WorldWideScience

Sample records for electric field-induced direct

  1. Electric field-induced astrocyte alignment directs neurite outgrowth.

    Science.gov (United States)

    Alexander, John K; Fuss, Babette; Colello, Raymond J

    2006-05-01

    The extension and directionality of neurite outgrowth are key to achieving successful target connections during both CNS development and during the re-establishment of connections lost after neural trauma. The degree of axonal elongation depends, in large part, on the spatial arrangement of astrocytic processes rich in growth-promoting proteins. Because astrocytes in culture align their processes on exposure to an electrical field of physiological strength, we sought to determine the extent to which aligned astrocytes affect neurite outgrowth. To this end, dorsal root ganglia cells were seeded onto cultured rat astrocytes that were pre-aligned by exposure to an electric field of physiological strength (500 mV mm(-1)). Using confocal microscopy and digital image analysis, we found that neurite outgrowth at 24 hours and at 48 hours is enhanced significantly and directed consistently along the aligned astrocyte processes. Moreover, this directed neurite outgrowth is maintained when grown on fixed, aligned astrocytes. Collectively, these results indicate that endogenous electric fields present within the developing CNS might act to align astrocyte processes, which can promote and direct neurite growth. Furthermore, these results demonstrate a simple method to produce an aligned cellular substrate, which might be used to direct regenerating neurites.

  2. Electric field-induced astrocyte alignment directs neurite outgrowth

    OpenAIRE

    ALEXANDER, JOHN K.; FUSS, BABETTE; COLELLO, RAYMOND J.

    2006-01-01

    The extension and directionality of neurite outgrowth are key to achieving successful target connections during both CNS development and during the re-establishment of connections lost after neural trauma. The degree of axonal elongation depends, in large part, on the spatial arrangement of astrocytic processes rich in growth-promoting proteins. Because astrocytes in culture align their processes on exposure to an electrical field of physiological strength, we sought to determine the extent t...

  3. Electric-field Induced Microdynamics of Charged Rods

    Directory of Open Access Journals (Sweden)

    Kyongok eKang

    2014-12-01

    Full Text Available Electric-field induced phase/state transitions are observed in AC electric fields with small amplitudes and low frequencies in suspensions of charged fibrous viruses (fd, which are model systems for highly charged rod-like colloids. Texture- and particle-dynamics in these field-induced states, and on crossing transition lines, are explored by image time-correlation and dynamic light scattering, respectively. At relatively low frequencies, starting from a system within the isotropic-nematic coexistence region, a transition from a nematic to a chiral nematic is observed, as well as a dynamical state where nematic domains melt and reform. These transitions are preliminary due to field-induced dissociation/association of condensed ions. At higher frequencies a uniform state is formed that is stabilized by hydrodynamic interactions through field-induced electro-osmotic flow where the rods align along the field direction. There is a point in the field-amplitude versus frequency plane where various transition lines meet. This point can be identified as a non-equilibrium critical point, in the sense that a length scale and a time scale diverge on approach of that point. The microscopic dynamics exhibits discontinuities on crossing transition lines that were identified independently by means of image and signal correlation spectroscopy.

  4. Field-Induced Superconductivity in Electric Double Layer Transistors

    NARCIS (Netherlands)

    Ueno, Kazunori; Shimotani, Hidekazu; Yuan, Hongtao; Ye, Jianting; Kawasaki, Masashi; Iwasa, Yoshihiro

    Electric field tuning of superconductivity has been a long-standing issue in solid state physics since the invention of the field-effect transistor (FET) in 1960. Owing to limited available carrier density in conventional FET devices, electric-field-induced superconductivity was believed to be

  5. Electric field induced instabilities in free emulsion films

    Energy Technology Data Exchange (ETDEWEB)

    Tchoukov, P.; Dabros, T. [Natural Resources Canada, Devon, AB (Canada); Mostowfi, F. [Schlumberger DBR Technology Center, Edmonton, AB (Canada); Panchev, N. [Champion Technologies Inc., Houston, TX (United States); Czarnecki, J. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

    2009-07-01

    This presentation reported on a study that investigated the mechanism of electric field-induced breakdown of free emulsion films. Instability patterns were observed on the plane of a water-oil-water film following electric polarization. The length-scales of the instabilities were measured by analyzing images immediately after applying the electric field. Linear stability analysis was used to calculate the theoretical dominant wavelengths. The calculated values were found to be in good agreement with measured values. The films were formed in a thin film apparatus modified so that the oil film separated 2 aqueous phase compartments, each in contact with a platinum electrode. This enabled the measurement of disjoining pressure while applying the electric field to the film. It was concluded that breakdown of thin films induced by electric field has many applications, including electrostatic de-emulsification/desalination of crude oil and emulsion stability measurements. It was concluded that electroporation and dielectric breakdown may be responsible for electric field-induced breakdown. This study also presented evidence of an increase in electric field-induced instabilities in emulsion films resulting in rupture. tabs., figs.

  6. Spatiotemporal structure of intracranial electric fields induced by transcranial electric stimulation in humans and nonhuman primates

    DEFF Research Database (Denmark)

    Opitz, Alexander; Falchier, Arnaud; Yan, Chao-Gan

    2016-01-01

    Transcranial electric stimulation (TES) is an emerging technique, developed to non-invasively modulate brain function. However, the spatiotemporal distribution of the intracranial electric fields induced by TES remains poorly understood. In particular, it is unclear how much current actually reac...

  7. Electric-field-induced superconductivity detected by magnetization measurements of an electric-double-layer capacitor

    International Nuclear Information System (INIS)

    Kasahara, Yuichi; Takeuchi, Yuki; Ye, Jianting; Yuan, Hongtao; Shimotani, Hidekazu; Iwasa, Yoshihiro; Nishimura, Takahiro; Sato, Tatsuya

    2010-01-01

    We report evidence for superconductivity induced by the application of strong electric fields onto the surface of a band insulator, ZrNCl, provided by the observation of a shielding diamagnetic signal. We introduced an electric-double-layer capacitor configuration and in situ magnetization measurements at low temperatures as a method to detect the novel electric-field-induced superconducting state. The results showed excellent agreement with a previous report using a transistor configuration, demonstrating that the present technique is a novel method for investigating the nonequilibrium phase induced by electric fields. (author)

  8. Effects of coil orientation on the electric field induced by TMS over the hand motor area

    International Nuclear Information System (INIS)

    Laakso, Ilkka; Hirata, Akimasa; Ugawa, Yoshikazu

    2014-01-01

    Responses elicited by transcranial magnetic stimulation (TMS) over the hand motor area depend on the position and orientation of the stimulating coil. In this work, we computationally investigate the induced electric field for multiple coil orientations and locations in order to determine which parts of the brain are affected and how the sensitivity of motor cortical activation depends on the direction of the electric field. The finite element method is used for calculating the electric field induced by TMS in two individual anatomical models of the head and brain. The orientation of the coil affects both the strength and depth of penetration of the electric field, and the field strongly depends on the direction of the sulcus, where the target neurons are located. The coil position that gives the strongest electric field in the target cortical region may deviate from the closest scalp location by a distance on the order of 1 cm. Together with previous experimental data, the results support the hypothesis that the cortex is most sensitive to fields oriented perpendicular to the cortical layers, while it is relatively insensitive to fields parallel to them. This has important implications for targeting of TMS. To determine the most effective coil position and orientation, it is essential to consider both biological (the direction of the targeted axons) and physical factors (the strength and direction of the electric field). (paper)

  9. Electric Field Induced Strain in Electrostrictive Polymers Under High Hydrostatic Pressure - System Development and Material Characterization

    National Research Council Canada - National Science Library

    Zhang, Q

    2000-01-01

    ... of (i) developing a high performance piezo-bimorph based dilatometer which can be used to characterize the electric field induced strain response in polymer films under high hydrostatic pressure, (ii...

  10. Electric field induced dewetting at polymer/polymer interfaces

    NARCIS (Netherlands)

    Lin, Z.Q.; Kerle, T.; Russell, T.P.; Schäffer, E.; Steiner, U

    2002-01-01

    External electric fields were used to amplify interfacial fluctuations in the air/polymer/polymer system where one polymer dewets the other. Two different hydrodynamic regimes were found as a function of electric field strength. If heterogeneous nucleation leads to the formation of holes before the

  11. Electric-field-induced paraelectric to ferroelectric phase transformation in prototypical polycrystalline BaTiO3

    International Nuclear Information System (INIS)

    Wang, Zhiyang; Hinterstein, Manuel; Daniels, John E.; Webber, Kyle G.; Hudspeth, Jessica M.

    2014-01-01

    An electric-field-induced paraelectric cubic to ferroelectric tetragonal phase transformation has been directly observed in prototypical polycrystalline BaTiO 3 at temperatures above the Curie point (T C ) using in situ high-energy synchrotron X-ray diffraction. The transformation persisted to a maximum temperature of 4 °C above T C . The nature of the observed field-induced transformation and the resulting development of domain texture within the induced phase were dependent on the proximity to the transition temperature, corresponding well to previous macroscopic measurements. The transition electric field increased with increasing temperature above T C , while the magnitude of the resultant tetragonal domain texture at the maximum electric field (4 kV mm −1 ) decreased at higher temperatures. These results provide insights into the phase transformation behavior of a prototypical ferroelectric and have important implications for the development of future large-strain phase-change actuator materials.

  12. Control of magnetic relaxation by electric-field-induced ferroelectric phase transition and inhomogeneous domain switching

    Energy Technology Data Exchange (ETDEWEB)

    Nan, Tianxiang; Emori, Satoru; Wang, Xinjun; Hu, Zhongqiang; Xie, Li; Gao, Yuan; Lin, Hwaider; Sun, Nian, E-mail: n.sun@neu.edu [Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts 02115 (United States); Peng, Bin; Liu, Ming, E-mail: mingliu@mail.xjtu.edu.cn [Electronic Materials Research Laboratory, Xi' an Jiaotong University, Xi' an 710049 (China); Jiao, Jie; Luo, Haosu [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800 (China); Budil, David [Department of Chemistry, Northeastern University, Boston, Massachusetts 02115 (United States); Jones, John G.; Howe, Brandon M.; Brown, Gail J. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States)

    2016-01-04

    Electric-field modulation of magnetism in strain-mediated multiferroic heterostructures is considered a promising scheme for enabling memory and magnetic microwave devices with ultralow power consumption. However, it is not well understood how electric-field-induced strain influences magnetic relaxation, an important physical process for device applications. Here, we investigate resonant magnetization dynamics in ferromagnet/ferroelectric multiferroic heterostructures, FeGaB/PMN-PT and NiFe/PMN-PT, in two distinct strain states provided by electric-field-induced ferroelectric phase transition. The strain not only modifies magnetic anisotropy but also magnetic relaxation. In FeGaB/PMN-PT, we observe a nearly two-fold change in intrinsic Gilbert damping by electric field, which is attributed to strain-induced tuning of spin-orbit coupling. By contrast, a small but measurable change in extrinsic linewidth broadening is attributed to inhomogeneous ferroelastic domain switching during the phase transition of the PMN-PT substrate.

  13. Electric-field-induced magnetic domain writing in a Co wire

    Science.gov (United States)

    Tanaka, Yuki; Hirai, Takamasa; Koyama, Tomohiro; Chiba, Daichi

    2018-05-01

    We have demonstrated that the local magnetization in a Co microwire can be switched by an application of a gate voltage without using any external magnetic fields. The electric-field-induced reversible ferromagnetic phase transition was used to realize this. An internal stray field from a ferromagnetic gate electrode assisted the local domain reversal in the Co wire. This new concept of electrical domain switching may be useful for dramatically reducing the power consumption of writing information in a magnetic racetrack memory, in which a shift of a magnetic domain by electric current is utilized.

  14. Electric-field-induced monoclinic phase in (Ba,Sr)TiO3 thin film

    International Nuclear Information System (INIS)

    Anokhin, A. S.; Yuzyuk, Yu. I.; Golovko, Yu. I.; Mukhortov, V. M.; El Marssi, M.

    2011-01-01

    We have studied electric-field-induced symmetry lowering in the tetragonal (001)-oriented heteroepitaxial (Ba 0.8 Sr 0.2 )TiO 3 thin film deposited on (001)MgO substrate. Polarized micro-Raman spectra were recorded from the film area in between two planar electrodes deposited on the film surface. Presence of c domains with polarization normal to the substrate was confirmed from polarized Raman study under zero field, while splitting and hardening of the E(TO) soft mode and polarization changes in the Raman spectra suggest monoclinic symmetry under external electric field.

  15. The giant piezoelectric effect: electric field induced monoclinic phase or piezoelectric distortion of the rhombohedral parent?

    International Nuclear Information System (INIS)

    Kisi, E H; Piltz, R O; Forrester, J S; Howard, C J

    2003-01-01

    Lead zinc niobate-lead titanate (PZN-PT) single crystals show very large piezoelectric strains for electric fields applied along the unit cell edges e.g. [001] R . It has been widely reported that this effect is caused by an electric field induced phase transition from rhombohedral (R3m) to monoclinic (Cm or Pm) symmetry in an essentially continuous manner. Group theoretical analysis using the computer program ISOTROPY indicates phase transitions between R3m and Cm (or Pm) must be discontinuous under Landau theory. An analysis of the symmetry of a strained unit cell in R3m and a simple expansion of the piezoelectric strain equation indicate that the piezoelectric distortion due to an electric field along a cell edge in rhombohedral perovskite-based ferroelectrics is intrinsically monoclinic (Cm), even for infinitesimal electric fields. PZN-PT crystals have up to nine times the elastic compliance of other piezoelectric perovskites and it might be expected that the piezoelectric strains are also very large. A field induced phase transition is therefore indistinguishable from the piezoelectric distortion and is neither sufficient nor necessary to understand the large piezoelectric response of PZN-PT

  16. Strain- and electric field-induced band gap modulation in nitride nanomembranes

    International Nuclear Information System (INIS)

    Amorim, Rodrigo G; Zhong Xiaoliang; Mukhopadhyay, Saikat; Pandey, Ravindra; Rocha, Alexandre R; Karna, Shashi P

    2013-01-01

    The hexagonal nanomembranes of the group III-nitrides are a subject of interest due to their novel technological applications. In this paper, we investigate the strain- and electric field-induced modulation of their band gaps in the framework of density functional theory. For AlN, the field-dependent modulation of the bandgap is found to be significant whereas the strain-induced semiconductor-metal transition is predicted for GaN. A relatively flat conduction band in AlN and GaN nanomembranes leads to an enhancement of their electronic mobility compared to that of their bulk counterparts. (paper)

  17. Electric field induced localization phenomena in a ladder network with superlattice configuration: Effect of backbone environment

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Paramita; Karmakar, S. N. [Condensed Matter Physics Division, Saha Institute of Nuclear Physics, Sector-I, Block-AF, Bidhannagar, Kolkata-700 064 (India); Maiti, Santanu K., E-mail: santanu.maiti@isical.ac.in [Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata-700 108 (India)

    2014-09-15

    Electric field induced localization properties of a tight-binding ladder network in presence of backbone sites are investigated. Based on Green's function formalism we numerically calculate two-terminal transport together with density of states for different arrangements of atomic sites in the ladder and its backbone. Our results lead to a possibility of getting multiple mobility edges which essentially plays a switching action between a completely opaque to fully or partly conducting region upon the variation of system Fermi energy, and thus, support in fabricating mesoscopic or DNA-based switching devices.

  18. In situ transmission electron microscopy study of the microstructural origins for the electric field-induced phenomena in ferroelectric perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Hanzheng [Iowa State Univ., Ames, IA (United States)

    2014-12-15

    Ferroelectrics are important materials due to their extensive technological applications, such as non-volatile memories, field-effect transistors, ferroelectric tunneling junctions, dielectric capacitors, piezoelectric transducers, sensors and actuators. As is well known, the outstanding dielectric, piezoelectric, and ferroelectric properties of these functional oxides originate from their ferroelectric domain arrangements and the corresponding evolution under external stimuli (e.g. electric field, stress, and temperature). Electric field has been known as the most efficient stimulus to manipulate the ferroelectric domains through polarization switching and alignment. Therefore, direct observation of the dynamic process of electric field-induced domain evolution and crystal structure transformation is of significant importance to understand the microstructural mechanisms for the functional properties of ferroelectrics. In this dissertation, electric field in situ transmission electron microscopy (TEM) technique was employed to monitor the real-time evolution of the domain morphology and crystal structure during various electrical processes: (1) the initial poling process, (2) the electric field reversal process, and (3) the electrical cycling process. Two types of perovskite-structured ceramics, normal ferroelectrics and relaxor ferroelectrics, were used for this investigation. In addition to providing the microscopic insight for some wellaccepted phase transformation rules, discoveries of some new or even unexpected physical phenomena were also demonstrated.

  19. Pair-breaking effects by parallel magnetic field in electric-field-induced surface superconductivity

    International Nuclear Information System (INIS)

    Nabeta, Masahiro; Tanaka, Kenta K.; Onari, Seiichiro; Ichioka, Masanori

    2016-01-01

    Highlights: • Zeeman effect shifts superconducting gaps of sub-band system, towards pair-breaking. • Higher-level sub-bands become normal-state-like electronic states by magnetic fields. • Magnetic field dependence of zero-energy DOS reflects multi-gap superconductivity. - Abstract: We study paramagnetic pair-breaking in electric-field-induced surface superconductivity, when magnetic field is applied parallel to the surface. The calculation is performed by Bogoliubov-de Gennes theory with s-wave pairing, including the screening effect of electric fields by the induced carriers near the surface. Due to the Zeeman shift by applied fields, electronic states at higher-level sub-bands become normal-state-like. Therefore, the magnetic field dependence of Fermi-energy density of states reflects the multi-gap structure in the surface superconductivity.

  20. Picosecond Electric-Field-Induced Threshold Switching in Phase-Change Materials.

    Science.gov (United States)

    Zalden, Peter; Shu, Michael J; Chen, Frank; Wu, Xiaoxi; Zhu, Yi; Wen, Haidan; Johnston, Scott; Shen, Zhi-Xun; Landreman, Patrick; Brongersma, Mark; Fong, Scott W; Wong, H-S Philip; Sher, Meng-Ju; Jost, Peter; Kaes, Matthias; Salinga, Martin; von Hoegen, Alexander; Wuttig, Matthias; Lindenberg, Aaron M

    2016-08-05

    Many chalcogenide glasses undergo a breakdown in electronic resistance above a critical field strength. Known as threshold switching, this mechanism enables field-induced crystallization in emerging phase-change memory. Purely electronic as well as crystal nucleation assisted models have been employed to explain the electronic breakdown. Here, picosecond electric pulses are used to excite amorphous Ag_{4}In_{3}Sb_{67}Te_{26}. Field-dependent reversible changes in conductivity and pulse-driven crystallization are observed. The present results show that threshold switching can take place within the electric pulse on subpicosecond time scales-faster than crystals can nucleate. This supports purely electronic models of threshold switching and reveals potential applications as an ultrafast electronic switch.

  1. SEM technique for imaging and measuring electronic transport in nanocomposites based on electric field induced contrast

    Science.gov (United States)

    Jesse, Stephen [Knoxville, TN; Geohegan, David B [Knoxville, TN; Guillorn, Michael [Brooktondale, NY

    2009-02-17

    Methods and apparatus are described for SEM imaging and measuring electronic transport in nanocomposites based on electric field induced contrast. A method includes mounting a sample onto a sample holder, the sample including a sample material; wire bonding leads from the sample holder onto the sample; placing the sample holder in a vacuum chamber of a scanning electron microscope; connecting leads from the sample holder to a power source located outside the vacuum chamber; controlling secondary electron emission from the sample by applying a predetermined voltage to the sample through the leads; and generating an image of the secondary electron emission from the sample. An apparatus includes a sample holder for a scanning electron microscope having an electrical interconnect and leads on top of the sample holder electrically connected to the electrical interconnect; a power source and a controller connected to the electrical interconnect for applying voltage to the sample holder to control the secondary electron emission from a sample mounted on the sample holder; and a computer coupled to a secondary electron detector to generate images of the secondary electron emission from the sample.

  2. Electric-field-induced modification in Curie temperature of Co monolayer on Pt(111)

    Science.gov (United States)

    Nakamura, Kohji; Oba, Mikito; Akiyama, Toru; Ito, Tomonori; Weinert, Michael

    2015-03-01

    Magnetism induced by an external electric field (E-field) has received much attention as a potential approach for controlling magnetism at the nano-scale with the promise of ultra-low energy power consumption. Here, the E-field-induced modification of the Curie temperature for a prototypical transition-metal thin layer of a Co monolayer on Pt(111) is investigated by first-principles calculations by using the full-potential linearized augmented plane wave method that treats spin-spiral structures in an E-field. An applied E-field modifies the magnon (spin-spiral formation) energies by a few meV, which leads to a modification of the exchange pair interaction parameters within the classical Heisenberg model. With inclusion of the spin-orbit coupling (SOC), the magnetocrystalline anisotropy and the Dzyaloshinskii-Morita interaction are obtained by the second variation SOC method. An E-field-induced modification of the Curie temperature is demonstrated by Monte Carlo simulations, in which a change in the exchange interaction is found to play a key role.

  3. The giant piezoelectric effect: electric field induced monoclinic phase or piezoelectric distortion of the rhombohedral parent?

    CERN Document Server

    Kisi, E H; Forrester, J S; Howard, C J

    2003-01-01

    Lead zinc niobate-lead titanate (PZN-PT) single crystals show very large piezoelectric strains for electric fields applied along the unit cell edges e.g. [001] sub R. It has been widely reported that this effect is caused by an electric field induced phase transition from rhombohedral (R3m) to monoclinic (Cm or Pm) symmetry in an essentially continuous manner. Group theoretical analysis using the computer program ISOTROPY indicates phase transitions between R3m and Cm (or Pm) must be discontinuous under Landau theory. An analysis of the symmetry of a strained unit cell in R3m and a simple expansion of the piezoelectric strain equation indicate that the piezoelectric distortion due to an electric field along a cell edge in rhombohedral perovskite-based ferroelectrics is intrinsically monoclinic (Cm), even for infinitesimal electric fields. PZN-PT crystals have up to nine times the elastic compliance of other piezoelectric perovskites and it might be expected that the piezoelectric strains are also very large. ...

  4. Field-induced magnetic phases and electric polarization in LiNiPO4

    DEFF Research Database (Denmark)

    Jensen, Thomas Bagger Stibius; Christensen, Niels Bech; Kenzelmann, M.

    2009-01-01

    Neutron diffraction is used to probe the (H,T) phase diagram of magnetoelectric (ME) LiNiPO4 for magnetic fields along the c axis. At zero field the Ni spins order in two antiferromagnetic phases. One has commensurate (C) structures and general ordering vectors k(C)=(0,0,0); the other one...... is incommensurate (IC) with k(IC)=(0,q,0). At low temperatures the C order collapses above mu H-0=12 T and adopts an IC structure with modulation vector parallel to k(IC). We show that C order is required for the ME effect and establish how electric polarization results from a field-induced reduction in the total...

  5. Study of interface layer effect in organic solar cells by electric-field-induced optical second-harmonic generation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Taguchi, Dai; Sumiyoshi, Ryota; Chen, Xiangyu; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp

    2014-03-03

    By using electric-field-induced optical second-harmonic generation (EFISHG) measurement, we studied the effect of the use of bathocuproine (BCP) interface layer. The EFISHG measurements of indium–zinc–oxide (IZO)/C{sub 60}/Al diodes showed that the BCP layer inserted between C{sub 60} and Al formed an electrostatic field |E{sub i}| = 2.5 × 10{sup 4} V/cm in the C{sub 60} layer, pointing in a direction from the Al to the IZO. Accordingly, in the IZO/pentacene/C{sub 60}/BCP/Al organic solar cells (OSCs), holes (electrons) move to the IZO (Al) electrode, enhancing the short-circuit current. The EFISHG measurement is capable of directly probing internal fields in the layers used for OSCs, and is helpful for studying the contribution of the interface layer in OSCs. - Highlights: • Internal field in organic solar cells (OSCs) were directly probed. • Interface layer formed internal electric field, enhancing the OSC performance. • Maxwell–Wagner effect accounts for the internal electric field formation.

  6. The influence of sulcus width on simulated electric fields induced by transcranial magnetic stimulation

    International Nuclear Information System (INIS)

    Janssen, A M; Rampersad, S M; Stegeman, D F; Oostendorp, T F; Lucka, F; Lanfer, B; Aydin, Ü; Wolters, C H; Lew, S

    2013-01-01

    Volume conduction models can help in acquiring knowledge about the distribution of the electric field induced by transcranial magnetic stimulation. One aspect of a detailed model is an accurate description of the cortical surface geometry. Since its estimation is difficult, it is important to know how accurate the geometry has to be represented. Previous studies only looked at the differences caused by neglecting the complete boundary between cerebrospinal fluid (CSF) and grey matter (Thielscher et al 2011 NeuroImage 54 234–43, Bijsterbosch et al 2012 Med. Biol. Eng. Comput. 50 671–81), or by resizing the whole brain (Wagner et al 2008 Exp. Brain Res. 186 539–50). However, due to the high conductive properties of the CSF, it can be expected that alterations in sulcus width can already have a significant effect on the distribution of the electric field. To answer this question, the sulcus width of a highly realistic head model, based on T1-, T2- and diffusion-weighted magnetic resonance images, was altered systematically. This study shows that alterations in the sulcus width do not cause large differences in the majority of the electric field values. However, considerable overestimation of sulcus width produces an overestimation of the calculated field strength, also at locations distant from the target location. (paper)

  7. The influence of sulcus width on simulated electric fields induced by transcranial magnetic stimulation

    Science.gov (United States)

    Janssen, A. M.; Rampersad, S. M.; Lucka, F.; Lanfer, B.; Lew, S.; Aydin, Ü.; Wolters, C. H.; Stegeman, D. F.; Oostendorp, T. F.

    2013-07-01

    Volume conduction models can help in acquiring knowledge about the distribution of the electric field induced by transcranial magnetic stimulation. One aspect of a detailed model is an accurate description of the cortical surface geometry. Since its estimation is difficult, it is important to know how accurate the geometry has to be represented. Previous studies only looked at the differences caused by neglecting the complete boundary between cerebrospinal fluid (CSF) and grey matter (Thielscher et al 2011 NeuroImage 54 234-43, Bijsterbosch et al 2012 Med. Biol. Eng. Comput. 50 671-81), or by resizing the whole brain (Wagner et al 2008 Exp. Brain Res. 186 539-50). However, due to the high conductive properties of the CSF, it can be expected that alterations in sulcus width can already have a significant effect on the distribution of the electric field. To answer this question, the sulcus width of a highly realistic head model, based on T1-, T2- and diffusion-weighted magnetic resonance images, was altered systematically. This study shows that alterations in the sulcus width do not cause large differences in the majority of the electric field values. However, considerable overestimation of sulcus width produces an overestimation of the calculated field strength, also at locations distant from the target location.

  8. Electric-Field-Induced Superconductivity Detected by Magnetization Measurements of an Electric-Double-Layer Capacitor

    NARCIS (Netherlands)

    Kasahara, Yuichi; Nishijima, Takahiro; Sato, Tatsuya; Takeuchi, Yuki; Ye, Jianting; Yuan, Hongtao; Shimotani, Hidekazu; Iwasa, Yoshihiro

    We report evidence for superconductivity induced by the application of strong electric fields onto the surface of a band insulator, ZrNCl, provided by the observation of a shielding diamagnetic signal. We introduced an electric-double-layer capacitor configuration and in situ magnetization

  9. Complex Electric-Field Induced Phenomena in Ferroelectric/Antiferroelectric Nanowires

    Science.gov (United States)

    Herchig, Ryan Christopher

    -principles-based modeling of electric-field-induced phenomena in ferroelectric/antiferroelectric nanowires in order to address the aforementioned questions. (Abstract shortened by ProQuest.).

  10. Electric-field-induced modification of the magnon energy, exchange interaction, and curie temperature of transition-metal thin films.

    Science.gov (United States)

    Oba, M; Nakamura, K; Akiyama, T; Ito, T; Weinert, M; Freeman, A J

    2015-03-13

    The electric-field-induced modification in the Curie temperature of prototypical transition-metal thin films with the perpendicular magnetic easy axis, a freestanding Fe(001) monolayer and a Co monolayer on Pt(111), is investigated by first-principles calculations of spin-spiral structures in an external electric field (E field). An applied E field is found to modify the magnon (spin-spiral formation) energy; the change arises from the E-field-induced screening charge density in the spin-spiral states due to p-d hybridizations. The Heisenberg exchange parameters obtained from the magnon energy suggest an E-field-induced modification of the Curie temperature, which is demonstrated via Monte Carlo simulations that take the magnetocrystalline anisotropy into account.

  11. Electric field measurements in a near atmospheric pressure nanosecond pulse discharge with picosecond electric field induced second harmonic generation

    Science.gov (United States)

    Goldberg, Benjamin M.; Chng, Tat Loon; Dogariu, Arthur; Miles, Richard B.

    2018-02-01

    We present an optical electric field measurement method for use in high pressure plasma discharges. The method is based upon the field induced second harmonic generation technique and can be used for localized electric field measurements with sub-nanosecond resolution in any gaseous species. When an external electric field is present, a dipole is induced in the typically centrosymmetric medium, allowing for second harmonic generation with signal intensities which scale by the square of the electric field. Calibrations have been carried out in 100 Torr room air, and a minimum sensitivity of 450 V/cm is demonstrated. Measurements were performed with nanosecond or faster temporal resolution in a 100 Torr room air environment both with and without a plasma present. It was shown that with no plasma present, the field follows the applied voltage to gap ratio, as measured using the back current shunt method. When the electric field is strong enough to exceed the breakdown threshold, the measured field was shown to exceed the anticipated voltage to gap ratio which is taken as an indication of the ionization wave front as it sweeps through the plasma volume.

  12. Electric-field-induced modification in Dzyaloshinskii-Moriya interaction of Co monolayer on Pt(111)

    Science.gov (United States)

    Nakamura, Kohji; Akiyama, Toru; Ito, Tomonori; Ono, Teruo; Weinert, Michael

    Magnetism induced by an external electric field (E-field) has received much attention as a potential approach for controlling magnetism at the nano-scale with the promise of ultra-low energy power consumption. Here, the E-field-induced modification of the Dzyaloshinskii-Moriya interaction (DMI) for a prototypical transition-metal thin layer of a Co monolayer on Pt(111) is investigated by first-principles calculations by using the full-potential linearized augmented plane wave method that treats spin-spiral structures in an E-field. With inclusion of the spin-orbit coupling (SOC) by the second variational method for commensurate spin-spiral structures, the DMI constants were estimated from an asymmetric contribution in the total energy with respect to the spin-spiral wavevector. The results predicted that the DMI is modified by the E-field, but the change is found to be small compared to that in the exchange interaction (a symmetric contribution in the total energy) by a factor of ten.

  13. In situ transmission electron microscopy study of the microstructural origins for the electric field-induced phenomena in ferroelectric perovskites

    Science.gov (United States)

    Guo, Hanzheng

    Ferroelectrics are important materials due to their extensive technological applications, such as non-volatile memories, field-effect transistors, ferroelectric tunneling junctions, dielectric capacitors, piezoelectric transducers, sensors and actuators. As is well known, the outstanding dielectric, piezoelectric, and ferroelectric properties of these functional oxides originate from their ferroelectric domain arrangements and the corresponding evolution under external stimuli (e.g. electric field, stress, and temperature). Electric field has been known as the most efficient stimulus to manipulate the ferroelectric domains through polarization switching and alignment. Therefore, direct observation of the dynamic process of electric field-induced domain evolution and crystal structure transformation is of significant importance to understand the microstructural mechanisms for the functional properties of ferroelectrics. In this dissertation, electric field in situ transmission electron microscopy (TEM) technique was employed to monitor the real-time evolution of the domain morphology and crystal structure during various electrical processes: (1) the initial poling process, (2) the electric field reversal process, and (3) the electrical cycling process. Two types of perovskite-structured ceramics, normal ferroelectrics and relaxor ferroelectrics, were used for this investigation. In addition to providing the microscopic insight for some well-accepted phase transformation rules, discoveries of some new or even unexpected physical phenomena were also demonstrated. For the initial poling process, microstructural origins for the piezoelectricity development in the three most promising lead-free piezoceramic systems were investigated. For the non-ergodic relaxor ferroelectric compositions ( x = 6% - 9%) in the (1-x)(Bi1/2Na 1/2)TiO3-xBaTiO3 system, well-developed piezoelectricity was realized at poling fields far below the coercive field and phase transition field. Such

  14. Kinetic model for electric-field induced point defect redistribution near semiconductor surfaces

    Science.gov (United States)

    Gorai, Prashun; Seebauer, Edmund G.

    2014-07-01

    The spatial distribution of point defects near semiconductor surfaces affects the efficiency of devices. Near-surface band bending generates electric fields that influence the spatial redistribution of charged mobile defects that exchange infrequently with the lattice, as recently demonstrated for pile-up of isotopic oxygen near rutile TiO2 (110). The present work derives a mathematical model to describe such redistribution and establishes its temporal dependence on defect injection rate and band bending. The model shows that band bending of only a few meV induces significant redistribution, and that the direction of the electric field governs formation of either a valley or a pile-up.

  15. Kinetic model for electric-field induced point defect redistribution near semiconductor surfaces

    International Nuclear Information System (INIS)

    Gorai, Prashun; Seebauer, Edmund G.

    2014-01-01

    The spatial distribution of point defects near semiconductor surfaces affects the efficiency of devices. Near-surface band bending generates electric fields that influence the spatial redistribution of charged mobile defects that exchange infrequently with the lattice, as recently demonstrated for pile-up of isotopic oxygen near rutile TiO 2 (110). The present work derives a mathematical model to describe such redistribution and establishes its temporal dependence on defect injection rate and band bending. The model shows that band bending of only a few meV induces significant redistribution, and that the direction of the electric field governs formation of either a valley or a pile-up.

  16. Precessional switching of antiferromagnets by electric field induced Dzyaloshinskii-Moriya torque

    Science.gov (United States)

    Kim, T. H.; Grünberg, P.; Han, S. H.; Cho, B. K.

    2018-05-01

    Antiferromagnetic insulators (AFIs) have attracted much interest from many researchers as promising candidates for use in ultrafast, ultralow-dissipation spintronic devices. As a fast method of reversing magnetization, precessional switching is realized when antiferromagnetic Néel orders l =(s1+s2 )/2 surmount the magnetic anisotropy or potential barrier in a given magnetic system, which is described well by the antiferromagnetic plane pendulum (APP) model. Here, we report that, as an alternative switching scenario, the direct coupling of an electric field with Dzyaloshinskii-Moriya (DM) interaction, which stems from spin-orbit coupling, is exploited for optimal switching. We derive the pendulum equation of motion of antiferromagnets, where DM torque is induced by a pulsed electric field. The temporal DM interaction is found to not only be in the form of magnetic torques (e.g., spin-orbit torque or magnetic field) but also modifies the magnetic potential that limits l 's activity; as a result, appropriate controls (e.g., direction, magnitude, and pulse shape) of the induced DM vector realize deterministic reversal in APP. The results present an approach for the control of a magnetic storage device by means of an electric field.

  17. Electric field-induced magnetoresistance in spin-valve/piezoelectric multiferroic laminates for low-power spintronics

    International Nuclear Information System (INIS)

    Huong Giang, D.T.; Thuc, V.N.; Duc, N.H.

    2012-01-01

    Electric field-induced magnetic anisotropy has been realized in the spin-valve-based {Ni 80 Fe 20 /Cu/Fe 50 Co 50 /IrMn}/piezoelectric multiferroic laminates. In this system, electric-field control of magnetization is accomplished by strain mediated magnetoelectric coupling. Practically, the magnetization in the magnetostrictive FeCo layer of the spin-valve structure rotates under an effective compressive stress caused by the inverse piezoelectric effect in external electrical fields. This phenomenon is evidenced by the magnetization and magnetoresistance changes under the electrical field applied across the piezoelectric layer. The result shows great potential for advanced low-power spintronic devices. - Highlights: ► Investigate electric field-induced magnetic anisotropy in spin-valve/piezoelectric. ► Magnetization, magnetoresistance changes under electric field across piezoelectric. ► Magnetization in magnetostrictive FeCo-layer rotates under a compressive stress. ► This advance shows great implications for low-power electronics and spintronics.

  18. Macroscopic electrical field distribution and field-induced surface stresses of needle-shaped field emitters

    Energy Technology Data Exchange (ETDEWEB)

    Moy, Charles K.S., E-mail: charles.moy@sydney.edu.au [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia); School of Civil Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Ranzi, Gianluca [ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia); School of Civil Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Petersen, Timothy C. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); Ringer, Simon P. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia)

    2011-05-15

    One major concern since the development of the field ion microscope is the mechanical strength of the specimens. The macroscopic shape of the imaging tip greatly influences field-induced stresses and there is merit in further study of this phenomenon from a classical perspective. Understanding the geometrical, as opposed to localized electronic, factors that affect the stress might improve the quality and success rate of atom probe experiments. This study uses macroscopic electrostatic principles and finite element modelling to investigate field-induced stresses in relation to the shape of the tip. Three two-dimensional idealized models are considered, namely hyperbolic, parabolic and sphere-on-orthogonal-cone; the shapes of which are compared to experimental tips prepared by electro-polishing. Three dimensional morphologies of both a nano-porous and single-crystal aluminium tip are measured using electron tomography to quantitatively test the assumption of cylindrical symmetry for electro-polished tips. The porous tip was prepared and studied to demonstrate a fragile specimen for which such finite element studies could determine potential mechanical failure, prior to any exhaustive atom probe investigation. -- Research highlights: {yields} We use electrostatic principles and finite element to model field-induced stresses. {yields} We study two-dimensional idealized needle-shaped field emitters. {yields} Stress distribution of hyperbolic, parabolic and sphere-on-orthogonal-cone tips mapped. {yields} Electron tomography to obtain the morphology of three-dimensional aluminium tips. {yields} Studies of the morphology of the porous tip demonstrate a fragile specimen.

  19. Quantifying pulsed electric field-induced membrane nanoporation in single cells.

    Science.gov (United States)

    Moen, Erick K; Ibey, Bennett L; Beier, Hope T; Armani, Andrea M

    2016-11-01

    Plasma membrane disruption can trigger a host of cellular activities. One commonly observed type of disruption is pore formation. Molecular dynamic (MD) simulations of simplified lipid membrane structures predict that controllably disrupting the membrane via nano-scale poration may be possible with nanosecond pulsed electric fields (nsPEF). Until recently, researchers hoping to verify this hypothesis experimentally have been limited to measuring the relatively slow process of fluorescent markers diffusing across the membrane, which is indirect evidence of nanoporation that could be channel-mediated. Leveraging recent advances in nonlinear optical microscopy, we elucidate the role of pulse parameters in nsPEF-induced membrane permeabilization in live cells. Unlike previous techniques, it is able to directly observe loss of membrane order at the onset of the pulse. We also develop a complementary theoretical model that relates increasing membrane permeabilization to membrane pore density. Due to the significantly improved spatial and temporal resolution possible with our imaging method, we are able to directly compare our experimental and theoretical results. Their agreement provides substantial evidence that nanoporation does occur and that its development is dictated by the electric field distribution. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. AC electric field induced dipole-based on-chip 3D cell rotation.

    Science.gov (United States)

    Benhal, Prateek; Chase, J Geoffrey; Gaynor, Paul; Oback, Björn; Wang, Wenhui

    2014-08-07

    The precise rotation of suspended cells is one of the many fundamental manipulations used in a wide range of biotechnological applications such as cell injection and enucleation in nuclear transfer (NT) cloning. Noticeably scarce among the existing rotation techniques is the three-dimensional (3D) rotation of cells on a single chip. Here we present an alternating current (ac) induced electric field-based biochip platform, which has an open-top sub-mm square chamber enclosed by four sidewall electrodes and two bottom electrodes, to achieve rotation about the two axes, thus 3D cell rotation. By applying an ac potential to the four sidewall electrodes, an in-plane (yaw) rotating electric field is generated and in-plane rotation is achieved. Similarly, by applying an ac potential to two opposite sidewall electrodes and the two bottom electrodes, an out-of-plane (pitch) rotating electric field is generated and rolling rotation is achieved. As a prompt proof-of-concept, bottom electrodes were constructed with transparent indium tin oxide (ITO) using the standard lift-off process and the sidewall electrodes were constructed using a low-cost micro-milling process and then assembled to form the chip. Through experiments, we demonstrate rotation of bovine oocytes of ~120 μm diameter about two axes, with the capability of controlling the rotation direction and the rate for each axis through control of the ac potential amplitude, frequency, and phase shift, and cell medium conductivity. The maximum observed rotation rate reached nearly 140° s⁻¹, while a consistent rotation rate reached up to 40° s⁻¹. Rotation rate spectra for zona pellucida-intact and zona pellucida-free oocytes were further compared and found to have no effective difference. This simple, transparent, cheap-to-manufacture, and open-top platform allows additional functional modules to be integrated to become a more powerful cell manipulation system.

  1. Controlling molecular condensation/diffusion of copper phthalocyanine by local electric field induced with scanning tunneling microscope tip

    Science.gov (United States)

    Nagaoka, Katsumi; Yaginuma, Shin; Nakayama, Tomonobu

    2018-02-01

    We have discovered the condensation/diffusion phenomena of copper phthalocyanine (CuPc) molecules controlled with a pulsed electric field induced by the scanning tunneling microscope tip. This behavior is not explained by the conventional induced dipole model. In order to understand the mechanism, we have measured the electronic structure of the molecule by tunneling spectroscopy and also performed theoretical calculations on molecular orbitals. These data clearly indicate that the molecule is positively charged owing to charge transfer to the substrate, and that hydrogen bonding exists between CuPc molecules, which makes the molecular island stable.

  2. Using hydrocarbon as a carbon source for synthesis of carbon nanotube by electric field induced needle-pulsed plasma

    International Nuclear Information System (INIS)

    Kazemi Kia, Kaveh; Bonabi, Fahimeh

    2013-01-01

    In this work different hydrocarbons are used as the carbon source, in the production of carbon nanotubes (CNTs) and nano onions. An electric field induced needle pulse arc-discharge reactor is used. The influence of starting carbon on the synthesis of CNTs is investigated. The production efficiency is compared for Acetone, Isopropanol and Naphthalene as simple hydrocarbons. The hydrocarbons are preheated and then pretreated by electric field before being exposed to plasma. The hydrocarbon vapor is injected into plasma through a graphite spout in the cathode assembly. The pulsed plasma takes place between two graphite rods while a strong electric field has been already established alongside the electrodes. The pulse width is 0.3 μs. Mechanism of precursor decomposition is discussed by describing three forms of energy that are utilized to disintegrate the precursor molecules: thermal energy, electric field and kinetic energy of plasma. Molecular polarity of a hydrocarbon is one of the reasons for choosing carbon raw material as a precursor in an electric field induced low power pulsed-plasma. The results show that in order to obtain high quality carbon nanotubes, Acetone is preferred to Isopropanol and Naphthalene. Scanning probe microscopy techniques are used to investigate the products. - Highlights: • We synthesized CNTs (carbon nano tubes) by needle pulsed plasma. • We use different hydrocarbons as carbon source in the production of CNTs. • We investigated the influence of starting carbon on the synthesis of CNTs. • Thermal energy, electric field and kinetic energy are used to break carbon bonds. • Polar hydrocarbon molecules are more efficient than nonpolar ones in production

  3. Sheared electric field-induced suppression of edge turbulence using externally driven R.F. waves

    International Nuclear Information System (INIS)

    Craddock, G.G.; Diamond, P.H.

    1991-01-01

    Here the authors propose a novel method for active control and suppression of edge turbulence by sheared ExB flows driven by externally launched RF waves. The theory developed addresses the problem of open-quotes flow driveclose quotes, which is somewhat analogous to the problem of plasma current drive. As originally demonstrated for the case of spontaneously driven flows, a net difference in the gradient of the fluid and magnetic Reynolds' stresses produced by radially propagating waves can drive the plasma flow. For the prototypical case of the Alfven wave flow drive considered here, ρ 0 r v θ > - r B θ > is proportional to k perpendicular 2 ρ s 2 in the case of the kinetic Alfven wave, and [(ηk perpendicular 2 -vk perpendicular 2 )/ω] 2 in the case of resistive MHD. Both results reflect the dependence of flow drive on the net stress imbalance. The shear layer width is determined by the waves evanescence length (determined by dissipation) that sets the stress gradient scale length, while the direction of the flow is determined by the poloidal orientation of the launched waves. In particular, it should be noted that both positive and negative E r may be driven, so that enhanced confinement need not be accompanied by impurity accumulation, as commonly encountered in spontaneous H-modes. The efficiency is determined by the criterion that the radial electric field shear be large enough to suppress turbulence. For typical TEXT parameters, and unity efficiency, 300 kW of absorbed power is needed to suppress turbulence over 3 cm radially. For DIII-D, 300 kW over 4 cm is needed. Also, direct transport losses induced by RF have been shown to be small. Extensions of the theory to ICRF are underway and are discussed. They also discuss the analogous problem of current drive using kinetic Alfven waves. 2 refs

  4. Electric-Field-Induced Magnetization Reversal in a Ferromagnet-Multiferroic Heterostructure

    Science.gov (United States)

    Heron, J. T.; Trassin, M.; Ashraf, K.; Gajek, M.; He, Q.; Yang, S. Y.; Nikonov, D. E.; Chu, Y.-H.; Salahuddin, S.; Ramesh, R.

    2011-11-01

    A reversal of magnetization requiring only the application of an electric field can lead to low-power spintronic devices by eliminating conventional magnetic switching methods. Here we show a nonvolatile, room temperature magnetization reversal determined by an electric field in a ferromagnet-multiferroic system. The effect is reversible and mediated by an interfacial magnetic coupling dictated by the multiferroic. Such electric-field control of a magnetoelectric device demonstrates an avenue for next-generation, low-energy consumption spintronics.

  5. Electron mobility variance in the presence of an electric field: Electron-phonon field-induced tunnel scattering

    International Nuclear Information System (INIS)

    Melkonyan, S.V.

    2012-01-01

    The problem of electron mobility variance is discussed. It is established that in equilibrium semiconductors the mobility variance is infinite. It is revealed that the cause of the mobility variance infinity is the threshold of phonon emission. The electron-phonon interaction theory in the presence of an electric field is developed. A new mechanism of electron scattering, called electron-phonon field-induced tunnel (FIT) scattering, is observed. The effect of the electron-phonon FIT scattering is explained in terms of penetration of the electron wave function into the semiconductor band gap in the presence of an electric field. New and more general expressions for the electron-non-polar optical phonon scattering probability and relaxation time are obtained. The results show that FIT transitions have principle meaning for the mobility fluctuation theory: mobility variance becomes finite.

  6. AC electric field induced droplet deformation in a microfluidic T-junction.

    Science.gov (United States)

    Xi, Heng-Dong; Guo, Wei; Leniart, Michael; Chong, Zhuang Zhi; Tan, Say Hwa

    2016-08-02

    We present for the first time an experimental study on the droplet deformation induced by an AC electric field in droplet-based microfluidics. It is found that the deformation of the droplets becomes stronger with increasing electric field intensity and frequency. The measured electric field intensity dependence of the droplet deformation is consistent with an early theoretical prediction for stationary droplets. We also proposed a simple equivalent circuit model to account for the frequency dependence of the droplet deformation. The model well explains our experimental observations. In addition, we found that the droplets can be deformed repeatedly by applying an amplitude modulation (AM) signal.

  7. Electric-field-induced flow-aligning state in a nematic liquid crystal.

    Science.gov (United States)

    Fatriansyah, Jaka Fajar; Orihara, Hiroshi

    2015-04-01

    The response of shear stress to a weak ac electric field as a probe is measured in a nematic liquid crystal under shear flow and dc electric fields. Two states with different responses are clearly observed when the dc electric field is changed at a constant shear rate: the flow aligning and non-flow aligning states. The director lies in the shear plane in the flow aligning state and out of the plane in the non-flow aligning state. Through application of dc electric field, the non-flow aligning state can be changed to the flow aligning state. In the transition from the flow aligning state to the non-flow aligning state, it is found that the response increases and the relaxation time becomes longer. Here, the experimental results in the flow aligning state are discussed on the basis of the Ericksen-Leslie theory.

  8. Lateral-electric-field-induced spin polarization in a suspended GaAs quantum point contact

    Science.gov (United States)

    Pokhabov, D. A.; Pogosov, A. G.; Zhdanov, E. Yu.; Shevyrin, A. A.; Bakarov, A. K.; Shklyaev, A. A.

    2018-02-01

    The conductance of a GaAs-based suspended quantum point contact (QPC) equipped with lateral side gates has been experimentally studied in the absence of the external magnetic field. The half-integer conductance plateau ( 0.5 ×2 e2/h ) has been observed when an asymmetric voltage between the side gates is applied. The appearance of this plateau has been attributed to the spin degeneracy lifting caused by the spin-orbit coupling associated with the lateral electric field in the asymmetrically biased QPC. We have experimentally demonstrated that, despite the relatively small g-factor in GaAs, the observation of the spin polarization in the GaAs-based QPC became possible after the suspension due to the enhancement of the electron-electron interaction and the effect of the electric field guiding. These features are caused by a partial confinement of the electric field lines within a suspended semiconductor layer with a high dielectric constant.

  9. Controlling nanowire growth through electric field-induced deformation of the catalyst droplet

    DEFF Research Database (Denmark)

    Panciera, Federico; Norton, Michael M.; Alam, Sardar Bilal

    2016-01-01

    electron microscope show that the electric field modifies growth by changing the shape, position and contact angle of the catalytic droplet. This droplet engineering can be used to modify nanowires into three dimensional structures, relevant to a range of applications, and also to measure the droplet...

  10. Electric field induced removal of the biexciton binding energy in a single quantum dot

    NARCIS (Netherlands)

    Reimer, M.E.; Kouwen, Van M.P.; Hidma, A.W.; Weert, van M.H.M.; Bakkers, E.P.A.M.; Kouwenhoven, L.P.; Zwiller, V.

    2011-01-01

    We control the electrostatic environment of a single InAsP quantum dot in an InP nanowire with two contacts and two lateral gates positioned to an individual nanowire. We empty the quantum dot of excess charges and apply an electric field across its radial dimension. A large tuning range for the

  11. Relativistic Néel-Order Fields Induced by Electrical Current in Antiferromagnets

    KAUST Repository

    Železný, J.

    2014-10-06

    We predict that a lateral electrical current in antiferromagnets can induce nonequilibrium Néel-order fields, i.e., fields whose sign alternates between the spin sublattices, which can trigger ultrafast spin-axis reorientation. Based on microscopic transport theory calculations we identify staggered current-induced fields analogous to the intraband and to the intrinsic interband spin-orbit fields previously reported in ferromagnets with a broken inversion-symmetry crystal. To illustrate their rich physics and utility, we consider bulk Mn2Au with the two spin sublattices forming inversion partners, and a 2D square-lattice antiferromagnet with broken structural inversion symmetry modeled by a Rashba spin-orbit coupling. We propose an antiferromagnetic memory device with electrical writing and reading.

  12. Relativistic Néel-Order Fields Induced by Electrical Current in Antiferromagnets

    KAUST Repository

    Železný , J.; Gao, H.; Vý borný , K.; Zemen, J.; Mašek, J.; Manchon, Aurelien; Wunderlich, J.; Sinova, Jairo; Jungwirth, T.

    2014-01-01

    We predict that a lateral electrical current in antiferromagnets can induce nonequilibrium Néel-order fields, i.e., fields whose sign alternates between the spin sublattices, which can trigger ultrafast spin-axis reorientation. Based on microscopic transport theory calculations we identify staggered current-induced fields analogous to the intraband and to the intrinsic interband spin-orbit fields previously reported in ferromagnets with a broken inversion-symmetry crystal. To illustrate their rich physics and utility, we consider bulk Mn2Au with the two spin sublattices forming inversion partners, and a 2D square-lattice antiferromagnet with broken structural inversion symmetry modeled by a Rashba spin-orbit coupling. We propose an antiferromagnetic memory device with electrical writing and reading.

  13. Model of electric field-induced charge disordering in praseodymium manganites

    International Nuclear Information System (INIS)

    Lapinskas, S.; Tornau, E.E.; Semiconductor Physics Inst., Vilnius

    2001-01-01

    We propose a model for an electric field-driven transition from the ordered NaCl-type phase to the disordered phase. Such a transition might be a prototype of charge disordering transition observed in Pr 1-c Ca c MnO 3 . We assume the lattice-gas model and hopping conductivity of charge carriers. The solution of this model, performed by the Monte Carlo method, demonstrates that considerably high electric field can disorder well-ordered phases. The comparison with the data for charge disordering in Pr 1-c Ca c MnO 3 shows that required fields are much too high. We analyze the obtained results trying to determine a possible scenario for conductivity in Pr 1-c Ca c MnO 3 . (orig.)

  14. Analytical Formulation of the Electric Field Induced by Electrode Arrays: Towards Automated Dielectrophoretic Cell Sorting

    Directory of Open Access Journals (Sweden)

    Vladimir Gauthier

    2017-08-01

    Full Text Available Dielectrophoresis is defined as the motion of an electrically polarisable particle in a non-uniform electric field. Current dielectrophoretic devices enabling sorting of cells are mostly controlled in open-loop applying a predefined voltage on micro-electrodes. Closed-loop control of these devices would enable to get advanced functionalities and also more robust behavior. Currently, the numerical models of dielectrophoretic force are too complex to be used in real-time closed-loop control. The aim of this paper is to propose a new type of models usable in this framework. We propose an analytical model of the electric field based on Fourier series to compute the dielectrophoretic force produced by parallel electrode arrays. Indeed, this method provides an analytical expression of the electric potential which decouples the geometrical factors (parameter of our system, the voltages applied on electrodes (input of our system, and the position of the cells (output of our system. Considering the Newton laws on each cell, it enables to generate easily a dynamic model of the cell positions (output function of the voltages on electrodes (input. This dynamic model of our system is required to design the future closed-loop control law. The predicted dielectrophoretic forces are compared to a numerical simulation based on finite element model using COMSOL software. The model presented in this paper enables to compute the dielectrophoretic force applied to a cell by an electrode array in a few tenths of milliseconds. This model could be consequently used in future works for closed-loop control of dielectrophoretic devices.

  15. Electric field-induced valley degeneracy lifting in uniaxial strained graphene: evidence from magnetophonon resonance

    OpenAIRE

    Assili, Mohamed; Haddad, Sonia; Kang, Woun

    2015-01-01

    A double peak structure in the magneto-phonon resonance (MPR) spectrum of uniaxial strained graphene, under crossed electric and magnetic fields, is predicted. We focus on the $\\Gamma$ point optical phonon modes coupled to the inter-Landau level transitions $0 \\leftrightarrows \\pm 1$ where MPR is expected to be more pronounced at high magnetic field. We derive the frequency shifts and the broadenings of the longitudinal (LO) and transverse (TO) optical phonon modes taking into account the eff...

  16. Effect Of Electric Field Induced Texture On The Properties Of Piezoelectric Lead Zirconate Titanate

    International Nuclear Information System (INIS)

    Alkoy, S.

    2010-01-01

    Texturing a polycrystalline piezoelectric ceramic provide single-crystal like properties without experiencing any difficulties of single crystal growth process. This study reports a method to obtain texture in PbZr 0 .5Ti 0 .5O 3 ceramics by application of an electric field during gelation of a gelcast slurry. Gelcasting provides a means to lock the particles aligned under the application of a high electric field via gelation and this alignment in green body was retained after sintering. Monomer, cross linker and dispersant were dissolved in DI water and PZT powder was dispersed in this premix. Iniator and catalyzer were added to the slurry. An electric field was applied to the slurry for 30 min during gelation. XRD pattern of sintered samples indicates that PZT develops a tetragonal symmetry as a result of E-field applied during gelation. Dielectric constants and piezoelectric d 3 3 coefficients along and perpendicular to E-field are 1070 and 450 and 390 and 280 pC/N, respectively.

  17. Electric-field induced spin accumulation in the Landau level states of topological insulator thin films

    Science.gov (United States)

    Siu, Zhuo Bin; Chowdhury, Debashree; Basu, Banasri; Jalil, Mansoor B. A.

    2017-08-01

    A topological insulator (TI) thin film differs from the more typically studied thick TI system in that the former has both a top and a bottom surface where the states localized at both surfaces can couple to one other across the finite thickness. An out-of-plane magnetic field leads to the formation of discrete Landau level states in the system, whereas an in-plane magnetization breaks the angular momentum symmetry of the system. In this work, we study the spin accumulation induced by the application of an in-plane electric field to the TI thin film system where the Landau level states and inter-surface coupling are simultaneously present. We show, via Kubo formula calculations, that the in-plane spin accumulation perpendicular to the magnetization due to the electric field vanishes for a TI thin film with symmetric top and bottom surfaces. A finite in-plane spin accumulation perpendicular to both the electric field and magnetization emerges upon applying either a differential magnetization coupling or a potential difference between the two film surfaces. This spin accumulation results from the breaking of the antisymmetry of the spin accumulation around the k-space equal-energy contours.

  18. Electric field-induced valley degeneracy lifting in uniaxial strained graphene: Evidence from magnetophonon resonance

    Science.gov (United States)

    Assili, Mohamed; Haddad, Sonia; Kang, Woun

    2015-03-01

    A double peak structure in the magnetophonon resonance (MPR) spectrum of uniaxial strained graphene, under crossed electric and magnetic fields, is predicted. We focus on the Γ point optical phonon modes coupled to the inter-Landau level transitions 0 ⇆±1 where MPR is expected to be more pronounced at high magnetic field. We derive the frequency shifts and the broadenings of the longitudinal and transverse optical phonon modes taking into account the effect of the strain modified electronic spectrum on the electron-phonon coupling. We show that the MPR line for a given phonon mode acquires a double peak structure originating from the twofold valley degeneracy lifting. The latter is due to the different Landau level spacings in the two Dirac valleys resulting from the simultaneous action of the inplane electric field and the strain-induced Dirac cone tilt. We discuss the role of some key parameters such as disorder, strain, doping, and electric field amplitude on the emergence of the double peak structure.

  19. Electric field induced needle-pulsed arc discharge carbon nanotube production apparatus: Circuitry and mechanical design

    Energy Technology Data Exchange (ETDEWEB)

    Kia, Kaveh Kazemi [Department of Electrical and Computer Engineering, Islamic Azad University of Bonab, Bonab (Iran, Islamic Republic of); Bonabi, Fahimeh [Department of Engineering, Islamic Azad University of Bonab, Bonab (Iran, Islamic Republic of)

    2012-12-15

    A simple and low cost apparatus is reported to produce multiwall carbon nanotubes and carbon nano-onions by a low power short pulsed arc discharge reactor. The electric circuitry and the mechanical design details and a micro-filtering assembly are described. The pulsed-plasma is generated and applied between two graphite electrodes. The pulse width is 0.3 {mu}s. A strong dc electric field is established along side the electrodes. The repetitive discharges occur in less than 1 mm distance between a sharp tip graphite rod as anode, and a tubular graphite as cathode. A hydrocarbon vapor, as carbon source, is introduced through the graphite nozzle in the cathode assembly. The pressure of the chamber is controlled by a vacuum pump. A magnetic field, perpendicular to the plasma path, is provided. The results show that the synergetic use of a pulsed-current and a dc power supply enables us to synthesize carbon nanoparticles with short pulsed plasma. The simplicity and inexpensiveness of this plan is noticeable. Pulsed nature of plasma provides some extra degrees of freedom that make the production more controllable. Effects of some design parameters such as electric field, pulse frequency, and cathode shape are discussed. The products are examined using scanning probe microscopy techniques.

  20. Electric field induced needle-pulsed arc discharge carbon nanotube production apparatus: circuitry and mechanical design.

    Science.gov (United States)

    Kia, Kaveh Kazemi; Bonabi, Fahimeh

    2012-12-01

    A simple and low cost apparatus is reported to produce multiwall carbon nanotubes and carbon nano-onions by a low power short pulsed arc discharge reactor. The electric circuitry and the mechanical design details and a micro-filtering assembly are described. The pulsed-plasma is generated and applied between two graphite electrodes. The pulse width is 0.3 μs. A strong dc electric field is established along side the electrodes. The repetitive discharges occur in less than 1 mm distance between a sharp tip graphite rod as anode, and a tubular graphite as cathode. A hydrocarbon vapor, as carbon source, is introduced through the graphite nozzle in the cathode assembly. The pressure of the chamber is controlled by a vacuum pump. A magnetic field, perpendicular to the plasma path, is provided. The results show that the synergetic use of a pulsed-current and a dc power supply enables us to synthesize carbon nanoparticles with short pulsed plasma. The simplicity and inexpensiveness of this plan is noticeable. Pulsed nature of plasma provides some extra degrees of freedom that make the production more controllable. Effects of some design parameters such as electric field, pulse frequency, and cathode shape are discussed. The products are examined using scanning probe microscopy techniques.

  1. Electric-field-induced internal deformation in piezoelectric BiB{sub 3}O{sub 6} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, O.; Gorfman, S.; Pietsch, U. [Solid State Physics Department, University of Siegen (Germany)

    2008-11-15

    For the first time electric-field-induced atomic displacements (internal strains) in non-ferroelectric polar BiB{sub 3}O{sub 6} single crystal plates (point symmetry 2) were investigated using X-ray diffraction technique. The intensity variations of selected Bragg reflections were collected for three different orientations of the applied external electric field vector with respect to the crystal lattice and used for calculating the microscopic structural response of BiB{sub 3}O{sub 6}. Due to the limited number of the reflections providing measurable changes in Bragg intensities we restricted ourselves in analyzing the shift of the B{sub 3}O{sub 6} sublattice relative to the Bi one. In addition, we considered the deformation of the Bi-O, B(1)-O and B(2)-O bond lengths and identified the [B(2)O{sub 3}] group as the most sensitive structural unit to an external electric perturbation. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Floating liquid bridge tensile behavior: Electric-field-induced Young's modulus measurements

    Science.gov (United States)

    Teschke, Omar; Mendez Soares, David; Valente Filho, Juracyr Ferraz

    2013-12-01

    A floating bridge is formed spontaneously when high voltage is applied to polar fluids in two capillary tubes that were in contact and then separated. This bridge bends under its own weight, and its bending profile was used to calculate its Young's modulus. For electric field intensities of ˜106 V/m, water bridges exhibit viscoelastic behavior, with Young's moduli of ˜24 MPa; dimethylsulfoxide (DMSO) bridges exhibited Young's moduli of ˜60 kPa. The scheme devised to measure the voltage drop across the water bridge for high voltages applied between the electrodes shows that the bulk water resistance decreases with increasing voltage.

  3. The electric field induced by transcranial magnetic stimulation: A comparison between analytic and fem solutions

    Directory of Open Access Journals (Sweden)

    Porzig Konstantin

    2014-01-01

    Full Text Available The induced electric field profiles in a homogeneous isotropic sphere, were calculated and compared between an analytic and a finite-element method in the framework of transcranial magnetic stimulation (TMS. This model can also be applied for concentric spheres in the framework of magnetic induction tomography (MIT, non destructive testing (NDT or to calculate the lead field in magnetoencephalography (MEG. The calculations were performed using Eaton’s method as well as the finite-element program Comsol Multiphysics 4.2a (COMSOL Inc., Burlington, USA. A circular- and a figure-of-8 coil were used to operate as the sources of excitation. In our study the spherical volume conductor represents the human head consisting of grey matter. In order to quantify the differences between both methods an intense parameter study was performed. A comparison between both methods show a higher conformity than reported in previous studies. Regarding Eaton’s method, the influence of the maximum order of approximation L and the number of elements per winding K was investigated. The maximum relative difference was approximately 0.3% for L = 20 and K > 16. Furthermore the relative efficiency of the algorithm was calculated to save computational time. With the presented results it is possible to use Eaton’s method efficiently to compute the induced electric field profiles very quickly for example while searching for specific coil arrangements around the humans head, as in the case of deep brain transcranial magnetic stimulation (dTMS.

  4. Electric field-induced reorganization of two-component supported bilayer membranes.

    Science.gov (United States)

    Groves, J T; Boxer, S G; McConnell, H M

    1997-12-09

    Application of electric fields tangent to the plane of a confined patch of fluid bilayer membrane can create lateral concentration gradients of the lipids. A thermodynamic model of this steady-state behavior is developed for binary systems and tested with experiments in supported lipid bilayers. The model uses Flory's approximation for the entropy of mixing and allows for effects arising when the components have different molecular areas. In the special case of equal area molecules the concentration gradient reduces to a Fermi-Dirac distribution. The theory is extended to include effects from charged molecules in the membrane. Calculations show that surface charge on the supporting substrate substantially screens electrostatic interactions within the membrane. It also is shown that concentration profiles can be affected by other intermolecular interactions such as clustering. Qualitative agreement with this prediction is provided by comparing phosphatidylserine- and cardiolipin-containing membranes.

  5. An electric field induced in the retina and brain at threshold magnetic flux density causing magnetophosphenes

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Akimasa; Takano, Yukinori; Fujiwara, Osamu [Nagoya Institute of Technology, Department of Computer Science and Engineering (Japan); Dovan, Thanh [SP AusNet, Division of Network Strategy and Development (Australia); Kavet, Robert, E-mail: ahirata@nitech.ac.jp [Electric Power Research Institute, Palo Alto, CA (United States)

    2011-07-07

    For magnetic field exposures at extremely low frequencies, the electrostimulatory response with the lowest threshold is the magnetophosphene, a response that corresponds to an adult exposed to a 20 Hz magnetic field of nominally 8.14 mT. In the IEEE standard C95.6 (2002), the corresponding in situ field in the retinal locus of an adult-sized ellipsoidal was calculated to be 53 mV m{sup -1}. However, the associated dose in the retina and brain at a high level of resolution in anatomically correct human models is incompletely characterized. Furthermore, the dose maxima in tissue computed with voxel human models are prone to staircasing errors, particularly for the low-frequency dosimetry. In the analyses presented in this paper, analytical and quasi-static finite-difference time-domain (FDTD) solutions were first compared for a three-layer sphere exposed to a uniform 50 Hz magnetic field. Staircasing errors in the FDTD results were observed at the tissue interface, and were greatest at the skin-air boundary. The 99th percentile value was within 3% of the analytic maximum, depending on model resolution, and thus may be considered a close approximation of the analytic maximum. For the adult anatomical model, TARO, exposed to a uniform magnetic field, the differences in the 99th percentile value of in situ electric fields for 2 mm and 1 mm voxel models were at most several per cent. For various human models exposed at the magnetophosphene threshold at three orthogonal field orientations, the in situ electric field in the brain was between 10% and 70% greater than the analytical IEEE threshold of 53 mV m{sup -1}, and in the retina was lower by roughly 50% for two horizontal orientations (anterior-posterior and lateral), and greater by about 15% for a vertically oriented field. Considering a reduction factor or safety factors of several folds applied to electrostimulatory thresholds, the 99th percentile dose to a tissue calculated with voxel human models may be used as an

  6. An electric field induced in the retina and brain at threshold magnetic flux density causing magnetophosphenes

    International Nuclear Information System (INIS)

    Hirata, Akimasa; Takano, Yukinori; Fujiwara, Osamu; Dovan, Thanh; Kavet, Robert

    2011-01-01

    For magnetic field exposures at extremely low frequencies, the electrostimulatory response with the lowest threshold is the magnetophosphene, a response that corresponds to an adult exposed to a 20 Hz magnetic field of nominally 8.14 mT. In the IEEE standard C95.6 (2002), the corresponding in situ field in the retinal locus of an adult-sized ellipsoidal was calculated to be 53 mV m -1 . However, the associated dose in the retina and brain at a high level of resolution in anatomically correct human models is incompletely characterized. Furthermore, the dose maxima in tissue computed with voxel human models are prone to staircasing errors, particularly for the low-frequency dosimetry. In the analyses presented in this paper, analytical and quasi-static finite-difference time-domain (FDTD) solutions were first compared for a three-layer sphere exposed to a uniform 50 Hz magnetic field. Staircasing errors in the FDTD results were observed at the tissue interface, and were greatest at the skin-air boundary. The 99th percentile value was within 3% of the analytic maximum, depending on model resolution, and thus may be considered a close approximation of the analytic maximum. For the adult anatomical model, TARO, exposed to a uniform magnetic field, the differences in the 99th percentile value of in situ electric fields for 2 mm and 1 mm voxel models were at most several per cent. For various human models exposed at the magnetophosphene threshold at three orthogonal field orientations, the in situ electric field in the brain was between 10% and 70% greater than the analytical IEEE threshold of 53 mV m -1 , and in the retina was lower by roughly 50% for two horizontal orientations (anterior-posterior and lateral), and greater by about 15% for a vertically oriented field. Considering a reduction factor or safety factors of several folds applied to electrostimulatory thresholds, the 99th percentile dose to a tissue calculated with voxel human models may be used as an

  7. Anisotropic Metal Deposition on TiO2 Particles by Electric-Field-Induced Charge Separation.

    Science.gov (United States)

    Tiewcharoen, Supakit; Warakulwit, Chompunuch; Lapeyre, Veronique; Garrigue, Patrick; Fourier, Lucas; Elissalde, Catherine; Buffière, Sonia; Legros, Philippe; Gayot, Marion; Limtrakul, Jumras; Kuhn, Alexander

    2017-09-11

    Deposition of metals on TiO 2 semiconductor particles (M-TiO 2 ) results in hybrid Janus objects combining the properties of both materials. One of the techniques proposed to generate Janus particles is bipolar electrochemistry (BPE). The concept can be applied in a straightforward way for the site-selective modification of conducting particles, but is much less obvious to use for semiconductors. Herein we report the bulk synthesis of anisotropic M-TiO 2 particles based on the synergy of BPE and photochemistry, allowing the intrinsic limitations, when they are used separately, to be overcome. When applying electric fields during irradiation, electrons and holes can be efficiently separated, thus breaking the symmetry of particles by modifying them selectively and in a wireless way on one side with either gold or platinum. Such hybrid materials are an important first step towards high-performance designer catalyst particles, for example for photosplitting of water. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Control of superconductivity by means of electric-field-induced strain in superconductor/piezoelectric hybrids

    Science.gov (United States)

    Stamopoulos, D.; Zeibekis, M.; Zhang, S. J.

    2018-01-01

    The controlled modification of superconductivity by any means, specifically in hybrid systems, has attracted much interest in the recent decades. Here, we present experimental data and phenomenological modeling on the control of TC of superconducting (SC) Nb thin films, with thickness 3 nm ≤ dN b≤50 nm, under the application of in-plane strain, S(Eex) induced by an external out-of-plane electric field, Eex to piezoelectric (PE) single crystals, namely, ( 1 -x )Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT), with x = 0.27 and 0.31. We report experimental modification of TC of Nb by Eex, accurately described by a phenomenological model that incorporates the constitutive relation S(Eex) of PMN-xPT. The systematic experimental-phenomenological modeling approach introduced here is generic and paves the way for an understanding of the underlying physical mechanisms in any SC/PE hybrid.

  9. Localized electric field induced transition and miniaturization of two-phase flow patterns inside microchannels.

    Science.gov (United States)

    Sharma, Abhinav; Tiwari, Vijeet; Kumar, Vineet; Mandal, Tapas Kumar; Bandyopadhyay, Dipankar

    2014-10-01

    Strategic application of external electrostatic field on a pressure-driven two-phase flow inside a microchannel can transform the stratified or slug flow patterns into droplets. The localized electrohydrodynamic stress at the interface of the immiscible liquids can engender a liquid-dielectrophoretic deformation, which disrupts the balance of the viscous, capillary, and inertial forces of a pressure-driven flow to engender such flow morphologies. Interestingly, the size, shape, and frequency of the droplets can be tuned by varying the field intensity, location of the electric field, surface properties of the channel or fluids, viscosity ratio of the fluids, and the flow ratio of the phases. Higher field intensity with lower interfacial tension is found to facilitate the oil droplet formation with a higher throughput inside the hydrophilic microchannels. The method is successful in breaking down the regular pressure-driven flow patterns even when the fluid inlets are exchanged in the microchannel. The simulations identify the conditions to develop interesting flow morphologies, such as (i) an array of miniaturized spherical or hemispherical or elongated oil drops in continuous water phase, (ii) "oil-in-water" microemulsion with varying size and shape of oil droplets. The results reported can be of significance in improving the efficiency of multiphase microreactors where the flow patterns composed of droplets are preferred because of the availability of higher interfacial area for reactions or heat and mass exchange. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Modelling of DC electric fields induced by RF sheath in front of ICRF antenna

    International Nuclear Information System (INIS)

    Faudot, E.; Heuraux, S.; Colas, L.

    2003-01-01

    Reducing the ICRF (ion cyclotron range frequency) antenna-plasma interaction is one of the key points for reaching very long tokamak discharges. One problem which limits such discharges, is the appearance of hot spots on the surface of the antenna: Radio Frequency (RF) sheaths modify the properties of the edge plasma by rectifying the RF potential along open magnetic field lines and can induce hot spots. This paper investigates the corrections to sheath potentials introduced by the interactions between adjacent flux tubes. Our theoretical study started from an oscillating double Langmuir probe model, in which a transverse influx of current was included. This model was confronted with 1D PIC simulations along a magnetic field line, and demonstrated that current exchanges can decrease mean potentials. A 2D electrostatic fluid code was then developed, which couples adjacent flux tubes in a poloidal cross section with collisional conductivity or polarization currents. It showed that transverse currents are able to smooth structures smaller than a characteristic size in the sheath potential maps (results for Tore Supra). These computed rectified potentials can be used to obtain the DC electric fields in front of the antenna. And then, it gives an estimate of the particle drift and the energy flux on the antenna structure, which can explain hot spots. (author)

  11. Pulsed DC Electric Field-Induced Differentiation of Cortical Neural Precursor Cells.

    Directory of Open Access Journals (Sweden)

    Hui-Fang Chang

    Full Text Available We report the differentiation of neural stem and progenitor cells solely induced by direct current (DC pulses stimulation. Neural stem and progenitor cells in the adult mammalian brain are promising candidates for the development of therapeutic neuroregeneration strategies. The differentiation of neural stem and progenitor cells depends on various in vivo environmental factors, such as nerve growth factor and endogenous EF. In this study, we demonstrated that the morphologic and phenotypic changes of mouse neural stem and progenitor cells (mNPCs could be induced solely by exposure to square-wave DC pulses (magnitude 300 mV/mm at frequency of 100-Hz. The DC pulse stimulation was conducted for 48 h, and the morphologic changes of mNPCs were monitored continuously. The length of primary processes and the amount of branching significantly increased after stimulation by DC pulses for 48 h. After DC pulse treatment, the mNPCs differentiated into neurons, astrocytes, and oligodendrocytes simultaneously in stem cell maintenance medium. Our results suggest that simple DC pulse treatment could control the fate of NPCs. With further studies, DC pulses may be applied to manipulate NPC differentiation and may be used for the development of therapeutic strategies that employ NPCs to treat nervous system disorders.

  12. Pulsed DC Electric Field-Induced Differentiation of Cortical Neural Precursor Cells.

    Science.gov (United States)

    Chang, Hui-Fang; Lee, Ying-Shan; Tang, Tang K; Cheng, Ji-Yen

    2016-01-01

    We report the differentiation of neural stem and progenitor cells solely induced by direct current (DC) pulses stimulation. Neural stem and progenitor cells in the adult mammalian brain are promising candidates for the development of therapeutic neuroregeneration strategies. The differentiation of neural stem and progenitor cells depends on various in vivo environmental factors, such as nerve growth factor and endogenous EF. In this study, we demonstrated that the morphologic and phenotypic changes of mouse neural stem and progenitor cells (mNPCs) could be induced solely by exposure to square-wave DC pulses (magnitude 300 mV/mm at frequency of 100-Hz). The DC pulse stimulation was conducted for 48 h, and the morphologic changes of mNPCs were monitored continuously. The length of primary processes and the amount of branching significantly increased after stimulation by DC pulses for 48 h. After DC pulse treatment, the mNPCs differentiated into neurons, astrocytes, and oligodendrocytes simultaneously in stem cell maintenance medium. Our results suggest that simple DC pulse treatment could control the fate of NPCs. With further studies, DC pulses may be applied to manipulate NPC differentiation and may be used for the development of therapeutic strategies that employ NPCs to treat nervous system disorders.

  13. Analysis of carrier behavior in C60/P(VDF-TrFE) double-layer capacitor by using electric-field-induced optical second-harmonic generation measurement

    International Nuclear Information System (INIS)

    Cui, Xiaojin; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2013-01-01

    By using displacement current measurement (DCM) and electric-field-induced optical second-harmonic generation (EFISHG) measurement, we studied the carrier behavior in the indium-tin oxide (ITO)/Poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE))/C60/Au(or Al) capacitors. Two DCM peaks appeared asymmetrically at around −35.5 V and +30.0 V in the dark. Correspondingly, the EFISHG response from the C60 layer was observed, but the peak positions were different with respect to DCM ones. The results show that the spontaneous polarization of the ferroelectric P(VDF-TrFE) polymeric layer directly affects the electric field in the C60 layer, and thus governs the carrier motion in this layer. As a result, the C60 layer serves like an insulator in the dark, while electrons and holes are captured and released at the interface in response to the turn-over of spontaneous polarization of ferroelectric layer. On the other hand, under white light illumination, C60 layer serves like a conductor due to the increase of photogenerated mobile carriers, and these carriers dominate the carrier motions therein. Our findings here will be helpful for analyzing carrier behaviors in organic electronic devices using ferroelectric polymers

  14. Analysis of carrier behavior in C60/P(VDF-TrFE) double-layer capacitor by using electric-field-induced optical second-harmonic generation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaojin [Department of Physical Electronics, Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan); State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2013-12-21

    By using displacement current measurement (DCM) and electric-field-induced optical second-harmonic generation (EFISHG) measurement, we studied the carrier behavior in the indium-tin oxide (ITO)/Poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE))/C60/Au(or Al) capacitors. Two DCM peaks appeared asymmetrically at around −35.5 V and +30.0 V in the dark. Correspondingly, the EFISHG response from the C60 layer was observed, but the peak positions were different with respect to DCM ones. The results show that the spontaneous polarization of the ferroelectric P(VDF-TrFE) polymeric layer directly affects the electric field in the C60 layer, and thus governs the carrier motion in this layer. As a result, the C60 layer serves like an insulator in the dark, while electrons and holes are captured and released at the interface in response to the turn-over of spontaneous polarization of ferroelectric layer. On the other hand, under white light illumination, C60 layer serves like a conductor due to the increase of photogenerated mobile carriers, and these carriers dominate the carrier motions therein. Our findings here will be helpful for analyzing carrier behaviors in organic electronic devices using ferroelectric polymers.

  15. In-vivo Imaging of Magnetic Fields Induced by Transcranial Direct Current Stimulation (tDCS) in Human Brain using MRI

    Science.gov (United States)

    Jog, Mayank V.; Smith, Robert X.; Jann, Kay; Dunn, Walter; Lafon, Belen; Truong, Dennis; Wu, Allan; Parra, Lucas; Bikson, Marom; Wang, Danny J. J.

    2016-10-01

    Transcranial direct current stimulation (tDCS) is an emerging non-invasive neuromodulation technique that applies mA currents at the scalp to modulate cortical excitability. Here, we present a novel magnetic resonance imaging (MRI) technique, which detects magnetic fields induced by tDCS currents. This technique is based on Ampere’s law and exploits the linear relationship between direct current and induced magnetic fields. Following validation on a phantom with a known path of electric current and induced magnetic field, the proposed MRI technique was applied to a human limb (to demonstrate in-vivo feasibility using simple biological tissue) and human heads (to demonstrate feasibility in standard tDCS applications). The results show that the proposed technique detects tDCS induced magnetic fields as small as a nanotesla at millimeter spatial resolution. Through measurements of magnetic fields linearly proportional to the applied tDCS current, our approach opens a new avenue for direct in-vivo visualization of tDCS target engagement.

  16. Effect of heavy-metal insertions at Fe/MgO interfaces on electric-field-induced modification of magnetocrystalline anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, K.; Nomura, T. [Department of Physics Engineering, Mie University, Tsu, Mie 514-8507 (Japan); Pradipto, A.-M. [Department of Physics Engineering, Mie University, Tsu, Mie 514-8507 (Japan); Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Nawa, K.; Akiyama, T.; Ito, T. [Department of Physics Engineering, Mie University, Tsu, Mie 514-8507 (Japan)

    2017-05-01

    Magnetocrystalline anisotropy (MCA) at Fe/MgO interfaces with insertions of 3d (Co, Ni), 4d (Ru, Rh, Pd), and 5d (Os, Ir, Pt) elements in external electric fields was investigated from first-principles calculations. The MCA energy and the electric-field-induced MCA modification dramatically depend on the inserted elements. Large MCA modification may be achieved by heavy-metal insertions, in which the strength of spin-orbit coupling of inserted elements and the position of the Fermi level relative to d band level play key roles. - Highlights: • MCA at Fe/MgO interface dramatically depends on insertions of 3d, 4d, and 5d elements. • Large electric-field-induced MCA modification is achieved by heavy-metal insertions. • Position of Fermi level relative to d band level plays key role in determining MCA.

  17. Electric Field Induce Blue Shift and Intensity Enhancement in 2D Exciplex Organic Light Emitting Diodes; Controlling Electron-Hole Separation.

    Science.gov (United States)

    Al Attar, Hameed A; Monkman, Andy P

    2016-09-01

    A simple but novel method is designed to study the characteristics of the exciplex state pinned at a donor-acceptor abrupt interface and the effect an external electric field has on these excited states. The reverse Onsager process, where the field induces blue-shifted emission and increases the efficiency of the exciplex emission as the e-h separation reduces, is discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Electric-field-induced phase transitions in co-doped Pb(Zr1−xTixO3 at the morphotropic phase boundary

    Directory of Open Access Journals (Sweden)

    Daniel J Franzbach

    2014-02-01

    Full Text Available The strain- and polarization-electric field behavior was characterized at room temperature for Pb0.98Ba0.01(Zr1−xTix0.98Nb0.02O3, 0.40 ≤ x ≤ 0.60. The investigated compositions were located in the vicinity of the morphotropic phase boundary, giving insight into the influence of crystal structure on the hysteretic ferroelectric behavior. The remanent strain of particular compositions is shown to be larger than theoretically allowed by ferroelectric switching alone, indicating the presence of additional remanent strain mechanisms. A phenomenological free energy analysis was used to simulate the effect of an applied electric field on the initial equilibrium phase. It is shown that electric-field-induced phase transitions in polycrystalline ferroelectrics can account for the experimental observations. The experimental and simulation results are contrasted to neutron diffraction measurements performed on representative compositions in the virgin and remanent states.

  19. 3D modeling of the total electric field induced by transcranial magnetic stimulation using the boundary element method

    Energy Technology Data Exchange (ETDEWEB)

    Salinas, F S; Lancaster, J L; Fox, P T [Research Imaging Center, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229 (United States)

    2009-06-21

    Transcranial magnetic stimulation (TMS) delivers highly localized brain stimulations via non-invasive externally applied magnetic fields. This non-invasive, painless technique provides researchers and clinicians with a unique tool capable of stimulating both the central and peripheral nervous systems. However, a complete analysis of the macroscopic electric fields produced by TMS has not yet been performed. In this paper, we addressed the importance of the secondary E-field created by surface charge accumulation during TMS using the boundary element method (BEM). 3D models were developed using simple head geometries in order to test the model and compare it with measured values. The effects of tissue geometry, size and conductivity were also investigated. Finally, a realistically shaped head model was used to assess the effect of multiple surfaces on the total E-field. Secondary E-fields have the greatest impact at areas in close proximity to each tissue layer. Throughout the head, the secondary E-field magnitudes typically range from 20% to 35% of the primary E-field's magnitude. The direction of the secondary E-field was generally in opposition to the primary E-field; however, for some locations, this was not the case (i.e. going from high to low conductivity tissues). These findings show that realistically shaped head geometries are important for accurate modeling of the total E-field.

  20. 3D modeling of the total electric field induced by transcranial magnetic stimulation using the boundary element method

    International Nuclear Information System (INIS)

    Salinas, F S; Lancaster, J L; Fox, P T

    2009-01-01

    Transcranial magnetic stimulation (TMS) delivers highly localized brain stimulations via non-invasive externally applied magnetic fields. This non-invasive, painless technique provides researchers and clinicians with a unique tool capable of stimulating both the central and peripheral nervous systems. However, a complete analysis of the macroscopic electric fields produced by TMS has not yet been performed. In this paper, we addressed the importance of the secondary E-field created by surface charge accumulation during TMS using the boundary element method (BEM). 3D models were developed using simple head geometries in order to test the model and compare it with measured values. The effects of tissue geometry, size and conductivity were also investigated. Finally, a realistically shaped head model was used to assess the effect of multiple surfaces on the total E-field. Secondary E-fields have the greatest impact at areas in close proximity to each tissue layer. Throughout the head, the secondary E-field magnitudes typically range from 20% to 35% of the primary E-field's magnitude. The direction of the secondary E-field was generally in opposition to the primary E-field; however, for some locations, this was not the case (i.e. going from high to low conductivity tissues). These findings show that realistically shaped head geometries are important for accurate modeling of the total E-field.

  1. 3D modeling of the total electric field induced by transcranial magnetic stimulation using the boundary element method

    Science.gov (United States)

    Salinas, F. S.; Lancaster, J. L.; Fox, P. T.

    2009-06-01

    Transcranial magnetic stimulation (TMS) delivers highly localized brain stimulations via non-invasive externally applied magnetic fields. This non-invasive, painless technique provides researchers and clinicians with a unique tool capable of stimulating both the central and peripheral nervous systems. However, a complete analysis of the macroscopic electric fields produced by TMS has not yet been performed. In this paper, we addressed the importance of the secondary E-field created by surface charge accumulation during TMS using the boundary element method (BEM). 3D models were developed using simple head geometries in order to test the model and compare it with measured values. The effects of tissue geometry, size and conductivity were also investigated. Finally, a realistically shaped head model was used to assess the effect of multiple surfaces on the total E-field. Secondary E-fields have the greatest impact at areas in close proximity to each tissue layer. Throughout the head, the secondary E-field magnitudes typically range from 20% to 35% of the primary E-field's magnitude. The direction of the secondary E-field was generally in opposition to the primary E-field; however, for some locations, this was not the case (i.e. going from high to low conductivity tissues). These findings show that realistically shaped head geometries are important for accurate modeling of the total E-field.

  2. Current collapse imaging of Schottky gate AlGaN/GaN high electron mobility transistors by electric field-induced optical second-harmonic generation measurement

    International Nuclear Information System (INIS)

    Katsuno, Takashi; Ishikawa, Tsuyoshi; Ueda, Hiroyuki; Uesugi, Tsutomu; Manaka, Takaaki; Iwamoto, Mitsumasa

    2014-01-01

    Two-dimensional current collapse imaging of a Schottky gate AlGaN/GaN high electron mobility transistor device was achieved by optical electric field-induced second-harmonic generation (EFISHG) measurements. EFISHG measurements can detect the electric field produced by carriers trapped in the on-state of the device, which leads to current collapse. Immediately after (e.g., 1, 100, or 800 μs) the completion of drain-stress voltage (200 V) in the off-state, the second-harmonic (SH) signals appeared within 2 μm from the gate edge on the drain electrode. The SH signal intensity became weak with time, which suggests that the trapped carriers are emitted from the trap sites. The SH signal location supports the well-known virtual gate model for current collapse.

  3. Electric-Field-Induced Energy Tuning of On-Demand Entangled-Photon Emission from Self-Assembled Quantum Dots.

    Science.gov (United States)

    Zhang, Jiaxiang; Zallo, Eugenio; Höfer, Bianca; Chen, Yan; Keil, Robert; Zopf, Michael; Böttner, Stefan; Ding, Fei; Schmidt, Oliver G

    2017-01-11

    We explore a method to achieve electrical control over the energy of on-demand entangled-photon emission from self-assembled quantum dots (QDs). The device used in our work consists of an electrically tunable diode-like membrane integrated onto a piezoactuator, which is capable of exerting a uniaxial stress on QDs. We theoretically reveal that, through application of the quantum-confined Stark effect to QDs by a vertical electric field, the critical uniaxial stress used to eliminate the fine structure splitting of QDs can be linearly tuned. This feature allows experimental realization of a triggered source of energy-tunable entangled-photon emission. Our demonstration represents an important step toward realization of a solid-state quantum repeater using indistinguishable entangled photons in Bell state measurements.

  4. radiation and electric field induced effects on the order-disorder phase in lithium sodium sulphate crystals

    Science.gov (United States)

    Hamed, A. E.; Kassem, M. E.; El-Wahidy, E. F.; El-Abshehy, M. A.

    1995-03-01

    The temperature dependence of specific heat at constant pressure, Cp(T), has been measured for lithium sodium sulphate, LiNaSo4 crystals, at different ?-radiation doses and external bias electric field (Eb), in the temperature range 300-900 K. A nonlinear dependence of transition temperature, T1 and a remarkable change in the thermodynamic parameters, were obtained as the effect of both electric field and ?-radiation. The effect of ?-radiation doses on the phase transition in LiNaSO4 crystals was explained as due to an internal bias field, Eb, originating from the interaction of polar defects with the order parameter of the host lattice. The internal bias field effect on the behaviour of Cp(T) in LiNaSO4 crystals was similar to that of the external electric field (E).

  5. Analysis of current-voltage characteristics of Au/pentacene/fluorine polymer/indium zinc oxide diodes by electric-field-induced optical second-harmonic generation

    Energy Technology Data Exchange (ETDEWEB)

    Nishi, Shohei; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 S3-33, O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2015-06-28

    By using electric-field-induced optical second-harmonic generation measurement coupled with the conventional current-voltage (I-V) measurement, we studied the carrier transport of organic double-layer diodes with a Au/pentacene/fluorine polymer (FP)/indium zinc oxide (IZO) structure. The rectifying I-V characteristics were converted into the I-E characteristics of the FP and pentacene layers. Results suggest a model in which Schottky-type electron injection from the IZO electrode to the FP layer governs the forward electrical conduction (V > 0), where the space charge electric field produced in the FP layer by accumulated holes at the pentacene/FP interface makes a significant contribution. On the other hand, Schottky-type injection by accumulated interface electrons from the pentacene layer to the FP layer governs the backward electrical conduction (V < 0). The electroluminescence generated from the pentacene layer in the region V > 0 verifies the electron transport across the FP layer, and supports the above suggested model.

  6. Analysis of current-voltage characteristics of Au/pentacene/fluorine polymer/indium zinc oxide diodes by electric-field-induced optical second-harmonic generation

    International Nuclear Information System (INIS)

    Nishi, Shohei; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2015-01-01

    By using electric-field-induced optical second-harmonic generation measurement coupled with the conventional current-voltage (I-V) measurement, we studied the carrier transport of organic double-layer diodes with a Au/pentacene/fluorine polymer (FP)/indium zinc oxide (IZO) structure. The rectifying I-V characteristics were converted into the I-E characteristics of the FP and pentacene layers. Results suggest a model in which Schottky-type electron injection from the IZO electrode to the FP layer governs the forward electrical conduction (V > 0), where the space charge electric field produced in the FP layer by accumulated holes at the pentacene/FP interface makes a significant contribution. On the other hand, Schottky-type injection by accumulated interface electrons from the pentacene layer to the FP layer governs the backward electrical conduction (V < 0). The electroluminescence generated from the pentacene layer in the region V > 0 verifies the electron transport across the FP layer, and supports the above suggested model

  7. Intense picosecond pulsed electric fields induce apoptosis through a mitochondrial-mediated pathway in HeLa cells

    Science.gov (United States)

    HUA, YUAN-YUAN; WANG, XIAO-SHU; ZHANG, YU; YAO, CHEN-GUO; ZHANG, XI-MING; XIONG, ZHENG-AI

    2012-01-01

    The application of pulsed electric fields (PEF) is emerging as a new technique for tumor therapy. Picosecond pulsed electric fields (psPEF) can be transferred to target deep tissue non-invasively and precisely, but the research of the biological effects of psPEF on cells is limited. Electric theory predicts that intense psPEF will target mitochondria and lead to changes in transmembrane potential, therefore, it is hypothesized that it can induce mitochondrial-mediated apoptosis. HeLa cells were exposed to psPEF in this study to investigate this hypothesis. MTT assay demonstrated that intense psPEF significantly inhibited the proliferation of HeLa cells in a dose-dependent manner. Typical characteristics of apoptosis in HeLa cells were observed, using transmission electron microscopy. Loss of mitochondrial transmembrane potential was explored using laser scanning confocal microscopy with Rhodamine-123 (Rh123) staining. Furthermore, the mitochondrial apoptotic events were also confirmed by western blot analysis for the release of cytochrome C and apoptosis-inducing factor from mitochondria into the cytosol. In addition, activation of caspase-3, caspase-9, upregulation of Bax, p53 and downregulation of Bcl-2 were observed in HeLa cells also indicating apoptosis. Taken together, these results demonstrate that intense psPEF induce cell apoptosis through a mitochondrial-mediated pathway. PMID:22307872

  8. Strain and electric field induced metallization in the GaX (X = N, P, As & Sb) monolayer

    Science.gov (United States)

    Bahuguna, Bhagwati Prasad; Saini, L. K.; Sharma, Rajesh O.; Tiwari, Brajesh

    2018-05-01

    We investigate the strain and electric field dependent electronic properties of two dimensional Ga-based group III-V monolayer from the first-principles approach within density functional theory. The energy bandgap of GaX monolayer increases upto the certain value of compressive strain and then decreases. On the other hand, the energy bandgap of GaX monolayer is monotonically decreased with increasing tensile strain and become metallic at the higher value. Furthermore, the perpendicular electric field decreases the energy band gap of unstrained GaX monolayer and shows semiconductor to metal transition. These results suggest that the nature of energy bands and value of energy bandgap in GaX monolayer can be tuned by the biaxial mechanical strain or perpendicular electrical field. Additionally, we have also studied the optical response of unstrained GaX monolayer in term of optical conductivity. These findings may provide valuable information to develop the Ga-based optoelectronic devices and further the understanding of the GaX monolayer.

  9. A DFT analysis of the adsorption of nitrogen oxides on Fe-doped graphene, and the electric field induced desorption

    Science.gov (United States)

    Cortés-Arriagada, Diego; Villegas-Escobar, Nery

    2017-10-01

    Density functional theory calculations were carried out to study the adsorption and sensing properties of Fe-doped graphene nanosheets (FeG) toward nitrogen oxides (NO, NO2, and N2O). The results indicated the adsorption of nitrogen oxides is significantly increased onto FeG compared to pristine graphene, reaching adsorption energies of 1.1-2.2 eV, even with a high stability at room temperature. As a result of the larger charge transfer and strong chemical binding, the bandgap of the adsorbent-adsorbate systems is increased in up to 0.5 eV with respect to the free FeG, indicating that FeG is highly sensitive to nitrogen oxides. It was also evidenced the adsorption and sensing properties remain even in the presence of O2 currents for N2O, where a co-adsorption mechanism was analyzed. Besides, NO2 is capable to induce the largest magnetization of FeG. Finally, positive electric fields of at least 0.04 a.u. decrease the stability of the adsorbent-adsorbate interactions, inducing the desorption process. Therefore, FeG emerges as a promising low-dimensional material with excellent adsorption and sensing properties to be applied in solid state sensors of nitrogen oxides, where electric fields can be used as a strategy for the FeG reactivation in repetitive sensing applications.

  10. Electric-field induced surface instabilities of soft dielectrics and their effects on optical transmittance and scattering

    Science.gov (United States)

    Shian, Samuel; Kjeer, Peter; Clarke, David R.

    2018-03-01

    When a voltage is applied to a percolative, mechanically compliant mat of carbon nanotubes (CNTs) on a smooth elastomer bilayer attached to an ITO coated glass substrate, the in-line optical transmittance decreases with increasing voltage. Two regimes of behavior have been identified based on optical scattering, bright field optical microscopy, and confocal optical microscopy. In the low field regime, the electric field produces a spatially inhomogeneous surface deformation of the elastomer that causes local variations in optical refraction and modulates the light transmittance. The spatial variation is associated with the distribution of the CNTs over the surface. At higher fields, above a threshold voltage, an array of pits in the surface form by a nucleation and growth mechanism and these also scatter light. The formation of pits, and creases, in the thickness of the elastomer, is due to a previously identified electro-mechanical surface instability. When the applied voltage is decreased from its maximum, the transmittance returns to its original value although there is a transmittance hysteresis and a complicated time response. When the applied voltage exceeds the threshold voltage, there can be remnant optical contrast associated with creasing of the elastomer and the recovery time appears to be dependent on local jamming of CNTs in areas where the pits formed. A potential application of this work as an electrically tunable privacy window or camouflaging devices is demonstrated.

  11. A parametric study of AC electric field-induced toroidal vortex formation in laminar nonpremixed coflow flames

    KAUST Repository

    Xiong, Yuan

    2017-05-02

    This study presents an experimental work investigating the controlling parameters on the formation of an electrically-induced inner toroidal vortex (ITV) near a nozzle rim in small, laminar nonpremixed coflow flames, when an alternating current is applied to the nozzle. A systematic parametric study was conducted by varying the flow parameters of the fuel and coflowing-air velocities, and the nozzle diameter. The fuels tested were methane, ethylene, ethane, propane, n-butane, and i-butane, each representing different ion-generation characteristics and sooting tendencies. The results showed that the fluid dynamic effects on ITV formation were weak, causing only mild variation when altering flow velocities. However, increased fuel velocity resulted in increased polycyclic aromatic hydrocarbon (PAH) formation, which promoted ITV formation. When judging the ITV-formation tendency based on critical applied voltage and frequency, it was qualitatively well correlated with the PAH concentration and the relative location of PAHs to the nozzle rim. The sooting tendency of the fuels did not affect the results much. A change in the nozzle diameter highlighted the importance of the relative distance between the PAH zone and the nozzle rim, indicating the role of local electric-field intensity on ITV formation. Detailed onset conditions, characteristics of near-nozzle flow patterns, and PAH distributions are also discussed.

  12. Electrical-field-induced magnetic Skyrmion ground state in a two-dimensional chromium tri-iodide ferromagnetic monolayer

    Science.gov (United States)

    Liu, Jie; Shi, Mengchao; Mo, Pinghui; Lu, Jiwu

    2018-05-01

    Using fully first-principles non-collinear self-consistent field density functional theory (DFT) calculations with relativistic spin-orbital coupling effects, we show that, by applying an out-of-plane electrical field on a free-standing two-dimensional chromium tri-iodide (CrI3) ferromagnetic monolayer, the Néel-type magnetic Skyrmion spin configurations become more energetically-favorable than the ferromagnetic spin configurations. It is revealed that the topologically-protected Skyrmion ground state is caused by the breaking of inversion symmetry, which induces the non-trivial Dzyaloshinskii-Moriya interaction (DMI) and the energetically-favorable spin-canting configuration. Combining the ferromagnetic and the magnetic Skyrmion ground states, it is shown that 4-level data can be stored in a single monolayer-based spintronic device, which is of practical interests to realize the next-generation energy-efficient quaternary logic devices and multilevel memory devices.

  13. Electric field-induced phase transitions and composition-driven nanodomains in rhombohedral-tetragonal potassium-sodium niobate-based ceramics

    KAUST Repository

    Lv, Xiang

    2017-08-07

    The mechanisms behind the high piezoelectricity of (K,Na)NbO3-based lead-free ceramics were investigated, including electric field-induced phase transitions and composition-driven nanodomains. The construction of a rhombohedral-tetragonal (R-T) phase boundary, confirmed using several advanced techniques, allowed a large piezoelectric constant (d33) of 450 ± 5 pC/N to be obtained in (1-x)K0.4Na0.6Nb0.945Sb0.055O3-xBi0.5Na0.5(Hf1-ySny)O3 (0 ≤ x ≤ 0.06 and 0 ≤ y ≤ 0.5) ceramics possessing an ultralow ΔUT-R of 7.4 meV. More importantly, the existence of an intermediate phase, i.e., the electric-induced phase (EIP), bridging the rhombohedral R [Ps//(111)] and tetragonal T [Ps//(001)] phases during the polarization rotation was demonstrated. Striped nanodomains (∼40 nm) that easily responded to external stimulation were also observed in the ceramics with an R-T phase. Thus, the enhanced piezoelectric properties originated from EIP and the striped nanodomains.

  14. Electrochemistry of 2-dimethylaminoethanethiol SAM on gold electrode: Interaction with SWCNT-poly(m-aminobenzene sulphonic acid), electric field-induced protonation-deprotonation, and surface pKa

    CSIR Research Space (South Africa)

    Pillay, J

    2009-06-01

    Full Text Available -called electric field induced protonation-deprotonation process, hitherto observed for the -COOH terminated SAMs, is also observed for the -N(H)+(CH3)2 terminated. The surface pKa of DMAET was estimated as 7.6, smaller than its solution pKa of 10.8. It is also...

  15. Analysis of interfacial energy states in Au/pentacene/polyimide/indium-zinc-oxide diodes by electroluminescence spectroscopy and electric-field-induced optical second-harmonic generation measurement

    Science.gov (United States)

    Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2016-03-01

    By using electroluminescence (EL) spectroscopy and electric-field-induced optical second-harmonic generation (EFISHG) measurement, we analyzed interfacial energy states in Au/pentacene/polyimide/indium-zinc-oxide (IZO) diodes, to characterize the pentacene/polyimide interface. Under positive voltage application to the Au electrode with reference to the IZO electrode, the EFISHG showed that holes are injected from Au electrode, and accumulate at the pentacene/polyimide interface with the surface charge density of Qs = 3.8 × 10-7 C/cm2. The EL spectra suggested that the accumulated holes are not merely located in the pentacene but they are transferred to the interface states of polyimide. These accumulated holes distribute with the interface state density greater than 1012 cm-2 eV-1 in the range E = 1.5-1.8 and 1.7-2.4 eV in pentacene and in polyimide, respectively, under assumption that accumulated holes govern recombination radiation. The EL-EFISHG measurement is helpful to characterize organic-organic layer interfaces in organic devices and provides a way to analyze interface energy states.

  16. The relationship between the electric field induced dissociation of charge transfer (CT) excitons and the photocurrent in novel hybrid small molecular/polymeric solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Inal, Sahika; Neher, Dieter [Universitaet Potsdam (Germany). Institut fuer Physik und Astronomie; Sellinger, Alan [Institute of Materials Research and Engineering, Singapore (China)

    2010-07-01

    Complete dissociation of coulombically bound interfacial states is an ultimate step accounting for photovoltaic performance. Recent work has proposed that the emission of CT-exciton, i.e. an exciplex, is a competing process to the generation of free charges. Here, we investigated the photophysical processes in a bulk heterojunction system using a soluble poly(p-phenylenevinylene) donor and a novel small molecular electron acceptor based on Vinazene (2-vinyl-4,5-dicyanoimidazole). Recent work has shown that this blend exhibits a featureless emission, prominent at long wavelengths of the spectrum, which was attributed to a CT-exciton. We monitored the field induced dissociation of these CT-excitons by means of steady state and time resolved PL spectroscopy. Shortened decay times and reduced PL emission in blend film evidence the dissociation of the emissive intermolecular pair by the external electric field. Analyzing the dependence of the photocurrent and external quantum efficiency on the external field, the fate of the separated exciplex pairs is tackled. It is suggested that the formation of free carriers involves channels other than CT-excitons in such blends.

  17. Electric field-induced phase transitions in Li-modified Na{sub 0.5}K{sub 0.5}NbO{sub 3} at the polymorphic phase boundary

    Energy Technology Data Exchange (ETDEWEB)

    Iamsasri, Thanakorn; Jones, Jacob L., E-mail: jacobjones@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Tutuncu, Goknur [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Uthaisar, Chunmanus; Pojprapai, Soodkhet [School of Ceramic Engineering, Institute of Engineering, Suranaree University of Technology, Nakorn Ratchasima 30000 (Thailand); Wongsaenmai, Supattra [Program in Materials Science, Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand)

    2015-01-14

    The electric field-induced phase transitions in Li-modified Na{sub 0.5}K{sub 0.5}NbO{sub 3} at the polymorphic phase boundary (PPB) were observed using in situ X-ray diffraction. The ratio of monoclinic to tetragonal phase fraction was used as an indicator of the extent and reversibility of the phase transitions. The reversibility of the phase transition was greater in compositions further from the PPB. These results demonstrate that the field-induced phase transition is one of the origins of high piezoelectric properties in lead-free ferroelectric materials.

  18. Effects of electric-field-induced piezoelectric strain on the electronic transport properties of La0.9Ce0.1MnO3 thin films

    International Nuclear Information System (INIS)

    Zheng, R.K.; Dong, S.N.; Wu, Y.Q.; Zhu, Q.X.; Wang, Y.; Chan, H.L.W.; Li, X.M.; Luo, H.S.; Li, X.G.

    2012-01-01

    The authors constructed multiferroic structures by growing La 0.9 Ce 0.1 MnO 3 (LCEMO) thin films on piezoelectric 0.68Pb(Mg 1/3 Nb 2/3 )O 3 –0.32PbTiO 3 (PMN-PT) single-crystal substrates. Due to the efficient elastic coupling at the interface, the electric-field-induced piezoelectric strain in PMN-PT substrates is effectively transferred to LCEMO films and thus, leads to a decrease in the resistance and an increase in the magnetoresistance of the films. Particularly, it was found that the resistance-strain coefficient [(ΔR/R) film /(Δε zz ) film ] of the LCEMO film was considerably enhanced by the application of magnetic fields, demonstrating strong coupling between the lattice and the spin degrees of freedom. (ΔR/R) film /(Δε zz ) film at 122 K was enhanced by ∼ 28.8% by a magnetic field of 1.2 T. An analysis of the overall results demonstrates that the phase separation is crucial to understand strain-mediated modulation of electronic transport properties of manganite film/PMN-PT multiferroic structures. - Highlights: ► La 0.9 Ce 0.1 Mn O3 films were epitaxially grown on piezoelectric single crystals. ► Piezoelectric strain influences the electronic transport properties of films. ► Magnetic field enhances the piezoelectric strain effect. ► Phase separation is crucial to understand the piezoelectric strain effect.

  19. First-principles calculations on strain and electric field induced band modulation and phase transition of bilayer WSe2sbnd MoS2 heterostructure

    Science.gov (United States)

    Lei, Xiang; Yu, Ke

    2018-04-01

    A purposeful modulation of physical properties of material via change external conditions has long captured people's interest and can provide many opportunities to improve the specific performance of electronic devices. In this work, a comprehensive first-principles survey was performed to elucidate that the bandgap and electronic properties of WSe2sbnd MoS2 heterostructure exhibited unusual response to exterior strain and electric field in comparison with pristine structures. It demonstrates that the WSe2sbnd MoS2 is a typical type-II heterostructure, and thus the electron-hole pairs can be effectively spatially separated. The external effects can trigger the electronic phase transition from semiconducting to metallic state, which originates from the internal electric evolution induced energy-level shift. Interestingly, the applied strain shows no direction-depended character for the modulation of bandgap of WSe2sbnd MoS2 heterostructure, while it exists in the electric field tuning processes and strongly depends on the direction of the electric field. Our findings elucidate the tunable electronic property of bilayer WSe2sbnd MoS2 heterostructure, and would provide a valuable reference to design the electronic nanodevices.

  20. 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.

  1. 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.

  2. Electric field-induced ferromagnetic resonance in a CoFeB/MgO magnetic tunnel junction under dc bias voltages

    Science.gov (United States)

    Kanai, Shun; Gajek, Martin; Worledge, D. C.; Matsukura, Fumihiro; Ohno, Hideo

    2014-12-01

    We measure homodyne-detected ferromagnetic resonance (FMR) induced by the electric-field effect in a CoFeB/MgO/CoFeB magnetic tunnel junction (MTJ) with perpendicular magnetic easy axis under dc bias voltages up to 0.1 V. From the bias dependence of the resonant frequency, we find that the first order perpendicular magnetic anisotropy is modulated by the applied electric field, whereas the second order component is virtually independent of the electric field. The lineshapes of the FMR spectra are bias dependent, which are explained by the combination of electric-field effect and reflection of the bias voltage from the MTJ.

  3. Characteristics of anomalous Hall effect in spin-polarized two-dimensional electron gases in the presence of both intrinsic, extrinsic, and external electric-field induced spin—orbit couplings

    International Nuclear Information System (INIS)

    Liu Song; Yan Yu-Zhen; Hu Liang-Bin

    2012-01-01

    The various competing contributions to the anomalous Hall effect in spin-polarized two-dimensional electron gases in the presence of both intrinsic, extrinsic and external electric-field induced spin—orbit coupling were investigated theoretically. Based on a unified semiclassical theoretical approach, it is shown that the total anomalous Hall conductivity can be expressed as the sum of three distinct contributions in the presence of these competing spin—orbit interactions, namely an intrinsic contribution determined by the Berry curvature in the momentum space, an extrinsic contribution determined by the modified Bloch band group velocity and an extrinsic contribution determined by spin—orbit-dependent impurity scattering. The characteristics of these competing contributions are discussed in detail in the paper. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  4. Field-induced optically isotropic state in bent core nematic liquid crystals: unambiguous proof of field-induced optical biaxiality

    International Nuclear Information System (INIS)

    Elamain, Omaima; Komitov, Lachezar; Hegde, Gurumurthy; Fodor-Csorba, Katalin

    2013-01-01

    The behaviour of bent core (BC) nematic liquid crystals was investigated under dc applied electric field. The optically isotropic state of a sample containing BC nematic was observed under application of low dc electric fields. The quality of the dark state when the sample was inserted between two crossed polarizers was found to be superb and it did not change when rotating the sample between the polarizers. The coupling between the net molecular dipole moment and the applied dc electric field was considered as the origin of the out-of-plane switching of the BC molecules resulting in switching from the field-off bright state to the field-on dark state. The field-induced optically isotropic state is an unambiguous proof of the field-induced biaxiality in the BC nematic liquid crystal. A simple model explaining the appearance of the isotropic optical state in BC nematics and the switching of the sample slow axis between three mutually orthogonal directions under dc applied electric field is proposed. (paper)

  5. Electric-field-induced local structural phenomena in relaxor ferroelectric PbSc0.5Nb0.5O3 near the intermediate temperature T* studied by Raman spectroscopy

    International Nuclear Information System (INIS)

    Steilmann, T; Maier, B J; Bismayer, U; Mihailova, B; Gospodinov, M

    2014-01-01

    Raman spectroscopy at different temperatures and under an external electric field E was applied to PbSc 0.5 Nb 0.5 O 3 single crystals in order to gain further insights into the mesoscopic-scale coupling processes in perovskite-type (ABO 3 ) relaxor ferroelectrics. Parallel and cross-polarized Raman spectra were collected between 800–80 K with E applied along the cubic [1 0 0], [1 1 0] or [1 1 1] crystallographic directions. The analysis was focused on the field-induced changes in the temperature evolution of three low-energy phonon modes: the Pb-localized mode near 50 cm −1 , the Pb-BO 3 translation mode near 150 cm −1 , and the B-cation-localized mode near 250 cm −1 . The results show that competitive ferroelectric (FE) and antiferroelectric (AFE) coupling exists within the system of off-centred Pb 2+ cations, within the system of off-centred B-site cations as well as between off-centred Pb 2+ and B-site cations. The strong AFE-type coupling between Pb 2+ cations along the cubic body diagonal significantly influences the coupling between the B-site cations via the Pb-BO 3 mode and results in AFE-type behaviour of the ‘microscopic’ T* determined from the B-cation-localized mode near 250 cm −1 , which explains the previously reported non-trivial field dependence of the ‘macroscopic’ characteristic temperatures: the temperature of the dielectric-permittivity maximum T m , T*, and the Burns temperature T B . The comparative analysis between PbSc 0.5 Nb 0.5 O 3 and PbSc 0.5 Ta 0.5 O 3 indicates that two major displacive order parameters couple to form a relaxor state in B-site complex perovskites: the FE order associated with polar shifts of B-site cations and the AFE order associated with polar shifts of A-site cations. The latter penetrates through both polar and non-polar regions, but it is highly frustrated due to the high density of translation-symmetry faults in the chemical NaCl-type B-site order. The frustrated AFE order

  6. Direct electrical heating of irradiated metal fuel

    International Nuclear Information System (INIS)

    Fenske, G.R.; Emerson, J.E.; Savoie, F.E.; Johanson, E.W.

    1985-01-01

    The Integral Fast Reactor (IFR) concept proposed by Argonne National Laboratory utilizes a metal fuel core. Reactor safety analysis requires information on the potential for fuel axial expansion during severe thermal transients. In addition to a comparatively large thermal expansion coefficient, metallic fuel has a unique potential for enhanced pre-failure expansion driven by retained fission gas and ingested bond sodium. In this paper, the authors present preliminary results from three direct electrical heating (DEH) experiments performed on irradiated metal fuel to investigate axial expansion behavior. The test samples were from Experimental Breeder Reactor II (EBR-II) driver fuel ML-11 irradiated to 8 at.% burnup. Preliminary analysis of the results suggest that enhanced expansion driven by trapped fission gas can occur

  7. Estimates of peak electric fields induced by Transcranial magnetic stimulation in pregnant women as patients using an FEM full-body model.

    Science.gov (United States)

    Yanamadala, J; Noetscher, G M; Makarov, S N; Pascual-Leone, A

    2017-07-01

    Transcranial magnetic stimulation (TMS) for treatment of depression during pregnancy is an appealing alternative to fetus-threatening drugs. However, no studies to date have been performed that evaluate the safety of TMS for a pregnant mother patient and her fetus. A full-body FEM model of a pregnant woman with about 100 tissue parts has been developed specifically for the present study. This model allows accurate computations of induced electric field in every tissue given different locations of a shape-eight coil, a biphasic pulse, common TMS pulse durations, and using different values of the TMS intensity measured in SMT (Standard Motor Threshold) units. Our simulation results estimate the maximum peak values of the electric field in the fetal area for every fetal tissue separately and for the TMS intensity of one SMT unit.

  8. Influence of Pentacene Interface Layer in ITO/α-NPD/Alq3/Al Organic Light Emitting Diodes by Time-Resolved Electric-Field-Induced Optical Second-Harmonic Generation Measurement.

    Science.gov (United States)

    Oda, Yoshiaki; Sadakata, Atsuo; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2016-04-01

    By using I-V, EL-V, displacement current measurement (DCM) and time-resolved electric-field-induced optical second-harmonic generation (TR-EFISHG) measurement, we studied the influence of interface pentacene layer inserted between ITO and a-NPD layers in ITO/α-NPD/Alq3/Al OLEDs. All experiments were carried out for the OLEDs with and without a pentacene interface layer. The I-V and EL-V measurements showed the decrease of operating voltage of EL, the DCM showed the lowering of inception voltage of carrier injection by inserting a pentacene interface layer. The TR-EFISHG measurement showed the faster accumulation of holes at the interface between the a-NPD and Alq3 layers, which resulted in the relaxation of electric field of a-NPD layer accomplished by the increase of the conductivity and the increase of the electric field in the Alq3 layer. We conclude that TR-EFISHG measurement is helpful for understanding I-V and EL-V characteristics, and can be combined with other methods to give significant information which are impacted by the interface layer.

  9. Domain configuration changes under electric field-induced antiferroelectric-ferroelectric phase transitions in NaNbO3-based ceramics

    International Nuclear Information System (INIS)

    Guo, Hanzheng; Randall, Clive A.; Shimizu, Hiroyuki; Mizuno, Youichi

    2015-01-01

    We recently developed a feasible crystal chemistry strategy to stabilize the antiferroelectricity in NaNbO 3 through a chemical substitution to decrease the tolerance factor and increase the average electronegativity of the system [Shimizu et al., Dalton Trans. 44, 10763 (2015) and Guo et al., J. Appl. Phys. 117, 214103 (2015)]. Two novel lead-free antiferroelectric (AFE) solid solutions, (1-x)NaNbO 3 -xCaZrO 3 and (1-x)NaNbO 3 -xSrZrO 3 , have been found to exhibit the double polarization hysteresis typical of a reversible AFE ↔ ferroelectric (FE) phase transition. In this study, as demonstrated by (1-x)NaNbO 3 -xCaZrO 3 system, the influence of chemical modification and electrical poling on the AFE/FE phase stability was investigated, primarily focusing on the microstructural and crystallographic evolutions. Together with the macroscopic polarization hysteresis measurements, a well-demonstrated structure-property relationship was presented. It was found that the CaZrO 3 substitution into NaNbO 3 can effectively destabilize the FE Q phase and correspondingly lead to a spontaneous reverting to AFE P phase. In contrast to the reversible AFE ↔ FE phase transition, the domain morphology evolution exhibits irreversible nature with a growing process of the orientational domains after applying electric field. Moreover, a multiple-zone axes electron diffraction map of P and Q phases has been summarized and is believed to be an efficient diagram to determine the AFE/FE nature of the NaNbO 3 -based systems

  10. Nanosecond pulsed electric fields induce poly(ADP-ribose) formation and non-apoptotic cell death in HeLa S3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Morotomi-Yano, Keiko; Akiyama, Hidenori [Institute of Pulsed Power Science, Kumamoto University, Kumamoto 860-8555 (Japan); Yano, Ken-ichi, E-mail: yanoken@kumamoto-u.ac.jp [Priority Organization for Innovation and Excellence, Kumamoto University, Kumamoto 860-8555 (Japan)

    2013-08-30

    Highlights: •Nanosecond pulsed electric field (nsPEF) is a new and unique means for life sciences. •Apoptosis was induced by nsPEF exposure in Jurkat cells. •No signs of apoptosis were detected in HeLa S3 cells exposed to nsPEFs. •Formation of poly(ADP-ribose) was induced in nsPEF-exposed HeLa S3 cells. •Two distinct modes of cell death were activated by nsPEF in a cell-dependent manner. -- Abstract: Nanosecond pulsed electric fields (nsPEFs) have recently gained attention as effective cancer therapy owing to their potency for cell death induction. Previous studies have shown that apoptosis is a predominant mode of nsPEF-induced cell death in several cell lines, such as Jurkat cells. In this study, we analyzed molecular mechanisms for cell death induced by nsPEFs. When nsPEFs were applied to Jurkat cells, apoptosis was readily induced. Next, we used HeLa S3 cells and analyzed apoptotic events. Contrary to our expectation, nsPEF-exposed HeLa S3 cells exhibited no molecular signs of apoptosis execution. Instead, nsPEFs induced the formation of poly(ADP-ribose) (PAR), a hallmark of necrosis. PAR formation occurred concurrently with a decrease in cell viability, supporting implications of nsPEF-induced PAR formation for cell death. Necrotic PAR formation is known to be catalyzed by poly(ADP-ribose) polymerase-1 (PARP-1), and PARP-1 in apoptotic cells is inactivated by caspase-mediated proteolysis. Consistently, we observed intact and cleaved forms of PARP-1 in nsPEF-exposed and UV-irradiated cells, respectively. Taken together, nsPEFs induce two distinct modes of cell death in a cell type-specific manner, and HeLa S3 cells show PAR-associated non-apoptotic cell death in response to nsPEFs.

  11. Nanosecond pulsed electric fields induce poly(ADP-ribose) formation and non-apoptotic cell death in HeLa S3 cells

    International Nuclear Information System (INIS)

    Morotomi-Yano, Keiko; Akiyama, Hidenori; Yano, Ken-ichi

    2013-01-01

    Highlights: •Nanosecond pulsed electric field (nsPEF) is a new and unique means for life sciences. •Apoptosis was induced by nsPEF exposure in Jurkat cells. •No signs of apoptosis were detected in HeLa S3 cells exposed to nsPEFs. •Formation of poly(ADP-ribose) was induced in nsPEF-exposed HeLa S3 cells. •Two distinct modes of cell death were activated by nsPEF in a cell-dependent manner. -- Abstract: Nanosecond pulsed electric fields (nsPEFs) have recently gained attention as effective cancer therapy owing to their potency for cell death induction. Previous studies have shown that apoptosis is a predominant mode of nsPEF-induced cell death in several cell lines, such as Jurkat cells. In this study, we analyzed molecular mechanisms for cell death induced by nsPEFs. When nsPEFs were applied to Jurkat cells, apoptosis was readily induced. Next, we used HeLa S3 cells and analyzed apoptotic events. Contrary to our expectation, nsPEF-exposed HeLa S3 cells exhibited no molecular signs of apoptosis execution. Instead, nsPEFs induced the formation of poly(ADP-ribose) (PAR), a hallmark of necrosis. PAR formation occurred concurrently with a decrease in cell viability, supporting implications of nsPEF-induced PAR formation for cell death. Necrotic PAR formation is known to be catalyzed by poly(ADP-ribose) polymerase-1 (PARP-1), and PARP-1 in apoptotic cells is inactivated by caspase-mediated proteolysis. Consistently, we observed intact and cleaved forms of PARP-1 in nsPEF-exposed and UV-irradiated cells, respectively. Taken together, nsPEFs induce two distinct modes of cell death in a cell type-specific manner, and HeLa S3 cells show PAR-associated non-apoptotic cell death in response to nsPEFs

  12. Nanosecond pulsed electric fields induce poly(ADP-ribose) formation and non-apoptotic cell death in HeLa S3 cells.

    Science.gov (United States)

    Morotomi-Yano, Keiko; Akiyama, Hidenori; Yano, Ken-ichi

    2013-08-30

    Nanosecond pulsed electric fields (nsPEFs) have recently gained attention as effective cancer therapy owing to their potency for cell death induction. Previous studies have shown that apoptosis is a predominant mode of nsPEF-induced cell death in several cell lines, such as Jurkat cells. In this study, we analyzed molecular mechanisms for cell death induced by nsPEFs. When nsPEFs were applied to Jurkat cells, apoptosis was readily induced. Next, we used HeLa S3 cells and analyzed apoptotic events. Contrary to our expectation, nsPEF-exposed HeLa S3 cells exhibited no molecular signs of apoptosis execution. Instead, nsPEFs induced the formation of poly(ADP-ribose) (PAR), a hallmark of necrosis. PAR formation occurred concurrently with a decrease in cell viability, supporting implications of nsPEF-induced PAR formation for cell death. Necrotic PAR formation is known to be catalyzed by poly(ADP-ribose) polymerase-1 (PARP-1), and PARP-1 in apoptotic cells is inactivated by caspase-mediated proteolysis. Consistently, we observed intact and cleaved forms of PARP-1 in nsPEF-exposed and UV-irradiated cells, respectively. Taken together, nsPEFs induce two distinct modes of cell death in a cell type-specific manner, and HeLa S3 cells show PAR-associated non-apoptotic cell death in response to nsPEFs. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Electric Field-Induced Large Strain in Ni/Sb-co Doped (Bi0.5Na0.5) TiO3-Based Lead-Free Ceramics

    Science.gov (United States)

    Li, Liangliang; Hao, Jigong; Xu, Zhijun; Li, Wei; Chu, Ruiqing

    2018-02-01

    Lead-free piezoelectric ceramics (Bi0.5Na0.5)0.935Ba0.065Ti1- x (Ni0.5Sb0.5) x O3 (BNBT6.5- xNS) have been fabricated using conventional solid sintering technique. The effect of (Ni, Sb) doping on the phase structure and electrical properties of BNBT6.5 ceramics were systematically investigated. Results show that the addition of (Ni, Sb) destroyed the ferroelectric long-range order of BNBT6.5 and shifted the ferroelectric-relaxor transition temperature ( T F-R) down to room temperature. Thus, this process induced an ergodic relaxor phase at zero field in samples with x = 0.005. Under the electric field, the ergodic relaxor phase could reversibly transform to ferroelectric phase, which promotes the strain response with peak value of 0.38% (at 80 kV/cm, corresponding to d 33 * = 479 pm/V) at x = 0.005. Temperature-dependent measurements of both polarization and strain confirmed that the large strain originated from a reversible field-induced ergodic relaxor to ferroelectric phase transformation. The proposed material exhibits potential for nonlinear actuators.

  14. 78 FR 56594 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2013-09-13

    ... Airworthiness Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA... General Electric Company (GE) GE90-76B, -85B, -90B, -94B, -110B1, and - 115B turbofan engines. This AD was...) Applicability This AD applies to General Electric Company (GE): (1) GE90-76B, -85B, -90B, and -94B turbofan...

  15. 78 FR 72552 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2013-12-03

    ... Airworthiness Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA... General Electric Company model GEnx-2B67 and GEnx-2B67B turbofan engines. This AD was prompted by the... certain serial number General Electric Company (GE) model GEnx-2B67 and GEnx-2B67B turbofan engines. The...

  16. Electrical drives for direct drive renewable energy systems

    CERN Document Server

    Mueller, Markus

    2013-01-01

    Wind turbine gearboxes present major reliability issues, leading to great interest in the current development of gearless direct-drive wind energy systems. Offering high reliability, high efficiency and low maintenance, developments in these direct-drive systems point the way to the next generation of wind power, and Electrical drives for direct drive renewable energy systems is an authoritative guide to their design, development and operation. Part one outlines electrical drive technology, beginning with an overview of electrical generators for direct drive systems. Principles of electrical design for permanent magnet generators are discussed, followed by electrical, thermal and structural generator design and systems integration. A review of power electronic converter technology and power electronic converter systems for direct drive renewable energy applications is then conducted. Part two then focuses on wind and marine applications, beginning with a commercial overview of wind turbine drive systems and a...

  17. Definite existence of subphases with eight- and ten-layer unit cells as studied by complementary methods, electric-field-induced birefringence and microbeam resonant x-ray scattering.

    Science.gov (United States)

    Feng, Zhengyu; Chandani Perera, A D L; Fukuda, Atsuo; Vij, Jagdish K; Ishikawa, Ken; Iida, Atsuo; Takanishi, Yoichi

    2017-07-01

    A mixture of two selenium-containing compounds, 80 wt. % AS657 and 20 wt. % AS620, are studied with two complementary methods, electric-field-induced birefringence (EFIB) and microbeam resonant x-ray scattering (μRXS). The mixture shows the typical phase sequence of Sm-C_{A}^{*}-1/3-1/2-Sm-C^{*}-Sm-C_{α}^{*}-Sm-A, where 1/3 and 1/2 are two prototypal ferrielectric and antiferroelectric subphases with three- and four-layer unit cells, respectively. Here we designate the subphase as its q_{T} number defined by the ratio of [F]/([F]+[A]), where [F] and [A] are the numbers of synclinic ferroelectric and anticlinic antiferroelectric orderings in the unit cell, respectively. The electric field vs temperature phase diagram with EFIB contours indicates the emergence of three additional subphases, an antiferroelectric one between Sm-C_{A}^{*} and 1/3 and antiferroelectric and apparently ferrielectric ones between 1/3 and 1/2. The simplest probable q_{T}'s for these additional subphases are 1/4, 2/5, and 3/7, respectively, in the order of increasing temperature. The μRXS profiles indicate that antiferroelectric 1/4 and 2/5 approximately have the eight-layer (FAAAFAAA) and ten-layer (FAFAAFAFAA) Ising unit cells, respectively. The remaining subphase may be ferrielectric 3/7 with a seven-layer unit cell, although the evidence is partial. These experimental results are compared with the phenomenological Landau model [P. V. Dolganov and E. I. Kats, Liq. Cryst. Rev. 1, 127 (2014)2168-039610.1080/21680396.2013.869667] and the quasimolecular model [A. V. Emelyanenko and M. A. Osipov, Phys. Rev. E 68, 051703 (2003)1063-651X10.1103/PhysRevE.68.051703].

  18. New directions in electric power financing

    International Nuclear Information System (INIS)

    Jechoutek, K.G.; Lamech, Ranjit

    1995-01-01

    This paper argues that it is necessary to raise the eyes from the current focus on independent power projects, buttressed by guarantees, to the longer horizon of electric power financing in open markets. Transitional strategies will need to move beyond the commonly seen IPP activity that occurs without fundamental sector reform, and demand-side incentives that introduce further market distortions. These efforts will have to focus on macroeconomic stabilization, removal of price distortions, as well as sector and corporate reform. Mobilization of domestic capital will be essential for sustainable sector financing. Although guarantees to encourage power sector investment can be designed to selectively cover risks, their elimination through fundamental sector reform should be the ultimate goal. Over the longer-term traditional corporate finance should become a more common financing strategy than project finance. Innovations in performance risk management and consumer credit will be crucial to the financing of energy efficiency. (author)

  19. 77 FR 4650 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2012-01-31

    ... Airworthiness Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA... General Electric Company (GE) CF6-45 and CF6-50 series turbofan engines with certain low-pressure turbine... Compliance We estimate that this AD will affect 387 CF6-45 and CF6-50 series turbofan engines installed on...

  20. 78 FR 72567 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2013-12-03

    ... Airworthiness Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA... General Electric Company (GE) GE90-110B1 and -115B turbofan engines. This AD was prompted by multiple... turbofan engines with variable bypass valve (VBV) actuator fuel supply tube, part number (P/N) 2165M22P01...

  1. 78 FR 19983 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2013-04-03

    ... Airworthiness Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA... Electric Company (GE) CF34-8C and CF34-8E turbofan engines with certain part numbers (P/N) of operability...-8E6, and CF34-8E6A1 turbofan engines, with an operability bleed valve (OBV) part number (P/N...

  2. 78 FR 76045 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2013-12-16

    ... Airworthiness Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA... (AD) for General Electric Company (GE) GE90-110B1 and GE90-115B turbofan engines with certain high... turbofan engines with high pressure compressor (HPC) rotor stage 2-5 spools, part numbers (P/Ns) 351-103...

  3. 78 FR 38195 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2013-06-26

    ... Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT... all General Electric Company (GE) GE90-110B1 and GE90-115B turbofan engines. This emergency AD was.... owners and operators of these GE90-110B1 and GE90-115B turbofan engines. This action was prompted by...

  4. 78 FR 50320 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2013-08-19

    ... Airworthiness Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA... Electric Company (GE) model GEnx-2B67B turbofan engines with booster anti-ice (BAI) air duct, part number...-2B67 turbofan engine be removed from the Applicability section of this AD. The commenters noted that...

  5. 77 FR 3088 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2012-01-23

    ... Airworthiness Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA... Electric Company (GE) CF34-10E series turbofan engines. This AD was prompted by a report of heavy wear... turbofan engines installed on airplanes of U.S. registry. We also estimate that it will take about 8 work...

  6. The European directive on renewable electricity: conflicts and compromises

    International Nuclear Information System (INIS)

    Rowlands, I.H.

    2005-01-01

    As part of its efforts to increase the use of renewable energy in Europe, a Directive regarding renewable electricity was agreed by the European Union in 2001. The purpose of this article is to examine this Directive, examining how the discussions surrounding its content unfolded. The investigation focuses upon three contentious issues that were debated during the Directive's development: the definition of 'renewable', the national targets for renewable electricity (their levels, as well as whether they should be 'binding' or 'indicative') and the questions associated with harmonisation (whether one Union-wide 'support scheme' for renewable electricity should be in place, and, if so, what it should be). During the 5 years that the Directive was negotiated, many intra-Union conflicts were eventually resolved, at least temporarily, by compromises. Nevertheless, some difficult decisions regarding the promotion of renewable electricity in the European Union still have to be taken

  7. 78 FR 47534 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2013-08-06

    ... Airworthiness Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA... directive (AD) 2013-14-51 for General Electric Company (GE) GE90-110B1 and GE90-115B turbofan engines with... all known U.S. owners and operators of GE90-110B1 and GE90-115B turbofan engines. AD 2013-14-51...

  8. Fuel coolant interaction experiment by direct electrical heating method

    International Nuclear Information System (INIS)

    Takeda, Tsuneo; Hirano, Kenmei

    1979-01-01

    In the PCM (Power Cooling Mismatch) experiments, the FCI (Fuel Coolant Interaction) test is one of necessary tests in order to predict various phenomena that occur during PCM in the core. A direct electrical heating method is used for the FCI tests for fuel pellet temperature of over 1000 0 C. Therefore, preheating is required before initiating the direct electrical heating. The fuel pin used in the FCI tests is typical LWR fuel element, which is surrounded by coolant water. It is undersirable to heat up the coolant water during preheating of the fuel pin. Therefore, a zirconia (ZrO 2 ) pellet which is similar to a UO 2 pellet in physical and chemical properties is used. Electric property (electric conductivity) of ZrO 2 is particularly suitable for direct electrical heating as in the case of UO 2 . In this experiment, ZrO 2 pellet (melting point 2500 0 C) melting was achieved by use of both preheating and direct electrical heating. Temperature changes of coolant and fuel surface, as well as the pressure change of coolant water, were measured. The molten fuel interacted with the coolant and generated shock waves. A portion of this molten fuel fragmented into small particles during this interaction. The peak pressure of the observed shock wave was about 35 bars. The damaged fuel pin was photographed after disassembly. This report shows the measured coolant pressure changes and the coolant temperature changes, as well as photographs of damaged fuel pin and fuel fragments. (author)

  9. Alternatives to electrical cogeneration: The direct application of steam engines

    International Nuclear Information System (INIS)

    Phillips, W.C.

    1993-01-01

    Although small to medium sized industrial facilities are aware of electrical cogeneration, often they are too small for it to be economically justifiable. The direct application of steam turbine power to equipment formerly powered by electric motors, can allow them to use steam capacity to reduce electrical demand and consumption, bypassing cogeneration. Cogeneration converts the heat energy of steam into circular mechanical motion and then converts the circular mechanical motion into electricity. Each conversion entails a loss of energy due to friction and other conversion losses. A substantial amount of the generated electricity is then converted back into circular motion with electric motors, again incurring energy losses. Directly applying the mechanical motion of turbines eliminates both the motion-to-electricity (generator) and the electricity-to-motion (motor) conversion losses. Excess steam capacity during the summer is not unusual for facilities that use steam to provide winter heating. Similarly, most of these facilities experience a large electrical demand peak during the cooling season due to the electricity needed to operate centrifugal chillers. Steam capacity via a turbine to power the chillers can allow the boilers to operate at a higher loading while reducing electrical consumption and demand precisely those periods when demand reduction is most needed. In facilities where the steam generating capacity is sufficient, air compressors provide an appropriate year-round application for turbine power. This paper is the result of an on-going project by the Energy Division, State of North Carolina, Department of Economic and Community Development, in conjunction with the University of North Carolina at Charlotte. The objective of this project is to educate the operating engineers and managers of small to medium sized manufacturing facilities on the technical application and economic justification of steam turbine power

  10. Determinants of the electric field during transcranial direct current stimulation

    DEFF Research Database (Denmark)

    Opitz, Alexander; Paulus, Walter; Will, Susanne

    2015-01-01

    Transcranial direct current stimulation (tDCS) causes a complex spatial distribution of the electric current flow in the head which hampers the accurate localization of the stimulated brain areas. In this study we show how various anatomical features systematically shape the electric field...... over the motor cortex in small steps to examine the resulting changes of the electric field distribution in the underlying cortex. We examined the effect of skull thickness and composition on the passing currents showing that thinner skull regions lead to higher electric field strengths. This effect...... fluid and the skull, the gyral depth and the distance to the anode and cathode. These factors account for up to 50% of the spatial variation of the electric field strength. Further, we demonstrate that individual anatomical factors can lead to stimulation "hotspots" which are partly resistant...

  11. 78 FR 24671 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2013-04-26

    ... Airworthiness Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA... certain General Electric Company (GE) CF6-80C2 series turbofan engines. That AD currently requires.../B1F/B2F/B4F/B6F/B7F/D1F turbofan engines with any of the following installed: (1) Fuel tube, part...

  12. Magnetic field induced dynamical chaos.

    Science.gov (United States)

    Ray, Somrita; Baura, Alendu; Bag, Bidhan Chandra

    2013-12-01

    In this article, we have studied the dynamics of a particle having charge in the presence of a magnetic field. The motion of the particle is confined in the x-y plane under a two dimensional nonlinear potential. We have shown that constant magnetic field induced dynamical chaos is possible even for a force which is derived from a simple potential. For a given strength of the magnetic field, initial position, and velocity of the particle, the dynamics may be regular, but it may become chaotic when the field is time dependent. Chaotic dynamics is very often if the field is time dependent. Origin of chaos has been explored using the Hamiltonian function of the dynamics in terms of action and angle variables. Applicability of the present study has been discussed with a few examples.

  13. Surface modifications by field induced diffusion.

    Directory of Open Access Journals (Sweden)

    Martin Olsen

    Full Text Available By applying a voltage pulse to a scanning tunneling microscope tip the surface under the tip will be modified. We have in this paper taken a closer look at the model of electric field induced surface diffusion of adatoms including the van der Waals force as a contribution in formations of a mound on a surface. The dipole moment of an adatom is the sum of the surface induced dipole moment (which is constant and the dipole moment due to electric field polarisation which depends on the strength and polarity of the electric field. The electric field is analytically modelled by a point charge over an infinite conducting flat surface. From this we calculate the force that cause adatoms to migrate. The calculated force is small for voltage used, typical 1 pN, but due to thermal vibration adatoms are hopping on the surface and even a small net force can be significant in the drift of adatoms. In this way we obtain a novel formula for a polarity dependent threshold voltage for mound formation on the surface for positive tip. Knowing the voltage of the pulse we then can calculate the radius of the formed mound. A threshold electric field for mound formation of about 2 V/nm is calculated. In addition, we found that van der Waals force is of importance for shorter distances and its contribution to the radial force on the adatoms has to be considered for distances smaller than 1.5 nm for commonly used voltages.

  14. Magnetically insulated fission electric cells for direct energy conversion

    International Nuclear Information System (INIS)

    Slutz, S.A.; Seidel, D.B.; Lipinski, R.J.; Rochau, G.E.; Brown, L.C.

    2003-01-01

    The principles of fission electric cells are reviewed. A detailed Monte Carlo model of the efficiency of a fission electric cell is presented and a theory of magnetically insulated fission electric cells (MIFECs) is developed. It is shown that the low operating voltages observed in previous MIFEC experiments were due to nonoptimal magnetic field profiles. Improved magnetic field profiles are presented. It is further shown that the large electric field present in a MIFEC limits the structure of the cathode and can lead to a displacement instability of the cathode toward the anode. This instability places constraints on the number of cells that can be strung together without some external cathode support. The large electric field stress also leads to electrical surface breakdown of the cathode. It is shown that this leads to the formation of a virtual cathode resulting in geometry constraints for spherical cells. Finally it is shown that the requirements of magnetic insulation and high efficiency leads to very low average density of the fissile material. Thus a reactor using fission electric cells for efficient direct energy conversion will be large and require a very large number of cells. This could be mitigated somewhat by the use of exotic fuels

  15. 77 FR 58471 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2012-09-21

    ... Airworthiness Directives; General Electric Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA.../P1, GEnx-1B75/P1, GEnx- 2B67, and GEnx-2B67B turbofan engines. This AD requires initial and... this AD will affect 11 GE GEnx turbofan engines installed on airplanes of U.S. registry. We also...

  16. 77 FR 76977 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2012-12-31

    ... Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Supplemental notice... proposed airworthiness directive (AD) for certain General Electric Company (GE) CF6-80C2 series turbofan... part 39 to include an AD that would apply to certain GE CF6-80C2 series turbofan engines. That NPRM...

  17. Adult subependymal neural precursors, but not differentiated cells, undergo rapid cathodal migration in the presence of direct current electric fields.

    Directory of Open Access Journals (Sweden)

    Robart Babona-Pilipos

    Full Text Available BACKGROUND: The existence of neural stem and progenitor cells (together termed neural precursor cells in the adult mammalian brain has sparked great interest in utilizing these cells for regenerative medicine strategies. Endogenous neural precursors within the adult forebrain subependyma can be activated following injury, resulting in their proliferation and migration toward lesion sites where they differentiate into neural cells. The administration of growth factors and immunomodulatory agents following injury augments this activation and has been shown to result in behavioural functional recovery following stroke. METHODS AND FINDINGS: With the goal of enhancing neural precursor migration to facilitate the repair process we report that externally applied direct current electric fields induce rapid and directed cathodal migration of pure populations of undifferentiated adult subependyma-derived neural precursors. Using time-lapse imaging microscopy in vitro we performed an extensive single-cell kinematic analysis demonstrating that this galvanotactic phenomenon is a feature of undifferentiated precursors, and not differentiated phenotypes. Moreover, we have shown that the migratory response of the neural precursors is a direct effect of the electric field and not due to chemotactic gradients. We also identified that epidermal growth factor receptor (EGFR signaling plays a role in the galvanotactic response as blocking EGFR significantly attenuates the migratory behaviour. CONCLUSIONS: These findings suggest direct current electric fields may be implemented in endogenous repair paradigms to promote migration and tissue repair following neurotrauma.

  18. Direct electroplating of plastic for advanced electrical applications

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    2017-01-01

    Electrodeposition or electroplating is predominantly applied to metallic components. Electroplating of plastics is possible in some cases where an initial electroless plating layer of nickel or copper is made to provide a conductive surface on the plastic part. This paper proposes a method...... for direct electroplating of plastic eliminating the need for slow and expensive processes like electroless metal deposition, PVD coating, painting with conductive inks etc. The results obtained from the test demonstrate the potential of direct electroplating of plastic to enhance the electrical conductivity...... and the use of electroplated plastics for advanced applications like Moulded Interconnect Devices (MIDs)....

  19. Field-induced stacking transition of biofunctionalized trilayer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Masato Nakano, C. [Flintridge Preparatory School, La Canada, California 91011 (United States); Sajib, Md Symon Jahan; Samieegohar, Mohammadreza; Wei, Tao [Dan F. Smith Department of Chemical Engineering, Lamar University, Beaumont, Texas 77710 (United States)

    2016-02-01

    Trilayer graphene (TLG) is attracting a lot of attention as their stacking structures (i.e., rhombohedral vs. Bernal) drastically affect electronic and optical properties. Based on full-atom molecular dynamics simulations, we here predict electric field-induced rhombohedral-to-Bernal transition of TLG tethered with proteins. Furthermore, our simulations show that protein's electrophoretic mobility and diffusivity are enhanced on TLG surface. This phenomenon of controllable TLG stacking transition will contribute to various applications including biosensing.

  20. Structural evolution, electrical properties and electric-field-induced changes of (0.8-x)PbTiO{sub 3}-xBiFeO{sub 3}-0.2BaZrO{sub 3} system near the morphotropic phase boundary

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Yongxing; Jin, Changqing; Ye, Pin; Xu, Gang [Xi' an Technological University, School of Materials and Chemical Engineering, Xi' an (China); Li, Peng [Northwest Institute For Nonferrous Metal Research, Xi' an (China); Zeng, Yiming [Kunming Institute of Precious Metals, State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Kunming (China)

    2017-04-15

    The crystal structures, piezoelectric property, dielectric transition and electric-field-induced changes in the structures and dielectric constant of (0.8-x)PbTiO{sub 3}-xBiFeO{sub 3}-0.2BaZrO{sub 3} (0.3 ≤ x ≤ 0.4) ceramics near the morphotropic phase boundary have been studied. All the ceramics could be indexed on the base of a tetragonal symmetry. The increasing concentration of BiFeO{sub 3} induces a reduction in the c/a ratio, ranged from 1.022 for x = 0.3 to 1.007 for x = 0.4. Accordingly, the piezoelectric coefficient (d{sub 33}) reaches a maximum value at x = 0.34 (d{sub 33}, 138 pC/N). A relaxor-type dielectric anomaly could be found for all the ceramics. The temperature of the maximum dielectric constant (T{sub m}) at 1 MHz and the degree of the diffuseness for the dielectric anomaly (δ) increase with BiFeO{sub 3} concentration, from 544 and 96 K for x = 0.3 to 574 and 154 K for x = 0.4. After poling, the ceramic for x = 0.34 shows an increase in the c/a ratio and an obvious decrease in the dielectric constant. (orig.)

  1. Demand response offered by households with direct electric heating

    International Nuclear Information System (INIS)

    Kofod, C.; Togeby, M.

    2004-01-01

    The peak power balance in the Nordic power system is gradually turning to be very tight, especially in the electric area of southern Sweden and eastern Denmark. Power stations are closed and hardly any investments in new production are carried out. Demand response is considered essential when the formation of spot prices shall send the signal of needed investments in new capacity. Demand response which are based on individual preferences, and carried out automatically, can be one way to increase the volume of price elastic demand. Demand response need hourly metering for calculation and documentation of the decrease in demand, and controllability in order to meet the timing requirements. Within the EU SAVE project EFFLOCOM (2002 - 2004), a Danish demand response pilot project was established in 2003 including 25 single family homes with direct electrical heating. The system has been tested during the winter 2003/2004. The tested technologies include hourly metering, communication by GRPS as well as the Internet. GPRS is used for daily remote meter reading and automatic control of the electric heating including individual control of up to five zones. The system is designed for automatic activation when the Nord Pool hourly Elspot prices exceed preset levels. The system can also be used as regulating power. The EFFLOCOM Web Bite includes an interactive demonstrator of the system. The developed customer Web Bite is including the services: 1) Access to setting the limits for the maximum duration of interruption for up to five different control zones for two periods of the day and for three price levels. 2) Access to stop an actual interruption. 3) A report on the hourly, daily, weekly and monthly use of electricity and the saved bonus by demand response control. The report is updated daily. The goals of up to 5 kW controlled per house were fulfilled. Besides the demand response bonus the customers have also saved electricity. A customer survey did show that the

  2. Direct Electrical Stimulation in the Human Brain Disrupts Melody Processing.

    Science.gov (United States)

    Garcea, Frank E; Chernoff, Benjamin L; Diamond, Bram; Lewis, Wesley; Sims, Maxwell H; Tomlinson, Samuel B; Teghipco, Alexander; Belkhir, Raouf; Gannon, Sarah B; Erickson, Steve; Smith, Susan O; Stone, Jonathan; Liu, Lynn; Tollefson, Trenton; Langfitt, John; Marvin, Elizabeth; Pilcher, Webster H; Mahon, Bradford Z

    2017-09-11

    Prior research using functional magnetic resonance imaging (fMRI) [1-4] and behavioral studies of patients with acquired or congenital amusia [5-8] suggest that the right posterior superior temporal gyrus (STG) in the human brain is specialized for aspects of music processing (for review, see [9-12]). Intracranial electrical brain stimulation in awake neurosurgery patients is a powerful means to determine the computations supported by specific brain regions and networks [13-21] because it provides reversible causal evidence with high spatial resolution (for review, see [22, 23]). Prior intracranial stimulation or cortical cooling studies have investigated musical abilities related to reading music scores [13, 14] and singing familiar songs [24, 25]. However, individuals with amusia (congenitally, or from a brain injury) have difficulty humming melodies but can be spared for singing familiar songs with familiar lyrics [26]. Here we report a detailed study of a musician with a low-grade tumor in the right temporal lobe. Functional MRI was used pre-operatively to localize music processing to the right STG, and the patient subsequently underwent awake intraoperative mapping using direct electrical stimulation during a melody repetition task. Stimulation of the right STG induced "music arrest" and errors in pitch but did not affect language processing. These findings provide causal evidence for the functional segregation of music and language processing in the human brain and confirm a specific role of the right STG in melody processing. VIDEO ABSTRACT. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Transient fission gas release during direct electrical heating experiments

    International Nuclear Information System (INIS)

    Fenske, G.R.; Emerson, J.E.; Savoie, F.E.

    1983-12-01

    The gas release behavior of irradiated EBR-II fuel was observed to be dependent on several factors: the presence of cladding, the retained gas content, and the energy absorbed. Fuel that retained in excess of 16 to 17 μmoles/g of fission gas underwent spallation as the cladding melted and released 22 to 45% of its retained gas, while fuel with retained gas levels below approx. 15 to 16 μmoles/g released less than approx. 9% of its gas as the cladding melted. During subsequent direct electrical heating ramps, fuel that did not spall released an additional quantity of gas (up to 4 μmoles/g), depending on the energy absorbed

  4. Possibility of direct electricity production from waste canola oil

    Science.gov (United States)

    Włodarczyk, Paweł P.; Włodarczyk, Barbara; Kalinichenko, Antonina

    2017-10-01

    Powering high-efficiency devices, such as fuel cells, with waste products will allow for a broader development of renewable energy sources and utilisation of by- products. This publication presents the possibility of electrooxidation of the emulsion of waste rapeseed oil, prepared on the basis of the detergent Syntanol DS-10. The process of electrooxidation was carried out on platinum electrode in alkaline (KOH) and acidic (H2SO4) electrolyte, in the temperature range of 293-333 K. In each analysed case the process of electrooxidation took place. The maximum current density obtained was 7 mA cm-2. Thus, it has been shown that it is possible to generate electricity directly from the emulsion of the waste rapeseed oil.

  5. Possibility of direct electricity production from waste canola oil

    Directory of Open Access Journals (Sweden)

    Włodarczyk Paweł P.

    2017-01-01

    Full Text Available Powering high-efficiency devices, such as fuel cells, with waste products will allow for a broader development of renewable energy sources and utilisation of by- products. This publication presents the possibility of electrooxidation of the emulsion of waste rapeseed oil, prepared on the basis of the detergent Syntanol DS-10. The process of electrooxidation was carried out on platinum electrode in alkaline (KOH and acidic (H2SO4 electrolyte, in the temperature range of 293-333 K. In each analysed case the process of electrooxidation took place. The maximum current density obtained was 7 mA cm-2. Thus, it has been shown that it is possible to generate electricity directly from the emulsion of the waste rapeseed oil.

  6. The green electricity market model. Proposal for an optional, cost-neutral direct marketing model for supplying electricity customers

    International Nuclear Information System (INIS)

    Heinemann, Ronald

    2014-01-01

    One of the main goals of the Renewable Energy Law (EEG) is the market integration of renewable energy resources. For this purpose it has introduced compulsory direct marketing on the basis of a moving market premium. At the same time the green electricity privilege, a regulation which made it possible for customers to be supplied with electricity from EEG plants, has been abolished without substitution with effect from 1 August 2014. This means that, aside from other direct marketing channels, which will not be economically viable save for in a few exceptional cases, it will no longer be possible in future to sell electricity from EEG plants to electricity customers under the designation ''electricity from renewable energy''. The reason for this is that electricity sold under the market premium model can no longer justifiably be said to originate from renewable energy. As a consequence, almost all green electricity products sold in Germany carry a foreign green electricity certificate.

  7. Magnetic-field induced semimetal in topological crystalline insulator thin films

    International Nuclear Information System (INIS)

    Ezawa, Motohiko

    2015-01-01

    We investigate electromagnetic properties of a topological crystalline insulator (TCI) thin film under external electromagnetic fields. The TCI thin film is a topological insulator indexed by the mirror-Chern number. It is demonstrated that the gap closes together with the emergence of a pair of gapless cones carrying opposite chirarities by applying in-plane magnetic field. A pair of gapless points have opposite vortex numbers. This is a reminiscence of a pair of Weyl cones in 3D Weyl semimetal. We thus present an a magnetic-field induced semimetal–semiconductor transition in 2D material. This is a giant-magnetoresistance, where resistivity is controlled by magnetic field. Perpendicular electric field is found to shift the gapless points and also renormalize the Fermi velocity in the direction of the in-plane magnetic field. - Highlights: • The band structure of topological crystalline insulator thin films can be controlled by applying in-plane magnetic field. • At the gap closing magnetic field, a pair of gapless cones carrying opposite chirarities emerge. • A pair of gapless points have opposite vortex numbers. • This is a reminiscence of a pair of Weyl cones in 3D Weyl semimetal. • A magnetic-field induced semimetal–semiconductor transition occurs in 2D material

  8. Magnetic-field induced semimetal in topological crystalline insulator thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ezawa, Motohiko, E-mail: ezawa@ap.t.u-tokyo.ac.jp

    2015-06-19

    We investigate electromagnetic properties of a topological crystalline insulator (TCI) thin film under external electromagnetic fields. The TCI thin film is a topological insulator indexed by the mirror-Chern number. It is demonstrated that the gap closes together with the emergence of a pair of gapless cones carrying opposite chirarities by applying in-plane magnetic field. A pair of gapless points have opposite vortex numbers. This is a reminiscence of a pair of Weyl cones in 3D Weyl semimetal. We thus present an a magnetic-field induced semimetal–semiconductor transition in 2D material. This is a giant-magnetoresistance, where resistivity is controlled by magnetic field. Perpendicular electric field is found to shift the gapless points and also renormalize the Fermi velocity in the direction of the in-plane magnetic field. - Highlights: • The band structure of topological crystalline insulator thin films can be controlled by applying in-plane magnetic field. • At the gap closing magnetic field, a pair of gapless cones carrying opposite chirarities emerge. • A pair of gapless points have opposite vortex numbers. • This is a reminiscence of a pair of Weyl cones in 3D Weyl semimetal. • A magnetic-field induced semimetal–semiconductor transition occurs in 2D material.

  9. Direct numerical simulation of noninvasive channel healing in electrical field

    KAUST Repository

    Wang, Yi

    2017-11-25

    Noninvasive channel healing is a new idea to repair the broken pipe wall, using external electric fields to drive iron particles to the destination. The repair can be done in the normal operation of the pipe flow without any shutdown of the pipeline so that this method can be a potentially efficient and safe technology of pipe healing. However, the real application needs full knowledge of healing details. Numerical simulation is an effective method. Thus, in this research, we first established a numerical model for noninvasive channel healing technology to represent fluid–particle interaction. The iron particles can be attached to a cracking area by external electrostatic forces or can also be detached by mechanical forces from the fluid. When enough particles are permanently attached on the cracking area, the pipe wall can be healed. The numerical criterion of the permanent attachment is discussed. A fully three-dimensional finite difference framework of direct numerical simulation is established and applied to different cases to simulate the full process of channel healing. The impact of Reynolds number and particle concentration on the healing process is discussed. This numerical investigation provides valuable reference and tools for further simulation of real pipe healing in engineering.

  10. Investigations on magnetic field induced optical transparency in magnetic nanofluids

    Science.gov (United States)

    Mohapatra, Dillip Kumar; Philip, John

    2018-02-01

    We study the magnetic field induced optical transparency and its origin in magnetic nanoemulsion of droplets of average size ∼200 nm containing superparamagnetic iron oxide nanoparticles. Beyond a certain volume fraction (Φ > 0.0021) of magnetic nanoemulsion and a critical magnetic field (Hc1), the transmitted light intensity increases drastically and reaches a maximum at another critical magnetic field (Hc2), beyond which the transmitted light intensity decreases and reaches a plateau. Interestingly, the transmitted light intensity at Hc2 is found to increase linearly with Φ and the critical magnetic fields Hc1 and Hc2 follow power law decay with Φ (i.e. Hc ∼ Φ-x), with exponents 0.48 and 0.27, respectively. The light intensity recovers to its initial value when the magnetic field is switched off, indicating the perfect reversibility of the field induced transparency process. The observed straight line scattered patterns above Hc2, on a screen placed perpendicular to the incident beam, confirms the formation of rod like anisotropic nanostructures perpendicular to the direction of light propagation. The magneto-optical measurements in the emulsion confirm that the observed field induced transparency in magnetic emulsions for Φ > 0.0021 is due to the optical birefringence caused by the rod like nanostructures. The reduced birefringence is found to be proportional to the square of the applied magnetic field. This finding offers several possibilities in using magnetic nanofluids in tunable optical devices.

  11. Electric power distribution: in the direction of a competitive market?

    International Nuclear Information System (INIS)

    Souza, J.R.A. de.

    1993-01-01

    This paper discusses the process of electric power sector deregulation, occurred in several countries, frequently followed of privatization, which the aim is activate the competition and, consequently, the efficiency between the companies of the electric power sector. The competition in the supply market of electric power, by the Great Britain, France, Spain and United States are shown as an example of this energy policy. (C.G.C.)

  12. Direction and Policies Needed to Support Hybrid Electric Car Research

    OpenAIRE

    Subekti, Ridwan Arief; Hartanto, Agus; Susanti, Vita

    2012-01-01

    The rising number of vehicles over the years has driven the increase of air pollution and fuel consumption. One of the solutions to overcome this problem is using hybrid electric car because it is environmentally friendly and efficient in fuel consumption. LIPI has conducted electric car research since 1997, but there were so many problems in its development that electric car can not be developed into a national industry scale. Therefore, it is important to conduct a study that maps the probl...

  13. Direction and Policies Needed to Support Hybrid Electric Car Research

    Directory of Open Access Journals (Sweden)

    Ridwan Arief Subekti

    2012-07-01

    Full Text Available The rising number of vehicles over the years has driven the increase of air pollution and fuel consumption. One of the solutions to overcome this problem is using hybrid electric car because it is environmentally friendly and efficient in fuel consumption. LIPI has conducted electric car research since 1997, but there were so many problems in its development that electric car can not be developed into a national industry scale. Therefore, it is important to conduct a study that maps the problems and finds the solutions to prevent the same failure of electric car commercialization process from happening to hybrid electric car . This study was done by collecting and analyzing the primary and secondary data through interviews, discussing electric hybrid car with stakeholders, and examining earlier study results and regulations. Based on this study, several policies to support sustainability research of hybrid electric car were proposed. Some recommendations were the making of national roadmap and regulation for the usage of hybrid electric car on the road. For policy makers at LIPI, a research focus, research coordination, and pre-commercialization program were recommended.

  14. The direct conversion of heat into electricity in reactors

    International Nuclear Information System (INIS)

    Devin, B.; Bliaux, J.; Lesueur, R.

    1964-01-01

    The direct conversion of heat into electricity by thermionic emission in an atomic reactor has been studied with the triple aim of its utilisation: as an energy source for a space device, at the head of a conventional conversion system in power installations, or finally in association with the thermoelectric conversion in very low power installations. The laboratory experiments were mainly orientated towards the electron extraction of metals and compounds and their behaviour at high temperatures. Converters furnishing up to 50 amps at 0. 4 volts with an efficiency close to 10 p. 100 have been constructed in the laboratory; the emitters were heated by electron bombardment and were composed of tungsten covered with an uranium carbide deposit or molybdenum covered with cesium. The main aspects of the coupling between the converter and the reactor have been covered from the point of view of electronics: the influence of the mismatching of the load on the temperature of the emitter and the influence of thermal flux density on the temperature of the emitter and the stability of the converter. Converters using uranium carbide as the electron emitter have been tested in reactors. Tests have been made under dynamic conditions in order to determine the dynamic characteristics. The load matching curves have been constructed and the overall performances of several cells coupled in such a way as to form a reactor rod have been deduced. This information is fundamental to the design of a control system for a thermionic conversion reactor. The problems associated with the reliability of thermionic converters connected in series in the same reactor rod have been examined theoretically. Finally, the absorption isotherms have been drawn at the ambient temperatures for krypton and xenon on activated carbon with the aim of investigating the escape of fission products in a converter. (author) [fr

  15. 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.

  16. Direct Conversion of Radioisotope Energy to Electricity: Year 3 Report

    International Nuclear Information System (INIS)

    Marks Prelas; Alexey Spitsyn; Alejandro Suarez; Eric Stienfelds; Dickerson Moreno; Bia-Ling Hsu; Tushar Ghosh; Robert Tompson; Sudarshan Loyalka; Dabir Viswanath

    2003-01-01

    A new chemical reactor has been tested for Field Enhanced Diffusion by Optical Activation doping and purification of SiC, GaN and AlN films. Different conditions have been used on SiC, GaN and AlN samples including temperature variation, electrical field variation, variations in electrical current and optical activation. A 5mW (630-680) nm laser was used for optical activation. It was observed that optical activation has a major effect on ion drift rates. It was also observed that the magnitude of the electrical current also enhanced ion drift rates by a postulated current drag mechanism. I-V characteristic curves were measured to verify changes in the electrical properties of the samples SIMS was used to analyze the concentrations of impurities in the film samples before and after treatment. It has been demonstrated that the field-enhanced diffusion by optical activation method can dope and purify the films. As a result, the electrical properties of the wafers have been significantly improved during treatment especially in cases where a laser is used

  17. ELECTRIC VEHICULE – A NEW DIRECTION FOR SOCIO-ECONOMIC

    Directory of Open Access Journals (Sweden)

    ŞTEFAN CÎRSTEA

    2015-10-01

    Full Text Available Mobility is a major factor of economic growth and social development. The vehicle is the centrepiece of what mobility means and it is expected that, in future, the use of vehicle continues to grow, particularly in developing countries. This article wants to highlight the need to implement electric vehicles in contemporary society and, also, highlight some of the advantages and socio-economic benefits that such action entails. The aim of this paper is estimating the possible influence of such shift in different aspects of economics as a whole. The results underline the main advantages and disadvantages of adopting the electric vehicule.

  18. Direct numerical simulation of noninvasive channel healing in electrical field

    KAUST Repository

    Wang, Yi; Sun, Shuyu

    2017-01-01

    Noninvasive channel healing is a new idea to repair the broken pipe wall, using external electric fields to drive iron particles to the destination. The repair can be done in the normal operation of the pipe flow without any shutdown of the pipeline

  19. The future direction of electricity reform in APEC economies

    International Nuclear Information System (INIS)

    Pritchard, Robert

    2005-01-01

    A 2003 study of Electricity Supply Industry (ESI) reform experience in the 21 Asia-Pacific Economic Cooperation (APEC) economies emphasised that the overriding principle of ESI reform must be to maintain the security and stability of the entire power system. This is what differentiates ESI reform from reform of other industries. For all economies, particularly developing economies, attracting private investment in the ESI is a vital ongoing need. However, since the mid-1990s, private investors have become more risk-averse. Today, it is less safe for governments to assume that their 'reformed' electricity sectors will attract the requisite level of private investment. The APEC study found that competitive electricity markets are unsuited to developing economies in the early stages of reform. However, enterprise level reforms can produce major gains by commercialising and corporatising electricity utilities and by providing them with economic incentives to operate to high technical and commercial standards. The APEC study also emphasised that governments must remain responsible for the outcomes of ESI reform irrespective of any changes in industry structure and ownership. This is a fundamental responsibility which cannot be left to a regulator. (Author)

  20. 77 FR 48110 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2012-08-13

    ... Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... certain General Electric Company (GE) CF6-80C2 series turbofan engines. The existing AD requires... 2000-04-14, Amendment 39-11597 (65 FR 10698, February 29, 2000), for all GE CF6-80C2 series turbofan...

  1. 78 FR 44899 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2013-07-25

    ... Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Electric Company (GE) GE90-110B1 and -115B turbofan engines. This proposed AD was prompted by multiple...) 2165M22P01, installed on GE90-110B1 and -115B turbofan engines. One of the leaks led to an under cowl engine...

  2. 76 FR 64844 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2011-10-19

    ... Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... General Electric Company (GE) CF6-45 and CF6-50 series turbofan engines with certain low-pressure turbine... series turbofan engines with certain LPT rotor stage 3 disks installed. That AD requires initial and...

  3. 78 FR 19628 - Airworthiness Directives; General Electric Company Turbofan Engines

    Science.gov (United States)

    2013-04-02

    ... Company Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Electric Company (GE) GE90-76B, -85B, -90B, -94B, - 110B1, and -115B turbofan engines. This proposed AD was... of stage 1 HPT stator shroud distress resulting in engine removals on airplanes with GE90 turbofan...

  4. Direct numerical simulation of MHD flow with electrically conducting wall

    International Nuclear Information System (INIS)

    Satake, S.; Kunugi, T.; Naito, N.; Sagara, A.

    2006-01-01

    The 2D vortex problem and 3D turbulent channel flow are treated numerically to assess the effect of electrically conducting walls on turbulent MHD flow. As a first approximation, the twin vortex pair is considered as a model of a turbulent eddy near the wall. As the eddy approaches and collides with the wall, a high value electrical potential is induced inside the wall. The Lorentz force, associated with the potential distribution, reduces the velocity gradient in the near-wall region. When considering a fully developed turbulent channel flow, a high electrical conductivity wall was chosen to emphasize the effect of electromagnetic coupling between the wall and the flow. The analysis was performed using DNS. The results are compared with a non-MHD flow and MHD flow in the insulated channel. The mean velocity within the logarithmic region in the case of the electrically conducting wall is slightly higher than that in the non-conducting wall case. Thus, the drag is smaller compared to that in the non-conducting wall case due to a reduction of the Reynolds stress in the near wall region through the Lorentz force. This mechanism is explained via reduction of the production term in the Reynolds shear stress budget

  5. Field-induced negative differential spin lifetime in silicon.

    Science.gov (United States)

    Li, Jing; Qing, Lan; Dery, Hanan; Appelbaum, Ian

    2012-04-13

    We show that the electric-field-induced thermal asymmetry between the electron and lattice systems in pure silicon substantially impacts the identity of the dominant spin relaxation mechanism. Comparison of empirical results from long-distance spin transport devices with detailed Monte Carlo simulations confirms a strong spin depolarization beyond what is expected from the standard Elliott-Yafet theory even at low temperatures. The enhanced spin-flip mechanism is attributed to phonon emission processes during which electrons are scattered between conduction band valleys that reside on different crystal axes. This leads to anomalous behavior, where (beyond a critical field) reduction of the transit time between spin-injector and spin-detector is accompanied by a counterintuitive reduction in spin polarization and an apparent negative spin lifetime.

  6. Field-induced resistance switching at metal/perovskite manganese oxide interface

    International Nuclear Information System (INIS)

    Ohkubo, I.; Tsubouchi, K.; Harada, T.; Kumigashira, H.; Itaka, K.; Matsumoto, Y.; Ohnishi, T.; Lippmaa, M.; Koinuma, H.; Oshima, M.

    2008-01-01

    Planar type metal/insulator/metal structures composed of an epitaxial perovskite manganese oxide layer and various metal electrodes were prepared for electric-field-induced resistance switching. Only the electrode pairs including Al show good resistance switching and the switching ratio reaches its maximum of 1000. This resistance switching occurs around the interface between Al electrodes and epitaxial perovskite manganese oxide thin films

  7. The efficiency of direct torque control for electric vehicle behavior improvement

    Directory of Open Access Journals (Sweden)

    Gasbaoui Brahim

    2011-01-01

    Full Text Available Nowadays the electric vehicle motorization control takes a great interest of industrials for commercialized electric vehicles. This paper is one example of the proposed control methods that ensure both safety and stability the electric vehicle by the means of Direct Torque Control (DTC. For motion of the vehicle the electric drive consists of four wheels: two front ones for steering and two rear ones for propulsion equipped with two induction motors, due to their lightweight simplicity and high performance. Acceleration and steering are ensured by the electronic differential, permitting safe and reliable steering at any curve. The direct torque control ensures efficiently controlled vehicle. Electric vehicle direct torque control is simulated in MATLAB SIMULINK environment. Electric vehicle (EV demonstrated satisfactory results in all type of roads constraints: straight, ramp, downhill and bends.

  8. ELECTRIC VEHICULE – A NEW DIRECTION FOR SOCIO-ECONOMIC

    OpenAIRE

    ŞTEFAN CÎRSTEA

    2015-01-01

    Mobility is a major factor of economic growth and social development. The vehicle is the centrepiece of what mobility means and it is expected that, in future, the use of vehicle continues to grow, particularly in developing countries. This article wants to highlight the need to implement electric vehicles in contemporary society and, also, highlight some of the advantages and socio-economic benefits that such action entails. The aim of this paper is estimating the possible influe...

  9. Future directions and cycles for electricity production from geothermal resources

    International Nuclear Information System (INIS)

    Michaelides, Efstathios E.

    2016-01-01

    Graphical abstract: 25% more power may be produced using binary-flashing geothermal cycles. - Highlights: • Power from geothermal power plants is continuously available and “dispatchable.” • The next generation of geothermal will include more binary plants. • Lower temperature geothermal resources will be utilized in the future. • Dry rock resources may produce a high fraction of electricity in several countries. - Abstract: Geothermal power production is economically competitive and capable to produce a high percentage of the electric power demand in several countries. The currently operating geothermal power plants utilize water from an aquifer at relatively higher temperatures and produce power using dry steam, flashing or binary cycles. A glance at the map of the global geothermal resources proves that there is a multitude of sites, where the aquifer temperature is lower. There are also many geothermal resources where a high geothermal gradient exists in the absence of an aquifer. It becomes apparent that the next generation of geothermal power plants will utilize more of the lower-temperature aquifer resources or the dry resources. For such power plants to be economically competitive, modified or new cycles with higher efficiencies must be used. This paper presents two methods to increase the efficiency of the currently used geothermal cycles. The first uses a binary-flashing system to reduce the overall entropy production, thus, producing more electric power from the resource. The second describes a heat extraction system to be used with dry hot-rock resources.

  10. The Problems of implementation of the European Union directives for electrical and electronic equipment hazardousness

    OpenAIRE

    Vaišvila, Anicetas; Vaičikonis, Eduardas

    2006-01-01

    The problems of implementation of two new EU Directives is discussed in this article. It is so called WEEE (Waste Electrical and Electronic Equipment) and RoHS (Restriction of use of certain Hazardous Substances in electrical and electronic equipment), as well as influence of these directives to quality and environmental management systems. The RoHS directive requires a number of potentially hazardous substances (lead, mercury, cadmium, hexavalent chromium, polybrominated byphenyls (PBB) and ...

  11. AC electric field induced vortex in laminar coflow diffusion flames

    KAUST Repository

    Xiong, Yuan; Cha, Min; Chung, Suk-Ho

    2014-01-01

    Experiments were performed by applying sub-critical high-voltage alternating current (AC) to the nozzle of laminar propane coflow diffusion flames. Light scattering, laser-induced incandescence and laser-induced fluorescence techniques were used to identify the soot zone, and the structures of OH and polycyclic aromatic hydrocarbons (PAHs). Particle image velocimetry was adopted to quantify the velocity field. Under certain AC conditions of applied voltage and frequency, the distribution of PAHs and the flow field near the nozzle exit were drastically altered, leading to the formation of toroidal vortices. Increased residence time and heat recirculation inside the vortex resulted in appreciable formation of PAHs and soot near the nozzle exit. Decreased residence time along the jet axis through flow acceleration by the vortex led to a reduction in the soot volume fraction in the downstream sooting zone. Electromagnetic force generated by AC was proposed as a viable mechanism for the formation of the toroidal vortex. The onset conditions for the vortex formation supported the role of an electromagnetic force acting on charged particles in the flame zone. (C) 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  12. AC electric field induced vortex in laminar coflow diffusion flames

    KAUST Repository

    Xiong, Yuan

    2014-09-22

    Experiments were performed by applying sub-critical high-voltage alternating current (AC) to the nozzle of laminar propane coflow diffusion flames. Light scattering, laser-induced incandescence and laser-induced fluorescence techniques were used to identify the soot zone, and the structures of OH and polycyclic aromatic hydrocarbons (PAHs). Particle image velocimetry was adopted to quantify the velocity field. Under certain AC conditions of applied voltage and frequency, the distribution of PAHs and the flow field near the nozzle exit were drastically altered, leading to the formation of toroidal vortices. Increased residence time and heat recirculation inside the vortex resulted in appreciable formation of PAHs and soot near the nozzle exit. Decreased residence time along the jet axis through flow acceleration by the vortex led to a reduction in the soot volume fraction in the downstream sooting zone. Electromagnetic force generated by AC was proposed as a viable mechanism for the formation of the toroidal vortex. The onset conditions for the vortex formation supported the role of an electromagnetic force acting on charged particles in the flame zone. (C) 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  13. High Torque, Direct Drive Electric Motor, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Bear Engineering proposes to advance the development of an innovative high torque, low speed, direct drive motor in order to meet NASA's requirements for such...

  14. High Torque, Direct Drive Electric Motor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Bear Engineering proposes to develop an innovative high torque, low speed, direct drive motor in order to meet NASA's requirements for such devices. Fundamentally,...

  15. The direct conversion of solar energy to electricity

    International Nuclear Information System (INIS)

    1992-01-01

    Half the world's population lives without access to electricity in the rural areas and villages of developing countries. In 1987, world population reached 5 billion and, according to World Bank projections, will increase to over 6 billion in the year 2000 and to over 8 billion in 2025. Such population growth is not uniformly distributed: developed countries have small or negative growth and account for a declining proportion of the world's population. Inasmuch as 95 per cent of the extra inhabitants added each year are in developing countries, rapid population growth in those countries raises serious questions about energy availability for basic human needs and, of course, more broadly about the environment's capacity to support that growth. The present report makes reference to one of the most comprehensively documented conservative scenarios for world energy demand in the year 2020, namely, Energy for a Sustainable World, which assumed that long-term world sustainability must entail constraints on (a) use of natural resources and (b) combustion of fossil fuels resulting in the greenhouse effect. Solar energy is abundant and could become a major source of electricity. Photovoltaics has three particular advantages. It accomplishes sunlight-to-electricity conversion entirely with solid-state electronic components, and with no moving parts required, thereby promising high equipment availability and very low operating and maintenance costs. PV also appears to have very limited environmental impact, with no emissions of the gaseous pollutants associated with fossil-fuel burning and few of the possible local problems associated with some other renewable energy technologies. Finally, the products of photovoltaic technology are modular in construction and can be built up on site in a flexible way, thus minimizing front-end financial risk and investment costs. Figs and tabs

  16. Direct external investment in the Brazilian electric power sector

    International Nuclear Information System (INIS)

    Pinto Junior, Helder Queiroz; Silveira, Joyce Perin; Losekann, Luciano Dias

    1999-01-01

    The central issue of debate was the need to align the energy sector's options and organization with changing global patterns of economic and social development, characterized by the increasing role played by the private sector, greater integration in the world economy, and new economic and social priorities such as efficiency, decentralization, deregulation, and a closer attention to environmental issues. The aim of the work was to identify the foreign investors participants of Brazilian privatization in the electric power sector and to analyze their strategies

  17. The development of direct core monitoring in Nuclear Electric plc

    International Nuclear Information System (INIS)

    Curtis, R.F.; Jones, S. Reed, J.; Wickham, A.J.

    1996-01-01

    Monitoring of graphite behaviour in Nuclear Electric Magnox and AGR reactors is necessary to support operating safety cases and to ensure that reactor operation is optimized to sustain the necessary core integrity for the economic life of the reactors. The monitoring programme combines studies for pre-characterized ''installed'' samples with studies on samples trepanned from within the cores and also with studies of core and channel geometry using specially designed equipment. Nuclear Electric has two trepanning machines originally designed for Magnox-reactor work which have been used for a substantial programme over many years. They have recently been upgraded to improve sampling speed, safety and versatility - the last being demonstrated by their adaptation for a recently-won contract associated with decommissioning the Windscale piles. Radiological hazards perceived when the AGR trepanning system was designed resulted in very cumbersome equipment. This has worked well but has been inconvenient in operation. The development of a smaller and improved system for deploying the equipment is now reported. Channel dimension monitoring equipment is discussed in detail with examples of data recovered from both Magnox and AGR cores. A resolution of ± 2 of arc (tilt) and ± 0.01 mm change in diameter in attainable. It is also theoretically possible to establish brick stresses by measuring geometry changes which result from trepanning. Current development work on a revolving scanning laser rangefinder which will enable the measurement of diameters to a resolution of 0.001 mm will also be discussed. This paper also discusses non-destructive techniques for crack detection employing ultrasound or resistance networks, the use of special manipulators to deliver inspection and repair equipment and recent developments to install displacement monitors in peripheral regions of the cores, to aid the understanding of the interaction of the restraint system with the core - the region

  18. The morphological and molecular changes of brain cells exposed to direct current electric field stimulation.

    Science.gov (United States)

    Pelletier, Simon J; Lagacé, Marie; St-Amour, Isabelle; Arsenault, Dany; Cisbani, Giulia; Chabrat, Audrey; Fecteau, Shirley; Lévesque, Martin; Cicchetti, Francesca

    2014-12-07

    The application of low-intensity direct current electric fields has been experimentally used in the clinic to treat a number of brain disorders, predominantly using transcranial direct current stimulation approaches. However, the cellular and molecular changes induced by such treatment remain largely unknown. Here, we tested various intensities of direct current electric fields (0, 25, 50, and 100V/m) in a well-controlled in vitro environment in order to investigate the responses of neurons, microglia, and astrocytes to this type of stimulation. This included morphological assessments of the cells, viability, as well as shape and fiber outgrowth relative to the orientation of the direct current electric field. We also undertook enzyme-linked immunosorbent assays and western immunoblotting to identify which molecular pathways were affected by direct current electric fields. In response to direct current electric field, neurons developed an elongated cell body shape with neurite outgrowth that was associated with a significant increase in growth associated protein-43. Fetal midbrain dopaminergic explants grown in a collagen gel matrix also showed a reorientation of their neurites towards the cathode. BV2 microglial cells adopted distinct morphological changes with an increase in cyclooxygenase-2 expression, but these were dependent on whether they had already been activated with lipopolysaccharide. Finally, astrocytes displayed elongated cell bodies with cellular filopodia that were oriented perpendicularly to the direct current electric field. We show that cells of the central nervous system can respond to direct current electric fields both in terms of their morphological shape and molecular expression of certain proteins, and this in turn can help us to begin understand the mechanisms underlying the clinical benefits of direct current electric field. © The Author 2015. Published by Oxford University Press on behalf of CINP.

  19. Coordinated Operation of the Electricity and Natural Gas Systems with Bi-directional Energy Conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Zhang, Baohua; Fang, Jiakun

    2017-01-01

    A coordinated operation of the natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables. This work focuses on the unified optimal operation of the integrated natural gas and electricity system considering the network...

  20. Pharmacologic versus direct-current electrical cardioversion of atrial flutter and fibrillation

    NARCIS (Netherlands)

    Van Gelder, IC; Tuinenburg, AE; Schoonderwoerd, BS; Tieleman, RG; Crijns, HJGM

    1999-01-01

    Conversion of atrial flutter and atrial fibrillation (AF) can be achieved by either pharmacologic or direct-current (DC) electrical cardioversion. DC electrical cardioversion is more effective and restores sinus rhythm instantaneously; however, general anesthesia is necessary, which can cause severe

  1. Deconstructing field-induced ketene isomerization through Lagrangian descriptors.

    Science.gov (United States)

    Craven, Galen T; Hernandez, Rigoberto

    2016-02-07

    The time-dependent geometrical separatrices governing state transitions in field-induced ketene isomerization are constructed using the method of Lagrangian descriptors. We obtain the stable and unstable manifolds of time-varying transition states as dynamic phase space objects governing configurational changes when the ketene molecule is subjected to an oscillating electric field. The dynamics of the isomerization reaction are modeled through classical trajectory studies on the Gezelter-Miller potential energy surface and an approximate dipole moment model which is coupled to a time-dependent electric field. We obtain a representation of the reaction geometry, over varying field strengths and oscillation frequencies, by partitioning an initial phase space into basins labeled according to which product state is reached at a given time. The borders between these basins are in agreement with those obtained using Lagrangian descriptors, even in regimes exhibiting chaotic dynamics. Major outcomes of this work are: validation and extension of a transition state theory framework built from Lagrangian descriptors, elaboration of the applicability for this theory to periodically- and aperiodically-driven molecular systems, and prediction of regimes in which isomerization of ketene and its derivatives may be controlled using an external field.

  2. A direct and at nanometer scale study of electrical charge distribution on membranes of alive cells

    Directory of Open Access Journals (Sweden)

    Marlière Christian

    2016-01-01

    Full Text Available In this paper is presented an innovative method to map in-vivo and at nanometer scale the electrical charge distribution on membranes of alive cells. It relies on a new atomic force microscopy (AFM mode based on an electro-mechanical coupling effect. Furthermore, an additional electrical signal detected by both the deflection of the AFM cantilever and simultaneous direct current measurements was detected at low scanning rates. It was attributed to the detection of the current stemming from ionic channels. It opens a new way to directly investigate in situ biological electrical surface processes involved in bacterial adhesion, biofilm formation, microbial fuel cells, etc.

  3. Proposal for a directive for the promotion of electricity based on renewable energy sources

    International Nuclear Information System (INIS)

    2000-04-01

    The amended ''Directives concerning common rules for the internal markets in electricity and natural gas'', adopted in June 2003, organizes the future framework of electricity and gas, making all European consumers eligible, from 2004 onwards and at the latest by 2007 for the domestic sector, as well as integrating some components related to general interest services. Energie-Cites gives in this document its opinion and its expectations concerning this proposal for a directive for the promotion of electricity based on renewable energy sources. (A.L.B.)

  4. Direct electrical arc ignition of hybrid rocket motors

    Science.gov (United States)

    Judson, Michael I., Jr.

    Hybrid rockets motors provide distinct safety advantages when compared to traditional liquid or solid propellant systems, due to the inherent stability and relative inertness of the propellants prior to established combustion. As a result of this inherent propellant stability, hybrid motors have historically proven difficult to ignite. State of the art hybrid igniter designs continue to require solid or liquid reactants distinct from the main propellants. These ignition methods however, reintroduce to the hybrid propulsion system the safety and complexity disadvantages associated with traditional liquid or solid propellants. The results of this study demonstrate the feasibility of a novel direct electrostatic arc ignition method for hybrid motors. A series of small prototype stand-alone thrusters demonstrating this technology were successfully designed and tested using Acrylonitrile Butadiene Styrene (ABS) plastic and Gaseous Oxygen (GOX) as propellants. Measurements of input voltage and current demonstrated that arc-ignition will occur using as little as 10 watts peak power and less than 5 joules total energy. The motor developed for the stand-alone small thruster was adapted as a gas generator to ignite a medium-scale hybrid rocket motor using nitrous oxide /and HTPB as propellants. Multiple consecutive ignitions were performed. A large data set as well as a collection of development `lessons learned' were compiled to guide future development and research. Since the completion of this original groundwork research, the concept has been developed into a reliable, operational igniter system for a 75mm hybrid motor using both gaseous oxygen and liquid nitrous oxide as oxidizers. A development map of the direct spark ignition concept is presented showing the flow of key lessons learned between this original work and later follow on development.

  5. Gigantic magnetoelectric effect caused by magnetic-field-induced canted antiferromagnetic-paramagnetic transition in quasi-two-dimensional Ca2CoSi2O7 crystal

    Science.gov (United States)

    Akaki, M.; Tozawa, J.; Akahoshi, D.; Kuwahara, H.

    2009-05-01

    We have investigated the magnetic and dielectric properties of Ca2CoSi2O7 crystal. The dielectricity and magnetism of Ca2CoSi2O7 are strongly coupled below a canted antiferromagnetic transition temperature (TN). Magnetic fields induce electric polarization below TN. Interestingly, the magnetic-field-induced electric polarization is detected even without poling electric fields. Below TN, a canted antiferromagnetic-paramagnetic transition is induced by magnetic fields. The large magnetocapacitance is observed around TN. The origin of the large magnetocapacitance is due to the magnetic-field-induced the canted antiferromagnetic-paramagnetic transition.

  6. Thermal and electrical energy yield analysis of a directly water cooled photovoltaic module

    Directory of Open Access Journals (Sweden)

    Mtunzi Busiso

    2016-01-01

    Full Text Available Electrical energy of photovoltaic modules drops by 0.5% for each degree increase in temperature. Direct water cooling of photovoltaic modules was found to give improved electrical and thermal yield. A prototype was put in place to analyse the field data for a period of a year. The results showed an initial high performance ratio and electrical power output. The monthly energy saving efficiency of the directly water cooled module was found to be approximately 61%. The solar utilisation of the naturally cooled photovoltaic module was found to be 8.79% and for the directly water cooled module its solar utilisation was 47.93%. Implementation of such systems on households may reduce the load from the utility company, bring about huge savings on electricity bills and help in reducing carbon emissions.

  7. Physicochemical Properties of Biopolymer Hydrogels Treated by Direct Electric Current

    Directory of Open Access Journals (Sweden)

    Żaneta Król

    2016-07-01

    Full Text Available The objective of this study was to evaluate the changes within the physicochemical properties of gelatine (2%; 4%; 8%, carrageenan (1.5%; 2%; 2.5% and sodium alginate (0.75%; 1%; 1.25% hydrogels with different sodium chloride concentrations that were triggered by applying direct current (DC of 400 mA for a duration of five minutes. There were three types of gels prepared for the purpose of the study: C, control; H, gels on the basis of hydrosols that were treated with DC; and G, gels treated with DC. In the course of the study, the authors carried out the following analyses: Texture Profile Analysis (TPA, Fourier Transform Infrared spectroscopy (FTIR, Scanning Electron Microscopy (SEM and Swelling Ratio (SR. Furthermore, the color and pH of hydrogels were measured. The FTIR spectra showed that the structures of gelatine, carrageenan and sodium alginate do not significantly change upon applying DC. The results of TPA, SR, color and pH measurement indicate that hydrogels’ properties are significantly dependent on the type of polymer, its concentration and the type of the gel. By changing those parameters, the characteristics of such gels can be additionally tuned, which extends their applicability, e.g., in the food industry. Moreover, the analysis revealed that SR of H gel gelatine after 72 h of storage was 1.84-times higher than SR of the control sample, which indicated that this gel may be considered as a possible component for wound dressing materials.

  8. Hall field-induced magnetoresistance oscillations of a two-dimensional electron system

    International Nuclear Information System (INIS)

    Kunold, A.; Torres, M.

    2008-01-01

    We develop a model of the nonlinear response to a dc electrical current of a two-dimensional electron system (2DES) placed on a magnetic field. Based on the exact solution to the Schroedinger equation in arbitrarily strong electric and magnetic fields, and separating the relative and guiding center coordinates, a Kubo-like formula for the current is worked out as a response to the impurity scattering. Self-consistent expressions determine the longitudinal and Hall components of the electric field in terms of the dc current. The differential resistivity displays strong Hall field-induced oscillations, in agreement with the main features of the phenomenon observed in recent experiments

  9. Differential and directional effects of perfusion on electrical and thermal conductivities in liver.

    Science.gov (United States)

    Podhajsky, Ronald J; Yi, Ming; Mahajan, Roop L

    2009-01-01

    Two different measurement probes--an electrical probe and a thermal conductivity probe--were designed, fabricated, calibrated, and used in experimental studies on a pig liver model that was designed to control perfusion rates. These probes were fabricated by photolithography and mounted in 1.5-mm diameter catheters. We measured the local impedance and thermal conductivity, respectively, of the artificially perfused liver at different flow rates and, by rotating the probes, in different directions. The results show that both the local electrical conductivity and the thermal conductivity varied location to location, that thermal conductivity increased with decreased distance to large blood vessels, and that significant directional differences exist in both electrical and thermal conductivities. Measurements at different perfusion rates demonstrated that both the local electrical and local thermal conductivities increased linearly with the square root of perfusion rate. These correlations may be of great value to many energy-based biomedical applications.

  10. THE MAIN DIRECTIONS OF IMPROVING THE EFFICIENCY OF PRODUCTION, TRANSMISSION AND DISTRIBUTION OF ELECTRICAL ENERGY

    Directory of Open Access Journals (Sweden)

    I. V. Zhezhelenko

    2018-01-01

    Full Text Available The main directions of increase of efficiency of production, transmission and distribution of electric energy have been formulated. The relation between the values of electricity losses during transmission via power grids of different countries and the level of the economies of these countries characterized by the value of gross domestic product at purchasing power parity per capita has been established. In the countries with a gross domestic product at purchasing power parity per capita less than 20 thousand US dollars electricity losses during its transmission via power grids are 1.5–2.5 times more than the ones transmitted via power grids of the industrialized countries where the specified purchasing power parity is in the range of 30.4–54.5 thousand US dollars. In the countries with more developed economies the technical culture of production, transmission and distribution of electricity is higher; the modern control systems of operation modes of electrical networks are used as well as of monitoring and accounting of electricity; also there are solvent and disciplined consumers in such countries as well as clear regulatory framework and tariff regulation system. However, the process of transmission and distribution of electricity is effective if not only low relative losses take place, but the normal (contractual requirements for carrying capacity, quality and reliability of electricity supply are provided. The possibility of analytical determination of the optimum value of reserve capacity of power plants providing the required level of reliability of the power system has been considered.

  11. The difference between electrical microstimulation and direct electrical stimulation - towards new opportunities for innovative functional brain mapping?

    Science.gov (United States)

    Vincent, Marion; Rossel, Olivier; Hayashibe, Mitsuhiro; Herbet, Guillaume; Duffau, Hugues; Guiraud, David; Bonnetblanc, François

    2016-04-01

    Both electrical microstimulation (EMS) and direct electrical stimulation (DES) of the brain are used to perform functional brain mapping. EMS is applied to animal fundamental neuroscience experiments, whereas DES is performed in the operating theatre on neurosurgery patients. The objective of the present review was to shed new light on electrical stimulation techniques in brain mapping by comparing EMS and DES. There is much controversy as to whether the use of DES during wide-awake surgery is the 'gold standard' for studying the brain function. As part of this debate, it is sometimes wrongly assumed that EMS and DES induce similar effects in the nervous tissues and have comparable behavioural consequences. In fact, the respective stimulation parameters in EMS and DES are clearly different. More surprisingly, there is no solid biophysical rationale for setting the stimulation parameters in EMS and DES; this may be due to historical, methodological and technical constraints that have limited the experimental protocols and prompted the use of empirical methods. In contrast, the gap between EMS and DES highlights the potential for new experimental paradigms in electrical stimulation for functional brain mapping. In view of this gap and recent technical developments in stimulator design, it may now be time to move towards alternative, innovative protocols based on the functional stimulation of peripheral nerves (for which a more solid theoretical grounding exists).

  12. Analysis of critical thinking ability in direct current electrical problems solving

    Science.gov (United States)

    Hartono; Sunarno, Widha; Sarwanto; Arya Nugraha, Dewanta

    2017-11-01

    This study concern on analyzing the ability of students in critical thinking skills on the subject matter of direct current electricity. Samples were taken using purposive random sampling consisted of 32 students of grade XI, Multimedia 1, SMK Negeri 3 Surakarta in academic year 2016/2017. This study used descriptive quantitative method. The data were collected using tests and interviews regarding the subject matter of direct current electricity. Based on the results, students are getting some difficulties in solving problem in indicator 4. The average of students’ correct answer is 62.8%.

  13. Research Capabilities Directed to all Electric Engineering Teachers, from an Alternative Energy Model

    Directory of Open Access Journals (Sweden)

    Víctor Hugo Ordóñez Navea

    2017-08-01

    Full Text Available The purpose of this work was to contemplate research capabilities directed to all electric engineering teachers from an alternative energy model intro the explanation of a semiconductor in the National Training Program in Electricity. Some authors, such as. Vidal (2016, Atencio (2014 y Camilo (2012 point out to technological applications with semiconductor electrical devices. In this way; a diagnostic phase is presented, held on this field research as a descriptive type about: a how to identify the necessities of alternative energies, and b The research competences in the alternatives energies of researcher from a solar cell model, to boost and innovate the academic praxis and technologic ingenuity. Themselves was applied a survey for a group of 15 teachers in the National Program of Formation in electricity to diagnose the deficiencies in the research area of alternatives energies. The process of data analysis was carried out through descriptive statistic. Later the conclusions are presented the need to generate strategies for stimulate and propose exploration of alternatives energies to the development of research competences directed to the teachers of electrical engineering for develop the research competences in the enforcement of the teachers exercise for the electric engineering, from an alternative energy model and boost the technologic research in the renewal energies field.

  14. Bi-directional causality in California's electricity and natural-gas markets

    International Nuclear Information System (INIS)

    Woo, Chi-Keung; Olson, Arne; Horowitz, Ira; Luk, Stephen

    2006-01-01

    The Granger instantaneous-causality test is applied to explore the potential causal relationships between wholesale electricity and natural-gas prices in California. The test shows these relationships to be bi-directional, and reveals California's electricity and natural-gas markets to be as inextricably intertwined as casual observation and theoretical considerations would suggest they ought to be. This meshing of markets exacerbated the effects of California's natural-gas crisis on the contemporaneous electricity crisis, while concurrently the electricity crisis may have contributed to the dysfunction in the national-gas market and helped to precipitate the natural-gas crisis. The finding supports an integrated approach, as opposed to a piecemeal approach, for formulating energy policy recommendations, not just in California but in the world at large

  15. Blood Stage Plasmodium falciparum Exhibits Biological Responses to Direct Current Electric Fields.

    Directory of Open Access Journals (Sweden)

    Lorena M Coronado

    Full Text Available The development of resistance to insecticides by the vector of malaria and the increasingly faster appearance of resistance to antimalarial drugs by the parasite can dangerously hamper efforts to control and eradicate the disease. Alternative ways to treat this disease are urgently needed. Here we evaluate the in vitro effect of direct current (DC capacitive coupling electrical stimulation on the biology and viability of Plasmodium falciparum. We designed a system that exposes infected erythrocytes to different capacitively coupled electric fields in order to evaluate their effect on P. falciparum. The effect on growth of the parasite, replication of DNA, mitochondrial membrane potential and level of reactive oxygen species after exposure to electric fields demonstrate that the parasite is biologically able to respond to stimuli from DC electric fields involving calcium signaling pathways.

  16. Implementation of Electricity Business Competition Framework with Economic Dispatch Direct Method

    Directory of Open Access Journals (Sweden)

    Yusra Sabri

    2012-12-01

    Full Text Available Technically, electricity business under competition structure is more complex than that of vertically integrated one. The main prolems here are how to create an applicable competition framework and to solve electric calculations very quickly to obtain an optimal energi pricing, cost of losses, congestion and transportation costs by less than 15 minutes. This paper proposes a competition framework with the electric calculations, where a bilateral contract has been accommodated. Optimal energy price in the paper is calculated based on direct method of economic dispatch to obtain the result very quickly. The proposed method has been simulated to a 4-bus system. The simulation results show that the method works well and complies with the expectation. Therefore, electric power business under competition structure can be well realized by the proposed method.

  17. Electric Vehicles in Colorado: Anticipating Consumer Demand for Direct Current Fast Charging

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Eric W. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rames, Clement L. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-07-01

    To support the State of Colorado in planning for growth in direct current fast charging (DCFC) for electric vehicles, the National Renewable Energy Laboratory (NREL) has partnered with the Regional Air Quality Council (RAQC) and the Colorado Department of Transportation (CDOT) to analyze a number of DCFC investment scenarios. NREL analyzed existing electric vehicle registration data from IHS Markit (IHS) to highlight early trends in the electric vehicle market, which were compared with sales forecasts predicting large growth in the Colorado electric vehicle market. Electric vehicle forecasts were then used to develop future DCFC scenarios to be evaluated in a simulation environment to estimate consumer benefits of the hypothetical DCFC networks in terms of increased driving range and electric vehicle miles traveled (eVMT). Simulated utilization of the hypothetical DCFC networks was analyzed for geographic trends, particularly for correlations with vehicle electric range. Finally, a subset of simulations is presented for consumers with potentially inconsistent access to charging at their home location and presumably greater reliance on public DCFC infrastructure.

  18. Thermodynamic analysis of direct expansion configurations for electricity production by LNG cold energy recovery

    International Nuclear Information System (INIS)

    Franco, Alessandro; Casarosa, Claudio

    2015-01-01

    In the present paper, after a brief review of the perspectives of the various schemes proposed for electricity generation from the regasification of Liquefied Natural Gas (LNG), a detailed analysis of two particular direct expansion solutions is proposed. The purpose is to identify the upper level of the energy that can be recovered with the aim of electricity production, using configurations with direct expansion. The analysis developed resorting to a simplified thermodynamic model, shows that using a direct expansion configurations with multistage turbine, values of power production typical of optimized ORC plant configurations (120 kJ for each kg of natural gas that flows through the plant) can be obtained. The development of a direct expansion plant with multistage turbine and internal heat recovery systems could permit to approach the production of more than 160 kJ for each kg of flowing liquefied natural gas. Considering values of the mass flow rate typical of LNG gas stations (e.g. 70 kg/s); this corresponds to an output power ranging between 8.3 MW and 11.4 MW. - Highlights: • Recovery of the cold energy contained in Liquefied Natural Gas. • Thermodynamic analysis of systems for electricity generation in regasification. • Direct expansion solutions with multistage expansion. • Comparison of direct expansion solutions with conventional ORC systems. • Power output in conditions typical of existing LNG regasification terminals

  19. Electric power generating plant having direct-coupled steam and compressed-air cycles

    Science.gov (United States)

    Drost, M.K.

    1981-01-07

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  20. Electric power generating plant having direct coupled steam and compressed air cycles

    Science.gov (United States)

    Drost, Monte K.

    1982-01-01

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  1. 75 FR 78980 - Application to Export Electric Energy; Direct Energy Marketing, Inc.

    Science.gov (United States)

    2010-12-17

    ... Marketing, Inc. AGENCY: Office of Electricity Delivery and Energy Reliability, DOE. ACTION: Notice of Application. SUMMARY: Direct Energy Marketing, Inc. (DEMI) has applied to renew its authority to transmit..., Federal power marketing agencies, and other entities within the United States. The existing international...

  2. Hybrid propulsion testing using direct-drive electrical machines for super yacht and inland shipping

    NARCIS (Netherlands)

    Paulides, J.J.H.; Djukic, N.; de Roon, J.A.; Encica, L.

    2016-01-01

    Hybrid or full electric propulsions for inland ships are becoming more popular. In these application, direct-drive PM propulsion motors are a preferred machine configuration. This paper discusses the challenges to determine the losses, as estimated with simulations, during the testing procedures of

  3. 76 FR 68634 - Airworthiness Directives; General Electric Company (GE) CF6 Turbofan Engines

    Science.gov (United States)

    2011-11-07

    ... Airworthiness Directives; General Electric Company (GE) CF6 Turbofan Engines AGENCY: Federal Aviation... ``(c) This AD applies to * * * and CF6-80A3 turbofan engines with left-hand links * * *.'' to ``(c) This AD applies to * * * and CF6-80A3 turbofan engines, including engines marked on the engine data...

  4. 2003/54/EC Directive - A new impetus for the development of competitive electricity markets

    International Nuclear Information System (INIS)

    Lungu, Ion; Manicu, Maria; Caraca, Lusine

    2004-01-01

    The political and economical transformation, followed by institutional changes occurring all over the world has led to the creation of new relationships in the electricity sector, a segment playing a vital role in the economical and social development of a country. Thus, the energy sector planning and the strict control of the state used as a means to ensure the energy security have been largely rejected. In most countries, the state has given up its price control practice on activities that were deemed competitive, subsidies have been significantly reduced or eliminated, and barriers hindering the energy trading have been eased or removed. The process of removing state intervention from the electricity markets is in full progress and is achieved through deep structural reforms covering two directions: privatisation of large state-owned companies, on one hand and, on the other hand, restructuring the industrial branches that are network-dependent. These branches are mainly restructured through separation of monopolistic activities from competitive activities, concurrently with the invalidation and/or amendment of the legislation referring to the granting of energy efficiency incentives in the sector. The paper addresses the following items: - Energy markets regulatory framework within EU; - Internal electricity market regulation in the context of the 2003/54 EC Directive; Romania engaged itself in this effort to restructuring its electricity sector. The process started in 1998 and aimed at ensuring the supply of electricity and heat under conditions of quality, fair prices and mitigated environmental impact

  5. High-performance, polymer-based direct cellular interfaces for electrical stimulation and recording

    Science.gov (United States)

    Kim, Seong-Min; Kim, Nara; Kim, Youngseok; Baik, Min-Seo; Yoo, Minsu; Kim, Dongyoon; Lee, Won-June; Kang, Dong-Hee; Kim, Sohee; Lee, Kwanghee; Yoon, Myung-Han

    2018-04-01

    Due to the trade-off between their electrical/electrochemical performance and underwater stability, realizing polymer-based, high-performance direct cellular interfaces for electrical stimulation and recording has been very challenging. Herein, we developed transparent and conductive direct cellular interfaces based on a water-stable, high-performance poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) film via solvent-assisted crystallization. The crystallized PEDOT:PSS on a polyethylene terephthalate (PET) substrate exhibited excellent electrical/electrochemical/optical characteristics, long-term underwater stability without film dissolution/delamination, and good viability for primarily cultured cardiomyocytes and neurons over several weeks. Furthermore, the highly crystallized, nanofibrillar PEDOT:PSS networks enabled dramatically enlarged surface areas and electrochemical activities, which were successfully employed to modulate cardiomyocyte beating via direct electrical stimulation. Finally, the high-performance PEDOT:PSS layer was seamlessly incorporated into transparent microelectrode arrays for efficient, real-time recording of cardiomyocyte action potentials with a high signal fidelity. All these results demonstrate the strong potential of crystallized PEDOT:PSS as a crucial component for a variety of versatile bioelectronic interfaces.

  6. Studying the field induced breakup of acoustically levitated drops

    Science.gov (United States)

    Warschat, C.; Riedel, J.

    2017-10-01

    Coulomb fission of charged droplets (The terms drop and droplet are often used synonymous. Throughout this manuscript, to avoid confusion, the terms drop and droplet will be used for liquid spheres with radii in the millimeter range and the micrometer range, respectively. In our experiments, the first correspond to the parent drop while the latter describes the ejected progeny droplets.) is a well-studied natural phenomenon. Controlled droplet fission is already successfully employed in several technological applications. Still, since the occurring surface rupture relies on the exact understanding and description of the liquid gas boundary, some details are still under debate. Most empirical systematic studies observe falling micrometer droplets passing through the electric field inside a plate capacitor. This approach, although easily applicable and reliable, limits the experimental degrees of freedom regarding the observable time and the maximum size of the drops and can only be performed in consecutive individual observations of different subsequent drops. Here we present a novel setup to study the field induced breakup of acoustically levitated drops. The design does not bear any restrictions towards the temporal window of observation, and allows handling of drops of a tunable radius ranging from 10 μm to several millimeters and a real-time monitoring of one single drop. Our comprehensive study includes a time resolved visual inspection, laser shadowgraphy, laser induced fluorescence imaging, and ambient mass spectrometric interrogation of the nascent Taylor cone. The results shown for a millimeter sized drop, previously inaccessible for Coulomb fission experiments, are mostly comparable with previous results for smaller drops. The major difference is the time scale and the threshold potential of the drop rupture. Both values, however, resemble theoretically extrapolations to the larger radius. The technique allows for a systematic study of breakup behavior of

  7. Parallel electric fields accelerating ions and electrons in the same direction

    International Nuclear Information System (INIS)

    Hultqvist, B; Lundin, R.

    1988-01-01

    In this contribution the authors present Viking observations of electrons and positive ions which move upward along the magnetic field lines with energies of the same order of magnitude. The authors propose that both ions and electrons are accelerated by an electric field which has low-frequency temporal variations such that the ions experience and average electrostatic potential drop along the magnetic field lines whereas the upward streaming electrons are accelerated in periods of downward pointing electric field which is quasi-static for the electrons and forces them to beam out of the field region before the field changes direction

  8. The directive on ''internal market of electric power'': a satisfactory balance

    International Nuclear Information System (INIS)

    1996-01-01

    The european directive on the ''internal market for electric power'' has allowed for the first time the implementation of harmonized regulations among european partners concerning the operation of electric utilities and systems in Europe, while taking into consideration the subsidiarity principles to which France is very much attached and finding an equilibrium between the status-quo based on national or regional monopolies and a global deregulation inspired by ultra-liberal views coming from Britain or the US. The main consequences on France's energy policy and organization are discussed

  9. Foreign direct investment (FDI) in energy/electricity projects in the economies in transition

    International Nuclear Information System (INIS)

    Brendow, K.

    1995-01-01

    Registered foreign direct investments (FDI) in energy/ electricity projects in central and eastern Europe and the CIS are weak and disappointing compared with expectations and business opportunities. In addition, energy FDI is highly concentrated in oil and gas exploration/extraction. FDI opportunities in electricity generation, transmission and distribution while being explored, have not been implemented, mostly for legislation restriction reasons towards foreign participation. The major issue appears to be the extent of privatization of this politically and socially sensitive industry. Progress are made in Hungary, Poland and the Czech Republic. A significant breakthrough depends on political stability, economic recovery and progress in privatization. 2 figs

  10. Effects of the Electric Field on the Direct Loss Asymmetries on TJ-II

    International Nuclear Information System (INIS)

    Guasp, J.

    1997-01-01

    The effects of the radial electric fields upon the direct loss asymmetries have been studied for low energy (0.1-1keV)ions. The analysis shows the permanence of the predominant downwards asymmetry that is only slightly modified in the poloidal rotation direction for moderate electric fields. In TJ-II this poloidal rotation is directed towards decreasing poloidal angles for positive (outward) electric fields and the ions drift along the same direction. Nevertheless for very strong fields the lost particles concentrate in the extreme plasma periphery (at the same time that the rate loss decreases strongly) and have no time, any more, to feel the poloidal rotation before escaping. The gaps between the TF coils receive the most of the losses. On the Vacuum Vessel the losses have a very strong concentration along the Hard Core, in particular on the PLT-2 plane plate (the one that is placed down at Phi=0 degree centigree) and a moderate preference for the 2''nd toroidal octant of each period. The poloidal rotation is much less visible than on the plasma border. The resulting power loads are small. (Author)

  11. Evidence for a Field-Induced Quantum Spin Liquid in α -RuCl3

    Science.gov (United States)

    Baek, S.-H.; Do, S.-H.; Choi, K.-Y.; Kwon, Y. S.; Wolter, A. U. B.; Nishimoto, S.; van den Brink, Jeroen; Büchner, B.

    2017-07-01

    We report a 35Cl nuclear magnetic resonance study in the honeycomb lattice α -RuCl3 , a material that has been suggested to potentially realize a Kitaev quantum spin liquid (QSL) ground state. Our results provide direct evidence that α -RuCl3 exhibits a magnetic-field-induced QSL. For fields larger than ˜10 T , a spin gap opens up while resonance lines remain sharp, evidencing that spins are quantum disordered and locally fluctuating. The spin gap increases linearly with an increasing magnetic field, reaching ˜50 K at 15 T, and is nearly isotropic with respect to the field direction. The unusual rapid increase of the spin gap with increasing field and its isotropic nature are incompatible with conventional magnetic ordering and, in particular, exclude that the ground state is a fully polarized ferromagnet. The presence of such a field-induced gapped QSL phase has indeed been predicted in the Kitaev model.

  12. In vitro effects of direct current electric fields on adipose-derived stromal cells.

    Science.gov (United States)

    Hammerick, Kyle E; Longaker, Michael T; Prinz, Fritz B

    2010-06-18

    Endogenous electric fields play an important role in embryogenesis, regeneration, and wound repair and previous studies have shown that many populations of cells, leukocytes, fibroblasts, epithelial cells, and endothelial cells, exhibit directed migration in response to electric fields. As regenerative therapies continue to explore ways to control mesenchymal progenitor cells to recreate desirable tissues, it is increasingly necessary to characterize the vast nature of biological responses imposed by physical phenomena. Murine adipose-derived stromal cells (mASCs) migrated toward the cathode in direct current (DC) fields of physiologic strength and show a dose dependence of migration rate to stronger fields. Electric fields also caused mASCs to orient perpendicularly to the field vector and elicited a transient increase in cytosolic calcium. Additionally, their galvanotactic response appears to share classic chemotactic signaling pathways that are involved in the migration of other cell types. Galvanotaxis is one predominant result of electric fields on mASCs and it may be exploited to engineer adult stem cell concentrations and locations within implanted grafts or toward sites of wound repair. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  13. High electrical conductivity in out of plane direction of electrodeposited Bi2Te3 films

    Directory of Open Access Journals (Sweden)

    Miguel Muñoz Rojo

    2015-08-01

    Full Text Available The out of plane electrical conductivity of highly anisotropic Bi2Te3 films grown via electro-deposition process was determined using four probe current-voltage measurements performed on 4.6 - 7.2 μm thickness Bi2Te3 mesa structures with 80 - 120 μm diameters sandwiched between metallic film electrodes. A three-dimensional finite element model was used to predict the electric field distribution in the measured structures and take into account the non-uniform distribution of the current in the electrodes in the vicinity of the probes. The finite-element modeling shows that significant errors could arise in the measured film electrical conductivity if simpler one-dimensional models are employed. A high electrical conductivity of (3.2 ± 0.4 ⋅ 105 S/m is reported along the out of plane direction for Bi2Te3 films highly oriented in the [1 1 0] direction.

  14. Electric Mars: The first direct measurement of an upper limit for the Martian "polar wind" electric potential

    Science.gov (United States)

    Collinson, Glyn; Mitchell, David; Glocer, Alex; Grebowsky, Joseph; Peterson, W. K.; Connerney, Jack; Andersson, Laila; Espley, Jared; Mazelle, Christian; Sauvaud, Jean-André; Fedorov, Andrei; Ma, Yingjuan; Bougher, Steven; Lillis, Robert; Ergun, Robert; Jakosky, Bruce

    2015-11-01

    An important mechanism in the generation of polar wind outflow is the ambipolar electric potential which assists ions in overcoming gravity and is a key mechanism for Terrestrial ionospheric escape. At Mars, open field lines are not confined to the poles, and outflow of ionospheric electrons is observed far into the tail. It has thus been hypothesized that a similar electric potential may be present at Mars, contributing to global ionospheric loss. However, no direct measurements of this potential have been made. In this pilot study, we examine photoelectron spectra measured by the Solar Wind Electron Analyzer instrument on the NASA Mars Atmosphere and Volatile EvolutioN (MAVEN) Mars Scout to put an initial upper bound on the total potential drop in the ionosphere of Mars of Φ♂ ≾⊥ 2V , with the possibility of a further ≾4.5 V potential drop above this in the magnetotail. If the total potential drop was close to the upper limit, then strong outflows of major ionospheric species (H+, O+, and O2+) would be expected. However, if most of the potential drop is confined below the spacecraft, as expected by current theory, then such a potential would not be sufficient on its own to accelerate O2+ to escape velocities, but would be sufficient for lighter ions. However, any potential would contribute to atmospheric loss through the enhancement of Jeans escape.

  15. Direct electrical stimulation of human cortex evokes high gamma activity that predicts conscious somatosensory perception

    Science.gov (United States)

    Muller, Leah; Rolston, John D.; Fox, Neal P.; Knowlton, Robert; Rao, Vikram R.; Chang, Edward F.

    2018-04-01

    Objective. Direct electrical stimulation (DES) is a clinical gold standard for human brain mapping and readily evokes conscious percepts, yet the neurophysiological changes underlying these percepts are not well understood. Approach. To determine the neural correlates of DES, we stimulated the somatosensory cortex of ten human participants at frequency-amplitude combinations that both elicited and failed to elicit conscious percepts, meanwhile recording neural activity directly surrounding the stimulation site. We then compared the neural activity of perceived trials to that of non-perceived trials. Main results. We found that stimulation evokes distributed high gamma activity, which correlates with conscious perception better than stimulation parameters themselves. Significance. Our findings suggest that high gamma activity is a reliable biomarker for perception evoked by both natural and electrical stimuli.

  16. Direct nanoscale imaging of evolving electric field domains in quantum structures.

    Science.gov (United States)

    Dhar, Rudra Sankar; Razavipour, Seyed Ghasem; Dupont, Emmanuel; Xu, Chao; Laframboise, Sylvain; Wasilewski, Zbig; Hu, Qing; Ban, Dayan

    2014-11-28

    The external performance of quantum optoelectronic devices is governed by the spatial profiles of electrons and potentials within the active regions of these devices. For example, in quantum cascade lasers (QCLs), the electric field domain (EFD) hypothesis posits that the potential distribution might be simultaneously spatially nonuniform and temporally unstable. Unfortunately, there exists no prior means of probing the inner potential profile directly. Here we report the nanoscale measured electric potential distribution inside operating QCLs by using scanning voltage microscopy at a cryogenic temperature. We prove that, per the EFD hypothesis, the multi-quantum-well active region is indeed divided into multiple sections having distinctly different electric fields. The electric field across these serially-stacked quantum cascade modules does not continuously increase in proportion to gradual increases in the applied device bias, but rather hops between discrete values that are related to tunneling resonances. We also report the evolution of EFDs, finding that an incremental change in device bias leads to a hopping-style shift in the EFD boundary--the higher electric field domain expands at least one module each step at the expense of the lower field domain within the active region.

  17. Inertial confinement fusion with direct electric generation by magnetic flux comparession

    International Nuclear Information System (INIS)

    Lasche, G.P.

    1983-01-01

    A high-power-density laser-fusion-reactor concept in investigated in which directed kinetic enery imparted to a large mass of liquid lithium--in which the fusion target is centrally located--is maximized. In turn, this kinetic energy is converted directly to electricity with, potentially, very high efficiency by work done against a pulsed magnetic field applied exterior to the lithium. Because the concept maximizes the blanket thickness per unit volume of lithium, neutron-induced radioactivities in the reaction chamber wall can be many orders of magnitude less than is typical of D-T fusion reactor concepts

  18. The space-time evolution of an electrical discharge directed by a laser spark

    International Nuclear Information System (INIS)

    Asinovskii, E.I.; Vasilyak, L.M.; Unkovskii, S.Yu.

    1992-01-01

    The study of electrical discharges directed by a laser spark has been made necessary by the creation of new types of switches, plasma antennas, and lightning rods, channels for the transport of charged particle beams in inertial thermonuclear fusion devices, and also for modeling the processes in streak lightning. For the most part, previous studies have explored the feasibility of creating such discharges, depending on experimental conditions, and proposed possible mechanisms for the development of discharges, e.g., the stepwise nature of its propagation. A model was proposed in which the discharge front propagates as an ionization wave. This model was based on measurements of the electric potential along the trajectory of a directed discharge. To construct a model and obtain directed discharges with prescribed parameters, one must know the mechanisms of discharge development. In this work, the authors report the results of an electrooptical study of the origin and motion of luminous fronts of ionization waves in an electrical discharge during its initiation, both for a single breakdown site and for a long laser spark with a large number of laser breakdown sites. Results are presented of our study of the stability of a discharge for a current flow of long duration

  19. Electromagnetic field induced biological effects in humans.

    Science.gov (United States)

    Kaszuba-Zwoińska, Jolanta; Gremba, Jerzy; Gałdzińska-Calik, Barbara; Wójcik-Piotrowicz, Karolina; Thor, Piotr J

    2015-01-01

    Exposure to artificial radio frequency electromagnetic fields (EMFs) has increased significantly in recent decades. Therefore, there is a growing scientific and social interest in its influence on health, even upon exposure significantly below the applicable standards. The intensity of electromagnetic radiation in human environment is increasing and currently reaches astronomical levels that had never before experienced on our planet. The most influential process of EMF impact on living organisms, is its direct tissue penetration. The current established standards of exposure to EMFs in Poland and in the rest of the world are based on the thermal effect. It is well known that weak EMF could cause all sorts of dramatic non-thermal effects in body cells, tissues and organs. The observed symptoms are hardly to assign to other environmental factors occurring simultaneously in the human environment. Although, there are still ongoing discussions on non-thermal effects of EMF influence, on May 31, 2011--International Agency for Research on Cancer (IARC)--Agenda of World Health Organization (WHO) has classified radio electromagnetic fields, to a category 2B as potentially carcinogenic. Electromagnetic fields can be dangerous not only because of the risk of cancer, but also other health problems, including electromagnetic hypersensitivity (EHS). Electromagnetic hypersensitivity (EHS) is a phenomenon characterized by the appearance of symptoms after exposure of people to electromagnetic fields, generated by EHS is characterized as a syndrome with a broad spectrum of non-specific multiple organ symptoms including both acute and chronic inflammatory processes located mainly in the skin and nervous systems, as well as in respiratory, cardiovascular systems, and musculoskeletal system. WHO does not consider the EHS as a disease-- defined on the basis of medical diagnosis and symptoms associated with any known syndrome. The symptoms may be associated with a single source of EMF

  20. Optically resonant magneto-electric cubic nanoantennas for ultra-directional light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Sikdar, Debabrata, E-mail: debabrata.sikdar@monash.edu; Premaratne, Malin [Advanced Computing and Simulation Laboratory (A chi L), Department of Electrical and Computer Systems Engineering, Monash University, Clayton 3800, Victoria (Australia); Cheng, Wenlong [Department of Chemical Engineering, Faculty of Engineering, Monash University, Clayton 3800, Victoria (Australia); The Melbourne Centre for Nanofabrication, 151 Wellington Road, Clayton 3168, Victoria (Australia)

    2015-02-28

    Cubic dielectric nanoparticles are promising candidates for futuristic low-loss, ultra-compact, nanophotonic applications owing to their larger optical coefficients, greater packing density, and relative ease of fabrication as compared to spherical nanoparticles; besides possessing negligible heating at nanoscale in contrast to their metallic counterparts. Here, we present the first theoretical demonstration of azimuthally symmetric, ultra-directional Kerker's-type scattering of simple dielectric nanocubes in visible and near-infrared regions via simultaneous excitation and interference of optically induced electric- and magnetic-resonances up to quadrupolar modes. Unidirectional forward-scattering by individual nanocubes is observed at the first generalized-Kerker's condition for backward-scattering suppression, having equal electric- and magnetic-dipolar responses. Both directionality and magnitude of these unidirectional-scattering patterns get enhanced where matching electric- and magnetic-quadrupolar responses spectrally overlap. While preserving azimuthal-symmetry and backscattering suppression, a nanocube homodimer provides further directionality improvement for increasing interparticle gap, but with reduced main-lobe magnitude due to emergence of side-scattering lobes from diffraction-grating effect. We thoroughly investigate the influence of interparticle gap on scattering patterns and propose optimal range of gap for minimizing side-scattering lobes. Besides suppressing undesired side-lobes, significant enhancement in scattering magnitude and directionality is attained with increasing number of nanocubes forming a linear chain. Optimal directionality, i.e., the narrowest main-scattering lobe, is found at the wavelength of interfering quadrupolar resonances; whereas the largest main-lobe magnitude is observed at the wavelength satisfying the first Kerker's condition. These unique optical properties of dielectric nanocubes thus can

  1. In vitro effect of direct current electrical stimulation on rat mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Sahba Mobini

    2017-01-01

    Full Text Available Background Electrical stimulation (ES has been successfully used to treat bone defects clinically. Recently, both cellular and molecular approaches have demonstrated that ES can change cell behavior such as migration, proliferation and differentiation. Methods In the present study we exposed rat bone marrow- (BM- and adipose tissue- (AT- derived mesenchymal stem cells (MSCs to direct current electrical stimulation (DC ES and assessed temporal changes in osteogenic differentiation. We applied 100 mV/mm of DC ES for 1 h per day for three, seven and 14 days to cells cultivated in osteogenic differentiation medium and assessed viability and calcium deposition at the different time points. In addition, expression of osteogenic genes, Runx2, Osteopontin, and Col1A2 was assessed in BM- and AT-derived MSCs at the different time points. Results Results showed that ES changed osteogenic gene expression patterns in both BM- and AT-MSCs, and these changes differed between the two groups. In BM-MSCs, ES caused a significant increase in mRNA levels of Runx2, Osteopontin and Col1A2 at day 7, while in AT-MSCs, the increase in Runx2 and Osteopontin expression were observed after 14 days of ES. Discussion This study shows that rat bone marrow- and adipose tissue-derived stem cells react differently to electrical stimuli, an observation that could be important for application of electrical stimulation in tissue engineering.

  2. Electric Vehicle Longitudinal Stability Control Based on a New Multimachine Nonlinear Model Predictive Direct Torque Control

    Directory of Open Access Journals (Sweden)

    M’hamed Sekour

    2017-01-01

    Full Text Available In order to improve the driving performance and the stability of electric vehicles (EVs, a new multimachine robust control, which realizes the acceleration slip regulation (ASR and antilock braking system (ABS functions, based on nonlinear model predictive (NMP direct torque control (DTC, is proposed for four permanent magnet synchronous in-wheel motors. The in-wheel motor provides more possibilities of wheel control. One of its advantages is that it has low response time and almost instantaneous torque generation. Moreover, it can be independently controlled, enhancing the limits of vehicular control. For an EV equipped with four in-wheel electric motors, an advanced control may be envisaged. Taking advantage of the fast and accurate torque of in-wheel electric motors which is directly transmitted to the wheels, a new approach for longitudinal control realized by ASR and ABS is presented in this paper. In order to achieve a high-performance torque control for EVs, the NMP-DTC strategy is proposed. It uses the fuzzy logic control technique that determines online the accurate values of the weighting factors and generates the optimal switching states that optimize the EV drives’ decision. The simulation results built in Matlab/Simulink indicate that the EV can achieve high-performance vehicle longitudinal stability control.

  3. The direct writing and focusing of nanoparticles generated by an electrical discharge

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, E., E-mail: ems2g09@soton.ac.uk; Praeger, M. [University of Southampton, Optoelectronics Research Centre (United Kingdom); Vaughan, A. S. [University of Southampton, Electronics and Computer Science (United Kingdom); Stewart, W.; Loh, W. H. [University of Southampton, Optoelectronics Research Centre (United Kingdom)

    2012-11-15

    Direct writing aims to deposit materials onto substrates in localised positions. In this paper, we demonstrate a new method for direct writing of nanoparticles at ambient-air-pressure. An electrical discharge is used to generate gold nanoparticles of the order of 10 nm diameter, which are then transported and 'focused' by an electric field in air, through the process of electric field-assisted diffusion, as opposed to normal ballistic focusing since the mean free path in air is very short. This process is novel and allows for practical normal atmospheric-pressure focused deposition of nanoparticles. The focusing mechanism is capable of producing patterned arrays of deposited nanoparticles with widths that are less than 10 % of the diameter of the focusing apparatus; in the present experimental configuration, gold spots with diameters of a few tens of micrometres were achieved, with ultimate size being limited by transverse diffusion and by charged particle mutual repulsion. In this study, the process of generating nanoparticles from bulk material, transporting and focusing these particles takes place in one operation, which is a key advantage in rapid prototyping and manufacturing techniques.

  4. Intraoperative direct electrical stimulations of central nervous system during surgery of gliomas near eloquent areas

    Directory of Open Access Journals (Sweden)

    WANG Wei-min

    2012-12-01

    Full Text Available Objective To report our experiences of direct cortical stimulation in surgery of gliomas located in eloquent areas. Methods Clinical data of 157 patients with gliomas underwent awake craniotomy with the direct electrical stimulation for functional mapping of the eloquent areas were analysed retrospectively. Results Negative cortical stimulation was found in 4 patients, and positive cortical stimulation was achieved in 153 patients (97.45% . Four hundred and ninty -six cortical sites in 139 patients were detected for motor response by direct electrical stimulation, 70 sites in 21 patients for sensory, 112 sites in 91 patients for language (such as counting and naming. The positive areas of counting disturbance were mainly seen at the lower part of left precentral gyri operculum of left inferior frontal gyri, triangular part of left inferior frontal gyri, posterior part of left middle frontal gyri, and posterior part of left superior frontal gyri. Postoperative MRI showed 92 patients (58.60% achieved total resection, 55 cases (35.03% subtotal and 10 cases (6.37% partial. One hundred and ten patients (70.06% were diagnosed as having low grade glimas, including 71 cases of astrocytoma, 26 cases of oligodendroglioma, and 13 cases of mixed astro ? oligodendroglioma, 47 patients (29.94% were high grade gliomas, including 19 cases of glioblastoma, 15 cases of anaplastic astrocytoma, and 13 cases of anaplastic oligodendroglioma. After operation 53 patients (33.76% occurred transient postoperative paralysis, 39 patients (24.84% transient language disturbance and 4 patients (2.55% permanent neurological deficits. Conclusion Intraoperative direct electrical stimulation is a reliable, precise and safety method for functional mapping of the eloquent areas. This technique allows us to achieve 'maximal safety resection' in glioma surgery.

  5. Rectifying the Optical-Field-Induced Current in Dielectrics: Petahertz Diode.

    Science.gov (United States)

    Lee, J D; Yun, Won Seok; Park, Noejung

    2016-02-05

    Investigating a theoretical model of the optical-field-induced current in dielectrics driven by strong few-cycle laser pulses, we propose an asymmetric conducting of the current by forming a heterojunction made of two distinct dielectrics with a low hole mass (m_{h}^{*}≪m_{e}^{*}) and low electron mass (m_{e}^{*}≪m_{h}^{*}), respectively. This proposition introduces the novel concept of a petahertz (10^{15}  Hz) diode to rectify the current in the petahertz domain, which should be a key ingredient for the electric signal manipulation of future light-wave electronics. Further, we suggest the candidate dielectrics for the heterojunction.

  6. Electric Signals Regulate the Directional Migration of Oligodendrocyte Progenitor Cells (OPCs via β1 Integrin

    Directory of Open Access Journals (Sweden)

    Bangfu Zhu

    2016-11-01

    Full Text Available The guided migration of neural cells is essential for repair in the central nervous system (CNS. Oligodendrocyte progenitor cells (OPCs will normally migrate towards an injury site to re-sheath demyelinated axons; however the mechanisms underlying this process are not well understood. Endogenous electric fields (EFs are known to influence cell migration in vivo, and have been utilised in this study to direct the migration of OPCs isolated from neonatal Sprague-Dawley rats. The OPCs were exposed to physiological levels of electrical stimulation, and displayed a marked electrotactic response that was dependent on β1 integrin, one of the key subunits of integrin receptors. We also observed that F-actin, an important component of the cytoskeleton, was re-distributed towards the leading edge of the migrating cells, and that this asymmetric rearrangement was associated with β1 integrin function.

  7. Foreign direct investments (FDI) in energy and electricity projects in the economies in transition

    International Nuclear Information System (INIS)

    Brendow, K.

    1996-01-01

    Registered foreign direct investments (or equity finance) in energy and electricity projects in central and eastern Europe (CEE) and the Commonwealth of Independent States (CIS) presently stand at about US$ 3 billion (flows) and US$ 5.5 billion (stock). This is insignificant compared with world FDI and disappointing compared with expectations and business opportunities. In addition, energy FDI is concentrated in oil and gas exploration/extraction, primarily in Russia, Kazakhstan and Azerbaijan. FDI opportunities in electricity generation, transmission and distribution while being explored (see list), have not been implemented: legislation was either restrictive as regards foreign participation, or not yet finalized, or not yet enacted. The major issue at present appears to be the extent of privatisation of this politically and socially sensitive industry. 1995 will see progress in Hungary, Poland and the Czech Republic. Related FDI would, however, still be modest. A significant breakthrough depends on political stability, economic recovery and progress in privatisation. (author)

  8. Coordinated Operation of the Electricity and Natural Gas Systems with Bi-directional Energy Conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Zhang, Baohua; Fang, Jiakun

    2017-01-01

    A coordinated operation of the natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables. This work focuses on the unified optimal operation of the integrated natural gas and electricity system considering the network...... constraints in both systems. An iterative method is proposed to deal with the nonlinearity in the proposed model. The models of the natural gas and power system are linearized in every iterative step. Simulation results demonstrate the effectiveness of the approach. Applicability of the proposed method...... is tested in the sample case. Finally, the effect of Power to Gas (P2G) on the daily economic dispatch is also investigated....

  9. In situ–Directed Growth of Organic Nanofibers and Nanoflakes: Electrical and Morphological Properties

    Directory of Open Access Journals (Sweden)

    de Oliveira Hansen Roana

    2011-01-01

    Full Text Available Abstract Organic nanostructures made from organic molecules such as para-hexaphenylene (p-6P could form nanoscale components in future electronic and optoelectronic devices. However, the integration of such fragile nanostructures with the necessary interface circuitry such as metal electrodes for electrical connection continues to be a significant hindrance toward their large-scale implementation. Here, we demonstrate in situ–directed growth of such organic nanostructures between pre-fabricated contacts, which are source–drain gold electrodes on a transistor platform (bottom-gate on silicon dioxide patterned by a combination of optical lithography and electron beam lithography. The dimensions of the gold electrodes strongly influence the morphology of the resulting structures leading to notably different electrical properties. The ability to control such nanofiber or nanoflake growth opens the possibility for large-scale optoelectronic device fabrication.

  10. Microbial fuel cells for direct electrical energy recovery from urban wastewaters.

    Science.gov (United States)

    Capodaglio, A G; Molognoni, D; Dallago, E; Liberale, A; Cella, R; Longoni, P; Pantaleoni, L

    2013-01-01

    Application of microbial fuel cells (MFCs) to wastewater treatment for direct recovery of electric energy appears to provide a potentially attractive alternative to traditional treatment processes, in an optic of costs reduction, and tapping of sustainable energy sources that characterizes current trends in technology. This work focuses on a laboratory-scale, air-cathode, and single-chamber MFC, with internal volume of 6.9 L, operating in batch mode. The MFC was fed with different types of substrates. This study evaluates the MFC behaviour, in terms of organic matter removal efficiency, which reached 86% (on average) with a hydraulic retention time of 150 hours. The MFC produced an average power density of 13.2 mW/m(3), with a Coulombic efficiency ranging from 0.8 to 1.9%. The amount of data collected allowed an accurate analysis of the repeatability of MFC electrochemical behaviour, with regards to both COD removal kinetics and electric energy production.

  11. Three-dimensional direct laser written graphitic electrical contacts to randomly distributed components

    Science.gov (United States)

    Dorin, Bryce; Parkinson, Patrick; Scully, Patricia

    2018-04-01

    The development of cost-effective electrical packaging for randomly distributed micro/nano-scale devices is a widely recognized challenge for fabrication technologies. Three-dimensional direct laser writing (DLW) has been proposed as a solution to this challenge, and has enabled the creation of rapid and low resistance graphitic wires within commercial polyimide substrates. In this work, we utilize the DLW technique to electrically contact three fully encapsulated and randomly positioned light-emitting diodes (LEDs) in a one-step process. The resolution of the contacts is in the order of 20 μ m, with an average circuit resistance of 29 ± 18 kΩ per LED contacted. The speed and simplicity of this technique is promising to meet the needs of future microelectronics and device packaging.

  12. Theory of field induced incommensurability: CsFeCl3

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker

    1986-01-01

    Using correlation theory for the singlet-doublet magnet CsFeCl3 in a magnetic field, a field induced incommensurate ordering along K-M is predicted without invoking dipolar effects. A fully self-consistent RPA theory gives Hc=44 kG in agreement with experiments at T=1.3K. Correlation and dipolar...

  13. Simulation of LOF accidents with directly electrical heated UO2 pins

    International Nuclear Information System (INIS)

    Alexas, A.

    1976-01-01

    The behavior of directly electrical heated UO 2 pins has been investigated under loss of coolant conditions. Two types of hypothetical accidents have been simulated, first, a LOF accident without power excursion (LOF accident) and second, a LOF accident with subsequent power excursion (LOF-TOP accident). A high-speed film shows the sequence of events for two characteristic experiments. In consequence of the high-speed film analysis as well as the metallographical evaluation statements are given in respect to the cladding meltdown process, the fuel melt fraction and the energy input from the beginning of a power transient to the beginning of the molten fuel ejections

  14. Electrical Thermal Network for Direct Contact Membrane Distillation Modeling and Analysis

    KAUST Repository

    Karam, Ayman M.

    2015-02-04

    Membrane distillation is an emerging water distillation technology that offers several advantages compared to conventional water desalination processes. Although progress has been made to model and understand the physics of the process, many studies are based on steady-state assumptions or are computationally not appropriate for real time control. This paper presents the derivation of a novel dynamical model, based on analogy between electrical and thermal systems, for direct contact membrane distillation (DCMD). The proposed model captures the dynamics of temperature distribution and distilled water flux. To demonstrate the adequacy of the proposed model, validation with transient and steady-state experimental data is presented.

  15. An energy management system for a directly-driven electric scooter

    International Nuclear Information System (INIS)

    Yang, Yee-Pien; Liu, Jieng-Jang; Hu, Tsung-Hsien

    2011-01-01

    An energy management system with an electronic gearshift and regenerative braking is presented to improve the gross efficiency and driving range of an electric scooter, driven directly by a four-phase axial-flux DC brushless wheel motor. The integration of stator windings, batteries, ultracapacitors, and a digital controller constitutes an energy management system, which features smooth electronic gear shifting and regenerative braking. The gross efficiency of the experimental scooter is improved in the drivable range by 20% with respect to that without regenerative braking. The battery-to-wheel efficiency was also above 70% for both low- and high-speed gears.

  16. Review of direct electrical heating experiments on irradiated mixed-oxide fuel

    International Nuclear Information System (INIS)

    Fenske, G.R.; Bandyopadhyay, G.

    1982-01-01

    Results of approximately 50 out-of-reactor experiments that simulated various stages of a loss-of-flow event with irradiated fuel are presented. The tests, which utilized the direct electrical heating technique to simulate nuclear heating, were performed either on fuel segments with their original cladding intact or on fuel segments that were extruded into quartz tubes. The test results demonstrated that the macro- and microscopic fuel behavior was dependent on a number of variables including fuel heating rate, thermal history prior to a transient, the number of heating cycles, type of cladding (quartz vs stainless steel), and fuel burnup

  17. An energy management system for a directly-driven electric scooter

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yee-Pien, E-mail: ypyang@ntu.edu.t [Department of Mechanical Engineering, National Taiwan University, No. 1, Roosevelt Road, Section 4, Taipei, Taiwan (China); Liu, Jieng-Jang, E-mail: jjliu@ntu.edu.t [Department of Mechanical Engineering, National Taiwan University, No. 1, Roosevelt Road, Section 4, Taipei, Taiwan (China); Hu, Tsung-Hsien, E-mail: elvishu@artc.org.t [Department of Mechanical Engineering, National Taiwan University, No. 1, Roosevelt Road, Section 4, Taipei, Taiwan (China)

    2011-01-15

    An energy management system with an electronic gearshift and regenerative braking is presented to improve the gross efficiency and driving range of an electric scooter, driven directly by a four-phase axial-flux DC brushless wheel motor. The integration of stator windings, batteries, ultracapacitors, and a digital controller constitutes an energy management system, which features smooth electronic gear shifting and regenerative braking. The gross efficiency of the experimental scooter is improved in the drivable range by 20% with respect to that without regenerative braking. The battery-to-wheel efficiency was also above 70% for both low- and high-speed gears.

  18. An energy management system for a directly-driven electric scooter

    Energy Technology Data Exchange (ETDEWEB)

    Yee-Pien Yang; Jieng-Jang Liu; Tsung-Hsien Hu [Department of Mechanical Engineering, National Taiwan University, No. 1, Roosevelt Road, Section 4, Taipei (China)

    2011-01-15

    An energy management system with an electronic gearshift and regenerative braking is presented to improve the gross efficiency and driving range of an electric scooter, driven directly by a four-phase axial-flux DC brushless wheel motor. The integration of stator windings, batteries, ultracapacitors, and a digital controller constitutes an energy management system, which features smooth electronic gear shifting and regenerative braking. The gross efficiency of the experimental scooter is improved in the drivable range by 20% with respect to that without regenerative braking. The battery-to-wheel efficiency was also above 70% for both low- and high-speed gears. (author)

  19. Atomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithm

    CERN Document Server

    Djurabekova, Flyura; Pohjonen, Aarne; Nordlund, Kai

    2011-01-01

    The effect of electric fields on metal surfaces is fairly well studied, resulting in numerous analytical models developed to understand the mechanisms of ionization of surface atoms observed at very high electric fields, as well as the general behavior of a metal surface in this condition. However, the derivation of analytical models does not include explicitly the structural properties of metals, missing the link between the instantaneous effects owing to the applied field and the consequent response observed in the metal surface as a result of an extended application of an electric field. In the present work, we have developed a concurrent electrodynamic–molecular dynamic model for the dynamical simulation of an electric-field effect and subsequent modification of a metal surface in the framework of an atomistic molecular dynamics (MD) approach. The partial charge induced on the surface atoms by the electric field is assessed by applying the classical Gauss law. The electric forces acting on the partially...

  20. Cytotoxicity, Bactericidal, and Antioxidant Activity of Sodium Alginate Hydrosols Treated with Direct Electric Current

    Directory of Open Access Journals (Sweden)

    Żaneta Król

    2017-03-01

    Full Text Available The aim of the study was to investigate the effect of using direct electric current (DC of 0, 200, and 400 mA for five minutes on the physiochemical properties, cytotoxicity, antibacterial, and antioxidant activity of sodium alginate hydrosols with different sodium chloride concentrations. The pH, oxidation-reduction potential (ORP, electrical conductivity (EC, and available chlorine concentration (ACC were measured. The effect of sodium alginate hydrosols treated with DC on Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Micrococcus luteus, Escherichia coli, Salmonella enteritidis, Yersinia enterocolitica, Pseudomonas fluorescence, and RAW 264.7 and L929 cells was investigated. Subsequently, the antioxidant properties of hydrosols were evaluated by determining the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH and ferric reducing antioxidant power (FRAP. The results have shown that after applying 400 mA in hydrosol samples with 0.1% and 0.2% NaCl all tested bacteria were inactivated. The ACC concentration of C400 samples with NaCl was equal to 13.95 and 19.71 mg/L, respectively. The cytotoxicity analysis revealed that optimized electric field conditions and the addition of sodium chloride allow for the avoidance of toxicity effects on normal cells without disturbing the antibacterial effects. Due to the presence of oxidizing substances, the DPPH of variants treated with DC was lower than the DPPH of control samples.

  1. Optical gain in colloidal quantum dots achieved with direct-current electrical pumping

    Science.gov (United States)

    Lim, Jaehoon; Park, Young-Shin; Klimov, Victor I.

    2018-01-01

    Chemically synthesized semiconductor quantum dots (QDs) can potentially enable solution-processable laser diodes with a wide range of operational wavelengths, yet demonstrations of lasing from the QDs are still at the laboratory stage. An important challenge--realization of lasing with electrical injection--remains unresolved, largely due to fast nonradiative Auger recombination of multicarrier states that represent gain-active species in the QDs. Here we present population inversion and optical gain in colloidal nanocrystals realized with direct-current electrical pumping. Using continuously graded QDs, we achieve a considerable suppression of Auger decay such that it can be outpaced by electrical injection. Further, we apply a special current-focusing device architecture, which allows us to produce high current densities (j) up to ~18 A cm-2 without damaging either the QDs or the injection layers. The quantitative analysis of electroluminescence and current-modulated transmission spectra indicates that with j = 3-4 A cm-2 we achieve the population inversion of the band-edge states.

  2. Directional Congestion and Regime Switching in a Long Memory Model for Electricity Prices

    DEFF Research Database (Denmark)

    Haldrup, Niels; Nielsen, Morten Ø.

    The functioning of electricity markets has experienced increasing complexityas a result of deregulation in recent years. Consequently this affects the multilateral price behaviour across regions with physical exchange of power. It has been documented elsewhere that features such aslong memory...... and regime switching reflecting congestion and non-congestion periods are empirically relevant and hence are features that need to be taken into account when modeling price behavior. In the present paper we further elaborate on the co-existence of long memory and regime switches by focusing on the effect...... that the direction of possible congestion episodes has on the price dynamics. Under non-congestion prices are identical. The direction of possible congestion is identified by the region with excess demand of power through the sign of price differences and hence three different states can be considered: Non...

  3. Mode of the short circuit in the direct current electric traction network with different feed charts of fyder area

    Directory of Open Access Journals (Sweden)

    P. Mihalichenko

    2012-12-01

    Full Text Available In the article the results of mathematical design of the system of electric traction of direct current are represented in the mode of short circuit and different feed charts of fyder area: two-sided; one-sided. Comparison of transitional electric sizes which characterize electromagnetic processes during these malfunctions is analysed and executed.

  4. Electrical equivalent thermal network for direct contact membrane distillation modeling and analysis

    KAUST Repository

    Karam, Ayman M.

    2016-09-19

    Membrane distillation (MD) is an emerging water desalination technology that offers several advantages compared to conventional desalination methods. Although progress has been made to model the physics of the process, there are two common limitations of existing models. Firstly, many of the models are based on the steady-state analysis of the process and secondly, some of the models are based on partial differential equations, which when discretized introduce many states which are not accessible in practice. This paper presents the derivation of a novel dynamic model, based on the analogy between electrical and thermal systems, for direct contact membrane distillation (DCMD). An analogous electrical thermal network is constructed and its elements are parameterized such that the response of the network models the DCMD process. The proposed model captures the spatial and temporal responses of the temperature distribution along the flow direction and is able to accurately predict the distilled water flux output. To demonstrate the adequacy of the proposed model, validation with time varying and steady-state experimental data is presented. (C) 2016 Elsevier Ltd. All rights reserved.

  5. Direct localised measurement of electrical resistivity profile in rat and embryonic chick retinas using a microprobe

    Directory of Open Access Journals (Sweden)

    Harald van Lintel

    2010-01-01

    Full Text Available We report an alternative technique to perform a direct and local measurement of electrical resistivities in a layered retinal tissue. Information on resistivity changes along the depth in a retina is important for modelling retinal stimulation by retinal prostheses. Existing techniques for resistivity-depth profiling have the drawbacks of a complicated experimental setup, a less localised resistivity probing and/or lower stability for measurements. We employed a flexible microprobe to measure local resistivity with bipolar impedance spectroscopy at various depths in isolated rat and chick embryo retinas for the first time. Small electrode spacing permitted high resolution measurements and the probe flexibility contributed to stable resistivity profiling. The resistivity was directly calculated based on the resistive part of the impedance measured with the Peak Resistance Frequency (PRF methodology. The resistivity-depth profiles for both rat and chick embryo models are in accordance with previous mammalian and avian studies in literature. We demonstrate that the measured resistivity at each depth has its own PRF signature. Resistivity profiles obtained with our setup provide the basis for the construction of an electric model of the retina. This model can be used to predict variations in parameters related to retinal stimulation and especially in the design and optimisation of efficient retinal implants.

  6. Direct prediction of spatially and temporally varying physical properties from time-lapse electrical resistance data

    Science.gov (United States)

    Hermans, Thomas; Oware, Erasmus; Caers, Jef

    2016-09-01

    Time-lapse applications of electrical methods have grown significantly over the last decade. However, the quantitative interpretation of tomograms in terms of physical properties, such as salinity, temperature or saturation, remains difficult. In many applications, geophysical models are transformed into hydrological models, but this transformation suffers from spatially and temporally varying resolution resulting from the regularization used by the deterministic inversion. In this study, we investigate a prediction-focused approach (PFA) to directly estimate subsurface physical properties with electrical resistance data, circumventing the need for classic tomographic inversions. First, we generate a prior set of resistance data and physical property forecast through hydrogeological and geophysical simulations mimicking the field experiment. We reduce the dimension of both the data and the forecast through principal component analysis in order to keep the most informative part of both sets in a reduced dimension space. Then, we apply canonical correlation analysis to explore the relationship between the data and the forecast in their reduced dimension space. If a linear relationship can be established, the posterior distribution of the forecast can be directly sampled using a Gaussian process regression where the field data scores are the conditioning data. In this paper, we demonstrate PFA for various physical property distributions. We also develop a framework to propagate the estimated noise level in the reduced dimension space. We validate the results by a Monte Carlo study on the posterior distribution and demonstrate that PFA yields accurate uncertainty for the cases studied.

  7. Investigation of students’ intermediate conceptual understanding levels: the case of direct current electricity concepts

    International Nuclear Information System (INIS)

    Aktan, D Cobanoglu

    2013-01-01

    Conceptual understanding is one of the main topics in science and physics education research. In the majority of conceptual understanding studies, students’ understanding levels were categorized dichotomously, either as alternative or scientific understanding. Although they are invaluable in many ways, namely developing new instructional materials and assessment instruments, students’ alternative understandings alone are not sufficient to describe students’ conceptual understanding in detail. This paper introduces an example of a study in which a method was developed to assess and describe students’ conceptual understanding beyond alternative and scientific understanding levels. In this study, six undergraduate students’ conceptual understanding levels of direct current electricity concepts were assessed and described in detail by using their answers to qualitative problems. In order to do this, conceptual understanding indicators are described based on science and mathematics education literature. The students’ understanding levels were analysed by assertion analysis based on the conceptual understanding indicators. The results indicated that the participants demonstrated three intermediate understanding levels in addition to alternative and scientific understanding. This paper presents the method and its application to direct current electricity concepts. (paper)

  8. Enhanced Working Memory Binding by Direct Electrical Stimulation of the Parietal Cortex

    Directory of Open Access Journals (Sweden)

    Agustina Birba

    2017-06-01

    Full Text Available Recent works evince the critical role of visual short-term memory (STM binding deficits as a clinical and preclinical marker of Alzheimer’s disease (AD. These studies suggest a potential role of posterior brain regions in both the neurocognitive deficits of Alzheimer’s patients and STM binding in general. Thereupon, we surmised that stimulation of the posterior parietal cortex (PPC might be a successful approach to tackle working memory deficits in this condition, especially at early stages. To date, no causal evidence exists of the role of the parietal cortex in STM binding. A unique approach to assess this issue is afforded by single-subject direct intracranial electrical stimulation of specific brain regions during a relevant cognitive task. Electrical stimulation has been used both for clinical purposes and to causally probe brain mechanisms. Previous evidence of electrical currents spreading through white matter along well defined functional circuits indicates that visual working memory mechanisms are subserved by a specific widely distributed network. Here, we stimulated the parietal cortex of a subject with intracranial electrodes as he performed the visual STM task. We compared the ensuing results to those from a non-stimulated condition and to the performance of a matched control group. In brief, direct stimulation of the parietal cortex induced a selective improvement in STM. These results, together with previous studies, provide very preliminary but promising ground to examine behavioral changes upon parietal stimulation in AD. We discuss our results regarding: (a the usefulness of the task to target prodromal stages of AD; (b the role of a posterior network in STM binding and in AD; and (c the potential opportunity to improve STM binding through brain stimulation.

  9. Direct marketing of electricity from biogas plants; Direktvermarktung von Strom aus Biogasanlagen. Chancen und Risiken aus rechtlicher Sicht

    Energy Technology Data Exchange (ETDEWEB)

    Falke, Iris; Schlichting, Julia [Schnutenhaus und Kollegen, Rechtsanwaelte, Berlin (Germany)

    2013-10-01

    The German Renewable Energy Sources Act of January, 1{sup st} 2012 contains new possibilities of direct selling electricity to the market, to promote and to improve market integration of electricity generated from renewable energies. The core is the introduction of a market premium for electricity which has actually been fed into the grid system and purchased by a third party. In addition to his market revenues, the installation operator receives the market premium. The market premium replaces the guaranteed EEG feed-in tariff. The market premium should cover the difference between the proceeds from direct selling and the EEG feed-in tariff. In addition, installation operators receive a management premium to compensate their transaction costs. As a supplement to the market premium model the EEG 2012 introduces a flexibility premium to create an economic incentive for providing additional capacities and encourage a demand-oriented electricity production. Further possibilities of direct marketing are the ''green electricity privilege'' and the non-subsided direct marketing. This article provides an over-view of the different forms of direct-marketing that are included in EEG 2012 with a focus on the market premium and the flexibility premium. These two instruments are of high importance to operators of installations generating electricity from biogas. A further emphasis is put on risks and chances in contract negotiation in the context of direct marketing. (orig.)

  10. Theoretical evaluation of maximum electric field approximation of direct band-to-band tunneling Kane model for low bandgap semiconductors

    Science.gov (United States)

    Dang Chien, Nguyen; Shih, Chun-Hsing; Hoa, Phu Chi; Minh, Nguyen Hong; Thi Thanh Hien, Duong; Nhung, Le Hong

    2016-06-01

    The two-band Kane model has been popularly used to calculate the band-to-band tunneling (BTBT) current in tunnel field-effect transistor (TFET) which is currently considered as a promising candidate for low power applications. This study theoretically clarifies the maximum electric field approximation (MEFA) of direct BTBT Kane model and evaluates its appropriateness for low bandgap semiconductors. By analysing the physical origin of each electric field term in the Kane model, it has been elucidated in the MEFA that the local electric field term must be remained while the nonlocal electric field terms are assigned by the maximum value of electric field at the tunnel junction. Mathematical investigations have showed that the MEFA is more appropriate for low bandgap semiconductors compared to high bandgap materials because of enhanced tunneling probability in low field regions. The appropriateness of the MEFA is very useful for practical uses in quickly estimating the direct BTBT current in low bandgap TFET devices.

  11. Magnetic field induced suppression of the forward bias current in Bi2Se3/Si Schottky barrier diodes

    Science.gov (United States)

    Jin, Haoming; Hebard, Arthur

    Schottky diodes formed by van der Waals bonding between freshly cleaved flakes of the topological insulator Bi2Se3 and doped silicon substrates show electrical characteristics in good agreement with thermionic emission theory. The motivation is to use magnetic fields to modulate the conductance of the topologically protected conducting surface state. This surface state in close proximity to the semiconductor surface may play an important role in determining the nature of the Schottky barrier. Current-voltage (I-V) and capacitance-voltage (C-V) characteristics were obtained for temperatures in the range 50-300 K and magnetic fields, both perpendicular and parallel to the interface, as high as 7 T. The I-V curve shows more than 6 decades linearity on semi-logarithmic plots, allowing extraction of parameters such as ideality (η), zero-voltage Schottky barrier height (SBH), and series resistance (Rs). In forward bias we observe a field-induced decrease in current which becomes increasingly more pronounced at higher voltages and lower temperature, and is found to be correlated with changes in Rs rather than other barrier parameters. A comparison of changes in Rs in both field direction will be made with magnetoresistance in Bi2Se3 transport measurement. The work is supported by NSF through DMR 1305783.

  12. Janus particle microshuttle: 1D directional self-propulsion modulated by AC electrical field

    Directory of Open Access Journals (Sweden)

    Jiliang Chen

    2014-03-01

    Full Text Available A catalytic Janus particle is capable of gaining energy from the surrounding fuel solution to drive itself to move continuously, which has an important impact in different fields, especially the field of micro-systems. However, the randomness of self-propulsion at the microscale restricts its use in practice. Achieving a directed self-propelled movement would greatly promote the application of the Janus particle. We proved experimentally that an AC electric field was an effective way to suppress Brownian motion and control the direction of self-propelled movement. The self-propulsion and dielectrophoretic response of a 2μm Janus particle were observed and the related basic data were collected. Interdigital electrodes, 20 μm in width, were energized in pulsed style to modulate the self-propulsion, which resulted in a shuttle-style motion in which a single Janus particle moved to and fro inside the strip electrode. The change of direction depends on its unique position: the catalyst side is always pointed outward and the orientation angle relative to the electrode is about 60°. Numerical simulation also proved that this position is reasonable. The present study could be beneficial with regard to self-propulsion and AC electrokinetics of the Janus particle.

  13. Powering microbes with electricity: direct electron transfer from electrodes to microbes.

    Science.gov (United States)

    Lovley, Derek R

    2011-02-01

    The discovery of electrotrophs, microorganisms that can directly accept electrons from electrodes for the reduction of terminal electron acceptors, has spurred the investigation of a wide range of potential applications. To date, only a handful of pure cultures have been shown to be capable of electrotrophy, but this process has also been inferred in many studies with undefined consortia. Potential electron acceptors include: carbon dioxide, nitrate, metals, chlorinated compounds, organic acids, protons and oxygen. Direct electron transfer from electrodes to cells has many advantages over indirect electrical stimulation of microbial metabolism via electron shuttles or hydrogen production. Supplying electrons with electrodes for the bioremediation of chlorinated compounds, nitrate or toxic metals may be preferable to adding organic electron donors or hydrogen to the subsurface or bioreactors. The most transformative application of electrotrophy may be microbial electrosynthesis in which carbon dioxide and water are converted to multi-carbon organic compounds that are released extracellularly. Coupling photovoltaic technology with microbial electrosynthesis represents a novel photosynthesis strategy that avoids many of the drawbacks of biomass-based strategies for the production of transportation fuels and other organic chemicals. The mechanisms for direct electron transfer from electrodes to microorganisms warrant further investigation in order to optimize envisioned applications. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  14. Electricity generation by direct oxidation of glucose in mediatorless microbial fuel cells.

    Science.gov (United States)

    Chaudhuri, Swades K; Lovley, Derek R

    2003-10-01

    Abundant energy, stored primarily in the form of carbohydrates, can be found in waste biomass from agricultural, municipal and industrial sources as well as in dedicated energy crops, such as corn and other grains. Potential strategies for deriving useful forms of energy from carbohydrates include production of ethanol and conversion to hydrogen, but these approaches face technical and economic hurdles. An alternative strategy is direct conversion of sugars to electrical power. Existing transition metal-catalyzed fuel cells cannot be used to generate electric power from carbohydrates. Alternatively, biofuel cells in which whole cells or isolated redox enzymes catalyze the oxidation of the sugar have been developed, but their applicability has been limited by several factors, including (i) the need to add electron-shuttling compounds that mediate electron transfer from the cell to the anode, (ii) incomplete oxidation of the sugars and (iii) lack of long-term stability of the fuel cells. Here we report on a novel microorganism, Rhodoferax ferrireducens, that can oxidize glucose to CO(2) and quantitatively transfer electrons to graphite electrodes without the need for an electron-shuttling mediator. Growth is supported by energy derived from the electron transfer process itself and results in stable, long-term power production.

  15. Composition of plastics from waste electrical and electronic equipment (WEEE) by direct sampling

    International Nuclear Information System (INIS)

    Martinho, Graça; Pires, Ana; Saraiva, Luanha; Ribeiro, Rita

    2012-01-01

    Highlights: ► The article shows WEEE plastics characterization from a recycling unit in Portugal. ► The recycling unit has low machinery, with hand sorting of plastics elements. ► Most common polymers are PS, ABS, PC/ABS, HIPS and PP. ► Most plastics found have no identification of plastic type or flame retardants. ► Ecodesign is still not practiced for EEE, with repercussions in end of life stage. - Abstract: This paper describes a direct analysis study carried out in a recycling unit for waste electrical and electronic equipment (WEEE) in Portugal to characterize the plastic constituents of WEEE. Approximately 3400 items, including cooling appliances, small WEEE, printers, copying equipment, central processing units, cathode ray tube (CRT) monitors and CRT televisions were characterized, with the analysis finding around 6000 kg of plastics with several polymer types. The most common polymers are polystyrene, acrylonitrile–butadiene–styrene, polycarbonate blends, high-impact polystyrene and polypropylene. Additives to darken color are common contaminants in these plastics when used in CRT televisions and small WEEE. These additives can make plastic identification difficult, along with missing polymer identification and flame retardant identification marks. These drawbacks contribute to the inefficiency of manual dismantling of WEEE, which is the typical recycling process in Portugal. The information found here can be used to set a baseline for the plastics recycling industry and provide information for ecodesign in electrical and electronic equipment production.

  16. Modulation of electric brain responses evoked by pitch deviants through transcranial direct current stimulation.

    Science.gov (United States)

    Royal, Isabelle; Zendel, Benjamin Rich; Desjardins, Marie-Ève; Robitaille, Nicolas; Peretz, Isabelle

    2018-01-31

    Congenital amusia is a neurodevelopmental disorder, characterized by a difficulty detecting pitch deviation that is related to abnormal electrical brain responses. Abnormalities found along the right fronto-temporal pathway between the inferior frontal gyrus (IFG) and the auditory cortex (AC) are the likely neural mechanism responsible for amusia. To investigate the causal role of these regions during the detection of pitch deviants, we applied cathodal (inhibitory) transcranial direct current stimulation (tDCS) over right frontal and right temporal regions during separate testing sessions. We recorded participants' electrical brain activity (EEG) before and after tDCS stimulation while they performed a pitch change detection task. Relative to a sham condition, there was a decrease in P3 amplitude after cathodal stimulation over both frontal and temporal regions compared to pre-stimulation baseline. This decrease was associated with small pitch deviations (6.25 cents), but not large pitch deviations (200 cents). Overall, this demonstrates that using tDCS to disrupt regions around the IFG and AC can induce temporary changes in evoked brain activity when processing pitch deviants. These electrophysiological changes are similar to those observed in amusia and provide causal support for the connection between P3 and fronto-temporal brain regions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Composition of plastics from waste electrical and electronic equipment (WEEE) by direct sampling.

    Science.gov (United States)

    Martinho, Graça; Pires, Ana; Saraiva, Luanha; Ribeiro, Rita

    2012-06-01

    This paper describes a direct analysis study carried out in a recycling unit for waste electrical and electronic equipment (WEEE) in Portugal to characterize the plastic constituents of WEEE. Approximately 3400 items, including cooling appliances, small WEEE, printers, copying equipment, central processing units, cathode ray tube (CRT) monitors and CRT televisions were characterized, with the analysis finding around 6000 kg of plastics with several polymer types. The most common polymers are polystyrene, acrylonitrile-butadiene-styrene, polycarbonate blends, high-impact polystyrene and polypropylene. Additives to darken color are common contaminants in these plastics when used in CRT televisions and small WEEE. These additives can make plastic identification difficult, along with missing polymer identification and flame retardant identification marks. These drawbacks contribute to the inefficiency of manual dismantling of WEEE, which is the typical recycling process in Portugal. The information found here can be used to set a baseline for the plastics recycling industry and provide information for ecodesign in electrical and electronic equipment production. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Direct and indirect health and safety impacts of electrical generation options

    International Nuclear Information System (INIS)

    Habegger, L.J.; Gasper, J.R.; Brown, C.D.

    1982-01-01

    This report is an analysis of the health and safety risks of seven electrical generation systems, all of which have the potential for commercial availability after the year 2000. The systems are compared on the basis of expected public and occupational deaths and lost workdays associated with average unit generation of 1000 MW(e) per year. The risks and associated uncertainties are estimated for all phases of the energy production cycle, including fuel extraction and processing, on-site construction and system operation and maintenance. Also included are the risks of direct and indirect component manufacture, materials production and energy inputs, all of which are major contributors to the risks of the more capital-intensive solar technologies. The potential significance of major health and safety issues that remain largely unquantifiable are also considered. (author)

  19. Characterizing inner-shell with spectral phase interferometry for direct electric-field reconstruction

    Science.gov (United States)

    Mashiko, Hiroki; Yamaguchi, Tomohiko; Oguri, Katsuya; Suda, Akira; Gotoh, Hideki

    2014-01-01

    In many atomic, molecular and solid systems, Lorentzian and Fano profiles are commonly observed in a broad research fields throughout a variety of spectroscopies. As the profile structure is related to the phase of the time-dependent dipole moment, it plays an important role in the study of quantum properties. Here we determine the dipole phase in the inner-shell transition using spectral phase interferometry for direct electric-field reconstruction (SPIDER) with isolated attosecond pulses (IAPs). In addition, we propose a scheme for pulse generation and compression by manipulating the inner-shell transition. The electromagnetic radiation generated by the transition is temporally compressed to a few femtoseconds in the extreme ultraviolet (XUV) region. The proposed pulse-compression scheme may provide an alternative route to producing attosecond pulses of light. PMID:25510971

  20. Evidence for a Field-induced Quantum Spin Liquid in $\\alpha$-RuCl$_3$

    OpenAIRE

    Baek, S. -H.; Do, S. -H.; Choi, K. -Y.; Kwon, Y. S.; Wolter, A. U. B.; Nishimoto, S.; Brink, Jeroen van den; Büchner, B.

    2017-01-01

    We report a $^{35}$Cl nuclear magnetic resonance study in the honeycomb lattice, $\\alpha$-RuCl$_3$, a material that has been suggested to potentially realize a Kitaev quantum spin liquid (QSL) ground state. Our results provide direct evidence that $\\alpha$-RuCl$_3$ exhibits a magnetic field-induced QSL. For fields larger than $\\sim 10$ T a spin-gap opens up while resonance lines remain sharp, evidencing that spins are quantum disordered and locally fluctuating. The spin gap increases linearly...

  1. Electrical stimulation directs engineered cardiac tissue to an age-matched native phenotype

    Directory of Open Access Journals (Sweden)

    Richard A Lasher

    2012-12-01

    Full Text Available Quantifying structural features of native myocardium in engineered tissue is essential for creating functional tissue that can serve as a surrogate for in vitro testing or the eventual replacement of diseased or injured myocardium. We applied three-dimensional confocal imaging and image analysis to quantitatively describe the features of native and engineered cardiac tissue. Quantitative analysis methods were developed and applied to test the hypothesis that environmental cues direct engineered tissue toward a phenotype resembling that of age-matched native myocardium. The analytical approach was applied to engineered cardiac tissue with and without the application of electrical stimulation as well as to age-matched and adult native tissue. Individual myocytes were segmented from confocal image stacks and assigned a coordinate system from which measures of cell geometry and connexin-43 spatial distribution were calculated. The data were collected from 9 nonstimulated and 12 electrically stimulated engineered tissue constructs and 5 postnatal day 12 and 7 adult hearts. The myocyte volume fraction was nearly double in stimulated engineered tissue compared to nonstimulated engineered tissue (0.34 ± 0.14 vs 0.18 ± 0.06 but less than half of the native postnatal day 12 (0.90 ± 0.06 and adult (0.91 ± 0.04 myocardium. The myocytes under electrical stimulation were more elongated compared to nonstimulated myocytes and exhibited similar lengths, widths, and heights as in age-matched myocardium. Furthermore, the percentage of connexin-43-positive membrane staining was similar in the electrically stimulated, postnatal day 12, and adult myocytes, whereas it was significantly lower in the nonstimulated myocytes. Connexin-43 was found to be primarily located at cell ends for adult myocytes and irregularly but densely clustered over the membranes of nonstimulated, stimulated, and postnatal day 12 myocytes. These findings support our hypothesis and reveal

  2. The direct conversion of heat into electricity in reactors; Conversion directe de la chaleur en electricite dans les piles

    Energy Technology Data Exchange (ETDEWEB)

    Devin, B; Bliaux, J; Lesueur, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The direct conversion of heat into electricity by thermionic emission in an atomic reactor has been studied with the triple aim of its utilisation: as an energy source for a space device, at the head of a conventional conversion system in power installations, or finally in association with the thermoelectric conversion in very low power installations. The laboratory experiments were mainly orientated towards the electron extraction of metals and compounds and their behaviour at high temperatures. Converters furnishing up to 50 amps at 0. 4 volts with an efficiency close to 10 p. 100 have been constructed in the laboratory; the emitters were heated by electron bombardment and were composed of tungsten covered with an uranium carbide deposit or molybdenum covered with cesium. The main aspects of the coupling between the converter and the reactor have been covered from the point of view of electronics: the influence of the mismatching of the load on the temperature of the emitter and the influence of thermal flux density on the temperature of the emitter and the stability of the converter. Converters using uranium carbide as the electron emitter have been tested in reactors. Tests have been made under dynamic conditions in order to determine the dynamic characteristics. The load matching curves have been constructed and the overall performances of several cells coupled in such a way as to form a reactor rod have been deduced. This information is fundamental to the design of a control system for a thermionic conversion reactor. The problems associated with the reliability of thermionic converters connected in series in the same reactor rod have been examined theoretically. Finally, the absorption isotherms have been drawn at the ambient temperatures for krypton and xenon on activated carbon with the aim of investigating the escape of fission products in a converter. (author) [French] La conversion directe de chaleur en electricite par emission thermionique dans une

  3. Enhanced electrocatalytic CO2 reduction via field-induced reagent concentration

    Science.gov (United States)

    Liu, Min; Pang, Yuanjie; Zhang, Bo; de Luna, Phil; Voznyy, Oleksandr; Xu, Jixian; Zheng, Xueli; Dinh, Cao Thang; Fan, Fengjia; Cao, Changhong; de Arquer, F. Pelayo García; Safaei, Tina Saberi; Mepham, Adam; Klinkova, Anna; Kumacheva, Eugenia; Filleter, Tobin; Sinton, David; Kelley, Shana O.; Sargent, Edward H.

    2016-09-01

    Electrochemical reduction of carbon dioxide (CO2) to carbon monoxide (CO) is the first step in the synthesis of more complex carbon-based fuels and feedstocks using renewable electricity. Unfortunately, the reaction suffers from slow kinetics owing to the low local concentration of CO2 surrounding typical CO2 reduction reaction catalysts. Alkali metal cations are known to overcome this limitation through non-covalent interactions with adsorbed reagent species, but the effect is restricted by the solubility of relevant salts. Large applied electrode potentials can also enhance CO2 adsorption, but this comes at the cost of increased hydrogen (H2) evolution. Here we report that nanostructured electrodes produce, at low applied overpotentials, local high electric fields that concentrate electrolyte cations, which in turn leads to a high local concentration of CO2 close to the active CO2 reduction reaction surface. Simulations reveal tenfold higher electric fields associated with metallic nanometre-sized tips compared to quasi-planar electrode regions, and measurements using gold nanoneedles confirm a field-induced reagent concentration that enables the CO2 reduction reaction to proceed with a geometric current density for CO of 22 milliamperes per square centimetre at -0.35 volts (overpotential of 0.24 volts). This performance surpasses by an order of magnitude the performance of the best gold nanorods, nanoparticles and oxide-derived noble metal catalysts. Similarly designed palladium nanoneedle electrocatalysts produce formate with a Faradaic efficiency of more than 90 per cent and an unprecedented geometric current density for formate of 10 milliamperes per square centimetre at -0.2 volts, demonstrating the wider applicability of the field-induced reagent concentration concept.

  4. Direct Electrical Detection of Iodine Gas by a Novel Metal-Organic-Framework-Based Sensor.

    Science.gov (United States)

    Small, Leo J; Nenoff, Tina M

    2017-12-27

    High-fidelity detection of iodine species is of utmost importance to the safety of the population in cases of nuclear accidents or advanced nuclear fuel reprocessing. Herein, we describe the success at using impedance spectroscopy to directly detect the real-time adsorption of I 2 by a metal-organic framework zeolitic imidazolate framework (ZIF)-8-based sensor. Methanolic suspensions of ZIF-8 were dropcast onto platinum interdigitated electrodes, dried, and exposed to gaseous I 2 at 25, 40, or 70 °C. Using an unoptimized sensor geometry, I 2 was readily detected at 25 °C in air within 720 s of exposure. The specific response is attributed to the chemical selectivity of the ZIF-8 toward I 2 . Furthermore, equivalent circuit modeling of the impedance data indicates a >10 5 × decrease in ZIF-8 resistance when 116 wt % I 2 is adsorbed by ZIF-8 at 70 °C in air. This irreversible decrease in resistance is accompanied by an irreversible loss in the long-range crystallinity, as evidenced by X-ray diffraction and infrared spectroscopy. Air, argon, methanol, and water were found to produce minimal changes in ZIF-8 impedance. This report demonstrates how selective I 2 adsorption by ZIF-8 can be leveraged to create a highly selective sensor using >10 5 × changes in impedance response to enable the direct electrical detection of environmentally relevant gaseous toxins.

  5. Electricity savings in Latvia through implementation of labelling directives. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-01-01

    Legislation on labelling of household appliances was enforced in Latvia July 2001 to implement the European labelling directives. The project 'Electricity Savings in Latvia through Implementation of labelling Directives' was started January 2001 in order to support the implementation of the directives to ensure that they got an immediate effect. The project has included the following activities: Information of the general public and of traders and importers. In relation to the general public the activities consisted of production of a widely spread information brochure, TV-spots and a TV competition and participation in a school project. Seminars and meetings with traders and importers were held to inform about the legislation before it was enforced and to create a network for discussion of practical implementation problems and planning of the information activities. Test and control activities. The purpose of the test and control activities was to strengthen the test and control capacities and to transfer experience from Denmark. This was achieved though workshops for as well inspectors from the Consumer Rights Protection Centre and for members of the voluntary Consumer Protection Clubs. Results: It is assumed that the project has been very successful in the sense that the information about labelling of appliances has been efficiently spread via the information brochure, which was printed in 100.000 copies and distributed in shops, via Latvenergo and the consumer clubs. Furthermore, a cartoon about 'Energy-eaters' produced as part of the project by a very talented Latvian film study (Environmental Film Studio) has been used as TV-spot and has been broadcasted 40 times, including in connection to a morning TV-competition on labelling of appliances. The participatory approach used in the project has resulted in a very dedicated participation from the different stake holders side. Thus there is basis for sustainability in the sense, that a network

  6. Novel Direct Steelmaking by Combining Microwave, Electric Arc, and Exothermal Heating Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Xiaodi Huang; Dr. J. Y. Hwang

    2005-03-28

    Steel is a basic material broadly used by perhaps every industry and individual. It is critical to our nation's economy and national security. Unfortunately, the American steel industry is losing competitiveness in the world steel production field. There is an urgent need to develop the next generation of steelmaking technology for the American steel industry. Direct steelmaking through the combination of microwave, electric arc, and exothermal heating is a revolutionary change from current steelmaking technology. This technology can produce molten steel directly from a shippable agglomerate, consisting of iron oxide fines, powdered coal, and ground limestone. This technology is projected to eliminate many current intermediate steelmaking steps including coking, pellet sintering, blast furnace (BF) ironmaking, and basic oxygen furnace (BOF) steelmaking. This technology has the potential to (a) save up to 45% of the energy consumed by conventional steelmaking; (b) dramatically reduce the emission of CO{sub 2}, SO{sub 2}, NO{sub x}, VOCs, fine particulates, and air toxics; (c) substantially reduce waste and emission control costs; (d) greatly lower capital cost; and (e) considerably reduce steel production costs. This technology is based on the unique capability of microwaves to rapidly heat steelmaking raw materials to elevated temperature, then rapidly reduce iron oxides to metal by volumetric heating. Microwave heating, augmented with electric arc and exothermal reactions, is capable of producing molten steel. This technology has the components necessary to establish the ''future'' domestic steel industry as a technology leader with a strong economically competitive position in world markets. The project goals were to assess the utilization of a new steelmaking technology for its potential to achieve better overall energy efficiency, minimize pollutants and wastes, lower capital and operating costs, and increase the competitiveness of the

  7. Ionization and acoustical instability of a low temperature magnetized plasma in a combined (direct and alternating) electrical field

    International Nuclear Information System (INIS)

    Andropov, V.G.; Sinkevich, O.A.

    1983-01-01

    It is shown that the ionization front which moves through a gas along a magnetic field in a combined electrical field, which lies in the plane of the front, may be unstable, as a result of the development of an ionization instability in the plasma behind the front. The criterion of instability of the ionization front does not greatly differ from the criterion of instability of an infinite plasma. The ionization front in the magnetic field is stable only in an electrical field of circular polarization or in a combined field in which the direct and alternating electrical fields are orthogonal and the Joule heat liberation from them is equal. The generation of sound is possible in a magnetized plasma in an alternating electrical field orthogonal to a magnetic due to the parametric acoustical instability at the frequency of the external electrical field. 8 refs

  8. Electrical transport in transverse direction through silicon carbon alloy multilayers containing regular size silicon quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Aparajita [Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India); Kole, Arindam, E-mail: erak@iacs.res.in [Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India); Dasgupta, Arup [Microscopy and Thermophysical Property Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Chaudhuri, Partha [Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

    2016-11-30

    Highlights: • Low temperature columnar growth of regular sized Si-quantum dots (Si-QDs) within a-SiC:H/μc-SiC:H multilayer structure by tuning the a-SiC:H layer thickness. • Thickness optimization of the a-SiC:H layers resulted in a sharp increase of the transverse current and a decrease of the trap concentrations. • The arrangements of the Si-QDs favor percolation paths for the transverse current. - Abstract: Electrical transport in the transverse direction has been studied through a series of hydrogenated silicon carbon alloy multilayers (SiC-MLs) deposited by plasma enhanced chemical vapor deposition method. Each SiC-ML consists of 30 cycles of the alternating layers of a nearly amorphous silicon carbide (a-SiC:H) and a microcrystalline silicon carbide (μc-SiC:H) that contains high density of silicon quantum dots (Si-QDs). A detailed investigation by cross sectional TEM reveals preferential growth of densely packed Si-QDs of regular sizes ∼4.8 nm in diameter in a vertically aligned columnar structure within the SiC-ML. More than six orders of magnitude increase in transverse current through the SiC-ML structure were observed for decrease in the a-SiC:H layer thickness from 13 nm to 2 nm. The electrical transport mechanism was established to be a combination of grain boundary or band tail hopping and Frenkel–Poole (F-P) type conduction depending on the temperature and externally applied voltage ranges. Evaluation of trap concentration within the multilayer structures from the fitted room temperature current voltage characteristics by F-P function shows reduction up-to two orders of magnitude indicating an improvement in the short range order in the a-SiC:H matrix for decrease in the thickness of a-SiC:H layer.

  9. Electricity

    CERN Document Server

    Basford, Leslie

    2013-01-01

    Electricity Made Simple covers the fundamental principles underlying every aspect of electricity. The book discusses current; resistance including its measurement, Kirchhoff's laws, and resistors; electroheat, electromagnetics and electrochemistry; and the motor and generator effects of electromagnetic forces. The text also describes alternating current, circuits and inductors, alternating current circuits, and a.c. generators and motors. Other methods of generating electromagnetic forces are also considered. The book is useful for electrical engineering students.

  10. Increase of energy efficiency of testing of traction electric machines of direct and pulsating current

    Directory of Open Access Journals (Sweden)

    A.M. Afanasov

    2015-03-01

    Full Text Available The results of the analysis of the effect of the load current of traction electric machines when tested for heating on the total electricity consumption for the test are presented. It is shown that increase of load current at the heating test permits to significantly reduce the consumption of electrical energy, and reduce the testing time without reducing its quality.

  11. Evidence for a Field-Induced Quantum Spin Liquid in α-RuCl_{3}.

    Science.gov (United States)

    Baek, S-H; Do, S-H; Choi, K-Y; Kwon, Y S; Wolter, A U B; Nishimoto, S; van den Brink, Jeroen; Büchner, B

    2017-07-21

    We report a ^{35}Cl nuclear magnetic resonance study in the honeycomb lattice α-RuCl_{3}, a material that has been suggested to potentially realize a Kitaev quantum spin liquid (QSL) ground state. Our results provide direct evidence that α-RuCl_{3} exhibits a magnetic-field-induced QSL. For fields larger than ∼10  T, a spin gap opens up while resonance lines remain sharp, evidencing that spins are quantum disordered and locally fluctuating. The spin gap increases linearly with an increasing magnetic field, reaching ∼50  K at 15 T, and is nearly isotropic with respect to the field direction. The unusual rapid increase of the spin gap with increasing field and its isotropic nature are incompatible with conventional magnetic ordering and, in particular, exclude that the ground state is a fully polarized ferromagnet. The presence of such a field-induced gapped QSL phase has indeed been predicted in the Kitaev model.

  12. The decolouration of methyl orange using aluminum foam, ultrasound and direct electric current

    Science.gov (United States)

    Liu, C. M.; Huang, X. Y.; Zhang, H. Y.; Dai, J. D.; Ning, C. C.

    2018-01-01

    The decolouration of methyl orange (MO) using aluminum (Al) foam, ultrasound and direct electric current (DC) is investigated. The decolouration rate (DR) of MO using only Al foam is low because there is a passivation oxide layer on the Al foam surface. Due to the low utilization of ultrasound in MO water solution medium, the DR of MO using only ultrasonic irradiation is also poor. The DR of MO is greatly increased when Al foam, ultrasonic irradiation and DC are used together. There is good synergistic effect between Al foam, ultrasound and DC in decolouration of MO. This enhancement of DR may be related to the cavitation, cleaning of Al foam surface and water electrolysis. Due to the surface charge on wire carrying stationary current, Al foam with DC acts like a serious anodes and cathodes and makes water electrolysis giving hydrogen gas to cleavage azo bond. The DC applied on Al foam is beneficial for reductive decolouration of MO. Our results show that DC is a new way for the reductive decolouration MO in water.

  13. On Possibility of Direct Asteroid Deflection by Electric Solar Wind Sail

    Science.gov (United States)

    Merikallio, Sini; Janhunen, Pekka

    2010-05-01

    The Electric Solar Wind Sail (E-sail) is a new propulsion method for interplanetary travel which was invented in 2006 and is currently under development. The E-sail uses charged tethers to extract momentum from the solar wind particles to obtain propulsive thrust. According to current estimates, the E-sail is 2-3 orders of magnitude better than traditional propulsion methods (chemical rockets and ion engines) in terms of produced lifetime-integrated impulse per propulsion system mass. Here we analyze the problem of using the E-sail for directly deflecting an Earth-threatening asteroid. The problem then culminates into how to attach the E-sail device to the asteroid. We assess a number of alternative attachment strategies and arrive at a recommendation of using the gravity tractor method because of its workability for a wide variety of asteroid types. We also consider possible techniques to scale up the E-sail force beyond the baseline one Newton level to deal with more imminent or larger asteroid or cometary threats. As a baseline case we consider a 3 million ton asteroid which can be deflected with a baseline 1 N E-sail in 5-10 years. Once developed, the E-sail would appear to provide a safe and reasonably low-cost way of deflecting dangerous asteroids and other heavenly bodies in cases where the collision threat becomes known several years in advance.

  14. Direct electrical stimulation as an input gate into brain functional networks: principles, advantages and limitations.

    Science.gov (United States)

    Mandonnet, Emmanuel; Winkler, Peter A; Duffau, Hugues

    2010-02-01

    While the fundamental and clinical contribution of direct electrical stimulation (DES) of the brain is now well acknowledged, its advantages and limitations have not been re-evaluated for a long time. Here, we critically review exactly what DES can tell us about cerebral function. First, we show that DES is highly sensitive for detecting the cortical and axonal eloquent structures. Moreover, DES also provides a unique opportunity to study brain connectivity, since each area responsive to stimulation is in fact an input gate into a large-scale network rather than an isolated discrete functional site. DES, however, also has a limitation: its specificity is suboptimal. Indeed, DES may lead to interpretations that a structure is crucial because of the induction of a transient functional response when stimulated, whereas (1) this effect is caused by the backward spreading of the electro-stimulation along the network to an essential area and/or (2) the stimulated region can be functionally compensated owing to long-term brain plasticity mechanisms. In brief, although DES is still the gold standard for brain mapping, its combination with new methods such as perioperative neurofunctional imaging and biomathematical modeling is now mandatory, in order to clearly differentiate those networks that are actually indispensable to function from those that can be compensated.

  15. Exploration of molecular pathways mediating electric field-directed Schwann cell migration by RNA-Seq

    Science.gov (United States)

    Yao, Li; Li, Yongchao; Knapp, Jennifer; Smith, Peter

    2015-01-01

    In peripheral nervous systems, Schwann cells wrap around axons of motor and sensory neurons to form the myelin sheath. Following spinal cord injury, Schwann cells regenerate and migrate to the lesion and are involved in the spinal cord regeneration process. Transplantation of Schwann cells into injured neural tissue results in enhanced spinal axonal regeneration. Effective directional migration of Schwann cells is critical in the neural regeneration process. In this study, we report that Schwann cells migrate anodally in an applied electric field (EF). The directedness and displacement of anodal migration increased significantly when the strength of the EF increased from 50 mV/mm to 200 mV/mm. The EF did not significantly affect the cell migration speed. To explore the genes and signaling pathways that regulate cell migration in EFs, we performed a comparative analysis of differential gene expression between cells stimulated with an EF (100 mV/mm) and those without using next-generation RNA sequencing, verified by RT-qPCR. Based on the cut-off criteria (FC > 1.2, q cells versus EF-stimulated cells. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis found that compared to the control group, 21 pathways are down-regulated, while 10 pathways are up-regulated. Differentially expressed genes participate in multiple cellular signaling pathways involved in the regulation of cell migration, including pathways of regulation of actin cytoskeleton, focal adhesion, and PI3K-Akt. PMID:25557037

  16. Optimization of Key Parameters of Energy Management Strategy for Hybrid Electric Vehicle Using DIRECT Algorithm

    Directory of Open Access Journals (Sweden)

    Jingxian Hao

    2016-11-01

    Full Text Available The rule-based logic threshold control strategy has been frequently used in energy management strategies for hybrid electric vehicles (HEVs owing to its convenience in adjusting parameters, real-time performance, stability, and robustness. However, the logic threshold control parameters cannot usually ensure the best vehicle performance at different driving cycles and conditions. For this reason, the optimization of key parameters is important to improve the fuel economy, dynamic performance, and drivability. In principle, this is a multiparameter nonlinear optimization problem. The logic threshold energy management strategy for an all-wheel-drive HEV is comprehensively analyzed and developed in this study. Seven key parameters to be optimized are extracted. The optimization model of key parameters is proposed from the perspective of fuel economy. The global optimization method, DIRECT algorithm, which has good real-time performance, low computational burden, rapid convergence, is selected to optimize the extracted key parameters globally. The results show that with the optimized parameters, the engine operates more at the high efficiency range resulting into a fuel savings of 7% compared with non-optimized parameters. The proposed method can provide guidance for calibrating the parameters of the vehicle energy management strategy from the perspective of fuel economy.

  17. Neural correlates of mirth and laughter: a direct electrical cortical stimulation study.

    Science.gov (United States)

    Yamao, Yukihiro; Matsumoto, Riki; Kunieda, Takeharu; Shibata, Sumiya; Shimotake, Akihiro; Kikuchi, Takayuki; Satow, Takeshi; Mikuni, Nobuhiro; Fukuyama, Hidenao; Ikeda, Akio; Miyamoto, Susumu

    2015-05-01

    Laughter consists of both motor and emotional aspects. The emotional component, known as mirth, is usually associated with the motor component, namely, bilateral facial movements. Previous electrical cortical stimulation (ES) studies revealed that mirth was associated with the basal temporal cortex, inferior frontal cortex, and medial frontal cortex. Functional neuroimaging implicated a role for the left inferior frontal and bilateral temporal cortices in humor processing. However, the neural origins and pathways linking mirth with facial movements are still unclear. We hereby report two cases with temporal lobe epilepsy undergoing subdural electrode implantation in whom ES of the left basal temporal cortex elicited both mirth and laughter-related facial muscle movements. In one case with normal hippocampus, high-frequency ES consistently caused contralateral facial movement, followed by bilateral facial movements with mirth. In contrast, in another case with hippocampal sclerosis (HS), ES elicited only mirth at low intensity and short duration, and eventually laughter at higher intensity and longer duration. In both cases, the basal temporal language area (BTLA) was located within or adjacent to the cortex where ES produced mirth. In conclusion, the present direct ES study demonstrated that 1) mirth had a close relationship with language function, 2) intact mesial temporal structures were actively engaged in the beginning of facial movements associated with mirth, and 3) these emotion-related facial movements had contralateral dominance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. The application of bonded magnet MQP-0 on an electrical direct current motor

    International Nuclear Information System (INIS)

    Ridwan; Mujamilah; Gunawan

    2002-01-01

    Isotropic bonded magnet materials using NdFeB produced by rapid quench method, has advantages that can be easily adapted to the costumer demand. The synthesized bonded magnets are mixed of cpoxy resin or polyester as matrix binder with powder magnet of MQP-O The proportions of polymer and magnetic powder are 4060; 50:50; and 6040 volume % of magnet composites. The characterization of magnetic properties was determined by Vibrating Sample Magnetometer (VSM) at P3IB-BATAN and the density was measured by piknometer. The highest energy product maximum, (BH) m ax of magnet composite synthesized by P3IB-BATAN in this activity is 435 MGOeThe quality of magnet components has been tested empirically by changing the magnetic components of an electric direct current motor found in the local market by magnetic components synthesized by P 3IB-BA TAN. The max imum rotation resulted by using P3IB-BATAN is 40 0 00 rpm The magnetic components synthesized in these research activities are functionally work and comparatively the same with the magnetic components found in the local market as an import commodities

  19. Conversion of solar energy into electricity by using duckweed in Direct Photosynthetic Plant Fuel Cell.

    Science.gov (United States)

    Hubenova, Yolina; Mitov, Mario

    2012-10-01

    In the present study we demonstrate for the first time the possibility for conversion of solar energy into electricity on the principles of Direct Photosynthetic Plant Fuel Cell (DPPFC) technology by using aquatic higher plants. Lemna minuta duckweed was grown autotrophically in specially constructed fuel cells under sunlight irradiation and laboratory lighting. Current and power density up to 1.62±0.10 A.m(-2) and 380±19 mW.m(-2), respectively, were achieved under sunlight conditions. The influence of the temperature, light intensity and day/night sequencing on the current generation was investigated. The importance of the light intensity was demonstrated by the higher values of generated current (at permanently connected resistance) during daytime than those through the nights, indicating the participation of light-dependent photosynthetic processes. The obtained DPPFC outputs in the night show the contribution of light-independent reactions (respiration). The electron transfer in the examined DPPFCs is associated with a production of endogenous mediator, secreted by the duckweed. The plants' adaptive response to the applied polarization is also connected with an enhanced metabolism resulting in an increase of the protein and carbohydrate intracellular content. Further investigations aiming at improvement of the DPPFC outputs and elucidation of the electron transfer mechanism are required for practical application. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Wada-test, functional magnetic resonance imaging and direct electrical stimulation - brain mapping methods

    International Nuclear Information System (INIS)

    Minkin, K.; Tanova, R.; Busarski, A.; Penkov, M.; Penev, L.; Hadjidekov, V.

    2009-01-01

    Modern neurosurgery requires accurate preoperative and intraoperative localization of brain pathologies but also of brain functions. The presence of individual variations in healthy subjects and the shift of brain functions in brain diseases provoke the introduction of various methods for brain mapping. The aim of this paper was to analyze the most widespread methods for brain mapping: Wada-test, functional magnetic resonance imaging (fMRI) and intraoperative direct electrical stimulation (DES). This study included 4 patients with preoperative brain mapping using Wada-test and fMRI. Intraoperative mapping with DES during awake craniotomy was performed in one case. The histopathological diagnosis was low-grade glioma in 2 cases, cortical dysplasia (1 patient) and arteriovenous malformation (1 patient). The brain mapping permits total lesion resection in three of four patients. There was no new postoperative deficit despite surgery near or within functional brain areas. Brain plasticity provoking shift of eloquent areas from their usual locations was observed in two cases. The brain mapping methods allow surgery in eloquent brain areas recognized in the past as 'forbidden areas'. Each method has advantages and disadvantages. The precise location of brain functions and pathologies frequently requires combination of different brain mapping methods. (authors)

  1. Fabrication of flex sensors through direct ink write technique and its electrical characterization

    Science.gov (United States)

    Abas, Muhammad; Rahman, Khalid

    2016-11-01

    The present work is intended to fabricate low-cost flex sensor from conductive carbon paste using direct ink write (DIW) technique. DIW method is one of the additive manufacturing processes, which is capable to deposit a variety of material on a variety of substrates by a different mechanism to feature resolution at a microns level. It is widely used in the electronic industry for fabrication of PCBS and electrodes for different electronic devices. The DIW system in present study extrudes material stored in the syringe barrel through nozzle using compressed air. This mechanism will assist in creating patterns on a variety of substrates. Pneumatic controller is employed to control deposition of material, while computer-controlled X-Y stage is employed to control pattern generation. For effective and control patterning, printing parameters were optimized using Taguchi design optimization technique. The conductive carbon paste is used as ink for pattern generation on flexible PET substrate. Samples of flex sensor having different dimensions are prepared through DIW. The fabricated sensors were used as flexion sensor, and its electrical characteristic was evaluated. The obtained sensors are stable and reliable in performance.

  2. High temperature thermal conductivity measurements of UO2 by Direct Electrical Heating. Final report

    International Nuclear Information System (INIS)

    Bassett, B.

    1980-10-01

    High temperature properties of reactor type UO 2 pellets were measured using a Direct Electrical Heating (DEH) Facility. Modifications to the experimental apparatus have been made so that successful and reproducible DEH runs may be carried out while protecting the pellets from oxidation at high temperature. X-ray diffraction measurements on the UO 2 pellets have been made before and after runs to assure that sample oxidation has not occurred. A computer code has been developed that will model the experiment using equations that describe physical properties of the material. This code allows these equations to be checked by comparing the model results to collected data. The thermal conductivity equation for UO 2 proposed by Weilbacher has been used for this analysis. By adjusting the empirical parameters in Weilbacher's equation, experimental data can be matched by the code. From the several runs analyzed, the resulting thermal conductivity equation is lambda = 1/4.79 + 0.0247T/ + 1.06 x 10 -3 exp[-1.62/kT/] - 4410. exp[-3.71/kT/] where lambda is in w/cm K, k is the Boltzman constant, and T is the temperature in Kelvin

  3. MgB2 superconducting particles in a strong electric field

    International Nuclear Information System (INIS)

    Tao, R.; Xu, X.; Amr, E.

    2003-01-01

    The electric-field induced ball formation has been observed with MgB 2 powder in a strong static or quasi-static electric field. The effect of temperature and magnetic field on the ball formation shows surprising features. For quite a wide range of temperature from T c =39 K and below, the ball size is proportional to (1-T/T c ). As the temperature further goes below 20 K, the ball size becomes almost a constant. If MgB 2 particles are in a strong electric field and a moderate magnetic field, the electric-field induced balls align in the magnetic-field direction to form ball chains

  4. Particle concentrating and sorting under a rotating electric field by direct optical-liquid heating in a microfluidics chip.

    Science.gov (United States)

    Chen, Yu-Liang; Jiang, Hong-Ren

    2017-05-01

    We demonstrate a functional rotating electrothermal technique for rapidly concentrating and sorting a large number of particles on a microchip by the combination of particle dielectrophoresis (DEP) and inward rotating electrothermal (RET) flows. Different kinds of particles can be attracted (positive DEP) to or repelled (negative DEP) from electrode edges, and then the n-DEP responsive particles are further concentrated in the heated region by RET flows. The RET flows arise from the spatial inhomogeneous electric properties of fluid caused by direct infrared laser (1470 nm) heating of solution in a rotating electric field. The direction of the RET flows is radially inward to the heated region with a co-field (the same as the rotating electric field) rotation. Moreover, the velocity of the RET flows is proportional to the laser power and the square of the electric field strength. The RET flows are significant over a frequency range from 200 kHz to 5 MHz. The RET flows are generated by the simultaneous application of the infrared laser and the rotating electric field. Therefore, the location of particle concentrating can be controlled within the rotating electric field depending on the position of the laser spot. This multi-field technique can be operated in salt solutions and at higher frequency without external flow pressure, and thus it can avoid electrokinetic phenomena at low frequency to improve the manipulation accuracy for lab-on-chip applications.

  5. Steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Fang, Jiakun; Li, Jinghua

    2016-01-01

    Nowadays, the electric power system and natural gas network are becoming increasingly coupled and interdependent. A harmonized integration of natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables in terms of system...... flexibility. This work focuses on the steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion. A unified energy flow formulation is developed to describe the nodal balance and branch flow in both systems and it is solved with the Newton......–Raphson method. Both the unification of units and the per-unit system are proposed to simplify the system description and to enhance the computation efficiency. The applicability of the proposed method is demonstrated by analyzing an IEEE-9 test system integrated with a 7-node natural gas network. Later, time...

  6. Field-induced valence transition in rare-earth system

    International Nuclear Information System (INIS)

    Chattopadhaya, A.; Ghatak, S.K.

    2000-01-01

    The magnetic field-induced valence transition in rare-earth compound has been examined based on a pseudospin S=1 Ising model proposed earlier for valence transition. The model includes finite mixing between two pertinent ionic configurations (magnetic and non-magnetic) separated by an energy gap and with intersite interaction between rare-earth ions. Using the mean field approximation the magnetic behaviour and the critical field (H c ) for transition are obtained as a function of energy gap and temperature. The phase boundary defined in terms of reduced field H c /H co and reduced temperature T/T v (T v being valence transition temperature in absence of field) is nearly independent of energy gap. These results are in qualitative agreement with experimental observation in Yb- and Eu-compounds

  7. Fabrication and electrorotation of a novel epoxy based micromotor working in a uniform DC electric field

    Science.gov (United States)

    Bauer, Rita A.; Kelemen, Lóránd; Nakano, Masami; Totsuka, Atsushi; Zrínyi, Miklós

    2015-10-01

    We have presented the first direct observation of electric field induced rotation of epoxy based polymer rotors. Polymer disks, hollow cylinders and gears were prepared in few micrometer dimensions as rotors. Electrorotation of these sub-millimeter sized tools was studied under uniform dc electric field. The effects of shape, size and thickness were investigated. The novel epoxy based micro devices show intensive spinning in a uniform dc electric field. The rotational speed of micron-sized polymer rotors can be conveniently tuned in a wide range (between 300 and 3000 rpm) by the electric field intensity, opening new perspectives for their use in several MEMS applications.

  8. Fabrication and electrorotation of a novel epoxy based micromotor working in a uniform DC electric field

    International Nuclear Information System (INIS)

    Bauer, Rita A; Zrínyi, Miklós; Kelemen, Lóránd; Nakano, Masami; Totsuka, Atsushi

    2015-01-01

    We have presented the first direct observation of electric field induced rotation of epoxy based polymer rotors. Polymer disks, hollow cylinders and gears were prepared in few micrometer dimensions as rotors. Electrorotation of these sub-millimeter sized tools was studied under uniform dc electric field. The effects of shape, size and thickness were investigated. The novel epoxy based micro devices show intensive spinning in a uniform dc electric field. The rotational speed of micron-sized polymer rotors can be conveniently tuned in a wide range (between 300 and 3000 rpm) by the electric field intensity, opening new perspectives for their use in several MEMS applications. (paper)

  9. Field-induced transitions in DySb

    International Nuclear Information System (INIS)

    Brun, T.O.; Lander, G.H.; Korty, F.W.; Kouvel, J.S.

    1974-01-01

    The NaCl-structured compound DySb, which in zero field transforms abruptly at T/sub N/ approximately 9.5 0 K to a Type-II antiferromagnetic (A) state with a nearly tetragonal lattice distortion, was previously found to exhibit rapid field-induced changes in magnetization at 1.5 0 K. The field-induced transitions in a DySb crystal have been studied by neutron diffraction and magnetization measurements in fields up to approximately 60 kOe applied parallel to each of the principal axes. In the broken bracket 100 broken bracket case, the transition from the A to an intermediate ferrimagnetic (Q) state is first-order at 4.2 0 K (critical field H/sub c/ approximately 21 kOe) but is continuous from approximately 6 0 K up to T/sub N/: as H/sub c/ → 0. The Q-to-paramagnetic (P) transition is rapid but continuous at 4.2 0 K (H/sub c/ approximately 40 kOe) and becomes broad as T/sub N/ is approached. In the broken bracket 110 broken bracket case the A-to-Q transition remains essentially first-order from 4.2 0 K (H/sub c/ approximately 15 kOe) up to T/sub N/; above T/sub N/ rapid P-to-Q transitions occur at very high fields. The magnetic structure of the Q state is found to be that of HoP. (U.S.)

  10. Taxes for energy products, electricity and CO2. Consequences of the revision of the Energy Taxation Directive for the Netherlands

    International Nuclear Information System (INIS)

    Blom, M.J.; Schroten, A.; Geurts, F.

    2011-07-01

    Taxes on energy products, electricity and CO2 are compared for a number of EU countries (Germany, Belgium, Denmark, United Kingdom, France, Luxembourg, Spain, Sweden and the Netherlands) with special focus on the fiscal, economic and environmental impacts of the revision of the European Energy Directive for the Netherlands. [nl

  11. Renewable energies: development of photovoltaic for direct generation of electricity. Energias renovables: desarrollo tecnologia fotovoltaica de generacion directa de electricidad

    Energy Technology Data Exchange (ETDEWEB)

    Pantoja Lopez, A

    1994-01-01

    This article presents a study of photovoltaic to directly production electricity. Likewise the article presents the activities and projects of IBERDROLA. In the future the photovoltaic energy will grow after analyzing the efficiency, the operation of installations, market, R+D and technology. Economic and environmental aspects are analyzed as well.

  12. Three-port bi-directional converter for electric vehicles: focus on high-frequency coaxial transformer

    NARCIS (Netherlands)

    Waltrich, G.; Duarte, J.L.; Hendrix, M.A.M.; Paulides, J.J.H.

    2010-01-01

    A bi-directional multi-port converter can accommodate various energy storages and sources. Therefore, a multiport converter will be a good candidate for application as a future universal converter for (hybrid) electrical vehicles or local distribution systems. The main design challenge of the

  13. Influence of direct and alternating current electric fields on efficiency promotion and leaching risk alleviation of chelator assisted phytoremediation.

    Science.gov (United States)

    Luo, Jie; Cai, Limei; Qi, Shihua; Wu, Jian; Sophie Gu, Xiaowen

    2018-03-01

    Direct and alternating current electric fields with various voltages were used to improve the decontamination efficiency of chelator assisted phytoremediation for multi-metal polluted soil. The alleviation effect of electric field on leaching risk caused by chelator application during phytoremediation process was also evaluated. Biomass yield, pollutant uptake and metal leaching retardation under alternating current (AC) and direct current (DC) electric fields were compared. The biomass yield of Eucalyptus globulus under AC fields with various voltages (2, 4 and 10 V) were 3.91, 4.16 and 3.67kg, respectively, significantly higher than the chelator treatment without electric field (2.71kg). Besides growth stimulation, AC fields increased the metal concentrations of plant tissues especially in aerial parts manifested by the raised translocation factor of different metals. Direct current electric fields with low and moderate voltages increased the biomass production of the species to 3.45 and 3.12kg, respectively, while high voltage on the contrary suppressed the growth of the plants (2.66kg). Under DC fields, metal concentrations elevated obviously with increasing voltages and the metal translocation factors were similar under all voltages. Metal extraction per plant achieved the maximum value under moderate voltage due to the greatest biomass production. DC field with high voltage (10V) decreased the volume of leachate from the chelator treatment without electric field from 1224 to 56mL, while the leachate gathered from AC field treatments raised from 512 to 670mL. DC field can retard the downward movement of metals caused by chelator application more effectively relative to AC field due to the constant water flow and electroosmosis direction. Alternating current field had more promotive effect on chelator assisted phytoremediation efficiency than DC field illustrated by more metal accumulation in the species. However, with the consideration of leaching risk, DC

  14. Validating computationally predicted TMS stimulation areas using direct electrical stimulation in patients with brain tumors near precentral regions.

    Science.gov (United States)

    Opitz, Alexander; Zafar, Noman; Bockermann, Volker; Rohde, Veit; Paulus, Walter

    2014-01-01

    The spatial extent of transcranial magnetic stimulation (TMS) is of paramount interest for all studies employing this method. It is generally assumed that the induced electric field is the crucial parameter to determine which cortical regions are excited. While it is difficult to directly measure the electric field, one usually relies on computational models to estimate the electric field distribution. Direct electrical stimulation (DES) is a local brain stimulation method generally considered the gold standard to map structure-function relationships in the brain. Its application is typically limited to patients undergoing brain surgery. In this study we compare the computationally predicted stimulation area in TMS with the DES area in six patients with tumors near precentral regions. We combine a motor evoked potential (MEP) mapping experiment for both TMS and DES with realistic individual finite element method (FEM) simulations of the electric field distribution during TMS and DES. On average, stimulation areas in TMS and DES show an overlap of up to 80%, thus validating our computational physiology approach to estimate TMS excitation volumes. Our results can help in understanding the spatial spread of TMS effects and in optimizing stimulation protocols to more specifically target certain cortical regions based on computational modeling.

  15. Decentralized energy management strategy based on predictive controllers for a medium voltage direct current photovoltaic electric vehicle charging station

    International Nuclear Information System (INIS)

    Torreglosa, Juan P.; García-Triviño, Pablo; Fernández-Ramirez, Luis M.; Jurado, Francisco

    2016-01-01

    Highlights: • Electric vehicle charging station supplied by photovoltaic, batteries and grid connection is analyzed. • The bus voltage is the key parameter for controlling the system by decentralized approach. • Decentralized control approach facilities the enlargement of the system. • Photovoltaic and battery systems are controlled by model predictive controllers. • Response by model predictive controllers improves that by PI controllers. - Abstract: The use of distributed charging stations based on renewable energy sources for electric vehicles has increased in recent years. Combining photovoltaic solar energy and batteries as energy storage system, directly tied into a medium voltage direct current bus, and with the grid support, results to be an interesting option for improving the operation and efficiency of electric vehicle charging stations. In this paper, an electric vehicle charging station supplied by photovoltaic solar panels, batteries and with grid connection is analysed and evaluated. A decentralized energy management system is developed for regulating the energy flow among the photovoltaic system, the battery and the grid in order to achieve the efficient charging of electric vehicles. The medium voltage direct current bus voltage is the key parameter for controlling the system. The battery is controlled by a model predictive controller in order to keep the bus voltage at its reference value. Depending on the state-of-charge of the battery and the bus voltage, the photovoltaic system can work at maximum power point tracking mode or at bus voltage sustaining mode, or even the grid support can be needed. The results demonstrate the proper operation and energy management of the electric vehicle charging station under study.

  16. A Comprehensive Study of Key Electric Vehicle (EV Components, Technologies, Challenges, Impacts, and Future Direction of Development

    Directory of Open Access Journals (Sweden)

    Fuad Un-Noor

    2017-08-01

    Full Text Available Electric vehicles (EV, including Battery Electric Vehicle (BEV, Hybrid Electric Vehicle (HEV, Plug-in Hybrid Electric Vehicle (PHEV, Fuel Cell Electric Vehicle (FCEV, are becoming more commonplace in the transportation sector in recent times. As the present trend suggests, this mode of transport is likely to replace internal combustion engine (ICE vehicles in the near future. Each of the main EV components has a number of technologies that are currently in use or can become prominent in the future. EVs can cause significant impacts on the environment, power system, and other related sectors. The present power system could face huge instabilities with enough EV penetration, but with proper management and coordination, EVs can be turned into a major contributor to the successful implementation of the smart grid concept. There are possibilities of immense environmental benefits as well, as the EVs can extensively reduce the greenhouse gas emissions produced by the transportation sector. However, there are some major obstacles for EVs to overcome before totally replacing ICE vehicles. This paper is focused on reviewing all the useful data available on EV configurations, battery energy sources, electrical machines, charging techniques, optimization techniques, impacts, trends, and possible directions of future developments. Its objective is to provide an overall picture of the current EV technology and ways of future development to assist in future researches in this sector.

  17. Comprehensive Technical Report, General Electric Direct-Air-Cycle Aircraft Nuclear Propulsion Program, Program Summary and References

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, G.; Rothstein, A.J.

    1962-06-28

    This is one of twenty-one volumes sumarizing the Aircraft Nuclear Propulsion Program of the General Electric Company. This volume discusses the background to the General Electric program, and summarizes the various direct-air-cycle nuclear test assemblies and power plants that were developed. Because of the requirements of high performance, low weight, and small size, vast improvements in existing technology were required to meet the flight objectives. The technological progress achieved during the program is also summarized. The last appendix contains a compilation of the abstracts, tables of contents, and reference lists of the other twenty volumes.

  18. Direct thermal to electrical energy conversion using 9.5/65/35 PLZT ceramics in the ergodic relaxor phase.

    Science.gov (United States)

    Chin, Thomas K; Lee, Felix Y; McKinley, Ian M; Goljahi, Sam; Lynch, Christopher S; Pilon, Laurent

    2012-11-01

    This paper reports on direct thermal to electrical energy conversion by performing the Olsen cycle on 9.5/65/35 lead lanthanum zirconate titanate (PLZT). The Olsen cycle consists of two isothermal and two isoelectric field processes in the electric displacement versus electric field diagram. It was performed by alternatively dipping the material in hot and cold dielectric fluid baths under specified electric fields. The effects of applied electric field, sample thickness, electrode material, operating temperature, and cycle frequency on the energy and power densities were investigated. A maximum energy density of 637 ± 20 J/L/cycle was achieved at 0.054 Hz with a 250-μm-thick sample featuring Pt electrodes and coated with a silicone conformal coating. The operating temperatures varied between 3°C and 140°C and the electric field was cycled between 0.2 and 6.0 MV/m. A maximum power density of 55 ± 8 W/L was obtained at 0.125 Hz under the same operating temperatures and electric fields. The dielectric strength of the material, and therefore the energy and power densities generated, increased when the sample thickness decreased from 500 to 250 μm. Furthermore, the electrode material was found to have no significant effect on the energy and power densities for samples subject to the same operating temperatures and electric fields. However, samples with electrode material possessing thermal expansion coefficients similar to that of PLZT were capable of withstanding larger temperature swings. Finally, a fatigue test showed that the power generation gradually degraded when the sample was subject to repeated thermoelectrical loading.

  19. Direct quantification of transendothelial electrical resistance in organs-on-chips

    NARCIS (Netherlands)

    van der Helm, Marieke Willemijn; Odijk, Mathieu; Frimat, Jean-Philippe; van der Meer, Andries Dirk; Eijkel, Jan C.T.; van den Berg, Albert; Segerink, Loes Irene

    2016-01-01

    Measuring transendothelial or transepithelial electrical resistance (TEER) is a widely used method to monitor cellular barrier tightness in organs-on-chips. Unfortunately, integrated electrodes close to the cellular barrier hamper visual inspection of the cells or require specialized cleanroom

  20. Ar-Xe Laser: The Path to a Robust, All-Electric Shipboard Directed Energy Weapon

    National Research Council Canada - National Science Library

    Apruzese, J. P; Sethian, J. D; Giuliani, J. L; Wolford, M. F

    2008-01-01

    .... However, no HELs have been deployed to date. Until recently, there was no laser that had credible prospects of meeting the Navy's requirements for safety, power, size, beam quality, electrical drive, and atmospheric propagation...

  1. Direct measurement of macroscopic electric fields produced by collective effects in electron-impact experiments

    International Nuclear Information System (INIS)

    Velotta, R.; Avaldi, L.; Camilloni, R.; Giammanco, F.; Spinelli, N.; Stefani, G.

    1996-01-01

    The macroscopic electric field resulting from the space charge produced in electron-impact experiments has been characterized by using secondary electrons of well-defined energy (e.g., Auger or autoionizing electrons) as a probe. It is shown that the measurement of the kinetic-energy shifts suffered by secondary electrons is a suitable tool for the analysis of the self-generated electric field in a low-density plasma. copyright 1996 The American Physical Society

  2. Directly calculated electrical conductivity of hot dense hydrogen from molecular dynamics simulation beyond Kubo-Greenwood formula

    Science.gov (United States)

    Ma, Qian; Kang, Dongdong; Zhao, Zengxiu; Dai, Jiayu

    2018-01-01

    Electrical conductivity of hot dense hydrogen is directly calculated by molecular dynamics simulation with a reduced electron force field method, in which the electrons are represented as Gaussian wave packets with fixed sizes. Here, the temperature is higher than electron Fermi temperature ( T > 300 eV , ρ = 40 g / cc ). The present method can avoid the Coulomb catastrophe and give the limit of electrical conductivity based on the Coulomb interaction. We investigate the effect of ion-electron coupled movements, which is lost in the static method such as density functional theory based Kubo-Greenwood framework. It is found that the ionic dynamics, which contributes to the dynamical electrical microfield and electron-ion collisions, will reduce the conductivity significantly compared with the fixed ion configuration calculations.

  3. Double hydrogen bonded ferroelectric liquid crystals: A study of field induced transition (FiT)

    Science.gov (United States)

    Vijayakumar, V. N.; Madhu Mohan, M. L. N.

    2009-12-01

    A novel series of chiral hydrogen bonded liquid crystals have been isolated. Hydrogen bond was formed between chiral nonmesogen ingredient levo tartaric acid and mesogenic p-n-alkoxybenzoic acids. Phase diagram was constructed from the transition temperatures obtained by DSC and polarizing optical microscopic (POM) studies. Thermal and electrical properties exhibited by three complexes namely LTA+8BA, LTA+7BA and LTA+5BA were discussed. Salient feature of the present work was the observation of a reentrant smectic ordering in LTA+8BA complex designated as C r∗ phase. This reentrant phenomenon was confirmed by DSC thermograms, optical textures of POM and temperature variation of capacitance and dielectric loss studies. Tilt angle was measured in smectic C ∗ and reentrant smectic C r∗ phases. Another interesting feature of the present investigation was the observation of a field induced transition (FiT) in the LTA+ nBA homologous series. Three threshold field values were noticed which give rise to two new phases (E 1 and E 2) induced by electric field and on further enhancement of the applied field the mesogen behaves like an optical shutter. FiT is reversible in the sense that when applied field is removed the original texture was restored.

  4. Observatory geoelectric fields induced in a two-layer lithosphere during magnetic storms

    Science.gov (United States)

    Love, Jeffrey J.; Swidinsky, Andrei

    2015-01-01

    We report on the development and validation of an algorithm for estimating geoelectric fields induced in the lithosphere beneath an observatory during a magnetic storm. To accommodate induction in three-dimensional lithospheric electrical conductivity, we analyze a simple nine-parameter model: two horizontal layers, each with uniform electrical conductivity properties given by independent distortion tensors. With Laplace transformation of the induction equations into the complex frequency domain, we obtain a transfer function describing induction of observatory geoelectric fields having frequency-dependent polarization. Upon inverse transformation back to the time domain, the convolution of the corresponding impulse-response function with a geomagnetic time series yields an estimated geoelectric time series. We obtain an optimized set of conductivity parameters using 1-s resolution geomagnetic and geoelectric field data collected at the Kakioka, Japan, observatory for five different intense magnetic storms, including the October 2003 Halloween storm; our estimated geoelectric field accounts for 93% of that measured during the Halloween storm. This work demonstrates the need for detailed modeling of the Earth’s lithospheric conductivity structure and the utility of co-located geomagnetic and geoelectric monitoring.

  5. Electricity

    International Nuclear Information System (INIS)

    Tombs, F.

    1983-01-01

    The subject is discussed, with particular reference to the electricity industry in the United Kingdom, under the headings; importance and scope of the industry's work; future fuel supplies (estimated indigenous fossil fuels reserves); outlook for UK energy supplies; problems of future generating capacity and fuel mix (energy policy; construction programme; economics and pricing; contribution of nuclear power - thermal and fast reactors; problems of conversion of oil-burning to coal-burning plant). (U.K.)

  6. Two-electron states in double quantum dot in direct electric field

    International Nuclear Information System (INIS)

    Burdov, V.A.

    2001-01-01

    One determined analytically the wave functions of stationary states and the spectrum of two-electron system in symmetric binary quantum point. It is shown that in the normal state at the absence of external electric field the electrons due to the Coulomb blockade can not be collectively in one quantum point. In the external electric field the situation changes. When a certain critical value of field intensity is reached the probability of detection of both electrons in one quantum point by a jump increases from zero up to 1 [ru

  7. Cooperation of electrically stimulated muscle and pneumatic muscle to realize RUPERT bi-directional motion for grasping.

    Science.gov (United States)

    Xikai Tu; Jiping He; Yue Wen; Jian Huang; Xinhan Huang; Hailong Huang; Meng Guo; Yong Yuan

    2014-01-01

    Robot-assisted rehabilitation is an active area of research to meet the demand of repetitive therapy in stroke rehabilitation. Robotic upper-extremity repetitive trainer (RUPERT) with its unidirectional pneumatic muscle actuation (PMA) can be used by most stroke patients that have difficulty moving in one direction because of a weak agonist or hyperactive antagonist. In this research, to broaden the usage of RUPERT, we not only add grasping functionality to the rehabilitation robot with the help of surface Functional Electrical Stimulation (FES) but also realize the robot joint bi-directional motion by using a PMA in cooperation with surface FES evoked paralyzed muscle force. This integrative rehabilitation strategy is explored for training patients to practice coordinated reaching and grasping functions. The effectiveness of this FES electrically evoked bio-actuator way is verified through a method that separates the mixed electromyogram (MEMG) into the electrically evoked electromyogram (EEMG) and voluntary electromyogram (VEMG). This is a promising approach to alleviate the size and mechanical complexity of the robot, thereby the cost of the joint bi-directional actuator rehabilitation robot by means of their own characteristics of stroke subjects.

  8. Deformation Study of Lean Methane-Air Premixed Spherically Expanding Flames under a Negative Direct Current Electric Field

    Directory of Open Access Journals (Sweden)

    Chao Li

    2016-09-01

    Full Text Available This paper compares numerical simulations with experiments to study the deformation of lean premixed spherically expanding flames under a negative direct current (DC electric field. The experiments, including the flame deformation and the ionic distribution on the flame surface were investigated in a mesh to mesh electric field. Besides, a numerical model of adding an electric body force to the positive ions on the flame surface was also established to perform a relevant simulation. Results show that the spherical flame will acquire an elliptical shape with a marked flame stretch in the horizontal direction and a slight inhibition in the vertical direction under a negative DC electric field. Meanwhile, a non-uniform ionic distribution on the flame surface was also detected by the Langmuir probe. The simulation results from the numerical model show good agreement with experimental data. According to the velocity field analysis in simulation, it was found the particular motion of positive ions and neutral molecules on the flame surface should be responsible for the special flame deformation. When a negative DC electric field was applied, the majority of positive ions and colliding neutral molecules will form an ionic flow along the flame surface by a superposition of the electric field force and the aerodynamic drag. The ionic flow was not uniform and mainly formed on the upper and lower sides, so it will lead to a non-uniform ionic distribution along the flame surface. What’s more, this ionic flow will also induce two vortexes both inside and outside of the flame surface due to viscosity effects. The external vortexes could produce an entraining effect on the premixed gas and take away the heat from the flame surface by forced convection, and then suppress the flame propagation in the vertical direction, while, the inner vortexes would scroll the burned zones and induce an inward flow at the horizontal center, which could be the reason for the

  9. Direct observations of surface water-groundwater interaction using electrical resistivity tomography

    NARCIS (Netherlands)

    Noell, Ursula; Wießner, Claudia; Ganz, Christina; Westhoff, Martijn

    2011-01-01

    Electrical resistivity tomography is a helpful tool to observe the infiltration process in and through the soil. Array 3-D measurements and 3-D inversion schemes are required for reliable interpretation of heterogeneous subsurface structures. Smoothing of the inversion can be minimized by using

  10. Energy and spectrum of BeO molecule under the electric field from different directions

    NARCIS (Netherlands)

    Jiang, M.; Guo, F. J.; Yan, A. Y.; Zhang, C. W.; Miao, F.

    2010-01-01

    Based on the density functional theory DFT/ B3LYP at 6-311g level, the ground states of BeO molecule are optimized. The effects of electric field on the bond length, the system energy, the charge distribution, the energy levels, the HOMO-LUMO gaps and the infrared spectrum of BeO molecule are

  11. Impact of electricity prices on foreign direct investment: Evidence from the European Union

    NARCIS (Netherlands)

    Bartekova, E.; Ziesemer, T.H.W.

    2015-01-01

    In the course of recent years growing concerns over increasing energy prices have emerged in the context of maintaining Europe’s international competitiveness. In particular, rising electricity price differentials adversely affect firms’ total production costs and ultimately impact their investment

  12. The Characteristics of Electromagnetic Fields Induced by Different Type Sources

    Science.gov (United States)

    Di, Q.; Fu, C.; Wang, R.; Xu, C.; An, Z.

    2011-12-01

    Controlled source audio-frequence magnetotelluric (CSAMT) method has played an important role in the shallow exploration (less than 1.5km) in the field of resources, environment and engineering geology. In order to prospect the deeper target, one has to increase the strength of the source and offset. However, the exploration is nearly impossible for the heavy larger power transmitting source used in the deeper prospecting and mountain area. So an EM method using a fixed large power source, such as long bipole current source, two perpendicular "L" shape long bipole current source and large radius circle current source, is beginning to take shape. In order to increase the strength of the source, the length of the transmitting bipole in one direction or in perpendicular directions has to be much larger, such as L=100km, or the radius of the circle current source is much larger. The electric field strength are IL2and IL2/4π separately for long bipole source and circle current source with the same wire length. Just considering the effectiveness of source, the strength of the circle current source is larger than that of long bipole source if is large enough. However, the strength of the electromagnetic signal doesn't totally depend on the transmitting source, the effect of ionosphere on the electromagnetic (EM) field should be considered when observation is carried at a very far (about several thousands kilometers) location away from the source for the long bipole source or the large radius circle current source. We firstly calculate the electromagnetic fields with the traditional controlled source (CSEM) configuration using the integral equation (IE) code developed by our research group for a three layers earth-ionosphere model which consists of ionosphere, atmosphere and earth media. The modeling results agree well with the half space analytical results because the effect of ionosphere for this small scale source can be ignorable, which means the integral equation

  13. Stress- and Magnetic Field-Induced Martensitic Transformation at Cryogenic Temperatures in Fe-Mn-Al-Ni Shape Memory Alloys

    Science.gov (United States)

    Xia, Ji; Xu, Xiao; Miyake, Atsushi; Kimura, Yuta; Omori, Toshihiro; Tokunaga, Masashi; Kainuma, Ryosuke

    2017-12-01

    Stress-induced and magnetic-field-induced martensitic transformation behaviors at low temperatures were investigated for Fe-Mn-Al-Ni alloys. The magnetic-field-induced reverse martensitic transformation was directly observed by in situ optical microscopy. Magnetization measurements under pulsed magnetic fields up to 50 T were carried out at temperatures between 4.2 and 125 K on a single-crystal sample; full magnetic-field-induced reverse martensitic transformation was confirmed at all tested temperatures. Compression tests from 10 to 100 K were conducted on a single-crystal sample; full shape recovery was obtained at all tested temperatures. It was found that the temperature dependence of both the critical stress and critical magnetic field is small and that the transformation hysteresis is less sensitive to temperature even at cryogenic temperatures. The temperature dependence of entropy change during martensitic transformation up to 100 K was then derived using the Clausius-Clapeyron relation with critical stresses and magnetic fields.

  14. COMETS2: An advanced MATLAB toolbox for the numerical analysis of electric fields generated by transcranial direct current stimulation.

    Science.gov (United States)

    Lee, Chany; Jung, Young-Jin; Lee, Sang Jun; Im, Chang-Hwan

    2017-02-01

    Since there is no way to measure electric current generated by transcranial direct current stimulation (tDCS) inside the human head through in vivo experiments, numerical analysis based on the finite element method has been widely used to estimate the electric field inside the head. In 2013, we released a MATLAB toolbox named COMETS, which has been used by a number of groups and has helped researchers to gain insight into the electric field distribution during stimulation. The aim of this study was to develop an advanced MATLAB toolbox, named COMETS2, for the numerical analysis of the electric field generated by tDCS. COMETS2 can generate any sizes of rectangular pad electrodes on any positions on the scalp surface. To reduce the large computational burden when repeatedly testing multiple electrode locations and sizes, a new technique to decompose the global stiffness matrix was proposed. As examples of potential applications, we observed the effects of sizes and displacements of electrodes on the results of electric field analysis. The proposed mesh decomposition method significantly enhanced the overall computational efficiency. We implemented an automatic electrode modeler for the first time, and proposed a new technique to enhance the computational efficiency. In this paper, an efficient toolbox for tDCS analysis is introduced (freely available at http://www.cometstool.com). It is expected that COMETS2 will be a useful toolbox for researchers who want to benefit from the numerical analysis of electric fields generated by tDCS. Copyright © 2016. Published by Elsevier B.V.

  15. Terahertz-field-induced photoluminescence of nanostructured gold films

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Malureanu, Radu; Zalkovskij, Maksim

    2013-01-01

    We experimentally demonstrate photoluminescence from nanostructured ultrathin gold films subjected to strong single-cycle terahertz transients with peak electric field over 300 kV/cm. We show that UV-Vis-NIR light is being generated and the efficiency of the process is strongly enhanced at the pe......We experimentally demonstrate photoluminescence from nanostructured ultrathin gold films subjected to strong single-cycle terahertz transients with peak electric field over 300 kV/cm. We show that UV-Vis-NIR light is being generated and the efficiency of the process is strongly enhanced...

  16. Direct Electrical Stimulation of the Human Entorhinal Region and Hippocampus Impairs Memory.

    Science.gov (United States)

    Jacobs, Joshua; Miller, Jonathan; Lee, Sang Ah; Coffey, Tom; Watrous, Andrew J; Sperling, Michael R; Sharan, Ashwini; Worrell, Gregory; Berry, Brent; Lega, Bradley; Jobst, Barbara C; Davis, Kathryn; Gross, Robert E; Sheth, Sameer A; Ezzyat, Youssef; Das, Sandhitsu R; Stein, Joel; Gorniak, Richard; Kahana, Michael J; Rizzuto, Daniel S

    2016-12-07

    Deep brain stimulation (DBS) has shown promise for treating a range of brain disorders and neurological conditions. One recent study showed that DBS in the entorhinal region improved the accuracy of human spatial memory. Based on this line of work, we performed a series of experiments to more fully characterize the effects of DBS in the medial temporal lobe on human memory. Neurosurgical patients with implanted electrodes performed spatial and verbal-episodic memory tasks. During the encoding periods of both tasks, subjects received electrical stimulation at 50 Hz. In contrast to earlier work, electrical stimulation impaired memory performance significantly in both spatial and verbal tasks. Stimulation in both the entorhinal region and hippocampus caused decreased memory performance. These findings indicate that the entorhinal region and hippocampus are causally involved in human memory and suggest that refined methods are needed to use DBS in these regions to improve memory. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Direct conversion of fusion energy into the electric one in the 'Dragon' magnetic confinement system

    International Nuclear Information System (INIS)

    Glagolev, V.M.; Timofeev, A.V.

    1993-01-01

    It is shown that recuperator in which the thermal energy of particles is transformed into electric oue under drift in crossed fields is naturally coupled with dragontype magnetic confinement system, so the recuperation process can be initiated in the dragon magnetic field. A number of questions occuring under analysis of recuperator-dragon system is considered, including the dynamics of particle transfer to the recuperator, the share of particles entering the recuperator, the effect of rotational transform and the recuperation efficiency

  18. Forces that direct the competition in the electric power industry in the new institutional scenery

    International Nuclear Information System (INIS)

    Ribeiro Filho, Ary Pinto; Moraes, Walter Fernando Araujo de

    1999-01-01

    This work identifies the probable strategic characteristics of the interconnected North-Northeast Brazilian electricity industry, after the current restructuring and privatization process has been implemented. It is a 15.0 thousand MW generation industry supplying more than 33.5 million consumers. The normative scenery for analysis of the electricity industry takes into consideration the premises that the government establishes the vertical separation of generation, transmission, distribution and retailing, and introduces the regulation to a competitive industrial structure in generation and retailing. It is assumed that free access to transmit and distribute electricity and broad choices for consumers are the main features for competition in both generation and retailing. The essence of formulating strategy is to relate a company with its environment, considering the industrial structure. Porter's five forces model for industry environment and competition, emphasizing the role of the government in such regulated industry, is the basic theoretical reference. The main strategic characteristics related to entry barriers, rivalry intensity, supplier power, customer power and substitute products are analyzed. (author)

  19. Direct electrical control of IgG conformation and functional activity at surfaces

    Science.gov (United States)

    Ghisellini, Paola; Caiazzo, Marialuisa; Alessandrini, Andrea; Eggenhöffner, Roberto; Vassalli, Massimo; Facci, Paolo

    2016-11-01

    We have devised a supramolecular edifice involving His-tagged protein A and antibodies to yield surface immobilized, uniformly oriented, IgG-type, antibody layers with Fab fragments exposed off an electrode surface. We demonstrate here that we can affect the conformation of IgGs, likely pushing/pulling electrostatically Fab fragments towards/from the electrode surface. A potential difference between electrode and solution acts on IgGs’ charged aminoacids modulating the accessibility of the specific recognition regions of Fab fragments by antigens in solution. Consequently, antibody-antigen affinity is affected by the sign of the applied potential: a positive potential enables an effective capture of antigens; a negative one pulls the fragments towards the electrode, where steric hindrance caused by neighboring molecules largely hampers the capture of antigens. Different experimental techniques (electrochemical quartz crystal microbalance, electrochemical impedance spectroscopy, fluorescence confocal microscopy and electrochemical atomic force spectroscopy) were used to evaluate binding kinetics, surface coverage, effect of the applied electric field on IgGs, and role of charged residues on the phenomenon described. These findings expand the concept of electrical control of biological reactions and can be used to gate electrically specific recognition reactions with impact in biosensors, bioactuators, smart biodevices, nanomedicine, and fundamental studies related to chemical reaction kinetics.

  20. New Directions in EEG Measurement: an Investigation into the Fidelity of Electrical Potential Sensor Signals

    Directory of Open Access Journals (Sweden)

    M. FATOORECHI

    2015-01-01

    Full Text Available Low frequency noise performance is the key indicator in determining the signal to noise ratio of a capacitively coupled sensor when used to acquire electroencephalogram signals. For this reason, a prototype Electric Potential Sensor device based on an auto-zero operational amplifier has been developed and evaluated. The absence of 1/f noise in these devices makes them ideal for use with signal frequencies ~10 Hz or less. The active electrodes are designed to be physically and electrically robust and chemically and biochemically inert. They are electrically insulated (anodized and have diameters of 12 mm or 18 mm. In both cases, the sensors are housed in inert stainless steel machined housings with the electronics fabricated in surface mount components on a printed circuit board compatible with epoxy potting compounds. Potted sensors are designed to be immersed in alcohol for sterilization purposes. A comparative study was conducted with a commercial wet gel electrode system. These studies comprised measurements of both free running electroencephalogram and Event Related Potentials. Quality of the recorded electroencephalogram was assessed using three methods of inspection of raw signal, comparing signal to noise ratios, and Event Related Potentials noise analysis. A strictly comparable signal to noise ratio was observed and the overall conclusion from these comparative studies is that the noise performance of the new sensor is appropriate.

  1. Climate impact and energy efficiency from electricity generation through anaerobic digestion or direct combustion of short rotation coppice willow

    International Nuclear Information System (INIS)

    Ericsson, Niclas; Nordberg, Åke; Sundberg, Cecilia; Ahlgren, Serina; Hansson, Per-Anders

    2014-01-01

    Highlights: • Using LCA, CHP from willow use in biogas was compared with direct combustion. • Direct combustion was ninefold more energy-efficient. • Biogas had a much greater cooling effect on global mean surface temperature. • The effects of soil carbon changes on temperature over time differed. • Biogas had long-term temperature effects, direct combustion short-term effects. - Abstract: Short rotation coppice willow is an energy crop used in Sweden to produce electricity and heat in combined heat and power plants. Recent laboratory-scale experiments have shown that SRC willow can also be used for biogas production in anaerobic digestion processes. Here, life cycle assessment is used to compare the climate impact and energy efficiency of electricity and heat generated by these measures. All energy inputs and greenhouse gas emissions, including soil organic carbon fluxes were included in the life cycle assessment. The climate impact was determined using time-dependent life cycle assessment methodology. Both systems showed a positive net energy balance, but the direct combustion system delivered ninefold more energy than the biogas system. Both systems had a cooling effect on the global mean surface temperature change. The cooling impact per hectare from the biogas system was ninefold higher due to the carbon returned to soil with the digestate. Compensating the lower energy production of the biogas system with external energy sources had a large impact on the result, effectively determining whether the biogas scenario had a net warming or cooling contribution to the global mean temperature change per kWh of electricity. In all cases, the contribution to global warming was lowered by the inclusion of willow in the energy system. The use of time-dependent climate impact methodology shows that extended use of short rotation coppice willow can contribute to counteract global warming

  2. Field-Induced Texturing of Ceramic Materials for Unparalleled Properties

    Science.gov (United States)

    2017-03-01

    Texturing of Ceramic Materials for Unparalleled Properties by...influence over many properties , such as optical transparency, strength, electrical conductivity, and piezoelectricity .19 Highly textured materials are... Ceramic Materials for Unparalleled Properties by Raymond Brennan, Victoria Blair, Nicholas Ku, Krista Limmer, Tanya Chantawansri, Mahesh

  3. Current bistability in a weakly coupled multi-quantum well structure: a magnetic field induced 'memory effect'

    International Nuclear Information System (INIS)

    Feu, W H M; Villas-Boas, J M; Cury, L A; Guimaraes, P S S; Vieira, G S; Tanaka, R Y; Passaro, A; Pires, M P; Landi, S M; Souza, P L

    2009-01-01

    A study of magnetotunnelling in weakly coupled multi-quantum wells reveals a new phenomenon which constitutes a kind of memory effect in the sense that the electrical resistance of the sample after application of the magnetic field is different from before and contains the information that a magnetic field was applied previously. The change in the electric field domain configuration triggered by the magnetic field was compared for two samples, one strictly periodic and another with a thicker quantum well inserted into the periodic structure. For applied biases at which two electric field domains are present in the sample, as the magnetic field is increased a succession of discontinuous reductions in the electrical resistance is observed due to the magnetic field-induced rearrangement of the electric field domains, i.e. the domain boundary jumps from well to well as the magnetic field is changed. The memory effect is revealed for the aperiodic structure as the electric field domain configuration triggered by the magnetic field remains stable after the field is reduced back to zero. This effect is related to the multi-stability in the current-voltage characteristics observed in some weakly coupled multi-quantum well structures.

  4. Direct participation of electrical loads in the California independent system operator markets during the Summer of 2000

    International Nuclear Information System (INIS)

    Marnay, Chris; Hamachi, Kristina S.; Khavkin, Mark; Siddiqui, Afzal S.

    2001-01-01

    California's restructured electricity markets opened on 1 April 1998. The former investor-owned utilities were functionally divided into generation, transmission, and distribution activities, all of their gas-fired generating capacity was divested, and the retail market was opened to competition. To ensure that small customers shared in the expected benefit of lower prices, the enabling legislation mandated a 10% rate cut for all customers, which was implemented in a simplistic way that fossilized 1996 tariff structures. Rising fuel and environmental compliance costs, together with a reduced ability to import electricity, numerous plant outages, and exercise of market power by generators drove up wholesale electricity prices steeply in 2000, while retail tariffs remained unchanged. One of the distribution/supply companies entered bankruptcy in April 2001, and another was insolvent. During this period, two sets of interruptible load programs were in place, longstanding ones organized as special tariffs by the distribution/supply companies and hastily established ones run directly by the California Independent System Operator (CAISO). The distribution/supply company programs were effective at reducing load during the summer of 2000, but because of the high frequency of outages required by a system on the brink of failure, customer response declined and many left the tariff. The CAISO programs failed to attract enough participation to make a significant difference to the California supply demand imbalance. The poor performance of direct load participation in California's markets reinforces the argument for accurate pricing of electricity as a stimulus to energy efficiency investment and as a constraint on market volatility

  5. Transverse Space-Charge Field-Induced Plasma Dynamics for Ultraintense Electron-Beam Characterization

    Directory of Open Access Journals (Sweden)

    R. Tarkeshian

    2018-05-01

    Full Text Available Similarly to laser or x-ray beams, the interaction of sufficiently intense particle beams with neutral gases will result in the creation of plasma. In contrast to photon-based ionization, the strong unipolar field of a particle beam can generate a plasma where the electron population receives a large initial momentum kick and escapes, leaving behind unshielded ions. Measuring the properties of the ensuing Coulomb exploding ions—such as their kinetic energy distribution, yield, and spatial distribution—can provide information about the peak electric fields that are achieved in the electron beams. Particle-in-cell simulations and analytical models are presented for high-brightness electron beams of a few femtoseconds or even hundreds of attoseconds, and transverse beam sizes on the micron scale, as generated by today’s free electron lasers. Different density regimes for the utilization as a potential diagnostics are explored, and the fundamental differences in plasma dynamical behavior for e-beam or photon-based ionization are highlighted. By measuring the dynamics of field-induced ions for different gas and beam densities, a lower bound on the beam charge density can be obtained in a single shot and in a noninvasive way. The exponential dependency of the ionization yield on the beam properties can provide unprecedented spatial and temporal resolution, at the submicrometer and subfemtosecond scales, respectively, offering a practical and powerful approach to characterizing beams from accelerators at the frontiers of performance.

  6. The field induced e31,f piezoelectric and Rayleigh response in barium strontium titanate thin films

    International Nuclear Information System (INIS)

    Garten, L. M.; Trolier-McKinstry, S.

    2014-01-01

    The electric field induced e 31,f piezoelectric response and tunability of Ba 0.7 Sr 0.3 TiO 3 (70:30) and Ba 0.6 Sr 0.4 TiO 3 (60:40) thin films on MgO and silicon was measured. The relative dielectric tunabilities for the 70:30 and 60:40 compositions on MgO were 83% and 70%, respectively, with a dielectric loss of less than 0.011 and 0.004 at 100 kHz. A linear increase in induced piezoelectricity to −3.0 C/m 2 and −1.5 C/m 2 at 110 kV/cm was observed in Ba 0.6 Sr 0.4 TiO 3 on MgO and Ba 0.7 Sr 0.3 TiO 3 on Si. Hysteresis in the piezoelectric and dielectric response of the 70:30 composition films was consistent with the positive irreversible dielectric Rayleigh coefficient. Both indicate a ferroelectric contribution to the piezoelectric and dielectric response over 40–80 °C above the global paraelectric transition temperature.

  7. Analysis and control of excitation, field weakening and stability in direct torque controlled electrically excited synchronous motor drives

    Energy Technology Data Exchange (ETDEWEB)

    Pyrhoenen, O

    1999-12-31

    Direct torque control (DTC) is a new control method for rotating field electrical machines. DTC controls directly the motor stator flux linkage with the stator voltage, and no stator current controllers are used. With the DTC method very good torque dynamics can be achieved. Until now, DTC has been applied to asynchronous motor drives. The purpose of this work is to analyse the applicability of DTC to electrically excited synchronous motor drives. Compared with asynchronous motor drives, electrically excited synchronous motor drives require an additional control for the rotor field current. The field current control is called excitation control in this study. The dependence of the static and dynamic performance of DTC synchronous motor drives on the excitation control has been analysed and a straightforward excitation control method has been developed and tested. In the field weakening range the stator flux linkage modulus must be reduced in order to keep the electro motive force of the synchronous motor smaller than the stator voltage and in order to maintain a sufficient voltage reserve. The dynamic performance of the DTC synchronous motor drive depends on the stator flux linkage modulus. Another important factor for the dynamic performance in the field weakening range is the excitation control. The field weakening analysis considers both dependencies. A modified excitation control method, which maximises the dynamic performance in the field weakening range, has been developed. In synchronous motor drives the load angle must be kept in a stabile working area in order to avoid loss of synchronism. The traditional vector control methods allow to adjust the load angle of the synchronous motor directly by the stator current control. In the DTC synchronous motor drive the load angle is not a directly controllable variable, but it is formed freely according to the motor`s electromagnetic state and load. The load angle can be limited indirectly by limiting the torque

  8. Analysis and control of excitation, field weakening and stability in direct torque controlled electrically excited synchronous motor drives

    Energy Technology Data Exchange (ETDEWEB)

    Pyrhoenen, O.

    1998-12-31

    Direct torque control (DTC) is a new control method for rotating field electrical machines. DTC controls directly the motor stator flux linkage with the stator voltage, and no stator current controllers are used. With the DTC method very good torque dynamics can be achieved. Until now, DTC has been applied to asynchronous motor drives. The purpose of this work is to analyse the applicability of DTC to electrically excited synchronous motor drives. Compared with asynchronous motor drives, electrically excited synchronous motor drives require an additional control for the rotor field current. The field current control is called excitation control in this study. The dependence of the static and dynamic performance of DTC synchronous motor drives on the excitation control has been analysed and a straightforward excitation control method has been developed and tested. In the field weakening range the stator flux linkage modulus must be reduced in order to keep the electro motive force of the synchronous motor smaller than the stator voltage and in order to maintain a sufficient voltage reserve. The dynamic performance of the DTC synchronous motor drive depends on the stator flux linkage modulus. Another important factor for the dynamic performance in the field weakening range is the excitation control. The field weakening analysis considers both dependencies. A modified excitation control method, which maximises the dynamic performance in the field weakening range, has been developed. In synchronous motor drives the load angle must be kept in a stabile working area in order to avoid loss of synchronism. The traditional vector control methods allow to adjust the load angle of the synchronous motor directly by the stator current control. In the DTC synchronous motor drive the load angle is not a directly controllable variable, but it is formed freely according to the motor`s electromagnetic state and load. The load angle can be limited indirectly by limiting the torque

  9. Experimental Method for Characterizing Electrical Steel Sheets in the Normal Direction

    Directory of Open Access Journals (Sweden)

    Thierry Belgrand

    2010-10-01

    Full Text Available This paper proposes an experimental method to characterise magnetic laminations in the direction normal to the sheet plane. The principle, which is based on a static excitation to avoid planar eddy currents, is explained and specific test benches are proposed. Measurements of the flux density are made with a sensor moving in and out of an air-gap. A simple analytical model is derived in order to determine the permeability in the normal direction. The experimental results for grain oriented steel sheets are presented and a comparison is provided with values obtained from literature.

  10. Specific Intensity Direct Current (DC) Electric Field Improves Neural Stem Cell Migration and Enhances Differentiation towards βIII-Tubulin+ Neurons

    Science.gov (United States)

    Zhao, Huiping; Steiger, Amanda; Nohner, Mitch; Ye, Hui

    2015-01-01

    Control of stem cell migration and differentiation is vital for efficient stem cell therapy. Literature reporting electric field–guided migration and differentiation is emerging. However, it is unknown if a field that causes cell migration is also capable of guiding cell differentiation—and the mechanisms for these processes remain unclear. Here, we report that a 115 V/m direct current (DC) electric field can induce directional migration of neural precursor cells (NPCs). Whole cell patching revealed that the cell membrane depolarized in the electric field, and buffering of extracellular calcium via EGTA prevented cell migration under these conditions. Immunocytochemical staining indicated that the same electric intensity could also be used to enhance differentiation and increase the percentage of cell differentiation into neurons, but not astrocytes and oligodendrocytes. The results indicate that DC electric field of this specific intensity is capable of promoting cell directional migration and orchestrating functional differentiation, suggestively mediated by calcium influx during DC field exposure. PMID:26068466

  11. Assessing the Impact of Direct Experience on Individual Preferences and Attitudes for Electric Vehicles

    DEFF Research Database (Denmark)

    Jensen, Anders Fjendbo

    Over the last decades, several studies have focused on understanding what drives the demand for electric vehicles (EVs). However, EVs still face large difficulties in developing into a mass market product. It is now recognised that individuals make choices based on a mixture of strategies...... elasticity and the diffusion of the EV into the car market. In particular the thesis (1) proposes a methodology to collect adequate data on choices before and after respondents obtain real-life experience with EVs; (2) uses advanced hybrid choice models estimated jointly on the before and the after data......, and (iv) a number of statements to measure the attitudes of environmental concern, appreciation of car features, interest in technology, general opinions towards EVs and scepticism. The same survey was then repeated in wave 2. First, a SC experiment was built with orthogonal design and tested...

  12. Assesing the Impact of Direct Experience on Individual Preferences and Attitudes for Electric Vehicles

    DEFF Research Database (Denmark)

    Jensen, Anders Fjendbo

    Over the last decades, several studies have focused on understanding what drives the demand for electric vehicles (EVs). However, EVs still face large difficulties in developing into a mass market product. It is now recognised that individuals make choices based on a mixture of strategies...... elasticity and the diffusion of the EV into the car market. In particular the thesis (1) proposes a methodology to collect adequate data on choices before and after respondents obtain experience with EVs; (2) uses advanced hybrid choice models estimated jointly on the before and the after data to model...... of statements to measure the attitudes of environmental concern, appreciation of car features, interest in technology, general opinions towards EVs and scepticism. The same survey was then repeated in wave 2. First, a SC experiment was built with orthogonal design and tested with a sample of 369 individuals...

  13. In situ–Directed Growth of Organic Nanofibers and Nanoflakes: Electrical and Morphological Properties

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de; Madsen, Morten; Kjelstrup-Hansen, Jakob

    2010-01-01

    Organic nanostructures made from organic molecules such as para-hexaphenylene (p-6P) could form nanoscale components in future electronic and optoelectronic devices. However, the integration of such fragile nanostructures with the necessary interface circuitry such as metal electrodes for electri......Organic nanostructures made from organic molecules such as para-hexaphenylene (p-6P) could form nanoscale components in future electronic and optoelectronic devices. However, the integration of such fragile nanostructures with the necessary interface circuitry such as metal electrodes...... patterned by a combination of optical lithography and electron beam lithography. The dimensions of the gold electrodes strongly influence the morphology of the resulting structures leading to notably different electrical properties. The ability to control such nanofiber or nanoflake growth opens...... the possibility for large-scale optoelectronic device fabrication....

  14. Electric-field-induced extremely large change in resistance in graphene ferromagnets

    Science.gov (United States)

    Song, Yu

    2018-01-01

    A colossal magnetoresistance (˜100×10^3% ) and an extremely large magnetoresistance (˜1×10^6% ) have been previously explored in manganite perovskites and Dirac materials, respectively. However, the requirement of an extremely strong magnetic field (and an extremely low temperature) makes them not applicable for realistic devices. In this work, we propose a device that can generate even larger changes in resistance in a zero-magnetic field and at a high temperature. The device is composed of graphene under two strips of yttrium iron garnet (YIG), where two gate voltages are applied to cancel the heavy charge doping in the YIG-induced half-metallic ferromagnets. By calculations using the Landauer-Büttiker formalism, we demonstrate that, when a proper gate voltage is applied on the free ferromagnet, changes in resistance up to 305×10^6% (16×10^3% ) can be achieved at the liquid helium (nitrogen) temperature and in a zero magnetic field. We attribute such a remarkable effect to a gate-induced full-polarization reversal in the free ferromagnet, which results in a metal-state to insulator-state transition in the device. We also find that the proposed effect can be realized in devices using other magnetic insulators, such as EuO and EuS. Our work should be helpful for developing a realistic switching device that is energy saving and CMOS-technology compatible.

  15. Relativistic Néel-order fields induced by electrical current in antiferromagnets

    Czech Academy of Sciences Publication Activity Database

    Železný, Jakub; Gao, H.; Výborný, Karel; Zemen, Jan; Mašek, Jan; Manchon, A.; Wunderlich, Joerg; Sinova, Jairo; Jungwirth, Tomáš

    2014-01-01

    Roč. 113, č. 15 (2014), , "157201-1"-"157201-5" ISSN 0031-9007 R&D Projects: GA MŠk(CZ) LM2011026; GA ČR GB14-37427G EU Projects: European Commission(XE) 268066 - 0MSPIN Institutional support: RVO:68378271 Keywords : spintronics * antiferromagnets * current induced switching Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.512, year: 2014

  16. On the electric signal direction indicator for teh control of road traffic ...

    African Journals Online (AJOL)

    An electronic signal direction indicator (ESDI) for the control of road traffic has been designed, constructed and studied. The construction was done using 555 timer IC, a transistor-transistor logic compatible device that can operate in several modes as the major active element. The ESDI system circuit is reliable, satisfactorily ...

  17. Operant conditioning of rat navigation using electrical stimulation for directional cues and rewards.

    Science.gov (United States)

    Lee, Maan-Gee; Jun, Gayoung; Choi, Hyo-Soon; Jang, Hwan Soo; Bae, Yong Chul; Suk, Kyoungho; Jang, Il-Sung; Choi, Byung-Ju

    2010-07-01

    Operant conditioning is often used to train a desired behavior in an animal. The contingency between a specific behavior and a reward is required for successful training. Here, we compared the effectiveness of two different mazes for training turning behaviors in response to directional cues in Sprague-Dawley rats. Forty-three rats were implanted with electrodes into the medial forebrain bundle and the left and right somatosensory cortices for reward and cues. Among them, thirteen rats discriminated between the left and right somatosensory stimulations to obtain rewards. They were trained to learn ipsilateral turning response to the stimulation of the left or right somatosensory cortex in either the T-maze (Group T) or the E| maze (Group W). Performance was measured by the navigation speed in the mazes. Performances of rats in Group T were enhanced faster than those in Group W. A significant correlation between performances during training and performance in final testing was observed in Group T starting with the fifth training session while such a correlation was not observed in Group W until the tenth training session. The training mazes did not however affect the performances in the final test. These results suggest that a simple maze is better than a complicated maze for training animals to learn directions and direct cortical stimulation can be used as a cue for direction training. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  18. The effect of current direction on superconducting properties of BSCCO fibres grown by an electrically assisted laser floating zone process

    International Nuclear Information System (INIS)

    Carrasco, M F; Amaral, V S; Vieira, J M; Silva, R F; Costa, F M

    2006-01-01

    The application of an electric current of 200 mA through the molten zone of BSCCO superconducting fibres during laser floating zone processing constitutes an upgrade for improving the grain alignment. When a direct electric current (positively polarized fibre) passes through the solidification interface, the solidification conditions approach equilibrium, favouring the development of a higher amount of 2212 and 14/24 stable phases. The new electrically assisted laser floating zone (EALFZ) technique also improves the 2223 phase formation in fibres heat treated at high temperatures (860 deg. C). However, the 2223 crystals grow perpendicularly to the fibre axis at the interface between the 2212 and 14/24 phases, crossing the crystals of the main phase responsible for the current transport, cancelling the alignment effect. The resultant current density and critical temperature values were J c 77 K = 230 A cm -2 and T c = 85 K, respectively. When a lower heat treatment temperature was accomplished (820 deg. C), the 2223 transverse crystals do not develop and a higher current density value of J c 77 K = 510 A cm -2 was achieved, although with a critical temperature of T c = 90 K

  19. Synthesis and processing of materials for direct thermal-to-electric energy conversion and storage

    Science.gov (United States)

    Thompson, Travis

    Currently, fossil fuels are the primary source of energy. Mechanical heat engines convert the chemical potential energy in fossil fuels to useful electrical energy through combustion; a relatively low efficiency process that generates carbon dioxide. This practice has led to a significant increase in carbon dioxide emissions and is contributing to climate change. However, not all heat engines are mechanical. Alternative energy generation technologies to mechanical heat engines are known, yet underutilized. Thermoelectric generators are solid-state devices originally developed by NASA to power deep space spacecraft, which can also convert heat into electricity but without any moving parts. Similar to their mechanical counterparts, any heat source, including the burning of fossil fuels, can be used. However, clean heat sources, such as concentrated solar, can alternatively be used. Since the energy sources for many of the alternative energy technologies is intermittent, including concentrated solar for thermoelectric devices, load matching is difficult or impossible and an energy storage technology is needed in addition to the energy conversion technology. This increases the overall cost and complexity of the systems since two devices are required and represents a significant barrier for mass adoption of an alternative energy technology. However, it is possible to convert heat energy to electrical energy and store excess charge for use at a later time when the demand increases, in a single device. One such of a device is a thermogalvanic generator and is the electrochemical analog of electronic thermoelectric devices. Essentially, a thermogalvanic device represents the combination of thermoelectric and galvanic systems. As such, the rich history of strategies developed by both the thermoelectric community to better the performance of thermoelectric devices and by the electrochemical community to better traditional galvanic devices (i.e. batteries) can be applied to

  20. Development of electrical-erosion instrument for direct write micro-patterning on large area conductive thin films

    Energy Technology Data Exchange (ETDEWEB)

    Álvarez, Ángel Luis; Coya, Carmen; García-Vélez, Miguel [Departamento Teoría de la Señal y Comunicaciones, Sistemas Telemáticos y Computación, Escuela Técnica Superior de Ingeniería de Telecomunicación, Universidad Rey Juan Carlos, Fuenlabrada, Madrid 28943 (Spain)

    2015-08-15

    We have developed a complete instrument to perform direct, dry, and cost-effective lithography on conductive materials, based on localized electrical discharges, which avoids using masks or chemicals typical of conventional photolithography. The technique is considered fully compatible with substrate transport based systems, like roll-to-roll technology. The prototype is based on two piezo nano-steppers coupled to three linear micro-stages to cover a large scale operation from micrometers to centimeters. The operation mode consists of a spring probe biased at low DC voltage with respect to a grounded conductive layer. The tip slides on the target layer keeping contact with the material in room conditions, allowing continuous electric monitoring of the process, and also real-time tilt correction via software. The sliding tip leaves an insulating path (limited by the tip diameter) along the material, enabling to draw electrically insulated tracks and pads. The physical principle of operation is based in the natural self-limitation of the discharge due to material removal or insulation. The so produced electrical discharges are very fast, in the range of μs, so features may be performed at speeds of few cm/s, enabling scalability to large areas. The instrument has been tested on different conducting materials as gold, indium tin oxide, and aluminum, allowing the fabrication of alphanumeric displays based on passive matrix of organic light emitting diodes without the use of masks or photoresists. We have verified that the highest potential is achieved on graphene, where no waste material is detected, producing excellent well defined edges. This allows manufacturing graphene micro-ribbons with a high aspect ratio up to 1200:1.

  1. A domain-decomposition method to implement electrostatic free boundary conditions in the radial direction for electric discharges

    Science.gov (United States)

    Malagón-Romero, A.; Luque, A.

    2018-04-01

    At high pressure electric discharges typically grow as thin, elongated filaments. In a numerical simulation this large aspect ratio should ideally translate into a narrow, cylindrical computational domain that envelops the discharge as closely as possible. However, the development of the discharge is driven by electrostatic interactions and, if the computational domain is not wide enough, the boundary conditions imposed to the electrostatic potential on the external boundary have a strong effect on the discharge. Most numerical codes circumvent this problem by either using a wide computational domain or by calculating the boundary conditions by integrating the Green's function of an infinite domain. Here we describe an accurate and efficient method to impose free boundary conditions in the radial direction for an elongated electric discharge. To facilitate the use of our method we provide a sample implementation. Finally, we apply the method to solve Poisson's equation in cylindrical coordinates with free boundary conditions in both radial and longitudinal directions. This case is of particular interest for the initial stages of discharges in long gaps or natural discharges in the atmosphere, where it is not practical to extend the simulation volume to be bounded by two electrodes.

  2. Microbial surface displayed enzymes based biofuel cell utilizing degradation products of lignocellulosic biomass for direct electrical energy.

    Science.gov (United States)

    Fan, Shuqin; Hou, Chuantao; Liang, Bo; Feng, Ruirui; Liu, Aihua

    2015-09-01

    In this work, a bacterial surface displaying enzyme based two-compartment biofuel cell for the direct electrical energy conversion from degradation products of lignocellulosic biomass is reported. Considering that the main degradation products of the lignocellulose are glucose and xylose, xylose dehydrogenase (XDH) displayed bacteria (XDH-bacteria) and glucose dehydrogenase (GDH) displayed bacteria (GDH-bacteria) were used as anode catalysts in anode chamber with methylene blue as electron transfer mediator. While the cathode chamber was constructed with laccase/multi-walled-carbon nanotube/glassy-carbon-electrode. XDH-bacteria exhibited 1.75 times higher catalytic efficiency than GDH-bacteria. This assembled enzymatic fuel cell exhibited a high open-circuit potential of 0.80 V, acceptable stability and energy conversion efficiency. Moreover, the maximum power density of the cell could reach 53 μW cm(-2) when fueled with degradation products of corn stalk. Thus, this finding holds great potential to directly convert degradation products of biomass into electrical energy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. The Local Structure of Globalization. The Network Dynamics of Foreign Direct Investments in the International Electricity Industry

    Science.gov (United States)

    Koskinen, Johan; Lomi, Alessandro

    2013-05-01

    We study the evolution of the network of foreign direct investment (FDI) in the international electricity industry during the period 1994-2003. We assume that the ties in the network of investment relations between countries are created and deleted in continuous time, according to a conditional Gibbs distribution. This assumption allows us to take simultaneously into account the aggregate predictions of the well-established gravity model of international trade as well as local dependencies between network ties connecting the countries in our sample. According to the modified version of the gravity model that we specify, the probability of observing an investment tie between two countries depends on the mass of the economies involved, their physical distance, and the tendency of the network to self-organize into local configurations of network ties. While the limiting distribution of the data generating process is an exponential random graph model, we do not assume the system to be in equilibrium. We find evidence of the effects of the standard gravity model of international trade on evolution of the global FDI network. However, we also provide evidence of significant dyadic and extra-dyadic dependencies between investment ties that are typically ignored in available research. We show that local dependencies between national electricity industries are sufficient for explaining global properties of the network of foreign direct investments. We also show, however, that network dependencies vary significantly over time giving rise to a time-heterogeneous localized process of network evolution.

  4. A direct recursive residue generation method: application to photoionization of hydrogen in static electric fields

    International Nuclear Information System (INIS)

    Karlsson, H.O.; Goscinski, O.

    1994-01-01

    In studies of hydrogenic systems via the recursive residue generation method (RRGM) the major bottleneck is the matrix vector product HC, between the Hamiltonian matrix H and a Lanczos vector C. For highly excited states and/or strong perturbations the size of H grows fast leading to storage problems. By making use of direct methods, i.e. avoidance of explicit construction of large Hamiltonian matrices, such problems can be overcome. Utilizing the underlying analytical properties of the Laguerre basis e -λr L k 2l+2 (2λr) a direct RRGM (D-RRGM) for the unperturbed hydrogenic Hamiltonian is derived, changing the storage needs from scaling as N 2 to 4N where N is the number of radial functions for each factorized H o (l,m) block with the possibility of parallel processing. A further computational simplification is introduced by putting the expression for the photoionization (PI) cross section in the rational form conventionally used in the representation of density of states (DOS). This allows the construction of the PI cross section directly from the tridiagonal Lanczos matrix avoiding the explicit calculation of individual eigen values and eigenvectors. (Author)

  5. Transient Dynamics of Electric Power Systems: Direct Stability Assessment and Chaotic Motions

    Science.gov (United States)

    Chu, Chia-Chi

    A power system is continuously experiencing disturbances. Analyzing, predicting, and controlling transient dynamics, which describe transient behaviors of the power system following disturbances, is a major concern in the planning and operation of a power utility. Important conclusions and decisions are made based on the result of system transient behaviors. As today's power network becomes highly interconnected and much more complex, it has become essential to enhance the fundamental understanding of transient dynamics, and to develop fast and reliable computational algorithms. In this thesis, we emphasize mathematical rigor rather than physical insight. Nonlinear dynamical system theory is applied to study two fundamental topics: direct stability assessment and chaotic motions. Conventionally, power system stability is determined by calculating the time-domain transient behaviors for a given disturbance. In contrast, direct methods identify whether or not the system will remain stable once the disturbance is removed by comparing the corresponding energy value of the post-fault system to a calculated threshold value. Direct methods not only avoid the time-consuming numerical integration of the time domain approach, but also provide a quantitative measure of the degree of system stability. We present a general framework for the theoretical foundations of direct methods. Canonical representations of network-reduction models as well as network-preserving models are proposed to facilitate the analysis and the construction of energy functions of various power system models. An advanced and practical method, called the boundary of stability region based controlling unstable equilibrium point method (BCU method), of computing the controlling unstable equilibrium point is proposed along with its theoretical foundation. Numerical solution algorithms capable of supporting on-line applications of direct methods are provided. Further possible improvements and enhancements are

  6. Electrical limit of silver nanowire electrodes: Direct measurement of the nanowire junction resistance

    KAUST Repository

    Selzer, Franz; Floresca, Carlo; Kneppe, David; Bormann, Ludwig; Sachse, Christoph; Weiß , Nelli; Eychmü ller, Alexander; Amassian, Aram; Mü ller-Meskamp, Lars; Leo, Karl

    2016-01-01

    We measure basic network parameters of silvernanowire (AgNW) networks commonly used as transparent conductingelectrodes in organic optoelectronic devices. By means of four point probing with nanoprobes, the wire-to-wire junction resistance and the resistance of single nanowires are measured. The resistanceRNW of a single nanowire shows a value of RNW=(4.96±0.18) Ω/μm. The junction resistanceRJ differs for annealed and non-annealed NW networks, exhibiting values of RJ=(25.2±1.9) Ω (annealed) and RJ=(529±239) Ω (non-annealed), respectively. Our simulation achieves a good agreement between the measured network parameters and the sheet resistanceRS of the entire network. Extrapolating RJ to zero, our study show that we are close to the electrical limit of the conductivity of our AgNW system: We obtain a possible RS reduction by only ≈20% (common RS≈10 Ω/sq). Therefore, we expect further performance improvements in AgNW systems mainly by increasing NW length or by utilizing novel network geometries.

  7. Electrical limit of silver nanowire electrodes: Direct measurement of the nanowire junction resistance

    KAUST Repository

    Selzer, Franz

    2016-04-19

    We measure basic network parameters of silvernanowire (AgNW) networks commonly used as transparent conductingelectrodes in organic optoelectronic devices. By means of four point probing with nanoprobes, the wire-to-wire junction resistance and the resistance of single nanowires are measured. The resistanceRNW of a single nanowire shows a value of RNW=(4.96±0.18) Ω/μm. The junction resistanceRJ differs for annealed and non-annealed NW networks, exhibiting values of RJ=(25.2±1.9) Ω (annealed) and RJ=(529±239) Ω (non-annealed), respectively. Our simulation achieves a good agreement between the measured network parameters and the sheet resistanceRS of the entire network. Extrapolating RJ to zero, our study show that we are close to the electrical limit of the conductivity of our AgNW system: We obtain a possible RS reduction by only ≈20% (common RS≈10 Ω/sq). Therefore, we expect further performance improvements in AgNW systems mainly by increasing NW length or by utilizing novel network geometries.

  8. System Efficiency Improvement for Electric Vehicles Adopting a Permanent Magnet Synchronous Motor Direct Drive System

    Directory of Open Access Journals (Sweden)

    Chengming Zhang

    2017-12-01

    Full Text Available To improve the endurance mileage of electric vehicles (EVs, it is important to decrease the energy consumption of the Permanent Magnet Synchronous Motor (PMSM drive system. This paper proposes a novel loss optimization control strategy named system efficiency improvement control which can optimize both inverter and motor losses. A nonlinear power converter loss model is built to fit the nonlinear characteristics of power devices. This paper uses double Fourier integral analysis to analytically calculate the fundamental and harmonic components of motor current by which the fundamental motor loss and harmonic motor loss can be accurately analyzed. From these loss models, a whole-frequency-domain system loss model is derived and presented. Based on the system loss model, the system efficiency improvement control method applies the genetic algorithm to adjust the motor current and PWM frequency together to optimize the inverter and motor losses by which the system efficiency can be significantly improved without seriously influence on the system stability over the whole operation range of EVs. The optimal effects of system efficiency is verified by the experimental results in both Si-IGBT-based PMSM system and SiC-MOSFET-based system.

  9. Terahertz field-induced ionization and perturbed free induction decay of excitons in bulk GaAs

    Science.gov (United States)

    Murotani, Yuta; Takayama, Masayuki; Sekiguchi, Fumiya; Kim, Changsu; Akiyama, Hidefumi; Shimano, Ryo

    2018-03-01

    We investigated the interaction between an intense terahertz (THz) pulse and excitons in bulk GaAs by using THz pump near-infrared (NIR) optical probe spectroscopy. We observed a clear spectral oscillation in the NIR transient absorption spectra at low temperature, which is interpreted as the THz pump-induced perturbed free induction decay (PFID) of the excitonic interband polarization. We performed a numerical simulation based on a microscopic theory and identified that the observed PFID signal originates from the THz field-induced ionization of excitons. Using a real-space representation of the excitonic wave function, we visualized how the ionization of an exciton proceeds under the intense single-cycle THz electric field. We also calculated the nonlinear susceptibility with the lowest-order perturbation theory assuming a weak THz pump, which showed a similar spectral feature with that obtained by the full treatment to field-induced ionization process. This coincidence is attributed to the fact that 1s-excitonic interband polarization is modified predominantly through interactions with the p-wave component of the excitonic wave function. A simple phenomenological expression of the PFID signal is presented to discuss effects of the THz pump pulse duration on the spectral oscillation.

  10. Study on the Electric Conductivity of Ag-Doped DNA in Transverse Direction

    Directory of Open Access Journals (Sweden)

    Ban Ge

    2009-01-01

    Full Text Available Abstract In this article, we reported a novel experiment results on Ag-doped DNA conductor in transverse direction.I–Vcharacteristics were measured and the relative conductances were calculated for different silver ions concentrations. With the increase of the concentration of silver ions, the conductive ability of DNA risen rapidly, the relative conductance of DNA enhanced about three magnitudes and reached a stable value when Ag+concentration was up to 0.005 mM. In addition, Raman spectra were carried out to analyse and confirm conduction mechanism.

  11. Inhomogeneous field induced magnetoelectric effect in Mott insulators

    Energy Technology Data Exchange (ETDEWEB)

    Boulaevskii, Lev N [Los Alamos National Laboratory; Batista, Cristian D [Los Alamos National Laboratory

    2008-01-01

    We consider a Mott insulator like HoMnO{sub 3} whose magnetic lattice is geometrically frustrated and comprises a 3D array of triangular layers with magnetic moments ordered in a 120{sup o} structure. We show that the effect of a uniform magnetic field gradient, {gradient}H, is to redistribute the electronic charge of the magnetically ordered phase leading to a unfirom electric field gradient. The resulting voltage difference between the crystal edges is proportional to the square of the crystal thickness, or inter-edge distance, L. It can reach values of several volts for |{gradient}H| {approx} 0.01 T/cm and L {approx_equal} 1mm, as long as the crystal is free of antiferromagnetic domain walls.

  12. Electrical Power Supply to Offshore Oil Installations by High Voltage Direct Current Transmission

    Energy Technology Data Exchange (ETDEWEB)

    Myhre, Joergen Chr.

    2001-07-01

    This study was initiated to investigate if it could be feasible to supply offshore oil installations in the North Sea with electrical power from land. A prestudy of alternative converter topologies indicated that the most promising solution would be to investigate a conventional system with reduced synchronous compensator rating. The study starts with a summary of the state of power supply to offshore installations today, and a short review of classical HVDC transmission. It goes on to analyse how a passive network without sources influences the inverter. The transmission, with its current controlled rectifier and large inductance, is simulated as a current source. Under these circumstances the analysis shows that the network frequency has to adapt in order to keep the active and reactive power balance until the controllers are able to react. The concept of firing angle for a thyristor is limited in a system with variable frequency, the actual control parameter is the firing delay time. Sensitivity analysis showed some astonishing consequences. The frequency rises both by an increase in the active and in the reactive load. The voltage falls by an increase in the active load, but rises by an increase in the inductive load. Two different control principles for the system of inverter, synchronous compensator and load are defined. The first takes the reference for the firing delay time from the fundamental voltage at the point of common coupling. The second takes the reference for the firing delay time from the simulated EMF of the synchronous compensator. Of these, the second is the more stable and should be chosen as the basis for a possible control system. Two simulation tools are applied. The first is a quasi-phasor model running on Matlab with Simulink. The other is a time domain model in KREAN. The time domain model is primarily used for the verification of the quasi-phasor model, and shows that quasi-phasors is still a valuable tool for making a quick analysis

  13. Modelling the role of intrinsic electric fields in microtubules as an additional control mechanism of bi-directional intracellular transport.

    Science.gov (United States)

    Sataric, M V; Budinski-Petkovic, L; Loncarevic, I; Tuszynski, J A

    2008-01-01

    Active transport is essential for cellular function, while impaired transport has been linked to diseases such as neuronal degeneration. Much long distance transport in cells uses opposite polarity molecular motors of the kinesin and dynein families to move cargos along microtubules. It is clear that many types of cargo are moved by both sets of motors, and frequently in a reverse direction. The general question of how the direction of transport is regulated is still open. The mechanism of the cell's differential control of diverse cargos within the same cytoplasmic background is still unclear as is the answer to the question how endosomes and mitochondria move to different locations within the same cell. To answer these questions we postulate the existence of a local signaling mechanism used by the cell to specifically control different cargos. In particular, we propose an additional physical mechanism that works through the use of constant and alternating intrinsic (endogenous) electric fields as a means of controlling the speed and direction of microtubule-based transport. A specific model is proposed and analyzed in this paper. The model involves the rotational degrees of freedom of the C-termini of tubulin, their interactions and the coupling between elastic and dielectric degrees of freedom. Viscosity of the solution is also included and the resultant equation of motion is found as a nonlinear elliptic equation with dissipation. A particular analytical solution of this equation is obtained in the form of a kink whose properties are analyzed. It is concluded that this solution can be modulated by the presence of electric fields and hence may correspond to the observed behavior of motor protein transport along microtubules.

  14. Permanent magnetic field, direct electric field, and infrared to reduce blood glucose level and hepatic function in mus musculus with diabetic mellitus

    Science.gov (United States)

    Suhariningsih; Basuki Notobroto, Hari; Winarni, Dwi; Achmad Hussein, Saikhu; Anggono Prijo, Tri

    2017-05-01

    Blood contains several electrolytes with positive (cation) and negative (anion) ion load. Both electrolytes deliver impulse synergistically adjusting body needs. Those electrolytes give specific effect to external disturbance such as electric, magnetic, even infrared field. A study has been conducted to reduce blood glucose level and liver function, in type 2 Diabetes Mellitus patients, using Biophysics concept which uses combination therapy of permanent magnetic field, electric field, and infrared. This study used 48 healthy mice (mus musculus), male, age 3-4 weeks, with approximately 25-30 g in weight. Mice was fed with lard as high fat diet orally, before Streptozotocin (STZ) induction become diabetic mice. Therapy was conducted by putting mice in a chamber that emits the combination of permanent magnetic field, electric field, and infrared, every day for 1 hour for 28 days. There were 4 combinations of therapy/treatment, namely: (1) permanent magnetic field, direct electric field, and infrared; (2) permanent magnetic field, direct electric field, without infrared; (3) permanent magnetic field, alternating electric field, and infrared; and (4) permanent magnetic field, alternating electric field, without infrared. The results of therapy show that every combination is able to reduce blood glucose level, AST, and ALT. However, the best result is by using combination of permanent magnetic field, direct electric field, and infrared.

  15. Permanent magnetic field, direct electric field, and infrared to reduce blood glucose level and hepatic function in mus musculus with diabetic mellitus

    International Nuclear Information System (INIS)

    Suhariningsih; Prijo, Tri Anggono; Notobroto, Hari Basuki; Winarni, Dwi; Hussein, Saikhu Achmad

    2017-01-01

    Blood contains several electrolytes with positive (cation) and negative (anion) ion load. Both electrolytes deliver impulse synergistically adjusting body needs. Those electrolytes give specific effect to external disturbance such as electric, magnetic, even infrared field. A study has been conducted to reduce blood glucose level and liver function, in type 2 Diabetes Mellitus patients, using Biophysics concept which uses combination therapy of permanent magnetic field, electric field, and infrared. This study used 48 healthy mice ( mus musculus ), male, age 3-4 weeks, with approximately 25-30 g in weight. Mice was fed with lard as high fat diet orally, before Streptozotocin (STZ) induction become diabetic mice. Therapy was conducted by putting mice in a chamber that emits the combination of permanent magnetic field, electric field, and infrared, every day for 1 hour for 28 days. There were 4 combinations of therapy/treatment, namely: (1) permanent magnetic field, direct electric field, and infrared; (2) permanent magnetic field, direct electric field, without infrared; (3) permanent magnetic field, alternating electric field, and infrared; and (4) permanent magnetic field, alternating electric field, without infrared. The results of therapy show that every combination is able to reduce blood glucose level, AST, and ALT. However, the best result is by using combination of permanent magnetic field, direct electric field, and infrared. (paper)

  16. Study liquid length penetration results obtained with a direct acting piezo electric injector

    International Nuclear Information System (INIS)

    Payri, Raul; Gimeno, Jaime; Bardi, Michele; Plazas, Alejandro H.

    2013-01-01

    Highlights: ► A direct acting injector capable of controlling needle lift has been used to determine liquid phase penetration. ► The influence of injection pressure, chamber density and chamber temperature have been measured. ► When needle lift is reduced the stabilized liquid length is shortened. ► The relationship between needle lift and liquid length makes needle lift as a new way to control the injection event. - Abstract: A state of the art prototype common rail injector featuring direct control of the needle by means of a piezo stack (direct acting) has been tested. Liquid phase penetration of the sprays in diesel engine-like conditions has been studied via imaging technique in a novel continuous flow test chamber that allows an accurate control on a wide range of thermodynamic conditions (up to 1000 K and 15 MPa). This state of the art injector fitted with a 7-hole nozzle, allows a fully flexible control on the nozzle needle movement, enabling various fuel injection rate typologies. The temporal evolution of the seven sprays has been studied recording movies of the injection event in evaporative conditions via Mie scattering imaging technique and using a high speed camera. The results showed a strong influence of needle position on the stabilized liquid length while the effect of the injection pressure is negligible: the decrease of the needle lift causes a pressure drop in the needle seat and thus a reduction in the effective pressure upstream of the orifices (in the nozzle sac). According to known literature the stabilized liquid-length depends mainly on effective diameter, spray cone-angle and fuel/air properties and does not depend on fuel velocity at the orifice outlet. Therefore, due to small change in the spray cone-angle, higher injection pressures give slightly lower liquid length. However, partial needle lifts has an opposite effect: when needle is partially lifted a dramatic increase of the spray cone-angle and a consequent reduction of

  17. Demonstration of soft x-ray amplification by optical-field-induced ionization

    International Nuclear Information System (INIS)

    Midorikawa, Katsumi; Nagata, Yutaka; Kubodera, Shoichi; Obara, Minoru; Tashiro, Hideo; Toyoda, Koichi

    1995-01-01

    We have demonstrated the amplification of the 13.5-nm Lyman-α transition in hydrogen-like Li + ions, using a novel optical-field-induced ionization. A small-signal gain coefficient of 20 cm -1 was obtained. The use of preformed Li + plasma as an initial laser medium plays important roles for the production of suitable plasma conditions for an optical-field-induced ionization x-ray laser. (author)

  18. Comparison of Direct and Indirect Gas Reactor Brayton Systems for Nuclear Electric Space Propulsion

    International Nuclear Information System (INIS)

    M Postlehwait; P DiLorenzo; S Belanger; J Ashcroft

    2005-01-01

    Gas reactor systems are being considered as candidates for use in generating power for the Prometheus-1 spacecraft, along with other NASA missions as part of the Prometheus program. Gas reactors offer a benign coolant, which increases core and structural materials options. However, the gas coolant has inferior thermal transport properties, relative to other coolant candidates such as liquid metals. This leads to concerns for providing effective heat transfer and for minimizing pressure drop within the reactor core. In direct gas Brayton systems, i.e. those with one or more Brayton turbines in the reactor cooling loop, the ability to provide effective core cooling and low pressure drop is further constrained by the need for a low pressure, high molecular weight gas, typically a mixture of helium and xenon. Use of separate primary and secondary gas loops, one for the reactor and one or more for the Brayton system(s) separated by heat exchanger(s), allows for independent optimization of the pressure and gas composition of each loop. The reactor loop can use higher pressure pure helium, which provides improved heat transfer and heat transport properties, while the Brayton loop can utilize lower pressure He-Xe. However, this approach requires a separate primary gas circulator and also requires gas to gas heat exchangers. This paper focuses on the trade-offs between the direct gas reactor Brayton system and the indirect gas Brayton system. It discusses heat exchanger arrangement and materials options and projects heat exchanger mass based on heat transfer area and structural design needs. Analysis indicates that these heat exchangers add considerable mass, but result in reactor cooling and system resiliency improvements

  19. Effect of parallel electric fields on the whistler mode wave propagation in the magnetosphere

    International Nuclear Information System (INIS)

    Gupta, G.P.; Singh, R.N.

    1975-01-01

    The effect of parallel electric fields on whistler mode wave propagation has been studied. To account for the parallel electric fields, the dispersion equation has been analyzed, and refractive index surfaces for magnetospheric plasma have been constructed. The presence of parallel electric fields deforms the refractive index surfaces which diffuse the energy flow and produce defocusing of the whistler mode waves. The parallel electric field induces an instability in the whistler mode waves propagating through the magnetosphere. The growth or decay of whistler mode instability depends on the direction of parallel electric fields. It is concluded that the analyses of whistler wave records received on the ground should account for the role of parallel electric fields

  20. Effect of electrothermal annealing on the transformation behavior of TiNi shape memory alloy and two-way shape memory spring actuated by direct electrical current

    International Nuclear Information System (INIS)

    Wang, Z.G.; Zu, X.T.; Feng, X.D.; Zhu, S.; Deng, J.; Wang, L.M.

    2004-01-01

    In this work, the effect of electrothermal annealing on the transformation characterization of TiNi shape memory alloy and the electrothermal actuating characteristics of a two-way shape memory effect (TWSME) extension spring were investigated with direct electrical current. The results showed that with increasing direct electrical current density, the B2→R-phase transformation shifts to a lower temperature and R-phase→B19' shifts to a higher temperature in the cooling process. When annealing electrical current density reached 12.2 A/mm 2 , the R-phase disappeared and austenite transformed into martensite directly. The electrothermal annealing was an effective method of heat treatment in a selected part of shape memory alloy device. The electrothermal actuating characteristics of a TWSME spring showed that the time response and the maximum elongation greatly depended on the magnitude of the electrical current

  1. Phase-Shifted Eccentric Core Fiber Bragg Grating Fabricated by Electric Arc Discharge for Directional Bending Measurement.

    Science.gov (United States)

    Ouyang, Yang; Liu, Jianxia; Xu, Xiaofeng; Zhao, Yujia; Zhou, Ai

    2018-04-11

    A phase-shifted eccentric core fiber Bragg grating (PS-ECFBG) fabricated by electric arc discharge (EAD) is presented and demonstrated. It is composed of a fraction of eccentric core fiber fusion spliced in between two pieces of commercial single mode fibers, where a PS-FBG was written. The EAD in this work could flexibly change the amount of phase-shift by changing the discharge number or discharge duration. Because of the offset location of the eccentric core and the ultra-narrow resonant peak of the PS-ECFBG, it has a higher accuracy for measuring the directional bend. The elongation and compression of the eccentric core keep the magnitude of phase shift still unchanged during the bending process. The bending sensitivities of the PS-ECFBG at two opposite most sensitive directions are 57.4 pm/m -1 and -51.5 pm/m -1 , respectively. Besides, the PS-ECFBG has the potential to be a tunable narrow bandpass filter, which has a wider bi-directional adjustable range because of the bending responses. The strain and temperature sensitivities of the PS-ECFBG are experimentally measured as well, which are 0.70 pm/με and 8.85 pm/°C, respectively.

  2. Phase-Shifted Eccentric Core Fiber Bragg Grating Fabricated by Electric Arc Discharge for Directional Bending Measurement

    Directory of Open Access Journals (Sweden)

    Yang Ouyang

    2018-04-01

    Full Text Available A phase-shifted eccentric core fiber Bragg grating (PS-ECFBG fabricated by electric arc discharge (EAD is presented and demonstrated. It is composed of a fraction of eccentric core fiber fusion spliced in between two pieces of commercial single mode fibers, where a PS-FBG was written. The EAD in this work could flexibly change the amount of phase-shift by changing the discharge number or discharge duration. Because of the offset location of the eccentric core and the ultra-narrow resonant peak of the PS-ECFBG, it has a higher accuracy for measuring the directional bend. The elongation and compression of the eccentric core keep the magnitude of phase shift still unchanged during the bending process. The bending sensitivities of the PS-ECFBG at two opposite most sensitive directions are 57.4 pm/m−1 and −51.5 pm/m−1, respectively. Besides, the PS-ECFBG has the potential to be a tunable narrow bandpass filter, which has a wider bi-directional adjustable range because of the bending responses. The strain and temperature sensitivities of the PS-ECFBG are experimentally measured as well, which are 0.70 pm/με and 8.85 pm/°C, respectively.

  3. Comparison of the electrical and optical properties of direct current and radio frequency sputtered amorphous indium gallium zinc oxide films

    International Nuclear Information System (INIS)

    Yao, Jianke; Gong, Li; Xie, Lei; Zhang, Shengdong

    2013-01-01

    The electrical and optical properties of direct current and radio frequency (RF) sputtered amorphous indium gallium zinc oxide (a-IGZO) films are compared. It is found that the RF sputtered a-IGZO films have better stoichiometry (In:Ga:Zn:O = 1:1:1:2.5–3.0), lower electrical conductivity (σ < 8 S/cm), higher refractive index (n = 1.9–2.0) and larger band gap (E g = 3.02–3.29 eV), and show less shift of Fermi level (△ E F ∼ 0.26 eV) and increased concentration of electrons (△ N e ∼ 10 4 ) in the conduction band with the reduction concentration of oxygen vacancy (V O ). Although a-IGZO has intensively been studied for a semiconductor channel material of thin film transistors in next-generation flat panel displays, its fundamental material parameters have not been thoroughly reported. In this work, the work function (φ) of a-IGZO films is tested with the ultraviolet photoelectron spectroscopy. It is found that the φ of a-IGZO films is in the range of 4.0–5.0 eV depending on the V O . - Highlights: ► Amorphous InGaZnO 4 (a-IGZO) films were prepared with different sputtering modes. ► Electrical and optical properties of the different films were compared. ► Fermi level (△E F ) shift in a-IGZO films were tested by X-ray photoelectron spectroscopy. ► The relation of △E F with the properties of a-IGZO films were discussed. ► Work function was tested by ultraviolet photoelectron spectroscopy

  4. The green electricity market model. Proposal for an optional, cost-neutral direct marketing model for supplying electricity customers; Das Gruenstrommarktmodell. Vorschlag fuer ein optionales und kostenneutrales Direktvermarktungsmodell zur Versorgung von Stromkunden

    Energy Technology Data Exchange (ETDEWEB)

    Heinemann, Ronald [NATURSTROM AG, Berlin (Germany)

    2014-07-01

    One of the main goals of the Renewable Energy Law (EEG) is the market integration of renewable energy resources. For this purpose it has introduced compulsory direct marketing on the basis of a moving market premium. At the same time the green electricity privilege, a regulation which made it possible for customers to be supplied with electricity from EEG plants, has been abolished without substitution with effect from 1 August 2014. This means that, aside from other direct marketing channels, which will not be economically viable save for in a few exceptional cases, it will no longer be possible in future to sell electricity from EEG plants to electricity customers under the designation ''electricity from renewable energy''. The reason for this is that electricity sold under the market premium model can no longer justifiably be said to originate from renewable energy. As a consequence, almost all green electricity products sold in Germany carry a foreign green electricity certificate.

  5. Materials and design concerning magnetohydrodynamic channels of direct power conversion from combustion gases thermal energy into electricity

    International Nuclear Information System (INIS)

    Yerouchalmi, David

    1970-01-01

    Direct power conversion of thermal energy into electricity by magnetohydrodynamic is defined through thermodynamic cycles of hot gases; the present work concerning only the channel-generator operating with fossil gases in open cycle. Insulating walls and electrodes are subject initially to general apparent working conditions and those are followed by several others which appear only when experimental stage is reached. First, a choice has to be made between cold walls and hot walls which have been both closely investigated. But experience and theory lead to a third solution: viz controlled temperature walls and to consequent thermal exchange design. Many additional phenomena such as: solid state electrolysis, vaporisation, corrosion and alkali seed migration are analysed; then some solutions are described, tried and suggested. Same is given for mechanical, cooling devices, cold electric junctions and current relays. Experimental devices and work done on several solutions are described and results given. New prospects are suggested; and, in conclusion, the subject still appears to merit quite an important amount of further research. (author) [fr

  6. Energy-Regenerative Braking Control of Electric Vehicles Using Three-Phase Brushless Direct-Current Motors

    Directory of Open Access Journals (Sweden)

    Bo Long

    2013-12-01

    Full Text Available Regenerative braking provides an effective way of extending the driving range of battery powered electric vehicles (EVs. This paper analyzes the equivalent power circuit and operation principles of an EV using regenerative braking control technology. During the braking period, the switching sequence of the power converter is controlled to inverse the output torque of the three-phase brushless direct-current (DC motor, so that the braking energy can be returned to the battery. Compared with the presented methods, this technology can achieve several goals: energy recovery, electric braking, ultra-quiet braking and extending the driving range. Merits and drawbacks of different braking control strategy are further elaborated. State-space model of the EVs under energy-regenerative braking operation is established, considering that parameter variations are unavoidable due to temperature change, measured error, un-modeled dynamics, external disturbance and time-varying system parameters, a sliding mode robust controller (SMRC is designed and implemented. Phase current and DC-link voltage are selected as the state variables, respectively. The corresponding control law is also provided. The proposed control scheme is compared with a conventional proportional-integral (PI controller. A laboratory EV for experiment is setup to verify the proposed scheme. Experimental results show that the drive range of EVs can be improved about 17% using the proposed controller with energy-regeneration control.

  7. Investigating the functional neuroanatomy of concrete and abstract word processing through direct electric stimulation (DES) during awake surgery.

    Science.gov (United States)

    Orena, E F; Caldiroli, D; Acerbi, F; Barazzetta, I; Papagno, C

    2018-06-05

    Neuropsychological, neuroimaging and electrophysiological studies demonstrate that abstract and concrete word processing relies not only on the activity of a common bilateral network but also on dedicated networks. The neuropsychological literature has shown that a selective sparing of abstract relative to concrete words can be documented in lesions of the left anterior temporal regions. We investigated concrete and abstract word processing in 10 patients undergoing direct electrical stimulation (DES) for brain mapping during awake surgery in the left hemisphere. A lexical decision and a concreteness judgment task were added to the neuropsychological assessment during intra-operative monitoring. On the concreteness judgment, DES delivered over the inferior frontal gyrus significantly decreased abstract word accuracy while accuracy for concrete words decreased when the anterior temporal cortex was stimulated. These results are consistent with a lexical-semantic model that distinguishes between concrete and abstract words related to different neural substrates in the left hemisphere.

  8. Coordinated path-following and direct yaw-moment control of autonomous electric vehicles with sideslip angle estimation

    Science.gov (United States)

    Guo, Jinghua; Luo, Yugong; Li, Keqiang; Dai, Yifan

    2018-05-01

    This paper presents a novel coordinated path following system (PFS) and direct yaw-moment control (DYC) of autonomous electric vehicles via hierarchical control technique. In the high-level control law design, a new fuzzy factor is introduced based on the magnitude of longitudinal velocity of vehicle, a linear time varying (LTV)-based model predictive controller (MPC) is proposed to acquire the wheel steering angle and external yaw moment. Then, a pseudo inverse (PI) low-level control allocation law is designed to realize the tracking of desired external moment torque and management of the redundant tire actuators. Furthermore, the vehicle sideslip angle is estimated by the data fusion of low-cost GPS and INS, which can be obtained by the integral of modified INS signals with GPS signals as initial value. Finally, the effectiveness of the proposed control system is validated by the simulation and experimental tests.

  9. High efficiency direct thermal to electric energy conversion from radioisotope decay using selective emitters and spectrally tuned solar cells

    Science.gov (United States)

    Chubb, Donald L.; Flood, Dennis J.; Lowe, Roland A.

    1993-01-01

    Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1200K. Both selective emitter and filter system TPV systems are feasible. However, requirements on the filter system are severe in order to attain high efficiency. A thin-film of a rare-earth oxide is one method for producing an efficient, rugged selective emitter. An efficiency of 0.14 and power density of 9.2 W/KG at 1200K is calculated for a hypothetical thin-film neodymia (Nd2O3) selective emitter TPV system that uses radioisotope decay as the thermal energy source.

  10. High efficiency direct thermal to electric energy conversion from radioisotope decay using selective emitters and spectrally tuned solar cells

    International Nuclear Information System (INIS)

    Chubb, D.L.; Flood, D.J.; Lowe, R.A.

    1993-08-01

    Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1200K. Both selective emitter and filter system TPV systems are feasible. However, requirements on the filter system are severe in order to attain high efficiency. A thin-film of a rare-earth oxide is one method for producing an efficient, rugged selective emitter. An efficiency of 0.14 and power density of 9.2 W/KG at 1200K is calculated for a hypothetical thin-film neodymia (Nd2O3) selective emitter TPV system that uses radioisotope decay as the thermal energy source

  11. Second rank direction cosine spherical tensor operators and the nuclear electric quadrupole hyperfine structure Hamiltonian of rotating molecules

    Science.gov (United States)

    di Lauro, C.

    2018-03-01

    Transformations of vector or tensor properties from a space-fixed to a molecule-fixed axis system are often required in the study of rotating molecules. Spherical components λμ,ν of a first rank irreducible tensor can be obtained from the direction cosines between the two axis systems, and a second rank tensor with spherical components λμ,ν(2) can be built from the direct product λ × λ. It is shown that the treatment of the interaction between molecular rotation and the electric quadrupole of a nucleus is greatly simplified, if the coefficients in the axis-system transformation of the gradient of the electric field of the outer charges at the coupled nucleus are arranged as spherical components λμ,ν(2). Then the reduced matrix elements of the field gradient operators in a symmetric top eigenfunction basis, including their dependence on the molecule-fixed z-angular momentum component k, can be determined from the knowledge of those of λ(2) . The hyperfine structure Hamiltonian Hq is expressed as the sum of terms characterized each by a value of the molecule-fixed index ν, whose matrix elements obey the rule Δk = ν. Some of these terms may vanish because of molecular symmetry, and the specific cases of linear and symmetric top molecules, orthorhombic molecules, and molecules with symmetry lower than orthorhombic are considered. Each ν-term consists of a contraction of the rotational tensor λ(2) and the nuclear quadrupole tensor in the space-fixed frame, and its matrix elements in the rotation-nuclear spin coupled representation can be determined by the standard spherical tensor methods.

  12. Trial of Electrical Direct-Current Therapy versus Escitalopram for Depression.

    Science.gov (United States)

    Brunoni, Andre R; Moffa, Adriano H; Sampaio-Junior, Bernardo; Borrione, Lucas; Moreno, Marina L; Fernandes, Raquel A; Veronezi, Beatriz P; Nogueira, Barbara S; Aparicio, Luana V M; Razza, Lais B; Chamorro, Renan; Tort, Luara C; Fraguas, Renerio; Lotufo, Paulo A; Gattaz, Wagner F; Fregni, Felipe; Benseñor, Isabela M

    2017-06-29

    We compared transcranial direct-current stimulation (tDCS) with a selective serotonin-reuptake inhibitor for the treatment of depression. In a single-center, double-blind, noninferiority trial involving adults with unipolar depression, we randomly assigned patients to receive tDCS plus oral placebo, sham tDCS plus escitalopram, or sham tDCS plus oral placebo. The tDCS was administered in 30-minute, 2-mA prefrontal stimulation sessions for 15 consecutive weekdays, followed by 7 weekly treatments. Escitalopram was given at a dose of 10 mg per day for 3 weeks and 20 mg per day thereafter. The primary outcome measure was the change in the 17-item Hamilton Depression Rating Scale (HDRS-17) score (range, 0 to 52, with higher scores indicating more depression). Noninferiority of tDCS versus escitalopram was defined by a lower boundary of the confidence interval for the difference in the decreased score that was at least 50% of the difference in the scores with placebo versus escitalopram. A total of 245 patients underwent randomization, with 91 being assigned to escitalopram, 94 to tDCS, and 60 to placebo. In the intention-to-treat analysis, the mean (±SD) decrease in the score from baseline was 11.3±6.5 points in the escitalopram group, 9.0±7.1 points in the tDCS group, and 5.8±7.9 points in the placebo group. The lower boundary of the confidence interval for the difference in the decrease for tDCS versus escitalopram (difference, -2.3 points; 95% confidence interval [CI], -4.3 to -0.4; P=0.69) was lower than the noninferiority margin of -2.75 (50% of placebo minus escitalopram), so noninferiority could not be claimed. Escitalopram and tDCS were both superior to placebo (difference vs. placebo, 5.5 points [95% CI, 3.1 to 7.8; Pescitalopram had more frequent sleepiness and obstipation than did those in the other two groups. In a single-center trial, tDCS for the treatment of depression did not show noninferiority to escitalopram over a 10-week period and was

  13. A Comprehensive Study of Key Electric Vehicle (EV) Components, Technologies, Challenges, Impacts, and Future Direction of Development

    OpenAIRE

    Fuad Un-Noor; Sanjeevikumar Padmanaban; Lucian Mihet-Popa; Mohammad Nurunnabi Mollah; Eklas Hossain

    2017-01-01

    Electric vehicles (EV), including Battery Electric Vehicle (BEV), Hybrid Electric Vehicle (HEV), Plug-in Hybrid Electric Vehicle (PHEV), Fuel Cell Electric Vehicle (FCEV), are becoming more commonplace in the transportation sector in recent times. As the present trend suggests, this mode of transport is likely to replace internal combustion engine (ICE) vehicles in the near future. Each of the main EV components has a number of technologies that are currently in use or can become prominent in...

  14. The effect of magnetic field induced aggregates on ultrasound propagation in aqueous magnetic fluid

    International Nuclear Information System (INIS)

    Parekh, Kinnari; Upadhyay, R.V.

    2017-01-01

    Ultrasonic wave propagation in the aqueous magnetic fluid is investigated for different particle concentrations. The sound velocity decreases while acoustic impedance increases with increasing concentrations. The velocity anisotropy is observed upon application of magnetic field. The velocity anisotropy fits with Tarapov’s theory suggests the presence of aggregates in the system. We report that these aggregates are thermodynamically unstable and the length of aggregate changes continuously with increasing concentration and, or magnetic field and resulted in a decrease in effective magnetic moment. The Taketomi's theory fits well with the experimental data suggesting that the particle clusters are aligned in the direction of the magnetic field. The radius of cluster found to increase with increasing concentration, and then decreases whereas the elastic force constant increases and then becomes constant. The increase in cluster radius indicates elongation of aggregate length due to tip-to-tip interaction of aggregates whereas for higher concentration, the lateral alignment is more favorable than tip-to-tip alignment of aggregates which reduces the cluster radius making elastic force constant to raise. Optical images show that the chains are fluctuating and confirming the lateral alignment of chains at higher fields. - Highlights: • Magnetic field induced aggregates investigated using ultrasonic wave in aqueous magnetic fluid. • Velocity anisotropy induces upon applications of magnetic field. • Tarapov’s theory fit shows reduction in effective magnetic moment as concentration increases. • Taketomi's theory shows alignment of clusters in field direction. • Cluster radius increases and then decreases with increasing volume fractions. • Optical images show that fluctuating chains and lateral alignment of chains at higher fields.

  15. The effect of magnetic field induced aggregates on ultrasound propagation in aqueous magnetic fluid

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, Kinnari, E-mail: kinnariparekh.rnd@charusat.ac.in [Dr. KC Patel R& D Center, Charotar University of Science & Technology, Changa, 388421 Dist. Anand, Gujarat (India); Upadhyay, R.V. [PD Patel Institute of Applied Sciences, Charotar University of Science & Technology, Changa, 388421 Dist. Anand, Gujarat (India)

    2017-06-01

    Ultrasonic wave propagation in the aqueous magnetic fluid is investigated for different particle concentrations. The sound velocity decreases while acoustic impedance increases with increasing concentrations. The velocity anisotropy is observed upon application of magnetic field. The velocity anisotropy fits with Tarapov’s theory suggests the presence of aggregates in the system. We report that these aggregates are thermodynamically unstable and the length of aggregate changes continuously with increasing concentration and, or magnetic field and resulted in a decrease in effective magnetic moment. The Taketomi's theory fits well with the experimental data suggesting that the particle clusters are aligned in the direction of the magnetic field. The radius of cluster found to increase with increasing concentration, and then decreases whereas the elastic force constant increases and then becomes constant. The increase in cluster radius indicates elongation of aggregate length due to tip-to-tip interaction of aggregates whereas for higher concentration, the lateral alignment is more favorable than tip-to-tip alignment of aggregates which reduces the cluster radius making elastic force constant to raise. Optical images show that the chains are fluctuating and confirming the lateral alignment of chains at higher fields. - Highlights: • Magnetic field induced aggregates investigated using ultrasonic wave in aqueous magnetic fluid. • Velocity anisotropy induces upon applications of magnetic field. • Tarapov’s theory fit shows reduction in effective magnetic moment as concentration increases. • Taketomi's theory shows alignment of clusters in field direction. • Cluster radius increases and then decreases with increasing volume fractions. • Optical images show that fluctuating chains and lateral alignment of chains at higher fields.

  16. Can Lucifer Yellow Indicate Correct Permeability of Biological Cell Membrane under An Electric and Magnetic Field?

    OpenAIRE

    Tahereh Pourmirjafari Firoozabadi; Zeinab Shankayi; Azam Izadi; Seyed Mohammad Pourmirjafari Firoozabadi

    2015-01-01

    The effect of external magnetic and electric fields, in the range of electroporation and magnetoporation, on Lucifer Yellow (LY) fluorescence in the absence of cells is studied. Electric-field-induced quenching and magnetic field-induced increase are observed for fluorescence intensity of LY. Regard to the fact that the variation of field-induced fluorescence, even in the absence of cells, can be observed, the application of LY, as a marker, is debatable in electroporation and magnetoporation...

  17. Heterogeneous grain-scale response in ferroic polycrystals under electric field

    DEFF Research Database (Denmark)

    Daniels, John E.; Majkut, Marta; Cao, Qingua

    2016-01-01

    -ray diffraction (3D-XRD) is used to resolve the non-180° ferroelectric domain switching strain components of 191 grains from the bulk of a polycrystalline electro-ceramic that has undergone an electric-field-induced phase transformation. It is found that while the orientation of a given grain relative...... to the field direction has a significant influence on the phase and resultant domain texture, there are large deviations from the average behaviour at the grain scale. It is suggested that these deviations arise from local strain and electric field neighbourhoods being highly heterogeneous within the bulk...

  18. High magnetic field induced otolith fusion in the zebrafish larvae.

    Science.gov (United States)

    Pais-Roldán, Patricia; Singh, Ajeet Pratap; Schulz, Hildegard; Yu, Xin

    2016-04-11

    Magnetoreception in animals illustrates the interaction of biological systems with the geomagnetic field (geoMF). However, there are few studies that identified the impact of high magnetic field (MF) exposure from Magnetic Resonance Imaging (MRI) scanners (>100,000 times of geoMF) on specific biological targets. Here, we investigated the effects of a 14 Tesla MRI scanner on zebrafish larvae. All zebrafish larvae aligned parallel to the B0 field, i.e. the static MF, in the MRI scanner. The two otoliths (ear stones) in the otic vesicles of zebrafish larvae older than 24 hours post fertilization (hpf) fused together after the high MF exposure as short as 2 hours, yielding a single-otolith phenotype with aberrant swimming behavior. The otolith fusion was blocked in zebrafish larvae under anesthesia or embedded in agarose. Hair cells may play an important role on the MF-induced otolith fusion. This work provided direct evidence to show that high MF interacts with the otic vesicle of zebrafish larvae and causes otolith fusion in an "all-or-none" manner. The MF-induced otolith fusion may facilitate the searching for MF sensors using genetically amenable vertebrate animal models, such as zebrafish.

  19. Proposal for a magnetic field induced graphene dot

    International Nuclear Information System (INIS)

    Maksym, P A; Roy, M; Craciun, M F; Russo, S; Yamamoto, M; Tarucha, S; Aoki, H

    2010-01-01

    Quantum dots induced by a strong magnetic field applied to a single layer of graphene in the perpendicular direction are investigated. The dot is defined by a model potential which consists of a well of depth ΔV relative to a flat asymptotic part and quantum states formed from the zeroth Landau level are considered. The energy of the dot states cannot be lower than -ΔV relative to the asymptotic potential. Consequently, when ΔV is chosen to be about half of the gap between the zeroth and first Landau levels, the dot states are isolated energetically in the gap between Landau level 0 and Landau level -1. This is confirmed with numerical calculations of the magnetic field dependent energy spectrum and the quantum states. Remarkably, an antidot formed by reversing the sign of ΔV also confines electrons but in the energy region between Landau level 0 and Landau level +1. This unusual behaviour gives an unambiguous signal of the novel physics of graphene quantum dots.

  20. Electricity Theory

    International Nuclear Information System (INIS)

    Gong, Ha Soung

    2006-12-01

    The text book composed of five parts, which are summary of this book, arrangement of electricity theory including electricity nad magnetism, a direct current, and alternating current. It has two dictionary electricity terms for a synonym. The last is an appendix. It is for preparing for test of officer, electricity engineer and fire fighting engineer.

  1. Delineation of contaminant plume for an inorganic contaminated site using electrical resistivity tomography: comparison with direct-push technique.

    Science.gov (United States)

    Liao, Qing; Deng, Yaping; Shi, Xiaoqing; Sun, Yuanyuan; Duan, Weidong; Wu, Jichun

    2018-03-03

    Precise delineation of contaminant plume distribution is essential for effective remediation of contaminated sites. Traditional in situ investigation methods like direct-push (DP) sampling are accurate, but are usually intrusive and costly. Electrical resistivity tomography (ERT) method, as a non-invasive geophysical technique to map spatiotemporal changes in resistivity of the subsurface, is becoming increasingly popular in environmental science. However, the resolution of ERT for delineation of contaminant plumes still remains controversial. In this study, ERT and DP technique were both conducted at a real inorganic contaminated site. The reliability of the ERT method was validated by the direct comparisons of their investigation results that the resistivity acquired by ERT method is in accordance with the total dissolved solid concentration in groundwater and the overall variation of the total iron content in soil obtained by DP technique. After testifying the applicability of ERT method for contaminant identification, the extension of contaminant plume at the study site was revealed by supplementary ERT surveys conducted subsequently in the surrounding area of the contaminant source zone.

  2. Verification of ECMWF and ECMWF/MACC's global and direct irradiance forecasts with respect to solar electricity production forecasts

    Directory of Open Access Journals (Sweden)

    M. Schroedter-Homscheidt

    2017-02-01

    Full Text Available The successful electricity grid integration of solar energy into day-ahead markets requires at least hourly resolved 48 h forecasts. Technologies as photovoltaics and non-concentrating solar thermal technologies make use of global horizontal irradiance (GHI forecasts, while all concentrating technologies both from the photovoltaic and the thermal sector require direct normal irradiances (DNI. The European Centre for Medium-Range Weather Forecasts (ECMWF has recently changed towards providing direct as well as global irradiances. Additionally, the MACC (Monitoring Atmospheric Composition & Climate near-real time services provide daily analysis and forecasts of aerosol properties in preparation of the upcoming European Copernicus programme. The operational ECMWF/IFS (Integrated Forecast System forecast system will in the medium term profit from the Copernicus service aerosol forecasts. Therefore, within the MACC‑II project specific experiment runs were performed allowing for the assessment of the performance gain of these potential future capabilities. Also the potential impact of providing forecasts with hourly output resolution compared to three-hourly resolved forecasts is investigated. The inclusion of the new aerosol climatology in October 2003 improved both the GHI and DNI forecasts remarkably, while the change towards a new radiation scheme in 2007 only had minor and partly even unfavourable impacts on the performance indicators. For GHI, larger RMSE (root mean square error values are found for broken/overcast conditions than for scattered cloud fields. For DNI, the findings are opposite with larger RMSE values for scattered clouds compared to overcast/broken cloud situations. The introduction of direct irradiances as an output parameter in the operational IFS version has not resulted in a general performance improvement with respect to biases and RMSE compared to the widely used Skartveit et al. (1998 global to direct irradiance

  3. [Properties of NiTi wires with direct electric resistance heat treatment method in three-point bending tests].

    Science.gov (United States)

    Wang, Hong-mei; Wang, Bang-kang; Ren, Chao-chao; Bai, Yu-xing

    2011-03-01

    To investigate the mechanical properties of Ni-Ti wires with direct electric resistance heat treatment (DERHT) method in three-point bending tests. Two superelastic Ni-Ti wires (wire A: Smart SE, wire B: SENTALLOY SE, 0.406 mm × 0.559 mm) and 2 heat-actived Ni-Ti wires (wire C: Smart SM, wire D: L&H TITAN, 0.406 mm × 0.559 mm) were selected. They were heat-treated using the DERHT method by a controlled electric current (6.36 A) applied for different period of time [0 (control), 1.0, 1.5, 2.0, 2.5 seconds). Then, a three-point bending test was performed under controlled temperature (37°C) to examine the relationships between the deflection and the load in the bending of wires. After DERHT treatment, the plateau in the force-deflection curve of superelastic Ni-Ti wires and heat-activated Ni-Ti wires were increased. When the wires were heated for 2.0 seconds and deflected to 1.5 mm, the loading force of A, B, C and D Ni-Ti wires increased from (3.85 ± 0.11), (3.62 ± 0.07), (3.28 ± 0.09), (2.91 ± 0.23) N to (4.33 ± 0.07), (4.07 ± 0.05), (4.52 ± 0.08), (3.27 ± 0.15) N respectively. DERHT method is very convenient for clinical use. It is possible to change the arch form and superelastic force of NiTi wires. The longer the heating time is, the more the superelastic characteristics of the wires are altered.

  4. Hofstadter spectrum in electric and magnetic fields

    International Nuclear Information System (INIS)

    Kunold, Alejandro; Torres, Manuel

    2005-01-01

    The problem of Bloch electrons in two dimensions subjected to magnetic and intense electric fields is investigated. Magnetic translations, electric evolution, and energy translation operators are used to specify the solutions of the Schroedinger equation. For rational values of the magnetic flux quanta per unit cell and commensurate orientations of the electric field relative to the original lattice, an extended superlattice can be defined and a complete set of mutually commuting space-time symmetry operators is obtained. Dynamics of the system is governed by a finite difference equation that exactly includes the effects of: an arbitrary periodic potential, an electric field orientated in a commensurable direction of the lattice, and coupling between Landau levels. A weak periodic potential broadens each Landau level in a series of minibands, separated by the corresponding minigaps. The addition of the electric field induces a series of avoided and exact crossing of the quasienergies, for sufficiently strong electric field the spectrum evolves into equally spaced discreet levels, in this 'magnetic Stark ladder' the energy separation is an integer multiple of hE/aB, with a the lattice parameter

  5. Evidence of transcranial direct current stimulation-generated electric fields at subthalamic level in human brain in vivo.

    Science.gov (United States)

    Chhatbar, Pratik Y; Kautz, Steven A; Takacs, Istvan; Rowland, Nathan C; Revuelta, Gonzalo J; George, Mark S; Bikson, Marom; Feng, Wuwei

    2018-03-13

    Transcranial direct current stimulation (tDCS) is a promising brain modulation technique for several disease conditions. With this technique, some portion of the current penetrates through the scalp to the cortex and modulates cortical excitability, but a recent human cadaver study questions the amount. This insufficient intracerebral penetration of currents may partially explain the inconsistent and mixed results in tDCS studies to date. Experimental validation of a transcranial alternating current stimulation-generated electric field (EF) in vivo has been performed on the cortical (using electrocorticography, ECoG, electrodes), subcortical (using stereo electroencephalography, SEEG, electrodes) and deeper thalamic/subthalamic levels (using DBS electrodes). However, tDCS-generated EF measurements have never been attempted. We aimed to demonstrate that tDCS generates biologically relevant EF as deep as the subthalamic level in vivo. Patients with movement disorders who have implanted deep brain stimulation (DBS) electrodes serve as a natural experimental model for thalamic/subthalamic recordings of tDCS-generated EF. We measured voltage changes from DBS electrodes and body resistance from tDCS electrodes in three subjects while applying direct current to the scalp at 2 mA and 4 mA over two tDCS montages. Voltage changes at the level of deep nuclei changed proportionally with the level of applied current and varied with different tDCS montages. Our findings suggest that scalp-applied tDCS generates biologically relevant EF. Incorporation of these experimental results may improve finite element analysis (FEA)-based models. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Direct electric current treatment modifies mitochondrial function and lipid body content in the A549 cancer cell line.

    Science.gov (United States)

    Holandino, Carla; Teixeira, Cesar Augusto Antunes; de Oliveira, Felipe Alves Gomes; Barbosa, Gleyce Moreno; Siqueira, Camila Monteiro; Messeder, Douglas Jardim; de Aguiar, Fernanda Silva; da Veiga, Venicio Feo; Girard-Dias, Wendell; Miranda, Kildare; Galina, Antonio; Capella, Marcia Alves Marques; Morales, Marcelo Marcos

    2016-10-01

    Electrochemical therapy (EChT) entails treatment of solid tumors with direct electric current (DC). This work evaluated the specific effects of anodic flow generated by DC on biochemical and metabolic features of the A549 human lung cancer cell line. Apoptosis was evaluated on the basis of caspase-3 activity and mitochondrial transmembrane potential dissipation. Cell morphology was analyzed using transmission electron microscopy, and lipid droplets were studied through morphometric analysis and X-ray qualitative elemental microanalysis. High-resolution respirometry was used to assess mitochondrial respiratory parameters. Results indicated A549 viability decreased in a dose-dependent manner with a prominent drop between 18 and 24h after treatment (ppotential. Furthermore, treated cells demonstrated important ultrastructural mitochondria damage and a three-fold increase in the cytoplasmic lipid bodies' number, quantified by morphometrical analyses. Conversely, 24h after treatment, the cells presented a two-fold increase of residual oxygen consumption, accounting for 45.3% of basal oxygen consumption. These results show remarkable alterations promoted by anodic flow on human lung cancer cells which are possibly involved with the antitumoral effects of EChT. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Direct Determination of a Small-Molecule Drug, Valproic Acid, by an Electrically-Detected Microcantilever Biosensor for Personalized Diagnostics

    Directory of Open Access Journals (Sweden)

    Long-Sun Huang

    2015-01-01

    Full Text Available Direct, small-molecule determination of the antiepileptic drug, valproic acid, was investigated by a label-free, nanomechanical biosensor. Valproic acid has long been used as an antiepileptic medication, which is administered through therapeutic drug monitoring and has a narrow therapeutic dosage range of 50–100 μg·mL−1 in blood or serum. Unlike labeled and clinically-used measurement techniques, the label-free, electrical detection microcantilever biosensor can be miniaturized and simplified for use in portable or hand-held point-of-care platforms or personal diagnostic tools. A micromachined microcantilever sensor was packaged into the micro-channel of a fluidic system. The measurement of the antiepileptic drug, valproic acid, in phosphate-buffered saline and serum used a single free-standing, piezoresistive microcantilever biosensor in a thermally-controlled system. The measured surface stresses showed a profile over a concentration range of 50–500 μg·mL−1, which covered the clinically therapeutic range of 50–100 μg·mL−1. The estimated limit of detection (LOD was calculated to be 45 μg·mL−1, and the binding affinity between the drug and the antibody was measured at around 90 ± 21 μg·mL−1. Lastly, the results of the proposed device showed a similar profile in valproic acid drug detection with those of the clinically-used fluorescence polarization immunoassay.

  8. Gastric electrical stimulation decreases gastric distension-induced central nociception response through direct action on primary afferents.

    Directory of Open Access Journals (Sweden)

    Wassila Ouelaa

    Full Text Available BACKGROUND & AIMS: Gastric electrical stimulation (GES is an effective therapy to treat patients with chronic dyspepsia refractory to medical management. However, its mechanisms of action remain poorly understood. METHODS: Gastric pain was induced by performing gastric distension (GD in anesthetized rats. Pain response was monitored by measuring the pseudo-affective reflex (e.g., blood pressure variation, while neuronal activation was determined using c-fos immunochemistry in the central nervous system. Involvement of primary afferents was assessed by measuring phosphorylation of ERK1/2 in dorsal root ganglia. RESULTS: GES decreased blood pressure variation induced by GD, and prevented GD-induced neuronal activation in the dorsal horn of the spinal cord (T9-T10, the nucleus of the solitary tract and in CRF neurons of the hypothalamic paraventricular nucleus. This effect remained unaltered within the spinal cord when sectioning the medulla at the T5 level. Furthermore, GES prevented GD-induced phosphorylation of ERK1/2 in dorsal root ganglia. CONCLUSIONS: GES decreases GD-induced pain and/or discomfort likely through a direct modulation of gastric spinal afferents reducing central processing of visceral nociception.

  9. Overview of condition monitoring and operation control of electric power conversion systems in direct-drive wind turbines under faults

    Science.gov (United States)

    Huang, Shoudao; Wu, Xuan; Liu, Xiao; Gao, Jian; He, Yunze

    2017-09-01

    Electric power conversion system (EPCS), which consists of a generator and power converter, is one of the most important subsystems in a direct-drive wind turbine (DD-WT). However, this component accounts for the most failures (approximately 60% of the total number) in the entire DD-WT system according to statistical data. To improve the reliability of EPCSs and reduce the operation and maintenance cost of DD-WTs, numerous researchers have studied condition monitoring (CM) and fault diagnostics (FD). Numerous CM and FD techniques, which have respective advantages and disadvantages, have emerged. This paper provides an overview of the CM, FD, and operation control of EPCSs in DD-WTs under faults. After introducing the functional principle and structure of EPCS, this survey discusses the common failures in wind generators and power converters; briefly reviewed CM and FD methods and operation control of these generators and power converters under faults; and discussed the grid voltage faults related to EPCSs in DD-WTs. These theories and their related technical concepts are systematically discussed. Finally, predicted development trends are presented. The paper provides a valuable reference for developing service quality evaluation methods and fault operation control systems to achieve high-performance and high-intelligence DD-WTs.

  10. Direct electrical stimulation using a battery-operated device for induction and modulation of colonic contractions in pigs.

    Science.gov (United States)

    Bertschi, Mattia; Schlageter, Vincent; Vesin, Jean-Marc; Aellen, Steve; Peloponissios, Nicolas; D'Ambrogio, Aris; Wiesel, Paul Herman; Givel, Jean-Claude; Kucera, Pavel; Virag, Nathalie

    2010-07-01

    Direct electrical stimulation of the colon offers a promising approach for the induction of propulsive colonic contractions by using an implantable device. The objective of this study was to assess the feasibility to induce colonic contractions using a commercially available battery-operated stimulator (maximum pulse width of 1 ms and maximum amplitude of 10 V). Three pairs of pacing electrodes were inserted into the cecal seromuscular layer of anesthetized pigs. During a first set of in vivo experiments conducted on six animals, a pacing protocol leading to cecum contractions was determined: stimulation bursts with 1 ms pulse width, 10 V amplitude (7-15 mA), 120 Hz frequency, and 30-s burst duration, repeated every 2-5 min. In a second testing phase, an evaluation of the pacing protocol was performed in four animals (120 stimulation bursts in total). By using the battery-operated stimulator, contractions of the cecum and movement of contents could be induced in 92% of all stimulations. A cecal shortening of about 30% and an average intraluminal pressure increase of 10.0 +/- 6.0 mmHg were observed.

  11. High temperature thermal conductivity measurements of UO/sub 2/ by Direct Electrical Heating. Final report. [MANTRA-III

    Energy Technology Data Exchange (ETDEWEB)

    Bassett, B

    1980-10-01

    High temperature properties of reactor type UO/sub 2/ pellets were measured using a Direct Electrical Heating (DEH) Facility. Modifications to the experimental apparatus have been made so that successful and reproducible DEH runs may be carried out while protecting the pellets from oxidation at high temperature. X-ray diffraction measurements on the UO/sub 2/ pellets have been made before and after runs to assure that sample oxidation has not occurred. A computer code has been developed that will model the experiment using equations that describe physical properties of the material. This code allows these equations to be checked by comparing the model results to collected data. The thermal conductivity equation for UO/sub 2/ proposed by Weilbacher has been used for this analysis. By adjusting the empirical parameters in Weilbacher's equation, experimental data can be matched by the code. From the several runs analyzed, the resulting thermal conductivity equation is lambda = 1/4.79 + 0.0247T/ + 1.06 x 10/sup -3/ exp(-1.62/kT/) - 4410. exp(-3.71/kT/) where lambda is in w/cm K, k is the Boltzman constant, and T is the temperature in Kelvin.

  12. Analysis of closed orbit deviations for a first direct deuteron electric dipole moment measurement at the cooler synchrotron COSY

    Science.gov (United States)

    Schmidt, V.; Lehrach, A.

    2017-07-01

    The Jülich Electric Dipole moment Investigations (JEDI) collaboration in Julich is preparing a direct EDM measurement of protons and deuterons first at the storage ring COSY (COoler SYnchrotron) and later at a dedicated storage ring. Ensuring a precise measurement, various beam and spin manipulating effects have to be considered and investigated. A distortion of the closed orbit is one of the major sources for systematic uncertainties. Therefore misalignments of magnets and residual power supply oscillations are simulated using the MAD-X code in order to analyse their effect on the orbit. The underlying model for all simulations includes the dipoles, quadrupoles and sextupoles at COSY as well as the corrector magnets and BPMs (Beam Position Monitors). Since most sextupoles are only used during beam extraction, the sextupole strengths are set to zero resulting in a linear machine. The optics is adjusted in a way that the dispersion is zero in the straight sections. The closed orbit studies are performed for deuterons with a momentum of 970 MeV/c.

  13. Characterization of argon direct-current glow discharge with a longitudinal electric field applied at ambient air

    Science.gov (United States)

    Jiang, Weiman; Tang, Jie; Wang, Yishan; Zhao, Wei; Duan, Yixiang

    2014-09-01

    A direct-current-driven plasma jet is developed by applying a longitudinal electric field on the flowing argon at ambient air. This plasma shows a torch shape with its cross-section increased from the anode to the cathode. Comparison with its counterparts indicates that the gas flow plays a key role in variation of the plasma structure and contributes much to enlarging the plasma volume. It is also found that the circular hollow metal base promotes generation of plasma with a high-power volume density in a limited space. The optical emission spectroscopy (OES) diagnosis indicates that the plasma comprises many reactive species, such as OH, O, excited N2, and Ar metastables. Examination of the rotational and vibrational temperature indicates that the plasma is under nonequilibrium condition and the excited species OH(A 2Σ+), O(5P), and N2(C 3Πu) are partly generated by energy transfer from argon metastables. The spatially resolved OES of plasma reveals that the negative glow, Faraday dark space, and positive column are distributed across the gas gap. The absence of the anode glow is attributed to the fact that many electrons in the vicinity of the anode follow ions into the positive column due to the ambipolar diffusion in the flowing gas.

  14. Description of Self-efficacy and Initial Cognitive Abilities on the Students’ Physics Learning of the Direct Current Electrical Circuits

    Science.gov (United States)

    Zaenudin; Maknun, J.; Muslim

    2017-03-01

    This study aims to determine description of self -efficacy and initial cognitive abilities on the students of MAN 1 Bandung (senior high school) in learning physics on the subject of electrical circuits Direct Current (DC) before they get academy ask assigned in the classroom. From the results of this research can be used as a reference to provide appropriate measures for the advancement of student learning. The theory used in this research is the theory of Bandura. The design in this study using case study and data collection is done by tests and questionnaires, sampling techniques used by random sampling, the study was conducted on 10th grade students of MAN 1 Bandung by the amount of students 35 participants. The results of data analysis showed that the percentage of students who have moderate self-efficacy amounted to 67.05 %, and cognitive ability 50 %, this shows that the process of learning that takes place in school before that junior high school is not much scientific implement processes that provide students the opportunity to discover new things, then learning approaches of right is Problem Based Learning (PBL).

  15. Nanosize effects on the magnetic field induced transitions in La0.67−xEuxCa0.33MnO3 perovskite manganite

    International Nuclear Information System (INIS)

    Raju, N.; Roja Sree, D.; Reddy, S. Shravan Kumar; Reddy, Ch. Gopal; Reddy, P. Yadagiri; Reddy, K. Rama; Reddy, V. Raghavendra; Reddy Turpu, Goverdhan

    2014-01-01

    The nanosize effects on magnetic field induced transitions in La 0.67−x Eu x Ca 0.33 MnO 3 (x=0.25 and 0.27) system are presented in this paper. The reduction in the particle size of the system shows drastic effects on the electrical transport properties leading to robustness of the charge ordering phenomenon. The metal–insulator transition found in bulk materials at low magnetic fields disappeared in nanoparticles of the same material and a high field induced metal–insulator transition emerged at lower temperatures. These results manifest a strong correlation between the chemical pressures induced by doping of various ions at A-site and nanosize related phenomenon. - Highlights: • Chemical pressure and nanosize effects on electrical transport studies of Eu doped LCMO system are reported. • Decrease in particle size resulted in drastic changes on electrical transport studies. • Metal–insulator transition found in bulk at low magnetic fields disappeared in nanoparticles

  16. Cyclic electric field response of morphotropic Bi{sub 1/2}Na{sub 1/2}TiO{sub 3}-BaTiO{sub 3} piezoceramics

    Energy Technology Data Exchange (ETDEWEB)

    Hinterstein, M. [School of Materials Science and Engineering, UNSW Australia, 2052 Sydney (Australia); Institute for Applied Materials, Karlsruhe Institute of Technology, P.O. Box 3640, 76021 Karlsruhe (Germany); Schmitt, L. A. [Institute for Applied Materials, Karlsruhe Institute of Technology, P.O. Box 3640, 76021 Karlsruhe (Germany); Department of Materials and Geoscience, Technische Universität Darmstadt, 64287 Darmstadt (Germany); Hoelzel, M. [Heinz Maier Leibnitz Zentrum (MLZ), Technische Universität München, 85747 Garching (Germany); Jo, W. [School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Rödel, J.; Kleebe, H.-J. [Department of Materials and Geoscience, Technische Universität Darmstadt, 64287 Darmstadt (Germany); Hoffman, M. [School of Mechanical and Manufacturing Engineering, UNSW Australia, 2052 Sydney (Australia)

    2015-06-01

    In this study, the evolution of field induced mechanisms in lead-free piezoelectric ceramics (1−x)Bi{sub 1/2}Na{sub 1/2}TiO{sub 3}-xBaTiO{sub 3} with x = 0.06 and 0.07 was investigated by transmission electron microscopy, neutron, and X-ray diffraction. Preliminary investigations revealed a strong degradation of macroscopic electromechanical properties within the first 100 bipolar electric cycles. Therefore, this structural investigation focuses on a comparative diffraction study of freshly prepared, poled, and fatigued specimens. Transmission electron microscopy and neutron diffraction of the initial specimens reveal the coexistence of a rhombohedral and a tetragonal phase with space group R3c and P4bm, respectively. In situ electric field X-ray diffraction reveals a pronounced field induced phase transition from a pseudocubic state to a phase composition of significantly distorted phases upon poling with an external electric field of 4 kV/mm. Although the structures of the two compositions are pseudocubic and almost indistinguishable in the unpoled virgin state, the electric field response shows significant differences depending on composition. For both compositions, the application of an electric field results in a field induced phase transition in the direction of the minority phase. Electric cycling has an opposite effect on the phase composition and results in a decreased phase fraction of the minority phase in the fatigued remanent state at 0 kV/mm.

  17. The Electric Wind of Venus: A Global and Persistent Polar Wind -Like Ambipolar Electric Field Sufficient for the Direct Escape of Heavy Ionospheric Ions

    Science.gov (United States)

    Collinson, Glyn A.; Frahm, Rudy A.; Glocer, Alex; Coates, Andrew J.; Grebowsky, Joseph M.; Barabash, Stas; Domagal-Goldman, Shawn D.; Federov, Andrei; Futaana, Yoshifumi; Gilbert, Lin K.; hide

    2016-01-01

    Understanding what processes govern atmospheric escape and the loss of planetary water is of paramount importance for understanding how life in the universe can exist. One mechanism thought to be important at all planets is an ambipolar electric field that helps ions overcome gravity. We report the discovery and first quantitative extraterrestrial measurements of such a field at the planet Venus. Unexpectedly, despite comparable gravity, we show the field to be five times stronger than in Earths similar ionosphere. Contrary to our understanding, Venus would still lose heavy ions (including oxygen and all water-group species) to space, even if there were no stripping by the solar wind. We therefore find that it is possible for planets to lose heavy ions to space entirely through electric forces in their ionospheres and such an electric wind must be considered when studying the evolution and potential habitability of any planet in any star system.

  18. The discrepancy between human peripheral nerve chronaxie times as measured using magnetic and electric field stimuli: the relevance to MRI gradient coil safety

    International Nuclear Information System (INIS)

    Recoskie, Bryan J; Chronik, Blaine A; Scholl, Timothy J

    2009-01-01

    Peripheral nerve stimulation (PNS) resulting from electric fields induced from the rapidly changing magnetic fields of gradient coils is a concern in MRI. Nerves exposed to either electric fields or changing magnetic fields would be expected to display consistent threshold characteristics, motivating the direct application of electric field exposure criteria from the literature to guide the development of gradient magnetic field exposure criteria for MRI. The consistency of electric and magnetic field exposures was tested by comparing chronaxie times for electric and magnetic PNS curves for 22 healthy human subjects. Electric and magnetic stimulation thresholds were measured for exposure of the forearm using both surface electrodes and a figure-eight magnetic coil, respectively. The average chronaxie times for the electric and magnetic field conditions were 109 ± 11 μs and 651 ± 53 μs (±SE), respectively. We do not propose that these results call into question the basic mechanism, namely that rapidly switched gradient magnetic fields induce electric fields in human tissues, resulting in PNS. However, this result does motivate us to suggest that special care must be taken when using electric field exposure data from the literature to set gradient coil PNS safety standards in MRI.

  19. POTENTIAL FOR RARE EARTH ELEMENT RESOURCE EFFICIENCY IMPROVEMENTS IN PERMANENT MAGNET MOTORS THROUGH AN EXTENSION OF THE ELECTRIC MOTOR PRODUCT GROUP REGULATION UNDER THE EU ECODESIGN DIRECTIVE

    OpenAIRE

    Machacek, Erika; Dalhammar, Carl

    2013-01-01

    It has been proposed that the EU Ecodesign Directive can promote resource efficiency through relevant ecodesign requirements. This paper examines the potential for rare earth element (REE) resource efficiency improvements in the event the current regulation for electric motors under the Ecodesign Directive is to be extended to comprise REE-based permanent magnet motors. The research is based on literature studies, questionnaires and semi-structured interviews with representatives from industr...

  20. Structural and electrical properties of the GexSi1-x/Si heterojunctions obtained by the method of direct bonding

    International Nuclear Information System (INIS)

    Argunova, T. S.; Belyakova, E. I.; Grekhov, I. V.; Zabrodskii, A. G.; Kostina, L. S.; Sorokin, L. M.; Shmidt, N. M.; Yi, J. M.; Jung, J. W.; Je, J. H.; Abrosimov, N. V.

    2007-01-01

    The results of studying the structural and electrical properties of structures produced by the method of direct bonding of Ge x Si 1-x and Si wafers are reported. The wafers were cut from the crystals grown by the Czochralski method. Continuity of the interface and the crystal-lattice defects were studied by X-ray methods using synchrotron radiation and by scanning electron microscopy. Measurements of the forward and reverse current-voltage characteristics of the p-Ge x Si 1-x /n-Si diodes made it possible to assess the effect of the crystallattice defects on the electrical properties of heterojunctions. Satisfactory electrical parameters suggest that the technology of direct bonding is promising for the fabrication of large-area Ge x Si 1-x /Si heterojunctions

  1. Fluctuation-driven directional flow of energy in biochemical cycle: Electric activation of Na,K ATPase

    Science.gov (United States)

    Yow Tsong, Tian

    1998-03-01

    Na,K ATPase is an ion pump which uses chemical bond energy of ATP to pump Na ion out of, and K ion into living cell thus maintaining ionic and osmotic balances of the cell. Both are uphill transport reactions. Surprisingly we have found that electric energy can also substitute chemical energy to fuel the pump activity. However, in this case only electric fields of certain waveforms, amplitudes, and frequencies are effective. Waveform, amplitude and frequency are three elements of signal. In other words, Na,K ATPase can recognize, process, and harvest energy from an oscillating or a fluctuating electric field to drive an endergonic reaction. The enzyme is a molecular transducer of electric signal. This report will describe electric activation experiment to define electric signal. Electric signal will then mixed with electric noise of broad power spectrum for experiment. Effect of white noise (WN) on the efficiency of Na,K ATPase will be investigated. It will be shown that WN of appropriate power level can improve the pump efficiency when a sub-optimal electric field is used. WN can also carry a sub-threshold signal to cross over the threshold. Stochastic resonance will be discussed in reference to these observations.

  2. Numerical modeling of large field-induced strains in ferroelastic bodies: a continuum approach

    International Nuclear Information System (INIS)

    Raikher, Yu L; Stolbov, O V

    2008-01-01

    A consistent continuum model of a soft magnetic elastomer (SME) is presented and developed for the case of finite strain. The numeric algorithm enabling one to find the field-induced shape changes of an SME body is described. The reliability of the method is illustrated by several examples revealing specifics of the magnetostriction effect in SME samples of various geometries

  3. Advanced-fueled fusion reactors suitable for direct energy conversion. Project note: temperature-gradient enhancement of electrical fields in insulators

    International Nuclear Information System (INIS)

    Blum, A.S.; Mancebo, L.

    1976-01-01

    Direct energy converters for use on controlled fusion reactors utilize electrodes operated at elevated voltages and temperatures. The insulating elements that position these electrodes must support large voltages and under some circumstances large thermal gradients. It is shown that even modest thermal gradients can cause major alterations of the electric-field distribution within the insulating element

  4. Ion-beam-directed self-organization of conducting nanowire arrays

    International Nuclear Information System (INIS)

    Batzill, M.; Bardou, F.; Snowdon, K. J.

    2001-01-01

    Glancing-incidence ion-beam irradiation has been used both to ease kinetic constraints which otherwise restrict the establishment of long-range order and to impose external control on the orientation of nanowire arrays formed during stress-field-induced self-ordering of calcium atoms on a CaF 2 (111) surface. The arrays exhibit exceptional long-range order, with the long axis of the wires oriented along the azimuthal direction of ion-beam incidence. Transport measurements reveal a highly anisotropic electrical conductivity, whose maximum lies in the direction of the long axis of the 10.1-nm-period calcium wires

  5. Robust control of regenerative and hydraulic brakes for enhancing directional stability of an electric vehicle during straight-line braking

    NARCIS (Netherlands)

    Lv, Chen; Zhang, Junzhi; Li, Yutong; Zhao, Bolin; Yuan, Ye

    2016-01-01

    Thanks to the actuation flexibility of their systems, electric vehicles with individual powertrains, including in-wheel and on-board motors, are a very popular research topic amongst various types of electrified powertrain architectures. The introduction of the individual electric powertrain

  6. Shear- and magnetic-field-induced ordering in magnetic nanoparticle dispersion from small-angle neutron scattering

    International Nuclear Information System (INIS)

    Krishnamurthy, V.V.; Bhandar, A.S.; Piao, M.; Zoto, I.; Lane, A.M.; Nikles, D.E.; Wiest, J.M.; Mankey, G.J.; Porcar, L.; Glinka, C.J.

    2003-01-01

    Small-angle neutron scattering experiments have been performed to investigate orientational ordering of a dispersion of rod-shaped ferromagnetic nanoparticles under the influence of shear flow and static magnetic field. In this experiment, the flow and flow gradient directions are perpendicular to the direction of the applied magnetic field. The scattering intensity is isotropic in zero-shear-rate or zero-applied-field conditions, indicating that the particles are randomly oriented. Anisotropic scattering is observed both in a shear flow and in a static magnetic field, showing that both flow and field induce orientational order in the dispersion. The anisotropy increases with the increase of field and with the increase of shear rate. Three states of order have been observed with the application of both shear flow and magnetic field. At low shear rates, the particles are aligned in the field direction. When increasing shear rate is applied, the particles revert to random orientations at a characteristic shear rate that depends on the strength of the applied magnetic field. Above the characteristic shear rate, the particles align along the flow direction. The experimental results agree qualitatively with the predictions of a mean field model

  7. In-situ studies of stress- and magnetic-field-induced phase transformation in a polymer-bonded Ni-Co-Mn-In composite

    International Nuclear Information System (INIS)

    Liu, D.M.; Nie, Z.H.; Wang, G.; Wang, Y.D.; Brown, D.E.; Pearson, J.; Liaw, P.K.; Ren, Y.

    2010-01-01

    A polymer-bonded Ni 45 Co 5 Mn 36.6 In 13.4 ferromagnetic shape-memory composite was fabricated, having magnetic-field-driven shape recovery properties. The thermo-magnetization curves of the composite suggested that the magnetic-field-induced reverse martensitic transformation occurs in the composite. The effects of temperature, stress, and magnetic-field on the phase transformation properties were systematically investigated using an in-situ high-energy X-ray diffraction technique. A temperature-induced reversible martensitic phase transformation was confirmed within the composite, showing a broad phase transformation interval. Stress-induced highly textured martensite was observed in the composite during uniaxial compressive loading, with a residual strain after unloading. The origin of the textured martensite can be explained by the grain-orientation-dependent Bain distortion energy. A recovery strain of ∼1.76% along the compression direction was evidenced in the pre-strained composite with an applied magnetic-field of 5 T. This recovery was caused by the magnetic-field-induced reverse martensitic phase transformation. The phase transformation properties of the ferromagnetic shape-memory composite, different from its bulk alloys, can be well explained by the Clausius-Clapeyron relation. The large magnetic-field-induced strain, together with good ductility and low cost, make the polymer-bonded Ni-Co-Mn-In composites potential candidates for magnetic-field-driven actuators.

  8. Analysis of dynamic behavior of the back-to-back High Voltage Direct Current link model as part of electrical power system

    Directory of Open Access Journals (Sweden)

    Rudnik Vladimir

    2017-01-01

    Full Text Available One of the main directions of the development of electric power systems is the introduction of technologies based on high-power semiconductor switches, such as FACTS devices and HVDC technologies. These systems effectively solve a number of urgent tasks of EPS, connected with asynchronous connection of EPS, transmission of electricity, improve local and systemic flexibility and reliability of EPS, increasing the capacity of network elements that contains a “weak” connection. However, the implementation and operation of mentioned technologies in the EPS determines the need for a wide range of analysis and research that can only be done with the help of mathematical modeling.

  9. Metal/not metal joints: analysis of graphite junction for electric use of titanium by direct brazing with reactive alloy

    International Nuclear Information System (INIS)

    Guimaraes, A.S.; Rebello, J.M.A.

    1988-01-01

    The usual techniques of joining graphite (for electrical use) and titanium by brazing with zirconium alloys are described. The morphological and the chemical aspects obtained by X-ray diffraction analysis are also presented. (C.G.C.) [pt

  10. Electric Power Society in a new Situation - an Outline for an Actor Directed Strategy facing the Nuclear Power Phase Out

    International Nuclear Information System (INIS)

    1986-01-01

    A proposal is outlined implying the general electricity tax to be progressive in relation to the total power consumption. A level of 100-110 TWh is proposed as basis for the progressiveness. The tax curve will be levelled to yield an unchanged taxation today. The outline also involves a separate tax on condensing power production compensated by a reduction of the general electricity tax

  11. The Breakdown Mechanisms In Electrical Discharges: The Role Of The Field Emission Effect In Direct Current Discharges In Micro gaps

    International Nuclear Information System (INIS)

    Radmilovic-Radjenovic, M.; Radjenovic, B.; Bojarov, A.; Klas, M.; Matejcik, S.

    2013-01-01

    This review represents an attempt to sum up the current state of the research in the field of breakdown phenomena in electrical discharges. The paper provides facts and theories concerning different classes of direct current, radio and microwave frequency discharges, in vacuum, in the gas and in liquids, without and in the presence of the magnetic fields. The emphasize was made on the field emission effects and on the fundamental aspects of the breakdown phenomena in micro discharges via discussions and analysis of the experimental, theoretical and simulation results. It was found that the Paschen's law is not applicable for the micron gap sizes, when deviations from the standard scaling law become evident and modified Paschen curve should be used. The explanation of the deviations from the Paschen law was attributed to the secondary electron emission enhanced by the strong field generated in micro gaps. The experiments were carried out in order to establish scaling law in micro gaps. The volt-ampere characteristics were also recorded and compared with the theoretical predictions based on the Fowler-Nordheim theory. The importance of the enhancement factor and the space charge on results was also considered. On the basis of the experimental breakdown voltage curves, the effective yields in micro gaps have been estimated for different gases which can be served as input data in modeling. The effective yields allow analytically produce modified Paschen curves that predicts the deviations from the Paschen law observed in the experiments. In addition, we present results of computer simulations using a Particle-in-cell/Monte Carlo Collisions (PIC/MCC) code with the secondary emission model in order to include the field emission enhanced secondary electron production in micro gaps. The agreement between simulation and experimental results suggest that computer simulations can be used to improve understanding of the plasma physics as an alternative to analytical

  12. Current challenges of Germany’s energy transition project and competing strategies of challengers and incumbents: The case of direct marketing of electricity from renewable energy sources

    International Nuclear Information System (INIS)

    Wassermann, Sandra; Reeg, Matthias; Nienhaus, Kristina

    2015-01-01

    Electricity generated by renewable energies (RES-E) already accounts for 25% of Germany’s electricity supply. This has led to recent discussions for a better market integration of RES-E. The paper examines how competing actors and their ideas on market integration developed new services for direct marketing according to their respective origins and tried to shape the regulatory framework. The paper analyses this process and explains the current shape of the field of direct marketing. Medium-sized structured actors, who favoured RES-E integration via the conventional wholesale power markets, and who formed early close coalitions with RES-E power producers at the same time, have been most successful in terms of market shares. Moreover, they have been very successful for different reasons in building-up coalitions with governance units and influencing the field rules and routines. Based on those findings, the paper will conclude with some policy advices for the future adjustment of the current regulative frameworks. As long as there is no evidence of how RES-E can be integrated most effectively and efficiently, policies should maintain a competition between different direct marketing strategies to find out which strategies serve the best in terms of achieving a successful energy transition. - Highlights: • Innovation sociological analysis of the market integration of electricity from renewables in the German electricity markets. • Direct marketing of RES-E seen as a new strategic action field in the German “Energiewende”. • Strategies of incumbent and challenger actors to shape the rules of the field. • Suggestions for the future design of policy instruments for direct marketing of RES-E

  13. Direct evaluation of electrical dipole moment and oxygen density ratio at high-k dielectrics/SiO2 interface by X-ray photoelectron spectroscopy analysis

    Science.gov (United States)

    Fujimura, Nobuyuki; Ohta, Akio; Ikeda, Mitsuhisa; Makihara, Katsunori; Miyazaki, Seiichi

    2018-04-01

    The electrical dipole moment at an ultrathin high-k (HfO2, Al2O3, TiO2, Y2O3, and SrO)/SiO2 interface and its correlation with the oxygen density ratio at the interface have been directly evaluated by X-ray photoelectron spectroscopy (XPS) under monochromatized Al Kα radiation. The electrical dipole moment at the high-k/SiO2 interface has been measured from the change in the cut-off energy of secondary photoelectrons. Moreover, the oxygen density ratio at the interface between high-k and SiO2 has been estimated from cation core-line signals, such as Hf 4f, Al 2p, Y 3d, Ti 2p, Sr 3d, and Si 2p. We have experimentally clarified the relationship between the measured electrical dipole moment and the oxygen density ratio at the high-k/SiO2 interface.

  14. Innovative direct energy conversion systems from fusion output thermal power to the electrical one with the use of electronic adiabatic processes of electron fluid in solid conductors

    International Nuclear Information System (INIS)

    Kondoh, Y.; Kondo, M.; Shimoda, K.; Takahashi, T.; Osuga, K.

    2003-07-01

    It is shown that with the use of the fusion output and/or environmental thermal energy, innovative open systems for permanent auto-working (PA) direct energy converting (DEC) from the thermal to the electrical (TE) and further to the chemical potential (TEC) energies, abbreviated as PA-TEC-DEC systems, can be used for new auto-working electrical power plants and the plants of the compressible and conveyable hydrogen gas resources at various regions in the whole world. It is analytically shown that the same physical mechanism by free electrons and electrical potential determined by temperature in conductors, which include semiconductors, leads to the Peltier effect and the Seebeck one. It is analytically proved that the energy conservation law is exactly satisfied in a simple form where the net absorbed thermal power is directly transferred to the electrical power and to the chemical power in the PA-TEC-DEC systems. It is analytically and experimentally clarified that the long distance separation between two π type elements of the heat absorption side and the production one of the Peltier effect circuit system or between the higher temperature side and the lower one of the Seebeck effect circuit one does not change mechanisms of the heat pumping by the Peltier effect and of the TE-DEC by the Seebeck effect. The proposed systems gives us freedom of no using the fossil fuel, such as coals, oils, and natural gases that yield serious greenhouse effect all over the earth, and the plant of nuclear fissions that left radiating wastes, i.e., no more environmental pollutions. The PA-TEC-DEC systems can be applicable for several km scale systems to the micro ones, such as the plants of the electrical power and the hydrogen gas resources, compact transportable hydrogen gas producers, the refrigerators, the air conditions, home electrical apparatuses, and further the computer elements. (author)

  15. Microscopic observation of ferroelectric domains in SrTiO3 using birefringence imaging techniques under high electric fields

    International Nuclear Information System (INIS)

    Manaka, Hirotaka; Nozaki, Hirofumi; Miura, Yoko

    2017-01-01

    Phase transitions in SrTiO 3 between quantum paraelectric, coherent paraelectric, and electric-field-induced ferroelectric states are governed by tetragonal domains with quantum fluctuations. However, their characteristics are still unclear. To observe the electric-field-induced ferroelectric state using birefringence imaging techniques, we developed a suitable sample holder to apply high electric fields of up to E ≃ 5 kV/cm and temperatures down to T = 20 K. From birefringence imaging measurements of the ferroelectric LiNbO 3 with varying electric field, distributions of the electric field in the sample stage were found to be negligible. In SrTiO 3 , a huge-retardance area corresponding to the ferroelectric domains appears at E > 2 kV/cm and T ≤ 60 K even though the paraelectric domains partially remain. Furthermore, the fast-axis direction rotates by 90° at the ferroelectric phase transition because of an electrostrictive effect in ferroelectrics. The phase diagram of the critical electric field and temperature agrees with previous reports obtained from dielectric and neutron scattering measurements. (author)

  16. Field-induced cluster spin glass and inverse symmetry breaking enhanced by frustration

    Science.gov (United States)

    Schmidt, M.; Zimmer, F. M.; Magalhaes, S. G.

    2018-03-01

    We consider a cluster disordered model to study the interplay between short- and long-range interactions in geometrically frustrated spin systems under an external magnetic field (h). In our approach, the intercluster long-range disorder (J) is analytically treated to get an effective cluster model that is computed exactly. The clusters follow a checkerboard lattice with first-neighbor (J1) and second-neighbor (J2) interactions. We find a reentrant transition from the cluster spin-glass (CSG) state to a paramagnetic (PM) phase as the temperature decreases for a certain range of h. This inverse symmetry breaking (ISB) appears as a consequence of both quenched disorder with frustration and h, that introduce a CSG state with higher entropy than the polarized PM phase. The competitive scenario introduced by antiferromagnetic (AF) short-range interactions increases the CSG state entropy, leading to continuous ISB transitions and enhancing the ISB regions, mainly in the geometrically frustrated case (J1 =J2). Remarkably, when strong AF intracluster couplings are present, field-induced CSG phases can be found. These CSG regions are strongly related to the magnetization plateaus observed in this cluster disordered system. In fact, it is found that each field-induced magnetization jump brings a CSG region. We notice that geometrical frustration, as well as cluster size, play an important role in the magnetization plateaus and, therefore, are also relevant in the field-induced glassy states. Our findings suggest that competing interactions support ISB and field-induced CSG phases in disordered cluster systems under an external magnetic field.

  17. Magnetic-field induced phase transitions in intermetallic rare-earth ferrimagnets with a compensation point

    Czech Academy of Sciences Publication Activity Database

    Sabdenov, Ch.K.; Davydova, M.D.; Zvezdin, K.A.; Gorbunov, Denis; Tereshina, I. S.; Andreev, Alexander V.; Zvezdin, A. K.

    2017-01-01

    Roč. 43, č. 5 (2017), s. 551-558 ISSN 1063-777X R&D Projects: GA ČR GA16-03593S Institutional support: RVO:68378271 Keywords : rare-earth intermetallics * phase diagram * field-induced transition * magnetic anisotropy * high magnetic fields Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 0.804, year: 2016

  18. Directly connected series coupled HTPEM fuel cell stacks to a Li-ion battery DC bus for a fuel cell electrical vehicle

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Ashworth, Leanne; Remón, Ian Natanael

    2008-01-01

    The work presented in this paper examines the use of pure hydrogen fuelled high temperature polymer electrolyte membrane (HTPEM) fuel cell stacks in an electrical car, charging a Li-ion battery pack. The car is equipped with two branches of two series coupled 1 kW fuel cell stacks which...... are connected directly parallel to the battery pack during operation. This enables efficient charging of the batteries for increased driving range. With no power electronics used, the fuel cell stacks follow the battery pack voltage, and charge the batteries passively. This saves the electrical and economical...... losses related to these components and their added system complexity. The new car battery pack consists of 23 Li-ion battery cells and the charging and discharging are monitored by a battery management system (BMS) which ensures safe operating conditions for the batteries. The direct connection...

  19. State of the art and challenges in development of electrical contact materials in the light of the RoHS directive

    Directory of Open Access Journals (Sweden)

    Ćosović V.

    2012-01-01

    Full Text Available The article surveys current state of the art and challenges in the development of the electrical contact materials in the light of the EU Directive on Restriction of Hazardous Substances (RoHS. The focus was placed on widely used silver-cadmium alloys. According to this directive, as of July 1, 2006, use of six hazardous materials, including cadmium, are restricted for applicable electrical and electronic products intended for the EU market. In contrast, traditionally preferred material for production of electrical contacts is Ag-CdO, due to its outstanding functional properties. These conflicting interests result in present state where RoHS directive has not yet been implemented in its original form and has undergone numerous amendments and exceptions regarding the use of cadmium. Main reason for this seems to be the unrealistic time frame imposed by legislation. Although, significant effort has been put into research and development of alternative materials, there are still cases where adequate replacement materials had not been found. Therefore, importance of synchronicity between legislation and technological progress i.e. communication between legislative administration and industry and academia is brought to light as well as some common issues that may arise with an introduction of new replacement materials or product modification. [Projekat Ministarstva nauke Republike SRbije, br. OI 172037 and TR 34023

  20. Direct current electric potential in an anisotropic half-space with vertical contact containing a conductive 3D body

    Directory of Open Access Journals (Sweden)

    Li Ping

    2004-01-01

    Full Text Available Detailed studies of anomalous conductors in otherwise homogeneous media have been modelled. Vertical contacts form common geometries in galvanic studies when describing geological formations with different electrical conductivities on either side. However, previous studies of vertical discontinuities have been mainly concerned with isotropic environments. In this paper, we deal with the effect on the electric potentials, such as mise-à-la-masse anomalies, due to a conductor near a vertical contact between two anisotropic regions. We also demonstrate the interactive effects when the conductive body is placed across the vertical contact. This problem is normally very difficult to solve by the traditional numerical methods. The integral equations for the electric potential in anisotropic half-spaces are established. Green's function is obtained using the reflection and transmission image method in which five images are needed to fit the boundary conditions on the vertical interface and the air-earth surface. The effects of the anisotropy of the environments and the conductive body on the electric potential are illustrated with the aid of several numerical examples.

  1. Influence of direct reduced iron on the energy balance of the electric arc furnace in steel industry

    International Nuclear Information System (INIS)

    Kirschen, Marcus; Badr, Karim; Pfeifer, Herbert

    2011-01-01

    A model of the EAF energy efficiency was developed based on a closed mass and energy balance of the EAF melting process. This model was applied to industrial EAFs in steel industry charged with scrap or with mixes of scrap and DRI. Complex mass and energy conversion in the EAF was simplified with the introduction of mass and energy conversion efficiencies for the conversion of oxygen and the energy conversion of electrical energy in the electric arcs, chemical energy from the oxidation reactions in the melt and energy from the combustion of burner gas. It turned out that close agreement with observed process parameters from 16 EAFs is obtained by slight variations of the efficiency values. Especially the sensitivity of the steel temperature from the energy conversion efficiency of the electric arc energy indicates the importance of efficient foaming slag operation in EAF steel making. Characteristics and process parameters of DRI charged EAFs are discussed. Model results for a series of case studies illustrate the correlations between DRI chemical composition, DRI portion, oxygen consumption, etc. with electrical energy demand in order to indentify cost-effective EAF process conditions. -- Highlights: → Energy demand and carbon dioxide emission figures of EAF steelmaking processes based on steel scrap and DRI. → Complete energy balance of the EAF process using various input materials. → Application of the model to industrial EAF in steel industry in 4 case studies and discussion of model results. → Comparison with other models, critical discussion.

  2. The path to clean energy: direct coupling of nuclear and renewable technologies for thermal and electrical applications

    Energy Technology Data Exchange (ETDEWEB)

    Bragg-Sitton, Shannon [Idaho National Lab. (INL), Idaho Falls, ID (United States). Nuclear Fuel Performance and Design; Boardman, Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States). Advanced Process and Decision Systems; Ruth, Mark [National Renewable Energy Lab. (NREL), Golden, CO (United States). Strategic Energy Analysis Center

    2015-07-01

    The U.S. Department of Energy (DOE) recognizes the need to transform the energy infrastructure of the U.S. and elsewhere to systems that can significantly reduce environmental impacts in an efficient and economically viable manner while utilizing both clean energy generation sources and hydrocarbon resources. Thus, DOE is supporting research and development that could lead to more efficient utilization of clean nuclear and renewable energy generation sources. A concept being advanced by the DOE Offices of Nuclear Energy (NE) and Energy Efficiency and Renewable Energy (EERE) is tighter coupling of nuclear and renewable energy sources in a manner that better optimizes energy use for the combined electricity, industrial manufacturing, and the transportation sectors. This integration concept has been referred to as a “hybrid system” that is capable of providing energy (thermal or electrical) where it is needed, when it is needed. For the purposes of this work, the hybrid system would integrate two or more energy resources to generate two or more products, one of which must be an energy commodity, such as electricity or transportation fuel. This definition requires coupling of subsystems ‘‘behind’’ the electrical transmission bus, where energy flows are dynamically apportioned as necessary to meet demand and the system has a single connection to the grid that provides dispatchable electricity as required while capital intensive generation assets operate at full capacity. Development of integrated energy systems for an “energy park” must carefully consider the intended location and the associated regional resources, traditional industrial processes, energy delivery infrastructure, and markets to identify viable region-specific system configurations. This paper will provide an overview of the current status of regional hybrid energy system design, development and application of dynamic analysis tools to assess technical and economic performance, and

  3. The effect of applied electric field on pulsed radio frequency and pulsed direct current plasma jet array

    International Nuclear Information System (INIS)

    Hu, J. T.; Liu, X. Y.; Liu, J. H.; Xiong, Z. L.; Liu, D. W.; Lu, X. P.; Iza, F.; Kong, M. G.

    2012-01-01

    Here we compare the plasma plume propagation characteristics of a 3-channel pulsed RF plasma jet array and those of the same device operated by a pulsed dc source. For the pulsed-RF jet array, numerous long life time ions and metastables accumulated in the plasma channel make the plasma plume respond quickly to applied electric field. Its structure similar as “plasma bullet” is an anode glow indeed. For the pulsed dc plasma jet array, the strong electric field in the vicinity of the tube is the reason for the growing plasma bullet in the launching period. The repulsive forces between the growing plasma bullets result in the divergence of the pulsed dc plasma jet array. Finally, the comparison of 309 nm and 777 nm emissions between these two jet arrays suggests the high chemical activity of pulsed RF plasma jet array.

  4. Evaluation of local electric fields generated by transcranial direct current stimulation with an extracephalic reference electrode based on realistic 3D body modeling

    Science.gov (United States)

    Im, Chang-Hwan; Park, Ji-Hye; Shim, Miseon; Chang, Won Hyuk; Kim, Yun-Hee

    2012-04-01

    In this study, local electric field distributions generated by transcranial direct current stimulation (tDCS) with an extracephalic reference electrode were evaluated to address extracephalic tDCS safety issues. To this aim, we generated a numerical model of an adult male human upper body and applied the 3D finite element method to electric current conduction analysis. In our simulations, the active electrode was placed over the left primary motor cortex (M1) and the reference electrode was placed at six different locations: over the right temporal lobe, on the right supraorbital region, on the right deltoid, on the left deltoid, under the chin, and on the right buccinator muscle. The maximum current density and electric field intensity values in the brainstem generated by the extracephalic reference electrodes were comparable to, or even less than, those generated by the cephalic reference electrodes. These results suggest that extracephalic reference electrodes do not lead to unwanted modulation of the brainstem cardio-respiratory and autonomic centers, as indicated by recent experimental studies. The volume energy density was concentrated at the neck area by the use of deltoid reference electrodes, but was still smaller than that around the active electrode locations. In addition, the distributions of elicited cortical electric fields demonstrated that the use of extracephalic reference electrodes might allow for the robust prediction of cortical modulations with little dependence on the reference electrode locations.

  5. A Life Cycle Assessment Case Study of Coal-Fired Electricity Generation with Humidity Swing Direct Air Capture of CO2 versus MEA-Based Postcombustion Capture.

    Science.gov (United States)

    van der Giesen, Coen; Meinrenken, Christoph J; Kleijn, René; Sprecher, Benjamin; Lackner, Klaus S; Kramer, Gert Jan

    2017-01-17

    Most carbon capture and storage (CCS) envisions capturing CO 2 from flue gas. Direct air capture (DAC) of CO 2 has hitherto been deemed unviable because of the higher energy associated with capture at low atmospheric concentrations. We present a Life Cycle Assessment of coal-fired electricity generation that compares monoethanolamine (MEA)-based postcombustion capture (PCC) of CO 2 with distributed, humidity-swing-based direct air capture (HS-DAC). Given suitable temperature, humidity, wind, and water availability, HS-DAC can be largely passive. Comparing energy requirements of HS-DAC and MEA-PCC, we find that the parasitic load of HS-DAC is less than twice that of MEA-PCC (60-72 kJ/mol versus 33-46 kJ/mol, respectively). We also compare other environmental impacts as a function of net greenhouse gas (GHG) mitigation: To achieve the same 73% mitigation as MEA-PCC, HS-DAC would increase nine other environmental impacts by on average 38%, whereas MEA-PCC would increase them by 31%. Powering distributed HS-DAC with photovoltaics (instead of coal) while including recapture of all background GHG, reduces this increase to 18%, hypothetically enabling coal-based electricity with net-zero life-cycle GHG. We conclude that, in suitable geographies, HS-DAC can complement MEA-PCC to enable CO 2 capture independent of time and location of emissions and recapture background GHG from fossil-based electricity beyond flue stack emissions.

  6. Field-induced spin splitting and anomalous photoluminescence circular polarization in C H3N H3Pb I3 films at high magnetic field

    Science.gov (United States)

    Zhang, Chuang; Sun, Dali; Yu, Zhi-Gang; Sheng, Chuan-Xiang; McGill, Stephen; Semenov, Dmitry; Vardeny, Zeev Valy

    2018-04-01

    The organic-inorganic hybrid perovskites show excellent optical and electrical properties for photovoltaic and a myriad of other optoelectronics applications. Using high-field magneto-optical measurements up to 17.5 T at cryogenic temperatures, we have studied the spin-dependent optical transitions in the prototype C H3N H3Pb I3 , which are manifested in the field-induced circularly polarized photoluminescence emission. The energy splitting between left and right circularly polarized emission bands is measured to be ˜1.5 meV at 17.5 T, from which we obtained an exciton effective g factor of ˜1.32. Also from the photoluminescence diamagnetic shift we estimate the exciton binding energy to be ˜17 meV at low temperature. Surprisingly, the corresponding field-induced circular polarization is "anomalous" in that the photoluminescence emission of the higher split energy band is stronger than that of the lower split band. This "reversed" intensity ratio originates from the combination of long electron spin relaxation time and hole negative g factor in C H3N H3Pb I3 , which are in agreement with a model based on the k.p effective-mass approximation.

  7. Field Induced Magnetic Moments in a Metastable Iron-Mercury Alloy

    DEFF Research Database (Denmark)

    Pedersen, M.S.; Mørup, Steen; Linderoth, Søren

    1996-01-01

    The magnetic properties of a metastable iron-mercury alloy have been investigated in the temperature range from 5 to 200 K by Mossbauer spectroscopy and magnetization measurements. At low temperature the magnetic moment per iron atom is larger than af alpha-Fe. The effective spontaneous magnetic ....... It was found that the field-induced increase of the magnetic moment in the metastable iron-mecury alloy was about 0.06 Bohr magnetons per iron atom in the temperature range from 5 to 200 K for a field change from 6 to 12 T....

  8. Performance test of a vertically-directed electric-field cavity resonator made for the rapid gelation apparatus with microwave heating

    International Nuclear Information System (INIS)

    Yamagishi, Shigeru; Ogawa, Toru; Hasegawa, Atsushi.

    1996-06-01

    A cavity resonator with vertically-directed electric field was produced and attached to 'the rapid gelation apparatus with microwave heating' previously reported. Using the rapid gelation apparatus, drops of a simulated solution and of U-containing solutions for internal gelation were heated. The results indicated that the heating required for gelation of the U-containing solutions was possible. However, the electric field strength in the cavity resonator at that time was comparable to that causing the discharge due to the gaseous ammonia released from the heated drops. As a result, gel microspheres were not obtained in a stable state. The discussion suggests that the stable gelation would be realized by improving the cavity resonator shape and/or by modifying the power supply accompanied with using a power stabilizer. (author)

  9. 基于直接寻找法的电阻抗断层成像%Electrical Impedance Tomography Based on Direct Search Method

    Institute of Scientific and Technical Information of China (English)

    蔡畅; 严壮志

    2005-01-01

    Solution to impedance distribution in electrical impedance tomography (EIT) is an ill-posed nonlinear inverse problem. It is especially difficult to reconstruct an EIT image in the center area of a measured object. Tikhonov regularization with some prior information is a sound regularization method for static electrical impedance tomography under the condition that some true impedance distribution information is known a priori. This paper presents a direct search method (DSM) as pretreatment of image reconstruction through which one not only can construct a regularization matrix which maylocate in areas of impedance change, but also can obtain an initial impedance distribution more similar to the true impedance distribution, as well as better current modes which can better distinguish the initial distribution and the true distribution. Simulation results indicate that, by using DSM, resolution in the center area of the measured object can be improved significantly.

  10. Views of the electric utility industry on the direction and progress of the Department of Energy's Nuclear Waste Program

    International Nuclear Information System (INIS)

    Mills, L.E.

    1986-01-01

    The NWPA does provide guidance for a reasonable waste management program and one must work to implement it in an efficient and effective manner. It is well recognized that the lack of stability and predictability has been the bane of many nuclear reactor projects. The electric utilities are not satisfied with the progress of the nuclear waste program even though much has been achieved. DOE must continue in its struggle to seek a better balance between the technical, political and institutional aspects of the program to provide reasonable assurance that it will fulfill its contractual obligation with utilities

  11. A SOM clustering pattern sequence-based next symbol prediction method for day-ahead direct electricity load and price forecasting

    International Nuclear Information System (INIS)

    Jin, Cheng Hao; Pok, Gouchol; Lee, Yongmi; Park, Hyun-Woo; Kim, Kwang Deuk; Yun, Unil; Ryu, Keun Ho

    2015-01-01

    Highlights: • A novel pattern sequence-based direct time series forecasting method was proposed. • Due to the use of SOM’s topology preserving property, only SOM can be applied. • SCPSNSP only deals with the cluster patterns not each specific time series value. • SCPSNSP performs better than recently developed forecasting algorithms. - Abstract: In this paper, we propose a new day-ahead direct time series forecasting method for competitive electricity markets based on clustering and next symbol prediction. In the clustering step, pattern sequence and their topology relations are obtained from self organizing map time series clustering. In the next symbol prediction step, with each cluster label in the pattern sequence represented as a pair of its topologically identical coordinates, artificial neural network is used to predict the topological coordinates of next day by training the relationship between previous daily pattern sequence and its next day pattern. According to the obtained topology relations, the nearest nonzero hits pattern is assigned to next day so that the whole time series values can be directly forecasted from the assigned cluster pattern. The proposed method was evaluated on Spanish, Australian and New York electricity markets and compared with PSF and some of the most recently published forecasting methods. Experimental results show that the proposed method outperforms the best forecasting methods at least 3.64%

  12. The use of an axial flux permanent magnet in-wheel direct drive in an electric bicycle

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, P.R. [Norwegian University of Science and Technology, Trondheim (Norway). Dept. of Electrical Power Engineering; Patterson, D.; O' Keefe, C.; Swenson, J. [Northern Territory University, Darwin (Australia). NT Centre for Energy Research

    2001-03-01

    The research described in this paper concentrates on the development of an electronic converter. Successful completion of this converter provides the final component for the larger electric bicycle project. The controller developed for the bicycle is rated at 400 W and is hard-switched. It uses MOSFETs as power switching devices. There are three Hall effect sensors placed 120 electrical degrees apart from each other in the motor for velocity and position sensing. The torque generated by the machine is controlled by hysteresis band current control. In order for the motor/controller to be commercially viable, particular attention was paid to the costs of the controller. The result, an efficient yet cheap controller. Measurement of efficiency is difficult in high performance power electronic controllers (Patterson DJA very high efficiency controller for an axial flux permanent magnet wheel drive in a solar powered vehicle. 2nd IEEE International Conference on Power Electronics Drives and Energy Systems for Industrial Growth, IEEE PEDES '98, Perth, 30th November-3rd December, 1998). The paper includes discussion of a calorimetric method for measurement. (author)

  13. Innovative direct energy conversion systems using electronic adiabatic processes of electron fluid in solid conductors: new plants of electrical power and hydrogen gas resources without environmental pollutions

    International Nuclear Information System (INIS)

    Kondoh, Y.; Kondo, M.; Shimoda, K.; Takahashi, T.

    2001-07-01

    It is shown that using a novel recycling process of the environmental thermal energy, innovative permanent auto-working direct energy converter systems (PA-DEC systems) from the environmental thermal to electrical and/or chemical potential (TE/CP) energies, abbreviated as PA-TE/CP-DEC systems, can be used for new auto-working electrical power plants and the plants of the compressible and conveyable hydrogen gas resources at various regions in the whole world, with contributions to the world peace and the economical development in the south part of the world. It is shown that the same physical mechanism by free electrons and electrical potential determined by temperature in conductors, which include semiconductors, leads to the Peltier effect and the Seebeck one. It is experimentally clarified that the long distance separation between two π type elements of the heat absorption (HAS) and the production one (HPS) of the Peltier effect circuit system or between the higher temperature side (HTS) and the lower one (LTS) of the Seebeck effect circuit one does not change in the whole for the both effects. By using present systems, we do not need to use petrified fuels such as coals, oils, and natural gases in order to decrease the greenhouse effect by the CO 2 surrounding the earth. Furthermore, we do not need plats of nuclear fissions that left radiating wastes, i.e., with no environmental pollutions. The PA-TE/CP-DEC systems can be applicable for several km scale systems to the micro ones, such as the plants of the electrical power, the compact transportable hydrogen gas resources, a large heat energy container, which can be settled at far place from thermal energy absorbing area, the refrigerators, the air conditioners, home electrical apparatuses, and further the computer elements. It is shown that the simplest PA-TE/CP-DEC system can be established by using only the Seebeck effect components and the resolving water ones. It is clarified that the externally applied

  14. The TELEC - A plasma type of direct energy converter. [Thermo-Electronic Laser Energy Converter for electric power generation

    Science.gov (United States)

    Britt, E. J.

    1978-01-01

    The Thermo-Electronic Laser Energy Converter (TELEC) is a high-power density plasma device designed to convert a 10.6-micron CO2 laser beam into electric power. Electromagnetic radiation is absorbed in plasma electrons, creating a high-electron temperature. Energetic electrons diffuse from the plasma and strike two electrodes having different areas. The larger electrode collects more electrons and there is a net transport of current. An electromagnetic field is generated in the external circuit. A computer program has been designed to analyze TELEC performance allowing parametric variation for optimization. Values are presented for TELEC performance as a function of cesium pressure and for current density and efficiency as a function of output voltage. Efficiency is shown to increase with pressure, reaching a maximum over 45%.

  15. Electrical Structure of Future Off-shore Wind Power Plant with a High Voltage Direct Current Power Transmission

    DEFF Research Database (Denmark)

    Sharma, Ranjan

    The increasing demand of electric power and the growing consciousness towards the changing climate has led to a rapid development of renewable energy in the recent years. Among all, wind energy has been the fastest growing energy source in the last decade. But the growing size of wind power plants......, better wind conditions at off-shore and the general demand to put them out of sight have all contributed to the installation of large wind power plants in off-shore condition. However, moving wind power plants far out in the off-shore comes with many associated problems. One of the main challenges...... is the transmission of power over long distance. Historically, the power transmission from off-shore wind power plants has been done via HVAC submarine cables. This provides a simple solution, but AC cables cannot be arbitrarily long. It is shown in the report that major issues with HVAC cable transmission system...

  16. Effects of alternating and direct electrical current application on the odontoblastic layer in human teeth : an in vitro study

    NARCIS (Netherlands)

    Alwas-Danowska, HM; Huysmans, MCDNJM; Verdonschot, EH

    Aim The aim of this study was to investigate the influence of a low intensity alternating current on the odontoblasts and odontoblast layer and compare this with the effects of a direct current. Methodology Teeth extracted for orthodontic were immersed in physiological saline stabilized with thymol

  17. FOREIGN DIRECT INVESTMENT IN POST-CONFLICT COUNTRIES: THE CASE OF IRAQ’S OIL AND ELECTRICITY SECTORS

    Directory of Open Access Journals (Sweden)

    Ghassan Faraj Hanna

    2014-04-01

    Full Text Available Foreign direct investment is new phenomenon to Iraq, a post conflict country with abundance of natural resources. With dominant state-controlled public sector, attracting foreign investment is an added challenge to an economy devastated by years of wars. A qualitative case study was conducted to assess determinants of foreign direct investment in Iraq’s energy sector. Data was collected from interviews with business and government subject matter experts, and a review of publically available documents. Lack of security, political instability, corruption, and inadequate government policies towards foreign direct investment as symptoms found and typically shared by other post-conflict countries. The persistence of violence was not seen as a deterrent; however, foreign direct investment activity in the energy sector was virtually limited to the semi-autonomous region of Kurdistan. Investments were either wholly-owned or joint-venture enterprises. Implications to other post conflict countries, using Kuwait and Nigeria as illustrative examples, are presented and recommendations made.

  18. Electrohydrodynamics in nanochannels coated by mixed polymer brushes: effects of electric field strength and solvent quality

    Science.gov (United States)

    Cao, Qianqian; Tian, Xiu; You, Hao

    2018-04-01

    We examine the electrohydrodynamics in mixed polymer brush-coated nanochannels and the conformational dynamics of grafted polymers using molecular dynamics simulations. Charged (A) and neutral polymers (B) are alternately grafted on the channel surfaces. The effects of the electric field strength and solvent quality are addressed in detail. The dependence of electroosmotic flow characteristics and polymer conformational behavior on the solvent quality is influenced due to the change of the electric field strength. The enhanced electric field induces a collapse of the neutral polymer chains which adopt a highly extended conformation along the flow direction. However, the thickness of the charged polymer layer is affected weakly by the electric field, and even a slight swelling is identified for the A-B attraction case, implying the conformational coupling between two polymer species. Furthermore, the charged polymer chains incline entirely towards the electric field direction oppositely to the flow direction. More importantly, unlike the neutral polymer chains, the shape factor of the charged polymer chains, which is used to describe the overall shape of polymer chains, is reduced significantly with increasing the electric field strength, corresponding to a more coiled structure.

  19. Development of the apparatus for measuring magnetic properties of electrical steel sheets in arbitrary directions under compressive stress normal to their surface

    Directory of Open Access Journals (Sweden)

    Yoshitaka Maeda

    2017-05-01

    Full Text Available In designing motors, one must grasp the magnetic properties of electrical steel sheets considering actual conditions in motors. Especially important is grasping the stress dependence of magnetic power loss. This paper describes a newly developed apparatus to measure two-dimensional (2-D magnetic properties (properties under the arbitrary alternating and the rotating flux conditions of electrical steel sheets under compressive stress normal to the sheet surface. The apparatus has a 2-D magnetic excitation circuit to generate magnetic fields in arbitrary directions in the evaluation area. It also has a pressing unit to apply compressive stress normal to the sheet surface. During measurement, it is important to apply uniform stress throughout the evaluation area. Therefore, we have developed a new flux density sensor using needle probe method. It is composed of thin copper foils sputtered on electrical steel sheets. By using this sensor, the stress can be applied to the surface of the specimen without influence of this sensor. This paper described the details of newly developed apparatus with this sensor, and measurement results of iron loss by using are shown.

  20. Development of the apparatus for measuring magnetic properties of electrical steel sheets in arbitrary directions under compressive stress normal to their surface

    Science.gov (United States)

    Maeda, Yoshitaka; Urata, Shinya; Nakai, Hideo; Takeuchi, Yuuya; Yun, Kyyoul; Yanase, Shunji; Okazaki, Yasuo

    2017-05-01

    In designing motors, one must grasp the magnetic properties of electrical steel sheets considering actual conditions in motors. Especially important is grasping the stress dependence of magnetic power loss. This paper describes a newly developed apparatus to measure two-dimensional (2-D) magnetic properties (properties under the arbitrary alternating and the rotating flux conditions) of electrical steel sheets under compressive stress normal to the sheet surface. The apparatus has a 2-D magnetic excitation circuit to generate magnetic fields in arbitrary directions in the evaluation area. It also has a pressing unit to apply compressive stress normal to the sheet surface. During measurement, it is important to apply uniform stress throughout the evaluation area. Therefore, we have developed a new flux density sensor using needle probe method. It is composed of thin copper foils sputtered on electrical steel sheets. By using this sensor, the stress can be applied to the surface of the specimen without influence of this sensor. This paper described the details of newly developed apparatus with this sensor, and measurement results of iron loss by using are shown.

  1. Recurrent themes in the history of the home use of electrical stimulation: Transcranial direct current stimulation (tDCS) and the medical battery (1870-1920).

    Science.gov (United States)

    Wexler, Anna

    In recent years, neuroscientists and ethicists have warned of the dangers of the unsupervised home use of transcranial direct current stimulation (tDCS), in which individuals stimulate their own brains with low levels of electricity for self-improvement purposes. Although the home use of tDCS is often referred to as a novel phenomenon, in reality the late nineteenth and early twentieth century saw a proliferation of electrical stimulation devices for home use. In particular, the use of an object known as the medical battery bears a number of striking similarities to the modern-day use of tDCS. This article reviews a number of features thought to be unique to the present day home use of brain stimulation, with a particular focus on analogies between tDCS and the medical battery. Archival research was conducted at the Bakken Museum and at the American Medical Association's Historical Health Fraud Archives. Many of the features characterizing the contemporary home use tDCS-a do-it-yourself (DIY) movement, anti-medical establishment themes, conflicts between lay and professional usage-are a repetition of themes that occurred a century ago with regard to the medical battery. A number of features, however, seem to be unique to the present, such as the dominant discourse about risk and safety, the division between cranial and non-cranial stimulation, and utilization for cognitive enhancement purposes. Viewed in the long durée, the contemporary use of electrical stimulation at home is not a novel phenomenon, but rather the latest wave in a series of ongoing attempts by lay individuals to utilize electricity for therapeutic purposes. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Electrostatic interaction between an enzyme and electrodes in the electric double layer examined in a view of direct electron transfer-type bioelectrocatalysis.

    Science.gov (United States)

    Sugimoto, Yu; Kitazumi, Yuki; Tsujimura, Seiya; Shirai, Osamu; Yamamoto, Masahiro; Kano, Kenji

    2015-01-15

    Effects of the electrode poential on the activity of an adsorbed enzyme has been examined by using copper efflux oxidase (CueO) as a model enzyme and by monitoring direct electron transfer (DET)-type bioelectrocatalysis of oxygen reduction. CueO adsorbed on bare Au electrodes at around the point of zero charge (E(pzc)) shows the highest DET activity, and the activity decreases as the adsorption potential (E(ad); at which the enzyme adsorbs) is far from E(pzc). We propose a model to explain the phenomena in which the electrostatic interaction between the enzyme and electrodes in the electric double layer affects the orientation and the stability of the adsorbed enzyme. The self-assembled monolayer of butanethiol on Au electrodes decreases the electric field in the outside of the inner Helmholtz plane and drastically diminishes the E(ad) dependence of the DET activity of CueO. When CueO is adsorbed on bare Au electrodes under open circuit potential and then is held at hold potentials (E(ho)) more positive than E(pzc), the DET activity of the CueO rapidly decreases with the hold time. The strong electric field with positive surface charge density on the metallic electrode (σ(M)) leads to fatal denaturation of the adsorbed CueO. Such denaturation effect is not so serious at E(ho)electric field with negative σ(M) induces an orientation inconvenient for the DET reaction during the adsorption process. A positively charged neomycin shows a promoter ability to CueO adsorbed at E(ad)

  3. A parametric study of AC electric field-induced toroidal vortex formation in laminar nonpremixed coflow flames

    KAUST Repository

    Xiong, Yuan; Chung, Suk-Ho; Cha, Min

    2017-01-01

    in increased polycyclic aromatic hydrocarbon (PAH) formation, which promoted ITV formation. When judging the ITV-formation tendency based on critical applied voltage and frequency, it was qualitatively well correlated with the PAH concentration and the relative

  4. A proposed methodology for the calculation of direct consumption of fossil fuels and electricity for livestock breeding, and its application to Cyprus

    International Nuclear Information System (INIS)

    Kythreotou, Nicoletta; Florides, Georgios; Tassou, Savvas A.

    2012-01-01

    On-farm energy consumption is becoming increasingly important in the context of rising energy costs and concerns over greenhouse gas emissions. For farmers throughout the world, energy inputs represent a major and rapidly increasing cost. In many countries such as Cyprus, however, there is lack of systematic research on energy use in agriculture, which hinders benchmarking end evaluation of approaches and investment decisions for energy improvement. This study established a methodology for the estimation of the direct consumption of fossil fuels and electricity for livestock breeding, excluding transport, for locations where full data sets are not available. This methodology was then used to estimate fossil fuel and electricity consumption for livestock breeding in Cyprus. For 2008, this energy was found to be equivalent to 40.3 GWh that corresponds to 8% of the energy used in agriculture. Differences between the energy consumption per animal in Cyprus and other countries was found to be mainly due to differences in climatic conditions and technologies used in the farms. -- Highlights: ► A methodology to calculate energy consumption in farming applied to Cyprus. ► Annual consumption per animal was estimated to be 565 kWh/cow, 537 kWh/sow and 0.677 kWh/chicken. ► Direct energy consumption in livestock breeding is estimated at 40.3 GWh in 2008.

  5. Heisenberg spin-1/2 XXZ chain in the presence of electric and magnetic fields

    Science.gov (United States)

    Thakur, Pradeep; Durganandini, P.

    2018-02-01

    We study the interplay of electric and magnetic order in the one-dimensional Heisenberg spin-1/2 XXZ chain with large Ising anisotropy in the presence of the Dzyaloshinskii-Moriya (DM) interaction and with longitudinal and transverse magnetic fields, interpreting the DM interaction as a coupling between the local electric polarization and an external electric field. We obtain the ground state phase diagram using the density matrix renormalization group method and compute various ground state quantities like the magnetization, staggered magnetization, electric polarization and spin correlation functions, etc. In the presence of both longitudinal and transverse magnetic fields, there are three different phases corresponding to a gapped Néel phase with antiferromagnetic (AF) order, gapped saturated phase, and a critical incommensurate gapless phase. The external electric field modifies the phase boundaries but does not lead to any new phases. Both external magnetic fields and electric fields can be used to tune between the phases. We also show that the transverse magnetic field induces a vector chiral order in the Néel phase (even in the absence of an electric field) which can be interpreted as an electric polarization in a direction parallel to the AF order.

  6. Magnetic-field-induced Quantum Phase in S = 1/2 Frustrated Trellis Lattice

    Science.gov (United States)

    Yamaguchi, Hironori; Yoshizawa, Daichi; Kida, Takanori; Hagiwara, Masayuki; Matsuo, Akira; Kono, Yohei; Sakakibara, Toshiro; Tamekuni, Yusuke; Miyagai, Hirotsugu; Hosokoshi, Yuko

    2018-04-01

    We present a new model compound of an S = 1/2 frustrated system with ferromagnetic interaction composed of verdazyl radical β-2,3,5-Cl3-V. The ab initio molecular orbital calculation indicates the formation of an S = 1/2 trellis lattice in which zigzag chains and ladders with ferromagnetic rung interaction are two-dimensionally coupled. We observe a field-induced successive phase transition and an unconventional change in the magnetization curve near the saturation field, accompanied by T2 dependence on the magnetic specific heat. A two-dimensional spin-nematic state attributed to the ferromagnetic rung interactions is a possible candidate for the ground state in high-field regions.

  7. Effects of spin-polarized current on pulse field-induced precessional magnetization reversal

    Directory of Open Access Journals (Sweden)

    Guang-fu Zhang

    2012-12-01

    Full Text Available We investigate effects of a small DC spin-polarized current on the pulse field-induced precessional magnetization reversal in a thin elliptic magnetic element by micromagnetic simulations. We find that the spin-polarized current not only broadens the time window of the pulse duration, in which a successful precessional reversal is achievable, but also significantly suppresses the magnetization ringing after the reversal. The pulse time window as well as the decay rate of the ringing increase with increasing the current density. When a spin-polarized current with 5 MA/cm2 is applied, the time window increases from 80 ps to 112 ps, and the relaxation time of the ringing decreases from 1.1 ns to 0.32 ns. Our results provide useful information to achieve magnetic nanodevices based on precessional switching.

  8. Electromagnetic torque on the toroidal plasma and the error-field induced torque

    International Nuclear Information System (INIS)

    Pustovitov, V. D.

    2007-01-01

    The electromagnetic torque on the toroidal plasma is calculated assuming a linear plasma response to the applied perturbation, which may be the error field or the field created by the correction coils, or both. The result is compared with recently published expressions for the error field induced torque (Zheng et al 2006 Nucl. Fusion 46 L9, Zheng and Kotschenreuther 2006 Phys. Rev. Lett. 97 165001), and the conclusions of these papers are revised. We resolve the problem of the torque resonance raised there. It is shown that the strong increase in the torque due to the static error field must occur at the resistive wall mode stability limit and not at the no-wall stability limit

  9. Studying the universality of field induced tunnel ionization times via high-order harmonic spectroscopy

    International Nuclear Information System (INIS)

    Soifer, H; Bruner, B D; Dudovich, N; Negro, M; Devetta, M; Vozzi, C; Faccialà, D; Silvestri, S de; Stagira, S

    2014-01-01

    High-harmonic generation spectroscopy is a promising tool for resolving electron dynamics and structure in atomic and molecular systems. This scheme, commonly described by the strong field approximation, requires a deep insight into the basic mechanism that leads to the harmonic generation. Recently, we have demonstrated the ability to resolve the first stage of the process—field induced tunnel ionization—by adding a weak perturbation to the strong fundamental field. Here we generalize this approach and show that the assumptions behind the strong field approximation are valid over a wide range of tunnel ionization conditions. Performing a systematic study—modifying the fundamental wavelength, intensity and atomic system—we observed a good agreement with quantum path analysis over a range of Keldysh parameters. The generality of this scheme opens new perspectives in high harmonics spectroscopy, holding the potential of probing large, complex molecular systems. (paper)

  10. Field induced magnetic phase transition as a magnon Bose Einstein condensation

    Directory of Open Access Journals (Sweden)

    Teodora Radu et al

    2007-01-01

    Full Text Available We report specific heat, magnetocaloric effect and magnetization measurements on single crystals of the frustrated quasi-2D spin -½ antiferromagnet Cs2CuCl4 in the external magnetic field 0≤B≤12 T along a-axis and in the temperature range 0.03 K≤T≤6 K. Decreasing the applied magnetic field B from high fields leads to the closure of the field induced gap in the magnon spectrum at a critical field Bcsimeq8.44 T and a long-range incommensurate state below Bc. In the vicinity of Bc, the phase transition boundary is well described by the power law TN~(Bc-B1/phi with the measured critical exponent phisimeq1.5. These findings provide experimental evidence that the scaling law of the transition temperature TN can be described by the universality class of 3D Bose–Einstein condensation (BEC of magnons.

  11. An Analysis of Ripple and Error Fields Induced by a Blanket in the CFETR

    Science.gov (United States)

    Yu, Guanying; Liu, Xufeng; Liu, Songlin

    2016-10-01

    The Chinese Fusion Engineering Tokamak Reactor (CFETR) is an important intermediate device between ITER and DEMO. The Water Cooled Ceramic Breeder (WCCB) blanket whose structural material is mainly made of Reduced Activation Ferritic/Martensitic (RAFM) steel, is one of the candidate conceptual blanket design. An analysis of ripple and error field induced by RAFM steel in WCCB is evaluated with the method of static magnetic analysis in the ANSYS code. Significant additional magnetic field is produced by blanket and it leads to an increased ripple field. Maximum ripple along the separatrix line reaches 0.53% which is higher than 0.5% of the acceptable design value. Simultaneously, one blanket module is taken out for heating purpose and the resulting error field is calculated to be seriously against the requirement. supported by National Natural Science Foundation of China (No. 11175207) and the National Magnetic Confinement Fusion Program of China (No. 2013GB108004)

  12. Emission characteristics in solution-processed asymmetric white alternating current field-induced polymer electroluminescent devices

    Science.gov (United States)

    Chen, Yonghua; Xia, Yingdong; Smith, Gregory M.; Gu, Yu; Yang, Chuluo; Carroll, David L.

    2013-01-01

    In this work, the emission characteristics of a blue fluorophor poly(9, 9-dioctylfluorene) (PFO) combined with a red emitting dye: Bis(2-methyl-dibenzo[f,h]quinoxaline)(acetylacetonate)iridium (III) [Ir(MDQ)2(acac)], are examined in two different asymmetric white alternating current field-induced polymer electroluminescent (FIPEL) device structures. The first is a top-contact device in which the triplet transfer is observed resulting in the concentration-dependence of the emission similar to the standard organic light-emitting diode (OLED) structure. The second is a bottom-contact device which, however, exhibits concentration-independence of emission. Specifically, both dye emission and polymer emission are found for the concentrations as high as 10% by weight of the dye in the emitter. We attribute this to the significant different carrier injection characteristics of the two FIPEL devices. Our results suggest a simple and easy way to realize high-quality white emission.

  13. Temperature fields induced by direct contact condensation of steam in a cross-flow in a channel

    NARCIS (Netherlands)

    Clerx, N.; van Deurzen, L.G.M.; Pecenko, A.; Liew, R.; van der Geld, C.W.M.; Kuerten, Johannes G.M.

    2011-01-01

    The temperature fields in the center plane of a channel with a square cross-section have been measured. Steam injected at relatively low mass fluxes through a small hole in one of the walls of the channel condensed intermittently in a small area close to the inlet. The upstream temperature of the

  14. Field-induced exciton dissociation in PTB7-based organic solar cells

    Science.gov (United States)

    Gerhard, Marina; Arndt, Andreas P.; Bilal, Mühenad; Lemmer, Uli; Koch, Martin; Howard, Ian A.

    2017-05-01

    The physics of charge separation in organic semiconductors is a topic of ongoing research of relevance to material and device engineering. Herein, we present experimental observations of the field and temperature dependence of charge separation from singlet excitons in PTB7 and PC71BM , and from charge-transfer states created across interfaces in PTB 7 /PC71BM bulk heterojunction solar cells. We obtain this experimental data by time-resolving the near infrared emission of the states from 10 K to room temperature and electric fields from 0 to 2.5 MVcm -1 . Examining how the luminescence is quenched by field and temperature gives direct insight into the underlying physics. We observe that singlet excitons can be split by high fields, and that disorder broadens the high threshold fields needed to split the excitons. Charge-transfer (CT) states, on the other hand, can be separated by both field and temperature. Also, the data imply a strong reduction of the activation barrier for charge splitting from the CT state relative to the exciton state. The observations provided herein of the field-dependent separation of CT states as a function of temperature offer a rich data set against which theoretical models of charge separation can be rigorously tested; it should be useful for developing the more advanced theoretical models of charge separation.

  15. From research to production: field induced electro-mechanical polymer-transducer (Conference Presentation)

    Science.gov (United States)

    Kovacs, Gabor M.

    2017-04-01

    In the past decades the development of compliant dielectric materials, capable of storing high electric energy density, is the object of considerable research efforts for commercial applications. Compared to the widely used soft dielectrics as compliant insulators, only a small variety of commercially products based on dielectric polymer transducers are available on the market up to date. A whole bunch of research activities worldwide has created a lot of very useful knowledge; but many researchers have been faced to different obstacles to manufacture devices for demonstrations. However, building handy demonstrators is one of the most relevant action in order to attract the interest of decision makers of industrial companies. Moreover, low cost devices strictly require highly efficient production methods and facilities to become competitive on the market. This aspect contains the ultimate requirement especially for very high output rates and represents one of the major topic at most negotiations. All technological problems linked to this issue have been addressed only a little in the past R+D activities and are still widely not satisfactory solved. The present talk will provide an overview of the options for opening the door of industrial production of polymer transducers and the remaining obstacles to be solved for the next step. In particular, the most relevant actions to be taken for enabling high capacity production at very low cost will be discussed, which have an essential impact on the direction of future research activities.

  16. Electrohydrodynamic Direct-Write Orderly Micro/Nanofibrous Structure on Flexible Insulating Substrate

    Directory of Open Access Journals (Sweden)

    Jiang-Yi Zheng

    2014-01-01

    Full Text Available AC pulse-modulated electrohydrodynamic direct-writing (EDW was utilized to direct-write orderly micro/nanofibrous structure on the flexible insulating polyethylene terephthalate (PET substrate. During the EDW process, AC electrical field induced charges to reciprocate along the jet and decreased the charge repulsive force that applied on charged jet. Thanks to the smaller charge repulsive force, stable straight jet can be built up to direct-write orderly micro/nanofibrous structures on the insulating substrate. The minimum motion velocity required to direct-write straight line fibrous structure on insulating PET substrate was 700 mm/s. Moreover, the influences of AC voltage amplitude, frequency, and duty cycle ratio on the line width of fibrous structures were investigated. This work proposes a novel solution to overcome the inherent charge repulsion emerging on the insulating substrate, and promotes the application of EDW technology on the flexible electronics.

  17. Focal Electrically Administered Seizure Therapy (FEAST): A novel form of ECT illustrates the roles of current directionality, polarity, and electrode configuration in seizure induction

    Science.gov (United States)

    Spellman, Timothy; Peterchev, Angel V.; Lisanby, Sarah H.

    2009-01-01

    Electroconvulsive therapy (ECT) is a mainstay in the treatment of severe, medication resistant depression. The antidepressant efficacy and cognitive side effects of ECT are influenced by the position of the electrodes on the head and by the degree to which the electrical stimulus exceeds the threshold for seizure induction. However, surprisingly little is known about the effects of other key electrical parameters such as current directionality, polarity, and electrode configuration. Understanding these relationships may inform the optimization of therapeutic interventions to improve their risk/benefit ratio. To elucidate these relationships, we evaluated a novel form of ECT (focal electrically administered seizure therapy, FEAST) that combines unidirectional stimulation, control of polarity, and an asymmetrical electrode configuration, and contrasted it with conventional ECT in a nonhuman primate model. Rhesus monkeys had their seizure thresholds determined on separate days with ECT conditions that crossed the factors of current directionality (unidirectional or bidirectional), electrode configuration (standard bilateral or FEAST (small anterior and large posterior electrode)), and polarity (assignment of anode and cathode in unidirectional stimulation). Ictal expression and post-ictal suppression were quantified via scalp EEG. Findings were replicated and extended in a second experiment with the same subjects. Seizures were induced in each of 75 trials, including 42 FEAST procedures. Seizure thresholds were lower with unidirectional than with bidirectional stimulation (pFEAST than in bilateral ECS (p=0.0294). Ictal power was greatest in posterior-anode unidirectional FEAST, and post-ictal suppression was strongest in anterior-anode FEAST (p=0.0008 and p=0.0024, respectively). EEG power was higher in the stimulated hemisphere in posterior-anode FEAST (p=0.0246), consistent with the anode being the site of strongest activation. These findings suggest that current

  18. Integrated optical electric field sensor based on a Bragg grating in lithium niobate

    Science.gov (United States)

    Runde, D.; Brunken, S.; Rüter, C. E.; Kip, D.

    2007-01-01

    We demonstrate a new sensor concept for the measurement of oscillating electric fields that is based on Bragg gratings in LiNbO3:Ti channel waveguides. This miniaturized sensor that works in a retroreflective scheme does not require metallic electrodes and can be directly immersed in an oscillating electric field. The electric field induces a shift of the Bragg wavelength of the reflection grating that is due to the electro-optic effect. The operating point of the sensor is chosen by adjusting the laser wavelength to the slope of the spectral reflectivity function of the grating. In this way the magnitude of an external electric field is measured precisely as the amplitude of modulated reflected light intensity by using a lock-in amplifier. The sensor principle is demonstrated by detecting low-frequency electric fields ranging from 50 V/cm to 5 kV/cm without any conducting parts of the sensor head. Furthermore, the ability of the sensor to determine the three-dimensional orientation of an external electric field by a single rotation along the waveguide direction is demonstrated.

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

    Science.gov (United States)

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

    2016-12-01

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

  20. Electrical enhancement of direct methanol fuel cells by metal-plasma ion implantation Pt-Ru/C multilayer catalysts.

    Science.gov (United States)

    Weng, Ko-Wei; Chen, Yung-Lin; Chen, Ya-Chi; Lin, Tai-Nan

    2009-02-01

    Direct methanol fuel cells (DMFC) have been widely studied owing to their simple cell configuration, high volume energy density, short start-up time, high operational reliability and other favorable characteristics. However, major limitations include high production cost, poisoning of the catalyst and methanol crossover. This study adopts a simple technique for preparing Pt-Ru/C multilayer catalysts, including magnetron sputtering (MS) and metal-plasma ion implantation (MPII). The Pt catalysts were sputtered onto the gas diffusion layer (GDL), followed by the implantation of Ru catalysts using MPII (at an accelerating voltage of 20 kV and an implantation dose of 1 x 10(16) ions/cm2). Pt-Ru is repeatedly processed to prepare Pt-Ru/C multilayer catalysts. The catalyst film structure and microstructure were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electronic microscopy (SEM), respectively. The cell performance was tested using a potential stat/galvano-stat. The results reveal that the membrane electrode assembly (MEA) of four multilayer structures enhances the cell performance of DMFC. The measured power density is 2.2 mW/cm2 at a methanol concentration of 2 M, with an OCV of 0.493 V.

  1. Effects of Basicity and MgO in Slag on the Behaviors of Smelting Vanadium Titanomagnetite in the Direct Reduction-Electric Furnace Process

    Directory of Open Access Journals (Sweden)

    Tao Jiang

    2016-05-01

    Full Text Available The effects of basicity and MgO content on reduction behavior and separation of iron and slag during smelting vanadium titanomagnetite by electric furnace were investigated. The reduction behaviors affect the separation of iron and slag in the direct reduction-electric furnace process. The recovery rates of Fe, V, and Ti grades in iron were analyzed to determine the effects of basicity and MgO content on the reduction of iron oxides, vanadium oxides, and titanium oxides. The chemical compositions of vanadium-bearing iron and main phases of titanium slag were detected by XRF and XRD, respectively. The results show that the higher level of basicity is beneficial to the reduction ofiron oxides and vanadium oxides, and titanium content dropped in molten iron with the increasing basicity. As the content of MgO increased, the recovery rate of Fe increased slightly but the recovery rate of V increased considerably. The grades of Ti in molten iron were at a low level without significant change when MgO content was below 11%, but increased as MgO content increased to 12.75%. The optimum conditions for smelting vanadium titanomagnetite were about 11.38% content of MgO and quaternary basicity was about 1.10. The product, vanadium-bearing iron, can be applied in the converter steelmaking process, and titanium slag containing 50.34% TiO2 can be used by the acid leaching method.

  2. Deutsche Bahn. Small hydropower station Bad Abbach directly feeds electrical power into the overhead wire system; Deutsche Bahn. Kleinwasserkraftwerk Bad Abbach speist elektrische Energie unmittelbar in die Oberleitung

    Energy Technology Data Exchange (ETDEWEB)

    Hamerak, Kurt

    2009-07-01

    Even if the installed electrical power of the hydraulic power plant Bad Abbach (Federal Republic of Germany) of Deutsche Bahn AG with only 4,500 kVA is quite modest, a significant planning effort was necessary due to numerous boundary conditions. The construction of this unusual hydraulic power plant signified a very demanding and interesting technical challenge for all concerned. The already existing damming of the river Danube required very little interventions in the environment. Thus the hydraulic power plant satisfied all the requirements also in environmental regard. Due to the cooperation of a Kaplan turbine shaft with a single-phase AC generator for supplying power to the Deutsche Bahn AG and due to the direct supply of electrical energy into the overhead wire system of the railroad, the new hydropower plant Bad Abbach is unique. With Deutsche Bahn AG as a consumer of energy from hydropower plants inter alia on the river Danube a partnership between the Rhein Main Donau AG (Munich, Federal Republic of Germany) and E.ON Wasserkraft GmbH (Landshut, Federal Republic of Germany) was continued in the field of renewable energies.

  3. Model for field-induced reorientation strain in magnetic shape memory alloy with tensile and compressive loads

    International Nuclear Information System (INIS)

    Zhu Yuping; Dui Guansuo

    2008-01-01

    A model based on the micromechanical and the thermodynamic theory is presented for field-induced martensite reorientation in magnetic shape memory alloy (MSMA) single crystals. The influence of variants morphology and the material property to constitutive behavior is considered. The nonlinear and hysteretic strain and magnetization response of MSMA are investigated for two main loading cases, namely the magnetic field-induced reorientation of variants under constant compressive stress and tensile stress. The predicted results have shown that increasing tensile loading reduces the required field for actuation, while increasing compressive loads result in the required magnetic field growing considerably. It is helpful to design the intelligent composite with MSMA fibers

  4. Feasibility of a laser or charged-particle-beam fusion-reactor concept with direct electric generation by magnetic-flux compression

    International Nuclear Information System (INIS)

    Lasche, G.P.

    1983-06-01

    A new concept for an inertial-confinement fusion reactor is described which, because of its fundamentally different approach to blanket geometry and energy conversion, makes possible a unique combination of high efficiency, high power density, and low radioactivity. The conventional blanket is replaced with a liquid-density mass of lithium contiguously surrounding the fusion yield. This compact blanket configuration produces the maximum shock-induced kinetic energy in liquid metal and the maximum neutron absorption per unit mass. The shock-induced kinetic energy of the liquid lithium is converted directly to electricity with high efficiency by work done against a pulsed normal-conducting magnetic field applied to the exterior of the lithium

  5. Effect of annealing temperature on the electrical transport properties of CaRuO3-δ thin films directly deposited on the Si substrate

    International Nuclear Information System (INIS)

    Paik, Hanjong; Kim, Youngha; No, Kwangsoo; Cann, David P.; Yoon, DongJoo; Kim, ByungIl; Kim, Yangsoo

    2007-01-01

    We investigate the effect of annealing temperature on the preferentially (110)-oriented CaRuO 3-δ (CRO) thin films directly prepared on Si(100) substrate by rf magnetron sputtering. Crystalline quality and electrical transport properties of the CRO thin films were modified by post-annealing treatment. It was obvious that 700 C post-annealing brought about excellent metallic characteristics with the elevation of carrier concentration and mobility. From this result, we suggested that enhanced (110) orientation, and the ratio of chemical composition Ru 4+ /Ca 2+ ion were responsible for the transport properties of CRO thin film. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. First Limit on the Direct Detection of Lightly Ionizing Particles for Electric Charge as Low as e /1000 with the Majorana Demonstrator

    Science.gov (United States)

    Alvis, S. I.; Arnquist, I. J.; Avignone, F. T.; Barabash, A. S.; Barton, C. J.; Bertrand, F. E.; Brudanin, V.; Busch, M.; Buuck, M.; Caldwell, T. S.; Chan, Y.-D.; Christofferson, C. D.; Chu, P.-H.; Cuesta, C.; Detwiler, J. A.; Dunagan, C.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Gilliss, T.; Giovanetti, G. K.; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Haufe, C. R.; Hehn, L.; Henning, R.; Hoppe, E. W.; Howe, M. A.; Konovalov, S. I.; Kouzes, R. T.; Lopez, A. M.; Martin, R. D.; Massarczyk, R.; Meijer, S. J.; Mertens, S.; Myslik, J.; O'Shaughnessy, C.; Othman, G.; Pettus, W.; Poon, A. W. P.; Radford, D. C.; Rager, J.; Reine, A. L.; Rielage, K.; Robertson, R. G. H.; Ruof, N. W.; Shanks, B.; Shirchenko, M.; Suriano, A. M.; Tedeschi, D.; Varner, R. L.; Vasilyev, S.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C.-H.; Yumatov, V.; Zhitnikov, I.; Zhu, B. X.; Majorana Collaboration

    2018-05-01

    The Majorana Demonstrator is an ultralow-background experiment searching for neutrinoless double-beta decay in 76Ge. The heavily shielded array of germanium detectors, placed nearly a mile underground at the Sanford Underground Research Facility in Lead, South Dakota, also allows searches for new exotic physics. Free, relativistic, lightly ionizing particles with an electrical charge less than e are forbidden by the standard model but predicted by some of its extensions. If such particles exist, they might be detected in the Majorana Demonstrator by searching for multiple-detector events with individual-detector energy depositions down to 1 keV. This search is background-free, and no candidate events have been found in 285 days of data taking. New direct-detection limits are set for the flux of lightly ionizing particles for charges as low as e /1000 .

  7. How much electricity can we save by using direct current circuits in homes? Understanding the potential for electricity savings and assessing feasibility of a transition towards DC powered buildings

    International Nuclear Information System (INIS)

    Glasgo, Brock; Azevedo, Inês Lima; Hendrickson, Chris

    2016-01-01

    Highlights: • DC distribution systems are analyzed using monitored appliance and solar PV data. • DC-distributed PV energy generates savings under real-world load and solar profiles. • Savings from direct-DC are generally not cost-effective in current markets. • Non-technical hurdles remain before DC can be widely adopted in US homes. - Abstract: Advances in semiconductor-based power electronics and growing direct current loads in buildings have led researchers to reconsider whether buildings should be wired with DC circuits to reduce power conversions and facilitate a transition to efficient DC appliances. The feasibility, energy savings, and economics of such systems have been assessed and proven in data centers and commercial buildings, but the outcomes are still uncertain for the residential sector. In this work, we assess the technical and economic feasibility of DC circuits using data for 120 traditionally-wired AC homes in Austin, Texas to understand the effect of highly variable demand profiles on DC-powered residences, using appliance-level use and solar generation data, and performing a Monte Carlo simulation to quantify costs and benefits. Results show site energy savings between 9% and 20% when solar PV is distributed to all home appliances. When battery storage for excess solar energy is considered, these savings increase to 14–25%. At present DC equipment prices, converting all equipment to DC causes levelized annual costs of electricity to homeowners to roughly double. However, by converting only homes’ air conditioning condensing units to DC, the costs of direct-DC are greatly reduced and home site energy savings of 7–16% are generated. In addition to quantifying savings, we find major nontechnical barriers to implementing direct-DC in homes. These include a lack of standards for such systems, a relatively small market for DC appliances and components, utility programs designed for AC power, and a workforce unfamiliar with DC

  8. Selective observation of photo-induced electric fields inside different material components in bulk-heterojunction organic solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1, S3-33 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2014-01-06

    By using electric-field-induced optical second-harmonic generation (EFISHG) measurement at two laser wavelengths of 1000 nm and 860 nm, we investigated carrier behavior inside the pentacene and C{sub 60} component of co-deposited pentacene:C{sub 60} bulk-heterojunctions (BHJs) organic solar cells (OSCs). The EFISHG experiments verified the presence of two carrier paths for electrons and holes in BHJs OSCs. That is, two kinds of electric fields pointing in opposite directions are identified as a result of the selectively probing of SHG activation from C{sub 60} and pentacene. Also, under open-circuit conditions, the transient process of the establishment of open-circuit voltage inside the co-deposited layer has been directly probed, in terms of photovoltaic effect. The EFISHG provides an additional promising method to study carrier path of electrons and holes as well as dissociation of excitons in BHJ OSCs.

  9. External field-induced chaos in classical and quantum Hamiltonian systems

    International Nuclear Information System (INIS)

    Lin, W.C.

    1986-01-01

    Classical nonlinear nonintegrable systems exhibit dense sets of resonance zones in phase space. Global chaotic motion appears when neighboring resonance zones overlap. The chaotic motion signifies the destruction of a quasi constant of motion. The motion of a particle, trapped in one of the wells of a sinusoidal, potential driven by a monochromatic external field was studied. Global chaotic behavior sets in when the amplitude of the external field reaches a critical value. The particle then escapes the well. The critical values are found to be in good agreement with a resonance overlap criterion rather than a renormalization-group scheme. A similar system was then studied, but with the particle being confined in an infinite square well potential instead. A stochastic layer is found in the low-energy part of the phase space. The resonance zone structure is found to be in excellent agreement with predictions. The critical values for the onset of global chaotic behavior are found to be in excellent agreement with the renormalization group scheme. The quantum version of the second model above was then considered. In a similar fashion, the external field induces quantum resonance zones. The spectral statistics were computed, and a transition of statistics from Poissonian to Wigner-like was found as overlap of quantum resonances occurs. This also signifies the destruction of a quasi-constant of motion

  10. Nonlinear absorption dynamics using field-induced surface hopping: zinc porphyrin in water.

    Science.gov (United States)

    Röhr, Merle I S; Petersen, Jens; Wohlgemuth, Matthias; Bonačić-Koutecký, Vlasta; Mitrić, Roland

    2013-05-10

    We wish to present the application of our field-induced surface-hopping (FISH) method to simulate nonlinear absorption dynamics induced by strong nonresonant laser fields. We provide a systematic comparison of the FISH approach with exact quantum dynamics simulations on a multistate model system and demonstrate that FISH allows for accurate simulations of nonlinear excitation processes including multiphoton electronic transitions. In particular, two different approaches for simulating two-photon transitions are compared. The first approach is essentially exact and involves the solution of the time-dependent Schrödinger equation in an extended manifold of excited states, while in the second one only transiently populated nonessential states are replaced by an effective quadratic coupling term, and dynamics is performed in a considerably smaller manifold of states. We illustrate the applicability of our method to complex molecular systems by simulating the linear and nonlinear laser-driven dynamics in zinc (Zn) porphyrin in the gas phase and in water. For this purpose, the FISH approach is connected with the quantum mechanical-molecular mechanical approach (QM/MM) which is generally applicable to large classes of complex systems. Our findings that multiphoton absorption and dynamics increase the population of higher excited states of Zn porphyrin in the nonlinear regime, in particular in solution, provides a means for manipulating excited-state properties, such as transient absorption dynamics and electronic relaxation. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Particle roughness in magnetorheology: effect on the strength of the field-induced structures

    International Nuclear Information System (INIS)

    Vereda, F; Segovia-Gutiérrez, J P; De Vicente, J; Hidalgo-Alvarez, R

    2015-01-01

    We report a study on the effect of particle roughness on the strength of the field-induced structures of magnetorheological (MR) fluids in the quasi-static regime. We prepared one set of MR fluids with carbonyl iron particles and another set with magnetite particles, and in both sets we had particles with different degrees of surface roughness. Small amplitude oscillatory shear (SAOS) magnetosweeps and steady shear (SS) tests were carried out on the suspensions to measure their elastic modulus (G′) and static yield stress (τ static ). Results for both the iron and the magnetite sets of suspensions were consistent: for the MR fluids prepared with rougher particles, G′ increased at smaller fields and τ static was ca. 20% larger than for the suspensions prepared with relatively smooth particles. In addition to the experimental study, we carried out finite element method calculations to assess the effect of particle roughness on the magnetic interaction between particles. These calculations showed that roughness can facilitate the magnetization of the particles, thus increasing the magnetic energy of the system for a given field, but that this effect depends on the concrete morphology of the surface. For our real systems, no major differences were observed between the magnetization cycles of the MR fluids prepared with particles with different degree of roughness, which implied that the effect of roughness on the measured G′ and τ static was due mainly to friction between the solid surfaces of adjacent particles. (paper)

  12. Field induced spontaneous quasiparticle decay and renormalization of quasiparticle dispersion in a quantum antiferromagnet.

    Science.gov (United States)

    Hong, Tao; Qiu, Y; Matsumoto, M; Tennant, D A; Coester, K; Schmidt, K P; Awwadi, F F; Turnbull, M M; Agrawal, H; Chernyshev, A L

    2017-05-05

    The notion of a quasiparticle, such as a phonon, a roton or a magnon, is used in modern condensed matter physics to describe an elementary collective excitation. The intrinsic zero-temperature magnon damping in quantum spin systems can be driven by the interaction of the one-magnon states and multi-magnon continuum. However, detailed experimental studies on this quantum many-body effect induced by an applied magnetic field are rare. Here we present a high-resolution neutron scattering study in high fields on an S=1/2 antiferromagnet C 9 H 18 N 2 CuBr 4 . Compared with the non-interacting linear spin-wave theory, our results demonstrate a variety of phenomena including field-induced renormalization of one-magnon dispersion, spontaneous magnon decay observed via intrinsic linewidth broadening, unusual non-Lorentzian two-peak structure in the excitation spectra and a dramatic shift of spectral weight from one-magnon state to the two-magnon continuum.

  13. The Influence of Acoustic Field Induced by HRT on Oscillation Behavior of a Single Droplet

    Directory of Open Access Journals (Sweden)

    Can Ruan

    2017-01-01

    Full Text Available This paper presents an experimental and theoretical study on the effects of an acoustic field induced by Hartmann Resonance Tube (HRT on droplet deformation behavior. The characteristics of the acoustic field generated by HRT are investigated. Results show that the acoustic frequency decreases with the increase of the resonator length, the sound pressure level (SPL increases with the increase of nozzle pressure ratio (NPR, and it is also noted that increasing resonator length can cause SPL to decrease, which has rarely been reported in published literature. Further theoretical analysis reveals that the resonance frequency of a droplet has several modes, and when the acoustic frequency equals the droplet’s frequency, heightened droplet responses are observed with the maximum amplitude of the shape oscillation. The experimental results for different resonator cavity lengths, nozzle pressure ratios and droplet diameters confirm the non-linear nature of this problem, and this conclusion is in good agreement with theoretical analysis. Measurements by high speed camera have shown that the introduction of an acoustic field can greatly enhance droplet oscillation, which means with the use of an ultrasonic atomizer based on HRT, the quality of atomization and combustion can be highly improved.

  14. Magnetic-field induced bistability in a quasi-one-dimensional semiconductor microcavity

    International Nuclear Information System (INIS)

    Zhang, Chuanyi; Zhang, Weifeng

    2015-01-01

    We theoretically study the magnetic-field induced bistability in a quasi-one-dimensional semiconductor microcavity. A critical magnetic field is obtained, and the bistability appears if a magnetic field is greater than the critical value. For a positive energy detuning of the pump from the bare exciton polaritons, one bistability loop first emerges, then it divides into two loops, and finally one of them vanishes with the increasing magnetic field. This phenomenon originates from the magnetic-field modulated interactions for opposite spins. In the variational process, there are two important effects: one is a logic gate with a small variation of the excitation laser, and the other is a spin texture like skyrmion and this texture is periodic if the energy detuning varies periodically in real space, which is useful for designing the spin-dependent optoelectronic devices. - Highlights: • We study the bistability induced by a magnetic field in a microcavity. • One bistability loop can divide into two, and then the two loops return to one. • A spin texture like skyrmion and logic gate arise in the variation of bistability loop

  15. Excitations in the field-induced quantum spin liquid state of α-RuCl3

    Science.gov (United States)

    Banerjee, Arnab; Lampen-Kelley, Paula; Knolle, Johannes; Balz, Christian; Aczel, Adam Anthony; Winn, Barry; Liu, Yaohua; Pajerowski, Daniel; Yan, Jiaqiang; Bridges, Craig A.; Savici, Andrei T.; Chakoumakos, Bryan C.; Lumsden, Mark D.; Tennant, David Alan; Moessner, Roderich; Mandrus, David G.; Nagler, Stephen E.

    2018-03-01

    The celebrated Kitaev quantum spin liquid (QSL) is the paradigmatic example of a topological magnet with emergent excitations in the form of Majorana Fermions and gauge fluxes. Upon breaking of time-reversal symmetry, for example in an external magnetic field, these fractionalized quasiparticles acquire non-Abelian exchange statistics, an important ingredient for topologically protected quantum computing. Consequently, there has been enormous interest in exploring possible material realizations of Kitaev physics and several candidate materials have been put forward, recently including α-RuCl3. In the absence of a magnetic field this material orders at a finite temperature and exhibits low-energy spin wave excitations. However, at moderate energies, the spectrum is unconventional and the response shows evidence for fractional excitations. Here we use time-of-flight inelastic neutron scattering to show that the application of a sufficiently large magnetic field in the honeycomb plane suppresses the magnetic order and the spin waves, leaving a gapped continuum spectrum of magnetic excitations. Our comparisons of the scattering to the available calculations for a Kitaev QSL show that they are consistent with the magnetic field induced QSL phase.

  16. Magnetostrictive hypersound generation by spiral magnets in the vicinity of magnetic field induced phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Bychkov, Igor V. [Chelyabinsk State University, 129 Br. Kashirinykh Str., Chelyabinsk 454001 (Russian Federation); South Ural State University (National Research University), 76 Lenin Prospekt, Chelyabinsk 454080 (Russian Federation); Kuzmin, Dmitry A., E-mail: kuzminda@csu.ru [Chelyabinsk State University, 129 Br. Kashirinykh Str., Chelyabinsk 454001 (Russian Federation); South Ural State University (National Research University), 76 Lenin Prospekt, Chelyabinsk 454080 (Russian Federation); Kamantsev, Alexander P.; Koledov, Victor V.; Shavrov, Vladimir G. [Kotelnikov Institute of Radio-engineering and Electronics of RAS, Mokhovaya Street 11-7, Moscow 125009 (Russian Federation)

    2016-11-01

    In present work we have investigated magnetostrictive ultrasound generation by spiral magnets in the vicinity of magnetic field induced phase transition from spiral to collinear state. We found that such magnets may generate transverse sound waves with the wavelength equal to the spiral period. We have examined two types of spiral magnetic structures: with inhomogeneous exchange and Dzyaloshinskii–Moriya interactions. Frequency of the waves from exchange-caused spiral magnetic structure may reach some THz, while in case of Dzyaloshinskii–Moriya interaction-caused spiral it may reach some GHz. These waves will be emitted like a sound pulses. Amplitude of the waves is strictly depends on the phase transition speed. Some aspects of microwaves to hypersound transformation by spiral magnets in the vicinity of phase transition have been investigated as well. Results of the work may be interesting for investigation of phase transition kinetics as well, as for various hypersound applications. - Highlights: • Magnetostrictive ultrasound generation by spiral magnets at phase transition (PT) is studied. • Spiral magnets during PT may generate transverse sound with wavelength equal to spiral period. • Amplitude of the sound is strictly depends on the phase transition speed. • Microwave-to-sound transformation in the vicinity of PT is investigated as well.

  17. Tunnel Oxides Formed by Field-Induced Anodisation for Passivated Contacts of Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Jingnan Tong

    2018-02-01

    Full Text Available Tunnel silicon oxides form a critical component for passivated contacts for silicon solar cells. They need to be sufficiently thin to allow carriers to tunnel through and to be uniform both in thickness and stoichiometry across the silicon wafer surface, to ensure uniform and low recombination velocities if high conversion efficiencies are to be achieved. This paper reports on the formation of ultra-thin silicon oxide layers by field-induced anodisation (FIA, a process that ensures uniform oxide thickness by passing the anodisation current perpendicularly through the wafer to the silicon surface that is anodised. Spectroscopical analyses show that the FIA oxides contain a lower fraction of Si-rich sub-oxides compared to wet-chemical oxides, resulting in lower recombination velocities at the silicon and oxide interface. This property along with its low temperature formation highlights the potential for FIA to be used to form low-cost tunnel oxide layers for passivated contacts of silicon solar cells.

  18. Electric and magnetic fields at extremely low frequencies

    International Nuclear Information System (INIS)

    Anderson, L.E.; Kaune, W.T.

    1989-01-01

    Whole-body exposure to extremely low frequency (ELF, 30-300 Hz) electric fields may involve effects related to stimulation of the sensory apparatus at the body surface (hair vibration, possible direct neural stimulation) and effects within the body caused by the flow of current. Magnetic fields may interact predominantly by the induction of internal current flow. Biological effects observed in a living organism may depend on the electric fields induced inside the body, possibly on the magnetic fields penetrating into the body, and on the fields acting at the surface of the body. Areas in which effects have been observed often appear to be associated with the nervous system, including altered neuronal excitability and neurochemical changes, altered hormone levels, changes in behavioural responses, and changes in biological rhythms. No studies unequivocably demonstrate deleterious effects of ELF electric or magnetic field exposure on mammalian reproduction and development, but several suggest such effects. Exposure to ELF electric and magnetic fields does produce biological effects. However, except for fields strong enough to induce current densities above the threshold for the stimulation of nerve tissues, there is no consensus as to whether these effects constitute a hazard to human health. Human data from epidemiological studies, including reported effects on cancer promotion, congenital malformations, reproductive performance and general health, though somewhat suggestive of adverse health effects, are not conclusive. 274 refs, 13 figs, 6 tabs

  19. Regulation of adipose-tissue-derived stromal cell orientation and motility in 2D- and 3D-cultures by direct-current electrical field.

    Science.gov (United States)

    Yang, Gang; Long, Haiyan; Ren, Xiaomei; Ma, Kunlong; Xiao, Zhenghua; Wang, Ying; Guo, Yingqiang

    2017-02-01

    Cell alignment and motility play a critical role in a variety of cell behaviors, including cytoskeleton reorganization, membrane-protein relocation, nuclear gene expression, and extracellular matrix remodeling. Direct current electric field (EF) in vitro can direct many types of cells to align vertically to EF vector. In this work, we investigated the effects of EF stimulation on rat adipose-tissue-derived stromal cells (ADSCs) in 2D-culture on plastic culture dishes and in 3D-culture on various scaffold materials, including collagen hydrogels, chitosan hydrogels and poly(L-lactic acid)/gelatin electrospinning fibers. Rat ADSCs were exposed to various physiological-strength EFs in a homemade EF-bioreactor. Changes of morphology and movements of cells affected by applied EFs were evaluated by time-lapse microphotography, and cell survival rates and intracellular calcium oscillations were also detected. Results showed that EF facilitated ADSC morphological changes, under 6 V/cm EF strength, and that ADSCs in 2D-culture aligned vertically to EF vector and kept a good cell survival rate. In 3D-culture, cell galvanotaxis responses were subject to the synergistic effect of applied EF and scaffold materials. Fast cell movement and intracellular calcium activities were observed in the cells of 3D-culture. We believe our research will provide some experimental references for the future study in cell galvanotaxis behaviors. © 2017 Japanese Society of Developmental Biologists.

  20. Electronic structure of UN based on specific heat and field-induced transitions up to 65 T

    Czech Academy of Sciences Publication Activity Database

    Troć, R.; Samsel-Czekała, M.; Pikul, A.; Andreev, Alexander V.; Gorbunov, Denis; Skourski, Y.; Sznajd, J.

    2016-01-01

    Roč. 94, č. 22 (2016), 1-14, č. článku 224415. ISSN 2469-9950 R&D Projects: GA ČR GA16-03593S Institutional support: RVO:68378271 Keywords : uranium mononitride * antiferromagnetism * field-induced transition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.836, year: 2016

  1. Electric engineering introduction

    International Nuclear Information System (INIS)

    An, Byeong Won; Eom, Sang Ho

    1999-03-01

    It is divided into nine chapters, which includes electricity theory such as structure of material and current, nature of electricity, static, magnetic force and magnetic attraction, attraction of current and a storage battery, electric circuit on a direct current circuit, single phase circuit and 3-phase current circuit electricity machine like DC generator, DC motor, alternator, electric transformer, single-phase induction motor, 3-phase induction motor, synchronous motor, synchro electric machine, semiconductor such as diode, transistor, FET, UJT, silicon symmetrical switch, electronic circuit like smoothing circuit and Bistable MV. circuit, automatic control, measurement of electricity, electric application and safety.

  2. Characterization of Direct Current-Electrical Penetration Graph Waveforms and Correlation With the Probing Behavior of Matsumuratettix hiroglyphicus (Hemiptera: Cicadellidae), the Insect Vector of Sugarcane White Leaf Phytoplasma.

    Science.gov (United States)

    Roddee, J; Kobori, Y; Yorozuya, H; Hanboonsong, Y

    2017-06-01

    The leafhopper Matsumuratettix hiroglyphicus (Matsumura) (Hemiptera: Cicadellidae) is an important vector of phytoplasma causing white leaf disease in sugarcane. Thus, the aim of our study was to understand and describe the stylet-probing activities of this vector while feeding on sugarcane plants, by using direct current (DC) electrical penetration graph (EPG) monitoring. The EPG signals were classified into six distinct waveforms, according to amplitude, frequency, voltage level, and electrical origin of the observed traces during stylet penetration into the host plant tissues (probing). These six EPG waveforms of probing behavior comprise no stylet penetration (NP); stylet pathway through epidermis, mesophyll, and parenchymal cells (waveform A); contact at the bundle sheath layer (waveform B); salivation into phloem sieve elements (waveform C); phloem sap ingestion (waveform D); and short ingestion time of xylem sap (waveform E). The above waveform patterns were correlated with histological data of salivary sheath termini in plant tissue generated from insect stylet tips. The key findings of this study were that M. hiroglyphicus ingests the phloem sap at a relatively higher rate and for longer duration from any other cell type, suggesting that M. hiroglyphicus is mainly a phloem-feeder. Quantitative comparison of probing behavior revealed that females typically probe more frequently and longer in the phloem than males. Thus, females may acquire and inoculate greater amounts of phytoplasma than males, enhancing the efficiency of phytoplasma transmission and potentially exacerbating disease spreading. Overall, our study provides basic information on the probing behavior and transmission mechanism of M. hiroglyphicus. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Magnetic field induced augmented thermal conduction phenomenon in magneto-nanocolloids

    International Nuclear Information System (INIS)

    Katiyar, Ajay; Dhar, Purbarun; Nandi, Tandra; Das, Sarit K.

    2016-01-01

    Magnetic field induced augmented thermal conductivity of magneto-nanocolloids involving nanoparticles, viz. Fe_2O_3, Fe_3O_4, NiO and Co_3O_4 dispersed in different base fluids have been reported. Experiments reveal the augmented thermal transport under external applied magnetic field. A maximum thermal conductivity enhancement ∼114% is attained at 7.0 vol% concentration and 0.1 T magnetic flux density for Fe_3O_4/EG magneto-nanocolloid. However, a maximum ∼82% thermal conductivity enhancement is observed for Fe_3O_4/kerosene magneto-nanocolloid for the same concentration but relatively at low magnetic flux density (∼0.06 T). Thereby, a strong effect of fluid as well as particle physical properties on the chain formation propensity, leading to enhanced conduction, in such systems is observed. Co_3O_4 nanoparticles show insignificant effect on the thermal conductivity enhancement of MNCs due to their minimal magnetic moment. A semi-empirical approach has been proposed to understand the mechanism and physics behind the thermal conductivity enhancement under external applied magnetic field, in tune with near field magnetostatic interactions as well as Neel relaxivity of the magnetic nanoparticles. Furthermore, the model is able to predict the phenomenon of enhanced thermal conductivity as a function of physical parameters and shows good agreement with the experimental observations. - Highlights: • Heat conduction in magneto-nanocolloids augments tremendously under magnetic field. • Oxide nanoparticles of Fe, Ni and Co dispersed in variant base fluids are used. • Enhancement in heat conduction is due to the formation of thermally conductive chains. • Proposed semi-empirical model shows good agreement with the experimental results.

  4. Magnetic field induced augmented thermal conduction phenomenon in magneto-nanocolloids

    Energy Technology Data Exchange (ETDEWEB)

    Katiyar, Ajay, E-mail: ajay_cim@rediffmail.com [Research and Innovation Centre (DRDO), Indian Institute of Technology Madras Research Park, Chennai 600 113 (India); Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Dhar, Purbarun, E-mail: purbarun@iitrpr.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Nandi, Tandra, E-mail: tandra_n@rediffmail.com [Defence Materials and Stores Research and Development Establishment (DRDO), G.T. Road, Kanpur 208 013 (India); Das, Sarit K., E-mail: skdas@iitrpr.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India)

    2016-12-01

    Magnetic field induced augmented thermal conductivity of magneto-nanocolloids involving nanoparticles, viz. Fe{sub 2}O{sub 3}, Fe{sub 3}O{sub 4}, NiO and Co{sub 3}O{sub 4} dispersed in different base fluids have been reported. Experiments reveal the augmented thermal transport under external applied magnetic field. A maximum thermal conductivity enhancement ∼114% is attained at 7.0 vol% concentration and 0.1 T magnetic flux density for Fe{sub 3}O{sub 4}/EG magneto-nanocolloid. However, a maximum ∼82% thermal conductivity enhancement is observed for Fe{sub 3}O{sub 4}/kerosene magneto-nanocolloid for the same concentration but relatively at low magnetic flux density (∼0.06 T). Thereby, a strong effect of fluid as well as particle physical properties on the chain formation propensity, leading to enhanced conduction, in such systems is observed. Co{sub 3}O{sub 4} nanoparticles show insignificant effect on the thermal conductivity enhancement of MNCs due to their minimal magnetic moment. A semi-empirical approach has been proposed to understand the mechanism and physics behind the thermal conductivity enhancement under external applied magnetic field, in tune with near field magnetostatic interactions as well as Neel relaxivity of the magnetic nanoparticles. Furthermore, the model is able to predict the phenomenon of enhanced thermal conductivity as a function of physical parameters and shows good agreement with the experimental observations. - Highlights: • Heat conduction in magneto-nanocolloids augments tremendously under magnetic field. • Oxide nanoparticles of Fe, Ni and Co dispersed in variant base fluids are used. • Enhancement in heat conduction is due to the formation of thermally conductive chains. • Proposed semi-empirical model shows good agreement with the experimental results.

  5. Directive 96/ EC of the European Parliament and the Council of the European Union, as of 25 July 1996, announcing their common regulations for the EU internal electricity market

    International Nuclear Information System (INIS)

    1996-01-01

    The supplement to this issue of the journal, RdE 5/96, presents the German version of the full authentic text of the EU Directive 96/EC. This Directive lays down the regulations applicable within the EU, relating to electric power generation, transmission, and distribution in the EU internal electricity sector, as well as access to the internal market, criteria and procedures for bids and tenders, granting of license, and network operation. The text is also accessible under the following www address: http://www.heymanns.com. (orig./CB) [de

  6. Field-induced Gap and Quantized Charge Pumping in Nano-helix

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Xiao-Liang; /Stanford U., Phys. Dept. /Tsinghua U., Beijing; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

    2010-02-15

    We propose several novel physical phenomena based on nano-scale helical wires. Applying a static electric field transverse to the helical wire induces a metal to insulator transition, with the band gap determined by the applied voltage. Similar idea can be applied to 'geometrically' constructing one-dimensional systems with arbitrary external potential. With a quadrupolar electrode configuration, the electric field could rotate in the transverse plane, leading to a quantized dc charge current proportional to the frequency of the rotation. Such a device could be used as a new standard for the high precession measurement of the electric current. The inverse effect implies that passing an electric current through a helical wire in the presence of a transverse static electric field can lead to a mechanical rotation of the helix. This effect can be used to construct nano-scale electro-mechanical motors. Finally, our methodology also enables new ways of controlling and measuring the electronic properties of helical biological molecules such as the DNA.

  7. Enhanced Dielectronic Recombination in Crossed Electric and Magnetic Fields

    International Nuclear Information System (INIS)

    Robicheaux, F.; Pindzola, M.S.

    1997-01-01

    The dependence of the dielectronic recombination cross section on crossed electric and magnetic fields is described. The enhancement of this cross section due to a static electric field is further increased when a magnetic field is added perpendicular to the electric field. Calculation of this field induced enhancement is presented for a realistic atomic model, and the mechanism for the enhancement is discussed. copyright 1997 The American Physical Society

  8. Direct and Indirect Benefits Reported by Users of Transcutaneous Electrical Nerve Stimulation for Chronic Musculoskeletal Pain: Qualitative Exploration Using Patient Interviews.

    Science.gov (United States)

    Gladwell, Peter William; Badlan, Kathryn; Cramp, Fiona; Palmer, Shea

    2015-11-01

    There is no consensus regarding the effectiveness of transcutaneous electrical nerve stimulation (TENS) for management of chronic musculoskeletal pain or chronic low back pain. A recent review of previous trial methodology identified significant problems with low treatment fidelity. There is little information available to guide selection of patient-reported outcome measures appropriate for TENS evaluation. The purpose of this study was to explore the experiences of patients at a secondary care pain clinic who successfully used TENS to help manage chronic musculoskeletal pain. These key informants were selected because they had the potential to generate knowledge that could inform research design and clinical practice. A qualitative method using individual semistructured interviews with open questions was selected for its capacity to generate rich data. A mini focus group informed the development of a discussion guide for semistructured interviews with 9 patients (6 women, 3 men). Thematic analysis was used as the primary data analysis method, and this analysis was enhanced by a case-level analysis of the context and processes of TENS use of each individual. Data analysis indicated that distraction from pain and a reduction in the sensations associated with muscle tension or spasm should be considered as separate outcomes from pain relief. These direct benefits led to a wide range of indirect benefits dependent on patient decision making, including medication reduction, enhanced function, psychological benefits, and enhanced ability to rest. The findings indicate that evaluating TENS using a unidimensional pain scale is likely to overlook potential benefits. The complex pattern of TENS usage, as well as multiple direct and indirect outcomes, indicates that TENS could be considered as a complex intervention. © 2015 American Physical Therapy Association.

  9. Measurement and analysis of field-induced crystallographic texture using curved position-sensitive diffraction detectors

    DEFF Research Database (Denmark)

    Simons, Hugh; Daniels, John E.; Studer, Andrew J.

    2014-01-01

    This paper outlines measurement and analysis methodologies created for determining the structural responses of electroceramics to an electric field. A sample stage is developed to apply electric fields to ceramic materials at elevated temperatures during neutron diffraction experiments. The tested...... employing a curved positive sensitive detector. Methodologies are proposed to account for the geometrical effects when vector fields are applied to textured materials with angularly dispersive detector geometries. Representative results are presented for the ferroelectric (Bi1/2Na1/2)TiO3-6%BaTiO3 (BNT-6BT...

  10. Effect of the heat flux direction on electrical properties of SrBi2Nb2O9 thin films crystallized using a microwave oven

    International Nuclear Information System (INIS)

    Vasconcelos, J.S.; Vasconcelos, N.S.L.S.; Zanetti, S.M.; Leite, E.R.; Varela, J.A.; Longo, E.

    2004-01-01

    Ferroelectric SrBi 2 Nb 2 O 9 (SBN) thin films were prepared by the polymeric precursors method and deposited by spin coating onto Pt/Ti/SiO 2 /Si substrate and crystallized using a domestic microwave oven. It was studied the influence of the heat flux direction and the duration of the thermal treatment on the films crystallization. An element with high dielectric loss, a SiC susceptor, was used to absorb the microwave energy and transfers the heat to the film. Influence of the susceptor position to the sample crystallization was verified, the susceptor was placed or below the substrate or above the film. The SBN perovskite phase was observed after a thermal treatment at 700 deg. C for 10 min when the susceptor was placed below the substrate and for 30 min when the susceptor was placed above the film. Electrical measurements revealed that the film crystallized at 700 deg. C for 10 min, with the susceptor placed below the film, presented dielectric constant, dielectric loss, remanent polarization and coercive field of, 67, 0.011, 4.2 μC/cm 2 and 27.5 kV/cm, respectively. When the films were crystallized at 700 deg. C for 30 min, with the susceptor placed above the film, the dielectric constant was 115 and the dissipation factor was around of 0.033, remanent polarization and coercive field were 10.8 μC/cm 2 and 170 kV/cm, respectively

  11. Direct Yaw-Moment Control of All-Wheel-Independent-Drive Electric Vehicles with Network-Induced Delays through Parameter-Dependent Fuzzy SMC Approach

    Directory of Open Access Journals (Sweden)

    Wanke Cao

    2017-01-01

    Full Text Available This paper investigates the robust direct yaw-moment control (DYC through parameter-dependent fuzzy sliding mode control (SMC approach for all-wheel-independent-drive electric vehicles (AWID-EVs subject to network-induced delays. AWID-EVs have obvious advantages in terms of DYC over the traditional centralized-drive vehicles. However it is one of the most principal issues for AWID-EVs to ensure the robustness of DYC. Furthermore, the network-induced delays would also reduce control performance of DYC and even deteriorate the EV system. To ensure robustness of DYC and deal with network-induced delays, a parameter-dependent fuzzy sliding mode control (FSMC method based on the real-time information of vehicle states and delays is proposed in this paper. The results of cosimulations with Simulink® and CarSim® demonstrate the effectiveness of the proposed controller. Moreover, the results of comparison with a conventional FSMC controller illustrate the strength of explicitly dealing with network-induced delays.

  12. SIMULTANEOUS SPACE VECTOR MODULATION DIRECT TORQUE CONTROL OF TWO INDUCTION MOTORS USED IN ELECTRIC VEHICLES BY A NINE-SWITCH INVERTER

    Directory of Open Access Journals (Sweden)

    A. R. SHAMLOU

    2017-12-01

    Full Text Available In this paper, a novel two output nine switch-inverter is proposed in order to increase the synchronization speed of induction motors used in electric vehicles (EVs while improving the efficiency and controllability of the system. The number of switches in the proposed inverter is reduced by 25% compared to double six-switch inverters which conventionally used in EVs. The main characteristics of the considered inverter can be noted as follows: sinusoidal input and outputs, unity output power factor, and specifically, low construction cost due to active switch number reduction. The classical direct torque control method causes torque ripple and speed fluctuations. Therefore, in order to increase accuracy and dynamics of drive system, the SVM-DTC method is proposed, leading to less torque ripple and constant switching frequency. The obtained torque ripple is 2% which is less than the existing structures In order to illustrate advantages of the proposed approach, performance of the EVs in the standard cycles is evaluated.

  13. Direct label-free electrical immunodetection of transplant rejection protein biomarker in physiological buffer using floating gate AlGaN/GaN high electron mobility transistors.

    Science.gov (United States)

    Tulip, Fahmida S; Eteshola, Edward; Desai, Suchita; Mostafa, Salwa; Roopa, Subramanian; Evans, Boyd; Islam, Syed Kamrul

    2014-06-01

    Monokine induced by interferon gamma (MIG/CXCL9) is used as an immune biomarker for early monitoring of transplant or allograft rejection. This paper demonstrates a direct electrical, label-free detection method of recombinant human MIG with anti-MIG IgG molecules in physiologically relevant buffer environment. The sensor platform used is a biologically modified GaN-based high electron mobility transistor (HEMT) device. Biomolecular recognition capability was provided by using high affinity anti-MIG monoclonal antibody to form molecular affinity interface receptors on short N-hydroxysuccinimide-ester functionalized disulphide (DSP) self-assembled monolayers (SAMs) on the gold sensing gate of the HEMT device. A floating gate configuration has been adopted to eliminate the influences of external gate voltage. Preliminary test results with the proposed chemically treated GaN HEMT biosensor show that MIG can be detected for a wide range of concentration varying from 5 ng/mL to 500 ng/mL.

  14. Field-induced reentrant magnetoelectric phase in LiNiPO4

    DEFF Research Database (Denmark)

    Toft-Petersen, Rasmus; Fogh, Ellen; Kihara, Takumi

    2017-01-01

    Using pulsed magnetic fields up to 30 T we have measured the bulk magnetization and electrical polarization of LiNiPO4 and have studied its magnetic structure by time-of-flight neutron Laue diffraction. Our data establish the existence of a reentrant magnetoelectric phase between 19 T and 21 T. W...

  15. Field-Induced Deformation as a Mechanism for Scanning Tunneling Microscopy Based Nanofabrication

    DEFF Research Database (Denmark)

    Hansen, Ole; Ravnkilde, Jan Tue; Quaade, Ulrich

    1998-01-01

    The voltage between tip and sample in a scanning tunneling microscope (STM) results in a large electric field localized near the tip apex. The mechanical stress due to this field can cause appreciable deformation of both tip and sample on the scale of the tunnel gap. We derive an approximate...

  16. Design of large permanent magnetized synchronous electric machines: Low speed, high torque machines - generator for direct driven wind turbine - motor for rim driven thruster

    Energy Technology Data Exchange (ETDEWEB)

    Kroevel, Oeystein

    2011-02-15

    This work presents the design of two prototype permanent magnetized electric machines for two different applications where large permanent magnet machines might be used. Existing technology have been used as the fundament for new design and adapted to new applications, contributing, hopefully, to the development of better and more environmental friendly energy conversion. The first application presented is represented with a prototype made in cooperation with the industry in which a PM-motor is integrated into a propeller unit. Both because of the industrial connection, and the integration between the PM-motor and the propeller, the choices made for the PM-motor are conservative trying to reduce the risk. The direct rim driven thruster prototype includes a surface mounted radial flux permanent magnet machine (SM RFPM) with fractional slot winding with a q around 1. Other engineering features were introduced to make the integration of propeller and motor feasible, but without the PM-machine the thruster would not have reached the performance demand. An important part of the project was to show that the SM RFPM enables this solution, providing high performance with a large air gap. The prototype has been tested in sea, under harsh conditions, and even though the magnets have been exposed directly to sea water and been visible corroded, the electric motor still performs well within the specifications. The second application is represented with a prototype PM-generator for wind turbines. This is an example of a new, very low speed high torque machine. The generator is built to test phenomena regarding concentrated coils, and as opposed to the first application, being a pure academic university project, its success is not connected to its performance, but with the prototype's ability to expose the phenomena in question. The prototype, or laboratory model, of the generator for direct driven wind turbines features SM RFPM with concentrated coils (CC). An opportunity

  17. Field-induced magnetic instability and quantum criticality in the antiferromagnet CeCu2Ge2.

    Science.gov (United States)

    Liu, Yi; Xie, Donghua; Wang, Xiaoying; Zhu, Kangwei; Yang, Ruilong

    2016-01-13

    The magnetic quantum criticality in strongly correlated electron systems has been considered to be closely related with the occurrence of unconventional superconductivity. Control parameters such as magnetic field, pressure or chemical doping are frequently used to externally tune the quantum phase transition for a deeper understanding. Here we report the research of a field-induced quantum phase transition using conventional bulk physical property measurements in the archetypal antiferromagnet CeCu2Ge2, which becomes superconductive under a pressure of about 10 GPa with Tc ~ 0.64 K. We offer strong evidence that short-range dynamic correlations start appearing above a magnetic field of about 5 T. Our demonstrations of the magnetic instability and the field-induced quantum phase transition are crucial for the quantum criticality, which may open a new route in experimental investigations of the quantum phase transition in heavy-fermion systems.

  18. Spontaneous and field-induced phase transitions in TbFe.sub.5./sub.Al.sub.7./sub..

    Czech Academy of Sciences Publication Activity Database

    Gorbunov, Denis; Yasin, S.; Andreev, Alexander V.; Mushnikov, N. V.; Skourski, Y.; Zherlitsyn, S.; Wosnitza, J.

    2014-01-01

    Roč. 535, Sep (2014), 56-63 ISSN 0304-8853 R&D Projects: GA ČR GAP204/12/0150 Grant - others:AVČR(CZ) M100101203 Institutional support: RVO:68378271 Keywords : rare-earth intermetallics * ferrimagnetism * magnetic anisotropy * spin-reorientation transition * high magnetic fields * field-induced transition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.970, year: 2014

  19. Electricity imports from outside the Community in the EC Internal Market in electricity. Commercial policy of the EC, a subject matter of the EU internal electricity market Directive, or within national law-making competence of the EU member states?; Stromimporte aus Drittstaaten im EG-Binnenmarkt fuer Energie. Handelspolitik der EG, Gegenstand der Binnenmarkt-Richtlinien oder eigene Regelungszustaendigkeit der Mitgliedstaaten?

    Energy Technology Data Exchange (ETDEWEB)

    Gundel, J. [Freie Univ. Berlin (Germany). Inst. fuer Voelkerrecht, Euoparecht und Auslaendisches Oeffentliches Recht

    2000-07-01

    The author analyses in great depth the applicable laws and regulations as well as the Treaty of Rome in connection with the question of whether the implementation of the EU IEM Directive and the deregulation of electricity markets of EU member states really weakened the legal position of EC member states vis a vis non-member states to the extent that Community members have no means to defend themselves against dumping practices of electricity traders from outside the Community. The concluding statement of the legal analysis is that the EC member states do have the right to use the legal provisions governing competitive electricity trade inside the Community as well in dealing with traders from outside the Community. (orig./CB) [German] Der Beitrag untersucht die Frage, ob die Herstellung des Binnenmarkts fuer Elektrizitaet tatsaechlich dazu gefuehrt hat, dass Importeure aus Drittstaaten von den Mitgliedstaaten der Gemeinschaft in keiner Weise mehr beschraenkt werden koennen. Eine genauere Untersuchung der einschlaegigen Bestimmungen des EGV und des Sekundaerrechts ergibt ein differenziertes Bild; in jedem Fall sind die Mitgliedstaaten berechtigt, Beschraenkungen, die die Binnenmarkt-Richtlinien im Verhaeltnis zwischen den Mitgliedstaaten zulassen, auch im Verhaeltnis zu Drittstaaten anzuwenden. (orig./CB)

  20. 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.