Observation of the domain structures in ferromagnetically coupled (Fe{sub 97}Al{sub 3}){sub 85}N{sub 15}/Al{sub 2}O{sub 3} multilayers

Energy Technology Data Exchange (ETDEWEB)

Stobiecki, T.; Zoladz, M. [Department of Electronics, University of Mining and Metallurgy, 30-059 Krakow (Poland); Otto, M.; Roell, K. [Universitaet Gesamthochschule Kassel, Experimentalphysik IV, 34132 Kassel (Germany); Maass, W. [Unaxis GmbH, Alzenau (Germany)

2003-03-01

The strength of ferromagnetic (FM) coupling as a function of the spacer thickness of Al{sub 2}O{sub 3} was investigated by means of the Kerr microscopy used for analysis of magnetic domains. It was found that strong FM-coupling, strong uniaxial anisotropy and coherent rotation of the magnetization have been observed for the spacer thickness in the range of 0.2 nm{<=}t{<=}1 nm, however weak FM-coupling, patch domains and 360 -walls occur for the spacer thickness of t=2.5 nm. At a spacer thickness of t{>=}5 nm transition takes place from weak FM-coupling to the decoupled state where complex interlayer interactions and different types of the domain walls were observed. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

Clamping-induced changes of domain morphology in 88%Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-12%PbTiO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Chang, L.-W., E-mail: lchang01@qub.ac.uk; Gregg, J. M., E-mail: m.gregg@qub.ac.uk [Centre for Nanostructured Media, School of Maths and Physics, Queen' s University Belfast, Northern Ireland BT7 1NN (United Kingdom); Nagarajan, V.; Okatan, M. B. [School of Materials Science and Engineering, University of New South Wales, New South Wales 2052 (Australia)

2014-08-14

Domain microstructures in single crystal lamellae of 88%Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-12%PbTiO{sub 3} (cut from bulk using focused ion beam milling) have been mapped using both piezoresponse force microscopy and transmission electron microscopy. Dramatic changes from mottled microstructures typical of relaxors to larger scale domains typical of ferroelectrics have been noted. Stresses associated with substrate clamping are suspected as the cause for the transition from short- to long-range polar order, akin to effects induced by cation ordering achieved by thermal quenching.

Time domain passivity controller for 4-channel time-delay bilateral teleoperation.

Science.gov (United States)

Rebelo, Joao; Schiele, Andre

2015-01-01

This paper presents an extension of the time-domain passivity control approach to a four-channel bilateral controller under the effects of time delays. Time-domain passivity control has been used successfully to stabilize teleoperation systems with position-force and position-position controllers; however, the performance with such control architectures is sub-optimal both with and without time delays. This work extends the network representation of the time-domain passivity controller to the four-channel architecture, which provides perfect transparency to the user without time delay. The proposed architecture is based on modelling the controllers as dependent voltage sources and using only series passivity controllers. The obtained results are shown on a one degree-of-freedom setup and illustrate the stabilization behaviour of the proposed controller when time delay is present in the communication channel.

Epitaxial growth and control of the sodium content in Na{sub x}CoO{sub 2} thin films

Energy Technology Data Exchange (ETDEWEB)

Hildebrandt, Sandra; Komissinskiy, Philipp [Institute for Materials Science, Technische Universität Darmstadt, 64287 Darmstadt (Germany); Major, Marton [Institute for Materials Science, Technische Universität Darmstadt, 64287 Darmstadt (Germany); WIGNER RCP, RMKI, H-1525 Budapest, P.O.B. 49 (Hungary); Donner, Wolfgang [Institute for Materials Science, Technische Universität Darmstadt, 64287 Darmstadt (Germany); Alff, Lambert, E-mail: alff@oxide.tu-darmstadt.de [Institute for Materials Science, Technische Universität Darmstadt, 64287 Darmstadt (Germany)

2013-10-31

Single-phase c-axis oriented Na{sub x}CoO{sub 2} thin films were grown on (001) SrTiO{sub 3} single-crystal substrates, using pulsed laser deposition. X-ray diffraction analysis indicates the epitaxial growth of Na{sub x}CoO{sub 2} thin films in two domains, rotated in-plane by 15 and 45 degrees relative to [100] SrTiO{sub 3}. The sodium stoichiometry x of the films can be controlled in a range of 0.38 < x < 0.84 by in-situ post-deposition annealing the Na{sub x}CoO{sub 2} films at 720 – 760 °C in oxygen for 10 – 30 min. γ - Na{sub x}CoO{sub 2} films are obtained with a full width at half maximum of the (002) Na{sub x}CoO{sub 2} rocking curve below 0.2 degrees. The post-deposition annealing can substitute commonly used chemical deintercalation of Na which is typically associated with a loss in crystallinity. - Highlights: • Single phase Na{sub x}CoO{sub 2} thin films grown by pulsed laser deposition • Epitaxial relations of Na{sub x}CoO{sub 2} thin films on (001) SrTiO{sub 3} substrates • Multi-domain thin films • Control of sodium content by in-situ annealing of Na{sub x}CoO{sub 2} thin films.

SH3 Domains Differentially Stimulate Distinct Dynamin I Assembly Modes and G Domain Activity.

Directory of Open Access Journals (Sweden)

Sai Krishnan

Full Text Available Dynamin I is a highly regulated GTPase enzyme enriched in nerve terminals which mediates vesicle fission during synaptic vesicle endocytosis. One regulatory mechanism involves its interactions with proteins containing Src homology 3 (SH3 domains. At least 30 SH3 domain-containing proteins bind dynamin at its proline-rich domain (PRD. Those that stimulate dynamin activity act by promoting its oligomerisation. We undertook a systematic parallel screening of 13 glutathione-S-transferase (GST-tagged endocytosis-related SH3 domains on dynamin binding, GTPase activity and oligomerisation. No correlation was found between dynamin binding and their potency to stimulate GTPase activity. There was limited correlation between the extent of their ability to stimulate dynamin activity and the level of oligomerisation, indicating an as yet uncharacterised allosteric coupling of the PRD and G domain. We examined the two variants, dynamin Iab and Ibb, which differ in the alternately splice middle domain α2 helix. They responded differently to the panel of SH3s, with the extent of stimulation between the splice variants varying greatly between the SH3s. This study reveals that SH3 binding can act as a heterotropic allosteric regulator of the G domain via the middle domain α2 helix, suggesting an involvement of this helix in communicating the PRD-mediated allostery. This indicates that SH3 binding both stabilises multiple conformations of the tetrameric building block of dynamin, and promotes assembly of dynamin-SH3 complexes with distinct rates of GTP hydrolysis.

Acetylation within the N- and C-Terminal Domains of Src Regulates Distinct Roles of STAT3-Mediated Tumorigenesis.

Science.gov (United States)

Huang, Chao; Zhang, Zhe; Chen, Lihan; Lee, Hank W; Ayrapetov, Marina K; Zhao, Ting C; Hao, Yimei; Gao, Jinsong; Yang, Chunzhang; Mehta, Gautam U; Zhuang, Zhengping; Zhang, Xiaoren; Hu, Guohong; Chin, Y Eugene

2018-06-01

Posttranslational modifications of mammalian c-Src N-terminal and C-terminal domains regulate distinct functions. Myristoylation of G 2 controls its cell membrane association and phosphorylation of Y419/Y527 controls its activation or inactivation, respectively. We provide evidence that Src-cell membrane association-dissociation and catalytic activation-inactivation are both regulated by acetylation. In EGF-treated cells, CREB binding protein (CBP) acetylates an N-terminal lysine cluster (K5, K7, and K9) of c-Src to promote dissociation from the cell membrane. CBP also acetylates the C-terminal K401, K423, and K427 of c-Src to activate intrinsic kinase activity for STAT3 recruitment and activation. N-terminal domain phosphorylation (Y14, Y45, and Y68) of STAT3 by c-Src activates transcriptionally active dimers of STAT3. Moreover, acetyl-Src translocates into nuclei, where it forms the Src-STAT3 enhanceosome for gene regulation and cancer cell proliferation. Thus, c-Src acetylation in the N-terminal and C-terminal domains play distinct roles in Src activity and regulation. Significance: CBP-mediated acetylation of lysine clusters in both the N-terminal and C-terminal regions of c-Src provides additional levels of control over STAT3 transcriptional activity. Cancer Res; 78(11); 2825-38. ©2018 AACR . ©2018 American Association for Cancer Research.

Magnetic domain structure, crystal orientation, and magnetostriction of Tb{sub 0.27}Dy{sub 0.73}Fe{sub 1.95} solidified in various high magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Gao, Pengfei [Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China); Liu, Tie, E-mail: liutie@epm.neu.edu.cn [Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China); Dong, Meng [Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China); Yuan, Yi [School of Materials and Metallurgy, Northeastern University, Shenyang 110819 (China); Wang, Qiang [Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China)

2016-03-01

In this paper, we studied how applying a high magnetic field during solidification of Tb{sub 0.27}Dy{sub 0.73}Fe{sub 1.95} alloys affected their magnetic domain structure, crystal orientation, and magnetostriction. We observed the morphology of the magnetic domain during solidification, finding it change with the applied field: from fiber like (0 T) to dot like and closure mixed (4.4 T) to fiber like (8.8 T) to fishbone like (11.5 T). The alloy solidified at 4.4 T showed the best contrast of light and dark in its domain image, widest magnetic domain, fastest magnetization, and highest magnetostriction; this alloy is followed in descending order by the alloys solidified at 11.5 T, 8.8 T, and 0 T. The orientation of the (Tb, Dy)Fe{sub 2} phase changed with magnetic field from random (0 T) to 〈111〉 (4.4 T) to 〈113〉 (8.8 T) to 〈110〉 (11.5 T). The improvement in magnetostriction was likely caused by modification of both the magnetization process and the alloy microstructure. - Highlights: • We present how magnetic field affects magnetic domain structure of Tb{sub 0.27}Dy{sub 0.73}Fe{sub 1.95}. • Morphology and width of magnetic domain change with increasing magnetic field. • Magnetization and magnetostriction of alloy change with increasing magnetic field. • A transformation of random–〈111〉–〈113〉–〈110〉 for (Tb, Dy)Fe{sub 2} orientation forms.

Eclectic continuum, distinct discipline or sub-domain of communication studies? Theoretical considerations and empirical findings on the disciplinarity, multidisciplinarity and transdisciplinarity of journalism studies

Directory of Open Access Journals (Sweden)

Martin Löffelholz

2011-06-01

Full Text Available Is journalism studies a sub-domain of communication studies, adistinct discipline, a multidisciplinary merger or a transdisciplinary endeavour? This question is discussed by analyzing the 2008 and2009 volumes of seven academic journals focusing on journalismresearch. The sample includes 349 articles published in BrazilianJournalism Research, Ecquid Novi, Journalism & CommunicationMonographs, Journalism & Mass Communication Quarterly, PacificJournalism Review, Journalism Studies, or Journalism: Theory,Practice and Criticism. Overall, the findings reveal that journalismresearch mainly applies theoretical approaches and empiricalmethods deriving from other disciplines, particularly sociology, psychology or cultural studies. In many countries, however, journalism studies has reached a comparatively high level of institutionalization indicated by the large number of specific schools, professorships, professional associations and respective academic journals. In conclusion, we argue that journalism studies is a sub-domain of communication studies, which integrates andtranscends various disciplines aiming to become one of the axialsubjects of the 21st century.

ECLECTIC CONTINUUM, DISTINCT DISCIPLINE OR SUB-DOMAIN OF COMMUNICATION STUDIES? Theoretical considerations and empirical findings on the disciplinarity, multidisciplinarity and transdisciplinarity of journalism studies

Directory of Open Access Journals (Sweden)

Liane Rothenberger

2011-06-01

Full Text Available Is journalism studies a sub-domain of communication studies, adistinct discipline, a multidisciplinary merger or a transdisciplinary endeavour? This question is discussed by analyzing the 2008 and2009 volumes of seven academic journals focusing on journalismresearch. The sample includes 349 articles published in BrazilianJournalism Research, Ecquid Novi, Journalism & CommunicationMonographs, Journalism & Mass Communication Quarterly, PacificJournalism Review, Journalism Studies, or Journalism: Theory,Practice and Criticism. Overall, the findings reveal that journalismresearch mainly applies theoretical approaches and empiricalmethods deriving from other disciplines, particularly sociology, psychology or cultural studies. In many countries, however, journalism studies has reached a comparatively high level of institutionalization indicated by the large number of specific schools, professorships, professional associations and respective academic journals. In conclusion, we argue that journalism studies is a sub-domain of communication studies, which integrates andtranscends various disciplines aiming to become one of the axialsubjects of the 21st century.

Distinct effects of Cr bulk doping and surface deposition on the chemical environment and electronic structure of the topological insulator Bi{sub 2}Se{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Yilmaz, Turgut, E-mail: yilmaz@phys.uconn.edu [Department of Physics, University of Connecticut, Storrs, CT 06269 (United States); Hines, William [Department of Physics, University of Connecticut, Storrs, CT 06269 (United States); Sun, Fu-Chang [Department of Materials Science and Engineering, University of Connecticut, Storrs, CT 06269 (United States); Pletikosić, Ivo [Department of Physics, Princeton University, Princeton, NJ 08544 (United States); Budnick, Joseph [Department of Physics, University of Connecticut, Storrs, CT 06269 (United States); Valla, Tonica [Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Sinkovic, Boris [Department of Physics, University of Connecticut, Storrs, CT 06269 (United States)

2017-06-15

Highlights: • Cr doping into the bulk of Bi{sub 2}Se{sub 3} opens an energy gap at the Dirac point which is observable in the non-magnetic state. • Cr surface deposition does not lead to open an energy gap at the Dirac point of Bi{sub 2}Se{sub 3}. • Formation of two distinct Bi and Cr core level peaks was observed upon the deposition of Cr on the surface of Bi{sub 2}Se{sub 3}. - Abstract: In this report, it is shown that Cr doped into the bulk and Cr deposited on the surface of Bi{sub 2}Se{sub 3} films produced by molecular beam epitaxy (MBE) have strikingly different effects on both the electronic structure and chemical environment. Angle resolved photoemission spectroscopy (ARPES) shows that Cr doped into the bulk opens a surface state energy gap which can be seen at room temperature; much higher than the measured ferromagnetic transition temperature of ≈10 K. On the other hand, similar ARPES measurements show that the surface states remain gapless down to 15 K for films with Cr surface deposition. In addition, core-level photoemission spectroscopy of the Bi 5d, Se 3d, and Cr 3p core levels show distinct differences in the chemical environment for the two methods of Cr introduction. Surface deposition of Cr results in the formation of shoulders on the lower binding energy side for the Bi 5d peaks and two distinct Cr 3p peaks indicative of two Cr sites. These striking differences suggests an interesting possibility that better control of doping at only near surface region may offer a path to quantum anomalous Hall states at higher temperatures than reported in the literature.

The Nature of the Distinctive Microscopic Features in R<sub>5sub>(Si_xGe>1-xsub>)>4sub> Magnetic Refrigeration Materials

Energy Technology Data Exchange (ETDEWEB)

Ugurlu, Ozan [Iowa State Univ., Ames, IA (United States)

2006-01-01

Magnetic refrigeration is a promising technology that offers a potential for high energy efficiency. The giant magnetocaloric effect of the R<sub>5sub>(Si<sub>x>, Ge<sub>1-xsub>)>4sub> alloys (where R=rare-earth and O ≤ x ≤ 1), which was discovered in 1997, make them perfect candidates for magnetic refrigeration applications. In this study the microstructures of Gd<sub>5sub>(Six>, Ge<sub>1-xsub>)>4sub> alloys have been characterized using electron microscopy techniques, with the focus being on distinctive linear features first examined in 1999. These linear features have been observed in R<sub>5sub>(Six>, Ge<sub>1-xsub>)>4sub> alloys prepared from different rare-earths (Gd, Tb, Dy and Er) with different crystal structures (Gd<sub>5sub>Si>4sub>-type orthorhombic, monoclinic and Gd<sub>5sub>Ge>4sub>-type orthorhombic). Systematic scanning electron microscope studies revealed that these linear features are actually thin-plates, which grow along specific directions in the matrix material. The crystal structure of the thin-plates has been determined as hexagonal with lattice parameters a=b=8.53 Å and c=6.40 Å using selected area diffraction (SAD). Energy dispersive spectroscopy analysis, carried out in both scanning and transmission electron microscopes, showed that the features have a composition approximating to R<sub>5sub>Six,Ge>1-xsub>)>3sub>.phase. Orientation relationship between the matrix and the thin-plates has been calculated as [- 1010](1-211)<sub>p>//[010](10-2)<sub>m>. The growth direction of the thin plates are calculated as (22 0 19) and (-22 0 19) by applying the Ag approach of Zhang and Purdy to the SAD patterns of this system. High Resolution TEM images of the Gd_{5sub>Ge>4sub> were used to study the crystallographic relationship. A terrace-ledge structure was observed at the interface and a 7° rotation of the reciprocal lattices}

A note on eigenfrequency sensitivities and structural eigenfrequency optimization based on local sub-domain frequencies

DEFF Research Database (Denmark)

Pedersen, Pauli; Pedersen, Niels Leergaard

2014-01-01

foundation. A numerical heuristic redesign procedure is proposed and illustrated with examples. For the ideal case, an optimality criterion is fulfilled if the design have the same sub-domain frequency (local Rayleigh quotient). Sensitivity analysis shows an important relation between squared system...... eigenfrequency and squared local sub-domain frequency for a given eigenmode. Higher order eigenfrequenciesmay also be controlled in this manner. The presented examples are based on 2D finite element models with the use of subspace iteration for analysis and a heuristic recursive design procedure based...... on the derived optimality condition. The design that maximize a frequency depend on the total amount of available material and on a necessary interpolation as illustrated by different design cases.In this note we have assumed a linear and conservative eigenvalue problem without multiple eigenvalues. The presence...

Interferometrically enhanced sub-terahertz picosecond imaging utilizing a miniature collapsing-field-domain source

Science.gov (United States)

Vainshtein, Sergey N.; Duan, Guoyong; Mikhnev, Valeri A.; Zemlyakov, Valery E.; Egorkin, Vladimir I.; Kalyuzhnyy, Nikolay A.; Maleev, Nikolai A.; Näpänkangas, Juha; Sequeiros, Roberto Blanco; Kostamovaara, Juha T.

2018-05-01

Progress in terahertz spectroscopy and imaging is mostly associated with femtosecond laser-driven systems, while solid-state sources, mainly sub-millimetre integrated circuits, are still in an early development phase. As simple and cost-efficient an emitter as a Gunn oscillator could cause a breakthrough in the field, provided its frequency limitations could be overcome. Proposed here is an application of the recently discovered collapsing field domains effect that permits sub-THz oscillations in sub-micron semiconductor layers thanks to nanometer-scale powerfully ionizing domains arising due to negative differential mobility in extreme fields. This shifts the frequency limit by an order of magnitude relative to the conventional Gunn effect. Our first miniature picosecond pulsed sources cover the 100-200 GHz band and promise milliwatts up to ˜500 GHz. Thanks to the method of interferometrically enhanced time-domain imaging proposed here and the low single-shot jitter of ˜1 ps, our simple imaging system provides sufficient time-domain imaging contrast for fresh-tissue terahertz histology.

Functional analysis of the NH{sub 2}-terminal hydrophobic region and BRICHOS domain of GKN1

Energy Technology Data Exchange (ETDEWEB)

Yoon, Jung Hwan; Choi, Yoo Jin; Choi, Won Suk; Nam, Suk Woo; Lee, Jung Young; Park, Won Sang, E-mail: wonsang@catholic.ac.kr

2013-11-01

Highlights: •NH{sub 2}-terminal and BRICHOS domain of GKN1 inhibited tumor cell growth. •NH{sub 2}-terminal and BRICHOS domain of GKN1 regulated cell cycle. •NH{sub 2}-terminal and BRICHOS domain of GKN1 inhibited epigenetic regulators. -- Abstract: Gastrokine 1 (GKN1) protects the gastric antral mucosa and promotes healing by facilitating restitution and proliferation after injury. GKN1 is down-regulated in Helicobacter pylori-infected gastric epithelial cells and loss of GKN1 expression is tightly associated with gastric carcinogenesis. However, the underlying mechanisms as a tumor suppressor are largely unknown. Presently, the hydrophobic region and BRICHOS domain of GKN1, pGKN1{sup D13N}, pGKN1{sup Δ68–199}, and pGKN1{sup Δ1–67,165–199} were shown to suppress gastric cancer cell growth and recapitulate GKN1 functions. As well, the hydrophobic region and BRICHOS domain of GKN1 had a synergistic anti-cancer effect with 5-FU on tumor cell growth, implying that the NH{sub 2}-terminal hydrophobic region and BRICHOS domain of GKN1 are sufficient for tumor suppression, thereby suggesting a therapeutic intervention for gastric cancer. Also, its domain inducing endogenous miR-185 directly targeted the epigenetic effectors DNMT1 and EZH2 in gastric cancer cells. Our results suggest that the NH{sub 2}-terminal hydrophobic region and BRICHOS domain of GKN1 are sufficient for its tumor suppressor activities.

Distinct mechanisms of a phosphotyrosyl peptide binding to two SH2 domains.

Science.gov (United States)

Pang, Xiaodong; Zhou, Huan-Xiang

2014-05-01

Protein phosphorylation is very common post-translational modification, catalyzed by kinases, for signaling and regulation. Phosphotyrosines frequently target SH2 domains. The spleen tyrosine kinase (Syk) is critical for tyrosine phosphorylation of multiple proteins and for regulation of important pathways. Phosphorylation of both Y342 and Y346 in Syk linker B is required for optimal signaling. The SH2 domains of Vav1 and PLC-γ both bind this doubly phosphorylated motif. Here we used a recently developed method to calculate the effects of Y342 and Y346 phosphorylation on the rate constants of a peptide from Syk linker B binding to the SH2 domains of Vav1 and PLC-γ. The predicted effects agree well with experimental observations. Moreover, we found that the same doubly phosphorylated peptide binds the two SH2 domains via distinct mechanisms, with apparent rigid docking for Vav1 SH2 and dock-and-coalesce for PLC-γ SH2.

Conflict detection and resolution rely on a combination of common and distinct cognitive control networks.

Science.gov (United States)

Li, Qi; Yang, Guochun; Li, Zhenghan; Qi, Yanyan; Cole, Michael W; Liu, Xun

2017-12-01

Cognitive control can be activated by stimulus-stimulus (S-S) and stimulus-response (S-R) conflicts. However, whether cognitive control is domain-general or domain-specific remains unclear. To deepen the understanding of the functional organization of cognitive control networks, we conducted activation likelihood estimation (ALE) from 111 neuroimaging studies to examine brain activation in conflict-related tasks. We observed that fronto-parietal and cingulo-opercular networks were commonly engaged by S-S and S-R conflicts, showing a domain-general pattern. In addition, S-S conflicts specifically activated distinct brain regions to a greater degree. These regions were implicated in the processing of the semantic-relevant attribute, including the inferior frontal cortex (IFC), superior parietal cortex (SPC), superior occipital cortex (SOC), and right anterior cingulate cortex (ACC). By contrast, S-R conflicts specifically activated the left thalamus, middle frontal cortex (MFC), and right SPC, which were associated with detecting response conflict and orienting spatial attention. These findings suggest that conflict detection and resolution involve a combination of domain-general and domain-specific cognitive control mechanisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Depinning of the ferroelectric domain wall in congruent LiNbO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Lee, Donghwa, E-mail: donghwa96@jnu.ac.kr [School of Materials Science and Engineering, Chonnam National University, Gwangju 61186 (Korea, Republic of); Gopalan, Venkatraman [Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Phillpot, Simon R. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2016-08-22

The high coercive field, E{sub c}, of congruent LiNbO{sub 3} can be reduced by doping with Mg or Zn atoms, or by increasing the temperature above a threshold value. The physical origin for this reduction is not currently understood. Here, density functional theory calculations illustrate the atomic origin of the change in the switching field of the congruent LiNbO{sub 3}. They show that the high E{sub c} in the congruent LiNbO{sub 3} is a result of niobium antisite atoms on the lithium sublattice, pinning the motion of the domain walls. Thus, the healing of antisites by diffusion can significantly reduce the coercive field. In addition, this work demonstrates that the migration of these niobium antisites can be enhanced by doping or by changing the temperature. Thus, the depinning process of the congruent LiNbO{sub 3} is understood by the migration of the niobium antisite defect across the domain wall.

Disparity of secondary electron emission in ferroelectric domains of YMnO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Cheng, Shaobo; Deng, S. Q.; Yuan, Wenjuan; Yan, Yunjie; Zhu, Jing, E-mail: jzhu@tsinghua.edu.cn [National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, The State Key Laboratory of Ceramics and Fine Processing, Key Laboratory of Advanced Materials (MOE), Tsinghua University, Beijing 100084 (China); Li, J.; Li, J. Q. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2015-07-20

The applications of multiferroic materials require our understanding about the behaviors of domains with different polarization directions. Taking advantage of the scanning electron microscope, we investigate the polar surface of single crystal YMnO{sub 3} sample in secondary electron (SE) mode. By slowing down the scanning speed of electron beam, the negative surface potential of YMnO{sub 3} can be realized, and the domain contrast can be correspondingly changed. Under this experimental condition, with the help of a homemade Faraday cup, the difference of intrinsic SE emission coefficients of antiparallel domains is measured to be 0.12 and the downward polarization domains show a larger SE emission ability. Our results indicate that the total SE emission of this material can be altered by changing the ratio of the antiparallel domains, which provide an avenue for device design with this kind of materials.

The structure of a conserved piezo channel domain reveals a topologically distinct β sandwich fold.

Science.gov (United States)

Kamajaya, Aron; Kaiser, Jens T; Lee, Jonas; Reid, Michelle; Rees, Douglas C

2014-10-07

Piezo has recently been identified as a family of eukaryotic mechanosensitive channels composed of subunits containing over 2,000 amino acids, without recognizable sequence similarity to other channels. Here, we present the crystal structure of a large, conserved extramembrane domain located just before the last predicted transmembrane helix of C. elegans PIEZO, which adopts a topologically distinct β sandwich fold. The structure was also determined of a point mutation located on a conserved surface at the position equivalent to the human PIEZO1 mutation found in dehydrated hereditary stomatocytosis patients (M2225R). While the point mutation does not change the overall domain structure, it does alter the surface electrostatic potential that may perturb interactions with a yet-to-be-identified ligand or protein. The lack of structural similarity between this domain and any previously characterized fold, including those of eukaryotic and bacterial channels, highlights the distinctive nature of the Piezo family of eukaryotic mechanosensitive channels. Copyright © 2014 Elsevier Ltd. All rights reserved.

The H{sub 1}–H{sub 2} domain of the α{sub 1} isoform of Na{sup +}–K{sup +}–ATPase is involved in ouabain toxicity in rat ventricular myocytes

Energy Technology Data Exchange (ETDEWEB)

Xiong, Chen; Li, Jun-xia; Guo, Hui-cai; Zhang, Li-nan; Guo, Wei; Meng, Jing; Wang, Yong-li, E-mail: wangyongli@gmail.com

2012-07-01

The composition of different isoforms of Na{sup +}-K{sup +}-ATPase (NKA, Na/K pump) in ventricular myocytes is an important factor in determining the therapeutic effect and toxicity of cardiac glycosides (CGs) on heart failure. The mechanism whereby CGs cause these effects is still not completely clear. In the present study, we prepared two site-specific antibodies (SSA78 and WJS) against the H{sub 1}–H{sub 2} domain of α{sub 1} and α{sub 2} isoforms of NKA in rat heart, respectively, and compared their influences on the effect of ouabain (OUA) in isolated rat ventricular myocytes. SSA78 or WJS, which can specifically bind with the α{sub 1} or α{sub 2} isoform, were assessed with enzyme linked immunosorbent assay (ELISA), Western blot and immunofluorescent staining methods. Preincubation of myocytes with SSA78 inhibited low OUA affinity pump current but not high OUA affinity pump current, reduced the rise in cytosolic calcium concentration ([Ca{sup 2+}]{sub i}), attenuated mitochondrial Ca{sup 2+} overload, restored mitochondrial membrane potential reduction, and delayed the decrease of the myocardial contractile force as well as the occurrence of arrhythmic contraction induced by high concentrations (1 mM) but not low concentrations (1 μM) of OUA. Similarly, preincubation of myocytes with WJS inhibited high OUA affinity pump current, reduced the increase of [Ca{sup 2+}]{sub i} and the contractility induced by 1 μM but not that induced by 1 mM OUA. These results indicate that the H{sub 1}–H{sub 2} domain of the NKA α{sub 1} isoform mediates OUA-induced cardiac toxicity in rat ventricular myocytes, and inhibitors for this binding site may be used as an adjunct to CGs treatment for cardiovascular disease. -- Highlights: ► We prepared two antibodies against the H{sub 1}-H{sub 2} domain of α{sub 1} and α{sub 2} isoforms of NKA. ► The H{sub 1}-H{sub 2} domain of the NKA α{sub 1} isoform mediates OUA-induced cardiac toxicity. ► The H{sub 1}-H{sub 2

Colossal anisotropic resistivity and oriented magnetic domains in strained La{sub 0.325}Pr{sub 0.3}Ca{sub 0.375}MnO{sub 3} films

Energy Technology Data Exchange (ETDEWEB)

Jiang, Tao; Yang, Shengwei; Liu, Yukuai; Zhao, Wenbo; Feng, Lei; Li, Xiaoguang, E-mail: lixg@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at Microscale, Department of Physics, University of Science and Technology of China, Hefei 230026 (China); Zhou, Haibiao; Lu, Qingyou [Hefei National Laboratory for Physical Sciences at Microscale, Department of Physics, University of Science and Technology of China, Hefei 230026 (China); High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei 230031 (China); Hou, Yubin [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei 230031 (China)

2014-05-19

Magnetic and resistive anisotropies have been studied for the La{sub 0.325}Pr{sub 0.3}Ca{sub 0.375}MnO{sub 3} films with different thicknesses grown on low symmetric (011)-oriented (LaAlO{sub 3}){sub 0.3}(SrAl{sub 0.5}Ta{sub 0.5}O{sub 3}){sub 0.7} substrates. In the magnetic and electronic phase separation region, a colossal anisotropic resistivity (AR) of ∼10{sup 5}% and an anomalous large anisotropic magnetoresistance can be observed for 30 nm film. However, for 120 nm film, the maximum AR decreases significantly (∼2 × 10{sup 3}%) due to strain relaxation. The colossal AR is strongly associated with the oriented formation of magnetic domains, and the features of the strain effects are believed to be useful for the design of artificial materials and devices.

Morin-like spin canting in the magnetic CaFe{sub 5}O{sub 7} ferrite: A combined neutron and Mössbauer study

Energy Technology Data Exchange (ETDEWEB)

Delacotte, C.; Bréard, Y.; Caignaert, V.; Hardy, V. [Laboratoire CRISMAT ENSICAEN UMR CNRS 6508, 6 Boulevard du Maréchal Juin, 14050 Caen Cedex 04 (France); Greneche, J.M. [Institut des Molécules et Matériaux du Mans, IMMM UMR CNRS 6283, Avenue Olivier Messiaen, 72085 Le Mans (France); Hébert, S. [Laboratoire CRISMAT ENSICAEN UMR CNRS 6508, 6 Boulevard du Maréchal Juin, 14050 Caen Cedex 04 (France); Suard, E. [Institut Laue-Langevin, 71 avenue des Martyrs, 38042 Grenoble Cedex 9 (France); Pelloquin, D. [Laboratoire CRISMAT ENSICAEN UMR CNRS 6508, 6 Boulevard du Maréchal Juin, 14050 Caen Cedex 04 (France)

2017-03-15

Magnetic structure of CaFe{sub 5}O{sub 7} ferrite has been studied jointly from neutron powder diffraction data and spectroscopic Mössbauer measurements in the thermal range from 5 to 500 K. This coupled work highlights three distinct magnetic domains around two specific temperatures: T{sub M}=125 K and T{sub N}=360 K. The latter corroborates the structural monoclinic-orthorhombic transition previously reported by transmission electron microscopy techniques and X-ray thermodiffractometry. Complementary heat capacity measurements have confirmed this first order transition with a sharp peak at 360 K. Interestingly, this large study has revealed a second magnetic transition associated to a spin rotation at 125 K similar to this one reported by Morin in α-Fe{sub 2}O{sub 3} hematite at T{sub M}=260 K. - Graphical abstract: Magnetic structure of CaFe{sub 5}O{sub 7} ferrite has been studied jointly from neutron powder diffraction data and spectroscopic Mössbauer measurements in the thermal range from 5 to 500 K. This coupled work highlights three distinct magnetic domains around two specific temperatures: T{sub M}=125 K and T{sub N}=360 K. Interestingly, this large study has revealed a magnetic transition associated to a spin rotation at 125 K similar to this one reported by Morin in α-Fe{sub 2}O{sub 3} hematite at T{sub M}=260 K.

Interaction of the amyloid precursor protein-like protein 1 (APLP1) E2 domain with heparan sulfate involves two distinct binding modes

Energy Technology Data Exchange (ETDEWEB)

Dahms, Sven O., E-mail: sdahms@fli-leibniz.de [Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena (Germany); Mayer, Magnus C. [Freie Universität Berlin, Thielallee 63, 14195 Berlin (Germany); Miltenyi Biotec GmbH, Robert-Koch-Strasse 1, 17166 Teterow (Germany); Roeser, Dirk [Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena (Germany); Multhaup, Gerd [McGill University Montreal, Montreal, Quebec H3G 1Y6 (Canada); Than, Manuel E., E-mail: sdahms@fli-leibniz.de [Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena (Germany)

2015-03-01

Two X-ray structures of APLP1 E2 with and without a heparin dodecasaccharide are presented, revealing two distinct binding modes of the protein to heparan sulfate. The data provide a mechanistic explanation of how APP-like proteins bind to heparan sulfates and how they specifically recognize nonreducing structures of heparan sulfates. Beyond the pathology of Alzheimer’s disease, the members of the amyloid precursor protein (APP) family are essential for neuronal development and cell homeostasis in mammals. APP and its paralogues APP-like protein 1 (APLP1) and APP-like protein 2 (APLP2) contain the highly conserved heparan sulfate (HS) binding domain E2, which effects various (patho)physiological functions. Here, two crystal structures of the E2 domain of APLP1 are presented in the apo form and in complex with a heparin dodecasaccharide at 2.5 Å resolution. The apo structure of APLP1 E2 revealed an unfolded and hence flexible N-terminal helix αA. The (APLP1 E2){sub 2}–(heparin){sub 2} complex structure revealed two distinct binding modes, with APLP1 E2 explicitly recognizing the heparin terminus but also interacting with a continuous heparin chain. The latter only requires a certain register of the sugar moieties that fits to a positively charged surface patch and contributes to the general heparin-binding capability of APP-family proteins. Terminal binding of APLP1 E2 to heparin specifically involves a structure of the nonreducing end that is very similar to heparanase-processed HS chains. These data reveal a conserved mechanism for the binding of APP-family proteins to HS and imply a specific regulatory role of HS modifications in the biology of APP and APP-like proteins.

The neural signature of self-concept development in adolescence: The role of domain and valence distinctions

Directory of Open Access Journals (Sweden)

R. van der Cruijsen

2018-04-01

Full Text Available Neuroimaging studies in adults showed that cortical midline regions including medial prefrontal cortex (mPFC and posterior parietal cortex (PPC are important in self-evaluations. The goals of this study were to investigate the contribution of these regions to self-evaluations in late childhood, adolescence, and early adulthood, and to examine whether these differed per domain (academic, physical and prosocial and valence (positive versus negative. Also, we tested whether this activation changes across adolescence. For this purpose, participants between ages 11–21-years (N = 150 evaluated themselves on trait sentences in an fMRI session. Behaviorally, adolescents rated their academic traits less positively than children and young adults. The neural analyses showed that evaluating self-traits versus a control condition was associated with increased activity in mPFC (domain-general effect, and positive traits were associated with increased activity in ventral mPFC (valence effect. Self-related mPFC activation increased linearly with age, but only for evaluating physical traits. Furthermore, an adolescent-specific decrease in striatum activation for positive self traits was found. Finally, we found domain-specific neural activity for evaluating traits in physical (dorsolateral PFC, dorsal mPFC and academic (PPC domains. Together, these results highlight the importance of domain distinctions when studying self-concept development in late childhood, adolescence, and early adulthood. Keywords: Self, fMRI, Adolescence, Development, Medial prefrontal cortex, Self-concept

Thickness dependence of magnetic anisotropy and domains in amorphous Co{sub 40}Fe{sub 40}B{sub 20} thin films grown on PET flexible substrates

Energy Technology Data Exchange (ETDEWEB)

Tang, Zhenhua, E-mail: tangzhenhua1988@163.com [Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Ni, Hao [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China); College of science, China university of petroleum, Qingdao, Shandong 266580 China (China); Lu, Biao [Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Zheng, Ming [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Huang, Yong-An [Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Lu, Sheng-Guo, E-mail: sglu@gdut.edu.cn [Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Tang, Minghua [Key Laboratory of Low Dimensional Materials and Application Technology, Ministry of Education (Xiangtan University), Xiangtan, Hunan 411105 (China); Gao, Ju [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

2017-03-15

The amorphous Co{sub 40}Fe{sub 40}B{sub 20} (CoFeB) films (5–200 nm in thickness) were grown on flexible polyethylene terephthalate (PET) substrates using the DC magnetron-sputtering method. The thickness dependence of structural and magnetic properties of flexible CoFeB thin films was investigated in detail. The in-plane uniaxial magnetic anisotropy induced by strain as a function of thickness was obtained in flexible CoFeB thin films, and a critical thickness of ~150 nm for in-plane magnetic anisotropy was observed. Moreover, the domains and the uniaxial anisotropy as a function of angular direction of applied magnetic field were characterized. The results show potential for designing CoFeB-based flexible spintronic devices in which the physical parameters could be tailored by controlling the thickness of the thin film. - Graphical abstract: The in-plane uniaxial magnetic anisotropy induced by strain as a function of thickness was obtained in flexible CoFeB thin films, and a critical thickness of ~150 nm for in-plane magnetic anisotropy was observed. Moreover, the domains and the uniaxial anisotropy as a function of angular direction of applied magnetic field were characterized. - Highlights: • The thickness effect on the magnetic properties in amorphous CoFeB thin films grown on flexible substrates was investigated. • The in-plane uniaxial magnetic anisotropy induced by strains was observed. • A critical thickness of ~ 150 nm for the flexible CoFeB thin film on PET substrate was obtained.

Mismatch Negativity as an Indicator of Cognitive Sub-Domain Dysfunction in Amyotrophic Lateral Sclerosis

Directory of Open Access Journals (Sweden)

Parameswaran Mahadeva Iyer

2017-08-01

Full Text Available ObjectiveTo evaluate the utility of mismatch negativity (MMN, a neurophysiologic marker of non-motor cognitive processing, in amyotrophic lateral sclerosis (ALS.Methods89 patients, stratified into 4 different phenotypic presentations of ALS (67 spinal-onset, 15 bulbar-onset, 7 ALS-FTD, 7 C9ORF72 gene careers, and 19 matched controls underwent 128-channel EEG data recording. Subjects were presented with standard auditory tones interleaved with pitch-deviant tones in three recording blocks. The MMN response was quantified by peak amplitude, peak delay, average amplitude, and average delay, 100–300 ms after stimuli. 64 patients underwent cognitive screening using the Edinburgh Cognitive and Behavioural ALS Screen (ECAS, and 38 participants underwent contemporaneous cognitive assessment using the Stroop Color–Word Interference test (CWIT, which measures attention shift, inhibitory control, and error monitoring.ResultsThe MMN response was observed in frontal and frontocentral regions of patient and control groups. Compared to controls, waveforms were attenuated in early onset, and the average delay was significantly increased in all of the ALS subgroups, with no significant difference between subgroups. Comparing with the control response, the ALS MMN response clustered into four new subgroups characterized by differences in response latency. The increased average delay correlated with changes in the Stroop CWIT; however, it did not show a direct relationship with age, gender, traditional phenotypes, revised ALS Functional Rating Scale, or ECAS scores.Conclusion and significanceThe MMN response in ALS patients reflects the cognitive dysfunction in specific sub-domains, as the new patient subgroups, identified by cluster analysis, do not segregate with existing clinical or cognitive classifications. Event-related potentials can provide additional quantitative neurophysiologic measures of impairment in specific cognitive sub-domains from which it

Domain wall and interphase boundary motion in (1−x)Bi(Mg{sub 0.5}Ti{sub 0.5})O{sub 3}–xPbTiO{sub 3} near the morphotropic phase boundary

Energy Technology Data Exchange (ETDEWEB)

Tutuncu, Goknur [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Chen, Jun; Fan, Longlong [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Fancher, Chris M.; Zhao, Jianwei [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Forrester, Jennifer S.; Jones, Jacob L., E-mail: JacobJones@ncsu.edu [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

2016-07-28

Electric field-induced changes in the domain wall motion of (1−x)Bi(Mg{sub 0.5}Ti{sub 0.5})O{sub 3}–xPbTiO{sub 3} (BMT-xPT) near the morphotropic phase boundary (MPB) where x = 0.37 (BMT-37PT) and x = 0.38 (BMT-38PT), are studied by means of synchrotron x-ray diffraction. Through Rietveld analysis and profile fitting, a mixture of coexisting monoclinic (Cm) and tetragonal (P4mm) phases is identified at room temperature. Extrinsic contributions to the property coefficients are evident from electric-field-induced domain wall motion in both the tetragonal and monoclinic phases, as well as through the interphase boundary motion between the two phases. Domain wall motion in the tetragonal and monoclinic phases for BMT-37PT is larger than that of BMT-38PT, possibly due to this composition's closer proximity to the MPB. Increased interphase boundary motion was also observed in BMT-37PT. Lattice strain, which is a function of both intrinsic piezoelectric strain and elastic interactions of the grains (the latter originating from domain wall and interphase boundary motion), is similar for the respective tetragonal and monoclinic phases.

Magnetocrystalline anisotropy and magnetic domain structure of ErFe{sub 11}Ti and HoFe{sub 11}Ti compounds

Energy Technology Data Exchange (ETDEWEB)

Pastushenkov, Yury G. [Physics Department of Tver State University, 17000 Tver (Russian Federation); Skokov, Konstantin P. [Physics Department of Tver State University, 17000 Tver (Russian Federation); Skourski, Yury [Leibniz-Institute for Solid State and Material Research, 01171 Dresden (Germany); Lebedeva, Ludmila [Physics Department of Tver State University, 17000 Tver (Russian Federation); Ivanova, Tatyana [Physics Department of Moscow Stae University, 119889 Moscow (Russian Federation); Grushichev, Anton [Physics Department of Tver State University, 17000 Tver (Russian Federation)]. E-mail: yupast@tversu.ru; Mueller, Karl-Hartmut [Leibniz-Institute for Solid State and Material Research, 01171 Dresden (Germany)

2006-05-15

Tetragonal ThMn{sub 12}-type single crystalline ErFe{sub 11}Ti and HoFe{sub 11}Ti samples have been investigated by magnetization measurements and by observations of the magnetic domain structure at various temperatures between 10 and 300K. The magnetic structure of ErFe{sub 11}Ti changes from room temperature 'easy axis' (c-axis) type to conical at spin-reorientation temperature T{sub SR}=50K. The HoFe{sub 11}Ti has a metastable anisotropy energy minimum in the a-direction at T<40K. It leads to a first-order magnetization process detected by magnetization measurements along the a-axis in this temperature region.

FY1995 ultrafast photonic devices using dielectric domain superlattice; 1995 nendo yudentai domain chokoshi wo mochiita chokosoku photonic device

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-31

All optical wavelength conversion around 1550nm is of great importance for the wavelength division multiplexing optical communication system. A dielectric domain superlattice, which has a periodically domain inverted structure, has a wide potential for the various nonlinear interactions such as second harmonic generation (SHG) and difference frequency generation (DFG). The purpose of our research is to establish the theoretical bases and fabrication processes of the guided-wave wavelength converter based on the DFG by domain-inverted LiTaO{sub 3}. We have investigated basic characteristics of guided-wave DFG devices and developed the domain-inversion process by an electric field poling utilizing a liquid electrolyte consisting of LiCI in deionized water as a electrode for applying the electric field to LiTaO{sub 3} substrate. By controlling the injection current for the domain inversion precisely, we fabricated successfully uniform domain-inverted structures. 0.5mm-thick domain-inverted LiTaO{sub 3} of 7.8, 17.2 and 21.3 {mu}m periods and 0.5 duty ratio were obtained by optimizing electrode structure and the domain-inversion process. Waveguide structures can increase the conversion efficiency of DFG by several orders of magnitude over bulk interactions. We have also developed waveguide fabrication process for the domain-inverted LiTaO{sub 3} substrate. Low loss proton-exchanged waveguides were formed by annealed proton exchange technique without a degradation of the domain inversion structure. Domain-controlled nonlinear optics by designing the ferroelectric domain structure of LiTaO{sub 3} and LiNbO{sub 3} make it possible to extend all the spectral range from ultra-violet to far-infrared and THz wave region. (NEDO)

SH2 and SH3 domains: elements that control interactions of cytoplasmic signaling proteins.

Science.gov (United States)

Koch, C A; Anderson, D; Moran, M F; Ellis, C; Pawson, T

1991-05-03

Src homology (SH) regions 2 and 3 are noncatalytic domains that are conserved among a series of cytoplasmic signaling proteins regulated by receptor protein-tyrosine kinases, including phospholipase C-gamma, Ras GTPase (guanosine triphosphatase)-activating protein, and Src-like tyrosine kinases. The SH2 domains of these signaling proteins bind tyrosine phosphorylated polypeptides, implicated in normal signaling and cellular transformation. Tyrosine phosphorylation acts as a switch to induce the binding of SH2 domains, thereby mediating the formation of heteromeric protein complexes at or near the plasma membrane. The formation of these complexes is likely to control the activation of signal transduction pathways by tyrosine kinases. The SH3 domain is a distinct motif that, together with SH2, may modulate interactions with the cytoskeleton and membrane. Some signaling and transforming proteins contain SH2 and SH3 domains unattached to any known catalytic element. These noncatalytic proteins may serve as adaptors to link tyrosine kinases to specific target proteins. These observations suggest that SH2 and SH3 domains participate in the control of intracellular responses to growth factor stimulation.

Transmission of reactive pulsed laser deposited VO{sub 2} films in the THz domain

Energy Technology Data Exchange (ETDEWEB)

Émond, Nicolas; Hendaoui, Ali; Ibrahim, Akram; Al-Naib, Ibraheem; Ozaki, Tsuneyuki; Chaker, Mohamed, E-mail: chaker@emt.inrs.ca

2016-08-30

Highlights: • Synthesis of vanadium dioxide (VO{sub 2}) thin films as a function of oxygen pressure (2–25 mTorr) using Reactive Pulsed Laser Deposition (RPLD). • Characterization of RPLD-grown VO{sub 2} thin films in the THz frequency range. • THz switches and/or sensors require VO{sub 2} films deposited at low oxygen pressure (i.e. low transition temperature, large amplitude contrast of THz transmission, narrow hysteresis width). • THz optical memory applications require VO{sub 2} films deposited at high oxygen pressure (broad hysteresis width). - Abstract: This work reports on the characteristics of the insulator-to-metal transition (IMT) of reactive pulsed laser deposited vanadium dioxide (VO{sub 2}) films in the terahertz (THz) frequency range, namely the transition temperature T{sub IMT}, the amplitude contrast of the THz transmission over the IMT ΔA, the transition sharpness ΔT and the hysteresis width ΔH. XRD analysis shows the sole formation of VO{sub 2} monoclinic structure with an enhancement of (011) preferential orientation when varying the O{sub 2} pressure (P{sub O2}) during the deposition process from 2 to 25 mTorr. THz transmission measurements as a function of temperature reveal that VO{sub 2} films obtained at low P{sub O2} exhibit low T{sub IMT}, large ΔA, and narrow ΔH. Increasing P{sub O2} results in VO{sub 2} films with higher T{sub IMT}, smaller ΔA, broader ΔH and asymmetric hysteresis loop. The good control of the VO{sub 2} IMT features in the THz domain could be further exploited for the development of advanced smart devices, such as ultrafast switches, modulators, memories and sensors.

Domain structure and magnetic properties of epitaxial SrRuO sub 3 films grown on SrTiO sub 3 (100) substrates by ion beam sputtering

CERN Document Server

Oh, S H

2000-01-01

The domain structure of epitaxial SrRuO sub 3 thin films grown on SrTiO sub 3 (100) substrates by using ion beam sputtering has been investigated with transmission electron microscopy (TEM) and X-ray diffraction (XRD). The SrRuO sub 3 films grown in the present study revealed a unique cube-on-cube epitaxial relationship, i.e., (100) sub S sub R sub O ll (100) sub S sub T sub O , [010] sub S sub R sub O ll [101] sub S sub T sub O , prevailing with a cubic single-domain structure. The cubic SrRuO sub 3 thin films that were inherently with free from RuO sub 6 octahedron tilting exhibited higher resistivity with suppressed magnetic properties. The Curie temperature of the thin films was suppressed by 60 K from 160 K for the bulk specimen, and the saturation magnetic moment was reduced by a significant amount. The tetragonal distortion of the SrRuO sub 3 thin films due to coherent growth with the substrate seemed to result in a strong magnetic anisotropy.

Unravelling merging behaviors and electrostatic properties of CVD-grown monolayer MoS{sub 2} domains

Energy Technology Data Exchange (ETDEWEB)

Hao, Song; Yang, Bingchu, E-mail: bingchuyang@csu.edu.cn [College of Physics and Electronics, Institute of Super Microstructure and Ultrafast Process in Advanced Materials, Central South University, 605 South Lushan Road, Changsha 410012 (China); Hunan Key Laboratory for Super-Microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha 410012 (China); Gao, Yongli [College of Physics and Electronics, Institute of Super Microstructure and Ultrafast Process in Advanced Materials, Central South University, 605 South Lushan Road, Changsha 410012 (China); Hunan Key Laboratory for Super-Microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha 410012 (China); Department of Physics and Astronomy, University of Rochester, Rochester, New York 14534 (United States)

2016-08-28

The presence of grain boundaries is inevitable for chemical vapor deposition (CVD)-grown MoS{sub 2} domains owing to various merging behaviors, which greatly limits its potential applications in novel electronic and optoelectronic devices. It is therefore of great significance to unravel the merging behaviors of the synthesized polygon shape MoS{sub 2} domains. Here we provide systematic investigations of merging behaviors and electrostatic properties of CVD-grown polycrystalline MoS{sub 2} crystals by multiple means. Morphological results exhibit various polygon shape features, ascribed to polycrystalline crystals merged with triangle shape MoS{sub 2} single crystals. The thickness of triangle and polygon shape MoS{sub 2} crystals is identical manifested by Raman intensity and peak position mappings. Three merging behaviors are proposed to illustrate the formation mechanisms of observed various polygon shaped MoS{sub 2} crystals. The combined photoemission electron microscopy and kelvin probe force microscopy results reveal that the surface potential of perfect merged crystals is identical, which has an important implication for fabricating MoS{sub 2}-based devices.

Surface and interface states of Bi{sub 2}Se{sub 3} thin films investigated by optical second-harmonic generation and terahertz emission

Energy Technology Data Exchange (ETDEWEB)

Hamh, S. Y.; Park, S.-H.; Lee, J. S., E-mail: jsl@gist.ac.kr [Department of Physics and Photon Science, School of Physics and Chemistry, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Jerng, S.-K.; Jeon, J. H.; Chun, S. H. [Department of Physics and Graphene Research Institute, Sejong University, Seoul 143-747 (Korea, Republic of); Jeon, J. H.; Kahng, S. J. [Department of Physics, Korea University, Seoul 136-701 (Korea, Republic of); Yu, K.; Choi, E. J. [Department of Physics, University or Seoul, Seoul 130-743 (Korea, Republic of); Kim, S.; Choi, S.-H. [Department of Applied Physics, College of Applied Science, Kyung Hee University, Yongin 446-701 (Korea, Republic of); Bansal, N. [Department of Electrical and Computer Engineering, Rutgers, The state University of New Jersey, Piscataway, New Jersey 08854 (United States); Oh, S. [Department of Physics and Astronomy, Rutgers, The state University of New Jersey, Piscataway, New Jersey 08854 (United States); Park, Joonbum; Kho, Byung-Woo; Kim, Jun Sung [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

2016-02-01

We investigate the surface and interface states of Bi{sub 2}Se{sub 3} thin films by using the second-harmonic generation technique. Distinct from the surface of bulk crystals, the film surface and interface show the isotropic azimuth dependence of second-harmonic intensity, which is attributed to the formation of randomly oriented domains on the in-plane. Based on the nonlinear susceptibility deduced from the model fitting, we determine that the surface band bending induced in a space charge region occurs more strongly at the film interface facing the Al{sub 2}O{sub 3} substrate or capping layer compared with the interface facing the air. We demonstrate that distinct behavior of the terahertz electric field emitted from the samples can provide further information about the surface electronic state of Bi{sub 2}Se{sub 3}.

X-ray investigation of lateral hetero-structures of inversion domains in LiNbO{sub 3}, KTiOPO{sub 4} and KTiOAsO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Lyford, Thomas S. [Panalytical Research, The Sussex Innovation Centre, Falmer, Brighton, BN1 9SB (United Kingdom); Collins, Stephen P., E-mail: steve.collins@diamond.ac.uk [Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE (United Kingdom); Fewster, Paul F. [Panalytical Research, The Sussex Innovation Centre, Falmer, Brighton, BN1 9SB (United Kingdom); Thomas, Pamela A. [Department of Physics, University of Warwick, CV4 7AL (United Kingdom); Panalytical Research, The Sussex Innovation Centre, Falmer, Brighton, BN1 9SB (United Kingdom)

2015-05-01

Periodically-poled ferroelectric crystals are studied by observing their superlattice (grating) diffraction profiles with high-resolution X-ray diffraction. In order to successfully model the data, the effects of strain, and sample and beam coherence, must be taken into account. In this paper periodically domain-inverted (PDI) ferroelectric crystals are studied using high-resolution X-ray diffraction. Rocking curves and reciprocal-space maps of the principal symmetric Bragg reflections in LiNbO{sub 3} (LN) (Λ = 5 µm), KTiOPO{sub 4} (KTP) (Λ = 9 µm) and KTiOAsO{sub 4} (KTA) (Λ = 39 µm) are presented. For all the samples strong satellite reflections were observed as a consequence of the PDI structure. Analysis of the satellites showed that they were caused by a combination of coherent and incoherent scattering between the adjacent domains. Whilst the satellites contained phase information regarding the structure of the domain wall, this information could not be rigorously extracted without a priori knowledge of the twinning mechanism. Analysis of the profiles reveals strain distributions of Δd/d = 1.6 × 10{sup −4} and 2.0 × 10{sup −4} perpendicular to domain walls in KTP and LN samples, respectively, and lateral correlation lengths of 63 µm (KTP), 194 µm (KTA) and 10 µm (LN). The decay of crystal truncation rods in LN and KTP was found to support the occurrence of surface corrugations.

Critical dynamics and domain motion from permittivity of the electronic ferroelectric (TMTTF){sub 2}AsF{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Brazovskii, Serguei, E-mail: brazov@lptms.u-psud.fr [LPTMS, UMR8626, CNRS & University Paris-Sud, Bat. 100, Orsay F-91405 (France); International Institute of Physics, 59078-400 Natal, Rio Grande do Norte (Brazil); Monceau, Pierre [CNRS & University Grenoble Alpes, Institute NEEL, F-38042 Grenoble (France); Nad, Felix Ya.

2015-03-01

The quasi one-dimensional organic conductor (TMTTF){sub 2}AsF{sub 6} shows the charge ordering transition at T{sub CO}=101 K to a state of the ferroelectric Mott insulator which is still well conducting. We present and interpret the experimental data on the gigantic dielectric response in the vicinity of T{sub CO}, concentrating on the frequency dependence of the inverse 1/ε of the complex permittivity ε=ε′+iε′′. Surprisingly for a ferroelectric, we could closely approach the 2nd order phase transition and to deeply reach the critical dynamics of the polarization. We could analyze the critical slowing-down when approaching T{sub CO} from both sides and to extract the anomalous power law for the frequency dependence of the order parameter viscosity. Moreover, below T{sub CO} we could extract a sharp absorption feature coming from a motion of domain walls which shows up at a frequency well below the relaxation rate.

Ionic Liquid Gating Control of RKKY Interaction in FeCoB/Ru/FeCoB and (Pt/Co)<sub>2sub>/Ru/(Co/Pt)>2sub> Multilayers.

Energy Technology Data Exchange (ETDEWEB)

Yang, Qu; Wang, Lei; Zhou, Ziyao; Wang, Liqian; Zhang, Yijun; Zhao, Shishun; Dong, Guohua; Cheng, Yuxin; Min, Tai; Hu, Zhongqiang; Chen, Wei; Xia, Ke; Liu, Ming

2018-03-07

To overcome the fundamental challenge of the weak natural response of antiferromagnetic materials under a magnetic field, voltage manipulation of antiferromagnetic interaction is developed to realize ultrafast, high-density, and power efficient antiferromagnetic spintronics. Here, we report a low voltage modulation of Ruderman–Kittel–Kasuya–Yosida (RKKY) interaction via ionic liquid gating in synthetic antiferromagnetic multilayers of FeCoB/Ru/FeCoB and (Pt/Co)<sub>2sub>/Ru/(Co/Pt)>2sub>. At room temperature, the distinct voltage control of transition between antiferromagnetic and ferromagnetic ordering is realized and up to 80% of perpendicular magnetic moments manage to switch with a small-applied voltage bias of 2.5 V. We related this ionic liquid gating-induced RKKY interaction modification to the disturbance of itinerant electrons inside synthetic antiferromagnetic heterostructure and the corresponding change of its Fermi level. Voltage tuning of RKKY interaction may enable the next generation of switchable spintronics between antiferromagnetic and ferromagnetic modes with both fundamental and practical perspectives.

Domain wall motion and electromechanical strain in lead-free piezoelectrics: Insight from the model system (1 − x)Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}–x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} using in situ high-energy X-ray diffraction during application of electric fields

Energy Technology Data Exchange (ETDEWEB)

Tutuncu, Goknur [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Li, Binzhi [Department of Chemical Engineering and Materials Science, University of California, Davis, Davis, California 95616 (United States); Bowman, Keith [Illinois Institute of Technology, Armour College of Engineering, Chicago, Illinois 60616 (United States); School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Jones, Jacob L., E-mail: JacobJones@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

2014-04-14

The piezoelectric compositions (1 − x)Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}–x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} (BZT-xBCT) span a model lead-free morphotropic phase boundary (MPB) between room temperature rhombohedral and tetragonal phases at approximately x = 0.5. In the present work, in situ X-ray diffraction measurements during electric field application are used to elucidate the origin of electromechanical strain in several compositions spanning the tetragonal compositional range 0.6 ≤ x ≤ 0.9. As BCT concentration decreases towards the MPB, the tetragonal distortion (given by c/a-1) decreases concomitantly with an increase in 90° domain wall motion. The increase in observed macroscopic strain is predominantly attributed to the increased contribution from 90° domain wall motion. The results demonstrate that domain wall motion is a significant factor in achieving high strain and piezoelectric coefficients in lead-free polycrystalline piezoelectrics.

A New Metal Binding Domain Involved in Cadmium, Cobalt and Zinc Transport

Energy Technology Data Exchange (ETDEWEB)

Smith, Aaron T. [Northwestern Univ., Evanston, IL (United States); Barupala, Dulmini [Wayne State Univ., Detroit, MI (United States); Stemmler, Timothy L. [Wayne State Univ., Detroit, MI (United States); Rosenzweig, Amy C. [Northwestern Univ., Evanston, IL (United States)

2015-07-20

In the P1B-ATPases, which couple cation transport across membranes to ATP hydrolysis, are central to metal homeostasis in all organisms. An important feature of P1B-ATPases is the presence of soluble metal binding domains (MBDs) that regulate transport activity. Only one type of MBD has been characterized extensively, but bioinformatics analyses indicate that a diversity of MBDs may exist in nature. Here we report the biochemical, structural and functional characterization of a new MBD from the Cupriavidus metallidurans P<sub>1B-4sub>-ATPase CzcP (CzcP MBD). The CzcP MBD binds two Cd²⁺, Co²⁺ or Zn²⁺ ions in distinct and unique sites and adopts an unexpected fold consisting of two fused ferredoxin-like domains. Both in vitro and in vivo activity assays using full-length CzcP, truncated CzcP and several variants indicate a regulatory role for the MBD and distinct functions for the two metal binding sites. Moreover, these findings elucidate a previously unknown MBD and suggest new regulatory mechanisms for metal transport by P<sub>1Bsub>-ATPases.

A new polar symmetry of huebnerite (MnWO{sub 4}) with ferrodistortive domains

Energy Technology Data Exchange (ETDEWEB)

Park, S.H., E-mail: sohyun.park@lmu.de [Sektion Kristallographie, Department für Geo-und Umweltwissenschaften, Ludwig-Maximilians-Universität München, Theresienstraße 41, 80333 München (Germany); Mihailova, B. [Mineralogisch-Petrographisches Institut, Universität Hamburg, Grindelallee 48, 20146 Hamburg (Germany); Pedersen, B. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München, Lichtenbergstraße 1, 85748 Garching (Germany); Paulmann, C. [Mineralogisch-Petrographisches Institut, Universität Hamburg, Grindelallee 48, 20146 Hamburg (Germany); HASYLAB, DESY, Notkestr. 85, 22603 Hamburg (Germany); Behal, D. [Sektion Kristallographie, Department für Geo-und Umweltwissenschaften, Ludwig-Maximilians-Universität München, Theresienstraße 41, 80333 München (Germany); Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München, Lichtenbergstraße 1, 85748 Garching (Germany); Gattermann, U. [Sektion Kristallographie, Department für Geo-und Umweltwissenschaften, Ludwig-Maximilians-Universität München, Theresienstraße 41, 80333 München (Germany); Hochleitner, R. [Mineralogische Staatssammlung München, Theresienstrasse 41, 80333 Munich (Germany)

2015-11-15

Large-size single-crystal samples of huebnerite natural multiferroic MnWO{sub 4} were analyzed by neutron and synchrotron X-ray single-crystal diffraction as well as by polarized Raman spectroscopy. Both neutron and X-ray diffraction analyzes reveal polar space-group symmetry P2 for the nuclear structure of huebnerite via the detection of weak reflections h0l (l=odd) forbidden for the gliding plane c. Renninger scans of the reflection 301 on the neutron single-crystal diffractometer RESI (FRM-II) could confirm the absence of the gliding plane c in both para- and antiferromagnetic states of huebnerite. The symmetry breaking could be explained by structure analyzes with neutron single crystal diffraction data at 293 K revealing that two Mn atoms in P2 are displaced independently along the b axis from their equilibrium position at a polar point site, C{sub 2} in P2/c. Micro X-ray diffraction and Raman-scattering mapping reveal a ferrodistortive domain texture in the room-temperature paramagnetic state of huebnerite, which is attributed to P2 domain formation through a proper ∼180° rotation about the reciprocal-space axis c*. - Graphical abstract: Schematic presentation of polar atomic shifts (arrows) in P2 from the respective equivalent sites (spheres) in P2/c at the boundary of two 180°-in-plane micro twins. - Highlights: • Neutron and X-ray diffraction analyzes reveal the polar symmetry P2 for MnWO{sub 4}. • Raman mapping shows ferrodistortive domains in its RT paramagnetic state. • These observations are explained by the hidden polar site C{sub 2} for Mn atoms.

Post-deposition control of ferroelastic stripe domains and internal electric field by thermal treatment

Energy Technology Data Exchange (ETDEWEB)

Feigl, L.; Iwanowska, M.; Sandu, C. S.; Setter, N. [Ceramics Laboratory, EPFL-Swiss Federal Institute of Technology, Lausanne, CH-1015 Switzerland (Switzerland); Janolin, P.-E. [Laboratoire Structures, Propriétés et Modélisation des Solides, UMR CNRS-École Centrale Paris, Grande Voie des Vignes, 92295 Châtenay-Malabry Cedex (France); Yamada, T. [Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya 464-8603 (Japan); PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan)

2015-01-19

The dependence of the formation of ferroelastic stripe domain patterns on the thermal history is investigated by detailed piezoresponse force microscopy and X-ray diffraction experiments after and during annealing of tensile strained tetragonal Pb(Ti,Zr)O{sub 3} epitaxial thin films on DyScO{sub 3} substrates. In particular, the ferroelastic pattern is reversibly interchanged between a cross-hatched and a stripe domain pattern if the films are cooled at different rates after annealing above the formation temperature of a-domains. Different types of 180° and non-180° patterns can be created, depending on the thermal treatment. The changes in the 180° domain structure and lattice parameters are attributed to a change of oxygen vacancy concentration, which results in a modification of the internal electric field and unit cell size, causing also a shift of T{sub C}. Thermal treatment is done on rhombohedral La:BiFeO{sub 3} thin films as well. It is observed that also in these films, appropriate heat treatment modifies the domain pattern and films with a stripe domain pattern can be created, confirming the general validity of the developed model.

Protein Sub-Nuclear Localization Prediction Using SVM and Pfam Domain Information

Science.gov (United States)

Kumar, Ravindra; Jain, Sohni; Kumari, Bandana; Kumar, Manish

2014-01-01

The nucleus is the largest and the highly organized organelle of eukaryotic cells. Within nucleus exist a number of pseudo-compartments, which are not separated by any membrane, yet each of them contains only a specific set of proteins. Understanding protein sub-nuclear localization can hence be an important step towards understanding biological functions of the nucleus. Here we have described a method, SubNucPred developed by us for predicting the sub-nuclear localization of proteins. This method predicts protein localization for 10 different sub-nuclear locations sequentially by combining presence or absence of unique Pfam domain and amino acid composition based SVM model. The prediction accuracy during leave-one-out cross-validation for centromeric proteins was 85.05%, for chromosomal proteins 76.85%, for nuclear speckle proteins 81.27%, for nucleolar proteins 81.79%, for nuclear envelope proteins 79.37%, for nuclear matrix proteins 77.78%, for nucleoplasm proteins 76.98%, for nuclear pore complex proteins 88.89%, for PML body proteins 75.40% and for telomeric proteins it was 83.33%. Comparison with other reported methods showed that SubNucPred performs better than existing methods. A web-server for predicting protein sub-nuclear localization named SubNucPred has been established at http://14.139.227.92/mkumar/subnucpred/. Standalone version of SubNucPred can also be downloaded from the web-server. PMID:24897370

Water adsorption induced in-plane domain switching on BaTiO{sub 3} surface

Energy Technology Data Exchange (ETDEWEB)

Li, X.; Bai, Y.; Su, Y. J., E-mail: yjsu@ustb.edu.cn [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), University of Science and Technology Beijing, Beijing 100083 (China); Wang, B. C. [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), University of Science and Technology Beijing, Beijing 100083 (China); Multiscale Materials Modelling group, Department of Materials and Engineering, Royal Institute of Technology, SE-10044 Stockholm (Sweden)

2015-09-07

In this study, the influences of the adsorption of water molecules on the changes in the atomic and electric structures of BaTiO{sub 3} surface were investigated using ab initio calculation. Water molecules are molecularly and dissociatively adsorbed on the BaTiO{sub 3} surface, which makes electrons transfer from water molecules to the BaTiO{sub 3} surface. The redistribution of electrons in the BaTiO{sub 3} surface layers weakens the Ba-O interactions and strengthens the Ti-O interactions, so that the Ti atom shifts in TiO{sub 2} plane, i.e., an in-plane domain switching. The adsorption of water molecules on BaTiO{sub 3} surfaces also results in a reduction in the surface rumpling.

Domain-Specific Control of Selective Attention

Science.gov (United States)

Lin, Szu-Hung; Yeh, Yei-Yu

2014-01-01

Previous research has shown that loading information on working memory affects selective attention. However, whether the load effect on selective attention is domain-general or domain-specific remains unresolved. The domain-general effect refers to the findings that load in one content (e.g. phonological) domain in working memory influences processing in another content (e.g., visuospatial) domain. Attentional control supervises selection regardless of information domain. The domain-specific effect refers to the constraint of influence only when maintenance and processing operate in the same domain. Selective attention operates in a specific content domain. This study is designed to resolve this controversy. Across three experiments, we manipulated the type of representation maintained in working memory and the type of representation upon which the participants must exert control to resolve conflict and select a target into the focus of attention. In Experiments 1a and 1b, participants maintained digits and nonverbalized objects, respectively, in working memory while selecting a target in a letter array. In Experiment 2, we presented auditory digits with a letter flanker task to exclude the involvement of resource competition within the same input modality. In Experiments 3a and 3b, we replaced the letter flanker task with an object flanker task while manipulating the memory load on object and digit representation, respectively. The results consistently showed that memory load modulated distractibility only when the stimuli of the two tasks were represented in the same domain. The magnitude of distractor interference was larger under high load than under low load, reflecting a lower efficacy of information prioritization. When the stimuli of the two tasks were represented in different domains, memory load did not modulate distractibility. Control of processing priority in selective attention demands domain-specific resources. PMID:24866977

Continuous Magnetoelectric Control in Multiferroic DyMnO3 Films with Twin-like Domains

Science.gov (United States)

Lu, Chengliang; Deniz, Hakan; Li, Xiang; Liu, Jun-Ming; Cheong, Sang-Wook

2016-02-01

The magnetic control of ferroelectric polarization is currently a central topic in the multiferroic researches, owing to the related gigantic magnetoelectric coupling and fascinating physics. Although a bunch of novel magnetoelectric effect have been discovered in multiferroics of magnetic origin, the manipulation of polarization was found to be fundamentally determined by the microscopic origin in a certain multiferroic phase, hindering the development of unusual magnetoelectric control. Here, we report emergent magnetoelectric control in DyMnO3/Nb:SrTiO3 (001) films showing twin-like domain structure. Our results demonstrate interesting magnetically induced partial switch of polarization due to the coexistence of polarizations along both the a-axis and c-axis enabled by the twin-like domain structure in DyMnO3 films, despite the polarization-switch was conventionally believed to be a one-step event in the bulk counterpart. Moreover, a continuous and periodic control of macroscopic polarization by an in-plane rotating magnetic field is evidenced in the thin films. This distinctive magnetic manipulation of polarization is the consequence of the cooperative action of the twin-like domains and the dual magnetic origin of polarization, which promises additional applications using the magnetic control of ferroelectricity.

Magnetostatic coupling of 90{sup 0} domain walls in Fe{sub 19}Ni{sub 81}/Cu/Co trilayers

Energy Technology Data Exchange (ETDEWEB)

Kurde, J; Miguel, J; Kuch, W [Institut fuer Experimentalphysik, Freie Universitaet Berlin, Arnimallee 14, 14195 Berlin-Dahlem (Germany); Bayer, D; Aeschlimann, M [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern (Germany); Sanchez-Barriga, J; Kronast, F; Duerr, H A, E-mail: julia.kurde@fu-berlin.de [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, 12489 Berlin (Germany)

2011-03-15

The magnetic interlayer coupling of Fe{sub 19}Ni{sub 81}/Cu/Co trilayered microstructures has been studied by means of x-ray magnetic circular dichroism in combination with photoelectron emission microscopy (XMCD-PEEM). We find that a parallel coupling between magnetic domains coexists with a non-parallel coupling between magnetic domain walls (DWs) of each ferromagnetic layer. We attribute the non-parallel coupling of the two magnetic layers to local magnetic stray fields arising at DWs in the magnetically harder Co layer. In the magnetically softer FeNi layer, non-ordinary DWs, such as 270{sup 0} and 90{sup 0} DWs with overshoot of the magnetization either inwards or outwards relative to the turning direction of the Co magnetization, are identified. Micromagnetic simulations reveal that in the absence of magnetic anisotropy, both types of overshooting DWs are energetically equivalent. However, if a uniaxial in-plane anisotropy is present, the relative orientation of the DWs with respect to the anisotropy axis determines which of these DWs is energetically favorable.

Clustering of Tissue-Specific Sub-TADs Accompanies the Regulation of HoxA Genes in Developing Limbs

Science.gov (United States)

Berlivet, Soizik; Paquette, Denis; Dumouchel, Annie; Langlais, David; Dostie, Josée; Kmita, Marie

2013-01-01

HoxA genes exhibit central roles during development and causal mutations have been found in several human syndromes including limb malformation. Despite their importance, information on how these genes are regulated is lacking. Here, we report on the first identification of bona fide transcriptional enhancers controlling HoxA genes in developing limbs and show that these enhancers are grouped into distinct topological domains at the sub-megabase scale (sub-TADs). We provide evidence that target genes and regulatory elements physically interact with each other through contacts between sub-TADs rather than by the formation of discreet “DNA loops”. Interestingly, there is no obvious relationship between the functional domains of the enhancers within the limb and how they are partitioned among the topological domains, suggesting that sub-TAD formation does not rely on enhancer activity. Moreover, we show that suppressing the transcriptional activity of enhancers does not abrogate their contacts with HoxA genes. Based on these data, we propose a model whereby chromatin architecture defines the functional landscapes of enhancers. From an evolutionary standpoint, our data points to the convergent evolution of HoxA and HoxD regulation in the fin-to-limb transition, one of the major morphological innovations in vertebrates. PMID:24385922

Clustering of tissue-specific sub-TADs accompanies the regulation of HoxA genes in developing limbs.

Directory of Open Access Journals (Sweden)

Soizik Berlivet

Full Text Available HoxA genes exhibit central roles during development and causal mutations have been found in several human syndromes including limb malformation. Despite their importance, information on how these genes are regulated is lacking. Here, we report on the first identification of bona fide transcriptional enhancers controlling HoxA genes in developing limbs and show that these enhancers are grouped into distinct topological domains at the sub-megabase scale (sub-TADs. We provide evidence that target genes and regulatory elements physically interact with each other through contacts between sub-TADs rather than by the formation of discreet "DNA loops". Interestingly, there is no obvious relationship between the functional domains of the enhancers within the limb and how they are partitioned among the topological domains, suggesting that sub-TAD formation does not rely on enhancer activity. Moreover, we show that suppressing the transcriptional activity of enhancers does not abrogate their contacts with HoxA genes. Based on these data, we propose a model whereby chromatin architecture defines the functional landscapes of enhancers. From an evolutionary standpoint, our data points to the convergent evolution of HoxA and HoxD regulation in the fin-to-limb transition, one of the major morphological innovations in vertebrates.

Heart rate variability is associated with psychosocial stress in distinct social domains.

Science.gov (United States)

Lischke, Alexander; Jacksteit, Robert; Mau-Moeller, Anett; Pahnke, Rike; Hamm, Alfons O; Weippert, Matthias

2018-03-01

Psychosocial stress is associated with substantial morbidity and mortality. Accordingly, there is a growing interest in biomarkers that indicate whether individuals show adaptive (i.e., stress-buffering and health-promoting) or maladaptive (i.e., stress-escalating and health-impairing) stress reactions in social contexts. As heart rate variability (HRV) has been suggested to be a biomarker of adaptive behavior during social encounters, it may be possible that inter-individual differences in HRV are associated with inter-individual differences regarding stress in distinct social domains. To test this hypothesis, resting state HRV and psychosocial stress was assessed in 83 healthy community-dwelling individuals (age: 18-35years). HRV was derived from heart rate recordings during spontaneous and instructed breathing to assess the robustness of possible associations between inter-individual differences in HRV and inter-individual differences in psychosocial stress. Psychosocial stress was determined with a self-report questionnaire assessing stress in distinct social domains. A series of categorical and dimensional analyses revealed an association between inter-individual differences in HRV and inter-individual differences in psychosocial stress: Individuals with high HRV reported less stress in social life, but not in family life, work life or everyday life, than individuals with low HRV. On basis of these findings, it may be assumed that individuals with high HRV experience less psychosocial stress than individuals with low HRV. Although such an assumption needs to be corroborated by further findings, it seems to be consistent with previous findings showing that individuals with high HRV suffer less from stress and stress-related disorders than individuals with low HRV. Copyright © 2018 Elsevier Inc. All rights reserved.

Distinct Domains of CheA Confer Unique Functions in Chemotaxis and Cell Length in Azospirillum brasilense Sp7.

Science.gov (United States)

Gullett, Jessica M; Bible, Amber; Alexandre, Gladys

2017-07-01

Chemotaxis is the movement of cells in response to gradients of diverse chemical cues. Motile bacteria utilize a conserved chemotaxis signal transduction system to bias their motility and navigate through a gradient. A central regulator of chemotaxis is the histidine kinase CheA. This cytoplasmic protein interacts with membrane-bound receptors, which assemble into large polar arrays, to propagate the signal. In the alphaproteobacterium Azospirillum brasilense , Che1 controls transient increases in swimming speed during chemotaxis, but it also biases the cell length at division. However, the exact underlying molecular mechanisms for Che1-dependent control of multiple cellular behaviors are not known. Here, we identify specific domains of the CheA1 histidine kinase implicated in modulating each of these functions. We show that CheA1 is produced in two isoforms: a membrane-anchored isoform produced as a fusion with a conserved seven-transmembrane domain of unknown function (TMX) at the N terminus and a soluble isoform similar to prototypical CheA. Site-directed and deletion mutagenesis combined with behavioral assays confirm the role of CheA1 in chemotaxis and implicate the TMX domain in mediating changes in cell length. Fluorescence microscopy further reveals that the membrane-anchored isoform is distributed around the cell surface while the soluble isoform localizes at the cell poles. Together, the data provide a mechanism for the role of Che1 in controlling multiple unrelated cellular behaviors via acquisition of a new domain in CheA1 and production of distinct functional isoforms. IMPORTANCE Chemotaxis provides a significant competitive advantage to bacteria in the environment, and this function has been transferred laterally multiple times, with evidence of functional divergence in different genomic contexts. The molecular principles that underlie functional diversification of chemotaxis in various genomic contexts are unknown. Here, we provide a molecular

High-temperature phase transitions and domain structures of KLiSO{sub 4}. Studied by polarisation-optics, X-ray topography and liquid-crystal surface decoration

Energy Technology Data Exchange (ETDEWEB)

Scherf, Christian; Chung, Su Jin; Hahn, Theo; Klapper, Helmut [RWTH Aachen Univ. (Germany). Inst. fuer Kristallographie; Ivanov, Nicolay R. [Russian Academy of Sciences, Moscow (Russian Federation). Shubnikov Inst. of Crystallography

2017-07-01

The transitions between the room temperature phase III (space group P6{sub 3}) and the two high-temperature phases II (Pcmn) and I (P6{sub 3}/mmc) of KLiSO{sub 4} and the domain structures generated by them were investigated by high-temperature polarisation optics (birefringence) and room-temperature X-ray topography, optical activity and nematic-liquid-crystal (NLC) surface decoration. The transition from the polar hexagonal phase III into the centrosymmetric orthorhombic phase II at 708 K leads, due to the loss of the trigonal axis and the radial temperature gradient of the optical heating chamber used, to a roughly hexagonal arrangement of three sets of thin orthorhombic {110} lamelleae with angles of 60 (120 ) between them. The associated twin law ''reflection m{110}{sub orth}'' corresponds to the frequent growth twin m{10 anti 10}{sub hex} of phase III. The domains are easily ferroelastically switched. Upon further heating above 949 K into phase I (P6{sub 3}/mmc) all domains vanish. Upon cooling back into phase II the three domain states related by 60 (120 ) reflections m{110}{sub orth} re-appear, however (due to the higher thermal agitation at 949 K) with a completely different domain structure consisting of many small, irregularly arranged {110}{sub orth} domains. Particular attention is paid to the domain structure of the hexagonal room temperature phase III generated during the re-transition from the orthorhombic phase II. Curiously, from the expected three twin laws inversion anti 1, rotation 2 perpendicular to [001]{sub hex} and reflection m{10 anti 10}{sub hex} only the latter, which corresponds to the frequent growth twinning, has been found. Finally a short treatise of the structural relations of the KLiSO{sub 4} high-temperature polymorphs is given.

Structure of the effector-binding domain of the arabinose repressor AraR from Bacillus subtilis

Energy Technology Data Exchange (ETDEWEB)

Procházková, Kateřina; Čermáková, Kateřina [Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6 (Czech Republic); Pachl, Petr; Sieglová, Irena [Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6 (Czech Republic); Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4 (Czech Republic); Fábry, Milan [Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4 (Czech Republic); Otwinowski, Zbyszek [UT Southwestern Medical Center, Dallas, Texas (United States); Řezáčová, Pavlína, E-mail: rezacova@uochb.cas.cz [Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6 (Czech Republic); Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4 (Czech Republic)

2012-02-01

The crystal structure of the effector-binding domain of the transcriptional repressor AraR from B. subtilis in complex with the effector molecule (l-arabinose) was determined at 2.2 Å resolution. A detailed analysis of the crystal identified a dimer organization that is distinctive from that of other members of the GalR/LacI family. In Bacillus subtilis, the arabinose repressor AraR negatively controls the expression of genes in the metabolic pathway of arabinose-containing polysaccharides. The protein is composed of two domains of different phylogenetic origin and function: an N-terminal DNA-binding domain belonging to the GntR family and a C-terminal effector-binding domain that shows similarity to members of the GalR/LacI family. The crystal structure of the C-terminal effector-binding domain of AraR in complex with the effector l-arabinose has been determined at 2.2 Å resolution. The l-arabinose binding affinity was characterized by isothermal titration calorimetry and differential scanning fluorimetry; the K{sub d} value was 8.4 ± 0.4 µM. The effect of l-arabinose on the protein oligomeric state was investigated in solution and detailed analysis of the crystal identified a dimer organization which is distinctive from that of other members of the GalR/LacI family.

Distinct domains within the NITROGEN LIMITATION ADAPTATION protein mediate its subcellular localization and function in the nitrate-dependent phosphate homeostasis pathway

Science.gov (United States)

The NITROGEN LIMITATION ADAPTATION (NLA) protein is a RING-type E3 ubiquitin ligase that plays an essential role in the regulation of nitrogen and phosphate homeostasis. NLA is localized to two distinct subcellular sites, the plasma membrane and nucleus, and contains four distinct domains: i) a RING...

Identification of inversion domains in KTiOPO{sub 4}via resonant X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Fabrizi, Federica, E-mail: federica.fabrizi@diamond.ac.uk [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE (United Kingdom); Thomas, Pamela A. [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom); Nisbet, Gareth; Collins, Stephen P. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE (United Kingdom)

2015-05-14

The identification and high-resolution mapping of the absolute crystallographic structure in multi-domain ferroelectric KTiOPO{sub 4} is achieved through a novel synchrotron X-ray diffraction method. On a single Bragg reflection, the intensity ratio in resonant diffraction below and above the Ti absorption K edge demonstrates a domain contrast up to a factor of ∼270, thus implementing a non-contact, non-destructive imaging technique with micrometre spatial resolution, applicable to samples of arbitrarily large dimensions. A novel method is presented for the identification of the absolute crystallographic structure in multi-domain polar materials such as ferroelectric KTiOPO{sub 4}. Resonant (or ‘anomalous’) X-ray diffraction spectra collected across the absorption K edge of Ti (4.966 keV) on a single Bragg reflection demonstrate a huge intensity ratio above and below the edge, providing a polar domain contrast of ∼270. This allows one to map the spatial domain distribution in a periodically inverted sample, with a resolution of ∼1 µm achieved with a microfocused beam. This non-contact, non-destructive technique is well suited for samples of large dimensions (in contrast with traditional resonant X-ray methods based on diffraction from Friedel pairs), and its potential is particularly relevant in the context of physical phenomena connected with an absence of inversion symmetry, which require characterization of the underlying absolute atomic structure (such as in the case of magnetoelectric coupling and multiferroics)

Human-computer interface incorporating personal and application domains

Science.gov (United States)

Anderson, Thomas G [Albuquerque, NM

2011-03-29

The present invention provides a human-computer interface. The interface includes provision of an application domain, for example corresponding to a three-dimensional application. The user is allowed to navigate and interact with the application domain. The interface also includes a personal domain, offering the user controls and interaction distinct from the application domain. The separation into two domains allows the most suitable interface methods in each: for example, three-dimensional navigation in the application domain, and two- or three-dimensional controls in the personal domain. Transitions between the application domain and the personal domain are under control of the user, and the transition method is substantially independent of the navigation in the application domain. For example, the user can fly through a three-dimensional application domain, and always move to the personal domain by moving a cursor near one extreme of the display.

Expression, purification, crystallization and preliminary X-ray diffraction analysis of the VP8* sialic acid-binding domain of porcine rotavirus strain OSU

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yang-De, E-mail: zhangyd1960@yahoo.com.cn; Li, Hao [National Hepatobiliary and Enteric Surgery Research Center of The Ministry of Health, Xiangya Hospital, Central South University, Hunan Province (China); Liu, Hui; Pan, Yi-Feng [Biochemistry Laboratory, Institution of Biomedical Engineering, Central South University, Hunan Province (China); National Hepatobiliary and Enteric Surgery Research Center of The Ministry of Health, Xiangya Hospital, Central South University, Hunan Province (China)

2007-02-01

Porcine rotavirus strain OSU VP8* domain has been expressed, purified and crystallized. X-ray diffraction data from different crystal forms of the VP8* domain have been collected to 2.65 and 2.2 Å resolution, respectively. The rotavirus outer capsid spike protein VP4 is utilized in the process of rotavirus attachment to and membrane penetration of host cells. VP4 is cleaved by trypsin into two domains: VP8* and VP5*. The VP8* domain is implicated in initial interaction with sialic acid-containing cell-surface carbohydrates and triggers subsequent virus invasion. The VP8* domain from porcine OSU rotavirus was cloned and expressed in Escherichia coli. Different crystal forms (orthorhombic P2{sub 1}2{sub 1}2{sub 1} and tetragonal P4{sub 1}2{sub 1}2) were harvested from two distinct crystallization conditions. Diffraction data have been collected to 2.65 and 2.2 Å resolution and the VP8*{sub 65–224} structure was determined by molecular replacement.

Neutron diffraction study of the formation kinetics of ordered antiphase domains in titanium carbohydride TiC{sub x}H{sub y}

Energy Technology Data Exchange (ETDEWEB)

Khidirov, I., E-mail: khidirov@inp.uz [Uzbekistan Academy of Sciences, Institute of Nuclear Physics (Uzbekistan)

2015-09-15

The kinetics of formation and growth of ordered antiphase domains (APDs) in titanium carbohydride TiC{sub 0.50}H{sub 0.21} has been investigated by neutron diffraction. A model of ordered APDs is proposed. It is established that the pronounced ordering of interstitial atoms and APDs begin at 450°C. It is shown that the period of ordered APDs (P ≈ 10–12) is independent of the exposure time at a constant temperature. It is found that the temperature of ordered APDs, T{sub OAPD}, increases nonlinearly with an increase in the carbon concentration in the range 0.50 ≤ C/Ti ≤ 0.70. The formation temperature of ordered APDs is found to correlate with the concentration dependence of the order–disorder transition temperature and be 0.60 of the order–disorder transition temperature: T{sub APD} = 0.60Τ{sub C}.

Properties measurements of (U{sub 0.7}Pu{sub 0.3})O{sub 2-x} in PO{sub 2}-controlled atmosphere

Energy Technology Data Exchange (ETDEWEB)

Kato, M.; Murakami, T.; Sunaoshi, T. [Advanced Nuclear System Research and Development Directorate, Japan Atomic Energy Agency, Muramatsu Tokai-mura Ibaraki, 319-1194 (Japan); Nelson, A.T.; McClellan, K.J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2013-07-01

The investigation of physical properties of uranium and plutonium mixed oxide (MOX) fuels is important for the development of fast reactor fuels. It is well known that MOX is a nonstoichiometric oxide, and the physical properties change drastically with the Oxygen-to-Metal (O/M) ratio. A control technique for O/M ratio was established for measurements of high temperature properties of uranium and plutonium mixed oxide fuels. Sintering behavior, thermal expansion and O/M change of (U{sub 0.7}Pu{sub 0.3})O{sub 2.00} and (U{sub 0.7}Pu{sub 0.3})O{sub 1.99} were investigated in PO{sub 2}-controlled atmosphere which was controlled by H{sub 2}/H{sub 2}O gas system. Sintering behavior changed drastically with O/M ratio, and shrinkage of (U{sub 0.7}Pu{sub 0.3})O{sub 2.00} was faster and more advanced at lower temperatures as compared with (U{sub 0.7}Pu{sub 0.3})O{sub 1.99}. Thermal expansion was observed to be slightly increased with decreasing O/M ratio. (authors)

Sub-circuits of a gene regulatory network control a developmental epithelial-mesenchymal transition.

Science.gov (United States)

Saunders, Lindsay R; McClay, David R

2014-04-01

Epithelial-mesenchymal transition (EMT) is a fundamental cell state change that transforms epithelial to mesenchymal cells during embryonic development, adult tissue repair and cancer metastasis. EMT includes a complex series of intermediate cell state changes including remodeling of the basement membrane, apical constriction, epithelial de-adhesion, directed motility, loss of apical-basal polarity, and acquisition of mesenchymal adhesion and polarity. Transcriptional regulatory state changes must ultimately coordinate the timing and execution of these cell biological processes. A well-characterized gene regulatory network (GRN) in the sea urchin embryo was used to identify the transcription factors that control five distinct cell changes during EMT. Single transcription factors were perturbed and the consequences followed with in vivo time-lapse imaging or immunostaining assays. The data show that five different sub-circuits of the GRN control five distinct cell biological activities, each part of the complex EMT process. Thirteen transcription factors (TFs) expressed specifically in pre-EMT cells were required for EMT. Three TFs highest in the GRN specified and activated EMT (alx1, ets1, tbr) and the 10 TFs downstream of those (tel, erg, hex, tgif, snail, twist, foxn2/3, dri, foxb, foxo) were also required for EMT. No single TF functioned in all five sub-circuits, indicating that there is no EMT master regulator. Instead, the resulting sub-circuit topologies suggest EMT requires multiple simultaneous regulatory mechanisms: forward cascades, parallel inputs and positive-feedback lock downs. The interconnected and overlapping nature of the sub-circuits provides one explanation for the seamless orchestration by the embryo of cell state changes leading to successful EMT.

Integrated dry NO{sub x}/SO{sub 2} emissions control system performance summary

Energy Technology Data Exchange (ETDEWEB)

Hunt, T. [Public Service Company of Colorado, Denver, CO (United States); Muzio, L.J.; Smith, R. [Fossil Energy Research Corp., Laguna Hills, CA (United States); Jones, D. [NOELL, Inc., Long Beach, CA (United States); Hebb, J.L. [Dept. of Energy, Pittsburgh, PA (United States); Stallings, J. [Electric Power Research Inst., Palo Alto, CA (United States)

1997-12-31

The Integrated Dry NO{sub x}/SO{sub 2} Emissions Control System was installed at Public Service Company of Colorado`s Arapahoe 4 generating station in 1992 in cooperation with the US Department of Energy (DOE) and the Electric Power Research Institute (EPRI). This full-scale 100 MWe demonstration combines low-NO{sub x} burners, overfire, air, and selective non-catalytic reduction (SNCR) for NO{sub x} control and dry sorbent injection (DSI) with or without humidification for SO{sub 2} control. Operation and testing of the Integrated Dry NO{sub x}/SO{sub 2} Emissions Control System began in August 1992 and will continue through 1996. Results of the NO{sub x} control technologies show that the original system goal of 70% NO{sub x} removal has been easily met and the combustion and SNCR systems can achieve NO{sub x} removals of up to 80% at full load. Duct injection of commercial calcium hydroxide has achieved a maximum SO{sub 2} removal of nearly 40% while humidifying the flue gas to a 20 F approach to saturation. Sodium-based dry sorbent injection has provided SO{sub 2} removal of over 70% without the occurrence of a visible NO{sub 2} plume. Recent test work has improved SNCR performance at low loads and has demonstrated that combined dry sodium injection and SNCR yields both lower NO{sub 2} levels and NH{sub 3} slip than either technology alone.

Bicontinuous structured liquids with sub-micrometre domains using nanoparticle surfactants

Science.gov (United States)

Huang, Caili; Forth, Joe; Wang, Weiyu; Hong, Kunlun; Smith, Gregory S.; Helms, Brett A.; Russell, Thomas P.

2017-11-01

Bicontinuous jammed emulsions (or bijels) are tortuous, interconnected structures of two immiscible liquids, kinetically trapped by colloidal particles that are irreversibly bound to the oil-water interface. A wealth of applications has been proposed for bijels in catalysis, energy storage and molecular encapsulation, but large domain sizes (on the order of 5 µm or larger) and difficulty in fabrication pose major barriers to their use. Here, we show that bijels with sub-micrometre domains can be formed via homogenization, rather than spinodal decomposition. We achieve this by using nanoparticle surfactants: polymers and nanoparticles of complementary functionality (for example, ion-pairing) that bind to one another at the oil-water interface. This allows the stabilization of the bijel far from the demixing point of the liquids, with interfacial tensions on the order of 20 mN m-1. Furthermore, our strategy is extremely versatile, as solvent, nanoparticle and ligand can all be varied.

Facilitating Inter-Domain Synergies in Ambient Assisted Living Environments.

Science.gov (United States)

Schwartze, Jonas; Schrom, Harald; Wolf, Klaus-Hendrik; Marschollek, Michael

2016-01-01

Current Ambient Assisted Living (AAL) environments lack integration of sensors and actuators of other sub-domains. Creating technical and organizational integration is addressed by the BASIS project (Build Automation by a Scalable and Intelligent System), which aims to build a cross-domain home bus system. The main objective of this paper is to present an overview of design, architecture and state of realization of BASIS by describing the requirements development process, underlying hardware design and software architecture. We built a distributed system of one independent building manager with several redundantly meshed segment controllers, each controlling a bus segment with any number of bus nodes. The software system layer is divided into logical partitions representing each sub-domain. Structured data storage is possible with a special FHIR based home centered data warehouse. The system has been implemented in six apartments running under daily living conditions. BASIS integrates a broad range of sub-domains, which poses challenges to all project partners in terms of a common terminology, and project management methods, but enables development of inter-domain synergies like using the same sensor and actuator hardware for a broad range of services and use cases.

HD domain of SAMHD1 influences Vpx-induced degradation at a post-interaction step

Energy Technology Data Exchange (ETDEWEB)

Kang, Jian; Hou, Jingwei; Zhao, Ke; Yu, Xiao-Fang; Du, Juan, E-mail: jdu@jlu.edu.cn

2016-02-12

Primate SAMHD1 proteins are potent inhibitors of viruses, including retroviruses such as HIV-1, HIV-2, and SIV. Vpx, a distinctive viral protein expressed by HIV-2 and some SIVs, induces SAMHD1 degradation by forming a Vpx-DCAF1-based ubiquitin ligase complex. Either the N- or the C-terminus of SAMHD1 is critical for Vpx-induced degradation, depending on the types of SAMHD1 and Vpx proteins. However, it was not fully understood whether other regions of SAMHD1 also contribute to its depletion by Vpx. In the present study, we report that SAMHD1 from chicken (SAMHD1{sub GG}) was not degraded by SIVmac Vpx, in contrast with results for human SAMHD1 (SAMHD1{sub HS}). Results regarding to SAMHD1{sub HS} and SAMHD1{sub GG} fusion proteins supported previous findings that the C-terminus of SAMHD1{sub HS} is essential for Vpx-induced degradation. Internal domain substitution, however, revealed that the HD domain also contributes to Vpx-mediated SAMHD1 degradation. Interestingly, the HD domain influenced Vpx-mediated SAMHD1 degradation without affecting Vpx-SAMHD1 interaction. Therefore, our findings revealed that factors in addition to Vpx-SAMHD1 binding influence the efficiency of Vpx-mediated SAMHD1 degradation. - Highlights: • SAMHD1{sub GG} from chicken could not be depleted by SIVmac Vpx. • The C-terminus of human SAMHD1{sub HS} is critical for its degradation by Vpx. • The HD domain is essential for Vpx-induced degradation of SAMHD1{sub HS}. • Altering the HD domain does not affect Vpx-SAMHD1 interaction.

Geometric control theory and sub-Riemannian geometry

CERN Document Server

Boscain, Ugo; Gauthier, Jean-Paul; Sarychev, Andrey; Sigalotti, Mario

2014-01-01

This volume presents recent advances in the interaction between Geometric Control Theory and sub-Riemannian geometry. On the one hand, Geometric Control Theory used the differential geometric and Lie algebraic language for studying controllability, motion planning, stabilizability and optimality for control systems. The geometric approach turned out to be fruitful in applications to robotics, vision modeling, mathematical physics etc. On the other hand, Riemannian geometry and its generalizations, such as  sub-Riemannian, Finslerian  geometry etc., have been actively adopting methods developed in the scope of geometric control. Application of these methods  has led to important results regarding geometry of sub-Riemannian spaces, regularity of sub-Riemannian distances, properties of the group  of diffeomorphisms of sub-Riemannian manifolds, local geometry and equivalence of distributions and sub-Riemannian structures, regularity of the Hausdorff volume.

Hysteresis loops and the demagnetization process at 4.2 K for melt-spun Nd sub 1 sub 3 Fe sub 7 sub 7 B sub 1 sub 0

CERN Document Server

Jin Han Min; Park, W S; Park, M J; Wang Xue Feng

1998-01-01

Hysteresis loops of melt-spun Nd sub 1 sub 3 Fe sub 7 sub 7 B sub 1 sub 0 cooled down at the remanent state were measured at 4.2 K. The loop for fields of H sub m sub a sub x =6.4 MA m sup - sup 1 is characterized by low- and high-field steps. The loop for fields of H sub m sub a sub x =4.0 MA m sup - sup 1 is very thin with only a low-field step and is shifted profoundly along the H-axes. The loops and the spin distribution during the demagnetization process were analysed by micromagnetic finite-element calculations. Quantitatively, the calculations reproduce the experimental loops fairly well. The spin distribution is fairly nonuniform, and a domain-wall-like distribution appears not only at some grain boundaries but also within some grains at the high-field step. The demagnetization proceeds by nonuniform reversion as a whole, and neither the model of single-domain reversion nor the model of domain-wall pinning in the grain boundary model describes the process appropriately. (author)

Distinct DNA methylation epigenotypes in bladder cancer from different Chinese sub-populations and its implication in cancer detection using voided urine

Directory of Open Access Journals (Sweden)

Tong Joanna HM

2011-05-01

Full Text Available Abstract Background Bladder cancer is the sixth most common cancer in the world and the incidence is particularly high in southwestern Taiwan. Previous studies have identified several tumor-related genes that are hypermethylated in bladder cancer; however the DNA methylation profile of bladder cancer in Taiwan is not fully understood. Methods In this study, we compared the DNA methylation profile of multiple tumor suppressor genes (APC, DAPK, E-cadherin, hMLH1, IRF8, p14, p15, RASSF1A, SFRP1 and SOCS-1 in bladder cancer patients from different Chinese sub-populations including Taiwan (104 cases, Hong Kong (82 cases and China (24 cases by MSP. Two normal human urothelium were also included as control. To investigate the diagnostic potential of using DNA methylation in non-invasive detection of bladder cancer, degree of methylation of DAPK, IRF8, p14, RASSF1A and SFRP1 was also accessed by quantitative MSP in urine samples from thirty bladder cancer patients and nineteen non-cancer controls. Results There were distinct DNA methylation epigenotypes among the different sub-populations. Further, samples from Taiwan and China demonstrated a bimodal distribution suggesting that CpG island methylator phentotype (CIMP is presented in bladder cancer. Moreover, the number of methylated genes in samples from Taiwan and Hong Kong were significantly correlated with histological grade (P SFRP1, IRF8, APC and RASSF1A were significantly associated with increased tumor grade, stage. Methylation of RASSF1A was associated with tumor recurrence. Patients with methylation of APC or RASSF1A were also significantly associated with shorter recurrence-free survival. For methylation detection in voided urine samples of cancer patients, the sensitivity and specificity of using any of the methylated genes (IRF8, p14 or sFRP1 by qMSP was 86.7% and 94.7%. Conclusions Our results indicate that there are distinct methylation epigenotypes among different Chinese sub

Distinct Functional Domains of Ubc9 Dictate Cell Survival and Resistance to Genotoxic Stress

Science.gov (United States)

van Waardenburg, Robert C. A. M.; Duda, David M.; Lancaster, Cynthia S.; Schulman, Brenda A.; Bjornsti, Mary-Ann

2006-01-01

Covalent modification with SUMO alters protein function, intracellular localization, or protein-protein interactions. Target recognition is determined, in part, by the SUMO E2 enzyme, Ubc9, while Siz/Pias E3 ligases may facilitate select interactions by acting as substrate adaptors. A yeast conditional Ubc9P123L mutant was viable at 36°C yet exhibited enhanced sensitivity to DNA damage. To define functional domains in Ubc9 that dictate cellular responses to genotoxic stress versus those necessary for cell viability, a 1.75-Å structure of yeast Ubc9 that demonstrated considerable conservation of backbone architecture with human Ubc9 was solved. Nevertheless, differences in side chain geometry/charge guided the design of human/yeast chimeras, where swapping domains implicated in (i) binding residues within substrates that flank canonical SUMOylation sites, (ii) interactions with the RanBP2 E3 ligase, and (iii) binding of the heterodimeric E1 and SUMO had distinct effects on cell growth and resistance to DNA-damaging agents. Our findings establish a functional interaction between N-terminal and substrate-binding domains of Ubc9 and distinguish the activities of E3 ligases Siz1 and Siz2 in regulating cellular responses to genotoxic stress. PMID:16782883

The Yin and Yang of SagS: Distinct Residues in the HmsP Domain of SagS Independently Regulate Biofilm Formation and Biofilm Drug Tolerance

Science.gov (United States)

Dingemans, Jozef; Poudyal, Bandita

2018-01-01

ABSTRACT The formation of inherently drug-tolerant biofilms by the opportunistic pathogen Pseudomonas aeruginosa requires the sensor-regulator hybrid SagS, with ΔsagS biofilms being unstructured and exhibiting increased antimicrobial susceptibility. Recent findings indicated SagS to function as a switch to control biofilm formation and drug tolerance independently. Moreover, findings suggested the periplasmic sensory HmsP domain of SagS is likely to be the control point in the regulation of biofilm formation and biofilm cells transitioning to a drug-tolerant state. We thus asked whether specific amino acid residues present in the HmsP domain contribute to the switch function of SagS. HmsP domain residues were therefore subjected to alanine replacement mutagenesis to identify substitutions that block the sensory function(s) of SagS, which is apparent by attached cells being unable to develop mature biofilms and/or prevent transition to an antimicrobial-resistant state. Mutant analyses revealed 32 residues that only contribute to blocking one sensory function. Moreover, amino acid residues affecting attachment and subsequent biofilm formation but not biofilm tolerance also impaired histidine kinase signaling via BfiS. In contrast, residues affecting biofilm drug tolerance but not attachment and subsequent biofilm formation negatively impacted BrlR transcription factor levels. Structure prediction suggested the two sets of residues affecting sensory functions are located in distinct areas that were previously described as being involved in ligand binding interactions. Taken together, these studies identify the molecular basis for the dual regulatory function of SagS. IMPORTANCE The membrane-bound sensory protein SagS plays a pivotal role in P. aeruginosa biofilm formation and biofilm cells gaining their heightened resistance to antimicrobial agents, with SagS being the control point at which both pathways diverge. Here, we demonstrate for the first time that the two

Frequency-domain and time-domain methods for feedback nonlinear systems and applications to chaos control

International Nuclear Information System (INIS)

Duan Zhisheng; Wang Jinzhi; Yang Ying; Huang Lin

2009-01-01

This paper surveys frequency-domain and time-domain methods for feedback nonlinear systems and their possible applications to chaos control, coupled systems and complex dynamical networks. The absolute stability of Lur'e systems with single equilibrium and global properties of a class of pendulum-like systems with multi-equilibria are discussed. Time-domain and frequency-domain criteria for the convergence of solutions are presented. Some latest results on analysis and control of nonlinear systems with multiple equilibria and applications to chaos control are reviewed. Finally, new chaotic oscillating phenomena are shown in a pendulum-like system and a new nonlinear system with an attraction/repulsion function.

Distinct Subunit Domains Govern Synaptic Stability and Specificity of the Kainate Receptor

Directory of Open Access Journals (Sweden)

Christoph Straub

2016-07-01

Full Text Available Synaptic communication between neurons requires the precise localization of neurotransmitter receptors to the correct synapse type. Kainate-type glutamate receptors restrict synaptic localization that is determined by the afferent presynaptic connection. The mechanisms that govern this input-specific synaptic localization remain unclear. Here, we examine how subunit composition and specific subunit domains contribute to synaptic localization of kainate receptors. The cytoplasmic domain of the GluK2 low-affinity subunit stabilizes kainate receptors at synapses. In contrast, the extracellular domain of the GluK4/5 high-affinity subunit synergistically controls the synaptic specificity of kainate receptors through interaction with C1q-like proteins. Thus, the input-specific synaptic localization of the native kainate receptor complex involves two mechanisms that underlie specificity and stabilization of the receptor at synapses.

All-in-all-out magnetic domain size in pyrochlore iridate thin films as probed by local magnetotransport

Energy Technology Data Exchange (ETDEWEB)

Fujita, T. C.; Uchida, M., E-mail: uchida@ap.t.u-tokyo.ac.jp; Kozuka, Y.; Ogawa, S. [Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656 (Japan); Tsukazaki, A. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); PRESTO, Japan Science and Technology Agency (JST), Tokyo 102-0075 (Japan); Arima, T. [Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561 (Japan); RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan); Kawasaki, M. [Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656 (Japan); RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan)

2016-01-11

Pyrochlore iridates have attracted growing attention because of a theoretical prediction of a possible topological semimetal phase originating from all-in-all-out spin ordering. Related to the topological band structure, recent findings of the magnetic domain wall conduction have stimulated investigations of magnetic domain distribution in this system. Here, we investigate the size of magnetic domains in Eu{sub 2}Ir{sub 2}O{sub 7} single crystalline thin films by magnetoresistance (MR) using microscale Hall bars. Two distinct magnetic domains of the all-in-all-out spin structure are known to exhibit linear MR but with opposite signs, which enables us to estimate the ratio of the two domains in the patterned channel. The linear MR for 80 × 60 μm{sup 2} channel is nearly zero after zero-field cooling, suggesting random distribution of domains smaller than the channel size. In contrast, the wide distribution of the value of the linear MR is detected in 2 × 2 μm{sup 2} channel, reflecting the detectable domain size depending on each cooling-cycle. Compared to simulation results, we estimate the average size of a single all-in-all-out magnetic domain as 1–2 μm.

Binding of the cSH3 domain of Grb2 adaptor to two distinct RXXK motifs within Gab1 docker employs differential mechanisms.

Science.gov (United States)

McDonald, Caleb B; Seldeen, Kenneth L; Deegan, Brian J; Bhat, Vikas; Farooq, Amjad

2011-01-01

A ubiquitous component of cellular signaling machinery, Gab1 docker plays a pivotal role in routing extracellular information in the form of growth factors and cytokines to downstream targets such as transcription factors within the nucleus. Here, using isothermal titration calorimetry (ITC) in combination with macromolecular modeling (MM), we show that although Gab1 contains four distinct RXXK motifs, designated G1, G2, G3, and G4, only G1 and G2 motifs bind to the cSH3 domain of Grb2 adaptor and do so with distinct mechanisms. Thus, while the G1 motif strictly requires the PPRPPKP consensus sequence for high-affinity binding to the cSH3 domain, the G2 motif displays preference for the PXVXRXLKPXR consensus. Such sequential differences in the binding of G1 and G2 motifs arise from their ability to adopt distinct polyproline type II (PPII)- and 3(10) -helical conformations upon binding to the cSH3 domain, respectively. Collectively, our study provides detailed biophysical insights into a key protein-protein interaction involved in a diverse array of signaling cascades central to health and disease. Copyright © 2010 John Wiley & Sons, Ltd.

Hydrogen diffusion in a one domain. beta. -V sub 2 H single crystal

Energy Technology Data Exchange (ETDEWEB)

Richter, D.; Mahling-Ennaoui, S. (Institut Max von Laue - Paul Langevin, 38 - Grenoble (France)); Hempelmann, R. (Forschungszentrum Juelich GmbH (Germany, F.R.). Inst. fuer Festkoerperforschung)

1989-01-01

The authors present first quasielastic neutron scattering experiments on hydrogen diffusion in a one-domain crystal of the ordered metal hydride {beta}-V{sub 2}H. The experiments led to a detailed evaluation of the microscopic jump geometries. At temperatures at which the structure is still intact the main diffusion channel leads across antistructural sites situated in empty layers in between occupied H-sheets. (orig.).

Current-induced domain wall motion in Ni{sub 80}Fe{sub 20} nanowires with low depinning fields

Energy Technology Data Exchange (ETDEWEB)

Malinowski, Gregory; Loerincz, Andreas; Krzyk, Stephen; Moehrke, Philipp; Bedau, Daniel; Boulle, Olivier; Rhensius, Jan; Klaeui, Mathias [Fachbereich Physik, Universitaet Konstanz, Universitaetsstrasse 10, D-78457 (Germany); Heyderman, Laura J [Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Cho, Young Jin; Seo, Sunae, E-mail: gregory.malinowski@uni-konstanz.d [Samsung Electronics, San 14-1 Nongseo-dong, Giheung-gu, Yongin-si, Gyeonggi-do (Korea, Republic of)

2010-02-03

In this paper, we report on domain wall (DW) motion induced by current pulses at variable temperature in 900 nm wide and 25 nm thick Ni{sub 80}Fe{sub 20} wires with low pinning fields. By using Ar ion milling to pattern our wires rather than the conventional lift-off technique, a depinning field as low as {approx}2-3 Oe at room temperature is obtained. Comparison with previous results acquired on similar wires with much higher pinning shows that the critical current density scales with the depinning field, leading to a critical current density of {approx}2.5 x 10{sup 11} A m{sup -2} at 250 K. Moreover, when a current pulse with a current density larger than the critical current density is injected, the DW is not necessarily depinned but it can undergo a modification of its spin structure which hinders current-induced DW motion. Hence, reliable propagation of the DW requires an accurate adjustment of the pulsed current density.

Human phenotypically distinct TGFBI corneal dystrophies are linked to the stability of the fourth FAS1 domain of TGFBIp

DEFF Research Database (Denmark)

Runager, Kasper; Basaiawmoit, Rajiv Vaid; Deva, Taru

2011-01-01

Mutations in the human TGFBI gene encoding TGFBIp have been linked to protein deposits in the cornea leading to visual impairment. The protein consists of an N-terminal Cys-rich EMI domain and four consecutive fasciclin 1 (FAS1) domains. We have compared the stabilities of wild-type (WT) human...... TGFBIp and six mutants known to produce phenotypically distinct deposits in the cornea. Amino acid substitutions in the first FAS1 (FAS1-1) domain (R124H, R124L, and R124C) did not alter the stability. However, substitutions within the fourth FAS1 (FAS1-4) domain (A546T, R555Q, and R555W) affected...... the overall stability of intact TGFBIp revealing the following stability ranking R555W>WT>R555Q>A546T. Significantly, the stability ranking of the isolated FAS1-4 domains mirrored the behavior of the intact protein. In addition, it was linked to the aggregation propensity as the least stable mutant (A546T...

Time-domain calculation of sub-nanosecond pulse launched by a proton beam

International Nuclear Information System (INIS)

Chan, Kwok-Chi Dominic; Cooper, R.K.

1990-01-01

Using the finite-difference time-domain code TBCI, we have numerically calculated the radiation from a sub-nanosecond 800-MeV proton bunch as it is launched into space. The calculation is compared to measurements of the time history of the radiated fields and good agreement is found. A movie showing the development of the radiation pattern will be shown during the presentation at this conference, namely, the First Los Alamos Symposium on Ultra-Wideband Radar. 6 refs., 7 figs

Direct observation of stochastic domain-wall depinning in magnetic nanowires

Energy Technology Data Exchange (ETDEWEB)

Im, Mi-Young; Bocklage, Lars; Fischer, Peter; Meier, Guido

2008-11-01

The stochastic field-driven depinning of a domain wall pinned at a notch in a magnetic nanowire is directly observed using magnetic X-ray microscopy with high lateral resolution down to 15 nm. The depinning-field distribution in Ni{sub 80}Fe{sub 20} nanowires considerably depends on the wire width and the notch depth. The difference in the multiplicity of domain-wall types generated in the vicinity of a notch is responsible for the observed dependence of the stochastic nature of the domain wall depinning field on the wire width and the notch depth. Thus the random nature of the domain wall depinning process is controllable by an appropriate design of the nanowire.

Magnetic properties of electron-doped La{sub 0.23}Ca{sub 0.77}MnO{sub 3} nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Markovich, V., E-mail: markoviv@bgu.ac.il; Jung, G. [Ben-Gurion University of the Negev, Department of Physics (Israel); Wisniewski, A. [Polish Academy of Sciences, Institute of Physics (Poland); Mogilyansky, D. [Ben-Gurion University of the Negev, Ilse Katz Institute for Nanoscale Science and Technology (Israel); Puzniak, R. [Polish Academy of Sciences, Institute of Physics (Poland); Kohn, A. [Ben-Gurion University of the Negev, Ilse Katz Institute for Nanoscale Science and Technology (Israel); Wu, X. D.; Suzuki, K. [Monash University, Department of Materials Engineering (Australia); Gorodetsky, G. [Ben-Gurion University of the Negev, Department of Physics (Israel)

2012-09-15

Magnetic properties of electron-doped La{sub 0.23}Ca{sub 0.77}MnO{sub 3} manganite nanoparticles, with average size of 12 and 60 nm, prepared by the glycine-nitrate method, have been investigated in the temperature range 5-300 K and magnetic fields up to 90 kOe. It is suggested that weak ferromagnetic moment results from ferromagnetic shells of the basically antiferromagnetic nanoparticles and from domains of frustrated disordered phase in the core. Assumption of two distinct sources of ferromagnetism is supported by the appearance of two independent ferromagnetic contributions in the fit of the T{sup 3/2} Bloch law to spontaneous magnetization. The ferromagnetic components, which are more pronounced in smaller particles, occupy only a small fraction of the nanoparticle volume and the antiferromagnetic ground state remains stable. It is found that the magnetic hysteresis loops following field cooled processes, display size-dependent horizontal and vertical shifts, namely, exhibiting exchange bias effect. Time-dependent magnetization dynamics demonstrating two relaxation rates were observed at constant magnetic fields upon cooling to T < 100 K.

Crystallization of the amorphous Fe{sub 80}Zr{sub 12}B{sub 8} alloy under controlled heating

Energy Technology Data Exchange (ETDEWEB)

Huang, H. [School of Engineering (H6), University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Shao, G. [Centre for Materials Research and Innovation, University of Bolton, Bolton BL3 5AB (United Kingdom)], E-mail: G.Shao@bolton.ac.uk; Tsakiropoulos, P. [Department of Engineering Materials, Sir Robert Hadfirld Building, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

2008-07-14

The devitrification process of amorphous Fe{sub 80}Zr{sub 12}B{sub 8} alloy ribbons were studied under controlled thermal conditions. The major crystallization event during continuous heating with differential scanning calorimetory (DSC) is dictated by diffusion controlled growth and the associated atom mobility of the slow diffusing species Zr. The existence of prior nano-crystals formed by pre-annealing below the crystallization temperature had little effect on the major crystallization temperature. The crystallization sequence during heating was: amorphous {yields} amorphous + {alpha}-Fe + Fe{sub 3}Zr(B) {yields} amorphous + {alpha}-Fe + Fe{sub 3}Zr(B) + Fe{sub 2}Zr. Different from previous findings in alloys of lower Zr and B contents, the peak for the crystallization of the {alpha}-Fe phase alone is missing in the DSC traces of this alloy.

In situ control of As dimer orientation on Ge(100) surfaces

Energy Technology Data Exchange (ETDEWEB)

Brueckner, Sebastian; Doescher, Henning [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Technische Universitaet Ilmenau, Institut fuer Physik, Postfach 10 05 65, 98684 Ilmenau (Germany); Supplie, Oliver; Luczak, Johannes [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Barrigon, Enrique; Rey-Stolle, Ignacio [Instituto de Energia Solar, Universidad Politecnica de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Kleinschmidt, Peter [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); CiS Forschungsinstitut fuer Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Strasse 14, 99099 Erfurt (Germany); Hannappel, Thomas [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Technische Universitaet Ilmenau, Institut fuer Physik, Postfach 10 05 65, 98684 Ilmenau (Germany); CiS Forschungsinstitut fuer Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Strasse 14, 99099 Erfurt (Germany)

2012-09-17

We investigated the preparation of single domain Ge(100):As surfaces in a metal-organic vapor phase epitaxy reactor. In situ reflection anisotropy spectra (RAS) of vicinal substrates change when arsenic is supplied either by tertiarybutylarsine or by background As{sub 4} during annealing. Low energy electron diffraction shows mutually perpendicular orientations of dimers, scanning tunneling microscopy reveals distinct differences in the step structure, and x-ray photoelectron spectroscopy confirms differences in the As coverage of the Ge(100):As samples. Their RAS signals consist of contributions related to As dimer orientation and to step structure, enabling precise in situ control over preparation of single domain Ge(100):As surfaces.

Magnetic model for Mn{sub 2}La{sub 2} developed from spectroscopic studies with inelastic neutron scattering and frequency-domain Fourier-transform THz EPR

Energy Technology Data Exchange (ETDEWEB)

Milazzo, R.; Nehrkorn, J.; Stuiber, S.; Waldmann, O. [Physikalisches Institut, Universitaet Freiburg (Germany); Akhtar, M.N.; Lan, Y.; Powell, A.K. [Institut fuer Anorganische Chemie, Universitaet Karlsruhe, KIT (Germany); Mutka, H. [Institut Laue Langevin, Grenoble (France); Dreiser, J. [Swiss Light Source, Paul Scherrer Institut (Switzerland); Schnegg, A. [Helmholtz-Zentrum Berlin, Institut fuer Silizium-Photovoltaik (Germany); Holldack, K. [Helmholtz-Zentrum Berlin, Institut fuer Synchrotonstrahlung (Germany)

2011-07-01

Molecular nanomagnets which contain several magnetic centers with a large single-ion magnetic anisotropy are of general interest, because they could lead to interesting phenomena such as single-molecule magnet (SMM) behavior. We performed spectroscopic experiments on Mn{sub 2}La{sub 2} using inelastic neutron scattering at the direct time-of-flight disc chopper spectrometer IN5 at ILL and the newly developed frequency-domain Fourier-transform THz EPR at BESSY. Based on the experimental results a magnetic model has been developed. It is discussed why no SMM behavior was observed, even though Mn{sub 2}La{sub 2} exhibits a remarkably high energy barrier of about 37 K for spin relaxation. Furthermore our results can be applied to analogous clusters, with the diamagnetic La{sup I}II ions replaced by magnetic rare earth ions.

Control of Sulfidogenesis Through Bio-oxidation of H<sub>2sub>S Coupled to (per)chlorate Reduction

Energy Technology Data Exchange (ETDEWEB)

Gregoire, Patrick [Univ. of California, Berkeley, CA (United States); Engelbrektson, Anna [Univ. of California, Berkeley, CA (United States); Hubbard, Christopher G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Metlagel, Zoltan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Csencsits, Roseann [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Auer, Manfred [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Conrad, Mark E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Thieme, Jurgen [Brookhaven National Lab. (BNL), Upton, NY (United States); Northrup, Paul [Brookhaven National Lab. (BNL), Upton, NY (United States); Coates, John D. [Univ. of California, Berkeley, CA (United States)

2014-04-04

Here, we investigate H<sub>2sub>S attenuation by dissimilatory perchlorate-reducing bacteria (DPRB). All DPRB tested oxidized H<sub>2sub>S coupled to (per)chlorate reduction without sustaining growth. H<sub>2sub>S was preferentially utilized over organic electron donors resulting in an enriched (34S)-elemental sulfur product. Electron microscopy revealed elemental sulfur production in the cytoplasm and on the cell surface of the DPRB Azospira suillum. We also propose a novel hybrid enzymatic-abiotic mechanism for H<sub>2sub>S oxidation similar to that recently proposed for nitrate-dependent Fe(II) oxidation. The results of this study have implications for the control of biosouring and biocorrosion in a range of industrial environments.

Generalized predictive control in the delta-domain

DEFF Research Database (Denmark)

Lauritsen, Morten Bach; Jensen, Morten Rostgaard; Poulsen, Niels Kjølstad

1995-01-01

This paper describes new approaches to generalized predictive control formulated in the delta (δ) domain. A new δ-domain version of the continuous-time emulator-based predictor is presented. It produces the optimal estimate in the deterministic case whenever the predictor order is chosen greater...... than or equal to the number of future predicted samples, however a “good” estimate is usually obtained in a much longer range of samples. This is particularly advantageous at fast sampling rates where a “conventional” predictor is bound to become very computationally demanding. Two controllers...

Unveiling the Structural Evolution of Ag<sub>1.2sub>Mn>8sub>O>16sub> under Coulombically Controlled (De)Lithiation

Energy Technology Data Exchange (ETDEWEB)

Huang, Jianping [Department; Hu, Xiaobing [Energy; Brady, Alexander B. [Department; Wu, Lijun [Energy; Zhu, Yimei [Energy; Takeuchi, Esther S. [Department; Energy; Department; Marschilok, Amy C. [Department; Department; Takeuchi, Kenneth J. [Department; Department

2018-01-02

MnO<sub>2sub> materials are considered promising cathode materials for rechargeable lithium, sodium, and magnesium batteries due to their earth abundance and environmental friendliness. One polymorph of MnO<sub>2sub>, α-MnO<sub>2sub>, has 2 × 2 tunnels (4.6 Å × 4.6 Å) in its structural framework, which provide facile diffusion pathways for guest ions. In this work, a silver-ion-containing α-MnO<sub>2sub> (Ag<sub>1.2sub>Mn>8sub>O>16sub>) is examined as a candidate cathode material for Li based batteries. Electrochemical stability of Ag<sub>1.2sub>Mn>8sub>O>16sub> is investigated through Coulombically controlled reduction under 2 or 4 molar electron equivalents (e.e.). Terminal discharge voltage remains almost constant under 2 e.e. of cycling, whereas it continuously decreases under repetitive reduction by 4 e.e. Thus, detailed structural analyses were utilized to investigate the structural evolution upon lithiation. Significant increases in lattice a (17.7%) and atomic distances (~4.8%) are observed when x in Li<sub>xAg>1.2sub>Mn>8sub>O>16sub> is >4. Ag metal forms at this level of lithiation concomitant with a large structural distortion to the Mn–O framework. In contrast, lattice a only expands by 2.2% and Mn–O/Mn-Mn distances show minor changes (~1.4%) at x < 2. The structural deformation (tunnel breakage) at x > 4 inhibits the recovery of the original structure, leading to poor cycle stability at high lithiation levels. This report establishes the correlation among local structure changes, amorphization processes, formation of Ag⁰, and long-term cycle stability for this silver-containing α-MnO<sub>2sub> type material at both low and high lithiation levels.

Zn-binding AZUL domain of human ubiquitin protein ligase Ube3A

Energy Technology Data Exchange (ETDEWEB)

Lemak, Alexander; Yee, Adelinda [University of Toronto, and Northeast Structural Genomics Consortium, Ontario Cancer Institute, Campbell Family Cancer Research Institute and Department of Medical Biophysics (Canada); Bezsonova, Irina, E-mail: bezsonova@uchc.edu [University of Connecticut Health Center, Department of Molecular Microbial and Structural Biology (United States); Dhe-Paganon, Sirano, E-mail: sirano.dhepaganon@utoronto.ca [University of Toronto, Structural Genomics Consortium (Canada); Arrowsmith, Cheryl H., E-mail: carrow@uhnresearch.ca [University of Toronto, and Northeast Structural Genomics Consortium, Ontario Cancer Institute, Campbell Family Cancer Research Institute and Department of Medical Biophysics (Canada)

2011-09-15

Ube3A (also referred to as E6AP for E6 Associated Protein) is a E3 ubiquitin-protein ligase implicated in the development of Angelman syndrome by controlling degradation of synaptic protein Arc and oncogenic papilloma virus infection by controlling degradation of p53. This article describe the solution NMR structure of the conserved N-terminal domain of human Ube3A (residues 24-87) that contains two residues (Cys44 and Arg62) found to be mutated in patients with Angelman syndrome. The structure of this domain adopts a novel Zn-binding fold we called AZUL (Amino-terminal Zn-finger of Ube3a Ligase). The AZUL domain has a helix-loop-helix architecture with a Zn ion coordinated by four Cys residues arranged in Cys-X{sub 4}-Cys-X{sub 4}-Cys-X{sub 28}-Cys motif. Three of the Zn-bound residues are located in a 23-residue long and well structured loop that connects two {alpha}-helicies.

Analysis of gene expression data from non-small cell lung carcinoma cell lines reveals distinct sub-classes from those identified at the phenotype level.

Directory of Open Access Journals (Sweden)

Andrew R Dalby

Full Text Available Microarray data from cell lines of Non-Small Cell Lung Carcinoma (NSCLC can be used to look for differences in gene expression between the cell lines derived from different tumour samples, and to investigate if these differences can be used to cluster the cell lines into distinct groups. Dividing the cell lines into classes can help to improve diagnosis and the development of screens for new drug candidates. The micro-array data is first subjected to quality control analysis and then subsequently normalised using three alternate methods to reduce the chances of differences being artefacts resulting from the normalisation process. The final clustering into sub-classes was carried out in a conservative manner such that sub-classes were consistent across all three normalisation methods. If there is structure in the cell line population it was expected that this would agree with histological classifications, but this was not found to be the case. To check the biological consistency of the sub-classes the set of most strongly differentially expressed genes was be identified for each pair of clusters to check if the genes that most strongly define sub-classes have biological functions consistent with NSCLC.

Diffusion of aluminium during the transformation UAl{sub 3} - UAl{sub 4} in the solid state; Diffusion de l'aluminium dans la transformation UAl{sub 3} - UAl{sub 4} a l'etat solide

Energy Technology Data Exchange (ETDEWEB)

Boucher, R [Commissariat a l' Energie Atomique, Fontenay aux Roses (France).Centre d' Etudes Nucleaires

1959-07-01

The alloys studied which contain 40 % uranium, are quenched from the region liquid + UAl{sub 3} so as to obtain pure crystals of UAl{sub 3}. These samples are then heat treated at 600 deg. C (at which point Al and UAl{sub 4} are in equilibrium) for varying durations in order to permit the transformation of UAl{sub 3} to UA{sub 4}. This transformation presumably takes place by the diffusion of aluminium through the UAl{sub 4}. The evolution of the transformation UAl{sub 3} {yields} UAl{sub 4} is followed micro-graphically. The compounds are distinguished by: - colour; - examination under polarised light; - microhardness measurements. The kinetics of the transformation are strongly influenced by the presence of elements such as silicon in relatively small quantities. In the absence of silicon UAl{sub 3}, crystals are transformed to UAl{sub 4} in approximately one hour. For low silicon contents (0,1% by weight) the transformation takes ten times longer. Silicon concentrations of 0,6 practically stop the transformation. After a hundred hours a slight transformation is observed, but this transformation is no further advanced even after 1000 hours. (author) [French] Les alliages etudies, de teneur en uranium egale a 40 % en poids, sont trempes a partir du domaine 'liquide + UAl{sub 3}'; pour obtenir des cristaux UAl{sub 3} purs. Ces echantillons sont ensuite traites a 500 deg. C dans le domaine 'AI + UAl{sub 4}' pendant des temps varies pour transformer UAl{sub 3} en UAl{sub 4}. Cette transformation se fait vraisemblablement par diffusion de l'aluminium a travers UAl{sub 4}. On suit l'evolution UAl{sub 3} {yields} UAl{sub 4} principalement par methode micrographique. L'identification et la distinction des composes se font a l'aide: - de colorations; - d'examens en lumiere polarisee; - de mesures de microduretes. La cinetique de la transformation est fortement influencee par la presence d'elements tels que le silicium - en quantite relativement faible. Sans silicium, les

MULTILOOP PI CONTROLLER FOR ACHIEVING SIMULTANEOUS TIME AND FREQUENCY DOMAIN SPECIFICATIONS

Directory of Open Access Journals (Sweden)

M. SENTHILKUMAR

2015-08-01

Full Text Available Most of the controllers in control system are designed to satisfy either time domain or frequency domain specifications. This work presents the computation of a multiloop PI controller for achieving time and frequency domain specifications simultaneously. The desired time and frequency domain measures are to be specified initially to the design. To obtain the desired value of the performance measures the graphical relationship between the PI controller and the performance criteria is given. Thus by using graphical method a set of PI controller parameters to meet the desired performance measures are obtained in an effective and simpler way. The coupled tank has become a classic design of control engineering for multivariable process. The proposed control strategy has been implemented in the same coupled tank process and validated through simulation studies.

Is there any need for domain-dependent control information? A reply

Energy Technology Data Exchange (ETDEWEB)

Minton, S. [USC Information Sciences Inst., Marina del Rey, CA (United States)

1996-12-31

In this paper, we consider the role that domain-dependent control knowledge plays in problem solving systems. Ginsberg and Geddis have claimed that domain-dependent control information has no place in declarative systems; instead, they say, such information should be derived from declarative facts about the domain plus domain-independent principles. We dispute their conclusion, arguing that it is impractical to generate control knowledge solely on the basis of logical derivations. We propose that simplifying abstractions are crucial for deriving control knowledge, and, as a result, empirical utility evaluation of the resulting rules will frequently be necessary to validate the utility of derived control knowledge. We illustrate our arguments with examples from two implemented systems.

Persistence of slow fluctuations in the overdoped regime of Ba(Fe<sub>1-xsub>Rh_x)>2sub>As>2sub> superconductors

Energy Technology Data Exchange (ETDEWEB)

Bossoni, L. [Univ. of Pavia (Italy); Leiden Univ. (Netherlands); Moroni, M. [Univ. of Pavia (Italy); Julien, M. H. [Leiden Univ. (Netherlands); Canfield, Paul C. [Ames Lab. and Iowa State Univ., Ames, IA (United States); Mayaffre, H. [Leiden Univ. (Netherlands); Reyes, A. [National High Magnetic Field Lab., Tallahassee, FL (United States); Halperin, W. P. [Northwestern Univ., Evanston, IL (United States); Carretta, P. [Univ. of Pavia (Italy)

2016-04-15

We present nuclear magnetic resonance evidence that very slow (1 MHz) spin fluctuations persist into the overdoped regime of Ba(Fe<sub>1-xsub>Rh_x)>2sub>As>2sub> superconductors. Measurements of the ⁷⁵As spin echo decay rate, obtained both with Hahn Echo and Carr Purcell Meiboom Gill pulse sequences, show that the slowing down of spin uctuations can be described by short-range diffusive dynamics, likely involving domain walls motions separating (π/a, 0) from (0, π/a) correlated regions. This slowing down of the fluctuations is weakly sensitive to the external magnetic field and, although fading away with doping, it extends deeply into the overdoped regime.

Anti-phase boundaries and magnetic domain structures in Ni{sub 2}MnGa-type Heusler alloys

Energy Technology Data Exchange (ETDEWEB)

Venkateswaran, S.P. [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); Nuhfer, N.T. [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); De Graef, M. [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States)]. E-mail: degraef@cmu.edu

2007-05-15

The microstructure and magnetic domain structure of austenitic Heusler Ni{sub 2}MnGa are investigated as a function of heat treatment to study the interplay of anti-phase boundaries and magnetic domain walls. Conventional electron microscopy observations on arc-melted polycrystalline samples show that anti-phase boundaries in this system are invisible for standard two-beam imaging conditions, due to the large extinction distance of the Heusler superlattice reflections. Lorentz Fresnel and Foucault observations on quenched samples reveal a wavy magnetic domain morphology, reminiscent of curved anti-phase boundaries. A close inspection of the domain images indicates that the anti-phase boundaries have a magnetization state different from that of the matrix. Fresnel image simulations for a simple magnetization model are in good agreement with the observations. Magnetic coercivity measurements show a decrease in coercivity with annealing, which correlates with the microscopy observations of reduced anti-phase boundary density for annealed samples.

Temperature dependence of the coercive field of gas atomized Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1}

Energy Technology Data Exchange (ETDEWEB)

Garcia-Escorial, A., E-mail: age@cenim.csic.es [CENIM-CSIC, Avda, Gregorio del Amo, 8, 28040 Madrid (Spain); Lieblich, M. [CENIM-CSIC, Avda, Gregorio del Amo, 8, 28040 Madrid (Spain); Hernando, A.; Aragon, A.; Marin, P. [Instituto de Magnetismo Aplicado, IMA, P.O. Box 155, 28230 Madrid (Spain)

2012-09-25

Highlights: Black-Right-Pointing-Pointer An anomalous thermal dependence of the coercive field of gas atomized Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} powder particles under 25 {mu}m powder particle, increasing Hc as temperature increases. Black-Right-Pointing-Pointer It is proposed that Cu rich regions at inter-grain boundaries could act as exchange decoupling regions contributing to the thermal increase of coercivity. Black-Right-Pointing-Pointer This anomalous thermal dependence points out that tailoring microstructure and size, by controlling the cooling rate of more adequate multiphase systems, could be a promising procedure to develop soft or hard magnets, avoiding Rare Earths metals that is nowadays an important target for the engineering of magnetic materials. - Abstract: In this work, the dependence of the coercive field of Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} gas atomized powder with the temperature for different particle sizes has been studied, observing an anomalous behavior in the under 25 powder particle size fraction. This unusual behavior is related with the microstructure of the powder, and is attributed to the presence of a multiphase magnetic system, with non-magnetic regions decoupling the ferromagnetic domains.

Domain walls at finite temperature

International Nuclear Information System (INIS)

Carvalho, C.A. de; Marques, G.C.; Silva, A.J. da; Ventura, I.

1983-08-01

It is suggested that the phase transition of lambda phi 4 theory as a function of temperature coincides with the spontaneous appearance of domain walls. Based on one-loop calculations, T sub(c) = 4M/√ lambda is estimated as the temperature for these domains to because energetically favored, to be compared with T sub(c) = 4.9M/√ lambda from effective potential calculations (which are performed directly in the broken phase). Domain walls, as well as other Types of fluctuations, disorder the system above T sub(c), leading to =0. The critical exponent for the specific heat above T sub(c) is computed; and α=2/3 + 0 (√ lambda) is obtained. (Author) [pt

Structural studies of CaAl{sub 12}O{sub 19}, SrAl{sub 12}O{sub 19}, La{sub 2/3+δ}Al{sub 12-δ}O{sub 19}, and CaAl{sub 10}NiTiO{sub 19} with the hibonite structure; indications of an unusual type of ferroelectricity

Energy Technology Data Exchange (ETDEWEB)

Li, Jun; Medina, Elena A.; Sleight, Arthur W.; Subramanian, M.A. [Oregon State University, Corvallis, OR (United States). Dept. of Chemistry; Stalick, Judith K. [National Institute of Standards and Technology (NIST), Gaithersburg, MD (United States). Center for Neutron Research

2016-08-01

Various oxides with the hibonite structure were synthesized and structurally analyzed using powder neutron diffraction. The structure of CaAl{sub 12}O{sub 19} at 298 and 11 K shows dipoles that are apparently too dilute to order unless subjected to a suitable electric field. Magnetoplumbites, such as BaFe{sub 12}O{sub 19}, are isostructural with hibonite. These compounds possess ferromagnetic properties, which combined with the electric dipoles may influence multiferroic behavior. Our SrAl{sub 12}O{sub 19} sample showed two distinct hexagonal phases, a major phase with the normal hibonite structure and a minor phase having a closely related structure. Our sample of the defect hibonite phase La{sub 2/3+δ}Al{sub 12-δ}O{sub 19} shows a distinctly higher δ value (0.25) vs. that reported (∝ 0.15) for samples made from the melt. Finally, we used to advantage the negative scattering length of Ti to determine the site occupancies of Ni and Ti in CaAl{sub 10}NiTiO{sub 19}.

Synthesis of compositionally controllable Cu{sub 2}(Sn{sub 1−x}Ge{sub x})S{sub 3} nanocrystals with tunable band gaps

Energy Technology Data Exchange (ETDEWEB)

Liang, Qingshuang, E-mail: lqs671@163.com [Jilin University, State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry (China)

2016-06-15

In this work, we show that compositionally controlled Cu{sub 2}(Sn{sub 1–x}Ge{sub x})S{sub 3} nanocrystals can be successfully synthesized by the hot-injection method through careful tuning the Ge/(Sn+Ge) precursor ratio. The band gaps of the resultant nanocrystals are demonstrated to be linearly tuned from 1.45 to 2.33 eV by adjusting the composition parameter x of the Ge/(Sn+Ge) ratio from 0.0 to 1.0. The crystalline structures of the resultant NCs have been studied by the X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), select area electron diffraction (SAED), and Raman spectroscopy. A ligand exchange procedure is further performed to replace the native ligands on the surface of the NCs with sulfur ions. The photoresponsive behavior indicates the potential use of as-prepared Cu{sub 2}(Sn{sub 1–x}Ge{sub x})S{sub 3} nanocrystals in solar energy conversion systems. The synthesis of compositionally controlled Cu{sub 2}(Sn{sub 1–x}Ge{sub x})S{sub 3} nanocrystals reported herein provides a way for probing the effect of Ge inclusion in the Cu-Sn-S system thin films.

Suppressor of Cytokine Signaling (SOCS 5 utilises distinct domains for regulation of JAK1 and interaction with the adaptor protein Shc-1.

Directory of Open Access Journals (Sweden)

Edmond M Linossi

Full Text Available Suppressor of Cytokine Signaling (SOCS5 is thought to act as a tumour suppressor through negative regulation of JAK/STAT and epidermal growth factor (EGF signaling. However, the mechanism/s by which SOCS5 acts on these two distinct pathways is unclear. We show for the first time that SOCS5 can interact directly with JAK via a unique, conserved region in its N-terminus, which we have termed the JAK interaction region (JIR. Co-expression of SOCS5 was able to specifically reduce JAK1 and JAK2 (but not JAK3 or TYK2 autophosphorylation and this function required both the conserved JIR and additional sequences within the long SOCS5 N-terminal region. We further demonstrate that SOCS5 can directly inhibit JAK1 kinase activity, although its mechanism of action appears distinct from that of SOCS1 and SOCS3. In addition, we identify phosphoTyr317 in Shc-1 as a high-affinity substrate for the SOCS5-SH2 domain and suggest that SOCS5 may negatively regulate EGF and growth factor-driven Shc-1 signaling by binding to this site. These findings suggest that different domains in SOCS5 contribute to two distinct mechanisms for regulation of cytokine and growth factor signaling.

Temperature-dependent anisotropic magnetoresistance inversion behaviors in Fe{sub 3}O{sub 4} films

Energy Technology Data Exchange (ETDEWEB)

Yoon, Kap Soo [Novel Functional Materials and Devices Lab, The Research Institute for Natural Science, Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of); Hong, Jin Pyo, E-mail: jphong@hanyang.ac.kr [Novel Functional Materials and Devices Lab, The Research Institute for Natural Science, Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of); Division of Nano-Scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

2017-02-01

We address the abnormal anisotropic magnetoresistance (AMR) reversal feature of half-metallic polycrystalline Fe{sub 3}O{sub 4} films occurring at a specific temperature. Experimental results revealed a positive to negative MR transition in the Fe{sub 3}O{sub 4} films at 264 K, which reflect the influence of additional domain wall scattering. These features was described by a correlation between domain wall resistance and inversion behavior of AMR with additional domain wall scattering factors. We further describe a possible model based on systematic structural and electrical measurements that employs a temperature-dependent domain wall width and spin diffusion length of the conducting electrons. This model allows for spin-flipping scattering of spin polarized electrons inside a proper domain width.

Fabrication and orientation control of highly cation-ordered epitaxial PbSc{sub 0.5}Ta{sub 0.5}O{sub 3} thin films on Si (100)

Energy Technology Data Exchange (ETDEWEB)

Chopra, Anuj, E-mail: anujchopraiitm@gmail.com [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Saale) (Germany); Faculty of Science and Technology, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Alexe, Marin [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Saale) (Germany); Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Hesse, Dietrich [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Saale) (Germany)

2015-01-28

Highly cation-ordered (100) and (110)-oriented PbSc{sub 0.5}Ta{sub 0.5}O{sub 3} (PST) films were deposited on buffered Si (100) substrates using pulsed laser deposition. Switching of crystal orientation from (100) to (110) was achieved by replacing the Si (100)/ZrO2:Y2O3 (100)/CeO2 (100)/LaNiO3 (100)/PST (100) heterostructure with Si (100)/ZrO2:Y2O3 (YSZ) (100)/SrRuO3 (110)/PST (110). The out-of-plane and in-plane crystal orientation and internal microstructure of (001) and (110) PST films were analyzed in detail by X-ray diffraction, pole figure measurements, and transmission electron microscopy. XRD superstructure reflections indicate that both (100) and (110) PST films are highly cation-ordered and transmission electron microscopy measurements show nano-domains of 15 nm size. The electrical measurements show that the PST films are ferroelectric and that the ferroelectric properties are linked to the microstructure. We have demonstrated the successful integration of PST films on Si substrates with control on growth orientation; this approach can be extended to other oxides to be integrated on silicon substrates for future device applications.

A Novel Sub-pixel Measurement Algorithm Based on Mixed the Fractal and Digital Speckle Correlation in Frequency Domain

Directory of Open Access Journals (Sweden)

Zhangfang Hu

2014-10-01

Full Text Available The digital speckle correlation is a non-contact in-plane displacement measurement method based on machine vision. Motivated by the facts that the low accuracy and large amount of calculation produced by the traditional digital speckle correlation method in spatial domain, we introduce a sub-pixel displacement measurement algorithm which employs a fast interpolation method based on fractal theory and digital speckle correlation in frequency domain. This algorithm can overcome either the blocking effect or the blurring caused by the traditional interpolation methods, and the frequency domain processing also avoids the repeated searching in the correlation recognition of the spatial domain, thus the operation quantity is largely reduced and the information extracting speed is improved. The comparative experiment is given to verify that the proposed algorithm in this paper is effective.

Locomotor Sub-functions for Control of Assistive Wearable Robots

Directory of Open Access Journals (Sweden)

Maziar A. Sharbafi

2017-09-01

Full Text Available A primary goal of comparative biomechanics is to understand the fundamental physics of locomotion within an evolutionary context. Such an understanding of legged locomotion results in a transition from copying nature to borrowing strategies for interacting with the physical world regarding design and control of bio-inspired legged robots or robotic assistive devices. Inspired from nature, legged locomotion can be composed of three locomotor sub-functions, which are intrinsically interrelated: Stance: redirecting the center of mass by exerting forces on the ground. Swing: cycling the legs between ground contacts. Balance: maintaining body posture. With these three sub-functions, one can understand, design and control legged locomotory systems with formulating them in simpler separated tasks. Coordination between locomotor sub-functions in a harmonized manner appears then as an additional problem when considering legged locomotion. However, biological locomotion shows that appropriate design and control of each sub-function simplifies coordination. It means that only limited exchange of sensory information between the different locomotor sub-function controllers is required enabling the envisioned modular architecture of the locomotion control system. In this paper, we present different studies on implementing different locomotor sub-function controllers on models, robots, and an exoskeleton in addition to demonstrating their abilities in explaining humans' control strategies.

Locomotor Sub-functions for Control of Assistive Wearable Robots.

Science.gov (United States)

Sharbafi, Maziar A; Seyfarth, Andre; Zhao, Guoping

2017-01-01

A primary goal of comparative biomechanics is to understand the fundamental physics of locomotion within an evolutionary context. Such an understanding of legged locomotion results in a transition from copying nature to borrowing strategies for interacting with the physical world regarding design and control of bio-inspired legged robots or robotic assistive devices. Inspired from nature, legged locomotion can be composed of three locomotor sub-functions, which are intrinsically interrelated: Stance : redirecting the center of mass by exerting forces on the ground. Swing : cycling the legs between ground contacts. Balance : maintaining body posture. With these three sub-functions, one can understand, design and control legged locomotory systems with formulating them in simpler separated tasks. Coordination between locomotor sub-functions in a harmonized manner appears then as an additional problem when considering legged locomotion. However, biological locomotion shows that appropriate design and control of each sub-function simplifies coordination. It means that only limited exchange of sensory information between the different locomotor sub-function controllers is required enabling the envisioned modular architecture of the locomotion control system. In this paper, we present different studies on implementing different locomotor sub-function controllers on models, robots, and an exoskeleton in addition to demonstrating their abilities in explaining humans' control strategies.

Evolution and sign control of square-wave-like anisotropic magneto-resistance in spatially confined La{sub 0.3}Pr{sub 0.4}Ca{sub 0.3}MnO{sub 3}/LaAlO{sub 3}(001) manganite thin films

Energy Technology Data Exchange (ETDEWEB)

Alagoz, H. S., E-mail: alagoz@ualberta.ca; Jeon, J.; Keating, S.; Chow, K. H., E-mail: khchow@ualberta.ca; Jung, J., E-mail: jjung@ualberta.ca [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada)

2016-04-14

We investigated magneto-transport properties of a compressively strained spatially confined La{sub 0.3}Pr{sub 0.4}Ca{sub 0.3}MnO{sub 3} (LPCMO) thin film micro-bridge deposited on LaAlO{sub 3}. Angular dependence of the magneto-resistance R(θ) of this bridge, where θ is the angle between the magnetic field and the current directions in the film plane, exhibits sharp positive and negative percolation jumps near T{sub MIT}. The sign and the magnitude of these jumps can be tuned using the magnetic field. Such behavior has not been observed in LPCMO micro-bridges subjected to tensile strain, indicating a correlation between the type of the lattice strain, the distribution of electronic domains, and the anisotropic magneto-resistance in spatially confined manganite systems.

In situ transmission electron microscopy studies of microstructure evolution in Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} piezoceramic

Energy Technology Data Exchange (ETDEWEB)

Zakhozheva, Marina

2016-10-21

The purpose of this work is to understand the microstructural features which contribute to the strong electromechanical properties of the lead-free Ba (Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} (BZT-xBCT) piezoelectric ceramic. Detailed conventional transmission electron microscopy (TEM) studies on a broad variety of BZT - xBCT were performed in order to demonstrate the composition dependent structural changes. Moreover, several in situ TEM techniques, including in situ hot- and cold-stage, in situ electric field and in situ electric field with simultaneous cooling, were successfully applied in order to monitor the domain morphology evolution in real time. By means of in situ temperature dependent TEM experiments it was shown that during rhombohedral → orthorhombic → tetragonal phase transition the domain morphology changed according to the crystal structure present. During in situ electric field investigations the displacement of the domain walls and changes in the domain configuration during electrical poling were observed, which indicates a high extrinsic contribution to the piezoelectric response in all BZT - xBCT compositions studied. From the results of in situ electric field TEM experiments with simultaneous cooling, we obtained experimental evidence that the further the composition deviates from the polymorphic phase boundary, the higher the electric field required to fully pole the material.

Composition controlled spin polarization in Co{sub 1-x}Fe{sub x}S{sub 2} alloys

Energy Technology Data Exchange (ETDEWEB)

Leighton, C [Department of Chemical Engineering and Materials Science, University of Minnesota (United States); Manno, M [Department of Chemical Engineering and Materials Science, University of Minnesota (United States); Cady, A [Advanced Photon Source, Argonne National Laboratory (United States); Freeland, J W [Advanced Photon Source, Argonne National Laboratory (United States); Wang, L [Department of Chemical Engineering and Materials Science, University of Minnesota (United States); Umemoto, K [Department of Chemical Engineering and Materials Science, University of Minnesota (United States); Wentzcovitch, R M [Department of Chemical Engineering and Materials Science, University of Minnesota (United States); Chen, T Y [Department of Physics and Astronomy, Johns Hopkins University (United States); Chien, C L [Department of Physics and Astronomy, Johns Hopkins University (United States); Kuhns, P L [National High Magnetic Field Laboratory, Florida State University (United States); Hoch, M J R [National High Magnetic Field Laboratory, Florida State University (United States); Reyes, A P [National High Magnetic Field Laboratory, Florida State University (United States); Moulton, W G [National High Magnetic Field Laboratory, Florida State University (United States); Dahlberg, E D [School of Physics and Astronomy, University of Minnesota (United States); Checkelsky, J [Physics Department, Harvey Mudd College (United States); Eckert, J [Physics Department, Harvey Mudd College (United States)

2007-08-08

The transition metal (TM) chalcogenides of the form TMX{sub 2} (X = S or Se) have been studied for decades due to their interesting electronic and magnetic properties such as metamagnetism and metal-insulator transitions. In particular, the Co{sub 1-x}Fe{sub x}S{sub 2} alloys were the subject of investigation in the 1970s due to general interest in itinerant ferromagnetism. In recent years (2000-present) it has been shown, both by electronic structure calculations and detailed experimental investigations, that Co{sub 1-x}Fe{sub x}S{sub 2} is a model system for the investigation of highly spin polarized ferromagnetism. The radically different electronic properties of the two endpoint compounds (CoS{sub 2} is a narrow bandwidth ferromagnetic metal, while FeS{sub 2} is a diamagnetic semiconductor), in a system forming a substitutional solid solution allows for composition control of the Fermi level relative to the spin split bands, and therefore composition-controlled conduction electron spin polarization. In essence, the recent work has shown that the concept of 'band engineering' can be applied to half-metallic ferromagnets and that high spin polarization can be deliberately engineered. Experiments reveal tunability in both sign and magnitude of the spin polarization at the Fermi level, with maximum values obtained to date of 85% at low temperatures. In this paper we review the properties of Co{sub 1-x}Fe{sub x}S{sub 2} alloys, with an emphasis on properties of relevance to half-metallicity. Crystal structure, electronic structure, synthesis, magnetic properties, transport properties, direct probes of the spin polarization, and measurements of the total density of states at the Fermi level are all discussed. We conclude with a discussion of the factors that influence, or even limit, the spin polarization, along with a discussion of opportunities and problems for future investigation, particularly with regard to fundamental studies of spintronic devices.

Spatially dispersive finite-difference time-domain analysis of sub-wavelength imaging by the wire medium slabs

Science.gov (United States)

Zhao, Yan; Belov, Pavel A.; Hao, Yang

2006-06-01

In this paper, a spatially dispersive finite-difference time-domain (FDTD) method to model wire media is developed and validated. Sub-wavelength imaging properties of the finite wire medium slabs are examined. It is demonstrated that the slab with its thickness equal to an integer number of half-wavelengths is capable of transporting images with sub-wavelength resolution from one interface of the slab to another. It is also shown that the operation of such transmission devices is not sensitive to their transverse dimensions, which can be made even comparable to the wavelength. In this case, the edge diffractions are negligible and do not disturb the image formation.

Study of UO{sub 2}F{sub 2} - H{sub 2}O - HF compounds; Etude des composes UO{sub 2}F{sub 2} - H{sub 2}O - HF

Energy Technology Data Exchange (ETDEWEB)

Neveu, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

We study various compounds resulting from the interaction of UO{sub 2}F{sub 2} with H{sub 2}O and HF (gas), and various triple compounds UO{sub 2}F{sub 2} - H{sub 2}O - HF; the conditions of decomposition and the thermodynamic limits of stability are specified. (author) [French] Nous etudions divers composes formes par reaction de UO{sub 2}F{sub 2} avec H{sub 2}O et HF (gaz) et divers composes triples UO{sub 2}F{sub 2} - H{sub 2}O - HF, en essayant de preciser les decompositions et domaines d'exisfence thermodynamiques de ces corps. (auteur)

Domains within domains and walls within walls: Evidence for polar domains in cryogenic SrTiO.sub.3./sub..

Czech Academy of Sciences Publication Activity Database

Salje, E.K.H.; Aktas, O.; Carpenter, M.A.; Laguta, Valentyn; Scott, J.F.

2013-01-01

Roč. 111, č. 24 (2013), "247603-1"-"247603-5" ISSN 0031-9007 Institutional support: RVO:68378271 Keywords : ferroelectric domains * SrTiO 3 * phase transition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.728, year: 2013

Role of N-methyl-2-pyrrolidone for preparation of Fe{sub 3}O{sub 4}@SiO{sub 2} controlled the shell thickness

Energy Technology Data Exchange (ETDEWEB)

Wee, Sung-Bok [Hanyang University, Division of Materials Science and Engineering (Korea, Republic of); Oh, Hyeon-Cheol [Korea Nano Plus, Inc. (Korea, Republic of); Kim, Tae-Gyun; An, Gye-Seok; Choi, Sung-Churl, E-mail: choi0505@hanyang.ac.kr [Hanyang University, Division of Materials Science and Engineering (Korea, Republic of)

2017-04-15

We developed a simple and novel approach for the synthesis of Fe{sub 3}O{sub 4}@SiO{sub 2} nanoparticles with controlled shell thickness, and studied the mechanism. The introduction of N-methyl-2-pyrrolidone (NMP) led to trapping of monomer nuclei in single shell and controlled the shell thickness. Fe{sub 3}O{sub 4}@SiO{sub 2} controlled the shell thickness, showing a high magnetization value (64.47 emu/g). Our results reveal the role and change in the chemical structure of NMP during the core-shell synthesis process. NMP decomposed to 4-aminobutanoic acid in alkaline condition and decreased the hydrolysis rate of the silica coating process.

Effect of natural homointerfaces on the magnetic properties of pseudomorphic La{sub 0.7}Sr{sub 0.3}MnO{sub 3} thin film: Phase separation vs split domain structure

Energy Technology Data Exchange (ETDEWEB)

Congiu, Francesco [Dipartimento di Fisica e CNISM, Università di Cagliari, S.P. Monserrato-Sestu, km 0.700, I 09042 Monserrato, Cagliari (Italy); Sanna, Carla [Sardegna Ricerche, Laboratorio Energetica Elettrica, VI Strada Ovest - Z.I.Macchiareddu, I 09010 Uta, Cagliari (Italy); Maritato, Luigi [CNR-SPIN, UOS Salerno, I 84084 Fisciano, Salerno (Italy); Dipartimento di Ingegneria dell’Informazione, Ingegneria Elettrica e Matematica Applicata, Università di Salerno, I 84084 Fisciano, Salerno (Italy); Orgiani, Pasquale [CNR-SPIN, UOS Salerno, I 84084 Fisciano, Salerno (Italy); Geddo Lehmann, Alessandra, E-mail: lehmann@dsf.unica.it [Dipartimento di Fisica e CNISM, Università di Cagliari, S.P. Monserrato-Sestu, km 0.700, I 09042 Monserrato, Cagliari (Italy)

2016-12-15

We studied the effect of naturally formed homointerfaces on the magnetic and electric transport behavior of a heavily twinned, 40 nm thick, pseudomorphic epitaxial film of La{sub 0.7}Sr{sub 0.3}MnO{sub 3} deposited by molecular beam epitaxy on ferroelastic LaAlO{sub 3}(001) substrate. As proved by high resolution X-ray diffraction analysis, the lamellar twin structure of the substrate is imprinted in La{sub 0.7}Sr{sub 0.3}MnO{sub 3}. In spite of the pronounced thermomagnetic irreversibility in the DC low field magnetization, spin-glass-like character, possibly related to the structural complexity, was ruled out, on the base of AC susceptibility results. The magnetic characterization indicates anisotropic ferromagnetism, with a saturation magnetization M{sub s} = 3.2 μ{sub B}/Mn, slightly reduced with respect to the fully polarized value of 3.7 μ{sub B}/Mn. The low field DC magnetization vs temperature is non bulklike, with a two step increase in the field cooled M{sub FC}(T) branch and a two peak structure in the zero field cooled M{sub ZFC}(T) one. Correspondingly, two peaks are present in the resistivity vs temperature ρ(T) curve. With reference to the behavior of epitaxial manganites deposited on bicrystal substrates, results are discussed in terms of a two phase model, in which each couple of adjacent ferromagnetic twin cores, with bulklike T{sub C} = 370 K, is separated by a twin boundary with lower Curie point T{sub C} = 150 K, acting as barrier for spin polarized transport. The two phase scenario is compared with the alternative one based on a single ferromagnetic phase with the peculiar ferromagnetic domains structure inherent to twinned manganites films, reported to be split into interconnected and spatially separated regions with in-plane and out-of-plane magnetization, coinciding with twin cores and twin boundaries respectively.

Magnetotransport in La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/CuCr{sub 2}O{sub 4}/Fe{sub 3}O{sub 4} magnetic junctions

Energy Technology Data Exchange (ETDEWEB)

Iwata-Harms, Jodi M.; Suzuki, Yuri [Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Department of Applied Physics and Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Chopdekar, Rajesh V. [Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States); Wong, Franklin J. [Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Nelson-Cheeseman, Brittany B. [Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Jenkins, Catherine A.; Arenholz, Elke [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2015-01-05

We demonstrate distinct magnetic and resistive switching with junction magnetoresistance up to −6% in magnetic tunnel junctions with a CuCr{sub 2}O{sub 4} barrier. Junction magnetoresistance is inversely related to barrier thickness and reveals a maximum at a finite applied bias that converges to zero bias at low temperatures for all barrier thicknesses. The non-monotonic bias dependence is attributed to a charge gap from the Fe{sub 3}O{sub 4} electrode and possible spin filtering from the spin-split conduction band of the ferrimagnetic CuCr{sub 2}O{sub 4} barrier.

Lanthanide-activated Na{sub 5}Gd{sub 9}F{sub 32} nanocrystals precipitated from a borosilicate glass: Phase-separation-controlled crystallization and optical property

Energy Technology Data Exchange (ETDEWEB)

Chen, Daqin, E-mail: dqchen@hdu.edu.cn [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, CAS, Fuzhou 350002 (China); Wan, Zhongyi; Zhou, Yang [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Chen, Yan, E-mail: chenyan@hdu.edu.cn [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Yu, Hua; Lu, Hongwei; Ji, Zhenguo [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Huang, Ping, E-mail: phuang@fjirsm.ac.cn [Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, CAS, Fuzhou 350002 (China)

2015-03-15

Highlights: • Na{sub 5}Gd{sub 9}F{sub 32} nanocrystals embedded glass ceramics were fabricated for the first time. • Such glass ceramics were achieved by phase-separation-controlled crystallization. • Elemental mapping evidenced the segregation of activators into the Na{sub 5}Gd{sub 9}F{sub 32} lattice. • Luminescent color could be tuned by controlling glass crystallization temperature. - Abstract: Lanthanide-activated cubic Na{sub 5}Gd{sub 9}F{sub 32} nanocrystals were precipitated from a borosilicate glass with a specifically designed composition. The precursor glass is already phase-separated after melt-quenching, which is beneficial to the realization of the controllable glass crystallization for affording desirable size, morphology and activator partition. Elemental mapping in the scanning transmission electron microscopy evidenced that the segregation of lanthanide ions into the Na{sub 5}Gd{sub 9}F{sub 32} lattice was in situ formed without the requirement of long-range ionic diffusion. Impressively, such fabricated glass ceramic co-doped with Yb{sup 3+}/Er{sup 3+} ions exhibited intense upconversion luminescence, which was about 500 times higher than that of the precursor glass, and its luminescent color could be easily tuned from red to green by controlling glass crystallization temperature. It is anticipated that such phase-separation synthesis strategy with precise control over nanostructure of glass ceramics offer a great opportunity to design other highly transparent nanocomposites with a wide range of tunable optical properties.

Landau-Ginzburg description of anomalous properties of novel room temperature multiferroics Pb(Fe{sub 1/2}Ta{sub 1/2}){sub x}(Zr{sub 0.53}Ti{sub 0.47}){sub 1-x}O{sub 3} and Pb(Fe{sub 1/2}Nb{sub 1/2}){sub x}(Zr{sub 0.53}Ti{sub 0.47}){sub 1−x}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Glinchuk, Maya D.; Eliseev, Eugene A. [Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, Krjijanovskogo 3, 03142 Kyiv (Ukraine); Morozovska, Anna N., E-mail: anna.n.morozovska@gmail.com [Institute of Physics, National Academy of Sciences of Ukraine, 46, pr. Nauky, 03028 Kyiv (Ukraine)

2016-01-14

Landau-Ginzburg thermodynamic formalism is used for the description of the anomalous ferroelectric, ferromagnetic, and magnetoelectric properties of Pb(Fe{sub 1/2}Ta{sub 1/2}){sub x}(Zr{sub 0.53}Ti{sub 0.47}){sub 1−x}O{sub 3} and Pb(Fe{sub 1/2}Nb{sub 1/2}){sub x}(Zr{sub 0.53}Ti{sub 0.47}){sub 1−x}O{sub 3} micro-ceramics. We calculated temperature, composition, and external field dependences of ferroelectric, ferromagnetic, and antiferromagnetic phases transition temperatures, remanent polarization, magnetization, hysteresis loops, dielectric permittivity, and magnetoelectric coupling. Special attention was paid to the comparison of developed theory with experiments. It appeared possible to describe adequately main experimental results including a reasonable agreement between the shape of calculated and measured hysteresis loops and remnant polarization. Since Landau-Ginzburg thermodynamic formalism appertains to single domain properties of a ferroic, we did not aim to describe quantitatively the coercive field under the presence of realistic poly-domain switching. Information about linear and nonlinear magnetoelectric coupling coefficients was extracted from the experimental data. From the fitting of experimental data with theoretical formula, we obtained the composition dependence of Curie-Weiss constant that is known to be inversely proportional to harmonic (linear) dielectric stiffness, as well as the strong nonlinear dependence of anharmonic parameters in free energy. Keeping in mind the essential influence of these parameters on multiferroic properties, the obtained results open the way to govern practically all the material properties with the help of suitable composition choice. A forecast of the strong enough influence of antiferrodistortive order parameter on the transition temperatures and so on the phase diagrams and properties of multiferroics are made on the basis of the developed theory.

Optimal Control of Heterogeneous Systems with Endogenous Domain of Heterogeneity

International Nuclear Information System (INIS)

Belyakov, Anton O.; Tsachev, Tsvetomir; Veliov, Vladimir M.

2011-01-01

The paper deals with optimal control of heterogeneous systems, that is, families of controlled ODEs parameterized by a parameter running over a domain called domain of heterogeneity. The main novelty in the paper is that the domain of heterogeneity is endogenous: it may depend on the control and on the state of the system. This extension is crucial for several economic applications and turns out to rise interesting mathematical problems. A necessary optimality condition is derived, where one of the adjoint variables satisfies a differential inclusion (instead of equation) and the maximization of the Hamiltonian takes the form of “min-max”. As a consequence, a Pontryagin-type maximum principle is obtained under certain regularity conditions for the optimal control. A formula for the derivative of the objective function with respect to the control from L ∞ is presented together with a sufficient condition for its existence. A stylized economic example is investigated analytically and numerically.

Optical network control plane for multi-domain networking

DEFF Research Database (Denmark)

Manolova, Anna Vasileva

This thesis focuses on multi-domain routing for traffice engineering and survivability support in optical transport networks under the Generalized Multi-Protocol Label Switching (GMPLS) control framework. First, different extensions to the Border Gateway Protocol for multi-domain Traffic...... process are not enough for efficient TE in mesh multi-domain networks. Enhancing the protocol with multi-path dissemination capability, combined with the employment of an end-to-end TE metric proves to be a highly efficient solution. Simulation results show good performance characteristics of the proposed...... is not as essential for improved network performance as the length of the provided paths. Second, the issue of multi-domain survivability support is analyzed. An AS-disjoint paths is beneficial not only for resilience support, but also for facilitating adequate network reactions to changes in the network, which...

Low-complexity linewidth-tolerant time domain sub-symbol optical phase noise suppression in CO-OFDM systems.

Science.gov (United States)

Hong, Xuezhi; Hong, Xiaojian; Zhang, Junwei; He, Sailing

2016-03-07

Two linewidth-tolerant optical phase noise suppression algorithms, non-decision aided sub-symbol optical phase noise suppression (NDA-SPS) and partial-decision aided sub-symbol optical phase noise suppression (PDA-SPS), based on low-complexity time domain sub-symbol processing are proposed for coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems. High accuracy carrier phase estimation is achieved in the NDA-SPS algorithm without decision error propagation. Compared with NDA-SPS, partial-decision aided estimation is introduced in PDA-SPS to reduce the pilot-overhead by half, yet only a small performance degradation is induced. The principles and computational complexities of the proposed algorithms are theoretically analyzed. By adopting specially designed comb-type pilot subcarriers, multiplier-free observation-based matrix generation is realized in the proposed algorithms. Computationally intensive discrete Fourier transform (DFT) or inverse DFT (IDFT) operations, which are usually carried out in other high-performance inter-carrier-interference (ICI) mitigation algorithms multiple times, are completely avoided. Compared with several other sub-symbol algorithms, the proposed algorithms with lower complexities offer considerably larger laser linewidth tolerances as demonstrated by Monte-Carlo simulations. Numerical analysis verifies that the optimal performance of PDA-SPS can be achieved with moderate numbers of sub-symbols.

Distinct Cell Guidance Pathways Controlled by the Rac and Rho GEF Domains of UNC-73/TRIO in Caenorhabditis elegans

Science.gov (United States)

Marcus-Gueret, Nancy; Schmidt, Kristopher L.; Stringham, Eve G.

2012-01-01

The cytoskeleton regulator UNC-53/NAV2 is required for both the anterior and posterior outgrowth of several neurons as well as that of the excretory cell while the kinesin-like motor VAB-8 is essential for most posteriorly directed migrations in Caenorhabditis elegans. Null mutations in either unc-53 or vab-8 result in reduced posterior excretory canal outgrowth, while double null mutants display an enhanced canal extension defect, suggesting the genes act in separate pathways to control this posteriorly directed outgrowth. Genetic analysis of putative interactors of UNC-53 or VAB-8, and cell-specific rescue experiments suggest that VAB-8, SAX-3/ROBO, SLT-1/Slit, and EVA-1 are functioning together in the outgrowth of the excretory canals, while UNC-53 appears to function in a parallel pathway with UNC-71/ADAM. The known VAB-8 interactor, the Rac/Rho GEF UNC-73/TRIO operates in both pathways, as isoform specific alleles exhibit enhancement of the phenotype in double-mutant combination with either unc-53 or vab-8. On the basis of these results, we propose a bipartite model for UNC-73/TRIO activity in excretory canal extension: a cell autonomous function that is mediated by the Rho-specific GEF domain of the UNC-73E isoform in conjunction with UNC-53 and UNC-71 and a cell nonautonomous function that is mediated by the Rac-specific GEF domain of the UNC-73B isoform, through partnering with VAB-8 and the receptors SAX-3 and EVA-1. PMID:21996675

Approximate controllability of the Navier-Stokes system in unbounded domains

International Nuclear Information System (INIS)

Shorygin, P O

2003-01-01

The question of the approximate controllability for the 2- and the 3-dimensional Navier-Stokes system defined in the exterior of a bounded domain ω or in the entire space is studied. It is shown that one can find boundary controls or locally distributed controls (having support in a prescribed bounded domain) defined on the right-hand side of the system such that in prescribed time the solution of the Navier-Stokes system becomes arbitrarily close to an arbitrary prescribed divergence-free vector field

Site-selective doping and superconductivity in (La/sub 1-//sub y/Pr/sub y/)(Ba/sub 2-//sub x/La/sub x/)Cu3O/sub 7+//sub δ/

International Nuclear Information System (INIS)

Mitzi, D.B.; Feffer, P.T.; Newsam, J.M.; Webb, D.J.; Klavins, P.; Jacobson, A.J.; Kapitulnik, A.

1988-01-01

Samples in the quaternary system (La/sub 1-//sub y/Pr/sub y/)(Ba/sub 2-//sub x/La/sub x/)Cu 3 O/sub 7+//sub δ/ have been prepared and characterized using x-ray and neutron diffraction, thermogravimetric analysis, and transport and magnetic measurements. Pr substitutes on the oxygen-depleted La layers for y>0.0, while La substitutes on the Ba sites for x>0.0. The effect of doping on each site is inferred to be primarily local, affecting immediately adjacent Cu-O layers. The similar suppression of superconductivity that accompanies doping on each of the two distinct sites apparently correlates with the degree of oxidation of the Cu-O sheets (and not the chains), indicating that the sheets support the high temperature superconductivity. Comparison of orthorhombic and tetragonal samples with similar Ba:La ratios (and y = 0) demonstrates that the orthorhombic phase yields the largest Meissner signals and highest transition temperatures in the La(Ba/sub 2-//sub x/La/sub x/)Cu 3 O/sub 7+//sub δ/ system

Disentangling the impact of artistic creativity on creative thinking, working memory, attention and intelligence:Evidence for domain-specific relationships with a new self-report questionnaire

Directory of Open Access Journals (Sweden)

Katrin Lunke

2016-07-01

Full Text Available The goal of the present study was to take a new look at the relationship between creativity and cognitive functioning. Based on models that have postulated domain- and sub-domain-structures for different forms of creativity, like scientific, technical or artistic creativity with cognitive functions as important basis, we developed a new questionnaire. The Artistic Creativity Domains Compendium (ACDC assesses interest, ability and performance in a distinct way for different domains of artistic creativity. We present the data of 270 adults tested with the ACDC, standard tests of divergent and convergent thinking, and tests of cognitive functions. We present fine-grained analyses on the internal and external validity of the ACDC and on the relationships between creativity, working memory, attention, and intelligence. Our results indicate domain-specific associations between creativity and attention as well as working memory. We conclude that the ACDC is a valid instrument to assess artistic creativity and that a fine-grained analysis reveals distinct patterns of relationships between separate domains of creativity and cognition.

Disentangling the Impact of Artistic Creativity on Creative Thinking, Working Memory, Attention, and Intelligence: Evidence for Domain-Specific Relationships with a New Self-Report Questionnaire

Science.gov (United States)

Lunke, Katrin; Meier, Beat

2016-01-01

The goal of the present study was to take a new look at the relationship between creativity and cognitive functioning. Based on models that have postulated domain- and sub-domain-structures for different forms of creativity, like scientific, technical or artistic creativity with cognitive functions as important basis, we developed a new questionnaire. The Artistic Creativity Domains Compendium (ACDC) assesses interest, ability and performance in a distinct way for different domains of artistic creativity. We present the data of 270 adults tested with the ACDC, standard tests of divergent and convergent thinking, and tests of cognitive functions. We present fine-grained analyses on the internal and external validity of the ACDC and on the relationships between creativity, working memory, attention, and intelligence. Our results indicate domain-specific associations between creativity and attention as well as working memory. We conclude that the ACDC is a valid instrument to assess artistic creativity and that a fine-grained analysis reveals distinct patterns of relationships between separate domains of creativity and cognition. PMID:27516745

Disentangling the Impact of Artistic Creativity on Creative Thinking, Working Memory, Attention, and Intelligence: Evidence for Domain-Specific Relationships with a New Self-Report Questionnaire.

Science.gov (United States)

Lunke, Katrin; Meier, Beat

2016-01-01

The goal of the present study was to take a new look at the relationship between creativity and cognitive functioning. Based on models that have postulated domain- and sub-domain-structures for different forms of creativity, like scientific, technical or artistic creativity with cognitive functions as important basis, we developed a new questionnaire. The Artistic Creativity Domains Compendium (ACDC) assesses interest, ability and performance in a distinct way for different domains of artistic creativity. We present the data of 270 adults tested with the ACDC, standard tests of divergent and convergent thinking, and tests of cognitive functions. We present fine-grained analyses on the internal and external validity of the ACDC and on the relationships between creativity, working memory, attention, and intelligence. Our results indicate domain-specific associations between creativity and attention as well as working memory. We conclude that the ACDC is a valid instrument to assess artistic creativity and that a fine-grained analysis reveals distinct patterns of relationships between separate domains of creativity and cognition.

Local rhombohedral symmetry in Tb{sub 0.3}Dy{sub 0.7}Fe{sub 2} near the morphotropic phase boundary

Energy Technology Data Exchange (ETDEWEB)

Ma, Tianyu, E-mail: maty@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Key Laboratory of Novel Materials for Information Technology of Zhejiang Province, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027 (China); Ferroic Physics Group, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Ibaraki (Japan); Liu, Xiaolian; Pan, Xingwen; Li, Xiang; Jiang, Yinzhu; Yan, Mi, E-mail: mse-yanmi@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Key Laboratory of Novel Materials for Information Technology of Zhejiang Province, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027 (China); Li, Huiying; Fang, Minxia [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, Xi' an Jiaotong University, Xi' an 710049 (China); Ren, Xiaobing, E-mail: ren.xiaobing@nims.go.jp [Ferroic Physics Group, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Ibaraki (Japan); Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, Xi' an Jiaotong University, Xi' an 710049 (China)

2014-11-10

The recently reported morphotropic phase boundary (MPB) in a number of giant magnetostrictive materials (GMMs) has drawn considerable interest to the local symmetry/structure near MPB region of these materials. In this letter, by in-situ X-ray diffraction and AC magnetic susceptibility measurements, we show that Tb{sub 0.3}Dy{sub 0.7}Fe{sub 2}, the typical composition of Terfenol-D GMMs, has coexistence of rhombohedral and tetragonal phases over a wide temperature range in the vicinity of MPB. High resolution transmission electron microscopy provides direct evidence for local rhombohedral symmetry of the ferromagnetic phase and reveals regular-shaped nanoscale domains below 10 nm. The nano-sized structural/magnetic domains are hierarchically inside a single micron-sized stripe-like domain with the same average magnetization direction. Such domain structures are consistent with the low magnetocrystalline anisotropy and easy magnetic/structural domain switching under magnetic field, thus generating large magnetostriction at low field.

Final Research Performance Report - Small Molecular Associative Carbon Dioxide (CO<sub>2sub>) Thickeners for Improved Mobility Control

Energy Technology Data Exchange (ETDEWEB)

Enick, Robert M. [Univ. of Pittsburgh, PA (United States)

2017-12-31

The initial objective of this project was to promote the application of a CO<sub>2sub> thickener for improved mobility control during CO<sub>2sub> EOR based on solubility tests, viscosity tests, and core floods. Ultimately, it was demonstrated that the CO<sub>2sub>-soluble polymeric thickeners are much better suited for use a CO<sub>2sub>-soluble conformance control agents for diverting the flow of CO<sub>2sub> away from thief zones. Our team generated several effective small molecule CO<sub>2sub> thickeners with ARPA-e funding. Unfortunately, none of these small molecule thickeners could dissolve in CO<sub>2sub> without the addition of unacceptably large amounts of hexane or toluene as a co-solvent Therefore none were viable candidates for the core flooding studies associated with NETL award. Therefore during the entire core flood testing program associated with this NETL award, our team used only the most promising polymeric CO<sub>2sub> thickener, a polyfluoroacrylate (PFA). In order to produce an environmentally benign polymer, the monomer used to make the new polymers used in this study was a fluoroacrylate that contains only six fluorinated carbons. We verified CO<sub>2sub> solubility with a phase behavior cell. The thickening potential of all polymer samples was substantiated with a falling ball viscometer and a falling cylinder viscometer at Pitt. Two different viscometers were used to determine the increase in CO<sub>2sub> viscosity that could be achieved via the dissolution of PFA. Praxair, which has an interest in thickening CO<sub>2sub> for pilot EOR projects and for waterless hydraulic fracturing, agreed to measure the viscosity of CO<sub>2sub>-PFA solutions at no cost to the project. Falling cylinder viscometery was conducted at Pitt in our windowed high pressure phase behavior cell. Both apparatuses indicated that at very low shear rates the CO<sub>2sub> viscosity increased by a factor of roughly 3.5 when 1wt% PFA was

Domain wall propagation in Fe-rich amorphous microwires

Energy Technology Data Exchange (ETDEWEB)

Panina, L.V. [School of Comp. and Math., Univ. of Plymouth, Drake Circus, PL4 AA, Plymouth (United Kingdom); Ipatov, M.; Zhukova, V. [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20018 San Sebastian (Spain); Zhukov, A., E-mail: arkadi.joukov@ehu.es [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20018 San Sebastian (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain)

2012-05-01

The domain wall (DW) propagation in magnetically bistable Fe{sub 74}Si{sub 11}B{sub 13}C{sub 2} amorphous microwires with metallic nucleus diameters of 12-16 {mu}m has been investigated in order to explain high DW velocities observed in Sixtus-Tonks like experiments. In micrometric wires, the boundary between two head-to-head domains is very elongated. The DW mobility normal to the wall surface is reduced by the domain aspect ratio and is in the range of a few m/s/Oe in the linear regime. The experimental results in the viscous regime could be quantitatively explained in terms of the domain length and normal mobility limited by the eddy currents and spin relaxation losses.

Evaporation induced diameter control in fiber crystal growth by micro-pulling-down technique: Bi{sub 4}Ge{sub 3}O{sub 12}

Energy Technology Data Exchange (ETDEWEB)

Chani, V.; Lebbou, K.; Hautefeuille, B.; Tillement, O. [Physical Chemistry of Luminescent Materials, Claude Bernard Lyon1 University, CNRS UMR 5620, Bat. A. Kastler, 10 rue Ampere, 69622 Villeurbanne Cedex (France); Fourmigue, J.M. [FiberCryst, 23 rue Royale, F-69001 Lyon (France)

2006-10-15

Diameter self-control was established in Bi{sub 4}Ge{sub 3}O{sub 12} fiber crystal growth by micro-pulling-down technique. In accordance with Bi{sub 2}O{sub 3}-GeO{sub 2} phase diagram, the diameter was controlled due to compensation of solidification with evaporation of volatile Bi{sub 2}O{sub 3} self-flux charged into the crucible with excess. The crucibles had capillary channels of 310 or 650 {mu}m in outer diameter. The crystals up to 400 mm long and 50-300 {mu}m in diameter were grown at pulling-down rates of 0.04-1.00 mm/min. The melt composition and the pulling rate were generally only two parameters determining solidification rate. As a result, crystals with uniform ({+-} 10%) diameter and aspect ratio up to 10{sup 4} were produced without automation of the process. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Impulse voltage control of continuously tunable bipolar resistive switching in Pt/Bi{sub 0.9}Eu{sub 0.1}FeO{sub 3}/Nb-doped SrTiO{sub 3} heterostructures

Energy Technology Data Exchange (ETDEWEB)

Wei, Maocai; Liu, Meifeng; Wang, Xiuzhang [Hubei Normal University, Institute for Advanced Materials, and School of Physics and Electronic Science, Huangshi (China); Li, Meiya; Zhu, Yongdan; Zhao, Meng; Zhang, Feng; Xie, Shuai [Wuhan University, School of Physics and Technology, and Key Laboratory of Artificial Micro/Nano Structures of the Ministry of Education, Wuhan (China); Hu, Zhongqiang [Northeastern University, Department of Electrical and Computer Engineering, Boston, MA (United States); Liu, Jun-Ming [Nanjing University, Laboratory of Solid State Microstructures, Nanjing (China)

2017-03-15

Epitaxial Bi{sub 0.9}Eu{sub 0.1}FeO{sub 3} (BEFO) thin films are deposited on Nb-doped SrTiO{sub 3} (NSTO) substrates by pulsed laser deposition to fabricate the Pt/BEFO/NSTO (001) heterostructures. These heterostructures possess bipolar resistive switching, where the resistances versus writing voltage exhibits a distinct hysteresis loop and a memristive behavior with good retention and anti-fatigue characteristics. The local resistive switching is confirmed by the conductive atomic force microscopy (C-AFM), suggesting the possibility to scale down the memory cell size. The observed memristive behavior could be attributed to the ferroelectric polarization effect, which modulates the height of potential barrier and width of depletion region at the BEFO/NSTO interface. The continuously tunable resistive switching behavior could be useful to achieve non-volatile, high-density, multilevel random access memory with low energy consumption. (orig.)

Radiometric control for P/sub 2/O/sub 5/ content in Polpinsky are deposit phosphorites

Energy Technology Data Exchange (ETDEWEB)

Belyakov, M A; Berenshtein, M L; Startsev, V K; Akindinov, V A

1977-01-01

Results are cited of laboratory research into the possibility of radiometric determination of P/sub 2/O/sub 5/ in phosphorites of Polpinsky deposit. On the basis of the studies performed, a plant and methods have been developed for the continuous control of P/sub 2/O/sub 5/ content in ore. The plant has been tested at the Bryansk phosphorite works. The accuracy of analysis is 0.8 percent.

Synthesis of mixed-valent {alpha}- and {beta}-NaFe{sub 2}O{sub 3} polymorphs under controlled partial oxygen pressure

Energy Technology Data Exchange (ETDEWEB)

Bruno, Shaun R.; Blakely, Colin K. [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Poltavets, Viktor V., E-mail: poltavets@chemistry.msu.edu [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States)

2012-08-15

Synthesis of mixed valent compounds, especially when multiple polymorphs exist, requires careful control of the preparation conditions. {alpha}- and {beta}-NaFe{sub 2}O{sub 3} polymorphs were synthesized under controlled partial oxygen pressure (pO{sub 2}). pO{sub 2} regions of stability at 850 Degree-Sign C were determined for both phases for the first time. A modified oxygen buffer method was developed for the facile preparation of mixed valent oxides under controlled pO{sub 2}. {beta}-NaFe{sub 2}O{sub 3} is the only known n=2 member of the AM{sub n}O{sub n+1} (A=alkali metal, M=3d metal) rock-salt related homolog series with layered cation ordering. The possibility of new members of the homolog series with other 3d metals is considered. - Graphical abstract: Schematic section of phase composition vs. partial O{sub 2} pressure diagram at 850 Degree-Sign C for Na/Fe=1/2 and structure models of {alpha}- and {beta}-NaFe{sub 2}O{sub 3}. Highlights: Black-Right-Pointing-Pointer {alpha}- and {beta}-NaFe{sub 2}O{sub 3} polymorphs were synthesized under controlled oxygen pressure. Black-Right-Pointing-Pointer {beta}-NaFe{sub 2}O{sub 3} has rock-salt related structure with layered cation ordering. Black-Right-Pointing-Pointer Existence of the rock-salt related homolog series AM{sub n}O{sub n+1} is discussed.

Structural and catalytic characterization of mechanical mixtures of Pt/WOx-ZrO{sub 2} and Al{sub 2}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Contreras, J.L., E-mail: jlcl@correo.azc.uam.m [Universidad Autonoma Metropolitana-Azcapotzalco, CBI, Dpto. Energia, Av. Sn. Pablo 180, Col. Reynosa, C.P. 02200, Mexico, DF (Mexico); Fuentes, G.A. [Universidad Autonoma Metropolitana-Iztapalapa, CBI, Depto. de IPH C.P. 09340, Mexico, DF (Mexico); Navarrete, J.; Vazquez, A. [Instituto Mexicano del Petroleo, IBP, Ger. de Catalizadores, Eje Central Lazaro Cardenas No. 152, C.P. 07300, Mexico, DF (Mexico); Zeifert, B.; Salmones, J. [Instituto Politecnico Nacional Mexico, ESIQIE, Laboratorio de Catalisis y Materiales, C.P. 07738, Mexico, DF (Mexico); Nuno, L. [Universidad Autonoma Metropolitana-Azcapotzalco, CBI, Dpto. Energia, Av. Sn. Pablo 180, Col. Reynosa, C.P. 02200, Mexico, DF (Mexico)

2010-04-16

The effect of the Bronsted/Lewis acid ratio on isomerization of n-heptane using Al{sub 2}O{sub 3} as a source of Lewis acidity and WOx/ZrO{sub 2} as a source of Bronsted and Lewis acidity was studied and controlled using mechanical mixtures of these solids. These mixtures were characterized by surface area, infrared spectroscopy of pyridine, X-ray diffraction and Raman spectroscopy. It was found that the presence of W=O stretching mode which was consistent with the presence of oxotungstate species which were the precursors of the acid sites. It was found out that as the oxotungstate structures increased, the selectivity to n-heptane isomers increased while the hydrocracking and dehydrocyclization selectivity decreased. The presence of Bronsted acidity of the WOx/ZrO{sub 2} domains, the increase of Knudsen diffusivity and the loss of Pt metallic area by strong interaction of the Pt with the WOx/ZrO{sub 2} explain this catalytic behavior.

Controllable solvothermal synthesis and photocatalytic properties of complex (oxy)fluorides K{sub 2}TiOF{sub 4}, K{sub 3}TiOF{sub 5}, K{sub 7}Ti{sub 4}O{sub 4}F{sub 7} and K{sub 2}TiF{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Sheng Jie [Division of Nanomaterials and Nanochemistry, Hefei National Laboratory for Physical Sciences at Microscale, Hefei, Anhui 230026 (China); Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China); Tang Kaibin, E-mail: kbtang@ustc.edu.cn [Division of Nanomaterials and Nanochemistry, Hefei National Laboratory for Physical Sciences at Microscale, Hefei, Anhui 230026 (China); Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China); Cheng Wei; Wang Junli; Nie Yanxiang; Yang Qing [Division of Nanomaterials and Nanochemistry, Hefei National Laboratory for Physical Sciences at Microscale, Hefei, Anhui 230026 (China); Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2009-11-15

Complex (oxy)fluorides K{sub 2}TiF{sub 6}, K{sub 2}TiOF{sub 4}, K{sub 3}TiOF{sub 5} and K{sub 7}Ti{sub 4}O{sub 4}F{sub 7} have been successfully synthesized for the first time through a controllable solvothermal route involving different solvents, for example, methanol, methanol-H{sub 2}O and methanol-H{sub 2}O{sub 2}. The as-prepared products were characterized by X-ray powder diffraction, N{sub 2} surface area adsorption, scanning electron microscope, Fourier transform infrared spectroscopy, UV-vis absorption spectra and X-ray fluorescence. The influences of reaction conditions such as the ratio of methanol to H{sub 2}O{sub 2} or methanol to H{sub 2}O, reaction temperature on the phase, crystallizability and purity of the (oxy)fluorides products were discussed in detail. Meanwhile, the photocatalytic behaviors of the as-prepared K{sub 2}TiF{sub 6}, K{sub 2}TiOF{sub 4}, K{sub 3}TiOF{sub 5} and K{sub 7}Ti{sub 4}O{sub 4}F{sub 7} were evaluated by degradation of rhodamine B molecules, and the results showed that all of the products possessed photocatalytic activities in the order of K{sub 2}TiOF{sub 4} > K{sub 2}TiF{sub 6} > K{sub 7}Ti{sub 4}O{sub 4}F{sub 7} > K{sub 3}TiOF{sub 5} at room temperature under the UV light.

Enhanced electrical properties of pulsed laser-deposited CuIn{sub 0.7}Ga{sub 0.3}Se{sub 2} thin films via processing control

Energy Technology Data Exchange (ETDEWEB)

Jo, Yeon Hwa; Mohanty, Bhaskar Chandra; Cho, Yong Soo [Department of Materials Science and Engineering, Yonsei University, Seoul (Korea, Republic of)

2010-12-15

Polycrystalline CuIn{sub 0.7}Ga{sub 0.3}Se{sub 2} thin films were prepared on soda-lime glass substrates using pulsed laser deposition (PLD) with various process parameters such as laser energy, repetition rate and substrate temperature. It was confirmed that there existed a limited laser energy, i.e. less than 300 mJ, to get phase pure CIGS thin films at room temperature. Particularly, even at room temperature, distinct crystalline CIGS phase was observed in the films. Crystallinity of the films improved with increasing substrate temperature as evidenced by the decrease of FWHM from 0.65 degto 0.54 deg. Slightly Cu-rich surface with Cu{sub 2-x}Se phase was confirmed to exist by Raman spectra, depending on substrate temperature. Improved electrical properties, i.e., carrier concentration of {proportional_to}10{sup 18} cm{sup -3} and resistivity of 10{sup -1}{omega} cm at higher substrate temperature for the optimal CIGS films are assumed to be induced by the potential contributions from highly crystallized thin films, existence of Cu{sub 2-x}Se phase and diffusion of Na from substrates to films. (author)

Controlled hydrothermal synthesis of BiO{sub x}Cl{sub y}/BiO{sub m}I{sub n} composites exhibiting visible-light photocatalytic degradation of crystal violet

Energy Technology Data Exchange (ETDEWEB)

Jiang, Yu-Rou; Lin, Ho-Pan [Department of Science Application and Dissemination, National Taichung University of Education, Taichung 403, Taiwan, ROC (China); Chung, Wen-Hsin [Department of Plant Pathology, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Dai, Yong-Ming [Department of Science Application and Dissemination, National Taichung University of Education, Taichung 403, Taiwan, ROC (China); Lin, Wan-Yu [Department of Plant Pathology, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Chen, Chiing-Chang, E-mail: ccchen@ms3.ntcu.edu.tw [Department of Science Application and Dissemination, National Taichung University of Education, Taichung 403, Taiwan, ROC (China)

2015-02-11

Highlights: • This is the first report on a series of BiO{sub x}Cl{sub y}/BiO{sub m}I{sub n} heterojunctions. • The BiO{sub x}Cl{sub y}/BiO{sub m}I{sub n} composition was controlled by adjusting the growth parameters. • The BiO{sub x}Cl{sub y}/BiO{sub m}I{sub n} were indirect semiconductors with a 1.78–2.95-eV bandgap. • The new photocatalysts removed CV at a much faster rate than TiO{sub 2}. • Mechanisms were determined by separating the intermediates using HPLC-MS. - Abstract: A series of BiO{sub x}Cl{sub y}/BiO{sub m}I{sub n} composites were prepared using autoclave hydrothermal methods. The composition and morphologies of the BiO{sub x}Cl{sub y}/BiO{sub m}I{sub n} composites were controlled by adjusting the experimental conditions: the reaction pH value, temperature, and KCl/KI molar ratio. The products were characterized using X-ray diffraction, scanning electron microscopy-electron dispersive X-ray spectroscopy, UV–vis diffuse reflectance spectroscopy, Brunauer–Emmett–Teller specific surface areas, cathodoluminescence, high-resolution transmission electron microscopy, and high-resolution X-ray photoelectron spectroscopy. The photocatalytic efficiencies of composite powder suspensions were evaluated by monitoring the crystal violet (CV) concentrations. In addition, the quenching effects of various scavengers indicated that the reactive O{sub 2}·{sup −} played a major role, and OH· or h{sup +} played a minor role in CV degradation. The intermediates formed during the decomposition process were isolated, identified, and characterized using high performance liquid chromatography-photodiode array-electrospray ionization-mass spectrometry to elucidate the CV decomposition mechanism.

Local Peltier-effect-induced reversible metal–insulator transition in VO{sub 2} nanowires

Energy Technology Data Exchange (ETDEWEB)

Takami, Hidefumi; Kanki, Teruo, E-mail: kanki@sanken.osaka-u.ac.jp, E-mail: h-tanaka@sanken.osaka-u.ac.jp; Tanaka, Hidekazu, E-mail: kanki@sanken.osaka-u.ac.jp, E-mail: h-tanaka@sanken.osaka-u.ac.jp [Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

2016-06-15

We report anomalous resistance leaps and drops in VO{sub 2} nanowires with operating current density and direction, showing reversible and nonvolatile switching. This event is associated with the metal–insulator phase transition (MIT) of local nanodomains with coexistence states of metallic and insulating phases induced by thermoelectric cooling and heating effects. Because the interface of metal and insulator domains has much different Peltier coefficient, it is possible that a significant Peltier effect would be a source of the local MIT. This operation can be realized by one-dimensional domain configuration in VO{sub 2} nanowires because one straight current path through the electronic domain-interface enables theoretical control of thermoelectric effects. This result will open a new method of reversible control of electronic states in correlated electron materials.

Theoretical insight into the distinct photocatalytic activity between NiO{sub x} and CoO{sub x} loaded Ta{sub 3}N{sub 5} photocatalyst

Energy Technology Data Exchange (ETDEWEB)

Sun, Kenan; Li, Yuanyuan; Zhang, Qing [Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan, 475004 (China); Wang, Li, E-mail: chemwangl@henu.edu.cn [Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan, 475004 (China); Zhang, Jinglai, E-mail: zhangjinglai@henu.edu.cn [Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan, 475004 (China); Zhou, Xin, E-mail: zhouxin@dlu.edu.cn [College of Environment and Chemical Engineering, Dalian University, Dalian, 116622 (China)

2017-05-31

Highlights: • Highly active photocatalytic Ta{sub 3}N{sub 5} loaded with CoO{sub x} and NiO{sub x}. • Exploring the stable structure and the electronic properties by DFT calculations. • Investigating the behavior of water adsorption on the surface of photocatalytic. - Abstract: Experiments found that cocatalysts play an important role in influencing the efficiency of photocatalysis and photoelectrochemical water splitting. However, how to choose proper cocatalysts in certain photocatalytic system is still a challenging question. In this work, the first-principles density functional theory is employed to explore two photocatalysts with different photocatalytic activity, CoO{sub x} and NiO{sub x} loaded Ta{sub 3}N{sub 5}, including finding the stable structure of metal oxide adsorbed surface, analyzing the electronic properties, and investigating the behavior of water adsorption. Our results indicate that the structural match between cluster and surface and less distortion of interfacial structure are benefit to the stability of the whole system. Water dissociation tends to occur at the interface between metal oxide cluster and Ta{sub 3}N{sub 5} surface. Combining observations in experiments with our calculated results, we propose that the obvious difference of photocatalytic activities in CoO{sub x}/Ta{sub 3}N{sub 5} and NiO{sub x}/Ta{sub 3}N{sub 5} is possibly related to whether there are impurity states located in the middle of band gap, which has adverse effect on the separation of photo-generated electrons and holes.

A novel method for stoichiometric reduction of (U{sub 3}O{sub 8},PuO{sub 2}) and its controlled oxidation using microwave

Energy Technology Data Exchange (ETDEWEB)

Singh, G., E-mail: gitendars@barctara.gov.in [Advanced Fuel Fabrication Facility (AFFF), Bhabha Atomic Research Centre, Tarapur, 401 502 (India); Kumar, Pradeep [Integrated Fuel Fabrication Facility, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Aher, S.; Purohit, P.; Khot, P.M. [Advanced Fuel Fabrication Facility (AFFF), Bhabha Atomic Research Centre, Tarapur, 401 502 (India); Prakash, Amrit [Radio-Metallurgy Division, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Das, D.K.; Behere, P.G.; Afzal, Mohd [Advanced Fuel Fabrication Facility (AFFF), Bhabha Atomic Research Centre, Tarapur, 401 502 (India)

2016-10-15

We report a process for stoichiometric reduction of U{sub 3}O{sub 8} and (U{sub 3}O{sub 8},PuO{sub 2}) mixed oxide powders using an indigenously developed 2.4 GHz microwave processing system. The process parameters were optimized by interpreting reduction kinetic curves at a temperature which is 150 °C lower than the conventional reduction. The process improved the sinterability of the powder which was evaluated in terms of average particle size, BET specific surface area and bulk density. A quick method for controlled oxidation of the reduced powder to incorporate a controlled amount of hyper-stoichiometry was demonstrated by modifying the same reduction process. The percent reduction was measured experimentally using O:(U + Pu) ratio. The X-ray diffraction analysis confirmed the various phases present. The process is novel considering shorter processing cycle, lower temperature processing, improved powder properties, energy efficiency and cost effectiveness. - Highlights: • A process for stoichiometric reduction of (U{sub 3}O{sub 8},PuO{sub 2}) was demonstrated using 2.4 GHz microwave. • A simple and quick method for obtaining controlled hyper-stoichiometry in the reduced powder was successfully demonstrated. • The process is novel relative to conventional methods in terms of time and energy economy and sinter-activity.

An agent-based negotiation approach for balancing multiple coupled control domains

DEFF Research Database (Denmark)

Umair, Aisha; Clausen, Anders; Jørgensen, Bo Nørregaard

2015-01-01

Solving multi-objective multi-issue negotiation problems involving interdependent issues distributed among multiple control domains is inherent to most non-trivial cyber-physical systems. In these systems, the coordinated operation of interconnected subsystems performing autonomous control....... The proposed approach can solve negotiation problems with interdependent issues across multiple coupled control domains. We demonstrate our approach by solving a coordination problem where a Combined Heat and Power Plant must allocate electricity for three commercial greenhouses to ensure the required plant...

Electronic transport in organometallic perovskite CH{sub 3}NH{sub 3}PbI{sub 3}: The role of organic cation orientations

Energy Technology Data Exchange (ETDEWEB)

Berdiyorov, G. R., E-mail: gberdiyorov@qf.org.qa; El-Mellouhi, F.; Madjet, M. E.; Rashkeev, S. N. [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha (Qatar); Alharbi, F. H. [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha (Qatar); College of Science and Engineering, Hamad Bin Khalifa University, Doha (Qatar)

2016-02-01

Density functional theory in combination with the nonequilibrium Green's function formalism is used to study the electronic transport properties of methylammonium lead-iodide perovskite CH{sub 3}NH{sub 3}PbI{sub 3}. Electronic transport in homogeneous ferroelectric and antiferroelectric phases, both of which do not contain any charged domain walls, is quite similar. The presence of charged domain wall drastically (by about an order of magnitude) enhances the electronic transport in the lateral direction. The increase of the transmission originates from the smaller variation of the electrostatic potential profile along the charged domain walls. This fact may provide a tool for tuning transport properties of such hybrid materials by manipulating molecular cations having dipole moment.

Domain decomposition techniques for boundary elements application to fluid flow

CERN Document Server

Brebbia, C A; Skerget, L

2007-01-01

The sub-domain techniques in the BEM are nowadays finding its place in the toolbox of numerical modellers, especially when dealing with complex 3D problems. We see their main application in conjunction with the classical BEM approach, which is based on a single domain, when part of the domain needs to be solved using a single domain approach, the classical BEM, and part needs to be solved using a domain approach, BEM subdomain technique. This has usually been done in the past by coupling the BEM with the FEM, however, it is much more efficient to use a combination of the BEM and a BEM sub-domain technique. The advantage arises from the simplicity of coupling the single domain and multi-domain solutions, and from the fact that only one formulation needs to be developed, rather than two separate formulations based on different techniques. There are still possibilities for improving the BEM sub-domain techniques. However, considering the increased interest and research in this approach we believe that BEM sub-do...

Integrated dry NO{sub x}/SO{sub 2} emissions control system: integrated system test report

Energy Technology Data Exchange (ETDEWEB)

Smith, R.A.; Muzio, L.J. [Fossil Energy Research Corp., Laguna Hills, CA (United States); Hunt, T. [Public Service Co. of Colorado, Denver, CO (United States)

1997-04-01

The DOE sponsored Integrated Dry NO{sub x}/SO{sub 2} Emissions Control System Program, is a Clean Coal Technology III demonstration, being conducted by Public Service Company of Colorado. The test site is Arapahoe Generating Station Unit 4, a 100 MWe, down-fired utility boiler burning a low-sulfur Western coal. The project goal is to demonstrate up to 70 percent reductions in NO{sub x} and SO{sub 2} emissions through the integration of: (1) down-fired low NO{sub x} burners with overfire air; (2) Selective Non-Catalytic Reduction (SNCR) for additional NO{sub x} removal; and (3) Dry Sorbent Injection (DSI) and duct humidification for SO{sub 2} removal. This report documents the final phase of the test program, in which the overall performance of the integrated system was evaluated. Previous testing has shown that the goal of 70 percent NO{sub x} removal was easily achieved with the combination of low-NO{sub x} burners, overfire air, and urea-based SNCR. Similarly, the ability of the sodium-based DSI system to achieve 70 percent SO{sub 2} removal was also demonstrated previously. The integrated tests demonstrated the synergistic benefit of operating the SNCR and sodium-based DSI systems concurrently. With the automatic control system set to limit the NH{sub 3} emissions to less than 8 ppm, the NO{sub 2} emissions from the sodium-based DSI system were reduced by nominally 50 percent compared to operation with the DSI system alone. Comparably, the combined operation reduced NH{sub 3} emissions, as reflected by a higher urea injection rate for a fixed NH{sub 3} emission limit. With combined DSI and SNCR operation, an ammonia odor problem was encountered around the Unit 4 ash silo (this did not occur with the SNCR system operated alone at comparable NH{sub 3} slip levels). This odor problem is attributed to the sodium changing the rate at which NH{sub 3} is released from the ash when it is wetted for truck transport to the disposal site.

Frequency domain performance analysis of nonlinearly controlled motion systems

NARCIS (Netherlands)

Pavlov, A.V.; Wouw, van de N.; Pogromski, A.Y.; Heertjes, M.F.; Nijmeijer, H.

2007-01-01

At the heart of the performance analysis of linear motion control systems lie essential frequency domain characteristics such as sensitivity and complementary sensitivity functions. For a class of nonlinear motion control systems called convergent systems, generalized versions of these sensitivity

New mechanism of structuring associated with the quasi-merohedral twinning by an example of Ca{sub 1–x}La{sub x}F{sub 2+x} ordered solid solutions

Energy Technology Data Exchange (ETDEWEB)

Maksimov, S. K., E-mail: maksimov-sk@comtv.ru [National Research University MIET (Laboratory of EMI) (Russian Federation); Maksimov, K. S., E-mail: kuros@rambler.ru [Institute VIMI FSUE (Russian Federation); Sukhov, N. D. [Moscow State University (Faculty of Physics) (Russian Federation); Lovygin, M. V. [National Research University MIET (Laboratory of EMI) (Russian Federation)

2015-10-15

Merohedry is considered an inseparable property of atomic structures, and uses for the refinement of structural data in a process of correct determination of structure of compounds. Transformation of faulty structures stimulated by decreasing of systemic cumulative energy leads to generation of merohedral twinning type. Ordering is accompanied by origin of antiphase domains. If ordering belongs to the CuAu type, it is accompanied by tetragonal distortions along different (100) directions. If a crystal consists of mosaic of nanodimensional antiphase domains, the conjugation of antiphase domains with different tetragonality leads to monoclinic distortions, at that, conjugated domains are distorted mirrorly. Similar system undergoes further transformation by means of quasi-merohedral twinning. As a result of quasi-merohedry, straight-lines of lattices with different monoclinic distortions are transformed into coherent lattice broken-lines providing minimization of the cumulative energy. Structuring is controlled by regularities of the self-organization. However stochasticity of ordering predetermines the origin areas where few domains with different tetragonality contact which leads to the origin of faulty fields braking regular passage of structuring. Resulting crystal has been found structurally non-uniform, furthermore structural non-uniformity permits identifying elements and stages of a process. However there is no precondition preventing arising the origin of homogenous states. Effect has been revealed in Ca{sub 1–x}La{sub x}F{sub 2+x} solid solution, but it can be expected that distortions of regular alternation of ions similar to antiphase domains can be obtained in non-equilibrium conditions in compounds and similar effect of the quasi-merohedry can falsify results of structural analysis.

Sequential injection of domain walls into ferroelectrics at different bias voltages: Paving the way for “domain wall memristors”

Energy Technology Data Exchange (ETDEWEB)

Whyte, J. R.; McQuaid, R. G. P.; Einsle, J. F.; Gregg, J. M., E-mail: m.gregg@qub.ac.uk [Centre for Nanostructured Media (CNM), School of Maths and Physics, Queen' s University Belfast, University Road, Belfast BT7 1NN (United Kingdom); Ashcroft, C. M. [Centre for Nanostructured Media (CNM), School of Maths and Physics, Queen' s University Belfast, University Road, Belfast BT7 1NN (United Kingdom); Department of Physics, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Canalias, C. [Department of Applied Physics, Royal Institute of Technology, Roslagstullsbacken 21, 10691 Stockholm (Sweden); Gruverman, A. [Department of Physics and Astronomy, University of Nebraska Lincoln, Nebraska 68588–0299 (United States)

2014-08-14

Simple meso-scale capacitor structures have been made by incorporating thin (∼300 nm) single crystal lamellae of KTiOPO{sub 4} (KTP) between two coplanar Pt electrodes. The influence that either patterned protrusions in the electrodes or focused ion beam milled holes in the KTP have on the nucleation of reverse domains during switching was mapped using piezoresponse force microscopy imaging. The objective was to assess whether or not variations in the magnitude of field enhancement at localised “hot-spots,” caused by such patterning, could be used to both control the exact locations and bias voltages at which nucleation events occurred. It was found that both the patterning of electrodes and the milling of various hole geometries into the KTP could allow controlled sequential injection of domain wall pairs at different bias voltages; this capability could have implications for the design and operation of domain wall electronic devices, such as memristors, in the future.

Magnetic and electrical studies on La{sub 0.4}Sm{sub 0.1}Ca{sub 0.5}MnO{sub 3} charge ordered manganite

Energy Technology Data Exchange (ETDEWEB)

Krichene, A., E-mail: akramkri@hotmail.fr [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Université de Sfax, B. P. 1171, 3000 Sfax (Tunisia); Solanki, P.S. [Department of Physics, Saurashtra University, Rajkot 360005 (India); Venkateshwarlu, D. [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017 (India); Rayaprol, S. [UGC-DAE Consortium for Scientific Research, Mumbai Centre, B.A.R.C. Campus, Mumbai 400085 (India); Ganesan, V. [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017 (India); Boujelben, W. [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Université de Sfax, B. P. 1171, 3000 Sfax (Tunisia); Kuberkar, D.G. [Department of Physics, Saurashtra University, Rajkot 360005 (India)

2015-05-01

We have reported in this work the effect of the partial substitution of lanthanum by samarium on the structural, electrical and magnetic properties of La{sub 0.5}Ca{sub 0.5}MnO{sub 3}. The magnetic study indicated that substitution promotes charge ordering and weakens ferromagnetism. Below T{sub C}=123 K, the compound La{sub 0.4}Sm{sub 0.1}Ca{sub 0.5}MnO{sub 3} is a mixture of ferromagnetic and charge ordered antiferromagnetic domains. Between T{sub C} and T{sub CO}=215 K, the structure is paramagnetic with the presence of antiferromagnetic domains. The fractions of the coexisting magnetic phases are highly dependent on the applied magnetic field value. Resistivity measurements reveal the presence of an insulating-metal transition at T{sub ρ}=123 K. The equality between T{sub C} and T{sub ρ} indicates the presence of a correlation between magnetization and resistivity. For only 1 T applied field, we have reported a colossal value of magnetoresistance reaching 73% around T{sub C}. The origin of this high value is attributed to phase separation phenomenon. - Highlights: • Sm doping enhances charge ordering and weakens ferromagnetism in La{sub 0.5}Ca{sub 0.5}MnO{sub 3.} • Colossal magnetoresistance (73%) is recorded at 123 K for only 1 T applied field. • Phase separation is responsible for the magnetic and the magnetoresistive behavior.

Polarization fluctuation behavior of lanthanum substituted Bi{sub 4}Ti{sub 3}O{sub 12} thin films

Energy Technology Data Exchange (ETDEWEB)

Zhong, Ni; Xiang, Ping-Hua, E-mail: phxiang@ee.ecnu.edu.cn; Zhang, Yuan-Yuan; Wu, Xing; Tang, Xiao-Dong; Yang, Ping-Xiong; Duan, Chun-Gang; Chu, Jun-Hao [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai 200241 (China)

2015-09-14

Polarization fluctuation behavior of lanthanum substituted Bi{sub 4}Ti{sub 3}O{sub 12} (Bi{sub 4−x}La{sub x}Ti{sub 3}O{sub 12}, BLT) ferroelectric thin films has been examined. Remnant polarization exhibits an initial increase (P{sub up}, 1–10{sup 6} cycles) and a subsequent decrease (P{sub down}, 10{sup 6}–10{sup 9} cycles) with switching cycles, whereas the dielectric constant exhibits a continuous decrease. By careful investigations on the effect of switching frequency and annealing atmosphere on the polarization fluctuation characteristics, we propose that this polarization fluctuation characteristic of BLT films is attributed to the competition between domain pinning and passive layer growing effect, due to the redistribution of oxygen vacancy related defect under external applied field. P{sub up} behavior is dominated by the unpinning of pinned domain, while P{sub down} behavior is dominated by the reduction of applied field on BLT bulk layer, due to the growing of the passive layer between BLT and Pt electrode. By assuming the dielectric constant and initial thickness of passive layer, the passive layer was estimated to be about 2–5 times thicker than the initial state after 10{sup 9} cycling.

A pre-registered naturalistic observation of within domain mental fatigue and domain-general depletion of self-control.

Directory of Open Access Journals (Sweden)

Daniel Randles

Full Text Available Self-control is often believed to operate as if it were a finite, domain-general resource. However, recent attempts to demonstrate this under transparent conditions have failed to yield positive results. In the current study, we monitor two groups of students (N1 = 8,867, N2 = 8,754 over separate 17-week intervals with 24-hour coverage, as they engage in voluntary learning and self-testing using an online program. We use daily behavior to assess whether time-of-day effects support domain-general theories of self-control. Additionally, we assess whether mental fatigue emerges within task during prolonged persistent effort. Results reveal within-task fatigue emerges within an hour on-task. However, there is a negligible effect on ability throughout the day. Additionally, time-of-day has no detrimental effect on motivation; rather there is a strong tendency to increase learning time at night. Results are consistent with theories indicating people lose motivation within a specific task, but at odds with theories that argue for a domain-general self-control resource.

Domain decomposition methods for core calculations using the MINOS solver

International Nuclear Information System (INIS)

Guerin, P.; Baudron, A. M.; Lautard, J. J.

2007-01-01

Cell by cell homogenized transport calculations of an entire nuclear reactor core are currently too expensive for industrial applications, even if a simplified transport (SPn) approximation is used. In order to take advantage of parallel computers, we propose here two domain decomposition methods using the mixed dual finite element solver MINOS. The first one is a modal synthesis method on overlapping sub-domains: several Eigenmodes solutions of a local problem on each sub-domain are taken as basis functions used for the resolution of the global problem on the whole domain. The second one is an iterative method based on non-overlapping domain decomposition with Robin interface conditions. At each iteration, we solve the problem on each sub-domain with the interface conditions given by the solutions on the close sub-domains estimated at the previous iteration. For these two methods, we give numerical results which demonstrate their accuracy and their efficiency for the diffusion model on realistic 2D and 3D cores. (authors)

S3QL: A distributed domain specific language for controlled semantic integration of life sciences data

Directory of Open Access Journals (Sweden)

de Lencastre Hermínia

2011-07-01

Full Text Available Abstract Background The value and usefulness of data increases when it is explicitly interlinked with related data. This is the core principle of Linked Data. For life sciences researchers, harnessing the power of Linked Data to improve biological discovery is still challenged by a need to keep pace with rapidly evolving domains and requirements for collaboration and control as well as with the reference semantic web ontologies and standards. Knowledge organization systems (KOSs can provide an abstraction for publishing biological discoveries as Linked Data without complicating transactions with contextual minutia such as provenance and access control. We have previously described the Simple Sloppy Semantic Database (S3DB as an efficient model for creating knowledge organization systems using Linked Data best practices with explicit distinction between domain and instantiation and support for a permission control mechanism that automatically migrates between the two. In this report we present a domain specific language, the S3DB query language (S3QL, to operate on its underlying core model and facilitate management of Linked Data. Results Reflecting the data driven nature of our approach, S3QL has been implemented as an application programming interface for S3DB systems hosting biomedical data, and its syntax was subsequently generalized beyond the S3DB core model. This achievement is illustrated with the assembly of an S3QL query to manage entities from the Simple Knowledge Organization System. The illustrative use cases include gastrointestinal clinical trials, genomic characterization of cancer by The Cancer Genome Atlas (TCGA and molecular epidemiology of infectious diseases. Conclusions S3QL was found to provide a convenient mechanism to represent context for interoperation between public and private datasets hosted at biomedical research institutions and linked data formalisms.

Size-effect in layered ferrielectric CuInP<sub>2sub>S>6sub>

Energy Technology Data Exchange (ETDEWEB)

Chyasnavichyus, Marius [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). The Center for Nanophase Materials Sciences; Susner, Michael A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Ievlev, Anton V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). The Center for Nanophase Materials Sciences; Eliseev, Eugene A. [National Academy of Sciences of Ukraine (NASU), Kiev (Ukraine). Inst. for Problems of Materials Science; Kalinin, Sergei V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). The Center for Nanophase Materials Sciences; Balke, Nina [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). The Center for Nanophase Materials Sciences; Morozovska, Anna N. [National Academy of Sciences of Ukraine (NASU), Kiev (Ukraine). Inst. of Physics; McGuire, Michael A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Maksymovych, Petro [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). The Center for Nanophase Materials Sciences

2016-10-24

In this paper, we report on polarization switching properties of thin flakes of van der Waals ferrielectric CuInP<sub>2sub>S>6sub>. We observe mesoscale polarization domains, ferroelectric switching, and the Curie temperature above 299 K down to a thickness of ~50 nm. However, the electromechanical response is progressively suppressed below 50 nm, and vanishes at room temperature at a thickness of ~10 nm. Though larger than a single layer, 10 nm is still a very small value compared to the expectations for an intrinsic ferroelectric semiconductor. We therefore propose a model for a doped surface layer that screens spontaneous polarization in this material. The charges in the screening layer may also participate in secondary chemical reactions, which may explain domain pinning observed in thermal cycling of the flakes above the Curie temperature. At the same time, ferroelectric switching is intertwined with ionic diffusion, resulting in erratic and damaging switching at room temperature. Finally, owing to much stronger temperature dependence of ionic diffusion, the two phenomena can be decoupled allowing more reliable switching to be obtained at low temperatures.

Substrate and growth related microstructural and magnetic properties in La{sub 0.67}Sr{sub 0.33}MnO{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Hawley, M.E.; Brown, G.W.; Kwon, C.; Jia, Q.

1998-12-31

Ambient observation of magnetic domain structures by magnetic force microscopy (MFM) in La{sub 0.67}Sr{sub 0.33}MnO{sub 3} films has not yet been clearly correlated with stresses induced by kinetic or thermodynamic growth processes or the compressive (LaAlO{sub 3}) or tensile (SrTiO{sub 3}) nature of the film-substrate lattice mismatch. Although domain-like magnetic structures have been seen in some as-grown films and related to substrate-induced stress and film thickness, no magnetic structure has been seen for other films grown under similar conditions on the same pair of substrates. In this study the authors have grown films over a range of temperatures by pulsed-laser deposition, using the above substrates, to determine the relationship between growth and stress-induced magnetic structures. Results from scanning tunneling, atomic force, and magnetic force microscopies, measurements of temperature-dependent magnetization and structure-dependent coercivity show the relationship between growth and magnetic properties. Maze-like domain structures, with separations between 150 nm and 200 nm, were only observed for the thicker films grown at the highest temperature, 800 C. Application of an in-plane magnetic field converted these domain structures to stripe-like domains whose spacing and out of plane component decreased as the field was increased.

Two-dimensional sub-half-wavelength atom localization via controlled spontaneous emission.

Science.gov (United States)

Wan, Ren-Gang; Zhang, Tong-Yi

2011-12-05

We propose a scheme for two-dimensional (2D) atom localization based on the controlled spontaneous emission, in which the atom interacts with two orthogonal standing-wave fields. Due to the spatially dependent atom-field interaction, the position probability distribution of the atom can be directly determined by measuring the resulting spontaneously emission spectrum. The phase sensitive property of the atomic system leads to quenching of the spontaneous emission in some regions of the standing-waves, which significantly reduces the uncertainty in the position measurement of the atom. We find that the frequency measurement of the emitted light localizes the atom in half-wavelength domain. Especially the probability of finding the atom at a particular position can reach 100% when a photon with certain frequency is detected. By increasing the Rabi frequencies of the driving fields, such 2D sub-half-wavelength atom localization can acquire high spatial resolution.

Mycoplasma hyopneumoniae and Mycoplasma flocculare differential domains from orthologous surface proteins induce distinct cellular immune responses in mice.

Science.gov (United States)

Leal, Fernanda Munhoz Dos Anjos; Virginio, Veridiana Gomes; Martello, Carolina Lumertz; Paes, Jéssica Andrade; Borges, Thiago J; Jaeger, Natália; Bonorino, Cristina; Ferreira, Henrique Bunselmeyer

2016-07-15

Mycoplasma hyopneumoniae and Mycoplasma flocculare are two genetically close species found in the swine respiratory tract. Despite their similarities, while M. hyopneumoniae is the causative agent of porcine enzootic pneumonia, M. flocculare is a commensal bacterium. Genomic and transcriptional comparative analyses so far failed to explain the difference in pathogenicity between these two species. We then hypothesized that such difference might be, at least in part, explained by amino acid sequence and immunological or functional differences between ortholog surface proteins. In line with that, it was verified that approximately 85% of the ortholog surface proteins from M. hyopneumoniae 7448 and M. flocculare present one or more differential domains. To experimentally assess possible immunological implications of this kind of difference, the extracellular differential domains from one pair of orthologous surface proteins (MHP7448_0612, from M. hyopneumoniae, and MF_00357, from M. flocculare) were expressed in E. coli and used to immunize mice. The recombinant polypeptides (rMHP61267-169 and rMF35767-196, respectively) induced distinct cellular immune responses. While, rMHP61267-169 induced both Th1 and Th2 responses, rMF35767-196 induced just an early pro-inflammatory response. These results indicate that immunological properties determined by differential domains in orthologous surface protein might play a role in pathogenicity, contributing to elicit specific and differential immune responses against each species. Copyright © 2016 Elsevier B.V. All rights reserved.

Structure of the fully ferroelectric/fully ferroelastic orthohombic room-temperature phase of cobalt bromine boracite, Co[sub 3]B[sub 7]O[sub 13]Br and nickel chlorine boracite, Ni[sub 3]B[sub 7]O[sub 13]Cl

Energy Technology Data Exchange (ETDEWEB)

Kubel, F; Mao, S Y; Schmid, H [Dept. de Chemie Minerale, Analytique et Applique, Geneva Univ. (Switzerland)

1992-07-15

The X-ray crystal structures of optically controlled single-domain crystals of fully ferroelectric/fully ferroelastic cobalt bromine boracite, Co[sub 3]B[sub 7]O[sub 13]Br (Co-Br) at 298 K [M[sub r] = 540.38, orthorhombic, Pca2[sub 1], a = 8.5614 (2), b = 8.5657 (2), c = 12.1196 (3) A, V = 888.78 (4) A[sup 3], Z = 4, D[sub x] = 4.04 Mg m[sup -3], [lambda](Mo K[alpha]) = 0.7107 A, [mu] = 10.61 mm[sup -1], F(000) = 1020, R = 7.0, wR = 5.4%, 2824 reflections] and of nickel chlorine boracite, Ni[sub 3]B[sub 7]O[sub 13]Cl (Ni-Cl) at 298 K [M[sub r] = 495.25, orthorhombic, Pca2[sub 1], a = 8.5105 (4), b = 8.4984 (4), c = 12.0324 (5) A, V = 870.25 (7) A[sup 3], Z = 4, D[sub x] = 3.78 Mg m[sup -3], [lambda](Mo K[alpha]) = 0.7107 A, [mu] = 6.8 mm[sup -1], F(000) = 960, R = 3.5, wR = 3.1%, 2082 reflections] are reported. The metal surroundings of Co-Br and Ni-Cl were analyzed in detail and show two metal sites (Co2, Co3; Ni2, Ni3) with chemically similar environments and one metal site (Co1; Ni1) with a different environment. Six B atoms have a tetrahedral or slightly distorted tetrahedral coordination, whereas one B atom (B4) has triangular surroundings in both compounds. (orig.).

Structural chemistry and magnetic properties of the perovskite SrLa{sub 2}Ni{sub 2}TeO{sub 9}

Energy Technology Data Exchange (ETDEWEB)

Paria Sena, Robert; Hadermann, Joke [EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Chin, Chun-Mann; Hunter, Emily C. [Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Battle, Peter D., E-mail: peter.battle@chem.ox.ac.uk [Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom)

2016-11-15

A polycrystalline sample of SrLa{sub 2}Ni{sub 2}TeO{sub 9} has been synthesized using a standard ceramic method and characterized by neutron diffraction, magnetometry and electron microscopy. The compound adopts a monoclinic, perovskite-like structure with space group P2{sub 1}/n and unit cell parameters a=5.6008(1), b=5.5872(1), c=7.9018(2) Å, β=90.021(6)° at room temperature. The two crystallographically-distinct B sites are occupied by Ni{sup 2+} and Te{sup 6+} in ratios of 83:17 and 50:50. Both ac and dc magnetometry suggest that the compound is a spin glass below 35 K but the neutron diffraction data show that some regions of the sample are antiferromagnetic. Electron microscopy revealed twinning on a nanoscale and local variations in composition. These defects are thought to be responsible for the presence of two distinct types of antiferromagnetic ordering. - Highlights: • Coexistence of spin-glass and ordered phases. • Local inhomogeneity despite long-range inhomogeneity. • Contrasting magnetic properties of SrLa{sub 2}Ni{sub 2}TeO{sub 9} and La{sub 3}Ni{sub 2}SbO{sub 9}.

Sub-cellular force microscopy in single normal and cancer cells

Energy Technology Data Exchange (ETDEWEB)

Babahosseini, H. [VT MEMS Laboratory, The Bradley Department of Electrical and Computer Engineering, Blacksburg, VA 24061 (United States); Carmichael, B. [Nonlinear Intelligent Structures Laboratory, Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487-0276 (United States); Strobl, J.S. [VT MEMS Laboratory, The Bradley Department of Electrical and Computer Engineering, Blacksburg, VA 24061 (United States); Mahmoodi, S.N., E-mail: nmahmoodi@eng.ua.edu [Nonlinear Intelligent Structures Laboratory, Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487-0276 (United States); Agah, M., E-mail: agah@vt.edu [VT MEMS Laboratory, The Bradley Department of Electrical and Computer Engineering, Blacksburg, VA 24061 (United States)

2015-08-07

This work investigates the biomechanical properties of sub-cellular structures of breast cells using atomic force microscopy (AFM). The cells are modeled as a triple-layered structure where the Generalized Maxwell model is applied to experimental data from AFM stress-relaxation tests to extract the elastic modulus, the apparent viscosity, and the relaxation time of sub-cellular structures. The triple-layered modeling results allow for determination and comparison of the biomechanical properties of the three major sub-cellular structures between normal and cancerous cells: the up plasma membrane/actin cortex, the mid cytoplasm/nucleus, and the low nuclear/integrin sub-domains. The results reveal that the sub-domains become stiffer and significantly more viscous with depth, regardless of cell type. In addition, there is a decreasing trend in the average elastic modulus and apparent viscosity of the all corresponding sub-cellular structures from normal to cancerous cells, which becomes most remarkable in the deeper sub-domain. The presented modeling in this work constitutes a unique AFM-based experimental framework to study the biomechanics of sub-cellular structures. - Highlights: • The cells are modeled as a triple-layered structure using Generalized Maxwell model. • The sub-domains include membrane/cortex, cytoplasm/nucleus, and nuclear/integrin. • Biomechanics of corresponding sub-domains are compared among normal and cancer cells. • Viscoelasticity of sub-domains show a decreasing trend from normal to cancer cells. • The decreasing trend becomes most significant in the deeper sub-domain.

Sub-cellular force microscopy in single normal and cancer cells

International Nuclear Information System (INIS)

Babahosseini, H.; Carmichael, B.; Strobl, J.S.; Mahmoodi, S.N.; Agah, M.

2015-01-01

This work investigates the biomechanical properties of sub-cellular structures of breast cells using atomic force microscopy (AFM). The cells are modeled as a triple-layered structure where the Generalized Maxwell model is applied to experimental data from AFM stress-relaxation tests to extract the elastic modulus, the apparent viscosity, and the relaxation time of sub-cellular structures. The triple-layered modeling results allow for determination and comparison of the biomechanical properties of the three major sub-cellular structures between normal and cancerous cells: the up plasma membrane/actin cortex, the mid cytoplasm/nucleus, and the low nuclear/integrin sub-domains. The results reveal that the sub-domains become stiffer and significantly more viscous with depth, regardless of cell type. In addition, there is a decreasing trend in the average elastic modulus and apparent viscosity of the all corresponding sub-cellular structures from normal to cancerous cells, which becomes most remarkable in the deeper sub-domain. The presented modeling in this work constitutes a unique AFM-based experimental framework to study the biomechanics of sub-cellular structures. - Highlights: • The cells are modeled as a triple-layered structure using Generalized Maxwell model. • The sub-domains include membrane/cortex, cytoplasm/nucleus, and nuclear/integrin. • Biomechanics of corresponding sub-domains are compared among normal and cancer cells. • Viscoelasticity of sub-domains show a decreasing trend from normal to cancer cells. • The decreasing trend becomes most significant in the deeper sub-domain

Spatial Domain Adaptive Control of Nonlinear Rotary Systems Subject to Spatially Periodic Disturbances

Directory of Open Access Journals (Sweden)

Yen-Hsiu Yang

2012-01-01

Full Text Available We propose a generic spatial domain control scheme for a class of nonlinear rotary systems of variable speeds and subject to spatially periodic disturbances. The nonlinear model of the rotary system in time domain is transformed into one in spatial domain employing a coordinate transformation with respect to angular displacement. Under the circumstances that measurement of the system states is not available, a nonlinear state observer is established for providing the estimated states. A two-degree-of-freedom spatial domain control configuration is then proposed to stabilize the system and improve the tracking performance. The first control module applies adaptive backstepping with projected parametric update and concentrates on robust stabilization of the closed-loop system. The second control module introduces an internal model of the periodic disturbances cascaded with a loop-shaping filter, which not only further reduces the tracking error but also improves parametric adaptation. The overall spatial domain output feedback adaptive control system is robust to model uncertainties and state estimated error and capable of rejecting spatially periodic disturbances under varying system speeds. Stability proof of the overall system is given. A design example with simulation demonstrates the applicability of the proposed design.

Ferroelectric domain engineering by focused infrared femtosecond pulses

Energy Technology Data Exchange (ETDEWEB)

Chen, Xin; Shvedov, Vladlen; Sheng, Yan, E-mail: yan.sheng@anu.edu.au [Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Karpinski, Pawel [Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Wroclaw University of Technology, Wybrzeze Wyspianskiego, Wroclaw (Poland); Koynov, Kaloian [Max-Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz (Germany); Wang, Bingxia; Trull, Jose; Cojocaru, Crina [Departament de Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, Rambla Sant Nebridi, 08222 Terrassa, Barcelona (Spain); Krolikowski, Wieslaw [Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Texas A& M University at Qatar, Doha (Qatar)

2015-10-05

We demonstrate infrared femtosecond laser-induced inversion of ferroelectric domains. This process can be realised solely by using tightly focused laser pulses without application of any electric field prior to, in conjunction with, or subsequent to the laser irradiation. As most ferroelectric crystals like LiNbO{sub 3}, LiTaO{sub 3}, and KTiOPO{sub 4} are transparent in the infrared, this optical poling method allows one to form ferroelectric domain patterns much deeper inside a ferroelectric crystal than by using ultraviolet light and hence can be used to fabricate practical devices. We also propose in situ diagnostics of the ferroelectric domain inversion process by monitoring the Čerenkov second harmonic signal, which is sensitive to the appearance of ferroelectric domain walls.

Carbon-13 NMR study of switch variant anti-dansyl antibodies: Antigen binding and domain-domain interactions

Energy Technology Data Exchange (ETDEWEB)

Kato, Koichi; Matsunaga, Chigusa; Odaka, Asano; Yamato, Sumie; Takaha, Wakana; Shimada, Ichio; Arata, Yoji (Univ. of Tokyo (Japan))

1991-07-02

A {sup 13}C NMR study is reported of switch variant anti-dansyl antibodies, which possess the identical V{sub H}, V{sub L}, and C{sub L} domains in conjunction with highly homologous but not identical heavy-chain constant regions. Each of the antibodies has been selectively labeled with {sup 13}C at the carbonyl carbon of Trp, Tyr, His, or Cys residue by growing hybridoma cells in serum-free medium. Spectral assignments have been made by folowing the procedure described previously for the switch variant antibodies labeled with (1-{sup 13}C)Met. On the basis of the spectral data collected for the antibodies and their proteolytic fragments, the authors discuss how {sup 13}C NMR spectroscopy can be used for the structural analyses of antigen binding and also of domain-domain interactions in the antibody molecule.

Three-dimensional organization of micronuclei induced by colchicine in PtK sub 1 cells

Energy Technology Data Exchange (ETDEWEB)

Geraud, G.; Laquerriere, F.; Masson, C.; Arnoult, J.; Labidi, B.; Hernandez-Verdun, D. (Univ. Pierre et Marie Curie, Paris (France))

1989-03-01

In PtK{sub 1} cells micronucleated by colchicine, the authors previously demonstrated that some micronuclei contain a single chromosome. Here, they investigated interphase chromosome organization in micronucleated PtK{sub 1} cells using conventional electron microscopy and three-dimensional computer reconstruction. The distribution of micronuclei was not always polarized, but in some cells they formed a ring. When this occurred, centrioles and Golgi apparatus were located inside the ring. On freeze-fracture replicas, they observed that nuclear pore distinction among the micronuclei was heterogeneous, and on thin sections some micronuclei displayed an incomplete nuclear envelope, with gaps in the double membrane and areas without lamina or condensed chromatin. By autoradiography, they showed that the fibrillar dots were not sites of active transcription. They applied three dimensional reconstruction to one micronucleated cell containing 22 micronuclei whose size indicated that each micronucleus probably contained one chromosome. In this cell they demonstrated that only the smallest micronuclei had an incomplete nuclear envelope. The presence in micronuclei of either nucleoli or fibrillar dots was found to be mutually exclusive. Taken together, these findings indicate that in the diploid nuclei of PtK{sub 1} cells, the three-dimensional organization of the nucleolar domain seems to be directly controlled by the X-chromosome.

Clinical Research Informatics: Challenges, Opportunities and Definition for an Emerging Domain

Science.gov (United States)

Embi, Peter J.; Payne, Philip R.O.

2009-01-01

Objectives Clinical Research Informatics, an emerging sub-domain of Biomedical Informatics, is currently not well defined. A formal description of CRI including major challenges and opportunities is needed to direct progress in the field. Design Given the early stage of CRI knowledge and activity, we engaged in a series of qualitative studies with key stakeholders and opinion leaders to determine the range of challenges and opportunities facing CRI. These phases employed complimentary methods to triangulate upon our findings. Measurements Study phases included: 1) a group interview with key stakeholders, 2) an email follow-up survey with a larger group of self-identified CRI professionals, and 3) validation of our results via electronic peer-debriefing and member-checking with a group of CRI-related opinion leaders. Data were collected, transcribed, and organized for formal, independent content analyses by experienced qualitative investigators, followed by an iterative process to identify emergent categorizations and thematic descriptions of the data. Results We identified a range of challenges and opportunities facing the CRI domain. These included 13 distinct themes spanning academic, practical, and organizational aspects of CRI. These findings also informed the development of a formal definition of CRI and supported further representations that illustrate areas of emphasis critical to advancing the domain. Conclusions CRI has emerged as a distinct discipline that faces multiple challenges and opportunities. The findings presented summarize those challenges and opportunities and provide a framework that should help inform next steps to advance this important new discipline. PMID:19261934

A chemical bath deposition route to facet-controlled Ag{sub 3}PO{sub 4} thin films with improved visible light photocatalytic activity

Energy Technology Data Exchange (ETDEWEB)

Gunjakar, Jayavant L.; Jo, Yun Kyung; Kim, In Young; Lee, Jang Mee; Patil, Sharad B. [Department of Chemistry and Nanoscience, College of Natural Sciences, Ewha Womans University, Seoul 03760 (Korea, Republic of); Pyun, Jae-Chul [Department of Materials Science and Engineering, College of Engineering, Yonsei University, Seoul (Korea, Republic of); Hwang, Seong-Ju, E-mail: hwangsju@ewha.ac.kr [Department of Chemistry and Nanoscience, College of Natural Sciences, Ewha Womans University, Seoul 03760 (Korea, Republic of)

2016-08-15

A facile, economic, and reproducible chemical bath deposition (CBD) method is developed for the fabrication of facet-controlled Ag{sub 3}PO{sub 4} thin films with enhanced visible light photocatalytic activity. The fine-control of bath temperature, precursor, complexing agent, substrate, and solution pH is fairly crucial in preparing the facet-selective thin film of Ag{sub 3}PO{sub 4} nanocrystal. The change of precursor from silver nitrate to silver acetate makes possible the tailoring of the crystal shape of Ag{sub 3}PO{sub 4} from cube to rhombic dodecahedron and also the bandgap tuning of the deposited films. The control of [Ag{sup +}]/[phosphate] ratio enables to maximize the loading amount of Ag{sub 3}PO{sub 4} crystals per the unit area of the deposited film. All the fabricated Ag{sub 3}PO{sub 4} thin films show high photocatalytic activity for visible light-induced degradation of organic molecules, which can be optimized by tailoring the crystal shape of the deposited crystals. This CBD method is also useful in preparing the facet-controlled hybrid film of Ag{sub 3}PO{sub 4}–ZnO photocatalyst. The present study clearly demonstrates the usefulness of the present CBD method for fabricating facet-controlled thin films of metal oxosalt and its nanohybrid. - Highlights: • The crystal facet of Ag{sub 3}PO{sub 4} films can be tuned by chemical bath deposition. • The crystal shape of Ag{sub 3}PO{sub 4} is tailorable from cube to rhombic dodecahedron. • Facet-tuned Ag{sub 3}PO{sub 4} film shows enhanced visible light photocatalyst activity.

Composition dependence of electric-field-induced structure of Bi{sub 1/2}(Na{sub 1−x}K{sub x}){sub 1/2}TiO{sub 3} lead-free piezoelectric ceramics

Energy Technology Data Exchange (ETDEWEB)

Khansur, Neamul H. [School of Materials Science and Engineering, UNSW Australia, 2052 Sydney (Australia); Department of Materials Science, University of Erlangen-Nürnberg, Erlangen 91058 (Germany); Benton, Rachel [Department of Chemical and Biomolecular Engineering, North Carolina State University, North Carolina 27695 (United States); Dinh, Thi Hinh; Lee, Jae-Shin [School of Materials Science and Engineering, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Jones, Jacob L. [Department of Materials Science and Engineering, North Carolina State University, North Carolina 27695 (United States); Daniels, John E. [School of Materials Science and Engineering, UNSW Australia, 2052 Sydney (Australia)

2016-06-21

Microscopic origins of the electric-field-induced strain for three compositions of Bi{sub 1/2}(Na{sub 1−x}K{sub x}){sub 1/2}TiO{sub 3} (x = 0.14, 0.18, and 0.22) (BNKT100x) ceramics have been compared using in situ high-energy (87.12 keV) X-ray diffraction. In the as-processed state, average crystallographic structure of BNKT14 and BNKT18 were found to be of rhombohedral symmetry, while BNKT22 was tetragonal. Diffraction data collected under electric field showed that both the BNKT14 and BNKT18 exhibit induced lattice strain and non-180° ferroelectric domain switching without any apparent phase transformation. The BNKT22 composition, in addition to the lattice strain and domain switching, showed an electric-field-induced transformation from a tetragonal to mixed tetragonal-rhombohedral state. Despite the difference in the origin of microscopic strain responses in these compositions, the measured macroscopic poling strains of 0.46% (BNKT14), 0.43% (BNKT18), and 0.44% (BNKT22) are similar. In addition, the application of a second poling field of opposite polarity to the first increased the magnitude of non-180° ferroelectric domain texture. This was suggested to be related to the existence of an asymmetric internal bias field.

Domain decomposition methods for the neutron diffusion problem

International Nuclear Information System (INIS)

Guerin, P.; Baudron, A. M.; Lautard, J. J.

2010-01-01

The neutronic simulation of a nuclear reactor core is performed using the neutron transport equation, and leads to an eigenvalue problem in the steady-state case. Among the deterministic resolution methods, simplified transport (SPN) or diffusion approximations are often used. The MINOS solver developed at CEA Saclay uses a mixed dual finite element method for the resolution of these problems. and has shown his efficiency. In order to take into account the heterogeneities of the geometry, a very fine mesh is generally required, and leads to expensive calculations for industrial applications. In order to take advantage of parallel computers, and to reduce the computing time and the local memory requirement, we propose here two domain decomposition methods based on the MINOS solver. The first approach is a component mode synthesis method on overlapping sub-domains: several Eigenmodes solutions of a local problem on each sub-domain are taken as basis functions used for the resolution of the global problem on the whole domain. The second approach is an iterative method based on a non-overlapping domain decomposition with Robin interface conditions. At each iteration, we solve the problem on each sub-domain with the interface conditions given by the solutions on the adjacent sub-domains estimated at the previous iteration. Numerical results on parallel computers are presented for the diffusion model on realistic 2D and 3D cores. (authors)

Valence band electronic structure of Nb{sub 2}Pd{sub 1.2}Se{sub 5} and Nb{sub 2}Pd{sub 0.95}S{sub 5} superconductors

Energy Technology Data Exchange (ETDEWEB)

Lohani, H. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400085 (India); Mishra, P. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Goyal, R.; Awana, V.P.S. [National Physical Laboratory(CSIR), Dr. K. S. Krishnan Road, New Delhi 110012 (India); Sekhar, B.R., E-mail: sekhar@iopb.res.in [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400085 (India)

2017-03-15

We present a comparative study of our valence band photoemission results on Nb{sub 2}Pd{sub 1.2}Se{sub 5} and Nb{sub 2}Pd{sub 0.95}S{sub 5} superconductors which are supported by our DFT based electronic structure calculations. We observe that the VB spectra of both the compounds are qualitatively similar, except for some slight differences in the binding energy positions of all the features. This could be due to the unequal electronegativities of Se and S atom. The calculated density of states (DOS) reveals that the VB features are mainly composed of Pd-Se/S hybridized states. The nature of DOS originating from the distinctly coordinated Pd atoms is different. Further, various Pd-4d and Nb-4d states crossing the Fermi level (E{sub f}) signifies the multiband character of these compounds. In addition, we find a temperature dependent pseudogap in Nb{sub 2}Pd{sub 0.95}S{sub 5} which is absent in Nb{sub 2}Pd{sub 1.2}Se{sub 5}.

Nano/micro Sr{sub 2}Bi{sub 4}Ti{sub 5}O{sub 18} crystallites: Size dependent structural, second harmonic and piezoelectric properties

Energy Technology Data Exchange (ETDEWEB)

Tukaram, Shet; Bhimireddi, Rajasekhar; Varma, K.B.R., E-mail: kbrvarma@mrc.iisc.ernet.in

2016-09-15

Graphical abstract: Synthesis of Sr{sub 2}Bi{sub 4}Ti{sub 5}O{sub 18} nano/micro crystallites and their size dependent non-linear optical and piezoelectric responses. - Highlights: • Nano/microcrystallites of Sr{sub 2}Bi{sub 4}Ti{sub 5}O{sub 18} were synthesized via sol-gel route. • Crystallite size dependent structural and physical properties were studied. • SHG intensity (1.4 times that of KDP powder) from these crystallites was recorded. • PFM studies on isolated crystallite of 480 nm exhibited d{sub 33} as high as 27 pm/V. • Single domain nature of the crystallites below 160 nm was observed. - Abstract: Strontium bismuth titanate (Sr{sub 2}Bi{sub 4}Ti{sub 5}O{sub 18}) powders comprising crystallites of average sizes in the range of 94–1400 nm were prepared via citrate-assisted sol-gel route. With an increase in the average crystallite size there was a change in the lattice parameters and shift in the Raman vibration modes. Second harmonic signal (532 nm) intensity of the Sr{sub 2}Bi{sub 4}Ti{sub 5}O{sub 18} powders increased with the increase in the average crystallite size and the maximum intensity obtained in the reflection mode was 1.4 times as high as that of the powdered KH{sub 2}PO{sub 4}. Piezo Force Microscopic analyses carried out on isolated crystallite of size 74 nm, established a single domain nature with the coercive field as high as 347 kV/cm. There was a systematic increase in the d{sub 33} value with an increase in the size of the isolated crystallites and a high piezoelectric coefficient of ∼27 pm/V was obtained from an isolated crystallite of size 480 nm.

Structural changes of Bi sub 1. 8 Sr sub 2 (Ca sub 1 minus x Y sub x )Cu sub 2. 2 O sub z ceramics with yttrium content studied by electron diffraction and high-resolution electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Onozuka, T.; Iwabuchi, Y.; Fukase, T. (Institute for Materials Research, Tohoku University, Sendai 980, Japan (JP)); Sato, H. (School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (USA)); Mitchell, T.E. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA))

1991-06-01

The mode of the incommensurate modulation in the {ital b} direction of the Bi{sub 1.8}Sr{sub 2}(Ca{sub 1{minus}{ital x}}Y{sub {ital x}})Cu{sub 2.2}O{sub {ital z}} (0.05{lt}{ital x}{lt}0.75) system is investigated by means of electron diffraction and high-resolution lattice imaging. The change of period of the long-period structure with {ital x} is found to be basically due to the mixing ratio of domains of two modulation periods with {ital b}=4.5{ital b}{sub 0} and 5{ital b}{sub 0} or 4.5{ital b}{sub 0} and 4{ital b}{sub 0}, thus creating periods of {ital b}=4.75{ital b}{sub 0--}4.0{ital b}{sub 0}. The fundamental orthorhombic lattice has dimensions of {ital a}{congruent}{ital b}{congruent}{ital b}{sub 0} (0.54 nm) and {ital c}{congruent}{ital c}{sub 0} (3.1 nm). The change of the mixing mode from one to the other mentioned above occurs just in the yttrium concentration range, 0.45{lt}{ital x}{lt}0.65, which also corresponds to the superconductor (metallic)-to-semiconductor transition boundary. The mixing modes of the domains are directly recorded as a contrast modulation with half periods, 4.5{ital b}{sub 0}/2 and 5{ital b}{sub 0}/2 or 4.5{ital b}{sub 0}/2 and 4{ital b}{sub 0}/2 in high-resolution lattice images. These images are reproduced well by a multislice computer-simulation technique.

Magnetic and transport properties of YBa{sub 2}Cu{sub 3}O{sub 7} - La{sub 0.7}Ca{sub 0.3}MnO{sub 3} heterostructures

Energy Technology Data Exchange (ETDEWEB)

Mustafa, Luqman

2016-11-25

prepare the ground for the atomistic studies by developing the technological prerequisites for the growth of (110)-oriented YBCO-LCMO heterostructures and characterize their structural, electric and magnetic macroscopic properties. Due to the sensitivity of the macroscopic properties of such structures to the crystallographic perfection of the interfaces a substantial part of this thesis is devoted to the corresponding enabling technology. Advanced PLD techniques are used to fabricate single layer (110)-oriented YBCO and LCMO films, bilayers as well as twin-free (103)-oriented LCMO-YBCO-LCMO trilayers and (110)-oriented YBCO-LCMO-YBCO structures with ultrathin LCMO films (nominally 1-2 nm) in between 50 nm YBCO. These (110)-oriented trilayers serve as a precursor for a prototype planar Josephson junction technology. A comparison of the experimental results for (001) and (110) - oriented heterostructures reveals distinct changes in the ordering temperatures T{sub c} and T{sub Curie} giving a fingerprint of different microscopic mechanisms taking place at the interfaces. Furthermore, in the twin-free (103)-oriented trilayer samples a novel positive Meissner effect has been observed which is ascribed to the magnetic domain arrangement of the LCMO.

Effect of temperature on structural, morphological and magnetic properties of Cd{sub 0.7}Co{sub 0.3}Fe{sub 2}O{sub 4} nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Prabhakar Vattikuti, S.V., E-mail: vsvprabu@gmail.com [School of Mechanical Engineering, Yeungnam University, Gyeongsan, Gyeongsangbuk-do 712-749, Republic of Korea, (Korea, Republic of); Byon, Chan [School of Mechanical Engineering, Yeungnam University, Gyeongsan, Gyeongsangbuk-do 712-749, Republic of Korea, (Korea, Republic of); Shim, Jaesool, E-mail: jshim@ynu.ac.kr [School of Mechanical Engineering, Yeungnam University, Gyeongsan, Gyeongsangbuk-do 712-749, Republic of Korea, (Korea, Republic of); Reddy, Ch. Venkata, E-mail: cvrphy@gmail.com [School of Mechanical Engineering, Yeungnam University, Gyeongsan, Gyeongsangbuk-do 712-749, Republic of Korea, (Korea, Republic of)

2015-11-01

Cadmium-substituted cobalt ferrite (Cd{sub 0.7}Co{sub 0.3}Fe{sub 2}O{sub 4}) nanoparticles were synthesized using a chemical synthesis method and synthesized particles were calcinated at 300 °C and 600 °C respectively. The samples were characterized in order to understand the temperature effect on structural, morphological, thermal, and magnetic properties. X-ray diffraction data confirm the formation of single-phase cubic structure and the average grain sizes were evaluated. The microstructural features were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and compositional analysis carried out by energy dispersive spectroscopy (EDS). A vibrating sample magnetometer (VSM) was used to investigate the magnetic properties. The hysteresis curves of Cd{sub 0.7}Co{sub 0.3}Fe{sub 2}O{sub 4} nanoparticles show enhancement of the coercivity with the increasing calcinated temperature. This enhancement is attributed to the transition from a multi-domain to a single-domain nature. The high and low frequency absorption bands of Cd{sub 0.7}Co{sub 0.3}Fe{sub 2}O{sub 4} were investigated using FT-IR analysis. - Highlights: • Cd{sub 0.7}Co{sub 0.3}Fe{sub 2}O{sub 4} nano particles are prepared by the chemical synthesis method. • X-ray diffraction data confirms the single phase cubic spinel structure. • The estimated particle sizes from the XRD are approximately 25 and 35 nm. • The coercivity and magnetization values increase with increasing the particle size. • FT-IR spectra indicate the fundamental vibrations of host lattices.

Controlled synthesis and photoluminescence properties of In{sub 2}O{sub 3} rods with dodecahedron In{sub 2}O{sub 3} microcrystals on top

Energy Technology Data Exchange (ETDEWEB)

Ouacha, Hassan [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh (Saudi Arabia); Hendaoui, Ali [Department of Physics, College of Science and General Studies, Alfaisal University, Riyadh (Saudi Arabia); Kleineberg, Ulf [Faculty of Physics, Ludwig Maximilian University of Munich, Garching (Germany); Albrithen, Hamad; Azzeer, Abdallah [Physics and Astronomy Department, King Saud University, Riyadh (Saudi Arabia)

2017-10-15

In{sub 2}O{sub 3} rods with dodecahedron In{sub 2}O{sub 3} microcrystals on top were synthesized in an electrical furnace via Au-catalyzed vapor transport process. A catalyst-assisted selective vapor-solid (VS) growth was proposed to explain the formation of the dodecahedron In{sub 2}O{sub 3} microcrystal, while the self-catalytic VS growth mechanism dominated the subsequent one-dimensional (1D) growth of the In{sub 2}O{sub 3} rod underneath the In{sub 2}O{sub 3} microcrystal. The structural evolution of these structures was carefully examined during the synthesis process by controlling the growth parameters. The morphologies, crystalline structures and surface chemistry were characterized by scanning electron microscopy (SEM), X-ray diffraction technique (XRD), and X-ray photoelectron spectroscopy (XPS), respectively. The photoluminescence (PL) spectrum at room temperature of the as-grown In{sub 2}O{sub 3} structures exhibited both UV and blue luminescence emission under one excitation at 260 nm, which may be related to the existence of oxygen vacancies. The synthesized multifaceted In{sub 2}O{sub 3} microcrystal has shown to contain a large number of vertices and may find many applications in developing three-dimensional (3D) resonators. This work will not only enrich the synthesis science but also will open doors for applications of such structures in optical devices. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Fabrication of heterostructured Bi{sub 2}O{sub 2}CO{sub 3}/Bi{sub 2}O{sub 4} photocatalyst and efficient photodegradation of organic contaminants under visible-light

Energy Technology Data Exchange (ETDEWEB)

Sun, Meng; Li, Shuangli; Yan, Tao; Ji, Pengge; Zhao, Xia; Yuan, Kun; Wei, Dong [School of Resources and Environment, University of Jinan, Jinan 250022 (China); Du, Bin, E-mail: dubin61@gmail.com [School of Resources and Environment, University of Jinan, Jinan 250022 (China); Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China)

2017-07-05

Highlights: • The product shows efficient activity in photodegradation of RhB, BPA, and phenol. • The BBOC-10 heterojunction exhibits the best activity under visible light. • Suppressed recombination of photo-generated carriers lead to the activity enhancement. - Abstract: Heterostructured Bi{sub 2}O{sub 2}CO{sub 3}/Bi{sub 2}O{sub 4} photocatalysts were fabricated by a facile one-pot hydrothermal method, in which melem served as the sacrificial reagent to supply carbonate anions. The as-synthesized Bi{sub 2}O{sub 2}CO{sub 3}/Bi{sub 2}O{sub 4} heterojunction catalysts were characterized by X-ray diffraction, UV–vis diffuse reflectance spectra, X-ray photoelectron spectroscopy, scanning electron microscope, and transmission electron microscope. The XRD patterns of Bi{sub 2}O{sub 2}CO{sub 3}/Bi{sub 2}O{sub 4} catalysts showed the distinctive peaks of Bi{sub 2}O{sub 2}CO{sub 3} and Bi{sub 2}O{sub 4}. The SEM and TEM results showed that the pure Bi{sub 2}O{sub 2}CO{sub 3} possessed large plate morphology, while Bi{sub 2}O{sub 4} were composed of various nanorods and particles. As for Bi{sub 2}O{sub 2}CO{sub 3}/Bi{sub 2}O{sub 4} heterojunction, it was obviously observed that Bi{sub 2}O{sub 4} nanorods and particles were grown on the surfaces of Bi{sub 2}O{sub 2}CO{sub 3} plates. The visible light driven photocatalytic activity of Bi{sub 2}O{sub 2}CO{sub 3}/Bi{sub 2}O{sub 4} heterojunction photocatalyst was evaluated by decomposing dyes, phenol, and bisphenol A in water. Compared with Bi{sub 2}O{sub 2}CO{sub 3} and Bi{sub 2}O{sub 4}, the Bi{sub 2}O{sub 2}CO{sub 3}/Bi{sub 2}O{sub 4} photocatalysts have exhibited remarkable enhanced activity under visible light. The excellent activity can be mainly attributed to the enhanced separation efficiency of photo-generated carriers. Controlled experiments using different radical scavengers proved that ·O{sub 2}{sup −} and h{sup +} played the main role in decomposing organic pollutants. The results of this work would

Changes in modulation period of Bi sub 2 Sr sub 2 (Ca sub 1-x Nd sub x )Cu sub 2 O sub 8+. delta. and their relations to oxygen content

Energy Technology Data Exchange (ETDEWEB)

Onozuka, Takashi; Tokiwa, Ayako; Syono, Yasuhiko (Inst. for Materials Research, Tohoku Univ., Sendai (Japan)); Koike, Yoji; Saito, Yoshitami (Dept. of Applied Physics, Tohoku Univ., Sendai (Japan))

1991-12-01

Structural changes of long-period modulated structure (LPMS) of the Bi{sub 2}Sr{sub 2}(Ca{sub 1-x}Nd{sub x})Cu{sub 2}O{sub 8+{delta}} ceramics with x are investigated by means of electron diffraction. Increasing x, the modulation mode of the mixing of domains of two modulation periods with b=4.5b{sub o} and b=5b{sub o} changes to that with b=4.5b{sub o} and b=4b{sub o} through the modulation mode with only b=4.5b{sub o} at x=0.4-0.5. The wavenumber of the superlattice reflection shows a stepwise increase rather than a linear increase with x. Excess oxygen in a LPMS model with the site of excess oxygen is shown to be consistent with excess oxygen analyzed chemically by iodometry and its change with x. (orig.).

Frequency Domain Electroretinography in Retinitis Pigmentosa versus Normal Eyes

Directory of Open Access Journals (Sweden)

Homa Hassan-Karimi

2012-01-01

Full Text Available Purpose: To compare electroretinogram (ERG characteristics in patients with retinitis pigmentosa (RP and normal subjects using frequency domain analysis. Methods: Five basic ERG recordings were performed in normal subjects and patients with a clinical diagnosis of RP according to the ISCEV (International Society of Clinical Electrophysiology of Vision protocol. Frequency domain analysis was performed by MATLAB software. Different frequency domain parameters were compared between the study groups. Results: Peak frequency (Fmod of flicker and oscillatory responses in RP patients showed significant (P<0.0001 high pass response as compared to normal controls. Peak frequency (Fmod of the other responses was not significantly different between the two groups. Conclusion: In addition to conventional ERG using time domain methods, frequency domain analysis may be useful for diagnosis of RP. Oscillatory and flicker responses may be analyzed in frequency domain. Fast Fourier transform may reveal two distinct high pass responses (shift to higher frequencies in Fmod. Time and frequency domain analyses may be performed simultaneously with many modern ERG machines and may therefore be recommended in RP patients.

Structural and functional analysis of multi-interface domains.

Directory of Open Access Journals (Sweden)

Liang Zhao

Full Text Available A multi-interface domain is a domain that can shape multiple and distinctive binding sites to contact with many other domains, forming a hub in domain-domain interaction networks. The functions played by the multiple interfaces are usually different, but there is no strict bijection between the functions and interfaces as some subsets of the interfaces play the same function. This work applies graph theory and algorithms to discover fingerprints for the multiple interfaces of a domain and to establish associations between the interfaces and functions, based on a huge set of multi-interface proteins from PDB. We found that about 40% of proteins have the multi-interface property, however the involved multi-interface domains account for only a tiny fraction (1.8% of the total number of domains. The interfaces of these domains are distinguishable in terms of their fingerprints, indicating the functional specificity of the multiple interfaces in a domain. Furthermore, we observed that both cooperative and distinctive structural patterns, which will be useful for protein engineering, exist in the multiple interfaces of a domain.

Eu{sup 3+}-doped Y{sub 2}O{sub 3} hexagonal prisms: Shape-controlled synthesis and tailored luminescence properties

Energy Technology Data Exchange (ETDEWEB)

Yang, Errui [Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Li, Guangshe [Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Fu, Chaochao; Zheng, Jing [Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Huang, Xinsong [Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Xu, Wen [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Li, Liping, E-mail: lipingli@fjirsm.ac.cn [Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2015-10-25

In this work, Eu{sup 3+} doped Y{sub 2}O{sub 3} hexagonal prisms were synthesized by a novel two-phase approach, which involves water at the bottom as aqueous phase and oleylamine in the above as oil phase. With this unique reaction system, precursors of hexagonal prisms Y{sub 4}O(OH){sub 9}(NO{sub 3}) were first obtained by simply varying the volume ratio of water to oleylamine. Time-dependent experiments were systematically performed to reveal the growth mechanism of the precursor. After subsequent heat treatment, these precursors transformed to Y{sub 2}O{sub 3} hexagonal prisms with controlled diameters and aspect ratios varying from 4 to 19. Such a transformation is preceded via a topotactic process, as indicated by TG-DTA and mass spectra. Eventually, all Eu{sup 3+} doped Y{sub 2}O{sub 3} hexagonal prisms were found to exhibit an intensive red emission at 611 nm, which corresponds to {sup 5}D{sub 0}→{sup 7}F{sub 2} transition of Eu{sup 3+}. With varying the aspect ratio of hexagonal prisms and increasing Eu{sup 3+} concentration in Y{sub 2}O{sub 3}, an optimum external quantum efficiency was achieved. - Graphical abstract: In this work, Eu{sup 3+} doped Y{sub 2}O{sub 3} hexagonal prisms with controlled aspect ratio from 4.4 to 19.3 were synthesized by transformation of the precursor Y{sub 4}O(OH){sub 9}(NO{sub 3}) hexagonal prisms from a novel two-phase reaction system. The growth mechanism of the precursor has been systematically investigated, and a topotactic phase transformation from precursors to cubic Y{sub 2}O{sub 3} is for the first time put forward. By the size controlling and aspect ratio adjusting, the luminescence emission intensity as well as external quantum efficiency of Eu{sup 3+} doped Y{sub 2}O{sub 3} hexagonal prisms is further tailored to show an optimum. - Highlights: • Eu{sup 3+} doped Y{sub 2}O{sub 3} hexagonal prisms were synthesized by a novel two-phase approach. • Inheriting mechanism of prisms morphology from Y{sub 4}O(OH){sub 9

The effects of multi-domain versus single-domain cognitive training in non-demented older people: a randomized controlled trial

Directory of Open Access Journals (Sweden)

Cheng Yan

2012-03-01

Full Text Available Abstract Background Whether healthy older people can benefit from cognitive training (CogTr remains controversial. This study explored the benefits of CogTr in community dwelling, healthy, older adults and compared the effects of single-domain with multi-domain CogTr interventions. Methods A randomized, controlled, 3-month trial of CogTr with double-blind assessments at baseline and immediate, 6-month and 12-month follow-up after training completion was conducted. A total of 270 healthy Chinese older people, 65 to 75 years old, were recruited from the Ganquan-area community in Shanghai. Participants were randomly assigned to three groups: multi-domain CogTr, single-domain CogTr, and a wait-list control group. Twenty-four sessions of CogTr were administrated to the intervention groups over a three-month period. Six months later, three booster training sessions were offered to 60% of the initial training participants. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS, Form A, the Color Word Stroop test (CWST, the Visual Reasoning test and the Trail Making test (TMT were used to assess cognitive function. Results Multi-domain CogTr produced statistically significant training effects on RBANS, visual reasoning, and immediate and delayed memory, while single-domain CogTr showed training effects on RBANS, visual reasoning, word interference, and visuospatial/constructional score (all P Conclusions Cognitive training can improve memory, visual reasoning, visuospatial construction, attention and neuropsychological status in community-living older people and can help maintain their functioning over time. Multi-domain CogTr enhanced memory proficiency, while single-domain CogTr augmented visuospatial/constructional and attention abilities. Multi-domain CogTr had more advantages in training effect maintenance. Clinical Trial Registration Chinese Clinical Trial Registry. Registration number: ChiCTR-TRC-09000732.

Monodisperse Ni{sub x}Fe{sub 3-x}O{sub 4} nanospheres: Metal-ion-steered size/composition control mechanism, static magnetic and enhanced microwave absorbing properties

Energy Technology Data Exchange (ETDEWEB)

Jiang, Kedan, E-mail: 17858961652@163.com [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China); Liu, Yun, E-mail: liuyun650403@163.com [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Pan, Yefei, E-mail: 3083780256@qq.com [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China); Wang, Ru, E-mail: 631081137@qq.com [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China); Hu, Panbing, E-mail: 1036855954@qq.com [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China); He, Rujia, E-mail: 634185782@qq.com [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China); Zhang, Lingli, E-mail: 786510121@qq.com [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China); Tong, Guoxiu, E-mail: tonggx@zjnu.cn [College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004 (China)

2017-05-15

Highlights: • A metal-ion-steered solvothermal method for synthesizing Ni{sub x}Fe{sub 3-x}O{sub 4} nanospheres. • Proposing an in situ-reduction, coordination-precipitation transformation mechanism. • Investigating size- and composition-dependent static magnetic properties. • Investigating size- and composition-dependent microwave absorbing properties. - Abstract: An easy metal-ion-steered solvothermal method was developed for the one-step synthesis of monodisperse, uniform Ni{sub x}Fe{sub 3-x}O{sub 4} polycrystalline nanospheres with tunable sphere diameter (40–400 nm) and composition (0 ≤ x ≤ 0.245) via changing just Ni{sup 2+}/Fe{sup 3+} molar ratio (γ). With g increased from 0:1 to 2:1, sphere diameter gradually decreased and crystal size exhibited an inversed U-shaped change tendency, followed by increased Ni/Fe atom ratio from 0% to 0.0888%. An in situ-reduction, coordination-precipitation transformation mechanism was proposed to interpret the metal-ion-steered growth. Size- and composition-dependent static magnetic and microwave absorbing properties were systematically investigated. Saturation magnetization declines with g in a Boltzmann model due to the changes of crystal size, sphere diameter, and Ni content. The coercivity reaches a maximum at γ = 0.75:1 because of the critical size of Fe{sub 3}O{sub 4} single domain (25 nm). Studies on microwave absorption reveal that 150–400 nm Fe{sub 3}O{sub 4} nanospheres mainly obey the quarter-wavelength cancellation model with the single-band absorption; 40–135 nm Ni{sub x}Fe{sub 3-x}O{sub 4} nanospheres (0 ≤ x ≤ 0.245) obey the one and three quarter-wavelength cancellation model with the multi-band absorption. 150 nm Fe{sub 3}O{sub 4} nanospheres exhibit the optimal EM wave-absorbing property with an absorbing band of 8.94 GHz and the maximum R{sub L} of −50.11 dB.

Crystallization of Zr<sub>2sub>Pd_xCu>1-xsub> and Zr<sub>2sub>Ni_xCu>1-xsub> Metallic Glass

Energy Technology Data Exchange (ETDEWEB)

Xu, Min [Iowa State Univ., Ames, IA (United States)

2008-01-01

C11b phase at x = 0.5, which is dominated by electronic structure rather than size effects. Cu-rich and Ni-rich compositions in Zr<sub>2sub>Ni_xCu>1-xsub> trend to divitrify to C11b or C16 phases respectively. In the proposed pseudo binary phase diagram, the domain of C16, C11b and co-existence phases are mainly related with the topology in the amorphous structure and formation enthalpies of crystalline phases.

Synthesis and photoluminescence control of Ca{sub 10.5–1.5x}La{sub x}(PO{sub 4}){sub 7}:Eu{sup 2+} phosphors by aliovalent cation substitution

Energy Technology Data Exchange (ETDEWEB)

Fan, Yanting; Tang, Miao; Qiu, Zhongxian; Zhang, Jilin; Yu, Liping; Li, Chengzhi; Lian, Shixun; Zhou, Wenli, E-mail: chemwlzhou@hunnu.edu.cn

2017-02-15

A range of Ca{sub 10.5-1.5x}La{sub x}(PO{sub 4}){sub 7}:Eu{sup 2+}phosphors were synthesized by high temperature solid state method. Subsequently we studied the crystal structures and luminescent properties through X-ray diffraction, photoluminescence and photoluminescence excitation, diffuse reflection spectra, Raman spectra and decay curves systematically. Based on the special crystal structure ofβ-Ca{sub 3}(PO{sub 4}){sub 2}:Eu{sup 2+}, its emission undergoes a variation from violet–blue to cyan through introducing La{sup 3+}. The substitution of La{sup 3+} for Ca{sup 2+} could form some cation vacancies in Ca(4) sites according to the scheme 3Ca{sup 2+}= 2La{sup 3+}+ □ due to the different ion valence, which compels Eu{sup 2+} to migrate from Ca(4) site to other sites. Additionally, the formation of the cation vacancies can further reduce the thermal stability of phosphors. - Highlights: • Realizing photoluminescence control of Eu{sup 2+} by introducing relatively larger La{sup 3+} ion to replace the Ca{sup 2+} in β-Ca{sub 3}(PO{sub 4}){sub 2}:Eu{sup 2+} phosphor. • The mechanism of spectral control is proposed to be due to emptying of Ca{sup 2+} and migration of Eu{sup 2+}. • The thermal stability reduction is related to the formation of vacancies.

Electrodeposition of textured Bi{sub 27}Sb{sub 28}Te{sub 45} nanowires with enhanced electrical conductivity

Energy Technology Data Exchange (ETDEWEB)

Hasan, Maksudul, E-mail: maksudul.hasan@tyndall.ie [Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland); Gautam, Devendraprakash [Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland); Enright, Ryan [Thermal Management Research Group, Efficient Energy Transfer Department, Bell Labs Ireland, Alcatel-Lucent Ireland Ltd., Dublin (Ireland)

2016-04-15

This work presents the template based pulsed potential electrodeposition technique of highly textured single crystalline bismuth antimony telluride (Bi{sub 1-x}Sb{sub x}){sub 2}Te{sub 3} nanowires from a single aqueous electrolyte. Cyclic voltammetry was used as an electroanalytical tool to assess the effect of the precursor concentrations on the composition of the deposits and to determine the deposition potential for each element. Pulsed potential electrodeposition was then applied on a gold-coated anodised alumina template to examine the effect of the pulse parameters on the composition and texture of Bi{sub 27}Sb{sub 28}Te{sub 45} nanowires. The nanowires are cylindrical in shape formed during the deposition inside the porous template and highly textured as they are decorated with sparse distribution of small crystal domains. The electrical conductivity (24.1 × 10{sup 4} S m{sup −1}) of a single nanowire was measured using a four-point probe technique implemented on a custom fabricated test chip. In this work, we demonstrated that crystal orientation with respect to the transport direction controlled by tuning the pulsed electrodeposition parameters. This allowed us to realise electrical conductivities ∼2.5 times larger than Sb doped bismuth-tellurium based ternary material systems and similar to what is typically seen in binary systems. - Highlights: • Pulsed electrodeposition is described towards fabrication of (Bi{sub 1-x}Sb{sub x}){sub 2}Te{sub 3} nanowires. • The adopted method is compatible with existing CMOS process. • The nanowires were fabricated as highly textured to enhance phonon scattering. • The electrical conductivity is ∼2.5 times larger than the current ternary materials.

Cross-sectional analysis of ferroelectric domains in PZT capacitors via piezoresponse force microscopy

Energy Technology Data Exchange (ETDEWEB)

Liu, J S [School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang City (China); Zeng, H Z [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Kholkin, A L [Department of Ceramic and Glass Engineering and CICECO, University of Aveiro, Aveiro 3810-193 (Portugal)

2007-11-21

Ferroelectric domains have been investigated on the cross-section of Pb(Zr{sub 0.55}Ti{sub 0.45})O{sub 3} (PZT) thin film capacitors by scanning probe microscopy. The static domain images on the cross-section were obtained by the lateral piezoresponse force microscopy (LPFM) method, in which the ac voltage used to induce the converse piezoelectric effect was applied between the conductive tip and the bottom electrode. The polarization component normal to the substrate could be characterized via both d{sub 33} and d{sub 15} piezoelectric coefficients, which resulted in a high resolution of LPFM images. After a variable dc bias was applied between the top and the bottom electrodes, the variations of domain image on the cross-section were recorded by the LPFM immediately. Upon the application of low bias, new domain sites appeared near the PZT/Pt interface opposite to the initial polarization. Forward stretch of new domains was facilitated under the dc field approaching the coercive field E{sub c}. Under a very high field (about three times of the E{sub c}), the sidewise expansion of columnar domains was observed. However, the domains were only partially switched even though a very high field was applied. The observed domain growth process indicated a lower energy barrier for nucleation compared with that of domain wall motion. Possible reasons for the incomplete switching are the substantial influences of the interface and depolarization in thin film capacitors.

Principles of Eliminating Access Control Lists within a Domain

Directory of Open Access Journals (Sweden)

Vic Grout

2012-04-01

Full Text Available The infrastructure of large networks is broken down into areas that have a common security policy called a domain. Security within a domain is commonly implemented at all nodes. However this can have a negative effect on performance since it introduces a delay associated with packet filtering. When Access Control Lists (ACLs are used within a router for this purpose then a significant overhead is introduced associated with this process. It is likely that identical checks are made at multiple points within a domain prior to a packet reaching its destination. Therefore by eliminating ACLs within a domain by modifying the ingress/egress points with equivalent functionality an improvement in the overall performance can be obtained. This paper considers the effect of the delays when using router operating systems offering different levels of functionality. It considers factors which contribute to the delay particularly due to ACLs and by using theoretical principles modified by practical calculation a model is created. Additionally this paper provides an example of an optimized solution which reduces the delay through network routers by distributing the security rules to the ingress/egress points of the domain without affecting the security policy.

Magnetic properties and coercivity mechanism of Sm{sub 1-x}Pr{sub x}Co{sub 5} (x=0-0.6) nanoflakes prepared by surfactant-assisted ball milling

Energy Technology Data Exchange (ETDEWEB)

Xu, M. L.; Yue, M., E-mail: yueming@bjut.edu.cn; Wu, Q.; Li, Y. Q.; Lu, Q. M. [College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China)

2016-05-15

Sm{sub 1-x}Pr{sub x}Co{sub 5} (x=0-0.6) nanoflakes with CaCu{sub 5} structure were successfully prepared by surfactant-assisted high-energy ball milling (SAHEBM). The crystal structure and magnetic properties of Sm{sub 1-x}Pr{sub x}Co{sub 5} (x=0-0.6) nanoflakes were studied by X-ray diffraction and vibrating sample magnetometer. Effects of Pr addition on the structure, magnetic properties and coercivity mechanism of Sm{sub 1-x}Pr{sub x}Co{sub 5} nanoflakes were systematically investigated. XRD results show that all the nanoflakes have a hexagonal CaCu{sub 5}-type (Sm, Pr){sub 1}Co{sub 5} main phase and the (Sm, Pr){sub 2}Co{sub 7} impurity phase, and all of the samples exhibit a strong (00l) texture after magnetic alignment. As the Pr content increases, remanence firstly increases, then slightly reduced, while anisotropy field (H{sub A}) and H{sub ci} of decrease monotonically. Maximum energy product [(BH){sub max}] of the flakes increases first, peaks at 24.4 MGOe with Pr content of x = 0.4, then drops again. Magnetization behavior analysis indicate that the coercivity mechanism is mainly controlled by inhomogeneous domain wall pinning, and the pinning strength weakens with the increased Pr content, suggesting the great influence of H{sub A} on the coercivity of flakes.

Sub-criticality monitoring for ADTR trademark control

International Nuclear Information System (INIS)

Ashworth, Roger

2014-01-01

Following the debut of the Accelerator Driven Thorium Reactor (ADTR trademark) Power Station at ENC 2010 in Barcelona, thorium as a reactor fuel has gained increasing support. The ADTR trademark concept reactor introduced the combination of an accelerator driven system (ADS) with traditional control rod technology, to provide a very high gain novel sub-critical ADS reactor design. The high gain of the system, while significantly reducing the demands on the accelerator design, pushes up operational sub-criticality (k eff ) closer to unity. In this paper we review this design and the progress made since ENC 2010. We compare 2 different methods of measuring the sub-critical neutron multiplication factor as the fuel cycle develops. The paper discusses the most recent work on k eff measurement and the interesting relationship between neutron flux, accelerator current and fuel temperature when using beam pulse methods to determine operational sub-criticality, of which a European patent is being granted. (orig.)

BiOCl{sub x}Br{sub y}I{sub z} (x + y + z = 1) solid solutions with controllable band gap and highly enhanced visible light photocatalytic performances

Energy Technology Data Exchange (ETDEWEB)

Sun, Xiuguo; Zhang, Yangyang; Li, Chunmei; Zhang, Zhifeng; Peng, Zheng; Si, Huayan; Zhang, Jianmin [School of Materials Science and Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043 (China); Li, Yanting, E-mail: yantingcn@stdu.edu.cn [School of Materials Science and Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043 (China); Hebei Provincial Key Laboratory of Traffic Engineering materials, Shijiazhuang Tiedao University, Shijiazhuang 050043 (China)

2015-07-25

Highlights: • BiOCl{sub x}Br{sub y}I{sub z} solid solutions were prepared by hydrolysis method. • Band gap of the solid solutions can be controllable by adjusting the molar ratio of halogen ions. • The samples show higher visible light photocatalytic activity than pure BiOX. • Orbital diversification of VB is beneficial to separating the holes and electrons effectively. • The mechanisms are discussed by active species trapping and band theory. - Abstract: A series of BiOCl{sub x}Br{sub y}I{sub z} solid solutions with controllable band gap and highly enhanced visible light photocatalytic performances were synthesized by a simple hydrolysis method. The samples were characterized by X-ray powder diffraction, UV–vis diffuse reflectance spectra, scanning electron microscope, high-resolution transmission electron microscopy and Brunauer–Emmett–Teller analysis. By adjusting the molar ratio of halogen ions, the band gap of BiOCl{sub x}Br{sub y}I{sub z} could be controllable to the suitable value for a photocatalytic reaction. Especially, BiOCl{sub x}Br{sub y}I{sub z} with a 1:1:2 molar ratio of Cl, Br to I showed the highest visible light photocatalytic activity for the degradation of methyl orange than individual BiOX systems. The degradation efficiency could reach over 90% within 60 min. The possible mechanism of photogenerated carrier transfer and higher photocatalytic activity was analyzed by active species trapping and energy band theory.

Use of the Charge/Discharge (C/D) ratio to aument voltage limit (V sub T) charge control in the ERBS spacecraft

Science.gov (United States)

Halpert, G.

1982-01-01

A 50-ampere hour nickel cadmium cell test pack was operated in a power profile simulating the orbit of the Earth Radiation Budget Satellite (ERBS). The objective was to determine the ability of the temperature compensated voltage limit (V sub T) charge control system to maintain energy balance in the half sine wave-type current profile expected of this mission. The four-cell pack (50 E) was tested at the Naval Weapons Support Center (NWSC) at Crane, Indiana. The ERBS evaluation test consisted of two distinct operating sequences, each having a specific purpose. The first phase was a parametric test involving the effect of V sub T level, temperature, and Beta angle on the charge/discharge (C/D) ratio, an indicator of the amount of overcharge. The second phase of testing made use of the C/D ratio limit to augment the V sub T charge limit control. When the C/D limit was reached, the current was switched from the taper mode to a C/67 (0.75 A) trickle charge. The use of an ampere hour integrator limiting the overcharge to a C/67 rate provided a fine tuning of the charge control technique which eliminated the sensitivity problems noted in the initial operating sequence.

L(sub 1) Adaptive Control Design for NASA AirSTAR Flight Test Vehicle

Science.gov (United States)

Gregory, Irene M.; Cao, Chengyu; Hovakimyan, Naira; Zou, Xiaotian

2009-01-01

In this paper we present a new L(sub 1) adaptive control architecture that directly compensates for matched as well as unmatched system uncertainty. To evaluate the L(sub 1) adaptive controller, we take advantage of the flexible research environment with rapid prototyping and testing of control laws in the Airborne Subscale Transport Aircraft Research system at the NASA Langley Research Center. We apply the L(sub 1) adaptive control laws to the subscale turbine powered Generic Transport Model. The presented results are from a full nonlinear simulation of the Generic Transport Model and some preliminary pilot evaluations of the L(sub 1) adaptive control law.

TEA controllable preparation of magnetite nanoparticles (Fe{sub 3}O{sub 4} NPs) with excellent magnetic properties

Energy Technology Data Exchange (ETDEWEB)

Han, Chengliang, E-mail: clhan@issp.ac.cn [Department of Chemical and Material Engineering, Hefei University, Hefei 230601 (China); Zhu, Dejie [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Wu, Hanzhao; Li, Yao; Cheng, Lu; Hu, Kunhong [Department of Chemical and Material Engineering, Hefei University, Hefei 230601 (China)

2016-06-15

A fast and controllable synthesis method for superparamagnetic magnetite nanoparticles (Fe{sub 3}O{sub 4} NPs) was developed in Fe(III)-triethanolamine (TEA) solution. The phase structure, morphology and particle size of the as-synthesized samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the magnetic particles were pure Fe{sub 3}O{sub 4} with mean sizes of approximately 10 nm. The used TEA has key effects on the formation of well dispersing Fe{sub 3}O{sub 4} NPs. Vibrating sample magnetometer (VSM) result indicated that the as-obtained Fe{sub 3}O{sub 4} NPs exhibited superparamagnetic behavior and the saturation magnetization (M{sub s}) was about 70 emu/g, which had potential applications in magnetic science and technology. - Highlights: • The Fe{sub 3}O{sub 4} NPs are synthesized by a simple and low-cost hydrothermal approach. • The triethanolamine (TEA) played vital roles in the formation of Fe{sub 3}O{sub 4} NPs. • Our samples exhibited superparamagnetic and excellent dispersing properties in water.

An Optimal Reactive Power Control Strategy for a DFIG-Based Wind Farm to Damp the Sub-Synchronous Oscillation of a Power System

Directory of Open Access Journals (Sweden)

Bin Zhao

2014-05-01

Full Text Available This study presents the auxiliary damping control with the reactive power loop on the rotor-side converter of doubly-fed induction generator (DFIG-based wind farms to depress the sub-synchronous resonance oscillations in nearby turbogenerators. These generators are connected to a series capacitive compensation transmission system. First, the damping effect of the reactive power control of the DFIG-based wind farms was theoretically analyzed, and a transfer function between turbogenerator speed and the output reactive power of the wind farms was introduced to derive the analytical expression of the damping coefficient. The phase range to obtain positive damping was determined. Second, the PID phase compensation parameters of the auxiliary damping controller were optimized by a genetic algorithm to obtain the optimum damping in the entire subsynchronous frequency band. Finally, the validity and effectiveness of the proposed auxiliary damping control were demonstrated on a modified version of the IEEE first benchmark model by time domain simulation analysis with the use of DigSILENT/PowerFactory. Theoretical analysis and simulation results show that this derived damping factor expression and the condition of the positive damping can effectively analyze their impact on the system sub-synchronous oscillations, the proposed wind farms reactive power additional damping control strategy can provide the optimal damping effect over the whole sub-synchronous frequency band, and the control effect is better than the active power additional damping control strategy based on the power system stabilizator.

The high-affinity peptidoglycan binding domain of Pseudomonas phage endolysin KZ144

Energy Technology Data Exchange (ETDEWEB)

Briers, Yves [Division of Gene Technology, Department of Biosystems, Katholieke Universiteit Leuven, Kasteelpark Arenberg 21, B-3001 Leuven (Belgium); Schmelcher, Mathias; Loessner, Martin J. [Institute of Food Science and Nutrition, ETH Zuerich, Schmelzbergstrasse 7, CH-8092 Zuerich (Switzerland); Hendrix, Jelle; Engelborghs, Yves [Laboratory of Biomolecular Dynamics, Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200G, B-3001 Leuven (Belgium); Volckaert, Guido [Division of Gene Technology, Department of Biosystems, Katholieke Universiteit Leuven, Kasteelpark Arenberg 21, B-3001 Leuven (Belgium); Lavigne, Rob, E-mail: rob.lavigne@biw.kuleuven.be [Division of Gene Technology, Department of Biosystems, Katholieke Universiteit Leuven, Kasteelpark Arenberg 21, B-3001 Leuven (Belgium)

2009-05-29

The binding affinity of the N-terminal peptidoglycan binding domain of endolysin KZ144 (PBD{sub KZ}), originating from Pseudomonas aeruginosa bacteriophage {phi}KZ, has been examined using a fusion protein of PBD{sub KZ} and green fluorescent protein (PBD{sub KZ}-GFP). A fluorescence recovery after photobleaching analysis of bound PBD{sub KZ}-GFP molecules showed less than 10% fluorescence recovery in the bleached area within 15 min. Surface plasmon resonance analysis confirmed this apparent high binding affinity revealing an equilibrium affinity constant of 2.95 x 10{sup 7} M{sup -1} for the PBD{sub KZ}-peptidoglycan interaction. This unique domain, which binds to the peptidoglycan of all tested Gram-negative species, was harnessed to improve the specific activity of the peptidoglycan hydrolase domain KMV36C. The chimeric peptidoglycan hydrolase (PBD{sub KZ}-KMV36C) exhibits a threefold higher specific activity than the native catalytic domain (KMV36C). These results demonstrate that the modular assembly of functional domains is a rational approach to improve the specific activity of endolysins from phages infecting Gram-negatives.

Application of modern tensor calculus to engineered domain structures. 2. Tensor distinction of domain states

Czech Academy of Sciences Publication Activity Database

Kopský, Vojtěch

2006-01-01

Roč. 62, - (2006), s. 65-76 ISSN 0108-7673 R&D Projects: GA ČR GA202/04/0992 Institutional research plan: CEZ:AV0Z10100520 Keywords : tensorial covariants * domain states * stability spaces Subject RIV: BE - Theoretical Physics Impact factor: 1.676, year: 2006

Oxidation potential (E/sub h/) and pH control during experimentation

International Nuclear Information System (INIS)

Seitz, M.G.

1982-01-01

Purpose of this statement is to introduce the subject of oxidation potential, E/sub h/, and to discuss its control in experiments. After the concept of E/sub h/ is reviewed, the range of oxidation potentials expected to be associated with a repository for high level nuclear waste will be addressed. Finally, three laboratory methods of controlling E/sub h/ will be described, along with some perspective that has been derived from experience given for each method

n-VO{sub 2}/p-GaN based nitride–oxide heterostructure with various thickness of VO{sub 2} layer grown by MBE

Energy Technology Data Exchange (ETDEWEB)

Wang, Minhuan [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Bian, Jiming, E-mail: jmbian@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences, Shanghai 200050, China (China); Sun, Hongjun; Liu, Weifeng [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Zhang, Yuzhi [Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences, Shanghai 200050, China (China); Luo, Yingmin [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2016-12-15

Graphical abstract: The significant influences of VO{sub 2} layer thickness on the structural, electrical and contact properties of the n-VO{sub 2}/p-GaN based nitride-oxide heterostructure were investigated systemically. - Highlights: • High quality VO{sub 2} films with precisely controlled thickness were grown on p-GaN/sapphire substrates by oxide molecular beam epitaxy (O-MBE). • A distinct reversible SMT phase transition was observed for the n-VO{sub 2}/p-GaN based nitride-oxide heterostructure. • The clear rectifying transport characteristics originated from the n-VO{sub 2}/p-GaN interface were demonstrated before and after SMT of the VO{sub 2} over layer. • The XPS analyses confirmed the valence state of V in VO{sub 2} films was principally composed of V{sup 4+} with trace amount of V{sup 5+}. • The design and modulation of the n-VO{sub 2}/p-GaN based heterostructure devices will benefit significantly from these achievements. - Abstract: High quality VO{sub 2} films with precisely controlled thickness were grown on p-GaN/sapphire substrates by oxide molecular beam epitaxy (O-MBE). Results indicated that a distinct reversible semiconductor-to-metal (SMT) phase transition was observed for all the samples in the temperature dependent electrical resistance measurement, and the influence of VO{sub 2} layer thickness on the SMT properties of the as-grown n-VO{sub 2}/p-GaN based nitride-oxide heterostructure was investigated. Meanwhile, the clear rectifying transport characteristics originated from the n-VO{sub 2}/p-GaN interface were demonstrated before and after SMT of the VO{sub 2} over layer, which were attributed to the p-n junction behavior and Schottky contact character, respectively. Moreover, the X-ray photoelectron spectroscopy (XPS) analyses confirmed the valence state of vanadium (V) in VO{sub 2} films was principally composed of V{sup 4+} with trace amount of V{sup 5+}. The design and modulation of the n-VO{sub 2}/p-GaN based heterostructure

Electronic structure determination of R{sub 3}T{sub 4}Sn{sub 13}

Energy Technology Data Exchange (ETDEWEB)

Chen, Xiaoye; Tan, HongEn; Klintberg, Lina E.; Tompsett, David A.; Grosche, F. Malte; Sutherland, Michael [University of Cambridge, Cavendish Laboratory, Cambridge (United Kingdom); Goh, Swee K. [University of Cambridge, Cavendish Laboratory, Cambridge (United Kingdom); The Chinese University of Hong Kong, Department of Physics, Hong Kong (China); Friedemann, Sven [University of Cambridge, Cavendish Laboratory, Cambridge (United Kingdom); University of Bristol, HH Wills Physics Laboratory, Bristol (United Kingdom); Yang, Jinhu; Chen, Bin [Hangzhou Normal University, Department of Physics, Hangzhou (China); Kyoto University, Department of Chemistry, Kyoto (Japan); Yoshimura, Kazuyoshi [Kyoto University, Department of Chemistry, Kyoto (Japan); Yu, Wing Chi [The Chinese University of Hong Kong, Department of Physics, Hong Kong (China)

2016-07-01

The quasi-skutterudite superconducting material family R{sub 3}T{sub 4}Sn{sub 13} (R = Ca, Sr, T = Ir, Rh) was recently shown to have a composition and pressure induced structural quantum phase transition. The end member material Sr{sub 3}Ir{sub 4}Sn{sub 13} at ambient pressure and above T* = 147 K adopts a simple cubic structure (I phase, Pm-3n). Below this temperature, the compound enters the I* phase, thought to result from a superlattice distortion of the I phase with twice the original lattice constant. We compare our quantum oscillation data for Sr{sub 3}Ir{sub 4}Sn{sub 13}, measured at a wide range of angles, with DFT calculations for the I and I* phases, as well as other proposed possibilities such as merohedral twining domains. We complement this comparison with thermal conductivity measurements of other materials in the family to provide important insights into the nature of the superlattice distortion.

La{sub 3}Cu{sub 4}P{sub 4}O{sub 2} and La{sub 5}Cu{sub 4}P{sub 4}O{sub 4}Cl{sub 2}. Synthesis, structure and {sup 31}P solid state NMR spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Bartsch, Timo; Eul, Matthias; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Benndorf, Christopher; Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. of Physics

2016-04-01

The phosphide oxides La{sub 3}Cu{sub 4}P{sub 4}O{sub 2} and La{sub 5}Cu{sub 4}P{sub 4}O{sub 4}Cl{sub 2} were synthesized from lanthanum, copper(I) oxide, red phosphorus, and lanthanum(III) chloride through a ceramic technique. Single crystals can be grown in a NaCl/KCl flux. Both structures were refined from single crystal X-ray diffractometer data: I4/mmm, a = 403.89(4), c = 2681.7(3) pm, wR2 = 0.0660, 269 F{sup 2} values, 19 variables for La{sub 3}Cu{sub 4}P{sub 4}O{sub 2} and a = 407.52(5), c = 4056.8(7) pm, wR2 = 0.0905, 426 F{sup 2} values, 27 variables for La{sub 5}Cu{sub 4}P{sub 4}O{sub 4}Cl{sub 2}. Refinement of the occupancy parameters revealed full occupancy for the oxygen sites in both compounds. The structures are composed of cationic (La{sub 2}O{sub 2}){sup 2+} layers and covalently bonded (Cu{sub 4}P{sub 4}){sup 5-} polyanionic layers with metallic characteristics, and an additional La{sup 3+} between two adjacent (Cu{sub 4}P{sub 4}){sup 5-} layers. The structure of La{sub 5}Cu{sub 4}P{sub 4}O{sub 4}Cl{sub 2} comprises two additional LaOCl slabs per unit cell. Temperature-dependent magnetic susceptibility studies revealed Pauli paramagnetism. The phosphide substructure of La{sub 3}Cu{sub 4}P{sub 4}O{sub 2} was studied by {sup 31}P solid state NMR spectroscopy. By using a suitable dipolar re-coupling approach the two distinct resonances belonging to the P{sub 2}{sup 4-} and the P{sup 3-} units could be identified.

Bandgap modulation in photoexcited topological insulator Bi{sub 2}Te{sub 3} via atomic displacements

Energy Technology Data Exchange (ETDEWEB)

Hada, Masaki, E-mail: hadamasaki@okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530 (Japan); Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); PRESTO, Japan Science and Technology Agency, Kawaguchi 332-0012 (Japan); Norimatsu, Katsura; Tsuruta, Tetsuya; Igarashi, Kyushiro; Kayanuma, Yosuke; Sasagawa, Takao; Nakamura, Kazutaka G. [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); Tanaka, Sei' ichi; Ishikawa, Tadahiko; Koshihara, Shin-ya [Department of Chemistry and Materials Science, Tokyo Institute of Technology, Tokyo 152-8551 (Japan); Keskin, Sercan [The Max Planck Institute for the Structure and Dynamics of Matter, The Hamburg Centre for Ultrafast Imaging, University of Hamburg, Hamburg 22761 (Germany); Miller, R. J. Dwayne [The Max Planck Institute for the Structure and Dynamics of Matter, The Hamburg Centre for Ultrafast Imaging, University of Hamburg, Hamburg 22761 (Germany); Departments of Chemistry and Physics, University of Toronto, Toronto M5S 3H6 (Canada); Onda, Ken [PRESTO, Japan Science and Technology Agency, Kawaguchi 332-0012 (Japan); Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama 226-8502 (Japan)

2016-07-14

The atomic and electronic dynamics in the topological insulator (TI) Bi{sub 2}Te{sub 3} under strong photoexcitation were characterized with time-resolved electron diffraction and time-resolved mid-infrared spectroscopy. Three-dimensional TIs characterized as bulk insulators with an electronic conduction surface band have shown a variety of exotic responses in terms of electronic transport when observed under conditions of applied pressure, magnetic field, or circularly polarized light. However, the atomic motions and their correlation between electronic systems in TIs under strong photoexcitation have not been explored. The artificial and transient modification of the electronic structures in TIs via photoinduced atomic motions represents a novel mechanism for providing a comparable level of bandgap control. The results of time-domain crystallography indicate that photoexcitation induces two-step atomic motions: first bismuth and then tellurium center-symmetric displacements. These atomic motions in Bi{sub 2}Te{sub 3} trigger 10% bulk bandgap narrowing, which is consistent with the time-resolved mid-infrared spectroscopy results.

Distinct ubiquitin binding modes exhibited by SH3 domains: molecular determinants and functional implications.

Directory of Open Access Journals (Sweden)

Jose L Ortega Roldan

Full Text Available SH3 domains constitute a new type of ubiquitin-binding domains. We previously showed that the third SH3 domain (SH3-C of CD2AP binds ubiquitin in an alternative orientation. We have determined the structure of the complex between first CD2AP SH3 domain and ubiquitin and performed a structural and mutational analysis to decipher the determinants of the SH3-C binding mode to ubiquitin. We found that the Phe-to-Tyr mutation in CD2AP and in the homologous CIN85 SH3-C domain does not abrogate ubiquitin binding, in contrast to previous hypothesis and our findings for the first two CD2AP SH3 domains. The similar alternative binding mode of the SH3-C domains of these related adaptor proteins is characterised by a higher affinity to C-terminal extended ubiquitin molecules. We conclude that CD2AP/CIN85 SH3-C domain interaction with ubiquitin constitutes a new ubiquitin-binding mode involved in a different cellular function and thus changes the previously established mechanism of EGF-dependent CD2AP/CIN85 mono-ubiquitination.

Three-State Ferroelastic Switching and Large Electromechanical Responses in PbTiO <sub>3sub> Thin Films

Energy Technology Data Exchange (ETDEWEB)

Damodaran, Anoop R. [Univ. of California, Berkeley, CA (United States); Pandya, Shishir [Univ. of California, Berkeley, CA (United States); Agar, Josh C. [Univ. of California, Berkeley, CA (United States); Cao, Ye [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Vasudevan, Rama K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Xu, Ruijuan [Univ. of California, Berkeley, CA (United States); Saremi, Sahar [Univ. of California, Berkeley, CA (United States); Li, Qian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kim, Jieun [Univ. of California, Berkeley, CA (United States); McCarter, Margaret R. [Univ. of California, Berkeley, CA (United States); Dedon, Liv R. [Univ. of California, Berkeley, CA (United States); Angsten, Tom [Univ. of California, Berkeley, CA (United States); Balke, Nina [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jesse, Stephen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Asta, Mark [Univ. of California, Berkeley, CA (United States); Kalinin, Sergei V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Martin, Lane W. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2017-07-31

Leveraging competition between energetically degenerate states to achieve large field-driven responses is a hallmark of functional materials, but routes to such competition are limited. Here, a new route to such effects involving domain-structure competition is demonstrated, which arises from straininduced spontaneous partitioning of PbTiO<sub>3sub> thin films into nearly energetically degenerate, hierarchical domain architectures of coexisting c/a and a<sub>1sub>/a>2sub> domain structures. Using band-excitation piezoresponse force microscopy, this study manipulates and acoustically detects a facile interconversion of different ferroelastic variants via a two-step, three-state ferroelastic switching process (out-of-plane polarized c+ → in-plane polarized a → out-of-plane polarized c- state), which is concomitant with large nonvolatile electromechanical strains (≈1.25%) and tunability of the local piezoresponse and elastic modulus (>23%). It is further demonstrated that deterministic, nonvolatile writing/erasure of large-area patterns of this electromechanical response is possible, thus showing a new pathway to improved function and properties.

Magnetic field control of 90°, 180°, and 360° domain wall resistance

Science.gov (United States)

Majidi, Roya

2012-10-01

In the present work, we have compared the resistance of the 90°, 180°, and 360° domain walls in the presence of external magnetic field. The calculations are based on the Boltzmann transport equation within the relaxation time approximation. One-dimensional Néel-type domain walls between two domains whose magnetization differs by angle of 90°, 180°, and 360° are considered. The results indicate that the resistance of the 360° DW is more considerable than that of the 90° and 180° DWs. It is also found that the domain wall resistance can be controlled by applying transverse magnetic field. Increasing the strength of the external magnetic field enhances the domain wall resistance. In providing spintronic devices based on magnetic nanomaterials, considering and controlling the effect of domain wall on resistivity are essential.

The Measurement and Role of Ecological Resilience Systems Theory Across Domain-Specific Outcomes: The Domain-Specific Resilient Systems Scales.

Science.gov (United States)

Maltby, John; Day, Liz; Hall, Sophie S; Chivers, Sally

2017-10-01

Research suggests that trait resilience may be best understood within an ecological resilient systems theory, comprising engineering, ecological, and adaptive capacity resilience. However, there is no evidence as to how this theory translates to specific life domains. Data from two samples (the United States, n = 1,278; the United Kingdom, n = 211) facilitated five studies that introduce the Domain-Specific Resilient Systems Scales for assessing ecological resilient systems theory within work, health, marriage, friendships, and education. The Domain-Specific Resilient Systems Scales are found to predict unique variance in job satisfaction, lower job burnout, quality-of-life following illness, marriage commitment, and educational engagement, while controlling for factors including sex, age, personality, cognitive ability, and trait resilience. The findings also suggest a distinction between the three resilience dimensions in terms of the types of systems to which they contribute. Engineering resilience may contribute most to life domains where an established system needs to be maintained, for example, one's health. Ecological resilience may contribute most to life domains where the system needs sustainability in terms of present and future goal orientation, for example, one's work. Adaptive Capacity may contribute most to life domains where the system needs to be retained, preventing it from reaching a crisis state, for example, work burnout.

Structural flexibility in magnetocaloric RE<sub>5sub>T>4sub> (RE=rare-earth; T=Si,Ge,Ga) materials: Effect of chemical substitution on structure, bonding and properties

Energy Technology Data Exchange (ETDEWEB)

Misra, Sumohan [Iowa State Univ., Ames, IA (United States)

2008-01-01

The binary, ternary and multicomponent intermetallic compounds of rare-earth metals (RE) with group 14 elements (Tt) at the RE<sub>5sub>Tt>4sub> stoichiometry have been known for over 30 years, but only in the past decade have these materials become a gold mine for solid-state chemistry, materials science and condensed matter physics. It all started with the discovery of a giant magnetocaloric effect in Gd<sub>5sub>Si>2sub>Ge>2sub>, along with other extraordinary magnetic properties, such as a colossal magnetostriction and giant magnetoresistance. The distinctiveness of this series is in the remarkable flexibility of the chemical bonding between well-defined, subnanometer-thick slabs and the resultant magnetic, transport, and thermodynamic properties of these materials. This can be controlled by varying either or both RE and Tt elements, including mixed rare-earth elements on the RE sites and different group 14 (or T = group 13 or 15) elements occupying the Tt sites. In addition to chemical means, the interslab interactions are also tunable by temperature, pressure, and magnetic field. Thus, this system provides a splendid 'playground' to investigate the interrelationships among composition, structure, physical properties, and chemical bonding. The work presented in this dissertation involving RE<sub>5sub>T>4sub> materials has resulted in the successful synthesis, characterization, property measurements, and theoretical analyses of various new intermetallic compounds. The results provide significant insight into the fundamental magnetic and structural behavior of these materials and help us better understand the complex link between a compound's composition, its observed structure, and its properties.

Stereochemical determinants of C-terminal specificity in PDZ peptide-binding domains: a novel contribution of the carboxylate-binding loop.

Science.gov (United States)

Amacher, Jeanine F; Cushing, Patrick R; Bahl, Christopher D; Beck, Tobias; Madden, Dean R

2013-02-15

PDZ (PSD-95/Dlg/ZO-1) binding domains often serve as cellular traffic engineers, controlling the localization and activity of a wide variety of binding partners. As a result, they play important roles in both physiological and pathological processes. However, PDZ binding specificities overlap, allowing multiple PDZ proteins to mediate distinct effects on shared binding partners. For example, several PDZ domains bind the cystic fibrosis (CF) transmembrane conductance regulator (CFTR), an epithelial ion channel mutated in CF. Among these binding partners, the CFTR-associated ligand (CAL) facilitates post-maturational degradation of the channel and is thus a potential therapeutic target. Using iterative optimization, we previously developed a selective CAL inhibitor peptide (iCAL36). Here, we investigate the stereochemical basis of iCAL36 specificity. The crystal structure of iCAL36 in complex with the CAL PDZ domain reveals stereochemical interactions distributed along the peptide-binding cleft, despite the apparent degeneracy of the CAL binding motif. A critical selectivity determinant that distinguishes CAL from other CFTR-binding PDZ domains is the accommodation of an isoleucine residue at the C-terminal position (P(0)), a characteristic shared with the Tax-interacting protein-1. Comparison of the structures of these two PDZ domains in complex with ligands containing P(0) Leu or Ile residues reveals two distinct modes of accommodation for β-branched C-terminal side chains. Access to each mode is controlled by distinct residues in the carboxylate-binding loop. These studies provide new insights into the primary sequence determinants of binding motifs, which in turn control the scope and evolution of PDZ interactomes.

The role of dysprosium on the structural and magnetic properties of (Nd{sub 1−x}Dy{sub x}){sub 2}Fe{sub 14}B nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Rahimi, Hamed; Ghasemi, Ali, E-mail: ali13912001@yahoo.com; Mozaffarinia, Reza; Tavoosi, Majid

2017-02-15

In current work, Nd2Fe14B nanoparticles was synthesized by sol-gel method. Dysprosium powders were added into Nd2Fe14B nanoparticles by mechanical alloying process in order to enhancement of coercivity. The phase analysis, structure, and magnetic properties of annealed (Nd{sub 1−x}Dy{sub x}){sub 2}Fe{sub 14}B nanoparticles with different Dy-content (x=0.1, 0.2, 0.3, 0.4, 0.5, 0.6) were investigated by employing X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive spectroscopy, field emission scanning electron microscope, transmission electron microscope and vibrating sample magnetometer techniques. The results showed that with an increase in Dy amounts, the coercivity of particles increased from 2.9 kOe to 13.4 kOe and then decreased to 5.6 kOe. By adding an optimum amount of Dy (x=0.4), the coercivity was significantly increased from 2.9 kOe to 13.4 kOe. The average particle size of annealed (Nd{sub 1−x}Dy{sub x}){sub 2}Fe{sub 14}B nanoparticles was below 10 nm. Magnetization reversal studies indicate that the coercivity of milled and annealed (Nd{sub 1−x}Dy{sub x}){sub 2}Fe{sub 14}B nanoparticles is controlled by the nucleation of reversed magnetic domains. The experimental results in the angular dependence of coercivity for (Nd{sub 1−x}Dy{sub x}){sub 2}Fe{sub 14}B permanent magnets showed that the normalized coercivity of the permanent magnets H{sub c}(θ)/H{sub c}(0) increases from 1 to about 1.2–1.5 with increasing θ from 0 to about π/3, for x=0.4–0.6. - Highlights: • Dy was added to Nd{sub 2}Fe{sub 14}B nanoparticles to improve the coercivity. • A maximum squareness ratio of 0.99 was obtained. • The average particle size decreased with an increase in Dy-content.

Birth of scale-free molecular networks and the number of distinct DNA and protein domains per genome.

Science.gov (United States)

Rzhetsky, A; Gomez, S M

2001-10-01

Current growth in the field of genomics has provided a number of exciting approaches to the modeling of evolutionary mechanisms within the genome. Separately, dynamical and statistical analyses of networks such as the World Wide Web and the social interactions existing between humans have shown that these networks can exhibit common fractal properties-including the property of being scale-free. This work attempts to bridge these two fields and demonstrate that the fractal properties of molecular networks are linked to the fractal properties of their underlying genomes. We suggest a stochastic model capable of describing the evolutionary growth of metabolic or signal-transduction networks. This model generates networks that share important statistical properties (so-called scale-free behavior) with real molecular networks. In particular, the frequency of vertices connected to exactly k other vertices follows a power-law distribution. The shape of this distribution remains invariant to changes in network scale: a small subgraph has the same distribution as the complete graph from which it is derived. Furthermore, the model correctly predicts that the frequencies of distinct DNA and protein domains also follow a power-law distribution. Finally, the model leads to a simple equation linking the total number of different DNA and protein domains in a genome with both the total number of genes and the overall network topology. MatLab (MathWorks, Inc.) programs described in this manuscript are available on request from the authors. ar345@columbia.edu.

Magnetostructural Phase Diagram of Multiferroic (ND<sub>4sub>)>2sub>FeCl>5sub>.H>2sub>O

Energy Technology Data Exchange (ETDEWEB)

Clune, A. [Univ. of Tennessee, Knoxville, TN (United States); Hughey, K. [Univ. of Tennessee, Knoxville, TN (United States); Musfeldt, J. L. [Univ. of Tennessee, Knoxville, TN (United States); Tian, W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fernandez-Baca, J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Singleton, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-02-13

Spin and polarization flop transitions are fascinating, especially when controlled by external stimuli like magnetic and electric field and accompanied by large material responses involving multiple degrees of freedom. Multiferroics like MnWO<sub>4sub>, TbMnO<sub>3sub>, and Ni<sub>3sub>TeO>6sub> are flagship examples and owe their remarkable properties, for instance field control of polarization and polarization flops combined with spin helix reorientation, to the anisotropy and heavy centers that bring in spin-orbit coupling. The family of A<sub>2sub>FeX>5sub>.H>2sub>O erythrosiderites (A = K, Rb, NH<sub>4sub>; B = Fe, Mn, Co; X = Cl, Br, H<sub>2sub>O) drew our attention due to the rich chemical tuning possibilities, complex phase diagrams, and topological similarities to oxide multiferroics.1 (NH<sub>4sub>)>2sub>FeCl>5sub>.H>2sub>O is the flagship example (Fig. 1(a)). It displays a high temperature order-disorder transition involving long-range hydrogen bonding of the NH<sub>4sub>⁺ group and two successive low temperature magnetic transitions below which non-collinear magnetic order and ferroelectricity are established.1 In addition to the magnetically-induced electric polarization that arises below 6.9 K (P = 3 μC/m<sub>2sub> along a and a smaller component along b), applied field reveals a peculiar hysteretic spin flop transition near 4.5 T above which polarization flops from the a- to the c-axis. There are elastic components as well. Taken together, these findings raise questions about the interactions that induce this behavior and whether additional non-equilibrium phases might be accessed under even higher magnetic fields.

Crystal structure of the β<sub>2sub> adrenergic receptor-Gs protein complex

Energy Technology Data Exchange (ETDEWEB)

Rasmussen, Søren G.F.; DeVree, Brian T; Zou, Yaozhong; Kruse, Andrew C; Chung, Ka Young; Kobilka, Tong Sun; Thian, Foon Sun; Chae, Pil Seok; Pardon, Els; Calinski, Diane; Mathiesen, Jesper M; Shah, Syed T.A.; Lyons, Joseph A; Caffrey, Martin; Gellman, Samuel H; Steyaert, Jan; Skiniotis, Georgios; Weis, William I; Sunahara, Roger K; Kobilka, Brian K [Brussels; (Trinity); (Michigan); (Stanford-MED); (Michigan-Med); (UW)

2011-12-07

G protein-coupled receptors (GPCRs) are responsible for the majority of cellular responses to hormones and neurotransmitters as well as the senses of sight, olfaction and taste. The paradigm of GPCR signalling is the activation of a heterotrimeric GTP binding protein (G protein) by an agonist-occupied receptor. The β<sub>2sub> adrenergic receptor (β<sub>2sub>AR) activation of Gs, the stimulatory G protein for adenylyl cyclase, has long been a model system for GPCR signalling. Here we present the crystal structure of the active state ternary complex composed of agonist-occupied monomeric β<sub>2sub>AR and nucleotide-free Gs heterotrimer. The principal interactions between the β<sub>2sub>AR and Gs involve the amino- and carboxy-terminal α-helices of Gs, with conformational changes propagating to the nucleotide-binding pocket. The largest conformational changes in the β<sub>2sub>AR include a 14Å outward movement at the cytoplasmic end of transmembrane segment 6 (TM6) and an α-helical extension of the cytoplasmic end of TM5. The most surprising observation is a major displacement of the α-helical domain of Gαs relative to the Ras-like GTPase domain. This crystal structure represents the first high-resolution view of transmembrane signalling by a GPCR.

NO{sub x} controls for coal-fired utility boilers in East Central Europe

Energy Technology Data Exchange (ETDEWEB)

Eskinazi, D. [Electric Power Research Inst., Washington, DC (United States); Tavoulareas, E.S. [Energy Technologies Enterprises Corp., McLean, VA (United States)

1995-12-01

Increasing environmental pressures worldwide, including East Central Europe are placing greater emphasis on NO{sub x} emission controls in utility power plants. Western Europe, Japan and the U.S. have significant experience in applying NO{sub x} controls, especially in boilers firing hard coal. Some countries in Europe (i.e., Germany and Austria), have gained experience in applying NO{sub x} controls in boilers firing low-rank coal. This experience can be applied to East Central European countries in providing the basis for planning NO{sub x} control projects, suggesting cost-effective solutions, and providing lessons learned. However, while the experience is generally applicable to East Central European countries, differences in boiler design, operation and coal characteristics also need to be considered. This paper begins with a comparison of the NO{sub x} regulations, identifies the key NO{sub x} control technologies and the worldwide experience with them, and discusses the achievable NO{sub x} reduction, O&M impacts, and retrofit costs for each technology. Emphasis is placed on retrofit applications for existing boilers, because new coal-fired power plants are not expected to be built for the next 5-10 years. This paper also focuses on technologies with relatively low cost and operational simplicity: combustion system tuning/optimization. low-NO{sub x} burners (LNB), overfire air (OFA), selective non-catalytic reduction (SNCR), and reburning.

Light induced superconductivity in underdoped YBa{sub 2}Cu{sub 3}O{sub x}

Energy Technology Data Exchange (ETDEWEB)

Kaiser, Stefan [Max-Planck-Institut fuer die Struktur und Dynamik der Materie, Hamburg (Germany); Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); 4. Physikalisches Institut und Research Center SCoPE, Uni Stuttgart (Germany); Nicoletti, Daniele; Hunt, Cassi; Hu, Wanzheng; Mankowsky, Roman; Foerst, Michael; Gierz, Isabella; Cavalleri, Andrea [Max-Planck-Institut fuer die Struktur und Dynamik der Materie, Hamburg (Germany); Loew, Toshinao; LeTacon, Mathieu; Keimer, Bernhard [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

2015-07-01

Photo-stimulation with femtosecond mid-infrared pulses allows us to induce an inhomogeneous non-equilibrium superconducting state in YBa{sub 2}Cu{sub 3}O{sub x} at temperatures as high as 300 K. Its transient response is probed via THz time-domain spectroscopy. We measure and characterize its complex optical response above and below the superconducting transition temperature T{sub c}: Below T{sub c}, we find an enhancement of the optical signatures of superconducting coherence. Above T{sub c} we find that the incoherent optical properties at equilibrium become highly coherent with optical signatures very similar to the ones for superconductors below T{sub c}. In the course of understanding these observations, ultrafast x-ray experiments at LCLS allow us observing reconstructed crystal structure in the transient superconducting state and the influence of competing CDW-order to the phonon-excitation.

Dissecting biochemical peculiarities of the ATPase activity of TcSub2, a component of the mRNA export pathway in Trypanosoma cruzi.

Science.gov (United States)

Bittencourt, Ize de Aguiar; Serpeloni, Mariana; Hiraiwa, Priscila Mazzochi; de Arruda Campos Brasil de Souza, Tatiana; Ávila, Andréa Rodrigues

2017-05-01

The RNA helicase DEAD-box protein Sub2 (yeast)/UAP56 (mammals) is conserved across eukaryotes and is essential for mRNA export in trypanosomes. Despite the high conservation of Sub2 in lower eukaryotes such as Trypanosoma cruzi, the low conservation of other mRNA export factors raises questions regarding whether the mode of action of TcSub2 is similar to that of orthologs from other eukaryotes. Mutation of the conserved K87 residue of TcSub2 abolishes ATPase activity, showing that its ATPase domain is functional. However, the Vmax of TcSub2 was much higher than the Vmax described for the human protein UAP56, which suggests that the TcSub2 enzyme hydrolyzes ATP faster than its human homolog. Furthermore, we demonstrate that RNA association is less important to the activity of TcSub2 compared to UAP56. Our results show differences in activity of this protein, even though the structure of TcSub2 is very similar to UAP56. Functional complementation assays indicate that these differences may be common to other trypanosomatids. Distinct features of RNA influence and ATPase efficiency between UAP56 and TcSub2 may reflect distinct structures for functional sites of TcSub2. For this reason, ligand-based or structure-based methodologies can be applied to investigate the potential of TcSub2 as a target for new drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

DC-SIGN neck domain is a pH-sensor controlling oligomerization: SAXS and hydrodynamic studies of extracellular domain.

Science.gov (United States)

Tabarani, Georges; Thépaut, Michel; Stroebel, David; Ebel, Christine; Vivès, Corinne; Vachette, Patrice; Durand, Dominique; Fieschi, Franck

2009-08-07

DC-SIGN is a C-type lectin receptor of dendritic cells and is involved in the early stages of numerous infectious diseases. DC-SIGN is organized into a tetramer enabling multivalent interaction with pathogens. Once formed, the DC-SIGN-pathogen complex can be internalized into compartments of increasing acidity. We have studied the pH dependence of the oligomerization state and conformation of the entire extracellular domain and neck region. We present evidence for equilibrium between the monomeric and tetrameric states of the extracellular domain, which exhibits a marked dependence with respect to both pH and ionic strength. Using solution x-ray scattering we have obtained a molecular envelope of the extracellular domain in which a model has been built. Our results highlight the central role of the neck domain in the pH-sensitive control of the oligomerization state, in the extended conformation of the protein, and in carbohydrate recognition domain organization and presentation. This work opens new insight into the molecular mechanism of ligand release and points to new avenues to block the first step of this important infection pathway.

Electric field induced lattice strain in pseudocubic Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-modified BaTiO{sub 3}-BiFeO{sub 3} piezoelectric ceramics

Energy Technology Data Exchange (ETDEWEB)

Fujii, Ichiro, E-mail: ifujii@rins.ryukoku.ac.jp [Department of Materials Chemistry, Ryukoku University, Otsu, Shiga 520-2194 (Japan); Iizuka, Ryo; Ueno, Shintaro; Nakashima, Kouichi; Wada, Satoshi [Interdisciplinary Graduate School of Medical and Engineering, University of Yamanashi, Kofu, Yamanashi 400-8510 (Japan); Nakahira, Yuki; Sunada, Yuya; Magome, Eisuke; Moriyoshi, Chikako; Kuroiwa, Yoshihiro [Department of Physical Science, Hiroshima University, Higashihiroshima, Hiroshima 739-8526 (Japan)

2016-04-25

Contributions to the piezoelectric response in pseudocubic 0.3BaTiO{sub 3}-0.1Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-0.6BiFeO{sub 3} ceramics were investigated by synchrotron X-ray diffraction under electric fields. All of the lattice strain determined from the 110, 111, and 200 pseudocubic diffraction peaks showed similar lattice strain hysteresis that was comparable to the bulk butterfly-like strain curve. It was suggested that the hysteresis of the lattice strain and the lack of anisotropy were related to the complex domain structure and the phase boundary composition.

Control of the superconducting properties of Sr{sub 2−x}Ca{sub x}VO{sub 3}FeAs through isovalent substitution

Energy Technology Data Exchange (ETDEWEB)

Corkett, Alex J.; Free, David G. [Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR (United Kingdom); Cassidy, Simon J. [Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR (United Kingdom); Diamond Light Source Limited, Harwell Science and Innovation Campus, Didcot, OX11 0DE (United Kingdom); Ramos, Silvia [Diamond Light Source Limited, Harwell Science and Innovation Campus, Didcot, OX11 0DE (United Kingdom); Clarke, Simon J., E-mail: simon.clarke@chem.ox.ac.uk [Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR (United Kingdom)

2014-08-15

The effect of the isovalent substitution of Sr{sup 2+} by Ca{sup 2+} on the structure and superconducting properties of Sr{sub 2−x}Ca{sub x}VO{sub 3}FeAs is described in the compositional range 0≤x≤0.5. SQUID magnetometry measurements reveal that after an initial increase in T{sub c}, which is maximised at 29.5 K in Sr{sub 1.95}Ca{sub 0.05}VO{sub 3}FeAs, a rapid suppression of superconductivity is observed with increasing x. XANES spectra of Sr{sub 2−x}Ca{sub x}VO{sub 3}FeAs collected on the Fe and V absorption K-edges show that the position of both edges are invariant with composition within the experimental uncertainty. A combination of synchrotron X-ray powder diffraction and neutron powder diffraction techniques is used to rationalise the observed changes in T{sub c} with x, in terms of changes to the structure of the FeAs layer upon partial Ca substitution. These findings demonstrate that superconductivity in the Fe-based superconductors is extremely sensitive to the crystal structure with T{sub c} maximised in samples with regular FeAs{sub 4}-tetrahedra. - Graphical abstract: Superconducting transition temperature is controlled by structural parameters in Sr{sub 2−x}Ca{sub x}VO{sub 3}FeAs. - Highlights: • Substitution of Sr by Ca in the superconductor Sr{sub 2}VO{sub 3}FeAs is isovalent. • Relationship between superconducting T{sub c} and structural parameters is demonstrated. • Linear dependence of T{sub c} on structural parameters rather than composition.

Influence of calcination temperature on Cd{sub 0.3}Co{sub 0.7}Fe{sub 2}O{sub 4} nanoparticles: Structural, thermal and magnetic properties

Energy Technology Data Exchange (ETDEWEB)

Reddy, Ch.Venkata, E-mail: cvrphy@gmail.com [School of Mechanical Engineering, Yeungnam University, 214-1, Dae-dong, Gyeongsan-si, Gyeongsangbuk-do 712-749 (Korea, Republic of); PrabhakarVattikuti, S.V. [School of Mechanical Engineering, Yeungnam University, 214-1, Dae-dong, Gyeongsan-si, Gyeongsangbuk-do 712-749 (Korea, Republic of); Ravikumar, R.V.S.S.N. [Department of Physics, Acharya Nagarjuna University, AP 522510 (India); Moon, Sang Jun, E-mail: nanobiomems@dgist.ac.kr [Cybernetics Laboratory, Daegu Gyeongbuk Institute of Science and Technology (DGIST) (Korea, Republic of); Shim, Jaesool, E-mail: jshim@ynu.ac.kr [School of Mechanical Engineering, Yeungnam University, 214-1, Dae-dong, Gyeongsan-si, Gyeongsangbuk-do 712-749 (Korea, Republic of)

2015-11-15

Cadmium substituted cobalt ferrite nanoparticles are synthesis using the chemical method. The as-prepared ferrite nanoparticles are calcinated at 300 °C and 600 °C respectively. The samples are studied using; Powder XRD, SEM with EDX, TEM, FT-IR, TG-DTA and vibrating sample magnetometer (VSM) in order to study the calcination temperature effect on structural, morphological and magnetic properties. The magnetic properties, like saturation magnetization and coercivity increases with increasing the calcination temperature. This enhancement is attributed to the transition from amulti-domain to a single-domain nature. The absorption bands observed at 588 cm{sup −1} (ν{sub 1}) and 440 cm{sup −1} (ν{sub 2}) are attributed to the vibrations of tetrahedral and octahedral complexes. The TG-DTA curves reveal the thermal stability of the prepared ferrite nanoparticles. The calcination temperature influences the magnetic properties, surface morphology and crystalline size. - Highlights: • Cd{sub 0.3}Co{sub 0.7}Fe{sub 2}O{sub 4} nanoparticles synthesized using the chemical co-precipitation. • The magnetization, coercivity values increases with increasing the calcination temperature. • The calcination temperature influences the magnetic properties and crystallite size. • The FTIR spectra results confirmed the vibrations of tetrahedral and octahedral complexes.

The BRCT domain is a phospho-protein binding domain.

Science.gov (United States)

Yu, Xiaochun; Chini, Claudia Christiano Silva; He, Miao; Mer, Georges; Chen, Junjie

2003-10-24

The carboxyl-terminal domain (BRCT) of the Breast Cancer Gene 1 (BRCA1) protein is an evolutionarily conserved module that exists in a large number of proteins from prokaryotes to eukaryotes. Although most BRCT domain-containing proteins participate in DNA-damage checkpoint or DNA-repair pathways, or both, the function of the BRCT domain is not fully understood. We show that the BRCA1 BRCT domain directly interacts with phosphorylated BRCA1-Associated Carboxyl-terminal Helicase (BACH1). This specific interaction between BRCA1 and phosphorylated BACH1 is cell cycle regulated and is required for DNA damage-induced checkpoint control during the transition from G2 to M phase of the cell cycle. Further, we show that two other BRCT domains interact with their respective physiological partners in a phosphorylation-dependent manner. Thirteen additional BRCT domains also preferentially bind phospho-peptides rather than nonphosphorylated control peptides. These data imply that the BRCT domain is a phospho-protein binding domain involved in cell cycle control.

Influence of lattice distortion on the Curie temperature and spin-phonon coupling in LaMn{sub 0.5}Co{sub 0.5}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Viswanathan, M; Anil Kumar, P S [Department of Physics, Indian Institute of Science, Bangalore 560012 (India); Bhadram, Venkata Srinu; Narayana, Chandrabhas [Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064 (India); Bera, A K; Yusuf, S M, E-mail: viswanathan.mohandoss@yahoo.co, E-mail: anil@physics.iisc.ernet.i [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2010-09-01

Two distinct ferromagnetic phases of LaMn{sub 0.5}Co{sub 0.5}O{sub 3} having monoclinic structure with distinct physical properties have been studied. The ferromagnetic ordering temperature T{sub c} is found to be different for both the phases. The origin of such contrasting characteristics is assigned to the changes in the distance(s) and angle(s) between Mn-O-Co resulting from distortions observed from neutron diffraction studies. Investigations on the temperature dependent Raman spectroscopy provide evidence for such structural characteristics, which affects the exchange interaction. The difference in B-site ordering which is evident from the neutron diffraction is also responsible for the difference in T{sub c}. Raman scattering suggests the presence of spin-phonon coupling for both the phases around the T{sub c}. Electrical transport properties of both the phases have been investigated based on the lattice distortion.

Accumulation of raft lipids in T-cell plasma membrane domains engaged in TCR signalling

DEFF Research Database (Denmark)

Zech, Tobias; Ejsing, Christer S.; Gaus, Katharina

2009-01-01

Activating stimuli for T lymphocytes are transmitted through plasma membrane domains that form at T-cell antigen receptor (TCR) signalling foci. Here, we determined the molecular lipid composition of immunoisolated TCR activation domains. We observed that they accumulate cholesterol, sphingomyelin...... and saturated phosphatidylcholine species as compared with control plasma membrane fragments. This provides, for the first time, direct evidence that TCR activation domains comprise a distinct molecular lipid composition reminiscent of liquid-ordered raft phases in model membranes. Interestingly, TCR activation...... domains were also enriched in plasmenyl phosphatidylethanolamine and phosphatidylserine. Modulating the T-cell lipidome with polyunsaturated fatty acids impaired the plasma membrane condensation at TCR signalling foci and resulted in a perturbed molecular lipid composition. These results correlate...

Essential and distinct roles of the F-box and helicase domains of Fbh1 in DNA damage repair

Directory of Open Access Journals (Sweden)

Shinagawa Hideo

2008-03-01

Full Text Available Abstract Background DNA double-strand breaks (DSBs are induced by exogenous insults such as ionizing radiation and chemical exposure, and they can also arise as a consequence of stalled or collapsed DNA replication forks. Failure to repair DSBs can lead to genomic instability or cell death and cancer in higher eukaryotes. The Schizosaccharomyces pombe fbh1 gene encodes an F-box DNA helicase previously described to play a role in the Rhp51 (an orthologue of S. cerevisiae RAD51-dependent recombinational repair of DSBs. Fbh1 fused to GFP localizes to discrete nuclear foci following DNA damage. Results To determine the functional roles of the highly conserved F-box and helicase domains, we have characterized fbh1 mutants carrying specific mutations in these domains. We show that the F-box mutation fbh1-fb disturbs the nuclear localization of Fbh1, conferring an fbh1 null-like phenotype. Moreover, nuclear foci do not form in fbh1-fb cells with DNA damage even if Fbh1-fb is targeted to the nucleus by fusion to a nuclear localization signal sequence. In contrast, the helicase mutation fbh1-hl causes the accumulation of Fbh1 foci irrespective of the presence of DNA damage and confers damage sensitivity greater than that conferred by the null allele. Additional mutation of the F-box alleviates the hypermorphic phenotype of the fbh1-hl mutant. Conclusion These results suggest that the F-box and DNA helicase domains play indispensable but distinct roles in Fbh1 function. Assembly of the SCFFbh1 complex is required for both the nuclear localization and DNA damage-induced focus formation of Fbh1 and is therefore prerequisite for the Fbh1 recombination function.

Structural, optical and spectroscopical investigations into rare-earths perowskites RGaO{sub 3} (R=La, Pr, Nd) and NdBa-2Cu{sub 3}O{sub 7-{delta}}; Strukturelle, optische und spektroskopische Untersuchungen von Seltenen-Erd-Perowskiten RGaO{sub 3} (R=La, Pr, Nd) und NdBa{sub 2}Cu{sub 3}O{sub 7-{delta}}

Energy Technology Data Exchange (ETDEWEB)

Marti, W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1995-07-01

In this work I was engaged in rare-earth perovskites. Primarily I investigated the structure of the rare-earth gallates RGaO{sub 3} (R=La, Pr, Nd) as a function of the temperature by means of neutron diffraction and x-ray diffraction. As the high-T{sub c} superconductors these compounds belong to the family of the perovskites, they are ferroelastic and centro-symmetric. Because of the lanthanide-contraction all lattice constants and distortion parameters change systematically. The rare-earth-gallates RGaO{sub 3} (R=La, Pr, Nd) are promising substrates for epitaxy of high-T{sub c} superconductors like RBa{sub 2}Cu{sub 3}OO{sub 7-{delta}} because of their structure parameters and expansion coefficients. I succeeded in producing plane-parallel single-domain crystals by means of uniaxial stress. The first order phase transition was observable only in LaGaO{sub 3}. A structurally phase transition from orthorhombic to rhombohedral symmetry (high-temperature phase) occurs at 423 K. The hysteresis of the phase transition temperature of about 1.5 K was measured with single-domain crystals by means of neutron diffraction and polarized light microscopy. In NdGaO{sub 3} we determined the long-range, three-dimensional, antiferromagnetic ordering of the Nd{sup 3+}-ions below the ordering temperature at T{sub N}=0.97 K by means of magnetic neutron diffraction. The spin configuration could be described by a (--c{sub z})-mode. Measurements of the magnetic susceptibility confirm the easy direction of magnetization to be the c-axis. Below 300mK an additional nuclear spin polarization due to the hyperfine-interaction appears parallel to the electronic spins, which amounts to 70% at 10mK. Further I investigated the optical properties of the rare-earth gallates. The birefringence of plane-parallel, polished single-domain crystals with thickness up to 300 {mu}m was measured by means of orthoscopy and conoscopy. (author) figs., tabs., refs.

Probing the ground state and zero-field cooled exchange bias by magnetoresistance measurement in Mn{sub 50}Ni{sub 41}Sn{sub 9} ribbon

Energy Technology Data Exchange (ETDEWEB)

Chen, Jiyun [Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500 (China); School of Materials Science and Engineering, China University of Mining & Technology, Xuzhou 221116 (China); Tu, Ruikang [Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500 (China); School of Materials Science and Engineering, Soochow University, Suzhou 215000 (China); Fang, Xiaoting [Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500 (China); Gu, Quanchao [Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500 (China); School of Materials Science and Engineering, Soochow University, Suzhou 215000 (China); Zhou, Yanying [Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500 (China); Cui, Rongjing [Department of Chemistry, Changshu Institute of Technology, Changshu 215500 (China); Han, Zhida, E-mail: han@cslg.edu.cn [Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500 (China); Zhang, Lei; Fang, Yong [Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500 (China); Qian, Bin, E-mail: njqb@cslg.edu.cn [Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500 (China); Zhang, Chengliang [School of Science, Jiangnan University, Wuxi 214122 (China); Jiang, Xuefan [Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500 (China)

2017-03-15

Recently, a new type of exchange bias (EB) after zero-field cooling has attracted considerable interest mainly in bulk magnetic competing systems. Here, we use a detailed magnetotransport investigation to probe the ground state and zero-field cooled EB (ZEB) in Mn{sub 50}Ni{sub 41}Sn{sub 9} ribbon. Both ZEB and field cooled EB were detected in magnetoresistance results consistent with magnetic measurement. A pure spin-glass ground state is proposed based on parabolic shape of low-field magnetoresistance combined with AC magnetization, memory effect. The appearance of ZEB is attributed to the field-induced nucleation and growth of ferromagnetic domains in the spin glass matrix forming unidirectional anisotropy at the interface. - Highlights: • Magnetoresistance was first used to probe the ground state and ZEB in Ni-Mn-based alloys. • A pure spin-glass ground state is proposed in Mn{sub 50}Ni{sub 41}Sn{sub 9} ribbon. • Field-induced nucleation and growth of ferromagnetic domains in SG results in ZEB.

Automated retinal fovea type distinction in spectral-domain optical coherence tomography of retinal vein occlusion

Science.gov (United States)

Wu, Jing; Waldstein, Sebastian M.; Gerendas, Bianca S.; Langs, Georg; Simader, Christian; Schmidt-Erfurth, Ursula

2015-03-01

Spectral-domain Optical Coherence Tomography (SD-OCT) is a non-invasive modality for acquiring high- resolution, three-dimensional (3D) cross-sectional volumetric images of the retina and the subretinal layers. SD-OCT also allows the detailed imaging of retinal pathology, aiding clinicians in the diagnosis of sight degrading diseases such as age-related macular degeneration (AMD), glaucoma and retinal vein occlusion (RVO). Disease diagnosis, assessment, and treatment will require a patient to undergo multiple OCT scans, possibly using multiple scanners, to accurately and precisely gauge disease activity, progression and treatment success. However, cross-vendor imaging and patient movement may result in poor scan spatial correlation potentially leading to incorrect diagnosis or treatment analysis. The retinal fovea is the location of the highest visual acuity and is present in all patients, thus it is critical to vision and highly suitable for use as a primary landmark for cross-vendor/cross-patient registration for precise comparison of disease states. However, the location of the fovea in diseased eyes is extremely challenging to locate due to varying appearance and the presence of retinal layer destroying pathology. Thus categorising and detecting the fovea type is an important prior stage to automatically computing the fovea position. Presented here is an automated cross-vendor method for fovea distinction in 3D SD-OCT scans of patients suffering from RVO, categorising scans into three distinct types. OCT scans are preprocessed by motion correction and noise filing followed by segmentation using a kernel graph-cut approach. A statistically derived mask is applied to the resulting scan creating an ROI around the probable fovea location from which the uppermost retinal surface is delineated. For a normal appearance retina, minimisation to zero thickness is computed using the top two retinal surfaces. 3D local minima detection and layer thickness analysis are used

Unfolding of a Temperature-Sensitive Domain Controls Voltage-Gated Channel Activation.

Science.gov (United States)

Arrigoni, Cristina; Rohaim, Ahmed; Shaya, David; Findeisen, Felix; Stein, Richard A; Nurva, Shailika Reddy; Mishra, Smriti; Mchaourab, Hassane S; Minor, Daniel L

2016-02-25

Voltage-gated ion channels (VGICs) are outfitted with diverse cytoplasmic domains that impact function. To examine how such elements may affect VGIC behavior, we addressed how the bacterial voltage-gated sodium channel (BacNa(V)) C-terminal cytoplasmic domain (CTD) affects function. Our studies show that the BacNa(V) CTD exerts a profound influence on gating through a temperature-dependent unfolding transition in a discrete cytoplasmic domain, the neck domain, proximal to the pore. Structural and functional studies establish that the BacNa(V) CTD comprises a bi-partite four-helix bundle that bears an unusual hydrophilic core whose integrity is central to the unfolding mechanism and that couples directly to the channel activation gate. Together, our findings define a general principle for how the widespread four-helix bundle cytoplasmic domain architecture can control VGIC responses, uncover a mechanism underlying the diverse BacNa(V) voltage dependencies, and demonstrate that a discrete domain can encode the temperature-dependent response of a channel. Copyright © 2016 Elsevier Inc. All rights reserved.

Local Atomic Structure and Discommensurations in the Charge Density Wave of CeTe{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Kim, H J; Tomic, A T; Tessmer, S H; Billinge, S J.L. [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Malliakas, C D; Kanatzidis, M G [Department of Chemistry, Michigan State University, East Lansing, Michigan 48824 (United States)

2006-06-09

The local structure of CeTe{sub 3} in the incommensurate charge density wave (IC-CDW) state has been obtained using atomic pair distribution function analysis of x-ray diffraction data. Local atomic distortions in the Te nets due to the CDW are larger than observed crystallographically, resulting in distinct short and long Te-Te bonds. Observation of different distortion amplitudes in the local and average structures is explained by the discommensurated nature of the CDW, since the pair distribution function is sensitive to the local displacements within the commensurate regions, whereas the crystallographic result averages over many discommensurated domains. The result is supported by STM data. This is the first quantitative local structural study within the commensurate domains in an IC-CDW system.

Growth of ultrathin twin-free b-oriented YBa{sub 2}Cu{sub 3}O{sub 7} {sub –} {sub x} films

Energy Technology Data Exchange (ETDEWEB)

Stepantsov, E. A., E-mail: stepantsov@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics,” (Russian Federation); Arpaia, R.; Lombardi, F. [Chalmers University of Technology, Department of Microtechnology and Nanoscience (Sweden)

2017-01-15

Twin-free b-oriented YBa{sub 2}Cu{sub 3}O{sub 7–x} films with a thickness less than 40 nm have been epitaxially grown on (100)SrLaGaO{sub 4} crystals. Based on the temperature dependence of resistance, the onset temperature of the transition to the superconducting state is found to be 90 K; the transition width is 4 K. The film growth has been performed in two stages. A (100)PrBa{sub 2}Cu{sub 3}O{sub 7–x} buffer layer was previously grown on a (100)SrLaGaO{sub 4} substrate by rf magnetron sputtering in an Ar–O{sub 2} gas mixture at a continuous and monotonic increase in temperature from 660 to 830°C. The main YBa{sub 2}Cu{sub 3}O{sub 7–x} film was grown on the buffer layer surface by pulsed laser deposition in an oxygen medium at a fixed temperature (800°C). The above processes were implemented in different chambers, which were connected by a vacuum channel for transporting samples. Both films were grown in situ, without contacting atmosphere in all growth stages. An X-ray diffraction study has shown that the YBa{sub 2}Cu{sub 3}O{sub 7–x} films are single-crystal and free of precipitates of other phases and domains of other orientations.

Magnetic properties improvement of melt spun Co{sub 86.5}Hf{sub 11.5}B{sub 2} nanocomposites by refractory elements substitution

Energy Technology Data Exchange (ETDEWEB)

Chang, H.W. [Department of Applied Physics, Tunghai University, Taichung 407, Taiwan (China); Lin, Y.H.; Shih, C.W.; Liao, M.C.; Lee, Y.I. [Department of Physics, National Chung Cheng University, Chia-Yi 621, Taiwan (China); Chang, W.C., E-mail: phywcc@ccu.edu.tw [Department of Physics, National Chung Cheng University, Chia-Yi 621, Taiwan (China); Yang, C.C. [Department of Physics, Chung-Yuan Christian University, Chungli 320, Taiwan (China); Shaw, C.C. [Superrite Electronics Co. Ltd., Taipei 111, Taiwan (China)

2016-03-01

Magnetic properties of melt spun Co{sub 86.5}Hf{sub 10.5}MB{sub 2} ribbons with refractory elements substitution (M=Cr, Nb, Ti, Zr) have been studied. For ternary Co{sub 86.5}Hf{sub 11.5}B{sub 2} ribbon, permanent magnetic properties of B{sub r}=0.71 T, {sub i}H{sub c}=192 kA/m, and (BH){sub max}=34.4 kJ/m{sup 3} are obtained, and they are significantly improved to B{sub r}=0.73–0.76 T, {sub i}H{sub c}=136–216 kA/m and (BH){sub max}=38.4–52.8 kJ/m{sup 3} with M substitution. Summarized with the results of x-ray diffraction refinement, thermal magnetic analysis, and transmission electron microscopy, the Co{sub 86.5}Hf{sub 10.5}MB{sub 2} nanocomposites following the optimal crystallization treatment mainly consist of orthorhombic 7:1 and face-center-cubic Co phases. Fine microstructure with average grain size in the range of 12.5−19.6 nm promotes exchange coupling effect between magnetic grains, thus improving permanent magnetic properties. The magnetic field dependence of coercivity reveals that coercivity of the studied Co{sub 86.5}Hf{sub 10.5}MB{sub 2} nonocomposites is mainly governed by the reverse domain nucleation mechanism. - Highlights: • M substitution refines the grain size. • M substitution strengthens the exchange coupling effect between grains. • M substitution improves hard magnetic properties of Co{sub 86.5}Hf{sub 10.5}MB{sub 2} ribbons. • The coercivity is mainly governed by the reverse domain nucleation mechanism. • Co{sub 86.5}Hf{sub 10.5}MB{sub 2} ribbons are relevant candidate for RE free permanent magnets.

Membrane domains and polarized trafficking of sphingolipids

NARCIS (Netherlands)

Maier, O; Slimane, TA; Hoekstra, D

The plasma membrane of polarized cells consists of distinct domains, the apical and basolateral membrane that are characterized by a distinct lipid and protein content. Apical protein transport is largely mediated by (glyco)sphingolipid-cholesterol enriched membrane microdomains, so called rafts. In

Adsorption-controlled growth of Bi{sub 4}Ti{sub 3}O{sub 12} by reactive MBE

Energy Technology Data Exchange (ETDEWEB)

Theis, C.D.; Yeh, J.; Schlom, D.G. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802-5005 (United States); Hawley, M.E.; Brown, G.W. [Center for Materials Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Jiang, J.C.; Pan, X.Q. [University of Michigan, Department of Materials Science and Engineering, Ann Arbor, Michigan 48109-2136 (United States)

1998-06-01

Adsorption-controlled conditions have been identified and utilized to grow epitaxial bismuth titanate thin films by reactive molecular beam epitaxy. Growth of stoichiometric, phase pure, c-axis oriented, epitaxial films is achieved by supplying a large overabundance of bismuth and ozone continuously to the surface of the depositing film. Titanium is supplied to the film in the form of shuttered bursts each containing a three monolayer dose of titanium to grow one formula unit of Bi{sub 4}Ti{sub 3}O{sub 12}. It is seen from measured film thickness, Rutherford backscattering spectrometry composition measurements, monitoring of reflection high-energy electron diffraction half-order intensity oscillations during growth, and {ital in situ} flux measurements using atomic absorption spectroscopy that at suitable temperature and ozone background pressure, the titanium sticking coefficient approaches one and the excess bismuth desorbs from the surface. Film growth proceeds by the formation of mounds whose step heights are predominantly integral multiples of a half-unit cell.{copyright} {ital 1998 American Institute of Physics.}

Kinetic control in the synthesis of metastable polymorphs: Bixbyite-to-Rh{sub 2}O{sub 3}(II)-to-corundum transition in In{sub 2}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Bekheet, Maged F., E-mail: maged.bekheet@ceramics.tu-berlin.de [Fachbereich Material -und Geowissenschaften, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Fachgebiet Keramische Werkstoffe, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin (Germany); Schwarz, Marcus R. [Freiberg High Pressure Research Centre, Institut für Anorganische Chemie, Technische Universität-Bergakademie Freiberg, Leipziger Straße 29, 09599 Freiberg (Germany); Kroll, Peter [Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX 760019-0065 (United States); Gurlo, Aleksander [Fachbereich Material -und Geowissenschaften, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Fachgebiet Keramische Werkstoffe, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin (Germany)

2015-09-15

An example for kinetic control of a solid-state phase transformation, in which the system evolves via the path with the lowest activation barrier rather than ending in the thermodynamically most favorable state, has been demonstrated. As a case study, the phase transitions of indium sesquioxide (In{sub 2}O{sub 3}) have been guided by theoretical calculations and followed in situ under high-pressure high-temperature conditions in multi-anvil assemblies. The corundum-type rh-In{sub 2}O{sub 3} has been synthesized from stable bixbyite-type c-In{sub 2}O{sub 3} in two steps: first generating orthorhombic Rh{sub 2}O{sub 3}-II-type o′-In{sub 2}O{sub 3} which is thermodynamically stable at 8.5 GPa/850 °C and, thereafter, exploiting the preferred kinetics in the subsequent transformation to the rh-In{sub 2}O{sub 3} during decompression. This synthesis strategy of rh-In{sub 2}O{sub 3} was confirmed ex situ in a toroid-type high-pressure apparatus at 8 GPa and 1100 °C. The pressure–temperature phase diagrams have been constructed and the stability fields of In{sub 2}O{sub 3} polymorphs and the crystallographic relationship between them have been discussed. - Graphical abstract: In situ energy-dispersive XRD patterns in multi-anvil assemblies show the sequence of phase transition c-In{sub 2}O{sub 3}→o′-In{sub 2}O{sub 3}→rh-In{sub 2}O{sub 3} under particular pressure and temperature conditions. The tick marks refer to the calculated Bragg positions of bixbyite-type (c-In{sub 2}O{sub 3}), Rh{sub 2}O{sub 3}-II-type (o–-In2O{sub 3}) and corundum-type (rh-In{sub 2}O{sub 3}). - Highlights: • The solid-state synthesis methods can be employed for obtaining metastable phases. • The phase transition of In{sub 2}O{sub 3} was guided by DFT calculations. • The phase transition of In{sub 2}O{sub 3} was followed in situ under HP–HT conditions. • Orthorhombic o′-In{sub 2}O{sub 3} polymorph was synthesized from c-In{sub 2}O{sub 3} at 8.5 GPa/850 °C. • Metastable rh-In{sub

Investigation of the temperature-dependence of ferromagnetic resonance and spin waves in Co{sub 2}FeAl{sub 0.5}Si{sub 0.5}

Energy Technology Data Exchange (ETDEWEB)

Loong, Li Ming; Kwon, Jae Hyun; Deorani, Praveen; Yang, Hyunsoo, E-mail: eleyang@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, 117576 Singapore (Singapore); Tung Yu, Chris Nga [Department of Physics, The University of York, York YO10 5DD (United Kingdom); Hirohata, Atsufumi, E-mail: atsufumi.hirohata@york.ac.uk [Department of Electronics, The University of York, York YO10 5DD (United Kingdom)

2014-06-09

Co{sub 2}FeAl{sub 0.5}Si{sub 0.5} (CFAS) is a Heusler compound that is of interest for spintronics applications, due to its high spin polarization and relatively low Gilbert damping constant. In this study, the behavior of ferromagnetic resonance as a function of temperature was investigated in CFAS, yielding a decreasing trend of damping constant as the temperature was increased from 13 to 300 K. Furthermore, we studied spin waves in CFAS using both frequency domain and time domain techniques, obtaining group velocities and attenuation lengths as high as 26 km/s and 23.3 μm, respectively, at room temperature.

Magnetic performance of orthorhombic Mn{sub 35}Ge{sub 35}Te{sub 30} nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Mahdy, Iman A.

2017-01-15

Nanocrystalline antiferromagnetic Mn{sub 35}Ge{sub 35}Te{sub 30} diluted magnetic semiconductors powder syntheses by the conventional direct reaction of pure metals. Nanocrystalline nature of the prepared sample confirmed using various techniques, where x-Ray diffraction (XRD) and atomic force microscope (AFM) measurements shows ~96 nm particle size, while transmission electron microscope (TEM) shows 92 nm particle size. XRD analysis show orthorhombic symmetry with lattice parameters a=7.386611±(0.0066) Å, b=8.962502±(0.0090) Å and c=7.027349±(0.0040) Å. Electron Spin resonance (ESR) show a broad asymmetric line whereas the remnant Mn{sup 2+} six-hyperfine lines are broadened within |+1/2>→|−1/2> line according to high anisotropy; calculated Landé g-factor is 2.047. Vibrating sample magnetometer (VSM) analysis, field-moment characteristics revealed a hysteresis loop with small coercive field indicating that Mn{sub 35}Ge{sub 35}Te{sub 30} is a soft magnetic material. Moreover, hysteresis measurements at different temperatures show increasing magnetization with increasing temperature up to 150 K followed by decreased with increasing temperature up to 300 K. This behavior indicated to the antiferromagnetic nature of the prepared nanocrystalline materials. Magnetic moment – temperature measurements show Néel temperature T{sub N}=172.6 K. Magnetic force microscope revealed magnetic domains as a result of interaction between magnetic dipole moments of magnetic cantilever and pressed powder. - Highlights: • Nanocrystalline diluted magnetic semiconductors of new Mn-Ge-Te orthorhombic phase. • Soft magnetic materials for a magnetic core of many devices. • Mixture of ferromagnetic and antiferromagnetic. • Asymmetry in hysteresis loop explained by the exchange bias of domain spins.

Diffuse scattering from an Al sub 7 sub 2 Ni sub 2 sub 0 Co sub 8 decagonal quasicrystal on an order-disorder transformation

CERN Document Server

Abe, H; Ueno, T; Nakao, H; Matsuo, Y; Ohshima, K; Matsumoto, H

2003-01-01

Non-uniform distortion induced by superstructure domains has been observed during the ordering process of an order-disorder transformation in a single decagonal quasicrystal of Al sub 7 sub 2 Ni sub 2 sub 0 Co sub 8. The full width at half maximum (FWHM) of the fundamental reflections increased below the transformation temperature, T sub c. At the same time, the integrated intensity of the fundamental reflections varied drastically at T sub c. A small hysteresis was also observed in the temperature dependences of both the FWHM and the integrated intensity of the fundamental reflections. Peak broadening of the fundamental reflections is predominantly dependent on |G sup p sup a sup r | below T sub c. In addition, the weak dependence of the peak broadening with |G sup p sup e sup r sup p | is extracted from the observed FWHM of the fundamental reflections. After deconvolution, the FWHM of the fundamental reflections appears to be a linear combination of |G sup p sup a sup r | and |G sup p sup e sup r sup p |. C...

Field-induced strain memory with non-180 .deg. domain-reorientation control

International Nuclear Information System (INIS)

Kadota, Yoichi; Hosaka, Hiroshi; Morita, Takeshi

2010-01-01

Using non-180 .deg. domain-reorientation control, we propose the strain memory effect in ferroelectric ceramics. Electric fields with asymmetric amplitudes were applied to soft-type lead zirconate titanate (PZT) ceramics, and the strain hysteresis and the polarization loop were measured. The butterfly curve became asymmetric under an electric field with a particular asymmetric amplitude. The asymmetric butterfly curve had two stable strain states at zero electric field. Thus, the strain memory effect was realized as the difference between the two stable strain states. An XRD analysis was carried out to verify the contribution of the non-180 .deg. domain reorientation to the strain memory effect. The non-180 .deg. domain reorientation was determined as the intensity ratio of the (002) to the (200) peak. The strain memory determined from macroscopic strain measurements had a linear relationship to the non-180 .deg. domain volume fraction. This result indicated the origin of the strain memory to be the non-180 .deg. domain reorientation.

Superparamagnetic behavior of nanosized Co{sub 0.2}Zn{sub 0.8}Fe{sub 2}O{sub 4} synthesized by a flow rate controlled chemical coprecipitation method

Energy Technology Data Exchange (ETDEWEB)

Dey, S. [Department of Physics, Jadavpur University, Kolkata 700032 (India); Dey, S.K. [Department of Physics, Jadavpur University, Kolkata 700032 (India); Department of Physics, NITMAS, 24 Pargana(s) 743368 (India); Majumder, S. [Department of Physics, Jadavpur University, Kolkata 700032 (India); Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Poddar, A.; Dasgupta, P.; Banerjee, S. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Kumar, S., E-mail: kumars@phys.jdvu.ac.in [Department of Physics, Jadavpur University, Kolkata 700032 (India)

2014-09-01

We have studied the structural, microstructural and magnetic properties of nanosized (∼20 nm) Co{sub 0.2}Zn{sub 0.8}Fe{sub 2}O{sub 4} synthesized by a flow rate controlled coprecipitation method. The phase purity and crystallinity of the sample have been confirmed by powder X-ray diffraction and high resolution transmission electron microscopic studies. According to the results of dc magnetic measurements the sample exhibits superparamagnetic behavior above 70 K due to its nanometric size. This has been corroborated by Mössbauer spectroscopic study at 300 K. The infield Mössbauer spectroscopic study indicates that the sample behaves ferrimagnetically at 10 K and it possesses equilibrium cation distribution. The saturation magnetization of the sample (M{sub SAT}∼32 emu g{sup −1} at 300 K) is substantially lower than its bulk counterpart (M{sub SAT}=80 emu g{sup −1}) but higher than those having same composition synthesized by the conventional coprecipitation method. This has been attributed to finite size and spin canting effects as well as good crystalline character and bulk like equilibrium cation distribution of the sample. We have shown that the flow rate controlled coprecipitation method can produce nanosized ferrites with very good crystalline order and equilibrium cation distribution but they exhibit reduction of magnetization, magnetic order and ordering temperature compared to their bulk counterparts due to spin canting effect and finite size effect.

Surfactant-controlled synthesis of Pd/Ce{sub 0.6}Zr{sub 0.4}O{sub 2} catalyst for NO reduction by CO with excess oxygen

Energy Technology Data Exchange (ETDEWEB)

Chen, L.F. [Laboratorio de Catalisis y Materiales, SEPI-ESIQIE, Instituto Politecnico Nacional, Av. Politecnico S/N, Col. Zacatenco, 07738 Mexico D.F. (Mexico); Departamento de Ingenieria Quimica, Universidad Autonoma Metropolitana-A, Av. San Pablo 180, Col. Reynosa-Tamaulipas, 02200 Mexico D.F. (Mexico); Gonzalez, G. [Laboratorio de Catalisis y Materiales, SEPI-ESIQIE, Instituto Politecnico Nacional, Av. Politecnico S/N, Col. Zacatenco, 07738 Mexico D.F. (Mexico); Wang, J.A. [Laboratorio de Catalisis y Materiales, SEPI-ESIQIE, Instituto Politecnico Nacional, Av. Politecnico S/N, Col. Zacatenco, 07738 Mexico D.F. (Mexico)]. E-mail: jwang@ipn.mx; Norena, L.E. [Departamento de Ingenieria Quimica, Universidad Autonoma Metropolitana-A, Av. San Pablo 180, Col. Reynosa-Tamaulipas, 02200 Mexico D.F. (Mexico); Toledo, A. [Grupo de Molecular Ingenieria, Instituto Mexicano del Petroleo, Eje Lazaro Cardenas 152, 07730 Mexico D.F. (Mexico); Castillo, S. [Grupo de Molecular Ingenieria, Instituto Mexicano del Petroleo, Eje Lazaro Cardenas 152, 07730 Mexico D.F. (Mexico); Moran-Pineda, M. [Grupo de Molecular Ingenieria, Instituto Mexicano del Petroleo, Eje Lazaro Cardenas 152, 07730 Mexico D.F. (Mexico)

2005-04-30

For the first time, this work reports a surfactant-controlled synthetic method to obtain a nanophase of mesoporous ceria-zirconia solid solution containing cationic defects in the crystalline structure. The incorporation of a cationic surfactant (myristyltrimethylammonium bromide) into the ceria-zirconia solid network not only controlled the pore diameter distribution but also induced creation of the lattice defect. Ceria-zirconia solid solution showed crystal microstrain and structural distortion that varied with the calcination temperature. Compared to pure ceria, the addition of zirconium to the ceria promoted the bulk oxygen reducibility and enhanced the thermal stability of the solid. Hydrogen could be stored into or released from the PdO/Ce{sub 0.6}Zr{sub 0.4}O{sub 2} catalyst during the TPR procedure, which is associated to the formation/decomposition of a PdH{sub x} phase, due to the hydrogen dissociation catalyzed by metallic Pd. At cool start of reaction, NO reduction by CO with excess oxygen over the Pd/Ce{sub 0.6}Zr{sub 0.4}O{sub 2} catalyst showed selectivity around 100% to N{sub 2}. A competition between NO reduction by CO and CO oxidation by O{sub 2} was observed: at reaction temperatures below 200 deg. C, NO inhibited CO oxidation activity; however, at reaction temperatures above 200 deg. C, high activity of CO oxidation resulted in an inhibition effect on NO reduction.

Morphology controlled Y{sub 2}O{sub 3}:Eu{sup 3+} nanophosphors with enhanced photoluminescence properties

Energy Technology Data Exchange (ETDEWEB)

Kumar, Deepak [School of Physics and Materials Science, Thapar University, Patiala 147003, Punjab (India); Sharma, Manoj, E-mail: manojnarad@sggswu.org [Department of Nanotechnology, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab (India); Pandey, O.P., E-mail: oppandey@thapar.edu [School of Physics and Materials Science, Thapar University, Patiala 147003, Punjab (India)

2015-02-15

Eu{sup 3+} doped Y{sub 2}O{sub 3} is prepared by a co-precipitation method using ammonium hydrogen carbonate as precipitating agent. In the present work we studied the effect of different molar concentrations of Poly vinyl pyrrolidone (PVP) and 1-Thio-glycerol (TG) as capping agents to enhance the optical and morphological properties of Y{sub 2}O{sub 3}:Eu{sup 3+} nanophosphors. In addition, variation of pH was studied to control the particle size of the synthesized product. The polymer concentration (TG and PVP) was also optimized at different pH to get higher luminescence of Eu{sup 3+} doped Y{sub 2}O{sub 3} nanoparticles (NPs). It was observed that pH of solution during synthesis and also its concentration affect the morphological and optical properties of Y{sub 2}O{sub 3}:Eu{sup 3+}. The structural, morphological and optical properties were studied by an X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy and photoluminescence spectroscopy. XRD studies followed by Rietveld refinement confirmed the body-centered cubic structure of doped nanophosphors. It was observed that at optimized pH and polymer concentration the nanoparticles of Y{sub 2}O{sub 3}:Eu{sup 3+} have narrow size distribution and exhibited enhanced photoluminescent properties. - highlights: • Nano-sized Y{sub 2}O{sub 3}:Eu{sup 3+} were synthesized by a co-precipitation method using PVP and TG as capping agents. • Effect of polymers (PVP and TG) on morphological properties of Y{sub 2}O{sub 3}:Eu{sup 3+} has been explained in detail. • Improvement in PL intensity for Y{sub 2}O{sub 3}:Eu{sup 3+} prepared with polymers has been explained in detail.

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.

The first quinary rare earth thiophosphates. Cs{sub 5}Ln{sub 3}X{sub 3}(P{sub 2}S{sub 6}){sub 2}(PS{sub 4}) (Ln = La, Ce, X = Br, Cl) and the quasi-quaternary Cs{sub 10}Y{sub 4}Cl{sub 10}(P{sub 2}S{sub 6}){sub 3}

Energy Technology Data Exchange (ETDEWEB)

Schoop, Leslie Mareike; Eger, Roland; Nuss, Juergen; Pielnhofer, Florian [Max Planck Institute for Solid State Research, Stuttgart (Germany); Lotsch, Bettina Valeska [Max Planck Institute for Solid State Research, Stuttgart (Germany); Nanosystems Initiative Munich (NIM) and Center for Nanoscience, Muenchen (Germany)

2017-12-13

We report the first examples of quinary rare earth thiophosphates with a fully ordered cation and anion distribution, Cs{sub 5}Ln{sub 3}X{sub 3}(P{sub 2}S{sub 6}){sub 2}(PS{sub 4}), (Ln = La, Ce and X = Br, Cl) as well as the quasi-quaternary Cs{sub 10}Y{sub 4}Cl{sub 10}(P{sub 2}S{sub 6}){sub 3}. These four new compounds crystallize in three different, unknown structure types. The yellowish, transparent, brittle Cs{sub 5}Ce{sub 3}Br{sub 3}(P{sub 2}S{sub 6}){sub 2}(PS{sub 4}) crystallizes in the orthorhombic space group Pnma (no. 62) with a = 13.276(3), b = 14.891(3), c = 19.593(4) Aa, and V = 3873(1) Aa{sup 3} in a novel structure type. Colorless crystals of Cs{sub 5}La{sub 3}Br{sub 3}(P{sub 2}S{sub 6}){sub 2}(PS{sub 4}) and Cs{sub 5}La{sub 3}Cl{sub 3}(P{sub 2}S{sub 6}){sub 2}(PS{sub 4}) are isotypic and were obtained in the monoclinic space group P2{sub 1}/m (no. 11) with a = 9.715(2), b = 14.310(3), c = 13.685(3) Aa, β = 100.16(3) and V = 1873(1) Aa{sup 3} and a = 9.513(2), b = 14.182(3), c = 13.699(3) Aa, β = 99.39(3) and V = 1823(1) Aa{sup 3}, respectively. Both structures contain isolated hexathiohypodiphosphate(IV) [P{sub 2}S{sub 6}]{sup 4-} and thiophosphate [PS{sub 4}]{sup 3-} units that are arranged alternately in layers. Cs{sub 10}Y{sub 4}Cl{sub 10}(P{sub 2}S{sub 6}){sub 3} crystallizes in colorless transparent platelets in the orthorhombic space group Pnnm (no. 58) with a = 13.153(3), b = 28.964(6), c = 7.780(2) Aa, and V = 2964(1) Aa{sup 3}. The structure is composed of isolated [P{sub 4/2}S{sub 6}]{sup 4-} octahedra containing four half occupied P positions surrounded octahedrally by sulfur. We show with Raman scattering that this disordered thiophosphate anion shows a Raman spectrum that is distinct from spectra published for other literature-known thiophosphate anions. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Effect of B{sub 2}O{sub 3}/P{sub 2}O{sub 5} substitution on the properties and structure of tin boro-phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Saitoh, Akira, E-mail: asaito@ehime-u.ac.jp [Graduate School of Science and Engineering, Ehime University, Matsuyama, 3 Bunkyo-cho (Japan); Tricot, Grégory [LASIR UMR-CNRS 8516, Université de Lille 1, Villeneuve d' Ascq 59655 (France); UCCS UMR-CNRS 8181, Université de Lille 1, Villeneuve d' Ascq 59655 (France); Rajbhandari, Prashant [UCCS UMR-CNRS 8181, Université de Lille 1, Villeneuve d' Ascq 59655 (France); Anan, Shoji; Takebe, Hiromichi [Graduate School of Science and Engineering, Ehime University, Matsuyama, 3 Bunkyo-cho (Japan)

2015-01-15

Effect of B{sub 2}O{sub 3}/P{sub 2}O{sub 5} substitution on the properties and structure of the ternary 67SnO–(33–x)P{sub 2}O{sub 5}–xB{sub 2}O{sub 3} composition line (from x = 0–33 mol%) are examined in this contribution. We show that density and glass transition temperature increase while molar volume and thermal expansion coefficient decrease with increasing B{sub 2}O{sub 3} concentration. Density and thermal properties experience an original three-domain evolution with rapid (region I: 0 ≤ x < 5), substantial (II: 5 < x ≤ 15), and moderate (III: 15 < x ≤ 33) increase. In order to explain this unconventional behaviour, the glass structure has been investigated using high magnetic field 1 dimensional {sup 31}P and {sup 11}B MAS–NMR, micro-Raman and infrared spectroscopies. {sup 11}B MAS–NMR experiments allow to (i) monitor the 3- and 4-fold coordinated borate species proportion and (ii) highlight the presence of unreported 4-fold coordinated species in the region (III). Finally, it is shown that substitution of P{sub 2}O{sub 5} by B{sub 2}O{sub 3} induces an alteration of the dimeric phosphate network and formation of mixed anion structure that consists of Q{sup 0} phosphate units, 3- and 4-fold coordinated borate units and their combinations. - Highlights: • We examined B{sub 2}O{sub 3}/P{sub 2}O{sub 5} substitution effect on the ternary SnO–P{sub 2}O{sub 5}–B{sub 2}O{sub 3} glasses. • We show a three-domains evolution for density and thermal properties. • The structure was investigated by {sup 31}P and {sup 11}B NMR, Raman and IR spectroscopies. • 3 and 4-folded borate species and unreported 4-folded species are revealed. • Mixed anion structure consists of Q{sup 0} phosphate unit and 3- and 4-folded borate units.

Controlling magnetic domain wall motion in the creep regime in He{sup +}-irradiated CoFeB/MgO films with perpendicular anisotropy

Energy Technology Data Exchange (ETDEWEB)

Herrera Diez, L., E-mail: liza.herrera-diez@ief.u-psud.fr; García-Sánchez, F.; Adam, J.-P.; Devolder, T.; Eimer, S.; El Hadri, M. S.; Ravelosona, D. [Institut d' Electronique Fondamentale, Université Paris-Sud, UMR CNRS 8622, 91405 Orsay (France); Lamperti, A.; Mantovan, R. [Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate (MB) (Italy); Ocker, B. [Singulus Technology AG, Hanauer Landstrasse 103, 63796 Kahl am Main (Germany)

2015-07-20

This study presents the effective tuning of perpendicular magnetic anisotropy in CoFeB/MgO thin films by He{sup +} ion irradiation and its effect on domain wall motion in a low field regime. Magnetic anisotropy and saturation magnetisation are found to decrease as a function of the irradiation dose which can be related to the observed irradiation-induced changes in stoichiometry at the CoFeB/MgO interface. These changes in the magnetic intrinsic properties of the film are reflected in the domain wall dynamics at low magnetic fields (H) where irradiation is found to induce a significant decrease in domain wall velocity (v). For all irradiation doses, domain wall velocities at low fields are well described by a creep law, where Ln(v) vs. H{sup −1∕4} behaves linearly, up to a maximum field H*, which has been considered as an approximation to the value of the depinning field H{sub dep}. In turn, H* ≈ H{sub dep} is seen to increase as a function of the irradiation dose, indicating an irradiation-induced extension of the creep regime of domain wall motion.

Identity-specific motivation: How distinct identities direct self-regulation across distinct situations.

Science.gov (United States)

Browman, Alexander S; Destin, Mesmin; Molden, Daniel C

2017-12-01

Research on self-regulation has traditionally emphasized that people's thoughts and actions are guided by either (a) domain-general motivations that emerge from a cumulative history of life experiences, or (b) situation-specific motivations that emerge in immediate response to the incentives present in a particular context. However, more recent studies have illustrated the importance of understanding the interplay between such domain-general and situation-specific motivations across the types of contexts people regularly encounter. The present research, therefore, expands existing perspectives on self-regulation by investigating how people's identities -the internalized roles, relationships, and social group memberships that define who they are-systemically guide when and how different domain-general motivations are activated within specific types of situations. Using the motivational framework described by regulatory focus theory (Higgins, 1997), Studies 1 and 2 demonstrate that people indeed have distinct, identity-specific motivations that uniquely influence their current self-regulation when such identities are active. Studies 3-5 then begin to explore how identity-specific motivations are situated within people's larger self-concept. Studies 3a and 3b demonstrate that the less compatible people's specific identities, the more distinct are the motivations connected to those identities. Studies 4-5 then provide some initial, suggestive evidence that identity-specific motivations are not a separate, superordinate feature of people's identities that then alter how they pursue any subordinate, identity-relevant traits, but instead that such motivations emerge from the cumulative motivational significance of the subordinate traits to which the identities themselves become attached. Implications for understanding the role of the self-concept in self-regulation are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Inter-domain cross-talk controls the NifA protein activity of Herbaspirillum seropedicae.

Science.gov (United States)

Monteiro, R A; de Souza, E M; Wassem, R; Yates, M G; Pedrosa, F O; Chubatsu, L S

2001-11-09

Herbaspirillum seropedicae is an endophytic diazotroph, which colonizes sugar cane, wheat, rice and maize. The activity of NifA, a transcriptional activator of nif genes in H. seropedicae, is controlled by ammonium ions through a mechanism involving its N-terminal domain. Here we show that this domain interacts specifically in vitro with the N-truncated NifA protein, as revealed by protection against proteolysis, and this interaction caused an inhibitory effect on both the ATPase and DNA-binding activities of the N-truncated NifA protein. We suggest that the N-terminal domain inhibits NifA-dependent transcriptional activation by an inter-domain cross-talk between the catalytic domain of the NifA protein and its regulatory N-terminal domain in response to fixed nitrogen.

Control beliefs and health locus of control in Ugandan, German and migrated sub-Saharan African HIV infected individuals.

Science.gov (United States)

Milz, Ruth U; Husstedt, Ingo-W; Reichelt, Doris; Evers, Stefan

2016-04-01

Little is known about the influence of control beliefs on antiretroviral drug adherence in patients who migrated from sub-Saharan Africa to Europe. The aim of this study was to explore the differences in health locus of control and control beliefs between HIV infected patients from sub-Saharan Africa with and without a lifetime experience of migration. A sample of 62 HIV infected consecutive patients referred to the HIV clinics at the University Hospital of Münster (Germany) and at the Rubaga Hospital Kampala (Uganda) were enrolled into this study. We compared three groups of patients: sub-Saharan African migrants, German patients, and local Ugandan patients. We used the German health and illness related control beliefs questionnaire (KKG), the Competence and control beliefs questionnaire (FKK), and the Powe Fatalism Inventory-HIV/AIDS-Version (PFI-HIV/AIDS-Version) and translated these scales into English and Luganda. In addition, the patients' sociodemographic, acculturation, clinical, and immunological data were registered. Significant results were shown in HIV related external locus of control between migrated sub-Saharan African and local Ugandan patients compared to German patients. General control beliefs showed no significant differences. In the PFI-HIV-Version, there was a significant difference between migrated sub-Saharan African and Ugandan patients compared to German patients. Our data suggest that the experience of migration does not influence the locus of control. Compared to German HIV patients, African patients in general showed a significantly higher external health locus of control which might have implications for drug adherence. Copyright © 2016 Elsevier Inc. All rights reserved.

Thickness and bilayer number dependence on exchange bias in ferromagnetic/antiferromagnetic multilayers based on La{sub 1−x}Ca{sub x}MnO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Restrepo-Parra, E., E-mail: erestrepopa@unal.edu.co [Departamento de Física y Química, Universidad Nacional de Colombia-Sede Manizales, A.A. 127 Manizales (Colombia); Agudelo-Giraldo, J.D. [Departamento de Física y Química, Universidad Nacional de Colombia-Sede Manizales, A.A. 127 Manizales (Colombia); Grupo de Investigación y Desarrollo en Informática y Telecomunicaciones, Universidad de Manizales, Manizales (Colombia); Restrepo, J. [Grupo de Magnetismo y Simulación, Instituto de Física, Universidad de Antioquia, A.A. 1226 Medellín (Colombia)

2014-05-01

In this work, simulations of ferromagnetic/antiferromagnetic multilayers of La{sub 1−x}Ca{sub x}MnO{sub 3} have been carried out by using the Monte Carlo method combined with the Metropolis algorithm and the classical Heisenberg model. In the Hamiltonian we have considered three contributions: nearest neighbor exchange interaction, magnetocrystalline anisotropy and Zeeman interaction. Samples were built by including three types of Mn ions depending on their valence state and type of ionic orbital. Both the number of layers and the antiferromagnetic layer thickness influence on the exchange bias phenomenon are analyzed. Hysteresis loops results exhibit not only a shift as evidence of exchange bias but also the formation of plateaus or steps caused by the presence of more than one interface and the low layers thickness. Each layer presents a strong magnetic behavior because the magneto static energy favors formation of multi-domains in contrast with the single-domains of a single layer FM producing one sub-Loop of each domain (each layer). On the other hand, as the number of layers (n) increases, the sub-cycles tend to disappear. As the plateaus disappear, the system is more effective, increasing the coercive and bias fields. Moreover, domain sizes (layers thickness) also affect the shape of the hysteresis loop. On increasing the thickness of the AFM layer, a decrease in the plateaus produced by the uncoupling is generated.

Absorption and fluorescence spectroscopic characterization of BLUF domain of AppA from Rhodobacter sphaeroides

Energy Technology Data Exchange (ETDEWEB)

Zirak, P. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetstrasse 31, D-93053 Regensburg (Germany); Penzkofer, A. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetstrasse 31, D-93053 Regensburg (Germany)], E-mail: alfons.penzkofer@physik.uni-regensburg.de; Schiereis, T. [Institut fuer Biologie, Experimentelle Biophysik, Humboldt-Universitaet zu Berlin, Invalidenstrasse 42, D-10115 Berlin (Germany); Hegemann, P. [Institut fuer Biologie, Experimentelle Biophysik, Humboldt-Universitaet zu Berlin, Invalidenstrasse 42, D-10115 Berlin (Germany); Jung, A. [Max-Planck-Institut fuer medizinische Forschung, Abteilung Biomolekulare Mechanismen, Jahnstrasse 29, D-69120 Heidelberg (Germany); Schlichting, I. [Max-Planck-Institut fuer medizinische Forschung, Abteilung Biomolekulare Mechanismen, Jahnstrasse 29, D-69120 Heidelberg (Germany)

2005-08-08

The BLUF domain of the transcriptional anti-repressor protein AppA from the non-sulfur anoxyphototrophic purple bacterium Rhodobacter sphaeroides was characterized by absorption and emission spectroscopy. The BLUF domain constructs AppA{sub 148} (consisting of amino-acid residues 1-148) and AppA{sub 126} (amino-acid residues 1-126) are investigated. The cofactor of the investigated domains is found to consist of a mixture of the flavins riboflavin, FMN, and FAD. The dark-adapted domains exist in two different active receptor conformations (receptor states) with different sub-nanosecond fluorescence lifetimes (BLUF{sub r,f} and BLUF{sub r,sl}) and a small non-interacting conformation (BLUF{sub nc}). The active receptor conformations are transformed to putative signalling states (BLUF{sub s,f} and BLUF{sub s,sl}) of low fluorescence efficiency and picosecond fluorescence lifetime by blue-light excitation (light-adapted domains). In the dark at room temperature both signalling states recover back to the initial receptor states with a time constant of about 17 min. A quantum yield of signalling state formation of about 25% was determined by intensity dependent transmission measurements. A photo-cycle scheme is presented including photo-induced charge transfer complex formation, charge recombination, and protein binding pocket reorganisation.

A shallow subsurface controlled release facility in Bozeman, Montana, USA, for testing near surface CO<sub>2sub> detection techniques and transport models

Energy Technology Data Exchange (ETDEWEB)

Spangler, Lee H. [Montana State Univ., Bozeman, MT (United States). Dept. of Chemistry and Biochemistry; Dobeck, Laura M. [Montana State Univ., Bozeman, MT (United States). Dept. of Chemistry and Biochemistry; Repasky, Kevin S. [Montana State Univ., Bozeman, MT (United States). Dept. of Electrical and Computer Engineering; Nehrir, Amin R. [Montana State Univ., Bozeman, MT (United States). Dept. of Electrical and Computer Engineering; Humphries, Seth D. [Montana State Univ., Bozeman, MT (United States). Dept. of Electrical and Computer Engineering; Barr, Jamie L. [Montana State Univ., Bozeman, MT (United States). Dept. of Electrical and Computer Engineering; Keith, Charlie J. [Montana State Univ., Bozeman, MT (United States). Dept. of Electrical and Computer Engineering; Shaw, Joseph A. [Montana State Univ., Bozeman, MT (United States). Dept. of Electrical and Computer Engineering; Rouse, Joshua H. [Montana State Univ., Bozeman, MT (United States). Dept. of Electrical and Computer Engineering; Cunningham, Alfred B. [Montana State Univ., Bozeman, MT (United States). Dept. of Civil Engineering; Benson, Sally M. [Stanford Univ., CA (United States). Global Climate and Energy Project; Oldenburg, Curtis M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Lewicki, Jennifer L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Wells, Arthur W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Diehl, J. Rodney [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Strazisar, Brian R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Fessenden, Julianna E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Div. of Earth and Environmental Sciences; Rahn, Thom A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Div. of Earth and Environmental Sciences; Amonette, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Barr, Jon L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pickles, William L. [Univ. of California, Santa Cruz, CA (United States). Earth and Planetary Sciences; Jacobson, James D. [Univ. of California, Santa Cruz, CA (United States). Earth and Planetary Sciences; Silver, Eli A. [Univ. of California, Santa Cruz, CA (United States). Earth and Planetary Sciences; Male, Erin J. [Univ. of California, Santa Cruz, CA (United States). Earth and Planetary Sciences; Rauch, Henry W. [Univ. of West Virginia, Morgantown, WV (United States). Dept. of Geology and Geography; Gullickson, Kadie S. [Montana State Univ., Bozeman, MT (United States). Dept. of Chemistry and Biochemistry; Trautz, Robert [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Kharaka, Yousif [U.S. Geological Survey, Menlo Park, CA (United States); Birkholzer, Jens [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Wielopolski, Lucien [Brookhaven National Lab. (BNL), Upton, NY (United States)

2010-03-01

A controlled field pilot has been developed in Bozeman, Montana, USA, to study near surface CO<sub>2sub> transport and detection technologies. A slotted horizontal well divided into six zones was installed in the shallow subsurface. The scale and CO<sub>2sub> release rates were chosen to be relevant to developing monitoring strategies for geological carbon storage. The field site was characterized before injection, and CO<sub>2sub> transport and concentrations in saturated soil and the vadose zone were modeled. Controlled releases of CO<sub>2sub> from the horizontal well were performed in the summers of 2007 and 2008, and collaborators from six national labs, three universities, and the U. S. Geological Survey investigated movement of CO<sub>2sub> through the soil, water, plants, and air with a wide range of near surface detection techniques. An overview of these results will be presented.

Structure of a mouse immunoglobulin G that lacks the entire C sub H 1 domain: Protein sequencing and small-angle X-ray scattering studies

Energy Technology Data Exchange (ETDEWEB)

Igarashi, Takako; Tanaka, Toshiyuki; Nakanishi, Mamoru; Arata, Yoji (Univ. of Tokyo (Japan)); Sato, Mamoru; Katsube, Yukiteru (Osaka Univ. (Japan)); Takio, Koji (Institute of Physical and Chemical Research, Saitama (Japan))

1990-06-19

The structure of a short-chain IgG2a antibody, which is a member of the family of mouse anti-dansyl switch variant antibodies with identical variable regions but different heavy-chain constant regions, is reported. Amino acid sequencing analyses have demonstrated that in the short-chain IgG2a antibody the entire C{sub H}1 domain is deleted whereas the hinge region remains intact. Small-angle X-ray scattering data were collected for the short-chain IgG2a antibody and compared with those for the switch variant IgG1, IgG2a, and IgG2b antibodies with the normal heavy chain. It has been concluded that deletion of the C{sub H}1 domain results in a large structural change and the short-chain IgG2a antibody possesses an elongated molecular shape with a much smaller hinge angle as compared with the normal IgG2a antibody that is a Y-shaped molecule.

Correlations between critical current density, j{sub c}, critical temperature, T{sub c}, and structural quality of Y{sub 1}B{sub 2}Cu{sub 3}O{sub 7-x} thin superconducting films

Energy Technology Data Exchange (ETDEWEB)

Chrzanowski, J.; Xing, W.B.; Atlan, D. [Simon Fraser Univ., British Columbia (Canada)] [and others

1994-12-31

Correlations between critical current density (j{sub c}) critical temperature (T{sub c}) and the density of edge dislocations and nonuniform strain have been observed in YBCO thin films deposited by pulsed laser ablation on (001) LaAlO{sub 3} single crystals. Distinct maxima in j{sub c} as a function of the linewidths of the (00{ell}) Bragg reflections and as a function of the mosaic spread have been found in the epitaxial films. These maxima in j{sub c} indicate that the magnetic flux lines, in films of structural quality approaching that of single crystals, are insufficiently pinned which results in a decreased critical current density. T{sub c} increased monotonically with improving crystalline quality and approached a value characteristic of a pure single crystal. A strong correlation between j{sub c} and the density of edge dislocations N{sub D} was found. At the maximum of the critical current density the density of edge dislocations was estimated to be N{sub D}{approximately}1-2 x 10{sup 9}/cm{sup 2}.

Two distinct voltage-sensing domains control voltage sensitivity and kinetics of current activation in CaV1.1 calcium channels.

Science.gov (United States)

Tuluc, Petronel; Benedetti, Bruno; Coste de Bagneaux, Pierre; Grabner, Manfred; Flucher, Bernhard E

2016-06-01

Alternative splicing of the skeletal muscle CaV1.1 voltage-gated calcium channel gives rise to two channel variants with very different gating properties. The currents of both channels activate slowly; however, insertion of exon 29 in the adult splice variant CaV1.1a causes an ∼30-mV right shift in the voltage dependence of activation. Existing evidence suggests that the S3-S4 linker in repeat IV (containing exon 29) regulates voltage sensitivity in this voltage-sensing domain (VSD) by modulating interactions between the adjacent transmembrane segments IVS3 and IVS4. However, activation kinetics are thought to be determined by corresponding structures in repeat I. Here, we use patch-clamp analysis of dysgenic (CaV1.1 null) myotubes reconstituted with CaV1.1 mutants and chimeras to identify the specific roles of these regions in regulating channel gating properties. Using site-directed mutagenesis, we demonstrate that the structure and/or hydrophobicity of the IVS3-S4 linker is critical for regulating voltage sensitivity in the IV VSD, but by itself cannot modulate voltage sensitivity in the I VSD. Swapping sequence domains between the I and the IV VSDs reveals that IVS4 plus the IVS3-S4 linker is sufficient to confer CaV1.1a-like voltage dependence to the I VSD and that the IS3-S4 linker plus IS4 is sufficient to transfer CaV1.1e-like voltage dependence to the IV VSD. Any mismatch of transmembrane helices S3 and S4 from the I and IV VSDs causes a right shift of voltage sensitivity, indicating that regulation of voltage sensitivity by the IVS3-S4 linker requires specific interaction of IVS4 with its corresponding IVS3 segment. In contrast, slow current kinetics are perturbed by any heterologous sequences inserted into the I VSD and cannot be transferred by moving VSD I sequences to VSD IV. Thus, CaV1.1 calcium channels are organized in a modular manner, and control of voltage sensitivity and activation kinetics is accomplished by specific molecular mechanisms

The disordering phase transformation in (Ni/sub 70/Fe/sub 30/)/sub 3/(V/sub 98-x/Al/sub x/Ti/sub 2/) alloys with O ≤ x ≤ 80

International Nuclear Information System (INIS)

Das Gupta, A.; Horton, J.A.

1985-01-01

The sequence of disordering transformation processes in the A/sub 3/B type alloy series (Ni/sub 70/Fe/sub 30/)/sub 3/(V/sub 98-x/Al/sub x/Ti/sub 2/), currently under development for high-temperature structural applications, was studied by differential scanning calorimetry (DSC), x-ray diffraction, optical microscopy, and transmission electron microscopy (TEM). Results of DSC show that in all alloys there are two endothermic stages of phase transformation from the ordered to the disordered state. With increasing chi, the disordering transition temperature, T/sub c/, reaches a maximum --1000 0 C at chi ≅ 50 and then decreases. Interrupted heating, followed by water quenching, was used to characterize the crystal structure and the microstructure of the intermediate phases. For the x = 20 alloy, TEM observations showed ordered regions of DO/sub 22/ phase in a matrix of disordered fcc (Al) phase at intermediate temperatures. The ordered domains transformed morphologically into cuboid like regions at higher temperatures. From a combined study by all the techniques, the authors conclude that in alloy with x between 0 and 20, the sequence of phase transformations from heating is: DO/sub 2/ → DO/sub 22/ + Al → Al, whereas in alloys with x > 40, the major sequence is Ll/sub 2/ + B/sub 2/ → Ll/sub 2/ + Al → Al

Image-Based Modeling Reveals Dynamic Redistribution of DNA Damageinto Nuclear Sub-Domains

Energy Technology Data Exchange (ETDEWEB)

Costes Sylvain V., Ponomarev Artem, Chen James L.; Nguyen, David; Cucinotta, Francis A.; Barcellos-Hoff, Mary Helen

2007-08-03

Several proteins involved in the response to DNA doublestrand breaks (DSB) f orm microscopically visible nuclear domains, orfoci, after exposure to ionizing radiation. Radiation-induced foci (RIF)are believed to be located where DNA damage occurs. To test thisassumption, we analyzed the spatial distribution of 53BP1, phosphorylatedATM, and gammaH2AX RIF in cells irradiated with high linear energytransfer (LET) radiation and low LET. Since energy is randomly depositedalong high-LET particle paths, RIF along these paths should also berandomly distributed. The probability to induce DSB can be derived fromDNA fragment data measured experimentally by pulsed-field gelelectrophoresis. We used this probability in Monte Carlo simulations topredict DSB locations in synthetic nuclei geometrically described by acomplete set of human chromosomes, taking into account microscope opticsfrom real experiments. As expected, simulations produced DNA-weightedrandom (Poisson) distributions. In contrast, the distributions of RIFobtained as early as 5 min after exposure to high LET (1 GeV/amu Fe) werenon-random. This deviation from the expected DNA-weighted random patterncan be further characterized by "relative DNA image measurements." Thisnovel imaging approach shows that RIF were located preferentially at theinterface between high and low DNA density regions, and were morefrequent than predicted in regions with lower DNA density. The samepreferential nuclear location was also measured for RIF induced by 1 Gyof low-LET radiation. This deviation from random behavior was evidentonly 5 min after irradiation for phosphorylated ATM RIF, while gammaH2AXand 53BP1 RIF showed pronounced deviations up to 30 min after exposure.These data suggest that DNA damage induced foci are restricted to certainregions of the nucleus of human epithelial cells. It is possible that DNAlesions are collected in these nuclear sub-domains for more efficientrepair.

Magnetic contribution of Bi{sub 0.85}La{sub 0.15}FeO{sub 3} in (1−x)Bi{sub 0.85}La{sub 0.15}FeO{sub 3}–(x)CoFe{sub 2}O{sub 4} nanocomposite powders

Energy Technology Data Exchange (ETDEWEB)

Han, Ru-shuai; Qi, Li-qian; Hou, Xue; Liu, Li-hu; Liu, Hui-yuan [College of Physics Science & Information Engineering, Hebei Normal University, Shijiazhuang 050024 (China); Key Laboratory of Advanced Films of Hebei Province, Shijiazhuang, Hebei 050024 (China); Xian, Xiao-Ning [Department of Information technology, Yuncheng Agricultural College, Shanxi 044000 (China); Guo, Ge-Xin [College of Physics Science & Information Engineering, Hebei Normal University, Shijiazhuang 050024 (China); Key Laboratory of Advanced Films of Hebei Province, Shijiazhuang, Hebei 050024 (China); Sun, Hui-yuan, E-mail: huiyuansun@126.com [College of Physics Science & Information Engineering, Hebei Normal University, Shijiazhuang 050024 (China); Key Laboratory of Advanced Films of Hebei Province, Shijiazhuang, Hebei 050024 (China)

2016-12-15

In this work, a solid phase reaction method was used to fabricate (1−x)Bi{sub 0.85}La{sub 0.15}FeO{sub 3}–xCoFe{sub 2}O{sub 4} (x=0.1, 0.2, 0.3, 0.4) composite powders. X-ray diffraction patterns showed that no chemical reaction occurred between the separate Bi{sub 0.85}La{sub 0.15}FeO{sub 3} and CoFe{sub 2}O{sub 4} phases and indicated that the powder samples had two distinct phases with a CoFe{sub 2}O{sub 4} spinel phase and a Bi{sub 0.85}La{sub 0.15}FeO{sub 3} perovskite phase. The average crystallite sizes of the Bi{sub 0.85}La{sub 0.15}FeO{sub 3} in the composite powder were almost unchanged as the CoFe{sub 2}O{sub 4} content was increased. By comparing the experimental and theoretical values for the magnetization, we found that the Bi{sub 0.85}La{sub 0.15}FeO{sub 3} phase contributed to the magnetization of the composite powders. In addition, it also provides a new way to prove the existence of magnetoelectric coupling in the sample. - Highlights: • Theoretical magnetic value of the samples was calculated. • The experimental value of the magnetism was greater than the theoretical value. • The effect of the crystallite sizes on the magnetism was eliminated by calculating the crystallite sizes of BLFO. • The BLFO contributed to the magnetic moment through the magnetoelectric coupling.

Cortical mechanisms of cognitive control for shifting attention in vision and working memory.

Science.gov (United States)

Tamber-Rosenau, Benjamin J; Esterman, Michael; Chiu, Yu-Chin; Yantis, Steven

2011-10-01

Organisms operate within both a perceptual domain of objects and events, and a mnemonic domain of past experiences and future goals. Each domain requires a deliberate selection of task-relevant information, through deployments of external (perceptual) and internal (mnemonic) attention, respectively. Little is known about the control of attention shifts in working memory, or whether voluntary control of attention in these two domains is subserved by a common or by distinct functional networks. We used human fMRI to examine the neural basis of cognitive control while participants shifted attention in vision and in working memory. We found that these acts of control recruit in common a subset of the dorsal fronto-parietal attentional control network, including the medial superior parietal lobule, intraparietal sulcus, and superior frontal sulcus/gyrus. Event-related multivoxel pattern classification reveals, however, that these regions exhibit distinct spatio-temporal patterns of neural activity during internal and external shifts of attention, respectively. These findings constrain theoretical accounts of selection in working memory and perception by showing that populations of neurons in dorsal fronto-parietal network regions exhibit selective tuning for acts of cognitive control in different cognitive domains.

Multifunctional BiFeO{sub 3}/TiO{sub 2} nano-heterostructure: Photo-ferroelectricity, rectifying transport, and nonvolatile resistive switching property

Energy Technology Data Exchange (ETDEWEB)

Sarkar, Ayan; Khan, Gobinda Gopal, E-mail: gobinda.gk@gmail.com [Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, Technology Campus, Block JD2, Sector III, Salt Lake City, Kolkata 700 098 (India); Chaudhuri, Arka [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake City, Kolkata 700 098 (India); Department of Applied Science, Haldia Institute of Technology, Haldia 721657, Purba Medinipur, West Bengal (India); Das, Avishek [Department of Electronic Science, University of Calcutta, 92 APC Road, Kolkata 700009 (India); Mandal, Kalyan [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake City, Kolkata 700 098 (India)

2016-01-18

Multifunctional BiFeO{sub 3} nanostructure anchored TiO{sub 2} nanotubes are fabricated by coupling wet chemical and electrochemical routes. BiFeO{sub 3}/TiO{sub 2} nano-heterostructure exhibits white-light-induced ferroelectricity at room temperature. Studies reveal that the photogenerated electrons trapped at the domain/grain boundaries tune the ferroelectric polarization in BiFeO{sub 3} nanostructures. The photon controlled saturation and remnant polarization opens up the possibility to design ferroelectric devices based on BiFeO{sub 3.} The nano-heterostructure also exhibits substantial photovoltaic effect and rectifying characteristics. Photovoltaic property is found to be correlated with the ferroelectric polarization. Furthermore, the nonvolatile resistive switching in BiFeO{sub 3}/TiO{sub 2} nano-heterostructure has been studied, which demonstrates that the observed resistive switching is most likely caused by the electric-field-induced carrier injection/migration and trapping/detrapping process at the hetero-interfaces. Therefore, BiFeO{sub 3}/TiO{sub 2} nano-heterostructure coupled with logic, photovoltaics and memory characteristics holds promises for long-term technological applications in nanoelectronics devices.

ATRX ADD domain links an atypical histone methylation recognition mechanism to human mental-retardation syndrome

Energy Technology Data Exchange (ETDEWEB)

Iwase, Shigeki; Xiang, Bin; Ghosh, Sharmistha; Ren, Ting; Lewis, Peter W.; Cochrane, Jesse C.; Allis, C. David; Picketts, David J.; Patel, Dinshaw J.; Li, Haitao; Shi, Yang (Harvard-Med); (Ottawa Hosp.); (MSKCC); (Rockefeller); (CH-Boston); (Tsinghua); (Mass. Gen. Hosp.)

2011-07-19

ATR-X (alpha-thalassemia/mental retardation, X-linked) syndrome is a human congenital disorder that causes severe intellectual disabilities. Mutations in the ATRX gene, which encodes an ATP-dependent chromatin-remodeler, are responsible for the syndrome. Approximately 50% of the missense mutations in affected persons are clustered in a cysteine-rich domain termed ADD (ATRX-DNMT3-DNMT3L, ADD{sub ATRX}), whose function has remained elusive. Here we identify ADD{sub ATRX} as a previously unknown histone H3-binding module, whose binding is promoted by lysine 9 trimethylation (H3K9me3) but inhibited by lysine 4 trimethylation (H3K4me3). The cocrystal structure of ADD{sub ATRX} bound to H3{sub 1-15}K9me3 peptide reveals an atypical composite H3K9me3-binding pocket, which is distinct from the conventional trimethyllysine-binding aromatic cage. Notably, H3K9me3-pocket mutants and ATR-X syndrome mutants are defective in both H3K9me3 binding and localization at pericentromeric heterochromatin; thus, we have discovered a unique histone-recognition mechanism underlying the ATR-X etiology.

ATRX ADD Domain Links an Atypical Histone Methylation Recognition Mechanism to Human Mental-Retardation Syndrome

Energy Technology Data Exchange (ETDEWEB)

S Iwase; B Xiang; S Ghosh; T Ren; P Lewis; J Cochrane; C Allis; D Picketts; D Patel; et al.

2011-12-31

ATR-X (alpha-thalassemia/mental retardation, X-linked) syndrome is a human congenital disorder that causes severe intellectual disabilities. Mutations in the ATRX gene, which encodes an ATP-dependent chromatin-remodeler, are responsible for the syndrome. Approximately 50% of the missense mutations in affected persons are clustered in a cysteine-rich domain termed ADD (ATRX-DNMT3-DNMT3L, ADD{sub ATRX}), whose function has remained elusive. Here we identify ADD{sub ATRX} as a previously unknown histone H3-binding module, whose binding is promoted by lysine 9 trimethylation (H3K9me3) but inhibited by lysine 4 trimethylation (H3K4me3). The cocrystal structure of ADD{sub ATRX} bound to H3{sub 1-15}K9me3 peptide reveals an atypical composite H3K9me3-binding pocket, which is distinct from the conventional trimethyllysine-binding aromatic cage. Notably, H3K9me3-pocket mutants and ATR-X syndrome mutants are defective in both H3K9me3 binding and localization at pericentromeric heterochromatin; thus, we have discovered a unique histone-recognition mechanism underlying the ATR-X etiology.

TRANSIENT ANOMALOUS SUB-DIFFUSION ON BOUNDED DOMAINS

OpenAIRE

MEERSCHAERT, MARK M.; NANE, ERKAN; VELLAISAMY, P.

2012-01-01

This paper develops strong solutions and stochastic solutions for the tempered fractional diffusion equation on bounded domains. First the eigenvalue problem for tempered fractional derivatives is solved. Then a separation of variables, and eigenfunction expansions in time and space, are used to write strong solutions. Finally, stochastic solutions are written in terms of an inverse subordinator.

Thermochromic effect at room temperature of Sm{sub 0.5}Ca{sub 0.5}MnO{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Boileau, A.; Capon, F.; Barrat, S.; Pierson, J. F. [Universite de Lorraine, Institut Jean Lamour, Departement CP2S, UMR CNRS 7198, Nancy, F-54042 (France); Laffez, P. [Groupe de Recherche Electronique, Materiaux, Acoustique, Nanoscience (GREMAN), Universite Francois Rabelais de Tours, UMR CNRS 7347, IUT de Blois, 15 rue de la Chocolaterie, Blois, F-41000 (France)

2012-06-01

Sm{sub 0.5}Ca{sub 0.5}MnO{sub 3} thermochromic thin films were synthesized using dc reactive magnetron co-sputtering and subsequent annealing in air. The film structure was studied by x-ray diffraction analysis. To validate the thermochromic potentiality of Sm{sub 0.5}Ca{sub 0.5}MnO{sub 3}, electrical resistivity and infrared transmittance spectra were recorded for temperatures ranging from 77 K to 420 K. The temperature dependence of the optical band gap was estimated in the near infrared range. Upon heating, the optical transmission decreases in the infrared domain showing a thermochromic effect over a wide wavelength range at room temperature.

Controlling the switching field in nanomagnets by means of domain-engineered antiferromagnets

Science.gov (United States)

Folven, E.; Linder, J.; Gomonay, O. V.; Scholl, A.; Doran, A.; Young, A. T.; Retterer, S. T.; Malik, V. K.; Tybell, T.; Takamura, Y.; Grepstad, J. K.

2015-09-01

Using soft x-ray spectromicroscopy, we investigate the magnetic domain structure in embedded nanomagnets defined in L a0.7S r0.3Mn O3 thin films and LaFe O3/L a0.7S r0.3Mn O3 bilayers. We find that shape-controlled antiferromagnetic domain states give rise to a significant reduction of the switching field of the rectangular nanomagnets. This is discussed within the framework of competition between an intrinsic spin-flop coupling and shape anisotropy. The data demonstrates that shape effects in antiferromagnets may be used to control the magnetic properties in nanomagnets.

A simplified approach to control system specification and design using domain modelling and mapping

International Nuclear Information System (INIS)

Ludgate, G.A.

1992-01-01

Recent developments in the field of accelerator-domain and computer-domain modelling have led to a better understanding of the 'art' of control system specification and design. It now appears possible to 'compile' a control system specification to produce the architectural design. The information required by the 'compiler' is discussed and one hardware optimization algorithm presented. The desired characteristics of the hardware and software components of a distributed control system architecture are discussed and the shortcomings of some commercial products. (author)

Short range charge/orbital ordering in La{sub 1-x}Sr{sub x}Mn{sub 1-z}B{sub z}O{sub 3} (B Cu,Zn) manganites

Energy Technology Data Exchange (ETDEWEB)

Popovic, Z V [Materials Science Institute, University of Valencia, PO Box 22085, 46071 Valencia (Spain); Cantarero, A [Materials Science Institute, University of Valencia, PO Box 22085, 46071 Valencia (Spain); Thijssen, W H A [Materials Science Institute, University of Valencia, PO Box 22085, 46071 Valencia (Spain); Paunovic, N [Centre for Solid State Physics and New Materials, Institute of Physics, PO Box 68, 11080 Belgrade/Zemun (Serbia and Montenegro); Dohcevic-Mitrovic, Z [Centre for Solid State Physics and New Materials, Institute of Physics, PO Box 68, 11080 Belgrade/Zemun (Serbia and Montenegro); Sapina, F [Materials Science Institute, University of Valencia, PO Box 22085, 46071 Valencia (Spain)

2005-01-19

We have measured the reflectivity spectra of La{sub 1-x}Sr{sub x}Mn{sub 1-z}B{sub z}O{sub 3} (B = Cu, Zn; 0.17 {<=} x {<=} 0.30; 0 {<=} z {<=} 0.10) manganites over wide frequency (100-4000 cm{sup -1}) and temperature (80-300 K) ranges. Besides the previously observed infrared active modes or mode pairs at about 160 cm{sup -1} (external mode), 350 cm{sup -1} (bond bending mode) and 590 cm{sup -1} (bond stretching mode), we have clearly observed two additional phonon modes at about 645 and 720 cm{sup -1} below the temperature T{sub 1} (T{sub 1}sub C}), which coincides with the phase transition temperature when the system transforms from ferromagnetic metallic into a ferromagnetic insulator state. This transition is related to the formation of short range charge/orbitally ordered domains. The temperature T{sub 1} of the phase transition is dependent on the doping concentration and for optimally doped samples we have found that T{sub 1} {approx}(0.93 {+-} 0.02) T{sub C}. Electrical resistivity and magnetization measurements versus temperature and magnetic field support the short range charge/orbital ordering scenario.

A roadmap to control penguin effects in B{sub d}{sup 0}→J/ψK{sub S}{sup 0} and B{sub s}{sup 0}→J/ψϕ

Energy Technology Data Exchange (ETDEWEB)

Bruyn, Kristof De [Nikhef,Science Park 105, NL-1098 XG Amsterdam (Netherlands); Fleischer, Robert [Nikhef,Science Park 105, NL-1098 XG Amsterdam (Netherlands); Department of Physics and Astronomy, Vrije Universiteit Amsterdam,De Boelelaan 1081, NL-1081 HV Amsterdam (Netherlands)

2015-03-26

Measurements of CP violation in B{sub d}{sup 0}→J/ψK{sub S}{sup 0} and B{sub s}{sup 0}→J/ψϕ decays play key roles in testing the quark-flavour sector of the Standard Model. The theoretical interpretation of the corresponding observables is limited by uncertainties from doubly Cabibbo-suppressed penguin topologies. With continuously increasing experimental precision, it is mandatory to get a handle on these contributions, which cannot be calculated reliably in QCD. In the case of the measurement of sin 2β from B{sub d}{sup 0}→J/ψK{sub S}{sup 0}, the U-spin-related decay B{sub s}{sup 0}→J/ψK{sub S}{sup 0} offers a tool to control the penguin effects. As the required measurements are not yet available, we use data for decays with similar dynamics and the SU(3) flavour symmetry to constrain the size of the expected penguin corrections. We predict the CP asymmetries of B{sub s}{sup 0}→J/ψK{sub S}{sup 0} and present a scenario to fully exploit the physics potential of this decay, emphasising also the determination of hadronic parameters and their comparison with theory. In the case of the benchmark mode B{sub s}{sup 0}→J/ψϕ used to determine the B{sub s}{sup 0}-B-bar{sub s}{sup 0} mixing phase ϕ{sub s} the penguin effects can be controlled through B{sub d}{sup 0}→J/ψρ{sup 0} and B{sub s}{sup 0}→J/ψ ( K)-bar {sup ∗0} decays. The LHCb collaboration has recently presented pioneering results on this topic. We analyse their implications and present a roadmap for controlling the penguin effects.

Upgradation in SCADA and PLC of existing LN{sub 2} control system for SST-1

Energy Technology Data Exchange (ETDEWEB)

Panchal, Pradip, E-mail: pradip@ipr.res.in; Mahesuria, Gaurang; Panchal, Rohit; Patel, Rakesh; Sonara, Dashrath; Pitroda, Dipen; Nimavat, Hiren; Tanna, Vipul; Pradhan, Subrata

2016-11-15

Highlights: • The control system of LN{sub 2} Management System of SST-1 is designed on PLC and SCADA. • The implementation and results of up-gradation in PLC and SCADA are reported. • The up-gradation in PLC and SCADA has improved the reliability & availability of SST-1 LN{sub 2} system. - Abstract: Helium Refrigerator/Liquefier system of Steady State Superconducting Tokamak (SST-1) incorporates Liquid Nitrogen (LN{sub 2}) pre-cooling system. LN{sub 2} is used for 80 K thermal shields of SST-1, current feeder system and integrated flow distribution and control system. The LN{sub 2} management system is distributed system and requires automatic control. Initially LN{sub 2} control system had Citect based Supervisory Control and Data Acquisition (SCADA) and Koyo make Programmable Logic Controller (PLC). With the passage of time and due to unavailability of their hardware, it is being obsoleted. So, the requirements of new PLC and SCADA systems have been envisaged to make uninterruptable operation of SST-1 cryogenic system. Therefore, Wonderware SCADA and Schneider Electric make PLC is programmed to replace Citect SCADA and Koyo PLC. New control features have been added in upgraded control system for better management of LN{sub 2} system. This upgradation of SCADA and PLC is completed, tested successfully and in operation. Operational performance highlights of the new upgraded system are presented in this paper.

Formation, stability and structural characterization of ternary MgUO{sub 2}(CO{sub 3}){sub 3}{sup 2-} and Mg{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) complexes

Energy Technology Data Exchange (ETDEWEB)

Lee, Jun-Yeop; Yun, Jong-Il [KAIST, Daejeon (Korea, Republic of). Dept. of Nuclear and Quantum Engineering; Vespa, Marika; Gaona, Xavier; Dardenne, Kathy; Rothe, Joerg; Rabung, Thomas; Altmaier, Marcus [Karlsruhe Institute of Technology, Karlsruhe (Germany). Inst. for Nuclear Waste Disposal

2017-06-01

The formation of ternary Mg-UO{sub 2}-CO{sub 3} complexes under weakly alkaline pH conditions was investigated by time-resolved laser fluorescence spectroscopy (TRLFS) and extended X-ray absorption fine structure (EXAFS) and compared to Ca-UO{sub 2}-CO{sub 3} complexes. The presence of two different Mg-UO{sub 2}-C{sub 3} complexes was identified by means of two distinct fluorescence lifetimes of 17±2 ns and 51±2 ns derived from the multi-exponential decay of the fluorescence signal. Slope analysis in terms of fluorescence intensity coupled with fluorescence intensity factor as a function of log [Mg(II)] was conducted for the identification of the Mg-UO{sub 2}-CO{sub 3} complexes forming. For the first time, the formation of both MgUO{sub 2}(CO{sub 3}){sub 3}{sup 2-} and Mg{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) species was confirmed and the corresponding equilibrium constants were determined as log β {sub 113}=25.8±0.3 and β {sub 213}=27.1±0.6, respectively. Complementarily, fundamental structural information for both Ca-UO{sub 2}-CO{sub 3} and Mg-UO{sub 2}-CO{sub 3} complexes was gained by extended EXAFS revealing very similar structures between these two species, except for the clearly shorter U-Mg distance (3.83 Aa) compared with U-Ca distance (4.15 Aa). These results confirmed the inner-sphere character of the Ca/Mg-UO{sub 2}-CO{sub 3} complexes. The formation constants determined for MgUO{sub 2}(CO{sub 3}){sub 3}{sup 2-} and Mg{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) species indicate that ternary Mg-UO{sub 2}-CO{sub 3} complexes contribute to the relevant uranium species in carbonate saturated solutions under neutral to weakly alkaline pH conditions in the presence of Mg(II) ions, which will induce notable influences on the U(VI) chemical species under seawater conditions.

Reentrant behavior in Cr doped bilayer manganite LaSr{sub 2}Mn{sub 2}O{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Bhatia, S.N., E-mail: snbhatia@phy.iitb.ac.in; Mohapatra, Niharika

2017-07-15

Highlights: • The FM and the AFM states merge into each other thereby creating an inhomogeneous state. • Cr{sup 3+} creates ferromagnetic moments which behave like FM relaxors. • Electric conduction takes via hopping of small polaron and not by variable range hopping of these polarons. - Abstract: We have studied the effect of replacing Mn{sup 3+} by Cr{sup 3+} on the structure, transport and magnetism in the bilayered manganite LaSr{sub 2}Mn{sub 2}O{sub 7}. Although no structural transition was observed in LaSr{sub 2}Mn{sub 2−y}Cr{sub y}O{sub 7} (0.1 ≤ y ≤ 0.6), the electrical transport and the magnetic properties were found to be affected significantly by this substitution. Substitution of Cr{sup 3+} reduces the conductivity by restricting the hopping of small polarons. Magnetization increases with increasing Cr{sup 3+} concentration suggesting that Cr{sup 3+}-ions induce ferromagnetic moments. The ferromagnetic and an antiferromagnetic phase observed above ∼60 K merge into an inhomogeneous phase below this temperature. Thermopower yields an essentially concentration independent charge density nearly equal to its value for chromium free composition inspite of its expected decrease with this substitution suggesting that the small charge density of the insulating AFM phase is supplemented by the free carriers in the FM phase. The inhomogeneous phase shows a relaxor type behavior which contrasts with the spin glass behavior seen in La{sub 0.46}Sr{sub 0.54}Mn{sub 0.98}Cr{sub 0.02}O{sub 3} having an identical AFM magnetic state. The difference is attributed to the non-JT character of Cr-ions which reduce the distortion of the Mn−O octahedra located within the FM domains. With a higher lattice strain in the surrounding AFM matrix the carriers remain confined within the FM domains leading to the relaxor type behavior.

The defects influence on domain wall propagation in bistable glass-coated microwires

Energy Technology Data Exchange (ETDEWEB)

Rodionova, V. [Magnetism Division, Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Immanuel Kant Baltic Federal University, Kaliningrad 236041 (Russian Federation); Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, San Sebastian 20018 (Spain); Zhukova, V., E-mail: valentina.zhukova@ehu.es [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, San Sebastian 20018 (Spain); Ilyn, M.; Ipatov, M. [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, San Sebastian 20018 (Spain); Perov, N. [Magnetism Division, Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Zhukov, A. [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, San Sebastian 20018 (Spain); IKERBASQUE, Basque Foundation for Science, Bilbao 48011 (Spain)

2012-05-01

We studied the domain wall (DW) dynamics of magnetically bistable amorphous glass-coated Fe{sub 74}B{sub 13}Si{sub 11}C{sub 2} microwires. In according to our experimental results magnetic field dependences of DW velocity of studied microwires can be divided into two groups: with uniform or uniformly accelerated DW propagation along the microwire. Strong correlation between the type of the magnetic field dependence of domain wall velocity, v(H), and the distribution of the local nucleation fields has been observed. Moreover, we observed abrupt increasing of DW velocity (jump) on the magnetic field dependences of the domain wall velocity, v(H), for the both types of the v(H) dependences. At the same time usual linear increasing of the domain wall velocity with magnetic field persists below these jumps. It was found that the jump height correlates with the location of nucleation place of the new domain wall. We have measured local nucleation field distribution in all the microwires. From local nucleation field distribution we have obtained the DW nucleation locations and estimated the jump height.

Perovskite-type La{sub 2}Ti{sub 2}O{sub 7} mesoporous photocatalyst

Energy Technology Data Exchange (ETDEWEB)

Onozuka, K.; Kawakami, Y.; Imai, H.; Yokoi, T.; Tatsumi, T. [Chemical Resources Laboratory, Tokyo Institute of Technology, R1-10, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan); Kondo, J.N., E-mail: jnomura@res.titech.ac.jp [Chemical Resources Laboratory, Tokyo Institute of Technology, R1-10, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan)

2012-08-15

Crystalline particles of mesoporous La{sub 2}Ti{sub 2}O{sub 7}, a perovskite-type material, were prepared by hydrothermal synthesis at 210 Degree-Sign C in the presence of structure directing agent. Crystallization and simultaneous sintering occurred in the time course of the hydrothermal treatment, resulting in the improvement in crystallinity with a sacrifice of the decrease in surface area. The photocatalytic property was evaluated by hydrogen evolution from water with methanol sacrificial agent. The increase and the decrease of the material in crystallinity and surface area were responsible for the photocatalytic activity: the activity was improved by crystallization but the concurrent decrease in surface area (increase in size) of crystalline particles was disadvantageous. - Graphical abstract: A homogeneous mixture of La and Ti oxide with amorphous inorganic network was hydrothermally crystallized at low temperatures to a perovskite-type La{sub 2}Ti{sub 2}O{sub 7}. The small La{sub 2}Ti{sub 2}O{sub 7} particles with high crystallinity showed a potential as a photocatalyst for H{sub 2} evolution. Highlights: Black-Right-Pointing-Pointer Crystalline mesopourous La{sub 2}Ti{sub 2}O{sub 7} was prepared. Black-Right-Pointing-Pointer Hydrothermal treatment encouraged low temperature crystallization. Black-Right-Pointing-Pointer Small crystalline domain was advantageous to a photocatalytic reaction.

The SACSESS hydrometallurgy domain - an overview

Energy Technology Data Exchange (ETDEWEB)

Geist, A. [Karlsruhe Institute of Technology - KIT, Institute for Nuclear Wsaste Disposal - INE, Karlsruhe (Germany); Taylor, R. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, CA20 1PG (United Kingdom); Ekberg, C. [Chalmers University of Technology, Nuclear Chemistry/Industrial Materials Recycling, SE-412 96 Goeteborg (Sweden); Guilbaud, P.; Bourg, S. [CEA, Centre de Marcoule, Nuclear Energy Division, F-30207 Bagnols-sur-Ceze (France); Modolo, G. [Forschungszentrum Juelich GmbH - FZJ, Institut fuer Energie- und Klimaforschung - IEK-6, Juelich (Germany)

2016-07-01

The EURATOM FP7 project SACSESS (Safety of Actinide Separation Processes) is in continuity of a long line of preceding EURATOM projects. SACSESS is organised along four domains, one of them related to the development of hydrometallurgical (i.e. solvent extraction based) actinide separations processes. Within this domain, the most promising processes developed in previous projects are further developed, improving their technology readiness level (TRL) towards the point at which safe industrial implementation will be achievable. The SACSESS reference compounds are: TODGA, CyMe{sub 4}-BTBP, SO{sub 3}-Ph-BTP, HEDTA and DTPA. TODGA is used to co-extract actinides and lanthanides from high-acidity raffinate solutions, separating from the non-lanthanide fission products. TODGA is also used to accelerate the extraction kinetics of CyMe{sub 4}-BTBP. CyMe{sub 4}-BTBP extracts actinides selectively over lanthanides and many other fission products. HEDTA and DTPA are used to strip actinides selectively over lanthanides from an organic phase containing both actinides and lanthanides. SO{sub 3}-Ph-BTP was developed to overcome some of the drawbacks of HEDTA and DTPA, such as the narrow pH window they are effective in.

Electrochemistry and spectroelectrochemistry of tert-butylcalix[4]arene bridged bis double-decker lutetium(III) phthalocyanine, Lu{sub 2}Pc{sub 4} and dimeric lutetium(III) phthalocyanine, Lu{sub 2}Pc{sub 2}(OAc){sub 2}

Energy Technology Data Exchange (ETDEWEB)

Koca, Atif [Chemical Engineering Department, Engineering Faculty, Marmara University, TR34722 Goeztepe, Istanbul (Turkey); Ceyhan, Tanju; Erbil, Mehmet K. [Department of Biochemistry, Division of Organic Chemistry, Guelhane Medical Academy (GATA), Ankara (Turkey); Ozkaya, Ali Riza [Department of Chemistry, Marmara University, TR34722 Goeztepe, Istanbul (Turkey)], E-mail: aliozkaya@marmara.edu.tr; Bekaroglu, Ozer [Department of Chemistry, Technical University of Istanbul, TR34469 Maslak, Istanbul (Turkey)], E-mail: obek@itu.edu.tr

2007-11-09

In this study, electrochemical, electrochromic and spectroelectrochemical properties of a tert-butylcalix[4]arene bridged bis double-decker lutetium(III) phthalocyanine (Lu{sub 2}Pc{sub 4}2) were investigated explicitly as compared with a tert-butylcalix[4]arene bridged dimeric lutetium(III) phthalocyanine [Lu{sub 2}Pc{sub 2}(OAc){sub 2}1]. Distinctive differences between electrochemical and electrochromic properties of 1 and 2 were detected. Moreover, the properties of 1 and 2 were compared with previously reported S{sub 4}(CH{sub 2}){sub 4} bridged Lu{sub 2}Pc{sub 2}(OAc){sub 2} and Lu{sub 2}Pc{sub 4}. The calixarene bridged phthalocyanine (Pc) compounds, 1 and 2 showed well-defined electrochromic behaviour with green-blue and blue-purple colour transitions. The enhanced electrochromic properties of 2, as compared to 1, were attributed to its double-decker structure, probably allowing the formation of suitable ion channels for the counter ion movement in the solid film.

Effective crop evapotranspiration measurement using time-domain reflectometry technique in a sub-humid region

Science.gov (United States)

Srivastava, R. K.; Panda, R. K.; Halder, Debjani

2017-08-01

The primary objective of this study was to evaluate the performance of the time-domain reflectometry (TDR) technique for daily evapotranspiration estimation of peanut and maize crop in a sub-humid region. Four independent methods were used to estimate crop evapotranspiration (ETc), namely, soil water balance budgeting approach, energy balance approach—(Bowen ratio), empirical methods approach, and Pan evaporation method. The soil water balance budgeting approach utilized the soil moisture measurement by gravimetric and TDR method. The empirical evapotranspiration methods such as combination approach (FAO-56 Penman-Monteith and Penman), temperature-based approach (Hargreaves-Samani), and radiation-based approach (Priestley-Taylor, Turc, Abetw) were used to estimate the reference evapotranspiration (ET0). The daily ETc determined by the FAO-56 Penman-Monteith, Priestley-Taylor, Turc, Pan evaporation, and Bowen ratio were found to be at par with the ET values derived from the soil water balance budget; while the methods Abetw, Penman, and Hargreaves-Samani were not found to be ideal for the determination of ETc. The study illustrates the in situ applicability of the TDR method in order to make it possible for a user to choose the best way for the optimum water consumption for a given crop in a sub-humid region. The study suggests that the FAO-56 Penman-Monteith, Turc, and Priestley-Taylor can be used for the determination of crop ETc using TDR in comparison to soil water balance budget.

Epitaxial Sb-doped SnO{sub 2} and Sn-doped In{sub 2}O{sub 3} transparent conducting oxide contacts on GaN-based light emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Tsai, Min-Ying [Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106 (United States); Bierwagen, Oliver, E-mail: bierwagen@pdi-berlin.de [Materials Department, University of California, Santa Barbara, CA 93106 (United States); Paul-Drude-Insitut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany); Speck, James S. [Materials Department, University of California, Santa Barbara, CA 93106 (United States)

2016-04-30

We demonstrate the growth of epitaxial (100)-oriented, rutile Sb-doped SnO{sub 2} (ATO) and (111)-oriented, cubic Sn-doped In{sub 2}O{sub 3} (ITO) transparent conducting oxide (TCO) contacts on top of an InGaN/GaN(0001) light emitting diode (LED) by plasma-assisted molecular beam epitaxy (PAMBE). Both oxides form rotational domains. The in-plane epitaxial alignment of the two ITO(111) rotational domains to the GaN(0001) was: GaN [21-10]|| ITO{sub Domain1}[‐ 211]|| ITO{sub Domain2}[‐ 1‐12]. A growth temperature as low as 600 °C was necessary to realize a low contact resistance between ATO and the top p-GaN layer of the LED but resulted in non-optimal resistivity (3.4 × 10{sup −} {sup 3} Ω cm) of the ATO. The current–voltage characteristics of a processed LED, however, were comparable to that of a reference LED with a standard electron-beam evaporated ITO top contact. At short wavelengths, the optical absorption of ATO was lower than that of ITO, which is beneficial even for blue LEDs. Higher PAMBE growth temperatures resulted in lower resistive ATO but higher contact resistance to the GaN, likely by the formation of an insulating Ga{sub 2}O{sub 3} interface layer. The ITO contact grown by PAMBE at 600 °C showed extremely low resistivity (10{sup −4} Ω cm) and high crystalline and morphological quality. These proof-of-principle results may lead to the development of epitaxial TCO contacts with low resistivity, well-defined interfaces to the p-GaN to help minimize contact losses, and enable further epitaxy on top of the TCO. - Highlights: • Plasma-assisted molecular beam epitaxy of SnO{sub 2}:Sb (ATO) and In{sub 2}O{sub 3}:Sn (ITO) contacts • Working light emitting diodes processed with the ATO contact on the top p-GaN layer • Low growth temperature ensures low contact resistance (limiting interface reaction). • ITO showed significantly better structural and transport properties than ATO. • ATO showed higher optical transmission at short

Preparation, crystallography, magnetic and magnetothermal properties of Ce<sub>5sub>Si_xGe>4-xsub> alloys

Energy Technology Data Exchange (ETDEWEB)

Vijayaraghavan, Rangarajan [Iowa State Univ., Ames, IA (United States)

2005-01-01

An investigation of the crystal structure and the phase relationships in the Ce<sub>5sub>Si>4-xsub>Ge_x> system has been carried out. The crystal structures of the single phase intermetallics were characterized using X-ray powder diffraction and subsequent refinement employing the Rietveld analysis technique was performed. The intermetallic system was found to crystallize in three distinct crystal structures. The Ce<sub>5sub>Si>4sub>-based solid solution extends from x = 0 to x = 2.15 and it was found to crystallize in the well-known Zr<sub>5sub>Si>4sub>-type tetragonal structure. The germanium rich alloys, where 3.1 ≤} x ≤ 4, crystallized in the Sm<sub>5sub>Ge>4sub>-type orthorhombic structure. The crystal structure of the intermediate phase, when 2.35 ≤ x ≤ 2.8, was found out to be of the Gd<sub>5sub>Si>2sub>Ge>2sub>-type monoclinic structure. Microhardness tests were conducted on the samples in order to probe the trend in mechanical properties in this alloy system as a function of Ge concentration. The magnetic, thermal and magnetocaloric properties of the Ce<sub>5sub>Si>4-xsub>Ge_x> alloy system have been investigated for x = 0, 1.0, 1.8, 2.5, 2.8, 3.5, 3.8 and 4.0. The phases with x = 0, 1.0 and 1.8 crystallize in the tetragonal Zr<sub>5sub>Si>4sub> structure and those with x = 2.5, 2.8 form in the Gd<sub>5sub>Si>2sub>Ge>2sub>-type monoclinic structure. The alloys with x = 3.5, 3.8 and 4.0 crystallize in the Sm<sub>5sub>Ge>4sub>-type orthorhombic structure. The Curie temperature of the tetragonal phases increases with increasing Ge content. The ordering temperatures of the monoclinic and orthorhombic phases remain nearly unaffected by the composition, with the Curie temperatures of the latter slightly higher than those of the former. All the alloys display evidence of antiferromagnetic interactions in the ground state. The orthorhombic and the

Synthesis of SrCo {sub x} Ti {sub x} Fe{sub (12-2{sub x})}O{sub 19} through sol-gel auto-ignition and its characterisation

Energy Technology Data Exchange (ETDEWEB)

Thompson, Simon [Chemistry and Physics, Nottingham Trent University, Clifton Lane, Clifton, Nottingham, NG11 8NS (United Kingdom); Shirtcliffe, Neil J. [Chemistry and Physics, Nottingham Trent University, Clifton Lane, Clifton, Nottingham, NG11 8NS (United Kingdom)]. E-mail: neil.shirtcliffe@ntu.ac.uk; O' Keefe, Eoin S. [QinetiQ, Farnborough, Hampshire (United Kingdom); Appleton, Steve [QinetiQ, Farnborough, Hampshire (United Kingdom); Perry, Carole C. [Chemistry and Physics, Nottingham Trent University, Clifton Lane, Clifton, Nottingham, NG11 8NS (United Kingdom)]. E-mail: carole.perry@ntu.ac.uk

2005-04-15

Cobalt-titanium-doped strontium hexaferrites SrCo {sub x} Ti {sub x} Fe{sub (12-2{sub x})}O{sub 19} were synthesised via a sol-gel route using two different complexing agents (ethylene glycol and citric acid). Both routes led to quite pure undoped Sr ferrites, but the citric acid route formed purer doped materials. All synthesised materials consisted of particles smaller than 1 {mu}m, which is the size of a single magnetic domain, and various doping levels were achieved with the final elemental composition being within the bounds of experimental error. The materials synthesised using citric acid were compared with materials synthesised by a solid-state route using ferromagnetic resonance measurements and they were identical within experimental error. Citrate auto-ignition synthesis is more rapid and less prone to contamination than the standard solid-state method and doping levels can be easily varied between runs.

Europlexus: a domain decomposition method in explicit dynamics

International Nuclear Information System (INIS)

Faucher, V.; Hariddh, Bung; Combescure, A.

2003-01-01

Explicit time integration methods are used in structural dynamics to simulate fast transient phenomena, such as impacts or explosions. A very fine analysis is required in the vicinity of the loading areas but extending the same method, and especially the same small time-step, to the whole structure frequently yields excessive calculation times. We thus perform a dual Schur domain decomposition, to divide the global problem into several independent ones, to which is added a reduced size interface problem, to ensure connections between sub-domains. Each sub-domain is given its own time-step and its own mesh fineness. Non-matching meshes at the interfaces are handled. An industrial example demonstrates the interest of our approach. (authors)

Troponin T3 regulates nuclear localization of the calcium channel Ca{sub v}β{sub 1a} subunit in skeletal muscle

Energy Technology Data Exchange (ETDEWEB)

Zhang, Tan; Taylor, Jackson; Jiang, Yang [Department of Internal Medicine-Gerontology, Wake Forest School of Medicine, Winston-Salem, NC 27157 (United States); Pereyra, Andrea S. [Department of Histology, National University of La Plata, 1900 La Plata (Argentina); Messi, Maria Laura; Wang, Zhong-Min [Department of Internal Medicine-Gerontology, Wake Forest School of Medicine, Winston-Salem, NC 27157 (United States); Hereñú, Claudia [Department of Histology, National University of La Plata, 1900 La Plata (Argentina); Delbono, Osvaldo, E-mail: odelbono@wakehealth.edu [Department of Internal Medicine-Gerontology, Wake Forest School of Medicine, Winston-Salem, NC 27157 (United States); Neuroscience Program, Wake Forest School of Medicine, Winston-Salem, NC 27157 (United States)

2015-08-15

The voltage-gated calcium channel (Ca{sub v}) β{sub 1a} subunit (Ca{sub v}β{sub 1a}) plays an important role in excitation–contraction coupling (ECC), a process in the myoplasm that leads to muscle-force generation. Recently, we discovered that the Ca{sub v}β{sub 1a} subunit travels to the nucleus of skeletal muscle cells where it helps to regulate gene transcription. To determine how it travels to the nucleus, we performed a yeast two-hybrid screening of the mouse fast skeletal muscle cDNA library and identified an interaction with troponin T3 (TnT3), which we subsequently confirmed by co-immunoprecipitation and co-localization assays in mouse skeletal muscle in vivo and in cultured C2C12 muscle cells. Interacting domains were mapped to the leucine zipper domain in TnT3 COOH-terminus (160–244 aa) and Ca{sub v}β{sub 1a} NH{sub 2}-terminus (1–99 aa), respectively. The double fluorescence assay in C2C12 cells co-expressing TnT3/DsRed and Ca{sub v}β{sub 1a}/YFP shows that TnT3 facilitates Ca{sub v}β{sub 1a} nuclear recruitment, suggesting that the two proteins play a heretofore unknown role during early muscle differentiation in addition to their classical role in ECC regulation. - Highlights: • Previously, we demonstrated that Ca{sub v}β{sub 1a} is a gene transcription regulator. • Here, we show that TnT3 interacts with Ca{sub v}β{sub 1a}. • We mapped TnT3 and Ca{sub v}β{sub 1a} interaction domain. • TnT3 facilitates Ca{sub v}β{sub 1a} nuclear enrichment. • The two proteins play a heretofore unknown role during early muscle differentiation.

Geometric Control Over the Motion of Magnetic Domain Walls

International Nuclear Information System (INIS)

N.A. Sinitsyn; V.V. Dobrovitski; S. urazhdin; Avadh Saxena

2008-01-01

We propose a method that enables a precise control of magnetic patterns and relies only on the fundamental properties of the wire as well as on the choice of the path in the controlled parameter space but not on the rate of motion along this path. Possible experimental realizations of this mechanism are discussed. In particular, we show that the domain walls in magnetic nanowires can be translated by rotation of the magnetic easy axis or by applying pulses of magnetic field directed transverse to the magnetic easy axis

Disorder influence on the magnetic properties of La{sub 0.55}Sr{sub 0.45}MnO{sub 3}/SrTiO{sub 3} superlattices

Energy Technology Data Exchange (ETDEWEB)

Haberkorn, N. E-mail: nhaberk@cab.cnea.gov.ar; Sirena, M.; Guimpel, J.; Steren, L.B

2004-05-01

The structural and physical properties of La{sub 0.55}Sr{sub 0.45}MnO{sub 3}/SrTiO{sub 3} superlattices grown by magnetron sputtering are studied. Two deposition temperatures and different mismatched substrates and buffer layers were used. The structure was determined by refinement through X-ray diffraction pattern fitting. The results indicate 1 unit cell (u.c.) interdiffusion at the interfaces and a 1 u.c. layer thickness fluctuation, i.e. roughness. In-plane hysteresis loops show the expected ferromagnetic behavior, while the perpendicular-to-plane hysteresis loops show anomalies which could evidence magnetic domain size inhomogeneities and stress.

Practical iterative learning control with frequency domain design and sampled data implementation

CERN Document Server

Wang, Danwei; Zhang, Bin

2014-01-01

This book is on the iterative learning control (ILC) with focus on the design and implementation. We approach the ILC design based on the frequency domain analysis and address the ILC implementation based on the sampled data methods. This is the first book of ILC from frequency domain and sampled data methodologies. The frequency domain design methods offer ILC users insights to the convergence performance which is of practical benefits. This book presents a comprehensive framework with various methodologies to ensure the learnable bandwidth in the ILC system to be set with a balance between learning performance and learning stability. The sampled data implementation ensures effective execution of ILC in practical dynamic systems. The presented sampled data ILC methods also ensure the balance of performance and stability of learning process. Furthermore, the presented theories and methodologies are tested with an ILC controlled robotic system. The experimental results show that the machines can work in much h...

On the kinetic and thermodynamic fragility of the Pt{sub 60}Cu{sub 16}Co{sub 2}P{sub 22} and Pt{sub 57.3}Cu{sub 14.6}Ni{sub 5.3}P{sub 22.8} bulk metallic glasses

Energy Technology Data Exchange (ETDEWEB)

Gallino, Isabella, E-mail: i.gallino@mx.uni-saarland.de [Saarland University, Department of Materials Science and Engineering, Campus C6.3, 66123 Saarbruecken (Germany); Gross, Oliver [Saarland University, Department of Materials Science and Engineering, Campus C6.3, 66123 Saarbruecken (Germany); Dalla Fontana, Giulia [Department of Chemistry IFM and NIS, University of Torino, V. Giuria 7, 10125 Torino (Italy); Evenson, Zach; Busch, Ralf [Saarland University, Department of Materials Science and Engineering, Campus C6.3, 66123 Saarbruecken (Germany)

2014-12-05

Highlights: • The studied Pt–Cu–(Ni,Co)–P glasses are more fragile than Zr-based alloys. • They show large increases in the C{sub p} at T{sub g} and small barriers for cooperative rearrangements of atoms. • They have fragility parameters among the lowest reported for BMG systems (D{sup *} = 10–12). • They crystallize into a state that melts with distinctly high entropy of fusion. • The microscopic origin of their fragility seems different than that for Zr- and Pd-based BMGs. - Abstract: The investigations in this study focus on bulk metallic glass (BMG) alloy families based on noble metals like Pt, which are more kinetically fragile than Zr-based BMG systems. Thermophysical properties have been investigated by calorimetry and thermal mechanical analyses for the determination of the specific heat capacity and viscosity, respectively. For the Pt{sub 60}Cu{sub 16}Co{sub 2}P{sub 22} and Pt{sub 57.3}Cu{sub 14.6}Ni{sub 5.3}P{sub 22.8} BMG compositions consistent Vogel–Fulcher–Tammann (VFT) fits of the viscosity measurements are established, and the temperature dependence of the configurational entropy is calculated from thermodynamic data. Fits to the Adam–Gibbs equation are performed using this configurational entropy change. Their fragile nature is compared to that of Zr-based alloys in terms of structural considerations.

Molecular dynamics simulations of site point mutations in the TPR domain of cyclophilin 40 identify conformational states with distinct dynamic and enzymatic properties

Science.gov (United States)

Gur, Mert; Blackburn, Elizabeth A.; Ning, Jia; Narayan, Vikram; Ball, Kathryn L.; Walkinshaw, Malcolm D.; Erman, Burak

2018-04-01

Cyclophilin 40 (Cyp40) is a member of the immunophilin family that acts as a peptidyl-prolyl-isomerase enzyme and binds to the heat shock protein 90 (Hsp90). Its structure comprises an N-terminal cyclophilin domain and a C-terminal tetratricopeptide (TPR) domain. Cyp40 is overexpressed in prostate cancer and certain T-cell lymphomas. The groove for Hsp90 binding on the TPR domain includes residues Lys227 and Lys308, referred to as the carboxylate clamp, and is essential for Cyp40-Hsp90 binding. In this study, the effect of two mutations, K227A and K308A, and their combinative mutant was investigated by performing a total of 5.76 μs of all-atom molecular dynamics (MD) simulations in explicit solvent. All simulations, except the K308A mutant, were found to adopt two distinct (extended or compact) conformers defined by different cyclophilin-TPR interdomain distances. The K308A mutant was only observed in the extended form which is observed in the Cyp40 X-ray structure. The wild-type, K227A, and combined mutant also showed bimodal distributions. The experimental melting temperature, Tm, values of the mutants correlate with the degree of compactness with the K308A extended mutant having a marginally lower melting temperature. Another novel measure of compactness determined from the MD data, the "coordination shell volume," also shows a direct correlation with Tm. In addition, the MD simulations show an allosteric effect with the mutations in the remote TPR domain having a pronounced effect on the molecular motions of the enzymatic cyclophilin domain which helps rationalise the experimentally observed increase in enzyme activity measured for all three mutations.

Electric-field-induced strain contributions in morphotropic phase boundary composition of (Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-BaTiO{sub 3} during poling

Energy Technology Data Exchange (ETDEWEB)

Khansur, Neamul H.; Daniels, John E. [School of Materials Science and Engineering, UNSW Australia, New South Wales 2052 (Australia); Hinterstein, Manuel [School of Materials Science and Engineering, UNSW Australia, New South Wales 2052 (Australia); Institute for Applied Materials, Karlsruhe Institute for Technology, P.O. Box 3640, 76021 Karlsruhe (Germany); Wang, Zhiyang [School of Materials Science and Engineering, UNSW Australia, New South Wales 2052 (Australia); The Australian Synchrotron, Clayton, Victoria 3168 (Australia); Groh, Claudia [Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Jo, Wook [School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919 (Korea, Republic of)

2015-12-14

The microscopic contributions to the electric-field-induced macroscopic strain in a morphotropic 0.93(Bi{sub 1/2}Na{sub 1/2}TiO{sub 3})−0.07(BaTiO{sub 3}) with a mixed rhombohedral and tetragonal structure have been quantified using full pattern Rietveld refinement of in situ high-energy x-ray diffraction data. The analysis methodology allows a quantification of all strain mechanisms for each phase in a morphotropic composition and is applicable to use in a wide variety of piezoelectric compositions. It is shown that during the poling of this material 24%, 44%, and 32% of the total macroscopic strain is generated from lattice strain, domain switching, and phase transformation strains, respectively. The results also suggest that the tetragonal phase contributes the most to extrinsic domain switching strain, whereas the lattice strain primarily stems from the rhombohedral phase. The analysis also suggests that almost 32% of the total strain is lost or is a one-time effect due to the irreversible nature of the electric-field-induced phase transformation in the current composition. This information is relevant to on-going compositional development strategies to harness the electric-field-induced phase transformation strain of (Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-based lead-free piezoelectric materials for actuator applications.

Distinctive functions of Syk N-terminal and C-terminal SH2 domains in the signaling cascade elicited by oxidative stress in B cells.

Science.gov (United States)

Ding, J; Takano, T; Hermann, P; Gao, S; Han, W; Noda, C; Yanagi, S; Yamamura, H

2000-05-01

Syk plays a crucial role in the transduction of oxidative stress signaling. In this paper, we investigated the roles of Src homology 2 (SH2) domains of Syk in oxidative stress signaling, using Syk-negative DT40 cells expressing the N- or C-terminal SH2 domain mutant [mSH2(N) or mSH2(C)] of Syk. Tyrosine phosphorylation of Syk in cells expressing mSH2(N) Syk after H(2)O(2) treatment was higher than that in cells expressing wild-type Syk or mSH2(C) Syk. The tyrosine phosphorylation of wild-type Syk and mSH2(C) Syk, but not that of mSH2(N), was sensitive to PP2, a specific inhibitor of Src-family protein-tyrosine kinase. In oxidative stress, the C-terminal SH2 domain of Syk was demonstrated to be required for induction of tyrosine phosphorylation of cellular proteins, phospholipase C (PLC)-gamma2 phosphorylation, inositol 1,4, 5-triphosphate (IP(3)) generation, Ca(2)(+) release from intracellular stores, and c-Jun N-terminal kinase activation. In contrast, in mSH2(N) Syk-expressing cells, tyrosine phosphorylation of intracellular proteins including PLC-gamma2 was markedly induced in oxidative stress. The enhanced phosphorylation of mSH2(N) Syk and PLC-gamma2, however, did not link to Ca(2)(+) mobilization from intracellular pools and IP(3) generation. Thus, the N- and C-terminal SH2 domains of Syk possess distinctive functions in oxidative stress signaling.

Controllable synthesis of Zn{sub 2}TiO{sub 4}-carbon core/shell nanofibers with high photocatalytic performance

Energy Technology Data Exchange (ETDEWEB)

Zhang, Peng [Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024 (China); Shao, Changlu, E-mail: clshao@nenu.edu.cn [Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024 (China); Zhang, Mingyi; Guo, Zengcai; Mu, Jingbo; Zhang, Zhenyi; Zhang, Xin; Liang, Pingping; Liu, Yichun [Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024 (China)

2012-08-30

Graphical abstract: We describe a controllable route to synthesize Zn{sub 2}TiO{sub 4}-carbon core/shell nanofibers with different thickness of carbon layers (from 2 to 8 nm) as high efficiency photocatalysts. Highlights: Black-Right-Pointing-Pointer Synthesis of Zn{sub 2}TiO{sub 4}-carbon nanofibers with different thickness of carbon layers. Black-Right-Pointing-Pointer Zn{sub 2}TiO{sub 4}-carbon NFs showed photocatalytic activity for the degradation of Rhodamine B. Black-Right-Pointing-Pointer Easy photocatalyst separation and reuse. Black-Right-Pointing-Pointer A general way to fabricate other carbon-coated core/shell photocatalysts. - Abstract: Zn{sub 2}TiO{sub 4}-carbon core/shell nanofibers (Zn{sub 2}TiO{sub 4}-C NFs) with different thickness of carbon layers (from 2 to 8 nm) were fabricated by combining the electrospinning technique and hydrothermal method. The results showed that a uniform carbon layer was formed around the electrospun Zn{sub 2}TiO{sub 4} nanofiber (Zn{sub 2}TiO{sub 4} NFs). By adjusting the hydrothermal fabrication parameters, the thickness of carbon layer varied linearly with the concentration of glucose. Furthermore, the core/shell structure formed between Zn{sub 2}TiO{sub 4} and carbon enhanced the charge separation of pure Zn{sub 2}TiO{sub 4} under ultraviolet excitation, as evidenced by photoluminescence spectra. The photocatalytic studies revealed that the Zn{sub 2}TiO{sub 4}-C NFs exhibited enhanced photocatalytic efficiency of photodegradation of Rhodamine B (RB) compared with the pure Zn{sub 2}TiO{sub 4} NFs under ultraviolet excitation, which might be attributed to the high separation efficiency of photogenerated electrons and holes based on the synergistic effect between carbon and Zn{sub 2}TiO{sub 4}. Notably, the Zn{sub 2}TiO{sub 4}-C NFs could be recycled easily by sedimentation without a decrease of the photocatalytic activity.

Control of crystallization kinetics and study of the thermal, structural and morphological properties of an Li{sub 2}O-B{sub 2}O{sub 3}-Al{sub 2}O{sub 3} vitreous system

Energy Technology Data Exchange (ETDEWEB)

Dantas, Noelio O.; Silva, Valdeir A., E-mail: noelio@ufu.br [Universidade Federal de Uberlandia (LNMIS/UFU), MG (Brazil). Instituto de Fisica. Laboratorio de Novos Materials Isolantes a Semicondutores; Neto, O.O.D. [Universidade Federal de Uberlandia (GOIQ/UFU), MG (Brazil). Instituto de Fisica. Grupo de Optica e Informacao Quantica; Nascimento, Marcio L.F. [Vitreous Materials Laboratory, Institute of Humanities, Arts and Sciences, Federal University of Bahia, Salvador, BA (Brazil); PROTEC/PEI-Postgraduate Program in Industrial Engineering, Department of Chemical Engineering. Polytechnic School, Federal University of Bahia, Salvador (Brazil)

2012-07-01

A glass matrix with nominal composition 50Li{sub 2}O.45B{sub 2}O{sub 3}.5Al{sub 2}O{sub 3} (mol%) was synthesized, and its physical properties were investigated by differential thermal analysis (DTA), X-ray diffraction (XRD), and atomic force microscopy (AFM). The glass transition temperature T{sub g}, the crystallization-onset temperature T{sub x}, the crystallization peak temperatures T{sub c1} and T{sub c2}. and the fusion peak temperatures T{sub m1} and T{sub m2} were determined from at least two glass matrix phases to be approximately 382, 457, 486, 574, 761, and 787 °C, respectively, at 5 °C/min heating rate. Heat treatments at 450 °C for an increasing sequence of time intervals allowed control over the amount of crystallization. Additional information on the crystallization kinetics for the LBA glass matrix was gathered from AFM images, DTA thermograms, and XRD diffractograms. The latter technique showed that LiBO{sub 2} (ICDD-16568) and Li{sub 3}AIB{sub 2}O{sub 6} (ICDD- 51754) phases are formed in the glass-ceramic system. Debye-Schemer analysis of the XRD peaks revealed a competition between the evolutions of crystal phases during heat treatment. Activation energies for crystallization, obtained from theoretical models applied to the DTA data showed that the crystallization is heterogeneous. The AFM images demonstrated that this heterogeneous crystallization starts at the surface of the LBA glass matrix and identified crystal sizes in agreement with the results of the Debye-Schemer analysis. Our study shows that thermal and structural characterization techniques can be combined with theoretical results drawn from well-tested models to offer a unified view of crystallization in a glass-ceramics system. (author)

Computational Design of High-χ Block Oligomers for Accessing 1 nm Domains.

Science.gov (United States)

Chen, Qile P; Barreda, Leonel; Oquendo, Luis E; Hillmyer, Marc A; Lodge, Timothy P; Siepmann, J Ilja

2018-05-22

Molecular dynamics simulations are used to design a series of high-χ block oligomers (HCBOs) that can self-assemble into a variety of mesophases with domain sizes as small as 1 nm. The exploration of these oligomers with various chain lengths, volume fractions, and chain architectures at multiple temperatures reveals the presence of ordered lamellae, perforated lamellae, and hexagonally packed cylinders. The achieved periods are as small as 3.0 and 2.1 nm for lamellae and cylinders, respectively, which correspond to polar domains of approximately 1 nm. Interestingly, the detailed phase behavior of these oligomers is distinct from that of either solvent-free surfactants or block polymers. The simulations reveal that the behavior of these HCBOs is a product of an interplay between both "surfactant factors" (headgroup interactions, chain flexibility, and interfacial curvature) and "block polymer factors" (χ, chain length N, and volume fraction f). This insight promotes the understanding of molecular features pivotal for mesophase formation at the sub-5 nm length scale, which facilitates the design of HCBOs tailored toward particular desired morphologies.

Molecular Evolution of the Oxygen-Binding Hemerythrin Domain.

Directory of Open Access Journals (Sweden)

Claudia Alvarez-Carreño

Full Text Available The evolution of oxygenic photosynthesis during Precambrian times entailed the diversification of strategies minimizing reactive oxygen species-associated damage. Four families of oxygen-carrier proteins (hemoglobin, hemerythrin and the two non-homologous families of arthropodan and molluscan hemocyanins are known to have evolved independently the capacity to bind oxygen reversibly, providing cells with strategies to cope with the evolutionary pressure of oxygen accumulation. Oxygen-binding hemerythrin was first studied in marine invertebrates but further research has made it clear that it is present in the three domains of life, strongly suggesting that its origin predated the emergence of eukaryotes.Oxygen-binding hemerythrins are a monophyletic sub-group of the hemerythrin/HHE (histidine, histidine, glutamic acid cation-binding domain. Oxygen-binding hemerythrin homologs were unambiguously identified in 367/2236 bacterial, 21/150 archaeal and 4/135 eukaryotic genomes. Overall, oxygen-binding hemerythrin homologues were found in the same proportion as single-domain and as long protein sequences. The associated functions of protein domains in long hemerythrin sequences can be classified in three major groups: signal transduction, phosphorelay response regulation, and protein binding. This suggests that in many organisms the reversible oxygen-binding capacity was incorporated in signaling pathways. A maximum-likelihood tree of oxygen-binding hemerythrin homologues revealed a complex evolutionary history in which lateral gene transfer, duplications and gene losses appear to have played an important role.Hemerythrin is an ancient protein domain with a complex evolutionary history. The distinctive iron-binding coordination site of oxygen-binding hemerythrins evolved first in prokaryotes, very likely prior to the divergence of Firmicutes and Proteobacteria, and spread into many bacterial, archaeal and eukaryotic species. The later evolution of the

In-plane pitch control of cholesteric liquid crystals by formation of artificial domains via patterned photopolymerization.

Science.gov (United States)

Yoshida, Hiroyuki; Miura, Yusuke; Tokuoka, Kazuki; Suzuki, Satoshi; Fujii, Akihiko; Ozaki, Masanori

2008-11-10

A controlled helix pitch modulation in the in-plane direction of a planarly aligned cholesteric liquid crystal cell is demonstrated by using photopolymerizable cholesteric liquid crystals. By fabricating artificial domains with a closed volume via two-photon excitation laser-lithography, the degree of pitch modulation could be controlled by adjusting the surface area to volume ratio of the domain. A pitch modulation of over 60 nm was realized by designing the shape of the artificial domain.

Distinct collective states due to trade-off between attractive and repulsive couplings

Science.gov (United States)

Sathiyadevi, K.; Chandrasekar, V. K.; Senthilkumar, D. V.; Lakshmanan, M.

2018-03-01

We investigate the effect of repulsive coupling together with an attractive coupling in a network of nonlocally coupled oscillators. To understand the complex interaction between these two couplings we introduce a control parameter in the repulsive coupling which plays a crucial role in inducing distinct complex collective patterns. In particular, we show the emergence of various cluster chimera death states through a dynamically distinct transition route, namely the oscillatory cluster state and coherent oscillation death state as a function of the repulsive coupling in the presence of the attractive coupling. In the oscillatory cluster state, the oscillators in the network are grouped into two distinct dynamical states of homogeneous and inhomogeneous oscillatory states. Further, the network of coupled oscillators follow the same transition route in the entire coupling range. Depending upon distinct coupling ranges, the system displays different number of clusters in the death state and oscillatory state. We also observe that the number of coherent domains in the oscillatory cluster state exponentially decreases with increase in coupling range and obeys a power-law decay. Additionally, we show analytical stability for observed solitary state, synchronized state, and incoherent oscillation death state.

Epitaxial growth of YBa sub 2 Cu sub 3 O sub 7 minus. delta. thin films on LiNbO sub 3 substrates

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Lee, S.G.; Koren, G.; Gupta, A.; Segmuller, A.; Chi, C.C. (IBM Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (US))

1989-09-18

{ital In} {ital situ} epitaxial growth of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thin films on {ital Y}-cut LiNbO{sub 3} substrates using a standard laser ablation technique is reported. Resistance of the films shows a normal metallic behavior and a very sharp ({lt}1 K) superconducting transition with {ital T}{sub {ital c}}({ital R}=0) of 92 K. High critical current density of {ital J}{sub {ital c}}(77 K)=2{times}10{sup 5} A/cm{sup 2} is observed, which is in accordance with epitaxial growth. Film orientation observed from x-ray diffraction spectra indicates that the {ital c} axis is normal to the substrate plane and the {ital a} axis is at 45{degree} to the (11.0) direction of the hexagonal lattice of the substrate with two domains in mirror image to the (110) plane.

Greenhouse impact of CH{sub 4}, N{sub 2}O and CFC emissions in Finland and its control potential

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Pipatti, R.; Savolainen, I.; Sinisalo, J. [VTT Energy, Espoo (Finland)

1995-12-31

Methane (CH{sub 4}), nitrous oxide (N{sub 2}O) and chlorofluorocarbon (CFC) emissions contribute considerably to the anthropogenic enhancement of Earth`s greenhouse effect. The limitation of atmospheric concentrations of CH{sub 4} and N{sub 2}O is considered important also in the Climate Convention. Chlorine released from the CFCs in the stratosphere destroys ozone (O{sub 3}) and the emissions are therefore regulated with the Montreal Protocol. The greenhouse impact of CFCs might be, at least to some extent, compensated by the depletion of O{sub 3} which is also a greenhouse gas. The objective of the presentation is to assess the role of anthropogenic CH{sub 4}, N{sub 2}O, and CFC emissions in the total direct greenhouse impact due to human activities in Finland. The emission estimates for the gases are presented, as well as scenarios for emission history, future development and control potential. The greenhouse impact of the gases is compared with that of carbon dioxide (CO{sub 2}) emissions in Finland. (author)

Greenhouse impact of CH{sub 4}, N{sub 2}O and CFC emissions in Finland and its control potential

Energy Technology Data Exchange (ETDEWEB)

Pipatti, R; Savolainen, I; Sinisalo, J [VTT Energy, Espoo (Finland)

1996-12-31

Methane (CH{sub 4}), nitrous oxide (N{sub 2}O) and chlorofluorocarbon (CFC) emissions contribute considerably to the anthropogenic enhancement of Earth`s greenhouse effect. The limitation of atmospheric concentrations of CH{sub 4} and N{sub 2}O is considered important also in the Climate Convention. Chlorine released from the CFCs in the stratosphere destroys ozone (O{sub 3}) and the emissions are therefore regulated with the Montreal Protocol. The greenhouse impact of CFCs might be, at least to some extent, compensated by the depletion of O{sub 3} which is also a greenhouse gas. The objective of the presentation is to assess the role of anthropogenic CH{sub 4}, N{sub 2}O, and CFC emissions in the total direct greenhouse impact due to human activities in Finland. The emission estimates for the gases are presented, as well as scenarios for emission history, future development and control potential. The greenhouse impact of the gases is compared with that of carbon dioxide (CO{sub 2}) emissions in Finland. (author)

Pentameric ligand-gated ion channels exhibit distinct transmembrane domain archetypes for folding/expression and function.

Science.gov (United States)

Therien, J P Daniel; Baenziger, John E

2017-03-27

Although transmembrane helix-helix interactions must be strong enough to drive folding, they must still permit the inter-helix movements associated with conformational change. Interactions between the outermost M4 and adjacent M1 and M3 α-helices of pentameric ligand-gated ion channels have been implicated in folding and function. Here, we evaluate the role of different physical interactions at this interface in the function of two prokaryotic homologs, GLIC and ELIC. Strikingly, disruption of most interactions in GLIC lead to either a reduction or a complete loss of expression and/or function, while analogous disruptions in ELIC often lead to gains in function. Structural comparisons suggest that GLIC and ELIC represent distinct transmembrane domain archetypes. One archetype, exemplified by GLIC, the glycine and GABA receptors and the glutamate activated chloride channel, has extensive aromatic contacts that govern M4-M1/M3 interactions and that are essential for expression and function. The other archetype, exemplified by ELIC and both the nicotinic acetylcholine and serotonin receptors, has relatively few aromatic contacts that are detrimental to function. These archetypes likely have evolved different mechanisms to balance the need for strong M4 "binding" to M1/M3 to promote folding/expression, and the need for weaker interactions that allow for greater conformational flexibility.

Coherent intergrowth of simple cubic and quintuple tetragonal perovskites in the system Nd{sub 2−ε}Ba{sub 3+ε}(Fe{sub ,}Co){sub 5}O{sub 15−δ}

Energy Technology Data Exchange (ETDEWEB)

Kundu, Asish K. [Laboratoire CRISMAT, ENSICAEN UMR6508, 6 Bd Maréchal Juin, Cedex 4, Caen 14050 (France); Yu Mychinko, Mikhail [Laboratoire CRISMAT, ENSICAEN UMR6508, 6 Bd Maréchal Juin, Cedex 4, Caen 14050 (France); Department of Chemistry, Institute of Natural Sciences, Ural Federal University, Lenin av. 51, Yekaterinburg 620000 (Russian Federation); Caignaert, Vincent; Lebedev, Oleg I. [Laboratoire CRISMAT, ENSICAEN UMR6508, 6 Bd Maréchal Juin, Cedex 4, Caen 14050 (France); Volkova, Nadezhda E.; Deryabina, Ksenia M.; Cherepanov, Vladimir A. [Department of Chemistry, Institute of Natural Sciences, Ural Federal University, Lenin av. 51, Yekaterinburg 620000 (Russian Federation); Raveau, Bernard, E-mail: bernard.raveau@ensicaen.fr [Laboratoire CRISMAT, ENSICAEN UMR6508, 6 Bd Maréchal Juin, Cedex 4, Caen 14050 (France)

2015-11-15

Investigation of the Nd{sub 2−ε}Ba{sub 3+ε}(Fe,Co){sub 5}O{sub 15−δ} system, combining X-ray diffraction and electron microscopy, has allowed a tetragonal quintuple ordered perovskite “a{sub p}×a{sub p}×5a{sub p}” phasoid inter-grown within a single cubic perovskite matrix to be evidenced for ε=0. This nanoscale chemically twinned perovskite is compared with other members, Ln=Sm, Eu, Pr. The unusual long range ordering of the layers develops strains due to size mismatch between Ba{sup 2+} and Ln{sup 3+} cations. Importantly, two factors allow the strains to be decreased: (i) special intergrowths of double (LnBaFe{sub 2}O{sub 6−δ}) and triple (LnBa{sub 2}Fe{sub 3}O{sub 9−δ}) perovskite ribbons/layers oriented at 90°, (ii) nanoscale chemical twinning. The spin locking effect of the nano-domain boundaries upon the magnetic properties of these perovskites is discussed. - Graphical abstract: Nd{sub 2}Ba{sub 3}Fe{sub 5}O{sub 14.54} is a tetragonal quintuple perovskite phasoid embedded in a simple cubic perovskite matrix, which shows collinear antiferromagnetic behavior.

Domain-Specific Control Mechanisms for Emotional and Nonemotional Conflict Processing

Science.gov (United States)

Soutschek, Alexander; Schubert, Torsten

2013-01-01

Recent neuroimaging studies suggest that the human brain activates dissociable cognitive control networks in response to conflicts arising within the cognitive and the affective domain. The present study tested the hypothesis that nonemotional and emotional conflict regulation can also be dissociated on a functional level. For that purpose, we…

Local structure and thermoelectric properties of Mg{sub 2}Si{sub 0.977−x}Ge{sub x}Bi{sub 0.023} (0.1 ⩽ x ⩽ 0.4)

Energy Technology Data Exchange (ETDEWEB)

Farahi, Nader [Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada); Prabhudev, Sagar; Botton, Gianluigi A. [Materials Science and Engineering Department, McMaster University, Hamilton, ON L8S 4L8 (Canada); Zhao, Jianbao; Tse, John S. [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, SK S7N 5E2 (Canada); Liu, Zhenxian [Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015 (United States); Salvador, James R. [General Motors Research & Development Center, Warren, MI 48090 (United States); Kleinke, Holger, E-mail: kleinke@uwaterloo.ca [Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada)

2015-09-25

Highlights: • Incorporating Ge into Bi-doped Mg{sub 2}Si decreases the thermal conductivity and enhances the thermoelectric performance. • Ge-rich domains, identified via TEM, contribute to these changes. • Interstitial sites are in part filled with Mg atoms, as revealed via TEM. • Doping with Bi is advantageous over doping with Sb, resulting in an increase of 48% of the thermoelectric figure of merit. • The highest figure-of-merit of these materials is zT{sub max} = 0.7 at 773 K, realized for Mg{sub 2}Si{sub 0.677}Ge{sub 0.3}Bi{sub 0.023}. - Abstract: We investigated the effect of germanium substitution for silicon in bismuth doped Mg{sub 2}Si. This alloying reduces the thermal conductivity from above 7 W m{sup −1} K{sup −1} to 2.7 W m{sup −1} K{sup −1} at around 300 K in part due to the added mass contrast. High resolution transmission electron microscopy (HRTEM) revealed the presence of Ge-rich domains within the Mg{sub 2}(Si,Ge,Bi) particles, contributing to decreasing thermal conductivity with increasing Ge content up to 0.3 Ge per formula unit. The electrical conductivity also decreases with Ge alloying because of the increasing amount of scattering centers, while the Seebeck coefficient increased only very slightly. In total, the positive effect of Ge substitution on the thermoelectric properties of Bi doped Mg{sub 2}Si resulted in a figure of merit of 0.7 at 773 K for Mg{sub 2}Si{sub 0.677}Ge{sub 0.3}Bi{sub 0.023} sample. The optimum amount of Bi seems to be 0.023 per formula unit (0.77 at%), since lower Bi content resulted in electrical conductivity that is too low, and higher Bi content generated the Mg{sub 3}Bi{sub 2} intermetallic phase.

Phylogenetic analysis of the diacylglycerol kinase family of proteins and identification of multiple highly-specific conserved inserts and deletions within the catalytic domain that are distinctive characteristics of different classes of DGK homologs.

Directory of Open Access Journals (Sweden)

Radhey S Gupta

Full Text Available Diacylglycerol kinase (DGK family of proteins, which phosphorylates diacylglycerol into phosphatidic acid, play important role in controlling diverse cellular processes in eukaryotic organisms. Most vertebrate species contain 10 different DGK isozymes, which are grouped into 5 different classes based on the presence or absence of specific functional domains. However, the relationships among different DGK isozymes or how they have evolved from a common ancestor is unclear. The catalytic domain constitutes the single largest sequence element within the DGK proteins that is commonly and uniquely shared by all family members, but there is limited understanding of the overall function of this domain. In this work, we have used the catalytic domain sequences to construct a phylogenetic tree for the DGK family members from representatives of the main vertebrate classes and have also examined the distributions of various DGK isozymes in eukaryotic phyla. In a tree based on catalytic domain sequences, the DGK homologs belonging to different classes formed strongly supported clusters which were separated by long branches, and the different isozymes within each class also generally formed monophyletic groupings. Further, our analysis of the sequence alignments of catalytic domains has identified >10 novel sequence signatures consisting of conserved signature indels (inserts or deletions, CSIs that are distinctive characteristics of either particular classes of DGK isozymes, or are commonly shared by members of two or more classes of DGK isozymes. The conserved indels in protein sequences are known to play important functional roles in the proteins/organisms where they are found. Thus, our identification of multiple highly specific CSIs that are distinguishing characteristics of different classes of DGK homologs points to the existence of important differences in the catalytic domain function among the DGK isozymes. The identified CSIs in conjunction with

Enhanced dielectric nonlinearity in epitaxial Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub 0.48}O{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Ma, Chunrui, E-mail: chunrui.ma@gmail.com, E-mail: jwu@ku.edu; Wu, Judy, E-mail: chunrui.ma@gmail.com, E-mail: jwu@ku.edu [Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas, 66045 (United States); Ma, Beihai [Energy Systems Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Mi, Shao-Bo [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049 (China); Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Liu, Ming [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049 (China)

2014-04-21

High quality c-axis oriented epitaxial Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub 0.48}O{sub 3} films were fabricated using pulsed laser deposition on (001) LaAlO{sub 3} substrates with conductive LaNiO{sub 3} buffers. Besides confirmation of the in-plane and out-of-plane orientations using X-ray diffraction, transmission electron microscopy study has revealed columnar structure across the film thickness with column width around 100 nm. Characterization of ferroelectric properties was carried out in comparison with polycrystalline Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub 0.48}O{sub 3} films to extract the effect of epitaxial growth. It is found that the ratio between the irreversible Rayleigh parameter and reversible parameter increased up to 0.028 cm/kV at 1 kHz on epitaxial samples, which is more than twice of that on their polycrystalline counterparts. While this ratio decreased to 0.022 cm/kV with increasing frequency to100 kHz, a much less frequency dependence was observed as compared to the polycrystalline case. The epitaxial Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub 0.48}O{sub 3} films exhibited a higher mobility of domain wall and the higher extrinsic contribution to the dielectric properties, as well as reduced density of defects, indicating that it is promising for tunable and low power consumption devices.

Phase characteristics of 0.92Bi{sub 0.5}Na{sub 0.5}TiO{sub 3}-0.08BiAlO{sub 3} ceramics

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Peng, Wei; Mao, Chaoliang; Liu, Zhen; Dong, Xianlin; Cao, Fei; Wang, Genshui, E-mail: genshuiwang@mail.sic.ac.cn [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China)

2015-03-02

The phase characteristics of 0.92Bi{sub 0.5}Na{sub 0.5}TiO{sub 3}-0.08BiAlO{sub 3} lead-free ceramics were investigated systematically. The loss tangent of poled sample shows a broad peak when heating to about 80 °C, i.e., depolarization temperature T{sub d}. The polarization-electric field hysteresis loops at different temperature exhibit the feature of ferroelectric (FE)- antiferroelectric (AFE) phase transition and the co-existence of FE and AFE phase. The pyroelectric coefficients curve confirms its diffusion behaviors. The initial hysteresis loop and switching current curves under T{sub d} indicate the co-existence of FE and AFE phase. The domain morphology of transmission electron microscopy supports the co-existence of FE and AFE phase. Our work not only exhibit that the FE and AFE phase characteristics of 0.92Bi{sub 0.5}Na{sub 0.5}TiO{sub 3}-0.08BiAlO{sub 3} ceramics but also they may be helpful for further investigation on lead-free ceramics.

Improved electrical properties of La{sub 2/3}Ba{sub 1/3}MnO{sub 3}:Ag{sub 0.04} thin films by thermal annealing

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiang; Yin, Xue-Peng; Chen, Qing-Ming; Zhang, Hui; Zhang, Shao-Chun [Kunming University of Science and Technology, Faculty of Material Science and Engineering, Kunming, Yunnan (China)

2014-09-15

La{sub 2/3}Ba{sub 1/3}MnO{sub 3}:Ag{sub 0.04} (LBMO:Ag{sub 0.04}) thin films were prepared on single crystalline (001)-orientated LaAlO{sub 3} substrates by pulsed laser deposition technique. Thermal annealing with temperatures of 780, 800 and 820 C has been investigated to improve electrical properties of the films. All the samples are shown along the (00l) orientation in rhombohedral structure with R anti 3c space group. With thermal annealing temperature increasing, insulator-metal transition temperature (T{sub p}) and resistivity at T{sub p} (ρ{sub T{sub p}}) of the epilayer reach optimal value of 288 K and 0.03 Ω.cm, respectively. The electrical properties improvement of the LBMO:Ag{sub 0.04} films is due to an improved film crystallization, oxygen balance and photon scattering suppression. The fitting curves show that the region of ferro-magnetic metallic (FM, T < T{sub p}) is fitted with grain/domain boundary, electron-electron and magnon scattering mechanism, as well as the region of para-magnetic insulating (PI, T > T{sub p}) is fitted with adiabatic small polaron hopping mechanism. (orig.)

Lateral electric-field control of giant magnetoresistance in Co/Cu/Fe/BaTiO{sub 3} multiferroic heterostructure

Energy Technology Data Exchange (ETDEWEB)

Savitha Pillai, S.; Kojima, H.; Itoh, M.; Taniyama, T., E-mail: taniyama.t.aa@m.titech.ac.jp [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8503 (Japan)

2015-08-17

We report lateral electric-field-driven sizable changes in the magnetoresistance of Co/Cu/Fe tri-layered wires on BaTiO{sub 3} single crystal. While the observed change is marginal in the tetragonal phase of BaTiO{sub 3}, it reaches over 40% in the orthorhombic and rhombohedral phases with an electric field of 66 kV/cm. We attribute it to possible electric-field-induced variations of the spin-dependent electronic structures, i.e., spin polarization, of the Fe via interfacial strain transfer from BaTiO{sub 3}. The contrasting results for the different phases of BaTiO{sub 3} are discussed, associated with the distinct aspects of the ferroelectric polarization switching processes in each phase.

Study on the electrical transport properties of La{sub 2/3}Ba{sub 1/3}MnO{sub 3}:Ag{sub 0.04}/LaAlO{sub 3} (001) films

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiang, E-mail: lxjim@126.com; Zhao, Shuang; Zhang, Shao-Chun

2017-01-01

La{sub 2/3}Ba{sub 1/3}MnO{sub 3}: wt%Ag{sub x} (LBMO:Ag{sub x}, x=0.04) films were prepared on single crystalline (001)-orientated LaAlO{sub 3} substrates by pulsed laser deposition technique. All the samples show along the (00l) orientation in rhombohedral structure with R3c space group. The surface roughness (Ra), insulator-metal transition temperature (Tp) and resistivity at Tp (ρ{sub Tp}) of the LBMO:Ag{sub 0.04} films reached optimal values of 3.29 nm, 288 K and 0.033 Ω cm at 740 °C, respectively. The improvement of electrical transport properties in the films are attributed to the optimal growth temperature and Ag-doping improve the microstructure of the surfaces, grain boundaries (GBs) in connectivity and better crystallization. In addition, the electrical conduction behaviors can be well fitted with the grain/domain boundary, electron–electron and magnon scattering mechanisms in the ferromagnetic metallic region (TTp).

Edaphic factors controlling summer (rainy season) greenhouse gas emissions (CO{sub 2} and CH{sub 4}) from semiarid mangrove soils (NE-Brazil)

Energy Technology Data Exchange (ETDEWEB)

Nóbrega, Gabriel N. [Departamento de Ciência do Solo, Escola Superior de Agricultura Luiz de Queiroz, ESALQ/USP, Av.Pádua Dias 11, Piracicaba, São Paulo 13.418-260 (Brazil); Ferreira, Tiago O., E-mail: toferreira@usp.br [Departamento de Ciência do Solo, Escola Superior de Agricultura Luiz de Queiroz, ESALQ/USP, Av.Pádua Dias 11, Piracicaba, São Paulo 13.418-260 (Brazil); Siqueira Neto, M. [Laboratório de Biogeoquímica Ambiental, Centro de Energia Nuclear na Agricultura, CENA/USP, Av. Centenário 303, Piracicaba, São Paulo 13.400-970 (Brazil); Queiroz, Hermano M.; Artur, Adriana G. [Departamento de Ciências do Solo, Universidade Federal do Ceará, UFC, Av. Mister Hull 2977, Campus do Pici, Fortaleza, Ceará 60.440-554 (Brazil); Mendonça, Eduardo De S. [Departamento de Produção Vegetal, Universidade Federal do Espírito Santo, UFES, Alto Universitário s/n, Alegre, Espírito Santo 29.500-000 (Brazil); Silva, Ebenezer De O. [Empresa Brasileira de Pesquisa Agropecuária, Centro Nacional de Pesquisa de Agroindústria Tropical, Pós Colheita, Dra. Sara Mesquita Street, 2270, Planalto Pici, Fortaleza, Ceará 60.511-110 (Brazil); and others

2016-01-15

The soil attributes controlling the CO{sub 2}, and CH{sub 4} emissions were assessed in semiarid mangrove soils (NE-Brazil) under different anthropogenic activities. Soil samples were collected from different mangroves under different anthropogenic impacts, e.g., shrimp farming (Jaguaribe River); urban wastes (Cocó River) and a control site (Timonha River). The sites were characterized according to the sand content; physicochemical parameters (Eh and pH); total organic C; soil C stock (SCS) and equivalent SCS (SCS{sub EQV}); total P and N; dissolved organic C (DOC); and the degree of pyritization (DOP). The CO{sub 2} and CH{sub 4} fluxes from the soils were assessed using static closed chambers. Higher DOC and SCS and the lowest DOP promote greater CO{sub 2} emission. The CH{sub 4} flux was only observed at Jaguaribe which presented higher DOP, compared to that found in mangroves from humid tropical climates. Semiarid mangrove soils cannot be characterized as important greenhouse gas sources, compared to humid tropical mangroves. - Highlights: • GHG emission was associated with different soil characteristics. • Highest CO{sub 2} emissions were found in mangroves with larger dissolved C and lower DOP. • Less CH{sub 4} flux was due to low DOP in semiarid mangrove soils.

Voltage-controlled ferromagnetism and magnetoresistance in LaCoO{sub 3}/SrTiO{sub 3} heterostructures

Energy Technology Data Exchange (ETDEWEB)

Hu, Chengqing; Park, Keun Woo; Yu, Edward T. [Microelectronics Research Center, The University of Texas at Austin, 10100 Burnet Rd., Austin, Texas 78758 (United States); Posadas, Agham; Demkov, Alexander A. [Department of Physics, The University of Texas at Austin, 1 University Station C1600, Austin, Texas 78712 (United States); Jordan-Sweet, Jean L. [IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598 (United States)

2013-11-14

A LaCoO{sub 3}/SrTiO{sub 3} heterostructure grown on Si (001) is shown to provide electrically switchable ferromagnetism, a large, electrically tunable magnetoresistance, and a vehicle for achieving and probing electrical control over ferromagnetic behavior at submicron dimensions. Fabrication of devices in a field-effect transistor geometry enables application of a gate bias voltage that modulates strain in the heterostructure via the converse piezoelectric effect in SrTiO{sub 3}, leading to an artificial inverse magnetoelectric effect arising from the dependence of ferromagnetism in the LaCoO{sub 3} layer on strain. Below the Curie temperature of the LaCoO{sub 3} layer, this effect leads to modulation of resistance in LaCoO{sub 3} as large as 100%, and magnetoresistance as high as 80%, both of which arise from carrier scattering at ferromagnetic-nonmagnetic interfaces in LaCoO{sub 3}. Finite-element numerical modeling of electric field distributions is used to explain the dependence of carrier transport behavior on gate contact geometry, and a Valet-Fert transport model enables determination of spin polarization in the LaCoO{sub 3} layer. Piezoresponse force microscopy is used to confirm the existence of piezoelectric response in SrTiO{sub 3} grown on Si (001). It is also shown that this structure offers the possibility of achieving exclusive-NOR logic functionality within a single device.

Arabidopsis Microtubule-Associated Protein MAP65-3 Cross-Links Antiparallel Microtubules toward Their Plus Ends in the Phragmoplast via Its Distinct C-Terminal Microtubule Binding Domain[W

Science.gov (United States)

Ho, Chin-Min Kimmy; Lee, Yuh-Ru Julie; Kiyama, Lindsay D.; Dinesh-Kumar, Savithramma P.; Liu, Bo

2012-01-01

Plant cytokinesis is brought about by the phragmoplast, which contains an antiparallel microtubule (MT) array. The MT-associated protein MAP65-3 acts as an MT-bundling factor that specifically cross-links antiparallel MTs near their plus ends. MAP65 family proteins contain an N-terminal dimerization domain and C-terminal MT interaction domain. Compared with other MAP65 isoforms, MAP65-3 contains an extended C terminus. A MT binding site was discovered in the region between amino acids 496 and 588 and found to be essential for the organization of phragmoplast MTs. The frequent cytokinetic failure caused by loss of MAP65-3 was not rescued by ectopic expression of MAP65-1 under the control of the MAP65-3 promoter, indicating nonoverlapping functions between the two isoforms. In the presence of MAP65-3, however, ectopic MAP65-1 appeared in the phragmoplast midline. We show that MAP65-1 could acquire the function of MAP65-3 when the C terminus of MAP65-3, which contains the MT binding site, was grafted to it. Our results also show that MAP65-1 and MAP65-3 may share redundant functions in MT stabilization. Such a stabilization effect was likely brought about by MT binding and bundling. We conclude that MAP65-3 contains a distinct C-terminal MT binding site with a specific role in cross-linking antiparallel MTs toward their plus ends in the phragmoplast. PMID:22570443

Control of the Shell Thickness of TiO{sub 2} SiO{sub 2} Particles and Its Surface Functionalization

Energy Technology Data Exchange (ETDEWEB)

Ahn, Junho; Jung, Sung Ho; Lee, Ji Ha; Kwon, Kiyoung; Jung, Jong Hwa [Gyeongsang National Univ., Jinju (Korea, Republic of)

2013-11-15

TiO{sub 2} SiO{sub 2} yolk/core shell particles were obtained by a sol-gel polymerization. The shell thickness of TiO{sub 2} SiO{sub 2} can successfully be controlled by sol-gel reaction times. The anatase structure of TiO{sub 2} SiO{sub 2} was more stable than that of TiO{sub 2} particles calcinated at higher temperature. Moreover, acrylate-functionalized TiO{sub 2} SiO{sub 2} particles were also successfully synthesized using the TiO{sub 2} SiO{sub 2} particles as building blocks by copolymerization of trimethoxysilyl groups of MPA with the existing hydroxyl groups on the surface of TiO{sub 2} SiO{sub 2} particles. Furthermore, TEM, EDX, and FTIR studies confirmed that MPA had been successfully grafted to the surface of TiO{sub 2} SiO{sub 2} particles. Finally, we believe that the present results showing the development of surface functionalized particles can be very useful in the fields of various functional applications, and could be extended to more sophisticated hybrid materials.The fabrication of functional hollow particles is of great scientific and technological interest for purposes of applications ranging from drug delivery, coatings, photonic devices, and nanoscale reaction vessels. Various methods, including approaches such as spray drying, emulsion templating techniques, and self-assembly processes, have been described for the preparation of hollow spheres out of latex, metal, and inorganic materials.

Improved flux-pinning properties of REBa{sub 2}Cu{sub 3}O{sub 7-z} films by low-level Co doping

Energy Technology Data Exchange (ETDEWEB)

Wang, Wentao; Pu, Minghua; Wang, Weiwei; Lei, Ming [Key Laboratory of Magnetic Levitation and Maglev Trains, Ministry of Education of China, Superconductivity R and D Centre (SRDC), Southwest Jiaotong University, Erhuanlu Beiyiduan 111, 610031 Chengdu (China); Cheng, Cuihua [Superconductivity Research Group, School of Materials Science and Engineering, University of New South Wales, 2052 NSW, Sydney (Australia); Zhao, Yong [Key Laboratory of Magnetic Levitation and Maglev Trains, Ministry of Education of China, Superconductivity R and D Centre (SRDC), Southwest Jiaotong University, Erhuanlu Beiyiduan 111, 610031 Chengdu (China); Superconductivity Research Group, School of Materials Science and Engineering, University of New South Wales, 2052 NSW, Sydney (Australia)

2011-09-15

Biaxially textured REBa{sub 2}Cu{sub 3-x}Co{sub x}O{sub 7-z} (RE = Gd,Y) films were prepared on (00l) LaAlO{sub 3} substrate using self-developed fluorine-free chemical solution deposition (CSD) approach. The in-field J{sub c} values are significantly improved for REBa{sub 2}Cu{sub 3-x}Co{sub x}O{sub 7-z} films through low-level Co doping. Co-doped GdBa{sub 2}Cu{sub 3}O{sub 7-z} film shows the highest J{sub c} values at higher temperatures and fields, whereas the J{sub c} values of Co-doped YBa{sub 2}Cu{sub 3}O{sub 7-z} film surpass that of other films at lower temperatures and fields. In addition, the volume pinning force densities of films with Co doping have been distinctly enhanced in the applied fields, indicating improved flux-pinning properties. The possible reasons are discussed in detail. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Domain decomposition methods for the mixed dual formulation of the critical neutron diffusion problem; Methodes de decomposition de domaine pour la formulation mixte duale du probleme critique de la diffusion des neutrons

Energy Technology Data Exchange (ETDEWEB)

Guerin, P

2007-12-15

The neutronic simulation of a nuclear reactor core is performed using the neutron transport equation, and leads to an eigenvalue problem in the steady-state case. Among the deterministic resolution methods, diffusion approximation is often used. For this problem, the MINOS solver based on a mixed dual finite element method has shown his efficiency. In order to take advantage of parallel computers, and to reduce the computing time and the local memory requirement, we propose in this dissertation two domain decomposition methods for the resolution of the mixed dual form of the eigenvalue neutron diffusion problem. The first approach is a component mode synthesis method on overlapping sub-domains. Several Eigenmodes solutions of a local problem solved by MINOS on each sub-domain are taken as basis functions used for the resolution of the global problem on the whole domain. The second approach is a modified iterative Schwarz algorithm based on non-overlapping domain decomposition with Robin interface conditions. At each iteration, the problem is solved on each sub domain by MINOS with the interface conditions deduced from the solutions on the adjacent sub-domains at the previous iteration. The iterations allow the simultaneous convergence of the domain decomposition and the eigenvalue problem. We demonstrate the accuracy and the efficiency in parallel of these two methods with numerical results for the diffusion model on realistic 2- and 3-dimensional cores. (author)

Diverse Supramolecular Nanofiber Networks Assembled by Functional Low-Complexity Domains.

Science.gov (United States)

An, Bolin; Wang, Xinyu; Cui, Mengkui; Gui, Xinrui; Mao, Xiuhai; Liu, Yan; Li, Ke; Chu, Cenfeng; Pu, Jiahua; Ren, Susu; Wang, Yanyi; Zhong, Guisheng; Lu, Timothy K; Liu, Cong; Zhong, Chao

2017-07-25

Self-assembling supramolecular nanofibers, common in the natural world, are of fundamental interest and technical importance to both nanotechnology and materials science. Despite important advances, synthetic nanofibers still lack the structural and functional diversity of biological molecules, and the controlled assembly of one type of molecule into a variety of fibrous structures with wide-ranging functional attributes remains challenging. Here, we harness the low-complexity (LC) sequence domain of fused in sarcoma (FUS) protein, an essential cellular nuclear protein with slow kinetics of amyloid fiber assembly, to construct random copolymer-like, multiblock, and self-sorted supramolecular fibrous networks with distinct structural features and fluorescent functionalities. We demonstrate the utilities of these networks in the templated, spatially controlled assembly of ligand-decorated gold nanoparticles, quantum dots, nanorods, DNA origami, and hybrid structures. Owing to the distinguishable nanoarchitectures of these nanofibers, this assembly is structure-dependent. By coupling a modular genetic strategy with kinetically controlled complex supramolecular self-assembly, we demonstrate that a single type of protein molecule can be used to engineer diverse one-dimensional supramolecular nanostructures with distinct functionalities.

Virus-Induced Chaperone-Enriched (VICE domains function as nuclear protein quality control centers during HSV-1 infection.

Directory of Open Access Journals (Sweden)

Christine M Livingston

2009-10-01

Full Text Available Virus-Induced Chaperone-Enriched (VICE domains form adjacent to nuclear viral replication compartments (RC during the early stages of HSV-1 infection. Between 2 and 3 hours post infection at a MOI of 10, host protein quality control machinery such as molecular chaperones (e.g. Hsc70, the 20S proteasome and ubiquitin are reorganized from a diffuse nuclear distribution pattern to sequestration in VICE domains. The observation that VICE domains contain putative misfolded proteins suggests that they may be similar to nuclear inclusion bodies that form under conditions in which the protein quality control machinery is overwhelmed by the presence of misfolded proteins. The detection of Hsc70 in VICE domains, but not in nuclear inclusion bodies, indicates that Hsc70 is specifically reorganized by HSV-1 infection. We hypothesize that HSV-1 infection induces the formation of nuclear protein quality control centers to remodel or degrade aberrant nuclear proteins that would otherwise interfere with productive infection. Detection of proteolytic activity in VICE domains suggests that substrates may be degraded by the 20S proteasome in VICE domains. FRAP analysis reveals that GFP-Hsc70 is dynamically associated with VICE domains, suggesting a role for Hsc70 in scanning the infected nucleus for misfolded proteins. During 42 degrees C heat shock, Hsc70 is redistributed from VICE domains into RC perhaps to remodel viral replication and regulatory proteins that have become insoluble in these compartments. The experiments presented in this paper suggest that VICE domains are nuclear protein quality control centers that are modified by HSV-1 to promote productive infection.

Two actinide-organic frameworks constructed by a tripodal flexible ligand: Occurrence of infinite ((UO{sub 2})O{sub 2}(OH){sub 3}){sub 4n} and hexanuclear (Th{sub 6}O{sub 4}(OH){sub 4}) motifs

Energy Technology Data Exchange (ETDEWEB)

Liang, Lingling; Zhang, Ronglan [College of Chemistry and Materials, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of education, Northwest University, Xi’an 710069 (China); Zhao, Jianshe, E-mail: jszhao@nwu.edu.cn [College of Chemistry and Materials, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of education, Northwest University, Xi’an 710069 (China); Liu, Chiyang, E-mail: lcy@nwu.edu.cn [Department of Geology, Northwest University, Xi’an 710069 (China); Weng, Ng Seik [The University of Nottingham Malaysia Campus, 43500 Semenyih, Selangor Darul Ehsan (Malaysia)

2016-11-15

Two new actinide metal-organic frameworks were constructed by using a tripodal flexible ligand tris (2-carboxyethyl) isocyanurate (H{sub 3}tci) under hydrothermal condition. The combination of H{sub 3}tci and uranyl nitrate hexahydrate in aqueous solution leads to the isolation of [(UO{sub 2}){sub 2}(H{sub 2}O){sub 4}]{sub 0.5}(tci){sub 2}(UO{sub 2}){sub 4}(OH){sub 4}·18H{sub 2}O (1), which contains two distinct UO{sub 2}{sup 2+} coordination environments. Four uranyl cations, linked through μ{sub 3}-OH respectively, result in the edge-sharing ribbons. Then, the layer structure is constructed by U-O clusters linked through other eight-coordinated uranyl unions, giving rise to a porous structure in the space. Topological analysis reveals that complex 1 belongs to a (4, 8)-connected net with a schläfli symbol of (3{sup 4.}2{sup 6.}3){sub 2}(3{sup 4.}4{sup 6.}5{sup 6.}6{sup 8.}7{sup 3.}8). Th{sub 3}(tci){sub 2}O{sub 2}(OH){sub 2}(H{sub 2}O){sub 3}·12H{sub 2}O (2) generated by the reaction of H{sub 3}tci and thorium nitrate tetrahydrate, possesses nine-fold coodinated Th(IV) centers with a monocapped square antiprismatic geometry. The hexamers “Th{sub 6}O{sub 4}(OH){sub 4}” motifs are connected together by the carboxylate groups, showing a three-dimensional structures. Complex 2 takes on an 8-connected architecture and the point symbol is (4{sup 24.}6{sup 4}). - Graphical abstract: Two new 3D actinide metal-organic frameworks were constructed by using a tripodal flexible ligand tris (2-carboxyethyl) isocyanurate (H3tci) and their topological structures were displayed. The infinite ((UO{sub 2})O{sub 2}(OH){sub 3}){sub 4n} and hexanuclear (Th{sub 6}O{sub 4}(OH){sub 4}) motifs were found in the title actinides networks.