconductors

    Science.gov (United States)

    Katase, Takayoshi; Ishimaru, Yoshihiro; Tsukamoto, Akira; Hiramatsu, Hidenori; Kamiya, Toshio; Tanabe, Keiichi; Hosono, Hideo

    2011-01-01

    High critical temperature superconductors have zero power consumption and could be used to produce ideal electric power lines. The principal obstacle in fabricating superconducting wires and tapes is grain boundaries—the misalignment of crystalline orientations at grain boundaries, which is unavoidable for polycrystals, largely deteriorates critical current density. Here we report that high critical temperature iron pnictide superconductors have advantages over cuprates with respect to these grain boundary issues. The transport properties through well-defined bicrystal grain boundary junctions with various misorientation angles (θGB) were systematically investigated for cobalt-doped BaFe2As2 (BaFe2As2:Co) epitaxial films fabricated on bicrystal substrates. The critical current density through bicrystal grain boundary (JcBGB) remained high (>1 MA cm−2) and nearly constant up to a critical angle θc of ∼9°, which is substantially larger than the θc of ∼5° for YBa2Cu3O7–δ. Even at θGB>θc, the decay of JcBGB was much slower than that of YBa2Cu3O7–δ. PMID:21811238

  14. Deformation bands in ⟨120⟩ grains in coarse-grained aluminium

    DEFF Research Database (Denmark)

    Bilde-Sørensen, Jørgen

    1986-01-01

    Coarse-grained aluminium, deformed in tension to a strain of 0.05, was examined in a scanning electron microscope by channelling contrast. Pronounced bands with a width typically of the order of 200 μm were found in some grains with an orientation close to [120]. When observed on surfaces close......)[011](111) and (a/2)[011](111). The Schmid factor for the highest stressed secondary systems has a local minimum of 0.245 at [120]. The application of Frank's equation shows that the only boundaries without long-range stresses that can be formed by combination of the two sets of dislocations, (a/2)- [011...

  15. Orienteering club

    CERN Multimedia

    Club d'orientation

    2015-01-01

    Course d'orientation La reprise des courses d’orientation était attendue dans la région puisque près de 150 coureurs ont participé à la première épreuve automnale organisée par le club d’orientation du CERN sur le site de La Faucille. Les circuits ont été remportés par Yann Locatelli du club d’Orientation Coeur de Savoie avec 56 secondes d’avance sur Damien Berguerre du club SOS Sallanches pour le parcours technique long, Marie Vuitton du club CO CERN (membre également de l’Equipe de France Jeune) pour le parcours technique moyen avec presque 4 minutes d’avance sur Jeremy Wichoud du club Lausanne-Jorat, Victor Dannecker pour le circuit technique court devant Alina Niggli, Elliot Dannecker pour le facile moyen et Alice Merat sur le facile court, tous membres du club O’Jura. Les résultats comp...

  16. Oriental cholangiohepatitis

    International Nuclear Information System (INIS)

    Scheible, F.W.; Davis, G.B.; California Univ., San Diego, La Jolla

    1981-01-01

    The recent influx of immigrants from Southeast Asia into the United States has increased the likelihood of encountering unusual diseases heretofore rarely seen in this country. Among these disorders is Oriental cholangiohepatitis, a potentially life-threatening process whose early diagnosis is facilitated by roentgenographic findings. Ultrasonography can also provide useful information, although potential pitfalls in diagnosis should be recognized. (orig.)

  17. Oriental cholangiohepatitis

    Energy Technology Data Exchange (ETDEWEB)

    Scheible, F.W.; Davis, G.B.

    1981-07-15

    The recent influx of immigrants from Southeast Asia into the United States has increased the likelihood of encountering unusual diseases heretofore rarely seen in this country. Among these disorders is Oriental cholangiohepatitis, a potentially life-threatening process whose early diagnosis is facilitated by roentgenographic findings. Ultrasonography can also provide useful information, although potential pitfalls in diagnosis should be recognized.

  18. Whole Grains and Fiber

    Science.gov (United States)

    ... for Physical Activity in Children My Family Health Tree What's that you're drinking? Get Active with ... grains. When grocery shopping, an easy way to identify healthy food choices is to look for the ...

  19. 6 Grain Yield

    African Journals Online (AJOL)

    create a favourable environment for rice ... developing lines adaptable to many ... have stable, not too short crop duration with ..... Analysis of variance of the effect of site and season on maturity, grain yield and plant ..... and yield components.

  20. Transport properties of olivine grain boundaries from electrical conductivity experiments

    Science.gov (United States)

    Pommier, Anne; Kohlstedt, David L.; Hansen, Lars N.; Mackwell, Stephen; Tasaka, Miki; Heidelbach, Florian; Leinenweber, Kurt

    2018-05-01

    Grain boundary processes contribute significantly to electronic and ionic transports in materials within Earth's interior. We report a novel experimental study of grain boundary conductivity in highly strained olivine aggregates that demonstrates the importance of misorientation angle between adjacent grains on aggregate transport properties. We performed electrical conductivity measurements of melt-free polycrystalline olivine (Fo90) samples that had been previously deformed at 1200 °C and 0.3 GPa to shear strains up to γ = 7.3. The electrical conductivity and anisotropy were measured at 2.8 GPa over the temperature range 700-1400 °C. We observed that (1) the electrical conductivity of samples with a small grain size (3-6 µm) and strong crystallographic preferred orientation produced by dynamic recrystallization during large-strain shear deformation is a factor of 10 or more larger than that measured on coarse-grained samples, (2) the sample deformed to the highest strain is the most conductive even though it does not have the smallest grain size, and (3) conductivity is up to a factor of 4 larger in the direction of shear than normal to the shear plane. Based on these results combined with electrical conductivity data for coarse-grained, polycrystalline olivine and for single crystals, we propose that the electrical conductivity of our fine-grained samples is dominated by grain boundary paths. In addition, the electrical anisotropy results from preferential alignment of higher-conductivity grain boundaries associated with the development of a strong crystallographic preferred orientation of the grains.

  1. The effect of crystallographic orientation on the active corrosion of pure magnesium

    International Nuclear Information System (INIS)

    Liu Ming; Qiu Dong; Zhao Mingchun; Song, Guangling; Atrens, Andrej

    2008-01-01

    An improved method was used to investigate the influence of crystallographic orientation on the corrosion of pure magnesium in 0.1 N HCl. The corrosion depth and orientation of surface features were mapped against crystallographic orientation (obtained by electron backscatter diffraction) for many off-principal magnesium crystals. The grains near (0 0 0 1) orientation are the most corrosion resistant. Most grains exhibited a striated structure of long and narrow hillocks with a unique direction

  2. Competitive grain growth in directional solidification investigated by phase field simulation

    International Nuclear Information System (INIS)

    Li Junjie; Wang Zhijun; Wang Jincheng; Yang Yujuan

    2012-01-01

    During directional solidification, the competitive dendritic growth between various oriented grains is a key factor to obtain desirable texture. In order to understand the mechanism of competitive dendritic growth, the phase field method was adopted to simulate the microstructure evolution of bicrystal samples. The simulation has well reproduced the whole competitive growth process for both diverging and converging dendrites. In converging case, besides the block of the unfavorably oriented dendrite by the favorably oriented one, the unfavorably oriented dendrite is also able to overgrow the favorable one under the condition of relatively low pulling velocity. This unusual overgrowth is dictated by the solute interaction of the converging dendrite tips. In diverging case, it was found that the grain boundary can be either inclined or parallel to the favorably oriented grain depending on the disposition of two grains.

  3. Mesoscopic simulation of recrystallization and grain growth

    International Nuclear Information System (INIS)

    Rollett, A.D.

    2000-01-01

    A brief summary of simulation techniques for recrystallization and grain growth is given. The available methods include surface evolver, front tracking (including finite element methods and vertex methods), networks of curves, phase field, cellular automata, and Monte Carlo. Two of the models that use a regular lattice, the Potts model and the Cellular Automaton (CA) model, have proved to be very useful. Microstructure is represented on a discrete lattice where the value of the field at each point represents the local orientation of the material and boundaries exist between points of unlike orientation. Two issues are discussed: one is a hybrid approach to combining the standard Monte Carlo and cellular automata algorithms for recrystallization modeling. The second is adaptation of the MC method for modeling grain growth (and recrystallization) with physically based boundary properties. Both models have significant limitations in their standard forms. The CA model is very useful and efficient for simulating recrystallization with deterministic motion of the recrystallization fronts. It can be adapted to simulate curvature driven migration provided that multiple sub-lattices are used with a probabilistic switching rule. The Potts model is very successful in modeling curvature driven boundary migration and grain growth. It does not simulate the proportionality between boundary velocity and a stored energy driving force, however, unless rather restricted conditions of stored energy (in relation to the grain boundary energy) and lattice temperature are satisfied. A new approach based on a hybrid of the Potts model (MC) and the Cellular Automaton (CA) model has been developed to obtain the desired limiting behavior for both curvature-driven and stored energy-driven grain boundary migration. The combination of methods is achieved by interleaving the two different types of reorientation event in time. The results show that the hybrid algorithm models the Gibbs

  4. In situ grain fracture mechanics during uniaxial compaction of granular solids

    Science.gov (United States)

    Hurley, R. C.; Lind, J.; Pagan, D. C.; Akin, M. C.; Herbold, E. B.

    2018-03-01

    Grain fracture and crushing are known to influence the macroscopic mechanical behavior of granular materials and be influenced by factors such as grain composition, morphology, and microstructure. In this paper, we investigate grain fracture and crushing by combining synchrotron x-ray computed tomography and three-dimensional x-ray diffraction to study two granular samples undergoing uniaxial compaction. Our measurements provide details of grain kinematics, contacts, average intra-granular stresses, inter-particle forces, and intra-grain crystal and fracture plane orientations. Our analyses elucidate the complex nature of fracture and crushing, showing that: (1) the average stress states of grains prior to fracture vary widely in their relation to global and local trends; (2) fractured grains experience inter-particle forces and stored energies that are statistically higher than intact grains prior to fracture; (3) fracture plane orientations are primarily controlled by average intra-granular stress and contact fabric rather than the orientation of the crystal lattice; (4) the creation of new surfaces during fracture accounts for a very small portion of the energy dissipated during compaction; (5) mixing brittle and ductile grain materials alters the grain-scale fracture response. The results highlight an application of combined x-ray measurements for non-destructive in situ analysis of granular solids and provide details about grain fracture that have important implications for theory and modeling.

  5. Film grain synthesis and its application to re-graining

    Science.gov (United States)

    Schallauer, Peter; Mörzinger, Roland

    2006-01-01

    Digital film restoration and special effects compositing require more and more automatic procedures for movie regraining. Missing or inhomogeneous grain decreases perceived quality. For the purpose of grain synthesis an existing texture synthesis algorithm has been evaluated and optimized. We show that this algorithm can produce synthetic grain which is perceptually similar to a given grain template, which has high spatial and temporal variation and which can be applied to multi-spectral images. Furthermore a re-grain application framework is proposed, which synthesises based on an input grain template artificial grain and composites this together with the original image content. Due to its modular approach this framework supports manual as well as automatic re-graining applications. Two example applications are presented, one for re-graining an entire movie and one for fully automatic re-graining of image regions produced by restoration algorithms. Low computational cost of the proposed algorithms allows application in industrial grade software.

  6. Measuring the elastic strain of individual grains in polycrystalline materials

    DEFF Research Database (Denmark)

    AllB, which fits centre-of-mass grain positions, orientations and strain tensors from the experimental far-field 3DXRD data, was developed. The program builds on peaksearch, ImageD11 and GrainSpotter and will eventually be implemented in the Fable GUI. By the use of simulated data the presentation will focus...... a careful calibration of the global parameters relating to the experiment (sample-to-detector distance, tilts of detector and sample and beam centre on detector) must be performed. For this purpose the option of fitting the global parameters simultaneously for any number of indexed grains is included in Fit...

  7. New deformation model of grain boundary strengthening in polycrystalline metals

    International Nuclear Information System (INIS)

    Trefilov, V.I.; Moiseev, V.F.; Pechkovskij, Eh.P.

    1988-01-01

    A new model explaining grain boundary strengthening in polycrystalline metals and alloys by strain hardening due to localization of plastic deformation in narrow bands near grain boundaries is suggested. Occurrence of localized deformation is caused by different flow stresses in grains of different orientation. A new model takes into account the active role of stress concentrator, independence of the strengthening coefficient on deformation, influence of segregations. Successful use of the model suggested for explanation of rhenium effect in molybdenum and tungsten is alloys pointed out

  8. Orientation Club

    CERN Multimedia

    Club d'orientation

    2014-01-01

    COURSE ORIENTATION Résultats de samedi 10 mai    C’est sur une carte entièrement réactualisée dans les bois de Versoix, que plus de 100 coureurs sont venus participer à la course d’orientation, type longue distance, préparée par des membres du club du CERN. Le terrain plutôt plat nécessitait une orientation à grande vitesse, ce qui a donné les podiums suivants :  Technique long avec 17 postes : 1er Jurg Niggli, O’Jura en 52:48, 2e Beat Muller, COLJ Lausanne-Jorat en 58:02, 3e Christophe Vuitton, CO CERN en 58:19 Technique moyen avec 13 postes : 1er Jean-Bernard Zosso, CO CERN, en 46:05 ; 2e Yves Rousselot, Balise 25 Besançon, en 55:11 ; 3e Laurent Merat, O'Jura, en 55:13 Technique court avec 13 postes : 1er Julien Vuitton, CO CERN en 40:59, 2e Marc Baumgartner, CO CERN en 43:18, 3e Yaelle Mathieu en 51:42 Su...

  9. Orienteering Club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    Courses d’orientation ce printemps Le Club d’orientation du CERN vous invite à venir découvrir la course d’orientation et vous propose, en partenariat avec d’autres clubs de la région, une dizaine de courses populaires. Celles-ci ont lieu les samedis après-midi, elles sont ouvertes à tous, quel que soit le niveau, du débutant au sportif confirmé, en famille ou en individuel, en promenade ou en course. Si vous êtes débutant vous pouvez profiter d’une petite initiation offerte par l’organisateur avant de vous lancer sur un parcours. Divers types de parcours sont à votre choix lors de chaque épreuve : facile court (2-3 km), facile moyen (3-5 km), technique court (3-4 km), technique moyen (4-5 km) et technique long (5-7 km). Les dates à retenir sont les suivantes : Samedi 23 mars: Pully (Vd) Samedi 13 avril: Pougny...

  10. Effect of Thermomechanical Processing and Crystallographic Orientation on the Corrosion Behavior of API 5L X70 Pipeline Steel

    Science.gov (United States)

    Ohaeri, Enyinnaya; Omale, Joseph; Eduok, Ubong; Szpunar, Jerzy

    2018-04-01

    This work presents the electrochemical response of X70 pipeline steel substrates thermomechanically processed at different conditions. The WE sample was hot rolled at a temperature range of 850 °C to 805 °C and cooled at a rate of 42.75 °C/s. Another sample WD was hot rolled from 880 °C to 815 °C and cooled at a faster rate of 51.5 °C/s. Corrosion tests were conducted electrochemically by potentiodynamic polarization in hydrogen-charged and non-hydrogen-charged environments. A lower corrosion rate was measured with hydrogen charging due to the rapid formation of corrosion product film on pipeline substrate, but WE specimen emerged as the most susceptible to corrosion with and without hydrogen charging. Variations in thermomechanical rolling conditions influenced grain orientation, protective film properties, corrosion, and cracking behavior on both specimens. Cracks were seen in both specimens after hydrogen charging, but specimen WE experienced a more intense deterioration of protective corrosion product film and subsequent cracking. A large part of specimen WD retained its protective corrosion product film after the polarization test, and sites where spalling occurred resulted in pitting with less cracking. Despite weak crystallographic texture noticed in both specimens, WD showed a higher intensity of corrosion-resistant 111||ND-oriented grains, while WE showed a more random distribution of 111||ND-, 011||ND-, and 001||ND-oriented grains with a lower intensity.

  11. Effect of Thermomechanical Processing and Crystallographic Orientation on the Corrosion Behavior of API 5L X70 Pipeline Steel

    Science.gov (United States)

    Ohaeri, Enyinnaya; Omale, Joseph; Eduok, Ubong; Szpunar, Jerzy

    2018-06-01

    This work presents the electrochemical response of X70 pipeline steel substrates thermomechanically processed at different conditions. The WE sample was hot rolled at a temperature range of 850 °C to 805 °C and cooled at a rate of 42.75 °C/s. Another sample WD was hot rolled from 880 °C to 815 °C and cooled at a faster rate of 51.5 °C/s. Corrosion tests were conducted electrochemically by potentiodynamic polarization in hydrogen-charged and non-hydrogen-charged environments. A lower corrosion rate was measured with hydrogen charging due to the rapid formation of corrosion product film on pipeline substrate, but WE specimen emerged as the most susceptible to corrosion with and without hydrogen charging. Variations in thermomechanical rolling conditions influenced grain orientation, protective film properties, corrosion, and cracking behavior on both specimens. Cracks were seen in both specimens after hydrogen charging, but specimen WE experienced a more intense deterioration of protective corrosion product film and subsequent cracking. A large part of specimen WD retained its protective corrosion product film after the polarization test, and sites where spalling occurred resulted in pitting with less cracking. Despite weak crystallographic texture noticed in both specimens, WD showed a higher intensity of corrosion-resistant 111|| ND-oriented grains, while WE showed a more random distribution of 111|| ND-, 011|| ND-, and 001|| ND-oriented grains with a lower intensity.

  12. Coarse-graining complex dynamics

    DEFF Research Database (Denmark)

    Sibani, Paolo

    2013-01-01

    Continuous Time Random Walks (CTRW) are widely used to coarse-grain the evolution of systems jumping from a metastable sub-set of their configuration space, or trap, to another via rare intermittent events. The multi-scaled behavior typical of complex dynamics is provided by a fat...... macroscopic variables all produce identical long time relaxation behaviors. Hence, CTRW shed no light on the link between microscopic and macroscopic dynamics. We then highlight how a more recent approach, Record Dynamics (RD) provides a viable alternative, based on a very different set of physical ideas......: while CTRW make use of a renewal process involving identical traps of infinite size, RD embodies a dynamical entrenchment into a hierarchy of traps which are finite in size and possess different degrees of meta-stability. We show in particular how RD produces the stretched exponential, power...

  13. Simulation study on the growth of grains in dusty plasmas

    International Nuclear Information System (INIS)

    Sato, Tetsuya; Watanabe, Kunihiko

    1997-01-01

    A new particle simulation code is developed for studying the dynamics of the grains which are exposed to charging by the background plasma particles. Effects of regular attachment of electrons and ions, effects of secondary electron emission, and coagulation of grains are included in this code. Simulation results show that grains randomly change their charges from negative to positive, or from positive to negative in a 'flip-flop' fashion as a result of competition between the electron attachment and secondary electron emission. It is found that the flip-flop effect becomes remarkable when the radius of grains is of the order of 10 nm, because the attachment of a single electron to a grain is less effective on the surface potential for larger grains, while the average probability of electron attachment is smaller for smaller grains. Grains with opposite charges attract each other to coagulate, so that grains of size of 10 nm are likely to grow in size. The flip-flop effect is found to be essential to the growth of grains. (author)

  14. Grain boundary structure and properties

    International Nuclear Information System (INIS)

    Balluffi, R.W.

    1979-01-01

    An attempt is made to distinguish those fundamental aspects of grain boundaries which should be relevant to the problem of the time dependent fracture of high temperature structural materials. These include the basic phenomena which are thought to be associated with cavitation and cracking at grain boundaries during service and with the more general microstructural changes which occur during both processing and service. A very brief discussion of the current state of our knowledge of these fundamentals is given. Included are the following: (1) structure of ideal perfect boundaries; (2) defect structure of grain boundaries; (3) diffusion at grain boundaries; (4) grain boundaries as sources/sinks for point defects; (5) grain boundary migration; (6) dislocation phenomena at grain boundaries; (7) atomic bonding and cohesion at grain boundaries; (8) non-equilibrium properties of grain boundaries; and (9) techniques for studying grain boundaries

  15. Radiation disinfestation of grain

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1962-10-15

    A panel was convened by the International Atomic Energy Agency to consider ways of applying radiation to grain handling and insect control, and to make recommendations on the advisability and nature of any future action in this field. Among other subjects, the panel discussed the use of electron accelerators and gamma radiation for grain disinfestation as well as problems of radiation entomology and wholesomeness of irradiated grain. After reviewing the present state of knowledge regarding radiation disinfestation of grain, the experts agreed that pilot plant operations be initiated as soon as practicable in order to evaluate the use of irradiation plants under practical conditions in their entomological, engineering and economic aspects. They recommended that research effort be directed towards solving certain fundamental problems related to the proposed pilot plant projects; such as rapid methods for differentiation between sterile insects and normal ones; study of the metabolism of irradiated immature stages of insects in relation to the heating of treated grain; research into possible induction of radiation resistance; irradiation susceptibility of insects which show resistance to conventional insecticides; and study of methods of sensitizing insects to irradiation damage. It was also pointed out that the distribution of irradiated food for human consumption was controlled in most countries under present legislative procedures, and no country had yet approved radiation treatment of cereals. The experts recommended that countries in a position to submit evidence to their appropriate authorities regarding the wholesomeness of irradiated cereals should be encouraged to do so as soon as possible. Regarding the engineering aspects of irradiation pilot plant projects, the experts noted that the process could be automated and operated safely. Electron accelerators and cobalt sources could be used for all the throughput rates utilized in most conventional grain

  16. Computerized radioautographic grain counting

    International Nuclear Information System (INIS)

    McKanna, J.A.; Casagrande, V.A.

    1985-01-01

    In recent years, radiolabeling techniques have become fundamental assays in physiology and biochemistry experiments. They also have assumed increasingly important roles in morphologic studies. Characteristically, radioautographic analysis of structure has been qualitative rather than quantitative, however, microcomputers have opened the door to several methods for quantifying grain counts and density. The overall goal of this chapter is to describe grain counting using the Bioquant, an image analysis package based originally on the Apple II+, and now available for several popular microcomputers. The authors discuss their image analysis procedures by applying them to a study of development in the central nervous system

  17. Radiation disinfestation of grain

    International Nuclear Information System (INIS)

    1962-01-01

    A panel was convened by the International Atomic Energy Agency to consider ways of applying radiation to grain handling and insect control, and to make recommendations on the advisability and nature of any future action in this field. Among other subjects, the panel discussed the use of electron accelerators and gamma radiation for grain disinfestation as well as problems of radiation entomology and wholesomeness of irradiated grain. After reviewing the present state of knowledge regarding radiation disinfestation of grain, the experts agreed that pilot plant operations be initiated as soon as practicable in order to evaluate the use of irradiation plants under practical conditions in their entomological, engineering and economic aspects. They recommended that research effort be directed towards solving certain fundamental problems related to the proposed pilot plant projects; such as rapid methods for differentiation between sterile insects and normal ones; study of the metabolism of irradiated immature stages of insects in relation to the heating of treated grain; research into possible induction of radiation resistance; irradiation susceptibility of insects which show resistance to conventional insecticides; and study of methods of sensitizing insects to irradiation damage. It was also pointed out that the distribution of irradiated food for human consumption was controlled in most countries under present legislative procedures, and no country had yet approved radiation treatment of cereals. The experts recommended that countries in a position to submit evidence to their appropriate authorities regarding the wholesomeness of irradiated cereals should be encouraged to do so as soon as possible. Regarding the engineering aspects of irradiation pilot plant projects, the experts noted that the process could be automated and operated safely. Electron accelerators and cobalt sources could be used for all the throughput rates utilized in most conventional grain

  18. Discrete stochastic charging of aggregate grains

    Science.gov (United States)

    Matthews, Lorin S.; Shotorban, Babak; Hyde, Truell W.

    2018-05-01

    Dust particles immersed in a plasma environment become charged through the collection of electrons and ions at random times, causing the dust charge to fluctuate about an equilibrium value. Small grains (with radii less than 1 μm) or grains in a tenuous plasma environment are sensitive to single additions of electrons or ions. Here we present a numerical model that allows examination of discrete stochastic charge fluctuations on the surface of aggregate grains and determines the effect of these fluctuations on the dynamics of grain aggregation. We show that the mean and standard deviation of charge on aggregate grains follow the same trends as those predicted for spheres having an equivalent radius, though aggregates exhibit larger variations from the predicted values. In some plasma environments, these charge fluctuations occur on timescales which are relevant for dynamics of aggregate growth. Coupled dynamics and charging models show that charge fluctuations tend to produce aggregates which are much more linear or filamentary than aggregates formed in an environment where the charge is stationary.

  19. Columns formed by multiple twinning in nickel layers—An approach of grain boundary engineering by electrodeposition

    DEFF Research Database (Denmark)

    Alimadadi, Hossein; da Silva Fanta, Alice Bastos; Somers, Marcel A. J.

    2013-01-01

    grain boundaries. A peculiar arrangement of Σ3 boundaries forming five-fold junctions is observed. The resulting microstructure meets the requirements for grain boundary engineering. Twinning induced effects on the crystallographic orientation of grains result in one major texture component being a ⟨210......⟩ fiber axis and additional minor orientations originating from first and second generation twins of ⟨210⟩, i.e., ⟨542⟩ and ⟨20 2 1⟩....

  20. Grain boundary motion and grain rotation in aluminum bicrystals: recent experiments and simulations

    International Nuclear Information System (INIS)

    Molodov, D A; Barrales-Mora, L A; Brandenburg, J-E

    2015-01-01

    The results of experimental and computational efforts over recent years to study the motion of geometrically different grain boundaries and grain rotation under various driving forces are briefly reviewed. Novel in-situ measuring techniques based on orientation contrast imaging and applied simulation techniques are described. The experimental results obtained on specially grown aluminum bicrystals are presented and discussed. Particularly, the faceting and migration behavior of low angle grain boundaries under the curvature force is addressed. In contrast to the pure tilt boundaries, which remained flat/faceted and immobile during annealing at elevated temperatures, mixed tilt-twist boundaries readily assumed a curved shape and steadily moved under the capillary force. Computational analysis revealed that this behavior is due to the inclinational anisotropy of grain boundary energy, which in turn depends on boundary geometry. The shape evolution and shrinkage kinetics of cylindrical grains with different tilt and mixed boundaries were studied by molecular dynamics simulations. The mobility of low angle <100> boundaries with misorientation angles higher than 10°, obtained by both the experiments and simulations, was found not to differ from that of the high angle boundaries, but decreases essentially with further decrease of misorientation. The shape evolution of the embedded grains in simulations was found to relate directly to results of the energy computations. Further simulation results revealed that the shrinkage of grains with pure tilt boundaries is accompanied by grain rotation. In contrast, grains with the tilt-twist boundaries composed of dislocations with the mixed edge-screw character do not rotate during their shrinkage. Stress driven boundary migration in aluminium bicrystals was observed to be coupled to a tangential translation of the grains. The activation enthalpy of high angle boundary migration was found to vary non-monotonically with

  1. Orienteering club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    Courses d’orientation Le soleil enfin de retour a incité nombre de sportifs et promeneurs à nous rejoindre dans la belle forêt de Challex /Pougny pour la deuxième étape de notre coupe de printemps 2013. Certains sont revenus crottés et fourbus alors que d’autres avaient les joues bien roses après un grand bol d’air frais. Mais tous avaient passé un agréable moment dans la nature. Nous rappelons que nos activités sont ouvertes à tous, jeunes, moins jeunes, sportifs, familles, du CERN ou d’ailleurs, et que le seul inconvénient est que si vous goûtez à la course d’orientation, il vous sera difficile de ne pas y revenir ! Samedi 20 avril 2013, nous serons sur le Mont Mourex (entre Gex et Divonne) pour notre prochaine épreuve et vous y serez les bienvenus. Les inscriptions et les départ...

  2. Orienteering club

    CERN Multimedia

    Club d’Orientation du CERN

    2015-01-01

    Courses d’orientation Nouvelle saison nouveau programme Le Club d’orientation du CERN, en partenariat avec d’autres clubs de la région, vous propose une dizaine de courses populaires comptant pour la coupe Genevoise de printemps: samedi 28 mars: Vernand Dessus samedi 18 avril: Pougny/Challex samedi 25 avril: Chancy/Valleiry samedi 2 mai: Mauvernay samedi 9 mai: Longchaumois samedi 16 mai: Genolier samedi 30 mai: Prevondavaux samedi 6 juin: Biere-Ballens samedi 13 juin: Haut-Jura samedi 20 juin: Bonmont - Finale Ces courses sont ouvertes à tous, quel que soit le niveau, du débutant au sportif confirmé, en famille ou en individuel, en promenade ou en course. Les inscriptions se font sur place le jour de l’épreuve. Si vous êtes débutant, vous pouvez profiter d’une initiation offerte par l’organisateur avant de vous lancer sur un parcours. Le club propose aussi...

  3. Orienteering club

    CERN Multimedia

    Orienteering Club

    2016-01-01

    Course d'orientation Calendrier des courses d’orientation Coupe genevoise d’automne 2016 Samedi 3 septembre : La Faucille (01) Samedi 10 septembre : Prémanon (39) Samedi 17 septembre : Saint-Cergue (VD) Samedi 24 septembre : Jorat / Corcelles (VD) Samedi 1 octobre: Bière - Ballens (VD) -relais Vendredi 14 octobre : Parc Mon Repos (GE) - nocturne Samedi 15 octobre : Terrasse de Genève (74) Samedi 29 octobre : Bonmont (VD) Samedi 5 novembre : Pomier (74) – one-man-relay - Finale   Courses ouvertes à toutes et à tous, sportifs, familles, débutants ou confirmés, du CERN ou d’ailleurs. Cinq circuits disponibles, ceci va du facile court (2 km) adapté aux débutants et aux enfants jusqu’au parcours technique long de 6 km pour les chevronnés en passant par les parcours facile moyen (4&am...

  4. COURSE ORIENTATION

    CERN Multimedia

    Club d'orientation du CERN

    2015-01-01

      Les coureurs d’orientation de la région se sont donné rendez-vous samedi dernier dans les bois de Pougny/Challex lors de l’épreuve organisée par le club d’orientation du CERN. La carte proposée pour les 5 circuits offrait aussi bien un coté très technique avec un relief pentu qu’un coté avec de grandes zones plates à forêt claire. Le parcours technique long comportant 20 postes a été remporté par Beat Muller du COLJ Lausanne en 56:26 devançant Denis Komarov, CO CERN en 57:30 et Yvan Balliot, ASO Annecy en 57:46. Pour les autres circuits les résultats sont les suivants: Technique moyen (13 postes): 1er Joël Mathieu en 52:32 à une seconde du 2e Vladimir Kuznetsov, COLJ Lausanne-Jorat, 3e Jean-Bernard Zosso, CO CERN, en 54:01 Technique court (12 postes): 1er Lennart Jirden, ...

  5. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2013-01-01

    Course d’orientation Face aux Championnats de France des Clubs à Poitiers, et à une météo hivernale (vent glaciale et pluie), il ne restait qu’une cinquantaine d’orienteurs pour participer à l’épreuve organisée le samedi 25 mai à Grange-Malval. Les participants ont tout de même bien apprécié les 5 circuits proposés par le Satus Genève. Les résultats sont disponibles sur notre site http://cern.ch/club-orientation. En plus des résultats, vous pourrez noter des informations sur la nouvelle école de CO encadrée par B. Barge, Prof. EPS à Ferney-Voltaire pour les jeunes à partir de 6 ans. La prochaine étape de la coupe genevoise se déroulera samedi 1er juin à Morez (39). Epreuve organisée par le club O’Jura&nb...

  6. Orienteering Club

    CERN Multimedia

    Le Club d’orientation du CERN

    2017-01-01

    COURSE ORIENTATION Finale de la coupe d’automne Le club d’orientation du CERN (COC Genève) a organisé sa dernière course populaire de la saison samedi 4 novembre au lieu-dit Les Terrasses de Genève (74). Cette 9e épreuve qui se courait sous la forme d’un One-Man-Relay, clôturait ainsi la coupe genevoise d’automne dont les lauréats sont : Circuit technique long : 1. Julien Vuitton (COC Genève), 2. Berni Wehrle (COC Genève), 3. Christophe Vuitton (COC Genève). Circuit technique moyen : 1. Vladimir Kuznetsov (Lausanne-Jorat), 2. J.-Bernard Zosso (COC Genève), 3. Laurent Merat (O’Jura). Circuit technique court : 1. Thibault Rouiller (COC Genève), 2. exæquo Lennart Jirden (COC Genève) et Katya Kuznetsova (Lausanne-Jorat). Circuit facile moyen : 1. Tituan Barge ...

  7. Orienteering Club

    CERN Multimedia

    Le Club d’orientation du CERN

    2017-01-01

    COURSE ORIENTATION Finale de la coupe d’automne Le club d’orientation du CERN (COC Genève) a organisé sa dernière course populaire de la saison samedi 4 novembre au lieu-dit Les Terrasses de Genève (74). Cette 9e épreuve qui se courait sous la forme d’un One-Man-Relay, clôturait ainsi la coupe genevoise d’automne dont les lauréats sont : Circuit technique long : 1. Julien Vuitton (COC Genève), 2. Berni Wehrle (COC Genève), 3. Christophe Vuitton (COC Genève). Circuit technique moyen : 1. Vladimir Kuznetsov (Lausanne-Jorat), 2. J.-Bernard Zosso (COC Genève), 3. Laurent Merat (O’Jura). Circuit technique court : 1. Thibault Rouiller (COC Genève), 2. exæquo Lennart Jirden (COC Genève) et Katya Kuznetsova (Lausanne-Jorat). Circuit facile moyen : 1. Tituan Barge...

  8. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2015-01-01

    Course orientation C’est au pied du Salève, proche du Golf de Bosset, que le club d’orientation du CERN (CO CERN) a organisé samedi 19 septembre une nouvelle épreuve comptant pour la Coupe Genevoise d’automne. La zone « des Terrasses de Genève » avait été cartographiée et mise en service l’année dernière. Les participants ont pu apprécier un terrain ludique avec beaucoup de microreliefs, de points d’eau et de gros rochers, le tout au milieu d’une forêt assez claire et agréable à courir. Sur le parcours technique long, le résultat a été très serré puisque Pierrick Merino du club d’Annecy a gagné avec seulement 9 secondes d’avance sur Gaëtan Vuitton (CO CERN) qui confiait avoir perdu beaucoup du te...

  9. Orienteering Club

    CERN Multimedia

    Le Club d’orientation du CERN

    2017-01-01

    Course orientation Les courses d’orientation comptant pour la coupe genevoise de printemps s’enchainent dans la région franco-suisse. Samedi dernier, une bonne centaine de coureurs se sont retrouvés au Mont Mourex où le club du CERN avait préparé la sixième épreuve. A l’issue de la course, les participants confirmaient l’exigence des circuits, à savoir la condition physique et le côté technique du traçage. Le parcours technique long comportant 20 postes a été remporté par Darrell High du Care Vevey en 1:22:38 devançant Beat Muller du COLJ Lausanne-Jorat en 1:25:25 et Alison High également du Care Vevey en 1:28:51. Le circuit technique moyen a été remporté par Christophe Vuitton du CO CERN et le circuit technique court par Claire-Lise Rouiller, CO CERN. Les trois pr...

  10. Orienteering Club

    CERN Multimedia

    Club d'orientation

    2010-01-01

    COURSE D’ORIENTATION La finale de la coupe de printemps Après avoir remporté le challenge club, samedi 29 juin lors du relais inter-club à Lausanne, le Club d’orientation du CERN organisait la dernière étape de la coupe genevoise de printemps samedi 5 juin à Saint-Cergue dans les bois de Monteret (Canton de Vaud). Plus de 100 participants se sont déplacés pour venir participer à la finale et découvrir une toute nouvelle carte dans une forêt vallonnée. Les résultats pour chaque circuit de cette étape sont : Technique long : 1. Jurg Niggli du club O’Jura, 2. Clément Poncet, 3. Oystein Midttun. Technique moyen : 1. Zoltan Trocsanyi CO CERN, 2. Christophe Ingold, 3. Christina Falga. Technique court : 1. Pierre-Andre Baum, CARE Vevey, 2. Emese Szunyog, 3. Solène Balay. Facile moyen : 1. Elisa P...

  11. Club Orientation

    CERN Multimedia

    Club d'orientation

    2014-01-01

      COURSE ORIENTATION   Pas moins de 100 concurrents sont venus s’affronter sur les parcours proposés par le club d’orientation du CERN ce samedi 26 avril lors de la 4e étape de la coupe genevoise de printemps. Les podiums ont été attribués à :  Technique long avec 19 postes : 1er Yvan Balliot, ASO Annecy en 1:01:39 ; 2e Dominique Fleurent, ASO Annecy, en 1:05:12 ; 3e Rémi Fournier, SOS Sallanches, en 1:05:40. Technique moyen avec 14 postes : 1er Jean-Bernard Zosso, CO CERN, en 46:42 ; 2e Céline Zosso, CO CERN, en 50:51 ; 3e Clément Poncet, O’Jura Prémanon, en 51:27. Technique court avec 13 postes : 1er Jaakko Murtomaki, YKV Seinaejoki, en 36:04 ; 2e Marc Baumgartner en 41:27 ; 3e Natalia Niggli, O’Jura Prémanon, en 52:43. Sur les parcours facile moyen et facile court, victoire respectivement de Stéphanie...

  12. Orienteering Club

    CERN Multimedia

    Le Club d’orientation du CERN

    2017-01-01

    Calendrier des courses de la Coupe Genevoise – printemps 2017 Club d'orientation - Julien,  jeune membre du club. Le Club d’orientation du CERN, en partenariat avec d’autres clubs de la région, vous propose une série de courses populaires, qui se dérouleront des deux côtés de la frontière franco-suisse, à savoir : Samedi 1 avril : Pougny/Challex (01) Samedi 8 avril: Ballens (VD) Samedi 22 avril: Apples (VD) Samedi 29 avril: Mont Mussy (01) Samedi 6 mai: Prémanon (39) Samedi 13 mai: Mont Mourex (01) Samedi 20 mai: Prévondavaux (VD) Samedi 10 juin: Chancy/Valleiry (74) Samedi 17 juin: Trélex - Finale (VD) Ces courses sont ouvertes à tous, quel que soit le niveau, du débutant au sportif confirmé, en famille ou en individuel. Les inscriptions sur un des 5 parcours proposés se font sur place le jour de l...

  13. Moniliformin in Norwegian grain

    NARCIS (Netherlands)

    Uhlig, S.; Torp, M.; Jarp, J.; Parich, A.; Gutleb, A.C.; Krska, R.

    2004-01-01

    Norwegian grain samples (73 oats, 75 barley, 83 wheat) from the 2000-02 growing seasons were examined for contamination with moniliformin, and the association between the fungal metabolite and the number of kernels infected with common Fusaria was investigated. Before quantification of moniliformin

  14. Assessing the grain structure of highly X-ray absorbing metallic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bormann, Therese [Basel Univ. (Switzerland). Biomaterials Science Center; University of Applied Sciences Northwestern Switzerland, Muttenz (Switzerland). Inst. for Medical and Analytical Technologies; Beckmann, Felix [Helmholtz-Zentrum Geesthacht (Germany). Inst. of Materials Research; Schinhammer, Michael [Eidgenoessische Technische Hochschule (ETH), Zuerich (Switzerland). Dept. of Materials; Deyhle, Hans; Mueller, Bert [Basel Univ. (Switzerland). Biomaterials Science Center; Wild, Michael de [University of Applied Sciences Northwestern Switzerland, Muttenz (Switzerland). Inst. for Medical and Analytical Technologies

    2014-07-15

    Selective laser melting allows the fabrication of NiTi implants with pre-defined, complex shapes. The control of the process parameters regulates the arrangement of the granular microstructure of the NiTi alloy. We prepared specimens with elongated grains, which build a sound basis for diffraction contrast tomography experiments using synchrotron radiation and for electron backscatter diffraction measurements. Both approaches reveal the orientation and size of the individual grains within the specimen. Still, electron backscatter diffraction is confined to two-dimensional cross-sections while diffraction contrast tomography reveals these microstructural features in three dimensions. We demonstrate that the grains in the selective laser melted specimen, which are oriented along the building direction, do not exhibit a well-defined planar grain orientation but are twisted. These twisted grains give rise to diffraction spots observable for several degrees of specimen rotation simultaneously to the acquisition of tomography data. (orig.)

  15. Effect of ultrafine grain on tensile behaviour and corrosion resistance of the duplex stainless steel.

    Science.gov (United States)

    Jinlong, Lv; Tongxiang, Liang; Chen, Wang; Limin, Dong

    2016-05-01

    The ultrafine grained 2205 duplex stainless steel was obtained by cold rolling and annealing. The tensile properties were investigated at room temperature. Comparing with coarse grained stainless steel, ultrafine grained sample showed higher strength and plasticity. In addition, grain size changed deformation orientation. The strain induced α'-martensite was observed in coarse grained 2205 duplex stainless steel with large strain. However, the grain refinement inhibited the transformation of α'-martensite;nevertheless, more deformation twins improved the strength and plasticity of ultrafine grained 2205 duplex stainless steel. In addition, the grain refinement improved corrosion resistance of the 2205 duplex stainless steel in sodium chloride solution. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Why do interstellar grains exist

    International Nuclear Information System (INIS)

    Seab, C.G.; Hollenbach, D.J.; Mckee, C.F.; Tielens, A.G.G.M.

    1986-01-01

    There exists a discrepancy between calculated destruction rates of grains in the interstellar medium and postulated sources of new grains. This problem was examined by modelling the global life cycle of grains in the galaxy. The model includes: grain destruction due to supernovae shock waves; grain injection from cool stars, planetary nebulae, star formation, novae, and supernovae; grain growth by accretion in dark clouds; and a mixing scheme between phases of the interstellar medium. Grain growth in molecular clouds is considered as a mechanism or increasing the formation rate. To decrease the shock destruction rate, several new physical processes, such as partial vaporization effects in grain-grain collisions, breakdown of the small Larmor radius approximation for betatron acceleration, and relaxation of the steady-state shock assumption are included

  17. Orientation aspects of growth during recrystallization

    International Nuclear Information System (INIS)

    Juul Jensen, D.

    1997-04-01

    Recrystallization of heavily cold rolled aluminium and copper is studied with the aim of achieving information about effects of crystallography orientation on the growth process. The potentials of several experimental techniques are analysed, and a method well suited for characterizing growth rates of grains with different orientations is developed. This method, which is referred to as the extended Cahn-Hagel method, is used for growth rate determinations in aluminium and copper deformed and annealed under five different conditions. In all the investigated cases, preferential growth of cube oriented grains is observed. Recrystallization models, which simulates the orientational as well as microstructural development, are described. selected models are applied for studies of recrystallization in aluminium and copper under specific deformation and annealing conditions as well as for more general studies of the effects of orientation dependent growth rates on the recrystallization microstructure and texture. Finally, reasons for the observed orientation dependent growth rates are discussed. A new mechanism, orientation pinning, is suggested and it is shown that this mechanism is necessary for the understanding of experimental results. (au) 4 tabs., 41 ills., 153 refs

  18. Orientation aspects of growth during recrystallization

    Energy Technology Data Exchange (ETDEWEB)

    Juul Jensen, D.

    1997-04-01

    Recrystallization of heavily cold rolled aluminium and copper is studied with the aim of achieving information about effects of crystallography orientation on the growth process. The potentials of several experimental techniques are analysed, and a method well suited for characterizing growth rates of grains with different orientations is developed. This method, which is referred to as the extended Cahn-Hagel method, is used for growth rate determinations in aluminium and copper deformed and annealed under five different conditions. In all the investigated cases, preferential growth of cube oriented grains is observed. Recrystallization models, which simulates the orientational as well as microstructural development, are described. selected models are applied for studies of recrystallization in aluminium and copper under specific deformation and annealing conditions as well as for more general studies of the effects of orientation dependent growth rates on the recrystallization microstructure and texture. Finally, reasons for the observed orientation dependent growth rates are discussed. A new mechanism, orientation pinning, is suggested and it is shown that this mechanism is necessary for the understanding of experimental results. (au) 4 tabs., 41 ills., 153 refs.

  19. Towards realistic molecular dynamics simulations of grain boundary mobility

    International Nuclear Information System (INIS)

    Zhou, J.; Mohles, V.

    2011-01-01

    In order to investigate grain boundary migration by molecular dynamics (MD) simulations a new approach involving a crystal orientation-dependent driving force has been developed by imposing an appropriate driving force on grain boundary atoms and enlarging the effective range of driving force. The new approach has been validated by the work of the driving force associated with the motion of grain boundaries. With the new approach the relation between boundary migration velocity and driving force is found to be nonlinear, as was expected from rate theory for large driving forces applied in MD simulations. By evaluating grain boundary mobility nonlinearly for a set of symmetrical tilt boundaries in aluminum at high temperature, high-angle grain boundaries were shown to move much faster than low-angle grain boundaries. This agrees well with experimental findings for recrystallization and grain growth. In comparison with the available data the simulated mobility of a 38.21 o Σ7 boundary was found to be significantly lower than other MD simulation results and comparable with the experimental values. Furthermore, the average volume involved during atomic jumps for boundary migration is determined in MD simulations for the first time. The large magnitude of the volume indicates that grain boundary migration is accomplished by the correlated motion of atom groups.

  20. Ultra-low-angle boundary networks within recrystallizing grains

    DEFF Research Database (Denmark)

    Ahl, Sonja Rosenlund; Simons, Hugh; Zhang, Yubin

    2017-01-01

    We present direct evidence of a network of well-defined ultra-low-angle boundaries in bulk recrystallizing grains of 99.5% pure aluminium (AA1050) by means of a new, three-dimensional X-ray mapping technique; dark-field X-ray microscopy. These boundaries separate lattice orientation differences o...

  1. New 3DXRD results on recrystallization and grain growth

    DEFF Research Database (Denmark)

    Juul Jensen, Dorte; West, Stine; Poulsen, Stefan Othmar

    2012-01-01

    New in-situ 3DXRD results obtained since the last Rex&GG conference are presented and discussed. This includes: Documentation of the formation of nuclei with new orientations, determination of apparent activation energies for individual bulk grains during recrystallization and evolution in the 3D...

  2. Grain Boundary Segregation in Metals

    CERN Document Server

    Lejcek, Pavel

    2010-01-01

    Grain boundaries are important structural components of polycrystalline materials used in the vast majority of technical applications. Because grain boundaries form a continuous network throughout such materials, their properties may limit their practical use. One of the serious phenomena which evoke these limitations is the grain boundary segregation of impurities. It results in the loss of grain boundary cohesion and consequently, in brittle fracture of the materials. The current book deals with fundamentals of grain boundary segregation in metallic materials and its relationship to the grain boundary structure, classification and other materials properties.

  3. Grain destruction in interstellar shocks

    International Nuclear Information System (INIS)

    Seab, C.G.; Shull, J.M.

    1984-01-01

    One of the principal methods for removing grains from the Interstellar Medium is to destroy them in shock waves. Previous theoretical studies of shock destruction have generally assumed only a single size and type of grain; most do not account for the effect of the grain destruction on the structure of the shock. Earlier calculations have been improved in three ways: first, by using a ''complete'' grain model including a distribution of sizes and types of grains; second, by using a self-consistent shock structure that incorporates the changing elemental depletions as the grains are destroyed; and third, by calculating the shock-processed ultraviolet extinction curves for comparison with observations. (author)

  4. Orienting hypnosis.

    Science.gov (United States)

    Hope, Anna E; Sugarman, Laurence I

    2015-01-01

    This article presents a new frame for understanding hypnosis and its clinical applications. Despite great potential to transform health and care, hypnosis research and clinical integration is impaired in part by centuries of misrepresentation and ignorance about its demonstrated efficacy. The authors contend that advances in the field are primarily encumbered by the lack of distinct boundaries and definitions. Here, hypnosis, trance, and mind are all redefined and grounded in biological, neurological, and psychological phenomena. Solutions are proposed for boundary and language problems associated with hypnosis. The biological role of novelty stimulating an orienting response that, in turn, potentiates systemic plasticity forms the basis for trance. Hypnosis is merely the skill set that perpetuates and influences trance. This formulation meshes with many aspects of Milton Erickson's legacy and Ernest Rossi's recent theory of mind and health. Implications of this hypothesis for clinical skills, professional training, and research are discussed.

  5. Oriented Approach

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Moghimi

    2013-12-01

    Full Text Available Promoting productivity is one of the goals of usinginformation technology in organizations. The purpose of this research isexamining the impact of IT on organizational productivity andrecognizing its mechanisms based on process-oriented approach. For thisend, by reviewing the literature of the subject a number of impacts of ITon organizational processes were identified. Then, through interviewswith IT experts, seven main factors were selected and presented in aconceptual model. This model was tested through a questionnaire in 148industrial companies. Data analysis shows that impact of IT onproductivity can be included in the eight major categories: Increasing ofthe Automation, Tracking, Communication, Improvement, Flexibility,Analytic, Coordination and Monitoring in organizational processes.Finally, to improve the impact of information technology onorganizational productivity, some suggestions are presented.

  6. Dust grain charging in a wake of other grains

    International Nuclear Information System (INIS)

    Miloch, W. J.; Block, D.

    2012-01-01

    The charging of dust grain in the wake of another grains in sonic and supersonic collisionless plasma flows is studied by numerical simulations. We consider two grains aligned with the flow, as well as dust chains and multiple grain arrangements. It is found that the dust charge depends significantly on the flow speed, distance between the grains, and the grain arrangement. For two and three grains aligned, the charges on downstream grains depend linearly on the flow velocity and intergrain distance. The simulations are carried out with DiP3D, a three dimensional particle-in-cell code with both electrons and ions represented as numerical particles [W. J. Miloch et al., Phys. Plasmas 17, 103703 (2010)].

  7. Investigation of grain subdivision at very low plastic strains in a magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Hong, X. [Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Godfrey, A., E-mail: awgodfrey@mail.tsinghua.edu.cn [Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Zhang, C.L.; Liu, W. [Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Chapuis, A. [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2017-05-02

    In-situ tensile loading combined with electron backscatter diffraction (EBSD) measurements has been used to investigate the plastic deformation of a magnesium alloy. A novel EBSD mapping is presented, based on construction of maps showing the rotation axis component in the sample coordinate frame of the misorientation from each pixel to the average grain orientation in the deformed sample. Using this mapping it is shown that the pattern of grain subdivision, even at very low plastic strains, can be revealed simultaneously in a large number of grains. In addition, it is demonstrated how maps of the rotation axis corresponding to the misorientation between each pixel and the initial grain orientation provide complimentary information directly useful for crystal plasticity analysis. A detailed slip system analysis shows that the grain subdivision can be accounted for according to the low energy dislocation structures (LEDS) model of work-hardening by differences in the slip amplitudes within different parts of each grain.

  8. MESOSCALE SIMULATIONS OF MICROSTRUCTURE AND TEXTURE EVOLUTION DURING DEFORMATION OF COLUMNAR GRAINS

    International Nuclear Information System (INIS)

    Sarma, G.

    2001-01-01

    In recent years, microstructure evolution in metals during deformation processing has been modeled at the mesoscale by combining the finite element method to discretize the individual grains with crystal plasticity to provide the constitutive relations. This approach allows the simulations to capture the heterogeneous nature of grain deformations due to interactions with neighboring grains. The application of this approach to study the deformations of columnar grains present in solidification microstructures is described. The microstructures are deformed in simple compression, assuming the easy growth direction of the columnar grains to be parallel to the compression axis in one case, and perpendicular in the other. These deformations are similar to those experienced by the columnar zones of a large cast billet when processed by upsetting and drawing, respectively. The simulations show that there is a significant influence of the initial microstructure orientation relative to the loading axis on the resulting changes in grain shape and orientation

  9. Heat transfer rate within non-spherical thick grains

    Directory of Open Access Journals (Sweden)

    Huchet Florian

    2017-01-01

    Full Text Available The prediction of the internal heat conduction into non-spherical thick grains constitutes a significant issue for physical modeling of a large variety of application involving convective exchanges between fluid and grains. In that context, the present paper deals with heat rate measurements of various sizes of particles, the thermal sensors being located at the interface fluid/grain and into the granular materials. Their shape is designed as cuboid in order to control the surface exchanges. In enclosed coneshaped apparatus, a sharp temperature gradient is ensured from a hot source releasing the air stream temperature equal to about 400°C. Two orientations of grain related to the air stream are considered: diagonally and straight arrangements. The thermal diffusivity of the grains and the Biot numbers are estimated from an analytical solution established for slab. The thermal kinetics evolution is correlated to the sample granular mass and its orientation dependency is demonstrated. Consequently, a generalized scaling law is proposed which is funded from the effective area of the heat transfer at the grain-scale, the dimensionless time being defined from the calculated diffusional coefficients.

  10. Heat transfer rate within non-spherical thick grains

    Science.gov (United States)

    Huchet, Florian; Richard, Patrick; Joniot, Jules; Le Guen, Laurédan

    2017-06-01

    The prediction of the internal heat conduction into non-spherical thick grains constitutes a significant issue for physical modeling of a large variety of application involving convective exchanges between fluid and grains. In that context, the present paper deals with heat rate measurements of various sizes of particles, the thermal sensors being located at the interface fluid/grain and into the granular materials. Their shape is designed as cuboid in order to control the surface exchanges. In enclosed coneshaped apparatus, a sharp temperature gradient is ensured from a hot source releasing the air stream temperature equal to about 400°C. Two orientations of grain related to the air stream are considered: diagonally and straight arrangements. The thermal diffusivity of the grains and the Biot numbers are estimated from an analytical solution established for slab. The thermal kinetics evolution is correlated to the sample granular mass and its orientation dependency is demonstrated. Consequently, a generalized scaling law is proposed which is funded from the effective area of the heat transfer at the grain-scale, the dimensionless time being defined from the calculated diffusional coefficients.

  11. EDITORIAL: Optical orientation Optical orientation

    Science.gov (United States)

    SAME ADDRESS *, Yuri; Landwehr, Gottfried

    2008-11-01

    priority of the discovery in the literature, which was partly caused by the existence of the Iron Curtain. I had already enjoyed contact with Boris in the 1980s when the two volumes of Landau Level Spectroscopy were being prepared [2]. He was one of the pioneers of magneto-optics in semiconductors. In the 1950s the band structure of germanium and silicon was investigated by magneto-optical methods, mainly in the United States. No excitonic effects were observed and the band structure parameters were determined without taking account of excitons. However, working with cuprous oxide, which is a direct semiconductor with a relative large energy gap, Zakharchenya and his co-worker Seysan showed that in order to obtain correct band structure parameters, it is necessary to take excitons into account [3]. About 1970 Boris started work on optical orientation. Early work by Hanle in Germany in the 1920s on the depolarization of luminescence in mercury vapour by a transverse magnetic field was not appreciated for a long time. Only in the late 1940s did Kastler and co-workers in Paris begin a systematic study of optical pumping, which led to the award of a Nobel prize. The ideas of optical pumping were first applied by Georges Lampel to solid state physics in 1968. He demonstrated optical orientation of free carriers in silicon. The detection method was nuclear magnetic resonance; optically oriented free electrons dynamically polarized the 29Si nuclei of the host lattice. The first optical detection of spin orientation was demonstrated by with the III-V semiconductor GaSb by Parsons. Due to the various interaction mechanisms of spins with their environment, the effects occurring in semiconductors are naturally more complex than those in atoms. Optical detection is now the preferred method to detect spin alignment in semiconductors. The orientation of spins in crystals pumped with circularly polarized light is deduced from the degree of circular polarization of the recombination

  12. A single grain approach applied to modelling recrystallization kinetics in a single-phase metal

    NARCIS (Netherlands)

    Chen, S.P.; Zwaag, van der S.

    2004-01-01

    A comprehensive model for the recrystallization kinetics is proposed which incorporates both microstructure and the textural components in the deformed state. The model is based on the single-grain approach proposed previously. The influence of the as-deformed grain orientation, which affects the

  13. Experimental determination and theoretical analysis of local residual stress at grain scale

    NARCIS (Netherlands)

    Basu, Indranil; Ocelík, Václav; De Hosson, Jeff Th M.

    2017-01-01

    Grain/phase boundaries contribute significantly to build up of residual stresses, owing to varied plastic/thermal response of different grain orientations or phases during thermomechanical treatment. Hence, accurate quantification of such local scale stress gradients in commercial components is

  14. Biaxial magnetic grain alignment

    International Nuclear Information System (INIS)

    Staines, M.; Genoud, J.-Y.; Mawdsley, A.; Manojlovic, V.

    2000-01-01

    Full text: We describe a dynamic magnetic grain alignment technique which can be used to produce YBCO thick films with a high degree of biaxial texture. The technique is, however, generally applicable to preparing ceramics or composite materials from granular materials with orthorhombic or lower crystal symmetry and is therefore not restricted to superconducting applications. Because magnetic alignment is a bulk effect, textured substrates are not required, unlike epitaxial coated tape processes such as RABiTS. We have used the technique to produce thick films of Y-247 on untextured silver substrates. After processing to Y-123 the films show a clear enhancement of critical current density relative to identically prepared untextured or uniaxially textured samples. We describe procedures for preparing materials using magnetic biaxial grain alignment with the emphasis on alignment in epoxy, which can give extremely high texture. X-ray rocking curves with FWHM of as little as 1-2 degrees have been measured

  15. Grain Boundary Complexions

    Science.gov (United States)

    2014-05-01

    Cantwell et al. / Acta Materialia 62 (2014) 1–48 challenging from a scientific perspective, but it can also be very technologically rewarding , given the...energy) is a competing explanation that remains to be explored. Strategies to drive the grain boundary energy toward zero have produced some success...Thompson AM, Soni KK, Chan HM, Harmer MP, Williams DB, Chabala JM, et al. J Am Ceram Soc 1997;80:373. [172] Behera SK. PhD dissertation, Materials Science

  16. Predictive coarse-graining

    Energy Technology Data Exchange (ETDEWEB)

    Schöberl, Markus, E-mail: m.schoeberl@tum.de [Continuum Mechanics Group, Technical University of Munich, Boltzmannstraße 15, 85748 Garching (Germany); Zabaras, Nicholas [Institute for Advanced Study, Technical University of Munich, Lichtenbergstraße 2a, 85748 Garching (Germany); Department of Aerospace and Mechanical Engineering, University of Notre Dame, 365 Fitzpatrick Hall, Notre Dame, IN 46556 (United States); Koutsourelakis, Phaedon-Stelios [Continuum Mechanics Group, Technical University of Munich, Boltzmannstraße 15, 85748 Garching (Germany)

    2017-03-15

    We propose a data-driven, coarse-graining formulation in the context of equilibrium statistical mechanics. In contrast to existing techniques which are based on a fine-to-coarse map, we adopt the opposite strategy by prescribing a probabilistic coarse-to-fine map. This corresponds to a directed probabilistic model where the coarse variables play the role of latent generators of the fine scale (all-atom) data. From an information-theoretic perspective, the framework proposed provides an improvement upon the relative entropy method and is capable of quantifying the uncertainty due to the information loss that unavoidably takes place during the coarse-graining process. Furthermore, it can be readily extended to a fully Bayesian model where various sources of uncertainties are reflected in the posterior of the model parameters. The latter can be used to produce not only point estimates of fine-scale reconstructions or macroscopic observables, but more importantly, predictive posterior distributions on these quantities. Predictive posterior distributions reflect the confidence of the model as a function of the amount of data and the level of coarse-graining. The issues of model complexity and model selection are seamlessly addressed by employing a hierarchical prior that favors the discovery of sparse solutions, revealing the most prominent features in the coarse-grained model. A flexible and parallelizable Monte Carlo – Expectation–Maximization (MC-EM) scheme is proposed for carrying out inference and learning tasks. A comparative assessment of the proposed methodology is presented for a lattice spin system and the SPC/E water model.

  17. Grain alcohol study: summary

    Energy Technology Data Exchange (ETDEWEB)

    The study has concentrated upon a detailed examination of all considerations involved in the production, use, and marketing of ethyl alcohol (ethanol) as produced from the fermentation of agricultural grains. Each parameter was examined in the light of current energy markets and trends; new sources and technological, and processes for fermentation, the capability of the agricultural industry to support fermentation demand; the optimizaton of value of agricultural crops; and the efficiencies of combining related industries. Ahydrous (200 proof) ethanol makes an excellent blending component for all present automotive fuels and an excellent octane additive for unleaded fuels in proportions up to 35% without requiring modifications to current engines. There is no difference between ethanol produced by fermentation and ethanol produced synthetically from petroleum. The decision to produce ethanol one way or the other is purely economic. The agricultural industry can support a major expansion in the fermentation industry. The residue (distillers grains) from the fermentation of corn for ethanol is an excellent and economical feed for livestock and poultry. A reliable supply of distillers grain can assist in making the large beef feedlot operations more economically viable. The source materials, fuels, products and by-products of an ethanol plant, beef feedlot, gas biodigester plant, municipal waste recovery plant and a steam generated electrical plant are interrelated and mutually beneficial for energy efficiencies and economic gains when co-located. The study concludes that the establishment of such agricultural- environment industrial energy complexes, would provide a broad range of significant benefits to Indiana.

  18. Grain alcohol study: summary

    Energy Technology Data Exchange (ETDEWEB)

    The study has concentrated upon a detailed examination of all considerations involved in the production, use, and marketing of ethyl alcohol (Ethanol) as produced from the fermentation of agricultural grains. Each parameter was examined in the light of current energy markets and trends; new sources and technological, and processes for fermentation, the capability of the agricultural industry to support fermentaton demand; the optimization of value of agricultureal crops; and the efficiencies of combining related industries. Anhydrous (200 proof) ethanol makes an excellent blending component for all present automotive fuels and an excellent octane additive for unleaded fuels in proportions up to 35% without requiring modifications to current engines. There is no difference between ethanol produced by fermentation and ethanol produced synthetically from petroleum. The decision to produce ethanol one way or the other is purely economic. The agricultural industry can support a major expansion in the fermentation industry. The residue (distillers grains) from the fermentation of corn for ethanol is an excellent and economical feed for livestock and poultry. A reliable supply of distillers grains can assist in making the large beef feedlot operations more economically viable. The source materials, fuels, products and by-products of an ethanol plant, beef feedlot, gas biodigester plant, municipal waste recovery plant and a steam generated electrical plant are interrelated and mutually beneficial for energy efficiencies and economic gains when co-located. The study concludes that the establishment of such agricultural-environment industrial energy complexes, would provide a broad range of significant benefits to Indiana.

  19. Grain preservation in SSSR

    International Nuclear Information System (INIS)

    Trisviatski, L.A.

    1973-01-01

    First the importance of cereals collected in the S.S.S.R., the reason why the government had to put in practice a storage chain, composed of large capacity store houses (200 000 metric tonnes, or more) is reminded. When climatic conditions result in wet harvested grains, cereals are dried either in state enterprise dryers (32 to 50 tonnes/hour) or in kolkhozes' dryers (2 to 16 tonnes/hour). A new type of drying with recycling, has been developped, economizing 10 to 15 p. 100. Then the possibilities offered by the technique of partial drying of very wet grains are studied and the preservation processes using fresh ventilation, or hot ventilation with drying effect are described. The question of silage of wet grains destined to animal consumption is then examined as well as preservation by sodium pyrosulfide; the use of propionic acid, little developped in SSSR, is studied now, just as storage with inert gas. The struggle technics against insects, either with chemical agents, or with irradiation are described. Finally the modalities of technicians formation, specialized in preservation, are discussed [fr

  20. Validation of Reported Whole-Grain Intake from a Web-Based Dietary Record against Plasma Alkylresorcinol Concentrations in 8- to 11-Year-Olds Participating in a Randomized Controlled Trial

    DEFF Research Database (Denmark)

    Biltoft-Jensen, Anja Pia; Damsgaard, Camilla T.; W. Andersen, Elisabeth

    2016-01-01

    meal × 3 mo crossover trial. Reported WG intake and plasma AR concentrations were compared when children ate their usual bread-based lunch (UBL) and when served a hot lunch meal (HLM). Correlations and cross-classification were used to rank subjects according to intake. The intraclass correlation......BACKGROUND: Whole-grain (WG) intake is important for human health, but accurate intake estimation is challenging. Use of a biomarker for WG intake provides a possible way to validate dietary assessment methods. OBJECTIVE: Our aim was to validate WG intake from 2 diets reported by children, using...... plasma alkylresorcinol (AR) concentrations, and to investigate the 3-mo reproducibility of AR concentrations and reported WG intake. METHODS: AR concentrations were analyzed in fasting blood plasma samples, and WG intake was estimated in a 7-d web-based diary by 750 participants aged 8-11 y in a 2 school...

  1. Origins of amorphous interstellar grains

    International Nuclear Information System (INIS)

    Hasegawa, H.

    1984-01-01

    The existence of amorphous interstellar grains has been suggested from infrared observations. Some carbon stars show the far infrared emission with a lambda -1 wavelength dependence. Far infrared emission supposed to be due to silicate grains often show the lambda -1 wavelength dependence. Mid infrared spectra around 10 μm have broad structure. These may be due to the amorphous silicate grains. The condition that the condensed grains from the cosmic gas are amorphous is discussed. (author)

  2. Photoelectric charging of dust grains

    International Nuclear Information System (INIS)

    Ignatov, A. M.

    2009-01-01

    Photoemission from the surface of a dust grain in vacuum is considered. It is shown that the cutoff in the energy spectrum of emitted electrons leads to the formation of a steady-state electron cloud. The equation describing the distribution of the electric potential in the vicinity of a dust grain is solved numerically. The dust grain charge is found as a function of the grain size.

  3. Orienteering Club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    Course d'orientation Le coup d’envoi de la coupe genevoise a été donné samedi 31 août dans les bois de Combe Froide à Prémanon. Plus de 150 coureurs avaient fait le déplacement. Les parcours facile court, facile moyen et technique court ont été remportés par des coureurs du club O’Jura - Ulysse Dannecker, Léo Lonchampt, Franck Lonchampt, le technique moyen par Pekka Marti du club Ol Biel Seeland et le technique long par Térence Risse du CA Rosé – également membre de l’équipe nationale suisse des moins de 20 ans. Pour le club du CERN, les meilleures résultats ont été obtenus pas Emese Szunyog sur technique court et Marie Vuitton sur technique moyen avec une 4e place. La prochaine course aura lieu samedi 14 septembre à La Faucille. Le club propose aussi...

  4. Orienteering club

    CERN Multimedia

    Club d'orientation

    2014-01-01

    Course d'orientation Finale de la coupe d’automne La dernière épreuve de la coupe d’automne organisée par le club s’est déroulée ce samedi 1er novembre avec une course type «one-man-relay» dans la forêt de Trelex (Vd). Les concurrents des circuits techniques devaient parcourir trois boucles et ceux des circuits «faciles» deux boucles, avec changements de carte. Le parcours technique long a été remporté par un membre du club, Berni Wehrle. A l’issue de cette course, le Président du club, L. Jirden annonçait le classement général de la coupe d’automne, basé sur les 6 meilleurs résultats de la saison : Circuit technique long : 1er Juerg Niggli (O’Jura), 2e Berni Wehrle, 3e Beat Mueller. Circuit technique moyen : 1er Laurent Merat (O&r...

  5. Orienteering club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    Course d'orientation Finale de la coupe genevoise Rapide et méthodique, voilà les qualités dont il fallait faire preuve pour remporter la dernière étape de la coupe organisée par le club du CERN dans les bois de Monteret. Il s’agissait d’une course au score où chaque concurrent disposait d’un temps imparti pour poinçonner le maximum de balises. Le parcours technique a été remporté par Tomas Shellman et le parcours facile par Victor Dannecker. Cette dernière étape était aussi décisive pour la désignation des lauréats de la coupe genevoise de printemps. Les résultats officiels étaient donnés par le président du club, L. Jirden : Circuit Technique Long : Berni Wehrle, Bruno Barge, Edvins Reisons Circuit Technique Moyen : J.-Bernard Zosso, ...

  6. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2011-01-01

    Course d'orientation Avec la CO en nocturne organisée par le club du CERN vendredi 14 octobre au stade des Eveaux (Ge), et la CO à Savigny (Vd) proposée par le club de Lausanne-Jorat le lendemain, les étapes de la coupe genevoise d’automne s’enchainent rapidement. Il ne reste plus que 3 rendez-vous pour boucler la saison. Les premières places devraient certainement se jouer entre des membres du club du CERN, du O’Jura ou de Lausanne-Jorat. La prochaine course du club est programmée pour samedi 22 octobre à Pomier, près de Cruseilles. L’accueil se fera à partir de 12h30 et les départs s’échelonneront de 13h à 15h. * * * * * * * Nouvelle belle victoire samedi 8 octobre à Saint Cergue du jeune finlandais Ville Keskisaari (COLJ) en 50:56 devant Jürg Niggli (O’Jura) en 1:03:32, et Alexandre...

  7. Orienteering Club

    CERN Document Server

    Club d'orientation

    2013-01-01

    De jour comme de nuit Les amateurs de course d’orientation ont pu s’en donner à cœur joie ce week-end puisqu’ils avaient la possibilité de courir sur deux épreuves en moins de 24 heures. En effet, le club du CERN organisait une course de nuit aux Evaux et la 7e étape de la coupe genevoise se tenait samedi après-midi dans les bois du Grand Jorat à Savigny. Les vainqueurs pour chaque course sont : Technique long CO de nuit: Julien Charlemagne, SOS Sallanches CO samedi: Philipp Khlebnikov, ANCO   Technique moyen CO de nuit: Céline Zosso, CO CERN CO samedi: Pavel Khlebnikov, ANCO Technique court CO de nuit: Colas Ginztburger, SOS Sallanches CO samedi: Victor Kuznetsov, COLJ Lausannne Facile moyen CO de nuit: Gaëtan Rickenbacher, CO CERN CO samedi: Tamas Szoke   Facile court CO de nuit:Oriane Rickenbacher, CO CERN CO samedi: Katya Kuznetsov...

  8. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2015-01-01

    Course orientation Finale de la coupe genevoise La série des courses de printemps s’est achevée samedi dernier dans les bois de Bonmont (Vaud) avec une épreuve «one-man-relay» organisée par le club. Le vainqueur du parcours technique  long, Yann Locatelli (Club de Chambéry Savoie) a réalisé les deux boucles comportant 24 balises avec presque 6 minutes d’avance sur le second concurrent Domenico Lepori (Club CARE Vevey). Cette dernière étape était aussi décisive pour la désignation des lauréats de la coupe genevoise de printemps, en comptabilisant les 6 meilleurs résultats sur les 10 épreuves. Le podium officiel était donné par le président du club, L. Jirden, qui profitait de l’occasion pour remercier tous les participants et également tous les...

  9. Orienteering Club

    CERN Multimedia

    CLUB D'ORIENTATION

    2013-01-01

    Calendrier de la coupe d’automne Le Club d’orientation du CERN, en partenariat avec d’autres clubs de la région, vous propose, pour cette nouvelle coupe d’automne genevoise, une série de 10 courses. Le club du O’Jura donnera le coup d’envoi le samedi 31 août. Les courses s’enchaîneront selon le calendrier suivant : Samedi 31 août : Prémanon (39) - longue distance Samedi 14 septembre : La Faucille (01) - longue distance Samedi 21 septembre : Saint Cergue (VD) - longue distance Samedi 28 septembre : Ballens (VD) - relais Samedi 5 octobre : La Pile (VD) - longue distance Vendredi 11 octobre : Les Evaux (GE) - nocturne Samedi 12 octobre : Grand Jorat, Savigny (VD) - longue distance Samedi 19 octobre : Terrasses de Genève (74) - longue distance Samedi 26 octobre : Prémanon (39) - longue distance Samedi 2 novembre : Bois Tollot (GE) - score - Finale Les &a...

  10. Orienteering club

    CERN Multimedia

    Club d'orientation

    2014-01-01

    Course d'orientation C’est sous un beau soleil samedi 4 octobre que s’est déroulée la 6e étape de la Coupe genevoise d’automne organisée par le club. Plus d’une centaine de concurrents provenant de 7 clubs de CO avaient fait le déplacement pour courir sur un des cinq parcours proposés dans les bois de Trélex-Génolier (VD). Le podium est le suivant : Technique long (5,9 km, 19 postes) : 1er Jurg Niggli, O’Jura (1:00:02); 2e Berni Wehrle, CO CERN (1:06:44); 3e Konrad Ehrbar, COLJ (1:07:08) Technique moyen (4,8 km, 18 postes) : 1er Christophe Vuitton, CO CERN (54:25); 2e J.B. Zosso, CO CERN (1:01:19); 3e Jeremy Wichoud, COLJ (1:06:21) Technique court (3,8 km, 14 postes) : 1er Julien Vuitton, CO CERN (36:19); 2e Vladimir Kuznetsov, COLJ (48:47); 3e Natalia Niggli, O’Jura (50:38) Facile moyen (3,2 km, 11 postes) : 1ère Alina Niggli, O&...

  11. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2012-01-01

    Relais inter-club/Challenge Carlo Milan Samedi dernier, lors de l’épreuve de course d’orientation organisée par le club du O’Jura, le moteur de la discipline était l’esprit d’équipe, puisqu’il était question d’un relais inter-club avec le Challenge Carlo Milan. Les clubs avaient aligné leurs coureurs soit sur le relais technique (trois participants) soit sur le relais facile (deux participants). Côté O’Jura, il fallait noter la participation de François Gonon, champion du monde 2011, côté club du CERN, Marie et Gaëtan Vuitton, jeunes espoirs du club, devaient préparer la piste pour lancer le dernier relayeur. Côté Lausanne-Jorat, il fallait compter sur le très jeune Viktor Kuznetsov. Les 31 équipes engagées n’ont pas m&ea...

  12. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2012-01-01

     Finale de la coupe de printemps   La dernière course d’orientation comptant pour la Coupe de printemps a eu lieu samedi dernier dans le village des Rousses et vers le Fort. Il s’agissait d’un sprint organisé par le club O’Jura. Les temps de course ont avoisiné les 20 minutes que ce soit pour le parcours technique moyen ou technique long. Tous les habitués étaient au rendez-vous pour venir consolider ou améliorer leur place au classement. A l’issue de cette course, le classement général de la Coupe de printemps prenant en compte les 6 meilleurs résultats des 9 courses était établi et les lauréats de chaque catégorie sont les suivants: Circuit technique long : 1er Berni Wehrle, 2e Bruno Barge, 3e Edvins Reisons. Circuit technique moyen : 1er Jean-Bernard Zosso, 2e Cédric Wehrl&...

  13. Orienteering club

    CERN Multimedia

    Club d'orientation

    2010-01-01

    COURSE D’ORIENTATION  De La Rippe à Sauvabellin, la coupe genevoise continue ! Le rendez-vous était donné samedi 8 mai aux amateurs de course d’orientation dans les bois de La Rippe (Canton de Vaud). Cette 6e épreuve était organisée par le Club Satus Grutli de Genève. Il est dommage que les participants n’aient pas été aussi nombreux que lors des dernières courses, les Championnats de France des clubs à Dijon ayant certainement retenus plus d’un compétiteur. La première place est revenue à : – Technique long : Berni Wehrle – Technique moyen : Jean-Bernard Zosso – Technique court : Berni Wehrle – Facile moyen : Peter Troscanyi – Facile court : Claire Droz. Il ne restera plus que deux épreuves ...

  14. Orienteering club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    Courses d’orientation Samedi 20 avril, les organisateurs du Club de CO du CERN ont accueilli au Mont Mourex 70 participants qui n’ont pas hésité à venir malgré la forte bise. Berni Wehrle du CO CERN s’est octroyé la première place en 1:04:49 sur le parcours technique long devant Pyry Kettunen du Saynso Juankoski en 1:06:52, la 3e place revenant à Bruno Barge, CO CERN, à 7 secondes. Les autres parcours ont été remportés par : Technique moyen : 1er Jacques Moisset, Chamonix (47:44), 2e Yves Rousselot, Balise 25 Besançon (57:16), 3e Jean-Bernard Zosso, CO CERN (59:28). Technique court : 1er Victor Kuznetsov, COLJ (51:53), 2e Pierrick Collet, CO CERN (1:12:52), 3e Dominique Balay, CO CERN (1:16:04). Pour les parcours facile moyen et facile court, Ralf Nardini et Léa Nicolas, tous deux du CO CERN, terminaient respectivement premier. Voi...

  15. Storing Peanuts in Grain Bags

    Science.gov (United States)

    A study was executed to determine the potential of storing farmers stock peanuts and shelled peanuts for crushing in hermetically sealed grain bags. The objectives of the study were to evaluate equipment for loading and unloading the grain bags, the capacity of the grain bags, and the changes in qu...

  16. Effectiveness of a combination of cognitive behavioral therapy and task-oriented balance training in reducing the fear of falling in patients with chronic stroke: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Liu, Tai-Wa; Ng, Gabriel Y F; Ng, Shamay S M

    2018-03-07

    The consequences of falls are devastating for patients with stroke. Balance problems and fear of falling are two major challenges, and recent systematic reviews have revealed that habitual physical exercise training alone cannot reduce the occurrence of falls in stroke survivors. However, recent trials with community-dwelling healthy older adults yielded the promising result that interventions with a cognitive behavioral therapy (CBT) component can simultaneously promote balance and reduce the fear of falling. Therefore, the aim of the proposed clinical trial is to evaluate the effectiveness of a combination of CBT and task-oriented balance training (TOBT) in promoting subjective balance confidence, and thereby reducing fear-avoidance behavior, improving balance ability, reducing fall risk, and promoting independent living, community reintegration, and health-related quality of life of patients with stroke. The study will constitute a placebo-controlled single-blind parallel-group randomized controlled trial in which patients are assessed immediately, at 3 months, and at 12 months. The selected participants will be randomly allocated into one of two parallel groups (the experimental group and the control group) with a 1:1 ratio. Both groups will receive 45 min of TOBT twice per week for 8 weeks. In addition, the experimental group will receive a 45-min CBT-based group intervention, and the control group will receive 45 min of general health education (GHE) twice per week for 8 weeks. The primary outcome measure is subjective balance confidence. The secondary outcome measures are fear-avoidance behavior, balance ability, fall risk, level of activities of daily living, community reintegration, and health-related quality of life. The proposed clinical trial will compare the effectiveness of CBT combined with TOBT and GHE combined with TOBT in promoting subjective balance confidence among chronic stroke patients. We hope our results will provide evidence of a safe

  17. Light absorption and scattering by aggregates: Application to black carbon and snow grains

    International Nuclear Information System (INIS)

    Liou, K.N.; Takano, Y.; Yang, P.

    2011-01-01

    A geometric-optics surface-wave approach has been developed for the computation of light absorption and scattering by nonspherical particles for application to aggregates and snow grains with external and internal mixing structures. Aggregates with closed- (internal mixing) and open-cell configurations are constructed by means of stochastic procedures using homogeneous and core-shell spheres with smooth or rough surfaces as building blocks. The complex aggregate shape and composition can be accounted for by using the hit-and-miss Monte Carlo geometric photon tracing method. We develop an integral expression for diffraction by randomly oriented aggregates based on Babinet's principle and a photon-number weighted geometric cross section. With reference to surface-wave contributions originally developed for spheres, we introduce a nonspherical correction factor using a non-dimensional volume parameter such that it is 1 for spheres and 0 for elongated particles. The extinction efficiency, single-scattering albedo, and asymmetry factor results for randomly oriented columns and plates compare reasonably well with those determined from the finite-difference time domain (FDTD) and the discrete dipole approximation (DDA) computer codes for size parameters up to about 20. The present theoretical approach covers all size ranges and is particularly attractive from the perspective of efficient light absorption and scattering calculations for complex particle shape and inhomogeneous composition. We show that under the condition of equal volume and mass, the closed-cell configuration has larger absorption than its open-cell counterpart for both ballistic and diffusion-limited aggregates. Because of stronger absorption in the closed-cell case, most of the scattered energy is confined to forward directions, leading to a larger asymmetry factor than the open-cell case. Additionally, light absorption for randomly oriented snowflakes is similar to that of their spherical counterparts

  18. On the role of the grain size in the magnetic behavior of sintered permanent magnets

    Science.gov (United States)

    Efthimiadis, K. G.; Ntallis, N.

    2018-02-01

    In this work the finite elements method is used to simulate, by micromagnetic modeling, the magnetic behavior of sintered anisotropic magnets. Hysteresis loops were simulated for different grain sizes in an oriented multigrain sample. By keeping out other parameters that contribute to the magnetic microstructure, such as the sample size, the grain morphology and the grain boundaries mismatch, it has been found that the grain size affects the magnetic properties only if the grains are exchange-decoupled. In this case, as the grain size decreases, a decrease in the nucleation field of a reverse magnetic domain is observed and an increase in the coercive field due to the pinning of the magnetic domain walls at the grain boundaries.

  19. Orientation dependent fracture behavior of nanotwinned copper

    Energy Technology Data Exchange (ETDEWEB)

    Kobler, Aaron, E-mail: aaron.kobler@kit.edu; Hahn, Horst, E-mail: ahodge@usc.edu, E-mail: horst.hahn@kit.edu, E-mail: christian.kuebel@kit.edu [Technische Universität Darmstadt (TUD), KIT-TUD Joint Research Laboratory Nanomaterials, 64287 Darmstadt (Germany); Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Hodge, Andrea M., E-mail: ahodge@usc.edu, E-mail: horst.hahn@kit.edu, E-mail: christian.kuebel@kit.edu [University of Southern California (USC), Department of Aerospace and Mechanical Engineering, Los Angeles, California 90089-1453 (United States); Kübel, Christian, E-mail: ahodge@usc.edu, E-mail: horst.hahn@kit.edu, E-mail: christian.kuebel@kit.edu [Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2015-06-29

    Columnar grown nanotwinned Cu was tensile tested in-situ inside the TEM in combination with automated crystal orientation mapping scanning transmission electron microscopy to investigate the active deformation mechanisms present in this material. Two tensile directions were applied, one parallel to the twin boundaries and the other perpendicular to the twin boundaries. In case of tensile testing perpendicular to the twin boundaries, the material deformed by detwinning and the formation of new grains, whereas in the parallel case, no new grains were formed and the fracture happened along the twin boundaries and a boundary that has formed during the deformation.

  20. Orientation dependent fracture behavior of nanotwinned copper

    International Nuclear Information System (INIS)

    Kobler, Aaron; Hahn, Horst; Hodge, Andrea M.; Kübel, Christian

    2015-01-01

    Columnar grown nanotwinned Cu was tensile tested in-situ inside the TEM in combination with automated crystal orientation mapping scanning transmission electron microscopy to investigate the active deformation mechanisms present in this material. Two tensile directions were applied, one parallel to the twin boundaries and the other perpendicular to the twin boundaries. In case of tensile testing perpendicular to the twin boundaries, the material deformed by detwinning and the formation of new grains, whereas in the parallel case, no new grains were formed and the fracture happened along the twin boundaries and a boundary that has formed during the deformation

  1. Effects of grain-producing cover crops on rice grain yield in Cabo Delgado, Mozambique

    Directory of Open Access Journals (Sweden)

    Adriano Stephan Nascente

    Full Text Available ABSTRACT Besides providing benefits to the environment such as soil protection, release of nutrients, soil moisture maintenance, and weed control, cover crops can increase food production for grain production. The aim of this study was to evaluate the production of biomass and grain cover crops (and its respective effects on soil chemical and physical attributes, yield components, and grain yield of rice in Mozambique. The study was conducted in two sites located in the province of Cabo Delgado, in Mozambique. The experimental design was a randomized block in a 2 × 6 factorial, with four repetitions. Treatments were carried out in two locations (Cuaia and Nambaua with six cover crops: Millet (Pennisetum glaucum L.; namarra bean (Lablab purpureus (L. Sweet, velvet beans (Mucuna pruriens L., oloco beans (Vigna radiata (L. R. Wilczek, cowpea (Vigna unguiculata L., and fallow. Cover crops provided similar changes in chemical and physical properties of the soil. Lablab purpureus, Vigna unguiculata, and Mucuna pruriens produced the highest dry matter biomass. Vigna unguiculada produced the highest amount of grains. Rice grain yields were similar under all cover crops and higher in Cuaia than Nambaua.

  2. Sexual Orientation (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Sexual Orientation KidsHealth / For Parents / Sexual Orientation What's in this ... orientation is part of that process. What Is Sexual Orientation? The term sexual orientation refers to the gender ( ...

  3. Effect of Strain Restored Energy on Abnormal Grain Growth in Mg Alloy Simulated by Phase Field Methods

    Science.gov (United States)

    Wu, Yan; Huang, Yuan-yuan

    2018-03-01

    Abnormal grain growth of single phase AZ31 Mg alloy in the spatio-temporal process has been simulated by phase field models, and the influencing factors of abnormal grain growth are studied in order to find the ways to control secondary recrystallization in the microstructure. The study aims to find out the mechanisms for abnormal grain growth in real alloys. It is shown from the simulated results that the abnormal grain growth can be controlled by the strain restored energy. Secondary recrystallization after an annealing treatment can be induced if there are grains of a certain orientation in the microstructure with local high restored energy. However, if the value of the local restored energy at a certain grain orientation is not greater than 1.1E 0, there may be no abnormal grain growth in the microstructure.

  4. A spectral analysis of rice grains

    International Nuclear Information System (INIS)

    McIlvaine, M.S.; Cua, F.T.; Navarro, E.F.

    1976-06-01

    With the advent of extensive nuclear testing and the development and use of highly potent pesticides and fertilizers, the hazardous threats of radioactive contamination due to fallout and to the absorption of pesticide residues have been given due consideration. Among the many forms of life exposed to these threats are food crops and among these is rice. Several rice grain samples - Japanese rice samples ''A'' and ''B'' submitted by the National Grains Authority (NGA) for analysis, random samples of rice being sold to the public at local markets, and ''black rice'' which were picked from along the shores of a Mindoro town were subjected to spectral analysis. Results revealed the presence of trace elements normally found in plants, such as; K-42, I-124, Cl-38, Na-24, Br-82, and Mn-56. No mercury was detected in the sample specimen analyzed

  5. Grain yield stability of early maize genotypes

    Directory of Open Access Journals (Sweden)

    Chitra Bahadur Kunwar

    2016-12-01

    Full Text Available The objective of this study was to estimate grain yield stability of early maize genotypes. Five early maize genotypes namely Pool-17, Arun1EV, Arun-4, Arun-2 and Farmer’s variety were evaluated using Randomized Complete Block Design along with three replications at four different locations namely Rampur, Rajahar, Pakhribas and Kabre districts of Nepal during summer seasons of three consecutive years from 2010 to 2012 under farmer’s fields. Genotype and genotype × environment (GGE biplot was used to identify superior genotype for grain yield and stability pattern. The genotypes Arun-1 EV and Arun-4 were better adapted for Kabre and Pakhribas where as pool-17 for Rajahar environments. The overall findings showed that Arun-1EV was more stable followed by Arun-2 therefore these two varieties can be recommended to farmers for cultivation in both environments.

  6. The role of grain size in He bubble formation: Implications for swelling resistance

    Energy Technology Data Exchange (ETDEWEB)

    El-Atwani, O., E-mail: oelatwan25@gmail.com [Drexel University, Department of Materials Science & Engineering, Philadelphia, PA (United States); Nathaniel, J.E.; Leff, A.C. [Drexel University, Department of Materials Science & Engineering, Philadelphia, PA (United States); Muntifering, B.R. [Department of Radiation Solid Interactions, Sandia National Laboratories, NM (United States); Baldwin, J.K. [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM (United States); Hattar, K. [Department of Radiation Solid Interactions, Sandia National Laboratories, NM (United States); Taheri, M.L. [Drexel University, Department of Materials Science & Engineering, Philadelphia, PA (United States)

    2017-02-15

    Nanocrystalline metals are postulated as radiation resistant materials due to their high defect and particle (e.g. Helium) sink density. Here, the performance of nanocrystalline iron films is investigated in-situ in a transmission electron microscope (TEM) using He irradiation at 700 K. Automated crystal orientation mapping is used in concert with in-situ TEM to explore the role of grain orientation and grain boundary character on bubble density trends. Bubble density as a function of three key grain size regimes is demonstrated. While the overall trend revealed an increase in bubble density up to a saturation value, grains with areas ranging from 3000 to 7500 nm{sup 2} show a scattered distribution. An extrapolated swelling resistance based on bubble size and areal density indicated that grains with sizes less than 2000 nm{sup 2} possess the greatest apparent resistance. Moreover, denuded zones are found to be independent of grain size, grain orientation, and grain boundary misorientation angle.

  7. Read/write properties of oriented longitudinal recording media

    International Nuclear Information System (INIS)

    Uesaka, Y.; Nakatani, Y.; Hayashi, N.; Fukushima, H.

    2001-01-01

    The effect of orientation on the maximum recording density including the thermal stability effect was investigated using computer simulation. The necessary head current for a highly oriented medium is at most 10% larger than that for a 2D random medium. A recording density larger than 300 Gb/in 2 can be achieved with highly oriented media with 30 nm flying height

  8. Crystallographic contribution to the formation of the columnar grain structure in cobalt films

    International Nuclear Information System (INIS)

    Hara, K.; Itoh, K.; Okamoto, K.; Hashimoto, T.

    1996-01-01

    In order to clarify the crystallographic contribution to the formation of the columnar grain structure, the geometric and crystallographic alignments of columnar grains in cobalt films were investigated on the basis of magnetic and optical measurements. The films were deposited by sputtering at an incidence angle of 45 on glass substrates heated at 332 K. The film thickness ranged from 20 to 850 nm. Above 50 nm the columnar grains align in the direction parallel to the incidence plane and form a two-degree crystallographic orientation. The packing density of columnar grains decreases with increasing thickness when the thickness exceeds 50 nm. From these results we conclude that the crystal habit appearing on column tops induces the two-degree orientation through geometric selection and aligns the selected columnar grains in the parallel direction. (orig.)

  9. Chevron defect at the intersection of grain boundaries with free surfaces in Au

    International Nuclear Information System (INIS)

    Radetic, T.; Lancon, F.; Dahmen, U.

    2002-01-01

    We have identified a new defect at the intersection between grain boundaries and surfaces in Au using atomic resolution transmission electron microscopy. At the junction line of 90 deg. tilt grain boundaries of (110)-(001) orientation with the free surface, a small segment of the grain boundary, about 1 nm in length, dissociates into a triangular region with a chevronlike stacking disorder and a distorted hcp structure. The structure and stability of these defects are confirmed by atomistic simulations, and we point out the relationship with the one-dimensional incommensurate structure of the grain boundary

  10. Structure and electronic properties of boron nitride sheet with grain boundaries

    International Nuclear Information System (INIS)

    Wang Zhiguo

    2012-01-01

    Using first-principles calculations, the structure, stability, and electronic properties of BN sheets with grain boundaries (GBs) are investigated. Two types of GBs, i.e., zigzag- and armchair-oriented GBs, are considered. Simulation results reveal that the zigzag-oriented GBs are more stable than the armchair-oriented ones. The GBs induce defect levels located within the band gap, which must be taken into account when building nanoelectronic devices.

  11. Diffraction stress analysis of thin films; investigating elastic grain interaction

    International Nuclear Information System (INIS)

    Kumar, A.

    2005-12-01

    This work is dedicated to the investigation of specimens exhibiting anisotropic microstructures (and thus macroscopic elastic anisotropy) and/or inhomogeneous microstructures, as met near surfaces and in textured materials. The following aspects are covered: (i) Analysis of specimens with direction-dependent (anisotropic) elastic grain-interaction. Elastic grain-interaction determines the distribution of stresses and strains over the (crystallographically) differently oriented grains of a mechanically stressed polycrystal and the mechanical and diffraction (X-ray) elastic constants (relating (diffraction) lattice strains to mechanical stresses). Grain interaction models that allow for anisotropic, direction-dependent grain interaction have been developed very recently. The notion 'direction-dependent' grain-interaction signifies that different grain-interaction constraints prevail along different directions in a specimen. Practical examples of direction-dependent grain interaction are the occurrence of surface anisotropy in thin films and the surface regions of bulk polycrystals and the occurrence of grain-shape (morphological) texture. In this work, for the first time, stress analyses of thin films have been performed on the basis of these newly developed grain-interaction models. It has also been demonstrated that the identification of the (dominant) source of direction-dependent grain interaction is possible. The results for the grain interaction have been discussed in the light of microstructural investigations of the specimens by microscopic techniques. (ii) Analysis of specimens with depth gradients: Diffraction stress analysis can be hindered if gradients of the stress state, the composition or the microstructure occur in the specimen under investigation, as the so-called information depth varies in the course of a traditional stress measurement: Ambiguous results are thus generally obtained. In this work, a strategy for stress measurements at fixed

  12. Transitional grain-size-sensitive flow of milky quartz aggregates

    Science.gov (United States)

    Fukuda, J. I.; Holyoke, C. W., III; Kronenberg, A. K.

    2014-12-01

    Fine-grained (~15 μm) milky quartz aggregates exhibit reversible flow strengths in triaxial compression experiments conducted at T = 800-900oC, Pc = 1.5 GPa when strain rates are sequentially decreased (typically from 10-3.5 to 10-4.5 and 10-5.5 s-1), and then returned to the original rate (10-3.5 s-1), while samples that experience grain growth at 1000oC (to 35 μm) over the same sequence of strain rates exhibit an irreversible increase in strength. Polycrystalline quartz aggregates have been synthesized from natural milky quartz powders (ground to 5 μm) by HIP methods at T = 1000oC, Pc = 1.5 GPa and t = 24 hours, resulting in dense, fine-grained aggregates of uniform water content of ~4000 ppm (H/106Si), as indicated by a broad OH absorption band at 3400 cm-1. In experiments performed at 800o and 900oC, grain sizes of the samples are essentially constant over the duration of each experiment, though grain shapes change significantly, and undulatory extinction and deformation lamellae indicate that much of the sample shortening (to 50%) is accomplished, over the four strain-rate steps, by dislocation creep. Differential stresses measured at T = 800oC decrease from 160 to 30 MPa as strain rate is reduced from 10-4.6 to 10-5.5 s-1, and a stress of 140 MPa is measured when strain rate is returned to 10-4.5 s-1. Samples deformed at 1000o and 1100oC experience normal grain growth, with grain boundary energy-driven grain-coarsening textures superposed by undulatory extinction and deformation lamellae. Differential stresses measured at 1000oC and strain rates of 10-3.6, 10-4.6, and 10-5.5 s-1 are 185, 80, and 80 MPa, respectively, while an increased flow stress of 260 MPa is measured (following ~28 hours of prior high temperature deformation and grain growth) when strain rate is returned to 10-3.6 s-1. While all samples exhibit lattice preferred orientations, the stress exponent n inferred for the fine-grained 800oC sample is 1.5 and the stress exponent of the coarse-grained

  13. Grain Flow at High Stresses

    Science.gov (United States)

    McSaveney, M. J.

    2015-12-01

    The transport mechanism of rapid long-runout rock avalanches was a hotly debated topic when I came on the scene in 1967. So how come it is still debated today? My explanation is that it is the expected outcome of peer review, poor comprehension, and technological advances outpacing intellectual advances. Why think about the problem when we can model it! So let us think about the problem. Shreve thought that rock avalanches fell upon and trapped a layer of air. What physics was he thinking about? It is how feathers and tissue papers fall. When my rock avalanches fly, they fly like unlubricated bricks using the physics of projectiles and ballistics. But the main transport mechanism is not flight. The dominant impression from watching a rock avalanche in motion is of fluid flow, as Heim described it in 1882. A rock avalanche is a very large grain flow. Bagnold studied dispersive grain flows, but why should one assume that rock avalanches are dispersive grain flows as many do. The more common grain flow type is a dense grain flow and rock avalanches are dense grain flows in which the weight can and does generate very high stresses at grain contacts. Brittle rock deforms elastically up to its compressive strength, whereupon it breaks, releasing elastic strain as transient elastic strain (seismic energy to a seismologist, acoustic energy to a physicist). Melosh and others have shown that acoustic energy can fluidize a grain mass. There is no exotic physics behind grain flow at high stress. When grains break, the released elastic strain has to go somewhere, and it goes somewhere principally by transmission though grain contacts. Depending on the state of stress at the grain contact, the contact will pass the stress or will slip at conventional values of Coulomb friction. Enough thinking! A physical model of the entire process is too big for any laboratory. So whose numerical model will do it?

  14. Highly -oriented growth of polycrystalline silicon films on glass by pulsed magnetron sputtering

    International Nuclear Information System (INIS)

    Reinig, P.; Selle, B.; Fenske, F.; Fuhs, W.; Alex, V.; Birkholz, M.

    2002-01-01

    Nominally undoped polycrystalline silicon (poly-Si) thin films were deposited on glass at 450 deg. C at high deposition rate (>100 nm/min) by pulsed dc magnetron sputtering. The pulse frequency was found to have a significant influence on the preferred grain orientation. The x-ray diffraction pattern exhibits a strong enhancement of the (400) reflex with increasing pulse frequency. The quantitative evaluation reveals that over 90% of the grains are oriented. The observed change in preferred grain orientation in poly-Si films at low temperatures is associated with concurrent ion bombardment of the growing film

  15. Grain dust and the lungs.

    Science.gov (United States)

    Chan-Yeung, M.; Ashley, M. J.; Grzybowski, S.

    1978-01-01

    Grain dust is composed of a large number of materials, including various types of grain and their disintegration products, silica, fungi, insects and mites. The clinical syndromes described in relation to exposure to grain dust are chronic bronchitis, grain dust asthma, extrinsic allergic alveolitis, grain fever and silo-filler's lung. Rhinitis and conjunctivitis are also common in grain workers. While the concentration and the quality of dust influence the frequency and the type of clinical syndrome in grain workers, host factors are also important. Of the latter, smoking is the most important factor influencing the frequency of chronic bronchitis. The role of atopy and of bronchial hyperreactivity in grain dust asthma has yet to be assessed. Several well designed studies are currently being carried out in North America not only to delineate the frequency of the respiratory abnormalities, the pathogenetic mechanisms and the host factors, but also to establish a meaningful threshold limit concentration for grain dust. Images p1272-a PMID:348288

  16. Modelling of grain refinement driven by negative grain boundary energy

    Czech Academy of Sciences Publication Activity Database

    Fischer, F. D.; Zickler, G. A.; Svoboda, Jiří

    2017-01-01

    Roč. 97, č. 23 (2017), s. 1963-1977 ISSN 1478-6435 R&D Projects: GA ČR(CZ) GA15-06390S Institutional support: RVO:68081723 Keywords : grain refinement * grain nucleation * distribution concept * jump on distribution function Subject RIV: BJ - Thermodynamics OBOR OECD: Thermodynamics Impact factor: 1.505, year: 2016

  17. Ionizing radiation for insect control in grain and grain products

    International Nuclear Information System (INIS)

    Tilton, E.W.; Brower, J.H.

    1987-01-01

    A technical review summarizes and discusses information on various aspects of the use of ionizing radiation for the control of insect infestation in grains and grain products. Topics include: the effects of ionizing radiation on insects infesting stored-grain products; the 2 main types of irradiators (electron accelerators; radioisotopes (e.g.: Co-60; Cs-137); dosimetry systems and methodology; variations in radiation resistance by stored-product pests; the proper selection of radiation dose; the effects of combining various treatments (temperature, infrared/microwave radiation, hypoxia, chemicals) with ionizing radiation; sublethal radiation for controlling bulk grain insects; the feeding capacity of irradiated insects; the susceptibility of insecticide-resistant insects to ionizing radiation; and the possible resistance of insects to ionizing radiation. Practical aspects of removing insects from irradiated grain also are discussed

  18. The influence of the grain boundary strength on the macroscopic properties of a polycrystalline aggregate

    International Nuclear Information System (INIS)

    Simonovski, Igor; Cizelj, Leon; Garrido, Oriol Costa

    2013-01-01

    Highlights: ► Grain boundary stiffness should be at least 1.5× higher that the stiffness of bulk grains. ► The ratio δ n pl /δ n el should be at least 400. ► Simultaneous increase of δ n el and δ n pl at constant grain boundary strength increases numerical stability but results in high percentage of damage grain boundary area. ► Shear contributes significantly to damage initialization. -- Abstract: In this work a model, based on a X-ray diffraction contrast tomography data of a stainless steel wire with a diameter of 0.4 mm is presented. As measured 3D grain geometry and crystallographic orientation of individual grains are directly transferred into a finite element model. Anisotropic elasticity and crystal plasticity constitutive laws are used for the bulk grain material while the grain boundaries are explicitly modeled using the cohesive zone approach. A parametric study on the effects of the grain boundary strength and other cohesive zone parameters on the macroscopic response and damaged grain boundary area of a polycrystalline aggregate is presented. Recommendations for the cohesive zone parameters values aimed at achieving low damaged grain boundary area during numerical tensile tests are given while at the same time taking into account the numerical stability of the simulations

  19. The influence of the grain boundary strength on the macroscopic properties of a polycrystalline aggregate

    Energy Technology Data Exchange (ETDEWEB)

    Simonovski, Igor, E-mail: Igor.Simonovski@ec.europa.eu [European Commission, DG-JRC, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Cizelj, Leon, E-mail: Leon.Cizelj@ijs.si [Jožef Stefan Institute, Reactor Engineering Division, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); Garrido, Oriol Costa, E-mail: Oriol.Costa@ijs.si [Jožef Stefan Institute, Reactor Engineering Division, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia)

    2013-08-15

    Highlights: ► Grain boundary stiffness should be at least 1.5× higher that the stiffness of bulk grains. ► The ratio δ{sub n}{sup pl}/δ{sub n}{sup el} should be at least 400. ► Simultaneous increase of δ{sub n}{sup el} and δ{sub n}{sup pl} at constant grain boundary strength increases numerical stability but results in high percentage of damage grain boundary area. ► Shear contributes significantly to damage initialization. -- Abstract: In this work a model, based on a X-ray diffraction contrast tomography data of a stainless steel wire with a diameter of 0.4 mm is presented. As measured 3D grain geometry and crystallographic orientation of individual grains are directly transferred into a finite element model. Anisotropic elasticity and crystal plasticity constitutive laws are used for the bulk grain material while the grain boundaries are explicitly modeled using the cohesive zone approach. A parametric study on the effects of the grain boundary strength and other cohesive zone parameters on the macroscopic response and damaged grain boundary area of a polycrystalline aggregate is presented. Recommendations for the cohesive zone parameters values aimed at achieving low damaged grain boundary area during numerical tensile tests are given while at the same time taking into account the numerical stability of the simulations.

  20. Molecular Dynamics Simulations of Grain Boundary and Bulk Diffusion in Metals.

    Science.gov (United States)

    Plimpton, Steven James

    Diffusion is a microscopic mass transport mechanism that underlies many important macroscopic phenomena affecting the structural, electrical, and mechanical properties of metals. This thesis presents results from atomistic simulation studies of diffusion both in bulk and in the fast diffusion paths known as grain boundaries. Using the principles of molecular dynamics single boundaries are studied and their structure and dynamic properties characterized. In particular, tilt boundary bicrystal and bulk models of fcc Al and bcc alpha-Fe are simulated. Diffusion coefficients and activation energies for atomic motion are calculated for both models and compared to experimental data. The influence of the interatomic pair potential on the diffusion is studied in detail. A universal relation between the melting temperature that a pair potential induces in a simulated bulk model and the potential energy barrier height for atomic hopping is derived and used to correlate results for a wide variety of pair potentials. Using these techniques grain boundary and bulk diffusion coefficients for any fcc material can be estimated from simple static calculations without the need to perform more time-consuming dynamic simulations. The influences of two other factors on grain boundary diffusion are also studied because of the interest of the microelectronics industry in the diffusion related reliability problem known as electromigration. The first factor, known to affect the self diffusion rate of Al, is the presence of Cu impurity atoms in Al tilt boundaries. The bicrystal model for Al is seeded randomly with Cu atoms and a simple hybrid Morse potential used to model the Al-Cu interaction. While some effect due to the Cu is noted, it is concluded that pair potentials are likely an inadequate approximation for the alloy system. The second factor studied is the effect of the boundary orientation angle on the diffusion rate. Symmetric bcc Fe boundaries are relaxed to find optimal

  1. Evaluation of Rock Powdering Methods to Obtain Fine-grained Samples for CHEMIN, a Combined XRD/XRF Instrument

    Science.gov (United States)

    Chipera, S. J.; Vaniman, D. T.; Bish, D. L.; Sarrazin, P.; Feldman, S.; Blake, D. F.; Bearman, G.; Bar-Cohen, Y.

    2004-01-01

    A miniature XRD/XRF (X-ray diffraction / X-ray fluorescence) instrument, CHEMIN, is currently being developed for definitive mineralogic analysis of soils and rocks on Mars. One of the technical issues that must be addressed to enable remote XRD analysis is how best to obtain a representative sample powder for analysis. For powder XRD analyses, it is beneficial to have a fine-grained sample to reduce preferred orientation effects and to provide a statistically significant number of crystallites to the X-ray beam. Although a two-dimensional detector as used in the CHEMIN instrument will produce good results even with poorly prepared powder, the quality of the data will improve and the time required for data collection will be reduced if the sample is fine-grained and randomly oriented. A variety of methods have been proposed for XRD sample preparation. Chipera et al. presented grain size distributions and XRD results from powders generated with an Ultrasonic/Sonic Driller/Corer (USDC) currently being developed at JPL. The USDC was shown to be an effective instrument for sampling rock to produce powder suitable for XRD. In this paper, we compare powder prepared using the USDC with powder obtained with a miniaturized rock crusher developed at JPL and with powder obtained with a rotary tungsten carbide bit to powders obtained from a laboratory bench-scale Retsch mill (provides benchmark mineralogical data). These comparisons will allow assessment of the suitability of these methods for analysis by an XRD/XRF instrument such as CHEMIN.

  2. Whole-grain and blood lipid changes in apparently healthy adults

    DEFF Research Database (Denmark)

    Hollænder, Pernille Lærke Bjørndal; Ross, Alastair B; Kristensen, Mette Bredal

    2015-01-01

    BACKGROUND: Whole grains are recognized for their potential role in preventing cardiovascular diseases; however, results from randomized controlled studies on blood lipids are inconsistent, potentially because of compositional differences between individual grain types for some nutrients, including...... dietary fiber. OBJECTIVE: Using a meta-analytic approach, we assessed the effect of whole-grain compared with non-whole-grain foods on changes in total cholesterol (TC), LDL cholesterol, HDL cholesterol, and triglycerides. DESIGN: We conducted a systematic literature search in selected databases. Studies...... were included if they were randomized controlled comparisons between whole-grain foods and a non-whole-grain control in adults. A total of 6069 articles were screened for eligibility, and data were extracted from 24 studies. Weighted mean differences were calculated, and meta-regression analyses were...

  3. Entrepreneurial orientation, market orientation, and competitive environment

    DEFF Research Database (Denmark)

    Sørensen, Hans Eibe; Cadogan, John W.

    This study sheds light on the role that the competitive environment plays in determining how elements of market orientation and elements of entrepreneurial orientation interact to influence business success. We develop a model in which we postulate that market orientation, entrepreneurial...... orientation, and competitive environment shape business performance via a three-way interaction. We test the model using primary data from the CEOs of 270 CEO of manufacturing firms, together with secondary data on these firms' profit performance. An assessment of the results indicates that customer...... orientation moderates the positive relationships between the competitiveness element of entrepreneurial orientation and market share and return on assets (ROA): the positive relationships between competitiveness and market share and competitiveness and ROA become stronger the greater the firms' customer...

  4. Performance evaluation of Grain family and Espresso ciphers for applications on resource constrained devices

    Directory of Open Access Journals (Sweden)

    Subhrajyoti Deb

    2018-03-01

    Full Text Available A secure stream cipher is an effective security solution for applications running on resource-constrained devices. The Grain family of stream ciphers (Grain v1, Grain-128, and Grain-128a is a family of stream ciphers designed for low-end devices. Similarly, Espresso is a lightweight stream cipher that was developed recently for 5G wireless mobile communication. The randomness of the keystream produced by a stream cipher is a good indicator of its security strength. In this study, we have analyzed the randomness properties of the keystreams produced by both the Grain Family and Espresso ciphers using the statistical packages DieHarder and NIST STS. We also analyzed their performances in two constrained devices (ATmega328P and ESP8266 based on three attainable parameters, namely computation time, memory, and power consumption. Keywords: Stream cipher, Randomness, Dieharder, NIST STS

  5. Algorithm for repairing the damaged images of grain structures obtained from the cellular automata and measurement of grain size

    Science.gov (United States)

    Ramírez-López, A.; Romero-Romo, M. A.; Muñoz-Negron, D.; López-Ramírez, S.; Escarela-Pérez, R.; Duran-Valencia, C.

    2012-10-01

    Computational models are developed to create grain structures using mathematical algorithms based on the chaos theory such as cellular automaton, geometrical models, fractals, and stochastic methods. Because of the chaotic nature of grain structures, some of the most popular routines are based on the Monte Carlo method, statistical distributions, and random walk methods, which can be easily programmed and included in nested loops. Nevertheless, grain structures are not well defined as the results of computational errors and numerical inconsistencies on mathematical methods. Due to the finite definition of numbers or the numerical restrictions during the simulation of solidification, damaged images appear on the screen. These images must be repaired to obtain a good measurement of grain geometrical properties. Some mathematical algorithms were developed to repair, measure, and characterize grain structures obtained from cellular automata in the present work. An appropriate measurement of grain size and the corrected identification of interfaces and length are very important topics in materials science because they are the representation and validation of mathematical models with real samples. As a result, the developed algorithms are tested and proved to be appropriate and efficient to eliminate the errors and characterize the grain structures.

  6. Nitrogen dose and plant density effects on popcorn grain yield ...

    African Journals Online (AJOL)

    and plant densities on grain yield and yield-related plant characteristics of popcorn in Hatay, located at Southern Mediterranean region of Turkey, during 2002 and 2003. The experiment was designed in a randomized complete block design with a split-plot arrangement with three replications. Nitrogen doses of 0, 120, 180 ...

  7. Analysis on the energetics, magnetism and electronic properties in a 45° ZnO grain boundary doped with Gd

    KAUST Repository

    Devi, Assa Aravindh Sasikala; Roqan, Iman S.

    2018-01-01

    The structural stability and magnetic properties of a grain boundary (GB) formed by aligning two ZnO single crystals oriented at an angle of 45° is investigated by density functional theory, using generalized gradient approximation (GGA) and taking

  8. Stochastic theory of grain growth

    International Nuclear Information System (INIS)

    Hu Haiyun; Xing Xiusan.

    1990-11-01

    The purpose of this note is to set up a stochastic theory of grain growth and to derive the statistical distribution function and the average value of the grain radius so as to match them with the experiment further. 8 refs, 1 fig

  9. NUTRITIONAL CHARACTERIZATION OF GRAIN AMARANTH ...

    African Journals Online (AJOL)

    IBUKUN

    children; increased body mass index of people formerly wasted by HIV/AIDS; ... and market acceptability of Amaranth cruentus based products in order to ... Peru, grain amaranth also used the grains as food; preparation of local beverage; added ... initiated to know the proximate composition, mineral and vitamin contents of ...

  10. Stress-driven grain growth

    CSIR Research Space (South Africa)

    Nabarro, FRN

    1998-11-13

    Full Text Available of length b (1+ epsilon) is parallel to sigma, embedded in a grain in which the lattice vector b (1+ epsilon) is transverse to sigma. If the embedded grain grows at the expense of its matrix, the source of the stress will do work, and therefore the presence...

  11. Effect of grain defects on the mechanical behavior of nickel-based single crystal superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Haibin; Guo, Haiding [Nanjing Univ. of Aeronautics and Astronautics (China). Jiangsu Province Key Lab. of Aerospace Power System

    2017-03-15

    In this paper, a single crystal (SC) partition model, consisting of primary grains and grain defects, is proposed to simulate the weakening effect of grain defects generated at geometric discontinuities of SC materials. The plastic deformation of SC superalloy is described with the modified yield criterion, associated flow rule and hardening law. Then a bicrystal model containing only one group of misoriented grains under uniaxial loading is constructed and analyzed in the commercial finite element software ABAQUS. The simulation results indicate that the yield strength and elastic modulus of misoriented grains, which are determined by the crystallographic orientation, have a significant effect on the stress distribution of the bicrystal model. A critical stress, which is calculated by the stress state at critical regions, is proposed to evaluate the local stress rise at the sub-boundary of primary and misoriented grains.

  12. Grain Refinement of Freeform Fabricated Ti-6Al-4V Alloy Using Beam/Arc Modulation

    Science.gov (United States)

    Mitzner, Scott; Liu, Stephen; Domack, Marcia S.; Hafley, Robert A.

    2012-01-01

    Grain refinement can significantly improve the mechanical properties of freeform-fabricated Ti-6Al-4V alloy, promoting increased strength and enhanced isotropy compared with coarser grained material. Large beta-grains can lead to a segregated microstructure, in regard to both alpha-phase morphology and alpha-lath orientation. Beam modulation, which has been used in conventional fusion welding to promote grain refinement, is explored in this study for use in additive manufacturing processes including electron beam freeform fabrication (EBF(sup 3)) and gas-tungsten arc (GTA) deposition to alter solidification behavior and produce a refined microstructure. The dynamic molten pool size induced by beam modulation causes rapid heat flow variance and results in a more competitive grain growth environment, reducing grain size. Consequently, improved isotropy and strength can be achieved with relatively small adjustments to deposition parameters.

  13. Effect of grain defects on the mechanical behavior of nickel-based single crystal superalloy

    International Nuclear Information System (INIS)

    Tang, Haibin; Guo, Haiding

    2017-01-01

    In this paper, a single crystal (SC) partition model, consisting of primary grains and grain defects, is proposed to simulate the weakening effect of grain defects generated at geometric discontinuities of SC materials. The plastic deformation of SC superalloy is described with the modified yield criterion, associated flow rule and hardening law. Then a bicrystal model containing only one group of misoriented grains under uniaxial loading is constructed and analyzed in the commercial finite element software ABAQUS. The simulation results indicate that the yield strength and elastic modulus of misoriented grains, which are determined by the crystallographic orientation, have a significant effect on the stress distribution of the bicrystal model. A critical stress, which is calculated by the stress state at critical regions, is proposed to evaluate the local stress rise at the sub-boundary of primary and misoriented grains.

  14. Grain boundary cavity growth under applied stress and internal pressure

    International Nuclear Information System (INIS)

    Mancuso, J.F.

    1977-08-01

    The growth of grain boundary cavities under applied stress and internal gas pressure was investigated. Methane gas filled cavities were produced by the C + 4H reversible CH4 reaction in the grain boundaries of type 270 nickel by hydrogen charging in an autoclave at 500 0 C with a hydrogen pressure of either 3.4 or 14.5 MPa. Intergranular fracture of nickel was achieved at a charging temperature of 300 0 C and 10.3 MPa hydrogen pressure. Cavities on the grain boundaries were observed in the scanning electron microscope after fracture. Photomicrographs of the cavities were produced in stereo pairs which were analyzed so as to correct for perspective distortion and also to determine the orientational dependence of cavity growth under an applied tensile stress

  15. Autonomous grain combine control system

    Science.gov (United States)

    Hoskinson, Reed L.; Kenney, Kevin L.; Lucas, James R.; Prickel, Marvin A.

    2013-06-25

    A system for controlling a grain combine having a rotor/cylinder, a sieve, a fan, a concave, a feeder, a header, an engine, and a control system. The feeder of the grain combine is engaged and the header is lowered. A separator loss target, engine load target, and a sieve loss target are selected. Grain is harvested with the lowered header passing the grain through the engaged feeder. Separator loss, sieve loss, engine load and ground speed of the grain combine are continuously monitored during the harvesting. If the monitored separator loss exceeds the selected separator loss target, the speed of the rotor/cylinder, the concave setting, the engine load target, or a combination thereof is adjusted. If the monitored sieve loss exceeds the selected sieve loss target, the speed of the fan, the size of the sieve openings, or the engine load target is adjusted.

  16. Inferential statistics of electron backscatter diffraction data from within individual crystalline grains

    DEFF Research Database (Denmark)

    Bachmann, Florian; Hielscher, Ralf; Jupp, Peter E.

    2010-01-01

    -spatial statistical analysis adapts ideas borrowed from the Bingham quaternion distribution on . Special emphasis is put on the mathematical definition and the numerical determination of a `mean orientation' characterizing the crystallographic grain as well as on distinguishing several types of symmetry......Highly concentrated distributed crystallographic orientation measurements within individual crystalline grains are analysed by means of ordinary statistics neglecting their spatial reference. Since crystallographic orientations are modelled as left cosets of a given subgroup of SO(3), the non...... of the orientation distribution with respect to the mean orientation, like spherical, prolate or oblate symmetry. Applications to simulated as well as to experimental data are presented. All computations have been done with the free and open-source texture toolbox MTEX....

  17. A multi-scale homogenization model for fine-grained porous viscoplastic polycrystals: I - Finite-strain theory

    Science.gov (United States)

    Song, Dawei; Ponte Castañeda, P.

    2018-06-01

    We make use of the recently developed iterated second-order homogenization method to obtain finite-strain constitutive models for the macroscopic response of porous polycrystals consisting of large pores randomly distributed in a fine-grained polycrystalline matrix. The porous polycrystal is modeled as a three-scale composite, where the grains are described by single-crystal viscoplasticity and the pores are assumed to be large compared to the grain size. The method makes use of a linear comparison composite (LCC) with the same substructure as the actual nonlinear composite, but whose local properties are chosen optimally via a suitably designed variational statement. In turn, the effective properties of the resulting three-scale LCC are determined by means of a sequential homogenization procedure, utilizing the self-consistent estimates for the effective behavior of the polycrystalline matrix, and the Willis estimates for the effective behavior of the porous composite. The iterated homogenization procedure allows for a more accurate characterization of the properties of the matrix by means of a finer "discretization" of the properties of the LCC to obtain improved estimates, especially at low porosities, high nonlinearties and high triaxialities. In addition, consistent homogenization estimates for the average strain rate and spin fields in the pores and grains are used to develop evolution laws for the substructural variables, including the porosity, pore shape and orientation, as well as the "crystallographic" and "morphological" textures of the underlying matrix. In Part II of this work has appeared in Song and Ponte Castañeda (2018b), the model will be used to generate estimates for both the instantaneous effective response and the evolution of the microstructure for porous FCC and HCP polycrystals under various loading conditions.

  18. Methods of assessing grain-size distribution during grain growth

    DEFF Research Database (Denmark)

    Tweed, Cherry J.; Hansen, Niels; Ralph, Brian

    1985-01-01

    This paper considers methods of obtaining grain-size distributions and ways of describing them. In order to collect statistically useful amounts of data, an automatic image analyzer is used, and the resulting data are subjected to a series of tests that evaluate the differences between two related...... distributions (before and after grain growth). The distributions are measured from two-dimensional sections, and both the data and the corresponding true three-dimensional grain-size distributions (obtained by stereological analysis) are collected. The techniques described here are illustrated by reference...

  19. Mechanical stability of individual austenite grains in TRIP steel studied by synchrotron X-ray diffraction during tensile loading

    Energy Technology Data Exchange (ETDEWEB)

    Blondé, R. [Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Materials Innovation Institute, Mekelweg 2, 2628 CD Delft (Netherlands); Jimenez-Melero, E. [Dalton Cumbrian Facility, The University of Manchester, Westlakes Science and Technology Park, Moor Row, Cumbria, CA24 3HA (United Kingdom); Zhao, L. [Materials Innovation Institute, Mekelweg 2, 2628 CD Delft (Netherlands); Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands); Wright, J.P. [European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, BP 220, 38043 Grenoble Cedex (France); Brück, E. [Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Zwaag, S. van der [Novel Aerospace Materials Group, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS, Delft (Netherlands); Dijk, N.H. van, E-mail: N.H.vanDijk@tudelft.nl [Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands)

    2014-11-17

    The stability of individual metastable austenite grains in low-alloyed TRIP steels has been studied during tensile loading using high-energy X-ray diffraction. The carbon concentration, grain volume and grain orientation with respect to the loading direction was monitored for a large number of individual grains in the bulk microstructure. Most austenite grains transform into martensite in a single transformation step once a critical load is reached. The orientation-dependent stability of austenite grains was found to depend on their Schmid factor with respect to the loading direction. Under the applied tensile stress the average Schmid factor decreased from an initial value of 0.44 to 0.41 at 243 MPa. The present study reveals the complex interplay of microstructural parameters on the mechanical stability of individual austenite grains, where the largest grains with the lowest carbon content tend to transform first. Under the applied tensile stress the average carbon concentration of the austenite grains increased from an initial value of 0.90 to 1.00 wt% C at 243 MPa, while the average grain volume of the austenite grains decreased from an initial value of 19 to 15 µm{sup 3} at 243 MPa.

  20. Whole grain and refined grain consumption and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of cohort studies.

    Science.gov (United States)

    Aune, Dagfinn; Norat, Teresa; Romundstad, Pål; Vatten, Lars J

    2013-11-01

    Several studies have suggested a protective effect of intake of whole grains, but not refined grains on type 2 diabetes risk, but the dose-response relationship between different types of grains and type 2 diabetes has not been established. We conducted a systematic review and meta-analysis of prospective studies of grain intake and type 2 diabetes. We searched the PubMed database for studies of grain intake and risk of type 2 diabetes, up to June 5th, 2013. Summary relative risks were calculated using a random effects model. Sixteen cohort studies were included in the analyses. The summary relative risk per 3 servings per day was 0.68 (95% CI 0.58-0.81, I(2) = 82%, n = 10) for whole grains and 0.95 (95% CI 0.88-1.04, I(2) = 53%, n = 6) for refined grains. A nonlinear association was observed for whole grains, p nonlinearity cereals, wheat bran and brown rice, but these results were based on few studies, while white rice was associated with increased risk. Our meta-analysis suggests that a high whole grain intake, but not refined grains, is associated with reduced type 2 diabetes risk. However, a positive association with intake of white rice and inverse associations between several specific types of whole grains and type 2 diabetes warrant further investigations. Our results support public health recommendations to replace refined grains with whole grains and suggest that at least two servings of whole grains per day should be consumed to reduce type 2 diabetes risk.

  1. Three-dimensional grain structure of sintered bulk strontium titanate from X-ray diffraction contrast tomography

    DEFF Research Database (Denmark)

    Syha, M.; Rheinheimer, W.; Bäurer, M.

    2012-01-01

    The three-dimensional grain boundary network of sintered bulk strontium titanate is reconstructed using X-ray diffraction contrast tomography, a non-destructive technique for determining the grain shape and crystallographic orientation in polycrystals that is ideally suited for detailed studies...

  2. Prevalence of IgE antibodies to grain and grain dust in grain elevator workers

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, D.M.; Romeo, P.A.; Olenchock, S.A.

    1986-04-01

    IgE-mediated allergic reactions have been postulated to contribute to respiratory reactions seen in workers exposed to grain dusts. In an attempt better to define the prevalence of IgE antibodies in workers exposed to grain dusts, we performed the radioallergosorbent test (RAST) on worker sera using both commercial allergens prepared from grain and worksite allergens prepared from grain dust samples collected at the worksite. We found that the two types of reagents identified different populations with respect to the specificity of IgE antibodies present. The RAST assay performed using worksite allergens correlated well with skin test procedures. These results may allow us to gain better understanding of allergy associated with grain dust exposure, and document the utility of the RAST assay in assessment of occupational allergies.

  3. Prevalence of IgE antibodies to grain and grain dust in grain elevator workers.

    Science.gov (United States)

    Lewis, D M; Romeo, P A; Olenchock, S A

    1986-01-01

    IgE-mediated allergic reactions have been postulated to contribute to respiratory reactions seen in workers exposed to grain dusts. In an attempt better to define the prevalence of IgE antibodies in workers exposed to grain dusts, we performed the radioallergosorbent test (RAST) on worker sera using both commercial allergens prepared from grain and worksite allergens prepared from grain dust samples collected at the worksite. We found that the two types of reagents identified different populations with respect to the specificity of IgE antibodies present. The RAST assay performed using worksite allergens correlated well with skin test procedures. These results may allow us to gain better understanding of allergy associated with grain dust exposure, and document the utility of the RAST assay in assessment of occupational allergies. PMID:3709478

  4. Prevalence of IgE antibodies to grain and grain dust in grain elevator workers

    International Nuclear Information System (INIS)

    Lewis, D.M.; Romeo, P.A.; Olenchock, S.A.

    1986-01-01

    IgE-mediated allergic reactions have been postulated to contribute to respiratory reactions seen in workers exposed to grain dusts. In an attempt better to define the prevalence of IgE antibodies in workers exposed to grain dusts, we performed the radioallergosorbent test (RAST) on worker sera using both commercial allergens prepared from grain and worksite allergens prepared from grain dust samples collected at the worksite. We found that the two types of reagents identified different populations with respect to the specificity of IgE antibodies present. The RAST assay performed using worksite allergens correlated well with skin test procedures. These results may allow us to gain better understanding of allergy associated with grain dust exposure, and document the utility of the RAST assay in assessment of occupational allergies

  5. Effect of pre-existing crystallographic preferred orientation on the rheology of Carrara marble

    NARCIS (Netherlands)

    de Raadt, W.S.; Burlini, L.; Kunze, K.; Spiers, C.J.

    2014-01-01

    Abstract Localized deformation during high temperature plastic flow is frequently attributed to mechanical weakening caused by grain size reduction and, in some cases, by the development of a crystallographic preferred orientation (CPO). This study aims to investigate experimentally the contribution

  6. MATHEMATICAL MODEL OF GRAIN MICRONIZATION

    Directory of Open Access Journals (Sweden)

    V. A. Afanas’ev

    2014-01-01

    Full Text Available Summary. During micronisation grain moisture evaporates mainly in decreasing drying rate period. Grain layer located on the surface of the conveyor micronisers will be regarded as horizontal plate. Due to the fact that the micronisation process the surface of the grain evaporates little moisture (within 2-7 % is assumed constant plate thickness. Because in the process of micronization grain structure is changing, in order to achieve an exact solution of the equations necessary to take into account changes thermophysical, optical and others. Equation of heat transfer is necessary to add a term that is responsible for the infrared heating. Because of the small thickness of the grain, neglecting the processes occurring at the edge of the grain, that is actually consider the problem of an infinite plate. To check the adequacy of the mathematical model of the process of micronisation of wheat grain moisture content must be comparable to the function of time, obtained by solving the system of equations with the measured experimental data of experience. Numerical solution of a system of equations for the period of decreasing drying rate is feasible with the help of the Maple 14, substituting the values of the constants in the system. Calculation of the average relative error does not exceed 7- 10 %, and shows a good agreement between the calculated data and the experimental values.

  7. PESTICIDES USE AMONG GRAIN MERCHANTS IN MUBI GRAIN ...

    African Journals Online (AJOL)

    AGROSEARCH UIL

    pose the greatest threat to increased food production, storage and handling ... are to: assess pest control practices of grain merchants in Mubi markets with a .... This further cements the fact that multiple routes of contaminations are possible.

  8. Why Is It Important to Eat Grains, Especially Whole Grains?

    Science.gov (United States)

    ... Style What Is a Healthy Eating Style? Choosing Foods and Beverages Saturated, Unsaturated, and Trans Fats Sodium Added Sugars ... may reduce the risk of heart disease. Consuming foods containing fiber, ... weight management. Eating grain products fortified with folate before and ...

  9. Monte carlo simulation of anisotropic grain growth in liquid phase sintering

    International Nuclear Information System (INIS)

    Han, Yoon Soo; Kim, Do Kyung

    2003-01-01

    One of the key techniques in modern engineering ceramic system is microstructural control of anisotropic grain growth because grain orientation and shape proved to have an influence on mechanic, dielectric and electric behavior of ceramics. But until now, computer simulation for grain growth has not sufficiently addressed to this subject. The reason is that simulation algorithm was laborious because it has to contain mass transfer through liquid phase and especially anisotropic grain growth has to be considered based on interfacial properties in real system. The goal of present study is simulation of anisotropic grain growth in liquid phase by Q-states model. To give anisotropic inherency to grains, constraint on mobility to specific boundaries was applied. For comparison, we measured grain size distribution and deduced grain growth kinetics from relation ship between average grain size and time. As a result, the grain size distribution functions become broader and the peak height decreases as the anisotropy is increased. The growth exponent 0.67 and 0.47 found by linear fitting have slightly different values in comparison with work of Grest et al. but similar is trend to the decrease of exponent with anisotropy

  10. Diffusion of oriented particles in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Haber, René [Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Centre for Nonlinear Studies, Institute of Cybernetics at Tallinn University of Technology, Akadeemia tee 21, 12618 Tallinn (Estonia); Prehl, Janett [Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Herrmann, Heiko [Centre for Nonlinear Studies, Institute of Cybernetics at Tallinn University of Technology, Akadeemia tee 21, 12618 Tallinn (Estonia); Hoffmann, Karl Heinz, E-mail: hoffmann@physik.tu-chemnitz.de [Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz (Germany)

    2013-11-29

    Diffusion of particles in porous media often shows subdiffusive behavior. Here, we analyze the dynamics of particles exhibiting an orientation. The features we focus on are geometrical restrictions and the dynamical consequences of the interactions between the local surrounding structure and the particle orientation. This interaction can lead to particles getting temporarily stuck in parts of the structure. Modeling this interaction by a particular random walk dynamics on fractal structures we find that the random walk dimension is not affected while the diffusion constant shows a variety of interesting and surprising features.

  11. Diffusion of oriented particles in porous media

    International Nuclear Information System (INIS)

    Haber, René; Prehl, Janett; Herrmann, Heiko; Hoffmann, Karl Heinz

    2013-01-01

    Diffusion of particles in porous media often shows subdiffusive behavior. Here, we analyze the dynamics of particles exhibiting an orientation. The features we focus on are geometrical restrictions and the dynamical consequences of the interactions between the local surrounding structure and the particle orientation. This interaction can lead to particles getting temporarily stuck in parts of the structure. Modeling this interaction by a particular random walk dynamics on fractal structures we find that the random walk dimension is not affected while the diffusion constant shows a variety of interesting and surprising features.

  12. Chemisputtering of interstellar graphite grains

    International Nuclear Information System (INIS)

    Draine, B.T.

    1979-01-01

    The rate of erosion of interstellar graphite grains as a result of chemical reaction with H, N, and O is estimated using the available experiment evidence. It is argued that ''chemical sputtering'' yields for interstellar graphite grains will be much less than unity, contrary to earlier estimates by Barlow and Silk. Chemical sputtering of graphite grains in evolving H II regions is found to be unimportant, except in extremely compact (n/sub H/> or approx. =10 5 cm -3 ) H II regions. Alternative explanations are considered for the apparent weakness of the lambda=2175 A extinction ''bump'' in the direction of several early type stars

  13. Grain growth competition during thin-sample directional solidification of dendritic microstructures: A phase-field study

    International Nuclear Information System (INIS)

    Tourret, D.; Song, Y.; Clarke, A.J.; Karma, A.

    2017-01-01

    We present the results of a comprehensive phase-field study of columnar grain growth competition in bi-crystalline samples in two dimensions (2D) and in three dimensions (3D) for small sample thicknesses allowing a single row of dendrites to form. We focus on the selection of grain boundary (GB) orientation during directional solidification in the steady-state dendritic regime, and study its dependence upon the orientation of two competing grains. In 2D, we map the entire orientation range for both grains, performing several simulations for each configuration to account for the stochasticity of GB orientation selection and to assess the average GB behavior. We find that GB orientation selection depends strongly on whether the primary dendrite growth directions have lateral components (i.e. components perpendicular to the axis of the temperature gradient) that point in the same or opposite directions in the two grains. We identify a range of grain orientations in which grain selection follows the classical description of Walton and Chalmers. We also identify conditions that favor unusual overgrowth of favorably-oriented dendrites at a converging GB. We propose a simple analytical description that reproduces the average GB orientation selection from 2D simulations within statistical fluctuations of a few degrees. In 3D, we find a similar GB orientation selection as in 2D when secondary branches grow in planes parallel and perpendicular to the sample walls. Remarkably, quasi-2D behavior is also observed even when those perpendicular sidebranching planes are rotated by a finite azimuthal angle about the primary dendrite growth axis as long as the absolute values of those azimuthal angles are equal in both grains. In contrast, when the absolute values of those azimuthal angles differ markedly, we find that unusual overgrowth events at a converging GB are promoted by a high azimuthal angle in the least-favorably-oriented grain. We also find that diverging GBs can be

  14. The valuation of commercial grain silos

    African Journals Online (AJOL)

    The valuation of grain silos is a complex exercise when one considers all the variables that affect their ... their grains, larger grain-processing companies, traders, importers or exporters that have ..... 2015: personal interview). The percentages ...

  15. Debris flow rheology: Experimental analysis of fine-grained slurries

    Science.gov (United States)

    Major, Jon J.; Pierson, Thomas C.

    1992-01-01

    The rheology of slurries consisting of ≤2-mm sediment from a natural debris flow deposit was measured using a wide-gap concentric-cylinder viscometer. The influence of sediment concentration and size and distribution of grains on the bulk rheological behavior of the slurries was evaluated at concentrations ranging from 0.44 to 0.66. The slurries exhibit diverse rheological behavior. At shear rates above 5 s−1 the behavior approaches that of a Bingham material; below 5 s−1, sand exerts more influence and slurry behavior deviates from the Bingham idealization. Sand grain interactions dominate the mechanical behavior when sand concentration exceeds 0.2; transient fluctuations in measured torque, time-dependent decay of torque, and hysteresis effects are observed. Grain rubbing, interlocking, and collision cause changes in packing density, particle distribution, grain orientation, and formation and destruction of grain clusters, which may explain the observed behavior. Yield strength and plastic viscosity exhibit order-of-magnitude variation when sediment concentration changes as little as 2–4%. Owing to these complexities, it is unlikely that debris flows can be characterized by a single rheological model.

  16. Theories of Sexual Orientation.

    Science.gov (United States)

    Storms, Michael D.

    1980-01-01

    Results indicated homosexuals, heterosexuals, and bisexuals did not differ within each sex on measures of masculinity and femininity. Strong support was obtained for the hypothesis that sexual orientation relates primarily to erotic fantasy orientation. (Author/DB)

  17. Grain, milling, and head rice yields as affected by nitrogen rate and bio-fertilizer application

    Directory of Open Access Journals (Sweden)

    Saeed FIROUZI

    2015-11-01

    Full Text Available To evaluate the effects of nitrogen rate and bio-fertilizer application on grain, milling, and head rice yields, a field experiment was conducted at Rice Research Station of Tonekabon, Iran, in 2013. The experimental design was a factorial treatment arrangement in a randomized complete block with three replicates. Factors were three N rates (0, 75, and 150 kg ha-1 and two bio-fertilizer applications (inoculation and uninoculation with Nitroxin, a liquid bio-fertilizer containing Azospirillum spp. and Azotobacter spp. bacteria. Analysis of variance showed that rice grain yield, panicle number per m2, grain number per panicle, flag leaves area, biological yield, grains N concentration and uptake, grain protein concentration, and head rice yield were significantly affected by N rate, while bio-fertilizer application had significant effect on rice grain yield, grain number per panicle, flag leaves area, biological yield, harvest index, grains N concentration and uptake, and grain protein concentration. Results showed that regardless of bio-fertilizer application, rice grain and biological yields were significantly increased as N application rate increased from 0 to 75 kg ha-1, but did not significantly increase at the higher N rate (150 kg ha-1. Grain yield was significantly increased following bio-fertilizer application when averaged across N rates. Grains N concentration and uptake were significantly increased as N rate increased up to 75 kg ha-1, but further increases in N rate had no significant effect on these traits. Bio-fertilizer application increased significantly grains N concentration and uptake, when averaged across N rates. Regardless of bio-fertilizer application, head rice yield was significantly increased from 56 % to 60 % when N rate increased from 0 to 150 kg ha-1. Therefore, this experiment illustrated that rice grain and head yields increased with increasing N rate, while bio-fertilizer application increased only rice grain

  18. Orientation effects on indexing of electron backscatter diffraction patterns

    International Nuclear Information System (INIS)

    Nowell, Matthew M.; Wright, Stuart I.

    2005-01-01

    Automated Electron Backscatter Diffraction (EBSD) has become a well-accepted technique for characterizing the crystallographic orientation aspects of polycrystalline microstructures. At the advent of this technique, it was observed that patterns obtained from grains in certain crystallographic orientations were more difficult for the automated indexing algorithms to accurately identify than patterns from other orientations. The origin of this problem is often similarities between the EBSD pattern of the correct orientation and patterns from other orientations or phases. While practical solutions have been found and implemented, the identification of these problem orientations generally occurs only after running an automated scan, as problem orientations are often readily apparent in the resulting orientation maps. However, such an approach only finds those problem orientations that are present in the scan area. It would be advantageous to identify all regions of orientation space that may present problems for automated indexing prior to initiating an automated scan, and to minimize this space through the optimization of acquisition and indexing parameters. This work presents new methods for identifying regions in orientation space where the reliability of the automated indexing is suspect prior to performing a scan. This methodology is used to characterize the impact of various parameters on the indexing algorithm

  19. Spring Small Grains Area Estimation

    Science.gov (United States)

    Palmer, W. F.; Mohler, R. J.

    1986-01-01

    SSG3 automatically estimates acreage of spring small grains from Landsat data. Report describes development and testing of a computerized technique for using Landsat multispectral scanner (MSS) data to estimate acreage of spring small grains (wheat, barley, and oats). Application of technique to analysis of four years of data from United States and Canada yielded estimates of accuracy comparable to those obtained through procedures that rely on trained analysis.

  20. Interstellar Grains: 50 Years On

    OpenAIRE

    Wickramasinghe, N. Chandra

    2011-01-01

    Our understanding of the nature of interstellar grains has evolved considerably over the past half century with the present author and Fred Hoyle being intimately involved at several key stages of progress. The currently fashionable graphite-silicate-organic grain model has all its essential aspects unequivocally traceable to original peer-reviewed publications by the author and/or Fred Hoyle. The prevailing reluctance to accept these clear-cut priorities may be linked to our further work tha...

  1. Grain boundary structure and properties

    International Nuclear Information System (INIS)

    Balluffi, R.W.

    1979-05-01

    An attempt is made to distinguish those fundamental aspects of grain boundaries which should be relevant to the problem of the time dependent fracture of high temperature structural materials. These include the basic phenomena which are thought to be associated with cavitation and cracking at grain boundaries during service and with the more general microstructural changes which occur during both processing and service. A very brief discussion of the current state of knowledge of these fundamentals is given

  2. Effect of Process Variables on the Grain Size and Crystallographic Texture of Hot-Dip Galvanized Coatings

    Science.gov (United States)

    Kaboli, Shirin; McDermid, Joseph R.

    2014-08-01

    A galvanizing simulator was used to determine the effect of galvanizing bath antimony (Sb) content, substrate surface roughness, and cooling rate on the microstructural development of metallic zinc coatings. Substrate surface roughness was varied through the use of relatively rough hot-rolled and relatively smooth bright-rolled steels, cooling rates were varied from 0.1 to 10 K/s, and bulk bath Sb levels were varied from 0 to 0.1 wt pct. In general, it was found that increasing bath Sb content resulted in coatings with a larger grain size and strongly promoted the development of coatings with the close-packed {0002} basal plane parallel to the substrate surface. Increasing substrate surface roughness tended to decrease the coating grain size and promoted a more random coating crystallographic texture, except in the case of the highest Sb content bath (0.1 wt pct Sb), where substrate roughness had no significant effect on grain size except at higher cooling rates (10 K/s). Increased cooling rates tended to decrease the coating grain size and promote the {0002} basal orientation. Calculations showed that increasing the bath Sb content from 0 to 0.1 wt pct Sb increased the dendrite tip growth velocity from 0.06 to 0.11 cm/s by decreasing the solid-liquid interface surface energy from 0.77 to 0.45 J/m2. Increased dendrite tip velocity only partially explains the formation of larger zinc grains at higher Sb levels. It was also found that the classic nucleation theory cannot completely explain the present experimental observations, particularly the effect of increasing the bath Sb, where the classical theory predicts increased nucleation and a finer grain size. In this case, the "poisoning" theory of nucleation sites by segregated Sb may provide a partial explanation. However, any analysis is greatly hampered by the lack of fundamental thermodynamic information such as partition coefficients and surface energies and by a lack of fundamental structural studies. Overall

  3. Crystallographic and morphological relationships between β phase and the Widmanstaetten and allotriomorphic α phase at special β grain boundaries in an α/β titanium alloy

    International Nuclear Information System (INIS)

    Bhattacharyya, D.; Viswanathan, G.B.; Fraser, Hamish L.

    2007-01-01

    In the present study, the relationship between the crystallographic orientations and growth directions of grain boundary-allotriomorphic-α (GB α) and secondary Widmanstaetten α laths growing from the GB α at grain boundaries separating β grains with specific misorientations has been examined. These relationships have been determined using a variety of characterization techniques, including scanning electron microscopy, orientation imaging microscopy, transmission electron microscopy (TEM) and a dual-beam focused ion beam instrument to provide site-selected TEM foils. Two very interesting cases, one in which the two adjacent β grains are rotated mutually by approximately 10.5 o about a common direction and the other in which the two β grains are in a twin relationship, i.e. a 60 o rotation about a common direction, have been studied. It was discovered that the α laths growing into two adjacent β grains from the common grain boundary may have the same orientation in both grains, while they may have either large (∼88.8 o ) or small (28.8 o ) angular differences in growth directions in the two adjacent β grains, depending on the relative misorientation of the β grains. The growth directions of the α laths growing from such boundaries are explained on the basis of the Burgers orientation relationship between the Widmanstaetten α and the β phases and the interfacial structure proposed previously by various workers

  4. Work Tasks as Determinants of Grain Dust and Microbial Exposure in the Norwegian Grain and Compound Feed Industry.

    Science.gov (United States)

    Straumfors, Anne; Heldal, Kari Kulvik; Wouters, Inge M; Eduard, Wijnand

    2015-07-01

    The grain and compound feed industry entails inevitable risks of exposure to grain dust and its microbial content. The objective of this study was therefore to investigate task-dependent exposure differences in order to create knowledge basis for awareness and exposure reducing measures in the Norwegian grain and compound feed industry. A total of 166 samples of airborne dust were collected by full-shift personal sampling during work in 20 grain elevators and compound feed mills during one autumn season and two winter seasons. The personal exposure to grain dust, endotoxins, β-1→3-glucans, bacteria, and fungal spores was quantified and used as individual outcomes in mixed models with worker nested in company as random effect and different departments and tasks as fixed effects. The exposure levels were highest in grain elevator departments. Exposure to endotoxins was particularly high. Tasks that represented the highest and lowest exposures varied depending on the bioaerosol component. The most important determinants for elevated dust exposure were cleaning and process controlling. Cleaning increased the dust exposure level by a factor of 2.44 of the reference, from 0.65 to 1.58mg m(-3), whereas process controlling increased the dust exposure level by a factor of 2.97, from 0.65 to 1.93mg m(-3). Process controlling was associated with significantly less grain dust exposure in compound feed mills and the combined grain elevators and compound feed mills, than in grain elevators. The exposure was reduced by a factor of 0.18 and 0.22, from 1.93 to 0.34mg m(-3) and to 0.42mg m(-3), respectively, compared with the grain elevators. Inspection/maintenance, cleaning, and grain rotation and emptying were determinants of higher exposure to both endotoxin and β-1→3-glucans. Seed winnowing was in addition a strong determinant for endotoxin, whereas mixing of animal feed implied higher β-1→3-glucan exposure. Cleaning was the only task that contributed significantly to

  5. Goddard rattler-jamming mechanism for quantifying pressure dependence of elastic moduli of grain packs

    Energy Technology Data Exchange (ETDEWEB)

    Pride, Steven R.; Berryman, James G.

    2009-01-05

    An analysis is presented to show how it is possible for unconsolidated granular packings to obey overall non-Hertzian pressure dependence due to the imperfect and random spatial arrangements of the grains in these packs. With imperfect arrangement, some gaps that remain between grains can be closed by strains applied to the grain packing. As these gaps are closed, former rattler grains become jammed and new stress-bearing contacts are created that increase the elastic stiffness of the packing. By allowing for such a mechanism, detailed analytical expressions are obtained for increases in bulk modulus of a random packing of grains with increasing stress and strain. Only isotropic stress and strain are considered in this analysis. The model is shown to give a favorable fit to laboratory data on variations in bulk modulus due to variations in applied pressure for bead packs.

  6. Effective search for stable segregation configurations at grain boundaries with data-mining techniques

    Science.gov (United States)

    Kiyohara, Shin; Mizoguchi, Teruyasu

    2018-03-01

    Grain boundary segregation of dopants plays a crucial role in materials properties. To investigate the dopant segregation behavior at the grain boundary, an enormous number of combinations have to be considered in the segregation of multiple dopants at the complex grain boundary structures. Here, two data mining techniques, the random-forests regression and the genetic algorithm, were applied to determine stable segregation sites at grain boundaries efficiently. Using the random-forests method, a predictive model was constructed from 2% of the segregation configurations and it has been shown that this model could determine the stable segregation configurations. Furthermore, the genetic algorithm also successfully determined the most stable segregation configuration with great efficiency. We demonstrate that these approaches are quite effective to investigate the dopant segregation behaviors at grain boundaries.

  7. Tunable random packings

    International Nuclear Information System (INIS)

    Lumay, G; Vandewalle, N

    2007-01-01

    We present an experimental protocol that allows one to tune the packing fraction η of a random pile of ferromagnetic spheres from a value close to the lower limit of random loose packing η RLP ≅0.56 to the upper limit of random close packing η RCP ≅0.64. This broad range of packing fraction values is obtained under normal gravity in air, by adjusting a magnetic cohesion between the grains during the formation of the pile. Attractive and repulsive magnetic interactions are found to affect stongly the internal structure and the stability of sphere packing. After the formation of the pile, the induced cohesion is decreased continuously along a linear decreasing ramp. The controlled collapse of the pile is found to generate various and reproducible values of the random packing fraction η

  8. Investigation of the role of grain boundary on the mechanical properties of metals

    International Nuclear Information System (INIS)

    Kheradmand, Nousha; Barnoush, Afrooz; Vehoff, Horst

    2010-01-01

    Compression testing of micropillars was used to investigate the gain boundary effect on the strength of metals which is especially interesting in ultra fine grained and nanocrystalline metals. Single and bicrystal micropillars of different sizes and crystallographic orientations were fabricated using a focused ion beam system and the compression test was performed with a nanoindenter. A reduction of the pillar size as well as the introduction of a grain boundary results in an increase in the yield strength. The results show that the size and the orientation of different adjoining crystals in bicrystalline pillars have an obvious effect on dislocation nucleation and multiplication.

  9. The Relevance of Grain Dissection for Grain Size Reduction in Polar Ice : Insight from Numerical Models and Ice Core Microstructure Analysis

    NARCIS (Netherlands)

    Steinbach, F.; Kuiper, E.N.; Eichler, J.; Bons, P. D.; Drury, M. R.; Griera, A.; Pennock, G.M.; Weikusat, I.

    2017-01-01

    The flow of ice depends on the properties of the aggregate of individual ice crystals, such as grain size or lattice orientation distributions. Therefore, an understanding of the processes controlling ice micro-dynamics is needed to ultimately develop a physically based macroscopic ice flow law. We

  10. Understanding political market orientation

    DEFF Research Database (Denmark)

    Ormrod, Robert P.; Henneberg, Stephan C.

    influences of such behavior. The study includes structural equation modeling to investigate several propositions. While the results show that political parties need to focus on several different aspects of market-oriented behavior, especially using an internal and external orientation as cultural antecedents......This article develops a conceptual framework and measurement model of political market orientation that consists of attitudinal and behavioural constructs. The article reports on perceived relationships among different behavioral aspects of political market orientation and the attitudinal......, a more surprising result is the inconclusive effect of a voter orientation on market-oriented behaviours. The article discusses the findings in the context of the existing literature in political marketing and commercial market orientation....

  11. The equilibrium and oscillations of dust grains in a discharge

    International Nuclear Information System (INIS)

    Cramer, N.F.; Vladimirov, S.V.

    2000-01-01

    Full text: In a vertically oriented laboratory discharge plasma, dust particles are negatively charged and usually levitate in the sheath or pre-sheath region under the balance of gravitational, electrostatic (due to the sheath electric field) and plasma (such as the ion drag) forces. The ion flow, in addition to a direct (dragging) influence, is also responsible for the generation of associated collective plasma processes which can strongly affect the vertical arrangement of the grains, such as in the case of supersonic flows when a wake field is generated. Under some circumstances, the grains may form into a stable regular structure, the dust-plasma crystal, which can support a variety of lattice waves. The mechanism of formation of the crystal is still not well understood. The charge of the dust particles appears mainly due to electron and ion current onto the grain surfaces. The dependence of the dust particle charge on the sheath parameters has an important effect on the oscillations and equilibrium of dust grains in the vertical plane, leading to a possible disruption of the equilibrium position of the particle. Recent experiments at Sydney have shown the formation of the crystalline and liquid states of arrays of dust grains, and the self-excitation of vertical oscillations of the grains. To model these experiments, we have studied the interaction of dust grains with the plasma, including the charging of the grain, with a number of different models. A fluid model of the plasma to study the dust trapping, disruptions of the equilibrium, and the modes of transverse waves (vertically polarized) in arrays of grains in a dust-plasma crystal. It is found that for a grain radius greater than a critical value, there is no equilibrium position. Possible vertical oscillations about the stable equilibrium may develop high amplitudes, thus leading to a fall of the oscillating grain onto the electrode when the potential barrier is overcome. It is found that the charge

  12. Heterogeneous grain-scale response in ferroic polycrystals under electric field

    DEFF Research Database (Denmark)

    Daniels, John E.; Majkut, Marta; Cao, Qingua

    2016-01-01

    -ray diffraction (3D-XRD) is used to resolve the non-180° ferroelectric domain switching strain components of 191 grains from the bulk of a polycrystalline electro-ceramic that has undergone an electric-field-induced phase transformation. It is found that while the orientation of a given grain relative...... to the field direction has a significant influence on the phase and resultant domain texture, there are large deviations from the average behaviour at the grain scale. It is suggested that these deviations arise from local strain and electric field neighbourhoods being highly heterogeneous within the bulk...

  13. fMRI orientation decoding in V1 does not require global maps or globally coherent orientation stimuli.

    Science.gov (United States)

    Alink, Arjen; Krugliak, Alexandra; Walther, Alexander; Kriegeskorte, Nikolaus

    2013-01-01

    The orientation of a large grating can be decoded from V1 functional magnetic resonance imaging (fMRI) data, even at low resolution (3-mm isotropic voxels). This finding has suggested that columnar-level neuronal information might be accessible to fMRI at 3T. However, orientation decodability might alternatively arise from global orientation-preference maps. Such global maps across V1 could result from bottom-up processing, if the preferences of V1 neurons were biased toward particular orientations (e.g., radial from fixation, or cardinal, i.e., vertical or horizontal). Global maps could also arise from local recurrent or top-down processing, reflecting pre-attentive perceptual grouping, attention spreading, or predictive coding of global form. Here we investigate whether fMRI orientation decoding with 2-mm voxels requires (a) globally coherent orientation stimuli and/or (b) global-scale patterns of V1 activity. We used opposite-orientation gratings (balanced about the cardinal orientations) and spirals (balanced about the radial orientation), along with novel patch-swapped variants of these stimuli. The two stimuli of a patch-swapped pair have opposite orientations everywhere (like their globally coherent parent stimuli). However, the two stimuli appear globally similar, a patchwork of opposite orientations. We find that all stimulus pairs are robustly decodable, demonstrating that fMRI orientation decoding does not require globally coherent orientation stimuli. Furthermore, decoding remained robust after spatial high-pass filtering for all stimuli, showing that fine-grained components of the fMRI patterns reflect visual orientations. Consistent with previous studies, we found evidence for global radial and vertical preference maps in V1. However, these were weak or absent for patch-swapped stimuli, suggesting that global preference maps depend on globally coherent orientations and might arise through recurrent or top-down processes related to the perception of

  14. On the adaptivity gap of stochastic orienteering

    NARCIS (Netherlands)

    Bansal, N.; Nagarajan, V.

    2013-01-01

    The input to the stochastic orienteering problem consists of a budget $B$ and metric $(V,d)$ where each vertex $v$ has a job with deterministic reward and random processing time (drawn from a known distribution). The processing times are independent across vertices. The goal is to obtain a

  15. On the Adaptivity Gap of Stochastic Orienteering

    NARCIS (Netherlands)

    N. Bansal (Nikhil); V. Nagarajan

    2013-01-01

    htmlabstractThe input to the stochastic orienteering problem consists of a budget B and metric (V,d) where each vertex v has a job with deterministic reward and random processing time (drawn from a known distribution). The processing times are independent across vertices. The goal is to obtain a

  16. On the adaptivity gap of stochastic orienteering

    NARCIS (Netherlands)

    Bansal, N.; Nagarajan, V.; Lee, J.; Vygen, J.

    2014-01-01

    The input to the stochastic orienteering problem [14] consists of a budget B and metric (V,d) where each vertex v¿¿¿V has a job with a deterministic reward and a random processing time (drawn from a known distribution). The processing times are independent across vertices. The goal is to obtain a

  17. On the adaptivity gap of stochastic orienteering

    NARCIS (Netherlands)

    Bansal, N.; Nagarajan, V.

    2015-01-01

    The input to the stochastic orienteering problem (Gupta et al. in SODA, pp 1522–1538,  2012) consists of a budget B and metric (V, d) where each vertex(Formula presented.) has a job with a deterministic reward and a random processing time (drawn from a known distribution). The processing times are

  18. Orientation correlations in aluminium deformed by ECAE

    DEFF Research Database (Denmark)

    Bowen, Jacob R.; Mishin, Oleg; Prangnell, P.B.

    2002-01-01

    Distributions of boundary misorientations measured in an Al–0.13%Mg alloy, processed by equal channel angular extrusion to a von Mises effective strain of 10, have been compared to misorientation distributions generated from a random mix of orientations present in the microstructure. A significan...

  19. Semiconductor monolayer assemblies with oriented crystal faces

    KAUST Repository

    Ma, Guijun; Takata, Tsuyoshi; Katayama, Masao; Zhang, Fuxiang; Moriya, Yosuke; Takanabe, Kazuhiro; Kubota, Jun; Domen, Kazunari

    2012-01-01

    Fabrication of two-dimensional monolayers of crystalline oxide and oxynitride particles was attempted on glass plate substrates. X-Ray diffraction patterns of the assemblies show only specific crystal facets, indicative of the uniform orientation of the particles on the substrate. The selectivity afforded by this immobilization technique enables the organization of randomly distributed polycrystalline powders in a controlled manner.

  20. Initial porosity of random packing : Computer simulation of grain rearrangement

    NARCIS (Netherlands)

    Alberts, L.J.H.

    2005-01-01

    The initial porosity of clastic sediments is poorly defined. In spite of this, it is an important parameter in many models that describe the diagenetic processes taking place during the burial of sediments and which are responsible for the transition from sand to sandstone. Diagenetic models are of