WorldWideScience

Sample records for nonporous fine-grained ni-mn-ga

  1. Size effects on magnetic actuation in Ni-Mn-Ga shape-memory alloys.

    Science.gov (United States)

    Dunand, David C; Müllner, Peter

    2011-01-11

    The off-stoichiometric Ni(2)MnGa Heusler alloy is a magnetic shape-memory alloy capable of reversible magnetic-field-induced strains (MFIS). These are generated by twin boundaries moving under the influence of an internal stress produced by a magnetic field through the magnetocrystalline anisotropy. While MFIS are very large (up to 10%) for monocrystalline Ni-Mn-Ga, they are near zero (<0.01%) in fine-grained polycrystals due to incompatibilities during twinning of neighboring grains and the resulting internal geometrical constraints. By growing the grains and/or shrinking the sample, the grain size becomes comparable to one or more characteristic sample sizes (film thickness, wire or strut diameter, ribbon width, particle diameter, etc), and the grains become surrounded by free space. This reduces the incompatibilities between neighboring grains and can favor twinning and thus increase the MFIS. This approach was validated recently with very large MFIS (0.2-8%) measured in Ni-Mn-Ga fibers and foams with bamboo grains with dimensions similar to the fiber or strut diameters and in thin plates where grain diameters are comparable to plate thickness. Here, we review processing, micro- and macrostructure, and magneto-mechanical properties of (i) Ni-Mn-Ga powders, fibers, ribbons and films with one or more small dimension, which are amenable to the growth of bamboo grains leading to large MFIS, and (ii) "constructs" from these structural elements (e.g., mats, laminates, textiles, foams and composites). Various strategies are proposed to accentuate this geometric effect which enables large MFIS in polycrystalline Ni-Mn-Ga by matching grain and sample sizes.

  2. Damping of Ni-Mn-Ga epoxy resin composites

    Institute of Scientific and Technical Information of China (English)

    Wei Liang; He Yu; Liu Yufeng; Yang Naibin

    2013-01-01

    By combining the advantages of efficient damping and high mechanical properties, Ni-Mn-Ga particle composites have a very good prospect for applications in damping structure design. In this paper, a ferromagnetic shape memory alloy Ni-Mn-Ga composite is prepared. Ni-Mn-Ga particle/bisphenol-A epoxy composite cantilever beam vibration tests under a magnetic field and without the magnetic field are conducted to analyze the structural damping ratios n. Meanwhile, the damping characteristics of the Ni-Mn-Ga composite are studied through the axial loading-unloading method and the acoustic emission signals method. The damping coefficient of the composite for different Ni-Mn-Ga volume fractions is obtained. The interface properties of the composite are discussed by micro examination and axial loading. The relationships between the damping of the composite and that of the component materials are discussed. The specific damping capacity (SDC) and acoustic emission counts diagram of different specimens with different Ni-Mn-Ga volume fractions are analyzed.

  3. Dislocation Mechanism of Twinning in Ni-Mn-Ga

    Science.gov (United States)

    Zárubová, N.; Ge, Y.; Gemperlová, J.; Gemperle, A.; Hannula, S.-P.

    2012-03-01

    Tensile tests were performed in situ in a transmission electron microscope to investigate the twinning mechanism in non-modulated Ni-Mn-Ga martensite. The reorientation of the twin variants occurs via twinning dislocations. Their generation and movement were followed; the glide plane and Burgers vector were verified. Individual twinning dislocations were visualized.

  4. The ferromagnetic shape-memory effect in Ni Mn Ga

    Science.gov (United States)

    Marioni, M. A.; O'Handley, R. C.; Allen, S. M.; Hall, S. R.; Paul, D. I.; Richard, M. L.; Feuchtwanger, J.; Peterson, B. W.; Chambers, J. M.; Techapiesancharoenkij, R.

    2005-04-01

    Active materials have long been used in the construction of sensors and devices. Examples are piezo-electric ceramics and shape memory alloys. The more recently developed ferromagnetic shape-memory alloys (FSMAs) have received considerable attention due to their large magnetic field-induced, reversible strains (up to 10%). In this article, we review the basic physical characteristics of the FSMA Ni-Mn-Ga (crystallography, thermal, mechanical and magnetic behavior). Also, we present some of the works currently under way in the areas of pulse-field and acoustic-assisted actuation, and vibration energy absorption.

  5. NiMnGa/Si Shape Memory Bimorph Nanoactuation

    Science.gov (United States)

    Lambrecht, Franziska; Lay, Christian; Aseguinolaza, Iván R.; Chernenko, Volodymyr; Kohl, Manfred

    2016-12-01

    The size dependences of thermal bimorph and shape memory effect of nanoscale shape memory alloy (SMA)/Si bimorph actuators are investigated in situ in a scanning electron microscope and by finite element simulations. By combining silicon nanomachining and magnetron sputtering, freestanding NiMnGa/Si bimorph cantilever structures with film/substrate thickness of 200/250 nm and decreasing lateral dimensions are fabricated. Electrical resistance and mechanical beam bending tests upon direct Joule heating demonstrate martensitic phase transformation and reversible thermal bimorph effect, respectively. Corresponding characteristics are strongly affected by the large temperature gradient in the order of 50 K/µm forming along the nano bimorph cantilever upon electro-thermal actuation, which, in addition, depends on the size-dependent heat conductivity in the Si nano layer. Furthermore, the martensitic transformation temperatures show a size-dependent decrease by about 40 K for decreasing lateral dimensions down to 200 nm. The effects of heating temperature and stress distribution on the nanoactuation performance are analyzed by finite element simulations revealing thickness ratio of SMA/Si of 90/250 nm to achieve an optimum SME. Differential thermal expansion and thermo-elastic effects are discriminated by comparative measurements and simulations on Ni/Si bimorph reference actuators.

  6. Martensitic transformation in NiMnGa/Si bimorph nanoactuators with ultra-low hysteresis

    Science.gov (United States)

    Lambrecht, F.; Sagardiluz, N.; Gueltig, M.; Aseguinolaza, I. R.; Chernenko, V. A.; Kohl, M.

    2017-05-01

    We report on the fabrication and in-situ characterization of temperature-dependent electrical resistance and deflection characteristics of free-standing NiMnGa/Si bimorph cantilevers with a NiMnGa layer thickness of 200 nm and a minimum lateral width of 50 nm. The martensitic transformation in the initial NiMnGa/Si bimorph films and nanomachined NiMnGa/Si bimorph cantilevers proceeds in a wide temperature range with a hardly detectable temperature hysteresis width below 1 K. This remarkable behavior is ascribed to the internal stress in the bimorph system that exceeds the stress limit of the critical point terminating the stress-temperature phase diagram as it is known for ferromagnetic shape memory alloys. Temperature-dependent deflection characteristics reveal a competition between the bimorph effect and the shape memory effect, causing beam deflection in opposite directions. The observation of the shape memory effect strongly depends on the NiMnGa/Si thickness ratio, causing a maximum deflection change per beam length of 3% in agreement with finite element simulations.

  7. Magnetic and mechanical properties of Ni-Mn-Ga/Fe-Ga ferromagnetic shape memory composite

    Science.gov (United States)

    Tan, Chang-Long; Zhang, Kun; Tian, Xiao-Hua; Cai, Wei

    2015-05-01

    A ferromagnetic shape memory composite of Ni-Mn-Ga and Fe-Ga was fabricated by using spark plasma sintering method. The magnetic and mechanical properties of the composite were investigated. Compared to the Ni-Mn-Ga alloy, the threshold field for magnetic-field-induced strain in the composite is clearly reduced owing to the assistance of internal stress generated from Fe-Ga. Meanwhile, the ductility has been significantly improved in the composite. A fracture strain of 26% and a compressive strength of 1600 MPa were achieved. Projects supported by the National Natural Science Foundation of China (Grant Nos. 51271065 and 51301054), the Program for New Century Excellent Talents in Heilongjiang Provincial Education Department, China (Grant No. 1253-NCET-009), the Youth Academic Backbone in Heilongjiang Provincial Education Department, China (Grant No. 1251G022), the Projects of Heilongjiang, China, and China Postdoctoral Science Foundation.

  8. Effects of Sm on Phase Transformation in Ni-Mn-Ga Alloys

    Institute of Scientific and Technical Information of China (English)

    郭世海; 张羊换; 赵增祺; 祁焱; 全白云; 王新林

    2004-01-01

    The effects of small amount additions of Sm on the martensitic transition and magnetic phase transition of polycrystalline Ni-Mn-Ga alloys were investigated. The experimental results show that the Sm doped alloys also undergo a thermal-elastic martensitic transformation and reverse transformation during cooling and heating process and the addition of Sm decreases the martensitic transformation temperature and Curie temperature in different degree respectively. Ni-Mn-Ga alloys of adding Sm still possess Heusler structure, but their crystal lattice parameters are modified slightly. The addition of a proper amount of Sm does not basically decrease Tc of the alloy when avoiding the appearance of second phase. In addition, the doped alloys have favorable toughness because of grain refinement of Sm.

  9. Crack growth of 10M Ni-Mn-Ga material in cyclic mechanical loading

    Science.gov (United States)

    Aaltio, I.; Ge, Y.; Pulkkinen, H.; Sjöberg, A.; Söderberg, O.; Liu, X. W.; Hannula, S.-P.

    The 10M martensitic Ni-Mn-Ga single crystal materials are usually applied in the magneto-mechanical actuators. Therefore, it is important to know the possible effect of the long-term cyclic shape changes on their structure and behavior. This can be evaluated with the mechanical fatigue testing. In the present study, the single crystal 10M Ni-Mn-Ga samples of different compositions were applied to strain-controlled uniaxial mechanical cycling in the multivariant state at ambient temperature. The experiments revealed distinctive changes of the twin variant structure, especially in the mobile twin area, density of twin boundaries, and in the tendency for fatigue crack growth. Characterization of the crack surface showed that the cracks in the microscale grow in a step-wise manner on specific crystallographic planes, i.e, twin boundary planes, but that the macroscopic crack does not occur only along crystallographic directions.

  10. An efficient control of Curie temperature $T_C$ in Ni-Mn-Ga alloys

    OpenAIRE

    Khovailo, V. V.; Chernenko, V. A.; Cherechukin, A. A.; Takagi, T.; Abe, T.

    2003-01-01

    We have studied the influence of alloying with a fourth element on the temperature of ferromagnetic ordering $T_C$ in Ni-Mn-Ga Heusler alloys. It is found that $T_C$ increases or decreases, depending on the substitution. The increase of $T_C$ is observed when Ni is substituted by either Fe or Co. On the contrary, the substitution of Mn for V or Ga for In strongly reduces $T_C$.

  11. Ab initio study of the composite phase diagram of Ni-Mn-Ga shape memory alloys

    Science.gov (United States)

    Sokolovskaya, Yu. A.; Sokolovskiy, V. V.; Zagrebin, M. A.; Buchelnikov, V. D.; Zayak, A. T.

    2017-07-01

    The magnetic and structural properties of a series of nonstoichiometric Ni-Mn-Ga Heusler alloys are theoretically investigated in terms of the density functional theory. Nonstoichiometry is formed in the coherent potential approximation. Concentration dependences of the equilibrium lattice parameter, the bulk modulus, and the total magnetic moment are obtained and projected onto the ternary phase diagram of the alloys. The stable crystalline structures and the magnetic configurations of the austenitic phase are determined.

  12. Autonomous generator based on Ni-Mn-Ga microactuator as a frequency selective element

    Directory of Open Access Journals (Sweden)

    Barandiaran J.M.

    2013-01-01

    Full Text Available In this work, we suggest the temperature-induced resistivity change at the martensitic transformation in the Ni-Mn-Ga ferromagnetic shape memory alloy as a driving mechanism enabling periodic signal generation. We demonstrated its practical importance by a design of the prototype of a low-frequency autonomous generator. A prominent feature of this new generator is a control of its frequency by the external magnetic field.

  13. Influence of volume magnetostriction on the thermodynamic properties of Ni-Mn-Ga shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kosogor, Anna [National University of Science and Technology “MISiS,” Moscow 119049 (Russian Federation); Institute of Magnetism, 36-b, Vernadsky Str., Kyiv 03142 (Ukraine); Donetsk Institute for Physics and Engineering, Kyiv 03028 (Ukraine); L' vov, Victor A. [Institute of Magnetism, 36-b, Vernadsky Str., Kyiv 03142 (Ukraine); Faculty of Radiophysics, Electronics and Computer Systems, Taras Shevchenko University, Glushkov Str. 4G, Kyiv 01601 (Ukraine); Departament de Fisica, Universitat de les Illes Balears, Ctra. de Valldemossa, km 7.5, 07122 Palma de Mallorca (Spain); Cesari, Eduard [Departament de Fisica, Universitat de les Illes Balears, Ctra. de Valldemossa, km 7.5, 07122 Palma de Mallorca (Spain)

    2015-10-07

    In the present article, the thermodynamic properties of Ni-Mn-Ga ferromagnetic shape memory alloys exhibiting the martensitic transformations (MTs) above and below Curie temperature are compared. It is shown that when MT goes below Curie temperature, the elastic and thermal properties of alloy noticeably depend on magnetization value due to spontaneous volume magnetostriction. However, the separation of magnetic parts from the basic characteristics of MT is a difficult task, because the volume magnetostriction does not qualitatively change the transformational behaviour of alloy. This problem is solved for several Ni-Mn-Ga alloys by means of the quantitative theoretical analysis of experimental data obtained in the course of stress-strain tests. For each alloy, the entropy change and the transformation heat evolved in the course of MT are evaluated, first, from the results of stress-strain tests and, second, from differential scanning calorimetry data. For all alloys, a quantitative agreement between the values obtained in two different ways is observed. It is shown that the magnetic part of transformation heat exceeds the non-magnetic one for the Ni-Mn-Ga alloys undergoing MTs in ferromagnetic state, while the elevated values of transformation heat measured for the alloys undergoing MTs in paramagnetic state are caused by large MT strains.

  14. Influence of volume magnetostriction on the thermodynamic properties of Ni-Mn-Ga shape memory alloys

    Science.gov (United States)

    Kosogor, Anna; L'vov, Victor A.; Cesari, Eduard

    2015-10-01

    In the present article, the thermodynamic properties of Ni-Mn-Ga ferromagnetic shape memory alloys exhibiting the martensitic transformations (MTs) above and below Curie temperature are compared. It is shown that when MT goes below Curie temperature, the elastic and thermal properties of alloy noticeably depend on magnetization value due to spontaneous volume magnetostriction. However, the separation of magnetic parts from the basic characteristics of MT is a difficult task, because the volume magnetostriction does not qualitatively change the transformational behaviour of alloy. This problem is solved for several Ni-Mn-Ga alloys by means of the quantitative theoretical analysis of experimental data obtained in the course of stress-strain tests. For each alloy, the entropy change and the transformation heat evolved in the course of MT are evaluated, first, from the results of stress-strain tests and, second, from differential scanning calorimetry data. For all alloys, a quantitative agreement between the values obtained in two different ways is observed. It is shown that the magnetic part of transformation heat exceeds the non-magnetic one for the Ni-Mn-Ga alloys undergoing MTs in ferromagnetic state, while the elevated values of transformation heat measured for the alloys undergoing MTs in paramagnetic state are caused by large MT strains.

  15. Correlation of martensitic transformation temperatures of Ni- Mn-Ga/Al-X alloys to non-bonding electron concentration

    Science.gov (United States)

    Ramudu, M.; Satish Kumar, A.; Seshubai, V.; Rajasekharan, T.

    2015-02-01

    The martensitic transformation TM of the alloys of Ni-Mn-Ga and Ni-Mn-Al show a general trend of increase with electron per atom ratio (e/a) calculated from the total number of electrons outside the rare gas shell of the atoms. However prediction of TM fails among iron substituted Ni-Mn-Ga alloys and those with In doped for Ga, due to the absence of a useful trend. A scheme of computing modified electron concentration is presented considering only the non-bonding electrons per atom Ne/a of the compounds, based on Pauling's ideas on the electronic structure of metallic elements. Systematic variation of TM with Ne/a is reproduced for a large number of alloys of Ni-Mn-Ga and the anomaly observed for Fe containing alloys with e/a disappears. The non-bonding electron concentration is thus demonstrated to be effective in predicting TM of shape memory alloys of Ni-Mn-Ga-X system including the isoelectronic compounds of Ni-Mn-Ga-In.

  16. Combined caloric effects in a multiferroic Ni-Mn-Ga alloy with broad refrigeration temperature region

    Science.gov (United States)

    Hu, Yong; Li, Zongbin; Yang, Bo; Qian, Suxin; Gan, Weimin; Gong, Yuanyuan; Li, Yang; Zhao, Dewei; Liu, Jian; Zhao, Xiang; Zuo, Liang; Wang, Dunhui; Du, Youwei

    2017-04-01

    Solid-state refrigeration based on the caloric effects is promising to replace the traditional vapor-compressing refrigeration technology due to environmental protection and high efficiency. However, the narrow working temperature region has hindered the application of these refrigeration technologies. In this paper, we propose a method of combined caloric, through which a broad refrigeration region can be realized in a multiferroic alloy, Ni-Mn-Ga, by combining its elastocaloric and magnetocaloric effects. Moreover, the materials' efficiency of elastocaloric effect has been greatly improved in our sample. These results illuminate a promising way to use multiferroic alloys for refrigeration with a broad refrigeration temperature region.

  17. Martensitic transformation in Cu-doped NiMnGa magnetic shape memory alloys

    Institute of Scientific and Technical Information of China (English)

    Li Pan-Pan; Wang Jing-Min; Jiang Cheng-Bao

    2011-01-01

    This paper studies the martensitic transformation in the Cu-doped NiMnGa alloys. The orthorhombic martensite transforms to L21 cubic austenite by Cu substituting for Ni in the Ni50-x:CuxMn31Ga19 (x=2-10) alloys, the martensitic transformation temperature decreases significantly with the rate of 40 K per Cu atom addition. The variation of the Fermi sphere radius (kF) is applied to evaluate the change of the martensitic transformation temperature. The increase of kF leads to the increase of the martensitic transformation temperature.

  18. Experimental Study on Characteristics of NiMnGa Magnetically Controlled Shape Memory Alloy

    Institute of Scientific and Technical Information of China (English)

    Fengxiang WANG; Wenjun LI; Qingxin ZHANG; Chenxi LI; Xinjie WU

    2006-01-01

    The static and dynamic magnetic controlling characteristics of NiMnGa magnetically controlled shape memory alloy (MSMA) were experimentally studied. The results show that the characteristics of induced strain with respect to the magnetic field are nonlinear with saturation nature, and dependent on the temperature as well as the load applied to the MSMA. The magnetic shape memory effect can be observed only in complete martensite phase at room temperature. The magnetic permeability of MSMA is not constant and reduces with the increment of magnetic field. The relative saturation magnetic permeability of MSMA is about 1.5.

  19. Transformation and Field-Induced Strains in as-Cast Ni-Mn-Ga Alloy

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wei-ren; LI Jian-liang; QI Yan; ZHANG Yang-huan; WANG Xin-lin; YU Yuan-jun

    2004-01-01

    The characteristics of the strains induced by transformation and magnetic field in as-cast Ni-Mn-Ga alloy were systematically investigated. It is found that internal stress and texture introduced during casting bring the anisotropy of temperature-induced strains. However, no anisotropy of field-induced strains is induced, and the internal stress and the texture modulate only the temperature dependence of field-induced strains. Large retardance of field-induced strains was observed, which indicates the rearrangement of martensitic variants as a competition process between the stress energy and Zeeman energy. The non-continuous field dependence of strain indicates the unstable microstructure during martensitic transformation.

  20. Magnetic domain evolution with applied field in a Ni-Mn-Ga magnetic shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ge Yanling [Laboratory of Materials Science, Helsinki University of Technology, P.O. Box 6200, FI-02015 TKK (Finland)]. E-mail: Yanling.Ge@tkk.fi; Heczko, Oleg [Laboratory of Materials Science, Helsinki University of Technology, P.O. Box 6200, FI-02015 TKK (Finland); Soederberg, Outi [Laboratory of Materials Science, Helsinki University of Technology, P.O. Box 6200, FI-02015 TKK (Finland); Hannula, Simo-Pekka [Laboratory of Materials Science, Helsinki University of Technology, P.O. Box 6200, FI-02015 TKK (Finland)

    2006-06-15

    The evolution of a magnetic domain pattern with an applied field in two perpendicular directions was studied in a Ni-Mn-Ga magnetic shape memory alloy by means of optical and scanning electron microscopy (SEM). The optical contrast of magnetic domains arises from surface undulation. This surface relief is coherent at the (1 0 1) twin boundary. However, the surface relief causes the trace of the (0 1 1) twin boundary to follow a zigzag pattern. These optical observationre confirmed by SEM Type II magnetic contrast.

  1. Twinning in shear and uniaxial loading in five layered martensite Ni-Mn-Ga single crystals

    Science.gov (United States)

    Aaltio, Ilkka; Ge, Yanling; Hannula, Simo-Pekka

    2013-02-01

    Five-layered martensite Ni-Mn-Ga single crystals are known for their exceptionally mobile twin boundaries allowing a shape change under mechanical stress and by magnetic field. The mechanically measured twinning stress has usually been studied in uniaxial mode, however the twinning and detwinning is generally accepted to be resulted by the shear component. We have studied the twinning behavior at uniaxial and shear stress. In addition we have applied the shear stress at different angles in relation to the expected twinning direction [ {10bar 1} ]. The results show that the onset of twinning lays at similar stress levels in both uniaxial and shear modes.

  2. Direct optical observation of magnetic domains in Ni-Mn-Ga martensite

    Science.gov (United States)

    Ge, Y.; Heczko, O.; Söderberg, O.; Hannula, S.-P.

    2006-08-01

    This letter reports the direct optical observation, i.e., without polarization, of the magnetic domain structure explained by a large surface relief in Ni-Mn-Ga martensite. The authors suggest that the relief is due to the different straining of the surface and the bulk caused by the internal stresses associated with the magnetic shape memory effect. As a result of the relief the projection of the (011) twin traces upon the (010) plane creates the observed zigzag pattern. The surface tilt angle calculated from the zigzag pattern is ˜3°.

  3. Biocorrosion investigation of two shape memory nickel based alloys: Ni-Mn-Ga and thin film NiTi.

    Science.gov (United States)

    Stepan, L L; Levi, D S; Gans, E; Mohanchandra, K P; Ujihara, M; Carman, G P

    2007-09-01

    Thin film nitinol and single crystal Ni-Mn-Ga represent two new shape memory materials with potential to be used as percutaneously placed implant devices. However, the biocompatibility of these materials has not been adequately assessed. Immersion tests were conducted on both thin film nitinol and single crystal Ni-Mn-Ga in Hank's balanced salt solution at 37 degrees C and pH 7.4. After 12 h, large pits were found on the Ni-Mn-Ga samples while thin film nitinol displayed no signs of corrosion. Further electrochemical tests on thin film nitinol samples revealed breakdown potentials superior to a mechanically polished nitinol disc. These results suggest that passivation or electropolishing of thin film nitinol maybe unnecessary to promote corrosion resistance.

  4. Microstructural, phase transformation and magnetic properties of Ni-Mn-Ga alloy fabricated by spark plasma sintering

    Institute of Scientific and Technical Information of China (English)

    Tian Xiao-Hua; Sui Jie-He; Zhang Xin; Feng Xue; Cai Wei

    2011-01-01

    The microstructural, phase transformation and magnetic properties of Ni-Mn-Ga alloy fabricated using the spark plasma sintering method have been investigated. The results show that both the as-sintered and annealed sintered specimens exhibit typical martensitic transformation behaviours. The martensite of the sintered specimen after annealing exhibits a ferromagnetic nature. Moreover, study of the fracture surface indicates that the transgranular fracture contributes to the higher ductility of sintered Ni-Mn-Ga alloy. In addition, the transformation strain in sintered Ni-Mn-Gaalloy is studied for the first time.

  5. Macroscopic inhomogeneous deformation behavior arising in single crystal Ni-Mn-Ga foils under tensile loading

    Science.gov (United States)

    Murasawa, Go; Yeduru, Srinivasa R.; Kohl, Manfred

    2016-12-01

    This study investigated macroscopic inhomogeneous deformation occurring in single-crystal Ni-Mn-Ga foils under uniaxial tensile loading. Two types of single-crystal Ni-Mn-Ga foil samples were examined as-received and after thermo-mechanical training. Local strain and the strain field were measured under tensile loading using laser speckle and digital image correlation. The as-received sample showed a strongly inhomogeneous strain field with intermittence under progressive deformation, but the trained sample result showed strain field homogeneity throughout the specimen surface. The as-received sample is a mainly polycrystalline-like state composed of the domain structure. The sample contains many domain boundaries and large domain structures in the body. Its structure would cause large local strain band nucleation with intermittence. However, the trained one is an ideal single-crystalline state with a transformation preferential orientation of variants after almost all domain boundary and large domain structures vanish during thermo-mechanical training. As a result, macroscopic homogeneous deformation occurs on the trained sample surface during deformation.

  6. Epitaxial Ni-Mn-Ga-Co thin films on PMN-PT substrates for multicaloric applications

    Energy Technology Data Exchange (ETDEWEB)

    Schleicher, B., E-mail: b.schleicher@ifw-dresden.de; Niemann, R.; Schultz, L.; Fähler, S. [IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden (Germany); TU Dresden, Institute for Solid State Physics, D-01062 Dresden (Germany); Diestel, A.; Hühne, R. [IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden (Germany)

    2015-08-07

    Multicaloric stacks consisting of a magnetocaloric film on a piezoelectric substrate promise improved caloric properties as the transition temperature can be controlled by both magnetic and electric fields. We present epitaxially grown magnetocaloric Ni-Mn-Ga-Co thin films on ferroelectric Pb(Mg{sub 1/3}Nb{sub 2/3}){sub 0.72}Ti{sub 0.28}O{sub 3} substrates. Structure and microstructure of two samples, being in the austenitic and martensitic state at room temperature, are investigated by X-ray diffraction in two- and four-circle geometry and by atomic force microscopy. In addition, high temperature magnetometry was performed on the latter sample. The combination of these methods allows separating the influence of epitaxial growth and martensitic transformation. A preferential alignment of twin boundaries is observed already in the as-deposited state, which indicates the presence of prestress, without applying an electric field to the substrate. A temperature-magnetic field phase diagram is presented, which demonstrates the inverse magnetocaloric effect of the epitaxial Ni-Mn-Ga-Co film.

  7. Epitaxial Ni-Mn-Ga-Co thin films on PMN-PT substrates for multicaloric applications

    Science.gov (United States)

    Schleicher, B.; Niemann, R.; Diestel, A.; Hühne, R.; Schultz, L.; Fähler, S.

    2015-08-01

    Multicaloric stacks consisting of a magnetocaloric film on a piezoelectric substrate promise improved caloric properties as the transition temperature can be controlled by both magnetic and electric fields. We present epitaxially grown magnetocaloric Ni-Mn-Ga-Co thin films on ferroelectric Pb(Mg1/3Nb2/3)0.72Ti0.28O3 substrates. Structure and microstructure of two samples, being in the austenitic and martensitic state at room temperature, are investigated by X-ray diffraction in two- and four-circle geometry and by atomic force microscopy. In addition, high temperature magnetometry was performed on the latter sample. The combination of these methods allows separating the influence of epitaxial growth and martensitic transformation. A preferential alignment of twin boundaries is observed already in the as-deposited state, which indicates the presence of prestress, without applying an electric field to the substrate. A temperature-magnetic field phase diagram is presented, which demonstrates the inverse magnetocaloric effect of the epitaxial Ni-Mn-Ga-Co film.

  8. Transformation twinning of Ni-Mn-Ga characterized with temperature-controlled atomic force microscopy.

    Science.gov (United States)

    Reinhold, Matthew; Watson, Chad; Knowlton, William B; Müllner, Peter

    2010-06-01

    The magnetomechanical properties of ferromagnetic shape memory alloy Ni-Mn-Ga single crystals depend strongly on the twin microstructure, which can be modified through thermomagnetomechanical training. Atomic force microscopy (AFM) and magnetic force microscopy (MFM) were used to characterize the evolution of twin microstructures during thermomechanical training of a Ni-Mn-Ga single crystal. Experiments were performed in the martensite phase at 25 degrees C and in the austenite phase at 55 degrees C. Two distinct twinning surface reliefs were observed at room temperature. At elevated temperature (55 degrees C), the surface relief of one twinning mode disappeared while the other relief remained unchanged. When cooled back to 25 degrees C, the twin surface relief recovered. The relief persisting at elevated temperature specifies the positions of twin boundaries that were present when the sample was polished prior to surface characterization. AFM and MFM following thermomechanical treatment provide a nondestructive method to identify the crystallographic orientation of each twin and of each twin boundary plane. Temperature dependent AFM and MFM experiments reveal the twinning history thereby establishing the technique as a unique predictive tool for revealing the path of the martensitic and reverse transformations of magnetic shape memory alloys.

  9. An x-ray absorption spectroscopy study of Ni-Mn-Ga shape memory alloys.

    Science.gov (United States)

    Sathe, V G; Dubey, Aditi; Banik, Soma; Barman, S R; Olivi, L

    2013-01-30

    The austenite to martensite phase transition in Ni-Mn-Ga ferromagnetic shape memory alloys was studied by extended x-ray absorption fine structure (EXAFS) and x-ray absorption near-edge structure (XANES) spectroscopy. The spectra at all the three elements', namely, Mn, Ga and Ni, K-edges in several Ni-Mn-Ga samples (with both Ni and Mn excess) were analyzed at room temperature and low temperatures. The EXAFS analysis suggested a displacement of Mn and Ga atoms in opposite direction with respect to the Ni atoms when the compound transforms from the austenite phase to the martensite phase. The first coordination distances around the Mn and Ga atoms remained undisturbed on transition, while the second and subsequent shells showed dramatic changes indicating the presence of a modulated structure. The Mn rich compounds showed the presence of antisite disorder of Mn and Ga. The XANES results showed remarkable changes in the unoccupied partial density of states corresponding to Mn and Ni, while the electronic structure of Ga remained unperturbed across the martensite transition. The post-edge features in the Mn K-edge XANES spectra changed from a double peak like structure to a flat peak like structure upon phase transition. The study establishes strong correlation between the crystal structure and the unoccupied electronic structure in these shape memory alloys.

  10. Magnetic-Field-Induced Strains of Bonded Ni-Mn-Ga Melt-Spun Ribbons

    Institute of Scientific and Technical Information of China (English)

    QUO Shi-Hai; ZHANG Yang-Huan; LI Jian-Liang; QI Yan; QUAN Bai-Yun; WANG Xin-Lin

    2006-01-01

    Non-stoichiometric Ni50Mn27Ga23 polycrystalline ribbons are prepared by melt-spinning technique. The magnetic-field-induced strain (MFIS) of Ni-Mn-Ga bulk alloy prepared by bonding the melt-spun ribbons is obtained. The experimental results show that Ni50Mn27Ga23 bonded ribbons exhibit a typical thermal-elastic shape memory effect in the thickness direction. The martensitic transformation strain of bonded ribbons is an expansive strain of about 0.3% without the magnetic fieid and a contractive strain of about -0.46% at the magnetic field of 1T. The field can not only enhance the value of the martensitic transformation strain of the bonded ribbons, but can also change the direction of the strain. The bonded ribbons alloy presents negative MFIS and obtains a larger value of the strain though influenced by the adhesive between the ribbons. Therefore, the preparation technique of the Ni-Mn-Ga bulk alloy by bonding melt-spun ribbons is helpful to get rid of the size restriction of the ribbon and to broaden the applications of the ribbons.

  11. COMPOSITION TRIANGLE DIAGRAMS OF Ni-Mn-Ga MAGNETIC SHAPE MEMORY ALLOYS

    Institute of Scientific and Technical Information of China (English)

    Y.F. Wang; J.M. Wang; C.B. Jiang; H.B. Xu

    2006-01-01

    A statistical work has been done to collect the composition ranges of Ni-Mn-Ga alloys exhibiting different structures and martensite start temperature (Ms), large magnetostrain or the co-existence of magnetic and structural transitions. The alloys with five-layered ( 5M), seven-layered(7M) modulated and non-modulated (T) martensitic structures were mapped in the graph. An empirical formula has been presented to reflect the effect of elements nickel (Ni), manganese (Mn)and gallium (Ga), on the martensite start temperature (Ms). The martensitic structure is sensitive to the composition and the martensitic transformation temperature is most drastically affected by the Ni content. The alloys with large magnetostrain or co-existence effect of the magnetic and structural transitions were also listed in a limited area.

  12. Non-Modulated Martensite Microstructure With Internal Nanotwins In Ni-Mn-Ga Alloys

    Directory of Open Access Journals (Sweden)

    Szczerba M.J.

    2015-09-01

    Full Text Available The self-accommodated non-modulated martensite of Ni-Mn-Ga single crystal was studied by transmission and scanning electron microscopy in the latter case using the electron backscatter diffraction technique. Three kinds of interfaces existing at different length scales were reported. The first, is the wavy and incoherent interface separating martensite variants observed on the micro-level with no-common crystallographic plane between them. The second is within a single martensite plate where the lattice rotates around one of the {110} pole to accommodate the interfacial curvature between martensite plates. Finally, at the nanoscale the third interface exists, a twin boundary separating internal nanotwins with the {112} type habit plane.

  13. Investigation of magnetic domains in Ni Mn Ga alloys with a scanning electron microscope

    Science.gov (United States)

    Ge, Y.; Heczko, O.; Söderberg, O.; Hannula, S.-P.; Lindroos, V. K.

    2005-10-01

    The magnetic domains of martensite have been investigated with a scanning electron microscope in three Ni-Mn-Ga alloys with five-layered, seven-layered and non-layered (T) martensite structure. Type I magnetic contrast provides an overview of the domain pattern. This contrast arises from the stray field of the specimen and it is observed in a secondary-electron image. The type II magnetic contrast of a backscattered electron image gives the detailed magnetic microstructure together with the crystal morphology. A stripe domain pattern is formed in all the alloys when there is one dominant martensite variant in the sample. The second minor variant might be distorted due to interaction with the magnetic domain structure of the major variant. The mechanism of the deformation is not entirely clear and a tentative explanation for this deformation is suggested.

  14. Comparison of different methods for studying magnetic domains in Ni-Mn-Ga martensites

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Y. [Helsinki University of Technology, Laboratory of Materials Science, P.O. Box 6200 FI-02015 TKK (Finland)], E-mail: Yanling.ge@tkk.fi; Heczko, O.; Soederberg, O.; Hannula, S.-P. [Helsinki University of Technology, Laboratory of Materials Science, P.O. Box 6200 FI-02015 TKK (Finland)

    2008-05-25

    The relationship between magnetic domains and martensite twin structure was studied in selected Ni-Mn-Ga alloys. Optical microscopy, scanning electron microscopy (SEM) and magnetic force microscopy were used for studying the magnetic domains and the morphology of the martensitic microstructure. SEM Type-I magnetic domain contrast was consistent with the contrast obtained from magneto-optical indicator, as both contrasts originate from the stray field above the sample surface. SEM Type-II magnetic contrast in the backscattered electron (BE) image can display, apart from the martensitic twinning structure, both the magnetic domain contrast and the domain wall contrast. Therefore, the coupling of magnetic and twin structures can be evaluated from the BE image. Surprisingly, optical non-polarizing microscopy can reveal the domain contrast, too. This contrast is due to the surface relief associated with the magnetic domains.

  15. Temperature dependence of the damping properties of Ni-Mn-Ga alloys

    Energy Technology Data Exchange (ETDEWEB)

    Aaltio, I. [Laboratory of Materials Science, Helsinki University of Technology, Vuorimiehentie 2A, P.O. Box 6200, FI-02015 TKK, Espoo (Finland)], E-mail: ilkka.aaltio@tkk.fi; Lahelin, M. [Laboratory of Polymer Technology, Helsinki University of Technology, Kemistintie 1, P.O. Box 6100, FI-02015 TKK, Espoo (Finland); Soederberg, O.; Heczko, O. [Laboratory of Materials Science, Helsinki University of Technology, Vuorimiehentie 2A, P.O. Box 6200, FI-02015 TKK, Espoo (Finland); Loefgren, B. [Laboratory of Polymer Technology, Helsinki University of Technology, Kemistintie 1, P.O. Box 6100, FI-02015 TKK, Espoo (Finland); Ge, Y. [Laboratory of Materials Science, Helsinki University of Technology, Vuorimiehentie 2A, P.O. Box 6200, FI-02015 TKK, Espoo (Finland); Seppaelae, J. [Laboratory of Polymer Technology, Helsinki University of Technology, Kemistintie 1, P.O. Box 6100, FI-02015 TKK, Espoo (Finland); Hannula, S.-P. [Laboratory of Materials Science, Helsinki University of Technology, Vuorimiehentie 2A, P.O. Box 6200, FI-02015 TKK, Espoo (Finland)

    2008-05-25

    Single-crystalline 5M (exhibiting magnetic shape memory effect) and non-modulated martensitic Ni-Mn-Ga alloys were studied by dynamic mechanical analysis (DMA) at different temperatures. The chemical compositions of the alloys were determined using energy-dispersive X-ray spectrometry in a scanning electron microscope. The crystal structures were confirmed with X-ray diffraction and the transformation temperatures were measured. DMA measurements showed that the mechanical modulus (stiffness) and damping capacity increased during heating and a clear peak of the loss angle, was detected which is related to the reverse phase transformation of martensite to austenite. During cooling, there is a corresponding peak related to the martensite reaction. Significant decrease of the damping capacity occurs during transformation to austenite. Enhanced damping in the martensitic phase can be attributed to the mobility of twin boundaries.

  16. A discrete twin-boundary approach for simulating the magneto-mechanical response of Ni-Mn-Ga

    Science.gov (United States)

    Faran, Eilon; Shilo, Doron

    2016-09-01

    The design and optimization of ferromagnetic shape memory alloys (FSMA)-based devices require quantitative understanding of the dynamics of twin boundaries within these materials. Here, we present a discrete twin boundary modeling approach for simulating the behavior of an FSMA Ni-Mn-Ga crystal under combined magneto-mechanical loading conditions. The model is based on experimentally measured kinetic relations that describe the motion of individual twin boundaries over a wide range of velocities. The resulting calculations capture the dynamic response of Ni-Mn-Ga and reveal the relations between fundamental material parameters and actuation performance at different frequencies of the magnetic field. In particular, we show that at high field rates, the magnitude of the lattice barrier that resists twin boundary motion is the important property that determines the level of actuation strain, while the contribution of twinning stress property is minor. Consequently, type II twin boundaries, whose lattice barrier is smaller compared to type I, are expected to show better actuation performance at high rates, irrespective of the differences in the twinning stress property between the two boundary types. In addition, the simulation enables optimization of the actuation strain of a Ni-Mn-Ga crystal by adjusting the magnitude of the bias mechanical stress, thus providing direct guidelines for the design of actuating devices. Finally, we show that the use of a linear kinetic law for simulating the twinning-based response is inadequate and results in incorrect predictions.

  17. Transformation behavior of Ni-Mn-Ga in the low-temperature limit.

    Science.gov (United States)

    Pérez-Landazábal, J I; Recarte, V; Sánchez-Alarcos, V; Chernenko, V A; Barandiarán, J M; Lázpita, P; Rodriguez Fernández, J; Righi, L

    2012-07-11

    The magnetic, magnetocaloric and thermal characteristics have been studied in a Ni(50.3)Mn(20.8)Ga(27.6)V(1.3) ferromagnetic shape memory alloy (FSMA) transforming martensitically at around 40 K. The alloy shows first a transformation from austenite to an intermediate phase and then a partial transformation to an orthorhombic martensite, all the phases being ferromagnetically ordered. The thermomagnetization dependences enabled observation of the magnetocaloric effect in the vicinity of the martensitic transformation (MT). The Debye temperature and the density of states at the Fermi level are equal to θ(D) = (276 ± 4) K and 1.3 states/atom eV , respectively, and scarcely dependent on the magnetic field. The MT exhibited by Ni-Mn-Ga FSMAs at very low temperatures is distinctive in the sense that it is accompanied by a hardly detectable entropy change as a sign of a small driving force. The enhanced stability of the cubic phase and the low driving force of the MT stem from the reduced density of states near the Fermi level.

  18. Temperature dependence of magnetically induced deformation of Ni-Mn-Ga martensite

    Science.gov (United States)

    L'Vov, V. A.; Glavatska, N.; Aaltio, I.; Söderberg, O.; Glavatskiy, I.; Hannula, S.-P.

    2008-05-01

    In the present work the contributions of the temperature-dependent (i) crystal lattice parameters (related to the magnetic anisotropy energy), (ii) Young's modulus, (iii) saturation magnetization and (iv) thermal fluctuations of the microstress to the temperature dependence of the magnetic field induced strain (MFIS) in Ni-Mn-Ga martensite are considered in the framework of a statistical model. Both individual and cooperative effects of these factors on the achievable MFIS value and on the characteristic values of the magnetic fields, which trigger and saturate MFIS, are estimated. It is shown that all the factors affect both the achievable MFIS value and characteristic fields under the real experimental conditions, and none of them can be neglected in the quantitative theoretical analysis of the experimental strain-field dependencies obtained for different temperature values. In addition, the influence of specimen shape on the characteristic fields is illustrated for different temperature values. For the available experimental dependencies (i) (iii) and the reasonable set of model parameters the switching magnetic field proved to be equal to 160 kA/m when the temperature was by 15 K below the martensite start temperature and raised to 320 kA/m when the temperature was by 45 K below the martensite start temperature. Obtained results agree with the experimental data reported by O. Heczko and L. Straka, in J. Appl. Phys. 94, 7139 (2003).

  19. The effect of magnetic stress and stiffness modulus on resonant characteristics of Ni-Mn-Ga ferromagnetic shape memory alloy actuators

    Energy Technology Data Exchange (ETDEWEB)

    Techapiesancharoenkij, Ratchatee, E-mail: fengrct@ku.ac.th [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Kostamo, Jari; Allen, Samuel M.; O' Handley, Robert C. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2011-12-15

    The prospect of using ferromagnetic shape memory alloys (FSMAs) is promising for a resonant actuator that requires large strain output and a drive frequency below 1 kHz. In this investigation, three FSMA actuators, equipped with tetragonal off-stoichiometric Ni{sub 2}MnGa single crystals, were developed to study their frequency response and resonant characteristics. The first actuator, labeled as A1, was constructed with low-k bias springs and one Ni-Mn-Ga single crystal. The second actuator, labeled as A2, was constructed with high-k bias springs and one Ni-Mn-Ga crystal. The third actuator, labeled as A3, was constructed with high-k bias springs and two Ni-Mn-Ga crystals connected in parallel. The three actuators were magnetically driven over the frequency range of 10 Hz-1 kHz under 2 and 3.5 kOe magnetic-field amplitudes. The field amplitude of 2 kOe is insufficient to generate significant strain output from all three actuators; the maximum magnetic-field-induced strain (MFIS) at resonance is 2%. The resonant MFIS output improves to 5% under 3.5-kOe amplitude. The frequency responses of all three actuators show a strong effect of the spring k constant and the Ni-Mn-Ga modulus stiffness on the resonant frequencies. The resonant frequency of the Ni-Mn-Ga actuator was raised from 450 to 650 Hz by increasing bias spring k constant and/or the number of Ni-Mn-Ga crystals. The higher number of the Ni-Mn-Ga crystals not only increases the magnetic force output but also raises the total stiffness of the actuator resulting in a higher resonant frequency. The effective modulus of the Ni-Mn-Ga is calculated from the measured resonant frequencies using the mass-spring equation; the calculated modulus values for the three actuators fall in the range of 50-60 MPa. The calculated effective modulus appears to be close to the average modulus value between the low twinning modulus and high elastic modulus of the untwined Ni-Mn-Ga crystal. - Highlights: > Dynamic FSMA actuation

  20. Effect of Dy addition on mechanical and magnetic properties of Mn-rich Ni-Mn-Ga ferromagnetic shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gao, L., E-mail: lgao@shou.edu.cn [College of Engineering Science and Technology, Shanghai Ocean University, Shanghai 201306 (China); Dong, G.F. [Department of Physics, Dalian University, Dalian 116622 (China); Gao, Z.Y.; Cai, W. [School of Materials Science and Engineering, P.O. Box 405, Harbin Institute of Technology, Harbin, 150001 (China)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer The Dy addition significantly improves the compressive properties of Ni-Mn-Ga alloy. Black-Right-Pointing-Pointer The mechanism of the improved mechanical properties by adding Dy is discussed. Black-Right-Pointing-Pointer Dy doping results in a change of the fracture type of Ni-Mn-Ga alloy. Black-Right-Pointing-Pointer Curie temperature almost remained unchanged at low Dy content and then decreases. - Abstract: The effects of partial substitution of rare earth Dy for Ga on the mechanical and magnetic properties of Mn-rich Ni{sub 50}Mn{sub 29}Ga{sub 21-x}Dy{sub x} (0 {<=} x {<=} 5) ferromagnetic shape memory alloys were investigated in detail. The results show that an appropriate amount of Dy addition significantly improves the mechanical properties of Ni-Mn-Ga alloy. With an increase in Dy content, the compressive strength enhances rapidly at first and then becomes stable when the Dy content is more than 1 at.%. However, the compressive strain increases dramatically and reaches a maximum value with 1 at.% Dy addition. Further increase in Dy content makes the compressive strain of the alloys decrease gradually. The mechanism of the improved mechanical properties is also discussed. Moreover, Dy doping changes the fracture type from intergranular fracture of Ni-Mn-Ga alloy to transgranular cleavage fracture of Ni-Mn-Ga-Dy alloys. The Curie temperature remains almost unchanged at low Dy content and subsequently decreases.

  1. Effect of Trivalent Additions and Processing on Structural and Magnetic Transitions in Ni-Mn-Ga Ferromagnetic Shape Memory Alloys

    OpenAIRE

    R. P. Mathur; Singh, R. K.; Ray, S.; P. Ghosal; Chandrasekaran, V.

    2012-01-01

    Ferromagnetic shape memory Ni50Mn30Ga15Al5-xBx (x = 0, 1, and 4) alloys were prepared by vacuum arc melting and subsequent heat-treatment as well as by melt spinning to investigate the effect of trivalent element additions in ternary Ni-Mn-Ga alloys. The heat-treated alloys containing Al were reported to possess a modulated martensite structure, however alloy containing both Al and B showed a loss of modulated structure in martensite formed. The rapidly solidified alloys on the other hand sho...

  2. Stress-induced martensite variant reorientation in magnetic shape memory Ni Mn Ga single crystal studied by neutron diffraction

    Science.gov (United States)

    Molnar, P.; Sittner, P.; Lukas, P.; Hannula, S.-P.; Heczko, O.

    2008-06-01

    Stress-induced martensite variant reorientation in magnetic shape memory Ni-Mn-Ga single crystal was studied in situ by the neutron diffraction technique. Principles of determination of individual tetragonal martensitic variants in shape memory alloys are explained. Using neutron diffraction we show that the macroscopic strain originates solely from the martensite structure reorientation or variant redistribution. Neutron diffraction also reveals that the reorientation of martensite is not fully completed even at a stress value of 25 MPa, which is about 20 times larger than the mean stress needed for reorientation. Only one twinning system is active during the reorientation process.

  3. Inertia-Controlled Twinning in Ni-Mn-Ga Actuators: A Discrete Twin-Boundary Dynamics Study

    Science.gov (United States)

    Faran, Eilon; Riccardi, Leonardo; Shilo, Doron

    2017-07-01

    A discrete twin-boundary modeling approach is applied for simulating the dynamic magnetomechanical response of a Ni-Mn-Ga actuator over a wide frequency range. The model is based on experimentally measured kinetic relation of individual twin boundaries and takes into account inertial forces due to acceleration of the actuator's mass. The calculated results show good agreement with experimental measurements performed on a specially designed Ni-Mn-Ga linear spring-mass actuator. In addition, the simulation reveals several new effects that have not been considered before and can be applied to the design of improved actuators. It is identified that the demagnetization effect plays a role of an "effective spring" and results in a resonance-type response. The effects of the actuator's mass and the twin-boundary density on the resonance response and the actuator performance are explored numerically. In particular, it is shown that mass-inertia poses an inherent upper limit over the actuator's bandwidth, which is approximately constant and equals to about 200 Hz.

  4. Stress analysis, structure and magnetic properties of sputter deposited Ni-Mn-Ga ferromagnetic shape memory thin films

    Science.gov (United States)

    Annadurai, A.; Manivel Raja, M.; Prabahar, K.; Kumar, Atul; Kannan, M. D.; Jayakumar, S.

    2011-11-01

    The residual stress instituted in Ni-Mn-Ga thin films during deposition is a key parameter influencing their shape memory applications by affecting its structural and magnetic properties. A series of Ni-Mn-Ga thin films were prepared by dc magnetron sputtering on Si(1 0 0) and glass substrates at four different sputtering powers of 25, 45, 75 and 100 W for systematic investigation of the residual stress and its effect on structure and magnetic properties. The residual stresses in thin films were characterized by a laser scanning technique. The as-deposited films were annealed at 600 °C for 1 h in vacuum for structural and magnetic ordering. The compressive stresses observed in as-deposited films transformed into tensile stresses upon annealing. The annealed films were found to be crystalline and possess mixed phases of both austenite and martensite, exhibiting good soft magnetic properties. It was found that the increase of sputtering power induced coarsening in thin films. Typical saturation magnetization and coercivity values were found to be 330 emu/cm 3 and 215 Oe, respectively. The films deposited at 75 and 100 W display both structural and magnetic transitions above room temperature.

  5. High-cycle fatigue of 10M Ni-Mn-Ga magnetic shape memory alloy in reversed mechanical loading

    Science.gov (United States)

    Aaltio, I.; Soroka, A.; Ge, Y.; Söderberg, O.; Hannula, S.-P.

    2010-07-01

    Application of Ni-Mn-Ga magnetic shape memory alloys in magnetic-field-induced actuation relies on their performance in long-term high-cycle fatigue. In this paper the performance and changes in the microstructure of a Ni-Mn-Ga 10M martensite single crystal material are reported in a long-term mechanically induced shape change cycling. The longest test was run for 2 × 109 cycles at a frequency of 250 Hz and a strain amplitude of ± 1%. After the test a clear increase of the dynamic stiffness of the material was detected. Three specimens out of ten were cycled until fracture occurred and their fracture mechanism was studied. It was observed that the macroscopic crack growth took place roughly at a 45° angle with respect to the loading direction that was along the lang100rang crystallographic direction of the sample. The macroscopic fracture plane seemed to correspond roughly to the {111} crystal planes. On a microscopic scale the fracture propagated in a step-like manner at least partly along crystallographic planes. The steps at the fracture plane correspond to the {101} twin planes, with the height of steps along the lang101rang direction. The final fracture of the samples occurred in a brittle manner after the critical stress was exceeded.

  6. Enhanced magnetic hysteresis in Ni-Mn-Ga single crystal and its influence on magnetic shape memory effect

    Energy Technology Data Exchange (ETDEWEB)

    Heczko, O., E-mail: heczko@fzu.cz; Drahokoupil, J. [Institute of Physics, ASCR, Na Slovance 2, 182 21 Prague (Czech Republic); Straka, L. [Laboratory of Engineering Materials, Aalto University School of Engineering, PL 14200, FIN-00076 Aalto (Finland)

    2015-05-07

    Enhanced magnetic hysteresis due to boron doping in combination with magnetic shape memory effect in Ni-Mn-Ga single crystal results in new interesting functionality of magnetic shape memory (MSM) alloys such as mechanical demagnetization. In Ni{sub 50.0}Mn{sub 28.5}Ga{sub 21.5} single crystal, the boron doping increased magnetic coercivity from few Oe to 270 Oe while not affecting the transformation behavior and 10 M martensite structure. However, the magnetic field needed for MSM effect also increased in doped sample. The magnetic behavior is compared to undoped single crystal of similar composition. The evidence from the X-ray diffraction, magnetic domain structure, magnetization loops, and temperature evolution of the magnetic coercivity points out that the enhanced hysteresis is caused by stress-induced anisotropy.

  7. Direct evidence for stress-induced transformation between coexisting multiple martensites in a Ni-Mn-Ga multifunctional alloy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, L.; Cong, D. Y.; Wang, Z. L.; Nie, Z. H.; Dong, Y. H.; Zhang, Y.; Ren, Yang; Wang, Y. D.

    2015-07-08

    The structural response of coexisting multiple martensites to stress field in a Ni-Mn-Ga multifunctional alloy was investigated by the in situ high-energy x-ray diffraction technique. Stress-induced transformation between coexisting multiple martensites was observed at 110 K, at which five-layered modulated (5M), seven-layered modulated (7M) and non-modulated (NM) martensites coexist. We found that a tiny stress of as low as 0.5 MPa could trigger the transformation from 5M and 7M martensites to NM martensite and this transformation is partly reversible. Besides the transformation between coexisting multiple martensites, rearrangement of martensite variants also occurs during loading, at least at high stress levels. The present study is instructive for designing advanced multifunctional alloys with easy actuation.

  8. Direct evidence for stress-induced transformation between coexisting multiple martensites in a Ni-Mn-Ga multifunctional alloy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, L.; Cong, D. Y.; Wang, Z. L.; Nie, Z. H.; Dong, Y. H.; Zhang, Y.; Ren, Yang; Wang, Y. D.

    2015-06-03

    The structural response of coexisting multiple martensites to stress field in a Ni-Mn-Ga multifunctional alloy was investigated by the in situ high-energy x-ray diffraction technique. Stress-induced transformation between coexisting multiple martensites was observed at 110 K, at which five-layered modulated (5M), seven-layered modulated (7M) and non-modulated (NM) martensites coexist. We found that a tiny stress of as low as 0.5 MPa could trigger the transformation from 5M and 7M martensites to NM martensite and this transformation is partly reversible. Besides the transformation between coexisting multiple martensites, rearrangement of martensite variants also occurs during loading, at least at high stress levels. The present study is instructive for designing advanced multifunctional alloys with easy actuation.

  9. Electronic structure and magneto-optical Kerr effect spectra of ferromagnetic shape-memory Ni-Mn-Ga alloys: Experiment and density functional theory calculations

    Science.gov (United States)

    Uba, S.; Bonda, A.; Uba, L.; Bekenov, L. V.; Antonov, V. N.; Ernst, A.

    2016-08-01

    In this joint experimental and ab initio study, we focused on the influence of the chemical composition and martensite phase transition on the electronic, magnetic, optical, and magneto-optical properties of the ferromagnetic shape-memory Ni-Mn-Ga alloys. The polar magneto-optical Kerr effect (MOKE) spectra for the polycrystalline sample of the Ni-Mn-Ga alloy of Ni60Mn13Ga27 composition were measured by means of the polarization modulation method over the photon energy range 0.8 ≤h ν ≤5.8 eV in magnetic field up to 1.5 T. The optical properties (refractive index n and extinction coefficient k ) were measured directly by spectroscopic ellipsometry using the rotating analyzer method. To complement experiments, extensive first-principles calculations were made with two different first-principles approaches combining the advantages of a multiple scattering Green function method and a spin-polarized fully relativistic linear-muffin-tin-orbital method. The electronic, magnetic, and MO properties of Ni-Mn-Ga Heusler alloys were investigated for the cubic austenitic and modulated 7M-like incommensurate martensitic phases in the stoichiometric and off-stoichiometric compositions. The optical and MOKE properties of Ni-Mn-Ga systems are very sensitive to the deviation from the stoichiometry. It was shown that the ab initio calculations reproduce well experimental spectra and allow us to explain the microscopic origin of the Ni2MnGa optical and magneto-optical response in terms of interband transitions. The band-by-band decomposition of the Ni2MnGa MOKE spectra is presented and the interband transitions responsible for the prominent structures in the spectra are identified.

  10. Effect of Fe substitution on the phase stability and magnetic properties of Mn-rich Ni-Mn-Ga ferromagnetic shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Singh, R.K., E-mail: rksingh1978@yahoo.co.i [Defence Metallurgical Research Laboratory, Hyderabad 500 058 (India); Manivel Raja, M.; Mathur, R.P. [Defence Metallurgical Research Laboratory, Hyderabad 500 058 (India); Shamsuddin, M. [Department of Metallurgical Engineering, Institute of Technology, Banaras Hindu University, Varanasi 221 005 (India)

    2011-03-15

    The influence of Fe additions on the martensitic transformation and magnetic properties of Mn-rich Ni-Mn-Ga alloys was investigated by substituting either 1 at% Fe for each atomic species or by substituting Ni with varying amounts of Fe. The magnetic structure of the alloys was studied using {sup 57}Fe Moessbauer spectroscopy. Moessbauer spectra revealed typical paramagnetic features in Mn-rich Ni-Mn-Ga-Fe alloys owing to the preferential site occupancy of Fe atoms at Ni sites. The evolution of the magnetic properties and phase stability has been correlated with the chemical and atomic ordering in these alloys. - Research highlights: Fe atoms preferentially occupy Ni sites over vacant Ga sites in Mn-rich Ni-Mn-Ga alloys. Such chemical order suppresses the magnetic hyperfine field of Fe atoms due to the interaction with the surrounding Ga and Mn atoms. Accordingly, the Curie temperature and saturation magnetization decrease. This short range ordering also influences the phase stability.

  11. Co and In Doped Ni-Mn-Ga Magnetic Shape Memory Alloys: A Thorough Structural, Magnetic and Magnetocaloric Study

    Directory of Open Access Journals (Sweden)

    Simone Fabbrici

    2014-04-01

    Full Text Available In Ni-Mn-Ga ferromagnetic shape memory alloys, Co-doping plays a major role in determining a peculiar phase diagram where, besides a change in the critical temperatures, a change of number, order and nature of phase transitions (e.g., from ferromagnetic to paramagnetic or from paramagnetic to ferromagnetic, on heating can be obtained, together with a change in the giant magnetocaloric effect from direct to inverse. Here we present a thorough study of the intrinsic magnetic and structural properties, including their dependence on hydrostatic pressure, that are at the basis of the multifunctional behavior of Co and In-doped alloys. We study in depth their magnetocaloric properties, taking advantage of complementary calorimetric and magnetic techniques, and show that if a proper measurement protocol is adopted they all merge to the same values, even in case of first order transitions. A simplified model for the estimation of the adiabatic temperature change that relies only on indirect measurements is proposed, allowing for the quick and reliable evaluation of the magnetocaloric potentiality of new materials starting from readily available magnetic measurements.

  12. Training, constraints, and high-cycle magneto-mechanical properties of Ni-Mn-Ga magnetic shape-memory alloys

    Science.gov (United States)

    Chmielus, M.; Chernenko, V. A.; Knowlton, W. B.; Kostorz, G.; Müllner, P.

    2008-05-01

    Magneto-mechanical experiments with a rotating magnetic field of 0.97 T were performed with a Ni-Mn-Ga single crystal. Periodic strains exceeding 1% were recorded over a hundred million magneto-mechanical cycles. The twin microstructure of the cycled crystal was characterized using atomic force microscopy (AFM) and magnetic force microscopy (MFM). In the center of the sample, no twin boundaries were found. At the sample edges, the microstructure shows a dense twin pattern. The results are compared with previous experiments of differently trained crystals. It is useful to distinguish between “ineffective training”, which results in a nearly self-accommodated martensite, and “effective training”, which results in a nearly single-variant crystal. The evolution of twin structure is discussed in terms of training, magneto-mechanical cycling, and extrinsic constraints imposed by the experimental setting. It is concluded that the response of a magnetic shape memory alloy to an alternating excitation depends strongly on the initial twin microstructure established through training. In particular, ineffective training results in a twin microstructure which can adapt to extrinsic constraints resulting in continued large periodic magnetic-field-induced deformation. In contrast, the twin microstructure of an effectively trained crystal can not adapt to extrinsic constraints resulting in early failure by fracture.

  13. Determination of the orientation relationship between austenite and incommensurate 7M modulated martensite in Ni-Mn-Ga alloys

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z.B. [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China); Zhang, Y.D. [Laboratoire d' Etude des Microstructures et de Mecanique des Materiaux (LEM3), CNRS UMR 7239, Universite Paul Verlaine - Metz, 57045 Metz (France); Esling, C., E-mail: claude.esling@univ-metz.fr [Laboratoire d' Etude des Microstructures et de Mecanique des Materiaux (LEM3), CNRS UMR 7239, Universite Paul Verlaine - Metz, 57045 Metz (France); Zhao, X. [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China); Zuo, L., E-mail: lzuo@mail.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China)

    2011-04-15

    For Ni-Mn-Ga ferromagnetic shape memory alloys, a large magnetic-field-induced strain could be reached through the reorientation of martensitic variants in the martensite state. Owing to the collective and displacive nature of the austenite to martensite transformation, a certain orientation relationship (OR) between the parent and the product phase is required to minimize the transformation strain and the strain energy generated, which brings about self-accommodating groups of martensitic variants with specific orientation correlations. In this work, the microstructural and crystallographic characteristics of martensitic variants in a polycrystalline Ni{sub 50}Mn{sub 30}Ga{sub 20} alloy were investigated by electron backscatter diffraction analysis. With accurate orientation measurement on inherited martensitic variants, the local orientations of parent austenite grains were predicted using four classical OR for the martensitic transformation. Furthermore, a specific OR, namely the Pitsch relation with (1 0 1){sub A}//(1 2-bar 10-bar){sub 7M} and [1 0 1-bar]{sub A}//[10-bar 10-bar 1]{sub 7M}, was unambiguously determined by considering the magnitude of discontinuity between the lattices of the product and parent phases and the structural modulation of the incommensurate 7M modulated martensite. The present procedure to determine the OR, without recourse to the presence of retained austenite, is in general applicable to a variety of materials with modulated superstructure for insight into their martensitic transformation processes.

  14. Optical and magneto-optical studies of martensitic transformation in Ni-Mn-Ga magnetic shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Beran, L.; Cejpek, P.; Kulda, M.; Antos, R.; Holy, V.; Veis, M., E-mail: veis@karlov.mff.cuni.cz [Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 12116 Prague (Czech Republic); Straka, L. [Laboratory of Engineering Materials, Aalto University, PL 14200, FIN-00076 Aalto (Finland); Heczko, O. [Institute of Physics ASCR, Na Slovance 2, 18221 Prague (Czech Republic)

    2015-05-07

    Optical and magneto-optical properties of single crystal of Ni{sub 50.1}Mn{sub 28.4}Ga{sub 21.5} magnetic shape memory alloy during its transformation from martensite to austenite phase were systematically studied. Crystal orientation was approximately along (100) planes of parent cubic austenite. X-ray reciprocal mapping confirmed modulated 10 M martensite phase. Temperature depended measurements of saturation magnetization revealed the martensitic transformation at 335 K during heating. Magneto-optical spectroscopy and spectroscopic ellipsometry were measured in the sample temperature range from 297 to 373 K and photon energy range from 1.2 to 6.5 eV. Magneto-optical spectra of polar Kerr rotation as well as the spectra of ellipsometric parameter Ψ exhibited significant changes when crossing the transformation temperature. These changes were assigned to different optical properties of Ni-Mn-Ga in martensite and austenite phases due to modification of electronic structure near the Fermi energy during martensitic transformation.

  15. The effect of antiphase boundaries on the elastic properties of Ni-Mn-Ga austenite and premartensite.

    Science.gov (United States)

    Seiner, Hanuš; Sedlák, Petr; Bodnárová, Lucie; Drahokoupil, Jan; Kopecký, Vít; Kopeček, Jaromír; Landa, Michal; Heczko, Oleg

    2013-10-23

    The evolution of elastic properties with temperature and magnetic field was studied in two differently heat-treated single crystals of the Ni-Mn-Ga magnetic shape memory alloy using resonant ultrasound spectroscopy. Quenching and slow furnace cooling were used to obtain different densities of antiphase boundaries. We found that the crystals exhibited pronounced differences in the c' elastic coefficient and related shear damping in high-temperature ferromagnetic phases (austenite and premartensite). The difference can be ascribed to the formation of fine magnetic domain patterns and pinning of the magnetic domain walls on antiphase boundaries in the material with a high density of antiphase boundaries due to quenching. The fine domain pattern arising from mutual interactions between antiphase boundaries and ferromagnetic domain walls effectively reduces the magnetocrystalline anisotropy and amplifies the contribution of magnetostriction to the elastic response of the material. As a result, the anomalous elastic softening prior to martensite transformation is significantly enhanced in the quenched sample. Thus, for any comparison of experimental data and theoretical calculations the microstructural changes induced by specific heat treatment must be taken into account.

  16. Effect of Trivalent Additions and Processing on Structural and Magnetic Transitions in Ni-Mn-Ga Ferromagnetic Shape Memory Alloys

    Directory of Open Access Journals (Sweden)

    R. P. Mathur

    2012-07-01

    Full Text Available Ferromagnetic shape memory Ni50Mn30Ga15Al5-xBx (x = 0, 1, and 4 alloys were prepared by vacuum arc melting and subsequent heat-treatment as well as by melt spinning to investigate the effect of trivalent element additions in ternary Ni-Mn-Ga alloys. The heat-treated alloys containing Al were reported to possess a modulated martensite structure, however alloy containing both Al and B showed a loss of modulated structure in martensite formed. The rapidly solidified alloys on the other hand showed the formation of a similar modulated structure without composition change in alloys containing Al and the alloys containing Al and B. In addition, the former showed a presence of an amorphous phase with latter showing crystalline boron rich phases. The magnetisation of the B containing alloys in both the processing technique was however very low, showing lower magnetic exchange interaction in such alloys.Defence Science Journal, 2012, 62(4, pp.252-260, DOI:http://dx.doi.org/10.14429/dsj.62.1279

  17. Probing structure and microstructure of epitaxial Ni-Mn-Ga films by reciprocal space mapping and pole figure measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Y., E-mail: yanling.ge@tkk.fi [Aalto University, School of Science and Technology, Department of Materials Science and Engineering, PO Box 16200, FI-00076 Aalto (Finland); Heczko, O. [Institute of Physics, AS CR, Na Slovance 2, CZ-18221 Praha 8 (Czech Republic); Hannula, S.-P. [Aalto University, School of Science and Technology, Department of Materials Science and Engineering, PO Box 16200, FI-00076 Aalto (Finland); Faehler, S. [IFW Dresden, PO Box 270116, 01171 Dresden (Germany)

    2010-12-15

    The crystal structure and complex twinning microstructure of epitaxial Ni-Mn-Ga films on (1 0 0) MgO substrates was studied by X-ray diffraction using 2{theta} scans, pole figure measurements and reciprocal space mapping (RSM). The orientation distribution of all variants is visualized by RSM, which forms the basis for a better understanding of the crystallographic relation between variants and substrate. Above the martensitic transformation temperature the film consists of single austenite phase with lattice constant a = 5.81 A at 419 K. At room temperature some epitaxially grown residual austenite with a = 5.79 A remains at the interface with the substrate, followed by an intermediate layer exhibiting orthorhombic distortion, a{sub trans} = 6.05 A, b{sub trans} = 5.87 A, c{sub trans} = 5.73 A and a major fraction of 14M (7M) martensite, a = 6.16 Ab = 5.79 Ac = 5.48 A. The seven-layered modulation of this metastable martensite structure is directly observed by RSM. The intermediate phase observed close to interface indicates the existence of an instable, pre-adaptive martensite phase with a short stacking period.

  18. Ab Initio and Monte Carlo Approaches For the Magnetocaloric Effect in Co- and In-Doped Ni-Mn-Ga Heusler Alloys

    Directory of Open Access Journals (Sweden)

    Vladimir Sokolovskiy

    2014-09-01

    Full Text Available The complex magnetic and structural properties of Co-doped Ni-Mn-Ga Heusler alloys have been investigated by using a combination of first-principles calculations and classical Monte Carlo simulations. We have restricted the investigations to systems with 0, 5 and 9 at% Co. Ab initio calculations show the presence of the ferrimagnetic order of austenite and martensite depending on the composition, where the excess Mn atoms on Ga sites show reversed spin configurations. Stable ferrimagnetic martensite is found for systems with 0 (5 at% Co and a c=a ratio of 1.31 (1.28, respectively, leading to a strong competition of ferro- and antiferro-magnetic exchange interactions between nearest neighbor Mn atoms. The Monte Carlo simulations with ab initio exchange coupling constants as input parameters allow one to discuss the behavior at finite temperatures and to determine magnetic transition temperatures. The Curie temperature of austenite is found to increase with Co, while the Curie temperature of martensite decreases with increasing Co content. This behavior can be attributed to the stronger Co-Mn, Mn-Mn and Mn-Ni exchange coupling constants in austenite compared to the corresponding ones in martensite. The crossover from a direct to inverse magnetocaloric effect in Ni-Mn-Ga due to the substitution of Ni by Co leads to the appearance of a “paramagnetic gap” in the martensitic phase. Doping with In increases the magnetic jump at the martensitic transition temperature. The simulated magnetic and magnetocaloric properties of Co- and In-doped Ni-Mn-Ga alloys are in good qualitative agreement with the available experimental data.

  19. Magnetoelectric coupling in multiferroic heterostructure of rf-sputtered Ni-Mn-Ga thin film on PMN-PT

    Energy Technology Data Exchange (ETDEWEB)

    Teferi, M.Y., E-mail: mandefero2002@yahoo.com [Departamento de Fisica, Universidade de Aveiro, 3810-193 Aveiro (Portugal); CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Amaral, V.S.; Lounrenco, A.C.; Das, S. [Departamento de Fisica, Universidade de Aveiro, 3810-193 Aveiro (Portugal); CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Amaral, J.S. [Departamento de Fisica, Universidade de Aveiro, 3810-193 Aveiro (Portugal); CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); IFIMUP-IN and Departamento de Fisica e Astronomia da Faculdade de Ciencias da Universidade do Porto, 4169-007 Porto (Portugal); Karpinsky, D.V. [CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Departamento de Engenharia Ceramica e do Vidro, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Soares, N. [Departamento de Fisica, Universidade de Aveiro, 3810-193 Aveiro (Portugal); CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Sobolev, N.A. [Departamento de Fisica, Universidade de Aveiro, 3810-193 Aveiro (Portugal); I3N, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Kholkin, A.L. [CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Departamento de Engenharia Ceramica e do Vidro, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Tavares, P.B. [Centro de Quimica, Universidade de Tras-os-Montes e Alto Douro, 5001-801 Vila Real (Portugal)

    2012-06-15

    In this paper, we report a preparation of multiferroic heterostructure from thin film of Ni-Mn-Ga (NMG) alloy and lead magnesium niobate-lead titanate (PMN-PT) with effective magnetoelectric (ME) coupling between the film as ferromagnetic material and PMN-PT as piezoelectric material. The heterostructure was prepared by relatively low temperature (400 Degree-Sign C) deposition of the film on single crystal of piezoelectric PMN-PT substrate using rf magnetron co-sputtering of Ni{sub 50}Mn{sub 50} and Ni{sub 50}Ga{sub 50} targets. Magnetic measurements by Superconducting Quantum Interference Design (SQIUD) Magnetometer and Vibrating Sample Magnetometer (VSM) on the film revealed that the film is in ferromagnetically ordered martensitic state at room temperature with saturation magnetization of {approx}240 emu/cm{sup 3} and Curie temperature of {approx}337 K. Piezoresponse force microscopy (PFM) measurement done at room temperature on the substrate showed the presence of expected hysteresis loop confirming the stability of the piezoelectric state of the substrate after deposition. Room temperature ME voltage coefficient ({alpha}{sub ME}) of the heterostructure was measured as a function of applied bias dc magnetic field in Longitudinal-Transverse (L-T) ME coupling mode by lock-in technique. A maximum ME coefficient {alpha}{sub ME} of 3.02 mV/cm Oe was measured for multiferroic NMG/PMN-PT heterostructure which demonstrates that there is ME coupling between the film as ferromagnetic material and PMN-PT as piezoelectric material. - Highlights: Black-Right-Pointing-Pointer Multiferroic NMG/PMN-PT heterostructure prepared by depositing NMG alloy thin film on PMN-PT substrate. Black-Right-Pointing-Pointer The film is in ferromagnetically ordered martensite state at room temperature. Black-Right-Pointing-Pointer The substrate maintains its piezoelectric state after deposition. Black-Right-Pointing-Pointer The heterostructure exhibits ME effect with maximum of {alpha}{sub ME

  20. Field-temperature phase diagrams of freestanding and substrate-constrained epitaxial Ni-Mn-Ga-Co films for magnetocaloric applications

    Science.gov (United States)

    Diestel, A.; Niemann, R.; Schleicher, B.; Schwabe, S.; Schultz, L.; Fähler, S.

    2015-07-01

    Ferroic cooling processes that rely on field-induced first-order transformations of solid materials are a promising step towards a more energy-efficient refrigeration technology. In particular, thin films are discussed for their fast heat transfer and possible applications in microsystems. Substrate-constrained films are not useful since their substrates act as a heat sink. In this article, we examine a substrate-constrained and a freestanding epitaxial film of magnetocaloric Ni-Mn-Ga-Co. We compare phase diagrams and entropy changes obtained by magnetic field and temperature scans, which differ. We observe an asymmetry of the hysteresis between heating and cooling branch, which vanishes at high magnetic fields. These effects are discussed with respect to the vector character of a magnetic field, which acts differently on the nucleation and growth processes compared to the scalar character of the temperature.

  1. Latent heat contribution to the direct magnetocaloric effect in Ni-Mn-Ga shape memory alloys with coupled martensitic and magnetic transformations

    Science.gov (United States)

    Caballero-Flores, R.; Sánchez-Alarcos, V.; Recarte, V.; Pérez-Landazábal, J. I.; Gómez-Polo, C.

    2016-05-01

    We report the direct magnetocaloric response of materials that present a second-order phase transition in the temperature range where a first-order structural transition also occurs. In particular, the influence of the latent heat on the field-induced adiabatic temperature change has been analyzed in a Ni-Mn-Ga alloy with coupled martensitic and magnetic transformations. It is found that discrepancies around 20% arise depending on whether the latent heat is taken into account or not. From the observed results, a general expression for the indirect determination of the adiabatic temperature change, that takes into account the contributions of both the martensitic and magnetic transformations, is proposed and experimentally confirmed. The observed key role of the latent heat allows us to understand why materials with first-order transformations do not present adiabatic temperature changes as higher as those which would correspond to materials undergoing second-order transformations with similar isothermal entropy change.

  2. Changes in magnetic domain structure during twin boundary motion in single crystal Ni-Mn-Ga exhibiting magnetic shape memory effect

    Science.gov (United States)

    Kopecký, V.; Fekete, L.; Perevertov, O.; Heczko, O.

    2016-05-01

    The complexity of Ni-Mn-Ga single crystal originates from the interplay between ferromagnetic domain structure and ferroelastic twinned microstructure. Magnetic domain structure in the vicinity of single twin boundary was studied using magneto-optical indicator film and magnetic force microscopy technique. The single twin boundary of Type I was formed mechanically and an initial magnetization state in both variants were restored by local application of magnetic field (≈40 kA/m). The differently oriented variants exhibited either stripe or labyrinth magnetic domain pattern in agreement with the uniaxial magnetocrystalline anisotropy of the martensite. The twin boundary was then moved by compressive or tensile stress. The passage of the boundary resulted in the formation of granular or rake domains, respectively. Additionally, the specific magnetic domains pattern projected by twin boundary gradually vanished during twin boundary motion.

  3. Changes in magnetic domain structure during twin boundary motion in single crystal Ni-Mn-Ga exhibiting magnetic shape memory effect

    Directory of Open Access Journals (Sweden)

    V. Kopecký

    2016-05-01

    Full Text Available The complexity of Ni-Mn-Ga single crystal originates from the interplay between ferromagnetic domain structure and ferroelastic twinned microstructure. Magnetic domain structure in the vicinity of single twin boundary was studied using magneto-optical indicator film and magnetic force microscopy technique. The single twin boundary of Type I was formed mechanically and an initial magnetization state in both variants were restored by local application of magnetic field (≈40 kA/m. The differently oriented variants exhibited either stripe or labyrinth magnetic domain pattern in agreement with the uniaxial magnetocrystalline anisotropy of the martensite. The twin boundary was then moved by compressive or tensile stress. The passage of the boundary resulted in the formation of granular or rake domains, respectively. Additionally, the specific magnetic domains pattern projected by twin boundary gradually vanished during twin boundary motion.

  4. Fine-grained concrete with organomineral additive

    Directory of Open Access Journals (Sweden)

    Solovyov Vitaly

    2016-01-01

    Full Text Available The article deals with the issues concerning the formation of the structure and properties of fine-grained concrete with organomineral additive produced through mechanochemical activation of thermal power plant fly ash together with superplasticizer. The additive is produced in a high-speed activator at the collision particles’ speed of about 80 m/s. The use of the additive in fine-grained concrete in the amounts of 0.5-1% increased the strength by 30-50% and reduced the size and volume of pores. The cement consumption in such concrete is close to the cement consumption in common concrete of equal resistance.

  5. ELECTROSTATICALLY SUPPORTED MIXING OF FINE GRAINED PARTICLES

    Institute of Scientific and Technical Information of China (English)

    K.-E.; Wirth; M.; Linsenbühler

    2005-01-01

    The processing of fine-grained particles with diameters between 1 and 10 microns is difficult due to strong van-der-Waals attraction forces. In order to improve the handling properties, the fine-grained particles, i.e. host-particles,are coated with various nanoparticles, i.e. guest-particles. The mixing of fine-grained powders is influenced by particle-particle interactions. If these forces are distinctively used, both interactive and ordered mixtures can be produced.These particle mixtures consist of composite-particles that have new physical properties. These modified properties d epend strongly on the coating process, the diameter- and mass-relationship of the guest- and the host-particles. The properties of the composite-particles can systematically be adjusted to the requirements of industrial applications. For example, a laboratory bubbling fluidized bed can be used to describe the conveying behavior of the functionalized host-particles. Applications for the functionalized particles are in the pharmaceutical and the powder coating industries,e.g. enhanced dry powder inhalers and thin lacquer films. The present research compares three different mixing/coating processes. The composite-particles are characterized by TEM, SEM and with their fluidization characteristics. The coating process itself is monitored by the electrostatic charge of the particles.

  6. Communication Optimizations for Fine-Grained UPCApplications

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Yu; Iancu, Costin; Yelick, Katherine

    2005-07-08

    Global address space languages like UPC exhibit high performance and portability on a broad class of shared and distributed memory parallel architectures. The most scalable applications use bulk memory copies rather than individual reads and writes to the shared space, but finer-grained sharing can be useful for scenarios such as dynamic load balancing, event signaling, and distributed hash tables. In this paper we present three optimization techniques for global address space programs with fine-grained communication: redundancy elimination, use of split-phase communication, and communication coalescing. Parallel UPC programs are analyzed using static single assignment form and a data flow graph, which are extended to handle the various shared and private pointer types that are available in UPC. The optimizations also take advantage of UPC's relaxed memory consistency model, which reduces the need for cross thread analysis. We demonstrate the effectiveness of the analysis and optimizations using several benchmarks, which were chosen to reflect the kinds of fine-grained, communication-intensive phases that exist in some larger applications. The optimizations show speedups of up to 70 percent on three parallel systems, which represent three different types of cluster network technologies.

  7. Subset Feature Learning for Fine-Grained Category Classification

    OpenAIRE

    Ge, Zongyuan; McCool, Christopher; Sanderson, Conrad; Corke, Peter

    2015-01-01

    Fine-grained categorisation has been a challenging problem due to small inter-class variation, large intra-class variation and low number of training images. We propose a learning system which first clusters visually similar classes and then learns deep convolutional neural network features specific to each subset. Experiments on the popular fine-grained Caltech-UCSD bird dataset show that the proposed method outperforms recent fine-grained categorisation methods under the most difficult sett...

  8. Deformation of fine-grained synthetic peridotite under wet conditions

    NARCIS (Netherlands)

    McDonnell, R.D.

    1997-01-01

    Fine-grained hydrated peridotite mylonites have been proposed to play an important role in controlling the strength of the continental lithosphere during rifting. For this reason, the deformation behaviour of wet fine-grained forsterite and forsterite-enstatite materials and the underlying deformati

  9. Fine-grained representation learning in convolutional autoencoders

    Science.gov (United States)

    Luo, Chang; Wang, Jie

    2016-03-01

    Convolutional autoencoders (CAEs) have been widely used as unsupervised feature extractors for high-resolution images. As a key component in CAEs, pooling is a biologically inspired operation to achieve scale and shift invariances, and the pooled representation directly affects the CAEs' performance. Fine-grained pooling, which uses small and dense pooling regions, encodes fine-grained visual cues and enhances local characteristics. However, it tends to be sensitive to spatial rearrangements. In most previous works, pooled features were obtained by empirically modulating parameters in CAEs. We see the CAE as a whole and propose a fine-grained representation learning law to extract better fine-grained features. This representation learning law suggests two directions for improvement. First, we probabilistically evaluate the discrimination-invariance tradeoff with fine-grained granularity in the pooled feature maps, and suggest the proper filter scale in the convolutional layer and appropriate whitening parameters in preprocessing step. Second, pooling approaches are combined with the sparsity degree in pooling regions, and we propose the preferable pooling approach. Experimental results on two independent benchmark datasets demonstrate that our representation learning law could guide CAEs to extract better fine-grained features and performs better in multiclass classification task. This paper also provides guidance for selecting appropriate parameters to obtain better fine-grained representation in other convolutional neural networks.

  10. Process for preparing fine grain silicon carbide powder

    Science.gov (United States)

    Wei, G.C.

    Method of producing fine-grain silicon carbide powder comprises combining methyltrimethoxysilane with a solution of phenolic resin, acetone and water or sugar and water, gelling the resulting mixture, and then drying and heating the obtained gel.

  11. Fine-grained sediment dispersal along the California coast

    Science.gov (United States)

    Warrick, Jonathan A.; Storlazzi, Curt D.

    2013-01-01

    Fine-grained sediment (silt and clay) enters coastal waters from rivers, eroding coastal bluffs, resuspension of seabed sediment, and human activities such as dredging and beach nourishment. The amount of sediment in coastal waters is an important factor in ocean ecosystem health, but little information exists on both the natural and human-driven magnitudes of fine-grained sediment delivery to the coastal zone, its residence time there, and its transport out of the system—information upon which to base environmental assessments. To help fill these information gaps, the U.S. Geological Survey has partnered with Federal, State, and local agencies to monitor fine-grained sediment dispersal patterns and fate in the coastal regions of California. Results of these studies suggest that the waves and currents of many of the nearshore coastal settings of California are adequately energetic to transport fine-grained sediment quickly through coastal systems. These findings will help with the management and regulation of fine-grained sediment along the U.S. west coast.

  12. Development of High Sensitivity Nuclear Emulsion and Fine Grained Emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Kawahara, H.; Asada, T. [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Naka, T. [Institute of Advanced Research, Nagoya University (Japan); Naganawa, N.; Kuwabara, K.; Nakamura, M. [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

    2014-08-15

    Nuclear emulsion is a particle detector having high spacial resolution and angular resolution. It became useful for large statistics experiment thanks to the development of automatic scanning system. In 2010, a facility for emulsion production was introduced and R and D of nuclear emulsion began at Nagoya university. In this paper, we present results of development of the high sensitivity emulsion and fine grained emulsion for dark matter search experiment. Improvement of sensitivity is achieved by raising density of silver halide crystals and doping well-adjusted amount of chemicals. Production of fine grained emulsion was difficult because of unexpected crystal condensation. By mixing polyvinyl alcohol (PVA) to gelatin as a binder, we succeeded in making a stable fine grained emulsion.

  13. Facilitating Fine Grained Data Provenance using Temporal Data Model

    NARCIS (Netherlands)

    Huq, M.R.; Wombacher, Andreas; Apers, Peter M.G.

    2010-01-01

    E-science applications use fine grained data provenance to maintain the reproducibility of scientific results, i.e., for each processed data tuple, the source data used to process the tuple as well as the used approach is documented. Since most of the e-science applications perform on-line

  14. Probabilistic inference of fine-grained data provenance

    NARCIS (Netherlands)

    Huq, Mohammad Rezwanul; Apers, P.M.G.; Wombacher, A.

    2012-01-01

    Decision making, process control and e-science applications process stream data, mostly produced by sensors. To control and monitor these applications, reproducibility of result is a vital requirement. However, it requires massive amount of storage space to store fine-grained provenance data especia

  15. Mechanical properties of ultra-fine grained zirconia ceramics

    NARCIS (Netherlands)

    Theunissen, G.S.A.M.; Bouma, J.S.; Winnubst, A.J.A.; Burggraaf, A.J.

    1992-01-01

    The mechanical properties of tetragonal zirconia (TZP) materials doped with Y, Ce or Ti were studied as a function of temperature and grain size. Fine grained Y-TZP (grain size < 0.3 mgrm) shows values for fracture toughness and strength at room temperature, which are comparable with the coarse grai

  16. Neutrino Induced Coherent ρ Production in a Fine Grained Tracker

    Science.gov (United States)

    Jiang, Libo; Kullenberg, Christpher; Tian, Xinchun; Mishra, Sanjib; LBNE Collaboration

    2015-04-01

    We present simulation of neutrino induced coherent ρ-meson production in charged and neutral current interactions. Sensitivity studies of this process is presented in a fine grain tracker, a near detector option for LBNE. Measurements of coherent ρ0 and ρ+ production in NOMAD are reported.

  17. Ultra-Fine Grained Dual-Phase Steels

    Directory of Open Access Journals (Sweden)

    Matthias Militzer

    2012-10-01

    Full Text Available This paper provides an overview on obtaining low-carbon ultra-fine grained dual-phase steels through rapid intercritical annealing of cold-rolled sheet as improved materials for automotive applications. A laboratory processing route was designed that involves cold-rolling of a tempered martensite structure followed by a second tempering step to produce a fine grained aggregate of ferrite and carbides as the initial microstructure for rapid intercritical annealing. The intercritical annealing step was performed with heating and cooling rates of at least 100 °C/s and a holding time of 30 s. The intercritical temperature was selected to result in 20- 35% martensite in the final microstructures for C-Mn steels with carbon contents of 0.06, 0.12 and 0.17 wt%, respectively. The proposed processing routes produced an ultra-fine grained ferrite-martensite structure withgrain sizes of approximately 1 ?m for all three steels. The tensile strength of these ultra-fine grained dualphase steels can be increased by up to 200 MPa as compared to coarse-grained dual-phase steels while maintaining uniform elongation values. The rather narrow processing window necessary to obtain these properties was evaluated by determining the effect of intercritical annealing conditions on microstructure evolution. Further, the experimental results were confirmed with phase field simulations of austenite formation indicating that rapid heat treatment cycles are essential to obtain fine grained intercritical austenite that leads to martensite islands with sizes of 1 ?m and below in the final microstructure.

  18. Diffused phase transition in fine-grained bismuth vanadate ceramics

    OpenAIRE

    Shantha, K; Varma, KBR

    1999-01-01

    Nanocrystalline powders of ferroelectric bismuth vanadate, Bi4V2O11 (n-BiV), with crystallite size less than 50 nm, were obtained by mechanical milling of a stoichiometric mixture of bismuth oxide and vanadium pentoxide. The n-BiV powders on sintering yielded high-density, fine-grained ceramics with improved dielectric and polar characteristics. Dielectric studies on samples obtained from milled powders indicated that the ferroelectric-to-paraelectric phase transition temperature is strongly ...

  19. Detection and fine-grained classification of cyberbullying events

    OpenAIRE

    Van Hee, Cynthia; Lefever, Els; Verhoeven, Ben; Mennes, Julie; Desmet, Bart; De Pauw, Guy; Daelemans, Walter; Hoste, Veronique

    2015-01-01

    In the current era of online interactions, both positive and negative experiences are abundant on the Web. As in real life, negative experiences can have a serious impact on youngsters. Recent studies have reported cybervictimization rates among teenagers that vary between 20% and 40%. In this paper, we focus on cyberbullying as a particular form of cybervictimization and explore its automatic detection and fine-grained classification. Data containing cyberbullying was collected from the soci...

  20. Weldability investigation of fine-grained S1100QL steel

    Directory of Open Access Journals (Sweden)

    I. Samardžić

    2016-07-01

    Full Text Available This paper presents the results of weldability investigation on welded joints made of fine - grained high-strength S1100QL steel. The investigations are performed on two welded plates by HV 10 hardness measuring and by Charpy V notch testing at different test temperatures. Mechanical properties of welded joints are overviewed, along with welded parameters, all of which enable obtaining of high-quality welded joints.

  1. Resonance interaction in LBNE fine-grained-tracker near detector

    Energy Technology Data Exchange (ETDEWEB)

    Duyang, Hongyue; Tian, Xinchun; Mishra, Sanjib R. [Department of Physics and Astronomy, University of South Carolina, 712 Main St, Columbia, SC 29208 (United States)

    2015-10-15

    This talk is devoted to resonance interaction (RES) in the proposed fine-grained tracker detector (FGT) for LBNE experiment. We use fast MC to study the sensitivity of FGT to RES, and use this measurement as a handle to constrain nuclear effects. Similar analysis is performed on NOMAD data for validation and better understanding. Preliminary RES measurement result using NOMAD data will be reported.

  2. Resonance interaction in LBNE fine-grained-tracker near detector

    Science.gov (United States)

    Duyang, Hongyue; Tian, Xinchun; Mishra, Sanjib R.

    2015-10-01

    This talk is devoted to resonance interaction (RES) in the proposed fine-grained tracker detector (FGT) for LBNE experiment. We use fast MC to study the sensitivity of FGT to RES, and use this measurement as a handle to constrain nuclear effects. Similar analysis is performed on NOMAD data for validation and better understanding. Preliminary RES measurement result using NOMAD data will be reported.

  3. Process for preparing fine-grain metal carbide powder

    Science.gov (United States)

    Kennedy, C.R.; Jeffers, F.P.

    Fine-grain metal carbide powder suitable for use in the fabrication of heat resistant products is prepared by coating bituminous pitch on SiO/sub 2/ or Ta/sub 2/O/sub 5/ particles, heating the coated particles to convert the bituminous pitch to coke, and then heating the particles to a higher temperature to convert the particles to a carbide by reaction of said coke therewith.

  4. A RAMP CODE FOR FINE-GRAINED ACCESS CONTROL

    Directory of Open Access Journals (Sweden)

    Kannan Karthik

    2013-02-01

    Full Text Available Threshold ramp secret sharing schemes are designed so that (i certain subsets of shares have no information about the secret, (ii some subsets have partial information about the secret and (iii some subsets have complete information to recover the secret. However most of the ramp schemes in present literature do not control the leakage of information in partial access sets, due to which the information acquired by these sets is devoid of structure and not useful for fine-grained access control. Through a non-perfect secret sharing scheme called MIX-SPLIT, an encoding methodology for controlling the leakage in partial access sets is proposed and this is used for fine-grained access to binary strings. The ramp code generated using MIX-SPLIT requires a much smaller share size of O(n, as compared to Shamir's ramp adaptation which incurs a share size of atleast O(n2 for the same multi-access structure. The proposed ramp code is finally applied towards the protection and fine-grained access of industrial design drawings.

  5. Mid frequency shallow water fine-grained sediment attenuation measurements.

    Science.gov (United States)

    Holland, Charles W; Dosso, Stan E

    2013-07-01

    Attenuation is perhaps the most difficult sediment acoustic property to measure, but arguably one of the most important for predicting passive and active sonar performance. Measurement techniques can be separated into "direct" measurements (e.g., via sediment probes, sediment cores, and laboratory studies on "ideal" sediments) which are typically at high frequencies, O(10(4)-10(5)) Hz, and "indirect" measurements where attenuation is inferred from long-range propagation or reflection data, generally O(10(2)-10(3)) Hz. A frequency gap in measurements exists in the 600-4000 Hz band and also a general acknowledgement that much of the historical measurements on fine-grained sediments have been biased due to a non-negligible silt and sand component. A shallow water measurement technique using long range reverberation is critically explored. An approximate solution derived using energy flux theory shows that the reverberation is very sensitive to depth-integrated attenuation in a fine-grained sediment layer and separable from most other unknown geoacoustic parameters. Simulation using Bayesian methods confirms the theory. Reverberation measurements across a 10 m fine-grained sediment layer yield an attenuation of 0.009 dB/m/kHz with 95% confidence bounds of 0.006-0.013 dB/m/kHz. This is among the lowest values for sediment attenuation reported in shallow water.

  6. Low-velocity ion tracks in fine grain emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Natsume, M. [F-lab., Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)]. E-mail: natsume@flab.phys.nagoya-u.ac.jp; Hoshino, K. [F-lab., Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Kuwabara, K. [Digital and Photo Imaging Materials Research Laboratories, FUJIFILM Corporation, Minamiashigara, Kanagawa 250-0193 (Japan); Nakamura, M. [F-lab., Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Nakano, T. [F-lab., Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Niwa, K. [F-lab., Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Sato, O. [F-lab., Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Tani, T. [Digital and Photo Imaging Materials Research Laboratories, FUJIFILM Corporation, Minamiashigara, Kanagawa 250-0193 (Japan); Toshito, T. [F-lab., Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

    2007-06-01

    We have studied low-velocity Kr ion responses of nuclear emulsions for the possibility of tracking Ag and Br recoils from galactic dark matter particles. Tracks of 680-1180 km/s Kr ions have been observed in a 40 nm-sized AgBr grain emulsion with scanning electron microscopy. The tracks have a linear energy-dependency in range, angles biased along the incident direction, and a high developed-grain number density with respect to expected electronic stopping. We find that the fine grain emulsion is sensitive enough to low-velocity heavy ions whose energy losses are mainly governed by nuclear stopping.

  7. Lime stabilization of fine-grained sediments in western Greenland

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr; Ingeman-Nielsen, Thomas; Skels, Peteris

    2011-01-01

    due to the cold climate, and it is therefore of great interest to study possible methods to improve the stability and strength properties. This project includes laboratory studies of lime stabilization on fine-grained marine sediments from Kangerlussuaq, western Greenland. The results have included...... tests to determine the optimum lime content and the strength development in relation to both reaction time and curing temperature. Hopefully the results from this project will lead to a future use of lime stabilization and make it possible to use/reuse materials of poor quality at construction sites...

  8. Fine-Grained Turbidites: Facies, Attributes and Process Implications

    Science.gov (United States)

    Stow, Dorrik; Omoniyi, Bayonle

    2016-04-01

    Within turbidite systems, fine-grained sediments are still the poor relation and sport several contrasting facies models linked to process of deposition. These are volumetrically the dominant facies in deepwater and, from a resource perspective, they form important marginal and tight reservoirs, and have great potential for unconventional shale gas, source rocks and seals. They are also significant hosts of metals and rare earth elements. Based on a large number of studies of modern, ancient and subsurface systems, including 1000s of metres of section logging, we define the principal genetic elements of fine-grained deepwater facies, present a new synthesis of facies models and their sedimentary attributes. The principal architectural elements include: non-channelised slope-aprons, channel-fill, channel levee and overbank, turbidite lobes, mass-transport deposits, contourite drifts, basin sheets and drapes. These comprise a variable intercalation of fine-grained facies - thin-bedded and very thin-bedded turbidites, contourites, hemipelagites and pelagites - and associated coarse-grained facies. Characteristic attributes used to discriminate between these different elements are: facies and facies associations; sand-shale ratio, sand and shale geometry and dimensions, sand connectivity; sediment texture and small-scale sedimentary structures; sediment fabric and microfabric; and small-scale vertical sequences of bed thickness. To some extent, we can relate facies and attribute characteristics to different depositional environments. We identify four distinct facies models: (a) silt-laminated mud turbidites, (b) siliciclastic mud turbidites, (c) carbonate mud turbidites, (d) disorganized silty-mud turbidites, and (e) hemiturbidites. Within the grainsize-velocity matrix turbidite plot, these all fall within the region of mean size < 0.063mm, maximum grainsize (one percentile) <0.2mm, and depositional velocity 0.1-0.5 m/s. Silt-laminated turbidites and many mud

  9. High Heat Load Properties of Ultra Fine Grain Tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Z.; Du, J.; Ge, C. [Lab. of Special Ceramic and P/M, University of Science and Technology, 100083 Beijing (China); Linke, J.; Pintsuk, G. [FZJ-Forschungszentrum Juelich GmbH, Association Euratom-FZJ, Institut fur Plasmaphysik, Postfach 1913, D-52425 Juelich (Germany); Song, S.X. [Research Center on Fusion Materials (RCFM), University of Science and Technology Beijing (USTB), 100083 Beijing (China)

    2007-07-01

    Full text of publication follows: Tungsten is increasingly considered as a promising candidate armour materials facing the plasma in tokamaks for medium to high heat flux components (EAST, ASDEX, ITER). Fabrication tungsten with ultra fine grain size is considered as an effective way to ameliorate some disadvantages of tungsten, such as its brittleness at room temperature. But the research data on the performance of ultra fine grain tungsten is still very limit. In this work, high heat load properties of pure ultra-fine grain tungsten have been studied. The ultra fine grain tungsten samples with average grain size of 0.2 {mu}m, 1 {mu}m and 3 {mu}m were fabricated by resistance sintering under ultra high pressure. The annealing experiments for the investigation of the material resistance against grain growth have been done by annealing samples in a vacuum furnace at different temperature holding for 2 hours respectively. It is found that recrystallization and grain growth occur at heating temperature of 1250 deg. c. The finer the initial grain sizes of tungsten, the smaller its grain growth grain. The effects of transient high thermal loads (off normal events like disruptions) on tungsten surface morphology have been performed in electron beam test facility JUDITH. The thermal loads tests have been carried out with 4 ms pulses at different power density of 0.22, 0.33, 0.44, 0.55 and 0.88 GW/m{sup 2} respectively. Horizontal cracks formed for all tungsten samples at 0.44 GW/m{sup 2}. Particle erosions occurred for tungsten with 3 {mu}m size at 0.33 GW/m{sup 2} and for tungsten with 0.2 and 1 {mu}m size at 0.55 GW/m{sup 2}. The weight loss of tungsten with 0.2, 1 and 3 {mu}m size are 2,0.1,0.6 mg respectively at 0.88 GW/m{sup 2}. The effects of a large number of very short transient repetitive thermal loads (ELM-like) on tungsten surface morphology also have been performed by using a fundamental wave of a YAG laser. It is found that tungsten with 0.2 {mu}m size has

  10. Genetic Effects on Fine-Grained Human Cortical Regionalization.

    Science.gov (United States)

    Cui, Yue; Liu, Bing; Zhou, Yuan; Fan, Lingzhong; Li, Jin; Zhang, Yun; Wu, Huawang; Hou, Bing; Wang, Chao; Zheng, Fanfan; Qiu, Chengxiang; Rao, Li-Lin; Ning, Yuping; Li, Shu; Jiang, Tianzi

    2016-09-01

    Various brain structural and functional features such as cytoarchitecture, topographic mapping, gyral/sulcal anatomy, and anatomical and functional connectivity have been used in human brain parcellation. However, the fine-grained intrinsic genetic architecture of the cortex remains unknown. In the present study, we parcellated specific regions of the cortex into subregions based on genetic correlations (i.e., shared genetic influences) between the surface area of each pair of cortical locations within the seed region. The genetic correlations were estimated by comparing the correlations of the surface area between monozygotic and dizygotic twins using bivariate twin models. Our genetic subdivisions of diverse brain regions were reproducible across 2 independent datasets and corresponded closely to fine-grained functional specializations. Furthermore, subregional genetic correlation profiles were generally consistent with functional connectivity patterns. Our findings indicate that the magnitude of the genetic covariance in brain anatomy could be used to delineate the boundaries of functional subregions of the brain and may be of value in the next generation human brain atlas.

  11. Power Characterisation for Fine-Grain Reconfigurable Fabrics

    Directory of Open Access Journals (Sweden)

    Tobias Becker

    2010-01-01

    Full Text Available This paper proposes a benchmarking methodology for characterising the power consumption of the fine-grain fabric in reconfigurable architectures. This methodology is part of the GroundHog 2009 power benchmarking suite. It covers active and inactive power as well as advanced low-power modes. A method based on random number generators is adopted for comparing activity modes. We illustrate our approach using five field-programmable gate arrays (FPGAs that span a range of process technologies: Xilinx Virtex-II Pro, Spartan-3E, Spartan-3AN, Virtex-5, and Silicon Blue iCE65. We find that, despite improvements through process technology and low-power modes, current devices need further improvements to be sufficiently power efficient for mobile applications. The Silicon Blue device demonstrates that performance can be traded off to achieve lower leakage.

  12. Olivine and Pyroxene Compositions in Fine-Grained Chondritic Materials

    Science.gov (United States)

    Zolensky, Michael E.; Frank, D.

    2011-01-01

    Our analyses of the Wild-2 samples returned by the Stardust Mission have illuminated critical gaps in our understanding of related astromaterials. There is a very large database of olivine and low-calcium pyroxene compositions for coarse-grained components of chondrites, but a sparse database for anhydrous silicate matrix phases. In an accompanying figure, we present comparisons of Wild-2 olivine with the available chondrite matrix olivine major element data. We thus have begun a long-term project measuring minor as well as major element compositions for chondrite matrix and chondritic IDPs, and Wild 2 grains. Finally, we wish to re-investigate the changes to fine-grained olivine and low-Ca pyroxene composition with progressive thermal metamorphism. We have examined the LL3-4 chondrites which because of the Hayabusa Mission have become very interesting.

  13. Fine-grained uncertainty relation under the relativistic motion

    CERN Document Server

    Feng, Jun; Gould, Mark D; Fan, Heng

    2014-01-01

    One of the most important features of quantum theory is the uncertainty principle. Amount various uncertainty relations, the profound Fine-Grained Uncertainty Relation (FGUR) is used to distinguish the uncertainty inherent in obtaining any combination of outcomes for different measurements. In this paper, we explore this uncertainty relation in relativistic regime. For observer undergoes an uniform acceleration who immersed in an Unruh thermal bath, we show that the uncertainty bound is dependent on the acceleration parameter and choice of Unruh modes. Dramatically, we find that the measurements in Mutually Unbiased Bases (MUBs), sharing same uncertainty bound in inertial frame, could be distinguished from each other for a noninertial observer. On the other hand, once the Unruh decoherence is prevented by utilizing the cavity, the entanglement could be generated from nonuniform motion. We show that, for the observer restricted in a single rigid cavity, the uncertainty exhibits a periodic evolution with respec...

  14. Measurements of The Neutrino Flux Using Fine-Grained Tracker

    Science.gov (United States)

    Tian, Xinchun; Mishra, Sanjib; Petti, Roberto; Duyang, Hongyue; LBNE Collaboration

    2015-04-01

    The reference design of the near detector for the LBNE/F experiment is a high-resolution Fine-Grained Tracker (FGT) capable of precisely measuring all four species of neutrinos: νμ, νe, νμ and νe. The goals of the FGT is to constrain the systematic errors, below the corresponding statistical error in the far detector, for all oscillation studies; and to conduct a panoply of precision measurements and searches in neutrino physics. We present sensitivity studies - critical to constraining the systematics in oscillation searches - of measurements of the absolute and relative neutrino flux using the various techniques: 1) neutrino electron NC (CC) scattering, 2) νμ proton QE scattering, 3) Coherent ρ production for absolute flux and 4) Low- ν method for relative flux.

  15. Metadata for fine-grained processing at ATLAS

    CERN Document Server

    Cranshaw, Jack; The ATLAS collaboration

    2016-01-01

    High energy physics experiments are implementing highly parallel solutions for event processing on resources that support concurrency at multiple levels. These range from the inherent large-scale parallelism of HPC resources to the multiprocessing and multithreading needed for effective use of multi-core and GPU-augmented nodes. Such modes of processing, and the efficient opportunistic use of transiently-available resources, lead to finer-grained processing of event data. Previously metadata systems were tailored to jobs that were atomic and processed large, well-defined units of data. The new environment requires a more fine-grained approach to metadata handling, especially with regard to bookkeeping. For opportunistic resources metadata propagation needs to work even if individual jobs are not finalized. This contribution describes ATLAS solutions to this problem in the context of the multiprocessing framework currently in use for LHC Run 2, development underway for the ATLAS multithreaded framework (Athena...

  16. OLLAF: A Fine Grained Dynamically Reconfigurable Architecture for OS Support

    Directory of Open Access Journals (Sweden)

    Garcia Samuel

    2009-01-01

    Full Text Available Fine Grained Dynamically Reconfigurable Architecture (FGDRA offers a flexibility for embedded systems with a great power processing efficiency by exploiting optimizations opportunities at architectural level thanks to their fine configuration granularity. But this increase design complexity that should be abstracted by tools and operating system. In order to have a usable solution, a good inter-overlapping between tools, OS, and platform must exist. In this paper we present OLLAF, an FGDRA specially designed to efficiently support an OS. The studies presented here show the contribution of this architecture in terms of hardware context management and preemption support. Studies presented here show the gain that can be obtained, by using OLLAF instead of a classical FPGA, in terms of context management and preemption overhead.

  17. Object Instance Segmentation and Fine-Grained Localization Using Hypercolumns.

    Science.gov (United States)

    Hariharan, Bharath; Arbelaez, Pablo; Girshick, Ross; Malik, Jitendra

    2017-04-01

    Recognition algorithms based on convolutional networks (CNNs) typically use the output of the last layer as a feature representation. However, the information in this layer may be too coarse spatially to allow precise localization. On the contrary, earlier layers may be precise in localization but will not capture semantics. To get the best of both worlds, we define the hypercolumn at a pixel as the vector of activations of all CNN units above that pixel. Using hypercolumns as pixel descriptors, we show results on three fine-grained localization tasks: simultaneous detection and segmentation, where we improve state-of-the-art from 49.7 mean AP(r) to 62.4, keypoint localization, where we get a 3.3 point boost over a strong regression baseline using CNN features, and part labeling, where we show a 6.6 point gain over a strong baseline.

  18. METHODS OF RECEIVING OF FINE-GRAINED STRUCTURE OF CASTINGS AT CRYSTALLIZATION

    Directory of Open Access Journals (Sweden)

    N. K. Tolochko

    2012-01-01

    Full Text Available The article deals with methods for fine-grained structure of ingots during crystallization depending on the used foundry technologies. It is shown that by using modern scientific and technological advances may improve the traditional and the development of new casting processes, providing production of cast parts with over fine-grained structure and enhanced properties.

  19. The T2K fine-grained detectors

    Energy Technology Data Exchange (ETDEWEB)

    Amaudruz, P.-A. [TRIUMF, Vancouver, British Columbia (Canada); Barbi, M. [University of Regina, Physics Department, Regina, Saskatchewan (Canada); Bishop, D. [TRIUMF, Vancouver, British Columbia (Canada); Braam, N. [University of Victoria, Department of Physics and Astronomy, Victoria, British Columbia (Canada); Brook-Roberge, D.G. [University of British Columbia, Department of Physics and Astronomy, Vancouver, British Columbia (Canada); Giffin, S. [University of Regina, Physics Department, Regina, Saskatchewan (Canada); Gomi, S. [Kyoto University, Department of Physics, Kyoto (Japan); Gumplinger, P.; Hamano, K. [TRIUMF, Vancouver, British Columbia (Canada); Hastings, N.C. [University of Regina, Physics Department, Regina, Saskatchewan (Canada); Hastings, S. [University of British Columbia, Department of Physics and Astronomy, Vancouver, British Columbia (Canada); Helmer, R.L., E-mail: helmer@triumf.ca [TRIUMF, Vancouver, British Columbia (Canada); Henderson, R. [TRIUMF, Vancouver, British Columbia (Canada); Ieki, K. [Kyoto University, Department of Physics, Kyoto (Japan); Jamieson, B. [University of British Columbia, Department of Physics and Astronomy, Vancouver, British Columbia (Canada); Kato, I.; Khan, N. [TRIUMF, Vancouver, British Columbia (Canada); Kim, J.; Kirby, B. [University of British Columbia, Department of Physics and Astronomy, Vancouver, British Columbia (Canada); Kitching, P. [University of Alberta, Centre for Particle Physics, Department of Physics, Edmonton, Alberta (Canada); and others

    2012-12-22

    T2K is a long-baseline neutrino oscillation experiment searching for {nu}{sub e} appearance in a {nu}{sub {mu}} beam. The beam is produced at the J-PARC accelerator complex in Tokai, Japan, and the neutrinos are detected by the Super-Kamiokande detector located 295 km away in Kamioka. A suite of near detectors (ND280) located 280 m downstream of the production target is used to characterize the components of the beam before they have had a chance to oscillate and to better understand various neutrino interactions on several nuclei. This paper describes the design and construction of two massive fine-grained detectors (FGDs) that serve as active targets in the ND280 tracker. One FGD is composed solely of scintillator bars while the other is partly scintillator and partly water. Each element of the FGDs is described, including the wavelength shifting fiber and Multi-Pixel Photon Counter used to collect the light signals, the readout electronics, and the calibration system. Initial tests and in situ results of the FGDs' performance are also presented.

  20. Laser Welding of Ultra-Fine Grained Steel SS400

    Institute of Scientific and Technical Information of China (English)

    PENG Yun; TIAN Zhi-ling; CHEN Wu-zhu; WANG Cheng; BAO Gang

    2003-01-01

    The effects of laser welding on microstructure and mechanical properties of ultra-fine grained steel SS400 were studied. The plasma arc welding and MAG welding were conducted to make a comparison between these weldings and laser welding. The coarse grain heat-affected zone (HAZ) of laser welding was simulated using thermomechanical simulation machine, and the impact toughness was tested. The deep penetration laser welding produces weld of large depth and narrow width. The weld metal and HAZ of laser welding was heated and then cooled rapidly. The prior austenite grain size of coarse grain HAZ is 1/10 of that for arc welding. For laser welding, the toughness of weld metal is higher than that of base metal, and the toughness of the coarse grain HAZ of laser welding is on a level with that of base metal. Matching lower laser power with lower welding speed, the hardening tendency of the weld metal and the coarse grain HAZ can be decreased. There is no softened zone. The tensile strength of welded joint formed by laser is higher than that of base metal. The joint has good bending ductility.

  1. Fine-Grained Access Control for Electronic Health Record Systems

    Science.gov (United States)

    Hue, Pham Thi Bach; Wohlgemuth, Sven; Echizen, Isao; Thuy, Dong Thi Bich; Thuc, Nguyen Dinh

    There needs to be a strategy for securing the privacy of patients when exchanging health records between various entities over the Internet. Despite the fact that health care providers such as Google Health and Microsoft Corp.'s Health Vault comply with the U.S Health Insurance Portability and Accountability Act (HIPAA), the privacy of patients is still at risk. Several encryption schemes and access control mechanisms have been suggested to protect the disclosure of a patient's health record especially from unauthorized entities. However, by implementing these approaches, data owners are not capable of controlling and protecting the disclosure of the individual sensitive attributes of their health records. This raises the need to adopt a secure mechanism to protect personal information against unauthorized disclosure. Therefore, we propose a new Fine-grained Access Control (FGAC) mechanism that is based on subkeys, which would allow a data owner to further control the access to his data at the column-level. We also propose a new mechanism to efficiently reduce the number of keys maintained by a data owner in cases when the users have different access privileges to different columns of the data being shared.

  2. Exploiting fine-grain parallelism in recursive LU factorization

    KAUST Repository

    Dongarra, Jack

    2012-01-01

    The LU factorization is an important numerical algorithm for solving system of linear equations. This paper proposes a novel approach for computing the LU factorization in parallel on multicore architectures. It improves the overall performance and also achieves the numerical quality of the standard LU factorization with partial pivoting. While the update of the trailing submatrix is computationally intensive and highly parallel, the inherently problematic portion of the LU factorization is the panel factorization due to its memory-bound characteristic and the atomicity of selecting the appropriate pivots. We remedy this in our new approach to LU factorization of (narrow and tall) panel submatrices. We use a parallel fine-grained recursive formulation of the factorization. It is based on conflict-free partitioning of the data and lock-less synchronization mechanisms. Our implementation lets the overall computation naturally flow with limited contention. Our recursive panel factorization provides the necessary performance increase for the inherently problematic portion of the LU factorization of square matrices. A large panel width results in larger Amdahl\\'s fraction as our experiments have revealed which is consistent with related efforts. The performance results of our implementation reveal superlinear speedup and far exceed what can be achieved with equivalent MKL and/or LAPACK routines. © 2012 The authors and IOS Press. All rights reserved.

  3. Benzene and MTBE Sorption in Fine Grain Sediments

    Science.gov (United States)

    Leal-Bautista, R. M.; Lenczewski, M. E.

    2003-12-01

    The practice of adding methyl tert-butyl ether (MTBE) to gasoline started in the late 1970s and increased dramatically in the 1990s. MTBE first was added as a substitute for tetra-ethyl lead then later as a fuel oxygenate. Although the use of MTBE has resulted in significant reduction in air pollution, it has become a significant groundwater contaminant due to its high solubility in water, high environmental mobility, and low potential for biodegradation. A recent report (1999-2001) by the Metropolitan Water District of Southern California in collaboration with United State Geological Survey and the Oregon Health and Science University found that MTBE was the second most frequent detected volatile organic compound in groundwater. In Illinois, MTBE has been found in 26 of the 1,800 public water supplies. MTBE has also been blended in Mexico into two types of gasoline sold in the country by the state oil company (PEMEX) but is not monitored in groundwater at this time. Early research on MTBE considered it unable to adsorb to soils and sediments, however, by increasing the organic matter and decreasing the size of the grains (silts or clays) this may increase sorption. The objective of this study is to determine if fine grained materials have the potential for sorption of MTBE due to its high specific surface area (10-700 m 2/g) and potentially high organic matter (0.5-3.8%). The experiment consisted of sorption isotherms to glacial tills from DeKalb, Illinois and lacustrine clays from Chalco, Mexico. Experiments were performed with various concentrations of MTBE and benzene (10, 50, 100, 500 and 1000 ug/L) at 10° C and 25° C. Results showed a range of values for the distribution coefficient (Kd, linear model). At 10° C the Kd value for MTBE was 0.187 mL/g for lacustrine clay while the glacial loess had a value of 0.009 mL/g. The highest Kd values with MTBE were 0.2859 mL/g for organic rich lacustrine clays and 0.014 mL/g for glacial loess at 25° C. The highest

  4. Study of a Fine Grained Threaded Framework Design

    Science.gov (United States)

    Jones, C. D.

    2012-12-01

    Traditionally, HEP experiments exploit the multiple cores in a CPU by having each core process one event. However, future PC designs are expected to use CPUs which double the number of processing cores at the same rate as the cost of memory falls by a factor of two. This effectively means the amount of memory per processing core will remain constant. This is a major challenge for LHC processing frameworks since the LHC is expected to deliver more complex events (e.g. greater pileup events) in the coming years while the LHC experiment's frameworks are already memory constrained. Therefore in the not so distant future we may need to be able to efficiently use multiple cores to process one event. In this presentation we will discuss a design for an HEP processing framework which can allow very fine grained parallelization within one event as well as supporting processing multiple events simultaneously while minimizing the memory footprint of the job. The design is built around the libdispatch framework created by Apple Inc. (a port for Linux is available) whose central concept is the use of task queues. This design also accommodates the reality that not all code will be thread safe and therefore allows one to easily mark modules or sub parts of modules as being thread unsafe. In addition, the design efficiently handles the requirement that events in one run must all be processed before starting to process events from a different run. After explaining the design we will provide measurements from simulating different processing scenarios where the processing times used for the simulation are drawn from processing times measured from actual CMS event processing.

  5. Geochemistry of Fine-grained Sediments and Sedimentary Rocks

    Science.gov (United States)

    Sageman, B. B.; Lyons, T. W.

    2003-12-01

    paleosalinity). Authors of a single chapter can hope, at best, to present a cursory glance at the many biogeochemical proxies currently used and under development in sedimentary studies. Our goal, instead, is to focus on a selected suite of tools of particular value in the reconstruction of paleo-environments preserved in fine-grained siliciclastic sedimentary rocks.Fine-grained, mixed siliciclastic-biogenic sedimentary facies - commonly termed hemipelagic (mainly calcareous or siliceous mudrocks containing preserved organic matter (OM)) - are ideal for unraveling the geological past and are thus the focus of this chapter. These strata accumulate in predominantly low-energy basinal environments where the magnitude (and frequency) of lacunae is diminished, resulting in relatively continuous, though generally condensed sequences. Fortunately, condensation tends to benefit geochemical analysis as it helps to amplify some subtle environmental signals. Because hemipelagic facies include contributions from both terrigenous detrital and pelagic biogenic systems, as well as from authigenic components reflecting the burial environment (Figure 1), they are rich archives of geochemical information. In this chapter we present a conceptual model linking the major processes of detrital, biogenic, and authigenic accumulation in fine-grained hemipelagic settings. This model is intended to be a fresh synthesis of decades of prior research on the geochemistry of modern and ancient mudrocks, including our own work.

  6. Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

    Institute of Scientific and Technical Information of China (English)

    TAN Ying-xin; TAN Ru-mei; ZHANG Jing-lin

    2005-01-01

    The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1mm. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.

  7. Decoherent Histories Quantum Mechanics with One 'Real' Fine-Grained History

    CERN Document Server

    Gell-Mann, Murray

    2012-01-01

    Decoherent histories quantum theory is reformulated with the assumption that there is one "real" fine-grained history, specified in a preferred complete set of sum-over-histories variables. This real history is described by embedding it in an ensemble of comparable imagined fine-grained histories, not unlike the familiar ensemble of statistical mechanics. These histories are assigned extended probabilities, which can sometimes be negative or greater than one. As we will show, this construction implies that the real history is not completely accessible to experimental or other observational discovery. However, sufficiently and appropriately coarse-grained sets of alternative histories have standard probabilities providing information about the real fine-grained history that can be compared with observation. We recover the probabilities of decoherent histories quantum mechanics for sets of histories that are recorded and therefore decohere. Quantum mechanics can be viewed as a classical stochastic theory of his...

  8. Learning Category-Specific Dictionary and Shared Dictionary for Fine-Grained Image Categorization.

    Science.gov (United States)

    Gao, Shenghua; Tsang, Ivor Wai-Hung; Ma, Yi

    2014-02-01

    This paper targets fine-grained image categorization by learning a category-specific dictionary for each category and a shared dictionary for all the categories. Such category-specific dictionaries encode subtle visual differences among different categories, while the shared dictionary encodes common visual patterns among all the categories. To this end, we impose incoherence constraints among the different dictionaries in the objective of feature coding. In addition, to make the learnt dictionary stable, we also impose the constraint that each dictionary should be self-incoherent. Our proposed dictionary learning formulation not only applies to fine-grained classification, but also improves conventional basic-level object categorization and other tasks such as event recognition. Experimental results on five data sets show that our method can outperform the state-of-the-art fine-grained image categorization frameworks as well as sparse coding based dictionary learning frameworks. All these results demonstrate the effectiveness of our method.

  9. An Action-Based Fine-Grained Access Control Mechanism for Structured Documents and Its Application

    Directory of Open Access Journals (Sweden)

    Mang Su

    2014-01-01

    Full Text Available This paper presents an action-based fine-grained access control mechanism for structured documents. Firstly, we define a describing model for structured documents and analyze the application scenarios. The describing model could support the permission management on chapters, pages, sections, words, and pictures of structured documents. Secondly, based on the action-based access control (ABAC model, we propose a fine-grained control protocol for structured documents by introducing temporal state and environmental state. The protocol covering different stages from document creation, to permission specification and usage control are given by using the Z-notation. Finally, we give the implementation of our mechanism and make the comparisons between the existing methods and our mechanism. The result shows that our mechanism could provide the better solution of fine-grained access control for structured documents in complicated networks. Moreover, it is more flexible and practical.

  10. Equivalent dose estimation using a single aliquot of polymineral fine grains

    DEFF Research Database (Denmark)

    Banerjee, D.; Murray, A.S.; Bøtter-Jensen, L.;

    2001-01-01

    We have tested the suitability of a new single-aliquot regenerative-dose protocol for estimating the equivalent dose (D-e) in polymineral fine grains extracted from colluvia from various sites in Germany. First, we report the behaviour of three OSL signals: (i) blue-stimulated, (ii) infrared......C, the post-IR blue signals are stable. The preheat dependence of estimates of D-e obtained using fine grains is presented for the first time, for both blue- and IR-derived signals. Our results are compared with D-e estimates derived from multiple-aliquot additive-dose IR luminescence data, obtained using...

  11. Application of fine-grained coke breeze fractions in the process of iron ore sintering

    Directory of Open Access Journals (Sweden)

    M. Niesler

    2014-01-01

    Full Text Available The testing cycle, described in the paper, included fine-grained coke breeze granulation tests and iron concentrate sintering tests with the use of selected granulate samples. The use of granulated coke breeze in the sintering process results in a higher process efficiency, shorter sintering duration and fuel saving.

  12. The fine-grained phase-space structure of cold dark matter haloes

    NARCIS (Netherlands)

    Vogelsberger, Mark; White, Simon D. M.; Helmi, Amina; Springel, Volker

    2008-01-01

    We present a new and completely general technique for calculating the fine-grained phase-pace structure of dark matter (DM) throughout the Galactic halo. Our goal is to understand this structure on the scales relevant for direct and indirect detection experiments. Our method is based on evaluating t

  13. 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 r...

  14. Some rockmagnetic parameters for natural goethite, pyrrhotite and fine-grained hematite

    NARCIS (Netherlands)

    Dekkers, M.J.

    2012-01-01

    The increasing importance of sediments for paleomagnetic research prompted a study of rockmagnetic parameters of natural goethite, pyrrhotite and hematite. Grain-size dependent behaviour of such parameters is poorly known for goethite and pyrrhotite as well as for fine-grained hematite. Data of

  15. Some rockmagnetic parameters for natural goethite, pyrrhotite and fine-grained hematite

    NARCIS (Netherlands)

    Dekkers, M.J.

    1988-01-01

    The increasing importance of sediments for paleomagnetic research prompted a study of rockmagnetic parameters of natural goethite, pyrrhotite and hematite. Grain-size dependent behaviour of such parameters is poorly known for goethite and pyrrhotite as well as for fine-grained hematite. Data of

  16. Fine-Grained Energy Modeling for the Source Code of a Mobile Application

    DEFF Research Database (Denmark)

    Li, Xueliang; Gallagher, John Patrick

    2016-01-01

    The goal of an energy model for source code is to lay a foundation for the application of energy-aware programming techniques. State of the art solutions are based on source-line energy information. In this paper, we present an approach to constructing a fine-grained energy model which is able...

  17. Spatio-Temporal Detection of Fine-Grained Dyadic Human Interactions

    NARCIS (Netherlands)

    van Gemeren, C.J.; Poppe, R.W.; Veltkamp, R.C.

    2016-01-01

    We introduce a novel spatio-temporal deformable part model for offline detection of fine-grained interactions in video. One novelty of the model is that part detectors model the interacting individuals in a single graph that can contain different combinations of feature descriptors. This allows us t

  18. Spatio-Temporal Detection of Fine-Grained Dyadic Human Interactions

    NARCIS (Netherlands)

    van Gemeren, C.J.; Poppe, R.W.; Veltkamp, R.C.

    2016-01-01

    We introduce a novel spatio-temporal deformable part model for offline detection of fine-grained interactions in video. One novelty of the model is that part detectors model the interacting individuals in a single graph that can contain different combinations of feature descriptors. This allows us

  19. Analytical and Experimental Issues in Ni-Mn-Ga Transducers

    Science.gov (United States)

    2003-01-01

    tests seen in Figure 10 can cause test repeatability problems due to heat issues in the sample, transducer, and amplifiers. However, with adequate...layered martensitic phase,” Appl. Phys. Let. 80, pp. 1746–1749, March 2002. 5. V. Pecharsky and J. K.A. Gshneidner, “Giant magnetocaloric effect in...giant magnetocaloric effect for magnetic refrigeration from 20 to 290 k,” Applied Physics Letters 70, pp. 3299–3301, June 1997. 7. A. Malla, M

  20. Thermal Arrest Memory Effect in Ni-Mn-Ga Alloys

    Directory of Open Access Journals (Sweden)

    A. Rudajevova

    2008-01-01

    Full Text Available Dilatation characteristics were measured to investigate the thermal arrest memory effect in Ni53.6Mn27.1Ga19.3 and Ni54.2Mn29.4Ga16.4 alloys. Interruption of the martensite-austenite phase transformation is connected with the reduction of the sample length after thermal cycle. If a total phase transformation took place in the complete thermal cycle following the interruption, then the sample length would return to its original length. Analysis of these results has shown that the thermal arrest memory effect is a consequence of a stress-focusing effect and shape memory effect. The stress-focusing effect occurs when the phase transformation propagates radially in a cylindrical sample from the surface, inward to the center. Evolution and release of the thermoelastic deformations in both alloys during heating and cooling are analyzed.

  1. A Deployment of Fine-Grained Sensor Network and Empirical Analysis of Urban Temperature

    Directory of Open Access Journals (Sweden)

    Yoshito Tobe

    2010-03-01

    Full Text Available Temperature in an urban area exhibits a complicated pattern due to complexity of infrastructure. Despite geographical proximity, structures of a group of buildings and streets affect changes in temperature. To investigate the pattern of fine-grained distribution of temperature, we installed a densely distributed sensor network called UScan. In this paper, we describe the system architecture of UScan as well as experience learned from installing 200 sensors in downtown Tokyo. The field experiment of UScan system operated for two months to collect long-term urban temperature data. To analyze the collected data in an efficient manner, we propose a lightweight clustering methodology to study the correlation between the pattern of temperature and various environmental factors including the amount of sunshine, the width of streets, and the existence of trees. The analysis reveals meaningful results and asserts the necessity of fine-grained deployment of sensors in an urban area.

  2. A deployment of fine-grained sensor network and empirical analysis of urban temperature.

    Science.gov (United States)

    Thepvilojanapong, Niwat; Ono, Takahiro; Tobe, Yoshito

    2010-01-01

    Temperature in an urban area exhibits a complicated pattern due to complexity of infrastructure. Despite geographical proximity, structures of a group of buildings and streets affect changes in temperature. To investigate the pattern of fine-grained distribution of temperature, we installed a densely distributed sensor network called UScan. In this paper, we describe the system architecture of UScan as well as experience learned from installing 200 sensors in downtown Tokyo. The field experiment of UScan system operated for two months to collect long-term urban temperature data. To analyze the collected data in an efficient manner, we propose a lightweight clustering methodology to study the correlation between the pattern of temperature and various environmental factors including the amount of sunshine, the width of streets, and the existence of trees. The analysis reveals meaningful results and asserts the necessity of fine-grained deployment of sensors in an urban area.

  3. The exceptional sediment load of fine-grained dispersal systems: Example of the Yellow River, China.

    Science.gov (United States)

    Ma, Hongbo; Nittrouer, Jeffrey A; Naito, Kensuke; Fu, Xudong; Zhang, Yuanfeng; Moodie, Andrew J; Wang, Yuanjian; Wu, Baosheng; Parker, Gary

    2017-05-01

    Sedimentary dispersal systems with fine-grained beds are common, yet the physics of sediment movement within them remains poorly constrained. We analyze sediment transport data for the best-documented, fine-grained river worldwide, the Huanghe (Yellow River) of China, where sediment flux is underpredicted by an order of magnitude according to well-accepted sediment transport relations. Our theoretical framework, bolstered by field observations, demonstrates that the Huanghe tends toward upper-stage plane bed, yielding minimal form drag, thus markedly enhancing sediment transport efficiency. We present a sediment transport formulation applicable to all river systems with silt to coarse-sand beds. This formulation demonstrates a remarkably sensitive dependence on grain size within a certain narrow range and therefore has special relevance to silt-sand fluvial systems, particularly those affected by dams.

  4. UTLEON3 Exploring Fine-Grain Multi-Threading in FPGAs

    CERN Document Server

    Daněk, Martin; Kohout, Lukáš; Sýkora, Jaroslav; Bartosinski, Roman

    2013-01-01

    This book describes a specification, microarchitecture, VHDL implementation and evaluation of a SPARC v8 CPU with fine-grain multi-threading, called micro-threading. The CPU, named UTLEON3, is an alternative platform for exploring CPU multi-threading that is compatible with the industry-standard GRLIB package. The processor microarchitecture was designed to map in an efficient way the data-flow scheme on a classical von Neumann pipelined processing used in common processors, while retaining full binary compatibility with existing legacy programs.  Describes and documents a working SPARC v8, with fine-grain multithreading and fast context switch; Provides VHDL sources for the described processor; Describes a latency-tolerant framework for coupling hardware accelerators to microthreaded processor pipelines; Includes programming by example in the micro-threaded assembly language.    

  5. 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...

  6. Synthesis of Dense, Fine-Grained YIG Ceramics by Two-Step Sintering

    Science.gov (United States)

    Li, X. X.; Zhou, J. J.; Deng, J. X.; Zheng, H.; Zheng, L.; Zheng, P.; Qin, H. B.

    2016-10-01

    A two-step sintering (TSS) process has been used to fabricate yttrium iron garnet (YIG) ceramics with high density and fine grain size. The densification, microstructure, and magnetic properties were investigated. The sample prepared by the TSS process with first-step sintering temperature ( T 1) of 1350°C, second-step sintering temperature ( T 2) of 1300°C, and holding time of 18 h had density above 99% of theoretical and exhibited uniform microstructure with small average grain size (2.4 μm). The saturation magnetization ( M S) of this sample reached 27.4 emu/g. These results indicate that the TSS process can effectively suppress grain-boundary migration while maintaining active grain-boundary diffusion to obtain dense, fine-grained YIG ceramics with appropriate magnetic properties.

  7. Fine-grained pitch processing of music and speech in congenital amusia.

    Science.gov (United States)

    Tillmann, Barbara; Rusconi, Elena; Traube, Caroline; Butterworth, Brian; Umiltà, Carlo; Peretz, Isabelle

    2011-12-01

    Congenital amusia is a lifelong disorder of music processing that has been ascribed to impaired pitch perception and memory. The present study tested a large group of amusics (n=17) and provided evidence that their pitch deficit affects pitch processing in speech to a lesser extent: Fine-grained pitch discrimination was better in spoken syllables than in acoustically matched tones. Unlike amusics, control participants performed fine-grained pitch discrimination better for musical material than for verbal material. These findings suggest that pitch extraction can be influenced by the nature of the material (music vs speech), and that amusics' pitch deficit is not restricted to musical material, but extends to segmented speech events. © 2011 Acoustical Society of America

  8. Electric dewatering and drying of fine-grained products; Elektrisk afvanding og toerring af finkornede produkter

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, H.K.; Villumsen, A.

    2001-07-01

    The aim of the project was to elucidate four aspects related to using electric direct current to find an energy saving alternative to existing methods within dewatering of fine-grained products. The four aspects were a) electrophoresis forced sedimentation of chalk slurry, b) electro osmotic dewatering of chalk slurry, c) electro osmotic dewatering of agricultural chalk and d) electro osmotic dewatering of liquid organic wastes. (EHS)

  9. Microstructure Characterization and Imaging of Fine-Grained Steel by Microscopic Ultrasonic Techniques

    Science.gov (United States)

    Hirsekorn, S.; Rabe, U.; Batista, L.; Behl, L.

    2011-06-01

    An important task in materials science is the design of new steel grades with tailored microstructures for powerful mechanical properties aiming at a common optimization of contradicting properties such as weight reduction and formability versus high stiffness and strength. For this purpose techniques are required to image and characterize microstructures and probe local material properties in the micro- and nanoscale. This contribution reports on investigations of fine-grained steels by scanning acoustic microscopy (SAM) and atomic force acoustic microscopy (AFAM).

  10. FINE-GRAINED DISTRIBUTED MULTIMEDIA SYNCHRONIZA- TION MODEL--ENHANCED FUZZY-TIMING PETRI NET

    Institute of Scientific and Technical Information of China (English)

    韩莹洁; 孙永强; 吴哲辉

    2001-01-01

    A fine-grained distributed multimedia synchronization model--Enhanced Fuzzy timing Petri Net was proposed which is good at modeling indeterminacy and fuzzy. To satisfy the need of maximum tolerable jitter, the sufficient conditions are given in intra-object synchronization. Method to find a proper granularity in inter-object synchronization is also given to satisfy skew. Exceptions are detected and corrected as early as possible using restricted blocking method.

  11. Using Heterogeneous High Performance Computing Cluster for Supporting Fine-Grained Parallel Applications

    Science.gov (United States)

    2006-10-01

    Beowulf cluster made of COTS PCs (featuring dual processor Xeon’s) interconnected via a Gigabit Ethernet Network and a Myrinet network [Boden 1995...AFRL-IF-RS-TR-2006-313 Final Technical Report October 2006 USING HETEROGENEOUS HIGH PERFORMANCE COMPUTING CLUSTER FOR SUPPORTING...GRANT NUMBER FA8750-05-1-0130 4. TITLE AND SUBTITLE USING HETEROGENEOUS HIGH PERFORMANCE COMPUTING CLUSTER FOR SUPPORTING FINE-GRAINED PARALLEL

  12. An Improved Weighting Algorithm to Achieve Software Compensation in a Fine Grained LAr Calorimeter

    OpenAIRE

    Issever, C.; Borras, K.; Wegener, D.

    2004-01-01

    An improved weighting algorithm applied to hadron showers has been developed for a fine grained LAr calorimeter. The new method uses tabulated weights which depend on the density of energy deposited in individual cells and in a surrounding cone whose symmetry axis connects the interaction vertex with the highest energy cluster in the shower induced by a hadron. The weighting of the visible energy and the correction for losses due to noise cuts are applied in separate steps. In contrast to sta...

  13. Inference of Fine-grained Attributes of Bengali Corpus for Stylometry Detection

    OpenAIRE

    Chakraborty, Tanmoy; Bandyopadhyay, Sivaji

    2012-01-01

    Stylometry, the science of inferring characteristics of the author from the characteristics of documents written by that author, is a problem with a long history and belongs to the core task of Text categorization that involves authorship identification, plagiarism detection, forensic investigation, computer security, copyright and estate disputes etc. In this work, we present a strategy for stylometry detection of documents written in Bengali. We adopt a set of fine-grained attribute feature...

  14. Structure and properties of advanced fine grained steels produced using novel thermal treatments

    OpenAIRE

    Vuorinen, Esa

    2012-01-01

    Fine grained advanced steels exhibit favourable mechanical properties for applications requiring high strength, ductility and impact toughness. These properties result from a microstructure containing a fine distribution of several phases including ferrite, austenite, martensite and bainite. The bainite phase is in the form of fine lamellas of ferrite and carbon-enriched austenite which due to proper control of the chemical composition is lacking the nanometre scaled carbides associated with ...

  15. Fine-grained variation in caregivers' /s/ predicts their infants' /s/ category.

    Science.gov (United States)

    Cristià, Alejandrina

    2011-05-01

    Within the debate on the mechanisms underlying infants' perceptual acquisition, one hypothesis proposes that infants' perception is directly affected by the acoustic implementation of sound categories in the speech they hear. In consonance with this view, the present study shows that individual variation in fine-grained, subphonemic aspects of the acoustic realization of /s/ in caregivers' speech predicts infants' discrimination of this sound from the highly similar /∫/, suggesting that learning based on acoustic cue distributions may indeed drive natural phonological acquisition.

  16. Microstructure and mechanical properties of fine grain seamless Nb tube by a novel shear deformation process

    Science.gov (United States)

    Balachandran, S.; Seymour, N.; Mezyenski, R.; Barber, R.; Hartwig, K. T.

    2014-01-01

    The objective of this work is to demonstrate a seamless tube fabrication method for obtaining uniform fine grained microstructures by a novel shear deformation process for tubular metal products. The manufacture of fine grained RRR Nb superconducting radio frequency (SRF) cavities, and other tubular Nb products requires strict microstructure control with respect to grain size and texture for good formability. The major challenges in SRF cavity fabrication and performance stems from: a) the high cost of pure Nb, b) a poor and inconsistent microstructure in the starting material, and c) seam welding to manufacture multi-cell cavities. The approach presented by the authors indicates a possible strategy to obtain fine grain Nb tube by an innovative shear process. Grain size less than 30μm and tensile ductility greater than 40 percent in the orthogonal direction are achieved. The tensile properties correlate with the strongest texture component in the processed tube. Based on preliminary results, the proposed methodology maybe a viable and cost effective approach to fabricating a seamless Nb tube with good hydroformability.

  17. Detecting Densely Distributed Graph Patterns for Fine-Grained Image Categorization.

    Science.gov (United States)

    Zhang, Luming; Yang, Yang; Wang, Meng; Hong, Richang; Nie, Liqiang; Li, Xuelong

    2016-02-01

    Fine-grained image categorization is a challenging task aiming at distinguishing objects belonging to the same basic-level category, e.g., leaf or mushroom. It is a useful technique that can be applied for species recognition, face verification, and so on. Most of the existing methods either have difficulties to detect discriminative object components automatically, or suffer from the limited amount of training data in each sub-category. To solve these problems, this paper proposes a new fine-grained image categorization model. The key is a dense graph mining algorithm that hierarchically localizes discriminative object parts in each image. More specifically, to mimic the human hierarchical perception mechanism, a superpixel pyramid is generated for each image. Thereby, graphlets from each layer are constructed to seamlessly capture object components. Intuitively, graphlets representative to each super-/sub-category is densely distributed in their feature space. Thus, a dense graph mining algorithm is developed to discover graphlets representative to each super-/sub-category. Finally, the discovered graphlets from pairwise images are integrated into an image kernel for fine-grained recognition. Theoretically, the learned kernel can generalize several state-of-the-art image kernels. Experiments on nine image sets demonstrate the advantage of our method. Moreover, the discovered graphlets from each sub-category accurately capture those tiny discriminative object components, e.g., bird claws, heads, and bodies.

  18. Fine grain IRSL and GLSL dating of late Quaternary sediments from North China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A possible approach to assess the fine grain OSL dating isdiscussed through comparison of equivalent dose (DE) values and ages obtained by IRSL and GLSL of fine grains for 31 sediment samples from North China. The IRSL and GLSL were measured with the same aliquots for each sample, i.e. shine-down was by 100 s of IRSL (880 nm) followed by 100 s of GLSL (514 nm) on the same discs. The DE values and ages found by IRSL are in good agreement with those by GLSL within 1-2σfor 80% samples, especially for aeolian loess samples. Considering that IRSL from feldspar differs obviously from GLSL dominated from quartz in dose response, thermal stability and optical bleaching characteristic, the agreement between the DE values may be taken as evidence that the two clocks of IRSL and GLSL had been well reset during deposition. The consistent ages of IRSL and GLSL, in turn, may be referred to an indicator to evaluate the fine grain OSL dating of sediments.

  19. Investigation on fracture behavior of the welded joint HAZ of ultra-fine grain steel SS400

    Institute of Scientific and Technical Information of China (English)

    朱政强; 陈立功; 荆洪阳; 葛景国; 倪纯珍; 饶德林

    2003-01-01

    The critical crack dimensions of both base-metal specimen and HAZ specimen are measured via wide-plate tensile tests. Based on the "fitness for purpose" principle, the fracture behavior of the ultra-fine grain steel SS400 welded joint HAZ is assessed. The test results indicate that overmatching is benefit for the whole capability's improvement of ultra-fine grain steel SS400. The test results are confirmed by using finite element method (FEM).

  20. Characterizing shear properties of fine-grained subgrade soils under large capacity construction equipment

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2010-06-01

    Full Text Available of Normally Consolidated Clay.” Journal of Soil Mechanics and Foundation Engineering Division, ASCE, 94 (SM2), 353- 369. Hardin, B.O., and Drnevich, V.P. (1972). “Shear Modulus and Damping in Soils: Design Equation and Curves.” Journal of Soil Mechanics... for their sustainable use in construction applications. INTRODUCTION Cohesive fine-grained and cohesionless granular soils all referred to here as geomaterials constitute the foundation of highway and airport pavements as well as railroad track...

  1. Enhanced ionic transport in fine-grained scandia-stabilized zirconia ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Abdala, Paula M.; Lamas, Diego G. [CINSO (Centro de Investigaciones en Solidos), CONICET-CITEFA, J.B. de La Salle 4397 (B1603ALO) Villa Martelli, Pcia. de Buenos Aires (Argentina); Custo, Graciela S. [Gerencia de Area Seguridad Nuclear y Ambiente, Gerencia Quimica, Departamento Quimica Analitica, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Av. Constituyentes 1499 (B1650KNA) San Martin, Pcia. de Buenos Aires (Argentina)

    2010-06-01

    In this work, the transport properties of fine-grained scandia-stabilized zirconia ceramics with low Si content have been investigated. These materials were prepared from ZrO{sub 2}-6 mol% Sc{sub 2}O{sub 3} nanopowders synthesized by a nitrate-lysine gel-combustion route. High relative densities and excellent electrical properties were obtained, even for sintering temperatures as low as 1350 C. Our electrochemical impedance spectroscopy study showed that both the volume fraction of grain boundaries and the specific grain-boundary conductivity are significantly enhanced with decreasing grain size, resulting in a higher total ionic conductivity. (author)

  2. Evaluation of the Parameters Affecting the Cohesion of Fine Grained Soil

    Science.gov (United States)

    Vondráčková, Terezie; Kmec, Ján; Čejka, Jiří; Bartuška, Ladislav; Stopka, Ondrej

    2016-10-01

    Cohesion of the soils is one of the most important parameters which soil is evaluated in terms of its suitability for building foundations. Safety of construction is in fact dependent on the strength of soil, respectively shear strength. Fine-grained soil represents very specific group, in which is distinguished an effective and total cohesion of soils. The water in the soil thus drastically affects its cohesion contrary to gravel and sandy soils. The publication compares the tabular values of the effective and total cohesion and define the influence of water, grain size and consistency of her behaviour.

  3. Analysis of Grain Boundary Character in a Fine-Grained Nickel-Based Superalloy 718

    Science.gov (United States)

    Araujo, L. S.; dos Santos, D. S.; Godet, S.; Dille, J.; Pinto, A. L.; de Almeida, L. H.

    2014-11-01

    In the current work, sheets of superalloy 718 were processed via thermomechanical route by hot and cold rolling, followed by annealing below the δ phase solvus temperature and precipitation hardening to optimum strength. Grain boundary character distribution throughout the processing was mapped via EBSD and its evolution discussed. The results show that it is possible to process the alloy to a fine grain size obtaining concomitantly a considerably high proportion of special boundaries Σ3, Σ9, and Σ27. The precipitation of δ phase presented a strong grain refining role, without significantly impairing the twinning mechanism and, consequently, the Σ3, Σ9, and Σ27 boundary formations.

  4. Thermal and microstructural properties of fine-grained material at the Viking Lander 1 site

    Science.gov (United States)

    Paton, M. D.; Harri, A.-M.; Savijärvi, H.; Mäkinen, T.; Hagermann, A.; Kemppinen, O.; Johnston, A.

    2016-06-01

    As Viking Lander 1 touched down on Mars one of its footpads fully penetrated a patch of loose fine-grained drift material. The surrounding landing site, as observed by VL-1, was found to exhibit a complex terrain consisting of a crusted surface with an assortment of rocks, large dune-like drifts and smaller patches of drift material. We use a temperature sensor attached to the buried footpad and covered in fine-grained material to determine the thermal properties of drift material at the VL-1 site. The thermal properties are used to investigate the microstructure of the drift material and understand its relevance to surface-atmosphere interactions. We obtained a thermal inertia value of 103 ± 22 tiu. This value is in the upper range of previous thermal inertia estimates of martian dust as measured from orbit and is significantly lower than the regional thermal inertia of the VL-1 site, of around 283 tiu, obtained from orbit. We estimate a thermal inertia of around 263 ± 29 tiu for the duricrust at the VL-1 site. It was noted the patch of fine-grained regolith around the footpad was about 20-30 K warmer compared to similar material beyond the thermal influence of the lander. An effective diameter of 8 ± 5 μm was calculated for the particles in the drift material. This is larger than atmospheric dust and large compared to previous estimates of the drift material particle diameter. We interpret our results as the presence of a range of particle sizes, <8 μm, in the drift material with the thermal properties being controlled by a small amount of large particles (˜8 μm) and its cohesion being controlled by a large amount of smaller particles. The bulk of the particles in the drift material are therefore likely comparable in size to that of atmospheric dust. The possibility of larger particles being locked into a fine-grained material has implications for understanding the mobilisation of wind blown materials on Mars.

  5. Prediction of HAZ grain size in welding of ultra fine grained steel with different parameters

    Institute of Scientific and Technical Information of China (English)

    Zhao Hongyun; Zhang Hongtao; Li Dongqing; Wang Guodong

    2010-01-01

    The temperature field and thermal cycling curve in the heat-affected zone during welding 400 MPa ultra fine grained steel by plasma arc were simulated using finite element method.The principle of grain growth kinetics was used to predict the grain size in the heat-affected zone under different welding parameters.The simulation results show that the growing tendency of HAZ grain could be controlled by adjusting the welding parameters,but the growth of HAZ grain could not be eliminated at all.The HAZ grain size became small with increasing of the cooling rate and added with increasing of welding current,arc voltage and welding speed.

  6. Surface grain coarsening and surface softening during machining of ultra-fine grained titanium

    Directory of Open Access Journals (Sweden)

    Symonova A.A.

    2012-01-01

    Full Text Available Experiments are run to show that different machining conditions applied to ultra-fine grained pure titanium lead to different levels of grain coarsening and softening near the machined surface. Under “hard” machining conditions the upper 40 microns of the machined surface are altered with a decreased microhardness. The experimental results are reasonably reproduced by model calculations. Expanding the parameter field of the model calculations, the surface coarsening diagram and the surface softening diagram due to machining are presented, showing the region of technological parameters, under which neither grain coarsening nor softening takes place along the machined surface.

  7. Webly-supervised Fine-grained Visual Categorization via Deep Domain Adaptation.

    Science.gov (United States)

    Xu, Zhe; Huang, Shaoli; Zhang, Ya; Tao, Dacheng

    2016-12-08

    Learning visual representations from web data has recently attracted attention for object recognition. Previous studies have mainly focused on overcoming label noise and data bias and have shown promising results by learning directly from web data. However, we argue that it might be better to transfer knowledge from existing human labeling resources to improve performance at nearly no additional cost. In this paper, we propose a new semi-supervised method for learning via web data. Our method has the unique design of exploiting strong supervision, i.e., in addition to standard image-level labels, our method also utilizes detailed annotations including object bounding boxes and part landmarks. By transferring as much knowledge as possible from existing strongly supervised datasets to weakly supervised web images, our method can benefit from sophisticated object recognition algorithms and overcome several typical problems found in webly-supervised learning. We consider the problem of fine-grained visual categorization, in which existing training resources are scarce, as our main research objective. Comprehensive experimentation and extensive analysis demonstrate encouraging performance of the proposed approach, which, at the same time, delivers a new pipeline for fine-grained visual categorization that is likely to be highly effective for real-world applications.

  8. OSL dating of fine-grained quartz from Holocene Yangtze delta sediments

    DEFF Research Database (Denmark)

    Sugisaki, Saiko; Buylaert, Jan-Pieter; Murray, Andrew;

    2015-01-01

    sediment cores (YD13-G3 and H1) were taken from the Yangtze subaqueous delta to investigate precipitation history. In this study, we investigate the potential of quartz OSL dating of the fine silt fraction (fine-grained quartz; 4-11 μm) from these cores to estimate the depositional age of the sediments. We...... test whether: (1) Yangtze subaqueous delta sediments contain quartz with suitable characteristics for dating, and (2) quartz grains are well-bleached during/before the transportation process, by examining a modern analogue of suspended particulate matter, and by cross-checking with the doses derived...... from infrared stimulated luminescence (IRSL) signals (both IR50 and pIRIR160) from feldspar in polymineral fine grains. We find that both the quartz and feldspar luminescence characteristics are satisfactory (quartz dose recovery ratio 1.067 ± 0.004; n = 250, pIRIR160 dose recovery ratio 1.01 ± 0.02; n...

  9. Source identification of fine-grained suspended sediment in the Kharaa River basin, northern Mongolia.

    Science.gov (United States)

    Theuring, Philipp; Collins, Adrian L; Rode, Michael

    2015-09-01

    Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (0.97) and were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin), generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of river bank erosion is shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the applicability and associated uncertainties of the approach for fine-grained sediment source investigation in large scale semi-arid catchments. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Fine Grained Sentiment Classification of Customer Reviews Using Computational Intelligent Technique

    Directory of Open Access Journals (Sweden)

    C Priyanka

    2015-08-01

    Full Text Available Online reviews are now popularly used for judging quality of product or service and influence decision making of users while selecting a product or service. Due to innumerous number of customer reviews on the web, it is difficult to summarize them which require a faster opinion mining system to classify the reviews. Many researchers have explored various supervised and unsupervised machine learning techniques for binary classification of reviews. Compared to these techniques, fuzzy logic can provide a straightforward and comparatively faster way to model the fuzziness existing between the sentiment polarities classes due to the ambiguity present in most of the natural languages. But the fuzzy logic techniques are less explored in this domain. Hence in this paper, a fuzzy logic model based on the most popularly known sentiment based lexicon SentiWordNet has been proposed for fine grained classification of the reviews into weak positive, moderate positive, strong positive, weak negative, moderate negative and strong negative classes. Experiments have been conducted on datasets containing reviews of electronic products namely smart phones, LED TV and laptops and have shown to provide fine grained classification accuracy approximately in the range of 74% to 77%.

  11. Fabrication of fine-grain tantalum diffusion barrier tube for Nb{sub 3}Sn conductors

    Energy Technology Data Exchange (ETDEWEB)

    Hartwig, K. T.; Balachandran, S.; Mezyenski, R.; Seymour, N. [Department of Mechanical Engineering, Texas A and M University, TX 77843 (United States); Robinson, J.; Barber, R. E. [Shear Form Inc, 207 Dellwood St, Bryan 77801 (United States)

    2014-01-27

    Diffusion barriers used in Nb{sub 3}Sn wire are often fabricated by wrapping Ta sheet into a tube with an overlap seam. A common result of such practice is non-uniform deformation in the Ta sheet as it thins by wire drawing because of non-uniform grain size and texture in the original Ta sheet. Seamless Ta tube with a fine-grain and uniform microstructure would be much better for the diffusion barrier application, but such material is expensive and difficult to manufacture. This report presents results on a new fabrication strategy for Ta tube that shows promise for manufacture of less costly tube with an improved microstructure. The fabrication method begins with seam-welded tube but gives a fine-grain uniform microstructure with little difference between the longitudinal seam weld region and the parent metal after post-weld processing. Severe plastic deformation processing (SPD) applied by area reduction extrusion and tube equal channel angular extrusion (tECAE) are used to refine and homogenize the microstructure. Microstructure and mechanical property results are presented for Ta tubes fabricated by this new processing strategy.

  12. Fabrication of fine-grain tantalum diffusion barrier tube for Nb3Sn conductors

    Science.gov (United States)

    Hartwig, K. T.; Balachandran, S.; Mezyenski, R.; Seymour, N.; Robinson, J.; Barber, R. E.

    2014-01-01

    Diffusion barriers used in Nb3Sn wire are often fabricated by wrapping Ta sheet into a tube with an overlap seam. A common result of such practice is non-uniform deformation in the Ta sheet as it thins by wire drawing because of non-uniform grain size and texture in the original Ta sheet. Seamless Ta tube with a fine-grain and uniform microstructure would be much better for the diffusion barrier application, but such material is expensive and difficult to manufacture. This report presents results on a new fabrication strategy for Ta tube that shows promise for manufacture of less costly tube with an improved microstructure. The fabrication method begins with seam-welded tube but gives a fine-grain uniform microstructure with little difference between the longitudinal seam weld region and the parent metal after post-weld processing. Severe plastic deformation processing (SPD) applied by area reduction extrusion and tube equal channel angular extrusion (tECAE) are used to refine and homogenize the microstructure. Microstructure and mechanical property results are presented for Ta tubes fabricated by this new processing strategy.

  13. A Hybrid Scheme for Fine-Grained Search and Access Authorization in Fog Computing Environment

    Science.gov (United States)

    Xiao, Min; Zhou, Jing; Liu, Xuejiao; Jiang, Mingda

    2017-01-01

    In the fog computing environment, the encrypted sensitive data may be transferred to multiple fog nodes on the edge of a network for low latency; thus, fog nodes need to implement a search over encrypted data as a cloud server. Since the fog nodes tend to provide service for IoT applications often running on resource-constrained end devices, it is necessary to design lightweight solutions. At present, there is little research on this issue. In this paper, we propose a fine-grained owner-forced data search and access authorization scheme spanning user-fog-cloud for resource constrained end users. Compared to existing schemes only supporting either index encryption with search ability or data encryption with fine-grained access control ability, the proposed hybrid scheme supports both abilities simultaneously, and index ciphertext and data ciphertext are constructed based on a single ciphertext-policy attribute based encryption (CP-ABE) primitive and share the same key pair, thus the data access efficiency is significantly improved and the cost of key management is greatly reduced. Moreover, in the proposed scheme, the resource constrained end devices are allowed to rapidly assemble ciphertexts online and securely outsource most of decryption task to fog nodes, and mediated encryption mechanism is also adopted to achieve instantaneous user revocation instead of re-encrypting ciphertexts with many copies in many fog nodes. The security and the performance analysis show that our scheme is suitable for a fog computing environment. PMID:28629131

  14. Nearshore disposal of fine-grained sediment in a high-energy environment: Santa Cruz Harbor case study

    Science.gov (United States)

    Cronin, Katherine; van Ormondt, Maarten; Storlazzi, Curt D.; Presto, Katherine; Tonnon, Pieter K.; Rosati, Julie D.; Wang, Ping; Roberts, Tiffany M.

    2011-01-01

    Current regulations in California prohibit the disposal of more than 20% fine-grained sediment in the coastal zone; this threshold is currently being investigated to determine if this environmental regulation can be improved upon. A field monitoring and numerical modeling experiment took place late 2 009 to determine the fate of fine-grained dredge disposal material from Santa Cruz Harbor, California, U.S.A. A multi-nested, hydrodynamic-sediment transport modeling approach was used to simulate the direction and dispersal of the dredge plume. Result s show that the direction and dispersal of the plume was influenced by the wave  climate, a large proportion of which moved in a easterly direction during wave events. Therefore it is vitally important to accurately simulate the tides, waves, currents, temperature and salinity when modeling the dispersal of the fine-grained dredge plume. 

  15. Fine Grained Silicon-Tungsten Calorimetry for a Linear Collider Detector

    Energy Technology Data Exchange (ETDEWEB)

    Strom, D.; Frey, R.; /Oregon U.; Breidenbach, M.; Freytag, D.; Graf, N.; Haller, G.; Milgrome, O.; /SLAC; Radeka, V.; /Brookhaven

    2006-02-08

    A fine grained silicon-tungsten calorimeter is ideal for use as the electromagnetic calorimeter in a linear collider detector optimized for particle-flow reconstruction. We are designing a calorimeter that is based on readout chips which are bump bonded to the silicon wafers that serve as the active medium in the calorimeter. By using integrated electronics we plan to demonstrate that fine granularity can be achieved at a reasonable price. Our design minimizes the gap between tungsten layers leading to a small Moliere radius, an important figure of merit for particle-flow detectors. Tests of the silicon detectors to be used in a test beam prototype as well as timing measurements based on similar silicon detectors are discussed.

  16. Fine grained event processing on HPCs with the ATLAS Yoda system

    CERN Document Server

    Calafiura, Paolo; The ATLAS collaboration; Guan, Wen; Maeno, Tadashi; Nilsson, Paul; Oleynik, Danila; Panitkin, Sergey; Tsulaia, Vakhtang; van Gemmeren, Peter; Wenaus, Torre

    2015-01-01

    High performance computing facilities present unique challenges and opportunities for HENP event processing. The massive scale of many HPC systems means that fractionally small utilizations can yield large returns in processing throughput. Parallel applications which can dynamically and efficiently fill any scheduling opportunities the resource presents benefit both the facility (maximal utilization) and the (compute-limited) science. The ATLAS Yoda system provides this capability to HENP-like event processing applications by implementing event-level processing in an MPI-based master-client model that integrates seamlessly with the more broadly scoped ATLAS Event Service. Fine grained, event level work assignments are intelligently dispatched to parallel workers to sustain full utilization on all cores, with outputs streamed off to destination object stores in near real time with similarly fine granularity, such that processing can proceed until termination with full utilization. The system offers the efficie...

  17. mizar-items: Exploring fine-grained dependencies in the Mizar Mathematical Library

    CERN Document Server

    Alama, Jesse

    2011-01-01

    The Mizar Mathematical Library (MML) is a rich database of formalized mathematical proofs (see http://mizar.org). Owing to its large size (it contains more than 1100 "articles" summing to nearly 2.5 million lines of text, expressing more than 50000 theorems and 10000 definitions using more than 7000 symbols), the nature of its contents (the MML is slanted toward pure mathematics), and its classical foundations (first-order logic, set theory, natural deduction), the MML is an especially attractive target for research on foundations of mathematics. We have implemented a system, mizar-items, on which a variety of such foundational experiements can be based. The heart of mizar-items is a method for decomposing the contents of the MML into fine-grained "items" (e.g., theorem, definition, notation, etc.) and computing dependency relations among these items. mizar-items also comes equipped with a website for exploring these dependencies and interacting with them.

  18. Memory for pitch in congenital amusia: beyond a fine-grained pitch discrimination problem.

    Science.gov (United States)

    Williamson, Victoria Jane; Stewart, Lauren

    2010-08-01

    Congenital amusia is a disorder that affects the perception and production of music. While amusia has been associated with deficits in pitch discrimination, several reports suggest that memory deficits also play a role. The present study investigated short-term memory span for pitch-based and verbal information in 14 individuals with amusia and matched controls. Analogous adaptive-tracking procedures were used to generate tone and digit spans using stimuli that exceeded psychophysically measured pitch perception thresholds. Individuals with amusia had significantly smaller tone spans, whereas their digits spans were a similar size to those of controls. An automated operation span task was used to determine working memory capacity. Working memory deficits were seen in only a small subgroup of individuals with amusia. These findings support the existence of a pitch-specific component within short-term memory and suggest that congenital amusia is more than a disorder of fine-grained pitch discrimination.

  19. Synthesis and Mechanical Characterisation of an Ultra-Fine Grained Ti-Mg Composite

    Directory of Open Access Journals (Sweden)

    Markus Alfreider

    2016-08-01

    Full Text Available The importance of lightweight materials such as titanium and magnesium in various technical applications, for example aerospace, medical implants and lightweight construction is well appreciated. The present study is an attempt to combine and improve the mechanical properties of these two materials by forming an ultra-fine grained composite. The material, with a composition of 75 vol% (88.4 wt% Ti and 25 vol% (11.4 wt% Mg , was synthesized by powder compression and subsequently deformed by high-pressure torsion. Using focused ion beam machining, miniaturised compression samples were prepared and tested in-situ in a scanning electron microscope to gain insights into local deformation behaviour and mechanical properties of the nanocomposite. Results show outstanding yield strength of around 1250 MPa, which is roughly 200 to 500 MPa higher than literature reports of similar materials. The failure mode of the samples is accounted for by cracking along the phase boundaries.

  20. Experimental research on the behavior of the pneumatic transport of fine-grained iron

    Science.gov (United States)

    Andrei, V.; Hritac, M.; Constantin, N.; Dobrescu, C.

    2017-01-01

    Mixed injection of fine-grained iron ore and pulverized coal in the furnace, involves determining the behavior of these materials during pneumatic transport in a dense state through the pipe and setting possibilities for adjusting the flow rate of material transported with the corresponding values of the process. Parameters of the pneumatic transport were determined for the main types of iron ore and chalk used in Arcelor Mittal Galati. Outside the intended purpose of injecting iron ore and flux, it was considered also the experimental check of the possibility for injecting ilmenite in the furnace for crucible protection purpose. The possibility of injecting cinder mill into the furnace was also considered. Injecting cinder could be taken into account for the recycling of ferrous waste in the furnace, also as additive for intensifying the combustion process around the tuyeres.

  1. Fine-grained permutation entropy as a measure of natural complexity for time series

    Institute of Scientific and Technical Information of China (English)

    Liu Xiao-Feng; Wang Yue

    2009-01-01

    In a recent paper [2002 Phys. Rev. Lett. 88 174102], Bandt and Pompe propose permutation entropy (PE)as a natural complexity measure for arbitrary time series which may be stationary or nonstationary, deterministic or stochastic. Their method is based on a comparison of neighbouring values. This paper further develops PE, and proposes the concept of fine-grained PE (FGPE) defined by the order pattern and magnitude of the difference between neighbouring values. This measure excludes the case where vectors with a distinct appearance are mistakenly mapped onto the same permutation type, and consequently FGPE becomes more sensitive to the dynamical change of time series than does PE, according to our simulation and experimental results.

  2. Fatigue Strength Improvement of Welded Joint by Ultrasonic Peening in Ultra-Fine Grain Steel

    Institute of Scientific and Technical Information of China (English)

    TIAN Zhi-ling; ZOU Gang; HE Chang-hong; ZHANG Xiao-mu

    2003-01-01

    The ultrasonic peening of weld toes in ultra-fine grain steel was applied to enhance the fatigue behavior. The test results show that the ultrasonic treatment remarkably shifts the S-N curve to the right. The FAT (fatigue strength at 106 cycles) is increased by 66 %. The fatigue life at Δσ=200 MPa is extended by 58 times. The mechanism of fatigue strength improvement by ultrasonic treatment was studied. It is shown that two mechanisms improve the fatigue strength of welded joint by ultrasonic treatment: one is the decrease of the stress concentration ratio at weld toes, and the other is the building-up of a compressive residual stress at the weld.

  3. High Temperature Flow Response Modeling of Ultra-Fine Grained Titanium

    Directory of Open Access Journals (Sweden)

    Seyed Vahid Sajadifar

    2015-07-01

    Full Text Available This work presents the mechanical behavior modeling of commercial purity titanium subjected to severe plastic deformation (SPD during post-SPD compression, at temperatures of 600-900 °C and at strain rates of 0.001-0.1 s−1. The flow response of the ultra-fine grained microstructure is modeled using the modified Johnson-Cook model as a predictive tool, aiding high temperature forming applications. It was seen that the model was satisfactory at all deformation conditions except for the deformation temperature of 600 °C. In order to improve the predictive capability, the model was extended with a corrective term for predictions at temperatures below 700 °C. The accuracy of the model was displayed with reasonable agreement, resulting in error levels of less than 5% at all deformation temperatures.

  4. Fine grained event processing on HPCs with the ATLAS Yoda system

    CERN Document Server

    Calafiura, Paolo; The ATLAS collaboration; Guan, Wen; Maeno, Tadashi; Nilsson, Paul; Oleynik, Danila; Panitkin, Sergey; Tsulaia, Vakhtang; van Gemmeren, Peter; Wenaus, Torre

    2015-01-01

    High performance computing facilities present unique challenges and opportunities for HENP event processing. The massive scale of many HPC systems means that fractionally small utilizations can yield large returns in processing throughput. Parallel applications which can dynamically and efficiently fill any scheduling opportunities the resource presents benefit both the facility (maximal utilization) and the (compute-limited) science. The ATLAS Yoda system provides this capability to HENP-like event processing applications by implementing event-level processing in an MPI-based master-client model that integrates seamlessly with the more broadly scoped ATLAS Event Service. Fine grained, event level work assignments are intelligently dispatched to parallel workers to sustain full utilization on all cores, with outputs streamed off to destination object stores in near real time with similarly fine granularity, such that processing can proceed until termination with full utilization. The system offers the efficie...

  5. The fine-grained phase-space structure of Cold Dark Matter halos

    CERN Document Server

    Vogelsberger, Mark; Helmi, Amina; Springel, Volker

    2007-01-01

    We present a new and completely general technique for calculating the fine-grained phase-space structure of dark matter throughout the Galactic halo. Our goal is to understand this structure on the scales relevant for direct and indirect detection experiments. Our method is based on evaluating the geodesic deviation equation along the trajectories of individual DM particles. It requires no assumptions about the symmetry or stationarity of the halo formation process. In this paper we study general static potentials which exhibit more complex behaviour than the separable potentials studied previously. For ellipsoidal logarithmic potentials with a core, phase mixing is sensitive to the resonance structure, as indicated by the number of independent orbital frequencies. Regions of chaotic mixing can be identified by the very rapid decrease in the real space density of the associated dark matter streams. We also study the evolution of stream density in ellipsoidal NFW halos with radially varying isopotential shape,...

  6. Fine-grained facial phenotype–genotype analysis in Wolf–Hirschhorn syndrome

    Science.gov (United States)

    Hammond, Peter; Hannes, Femke; Suttie, Michael; Devriendt, Koen; Vermeesch, Joris Robert; Faravelli, Francesca; Forzano, Francesca; Parekh, Susan; Williams, Steve; McMullan, Dominic; South, Sarah T; Carey, John C; Quarrell, Oliver

    2012-01-01

    Wolf–Hirschhorn syndrome is caused by anomalies of the short arm of chromosome 4. About 55% of cases are due to de novo terminal deletions, 40% from unbalanced translocations and 5% from other abnormalities. The facial phenotype is characterized by hypertelorism, protruding eyes, prominent glabella, broad nasal bridge and short philtrum. We used dense surface modelling and pattern recognition techniques to delineate the milder facial phenotype of individuals with a small terminal deletion (breakpoint within 4p16.3) compared to those with a large deletion (breakpoint more proximal than 4p16.3). Further, fine-grained facial analysis of several individuals with an atypical genotype and/or phenotype suggests that multiple genes contiguously contribute to the characteristic Wolf–Hirschhorn syndrome facial phenotype. PMID:21792232

  7. Fine-grained facial phenotype-genotype analysis in Wolf-Hirschhorn syndrome.

    Science.gov (United States)

    Hammond, Peter; Hannes, Femke; Suttie, Michael; Devriendt, Koen; Vermeesch, Joris Robert; Faravelli, Francesca; Forzano, Francesca; Parekh, Susan; Williams, Steve; McMullan, Dominic; South, Sarah T; Carey, John C; Quarrell, Oliver

    2012-01-01

    Wolf-Hirschhorn syndrome is caused by anomalies of the short arm of chromosome 4. About 55% of cases are due to de novo terminal deletions, 40% from unbalanced translocations and 5% from other abnormalities. The facial phenotype is characterized by hypertelorism, protruding eyes, prominent glabella, broad nasal bridge and short philtrum. We used dense surface modelling and pattern recognition techniques to delineate the milder facial phenotype of individuals with a small terminal deletion (breakpoint within 4p16.3) compared to those with a large deletion (breakpoint more proximal than 4p16.3). Further, fine-grained facial analysis of several individuals with an atypical genotype and/or phenotype suggests that multiple genes contiguously contribute to the characteristic Wolf-Hirschhorn syndrome facial phenotype.

  8. Recrystallization behaviour of fine-grained magnesium alloy after hot deformation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Annealing behaviors of hot-deformed magnesium alloy AZ31 were studied at temperatures from 300 to 673 K by optical and SEM/EBSD metallographic observation. Temperature dependence of the average grain size(D) is categorized into three temperature regions, i.e. an incubation period for grain growth, rapid grain coarsening, and normal grain growth. The number of fine grains per unit area, however, is reduced remarkably even in incubation period. This leads to grain coarsening taking place continuously in the whole temperature regions. In contrast, the deformation texture scarcely changes even after full annealing at high temperatures. It is concluded that the annealing processes operating in hot-deformed magnesium alloy with continuous dynamic recrystallized grain structures can be mainly controlled by grain coarsening accompanied with no texture change, that is, continuous static recrystallization.

  9. Friction and Wear Performance of Boron Doped, Undoped Microcrystalline and Fine Grained Composite Diamond Films

    Institute of Scientific and Technical Information of China (English)

    WANG Xinchang; WANG Liang; SHEN Bin; SUN Fanghong

    2015-01-01

    Chemical vapor deposition (CVD) diamond films have attracted more attentions due to their excellent mechanical properties. Whereas as-fabricated traditional diamond films in the previous studies don’t have enough adhesion or surface smoothness, which seriously impact their friction and wear performance, and thus limit their applications under extremely harsh conditions. A boron doped, undoped microcrystalline and fine grained composite diamond (BD-UM-FGCD) film is fabricated by a three-step method adopting hot filament CVD (HFCVD) method in the present study, presenting outstanding comprehensive performance, including the good adhesion between the substrate and the underlying boron doped diamond (BDD) layer, the extremely high hardness of the middle undoped microcrystalline diamond (UMCD) layer, as well as the low surface roughness and favorable polished convenience of the surface fine grained diamond (FGD) layer. The friction and wear behavior of this composite film sliding against low-carbon steel and silicon nitride balls are studied on a ball-on-plate rotational friction tester. Besides, its wear rate is further evaluated under a severer condition using an inner-hole polishing apparatus, with low-carbon steel wire as the counterpart. The test results show that the BD-UM-FGCD film performs very small friction coefficient and great friction behavior owing to its high surface smoothness, and meanwhile it also has excellent wear resistance because of the relatively high hardness of the surface FGD film and the extremely high hardness of the middle UMCD film. Moreover, under the industrial conditions for producing low-carbon steel wires, this composite film can sufficiently prolong the working lifetime of the drawing dies and improve their application effects. This research develops a novel composite diamond films owning great comprehensive properties, which have great potentials as protecting coatings on working surfaces of the wear-resistant and anti

  10. Fine-grained semantic categorization across the abstract and concrete domains.

    Directory of Open Access Journals (Sweden)

    Marta Ghio

    Full Text Available A consolidated approach to the study of the mental representation of word meanings has consisted in contrasting different domains of knowledge, broadly reflecting the abstract-concrete dichotomy. More fine-grained semantic distinctions have emerged in neuropsychological and cognitive neuroscience work, reflecting semantic category specificity, but almost exclusively within the concrete domain. Theoretical advances, particularly within the area of embodied cognition, have more recently put forward the idea that distributed neural representations tied to the kinds of experience maintained with the concepts' referents might distinguish conceptual meanings with a high degree of specificity, including those within the abstract domain. Here we report the results of two psycholinguistic rating studies incorporating such theoretical advances with two main objectives: first, to provide empirical evidence of fine-grained distinctions within both the abstract and the concrete semantic domains with respect to relevant psycholinguistic dimensions; second, to develop a carefully controlled linguistic stimulus set that may be used for auditory as well as visual neuroimaging studies focusing on the parametrization of the semantic space beyond the abstract-concrete dichotomy. Ninety-six participants rated a set of 210 sentences across pre-selected concrete (mouth, hand, or leg action-related and abstract (mental state-, emotion-, mathematics-related categories, with respect either to different semantic domain-related scales (rating study 1, or to concreteness, familiarity, and context availability (rating study 2. Inferential statistics and correspondence analyses highlighted distinguishing semantic and psycholinguistic traits for each of the pre-selected categories, indicating that a simple abstract-concrete dichotomy is not sufficient to account for the entire semantic variability within either domains.

  11. Fine-grained suspended sediment source identification for the Kharaa River basin, northern Mongolia

    Science.gov (United States)

    Rode, Michael; Theuring, Philipp; Collins, Adrian L.

    2015-04-01

    Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on the water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (water flows, to collect an overall total of 900 sediment samples. The work used a statistical approach for sediment source discrimination with geochemical composite fingerprints based on a new Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal-Wallis H-test and Principal Component Analysis. The composite fingerprints were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin) with the pattern generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of riverbank erosion was shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the general applicability and associated uncertainties of an approach for fine-grained sediment source investigation in large scale semi-arid catchments. The combined application of source fingerprinting and catchment modelling approaches can be used to assess whether tracing estimates are credible and in combination such approaches provide a basis for making sediment source apportionment more compelling to catchment stakeholders and managers.

  12. Friction and wear performance of boron doped, undoped microcrystalline and fine grained composite diamond films

    Science.gov (United States)

    Wang, Xinchang; Wang, Liang; Shen, Bin; Sun, Fanghong

    2015-01-01

    Chemical vapor deposition (CVD) diamond films have attracted more attentions due to their excellent mechanical properties. Whereas as-fabricated traditional diamond films in the previous studies don't have enough adhesion or surface smoothness, which seriously impact their friction and wear performance, and thus limit their applications under extremely harsh conditions. A boron doped, undoped microcrystalline and fine grained composite diamond (BD-UM-FGCD) film is fabricated by a three-step method adopting hot filament CVD (HFCVD) method in the present study, presenting outstanding comprehensive performance, including the good adhesion between the substrate and the underlying boron doped diamond (BDD) layer, the extremely high hardness of the middle undoped microcrystalline diamond (UMCD) layer, as well as the low surface roughness and favorable polished convenience of the surface fine grained diamond (FGD) layer. The friction and wear behavior of this composite film sliding against low-carbon steel and silicon nitride balls are studied on a ball-on-plate rotational friction tester. Besides, its wear rate is further evaluated under a severer condition using an inner-hole polishing apparatus, with low-carbon steel wire as the counterpart. The test results show that the BD-UM-FGCD film performs very small friction coefficient and great friction behavior owing to its high surface smoothness, and meanwhile it also has excellent wear resistance because of the relatively high hardness of the surface FGD film and the extremely high hardness of the middle UMCD film. Moreover, under the industrial conditions for producing low-carbon steel wires, this composite film can sufficiently prolong the working lifetime of the drawing dies and improve their application effects. This research develops a novel composite diamond films owning great comprehensive properties, which have great potentials as protecting coatings on working surfaces of the wear-resistant and anti

  13. Source identification of fine-grained suspended sediment in the Kharaa River basin, northern Mongolia

    Energy Technology Data Exchange (ETDEWEB)

    Theuring, Philipp [Department of Aquatic Ecosystem Analysis and Management — ASAM, Helmholtz Centre for Environmental Research — UFZ, Brückstrasse 3a, D-39114 Magdeburg (Germany); Collins, Adrian L. [Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB (United Kingdom); Rode, Michael [Department of Aquatic Ecosystem Analysis and Management — ASAM, Helmholtz Centre for Environmental Research — UFZ, Brückstrasse 3a, D-39114 Magdeburg (Germany)

    2015-09-01

    Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (< 10 μm) sediment in the 15 000 km{sup 2} Kharaa River basin in northern Mongolia. Variation in geochemical composition (e.g. in Ti, Sn, Mo, Mn, As, Sr, B, U, Ca and Sb) was used for sediment source discrimination with geochemical composite fingerprints based on Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal–Wallis H-test and Principal Component Analysis. All composite fingerprints yielded a satisfactory GOF (> 0.97) and were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin), generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of river bank erosion is shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the applicability and associated uncertainties of the approach for fine-grained sediment source investigation in large scale semi-arid catchments. - Highlights: • Applied statistical approach for selecting composite fingerprints in Mongolia. • Geochemical fingerprinting for the definition of source areas in semiarid catchment. • Test of applicability of sediment sourcing in large scale semi-arid catchments

  14. An Analysis of the Joints’ Properties of Fine-Grained Steel Welded by the MAG and SAW Methods

    Directory of Open Access Journals (Sweden)

    Krawczyk R.

    2016-09-01

    Full Text Available The article presents an analysis of properties of welded joints of fine-grained steel of P460NH type used more and more often in the modern constructions. A process of examining a technology of welding has been carried out on the thick-walled butt joints of sheet metal by two methods of welding namely MAG – 135 and SAW – 121. The article deals with a topic of optimizing a process of welding thick-walled welded joints of fine-grained steel due to their mechanicalproperties and efficiency.

  15. Impact energy analysis of quenched and tempered fine grain structural steel specimens after weld thermal cycle simulation

    Directory of Open Access Journals (Sweden)

    M. Dunđer

    2014-10-01

    Full Text Available The paper presents impact energy results of thermal cycle simulated specimens of quenched and tempered fine grain structural steel S960QL. These results are obtained by examining notched Charpy specimens. Upon performed metallographic analysis and measured hardness, total impact energy is separated into ductile and brittle components.

  16. Incorporation of Fine-Grained Sediment Erodibility Measurements into Sediment Transport Modeling, Capitol Lake, Washington

    Science.gov (United States)

    Stevens, Andrew W.; Gelfenbaum, Guy; Elias, Edwin; Jones, Craig

    2008-01-01

    Capitol Lake was created in 1951 with the construction of a concrete dam and control gate that prevented salt-water intrusion into the newly formed lake and regulated flow of the Deschutes River into southern Puget Sound. Physical processes associated with the former tidally dominated estuary were altered, and the dam structure itself likely caused an increase in retention of sediment flowing into the lake from the Deschutes River. Several efforts to manage sediment accumulation in the lake, including dredging and the construction of sediment traps upriver, failed to stop the lake from filling with sediment. The Deschutes Estuary Feasibility Study (DEFS) was carried out to evaluate the possibility of removing the dam and restoring estuarine processes as an alternative ongoing lake management. An important component of DEFS was the creation of a hydrodynamic and sediment transport model of the restored Deschutes Estuary. Results from model simulations indicated that estuarine processes would be restored under each of four restoration alternatives, and that over time, the restored estuary would have morphological features similar to the predam estuary. The model also predicted that after dam-removal, a large portion of the sediment eroded from the lake bottom would be deposited near the Port of Olympia and a marina located in lower Budd Inlet seaward of the present dam. The volume of sediment transported downstream was a critical piece of information that managers needed to estimate the total cost of the proposed restoration project. However, the ability of the model to predict the magnitude of sediment transport in general and, in particular, the volume of sediment deposition in the port and marina was limited by a lack of information on the erodibility of fine-grained sediments in Capitol Lake. Cores at several sites throughout Capitol Lake were collected between October 31 and November 1, 2007. The erodibility of sediments in the cores was later determined in the

  17. Chemical weathering trends in fine-grained ephemeral stream sediments of the McMurdo Dry Valleys, Antarctica

    Science.gov (United States)

    Marra, Kristen R.; Elwood Madden, Megan E.; Soreghan, Gerilyn S.; Hall, Brenda L.

    2017-03-01

    We investigated chemical weathering trends within the fine-grained ( 40 m2/g. Utilization of MFW (mafic-felsic-weathered) and A-CN-K (Al2O3-CaO + Na2O-K2O) plots, however, are more effective in discerning the extent and nature of chemical weathering in these stream systems. Ca and Na depletion observed within the sediments exhibiting the highest surface area in Delta Stream suggest that chemical weathering may result in pitting and/or incongruent dissolution of pyroxenes and feldspars, as well as the development of amorphous and/or nanophase weathering products. In contrast, Clark Glacier stream sediments do not have similar leaching trends in the fine-grained sediment fraction and exhibit minimal weathering overall. This may suggest that fine-grained material is being trapped on top of the Clark Glacier surface and has not yet been transported into the weathering environment of the hyporheic zone due to timing of sampling. Alternatively, complete dissolution of very fine-grained sediment could be occurring in this stream transect, and is therefore not preserved in the fine sediment fraction. Overall, the magnitude of chemical weathering observed between the two stream systems is ultimately related to the nature of the underlying drift (cold and wet-based drift deposition), dispersal patterns of eolian fines, and variable stream discharge rates. Thus, incorporation of local fine-grained sediment derived from the underlying glacial drift deposits and distributed via the varying wind regimes within the hyper-arid climate into active stream channels may facilitate incongruent mineral dissolution and development of weathering products, and ultimately influence the composition and concentration of meltwater stream solutes.

  18. Participation of a cyanobacterial S layer in fine-grain mineral formation.

    Science.gov (United States)

    Schultze-Lam, S; Harauz, G; Beveridge, T J

    1992-12-01

    Cyanobacteria belonging to the Synechococcus group are ubiquitous inhabitants of diverse marine and freshwater environments. Through interactions with the soluble constituents of their aqueous habitats, they inevitably affect the chemistry of the waters they inhabit. Synechococcus strain GL24 was isolated from Fayetteville Green Lake, New York, where it has a demonstrated role in the formation of calcitic minerals. In order to understand the detailed interactions which lead to mineral formation by this organism, we have undertaken detailed ultrastructural studies of its cell surface and the initial events in mineral growth using a variety of electron microscopic and computer image enhancement techniques. Synechococcus strain GL24 has a hexagonally symmetrical S layer as its outermost cell surface component. The constituent protein(s) of this structure appears as a double band by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with M(r)s of 104,000 and 109,000. We demonstrate that the S layer acts as a template for fine-grain gypsum and calcite formation by providing discrete, regularly arranged nucleation sites for the critical initial events in the mineralization process. To our knowledge, this is the first time that a bacterial S layer has been shown to have a role in mineral formation in a natural environment, and this report provides conclusive evidence for the specific involvement of bacterial surfaces in natural mineral formation processes.

  19. Precipitation Processes during Non-Isothermal Ageing of Fine-Grained 2024 Alloy

    Directory of Open Access Journals (Sweden)

    Kozieł J.

    2016-03-01

    Full Text Available Mechanical alloying and powder metallurgy procedures were used to manufacture very fine-grained bulk material made from chips of the 2024 aluminum alloy. Studies of solution treatment and precipitation hardening of as-received material were based on differential scanning calorimetry (DSC tests and TEM/STEM/EDX structural observations. Structural observations complemented by literature data lead to the conclusion that in the case of highly refined structure of commercial 2024 alloys prepared by severe plastic deformation, typical multi-step G-P-B →θ” →θ’ →θ precipitation mechanism accompanied with G-P-B →S” →S’ →S precipitation sequences result in skipping the formation of metastable phases and direct growth of the stable phases. Exothermic effects on DSC characteristics, which are reported for precipitation sequences in commercial materials, were found to be reduced with increased milling time. Moreover, prolonged milling of 2024 chips was found to shift the exothermic peak to lower temperature with respect to the material produced by means of common metallurgy methods. This effect was concluded to result from preferred heterogeneous nucleation of particles at subboundaries and grain boundaries, enhanced by the boundary diffusion in highly refined structures.

  20. Sources of fine-grained sediment to streams using fallout radionuclides in the Midwestern United States

    Science.gov (United States)

    Gellis, A.; Fuller, C. C.; Van Metre, P. C.

    2014-12-01

    Fluvial sediment is a major factor in aquatic habitat degradation. Understanding the sources of this sediment is a necessary component of management plans and policies aimed at reducing sediment inputs. Because of the time intensive framework of most sediment-source studies, spatial interpretations are often limited to the study watershed. To address sediment sources on a larger scale, the U.S. Geological Survey- National Water Quality Assessment (NAWQA) Program as part of the Midwest Stream Quality Assessment, used fallout radioisotopes (excess lead-210, cesium-137, and beryllium-7) to determine the source ((upland (surface runoff) or channel derived)) of fine-grained (states in the Midwestern United States covering 648,239 km2 of the United States. Sampling occurred in July and August of 2013, in conjunction with water chemistry, aquatic-habitat and ecological community assessments. Ninety-nine watersheds were sampled, the majority of which were predominately agricultural, with contributing areas ranging between 6.7 to 5,893 km2. Using the ratio of beryllium-7 to excess lead-210, the percent of upland to channel-derived sediment was estimated. Results indicate that sediment sources vary among the 99 watersheds. Channel sediment is an important source presumably from bank erosion. Upland sediment was not the dominant source of sediment in many of these agricultural watersheds. Suspended-sediment samples collected over an 8-week period for 3 watersheds also show that the percent of upland versus channel sediment varies spatially and temporally.

  1. Fine-grained parallelism accelerating for RNA secondary structure prediction with pseudoknots based on FPGA.

    Science.gov (United States)

    Xia, Fei; Jin, Guoqing

    2014-06-01

    PKNOTS is a most famous benchmark program and has been widely used to predict RNA secondary structure including pseudoknots. It adopts the standard four-dimensional (4D) dynamic programming (DP) method and is the basis of many variants and improved algorithms. Unfortunately, the O(N(6)) computing requirements and complicated data dependency greatly limits the usefulness of PKNOTS package with the explosion in gene database size. In this paper, we present a fine-grained parallel PKNOTS package and prototype system for accelerating RNA folding application based on FPGA chip. We adopted a series of storage optimization strategies to resolve the "Memory Wall" problem. We aggressively exploit parallel computing strategies to improve computational efficiency. We also propose several methods that collectively reduce the storage requirements for FPGA on-chip memory. To the best of our knowledge, our design is the first FPGA implementation for accelerating 4D DP problem for RNA folding application including pseudoknots. The experimental results show a factor of more than 50x average speedup over the PKNOTS-1.08 software running on a PC platform with Intel Core2 Q9400 Quad CPU for input RNA sequences. However, the power consumption of our FPGA accelerator is only about 50% of the general-purpose micro-processors.

  2. Mechanical properties of fine-grained dual phase low-carbon steels based on dynamic transformation

    Institute of Scientific and Technical Information of China (English)

    Haiwei Xu; Wangyue rang; Zuqing Sun

    2008-01-01

    The fine grained dual phase (FG-DP) steel with ferrite grains of 2-4.5 μm and martensite islands smaller than 3 μm was obtained through the mechanism of deformation-enhanced ferrite transformation (DEFT). Mechanical properties of the steel were tested at room temperature. The results indicated that with a similar volume fraction of martensite (about 20vol%), FG-DP steel ex-hibited a superior combination of higher strength and more rapid strain hardening at low strains compared with the coarse-grained dual phase (CG-DP) steel obtained by critical annealing. The combination of higher strength, large elongation, and more rapid strain hardening of FG-DP steel can be attributed to the fine ferrite grain and finely dispersed martensite islands. In addition, the uniformly distributed martensite islands in FG-DP steel have smaller interspaeing compared with that of CG-DP steel. So, at the initial plastic deformation stage, the plastic deformation of ferrite was restrained and more pronounced load was transferred from ferrite to marten-site. The plastic deformation of martensite in FG-DP steel started earlier.

  3. Fine grain separation for the production of biomass fuel from mixed municipal solid waste.

    Science.gov (United States)

    Giani, H; Borchers, B; Kaufeld, S; Feil, A; Pretz, T

    2016-01-01

    The main goal of the project MARSS (Material Advanced Sustainable Systems) is to build a demonstration plant in order to recover a renewable biomass fuel suitable for the use in biomass power plants out of mixed municipal solid waste (MMSW). The demonstration plant was constructed in Mertesdorf (Germany), working alongside an existing mechanical-biological treatment plant, where the MMSW is biological dried under aerobe conditions in rotting boxes. The focus of the presented sorting campaign was set on the processing of fine grain particles minor than 11.5mm which have the highest mass content and biogenic energy potential of the utilized grain size fractions. The objective was to produce a biomass fuel with a high calorific value and a low content of fossil (plastic, synthetic) materials while maximizing the mass recovery. Therefore, the biogenic components of the dried MMSW are separated from inert and fossil components through various classification and sifting processes. In three experimental process setups of different processing depths, the grain size fraction 4-11.5mm was sifted by the use of air sifters and air tables.

  4. Development and evaluation of a geographic information retrieval system using fine grained toponyms

    Directory of Open Access Journals (Sweden)

    Damien Palacio

    2015-12-01

    Full Text Available Geographic information retrieval (GIR is concerned with returning information in response to an information need, typically expressed in terms of a thematic and spatial component linked by a spatial relationship. However, evaluation initiatives have often failed to show significant differences between simple text baselines and more complex spatially enabled GIR approaches. We explore the effectiveness of three systems (a text baseline, spatial query expansion, and a full GIR system utilizing both text and spatial indexes at retrieving documents from a corpus describing mountaineering expeditions, centred around fine grained toponyms. To allow evaluation, we use user generated content (UGC in the form of metadata associated with individual articles to build a test collection of queries and judgments. The test collection allowed us to demonstrate that a GIR-based method significantly outperformed a text baseline for all but very specific queries associated with very small query radii. We argue that such approaches to test collection development have much to offer in the evaluation of GIR.

  5. SOTB Implementation of a Field Programmable Gate Array with Fine-Grained Vt Programmability

    Directory of Open Access Journals (Sweden)

    Masakazu Hioki

    2014-07-01

    Full Text Available Field programmable gate arrays (FPGAs are one of the most widespread reconfigurable devices in which various functions can be implemented by storing circuit connection information and logic values into configuration memories. One of the most important issues in the modern FPGA is the reduction of its static leakage power consumption. Flex Power FPGA, which has been proposed to overcome this problem, uses a body biasing technique to implement the fine-grained threshold voltage (Vt programmability in the FPGA. A low-Vt state can be assigned only to the component circuits along the critical path of the application design mapped on the FPGA, so that the static leakage power consumption can be reduced drastically. Flex Power FPGA is an important application target for the SOTB (silicon on thin buried oxide device, which features a wide-range body biasing ability and the high sensitivity of Vt variation by body biasing, resulting in a drastic subthreshold leakage current reduction caused by static leakage power. In this paper, the Flex Power FPGA test chip is fabricated in SOTB technology, and the functional test and performance evaluation of a mapped 32-bit binary counter circuit are performed successfully. As a result, a three orders of magnitude static leakage reduction with a bias range of 2.1 V demonstrates the excellent Vt controllability of the SOTB transistors, and the 1.2 V bias difference achieves a 50× leakage reduction without degrading speed.

  6. Equal channel angular deformation process and its neuro-simulation for fine-grained magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    LUO Peng(罗蓬); HU Qiao-dan(胡侨丹); WU Xiao-lin; XIA Ke-nong

    2004-01-01

    Fine-grained structure of as-cast magnesium AM60 alloy was obtained by means of equal channel angular deformation(ECAD) technique. Through analyzing the relationship between the load and the displacement under different working conditions, it is demonstrated that employment of back-pressure, multi-passages of deformation, and speed of deformation are the main factors representing ECAD working condition. As for ECAD process, a network composed of nonlinear neuro-element based on error back-propagation learning algorithm is launched to set up a processing mapping module for dynamic forecasting of load summit under different working conditions. The experimental results show that back-pressure, multi-passages and deforming speed have strong correlation with ECAD processing characteristics. On the metallographs of AM60 alloy after multi-passes ECAD, a morphology that inter-metallic compound Mg17 Al12 precipites on magnesium matrix without discrepancy, which evolves from coarse casting ingot microstructure, is observed. And the grains are refined significantly under accumulated severe shear strain.The study demonstrates feasibility of ECAD by using as-cast magnesium alloy directly, and launches an intelligent neuro-simulation module for quantitative analysis of its process.

  7. Correlative multi-scale characterization of a fine grained Nd–Fe–B sintered magnet

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, T.T., E-mail: sasaki.taisuke@nims.go.jp [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Ohkubo, T.; Hono, K. [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Une, Y.; Sagawa, M. [Intermetallics Co., Ltd., 1-36 Goryo Ohara, Nishikyo-Ku, Kyoto 615-8245 (Japan)

    2013-09-15

    The Nd-rich phases in pressless processed fine grained Nd–Fe–B sintered magnets have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and three dimensional atom probe tomography (3DAP). The combination of the backscattered electron (BSE) and in-lens secondary electron (IL-SE) images in SEM led to an unambiguous identification of four types of Nd-rich phases, NdO{sub x}, Ia3{sup ¯} type phase, which is isostructural to Nd{sub 2}O{sub 3}, dhcp-Nd and Nd{sub 1}Fe{sub 4}B{sub 4}. In addition, the 3DAP analysis of thin Nd-rich grain boundary layer indicate that the coercivity has a close correlation with the chemistry of the grain boundary phase. - Highlights: ► Multi-scale characterization of Nd–Fe–B sintered magnet by SEM/TEM/3DAP. ► Phase/chemistry identification of Nd-rich phases at grain boundary triple junctions. ► Identification of micron-scale distribution of Nd-rich phases by IL-SE and BSE SEM. ► Correlative SEM/3DAP analysis from a specific thin grain boundary phase.

  8. A Fine-Grained Data Access Control System in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Boniface K. Alese

    2015-12-01

    Full Text Available The evolving realities of Wireless Sensor Network (WSN deployed to various terrain of life require serving multiple applications. As large amount of sensed data are distributed and stored in individual sensors nodes, the illegal access to these sensitive data can be devastating. Consequently, data insecurity becomes a big concern. This study, therefore, proposes a fine-grained access control system which only requires the right set of users to access a particular data, based on their access privileges in the sensor networks. It is designed using Priccess Protocol with Access policy formulation adopting the principle of Bell Lapadula model as well as Attribute-Based Encryption (ABE to control access to sensor data. The functionality of the proposed system is simulated using Netbeans. The performance analysis of the proposed system using execution time and size of the key show that the higher the key size, the harder it becomes for the attacker to hack the system. Additionally, the time taken for the proposed work is lesser which makes the work faster than the existing work. Consequently, a well secure interactive web-based application that could facilitates the field officers access to stored data in safe and secure manner is developed.

  9. Microstructure and high temperature deformation of an ultra-fine grained ECAP AA7075 aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Malek, Premysl; Turba, Krystof; Cieslar, Miroslav; Harcuba, Petr [Charles Univ., Prague (Czech Republic). Dept. of Physics of Materials

    2013-01-15

    An AA 7075 aluminium alloy with an ultra-fine grained structure was prepared through equal channel angular pressing (ECAP) at pressing temperatures T ECAP of 120, 170, and 220 C. A decrease in T{sub ECAP} from 220 to 120 C was found to lead to a more pronounced refinement of the microstructure and to worse stability of the microstructure - the onset of grain coarsening was displaced to lower temperatures. The material pressed with the highest T{sub ECAP} exhibited superplastic behaviour at temperatures close to 400 C and grain boundary sliding was identified as the dominant operating deformation mechanism. The materials prepared with both of the lower T{sub ECAP} exhibited only enhanced ductility of about 200%, however this behaviour was observed at temperatures as low as 200 C. It was found that this 'low temperature superplasticity' resulted from a combined operation of grain boundary sliding at selected grain boundaries and glide of lattice dislocations. (orig.)

  10. Pseudoelastic cycling of ultra-fine-grained NiTi shape-memory wires

    Energy Technology Data Exchange (ETDEWEB)

    Yawny, A.; Sade, M. [Centro Atomico Bariloche, S.C. de Bariloche (Argentina); Eggeler, G. [Inst. fuer Werkstoffe, Ruhr-Univ. Bochum, Bochum (Germany)

    2005-06-01

    In the present study, we investigate pseudoelastic pull-pull cycling of ultra-fine-grained (40 nm) Ni-rich (50.9 at.% Ni) NiTi shape-memory wires at temperatures ranging from 301 to 323 K. Strain-controlled experiments were performed using incremental strain steps and different constant maximum strains. Pull-pull cycling results in decreasing/increasing plateau stresses characterizing the forward/reverse transformations and an accumulation of non-recoverable strain. Saturation is reached after 30 cycles. We interpret our results in terms of a microstructural scenario where dislocations, which are introduced during the martensitic transformation (lattice invariant shear) and during pull-pull cycling (dislocation plasticity), interact with the stress-induced formation of martensite. We show that the slopes of stress-strain curves naturally depend on the total strain imposed in strain-controlled testing. We also provide a dislocation-based explanation for the evolving stress levels of the loading and unloading plateaus during pseudoelastic cycling. And most importantly, we show how dislocations act as microstructural markers which allow the material to remember its previous stress-strain history. (orig.)

  11. Fine grained event processing on HPCs with the ATLAS Yoda system

    Science.gov (United States)

    Calafiura, Paolo; De, Kaushik; Guan, Wen; Maeno, Tadashi; Nilsson, Paul; Oleynik, Danila; Panitkin, Sergey; Tsulaia, Vakhtang; Van Gemmeren, Peter; Wenaus, Torre

    2015-12-01

    High performance computing facilities present unique challenges and opportunities for HEP event processing. The massive scale of many HPC systems means that fractionally small utilization can yield large returns in processing throughput. Parallel applications which can dynamically and efficiently fill any scheduling opportunities the resource presents benefit both the facility (maximal utilization) and the (compute-limited) science. The ATLAS Yoda system provides this capability to HEP-like event processing applications by implementing event-level processing in an MPI-based master-client model that integrates seamlessly with the more broadly scoped ATLAS Event Service. Fine grained, event level work assignments are intelligently dispatched to parallel workers to sustain full utilization on all cores, with outputs streamed off to destination object stores in near real time with similarly fine granularity, such that processing can proceed until termination with full utilization. The system offers the efficiency and scheduling flexibility of preemption without requiring the application actually support or employ check-pointing. We will present the new Yoda system, its motivations, architecture, implementation, and applications in ATLAS data processing at several US HPC centers.

  12. Freezing-thawing behaviour of fine-grained soils subjected to surcharge loads

    Directory of Open Access Journals (Sweden)

    Ahmet Şahin Zaimoğlu

    2013-03-01

    Full Text Available In cold climate zones, the shallow foundation soils belonging to civil engineering constructions such as highways, railways, irrigation channels are subject to freezing-thawing under these loads. In this study, with the purpose of representing such soils the freeze-thaw experiment has been carried out for the situation where load is applied on the samples in addition to the traditional method where there is no load on the sample. The experiments have been conducted on samples prepared with the compaction under standard proctor energy of fine grained soils. In the experiments conducted in the traditional method the unconfined compressive strength values of samples after 1, 3, 5 and 10 cycles have been determined. Then the freeze-thaw experiments were repeated while a load representing 25 %, 35 % and 50 % of these values was on the samples. As a result of the experiments conducted with both methods, the freeze-thaw resistances of the samples have been determined. It was observed that the freeze-thaw resistance values of soils under load are less than those found by the traditional method.

  13. cuBLASTP: Fine-Grained Parallelization of Protein Sequence Search on CPU+GPU.

    Science.gov (United States)

    Zhang, Jing; Wang, Hao; Feng, Wu-Chun

    2017-01-01

    BLAST, short for Basic Local Alignment Search Tool, is a ubiquitous tool used in the life sciences for pairwise sequence search. However, with the advent of next-generation sequencing (NGS), whether at the outset or downstream from NGS, the exponential growth of sequence databases is outstripping our ability to analyze the data. While recent studies have utilized the graphics processing unit (GPU) to speedup the BLAST algorithm for searching protein sequences (i.e., BLASTP), these studies use coarse-grained parallelism, where one sequence alignment is mapped to only one thread. Such an approach does not efficiently utilize the capabilities of a GPU, particularly due to the irregularity of BLASTP in both execution paths and memory-access patterns. To address the above shortcomings, we present a fine-grained approach to parallelize BLASTP, where each individual phase of sequence search is mapped to many threads on a GPU. This approach, which we refer to as cuBLASTP, reorders data-access patterns and reduces divergent branches of the most time-consuming phases (i.e., hit detection and ungapped extension). In addition, cuBLASTP optimizes the remaining phases (i.e., gapped extension and alignment with trace back) on a multicore CPU and overlaps their execution with the phases running on the GPU.

  14. Ultra-fine grained Al-Mg alloys with superior strength via physical simulation

    Science.gov (United States)

    Sabirov, I.; Enikeev, N.; Kazykhanov, V.; Valiev, R.; Murashkin, M.

    2014-08-01

    The Al 5xxx alloys are widely used in form of sheets in marine, transport, and chemical engineering and, thus, they are often have to undergo hot/cold rolling as the final metal forming operations. Recent investigations have demonstrated that ultra-fine grained (UFG) Al 5xxx alloys have a significant potential for industrial applications due to their improved mechanical properties and enhanced corrosion resistance. However, the development of hot/cold rolling routes for the UFG Al alloys is very time consuming due to numerous experimental trials and very expensive due to higher cost of the UFG processed materials. In this work, physical simulation of cold rolling is applied to the UFG Al 5083 alloy obtained via equal channel angular pressing with parallel channels to analyze the effect of cold rolling on the microstructure and microhardness of the material. The cold rolling parameters are chosen based on the outcomes of physical simulation and the UFG Al 5083 alloy is successfully subjected to cold rolling resulting in superior mechanical strength of the material. It is concluded that physical simulation can significantly increase the efficiency of experimental work on development of thermo-mechanical processing routes.

  15. Development of shrinkage and fracture parameters in selected fine-grained cement-based composites

    Directory of Open Access Journals (Sweden)

    Kucharczyková Barbara

    2017-01-01

    Full Text Available The paper summarizes results of a pilot study aimed at the evaluation of an experimental investigation focused on determination of the material characteristics development of selected fine-grained cement-based composites during their ageing. The composition of composites being investigated differed only in a water to cement (w/c ratio and in amount of superplasticizer. Quite extensive experiments were performed with the aim to determine shrinkage, dynamic a static modulus of elasticity and fracture properties on test specimens exposed to free drying during the whole time of its ageing (including the early stage of setting and hardening. The article presents especially results (including their statistical evaluation of shrinkage and fracture parameters development within 90 days of composites’ ageing. Experimental results show the dependence of the investigated characteristics on the value of w/c ratio. The most visible effect was observed in the case of shrinkage development. The curing conditions were reflected especially in high variability of the test results.

  16. Effect of zirconia addition on the fatigue behaviour of fine grained alumina

    Indian Academy of Sciences (India)

    D Basu; B K Sarkar

    2001-04-01

    The fatigue behaviour of fine grained Al2O3 and ZrO2 toughened Al2O3 (ZTA) compositions with 15 vol% ZrO2 (3 mol% Y2O3 stabilized: 3Y-TZP) have been investigated by using three different techniques. Primarily 4-point bending load was employed to generate tension–tension fatigue data under both static and cyclic conditions. The results clearly showed that the materials were susceptible to both the static and cyclic fatigue and the time to failure under cyclic loading was considerably shorter than the equivalent static loads. The repeated indentations at the same spot with varying loads showed a typical fatigue behaviour. In addition, both the materials were subjected to the repeated impact cycles at varying subcritical loads simulating impact fatigue. In all the cases typical fatigue curves were obtained having a progressive endurance at subcritical loads having an endurance limit. The fatigue behaviour of Al2O3 was much improved by the addition of 15 vol% 3Y-TZP, having micro-plasticity contributing towards the cyclic fatigue phenomena of these materials.

  17. FlexiWay: A Cache Energy Saving Technique Using Fine-grained Cache Reconfiguration

    Energy Technology Data Exchange (ETDEWEB)

    Mittal, Sparsh [ORNL; Zhang, Zhao [Iowa State University; Vetter, Jeffrey S [ORNL

    2013-01-01

    Recent trends of CMOS scaling and use of large last level caches (LLCs) have led to significant increase in the leakage energy consumption of LLCs and hence, managing their energy consumption has become extremely important in modern processor design. The conventional cache energy saving techniques require offline profiling or provide only coarse granularity of cache allocation. We present FlexiWay, a cache energy saving technique which uses dynamic cache reconfiguration. FlexiWay logically divides the cache sets into multiple (e.g. 16) modules and dynamically turns off suitable and possibly different number of cache ways in each module. FlexiWay has very small implementation overhead and it provides fine-grain cache allocation even with caches of typical associativity, e.g. an 8-way cache. Microarchitectural simulations have been performed using an x86-64 simulator and workloads from SPEC2006 suite. Also, FlexiWay has been compared with two conventional energy saving techniques. The results show that FlexiWay provides largest energy saving and incurs only small loss in performance. For single, dual and quad core systems, the average energy saving using FlexiWay are 26.2%, 25.7% and 22.4%, respectively.

  18. Fine-Grained Rate Shaping for Video Streaming over Wireless Networks

    Directory of Open Access Journals (Sweden)

    Chen Tsuhan

    2004-01-01

    Full Text Available Video streaming over wireless networks faces challenges of time-varying packet loss rate and fluctuating bandwidth. In this paper, we focus on streaming precoded video that is both source and channel coded. Dynamic rate shaping has been proposed to “shape” the precompressed video to adapt to the fluctuating bandwidth. In our earlier work, rate shaping was extended to shape the channel coded precompressed video, and to take into account the time-varying packet loss rate as well as the fluctuating bandwidth of the wireless networks. However, prior work on rate shaping can only adjust the rate oarsely. In this paper, we propose “fine-grained rate shaping (FGRS” to allow for bandwidth adaptation over a wide range of bandwidth and packet loss rate in fine granularities. The video is precoded with fine granularity scalability (FGS followed by channel coding. Utilizing the fine granularity property of FGS and channel coding, FGRS selectively drops part of the precoded video and still yields decodable bit-stream at the decoder. Moreover, FGRS optimizes video streaming rather than achieves heuristic objectives as conventional methods. A two-stage rate-distortion (RD optimization algorithm is proposed for FGRS. Promising results of FGRS are shown.

  19. Effect of welding heat input on HAZ character in ultra-fine grain steel welding

    Institute of Scientific and Technical Information of China (English)

    张富巨; 许卫刚; 王玉涛; 王燕; 张学刚; 廖永平

    2003-01-01

    In this essay, we studied how heat input affected the microstructure, hardness, grain size and heat-affected zone(HAZ) dimension of WCX355 ultra-fine grain steel which was welded respectively by the ultra narrow-gap welding (UNGW) process and the overlaying process with CO2 as protective atmosphere and laser welding process. The experimental results show when the heat input changed from 1.65kJ/cm to 5.93kJ/cm, the width of its HAZ ranged from 0.6mm to 2.1mm.The average grain size grew up from 2~5μm of base metal to 20~70μm and found no obvious soften phenomenon in overheated zone. The width of normalized zone was generally wide as 2/3 as that of the whole HAZ, and the grain size in this zone is smaller than that in base metal. Under the circumstance of equal heat input, the HAZ width of UNGW is narrower than that of the laser welding.

  20. Many-body dissipative particle dynamics modeling of fluid flow in fine-grained nanoporous shales

    Science.gov (United States)

    Xia, Yidong; Goral, Jan; Huang, Hai; Miskovic, Ilija; Meakin, Paul; Deo, Milind

    2017-05-01

    A many-body dissipative particle dynamics model, namely, MDPD, is applied for simulation of pore-scale, multi-component, multi-phase fluid flows in fine-grained, nanoporous shales. Since this model is able to simultaneously capture the discrete features of fluid molecules in nanometer size pores and continuum fluid dynamics in larger pores, and is relatively easy to parameterize, it has been recognized as being particularly suitable for simulating complex fluid flow in multi-length-scale nanopore networks of shales. A remarkable feature of this work is the integration of a high-resolution FIB-SEM (focused ion beam scanning electron microscopy) digital imaging technique to the MDPD model for providing 3D voxel data that contain the invaluable geometrical and compositional information of shale samples. This is the first time that FIB-SEM is seamlessly linked to a Lagrangian model like MDPD for fluid flow simulation, which offers a robust approach to bridging gaps between the molecular- and continuum-scales, since the relevant spatial and temporal scales are too big for molecular dynamics, and too small for computational fluid dynamics with known constitutive models. Simulations ranging from a number of benchmark problems to a forced two-fluid flow in a Woodford shale sample are presented. Results indicate that this model can be used to deliver reasonable simulations for multi-component, multi-phase fluid flows in arbitrarily complex pore networks in shales.

  1. Supercooled interfacial water in fine grained soils probed by dielectric spectroscopy

    Science.gov (United States)

    Lorek, A.; Wagner, N.

    2013-04-01

    Water as thermodynamic state parameter affects nearly all physical, chemical and biological processes on the earth. Recent Mars observations as well as laboratory investigations suggest that water is also a key factor of current physical and chemical processes on the martian surface, e.g. rheological phenomena. Therefore it is of particular interest to get information about the liquid like state of water on martian analog soils in the temperature range below 0 °C. In this context, a parallel plate capacitor has been developed to obtain isothermal dielectric spectra of fine grained soils in the frequency range from 10 Hz to 1.1 MHz at martian like temperatures down to -70 °C. Two martian analogue soils have been investigated: a Ca-Bentonite (specific surface of 237 m2 g-1, up to 9.4% w/w gravimetric water content) and JSC Mars 1, a volcanic ash (specific surface of 146 m2 g-1, up to 7.4% w/w). Three soil-specific relaxation processes are observed in the investigated frequency-temperature range: two weak high frequency processes (bound or hydrated water as well as ice) and a strong low frequency process due to counter ion relaxation and the Maxwell-Wagner effect. To characterize the dielectric relaxation behavior, a generalized fractional dielectric relaxation model is applied assuming three active relaxation processes with relaxation time of the ith process according to an Eyring equation. The real part of effective complex soil permittivity at 350 kHz was used to determine ice and liquid like water content by means of the Birchak or CRIM equation. There are evidence that Bentonite down to -70 °C has a liquid like water content of 1.17 monolayers and JSC Mars 1 a liquid like water content of 1.96 mono layers.

  2. Supercooled interfacial water in fine-grained soils probed by dielectric spectroscopy

    Science.gov (United States)

    Lorek, A.; Wagner, N.

    2013-12-01

    Water substantially affects nearly all physical, chemical and biological processes on the Earth. Recent Mars observations as well as laboratory investigations suggest that water is a key factor of current physical and chemical processes on the Martian surface, e.g. rheological phenomena. Therefore it is of particular interest to get information about the liquid-like state of water on Martian analogue soils for temperatures below 0 °C. To this end, a parallel plate capacitor has been developed to obtain isothermal dielectric spectra of fine-grained soils in the frequency range from 10 Hz to 1.1 MHz at Martian-like temperatures down to -70 °C. Two Martian analogue soils have been investigated: a Ca-bentonite (specific surface of 237 m2 g-1, up to 9.4% w / w gravimetric water content) and JSC Mars 1, a volcanic ash (specific surface of 146 m2 g-1, up to 7.4% w / w). Three soil-specific relaxation processes are observed in the investigated frequency-temperature range: two weak high-frequency processes (bound or hydrated water as well as ice) and a strong low-frequency process due to counter-ion relaxation and the Maxwell-Wagner effect. To characterize the dielectric relaxation behaviour, a generalized fractional dielectric relaxation model was applied assuming three active relaxation processes with relaxation time of the ith process modelled with an Eyring equation. The real part of effective complex soil permittivity at 350 kHz was used to determine ice and liquid-like water content by means of the Birchak or CRIM equation. There are evidence that bentonite down to -70 °C has a liquid-like water content of 1.17 monolayers and JSC Mars 1 a liquid-like water content of 1.96 monolayers.

  3. Constitutive Analysis and Hot Deformation Behavior of Fine-Grained Mg-Gd-Y-Zr Alloys

    Science.gov (United States)

    Alizadeh, R.; Mahmudi, R.; Ruano, O. A.; Ngan, A. H. W.

    2017-09-01

    Mg-Gd-Y-Zr alloys are among the newly developed magnesium alloys with superior strength properties at elevated temperatures. Accordingly, the hot shear deformation behavior of fine-grained extruded Mg-9Gd-4Y-0.4Zr (GWK940), Mg-5Gd-4Y-0.4Zr (GWK540), and Mg-5Gd-0.4Zr (GK50) alloys was investigated using the localized shear punch testing (SPT) method. Shear punch tests were performed at 573 K, 623 K, 673 K, 723 K, and 773 K (300 °C, 350 °C, 400 °C, 450 °C, and 500 °C) under shear strain rates in the range of 6.7 × 10-3 to 6.7 × 10-2 s-1. The new fitting method of Rieiro, Carsi, and Ruano was used for direct calculation of the Garofalo constants. It was concluded that the Garofalo equation can be used satisfactorily for describing the deformation behavior of the alloys in the entire studied ranges of strain rates and temperatures. In addition, stability maps were obtained by calculations based on the Lyapunov criteria using the Garofalo constants. The predicted stability ranges of temperature and strain rate were similar for the studied alloys. At an intermediate strain rate of 0.05 s-1, the optimal temperature at which a stable region is expected was found to be 648 K to 673 K (375 °C to 400 °C) for all three materials. The most pronounced effect of the Gd and Y elements was to enhance the high-temperature strength of the alloys.

  4. The Stability of Fine-grained Sediments from the Fraser River Delta

    Science.gov (United States)

    Amos, C. L.; Feeney, T.; Sutherland, T. F.; Luternauer, J. L.

    1997-10-01

    The stability and erodibility of benthic fine-grained sediments on the foreshore and upper foreslope of the Fraser River delta were measured using the in situbenthic flume—Sea Carousel. The erosion threshold [τ c(0)], which varied between 0·11 and 0·50 Pa, was inversely related to erosion rate. It was also proportional to sediment wet bulk density (ρ b) in the form: τ c(0)=7×10 -4 ρ b-0·47. This trend agreed with those obtained from four other sites across Canada that encompassed a wide range in sediment densities: 1000Academic Press Limited Three erosion types were observed: Type IA erosion was a surface phenomenon caused by the presence of a thin organic ' fluff ' layer. It occurred at current speeds less than 0·3 m s -1. Type 1B erosion (asymptotically decaying with time) characterized the mid-portions of each erosion time series, and occurred at current speeds of 0·3-0·9 m s -1. Type I/II erosion (transitional) was largely found on the foreslope, and occurred at current speeds in excess of 0·8 m s -1. The erosion process began in all cases under turbulent transitional flows. The change from Type I to Type II erosion corresponded to the onset of turbulent rough flows (60result of entrainment of small aggregates and flocs, whereas Type II erosion was the result of enlargement of surface irregularities, and subsequent undercutting and release of large aggregates. Mean erosion rate ( Em) was independent of either azimuthal current speed or bed shear stress. It was largely constant throughout each deployment and varied between 1·4 and 7·4×10 -4 kg m -2 s -1.

  5. The mineralogy and chemistry of fine-grained sediments, Morphou Bay, Cyprus

    Directory of Open Access Journals (Sweden)

    C. Neal

    2002-01-01

    Full Text Available The mineralogy and chemistry of the less than 20μm fraction of marine sediments at Morphou Bay, north-west Cyprus, are presented to characterise fine-grained sediment supplies from basic and ultrabasic rocks of the Troodos Massif within a typological setting. The sediments comprise a mixture of smectite, illite, kaolinite and iron rich chlorite. They also contain amorphous iron oxides/hydroxides, calcite (with some magnesium substitution for calcium and an amphibole. Spatial patterns in mineralogy occur: the near-shore sediments are rich in smectite, chlorite, amphibole and amorphous iron oxides/hydroxides, while the offshore sediments are rich in illite and calcite. The sediments are calcium, magnesium, iron, aluminium and potassium bearing, due to the presence of significant amounts of calcite (for Ca, clay minerals and aluminium and iron oxides/hydroxides. Potassium is present within the micaceous mineral illite, but it is also contained within other phases that are difficult to pinpoint. Statistical analysis reveals that the chemical composition of the sediments broadly follows the mineralogy with the dominant feature being related to spatial changes in the mineralogy. The patterns of change reflect a three component mix of clay-sized sediment types: (1 localised lithogenous sources rich in smectite with subsidiary amounts of amorphous iron oxides/hydroxides and amphibole, from Cyprus, the Troodos in particular, (2 illite rich and smectite chlorite and chlorite bearing material of lithogenous origin from other parts of the eastern Mediterranean and (3 calcite, mainly of marine origin. Keywords: smectite, illite, chlorite, kaolinite, calcite, sediments, Morphou Bay, Troodos, Cyprus, Mediterranean, calcium, potassium, magnesium, iron, silicon, phosphorus.

  6. Fine-grained Database Field Search Using Attribute-Based Encryption for E-Healthcare Clouds.

    Science.gov (United States)

    Guo, Cheng; Zhuang, Ruhan; Jie, Yingmo; Ren, Yizhi; Wu, Ting; Choo, Kim-Kwang Raymond

    2016-11-01

    An effectively designed e-healthcare system can significantly enhance the quality of access and experience of healthcare users, including facilitating medical and healthcare providers in ensuring a smooth delivery of services. Ensuring the security of patients' electronic health records (EHRs) in the e-healthcare system is an active research area. EHRs may be outsourced to a third-party, such as a community healthcare cloud service provider for storage due to cost-saving measures. Generally, encrypting the EHRs when they are stored in the system (i.e. data-at-rest) or prior to outsourcing the data is used to ensure data confidentiality. Searchable encryption (SE) scheme is a promising technique that can ensure the protection of private information without compromising on performance. In this paper, we propose a novel framework for controlling access to EHRs stored in semi-trusted cloud servers (e.g. a private cloud or a community cloud). To achieve fine-grained access control for EHRs, we leverage the ciphertext-policy attribute-based encryption (CP-ABE) technique to encrypt tables published by hospitals, including patients' EHRs, and the table is stored in the database with the primary key being the patient's unique identity. Our framework can enable different users with different privileges to search on different database fields. Differ from previous attempts to secure outsourcing of data, we emphasize the control of the searches of the fields within the database. We demonstrate the utility of the scheme by evaluating the scheme using datasets from the University of California, Irvine.

  7. Fine-grained policy control in U.S. Army Research Laboratory (ARL) multimodal signatures database

    Science.gov (United States)

    Bennett, Kelly; Grueneberg, Keith; Wood, David; Calo, Seraphin

    2014-06-01

    The U.S. Army Research Laboratory (ARL) Multimodal Signatures Database (MMSDB) consists of a number of colocated relational databases representing a collection of data from various sensors. Role-based access to this data is granted to external organizations such as DoD contractors and other government agencies through a client Web portal. In the current MMSDB system, access control is only at the database and firewall level. In order to offer finer grained security, changes to existing user profile schemas and authentication mechanisms are usually needed. In this paper, we describe a software middleware architecture and implementation that allows fine-grained access control to the MMSDB at a dataset, table, and row level. Result sets from MMSDB queries issued in the client portal are filtered with the use of a policy enforcement proxy, with minimal changes to the existing client software and database. Before resulting data is returned to the client, policies are evaluated to determine if the user or role is authorized to access the data. Policies can be authored to filter data at the row, table or column level of a result set. The system uses various technologies developed in the International Technology Alliance in Network and Information Science (ITA) for policy-controlled information sharing and dissemination1. Use of the Policy Management Library provides a mechanism for the management and evaluation of policies to support finer grained access to the data in the MMSDB system. The GaianDB is a policy-enabled, federated database that acts as a proxy between the client application and the MMSDB system.

  8. Supercooled interfacial water in fine grained soils probed by dielectric spectroscopy

    Directory of Open Access Journals (Sweden)

    A. Lorek

    2013-04-01

    Full Text Available Water as thermodynamic state parameter affects nearly all physical, chemical and biological processes on the earth. Recent Mars observations as well as laboratory investigations suggest that water is also a key factor of current physical and chemical processes on the martian surface, e.g. rheological phenomena. Therefore it is of particular interest to get information about the liquid like state of water on martian analog soils in the temperature range below 0 °C. In this context, a parallel plate capacitor has been developed to obtain isothermal dielectric spectra of fine grained soils in the frequency range from 10 Hz to 1.1 MHz at martian like temperatures down to −70 °C. Two martian analogue soils have been investigated: a Ca-Bentonite (specific surface of 237 m2 g−1, up to 9.4% w/w gravimetric water content and JSC Mars 1, a volcanic ash (specific surface of 146 m2 g−1, up to 7.4% w/w. Three soil-specific relaxation processes are observed in the investigated frequency-temperature range: two weak high frequency processes (bound or hydrated water as well as ice and a strong low frequency process due to counter ion relaxation and the Maxwell–Wagner effect. To characterize the dielectric relaxation behavior, a generalized fractional dielectric relaxation model is applied assuming three active relaxation processes with relaxation time of the ith process according to an Eyring equation. The real part of effective complex soil permittivity at 350 kHz was used to determine ice and liquid like water content by means of the Birchak or CRIM equation. There are evidence that Bentonite down to −70 °C has a liquid like water content of 1.17 monolayers and JSC Mars 1 a liquid like water content of 1.96 mono layers.

  9. Supercooled interfacial water in fine-grained soils probed by dielectric spectroscopy

    Directory of Open Access Journals (Sweden)

    A. Lorek

    2013-12-01

    Full Text Available Water substantially affects nearly all physical, chemical and biological processes on the Earth. Recent Mars observations as well as laboratory investigations suggest that water is a key factor of current physical and chemical processes on the Martian surface, e.g. rheological phenomena. Therefore it is of particular interest to get information about the liquid-like state of water on Martian analogue soils for temperatures below 0 °C. To this end, a parallel plate capacitor has been developed to obtain isothermal dielectric spectra of fine-grained soils in the frequency range from 10 Hz to 1.1 MHz at Martian-like temperatures down to −70 °C. Two Martian analogue soils have been investigated: a Ca-bentonite (specific surface of 237 m2 g−1, up to 9.4% w / w gravimetric water content and JSC Mars 1, a volcanic ash (specific surface of 146 m2 g−1, up to 7.4% w / w. Three soil-specific relaxation processes are observed in the investigated frequency–temperature range: two weak high-frequency processes (bound or hydrated water as well as ice and a strong low-frequency process due to counter-ion relaxation and the Maxwell–Wagner effect. To characterize the dielectric relaxation behaviour, a generalized fractional dielectric relaxation model was applied assuming three active relaxation processes with relaxation time of the ith process modelled with an Eyring equation. The real part of effective complex soil permittivity at 350 kHz was used to determine ice and liquid-like water content by means of the Birchak or CRIM equation. There are evidence that bentonite down to −70 °C has a liquid-like water content of 1.17 monolayers and JSC Mars 1 a liquid-like water content of 1.96 monolayers.

  10. The Coarse-Grained/Fine-Grained Logic Interface in FPGAs with Embedded Floating-Point Arithmetic Units

    Directory of Open Access Journals (Sweden)

    Chi Wai Yu

    2008-01-01

    Full Text Available This paper examines the interface between fine-grained and coarse-grained programmable logic in FPGAs. Specifically, it presents an empirical study that covers the location, pin arrangement, and interconnect between embedded floating point units (FPUs and the fine-grained logic fabric in FPGAs. It also studies this interface in FPGAs which contain both FPUs and embedded memories. The results show that (1 FPUs should have a square aspect ratio; (2 they should be positioned near the center of the FPGA; (3 their I/O pins should be arranged around all four sides of the FPU; (4 embedded memory should be located between the FPUs; and (5 connecting higher I/O density coarse-grained blocks increases the demand for routing resources. The hybrid FPGAs with embedded memory required 12% wider channels than the case where embedded memory is not used.

  11. Development of bearing capacity of fine grained permafrost deposits in western greenland urban areas subject to soil temperature changes

    DEFF Research Database (Denmark)

    Agergaard, Frederik Ancker; Ingeman-Nielsen, Thomas

    2012-01-01

    by 2-3 °C during the 21st century. This paper presents a relation between undrained shear strength and temperature based on a series triaxial tests of fine-grained permafrost in the interval from -3 °C to -1 °C. Moderately ice-rich permafrost and excess ice free refrozen active-layer were retrieved...... with increasing temperature. Both excess ice free and moderately ice-rich samples show a strength decrease of 21 %/°C from -3 °C to -1 °C. Other authors’ data suggest the same trend for moderately ice-rich samples, whereas it is suggested that further studies are conducted to validate the trend for excess ice....... The established trends could provide a valuable tool for foundation design in fine-grained permafrost areas....

  12. Fracture-driven methane bubble ascent within shallow fine-grained clay-bearing aquatic sediments: dynamics and controlling factors

    Science.gov (United States)

    Tarboush Sirhan, Shahrazad; Katsman, Regina; Ten Brink, Uri

    2017-04-01

    Mature methane gas bubbles in the fine-grained, clay-bearing (cohesive) aquatic sediments, found at many locations throughout the world, are much larger than the characteristic pore size. When gas pressure within the bubble is high enough to overcome compression, friction, and cohesion at grain contacts, gas migrates upward driven by buoyancy, by pushing the grains apart and fracturing the fine-grained sediments. Fracturing of the fine-grained cohesive sediments by the migrating bubbles destabilizes sediment and might result in slope failure. Migrating methane bubbles may bypass processes of oxidation in the upper sediment layers due to their fast rise velocity, release to the water column and eventually to the atmosphere. In this study we use coupled macroscopic single-bubble mechanical/reaction-transport numerical model to explore bubble ascent under various ambient concentration profiles, associated with bio-chemical processes of methane production and consumption below sediment-water interface, as it occurs in nature. Modeling results show that changes in the ambient dissolved-methane concentrations strongly affect bubble ascent velocity. It is demonstrated that bubble migration scenario within fine-grained muddy sediments is controlled dominantly by the internal bubble pressure that manages solute exchange with adjacent porewater. It is significantly affected by the total hydrostatic pressure. For shallow water depths two sequential bubble propagation patterns were observed: (1) Stable (saw-tooth) fracturing, followed by (2) Dynamic (unstable, rising line) fracturing, leading to an ultimate release of the bubble to the water column. However, for a higher water depth, bubble propagation pattern is characterized by stable fracturing only. In this pattern the bubble becomes more sensitive to the ambient field of methane concentrations and may stop below sediment-water interface due solute release caused by the local methanotrophy.

  13. Flocculation process of fine-grained sediments by the combined effect of salinity and humus in the Changjiang Estuary

    Institute of Scientific and Technical Information of China (English)

    Liu Qizhen; Li Jiufa; Dai Zhijun; Li Daoji

    2007-01-01

    For the great amount of organic compounds and the variation of salinity in the Changjiang Estuary, the study on the flocculation process of fine-grained sediments by the combined effect of salinity and humus in the high-turbid system is of critical significance for the understanding of the mechanism of the formation of the turbidity maximum (TM) .For the great amount of organic compounds and the variation of salinity in the Changjiang Estuary, the study on the flocculation process of fine-grained sediments by the combined effect of salinity and humus in the high-turbid system is of critical significance for the understanding of the mechanism of the formation of the turbidity maximum (TM) .The effects of salinity and humus on the fine-grained sediments have been analyzed through the synthetic study of the aspects of flocculation/coagulation power (F), diameter (D) and zeta potential (Z). And the microcosmic configuration of the flocs has been analyzed by using a scan electron microscope and Fourier Transform Infrared Spectrometry. The results show that: (1) with the increase of salinity, F and D become greater and Z becomes smaller, and with the increase of the concentration of humus, F becomes smaller, but D and Z become greater; (2) the microcosmic configuration of the flocculation shows that humus packs on the fine sediments in the form of salt, and the flocculation model of C-P-OM (C stands for clay; P cations; OM organic materials) can successfully demonstrate the mechanism of the formation of the fine-grained sediments in the high-turbid area of the Changjiang Estuary.

  14. First-order Description of the Mechanical Fracture Behavior of Fine-Grained Surficial Marine Sediments During Gas Bubble Growth

    Science.gov (United States)

    2010-01-01

    10 F04O29 BARRY ET AL.: BUBBLE GROWTH BY FRACTURE P04029 Figure 3. Map of field site. Canard, Nova Scotia, Canada. appears to approximate the...Bottinger. and T. Dahm (2005), Buoyancy-driven fracture ascent: Experiments in layered gelatine. J. Volcano!. Geotherm . Res., 144. 273-285. doi...Journal Article 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE First-order description of the mechanical fracture behavior of fine-grained

  15. Seismic characterization of hydrates in faulted, fine-grained sediments of Krishna-Godavari Basin: Full waveform inversion

    Digital Repository Service at National Institute of Oceanography (India)

    Jaiswal, P.; Dewangan, P.; Ramprasad, T.; Zelt, C.A.

    ; full waveform inversion; P-wave velocity; P-wave attenuation 1. INTRODUCTION Hydrates can play a potentially significant role in climate change (Gu et al., 2011), seafloor stability (Brown et al., 2006), and energy security (Boswell and Collett, 2011... distribution within fine-grained, clay-dominated, and faulted sediments of the Krishna-Godavari (KG) Basin located offshore of eastern continental margin of India (Figure 1). We apply FWI in the frequency domain. The domain choice is driven by a) efficiency...

  16. Estimating suspended sediment using acoustics in a fine-grained riverine system, Kickapoo Creek at Bloomington, Illinois

    Science.gov (United States)

    Manaster, Amanda D.; Domanski, Marian M.; Straub, Timothy D.; Boldt, Justin A.

    2016-08-18

    Acoustic technologies have the potential to be used as a surrogate for measuring suspended-sediment concentration (SSC). This potential was examined in a fine-grained (97-100 percent fines) riverine system in central Illinois by way of installation of an acoustic instrument. Acoustic data were collected continuously over the span of 5.5 years. Acoustic parameters were regressed against SSC data to determine the accuracy of using acoustic technology as a surrogate for measuring SSC in a fine-grained riverine system. The resulting regressions for SSC and sediment acoustic parameters had coefficients of determination ranging from 0.75 to 0.97 for various events and configurations. The overall Nash-Sutcliffe model-fit efficiency was 0.95 for the 132 observed and predicted SSC values determined using the sediment acoustic parameter regressions. The study of using acoustic technologies as a surrogate for measuring SSC in fine-grained riverine systems is ongoing. The results at this site are promising in the realm of surrogate technology.

  17. From bird to sparrow: Learning-induced modulations in fine-grained semantic discrimination.

    Science.gov (United States)

    De Meo, Rosanna; Bourquin, Nathalie M-P; Knebel, Jean-François; Murray, Micah M; Clarke, Stephanie

    2015-09-01

    Recognition of environmental sounds is believed to proceed through discrimination steps from broad to more narrow categories. Very little is known about the neural processes that underlie fine-grained discrimination within narrow categories or about their plasticity in relation to newly acquired expertise. We investigated how the cortical representation of birdsongs is modulated by brief training to recognize individual species. During a 60-minute session, participants learned to recognize a set of birdsongs; they improved significantly their performance for trained (T) but not control species (C), which were counterbalanced across participants. Auditory evoked potentials (AEPs) were recorded during pre- and post-training sessions. Pre vs. post changes in AEPs were significantly different between T and C i) at 206-232ms post stimulus onset within a cluster on the anterior part of the left superior temporal gyrus; ii) at 246-291ms in the left middle frontal gyrus; and iii) 512-545ms in the left middle temporal gyrus as well as bilaterally in the cingulate cortex. All effects were driven by weaker activity for T than C species. Thus, expertise in discriminating T species modulated early stages of semantic processing, during and immediately after the time window that sustains the discrimination between human vs. animal vocalizations. Moreover, the training-induced plasticity is reflected by the sharpening of a left lateralized semantic network, including the anterior part of the temporal convexity and the frontal cortex. Training to identify birdsongs influenced, however, also the processing of C species, but at a much later stage. Correct discrimination of untrained sounds seems to require an additional step which results from lower-level features analysis such as apperception. We therefore suggest that the access to objects within an auditory semantic category is different and depends on subject's level of expertise. More specifically, correct intra

  18. Critical head, thickness of fine-grained deposit, and skeletal elastic storage arrays of the SUB package of the Central Valley Hydrologic Model

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the SUB package arrays for the model grid, critical head, thickness of fine-grained deposits, and skeletal-elastic-storage used in the...

  19. Estimated Altitude of the Top of the Uppermost Unit of Fine-Grained Sediment within the Wood River Valley aquifer system, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is the estimated altitude of the top of the uppermost fine-grained sediment within the Wood River Valley aquifer system. This map was compiled by...

  20. Variational fine-grained data assimilation schemes for atmospheric chemistry transport and transformation models

    Science.gov (United States)

    Penenko, Alexey; Penenko, Vladimir; Tsvetova, Elena

    2015-04-01

    The paper concerns data assimilation problem for an atmospheric chemistry transport and transformation models. Data assimilation is carried out within variation approach on a single time step of the approximated model. A control function is introduced into the model source term (emission rate) to provide flexibility to adjust to data. This function is evaluated as the minimum of the target functional combining control function norm to a misfit between measured and model-simulated analog of data. This provides a flow-dependent and physically-plausible structure of the resulting analysis and reduces the need to calculate model error covariance matrices that are sought within conventional approach to data assimilation. Extension of the atmospheric transport model with a chemical transformations module influences data assimilation algorithms performance. This influence is investigated with numerical experiments for different meteorological conditions altering convection-diffusion processes characteristics, namely strong, medium and low wind conditions. To study the impact of transformation and data assimilation, we compare results for a convection-diffusion model (without data assimilation), convection-diffusion with assimilation, convection-diffusion-reaction (without data assimilation) and convection-diffusion-reaction-assimilation models. Both high dimensionalities of the atmospheric chemistry models and a real-time mode of operation demand for computational efficiency of the algorithms. Computational issues with complicated models can be solved by using a splitting technique. As the result a model is presented as a set of relatively independent simple models equipped with a kind of coupling procedure. With regard to data assimilation two approaches can be identified. In a fine-grained approach data assimilation is carried out on the separate splitting stages [1,2] independently on shared measurement data. The same situation arises when constructing a hybrid model

  1. Development of fine-grain size titanium 6Al–4V alloy sheet material for low temperature superplastic forming

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tuoyang [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan (China); Liu, Yong, E-mail: yonliu@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan (China); Sanders, Daniel G. [Boeing Research and Technology, Seattle, WA (United States); Liu, Bin; Zhang, Weidong; Zhou, Canxu [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan (China)

    2014-07-01

    Fine-grained titanium 6Al–4V alloy, which typically has a grain size of about 1–2 μm, can be made to superplastic form at around 800 °C with special processing. The normal temperature for superplastic forming (SPF) with conventional titanium 6Al–4V sheet material is 900 °C. The lower temperature performance is of interest to the Boeing Company because it can be exploited to achieve significant cost savings in processing by reducing the high-temperature oxidation of the SPF dies, improving the heater rod life for the hot presses, increasing operator safety and replacing the chemical milling operation to remove alpha case contamination with a less intensive nitric hydrofluoric acid etchant (pickle). In this report, room temperature tensile tests and elevated temperature constant strain rate tensile tests of fine-grained Ti–6Al–4V sheets provided by the Baoti Company of Xi'an, China, were conducted according to the test method standards of ASTM-E8 and ASTM-E2448. The relationships among the processing parameters, microstructure and superplastic behavior have been analyzed. The results show that two of the samples produced met the Boeing minimum requirements for low-temperature superplasticity. The successful material was heat-treated at 800 °C subsequent to hot rolling above the beta transus temperature, T{sub β}-(150–250 °C). It was found that the sheet metal microstructure has a significant influence on superplastic formability of the Ti–6Al–4V alloy. Specifically, fine grains, a narrow grain size distribution, low grain aspect ratio and moderate β phase volume fraction can contribute to higher superplastic elongations.

  2. High-strength bolt-forming of fine-grained aluminum alloy 6061 with a continuous hybrid process

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Hun; Hwang, Sun Kwang [National Research Laboratory for Computer Aided Materials Processing, Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Im, Yong-Taek, E-mail: ytim@kaist.ac.kr [National Research Laboratory for Computer Aided Materials Processing, Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Son, Il-Heon; Bae, Chul Min [Wire Rod Research Group, Technical Research Laboratories, POSCO, 1 Goedong-dong, Nam-gu, Pohang, Gyeongbuk 790-785 (Korea, Republic of)

    2012-08-30

    Highlights: Black-Right-Pointing-Pointer Fine-grained AA6061-O was produced by a continuous hybrid process. Black-Right-Pointing-Pointer It consists of rolling, ECAP, and drawing. Black-Right-Pointing-Pointer High-strength bolt was manufactured with the fine-grained AA6061-O. Black-Right-Pointing-Pointer The UTS and micro-hardness of the bolt was increased by 50%. Black-Right-Pointing-Pointer The route C was better in making a uniform micro-hardness distribution in the bolt. - Abstract: It is well known that the development of a continuous manufacturing process to apply severe plastic deformation (SPD) is a major challenge for industrial usages to improve the mechanical properties of the material through grain refinement. In this study, fine-grained AA6061-O wire was manufactured by a two-pass hybrid process consisting of drawing, equal channel angular pressing and rolling in a continuous manner to investigate the effects of processing routes for two different routes, A and C, on the variation of ultimate tensile strength (UTS) and micro-hardness distribution. The UTS value (185 MPa) of the specimen processed by the two-pass hybrid process with route A was higher than that of 171 MPa obtained from the two-pass wire-drawing process and was equivalent to the level of 184 MPa processed by the three-pass wire-drawing process. The average micro-hardness value (Hv 58.0) obtained from the two-pass hybrid process through route C was the highest among all the cases. According to transmission electron microscopy, the original grain was subdivided and elongated owing to deformation during the processes. The specimen processed by the two-pass hybrid process through route C showed smaller deformation bands and had potentially higher angle grain boundaries compared to the specimen processed by the two-pass wire-drawing process. Finally, the high-strength bolt was manufactured using the fine-grained AA6061-O wire prepared by the continuous hybrid process to check its formability

  3. Seismic characterization of hydrates in faulted, fine-grained sediments of Krishna-Godavari basin: Unified imaging

    Digital Repository Service at National Institute of Oceanography (India)

    Jaiswal, P.; Dewangan, P.; Ramprasad, T.; Zelt, C.A.

    ; in coarse-grain sediments, they can reside in pore-spaces, support the sediment framework as load-bearing grains, or bind the sediment grains as cement; in fine-grained sediments, they can create or occupy veins and fractures; on or near the seafloor... of interest to communities investigating climate change (Svensen et al., 2004), energy resources (Collett, 2002), and seafloor stability (Rothwell et al., 1998). When buried below the base of the GHSZ, hydrates become unstable and dissociate from a solid...

  4. Surface Topography of Fine-grained ZrO2 Ceramic by Two-dimensional Ultrasonic Vibration Grinding

    Institute of Scientific and Technical Information of China (English)

    DING Ailing; WU Yan; LIU Yongjiang

    2011-01-01

    The surface quality of fine-grained ZrO2 engineering ceramic were researched using 270# diamond wheel both with and without work-piece two-dimension ultrasonic vibration grinding(WTDUVG).By AFM images,the surface topography and the micro structure of the two-dimensional ultrasonic vibration grinding ceramics were especially analyzed.The experimental results indicate that the surface roughness is related to grinding vibration mode and the material removal mechanism.Surface quality of WTDUVG is superior to that of conventional grinding,and it is easy for two-dimensional ultrasonic vibration grinding that material removal mechanism is ductile mode grinding.

  5. Fine-Grained Parcellation of Brain Connectivity Improves Differentiation of States of Consciousness During Graded Propofol Sedation.

    Science.gov (United States)

    Liu, Xiaolin; Lauer, Kathryn K; Ward, B Douglas; Roberts, Christopher J; Liu, Suyan; Gollapudy, Suneeta; Rohloff, Robert; Gross, William; Xu, Zhan; Chen, Guangyu; Binder, Jeffrey R; Li, Shi-Jiang; Hudetz, Anthony G

    2017-08-01

    Conscious perception relies on interactions between spatially and functionally distinct modules of the brain at various spatiotemporal scales. These interactions are altered by anesthesia, an intervention that leads to fading consciousness. Relatively little is known about brain functional connectivity and its anesthetic modulation at a fine spatial scale. Here, we used functional imaging to examine propofol-induced changes in functional connectivity in brain networks defined at a fine-grained parcellation based on a combination of anatomical and functional features. Fifteen healthy volunteers underwent resting-state functional imaging in wakeful baseline, mild sedation, deep sedation, and recovery of consciousness. Compared with wakeful baseline, propofol produced widespread, dose-dependent functional connectivity changes that scaled with the extent to which consciousness was altered. The dominant changes in connectivity were associated with the frontal lobes. By examining node pairs that demonstrated a trend of functional connectivity change between wakefulness and deep sedation, quadratic discriminant analysis differentiated the states of consciousness in individual participants more accurately at a fine-grained parcellation (e.g., 2000 nodes) than at a coarse-grained parcellation (e.g., 116 anatomical nodes). Our study suggests that defining brain networks at a high granularity may provide a superior imaging-based distinction of the graded effect of anesthesia on consciousness.

  6. Effect of boron addition on formation of a fine-grained microstructure in commercially pure titanium processed by hot compression

    Energy Technology Data Exchange (ETDEWEB)

    Imayev, V.M., E-mail: vimayev@mail.ru; Gaisin, R.A.; Imayev, R.M.

    2015-07-15

    This paper is devoted to comparative investigation of recrystallization behavior during uniaxial hot compression at 600–900 °C of cast commercially pure titanium (CP-Ti) modified with boron and free of boron as well as of CP-Ti in initial wrought condition. Using optical microscopy and EBSD analysis it has been revealed that the boron addition in an amount of 0.2 wt% promoted much more uniform strain development and intensive dynamic recrystallization during hot compression in cast CP-Ti modified with boron as compared with cast CP-Ti free of boron. At the same time, hot compression led to similar fine-grained microstructures in cast CP-Ti modified with boron and wrought CP-Ti. The obtained results suggest that the boron additions to CP-Ti may reduce postcast processing steps and thus reduce the overall cost of produced fine-grained materials out of CP-Ti by means of hot working.

  7. A high-speed multiplexer-based fine-grain pipelined architecture for digital fuzzy logic controllers

    Science.gov (United States)

    Rashidi, Bahram; Masoud Sayedi, Sayed

    2015-12-01

    Design and implementation of a high-speed multiplexer-based fine-grain pipelined architecture for a general digital fuzzy logic controller has been presented. All the operators have been designed at gate level. For the multiplication, a multiplexer-based modified Wallace tree multiplier has been designed, and for the division and addition multiplexer-based non-restoring parallel divider and multiplexer-based Manchester adder have been used, respectively. To further increase the processing speed, fine-grain pipelining technique has been employed. By using this technique, the critical path of the circuit is broken into finer pieces. Based on the proposed architecture, and by using Quartus II 9.1, a sample two-input, one-output digital fuzzy logic controller with eight rules has been successfully synthesised and implemented on Stratix II field programmable gate array. Simulations were carried out using DSP Builder in the MATLAB/Simulink tool at a maximum clock rate of 301.84 MHz.

  8. Synchrotron radiation X-ray diffraction in situ study of fine-grained minerals in shock veins of Suizhou meteorite

    Institute of Scientific and Technical Information of China (English)

    XIE Xiande; SHU Jinfu; CHEN Ming

    2005-01-01

    The synchrotron radiation X-ray diffraction technique developed for in situ study at high pressure and temperature has also been used to investigate microscopic mineral inclusions in ultrahigh-pressure metamorphic rocks and deep-mantle samples. Present study added two more examples of successful utilization of synchrotron radiation X-ray diffraction technique for in situ investigations of fine-grained (0.5―30μm in size) minerals in very thin shock melt veins of the Suizhou meteorite: ( i ) X-ray diffraction measurement of extremely small-sized vein matrix minerals, and (ii) identification of the micron-sized new mineral tuite embedded in the vein matrix. It has been revealed that the fine-grained vein matrix consists of well crystallized garnet, kamacite and troilite, and the powder diffraction pattern consisting of 17 lines with d-values, intensities ( I ), relative intensities (I/Io) and Miller indices, as well as the cell parameters for the new mineral tuite has also been successfully obtained. The result of present investigations has enriched the content of dynamic high-pressure mineralogy and that of Earth's mantle geochemistry.

  9. F2AC: A Lightweight, Fine-Grained, and Flexible Access Control Scheme for File Storage in Mobile Cloud Computing

    Directory of Open Access Journals (Sweden)

    Wei Ren

    2016-01-01

    Full Text Available Current file storage service models for cloud servers assume that users either belong to single layer with different privileges or cannot authorize privileges iteratively. Thus, the access control is not fine-grained and flexible. Besides, most access control methods at cloud servers mainly rely on computationally intensive cryptographic algorithms and, especially, may not be able to support highly dynamic ad hoc groups with addition and removal of group members. In this paper, we propose a scheme called F2AC, which is a lightweight, fine-grained, and flexible access control scheme for file storage in mobile cloud computing. F2AC can not only achieve iterative authorization, authentication with tailored policies, and access control for dynamically changing accessing groups, but also provide access privilege transition and revocation. A new access control model called directed tree with linked leaf model is proposed for further implementations in data structures and algorithms. The extensive analysis is given for justifying the soundness and completeness of F2AC.

  10. Electro-Discharge Fine Truing of Metal-Bonded Fine-Grain Diamond Wheel Based on Real-Time Monitoring

    Institute of Scientific and Technical Information of China (English)

    JIN Weidong; REN Chengzu; HUA Jinhai; WANG Taiyong

    2005-01-01

    A data acquisition system based on LabVIEW is designed and implemented, and electro-discharge(ED) fine truing of metal-bonded fine-grain diamond wheel based on real-time monitoring is researched. Real-time monitoring not only makes efficient impulse specification of ED truing easily obtained, but also is good for timely identifying no-load, avoiding short circuit and arc discharge phenomena and then for obtaining normal machining state. ED fine truing of the fine-grain wheel includes two steps: rough truing for high efficiency and fine truing for high precision. Final ED truing precision and efficiency not only depend on electric process specification, but also is concerned with electrode shape, insulated performance of operating fluid and vertical feed quantity value and frequency. Experiments indicate that ED fine truing based on real-time monitoring can improve the truing precision and efficiency. Average machining efficiency of W10 wheel is about 0.95 μm/min; the final run-out by ED truing is less than 2 μm.

  11. Age, Gender, and Fine-Grained Ethnicity Prediction using Convolutional Neural Networks for the East Asian Face Dataset

    Energy Technology Data Exchange (ETDEWEB)

    Srinivas, Nisha [ORNL; Rose, Derek C [ORNL; Bolme, David S [ORNL; Mahalingam, Gayathri [ORNL; Atwal, Harleen [ORNL; Ricanek, Karl [ORNL

    2017-01-01

    This paper examines the difficulty associated with performing machine-based automatic demographic prediction on a sub-population of Asian faces. We introduce the Wild East Asian Face dataset (WEAFD), a new and unique dataset to the research community. This dataset consists primarily of labeled face images of individuals from East Asian countries, including Vietnam, Burma, Thailand, China, Korea, Japan, Indonesia, and Malaysia. East Asian turk annotators were uniquely used to judge the age and fine grain ethnicity attributes to reduce the impact of the other race effect and improve quality of annotations. We focus on predicting age, gender and fine-grained ethnicity of an individual by providing baseline results with a convolutional neural network (CNN). Finegrained ethnicity prediction refers to predicting ethnicity of an individual by country or sub-region (Chinese, Japanese, Korean, etc.) of the East Asian continent. Performance for two CNN architectures is presented, highlighting the difficulty of these tasks and showcasing potential design considerations that ease network optimization by promoting region based feature extraction.

  12. Autonomous Information Unit for Fine-Grain Data Access Control and Information Protection in a Net-Centric System

    Science.gov (United States)

    Chow, Edward T.; Woo, Simon S.; James, Mark; Paloulian, George K.

    2012-01-01

    As communication and networking technologies advance, networks will become highly complex and heterogeneous, interconnecting different network domains. There is a need to provide user authentication and data protection in order to further facilitate critical mission operations, especially in the tactical and mission-critical net-centric networking environment. The Autonomous Information Unit (AIU) technology was designed to provide the fine-grain data access and user control in a net-centric system-testing environment to meet these objectives. The AIU is a fundamental capability designed to enable fine-grain data access and user control in the cross-domain networking environments, where an AIU is composed of the mission data, metadata, and policy. An AIU provides a mechanism to establish trust among deployed AIUs based on recombining shared secrets, authentication and verify users with a username, X.509 certificate, enclave information, and classification level. AIU achieves data protection through (1) splitting data into multiple information pieces using the Shamir's secret sharing algorithm, (2) encrypting each individual information piece using military-grade AES-256 encryption, and (3) randomizing the position of the encrypted data based on the unbiased and memory efficient in-place Fisher-Yates shuffle method. Therefore, it becomes virtually impossible for attackers to compromise data since attackers need to obtain all distributed information as well as the encryption key and the random seeds to properly arrange the data. In addition, since policy can be associated with data in the AIU, different user access and data control strategies can be included. The AIU technology can greatly enhance information assurance and security management in the bandwidth-limited and ad hoc net-centric environments. In addition, AIU technology can be applicable to general complex network domains and applications where distributed user authentication and data protection are

  13. Microbial colonization and degradation of polyethylene and biodegradable plastic bags in temperate fine-grained organic-rich marine sediments.

    Science.gov (United States)

    Nauendorf, Alice; Krause, Stefan; Bigalke, Nikolaus K; Gorb, Elena V; Gorb, Stanislav N; Haeckel, Matthias; Wahl, Martin; Treude, Tina

    2016-02-15

    To date, the longevity of plastic litter at the sea floor is poorly constrained. The present study compares colonization and biodegradation of plastic bags by aerobic and anaerobic benthic microbes in temperate fine-grained organic-rich marine sediments. Samples of polyethylene and biodegradable plastic carrier bags were incubated in natural oxic and anoxic sediments from Eckernförde Bay (Western Baltic Sea) for 98 days. Analyses included (1) microbial colonization rates on the bags, (2) examination of the surface structure, wettability, and chemistry, and (3) mass loss of the samples during incubation. On average, biodegradable plastic bags were colonized five times higher by aerobic and eight times higher by anaerobic microbes than polyethylene bags. Both types of bags showed no sign of biodegradation during this study. Therefore, marine sediment in temperate coastal zones may represent a long-term sink for plastic litter and also supposedly compostable material.

  14. Temperature dependence of magnetic behaviour in very fine grained, spark plasma sintered NiCuZn ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadi, Behzad; Zehani, Karim; LoBue, Martino; Loyau, Vincent; Mazaleyrat, Frederic [SATIE, ENS Cachan, CNRS, UniverSud 61, avenue du President Wilson, F-94230 Cachan (France)

    2012-04-01

    Recently, using spark plasma sintering technique, a family of very fine grained, fully dense NiCuZn ferrites have been produced, which show constant permeability up to several 10 MHz. These ferrites can be used for filtering purposes in high frequency applications where a wide frequency band is required. In this paper, we study the magnetization processes taking place in these nano grained materials, in the frequency interval of 100 kHz to 5 MHz. Using a fluxmetric hysteresis graph, permeability, loss, and BH loops are measured at different temperatures, from -5 deg. C to 110 deg. C. Results are compared to the behavior of micrometric grain size ferrites, which are commonly used for power electronic and high frequency applications.

  15. On the functional vs. lexical nature of restructuring heads: evidence for a fine-grained classification of restructuring modals

    Directory of Open Access Journals (Sweden)

    Irene Balza

    2012-05-01

    Full Text Available This paper examines in detail the thematic and syntactic properties of a set of (non-restructuring structures in Germanic, Romance and Basque. Based on the comparison of these structures, I propose a fine-grained classification of (non-restructuring constructions that include Functional Restructuring, Semi-Lexical Restructuring, Lexical Restructuring and Non-Restructuring constructions. The four types involve complements of different underlying structures (VPs, vPs or even as large as NegP/TPs. The results of the analysis argue against Cinque’s (2005 hypothesis that all restructuring verbs are exclusively functional, and contradicts Wurmbrand’s (1999 claim that, within the mixed class of restructuring verbs, modals must be raising verbs.

  16. The production of fine grained magnesium alloys through thermomechanical processing for the optimization of microstructural and mechanical properties

    Science.gov (United States)

    Young, John Paul

    The low density and high strength to weight ratio of magnesium alloys makes them ideal candidates to replace many of the heavier steel and aluminum alloys currently used in the automotive and other industries. Although cast magnesium alloys components have a long history of use in the automotive industry, the integration of wrought magnesium alloys components has been hindered by a number of factors. Grain refinement through thermomechanical processing offers a possible solution to many of the inherent problems associated with magnesium alloys. This work explores the development of several thermomechanical processing techniques and investigates their impact on the microstructural and mechanical properties of magnesium alloys. In addition to traditional thermomechanical processing, this work includes the development of new severe plastic deformation techniques for the production of fine grain magnesium plate and pipe and develops a procedure by which the thermal microstructural stability of severely plastically deformed microstructures can be assessed.

  17. GMA-laser Hybrid Welding of High-strength Fine-grain Structural Steel with an Inductive Preheating

    Science.gov (United States)

    Lahdo, Rabi; Seffer, Oliver; Springer, André; Kaierle, Stefan; Overmeyer, Ludger

    The industrial useof GMA-laser hybrid welding has increased in the last 10 years, due to the brilliant quality of the laser beam radiation, and higher laser output powers. GMA-laser hybrid welding processes operate in a common molten pool. The combination of the laser beam and the arc results in improved welding speed, penetration depth, heat affected zone and gap bridgeability. Single-layer, GMA-laser hybrid welding processes have been developed for high-strength fine-grain structural steels with a grade of S690QL and a thickness of 15 mm and 20 mm. In addition, the welding process is assisted by an integrated, inductive preheating process to improve the mechanical properties of the welding seam. By using the determined parameters regarding the energy per unit length, and the preheating temperature, welding seams with high quality can be achieved.

  18. Thermal shock behavior of fine grained W-Y2O3 materials fabricated via two different manufacturing technologies

    Science.gov (United States)

    Zhao, Mingyue; Zhou, Zhangjian; Zhong, Ming; Tan, Jun; Lian, Youyun; Liu, Xiang

    2016-03-01

    Thermal shock resistance of fine grained W-Y2O3 materials fabricated by two different manufacturing technologies (i.e. spark plasma sintering and high temperature sintering in combination with hot rolling deformation) was examined under transient high heat loads below and slightly above the melting threshold of pure tungsten. The tests were performed with the electron beam test facility EMS-60 at Southwestern Institute of Physics, China. The comparison of the thermal shock response in this work showed that the deformed W-Y2O3 performed a superior behavior to spark plasma sintered W-Y2O3 in suppressing the crack formation, melting resistance and recrystallization resistance. The thermo-physical properties and mechanical characterizations necessary for understanding the thermal shock response of these materials were also presented and discussed.

  19. Doping Effects of Rare Earth on Dielectric Properties of Fine-Grained BaTiO3-Based Ceramics

    Institute of Scientific and Technical Information of China (English)

    李玲霞; 郭炜; 吴霞宛; 王洪儒; 张志萍

    2003-01-01

    The doping effects of rare earth oxides Ho2O3 and Er2O3 on dielectric properties of BaTiO3-based ceramics were studied. After adding rare earth elements, grain growth in this system was inhibited and the grain size was reduce devidently which realized the fine-grained effect. In this system, the trivalent oxides Ho2O3 and Er2O3 were added to BaTiO3 ceramics. The rare earth oxides do not enter into inner lattice totally to replace A or B sites. Some of additives can improve dielectric strength by forming nonferroelectric phases, and the rest maintained at grain boundaries controls overgrowth of grains. The dielectric constant at room temperature is increased up to 3000 and the curve of TCC becomes flat. Meanwhile, the dielectric strength Eb becomes higher.

  20. Improvement of NiTi shape memory actuator performance through ultra-fine grained and nanocrystalline microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Frenzel, Jan; Burow, Juri A.; Payton, Eric J.; Rezanka, Stefan; Eggeler, Gunther [Institut fuer Werkstoffe, Ruhr-Universitaet Bochum, Universitaetsstr. 150, 44801 Bochum (Germany)

    2011-04-15

    Ultra-fine grain sizes have been shown to enhance some key mechanical and functional properties of engineering materials, including shape memory alloys. While the effect of ultra-fine and nanocrystalline grain sizes on pseudoelastic shape memory materials is well-appreciated in medical device engineering, the effect of such microstructures on actuators has not been sufficiently characterized. In the present work, it is demonstrated that NiTi spring actuators with ultra-fine grained microstructures can be obtained by conventional wire drawing in combination with heat treatments and that the final grain size can be controlled by varying the final annealing temperature. Annealing at 400 C for 600 s allows for the evolution of microstructures with median grain sizes of about 34 nm, while annealing at 600 C for the same length of time results in median grain sizes of about 5 {mu}m. It is observed that the grain size strongly affects the elementary processes of the martensitic phase transformation. Small austenite grain sizes inhibit twinning accommodation of transformation strains, such that a higher driving force is required to nucleate martensite. This increase in the martensite nucleation barrier decreases the martensite transformation temperatures such that only partial transformation to martensite is possible upon cooling to room temperature. The incomplete martensitic transformation reduces the exploitable actuator stroke; however, a reduction in grain size is shown to improve the functional stability of the material during thermal and thermomechanical cycling by reducing the irreversible effects of dislocation plasticity. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Coarse-grained and fine-grained parallel optimization for real-time en-face OCT imaging

    Science.gov (United States)

    Kapinchev, Konstantin; Bradu, Adrian; Barnes, Frederick; Podoleanu, Adrian

    2016-03-01

    This paper presents parallel optimizations in the en-face (C-scan) optical coherence tomography (OCT) display. Compared with the cross-sectional (B-scan) imagery, the production of en-face images is more computationally demanding, due to the increased size of the data handled by the digital signal processing (DSP) algorithms. A sequential implementation of the DSP leads to a limited number of real-time generated en-face images. There are OCT applications, where simultaneous production of large number of en-face images from multiple depths is required, such as real-time diagnostics and monitoring of surgery and ablation. In sequential computing, this requirement leads to a significant increase of the time to process the data and to generate the images. As a result, the processing time exceeds the acquisition time and the image generation is not in real-time. In these cases, not producing en-face images in real-time makes the OCT system ineffective. Parallel optimization of the DSP algorithms provides a solution to this problem. Coarse-grained central processing unit (CPU) based and fine-grained graphics processing unit (GPU) based parallel implementations of the conventional Fourier domain (CFD) OCT method and the Master-Slave Interferometry (MSI) OCT method are studied. In the coarse-grained CPU implementation, each parallel thread processes the whole OCT frame and generates a single en-face image. The corresponding fine-grained GPU implementation launches one parallel thread for every data point from the OCT frame and thus achieves maximum parallelism. The performance and scalability of the CPU-based and GPU-based parallel approaches are analyzed and compared. The quality and the resolution of the images generated by the CFD method and the MSI method are also discussed and compared.

  2. Evaluation of rock powdering methods to obtain fine-grained samples for CHEMIN, a combined XRD/XRF instrument

    Energy Technology Data Exchange (ETDEWEB)

    Chipera, S. J. (Steve J.); Vaniman, D. T. (David T.); Bish, D. L. (David L.); Sarrazin, P.; Feldman, S.; Blake, D.; Bearman, G. H. (Gregory H.); Bar-Cohen, Yoseph

    2004-01-01

    A miniature XRD/XRD (X-ray diffraction/X-ray fluorescence) instrument, CHEMIN, is currently being developed for definite 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 produces good results even with poorly prepared powder, the quality of the data improves and the time required for data collection is 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 reuslts 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, they 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/XRD instrument such as CHEMIN.

  3. Keypoint Density-Based Region Proposal for Fine-Grained Object Detection and Classification Using Regions with Convolutional Neural Network Features

    Science.gov (United States)

    2015-12-15

    convolution, activation functions, and pooling. For a model trained on classes, the output from the classification layer comprises + 1...Keypoint Density-based Region Proposal for Fine-Grained Object Detection and Classification using Regions with Convolutional Neural Network...Convolutional Neural Networks (CNNs) enable them to outperform conventional techniques on standard object detection and classification tasks, their

  4. Large, high-intensity fire events in Southern California shrublands: Debunking the fine-grain age patch model

    Science.gov (United States)

    Keeley, J.E.; Zedler, P.H.

    2009-01-01

    We evaluate the fine-grain age patch model of fire regimes in southern California shrublands. Proponents contend that the historical condition was characterized by frequent small to moderate size, slow-moving smoldering fires, and that this regime has been disrupted by fire suppression activities that have caused unnatural fuel accumulation and anomalously large and catastrophic wildfires. A review of more than 100 19th-century newspaper reports reveals that large, high-intensity wildfires predate modern fire suppression policy, and extensive newspaper coverage plus first-hand accounts support the conclusion that the 1889 Santiago Canyon Fire was the largest fire in California history. Proponents of the fine-grain age patch model contend that even the very earliest 20th-century fires were the result of fire suppression disrupting natural fuel structure. We tested that hypothesis and found that, within the fire perimeters of two of the largest early fire events in 1919 and 1932, prior fire suppression activities were insufficient to have altered the natural fuel structure. Over the last 130 years there has been no significant change in the incidence of large fires greater than 10000 ha, consistent with the conclusion that fire suppression activities are not the cause of these fire events. Eight megafires (???50 000 ha) are recorded for the region, and half have occurred in the last five years. These burned through a mosaic of age classes, which raises doubts that accumulation of old age classes explains these events. Extreme drought is a plausible explanation for this recent rash of such events, and it is hypothesized that these are due to droughts that led to increased dead fine fuels that promoted the incidence of firebrands and spot fires. A major shortcoming of the fine-grain age patch model is that it requires age-dependent flammability of shrubland fuels, but seral stage chaparral is dominated by short-lived species that create a dense surface layer of fine

  5. Shear Localization and its Related Microstructure Mechanism in a Fine-Grain-Sized Near-Beta Ti Alloy

    Science.gov (United States)

    Wang, Bingfeng; Sun, Jieying; Hahn, Eric Nicholas; Wang, Xiaoyan

    2015-01-01

    Shear localization is an important deformation and failure mechanism for the high strength near beta fine-grain-sized titanium alloy used in aircraft's gear at high rate deformation. Hat-shaped specimens are used to induce the formation of an adiabatic shear band under controlled shock-loading tests. Unstable shear deformation of the alloy emerges after the true flow stress reaches 1147 MPa, the first vibration peak during the split Hopkinson pressure bar testing, and the whole process lasts about 68 μs. The microstructures within the shear band in the alloy are investigated by means of light microscopy, scanning electron microscopy, and transmission electron microscopy. The results show that the grains in the boundary of the shear band are highly elongated along the shear direction, and the core of the shear band consists of ultrafine-equiaxed grains with diameters 0.1-0.3 μm, low dislocation density, and no observed phase transformation. The rotational dynamic recrystallization is used to explain the microstructural evolution mechanism in the shear band. Kinetic calculations indicate that the recrystallized ultrafine grains are formed during the deformation and do not undergo significant growth by grain boundary migration after deformation.

  6. Thin-layer heap bioleaching of copper flotation tailings containing high levels of fine grains and microbial community succession analysis

    Science.gov (United States)

    Hao, Xiao-dong; Liang, Yi-li; Yin, Hua-qun; Liu, Hong-wei; Zeng, Wei-min; Liu, Xue-duan

    2017-04-01

    Thin-layer heap bioleaching of copper flotation tailings containing high levels of fine grains was carried out by mixed cultures on a small scale over a period of 210 d. Lump ores as a framework were loaded at the bottom of the ore heap. The overall copper leaching rates of tailings and lump ores were 57.10wt% and 65.52wt%, respectively. The dynamic shifts of microbial community structures about attached microorganisms were determined using the Illumina MiSeq sequencing platform based on 16S rRNA amplification strategy. The results indicated that chemolithotrophic genera Acidithiobacillus and Leptospirillum were always detected and dominated the microbial community in the initial and middle stages of the heap bioleaching process; both genera might be responsible for improving the copper extraction. However, Thermogymnomonas and Ferroplasma increased gradually in the final stage. Moreover, the effects of various physicochemical parameters and microbial community shifts on the leaching efficiency were further investigated and these associations provided some important clues for facilitating the effective application of bioleaching.

  7. Surface morphology changes and deuterium retention in Toughened, Fine-grained Recrystallized Tungsten under high-flux irradiation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Oya, M., E-mail: ohya@st.eie.eng.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Lee, H.T.; Ueda, Y. [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Kurishita, H. [Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Oyaidzu, M.; Hayashi, T. [Fusion Research and Development Directorate, International Fusion Energy Research Center, Japan Atomic Energy Agency, Rokkasho-mura, Aomori 039-3212 (Japan); Yoshida, N. [Research Institute for Applied Mechanics, Kyushu University, Fukuoka (Japan); Morgan, T.W.; De Temmerman, G. [FOM Institute DIFFER Dutch Institute for Fundamental Energy Research, Nieuwegein 3439 MN (Netherlands)

    2015-08-15

    Surface morphology changes and deuterium (D) retention in Toughened, Fine-Grained Recrystallized Tungsten (TFGR W) with TaC dispersoids (W-TaC) and pure tungsten exposed to D plasmas to a fluence of 10{sup 26} D/m{sup 2} s were studied as a function of the D ion flux (10{sup 22}–10{sup 24} D/m{sup 2} s). As the flux increased from 10{sup 22} D/m{sup 2} s to 10{sup 24} D/m{sup 2} s, the numbers of blisters increased for both materials. However, smaller blisters were observed on W-TaC compared to pure W. In W-TaC, cracks beneath the surface along grain boundaries were observed, which were comparable to the blister sizes. The reason for the smaller blister sizes may arise from smaller grain sizes of W-TaC. In addition, reduction of the D retention in W-TaC was observed for higher flux exposures. D depth profiles indicate this reduction arises due to decrease in trapping in the bulk.

  8. Intelligibility of normal speech I: Global and fine-grained acoustic-phonetic talker characteristics1,2

    Science.gov (United States)

    Bradlow, Ann R.; Torretta, Gina M.; Pisoni, David B.

    2011-01-01

    This study used a multi-talker database containing intelligibility scores for 2000 sentences (20 talkers, 100 sentences), to identify talker-related correlates of speech intelligibility. We first investigated “global” talker characteristics (e.g., gender, F0 and speaking rate). Findings showed female talkers to be more intelligible as a group than male talkers. Additionally, we found a tendency for F0 range to correlate positively with higher speech intelligibility scores. However, F0 mean and speaking rate did not correlate with intelligibility. We then examined several fine-grained acoustic-phonetic talker-characteristics as correlates of overall intelligibility. We found that talkers with larger vowel spaces were generally more intelligible than talkers with reduced spaces. In investigating two cases of consistent listener errors (segment deletion and syllable affiliation), we found that these perceptual errors could be traced directly to detailed timing characteristics in the speech signal. Results suggest that a substantial portion of variability in normal speech intelligibility is traceable to specific acoustic-phonetic characteristics of the talker. Knowledge about these factors may be valuable for improving speech synthesis and recognition strategies, and for special populations (e.g., the hearing-impaired and second-language learners) who are particularly sensitive to intelligibility differences among talkers. PMID:21461127

  9. Ultra-fine grained microstructure of metastable beta Ti-15Mo alloy and its effects on the phase transformations

    Science.gov (United States)

    Václavová, K.; Stráský, J.; Zháňal, P.; Veselý, J.; Polyakova, V.; Semenova, I.; Janeček, M.

    2017-05-01

    Processing of metastable titanium alloys by severe plastic deformation provides an opportunity to achieve exceptional grain refinement, to enhance the strength and to affect phase transformations occurring during thermal treatment. The main aim of this study is to investigate the microstructure of ultra-fine grained (UFG) material and effect of microstructural changes on phase transformations in metastable β-Ti alloy Ti-15Mo. Metastable β-Ti alloys are currently the most studied Ti-based materials with prospective use in medicine. Ti-15Mo alloy after solution treatment contains metastable β-phase. Metastable ω-phase and stable α-phase particles are formed upon annealing,. Solution treated Ti-15Mo alloy was deformed by high pressure torsion (HPT) at room temperature. Severely deformed structure after HPT with grain size of ~200 nm was studied by transmission electron microscopy. In-situ electrical resistance measurements showed significant changes in undergoing phase transformations when compared to coarse-grained (CG) material. Scanning electron microscopy revealed heterogeneous precipitation of α-particles at grain boundaries (GB). Due to the high density of GBs in UFG structure, these precipitates are very fine and equiaxed. The study demonstrates that SPD is capable of enhancing mechanical properties due to grain refinement and via affecting precipitation processes in metastable β-Ti alloys.

  10. Oxygen Isotopic Composition of Coarse- and Fine-grained Material from Comet 81P/Wild 2

    CERN Document Server

    Ogliore, Ryan C; Huss, Gary R; Westphal, Andrew J; Gainsforth, Zack; Butterworth, Anna L

    2015-01-01

    Individual particles from comet 81P/Wild 2 collected by NASA's Stardust mission vary in size from small sub-$\\mu$m fragments found in the walls of the aerogel tracks, to large fragments up to tens of $\\mu$m in size found towards the termini of tracks. The comet, in an orbit beyond Neptune since its formation, retains an intact a record of early-Solar-System processes that was compromised in asteroidal samples by heating and aqueous alteration. We measured the O isotopic composition of seven Stardust fragments larger than $\\sim$2 $\\mu$m extracted from five different Stardust aerogel tracks, and 63 particles smaller than $\\sim$2 $\\mu$m from the wall of a Stardust track. The larger particles show a relatively narrow range of O isotopic compositions that is consistent with $^{16}$O-poor phases commonly seen in meteorites. Many of the larger Stardust fragments studied so far have chondrule-like mineralogy which is consistent with formation in the inner Solar System. The fine-grained material shows a very broad ran...

  11. Modelling of interfacial transition zone effect on resistance to crack propagation in fine-grained cement-based composites

    Directory of Open Access Journals (Sweden)

    H. Šimonová

    2017-07-01

    Full Text Available In this paper, the attention is paid to investigation of the importance of the interfacial transition zone (ITZ in selected fine-grained cement-based composites for the global fracture behaviour. This is a region of cement paste around the aggregate particles which specific features could have significant impact on the final behaviour of cement composites with a crack tip nearby this interface under applied tension. The aim of this work is to show the basic interface microstructure by scanning electron microscopy (SEM done by MIRA3 TESCAN and to analyse the behaviour of such composite by numerical modelling. Numerical studies assume two different ITZ thicknesses taken from SEM analysis. A simplified cracked geometry (consisting of three phases – matrix, ITZ, and aggregate is modelled by means of the finite element method with a crack terminating at the matrix–ITZ interface. ITZ’s modulus of elasticity is taken from generalized self-consistent scheme. A few conclusions are discussed based on comparison of the average values of the opening stress ahead of the crack tip with their critical values. The analyses dealing with the effect of ITZ’s properties on the stress distribution should contribute to better description of toughening mechanisms in silicate-based composites.

  12. Fabrication, tribological and corrosion behaviors of ultra-fine grained Co-28Cr-6Mo alloy for biomedical applications.

    Science.gov (United States)

    Ren, Fuzeng; Zhu, Weiwei; Chu, Kangjie

    2016-07-01

    Nickel and carbides free Co-28Cr-6Mo alloy was fabricated by combination of mechanical alloying and warm pressing. The microstructure, mechanical properties, pin-on-disk dry sliding wear and corrosion behavior in simulated physiological solution were investigated. The produced Co-28Cr-6Mo alloy has elongated ultra-fine grained (UFG) structure of ε-phase with average grain size of 600nm in length and 150nm in thickness. The hardness and modulus were determined to be 8.87±0.56GPa and 198.27±7.02GPa, respectively. The coefficient of friction upon dry sliding against alumina is pretty close to that of the forged Co-29Cr-6Mo alloy. The initial ε-phase and UFG microstructure contribute to reduce the depth of severe plastic deformation region during wear and enable the alloy with excellent wear resistance. The corrosion potential of such UFG Co-Cr-Mo alloy has more positive corrosion potential and much lower corrosion current density than those of ASTM alloy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Key parameters for low-grade fine-grained iron ore valorization: lower environmental impact through reduced waste.

    Science.gov (United States)

    Wagner, Christiane; Orberger, Beate; Tudryn, Alina; Baptiste, Benoît; Wirth, Richard; Morgan, Rachel; Miska, Serge

    2016-04-01

    In low-grade banded iron formations (BIFs), a large part of the iron is related to micro- and nano- metric iron-bearing inclusions within quartz and/or carbonates, mainly dolomite (~ 20 to 50 μm). Low-grade fine grained iron ore present two types of environmental risks: a) they are often stocked as tailings. For example, the recent disaster (5th of November 2015) in the Minas Gerais district, Brazil, was caused by the collapse of the Fundão tailings dam at an open cast mine; b) during beneficiation significant amounts of dust are generated also leading to metal loss. A laminated BIF studied from a drill core at Àguas Claras Mine, Quadrilátero Ferrífero, Brazil, contains 26.71 wt. % total iron, 0.2 wt. % SiO2, 0.32 wt.% MnO, 15.46 wt. % MgO, 22.32 wt.% CaO, 0.09 wt. % P2O5, risk factors.

  14. A Fine-Grained Visible Light Communication Position Detection System Embedded in One-Colored Light Using DMD Projector

    Directory of Open Access Journals (Sweden)

    Motoi Kodama

    2017-01-01

    Full Text Available When we consider the Internet of Things (IoT society that all of the people and things are connected by the Internet and with each other and they can use the variety of services and applications, the development of sensing and communication technology is very important. As one of its key technologies, the visible light communication (VLC has attracted attention in the point of ubiquity. In this paper, we propose a fine-grained VLC position detection system embedded in one-colored light using Digital Micromirror Device (DMD projector for new location services in millimeters and report its concept and fundamental experiment using our prototype of the receiver module with Linux single-board computer, Raspberry Pi. In addition, we mention the future application using our system in a clothes shop. Our experimental results show that our system has high accuracy in millimeters and the potential to be more convenient in the future’s location services using the VLC with the DMD projector. There was no trial to use a DMD projector as the illumination until now, but our study shows that the DMD projector has an availability of special modulated VLC illumination type beacon in the IoT age.

  15. Surface modifications on toughened, fine-grained, recrystallized tungsten with repetitive ELM-like pulsed plasma irradiation

    Science.gov (United States)

    Kikuchi, Y.; Sakuma, I.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M.; Ueda, Y.; Kurishita, H.

    2015-08-01

    Surface modifications of toughened, fine-grained, recrystallized tungsten (TFGR W) materials with 1.1 wt.% TiC and 3.3 wt.% TaC dispersoids due to repetitive ELM-like pulsed (∼0.15 ms) helium plasma irradiation have been investigated by using a magnetized coaxial plasma gun. No surface cracking at the center part of the TFGR W samples exposed to 20 plasma pulses of ∼0.3 MJ m-2 was observed. The suppression of surface crack formation due to the increase of the grain boundary strength by addition of TiC and TaC dispersoids was confirmed in comparison with a pure W material. On the other hand, surface cracks and small pits appeared at the edge part of the TFGR W sample after the pulsed plasma irradiation. Erosion of the TiC and TaC dispersoids due to the pulsed plasma irradiation could cause the small pits on the surface, resulting in the surface crack formation.

  16. Surface modifications on toughened, fine-grained, recrystallized tungsten with repetitive ELM-like pulsed plasma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Y., E-mail: ykikuchi@eng.u-hyogo.ac.jp [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, 671-2280 Hyogo (Japan); Sakuma, I.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M. [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, 671-2280 Hyogo (Japan); Ueda, Y. [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kurishita, H. [Institute for Materials Research, Tohoku University, Ibaraki 311-1313 (Japan)

    2015-08-15

    Surface modifications of toughened, fine-grained, recrystallized tungsten (TFGR W) materials with 1.1 wt.% TiC and 3.3 wt.% TaC dispersoids due to repetitive ELM-like pulsed (∼0.15 ms) helium plasma irradiation have been investigated by using a magnetized coaxial plasma gun. No surface cracking at the center part of the TFGR W samples exposed to 20 plasma pulses of ∼0.3 MJ m{sup −2} was observed. The suppression of surface crack formation due to the increase of the grain boundary strength by addition of TiC and TaC dispersoids was confirmed in comparison with a pure W material. On the other hand, surface cracks and small pits appeared at the edge part of the TFGR W sample after the pulsed plasma irradiation. Erosion of the TiC and TaC dispersoids due to the pulsed plasma irradiation could cause the small pits on the surface, resulting in the surface crack formation.

  17. AraPPISite: a database of fine-grained protein-protein interaction site annotations for Arabidopsis thaliana.

    Science.gov (United States)

    Li, Hong; Yang, Shiping; Wang, Chuan; Zhou, Yuan; Zhang, Ziding

    2016-09-01

    Knowledge about protein interaction sites provides detailed information of protein-protein interactions (PPIs). To date, nearly 20,000 of PPIs from Arabidopsis thaliana have been identified. Nevertheless, the interaction site information has been largely missed by previously published PPI databases. Here, AraPPISite, a database that presents fine-grained interaction details for A. thaliana PPIs is established. First, the experimentally determined 3D structures of 27 A. thaliana PPIs are collected from the Protein Data Bank database and the predicted 3D structures of 3023 A. thaliana PPIs are modeled by using two well-established template-based docking methods. For each experimental/predicted complex structure, AraPPISite not only provides an interactive user interface for browsing interaction sites, but also lists detailed evolutionary and physicochemical properties of these sites. Second, AraPPISite assigns domain-domain interactions or domain-motif interactions to 4286 PPIs whose 3D structures cannot be modeled. In this case, users can easily query protein interaction regions at the sequence level. AraPPISite is a free and user-friendly database, which does not require user registration or any configuration on local machines. We anticipate AraPPISite can serve as a helpful database resource for the users with less experience in structural biology or protein bioinformatics to probe the details of PPIs, and thus accelerate the studies of plant genetics and functional genomics. AraPPISite is available at http://systbio.cau.edu.cn/arappisite/index.html .

  18. Parallel reduction to condensed forms for symmetric eigenvalue problems using aggregated fine-grained and memory-aware kernels

    KAUST Repository

    Haidar, Azzam

    2011-01-01

    This paper introduces a novel implementation in reducing a symmetric dense matrix to tridiagonal form, which is the preprocessing step toward solving symmetric eigenvalue problems. Based on tile algorithms, the reduction follows a two-stage approach, where the tile matrix is first reduced to symmetric band form prior to the final condensed structure. The challenging trade-off between algorithmic performance and task granularity has been tackled through a grouping technique, which consists of aggregating fine-grained and memory-aware computational tasks during both stages, while sustaining the application\\'s overall high performance. A dynamic runtime environment system then schedules the different tasks in an out-of-order fashion. The performance for the tridiagonal reduction reported in this paper is unprecedented. Our implementation results in up to 50-fold and 12-fold improvement (130 Gflop/s) compared to the equivalent routines from LAPACK V3.2 and Intel MKL V10.3, respectively, on an eight socket hexa-core AMD Opteron multicore shared-memory system with a matrix size of 24000×24000. Copyright 2011 ACM.

  19. Analysis of syntactic and semantic features for fine-grained event-spatial understanding in outbreak news reports

    Directory of Open Access Journals (Sweden)

    Chanlekha Hutchatai

    2010-03-01

    Full Text Available Abstract Background Previous studies have suggested that epidemiological reasoning needs a fine-grained modelling of events, especially their spatial and temporal attributes. While the temporal analysis of events has been intensively studied, far less attention has been paid to their spatial analysis. This article aims at filling the gap concerning automatic event-spatial attribute analysis in order to support health surveillance and epidemiological reasoning. Results In this work, we propose a methodology that provides a detailed analysis on each event reported in news articles to recover the most specific locations where it occurs. Various features for recognizing spatial attributes of the events were studied and incorporated into the models which were trained by several machine learning techniques. The best performance for spatial attribute recognition is very promising; 85.9% F-score (86.75% precision/85.1% recall. Conclusions We extended our work on event-spatial attribute recognition by focusing on machine learning techniques, which are CRF, SVM, and Decision tree. Our approach avoided the costly development of an external knowledge base by employing the feature sources that can be acquired locally from the analyzed document. The results showed that the CRF model performed the best. Our study indicated that the nearest location and previous event location are the most important features for the CRF and SVM model, while the location extracted from the verb's subject is the most important to the Decision tree model.

  20. Analysis of syntactic and semantic features for fine-grained event-spatial understanding in outbreak news reports.

    Science.gov (United States)

    Chanlekha, Hutchatai; Collier, Nigel

    2010-03-31

    Previous studies have suggested that epidemiological reasoning needs a fine-grained modelling of events, especially their spatial and temporal attributes. While the temporal analysis of events has been intensively studied, far less attention has been paid to their spatial analysis. This article aims at filling the gap concerning automatic event-spatial attribute analysis in order to support health surveillance and epidemiological reasoning. In this work, we propose a methodology that provides a detailed analysis on each event reported in news articles to recover the most specific locations where it occurs. Various features for recognizing spatial attributes of the events were studied and incorporated into the models which were trained by several machine learning techniques. The best performance for spatial attribute recognition is very promising; 85.9% F-score (86.75% precision/85.1% recall). We extended our work on event-spatial attribute recognition by focusing on machine learning techniques, which are CRF, SVM, and Decision tree. Our approach avoided the costly development of an external knowledge base by employing the feature sources that can be acquired locally from the analyzed document. The results showed that the CRF model performed the best. Our study indicated that the nearest location and previous event location are the most important features for the CRF and SVM model, while the location extracted from the verb's subject is the most important to the Decision tree model.

  1. Composition dependence on the martensitic structures of the Mn-rich NiMnGa alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Chengbao; Muhammad, Yousaf; Deng Lifeng; Wu Wei; Xu Huibin

    2004-05-17

    The Mn-rich Ni{sub 50}Mn{sub 25+x}Ga{sub 25-x} (x=0-5) alloys were developed to investigate the structural transitions and magnetic properties. Structural transitions from austenite to 5M, 7M, and non-modulated martensite were observed with the increase of Mn content. The lattice parameter a elongates, as where b and c contract, and the unit cell volume reduces with increasing Mn content. The martensitic transformation start temperatures M{sub s} increase monotonically from 10.7 deg. C for x=2 to 102.7 deg. C for x=5. The saturation magnetization was measured at 5 K, where all the samples exhibit a martensitic structure. The average magnetic moments per Mn atom vary from 4.38 {mu}{sub B} to 2.93 {mu}{sub B} for x=0 to x=5. The negative effect of excess Mn atoms changes from -3.00 {mu}{sub B} for x=2 to -7.25 {mu}{sub B} for x=5. The excess Mn atoms modify the electronic structures of the unsubstituted Mn atoms, resulting in the sharp decrease of the magnetic moments of the unsubstituted Mn atoms with increasing Mn content. Structural incommensurability was observed with 7M for powder and non-modulated for bulk samper in a specific range of compositions and proved to be reversible when performing martensitic transformation. The 7M and non-modulated martensites Ni{sub 50}Mn{sub 30}Ga{sub 20} possess similar saturation magnetizations and Curie temperatures. The non-modulated martensite was estimated to have a lower free energy than 7M, and should be more stable for a reverse martensitic transformation, leading to a higher austenite start temperature A{sub s}, which is consistent with the experimental result.

  2. A less expensive NiMnGa based Heusler alloy for magnetic refrigeration

    OpenAIRE

    Mejia, CS; Gomes, AM; de Oliveira, LAS

    2012-01-01

    We present a study of the substitution of Mn by Cu on the compound Ni2Mn1-xCuxGa0.9Al0.1, showing that the substitution of a small amount of Al on the Ga site does not affect the magnetic and magnetocaloric potential compared to Ni-2(Mn,Cu)Ga alloy. The samples were prepared with 10% substitution of Al and with Cu concentrations of x = 0.0, 0.2, and 0.3. Magnetization measurements as a function of temperature performed from 10 to 400 K, with an applied field of 0.02 T showed a ferromagnetic s...

  3. Large magnetic-field-induced strains in rare earth polycrystalline Ni-Mn-Ga

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zengqi; WU Shuangxia; WANG Fangshu; WANG Qiang; JIANG Liping; WANG Xinlin

    2004-01-01

    The magnetic-field-induced strains (MFIS) of polycrystalline Ni50Mn29Ga21 alloys containing Tb were studied. A large MFIS of - 1.10% was obtained under compressive prestress conditions. The addition of Tb can fine the crystal grains, enhance the bending strength obviously, and make MFIS increase further, indicating that a moderate amount of Tb does not hinder twin boundary motion and it conversely makes the material more practical.

  4. Ni-Mn-Ga Single Crystal Exhibiting Multiple Magnetic Shape Memory Effects

    Science.gov (United States)

    Heczko, Oleg; Veřtát, Petr; Vronka, Marek; Kopecky, Vít; Perevertov, Oleksiy

    2016-09-01

    Both magnetically induced phase transformation and magnetically induced reorientation (MIR) effects were observed in one Ni50Mn28Ga22 single crystal sample by direct measurement of the magnetic field-induced strain. We investigated various twinning microstructures ranged from single twin interface to fine twinning and crossing twins to evaluate what controls the apparent twinning stress crucial for MIR. The main challenges for the applications of these effects are outlined.

  5. Influence of martensitic transformation on the magnetic transition in Ni-Mn-Ga

    Science.gov (United States)

    Kokorin, V. V.; Konoplyuk, S. M.; Dalinger, A.; Maier, H. J.

    2017-06-01

    The magnetic transition with a temperature hysteresis of about 7 K was observed in the martensitic phase of Ni51.9Mn27Ga211. The measurements of AC magnetic susceptibility in constant magnetic fields up to 570 kA/m have proved its magnetic origin. The transport and caloric measurements were used to gain better understanding of the nature of this phenomenon. The variation of the martensite lattice parameters with temperature is suggested to account for the hysteresis of the magnetic transition.

  6. Structural, microstructural and magnetocaloric investigations in high-energy ball milled NiMnGa powders

    Science.gov (United States)

    de Santanna, Y. V. B.; de Melo, M. A. C.; Santos, I. A.; Coelho, A. A.; Gama, S.; Cótica, L. F.

    2008-11-01

    In this paper, structural, microstrucutural and magnetocaloric properties of Ni 2.18Mn 0.82Ga alloys submitted to high-energy ball milling are reported. A 7-layered orthorhombic martensitic ( Pnnm) phase was detected in post-milling annealed samples, which reached a microstrucuture composed predominantly by nanograins. The magnetocaloric effect is strongly weakened in comparison with as-cast samples of similar composition. This effect can be attributed to the absence of the mesoscale twin-related martensitic variants in the nanostructurated powders. However, post-milled samples annealed at 1123 K for 4 h present relative cooling powers as high as those observed for manganites. Therefore, these materials can be considered as potential candidates for use as regenerators in prototypal magnetic refrigerators.

  7. Recent breakthrough development of the magnetic shape memory effect in Ni Mn Ga alloys

    Science.gov (United States)

    Söderberg, O.; Ge, Y.; Sozinov, A.; Hannula, S.-P.; Lindroos, V. K.

    2005-10-01

    Magnetic shape memory (MSM) alloys or ferromagnetic shape memory alloy (FSMA) materials discovered by Ullakko et al (1996 Appl. Phys. Lett. 69 1966-8) have received increasing interest, since they can produce a large strain with rather high frequencies without a change in the external temperature. These materials have potential for actuator and sensor applications. MSM materials exhibit giant magnetic field induced strain (MFIS) based on the rearrangements of the crystallographic domains (twin variants). The magnetization energy of the material is lowered when such twin variants that have the easy axis of magnetization along the field start to grow due to twin boundary motion. Currently, the best working MSM materials are the near-stoichiometric Ni2MnGa Heusler alloys in which the properties are highly composition dependent. Their modulated martensitic structures, 5M and 7M, show 6% or 10% response respectively in a magnetic field less than 800 kA m-1. The MSM service temperature of the 5M alloys is between 150 and 333 K, and the optimal frequency region is up to 500 Hz. The fatigue life of the MSM elements has been shown to be at least 50 × 106 shape change cycles. This paper reviews the research work carried out at Helsinki University of Technology on MSM materials since 1998.

  8. Neutron diffraction studies of magnetic-shape memory Ni-Mn-Ga single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Heczko, Oleg [Laboratory of Materials Science, Helsinki University of Technology, Vuorimiehentie 2A, P.O. Box 6200, FI-02015 TKK, Espoo (Finland)]. E-mail: oleg.heczko@tkk.fi; Prokes, Karel [Berlin Neutron Scattering Center, Hahn-Meitner-Institut Berlin, Glienicker Strasse 100, D-14109 Berlin (Wannsee) (Germany); Hannula, Simo-Pekka [Laboratory of Materials Science, Helsinki University of Technology, Vuorimiehentie 2A, P.O. Box 6200, FI-02015 TKK, Espoo (Finland)

    2007-09-15

    Neutron diffraction of single crystal of the typical example of magnetic-shape memory (MSM) alloy Ni{sub 49.7}Mn{sub 29.3}Ga{sub 21} was carried out with a 2D position sensitive detector. The quality and inhomogeneity of the single crystal and martensite variant distribution was studied using {omega}-scan of selected nuclear Bragg reflections. The neutron diffraction reveals split of the (2 0 0) reflection of major martensite variant and large structural inhomogeneities in martensite phase. Using measurement in reciprocal space, we recorded a set of reflections that appear due to structural modulation (5 M) of the martensite, however, the set seems to be incomplete with missing or very weak reflections of second order compared with X-ray diffraction. The line of the magnetic reflection arising from the supposed antiferromagnetic ordering of the excess Mn atoms was very weak and it is difficult to discern from the background.

  9. Neutron diffraction studies of magnetic-shape memory Ni-Mn-Ga single crystal

    Science.gov (United States)

    Heczko, Oleg; Prokes, Karel; Hannula, Simo-Pekka

    2007-09-01

    Neutron diffraction of single crystal of the typical example of magnetic-shape memory (MSM) alloy Ni 49.7Mn 29.3Ga 21 was carried out with a 2D position sensitive detector. The quality and inhomogeneity of the single crystal and martensite variant distribution was studied using ω-scan of selected nuclear Bragg reflections. The neutron diffraction reveals split of the (2 0 0) reflection of major martensite variant and large structural inhomogeneities in martensite phase. Using measurement in reciprocal space, we recorded a set of reflections that appear due to structural modulation (5 M) of the martensite, however, the set seems to be incomplete with missing or very weak reflections of second order compared with X-ray diffraction. The line of the magnetic reflection arising from the supposed antiferromagnetic ordering of the excess Mn atoms was very weak and it is difficult to discern from the background.

  10. Magnetic indication of the stress-induced martensitic transformation in ferromagnetic Ni-Mn-Ga alloy

    Energy Technology Data Exchange (ETDEWEB)

    Heczko, O. [Laboratory of Materials Science, Helsinki University of Technology, Vuorimiehentie 2A, P.O. Box 6200, FIN-02015 TKK, Espoo (Finland); L' vov, V.A. [Radiophysics Department, Taras Shevchenko University, Glushkov str. 2, build. 5, 03022 Kiev (Ukraine); Straka, L. [Laboratory of Biomedical Engineering, Helsinki University of Technology, Rakentajanaukio 2C, P.O. Box 2200, FIN-02015, Espoo (Finland)]. E-mail: ladislav.straka@hut.fi; Hannula, S.-P. [Laboratory of Materials Science, Helsinki University of Technology, Vuorimiehentie 2A, P.O. Box 6200, FIN-02015 TKK, Espoo (Finland)

    2006-07-15

    A quantitative study of the stress-induced martensitic transformation in Ni{sub 49.7}Mn{sub 29.1}Ga{sub 21.2} magnetic shape memory alloy has been carried out in two different ways: the first way is based on the measurements of saturation magnetization under variable mechanical stress and the second one is founded on the quantitative theoretical treatment of experimental stress-strain loops. A functional dependence between the volume fraction of transformed martensite and applied stress has been determined from both magnetization and strain values. A quantitative agreement between the functions determined in two different ways has been observed, and hence, the effectiveness of the magnetic indication of the stress-induced martensitic transformations has been proved. This method can be used to monitor stress-induced transformations in martensitic films, needles and small specimens.

  11. Magnetic indication of the stress-induced martensitic transformation in ferromagnetic Ni Mn Ga alloy

    Science.gov (United States)

    Heczko, O.; L'vov, V. A.; Straka, L.; Hannula, S.-P.

    2006-07-01

    A quantitative study of the stress-induced martensitic transformation in Ni 49.7Mn 29.1Ga 21.2 magnetic shape memory alloy has been carried out in two different ways: the first way is based on the measurements of saturation magnetization under variable mechanical stress and the second one is founded on the quantitative theoretical treatment of experimental stress-strain loops. A functional dependence between the volume fraction of transformed martensite and applied stress has been determined from both magnetization and strain values. A quantitative agreement between the functions determined in two different ways has been observed, and hence, the effectiveness of the magnetic indication of the stress-induced martensitic transformations has been proved. This method can be used to monitor stress-induced transformations in martensitic films, needles and small specimens.

  12. SPAR: a random forest-based predictor for self-interacting proteins with fine-grained domain information.

    Science.gov (United States)

    Liu, Xuhan; Yang, Shiping; Li, Chen; Zhang, Ziding; Song, Jiangning

    2016-07-01

    Protein self-interaction, i.e. the interaction between two or more identical proteins expressed by one gene, plays an important role in the regulation of cellular functions. Considering the limitations of experimental self-interaction identification, it is necessary to design specific bioinformatics tools for self-interacting protein (SIP) prediction from protein sequence information. In this study, we proposed an improved computational approach for SIP prediction, termed SPAR (Self-interacting Protein Analysis serveR). Firstly, we developed an improved encoding scheme named critical residues substitution (CRS), in which the fine-grained domain-domain interaction information was taken into account. Then, by employing the Random Forest algorithm, the performance of CRS was evaluated and compared with several other encoding schemes commonly used for sequence-based protein-protein interaction prediction. Through the tenfold cross-validation tests on a balanced training dataset, CRS performed the best, with the average accuracy up to 72.01 %. We further integrated CRS with other encoding schemes and identified the most important features using the mRMR (the minimum redundancy maximum relevance) feature selection method. Our SPAR model with selected features achieved an average accuracy of 92.09 % on the human-independent test set (the ratio of positives to negatives was about 1:11). Besides, we also evaluated the performance of SPAR on an independent yeast test set (the ratio of positives to negatives was about 1:8) and obtained an average accuracy of 76.96 %. The results demonstrate that SPAR is capable of achieving a reasonable performance in cross-species application. The SPAR server is freely available for academic use at http://systbio.cau.edu.cn/zzdlab/spar/ .

  13. Improving the Fatigue Performance of the Welded Joints of Ultra-Fine Grain Steel by Ultrasonic Peening

    Institute of Scientific and Technical Information of China (English)

    王东坡; 王婷; 霍立兴; 张玉凤

    2004-01-01

    Contrast tests were carried out to study the fatigue performance of the butt joints treated by ultrasonic peening, aiming at the improvement of ultrasonic peening treatment(UPT) on welded joints of a new material.The material is a new generation of fine grain and high purity SS400 steel that has the same ingredients as the traditional low carbon steel. The specimens are in two different states:welded and ultrasonic peening conditions.The corresponding fatigue testing data were analyzed according to the regulation of the statistical method for fatigue life of the welded joints established by International Institute of Welding(IIW). Welding residual stress was considered in two different ways: the constant stress ratio R = 0. 5 and the Ohta method. The nominal stress-number (σ-N)curves were corrected because of the different plate thickness compared to the standard and because there was no mismatch or angular deformation. The results indicated that: 1 ) Compared with the welded specimens, when the stress range was 200 MPa, the fatigue life of the SS400 steel specimens treated by ultrasonic peening is prolonged by over 58 times, and the fatigue strength FAT corresponding to 106 cycles is increased by about 66%; 2) As for the SS400 butt joint ( single side welding double sides molding), after being treated by UPT, the nominal S-N curve (m = 10) of FAT 100 MPa(R =0.5) should be used for fatigue design. The standard S-N curves of FAT 100 MPa ( R = 0. 5, m = 10) could be used for fatigue design of the SS400 steel butt joints treated by ultrasonic peening.

  14. A Comparison of Residual Stress Development in Inertia Friction Welded Fine Grain and Coarse Grain Nickel-Base Superalloy

    Science.gov (United States)

    Iqbal, N.; Rolph, J.; Moat, R.; Hughes, D.; Hofmann, M.; Kelleher, J.; Baxter, G.; Withers, P. J.; Preuss, M.

    2011-12-01

    The effect of the base material microstructure on the development of residual stresses across the weld line in inertia friction welds (IFWs) of high-strength nickel-base superalloy RR1000 was studied using neutron diffraction. A comparison was carried out between tubular IFW specimens generated from RR1000 heat treated below (fine grain (FG) structure) and above (coarse grain (CG) structure) the γ'-solvus. Residual stresses were mapped in the as-welded (AW) condition and, after a postweld heat treatment (PWHT), optimized for maximum alloy strength. The highest tensile stresses were generally found in the hoop direction at the weld line near the inner diameter of the tubular-shaped specimens. A comparison between the residual stresses generated in FG and CG RR1000 suggests that the starting microstructure has little influence on the maximum residual stresses generated in the weld even though different levels of energy must be input to achieve a successful weld in each case. The residual stresses in the postweld heat treated samples were about 35 pct less than for the AW condition. Despite the fact that the high-temperature properties of the two parent microstructures are different, no significant differences in terms of stress relief were found between the FG and CG RR1000 IFWs. Since the actual weld microstructures of FG and CG RR1000 inertia welds are very similar, the results suggest that it is the weld microstructure and its associated high-temperature properties rather than the parent material that affects the overall weld stress distribution and its subsequent stress relief.

  15. Numerical simulation of a fine-grained denitrification layer for removing septic system nitrate from shallow groundwater

    Science.gov (United States)

    MacQuarrie, Kerry T. B.; Sudicky, Edward A.; Robertson, William D.

    2001-11-01

    One of the most common methods to dispose of domestic wastewater involves the release of septic effluent from drains located in the unsaturated zone. Nitrogen from such systems is currently of concern because of nitrate contamination of drinking water supplies and eutrophication of coastal waters. It has been proposed that adding labile carbon sources to septic distribution fields could enhance heterotrophic denitrification and thus reduce nitrate concentrations in shallow groundwater. In this study, a numerical model which solves for variably saturated flow and reactive transport of multiple species is employed to investigate the performance of a drain field design that incorporates a fine-grained denitrification layer. The hydrogeological scenario simulated is an unconfined sand aquifer. The model results suggest that the denitrification layer, supplemented with labile organic carbon, may be an effective means to eliminate nitrogen loading to shallow groundwater. It is also shown that in noncalcareous aquifers, the denitrification reaction may provide sufficient buffering capacity to maintain near neutral pH conditions beneath and down gradient of the drain field. Leaching of excess dissolved organic carbon (DOC) from the denitrification layer is problematic, and causes an anaerobic plume to develop in simulations where the water table is less than 5-6 m below ground surface; this anaerobic plume may lead to other down gradient changes in groundwater quality. A drain field and denitrification layer of smaller dimensions is shown to be just as effective for reducing nitrate, but has the benefit of reducing the excess DOC leached from the layer. This configuration will minimize the impact of wastewater disposal in areas where the water table is as shallow as 3.5 m.

  16. A multi-disciplinary study of deformation of the basaltic cover over fine-grained valley fills: a case study from Eastern Sardinia, Italy

    Science.gov (United States)

    Deiana, Rita; Dieni, Iginio; Massari, Francesco; Perri, Maria Teresa; Rossi, Matteo; Brovelli, Alessandro

    2016-06-01

    The Pliocene to Early Pleistocene volcanic activity which generated the basaltic plateau of the Orosei-Dorgali area in Eastern Sardinia led to the disruption of the local hydrographic network by damming some tracts of the fluvial valleys incised in the granite basement. This resulted in the formation of lacustrine basins, whose fine-grained fills were partly interfingered and eventually covered by younger lava flows. In the SW part of the plateau, close to the Galtellì village, a number of unknown depressions, locally named "Paules," were formed. In order to reconstruct their subsurface structure, two electrical resistivity tomography surveys were carried out across these depressions. The geophysical results, which demonstrate the existence of a disrupted layered system, were used to build a numerical geomechanical model that suggest the depressions originated by local collapses of the basaltic cover due to the compaction of the underlying fine-grained valley fills.

  17. Effect of the Fine-Grained Structure on the Fatigue Properties of the Heat-Resistant Nickel-Iron Alloy Inconel 718

    Science.gov (United States)

    Mukhtarov, Sh. Kh.; Shakhov, R. V.

    2015-10-01

    It is well known that ultrafine-grained nickel alloys with average grain sizes d = 0.1-1 μm possess improved hot workability and can be used for superplastic forming or rolling. However, microstructure refinement can worsen some performance characteristics of the alloy, for example, heat-resistant or fatigue properties. In the present work, fatigue characteristics of the fine-grained alloy Inconel 718 are investigated. Ultrafine-grained alloys with average grain sizes d = 0.1-1 μm were manufactured by multiple forging with stage-by-stage deformation temperature decrease. During standard heat treatment of the alloy performed to obtain the desired properties, the γ-grain size was controlled by precipitations of δ-phase particles along the boundaries. Results of low-cycle fatigue tests of the fine-grained alloy at room and elevated temperatures are compared with the properties of the coarse-grained alloy.

  18. Historical developments in marine geology and some aspects of fine-grained sediments along the continental margins of India and Bengal fan

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.

    Content-Type text/plain; charset=UTF-8 29 Historical developments in Marine Geology and some aspects of fine- grained sediments along the continental margins of India and Bengal Fan V. Purnachandra Rao National Institute of Oceanography.... The Andhra University, Waltair made pioneering investigations on the eastern continental margin of India in the early 1950s. However, the International Indian Ocean Expedition (IIOE: 1961-1965) is an important landmark in the history of development...

  19. Phase stability and grain growth in an Ag/Bi-2223 composite conductor prepared using fine-grained Bi-2223 as a precursor.

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, N. N.

    1998-09-17

    We have investigated the stability and microstructural transformability of the Bi-2223 phase in a silver-sheathed monofilament composite tape fabricated using fine-grained Bi{sub 1.7}Pb{sub 0.3}Sr{sub 1.9}Ca{sub 2.0}-Cu{sub 3.0}O{sub y} (Bi-2223) as the precursor powder. The fully formed Bi-2223 precursor was prepared using established procedures. The purpose of this study was to explore the prospects for growing textured, large-grain-size Bi-2223 from the fine-grained precursor by process parameter perturbations. These perturbations included thermal ramp up variations, programmed heat treatment temperature and oxygen pressure fluctuations, and parameter manipulations during cool-down. Our results show that the types of heat treatments used in conventional oxide-powder-in-tube (OPIT) processing do not facilitate Bi-2223 grain growth when the precursor powder is preconcerted Bi-2223. We also observed that the Bi-2223 partially. decomposed during conventional thermal ramp-up in 0.075 atm O{sub 2}, but that this decomposition can be inhibited by ramping up in a reduced oxygen pressure. A pathway was found for back-reacting the fine-grained Bi-2223 (to Bi-2212, Bi-2201 and nonsuperconducting secondary phases), then reforming large-grained Bi-2223 in a colony microstructure having some distinct differences from that produced during conventional OPIT processing.

  20. Vertical migration of fine-grained sediments from interior to surface of seabed driven by seepage flows-`sub-bottom sediment pump action'

    Science.gov (United States)

    Zhang, Shaotong; Jia, Yonggang; Wen, Mingzheng; Wang, Zhenhao; Zhang, Yaqi; Zhu, Chaoqi; Li, Bowen; Liu, Xiaolei

    2017-02-01

    A scientific hypothesis is proposed and preliminarily verified in this paper: under the driving of seepage flows, there might be a vertical migration of fine-grained soil particles from interior to surface of seabed, which is defined as `sub-bottom sediment pump action' in this paper. Field experiments were performed twice on the intertidal flat of the Yellow River delta to study this process via both trapping the pumped materials and recording the pore pressures in the substrate. Experimental results are quite interesting as we did observe yellow slurry which is mainly composed of fine-grained soil particles appearing on the seabed surface; seepage gradients were also detected in the intertidal flat, under the action of tides and small wind waves. Preliminary conclusions are that `sediment pump' occurs when seepage force exceeds a certain threshold: firstly, it is big enough to disconnect the soil particles from the soil skeleton; secondly, the degree of seabed fluidization or bioturbation is big enough to provide preferred paths for the detached materials to migrate upwards. Then they would be firstly pumped from interior to the surface of seabed and then easily re-suspended into overlying water column. Influential factors of `sediment pump' are determined as hydrodynamics (wave energy), degree of consolidation, index of bioturbation (permeability) and content of fine-grained materials (sedimentary age). This new perspective of `sediment pump' may provide some implications for the mechanism interpretation of several unclear geological phenomena in the Yellow River delta area.

  1. Characterization Study on Physical Characteristics of Fine-grained Hematite%微细粒赤铁矿絮凝体物理特性表征研究

    Institute of Scientific and Technical Information of China (English)

    牛福生; 李卓林; 张晋霞

    2016-01-01

    在选矿工业中,絮凝已经被广泛地应用于浮选前微细粒矿石的处理.通过絮凝作用形成絮凝体的性质与实际矿石存在较大差异,基于絮凝分形理论以及欧几里得几何理论对微细粒赤铁矿絮凝体粒径分布、沉速、密度、孔隙率、强度以及分形维数等物理特性进行了表征试验研究,为赤铁矿絮凝体的研究提供理论基础.%In mineral processing industry , flocculation has been widely used in processing fine -grained ore before flotation .But there are great differences between the actual ore and the floc which forms through flocculation .In this paper , the characterization of particle size distribution , sedimentation rate , density , strength and fractal dimension of fine -grained hematite floc was in-vestigated on the basis of flocculation fractal theory and Euclidean geometry theory to study the physical characteristics of fine -grained hematite floc .The results could provide a theoretical basis for hematite flocculation .

  2. Flood-related variations in provenance of fine-grained palaeochannel sediments in the Rhine river basin

    Science.gov (United States)

    van der Perk, Marcel; Toonen, Willem H. J.; Ypma, Jochem; Brewer, Paul A.; Prins, Maarten A.; Macklin, Mark G.; Middelkoop, Hans

    2014-05-01

    In this study, we examine flood-related variations in provenance of fine-grained palaeochannel sediments from the Bienener Altrhein (Germany), an abandoned river channel close to the apex of the Rhine river delta. Geochemical and grain size analyses were conducted on channel-fill sediments from multiple core sections, ranging from 1.15 m to 8.48 m depth, which represents pre-industrial sediment deposited from approximately 1550 AD to 1850 AD. In addition, four sediment cores of ~ 1 m length were retrieved from channel-fills or overbank deposits along the Upper Rhine and the three main tributaries of the Rhine in Germany (Neckar River, Main River and Moselle River). Sediment geochemistry was analysed using an Itrax X-Ray Fluorescence (XRF) core scanner. Four elements (Ti, Co, Rb, W) were selected for further analysis based on the following a priori criteria: (1) The elements must be associated with minerals in the fine particle size fractions; 2) they must not be susceptible to precipitation-dissolution reactions during early diagenenis of the sediment; 3) the elements must be detected in the vast majority of the measurements; 4) the difference between the minimum and maximum number of the XRF counts for the upstream cores must be greater than 50% of the average number of counts. The XRF counts for these elements were standardised to z-scores and were subsequently corrected for the variation clay content ( 150 μm), which was primarily deposited during historical flood events. The results show the Mahalanobis distances are larger than 1 for most increments, which indicates that the four sampled upstream sites do not entirely cover all sources of sediment deposited in the Bienener Altrein channel. The logtransformed Mahalonibis distance correlates significantly (α = 0.05) with the >150 μm particle size fraction for the Upper Rhine River (negative) and the Moselle River (positive). This implies that the proportion of fine sediment that originates from the upper

  3. Production of Seamless Superconducting Radio Frequency Cavities from Ultra-fine Grained Niobium, Phase II Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Roy Crooks, Ph.D., P.E.

    2009-10-31

    The positron and electron linacs of the International Linear Collider (ILC) will require over 14,000, nine-cell, one meter length, superconducting radio frequency (SRF) cavities [ILC Reference Design Report, 2007]. Manufacturing on this scale will benefit from more efficient fabrication methods. The current methods of fabricating SRF cavities involve deep drawing of the halves of each of the elliptical cells and joining them by high-vacuum, electron beam welding, with at least 19 circumferential welds per cavity. The welding is costly and has undesirable effects on the cavity surfaces, including grain-scale surface roughening at the weld seams. Hydroforming of seamless tubes avoids welding, but hydroforming of coarse-grained seamless tubes results in strain-induced surface roughening. Surface roughness limits accelerating fields, because asperities prematurely exceed the critical magnetic field and become normal conducting. This project explored the technical and economic feasibility of an improved processing method for seamless tubes for hydroforming. Severe deformation of bulk material was first used to produce a fine structure, followed by extrusion and flow-forming methods of tube making. Extrusion of the randomly oriented, fine-grained bulk material proceeded under largely steady-state conditions, and resulted in a uniform structure, which was found to be finer and more crystallographically random than standard (high purity) RRR niobium sheet metal. A 165 mm diameter billet of RRR grade niobium was processed into five, 150 mm I.D. tubes, each over 1.8 m in length, to meet the dimensions used by the DESY ILC hydroforming machine. Mechanical properties met specifications. Costs of prototype tube production were approximately twice the price of RRR niobium sheet, and are expected to be comparable with economies of scale. Hydroforming and superconducting testing will be pursued in subsequent collaborations with DESY and Fermilab. SRF Cavities are used to construct

  4. A heat treatment procedure to produce fine-grained lamellar microstructures in a P/M titanium aluminide alloy

    Science.gov (United States)

    Au, Peter

    A process for fabricating advanced aerospace titanium aluminide alloys starting from metal powders (the hot isostatically consolidated P/M process) is presented in this thesis. This process does not suffer the difficulties of chemical inhomogeneities and coarse grain structure of castings. In addition heat treatments which take advantage of the refined structure of HIP processed materials are developed to achieve microstructure control and subsequent mechanical property control. It is shown that a better "property balance" is possible after the heat treatment of HIP consolidated materials than it is with alternative processing. It is well understood that the standard microstructures (near-gamma, duplex, nearly lamellar, and fully lamellar) do not have the balanced mechanical properties (tensile, yield, creep and fatigue strength, ductility and fracture toughness) necessary for optimal performance in aero engine and automotive applications. In this work a fine-grained fully lamellar (FGFL) microstructure is developed for property control and in particular for achieving a much improved property balance. A heat treatment procedure for this purpose which consists of cyclic processing in the alpha transus temperature region to achieve an FGFL structure with grain sizes in the range of 50 mum to 150 mum is presented. Compared with conventional duplex structured materials, the minimum creep rate is an order of magnitude lower with only a 10% loss in tensile yield strength. Moreover, a three-fold increase in tensile elongation is possible by converting to an FGFL structure with only a 30% loss in minimum creep rate. These are attractive trade-offs when considering the use of these alloys for aerospace purposes. A thorough literature review of the mechanisms of formation of standard microstructures and their deformation under mechanical loading is contained in the thesis. In addition, conventional techniques to produce FGFL microstructures in wrought and cast materials are

  5. Stability of fine-grained TT-OSL and post-IR IRSL signals from a i>c.> 1 Ma sequence of aeolian and lacustrine deposits from the Nihewan Basin (northern China)

    DEFF Research Database (Denmark)

    Liu, Jinfeng; Murray, Andrew Sean; Buylaert, Jan-Pieter;

    2016-01-01

    We tested the suitability of the fine-grained quartz (4–11 μm) Optical Stimulated Luminescence (OSL) and thermally-transferred OSL (TT-OSL), and the fine-grained polymineral (4–11 μm) post-infrared IRSL (post-IR IRSL or pIRIR) signals for dating samples from aeolian-lacustrine deposits from the X...

  6. Dating loess with high temperature IRSL signals from polymineral fine grains: luminescence characteristics and comparison with conventional techniques

    Science.gov (United States)

    Thiel, C.; Buylaert, J.-P.; Murray, A. S.; Tsukamoto, S.; Jain, M.; Frechen, M.

    2009-04-01

    It is well known that loess deposits contain detailed terrestrial archives of palaeoenvironmental changes. Unfortunately, loess sequences often lack a reliable absolute chronology, and thus these changes are difficult to constrain in time. Luminescence dating is the technique of choice to address this issue. Quartz and feldspar are the most commonly used dosimeters in luminescence dating. The age range of standard quartz OSL is usually limited by the saturation level of ~200 Gy (corresponding to ~50 ka). In contrast, the age range of feldspar IRSL signals - which usually have a more extended growth curve (up to ~2000 Gy) - is hampered by anomalous fading for which a reliable correction is still not available. Recently, Thomsen et al. (2008) identified several laboratory-induced feldspar signals which show less anomalous fading than the standard IRSL signal stimulated at 50°C. Based on this work, Buylaert et al. (accepted) tested a post-IR IR signal, i.e. IR bleach at 50°C and subsequent IRSL measurement at 225°C, and observed significantly lower fading rates in nature for a number of coarse-grained K-feldspar samples. In this study we explore the possibility of using such a post-IR IR signal from polymineral fine grains extracted from loess. Murray et al. (accepted) showed that a more stringent preheat treatment (320°C for 60 s) can be safely used for feldspar; as a result, we have been able to use a post-IR IR measurement temperature of 290°C, higher than that in the study of Buylaert et al. (accepted), with the expectation that this might further reduce the observed fading rate. The results of the elevated temperature IRSL signal fading measurements clearly indicate a significantly lower fading rate (g2days values typically 1-1.5 %/decade) than the standard IRSL measured at 50°C (g2days values typically 3 %/decade). Results of the performance in the SAR protocol (recycling ratios, recuperation and dose recovery) are very encouraging (measured dose within 15

  7. Normal and abnormal grain growth in fine-grained Nd-Fe-B sintered magnets prepared from He jet milled powders

    Science.gov (United States)

    Bittner, F.; Woodcock, T. G.; Schultz, L.; Schwöbel, C.; Gutfleisch, O.; Zickler, G. A.; Fidler, J.; Üstüner, K.; Katter, M.

    2017-03-01

    Fine-grained, heavy rare earth free Nd-Fe-B sintered magnets were prepared from He jet milled powders with an average particle size of 1.5 μm by low temperature sintering at 920 °C or 980 °C. A coercivity of >1600 kA/m was achieved for an average grain size of 1.68 μm. Transmission electron microscopy showed that the distribution and composition of intergranular and grain boundary junction phases was similar to that in conventionally processed magnets. Microstructural analysis on different length scales revealed the occurrence of abnormal grain growth, which is unexpected for sintering temperatures below 1000 °C. A larger area fraction of abnormal grains was observed in the sample sintered at 920 °C compared to that sintered at 980 °C. Microtexture investigation showed a better crystallographic alignment of the abnormal grains compared to the fine-grained matrix, which is explained by a size dependent alignment of the powder particles during magnetic field alignment prior to sintering. Slightly larger particles in the initial powder show a better alignment and will act as nucleation sites for abnormal grain growth. Magneto-optical Kerr investigations confirmed the lower switching field of the abnormal grains compared to the fine-grained matrix. The demagnetisation curve of the sample sintered at 920 °C showed reduced rectangularity and this was attributed to a cooperative effect of the larger fraction of abnormal grains with low switching field and, as a minor effect, a reduced degree of crystallographic texture in this sample compared to the material sintered at 980 °C, which did not show the reduced rectangularity of the demagnetisation curve.

  8. Fine-grained Authorization Delegation Method Based on Quantified-role%基于量化角色的细粒度授权委托方法

    Institute of Scientific and Technical Information of China (English)

    吴春雷

    2012-01-01

    目前基于角色的访问控制模型大多数都不支持细粒度操作.为此,提出一种细粒度的授权委托方法.利用为权限元组分配量值的方法,实现对角色内任意部分权限的表达和控制.引入量化角色,将普通角色与权限量值组合,用于描述不同的权限范围.在胜利油田滨南采油厂物资供应系统中的应用结果表明,该方法能提供更细化的授权和委托粒度,减少过多临时角色的创建,降低系统的管理和维护代价.%The current role-based access control models often have deficiencies in the fine-grained authorization and delegation, so a fine-grained method for authorization and delegation is presented. With qualified value allocated for permission tuples, any part permission of a role can be accurately expressed and controlled. By introduction of the quantified-rote, a common role can be described different privileges with different permission values. Application results in the materials supply system of binnan oil production plant of Shengli oilfield show that the method can provide more fine-grained authorization and delegation, reduce generation of excessive temporary roles, and lower costs of system management and maintenance.

  9. Laves-phase evolution during aging in fine grained heat-affected zone of a tungsten-strengthened 9% Cr steel weldment

    OpenAIRE

    Wang, Xue; XU, Qiang; Yu, Shu-min; Liu, Hong; Hu, Lei; Ren, Yao-yao

    2015-01-01

    The precipitation and coarsening of Laves-phase in the fine grained heat-affected zone (FGHAZ) of a 9% Cr steel P92 welded joint during thermal aging at 923 K were investigated and compared to the base metal (BM), in order to clarify their effects on the Type IV fracture. Laves-phase precipitated mostly on the prior austenite grain boundaries of the FGHAZ. In comparison with BM, FGHAZ contained more grain boundary areas and can provide more nucleation sites for Laves-phase, resulting in an ac...

  10. On the microstructural and magnetic properties of fine-grained CoFe2O4 ceramics produced by combining polyol process and spark plasma sintering

    Science.gov (United States)

    Gaudisson, T.; Artus, M.; Acevedo, U.; Herbst, F.; Nowak, S.; Valenzuela, R.; Ammar, S.

    2014-12-01

    Starting from polyol-made CoFe2O4 ferrite nanoparticles of different aggregation states, high-density fine-grained ceramics were produced using Spark Plasma Sintering technique at 600 and 500 °C, under vacuum and applying a uniaxial pressure of more than 80 MPa. The grain growth of thus produced ceramics appears to be proportional to the temperature plateau and inversely proportional to the aggregation state of the initial powders. Average grain sizes ranging between about 50 and 350 nm were obtained. In all the cases, magnetic measurements evidenced a ferrimagnetic behavior at room temperature with non-zero coercivity, while their starting powders exhibited superparamagnetic features.

  11. The influence of grain size, grain color, and suspended-sediment concentration on light attenuation: why fine-grained terrestrial sediment is bad for coral reef ecosystems

    Science.gov (United States)

    Storlazzi, Curt; Norris, Benjamin; Rosenberger, Kurt

    2015-01-01

    Sediment has been shown to be a major stressor to coral reefs globally. Although many researchers have tested the impact of sedimentation on coral reef ecosystems in both the laboratory and the field and some have measured the impact of suspended sediment on the photosynthetic response of corals, there has yet to be a detailed investigation on how properties of the sediment itself can affect light availability for photosynthesis. We show that finer-grained and darker-colored sediment at higher suspended-sediment concentrations attenuates photosynthetically active radiation (PAR) significantly more than coarser, lighter-colored sediment at lower concentrations and provide PAR attenuation coefficients for various grain sizes, colors, and suspended-sediment concentrations that are needed for biophysical modeling. Because finer-grained sediment particles settle more slowly and are more susceptible to resuspension, they remain in the water column longer, thus causing greater net impact by reducing light essential for photosynthesis over a greater duration. This indicates that coral reef monitoring studies investigating sediment impacts should concentrate on measuring fine-grained lateritic and volcanic soils, as opposed to coarser-grained siliceous and carbonate sediment. Similarly, coastal restoration efforts and engineering solutions addressing long-term coral reef ecosystem health should focus on preferentially retaining those fine-grained soils rather than coarse silt and sand particles.

  12. 某细粒浸染铜锌矿选矿工艺研究%The Mineral Processing Technology forone Fine-grained Disseminated Copper-zinc Ore

    Institute of Scientific and Technical Information of China (English)

    何晋勇; 陆长龙; 肖骏

    2016-01-01

    The mineral processing technology investigation is conducted on one fine-grained disseminated copper-zinc ore in Yunnan. The sulphide minerals have a complex metasomatic embedded relationship in this copper-zinc ore. The mineral processing flow that copper differential flotation, regrinding of copper rough concentrate, activation flotation of zinc from copper tailings is adopted, which improved the single separation degree of fine-grained disseminated and embedded copper pyrites and sphalerite. Meanwhile, by using BP+ ethyl xanthogenate as the collecting agent of copper ore, Na2S+Na2SO3+ZnSO4 as the combined depressants of zinc ore, therefore the effective separation between fine-grained disseminated copper-zinc ore was achieved. Under the conditions that in the raw ore, copper content is 0.82%, zinc content is 2.21%, we can get the indexes that copper concentrate with Cu 20.92%, Zn 2.89%, the recovery rate of Cu is 87.41% in the copper concentrate, the Cu content is 1.24% in zinc concentrate, The Zn recovery rate is 89.15% in the zinc concentrate.%针对云南某细粒浸染铜锌矿开展了选矿工艺研究.该铜锌矿中的硫化矿物具有复杂的交代嵌生关系,本研究采用优先浮铜-铜粗精矿再磨-铜尾矿活化浮选锌的工艺流程,提高了细粒浸染交代嵌生的黄铜矿、闪锌矿的单体解离度.同时,使用BP+乙黄药做铜矿物的组合捕收剂, Na2S+Na2SO3+ZnSO4做锌矿物组合抑制剂,实现了细粒浸染铜锌矿的有效分离.在原矿含铜0.82%、锌2.21%的情况下,获得了铜精矿含Cu 20.92%、Zn 2.89%,铜精矿中Cu回收率87.41%,锌精矿含Cu 1.24%、Zn 43.34%,锌精矿中Zn回收率89.15%的指标.

  13. Influence of Al sub 2 O sub 3 nanoparticles on the thermal stability of ultra-fine grained copper prepared by high pressure torsion

    CERN Document Server

    Cizek, J; Kuzel, R; Islamgaliev, R K

    2002-01-01

    Ultra-fine grained (UFG) Cu (grain size 80 nm) containing 0.5 wt.% Al sub 2 O sub 3 nanoparticles (size 20 nm) was prepared by high pressure torsion (HPT). Positron lifetime spectroscopy was employed to characterize the microstructure of this material, especially with respect to types and concentration of lattice defects. The evolution of microstructure with increasing temperature was studied by positron lifetime spectroscopy and x-ray diffraction measurements. The thermal stability of the Cu + 0.5 wt.% Al sub 2 O sub 3 nanocomposite was compared with that of pure UFG Cu prepared by the same technique. The processes taking place during thermal recovery of the initial nanoscale structure in both studied materials are described. (author)

  14. Upwelling-driven reworking of a MTD's fine-grained plume: an example at the Cariaco Basin/Cariaco Gulf connection.

    Science.gov (United States)

    Aguilar, Iliana; Beck, Christian; Audemard, Franck; Crouzet, Christian; Sabatier, Pierre; Develle, Anne-Lise; Boussafir, Mohammed; Campos, Corina

    2016-04-01

    The Cariaco Basin is a 1400 m-deep and 90 km-wide pull-apart basin, in the south-eastern corner of the Caribbean Sea. To the East, it is connected to the Cariaco Gulf, a 60 km-long, 15 km-wide, and 90 m-deep appendix. Both are E-W elongated and developed upon the south-eastern transform boundary of the Caribbean Plate, an active limit here mainly represented by the El Pilar Fault. The Gulf of Cariaco entrance is a 55 m-deep, and 5 km-wide sill mainly controlled by the large Manzanares River delta, which western foreset slope is facing the Basin's eastern edge. Within this connection area, two particular sedimentary processes have been previously documented: 1) strong seasonal upwelling responsible for the transfer of deep particulate organic matter from the Basin into the Gulf; 2) the recent occurrence, in the Basin, of a fine-grained suspension related to a submarine landslide; this event was detected after the 1997 Cariaco earthquake (Thunell et al., 1999; Lorenzoni et al., 2012) and was related to a slope failure of the Manzanares delta western foreset. From short gravity cores retrieved in the Gulf, we analysed the last millennium of sedimentation (components, transport and settling processes) using classical proxies and physical properties. All parameters led to underline: - a permanent mixed provenance of particulate Organic Matter in the main part of the Gulf: i) in situ and ii) allochtonous; - the occurrence of coarse siliciclastic layers related to flooding from the southern edge of the Gulf; - the occurrence of one peculiar fine-grained siliciclastic layer with a widespread distribution, dated around 1850 AD; - an abrupt increase of open marine influence just after the above-mentioned layer. Concerning the "background" permanent sedimentation, these results confirm the importance of upwelling through the connection between the Gulf and the Basin (transfer of the "allochtonous" O.M.). For the fine-grained silicilastic "event", we could discard a

  15. The impact of disposal of fine-grained sediments from maintenance dredging works on SPM concentration and fluid mud in and outside the harbor of Zeebrugge

    Science.gov (United States)

    Fettweis, Michael; Baeye, Matthias; Cardoso, Claudio; Dujardin, Arvid; Lauwaert, Brigitte; Van den Eynde, Dries; Van Hoestenberghe, Thomas; Vanlede, Joris; Van Poucke, Luc; Velez, Carlos; Martens, Chantal

    2016-11-01

    The amount of sediments to be dredged and disposed depends to a large part on the suspended particulate matter (SPM) concentration. Tidal, meteorological, climatological, and seasonal forcings have an influence on the horizontal and vertical distribution of the SPM in the water column and on the bed and control the inflow of fine-grained sediments towards harbors and navigation channels. About 3 million tons (dry matter) per year of mainly fine-grained sediments is dredged in the port of Zeebrugge and is disposed on a nearby disposal site. The disposed sediments are quickly resuspended and transported away from the site. The hypothesis is that a significant part of the disposed sediments recirculates back to the dredging places and that a relocation of the disposal site to another location at equal distance to the dredging area would reduce this recirculation. In order to validate the hypothesis, a 1-year field study was set up in 2013-2014. During 1 month, the dredged material was disposed at a new site. Variations in SPM concentration were related to tides, storms, seasonal changes, and human impacts. In the high-turbidity Belgian near-shore area, the natural forcings are responsible for the major variability in the SPM concentration signal, while disposal has only a smaller influence. The conclusion from the measurements is that the SPM concentration decreases after relocation of the disposal site but indicate stronger (first half of field experiment) or weaker (second half of field experiment) effects that are, however, supported by the environmental conditions. The results of the field study may have consequences on the management of disposal operations as the effectiveness of the disposal site depends on environmental conditions, which are inherently associated with chaotic behavior.

  16. Preparation of fine-grained tungsten heavy alloys by spark plasma sintered W–7Ni–3Fe composite powders with different ball milling time

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, D.P., E-mail: dpxiang@hainu.edu.cn [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China); School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Ding, L. [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China); Li, Y.Y.; Chen, G.B. [School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Zhao, Y.W. [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China)

    2013-06-15

    Highlights: ► We fabricate fine-grained W–7Ni–3Fe alloys using HEBM assisted SPS method. ► The γ-(Ni, Fe, W) phase is not observed in HEBM raw powders. ► The density of the WHAs gradually decreased with increasing HEBM time. ► The hardness and bending strength of the WHAs show different trends of variation. ► The intergranular fracture was the main bending fracture mode of the WHAs. -- Abstract: The fine-grained tungsten heavy alloys (WHAs) with grain size of about 1–3 μm were successfully prepared by spark plasma sintered W–7Ni–3Fe composite powders with different high-energy ball milling (HEBM) time. This study analyzes the effects of HEBM time not only on the composite powders but on the microstructure and mechanical properties of WHAs. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to investigate the microstructure and phase evolution rules of powders and alloys, respectively. The γ-(Ni, Fe, W) is not observed in XRD patterns of the ball milled powders. With prolonging HEBM time, the W phase diffraction peak becomes increasingly wider, and its intensity continues to decline. However, the completely amorphous structures are not formed even after HEBM 40 h. The relative density of the WHAs prepared by HEBM assisted SPS technique decreases gradually with increasing the ball milling time. For the WHAs sintered in 1150 °C for 8 min, the W grains grow finer and the content of the γ-(Ni, Fe, W) binding phase greatly increases with prolonging the HEBM time. Meanwhile, over 5 h of HEBM time, the bending strength continuously decreases and the hardness slightly increases. The intergranular fracture of the W grains is the main bending fracture mode in all the WHAs. The microporous of different sizes are distributed on the bending fracture and progressively increased with prolonging the ball milling time.

  17. Comparative analysis of dose rates in bricks determined by neutron activation analysis, alpha counting and X-ray fluorescence analysis for the thermoluminescence fine grain dating method

    Science.gov (United States)

    Bártová, H.; Kučera, J.; Musílek, L.; Trojek, T.

    2014-11-01

    In order to evaluate the age from the equivalent dose and to obtain an optimized and efficient procedure for thermoluminescence (TL) dating, it is necessary to obtain the values of both the internal and the external dose rates from dated samples and from their environment. The measurements described and compared in this paper refer to bricks from historic buildings and a fine-grain dating method. The external doses are therefore negligible, if the samples are taken from a sufficient depth in the wall. However, both the alpha dose rate and the beta and gamma dose rates must be taken into account in the internal dose. The internal dose rate to fine-grain samples is caused by the concentrations of natural radionuclides 238U, 235U, 232Th and members of their decay chains, and by 40K concentrations. Various methods can be used for determining trace concentrations of these natural radionuclides and their contributions to the dose rate. The dose rate fraction from 238U and 232Th can be calculated, e.g., from the alpha count rate, or from the concentrations of 238U and 232Th, measured by neutron activation analysis (NAA). The dose rate fraction from 40K can be calculated from the concentration of potassium measured, e.g., by X-ray fluorescence analysis (XRF) or by NAA. Alpha counting and XRF are relatively simple and are accessible for an ordinary laboratory. NAA can be considered as a more accurate method, but it is more demanding regarding time and costs, since it needs a nuclear reactor as a neutron source. A comparison of these methods allows us to decide whether the time- and cost-saving simpler techniques introduce uncertainty that is still acceptable.

  18. Towards 3D Face Recognition in the Real: A Registration-Free Approach Using Fine-Grained Matching of 3D Keypoint Descriptors

    KAUST Repository

    Li, Huibin

    2014-11-12

    Registration algorithms performed on point clouds or range images of face scans have been successfully used for automatic 3D face recognition under expression variations, but have rarely been investigated to solve pose changes and occlusions mainly since that the basic landmarks to initialize coarse alignment are not always available. Recently, local feature-based SIFT-like matching proves competent to handle all such variations without registration. In this paper, towards 3D face recognition for real-life biometric applications, we significantly extend the SIFT-like matching framework to mesh data and propose a novel approach using fine-grained matching of 3D keypoint descriptors. First, two principal curvature-based 3D keypoint detectors are provided, which can repeatedly identify complementary locations on a face scan where local curvatures are high. Then, a robust 3D local coordinate system is built at each keypoint, which allows extraction of pose-invariant features. Three keypoint descriptors, corresponding to three surface differential quantities, are designed, and their feature-level fusion is employed to comprehensively describe local shapes of detected keypoints. Finally, we propose a multi-task sparse representation based fine-grained matching algorithm, which accounts for the average reconstruction error of probe face descriptors sparsely represented by a large dictionary of gallery descriptors in identification. Our approach is evaluated on the Bosphorus database and achieves rank-one recognition rates of 96.56, 98.82, 91.14, and 99.21 % on the entire database, and the expression, pose, and occlusion subsets, respectively. To the best of our knowledge, these are the best results reported so far on this database. Additionally, good generalization ability is also exhibited by the experiments on the FRGC v2.0 database.

  19. Theory of compact nonporous windscreens for infrasonic measurements.

    Science.gov (United States)

    Zuckerwar, Allan J

    2010-06-01

    The principle of the compact nonporous windscreen is based on the great penetrability of infrasound through matter. The windscreen performance is characterized by the ratio of the sound pressure at an interior microphone, located in the center of a windscreen, to the incident sound pressure in the free field. The frequency dependence of this pressure ratio is derived as a function of the windscreen material and geometric properties. Four different windscreen geometries are considered: a subsurface, box-shaped windscreen, a cylindrical windscreen of infinite length, a cylindrical windscreen of finite length, and a spherical windscreen. Results are presented for windscreens made of closed-cell polyurethane foam and for typical dimensions of each of the above geometries. The cylindrical windscreen of finite length, featuring evanescent radial modes, behaves as a unity-gain, low-pass filter, cutting off sharply at the end of the infrasonic range. The remaining geometries reveal a pass band that extends well into the audio range, terminated by a pronounced peak beyond which the response plummets rapidly.

  20. Sticking of molecules on non-porous amorphous water ice

    CERN Document Server

    He, Jiao; Vidali, Gianfranco

    2016-01-01

    Accurate modeling of physical and chemical processes in the interstellar medium requires detailed knowledge of how atoms and molecule adsorb on dust grains. However, the sticking coefficient, a number between 0 and 1 that measures the first step in the interaction of a particle with a surface, is usually assumed in simulations of ISM environments to be either 0.5 or 1. Here we report on the determination of the sticking coefficient of H$_2$, D$_2$, N$_2$, O$_2$, CO, CH$_4$, and CO$_2$ on non-porous amorphous solid water (np-ASW). The sticking coefficient was measured over a wide range of surface temperatures using a highly collimated molecular beam. We showed that the standard way of measuring the sticking coefficient --- the King-Wells method --- leads to the underestimation of trapping events in which there is incomplete energy accommodation of the molecule on the surface. Surface scattering experiments with the use of a pulsed molecular beam are used instead to measure the sticking coefficient. Based on th...

  1. Fine-grained sediment gravity flow deposits induced by flood and lake slope failure events: examples of lacustrine varved sediments in Japan

    Science.gov (United States)

    Ishihara, Yoshiro; Sasaki, Yasunori; Sasaki, Hana; Onishi, Yuri

    2016-04-01

    Fine-grained sediment gravity flow deposits induced by flood and lake slope failure events are frequently intercalated in lacustrine successions. When sediment gravity flow deposits are present in varved sediments, it is suggested that they provide valuable information about sediment gravity flows, because they can easily trace laterally and can give the magnitude of erosion and recurrence interval of events. In addition, because large sedimentary bodies of stacked sediment gravity flow deposits in varved sediments of a calm lake are not suggested, a relatively simple depositional environment is expected. In the present study, we analysed sedimentary facies of sediment gravity flow deposits in varved lacustrine diatomites in the Middle Pleistocene Hiruzenbara and Miyajima formations in Japan, and concluded a depositional model of the lacustrine sediment gravity flow deposits. Varved diatomites: The Hiruzenbara Fm., a dammed lake fill as foots of Hiruzen Volcanos, is deposited during an interglacial period during MIS12 to 15. Varves of ca. 8000 yr were measured in a 20 m intercalating flood and lake slope failure-induced sediment gravity flow deposits. The Miyajima Fm., distributed in a paleo-caldera lake in NE Japan, includes many sediment gravity flow deposits possibly originated from fandeltas around the lake. These formations have differences in their depositional setting; the Hiruzebara Fm. was deposited in a large lake basin, whereas the Miyajima Fm. was deposited in a relatively small basin. Because of the depositional setting, intercalation of volcaniclastics is dominant in the Miyajima Fm. Lacustrine sediment gravity flow deposits: Sediment gravity flow deposits in both formations can be classified into flood- and lake slope failure-induced types based on the sedimentary facies. Composites of the both types are also found. Flood-induced types comprise fine-grained silts dominated by carbonaceous fragments, whereas lake slope failure-induced types are

  2. Geochemistry of fine-grained sediments of the upper Cretaceous to Paleogene Gosau Group (Austria, Slovakia: Implications for paleoenvironmental and provenance studies

    Directory of Open Access Journals (Sweden)

    Gerald Hofer

    2013-07-01

    Full Text Available Bulk rock geochemistry of 169 fine-grained sediment samples of the upper Cretaceous to Paleogene Gosau Group (Northern Calcareous Alps, Austria and Slovakia from borehole and outcrop localities was performed to separate non-marine and marine deposits. Geochemical characteristics of different Gosau depositional systems, basins and sediment provenance using major-, trace-, and rare earth elements were also investigated. Geochemical proxies such as boron concentrations were tested for seeking the possibilities of paleosalinity indicators. Due to the fact that several pelagic sections are represented by extremely low boron contents, B/Al* ratios are recognized as more robust and differentiate reliably between marine (mean: 160 ± 34 and non-marine (mean: 133 ± 33 samples. Using statistical factor analysis, hemipelagic to pelagic samples from the Gießhübl Syncline and Slovakian equivalents can be differentiated from marginal-marine to non-marine samples from the Grünbach and Glinzendorf Syncline related to terrigenous (SiO2, Al2O3, K2O, Th, Rb, Zr and others and pelagic indicative elements (CaO, Sr, TOT/C and B/Al*. A clear indication for ophiolitic provenance is traced by high amounts of chromium and nickel. Only non-marine successions of the Glinzendorf Syncline show higher Cr and Ni concentrations (up to 250 and 400 ppm, respectively and enriched Cr/V and Y/Ni ratios trending to an ultramafic source.

  3. Fabricating fine-grained tungsten heavy alloy by spark plasma sintering of low-energy ball-milled W–2Mo–7Ni–3Fe powders

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, D.P., E-mail: dpxiang@hainu.edu.cn [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China); School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Ding, L. [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China); Li, Y.Y. [School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Chen, X.Y.; Zhang, T.M. [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China)

    2013-08-20

    Fine-grained W–2Mo–7Ni–3Fe heavy alloys were fabricated by low-energy ball milling (LEBM)-assisted spark plasma sintering at a temperature range of 1000–1250 °C. The effects of sintering temperature on the phase evolution, microstructural characteristics, and mechanical properties of the alloys were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), hardness testing, and universal testing. The XRD results show that small intermetallic compounds, such as NiW and Ni{sub 2}W{sub 4}C, form in the alloys. The W–2Mo–7Ni–3Fe alloys are characterized by white W grains, a gray W-rich microstructure that contains Mo, and a black γ–(Ni, Fe, W, Mo) binding phase. The X-ray energy dispersive analysis (EDS) shows that the Mo, Ni, and Fe that form a solid solution with W in the gray structure gradually decrease with increasing temperature. The hardness and bending strength of the alloys initially increase and then decrease with rising sintering temperature. Moreover, the alloys sintered at different temperatures exhibit dissimilar bending fracture modes.

  4. Superplasticity of a fine-grained Mg–9Gd–4Y–0.4Zr alloy evaluated using shear punch testing

    Directory of Open Access Journals (Sweden)

    Reza Alizadeh

    2014-07-01

    Full Text Available The superplasticity of an extruded fine-grained Mg–9Gd–4Y–0.4Zr alloy was investigated by measuring the strain rate sensitivity using shear punch testing (SPT. Shear punch tests were conducted at shear strain rates in the range of 3 × 10−3–2 × 10−1 s−1 and at temperatures in the range of 573–773 K. The results indicate the strain rate sensitivity, m, increases from about 0.11 at 573 K to about 0.40 at 723 K and then decreases to 0.32 with a further increase in test temperature. A strain rate sensitivity of 0.40 and an activation energy of 140 kJ/mol are indicative of a superplastic deformation behavior dominated by grain boundary sliding accommodated by lattice diffusion at temperatures above 673 K.

  5. A Bi-Modal Distribution of ALHA77307 Matrix Olivine: Evidence for Fine-Grained Mixing from Multiple Reservoirs in the CO Formation Zone

    Science.gov (United States)

    Frank, D.; Zolensky, Michael E.; Brearley, A.; Le, L.

    2011-01-01

    The CO 3.0 chondrite ALHA77307 is thought to be the least metamorphosed of all the CO chondrites [1]. As such, the fine-grained (olivine found in its matrix is a valuable resource for investigating the CO formation environment since its compositions should be primary. In the CO matrix, we indeed find a wide range of major element compositions (Fa(0.5-71)). However, more importantly, we find that the olivines make up two compositionally distinct populations (Fa(0.5-5) and Fa(21-71)). Grains from both populations are found within an extremely close proximity and we see no obvious evidence of two distinct lithologies within our samples. Therefore, we conclude that the olivine grains found in the ALHA77307 matrix must have crystallized within two unique formation conditions and were later mixed at a very fine scale during the accretion epoch. Here, we propose a possible explanation based on Cr and Mn concentrations in the olivine.

  6. Sorption of Fe (Hydr)Oxides to the Surface of Shewanella putrefaciens: Cell-Bound Fine-Grained Minerals Are Not Always Formed De Novo

    Science.gov (United States)

    Glasauer, S.; Langley, S.; Beveridge, T. J.

    2001-01-01

    Shewanella putrefaciens, a gram-negative, facultative anaerobe, is active in the cycling of iron through its interaction with Fe (hydr)oxides in natural environments. Fine-grained Fe precipitates that are attached to the outer membranes of many gram-negative bacteria have most often been attributed to precipitation and growth of the mineral at the cell surface. Our study of the sorption of nonbiogenic Fe (hydr)oxides revealed, however, that large quantities of nanometer-scale ferrihydrite (hydrous ferric oxide), goethite (α-FeOOH), and hematite (α-Fe2O3) adhered to the cell surface. Attempts to separate suspensions of cells and minerals with an 80% glycerin cushion proved that the sorbed minerals were tightly attached to the bacteria. The interaction between minerals and cells resulted in the formation of mineral-cell aggregates, which increased biomass density and provided better sedimentation of mineral Fe compared to suspensions of minerals alone. Transmission electron microscopy observations of cells prepared by whole-mount, conventional embedding, and freeze-substitution methods confirmed the close association between cells and minerals and suggested that in some instances, the mineral crystals had even penetrated the outer membrane and peptidoglycan layers. Given the abundance of these mineral types in natural environments, the data suggest that not all naturally occurring cell surface-associated minerals are necessarily formed de novo on the cell wall. PMID:11722905

  7. Fine-grained parallelization of the Car-Parrinello ab initio molecular dynamics method on the IBM Blue Gene/L supercomputer

    Energy Technology Data Exchange (ETDEWEB)

    E. Bohm A. Bhatele L. V. Kale M. E. Tuckerman S. Kumar J. A. Gunnels G. J. Martyna; Bohm, E. [Thomas M. Siebel Center, Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States). Dept of Computer Science; Bhatele, A. [Thomas M. Siebel Center, Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States). Dept of Computer Science; Kale, L. V. [Thomas M. Siebel Center, Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States). Dept of Computer Science; Tuckerman, M. E. [New York Univ., NY (United States). Dept. of Chemistry and Courant Institute of Mathematical Sciences; Kumar, S. [IBM T. J. Watson Research Center, Yorktown Heights, NY (United States). IBM Research Division; Gunnels, J. A. [IBM T. J. Watson Research Center, Yorktown Heights, NY (United States). IBM Research Division; Martyna, G. J. [IBM T. J. Watson Research Center, Yorktown Heights, NY (United States). IBM Research Division

    2008-01-01

    Important scientific problems can be treated via ab initio-based molecular modeling approaches, wherein atomic forces are derived from an energy Junction that explicitly considers the electrons. The Car-Parrinello ab initio molecular dynamics (CPAIMD) method is widely used to study small systems containing on the order of 10 to 103 atoms. However, the impact of CPAIMD has been limited until recently because of difficulties inherent to scaling the technique beyond processor numbers about equal to the number of electronic states. CPAIMD computations involve a large number of interdependent phases with high interprocessor communication overhead. These phases require the evaluation of various transforms and non-square matrix multiplications that require large interprocessor data movement when efficiently parallelized. Using the Charm++ parallel programming language and runtime system, the phases are discretized into a large number of virtual processors, which are, in turn, mapped flexibly onto physical processors, thereby allowing interleaving of work. Algorithmic and IBM Blue Gene/L(tm) system-specific optimizations are employed to scale the CPAIMD method to at least 30 times the number of electronic states in small systems consisting of 24 to 768 atoms (32 to 1,024 electronic states) in order to demonstrate fine-grained parallelism. The largest systems studied scaled well across the entire machine (20,480 nodes).

  8. Effective strategy for pyramiding three bacterial blight resistance genes into fine grain rice cultivar, Samba Mahsuri, using sequence tagged site markers.

    Science.gov (United States)

    Kottapalli, Kameswara Rao; Lakshmi Narasu, M; Jena, Kshirod K

    2010-07-01

    Bacterial leaf blight (BB) of rice is a major disease limiting rice production in several rice growing regions of the world. The pathogen, Xanthomonas oryzae pv oryzae, causing the disease is highly virulent to rice crops and is capable of evolving new races. Breeding efforts to incorporate single BB resistant gene often leads to resistance breakdown within a short period. To overcome such breakdown of resistance and develop germplasm with durable disease resistance, we have introgressed three bacterial blight resistance genes, xa5, xa13, and Xa21 into a fine grain rice variety, Samba Mahsuri, using sequence tagged site (STS) markers linked to these genes. Since the efficiency of the STS markers linked to recessive genes to detect homozygotes is less than 100%, we adopted four different pyramiding schemes to minimize loss of recessive resistance genes in advanced backcross generations. Pyramiding scheme A in which a two-gene Samba Mahsuri pyramid line containing Xa21 and xa5 genes was crossed with the Samba Mahsuri line having xa13 gene alone was found to be most effective in preventing the loss of an important recessive gene xa13. We further demonstrated that there was no yield penalty due to pyramiding of multiple genes into the elite indica rice variety.

  9. Effective inhibition of the early copper ion burst release with ultra-fine grained copper and single crystal copper for intrauterine device application.

    Science.gov (United States)

    Xu, X X; Nie, F L; Wang, Y B; Zhang, J X; Zheng, W; Li, L; Zheng, Y F

    2012-02-01

    To solve the main problems of existing coarse grained copper (CG Cu) intrauterine devices (IUD)-namely burst release and a low transfer efficiency of the cupric ions during usage-ultra-fine grained copper (UFG Cu) and single crystal copper (SC Cu) have been investigated as potential substitutes. Their corrosion properties with CG Cu as a control have been studied in simulated uterine fluid (SUF) under different conditions using electrochemical measurement methods. Long-term immersion of UFG Cu, SC Cu and CG Cu samples in SUF at 37 °C have been studied for 300 days. A lower copper ion burst release and a higher efficiency release of cupric ions were observed for UFG Cu and SC Cu compared with CG Cu in the first month of immersion and 2 months later. The respective corrosion mechanisms for UFG Cu, SC Cu and CG Cu in SUF are proposed. In vitro biocompatibility tests show a better cellular response to UFG Cu and SC Cu than CG Cu. In terms of instantaneous corrosion behavior, long-term corrosion performance and in vitro biocompatibility, the three pure copper materials follow the order: UFG Cu>SC Cu>CG Cu, which indicates that UFG Cu could be the most suitable candidate material for intrauterine devices.

  10. Development of Fine-Grained, Low-Carbon Bainitic Steels with High Strength and Toughness Produced Through the Conventional Hot-Rolling and Air-Cooling

    Science.gov (United States)

    Dhua, Sanjay Kumar; Sarkar, Partha Pratim; Saxena, Atul; Jha, Bimal Kumar

    2016-09-01

    Low-carbon bainitic steels have created enormous interest among scientists across the world in the past few decades because of their high strength, toughness, and weldability replacing the conventional quenched and tempered medium-carbon steels. Three experimental steels with varying alloy additions were made in a 100-kg laboratory induction furnace and cast into 100-mm-diameter cylindrical ingots. These ingots were hot-rolled and air-cooled to 6-mm plates in an experimental rolling mill with selected thermomechanical parameters. Steels processed through this process provided an ultrafine low-carbon bainitic microstructure with maximum yield strength (YS) and ultimate tensile strength (UTS) 575 and 705 MPa, respectively. The Charpy impact toughness of the experimental steels was excellent, and at 253 K (-20 °C), it varied from 114 to 170 Joules. Cu-B-added steel was found to give an optimum combination of strength, YS-575 MPa, and toughness, 114 J at 253 K (-20 °C). Thus, fine-grained, low-carbon bainitic steels could be developed with a proper combination of alloying elements and thermomechanical parameters even by air-cooling.

  11. Effects of grain size on high temperature creep of fine grained, solution and dispersion hardened V-1.6Y-8W-0.8TiC

    Energy Technology Data Exchange (ETDEWEB)

    Furuno, T. [Ehime Univerisity, 3 Bunkyo-cho, Matsuyama 790-8577 (Japan); Kurishita, H., E-mail: kurishi@imr.tohoku.ac.jp [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Nagasaka, T.; Nishimura, A.; Muroga, T. [Fusion Engineering Research Center, National Institute for Fusion Science (NIFS), Oroshi-cho 322-6, Tok, Gifu 292 (Japan); Sakamoto, T.; Kobayashi, S.; Nakai, K. [Department of Materials Science and Biotechnology, Ehime Univerisity, 3 Bunkyo-cho, Matsuyama 790-8577 (Japan); Matsuo, S.; Arakawa, H. [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai, Ibaraki 311-1313 (Japan)

    2011-10-01

    Creep resistance is the major concern of vanadium and its alloys for fusion reactor structural applications. In order to elucidate the effects of grain size on the creep behavior of solution and dispersion strengthened vanadium alloys, V-1.6Y-8W-0.8TiC specimens with fine grain sizes from 0.58 to 1.45 {mu}m were prepared by mechanical alloying and HIP without any plastic working and tested at 1073 K and 250 MPa in vacuum. It is shown that the creep resistance of V-1.6Y-8W-0.8TiC depends strongly on grain size and increases with increasing grain size: The creep life for the grain size of 1.45 {mu}m is almost one order longer than that of 0.58 {mu}m, and about two orders longer than that of V-4Cr-4Ti (NIFS-Heat 2) although the grain size of V-4Cr-4Ti is as large as 17.8 {mu}m. The observed creep behavior is discussed in terms of grain size effects on dislocation glide and grain boundary sliding.

  12. Development of Fine-Grained, Low-Carbon Bainitic Steels with High Strength and Toughness Produced Through the Conventional Hot-Rolling and Air-Cooling

    Science.gov (United States)

    Dhua, Sanjay Kumar; Sarkar, Partha Pratim; Saxena, Atul; Jha, Bimal Kumar

    2016-12-01

    Low-carbon bainitic steels have created enormous interest among scientists across the world in the past few decades because of their high strength, toughness, and weldability replacing the conventional quenched and tempered medium-carbon steels. Three experimental steels with varying alloy additions were made in a 100-kg laboratory induction furnace and cast into 100-mm-diameter cylindrical ingots. These ingots were hot-rolled and air-cooled to 6-mm plates in an experimental rolling mill with selected thermomechanical parameters. Steels processed through this process provided an ultrafine low-carbon bainitic microstructure with maximum yield strength (YS) and ultimate tensile strength (UTS) 575 and 705 MPa, respectively. The Charpy impact toughness of the experimental steels was excellent, and at 253 K (-20 °C), it varied from 114 to 170 Joules. Cu-B-added steel was found to give an optimum combination of strength, YS-575 MPa, and toughness, 114 J at 253 K (-20 °C). Thus, fine-grained, low-carbon bainitic steels could be developed with a proper combination of alloying elements and thermomechanical parameters even by air-cooling.

  13. Effect of Magnetostatic Interactions on Twin Boundary Motion in NiMnGa Magnetic Shape Memory Alloy

    DEFF Research Database (Denmark)

    Heczko, Oleg; Vokoun, David; Kopecky, Vit

    2015-01-01

    We investigated the effect of magnetostatic interactions on the field-induced reorientation of martensite variants in Ni50.0Mn27.5Ga22.5. The reorientation, achieved by sweeping a single Type-II twin boundary along the sample, was triggered by a twinning stress of about 0.1 MPa. However, depending...... on the initial position of the twin boundary, the magnetic field providing the critical stress varied in the range 832 kA/m. By taking into account the variants sizes and their mutual interactions, we explained the observed dependence of the switching field on the location of the boundary. The resulting match...

  14. Effect of Mn Concentration on Magneto-mechnaical Properties in Directionally Solidified Ferromagnetic Shape Memory Ni-Mn-Ga Alloys

    Directory of Open Access Journals (Sweden)

    R.K Singh

    2016-06-01

    Full Text Available Heusler type alloys Ni50Mn25+xGa25-x  (x=2,3,4 and 5 based on near stoichiometric Ni2MnGa compositions were directionally solidified using modified Bridgman method. The alloys thus prepared were characterized for their chemical composition, crystal structure, microstructure, phase transformation, magnetic  and magneto-mechanical properties. The directionally solidified Ni50Mn30Ga20 alloy rod exhibited maximum magnetocrystalline value of 95 kJm-3 and lowest detwinning stresses for martensite phase of about 5MPa. The reversible room temperature magnetic field induced strain of 0.2% under external magnetic field of 0.6T and 0.05kN bias load was obtained for the directionally solidified Ni50Mn30Ga20 alloy.

  15. Domain model for the magnetic shape-memory effect in non-modulated tetragonal Ni-Mn-Ga

    Energy Technology Data Exchange (ETDEWEB)

    Onisan, A T; Bogdanov, A N; Roessler, U K, E-mail: u.roessler@ifw-dresden.de [IFW Dresden, Postfach 270116, D-01171 Dresden (Germany)

    2011-07-06

    We employ a general phenomenological domain theory for ferromagnetic shape memory (FSM) materials to model equilibrium domain states in martensites with tetragonal twin variants having axes ratios c/a > 1 and easy-plane magnetic anisotropy. The model is evaluated for realistic material parameters of non-modulated (NM) Ni{sub 2}MnGa alloys. Phase diagrams under competing external stresses and magnetic fields are presented that show regions of fully magnetized single-variant states and various multiphase regions. The theoretical elastic stresses that block single-variant states are found to be much smaller in NM than in the 5M structure of Ni{sub 2}MnGa alloys.

  16. Effect of Heat-Treatment on the Phases of Ni-Mn-Ga Magnetic Shape Memory Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Huq, Ashfia [ORNL; Ari-Gur, Pnina [Western Michigan University; Kimmel, Giora [University of the Negev; Richardson, James W [Argonne National Laboratory (ANL); Sharma, Kapil [Indian Institute of Technology, Kanpur

    2009-01-01

    The Heusler alloys Ni50Mn25+xGa25-x display magnetic shape memory effect (MSM) with very fast and large reversible strain under magnetic fields. This large strain and the speed of reaction make MSM alloys attractive as smart materials. Our crystallographic investigation of these alloys, focused on non-stoichiometric composition with excess of manganese. Using neutron diffraction, we revealed the necessary processing parameters to achieve and preserve the homogeneous metastable one-phase martensitic structure that is needed for an MSM effect at room temperature.

  17. Fabrication and characterization of a Ni-Mn-Ga uniaxially textured freestanding film deposited by DC magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Tillier, J., E-mail: jeremy.tillier@grenoble.cnrs.f [Institut Neel/Consortium de Recherche pour l' Emergence de Technologies Avancees, Centre National de la Recherche Scientifique, 25 avenue des Martyrs, BP166, 38042 Grenoble Cedex 9 (France); Bourgault, D.; Barbara, B.; Pairis, S.; Porcar, L.; Chometon, P.; Dufeu, D. [Institut Neel/Consortium de Recherche pour l' Emergence de Technologies Avancees, Centre National de la Recherche Scientifique, 25 avenue des Martyrs, BP166, 38042 Grenoble Cedex 9 (France); Caillault, N.; Carbone, L. [Schneider Electric France, 38TEC/T1, 37 quai Paul Louis Merlin, 38050 Grenoble Cedex 9 (France)

    2010-01-21

    Homogeneous freestanding films have been obtained by the direct current (DC) magnetron sputtering technique using a sacrificial layer. After annealing, the films are crystallized with a strong out-of-plane texture along the (0 2 2) direction. The stoichiometry of the annealed films is close to the target composition and leads to a martensitic transformation around 255 K. The annealed films demonstrate ferromagnetic behavior with a Curie temperature of about 362 K. The magnetization process has been studied on the both states and during the martensitic transition. The saturation magnetizations have been determined by fitting the experimental data with a saturation approach law in the range of 1-5 T. Results show the saturation magnetization of the martensite is around 10% higher than that of the austenite. A model based on intrinsic magnetic properties of each state allowing the description of the magnetization M = f(H, T) of such polycrystalline films during the martensitic transformation is presented. The mass fraction of martensite inside the austenite phase can be determined using this model. The shape memory effect is analyzed both by scanning electron microscopy and by optical microscopy with in situ measurement of the resistance temperature dependence.

  18. The effects of alloying elements Al and In on Ni-Mn-Ga shape memory alloys, from first principles.

    Science.gov (United States)

    Chen, Jie; Li, Yan; Shang, Jia-Xiang; Xu, Hui-Bin

    2009-01-28

    The electronic structures and formation energies of the Ni(9)Mn(4)Ga(3-x)Al(x) and Ni(9)Mn(4)Ga(3-x)In(x) alloys have been investigated using the first-principles pseudopotential plane-wave method based on density functional theory. The results show that both the austenite and martensite phases of Ni(9)Mn(4)Ga(3) alloy are stabilized by Al alloying, while they become unstable with In alloying. According to the partial density of states and structural energy analysis, different effects of Al and In alloying on the phase stability are mainly attributed to their chemical effects. The formation energy difference between the austenite and martensite phases decreases with Al or In alloying, correlating with the experimentally reported changes in martensitic transformation temperature. The shape factor plays an important role in the decrease of the formation energy difference.

  19. Phase Transformation Behaviors and Effects of Terbium in Polycrystalline Ni-Mn-Ga Magnetic Shape Memory Alloys

    Institute of Scientific and Technical Information of China (English)

    赵增祺; 熊玮; 吴双霞; 王新林

    2004-01-01

    The phase transformation behaviors of two kinds of magnetic shape memory alloys Ni50Mn25+xGa25-x and Ni50Mn29Ga21-xTbx were studied. When the composition of Ni in these alloys was constant, increasing Mn and reducing Ga contents make martensitic transformation temperatures rise obviously. Simultaneously, thermal hysteresis of phase transformation reduce but Curie temperature unalters. When terbium was added, phase transformation temperature went up further and Curie temperature kept constant. The alloys still show strong ferromagnetism and properties of thermoelastic martensite phase transformation.

  20. Crystal structure and macrotwin interface of five-layered martensite in Ni-Mn-Ga magnetic shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Y. [Laboratory of Materials Science, Helsinki University of Technology, P.O. Box 6200, FI 02015 (Finland)]. E-mail: Yanling.Ge@tkk.fi; Jiang, H. [VTT Processes, Aerosol Technology Group, P.O. Box 1602, 02044 VTT (Finland); Sozinov, A. [Laboratory of Materials Science, Helsinki University of Technology, P.O. Box 6200, FI 02015 (Finland); Soederberg, O. [Laboratory of Materials Science, Helsinki University of Technology, P.O. Box 6200, FI 02015 (Finland); Lanska, N. [Laboratory of Materials Science, Helsinki University of Technology, P.O. Box 6200, FI 02015 (Finland); Keraenen, J. [Centre for Electron Microscopy, Tampere University of Technology, P.O. Box 589, 33101 Tampere (Finland); Kauppinen, E.I. [VTT Processes, Aerosol Technology Group, P.O. Box 1602, 02044 VTT (Finland); New Materials Center, Helsinki University of Technology, 02044 VTT (Finland); Lindroos, V.K. [Laboratory of Materials Science, Helsinki University of Technology, P.O. Box 6200, FI 02015 (Finland); Hannula, S.-P. [Laboratory of Materials Science, Helsinki University of Technology, P.O. Box 6200, FI 02015 (Finland)

    2006-11-25

    The crystal structure of the five-layered (5M) martensite and the martensite to martensite interface in the alloys Ni{sub 48.9}Mn{sub 30.8}Ga{sub 20.3} and Ni{sub 49.5}Mn{sub 28.6}Ga{sub 21.9} (numbers indicate at.%) were investigated by the X-ray diffraction as well as by the conventional and by the high resolution transmission electron microscopy (HRTEM). The martensite to martensite interface arises from meeting of growth fronts of two microtwin sequences with the twin planes (110) and (11-bar 0), respectively. The interface was found to consist of two different configurations, the crossing and the step type. The HRTEM images reveal that the martensitic structure is not a perfect five-layered structure, but there are also other periodic structures (seven-layered and ten-layered), together with aperiodic structure and the irregular plane faults.

  1. Numerical modelling of fine-grained sediments remobilization in heavily polluted streams. Case study: Elbe and Bílina River, Czech Republic.

    Science.gov (United States)

    Kaiglová, Jana; Langhammer, Jakub; Jiřinec, Petr; Janský, Bohumír; Chalupová, Dagmar

    2014-05-01

    river and the riparian sediment evaluation the 2D schematization (MIKE 21 C) was selected. It enabled to distinguish flow characteristics in the zone with complicated hydrodynamic conditions. The risk of remobilization of fine-grained sediments was evaluated in order to define a threshold discharge value after that the spreading of pollution can be expected. The major contribution of the study, realized in the framework of international iniciative ELSA was the identification of threshold values for potential remobilization of sediment burdened by old loads in different environments. These threshold values are important information for identification and mitigation of risks related with old loads and hydrological extremes. From methodological point of view the study verified validity of applied distinct approaches for fine-grained sediment remobilization assessment and identified limits for their application. Key words: sediment, remobilization, old loads, modelling, hydrodynamics, Elbe river

  2. Significance of fine-grained microfabrics from a Cretaceous stromatolite bed (Muñecas Fm, late Turonian, Northern Iberian Ranges, Spain)

    Science.gov (United States)

    Rodríguez-Martínez, Marta; Reitner, Joachim; Gil, Javier; García-Hidalgo, José; Segura, Manolo

    2010-05-01

    A fine-grained stromatolite bed of great lateral continuity (km scale) and small synoptic relief (from 15 cm up to 40 cm) is registered in the Muñecas Formation (Floquet et al., 1982), of the Northern Iberian Ranges. Muñecas Fm is mainly composed of thin-bedded limestones and marls deposited during the late Turonian. At this time, the Iberian microplate was located in subtropical palaeolatitudes (20°N-30°N according Dercourt et al., 2000) and shallow-water carbonate platform facies were deposited in a wide and shallow seaway, along a NW-SE trending, intracratonic basin (Upper Cretaceous Iberian basin), between the emergent areas of the Hesperian massif to the W and the Ebro massif to the NE (Segura et al 2002). The stromatolite bed (facies 2.1) overlies heterolithic facies (facies 1.1) composed of marls and thin-bedded, massive mudstones with micritic intraclasts, ostracods and reworked sponges, and bearing quartz-silt and bioclastic-rich wavy bands. The coeval facies, laterally equivalent to the stromatolite bed, consist of an oolite-rich, sheet-like deposit (facies 2.2). Packstone and grainstone of radial-fibrous oolites overlie burrowed bioclastic mudstone-wackestones (facies 1.2) with bivalve fragments, gastropods, foraminifers, and sponges. The stromatolite bed is capped by ostracod-rich limestones (facies 3) and marls. The stromatolite posses a stratiform to LLH macrostructure, and in some places domed bioherms up to 1 m width occur. Internally, mesostructure is composed by planar, wavy to hemispherical stromatoids. They display a broad spectrum of microestructures: dense micrite, peloids (microbial as well as bahamite peloids), clotted microfabrics, irregular micritic-wall tubes and dendroid-arborescent microframeworks (filamentous cyanobacteria?). The microfacial study of the vertical arrangement of the stromatolite laminae reveals different growth stages probably related with environmental changes. In fact, the whole fine-grained stromatolite accretion

  3. Distribution of moderately volatile trace elements in fine-grained chondrule rims in the unequilibrated CO3 chondrite, ALH A77307.

    Science.gov (United States)

    Brearley, A J; Bajt, S; Sutton, S R

    1995-10-01

    The concentrations of Ni, Cu, Zn, Ga, Ge, and Se in five, fine-grained chondrule rims in the highly unequilibrated CO3 chondrite ALH A77307 (3.0) have been determined for the first time by synchrotron X-ray fluorescence (SXRF) microprobe at Brookhaven National Laboratory. These elements are especially useful for tracing the role of condensation and evaporation processes which occurred at moderate temperatures in the solar nebula. Understanding the distribution of moderately volatile elements between matrix and chondrules is extremely important for evaluating the different models for the volatile depletions in chondritic meteorites. The data show that the trace element chemistry of rims on different chondrules is remarkably similar, consistent with data obtained for the major and minor elements by electron microprobe. These results support the idea that rims are not genetically related to individual chondrules, but all sampled the same reservoir of homogeneously mixed dust. Of the trace elements analyzed, Zn and Ga show depletions relative to CI chondrite values, but in comparison with bulk CO chondrites all the elements are enriched by approximately 1.5 to 3.5 x CO. The abundance patterns for moderately volatile elements in ALH A77307 chondrule rims closely mimic those observed in the bulk chondrite, indicating that matrix is the major reservoir for these elements. The close matching of the patterns for the volatile depleted bulk chondrite and enriched matrix is especially striking for Na, which is anomalously depleted in ALH A77307 in comparison with average CO chondrite abundances. The depletion in Na is probably attributable to the effects of leaching in Antarctica. With the exception of Na, the volatile elements show a relatively smooth decrease in abundance as a function of condensation temperature, indicating that their behavior is largely controlled by their volatility.

  4. Research on Fine-grained Fuzzy Trust Chain of Trusted Computing%可信计算之细粒度模糊信任链研究

    Institute of Scientific and Technical Information of China (English)

    李强; 牛文生

    2014-01-01

    This paper focuses on the realization of the trust chain for trusted computing platform technolo-gy.On the basis of the research on correlation between trustand security ,it sums up several issues exist in the trust chain technology ,that are worth exploring ,and analyzes the relationship between trustand securi-ty,the differences between authentication chain and trust chain ,and the granularity of components divi-sion.This paper raises a fine-grained model of fuzzy trust chain ,and puts the study on principles of the components division ,component and system security measurement and trust transfer theory in depth .The paperprovides a feasible solution to the study on trust of trusted computing ,and has an important practical significance to the trust and securityresearch of actual system .%针对可信计算平台信任链技术的实现,在可信与安全相关性研究基础上,总结了信任链技术中存在的几个值得探讨的问题,对可信与安全的关系、认证链和信任链的区别以及组件划分的粒度等问题进行了分析。提出了一种细粒度模糊信任链模型,对组件划分原则、组件、系统的安全度量方法和信任转移理论进行了深入研究。为可信计算信任问题的研究提供了一个可行的方案,对实际系统可信性和安全性研究具有参考意义。

  5. Water-saving technologies affect the grain characteristics and recovery of fine-grain rice cultivars in semi-arid environment.

    Science.gov (United States)

    Jabran, Khawar; Riaz, Muhammad; Hussain, Mubshar; Nasim, Wajid; Zaman, Umar; Fahad, Shah; Chauhan, Bhagirath Singh

    2017-05-01

    Growing rice with less water is direly needed due to declining water sources worldwide, but using methods that require less water inputs can have an impact on grain characteristics and recovery. A 2-year field study was conducted to evaluate the impact of conventionally sown flooded rice and low-water-input rice systems on the grain characteristics and recovery of fine rice. Three fine grain rice cultivars-Super Basmati, Basmati 2000, and Shaheen Basmati-were grown under conventional flooded transplanted rice (CFTR), alternate wetting and drying (AWD), and aerobic rice systems. Grain characteristics and rice recovery were significantly influenced by different water regimes (production systems). Poor milling, including the lowest percentage of brown (head) rice (65.3%) and polished (white) rice (64.2-66.9%) and the highest percentage of broken brown rice (10.2%), husk (24.5%-26.3%), polished broken rice (24.7%), and bran (11.0-12.5%), were recorded in the aerobic rice system sown with Shaheen Basmati. With a few exceptions, cultivars sown in CFTR were found to possess a higher percentage of brown (head) and polished (white) rice and they had incurred the least losses in the form of brown broken rice, husk, polished broken rice, and bran. In conclusion, better grain quality and recovery of rice can be attained by growing Super Basmati under the CFTR system. Growing Shaheen Basmati under low-water-input systems, the aerobic rice system in particular, resulted in poor grain characteristics tied with less rice recovery.

  6. The importance of fine-grained channel margin (FGCM) deposits in assessing the multiple residence times of suspended sediment and contaminants in gravel-bed rivers

    Science.gov (United States)

    Skalak, K. J.; Pizzuto, J. E.

    2008-12-01

    We have found that fine-grained channel margin (FGCM) deposits conditioned by large woody debris (LWD) are a significant component of sediment budgets in agricultural watersheds. By volume, the deposits store about 28 percent of the annual suspended sediment load. Radiocarbon, Pb-210, and Cs-137 analyses indicate a range of sediment ages (1 year to several decades). Reservoir theory analysis indicates an average turnover time of 1.5 years and an annual mass flux equivalent to 5 percent of the annual sediment load. The power function that best fits the transit time distribution suggests that there are multiple transit times and that most sediment in the deposits is reworked on short timescales, but a portion remains in place for several decades or more. The presence of a long tail in the distribution suggests anomalous transport, which indicates a well-developed framework for subsurface contaminant transport, continuous time random walks (CTRW), could be utilized for suspended sediment transport and contaminants associated with suspended sediment. South River has a history of mercury (Hg) contamination from an industrial release that occurred 1930-1950. The distribution of ages and Hg concentrations suggest that approximately 10 percent of the sediment and 75 percent of the Hg in the deposits dates from the release period. If the sediment in FGCM deposits has been transported primarily in suspension then we can reconstruct the loading history of Hg from the plant and predict that centuries will be required to remove this material. Our approach can be generalized to assess storage of sediments and contaminants in other gravel-bed rivers.

  7. An assessment of geochemical preparation methods prior to organic carbon concentration and carbon isotope ratio analyses of fine-grained sedimentary rocks

    Science.gov (United States)

    KöNitzer, Sven F.; Leng, Melanie J.; Davies, Sarah J.; Stephenson, Michael H.

    2012-09-01

    This study summarizes organic carbon isotope (δ13C) and total organic carbon (TOC) data from a series of tests undertaken to provide an appropriate methodology for pre-analysis treatment of mudstones from an Upper Carboniferous sedimentary succession, in order to develop a consistent preparation procedure. The main treatments involved removing both inorganic carbonate and hydrocarbons (which might be extraneous) before δ13C and TOC analysis. The results show that decarbonating using hydrochloric acid causes significant reduction in δ13C and total carbon (TC) of the bulk material due to the removal of inorganic carbonate. These changes are most pronounced where soluble calcium carbonate (rather than Ca-Mg-Fe carbonate) is present. Deoiled samples show only slightly higher mean δ13C where visible bitumen was extracted from the bulk sample. Moreover, the isotopic signatures of the extracts are closely correlated to those of their respective bulk samples, suggesting that small yields of hydrocarbons were generated in situ with no isotopic fractionation. In addition, further δ13C and TC analyses were performed on samples where mixing of oil-based drilling mud with brecciated core material had been undertaken. Brecciated mudstone material did not display distinct isotopic signals compared to the surrounding fine-grained material. Overall we show that the most accurate assessment of bulk organic carbon isotopes and concentration in these samples can be achieved through decarbonating the material prior to measurement via the `rinse method'. However, our results support recent findings that pre-analysis acid treatments can cause variable and unpredictable errors in δ13C and TOC values. We believe that, despite these uncertainties, the findings presented here can be applied to paleoenvironmental studies on organic matter contained within sedimentary rocks over a range of geological ages and compositions.

  8. 21 CFR 888.3353 - Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented or nonporous uncemented prosthesis. 888.3353 Section 888.3353 Food and Drugs FOOD AND DRUG... prosthesis. (a) Identification. A hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis is a device intended to be implanted to replace a hip joint. This device...

  9. XRD-based 40Ar/39Ar age correction for fine-grained illite, with application to folded carbonates in the Monterrey Salient (northern Mexico)

    Science.gov (United States)

    Fitz-Díaz, Elisa; Hall, Chris M.; van der Pluijm, Ben A.

    2016-05-01

    of retention capability, degassing spectra were modeled for site XCA averages and overall XCA average. Modeling shows that local site age average best match the measured spectra, instead of a global average age, indicating that illite growth reflects local deformation, and is not the result of regional metamorphism. Modeling also shows that Ar-degassing spectra are very sensitive to grain size, such that age interpretation based on Ar-plateaus is meaningless for most fine-grained clays.

  10. Multi-Scale Transport Properties of Fine-Grained Rocks: A Case Study of the Kirtland Formation, San Juan Basin, USA

    Science.gov (United States)

    Heath, J. E.; Dewers, T. A.; McPherson, B. J.; Wilson, T. H.; Flach, T.

    2009-12-01

    Understanding and characterizing transport properties of fine-grained rocks is critical in development of shale gas plays or assessing retention of CO2 at geologic storage sites. Difficulties arise in that both small scale (i.e., ~ nm) properties of the rock matrix and much larger scale fractures, faults, and sedimentological architecture govern migration of multiphase fluids. We present a multi-scale investigation of sealing and transport properties of the Kirtland Formation, which is a regional aquitard and reservoir seal in the San Juan Basin, USA. Sub-micron dual FIB/SEM imaging and reconstruction of 3D pore networks in core samples reveal a variety of pore types, including slit-shaped pores that are co-located with sedimentary structures and variations in mineralogy. Micron-scale chemical analysis and XRD reveal a mixture of mixed-layer smectite/illite, chlorite, quartz, and feldspar with little organic matter. Analysis of sub-micron digital reconstructions, mercury capillary injection pressure, and gas breakthrough measurements indicate a high quality sealing matrix. Natural full and partially mineralized fractures observed in core and in FMI logs include those formed from early soil-forming processes, differential compaction, and tectonic events. The potential impact of both fracture and matrix properties on large-scale transport is investigated through an analysis of natural helium from core samples, 3D seismic data and poro-elastic modeling. While seismic interpretations suggest considerable fracturing of the Kirtland, large continuous fracture zones and faults extending through the seal to the surface cannot be inferred from the data. Observed Kirtland Formation multi-scale transport properties are included as part of a risk assessment methodology for CO2 storage. Acknowledgements: The authors gratefully acknowledge the U.S. Department of Energy’s (DOE) National Energy Technology Laboratory for sponsoring this project. The DOE’s Basic Energy Science

  11. Capillary liquid chromatography separations using non-porous pillar array columns

    NARCIS (Netherlands)

    de Malsche, Wim; de Bruyne, S.; op de Beek, J.; Sandra, P.; Gardeniers, Johannes G.E.; Desmet, G.; Lynen, F.

    2012-01-01

    We report on a series of explorative experiments wherein a non-porous pillar array column (NP-PAC) is coupled to a commercial capillary LC instrument. The performance of the system was evaluated by both non-retained and retained experiments using several types of samples. In order to minimize

  12. Evaporation of HD Droplets From Nonporous, Inert Surfaces in TGA Microbalance Wind Tunnels

    Science.gov (United States)

    2008-09-01

    2007 4. TITLE AND SUBTITLE Evaporation of HD Droplets from Nonporous, Inert Surfaces in TGA Microbalancc Wind Tunnels 5a. CONTRACT NUMBER DAAD13...hr (lightly swirled on a rotating plateau). Then, the glass was rinsed with dematerialized water and dried (using appropriate fat-free non-felting

  13. Capillary liquid chromatography separations using non-porous pillar array columns

    NARCIS (Netherlands)

    Malsche, de D.M.W.; Bruyne, de S.; Beek, op de J.; Sandra, P.; Gardeniers, J.G.E.; Desmet, G.; Lynen, F.

    2012-01-01

    We report on a series of explorative experiments wherein a non-porous pillar array column (NP-PAC) is coupled to a commercial capillary LC instrument. The performance of the system was evaluated by both non-retained and retained experiments using several types of samples. In order to minimize interf

  14. 基于XML Schema的细粒度SoC设计复用方法%An XML Schema based fine-grained SoC reuse methodology

    Institute of Scientific and Technical Information of China (English)

    孟昕; 沈海斌; 严晓浪

    2011-01-01

    针对传统的基于模块复用的SoC可复用设计方法学在面对结构复用或抽象内容复用时效率低、设计迭代代价高的缺陷,提出基于XML Schema的细粒度设计复用方法(FGRX),扩充了传统可复用设计方法学,通过分析现有设计把更小的逻辑结构、代码片段和抽象内容吸纳为可复用对象,并基于可复用对象构建设计原语集和复用规则集.FGRX用XML Schema对原语集和复用规则集完成形式化定义,同类设计或同一产品线中的类似芯片设计描述在原语级以XML格式完成.利用XML Validator自动构建基于复用规则集的原语级描述校验器,对设计描述完成静态结构检查.利用XSLT设计转换规则,把由可复用对象组成的原语级设计描述转换成各种标准格式的设计文件,并在转换过程中实现细致的语义检查,进一步校验模型描述.以一个实际应用具体讨论了FGRX的应用过程,实际应用结果证明:FGRX能充分复用现有工作成果、高效可靠地完成同类模块的设计或同一产品线中同类芯片的开发、大规模精简描述代码、减少设计者重复劳动的工作量以及提升工作效率.%Traditional module based reuse methodology for SoC design has low efficiency and high iterationcost when faced with reuse of structure and abstract contents. This work proposed a fine-grained reusable design methodology based on XML schema(FGRX) as an extension to traditional methodology.Smaller logic blocks, code snippets and abstract contents are abstracted as reusable objects through analysis of existingdesign, which can be further used to construct a primitive set. Inter-dependencies between abstract reusable objects are organized in reusing rules set. Primitive set and reusing rule set are formally defined using XML schema. Similar designs are described at primitive level in XML format, which is statically validated by a checker that is automatically generated by XML validator

  15. 细结构产品浸渍工序质量稳定性控制%Quality and stability controls of pitch impregnation for fine grain graphite products

    Institute of Scientific and Technical Information of China (English)

    曹曙林

    2011-01-01

    The factors affecting the quality and stability controls of pitch impregnation for fine grain graphite products were brief summarized and discussed from the view of the raw material, conditions, and the process of impregnation.%简要概括细结构产品浸渍工序中质量稳定性控制的影响因素,并对浸渍工序中原料、条件、过程因素及其对浸渍工序的影响作简要的分析探讨.

  16. Preparation of A-type zeolite membranes on nonporous metal supports by using electrophoretic technique

    Institute of Scientific and Technical Information of China (English)

    HUANG Aisheng; LIU Jie; LI Yanshuo; LIN Yuesheng; YANG Weishen

    2004-01-01

    A-type zeolite membranes were prepared onthe nonporous metal supports by using electrophoretic tech-nique. The as-synthesized membranes were characterized byXRD and SEM. The effect of the applied potential on theformation of the A-type zeolite membrane was investigated,and the formation mechanism of zeolite membrane in theelectric field was discussed. The results showed that thenegative charged zeolite particles could migrate to the anodemetal surface homogenously and rapidly under the action ofthe applied electric field, consequently formed uniform anddense membranes in short time. The applied potential hadgreat effect on the membrane formation, and more uniformand denser zeolite membranes were prepared on the non-porous metal supports with 1 V potential.

  17. Consideration on buckling and plastic breakdown strength characteristics of a steel plate with surface layers of ultra fine grain microstructure (SUF); Hyoso chosairyu koban no zakutsu sosei hokai kyodo tokusei ni kansuru ichikosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, M.; Yao, T.; Yajima, H.; Miyamoto, H.; Morita, S. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering; Ogihara, Y.; Ishikawa, T. [Nippon Steel Corp., Tokyo (Japan)

    1996-10-01

    Buckling and plastic breakdown strength characteristics of a structure fabricated by using new steel plates with surface layer made into ultra fine grain structure were analyzed and discussed by using a belt plate buckling and plasticity test and the finite element method. The tested steel plate has a thickness of 25 mm, and was fabricated for ocean vessel use, with surface layers on both sides of about 1/6 of the whole thickness having been made an ultra fine grain structure. As a result of a belt steel buckling and plasticity test on a steel plate with surface ratio of 29%, both of the initial yield stress and the buckling stress were found increased by about 4 to 10% as compared with a steel plate having surface ratio of 0%. An analysis by using the finite element method was made on square steel plates with a length of 80 cm, a width of 100 cm, and thicknesses of 12 mm and 24 mm. A result was obtained that, in the case of surface layer ratio of 33%, both of the initial yield stress and the maximum load withstanding force were higher by 5 to 16% than the case of surface ratio of 0%. Similar rise in strength was shown also in bend preventing plates which are basic constituting members of a vessel. 6 refs., 10 figs., 2 tabs.

  18. A Delegation-Supported & Fine-Grained Access Control Model Based on Role%支持授权委托的细粒度角色访问控制模型

    Institute of Scientific and Technical Information of China (English)

    向华萍; 付智辉; 胡林峰

    2011-01-01

    For improving of permission management and access control in complex integrated system, an extended role-based access control model is proposed which supports delegation and fine-grained access control. The model decomposes objects to less granularities by purpose of subjects and defines role attributes to realize fine-grained access control, appends time constrains to strengthen capacity of constraints for roles, permissions and delegation, and introduces delegation mechanism and role groups to solve the complexity and centralization questions of inte grated system.%针对传统RBAC模型在大型综合集成系统中的权限管理以及访问控制的不足,从授权委托和访问控制的细粒度方面对RBAC模型进行扩充,通过将客体资源按主体的意图以尽量小的粒度分解和设置角色属性以实现细粒度的访问控制,附加时间约束来增强模型对角色、权限、委托等的约束能力,并且引入授权委托机制以及角色组的概念,解决了综合系统授权管理的复杂性和集中性问题.

  19. On the microstructural and magnetic properties of fine-grained CoFe{sub 2}O{sub 4} ceramics produced by combining polyol process and spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Gaudisson, T.; Artus, M. [Laboratoire ITODYS, Université Paris-Diderot, Sorbonne Paris Cité, CNRS-UMR-7086, 7205 Paris (France); Acevedo, U. [Departamento MMC, Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, 04510 Ciudad de México (Mexico); Herbst, F.; Nowak, S. [Laboratoire ITODYS, Université Paris-Diderot, Sorbonne Paris Cité, CNRS-UMR-7086, 7205 Paris (France); Valenzuela, R. [Departamento MMC, Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, 04510 Ciudad de México (Mexico); Ammar, S., E-mail: ammarmer@univ-paris-diderot.fr [Laboratoire ITODYS, Université Paris-Diderot, Sorbonne Paris Cité, CNRS-UMR-7086, 7205 Paris (France)

    2014-12-15

    Starting from polyol-made CoFe{sub 2}O{sub 4} ferrite nanoparticles of different aggregation states, high-density fine-grained ceramics were produced using Spark Plasma Sintering technique at 600 and 500 °C, under vacuum and applying a uniaxial pressure of more than 80 MPa. The grain growth of thus produced ceramics appears to be proportional to the temperature plateau and inversely proportional to the aggregation state of the initial powders. Average grain sizes ranging between about 50 and 350 nm were obtained. In all the cases, magnetic measurements evidenced a ferrimagnetic behavior at room temperature with non-zero coercivity, while their starting powders exhibited superparamagnetic features. - Highlights: • CoFe{sub 2}O{sub 4} nanoparticles of different aggregation states were produced in polyol. • Dense and fine-grained CoFe{sub 2}O{sub 4} ceramics were produced by SPS starting from these nanoparticles. • The CoFe{sub 2}O{sub 4} grain growth during SPS appears to be mainly driven by diffusion mechanism. • The ceramics are ferrimagnetic at 300 K while their starting powders are superparamagnetic.

  20. Use of quantum dots in aqueous solution to detect blood fingermarks on non-porous surfaces.

    Science.gov (United States)

    Becue, Andy; Moret, Sébastien; Champod, Christophe; Margot, Pierre

    2009-10-30

    A new and original reagent based on the use of highly fluorescent cadmium telluride (CdTe) quantum dots (QDs) in aqueous solution is proposed to detect weak fingermarks in blood on non-porous surfaces. To assess the efficiency of this approach, comparisons were performed with one of the most efficient blood reagents on non-porous surfaces, Acid Yellow 7 (AY7). To this end, four non-porous surfaces were studied, i.e. glass, transparent polypropylene, black polyethylene, and aluminium foil. To evaluate the sensitivity of both reagents, sets of depleted fingermarks were prepared, using the same finger, initially soaked with blood, which was then successively applied on the same surface without recharging it with blood or latent secretions. The successive marks were then cut in halves and the halves treated separately with each reagent. The results showed that QDs were equally efficient to AY7 on glass, polyethylene and polypropylene surfaces, and were superior to AY7 on aluminium. The use of QDs in new, sensitive and highly efficient latent and blood mark detection techniques appears highly promising. Health and safety issues related to the use of cadmium are also discussed. It is suggested that applying QDs in aqueous solution (and not as a dry dusting powder) considerably lowers the toxicity risks.

  1. Fingerprint detection and using intercalated CdSe nanoparticles on non-porous surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Algarra, Manuel, E-mail: malgarra67@gmail.com [Centro de Geología da Universidade do Porto, Departamento de Geociências, Ambiente e Ordenamemto do Territorio do Porto, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Radotić, Ksenija; Kalauzi, Aleksandar; Mutavdžić, Dragosav; Savić, Aleksandar [Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11000 Beograd (Serbia); Jiménez-Jiménez, José; Rodríguez-Castellón, Enrique [Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, 29071Málaga (Spain); Silva, Joaquim C.G. Esteves da [Centro de Investigação em Química (CIQ-UP). Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Guerrero-González, Juan José [Policía Científica, Cuerpo Nacional de Policía, Málaga (Spain)

    2014-02-17

    Graphical abstract: -- Highlights: •Fluorescent nanocomposite based on the inclusion of CdSe quantum dots in porous phosphate heterostructures. •Characterized by FTIR, XRD and fluorescence spectroscopies. •Deconvolution of the emission spectra was confirmed by using multivariate curve resolution (MCR) method. •Application for fingerprint detection and analysis on different non-porous surfaces. -- Abstract: A fluorescent nanocomposite based on the inclusion of CdSe quantum dots in porous phosphate heterostructures, functionalized with amino groups (PPH-NH{sub 2}@CdSe), was synthesized, characterized and used for fingerprint detection. The main scopes of this work were first to develop a friendly chemical powder for detecting latent fingerprints, especially in non-porous surfaces; their further intercalation in PPH structure enables not to spread the fluorescent nanoparticles, for that reason very good fluorescent images can be obtained. The fingerprints, obtained on different non-porous surfaces such as iron tweezers, mobile telephone screen and magnetic band of a credit card, treated with this powder emit a pale orange luminescence under ultraviolet excitation. A further image processing consists of contrast enhancement that allows obtaining positive matches according to the information supplied from a police database, and showed to be more effective than that obtained with the non-processed images. Experimental results illustrate the effectiveness of proposed methods.

  2. 不同胶凝材料的精细混凝土高温后力学性能%MECHANICAL PROPERTY OF FINE GRAINED CONCRETE WITH DIFFERENT CEMENTING MATERIAL AFTER EXPOSURE TO HIGH-TEMPERATURE

    Institute of Scientific and Technical Information of China (English)

    沈玲华; 王激扬; 徐世烺; 付晔

    2015-01-01

    为了改善用于纤维编织网增强混凝土基体材料的精细混凝土的耐高温性能,该文进行了120个40mim×40mm×160mm棱柱体的高温后抗折强度试验和240个40mm×40mm×40mm立方体的高温后抗压强度试验.考察了不同胶凝材料对精细混凝土试件高温后力学性能的影响,包括外掺纳米材料以及以高铝水泥作为主要胶凝材料的影响.结果表明:体积掺量为1.5%和3.0%纳米SiO2气凝胶粉末未能改善精细混凝十的耐高温性能,质量掺量为5.0%纳米陶瓷粉在目标温度TR=800℃时使基体混凝土的抗压和抗折强度分别提高84.2%和120.9%.当TR=800℃时,采用高铝水泥作为主要胶凝材料的试件力学性能均比普通精细混凝土试件大幅提高;各组掺入活性粉末的高铝水泥混凝土试件在TR=800℃时,相对抗压和抗折强度均比未掺活性粉末时有所提高.%To improve the high temperature resistance of fine grained concrete for textile reinforced concrete matrices,120 prism specimens (40mm×40mm×160mm) for flexural tests and 240 cube specimens (40mm×40mm×40mm) were prepared in this paper for compressive strength tests after exposure to high temperature.The effects of different cementing materials on mechanical properties of fine grained concrete were studied,including the effect of nanomaterial admixtures and the use of alumina cement as main cementing material.The results show that nanometer SiO2 aerogel powder cannot improve the high temperature resistance of fine grained concrete when volume fraction is 1.5% or 3.0%.Nanosized ceramic powder with quality content of 5.0% can improve the residual compressive and flexural strength of fine grained concrete by 84.2% and 120.9%,respectively,over that of concrete without nanosized ceramic powder at 800℃.When TR=800℃,mechanical properties of specimens with alumina cement as the main cementing material increase greatly compared with ordinary fine grained

  3. The coarse- to fine-grained boundary beneath the New England Mud Patch: evidence from seismic and core data for an abrupt post-transgressive change in hydrologic regime on the continental shelf

    Science.gov (United States)

    Goff, J.; Chaytor, J. D.; Reed, A. H.; Liu, S.; Wilson, P. S.; Knobles, D. P.

    2016-12-01

    The New England Mud Patch (NEMP) is an anomaly on the Atlantic coast of North America. This 13,000 km2 area, located south of Cape Cod between the 60 m and 160 m isobaths, is a region of active fine-grained deposition on a shelf that is predominantly non-depositional and even erosional in places. Prior studies theorized that NEMP sediments are derived from fines winnowed from Georges Bank, transported westward by coastal currents, and then settled in more quiescent conditions at the mud patch. A CHIRP seismic reflection (2015) and coring (2016) survey of the NEMP was conducted in support of a planned acoustic experiment for the Office of Naval Research. The survey focused on a 30 km (E-W) by 8 km (N-S) region between the 75 m and 85 m isobaths, encompassing a sediment "pond" up to 13 m thick. The dense (250 m) CHIRP survey lines allow a pseudo-3D stratigraphic interpretation. The sediment pond itself occupies an accommodation space that appears to have been eroded into substrate (Pleistocene?) sediments, perhaps by glacial processes. The interpreted transgressive ravinement is capped by marine sands organized into oblique sand ridge morphology. The sense of obliquity, morphologic asymmetry and internal dipping reflectors indicate that the sand ridges formed under an east-directed transport regime. However, as evidenced by prograding internal layering, NEMP deposition occurred under a west-directed transport regime, consistent with modern shelf conditions. The onset of fine-grained deposition was therefore contemporaneous with a significant shift in the hydrologic regime. Layer reflectivity increases with depth, likely indicating that terrestrial sources may have been more prominent in the early stages of NEMP deposition. Several cores penetrated the finer-grained sediment ("mud") to sand transition; analysis this Fall should help us to better understand this important transition.

  4. 新疆昆仑山北坡黄土细颗粒混合矿物IRSL,[post-IR]OSL和细颗粒石英OSL测年初步研究%PRELIMINARY STUDIES ON DATING USING IRSL AND [ POST-IR] OSL SIGNALS FROM FINE-GRAINED POLYMINERALS AND OSL SIGNAL FROM FINE-GRAINED QUARTZ IN LOESS AT NORTHERN SLOPE OF KUNLUN MTS.,XINJIANG

    Institute of Scientific and Technical Information of China (English)

    张克旗

    2012-01-01

    使用感量校正多测片再生(SMAR)法对新疆昆仑山北坡的12个黄土样品的细颗粒混合矿物和细颗粒石英进行了等效剂量(De)的测量.测试结果显示,该地区黄土的[ post-IR]OSL和OSL信号强度相对于黄土高原的样品偏低,初步认为与物源不同及粉尘堆积和堆积后经受的风化作用微弱有关.细颗粒混合矿物的IRSL等效剂量值基本上小于其细颗粒石英OSL的,反映出长石存在明显的异常衰减现象;[post-IR] OSL信号主要来自于长石,用于测年需谨慎;细颗粒石英OSL更适合用于对该地区黄土的测年.%The equivalent doses of fine-grained polymineials and OSL signal from fine-grained quartz were measured by using SMAR protocol to 12 loess samples from the northern slope of Kunlun Mts.,Xinjiang. 8 of the 12 samples were collected from a loess section, which is 84m thick and located in a terrace, southwest of Aqiang township (36°23'30"N,81°54'57"E;2670m a. s. 1. )in Yutian County,and the other 4 samples were collected from terraces (36°15'52"~36°16'35"N,81°29'28" ~ 81°30'35"E;2100 -2120m) at the west bank of the Keriya River. The results show that the intensities of [ post-IR ] OSL and OSL signals are lower than those of the loess samples from the Loess Plateau, which can be related preliminarily to the source differences between the two kinds of loess. It is also probable that the weak weathering of dust during accumulating and after accumulation make the intensity differences. These two factors resulted in the differences of the content and types of minerals between the two areas, as well as a different sensitivity of luminescence signals. The weak signals mean a low signal to noise ratio when a young sample is measured,which will make a low reliability of equivalent dose(De) .The obvious anomalous fading of IRSL signals from feldspars was observed,thus it must be cautious to use the signal to date a sample,which will result in a fact that its De is less

  5. Amine modification of nonporous silica nanoparticles reduces inflammatory response following intratracheal instillation in murine lungs.

    Science.gov (United States)

    Morris, Angie S; Adamcakova-Dodd, Andrea; Lehman, Sean E; Wongrakpanich, Amaraporn; Thorne, Peter S; Larsen, Sarah C; Salem, Aliasger K

    2016-01-22

    Amorphous silica nanoparticles (NPs) possess unique material properties that make them ideal for many different applications. However, the impact of these materials on human and environmental health needs to be established. We investigated nonporous silica NPs both bare and modified with amine functional groups (3-aminopropyltriethoxysilane (APTES)) in order to evaluate the effect of surface chemistry on biocompatibility. In vitro data showed there to be little to no cytotoxicity in a human lung cancer epithelial cell line (A549) for bare silica NPs and amine-functionalized NPs using doses based on both mass concentration (below 200μg/mL) and exposed total surface area (below 14m(2)/L). To assess lung inflammation, C57BL/6 mice were administered bare or amine-functionalized silica NPs via intra-tracheal instillation. Two doses (0.1 and 0.5mg NPs/mouse) were tested using the in vivo model. At the higher dose used, bare silica NPs elicited a significantly higher inflammatory response, as evidence by increased neutrophils and total protein in bronchoalveolar lavage (BAL) fluid compared to amine-functionalized NPs. From this study, we conclude that functionalization of nonporous silica NPs with APTES molecules reduces murine lung inflammation and improves the overall biocompatibility of the nanomaterial.

  6. Study of SiC Layer with Fine Grains in HTGR Coated Fuel Particles%HTGR 包覆燃料颗粒碳化硅层细晶化研究

    Institute of Scientific and Technical Information of China (English)

    刘荣正; 刘马林; 刘兵; 邵友林

    2015-01-01

    高温气冷堆(HTGR)是能适应未来能源市场的第四代先进核反应堆堆型之一,其固有安全性的第一道保障是使用的T RISO型包覆燃料颗粒。在T RISO型燃料颗粒4层包覆结构中,SiC包覆层是承受包覆燃料颗粒内压和阻挡裂变产物释放的关键层,制备高质量S iC包覆层是核燃料领域中的重大问题和关键技术之一。本文介绍高温气冷堆燃料颗粒的基本结构,详述制备S iC包覆层的流化床‐化学气相沉积过程,提出S iC层细晶化这一研究方向,并系统阐述包覆燃料颗粒S iC包覆层细晶化的优势。在细晶化S iC材料制备方法方面,系统分析S iC粉体、陶瓷、薄膜和厚膜材料的研究现状,并结合本实验室前期研究成果提出制备细晶S iC包覆层的可行制备策略。%High temperature gas‐cooled reactor (HTGR) with inherent safety character‐istics is considered as one of the attractive and competitive generation Ⅳ nuclear reactors in the future energy markets .Tristructural‐isotropic (TRISO)‐coated particle fuel is the most significant safety aspect in this nuclear reactor ,since it relies on the properties of the four coating layers surrounding the kernel fuel to hinder the release of harmful radio‐active material .Among these layers ,the silicon carbide (SiC) coating is considered the most important as it not only provides the TRISO particle with structural integrity but also retains fission products at elevated temperatures .The preparation of high quality SiC layers is one of significant issues and key technologies in nuclear fuel fabrication . T he basic structure of the T RISO‐coated fuel particles and the fluidized bed chemical vapor deposition (FBCVD) method to prepare SiC layers were introduced .The advanta‐ges of decreasing grain size of SiC layers were analyzed and the idea to prepare SiC layers with fine grain size was proposed .In the preparation strategies ,recent

  7. 预测细粒酒精模型冰物理和力学参数的实验关系%FORECAST EXPERIMENT RELATIONS OF THE PHYSICAL AND MECHANICAL PARAMETERS OF FINE GRAIN ETHANOL MODEL ICE

    Institute of Scientific and Technical Information of China (English)

    李志军; RISKA; Kaj

    2001-01-01

    Model ice is a necessary material in the physical simulation study of interaction between ice and structures (ships). Fine grain ethanol model ice is one of frozen grain model ices. At present, no single material that can modify natural ice properties suitably has been found because the present model ice properties change with the ice making technique and the ingredients. Therefore, the model ice properties become one of the main factors that dominate the simulation results. In practice, just a few parameters are modified following simulation rules based on the research purpose. Even though, the model ice thickness and the modified mechanical properties are not the same with the desired values. Since fine grain ethanol model ice come into beings, in model tests of ice and ships or structures desired properties were controlled by experience, true properties were measured before the tests, and model results were explained by modified parameters. How can model ice properties be controlled by using ice basin temperature, cold solid time and warm time as well as desire model ice thickness (water jumping rate>×time) which can be controlled in ice making procedures? That is the purpose of the study to answer this question. A series of detailed research on the ethanol freezing point (instead of ethanol percent), ice temperatures, ice basin air temperature, unfrozen liquid in model ice, ice density, ice compressive strength, ice flexural strength and ice strain modulus was done. The new index forecasting any kind of fine grain model ice parameters established based on the physical essence in ice making and measured model ice parameters. This paper provides the physical basis of the index and the experimental relationships between the index and each of the main physical and mechanical parameters of the ethanol modal ice.%依据模型冰物理性质控制其力学性质的原则,利用能量平衡观点建立了冰内未冻结液体含量同制冰过程中的冰池温度

  8. Fine-grained data integrity check methods for cell phone forensics%面向手机取证的细粒度数据完整性检验方法

    Institute of Scientific and Technical Information of China (English)

    赵亚杰; 陈龙

    2012-01-01

    手机取证过程中的多种动态性因素都会导致前后两次内存镜像不一致,从而影响获取证据的真实性和可采性.分析了手机内存中的数据变化规律,引入细粒度完整性检验方法对手机内存镜像中的数据对象按照细粒度分别进行完整性检验.结合各种案例选取不同数据对象作为证据的需求,将手机内存镜像数据划分为不同粒度的数据对象.该方法可以有效地隔离不同数据对象,使得在内存镜像变化难以避免的情况下,验证了取证镜像过程的可靠性,证明目标数据对象的完整性,从而保证作为证据的数据对象能够被法庭接受.%A variety of the dynamic factors in mobile phone forensics process can lead to inconsistencies in the back-to-back memory image, thus affecting the authenticity and admissibility of the evidence. The data variation in the phone memory is analyzed, according with the introduction of fine-grained method and the integrity of the data in the phone memory image objects is tested separately by fine-grained. Combining with different cases, select different data objects as evidence demand, and divide the phone memory image data into data objects of different size . This method can effectively isolate the different data objects, in the case of inevitable changes in memory image, verify the reliability of forensic image process and prove the integrity of the target data objects, thus ensuring data objects as evidence can be accepted by courts.

  9. CP-ABE Scheme Supporting Fully Fine-Grained Attribute Revocation%一种支持完全细粒度属性撤销的CP-ABE方案

    Institute of Scientific and Technical Information of China (English)

    王鹏翩; 冯登国; 张立武

    2012-01-01

    Attribute revocation is crucial to use of ABE. The existing ABE schemes that support attribute revocation under the direct revocation model can only revoke the whole attributes that the user possesses by revoking the user's identity, so the attribute revocation is coarse-grained. This paper proposes the model of CP-ABE that supports fully fine-grained attribute revocation. Based on the dual encryption system proposed by Waters, a concrete CP-ABE scheme that fully supports fine-grained attribute revocation is constructed over the composite order bilinear groups, and the study proves its security under the standard model. Compared to the existing related schemes, this scheme is much more flexible and can revoke an arbitrary number of attributes that user possesses.%属性撤销是基于属性的加密(attribute based encryption,简称ABE)在实际应用中所必须解决的问题.在直接撤销模式下,已有的支持属性撤销的ABE方案只能以撤销用户身份的方式对用户所拥有的全部属性进行撤销,而无法做到针对属性的细粒度撤销.提出了直接模式下支持完全细粒度属性撤销的CP-ABE(cipher policy ABE)模型,在合数阶双线性群上,基于双系统加密的思想构造了具体的方案,并在标准模型下给出了严格的安全性证明.该方案能够对用户所拥有的任意数量的属性进行撤销,解决了已有方案中属性撤销粒度过粗的问题.

  10. High Temperature Tensile Mechanical Behavior and Microstructural change of Fine-grained W-Cu Alloys%细晶W-Cu合金的高温拉伸力学行为与组织演变

    Institute of Scientific and Technical Information of China (English)

    刘辉明; 范景莲; 刘涛; 田家敏

    2011-01-01

    The average grain degrees less than 0.5 μm of fine-grained W-40Cu and W-50Cu alloys are studied by tensile testing in the temperature range of 200~800 ℃. The research on its fracture mechanism and micro-structural change rules at high temperature is conducted by SEM micrograph observation. The results show that the ultimate tensile strength (UTS) of the alloys decreases sharply with the increase of temperature. The elongation of W-40Cu and W-50Cu alloys decrease slightly below 400 ℃. However, the elongation of W-40Cu and W-50Cu alloys increase sharply with the increase of temperature when the temperature is above 400 ℃. Fracture characteristics show Fine-grain W-Cu alloy fracture mainly includes W particles' inter-granular rupture and Cu phase's ductility tears in room temperature. W-Cu alloy's elongation shows change due to copper alloys "medium temperature brittle"influence at the temperature of 400 ℃. When the temperature rises to 800 ℃, W-Cu alloys shows ductile fracture characteristics mainly by the fracture mode Cu phase influence.%研究了平均晶粒度在0.5μm以下细晶W-40Cu和W-50Cu合金在200~800℃范围内的高温拉伸力学行为,并结合SEM断口形貌分析了材料在高温状态下的断裂形式及其组织变化规律.结果表明:W-Cu合金拉伸强度随温度升高而迅速降低,其延伸率在室温至400℃温度区间时变化不大;当温度大于400℃时,合金延伸率迅速上升.拉伸断口特征表明:在室温条件下,细晶W-Cu合金的断裂主要包括W晶粒的沿晶断裂与Cu相的延性撕裂:温度在400℃时,Cu相开始软化,但合金材料受铜的"中温脆性"影响而使得材料的断裂延伸率变化不大;当温度达到800℃时,材料的断裂方式主要受Cu相的影响而表现出很好的延性断裂.

  11. Preparation and Characterization of Non-porous Superparamagnetic Microspheres with Epoxy Groups by Dispersion Polymerization

    Institute of Scientific and Technical Information of China (English)

    马志亚; 官月平; 刘先桥; 刘会洲

    2005-01-01

    Non-porous superparamagnetic polymer microspheres with epoxy groups were prepared by dispersion polymerization of glycidyl methacrylate (GMA) in the presence of magnetic iron oxide (Fe3O4) nanoparticles coated with oleic acid. The polymerization was carried out in the ethanol/water medium using polyvinylpyrrolidone (PVP) and 2,2’-azobisisobutyronitrile (AIBN) as stabilizer and initiator, respectively. The magnetic microspheres obtained were characterized with scanning electron microscopy (SEM), vibrating sample magnetometry (VSM) and Fourier transform infrared spectroscopy (FTIR). The results showed that the magnetic microspheres had an average size of-1μm with superparamagnetic characteristics. The saturation magnetization was found to be 4.5emu.g-1. There was abundance of epoxy groups with density of 0.028 mmol·g-1 in microspheres. The magnetic PGMA microspheres have extensive potential uses in magnetic bioseparation and biotechnology.

  12. Transfer efficiency of bacteria and viruses from porous and nonporous fomites to fingers under different relative humidity conditions.

    Science.gov (United States)

    Lopez, Gerardo U; Gerba, Charles P; Tamimi, Akrum H; Kitajima, Masaaki; Maxwell, Sheri L; Rose, Joan B

    2013-09-01

    Fomites can serve as routes of transmission for both enteric and respiratory pathogens. The present study examined the effect of low and high relative humidity on fomite-to-finger transfer efficiency of five model organisms from several common inanimate surfaces (fomites). Nine fomites representing porous and nonporous surfaces of different compositions were studied. Escherichia coli, Staphylococcus aureus, Bacillus thuringiensis, MS2 coliphage, and poliovirus 1 were placed on fomites in 10-μl drops and allowed to dry for 30 min under low (15% to 32%) or high (40% to 65%) relative humidity. Fomite-to-finger transfers were performed using 1.0 kg/cm(2) of pressure for 10 s. Transfer efficiencies were greater under high relative humidity for both porous and nonporous surfaces. Most organisms on average had greater transfer efficiencies under high relative humidity than under low relative humidity. Nonporous surfaces had a greater transfer efficiency (up to 57%) than porous surfaces (<6.8%) under low relative humidity, as well as under high relative humidity (nonporous, up to 79.5%; porous, <13.4%). Transfer efficiency also varied with fomite material and organism type. The data generated can be used in quantitative microbial risk assessment models to assess the risk of infection from fomite-transmitted human pathogens and the relative levels of exposure to different types of fomites and microorganisms.

  13. Spot morphology of non-contact printed protein molecules on non-porous substrates with a range of hydrophobicities

    NARCIS (Netherlands)

    Mujawar, L.H.; Norde, W.; Amerongen, van A.

    2013-01-01

    Non-contact inkjet printing technology is one of the most promising tools for producing microarrays. The quality of the microarray depends on the type of the substrate used for printing biomolecules. Various porous and non-porous substrates have been used in the past, but due to low production cost

  14. Spot morphology of non-contact printed protein molecules on non-porous substrates with a range of hydrophobicities

    NARCIS (Netherlands)

    Mujawar, L.H.; Norde, W.; Amerongen, van A.

    2013-01-01

    Non-contact inkjet printing technology is one of the most promising tools for producing microarrays. The quality of the microarray depends on the type of the substrate used for printing biomolecules. Various porous and non-porous substrates have been used in the past, but due to low production cost

  15. Composite sampling of a Bacillus anthracis surrogate with cellulose sponge surface samplers from a nonporous surface.

    Directory of Open Access Journals (Sweden)

    Jenia A M Tufts

    Full Text Available A series of experiments was conducted to explore the utility of composite-based collection of surface samples for the detection of a Bacillus anthracis surrogate using cellulose sponge samplers on a nonporous stainless steel surface. Two composite-based collection approaches were evaluated over a surface area of 3716 cm2 (four separate 929 cm2 areas, larger than the 645 cm2 prescribed by the standard Centers for Disease Control (CDC and Prevention cellulose sponge sampling protocol for use on nonporous surfaces. The CDC method was also compared to a modified protocol where only one surface of the sponge sampler was used for each of the four areas composited. Differences in collection efficiency compared to positive controls and the potential for contaminant transfer for each protocol were assessed. The impact of the loss of wetting buffer from the sponge sampler onto additional surface areas sampled was evaluated. Statistical tests of the results using ANOVA indicate that the collection of composite samples using the modified sampling protocol is comparable to the collection of composite samples using the standard CDC protocol (p  =  0.261. Most of the surface-bound spores are collected on the first sampling pass, suggesting that multiple passes with the sponge sampler over the same surface may be unnecessary. The effect of moisture loss from the sponge sampler on collection efficiency was not significant (p  =  0.720 for both methods. Contaminant transfer occurs with both sampling protocols, but the magnitude of transfer is significantly greater when using the standard protocol than when the modified protocol is used (p<0.001. The results of this study suggest that composite surface sampling, by either method presented here, could successfully be used to increase the surface area sampled per sponge sampler, resulting in reduced sampling times in the field and decreased laboratory processing cost and turn-around times.

  16. Mineral processing test for a fine grain disseminated gold ore from Gansu Province%甘肃某细粒浸染型金矿石选矿试验研究

    Institute of Scientific and Technical Information of China (English)

    靳建平; 向虹; 吴天骄; 万宏民; 齐晓东

    2016-01-01

    甘肃某细粒浸染型金矿石中金主要以包裹金形态存在,且载金矿物黄铁矿与脉石矿物连生关系复杂.针对该矿石的性质,进行了选矿试验研究.其结果表明:在最佳试验条件下,采用阶段磨矿-阶段浮选工艺,可获得金品位30.17 g/t、金回收率81.23%的较好指标;硫精矿经氧化焙烧—氰化浸出,金对原矿的回收率为6.96%,金总回收率达88.19%.%Mineral processing test was carried out for a fine grain disseminated gold ore from Gansu Province.The gold-carrying mineral is pyrite and it is connected with gangue minerals in a complex way.The test results under opti-mal test conditions,a stage grinding-stage flotation process can obtain a gold grade of 30.17 g/t and a gold recovery rate of 81.23 %.Sulfur concentrates go through roasting-cyanide leaching process,the recovery of primary gold ores is 6.96 %and the total recovery rate of gold is 88.19 %.

  17. Field assisted sintering of fine-grained Li7-3xLa3Zr2AlxO12 solid electrolyte and the influence of the microstructure on the electrochemical performance

    Science.gov (United States)

    Botros, Miriam; Djenadic, Ruzica; Clemens, Oliver; Möller, Matthias; Hahn, Horst

    2016-03-01

    The synthesis and processing of fine-grained Li7-3xLa3Zr2AlxO12 (x = 0.15, 0.17, 0.20) solid electrolyte (LLZO) is performed for the first time using a combination of nebulized spray pyrolysis (NSP) and field assisted sintering technique (FAST). Using FAST, the grain growth is suppressed and highly dense ceramics with 93% of the theoretical density are obtained. A tetragonal lattice distortion is observed after the sintering process. Although this structural modification has been reported to have lower Li-ion mobility compared to the cubic modification, the total conductivity of the sample at room temperature is found to be 0.33 mS cm-1, i.e. comparable to phase-pure cubic LLZO. The activation energy of 0.38 eV is also comparable to the literature values. Galvanostatic cycling of a symmetrical cell Li|LLZO|Li shows a good cycling stability over 100 h. The interfacial resistance in contact with Li-metal is determined using alternating current impedance spectroscopy to be 76 Ω cm2 and 69 Ω cm2 before and after cycling at different current densities, respectively.

  18. Introducing Advanced Fine-grained Security in dCache-SRM for PetaByte-scale Storage Systems on Global Data Grids: gPLAZMA `grid-aware PLuggable AuthoriZation MAnagement System'

    CERN Document Server

    Rana, A S; Kennedy, R; Bakken, J; Hesselroth, T; Fisk, I; Fuhrmann, P; Ernst, M; Lorch, M; Skow, D

    2006-01-01

    We introduce gPLAZMA (grid-aware PLuggable Authorization MAnagement) for dCache/SRM in this publication. Our work is motivated by a need for fine-grained security (Role Based Access Control or RBAC) in storage systems on global data grids, and utilizes VOMS extended X.509 certificate specification for defining extra attributes (FQANs), based on RFC3281. Our implementation, gPLAZMA in dCache, introduces storage authorization callouts for SRM and GridFTP. It allows using different authorization mechanisms simultaneously, fine-tuned with switches and priorities of mechanisms. Of the four mechanisms currently supported, one is an integration with RBAC services in the open science grid (OSG) USCMS/USATLAS Privilege Project, others are built-in as a lightweight suite of services (gPLAZMA lite authorization services suite) including the legacy dcache.kpwd file, as well as the popular grid-mapfile, augmented with a gPLAZMALite specific RBAC mechanism. Based on our current work, we also outline a list of future tasks....

  19. 粉末冶金法制备超细晶AZ31镁合金及超塑性变形研究%Powder Metallurgy Prepared Ultra-fine Grain AZ31 Alloy and Its Superplastic Deformation

    Institute of Scientific and Technical Information of China (English)

    林莺莺; 胡杰仁

    2013-01-01

    采用粉末冶金法制备超细晶AZ31镁合金材料,并对其微观组织形貌及相成分进行研究;利用单向拉伸试验研究了该材料在不同条件下超塑性变形.结果表明,采用球磨、冷压制坯和热挤压法可获得晶粒尺寸在1微米以下的超细晶组织,该材料在250℃,1×10-3s-1的应变速率条件下获得了最大伸长率,基本达到超塑性状态.%Ultra-fine grain AZ31 alloy bars were fabricated by power metallurgy process,and the microstructure and phase composition were also researched.The superplastic deformation was studied by simple tension test.According to the results,AZ31 alloy with the grain size under 1 μm was prepared by the process of high energy ball milling,cold compacting and hot extrusion.The superplastic deformation was achieved under the temperature of 250 ℃ and strain rate of 1 × 10-3 s-1.

  20. Martensitic Transformation and Magnetic-Field-Induced Strain in Magnetic Shape Memory Alloy NiMnGa Melt-Spun Ribbon

    Institute of Scientific and Technical Information of China (English)

    Shihai GUO; Yanghuan ZHANG; Jianliang LI; Baiyun QUAN; Yan QI; Xinlin WANG

    2005-01-01

    A magnetic shape memory alloy with nonstoichiometric Ni5oMn27Ga23 was prepared by using melt-spinning technology. The martensitic transformation and the magnetic-field-induced strain (MFIS) of the polycrystalline melt-spun ribbon were investigated. The experimental results showed that the melt-spun ribbons underwent thermal-elastic martensitic transformation and reverse transformation in cooling and heating process and exhibited typical thermoelastic shape memory effect. However the start temperature for martensitic transformation decreased from 286 K for as-cast alloy to 254 K for as-quenched ribbon and Curie temperature remains approximately constant. A particular internal stress induced by melt-spinning resulted in the formation of a texture structure in the ribbons, which made the ribbons obtain larger martensitic transformation strain and MFIS. The internal stress was released substantially after annealing, which resulted in a decrease of MFIS of the ribbons.

  1. "Fine grain Nb tube for SRF cavities"

    Energy Technology Data Exchange (ETDEWEB)

    Robert E. Barber

    2012-07-08

    Superconducting radio frequency (SRF) cavities used in charged particle linear accelerators, are currently fabricated by deep drawing niobium sheets and welding the drawn dishes together. The Nb sheet has a non-uniform microstructure, which leads to unpredictable cavity shape and surface roughness, and inconsistent "spring-back" during forming. In addition, weld zones cause hot spots during cavity operation. These factors limit linear accelerator performance and increase cavity manufacturing cost. Equal channel angular extrusion (ECAE) can be used to refine and homogenize the microstructure of Nb tube for subsequent hydroforming into SRF cavities. Careful selection of deformation and heat treatment conditions during the processing steps can give a uniform and consistent microstructure in the tube, leading to improved deformability and lower manufacturing costs. Favorable microstructures were achieved in short test samples of RRR Nb tube, which may be particularly suitable for hydroforming into SRF cavity strings. The approach demonstrated could be applicable to microstructure engineering of other tube materials including tantalum, titanium, and zirconium.

  2. Spinodal decomposition in fine grained materials

    Indian Academy of Sciences (India)

    H Ramanarayan; T A Abinandanan

    2003-01-01

    We have used a phase field model to study spinodal decomposition in polycrystalline materials in which the grain size is of the same order of magnitude as the characteristic decomposition wavelength ($\\lambda_{SD}$). In the spirit of phase field models, each grain () in our model has an order parameter ($\\eta_i$) associated with it; $\\eta_i$ has a value of unity inside the th grain, decreases smoothly through the grain boundary region to zero outside the grain. For a symmetric alloy of composition, = 0.5, our results show that microstructural evolution depends largely on the difference in the grain boundary energies, $\\gamma_{gb}$, of A-rich () and B-rich () phases. If $\\gamma^{\\alpha}_{gb}$ is lower, we find that the decomposition process is initiated with an layer being formed at the grain boundary. If the grain size is sufficiently small (about the same as $\\lambda_{SD}$), the interior of the grain is filled with the phase. If the grain size is large (say, about 10 $\\lambda_{SD}$ or greater), the early stage microstructure exhibits an A-rich grain boundary layer followed by a B-rich layer; the grain interior exhibits a spinodally decomposed microstructure, evolving slowly. Further, grain growth is suppressed completely during the decomposition process.

  3. Fine-grained control of user attributes

    DEFF Research Database (Denmark)

    Olesen, Henning; Khajuria, Samant

    2014-01-01

    Private users, enterprises and other stakeholders have a strong need to protect their resources when interacting with each other. For the users it is a matter of protecting vital personal information and assets (privacy protection), and for enterprises the main concern is to protect their intelle......Private users, enterprises and other stakeholders have a strong need to protect their resources when interacting with each other. For the users it is a matter of protecting vital personal information and assets (privacy protection), and for enterprises the main concern is to protect...... is inspired by the current trend of Bring Your Own Device (BYOD), but is extended to deal with mutual benefits for users/employees and enterprises....

  4. Spinodal decomposition in fine grained materials

    OpenAIRE

    Ramanarayan, H.; Abinandanan, TA

    2003-01-01

    We have used a phase field model to study spinodal decomposition in polycrystalline materials in which the grain size is of the same order of magnitude as the characteristic decomposition wavelength (lambda(SD))In the spirit of phase field models, each grain (i) in our model has an order parameter (eta(i)) associated with it; eta(i) has a value of unity inside the ith grain, decreasessmoothly through the grain boundary region to zero outside the grain. For a symmetric alloy of composition, c ...

  5. Plasticity in Ultra Fine Grained Materials

    Energy Technology Data Exchange (ETDEWEB)

    Koslowski, Marisol [Purdue Univ., West Lafayette, IN (United States)

    2015-04-15

    Understanding the mechanisms of deformation of nanocrystalline (nc) materials is critical to the design of micro and nano devices and to develop materials with superior fracture strength and wear resistance for applications in new energy technologies. In this project we focused on understanding the following plastic deformation processes described in detail in the following sections: 1. Plastic strain recovery (Section 1). 2. Effect of microstructural variability on the yield stress of nc metals (Section 2). 3. The role of partial and extended full dislocations in plastic deformation of nc metals (Section 3).

  6. Fine grain tungsten produced with nanoscale powder

    Institute of Scientific and Technical Information of China (English)

    Tao Lin; Fang Zhao; Liying Zhang; Chengyi Wu; Zhimeng Guo

    2005-01-01

    Nanoscale tungsten powder was prepared by reducing nanoscale tungsten trioxide in hydrogen to WO2.90 and further to W powder. After compacted with a rubber die, the nanoscale tungsten powder was sintered in a high-temperature dilatometer to investigate its shrinkage process. The results show that the compact of the nanoscale tungsten powder starts to shrink at 1050℃ and ends at 1500℃. The shrinkage rate reaches the maximum value at 1210℃. The relative density of sintered samples is 96.4%, and its grain size is about 5.8 μm.

  7. A Fine-Grained Coalition Access Control Policy for Jointly-Owned Resources in Collaborative Environments%协同环境中共有资源的细粒度协作访问控制策略

    Institute of Scientific and Technical Information of China (English)

    雷浩; 黄建; 冯登国

    2005-01-01

    在军事和商业领域中,由多个自治域形成的协作群体对共有资源(如客体、应用程序以及服务等)的访问问题越来越受到重视.协作中的基本事实是:尽管这些自治域有共同的目标,但同时有不同的自身利益.为了有效地保护共有资源,把"信任"的概念引入了协作访问控制中,并在基于量化权限的思想上,提出了细粒度的协作访问控制策略.在该策略里,权限的使用形式是元权限,也就是单位权限,它是访问共有客体权限的一个划分,可为多个域中不同用户所拥有.当访问共有资源时,参与者们所拥有的元权限的值之和以及人数必须达到规定的权限门限值和人数值,并且访问时间是所有参与者的共同许可访问时间段,这使得可以对协作资源进行有效地分布控制.另外,还引入了元权限的使用时间段约束.最后,证明了该细粒度协作访问控制策略关于协作系统的状态转换是保持安全的.%Joint access to shared resources (e.g., objects, applications, and services) among autonomous domains that form a coalition has recently become important in both military and commercial areas. The brass tacks in coalition are that these domains have different self-interests although they focus on achieving a common goal. In this paper, to enable effective protection of jointly-owned resources, the notion of trust into coalition access control is built, and a fine-grained access control policy based on quantifying permission idea is proposed. The usage format of permission in this policy is meta-permission that is a share of access permission to coalition resources and is owned by multiple domain users. When accessing jointly owned resources, the sum of participants'meta-permission value must attain a predefined permission quantity called "permission-threshold" and an assigned participant member number. In addition, permissible time span of the meta-permission is also taken into

  8. Research on welding joint microstructure and properties of fine-grained high strength steel for electric transmission tower%电铁塔用细晶高强钢焊接接头组织与性能研究

    Institute of Scientific and Technical Information of China (English)

    杜宝帅; 张忠文; 李新梅; 邹勇

    2011-01-01

    Ultra-fine grained Q420 steel manufactured by TMCP was welded by means of shielded metal arc welding and CO2 gas metal arc welding.Microstructure and mechanical properties of the welded joint were investigated, and impact toughness of hot rolled Q420 steel joint was also analyzed.Results show that using E5515 electrode and ER55-G welding wire,weld metal consists of ferrite and pearlite with little amount.The presence of acicular ferrite in the weld metal fabricated by ER55-G welding wire is attributed to the addition of Ti in it.Tensile test showed that the specimen fractured at the base metal, indicating the strength of the weld metal is higher than that of the base metal. Microhardness of the weld metal is higher than that of the base metal and soft phenomenon was not observed for the HAZ of the welded joint.In comparison to Q420 steel fabricated by hot rolling, welded joint of fine-grained steel shows high toughness and thus it is more suitable for being used for electric transmission tower that requires high impact toughness at low temperature.%采用焊条电孤焊、CO2气体保护焊焊接了控扎控冷制备输电铁塔用细晶Q420低合金高强钢.研究焊接接头显微组织和力学性能,并对比分析热轧制备Q420钢焊接接头的冲击韧性.研究结果表明,选择E5515焊条、ER55-G焊丝焊接所得细晶Q420高强钢焊接接头焊缝金属主要由铁素体和少量珠光体构成,ER55-G焊丝由于添加Ti元素获得了较多针状铁索体.拉伸试验结果表明,焊接接头断裂于母材位置,焊缝具有比母材更高的强度.焊缝金属的显微硬度高于母材,接头热影响区未出现软化现象.相比较热轧制备Q420高强钢,控扎控冷制备细晶Q420钢焊接接头冲击韧性更高,更加适宜于具有较高低温韧性要求的输电铁塔制造.

  9. Fine-grained Multi-channel Access Mechanism for Dense Wi-Fi Networks%高密度Wi-Fi网络中细粒度的多信道接入机制

    Institute of Scientific and Technical Information of China (English)

    王海军; 李佳迅; 赵海涛; 王杉

    2015-01-01

    It proposes a flexible framework for fine-grained channel width adaptation and multi-channel access in Wi-Fi networks. The framework adopts DOFDM in physical layer. It al ocates the frequency resource in the granularity of sub-carrier, which facili-tates the channel width adaptation for multi-channel access and thus brings more flexibility and higher frequency utilization ef-ficiency. In MAC layer, it uses a time-frequency domain backoff scheme, which combines the popular time-domain BEB schemes and the frequency-domain backoff to decrease the access col ision, resulting in higher access probability for the con-tending nodes.%针对Wi-Fi网络中细粒度信道带宽自适应和多信道接入提出了一种灵活的框架。该框架在物理层采用非连续正交频分复用(DOFDM),它以子载波作为粒度来分配频率资源,促进了多信道接入中信道带宽的自适应,从而带来更大的灵活性和更高的频率利用率。在MAC层,该框架采用一种结合了常用的时域二进制指数退避机制和频域退避的时频域联合退避方案来减少接入的碰撞,增大了竞争节点的接入概率。

  10. Research and design of fine-grained traffic operation strategies in business and operation support system%精细化流量经营业务支撑系统的研究与设计

    Institute of Scientific and Technical Information of China (English)

    郭健

    2013-01-01

      随着智能终端技术的发展,移动运营商传统话音业务增长逐渐趋于稳定,数据流量业务增长明显,但是与之对应的业务收入并没有呈现出相关的增长态势。面对流量经营带来的新业务模式、新用户体验和新网络架构,如何满足快速增长的移动互联网业务需求成为移动运营商建设业务支撑系统面临的关键挑战。本文主要研究面向流量经营的流量计费策略和经分应用模型的制定,结合终端、业务、网络等维度分析数据业务用户的属性及行为特征,为精细化流量经营活动提供业务支撑手段。%With the rapid development of smart terminals, the need of traditional voice services is saturated. However, data services are growing fast nowadays. But the income doesn’t increase in proportion with the growth of data services. New service model, network architecture and user experience is coming up. The network operators face the challenges and pressure of traffic flow which is brought by growth of data services. Fine-grained traffic operation strategies are in great need for the network operators. In this paper, new service and application models are discussed. And the factors of terminal type, service classification, access networks and user characteristics are taken into account to build the application models.

  11. A Survey of Subjectivity Classification and Aspect Extraction in Fine-Grained Opinion Mining%细颗粒度观点挖掘中的观点句识别与要素抽取研究综述

    Institute of Scientific and Technical Information of China (English)

    陈锋

    2015-01-01

    细颗粒度观点挖掘需要解决观点句识别、要素抽取等关键问题。论文对国内外相关研究进行梳理,归纳现有观点句识别方法并找出影响识别率的原因,分析基于规则和基于统计的两类方法进行要素抽取的优势和不足。研究发现,机器学习方法或人工和机器相结合的方法是要素识别研究的基本趋势,观点本体和观点表达语言规律的研究需要进一步加强,应用领域有待扩展,观点抽取结果挖掘需进一步深入。%The key steps in fine-grained opinion mining are subjectivity classification and aspect extraction . By reviewing of domestic and foreign related research, the formulated definition of the opinion and aspect is made and the reasons of the low recognition rate are summarized. and then the advantages and disadvantages of two kinds of methods( based on rules and statistics ) are analyzed. It is found that the semi-supervised machine learning method is a research trend. This paper proposes to strengthen the research on linguistic rules and the ontology of opinion, to expand the application fields and make the comprehensive utilization of the results.

  12. Small particle reagent based on crystal violet dye for developing latent fingerprints on non-porous wet surfaces

    Directory of Open Access Journals (Sweden)

    Richa Rohatgi

    2015-12-01

    Full Text Available Small particle reagent (SPR is a widely used method for developing latent fingerprints on non-porous wet surfaces. SPR based on zinc carbonate hydroxide monohydrate, ZnCo3·2Zn(OH2·H2O – also called basic zinc carbonate – has been formulated. The other ingredients of the formulation are crystal violet dye and a commercial liquid detergent. The composition develops clear, sharp and detailed fingerprints on non-porous items, after these were immersed separately in clean and dirty water for variable periods of time. The ability of the present formulation to detect weak and faint chance prints not only enhances its utility, but also its potentiality in forensic case work investigations. The raw materials used to prepare the SPR are cost-effective and non-hazardous.

  13. Diffusion and Clustering of Carbon Dioxide on non-porous Amorphous Solid Water

    CERN Document Server

    He, Jiao; Vidali, Gianfranco

    2016-01-01

    Observations by ISO and Spitzer towards young stellar objects (YSOs) showed that CO$_2$ segregates in the icy mantles covering dust grains. Thermal processing of ice mixture was proposed as responsible for the segregation. Although several laboratory studied thermally induced segregation, a satisfying quantification is still missing. We propose that the diffusion of CO$_2$ along pores inside water ice is the key to quantify segregation. We combined Temperature Programmed Desorption (TPD) and Reflection Absorption InfraRed Spectroscopy (RAIRS) to study how CO$_2$ molecules interact on a non-porous amorphous solid water (np-ASW) surface. We found that CO$_2$ diffuses significantly on a np-ASW surface above 65~K and clusters are formed at well below one monolayer. A simple rate equation simulation finds that the diffusion energy barrier of CO$_2$ on np-ASW is 2150$\\pm$50 K, assuming a diffusion pre-exponential factor of 10$^{12}$ s$^{-1}$. This energy should also apply to the diffusion of CO$_2$ on wall of pores...

  14. REVIEW ON POROUS AND NON-POROUS FLAT PLATE AIR COLLECTOR WITH MIRROR ENCLOSURE

    Directory of Open Access Journals (Sweden)

    M. PRADHAPRAJ,

    2010-09-01

    Full Text Available In solar air heater, flat plat collectors are the best heat transferring devices. But the effectiveness of these collectorsis very low because of lack of technology. Solar assisted heated air is successfully used for drying applications and space heating under controlled conditions. From the solar flat plate air heater the hot air is transferred to a conventional dryer or to the combined heater and drying chamber directly. Hence, solar assisted air heaters arecheaper and reliable. The important factors affecting these systems are the solar radiation, mechanical loading, temperature and leakage. The air heater efficiency depends on the design of the system as well as the construction materials and the assembly. The solar air heating systems has acceptable life span of 15 to 20 years. The addition ofside mirror enclosures is to increase the amount of solar radiation absorption at the collector plate so that the collector increases the yield and operate in a higher temperature range. Therefore with the addition of side mirrors one can able to maximize the output of fixed flat plate collectors. A flat plate air collector will be more efficient if it is made up of porous medium when comparing it with the non porous collectors according to the study. In this paper, the performances of porous and non-porous absorber plates are discussed. Also the possible methods of finding out air leakages and the methodology adopted for the performance and efficiency calculations are also discussed.

  15. The biocompatibility of porous vs non-porous bone cements: a new methodological approach

    Directory of Open Access Journals (Sweden)

    C. Dall'Oca

    2014-06-01

    Full Text Available Composite cements have been shown to be biocompatible, bioactive, with good mechanical properties and capability to bind to the bone. Despite these interesting characteristic, in vivo studies on animal models are still incomplete and ultrastructural data are lacking. The acquisition of new ultrastructural data is hampered by uncertainties in the methods of preparation of histological samples due to the use of resins that melt methacrylate present in bone cement composition. A new porous acrylic cement composed of polymethylmetacrylate (PMMA and β-tricalciumphosphate (β-TCP was developed and tested on an animal model. The cement was implanted in femurs of 8 New Zealand White rabbits, which were observed for 8 weeks before their sacrifice. Histological samples were prepared with an infiltration process of LR white resin and then the specimens were studied by X-rays, histology and scanning electron microscopy (SEM. As a control, an acrylic standard cement, commonly used in clinical procedures, was chosen. Radiographic ultrastructural and histological exams have allowed finding an excellent biocompatibility of the new porous cement. The high degree of osteointegration was demonstrated by growth of neo-created bone tissue inside the cement sample. Local or systemic toxicity signs were not detected. The present work shows that the proposed procedure for the evaluation of biocompatibility, based on the use of LR white resin allows to make a thorough and objective assessment of the biocompatibility of porous and non-porous bone cements.

  16. Investigation of Critical Heat Flux Enhancement for Porous and Non-porous Structures without Surface Wettability Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Han; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-05-15

    Nanoparticles and nano-sheets have been used in base fluids to enhance the BHT and CHF. Nanoparticles such as Al{sub 2}O{sub 3}, TiO{sub 2}, ZnO, Ag, Au and SiC have been studied for investigating the enhancement in the BHT and CHF. Most of the studies illustrated the enhancement in the heat transfer and CHF based on nanoparticle deposition during boiling occurrences. Research on nanotechnology in boiling experiments such as the deposition of particles on heating surfaces, nanowires, and thin film coatings laid on a substrate was investigated as point of effective heat transfer methods. A theoretical model to predict the CHF based on the dynamic receding contact angle, which includes surface-liquid interaction effects, was accommodated the change of surface wettability due to the deposition of nanoparticles. Park et al., however, reported the reverse results that the enhancement in the CHF could not be explained by the relation of the improved surface wettability. They focused on the change of hydrodynamic instability wavelength due to the deposition of nanoparticles and concluded that the change of instability wavelength could be considered as the CHF enhancement mechanism. Therefore, an experimental CHF study without the change of surface wettability should be conducted to define the parameters attributing to the CHF. This paper presents a study on the enhancement BHT and CHF with porous and non-porous surfaces deposited on a bare indium tin oxide (ITO) surface using FC-72 refrigerant. Plasma enhanced chemical vapor deposition (PECVD) system was applied to deposit the SiC surface as non-porous structure and porous SiC-coated surface was manufactured by deposition of nanoparticles. For graphene surface, rapid thermal annealing (RTA) method and nanoparticles of graphene oxide were used for non-porous and porous structure, respectively. In the present work the study of the BHT and CHF is conducted using non-porous and porous heater surfaces without the effect of

  17. 反复镦压工艺制备超细晶铜的组织与性能%Microstructure and property of ultra-fine grained copper produced by cyclic channel die compression process

    Institute of Scientific and Technical Information of China (English)

    石凤健; 王雷刚; 许涛; 芦笙

    2011-01-01

    The principle,processing routes and characteristics of cyclic channel die compression(CCDC) process were introduced.Microstructure,microhardness and tensile property of pure copper subjected to CCDC process were investigated.The results show that large strain can be accumulated through CCDC process without changing the size and shape of the specimen.The grains of as-annealed copper are refined obviously after multi-pass CCDC.The average Vickers microhardness increases rapidly before 3 passes CCDC and then becomes stable with further increasing passes of CCDC.Ultimate tensile strength of the pure copper by CCDC is improved from initial 198.5 MPa to the maximum value of 488.8 MPa.However,its elongation to failure decreases after CCDC,but the elongation is still over 15%.Fracture mechanism of pure copper after CCDC belongs to ductile fracture.The investigation shows that CCDC is a promising method for producing bulk ultra-fine grained materials.%介绍了反复镦压工艺的原理、路线及特点,并研究了纯铜反复镦压后的组织、硬度及拉伸性能。结果表明,反复镦压可在不改变试样形状和尺寸的情况下累积很大的应变。退火态纯铜经多道次镦压后晶粒明显细化。3道次镦压前,纯铜的平均显微硬度随应变的增加快速增加,随镦压次数的进一步增加,硬度上升的幅度下降。多道次镦压后纯铜的抗拉强度明显提高,从退火态的198.5 MPa提高到最高约488.8 MPa。镦压后纯铜的断后伸长率明显下降,但仍在15%以上,其断裂性质仍属韧性断裂。研究结果说明反复镦压是一种有应用前景的制备块体细晶材料的方法。

  18. 基于层叠模型细粒度情感要素抽取及倾向分析%Fine-Grained Emotional Elements Extraction and Affection Analysis Based on Cascaded Model

    Institute of Scientific and Technical Information of China (English)

    孙晓; 唐陈意

    2015-01-01

    For the fine-grained emotional elements extraction problem in product reviews, a cascaded model combining conditional random fields ( CRFs) and support vector machine ( SVM) is put forward. Aiming at the recognition of sentiment objects and emotional words, the review of syntactic and semantic informations are introduced into CRFs model to further improve the robustness of feature templates in CRFs. In SVM model, the features of deep semantic information of sentiment objects and emotional words and basic emotional orientation of emotional words are introduced to improve the traditional bag-of-words model. The sentiment of word pair is classified to acquire key information from product reviews, namely triples of ( sentiment object, sentiment word, sentiment trend) . Experimental results show that the proposed CRFs and SVM cascaded model efficiently improves the precision of emotional elements extraction and emotion classification.%针对商品评论中的细粒度情感要素抽取问题,提出基于条件随机场模型( CRFs)和支持向量机( SVM)的层叠模型。针对情感对象与情感词的识别,将评论的句法信息、语义信息等引入CRFs模型,进一步提高CRFs特征模板的鲁棒性。在SVM模型中,引入情感对象和情感词的深层词义及情感词的基本情感倾向等特征,改进传统的词包模型,对掖情感对象,情感词业词对进行细粒度的情感分类判断,从而获得商品评论中的情感关键信息:(情感对象,情感词,情感倾向性)三元组。实验表明,文中的CRFs和SVM层叠模型可提高情感要素抽取与情感分类判断的准确性。

  19. 面向骨干网NIDS的细粒度并行多模式匹配方法%Fine-grained Parallel Multi-pattern Matching for Backbone Network NIDS

    Institute of Scientific and Technical Information of China (English)

    邵宗有; 刘兴奎; 刘新春; 孙凝晖

    2013-01-01

    As the network bandwidth continuously increases, the network security has been seriously threatened by malicious behaviors and risks. Network intrusion detection system (NIDS) is one of the efficient measures to cope with intrusion threats and protect information security, which employs pattern matching techniques to analyze incoming packets and detect potential threats. However,pattern matching is such a compute-intensive task that most current techniques can't meet the demand of NIDS for backbone networks over lOGbps speed. We proposed a novel Bloom filter based approach for pattern matching,called PBPM (Parallel-Bloom-filter-based multi-Pattern Matching). PBPM employs multiple copies of the same Bloom filter to carry out parallel matching on different positions of the input text at the same time. The fine-grained parallel approach is able to skip multiple characters per clock when implemented on FPGAs,dramatically improving pattern matching performance. Experimental results on the rule set from Snort 2. 9 show that the throughput of PBPM exceeds more than 20Gbps.%随着网络带宽的快速增长,互联网正面临着日益严重的安全威胁.网络入侵检测系统(NIDS)利用模式匹配等技术对网络报文进行分析和检测,是防范网络威胁、保护网络安全的一种有效手段.但模式匹配消耗巨大的计算量,现有的技术难以满足10Gbps以上骨干网络NIDS的需求.提出了基于Bloom filter的细粒度并行模式匹配技术PBPM(Parallel-Bloom-filter-based multi-Pattern Matching),PBPM利用多个相同的Bloom filter分别从输入文本的不同位置处并行匹配,每个周期可完成多个字符的匹配,显著提高了匹配速率.详细讨论了在FPGA上的实现方式,在Snort 2.9规则集上的测试结果表明,PBPM能够提供超过20Gbps的模式匹配需求.

  20. Determining the turnover time of mercury-contaminated fine-grained sediment in the gravel bed of the South River, Virginia using Pb-210, Be-7 and Cs-137

    Science.gov (United States)

    Pomraning, S. N.; Pizzuto, J. E.; Jurk, D.

    2010-12-01

    Fine-grained sediment and associated contaminants mediate important geochemical cycles in the hyporheic zone of gravel-bed rivers, but the turnover time of fine particles in these environments has rarely been measured. We analyzed the activities of Pb-210, Cs-137 and Be-7 in samples from four cores obtained on November 2, 2009 from a representative section of the bed composed of a mixture of sand, pebbles, and cobbles. The median grain size is 25.5 mm, the 84th percentile grain diameter is 57.8 mm, and 5.7% of the bed is composed of sediment smaller than 2 mm (sand sized or smaller sediment). The cores were sampled at five centimeter depth increments and each sample was sieved to extract the silt- and clay-sized particles. After freeze-drying the samples, equivalent depth intervals from all the cores were combined to yield a spatially averaged sample with depth intervals of 0-5 cm, 5-10 cm, 10-15 cm, 15-20 cm and 20-25 cm. Radionuclide activities were measured using a Canberra low energy germanium detector (model GL2020R). Activities of Pb-210 at the time of deposition were estimated from suspended sediment samples collected during a high flow event (recurrence interval 0.24 years) that occurred on November 13, 2009. At a depth of 2.5 cm, the Pb-210 dating indicates that the silt-clay fine fraction of the hyporheic zone is 21.3 years old; fine sediment at a depth of 17.5 cm is 29.3 years old. Assuming that the time-averaged bed elevation has not changed over time, and that sediment at depth is periodically removed by scour and subsequently replaced by fill, methods of reservoir theory suggest that the turnover time of silt- and clay-sized particles in the hyporheic zone is about two years. Because deep scour events are apparently relatively rare, approximately 21 years are required to rework 90% of the bed. These results have important implications for contaminant remediation. Even if all ongoing sources of mercury to the South River are removed, several decades

  1. Hydraulic Models for the Accumulation of Mercury-Contaminated Fine-Grained Sediment in Forested and Non-Forested Near-Bank Regions of the South River, Virginia, 1930-2007

    Science.gov (United States)

    Pizzuto, J. E.; Skalak, K.

    2010-12-01

    Mercury was released into the South River from a textile manufacturing facility in Waynesboro, Virginia, beginning in 1930. Because mercury strongly adsorbs to fine particles, it is a useful tracer for fine-grained sediment transport processes. Mercury concentrations were measured on sediment samples from 29 cores taken from near-bank environments up to 14 km downstream from the textile plant. Mercury concentrations average around 20 ppm, with a maximum of 839 ppm and a minimum of mercury in each core ranged from 0.0008 to 0.2 kg/m^2. These data were used to calibrate simple hydraulic models of mercury accumulation at each coring site since 1930. Previous studies document the concentration of mercury on suspended sediment through time, allowing our models to estimate the history of mercury accumulation and to infer rates of sedimentation. Rating curves for each coring site were computed based on Total Station surveys of channel morphology and flow records interpolated between 3 U.S. Geological Survey gauging stations. Hydraulic roughness parameters were obtained from a HEC-RAS model calibrated to measured stage-discharge relationships. The calibrated mercury accumulation model explains 69% of the variability in the observed mercury inventories. At forested sites, each inundation event deposited an average of 0.00065 kg of mercury, while deposition at non-forested sites (mostly in pasture), averaged 0.00009 kg of mercury per event, lower by a factor of 7. At 6 sites where lateral migration increased accommodation space, mercury deposition was increased by an order of magnitude. If particle-associated mercury accumulation is assumed to result only from reduced basal shear stresses, critical shear stresses for deposition are unreasonably low, which suggests that a significant amount of the observed inventory of mercury-contaminated sediment accumulates on plant stems and leaves, rather than only being deposited on the ground. 58% of the total mercury inventory

  2. Diffusion and Clustering of Carbon Dioxide on Non-porous Amorphous Solid Water

    Science.gov (United States)

    He, Jiao; Emtiaz, Shahnewaj M.; Vidali, Gianfranco

    2017-03-01

    Observations by ISO and Spitzer toward young stellar objects showed that CO2 segregates in the icy mantles covering dust grains. Thermal processing of the ice mixture was proposed as being responsible for the segregation. Although several laboratories studied thermally induced segregation, a satisfying quantification is still missing. We propose that the diffusion of CO2 along pores inside water ice is the key to quantify segregation. We combined Temperature Programmed Desorption and Reflection Absorption InfraRed Spectroscopy to study how CO2 molecules interact on a non-porous amorphous solid water (np-ASW) surface. We found that CO2 diffuses significantly on an np-ASW surface above 65 K and clusters are formed at well below one monolayer. A simple rate equation simulation finds that the diffusion energy barrier of CO2 on np-ASW is 2150 ± 50 K, assuming a diffusion pre-exponential factor of 1012 s‑1. This energy should also apply to the diffusion of CO2 on the wall of pores. The binding energy of CO2 from CO2 clusters and CO2 from H2O ice has been found to be 2415 ± 20 K and 2250 ± 20 K, respectively, assuming the same prefactor for desorption. CO2–CO2 interaction is stronger than CO2–H2O interaction, in agreement with the experimental finding that CO2 does not wet the np-ASW surface. For comparison, we carried out similar experiments with CO on np-ASW, and found that the CO–CO interaction is always weaker than CO–H2O. As a result, CO wets the np-ASW surface. This study should be of help to uncover the thermal history of CO2 on the icy mantles of dust grains.

  3. Spot morphology of non-contact printed protein molecules on non-porous substrates with a range of hydrophobicities.

    Science.gov (United States)

    Mujawar, Liyakat Hamid; Norde, Willem; van Amerongen, Aart

    2013-01-21

    Non-contact inkjet printing technology is one of the most promising tools for producing microarrays. The quality of the microarray depends on the type of the substrate used for printing biomolecules. Various porous and non-porous substrates have been used in the past, but due to low production cost and easy availability, non-porous substrates like glass and plastic are preferred over porous substrates. On these non-porous substrates, obtaining spot uniformity and a high signal to noise ratio is a big challenge. In our research work, we have modified pristine glass slides using various silanes to produce a range of hydrophobic glass substrates. The hydrophobicities of the slides expressed in the contact angle (θ) of a sessile drop of water were 49°, 61°, 75°, 88° and 103°. Using a non-contact inkjet printer, microarrays of biotinylated biomolecules (BSA and IgG) were produced on these modified glass substrates, pristine (untreated) glass and also on HTA polystyrene slides. The uniformity of the spots, reflecting the distribution of the biomolecules in the spots, was analyzed and compared using confocal laser scanning microscopy (CLSM). The quality of the spots was superior on the glass slide with a contact angle of ∼75°. We also investigated the influence of the hydrophobicity of the substrate on a two-step, real diagnostic antibody assay. This nucleic acid microarray immunoassay (NAMIA) for the detection of Staphylococcus aureus showed that on highly hydrophilic (θ 100°) the assay signal was low, whereas an excellent signal was obtained on the substrates with intermediate contact angles, θ ∼ 61° and θ ∼ 75°, respectively.

  4. Accommodative Behavior of Non-porous Molecular crystal at Solid-Gas and Solid-Liquid Interface

    OpenAIRE

    Mande, Hemant M.; Ghalsasi, Prasanna S.

    2015-01-01

    Molecular crystals demonstrate drastically different behavior in solid and liquid state, mainly due to their difference in structural frameworks. Therefore, designing of unique structured molecular compound which can work at both these interfaces has been a challenge. Here, we present remarkable ‘molecular’ property by non-porous molecular solid crystal, dinuclear copper complex (C6H5CH(X)NH2)2CuCl2, to reversibly ‘adsorb’ HCl gas at solid-gas interface as well as ‘accommodate’ azide anion at...

  5. (Ba,Eu)Ti03细晶粒陶瓷制备中的影响因素%Influence factors of preparing ( Ba, Eu) TiO3 fine grain ceramics

    Institute of Scientific and Technical Information of China (English)

    董耀龙; 路大勇

    2012-01-01

    (Ba1-xEux )TiO3 and (Ba1-xEux )Ti1-x/sO3 ceramics with tetragonal structure were prepared by a cold - pressing ceramic technique under the temperatures of 1 400 3C and 1 300 C ,respectively. The influence of Eu eontent,Ti-vacaney defects and sintering temperature on preparing (Ba, Eu )TiO3 fine grain ceramics were studied using X- ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscope (AFM). The results indicate that the average grain size of (Ba~_~Eu~)Ti~ _~/803 (x = 0.05) ceramics prepared under 1 300 C were less than 1 μm, but the average grain size of (Ba1 -x Eux )TiO3 ceramics prepared under 1 400 C grows to 5 μm. Whereas,at x = 0.03 ,the (Ba1-xEu3)TiO3 ceramics still can refine to 1 μm. This means that the higher sintering temperature is not the main reason for grain growth,the existence of Ti-vaeaney plays a role in suppressing grain growth. As x〉 0.07 ,the average grain size of (Ba1-xEUx)TiO3 ceramics were still greater than 5 Ixm,illustrating that the continuous increase of Eu content can not inhibit grain growth.%采用冷压陶瓷技术,分别在1400℃和1300℃制备了具有四方结构的(Ba1-xEu)TiO3和(Ba1-xEu)Ti1-x/80,陶瓷.应用x射线衍射(XRD)、扫描电子显微镜(SEM)和原子力显微镜(AFM)研究Eu含量、n空位缺陷和陶瓷化烧结温度的变化对制备(Ba,Eu)TiO,细晶粒陶瓷的影响因素.结果表明:当z=0.05时,1300'1:制备的(Ba1-xEu)Ti,-x/80,陶瓷细化到平均晶粒尺寸小于1μm,1400℃制备的(BahEu,)Ti03陶瓷却畸变生长到5斗m.而x=0.03时,(Ba1-xEu)TiO,陶瓷仍能细化到1μm.说明较高的陶瓷化烧结温度并不是晶粒生长的主要原因,Ti空位的存在起到抑制晶粒生长的作用.x≥0.07时,(Ba1-xEu)TiO,陶瓷为大于5斗m的粗晶粒陶瓷,说明Eu含量的继续增加不能抑制晶粒生长.

  6. 有限域上高效的细粒度数据完整性检验方法%An Efficient Integrity Check Method for Fine-Grained Data over Galois Field

    Institute of Scientific and Technical Information of China (English)

    陈龙; 王国胤

    2011-01-01

    基于交叉检验思想的细粒度数据完整性检验方法在实现完整性检验的同时可以对少数错误进行准确和高效的隔离,从而避免因偶然错误或个别篡改造成整体数据失效的灾难性后果.针对需要隔离多个错误时现有方案效率不高的问题,提出了多维结构下基于有限域均匀划分的完整性交叉检验方法,相应地构造了高效的多错完整性指示编码.该方法将完整性检验Hash数据分为若干组,任一组Hash可在某一中间粒度独立指示所有数据对象的完整性,多组Hash结合起来则在更小的基本粒度指示数据的完整性.该方法实现了模块化的Hash结构,对于GF(q)上的d维向量空间,每增加(d-1)组共(d-1)q个Hash即可多指示一个错.分析了该编码在不同参数下的性能,分析结论和实验结果表明该编码效率高,具有灵活的参数选择,可满足各种应用的不同需要.%Fine-grained data integrity checking methods by crossing hashing could isolate a portion of corrupted data segments and assure the integrity of other data at the same time, so as to mitigate the disaster effect on the data by some random errors or intentional forging modification. To improve the efficient of current available method for multi-error cases, a new crossing-hash integrity checking method is proposed based on Galois field uniform partition of multi-dimension structure, herein an efficient integrity indication code for multi-errors case is constructed accordingly. The method has a modular hash check structure. All hashes are divided into several groups, where each group with q rows d-1 columns hashes can indicate the integrity of all data independently in a moderate grain and combined hashes of several groups can indicate the integrity of data in a finer grain. At the same time, in a d dimension vector space over GF(q), one more error can be indicated by adding q rows d- 1 columns hashes every time. Performances with various

  7. In vivo guided vascular regeneration with a non-porous elastin-like polypeptide hydrogel tubular scaffold.

    Science.gov (United States)

    Mahara, Atsushi; Kiick, Kristi L; Yamaoka, Tetsuji

    2017-01-28

    Herein, we demonstrate a new approach for small-caliber vascular reconstruction using a non-porous elastin-like polypeptide hydrogel tubular scaffold, based on the concept of guided vascular regeneration (GVR). The scaffolds are composed of elastin-like polypeptide, (Val-Pro-Gly-Ile-Gly)n , for compliance matching and antithrombogenicity and an Arg-Gly-Asp (RGD) motif for connective tissue regeneration. When the polypeptide was mixed with an aqueous solution of β-[Tris(hydroxymethyl)phosphino]propionic acid at 37°C, the polypeptide hydrogel was rapidly formed. The elastic modulus of the hydrogel was 4.4kPa. The hydrogel tubular scaffold was formed in a mold and reinforced with poly(lactic acid) nanofibers. When tubular scaffolds with an inner diameter of 1 mm and length of 5 mm were implanted into rat abdominal aortae, connective tissue grew along the scaffold luminal surface from the flanking native tissues, resulting in new blood vessel tissue with a thickness of 200 μm in 1 month. In contrast, rats implanted with control scaffolds without the RGD motif died. These results indicate that the non-porous hydrogel tubular scaffold containing the RGD motif effectively induced rapid tissue regeneration and that GVR is a promising strategy for the regeneration of small-diameter blood vessels. This article is protected by copyright. All rights reserved.

  8. Profiling the progression of cancer: separation of microsomal proteins in MCF10 breast epithelial cell lines using nonporous chromatophoresis.

    Science.gov (United States)

    O'Neil, Kimberly A; Miller, Fred R; Barder, Timothy J; Lubman, David M

    2003-07-01

    The heterogeneity of cellular protein expression has stimulated development of separations targeting smaller groups of related proteins rather than entire proteomes. The following work describes the development of a technique for the characterization of membrane subproteomes from five different breast epithelial cell lines. Intact membrane proteins are separated by hydrophobicity in the first dimension using nonporous reversed-phase high-performance liquid chromatography (RP-HPLC) to generate unique chromatographic profiles. Fractions of eluent are further separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to create distinct banding patterns. This hybrid liquid phase/gel phase method circumvents issues of membrane protein precipitation and provides a simple strategy aimed at isolating and characterizing a traditionally underrepresented protein class. Membrane protein profiles are created that discriminate between microsomal fractions of breast epithelial cells in different stages of neoplastic progression. Proteins are subsequently identified using matrix-assisted laser desorption/ionization - mass spectrometry (MALDI-MS) mass fingerprinting and MALDI-quadrupole time of flight - tandem mass spectrometry (QTOF-MS/MS) peptide sequencing. Furthermore, as this strategy preserves intact protein structure, further characterization can be performed on proteins producing mass fingerprint spectra and fragmentation spectra that did not result in database protein identifications. The coupling of nonporous RP-HPLC with SDS-PAGE provides a useful alternative to two-dimensional PAGE (2-D-PAGE) for membrane protein analysis.

  9. Persistence of the 2009 pandemic influenza A (H1N1 virus in water and on non-porous surface.

    Directory of Open Access Journals (Sweden)

    Amélie Dublineau

    Full Text Available Knowledge of influenza A virus survival in different environmental conditions is a key element for the implementation of hygiene and personal protection measures by health authorities. As it is dependent on virus isolates even within the same subtype, we studied the survival of the 2009 H1N1 pandemic (H1N1pdm virus in water and on non-porous surface. The H1N1pdm virus was subjected to various environmental parameters over time and tested for infectivity. In water, at low and medium salinity levels and 4°C, virus survived at least 200 days. Increasing temperature and salinity had a strong negative effect on the survival of the virus which remained infectious no more than 1 day at 35°C and 270 parts per thousand (ppt of salt. Based on modeled data, the H1N1pdm virus retained its infectivity on smooth non-porous surface for at least 7 days at 35°C and up to 66 days at 4°C. The H1N1pdm virus has thus the ability to persist in water and on glass surface for extended periods of time, even at 35°C. Additional experiments suggest that external viral structures in direct contact with the environment are mostly involved in loss of virus infectivity.

  10. 深部细粒碎屑岩储层成岩作用研究--以苏北盆地张家垛油田阜三段为例%Diagenesis of the deep-seated fine-grained clastic reservoirs:An example from the 3rd member of the Funing Formation in the Zhangjiaduo Oil Field,Subei Basin

    Institute of Scientific and Technical Information of China (English)

    韩玫梅; 丁晓琪; 张哨楠; 陈倩倩

    2015-01-01

    毗邻烃源岩的细粒储层,由于其岩石结构、组分及沉积环境的特殊性,成岩作用表现出一定差异。本文以张家垛油田阜三段细粒碎屑岩储层为例,通过铸体薄片、X射线衍射、扫描电镜等相关分析,研究其成岩作用的特殊性。研究结果表明:(1)细粒储层的成分成熟度和结构成熟度较高,常被泥岩包裹,在压实作用中若存在欠压实,粒间孔可以被很好地保留下来;(2)细粒储层形成时水动力较弱,杂基含量高导致微孔较多;(3)大量的粘土矿物使孔隙比表面增加,抑制了后期硅质和碳酸盐胶结物的析出;(4)比表面的增加减缓了孔隙流体的对流速率和扩散速率,不利于次生孔隙的形成,粒度越细,次生孔隙越不发育。细粒碎屑岩储层有别于常规储层,对其特殊的成岩作用进行研究具有重要的理论价值和实际意义。%Currently much attention is given to the fine-grained clastic reservoirs with the exploration and development of dense oil and shale gas. The diagenesis of the deep-seated fine-grained clastic reservoirs from the 3rd member of the Funing Formation in the Zhangjiaduo Oil Field is dealt with in this paper on the basis of cast section examination,X-ray diffraction analysis and SEM. The results of research are outlined as follows. (1)The intergranular pores can be well preserved when the disequilibrium compaction took place,and the fine-grained clastic reservoirs with relatively higher compositional maturity and textural maturity are commonly sealed by mudstones;(2 )Abundant micropores are caused by higher contents of matrix due to weakly hydrodynamic conditions during the deposition of the fine-grained clastic reservoirs;(3 )The occurrence of abundant clay minerals leads to the increase of specific surface of the pores and the decrease of the precipitation of siliceous and carbonate cements;(4)The increase of specific surface of

  11. Integration Process Development for Improved Compatibility with Organic Non-Porous Ultralow-k Dielectric Fluorocarbon on Advanced Cu Interconnects

    Science.gov (United States)

    Gu, Xun; Tomita, Yugo; Nemoto, Takenao; Miyatani, Kotaro; Saito, Akane; Kobayashi, Yasuo; Teramoto, Akinobu; Kuroda, Rihito; Kuroki, Shin-Ichiro; Kawase, Kazumasa; Nozawa, Toshihisa; Matsuoka, Takaaki; Sugawa, Shigetoshi; Ohmi, Tadahiro

    2012-05-01

    Integration of an organic non-porous ultralow-k dielectric, fluorocarbon (k= 2.2), into advanced Cu interconnects was demonstrated. The challenges of process-induced damage, such as delamination and variances of both the structure and electrical properties of the fluorocarbon during fabrication, were investigated on Cu/fluorocarbon damascene interconnects. A titanium-based barrier layer, instead of a tantalum-based barrier layer, was used to avoid delamination between Cu and fluorocarbon in Cu/fluorocarbon interconnects. A moisture-hermetic dielectric protective layer was also effective to avoid damage induced by wet chemical cleaning. On the other hand, a post-etching nitrogen plasma treatment to form a stable protective layer on the surface of the fluorocarbon was proposed for the practical minimization of damage introduction to fluorocarbon in the following damascene process, such as post-etching cleaning.

  12. 精细化管理模式下城市设计和附加图则组织编制的工作方法初探%Exploratory Research in Planning Organization of Urban Design and Additional Statutory Planning in Fine-grained Management Mode

    Institute of Scientific and Technical Information of China (English)

    周建非

    2013-01-01

    In the background of fine-grained management of Shanghai, the goal of planning organization of Urban Design and Additional Statutory Planning is increased by a big margin. This article explores various kinds of methods of land transfer with programs and introduces the experience of planning organization of Urban Design and Additional Statutory Planning in key areas of%  在上海城市规划管理日趋精细化的背景下,城市设计和附加图则的组织编制工作的目标要求大幅提高。梳理归纳了上海带方案出让土地的各种模式,总结并介绍近两年来上海重点地区城市设计和附加图则组织编制工作的实践经验。

  13. Investigations for minimising the cracking susceptibility during submerged-arc welding of high-strength fine-grained structural steels StE 890 and StE 960. Final report; Untersuchung zur Minimierung der Rissanfaelligkeit beim UP-Schweissen von hochfesten Feinkornbaustaehlen der Qualitaet StE 890 und StE 960. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Dilthey, U.; Payrebrune, J. de

    2000-01-01

    The investigations focused on strategies for reducing the hydrogen concentration in submerged-arc welding of high-strength fine-grained structural steels S890QL and S960QL. It was found, however, that the temperature curve and especially the cooling time from 800 to 500 C (t{sub 8/5}) and the selected interlayer and holding temperatures are decisive for the quality of the welded seam. [German] Zu Beginn des Projektes wurde das Hauptaugenmerk auf Strategien zur Reduzierung des Wasserstoffgehaltes beim UP-Schweissen von hochfesten Feinkornbaustaehlen der Guete S890QL bzw. S960QL gelegt. Wie sich jedoch recht schnell in den Untersuchungen herausstellte, ist die Waermefuehrung bei diesem Prozess, und hier insbesondere die Abkuehlzeit von 800 C auf 500 C (t{sub 8/5}) sowie die gewaehlte Zwischenlagen- bzw. Haltetemperatur von entscheidender Bedeutung fuer das Erreichen einer den Anspruechen entsprechenden Naht. (orig.)

  14. Preparation of Immobilized Metal Affinity Chromatographic Packings Based on Monodisperse Hydrophilic Non-porous Beads and Their Application

    Institute of Scientific and Technical Information of China (English)

    BO Chun-Miao; GONG Bo-Lin; HU Wen-Zhi

    2008-01-01

    Three hydrophilic immobilized metal affinity chromatographic packings for HPLC have been synthesized by chemical modification of 3.0 μm monodisperse non-porous poly(glycidyl methacrylate-co-ethylenedimethacrylate)(PGMMEDMA)beads.The retention behavior of proteins on the metal ion chelated columns loaded with copper(Ⅱ),nickel(Ⅱ)and zin(Ⅱ)ion was studied.The effect of pH on the protein retention Was investigated on both the naked and metal ion chelated columns in the range from 4.0 to 9.0.Four proteins were quickly separated in 3.0 min with linear gradient elution at a flow rate of 3.0 mL/min by using the synthesized Ni2+ -IDA(iminodiacetic acid)packings.The separation time was shorter than other immobilized metal affinity chromatography reported in the literature.Purification of lysozyme from egg white and trypsin on the commercially available trypsin was performed on the naked-IDA and Cu2+ -IDA columns,respectively.The purities of the purified trypsin and lysozyme were more than 92%and 95%,respectively.

  15. New mechanisms for non-porative ultrasound stimulation of cargo delivery to cell cytosol with targeted perfluorocarbon nanoparticles

    Science.gov (United States)

    Soman, N. R.; Marsh, J. N.; Lanza, G. M.; Wickline, S. A.

    2008-05-01

    The cell membrane constitutes a major barrier for non-endocytotic intracellular delivery of therapeutic molecules from drug delivery vehicles. Existing approaches to breaching the cell membrane include cavitational ultrasound (with microbubbles), electroporation and cell-penetrating peptides. We report the use of diagnostic ultrasound for intracellular delivery of therapeutic bulky cargo with the use of molecularly targeted liquid perfluorocarbon (PFC) nanoparticles. To demonstrate the concept, we used a lipid with a surrogate polar head group, nanogold-DPPE, incorporated into the nanoparticle lipid monolayer. Melanoma cells were incubated with nanogold particles and this was followed by insonication with continuous wave ultrasound (2.25 MHz, 5 min, 0.6 MPa). Cells not exposed to ultrasound showed gold particles partitioned only in the outer bilayer of the cell membrane with no evidence of the intracellular transit of nanogold. However, the cells exposed to ultrasound exhibited numerous nanogold-DPPE components inside the cell that appeared polarized inside intracellular vesicles demonstrating cellular uptake and trafficking. Further, ultrasound-exposed cells manifested no incorporation of calcein or the release of lactate dehydrogenase. These observations are consistent with a mechanism that suggests that ultrasound is capable of stimulating the intracellular delivery of therapeutic molecules via non-porative mechanisms. Therefore, non-cavitational adjunctive ultrasound offers a novel paradigm in intracellular cargo delivery from PFC nanoparticles.

  16. Recovery and Disinfection of Two Human Norovirus Surrogates, Feline Calicivirus and Murine Norovirus, from Hard Nonporous and Soft Porous Surfaces.

    Science.gov (United States)

    Yeargin, Thomas; Fraser, Angela; Huang, Guohui; Jiang, Xiuping

    2015-10-01

    Human norovirus is a leading cause of foodborne disease and can be transmitted through many routes, including environmental exposure to fomites. In this study, both the recovery and inactivation of two human norovirus surrogates, feline calicivirus (FCV) and murine norovirus (MNV), on hard nonporous surfaces (glass) and soft porous surfaces (polyester and cotton) were evaluated by both plaque assay and reverse transcription quantitative PCR method. Two disinfectants, sodium hypochlorite (8.25%) and accelerated hydrogen peroxide (AHP, at 4.25%) were evaluated for disinfection efficacy. Five coupons per surface type were used to evaluate the recovery of FCV and MNV by sonication and stomaching and the disinfection of each surface type by using 5 ml of disinfectant for a contact time of 5 min. FCV at an initial titer of ca. 7 log PFU/ml was recovered from glass, cotton, and polyester at 6.2, 5.4, and 3.8 log PFU/ml, respectively, compared with 5.5, 5.2, and 4.1 log PFU/ml, respectively, for MNV with an initial titer of ca. 6 log PFU/ml. The use of sodium hypochlorite (5,000 ppm) was able to inactivate both FCV and MNV (3.1 to 5.5 log PFU/ml) below the limit of detection on all three surface types. AHP (2,656 ppm) inactivated FCV (3.1 to 5.5 log PFU/ml) below the limit of detection for all three surface types but achieved minimal inactivation of MNV (0.17 to 1.37 log PFU/ml). Reduction of viral RNA by sodium hypochlorite corresponded to 2.72 to 4.06 log reduction for FCV and 2.07 to 3.04 log reduction for MNV on all three surface types. Reduction of viral RNA by AHP corresponded to 1.89 to 3.4 log reduction for FCV and 0.54 to 0.85 log reduction for MNV. Our results clearly indicate that both virus and surface types significantly influence recovery efficiency and disinfection efficacy. Based on the performance of our proposed testing method, an improvement in virus recovery will be needed to effectively validate virus disinfection of soft porous surfaces.

  17. Determination of Ro 48-3656 in rat plasma by reversed-phase high-performance liquid chromatography. Comparison of 1.5-microm nonporous silica to 3.5-microm porous silica analytical columns.

    Science.gov (United States)

    Paasch, B D; Lin, Y S; Porter, S; Modi, N B; Barder, T J

    1997-12-19

    We describe a method for measuring Ro 48-3656 in EDTA rat plasma by neutral pH, reversed-phase high-performance liquid chromatography using a 1.5-microm nonporous silica, C18 analytical column and UV absorbance detection to support pharmacokinetic studies. We also describe a comparison of the 1.5-microm nonporous silica C18 column versus 3.5-microm porous silica C18 columns. The final method using the 1.5-microm nonporous silica column demonstrated good precision (of both quantification and retention time), accuracy and recovery, linearity of dilution and limit of quantification (40 ng/ml Ro 48-3656 using a 20 microl injection). Samples of neat EDTA rat plasma were prepared by ultrafiltration followed by direct injection onto the HPLC column.

  18. Authentic Attributes with Fine-Grained Anonymity Protection

    Science.gov (United States)

    2000-01-01

    pp. 27{36, November 1998. [19] NetZero . www.netzero.com [20] nym.alias.net www.publius.net/n.a.n.html. Homepage of a well known nym server de...Verlag, LNCS vol. 1708, pp. 814{833, 1999. [28] Thomas Wu, Michael Malkin, and Dan Boneh. \\ Building Intrusion Tolerant Applica- tions", in Proceedings

  19. Repeated loading of fine grained soils for pavement design

    OpenAIRE

    Loach, Simon C.

    1987-01-01

    The primary aim of this research was to investigate the behaviour of a clay subjected to a loading regime similar to that experienced by a road subgrade under traffic loading in Great Britain. The material used was Keuper Marl. The samples were anisotropically consolidated in a triaxial apparatus from a slurry which allowed careful control over the stress history and produced uniform samples. The samples were fully instrumented and the apparatus was capable of applying repeated axial and radi...

  20. Sediment Erosion and Redistribution in Fine-Grained Shelf Environments

    Science.gov (United States)

    2007-01-01

    Lions EuroSTRATAFORM sites. Testing and extending our conceptual and numerical sediment transport models at these sites is an important goal of the...measurement sites that are then tested against near-bed field data. In this last phase, detailed modeling of the erosion tests is being carried out to...Interpretation of in-situ measurements using a tridimensional model. 2 Fabres, J., Tesi , T., Velez, J., Batista, F., Lee, C., Calafat, A., Heussner, S

  1. A Fine Grain Sentiment Analysis with Semantics in Tweets

    Directory of Open Access Journals (Sweden)

    Cristobal Barba Gonzalez

    2016-03-01

    Full Text Available Social networking is nowadays a major source of new information in the world. Microblogging sites like Twitter have millions of active users (320 million active users on Twitter on the 30th September 2015 who share their opinions in real time, generating huge amounts of data. These data are, in most cases, available to any network user. The opinions of Twitter users have become something that companies and other organisations study to see whether or not their users like the products or services they offer. One way to assess opinions on Twitter is classifying the sentiment of the tweets as positive or negative. However, this process is usually done at a coarse grain level and the tweets are classified as positive or negative. However, tweets can be partially positive and negative at the same time, referring to different entities. As a result, general approaches usually classify these tweets as “neutral”. In this paper, we propose a semantic analysis of tweets, using Natural Language Processing to classify the sentiment with regards to the entities mentioned in each tweet. We offer a combination of Big Data tools (under the Apache Hadoop framework and sentiment analysis using RDF graphs supporting the study of the tweet’s lexicon. This work has been empirically validated using a sporting event, the 2014 Phillips 66 Big 12 Men’s Basketball Championship. The experimental results show a clear correlation between the predicted sentiments with specific events during the championship.

  2. Simulating the Fluvial Erosion of Fine-Grained River Banks

    Science.gov (United States)

    Darby, S. E.; Sarkkula, J.; Koponen, J.; Kummu, M.

    2007-12-01

    River bank erosion is the product of a suite of specific processes that together contribute significantly to the sediment yielded from river catchments. Many studies have emphasised that hydraulic erosion of bank-toe materials may exert a dominant influence on the long term rate of river bank retreat. Fluvial bank erosion rates are normally quantified using an excess shear stress model of the form E = k(τb-τc)a, where E is the erosion rate per unit time and unit bank area, τb is the boundary shear stress applied by the flow, k and τc are erodibility parameters (erodibility coefficient, k, and critical shear stress, τc), and a is an empirically derived exponent (equated to unity in bank erosion studies). This model has the advantage of simplicity, but in practice difficulties in estimating the values of the erodibility and shear stress parameters seriously inhibit its accuracy. We are seeking to improve the parameterization of the excess shear stress model through the use of field measurements and analytical modelling, at field sites on the Mekong River in Laos. Specifically, τb is estimated using a new model [Kean and Smith, 2006, J. Geophys. Res., 111(4), F04009, doi:10.1029/2006JF000467] of flow over irregular bank topography. Data from our study sites indicate that the form roughness induced by natural topographic bank features (slumps, embayments, etc) is a major component of the spatially-averaged total shear stress, with the skin friction component (i.e, τb) typically an order of magnitude less than the total stress. This indicates that previous bank erosion investigations, that employ estimates of the total shear stress, may grossly misparameterize the true value of τb. To estimate τc, we have employed a Cohesive Strength Meter [CSM, Tolhurst et al., 1999, Estuarine, Coastal & Shelf Sci., 49, 281-294], a jet-testing device that is normally used in studies of the stability of cohesive sediments on inter-tidal flats, but which has not previously been employed in the context of river bank studies. Our data show that values of τc are typically of the order of 1 Pa, again indicating that previous studies may have over-estimated the true critical stress. Moreover, compared to conventional jet-testing devices, the portability and small size of the CSM's sampling chamber, together with the speed of individual tests, allows the collection of large numbers of replicate samples within discrete sedimentary horizons, such that the inherent natural variability of each bank material horizon can be defined. This has allowed us to modify the excess shear stress erosion model to include a probabilistic component associated with the measured statistical distribution of τc for a specific bank-toe material. We have used our data to estimate bank erosion rates for a range of flow discharges, with annual erosion rates subsequently determined by integration across the predictable annual (monsoonal) flow regime. To assess the predictive ability of our model we have compared annual rates of bank-toe retreat (assumed to be a good proxy of bank retreat rates) with estimates of bank retreat derived from analysis of aerial photographs and satellite imagery.

  3. Fine-grained Information Flow for Concurrent Computation

    DEFF Research Database (Denmark)

    Li, Ximeng

    It is essential to protect IT systems against security threats. An example would be the control of aircraft, which uses an internal network that passengers can access. It is important to ensure that malicious code on passenger equipment cannot endanger flight safety. Information flow control...... is an important approach to the protection of systems against such threats. Notable examples include tainting analyses in languages such as Javascript, and program transformations on cryptographic algorithms to avoid information leakage through running time. A wide variety of techniques, including type systems...... and reference monitors, have been proposed in the context of programming languages and process calculi, to enforce such properties. The most widely used definitions of information flow security are noninterference-like properties. For concurrent systems where processes communicate with each other to accomplish...

  4. FABRICATION OF FINE GRAINED DENSE HAP THROUGH SLIP CASTING ROUTE

    Directory of Open Access Journals (Sweden)

    HOWA BEGAM

    2011-02-01

    Full Text Available The purpose of this study is to synthesize nano-grained Calcium Hydroxyapatite (HAp through slip casting technique. For this, hydroxyapatite powders were synthesized using two methods, wet chemical method and Ammoniacal method. The as-prepared powders and calcined powders were characterized using XRD, FTIR, to study the phases of the powders. The hydroxyapatite powder calcined at 1000°C for 2hr was used to prepare 50 vol% slurry using DN40 (sodium olyacrylate as dispersing agent. After slip casting, the green bodies were sintered at different temperatures, 1100, 1200, 1250 and 1300°C with 2hr soaking time. The sintered dense samples were characterized for physical and mechanical behavior.Dense HaP samples were obtained at 1250C.

  5. Newtonian Viscous Flow and Superplasticity in Fine Grained Metallic Alloys

    Science.gov (United States)

    1993-01-31

    Propriedas Mecanicas de Materiales Laminados Mg-9%Li de Pequeno Tamano de Grano", 7th National Conference on Metallurgical Science and Technology...34in Proceedings of Sampe Symposium, Reno, Nevada, (1984). 8 7. 0. A. Ruano and 0. D. Sherby, "Caracterizaci6n Y obtenci6n de materiales superpllsticos

  6. Certificate Revocation Using Fine Grained Certificate Space Partitioning

    Science.gov (United States)

    Goyal, Vipul

    A new certificate revocation system is presented. The basic idea is to divide the certificate space into several partitions, the number of partitions being dependent on the PKI environment. Each partition contains the status of a set of certificates. A partition may either expire or be renewed at the end of a time slot. This is done efficiently using hash chains.

  7. Contaminant transport in fractured fine-grained glacigene sediments

    Energy Technology Data Exchange (ETDEWEB)

    Tsakiroglou, C.D. [Foundation for Research and Technology Hellas, Patras (Greece). Inst. of Chemical Engineering and High Temperature Chemical Processes; Klint, K.E.S.; Gravesen, P. [Geological Survey of Denmark and Greenland, Copenhagen (Denmark); Laroche, C.; Le Thiez, P. [Inst. Francaise du Petrole, Rueil-Malmaison (France)

    2003-07-01

    In this study, multi-scale geological information was collected during extensive fieldwork on a fractured clay-till site situated in Denmark (Ringe site). Meso-scale field data such as fracture spacing/connectivity and hydraulic ''in situ'' tests were combined with micro-scale laboratory studies of mechanical fracture apertures and pore network geometry of fractures and matrix so that a conceptual macro-pore model was established. At the small scale, pore network modeling approach was used to simulate the two-phase flow in single fractures and fracture networks, in the capillary dominated regime. Up-scaling from the pore to the fracture network allowed the estimation of average transport properties and their introduction into a macroscopic simulator of contaminant transport in dual porosity media (SIMUSCOPP). This macroscopic simulator is used for the long-term forecasting of the spatial and temporal evolution of the distribution of a typical LNAPL (creosote) over an extended area around the contaminated site.

  8. Towards Compressive Sampling and Fine-Grained Indoor Fingerprint Positioning

    Directory of Open Access Journals (Sweden)

    Yongle Chen

    2015-01-01

    Full Text Available Location based services (LBS enable various mobile application and improve the human life significantly. GPS has largely solved the problem for outdoor positioning. However, the accuracy and usability of positioning algorithm remains a grand challenge for indoor scenarios. WiFi-based fingerprint positioning has attracted lots of research attentions, for the advantage of leveraging existing indoor WLAN infrastructure. But the positioning accuracy and fingerprint sampling are both challenge for WiFi-based fingerprint positioning. This paper proposed a trade-off method between accurate positioning and tedious sampling. It first utilizes the Gaussian process model to complete compressive sampling instead of the whole-cell sampling, and then proposed an improved K-Means method based on the similarity threshold to increase the performance accuracy. Our experiment shows our improve method can get better accuracy with 2m median error which approximates results of the real raw data. Meanwhile, our Gaussian process model also largely reduces the tedious sampling.

  9. Monocle: Dynamic, Fine-Grained Data Plane Monitoring

    OpenAIRE

    Peresini, Peter; Kuzniar, Maciej; Kostic, Dejan

    2015-01-01

    Ensuring network reliability is important for satisfying service-level objectives. However, diagnosing network anomalies in a timely fashion is difficult due to the complex nature of network configurations. We present Monocle — a system that uncovers forwarding problems due to hardware or software failures in switches, by verifying that the data plane corresponds to the view that an SDN controller installs via the control plane. Monocle works by systematically probing the switch data plane; t...

  10. Fine Grained Tungsten Claddings for Cermet Based NTP Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In October 2011, NASA initiated the Nuclear Cryogenic Propulsion Stage (NCPS) program to evaluate the feasibility and affordability of Nuclear Thermal Propulsion...

  11. The Challenges of Implementing Fine-Grained Power Gating

    NARCIS (Netherlands)

    Niedermeier, A.; Svarstad, Kjetil; Bouwens, Frank; Hulzink, Jos; Huisken, Jos

    2010-01-01

    Power consumption in digital systems, especially in portable devices, is a crucial design factor. Due to downscaling of technology, dynamic switching power is not the only relevant source of power consumption anymore as power dissipation caused by leakage currents increases. Even though power gating

  12. DC circuits: I. Evidence for fine grained contextual dependence

    Science.gov (United States)

    John, Ignatius

    2017-01-01

    This is the first part of a broader study, exploring the contextual variations of the responses of 149 first year (non-physics major) university students at two South African universities in Cape Town. The data analysis was done in terms of the (i) forced choice responses (FCR), (ii) free written responses and (iii) personal interviews. This paper presents the development of the instrument (aspects of circuits questionnaire, or ACQ) used in the exploratory study and the results obtained from the FCR analysis of 60 students. The results showed that the student responses are triggered by the context framed by the questions and the results obtained from investigations using light bulbs cannot be generalised and may be reinterpreted. This article was extracted from the PhD thesis submitted to Faculty of Science, University of Cape Town.

  13. Fine-grained Information Flow for Concurrent Computation

    DEFF Research Database (Denmark)

    Li, Ximeng

    ” and “what” into consideration, emphasizing the importance of the integrity case where the former is more sensitive than the latter. This case captures the effect of Message Authentication Codes (MAC) and the consequence of Denial of Service (DoS) attacks. It is also proved that the property degenerates......It is essential to protect IT systems against security threats. An example would be the control of aircraft, which uses an internal network that passengers can access. It is important to ensure that malicious code on passenger equipment cannot endanger flight safety. Information flow control...... is an important approach to the protection of systems against such threats. Notable examples include tainting analyses in languages such as Javascript, and program transformations on cryptographic algorithms to avoid information leakage through running time. A wide variety of techniques, including type systems...

  14. Fine-grained code changes and bugs: Improving bug prediction

    OpenAIRE

    Giger, Emanuel

    2012-01-01

    Software development and, in particular, software maintenance are time consuming and require detailed knowledge of the structure and the past development activities of a software system. Limited resources and time constraints make the situation even more difficult. Therefore, a significant amount of research effort has been dedicated to learning software prediction models that allow project members to allocate and spend the limited resources efficiently on the (most) critical parts of their s...

  15. Fine grained electromagnetic lead-liquid scintillator calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, L.; Fluri, L.; Perrin, D.; Vuilleumier, J.M. (Neuchatel Univ. (Switzerland)); Bonesini, M.; Cavalli, D.; Costa, G.; Mandelli, L.; Mazzanti, M.; Tamborini, M. (Istituto Nazionale di Fisica Nucleare, Milan (Italy))

    1983-02-15

    A new technique using liquid scintillator contained in teflon tubes to build a low cost high spatial resolution electromagnetic sampling calorimeter is described. Test results and comparison with a Monte Carlo simulation are presented.

  16. Casting fine grained, fully dense, strong inorganic materials

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Sam W.; Spencer, Larry S.; Phillips, Michael R.

    2015-11-24

    Methods and apparatuses for casting inorganic materials are provided. The inorganic materials include metals, metal alloys, metal hydrides and other materials. Thermal control zones may be established to control the propagation of a freeze front through the casting. Agitation from a mechanical blade or ultrasonic energy may be used to reduce porosity and shrinkage in the casting. After solidification of the casting, the casting apparatus may be used to anneal the cast part.

  17. Fine-grained entanglement loss along renormalization group flows

    CERN Document Server

    Latorre, J I; Rico, E; Vidal, G

    2004-01-01

    We explore entanglement loss along renormalization group trajectories as a basic quantum information property underlying their irreversibility. This analysis is carried out for the quantum Ising chain as a transverse magnetic field is changed. We consider the ground-state entanglement between a large block of spins and the rest of the chain. Entanglement loss is seen to follow from a rigid reordering, satisfying the majorization relation, of the eigenvalues of the reduced density matrix for the spin block. More generally, our results indicate that it may be possible to prove the irreversibility along RG trajectories from the properties of the vacuum only, without need to study the whole hamiltonian.

  18. Friction stir weld tools having fine grain structure

    Energy Technology Data Exchange (ETDEWEB)

    Grant, Glenn J.; Frye, John G.; Kim, Jin Yong; Lavender, Curt A.; Weil, Kenneth Scott

    2016-03-15

    Tools for friction stir welding can be made with fewer process steps, lower cost techniques, and/or lower cost ingredients than other state-of-the-art processes by utilizing improved compositions and processes of fabrication. Furthermore, the tools resulting from the improved compositions and processes of fabrication can exhibit better distribution and homogeneity of chemical constituents, greater strength, and/or increased durability. In one example, a friction stir weld tool includes tungsten and rhenium and is characterized by carbide and oxide dispersoids, by carbide particulates, and by grains that comprise a solid solution of the tungsten and rhenium. The grains do not exceed 10 micrometers in diameter.

  19. 阶梯式精细化饮食管理对肝硬化并发消化道出血患者饮食控制的影响%Effects of stepwise and fine-grained dietary management on the diet control of liver cirrhosis patients complicated with gastrointestinal hemorrhage

    Institute of Scientific and Technical Information of China (English)

    邹小兰; 魏建红; 史晓芬; 惠菊芬; 过孝

    2016-01-01

    目的:探讨阶梯式精细化饮食管理对肝硬化并发消化道出血患者开放饮食后饮食干预的影响。方法将80例肝硬化并发消化道出血患者采用随机数字表法随机分为试验组41例及对照组39例。试验组予阶梯式精细化饮食管理,对照组予常规饮食干预。在入院时、开放饮食时、出院时、出院2个月,监测2组患者饮食符合率、饮食知识掌握情况、营养不良风险的变化。在出院后1年,监测2组患者再出血发生率的变化。结果肝硬化并发消化道出血患者中,Child-Pugh C级患者的营养不良风险率较Child-Pugh B级者高(Z=-4.3,P<0.05),文化程度低者较文化程度高者高(r=-0.453,P<0.05)。试验组的饮食知识掌握度在出院时为80(70,84)分,明显优于对照组的52(42,64)分,饮食符合率在出院2个月为86(76,91)%,显著高于对照组的53(46,57)%,营养风险评分在出院2个月为1(1,2)分,显著低于对照组的2(1,3)分,1年内再次出血发生率为14.6%(6/41),显著小于对照组的35.9%(14/39),2组比较差异有统计学意义(χ2=4.266~51.232,均P<0.05)。结论阶梯式精细化饮食管理能提高患者的饮食知识掌握率、饮食符合率及营养状况,降低再次出血的发生,值得在肝硬化并发消化道出血患者的临床护理中推广及应用。%Objective To evaluate the effects of stepwise and fine-grained dietary management on the diet control of liver cirrhosis patients complicated with gastrointestinal hemorrhage. Methods Eighty liver cirrhosis patients complicated with gastrointestinal hemorrhage were assigned to experimental group (41 cases) and control group(39 cases) by random digits table method. The patients in experimental group were treated with stepwise and fine-grained dietary management and the patients in control group were given conventional dietary treatments. The

  20. Thermal desorption characteristics of CO, O2 and CO2 on non-porous water, crystalline water and silicate surfaces at sub-monolayer and multilayer coverages

    CERN Document Server

    Noble, J A; Dulieu, F; Fraser, H J

    2011-01-01

    The desorption characteristics of molecules on interstellar dust grains are important for modelling the behaviour of molecules in icy mantles and, critically, in describing the solid-gas interface. In this study, a series of laboratory experiments exploring the desorption of three small molecules from three astrophysically relevant surfaces are presented. The desorption of CO, O2 and CO2 at both sub-monolayer and multilayer coverages was investigated from non-porous water, crystalline water and silicate surfaces. Experimental data was modelled using the Polanyi-Wigner equation to produce a mathematical description of the desorption of each molecular species from each type of surface, uniquely describing both the monolayer and multilayer desorption in a single combined model. The implications of desorption behaviour over astrophysically relevant timescales are discussed.

  1. Three dimensional analysis of the pore space in fine-grained Boom Clay, using BIB-SEM (broad-ion beam scanning electron microscopy), combined with FIB (focused ion-beam) serial cross-sectioning, pore network modeling and Wood's metal injection

    Science.gov (United States)

    Hemes, Susanne; Klaver, Jop; Desbois, Guillaume; Urai, Janos

    2014-05-01

    The Boom Clay is, besides the Ypresian clays, one of the potential host rock materials for radioactive waste disposal in Belgium (Gens et al., 2003; Van Marcke & Laenen, 2005; Verhoef et al., 2011). To access parameters, which are relevant for the diffusion controlled transport of radionuclides in the material, such as porosity, pore connectivity and permeability, it is crucial to characterize the pore space at high resolution (nm-scale) and in 3D. Focused-ion-beam (FIB) serial cross-sectioning in combination with high resolution scanning electron microscopy (SEM), pore network modeling, Wood's metal injection and broad-ion-beam (BIB) milling, constitute a superior set of methods to characterize the 3D pore space in fine-grained, clayey materials, down to the nm-scale resolution. In the present study, we identified characteristic 3D pore space morphologies, determined the 3D volume porosity of the material and applied pore network extraction modeling (Dong and Blunt, 2009), to access the connectivity of the pore space and to discriminate between pore bodies and pore throats. Moreover, we used Wood's metal injection (WMI) in combination with BIB-SEM imaging to assess the pore connectivity at a larger scale and even higher resolution. The FIB-SEM results show a highly (~ 90 %) interconnected pore space in Boom Clay, down to the resolution of ~ 3E+03 nm³ (voxel-size), with a total volume porosity of ~ 20 %. Pore morphologies of large (> 5E+08 nm³), highly interconnected pores are complex, with high surface area to volume ratios (shape factors G ~ 0.01), whereas small (BIB-SEM, down to a resolution of ~ 50 nm² pixel-size, indicates an interconnected porosity fraction of ~ 80 %, of a total measured 2D porosity of ~ 20 %. Determining and distinguishing between pore bodies and pore throats enables us to compare 3D FIB-SEM pore-size distributions to 2D BIB-SEM data, as well as MIP data. Results show a good agreement between the 2D BIB-SEM and 3D FIB-SEM inferred pore

  2. Solidification Microstructure, Fracture Behavior and In-Situ Toughening of TiC-TiB2 Fine-grained Composite Ceramics%TiC-TiB2细晶陶瓷凝固组织、断裂行为与原位增韧

    Institute of Scientific and Technical Information of China (English)

    赵忠民; 张龙; 宋义刚; 何建强

    2011-01-01

    Solidification structure and crystal growth of the TiC-TiBz fine-grained ceramics which was prepared by combustion synthesis under high gravity were investigated, and the relationship between microstructure and fracture behavior as well as toughening mechanism was analyzed by XRD (X-ray diffraction) , FESEM (field emission scanning electron microscope) and EDS (energy dispersive spectrometer). The results show that the composite ceramics matrix is composed of a lot of fine TiB2 platelets and irregular TiC grain surrounded the TiBz platelets. The formation of TiB2 platelets is resulted from faceted crystal growth while irregular TiC grains are the results of non-faceted crystal growth and high growth velocity. Relative density, Vickers hardness, bending strength and fracture toughness of the ceramics reach 98. 6% , 21. 8 Gpa, 650MPa and 12. 5 Mpa · m1/2, respectively. Ceramic toughening mechanism is attributed to the co-operation of crack deflection, crack-bridging and pull-up by small-size TiBz platelets and frictionally-interlocking in-situ toughening effects.%通过采用超重力下燃烧合成制备TiC-TiB2细晶陶瓷,研究了陶瓷凝固组织与晶体生长特征,探讨了陶瓷显微组织与断裂行为、增韧机制的关系.XRD、FESEM与EDS分析表明,TiC-TiB2复合陶瓷基体主要由大量细小的TiB2片晶及分布其周围的形状不规则的TiC相构成,TiB2片晶的形成是因其小平面晶体生长特性所致,而不规则TiC的晶体形貌则是因非小平面晶体生长特性及高的生长速率所造成的.陶瓷相对密度、硬度(HV)、弯曲强度及断裂韧度分别为98.6%、21.8 GPa、650MPa、12.5 MPa ·m1/2,并且陶瓷增韧是小尺寸TiB片晶的裂纹偏转、裂纹桥接、片晶拔出及摩擦互锁原位增韧机制协同作用的结果.

  3. Aerogels of 1D Coordination Polymers: From a Non-Porous Metal-Organic Crystal Structure to a Highly Porous Material

    Directory of Open Access Journals (Sweden)

    Adrián Angulo-Ibáñez

    2016-01-01

    Full Text Available The processing of an originally non-porous 1D coordination polymer as monolithic gel, xerogel and aerogel is reported as an alternative method to obtain novel metal-organic porous materials, conceptually different to conventional crystalline porous coordination polymer (PCPs or metal-organic frameworks (MOFs. Although the work herein reported is focused upon a particular kind of coordination polymer ([M(μ-ox(4-apy2]n, M: Co(II, Ni(II, the results are of interest in the field of porous materials and of MOFs, as the employed synthetic approach implies that any coordination polymer could be processable as a mesoporous material. The polymerization conditions were fixed to obtain stiff gels at the synthesis stage. Gels were dried at ambient pressure and at supercritical conditions to render well shaped monolithic xerogels and aerogels, respectively. The monolithic shape of the synthesis product is another remarkable result, as it does not require a post-processing or the use of additives or binders. The aerogels of the 1D coordination polymers are featured by exhibiting high pore volumes and diameters ranging in the mesoporous/macroporous regions which endow to these materials the ability to deal with large-sized molecules. The aerogel monoliths present markedly low densities (0.082–0.311 g·cm−3, an aspect of interest for applications that persecute light materials.

  4. ASTM D395 Short-Term Compression Set of Solid (Non-Porous) Siloxanes: SE 1700, Sylgard 184, and "New" M9787

    Energy Technology Data Exchange (ETDEWEB)

    Small, Ward [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pearson, Mark A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jensen, Wayne A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-09-13

    Compression set of solid (non-porous) Dow Corning SE 1700, Sylgard 184, and “new” M9787 siloxane elastomers was measured according to ASTM D395 Method B. Specimens of SE 1700 were made using (1) the manufacturer’s suggested cure of 150°C for 30 min and (2) an extended cure of 60°C for 6 h and 150°C for 1 h followed by a post-cure under nitrogen purge at 125°C for 12 h. Four specimens of each material were aged at 25-27% compressive strain at 70°C under nitrogen purge for 70 h. Final thickness of each specimen was measured after a 30-min cooling/relaxation period, and compression set relative to deflection was calculated. The average compression set relative to deflection was 6.0% for SE 1700 made using the extended cure and post-cure, 11.3% for SE 1700 made using the manufacturer’s suggested cure, 12.1% for Sylgard 184, and 1.9% for M9787. The extended cure and post-cure reduced the amount of compression set in SE 1700.

  5. A facile approach to the synthesis of non-porous and microporous sub-micron spherical zirconia and alumina-zirconia solid solution.

    Science.gov (United States)

    Ghotbi, Mohammad Yeganeh; Nasiri, Vida; Rafiee, Mehdi

    2013-01-01

    Amorphous monodisperse sub-micron spherical zirconia and alumina/zirconia solid solution particles were prepared by hydrolysis of zirconium and aluminum salts in ethanol. The heat-treatment process of the amorphous materials in air atmosphere at 500°C for 2h leaded to the production of non-porous zirconia and alumina/zirconia solid solution in tetragonal phase. The alkaline etching process of the as-prepared alumina/zirconia solid solution resulted in the formation of mono-modal microporous material with specific surface area of 125.0 m(2) g(-1) in comparison with 2. 9m(2) g(-1) for the parent material. Thermal analysis of the solid solution revealed that the incorporation of aluminum ions in the zirconia structure has decreased the phase transformation temperature from amorphous to crystalline structure. Moreover, optical study confirmed the presence of oxygen vacancy defect by substitution of tetravalent cations, Zr(4+) by trivalent cations, Al(3+) in zirconia lattice.

  6. Different effects of surface heterogeneous atoms of porous and non-porous carbonaceous materials on adsorption of 1,1,2,2-tetrachloroethane in aqueous environment.

    Science.gov (United States)

    Chen, Weifeng; Ni, Jinzhi

    2017-05-01

    The surface heterogeneous atoms of carbonaceous materials (CMs) play an important role in adsorption of organic pollutants. However, little is known about the surface heterogeneous atoms of CMs might generate different effect on adsorption of hydrophobic organic compounds by porous carbonaceous materials - activated carbons (ACs) and non-porous carbonaceous materials (NPCMs). In this study, we observed that the surface oxygen and nitrogen atoms could decrease the adsorption affinity of both ACs and NPCMs for 1,1,2,2-tetrachloroethane (TeCA), but the degree of decreasing effects were very different. The increasing content of surface oxygen and nitrogen ([O + N]) caused a sharper decrease in adsorption affinity of ACs (slope of lg (kd/SA) vs [O + N]: -0.098∼-0.16) than that of NPCMs (slope of lg (kd/SA) vs [O + N]: -0.025∼-0.059) for TeCA. It was due to the water cluster formed by the surface hydrophilic atoms that could block the micropores and generate massive invalid adsorption sites in the micropores of ACs, while the water cluster only occupied the surface adsorption sites of NPCMs. Furthermore, with the increasing concentration of dissolved TeCA, the effect of surface area on adsorption affinity of NPCMs for TeCA kept constant while the effect of [O + N] decreased due to the competitive adsorption between water molecule and TeCA on the surface of NPCMs, meanwhile, both the effects of micropore volume and [O + N] on adsorption affinity of ACs for TeCA were decreased due to the mechanism of micropore volume filling. These findings are valuable for providing a deep insight into the adsorption mechanisms of CMs for TeCA.

  7. Tenacity of human norovirus and the surrogates feline calicivirus and murine norovirus during long-term storage on common nonporous food contact surfaces.

    Science.gov (United States)

    Mormann, Sascha; Heißenberg, Cathrin; Pfannebecker, Jens; Becker, Barbara

    2015-01-01

    The transfer of human norovirus (hNV) to food via contaminated surfaces is highly probable during food production, processing, and preparation. In this study, the tenacity of hNV and its cultivable surrogates feline calicivirus (FCV) and murine norovirus (MNV) on two common nonporous surface materials at two storage temperatures was directly compared. Virus titer reduction on artificially inoculated stainless steel and plastic carriers was monitored for 70 days at room temperature and at 7°C. Viruses were recovered at various time points by elution. Genomes from intact capsids (hNV, FCV, and MNV) were quantified with real-time reverse transcription (RT) PCR, and infectivity (FCV and MNV) was assessed with plaque assay. RNase treatment before RNA extraction was used to eliminate exposed RNA and to assess capsid integrity. No significant differences in titer reduction were found between materials (stainless steel or plastic) with the plaque assay or the real-time quantitative RT-PCR. At room temperature, infectious FCV and MNV were detected for 7 days. Titers of intact hNV, FCV, and MNV capsids dropped gradually and were still detectable after 70 days with a loss of 3 to 4 log units. At 7°C, the viruses were considerably more stable than they were at room temperature. Although only MNV infectivity was unchanged after 70 days, the numbers of intact capsids (hNV, FCV, and MNV) were stable with less than a 1-log reduction. The results indicate that hNV persists on food contact surfaces and seems to remain infective for weeks. MNV appears to be more stable than FCV at 7°C, and thus is the most suitable surrogate for hNV under dry conditions. Although a perfect quantitative correlation between intact capsids and infective particles was not obtained, real-time quantitative RT-PCR provided qualitative data about hNV inactivation characteristics. The results of this comparative study might support future efforts in assessment of foodborne virus risk and food safety.

  8. Application of Nonporous Hollow Fiber Membrane Contactor in CO2 Removal%中空纤维致密膜基吸收法在CO2脱除中的应用

    Institute of Scientific and Technical Information of China (English)

    姜尚; 孙承贵; 贾静璇; 康国栋; 曹义鸣; 袁权

    2013-01-01

    In order to investigate the application potential of hollow fiber membrane contactors, a commercial nonporous polyimide hollow fiber membrane contactor (φ200) was tested by using tap water and seawater as absorbents to separate the CO2 from the gas mixture of CO2 and N2. The effects of liquid flow rate, liquid pressure, gas flow rate and gas pressure on the removal efficiency and overall mass transfer coefficient of CO2 were investigated. The experimental results indicate that the membrane resistance and liquid film resistance control the mass transfer when tap water and seawater are employed as absorbents. Furthermore, the removal efficiency is enhanced when the liquid/gas flow rate ratio increases. The nonporous hollow fiber contactor could perform a high CO2 removal with efficiency over 70%by optimizing the operation conditions. Finally, a stable operation process was achieved. This smooth mass transfer process indicates that the nonporous hollow fiber membrane eliminates bubbling problem and weeping problem that are frequently encountered in microporous hollow fiber contactor. Therefore, the non-porous hollow fiber contactor used in this experiment has great potential for application as a gas-liquid contactor.%  以商业φ200聚酰亚胺中空纤维致密膜大组件为接触器,淡水和海水为吸收剂,进行了CO2/N2混合气中CO2的脱除实验。考察了气液相压力和流量对CO2脱除率和过程总传质系数的影响。结果显示,液相压力对膜接触器的影响不大,而加大液/气相流量比可以提高CO2的脱除效率,通过控制操作条件可使膜接触器的CO2脱除率在70%以上。实验过程中,气液两相压力可在较宽范围内独立操作,且无鼓泡和漏液现象发生。研究表明中空纤维致密膜基接触器在CO2气体分离领域具有很好的应用潜力和前景。

  9. Method and apparatus for separating hydrogen from gas mixtures by diffusion through a nonporous wall. Verfahren und Vorrichtung zur Abtrennung von Wasserstoff aus Gasgemischen durch Diffusion durch eine nichtporoese Wand

    Energy Technology Data Exchange (ETDEWEB)

    Behr, F.; Weirich, W.; Schulten, R.

    1983-06-23

    A Cu-saturated alloy containing 10-30% Ti, 3-10% V, 25 wt% Nb, and >30% Ta is used as a nonporous membrane for the separation of H from gas mixtures in nuclear reactors by selective diffusion. The primary side of the alloy contacting the gas mixture is coated with a Pd/Cu or Pd/Ag alloy, whereas the secondary side contacts a Na-K, Li, or Ba-Mg-Ca melt, the affinity of which to H is higher than that of the Ta-base alloy and the Pd-Cu or Pd-Ag coating. The alkali or alkaline-earth metal melt increases the diffusion rate of H through the membrane and prevents the formation of brittle hydrides in the membrane.

  10. Rigid, non-porous and tunable hybrid p-aminobenzoate/TiO2 materials: Toward a fine structural determination of the immobilized RhCl(Ph3)3 complex

    KAUST Repository

    Espinas, Jeff

    2015-05-01

    By exchange of ligands, Wilkinson complex RhCl(PPh3)3 are immobilized on p-aminobenzoate/TiO2 with different organic loading (6, 11 and 16%). This new hybrid material exhibit a linear correlation between the ligand content of the starting TiO2 and the rhodium loading, showing the accessibility of all surfaces amines fonctions on the non-porous parent materials. 1H, 13C, and 1D, 2D INAQUEDATE refocused and J-resolved 31P solid-state NMR confirm the well-defined structure [(≡TiO)2(n{right tail}2-O2C-C6H4-NH2)RhCl-cis-(PPh3)2]. New immobilized catalysts show interesting activity in cyclohexene hydroformylation.

  11. Single crystal to single crystal (SC-to-SC) transformation from a nonporous to porous metal-organic framework and its application potential in gas adsorption and Suzuki coupling reaction through postmodification.

    Science.gov (United States)

    Sen, Rupam; Saha, Debraj; Koner, Subratanath; Brandão, Paula; Lin, Zhi

    2015-04-07

    A new amino-functionalized strontium-carboxylate-based metal-organic framework (MOF) has been synthesized that undergoes single crystal to single crystal (SC-to-SC) transformation upon desolvation. Both structures have been characterized by single-crystal X-ray analysis. The desolvated structure shows an interesting 3D porous structure with pendent -NH2 groups inside the pore wall, whereas the solvated compound possesses a nonporous structure with DMF molecules on the metal centers. The amino group was postmodified through Schiff base condensation by pyridine-2-carboxaldehyde and palladium was anchored on that site. The modified framework has been utilized for the Suzuki cross-coupling reaction. The compound shows high activity towards the C-C cross-coupling reaction with good yields and turnover frequencies. Gas adsorption studies showed that the desolvated compound had permanent porosity and was microporous in nature with a BET surface area of 2052 m(2)  g(-1). The material also possesses good CO2 (8 wt %) and H2 (1.87 wt %) adsorption capabilities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. INVESTIGATION ON MARTENSITIC TRANSFORMATION AND FIELD-INDUCED TWO-WAY SHAPE MEMORY EFFECT OF Ni-Mn-Ga ALLOY%哈斯勒合金Ni-Mn-Ga的马氏体相变和磁增强双向形状记忆效应

    Institute of Scientific and Technical Information of China (English)

    柳祝红; 胡凤霞; 王文洪; 陈京兰; 吴光恒; 高书侠; 敖玲

    2001-01-01

    通过研究铁磁性金属间化合物Ni2+xMn1-xGa(x=-0.1,0,0.08,0.13,0.18,0.2)和Ni2-xMn1+x/2Ga1+x/2(x=-0.1,0,0.04,0.06,0.1)两个系列多晶样品的交流磁化率随温度的变化行为,得到了化合物在不同组分下的马氏体相变温度TM和居里温度TC.发现随着Ni成分的增加,前者的马氏体相变温度Tm增加,而居里温度TC降低,后者的马氏体相变温度Tm和居里温度TC均是先增大后减小.报道了Tm在室温附近的单晶样品Ni52Mn24Ga24的磁场增强双向形状记忆效应.发现伴随着马氏体相变,样品在[001]方向可产生1.2%的收缩.如果在该方向施加1.2T的偏磁场可以使该应变值增大到4.0%.而垂直于[001]方向施加1.2T的偏磁场时,在[001]方向产生1.6%的膨胀.阐明了产生大应变的原因并非相界移动,而是单晶的杂散内应力小和外加磁场通过孪晶界移动使马氏体变体重组的共同结果.%The martensitic phase transformation temperature,Tm and the Curie temperature, TC, of polycrystalline samples Ni2+xMn1-xGa(x=-0.1,0,0.08,0.13,0.18,0.2) and Ni2-xMn1+x/2Ga1+x/2(x=-0.1,0,0.04,0.06,0.1) have been investigated by measuring the temperature dependence of alternating-current susceptibility. It was found that, with the increase of Ni content, TC decreases and Tm increases for Ni2+xMn1-xGa, and both TC and Tm increase first and decrease afterwards for Ni2-xMn1+x/2Ga1+x/2. Stress-free and two-way thermoelastic shape memory, with 1.2% strain, has been found in single crystal Ni52Mn24Ga24. The deformation can be enhanced more than three times, up to 4.0% shrinkage with a bias field 1.2T applied along the measurement direction. The origin of large recoverable strain should be attributed to the low level of internal stress and the field-induced rearrangement of martensitic variants through twin boundary motion rather than the phase boundary motion.

  13. Temperature Dependence of Magnetic-Field-Induced Strain and Energy Loss in Twin Boundary Motions for NiMnGa and NiMnFeGa Crystals%NiMnGa和NiMnFeGa单晶磁感生应变的温度依赖性及孪晶界移动的能量损耗

    Institute of Scientific and Technical Information of China (English)

    崔玉亭; 武亮; 张健; 吴振兴; 潘复生

    2010-01-01

    在提拉法生长出Ni_(52)Mn_(16.4)Fe_8Ga_(23.6)单晶样品的基础上,测量了其相变应变和磁感生应变.与Ni_(52)Mn_(24.5)Ga_(23.5)单晶样品的实验结果对比分析可知,两种材料都具有较大的自发相变应变量和磁感生应变量,但Ni_(52)Mn_(16.4)Fe_8Ga_(23.6)单晶的磁感生应变具有较好的温度稳定性.依据实验结果和利用热动力学原理,分别计算了两种单晶样品磁感生应变升降磁场一个循环过程中孪晶界移动的能量损耗,给出了能量损耗随温度变化的关系,结果表明磁感生应变量可定性反映一个循环过程中孪晶界移动的能量损耗.

  14. NiMnGa铁磁性形状记忆合金颗粒/树脂智能复合材料的研究进展%Research Progress in NiMnGa Ferromagnetic Shape Memory Alloy Particles/Polymer Smart Composite

    Institute of Scientific and Technical Information of China (English)

    田兵; 陈枫; 佟运祥; 李莉; 郑玉峰

    2009-01-01

    介绍了NiMnGa铁磁性形状记忆合金颗粒/树脂智能复合材料的制备、温度场和磁场响应特性以及阻尼性能的最新研究进展.与NiMnGa多晶材料相比,NiMnGa铁磁性形状记忆合金颗粒/树脂智能复合材料具有很好的加工成型性能,克服了NiMnGa多晶材料的脆性,同时表现出良好的温度场响应特性和阻尼性能,是一种很有发展前景的新型驱动器材料和阻尼材料.在磁场响应方面,新型铁磁性形状记忆合金(NiCoMnIn、NiCoMnSb、NiCoMnGa)/树脂智能复合材料将是未来研究的重点.

  15. Novel Methods for Activity Classification and Occupany Prediction Enabling Fine-grained HVAC Control

    OpenAIRE

    Rana, Rajib; Kusy, Brano; Wall, Josh; Hu, Wen

    2014-01-01

    Much of the energy consumption in buildings is due to HVAC systems, which has motivated several recent studies on making these systems more energy- efficient. Occupancy and activity are two important aspects, which need to be correctly estimated for optimal HVAC control. However, state-of-the-art methods to estimate occupancy and classify activity require infrastructure and/or wearable sensors which suffers from lower acceptability due to higher cost. Encouragingly, with the advancement of th...

  16. Beyond epistemological deficits: Incorporating flexible epistemological views into fine-grained cognitive dynamics

    CERN Document Server

    Gupta, Ayush

    2010-01-01

    Researchers have argued against deficit-based explanations of students' troubles with mathematical sense-making, pointing instead to factors such as epistemology: students' beliefs about the nature of knowledge and learning can hinder them from activating and integrating productive knowledge they have. But such explanations run the risk of substituting an epistemological deficit for a concepts/skills deficit. Our analysis of an undergraduate engineering major avoids this "deficit trap" by incorporating multiple, context-dependent epistemological stances into his cognitive dynamics.

  17. Jagged Tiling for Intra-tile Parallelism and Fine-Grain Multithreading

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Sunil; Manzano Franco, Joseph B.; Marquez, Andres; Feo, John T.; Gao, Guang R.

    2015-05-01

    In this paper, we have developed a novel methodology that takes into consideration multithreaded many-core designs to better utilize memory/processing resources and improve memory residence on tileable applications. It takes advantage of polyhedral analysis and transformation in the form of PLUTO, combined with a highly optimized finegrain tile runtime to exploit parallelism at all levels. The main contributions of this paper include the introduction of multi-hierarchical tiling techniques that increases intra tile parallelism; and a data-flow inspired runtime library that allows the expression of parallel tiles with an efficient synchronization registry. Our current implementation shows performance improvements on an Intel Xeon Phi board up to 32.25% against instances produced by state-of-the-art compiler frameworks for selected stencil applications.

  18. A fine-grained parallel algorithm for the cyclic flexible job shop problem

    Directory of Open Access Journals (Sweden)

    Bożejko Wojciech

    2017-06-01

    Full Text Available In this paper there is considered a flexible job shop problem of operations scheduling. The new, very fast method of determination of cycle time is presented. In the design of heuristic algorithm there was the neighborhood inspired by the game of golf applied. Lower bound of the criterion function was used in the search of the neighborhood.

  19. Nanocrystalline and Ultra-Fine Grained Tungsten for Kinetic Energy Penetrator and Warhead Liner Applications

    Science.gov (United States)

    2007-06-01

    Tungsten Sheet, J. Less Common Metals, 13, 141-155. Jain, M., Skandan, G., Martin , K., Kapoor, D., Cho, K., Klotz, B., Dowding, R., Agarawal, D., and...2758. Zhilyaev, A.P., Nurislamova, G.V., Kim, B.K., Baro , M.D., Szpunar, J.A., and Langdon, T.G., 2003: Experimental Parameters Influencing Grain

  20. Shock-induced fine-grained recrystallization of olivine - Evidence against subsolidus reduction of Fe/2+/

    Science.gov (United States)

    Ahrens, T. J.; Tsay, F.-D.; Live, D. H.

    1976-01-01

    Electron spin resonance (ESR) studies have been carried out on three single grains of terrestrial olivine (Fo90) shock loaded along the 010 line to peak pressures of 280, 330, and 440 kbar. The results indicate that neither metallic Fe similar to that observed in returned lunar soils nor paramagnetic Fe(3+) caused by oxidation of Fe(2+) has been produced in these shock experiments. Trace amounts of Mn (2+) have been detected in both shocked and unshocked olivine. The ESR signals of Mn(2+) show spectral features which are found to correlate with the degree of shock-induced recrystallization observed petrographically. The increasing mass fraction of recrystallized olivine correlates with increasing shock pressures. This phenomenon is modelled assuming it results from the progressive effect of the shock-induced transformation of the olivine to a yet unknown high-pressure phase and its subsequent reversion to the low-pressure olivine phase. The mass fraction of recrystallized material is predicted to be nearly linear with shock pressure.

  1. Evaluation of a Non-Nuclear Soil Density Gauge on Fine-Grained Soils

    Science.gov (United States)

    2013-05-01

    three different moisture contents for testing: the soil being dry of the soil’s optimum moisture content ( OMC ), at the OMC , and wet of the OMC . Then...Moisture Content ( OMC ) Maximum Dry Density (MDD) Atterberg Limits ASTM D 4318 Plastic Limit (PL) Liquid Limit (LL) Plasticity Index (PI...Geotechnical properties of soils used for evaluation. Soil ID Description Atterberg Limits Grain size (percent by weight) Cu Cc MDD (pcf) OMC (%) Gs

  2. Constructing a taxonomy of fine-grained human movement and activity motifs through social media

    CERN Document Server

    Frank, Morgan R; Mitchell, Lewis; Bagrow, James P; Dodds, Peter Sheridan; Danforth, Christopher M

    2014-01-01

    Profiting from the emergence of web-scale social data sets, numerous recent studies have systematically explored human mobility patterns over large populations and large time scales. Relatively little attention, however, has been paid to mobility and activity over smaller time-scales, such as a day. Here, we use Twitter to identify people's frequently visited locations along with their likely activities as a function of time of day and day of week, capitalizing on both the content and geolocation of messages. We subsequently characterize people's transition pattern motifs and demonstrate that spatial information is encoded in word choice.

  3. Aging response of coarse- and fine-grained {beta} titanium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ivasishin, O.M. [G.V.Kurdyumov Institute for Metal Physics, National Academy of Sciences, 03142 Kyiv (Ukraine)]. E-mail: ivas@imp.kiev.ua; Markovsky, P.E. [G.V.Kurdyumov Institute for Metal Physics, National Academy of Sciences, 03142 Kyiv (Ukraine); Semiatin, S.L. [Air Force Research Laboratory, AFRL/ML, Wright-Patterson Air Force Base, OH 45433-7817 (United States); Ward, C.H. [Air Force Research Laboratory, AFRL/ML, Wright-Patterson Air Force Base, OH 45433-7817 (United States)

    2005-09-25

    The effect of heating rate to aging temperature and {beta} grain size on the aging behavior of three metastable {beta} titanium alloys, TIMETAL-LCB, VT22 and Ti-15-3-3-3 ('Ti-15-3'), was established using in situ resistivity measurements, X-ray diffraction, optical microscopy, SEM, TEM and STEM characterization. The results revealed the alloys could be divided into two classes based on their aging behavior. TIMETAL-LCB and VT-22 formed fine plate-like {alpha} at slow heating rates to the aging temperature. This behavior was determined to be due to the precipitation of isothermal {omega} at low temperatures, which serves as nucleation sites for {alpha}. The slow heating rate yielded the best balance of strength and ductility, particularly in alloys with a fine ({approx}10 {mu}m) {beta} grain size. At high heating rates, the formation of isothermal {omega} was avoided, leading to coarse, plate-like {alpha} microstructures with less desirable properties. Ti-15-3, on the other hand, exhibited {beta} phase separation during isothermal aging rather than isothermal {omega} formation. Much slower cooling rates were required to form fine {alpha} laths in Ti-15-3 compared to the other two alloys. The importance of specifying heating rate and aging temperature for the industrial heat treatment of {beta} titanium alloys was thus established.

  4. A two-level real-time vision machine combining coarse and fine grained parallelism

    DEFF Research Database (Denmark)

    Jensen, Lars Baunegaard With; Kjær-Nielsen, Anders; Pauwels, Karl;

    2010-01-01

    In this paper, we describe a real-time vision machine having a stereo camera as input generating visual information on two different levels of abstraction. The system provides visual low-level and mid-level information in terms of dense stereo and optical flow, egomotion, indicating areas...... a factor 90 and a reduction of latency of a factor 26 compared to processing on a single CPU--core. Since the vision machine provides generic visual information it can be used in many contexts. Currently it is used in a driver assistance context as well as in two robotic applications....... with independently moving objects as well as a condensed geometric description of the scene. The system operates at more than 20 Hz using a hybrid architecture consisting of one dual--GPU card and one quad-core CPU. The different processing stages of visual information have rather different characteristics...

  5. Fine-grained facial phenotype–genotype analysis in Wolf–Hirschhorn syndrome

    OpenAIRE

    Hammond, Peter; Hannes, Femke; Suttie, Michael; Devriendt, Koen; Vermeesch, J.R.; Faravelli, Francesca; Forzano, Francesca; Parekh, Susan; Williams, Steve; McMullan, Dominic; South, Sarah T.; Carey, John; Quarrell, Oliver William

    2011-01-01

    Abstract Wolf-Hirschhorn syndrome (WHS) is caused by anomalies of the short arm of chromosome 4. About 55% of cases are due to de novo terminal deletions, 40% from unbalanced translocations and 5% from other abnormalities. The facial phenotype is characterized by hypertelorism, protruding eyes, prominent glabella, broad nasal bridge and short philtrum. We used dense surface modeling and pattern recognition techniques to delineate the milder facial phenotype of individuals with a sm...

  6. Fine-Grain Feature Extraction from Malware's Scan Behavior Based on Spectrum Analysis

    Science.gov (United States)

    Eto, Masashi; Sonoda, Kotaro; Inoue, Daisuke; Yoshioka, Katsunari; Nakao, Koji

    Network monitoring systems that detect and analyze malicious activities as well as respond against them, are becoming increasingly important. As malwares, such as worms, viruses, and bots, can inflict significant damages on both infrastructure and end user, technologies for identifying such propagating malwares are in great demand. In the large-scale darknet monitoring operation, we can see that malwares have various kinds of scan patterns that involves choosing destination IP addresses. Since many of those oscillations seemed to have a natural periodicity, as if they were signal waveforms, we considered to apply a spectrum analysis methodology so as to extract a feature of malware. With a focus on such scan patterns, this paper proposes a novel concept of malware feature extraction and a distinct analysis method named “SPectrum Analysis for Distinction and Extraction of malware features(SPADE)”. Through several evaluations using real scan traffic, we show that SPADE has the significant advantage of recognizing the similarities and dissimilarities between the same and different types of malwares.

  7. Flow-type failures in fine-grained soils: an important aspect in landslide hazard analysis

    Directory of Open Access Journals (Sweden)

    T. W. J. van Asch

    2009-10-01

    Full Text Available Forecasting the possibility of flow-type failures within a slow-moving landslide mass is rarely taken into account in quantitative hazard assessments. Therefore, this paper focuses on the potential transition of sliding blocks (slumps into flow-like processes due to the generation of excess pore water pressure in undrained conditions. The generation of excess pore water pressure may be the consequence of deformation of the landslide body during motion. Two model concepts are proposed and discussed. The first concept is the so called strain concept model where emphasis is laid on strain changes due to differential movement within the moving mass. This may create zones of compression and dilation and consequently excess pore water pressures. The second concept is the so called topographical concept model which focuses on changes in the stress field of the landslide caused by geometric changes in topography of the moving body. Both models were tested on two slumps which developed in secondary scarps of the Super-Sauze mudslide in the Barcelonnette Basin (South French Alps. The slump which developed in 1999 showed complete fluidization; all the material was removed from the source area and transformed into a mudflow. The second slump, dated from 2006, did not show fluidization; it has a relative short displacement and all the material remained in the source area. It appeared that the strain concept model predicted flow-type failure for both slumps, after relative short displacements, while the topographical concept model predicted only flow-type failure for the 1999 slump and not for the 2006 slump. The strain concept model seems too conservative in forecasting the fluidization potential of slumping blocks.

  8. A Geoacoustic Model for Fine-Grained, Unconsolidated Calcareous Sediments (ARSRP Natural Laboratory)

    Science.gov (United States)

    1994-03-09

    Bahama Bank 630 " 10 1. 632A 6 Exuma Sound 6 3 3 4 .. . 647A 105 15 Labrador Sea 657A 108 41 Equatorial Atlantic 657B 5 662A 12 663A 8 664B ൔ...I...development of chalk above 250 m. Rapid and extensive diagenesis is characteristic of carbonate 7 1 I sediments of the Bahama Banks area. Exuma sound

  9. Depositional Environment of Fine-Grained Sedimentary Rocks of the Sinamar Formation, Muara Bungo, Jambi

    Directory of Open Access Journals (Sweden)

    M. Heri Hermiyanto Zajuli

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i1.153The research area is situated in the northwestern side of South Sumatra Basin, which is a part of Muara Bungo Regency, Jambi Province. The Oligocene Sinamar Formation consists of shale, claystone, mudstone, sandstone, conglomeratic sandstone, and coal-seam intercalations. This research was focused on fine sedimentary rock of Sinamar Formation, such as shale, claystone, and mudstone. Primary data were collected from SNM boreholes which have depths varying from 75 m up to 200 m, and outcrops that were analyzed by organic petrographic method, gas chromatography-mass spectrometry (GC-MS of normal alkanes including isoprenoids, and sterane. The dominant maceral group is exinite, composed of alginite (3.4 - 18%, and resinite (1.6 - 5.6%, while vitrinite maceral consists of tellocolinite 0.4 - 0.6%, desmocollinite 0.4%, and vitrodetrinite 8.4 - 16.6%. Organic petrography and biomarker analyses show that organic materials of shales were derived from high plants and algae especially Botrycoccus species. Botrycoccus and fresh water fish fossil, found in the shale indicate a lacustrine environment.

  10. A Register Allocation Algorithm in the Presence of Scalar Replacement for Fine-Grain Configurable Architectures

    CERN Document Server

    Baradaran, Nastaran

    2011-01-01

    The aggressive application of scalar replacement to array references substantially reduces the number of memory operations at the expense of a possibly very large number of registers. In this paper we describe a register allocation algorithm that assigns registers to scalar replaced array references along the critical paths of a computation, in many cases exploiting the opportunity for concurrent memory accesses. Experimental results, for a set of image/signal processing code kernels, reveal that the proposed algorithm leads to a substantial reduction of the number of execution cycles for the corresponding hardware implementation on a contemporary Field-Programmable-Gate-Array (FPGA) when compared to other greedy allocation algorithms, in some cases, using even fewer number of registers.

  11. Characterizing bulk modulus of fine-grained subgrade soils under large capacity construction equipment

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2011-07-01

    Full Text Available 1 Corresponding Author. Senior Researcher, CSIR Built Environment, Transport Infrastructure Engineering, Bldg 2C, P O Box 395, Pretoria, 0001, South Africa; E-mail: JAnochieboateng@csir.co.za the optimum. The bulk modulus together with shear..., unloaded to zero, and then, reloaded to the next stress state until the maximum hydrostatic stress of 276 kPa was reached (i.e., 0 ? 20.7 kPa ? 0 ? 41.4 kPa ? 0 ? 69 kPa ? 0 ?138 kPa ? 0). A pulsed wave shape with 60-second loading and 60-second...

  12. Direct visualization of clay microfabric signatures driving organic matter preservation in fine-grained sediment

    Science.gov (United States)

    Curry, Kenneth J.; Bennett, Richard H.; Mayer, Lawrence M.; Curry, Ann; Abril, Maritza; Biesiot, Patricia M.; Hulbert, Matthew H.

    2007-04-01

    We employed direct visualization of organic matter (OM) sequestered by microfabric signatures in organo-clay systems to study mechanisms of OM protection. We studied polysaccharides, an abundant class of OM in marine sediments, associated with the nano- and microfabric of clay sediment using a novel application of transmission electron microscopy, histochemical staining (periodic acid-thiosemicarbazide-silver proteinate), and enzymatic digestion techniques. We used two experimental organo-clay sediment environments. First, laboratory-consolidated sediment with 10% chitin (w/w) added was probed for chitin before and after digestion with chitinase. Second, fecal pellets from the polychaete Heteromastus filiformis were used as a natural environment rich in clay and polysaccharides. Sections of this material were probed with silver proteinate for polysaccharides before and after digestion with a mixture of enzymes (amylase, cellulase, chitinase, dextranase, and pectinase). In both environments, chitin or other polysaccharides were found within pores, bridging clay domains, and attached to clay surfaces in undigested samples. Digested samples showed chitin or polysaccharides more closely associated with clay surfaces and in small pores. Our results imply protective roles for both sorption to clay surfaces and encapsulation within clay microfabric signatures.

  13. Structural stability of ultra-fine grained magnesium alloys processed by equal channel angular pressing

    Science.gov (United States)

    Janeček, M.; Krajňák, T.; Minárik, P.; Čížek, J.; Stráská, J.; Stráský, J.

    2017-05-01

    Structural stability of two magnesium alloys AZ31 (MgAlZn) and AX41 (MgAlCa) processed by equal channel angular pressing is investigated. The mechanical properties, microstructure evolution and dislocation density were studied by microhardness, electron back scatter diffraction and positron annihilation spectroscopy, respectively. The loss of microstructure stability at high temperatures and the coarsening of the ultrafine-grained structure as a result of isochronal annealing is accompanied by the sharp decrease of microhardness and the decrease of dislocation density. The differences in thermal stability of both alloys are related to different conditions of ECAP pressing and the phase stability, namely the presence of stable Al2Ca precipitates in AX41 alloy. Microscopic mechanisms controlling the structure stability of both alloys are discussed.

  14. Quicklime (CaO) Stabilization of fine-grained marine sediments in low temperature areas

    DEFF Research Database (Denmark)

    Skels, Peteris; Ingeman-Nielsen, Thomas; Jørgensen, Anders Stuhr;

    2011-01-01

    in a soil-CaO mixture was determined using a number of laboratory methods, such as pH test, consistency limit analysis, degree of compaction, and short term California Bearing Ratio (CBR) values. The study also numerically demonstrates a long term strength development of the soil-CaO mixture at 1°C and 10°C...... curing temperatures, comparing stabilization effectiveness between low and normal soil temperature conditions....

  15. Laboratory study on metal attenuation capacity of fine grained soil near ash pond site.

    Science.gov (United States)

    Ghosh, Sudipta; Mukherjee, Somnath; Sarkar, Sujoy; Kumar, Sunil

    2008-10-01

    Waste settling tanks of earthen containment nature are common in India for disposal of solid waste in slurry form. For a large pond system, e.g. ash slurry disposal tank of coal base thermal power plant, leachate generation and its migration pose a serious problem. A natural attenuation of controlling the migratory leachate is to use locally available clay material as lining system due to the adsorption properties of soil for reducing some metallic ions. The present investigation was carried out to explore the Ni2+ and Cr6+ removal capacity of surrounding soil of the ash pond site of Super Thermal Power Plant in West Bengal, India through some laboratory scale and field studies. The soil and water samples collected from the site showed the existence of Ni2+ and Cr6+ in excess to permissible limit. A two-dimensional adsorption behaviour of these pollutants through soil was assessed. The results showed that more than 80% of nickel and 72% of chromium were found to be sorbed by the soil corresponding to initial concentrations of two ions, i.e. 1.366 mg/L and 0.76 mg/L respectively. The batch adsorption data are tested Langmuir and Freundlich isotherm models and found reasonably fit. Breakthrough adsorption study uptake also showed a good adsorption capacity of the soil. The experimental results found to fit well with the existing two dimensional (2D) mathematical models as proposed by Fetter (1999).

  16. Depositional and Immersion-Mode Ice Nucleation of Fine-Grained Volcanic Ash Samples

    Science.gov (United States)

    Cloer, S.; Woods, T.; Genareau, K. D.

    2016-12-01

    Volcanic lightning is a common phenomenon during explosive eruptions; occurring as vent discharges, near-vent discharges, and plume lightning. Plume lightning is most similar to thunderstorm lightning, where volcanic ash may act as ice nuclei. Volcanic ash samples derived from eight volcanoes: Augustine, Crater Peak, Katmai, Okmok, Redoubt (Alaska, U.S.A.), Lathrop Well (Nevada, U.S.A.), Taupo (New Zealand), and Valles Caldera (New Mexico, U.S.A.); were used to determine what roles ash mineralogy, particularly Fe-oxide-bearing minerals and silica-enriched minerals, grain shape, and grain size have in the nucleation of ice, which can generate plume lightning. Depositional and immersion-mode ice nucleation experiments were performed using a Nicolet Almega XR Dispersive Raman spectrometer, following the methods of Schill et al. (2015), where samples were shaken for 24 h prior to experiments in ultra-pure water, then nebulized to super micron droplets. Depositional nucleation experiments were conducted from 225-235 K, and immersion-mode nucleation experiments were conducted from 233-278 K. A JEOL JSM 6010 Plus/LA scanning electron microscope (SEM), along with Image-J freeware, was used to quantify the number density of Fe-oxide mineral phases in backscattered electron images, with an x-ray diffractometer (XRD) used to determine bulk mineral abundance and an x-ray fluorescence (XRF) spectrometer to determine bulk ash composition. Based on previous studies, we hypothesize that all ash samples will efficiently form depositional ice nuclei; however, certain mineral phases will dictate the efficiency of immersion-mode ice nucleation including K or Na / Ca feldspars, which have been shown to be efficient nuclei, and Fe-oxide-bearing minerals. These results will shed new light on volcanic cloud dynamics and add new parameters for atmospheric models, which currently only address effects of mineral dust as ice nuclei and overlook the potential role of volcanic ash.

  17. Frontiers in Sedimentary Geology: Microstructure of Fine-Grained Sediments from Mud to Shale

    Science.gov (United States)

    1990-01-01

    Sediment in Response to Periodic D eposition ............................................... 417 Charles Libicki and Keith W Bedford 46 Elasticity of Fine...Division, Naval Ocean Research and Development Activity, Stennis Space Center, MS 39529-5004, USA CHARLES LIBICKI. Department of Civil Engineering, The...depositional waters" (Curtis, 1985, pp. 91-92). Diagencsi, of mineral phases and cementation operate over a Dunoyer De Segonzac (1970) pointed out that

  18. Fine-grained Delaunay triangulation in a simulation of tumor spheroid growth

    CERN Document Server

    Fabbro, A D; Milotti, E; Chignola, Roberto; Fabbro, Alessio Del; Milotti, Edoardo

    2006-01-01

    The simulation of many-particle systems often requires the detailed knowledge of proximity relations to reduce computational complexity and to provide a basis for specific calculations. Here we describe the basic scheme of a simulator of tumor spheroid growth: the calculation of mechanical interactions between cells and of the concentrations of diffusing chemicals requires a backbone provided by the Delaunay triangulation and the volumes of the associated Voronoi regions. Thus the Delaunay triangulation provides both the proximity relations needed to reduce the computational complexity and the basic structures that are needed to carry out the calculation of the biochemical interactions between cells and with the enviroment. A 3D version of the simulator uses the CGAL library as an essential component for the efficient computation of the Delaunay triangulation and of the Voronoi regions.

  19. Comparing Fine-Grained Source Code Changes And Code Churn For Bug Prediction

    NARCIS (Netherlands)

    Giger, E.; Pinzger, M.; Gall, H.C.

    2011-01-01

    A significant amount of research effort has been dedicated to learning prediction models that allow project managers to efficiently allocate resources to those parts of a software system that most likely are bug-prone and therefore critical. Prominent measures for building bug prediction models are

  20. Liberal Entity Extraction: Rapid Construction of Fine-Grained Entity Typing Systems.

    Science.gov (United States)

    Huang, Lifu; May, Jonathan; Pan, Xiaoman; Ji, Heng; Ren, Xiang; Han, Jiawei; Zhao, Lin; Hendler, James A

    2017-03-01

    The ability of automatically recognizing and typing entities in natural language without prior knowledge (e.g., predefined entity types) is a major challenge in processing such data. Most existing entity typing systems are limited to certain domains, genres, and languages. In this article, we propose a novel unsupervised entity-typing framework by combining symbolic and distributional semantics. We start from learning three types of representations for each entity mention: general semantic representation, specific context representation, and knowledge representation based on knowledge bases. Then we develop a novel joint hierarchical clustering and linking algorithm to type all mentions using these representations. This framework does not rely on any annotated data, predefined typing schema, or handcrafted features; therefore, it can be quickly adapted to a new domain, genre, and/or language. Experiments on genres (news and discussion forum) show comparable performance with state-of-the-art supervised typing systems trained from a large amount of labeled data. Results on various languages (English, Chinese, Japanese, Hausa, and Yoruba) and domains (general and biomedical) demonstrate the portability of our framework.

  1. Adaptive Inference of Fine-grained Data Provenance to Achieve High Accuracy at Lower Storage Costs

    NARCIS (Netherlands)

    Huq, M.R.; Wombacher, Andreas; Apers, Peter M.G.

    2011-01-01

    In stream data processing, data arrives continuously and is processed by decision making, process control and e-science applications. To control and monitor these applications, reproducibility of result is a vital requirement. However, it requires massive amount of storage space to store

  2. Fine-grained P2P traffc classifi cation by simply counting flows

    Institute of Scientific and Technical Information of China (English)

    Jie HE; Yue-xiang YANG; Yong QIAO; Wen-ping DENG

    2015-01-01

    The continuous emerging of peer-to-peer (P2P) applications enriches resource sharing by networks, but it also brings about many challenges to network management. Therefore, P2P applications monitoring, in particular, P2P traffic classifi cation, is becoming increasingly important. In this paper, we propose a novel approach for accurate P2P traffic classifi cation at a fi ne-grained level. Our approach relies only on counting some special fl ows that are appearing frequently and steadily in the traffic generated by specifi c P2P applications. In contrast to existing methods, the main contribution of our approach can be summarized as the following two aspects. Firstly, it can achieve a high classifi cation accuracy by exploiting only several generic properties of fl ows rather than complicated features and sophisticated techniques. Secondly, it can work well even if the classifi cation target is running with other high bandwidth-consuming applications, outperforming most existing host-based approaches, which are incapable of dealing with this situation. We evaluated the performance of our approach on a real-world trace. Experimental results show that P2P applications can be classifi ed with a true positive rate higher than 97.22%and a false positive rate lower than 2.78%.

  3. Analyzing the Evolution of Web Services using Fine-Grained Changes

    NARCIS (Netherlands)

    Romano, D.; Pinzger, M.

    2012-01-01

    Preprint of paper published in: ICWS 2012 - IEEE 19th International Conference on Web Services, 24-29 June 2012; doi:10.1109/ICWS.2012.29 In the service-oriented paradigm web service interfaces are considered contracts between web service subscribers and providers. However, these interfaces are co

  4. Construction and test of a fine-grained liquid argon preshower prototype

    CERN Document Server

    Davis, R; Pinfold, J L; Rodning, N L; Boos, E; Zhautykov, B O; Aubert, Bernard; Bazan, A; Beaugiraud, B; Boniface, J; Colas, Jacques; Eynard, G; Jézéquel, S; Le Flour, T; Linossier, O; Nicoleau, S; Rival, F; Sauvage, G; Thion, J; Van den Plas, D; Wingerter-Seez, I; Zitoun, R; Zolnierowski, Y; Chmeissani, M; Fernández, E; Garrido, L; Martínez, M; Padilla, C; Gordon, H A; Radeka, V; Rahm, David Charles; Stephani, D; Baisin, L; Berset, J C; Chevalley, J L; Gianotti, F; Gildemeister, O; Marin, C P; Nessi, Marzio; Poggioli, Luc; Richter, W; Vuillemin, V; Baze, J M; Gosset, L G; Lavocat, P; Lottin, J P; Mansoulié, B; Meyer, J P; Renardy, J F; Schwindling, J; Teiger, J; Collot, J; de Saintignon, P; Dzahini, D; Hostachy, J Y; Hoummada, A; Laborie, G; Mahout, G; Hervás, L; Chekhtman, A; Cousinou, M C; Dargent, P; Dinkespiler, B; Etienne, F; Fassnacht, P; Fouchez, D; Martin, L; Miotto, A; Monnier, E; Nagy, E; Olivetto, C; Tisserant, S; Battistoni, G; Camin, D V; Cavalli, D; Costa, G; Cozzi, L; Fedyakin, N N; Ferrari, A; Mandelli, L; Mazzanti, M; Perini, L; Resconi, S; Sala, P R; Beaudoin, G; Depommier, P; León-Florián, E; Leroy, C; Roy, P; Augé, E; Chase, Robert L; Chollet, J C; de La Taille, C; Fayard, Louis; Fournier, D; Hrisoho, A T; Merkel, B; Noppe, J M; Parrour, G; Pétroff, P; Schaffer, A C; Seguin-Moreau, N; Serin, L; Tisserand, V; Vichou, I; Canton, B; David, J; Genat, J F; Imbault, D; Le Dortz, O; Savoy-Navarro, Aurore; Schwemling, P; Eek, L O; Lund-Jensen, B; Söderqvist, J; Lefebvre, M; Robertson, S

    1997-01-01

    A separate liquid argon preshower detector consisting of two layers featuring a fine granularity of 2.5~10$^{\\mathrm{-3}}$ was studied by the RD3 collaboration. A prototype covering approximately 0.8 in pseudo-rapidity and 9 degrees in azimuth was built and tested at CERN in July 94. CMOS and GaAs VLSI preamplifiers were designed and tested for this occasion. The combined response of this detector and an accordion electromagnetic calorimeter prototype to muons, electrons and photons is presented. For minimum ionizing tracks a signal-to-noise ratio of 4.5 per preshower layer was measured. Above 150~GeV the space resolution for electrons is better than 250~$\\mu$m in both directions. The precision on the electromagnetic shower direction, determined together with the calorimeter, is better than 4 mrad above 50~GeV. It is concluded that the preshower detector would adequately fulfil its role for future operation at CERN Large Hadron Collider.

  5. Deformation mechanisms in fine grained quartzo-feldspathic mylonites : an electron microscopy study

    NARCIS (Netherlands)

    Fliervoet, Timon F.

    1995-01-01

    Previous work on the deformation mechanisms in quartzo-feldspathic rocks from the upperand middle-crust has predominantly concentrated on single phase quartz bands within these rocks. This has served well as a first approach, but several shortcomings have become evident concerning the highest strain

  6. Low magnification EBSD mapping of texture distribution in a fine-grained matrix

    Science.gov (United States)

    Gardner, Joseph; Mariani, Elisabetta; Wheeler, John

    2016-04-01

    The study of texture (CPO) in rocks is often restricted to individual phases within a given sample or specific area of said sample. Large scale EBSD mapping of the matrix of a greenschist facies albite mylonite has shown that an overall significant CPO within albite grains is strongly domainal, and each domain has a unique CPO that is independent of both common slip systems in plagioclase and the specimen geometry (i.e. foliation and lineation). Observational evidence suggests the metamorphic breakdown of plagioclase to albite (Ab) plus a Ca-bearing phase (clinozoisite, Cz) has produced a two phase mixture in which each phase has a contrasting solubility. New grains of albite are thought to nucleate epitaxially from original plagioclase as a reaction front passes through parent grains. A pseudomorphic region of Ab plus Cz after an original plagioclase crystal, protected from intense deformation by enclosure in a cm-scale augite clast, gives insight into pre-deformation daughter grain distributions. The albite in the region inherits a strong CPO and 180° misorientation peak from a relict twin pattern due to epitaxial growth while clinozoisite is randomly distributed and oriented (despite some grains nucleating from the plagioclase parent twin boundary). In the deformed matrix, daughter Ab is seen to be the more mobile phase, having undergone obvious dissolution, transport and reprecipitation into fractures and pressure shadows, whereas Cz grains are relatively insoluble and rotate into parallelism with the foliation, forming bands that anastamose around Cpx porphyroclasts. Despite this modification, albite in the matrix retains significant CPOs that comprise distinct domains with sharp boundaries. A 180° misorientation peak thought to be a signature of twinning inherited from parent plagioclase is also observed in each domain. Why a CPO should be preserved under these conditions (contrary to our traditional understanding that CPOs are a signature of dislocation creep and diffusional processes weaken or destroy any existing CPO) is the context of wider study. The extent and form of the CPO domains can be clearly and simply resolved by thin section scale mapping. Interestingly, although each domain inherits a unique CPO from its parent (i.e. adjacent domains do not share similar CPOs), all domains have been modified to lie broadly parallel to the sample foliation plane. Additionally, distribution of Cz, which is heterogeneous throughout the matrix, appears to correlate with specific CPO domains, and may exert an influence on domain boundaries. Information such as this about the larger-scale relationships between phase distribution and texture development and/or preservation cannot easily be resolved in smaller fields of view. Datasets like those presented are becoming increasingly easy to collect due to advances in EBSD data acquisition speed and indexing quality, and can add useful insight into how phases may have interacted during deformation.

  7. Privacy Protection in Participatory Sensing Applications Requiring Fine-Grained Locations

    DEFF Research Database (Denmark)

    Dong, Kai; Gu, Tao; Tao, Xianping

    2010-01-01

    The emerging participatory sensing applications have brought a privacy risk where users expose their location information. Most of the existing solutions preserve location privacy by generalizing a precise user location to a coarse-grained location, and hence they cannot be applied in those...... provider is an trustworthy entity, making our solution more feasible to practical applications. We present and analyze our security model, and evaluate the performance and scalability of our system....

  8. Evaluation of Underdrainage Techniques for the Densification of Fine-Grained Dredged Material.

    Science.gov (United States)

    1981-03-01

    i.e., collector pipe size and spacing and drain thickness) can be made without difficulty ( Cedergren 1977, and Department of the Army, Office, Chief...accomplished. 93 REFERENCES Cedergren , H. R. 1977. Seepage, Drainaj, and Flow Nets, 2nd Edit ion, Wiley, New York, N. Y. Department of the Army, Office

  9. Fine-Grained Sediments; an Annotated Bibliography on Their Dynamic Behavior in Aquatic Systems.

    Science.gov (United States)

    1987-09-01

    mouth of the River Chao Phraya with the object . of developing methods of improving the approaches to the Port of Bangkok...j .- Considerable...long estuarine stretch of the Chao Phya and the adjacent 20- by 40-sq km part of the Gulf of Thailand in which the river has deposited vast mud flats...Hydraulic shear strength Field studies Boat waves Tidal rivers Estuaries Tidal flows Currents Velocities Mixing Shelf waves Sediment concentration

  10. Influence Of Fine-Grained Montmorillonite On Microfungal Pellets Growth In Aqueous Suspensions

    Directory of Open Access Journals (Sweden)

    Jesenák Karol

    2015-06-01

    Full Text Available The paper presents an inhibition effect of clay mineral – montmorillonite – on the growth of microscopic filamentous fungus Aspergillus niger in the aqueous solution. The significant reduction in growth of the final size of spherical fungal pellets as well as total amount of produced microbial biomass was found out. Within the observed range of additions of clay mineral of 1, 5, 10, 15 and 20 g in the total volume of the 80 ml suspension, this size was in indirect relation to the weight of montmorillonite. However, the most significant inhibition effect was observed at the lowest concentration of the sorbent (1 g. Microscopic analysis of pellets referred to the presence of mineral particles in their pore structure and the distribution of particles in the spatial structure of fungal hyphae was variable. The experiment clearly demonstrated an inhibition effect of montmorillonite. This inhibition could be answered by the experiments focused on the detection of the influence of size and shape of inorganic sorption particles together with the influence of the physicochemical properties of its surface. It could be stated that the simultaneous application of the microscopic fungus Aspergillus niger and the clay mineral montmorillonite for decontamination of waste waters should be disadvantage due to their interaction if compared with the decontamination based on bioaccumulation and sorption separately.

  11. A Raspberry Pi Cluster Instrumented for Fine-Grained Power Measurement

    Directory of Open Access Journals (Sweden)

    Michael F. Cloutier

    2016-09-01

    Full Text Available Power consumption has become an increasingly important metric when building large supercomputing clusters. One way to reduce power usage in large clusters is to use low-power embedded processors rather than the more typical high-end server CPUs (central processing units. We investigate various power-related metrics for seventeen different embedded ARM development boards in order to judge the appropriateness of using them in a computing cluster. We then build a custom cluster out of Raspberry Pi boards, which is specially designed for per-node detailed power measurement. In addition to serving as an embedded cluster testbed, our cluster’s power measurement, visualization and thermal features make it an excellent low-cost platform for education and experimentation.

  12. Ultrasound backscatter microscope using PZT, fine-grain PZT, and single-crystal perovskite transducers

    Science.gov (United States)

    Olbrish, Kenneth D.; Zipparo, Michael J.; Lopath, Patrick D.; Yu, Clarence; Shrout, Thomas R.; Shung, K. Kirk

    1997-04-01

    Higher frequency ultrasound is rapidly becoming an important tool for dermatologic and ophthalmologic imaging. This brings about a need for improvement in single element transducers operating in the frequency range between 40 MHz and 100 MHz. Several piezoelectric materials may yield improved performance over common lead zirconate titanate (PZT) transducers. This study investigated several different materials incorporated into single element transducers. A static ultrasonic backscatter microscope (UBM) was constructed in the laboratory. This system allowed for a comparative testing of the imaging performance of various transducers. B-mode scans made by individual transducers show differences in image resolution. Clinically, these differences may be important to allow finer detail to be observed in a structure. Not only does this work show differences between transducers constructed from various materials, but it does so in an application-based environment. Previously, only a limited number of materials were used in such a system. This study showed results from several materials that had not been demonstrated before.

  13. Enhanced mechanical properties by grain boundary strengthening in ultra-fine grained TZP ceramics

    NARCIS (Netherlands)

    He, Y.J.; Winnubst, A.J.A.; Sagel-Ransijn, C.D.; Burggraaf, A.J.; Verweij, H.

    1996-01-01

    The mechanical properties of ceramics with the compositions of 5 mol% YO1.5-TZP (ZY5) and 4 mol% YO1.5-4 mol% CeO2-TZP (ZY4Ce4) were investigated. Nanocrystalline powders of both TZPs were synthesized by a gel precipitation technique. Powder compacts were made by cold isostatic pressing, and were th

  14. The fine-grained metaphysics of artifactual and biological functional kinds

    NARCIS (Netherlands)

    Carrara, M.; Vermaas, P.E.

    2008-01-01

    In this paper we consider the emerging position in metaphysics that artifact functions characterize real kinds of artifacts. We analyze how it can circumvent an objection by David Wiggins (Sameness and substance renewed, 2001, 87) and then argue that this position, in comparison to expert judgments,

  15. Biological recultivation with the use of fine-grained carbon waste

    Energy Technology Data Exchange (ETDEWEB)

    Kuczynska, I.; Haber, Z. (University of Mining and Metallurgy, Cracow (Poland). Institute of Mineral Processing and Natural Resources Utilization)

    1993-01-01

    Studies use of black coal mining waste (50% ash content, 2% sulfur content) for recultivation of a municipal landfill. The coal mining waste was decarbonized and desulfurized in a hydrocyclone, yielding a waste fraction with 70% ash content and 0.7% sulfur. This waste fraction was applied as a 25-30 cm thick cover over a municipal landfill site containing rubble, plastics, glass, wood, paper, etc. A peat and fertilizer mixture was added. This cover was 15 cm deep after natural compaction. Some 130 trees of different species, 100 bushes and different grass types were planted; plant growth was monitored for 3 years. No further cultivation of the plants was provided in that period, during which a serious drought and frosts occurred. Very good growth of the plants Populus alba, Robinia pseudoacacia, Malus purpurea, Ailanthus altissima, Eleagnus angustifolia, Ligustrum vulgare and the grass types Elymus arenaria and Phalaris arundinacea was observed. 1 ref.

  16. WYSIWIB: Exploiting Fine-Grained Program Structure in a Scriptable API-Usage Protocol Finding Process

    DEFF Research Database (Denmark)

    Lawall, Julia; Brunel, Julien Pierre Manuel; Palix, Nicolas Jean-Michel

    2013-01-01

    functions, which we refer to as API protocols. Our approach builds on the Coccinelle program matching and transformation tool, which allows a user to construct patterns that reflect the structure of the code to be matched. We evaluate our approach on the source code of the Linux kernel, which defines a very...... large number of API functions with varying properties. Linux is also critical software, implying that fixing even bugs involving rarely used protocols is essential. In our experiments, we use our approach to find over 3000 potential API protocols, with an estimated false positive rate of under 15...

  17. Fine-Grained Linguistic Soft Constraints on Statistical Natural Language Processing Models

    Science.gov (United States)

    2009-01-01

    monolingual paraphrases for the unigram baile improve when using the larger corpus, (e.g., danza and un balie become the third and fourth top candidates...paraphrases of deal are semantically close to it (agreement, 127 pivot wmt09+acquis wmt09+acquis+afp Source: baile danza el baile el baile bailar baile y...baile y a de david palomar y la danza dans viejo como quien se acomoda una un baile empresa por julián estrada el tercero de teatro coro al baile a

  18. A fine-grained analysis of the jumping-to-conclusions bias in schizophrenia

    Directory of Open Access Journals (Sweden)

    Steffen Moritz

    2009-12-01

    Full Text Available Impaired decision behavior has been repeatedly observed in schizophrenia patients. We investigated several cognitive mechanisms that might contribute to the jumping-to-conclusions bias (JTC seen in schizophrenia patients: biases in information-gathering, information weighting and integration, and overconfidence, using the process tracing paradigm Mouselab. Mouselab allows for an in-depth exploration of various decision-making processes in a structured information environment. A total of 37 schizophrenia patients and 30 healthy controls participated in the experiment. Although showing less focused and systematic information search, schizophrenia patients practically considered all pieces of information and showed no JTC in the sense of collecting less pieces of evidence. Choices of patients and controls both approximated a rational solution quite well, but patients showed more extreme confidence ratings. Both groups mainly used weighted additive decision strategies for information integration and only a small proportion relied on simple heuristics. Under high stress induced by affective valence plus time pressure, however, schizophrenia patients switched to equal weighting strategies: less valid cues and more valid ones were weighted equally.

  19. An evaluation on fatigue crack growth in a fine-grained isotropic graphite

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hongtao; Sun Libin [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Li Chenfeng [College of Engineering, Swansea University, Singleton Park, Swansea SA2 8PP (United Kingdom); Shi Li [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Wang Haitao, E-mail: wanght@tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer The propagation of micro- and macro-fatigue cracks in IG-11 graphite was studied. Black-Right-Pointing-Pointer The curves of the fatigue crack growth rate versus the SIF range show three stages. Black-Right-Pointing-Pointer The fatigue microcrack propagation is very sensitive to graphite's microstructures. Black-Right-Pointing-Pointer Graphite's microstructures have no significant impact on fatigue macrocrack growth. Black-Right-Pointing-Pointer The fatigue fracture surface indicates the fracture mechanism of the IG-11 graphite. - Abstract: The aim of this paper is to investigate the mechanism of fatigue crack propagation in IG-11 graphite, and determine the crack growth rate in relation to the stress level. Experimental studies were performed at both micro and macro scales. For fatigue microcrack propagation, single-edge-notch specimens were chosen for testing and the fatigue crack growth was measured in situ with a scanning electron microscope. For fatigue macrocrack propagation, CT specimens were used and the fatigue crack growth was measured with a high-accuracy optic microscope. Combining the two groups of experimental results, the following conclusions are derived: (1) The heterogeneous microstructures of the graphite material have significant impact on the fatigue microcrack growth, while their influence on fatigue macrocrack growth is very limited. (2) The relationship between the fatigue crack growth rate and the crack-tip stress intensity factor range can be expressed in the form of Paris formulae, which contains three stages: an initial rising part with a small slope, an abrupt rise with a very large acceleration, and a short final part with a small slope. (3) The fatigue fracture surface of the graphite material contains considerable sliding of leaf-shape graphite flakes combined with small cotton-shape plastic deformations. These sliding traces are approximately aligned at 45 Degree-Sign , showing the main cause of the fatigue fracture is the shear stress. There are also a large amount of secondary cracks inside unit cells and on cell walls, which indicates the fracture mechanism of the IG-11 graphite is mainly cleavage fracture.

  20. Fine-Grained Access Control Within NoSQL Document-Oriented Datastores

    National Research Council Canada - National Science Library

    Colombo, Pietro; Ferrari, Elena

    2016-01-01

    The recent years have seen the birth of several NoSQL datastores, which are getting more and more popularity for their ability to handle high volumes of heterogeneous and unstructured data in a very efficient way...

  1. Grain growth and experimental deformation of fine-grained ice aggregates

    Science.gov (United States)

    Diebold, Sabrina; de Bresser, Hans; Spiers, Chris; Durham, William B.; Stern, Laura

    2010-05-01

    Ice is one of the most abundant materials in our solar system. It is the principal constituent of most of the moons of the outer solar system. Thus, the flow behavior of ice is of great interest when studying geodynamic processes on icy moons. Grain growth is an elementary process that is assumed to be important in the ice sheet layering of planetary moons, where temperatures 100-273 K exist. We concentrate on the questions to what extent grain growth may influence the evolution of strength of deforming ice and if the grain growth process is independent or dependent of deformation. The answers to these questions will help us to quantitatively test the hypothesis that the progressive evolution of the grain (crystal) size distribution of deforming and recrystallizing ice directly affects its rheological behaviour in terms of composite grain-size-sensitive (GSS) and grain-size-insensitive (GSI) creep, and that this might, after time, result in a steady state balance between mechanisms of GSS and GSI creep. We performed static grain growth experiments at different temperatures and a pressure (P) of 1 atm, and deformation experiments at P = 30-100 MPa starting in the GSS-creep field. The starting material ice Ih has a grain size growth tests a Hart Scientific temperature bath was filled with d-Limonene as cooling medium. The ice specimens were put into sealed alumina cylinders. For the grain growth tests, temperatures (T) between 213 K and 268 K were chosen. The durations of these tests varied between one day and two weeks. For the deformation experiments, temperatures of > 170 K and strain rates between 10-8 s-1 and 10-4 s-1 were chosen. Grain sizes, grain size distributions and grain topologies were measured by cryogenic SEM and image analysis techniques. We found clear evidence of grain growth and a significantly T-dependent variation of grain size distributions. The observations allow us to calibrate values for the grain size exponent n and the activation energy Q as used in conventional grain growth laws. We simulated grain growth of ice based on the microphysical model of Kellermann Slotemaker (2006). This model takes into account full grain size distributions and allows grain boundary migration driven by different acting forces. We will show the importance of these driving forces for grain growth and deformation in polycrystalline ice aggregates. References Kellermann Slotemaker, A., 2006. Dynamic recrystallization and grain growth in olivine rocks. PhD Thesis, Utrecht University, Utrecht, 187 pp. Stern, L., 1997. Grain-size-inducedweakening of H2O ices I and II and associated anisotropic recrystallization. Journal of Geophysical Research, 102 (B3): 5313-5325.

  2. Plastic Properties of Fine-Grained WMD After Micro-Jet Cooling

    Directory of Open Access Journals (Sweden)

    Hadryś D.

    2014-10-01

    Full Text Available Micro-jet welding is an innovative method of weld forced cooling immediately after welding. It allows to obtain weld with superior properties in comparison to conventional welding. The reason for this is to obtain a more favorable structure of the weld metal deposit (WMD with much higher amount of acicular ferrite (AF. Different structures and mechanical properties of weld metal deposit were obtained by using various gases for cooling. The paper shows the relationship between the type of gas for micro-jet cooling and plastic properties of the weld joint. Coefficient of restitution and plastic strain were selected to describe changes of weld plastic properties for different micro-jet cooling gases. The tests were performed in dynamic conditions (impact.

  3. 分散聚合法合成含有环氧基的无孔超顺磁性微球及其表征%Preparation and Characterization of Non-porous Superparamagnetic Microspheres with Epoxy Groups by Dispersion Polymerization

    Institute of Scientific and Technical Information of China (English)

    马志亚; 官月平; 刘先桥; 刘会洲

    2005-01-01

    Non-porous superparamagnetic polymer microspheres with epoxy groups were prepared by dispersion polymerization of glycidyl methacrylate (GMA) in the presence of magnetic iron oxide (Fe3 O4) nanoparticles coated with oleic acid. The polymerization was carried out in the ethanol/water medium using polyvinylpyrrolidone (PVP)and 2,2'-azobisisobutyronitrile (AIBN) as stabilizer and initiator, respectively. The magnetic microspheres obtained were characterized with scanning electron microscopy (SEM), vibrating sample magnetometry (VSM) and Fourier transform infrared spectroscopy (FTIR). The results showed that the magnetic microspheres had an average size of have extensive potential uses in magnetic bioseparation and biotechnology.

  4. Meta-analyzing ownership concentration and firm performance in Asia: Towards a more fine-grained understanding

    NARCIS (Netherlands)

    P.P.M.A.R. Heugens (Pursey); M. van Essen (Marc); J. van Oosterhout (Hans)

    2009-01-01

    textabstractWe present a meta-analysis of the relationship between concentrated ownership and firm financial performance in Asia. At the cross-national level of analysis, we find a small but significant positive association between both variables. This finding suggests that in regions with less than

  5. Fine-grained temporal coding of visually-similar categories in the ventral visual pathway and prefrontal cortex

    Directory of Open Access Journals (Sweden)

    Yang eXu

    2013-10-01

    Full Text Available Humans are remarkably proficient at categorizing visually-similar objects. To better understand the cortical basis of this categorization process, we used magnetoencephalography (MEG to record neural activity while participants learned--with feedback--to discriminate two highly-similar, novel visual categories. We hypothesized that although prefrontal regions would mediate early category learning, this role would diminish with increasing category familiarity and that regions within the ventral visual pathway would come to play a more prominent role in encoding category-relevant information as learning progressed. Early in learning we observed some degree of categorical discriminability and predictability in both the prefrontal cortex and the ventral visual pathway. Predictability improved significantly above chance in the ventral visual pathway over the course of learning with the left inferiortemporal and fusiform gyri showing the greatest improvement in predictability between 150-250msec (M200 during category learning. In contrast, there was no comparable increase in discriminability in prefrontal cortex with the only significant post-learning effect being a decrease in predictability in inferior frontal gyrus between 250-350msec (M300. Thus, the ventral visual pathway appears to encode learned visual categories over the long term. At the same time these results add to our understanding of the cortical origins of previously-reported signature temporal components associated with perceptual learning.

  6. Determination of physico-chemical properties of fine-grained waste from the cleaning of iron casting

    Directory of Open Access Journals (Sweden)

    T. Lis

    2017-01-01

    Full Text Available In the European Union one of the most important activities is the recovery and recycling of waste including foundry waste. In the article waste arising from production of iron casting was presented. Selected physic-chemical properties of iron-bearing waste were defined. Opportunities of waste management are related to their chemical construction as well as some physical properties. On the basic the results of research the solutions of foundry waste management were proposed.

  7. High-temperature plastic deformation of fine-grained Y-doped BaCeO{sub 3} polycrystals

    Energy Technology Data Exchange (ETDEWEB)

    Vaquero-Aguilar, C; Jimenez-Melendo, M [Departamento de Fisica de la Materia Condensada, Universidad de Sevilla. Aptdo. 1065. 41080 Sevilla (Spain); Real, C, E-mail: melendo@us.e [Instituto de Ciencia de Materiales de Sevilla, Centro Mixto CSIC-US, Av. Americo Vespucio 49. 41092 Sevilla (Spain)

    2010-07-01

    The high-temperature plastic deformation of BaCe{sub 0.95}Y{sub 0.05}O{sub 3-{delta}} polycrystals with average grain size of 0.50 {mu}m has been studied in compression between 1000 and 1250{sup 0}C in air at different initial strain rates. The stress-strain curves display yield drop at strains close to 5%, followed by steady state or strain-softening stages. Large ductilities were achieved at the higher temperatures, without appreciable changes in grain shape and size. Mechanical data and microstructural observations are consistent with a flow mechanism by grain boundary sliding.

  8. Measurement and modelling of moisture-electrical resistivity relationship of fine-grained unsaturated soils and electrical anisotropy

    Science.gov (United States)

    Merritt, A. J.; Chambers, J. E.; Wilkinson, P. B.; West, L. J.; Murphy, W.; Gunn, D.; Uhlemann, S.

    2016-01-01

    A methodology for developing resistivity-moisture content relationships of materials associated with a clayey landslide is presented. Key elements of the methodology include sample selection and preparation, laboratory measurement of resistivity with changing moisture content, and the derivation of models describing the relationship between resistivity and moisture content. Laboratory resistivity measurements show that the techniques utilised (samples and square array) have considerable potential as a means of electropetrophysical calibration of engineering soils and weak rock. Experimental electrical resistivity results show a hierarchy of values dependent on sample lithology, with silty clay exhibiting the lowest resistivities, followed by siltstones and sands, which return the highest resistivities. In addition, finer grained samples show a greater degree of anisotropy between measurement orientations than coarser grained samples. However, suitability of results in light of issues such as sample cracking and electrical conduction must be identified and accounted for if the results are to be accurately up-scaled to inverted model resistivity results. The existence of directional anisotropy makes model calibration curve selection more difficult due to variability in the range of measured laboratory resistances. The use of larger measurement array size means that experimental data will be more representative of bulk lithological properties. In addition, use of electrodes with a relatively high surface area (wide diameter) help maintain low contact resistances and repeat measurement error, relative to narrow electrodes. Variation exists between the fit of experimental data and petrophysical models. Model fit is best for clay-dominated samples but fits less well for sand-dominated samples. Waxman-Smits equation is appropriately applied in this investigation as all samples have considerable clay mineral content, as is shown in non-negligible CEC results. The incorporation of pressure plate suction measurements on samples, allows suction dissipation to be quantified and evaluated alongside moisture content and electrical resistivity.

  9. Centrifuge modelling of an instrumented free-fall sphere for measurement of undrained strength in fine-grained soils

    National Research Council Canada - National Science Library

    O’Loughlin, C.D; Morton, J.P; White, D.J

    .... This allowed the penetration resistance acting on the sphere to be expressed in terms of a single capacity factor that captures soil resistance from both shearing and drag, and varies uniquely...

  10. Student Modeling in Orthopedic Surgery Training: Exploiting Symbiosis between Temporal Bayesian Networks and Fine-Grained Didactic Analysis

    Science.gov (United States)

    Chieu, Vu Minh; Luengo, Vanda; Vadcard, Lucile; Tonetti, Jerome

    2010-01-01

    Cognitive approaches have been used for student modeling in intelligent tutoring systems (ITSs). Many of those systems have tackled fundamental subjects such as mathematics, physics, and computer programming. The change of the student's cognitive behavior over time, however, has not been considered and modeled systematically. Furthermore, the…

  11. A Real-Time Early Cognitive Vision System based on a Hybrid coarse and fine grained Parallel Architecture

    DEFF Research Database (Denmark)

    Jensen, Lars Baunegaard With

    .The ECV stage has been introduced as a means to bridge the gap between Early Vision (EV) and Cognitive Vision (CV) processes. Where the EV stage deals with analyzing the images through linear and nonlinear local filtering operations on a pixel level, CV deals with higher cognitive processes...

  12. Processes Controlling Transfer of Fine-Grained Sediment in Tidal Systems Spanning a Range of Fluvial Influence

    Science.gov (United States)

    2012-09-30

    in Tidal Systems Spanning a Range of Fluvial Influence Andrea S. Ogston School of Oceanography Box 357940 Seattle, WA 98195 phone: (206) 543...other seasonal (winds/waves, precipitation temperature, and biological) processes influence the transport pathways, seabed erosion /deposition, and...degrees of fluvial , wave, and tidal influence in each environment. At present, we are completing our studies on unvegetated tidal flats, and are ramping

  13. A method to implement fine-grained access control for personal health records through standard relational database queries.

    Science.gov (United States)

    Sujansky, Walter V; Faus, Sam A; Stone, Ethan; Brennan, Patricia Flatley

    2010-10-01

    Online personal health records (PHRs) enable patients to access, manage, and share certain of their own health information electronically. This capability creates the need for precise access-controls mechanisms that restrict the sharing of data to that intended by the patient. The authors describe the design and implementation of an access-control mechanism for PHR repositories that is modeled on the eXtensible Access Control Markup Language (XACML) standard, but intended to reduce the cognitive and computational complexity of XACML. The authors implemented the mechanism entirely in a relational database system using ANSI-standard SQL statements. Based on a set of access-control rules encoded as relational table rows, the mechanism determines via a single SQL query whether a user who accesses patient data from a specific application is authorized to perform a requested operation on a specified data object. Testing of this query on a moderately large database has demonstrated execution times consistently below 100ms. The authors include the details of the implementation, including algorithms, examples, and a test database as Supplementary materials.

  14. A model for coupled electro-hydro-mechanical processes in fine grained soils accounting for gas generation and transport

    Energy Technology Data Exchange (ETDEWEB)

    Tamagnini, Claudio; Cattaneo, Fabio [Universita degli Studi di Perugia (Italy). Dept. of Civil and Environmental Engineering; Jommi, Cristina [Politecnico di Milano (Italy). Dept. of Structural Engineering

    2010-07-01

    A theoretical and numerical model is developed for the quantitative analysis of coupled processes taking place in active waste containment systems, such as electrokinetic barriers or fences, in which a low intensity D C current is circulated across the clay barrier to move polar and non-polar contaminants. A novel feature of the proposed approach is the allowance for the presence of air in the pore space. Under unsaturated conditions, all transport coefficients involved in the electrokinetic process are strongly dependent on the degree of saturation of pore liquid. In order to assess the predictive capability of the proposed theory and to appreciate the impact of gas production at the electrodes, a series of numerical simulations of simple one dimensional electrokinetic tests have been performed. The results of the simulations compare reasonably well with data obtained from laboratory experiments performed on an illitic clayey silt. The numerical results indicate that the impact of gas production at the electrodes can be significant, even in low-intensity and short-duration treatments. (author)

  15. Student Modeling in Orthopedic Surgery Training: Exploiting Symbiosis between Temporal Bayesian Networks and Fine-Grained Didactic Analysis

    Science.gov (United States)

    Chieu, Vu Minh; Luengo, Vanda; Vadcard, Lucile; Tonetti, Jerome

    2010-01-01

    Cognitive approaches have been used for student modeling in intelligent tutoring systems (ITSs). Many of those systems have tackled fundamental subjects such as mathematics, physics, and computer programming. The change of the student's cognitive behavior over time, however, has not been considered and modeled systematically. Furthermore, the…

  16. Determination of physico-chemical properties of fine-grained waste from the cleaning of iron casting

    OpenAIRE

    2017-01-01

    In the European Union one of the most important activities is the recovery and recycling of waste including foundry waste. In the article waste arising from production of iron casting was presented. Selected physic-chemical properties of iron-bearing waste were defined. Opportunities of waste management are related to their chemical construction as well as some physical properties. On the basic the results of research the solutions of foundry waste management were proposed.

  17. Progradation and erosion of a fine-grained tidally dominated delta: A case study of the Jiangsu coast, China

    NARCIS (Netherlands)

    Su, M.

    2016-01-01

    A large proportion of the world population lives in the coastal zone, which is facing a variety of natural and anthropogenic impacts on its evolution. A better understanding of coastal evolution can be obtained when it is based on an accurate knowledge of coastal dynamics. This thesis aims to study

  18. Use of fine-grained shredder dust as a cement admixture after a melting, rapid-cooling and pulverizing process

    Energy Technology Data Exchange (ETDEWEB)

    Kakimoto, K. [Kyushu Institute of Technology, Fukuoka (Japan). Department of Applied Chemistry; Nakano, Y. [Kyushu Institute of Technology, Fukuoka (Japan). Graduate School, Department of Engineering; Yamasaki, T.; Shimuzu, K.; Idemitsu, T. [Kyushu Institute of Technology, Fukyoka (Japan). Department of Civil Engineering

    2004-12-01

    Shredder dust is a residue, which is removed from valuable ferrous metals found in scrap automobile and electronic waste. It is also an industrial waste byproduct which, under legislation in place since April 1996, must be disposed of in landfill sites. One method of disposing shredder dust is by scorification, however, this is a costly process and therefore impractical. Costs could be reduced if the shredder dust had a valuable use, and, in this paper, the authors examine its effectiveness as a cement admixture. First, molten shredder dust was crushed for use as a cement admixture. However, it was difficult to crush it completely because metallic grains were mixed in with molten shredder dust. These particles were removed by sifting and the molten shredder dust was crushed once again. Eventually, a fine 75 {mu}m and less powder type of slag was obtained. This slag was mixed with Ordinary Portland Cement (OPC) to form a cement mortar and subsequently a mortar test was conducted. From the test results, it was found that the long-term strength of the cement did not deteriorate even when it included 30% by weight of the pulverized molten shredder dust. (author)

  19. Determining the sources of fine-grained sediment using the Sediment Source Assessment Tool (Sed_SAT)

    Science.gov (United States)

    Gorman Sanisaca, Lillian E.; Gellis, Allen C.; Lorenz, David L.

    2017-07-27

    A sound understanding of sources contributing to instream sediment flux in a watershed is important when developing total maximum daily load (TMDL) management strategies designed to reduce suspended sediment in streams. Sediment fingerprinting and sediment budget approaches are two techniques that, when used jointly, can qualify and quantify the major sources of sediment in a given watershed. The sediment fingerprinting approach uses trace element concentrations from samples in known potential source areas to determine a clear signature of each potential source. A mixing model is then used to determine the relative source contribution to the target suspended sediment samples.The computational steps required to apportion sediment for each target sample are quite involved and time intensive, a problem the Sediment Source Assessment Tool (Sed_SAT) addresses. Sed_SAT is a user-friendly statistical model that guides the user through the necessary steps in order to quantify the relative contributions of sediment sources in a given watershed. The model is written using the statistical software R (R Core Team, 2016b) and utilizes Microsoft Access® as a user interface but requires no prior knowledge of R or Microsoft Access® to successfully run the model successfully. Sed_SAT identifies outliers, corrects for differences in size and organic content in the source samples relative to the target samples, evaluates the conservative behavior of tracers used in fingerprinting by applying a “Bracket Test,” identifies tracers with the highest discriminatory power, and provides robust error analysis through a Monte Carlo simulation following the mixing model. Quantifying sediment source contributions using the sediment fingerprinting approach provides local, State, and Federal land management agencies with important information needed to implement effective strategies to reduce sediment. Sed_SAT is designed to assist these agencies in applying the sediment fingerprinting approach to quantify sediment sources in the sediment TMDL framework.

  20. Mind wandering and attention during focused meditation: a fine-grained temporal analysis of fluctuating cognitive states.

    Science.gov (United States)

    Hasenkamp, Wendy; Wilson-Mendenhall, Christine D; Duncan, Erica; Barsalou, Lawrence W

    2012-01-02

    Studies have suggested that the default mode network is active during mind wandering, which is often experienced intermittently during sustained attention tasks. Conversely, an anticorrelated task-positive network is thought to subserve various forms of attentional processing. Understanding how these two systems work together is central for understanding many forms of optimal and sub-optimal task performance. Here we present a basic model of naturalistic cognitive fluctuations between mind wandering and attentional states derived from the practice of focused attention meditation. This model proposes four intervals in a cognitive cycle: mind wandering, awareness of mind wandering, shifting of attention, and sustained attention. People who train in this style of meditation cultivate their abilities to monitor cognitive processes related to attention and distraction, making them well suited to report on these mental events. Fourteen meditation practitioners performed breath-focused meditation while undergoing fMRI scanning. When participants realized their mind had wandered, they pressed a button and returned their focus to the breath. The four intervals above were then constructed around these button presses. We hypothesized that periods of mind wandering would be associated with default mode activity, whereas cognitive processes engaged during awareness of mind wandering, shifting of attention and sustained attention would engage attentional subnetworks. Analyses revealed activity in brain regions associated with the default mode during mind wandering, and in salience network regions during awareness of mind wandering. Elements of the executive network were active during shifting and sustained attention. Furthermore, activations during these cognitive phases were modulated by lifetime meditation experience. These findings support and extend theories about cognitive correlates of distributed brain networks.