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Sample records for charge conduction process

  1. Effects of electric field and charge distribution on nanoelectronic processes involving conducting polymers

    International Nuclear Information System (INIS)

    Ramos, Marta M.D.; Correia, Helena M.G.

    2006-01-01

    The injection of charge carriers in conducting polymer layers gives rise to local electric fields which should have serious implications on the charge transport through the polymer layer. The charge distribution and the related electric field inside the ensemble of polymer molecules, with different molecular arrangements at nanoscale, determine whether or not intra-molecular charge transport takes place and the preferential direction for charge hopping between neighbouring molecules. Consequently, these factors play a significant role in the competition between current flow, charge trapping and recombination in polymer-based electronic devices. By suitable Monte Carlo calculations, we simulated the continuous injection of electrons and holes into polymer layers with different microstructures and followed their transport through those polymer networks. Results of these simulations provided a detailed picture of charge and electric field distribution in the polymer layer and allowed us to assess the consequences for current transport and recombination efficiency as well as the distribution of recombination events within the polymer film. In the steady state we found an accumulation of electrons and holes near the collecting electrodes giving rise to an internal electric field which is greater than the external applied field close to the electrodes and lower than the one in the central region of the polymer layer. We also found that a strong variation of electric field inside the polymer layer leads to an increase of recombination events in regions inside the polymer layer where the values of the internal electric field are lower

  2. Charge conduction process and photovoltaic effects in thiazole yellow (TY) thin film based Schottky devices

    Energy Technology Data Exchange (ETDEWEB)

    Roy, M.S. [Defence Lab., Jodhpur (India). Camouflage Div.; Sharma, G.D.; Gupta, S.K. [Department of Physics, J.N.V. University, Jodhpur (Raj.) (India)

    1997-11-21

    The charge generation and photovoltaic effects observed with thin films of TY in the form of sandwich structures, were analysed by J-V, C-V and photoaction spectra. These measurements were explained in terms of n-type semiconductivity of TY thin film and by the formation of a Schottky barrier with ITO while Ohmic contact with an Al or In electrode. The existence of thermionic emission over the ITO-TY barrier has been observed in low voltage region, whereas at high voltages, the process is dominant by the series resistance of TY layer. Various electrical parameters were calculated from the analysis of J-V and C-V characteristics of the devices and discussed in details. The diode quality factor is higher for Al/TY/ITO than In/TY/ITO device which can be attributed to the formation of thin layer of Al{sub 2}O{sub 3} between Al and TY. The photoaction spectra of the devices reveal that the fraction of light which is absorbed near the ITO-TY interface, to the depth of 180 A, is responsible for producing the charge carriers. The photovoltaic parameters were also calculated from the J-V characteristics of the devices, under illumination and described in detail. (orig.) 21 refs.

  3. Conductivity maximum in a charged colloidal suspension

    Energy Technology Data Exchange (ETDEWEB)

    Bastea, S

    2009-01-27

    Molecular dynamics simulations of a charged colloidal suspension in the salt-free regime show that the system exhibits an electrical conductivity maximum as a function of colloid charge. We attribute this behavior to two main competing effects: colloid effective charge saturation due to counterion 'condensation' and diffusion slowdown due to the relaxation effect. In agreement with previous observations, we also find that the effective transported charge is larger than the one determined by the Stern layer and suggest that it corresponds to the boundary fluid layer at the surface of the colloidal particles.

  4. Conductivity and Space Charges in PE with Additives

    DEFF Research Database (Denmark)

    Holbøll, Joachim; Henriksen, Mogens; Hjerrild, J.

    2003-01-01

    temperatures. Space charge formation under an applied electrical field of 20 kV/mm was investigated by means of the pulse-electro-acoustic method (PEA) at room temperature. The results were compared to space charge formation and conductivity in common LDPE. The measurements showed considerable differences...... between materials and only minor influence of crosslinking process and the addition of antioxidant with respect to the electrical properties of the material. Possible correlations between conductivity and space charge formation are discussed in the paper. The relevance of the findings for application...

  5. Resonance charge exchange processes

    International Nuclear Information System (INIS)

    Duman, E.L.; Evseev, A.V.; Eletskij, A.V.; Radtsig, A.A.; Smirnov, B.M.

    1979-01-01

    The calculation results for the resonance charge exchange cross sections for positive and negative atomic and molecular ions are given. The calculations are performed on the basis of the asymptotic theory. The factors affecting the calculation accuracy are analysed. The calculation data for 28 systems are compared with the experiment

  6. Image charge forces inside conducting boundaries

    International Nuclear Information System (INIS)

    Tinkle, Mark D.; Barlow, S. E.

    2001-01-01

    The common description of the electrostatic force, F(x)=-q∇φ(x), provides an incomplete description of the force on the charge q at a point x when the charge itself induces additional fields, e.g., image charges, polarizations, etc. The equation may be corrected through the introduction of a ''pseudopotential'' formalism. Exploration of some of the elementary properties of the pseudopotential demonstrates its essential simplicity. This simplicity allows it to be incorporated directly into dynamics calculations. We explicitly evaluate the pseudopotential in a number of simple but important cases including the sphere, parallel plates, the rectangular prism, and the cylindrical box. The pseudopotential formalism may be expanded to include extended charge distributions; in this latter form we are able to directly apply the results to experimental measurements

  7. Charging and geometric effects on conduction through Anthracene molecular junctions

    Science.gov (United States)

    Kaur, Rupan Preet; Sawhney, Ravinder Singh; Engles, Derick

    We studied the geometric effects on the charge transfer through the anthracenedithiol (ADT) molecular junction using density functional theory combined with the non-equilibrium Green’s function approach. Two major geometric aspects, bond length and bond angle, were moderated to optimize the electrical conduction. From the results established in this paper, we found that the electrical conduction can be tuned from 0.2 G0 to 0.9 G0 by varying the Au-S bond length, whereas the moderation of bonding angle assayed a minor change from 0.37 G0 to 0.47 G0. We attributed this escalating zero bias conductance to the increasing charge on the terminal sulfur atom of the ADT molecule, which increased the energy of the HOMO orbital towards Fermi level and exhibited a semi-metallic behaviour. Therefore, geometry plays a critical role in deciding the charge transport through the metal/molecule interface.

  8. Space charge limited conduction in CdSe thin films

    Indian Academy of Sciences (India)

    Unknown

    of trap limited space charge limited conduction (SCLC) at higher voltage. The transition voltage (Vt ) from ohmic to SCLC is found to be quite independent of ambient temperature as well as intensity of illumination. SCLC is explained on the basis of the exponential trap distribution in CdSe films. Trap depths estimated from.

  9. Holographic conductivity for logarithmic charged dilaton-Lifshitz solutions

    Directory of Open Access Journals (Sweden)

    A. Dehyadegari

    2016-07-01

    Full Text Available We disclose the effects of the logarithmic nonlinear electrodynamics on the holographic conductivity of Lifshitz dilaton black holes/branes. We analyze thermodynamics of these solutions as a necessary requirement for applying gauge/gravity duality, by calculating conserved and thermodynamic quantities such as the temperature, entropy, electric potential and mass of the black holes/branes. We calculate the holographic conductivity for a (2+1-dimensional brane boundary and study its behavior in terms of the frequency per temperature. Interestingly enough, we find out that, in contrast to the Lifshitz–Maxwell-dilaton black branes which have conductivity for all z, here in the presence of nonlinear gauge field, the holographic conductivity does exist provided z≤3 and vanishes for z>3. It is shown that independent of the nonlinear parameter β, the real part of the conductivity is the same for a specific value of frequency per temperature in both AdS and Lifshitz cases. Besides, the behavior of real part of conductivity for large frequencies has a positive slope with respect to large frequencies for a system with Lifshitz symmetry whereas it tends to a constant for a system with AdS symmetry. This behavior may be interpreted as existence of an additional charge carrier rather than the AdS case, and is due to the presence of the scalar dilaton field in model. Similar behavior for optical conductivity of single-layer graphene induced by mild oxygen plasma exposure has been reported.

  10. ENERGETIC CHARGE OF AN INFORMATION PROCESS

    Directory of Open Access Journals (Sweden)

    Popova T.M.

    2009-12-01

    Full Text Available Main laws of technical thermodynamics are universal and could be applied to processes other than thermodynamic ones. The results of the comparison of peculiarities of irreversible informational and thermodynamic processes are presented in the article and a new term “Infopy” is used. A more precise definition of “infopy” as an energetic charge is given in the article.

  11. Charge dynamics in conducting polyaniline–metal oxalate composites

    Indian Academy of Sciences (India)

    Unknown

    Polyaniline; metal oxalate composites; charge transport; mobile and fixed spins; VRH conduc- tion mechanism ... Al, Mn and Co on doping into Pani improve the poly- merization ... dopants on charge dynamics with EPR and other tech- niques.

  12. Charge Transport Processes in Molecular Junctions

    Science.gov (United States)

    Smith, Christopher Eugene

    Molecular electronics (ME) has evolved into a rich area of exploration that combines the fields of chemistry, materials, electronic engineering and computational modeling to explore the physics behind electronic conduction at the molecular level. Through studying charge transport properties of single molecules and nanoscale molecular materials the field has gained the potential to bring about new avenues for the miniaturization of electrical components where quantum phenomena are utilized to achieve solid state molecular device functionality. Molecular junctions are platforms that enable these studies and consist of a single molecule or a small group of molecules directly connected to electrodes. The work presented in this thesis has built upon the current understanding of the mechanisms of charge transport in ordered junctions using self-assembled monolayer (SAM) molecular thin films. Donor and acceptor compounds were synthesized and incorporated into SAMs grown on metal substrates then the transport properties were measured with conducting probe atomic force microscopy (CP-AFM). In addition to experimentally measured current-voltage (I-V) curves, the transport properties were addressed computationally and modeled theoretically. The key objectives of this project were to 1) investigate the impact of molecular structure on hole and electron charge transport, 2) understand the nature of the charge carriers and their structure-transport properties through long (chemically gated to modulate the transport. These results help advance our understanding of transport behavior in semiconducting molecular thin films, and open opportunities to engineer improved electronic functionality into molecular devices.

  13. Charge state of finely divided conducting systems in dielectric matrix

    International Nuclear Information System (INIS)

    Medvedev, Yu.V.; Grishin, A.M.

    2001-01-01

    The calculation of the high statistic sum Z of the charged metal granules in the dielectric matrix is carried out with an account of the excess number of the Fermi-particles fluctuations on the granules. Application of a microscopic Hamiltonian for the energy of electrostatic interaction between the charge densities in the system makes it possible to accomplish these calculations in the average field approximation. The effect of the number of the Fermi-particles fluctuations on the charge state of the finely divided granules in the dielectric matrix is studied. It is supposed that the charge exchange between the composite metal elements occurs on the account of the electron overbarrier heat transfer. It is followed from the system high statistic sum calculation results that the i-granule medium charge is connected by the nonlinear ratio with the conductors V i potentials [ru

  14. TITANIUM DIOXIDE TRIADS FOR IMPROVED CHARGE-SEPARATION USING CONDUCTIVE POLYMERS

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, T.M.; Gaylor, T.N.; de la Garza, L.; Rajh, T.

    2009-01-01

    Dye-sensitized solar cells are potentially one of the best solutions to solar energy conversion because of the low cost of required materials and production processes. Titanium dioxide (TiO2) nanoparticulate fi lms are the basis for one of these types of cells, providing large surface area for dye-sensitizer adsorption. Because TiO2 nanoparticulate fi lms develop defects caused by oxygen defi ciency, deep reactive electron traps are formed. With the addition of an enediol ligand, these electron traps are deliberately removed, enhancing the conduction of electrons within the fi lm. In this project, TiO2 nanoparticulate fi lms made by a layer-by-layer dip coating method were modifi ed with 3,4-dihydroxyphenylacetic acid (DOPAC). DOPAC binds to the titanium atoms on the surface of the nanoparticles, restoring their octahedral geometry. This restructuring of the surface shifts the spectral properties of the TiO2 to the visible spectrum and improves the separation of charges which is observed using photoelectrochemistry. Furthermore, DOPAC enables the electronic attachment of other molecules to the surface of TiO2 fi lms, such as the conductive polymer polyaniline base. This conductive polymer provides an extended separation of charges which increases photocurrent production by forming a triad with the TiO2 semiconductor through the 3,4-dihydroxyphenylacetic acid linker. The photocurrent increases due to the donor properties of the conductive polymer thereby decreasing charge pair recombination.

  15. Charge exchange processes involving iron ions

    International Nuclear Information System (INIS)

    Phaneuf, R.A.

    1985-01-01

    A review and evaluation is given of the experimental data which are available for charge exchange processes involving iron ions and neutral H, H 2 and He. Appropriate scaling laws are presented, and their accuracy estimated for these systems. A bibliography is given of available data sources, as well as of useful data compilations and review articles. A procedure is recommended for providing single approximate formulae to the fusion community to describe total cross sections for electron capture by partially-stripped Fe/sup q+/ ions in collisions with H, H 2 and He, based on the scaling relationships suggested by Janev and Hvelplund

  16. Electrical Conductivity of Charged Particle Systems and Zubarev's Nonequilibrium Statistical Operator Method

    Science.gov (United States)

    Röpke, G.

    2018-01-01

    One of the fundamental problems in physics that are not yet rigorously solved is the statistical mechanics of nonequilibrium processes. An important contribution to describing irreversible behavior starting from reversible Hamiltonian dynamics was given by D. N. Zubarev, who invented the method of the nonequilibrium statistical operator. We discuss this approach, in particular, the extended von Neumann equation, and as an example consider the electrical conductivity of a system of charged particles. We consider the selection of the set of relevant observables. We show the relation between kinetic theory and linear response theory. Using thermodynamic Green's functions, we present a systematic treatment of correlation functions, but the convergence needs investigation. We compare different expressions for the conductivity and list open questions.

  17. Charge Carrier Conduction Mechanism in PbS Quantum Dot Solar Cells: Electrochemical Impedance Spectroscopy Study.

    Science.gov (United States)

    Wang, Haowei; Wang, Yishan; He, Bo; Li, Weile; Sulaman, Muhammad; Xu, Junfeng; Yang, Shengyi; Tang, Yi; Zou, Bingsuo

    2016-07-20

    With its properties of bandgap tunability, low cost, and substrate compatibility, colloidal quantum dots (CQDs) are becoming promising materials for optoelectronic applications. Additionally, solution-processed organic, inorganic, and hybrid ligand-exchange technologies have been widely used in PbS CQDs solar cells, and currently the maximum certified power conversion efficiency of 9.9% has been reported by passivation treatment of molecular iodine. Presently, there are still some challenges, and the basic physical mechanism of charge carriers in CQDs-based solar cells is not clear. Electrochemical impedance spectroscopy is a monitoring technology for current by changing the frequency of applied alternating current voltage, and it provides an insight into its electrical properties that cannot be measured by direct current testing facilities. In this work, we used EIS to analyze the recombination resistance, carrier lifetime, capacitance, and conductivity of two typical PbS CQD solar cells Au/PbS-TBAl/ZnO/ITO and Au/PbS-EDT/PbS-TBAl/ZnO/ITO, in this way, to better understand the charge carriers conduction mechanism behind in PbS CQD solar cells, and it provides a guide to design high-performance quantum-dots solar cells.

  18. Electrical Conductivity of Rocks and Dominant Charge Carriers. Part 1; Thermally Activated Positive Holes

    Science.gov (United States)

    Freund, Friedemann T.; Freund, Minoru M.

    2012-01-01

    The prevailing view in the geophysics community is that the electrical conductivity structure of the Earth's continental crust over the 5-35 km depth range can best be understood by assuming the presence of intergranular fluids and/or of intragranular carbon films. Based on single crystal studies of melt-grown MgO, magma-derived sanidine and anorthosite feldspars and upper mantle olivine, we present evidence for the presence of electronic charge carriers, which derive from peroxy defects that are introduced during cooling, under non-equilibrium conditions, through a redox conversion of pairs of solute hydroxyl arising from dissolution of H2O.The peroxy defects become thermally activated in a 2-step process, leading to the release of defect electrons in the oxygen anion sublattice. Known as positive holes and symbolized by h(dot), these electronic charge carriers are highly mobile. Chemically equivalent to O(-) in a matrix of O(2-) they are highly oxidizing. Being metastable they can exist in the matrix of minerals, which crystallized in highly reduced environments. The h(dot) are highly mobile. They appear to control the electrical conductivity of crustal rocks in much of the 5-35 km depth range.

  19. Electric Double-Layer Interaction between Dissimilar Charge-Conserved Conducting Plates.

    Science.gov (United States)

    Chan, Derek Y C

    2015-09-15

    Small metallic particles used in forming nanostructured to impart novel optical, catalytic, or tribo-rheological can be modeled as conducting particles with equipotential surfaces that carry a net surface charge. The value of the surface potential will vary with the separation between interacting particles, and in the absence of charge-transfer or electrochemical reactions across the particle surface, the total charge of each particle must also remain constant. These two physical conditions require the electrostatic boundary condition for metallic nanoparticles to satisfy an equipotential whole-of-particle charge conservation constraint that has not been studied previously. This constraint gives rise to a global charge conserved constant potential boundary condition that results in multibody effects in the electric double-layer interaction that are either absent or are very small in the familiar constant potential or constant charge or surface electrochemical equilibrium condition.

  20. Space charge limited current conduction in Bi2Te3 thin films

    International Nuclear Information System (INIS)

    Sathyamoorthy, R.; Dheepa, J.; Velumani, S.

    2007-01-01

    Bi 2 Te 3 is known for its large thermoelectric coefficients and is widely used as a material for Peltier devices. Bi 2 Te 3 thin films with thicknesses in the range 125-300 A have been prepared by Flash Evaporation at a pressure of 10 -5 m bar on clean glass substrates at room temperature. An Al-Bi 2 Te 3 -Al sandwich structure has been used for electrical conduction properties in the temperature range 303 to 483 K. I-V characteristics showed Ohmic conduction in the low voltage region. In the higher voltage region, a Space Charge Limited Conduction (SCLC) takes place due to the presence of the trapping level. The transition voltage (V t ), between the Ohmic and the SCLC condition was proportional to the square of thickness. Further evidence for this conduction process was provided by the linear dependence of V t on t 2 and log J on log t. The hole concentration in the films were found to be n 0 = 1.65 * 10 10 m -3 . The carrier mobility increases with increasing temperature whereas the density of trapped charges decreases with increasing temperature. The barrier height decreases with an increase in temperature. The increase in the trapping concentration V t is correlated with ascending the degree of preferred orientation of the highest atomic density plane. The activation energy was estimated and the values found to decrease with increasing applied voltage. The zero field value of the activation energy is found to be 0.4 eV

  1. Charge equilibrium processes of energetic incident ions and their range

    International Nuclear Information System (INIS)

    Kawagoshi, Hiroshi; Karashima, Shosuke; Watanabe, Tsutomu.

    1984-01-01

    The charge state of energetic ions passing through a certain matter is varied by charge-exchange processes. A rate equation for charge fraction is given by using electron loss and capture cross sections in collision with a target atom under idealized condition. We solved the rate equation of the charge-exchange process of a single electron in a form of linear coupled differential equation. Our calcuiation for the range of ion were carried out for He, Ne and Ar ions passing through an atomic hydrogen gas target. We discuss the charge states of the projectile in relation to a local charge balance consituting a state of charge equilibrium in the target. (author)

  2. Analysis of Conduction and Charging Mechanisms in Atomic Layer Deposited Multilayered HfO2/Al2O3 Stacks for Use in Charge Trapping Flash Memories

    Directory of Open Access Journals (Sweden)

    Nenad Novkovski

    2018-01-01

    Full Text Available Method for characterization of electrical and trapping properties of multilayered high permittivity stacks for use in charge trapping flash memories is proposed. Application of the method to the case of multilayered HfO2/Al2O3 stacks is presented. By applying our previously developed comprehensive model for MOS structures containing high-κ dielectrics on the J-V characteristics measured in the voltage range without marked degradation and charge trapping (from −3 V to +3 V, several parameters of the structure connected to the interfacial layer and the conduction mechanisms have been extracted. We found that the above analysis gives precise information on the main characteristics and the quality of the injection layer. C-V characteristics of stressed (with write and erase pulses structures recorded in a limited range of voltages between −1 V and +1 V (where neither significant charge trapping nor visible degradation of the structures is expected to occur were used in order to provide measures of the effect of stresses with no influence of the measurement process. Both trapped charge and the distribution of interface states have been determined using modified Terman method for fresh structures and for structures stressed with write and erase cycles. The proposed method allows determination of charge trapping and interface state with high resolution, promising a precise characterization of multilayered high permittivity stacks for use in charge trapping flash memories.

  3. A study of charge transfer kinetics in dye-sensitized surface conductivity solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Dennis

    2011-05-15

    The efficiency of the quasi-solid-state dye-sensitized solar cell developed by Junghaenel and Tributsch, the so-called Nano Surface Conductivity Solar Cell (NSCSC), was improved from 2% to 3.5% introducing a compact TiO{sub 2} underlayer, modifying the surface of the mesoporous TiO{sub 2} electrode, optimizing the deposition process of the electrolyte film, and replacing the platinum counter electrode by a carbon layer. Space-resolved photocurrent images revealed the importance of a homogeneous distribution of the electrolyte film. An uneven dispersion led to localized areas of high and low photocurrents, whereas the latter were attributed to an insufficient concentration of the redox couple. Impedance spectroscopy was performed on cells containing different concentrations of the redox couple. By modeling the spectra using an equivalent circuit with a transmission line of resistive and capacitive elements, the characteristic parameters of electron transport in the TiO{sub 2}, such as diffusion length and electron lifetime were obtained. The measurements indicated that the transport of the positive charge to the counter electrode is the main process limiting the efficiency of the cells. Excess charge carrier decay in functioning devices was analyzed by contactless transient photoconductance measurements in the microwave frequency range (TRMC). The lifetime of the photogenerated charge carriers was observed to decrease with increasing applied potential, reaching its maximum close to the opencircuit potential of the cell, where the photocurrent density was minimal, i.e. the potential dependent decay observed was limited by the injection of electrons into the front contact. The functioning of this NSCSC indicated that the transport of the positive charge occurs by solid-state diffusion at the surface of the TiO{sub 2} particles. TRMC measurements on subset devices in the form of sensitized TiO{sub 2} layers revealed charge carrier kinetics strongly dependent on the

  4. Transition density of charge-exchange processes

    International Nuclear Information System (INIS)

    Lovas, R.G.

    1983-01-01

    The transition density between parent and analogue states is studied with special reference to its role in charge-exchange nuclear reactions. The structure of the target nucleus is described in a perturbative approach, in which the Coulomb and asymmetry potentials mix the eigenstates of a charge-independent single-particle Hamiltonian. In this model formulae are derived for the transition density, the Coulomb displacement energy and the neutron-proton density difference, and their relationship is used to estimate the transition density. This estimate shows that: the largest contribution comes from the density of the excess neutrons; the weight of the Coulomb-mixing effect is small up to excess neutron number 10, and grows rapidly beyond; the weight of the core polarization term induced by the excess neutrons is modest and is the same for all nuclei. It is indicated that the Coulomb effect may explain the departure from the Lane model of nucleon charge-exchange scattering found for heavy nuclei, whereas the core polarization may account for the observed anomalous dependence of the deg 0 pion charge-exchange cross section on the number of excess neutrons. (author)

  5. Enhanced charging kinetics of porous electrodes: surface conduction as a short-circuit mechanism.

    Science.gov (United States)

    Mirzadeh, Mohammad; Gibou, Frederic; Squires, Todd M

    2014-08-29

    We use direct numerical simulations of the Poisson-Nernst-Planck equations to study the charging kinetics of porous electrodes and to evaluate the predictive capabilities of effective circuit models, both linear and nonlinear. The classic transmission line theory of de Levie holds for general electrode morphologies, but only at low applied potentials. Charging dynamics are slowed appreciably at high potentials, yet not as significantly as predicted by the nonlinear transmission line model of Biesheuvel and Bazant. We identify surface conduction as a mechanism which can effectively "short circuit" the high-resistance electrolyte in the bulk of the pores, thus accelerating the charging dynamics and boosting power densities. Notably, the boost in power density holds only for electrode morphologies with continuous conducting surfaces in the charging direction.

  6. Enhanced ionic conductivity in composite materials due to interfacial space charge layers

    International Nuclear Information System (INIS)

    Dudney, N.J.

    1985-01-01

    The ionic conductivity of a number of salts (e.g., β-AgI, LiI, CuCl, HgI 2 , etc.) can be enhanced by one to three orders of magnitude with the addition of fine particles of an insoluble and nonconducting material such as Al 2 O 3 or SiO 2 . Typically the conductivity increases with addition of the inert particles and reaches a peak at 10-40 vol % of the particles. The mechanism responsible for the enhanced conductivity of the composite is not understood at this time. Some claim that this effect is due to an increased concentration of charge carriers in a diffuse space charge layer near the charged surface of the particle. The goal of the present study is to test this proposed mechanism by calculating the maximum space charge layer effect and then using this result to estimate the conductivity of a composite with a random distribution of Al 2 O 3 particles. Also, the conductivity of composite systems has been investigated assuming an ordered distribution of particles which are surrounded by a high conductivity layer

  7. Interpreting equilibrium-conductivity and conductivity-relaxation measurements to establish thermodynamic and transport properties for multiple charged defect conducting ceramics.

    Science.gov (United States)

    Zhu, Huayang; Ricote, Sandrine; Coors, W Grover; Kee, Robert J

    2015-01-01

    A model-based interpretation of measured equilibrium conductivity and conductivity relaxation is developed to establish thermodynamic, transport, and kinetics parameters for multiple charged defect conducting (MCDC) ceramic materials. The present study focuses on 10% yttrium-doped barium zirconate (BZY10). In principle, using the Nernst-Einstein relationship, equilibrium conductivity measurements are sufficient to establish thermodynamic and transport properties. However, in practice it is difficult to establish unique sets of properties using equilibrium conductivity alone. Combining equilibrium and conductivity-relaxation measurements serves to significantly improve the quantitative fidelity of the derived material properties. The models are developed using a Nernst-Planck-Poisson (NPP) formulation, which enables the quantitative representation of conductivity relaxations caused by very large changes in oxygen partial pressure.

  8. Integer Charge Transfer and Hybridization at an Organic Semiconductor/Conductive Oxide Interface

    KAUST Repository

    Gruenewald, Marco

    2015-02-11

    We investigate the prototypical hybrid interface formed between PTCDA and conductive n-doped ZnO films by means of complementary optical and electronic spectroscopic techniques. We demonstrate that shallow donors in the vicinity of the ZnO surface cause an integer charge transfer to PTCDA, which is clearly restricted to the first monolayer. By means of DFT calculations, we show that the experimental signatures of the anionic PTCDA species can be understood in terms of strong hybridization with localized states (the shallow donors) in the substrate and charge back-donation, resulting in an effectively integer charge transfer across the interface. Charge transfer is thus not merely a question of locating the Fermi level above the PTCDA electron-transport level but requires rather an atomistic understanding of the interfacial interactions. The study reveals that defect sites and dopants can have a significant influence on the specifics of interfacial coupling and thus on carrier injection or extraction.

  9. BSW process of the slowly evaporating charged black hole

    OpenAIRE

    Wang, Liancheng; He, Feng; Fu, Xiangyun

    2015-01-01

    In this paper, we study the BSW process of the slowly evaporating charged black hole. It can be found that the BSW process will also arise near black hole horizon when the evaporation of charged black hole is very slow. But now the background black hole does not have to be an extremal black hole, and it will be approximately an extremal black hole unless it is nearly a huge stationary black hole.

  10. Production processes of multiply charged ions by electron impact

    International Nuclear Information System (INIS)

    Oda, Nobuo

    1980-02-01

    First, are compared the foil or gas stripper and the ion sources utilizing electron-atom ionizing collisions, which are practically used or are under development to produce multiply charged ions. A review is made of the fundamental physical parameters such as successive ionization potentials and various ionization cross sections by electron impact, as well as the primary processes in multiply charged ion production. Multiply charged ion production processes are described for the different existing ion sources such as high temperature plasma type, ion-trapping type and discharge type. (author)

  11. Comparison of the Volume Charge Density of Nanofiltration Membranes Obtained from Retention and Conductivity Experiments

    DEFF Research Database (Denmark)

    Benavente, J.; Silva, V.; Pradanos, P.

    2010-01-01

    A version of the Donnan steric-partitioning pore model with dielectrical exclusion (DSPM-DE) has been used to get information on the pore size and charge density of a commercial membrane, NF45 from FilmTec, from its retention of KCl solutions. The conductivity inside the pores has been measured b...

  12. Combined centroid-envelope dynamics of intense, magnetically focused charged beams surrounded by conducting walls

    International Nuclear Information System (INIS)

    Fiuza, K.; Rizzato, F.B.; Pakter, R.

    2006-01-01

    In this paper we analyze the combined envelope-centroid dynamics of magnetically focused high-intensity charged beams surrounded by conducting walls. Similar to the case where conducting walls are absent, it is shown that the envelope and centroid dynamics decouple from each other. Mismatched envelopes still decay into equilibrium with simultaneous emittance growth, but the centroid keeps oscillating with no appreciable energy loss. Some estimates are performed to analytically obtain characteristics of halo formation seen in the full simulations

  13. Electrical conductivity and charge diffusion in thermal QCD from the lattice

    Energy Technology Data Exchange (ETDEWEB)

    Aarts, Gert; Allton, Chris [Department of Physics, College of Science, Swansea University Swansea SA2 8PP (United Kingdom); Amato, Alessandro [Department of Physics, College of Science, Swansea University Swansea SA2 8PP (United Kingdom); Department of Physics and Helsinki Institute of Physics P.O. Box 64, FI-00014 University of Helsinki (Finland); Giudice, Pietro [Universität Münster, Institut für Theoretische Physik Wilhelm-Klemm-Str. 9, D-48149 Münster (Germany); Hands, Simon [Department of Physics, College of Science, Swansea University Swansea SA2 8PP (United Kingdom); Skullerud, Jon-Ivar [Department of Mathematical Physics, National University of Ireland Maynooth Maynooth, Co Kildare (Ireland)

    2015-02-27

    We present a lattice QCD calculation of the charge diffusion coefficient, the electrical conductivity and various susceptibilities of conserved charges, for a range of temperatures below and above the deconfinement crossover. The calculations include the contributions from up, down and strange quarks. We find that the diffusion coefficient is of the order of 1/(2πT) and has a dip around the crossover temperature. Our results are obtained with lattice simulations containing 2+1 dynamical flavours on anisotropic lattices. The Maximum Entropy Method is used to construct spectral functions from correlators of the conserved vector current.

  14. Space charge and steady state current in LDPE samples containing a permittivity/conductivity gradient

    DEFF Research Database (Denmark)

    Holbøll, Joachim; Bambery, K. R.; Fleming, R. J.

    2000-01-01

    Electromagnetic theory predicts that a dielectric sample in which a steady DC current of density ε is flowing, and in which the ratio of permittivity ε to conductivity σ varies with position, will acquire a space charge density j·grad(ε/σ). A simple and convenient way to generate an ε/σ gradient...... in a homogeneous sample is to establish a temperature gradient across it. The resulting spatial variation in ε is usually small in polymeric insulators, but the variation in σ can be appreciable. Laser induced pressure pulse (LIPP) measurements were made on 1.5 mm thick plaques of ultra pure LDPE equipped...... with vacuum-evaporated aluminium electrodes. Temperature differences up to 27°C were maintained across the samples, which were subjected to DC fields up to 20 kV/mm. Current density was measured as a function of temperature and field. Negligible thermally generated space charge was observed. The charge...

  15. Theoretical treatment of charge transfer processes of relevance to astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Krstic, P.S.; Stancil, P.C.; Schultz, D.R.

    1997-12-01

    Charge transfer is an important process in many astrophysical and atmospheric environments. While numerous experimental and theoretical studies exist for H and He targets, data on other targets, particularly metals and molecules, are sparse. Using a variety of theoretical methods and computational techniques the authors are developing methods to estimate the cross sections for electron capture (charge transfer) in slow collisions of low charge state ions with heavy (Mg, Ca, Fe, Co, Ni and Zn) neutrals. In this ongoing work particular attention is paid to ascertaining the importance of double electron capture.

  16. Theoretical treatment of charge transfer processes of relevance to astrophysics

    International Nuclear Information System (INIS)

    Krstic, P.S.; Stancil, P.C.; Schultz, D.R.

    1997-12-01

    Charge transfer is an important process in many astrophysical and atmospheric environments. While numerous experimental and theoretical studies exist for H and He targets, data on other targets, particularly metals and molecules, are sparse. Using a variety of theoretical methods and computational techniques the authors are developing methods to estimate the cross sections for electron capture (charge transfer) in slow collisions of low charge state ions with heavy (Mg, Ca, Fe, Co, Ni and Zn) neutrals. In this ongoing work particular attention is paid to ascertaining the importance of double electron capture

  17. Carbon Nanotube/Conductive Additive/Space Durable Polymer Nanocomposite Films for Electrostatic Charge Dissipation

    Science.gov (United States)

    Smith, Joseph G., Jr.; Watson, Kent A.; Delozier, Donavon M.; Connell, John W.

    2003-01-01

    Thin film membranes of space environmentally stable polymeric materials possessing low color/solar absorptivity (alpha) are of interest for potential applications on Gossamer spacecraft. In addition to these properties, sufficient electrical conductivity is required in order to dissipate electrostatic charge (ESC) build-up brought about by the charged orbital environment. One approach to achieve sufficient electrical conductivity for ESC mitigation is the incorporation of single wall carbon nanotubes (SWNTs). However, when the SWNTs are dispersed throughout the polymer matrix, the nanocomposite films tend to be significantly darker than the pristine material resulting in a higher alpha. The incorporation of conductive additives in combination with a decreased loading level of SWNTs is one approach for improving alpha while retaining conductivity. Taken individually, the low loading level of conductive additives and SWNTs is insufficient in achieving the percolation level necessary for electrical conductivity. When added simultaneously to the film, conductivity is achieved through a synergistic effect. The chemistry, physical, and mechanical properties of the nanocomposite films will be presented.

  18. Study of temperature-dependent charge conduction in silicon-nanocrystal/SiO_2 multilayers

    International Nuclear Information System (INIS)

    Mavilla, Narasimha Rao; Chavan, Vinayak; Solanki, Chetan Singh; Vasi, Juzer

    2016-01-01

    Silicon-nanocrystals (Si-NCs) realized by SiO_x _ 8 MV/cm; independent of temperature), while for lower electric fields (5–8 MV/cm) at higher temperatures, the trap-related Generalized Poole–Frenkel (GPF) is dominant. This signified the role of traps in modifying the conduction in bulk ICPCVD SiO_2 films. We then present the conduction in ML samples. For multilayer samples with SiO_2 sublayer thickness of 1.5 nm and 2.5 nm, Direct Tunneling (DT) is observed to be dominant, while for SiO_2 sublayer thickness of 3.5 nm, Space Charge Limited Conduction (SCLC) with exponential trap distribution is found to be the dominant conduction mechanism. This signifies the role of traps in modifying the conduction in Si-NC multilayer samples and SiO_2 sublayer thickness dependence. - Highlights: • Electrical conduction in SiO_2 film & Si-nanocrystal layers (Si-NCs) is reported. • SiO_2/SiO_x multilayer based Si-NCs were realized by Inductively Coupled plasma CVD. • For SiO_2 film, Fowler–Nordheim tunneling & Generalized Poole–Frenkel are observed. • For Si-NCs with thin SiO_2 sublayers (< 2.5 nm) Direct Tunneling is dominant. • For Si-NCs with 3.5 nm SiO_2 sublayers Space Charge Limited Conduction is dominant.

  19. Nonmonotonic anisotropy in charge conduction induced by antiferrodistortive transition in metallic SrTiO3

    Science.gov (United States)

    Tao, Qian; Loret, Bastien; Xu, Bin; Yang, Xiaojun; Rischau, Carl Willem; Lin, Xiao; Fauqué, Benoît; Verstraete, Matthieu J.; Behnia, Kamran

    2016-07-01

    Cubic SrTiO3 becomes tetragonal below 105 K. The antiferrodistortive (AFD) distortion leads to clockwise and counterclockwise rotation of adjacent TiO6 octahedra. This insulator becomes a metal upon the introduction of extremely low concentration of n -type dopants. However, signatures of the structural phase transition in charge conduction have remained elusive. Employing the Montgomery technique, we succeed in resolving the anisotropy of charge conductivity induced by the AFD transition, in the presence of different types of dopants. We find that the slight lattice distortion (liquids, the anisotropy has opposite signs for elastic and inelastic scattering. Increasing the concentration of dopants leads to a drastic shift in the temperature of the AFD transition either upward or downward. The latter result puts strong constraints on any hypothetical role played by the AFD soft mode in the formation of Cooper pairs and the emergence of superconductivity in SrTiO3.

  20. Description of charging/discharging processes of the LISA sensors

    International Nuclear Information System (INIS)

    Sumner, Tim; Araujo, Henrique; Davidge, David; Howard, Alex; Lee, Chris; Rochester, Geoff; Shaul, Diana; Wass, Peter

    2004-01-01

    The next generation of gravitational experiments in space is likely to use completely isolated proof-masses. For example, LISA uses proof-masses as mirrors in interferometers for gravitational wave astronomy (Bender et al 1998 Pre-phase A report MPG-233 pp 1-191) and STEP uses proof-masses in Earth orbit for an equivalence principle test (Sumner et al 2003 at press). Nongravitational forces will act on these proof-masses if they become charged, through the action of cosmic rays and solar flare particles for example. This paper examines the consequences of proof-mass charging for LISA, and presents results from using GEANT4 to assess the charging processes. Finally, there is a brief discussion of a means of controlling the charge down to an acceptable level

  1. Induced-charge electroosmosis around conducting and Janus cylinder in microchip

    Directory of Open Access Journals (Sweden)

    Zhang Kai

    2012-01-01

    Full Text Available The induced-charge elecetroosmosis around conducting/Janus cylinder with arbitrary Debye thickness is studied numerically, when an direct current weak electric filed is suddenly applied in a confined microchannel. It’s found that there are four large circulations around the conducting cylinder, and the total flux in the microchannel is zero; there are two smaller circulations around the Janus cylinder, and they are compressed to wall. A bulk flux, which has a parabolic relation with the applied electric field, is also predicted.

  2. Study of temperature-dependent charge conduction in silicon-nanocrystal/SiO{sub 2} multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Mavilla, Narasimha Rao; Chavan, Vinayak [National Centre for Photovoltaic Research and Education (NCPRE), Powai, Mumbai 400 076 (India); Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076 (India); Solanki, Chetan Singh [National Centre for Photovoltaic Research and Education (NCPRE), Powai, Mumbai 400 076 (India); Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076 (India); Vasi, Juzer [National Centre for Photovoltaic Research and Education (NCPRE), Powai, Mumbai 400 076 (India); Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076 (India)

    2016-08-01

    Silicon-nanocrystals (Si-NCs) realized by SiO{sub x} {sub <} {sub 2}/SiO{sub 2} multilayer (ML) approach have shown promise for realizing tightly-controlled dimensions, thus efficiently exploiting the size-dependent quantum effects for device applications. Unfortunately, the confining insulating barriers (SiO{sub 2} sublayers), instrumental for realizing quantum size effects in Si-NC MLs, can also hinder the charge conduction which is crucial for device applications including Si-NC based tandem solar cells and multi-exciton solar cells. Owing to this, a comprehensive study of conduction mechanisms has been carried out using a thorough analysis of temperature-dependent dark I-V measurements of SiO{sub 2} thin film and Si-NC multilayer samples fabricated by Inductively Coupled Plasma CVD (ICPCVD). As the ML samples consisted of interleaved SiO{sub 2} sublayers, current in SiO{sub 2} thin film has initially been studied to understand the conduction properties of bulk ICPCVD SiO{sub 2}. For 21 nm thick SiO{sub 2} film, conduction is observed to be dominated by Fowler–Nordheim (FN) tunneling for higher electric fields (> 8 MV/cm; independent of temperature), while for lower electric fields (5–8 MV/cm) at higher temperatures, the trap-related Generalized Poole–Frenkel (GPF) is dominant. This signified the role of traps in modifying the conduction in bulk ICPCVD SiO{sub 2} films. We then present the conduction in ML samples. For multilayer samples with SiO{sub 2} sublayer thickness of 1.5 nm and 2.5 nm, Direct Tunneling (DT) is observed to be dominant, while for SiO{sub 2} sublayer thickness of 3.5 nm, Space Charge Limited Conduction (SCLC) with exponential trap distribution is found to be the dominant conduction mechanism. This signifies the role of traps in modifying the conduction in Si-NC multilayer samples and SiO{sub 2} sublayer thickness dependence. - Highlights: • Electrical conduction in SiO{sub 2} film & Si-nanocrystal layers (Si-NCs) is reported. • Si

  3. Stochastic Lorentz forces on a point charge moving near the conducting plate

    International Nuclear Information System (INIS)

    Hsiang, J.-T.; Wu, T.-H.; Lee, D.-S.

    2008-01-01

    The influence of quantized electromagnetic fields on a nonrelativistic charged particle moving near a conducting plate is studied. We give a field-theoretic derivation of the nonlinear, non-Markovian Langevin equation of the particle by the method of Feynman-Vernon influence functional. This stochastic approach incorporates not only the stochastic noise manifested from electromagnetic vacuum fluctuations, but also dissipation backreaction on a charge in the form of the retarded Lorentz forces. Since the imposition of the boundary is expected to anisotropically modify the effects of the fields on the evolution of the particle, we consider the motion of a charge undergoing small-amplitude oscillations in the direction either parallel or normal to the plane boundary. Under the dipole approximation for nonrelativistic motion, velocity fluctuations of the charge are found to grow linearly with time in the early stage of the evolution at the rather different rate, revealing strong anisotropic behavior. They are then asymptotically saturated as a result of the fluctuation-dissipation relation, and the same saturated value is found for the motion in both directions. The observational consequences are discussed

  4. Management of article processing charges – challenges for libraries

    Directory of Open Access Journals (Sweden)

    Adriana Sikora

    2015-07-01

    Full Text Available Dedicated funds for Open Access publishing have been a strategic instrument at German university libraries for many years. As the number of Open Access publications grows dynamically, the question arises as to whether the processes of handling article processing charges (APC are being sustainably organised among libraries and publishers so as to enable a full transition to Open Access. Max Planck Digital Library processes about 600 invoices for Open Access articles per year centrally on behalf of Max Planck researchers. This paper contains a description of the individual steps required in order to assume charges centrally as well as the barriers emerging during this process. It is shown that the main desiderata for the establishment of smooth and scalable processes are the optimisation of article submission systems, better author identification and assignment, and improved reporting.

  5. Analysis of two dimensional charged particle scintillation using video image processing techniques

    International Nuclear Information System (INIS)

    Sinha, A.; Bhave, B.D.; Singh, B.; Panchal, C.G.; Joshi, V.M.; Shyam, A.; Srinivasan, M.

    1993-01-01

    A novel method for video recording of individual charged particle scintillation images and their offline analysis using digital image processing techniques for obtaining position, time and energy information is presented . Results of an exploratory experiment conducted using 241 Am and 239 Pu alpha sources are presented. (author). 3 figs., 4 tabs

  6. Surface charge conductivity of a topological insulator in a magnetic field: The effect of hexagonal warping

    Science.gov (United States)

    Akzyanov, R. S.; Rakhmanov, A. L.

    2018-02-01

    We investigate the influence of hexagonal warping on the transport properties of topological insulators. We study the charge conductivity within Kubo formalism in the first Born approximation using low-energy expansion of the Hamiltonian near the Dirac point. The effects of disorder, magnetic field, and chemical-potential value are analyzed in detail. We find that the presence of hexagonal warping significantly affects the conductivity of the topological insulator. In particular, it gives rise to the growth of the longitudinal conductivity with the increase of the disorder and anisotropic anomalous in-plane magnetoresistance. Hexagonal warping also affects the quantum anomalous Hall effect and anomalous out-of-plane magnetoresistance. The obtained results are consistent with the experimental data.

  7. Introduction of article-processing charges for Population Health Metrics

    Directory of Open Access Journals (Sweden)

    Murray Christopher JL

    2003-11-01

    Full Text Available Abstract Population Health Metrics is an open-access online electronic journal published by BioMed Central – it is universally and freely available online to everyone, its authors retain copyright, and it is archived in at least one internationally recognised free repository. To fund this, from November 1 2003, authors of articles accepted for publication will be asked to pay an article-processing charge of US$500. This editorial outlines the reasons for the introduction of article-processing charges and the way in which this policy will work. Waiver requests will be considered on a case-by-case basis, by the Editor-in-Chief. Article-processing charges will not apply to authors whose institutions are 'members' of BioMed Central. Current members include NHS England, the World Health Organization, the US National Institutes of Health, Harvard, Princeton and Yale universities, and all UK universities. No charge is made for articles that are rejected after peer review. Many funding agencies have also realized the importance of open access publishing and have specified that their grants may be used directly to pay APCs.

  8. Study on Charged Top-Pion Decay Processes

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-Lei; XU Wen-Na; DU Lin-Lin

    2004-01-01

    In the framework of top-color assisted technicolor (TC2) theory, we study the four decay processes of charged top-pion, i.e., П+t → t-b, П+t → c-b, П+t → W+γ П+t → W+ Z0. The decay branching ratio of these modes are calculated. The results show that the main decay channels of charged top-pion are the tree level modes: П+t → t-b and П+t → c-b. Light П+t is easier to be detected than heavy one at future coliders. So, the study provides us with some useful informations to search for charged top-pion.

  9. Engineering charge transport by heterostructuring solution-processed semiconductors

    Science.gov (United States)

    Voznyy, Oleksandr; Sutherland, Brandon R.; Ip, Alexander H.; Zhitomirsky, David; Sargent, Edward H.

    2017-06-01

    Solution-processed semiconductor devices are increasingly exploiting heterostructuring — an approach in which two or more materials with different energy landscapes are integrated into a composite system. Heterostructured materials offer an additional degree of freedom to control charge transport and recombination for more efficient optoelectronic devices. By exploiting energetic asymmetry, rationally engineered heterostructured materials can overcome weaknesses, augment strengths and introduce emergent physical phenomena that are otherwise inaccessible to single-material systems. These systems see benefit and application in two distinct branches of charge-carrier manipulation. First, they influence the balance between excitons and free charges to enhance electron extraction in solar cells and photodetectors. Second, they promote radiative recombination by spatially confining electrons and holes, which increases the quantum efficiency of light-emitting diodes. In this Review, we discuss advances in the design and composition of heterostructured materials, consider their implementation in semiconductor devices and examine unexplored paths for future advancement in the field.

  10. Effect of charged line defects on conductivity in graphene: Numerical Kubo and analytical Boltzmann approaches

    DEFF Research Database (Denmark)

    Radchenko, T. M.; Shylau, A. A.; Zozoulenko, I. V.

    2013-01-01

    . A numerical study of electronic transport is performed by means of a time-dependent real-space Kubo approach in honeycomb lattices containing millions of carbon atoms, capturing the linear response of realistic size systems in the highly disordered regime. Our numerical calculations are complemented...... with the Kubo calculations. In the strong scattering regime, the conductivity is found to be a sublinear function of electronic density and weakly dependent on the Thomas-Fermi screening wavelength. We attribute this atypical behavior to the extended nature of one-dimensional charged defects. Our results...

  11. Ionic charge transport between blockages: Sodium cation conduction in freshly excised bulk brain tissue

    Energy Technology Data Exchange (ETDEWEB)

    Emin, David, E-mail: emin@unm.edu [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States); Akhtari, Massoud [Semple Institutes for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095 (United States); Ellingson, B. M. [Department of Radiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095 (United States); Mathern, G. W. [Department of Neurosurgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095 (United States)

    2015-08-15

    We analyze the transient-dc and frequency-dependent electrical conductivities between blocking electrodes. We extend this analysis to measurements of ions’ transport in freshly excised bulk samples of human brain tissue whose complex cellular structure produces blockages. The associated ionic charge-carrier density and diffusivity are consistent with local values for sodium cations determined non-invasively in brain tissue by MRI (NMR) and diffusion-MRI (spin-echo NMR). The characteristic separation between blockages, about 450 microns, is very much shorter than that found for sodium-doped gel proxies for brain tissue, >1 cm.

  12. Charge Transport in Metal-Molecule-Metal Junctions Probed by Conducting Atomic Force Microscopy

    International Nuclear Information System (INIS)

    Lee, Min Hyung; Song, Hyunwook

    2013-01-01

    We have demonstrated a proof of intrinsic charge transport properties in alkanedithiol molecular junctions using a multiprobe approach combining a variety of transport techniques. The temperature-independent I(V) behavior and the correct exponential decay of conductance with respect to molecular length shows that the dominant charge transport mechanism is off-resonant tunneling. Length-dependent TVS measurements for the saturated alkane-dithiol series indicate that we did indeed probe a molecular system with CAFM. These results can provide stringent criteria to establish a valid molecular transport junction via a probabilistic measurement technique. In this study, we report a study of charge transport in alkanedithiol SAMs formed in metal-molecule-metal junctions using CAFM in combination with a variety of molecular transport techniques including temperature-and length-variable transport measurements and transition voltage spectroscopy. The main goal of this study is to probe the intrinsic transport properties of component molecules using CAFM, but not parasitic or defect-related effects

  13. A charge transfer complex nematic liquid crystalline gel with high electrical conductivity

    International Nuclear Information System (INIS)

    Bhargavi, R.; Nair, Geetha G.; Krishna Prasad, S.; Majumdar, R.; Bag, Braja G.

    2014-01-01

    We describe the rheological, dielectric and elastic properties of a nematic liquid crystal gel created using an anthrylidene derivative of arjunolic acid, a chiral triterpenoid, obtained from the extracts of the wood of Terminalia arjuna. In this novel gel, having the electron-donor and acceptor components as minority constituents, the gelation and strengthening of charge-transfer complex (CTC) formation are seen to be occurring concomitantly. In addition to being mechanically strong with a large storage modulus, the gel with the maximized CTC exhibits Frank bend elastic constant values that approach nanonewton levels. The highlight of the study is the observation of 4–5 orders of magnitude increase in electrical conductivity for this gel, a value that is higher than even in the CT complexes of 2-d ordered columnar structures. A further important advantage of the present system over the columnar complex is that the high conductivity is seen for ac probing also, and owing to the nematic nature can be switched between its anisotropic limits. Some of these features are ascribed to a specific molecular packing architecture, which reduces the trapping of the charge carriers.

  14. A charge transfer complex nematic liquid crystalline gel with high electrical conductivity

    Science.gov (United States)

    Bhargavi, R.; Nair, Geetha G.; Krishna Prasad, S.; Majumdar, R.; Bag, Braja G.

    2014-10-01

    We describe the rheological, dielectric and elastic properties of a nematic liquid crystal gel created using an anthrylidene derivative of arjunolic acid, a chiral triterpenoid, obtained from the extracts of the wood of Terminalia arjuna. In this novel gel, having the electron-donor and acceptor components as minority constituents, the gelation and strengthening of charge-transfer complex (CTC) formation are seen to be occurring concomitantly. In addition to being mechanically strong with a large storage modulus, the gel with the maximized CTC exhibits Frank bend elastic constant values that approach nanonewton levels. The highlight of the study is the observation of 4-5 orders of magnitude increase in electrical conductivity for this gel, a value that is higher than even in the CT complexes of 2-d ordered columnar structures. A further important advantage of the present system over the columnar complex is that the high conductivity is seen for ac probing also, and owing to the nematic nature can be switched between its anisotropic limits. Some of these features are ascribed to a specific molecular packing architecture, which reduces the trapping of the charge carriers.

  15. Trap assisted space charge conduction in p-NiO/n-ZnO heterojunction diode

    International Nuclear Information System (INIS)

    Tyagi, Manisha; Tomar, Monika; Gupta, Vinay

    2015-01-01

    Highlights: • p-NiO/n-ZnO heterojunction diode with enhanced junction parameters has been prepared. • Temperature dependent I–V throw insight into the involved conduction mechanism. • SCLC with exponential trap distribution was found to be the dominant mechanism. • C–V measurement at different frequencies support the presence of traps. - Abstract: The development of short-wavelength p–n junction is essentially important for the realization of transparent electronics for next-generation optoelectronic devices. In the present work, a p–n heterojunction diode based on p-NiO/n-ZnO has been prepared under the optimised growth conditions exhibiting improved electrical and junction parameters. The fabricated heterojunction gives typical current–voltage (I–V) characteristics with good rectifying behaviour (rectification ratio ≈ 10 4 at 2 V). The temperature dependent current–voltage characteristics of heterojunction diode have been studied and origin of conduction mechanism is identified. The space-charge limited conduction with exponential trap distribution having deep level trap is found to be the dominant conduction mechanism in the fabricated p–n heterojunction diode. The conduction and valence band discontinuities for NiO/ZnO heterostructure have been determined from the capacitance–voltage (C–V) measurements

  16. Trap assisted space charge conduction in p-NiO/n-ZnO heterojunction diode

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Manisha [Department of Physics and Astrophysics, University of Delhi, Delhi-110007 (India); Tomar, Monika [Physics department, Miranda House, University of Delhi, Delhi-110007 (India); Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi-110007 (India)

    2015-06-15

    Highlights: • p-NiO/n-ZnO heterojunction diode with enhanced junction parameters has been prepared. • Temperature dependent I–V throw insight into the involved conduction mechanism. • SCLC with exponential trap distribution was found to be the dominant mechanism. • C–V measurement at different frequencies support the presence of traps. - Abstract: The development of short-wavelength p–n junction is essentially important for the realization of transparent electronics for next-generation optoelectronic devices. In the present work, a p–n heterojunction diode based on p-NiO/n-ZnO has been prepared under the optimised growth conditions exhibiting improved electrical and junction parameters. The fabricated heterojunction gives typical current–voltage (I–V) characteristics with good rectifying behaviour (rectification ratio ≈ 10{sup 4} at 2 V). The temperature dependent current–voltage characteristics of heterojunction diode have been studied and origin of conduction mechanism is identified. The space-charge limited conduction with exponential trap distribution having deep level trap is found to be the dominant conduction mechanism in the fabricated p–n heterojunction diode. The conduction and valence band discontinuities for NiO/ZnO heterostructure have been determined from the capacitance–voltage (C–V) measurements.

  17. Effect of static charge fluctuations on the conduction along the edge of two-dimensional topological insulator

    Science.gov (United States)

    Vayrynen, Jukka; Goldstein, Moshe; Glazman, Leonid

    2013-03-01

    Static charge disorder may create electron puddles in the bulk of a material which nominally is in the insulating state. A single puddle - quantum dot - coupled to the helical edge of a two-dimensional topological insulator enhances the electron backscattering within the edge. The backscattering rate increases with the electron dwelling time in the dot. While remaining inelastic, the backscattering off a dot may be far more effective than the proposed earlier inelastic processes involving a local scatterer with no internal structure. We find the temperature dependence of the dot-induced correction to the universal conductance of the edge. In addition to the single-dot effect, we calculate the classical temperature-independent conductance correction caused by a weakly conducting bulk. We use our theory to assess the effect of static charge fluctuations in a heterostructure on the edge electron transport in a two-dimensional topological insulator. The work at Yale University is supported by NSF DMR Grant No. 1206612 and the Simons Foundation.

  18. Charging/discharging processes in nanocrystaline MOS structures - Theoretical study

    International Nuclear Information System (INIS)

    Tanous, D; Mazurak, A; Majkusiak, B

    2016-01-01

    We present the study of impact of some parameters of the metal-insulator-semiconductor structure with nanocrystals embedded in the insulator layer on the current-voltage and capacitance-voltage characteristics with the bias voltage ramp rate as a parameter. The developed model is used as a tool for theoretical understanding the physics behind charging and discharging processes in the considered structures. (paper)

  19. Process techniques of charge transfer time reduction for high speed CMOS image sensors

    International Nuclear Information System (INIS)

    Cao Zhongxiang; Li Quanliang; Han Ye; Qin Qi; Feng Peng; Liu Liyuan; Wu Nanjian

    2014-01-01

    This paper proposes pixel process techniques to reduce the charge transfer time in high speed CMOS image sensors. These techniques increase the lateral conductivity of the photo-generated carriers in a pinned photodiode (PPD) and the voltage difference between the PPD and the floating diffusion (FD) node by controlling and optimizing the N doping concentration in the PPD and the threshold voltage of the reset transistor, respectively. The techniques shorten the charge transfer time from the PPD diode to the FD node effectively. The proposed process techniques do not need extra masks and do not cause harm to the fill factor. A sub array of 32 × 64 pixels was designed and implemented in the 0.18 μm CIS process with five implantation conditions splitting the N region in the PPD. The simulation and measured results demonstrate that the charge transfer time can be decreased by using the proposed techniques. Comparing the charge transfer time of the pixel with the different implantation conditions of the N region, the charge transfer time of 0.32 μs is achieved and 31% of image lag was reduced by using the proposed process techniques. (semiconductor devices)

  20. Charge-transfer mobility and electrical conductivity of PANI as conjugated organic semiconductors.

    Science.gov (United States)

    Zhang, Yahong; Duan, Yuping; Song, Lulu; Zheng, Daoyuan; Zhang, Mingxing; Zhao, Guangjiu

    2017-09-21

    The intramolecular charge transfer properties of a phenyl-end-capped aniline tetramer (ANIH) and a chloro-substituted derivative (ANICl) as organic semiconductors were theoretically studied through the first-principles calculation based on the Marcus-Hush theory. The reorganization energies, intermolecular electronic couplings, angular resolution anisotropic mobilities, and density of states of the two crystals were evaluated. The calculated results demonstrate that both ANIH and ANICl crystals show the higher electron transfer mobilities than the hole-transfer mobilities, which means that the two crystals should prefer to function as n-type organic semiconductors. Furthermore, the angle dependence mobilities of the two crystals show remarkable anisotropic character. The maximum mobility μ max of ANIH and ANICl crystals is 1.3893 and 0.0272 cm 2 V -1 s -1 , which appear at the orientation angles near 176°/356° and 119°/299° of a conducting channel on the a-b reference plane. It is synthetically evaluated that the ANIH crystal possesses relatively lower reorganization energy, higher electronic coupling, and electron transfer mobility, which means that the ANIH crystal may be the more ideal candidate as a high performance n-type organic semiconductor material. The systematic theoretical studies on organic crystals should be conducive to evaluating the charge-transport properties and designing higher performance organic semiconductor materials.

  1. Induced charge electrophoresis of a conducting cylinder in a nonconducting cylindrical pore and its micromotoring application

    Science.gov (United States)

    Feng, Huicheng; Wong, Teck Neng; Che, Zhizhao

    2016-08-01

    Induced charge electrophoresis of a conducting cylinder suspended in a nonconducting cylindrical pore is theoretically analyzed and a micromotor is proposed that utilizes the cylinder rotation. The cylinder velocities are analytically obtained in the Dirichlet and the Neumann boundary conditions of the electric field on the cylindrical pore. The results show that the cylinder not only translates but also rotates when it is eccentric with respect to the cylindrical pore. The influences of a number of parameters on the cylinder velocities are characterized in detail. The cylinder trajectories show that the cylinder approaches and becomes stationary at certain positions within the cylindrical pore. The proposed micromotor is capable of working under a heavy load with a high rotational velocity when the eccentricity is large and the applied electric field is strong.

  2. Diagram representations of charge pumping processes in CMOS transistors

    International Nuclear Information System (INIS)

    Huang Xinyun; Jiao Guangfan; Cao Wei; Huang Darning; Li Mingfu; Shen Chen

    2010-01-01

    A diagram representation method is proposed to interpret the complicated charge pumping (CP) processes. The fast and slow traps in CP measurement are defined. Some phenomena such as CP pulse rise/fall time dependence, frequency dependence, the voltage dependence for the fast and slow traps, and the geometric CP component are clearly illustrated at a glance by the diagram representation. For the slow trap CP measurement, there is a transition stage and a steady stage due to the asymmetry of the electron and hole capture, and the CP current is determined by the lower capturing electron or hole component. The method is used to discuss the legitimacy of the newly developed modified charge pumping method. (semiconductor devices)

  3. Generation of conductivity through transfer charge properties, for polyesters and polyamides with characteristic functional groups

    Science.gov (United States)

    Gonzalez, Carmen; Tagle, Luis Hernan; Terraza, Claudio A.; Barriga, Andres; Cabrera, A. L.; Volkmann, Ulrich G.

    2011-03-01

    Electro-optic properties of σ -conjugated polymers, as polysilylene; are associated with electron conjugation in the silicon atom, which allows a significant delocalization of electrons along of the chain. Thus, the conductivity is intimately connected to the mobility of charge carriers, which in turn depends on the structure and morphology of the system. We report the characterization of polyesters (PEFs) and polyamides (PAFs). Film thicknesses were obtained by ellipsometry. The vibration frequencies of the groups were determined by FT-IR and corroborated by Raman spectroscopy. Structural information was obtained from X-Ray diffraction (XRD). The structural and surface morphology were studied by scanning electron microscope (SEM). Electrical conductivity of the polymers was measured before and after exposure to iodine vapor, for films of different thicknesses. Morphological differentiation was studied by energy dispersive microscopy (EDX), showing a regular distribution of iodine within the polymer. Preliminary conductivity measurements showed adverse effects when oxidation of the polymer films is induced These effects are related to a certain grade of disorder within the system

  4. Determining the quark charges by one and two photon processes

    International Nuclear Information System (INIS)

    Janah, A.

    1982-01-01

    Testable predictions are presented, which may be used to decide between the gauge theories of integer and fractionally charged quarks (icq and fcq). Two distinctive features of icq are exploited, namely (a) presence of color non-singlet components in weak and electromagnetic currents and (b) possible liberation of color non-singlet states above a threshold energy. Consequences are sought in lepton-hadron interaction processes, taking into account the known color-suppression effect. Single photon/weak-boson processes such as nuN → nuX distinguish between icq and fcq only above color-threshold. Experimental consequences of color-liberation in the above process are obtained. It is found that the gluon-parton contribution survives color-suppression to produce a significant rise in the structure functions when color-threshold is exceeded. Two-photon processes such as e + e - → e + e - + 2 jets distinguish between the two theories even below color threshold. To obtain the icq predictions for this process, one must take into account (a) the (momentum-dependent) color suppression and (b) the added contribution from pair production of charged gluons

  5. Effect of trap states and microstructure on charge carrier conduction mechanism through semicrystalline poly(vinyl alcohol) granular film

    Science.gov (United States)

    Das, A. K.; Bhowmik, R. N.; Meikap, A. K.

    2018-05-01

    We report a comprehensive study on hysteresis behaviour of current-voltage characteristic and impedance spectroscopy of granular semicrystalline poly(vinyl alcohol) (PVA) film. The charge carrier conduction mechanism and charge traps of granular PVA film by measuring and analyzing the temperature dependent current-voltage characteristic indicate a bi-stable electronic state in the film. A sharp transformation of charge carrier conduction mechanism from Poole-Frenkel emission to space charge limited current mechanism has been observed. An anomalous oscillatory behaviour of current has been observed due to electric pulse effect on the molecular chain of the polymer. Effect of microstructure on charge transport mechanism has been investigated from impedance spectroscopy analysis. An equivalent circuit model has been proposed to explain the result.

  6. Integer Charge Transfer and Hybridization at an Organic Semiconductor/Conductive Oxide Interface

    KAUST Repository

    Gruenewald, Marco; Schirra, Laura K.; Winget, Paul; Kozlik, Michael; Ndione, Paul F.; Sigdel, Ajaya K.; Berry, Joseph J.; Forker, Roman; Bredas, Jean-Luc; Fritz, Torsten; Monti, Oliver L. A.

    2015-01-01

    with localized states (the shallow donors) in the substrate and charge back-donation, resulting in an effectively integer charge transfer across the interface. Charge transfer is thus not merely a question of locating the Fermi level above the PTCDA electron

  7. Non-Contact Conductivity Measurement for Automated Sample Processing Systems

    Science.gov (United States)

    Beegle, Luther W.; Kirby, James P.

    2012-01-01

    A new method has been developed for monitoring and control of automated sample processing and preparation especially focusing on desalting of samples before analytical analysis (described in more detail in Automated Desalting Apparatus, (NPO-45428), NASA Tech Briefs, Vol. 34, No. 8 (August 2010), page 44). The use of non-contact conductivity probes, one at the inlet and one at the outlet of the solid phase sample preparation media, allows monitoring of the process, and acts as a trigger for the start of the next step in the sequence (see figure). At each step of the muti-step process, the system is flushed with low-conductivity water, which sets the system back to an overall low-conductivity state. This measurement then triggers the next stage of sample processing protocols, and greatly minimizes use of consumables. In the case of amino acid sample preparation for desalting, the conductivity measurement will define three key conditions for the sample preparation process. First, when the system is neutralized (low conductivity, by washing with excess de-ionized water); second, when the system is acidified, by washing with a strong acid (high conductivity); and third, when the system is at a basic condition of high pH (high conductivity). Taken together, this non-contact conductivity measurement for monitoring sample preparation will not only facilitate automation of the sample preparation and processing, but will also act as a way to optimize the operational time and use of consumables

  8. Theoretical studies of optics and charge transport in organic conducting oligomers and polymers: Rational design of improved transparent and conducting polymers

    Science.gov (United States)

    Hutchison, Geoffrey Rogers

    Theoretical studies on a variety of oligo- and polyheterocycles elucidate their optical and charge transport properties, suggesting new, improved transparent conductive polymers. First-principles calculations provide accurate methodologies for predicting both optical band gaps of neutral and cationic oligomers and intrinsic charge transfer rates. Multidimensional analysis reveals important motifs in chemical tailorability of oligoheterocycle optical and charge transport properties. The results suggest new directions for design of novel materials. Using both finite oligomer and infinite polymer calculations, the optical band gaps in polyheterocycles follow a modified particle-in-a-box formalism, scaling approximately as 1/N (where N is the number of monomer units) in short chains, saturating for long chains. Calculations demonstrate that band structure changes upon heteroatom substitution, (e.g., from polythiophene to polypyrrole) derive from heteroatom electron affinity. Further investigation of chemical variability in substituted oligoheterocycles using multidimensional statistics reveals the interplay between heteroatom and substituent in correlations between structure and redox/optical properties of neutral and cationic species. A linear correlation between band gaps of neutral and cationic species upon oxidation of conjugated oligomers, shows redshifts of optical absorption for most species and blueshifts for small band gap species. Interstrand charge-transport studies focus on two contributors to hopping-style charge transfer rates: internal reorganization energy and the electronic coupling matrix element. Statistical analysis of chemical variability of reorganization energies in oligoheterocycles proves the importance of reorganization energy in determining intrinsic charge transfer rates (e.g., charge mobility in unsubstituted oligothiophenes). Computed bandwidths across several oligothiophene crystal packing motifs show similar electron and hole bandwidths

  9. Deposition and post-processing techniques for transparent conductive films

    Energy Technology Data Exchange (ETDEWEB)

    Christoforo, Mark Greyson; Mehra, Saahil; Salleo, Alberto; Peumans, Peter

    2017-07-04

    In one embodiment, a method is provided for fabrication of a semitransparent conductive mesh. A first solution having conductive nanowires suspended therein and a second solution having nanoparticles suspended therein are sprayed toward a substrate, the spraying forming a mist. The mist is processed, while on the substrate, to provide a semitransparent conductive material in the form of a mesh having the conductive nanowires and nanoparticles. The nanoparticles are configured and arranged to direct light passing through the mesh. Connections between the nanowires provide conductivity through the mesh.

  10. Electron-molecule chemistry and charging processes on organic ices and Titan's icy aerosol surrogates

    Science.gov (United States)

    Pirim, C.; Gann, R. D.; McLain, J. L.; Orlando, T. M.

    2015-09-01

    Electron-induced polymerization processes and charging events that can occur within Titan's atmosphere or on its surface were simulated using electron irradiation and dissociative electron attachment (DEA) studies of nitrogen-containing organic condensates. The DEA studies probe the desorption of H- from hydrogen cyanide (HCN), acetonitrile (CH3CN), and aminoacetonitrile (NH2CH2CN) ices, as well as from synthesized tholin materials condensed or deposited onto a graphite substrate maintained at low temperature (90-130 K). The peak cross sections for H- desorption during low-energy (3-15 eV) electron irradiation were measured and range from 3 × 10-21 to 2 × 10-18 cm2. Chemical and structural transformations of HCN ice upon 2 keV electron irradiation were investigated using X-ray photoelectron and Fourier-transform infrared spectroscopy techniques. The electron-beam processed materials displayed optical properties very similar to tholins produced by conventional discharge methods. Electron and negative ion trapping lead to 1011 charges cm-2 on a flat surface which, assuming a radius of 0.05 μm for Titan aerosols, is ∼628 charges/radius (in μm). The facile charge trapping indicates that electron interactions with nitriles and complex tholin-like molecules could affect the conductivity of Titan's atmosphere due to the formation of large negative ion complexes. These negatively charged complexes can also precipitate onto Titan's surface and possibly contribute to surface reactions and the formation of dunes.

  11. Theoretical and practical implications on the subjects charged with duties of conducting special investigation activity

    Directory of Open Access Journals (Sweden)

    Obadă Dumitru

    2017-10-01

    Full Text Available This paper is an endeavor to analyze Moldova’s legal framework aimed at regulating Special investigative activity (SIA in terms of subjects or, in other words, of procedural exponents, invested by a legislator with duties of carrying out SIM. It is also an attempt to reveal the normative inconsistencies specified in the regulatory content of the Criminal Procedural Law, including a verifiable analysis of the legal norms stipulated in the Code of Criminal Procedure, as well as other regulations related to this specific area of state activity specified in the related legislation. Moreover, the author sought to highlight the adverse legal effects that may be generated by the misinterpretation and misapplication of the legal norms related to SIA. While carrying out this study, we have taken into account the practice of law enforcement by state bodies in conducting criminal investigations, as well as the attempt to clarify and define the concept of “carrying out special investigative activity”. The research is also an attempt to clarify the competences of procedural subjects in charge of conducting SIA, as well as their functional interdependence in this activity. Furthermore, the study reasons upon some author’s assertions regarding the legal nature of SIM results from the perspective of the theory of evidence, particularly the admissibility of evidence obtained through SIM, the procedural stage at which the SIM can be performed, the impact of the current normative inadvertences regarding the possibility of taking evidence by means of SIM. The research has also been focused on identifying the prosecutor’s functional characteristics in conducting special investigative activity.

  12. Strong-field relativistic processes in highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Postavaru, Octavian

    2010-12-08

    In this thesis we investigate strong-field relativistic processes in highly charged ions. In the first part, we study resonance fluorescence of laser-driven highly charged ions in the relativistic regime by solving the time-dependent master equation in a multi-level model. Our ab initio approach based on the Dirac equation allows for investigating highly relativistic ions, and, consequently, provides a sensitive means to test correlated relativistic dynamics, bound-state quantum electrodynamic phenomena and nuclear effects by applying coherent light with x-ray frequencies. Atomic dipole or multipole moments may be determined to unprecedented accuracy by measuring the interference-narrowed fluorescence spectrum. Furthermore, we investigate the level structure of heavy hydrogenlike ions in laser beams. Interaction with the light field leads to dynamic shifts of the electronic energy levels, which is relevant for spectroscopic experiments. We apply a fully relativistic description of the electronic states by means of the Dirac equation. Our formalism goes beyond the dipole approximation and takes into account non-dipole effects of retardation and interaction with the magnetic field components of the laser beam. We predicted cross sections for the inter-shell trielectronic recombination (TR) and quadruelectronic recombination processes which have been experimentally confirmed in electron beam ion trap measurements, mainly for C-like ions, of Ar, Fe and Kr. For Kr{sup 30}+, inter-shell TR contributions of nearly 6% to the total resonant photorecombination rate were found. (orig.)

  13. Effect of normal processes on thermal conductivity of germanium ...

    Indian Academy of Sciences (India)

    Abstract. The effect of normal scattering processes is considered to redistribute the phonon momentum in (a) the same phonon branch – KK-S model and (b) between differ- ent phonon branches – KK-H model. Simplified thermal conductivity relations are used to estimate the thermal conductivity of germanium, silicon and ...

  14. Charge state analysis of heavy ions after penetration of uncleaned and sputter cleaned conducting surfaces

    International Nuclear Information System (INIS)

    Jung, M.; Schosnig, M.; Kroneberger, K.; Tobisch, M.; Maier, R.; Kuzel, M.; Fiedler, C.; Hofmann, D.; Groeneveld, K.O.

    1994-01-01

    The evolution of the charge state distribution of fast ions inside a solid is of basic interest in various research fields as stopping power measurements etc. The existing models for the charge state evolution differ in the treatment of the projectile-exit-surface interaction, which has a strong influence on the final charge state distributions. We measured the charge state distributions for C + , N + , and O + (30≤E/M≤130 keV/u) impact on thin C, Cu, and Au foils, where the surface properties were modified by sputter cleaning. The mesurements show a pronounced change of the mean projectile charge state to lower values in the case of sputter cleaned surfaces. This result underlines the importance of the projectile-surface interaction for the generation of the outcoming charge state distribution. (orig.)

  15. Two-photon processes in highly charged ions

    International Nuclear Information System (INIS)

    Jahrsetz, Thorsten

    2015-01-01

    Two-photon processes are atomic processes in which an atom interacts simultaneously with two photons. Such processes describe a wide range of phenomena, such as two-photon decay and elastic or inelastic scattering of photons. In recent years two-photon processes involving highly charged heavy ions have become an active area of research. Such studies do not only consider the total transition or scattering rates but also their angular and polarization dependence. To support such examinations in this thesis I present a theoretical framework to describe these properties in all two-photon processes with bound initial and final states and involving heavy H-like or He-like ions. I demonstrate how this framework can be used in some detailed studies of different two-photon processes. Specifically a detailed analysis of two-photon decay of H-like and He-like ions in strong external electromagnetic fields shows the importance of considering the effect of such fields for the physics of such systems. Furthermore I studied the elastic Rayleigh as well as inelastic Raman scattering by heavy H-like ions. I found a number of previously unobserved phenomena in the angular and polarization dependence of the scattering cross-sections that do not only allow to study interesting details of the electronic structure of the ion but might also be useful for the measurement of weak physical effects in such systems.

  16. Two-photon processes in highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Jahrsetz, Thorsten

    2015-03-05

    Two-photon processes are atomic processes in which an atom interacts simultaneously with two photons. Such processes describe a wide range of phenomena, such as two-photon decay and elastic or inelastic scattering of photons. In recent years two-photon processes involving highly charged heavy ions have become an active area of research. Such studies do not only consider the total transition or scattering rates but also their angular and polarization dependence. To support such examinations in this thesis I present a theoretical framework to describe these properties in all two-photon processes with bound initial and final states and involving heavy H-like or He-like ions. I demonstrate how this framework can be used in some detailed studies of different two-photon processes. Specifically a detailed analysis of two-photon decay of H-like and He-like ions in strong external electromagnetic fields shows the importance of considering the effect of such fields for the physics of such systems. Furthermore I studied the elastic Rayleigh as well as inelastic Raman scattering by heavy H-like ions. I found a number of previously unobserved phenomena in the angular and polarization dependence of the scattering cross-sections that do not only allow to study interesting details of the electronic structure of the ion but might also be useful for the measurement of weak physical effects in such systems.

  17. Optimization of white organic light emitting diodes based on emitting layer charge carrier conduction properties

    International Nuclear Information System (INIS)

    Baek, H I; Lee, C H

    2008-01-01

    We have fabricated white organic light emitting diodes (OLEDs) with multi-emitting layer (EML) structures in which 4,4'-N,N'-dicarbazole-biphenyl (CBP) layers doped with the phosphorescent dopants fac-tris(2-phenylpyridine) iridium (Ir(ppy) 3 ) and bis(2-(2'-benzo[4,5-a]thienyl)pyridinato-N,C3')iridium(acetylacetonate) (btp 2 Ir(acac)) and the fluorescent dopant 4,4'-bis[2-{4-(N,N-diphenylamino) phenyl}vinyl]biphenyl (DPAVBi) were used as green (G), red (R) and blue (B) EMLs, respectively. A higher efficiency was expected with the R/G/B EML sequence from the hole transport layer interface than with the G/R/B sequence because of the differences in the charge carrier conduction properties of the EMLs doped with phosphorescent dopants and the luminance balance between the phosphorescent and fluorescent emissions. A high efficiency of 18.3 cd A -1 (an external quantum efficiency of 8.5%) at 100 cd m -2 and good colour stability were achieved with the R/G/B EML sequence as expected, with an additional non-doped CBP interlayer used between the G and B EMLs. In addition, the OLED with this sequence was found to have the longest lifetime of the white devices we tested

  18. Optimization of white organic light emitting diodes based on emitting layer charge carrier conduction properties

    Energy Technology Data Exchange (ETDEWEB)

    Baek, H I; Lee, C H [School of Electrical Engineering and Computer Science and Inter-University Semiconductor Research Center, Seoul National University, Seoul 151-744 (Korea, Republic of)], E-mail: hibaek75@snu.ac.kr

    2008-05-21

    We have fabricated white organic light emitting diodes (OLEDs) with multi-emitting layer (EML) structures in which 4,4'-N,N'-dicarbazole-biphenyl (CBP) layers doped with the phosphorescent dopants fac-tris(2-phenylpyridine) iridium (Ir(ppy){sub 3}) and bis(2-(2'-benzo[4,5-a]thienyl)pyridinato-N,C3')iridium(acetylacetonate) (btp{sub 2}Ir(acac)) and the fluorescent dopant 4,4'-bis[2-{l_brace}4-(N,N-diphenylamino) phenyl{r_brace}vinyl]biphenyl (DPAVBi) were used as green (G), red (R) and blue (B) EMLs, respectively. A higher efficiency was expected with the R/G/B EML sequence from the hole transport layer interface than with the G/R/B sequence because of the differences in the charge carrier conduction properties of the EMLs doped with phosphorescent dopants and the luminance balance between the phosphorescent and fluorescent emissions. A high efficiency of 18.3 cd A{sup -1} (an external quantum efficiency of 8.5%) at 100 cd m{sup -2} and good colour stability were achieved with the R/G/B EML sequence as expected, with an additional non-doped CBP interlayer used between the G and B EMLs. In addition, the OLED with this sequence was found to have the longest lifetime of the white devices we tested.

  19. Process for fabricating composite material having high thermal conductivity

    Science.gov (United States)

    Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

    2001-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  20. Transparent and Electrically Conductive Carbon Nanotube-Polymer Nanocomposite Materials for Electrostatic Charge Dissipation

    Science.gov (United States)

    Dervishi, E.; Biris, A. S.; Biris, A. R.; Lupu, D.; Trigwell, S.; Miller, D. W.; Schmitt, T.; Buzatu, D. A.; Wilkes, J. G.

    2006-01-01

    In recent years, nanocomposite materials have been extensively studied because of their superior electrical, magnetic, and optical properties and large number of possible applications that range from nano-electronics, specialty coatings, electromagnetic shielding, and drug delivery. The aim of the present work is to study the electrical and optical properties of carbon nanotube(CNT)-polymer nanocomposite materials for electrostatic charge dissipation. Single and multi-wall carbon nanotubes were grown by catalytic chemical vapor deposition (CCVD) on metal/metal oxide catalytic systems using acetylene or other hydrocarbon feedstocks. After the purification process, in which amorphous carbon and non-carbon impurities were removed, the nanotubes were functionalized with carboxylic acid groups in order to achieve a good dispersion in water and various other solvents. The carbon nanostructures were analyzed, both before and after functionalization by several analytical techniques, including microscopy, Raman spectroscopy, and X-Ray photoelectron spectroscopy. Solvent dispersed nanotubes were mixed (1 to 7 wt %) into acrylic polymers by sonication and allowed to dry into 25 micron thick films. The electrical and optical properties of the films were analyzed as a function of the nanotubes' concentration. A reduction in electrical resistivity, up to six orders of magnitude, was measured as the nanotubes' concentration in the polymeric films increased, while optical transparency remained 85 % or higher relative to acrylic films without nanotubes.

  1. Theoretical assessment of the disparity in the electrostatic forces between two point charges and two conductive spheres of equal radii

    Science.gov (United States)

    Kolikov, Kiril

    2016-11-01

    The Coulomb's formula for the force FC of electrostatic interaction between two point charges is well known. In reality, however, interactions occur not between point charges, but between charged bodies of certain geometric form, size and physical structure. This leads to deviation of the estimated force FC from the real force F of electrostatic interaction, thus imposing the task to evaluate the disparity. In the present paper the problem is being solved theoretically for two charged conductive spheres of equal radii and arbitrary electric charges. Assessment of the deviation is given as a function of the ratio of the distance R between the spheres centers to the sum of their radii. For the purpose, relations between FC and F derived in a preceding work of ours, are employed to generalize the Coulomb's interactions. At relatively short distances between the spheres, the Coulomb force FC, as estimated to be induced by charges situated at the centers of the spheres, differ significantly from the real force F of interaction between the spheres. In the case of zero and non-zero charge we prove that with increasing the distance between the two spheres, the force F decrease rapidly, virtually to zero values, i.e. it appears to be short-acting force.

  2. Irreversibility and Action of the Heat Conduction Process

    Directory of Open Access Journals (Sweden)

    Yu-Chao Hua

    2018-03-01

    Full Text Available Irreversibility (that is, the “one-sidedness” of time of a physical process can be characterized by using Lyapunov functions in the modern theory of stability. In this theoretical framework, entropy and its production rate have been generally regarded as Lyapunov functions in order to measure the irreversibility of various physical processes. In fact, the Lyapunov function is not always unique. In the represent work, a rigorous proof is given that the entransy and its dissipation rate can also serve as Lyapunov functions associated with the irreversibility of the heat conduction process without the conversion between heat and work. In addition, the variation of the entransy dissipation rate can lead to Fourier’s heat conduction law, while the entropy production rate cannot. This shows that the entransy dissipation rate, rather than the entropy production rate, is the unique action for the heat conduction process, and can be used to establish the finite element method for the approximate solution of heat conduction problems and the optimization of heat transfer processes.

  3. Processable Conducting Polyaniline, Carbon Nanotubes, Graphene and Their Composites

    Science.gov (United States)

    Wang, Kan

    Good processability is often required for applications of conducting materials like polyaniline (PANI), carbon nanotubes (CNTs) and graphene. This can be achieved by either physical stabilization or chemical functionalization. Functionalization usually expands the possible applications for the conducting materials depending on the properties of the functional groups. Processable conducting materials can also be combined with other co-dissolving materials to prepare composites with desired chemical and physical properties. Polyanilines (PANI) doped with dodecylbenzenesulfonic acid (DBSA) are soluble in many organic solvents such as chloroform and toluene. Single wall carbon nanotubes (SWCNTs) can be dispersed into PANI/DBSA to form homogeneous solutions. PANI/DBSA functions as a conducting surfactant for SWCNTs. The mixture can be combined with two-parts polyurethanes that co-dissolve in the organic solvent to produce conducting polymer composites. The composite mixtures can be applied onto various substrates by simple spray-on methods to obtain transparent and conducting coatings. Graphene, a single layer of graphite, has drawn intense interest for its unique properties. Processable graphene has been produced in N-methyl-2-pyrrolidone (NMP) by a one-step solvothermal reduction of graphite oxide without the aid of any reducing reagent and/or surfactant. The as-synthesized graphene disperses well in a variety of organic solvents such as dimethylsulfoxide (DMSO), ethanol and tetrahydrogenfuran (THF). The conductivity of solvothermal reduced graphite oxide is comparable to hydrazine reduced graphite oxide. Attempts were made to create intrinsically conducting glue comparable to mussel adhesive protiens using polyaniline and graphene. Mussels can attach to a variety of substrates under water. Catechol residue in 3,4-dihydroxyphenylalanine (L-DOPA) is the key to the wet adhesion. Tyrosine and phosphoserine with primary alkyl amine groups also participate in adhesion. A

  4. Open Access, Library Subscriptions, and Article Processing Charges

    KAUST Repository

    Vijayakumar, J.K.

    2016-05-01

    Hybrid journals contains articles behind a pay-wall to be subscribed, as well as papers made open access when author pays article processing charge (APC). In such cases, an Institution will end up paying twice and Publishers tend to double-dip. Discussions and pilot models are emerging on pricing options, such as “offset pricing,” [where APCs are adjusted or discounted with subscription costs as vouchers or reductions in next year subscriptions, APCs beyond the subscription costs are modestly capped etc] and thus reduce Institutions’ cost. This presentation will explain different models available and how can we attain a transparent costing structure, where the scholarly community can feel the fairness in Publishers’ pricing mechanisms. Though most of the offset systems are developed through national level or consortium level negotiations, experience of individual institutions, like KAUST that subscribe to large e-journals collections, is important in making right decisions on saving Institutes costs and support openness in scholarly communications.

  5. Open Access, Library Subscriptions, and Article Processing Charges

    KAUST Repository

    Vijayakumar, J.K.; Tamarkin, Molly

    2016-01-01

    Hybrid journals contains articles behind a pay-wall to be subscribed, as well as papers made open access when author pays article processing charge (APC). In such cases, an Institution will end up paying twice and Publishers tend to double-dip. Discussions and pilot models are emerging on pricing options, such as “offset pricing,” [where APCs are adjusted or discounted with subscription costs as vouchers or reductions in next year subscriptions, APCs beyond the subscription costs are modestly capped etc] and thus reduce Institutions’ cost. This presentation will explain different models available and how can we attain a transparent costing structure, where the scholarly community can feel the fairness in Publishers’ pricing mechanisms. Though most of the offset systems are developed through national level or consortium level negotiations, experience of individual institutions, like KAUST that subscribe to large e-journals collections, is important in making right decisions on saving Institutes costs and support openness in scholarly communications.

  6. General mechanism involved in subwavelength optics of conducting microstructures: charge-oscillation-induced light emission and interference.

    Science.gov (United States)

    Huang, Xian-Rong; Peng, Ru-Wen

    2010-04-01

    Interactions between light and conducting microstructures or nanostructures can result in a variety of novel phenomena, but their underlying mechanisms have not been completely understood. From calculations of surface charge density waves on conducting gratings and by comparing them with classical surface plasmons, we revealed a general yet concrete picture regarding the coupling of light to free electron oscillation on structured conducting surfaces that can lead to oscillating subwavelength charge patterns (i.e., structured surface plasmons). New wavelets emitted from these light sources then destructively interfere to form evanescent waves. This principle, usually combined with other mechanisms, is mainly a geometrical effect that can be universally involved in light scattering from all periodic and non-periodic structures containing free electrons. This picture may provide clear guidelines for developing conductor-based nano-optical devices.

  7. Dependence of the carrier mobility and trapped charge limited conduction on silver nanoparticles embedment in doped polypyrrole nanostructures

    Science.gov (United States)

    Biswas, Swarup; Dutta, Bula; Bhattacharya, Subhratanu

    2013-10-01

    The present article demonstrates an intensive study upon the temperature dependent current density (J)-voltage (V) characteristics of moderately doped polypyrrole nanostructure and its silver nanoparticles incorporated nanocomposites. Analysis of the measured J-V characteristics of different synthesized nano-structured samples within a wide temperature range revealed that the electrical conduction behavior followed a trapped charge-limited conduction and a transition of charge transport mechanism from deep exponential trap limited conduction to shallow traps limited conduction had been occurred due to the incorporation of silver nanoparticles within the polypyrrole matrix. A direct evaluation of carrier mobility as a function of electric field and temperature from the measured J-V characteristics illustrates that the incorporation of silver nanoparticles within the polypyrrole matrix enhances the carrier mobility at a large extent by reducing the concentration of traps within the polypyrrole matrix. The calculated mobility is consistent with the Poole-Frenkel form for the electrical field up to a certain temperature range. The nonlinear low temperature dependency of mobility of all the nanostructured samples was explained by Mott variable range hopping conduction mechanisms. Quantitative information regarding the charge transport parameters obtained from the above study would help to extend optimization strategies for the fabrication of new organic semiconducting nano-structured devices.

  8. Charging suppression in focused-ion beam fabrication of visible subwavelength dielectric grating reflector using electron conducting polymer

    KAUST Repository

    Alias, Mohd Sharizal; Liao, Hsien-Yu; Ng, Tien Khee; Ooi, Boon S.

    2015-01-01

    Nanoscale periodic patterning on insulating materials using focused-ion beam (FIB) is challenging because of charging effect, which causes pattern distortion and resolution degradation. In this paper, the authors used a charging suppression scheme using electron conducting polymer for the implementation of FIB patterned dielectric subwavelength grating (SWG) reflector. Prior to the FIB patterning, the authors numerically designed the optimal structure and the fabrication tolerance for all grating parameters (period, grating thickness, fill-factor, and low refractive index layer thickness) using the rigorous-coupled wave analysis computation. Then, the authors performed the FIB patterning on the dielectric SWG reflector spin-coated with electron conducting polymer for the anticharging purpose. They also performed similar patterning using thin conductive film anticharging scheme (30 nm Cr coating) for comparison. Their results show that the electron conducting polymer anticharging scheme effectively suppressing the charging effect during the FIB patterning of dielectric SWG reflector. The fabricated grating exhibited nanoscale precision, high uniformity and contrast, constant patterning, and complied with fabrication tolerance for all grating parameters across the entire patterned area. Utilization of electron conducting polymer leads to a simpler anticharging scheme with high precision and uniformity for FIB patterning on insulator materials.

  9. Charging suppression in focused-ion beam fabrication of visible subwavelength dielectric grating reflector using electron conducting polymer

    KAUST Repository

    Alias, Mohd Sharizal

    2015-08-19

    Nanoscale periodic patterning on insulating materials using focused-ion beam (FIB) is challenging because of charging effect, which causes pattern distortion and resolution degradation. In this paper, the authors used a charging suppression scheme using electron conducting polymer for the implementation of FIB patterned dielectric subwavelength grating (SWG) reflector. Prior to the FIB patterning, the authors numerically designed the optimal structure and the fabrication tolerance for all grating parameters (period, grating thickness, fill-factor, and low refractive index layer thickness) using the rigorous-coupled wave analysis computation. Then, the authors performed the FIB patterning on the dielectric SWG reflector spin-coated with electron conducting polymer for the anticharging purpose. They also performed similar patterning using thin conductive film anticharging scheme (30 nm Cr coating) for comparison. Their results show that the electron conducting polymer anticharging scheme effectively suppressing the charging effect during the FIB patterning of dielectric SWG reflector. The fabricated grating exhibited nanoscale precision, high uniformity and contrast, constant patterning, and complied with fabrication tolerance for all grating parameters across the entire patterned area. Utilization of electron conducting polymer leads to a simpler anticharging scheme with high precision and uniformity for FIB patterning on insulator materials.

  10. Space charge profiles in low density polyethylene samples containing a permittivity/conductivity gradient

    DEFF Research Database (Denmark)

    Bambery, K.R.; Fleming, R.J.; Holbøll, Joachim

    2001-01-01

    .5×107 V m-1. Current density was also measured as a function of temperature and field. Space charge due exclusively to the temperature gradient was detected, with density of order 0.01 C m-3. The activation energy associated with the transport of electrons through the bulk was calculated as 0.09 e...

  11. Mapping surface charge density of lipid bilayers by quantitative surface conductivity microscopy

    DEFF Research Database (Denmark)

    Klausen, Lasse Hyldgaard; Fuhs, Thomas; Dong, Mingdong

    2016-01-01

    Local surface charge density of lipid membranes influences membrane-protein interactions leading to distinct functions in all living cells, and it is a vital parameter in understanding membrane-binding mechanisms, liposome design and drug delivery. Despite the significance, no method has so far...

  12. Ab initio theory of charge-carrier conduction in ultrapure organic crystals

    NARCIS (Netherlands)

    Hannewald, K.; Bobbert, P.A.

    2004-01-01

    We present an ab initio description of charge-carrier mobilities in organic molecular crystals of high purity. Our approach is based on Holstein's original concept of small-polaron bands but generalized with respect to the inclusion of nonlocal electron-phonon coupling. By means of an explicit

  13. Conductivity rules in the Fermi and charge-spin separated liquid

    International Nuclear Information System (INIS)

    Arulsamy, Andrew Das

    2005-01-01

    Ioffe-Larkin rule applies for the pure charge-spin separation regardless of its dimensionality. Here, an extension to this rule as a result of the coexistence of spinon, holon and electron as a single entity in the 2-dimensional (2D) system is derived, which is also in accordance with the original rule

  14. Cyclic voltammetry modeling of proton transport effects on redox charge storage in conductive materials: application to a TiO2 mesoporous film.

    Science.gov (United States)

    Kim, Y S; Balland, V; Limoges, B; Costentin, C

    2017-07-21

    Cyclic voltammetry is a particularly useful tool for characterizing charge accumulation in conductive materials. A simple model is presented to evaluate proton transport effects on charge storage in conductive materials associated with a redox process coupled with proton insertion in the bulk material from an aqueous buffered solution, a situation frequently encountered in metal oxide materials. The interplay between proton transport inside and outside the materials is described using a formulation of the problem through introduction of dimensionless variables that allows defining the minimum number of parameters governing the cyclic voltammetry response with consideration of a simple description of the system geometry. This approach is illustrated by analysis of proton insertion in a mesoporous TiO 2 film.

  15. Physical processes in high field insulating liquid conduction

    Science.gov (United States)

    Mazarakis, Michael; Kiefer, Mark; Leckbee, Joshua; Anderson, Delmar; Wilkins, Frank; Obregon, Robert

    2017-10-01

    In the power grid transmission where a large amount of energy is transmitted to long distances, High Voltage DC (HVDC) transmission of up to 1MV becomes more attractive since is more efficient than the counterpart AC. However, two of the most difficult problems to solve are the cable connections to the high voltage power sources and their insulation from the ground. The insulating systems are usually composed of transformer oil and solid insulators. The oil behavior under HVDC is similar to that of a weak electrolyte. Its behavior under HVDC is dominated more by conductivity than dielectric constant. Space charge effects in the oil bulk near high voltage electrodes and impeded plastic insulators affect the voltage oil hold-off. We have constructed an experimental facility where we study the oil and plastic insulator behavior in an actual HVDC System. Experimental results will be presented and compared with the present understanding of the physics governing the oil behavior under very high electrical stresses. Sandia National Laboratories managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. D.O.E., NNSA under contract DE-NA-0003525.

  16. Influence of ionic constituents and electrical conductivity on the propagation of charged nanoscale objects in passivated gel electrophoresis.

    Science.gov (United States)

    Bikos, Dimitri A; Mason, Thomas G

    2018-01-01

    When determining the electric field E acting on charged objects in gel electrophoresis, the electrical conductivity of the buffer solution is often overlooked; E is typically calculated by dividing the applied voltage by a separation distance between electrodes. However, as a consequence of electrolytic reactions, which occur at the electrodes, gradients in the ionic content of the buffer solution and its conductivity can potentially develop over time, thereby impacting E and affecting propagation velocities of charged objects, v, directly. Here, we explore how the types and concentrations of ionic constituents of the buffer solution, which largely control its conductivity, when used in passivated gel electrophoresis (P-gelEP), can influence E, thereby altering v of charged nanospheres propagating through large-pore gels. We measure the conductivity of the buffer solution in the center of the gel region near propagating bands of nanospheres, and we show that predictions of E based on conductivity closely correlate with v. We also explore P-gelEP involving two different types of passivation agents: nonionic polyethylene glycol (PEG) and anionic sodium dodecyl sulfate (SDS). Our observations indicate that using a conductivity model to determine E from the local current density and the conductivity where spheres are propagating can lead to a better estimate than the standard approach of a voltage divided by a separation. Moreover, this conductivity model also provides a starting point for interpreting the complex behavior created by amphiphilic ionic passivation agents, such as SDS, on propagating nanospheres used in some P-gelEP experiments. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Laser Processing of Carbon Nanotube Transparent Conducting Films

    Science.gov (United States)

    Mann, Andrew

    Transparent conducting films, or TCFs, are 2D electrical conductors with the ability to transmit light. Because of this, they are used in many popular electronics including smart phones, tablets, solar panels, and televisions. The most common material used as a TCF is indium tin oxide, or ITO. Although ITO has great electrical and optical characteristics, it is expensive, brittle, and difficult to pattern. These limitations have led researchers toward other materials for the next generation of displays and touch panels. The most promising material for next generation TCFs is carbon nanotubes, or CNTs. CNTs are cylindrical tubes of carbon no more than a few atoms thick. They have different electrical and optical properties depending on their atomic structure, and are extremely strong. As an electrode, they conduct electricity through an array of randomly dispersed tubes. The array is highly transparent because of gaps between the tubes, and size and optical properties of the CNTs. Many research groups have tried making CNT TCFs with opto-electric properties similar to ITO but have difficultly achieving high conductivity. This is partly attributed to impurities from fabrication and a mix of different tube types, but is mainly caused by low junction conductivity. In functionalized nanotubes, junction conductivity is impaired by covalently bonded molecules added to the sidewalls of the tubes. The addition of this molecule, known as functionalization, is designed to facilitate CNT dispersion in a solvent by adding properties of the molecule to the CNTs. While necessary for a good solution, functionalization decreases the conductivity in the CNT array by creating defects in the tube's structures and preventing direct inter-carbon bonding. This research investigates removing the functional coating (after tube deposition) by laser processing. Laser light is able to preferentially heat the CNTs because of their optical and electrical properties. Through local conduction

  18. Thermal Conductivity Changes Due to Degradation of Cathode Film Subjected to Charge-Discharge Cycles in a Li Ion Battery

    Science.gov (United States)

    Jagannadham, K.

    2018-05-01

    A battery device with graphene platelets as anode, lithium nickel manganese oxide as cathode, and solid-state electrolyte consisting of layers of lithium phosphorous oxynitride and lithium lanthanum titanate is assembled on the stainless steel substrate. The battery in a polymer enclosure is subjected to several electrical tests consisting of charge and discharge cycles at different current and voltage levels. Thermal conductivity of the cathode layer is determined at the end of charge-discharge cycles using transient thermoreflectance. The microstructure and composition of the cathode layer and the interface between the cathode, the anode, and the electrolyte are characterized using scanning electron microscopy and elemental mapping. The decrease in the thermal conductivity of the same cathode observed after each set of electrical test cycles is correlated with the volume changes and formation of low ionic and thermal conductivity lithium oxide and lithium oxychloride at the interface and along porous regions. The interface between the metal current collector and the cathode is also found to be responsible for the increase in thermal resistance. The results indicate that changes in the thermal conductivity of the electrodes provide a measure of the resistance to heat transfer and degradation of ionic transport in the cathode accompanying the charge-discharge cycles in the batteries.

  19. Visualization of single-wall carbon nanotube (SWNT) networks in conductive polystyrene nanocomposites by charge contrast imaging

    International Nuclear Information System (INIS)

    Loos, Joachim; Alexeev, Alexander; Grossiord, Nadia; Koning, Cor E.; Regev, Oren

    2005-01-01

    The morphology of conductive nanocomposites consisting of low concentration of single-wall carbon nanotubes (SWNT) and polystyrene (PS) has been studied using atomic force microscopy (AFM), transmission electron microscopy (TEM) and, in particular, scanning electron microscopy (SEM). Application of charge contrast imaging in SEM allows visualization of the overall SWNT dispersion within the polymer matrix as well as the identification of individual or bundled SWNTs at high resolution. The contrast mechanism involved will be discussed. In conductive nanocomposites the SWNTs are homogeneously dispersed within the polymer matrix and form a network. Beside fairly straight SWNTs, strongly bended SWNTs have been observed. However, for samples with SWNT concentrations below the percolation threshold, the common overall charging behavior of an insulating material is observed preventing the detailed morphological investigation of the sample

  20. Supramolecular ionics: electric charge partition within polymers and other non-conducting solids

    Directory of Open Access Journals (Sweden)

    FERNANDO GALEMBECK

    2001-12-01

    Full Text Available Electrostatic phenomena in insulators have been known for the past four centuries, but many related questions are still unanswered, for instance: which are the charge-bearing species in an electrified organic polymer, how are the charges spatially distributed and which is the contribution of the electrically charged domains to the overall polymer properties? New scanning probe microscopies were recently introduced, and these are suitable for the mapping of electric potentials across a solid sample thus providing some answers for the previous questions. In this work, we report results obtained with two of these techniques: scanning electric potential (SEPM and electric force microscopy (EFM. These results were associated to images acquired by using analytical electron microscopy (energy-loss spectroscopy imaging in the transmission electron microscope, ESI-TEM for colloid polymer samples. Together, they show domains with excess electric charges (and potentials extending up to hundreds of nanometers and formed by large clusters of cations or anions, reaching supramolecular dimensions. Domains with excess electric charge were also observed in thermoplastics as well as in silica, polyphosphate and titanium oxide particles. In the case of thermoplastics, the origin of the charges is tentatively assigned to their tribochemistry, oxidation followed by segregation or the Mawell-Wagner-Sillars and Costa Ribeiro effects.A eletrificação de sólidos é conhecida há quatro séculos, mas há muitas questões importantes sobre este assunto, ainda não respondidas: por exemplo, quais são as espécies portadoras de cargas em um polímero isolante eletrificado, como estas cargas estão espacialmente distribuídas e qual é a contribuição destas cargas para as propriedades do polímero? Técnicas microscópicas introduzidas recentemente são apropriadas para o mapeamento de potenciais elétricos ao longo de uma superfície sólida, portanto podem responder a

  1. Disentangling surface, bulk, and space-charge-layer conductivity in Si(111)-(7x7)

    DEFF Research Database (Denmark)

    Wells, J.W.; Kallehauge, J.F.; Hansen, Torben Mikael

    2006-01-01

    A novel approach for extracting genuine surface conductivities is presented and illustrated using the unresolved example of Si(111)-(7x7). Its temperature-dependent conductivity was measured with a microscopic four point probe between room temperature and 100 K. At room temperature the measured...... conductance corresponds to that expected from the bulk doping level. However, as the temperatures is lowered below approximate to 200 K, the conductance decreases by several orders of magnitude in a small temperature range and it saturates at a low temperature value of approximate to 4x10(-8) Omega(-1...

  2. Metallic conductivity in a disordered charge-transfer salt derived from cis-BET-TTF

    Energy Technology Data Exchange (ETDEWEB)

    Rovira, C. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Tarres, J. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Ribera, E. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Veciana, J. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Canadell, E. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Molins, E. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Mas, M. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain); Laukhin, V. [Inst. de Ciencia de Materials de Barcelona (CSIC) (Spain)]|[Rossijskaya Akademiya Nauk, Chernogolovka (Russian Federation). Inst. Khimicheskoj Fiziki; Doublet, M.L. [Lab. de Structure et Dynamique (CNRS), Univ. de Montpellier 2 (France); Cowan, D.O. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Chemistry; Yang, S. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Chemistry

    1997-02-28

    The first example of a metallic charge-transfer salt derived from cis-bis(ethylenethio)-tetrathiafulvalene (BET-TTF) is reported. (BET-TTF){sub 2}SCN and (BET-TTF)SCN salts were obtained by electrocrystallization starting from trans-BET-TTF. X-ray crystal structure of the mixed-valence salt revealed that trans-cis isomerization occurs upon one electron oxidation. In spite of the structural disorder in both BET-TTF and the counterion, 2:1 salt is metallic down to 60 K and then resistance increases slowly down to 4 K. (orig.)

  3. Dysfunctional feedback processing in adolescent males with conduct disorder.

    Science.gov (United States)

    Gao, Yidian; Chen, Haiyan; Jia, Huiqiao; Ming, Qingsen; Yi, Jinyao; Yao, Shuqiao

    2016-01-01

    Abnormalities in neural feedback-processing systems may play a role in the development of dysfunctional behavior in individuals diagnosed with conduct disorder (CD). The present study investigated the relation between CD adolescents and feedback processing by measuring event-related potentials (ERPs) in a single outcome gambling task, which included reward valence (loss and gain) and reward magnitude (10 and 50cents) as outcomes. N2 and P3 components have been established as effective indicators in studies of behavioral disinhibition, reward processing, and decision-making. Eighteen adolescent males (age: 13-17years) diagnosed with CD and 19 healthy age-matched male controls were recruited. Compared to healthy controls, CD individuals exhibited reduced N2 amplitudes in response to loss condition. There was also a significant decreased P3 amplitude in all conditions. The amplitudes of P3 were negatively correlated with impulsivity scores across both groups, and the amplitudes of N2 were positively correlated with impulsivity scores across both groups. Our findings suggest that adolescents with CD may be impaired in neural sensitivity feedback and the processing of environmental cues compared to healthy controls. Moreover, N2 and P3 may be reliable indices to detect different sensitivity in reward and punishment feedback processing. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Increased electrical conductivity of peptides through annealing process

    Directory of Open Access Journals (Sweden)

    Seok Daniel Namgung

    2017-08-01

    Full Text Available Biocompatible biologically occurring polymer is suggested as a component of human implantable devices since conventional inorganic materials are apt to trigger inflammation and toxicity problem within human body. Peptides consisting of aromatic amino acid, tyrosine, are chosen, and enhancement on electrical conductivity is studied. Annealing process gives rise to the decrease on resistivity of the peptide films and the growth of the carrier concentration is a plausible reason for such a decrease on resistivity. The annealed peptides are further applied to an active layer of field effect transistor, in which low on/off current ratio (∼10 is obtained.

  5. Dynamical interaction of He atoms with metal surfaces: Charge transfer processes

    International Nuclear Information System (INIS)

    Flores, F.; Garcia Vidal, F.J.; Monreal, R.

    1993-01-01

    A self-consistent Kohn-Sham LCAO method is presented to calculate the charge transfer processes between a He * -atom and metal surfaces. Intra-atomic correlation effects are taken into account by considering independently each single He-orbital and by combining the different charge transfer processes into a set of dynamical rate equations for the different ion charge fractions. Our discussion reproduces qualitatively the experimental evidence and gives strong support to the method presented here. (author). 24 refs, 4 figs

  6. Thermal signal propagation in soils in Romania: conductive and non-conductive processes

    Directory of Open Access Journals (Sweden)

    C. Demetrescu

    2007-11-01

    Full Text Available Temperature data recorded in 2002 and 2003 at 10 stations out of the 70 available in the Romanian automatic weather stations network are presented and analyzed in terms of the heat transfer from air to underground. The air temperature at 2 m, the soil temperatures at 0, 5, 10, 20, 50 and 100 cm below the surface as well as rain fall and snow cover thickness have been monitored. The selected locations sample various climate environments in Romania. Preliminary analytical modelling shows that soil temperatures track air temperature variations at certain locations and, consequently, the heat transfer is by conduction, while at other stations processes such as soil freezing and/or solar radiation heating play an important part in the heat flux balance at the air/soil interface. However, the propagation of the annual thermal signal in the uppermost one meter of soil is mainly by conduction; the inferred thermal diffusivity for 8 stations with continuous time series at all depth levels ranges from 3 to 10×10−7 m2 s−1.

  7. In-situ analysis of microwave conductivity and impedance spectroscopy for evaluation of charge carrier dynamics at interfaces

    Science.gov (United States)

    Choi, Wookjin; Inoue, Junichi; Tsutsui, Yusuke; Sakurai, Tsuneaki; Seki, Shu

    2017-11-01

    A unique concerted analysis comprising non-contact microwave conductivity measurements and impedance spectroscopy was developed to simultaneously assess the charge carrier mobility and injection barriers. The frequency dependence of the microwave conductivity as well as the electrical current was analyzed by applying sinusoidal voltage to determine the equivalent circuit parameters. Based on the temperature dependence of the circuit parameters, the energy of the injection barrier was estimated to be 0.4 eV with the Richardson-Schottky model, and the band-like transport was confirmed with the negative temperature coefficient with the β value of 1.4 in the intra-layer conduction of C8-BTBT. In contrast, the increase in the resistance of the C8-BTBT layer with decreasing temperature implied the occurrence of hopping-like transport in the inter-layer conduction of C8-BTBT.

  8. Electrical conductivity and charge carrier screening in weakly non-ideal argon plasmas

    International Nuclear Information System (INIS)

    Guenther, K.; Lang, S.; Radtke, R.

    1983-01-01

    A pulsed argon discharge as a stable source of weakly non-ideal plasmas is described in connection with the diagnostic necessities for conductivity measurements. The parameters overlap the range for stationary arcs and allow comparison with measurements in cascade arcs. The measured conductivities are explained using the binary collision model considering collisions with neutrals, excited atoms, and ions. A relation between the screening parameter and non-ideality is proposed which should be valid for all elements. (author)

  9. Electrical conductivity and charge carrier screening in weakly non-ideal argon plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, K; Lang, S; Radtke, R [Akademie der Wissenschaften der DDR, Jena. Zentralinstitut fuer Elektronenphysik

    1983-07-14

    A pulsed argon discharge as a stable source of weakly non-ideal plasmas is described in connection with the diagnostic necessities for conductivity measurements. The parameters overlap the range for stationary arcs and allow comparison with measurements in cascade arcs. The measured conductivities are explained using the binary collision model considering collisions with neutrals, excited atoms, and ions. A relation between the screening parameter and non-ideality is proposed which should be valid for all elements.

  10. Analysis of the medication reconciliation process conducted at hospital admission

    Directory of Open Access Journals (Sweden)

    María Beatriz Contreras Rey

    2016-07-01

    Full Text Available Objective: To analyze the outcomes of a medication reconciliation process at admission in the hospital setting. To assess the role of the Pharmacist in detecting reconciliation errors and preventing any adverse events entailed. Method: A retrospective study was conducted to analyze the medication reconciliation activity during the previous six months. The study included those patients for whom an apparently not justified discrepancy was detected at admission, after comparing the hospital medication prescribed with the home treatment stated in their clinical hospital records. Those patients for whom the physician ordered the introduction of home medication without any specification were also considered. In order to conduct the reconciliation process, the Pharmacist prepared the best pharmacotherapeutical history possible, reviewing all available information about the medication the patient could be taking before admission, and completing the process with a clinical interview. The discrepancies requiring clarification were reported to the physician. It was considered that the reconciliation proposal had been accepted if the relevant modification was made in the next visit of the physician, or within 24-48 hours maximum; this case was then labeled as a reconciliation error. For the descriptive analysis, the Statistics® SPSS program, version 17.0, was used. Outcomes: 494 medications were reconciled in 220 patients, with a mean of 2.25 medications per patient. More than half of patients (59.5% had some discrepancy that required clarification; the most frequent was the omission of a medication that the patient was taking before admission (86.2%, followed by an unjustified modification in dosing or way of administration (5.9%. In total, 312 discrepancies required clarification; out of these, 93 (29.8% were accepted and considered as reconciliation errors, 126 (40% were not accepted, and in 93 cases (29,8% acceptance was not relevant due to a change in

  11. Charge generation and trapping in bisphenol-A-polycarbonate/N-isopropylcarbazole mixture: A study by electron bombardment-induced conductivity

    International Nuclear Information System (INIS)

    Santos, S.; Caraballo, D.

    2007-01-01

    Electron bombardment-induced conductivity measurements were carried out on cast films of N-isopropylcarbazole (NIPC) dispersed into an amorphous matrix of bisphenol-A-polycarbonate. The charge generation was studied by estimating the hole yield (g), the fraction of charge escaping recombination, as a function of electric field and concentration of NIPC at room temperature. The hole yield, besides increasing by increasing the content of NIPC, was observed to increase with the electric field in the manner predicted by the Onsager theory of geminate recombination. Deep trapping levels were studied by filling under electron bombardment and observing transients. The deep traps were neutral in nature with a concentration on the order of 8.0x10 14 cm -3 , which was low enough not to degrade transport under normal conditions

  12. Energy gaps, valence and conduction charge densities and optical properties of GaAs1‑xPx

    Science.gov (United States)

    Al-Hagan, O. A.; Algarni, H.; Bouarissa, N.; Alhuwaymel, T. F.; Ajmal Khan, M.

    2018-04-01

    The electronic structure and its derived valence and conduction charge distributions along with the optical properties of zinc-blende GaAs1‑xPx ternary alloys have been studied. The calculations are performed using a pseudopotential approach under the virtual crystal approximation (VCA) which takes into account the compositional disorder effect. Our findings are found to be generally in good accord with experiment. The composition dependence of direct and indirect bandgaps showed a clear bandgap bowing. The nature of the gap is found to depend on phosphorous content. The bonding and ionicity of the material of interest have been examined in terms of the anti-symmetric gap and charge densities. The variation in the optical constants versus phosphorous concentration has been discussed. The present investigation may give a useful applications in infrared and visible spectrum light emitters.

  13. Attosecond Electron Processes in Materials: Excitons, Plasmons, and Charge Dynamics

    Science.gov (United States)

    2015-05-19

    focused using a f=1.5 m lens into a 250 micron hollow core fiber (HCF) filled with neon gas at atmospheric pressure to stretch the pulse spectrum from... insulator to metal transition. Introduction: The goal of this work was to understand the generation, transport, and manipulation of electronic charge...chemically sensitive probe pulse utilizing specific core level transitions in atoms that are part of a material under study. The measurements follow

  14. The space charge effects on the slow extraction process

    International Nuclear Information System (INIS)

    Ohmori, Chihiro.

    1992-06-01

    The calculation of the slow extraction which includes the space charge effects has been performed for the Compressor/Stretcher Ring (CSR) of the proposed Japanese Hadron Project. We have investigated the slow extraction of 1 GeV proton beam with an average current of 100μA. Calculation shows not only the emittance growth of the extracted beam but also decrease of the extraction efficiency and discontinuity of beam spill. (author)

  15. Stress Induced Charge-Ordering Process in LiMn_2O_4

    International Nuclear Information System (INIS)

    Chen, Yan; Yu, Dunji; An, Ke

    2016-01-01

    In this letter we report the stress-induced Mn charge-ordering process in the LiMn_2O_4 spinel, evidenced by the lattice strain evolutions due to the Jahn–Teller effects. In situ neutron diffraction reveals the initial stage of this process at low stress, indicating the eg electron localization at the preferential Mn sites during the early phase transition as an underlying charge-ordering mechanism in the charge-frustrated LiMn_2O_4. The initial stage of this transition exhibits as a progressive lattice and charge evolution, without showing a first-order behavior.

  16. 3D polyaniline porous layer anchored pillared graphene sheets: enhanced interface joined with high conductivity for better charge storage applications.

    Science.gov (United States)

    Sekar, Pandiaraj; Anothumakkool, Bihag; Kurungot, Sreekumar

    2015-04-15

    Here, we report synthesis of a 3-dimensional (3D) porous polyaniline (PANI) anchored on pillared graphene (G-PANI-PA) as an efficient charge storage material for supercapacitor applications. Benzoic acid (BA) anchored graphene, having spatially separated graphene layers (G-Bz-COOH), was used as a structure controlling support whereas 3D PANI growth has been achieved by a simple chemical oxidation of aniline in the presence of phytic acid (PA). The BA groups on G-Bz-COOH play a critical role in preventing the restacking of graphene to achieve a high surface area of 472 m(2)/g compared to reduced graphene oxide (RGO, 290 m(2)/g). The carboxylic acid (-COOH) group controls the rate of polymerization to achieve a compact polymer structure with micropores whereas the chelating nature of PA plays a crucial role to achieve the 3D growth pattern of PANI. This type of controlled interplay helps G-PANI-PA to achieve a high conductivity of 3.74 S/cm all the while maintaining a high surface area of 330 m(2)/g compared to PANI-PA (0.4 S/cm and 60 m(2)/g). G-PANI-PA thus conceives the characteristics required for facile charge mobility during fast charge-discharge cycles, which results in a high specific capacitance of 652 F/g for the composite. Owing to the high surface area along with high conductivity, G-PANI-PA displays a stable specific capacitance of 547 F/g even with a high mass loading of 3 mg/cm(2), an enhanced areal capacitance of 1.52 F/cm(2), and a volumetric capacitance of 122 F/cm(3). The reduced charge-transfer resistance (RCT) of 0.67 Ω displayed by G-PANI-PA compared to pure PANI (0.79 Ω) stands out as valid evidence of the improved charge mobility achieved by the system by growing the 3D PANI layer along the spatially separated layers of the graphene sheets. The low RCT helps the system to display capacitance retention as high as 65% even under a high current dragging condition of 10 A/g. High charge/discharge rates and good cycling stability are the other

  17. Charge modulated interfacial conductivity in SrTiO3-based oxide heterostructures

    DEFF Research Database (Denmark)

    Chen, Yunzhong; Stamate, Eugen; Pryds, Nini

    2011-01-01

    When depositing amorphous SrTiO3 (STO) films on crystalline STO substrates by pulsed laser deposition, metallic interfaces are observed, though both materials are band-gap insulators. The interfacial conductivity exhibits strong dependence on oxygen pressure during film growth, which is closely...

  18. The calculation of electron chemical potential and ion charge state and their influence on plasma conductivity in electrical explosion of metal wire

    International Nuclear Information System (INIS)

    Shi, Zongqian; Wang, Kun; Li, Yao; Shi, Yuanjie; Wu, Jian; Jia, Shenli

    2014-01-01

    The electron chemical potential and ion charge state (average ion charge and ion distribution) are important parameters in calculating plasma conductivity in electrical explosion of metal wire. In this paper, the calculating method of electron chemical potential and ion charge state is discussed at first. For the calculation of electron chemical potential, the ideal free electron gas model and Thomas-Fermi model are compared and analyzed in terms of the coupling constant of plasma. The Thomas-Fermi ionization model, which is used to calculate ion charge state, is compared with the method based on Saha equation. Furthermore, the influence of electron degenerated energy levels and ion excited states in Saha equation on the ion charge state is also analyzed. Then the influence of different calculating methods of electron chemical potential and ion charge state on plasma conductivity is discussed by applying them in the Lee-More conductivity model

  19. Droop-Control-Based State-of-Charge Balancing Method for Charging and Discharging Process in Autonomous DC Microgrids

    DEFF Research Database (Denmark)

    Lu, Xiaonan; Sun, Kai; Guerrero, Josep M.

    2014-01-01

    in the discharging process. Meanwhile, the ESU with lower SoC absorbs more power in the charging process and delivers less power in the discharging process. Eventually, the SoC and injected/output power in each ESU are equalized. The exponent n for SoC is employed to regulate the balancing speed of the So......C and injected/output power. It is demonstrated that with higher exponent n, the balancing speed is higher. Simulation model comprised of three ESUs is implemented by using MATLAB/Simulink. The proposed method is verified by the simulation results....

  20. Dual cell conductivity during ionic exchange processes: the intelligent transmitter EXA DC 400

    International Nuclear Information System (INIS)

    Mier, A.

    1997-01-01

    Why is differential conductivity important versus standard conductivity measurement? That entirely depends on the application. If we have a process where the conductivity changes ge.. Cation exchanger, then standard conductivity measurement is not appropriate. With dual cell conductivity we can rate the process and eliminate conductivity changes outside the process. Therefore we achieve more precise control or monitoring of that process. (Author)

  1. Ionic conductivity of polymer gels deriving from alkali metal ionic liquids and negatively charged polyelectrolytes

    International Nuclear Information System (INIS)

    Ogihara, Wataru; Sun Jiazeng; Forsyth, Maria; MacFarlane, Douglas R.; Yoshizawa, Masahiro; Ohno, Hiroyuki

    2004-01-01

    We have prepared polymer gel electrolytes with alkali metal ionic liquids (AMILs) that inherently contain alkali metal ions. The AMIL consisted of sulfate anion, imidazolium cation, and alkali metal cation. AMILs were mixed directly with poly(3-sulfopropyl acrylate) lithium salt or poly(2-acrylamido-2-methylpropanesulfonic acid) lithium salt to form polymer gels. The ionic conductivity of these gels decreased with increasing polymer fraction, as in general ionic liquid/polymer mixed systems. At low polymer concentrations, these gels displayed excellent ionic conductivity of 10 -4 to 10 -3 S cm -1 at room temperature. Gelation was found to cause little change in the 7 Li diffusion coefficient of the ionic liquid, as measured by pulse-field-gradient NMR. These data strongly suggest that the lithium cation migrates in successive pathways provided by the ionic liquids

  2. Conductivity relaxation and charge transport of trihexyl tetradecyl phosphonium dicyanamide ionic liquid by broadband dielectric spectroscopy

    Science.gov (United States)

    Thasneema K., K.; Thayyil, M. Shahin; Krishna Kumar N., S.; Govindaraj, G.; Saheer, V. C.

    2018-04-01

    Usually ionic liquids consists of a large organic cation with low symmetry such as imidazolium, pyridinium, quaternary ammonium or phosponium etc combined with enormously wide range of inorganic or organic symmetric anion with melting point below 100. Ionic liquids existing in an extremely large number of possible ion pair combinations. It offers a very wide range of thermo physical properties led to the concept of designer solvents for specific applications. Due to the features of high chemical and thermal stability, low vapor pressure non flammability high ionic conductivity, and they show a good solvent ability towards a great variety of organic or inorganic compounds, ionic liquids have a widespread use in many areas such as batteries, fuel cell, solar cells, super capacitors etc. The main focus of this work is the study of molecular dynamics and conductivity relaxation of amorphous Trihexyl tetradecyl phosphonium dicyanamide ([P14,6,6,6][N(CN)2]) ionic liquid which is proved as a better electrolyte in super capacitors, over a wide frequency 10-2 Hz to 107 Hz and the temperature range between 123k and 265 k by means of Broadband Dielectric Spectroscopy. We observe alpha conductivity relaxation and secondary relaxation above and below Glass Transition Temperature. The experimental results were analyzed using electric modulus representation. The analysis emphasis the inter molecular interaction and the nature of glass forming system, whether it is fragile or strong system. The ionic liquid shows a fragile behavior and the fragility index m=123.59. TGA result of the sample exhibit a good resistance to thermal decomposition, up to 300°C.

  3. Charge amplification and transfer processes in the gas electron multiplier

    International Nuclear Information System (INIS)

    Bachmann, S.; Bressan, A.; Ropelewski, L.; Sauli, F.; Sharma, A.; Moermann, D.

    1999-01-01

    We report the results of systematic investigations on the operating properties of detectors based on the gas electron multiplier (GEM). The dependence of gain and charge collection efficiency on the external fields has been studied in a range of values for the hole diameter and pitch. The collection efficiency of ionization electrons into the multiplier, after an initial increase, reaches a plateau extending to higher values of drift field the larger the GEM voltage and its optical transparency. The effective gain, fraction of electrons collected by an electrode following the multiplier, increases almost linearly with the collection field, until entering a steeper parallel plate multiplication regime. The maximum effective gain attainable increases with the reduction in the hole diameter, stabilizing to a constant value at a diameter approximately corresponding to the foil thickness. Charge transfer properties appear to depend only on ratios of fields outside and within the channels, with no interaction between the external fields. With proper design, GEM detectors can be optimized to satisfy a wide range of experimental requirements: tracking of minimum ionizing particles, good electron collection with small distortions in high magnetic fields, improved multi-track resolution and strong ion feedback suppression in large volume and time-projection chambers

  4. Process for first charge of gas cooled nuclear reactors with fuel elements

    International Nuclear Information System (INIS)

    Bromkamp, K.H.; Daoud, H.; Engelhardt, K.; Hantke, H.J.

    1979-01-01

    The charging of the THTR-300 takes place continuously via three positions in the inner zone and 12 positions in the outer zone. The inner and outer zone are charged alternately. The size of the charging step is chosen so that the mixing zone formed between the two zones does not exceed a given width. The reflector rods are driven out during the whole fuelling process and the core rods are driven into the core. The charging always takes place in the sub-critical condition, where the degree of sub-criticality is checked by measurement of the inverse multiplication factor after each fuelling step. (DG) [de

  5. OMICRON, LLNL ENDL Charged Particle Data Library Processing

    International Nuclear Information System (INIS)

    Mengoni, A.; Panini, G.C.

    2002-01-01

    1 - Description of program or function: The program has been designed to read the Evaluated Charged Particle Library (ECPL) of the LLNL Evaluated Nuclear Data Library (ENDL) and generate output in various forms: interpreted listing, ENDF format and graphs. 2 - Method of solution: A file containing ECPL in card image transmittal format is scanned to retrieve the requested reactions from the requested materials; in addition selections can be made by data type or incident particle. 3 - Restrictions on the complexity of the problem: The Reaction Property Designator I determines the type of data in the ENDL library (e.g. cross sections, angular distributions, Maxwellian averages, etc.); the program does not take into account the data for I=3,4 (energy-angle-distributions) since there are no data in the current ECPL version

  6. Integrating high electrical conductivity and photocatalytic activity in cotton fabric by cationizing for enriched coating of negatively charged graphene oxide.

    Science.gov (United States)

    Sahito, Iftikhar Ali; Sun, Kyung Chul; Arbab, Alvira Ayoub; Qadir, Muhammad Bilal; Jeong, Sung Hoon

    2015-10-05

    Electroconductive textiles have attended tremendous focus recently and researchers are making efforts to increase conductivity of e-textiles, in order to increase the use of such flexible and low cost textile materials. In this study, surface conductivity and photo catalytic activity of standard cotton fabric (SCF) was enhanced by modifying its surface charge, from negative to positive, using Bovine Serum Albumin (BSA) as a cationic agent, to convert it into cationised cotton fabric (CCF). Then, both types of fabrics were dip coated with a simple dip and dry technique for the adsorption of negatively charged graphene oxide (GO) sheets onto its surface. This resulted in 67.74% higher loading amount of GO on the CCF making self-assembly. Finally, this coating was chemically converted by vapor reduction using hydrazine hydrate to reduced graphene oxide (rGO) for restoration of a high electrical conductivity at the fabric surface. Our results revealed that with such high loading of GO, the surface resistance of CCF was only 40Ω/sq as compared to 510Ω/sq of the SCF and a 66% higher photo catalytic activity was also achieved through cationization for improved GO coating. Graphene coated SCF and CCF were characterized using FE-SEM, FTIR, Raman, UV-vis, WAXD, EDX and XPS spectroscopy to ascertain successful reduction of GO to rGO. The effect of BSA treatment on adsorption of cotton fabric was studied using drop shape analyzer to measure contact angle and for thermal and mechanical resistance, the fabric was tested for TGA and tensile strength, respectively. rGO coated fabric also showed slightly improved thermal stability yet a minor loss of strength was observed. The high flexibility, photocatalytic activity and excellent conductivity of this fabric suggests that it can be used as an electrode material for various applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Preparation of Highly Conductive Yarns by an Optimized Impregnation Process

    Science.gov (United States)

    Amba Sankar, K. N.; Mohanta, Kallol

    2018-03-01

    We report the development of the electrical conductivity in textile yarns through impregnation and post-treatment of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). The conductive polymer is deposited on fibers, which fills the gap space within the hierarchical structure of the yarns. Organic nonpolar solvents act as reducing agent to increase the density of PEDOT moieties on the yarns, galvanizing increment in conductivity values. Post-treatment by ethylene glycol transforms the resonance configuration of the conductive moieties of conjugated polymer, which helps in further enhancement of electrical conductivity of the yarns. We have optimized the method in terms of loading and conformal change of the polymer to have a lesser resistance of the coated conductive yarns. The minimum resistance achieved has a value of 77 Ωcm-1. This technique of developing conductivity in conventional yarns enables retaining the flexibility of yarns and feeling of softness which would find suitable␣applications for wearable electronics.

  8. Charge transport through conducting organic poly(2-methoxy-5- (2-ethylhexyloxy)-1, 4-phenylenevinylene)

    International Nuclear Information System (INIS)

    Kumar, Pankaj; Misra, Aparna; Kamalasanan, M N; Jain, S C; Kumar, Vikram

    2007-01-01

    Current-voltage (J-V) characteristics of poly(2-methoxy-5- (2-ethyhexyloxy)-1, 4-phenylenevinylene)(MEH-PPV) have been studied in the hole-only devices ITO/PEDOT : PSS/MEH-PPV/Au, as a function of temperature from 300 to 98 K. Hole conduction in MEH-PPV has been well explained by an exponential trap-controlled drift model. In a considerable range of applied voltages, current obeys the power law J ∼ V l+1 , where l = T c /T and T c is the characteristic temperature of the exponential trap distribution. Assuming the effective density of states N ν = 2.7 x 10 18 cm -3 , the holes trap density (H b ) and characteristic temperature (T c ) have been calculated to be 1 x 10 18 cm -3 and 550 K, respectively. As the voltage further increases current deviates and becomes smaller than J ∼ V l+1 . At low temperatures and sufficiently high-applied voltages, current follows the V 2 law. At higher temperatures slopes less than 2 of the log J-log V plots have been observed. The possible reasons for this behaviour are mentioned

  9. Describing long-range charge-separation processes with subsystem density-functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Solovyeva, Alisa; Neugebauer, Johannes, E-mail: j.neugebauer@uni-muenster.de [Theoretische Organische Chemie, Organisch-Chemisches Institut and Center for Multiscale Theory and Simulation, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster (Germany); Pavanello, Michele, E-mail: m.pavanello@rutgers.edu [Department of Chemistry, Rutgers University, 73 Warren St., Newark, New Jersey 07102 (United States)

    2014-04-28

    Long-range charge-transfer processes in extended systems are difficult to describe with quantum chemical methods. In particular, cost-effective (non-hybrid) approximations within time-dependent density functional theory (DFT) are not applicable unless special precautions are taken. Here, we show that the efficient subsystem DFT can be employed as a constrained DFT variant to describe the energetics of long-range charge-separation processes. A formal analysis of the energy components in subsystem DFT for such excitation energies is presented, which demonstrates that both the distance dependence and the long-range limit are correctly described. In addition, electronic couplings for these processes as needed for rate constants in Marcus theory can be obtained from this method. It is shown that the electronic structure of charge-separated states constructed by a positively charged subsystem interacting with a negatively charged one is difficult to converge — charge leaking from the negative subsystem to the positive one can occur. This problem is related to the delocalization error in DFT and can be overcome with asymptotically correct exchange–correlation (XC) potentials or XC potentials including a sufficiently large amount of exact exchange. We also outline an approximate way to obtain charge-transfer couplings between locally excited and charge-separated states.

  10. Describing long-range charge-separation processes with subsystem density-functional theory

    International Nuclear Information System (INIS)

    Solovyeva, Alisa; Neugebauer, Johannes; Pavanello, Michele

    2014-01-01

    Long-range charge-transfer processes in extended systems are difficult to describe with quantum chemical methods. In particular, cost-effective (non-hybrid) approximations within time-dependent density functional theory (DFT) are not applicable unless special precautions are taken. Here, we show that the efficient subsystem DFT can be employed as a constrained DFT variant to describe the energetics of long-range charge-separation processes. A formal analysis of the energy components in subsystem DFT for such excitation energies is presented, which demonstrates that both the distance dependence and the long-range limit are correctly described. In addition, electronic couplings for these processes as needed for rate constants in Marcus theory can be obtained from this method. It is shown that the electronic structure of charge-separated states constructed by a positively charged subsystem interacting with a negatively charged one is difficult to converge — charge leaking from the negative subsystem to the positive one can occur. This problem is related to the delocalization error in DFT and can be overcome with asymptotically correct exchange–correlation (XC) potentials or XC potentials including a sufficiently large amount of exact exchange. We also outline an approximate way to obtain charge-transfer couplings between locally excited and charge-separated states

  11. Charge-exchange processes in a divertor plasma with account for excited particles

    International Nuclear Information System (INIS)

    Krasheninnikov, S.I.; Lisitsa, V.S.; Pigarov, A.Yu.

    1988-01-01

    A model describing dynamics of neutral atoms and multicharge ions in tokamak plasma, taking account of cascade excitation effect on charge exchange and ionization processes, is constructed. Dependences of effective rate of processes of proton charge exchange on hydrogen atom and non-resonance helium atom charge exchange on proton and α-particle- on atomic hydrogen on tokamak divertor plasma parameters are calculated. It is shown that H + +He→H-He + charge exchange can make up a notable shave (∼30%) in full helium ionization rate. Accounting for Ge 2+ charge exchange on atomic hydrogen under INTOR reactor divertor plasma conditions can lead to substantial He 2+ →He + conversion and thus increase diverter plate sputtering by helium ions

  12. A stochastic model of multiple scattering of charged particles: process, transport equation and solutions

    International Nuclear Information System (INIS)

    Papiez, L.; Moskvin, V.; Tulovsky, V.

    2001-01-01

    The process of angular-spatial evolution of multiple scattering of charged particles can be described by a special case of Boltzmann integro-differential equation called Lewis equation. The underlying stochastic process for this evolution is the compound Poisson process on the surface of the unit sphere. The significant portion of events that constitute compound Poisson process that describes multiple scattering have diffusional character. This property allows to analyze the process of angular-spatial evolution of multiple scattering of charged particles as combination of soft and hard collision processes and compute appropriately its transition densities. These computations provide a method of the approximate solution to the Lewis equation. (orig.)

  13. Framework for Conducting Empirical Observations of Learning Processes.

    Science.gov (United States)

    Fischer, Hans Ernst; von Aufschnaiter, Stephan

    1993-01-01

    Reviews four hypotheses about learning: Comenius's transmission-reception theory, information processing theory, Gestalt theory, and Piagetian theory. Uses the categories preunderstanding, conceptual change, and learning processes to classify and assess investigations on learning processes. (PR)

  14. Insights into collaborative separation process of photogenerated charges and superior performance of solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiangyang, E-mail: lxy081276@126.com; Wang, Shun; Zheng, Haiwu; Gu, Yuzong [Institute of Microsystems Physics and School of Physics and Electronics, Henan University, Kaifeng 475004 (China)

    2016-07-25

    ZnO nanowires/Cu{sub 4}Bi{sub 4}S{sub 9} (ZnO/CBS) and ZnO nanowires/CBS-graphene nanoplates (ZnO/CBS-GNs), as well as two types of solar cells were prepared. The photovoltaic responses of CBS-GNs and ZnO/CBS-GNs can be improved with incorporation of GNs. The transient surface photovoltage (TPV) can provide detailed information on the separation and transport of photogenerated carriers. The multichannel separation process from the TPVs indicates that the macro-photoelectric signals can be attributed to the photogenerated charges separated at the interface of CBS/GNs, rather than CBS/ZnO. The multi-interfacial recombination is the major carrier loss, and the hole selective p-V{sub 2}O{sub 5} can efficiently accelerate the charge extraction to the external circuit. The ZnO/CBS-GNs cell exhibits the superior performance, and the highest efficiency is 10.9%. With the adequate interfaces of CBS/GNs, GNs conductive network, energy level matching, etc., the excitons can easily diffuse to the interface of CBS/GNs, and the separated electrons and holes can be collected quickly, inducing the high photoelectric properties. Here, a facile strategy for solid state solar cells with superior performance presents a potential application.

  15. Charge exchange processes of high energy heavy ions channeled in crystals

    International Nuclear Information System (INIS)

    Andriamonje, S.; Dural, J.; Toulemonde, M.; Groeneveld, K.O.; Maier, R.; Quere, Y.

    1990-01-01

    The interaction of moving ions with single crystals is very sensitive to the orientation of the incident beam with respect to the crystalline directions of the target. The experiments show that high energy heavy ion channeling deeply modifies the slowing down and charge exchange processes. In this review, we describe the opportunity offered by channeling conditions to study the charge exchange processes. Some aspects of the charge exchange processes with high energy channeled heavy ions are selected from the extensive literature published over the past few years on this subject. Special attention is given to the work performed at the GANIL facility on the study of Radiative Electron Capture (REG), Electron Impact Ionisation (EII), and convoy electron emission. Finally we emphasize the interest of studying resonant charge exchange processes such as Resonant Coherent Excitation (RCE), Resonant Transfer and Excitation (RTE) or Dielectronic Recombination (DR) and the recently proposed Nuclear Excitation by Electron Capture (NEEC)

  16. Electron transfer and decay processes of highly charged iodine ions

    International Nuclear Information System (INIS)

    Sakaue, Hiroyuki A.; Danjo, Atsunori; Hosaka, Kazumoto

    2005-01-01

    In the present experimental work we have investigated multi-electron transfer processes in I q+ (q=10, 15, 20 and 25) + Ne, Ar, Kr and Xe collisions at 1.5q keV energy. The branching ratios between Auger and radiative decay channels have been measured in decay processes of multiply excited states formed by multi-electron transfer collisions. It has been shown that, in all the multi-electron transfer processes investigated, the Auger decays are far dominant over the radiative decay processes and the branching ratios are clearly characterized by the average principal quantum number of the initial excited states of projectile ions. We could express the branching ratios in high Rydberg states formed in multi-electron transfer processes by using the decay probability of one Auger electron emission. (author)

  17. Overview on collision processes of highly charged ions with atoms present status and problems

    International Nuclear Information System (INIS)

    Janev, R.K.

    1983-05-01

    This paper provides a brief discussion on the present status of the collision physics of highly charged ions with atoms. The emphasis is on the main achievements in understanding and describing the most important collision processes, and as charge transfer, ionization and Auger-type processes, and even more on those open problems which, due either to their scientific or practical importance, represent challenges to current research in this field. The paper concentrates on general ideas and problems whose development and solutions have advanced or will advance our basic understanding of the collision dynamics of multiply charged ions with atoms

  18. Study of conduction mechanisms and relaxation processes in NiCl2-PVA composites

    International Nuclear Information System (INIS)

    Basha, A.F.; Amin, M.; Abdel Samad, H.A.

    1985-07-01

    Electric conduction measurements were made at different temperatures and fields on thin films NiCl 2 -PVA composites prepared by casting. The conduction is assumed to be generally ionic in nature and polarization contribution is suggested to operate mainly at higher temperatures. Space-charge limited conduction and relaxation phenomena have been observed. The obtained results made it possible to determine a complete set of conduction parameters including carrier mobility, carrier concentration, traps density, Fermi energy, activation energy, etc. (author)

  19. Charge Splitting In Situ Recorder (CSIR) for Real-Time Examination of Plasma Charging Effect in FinFET BEOL Processes

    Science.gov (United States)

    Tsai, Yi-Pei; Hsieh, Ting-Huan; Lin, Chrong Jung; King, Ya-Chin

    2017-09-01

    A novel device for monitoring plasma-induced damage in the back-end-of-line (BEOL) process with charge splitting capability is first-time proposed and demonstrated. This novel charge splitting in situ recorder (CSIR) can independently trace the amount and polarity of plasma charging effects during the manufacturing process of advanced fin field-effect transistor (FinFET) circuits. Not only does it reveal the real-time and in situ plasma charging levels on the antennas, but it also separates positive and negative charging effect and provides two independent readings. As CMOS technologies push for finer metal lines in the future, the new charge separation scheme provides a powerful tool for BEOL process optimization and further device reliability improvements.

  20. Making DATA Work: A Process for Conducting Action Research

    Science.gov (United States)

    Young, Anita; Kaffenberger, Carol

    2013-01-01

    This conceptual model introduces a process to help school counselors use data to drive decision making and offers examples to implement the process. A step-by-step process is offered to help school counselors and school counselor supervisors address educational issues, close achievement gaps, and demonstrate program effectiveness. To illustrate…

  1. Conductivity of natural and modified DNA measured by scanning tunneling microscopy. The effect of sequence, charge and stacking

    Czech Academy of Sciences Publication Activity Database

    Kratochvílová, Irena; Král, Karel; Bunček, M.; Víšková, A.; Nešpůrek, Stanislav; Kochalska, Anna; Todorciuc, Tatiana; Weiter, M.; Schneider, Bohdan

    2008-01-01

    Roč. 138, č. 1-2 (2008), s. 3-10 ISSN 0301-4622 R&D Projects: GA ČR GA203/08/1594; GA AV ČR KAN401770651; GA MŠk OC 137; GA AV ČR KAN200100801; GA ČR GA202/07/0643 Grant - others:Marie-Curie RTN BIMORE(XE) MRTN-CT-2006-035859 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z40500505; CEZ:AV0Z50520701 Keywords : DNA conductivity * charge transport in molecular systems * STM * electronic properties Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.362, year: 2008

  2. Optical conductivity and optical effective mass in a high-mobility organic semiconductor: Implications for the nature of charge transport

    KAUST Repository

    Li, Yuan

    2014-12-03

    We present a multiscale modeling of the infrared optical properties of the rubrene crystal. The results are in very good agreement with the experimental data that point to nonmonotonic features in the optical conductivity spectrum and small optical effective masses. We find that, in the static-disorder approximation, the nonlocal electron-phonon interactions stemming from low-frequency lattice vibrations can decrease the optical effective masses and lead to lighter quasiparticles. On the other hand, the charge-transport and infrared optical properties of the rubrene crystal at room temperature are demonstrated to be governed by localized carriers driven by inherent thermal disorders. Our findings underline that the presence of apparently light carriers in high-mobility organic semiconductors does not necessarily imply bandlike transport.

  3. Optical conductivity and optical effective mass in a high-mobility organic semiconductor: Implications for the nature of charge transport

    KAUST Repository

    Li, Yuan; Yi, Yuanping; Coropceanu, Veaceslav; Bredas, Jean-Luc

    2014-01-01

    We present a multiscale modeling of the infrared optical properties of the rubrene crystal. The results are in very good agreement with the experimental data that point to nonmonotonic features in the optical conductivity spectrum and small optical effective masses. We find that, in the static-disorder approximation, the nonlocal electron-phonon interactions stemming from low-frequency lattice vibrations can decrease the optical effective masses and lead to lighter quasiparticles. On the other hand, the charge-transport and infrared optical properties of the rubrene crystal at room temperature are demonstrated to be governed by localized carriers driven by inherent thermal disorders. Our findings underline that the presence of apparently light carriers in high-mobility organic semiconductors does not necessarily imply bandlike transport.

  4. Theoretical study of charge exchange, ionization and electron loss processes, relevant to controlled thermonuclear research

    International Nuclear Information System (INIS)

    Janev, R.

    1981-03-01

    The following processes have been studied: a) Single and double charge exchange in low, medium and high energy collisions of atoms with multiply charged ions; b) Excitation and ionization processes in low, medium and high energy collisions between multiply charged ions and atoms; c) Ion-ion recombination and ion-pair formation collision processes between hydrogen and alkali atoms (ions); d) Resonant and Auger processes in slow collisions of atomic particles with solid surfaces (including surfaces covered by a sub-monoatomic layer). Processes a) and b) are important for the ''impurity problem'' of magnetically confined tokamak plasmas, whereas processes c) and d) for the production and transport of intense neutral beams for plasma heating

  5. On the height variation of the E-region cowling conductivity – effect of charged dust particles

    Directory of Open Access Journals (Sweden)

    P. Muralikrishna

    2006-11-01

    Full Text Available Height profiles of the Cowling conductivity in the electrojet region, estimated using the atmospheric parameters given by the existing models like CIRA or MSIS and measured electron density profiles, consistently show the heights of the electrojet current intensity peak to be more than 3 km below those estimated from in-situ measurements using magnetometers on board sounding rockets. Kulkarni and Muralikrishna (2005 attempted to explain this to be due to the effect of neutral dust particles. They reported that neutral dust particles, when they exist in sufficient numbers, can modify the collision parameters, especially in the lower E-region, where dust particles of meteoric origin are known to exist in large numbers, and thereby can modify the Cowling conductivity profile in the electrojet region. This work is extended here to include the effect of charged dust particles. Dust particles can become charged negatively by the attachment of ambient free electrons, and can thus reduce the number density of free electrons especially below the electrojet peak. This can alter the vertical profile of the east-west Hall current driven by the vertical Hall polarization field, thereby causing a net reduction in the electrojet current. Such a decrease in the electrojet current may be observed on the ground magnetograms. This mechanism, as proposed here, can operate only during periods of strong meteor shower activity, when the dust particle density at the assumed deposit height of 103 km can reach extreme values (for example, 5×104 cm−3 of 1-µm diameter dust particles. Such a dense dust layer may even cause a reversal in the normally upward vertical Hall polarization field, within the dust layer, causing a reversal of the electrojet currents below the current peak.

  6. Contribution of charge-transfer processes to ion-induced electron emission

    International Nuclear Information System (INIS)

    Roesler, M.; Garcia de Abajo, F.J.

    1996-01-01

    Charge changing events of ions moving inside metals are shown to contribute significantly to electron emission in the intermediate velocity regime via electrons coming from projectile ionization. Inclusion of equilibrium charge state fractions, together with two-electron Auger processes and resonant-coherent electron loss from the projectile, results in reasonable agreement with previous calculations for frozen protons, though a significant part of the emission is now interpreted in terms of charge exchange. The quantal character of the surface barrier transmission is shown to play an important role. The theory compares well with experimental observations for H projectiles. copyright 1996 The American Physical Society

  7. Nanoparticle electrostatic loss within corona needle charger during particle-charging process

    International Nuclear Information System (INIS)

    Huang Chenghsiung; Alonso, Manuel

    2011-01-01

    A numerical investigation has been carried out to examine the electrostatic loss of nanoparticles in a corona needle charger. Two-dimensional flow field, electric field, particle charge, and particle trajectory were simulated to obtain the electrostatic deposition loss at different conditions. Simulation of particle trajectories shows that the number of charges per particle during the charging process depends on the particle diameter, radial position from the symmetry axis, applied voltage, Reynolds number, and axial distance along the charger. The numerical results of nanoparticle electrostatic loss agreed fairly well with available experimental data. The results reveal that the electrostatic loss of nanoparticles increases with increasing applied voltage and electrical mobility of particles; and with decreasing particle diameter and Reynolds number. A regression equation closely fitted the obtained numerical results for different conditions. The equation is useful for directly calculating the electrostatic loss of nanoparticles in the corona needle charger during particle-charging process.

  8. Measurements of charging-up processes in THGEM-based particle detectors

    Science.gov (United States)

    Pitt, M.; Correia, P. M. M.; Bressler, S.; Coimbra, A. E. C.; Shaked Renous, D.; Azevedo, C. D. R.; Veloso, J. F. C. A.; Breskin, A.

    2018-03-01

    The time-dependent gain variation of detectors incorporating Thick Gas Electron Multipliers (THGEM) electrodes was studied in the context of charging-up processes of the electrode's insulating surfaces. An experimental study was performed to examine model-simulation results of the aforementioned phenomena, under various experimental conditions. The results indicate that in a stable detector's environment, the gain stabilization process is mainly affected by the charging-up of the detector's insulating surfaces caused by the avalanche charges. The charging-up is a transient effect, occurring during the detector's initial operation period; it does not affect its long-term operation. The experimental results are consistent with the outcome of model-simulations.

  9. Charge exchange collisions in gases in the presence of competing processes

    International Nuclear Information System (INIS)

    Senba, Masayoshi; British Columbia Univ., Vancouver

    1988-01-01

    The slowing down of charged particles in noble gases has been investigated theoretically from the charge exchange regime down to thermal energy. A formalism has been developed which allows one to calculate the rate of energy loss, the collision rate, the slowing down time, the neutral fraction and other quantities of interest directly from the cross sections of the atomic process involved. The formalism has been applied to the case of muons in He where two experimental observables, the fraction of the neutral species (muonium) and the muon spin depolarisation during charge exchange, have been calculated. The calculations have reproduced experimental results very well. It has also been found that the elastic process at the end of the slowing down reduces the number of charge exchange collisions drastically, thus sensitively affecting the neutral fraction and the muon spin depolarisation. (author)

  10. Angular-Dependent EDMR Linewidth for Spin-Dependent Space-Charge-Limited Conduction in a Polycrystalline Pentacene

    Directory of Open Access Journals (Sweden)

    Kunito Fukuda

    2017-08-01

    Full Text Available Spin-dependent space-charge-limited carrier conduction in a Schottky barrier diode using polycrystalline p-type π-conjugated molecular pentacene is explored using multiple-frequency electrically detected magnetic resonance (EDMR spectroscopy with a variable-angle configuration. The measured EDMR spectra are decomposed into two components derived, respectively, from mobile and trapped positive polarons. The linewidth of the EDMR signal for the trapped polarons increases with increasing resonance magnetic field for an in-plane configuration where the normal vector of the device substrate is perpendicular to the resonance magnetic field, while it is independent of the field for an out-of-plane configuration. This difference is consistent with the pentacene arrangement on the device substrate, where pentacene molecules exhibit a uniaxial orientation on the out-of-substrate plane. By contrast, the mobile polarons do not show anisotropic behavior with respect to the resonance magnetic field, indicating that the anisotropic effect is averaged out owing to carrier motion. These results suggest that the orientational arrangements of polycrystalline pentacene molecules in a nano thin film play a crucial role in spin-dependent electrical conduction.

  11. Angular-dependent EDMR linewidth for spin-dependent space charge limited conduction in a polycrystalline pentacene

    Science.gov (United States)

    Fukuda, Kunito; Asakawa, Naoki

    2017-08-01

    Spin-dependent space charge limited carrier conduction in a Schottky barrier diode using polycrystalline p-type π-conjugated molecular pentacene is explored using multiple-frequency electrically detected magnetic resonance (EDMR) spectroscopy with a variable-angle configuration. The measured EDMR spectra are decomposed into two components derived respectively from mobile and trapped positive polarons. The linewidth of the EDMR signal for the trapped polarons increases with increasing resonance magnetic field for an in-plane configuration where the normal vector of the device substrate is perpendicular to the resonance magnetic field, while it is independent of the field for an out-of-plane configuration. This difference is consistent with the pentacene arrangement on the device substrate, where pentacene molecules exhibit a uniaxial orientation on the out-of-substrate plane. By contrast, the mobile polarons do not show anisotropic behavior with respect to the resonance magnetic field, indicating that the anisotropic effect is averaged out owing to carrier motion. These results suggest that the orientational arrangements of polycrystalline pentacene molecules in a nano thin film play a crucial role in spin-dependent electrical conduction.

  12. Far infrared conductivity of charge density wave materials and the oxygen isotope effect in high-Tc superconductors

    International Nuclear Information System (INIS)

    Creager, W.N.

    1991-09-01

    The far infrared reflectance and conductivity of (Ta 1-x Nb x Se 4 ) 2 I and TaS 3 have been measured to determine the origin of a huge infrared resonance that dominates the charge density wave (CDW) dynamics along with the pinned acoustic phason mode in the related materials (TaSe 4 ) 2 I and K 0. 3 MoO 3 . The measurements cover frequencies from 3 to 700cm -1 and the temperature range from 15K to 300K. In the niobium-doped alloys (Ta 1-x Nb x Se 4 ) 2 I, the size and frequency of the giant infrared mode remain nearly constant as the impurity concentration x is increased. For TaS 3 , the pinned acoustic phason near 0.5cm -1 dominates var-epsilon(ω) and an additional small mode lies near 9cm -1 . The latter mode is much smaller than the infrared mode in other CDW materials. These results rule out several models of a ''generic infrared mode'' in CDW excitations. They are compared in detail to the predictions of a recent theory attributing the infrared mode to a bound collective mode localized at impurity sites within the crystal. The transmittance of K 0.3 MoO 3 has been measured at 1.2K with a strong dc electric field applied across the crystal. Under these conditions, the charge density wave depins abruptly and carries large currents with near-zero differential resistance. For some samples, the low-frequency transmittance is enhanced slightly when the CDW depins. The magnitude of the oxygen isotope effect in the high-T c superconductor YBa 2 Cu 3 O 7 has been determined by substitution of 18 O for 16 O. A series of cross-exchanges was performed on high-quality polycrystalline specimens to eliminate uncertainties due to sample heat treatments and sample inhomogeneities

  13. Strange quark distribution and parton charge symmetry violation in a semi-inclusive process

    International Nuclear Information System (INIS)

    Kitagawa, Hisashi; Sakemi, Yasuhiro

    2000-01-01

    It is possible to observe a semi-inclusive reaction with tagged charged kaons using the RICH detector at DESY-HERA. Using the semi-inclusive process we study two kinds of parton properties in the nucleon. We study relations between cross sections and strange quark distributions, which are expected to be measured more precisely in such a process than in the process in which pions are tagged. We also investigate charge symmetry violation (CSV) in the nucleon, which appears in the region x ≤ 0.1. (author)

  14. Vibrational Spectra of β″-Type BEDT-TTF Salts: Relationship between Conducting Property, Time-Averaged Site Charge and Inter-Molecular Distance

    Directory of Open Access Journals (Sweden)

    Takashi Yamamoto

    2012-07-01

    Full Text Available The relationship between the conducting behavior and the degree of charge fluctuation in the β″-type BEDT-TTF salts is reviewed from the standpoints of vibrational spectroscopy and crystal structure. A group of β″-type ET salts demonstrates the best model compounds for achieving the above relationship because the two-dimensional structure is simple and great diversity in conducting behavior is realized under ambient pressure. After describing the requirement for the model compound, the methodology for analyzing the results of the vibrational spectra is presented. Vibrational spectroscopy provides the time-averaged molecular charge, the charge distribution in the two-dimensional layer, and the inter-molecular interactions, etc. The experimental results applied to 2/3-filled and 3/4-filled β″-type ET salts are reported. These experimental results suggest that the conducting property, the difference in the time-averaged molecular charges between the ionic and neutral-like sites, the alternation in the inter-molecular distances and the energy levels in the charge distributions are relevant to one another. The difference in the time-averaged molecular charges, ∆ρ, is a useful criterion for indicating conducting behavior. All superconductors presented in this review are characterized as small but finite ∆ρ.

  15. Numerical analysis of the influence of particle charging on the fume formation process in arc welding

    International Nuclear Information System (INIS)

    Tashiro, Shinichi; Matsui, Sho; Tanaka, Manabu; Murphy, Anthony B

    2013-01-01

    In order to clarify the influence of electrostatic forces caused by charging of particles on the coagulation process in fume formation in arc welding, a previously developed fume formation model is modified to consider the influence of charging, for both local thermodynamic equilibrium (LTE) and non-LTE conditions. The model takes into account formation of the particles from metal vapour by nucleation, growth of the particles by condensation of metal vapour and coagulation of the particles by collisions to form secondary particles. Results are obtained for both ballistic and Brownian motion of the particles. It is found that the growth of secondary particles is suppressed when the average particle charge becomes significant, because charging of the particle hinders collisions among secondary particles through the strong repulsive electrostatic force. Furthermore, deviations from LTE strongly affect the coagulation process, because the increased electron density at a given gas temperature increases the charging of particles. Brownian motion leads to larger secondary particles, since the average particle speed is increased. The influence of Brownian motion and particle charging cancel each other to a large extent, particularly when deviations from LTE are considered. (paper)

  16. Facile synthesis of bismuth oxyhalide nanosheet films with distinct conduction type and photo-induced charge carrier behavior

    Science.gov (United States)

    Jia, Huimin; He, Weiwei; Zhang, Beibei; Yao, Lei; Yang, Xiaokai; Zheng, Zhi

    2018-05-01

    A modified successive ionic layer adsorption and reaction (SILAR) method was developed to fabricate 2D ordered BiOX (X = CI, Br, I) nanosheet array films on FTO substrates at room temperature. The formation of BiOX films were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), UV-vis absorption spectroscopy, and X-ray photoelectron spectroscopy (XPS). The semiconductor surface states determine the type of semiconductor. Although BiOCI, BiOBr and BiOI belong to the bismuth oxyhalide semiconductor family and possess similar crystal and electronic structures, they show different conductivity types due to their respective surface states. Mott-Schottky curve results demonstrate that the BiOCl and BiOI nanosheet arrays display n-type semiconductor properties, while the BiOBr films exhibit p-type semiconductor properties. Assisted by surface photovoltage (SPV) and transient photovoltage (TPV) techniques, the photoinduced charge transfer dynamics on the surface/interface of the BiOX/FTO nanosheet films were systematically and comparatively investigated. As revealed by the results, both the separation and transfer dynamics of the photo-induced carrier are influenced by film thickness.

  17. Depolarization current relaxation process of insulating dielectrics after corona poling under different charging conditions

    Directory of Open Access Journals (Sweden)

    J. W. Zhang

    2017-10-01

    Full Text Available As an insulating dielectric, polyimide is favorable for the application of optoelectronics, electrical insulation system in electric power industry, insulating, and packaging materials in space aircraft, due to its excellent thermal, mechanical and electrical insulating stability. The charge storage profile of such insulating dielectric is utmost important to its application, when it is exposed to electron irradiation, high voltage corona discharge or other treatments. These treatments could induce changes in physical and chemical properties of treated samples. To investigate the charge storage mechanism of the insulating dielectrics after high-voltage corona discharge, the relaxation processes responsible for corona charged polyimide films under different poling conditions were analyzed by the Thermally Stimulated Discharge Currents method (TSDC. In the results of thermal relaxation process, the appearance of various peaks in TSDC spectra provided a deep insight into the molecular status in the dielectric material and reflected stored space charge relaxation process in the insulating polymers after corona discharge treatments. Furthermore, the different space charge distribution status under various poling temperature and different discharge voltage level were also investigated, which could partly reflect the influence of the ambiance condition on the functional dielectrics after corona poling.

  18. Depolarization current relaxation process of insulating dielectrics after corona poling under different charging conditions

    Science.gov (United States)

    Zhang, J. W.; Zhou, T. C.; Wang, J. X.; Yang, X. F.; Zhu, F.; Tian, L. M.; Liu, R. T.

    2017-10-01

    As an insulating dielectric, polyimide is favorable for the application of optoelectronics, electrical insulation system in electric power industry, insulating, and packaging materials in space aircraft, due to its excellent thermal, mechanical and electrical insulating stability. The charge storage profile of such insulating dielectric is utmost important to its application, when it is exposed to electron irradiation, high voltage corona discharge or other treatments. These treatments could induce changes in physical and chemical properties of treated samples. To investigate the charge storage mechanism of the insulating dielectrics after high-voltage corona discharge, the relaxation processes responsible for corona charged polyimide films under different poling conditions were analyzed by the Thermally Stimulated Discharge Currents method (TSDC). In the results of thermal relaxation process, the appearance of various peaks in TSDC spectra provided a deep insight into the molecular status in the dielectric material and reflected stored space charge relaxation process in the insulating polymers after corona discharge treatments. Furthermore, the different space charge distribution status under various poling temperature and different discharge voltage level were also investigated, which could partly reflect the influence of the ambiance condition on the functional dielectrics after corona poling.

  19. Approximation to the Modelling of Charge and Discharge Processes in Electrochemical Batteries by Integral Equations

    International Nuclear Information System (INIS)

    Balenzategui, J. L.

    1999-01-01

    A new way for the modelling of the charge and discharge processes in electrochemical batteries based on the use of integral equations is presented. The proposed method models the charge curves by the so called fractional or cumulative integrals of a certain objective function f(t) that must be sought. The charge figures can be easily fitted by breaking down this objective function as the addition of two different Lorentz type functions: the first one is associated to the own charge process and the second one to the overcharge process. The method allows calculating the starting voltage for overcharge as the intersection between both functions. The curve fitting of this model to different experimental charge curves, by using the Marquart algorithm, has shown very accurate results. In the case of discharge curves, two possible methods for modelling purposes are suggested, well by using the same kind of integral equations, well by the simple subtraction of an objective function f(t) from a constant value V O D. Many other aspects for the study and analysis of this method in order to improve its results in further developments are also discussed. (Author) 10 refs

  20. Far infrared conductivity of charge density wave materials and the oxygen isotope effect in high-T sub c superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Creager, W.N.

    1991-09-01

    The far infrared reflectance and conductivity of (Ta{sub 1-x}Nb{sub x}Se{sub 4}){sub 2}I and TaS{sub 3} have been measured to determine the origin of a huge infrared resonance that dominates the charge density wave (CDW) dynamics along with the pinned acoustic phason mode in the related materials (TaSe{sub 4}){sub 2}I and K{sub 0. 3}MoO{sub 3}. The measurements cover frequencies from 3 to 700cm{sup {minus}1} and the temperature range from 15K to 300K. In the niobium-doped alloys (Ta{sub 1-x}Nb{sub x}Se{sub 4}){sub 2}I, the size and frequency of the giant infrared mode remain nearly constant as the impurity concentration x is increased. For TaS{sub 3}, the pinned acoustic phason near 0.5cm{sup {minus}1} dominates {var epsilon}({omega}) and an additional small mode lies near 9cm{sup {minus}1}. The latter mode is much smaller than the infrared mode in other CDW materials. These results rule out several models of a generic infrared mode'' in CDW excitations. They are compared in detail to the predictions of a recent theory attributing the infrared mode to a bound collective mode localized at impurity sites within the crystal. The transmittance of K{sub 0.3}MoO{sub 3} has been measured at 1.2K with a strong dc electric field applied across the crystal. Under these conditions, the charge density wave depins abruptly and carries large currents with near-zero differential resistance. For some samples, the low-frequency transmittance is enhanced slightly when the CDW depins. The magnitude of the oxygen isotope effect in the high-{Tc} superconductor YBa{sub 2}Cu{sub 3}O{sub 7} has been determined by substitution of {sup 18}O for {sup 16}O. A series of cross-exchanges was performed on high-quality polycrystalline specimens to eliminate uncertainties due to sample heat treatments and sample inhomogeneities.

  1. Charge dependence of one and two electron processes in collisions between hydrogen molecules and fast projectiles

    International Nuclear Information System (INIS)

    Wells, E.; Ben-Itzhak, I.; Carnes, K.D.; Krishnamurthi, V.

    1996-01-01

    The ratio of double- to single-ionization (DI/SI) as well as the ratio of ionization-excitation to single-ionization (IE/SI) in hydrogen molecules was studied by examining the effect of the projectile charge on these processes. The DI/SI and IE/SI ratios were measured using the coincidence time of flight technique at a fixed velocity (1 MeV/amu) over a range of projectile charge states (q = 1-9,14,20). Preliminary results indicate that for a highly charged F 9+ projectile the DI/SI and IE/SI ratios are 6.8% and 24.7%, respectively, a large increase from the ratios of 0.13% and 1.95%, respectively, for H + projectiles. For low charge states, the DI/SI is negligible relative to the IE/SI ratio, while for more highly charged projectiles the DI/SI ratio becomes comparable to the IE/SI ratio. This indicates that double-ionization increases much more rapidly with projectile charge than ionization-excitation

  2. Effect of plasma-induced surface charging on catalytic processes: application to CO2 activation

    Science.gov (United States)

    Bal, Kristof M.; Huygh, Stijn; Bogaerts, Annemie; Neyts, Erik C.

    2018-02-01

    Understanding the nature and effect of the multitude of plasma-surface interactions in plasma catalysis is a crucial requirement for further process development and improvement. A particularly intriguing and rather unique property of a plasma-catalytic setup is the ability of the plasma to modify the electronic structure, and hence chemical properties, of the catalyst through charging, i.e. the absorption of excess electrons. In this work, we develop a quantum chemical model based on density functional theory to study excess negative surface charges in a heterogeneous catalyst exposed to a plasma. This method is specifically applied to investigate plasma-catalytic CO2 activation on supported M/Al2O3 (M = Ti, Ni, Cu) single atom catalysts. We find that (1) the presence of a negative surface charge dramatically improves the reductive power of the catalyst, strongly promoting the splitting of CO2 to CO and oxygen, and (2) the relative activity of the investigated transition metals is also changed upon charging, suggesting that controlled surface charging is a powerful additional parameter to tune catalyst activity and selectivity. These results strongly point to plasma-induced surface charging of the catalyst as an important factor contributing to the plasma-catalyst synergistic effects frequently reported for plasma catalysis.

  3. A Novel Active Online State of Charge Based Balancing Approach for Lithium-Ion Battery Packs during Fast Charging Process in Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Xiudong Cui

    2017-11-01

    Full Text Available Abstract: Non-uniformity of Lithium-ion cells in a battery pack is inevitable and has become the bottleneck to the pack capacity, especially in the fast charging process. Therefore, a balancing approach is essentially required. This paper proposes an active online cell balancing approach in a fast charging process using the state of charge (SOC as balancing criterion. The goal of this approach is to complete pack balancing within the limited charging time. An adaptive extended Kalman filter (AEKF is applied to estimate the pack cell SOC during the charging process to obtain accurate results under modeling errors and measurement noises. To implement the proposed AEKF, only one additional current sensor is required to obtain the current of each cell required for the SOC estimation. An experimental platform is established to verify the effectiveness of the proposed approach. The results show that the proposed balancing approach with the SOC as a balancing criterion can overcome the challenges of non-uniformity and flat voltage plateau and charge more capacity into a LiFePO4 battery pack than those with the terminal voltage as a balancing criterion in the fast charging process.

  4. Hydrogen storage by adsorption on activated carbon: investigation of the thermal effects during the charging process

    International Nuclear Information System (INIS)

    Hermosilla-Lara, G.

    2007-02-01

    This work presents an experimental and numerical investigation of the thermal effects occurring during the charge of adsorbent fixed bed tank. The influence of these thermal effects, which result from the exothermal character of the adsorption process and the pressure forces work, on the storage capacity is specially analysed. An experimental setup allowing the dynamic measurements of the temperature and pressure profiles has been used. Then the numerical protocol with the Fluent software, has been validated by comparison of the simulated pressure, flow rate and temperature fields in the tank with the results obtained from an experimental investigation carried out the dynamic storage. Several predictive simulations have been carried out in order to study the effect of the boundary conditions, as the wall temperature or effective thermal conductivity of the porous bed, on the storage capacity of the reservoir. We searched the optimal geometry of an interbed thermal dissipator for a given industrial tank. To do this we made vary the H/L ratio, which represents the ratio of the height of an elementary stage and the total length of the tank. We could determine an optimal geometry which corresponds to the value 1/3 of the ratio H/L. From this optimum we studied the effect of five additional cooling tubes on the tank storage capacity. The stored mass is 15 % higher than that obtained without these tubes. (author)

  5. Features of destruction of solids by laser radiation in process of formation of multiply charged ions

    International Nuclear Information System (INIS)

    Bedilov, R.M.; Bedilov, M.R.; Sabitov, M.M.; Matnazarov, A.; Niyozov, B.

    2004-01-01

    Full text: It is known, under interaction of laser radiation with solid surface a power density q > 0.01 W/cm 2 are observed destruction of a solid and issue of electrons, ions, neutrals, neutrons, plasmas, and also radiation in a wide ranges of a spectra. Despite of a plenty of works, devoted to study of processes of interaction, the studies of feature of destruction of solids by laser beam in process of formation multiply charged ions are insufficiently investigated. The results of study feature of destruction of solids by laser radiation in process of formation multiply charged ions are given in this work. In our experiments, we used the mass spectrometer with single-channel laser radiation. The laser installation had the following parameters: a power density of laser radiation q=(0.1-50) GW/cm 2 ; the angle of incidence a=18 deg. to the target surface Al, (W). It was obtained experimentally dynamics of morphology of destruction and also mass - charge and energy spectra of multiply charged ions formed under interaction of laser radiation with Al (W) in the intensity range q=(0.1-50) GW/cm 2 . These studies showed features of destruction Al(W) by laser radiation, i.e. invariable of value evaporation mass from a surface of a solid increase as the laser intensity q. But thus temperature a pair increases in accordance with increase of flow density of a laser radiation. Increase of temperature the pair gives in formation of multiply charged plasma. It is typical that, as q of the laser increases the maximum charge number of ions in laser plasma considerably increase and their energy spectra extend toward higher energies. For example, under q=0.1 GW/cm 2 and 50 GW/cm 2 the maximum charge number of ions Al (W) are equal to Z max = 1 and 7, respectively. From the experimental data obtained, we can conclude that, the formed multiply charged plasma practically completely absorption laser radiation and 'shielding' a target surface for various metals at power densities

  6. Charge Islands Through Tunneling

    Science.gov (United States)

    Robinson, Daryl C.

    2002-01-01

    It has been recently reported that the electrical charge in a semiconductive carbon nanotube is not evenly distributed, but rather it is divided into charge "islands." This paper links the aforementioned phenomenon to tunneling and provides further insight into the higher rate of tunneling processes, which makes tunneling devices attractive. This paper also provides a basis for calculating the charge profile over the length of the tube so that nanoscale devices' conductive properties may be fully exploited.

  7. Temperature effect on protection diode for plasma-process induced charging damage

    NARCIS (Netherlands)

    Wang, Zhichun; Scarpa, A.; Smits, Sander M.; Kuper, F.G.; Salm, Cora

    2002-01-01

    In this paper, the leakage current of different drain-well diodes for plasma-charging protection has been simulated at high temperature. The simulation shows that the high ambient temperature, especially during plasma deposition process, enormously enhances the efficacy of the protection diodes in

  8. Orbital diamagnetism of a charged Brownian particle undergoing birth-death process

    International Nuclear Information System (INIS)

    Jayannawar, A.M.; Kumar, N.

    1980-06-01

    We consider the magnetic response of a charged Brownian particle undergoing a stochastic birth-death process. The latter simulates the electron-hole pair production and recombination in semiconductors. We obtain non-zero, orbital diamagnetism which can be large without violating the Van Leeuwen theorem. (author)

  9. Charge Carrier Trapping Processes in RE2O2S (RE = La, Gd, Y, and Lu)

    NARCIS (Netherlands)

    Luo, H.; Bos, A.J.J.; Dorenbos, P.

    2017-01-01

    Two different charge carrier trapping processes have been investigated in RE2O2S:Ln3+ (RE = La, Gd, Y, and Lu; Ln = Ce, Pr, and Tb) and RE2O2S:M (M = Ti4+ and Eu3+). Cerium, praseodymium and terbium act as recombination centers and hole trapping centers while host intrinsic defects provide the

  10. Effects of charged Higgs bosons in the deep inelastic process ντ N ...

    Indian Academy of Sciences (India)

    the value of the contribution of the W± exchange diagrams, provided MH± .... section rates of the charged current deep inelastic process ντ N in the frame of the ..... rates do not depend on the choice of the cuts on the momentum transfer square.

  11. Quasiparticle conductance-voltage characteristics for break junctions involving d-wave superconductors: charge-density-wave effects.

    Science.gov (United States)

    Ekino, T; Gabovich, A M; Suan Li, Mai; Szymczak, H; Voitenko, A I

    2017-12-20

    Quasiparticle tunnel conductance-voltage characteristics (CVCs), [Formula: see text], were calculated for break junctions (BJs) made up of layered d-wave superconductors partially gapped by charge-density waves (CDWs). The current is assumed to flow in the ab-plane of electrodes. The influence of CDWs is analyzed by comparing the resulting CVCs with CVCs calculated for BJs made up of pure d-wave superconductors with relevant parameters. The main CDW-effects were found to be the appearance of new CVC peculiarities and the loss of CVC symmetry with respect to the V-sign. Tunnel directionality was shown to be one of the key factors in the formation of [Formula: see text] dependences. In particular, the orientation of electrodes with respect to the current channel becomes very important. As a result, [Formula: see text] can acquire a large variety of forms similar to those for tunnel junctions between superconductors with s-wave, d-wave, and mixed symmetry of their order parameters. The diversity of peculiarities is especially striking at finite temperatures. In the case of BJs made up of pure d-wave superconductors, the resulting CVC can include a two-peak gap-driven structure. The results were compared with the experimental BJ data for a number of high-T c oxides. It was shown that the large variety of the observed current-voltage characteristics can be interpreted in the framework of our approach. Thus, quasiparticle tunnel currents in the ab-plane can be used as an additional mean to detect CDWs competing with superconductivity in cuprates or other layered superconductors.

  12. High-frequency conductivity of optically excited charge carriers in hydrogenated nanocrystalline silicon investigated by spectroscopic femtosecond pump–probe reflectivity measurements

    Energy Technology Data Exchange (ETDEWEB)

    He, Wei [University of Birmingham, School of Physics and Astronomy, Birmingham B15 2TT (United Kingdom); Yurkevich, Igor V. [Aston University, Nonlinearity and Complexity Research Group, Birmingham B4 7ET (United Kingdom); Zakar, Ammar [University of Birmingham, School of Physics and Astronomy, Birmingham B15 2TT (United Kingdom); Kaplan, Andrey, E-mail: a.kaplan.1@bham.ac.uk [University of Birmingham, School of Physics and Astronomy, Birmingham B15 2TT (United Kingdom)

    2015-10-01

    We report an investigation into the high-frequency conductivity of optically excited charge carriers far from equilibrium with the lattice. The investigated samples consist of hydrogenated nanocrystalline silicon films grown on a thin film of silicon oxide on top of a silicon substrate. For the investigation, we used an optical femtosecond pump–probe setup to measure the reflectance change of a probe beam. The pump beam ranged between 580 and 820 nm, whereas the probe wavelength spanned 770 to 810 nm. The pump fluence was fixed at 0.6 mJ/cm{sup 2}. We show that at a fixed delay time of 300 fs, the conductivity of the excited electron–hole plasma is described well by a classical conductivity model of a hot charge carrier gas found at Maxwell–Boltzmann distribution, while Fermi–Dirac statics is not suitable. This is corroborated by values retrieved from pump–probe reflectance measurements of the conductivity and its dependence on the excitation wavelength and carrier temperature. The conductivity decreases monotonically as a function of the excitation wavelength, as expected for a nondegenerate charge carrier gas. - Highlights: • We study high‐frequency conductivity of excited hydrogenated nanocrystalline silicon. • Reflectance change was measured as a function of pump and probe wavelength. • Maxwell–Boltzmann transport theory was used to retrieve the conductivity. • The conductivity decreases monotonically as a function of the pump wavelength.

  13. Charged particle multiplicity distributions in e+e--annihilation processes in the LEP experiments

    International Nuclear Information System (INIS)

    Shlyapnikov, P.V.

    1992-01-01

    Results of studies of the charged particle multiplicity distributions in the process of e + e - -annihilation into hadrons obtained in experiments at LEP accelerator in CERN are reviewed. Universality in energy dependence of the average charged particle multiplicity in e + e - and p ± p collisions, evidence for KNO-scaling in e + e - data, structure in multiplicity distribution and its relation to the jet structure of events, average particle multiplicities or quark and gluon jets, 'clan' picture and other topics are discussed. 73 refs.; 20 figs.; 3 tabs

  14. Mechanisms of dust grain charging in plasma with allowance for electron emission processes

    Energy Technology Data Exchange (ETDEWEB)

    Mol’kov, S. I.; Savin, V. N., E-mail: moped@onego.ru [Petrozavodsk State University (Russian Federation)

    2017-02-15

    The process of dust grain charging is described with allowance for secondary, ion-induced, photoelectric, and thermal electron emission from the grain surface. The roughness of the grain surface is taken into account. An intermediate charging regime involving ion–atom collisions and electron ionization in the perturbed plasma region is analyzed using the moment equations and Poisson’s equation. A calculation method is proposed that allows one to take into account the influence of all the above effects and determine the radius of the plasma region perturbed by the dust grain.

  15. Noncontact COS charge analysis for in-line monitoring of wet cleaning processes

    Science.gov (United States)

    Zhang, Xiafang; Juang, Min; Tai, Sung-Shan; Chen, Kuo-in; Wossen, Ejigu; Horner, Gregory

    1998-08-01

    Contamination levels in chemical cleaning equipment and wafer cleanliness in general are very critical to semiconductor manufacturers. In this work, a Keithley Instruments non contact electrical tester (Quantox) is used to measure the mobile ion (Qm) contamination in a variety of cleaning processes. Results show that photoresist strip cleaning process has a higher mobile ion concentration than standard pre-diffusion cleaning process. RCA1, RCA2 and HF solutions mapping measured by the Quantox indicates some negative static charges on the surface after cleaning. This negative field appears to assist Qm removal during wet chemical cleaning. The dependence of flatband voltage and other oxide charges on various cleaning processes has also been investigated using the Quantox. The data suggests that a dipole layer has been formed by a surface reaction during chemical cleaning.

  16. Mathematical model of silicon smelting process basing on pelletized charge from technogenic raw materials

    Science.gov (United States)

    Nemchinova, N. V.; Tyutrin, A. A.; Salov, V. M.

    2018-03-01

    The silicon production process in the electric arc reduction furnaces (EAF) is studied using pelletized charge as an additive to the standard on the basis of the generated mathematical model. The results obtained due to the model will contribute to the analysis of the charge components behavior during melting with the achievement of optimum final parameters of the silicon production process. The authors proposed using technogenic waste as a raw material for the silicon production in a pelletized form using liquid glass and aluminum production dust from the electrostatic precipitators as a binder. The method of mathematical modeling with the help of the ‘Selector’ software package was used as a basis for the theoretical study. A model was simulated with the imitation of four furnace temperature zones and a crystalline silicon phase (25 °C). The main advantage of the created model is the ability to analyze the behavior of all burden materials (including pelletized charge) in the carbothermic process. The behavior analysis is based on the thermodynamic probability data of the burden materials interactions in the carbothermic process. The model accounts for 17 elements entering the furnace with raw materials, electrodes and air. The silicon melt, obtained by the modeling, contained 91.73 % wt. of the target product. The simulation results showed that in the use of the proposed combined charge, the recovery of silicon reached 69.248 %, which is in good agreement with practical data. The results of the crystalline silicon chemical composition modeling are compared with the real silicon samples of chemical analysis data, which showed the results of convergence. The efficiency of the mathematical modeling methods in the studying of the carbothermal silicon obtaining process with complex interphase transformations and the formation of numerous intermediate compounds using a pelletized charge as an additive to the traditional one is shown.

  17. Electronic transport in single-helical protein molecules: Effects of multiple charge conduction pathways and helical symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Sourav, E-mail: sourav.kunduphy@gmail.com; Karmakar, S.N.

    2016-07-15

    We propose a tight-binding model to investigate electronic transport properties of single helical protein molecules incorporating both the helical symmetry and the possibility of multiple charge transfer pathways. Our study reveals that due to existence of both the multiple charge transfer pathways and helical symmetry, the transport properties are quite rigid under influence of environmental fluctuations which indicates that these biomolecules can serve as better alternatives in nanoelectronic devices than its other biological counterparts e.g., single-stranded DNA.

  18. Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ

    Directory of Open Access Journals (Sweden)

    Raúl García

    2015-06-01

    Full Text Available We describe the synthesis and single-molecule electrical transport properties of a molecular wire containing a π-extended tetrathiafulvalene (exTTF group and its charge-transfer complex with F4TCNQ. We form single-molecule junctions using the in situ break junction technique using a homebuilt scanning tunneling microscope with a range of conductance between 10 G0 down to 10−7 G0. Within this range we do not observe a clear conductance signature of the neutral parent molecule, suggesting either that its conductance is too low or that it does not form a stable junction. Conversely, we do find a clear conductance signature in the experiments carried out on the charge-transfer complex. Due to the fact we expected this species to have a higher conductance than the neutral molecule, we believe this supports the idea that the conductance of the neutral molecule is very low, below our measurement sensitivity. This idea is further supported by theoretical calculations. To the best of our knowledge, these are the first reported single-molecule conductance measurements on a molecular charge-transfer species.

  19. Dynamic simulation of charging processes in polar dielectrics irradiated by the electron bunches of middle level energy

    International Nuclear Information System (INIS)

    Maslovskaya, A.G.

    2011-01-01

    Nowadays the scanning electron microscopy techniques are widely used practically in condenser matter physics to study properties and structure of solids. The electron probe of scanning electron microscope is not merely a passive indicator of the geometrical or potential profile of the sample surface, but also the source producing ionizing, electric and thermal action on the sample. The application of raster electron methods to polar materials, responding to electric and heat exposures of the electron bunches allows us to get a response and create new modes of image formation. Let assume, that a sample surface of dielectric is irradiated by thin focused electron bunches of middle level energy (with order 1÷50 keV). When electrons bombard the dielectric sample the accumulation of absorbed electrons occurs. As a result generated charged areas can irregular drift the initial bunches. Charging effect occurs at any magnifications and any actual probe current. This work considers the results of dynamic simulation of charging process in polar dielectrics under the investigation with the scanning electron microscope. The purpose of present study is design and model implementation of three-dimensional dynamic model of charge relaxation in polar materials irradiated by electron bunches of middle level energy. The mathematical problem definition is given by the system of the continuity equation and Poisson equation. Final system of equations was modified in terms of intrinsic radiation-induced conductivity in sample as well as cylindrical symmetry of the problem. The simulation is based on numerical method solving of boundary problem for partial derivative equation system. In addition the initial electron distribution is determined by Monte-Carlo method using the programming implementation. To solve this problem we used the computational methods of solution of nonstationary mathematical physics problem such as finite difference method and finite element method realized with

  20. The effect of the Grain-Boundary and surface scattering of charge carriers on electrical conductance of thin V and Re films

    International Nuclear Information System (INIS)

    Lakh, Kh.G.; Stasyuk, Z.V.

    1994-01-01

    Size effects in electrical conductivity and the Hall coefficient of thin V and Re films have been investigated. An analysis of experimental data was made within the framework of modified Mayadas -Shatzkes and Tellier - Tosser - Pichard models. The parameters of charge transport for V and Re have been found

  1. Large deviations in stochastic heat-conduction processes provide a gradient-flow structure for heat conduction

    International Nuclear Information System (INIS)

    Peletier, Mark A.; Redig, Frank; Vafayi, Kiamars

    2014-01-01

    We consider three one-dimensional continuous-time Markov processes on a lattice, each of which models the conduction of heat: the family of Brownian Energy Processes with parameter m (BEP(m)), a Generalized Brownian Energy Process, and the Kipnis-Marchioro-Presutti (KMP) process. The hydrodynamic limit of each of these three processes is a parabolic equation, the linear heat equation in the case of the BEP(m) and the KMP, and a nonlinear heat equation for the Generalized Brownian Energy Process with parameter a (GBEP(a)). We prove the hydrodynamic limit rigorously for the BEP(m), and give a formal derivation for the GBEP(a). We then formally derive the pathwise large-deviation rate functional for the empirical measure of the three processes. These rate functionals imply gradient-flow structures for the limiting linear and nonlinear heat equations. We contrast these gradient-flow structures with those for processes describing the diffusion of mass, most importantly the class of Wasserstein gradient-flow systems. The linear and nonlinear heat-equation gradient-flow structures are each driven by entropy terms of the form −log ρ; they involve dissipation or mobility terms of order ρ 2 for the linear heat equation, and a nonlinear function of ρ for the nonlinear heat equation

  2. Solution processable semiconductor thin films: Correlation between morphological, structural, optical and charge transport properties

    Science.gov (United States)

    Isik, Dilek

    This Ph.D. thesis is a result of multidisciplinary research bringing together fundamental concepts in thin film engineering, materials science, materials processing and characterization, electrochemistry, microfabrication, and device physics. Experiments were conducted by tackling scientific problems in the field of thin films and interfaces, with the aim to correlate the morphology, crystalline structure, electronic structure of thin films with the functional properties of the films and the performances of electronic devices based thereon. Furthermore, novel strategies based on interfacial phenomena at electrolyte/thin film interfaces were explored and exploited to control the electrical conductivity of the thin films. Three main chemical systems were the object of the studies performed during this Ph.D., two types of organic semiconductors (azomethine-based oligomers and polymers and soluble pentacene derivatives) and one metal oxide semiconductor (tungsten trioxide, WO3). To explore the morphological properties of the thin films, atomic force microscopy was employed. The morphological properties were further investigated by hyperspectral fluorescence microscopy and tentatively correlated to the charge transport properties of the films. X-ray diffraction (Grazing incidence XRD, GIXRD) was used to investigate the crystallinity of the film and the effect of the heat treatment on such crystallinity, as well as to understand the molecular arrangement of the organic molecules in the thin film. The charge transport properties of the films were evaluated in thin film transistor configuration. For electrolyte gated thin film transistors, time dependent transient measurements were conducted, in parallel to more conventional transistor characterizations, to explore the specific effects played on the gating by the anion and cation constituting the electrolyte. The capacitances of the electrical double layers at the electrolyte/WO3 interface were obtained from

  3. Nanoclay gelation approach toward improved dye-sensitized solar cell efficiencies: an investigation of charge transport and shift in the TiO2 conduction band.

    Science.gov (United States)

    Wang, Xiu; Kulkarni, Sneha A; Ito, Bruno Ieiri; Batabyal, Sudip K; Nonomura, Kazuteru; Wong, Chee Cheong; Grätzel, Michael; Mhaisalkar, Subodh G; Uchida, Satoshi

    2013-01-23

    Nanoclay minerals play a promising role as additives in the liquid electrolyte to form a gel electrolyte for quasi-solid-state dye-sensitized solar cells, because of the high chemical stability, unique swelling capability, ion exchange capacity, and rheological properties of nanoclays. Here, we report the improved performance of a quasi-solid-state gel electrolyte that is made from a liquid electrolyte and synthetic nitrate-hydrotalcite nanoclay. Charge transport mechanisms in the gel electrolyte and nanoclay interactions with TiO(2)/electrolyte interface are discussed in detail. The electrochemical analysis reveals that the charge transport is solely based on physical diffusion at the ratio of [PMII]:[I(2)] = 10:1 (where PMII is 1-propyl-3-methylimidazolium iodide). The calculated physical diffusion coefficient shows that the diffusion of redox ions is not affected much by the viscosity of nanoclay gel. The addition of nitrate-hydrotalcite clay in the electrolyte has the effect of buffering the protonation process at the TiO(2)/electrolyte interface, resulting in an upward shift in the conduction band and a boost in open-circuit voltage (V(OC)). Higher V(OC) values with undiminished photocurrent is achieved with nitrate-hydrotalcite nanoclay gel electrolyte for organic as well as for inorganic dye (D35 and N719) systems. The efficiency for hydrotalcite clay gel electrolyte solar cells is increased by 10%, compared to that of the liquid electrolyte. The power conversion efficiency can reach 10.1% under 0.25 sun and 9.6% under full sun. This study demonstrates that nitrate-hydrotalcite nanoclay in the electrolyte not only solidifies the liquid electrolyte to prevent solvent leakage, but also facilitates the improvement in cell efficiency.

  4. Search for lepton number violating charged current processes with neutrino beams

    International Nuclear Information System (INIS)

    Kanemura, Shinya; Kuno, Yoshitaka; Ota, Toshihiko

    2013-01-01

    We propose a novel idea on measurements to understand which physics mechanism is responsible for the origin of a small neutrino mass, by searching for the processes of lepton number violating charged current interaction with incident of a neutrino beam. It turns out that only the proposed measurements could provide a potential to discriminate the mechanisms, in particular the ones called loop-induced mechanisms of neutrino mass generation, from the others. The expected rates of these processes based on some theoretical assumptions are estimated. They are found to be sizable so that detection of such processes could be achievable at near detectors in future highly intense neutrino-beam facilities

  5. Conductive scanning probe microscopy of the semicontinuous gold film and its SERS enhancement toward two-step photo-induced charge transfer and effect of the supportive layer

    Science.gov (United States)

    Sinthiptharakoon, K.; Sapcharoenkun, C.; Nuntawong, N.; Duong, B.; Wutikhun, T.; Treetong, A.; Meemuk, B.; Kasamechonchung, P.; Klamchuen, A.

    2018-05-01

    The semicontinuous gold film, enabling various electronic applications including development of surface-enhanced Raman scattering (SERS) substrate, is investigated using conductive atomic force microscopy (CAFM) and Kelvin probe force microscopy (KPFM) to reveal and investigate local electronic characteristics potentially associated with SERS generation of the film material. Although the gold film fully covers the underlying silicon surface, CAFM results reveal that local conductivity of the film is not continuous with insulating nanoislands appearing throughout the surface due to incomplete film percolation. Our analysis also suggests the two-step photo-induced charge transfer (CT) play the dominant role in the enhancement of SERS intensity with strong contribution from free electrons of the silicon support. Silicon-to-gold charge transport is illustrated by KPFM results showing that Fermi level of the gold film is slightly inhomogeneous and far below the silicon conduction band. We propose that inhomogeneity of the film workfunction affecting chemical charge transfer between gold and Raman probe molecule is associated with the SERS intensity varying across the surface. These findings provide deeper understanding of charge transfer mechanism for SERS which can help in design and development of the semicontinuous gold film-based SERS substrate and other electronic applications.

  6. A data processing unit (DPU) for a satellite-borne charge composition experiment

    International Nuclear Information System (INIS)

    Koga, R.; Blake, J.B.; Chenette, D.L.; Fennell, J.F.; Imamoto, S.S.; Katz, N.; King, C.G.

    1985-01-01

    A data processing unit (DPU) for use with a charge composition experiment to be flown aboard the VIKING auroral research satellite is described. The function of this experiment is to measure the mass, charge state, energy, and pitch-angle distribution of ions in the earth's high-altitude magnetosphere in the energy range from 50 keV/q to 300 keV/q. In order to be compatible with the spacecraft telemetry limitations, raw sensor data are processed in the DPU using on-board composition analysis and the scalar compression. The design of this DPU is such that it can be readily adapted to a variety of space composition experiments. Special attention was given to the effect of the radiation environment on orbit since a microprocessor and a relatively large number of random access memories (RAMs) comprise a considerable portion of the DPU

  7. Simulation of the charging process of the LISA test masses due to solar flares

    International Nuclear Information System (INIS)

    Vocca, H; Grimani, C; Amico, P; Bosi, L; Marchesoni, F; Punturo, M; Travasso, F; Barone, M; Stanga, R; Vetrano, F; Vicere, A

    2004-01-01

    Cosmic-ray and solar high energy particles penetrate the LISA experiment test masses. Consequently, an electric charge accumulates in the bodies of the masses, generating spurious Coulomb forces between the masses and the surrounding electrodes. This process increases the noise level of the experiment. We have estimated the amount of charge deposited per second on the LISA test masses by solar flares and primary cosmic-ray protons at solar minimum. The simulation has been carried out with the Fluka Monte Carlo program. A simplified geometry for the experiment has been considered. We have found a net charging rate of 37 ± 1 e + /s for primary protons at solar minimum between 0.1 and 1000 GeV/n. The amount of charge released by a medium-strong solar flare, like that of 16 February 1984, is 10 732 ± 30 e + /s in the energy range 0.1-10 GeV/n. This value increases or decreases by approximately one order of magnitude for strong (weak) solar flares

  8. Charge dependence and charge asymmetry in the nucleon-nucleon interaction due to processes involving Δ's

    International Nuclear Information System (INIS)

    Wells, T.B.

    1978-01-01

    The charge dependence and charge asymmetry of the nucleon-nucleon force arising from the exchange of a pion and a photon with the excitation of a nucleon resonance [Δ(1236)] is calculated. This charge dependence and asymmetry is studied through its effects on the 1 S nucleon-nucleon scattering lengths. The complexity of the calculation forces the use of approximations. The calculation is performed first with a pole approximation for the resonance and a second time with a Chew-Low description of the resonance. Both calculations neglect nuclear recoil. Estimates of this effect are made. The changes in the scattering lengths are small ( +- / 2 = 1.0225 G/sub π 0 / 2 will explain the proton-neutron scattering length

  9. Efficient green phosphorescent tandem organic light emitting diodes with solution processable mixed hosts charge generating layer

    Energy Technology Data Exchange (ETDEWEB)

    Talik, N.A.; Yeoh, K.H.; Ng, C.Y.B [Low Dimensional Research Center, Department of Physics, University Malaya, 50603 Kuala Lumpur (Malaysia); ItraMAS Corporation. Sdn. Bhd., 542A-B Mukim 1, Lorong Perusahaan Baru 2, Kawasan Perindustrian, Perai 13600, Penang (Malaysia); Yap, B.K. [Center of Microelectronic and Nanotechnology Engineering (CeMNE), College of Engineering, Universiti Tenaga Nasional, Jln. Uniten-Ikram, 4300 Kajang, Selangor (Malaysia); Woon, K.L., E-mail: ph7klw76@um.edu.my [Low Dimensional Research Center, Department of Physics, University Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-10-15

    A novel solution processable charge generating layer (CGL) that consists of 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HATCN{sub 6})/Poly(N-vinylcarbazole) (PVK): 1,1-bis-(4-bis(4-tolyl)-aminophenyl) cyclohexene (TAPC) for a tandem green phosphorescent organic light emitting diode (PHOLED) is demonstrated. The use of orthogonal solvent to dissolve HATCN{sub 6} and PVK:TAPC is the key to overcome the interface erosion problem for the solution processed CGL. The current efficiency of the 2 wt% TAPC mixed with PVK is the highest at 24.2 cd/A, which is more than three-folds higher than that of the single device at 1000 cd/m{sup 2}. - Highlights: • A solution processable tandem OLED is built using a novel charge generating layer. • HATCN{sub 6} and PVK:TAPC are shown to be effective charge generating layers. • The turn on voltages for tandem devices are almost similar to single unit. • 2 wt% TAPC blended with PVK exhibits three-folds increase in efficiency.

  10. Discussion of Carbon Emissions for Charging Hot Metal in EAF Steelmaking Process

    Science.gov (United States)

    Yang, Ling-zhi; Jiang, Tao; Li, Guang-hui; Guo, Yu-feng

    2017-07-01

    As the cost of hot metal is reduced for iron ore prices are falling in the international market, more and more electric arc furnace (EAF) steelmaking enterprises use partial hot metal instead of scrap as raw materials to reduce costs and the power consumption. In this paper, carbon emissions based on 1,000 kg molten steel by charging hot metal in EAF steelmaking is studied. Based on the analysis of material and energy balance calculation in EAF, the results show that 146.9, 142.2, 137.0, and 130.8 kg/t of carbon emissions are produced at a hot metal ratio of 0 %, 30 %, 50 %, and 70 %, while 143.4, 98.5, 65.81, and 31.5 kg/t of carbon emissions are produced at a hot metal ratio of 0 %, 30 %, 50 %, and 70 % by using gas waste heat utilization (coal gas production) for EAF steelmaking unit process. However, carbon emissions are increased by charging hot metal for the whole blast furnace-electric arc furnace (BF-EAF) steelmaking process. In the condition that the hot metal produced by BF is surplus, as carbon monoxide in gas increased by charging hot metal, the way of coal gas production can be used for waste heat utilization, which reduces carbon emissions in EAF steelmaking unit process.

  11. Charge imbalance

    International Nuclear Information System (INIS)

    Clarke, J.

    1981-01-01

    This article provides a long theoretical development of the main ideas of charge imbalance in superconductors. Concepts of charge imbalance and quasiparticle charge are introduced, especially in regards to the use of tunnel injection in producing and detecting charge imbalance. Various mechanisms of charge relaxation are discussed, including inelastic scattering processes, elastic scattering in the presence of energy-gap anisotropy, and various pair-breaking mechanisms. In each case, present theories are reviewed in comparison with experimental data

  12. Process for charging batteries and circuit for carrying out the process. Verfahren zum Laden von Batterien und Schaltung zur Durchfuehrung des Verfahrens

    Energy Technology Data Exchange (ETDEWEB)

    Grauel, B

    1992-03-05

    The invention concerns a process for charging batteries and a circuit for carrying out the process. First, in a test routine, the battery temperature, the correct polarity of the battery and the actual state of battery charge are measured and the number of cells is determined from the battery no-load voltage. If this falls below the reference no-load voltage, the charging current is repeatedly switched on for a predetermined period of time, and the battery voltage is measured. If an equilibrium voltage predetermined by heating of the battery cells is determined, the battery is charged for a predetermined period of time, until the charged capacity has reached the nominal capacity. Then a maintenance charge to maintain the batter capacity is provided at a time space after the charge.

  13. Bane of Hydrogen-Bond Formation on the Photoinduced Charge-Transfer Process in Donor–Acceptor Systems

    KAUST Repository

    Alsam, Amani Abdu; Adhikari, Aniruddha; Parida, Manas R.; Aly, Shawkat Mohammede; Bakr, Osman; Mohammed, Omar F.

    2017-01-01

    Controlling the ultrafast dynamical process of photoinduced charge transfer at donor acceptor interfaces remains a major challenge for physical chemistry and solar cell communities. The process is complicated by the involvement of other complex

  14. Management von Article Processing Charges - Herausforderungen für Bibliotheken

    Directory of Open Access Journals (Sweden)

    Kai Geschuhn

    2015-03-01

    Full Text Available Seit mehreren Jahren betreiben Hochschulbibliotheken Publikationsfonds, um Open-Access-Artikelgebühren, Article Processing Charges, für die Autorinnen und Autoren ihrer Einrichtungen zu übernehmen. Der dynamische Anstieg der Open-Access-Publikationen in den letzten Jahren wirft die Frage auf, ob die derzeitigen Verfahren zwischen Verlagen und wissenschaftlichen Einrichtungen stabil genug sind und bei einer vollständigen Umstellung auf Open Access skalieren. Die Max Planck Digital Library übernimmt derzeit jährlich zentral Gebühren für etwa 600 Open-Access-Artikel aus der Max-Planck-Gesellschaft. Der Beitrag gibt einen Überblick über die strategischen Hintergründe dieser zentralen Kostenübernahme und zeigt anschließend die einzelnen Prozessschritte sowie die Hürden hierbei auf. Die größten Desiderate im Hinblick auf die Etablierung effizienter und nachhaltiger Prozesse sind optimierte Artikel-Einreichungssysteme, eine bessere Autorenidentifizierung sowie ein vereinheitlichtes, verbessertes Reporting. Dedicated funds for Open Access publishing have been a strategic instrument at German university libraries for some years. The dynamically growing number of Open Access publications raises the question whether the processes for handling article processing charges (APC between libraries and publishers are organized sustainably enough to support a full transition to Open Access. On behalf of Max Planck researchers, the Max Planck Digital Library centrally processes about 600 invoices for Open Access articles per year. This paper explains the strategic background and also describes the individual steps which are necessary for assuming charges centrally and the barriers which can emerge during this process. In order to establish smooth and scalable processes, the main desiderata are the optimization of article submitting systems, a better author identification and allocation, and improved reporting.

  15. Comparative biology approaches for charged particle exposures and cancer development processes

    Science.gov (United States)

    Kronenberg, Amy; Gauny, Stacey; Kwoh, Ely; Sudo, Hiroko; Wiese, Claudia; Dan, Cristian; Turker, Mitchell

    Comparative biology studies can provide useful information for the extrapolation of results be-tween cells in culture and the more complex environment of the tissue. In other circumstances, they provide a method to guide the interpretation of results obtained for cells from differ-ent species. We have considered several key cancer development processes following charged particle exposures using comparative biology approaches. Our particular emphases have been mutagenesis and genomic instability. Carcinogenesis requires the accumulation of mutations and most of htese mutations occur on autosomes. Two loci provide the greatest avenue for the consideration of charged particle-induced mutation involving autosomes: the TK1 locus in human cells and the APRT locus in mouse cells. Each locus can provide information on a wide variety of mutational changes, from small intragenic mutations through multilocus dele-tions and extensive tracts of mitotic recombination. In addition, the mouse model can provide a direct measurement of chromosome loss which cannot be accomplished in the human cell system. Another feature of the mouse APRT model is the ability to examine effects for cells exposed in vitro with those obtained for cells exposed in situ. We will provide a comparison of the results obtained for the TK1 locus following 1 GeV/amu Fe ion exposures to the human lymphoid cells with those obtained for the APRT locus for mouse kidney epithelial cells (in vitro or in situ). Substantial conservation of mechanisms is found amongst these three exposure scenarios, with some differences attributable to the specific conditions of exposure. A similar approach will be applied to the consideraiton of proton-induced autosomal mutations in the three model systems. A comparison of the results obtained for Fe ions vs. protons in each case will highlight LET-specificc differences in response. Another cancer development process that is receiving considerable interest is genomic instability. We

  16. Present status of theoretical understanding of charge changing processes at low beam energies

    OpenAIRE

    Swami, D. K.; Nandi, T.

    2017-01-01

    A model for the evaluation of charge-state distributions of fast heavy ions in solid targets is being developed since late eighties in terms of ETACHA code. Time to time it is being updated to deal with more number of electrons and non-perturbative processes. The calculation approach of the recent one, which is formulated for handling the non-perturbative processes better, is different from the earlier ones. However, the experimental results for the projectiles up to 28 electrons can be compa...

  17. A generalized multi-dimensional mathematical model for charging and discharging processes in a supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Allu, Srikanth [ORNL; Velamur Asokan, Badri [Exxon Mobil Research and Engineering; Shelton, William A [Louisiana State University; Philip, Bobby [ORNL; Pannala, Sreekanth [ORNL

    2014-01-01

    A generalized three dimensional computational model based on unied formulation of electrode- electrolyte-electrode system of a electric double layer supercapacitor has been developed. The model accounts for charge transport across the solid-liquid system. This formulation based on volume averaging process is a widely used concept for the multiphase ow equations ([28] [36]) and is analogous to porous media theory typically employed for electrochemical systems [22] [39] [12]. This formulation is extended to the electrochemical equations for a supercapacitor in a consistent fashion, which allows for a single-domain approach with no need for explicit interfacial boundary conditions as previously employed ([38]). In this model it is easy to introduce the spatio-temporal variations, anisotropies of physical properties and it is also conducive for introducing any upscaled parameters from lower length{scale simulations and experiments. Due to the irregular geometric congurations including porous electrode, the charge transport and subsequent performance characteristics of the super-capacitor can be easily captured in higher dimensions. A generalized model of this nature also provides insight into the applicability of 1D models ([38]) and where multidimensional eects need to be considered. In addition, simple sensitivity analysis on key input parameters is performed in order to ascertain the dependence of the charge and discharge processes on these parameters. Finally, we demonstarted how this new formulation can be applied to non-planar supercapacitors

  18. Energy loss and charge exchange processes of high energy heavy ions channeled in crystals

    International Nuclear Information System (INIS)

    Poizat, J.C.; Andriamonje, S.; Anne, R.; Faria, N.V.d.C.; Chevallier, M.; Cohen, C.; Dural, J.; Farizon-Mazuy, B.; Gaillard, M.J.; Genre, R.; Hage-Ali, M.; Kirsch, R.; L'hoir, A.; Mory, J.; Moulin, J.; Quere, Y.; Remillieux, J.; Schmaus, D.; Toulemonde, M.

    1990-01-01

    The interaction of moving ions with single crystals is very sensitive to the orientation of the incident beam with respect to the crystalline directions of the target. Our experiments show that high energy heavy ion channeling deeply modifies their slowing down and charge exchange processes. This is due to the fact that channeled ions interact only with outershell target electrons, which means that the electron density they experience is very low and that the binding energy, and then the momentum distribution of these electrons, are quite different from the corresponding average values associated to random incidence. The two experimental studies presented here show the reduction of the energy loss rate for fast channeled heavy ions and illustrate the two aspects of channeling effects on charge exchange, the reduction of electron loss on one hand, and of electron capture on the other hand

  19. One- and two-electron processes in collisions between hydrogen molecules and slow highly charged ions

    International Nuclear Information System (INIS)

    Wells, E.; Carnes, K.D.; Tawara, H.; Ali, R.; Sidky, Emil Y.; Illescas, Clara; Ben-Itzhak, I.

    2005-01-01

    A coincidence time-of-flight technique coupled with projectile charge state analysis was used to study electron capture in collisions between slow highly charged ions and hydrogen molecules. We found single electron capture with no target excitation to be the dominant process for both C 6+ projectiles at a velocity of 0.8 atomic units and Ar 11+ projectiles at v 0.63 a.u. Double electron capture and transfer excitation, however, were found to be comparable and occur about 30% of the time relative to single capture. Most projectiles (96%) auto-ionize quickly following double capture into doubly excited states. The data are compared to classical and quantum mechanical model calculations

  20. Mechanisms of charge transfer and redistribution in LaAlO3/SrTiO3 revealed by high-energy optical conductivity.

    Science.gov (United States)

    Asmara, T C; Annadi, A; Santoso, I; Gogoi, P K; Kotlov, A; Omer, H M; Motapothula, M; Breese, M B H; Rübhausen, M; Venkatesan, T; Ariando; Rusydi, A

    2014-04-14

    In condensed matter physics the quasi two-dimensional electron gas at the interface of two different insulators, polar LaAlO3 on nonpolar SrTiO3 (LaAlO3/SrTiO3) is a spectacular and surprising observation. This phenomenon is LaAlO3 film thickness dependent and may be explained by the polarization catastrophe model, in which a charge transfer of 0.5e(-) from the LaAlO3 film into the LaAlO3/SrTiO3 interface is expected. Here we show that in conducting samples (≥ 4 unit cells of LaAlO3) there is indeed a ~0.5e(-) transfer from LaAlO3 into the LaAlO3/SrTiO3 interface by studying the optical conductivity in a broad energy range (0.5-35 eV). Surprisingly, in insulating samples (≤ 3 unit cells of LaAlO3) a redistribution of charges within the polar LaAlO3 sublayers (from AlO2 to LaO) as large as ~0.5e(-) is observed, with no charge transfer into the interface. Hence, our results reveal the different mechanisms for the polarization catastrophe compensation in insulating and conducting LaAlO3/SrTiO3 interfaces.

  1. Density functional theory for the description of charge-transfer processes at TTF/TCNQ interfaces

    KAUST Repository

    Van Regemorter, Tanguy; Guillaume, Maxime; Sini, Gjergji; Sears, John S.; Geskin, Victor; Bré das, Jean-Luc; Beljonne, David; Cornil, Jé rô me

    2012-01-01

    In the field of organic electronics, a central issue is to assess how the frontier electronic levels of two adjacent organic layers align with respect to one another at the interface. This alignment can be driven by the presence of a partial charge transfer and the formation of an interface dipole; it plays a key role for instance in determining the rates of exciton dissociation or exciton formation in organic solar cells or light-emitting diodes, respectively. Reliably modeling the processes taking place at these interfaces remains a challenge for the computational chemistry community. Here, we review our recent theoretical work on the influence of the choice of density functional theory (DFT) methodology on the description of the charge-transfer character in the ground state of TTF/ TCNQ model complexes and interfaces. Starting with the electronic properties of the isolated TTF and TCNQ molecules and then considering the charge transfer and resulting interface dipole in TTF/TCNQ donor-acceptor stacks and bilayers, we examine the impact of the choice of DFT functional in describing the interfacial electronic structure. Finally, we employ computations based on periodic boundary conditions to highlight the impact of depolarization effects on the interfacial dipole moment. © Springer-Verlag 2012.

  2. Charge transfer processes on electrodes modified by polymer films of metal complexes with Schiff bases

    International Nuclear Information System (INIS)

    Levin, O.V.; Karushev, M.P.; Timonov, A.M.; Alekseeva, E.V.; Zhang, Shuanghua; Malev, V.V.

    2013-01-01

    Electrochemical properties of glassy carbon electrodes modified by two polymer films of different nickel complexes with Schiff base ligands containing methoxy substituents in their aromatic parts were studied in acetonitrile solutions with cyclic voltammetry, quartz crystal microbalance, atomic force microscopy, and impedance spectroscopy. It was observed that introduction of such substituents leads to a noticeable splitting of cycling voltammetric curves into at least two ox/red transitions. In addition, solvent flows accompanying the counter-ions ones during charging/discharge processes within the films appeared significantly greater than those observed in the case of non-substituted ligands. The obtained impedance results as a whole were satisfactorily treated in scope of the so-called model of homogeneous films with two kinds of charge carriers. However, determinations of the Warburg constant as a function of the electrode potential require additional verifications, at least in the ranges of overlapping ox/red transitions. In particular, it was established that in this region the impedance frequency dependence was some superposition of the diffusion (Warburg) and the pseudo-capacitive constituents. This, most likely, resulted from the presence of three kinds of charge carriers in the film interior

  3. Dust charging processes with a Cairns-Tsallis distribution function with negative ions

    International Nuclear Information System (INIS)

    Abid, A. A.; Khan, M. Z.; Yap, S. L.; Terças, H.; Mahmood, S.

    2016-01-01

    Dust grain charging processes are presented in a non-Maxwellian dusty plasma following the Cairns-Tsallis (q, α)–distribution, whose constituents are the electrons, as well as the positive/negative ions and negatively charged dust grains. For this purpose, we have solved the current balance equation for a negatively charged dust grain to achieve an equilibrium state value (viz., q d  = constant) in the presence of Cairns-Tsallis (q, α)–distribution. In fact, the current balance equation becomes modified due to the Boltzmannian/streaming distributed negative ions. It is numerically found that the relevant plasma parameters, such as the spectral indexes q and α, the positive ion-to-electron temperature ratio, and the negative ion streaming speed (U 0 ) significantly affect the dust grain surface potential. It is also shown that in the limit q → 1 the Cairns-Tsallis reduces to the Cairns distribution; for α = 0 the Cairns-Tsallis distribution reduces to pure Tsallis distribution and the latter reduces to Maxwellian distribution for q → 1 and α = 0

  4. Dust charging processes with a Cairns-Tsallis distribution function with negative ions

    Energy Technology Data Exchange (ETDEWEB)

    Abid, A. A., E-mail: abidaliabid1@hotmail.com [Applied Physics Department, Federal Urdu University of Arts, Science and Technology, Islamabad Campus, Islamabad 45320 (Pakistan); Khan, M. Z., E-mail: mzk-qau@yahoo.com [Applied Physics Department, Federal Urdu University of Arts, Science and Technology, Islamabad Campus, Islamabad 45320 (Pakistan); Plasma Technology Research Center, Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Yap, S. L. [Plasma Technology Research Center, Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Terças, H., E-mail: hugo.tercas@tecnico.ul.pt [Physics of Information Group, Instituto de Telecomunicações, Av. Rovisco Pais, Lisbon 1049-001 (Portugal); Mahmood, S. [Science Place, University of Saskatchewan, Saskatoon, Saskatchewan S7N5A2 (Canada)

    2016-01-15

    Dust grain charging processes are presented in a non-Maxwellian dusty plasma following the Cairns-Tsallis (q, α)–distribution, whose constituents are the electrons, as well as the positive/negative ions and negatively charged dust grains. For this purpose, we have solved the current balance equation for a negatively charged dust grain to achieve an equilibrium state value (viz., q{sub d} = constant) in the presence of Cairns-Tsallis (q, α)–distribution. In fact, the current balance equation becomes modified due to the Boltzmannian/streaming distributed negative ions. It is numerically found that the relevant plasma parameters, such as the spectral indexes q and α, the positive ion-to-electron temperature ratio, and the negative ion streaming speed (U{sub 0}) significantly affect the dust grain surface potential. It is also shown that in the limit q → 1 the Cairns-Tsallis reduces to the Cairns distribution; for α = 0 the Cairns-Tsallis distribution reduces to pure Tsallis distribution and the latter reduces to Maxwellian distribution for q → 1 and α = 0.

  5. Density functional theory for the description of charge-transfer processes at TTF/TCNQ interfaces

    KAUST Repository

    Van Regemorter, Tanguy

    2012-09-15

    In the field of organic electronics, a central issue is to assess how the frontier electronic levels of two adjacent organic layers align with respect to one another at the interface. This alignment can be driven by the presence of a partial charge transfer and the formation of an interface dipole; it plays a key role for instance in determining the rates of exciton dissociation or exciton formation in organic solar cells or light-emitting diodes, respectively. Reliably modeling the processes taking place at these interfaces remains a challenge for the computational chemistry community. Here, we review our recent theoretical work on the influence of the choice of density functional theory (DFT) methodology on the description of the charge-transfer character in the ground state of TTF/ TCNQ model complexes and interfaces. Starting with the electronic properties of the isolated TTF and TCNQ molecules and then considering the charge transfer and resulting interface dipole in TTF/TCNQ donor-acceptor stacks and bilayers, we examine the impact of the choice of DFT functional in describing the interfacial electronic structure. Finally, we employ computations based on periodic boundary conditions to highlight the impact of depolarization effects on the interfacial dipole moment. © Springer-Verlag 2012.

  6. Investigations of charge-changing processes for light proton-rich nuclei on carbon and solid-hydrogen targets

    Energy Technology Data Exchange (ETDEWEB)

    Sawahata, K. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Ozawa, A., E-mail: ozawa@tac.tsukuba.ac.jp [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Saito, Y.; Abe, Y.; Ichikawa, Y.; Inaba, N.; Ishibashi, Y. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Kitagawa, A. [National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Matsunaga, S. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Moriguchi, T.; Nagae, D.; Okada, S. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Sato, S. [National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Suzuki, S. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Suzuki, T.; Takeuchi, Y.; Yamaguchi, T. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Zenihiro, J. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan)

    2017-05-15

    We investigated charge-changing processes (total charge-changing cross sections and partial charge-changing cross sections) for light proton-rich nuclei ({sup 34–36}Ar, {sup 33}Cl, {sup 25–28}Si) at around 300A MeV on carbon and solid-hydrogen targets. We estimated the nuclear proton point radii of {sup 33}Cl and {sup 25,26,27}Si from the observed total charge-changing cross sections by using Glauber-model calculations with a phenomenological correction factor. Furthermore, we estimated the proton skin thickness for {sup 33}Cl coupled with its previously observed matter radius. From investigations of the partial charge-changing cross sections, clear zigzag pattern was observed for all isotopes. The present studies suggest that the pattern may be common in the proton-rich side, and depends on the odd–even nature of the fragment charge.

  7. Study of proton polarization in charge exchange process on optically oriented sodium atoms

    International Nuclear Information System (INIS)

    Zelenskij, A.N.; Kokhanovskij, S.A.

    1984-01-01

    Using high-power adjustable dye lasers for electron spin orientation in a charge-exchange target enables to significantly increase the proton polarization efficiency. A device is described that permits to avoid growth of the polarized proton beam emittance in a charge-exchange process in a strong magnetic field. The devise main feature is the use of an intensive source of neutral hydrogen atoms and the presence of a helium additional charge-exchange target which actualy is a proton ''source''. The helium charge-exchange cell is placed in the same magnetic field of a solenoid where a cell with oriented sodium is placed, a polarized electron being captured by a proton in the latter cell. In this case the beam at the solenoid inlet and outlet is in a neutral state; emittance growth related to the effect of end magnetic fields is not observed. The device after all prouduces polarized protons, their polarization degree is measured and the effect of various factors on polarization degree is studied. The description of the laser source and laser system is given. Measurement results have shown the beam intensity of neutral 7 keV atoms which passed through a polarizer to be 2 mA. The proton current doesn't depend. On the beeld fin the region of chrge exchange for the 8 kGs magnetic field. The degree of sodium polarization was 80% and polarized proton current approximately 70 μA at a temperature of the polarized sodium cell corresponding to the density of sodium vapar approximately 3x10 13 at/cm 2

  8. Simulation of neutron transport process, photons and charged particles within the Monte Carlo method

    International Nuclear Information System (INIS)

    Androsenko, A.A.; Androsenko, P.A.; Artamonov, S.N.; Bolonkina, G.V.; Lomtev, V.L.; Pupko, S.V.

    1991-01-01

    Description is given to the program system BRAND designed for the accurate solution of non-stationary transport equation of neutrons, photons and charged particles in the conditions of real three-dimensional geometry. An extensive set of local and non-local estimates provides an opportunity of calculating a great set of linear functionals normally being of interest in the calculation of reactors, radiation protection and experiment simulation. The process of particle interaction with substance is simulated on the basis of individual non-group data on each isotope of the composition. 24 refs

  9. Ab initio study of H + + H 2 collisions: Elastic/inelastic and charge transfer processes

    Science.gov (United States)

    Saieswari, A.; Kumar, Sanjay

    2007-12-01

    An ab initio full configuration interaction study has been undertaken to obtain the global potential energy surfaces for the ground and the first excited electronic state of the H + + H 2 system employing Dunning's cc-pVQZ basis set. Using the ab initio approach the corresponding quasi-diabatic potential energy surfaces and coupling potentials have been obtained. A time-independent quantum mechanical study has been also undertaken for both the inelastic and charge transfer processes at the experimental collision energy Ec.m. = 20.0 eV and the preliminary results show better agreement with the experimental data as compared to the earlier available theoretical studies.

  10. Image processing of integrated video image obtained with a charged-particle imaging video monitor system

    International Nuclear Information System (INIS)

    Iida, Takao; Nakajima, Takehiro

    1988-01-01

    A new type of charged-particle imaging video monitor system was constructed for video imaging of the distributions of alpha-emitting and low-energy beta-emitting nuclides. The system can display not only the scintillation image due to radiation on the video monitor but also the integrated video image becoming gradually clearer on another video monitor. The distortion of the image is about 5% and the spatial resolution is about 2 line pairs (lp)mm -1 . The integrated image is transferred to a personal computer and image processing is performed qualitatively and quantitatively. (author)

  11. Modelling of space-charge accumulation process in dielectrics of MDS structures under irradiation

    International Nuclear Information System (INIS)

    Gurtov, V.A.; Nazarov, A.I.; Travkov, I.V.

    1990-01-01

    Results of numerical modelling of radiation-induced space charge (RISC) accumulation in MOS structure silicon dioxide are given. Diffusion-drift model which takes account of trap heterogeneous distribution within dielectric volume and channeling of carriers captured at traps represents basis for calculations. Main physical processes affecting RISC accumulation are picked out and character of capture filling in dielectric volume under stress in MOS structure shutter during irradiation on the basis of comparison of experimental results for different thickness oxides with calculation data are predicted

  12. Bane of Hydrogen-Bond Formation on the Photoinduced Charge-Transfer Process in Donor–Acceptor Systems

    KAUST Repository

    Alsam, Amani Abdu

    2017-03-14

    Controlling the ultrafast dynamical process of photoinduced charge transfer at donor acceptor interfaces remains a major challenge for physical chemistry and solar cell communities. The process is complicated by the involvement of other complex dynamical processes, including hydrogen bond formation, energy transfer, and solvation dynamics occurring on similar time scales. In this study, we explore the remarkable impact of hydrogen-bond formation on the interfacial charge transfer between a negatively charged electron donating anionic porphyrin and a positively charged electron accepting pi-conjugated polymer, as a model system in solvents with different polarities and capabilities for hydiogen bonding using femtosecond transient absorption spectroscopy. Unlike the conventional understanding of the key role of hydrogen bonding in promoting the charge-transfer process, our steadystate and time-resolved results reveal that the intervening hydrogen-bonding environment and, consequently, the probable longer spacing between the donor and acceptor molecules significantly hinders the charge-transfer process between them. These results show that site-specific hydrogen bonding and geometric considerations between donor and acceptor can be exploited to control both the charge-transfer dynamics and its efficiency not only at donor acceptor interfaces but also in complex biological systems.

  13. Use of the NASA Space Radiation Laboratory at Brookhaven National Laboratory to Conduct Charged Particle Radiobiology Studies Relevant to Ion Therapy.

    Science.gov (United States)

    Held, Kathryn D; Blakely, Eleanor A; Story, Michael D; Lowenstein, Derek I

    2016-06-01

    Although clinical studies with carbon ions have been conducted successfully in Japan and Europe, the limited radiobiological information about charged particles that are heavier than protons remains a significant impediment to exploiting the full potential of particle therapy. There is growing interest in the U.S. to build a cancer treatment facility that utilizes charged particles heavier than protons. Therefore, it is essential that additional radiobiological knowledge be obtained using state-of-the-art technologies and biological models and end points relevant to clinical outcome. Currently, most such ion radiotherapy-related research is being conducted outside the U.S. This article addresses the substantial contributions to that research that are possible at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL), which is the only facility in the U.S. at this time where heavy-ion radiobiology research with the ion species and energies of interest for therapy can be done. Here, we briefly discuss the relevant facilities at NSRL and how selected charged particle biology research gaps could be addressed using those facilities.

  14. Experimental investigation of the charge/discharge process for an organic PCM macroencapsulated in an aluminium rectangular cavity

    Science.gov (United States)

    Bejan, Andrei-Stelian; Labihi, Abdelouhab; Croitoru, Cristiana Verona; Catalina, Tiberiu; Chehouani, Hassan; Benhamou, Brahim

    2018-02-01

    Buildings sector has one of the highest potential regarding the reduction of greenhouse gases emissions, as being responsible for more than 40% of energy consumption worldwide. This is why, in order to achieve indoor thermal comfort, it is mandatory to use energy-efficient systems. Materials acting as thermal energy storage (TES) represents one of the most effective strategy that can be implemented and nowadays, many studies are focusing their attention on latent heat storage, respectively on phase changing materials (PCM) which can embed a large embed a high quantity of energy, unlike classic materials acting as thermal mass. This purpose of this paper is to experimentally investigate the charge and discharge processes for an organic PCM (RT35 paraffin) macroencapsulated in an aluminium rectangular cavity which was placed first in a horizontal position and after in a vertical position. After several experimental campaigns conducted we determined that the vertical position enhance the heat transfer because of the natural convection which occurs inside the cavity. Therefore, the charging time is lower in case of the vertical cavity and the temperature measured inside and on the surface is higher.

  15. Fluctuations of charge variance and interaction time for dissipative processes in 27 Al + 27 Al collision

    International Nuclear Information System (INIS)

    Berceanu, I.; Andronic, A.; Duma, M.

    1999-01-01

    The systematic studies of dissipative processes in light systems were completed with experiments dedicated to the measurement of the excitation functions in 19 F + 27 Al and 27 Al + 27 Al systems in order to obtain deeper insight on DNS configuration and its time evolution. The excitation function for 19 F + 27 Al system evidenced fluctuations larger than the statistical errors. Large Z and angular cross correlation coefficients supported their non-statistical nature. The energy dependence of second order observables, namely the second moment of the charge distribution and the product ω·τ (ω - the angular velocity of the DNS and τ its mean lifetime) extracted from the angular distributions were studied for 19 F + 27 Al case. In this contribution we are reporting the preliminary results of similar studies performed for 27 Al + 27 Al case. The variance of the charge distribution were obtained fitting the experimental charge distribution with a Gaussian centered on Z = 13 and the product ω·τ was extracted from the angular distributions. The results for 19 F + 27 Al case are confirmed by a preliminary analysis of the data for 27 Al + 27 Al system. The charge variance and ω·τ excitation functions for Z = 11 fragment are represented together with the excitation function of the cross section. One has to mention that the data for 27 Al + 27 Al system were not corrected for particle evaporation processes. The effect of the evaporation corrections on the excitation function was studied using a Monte Carlo simulation. The α particle evaporation was also included and the evaluation of the particle separation energies was made using experimental masses of the fragments. The excitation functions for 27 Al + 27 Al system for primary and secondary fragments were simulated. No structure due to particle evaporation was observed. The correlated fluctuations in σ Z and ω·τ excitation functions support a stochastic exchange of nucleons as the main mechanism for

  16. Absence of a space-charge-derived enhancement of ionic conductivity in β|γ- heterostructured 7H- and 9R-AgI

    International Nuclear Information System (INIS)

    Morgan, B J; Madden, P A

    2012-01-01

    Extreme room temperature conductivity enhancements have been reported for nanocrystalline AgI of up to × 10 4 relative to bulk β-AgI (Guo et al 2005 Adv. Mater. 17 2815-9). These samples were identified as possessing 7H and 9R polytype structures, which can be considered as heterostructures composed of thin, commensurate layers in the β (wurtzite) and γ (zincblende) phases. It has been proposed that space-charge layer formation at β|γ-interfaces causes near complete disordering of the Ag + sublattice in these polytypes, resulting in a massive intrinsic enhancement of ionic conductivity. We have performed molecular dynamics simulations of β- and γ-AgI and mixed β|γ superlattices, to study the effect of heterostructuring on intrinsic defect populations and Ag + transport. The ionic conductivities and Ag + diffusion coefficients vary as β > 7H ≈ 9R ≈ 10L > γ. The β|γ-heterostructured polytypes show no enhancement in defect populations or Ag + mobilities relative to the β-AgI phase, and instead behave as simple composites of β- and γ-AgI. This contradicts the proposal that the extreme conductivity enhancement observed for 7H and 9R polytypes is explained by extensive space-charge formation. (paper)

  17. Charge-Transfer Processes in Warm Dense Matter: Selective Spectral Filtering for Laser-Accelerated Ion Beams

    Science.gov (United States)

    Braenzel, J.; Barriga-Carrasco, M. D.; Morales, R.; Schnürer, M.

    2018-05-01

    We investigate, both experimentally and theoretically, how the spectral distribution of laser accelerated carbon ions can be filtered by charge exchange processes in a double foil target setup. Carbon ions at multiple charge states with an initially wide kinetic energy spectrum, from 0.1 to 18 MeV, were detected with a remarkably narrow spectral bandwidth after they had passed through an ultrathin and partially ionized foil. With our theoretical calculations, we demonstrate that this process is a consequence of the evolution of the carbon ion charge states in the second foil. We calculated the resulting spectral distribution separately for each ion species by solving the rate equations for electron loss and capture processes within a collisional radiative model. We determine how the efficiency of charge transfer processes can be manipulated by controlling the ionization degree of the transfer matter.

  18. 10 CFR 51.26 - Requirement to publish notice of intent and conduct scoping process.

    Science.gov (United States)

    2010-01-01

    ... publish notice of intent and conduct scoping process. (a) Whenever the appropriate NRC staff director... 10 Energy 2 2010-01-01 2010-01-01 false Requirement to publish notice of intent and conduct... action, a notice of intent will be prepared as provided in § 51.27, and will be published in the Federal...

  19. Research on Melt Degassing Processes of High Conductivity Hard Drawn Aluminum Wire

    Science.gov (United States)

    Xu, Xuexia; Feng, Yanting; Wang, Qing; Li, Wenbin; Fan, Hui; Wang, Yong; Li, Guowei; Zhang, Daoqian

    2018-03-01

    Degassing effects of ultrasonic and vacuum processes on high conductivity hard drawn aluminum melt were studied. Results showed that the degassing efficiency improved with the increase of ultrasonic power within certain range, stabilizing at 70% with 240W. For vacuum degassing process, hydrogen content of aluminum melt decreased with the loading time and was linear with logarithm of vacuum degree. Comparison of degassing effects of ultrasonic, vacuum, vacuum-ultrasonic degassing process showed that vacuum-ultrasonic process presented optimal effect.

  20. Fractional charges

    International Nuclear Information System (INIS)

    Saminadayar, L.

    2001-01-01

    20 years ago fractional charges were imagined to explain values of conductivity in some materials. Recent experiments have proved the existence of charges whose value is the third of the electron charge. This article presents the experimental facts that have led theorists to predict the existence of fractional charges from the motion of quasi-particles in a linear chain of poly-acetylene to the quantum Hall effect. According to the latest theories, fractional charges are neither bosons nor fermions but anyons, they are submitted to an exclusive principle that is less stringent than that for fermions. (A.C.)

  1. Ultrafast spin exchange-coupling torque via photo-excited charge-transfer processes

    Science.gov (United States)

    Ma, X.; Fang, F.; Li, Q.; Zhu, J.; Yang, Y.; Wu, Y. Z.; Zhao, H. B.; Lüpke, G.

    2015-10-01

    Optical control of spin is of central importance in the research of ultrafast spintronic devices utilizing spin dynamics at short time scales. Recently developed optical approaches such as ultrafast demagnetization, spin-transfer and spin-orbit torques open new pathways to manipulate spin through its interaction with photon, orbit, charge or phonon. However, these processes are limited by either the long thermal recovery time or the low-temperature requirement. Here we experimentally demonstrate ultrafast coherent spin precession via optical charge-transfer processes in the exchange-coupled Fe/CoO system at room temperature. The efficiency of spin precession excitation is significantly higher and the recovery time of the exchange-coupling torque is much shorter than for the demagnetization procedure, which is desirable for fast switching. The exchange coupling is a key issue in spin valves and tunnelling junctions, and hence our findings will help promote the development of exchange-coupled device concepts for ultrafast coherent spin manipulation.

  2. Bianthrone in a Single-Molecule Junction: Conductance Switching with a Bistable Molecule Facilitated by Image Charge Effects

    DEFF Research Database (Denmark)

    Bjørnholm, Thomas

    2010-01-01

    Bianthrone is a sterically hindered compound that exists in the form of two nonplanar isomers. Our experimental study of single-molecule junctions with bianthrone reveals persistent switching of electric conductance at low temperatures, which can be reasonably associated with molecular isomerizat...

  3. Stretchable V2O5/PEDOT supercapacitors: a modular fabrication process and charging with triboelectric nanogenerators.

    Science.gov (United States)

    Qi, Ruijie; Nie, Jinhui; Liu, Mingyang; Xia, Mengyang; Lu, Xianmao

    2018-04-26

    Stretchable energy storage devices are of great importance for the viable applications of wearable/stretchable electronics. Studies on stretchable energy storage devices, especially supercapacitors (SCs), have shown encouraging progress. However, challenges still remain in the pursuit of high specific capacitances and facile fabrication methods. Herein, we report a modular materials fabrication and assembly process for stretchable SCs. With a V2O5/PEDOT composite as the active material, the resulting stretchable SCs exhibited high areal specific capacitances up to 240 mF cm-2 and good capacitance retention at a strain of 50%. To demonstrate the facile assembly process, a stretchable wristband was fabricated by simply assembling SC cells in series to deliver a voltage higher than 2 V. Charging the wristband with a triboelectric nanogenerator (TENG) to light an LED was further demonstrated, indicating the potential to integrate our SCs with environmental energy harvesters for self-powered stretchable devices.

  4. The electrical conductivity of CuCrZr alloy after SPD processing

    International Nuclear Information System (INIS)

    Lipińska, M; Bazarnik, P; Lewandowska, M

    2014-01-01

    CuCrZr alloys exhibit very good relation between mechanical properties and electrical conductivity. However, for its use in some advanced applications improvement of mechanical strength while preserving high electrical conducting is required. Therefore, in this work a CuCrZr alloy was subjected to a series of thermo-mechanical treatments, including solution annealing and water quenching, SPD processing (using hydrostatic extrusion and ECAP) as well as aging in order to improve mechanical strength. The influence of these processing procedures on microstructure features and mechanical properties was determined by TEM observation and microhardness measurements, respectively. Electrical conductivity of the samples was measured by four-points method. The results have shown that it is possible to improve mechanical strength while preserving good electrical conductivity by a proper combination of SPD processing and heat treatment

  5. Self-organization process of a magnetohydrodynamic plasma in the presence of thermal conduction

    International Nuclear Information System (INIS)

    Zhu, Shao-ping; Horiuchi, Ritoku; Sato, Tetsuya; Watanabe, K.; Hayashi, T.; Todo, Y.; Watanabe, T.H.; Kageyama, A.; Takamaru, H.

    1995-12-01

    A self-organization process of a magnetohydrodynamic(MHD) plasma with a finite thermal conductivity is investigated by means of a three-dimensional MHD simulation. With no thermal conduction an MHD system self-organizes to a non-Taylor's state in which the electric current perpendicular to the magnetic field remains comparable to the parallel electric current. In the presence of thermal conductivity the perpendicular component of electric current and the nonuniformity of thermal pressure generated by driven reconnection tend to be smoothened. Thus, the self-organized state approaches to a force-free minimum energy state under the influence of thermal conduction. Detailed energy conversion processes are also studied to find that the rapid decay of magnetic energy during the self-organization process is caused not only through the ohmic heating, but also through the work done by the j x B force. (author)

  6. Composite material having high thermal conductivity and process for fabricating same

    Science.gov (United States)

    Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

    1998-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  7. Interface charge transfer process in ZnO:Mn/ZnS nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Stefan, M.; Toloman, D., E-mail: dana.toloman@itim-cj.ro; Popa, A. [National Institute for R & D of Isotopic and Molecular Technology (Romania); Mesaros, A. [Technical University of Cluj-Napoca, Superconductivity, Spintronics and Surface Science Center – C4S (Romania); Vasile, O. R. [University “Politehnica” from Bucharest, Faculty of Applied Chemistry and Material Science (Romania); Leostean, C.; Pana, O. [National Institute for R & D of Isotopic and Molecular Technology (Romania)

    2016-03-15

    ZnO:Mn/ZnS nanocomposites were prepared by seed-mediated growth of ZnS QDs onto the preformed ZnO:Mn nanoparticles. The formation of the nanocomposite structure has been evidenced by XRD, HRTEM, and XPS. The architecture of the nanocomposite with outer ZnS QDs around ZnO:Mn cores is sustained by the sulfur and oxygen depth profiles resulted from XPS. When the two components are brought together, the band gap of ZnS component decreases while that of ZnO:Mn increases. It is the result of interface charge transfer from ZnO:Mn to ZnS QDs. Here ZnO:Mn valence states are extended through the interface into unoccupied gap states of ZnS. The energy band setup is modified from a type II into a type I band alignment. The process is accompanied by enhancement of composite UV emission of PL spectra as compared to its counterparts. The charge transfer from valence band also determines the increase of the core-polarization effect of sshell electrons at Mn{sup 2+} nucleus, thus determining the increase of the hyperfine field through the reduction of the covalency degree of Zn(Mn)–O bonds. The quantum confinement in ZnS QDs promotes the ferromagnetic coupling of singly occupied states due to Zn vacancies determining a superparamagnetic behavior of the ensemble. When the nanocomposites are formed, due to interface charge transfer effects, an increased number of filled cation vacancies in ZnS QDs develop, thus disrupting the pre-existing ferromagnetic coupling between spins resulting in a significant reduction of the overall saturation magnetization. The possibility to modulate nanocomposite properties by controlling the interface interactions may be foreseen in these types of materials.

  8. Lithium-modulated conduction band edge shifts and charge-transfer dynamics in dye-sensitized solar cells based on a dicyanamide ionic liquid.

    Science.gov (United States)

    Bai, Yu; Zhang, Jing; Wang, Yinghui; Zhang, Min; Wang, Peng

    2011-04-19

    Lithium ions are known for their potent function in modulating the energy alignment at the oxide semiconductor/dye/electrolyte interface in dye-sensitized solar cells (DSCs), offering the opportunity to control the associated multichannel charge-transfer dynamics. Herein, by optimizing the lithium iodide content in 1-ethyl-3-methylimidazolium dicyanamide-based ionic liquid electrolytes, we present a solvent-free DSC displaying an impressive 8.4% efficiency at 100 mW cm(-2) AM1.5G conditions. We further scrutinize the origins of evident impacts of lithium ions upon current density-voltage characteristics as well as photocurrent action spectra of DSCs based thereon. It is found that, along with a gradual increase of the lithium content in ionic liquid electrolytes, a consecutive diminishment of the open-circuit photovoltage arises, primarily owing to a noticeable downward movement of the titania conduction band edge. The conduction band edge displacement away from vacuum also assists the formation of a more favorable energy offset at the titania/dye interface, and thereby leads to a faster electron injection rate and a higher exciton dissociation yield as implied by transient emission measurements. We also notice that the adverse influence of the titania conduction band edge downward shift arising from lithium addition upon photovoltage is partly compensated by a concomitant suppression of the triiodide involving interfacial charge recombination. © 2011 American Chemical Society

  9. Face Emotion Processing in Depressed Children and Adolescents with and without Comorbid Conduct Disorder

    Science.gov (United States)

    Schepman, Karen; Taylor, Eric; Collishaw, Stephan; Fombonne, Eric

    2012-01-01

    Studies of adults with depression point to characteristic neurocognitive deficits, including differences in processing facial expressions. Few studies have examined face processing in juvenile depression, or taken account of other comorbid disorders. Three groups were compared: depressed children and adolescents with conduct disorder (n = 23),…

  10. Conducting Qualitative Data Analysis: Qualitative Data Analysis as a Metaphoric Process

    Science.gov (United States)

    Chenail, Ronald J.

    2012-01-01

    In the second of a series of "how-to" essays on conducting qualitative data analysis, Ron Chenail argues the process can best be understood as a metaphoric process. From this orientation he suggests researchers follow Kenneth Burke's notion of metaphor and see qualitative data analysis as the analyst systematically considering the "this-ness" of…

  11. 77 FR 17460 - Multistakeholder Process To Develop Consumer Data Privacy Codes of Conduct

    Science.gov (United States)

    2012-03-26

    ..., 2012, NTIA requested public comments on (1) which consumer data privacy issues should be the focus of.... 120214135-2203-02] RIN 0660-XA27 Multistakeholder Process To Develop Consumer Data Privacy Codes of Conduct... request for public comments on the multistakeholder process to develop consumer data privacy codes of...

  12. Surface conductivity dependent dynamic behaviour of an ultrafine atmospheric pressure plasma jet for microscale surface processing

    Energy Technology Data Exchange (ETDEWEB)

    Abuzairi, Tomy [Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8561 (Japan); Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424 (Indonesia); Okada, Mitsuru [Department of Engineering, Shizuoka University, Hamamatsu 432-8561 (Japan); Bhattacharjee, Sudeep [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India); Nagatsu, Masaaki, E-mail: nagatsu.masaaki@shizuoka.ac.jp [Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8561 (Japan); Department of Engineering, Shizuoka University, Hamamatsu 432-8561 (Japan); Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8561 (Japan)

    2016-12-30

    Highlights: • Spatio-temporal behaviors of capillary APPJs are studied for various substrates. • Plasma irradiation area depended on the substrate conductivity and permittivity. • Surface irradiation area was significantly broadened in polymer-like substrate. • Effect of applying a substrate bias on the APPJ irradiation area was investigated. - Abstract: An experimental study on the dynamic behaviour of microcapillary atmospheric pressure plasma jets (APPJs) with 5 μm tip size for surfaces of different conductivity is reported. Electrical and spatio-temporal characteristics of the APPJs are monitored using high voltage probe, current monitor and high speed intensified charge couple device camera. From these experimental results, we presented a simple model to understand the electrical discharge characteristics of the capillary APPJs with double electrodes, and estimated the velocity of the ionization fronts in the jet and the electron density to be 3.5–4.2 km/s and 2–7 × 10{sup 17} m{sup −3}. By analyzing the dynamics of the microcapillary APPJs for different substrate materials, it was found that the surface irradiation area strongly depended on the substrate conductivity and permittivity, especially in the case of polymer-like substrate, surface irradiation area was significantly broadened probably due to the repelling behaviour of the plasma jets from the accumulated electrical charges on the polymer surface. The effect of applying a substrate bias in the range from −900 V to +900 V on the plasma irradiation onto the substrates was also investigated. From the knowledge of the present results, it is helpful for choosing the substrate materials for microscale surface modification.

  13. Surface conductivity dependent dynamic behaviour of an ultrafine atmospheric pressure plasma jet for microscale surface processing

    International Nuclear Information System (INIS)

    Abuzairi, Tomy; Okada, Mitsuru; Bhattacharjee, Sudeep; Nagatsu, Masaaki

    2016-01-01

    Highlights: • Spatio-temporal behaviors of capillary APPJs are studied for various substrates. • Plasma irradiation area depended on the substrate conductivity and permittivity. • Surface irradiation area was significantly broadened in polymer-like substrate. • Effect of applying a substrate bias on the APPJ irradiation area was investigated. - Abstract: An experimental study on the dynamic behaviour of microcapillary atmospheric pressure plasma jets (APPJs) with 5 μm tip size for surfaces of different conductivity is reported. Electrical and spatio-temporal characteristics of the APPJs are monitored using high voltage probe, current monitor and high speed intensified charge couple device camera. From these experimental results, we presented a simple model to understand the electrical discharge characteristics of the capillary APPJs with double electrodes, and estimated the velocity of the ionization fronts in the jet and the electron density to be 3.5–4.2 km/s and 2–7 × 10"1"7 m"−"3. By analyzing the dynamics of the microcapillary APPJs for different substrate materials, it was found that the surface irradiation area strongly depended on the substrate conductivity and permittivity, especially in the case of polymer-like substrate, surface irradiation area was significantly broadened probably due to the repelling behaviour of the plasma jets from the accumulated electrical charges on the polymer surface. The effect of applying a substrate bias in the range from −900 V to +900 V on the plasma irradiation onto the substrates was also investigated. From the knowledge of the present results, it is helpful for choosing the substrate materials for microscale surface modification.

  14. The rates of charge separation and energy destructive charge recombination processes within an organic dyad in presence of metal-semiconductor core shell nanocomposites.

    Science.gov (United States)

    Mandal, Gopa; Bhattacharya, Sudeshna; Das, Subrata; Ganguly, Tapan

    2012-01-01

    Steady state and time resolved spectroscopic measurements were made at the ambient temperature on an organic dyad, 1-(4-Chloro-phenyl)-3-(4-methoxy-naphthalen-1-yl)-propenone (MNCA), where the donor 1-methoxynaphthalene (1 MNT) is connected with the acceptor p-chloroacetophenone (PCA) by an unsaturated olefinic bond, in presence of Ag@TiO2 nanoparticles. Time resolved fluorescence and absorption measurements reveal that the rate parameters associated with charge separation, k(CS), within the dyad increases whereas charge recombination rate k(CR) reduces significantly when the surrounding medium is changed from only chloroform to mixture of chloroform and Ag@TiO2 (noble metal-semiconductor) nanocomposites. The observed results indicate that the dyad being combined with core-shell nanocomposites may form organic-inorganic nanocomposite system useful for developing light energy conversion devices. Use of metal-semiconductor nanoparticles may provide thus new ways to modulate charge recombination processes in light energy conversion devices. From comparison with the results obtained in our earlier investigations with only TiO2 nanoparticles, it is inferred that much improved version of light energy conversion device, where charge-separated species could be protected for longer period of time of the order of millisecond, could be designed by using metal-semiconductor core-shell nanocomposites rather than semiconductor nanoparticles only.

  15. Consequences of Early Conductive Hearing Loss on Long-Term Binaural Processing.

    Science.gov (United States)

    Graydon, Kelley; Rance, Gary; Dowell, Richard; Van Dun, Bram

    The aim of the study was to investigate the long-term effects of early conductive hearing loss on binaural processing in school-age children. One hundred and eighteen children participated in the study, 82 children with a documented history of conductive hearing loss associated with otitis media and 36 controls who had documented histories showing no evidence of otitis media or conductive hearing loss. All children were demonstrated to have normal-hearing acuity and middle ear function at the time of assessment. The Listening in Spatialized Noise Sentence (LiSN-S) task and the masking level difference (MLD) task were used as the two different measures of binaural interaction ability. Children with a history of conductive hearing loss performed significantly poorer than controls on all LiSN-S conditions relying on binaural cues (DV90, p = binaural cues. Fifteen children with a conductive hearing loss history (18%) showed results consistent with a spatial processing disorder. No significant difference was observed between the conductive hearing loss group and the controls on the MLD task. Furthermore, no correlations were found between LiSN-S and MLD. Results show a relationship between early conductive hearing loss and listening deficits that persist once hearing has returned to normal. Results also suggest that the two binaural interaction tasks (LiSN-S and MLD) may be measuring binaural processing at different levels. Findings highlight the need for a screening measure of functional listening ability in children with a history of early otitis media.

  16. Reply to "Comment on `Conductance scaling in Kondo-correlated quantum dots: Role of level asymmetry and charging energy'"

    Science.gov (United States)

    Merker, L.; Kirchner, S.; Muñoz, E.; Costi, T. A.

    2014-08-01

    The Comment of A. A. Aligia claims that the superperturbation theory (SPT) approach [E. Muñoz, C. J. Bolech, and S. Kirchner, Phys. Rev. Lett. 110, 016601 (2013), 10.1103/PhysRevLett.110.016601] formulated using dual fermions [A. N. Rubtsov, M. I. Katsnelson, and A. I. Lichtenstein, Phys. Rev. B 77, 033101 (2008), 10.1103/PhysRevB.77.033101] and used by us to compare with numerical renormalization group (NRG) results for the conductance [L. Merker, S. Kirchner, E. Muñoz, and T. A. Costi, Phys. Rev. B 87, 165132 (2013), 10.1103/PhysRevB.87.165132], fails to correctly extend the results of the symmetric Anderson impurity model (SIAM) for general values of the local level Ed in the Kondo regime. We answer this criticism. We also compare new NRG results for cB, with cB calculated directly from the low-field conductance, with new higher-order SPT calculations for this quantity, finding excellent agreement for all Ed and for U /πΔ extending into the strong coupling regime.

  17. Electron loss process and cross section of multiply charged ions by neutral atoms

    International Nuclear Information System (INIS)

    Karashima, S.; Watanabe, T.

    1985-01-01

    The significance of experimental and theoretical results on the electron loss and capture of ions in matter plays an important role in the charge equilibrium problems of fusion plasma physics and of accelerator physics. In the report, we calculate electron stripping cross section by using the binary encounter approximation (BEA). Our treatment of the electron loss process is based on BEA, in which the nucleus of B screened by the surrounding electrons collides with electrons in the ion A sup(q+). The basic approximation in EBA is that the ion interacts with only one electron or nucleus of the target atom at a time. In the calculation for Li sup(2+) + H, we have found that EBA will give approximately reliable results. (Mori, K.)

  18. Assembly and benign step-by-step post-treatment of oppositely charged reduced graphene oxides for transparent conductive thin films with multiple applications

    Science.gov (United States)

    Zhu, Jiayi; He, Junhui

    2012-05-01

    We report a new approach for the fabrication of flexible and transparent conducting thin films via the layer-by-layer (LbL) assembly of oppositely charged reduced graphene oxide (RGO) and the benign step-by-step post-treatment on substrates with a low glass-transition temperature, such as glass and poly(ethylene terephthalate) (PET). The RGO dispersions and films were characterized by means of atomic force microscopy, UV-visible absorption spectrophotometery, Raman spectroscopy, transmission electron microscopy, contact angle/interface systems and a four-point probe. It was found that the graphene thin films exhibited a significant increase in electrical conductivity after the step-by-step post-treatments. The graphene thin film on the PET substrate had a good conductivity retainability after multiple cycles (30 cycles) of excessively bending (bending angle: 180°), while tin-doped indium oxide (ITO) thin films on PET showed a significant decrease in electrical conductivity. In addition, the graphene thin film had a smooth surface with tunable wettability.We report a new approach for the fabrication of flexible and transparent conducting thin films via the layer-by-layer (LbL) assembly of oppositely charged reduced graphene oxide (RGO) and the benign step-by-step post-treatment on substrates with a low glass-transition temperature, such as glass and poly(ethylene terephthalate) (PET). The RGO dispersions and films were characterized by means of atomic force microscopy, UV-visible absorption spectrophotometery, Raman spectroscopy, transmission electron microscopy, contact angle/interface systems and a four-point probe. It was found that the graphene thin films exhibited a significant increase in electrical conductivity after the step-by-step post-treatments. The graphene thin film on the PET substrate had a good conductivity retainability after multiple cycles (30 cycles) of excessively bending (bending angle: 180°), while tin-doped indium oxide (ITO) thin films on

  19. Electrochemistry of end-capped oligothienyls. New insights into the polymerization mechanism and the charge storage, conduction and capacitive properties of polythiophene

    Energy Technology Data Exchange (ETDEWEB)

    Zotti, G. (Ist. di Polarografia ed Elettrochimica Preparativa, Consiglio Nazionale delle Ricerche, Padua (Italy)); Schiavon, G. (Ist. di Polarografia ed Elettrochimica Preparativa, Consiglio Nazionale delle Ricerche, Padua (Italy)); Berlin, A. (Dipt. di Chimica Organica e Industriale dell' Univ. e Centro CNR, Speciali Sistemi Organici, Milan (Italy)); Pagani, G. (Dipt. di Chimica Organica e Industriale dell' Univ. e Centro CNR, Speciali Sistemi Organici, Milan (Italy))

    1993-11-23

    The kinetics of anodic coupling to dimers of thiophene oligomers (n=3-5), methyl protected at one [alpha]-terminal position, is second order in oligomer concentration and evidences high activation enthalpies and negative activation entropies. Activation free energies are linearly related to the inverse of the oligomer length n (the dimerization rate decreases as n is increased). Thin films of methyl end-capped thiophene oligomers (n=4, 6, 8 and 10) display reversible oxidations from a single one-electron step (tetramer) to a single two-electron step (octamer and decamer) through two separate one-electron steps (hexamer). ESR indicates strong magnetic dimerization for the one-electron-oxidized hexamer. The close resemblance of the electrochemical and ESR behaviour of the hexamer with that of polythiophene suggests that oxidation of the latter occurs via hexameric spin-dimerized polarons. The conductive and capacitive properties of the end-capped oligomers (n=6, 8 and 10) were investigated by in situ conductivity and chronopotentiometry. While conductivity of octamer and decamer is displayed at the two-electron (bipolaron) state, the hexamer, insulating at this state, is conducting at the mixed-valence polaron-bipolaron state; capacitive responses are evidenced at the bipolaron state for the octamer and decamer only. The difference of conductive and capacitive behaviour between the hexamer and the higher oligomers is explained by charge localization in hexameric segments. (orig.)

  20. Contributions of conduction band offset to the enhanced separation efficiency of photoinduced charges for SrTiO3/Bi2O3 heterojunction semiconductor

    International Nuclear Information System (INIS)

    Zhang, Zhenlong; Zhu, Jichun; Li, Shengjun; Mao, Yanli

    2014-01-01

    SrTiO 3 /Bi 2 O 3 heterojunction semiconductor was prepared and characterized by X-ray diffraction, UV–vis absorption spectrum, and scanning electron microscope, surface photovoltage spectroscopy, and photoluminescence spectroscopy. The surface photovoltage spectra indicate that the separation efficiency of photoinduced charges for SrTiO 3 /Bi 2 O 3 was enhanced compared with that of SrTiO 3 or Bi 2 O 3 . The energy band diagram of SrTiO 3 /Bi 2 O 3 heterojunction was directly determined with X-ray photoelectron spectroscopy, and the conduction band offset between SrTiO 3 and Bi 2 O 3 was quantified to be 0.28±0.03 eV. The photoluminescence spectra display that the recombination rate of photoinduced carriers for SrTiO 3 /Bi 2 O 3 decreases compared with that of SrTiO 3 or Bi 2 O 3 , which is mainly due to the energy levels matching between them. Therefore the enhanced separation efficiency of photoinduced charges is resulting from the energy difference between the conduction band edges of SrTiO 3 and Bi 2 O 3 . -- Graphical abstract: Enhanced separation efficiency for SrTiO 3 /Bi 2 O 3 is resulting from the energy difference between the conduction band edges. Highlights: ●Heterojunction semiconductor of SrTiO 3 /Bi 2 O 3 was prepared. ●SrTiO 3 /Bi 2 O 3 presents enhanced separation efficiency. ●Conduction band offset between SrTiO 3 and Bi 2 O 3 is quantified. ●Recombination rate of SrTiO 3 /Bi 2 O 3 decreases compared with single phases

  1. CXSFIT Code Application to Process Charge-Exchange Recombination Spectroscopy Data at the T-10 Tokamak

    Science.gov (United States)

    Serov, S. V.; Tugarinov, S. N.; Klyuchnikov, L. A.; Krupin, V. A.; von Hellermann, M.

    2017-12-01

    The applicability of the CXSFIT code to process experimental data from Charge-eXchange Recombination Spectroscopy (CXRS) diagnostics at the T-10 tokamak is studied with a view to its further use for processing experimental data at the ITER facility. The design and operating principle of the CXRS diagnostics are described. The main methods for processing the CXRS spectra of the 5291-Å line of C5+ ions at the T-10 tokamak (with and without subtraction of parasitic emission from the edge plasma) are analyzed. The method of averaging the CXRS spectra over several shots, which is used at the T-10 tokamak to increase the signal-to-noise ratio, is described. The approximation of the spectrum by a set of Gaussian components is used to identify the active CXRS line in the measured spectrum. Using the CXSFIT code, the ion temperature in ohmic discharges and discharges with auxiliary electron cyclotron resonance heating (ECRH) at the T-10 tokamak is calculated from the CXRS spectra of the 5291-Å line. The time behavior of the ion temperature profile in different ohmic heating modes is studied. The temperature profile dependence on the ECRH power is measured, and the dynamics of ECR removal of carbon nuclei from the T-10 plasma is described. Experimental data from the CXRS diagnostics at T-10 substantially contribute to the implementation of physical programs of studies on heat and particle transport in tokamak plasmas and investigation of geodesic acoustic mode properties.

  2. Research on cylinder processes of gasoline homogenous charge compression ignition (HCCI) engine

    Science.gov (United States)

    Cofaru, Corneliu

    2017-10-01

    This paper is designed to develop a HCCI engine starting from a spark ignition engine platform. The engine test was a single cylinder, four strokes provided with carburetor. The results of experimental research on this version were used as a baseline for the next phase of the work. After that, the engine was modified for a HCCI configuration, the carburetor was replaced by a direct fuel injection system in order to control precisely the fuel mass per cycle taking into account the measured intake air-mass. To ensure that the air - fuel mixture auto ignite, the compression ratio was increased from 9.7 to 11.5. The combustion process in HCCI regime is governed by chemical kinetics of mixture of air-fuel, rein ducted or trapped exhaust gases and fresh charge. To modify the quantities of trapped burnt gases, the exchange gas system was changed from fixed timing to variable valve timing. To analyze the processes taking place in the HCCI engine and synthesizing a control system, a model of the system which takes into account the engine configuration and operational parameters are needed. The cylinder processes were simulated on virtual model. The experimental research works were focused on determining the parameters which control the combustion timing of HCCI engine to obtain the best energetic and ecologic parameters.

  3. Charging machine

    International Nuclear Information System (INIS)

    Medlin, J.B.

    1976-01-01

    A charging machine for loading fuel slugs into the process tubes of a nuclear reactor includes a tubular housing connected to the process tube, a charging trough connected to the other end of the tubular housing, a device for loading the charging trough with a group of fuel slugs, means for equalizing the coolant pressure in the charging trough with the pressure in the process tubes, means for pushing the group of fuel slugs into the process tube and a latch and a seal engaging the last object in the group of fuel slugs to prevent the fuel slugs from being ejected from the process tube when the pusher is removed and to prevent pressure liquid from entering the charging machine. 3 claims, 11 drawing figures

  4. Electrolytic process to produce sodium hypochlorite using sodium ion conductive ceramic membranes

    Science.gov (United States)

    Balagopal, Shekar; Malhotra, Vinod; Pendleton, Justin; Reid, Kathy Jo

    2012-09-18

    An electrochemical process for the production of sodium hypochlorite is disclosed. The process may potentially be used to produce sodium hypochlorite from seawater or low purity un-softened or NaCl-based salt solutions. The process utilizes a sodium ion conductive ceramic membrane, such as membranes based on NASICON-type materials, in an electrolytic cell. In the process, water is reduced at a cathode to form hydroxyl ions and hydrogen gas. Chloride ions from a sodium chloride solution are oxidized in the anolyte compartment to produce chlorine gas which reacts with water to produce hypochlorous and hydrochloric acid. Sodium ions are transported from the anolyte compartment to the catholyte compartment across the sodium ion conductive ceramic membrane. Sodium hydroxide is transported from the catholyte compartment to the anolyte compartment to produce sodium hypochlorite within the anolyte compartment.

  5. Effect of paraelectrode processes on contraction of space charge in periodic-pulse lasers

    Science.gov (United States)

    Arytyunyan, R. V.; Baranov, V. Yu.; Borisov, V. M.; Vinokhodov, A. Yu.; Kiryukhin, Yu. B.

    1986-05-01

    A characteristic feature of periodic-pulse electric-discharge CO2-lasers and excimer lasers is contraction of the space charge as the pulse repetition rate increases. The emission energy per pulse decreases as a consequence, with the average laser power first ceasing to increase linearly beyond a certain corner repetition rate and then decreasing beyond a certain critical repetition rate. A study of this phenomenon was made, for the purpose of separating the effect of paracathode processes from the effect of gas dynamics and then evaluating the effect of the former alone. Paraelectrode perturbations were simulated by focusing the radiation from the an XeCl-laser on the cathode surface in an atmosphere of nonabsorbing gases. Laser pulses of up to approximately 0.5 J energy and of approximately 50 ns duration were focused within a spot of 1 mm(2) area on a cathode inside a discharge chamber, with the power density of incident radiation regulated by means of an attenuator. A space charge within a volume of 2.5x4.5x9 cm(3) was generated between this specially shaped cathode and a mesh anode with an approximately 50% optical transmission coefficient. The space charge in helium and in neon was photographed, and the time lag of a discharge pulse behind a contracting laser pulse was measured as a function of the laser pulse energy for these two gases, as well as for a He+C12 gas mixture. The general trend was found to be the same in each case, the time lag increasing with increasing energy first at a slower rate up to a critical energy level and then faster. It has been established that plasma does not build up on the cathode before the laser pulse energy reaches 30 mJ (for a 3 mm(2) surface area), while plasma glow begins as the laser pulse energy reaches 150 mJ. A contracted channel begins to form within the laser-cathode interaction space, with an attendant fast increase of the time lag owing to evaporation of the cathode metal.

  6. Electric field distribution and the charge collection process in not-ideally compensated coaxial Ge(Li) detectors

    International Nuclear Information System (INIS)

    Szymczyk, W.M.; Moszynski, M.

    1978-01-01

    The not-ideally compensated space charge of donors and acceptors in lithium-drifted coaxial Ge(Li) detectors can modify the electric field distribution in the detector depleted volume, and influence in this way the charge collection process. Observations of the capacity, the time of charge collection (transit time), and the relative efficiency characteristics vs. detector bias voltage, showed that in conventional pin + coaaxial structures an undercompensation near the inner p-type core was typical. It was found that such an undercompensation had negligible consequences from the charge collection point of view. However, one case was observed where the modification near the outer electrode was present. In that case the charge pulses with remarkably increased rise-times were observed, as compared to the predictions based on the assumption of the classical, E proportional to 1/r, electric field distribution. The pulses expected from not-ideally compensated detectors were calculated using the Variable Velocity Approximation. The pulses expected from and much better agreement with the observed pulses was obtained. The calculated and observed dependencies of the charge transit times vs. reciprocal of the detector bias voltage exhibited, in the absence of the outer-electrode modification, linear parts. Measurement of their slopes permitted to find experimentally the depletion layer width provided the charge carriers mobility value was known, or vice versa. (Auth.)

  7. Four-phonon processes in the thermal conductivity of GaSb

    International Nuclear Information System (INIS)

    Aliev, M.I.; Arasly, D.G.; Guseinov, R.E.

    1978-01-01

    Phonon thermal conductivity of GaSb in the 300-700 K temperature range is studied by the light pulsed heating which is aimed at estimation of contributions of different polarized branches of acoustic oscillations into lattice thermal conductivity. The role of optico-acoustic interactions and multiphonon processes in phonon-phonon scattering at high temperatures is discussed. It is shown that the X thermal conductivity caused by the current carriers is negligibly small, and the Xsub(ph) phonon conductivity changes depending on temperature according to the Xsub(ph) approximately Tsup(-1.4) law. While calculating Xsub(ph) according to the Holland model taking into account phonon scattering on point defects the phonon thermal conductivity is given as a sum of contributions from longitudinal and transverse low-frequency Xsub(th1) and high-frequency Xsub(th2) acoustic phonons. It is established that at T>500 K Xsub(ph) is caused only by high-frequency transverse phonons and to explain the observed Xsub(ph) dependence on temperature it is necessary to introduce four-phonon process along with the three-phonon processes into intraphonon scattering

  8. Highly conductive p-type amorphous oxides from low-temperature solution processing

    International Nuclear Information System (INIS)

    Li Jinwang; Tokumitsu, Eisuke; Koyano, Mikio; Mitani, Tadaoki; Shimoda, Tatsuya

    2012-01-01

    We report solution-processed, highly conductive (resistivity 1.3-3.8 mΩ cm), p-type amorphous A-B-O (A = Bi, Pb; B = Ru, Ir), processable at temperatures (down to 240 °C) that are compatible with plastic substrates. The film surfaces are smooth on the atomic scale. Bi-Ru-O was analyzed in detail. A small optical bandgap (0.2 eV) with a valence band maximum (VBM) below but very close to the Fermi level (binding energy E VBM = 0.04 eV) explains the high conductivity and suggests that they are degenerated semiconductors. The conductivity changes from three-dimensional to two-dimensional with decreasing temperature across 25 K.

  9. Normal processes of phonon-phonon scattering and thermal conductivity of germanium crystals with isotopic disorder

    CERN Document Server

    Kuleev, I G

    2001-01-01

    The effect of normal processes of the phonon-phonon scattering on the thermal conductivity of the germanium crystals with various isotopic disorder degrees is considered. The phonon pulse redistribution in the normal scattering processes both inside each oscillatory branch (the Simons mechanism) and between various phonon oscillatory branches (the Herring mechanism) is accounted for. The contributions of the longitudinal and cross-sectional phonons drift motion into the thermal conductivity are analyzed. It is shown that the pulse redistribution in the Herring relaxation mechanism leads to essential suppression of the longitudinal phonons drift motion in the isotopically pure germanium crystals. The calculations results of thermal conductivity for the Herring relaxation mechanism agree well with experimental data on the germanium crystals with various isotopic disorder degrees

  10. 25 CFR 1000.175 - What is the process for conducting the negotiation phase?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false What is the process for conducting the negotiation phase? 1000.175 Section 1000.175 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ANNUAL FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT ACT AMENDMENTS TO THE INDIAN SELF-DETERMINATION AND EDUCATION ACT Negotiation...

  11. Relativistic thermodynamics of irreversible processes I. Heat conduction, diffusion, viscous flow and chemical reactions; formal part

    NARCIS (Netherlands)

    Kluitenberg, G.A.; Groot, S.R. de; Mazur, P.

    1953-01-01

    The relativistic thermodynamics of irreversible processes is developed for an isotropic mixture in which heat conduction, diffusion, viscous flow, chemical reactions and their cross-phenomena may occur. The four-vectors, representing the relative flows of matter, are defined in such a way that, in

  12. Fast Formation of Conductive Material by Simultaneous Chemical Process for Infilling Through-Silicon Via

    Science.gov (United States)

    Kawakita, Jin; Chikyow, Toyohiro

    2012-06-01

    It is necessary to develop a fast and inexpensive fabrication process of vertical electric wiring by through-silicon via (TSV) technology for advanced three-dimensional semiconductor devices. In this research, a fast-forming conductive composite was successfully developed by simultaneous deposition of conductive organic polymer (polypyrrole) and metal (silver) from the liquid phase, accelerated by photoirradiation. The growth rate of the composite was 38 nm·s-1, which is more than 10 times higher than that of copper by conventional plating. The electric conductivity of the composite was 2.1×104 Ω-1·cm-1, which is on the same level as general metal conductors. In addition, the effects of reaction conditions on the growth rate and the conductivity of the composites were revealed. From these results, the infilling time of the TSV was expected to shorten from the present 2-10 h to 5-10 m.

  13. Vibrational inelastic and charge transfer processes in H++H2 system: An ab initio study

    Science.gov (United States)

    Amaran, Saieswari; Kumar, Sanjay

    2007-12-01

    State-resolved differential cross sections, total and integral cross sections, average vibrational energy transfer, and the relative probabilities are computed for the H++H2 system using the newly obtained ab initio potential energy surfaces at the full CI/cc-pVQZ level of accuracy which allow for both the direct vibrational inelastic and the charge transfer processes. The quantum dynamics is treated within the vibrational close-coupling infinite-order-sudden approximation approach using the two ab initio quasidiabatic potential energy surfaces. The computed collision attributes for both the processes are compared with the available state-to-state scattering experiments at Ec.m.=20eV. The results are in overall good agreement with most of the observed scattering features such as rainbow positions, integral cross sections, and relative vibrational energy transfers. A comparison with the earlier theoretical study carried out on the semiempirical surfaces (diatomics in molecules) is also made to illustrate the reliability of the potential energy surfaces used in the present work.

  14. A new design approach for enhancement of DC/RF characteristics with improved ambipolar conduction of charge plasma TFET: proposal, and optimization

    Science.gov (United States)

    Aslam, Mohd.; Sharma, Dheeraj; Yadav, Shivendra; Soni, Deepak; Bajaj, Varun

    2018-04-01

    This article presents a new device structure to suppress ambipolarity with enhanced electrostatic characteristics of charge plasma TFET (CP-TFET). Here, implantation of a metal angle (MA) of low workfunction inside the high-k dielectric (HfO2) layer near source/channel interface gives excellent improvement in DC and RF characteristics of the proposed device. Deposition of MA is advantageous to increase abruptness of source/channel junction for reducing the tunneling barrier. Along with MA placement, the metal electrode, which is placed over the silicon wafer for inducing N+ drain region, is divided into the two parts of low and high workfunctions. The workfunction of the part of metal electrode near the channel region is taken comparatively higher than the other part to restrict the tunneling of holes at drain/channel junction under negative bias (-V_gs) condition. Such concept induces asymmetrical concentration of charge carriers in the drain region, which widens the tunneling barrier at the drain/channel interface. Consequently, the proposed device shows better RF performance along with suppressed ambipolar conduction. Furthermore, reliability of conventional and proposed structures has been tested in terms of linearity. Simultaneously, the effect of workfunction and length variation of MA on the device characteristics is analyzed in optimization section of the article.

  15. A nanogravimmetric investigation of the charging processes on ruthenium oxide thin films and their effect on methanol oxidation

    International Nuclear Information System (INIS)

    Santos, M.C.; Cogo, L.; Tanimoto, S.T.; Calegaro, M.L.; Bulhoes, L.O.S

    2006-01-01

    The charging processes and methanol oxidation that occur during the oxidation-reduction cycles in a ruthenium oxide thin film electrode (deposited by the sol-gel method on Pt covered quartz crystals) were investigated by using cyclic voltammetry, chronoamperometry and electrochemical quartz crystal nanobalance techniques. The ruthenium oxide rutile phase structure was determined by X-ray diffraction analysis. The results obtained during the charging of rutile ruthenium oxide films indicate that in the anodic sweep the transition from Ru(II) to Ru(VI) occurs followed by proton de-intercalation. In the cathodic sweep, electron injection occurs followed by proton intercalation, leading to Ru(II). The proton intercalation/de-intercalation processes can be inferred from the mass/charge relationship which gives a slope close to 1 g mol -1 (multiplied by the Faraday constant) corresponding to the molar mass of hydrogen. From the chronoamperometric measurements, charge and mass saturation of the RuO 2 thin films was observed (440 ng cm -2 ) during the charging processes, which is related to the total number of active sites in these films. Using the electrochemical quartz crystal nanobalance technique to study the methanol oxidation reaction at these films was possible to demonstrate that bulk oxidation occurs without the formation of strongly adsorbed intermediates such as CO ads , demonstrating that Pt electrodes modified by ruthenium oxide particles can be promising catalysts for the methanol oxidation as already shown in the literature

  16. An inspection to the hyperbolic heat conduction problem in processed meat

    Directory of Open Access Journals (Sweden)

    Liu Kuo-Chi

    2017-01-01

    Full Text Available This paper analyzes a hyperbolic heat conduction problem in processed meat with the non-homogenous initial temperature. This problem is related to an experimental study for the exploration of thermal wave behavior in biological tissue. Because the fundamental solution of the hyperbolic heat conduction model is difficult to be obtained, a modified numerical scheme is extended to solve the problem. The present results deviate from that in the literature and depict that the reliability of the experimentally measured properties presented in the literature is doubtful.

  17. Robotic extrusion processes for direct ink writing of 3D conductive polyaniline structures

    Science.gov (United States)

    Holness, F. Benjamin; Price, Aaron D.

    2016-04-01

    The intractable nature of intrinsically conductive polymers (ICP) leads to practical limitations in the fabrication of ICP-based transducers having complex three-dimensional geometries. Conventional ICP device fabrication processes have focused primarily on thin-film deposition techniques; therefore this study explores novel additive manufacturing processes specifically developed for ICP with the ultimate goal of increasing the functionality of ICP sensors and actuators. Herein we employ automated polymer paste extrusion processes for the direct ink writing of 3D conductive polyaniline (PANI) structures. Realization of these structures is enabled through a modified fused filament fabrication delta robot equipped with an integrated polymer paste extruder. This unique robot-controlled additive manufacturing platform is capable of fabricating high-resolution 3D conductive PANI and has been utilized to produce structures with a minimum feature size of 1.5 mm. The required processability of PANI is achieved by means of a counter-ion induced thermal doping method. Using this method, a viscous paste is formulated as the extrudate and a thermo-chemical treatment is applied post extrusion to finalize the complexation.

  18. Charge Transfer Processes in Collisions of Si4+ Ions with He Atoms at Intermediate Energies

    Science.gov (United States)

    Suzuki, R.; Watanabe, A.; Sato, H.; Gu, J. P.; Hirsch, G.; Buenker, R. J.; Kimura, M.; Stancil, P. C.

    Charge transfer in collisions of Si4+ ions with He atoms below 100 keV/u is studied by using a molecular orbital representation within both the semiclassical and quantal representations. Single transfer reaction Si4++He →Si3++He+ has been studied by a number of theoretical investigations. In addition to the reaction (1), the first semiclassical MOCC calculations are performed for the double transfer channel Si4++HE→Si2++He2+ Nine molecular states that connect both with single and double electron transfer processes are considered in the present model. Electronic states and corresponding couplings are determined by the multireference single- and double- excitation configuration interaction method. The present cross sections tie well with the earlier calculations of Stancil et al., Phys. Rev. A 55, 1064 (1997) at lower energies, but show a rather different magnitude from those of Bacchus-Montabonel and Ceyzeriat, Phys. Rev. A 58, 1162 (1998). The present rate constant is found to be significantly different from the experimental finding of Fang and Kwong, Phys. Rev. A 59, 342 (1996) at 4,600 K, and hence does not support the experiment.

  19. Charge transfer processes in hybrid solar cells composed of amorphous silicon and organic materials

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Sebastian; Neher, Dieter [Universitaet Potsdam, Inst. Physik u. Astronomie, Karl-Liebknecht-Strasse 24/25, 14467 Potsdam-Golm (Germany); Schulze, Tim; Korte, Lars [Helmholtz Zentrum Berlin, Inst. fuer Silizium Photovoltaik, Kekulestrasse 5, 12489 Berlin (Germany)

    2011-07-01

    The efficiency of hybrid solar cells composed of organic materials and amorphous hydrogenated silicon (a-Si:H) strongly depends upon the efficiency of charge transfer processes at the inorganic-organic interface. We investigated the performance of devices comprising an ITO/a-Si:H(n-type)/a-Si:H(intrinsic)/organic/metal multilayer structure and using two different organic components: zinc phthalocyanine (ZnPc) and poly(3-hexylthiophene) (P3HT). The results show higher power conversion- and quantum efficiencies for the P3HT based cells, compared to ZnPc. This can be explained by larger energy-level offset at the interface between the organic layer and a-Si:H, which facilitates hole transfer from occupied states in the valence band tail to the HOMO of the organic material and additionally promotes exciton splitting. The performance of the a-Si:H/P3HT cells can be further improved by treatment of the amorphous silicon surface with hydrofluoric acid (HF) and p-type doping of P3HT with F4TCNQ. The improved cells reached maximum power conversion efficiencies of 1%.

  20. Development of a Vibration-Based Electromagnetic Energy Harvester by a Conductive Direct-Write Process

    Directory of Open Access Journals (Sweden)

    Yao-Yun Feng

    2017-03-01

    Full Text Available A conductive direct-write process of multilayered coils for micro electromagnetic generators is proposed. This novel approach of using silver ink to form the conductive structures largely reduces the fabrication complexity, and it provides a faster alternative to the conventional semiconductor methods. Multi-layered coils with insulation were accurately layered on a micromachined cantilevered diaphragm by a dispenser. Coils several layers thick could be used to increase the power output and double coils were separated by a layer of insulation. Six prototypes, all capable of efficient conversion of vibrational energy into electrical energy, were fabricated. The experimental results, which include measurements of the electromotive force and power output, are presented. Prototypes with two coils and thicker conducting layers had less resistance and the power output was much more than that of a single-coil unit. This generator can produce 82 nW of power at a resonance frequency of 275 Hz under 5 g excitation.

  1. Preparation of flexible and heat-resisting conductive transparent film by the pyrosol process

    International Nuclear Information System (INIS)

    Usami, Hisanao; Nakasa, Akihiko; Adachi, Mami; Suzuki, Eiji; Fujimatsu, Hitoshi; Ohashi, Tatsuya; Yamada, Shigeo; Tsugita, Kouhei; Taniguchi, Yoshio

    2006-01-01

    A pyrosol process was successfully applied for the preparation of a flexible, conductive, and transparent inorganic film, a tin-doped indium oxide (ITO) film lined with a thin mica layer. This flexible heat-resistant ITO-mica film exhibited high conductivity and transparency, comparable to ITO deposited on glass substrate. The minimum radius of bending for the film, without any recognizable change in the conductivity and appearance, was 8 mm. The ITO deposited on mica showed a large (222) diffraction peak with a smaller (400) peak, in contrast to ITO deposited with (400) orientation on an ordinary glass substrate. Using the ITO-mica film, a prototype model of a flexible organic light emitting diode was fabricated

  2. Conductivity enhancement of surface-polymerized polyaniline films via control of processing conditions

    Science.gov (United States)

    Park, Chung Hyoi; Jang, Sung Kyu; Kim, Felix Sunjoo

    2018-01-01

    We investigate a fast and facile approach for the simultaneous synthesis and coating of conducting polyaniline (PANI) onto a substrate and the effects of processing conditions on the electrical properties of the fabricated films. Simultaneous polymerizing and depositing on the substrate forms a thin film with the average thickness of 300 nm and sheet resistance of 304 Ω/sq. Deposition conditions such as polymerization time (3-240 min), temperature (-10 to 40 °C), concentrations of monomer and oxidant (0.1-0.9 M), and type of washing solvents (acetone, water, and/or HCl solution) affect the film thickness, doping state, absorption characteristics, and solid-state nanoscale morphology, therefore affecting the electrical conductivity. Among the conditions, the surface-polymerized PANI film deposited at room temperature with acetone washing showed the highest conductivity of 22.2 S/cm.

  3. Tribo-charging properties of waste plastic granules in process of tribo-electrostatic separation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jia, E-mail: weee@sjtu.edu.cn; Wu, Guiqing; Xu, Zhenming

    2015-01-15

    Highlights: • The cyclone charging was more effective and stable than vibrating charging. • The small particle size was better changed than large ones and was more suitable recycled by TES. • The drying pretreatment is good for improving the short-term charging effect. - Abstract: Plastic products can be found everywhere in people’s daily life. With the consistent growth of plastic consumption, more and more plastic waste is generated. Considering the stable chemical and physics characteristics of plastic, regular waste management methods are not suitable for recycling economic strategy of each government, which has become a serious environmental problem. Recycling plastic waste is considered to be the best way to treat it, because it cannot only deduce the waste but also save the energy to produce new virgin plastic. Tribo-electrostatic separation is strongly recommended for plastic separation as it can preserve the original properties of plastic and has little additional pollution. In this study, plastic granules are generated by crushing plastic waste in waste electric and electronic equipment. The tribo-charging properties of plastic waste were studied by vibrating tribo-charging and cyclone tribo-charging. The triboelectric series obtained by vibrating was: (−)-PE–PS–PC–PVC–ABS–PP-(+), while the triboelectric series obtained by cyclone was (−)-PE–PS–PC–PVC–ABS–PP-(+). Further, the cyclone charging was more effective and stable than vibrating charging. The impact factors experiments showed that small particle size was better changed than large ones and were more suitable recycled by tribo-electrostatic separation. High relative humidity was identified as impede charging effect. The results of this study will help defining the operating parameters of subsequent separator.

  4. Tribo-charging properties of waste plastic granules in process of tribo-electrostatic separation

    International Nuclear Information System (INIS)

    Li, Jia; Wu, Guiqing; Xu, Zhenming

    2015-01-01

    Highlights: • The cyclone charging was more effective and stable than vibrating charging. • The small particle size was better changed than large ones and was more suitable recycled by TES. • The drying pretreatment is good for improving the short-term charging effect. - Abstract: Plastic products can be found everywhere in people’s daily life. With the consistent growth of plastic consumption, more and more plastic waste is generated. Considering the stable chemical and physics characteristics of plastic, regular waste management methods are not suitable for recycling economic strategy of each government, which has become a serious environmental problem. Recycling plastic waste is considered to be the best way to treat it, because it cannot only deduce the waste but also save the energy to produce new virgin plastic. Tribo-electrostatic separation is strongly recommended for plastic separation as it can preserve the original properties of plastic and has little additional pollution. In this study, plastic granules are generated by crushing plastic waste in waste electric and electronic equipment. The tribo-charging properties of plastic waste were studied by vibrating tribo-charging and cyclone tribo-charging. The triboelectric series obtained by vibrating was: (−)-PE–PS–PC–PVC–ABS–PP-(+), while the triboelectric series obtained by cyclone was (−)-PE–PS–PC–PVC–ABS–PP-(+). Further, the cyclone charging was more effective and stable than vibrating charging. The impact factors experiments showed that small particle size was better changed than large ones and were more suitable recycled by tribo-electrostatic separation. High relative humidity was identified as impede charging effect. The results of this study will help defining the operating parameters of subsequent separator

  5. A comparative theoretical study of exciton-dissociation and charge-recombination processes in oligothiophene/fullerene and oligothiophene/perylenediimide complexes for organic solar cells

    KAUST Repository

    Yi, Yuanping; Coropceanu, Veaceslav; Bré das, Jean-Luc

    2011-01-01

    ) is faster than that in the fullerene-based devices and (ii) in most cases, can compete with the dissociation of the charge-transfer state into mobile charge carriers. This faster charge-recombination process is consistent with the lower performance observed

  6. ZnO-Based Transparent Conductive Thin Films: Doping, Performance, and Processing

    International Nuclear Information System (INIS)

    Liu, Y.; Li, Y.; Zeng, H.

    2013-01-01

    ZnO-based transparent conductive thin films have attracted much attention as a promising substitute material to the currently used indium-tin-oxide thin films in transparent electrode applications. However, the detailed function of the dopants, acting on the electrical and optical properties of ZnO-based transparent conductive thin films, is not clear yet, which has limited the development and practical applications of ZnO transparent conductive thin films. Growth conditions such as substrate type, growth temperature, and ambient atmosphere all play important roles in structural, electrical, and optical properties of films. This paper takes a panoramic view on properties of ZnO thin films and reviews the very recent works on new, efficient, low-temperature, and high-speed deposition technologies. In addition, we highlighted the methods of producing ZnO-based transparent conductive film on flexible substrate, one of the most promising and rapidly emerging research areas. As optimum-processing-parameter conditions are being obtained and their influencing mechanism is becoming clear, we can see that there will be a promising future for ZnO-based transparent conductive films.

  7. Processing of Cu-Cr alloy for combined high strength and high conductivity

    Directory of Open Access Journals (Sweden)

    A.O Olofinjanaa

    2017-11-01

    Full Text Available High strength and high conductivity (HSHC are two intrinsic properties difficult to combine in metallic alloy design because; almost all strengthening mechanisms also lead to reduced conductivity. Precipitation hardening by nano-sized precipitates had proven to be the most adequate way to achieve the optimum combination of strength and conductivity in copper based alloys. However, established precipitation strengthened Cu- alloys are limited to very dilute concentration of solutes thereby limiting the volume proportion hardening precipitates. In this work, we report the investigation of the reprocessing of higher Cr concentration Cu- based alloys via rapid solidification. It is found that the rapid solidification in the as-cast ribbon imposed combined solution extension and ultra-refinement of Cr rich phases. X-ray diffraction evidences suggest that the solid solution extension was up to 6wt%Cr. Lattice parameters determined confirmed the many folds extension of solid solution of Cr in Cu.  Thermal aging studies of the cast ribbons indicated that peak aging treatments occurred in about twenty minutes. Peak aged hardness ranged from about 200 to well over 300Hv. The maximum peak aged hardness of 380Hv was obtained for alloy containing 6wt.%Cr but with conductivity of about 50%IACS. The best combined strength/conductivity was obtained for 4wt.%Cr  alloy with hardness of 350HV and conductivity of 80% IACS. The high strengths observed are attributed to the increased volume proportion of semi-coherent Cr rich nano-sized precipitates that evolved from the supersaturated solid solution of Cu-Cr that was achieved from the high cooling rates imposed by the ribbon casting process. The rapid overaging of the high Cr concentration Cu-Cr alloy is still a cause for concern in optimising the process for reaching peak HSHC properties. It is still important to investigate a microstructural design to slow or severely restrict the overaging process. The optimum

  8. Experimental investigations of single-electron detachment processes from H- ions colliding with MeV/u, highly charged ions

    International Nuclear Information System (INIS)

    Tawara, H.; Tonuma, T.; Kumagai, H.; Imai, T.; Uskov, D.B.; Presnyakov, L.P.

    1999-01-01

    Single electron detachment processes from negative hydrogen ions under collisions with MeV/u highly charged ions have been investigated using the so-called crossed-beams technique. The preliminary results of the single-electron detachment cross sections obtained is found to be in crude agreement with some empirical and theoretical estimations. (orig.)

  9. Dye-Sensitized Molecular Charge Transfer Complexes: Magnetic and Conduction Properties in the Photoexcited States of Ni(dmit2 Salts Containing Photosensitive Dyes

    Directory of Open Access Journals (Sweden)

    Ryoma Yamamoto

    2017-05-01

    Full Text Available Photosensitive dyes often induce charge transfer (CT between adjacent chemical species and themselves under irradiation of appropriate wavelengths. Because of the reversibility and selectivity of such CT, it is considered to be interesting to utilize such dyes as optically controllable trigger components for conduction and magnetism in the photoexcited states of organic materials. Based on this idea, such a type of new salts, i.e., γ- and δ-DiCC[Ni(dmit2] in addition to DiCC2[Ni(dmit2]3 have been prepared, characterized and their physical and structural properties have been examined both under dark and irradiated conditions (dmit2− = 1,3-dithiole-2-thione-4,5-dithiolate, DiCC+ = 3,3′-Dihexyloxacarbocyanine monocation. Among them, under UV (254–450 nm irradiation, δ-DiCC[Ni(dmit2] exhibited photoconductivity being six times as high as its dark conductivity at room temperature. The electron spin resonance (ESR spectra have demonstrated that there are photoexcited spins on both DiCC and [Ni(dmit2] species as a result of the CT transition between them, serving as localized spins (DiCC and carriers ([Ni(dmit2], respectively. The results obtained in this work have indicated that the strategy mentioned above is effective in developing organic photoresponsive semiconductors with paramagnetism.

  10. Electrical conductivity of In2O3 and Ga2O3 after low temperature ion irradiation; implications for instrinsic defect formation and charge neutrality level.

    Science.gov (United States)

    Vines, L; Bhoodoo, C; von Wenckstern, H; Grundmann, M

    2017-12-13

    The evolution of sheet resistance of n-type In 2 O 3 and Ga 2 O 3 exposed to bombardment with MeV 12 C and 28 Si ions at 35 K is studied in situ. While the sheet resistance of Ga 2 O 3 increased by more than eight orders of magnitude as a result of ion irradiation, In 2 O 3 showed a more complex defect evolution and became more conductive when irradiated at the highest doses. Heating up to room temperature reduced the sheet resistivity somewhat, but Ga 2 O 3 remained highly resistive, while In 2 O 3 showed a lower resistance than as deposited samples. Thermal admittance spectroscopy and deep level transient spectroscopy did not reveal new defect levels for irradiation up to [Formula: see text] cm -2 . A model where larger defect complexes preferentially produce donor like defects in In 2 O 3 is proposed, and may reveal a microscopic view of a charge neutrality level within the conduction band, as previously proposed.

  11. Electrical conductivity of In2O3 and Ga2O3 after low temperature ion irradiation; implications for instrinsic defect formation and charge neutrality level

    Science.gov (United States)

    Vines, L.; Bhoodoo, C.; von Wenckstern, H.; Grundmann, M.

    2018-01-01

    The evolution of sheet resistance of n-type In2O3 and Ga2O3 exposed to bombardment with MeV 12C and 28Si ions at 35 K is studied in situ. While the sheet resistance of Ga2O3 increased by more than eight orders of magnitude as a result of ion irradiation, In2O3 showed a more complex defect evolution and became more conductive when irradiated at the highest doses. Heating up to room temperature reduced the sheet resistivity somewhat, but Ga2O3 remained highly resistive, while In2O3 showed a lower resistance than as deposited samples. Thermal admittance spectroscopy and deep level transient spectroscopy did not reveal new defect levels for irradiation up to 2 × 1012 cm-2. A model where larger defect complexes preferentially produce donor like defects in In2O3 is proposed, and may reveal a microscopic view of a charge neutrality level within the conduction band, as previously proposed.

  12. Film processing characteristics of nano gold suitable for conductive application on flexible substrates

    International Nuclear Information System (INIS)

    Gupta, Ashish; Mandal, Saumen; Katiyar, Monica; Mohapatra, Yashowanta N.

    2012-01-01

    In spite of large number of studies and wide use of thiol encapsulated gold nanoparticles, the mechanism of their transformation to thin gold films for conductive applications is not as yet well understood. In order to understand and optimize the process of conversion of nanoparticle based ink for printing on plastic substrates, we synthesize and study thiolated Au nanoparticles, with average size of 2 nm, but with differing carbon chain length viz. butane (Au-C4), hexane (Au-C6) and octane (Au-C8). The link between the properties of Au nanoparticle and its transformation from nonconductive gold nanoparticle ink to conductive gold film is studied using a variety of techniques such as thermo gravimetric analysis (TGA), X-ray diffraction (XRD), atomic force microscopy, scanning electron microscopy and electrical conductivity measurements. A combined study of the shape of solution TGA and differential thermal analysis indicates occurrence of two distinct processes corresponding to disentanglement and debonding of thiol chains preceding the sintering of nanoparticles. The lowest sintering temperature is observed to be approximately 155 °C for chain length C4, and hence Au-C4 on polyethylene terephthalate substrates is studied in detail. Though XRD peaks of thick drop-cast films on polyethylene terephthalate substrate show increasing peak intensity with annealing temperature as expected, for spin coated thin films, in contrast, the peak intensity decreases with increase in annealing temperature. Electrical conductivity of the thin films is comparable to bulk gold after conversion, but decreases with increase in annealing temperature demonstrating the usefulness of insights obtained in the study for optimization of annealing schedules. - Highlights: ► Sintering of alkanethiol capped Au nanoparticles is chainlength dependent. ► Sintering temperature depends on thiol debonding. ► Butanethiol capped Au nanoparticles are the most suitable for flexible substrates.

  13. Synthesis, extrusion processing and ionic conductivity measurements of sodium β-alumina tubes

    Directory of Open Access Journals (Sweden)

    Karanja Avinash

    2015-09-01

    Full Text Available Pure and Li-doped sodium β-alumina (NaMg0.67Al10.33O17 ceramics were prepared from the stoichiometric mixture of raw powders. Pellets and tubes were formed from the precursor (NBA-1S and preformed sodium β-alumina powder through compaction and extrusion processing, respectively. The obtained specimens were finally sintered to dense ceramics. The ceramics were comparatively evaluated for their density, microstructure, phase formation and electrical properties. Both tubes and pellets processed with the preformed sodium β-alumina powder (NBA-2S showed enhanced densification along with relatively better phase purity and crystallinity. The ceramics prepared from the preformed powder exhibited higher density of 94–95% TD (theoretical densities in comparison to the ceramics processed from the raw mixture (NBA-1S with a density of 85–87% TD, which are complemented well through fractographs and microstructures. The ceramics processed using the preformed sodium β-alumina (NBA-2S also exhibited high room temperature AC conductivity of 1.77×10-4 S/cm (1 MHz with an increasing trend with temperature. The higher ionic conductivity at all temperatures in NBA-2S than in NBA-1S ceramics can be attributed to the relatively high phase purity, crystallinity and higher density values of NBA-2S ceramics.

  14. Effect of substrate bias on deposition behaviour of charged silicon nanoparticles in ICP-CVD process

    International Nuclear Information System (INIS)

    Yoo, Seung-Wan; Kim, Jung-Hyung; Seong, Dae-Jin; You, Shin-Jae; Seo, Byong-Hoon; Hwang, Nong-Moon

    2017-01-01

    The effect of a substrate bias on the deposition behaviour of crystalline silicon films during inductively coupled plasma chemical vapour deposition (ICP-CVD) was analysed by consideration of non-classical crystallization, in which the building block is a nanoparticle rather than an individual atom or molecule. The coexistence of positively and negatively charged nanoparticles in the plasma and their role in Si film deposition are confirmed by applying bias voltages to the substrate, which is sufficiently small as not to affect the plasma potential. The sizes of positively and negatively charged nanoparticles captured on a carbon membrane and imaged using TEM are, respectively, 2.7–5.5 nm and 6–13 nm. The film deposited by positively charged nanoparticles has a typical columnar structure. In contrast, the film deposited by negatively charged nanoparticles has a structure like a powdery compact with the deposition rate about three times higher than that for positively charged nanoparticles. All the films exhibit crystallinity even though the substrate is at room temperature, which is attributed to the deposition of crystalline nanoparticles formed in the plasma. The film deposited by negatively charged nanoparticles has the highest crystalline fraction of 0.84. (paper)

  15. Tribo-charging properties of waste plastic granules in process of tribo-electrostatic separation.

    Science.gov (United States)

    Li, Jia; Wu, Guiqing; Xu, Zhenming

    2015-01-01

    Plastic products can be found everywhere in people's daily life. With the consistent growth of plastic consumption, more and more plastic waste is generated. Considering the stable chemical and physics characteristics of plastic, regular waste management methods are not suitable for recycling economic strategy of each government, which has become a serious environmental problem. Recycling plastic waste is considered to be the best way to treat it, because it cannot only deduce the waste but also save the energy to produce new virgin plastic. Tribo-electrostatic separation is strongly recommended for plastic separation as it can preserve the original properties of plastic and has little additional pollution. In this study, plastic granules are generated by crushing plastic waste in waste electric and electronic equipment. The tribo-charging properties of plastic waste were studied by vibrating tribo-charging and cyclone tribo-charging. The triboelectric series obtained by vibrating was: (-)-PE-PS-PC-PVC-ABS-PP-(+), while the triboelectric series obtained by cyclone was (-)-PE-PS-PC-PVC-ABS-PP-(+). Further, the cyclone charging was more effective and stable than vibrating charging. The impact factors experiments showed that small particle size was better changed than large ones and were more suitable recycled by tribo-electrostatic separation. High relative humidity was identified as impede charging effect. The results of this study will help defining the operating parameters of subsequent separator. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Gas-surface dynamics and charging effects during plasma processing of semiconductors

    Science.gov (United States)

    Hwang, Gyeong Soon

    This thesis work attempts to elucidate the fundamentals of gas-surface interactions that occur during plasma etching. Controlled experiments using hyperthermal fluorine beams have enabled us to uncover the scattering dynamics at complex surfaces similar to those encountered in etching. By analyzing energy and angular distributions of inelastically scattered F atoms, we were able to distinguish single- and multiple-bounce scattering and to develop models to describe these exit channels. Furthermore, we found that hard-sphere collision kinematics can capture well the energy transfer of the hyperthermal F atoms onto fluorinated silicon surfaces. Based on the fundamental scattering information, we have developed a kinetic model that is described by two parameters: (1) direct inelastic scattering probability and (2) sticking (reaction) probability. These parameters are formulated as a function of the incident energy and angle of F atoms. By incorporating the empirical kinetic model into Monte Carlo based profile evolution simulations, we have unraveled the origin of many etch profile peculiarities which appear during hyperthermal F-beam etching, such as microtrenching, inverse microloading, and undercutting. The kinetic model has been used to describe successfully etching in Cl2-plasmas. For the study of pattern-dependent charging, we have developed a numerical model that combines plasma, sheath, and charging dynamics. The charging simulations illustrate that the directionality difference between ions and electrons arriving at the wafer, brought about by the sheath, causes differential charging on patterned areas even when the plasma is uniform. Using the newly developed charging model, we have investigated gate oxide damage. The results show that a potential drop across the thin gate oxide caused by differential microstructure charging is primarily responsible for gate oxide degradation by driving Fowler-Nordheim stress currents. In general, increasing the flux of low

  17. FMEA and FTA Analyses of the Adhesive Joining Process using Electrically Conductive Adhesives

    Directory of Open Access Journals (Sweden)

    E. Povolotskaya

    2012-01-01

    Full Text Available This paper introduces a formulation of appropriate risk estimation methods that can be used for improving of processes in the electronics area. Two risk assessment methods have been chosen with regard to the specifics of adhesive joining based on electrically conductive adhesives. The paper provides a combination of a failure mode and effect analysis (FMEA and fault tree analysis (FTA for optimizing of the joining process. Typical features and failures of the process are identified. Critical operations are found and actions for avoiding failures in these actions are proposed. A fault treehas been applied to the process in order to get more precise information about the steps and operations in the process, and the relations between these operations. The fault tree identifies potential failures of the process. Then the effects of the failures have been estimated by the failure mode and effect analysis method. All major differences between failure mode and effect analysis and fault tree analysis are defined and there is a discussion about how to use the two techniquescomplement each other and achieve more efficient results.

  18. Nano silver diffusion behaviour on conductive polymer during doping process for high voltage application

    Science.gov (United States)

    Mohammad, A.; Mahmood, A.; Chin, K. T.; Danquah, M. K.; van Stratan, S.

    2017-06-01

    Conductive polymer had opened a new era of engineering for microelectronics and semiconductor applications. However, it is still a challenge for high voltage applications due to lower electrical conductivity compare to metals. This results tremendous energy losses during transmission and restricts its usage. In order to address such problem a novel method was investigated using nano silver particle doped iodothiophene since silver is the highest electrical conductive material. The experiments were carried out to study the organometallic diffusion behaviour of nanosilver doped iodothiophene with different concentration of iodothiophene. Five different mixing ratio between nanosilver and the solution of iodothiophene dissolved in diethyl ether were used which are 1:1.25, 1:1.5, 1:2.5, 1:3 and l:5. It was revealed that there is an effective threshold concentration of which the nano silver evenly distributed and there was no coagulation observed. These parameters laid the foundation of better doping process between the nano silver and the polymer significantly which would contribute developing conductive polymer towards high voltage application for industries that are vulnerable to corrosive environment.

  19. CoPc and CoPcF16 on gold: Site-specific charge-transfer processes

    Directory of Open Access Journals (Sweden)

    Fotini Petraki

    2014-04-01

    Full Text Available Interface properties of cobalt(II phthalocyanine (CoPc and cobalt(II hexadecafluoro-phthalocyanine (CoPcF16 to gold are investigated by photo-excited electron spectroscopies (X-ray photoemission spectroscopy (XPS, ultraviolet photoemission spectroscopy (UPS and X-ray excited Auger electron spectroscopy (XAES. It is shown that a bidirectional charge transfer determines the interface energetics for CoPc and CoPcF16 on Au. Combined XPS and XAES measurements allow for the separation of chemical shifts based on different local charges at the considered atom caused by polarization effects. This facilitates a detailed discussion of energetic shifts of core level spectra. The data allow the discussion of site-specific charge-transfer processes.

  20. Autonomic markers of emotional processing: skin sympathetic nerve activity in humans during exposure to emotionally charged images.

    Science.gov (United States)

    Brown, Rachael; James, Cheree; Henderson, Luke A; Macefield, Vaughan G

    2012-01-01

    The sympathetic innervation of the skin primarily subserves thermoregulation, but the system has also been commandeered as a means of expressing emotion. While it is known that the level of skin sympathetic nerve activity (SSNA) is affected by anxiety, the majority of emotional studies have utilized the galvanic skin response as a means of inferring increases in SSNA. The purpose of the present study was to characterize the changes in SSNA when showing subjects neutral or emotionally charged images from the International Affective Picture System (IAPS). SSNA was recorded via tungsten microelectrodes inserted into cutaneous fascicles of the common peroneal nerve in ten subjects. Neutral images, positively charged images (erotica) or negatively charged images (mutilation) were presented in blocks of fifteen images of a specific type, each block lasting 2 min. Images of erotica or mutilation were presented in a quasi-random fashion, each block following a block of neutral images. Both images of erotica or images of mutilation caused significant increases in SSNA, but the increases in SSNA were greater for mutilation. The increases in SSNA were often coupled with sweat release and cutaneous vasoconstriction; however, these markers were not always consistent with the SSNA increases. We conclude that SSNA, comprising cutaneous vasoconstrictor and sudomotor activity, increases with both positively charged and negatively charged emotional images. Measurement of SSNA provides a more comprehensive assessment of sympathetic outflow to the skin than does the use of sweat release alone as a marker of emotional processing.

  1. Study of test-mass charging process in the LISA missions due to diffuse γ-rays

    International Nuclear Information System (INIS)

    Finetti, N; Scrimaglio, R; Grimani, C; Fabi, M

    2009-01-01

    Gravitational inertial sensors will be placed on board the Laser Interferometer Space Antenna (LISA) and aboard its precursor mission LISA Pathfinder (LISA-PF) in order to detect low frequency gravitational waves in space. Free-floating test-masses (Au 7 Pt 3 cubes) will be housed in inertial sensors for detecting possible laser signal variations induced by gravitational waves. Charging of the LISA test-masses due to exposure of the spacecraft to cosmic radiation and energetic solar particles will affect operation of gravitational inertial sensors. In this paper we report on the role of diffuse γ-rays in charging the LISA and LISA-PF test-masses with respect to protons and helium nuclei. The diffuse γ-ray flux in the Galaxy has been interpolated taking into account the outcomes of recent calculations. A comparison with γ-ray observations gathered by different experiments (COMPTEL and EGRET, Milagro, Whipple, HEGRA, TIBET) has been carried out. Simulations of the test-mass charging process have been performed by means of the FLUKA2006.3b package. Monte Carlo simulations of the interaction of cosmic particles with the LISA spacecraft indicate that the diffuse γ-ray contribution to the average steady-state test-mass charging rate and to the single-sided power spectrum of the charge rate noise is marginal with respect to that due to galactic cosmic-rays.

  2. Density effects in heavy ion charge-exchange processes in gaseous and solid targets

    International Nuclear Information System (INIS)

    Teplova, Ya.A.; Dmitriev, I.S.; Belkova, Yu.A.

    2000-01-01

    Experimental results on the pre-equilibrium and equilibrium charge distributions in celluloid films for incident Be, B, C, N, O ions are analyzed in order to obtain charge-exchange cross-sections. The determined 'effective' cross-sections of electron capture and loss in celluloid together with earlier measured analogous cross-sections in nitrogen allow us to calculate charge fractions F i (t) depending on the target thickness in solid (celluloid) and gaseous (nitrogen) matter. The absolute values and the ratios A cap =σ g i,i-1 /σ s i,i-1 and A loss =σ g i-1,i /σ s i-1,i of electron capture and loss cross-sections in {s} solids (celluloid, carbon) and {g} gases (nitrogen) are under consideration

  3. Behavior of solid matters and heavy metals during conductive drying process of sewage sludge

    Directory of Open Access Journals (Sweden)

    Jianping Luo

    2016-12-01

    Full Text Available Behavior of solid matters and heavy metals during conductive drying process of sewage sludge was evaluated in a sewage sludge disposal center in Beijing, China. The results showed most of solid matters could be retained in the dried sludge after drying. Just about 3.1% of solid matters were evaporated with steam mainly by the form of volatile fatty acids. Zn was the dominant heavy metal in the sludge, followed by Cu, Cr, Pb, Ni, Hg, and Cd. The heavy metals in the condensate were all below the detection limit except Hg. Hg in the condensate accounted for less than 0.1% of the total Hg. It can be concluded that most of the heavy metals are also retained in the dried sludge during the drying process, but their bioavailability could be changed significantly. The results are useful for sewage sludge utilization and its condensate treatment.

  4. Effect of minimum strength of mirror magnetic field (Bmin) on production of highly charged heavy ions from RIKEN liquid-He-free super conducting electron-cyclotron resonance ion source (RAMSES)

    International Nuclear Information System (INIS)

    Arai, Hideyuki; Imanaka, Masashi; Lee, S.-M.Sang-Moo; Higurashi, Yoshihide; Nakagawa, Takahide; Kidera, Masanori; Kageyama, Tadashi; Kase, Masayuki; Yano, Yasushige; Aihara, Toshimitsu

    2002-01-01

    We measured the beam intensity of highly charged heavy ions (O, Ar and Kr ions) as a function of the minimum strength of mirror magnetic field (B min ) of the RIKEN liquid-He-free super conducting electron-cyclotron resonance ion source. In this experiment, we found that the optimum value of B min exists to maximize the beam intensity of highly charged heavy ions and the value was almost the same (∼0.49 T) for various charge state heavy ions

  5. Microstructure and thermal conductivity of Mo-TiC cermets processed by hot isostatic pressing

    International Nuclear Information System (INIS)

    Le Flem, Marion; Allemand, Alexandre; Urvoy, Stephane; Cedat, Denis; Rey, Colette

    2008-01-01

    In the scope of refractory material development for structural applications in the core of future nuclear reactors (gas fast reactors working between 500 o C and at least 800 o C in nominal conditions and up to 1650 o C in accidental scenarios), five Mo-TiC cermets, and single-phase TiC and Mo, were processed by hot isostatic pressing. Starting TiC volume contents were 0%, 12.5%, 25%, 37.5%, 50%, 75% and 100%. First, high dense specimens were characterized in terms of microstructure, composition and phase volume fractions. Cermets exhibited two phases in agreement with phase diagram previsions (Mo-TiC 1-2at.% and TiC-Mo 10-15at.% ), and a residual non-reacted TiC-rich phase (TiC-Mo 1at.% ). Second, heat capacity and thermal diffusivity were measured up to 1000 o C which allowed to evaluate the thermal conductivity of each cermet: this lays between TiC conductivity (12-18 W/m K) and Mo conductivity (95-125 W/m K), thermal properties continuously decreasing with starting TiC content. An analytical approach based on the volume fraction and properties of each constituent allowed to highlight the existence of thermal resistance at the interphases at low temperature

  6. Increase of ionic conductivity in the microporous lithosilicate RUB-29 by Na-ion exchange processes

    International Nuclear Information System (INIS)

    Park, S.-H.; Senyshyn, A.; Paulmann, C.

    2007-01-01

    The ionic conductivity in the zeolite-like lithosilicate RUB-29 (Cs 14 Li 24 [Li 18 Si 72 O 172 ].14H 2 O [S.-H. Park, J.B. Parise, H. Gies, H. Liu, C.P. Grey, B.H. Toby, J. Am. Chem. Soc. 122 (2000) 11023-11024]) increases via simple ion-exchange processes, in particular when Na cations replace a part of Cs + and Li + of the material. The resulting ionic conductivity value of 3.2x10 -3 S cm -1 at 885 K is about two orders higher than that for the original material [S.-H. Park, J.B. Parise, M.E. Franke, T. Seydel, C. Paulmann, Micropor. Mesopor. Mater., in print ( (doi:10.1016/j.micromeso.2007.03.040) available online since April 19, 2007)]. The structural basis of a Na + -exchanged RUB-29 sample (Na-RUB-29) at 673 K could be elucidated by means of neutron powder diffraction. Rietveld refinements confirmed the replacement of Na + for both parts of Cs and Li cations, agreeing with idealized cell content, Na 8 Cs 8 Li 40 Si 72 O 172 . As a result of the incorporation of Na + in large pores, the number of Li + vacancies in dense Li 2 O-layers of the structure could increase. This can be one of the main reasons for the improved conductivity in Na-RUB-29. In addition, mobile Na cations may also contribute to the conductivity in Na-RUB-29 as continuous scattering length densities were found around the sites for Na in difference Fourier map. - Graphical abstract: Li 2 O-layers formed by edge- and corner-sharing LiO 4 - and LiO 3 -moieties in the zeolite-like lithosilicate RUB-29 provide optimal pathways for conducting Li + . The number of empty Li sites in this layer-like configuration could increase via 'simple' Na + -exchange processes, promoting fast Li motions

  7. Microstructural and Process Characterization of Conductive Traces Printed from Ag Particulate Inks

    Directory of Open Access Journals (Sweden)

    Eric MacDonald

    2011-05-01

    Full Text Available Conductive inks are key enablers for the use of printing techniques in the fabrication of electronic systems. Focus on the understanding of aspects controlling the electrical performance of conductive ink is paramount. A comparison was made between microparticle Ag inks and an Ag nanoparticle ink. The microstructures resulting from thermal cure processes were characterized morphologically and also in terms of their effect on the resistivity of printed traces. For microparticle inks, the variability of resistivity measurements between samples as defined by coefficient of variation (CV was greater than 0.1 when the resistivity was 10 to 50 times that of bulk Ag. When the resistivity was lower (~1.4 times that of bulk Ag the CV of sample sets was less than 0.1. In the case of the nanoparticle ink, resistivity was found to decrease by a factor ranging from 1.2 to 1.5 after doubling the amount of layers printed prior to curing though it was expected to remain the same. Increasing the amount of layers printed also enhanced the sintering process.

  8. Fundamental processes determining the highly charged ion production in ECR ion sources

    International Nuclear Information System (INIS)

    Shirkov, G.D.

    1992-01-01

    The ion confinement and loss conditions in the open magnetic traps have been analyzed in this article. In EGRIS the the ions are confined in the negative potential well. The simultaneous application of ion cooling and pulse regime is proposed for pulse injection of highly charged ions in heavy ion accelerators and storage rings. 14 refs.; 3 figs

  9. Processing of poly-Si electrodes for charge-coupled devices

    Energy Technology Data Exchange (ETDEWEB)

    Sherohman, J.W.; Cook, F.D.

    1978-12-06

    A technique has been developed to fabricate poly-Si electrodes for charge-coupled devices. By controlling the microstructure of a poly-Si film, an anisotropic etchant was selected to provide essentially uniform electrode width dimensions. The electrode widths have only a 6% variation for the majority of the devices over the area of a 2 inch silicon wafer.

  10. Optoelectronic processes at polymer-fullerene heterojunctions : charge transfer states in organic solar cells

    NARCIS (Netherlands)

    Di Nuzzo, D.

    2012-01-01

    Polymer photovoltaic cells currently achieve power conversion efficiencies (PCE) above 10% on lab scale. To compete with the efficiencies above 20% of inorganic solar cells, understanding and elimination of all the loss channels is necessary. This thesis investigates charge generation and

  11. Excessive Yield of Second Charged ions of Heavy Elements in Laser Plasma Expansion Process

    International Nuclear Information System (INIS)

    Kouznetsov, G.B.; Sysoev, A.A.

    2002-01-01

    LAMAS-IOM TOF-MS that was recently designed for inorganic quantitative analysis is also well suitable for investigation of laser irradiation interaction with solids. This feature allows one to analyze plasma on early stage and gives an excellent possibility to complete existent physical model. This work is dedicated to investigation of yield doubly charged ions for different elements

  12. Electrode Conduction Processes Segmented Electrode-Insulator Ratio Effects in MHD Power Generation Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pain, H. J.; Fearn, D. G.; Distefano, E. [Imperial College. London (United Kingdom)

    1966-10-15

    (a) Electrode conduction processes have been investigated using a plasma produced in an electromagnetic shock tube operating with argon at 70 {mu}mHg pressure. Complete voltage-current characteristics were obtained by the variation of load and applied voltage. These indicated the existence of two conduction regimes with a complex transition region. In the first regime the current, controlled by ion mobility, rose linearly with voltage to saturate between 10 mA and 1 A depending on conditions. Electrode contamination was significant. The second regime involved large currents controlled by electron mobility and emission from the cathode. The current again increased linearly with voltage and reached 200 A. Observation of induced voltages in transverse magnetic fields and of plasma deceleration in non-uniform fields showed that in the electromagnetic shock tube the plasma was heated predominantly by the driver discharge. Its conductivity was calculated using properties measured by a Langmuir double probe. In both regimes the plasma conductivity was also found from the gradient of the voltage current characteristics using experimental electric field fringing factors and the experimental values were compared with theory. (b) Larger-scale experiments used a combustion-driven shock tube where argon plasma flow, magnetic field and induced current flow were mutually orthogonal. The supersonic flow velocity and thermodynamic parameters of the plasma were accurately known. The electrode channel consisted of a segmented system of 12 electrode pairs with an electrode insulator ratio ranging from 1 to 21, with electrode plus insulator length remaining constant, and with maximum Hall parameter values of unity. Different electrode load combinations (Faraday and Hall generators) have been studied in measuring the power generated and the flow of longitudinal currents between adjacent electrodes. A maximum power of 0,8 MW was obtained, the power output decreasing inversely with the

  13. Electrode Conduction Processes Segmented Electrode-Insulator Ratio Effects in MHD Power Generation Experiments

    International Nuclear Information System (INIS)

    Pain, H.J.; Fearn, D.G.; Distefano, E.

    1966-01-01

    (a) Electrode conduction processes have been investigated using a plasma produced in an electromagnetic shock tube operating with argon at 70 μmHg pressure. Complete voltage-current characteristics were obtained by the variation of load and applied voltage. These indicated the existence of two conduction regimes with a complex transition region. In the first regime the current, controlled by ion mobility, rose linearly with voltage to saturate between 10 mA and 1 A depending on conditions. Electrode contamination was significant. The second regime involved large currents controlled by electron mobility and emission from the cathode. The current again increased linearly with voltage and reached 200 A. Observation of induced voltages in transverse magnetic fields and of plasma deceleration in non-uniform fields showed that in the electromagnetic shock tube the plasma was heated predominantly by the driver discharge. Its conductivity was calculated using properties measured by a Langmuir double probe. In both regimes the plasma conductivity was also found from the gradient of the voltage current characteristics using experimental electric field fringing factors and the experimental values were compared with theory. (b) Larger-scale experiments used a combustion-driven shock tube where argon plasma flow, magnetic field and induced current flow were mutually orthogonal. The supersonic flow velocity and thermodynamic parameters of the plasma were accurately known. The electrode channel consisted of a segmented system of 12 electrode pairs with an electrode insulator ratio ranging from 1 to 21, with electrode plus insulator length remaining constant, and with maximum Hall parameter values of unity. Different electrode load combinations (Faraday and Hall generators) have been studied in measuring the power generated and the flow of longitudinal currents between adjacent electrodes. A maximum power of 0,8 MW was obtained, the power output decreasing inversely with the

  14. Method for Signal Processing of Electric Field Modulation Sensor in a Conductive Environment

    Directory of Open Access Journals (Sweden)

    O. I. Miseyk

    2015-01-01

    Full Text Available In investigating the large waters and deep oceans the most promising are modulation sensors for measuring electric field in a conducting environment in a very low frequency range in devices of autonomous or non-autonomous vertical sounding. When using sensors of this type it is necessary to solve the problem of enhancement and measurement of the modulated signal from the baseband noise.The work analyses hydrodynamic and electromagnetic noise at the input of transducer with "rotating" sensitive axis. By virtue of matching the measuring electrodes with the signal processing circuit a conclusion has been drawn that the proposed basic model of a transducer with "rotating” sensitive axis is the most efficient in terms of enhancement and measurement of modulated signal from the baseband noise. It has been shown that it is undesirable for transducers to have the rotation of electrodes resulting, in this case, in arising noise to be synchronously changed with transducer rotation frequency (modulation frequency. This will complicate the further signal-noise enhancement later in their processing.The paper justifies the choice of demodulation output signal, called synchronous demodulation using a low-pass filter with a cutoff frequency much lower than the carrier frequency to provide an output signal in the range of very low frequency and dc electric fields.The paper offers an original circuit to process the signals taken from the modulation sensor with "rotating" measurement base. This circuit has advantages over the earlier known circuits for measuring electric fields in a conducting (marine environment in the ultralow frequency range of these fields in terms of sensitivity and measuring accuracy of modulation sensors.

  15. Investigation on transient flow of a centrifugal charging pump in the process of high pressure safety injection

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan, E-mail: zhangfan4060@gmail.com; Yuan, Shouqi; Fu, Qiang; Tao, Yi

    2015-11-15

    Highlights: • The transient flow characteristics of the charging pump with the first stage impeller in the HPSI process have been investigated numerically by CFD. • The hydraulic performance of the charging pump during the HPSI are discussed, andthe absolute errors between the simulated and measured results are analyzed in the paper. • Pressure fluctuation in the impeller and flow pattern in the impeller were studied in the HPSI process. It is influenced little at the beginning of the HPSI process while fluctuates strongly in the end of the HPSI process. - Abstract: In order to investigate the transient flow characteristics of the centrifugal charging pump during the transient transition process of high pressure safety injection (HPSI) from Q = 148 m{sup 3}/h to Q = 160 m{sup 3}/h, numerical simulation and experiment are implemented in this study. The transient flow rate, which is the most important factor, is obtained from the experiment and works as the boundary condition to accurately accomplish the numerical simulation in the transient process. Internal characteristics under the variable operating conditions are analyzed through the transient simulation. The results shows that the absolute error between the simulated and measured heads is less than 2.26% and the absolute error between the simulated and measured efficiency is less than 2.04%. Pressure fluctuation in the impeller is less influenced by variable flow rate in the HPSI process, while flow pattern in the impeller is getting better and better with the flow rate increasing. As flow rate increases, fluid blocks on the tongue of the volute and it strikes in this area at large flow rate. Correspondingly, the pressure fluctuation is intense and vortex occurs gradually during this period, which obviously lowers the efficiency of the pump. The contents of the current work can provide references for the design optimization and fluid control of the pump used in the transient process of variable operating

  16. Investigation on transient flow of a centrifugal charging pump in the process of high pressure safety injection

    International Nuclear Information System (INIS)

    Zhang, Fan; Yuan, Shouqi; Fu, Qiang; Tao, Yi

    2015-01-01

    Highlights: • The transient flow characteristics of the charging pump with the first stage impeller in the HPSI process have been investigated numerically by CFD. • The hydraulic performance of the charging pump during the HPSI are discussed, andthe absolute errors between the simulated and measured results are analyzed in the paper. • Pressure fluctuation in the impeller and flow pattern in the impeller were studied in the HPSI process. It is influenced little at the beginning of the HPSI process while fluctuates strongly in the end of the HPSI process. - Abstract: In order to investigate the transient flow characteristics of the centrifugal charging pump during the transient transition process of high pressure safety injection (HPSI) from Q = 148 m"3/h to Q = 160 m"3/h, numerical simulation and experiment are implemented in this study. The transient flow rate, which is the most important factor, is obtained from the experiment and works as the boundary condition to accurately accomplish the numerical simulation in the transient process. Internal characteristics under the variable operating conditions are analyzed through the transient simulation. The results shows that the absolute error between the simulated and measured heads is less than 2.26% and the absolute error between the simulated and measured efficiency is less than 2.04%. Pressure fluctuation in the impeller is less influenced by variable flow rate in the HPSI process, while flow pattern in the impeller is getting better and better with the flow rate increasing. As flow rate increases, fluid blocks on the tongue of the volute and it strikes in this area at large flow rate. Correspondingly, the pressure fluctuation is intense and vortex occurs gradually during this period, which obviously lowers the efficiency of the pump. The contents of the current work can provide references for the design optimization and fluid control of the pump used in the transient process of variable operating conditions.

  17. Angle resolved electron spectroscopy of spontaneous ionization processes occurring in doubly charged ion-surface collisions at grazing incidence

    International Nuclear Information System (INIS)

    Wouters, P.A.A.F.; Emmichoven, P.A.Z. van; Niehaus, A.

    1989-01-01

    The experimental setup used to measure electron spectra at well defined detection angles for grazing incidence doubly charged ion-surface collisions at keV-energies is described. Electron spectra are reported for the rare gas ions colliding with a Cu(110)-surface. The spectra are analyzed in terms of various spontaneous ionization processes using a newly developed model. It is found that double capture followed by atomic auto-ionization on the incoming trajectory and Auger-capture processes in which the first and second hole in the doubly charged projectiles are successively filled are the main processes contributing to the electron spectra. From a comparison of model calculations with measured spectra it is concluded that the metal electrons cannot adapt adiabatically to the sudden changes of the charge state of the projectile in front of the surface. A parameter characterizing the partly diabatic behavior is determined. The variation of spectra upon adsorption of a monolayer of oxygen on the surface is reported and discussed. (author)

  18. Determination of regression functions for the charging and discharging processes of valve regulated lead-acid batteries

    Directory of Open Access Journals (Sweden)

    Vukić Vladimir Đ.

    2012-01-01

    Full Text Available Following a deep discharge of AGM SVT 300 valve-regulated lead-acid batteries using the ten-hour discharge current, the batteries were charged using variable current. In accordance with the obtained results, exponential and polynomial functions for the approximation of the specified processes were analyzed. The main evaluation instrument for the quality of the implemented approximations was the adjusted coefficient of determination R-2. It was perceived that the battery discharge process might be successfully approximated with both an exponential and the second order polynomial function. On all the occasions analyzed, values of the adjusted coefficient of determination were greater than 0.995. The charging process of the deeply discharged batteries was successfully approximated with the exponential function; the measured values of the adjusted coefficient of determination being nearly 0.95. Apart from the high measured values of the adjusted coefficient of determination, polynomial approximations of the second and third order did not provide satisfactory results regarding the interpolation of the battery charging characteristics. A possibility for a practical implementation of the procured regression functions in uninterruptible power supply systems was described.

  19. Conduct of regulatory review and assessment during the licensing process for nuclear power plants

    International Nuclear Information System (INIS)

    1980-01-01

    This Safety Guide was prepared as part of the Agency's programme, referred to as the NUSS programme, for establishing Codes of Practice and Safety Guides relating to nuclear power plants. It supplements the Code of Practice on Governmental Organization for the Regulation of Nuclear Power Plants (IAEA Safety Series No. 50-C-G) and is concerned with the review and assessment by the regulatory body of all information submitted in support of licence applications, in the various phases of the licensing process. The purpose of the Guide is to provide information, recommendations and guidance for the conduct of these activities. The scope of the review and assessment will encompass the safety aspects of siting, construction, commissioning, operation and decommissioning of each nuclear power plant

  20. Conducting longitudinal, process-oriented research with conflict-affected youth: Solving the inevitable challenges.

    Science.gov (United States)

    Dubow, Eric F; Aber, J Lawrence; Betancourt, Theresa S; Cummings, E Mark; Huesmann, L Rowell

    2017-02-01

    The reader might get the impression that the four projects described in this Special Section proceeded in a systematic and predictable way. Of course, those of us engaged in each research project encountered pitfalls and challenges along the way. A main goal of this Special Section is to provide pathways and encouragement for those who may be interested in advancing high-quality research on this topic. In this paper, we describe a set of practical and ethical challenges that we encountered in conducting our longitudinal, process-oriented, and translational research with conflict-affected youth, and we illustrate how problems can be solved with the goal of maintaining the internal and external validity of the research designs. We are hopeful that by describing the challenges of our work, and how we overcame them, which are seldom treated in this or any other literature on research on child development in high-risk contexts, we can offer a realistic and encouraging picture of conducting methodologically sound research in conflict-affected contexts.

  1. Thermal process induced change of conductivity in As-doped ZnO

    Science.gov (United States)

    Su, S. C.; Fan, J. C.; Ling, C. C.

    2012-02-01

    Arsenic-doped ZnO films were fabricated by radio frequency magnetron sputtering method with different substrate temperature TS. Growing with the low substrate temperature of TS=200°C yielded n-type semi-insulating sample. Increasing the substrate temperature would yield p-type ZnO film and reproducible p-type film could be produced at TS~450°C. Post-growth annealing of the n-type As-doped ZnO sample grown at the low substrate temperature (TS=200°C) in air at 500°C also converted the film to p-type conductivity. Further increasing the post-growth annealing temperature would convert the p-type sample back to n-type. With the results obtained from the studies of positron annihilation spectroscopy (PAS), photoluminescence (PL), cathodoluminescence (CL), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS) and nuclear reaction analysis (NRA), we have proposed mechanisms to explain for the thermal process induced conduction type conversion as observed in the As-doped ZnO films.

  2. A novel conductive-polymer-based integration process for high-performance flip-chip packages

    Science.gov (United States)

    Lohokare, Saurabh

    Conductive polymers have recently attracted considerable attention for low-temperature fabrication of lead-free, reworkable, and flexible flip-chip interconnects. Using these materials, I demonstrate in this thesis a process that enables low-cost and high-resolution flip-chip interconnects using conventional micro-fabrication techniques. This fabrication process offers improved performance as compared to conventional flip-chip techniques, such as screen-printing, and allows for definition of interconnects with excellent surface uniformity and control over the bump profile. In order to demonstrate the utility and wide applicability of this process, several test implementations that serve as case studies were investigated. Specifically, novel InGaAsSb avalanche photodiodes (APDs), operating around lambda = 2m and targeted for free-space communication and biomedical spectroscopy applications, were fabricated and flip-chip-integrated to test the static electrical characteristics of the polymer bumps. Additionally, the dynamic electrical performance characteristics of the polymer bumps were studied by using AlGaAsSb/AlGaSb p-i-n photodetectors as a case study. The fabrication of these photodetectors, operating around lambda = 1.55mum and targeted for optical communication applications, was accomplished using a customized inductively coupled plasma (ICP) etch process that resulted in a low dark current and excellent speed (3dB bandwidth of 10GHz) and, responsivity (60% external quantum efficiency) characteristics. Furthermore, flip-chip integration was used to demonstrate a three-dimensional, point-to-point micro-optical interconnect, which was 2.33mm-long in a system 15.27mm3 in volume. Lastly, high-speed parallel optical interconnects were demonstrated using polymer-flip-chip-integrated 10GHz vertical-cavity surface-emitting laser (VCSEL) and DOEs. Such interconnects offer the ability to alleviate the communication bottleneck that is projected to occur in future, high

  3. Solution processed ternary blend nano-composite charge regulation layer to enhance inverted OLED performances

    Science.gov (United States)

    Kaçar, Rifat; Mucur, Selin Pıravadılı; Yıldız, Fikret; Dabak, Salih; Tekin, Emine

    2018-04-01

    Inverted bottom-emission organic light emitting diodes (IBOLEDs) have attracted increasing attention due to their exceptional air stability and applications in active-matrix displays. For gaining high IBOLED device efficiencies, it is crucial to develop an effective strategy to make the bottom electrode easy for charge injection and transport. Charge selectivity, blocking the carrier flow towards the unfavourable side, plays an important role in determining charge carrier balance and accordingly radiative recombination efficiency. It is therefore highly desirable to functionalize an interfacial layer which will perform many different tasks simultaneously. Here, we contribute to the hole-blocking ability of the zinc oxide/polyethyleneimine (ZnO:PEI) nano-composite (NC) interlayer with the intention of increasing the OLED device efficiency. With this purpose in mind, a small amount of 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBi) was added as a hole-blocking molecule into the binary blend of ZnO and PEI solution. The device with a ternary ZnO:PEI:TPBi NC interlayer achieved a maximum current efficiency of 38.20 cd A-1 and a power efficiency of 34.29 lm W-1 with a luminance of 123 200 cd m-2, which are high performance parameters for inverted device architecture. The direct comparisons of device performances incorporating ZnO only, ZnO/PEI bilayers, and ZnO:PEI binary NC counterparts were also performed, which shed light on the origin of device performance enhancement.

  4. Heterogeneous nucleation in multi-component vapor on a partially wettable charged conducting particle. II. The generalized Laplace, Gibbs-Kelvin, and Young equations and application to nucleation.

    Science.gov (United States)

    Noppel, M; Vehkamäki, H; Winkler, P M; Kulmala, M; Wagner, P E

    2013-10-07

    Based on the results of a previous paper [M. Noppel, H. Vehkamäki, P. M. Winkler, M. Kulmala, and P. E. Wagner, J. Chem. Phys. 139, 134107 (2013)], we derive a thermodynamically consistent expression for reversible or minimal work needed to form a dielectric liquid nucleus of a new phase on a charged insoluble conducting sphere within a uniform macroscopic one- or multicomponent mother phase. The currently available model for ion-induced nucleation assumes complete spherical symmetry of the system, implying that the seed ion is immediately surrounded by the condensing liquid from all sides. We take a step further and treat more realistic geometries, where a cap-shaped liquid cluster forms on the surface of the seed particle. We derive the equilibrium conditions for such a cluster. The equalities of chemical potentials of each species between the nucleus and the vapor represent the conditions of chemical equilibrium. The generalized Young equation that relates contact angle with surface tensions, surface excess polarizations, and line tension, also containing the electrical contribution from triple line excess polarization, expresses the condition of thermodynamic equilibrium at three-phase contact line. The generalized Laplace equation gives the condition of mechanical equilibrium at vapor-liquid dividing surface: it relates generalized pressures in neighboring bulk phases at an interface with surface tension, excess surface polarization, and dielectric displacements in neighboring phases with two principal radii of surface curvature and curvatures of equipotential surfaces in neighboring phases at that point. We also re-express the generalized Laplace equation as a partial differential equation, which, along with electrostatic Laplace equations for bulk phases, determines the shape of a nucleus. We derive expressions that are suitable for calculations of the size and composition of a critical nucleus (generalized version of the classical Kelvin-Thomson equation).

  5. Treatment of transparent conductive oxides by laser processes for the development of Silicon photovoltaic cells

    International Nuclear Information System (INIS)

    Canteli Perez-Caballero, D.

    2015-01-01

    Transparent conductive oxides (TCOs) are heavily doped oxides with high transparency in the visible range of the spectrum and a very low sheet resistance, making them very attractive for applications in optoelectronic devices. TCOs are widely found in many different areas such as low emissivity windows, electric contacts in computers, televisions or portable devices, and, specially, in the photovoltaic (PV) industry. PV industry is mainly based on mono- and multicrystalline silicon, where TCOs are used as anti-reflective coatings, but the search for cheaper, alternative technologies has led to the development of thin film PV technologies, where TCOs are used as transparent contacts. With the maturation of the thin film PV industry, laser sources have become an essential tool, allowing the improvement of some industrial processes and the development of new ones. Because of the interest on a deeper understanding of the interaction processes between laser light and TCOs, the laser ablation of three of the most important TCOs has been studied in depth in the present work. (Author)

  6. A comparative theoretical study of exciton-dissociation and charge-recombination processes in oligothiophene/fullerene and oligothiophene/perylenediimide complexes for organic solar cells

    KAUST Repository

    Yi, Yuanping

    2011-01-01

    The exciton-dissociation and charge-recombination processes in donor-acceptor complexes found in α-sexithienyl/C60 and α-sexithienyl/perylenetetracarboxydiimide (PDI) solar cells are investigated by means of quantum-chemical methods. The electronic couplings and exciton-dissociation and charge-recombination rates have been evaluated for various configurations of the complexes. The results suggest that the decay of the lowest charge-transfer state to the ground state in the PDI-based devices: (i) is faster than that in the fullerene-based devices and (ii) in most cases, can compete with the dissociation of the charge-transfer state into mobile charge carriers. This faster charge-recombination process is consistent with the lower performance observed experimentally for the devices using PDI derivatives as the acceptor. © 2011 The Royal Society of Chemistry.

  7. Highly Conductive Cu 2– x S Nanoparticle Films through Room-Temperature Processing and an Order of Magnitude Enhancement of Conductivity via Electrophoretic Deposition

    KAUST Repository

    Otelaja, Obafemi O.

    2014-11-12

    © 2014 American Chemical Society. A facile room-temperature method for assembling colloidal copper sulfide (Cu2-xS) nanoparticles into highly electrically conducting films is presented. Ammonium sulfide is utilized for connecting the nanoparticles via ligand removal, which transforms the as-deposited insulating films into highly conducting films. Electronic properties of the treated films are characterized with a combination of Hall effect measurements, field-effect transistor measurements, temperature-dependent conductivity measurements, and capacitance-voltage measurements, revealing their highly doped p-type semiconducting nature. The spin-cast nanoparticle films have carrier concentration of ∼1019 cm-3, Hall mobilities of ∼3 to 4 cm2 V-1 s-1, and electrical conductivities of ∼5 to 6 S·cm-1. Our films have hole mobilities that are 1-4 orders of magnitude higher than hole mobilities previously reported for heat-treated nanoparticle films of HgTe, InSb, PbS, PbTe, and PbSe. We show that electrophoretic deposition (EPD) as a method for nanoparticle film assembly leads to an order of magnitude enhancement in film conductivity (∼75 S·cm-1) over conventional spin-casting, creating copper sulfide nanoparticle films with conductivities comparable to bulk films formed through physical deposition methods. The X-ray diffraction patterns of the Cu2-xS films, with and without ligand removal, match the Djurleite phase (Cu1.94S) of copper sulfide and show that the nanoparticles maintain finite size after the ammonium sulfide processing. The high conductivities reported are attributed to better interparticle coupling through the ammonium sulfide treatment. This approach presents a scalable room-temperature route for fabricating highly conducting nanoparticle assemblies for large-area electronic and optoelectronic applications.

  8. Highly processable method for the construction of miniature conducting polymer moisture sensors

    Science.gov (United States)

    McGovern, Scott T.; Spinks, Geoffrey M.; Wallace, Gordon G.

    2005-02-01

    A polymer blend incorporating polyaniline (PAn) was used as a sensing medium in the construction of a resistance based humidity sensor. Aniline monomer was polymerised to PAn emeraldine salt (ES) in the presence of poly (butyl acrylate-co-vinyl acetate) and the processable blend was developed by redissolving 1-2 w/w% of the resulting sensing polymer residue in dichloromethane (DCM). Some of this residue was washed in ammonia solution to de-dope the PAn to emeraldine base (EB) to act as a protective layer on the surface of the sensing polymer. This residue was then washed with distilled water until a neutral pH was realised with the waste water, dried and redissolved in DCM at 1-2 w/w% to create a processable blend barrier polymer solution. The final sensor design utilised 125μm polyester insulated platinum wire as conducting electrodes that were dip coated in the PAn ES blend solution and dried in a desiccator. A protective coating was then applied by dip coating in the EB blend solution. The sensors had an overall final thickness of less than 200μm and showed high sensitivity to humidity, low resistance, and good reversibility without hysteresis. The EB protective layer was shown to give more stable and predictable responses to the sensors when placed inside curing epoxies. Polymer based thin film humidity sensors have the advantage that the high processability of the material allows for simple fabrication of a range of geometries including smaller sensor designs. Such sensors may find uses in detecting water content in a number of areas including composite materials, electronic textiles, food/electronics packaging and corrosion detection.

  9. Particle deposition in a realistic geometry of the human conducting airways: Effects of inlet velocity profile, inhalation flowrate and electrostatic charge

    DEFF Research Database (Denmark)

    Koullapis, P. G.; Kassinos, S. C.; Bivolarova, Mariya Petrova

    2016-01-01

    of inlet flow conditions, particle size, electrostatic charge, and flowrate. While most computer simulations assume a uniform velocity at the mouth inlet, we found that using a more realistic inlet profile based on Laser Doppler Anemometry measurements resulted in enhanced deposition, mostly on the tongue...... between particle size, electrostatic charge, and flowrate. Our results suggest that in silico models should be customized for specific applications, ensuring all relevant physical effects are accounted for in a self-consistent fashion....

  10. Investigation of the charge exchange process π-d→π0nn

    International Nuclear Information System (INIS)

    Il-Tong Cheon.

    1978-02-01

    The transition rate has been calculated for the charge exchange of stopped π - in the deuteron. The present result is hω(π - d→π 0 nn)=0.695x10 -4 eV. Making use of the value hω(π - d→nn)=0.682 eV, which was previously obtained, estimated the branching ratio ω(π - d→π 0 nn)|ω(π - d→nn)=1.02x10 -4 has been estimated

  11. Phase slip process and charge density wave dynamics in a one dimensional conductor

    Science.gov (United States)

    Habiballah, N.; Zouadi, M.; Arbaoui, A.; Qjani, M.; Dumas, J.

    In this paper, we study the phase slip effect on the charge density wave (CDW) dynamics in a one-dimensional conductor in the weak pinning limit. A considerable enhancement of JCDW is observed in the presence of phase slips. In addition, a spatial dependence of the CDW current density JCDW is also studied showing that a decrease of JCDW with distance from the current contact occurs. The results are discussed in terms the relationship between additional phase slips and the mobility of phase dislocations nucleated at electrical contacts.

  12. Loss pattern of Pb ions with charge changing processes in the LEIR ring

    CERN Document Server

    Pasternak, J

    2004-01-01

    Avalanche like pressure rise and an associated decrease of the beam lifetime, caused by (i) beam loss due to charge exchange interactions with rest gas molecules and (ii) ion impact induced outgassing, is a potential limitation for heavy ion accelerators. The vacuum system of the LEIR ring has to be upgraded carefully to avoid that these phenomena prevent the machine from reaching design performance. The loss pattern of Pb ions having captured an electron presented in this report allows to estimate whether the low dynamic pressure needed for LEIR is reachable. Efficient interception of lost ions with low beam loss induced outgassing absorber blocks, installed at appropriate locations is promising.

  13. Heat exchange between a microparticle and plasma. Contribution of charge transfer processes

    International Nuclear Information System (INIS)

    Uglov, A.A.; Gnedovets, A.G.

    1983-01-01

    Heat- and mass-transfer in interaction of a microparticle with a dense plasma have been considered analytically. At that, calculation methods developed as applied to probe diagnostics of slightly ionized plasma are also used in the case of relatively high degrees of ionization, at which heat flows of plasma charged particles Qe and Qi become comparable with molecular ones. High efficiency of energy transfer during electron and ion collisions with a microparticle is due to the following: 1) effective cross section of ion collision with a microparticle, which acquires in a quasineutral plasma the potential phisub(f) < 0, surpasses the geometric one; the maximum contribution of electron and ion constituent is achieved when the cross section ion collisions with a microparticle is linearly connected with its potential, 2) with a charged microparticle electrons from distribution function ''tail'' collide, their energy exceeds potential barrier near the surface and, consequently, the mean heat energy; 3) besides the energy of a microparticle thermal movement during electron recombination and ion neutralization on its surface the heat Qsub(e) and Qsub(i), which considerably exceed the heat of molecular adsorption and mean heat energy of plasma particles at kT approximately 1 eV, are transmitted to the microparticle

  14. Development of Charge Sensitive Preamplifier and Readout Integrate Circuit Board for High Resolution Detector using ASIC Process

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, J. Y.; Kim, J. H.; Park, J. M.; Yang, J. Y.; Kim, K. Y.; Kim, Y. S. [RadTek Co., Daejeon (Korea, Republic of)

    2010-06-15

    - Design of discrete type charge sensitive amplifier for high resolution semi-conductor sensor - Design and develop the test board for the performance of charge sensitive amplifier with sensor - Performance of electrical test for the sensor and charge sensitive amplifier - Development of prototype 8 x 8 array type detector module - Noise equivalent charge test for the charge sensitive amplifier - Design and development of Micro SMD discrete type amplifier applying ASIC procedure - Development of Hybrid type charge sensitive amplifier including shape

  15. Coupling between electroosmotically driven flow and bipolar faradaic depolarization processes in electron-conducting microchannels

    NARCIS (Netherlands)

    Qian, S.Z.; Duval, J.F.L.

    2006-01-01

    A quantitative theory is proposed for the analysis of steady electroosmotically driven flows within conducting cylindrical microchannels. Beyond a threshold value of the electric field applied in the electrolyte Solution and parallel to the conducting surface, electrochemical oxidation and reduction

  16. Optimization of Process Variables for Insulation Coating of Conductive Particles by Response Surface Methodology

    International Nuclear Information System (INIS)

    Sim, Chol-Ho

    2016-01-01

    The powder core, conventionally fabricated from iron particles coated with insulator, showed large eddy current loss under high frequency, because of small specific resistance. To overcome the eddy current loss, the increase in the specific resistance of powder cores was needed. In this study, copper oxide coating onto electrically conductive iron particles was performed using a planetary ball mill to increase the specific resistance. Coating factors were optimized by the Response surface methodology. The independent variables were the CuO mass fraction, mill revolution number, coating time, ball size, ball mass and sample mass. The response variable was the specific resistance. The optimization of six factors by the fractional factorial design indicated that CuO mass fraction, mill revolution number, and coating time were the key factors. The levels of these three factors were selected by the three-factors full factorial design and steepest ascent method. The steepest ascent method was used to approach the optimum range for maximum specific resistance. The Box-Behnken design was finally used to analyze the response surfaces of the screened factors for further optimization. The results of the Box-Behnken design showed that the CuO mass fraction and mill revolution number were the main factors affecting the efficiency of coating process. As the CuO mass fraction increased, the specific resistance increased. In contrast, the specific resistance increased with decreasing mill revolution number. The process optimization results revealed a high agreement between the experimental and the predicted data (Adj-R2=0.944). The optimized CuO mass fraction, mill revolution number, and coating time were 0.4, 200 rpm, and 15 min, respectively. The measured value of the specific resistance of the coated pellet under the optimized conditions of the maximum specific resistance was 530 kΩ·cm

  17. Optimization of Process Variables for Insulation Coating of Conductive Particles by Response Surface Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Chol-Ho [Sangji University, Wonju (Korea, Republic of)

    2016-02-15

    The powder core, conventionally fabricated from iron particles coated with insulator, showed large eddy current loss under high frequency, because of small specific resistance. To overcome the eddy current loss, the increase in the specific resistance of powder cores was needed. In this study, copper oxide coating onto electrically conductive iron particles was performed using a planetary ball mill to increase the specific resistance. Coating factors were optimized by the Response surface methodology. The independent variables were the CuO mass fraction, mill revolution number, coating time, ball size, ball mass and sample mass. The response variable was the specific resistance. The optimization of six factors by the fractional factorial design indicated that CuO mass fraction, mill revolution number, and coating time were the key factors. The levels of these three factors were selected by the three-factors full factorial design and steepest ascent method. The steepest ascent method was used to approach the optimum range for maximum specific resistance. The Box-Behnken design was finally used to analyze the response surfaces of the screened factors for further optimization. The results of the Box-Behnken design showed that the CuO mass fraction and mill revolution number were the main factors affecting the efficiency of coating process. As the CuO mass fraction increased, the specific resistance increased. In contrast, the specific resistance increased with decreasing mill revolution number. The process optimization results revealed a high agreement between the experimental and the predicted data (Adj-R2=0.944). The optimized CuO mass fraction, mill revolution number, and coating time were 0.4, 200 rpm, and 15 min, respectively. The measured value of the specific resistance of the coated pellet under the optimized conditions of the maximum specific resistance was 530 kΩ·cm.

  18. Cystic fibrosis transmembrane conductance regulator intracellular processing, trafficking, and opportunities for mutation-specific treatment.

    LENUS (Irish Health Repository)

    Rogan, Mark P

    2012-02-01

    Recent advances in basic science have greatly expanded our understanding of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR), the chloride and bicarbonate channel that is encoded by the gene, which is mutated in patients with CF. We review the structure, function, biosynthetic processing, and intracellular trafficking of CFTR and discuss the five classes of mutations and their impact on the CF phenotype. The therapeutic discussion is focused on the significant progress toward CFTR mutation-specific therapies. We review the results of encouraging clinical trials examining orally administered therapeutics, including agents that promote read-through of class I mutations (premature termination codons); correctors, which overcome the CFTR misfolding that characterizes the common class II mutation F508del; and potentiators, which enhance the function of class III or IV mutated CFTR at the plasma membrane. Long-term outcomes from successful mutation-specific treatments could finally answer the question that has been lingering since and even before the CFTR gene discovery: Will therapies that specifically restore CFTR-mediated chloride secretion slow or arrest the deleterious cascade of events leading to chronic infection, bronchiectasis, and end-stage lung disease?

  19. Suppression of persistent photo-conductance in solution-processed amorphous oxide thin-film transistors

    Science.gov (United States)

    Lee, Minkyung; Kim, Minho; Jo, Jeong-Wan; Park, Sung Kyu; Kim, Yong-Hoon

    2018-01-01

    This study offers a combinatorial approach for suppressing the persistent photo-conductance (PPC) characteristic in solution-processed amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) in order to achieve rapid photo-recovery. Various analyses were used to examine the photo-instability of indium-gallium-zinc-oxide (IGZO) TFTs including negative-bias-illumination-stress (NBIS) and transient photo-response behaviors. It was found that the indium ratio in metallic components had a significant impact on their PPC and photo-recovery characteristics. In particular, when the indium ratio was low (51.5%), the PPC characteristic was significantly suppressed and achieving rapid photo-recovery was possible without significantly affecting the electrical performance of AOSs. These results imply that the optimization of the indium composition ratio may allow achieving highly photo-stable and near PPC-free characteristics while maintaining high electrical performance of AOSs. It is considered that the negligible PPC behavior and rapid photo-recovery observed in IGZO TFTs with a lower indium composition are attributed to the less activation energy required for the neutralization of ionized oxygen vacancies.

  20. Charge-changing processes of heavy ions in matter. Non-equilibrium charge state distribution of sulfur ions after carbon foil penetration

    International Nuclear Information System (INIS)

    Imai, Makoto; Shibata, Hiromi; Sataka, Masao; Sugai, Hiroyuki; Nishio, Katsuhisa; Sugiyama, Koji; Komaki, Ken-ichiro

    2005-01-01

    Charge state distributions of 2.0 MeV/u (64 MeV) sulfur ions of various initial charge states (6+, 10+, 11+, 13+) after passing through 0.9, 1.1, 1.5, 2.0, 3.0, 4.7, 6.9 and 10 μg/cm 2 carbon foils have been studied experimentally using the heavy ion spectrometer 'ENMA'. Measured charge state distributions do not flat off to establish equilibrium within the measured thickness, proving to be the first systematic measurement of non-equilibrium charge state distribution using solid target at this energy range. The mean charge states and their distribution widths almost saturate to 12.4 and 1.03, respectively, for all initial charge states examined. Calculation with ETACHA code, developed by Rozet et al. [Nucl. Instr. and Meth. B 107 (1996) 67], is employed, although the present impact energy is lower than the assumed energy region for this code. It was also confirmed that a certain portion of 16 O q+ (q=3, 4, 7) beam is included in 32 S q+ (q=6, 8, 14) beam provided from the Tandem Accelerator, which originates in the Negative Ion Source forming O 2 - . (author)

  1. A salt water battery with high stability and charging rates made from solution processed conjugated polymers with polar side chains

    KAUST Repository

    Moia, Davide

    2017-11-28

    We report a neutral salt water based battery which uses p-type and n-type solution processed polymer films as the cathode and the anode of the cell. The specific capacity of the electrodes (approximately 30 mAh cm-3) is achieved via formation of bipolarons in both the p-type and n-type polymers. By engineering ethylene glycol and zwitterion based side chains attached to the polymer backbone we facilitate rapid ion transport through the non-porous polymer films. This, combined with efficient transport of electronic charge via the conjugated polymer backbones, allowed the films to maintain constant capacity at high charge and discharge rates (>1000 C-rate). The electrodes also show good stability during electrochemical cycling (less than 30% decrease in capacity over >1000 cycles) and an output voltage up to 1.4 V. The performance of these semiconducting polymers with polar side-chains demonstrates the potential of this material class for fast-charging, water based electrochemical energy storage devices.

  2. Charge transport and dielectric relaxation processes in anilin-based oligomers

    Czech Academy of Sciences Publication Activity Database

    Mrlík, M.; Moučka, R.; Ilčíková, M.; Bober, Patrycja; Kazantseva, N.; Špitálský, Z.; Trchová, Miroslava; Stejskal, Jaroslav

    2014-01-01

    Roč. 192, June (2014), s. 37-42 ISSN 0379-6779 Institutional support: RVO:61389013 Keywords : aniline-based oligomers * conductivity * dielectric properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.252, year: 2014

  3. Charge generation layers for solution processed tandem organic light emitting diodes with regular device architecture.

    Science.gov (United States)

    Höfle, Stefan; Bernhard, Christoph; Bruns, Michael; Kübel, Christian; Scherer, Torsten; Lemmer, Uli; Colsmann, Alexander

    2015-04-22

    Tandem organic light emitting diodes (OLEDs) utilizing fluorescent polymers in both sub-OLEDs and a regular device architecture were fabricated from solution, and their structure and performance characterized. The charge carrier generation layer comprised a zinc oxide layer, modified by a polyethylenimine interface dipole, for electron injection and either MoO3, WO3, or VOx for hole injection into the adjacent sub-OLEDs. ToF-SIMS investigations and STEM-EDX mapping verified the distinct functional layers throughout the layer stack. At a given device current density, the current efficiencies of both sub-OLEDs add up to a maximum of 25 cd/A, indicating a properly working tandem OLED.

  4. Development of ZnO based charged particle monitor for processing facility

    International Nuclear Information System (INIS)

    Yanagida, Takayuki; Kawaguchi, Noriaki; Fujimoto, Yutaka

    2011-01-01

    In the present paper, we describe the development of an α-ray imaging detector based on a ZnO single crystalline scintillator and a position-sensitive photomultiplier tube (PSPMT). The ZnO crystal was grown by the hydrothermal synthesis method with 2-in.-φ in diameter. The ZnO specimen was polished but to be 0.5 mm in thickness. After optically coupling with PSPMT, the crystal was irradiated with, 241 Am α-ray for evaluation of both spatial resolution and pulse height spectrum. Using the charge center of the gravity method, two-dimensional α-ray images were successfully obtained. The efficiency of the energy window in terms of imaging quality was also examined. (author)

  5. Solution-processed highly conductive PEDOT:PSS/AgNW/GO transparent film for efficient organic-Si hybrid solar cells.

    Science.gov (United States)

    Xu, Qiaojing; Song, Tao; Cui, Wei; Liu, Yuqiang; Xu, Weidong; Lee, Shuit-Tong; Sun, Baoquan

    2015-02-11

    Hybrid solar cells based on n-Si/poly(3,4-ethylenedioxythiophene):poly(styrene- sulfonate) (PEDOT:PSS) heterojunction promise to be a low cost photovoltaic technology by using simple device structure and easy fabrication process. However, due to the low conductivity of PEDOT:PSS, a metal grid deposited by vacuum evaporation method is still required to enhance the charge collection efficiency, which complicates the device fabrication process. Here, a solution-processed graphene oxide (GO)-welded silver nanowires (AgNWs) transparent conductive electrode (TCE) was employed to replace the vacuum deposited metal grid. A unique "sandwich" structure was developed by embedding an AgNW network between PEDOT:PSS and GO with a figure-of-merit of 8.6×10(-3) Ω(-1), which was even higher than that of sputtered indium tin oxide electrode (6.6×10(-3) Ω(-1)). A champion power conversion efficiency of 13.3% was achieved, because of the decreased series resistance of the TCEs as well as the enhanced built-in potential (Vbi) in the hybrid solar cells. The TCEs were obtained by facile low-temperature solution process method, which was compatible with cost-effective mass production technology.

  6. Effect of process parameters on microstructure and electrical conductivity during FSW of Al-6101 and Pure Copper

    Science.gov (United States)

    Sharma, Nidhi; Khan, Zahid A.; Siddiquee, Arshad Noor; Shihab, Suha K.; Atif Wahid, Mohd

    2018-04-01

    Copper (Cu) is predominantly used material as a conducting element in electrical and electronic components due to its high conductivity. Aluminum (Al) being lighter in weight and more conductive on weight basis than that of Cu is able to replace or partially replace Cu to make lighter and cost effective electrical components. Conventional methods of joining Al to Cu, such as, fusion welding process have many shortcomings. Friction Stir Welding (FSW) is a solid state welding process which overcomes the shortcoming of the fusion welding. FSW parameters affect the mechanical and electrical properties of the joint. This study aims to evaluate the effect of different process parameters such as shoulder diameter, pin offset, welding and rotational speed on the microstructure and electrical conductivity of the dissimilar Al-Cu joint. FSW is performed using cylindrical pin profile, and four process parameters. Each parameter at different levels is varied according to Taguchi’s L18 standard orthogonal array. It is found that the electrical conductivity of the FSWed joints are equal to that of aluminum at all the welded sections. FSW is found to be an effective technique to join Al to Cu without compromising with the electrical properties. However, the electrical conductivity gets influenced by the process parameters in the stir zone. The optimal combination of the FSW parameters for maximum electrical conductivity is determined. The analysis of variance (ANOVA) technique applied on stir zone suggests that the rotational speed and tool pin offset are the significant parameters to influence the electrical conductivity.

  7. Charge Transport in LDPE Nanocomposites Part II—Computational Approach

    Directory of Open Access Journals (Sweden)

    Anh T. Hoang

    2016-03-01

    Full Text Available A bipolar charge transport model is employed to investigate the remarkable reduction in dc conductivity of low-density polyethylene (LDPE based material filled with uncoated nanofillers (reported in the first part of this work. The effect of temperature on charge transport is considered and the model outcomes are compared with measured conduction currents. The simulations reveal that the contribution of charge carrier recombination to the total transport process becomes more significant at elevated temperatures. Among the effects caused by the presence of nanoparticles, a reduced charge injection at electrodes has been found as the most essential one. Possible mechanisms for charge injection at different temperatures are therefore discussed.

  8. Optimizing Compliance and Thermal Conductivity of Plasma Sprayed Thermal Barrier Coatings via Controlled Powders and Processing Strategies

    Science.gov (United States)

    Tan, Yang; Srinivasan, Vasudevan; Nakamura, Toshio; Sampath, Sanjay; Bertrand, Pierre; Bertrand, Ghislaine

    2012-09-01

    The properties and performance of plasma-sprayed thermal barrier coatings (TBCs) are strongly dependent on the microstructural defects, which are affected by starting powder morphology and processing conditions. Of particular interest is the use of hollow powders which not only allow for efficient melting of zirconia ceramics but also produce lower conductivity and more compliant coatings. Typical industrial hollow spray powders have an assortment of densities resulting in masking potential advantages of the hollow morphology. In this study, we have conducted process mapping strategies using a novel uniform shell thickness hollow powder to control the defect microstructure and properties. Correlations among coating properties, microstructure, and processing reveal feasibility to produce highly compliant and low conductivity TBC through a combination of optimized feedstock and processing conditions. The results are presented through the framework of process maps establishing correlations among process, microstructure, and properties and providing opportunities for optimization of TBCs.

  9. Social Information Processing of Positive and Negative Hypothetical Events in Children with ADHD and Conduct Problems and Controls

    Science.gov (United States)

    Andrade, Brendan F.; Waschbusch, Daniel A.; Doucet, Amelie; King, Sara; MacKinnon, Maura; McGrath, Patrick J.; Stewart, Sherry H.; Corkum, Penny

    2012-01-01

    Objective: This study examined social information processing (SIP) of events with varied outcomes in children with ADHD and conduct problems (CPs; defined as oppositional defiant disorder [ODD] or conduct disorder [CD]) and controls. Method: Participants were 64 children (46 boys, 18 girls) aged 6 to 12, including 39 with ADHD and 25 controls.…

  10. Exciton-Dissociation and Charge-Recombination Processes in Pentacene/C 60 Solar Cells: Theoretical Insight into the Impact of Interface Geometry

    KAUST Repository

    Yi, Yuanping; Coropceanu, Veaceslav; Brédas, Jean-Luc

    2009-01-01

    The exciton-dissociation and charge-recombination processes in organic solar cells based on pentacene/C60 heterojunctions are investigated by means of quantum-mechanical calculations. The electronic couplings and the rates of exciton dissociation

  11. Charge changing processes in the formation of fast H0 atoms

    International Nuclear Information System (INIS)

    Anderson, C.J.

    1979-01-01

    Measurements are reported of the charge changing cross sections sigma- 0 , sigma-/sub +/, sigma/sub g+/ sigma/sub g-/ for H - ions incident on Ne, Ar, Kr, Xe, Li, Na, K, Rb and Cs targets in the energy range 25 to 200 keV. The maximum neutral fractions, F 0 /sup max/, for H - ions incident on H 2 , D 2 , CO 2 , H 2 O, C 4 H 10 , C 5 H 12 , CF 4 , CHF 3 , CClF 3 , CBrF 3 , acetone, 2-propanol and natural gas have been measured in the energy range 30 to 200 keV. The largest neutral fraction for 100 keV H - is 0.631 produced in a Li vapor target. The equilibrium fractions F/sub -//sup infinity/, F 0 /sup infinity/ and F/sub +//sup infinity/ for H - ions incident on H 2 , He, Ne, Ar, Kr, Xe, Li, Na, K, Rb and Cs have been measured in the energy range 30 to 200 keV. Also measured are the cross sections sigma/sub +0/ and sigma/sub +-/ and the equilibrium fractions F/sub -//sup infinity/, F 0 /sup infinity/ and F/sub +//sup infinity/ for H + incident on a Na target in the energy range 1-25 keV. The largest value of F/sub -//sup infinity/ is 0.101 for H + incident at 2 keV

  12. Thermoelectric Properties of Solution-Processed n-Doped Ladder-Type Conducting Polymers

    DEFF Research Database (Denmark)

    Wang, Suhao; Sun, Hengda; Ail, Ujwala

    2016-01-01

    Ladder-type "torsion-free" conducting polymers (e.g., polybenzimidazobenzophenanthroline (BBL)) can outperform "structurally distorted" donor-acceptor polymers (e.g., P(NDI2OD-T2)), in terms of conductivity and thermoelectric power factor. The polaron delocalization length is larger in BBL than...... in P(NDI2OD-T2), resulting in a higher measured polaron mobility. Structure-function relationships are drawn, setting material-design guidelines for the next generation of conducting thermoelectric polymers....

  13. Analysis of the charge collection process in solid state X-ray detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kimmel, Nils

    2009-02-12

    Physics with X-rays spans from observing large scales in X-ray astronomy down to small scales in material structure analyses with synchrotron radiation. Both fields of research require imaging detectors featuring spectroscopic resolution for X-rays in an energy range of 0.1 keV to 20.0 keV. Originally driven by the need for an imaging spectrometer on ESA's X-ray astronomy satellite mission XMM-Newton, X-ray pnCCDs were developed at the semiconductor laboratory of the Max-Planck-Institute. The pnCCD is a pixel array detector made of silicon. It is sensitive over a wide band from near infrared- over optical- and UV-radiation up to X-rays. This thesis describes the dynamics of signal electrons from the moment after their generation until their collection in the potential minima of the pixel structure. Experimentally, a pinhole array was used to scan the pnCCD surface with high spatial resolution. Numerical simulations were used as a tool for the modeling of the electrical conditions inside the pnCCD. The results predicted by the simulations were compared with the measurements. Both, experiment and simulation, helped to establish a model for the signal charge dynamics in the energy range from 0.7 keV to 5.5 keV. More generally, the presented work has enhanced the understanding of the detector system on the basis of a physical model. The developed experimental and theoretical methods can be applied to any type of array detector which is based on the full depletion of a semiconductor substrate material. (orig.)

  14. Analysis of the charge collection process in solid state X-ray detectors

    International Nuclear Information System (INIS)

    Kimmel, Nils

    2009-01-01

    Physics with X-rays spans from observing large scales in X-ray astronomy down to small scales in material structure analyses with synchrotron radiation. Both fields of research require imaging detectors featuring spectroscopic resolution for X-rays in an energy range of 0.1 keV to 20.0 keV. Originally driven by the need for an imaging spectrometer on ESA's X-ray astronomy satellite mission XMM-Newton, X-ray pnCCDs were developed at the semiconductor laboratory of the Max-Planck-Institute. The pnCCD is a pixel array detector made of silicon. It is sensitive over a wide band from near infrared- over optical- and UV-radiation up to X-rays. This thesis describes the dynamics of signal electrons from the moment after their generation until their collection in the potential minima of the pixel structure. Experimentally, a pinhole array was used to scan the pnCCD surface with high spatial resolution. Numerical simulations were used as a tool for the modeling of the electrical conditions inside the pnCCD. The results predicted by the simulations were compared with the measurements. Both, experiment and simulation, helped to establish a model for the signal charge dynamics in the energy range from 0.7 keV to 5.5 keV. More generally, the presented work has enhanced the understanding of the detector system on the basis of a physical model. The developed experimental and theoretical methods can be applied to any type of array detector which is based on the full depletion of a semiconductor substrate material. (orig.)

  15. Zirconolite glass-ceramics for plutonium immobilization: The effects of processing redox conditions on charge compensation and durability

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yingjie, E-mail: yzx@ansto.gov.au; Gregg, Daniel J.; Kong, Linggen; Jovanovich, Miodrag; Triani, Gerry

    2017-07-15

    Zirconolite glass-ceramic samples doped with plutonium have been prepared via hot isostatic pressing. The effects of processing redox and plutonium loadings on plutonium valences, the presence of cation vacancies, zirconolite phase compositions, microstructures and durability have been investigated. Either tetravalent or trivalent plutonium ions may be incorporated on the Ca-site of CaZrTi{sub 2}O{sub 7} zirconolite with the Ca-site cation vacancies and the incorporation of Al{sup 3+} ions on the Ti-site for charge compensation. Plutonium and gadolinium (as a neutron absorber) are predominantly partitioned in zirconolite phases leading to the formation of chemically durable glass-ceramics suitable for the immobilization of impure plutonium wastes arising from the nuclear fuel cycle. - Highlights: •Plutonium validations of zirconolite glass-ceramics. •Effects of processing redox and plutonium loading. •Zirconolite phase compositions and plutonium valences. •Cation vacancies and chemical durability.

  16. Photoelectric effect in the relativistic domain revealed by the time-reversed process for highly charged uranium ions

    International Nuclear Information System (INIS)

    Stoehlker, T.; Mokler, P.H.; Kozhuharov, C.; Warczak, A.

    1996-10-01

    The photoelectric effect in the near relativistic energy regime of 80 to 350 keV is studied by the time-reversed process in ion-atom collisions, i.e. by the radiative capture of a quasi-free target electron. We review shell and subshell differential photon-angular distribution studies of radiative capture into highly-charged uranium ions. The experimental data are compared with exact relativistic calculations and give detailed insight into both the atomic structure of high-Z few-electron ions and into the fundamental electron-photon interaction process involved. In particular it is shown that the angular-differential measurements provide a unique method to study the magnetic interaction in relativistic electron-photon encoun- (orig.)

  17. Charge density waves as the origin of dip-hump structures in the differential tunneling conductance of cuprates: The case of d-wave superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Gabovich, Alexander M., E-mail: gabovich@iop.kiev.ua; Voitenko, Alexander I., E-mail: voitenko@iop.kiev.ua

    2014-08-15

    Highlights: • d-Wave superconductivity and charge-density waves compete for the Fermi surface. • Charge-density waves induce pseudogaps and peak-dip-hump structures in cuprates. • Tunnel spectra are non-symmetric due to the dielectric order-parameter phase fixation. • Scatter of the dielectric order parameter smears the tunnel spectra peculiarities. - Abstract: Quasiparticle differential current–voltage characteristics (CVCs) G(V) of non-symmetric tunnel junctions between d-wave superconductors with charge-density waves (CDWs) and normal metals were calculated. The dependences G(V) were shown to have a V-like form at small voltages V and low temperatures, and to be asymmetric at larger V owing to the presence of CDW peak in either of the V-branches. The spatial scatter of the dielectric (CDW) order parameter smears the CDW peak into a hump and induces a peak-dip-hump structure (PDHS) typical of CVCs observed for such junctions. At temperatures larger than the superconducting critical one, the PDHS evolves into a pseudogap depression. The results agree well with the scanning tunneling microscopy data for Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ} and YBa{sub 2}Cu{sub 3}O{sub 7−δ}. The results differ substantially from those obtained earlier for CDW s-wave superconductors.

  18. Emotion perception and executive control interact in the salience network during emotionally charged working memory processing

    NARCIS (Netherlands)

    Luo, Y.; Qin, S.; Fernandez, G.S.E.; Zhang, Y.; Klumpers, F.; Li, H.

    2014-01-01

    Processing of emotional stimuli can either hinder or facilitate ongoing working memory (WM); however, the neural basis of these effects remains largely unknown. Here we examined the neural mechanisms of these paradoxical effects by implementing a novel emotional WM task in an fMRI study. Twenty-five

  19. A novel Gaussian process regression model for state-of-health estimation of lithium-ion battery using charging curve

    Science.gov (United States)

    Yang, Duo; Zhang, Xu; Pan, Rui; Wang, Yujie; Chen, Zonghai

    2018-04-01

    The state-of-health (SOH) estimation is always a crucial issue for lithium-ion batteries. In order to provide an accurate and reliable SOH estimation, a novel Gaussian process regression (GPR) model based on charging curve is proposed in this paper. Different from other researches where SOH is commonly estimated by cycle life, in this work four specific parameters extracted from charging curves are used as inputs of the GPR model instead of cycle numbers. These parameters can reflect the battery aging phenomenon from different angles. The grey relational analysis method is applied to analyze the relational grade between selected features and SOH. On the other hand, some adjustments are made in the proposed GPR model. Covariance function design and the similarity measurement of input variables are modified so as to improve the SOH estimate accuracy and adapt to the case of multidimensional input. Several aging data from NASA data repository are used for demonstrating the estimation effect by the proposed method. Results show that the proposed method has high SOH estimation accuracy. Besides, a battery with dynamic discharging profile is used to verify the robustness and reliability of this method.

  20. The exothermic reaction route of a self-heatable conductive ink for rapid processable printed electronics.

    Science.gov (United States)

    Shin, Dong-Youn; Han, Jin Wook; Chun, Sangki

    2014-01-07

    We report the exothermic reaction route and new capability of a self-heatable conductive ink (Ag2O and silver 2,2-dimethyloctanoate) in order to achieve both a low sintering temperature and electrical resistivity within a short sintering time for flexible printed electronics and display appliances. Unlike conventional conductive ink, which requires a costly external heating instrument for rapid sintering, self-heatable conductive ink by itself is capable of generating heat as high as 312 °C when its exothermic reaction is triggered at a temperature of 180 °C. This intensive exothermic reaction is found to result from the recursive reaction of the 2,2-dimethyloctanoate anion, which is thermally dissociated from silver 2,2-dimethyloctanoate, with silver oxide microparticles. Through this recursive reaction, a massive number of silver atoms are supplied from silver oxide microparticles, and the nucleation of silver atoms and the fusion of silver nanoparticles become the major source of heat. This exothermic reaction eventually realizes the electrical resistivity of self-heatable conductive ink as low as 27.5 μΩ cm within just 40 s by combining chemical annealing, which makes it suitable for the roll-to-roll printable electronics such as a flexible touch screen panel.

  1. The Added Value of Conducting Learning Design Meeting to the Online Course Development Process

    Science.gov (United States)

    Shaver, Denise

    2017-01-01

    Do you find it challenging to have discussions with instructors about designing online courses and best practices in teaching? This article will highlight key components to conducting effective Learning Design meetings. It outlines techniques used by this institution that inspires faculty to design coherent courses that lead to meaningful learning…

  2. Survey of Processing Methods for High Strength High Conductivity Wires for High Field Magnet Applications

    Energy Technology Data Exchange (ETDEWEB)

    Han, K.; Embury, J.D.

    1998-10-01

    This paper will deal with the basic concepts of attaining combination of high strength and high conductivity in pure materials, in-situ composites and macrocomposites. It will survey current attainments, and outline where some future developments may lie in developing wire products that are close to the theoretical strength of future magnet applications.

  3. Survey of Processing Methods for High Strength High Conductivity Wires for High Field Magnet Applications

    International Nuclear Information System (INIS)

    Han, K.; Embury, J.D.

    1998-01-01

    This paper will deal with the basic concepts of attaining combination of high strength and high conductivity in pure materials, in-situ composites and macrocomposites. It will survey current attainments, and outline where some future developments may lie in developing wire products that are close to the theoretical strength of future magnet applications

  4. Solution-processed assembly of ultrathin transparent conductive cellulose nanopaper embedding AgNWs

    Science.gov (United States)

    Song, Yuanyuan; Jiang, Yaoquan; Shi, Liyi; Cao, Shaomei; Feng, Xin; Miao, Miao; Fang, Jianhui

    2015-08-01

    Natural biomass based cellulose nanopaper is becoming a promising transparent substrate to supersede traditional petroleum based polymer films in realizing future flexible paper-electronics. Here, ultrathin, highly transparent, outstanding conductive hybrid nanopaper with excellent mechanical flexibility was synthesized by the assembly of nanofibrillated cellulose (NFC) and silver nanowires (AgNWs) using a pressured extrusion paper-making technique. The hybrid nanopaper with a thickness of 4.5 μm has a good combination of transparent conductive performance and mechanical stability using bamboo/hemp NFC and AgNWs cross-linked by hydroxypropylmethyl cellulose (HPMC). The heterogeneous fibrous structure of BNFC/HNFC/AgNWs endows a uniform distribution and an enhanced forward light scattering, resulting in high electrical conductivity and optical transmittance. The hybrid nanopaper with an optimal weight ratio of BNFC/HNFC to AgNWs shows outstanding synergistic properties with a transmittance of 86.41% at 550 nm and a sheet resistance of 1.90 ohm sq-1, equal to the electronic conductivity, which is about 500 S cm-1. The BNFC/HNFC/AgNW hybrid nanopaper maintains a stable electrical conductivity after the peeling test and bending at 135° for 1000 cycles, indicating remarkably strong adhesion and mechanical flexibility. Of importance here is that the high-performance and low-cost hybrid nanopaper shows promising potential for electronics application in solar cells, flexible displays and other high-technology products.Natural biomass based cellulose nanopaper is becoming a promising transparent substrate to supersede traditional petroleum based polymer films in realizing future flexible paper-electronics. Here, ultrathin, highly transparent, outstanding conductive hybrid nanopaper with excellent mechanical flexibility was synthesized by the assembly of nanofibrillated cellulose (NFC) and silver nanowires (AgNWs) using a pressured extrusion paper-making technique. The

  5. Neutrino-induced charged-current reaction rates for r-process nuclei

    CERN Document Server

    Langanke, K

    2001-01-01

    Neutrino-induced reactions play an important role during and after the r-process if it occurs in an environment with extreme neutrino fluxes, as in the neutrino-driven wind model or neutron star mergers. The neutrino reactions can excite the daughter nucleus above the neutron threshold, which is quite low for r-process nuclei. Thus the daughter nucleus will decay by emission of one or several neutrons. We have calculated the relevant total (nu sub e , e sup -) cross sections as well as the partial neutron spallation cross sections for r-process nuclei with neutron numbers N=41-135 and proton numbers Z=21-82. The supernova neutrino spectrum is described by a Fermi-Dirac distribution with various temperature parameters between T=2.8 MeV and T=10 MeV and with the degeneracy parameters alpha=0 and alpha=3. Our calculations of the nuclear response are based on the random phase approximation and consider allowed as well as forbidden transitions.

  6. The exothermic reaction route of a self-heatable conductive ink for rapid processable printed electronics

    Science.gov (United States)

    Shin, Dong-Youn; Han, Jin Wook; Chun, Sangki

    2013-12-01

    We report the exothermic reaction route and new capability of a self-heatable conductive ink (Ag2O and silver 2,2-dimethyloctanoate) in order to achieve both a low sintering temperature and electrical resistivity within a short sintering time for flexible printed electronics and display appliances. Unlike conventional conductive ink, which requires a costly external heating instrument for rapid sintering, self-heatable conductive ink by itself is capable of generating heat as high as 312 °C when its exothermic reaction is triggered at a temperature of 180 °C. This intensive exothermic reaction is found to result from the recursive reaction of the 2,2-dimethyloctanoate anion, which is thermally dissociated from silver 2,2-dimethyloctanoate, with silver oxide microparticles. Through this recursive reaction, a massive number of silver atoms are supplied from silver oxide microparticles, and the nucleation of silver atoms and the fusion of silver nanoparticles become the major source of heat. This exothermic reaction eventually realizes the electrical resistivity of self-heatable conductive ink as low as 27.5 μΩ cm within just 40 s by combining chemical annealing, which makes it suitable for the roll-to-roll printable electronics such as a flexible touch screen panel.We report the exothermic reaction route and new capability of a self-heatable conductive ink (Ag2O and silver 2,2-dimethyloctanoate) in order to achieve both a low sintering temperature and electrical resistivity within a short sintering time for flexible printed electronics and display appliances. Unlike conventional conductive ink, which requires a costly external heating instrument for rapid sintering, self-heatable conductive ink by itself is capable of generating heat as high as 312 °C when its exothermic reaction is triggered at a temperature of 180 °C. This intensive exothermic reaction is found to result from the recursive reaction of the 2,2-dimethyloctanoate anion, which is thermally

  7. Determination of anionic surfactants during wastewater recycling process by ion pair chromatography with suppressed conductivity detection

    Science.gov (United States)

    Levine, L. H.; Judkins, J. E.; Garland, J. L.; Sager, J. C. (Principal Investigator)

    2000-01-01

    A direct approach utilizing ion pairing reversed-phase chromatography coupled with suppressed conductivity detection was developed to monitor biodegradation of anionic surfactants during wastewater recycling through hydroponic plant growth systems and fixed-film bioreactors. Samples of hydroponic nutrient solution and bioreactor effluent with high concentrations (up to 120 mS electrical conductance) of inorganic ions can be analyzed without pretreatment or interference. The presence of non-ionic surfactants did not significantly affect the analysis. Dynamic linear ranges for tested surfactants [Igepon TC-42, ammonium lauryl sulfate, sodium laureth sulfate and sodium alkyl (C10-C16) ether sulfate] were 2 to approximately 500, 1 to approximately 500, 2.5 to approximately 550 and 3.0 to approximately 630 microg/ml, respectively.

  8. Oxidation processes on conducting carbon additives for lithium-ion batteries

    KAUST Repository

    La Mantia, Fabio; Huggins, Robert A.; Cui, Yi

    2012-01-01

    The oxidation processes at the interface between different types of typical carbon additives for lithium-ion batteries and carbonates electrolyte above 5 V versus Li/Li+ were investigated. Depending on the nature and surface area of the carbon

  9. Backward and forward electron emission induced by helium projectiles incident on thin carbon foils: Influence of charge changing processes

    Energy Technology Data Exchange (ETDEWEB)

    Pauly, N. [Universite Libre de Bruxelles, Service de Metrologie Nucleaire (CP 165/84), 50 av. FD Roosevelt, B-1050 Brussels (Belgium)]. E-mail: nipauly@ulb.ac.be; Dubus, A. [Universite Libre de Bruxelles, Service de Metrologie Nucleaire (CP 165/84), 50 av. FD Roosevelt, B-1050 Brussels (Belgium); Roesler, M. [Karl-Pokern-Str. 12, D-12587 Berlin (Germany)

    2007-03-15

    The backward and forward electron emission yields {gamma} {sub B} and {gamma} {sub F} have been calculated by Monte Carlo simulations for helium (He{sup ++}, He{sup +} or He{sup 0}) ions incident on thin amorphous carbon foils with energies around the electronic stopping power maximum (0.2-2 MeV). Besides the direct excitation of target electrons by the incident projectile, we have taken into account the different charge changing processes (He{sup ++} {r_reversible} He{sup +} {r_reversible} He{sup 0}) undergone by the helium ion in the target. We discuss in particular the connection between the electron emission yield {gamma} and the electronic stopping power (dE/dx){sub e}. We compare our results with previously published experimental results.

  10. Kinematic Reconstruction of the Charged Higgs Boson Mass the H+ → t¯b process using a Likelihood Technique

    CERN Document Server

    Villanueva, John Adrian; CERN. Geneva. EP Department

    2017-01-01

    An extension of the Standard Model of particle physics is an introduction of two Higgs doublets to break electroweak symmetry instead of a single Higgs boson. This results to a couple of Higgs bosons, which includes a charged scalar, H±. The H+ is produced as a mediator in a scattering process of a top quark and a bottom quark coming from two gluon. This CERN Summer Student project report studies how to reconstruct the mass of H+ using a novel statistical method based on weighting every combination of the final state products which then corresponds to a weighted average mass per event. Histograms on the invariant mass of the H+ are produced for simulated datasets with different H+ truth mass

  11. Investigation on Interfacial Charge Transfer Process in CdSexTe1-x Alloyed Quantum Dot Sensitized Solar Cells

    International Nuclear Information System (INIS)

    Wei, Huiyun; Wang, Guoshuai; Luo, Yanhong; Li, Dongmei; Meng, Qingbo

    2015-01-01

    Colloidal QDs, typically, alloyed QDs with extending light absorption range, exhibit prospective application on quantum dot-sensitized solar cells (QDSCs). In this work, CdSe 0.8 Te 0.2 alloyed QDs have been employed to assemble QDSCs, and the influence of the photoanode structure and film thickness on the cell performance has been investigated in detail. Further study on the charge transport and interfacial electron transfer processes reveals that with the film thickness increasing, recombination possibility will be remarkably enhanced. By careful control on the balance between the light absorption and carrier recombination, an optimal double-layer photoanode structure with 11.5 μm-thickness transparent and 6 μm-thickness scattering layers can present a power conversion efficiency of 7.55%, which is one of the best records for the sandwiched-type QDSCs

  12. Process modeling of conductivity in nanocomposites based on reticulated polymers and carbon nanotubes

    International Nuclear Information System (INIS)

    Dolgoshej, V.B.; Korskanov, V.V.; Karpova, I.L.; Bardash, L.V.

    2012-01-01

    The dependences of electric conductivities of thermosetting polymer nanocomposites based on epoxy polymer and polycyanurate filled by carbon nanotubes were investigated. Low values of percolation threshold at volume fraction of carbon nanotubes from 0.001 to 0.002 were observed for all samples.Absolute values of the percolation threshold are in good agreement with the results of mathematical modeling. It is established that electrical properties of thermosetting polymer nanocomposites can be characterized in the frame of the same theoretical model despite difference in polymers properties

  13. The Charging Process in a High-speed, Single-cylinder, Four-stroke Engine

    Science.gov (United States)

    Reynolds, Blake; Schecter, Harry; Taylor, E S

    1939-01-01

    Experimental measurements and theoretical calculations were made on an aircraft-type, single cylinder engine, in order to determine the physical nature of the inlet process, especially at high piston speeds. The engine was run at speeds from 1,500 to 2,600 r.p.m. (mean piston speeds of 1,370 to 2,380 feet per minute). Measurements were made of the cylinder pressure during the inlet stroke and of the power output and volumetric efficiency. Measurements were also made, with the engine not running, to determine the resistance and mass of air in the inlet valve port at various crank angles. Results of analysis indicate that mass has an appreciable effect, but friction plays the major part in restricting flow. The observed fact that the volumetric efficiency is considerably less than 100 percent is attributed to thermal effects. An estimate was made of the magnitude of these effects in the present case, and their general nature is discussed.

  14. Procedure versus process: ethical paradigms and the conduct of qualitative research.

    Science.gov (United States)

    Pollock, Kristian

    2012-09-27

    Research is fundamental to improving the quality of health care. The need for regulation of research is clear. However, the bureaucratic complexity of research governance has raised concerns that the regulatory mechanisms intended to protect participants now threaten to undermine or stifle the research enterprise, especially as this relates to sensitive topics and hard to reach groups. Much criticism of research governance has focused on long delays in obtaining ethical approvals, restrictions imposed on study conduct, and the inappropriateness of evaluating qualitative studies within the methodological and risk assessment frameworks applied to biomedical and clinical research. Less attention has been given to the different epistemologies underlying biomedical and qualitative investigation. The bioethical framework underpinning current regulatory structures is fundamentally at odds with the practice of emergent, negotiated micro-ethics required in qualitative research. The complex and shifting nature of real world settings delivers unanticipated ethical issues and (occasionally) genuine dilemmas which go beyond easy or formulaic 'procedural' resolution. This is not to say that qualitative studies are 'unethical' but that their ethical nature can only be safeguarded through the practice of 'micro-ethics' based on the judgement and integrity of researchers in the field. This paper considers the implications of contrasting ethical paradigms for the conduct of qualitative research and the value of 'empirical ethics' as a means of liberating qualitative (and other) research from an outmoded and unduly restrictive research governance framework based on abstract prinicipalism, divorced from real world contexts and values.

  15. 78 FR 73502 - Multistakeholder Process To Develop Consumer Data Privacy Code of Conduct Concerning Facial...

    Science.gov (United States)

    2013-12-06

    ... Blueprint'').\\1\\ The Privacy Blueprint directs NTIA to convene multistakeholder processes to develop legally... services for mobile devices handle personal data.\\3\\ On December 3, 2013, NTIA announced that the goal of... Privacy Bill of Rights. \\1\\ The Privacy Blueprint is available at http://www.whitehouse.gov/sites/default...

  16. Arts-based Research Processes in ECEC: Examples from Preparing and Conducting a Data Collection

    Directory of Open Access Journals (Sweden)

    Torill Vist

    2016-08-01

    Full Text Available In this methodological article, different concepts and possibilities related to how arts-based research processes can contribute in the early phases of ECEC research will be presented and discussed. Despite a setback of art subjects in Norwegian ECEC and early childhood teacher’s education, the field of arts still plays an important role, and is expected to be research-based. Thus, there should be a need for an aesthetical and arts-based dimension in researching ECEC, not only in the subject matter, but also in the method, context, outcome and dissemination. The article focuses on methodological issues in the question development/design phase and the data collection phase, exemplified by the author’s own experiences in arts-based research processes. These processes include participation in dance and music performance as thinking or reflection tools in research, and an arts-based interview method. Some narrative writing processes will also be commented upon. Theoretically, the article primarily leans upon Barone and Eisner’s arts-based research and Irwin and Springgay’s a/r/tography.

  17. Rapid thermal processing of nano-crystalline indium tin oxide transparent conductive oxide coatings on glass by flame impingement technology

    International Nuclear Information System (INIS)

    Schoemaker, S.; Willert-Porada, M.

    2009-01-01

    Indium tin oxide (ITO) is still the best suited material for transparent conductive oxides, when high transmission in the visible range, high infrared reflection or high electrical conductivity is needed. Current approaches on powder-based printable ITO coatings aim at minimum consumption of active coating and low processing costs. The paper describes how fast firing by flame impingement is used for effective sintering of ITO-coatings applied on glass. The present study correlates process parameters of fast firing by flame impingement with optoelectronic properties and changes in the microstructure of suspension derived nano-particulate films. With optimum process parameters the heat treated coatings had a sheet resistance below 0.5 kΩ/ □ combined with a transparency higher than 80%. To characterize the influence of the burner type on the process parameters and the coating functionality, two types of methane/oxygen burner were compared: a diffusion burner and a premixed burner

  18. Understanding charge carrier relaxation processes in terbium arsenide nanoparticles using transient absorption spectroscopy

    Science.gov (United States)

    Vanderhoef, Laura R.

    Erbium arsenide nanoparticles epitaxially grown within III-V semiconductors have been shown to improve the performance of devices for applications ranging from thermoelectrics to THz pulse generation. The small size of rare-earth nanoparticles suggests that interesting electronic properties might emerge as a result of both spatial confinement and surface states. However, ErAs nanoparticles do not exhibit any signs of quantum confinement or an emergent bandgap, and these experimental observations are understood from theory. The incorporation of other rare-earth monopnictide nanoparticles into III-V hosts is a likely path to engineering carrier excitation, relaxation and transport dynamics for optoelectronic device applications. However, the electronic structure of these other rare-earth monopnictide nanoparticles remains poorly understood. The objective of this research is to explore the electronic structure and optical properties of III-V materials containing novel rare-earth monopnictides. We use ultrafast pump-probe spectroscopy to investigate the electronic structure of TbAs nanoparticles in III-V hosts. We start with TbAs:GaAs, which was expected to be similar to ErAs:GaAs. We study the dynamics of carrier relaxation into the TbAs states using optical pump terahertz probe transient absorption spectroscopy. By analyzing how the carrier relaxation rates depend on pump fluence and sample temperature, we conclude that the TbAs states are saturable. Saturable traps suggest the existence of a bandgap for TbAs nanoparticles, in sharp contrast with previous results for ErAs. We then apply the same experimental technique to two samples of TbAs nanoparticles in InGaAs with different concentrations of TbAs. We observe similar relaxation dynamics associated with trap saturation, though the ability to resolve these processes is contingent upon a high enough TbAs concentration in the sample. We have also constructed an optical pump optical probe transient absorption

  19. Processing and electrical conductivity of lanthanum gallate core-shell heterostructures

    Directory of Open Access Journals (Sweden)

    Gomes, Eduarda

    2006-06-01

    Full Text Available The electrical properties of a lanthanum gallate solid electrolyte were modified by selectively doping the grain boundaries with Fe. This was achieved by sandwiching a La0.95Sr0.05Ga0.90Mg0.10O3-δ (LSGM dense pellet between LaFeO3 samples. Annealing at 1550°C in air for several hours promoted Fe diffusion into LSGM via the grain boundaries. Scanning electron microscopy and energy-dispersive spectroscopy analyses showed that iron was located at the grain boundary while the grain bulk preserved the LSGM composition. Impedance spectra obtained at low temperature consist of the two usual bulk and grain boundary contributions. A significant increase in total conductivity was observed for the iron-doped samples, the effect being greater for the grain boundary contribution. The total conductivity measured for the iron-containing material revealed a slight decrease with decreasing oxygen partial pressure, suggesting the onset of p-type electronic conduction. Estimates of the p-type electronic conductivity (σp were obtained by fitting the low temperature impedance spectra to a simple equivalent circuit including one parallel electronic branch. The value for σp in air at 300°C is 3.1×10-6 S/cm and the activation energy is 75.1 kJ/mol between 300 and 400°C.

    Las propiedades elécticas de un electrolito sólido de galato de lantano se han modificado mediante un dopado eléctrico de Fe en borde de grano. Esto se consiguió preparando una estructura de sandwich con una plantilla densa de La0.95Sr0.05Ga0.90Mg0.10O3-δ (LSGM entre las muestras de LaFeO3. Un tratamiento de varias horas a 1550ºC en aire favoreció la difusión de Fe a lo largo de los bordes de grano. Los análisis mediante microscopia electrónica de barrido y espectroscopía de energía dispersada muestran que el hierro se localiza en borde de grano mientras que se preserva la composición de LSGM en el interior de grano. En las muestras dopadas con hierro se observa un aumento de

  20. Procedure versus process: ethical paradigms and the conduct of qualitative research

    Science.gov (United States)

    2012-01-01

    Background Research is fundamental to improving the quality of health care. The need for regulation of research is clear. However, the bureaucratic complexity of research governance has raised concerns that the regulatory mechanisms intended to protect participants now threaten to undermine or stifle the research enterprise, especially as this relates to sensitive topics and hard to reach groups. Discussion Much criticism of research governance has focused on long delays in obtaining ethical approvals, restrictions imposed on study conduct, and the inappropriateness of evaluating qualitative studies within the methodological and risk assessment frameworks applied to biomedical and clinical research. Less attention has been given to the different epistemologies underlying biomedical and qualitative investigation. The bioethical framework underpinning current regulatory structures is fundamentally at odds with the practice of emergent, negotiated micro-ethics required in qualitative research. The complex and shifting nature of real world settings delivers unanticipated ethical issues and (occasionally) genuine dilemmas which go beyond easy or formulaic ‘procedural’ resolution. This is not to say that qualitative studies are ‘unethical’ but that their ethical nature can only be safeguarded through the practice of ‘micro-ethics’ based on the judgement and integrity of researchers in the field. Summary This paper considers the implications of contrasting ethical paradigms for the conduct of qualitative research and the value of ‘empirical ethics’ as a means of liberating qualitative (and other) research from an outmoded and unduly restrictive research governance framework based on abstract prinicipalism, divorced from real world contexts and values. PMID:23016663

  1. Influence of Crucible Thermal Conductivity on Crystal Growth in an Industrial Directional Solidification Process for Silicon Ingots

    Directory of Open Access Journals (Sweden)

    Zaoyang Li

    2016-01-01

    Full Text Available We carried out transient global simulations of heating, melting, growing, annealing, and cooling stages for an industrial directional solidification (DS process for silicon ingots. The crucible thermal conductivity is varied in a reasonable range to investigate its influence on the global heat transfer and silicon crystal growth. It is found that the crucible plays an important role in heat transfer, and therefore its thermal conductivity can influence the crystal growth significantly in the entire DS process. Increasing the crucible thermal conductivity can shorten the time for melting of silicon feedstock and growing of silicon crystal significantly, and therefore large thermal conductivity is helpful in saving both production time and power energy. However, the high temperature gradient in the silicon ingots and the locally concave melt-crystal interface shape for large crucible thermal conductivity indicate that high thermal stress and dislocation propagation are likely to occur during both growing and annealing stages. Based on the numerical simulations, some discussions on designing and choosing the crucible thermal conductivity are presented.

  2. Proposal on How To Conduct a Biopharmaceutical Process Failure Mode and Effect Analysis (FMEA) as a Risk Assessment Tool.

    Science.gov (United States)

    Zimmermann, Hartmut F; Hentschel, Norbert

    2011-01-01

    With the publication of the quality guideline ICH Q9 "Quality Risk Management" by the International Conference on Harmonization, risk management has already become a standard requirement during the life cycle of a pharmaceutical product. Failure mode and effect analysis (FMEA) is a powerful risk analysis tool that has been used for decades in mechanical and electrical industries. However, the adaptation of the FMEA methodology to biopharmaceutical processes brings about some difficulties. The proposal presented here is intended to serve as a brief but nevertheless comprehensive and detailed guideline on how to conduct a biopharmaceutical process FMEA. It includes a detailed 1-to-10-scale FMEA rating table for occurrence, severity, and detectability of failures that has been especially designed for typical biopharmaceutical processes. The application for such a biopharmaceutical process FMEA is widespread. It can be useful whenever a biopharmaceutical manufacturing process is developed or scaled-up, or when it is transferred to a different manufacturing site. It may also be conducted during substantial optimization of an existing process or the development of a second-generation process. According to their resulting risk ratings, process parameters can be ranked for importance and important variables for process development, characterization, or validation can be identified. Health authorities around the world ask pharmaceutical companies to manage risk during development and manufacturing of pharmaceuticals. The so-called failure mode and effect analysis (FMEA) is an established risk analysis tool that has been used for decades in mechanical and electrical industries. However, the adaptation of the FMEA methodology to pharmaceutical processes that use modern biotechnology (biopharmaceutical processes) brings about some difficulties, because those biopharmaceutical processes differ from processes in mechanical and electrical industries. The proposal presented here

  3. 78 FR 9678 - Multi-stakeholder Process To Develop a Voluntary Code of Conduct for Smart Grid Data Privacy

    Science.gov (United States)

    2013-02-11

    ... providing consumer energy use services. DATES: Tuesday, February 26, 2013 (9:30 a.m. to 4:30 p.m., Eastern... Privacy and Promoting Innovation in the Global Digital Economy \\2\\ (Privacy Blueprint). The Privacy Blueprint outlines a multi-stakeholder process for developing voluntary codes of conduct that, if adopted by...

  4. Impaired Neurocognitive Functions Affect Social Learning Processes in Oppositional Defiant Disorder and Conduct Disorder: Implications for Interventions

    Science.gov (United States)

    Matthys, Walter; Vanderschuren, Louk J. M. J.; Schutter, Dennis J. L. G.; Lochman, John E.

    2012-01-01

    In this review, a conceptualization of oppositional defiant (ODD) and conduct disorder (CD) is presented according to which social learning processes in these disorders are affected by neurocognitive dysfunctions. Neurobiological studies in ODD and CD suggest that the ability to make associations between behaviors and negative and positive…

  5. Synthesis of Copper-Based Transparent Conductive Oxides with Delafossite Structure via Sol-Gel Processing

    OpenAIRE

    Götzendörfer, Stefan

    2011-01-01

    Starting off with solubility experiments of possible precursors, the present study reveals the whole development of a sol gel processing route for transparent p type semiconductive thin films with delafossite structure right to the fabrication of functional p-n junctions. The versatile sol formulation could successfully be modified for several oxide compositions, enabling the synthesis of CuAlO2, CuCrO2, CuMnO2, CuFeO2 and more. Although several differences in the sintering behaviour of powde...

  6. Photo-conductive detection of continuous THz waves via manipulated ultrafast process in nanostructures

    Science.gov (United States)

    Moon, Kiwon; Lee, Eui Su; Lee, Il-Min; Park, Dong Woo; Park, Kyung Hyun

    2018-01-01

    Time-domain and frequency-domain terahertz (THz) spectroscopy systems often use materials fabricated with exotic and expensive methods that intentionally introduce defects to meet short carrier lifetime requirements. In this study, we demonstrate the development of a nano-photomixer that meets response speed requirements without using defect-incorporated, low-temperature-grown (LTG) semiconductors. Instead, we utilized a thin InGaAs layer grown on a semi-insulating InP substrate by metal-organic chemical vapor deposition (MOCVD) combined with nano-electrodes to manipulate local ultrafast photo-carrier dynamics via a carefully designed field-enhancement and plasmon effect. The developed nano-structured photomixer can detect continuous-wave THz radiation up to a frequency of 2 THz with a peak carrier collection efficiency of 5%, which is approximately 10 times better than the reference efficiency of 0.4%. The better efficiency results from the high carrier mobility of the MOCVD-grown InGaAs thin layer with the coincidence of near-field and plasmon-field distributions in the nano-structure. Our result not only provides a generally applicable methodology for manipulating ultrafast carrier dynamics by means of nano-photonic techniques to break the trade-off relation between the carrier lifetime and mobility in typical LTG semiconductors but also contributes to mass-producible photo-conductive THz detectors to facilitate the widespread application of THz technology.

  7. High-concentration copper nanoparticles synthesis process for screen-printing conductive paste on flexible substrate

    International Nuclear Information System (INIS)

    Tam, Sze Kee; Ng, Ka Ming

    2015-01-01

    This study presents a method for the synthesis of copper nanoparticles, which are poised to replace silver nanoparticles in some application areas of printed electronics. This method offers three advantages. Firstly, copper loading in the synthesis reaction can be as high as 1 M, offering high productivity in large-scale production. Secondly, the size of the copper nanoparticles can be controlled from 12 to 99 nm. Thirdly, the surface polarity of the particles can be modified. Thus, a tailor-made product can be synthesized. The synthesis of copper nanoparticles coated with various capping agents, including dodecanethiol, lauric acid, nonanoic acid, polyacrylic acid, and polyvinyl pyrrolidone, was demonstrated. The nonanoic acid-coated copper nanoparticles were formulated as a screen-printing conductive paste. The particles were readily dispersed in terpineol, and the paste could be screen printed onto flexible polyester. The electrical resistivity of patterns after a low-temperature (120 °C) sintering treatment was around 5.8 × 10 −5  Ω cm.Graphical Abstract

  8. High-concentration copper nanoparticles synthesis process for screen-printing conductive paste on flexible substrate

    Energy Technology Data Exchange (ETDEWEB)

    Tam, Sze Kee; Ng, Ka Ming, E-mail: kekmng@ust.hk [The Hong Kong University of Science and Technology, Department of Chemical and Biomolecular Engineering (Hong Kong)

    2015-12-15

    This study presents a method for the synthesis of copper nanoparticles, which are poised to replace silver nanoparticles in some application areas of printed electronics. This method offers three advantages. Firstly, copper loading in the synthesis reaction can be as high as 1 M, offering high productivity in large-scale production. Secondly, the size of the copper nanoparticles can be controlled from 12 to 99 nm. Thirdly, the surface polarity of the particles can be modified. Thus, a tailor-made product can be synthesized. The synthesis of copper nanoparticles coated with various capping agents, including dodecanethiol, lauric acid, nonanoic acid, polyacrylic acid, and polyvinyl pyrrolidone, was demonstrated. The nonanoic acid-coated copper nanoparticles were formulated as a screen-printing conductive paste. The particles were readily dispersed in terpineol, and the paste could be screen printed onto flexible polyester. The electrical resistivity of patterns after a low-temperature (120 °C) sintering treatment was around 5.8 × 10{sup −5} Ω cm.Graphical Abstract.

  9. Influence of composition on phase occurrence during charge process of AB5+x Ni-MH negative electrode materials

    International Nuclear Information System (INIS)

    Vivet, S.; Latroche, M.; Chabre, Y.; Joubert, J.-M.; Knosp, B.; Percheron-Guegan, A.

    2005-01-01

    Multi-substituted LaNi 5 -type alloys (AB 5+ x ) are widely used as negative electrode materials in commercial Ni-MH batteries. Cobalt substitution on Ni sites allows to enhance battery cycle life by reducing alloy pulverization induced by hydrogen cycling. This improvement is attributed to the occurrence of a three-phase process (α, β and γ) during electrochemical hydrogen loading. In order to better understand the effect of the composition on the phase occurrence and to reduce the rate of costly cobalt, an in situ neutron diffraction study has been performed at room temperature during electrochemical charge of two different electrode materials MmNi 4.07 Mn 0.63 Al 0.2 M 0.4 with M=Fe and Mn and B/A=5.3. These cobalt free compounds show cycle life comparable to that of commercial materials. The results show that three phases are also observed for these samples. The γ-phase content depends on M and is higher for M=Fe than for M=Mn. These results are related to the improved cycle lives and to the alloy pulverization process

  10. Space Charge Effects

    CERN Document Server

    Ferrario, M.; Palumbo, L.

    2014-12-19

    The space charge forces are those generated directly by the charge distribution, with the inclusion of the image charges and currents due to the interaction of the beam with a perfectly conducting smooth pipe. Space charge forces are responsible for several unwanted phenomena related to beam dynamics, such as energy loss, shift of the synchronous phase and frequency , shift of the betatron frequencies, and instabilities. We will discuss in this lecture the main feature of space charge effects in high-energy storage rings as well as in low-energy linacs and transport lines.

  11. Analysis of Lattice Thermal Conductivity of Si Considering the Effect of Phonon Dispersion on Three-phonon Processes

    Science.gov (United States)

    He, Ping; Li, Zhijian

    2001-03-01

    In this work we present the new relaxation time expressions considering the detailed information of the phonon dispersion. For the three-phonon processes, it is found that only limited types of three-phonon processes are allowed to occur and the attenuation of phonon that conduct heat varies roughly with the fifth power of frequency. By using these expressions, the data of thermal conductivity of bulk silicon is well fitted. And further, the data for thin films of single crystal silicon which cannot be well fitted by the widely used model that proposed by Holland is also well fitted using the new expressions for three-phonon processes and parameters got at the previous step.

  12. Oxidation processes on conducting carbon additives for lithium-ion batteries

    KAUST Repository

    La Mantia, Fabio

    2012-11-21

    The oxidation processes at the interface between different types of typical carbon additives for lithium-ion batteries and carbonates electrolyte above 5 V versus Li/Li+ were investigated. Depending on the nature and surface area of the carbon additive, the irreversible capacity during galvanostatic cycling between 2.75 and 5.25 V versus Li/Li+ could be as high as 700 mAh g-1 (of carbon). In the potential region below 5 V versus Li/Li+, high surface carbon additives also showed irreversible plateaus at about 4.1-4.2 and 4.6 V versus Li/Li+. These plateaus disappeared after thermal treatments at or above 150 °C in inert gas. The influence of the irreversible capacity of carbon additives on the overall performances of positive electrodes was discussed. © 2012 Springer Science+Business Media Dordrecht.

  13. Conducting Polymeric Materials

    DEFF Research Database (Denmark)

    Hvilsted, Søren

    2016-01-01

    The overall objective of this collection is to provide the most recent developments within the various areas of conducting polymeric materials. The conductivity of polymeric materials is caused by electrically charged particles, ions, protons and electrons. Materials in which electrons...

  14. Conducting Polymers

    Indian Academy of Sciences (India)

    would exhibit electronic conductivity, their conductivities (of compressed pellets) were indeed measured by others, and were found to be .... Polyaniline. Polyphenylene. Polypheny lene- vinylene. Table 1. G!NeRAl I ARTICl! structure. Maximum conductivity Stem Stability. Processability. ~. 1.5 x 105. Reacts with Film not n air.

  15. Transparent conductive Ta2O5-codoped ITO thin films prepared by different heating process

    International Nuclear Information System (INIS)

    Zhang, B.; Dong, X.P.; Wu, J.S.; Xu, X.F.

    2008-01-01

    Tantalum-doped indium tin oxide thin films were deposited by a cosputtering technique with an ITO target and a Ta 2 O 5 target. The variations of microstructure, electrical and optical properties with substrate temperature and annealing temperature were investigated in some detail. Ta-doped ITO thin films showed better crystalline structure with different prominent plane orientation by different heating process. ITO:Ta thin films deposited at room temperature showed better optical and electrical properties. Increasing substrate temperature and reasonable annealing temperature could remarkably improve the optical and electrical properties of the films. The variation of carrier concentration had an important influence on near-IR reflection, near-UV absorption and optical bandgap. ITO:Ta thin films showed wider optical bandgap. ITO:Ta thin films under the optimum parameters had a sheet resistance of 10-20 and ohm;/sq and a transmittance of 85% with an optical bandgap of above 4.0 eV. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Conductive subtract development without corrosion for photovoltaic applications on porcelain stoneware according to free electrodes process

    International Nuclear Information System (INIS)

    Reyes-Tolosa, M. D.; Al Aajmi, M.; Orozco-Messana, J.; Donderis, V.; Pascual, M.; Hernandez-Fenollosa, M. A.

    2010-01-01

    In the incipient world of functional industrial ceramics with photovoltaic applications, there is a need to reduce production costs while maximizing the systems useful life. The thin contact layers currently being manufactured are based on vacuum systems with high production costs and major problems of accelerated corrosion in photovoltaic applications. The electroless process produces very even and compact layers with very low costs through chelate-based chemicals. These layers have been formulated in this study with a view to obtaining appropriate electric characteristics for an optimum photoelectric performance in the assemblies. The morphological requirements are previously fitted through a glaze that acts as a barrier layer between the deposited coating and the porcelain tile, applied through tape casting. The characterisation of the metal layers obtained is started by SEM, an AFM and the Hall effect in order to determine the morphology and chemical characteristics required for these contact layers. The electric characterisation also allows their capacity for offering an optimum performance in the assemblies to be assessed. Finally, the performance of these layers with respect to corrosion is assessed in order to complete the assessment of their industrial suitability. (Author) 13 refs.

  17. Charge recombination reduction in dye-sensitized solar cells by means of an electron beam-deposited TiO2 buffer layer between conductive glass and photoelectrode

    International Nuclear Information System (INIS)

    Manca, Michele; Malara, Francesco; Martiradonna, Luigi; De Marco, Luisa; Giannuzzi, Roberto; Cingolani, Roberto; Gigli, Giuseppe

    2010-01-01

    A thin anatase titanium dioxide compact film was deposited by electron beam evaporation as buffer layer between the conductive transparent electrode and the porous TiO 2 -based photoelectrode in dye-sensitized solar cells. The effect of such a buffer layer on the back transfer reaction of electrons to tri-iodide ions in liquid electrolyte-based cells has been studied by means of both electrochemical impedance spectroscopy and open circuit photovoltage decay analysis. The influence of the thickness has been also investigated and an increment in overall quantum conversion efficiency η as high as + 31% with respect to the standard cell - fabricated onto an uncoated conductive glass - has been revealed in the case of a 120 nm thick buffer layer.

  18. THE MEANS OF FORMATION OF MUSIC TEACHER PROFESSIONAL COMPETENCE IN THE PROCESS OF LEARNING OF CONDUCTING AND CHORAL DISCIPLINES

    Directory of Open Access Journals (Sweden)

    Taras Pukhalskyi

    2016-09-01

    Full Text Available The article deals with the means of conducting and choral disciplines, which help the efficiency of training of future music teachers. Taking into consideration training and educational components of formation process of professional competence, the means of conducting and choral disciplines are classified as knowledge and skills integration, the organizational and pedagogical skills development, the communicative skills development, the realization of individual approach, the performing skills development, the educational influence and creative self- efficacy. It was established that the effective implementation of these means in the formation of music teachers’ professional competence is possible in close cooperation of choral disciplines (choir disciplines, choral conducting, choral arrangements, choral class and practical work with the choir is organized.

  19. Framework for assessing the capacity of a health ministry to conduct health policy processes--a case study from Tajikistan.

    Science.gov (United States)

    Mirzoev, Tolib N; Green, Andrew; Van Kalliecharan, Ricky

    2015-01-01

    An adequate capacity of ministries of health (MOH) to develop and implement policies is essential. However, no frameworks were found assessing MOH capacity to conduct health policy processes within developing countries. This paper presents a conceptual framework for assessing MOH capacity to conduct policy processes based on a study from Tajikistan, a former Soviet republic where independence highlighted capacity challenges. The data collection for this qualitative study included in-depth interviews, document reviews and observations of policy events. Framework approach for analysis was used. The conceptual framework was informed by existing literature, guided the data collection and analysis, and was subsequently refined following insights from the study. The Tajik MOH capacity, while gradually improving, remains weak. There is poor recognition of wider contextual influences, ineffective leadership and governance as reflected in centralised decision-making, limited use of evidence, inadequate actors' participation and ineffective use of resources to conduct policy processes. However, the question is whether this is a reflection of lack of MOH ability or evidence of constraining environment or both. The conceptual framework identifies five determinants of robust policy processes, each with specific capacity needs: policy context, MOH leadership and governance, involvement of policy actors, the role of evidence and effective resource use for policy processes. Three underlying considerations are important for applying the capacity to policy processes: the need for clear focus, recognition of capacity levels and elements, and both ability and enabling environment. The proposed framework can be used in assessing and strengthening of the capacity of different policy actors. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Effect of the radio frequency discharge on the dust charging process in a weakly collisional and fully ionized plasma

    Energy Technology Data Exchange (ETDEWEB)

    Motie, Iman [Department of Physics, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Bokaeeyan, Mahyar, E-mail: Mehyar9798@gmail.com [Department of Engineering, University of Applied Science and Technology (UAST)-Mohandesan Center, Mashhad (Iran, Islamic Republic of)

    2015-02-15

    A close analysis of dust charging process in the presence of radio frequency (RF) discharge on low pressure and fully ionized plasma for both weak and strong discharge's electric field is considered. When the electromagnetic waves pass throughout fully ionized plasma, the collision frequency of the plasma is derived. Moreover, the disturbed distribution function of plasma particles in the presence of the RF discharge is obtained. In this article, by using the Krook model, we separate the distribution function in two parts, the Maxwellian part and the perturbed part. The perturbed part of distribution can make an extra current, so-called the accretion rate of electron (or ion) current, towards a dust particle as a function of the average electron-ion collision frequency. It is proven that when the potential of dust grains increases, the accretion rate of electron current experiences an exponential reduction. Furthermore, the accretion rate of electron current for a strong electric field is relatively smaller than that for a weak electric field. The reasons are elaborated.

  1. Charge transfer processes in collisions of Si{sup 4+} ions with He atoms at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, R. [Hitotsubashi Univ., Tokyo (Japan). Computer Center; Watanabe, A. [Dept. of Information Sciences, Ochanomizu Univ., Tokyo (Japan); Sato, H. [Graduate School of Humanities and Sciences, Ochanomizu Univ., Tokyo (Japan); Gu, J.P.; Hirsch, G.; Buenker, R.J. [Wuppertal Univ. (Gesamthochschule) (Germany). Lehrgebiet Theoretische Chemie; Kimura, M. [Graduate School of Science and Engineering, Yamaguchi Univ., Ube (Japan); Stancil, P.C. [Georgia Univ., Athens, GA (United States). Dept. of Physics

    2001-07-01

    Charge transfer in collisions of Si{sup 4+} ions with He atoms below 100 keV/u is studied by using a molecular orbital representation within both the semiclassical and quantal representations. Single transfer reaction Si{sup 4+} + He {yields} Si{sup 3+} + He{sup +} has been studied by a number of theoretical investigations. In addition to the reaction (1), the first semiclassical MOCC calculations are performed for the double transfer channel Si{sup 4+} + He {yields} Si{sup 2+} + He{sup 2+}. Nine molecular states that connect both with single and double electron transfer processes are considered in the present model. Electronic states and corresponding couplings are determined by the multireference single- and double- excitation configuration interaction method. The present cross sections tie well with the earlier calculations of Stancil et al., (1997) at lower energies, but show a rather different magnitude from those of Bacchus-Montabonel and Ceyzeriat, (1998). The present rate constant is found to be significantly different from the experimental finding of Fang and Kwong, (1996) at 4,600 K, and hence does not support the experiment. (orig.)

  2. An intramolecular charge transfer process based fluorescent probe for monitoring subtle pH fluctuation in living cells.

    Science.gov (United States)

    Sun, Mingtai; Du, Libo; Yu, Huan; Zhang, Kui; Liu, Yang; Wang, Suhua

    2017-01-01

    It is crucial to monitor intracellular pH values and their fluctuation since the organelles of cells have different pH distribution. Herein we construct a new small molecule fluorescent probe HBT-O for monitoring the subtle pH values within the scope of neutral to acid in living cells. The probe exhibited good water solubility, a marked turquoise to olivine emission color change in response to pH, and tremendous fluorescence hypochromatic shift of ∼50nm (1718cm -1 ) as well as the increased fluorescence intensity when the pH value changed from neutral to acid. Thus, the probe HBT-O can distinguish the subtle changes in the range of normal pH values from neutral to acid with significant fluorescence changes. These properties can be attributed to the intramolecular charge transfer (ICT) process of the probe upon protonation in buffer solutions at varied pH values. Moreover, the probe was reversible and nearly non-toxic for living cells. Then the probe was successfully used to detect pH fluctuation in living cells by exhibiting different fluorescence colors and intensity. These findings demonstrate that the probe will find useful applications in biology and biomedical research. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Electroweak corrections to charged-current e+e-->4 fermion processes: Technical details and further results

    International Nuclear Information System (INIS)

    Denner, A.; Dittmaier, S.; Roth, M.; Wieders, L.H.

    2005-01-01

    The complete electroweak O(α) corrections have been calculated for the charged-current four-fermion production processes e + e - ->ν τ τ + μ - ν-bar μ , ud-bar μ - ν-bar μ , and ud-bar sc-bar . Here, technical details of this calculation are presented. These include the algebraic reduction of spinor chains to a few standard structures and the consistent implementation of the finite width of the W boson. To this end, a generalization of the complex-mass scheme to the one-loop level is proposed, and the practical application of this method is described. Finally, the effects of the complete O(α) corrections to various differential cross sections of physical interest are discussed and compared to predictions based on the double-pole approximation, revealing that the latter approximation is not sufficient to fully exploit the potential of a future linear collider in an analysis of W-boson pairs at high energies

  4. Associations between Prenatal and Early Childhood Fish and Processed Food Intake, Conduct Problems, and Co-Occurring Difficulties.

    Science.gov (United States)

    Mesirow, Maurissa Sc; Cecil, Charlotte; Maughan, Barbara; Barker, Edward D

    2017-07-01

    Little is known about early life diet as a risk factor for early-onset persistent conduct problems (EOP CP). To investigate this, we used data from the Avon Longitudinal Study of Parents and Children, a UK-based prospective epidemiological birth cohort. 5727 mother-child pairs (49.9 % boys) monitored since pregnancy (delivery date between 1 April, 1991 and 31 December, 1992) reported intake of fish and processed foods at 32 weeks gestation and, for the child, at 3 years; EOP (n = 666) and Low conduct problem (Low CP, n = 5061) trajectories were measured from 4 to 13 years; hyperactivity and emotional difficulties were assessed in childhood (4-10 years) and early adolescence (12-13 years), in addition to potential confounding factors (family adversity, birth complications, income). Compared to Low CP, mothers of EOP children consumed less fish (p processed food (p processed food at 3 years (p processed food (vs. less than one serving/day, p processed food, and low in fish, associate with an EOP CP trajectory and co-occurring difficulties in early adolescence. As small effect size differences were found, further studies are needed to investigate the long-term impact of early unhealthy diet.

  5. Electrically conducting oxide buffer layers on biaxially textured nickel alloy tapes by reel-to-reel MOCVD process

    International Nuclear Information System (INIS)

    Stadel, O; Samoilenkov, S V; Muydinov, R Yu; Schmidt, J; Keune, H; Wahl, G; Gorbenko, O Yu; Korsakov, I E; Melnikov, O V; Kaul, A R

    2006-01-01

    Reel-to-reel MOCVD process for continuous growth of electrically conducting buffer layers on biaxially textured Ni5W tapes has been developed. The new buffer layer architechture is presented: 200 nm (La, Ba) 2 CuO 4 /40 nm (La, Ba)MnO 3 /Ni5W. Constituting layers with high structural quality have been grown on moving tapes (in plane FWHM ≤ 6 0 and out of plane FWHM ≤ 3 0 )

  6. Charge stabilization by reaction center protein immobilized to carbon nanotubes functionalized by amine groups and poly(3-thiophene acetic acid) conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, T.; Magyar, M.; Nagy, L. [Department of Medical Physics and Informatics, University of Szeged, H-6720 Szeged (Hungary); Nemeth, Z.; Hernadi, K. [Department of Applied and Environmental Chemistry, University of Szeged, H-6720 Szeged (Hungary); Endrodi, B.; Bencsik, G.; Visy, Cs. [Department of Physical Chemistry and Materials Science, University of Szeged, H-6720 Szeged (Hungary); Horvath, E.; Magrez, A.; Forro, L. [Institute of Physics of Complex Matter, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland)

    2012-12-15

    A large number of studies have indicated recently that photosynthetic reaction center proteins (RC) bind successfully to nanostructures and their functional activity is largely retained. The major goal of current research is to find the most efficient systems and conditions for the photoelectric energy conversion and for the stability of this bio-nanocomposite. In our studies, we immobilized the RC protein on multiwalled carbon nanotubes (MWNT) through specific chemical binding to amine functional groups and through conducting polymer (poly(3-thiophene acetic acid), PTAA). Both structural (TEM, AFM) and functional (absorption change and conductivity) measurements has shown that RCs could be bound effectively to functionalized CNTs. The kinetics of the light induced absorption change indicated that RCs were still active in the composite and there was an interaction between the protein cofactors and the CNTs. The light generated photocurrent was measured in an electrochemical cell with transparent CNT electrode designed specially for this experiment. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Processing and characterization of a carbon black-filled electrically conductive Nylon-12 nanocomposite produced by selective laser sintering

    International Nuclear Information System (INIS)

    Athreya, Siddharth Ram; Kalaitzidou, Kyriaki; Das, Suman

    2010-01-01

    Selective laser sintering (SLS), a layered manufacturing technique was explored to process an electrically conductive polymer nanocomposite made of Nylon-12 reinforced with 4 wt% of carbon black. SLS process parameters were optimized in order to maximize the flexural modulus. The porosity and morphology were studied using optical microscopy and scanning electron microscopy (SEM). The crystalline state was characterized using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The electrical conductivity was determined using the four probe technique. Results indicate that carbon black-filled Nylon-12 nanocomposites can be successfully made by SLS. Maximum flexural modulus values of 1750 MPa and 1450 MPa were achieved for the neat polymer and the nanocomposite, respectively. A reduction in the flexural modulus of the nanocomposite is likely due to the formation of a segregated structure in the nanocomposite and a weak polymer-filler interface. The optimized neat polymer and the nanocomposites had average densities of around 97% and 96% relative to full density, respectively. The electrical conductivity of the nanocomposite was approximately 1 x 10 -4 S/cm, which is five orders of magnitude higher than that of the neat polymer processed by SLS, and indicates that the onset of percolation behavior occurs below the 4 wt% loading of carbon black.

  8. Conductivity equations of protons transporting through 2D crystals obtained with the rate process theory and free volume concept

    Science.gov (United States)

    Hao, Tian; Xu, Yuanze; Hao, Ting

    2018-04-01

    The Eyring's rate process theory and free volume concept are employed to treat protons (or other particles) transporting through a 2D (two dimensional) crystal like graphene and hexagonal boron nitride. The protons are assumed to be activated first in order to participate conduction and the conduction rate is dependent on how much free volume available in the system. The obtained proton conductivity equations show that only the number of conduction protons, proton size and packing structure, and the energy barrier associated with 2D crystals are critical; the quantization conductance is unexpectedly predicted with a simple Arrhenius type temperature dependence. The predictions agree well with experimental observations and clear out many puzzles like much smaller energy barrier determined from experiments than from the density function calculations and isotope separation rate independent of the energy barrier of 2D crystals, etc. Our work may deepen our understandings on how protons transport through a membrane and has direct implications on hydrogen related technology and proton involved bioprocesses.

  9. Highly Conductive Cu 2– x S Nanoparticle Films through Room-Temperature Processing and an Order of Magnitude Enhancement of Conductivity via Electrophoretic Deposition

    KAUST Repository

    Otelaja, Obafemi O.; Ha, Don-Hyung; Ly, Tiffany; Zhang, Haitao; Robinson, Richard D.

    2014-01-01

    © 2014 American Chemical Society. A facile room-temperature method for assembling colloidal copper sulfide (Cu2-xS) nanoparticles into highly electrically conducting films is presented. Ammonium sulfide is utilized for connecting the nanoparticles

  10. Relation of Thermal Conductivity with Process Induced Anisotropic Void Systems in EB-PVD PYSZ Thermal Barrier Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Renteria, A. Flores; Saruhan-Brings, B.; Ilavsky, J.

    2008-03-03

    Thermal barrier coatings (TBCs) deposited by Electron-beam physical deposition (EB-PVD) protect the turbine blades situated at the high pressure sector of the aircraft and stationary turbines. It is an important task to uphold low thermal conductivity in TBCs during long-term service at elevated temperatures. One of the most promising methods to fulfil this task is to optimize the properties of PYSZ-based TBC by tailoring its microstructure. Thermal conductivity of the EB-PVD produced PYSZ TBCs is influenced mainly by the size, shape, orientation and volume of the various types of porosity present in the coatings. These pores can be classified as open (inter-columnar and between feather arms gaps) and closed (intra-columnar pores). Since such pores are located within the three-dimensionally deposited columns and enclose large differences in their sizes, shapes, distribution and anisotropy, the accessibility for their characterization is very complex and requires the use of sophisticated methods. In this work, three different EB-PVD TBC microstructures were manufactured by varying the process parameters, yielding various characteristics of their pores. The corresponding thermal conductivities in as-coated state and after ageing at 11000C/1h and 100h were measured via Laser Flash Analysis Method (LFA). The pore characteristics and their individual effect on the thermal conductivity are analysed by USAXS which is supported by subsequent modelling and LFA methods, respectively. Evident differences in the thermal conductivity values of each microstructure were found in as-coated and aged conditions. In summary, broader columns introduce higher values in thermal conductivity. In general, thermal conductivity increases after ageing for all three investigated microstructures, although those with initial smaller pore surface area show smaller changes.

  11. Relation of thermal conductivity with process induced anisotropic void system in EB-PVD PYSZ thermal barrier coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Renteria, A. F.; Saruhan, B.; Ilavsky, J.; German Aerospace Center

    2007-01-01

    Thermal barrier coatings (TBCs) deposited by Electron-beam physical deposition (EB-PVD) protect the turbine blades situated at the high pressure sector of the aircraft and stationary turbines. It is an important task to uphold low thermal conductivity in TBCs during long-term service at elevated temperatures. One of the most promising methods to fulfil this task is to optimize the properties of PYSZ-based ,TBC by tailoring its microstructure. Thermal conductivity of the EB-PVD produced PYSZ TBCs is influenced mainly by the size, shape, orientation and volume of the various types of porosity present in the coatings. These pores can be classified as open (inter-columnar and between feather arms gaps) and closed (intra-columnar pores). Since such pores are located within the three-dimensionally deposited columns and enclose large differences in their sizes, shapes, distribution and anisotropy, the accessibility for their characterization is very complex and requires the use of sophisticated methods. In this work, three different EB-PVD TBC microstructures were manufactured by varying the process parameters, yielding various characteristics of their pores. The corresponding thermal conductivities in as-coated state and after ageing at 1100C/1h and 100h were measured via Laser Flash Analysis Method (LFA). The pore characteristics and their individual effect on the thermal conductivity are analysed by USAXS which is supported by subsequent modelling and LFA methods, respectively. Evident differences in the thermal conductivity values of each microstructure were found in as-coated and aged conditions. In summary, broader columns introduce higher values in thermal conductivity. In general, thermal conductivity increases after ageing for all three investigated microstructures, although those with initial smaller pore surface area show smaller changes.

  12. Exciton-dissociation and charge-recombination processes in pentacene/C60 solar cells: theoretical insight into the impact of interface geometry.

    Science.gov (United States)

    Yi, Yuanping; Coropceanu, Veaceslav; Brédas, Jean-Luc

    2009-11-04

    The exciton-dissociation and charge-recombination processes in organic solar cells based on pentacene/C(60) heterojunctions are investigated by means of quantum-mechanical calculations. The electronic couplings and the rates of exciton dissociation and charge recombination have been evaluated for several geometrical configurations of the pentacene/C(60) complex, which are relevant to bilayer and bulk heterojunctions. The results suggest that, irrespective of the actual pentacene-fullerene orientation, both pentacene-based and C(60)-based excitons are able to dissociate efficiently. Also, in the case of parallel configurations of the molecules at the pentacene/C(60) interface, the decay of the lowest charge-transfer state to the ground state is calculated to be very fast; as a result, it can compete with the dissociation process into mobile charge carriers. Since parallel configurations are expected to be found more frequently in bulk heterojunctions than in bilayer heterojunctions, the performance of pentacene/C(60) bulk-heterojunction solar cells is likely to be more affected by charge recombination than that of bilayer devices.

  13. Exciton-Dissociation and Charge-Recombination Processes in Pentacene/C 60 Solar Cells: Theoretical Insight into the Impact of Interface Geometry

    KAUST Repository

    Yi, Yuanping

    2009-11-04

    The exciton-dissociation and charge-recombination processes in organic solar cells based on pentacene/C60 heterojunctions are investigated by means of quantum-mechanical calculations. The electronic couplings and the rates of exciton dissociation and charge recombination have been evaluated for several geometrical configurations of the pentacene/C60 complex, which are relevant to bilayer and bulk heterojunctions. The results suggest that, irrespective of the actual pentacene-fullerene orientation, both pentacene-based and C60-based excitons are able to dissociate efficiently. Also, in the case of parallel configurations of the molecules at the pentacene/C60 interface, the decay of the lowest charge-transfer state to the ground state is calculated to be very fast; as a result, it can compete with the dissociation process into mobile charge carriers. Since parallel configurations are expected to be found more frequently in bulk heterojunctions than in bilayer heterojunctions, the performance of pentacene/C60 bulk-heterojunction solar cells is likely to be more affected by charge recombination than that of bilayer devices. © 2009 American Chemical Society.

  14. Electron-emission processes in highly charged Ar and Xe ions impinging on highly ordered pyrolytic graphite at energies just above the kinetic threshold

    NARCIS (Netherlands)

    Bodewits, E.; Hoekstra, R.; Dobes, K.; Aumayr, F.

    2014-01-01

    At keV energies, many electronic processes contribute to the emission of secondary electrons in the interaction of highly charged ions on surfaces. To unravel contributions resulting from isolated hollow atoms in front of the surface or embedded in the electron gas of the target, heavy highly

  15. Specific effect of the linear charge density of the acid polysaccharide on thermal aggregation/ disaggregation processes in complex carrageenan/lysozyme systems

    NARCIS (Netherlands)

    Antonov, Y.; Zhuravleva, I.; Cardinaels, R.M.; Moldenaers, P.

    2017-01-01

    We study thermal aggregation and disaggregation processes in complex carrageenan/lysozyme systems with a different linear charge density of the sulphated polysaccharide. To this end, we determine the temperature dependency of the turbidity and the intensity size distribution functions in complex

  16. A salt water battery with high stability and charging rates made from solution processed conjugated polymers with polar side chains

    KAUST Repository

    Moia, Davide; Giovannitti, Alexander; Szumska, Anna A.; Schnurr, Martin; Rezasoltani, Elham; Maria, Iuliana P.; Barnes, Piers R. F.; McCulloch, Iain; Nelson, Jenny

    2017-01-01

    conjugated polymer backbones, allowed the films to maintain constant capacity at high charge and discharge rates (>1000 C-rate). The electrodes also show good stability during electrochemical cycling (less than 30% decrease in capacity over >1000 cycles) and an output voltage up to 1.4 V. The performance of these semiconducting polymers with polar side-chains demonstrates the potential of this material class for fast-charging, water based electrochemical energy storage devices.

  17. Mechanisms of electrical conductivity in olivine

    International Nuclear Information System (INIS)

    Schock, R.N.; Duba, A.G.; Shankland, T.J.

    1984-01-01

    Data on the electrical conductivity and the thermoelectric effect in single crystals indicate that the charge conduction mechanism in pure magnesium forsterite is electrons. The concentration of electrons can be varied by controlling the number of oxygen vacancies through manipulation of the oxygen pressure. For iron bearing olivine, the conduction mechanism is by electron holes localized on an iron ion. Since iron strongly affects the creep process as well, oxidation of iron is probably accompanied by the production of magnesium vacancies. 15 references

  18. Investigations of solution-processed charge generation unit with low concentration of small molecule doped in p-type/HAT-CN{sub 6} for tandem OLED

    Energy Technology Data Exchange (ETDEWEB)

    Talik, N.A., E-mail: azrina_talik@hotmail.com [Low Dimensional Material Research Centre (LDMRC), Physics Dept., Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Yeoh, K.H. [Low Dimensional Material Research Centre (LDMRC), Physics Dept., Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Centre for Photonics and Advanced Materials Research (CPR), Lee Kong Chian Faculty of Engineering and Science, University Tunku Abdul Rahman, 43000 Kajang, Selangor (Malaysia); Ng, C.Y.B. [Low Dimensional Material Research Centre (LDMRC), Physics Dept., Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Tan, C.Y. [Centre of Advanced Manufacturing & Material Processing (AMMP), Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Yap, B.K., E-mail: kbyap@uniten.edu.my [Centre of Microelectronic and Nano Engineering (CeMNE), College of Engineering, Universiti Tenaga Nasional, 43000 Kajang, Selangor (Malaysia)

    2016-01-15

    We investigated the charge generation and injection mechanism in solution processed charge generation unit (CGU) used in our high performance tandem organic light emitting diode (OLED) via capacitance–voltage (C–V) and current density–voltage (J–V) measurements. By doping 2 wt% of small molecule 1,1-bis-(4-bis(4-tolyl)-aminophenyl) cyclohexene (TAPC) into Poly (N-vinylcarbazole) (PVK) as p-type layer of the CGU, we obtained more than two folds improvement in the tandem device efficiency compared to single device. The performance improvement of the TAPC doped CGU could be attributed to low built-in potential, large vacuum level shift as well as high charge density for efficient charge generation. - Highlights: • Charge-generation and injection mechanism in CGU for tandem OLED is investigated. • Small molecule, TAPC doped in p-type/HAT-CN{sub 6} has been used for tandem OLED. • The improvement attributes to the lower V{sub bi} and larger ΔV{sub L} in doped layer. • Narrower W and high carrier density also contribute to efficiency improvement.

  19. Investigations of solution-processed charge generation unit with low concentration of small molecule doped in p-type/HAT-CN6 for tandem OLED

    International Nuclear Information System (INIS)

    Talik, N.A.; Yeoh, K.H.; Ng, C.Y.B.; Tan, C.Y.; Yap, B.K.

    2016-01-01

    We investigated the charge generation and injection mechanism in solution processed charge generation unit (CGU) used in our high performance tandem organic light emitting diode (OLED) via capacitance–voltage (C–V) and current density–voltage (J–V) measurements. By doping 2 wt% of small molecule 1,1-bis-(4-bis(4-tolyl)-aminophenyl) cyclohexene (TAPC) into Poly (N-vinylcarbazole) (PVK) as p-type layer of the CGU, we obtained more than two folds improvement in the tandem device efficiency compared to single device. The performance improvement of the TAPC doped CGU could be attributed to low built-in potential, large vacuum level shift as well as high charge density for efficient charge generation. - Highlights: • Charge-generation and injection mechanism in CGU for tandem OLED is investigated. • Small molecule, TAPC doped in p-type/HAT-CN 6 has been used for tandem OLED. • The improvement attributes to the lower V bi and larger ΔV L in doped layer. • Narrower W and high carrier density also contribute to efficiency improvement.

  20. Charging and Screening in Nonpolar Solutions of Nonionizable Surfactants

    Science.gov (United States)

    Behrens, Sven

    2010-03-01

    Nonpolar liquids do not easily accommodate electric charges, but surfactant additives are often found to dramatically increase the solution conductivity and promote surface charging of suspended colloid particles. Such surfactant-mediated electrostatic effects have been associated with equilibrium charge fluctuations among reverse surfactant micelles and in some cases with the statistically rare ionization of individual surfactant molecules. Here we present experimental evidence that even surfactants without any ionizable group can mediate charging and charge screening in nonpolar oils, and that they can do so at surfactant concentrations well below the critical micelle concentration (cmc). Precision conductometry, light scattering, and Karl-Fischer titration of sorbitan oleate solutions in hexane, paired with electrophoretic mobility measurements on suspended polymer particles, reveal a distinctly electrostatic action of the surfactant. We interpret our observations in terms of a charge fluctuation model and argue that the observed charging processes are likely facilitated, but not limited, by the presence of ionizable impurities.

  1. Real-time electrical impedimetric monitoring of blood coagulation process under temperature and hematocrit variations conducted in a microfluidic chip.

    Directory of Open Access Journals (Sweden)

    Kin Fong Lei

    Full Text Available Blood coagulation is an extremely complicated and dynamic physiological process. Monitoring of blood coagulation is essential to predict the risk of hemorrhage and thrombosis during cardiac surgical procedures. In this study, a high throughput microfluidic chip has been developed for the investigation of the blood coagulation process under temperature and hematocrit variations. Electrical impedance of the whole blood was continuously recorded by on-chip electrodes in contact with the blood sample during coagulation. Analysis of the impedance change of the blood was conducted to investigate the characteristics of blood coagulation process and the starting time of blood coagulation was defined. The study of blood coagulation time under temperature and hematocrit variations was shown a good agreement with results in the previous clinical reports. The electrical impedance measurement for the definition of blood coagulation process provides a fast and easy measurement technique. The microfluidic chip was shown to be a sensitive and promising device for monitoring blood coagulation process even in a variety of conditions. It is found valuable for the development of point-of-care coagulation testing devices that utilizes whole blood sample in microliter quantity.

  2. Modeling conductive heat transfer during high-pressure thawing processes: determination of latent heat as a function of pressure.

    Science.gov (United States)

    Denys, S; Van Loey, A M; Hendrickx, M E

    2000-01-01

    A numerical heat transfer model for predicting product temperature profiles during high-pressure thawing processes was recently proposed by the authors. In the present work, the predictive capacity of the model was considerably improved by taking into account the pressure dependence of the latent heat of the product that was used (Tylose). The effect of pressure on the latent heat of Tylose was experimentally determined by a series of freezing experiments conducted at different pressure levels. By combining a numerical heat transfer model for freezing processes with a least sum of squares optimization procedure, the corresponding latent heat at each pressure level was estimated, and the obtained pressure relation was incorporated in the original high-pressure thawing model. Excellent agreement with the experimental temperature profiles for both high-pressure freezing and thawing was observed.

  3. Is optimality in stomatal conductance an endogenous process or an emergent property arising from interactions with the environment?

    Science.gov (United States)

    Resco de Dios, Victor; Gessler, Arthur; Ferrio, Juan Pedro; Bahn, Michael; Milcu, Alexandru; Tissue, David; Voltas, Jordi; Roy, Jacques

    2016-04-01

    Plants are sessile and poikilothermic organisms that need to respond and adjust promptly to an ever-changing environment. Over a single 24 h period, a plant may experience the same level of variation in radiation as in its entire life-time and, in some climates, the oscillation in day-night temperature and vapor pressure deficit might be of similar magnitude to that experienced across a full year. Plants need to maintain a positive C balance without depleting soil water reserves in the face of such a diverse environment, and feedbacks between assimilation (A) and water losses (E) are thought to have evolved to optimize stomatal conductance (gs). In short, the optimal conductance hypothesis proposes that cross-talks between A and stomatal conductance gs lead to a constant marginal water use (λ) during a day, such that A is maximized and E minimized. The biological mechanism by which biochemical processes would feedback gs remains unknown, but multiple studies have shown empirical support for this hypothesis, leading to its current consideration of theory by many. Here we test whether optimal stomatal conductance is an endogenous property, that is, driven solely by factors internal to the plant, and in the absence of environmental fluctuations. After 5 days of entrainment, where monoculture canopies of bean and of cotton were subjected to the average environmental conditions of an August sunny day in Montpellier (at the CNRS European Ecotron, FR), we kept temperature, relative humidity and photosynthetically active radiation constant for 48 h at the values observed at noon. During this period, we monitored leaf gas exchange continuously every two minutes, and canopy gas exchange every 15 minutes. We observed a periodic oscillation in λ, showing a 24 h period, and consistent with a circadian regulation of water use efficiency. Hourly variations in λ could thus not be explained by the optimal stomatal hypothesis. Moreover, the pattern of variation (of maximal water

  4. A Review of Electrospun Conductive Polyaniline Based Nanofiber Composites and Blends: Processing Features, Applications, and Future Directions

    Directory of Open Access Journals (Sweden)

    Saiful Izwan Abd Razak

    2015-01-01

    Full Text Available Electrospun polymer nanofibers with high surface area to volume ratio and tunable characteristic are formed through the application of strong electrostatic field. Electrospinning has been identified as a straight forward and viable technique to produce nanofibers from polymer solution as their initial precursor. These nanofiber materials have attracted attention of researchers due to their enhanced and exceptional nanostructural characteristics. Electrospun polyaniline (PANI based nanofiber is one of the important new materials for the rapidly growing technology development such as nanofiber based sensor devices, conductive tissue engineering scaffold materials, supercapacitors, and flexible solar cells applications. PANI however is relatively hard to process compared to that of other conventional polymers and plastics. The processing of PANI is daunting, mainly due to its rigid backbone which is related to its high level of conjugation. The challenges faced in the electrospinning processing of neat PANI have alternatively led to the development of the electrospun PANI based composites and blends. A review on the research activities of the electrospinning processing of the PANI based nanofibers, the potential prospect in various fields, and their future direction are presented.

  5. Charge transport model in nanodielectric composites based on quantum tunneling mechanism and dual-level traps

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guochang; Chen, George, E-mail: gc@ecs.soton.ac.uk, E-mail: sli@mail.xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); School of Electronic and Computer Science, University of Southampton, Southampton SO17 1BJ (United Kingdom); Li, Shengtao, E-mail: gc@ecs.soton.ac.uk, E-mail: sli@mail.xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China)

    2016-08-08

    Charge transport properties in nanodielectrics present different tendencies for different loading concentrations. The exact mechanisms that are responsible for charge transport in nanodielectrics are not detailed, especially for high loading concentration. A charge transport model in nanodielectrics has been proposed based on quantum tunneling mechanism and dual-level traps. In the model, the thermally assisted hopping (TAH) process for the shallow traps and the tunnelling process for the deep traps are considered. For different loading concentrations, the dominant charge transport mechanisms are different. The quantum tunneling mechanism plays a major role in determining the charge conduction in nanodielectrics with high loading concentrations. While for low loading concentrations, the thermal hopping mechanism will dominate the charge conduction process. The model can explain the observed conductivity property in nanodielectrics with different loading concentrations.

  6. Effects of laser-induced recovery process on conductive property of SnO2:F thin films

    International Nuclear Information System (INIS)

    Chen, Ming-Fei; Lin, Keh-moh; Ho, Yu-Sen

    2011-01-01

    In this study, we developed a laser annealing process to enhance the electrical properties of SnO 2 :F (FTO) films. It is already known that in contrast to indium oxides or zinc oxides, the carrier mobility of FTO films is relatively lower. Thus, improving the mobility is a direct way to enhance the conductivity of FTO films. Furthermore, improving the crystal quality of the thin films is in turn a direct way to enhance the mobility effectively. Contrary to the high working temperatures of traditional annealing processes, the laser annealing process, with its focusing character, enables us to modify the crystal quality of oxide films on substrates with low-melting points. Using a self-built laser system, which consists of a Nd:YAG solid-state laser with a wavelength of 1064 nm and a beam shaper lens, we carried out a series of experiments to achieve the optimal laser annealing process. Hall, SEM, and XRD measurements were used to characterize the opto-electrical as well as the structural properties. As experimental results show, the tin oxide crystallites recovered well during the laser annealing process. By using a suitable beam profile and a proper laser intensity, the film resistivity was reduced from 7.19 ± 0.55 x 10 -3 Ω cm to 6.70 ± 0.20 x 10 -3 Ω cm while the carrier mobility was enhanced from 11.18 ± 0.29 cm 2 /V s to 11.71 ± 0.34 cm 2 /V s.

  7. Effect of different photoanode nanostructures on the initial charge separation and electron injection process in dye sensitized solar cells: A photophysical study with indoline dyes

    Energy Technology Data Exchange (ETDEWEB)

    Idígoras, Jesús [Nanostructured Solar Cells Group, Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, Ctra. Utrera, km 1, ES-41013 Seville (Spain); Sobuś, Jan [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614 Poznań (Poland); Jancelewicz, Mariusz [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Azaceta, Eneko; Tena-Zaera, Ramon [Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, Paseo Miramón 196, Donostia-San Sebastián, 20009 (Spain); Anta, Juan A. [Nanostructured Solar Cells Group, Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, Ctra. Utrera, km 1, ES-41013 Seville (Spain); Ziółek, Marcin, E-mail: marziol@amu.edu.pl [Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614 Poznań (Poland)

    2016-02-15

    Ultrafast and fast charge separation processes were investigated for complete cells based on several ZnO-based photoanode nanostructures and standard TiO{sub 2} nanoparticle layers sensitized with the indoline dye coded D358. Different ZnO morphologies (nanoparticles, nanowires, mesoporous), synthesis methods (hydrothermal, gas-phase, electrodeposition in aqueous media and ionic liquid media) and coatings (ZnO–ZnO core–shell, ZnO–TiO{sub 2} core–shell) were measured by transient absorption techniques in the time scale from 100 fs to 100 μs and in the visible and near-infrared spectral range. All of ZnO cells show worse electron injection yields with respect to those with standard TiO{sub 2} material. Lower refractive index of ZnO than that of TiO{sub 2} is suggested to be an additional factor, not considered so far, that can decrease the performance of ZnO-based solar cells. Evidence of the participation of the excited charge transfer state of the dye in the charge separation process is provided here. The lifetime of this state in fully working devices extends from several ps to several tens of ps, which is much longer than the typically postulated electron injection times in all-organic dye-sensitized solar cells. The results here provided, comprising a wide variety of morphologies and preparation methods, point to the universality of the poor performance of ZnO as photoanode material with respect to standard TiO{sub 2}. - Highlights: • Wide variety of morphologies and preparation methods has been checked for ZnO cells. • All ZnO cells work worse than TiO{sub 2} ones. • Effective refractive index might be an additional factor in solar cell performance. • Excited charge transfer state of indoline dyes participates in the charge separation.

  8. Using in-situ polymerization of conductive polymers to enhance the electrical properties of solution-processed carbon nanotube films and fibers.

    Science.gov (United States)

    Allen, Ranulfo; Pan, Lijia; Fuller, Gerald G; Bao, Zhenan

    2014-07-09

    Single-walled carbon nanotubes/polymer composites typically have limited conductivity due to a low concentration of nanotubes and the insulating nature of the polymers used. Here we combined a method to align carbon nanotubes with in-situ polymerization of conductive polymer to form composite films and fibers. Use of the conducting polymer raised the conductivity of the films by 2 orders of magnitude. On the other hand, CNT fiber formation was made possible with in-situ polymerization to provide more mechanical support to the CNTs from the formed conducting polymer. The carbon nanotube/conductive polymer composite films and fibers had conductivities of 3300 and 170 S/cm, respectively. The relatively high conductivities were attributed to the polymerization process, which doped both the SWNTs and the polymer. In-situ polymerization can be a promising solution-processable method to enhance the conductivity of carbon nanotube films and fibers.

  9. Transparent conducting oxide nanotubes

    Science.gov (United States)

    Alivov, Yahya; Singh, Vivek; Ding, Yuchen; Nagpal, Prashant

    2014-09-01

    Thin film or porous membranes made of hollow, transparent, conducting oxide (TCO) nanotubes, with high chemical stability, functionalized surfaces and large surface areas, can provide an excellent platform for a wide variety of nanostructured photovoltaic, photodetector, photoelectrochemical and photocatalytic devices. While large-bandgap oxide semiconductors offer transparency for incident light (below their nominal bandgap), their low carrier concentration and poor conductivity makes them unsuitable for charge conduction. Moreover, materials with high conductivity have nominally low bandgaps and hence poor light transmittance. Here, we demonstrate thin films and membranes made from TiO2 nanotubes heavily-doped with shallow Niobium (Nb) donors (up to 10%, without phase segregation), using a modified electrochemical anodization process, to fabricate transparent conducting hollow nanotubes. Temperature dependent current-voltage characteristics revealed that TiO2 TCO nanotubes, doped with 10% Nb, show metal-like behavior with resistivity decreasing from 6.5 × 10-4 Ωcm at T = 300 K (compared to 6.5 × 10-1 Ωcm for nominally undoped nanotubes) to 2.2 × 10-4 Ωcm at T = 20 K. Optical properties, studied by reflectance measurements, showed light transmittance up to 90%, within wavelength range 400 nm-1000 nm. Nb doping also improves the field emission properties of TCO nanotubes demonstrating an order of magnitude increase in field-emitter current, compared to undoped samples.

  10. Influence of both ion bombardment and chemical treatment processes on the electrical conductivity of PVC/poly aniline composites

    International Nuclear Information System (INIS)

    Gad, E.A.M.; Ashour, A.H.; Abdel-Hamid, H.M.; Sayed, W.M.

    1999-01-01

    In this article the changes in the electrical conductivity of PVC/poly aniline composites, as temperature consecutively increases, have been measured. The measurement were taken with correspondence to a control series of the composites under two processes:A. Composite samples bombarded with Ar + ions with fluence 2.44 x 10 13 beam ions /cm 2 ., sec 4 of 4 ke V beam energy where argon atoms can induce defects in the surface layer take place. Composite samples treated chemically with concentrated H 2 SO 4 as dopant which reacts with nitrogen atom in aniline. The measurements were also, done with the composites as the ratio of poly(aniline) stepped upward

  11. Improving the conductance of ZnO thin film doping with Ti by using a cathodic vacuum arc deposition process

    International Nuclear Information System (INIS)

    Wu, Chun-Sen; Lin, Bor-Tsuen; Jean, Ming-Der

    2011-01-01

    The Ti-doped ZnO films compared to un-doped ZnO films were deposited onto Corning XG glass substrates by using a cathodic vacuum arc deposition process in a mixture of oxygen and argon gases. The structural, electrical and optical properties of un-doped and Ti-doped ZnO films have been investigated. When the Ti target power is about 750 W, the incorporation of titanium atoms into zinc oxide films is obviously effective. Additionally, the resistivity of un-doped ZnO films is high and reduces to a value of 3.48 x 10 -3 Ω-cm when Ti is incorporated. The Ti doped in the ZnO films gave rise to the improvement of the conductivity of the films obviously. The Ti-doped ZnO films have > 85% transmittance in a range of 400-700 nm.

  12. Solution-Processable transparent conducting electrodes via the self-assembly of silver nanowires for organic photovoltaic devices.

    Science.gov (United States)

    Tugba Camic, B; Jeong Shin, Hee; Hasan Aslan, M; Basarir, Fevzihan; Choi, Hyosung

    2018-02-15

    Solution-processed transparent conducting electrodes (TCEs) were fabricated via the self-assembly deposition of silver nanowires (Ag NWs). Glass substrates modified with (3-aminopropyl)triethoxysilane (APTES) and (3-mercaptopropyl)trimethoxysilane (MPTES) were coated with Ag NWs for various deposition times, leading to three different Ag NWs samples (APTES-Ag NWs (PVP), MPTES-Ag NWs (PVP), and APTES-Ag NWs (COOH)). Controlling the deposition time produced Ag NWs monolayer thin films with different optical transmittance and sheet resistance. Post-annealing treatment improved their electrical conductivity. The Ag NWs films were successfully characterized using UV-Vis spectroscopy, field emission scanning electron microscopy, optical microscopy and four-point probe. Three Ag NWs films exhibited low sheet resistance of 4-19Ω/sq and high optical transmittance of 65-81% (at 550nm), which are comparable to those of commercial ITO electrode. We fabricated an organic photovoltaic device by using Ag NWs as the anode instead of ITO electrode, and optimized device with Ag NWs exhibited power conversion efficiency of 1.72%. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Supraparamagnetic, conductive, and processable multifunctional graphene nanosheets coated with high-density Fe3O4 nanoparticles.

    Science.gov (United States)

    He, Hongkun; Gao, Chao

    2010-11-01

    The amazing properties of graphene are triggering extensive interests of both scientists and engineers, whereas how to fully utilize the unique attributes of graphene to construct novel graphene-based composites with tailor-made, integrated functions remains to be a challenge. Here, we report a facile approach to multifunctional iron oxide nanoparticle-attached graphene nanosheets (graphene@Fe(3)O(4)) which show the integrated properties of strong supraparamagnetism, electrical conductivity, highly chemical reactivity, good solubility, and excellent processability. The synthesis method is efficient, scalable, green, and controllable and has the feature of reduction of graphene oxide and formation of Fe(3)O(4) nanoparticles in one step. When the feed ratios are adjusted, the average diameter of Fe(3)O(4) nanoparticles (1.2-6.3 nm), the coverage density of Fe(3)O(4) nanoparticles on graphene nanosheets (5.3-57.9%), and the saturated magnetization of graphene@Fe(3)O(4) (0.5-44.1 emu/g) can be controlled readily. Because of the good solubility of the as-prepared graphene@Fe(3)O(4), highly flexible and multifunctional films composed of polyurethane and a high content of graphene@Fe(3)O(4) (up to 60 wt %) were fabricated by the solution-processing technique. The graphene@Fe(3)O(4) hybrid sheets showed electrical conductivity of 0.7 S/m and can be aligned into a layered-stacking pattern in an external magnetic field. The versatile graphene@Fe(3)O(4) nanosheets hold great promise in a wide range of fields, including magnetic resonance imaging, electromagnetic interference shielding, microwave absorbing, and so forth.

  14. Heat conduction

    International Nuclear Information System (INIS)

    Grigull, U.; Sandner, H.

    1984-01-01

    Included are discussions of rates of heat transfer by conduction, the effects of varying and changing properties, thermal explosions, distributed heat sources, moving heat sources, and non-steady three-dimensional conduction processes. Throughout, the importance of thinking both numerically and symbolically is stressed, as this is essential to the development of the intuitive understanding of numerical values needed for successful designing. Extensive tables of thermophysical properties, including thermal conductivity and diffusivity, are presented. Also included are exact and approximate solutions to many of the problems that arise in practical situations

  15. Development of 2D and 3D structured textile batteries processing conductive material with Tailored Fiber Placement (TFP)

    Science.gov (United States)

    Normann, M.; Grethe, T.; Zöll, K.; Ehrmann, A.; Schwarz-Pfeiffer, A.

    2017-10-01

    In recent years smart textiles have gained a significant increase of attention. Electrotherapeutic socks, light emitting dresses or shirts with integrated sensors, having the ability to process data of vital parameters, are just a few examples and the full potential is not yet exhausted: Smart textiles are not only used for clothing purposes. Sensors for the care of the elderly, light applications for home textiles and monitoring systems in the automotive section are promising fields for the future. For all these electrical and electronic features, the supply of power is needed. The most common used power supplies, however, are not flexible, often not lightweight and therefore a huge problem for the integration into textile products. In recent projects, textile-based batteries are being developed. Metal-coated fabrics and yarns (e.g. silver, copper, nickel, zinc) as well as carbon based materials were used to create textile based energy sources. This article gives an overview of textile based electrochemical cells by combining different conductive yarns and a gel-electrolyte. The available materials will be processed by embroidering utilizing tailored fiber placement (TFP). The electrical characteristics of different embroidered patterns and material combinations are examined.

  16. Impaired neurocognitive functions affect social learning processes in oppositional defiant disorder and conduct disorder: implications for interventions.

    Science.gov (United States)

    Matthys, Walter; Vanderschuren, Louk J M J; Schutter, Dennis J L G; Lochman, John E

    2012-09-01

    In this review, a conceptualization of oppositional defiant (ODD) and conduct disorder (CD) is presented according to which social learning processes in these disorders are affected by neurocognitive dysfunctions. Neurobiological studies in ODD and CD suggest that the ability to make associations between behaviors and negative and positive consequences is compromised in children and adolescents with these disorders due to reduced sensitivity to punishment and to reward. As a result, both learning of appropriate behavior and learning to refrain from inappropriate behavior may be affected. Likewise, problem solving is impaired due to deficiencies in inhibition, attention, cognitive flexibility, and decision making. Consequently, children and adolescents with ODD and CD may have difficulty learning to optimize their behavior in changeable environments. This conceptualization of ODD and CD is relevant for the improvement of the effect of psychological treatments. Behavioral and cognitive-behavioral interventions that have been shown to be modestly effective in ODD and CD are based on social learning. Limited effectiveness of these interventions may be caused by difficulties in social learning in children and adolescents with ODD and CD. However, although these impairments have been observed at a group level, the deficits in reward processing, punishment processing, and cognitive control mentioned above may not be present to the same extent in each individual with ODD and CD. Therefore, the neurocognitive characteristics in children and adolescents with ODD and CD should be assessed individually. Thus, instead of delivering interventions in a standardized way, these programs may benefit from an individualized approach that depends on the weaknesses and strengths of the neurocognitive characteristics of the child and the adolescent.

  17. Effect of degree of order of silicon dioxide on localization processes of non-equilibrium charge carriers under the influence of gamma-radiation

    CERN Document Server

    Garibov, A A; Agaev, T N

    1999-01-01

    The effect of the degree of order of SiO sub 2 on the localization process of non-equilibrium charge carriers (NCC) when exposed to gamma-quanta at 77 K has been investigated. It has been found that with decreasing SiO sub 2 structure degree of order, a localization probability of NCC increases. A contribution of surface defect states in SiO sub 2 to localization, migration and recombination annihilation processes of NCC induced by ionizing radiation has been determined.

  18. Charged corpuscular beam detector

    Energy Technology Data Exchange (ETDEWEB)

    Hikawa, H; Nishikawa, Y

    1970-09-29

    The present invention relates to a charged particle beam detector which prevents transient phenomena disturbing the path and focusing of a charged particle beam travelling through a mounted axle. The present invention provides a charged particle beam detector capable of decreasing its reaction to the charge in energy of the charged particle beam even if the relative angle between the mounted axle and the scanner is unstable. The detector is characterized by mounting electrically conductive metal pieces of high melting point onto the face of a stepped, heat-resistant electric insulating material such that the pieces partially overlap each other and individually provide electric signals, whereby the detector is no longer affected by the beam. The thickness of the metal piece is selected so that an eddy current is not induced therein by an incident beam, thus the incident beam is not affected. The detector is capable of detecting a misaligned beam since the metal pieces partially overlap each other.

  19. The Organic Chemistry of Conducting Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Tolbert, Laren Malcolm [Georgia Inst. of Technology, Atlanta, GA (United States)

    2014-12-01

    For the last several years, we have examined the fundamental principles of conduction in one-dimensional systems, i.e., molecular “wires”. It is, of course, widely recognized that such systems, as components of electronically conductive materials, function in a two- and three-dimensional milieu. Thus interchain hopping and grain-boundary resistivity are limiting conductivity factors in highly conductive materials, and overall conductivity is a function of through-chain and boundary hopping. We have given considerable attention to the basic principles underlying charge transport (the “rules of the game”) in two-dimensional systems by using model systems which allow direct observation of such processes, including the examination of tunneling and hopping as components of charge transfer. In related work, we have spent considerable effort on the chemistry of conjugated heteropolymers, most especially polythiophens, with the aim of using these most efficient of readily available electroactive polymers in photovoltaic devices.

  20. Influence of expander components on the processes at the negative plates of lead-acid cells on high-rate partial-state-of-charge cycling. Part I: Effect of lignosulfonates and BaSO{sub 4} on the processes of charge and discharge of negative plates

    Energy Technology Data Exchange (ETDEWEB)

    Pavlov, D.; Nikolov, P.; Rogachev, T. [Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Street, bl. 10, Sofia 1113 (Bulgaria)

    2010-07-15

    This study investigates the influence of the organic expander component (Vanisperse A) and of BaSO{sub 4} on the performance of negative lead-acid battery plates on high-rate partial-state-of-charge (HRPSoC) cycling. Batteries operating in the HRPSoC mode should be classified as a separate type of lead-acid batteries. Hence, the additives to the negative plates should differ from the conventional expander composition. It has been established that lignosulfonates are adsorbed onto the lead surface and thus impede the charge processes, which results in impaired reversibility of the charge-discharge processes and hence shorter cycle life on HRPSoC operation, limited by sulfation of the negative plates. BaSO{sub 4} exerts the opposite effect: it improves the reversibility of the processes in the HRPSoC mode and hence prolongs the cycle life of the cells. The most pronounced effect of BaSO{sub 4} has been registered when it is added in concentration of 1.0 wt.% versus the leady oxide (LO) used for paste preparation. It has also been established that BaSO{sub 4} lowers the overpotential of PbSO{sub 4} nucleation. The results of the present investigation indicate that BaSO{sub 4} affects also the crystallization process of Pb during cell charging. Thus, BaSO{sub 4} eventually improves the performance characteristics of lead-acid cells on HRPSoC cycling. (author)

  1. Charge-trapping effect of doped fluorescent dye on the electroluminescent processes and its performance in polymer light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Ye Tengling; Chen Zhenyu; Chen Jiangshan [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China); Ma Dongge, E-mail: mdg1014@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China)

    2010-11-15

    We have measured the temperature dependence of the steady-state current-voltage (I-V) characteristics and the transient electroluminescent (EL) characteristics in 4-(dicyanomethylene)-2-t-propyl-6-(1,1,7, 7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped polyfluorene devices to study the charge-trapping effect of DCJTB fluorescent dye on luminescence processes and on device performance. Physical and chemical analyses prove that DCJTB molecules serve both as electron and hole traps, and the charge-trapping effect is more sensitive against the electrons than the holes at the low dopant concentration. This intrinsic characteristic causes the electron to be injected into the emitting layer first and then trapped in the bulk, producing a strong effect on device performance.

  2. Internal Charging

    Science.gov (United States)

    Minow, Joseph I.

    2014-01-01

    (1) High energy (>100keV) electrons penetrate spacecraft walls and accumulate in dielectrics or isolated conductors; (2) Threat environment is energetic electrons with sufficient flux to charge circuit boards, cable insulation, and ungrounded metal faster than charge can dissipate; (3) Accumulating charge density generates electric fields in excess of material breakdown strenght resulting in electrostatic discharge; and (4) System impact is material damage, discharge currents inside of spacecraft Faraday cage on or near critical circuitry, and RF noise.

  3. Influence of expander components on the processes at the negative plates of lead-acid cells on high-rate partial-state-of-charge cycling. Part II. Effect of carbon additives on the processes of charge and discharge of negative plates

    Energy Technology Data Exchange (ETDEWEB)

    Pavlov, D.; Nikolov, P.; Rogachev, T. [Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Street, bl. 10, Sofia 1113 (Bulgaria)

    2010-07-15

    Lead-acid batteries operated in the high-rate partial-state-of-charge (HRPSoC) duty rapidly lose capacity on cycling, because of sulfation of the negative plates. As the battery operates from a partially discharged state, the small PbSO{sub 4} crystals dissolve and precipitate onto the bigger crystals. The latter have low solubility and hence PbSO{sub 4} accumulates progressively in the negative plates causing capacity loss. In order to suppress this process, the rate of the charge process should be increased. In a previous publication of ours we have established that reduction of Pb{sup 2+} ions to Pb may proceed on the surface of both Pb and carbon black particles. Hence, the reversibility of the charge-discharge processes improves, which leads to improved cycle life performance of the batteries in the HRPSoC mode. However, not all carbon forms accelerate the charge processes. The present paper discusses the electrochemical properties of two groups of carbon blacks: Printex and active carbons. The influence of Vaniseprse A and BaSO{sub 4} (the other two components of the expander added to the negative plates) on the reversibility of the charge-discharge processes on the negative plates is also considered. It has been established that lignosulfonates are adsorbed onto the lead surface and retard charging of the battery. BaSO{sub 4} has the opposite effect, which improves the reversibility of the processes on cycling and hence prolongs battery life in the HRPSoC duty. It has been established that the cycle life of lead-acid cells depends on the type of carbon black or active carbon added to the negative plates. When the carbon particles are of nano-sizes (<180 nm), the HRPSoC cycle life is between 10,000 and 20,000 cycles. Lignosulfonates suppress this beneficial effect of carbon black and activated carbon additives to about 10,000 cycles. Cells with active carbons have the longest cycle life when they contain also BaSO{sub 4} but no lignosulfonate. A summary of

  4. Dosimeter charging apparatus

    International Nuclear Information System (INIS)

    Reuter, F.A.; Moorman, Ch.J.

    1985-01-01

    An apparatus for charging a dosimeter which has a capacitor connected between first and second electrodes and a movable electrode in a chamber electrically connected to the first electrode. The movable electrode deflects varying amounts depending upon the charge present on said capacitor. The charger apparatus includes first and second charger electrodes couplable to the first and second dosimeter electrodes. To charge the dosimeter, it is urged downwardly into a charging socket on the charger apparatus. The second dosimeter electrode, which is the dosimeter housing, is electrically coupled to the second charger electrode through a conductive ring which is urged upwardly by a spring. As the dosimeter is urged into the socket, the ring moves downwardly, in contact with the second charger electrode. As the dosimeter is further urged downwardly, the first dosimeter electrode and first charger electrode contact one another, and an insulator post carrying the first and second charger electrodes is urged downwardly. Downward movement of the post effects the application of a charging potential between the first and second charger electrodes. After the charging potential has been applied, the dosimeter is moved further into the charging socket against the force of a relatively heavy biasing spring until the dosimeter reaches a mechanical stop in the charging socket

  5. A Markov chain approach to modelling charge exchange processes of an ion beam in monotonically increasing or decreasing potentials

    International Nuclear Information System (INIS)

    Shrier, O; Khachan, J; Bosi, S

    2006-01-01

    A Markov chain method is presented as an alternative approach to Monte Carlo simulations of charge exchange collisions by an energetic hydrogen ion beam with a cold background hydrogen gas. This method was used to determine the average energy of the resulting energetic neutrals along the path of the beam. A comparison with Monte Carlo modelling showed a good agreement but with the advantage that it required much less computing time and produced no numerical noise. In particular, the Markov chain method works well for monotonically increasing or decreasing electrostatic potentials. Finally, a good agreement is obtained with experimental results from Doppler shift spectroscopy on energetic beams from a hollow cathode discharge. In particular, the average energy of ions that undergo charge exchange reaches a plateau that can be well below the full energy that might be expected from the applied voltage bias, depending on the background gas pressure. For example, pressures of ∼20 mTorr limit the ion energy to ∼20% of the applied voltage

  6. Study of charge transfer processes in porphyrins- and phthalocyanins-based materials: from the liquid phase to the solid state

    International Nuclear Information System (INIS)

    Fournier, Thierry

    1994-01-01

    In order to efficiently conceive and build supramolecular materials for molecular electronics and optoelectronics, one need to have access to a large data base on the interactions between the elementary pieces of the material. Such a data base can be established only through the study of model Systems and model media. Oligomers of porphyrins and phthalocyanines constitute models of choice: due to the chemical versatility of the compounds, their physical and photophysical properties can be adjusted to produce a targeted function. The first part of this thesis is concerned with double- and triple-Decker mixed porphyrin and Phthalocyanines sandwich compounds of cerium. Then we study the photophysical properties of complexes formed by pairing in solution porphyrins and phthalocyanines bearing oppositely charged substituents. The charge transfer reactions and geminated recombinations are investigated by time-resolved absorption spectroscopy (from the femto- to millisecond time scales) for excited complexes either in solution, or confined in sol-gel matrices or in Langmuir-Blodgett films. The results obtained in the various media are compared and analysed by the Marcus theory. They allow to show that, for strongly coupled complexes, the solvent does not play any key role in the forward and backward electron transfer. We conclude this work by introducing a few targeted projects based on of the photophysical properties of these complexes, namely photodynamic therapy of cancers, nonlinear optics and the generation of photovoltage. (author) [fr

  7. Aggression in Children with Conduct Problems and Callous-Unemotional Traits: Social Information Processing and Response to Peer Provocation.

    Science.gov (United States)

    Helseth, Sarah A; Waschbusch, Daniel A; King, Sara; Willoughby, Michael T

    2015-11-01

    Callous/unemotional traits (CU) moderate children's conduct problems (CP) in numerous domains, including social functioning. The present study examined whether CU traits also moderate the aggressiveness of children's social information processing (SIP) and responses to varying intensities of peer provocation. Sixty elementary school-age children (46 males) were grouped into those without CP or CU (controls, n = 32), those with CP but not CU (CP-only; n = 14), and those with both CP and CU (CPCU, n = 14). Participants completed a task that measured two aspects of SIP (response generation and hostile attribution bias) and a computerized reaction time task (CRTT) that measured behavior, affect, and communication before and after provocation under instrumental and hostile aggressive conditions. Children with CPCU generated more aggressive responses than controls on measures of SIP. On the CRTT, all children exhibited reactive aggression following high provocation, but only children with CPCU exhibited proactive aggression, and reactive aggression following low provocation; no differences in affect were found. In a series of exploratory analyses, CPCU children communicated antisocially, while CP-only communicated prosocially. Finally, children with CPCU did not seem to hold a grudge following the final instance of provocation, instead gradually returning to baseline like their non-CU peers. These distinct social cognitive and behavioral profiles hint at different etiologies of CP and CPCU, underscoring the variability of aggression in these populations.

  8. Charge preamplifier

    International Nuclear Information System (INIS)

    Chaminade, R.; Passerieux, J.P.

    1961-01-01

    We describe a charge preamplifier having the following properties: - large open loop gain giving both stable gain and large input charge transfer; - stable input grid current with aging and without any adjustment; - fairly fast rise; - nearly optimum noise performance; - industrial material. (authors)

  9. Charge Meter

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 4. Charge Meter: Easy Way to Measure Charge and Capacitance: Some Interesting Electrostatic Experiments. M K Raghavendra V Venkataraman. Classroom Volume 19 Issue 4 April 2014 pp 376-390 ...

  10. Optimization of charge transfer and transport processes at the CdSe quantum dots/TiO2 nanorod interface by TiO2 interlayer passivation

    International Nuclear Information System (INIS)

    Jaramillo-Quintero, O A; Rincon, M E; Triana, M A

    2017-01-01

    Surface trap states hinder charge transfer and transport properties in TiO 2 nanorods (NRs), limiting its application on optoelectronic devices. Here, we study the interfacial processes between rutile TiO 2 NR and CdSe quantum dots (QDs) using TiO 2 interlayer passivation treatments. Anatase or rutile TiO 2 thin layers were deposited on an NR surface by two wet-chemical deposition treatments. Reduced interfacial charge recombination between NRs and CdSe QDs was observed by electrochemical impedance spectroscopy with the introduction of TiO 2 thin film interlayers compared to bare TiO 2 NRs. These results can be ascribed to in-gap trap state passivation of the TiO 2 NR surface, which led to an increase in open circuit voltage. Moreover, the rutile thin layer was more efficient than anatase to promote a higher photo-excited electron transfer from CdSe QDs to TiO 2 NRs due to a large driving force for charge injection, as confirmed by surface photovoltage spectroscopy. (paper)

  11. Influence of Fe{sub 3}O{sub 4} nanoparticles on pseudocapacitive behavior of the charge storage process

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chien-Chon [Department of Energy Engineering, National United University, Miaoli 36003, Taiwan (China); Research Center for Biomedical Devices and Prototyping Production, Taipei Medical University, Taipei 11031, Taiwan (China); Chen, Chin-Yi; Tsay, Chien-Yie; Wang, Sih-Ying [Department of Materials Science and Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Lin, Chung-Kwei, E-mail: chungkwei@tmu.edu.tw [Research Center for Biomedical Devices and Prototyping Production, Taipei Medical University, Taipei 11031, Taiwan (China); School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei 11031, Taiwan (China)

    2015-10-05

    Highlights: • A simple and inexpensive process formed pseudocapacitive manganese oxide electrode. • Mn(OH){sub x} decomposed into Mn{sub 3}O{sub 4} and Mn{sub 2}O{sub 3} phases and formed many small pores on the film. • The composite film with Fe{sub 3}O{sub 4} added presents small holes and large active surface. • The specific capacitance value can be enhanced by adding iron oxide. • The manganese oxide film has a specific capacitance of 209.9 F/g at 300 °C annealing. - Abstract: Nano-crystalline Fe{sub 3}O{sub 4} powders were added to form manganese oxide/iron oxide composite film electrode in order to combine the excellent capacitance characteristics of manganese oxide and iron oxide. Due to the addition of Fe{sub 3}O{sub 4}, the crack film formation increases the contact area of electrolyte and electrode and the surface and electronic conductivity of pseudo-capacitors increased. The specific capacitance value can be enhanced by adding iron oxide. The surface of the composite film with Fe{sub 3}O{sub 4} added had small holes due to the burnout of organics, and the network of nano-powders formed uniform and fine pores at 300 °C annealing. The EXAFS results to the XRD results, the peaks shift due to the formation of Mn{sub 3}O{sub 4} and Mn{sub 2}O{sub 3} between 250 and 350 °C. The best results in this study were 316.1 F/g obtained at 1 at.% of manganese oxide/iron oxide composite film electrode after 300 °C annealing. The 1 at.% manganese oxide/iron oxide composite film electrode after 1000 cycles, the highest specific capacitance value was 85.8%. The results showed that manganese oxide/iron oxide composite film electrode have good cycle stability of capacitance.

  12. Macrocluster desorption effect caused by single MCI: charges of gold clusters (2-20 nm) desorbed due to electronic processes induced by fission fragment bombardment in nanodispersed gold targets

    International Nuclear Information System (INIS)

    Baranov, I.; Jarmiychuk, S.; Kirillov, S.; Novikov, A.; Obnorskii, V.; Pchelintsev, A.; Wien, K.; Reimann, C.

    1999-01-01

    In this work the charge state of the negatively charged gold nanocluster ions (2-20 nm) that were desorbed from nanodispersed gold islet targets by 252 Cf fission fragments via electronic processes is studied. Mean cluster charge was calculated as a ratio of mean cluster mass to mean mass-to-charge ratio . Cluster masses were measured by means of a collector technique employing transmission electron microscopy and scanning force microscopy, while m/q was measured by means of a tandem TOF-spectrometer. It is shown that the nanocluster ions are mostly multiply charged (2-16e) and the charge increases non-linearly with the cluster size. The results are discussed

  13. Charge-transfer state excitation as the main mechanism of the photodarkening process in ytterbium-doped aluminosilicate fibres

    Energy Technology Data Exchange (ETDEWEB)

    Bobkov, K K; Rybaltovsky, A A; Vel' miskin, V V; Likhachev, M E; Bubnov, M M; Dianov, E M [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation); Umnikov, A A; Gur' yanov, A N; Vechkanov, N N [G.G.Devyatykh Institute of Chemistry of High-Purity Substances, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation); Shestakova, I A [Open Joint-Stock Company M.F. Stel' makh Polyus Research Institute, Moscow (Russian Federation)

    2014-12-31

    We have studied photodarkening in ytterbium-doped fibre preforms with an aluminosilicate glass core. Analysis of their absorption and luminescence spectra indicates the formation of stable Yb{sup 2+} ions in the glass network under IR laser pumping at a wavelength λ = 915 nm and under UV irradiation with an excimer laser (λ = 193 nm). We have performed comparative studies of the luminescence spectra of the preforms and crystals under excitation at a wavelength of 193 nm. The mechanism behind the formation of Yb{sup 2+} ions and aluminium – oxygen hole centres (Al-OHCs), common to ytterbium-doped YAG crystals and aluminosilicate glass, has been identified: photoinduced Yb{sup 3+} charge-transfer state excitation. (optical fibres)

  14. Big-bang nucleosynthesis with a long-lived charged massive particle including He4 spallation processes

    Science.gov (United States)

    Jittoh, Toshifumi; Kohri, Kazunori; Koike, Masafumi; Sato, Joe; Sugai, Kenichi; Yamanaka, Masato; Yazaki, Koichi

    2011-08-01

    We propose helium-4 spallation processes induced by long-lived stau in supersymmetric standard models, and investigate an impact of the processes on light elements abundances. We show that, as long as the phase space of helium-4 spallation processes is open, they are more important than stau-catalyzed fusion and hence constrain the stau property.

  15. The Impact of the discreteness of low-fluence ion beam processing on the spatial architecture of GaN nanostructures fabricated by surface charge lithography

    International Nuclear Information System (INIS)

    Tiginyanu, I.M.; Volciuc, O.; Gutowski, J.; Stevens-Kalceff, M.A.; Popa, V.; Wille, S.; Adelung, R.; Foell, H.

    2013-01-01

    We show that the discrete nature of ion beam processing used as a component in the approach of surface charge lithography leads to spatial modulation of the edges of the GaN nanostructures such as nanobelts and nanoperforated membranes. According to the performed Monte Carlo simulations, the modulation of the nanostructure edges is caused by the stochastic spatial distribution of the radiation defects generated by the impacting ions and related recoils. The obtained results pave the way for direct visualization of the networks of radiation defects induced by individual ions impacting a solid-state material. (authors)

  16. Mixtures of Charged Bosons Confined in Harmonic Traps and Bose-Einstein Condensation Mechanism for Low-Energy Nuclear Reactions and Transmutation Processes in Condensed Matters

    Science.gov (United States)

    Kim, Yeong E.; Zubarev, Alexander L.

    2006-02-01

    A mixture of two different species of positively charged bosons in harmonic traps is considered in the mean-field approximation. It is shown that depending on the ratio of parameters, the two components may coexist in same regions of space, in spite of the Coulomb repulsion between the two species. Application of this result is discussed for the generalization of the Bose-Einstein condensation mechanism for low-energy nuclear reaction (LENR) and transmutation processes in condensed matters. For the case of deutron-lithium (d + Li) LENR, the result indicates that (d + 6Li) reactions may dominate over (d + d) reactions in LENR experiments.

  17. Mixtures of charged bosons confined in harmonic traps and Bose-Einstein condensation mechanism for low-energy nuclear reactions and transmutation processes in condensed matters

    Energy Technology Data Exchange (ETDEWEB)

    Yeong, E. Kim; Zubarev, Alexander L. [Purdue Nuclear and Many-Body Theory Group (PNMBTG) Department of Physics, Purdue University, West Lafayette, IN 47907 (United States)

    2006-07-01

    A mixture of two different species of positively charged bosons in harmonic traps is considered in the mean-field approximation. It is shown that depending on the ratio of parameters, the two components may coexist in some regions of space, in spite of the Coulomb repulsion between the two species. Application of this result is discussed for the generalization of the Bose-Einstein condensation mechanism for low-energy nuclear reaction (LENR) and transmutation processes in condensed matters. For the case of deuteron-lithium (d + Li) LENR, the result indicates that (d + {sup 6}Li) reactions may dominate over (d + d) reactions in LENR experiments. (authors)

  18. Mixtures of charged bosons confined in harmonic traps and Bose-Einstein condensation mechanism for low-energy nuclear reactions and transmutation processes in condensed matters

    International Nuclear Information System (INIS)

    Yeong, E. Kim; Zubarev, Alexander L.

    2006-01-01

    A mixture of two different species of positively charged bosons in harmonic traps is considered in the mean-field approximation. It is shown that depending on the ratio of parameters, the two components may coexist in some regions of space, in spite of the Coulomb repulsion between the two species. Application of this result is discussed for the generalization of the Bose-Einstein condensation mechanism for low-energy nuclear reaction (LENR) and transmutation processes in condensed matters. For the case of deuteron-lithium (d + Li) LENR, the result indicates that (d + 6 Li) reactions may dominate over (d + d) reactions in LENR experiments. (authors)

  19. Organic conductive films for semiconductor electrodes

    Science.gov (United States)

    Frank, Arthur J.

    1984-01-01

    According to the present invention, improved electrodes overcoated with conductive polymer films and preselected catalysts are provided. The electrodes typically comprise an inorganic semiconductor overcoated with a charge conductive polymer film comprising a charge conductive polymer in or on which is a catalyst or charge-relaying agent.

  20. Charge independence and charge symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Miller, G A [Washington Univ., Seattle, WA (United States). Dept. of Physics; van Oers, W T.H. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Physics; [TRIUMF, Vancouver, BC (Canada)

    1994-09-01

    Charge independence and charge symmetry are approximate symmetries of nature, violated by the perturbing effects of the mass difference between up and down quarks and by electromagnetic interactions. The observations of the symmetry breaking effects in nuclear and particle physics and the implications of those effects are reviewed. (author). 145 refs., 3 tabs., 11 figs.

  1. Charge independence and charge symmetry

    International Nuclear Information System (INIS)

    Miller, G.A.

    1994-09-01

    Charge independence and charge symmetry are approximate symmetries of nature, violated by the perturbing effects of the mass difference between up and down quarks and by electromagnetic interactions. The observations of the symmetry breaking effects in nuclear and particle physics and the implications of those effects are reviewed. (author). 145 refs., 3 tabs., 11 figs

  2. Process evaluation of two environmental nutrition programmes and an educational nutrition programme conducted at supermarkets and worksite cafeterias in the Netherlands

    NARCIS (Netherlands)

    I.H.M. Steenhuis; P. van Assema (Patricia); A. Reubsaet; G.J. Kok (Gerjo)

    2004-01-01

    textabstractThis article describes the process evaluation of two environmental programs and a educational nutrition program, implemented at supermarkets and worksite cafeterias. Studies conducted earlier, indicated that the programs had no effect on consumers’ eating behavior. Consequently, the more

  3. Correlating shaped charge performance with processing conditions and microstructure of an aluminum alloy 1100 liner enabled by a new method to arrest nascent jet formation

    Science.gov (United States)

    Scheid, James Eric

    Aluminum-lined shaped charges are used in special applications where jet and / or slug residue in the target is undesired. The three different microstructures of the aluminum liners studied herein resulted from three different manufacturing interpretations of the same design. One interpretation was completely machining the liners from best available annealed round stock. The second was to cold-forge the liners from annealed round-stock in an open-die forge to near-final dimensions, and then machine the liners to the final dimensions. The third variant in this study was to use the above forged liner, but with annealing after the machining. These three manufacturing choices resulted in significant variations in shaped charge performance. The goal of this research was to clarify the relationships between the liner metal microstructure and properties, and the corresponding shaped charge dynamic flow behavior. What began as an investigation into user-reported performance problems associated inherently with liner manufacturing processes and resultant microstructure, resolved into new understandings of the relationships between aluminum liner microstructure and shaped charge collapse kinetics. This understanding was achieved through an extensive literature review and the comprehensive characterization of the material properties of three variants of an 1100 aluminum shaped charge liner with a focus on collapse and nascent jet formation. The machined liner had a microstructure with large millimeter-sized grains and fine particles aligned in bands parallel to the charge axis. The forged liner microstructure consisted of very small one micrometer-sized (1 mum) subgrains and fine particles aligned largely in bands elongated parallel to the liner contour. The annealed liner was characterized by ten micrometer (10 mum) sized equiaxed grains with residual fine particles in the forged alignment. This characterization was enabled by the development, execution and validation of a

  4. A study of the oriented composites with the conductive segregated structure obtained via solid-phase processing of the UHMWPE reactor powder mixed with the carbon nanofillers

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, Oleg V. [Moscow Institute of Physics and Technology (State University,) Institutskiy per., Dolgoprudny, Moscow Region, 141700 (Russian Federation); N.S. Enikolopov Institute of Synthetic Polymer Materials of RAS, Profsoyuznaya st., Moscow, 117393 (Russian Federation); Kechek’yan, Alexander S.; Shevchenko, Vitaly G.; Kurkin, Tikhon S.; Golubev, Evgeny K.; Ozerin, Alexander N. [N.S. Enikolopov Institute of Synthetic Polymer Materials of RAS, Profsoyuznaya st., Moscow, 117393 (Russian Federation); Karpushkin, Evgeny A.; Sergeev, Vladimir G. [Moscow State University, Chemical Department, Leninskie Gori, Moscow, 119234 (Russian Federation)

    2016-05-18

    Electrically conductive oriented polymer nano-composites of different compositions, based on the reactor powder of ultra-high-molecular-weight polyethylene (UHMWPE) with a special morphology, filled with particles of nanostructured graphite (NG), multi-walled carbon nanotubes (MWCNTs), and electrically conductive carbon black (CB), were investigated. Polymer composites were obtained via compaction of the mechanical mixture of the polymer and filler powder, followed by uniaxial deformation of the material under homogeneous shear (HS) conditions (all of the processing stages were conducted at room temperature). Resulted composites possess a high tensile strength, high level of the electrical conductivity and low percolation threshold, owing it to the formation of the segregated conductive structure, The influence of the type of nanosized carbon filler, degree of the deformation under HS condition, temperature and etc. on the electrical conductivity and mechanical properties of strengthened conductive composites oriented under homogeneous shear conditions was investigated. Changes in the electrical conductivity of oriented composite materials during reversible “tension–shrinkage” cycles along the orientation axis direction were studied. A theoretical approach, describing the process of transformation of the conductive system as a response on polymer phase deformation and volume change, was proposed, based on the data received from the analysis of the conductivity behavior during the uniaxial deformation and thermal treatment of composites.

  5. Charge recombination processes in minerals studied using optically stimulated luminescence and time-resolved exo-electrons

    International Nuclear Information System (INIS)

    Tsukamoto, Sumiko; Murray, Andrew; Ankjaergaard, Christina; Jain, Mayank; Lapp, Torben

    2010-01-01

    A time-resolved optically stimulated exo-electron (TR-OSE) measurement system has been developed using a Photon Timer attached to a gas-flow semi-proportional pancake electron detector within a Risoe TL/OSL reader. The decay rate of the exo-electron emission after the stimulation pulse depends on the probability of (1) escape of electrons into the detector gas from the conduction band by overcoming the work function of the material and (2) thermalization of electrons in the conduction band, and subsequent re-trapping/recombination. Thus, we expect the exo-electron signal to reflect the instantaneous electron concentration in the conduction band. In this study, TR-OSE and time-resolved optically stimulated luminescence (TR-OSL) were measured for the first time using quartz, K-feldspar and NaCl by stimulating the samples using pulsed blue LEDs at different temperatures between 50 and 250 0 C after beta irradiation and preheating to 280 0 C. The majority of TR-OSE signals from all the samples decayed much faster than TR-OSL signals irrespective of the stimulation temperatures. This suggests that the lifetime of OSL in these dosimeters arises mainly from the relaxation of an excited state of the recombination centre, rather than from residence time of an electron in the conduction band.

  6. Ion-atom collisions with laser-prepared target: High resolution study of single charge exchange process

    International Nuclear Information System (INIS)

    Leredde, Arnaud

    2012-01-01

    Single charge transfer in low-energy Na"++"8"7Rb(5s,5p) collisions is investigated using magneto-optically trapped Rb atoms and high-resolution recoil-ion momentum spectroscopy. The three-dimensional reconstruction of the recoil-ion momentum provides accurate relative cross-sections for the active channels and the projectile scattering angle distributions. Thanks to the high experimental resolution, scattering structures such as diffraction-like oscillations in angular distributions are clearly observed. The measurements are compared with molecular close-coupling calculations and an excellent agreement is found. To go further in the test of the theory, the target is prepared in an oriented state. It is the first time that such collision experiments with oriented target is performed with such a high resolution. The right-left asymmetry expected for the scattering angle distribution is evidenced. The agreement between MOCC calculations and experiments is very good. Simple models developed for collisions with oriented target are also discussed. (author) [fr

  7. Evaluation of electrostatic charge effects on the data processing system and the orbiter communication and tracking receivers

    Science.gov (United States)

    Lawton, R. M.

    1975-01-01

    An analysis of radiated interference test results obtained from frictionally charged Orbiter TPS tile was presented. The tests included the measurement of noise pick-up by Orbiter S-band, L-band, C-band, and Ku-band antennas located beneath the tiles in a manner simulating their installation on Orbiter. In addition, the radiated field characteristics resulting from the static discharge was determined. The results are analyzed as to their effect on data bus equipment and on Orbiter Communications and Tracking (C&T) receivers. It was concluded that the radiated interference should have no effect on MDM's. However the CPU, IOP and PMU enclosures require some minor modification to assure immunity from P-static interference. Orbiter antenna tests indicate that the S-band receiver should not be affected by P-static noise. The TACAN and Radar Altimeter performance appears to be adequate but with a small margin. MSBLS performance is uncertain because laboratory instrumentation cannot approach the MSBLS sensitivity.

  8. Process for start-up and slack period operation of fully charged boilers, e. g. of coal pressure gasification plants, and boiler system to carry out the process

    Energy Technology Data Exchange (ETDEWEB)

    Meyer-Kahrweg, H

    1978-10-19

    For the start-up and slack period of fully charged boilers hot water of e.g. 180/sup 0/C from a high pressure heater which is fed by a start-up boiler is used. In the first instance the boiler, its preheater and the vaporizer are filled with hot water from the start-up boiler until a medium water level is obtained. Subsequently water from the water separator is recycled through the preheater and the boiler by forced circulation and it is heated up to the hot water temperature by the start-up boiler. After the desired temperature has been reached the pressure combustion is ignited and the circulation through the preheater is interrupted by reversing to direct feed back. A considerable shortening of the start-up time is achieved because no heat is released to the condensation water in the boiler system as is done usually.

  9. Out-of-equilibrium processes in suspensions of oppositely charged colloids: liquid-to-crystal nucleation and gel formation

    Science.gov (United States)

    Sanz, Eduardo

    2009-03-01

    We study the kinetics of the liquid-to-crystal transformation and of gel formation in colloidal suspensions of oppositely charged particles. We analyse, by means of both computer simulations and experiments, the evolution of a fluid quenched to a state point of the phase diagram where the most stable state is either a homogeneous crystalline solid or a solid phase in contact with a dilute gas. On the one hand, at high temperatures and high packing fractions, close to an ordered-solid/disordered-solid coexistence line, we find that the fluid-to-crystal pathway does not follow the minimum free energy route. On the other hand, a quench to a state point far from the ordered-crystal/disordered-crystal coexistence border is followed by a fluid-to-solid transition through the minimum free energy pathway. At low temperatures and packing fractions we observe that the system undergoes a gas-liquid spinodal decomposition that, at some point, arrests giving rise to a gel-like structure. Both our simulations and experiments suggest that increasing the interaction range favors crystallization over vitrification in gel-like structures. [4pt] In collaboration with Chantal Valeriani, Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands and SUPA, School of Physics, University of Edinburgh, JCMB King's Buildings, Mayfield Road, Edinburgh EH9 3JZ, UK; Teun Vissers, Andrea Fortini, Mirjam E. Leunissen, and Alfons van Blaaderen, Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University; Daan Frenke, FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands and Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, UK; and Marjolein Dijkstra, Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University.

  10. Extraction of sub-gap density of states via capacitance-voltage measurement for the erasing process in a TFT charge-trapping memory

    Science.gov (United States)

    Chiang, Yen-Chang; Hsiao, Yang-Hsuan; Li, Jeng-Ting; Chen, Jen-Sue

    2018-02-01

    Charge-trapping memories (CTMs) based on zinc tin oxide (ZTO) semiconductor thin-film transistors (TFTs) can be programmed by a positive gate voltage and erased by a negative gate voltage in conjunction with light illumination. To understand the mechanism involved, the sub-gap density of states associated with ionized oxygen vacancies in the ZTO active layer is extracted from optical response capacitance-voltage (C-V) measurements. The corresponding energy states of ionized oxygen vacancies are observed below the conduction band minimum at approximately 0.5-1.0 eV. From a comparison of the fitted oxygen vacancy concentration in the CTM-TFT after the light-bias erasing operation, it is found that the pristine-erased device contains more oxygen vacancies than the program-erased device because the trapped electrons in the programmed device are pulled into the active layer and neutralized by the oxygen vacancies that are present there.

  11. Precision measurement of the cross section of charged-current and neutral current processes at large Q2 at HERA with the polarized-electron beam

    International Nuclear Information System (INIS)

    Tran, Trong Hieu

    2010-03-01

    The inclusive cross sections for both charged and neutral current processes have been measured in interactions of longitudinally polarized electrons (positrons) with unpolarized protons using the full data samples collected by H1 at HERA-II. The data taken at a center-of-mass energy of 319 GeV correspond to an integrated luminosity of 149.1 pb -1 and 180.0 pb -1 for e - p and e + p collisions, representing an increase in statistics of a factor of 10 and 2, respectively, over the data from HERA-I. The measured double differential cross sections d 2 σ/dxdQ 2 cover more than two orders of magnitude in both Q 2 , the negative four-momentum transfer squared, up to 30000 GeV 2 , and Bjorken x, down to 0.003. The cross section data are compared to predictions of the Standard Model which is able to provide a good description of the data. The polarization asymmetry as a function of Q 2 is measured with improved precision, confirming the previous observation of P violation effect in neutral current ep scattering at distances down to 10 -18 m. The total cross sections of the charged current process, for Q 2 > 400 GeV 2 and inelasticity y ± beams and different polarization values. Together with the corresponding cross section obtained from the previously published unpolarized data, the polarization dependence of the charged current cross section is measured and found to be in agreement with the Standard Model prediction with the absence of right-handed charged current. The cross sections are combined with previously published data from H1 to obtain the most precise unpolarized measurements. These are used to extract the structure function xF 3 γZ which is sensitive to the valence quark distributions down to low x values. The new cross sections have also been used in a combined electroweak and QCD fit to significantly improve the light quark couplings to the Z-boson than those obtained based on the HERA-I data alone. (orig.)

  12. The SCOAP3 initiative and the Open Access Article-Processing-Charge market: global partnership and competition improve value in the dissemination of science

    CERN Document Server

    Romeu, Clément; Kohls, Alexander; Mansuy, Anne; Mele, Salvatore; Vesper, Martin

    2014-01-01

    The SCOAP3 (Sponsoring Consortium for Open Access Publishing in Particle Physics) initiative is an international partnership to convert to Open Access the published literature in the field of High-Energy Physics (HEP). It has been in operation since January 2014, and covers more than 4’000 articles/year. Originally initiated by CERN, the European Organization for Nuclear Research, and now counting partners representing 41 countries and 3 intergovernmental organizations, SCOAP3 has successfully converted to Open Access all, or part of, 6 HEP journals previously restricted to subscribers. It is also supporting publication of articles in 4 existing Open Access journals. As a “Gold” Open Access initiative, SCOAP3 pays Article Processing Charges (APCs), as publishers’ source of revenue for the publication service. Differentiating itself from other Open Access initiatives, SCOAP3 set APCs through a tendering process, correlating quality and price, at consistent conditions across participating publishers. Th...

  13. Theoretical study on the cooperative exciton dissociation process based on dimensional and hot charge-transfer state effects in an organic photocell

    International Nuclear Information System (INIS)

    Shimazaki, Tomomi; Nakajima, Takahito

    2016-01-01

    This paper discusses the exciton dissociation process at the donor–acceptor interface in organic photocells. In our previous study, we introduced a local temperature to handle the hot charge-transfer (CT) state and calculated the exciton dissociation probability based on the 1D organic semiconductor model [T. Shimazaki and T. Nakajima, Phys. Chem. Chem. Phys. 17, 12538 (2015)]. Although the hot CT state plays an essential role in exciton dissociations, the probabilities calculated are not high enough to efficiently separate bound electron–hole pairs. This paper focuses on the dimensional (entropy) effect together with the hot CT state effect and shows that cooperative behavior between both effects can improve the exciton dissociation process. In addition, we discuss cooperative effects with site-disorders and external-electric-fields.

  14. Conduction mechanism and the dielectric relaxation process of a-Se75Te25-xGax (x=0, 5, 10 and 15 at wt%) chalcogenide glasses

    International Nuclear Information System (INIS)

    Yahia, I.S.; Hegab, N.A.; Shakra, A.M.; Al-Ribaty, A.M.

    2012-01-01

    Se 75 Te 25-x Ga x (x=0, 5, 10 and 15 at wt%) chalcogenide compositions were prepared by the well known melt quenching technique. Thin films with different thicknesses in the range (185-630 nm) of the obtained compositions were deposited by thermal evaporation technique. X-ray diffraction patterns indicate that the amorphous nature of the obtained films. The ac conductivity and the dielectric properties of the studied films have been investigated in the frequency range (10 2 -10 5 Hz) and in the temperature range (293-333 K). The ac conductivity was found to obey the power low ω s where s≤1 independent of film thickness. The temperature dependence of both ac conductivity and the exponent s can be well interpreted by the correlated barrier hopping (CBH) model. The experimental results of the dielectric constant ε 1 and dielectric loss ε 2 are frequency and temperature dependent. The maximum barrier height W m calculated from the results of the dielectric loss according to the Guintini equation, and agrees with that proposed by the theory of hopping of charge carriers over a potential barrier as suggested by Elliott for chalcogenide glasses. The density of localized state was estimated for the studied film compositions. The variation of the studied properties with Ga content was also investigated. The correlation between the ac conduction and the dielectric properties were verified.

  15. A Novel Methodology for Charging Station Deployment

    Science.gov (United States)

    Sun, Zhonghao; Zhao, Yunwei; He, Yueying; Li, Mingzhe

    2018-02-01

    Lack of charging stations has been a main obstacle to the promotion of electric vehicles. This paper studies deploying charging stations in traffic networks considering grid constraints to balance the charging demand and grid stability. First, we propose a statistical model for charging demand. Then we combine the charging demand model with power grid constraints and give the formulation of the charging station deployment problem. Finally, we propose a theoretical solution for the problem by transforming it to a Markov Decision Process.

  16. Controlling charge on levitating drops.

    Science.gov (United States)

    Hilger, Ryan T; Westphall, Michael S; Smith, Lloyd M

    2007-08-01

    Levitation technologies are used in containerless processing of materials, as microscale manipulators and reactors, and in the study of single drops and particles. Presented here is a method for controlling the amount and polarity of charge on a levitating drop. The method uses single-axis acoustic levitation to trap and levitate a single, initially neutral drop with a diameter between 400 microm and 2 mm. This drop is then charged in a controllable manner using discrete packets of charge in the form of charged drops produced by a piezoelectric drop-on-demand dispenser equipped with a charging electrode. The magnitude of the charge on the dispensed drops can be adjusted by varying the voltage applied to the charging electrode. The polarity of the charge on the added drops can be changed allowing removal of charge from the trapped drop (by neutralization) and polarity reversal. The maximum amount of added charge is limited by repulsion of like charges between the drops in the trap. This charging scheme can aid in micromanipulation and the study of charged drops and particles using levitation.

  17. Charge transport problem

    International Nuclear Information System (INIS)

    Lee, E.P.

    1977-01-01

    In a recent report (UCID 17346, ''Relativistic Particle Beam in a Semi-Infinite Axially Symmetric conducting channel extending from a perfectly conducting plane,'' Dec. 13, 1976) Cooper and Neil demonstrate that the net charge transported by a beam pulse injected into a channel of finite conductivity equals the charge of the beam itself. The channel is taken to be infinite in the positive z direction, has finite radius and is terminated by a conducting ground plane at z =0. This result is not an obvious one, and it is restricted in its applicability by the special model assumed for the channel. It is the purpose to explain the result of Cooper and Neil in more qualitative terms and to make similar calculations using several other channel models. It must be emphasized that these calculations are not concerned with the fate of the transported charge after the pulse has stopped, but rather with how much charge leaves the ground plane assuming the pulse does not stop

  18. Nanoscale current spreading analysis in solution-processed graphene oxide/silver nanowire transparent electrodes via conductive atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Joseph E.; Perumal, Ajay; Bradley, Donal D. C.; Stavrinou, Paul N.; Anthopoulos, Thomas D., E-mail: t.anthopoulos@ic.ac.uk [Department of Physics and Centre for Plastic Electronics, Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom)

    2016-05-21

    We use conductive atomic force microscopy (CAFM) to study the origin of long-range conductivity in model transparent conductive electrodes composed of networks of reduced graphene oxide (rGO{sub X}) and silver nanowires (AgNWs), with nanoscale spatial resolution. Pristine networks of rGO{sub X} (1–3 monolayers-thick) and AgNWs exhibit sheet resistances of ∼100–1000 kΩ/□ and 100–900 Ω/□, respectively. When the materials are deposited sequentially to form bilayer rGO{sub X}/AgNW electrodes and thermally annealed at 200 °C, the sheet resistance reduces by up to 36% as compared to pristine AgNW networks. CAFM was used to analyze the current spreading in both systems in order to identify the nanoscale phenomena responsible for this effect. For rGO{sub X} networks, the low intra-flake conductivity and the inter-flake contact resistance is found to dominate the macroscopic sheet resistance, while for AgNW networks the latter is determined by the density of the inter-AgNW junctions and their associated resistance. In the case of the bilayer rGO{sub X}/AgNWs' networks, rGO{sub X} flakes are found to form conductive “bridges” between AgNWs. We show that these additional nanoscopic electrical connections are responsible for the enhanced macroscopic conductivity of the bilayer rGO{sub X}/AgNW electrodes. Finally, the critical role of thermal annealing on the formation of these nanoscopic connections is discussed.

  19. Charge recombination processes in minerals studied using optically stimulated luminescence and time-resolved exo-electrons

    DEFF Research Database (Denmark)

    Tsukamoto, Sumiko; Murray, Andrew; Ankjærgaard, Christina

    2010-01-01

    electron concentration in the conduction band. In this study, TR-OSE and time-resolved optically stimulated luminescence (TR-OSL) were measured for the first time using quartz, K-feldspar and NaCl by stimulating the samples using pulsed blue LEDs at different temperatures between 50 and 250 °C after beta...... irradiation and preheating to 280 °C. The majority of TR-OSE signals from all the samples decayed much faster than TR-OSL signals irrespective of the stimulation temperatures. This suggests that the lifetime of OSL in these dosimeters arises mainly from the relaxation of an excited state of the recombination...

  20. Correlated charge changing ion-atom collisions

    International Nuclear Information System (INIS)

    Bernstein, E.M.; Tanis, J.A.

    1990-02-01

    This report summarizes the progress and accomplishments in accelerator atomic physics research supported by DOE grant FG02-87ER13778 from August 15, 1987 through February 15, 1990. The general scope of this work involves the experimental investigation of fundamental atomic interactions in collisions of highly charged projectiles with neutral targets, with a particular emphasis on two-electron interactions. Inner-shell processes involving excitation, ionization, and charge transfer are investigated using, for the most part, coincidence techniques in which projectile charge-changing events are associated with x-ray emission, target recoil ions, or electron emission. Measurements were conducted using accelerators at the Lawrence Berkeley Laboratory (LBL), Argonne National Laboratory (ANL), Hahn-Meitner-Institut, Berlin (HMI), and Western Michigan University (WMU). The research described here has resulted in 34 published papers, 14 invited presentations at national and international meetings, and 31 contributed presentations. Brief summaries of work completed and work in progress are discussed in this paper

  1. 10 CFR 708.22 - What process does the Office of Hearings and Appeals use to conduct an investigation of the...

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false What process does the Office of Hearings and Appeals use to conduct an investigation of the complaint? 708.22 Section 708.22 Energy DEPARTMENT OF ENERGY DOE CONTRACTOR EMPLOYEE PROTECTION PROGRAM Investigation, Hearing and Decision Process § 708.22 What process does the Office of Hearings and Appeals use t...

  2. An experimental study of charge exchange process in the energy range 1-30 keV during the passage of alkali metal ions and atoms through cesium and potassium vapour

    International Nuclear Information System (INIS)

    Wittchow, F.

    1979-01-01

    An experimental study is presented of the charge exchange processes in the energy range of about 1-30 keV during the passage of positive alkali ions and alkali atoms through potassium and cesium vapour. The experimental set-up designed for this experiment includes a thermionic source for positive alkali ions with an acceleration stage, a first charge exchange cell to produce fast alkali atoms, a second charge exchange cell with a surface ionisation detector to determine the alkali metal vapor target thickness and a detection system with electrostatic bending of the charged secondary species. The maximum negative ion yield has been determined for the collision systems Li + + K, Na + + K, K + + K, and Rb + + K, and for another eleven systems the charge transfer cross-sections have been measured too. (orig./GG) [de

  3. You focus on the forest when you’re in charge of the trees: Power priming and abstract information processing

    NARCIS (Netherlands)

    Smith, P.K.; Trope, Y.

    2006-01-01

    Elevated power increases the psychological distance one feels from others, and this distance, according to construal level theory, should lead to more abstract information processing. Thus, high power should be associated with more abstract thinking-focusing on primary aspects of stimuli and

  4. Modification of microstructure and electrical conductivity of plasma-sprayed YSZ deposit through post-densification process

    International Nuclear Information System (INIS)

    Ning Xianjin; Li Chengxin; Li Changjiu; Yang Guanjun

    2006-01-01

    4.5 mol% yttria-stabilized zirconia (YSZ) coating was deposited by atmospheric plasma spraying (APS) as an electrolyte for solid oxide fuel cells (SOFCs) applications. The post treatment was employed using zirconium and yttrium nitrate solution infiltration to densify the coating microstructure for improvement of gas permeability. The deposition of YSZ through nitrate in voids of the coating was examined. Microstructure of the as-sprayed and densified coatings was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of infiltrating treatment on coating microstructure and electrical conductivity was examined. The electrical conductivity of APS-sprayed YSZ coating at the direction perpendicular to coating surface was much lower than that of bulk materials. Post-densification treatment improved the electrical conductivity of YSZ coating by about 25% compared with as-sprayed coating. It was found that the deposition of YSZ resulting from decomposition of nitrate in the lamellar interface gaps was different from that in vertical cracks in lamella owing to the orthogonal feature of those two types of gaps. The nanopores were formed in the deposited YSZ in nonbonded interface gaps while large pores were residued in vertical cracks in splats. The microstructural examination suggests that nanopores in the deposited YSZ in nonbonded interfaces in the coating were isolated from each other, which led to the significant reduction of gas permeability after densification. Moreover, the nanocontacts between lamellae resulted in high contact resistance and limit improvement of electrical conductivity of the coating after densification

  5. A comparative study of different processing methods and microwave surface conductivity of 1-2-3 superconducting ceramics

    International Nuclear Information System (INIS)

    Sundar, H.G.K.; Wilson, C.; Horzog, D.

    1988-01-01

    Superconducting YBa/sub 2/Cu/sub 3/O/sub 6+x/ samples were made from powders prepared by different routes: solid state reaction, amorphous citrate and Pechini method. The powders produced by solid state reaction were milled to different degrees, calcined and sintered. Samples were also hot pressed at 875 C and subsequently annealed at different temperatures to regain the superconducting phase. In order to compare the amount of residual carbonate in the final materials prepared by solid state and liquid mix methods, XPS spectra were taken on as calcined powder and on material sintered at different temperatures. To our surprise, the amount of carbonate was quite small in both the methods, but this amount increased with sintering temperature. The microwave surface conductivity of 1-2-3 superconducting material was measured in a disk resonator configuration. At liquid nitrogen temperatures the microwave conductivity was comparable to that of gold and improved with decreasing temperature. At --10K the conductivity was two orders of magnitude greater than that of gold at the same temperature. The surface conductivity of samples obtained by Pechini method was much better than that obtained by solid state method

  6. Measuring the implementation of codes of conduct. An assessment method based on a process approach of the responsible organisation

    NARCIS (Netherlands)

    Nijhof, A.H.J.; Cludts, Stephan; Fisscher, O.A.M.; Laan, Albertus

    2003-01-01

    More and more organisations formulate a code of conduct in order to stimulate responsible behaviour among their members. Much time and energy is usually spent fixing the content of the code but many organisations get stuck in the challenge of implementing and maintaining the code. The code then

  7. Highly efficient ZnO/Au Schottky barrier dye-sensitized solar cells: Role of gold nanoparticles on the charge-transfer process

    Directory of Open Access Journals (Sweden)

    Tanujjal Bora

    2011-10-01

    Full Text Available Zinc oxide (ZnO nanorods decorated with gold (Au nanoparticles have been synthesized and used to fabricate dye-sensitized solar cells (DSSC. The picosecond-resolved, time-correlated single-photon-count (TCSPC spectroscopy technique was used to explore the charge-transfer mechanism in the ZnO/Au-nanocomposite DSSC. Due to the formation of the Schottky barrier at the ZnO/Au interface and the higher optical absorptions of the ZnO/Au photoelectrodes arising from the surface plasmon absorption of the Au nanoparticles, enhanced power-conversion efficiency (PCE of 6.49% for small-area (0.1 cm2 ZnO/Au-nanocomposite DSSC was achieved compared to the 5.34% efficiency of the bare ZnO nanorod DSSC. The TCSPC studies revealed similar dynamics for the charge transfer from dye molecules to ZnO both in the presence and absence of Au nanoparticles. A slower fluorescence decay associated with the electron recombination process, observed in the presence of Au nanoparticles, confirmed the blocking of the electron transfer from ZnO back to the dye or electrolyte by the Schottky barrier formed at the ZnO/Au interface. For large area DSSC (1 cm2, ~130% enhancement in PCE (from 0.50% to 1.16% was achieved after incorporation of the Au nanoparticles into the ZnO nanorods.

  8. Charge transport studies in donor-acceptor block copolymer PDPP-TNT and PC71BM based inverted organic photovoltaic devices processed in room conditions

    International Nuclear Information System (INIS)

    Srivastava, Shashi B.; Singh, Samarendra P.; Sonar, Prashant

    2015-01-01

    Diketopyrrolopyrole-naphthalene polymer (PDPP-TNT), a donor-acceptor co-polymer, has shown versatile behavior demonstrating high performances in organic field-effect transistors (OFETs) and organic photovoltaic (OPV) devices. In this paper we report investigation of charge carrier dynamics in PDPP-TNT, and [6,6]-phenyl C 71 butyric acid methyl ester (PC71BM) bulk-heterojunction based inverted OPV devices using current density-voltage (J-V) characteristics, space charge limited current (SCLC) measurements, capacitance-voltage (C-V) characteristics, and impedance spectroscopy (IS). OPV devices in inverted architecture, ITO/ZnO/PDPP-TNT:PC71BM/MoO 3 /Ag, are processed and characterized at room conditions. The power conversion efficiency (PCE) of these devices are measured ∼3.8%, with reasonably good fill-factor 54.6%. The analysis of impedance spectra exhibits electron’s mobility ∼2 × 10 −3 cm 2 V −1 s −1 , and lifetime in the range of 0.03-0.23 ms. SCLC measurements give hole mobility of 1.12 × 10 −5 cm 2 V −1 s −1 , and electron mobility of 8.7 × 10 −4 cm 2 V −1 s −1

  9. Effects of weakly coupled and dense quantum plasmas environments on charge exchange and ionization processes in Na+ + Rb(5s) atom collisions

    Science.gov (United States)

    Pandey, Mukesh Kumar; Lin, Yen-Chang; Ho, Yew Kam

    2017-02-01

    The effects of weakly coupled or classical and dense quantum plasmas environment on charge exchange and ionization processes in Na+ + Rb(5s) atom collision at keV energy range have been investigated using classical trajectory Monte Carlo (CTMC) method. The interaction of three charged particles are described by the Debye-Hückel screen potential for weakly coupled plasma, whereas exponential cosine-screened Coulomb potential have been used for dense quantum plasma environment and the effects of both conditions on the cross sections are compared. It is found that screening effects on cross sections in high Debye length condition is quite small in both plasma environments. However, enhanced screening effects on cross sections are observed in dense quantum plasmas for low Debye length condition, which becomes more effective while decreasing the Debye length. Also, we have found that our calculated results for plasma-free case are comparable with the available theoretical results. These results are analyzed in light of available theoretical data with the choice of model potentials.

  10. Radiative corrections to the charged pion-pair production process {pi}{sup -}{gamma} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup -} at low energies

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, N.; Petschauer, S. [Technische Universitaet Muenchen, Physik-Department T39, Garching (Germany)

    2013-12-15

    We calculate the one-photon loop radiative corrections to the charged pion-pair production process {pi}{sup -}{gamma} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup -}. In the low-energy region this reaction is governed by the chiral pion-pion interaction. The pertinent set of 42 irreducible photon-loop diagrams is calculated by using the package FeynCalc. Electromagnetic counterterms with two independent low-energy constants k{sub 1} and k{sub 2} are included in order to remove the ultraviolet divergences generated by the photon loops. Infrared finiteness of the virtual radiative corrections is achieved by including soft photon radiation below an energy cut-off {Lambda}. The purely electromagnetic interaction of the charged pions mediated by one-photon exchange is also taken into account. The radiative corrections to the total cross section (in the isospin limit) vary between +10% close to threshold and about -1% at a center-of-mass energy of 7m{sub {pi}}. The largest contribution comes from the simple one-photon exchange. Radiative corrections to the {pi}{sup +}{pi}{sup -} and {pi}{sup -}{pi}{sup -} mass spectra are studied as well. The Coulomb singularity of the final-state interaction produces a kink in the dipion mass spectra. The virtual radiative corrections to elastic {pi}{sup -}{pi}{sup -} scattering are derived additionally. (orig.)

  11. Determination of critical density of charge

    International Nuclear Information System (INIS)

    Vila, F.

    1992-11-01

    In this work is given a full theoretically treatment of the problem how to determine the critical density of charge on nonconductive rectangular charged surfaces placed near a small spherical conductive and earthed surface. (author). 11 refs, 2 figs

  12. The role of surface charge in the desolvation process of gelatin: implications in nanoparticle synthesis and modulation of drug release

    Directory of Open Access Journals (Sweden)

    Ahsan SM

    2017-01-01

    Full Text Available Saad M Ahsan, Chintalagiri Mohan Rao Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, Telangana, India Abstract: The process of moving hydrophobic amino acids into the core of a protein by desolvation is important in protein folding. However, a rapid and forced desolvation can lead to precipitation of proteins. Desolvation of proteins under controlled conditions generates nanoparticles – homogeneous aggregates with a narrow size distribution. The protein nanoparticles, under physiological conditions, undergo surface erosion due to the action of proteases, releasing the entrapped drug/gene. The packing density of protein nanoparticles significantly influences the release kinetics. We have investigated the desolvation process of gelatin, exploring the role of pH and desolvating agent in nanoparticle synthesis. Our results show that the desolvation process, initiated by the addition of acetone, follows distinct pathways for gelatin incubated at different pH values and results in the generation of nanoparticles with varying matrix densities. The nanoparticles synthesized with varying matrix densities show variations in drug loading and protease-dependent extra- and intracellular drug release. These results will be useful in fine-tuning the synthesis of nanoparticles with desirable drug release profiles. Keywords: protein desolvation, nanoparticle assembly, gelatin nanoparticle synthesis, protease susceptibility, intracellular drug release

  13. Molecular orbital (SCF-Xα-SW) theory of metal-metal charge transfer processes in minerals - II. Application to Fe2+ --> Ti4+ charge transfer transitions in oxides and silicates

    Science.gov (United States)

    Sherman, David M.

    1987-01-01

    A molecular orbital description, based on Xα-Scattered wave calculations on a (FeTiO10)14− cluster, is given for Fe2+ → Ti4+ charge transfer transitions in minerals. The calculated energy for the lowest Fe2+ → Ti4+ metal-metal charge transfer transition is 18040 cm−1 in reasonable agreement with energies observed in the optical spectra of Fe-Ti oxides and silicates. As in the case of Fe2+ → Fe3+ charge transfer in mixed-valence iron oxides and silicates, Fe2+ → Ti4+ charge transfer is associated with Fe-Ti bonding across shared polyhedral edges. Such bonding results from the overlap of the Fe(t 2g ) and Ti(t 2g ) 3d orbitals.

  14. Handbook for Conducting Standard CMMI Appraisal Method for Process Improvement (SCAMPI) B and C Appraisals, Version 1.1

    National Research Council Canada - National Science Library

    Hayes, Will; Miluk, Gene; Ming, Lisa; Glover, Margaret; Bisgrove, Jane; Cort, Corrine; Penn, Lynn; Jacobson, Nils; Beynon, Don; Allgood, Bruce

    2005-01-01

    The Standard CMMI Appraisal Method for Process Improvement (SCAMPI) provides a well-defined, publicly available set of methodologies for providing appraisals relative to Capability Maturity Model (trademark) Integration (CMMI) models...

  15. Next Generation Thermal Management Materials: Boron Arsenide for Isotropic Diamond Like Thermal Conductivity - Affordable BAs Processing Innovations, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this SBIR phase I proposal is to design, develop and carry out the materials and process engineering studies to demonstrate the feasibility of...

  16. Effect of wall thermal conductivity on the heat transfer process in annular turbulent gas flow for constant wall temperature

    International Nuclear Information System (INIS)

    Groshev, A.I.; Anisimov, V.V.; Kashcheev, V.M.; Khudasko, V.V.; Yur'ev, Yu.S.

    1987-01-01

    The effect of wall material on convective heat transfer of turbulent gas flow in an annular tube with account of longitudinal diffusion both in the wall and in the liquid is studied numerically. The conjugated problem is solved for P r =0.7 (Re=10 4 -10 6 ). Based on numerical calculations it is stated that thermal conductivity of the wall and gas essentially affects the degree of preliminary heating of liquid in the range of a non-heated section

  17. Al-doped ZnO/Ag grid hybrid transparent conductive electrodes fabricated using a low-temperature process

    Energy Technology Data Exchange (ETDEWEB)

    An, Ha-Rim; Oh, Sung-Tag [Department of Materials Science and Engineering, Seoul National University of Science and Technology, Seoul 139-743 (Korea, Republic of); Kim, Chang Yeoul [Future Convergence Ceramic Division, Korea Institute Ceramic Engineering and Technology (KICET), Seoul 233-5 (Korea, Republic of); Baek, Seong-Ho [Energy Research Division, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 711-873 (Korea, Republic of); Park, Il-Kyu, E-mail: ikpark@ynu.ac.kr [Department of Electronic Engineering, Yeungnam University, Gyeongbuk 712-749 (Korea, Republic of); Ahn, Hyo-Jin, E-mail: hjahn@seoultech.ac.kr [Department of Materials Science and Engineering, Seoul National University of Science and Technology, Seoul 139-743 (Korea, Republic of)

    2014-12-05

    Highlights: • Al-doped ZnO/Ag transparent conductive electrode is fabricated at low temperature. • Performance of the hybrid transparent conductive electrode affected by the structure. • The performance enhancement mechanism is suggested. - Abstract: Al-doped ZnO (AZO)/Ag grid hybrid transparent conductive electrode (TCE) structures were fabricated at a low temperature by using electrohydrodynamic jet printing for the Ag grids and atomic layer deposition for the AZO layers. The structural investigations showed that the AZO/Ag grid hybrid structures consisted of Ag grid lines formed by Ag particles and the AZO layer covering the inter-spacing between the Ag grid lines. The Ag particles comprising the Ag grid lines were also capped by thin AZO layers, and the coverage of the AZO layers was increased with increasing the thickness of the AZO layer. Using the optimum thickness of AZO layer of 70 nm, the hybrid TCE structure showed an electrical resistivity of 5.45 × 10{sup −5} Ω cm, an optical transmittance of 80.80%, and a figure of merit value of 1.41 × 10{sup −2} Ω{sup −1}. The performance enhancement was suggested based on the microstructural investigations on the AZO/Ag grid hybrid structures.

  18. The electrical conductivity of model melts based on LiCl-KCl, used for the processing of spent nuclear fuel

    International Nuclear Information System (INIS)

    Salyulev, Alexander; Potapov, Alexei; Khokhlov, Vladimir; Shishkin, Vladimir

    2017-01-01

    During pyrochemical reprocessing of spent nuclear fuel, complex melts based on LiCl-KCl eutectic are formed, but their properties are still not well studied. We measured the electrical conductivity of (LiCl-KCl) eut. − CeCl 3 , (LiCl-KCl) eut. − NdCl 3 and (LiCl-KCl) eut. − UCl 3 quasi-binary melts was up to 40 mol.% CeCl 3 , 40 mol.% NdCl 3 and 10.45 mol.% UCl 3 in a wide temperature span. In addition the electrical conductivity of several compositions, such as (LiCl-KCl) eut. − CeCl 3 + NdCl 3 and (LiCl-KCl) eut. − CeCl 3 + NdCl 3 + UCl 3 was measured. The measurements were carried out in quartz cells of the capillary type. When the total concentration of trivalent ions is less than 12 mol.%, we found that the conductivity of mixtures of arbitrary composition is almost a linear function of CeCl 3 , NdCl 3 , and UCl 3 the overall concentration.

  19. Constitutional Law--Procedural Due Process--Student Has Right to Have Attorney Present at University Disciplinary Hearing When Criminal Charges Are Pending.

    Science.gov (United States)

    Vessels, Rodney Jay

    1978-01-01

    In the case of Gabrilowitz v Newman the court used the due process balancing test to conclude that a student has a right to have counsel present at a university disciplinary hearing where the conduct in question is the object of a pending criminal proceeding. Available from J. Reuben Clark Law School, Brigham Young U., Provo, UT 84602. (MSE)

  20. Charge-Domain Signal Processing of Direct RF Sampling Mixer with Discrete-Time Filters in Bluetooth and GSM Receivers

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available RF circuits for multi-GHz frequencies have recently migrated to low-cost digital deep-submicron CMOS processes. Unfortunately, this process environment, which is optimized only for digital logic and SRAM memory, is extremely unfriendly for conventional analog and RF designs. We present fundamental techniques recently developed that transform the RF and analog circuit design complexity to digitally intensive domain for a wireless RF transceiver, so that it enjoys benefits of digital and switched-capacitor approaches. Direct RF sampling techniques allow great flexibility in reconfigurable radio design. Digital signal processing concepts are used to help relieve analog design complexity, allowing one to reduce cost and power consumption in a reconfigurable design environment. The ideas presented have been used in Texas Instruments to develop two generations of commercial digital RF processors: a single-chip Bluetooth radio and a single-chip GSM radio. We further present details of the RF receiver front end for a GSM radio realized in a 90-nm digital CMOS technology. The circuit consisting of low-noise amplifier, transconductance amplifier, and switching mixer offers 32.5 dB dynamic range with digitally configurable voltage gain of 40 dB down to 7.5 dB. A series of decimation and discrete-time filtering follows the mixer and performs a highly linear second-order lowpass filtering to reject close-in interferers. The front-end gains can be configured with an automatic gain control to select an optimal setting to form a trade-off between noise figure and linearity and to compensate the process and temperature variations. Even under the digital switching activity, noise figure at the 40 dB maximum gain is 1.8 dB and +50 dBm IIP2 at the 34 dB gain. The variation of the input matching versus multiple gains is less than 1 dB. The circuit in total occupies 3.1 mm 2 . The LNA, TA, and mixer consume less than 15.3 mA at a supply voltage of 1.4 V.

  1. Charge-Domain Signal Processing of Direct RF Sampling Mixer with Discrete-Time Filters in Bluetooth and GSM Receivers

    Directory of Open Access Journals (Sweden)

    Ho Yo-Chuol

    2006-01-01

    Full Text Available RF circuits for multi-GHz frequencies have recently migrated to low-cost digital deep-submicron CMOS processes. Unfortunately, this process environment, which is optimized only for digital logic and SRAM memory, is extremely unfriendly for conventional analog and RF designs. We present fundamental techniques recently developed that transform the RF and analog circuit design complexity to digitally intensive domain for a wireless RF transceiver, so that it enjoys benefits of digital and switched-capacitor approaches. Direct RF sampling techniques allow great flexibility in reconfigurable radio design. Digital signal processing concepts are used to help relieve analog design complexity, allowing one to reduce cost and power consumption in a reconfigurable design environment. The ideas presented have been used in Texas Instruments to develop two generations of commercial digital RF processors: a single-chip Bluetooth radio and a single-chip GSM radio. We further present details of the RF receiver front end for a GSM radio realized in a 90-nm digital CMOS technology. The circuit consisting of low-noise amplifier, transconductance amplifier, and switching mixer offers dB dynamic range with digitally configurable voltage gain of 40 dB down to dB. A series of decimation and discrete-time filtering follows the mixer and performs a highly linear second-order lowpass filtering to reject close-in interferers. The front-end gains can be configured with an automatic gain control to select an optimal setting to form a trade-off between noise figure and linearity and to compensate the process and temperature variations. Even under the digital switching activity, noise figure at the 40 dB maximum gain is 1.8 dB and dBm IIP2 at the 34 dB gain. The variation of the input matching versus multiple gains is less than 1 dB. The circuit in total occupies 3.1 . The LNA, TA, and mixer consume less than mA at a supply voltage of 1.4 V.

  2. A salt water battery with high stability and charging rates made from solution processed conjugated polymers with polar side chains

    OpenAIRE

    Moia, Davide; Giovannitti, Alexander; Szumska, Anna A.; Schnurr, Martin; Rezasoltani, Elham; Maria, Iuliana P.; Barnes, Piers R. F.; McCulloch, Iain; Nelson, Jenny

    2017-01-01

    We report a neutral salt water based battery which uses p-type and n-type solution processed polymer films as the cathode and the anode of the cell. The specific capacity of the electrodes (approximately 30 mAh cm-3) is achieved via formation of bipolarons in both the p-type and n-type polymers. By engineering ethylene glycol and zwitterion based side chains attached to the polymer backbone we facilitate rapid ion transport through the non-porous polymer films. This, combined with efficient t...

  3. Self-focusing in processes of laser generation of highly-charged and high-energy heavy ions

    Czech Academy of Sciences Publication Activity Database

    Láska, Leoš; Jungwirth, Karel; Krása, Josef; Krouský, Eduard; Pfeifer, Miroslav; Rohlena, Karel; Ullschmied, Jiří; Badziak, J.; Parys, P.; Wolowski, J.; Gammino, S.; Torrisi, L.; Boody, F. P.

    2006-01-01

    Roč. 24, - (2006), s. 175-179 ISSN 0263-0346 R&D Projects: GA AV ČR IAA1010405; GA AV ČR KSK2043105 Grant - others:EU(XE) HPRI-1999-CT-00053; EU(XE) PALS/005; EU(XE) PALS/006 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : laser-plasma interactions * non-linear processes * self-focusing Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.958, year: 2006

  4. A nonconjugated radical polymer glass with high electrical conductivity

    Science.gov (United States)

    Joo, Yongho; Agarkar, Varad; Sung, Seung Hyun; Savoie, Brett M.; Boudouris, Bryan W.

    2018-03-01

    Solid-state conducting polymers usually have highly conjugated macromolecular backbones and require intentional doping in order to achieve high electrical conductivities. Conversely, single-component, charge-neutral macromolecules could be synthetically simpler and have improved processibility and ambient stability. We show that poly(4-glycidyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl), a nonconjugated radical polymer with a subambient glass transition temperature, underwent rapid solid-state charge transfer reactions and had an electrical conductivity of up to 28 siemens per meter over channel lengths up to 0.6 micrometers. The charge transport through the radical polymer film was enabled with thermal annealing at 80°C, which allowed for the formation of a percolating network of open-shell sites in electronic communication with one another. The electrical conductivity was not enhanced by intentional doping, and thin films of this material showed high optical transparency.

  5. Using resonant x-ray scattering to determine how structure controls the charge generation process in PCPDTBT:PC70BM solar cells

    Science.gov (United States)

    Pope, Michael; Waldrip, Matthew; Ferron, Thomas; Collins, Brian

    Increased solar power conversion efficiencies to 12% in bulk heterojunction organic photovoltaics (OPVs) continue to brighten their prospects as an economically viable source of solar energy. It is known that OPV performance can be enhanced through processing additives that change the nanostructure. We track these critical structure-property relationships in the OPV system PCPDTBT:PC70BM while varying the amount of DIO additive. Resonant Soft X-ray Scattering reveals domain purity, domain size, and molecular orientation to highlight the system's complex dependence on DIO concentration. We will show the effect the resulting structure has on charge generation and recombination via in-situ transient and steady state optoelectronic measurements. By measuring structure, excited state dynamics and device performance all on the same sample enables direct relationships to be measured. We show that the appropriate balance of crystallinity, domain size and domain purity are important for optimized excited state dynamics and device performance.

  6. Image Information Obtained Using a Charge-Coupled Device (CCD) Camera During an Immersion Liquid Evaporation Process for Measuring the Refractive Index of Solid Particles.

    Science.gov (United States)

    Niskanen, Ilpo; Sutinen, Veijo; Thungström, Göran; Räty, Jukka

    2018-06-01

    The refractive index is a fundamental physical property of a medium, which can be used for the identification and purity issues of all media. Here we describe a refractive index measurement technique to determine simultaneously the refractive index of different solid particles by monitoring the transmittance of light from a suspension using a charge-coupled device (CCD) camera. An important feature of the measurement is the liquid evaporation process for the refractive index matching of the solid particle and the immersion liquid; this was realized by using a pair of volatile and non-volatile immersion liquids. In this study, refractive indices of calcium fluoride (CaF 2 ) and barium fluoride (BaF 2 ) were determined using the proposed method.

  7. High-density carbon nanotube wet-laid buckypapers with enhanced strength and conductivity using a high-pressure homogenization process

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jun; Jang, Si Hoon; Park, No Hyung; Jeong, Won Young; Lim, Dae Young [Human and Culture Convergence Technology Group, Korea Institute of Industrial Technology (KITECH), Ansan (Korea, Republic of); Oh, Jun Young; Yang, Seung Jae [Dept. of Applied Organic Materials Engineering, Inha University, Incheon (Korea, Republic of)

    2017-04-15

    In this work, we prepared homogeneously dispersed carbon nanotubes in water using a high-pressure homogenizer, while high-density carbon nanotube buckypapers were prepared by wet-laid process. The strength and conductivity of the buckypaper were increased dramatically after the high-pressure homogenization because of the increased density and uniformity of the paper. In addition, the buckypapers containing various additives and treated with SOCl{sub 2} exhibited further increase of strength and conductivity resulting from the binding and the p-type doping effect. The buckypapers with high electrical conductivity exhibited superior electromagnetic interference shielding effectiveness that could be applied for structural shielding materials.

  8. Influence of controlled-charge anodization processes on the morphology of TiO2 nanotubes and their efficiency in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Vaenas, Naoum; Stergiopoulos, Thomas; Kontos, Athanassios G.; Likodimos, Vlassis; Falaras, Polycarpos

    2013-01-01

    The effect of the electrochemical anodization growth process on the development of self-organized TiO 2 nanotube (NT) films and their efficiency as photoelectrodes in dye sensitized solar cells (DSCs) has been comparatively investigated, by keeping constant the total anodization charge. Slow and rapid potentiostatic anodization processes were accordingly compared to the galvanostatic one, while a two step potentiostatic–galvanostatic technique was applied for the first time for the growth of TiO 2 NT arrays, as a step forward in relation to the existing potentiostatic–potentiostatic (P–P) technique. Scanning electron microscopy and Raman spectroscopy verified the wide diversity in the morphological and structural characteristics of the TiO 2 NTs obtained by the different anodization modes. The novel approach of galvanostatic tube growth on a potentiostatically patterned Ti foil provided the most uniform TiO 2 nanotubular films with clean top surface exempt of nanograss or cracks over extended areas. Evaluation of the TiO 2 NTs performance as photoelectrodes in DSC devices showed distinct differences of their electrical parameters that reflected finely the underlying structure/morphology variations of the different anodic oxidation conditions. Galvanostatic TiO 2 NT films presented the most favorable (open-ordered) structure for DSC photoelectrodes with superior electrical performance, essentially impaired by a relatively low fill factor that requires improvement by appropriate post-treatment. Furthermore, despite the marked differences in morphology, the TiO 2 NT photoelectrodes exhibited comparable overall performance (of the order of 4%), with only exception the P–P samples which presented slightly lower (about 25%) photovoltaic efficiency. These results indicate that the anodization charge is a critical factor that effectively controls the nanotubes behavior when they are used as photoelectrodes in DSCs

  9. Improved non-invasive method for aerosol particle charge measurement employing in-line digital holography

    Science.gov (United States)

    Tripathi, Anjan Kumar

    Electrically charged particles are found in a wide range of applications ranging from electrostatic powder coating, mineral processing, and powder handling to rain-producing cloud formation in atmospheric turbulent flows. In turbulent flows, particle dynamics is influenced by the electric force due to particle charge generation. Quantifying particle charges in such systems will help in better predicting and controlling particle clustering, relative motion, collision, and growth. However, there is a lack of noninvasive techniques to measure particle charges. Recently, a non-invasive method for particle charge measurement using in-line Digital Holographic Particle Tracking Velocimetry (DHPTV) technique was developed in our lab, where charged particles to be measured were introduced to a uniform electric field, and their movement towards the oppositely charged electrode was deemed proportional to the amount of charge on the particles (Fan Yang, 2014 [1]). However, inherent speckle noise associated with reconstructed images was not adequately removed and therefore particle tracking data was contaminated. Furthermore, particle charge calculation based on particle deflection velocity neglected the particle drag force and rebound effect of the highly charged particles from the electrodes. We improved upon the existing particle charge measurement method by: 1) hologram post processing, 2) taking drag force into account in charge calculation, 3) considering rebound effect. The improved method was first fine-tuned through a calibration experiment. The complete method was then applied to two different experiments, namely conduction charging and enclosed fan-driven turbulence chamber, to measure particle charges. In all three experiments conducted, the particle charge was found to obey non-central t-location scale family of distribution. It was also noted that the charge distribution was insensitive to the change in voltage applied between the electrodes. The range of voltage

  10. Light sensitive memristor with bi-directional and wavelength-dependent conductance control

    International Nuclear Information System (INIS)

    Maier, P.; Hartmann, F.; Emmerling, M.; Schneider, C.; Kamp, M.; Worschech, L.; Rebello Sousa Dias, M.; Castelano, L. K.; Marques, G. E.; Lopez-Richard, V.; Höfling, S.

    2016-01-01

    We report the optical control of localized charge on positioned quantum dots in an electro-photo-sensitive memristor. Interband absorption processes in the quantum dot barrier matrix lead to photo-generated electron-hole-pairs that, depending on the applied bias voltage, charge or discharge the quantum dots and hence decrease or increase the conductance. Wavelength-dependent conductance control is observed by illumination with red and infrared light, which leads to charging via interband and discharging via intraband absorption. The presented memristor enables optical conductance control and may thus be considered for sensory applications in artificial neural networks as light-sensitive synapses or optically tunable memories.

  11. Light sensitive memristor with bi-directional and wavelength-dependent conductance control

    Energy Technology Data Exchange (ETDEWEB)

    Maier, P.; Hartmann, F., E-mail: fabian.hartmann@physik.uni-wuerzburg.de; Emmerling, M.; Schneider, C.; Kamp, M.; Worschech, L. [Technische Physik and Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Physikalisches Institut, Universität Würzburg, Am Hubland, D-97074 Würzburg (Germany); Rebello Sousa Dias, M. [Departamento de Fisica, Universidade Federal de São Carlos, 13565-905 São Carlos, São Paulo (Brazil); Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Castelano, L. K.; Marques, G. E.; Lopez-Richard, V. [Departamento de Fisica, Universidade Federal de São Carlos, 13565-905 São Carlos, São Paulo (Brazil); Höfling, S. [Technische Physik and Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Physikalisches Institut, Universität Würzburg, Am Hubland, D-97074 Würzburg (Germany); SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS (United Kingdom)

    2016-07-11

    We report the optical control of localized charge on positioned quantum dots in an electro-photo-sensitive memristor. Interband absorption processes in the quantum dot barrier matrix lead to photo-generated electron-hole-pairs that, depending on the applied bias voltage, charge or discharge the quantum dots and hence decrease or increase the conductance. Wavelength-dependent conductance control is observed by illumination with red and infrared light, which leads to charging via interband and discharging via intraband absorption. The presented memristor enables optical conductance control and may thus be considered for sensory applications in artificial neural networks as light-sensitive synapses or optically tunable memories.

  12. Low-charge-state linac

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W.; Kim, J.W.

    1995-08-01

    A design is being developed for a low-charge-state linac suitable for injecting ATLAS with a low-charge-state, radioactive beam. Initial work indicates that the existing ATLAS interdigital superconducting accelerating structures, together with the superconducting quadrupole transverse focussing element discussed above, provides a basis for a high-performance low-charge-state linac. The initial 2 or 3 MV of such a linac could be based on a normally-conducting, low-frequency RFQ, possibly combined with 24-MHz superconducting interdigital structures. Beam dynamics studies of the whole low-charge-state post-accelerator section were carried out in early FY 1995.

  13. Pressure dependence of conductivity

    International Nuclear Information System (INIS)

    Bracewell, B.L.; Hochheimer, H.D.

    1993-01-01

    The overall objectives of this work were to attempt the following: (1) Measure the pressure dependence of the electrical conductivity of several quasi-one-dimensional, charge-density-wave solids, including measurements along various crystal directions. (2) Measure photocurrents in selected MX solids at ambient and elevated pressures. (3) Measure the resonance Raman spectra for selected MX solids as a function of pressure

  14. Global Positioning System data collection, processing, and analysis conducted by the U.S. Geological Survey Earthquake Hazards Program

    Science.gov (United States)

    Murray, Jessica R.; Svarc, Jerry L.

    2017-01-01

    The U.S. Geological Survey Earthquake Science Center collects and processes Global Positioning System (GPS) data throughout the western United States to measure crustal deformation related to earthquakes and tectonic processes as part of a long‐term program of research and monitoring. Here, we outline data collection procedures and present the GPS dataset built through repeated temporary deployments since 1992. This dataset consists of observations at ∼1950 locations. In addition, this article details our data processing and analysis procedures, which consist of the following. We process the raw data collected through temporary deployments, in addition to data from continuously operating western U.S. GPS stations operated by multiple agencies, using the GIPSY software package to obtain position time series. Subsequently, we align the positions to a common reference frame, determine the optimal parameters for a temporally correlated noise model, and apply this noise model when carrying out time‐series analysis to derive deformation measures, including constant interseismic velocities, coseismic offsets, and transient postseismic motion.

  15. Electrons in feldspar II: A consideration of the influence of conduction band-tail states on luminescence processes

    DEFF Research Database (Denmark)

    Poolton, H.R.J.; Ozanyan, K.B.; Wallinga, J.

    2002-01-01

    consider what influence the band tails have on the luminescence properties of feldspar, where electrons travel through the sample prior to recombination. The work highlights the dominant role that 0.04-0.05-eV phonons play in both the luminescence excitation and emission processes of these materials...

  16. Collaboration: a SWOT analysis of the process of conducting a review of nursing workforce policies in five European countries.

    Science.gov (United States)

    Uhrenfeldt, Lisbeth; Lakanmaa, Riitta-Liisa; Flinkman, Mervi; Basto, Marta Lima; Attree, Moira

    2014-05-01

    This paper critically reviews the literature on international collaboration and analyses the collaborative process involved in producing a nursing workforce policy analysis. Collaboration is increasingly promoted as a means of solving shared problems and achieving common goals; however, collaboration creates its own opportunities and challenges. Evidence about the collaboration process, its outcomes and critical success factors is lacking. A literature review and content analysis of data collected from six participants (from five European countries) members of the European Academy of Nursing Science Scholar Collaborative Workforce Workgroup, using a SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis template. Two major factors affecting scholarly collaboration were identified: Facilitators, which incorporated personal attributes and enabling contexts/mechanisms, including individual commitment, responsibility and teamwork, facilitative supportive structures and processes. The second, Barriers, incorporated unmet needs for funding; time; communication and impeding contexts/mechanisms, including workload and insufficient support/mentorship. The literature review identified a low level of evidence on collaboration processes, outcomes, opportunities and challenges. The SWOT analysis identified critical success factors, planning strategies and resources of effective international collaboration. Collaboration is an important concept for management. Evidence-based knowledge of the critical success factors facilitating and impeding collaboration could help managers make collaboration more effective. © 2012 John Wiley & Sons Ltd.

  17. On the influence of the processing conditions on the performance of electrically conductive carbon nanotube/polymer nanocomposites

    NARCIS (Netherlands)

    Grossiord, N.; Kivit, P.J.J.; Loos, J.; Meuldijk, J.; Kyrylyuk, A.V; Schoot, van der P.P.A.M.; Koning, C.E.

    2008-01-01

    We prepared multiwalled carbon nanotube/polystyrene (MWCNT/PS) nanocomposites using a latex-based process, the main step of which consists of directly mixing an aqueous suspension of exfoliated MWCNTs and a PS latex, both stabilized by an anionic surfactant. After freeze drying and compression

  18. Experiments on Dust Grain Charging

    Science.gov (United States)

    Abbas, M. N.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; West, E. A.

    2004-01-01

    Dust particles in various astrophysical environments are charged by a variety of mechanisms generally involving collisional processes with other charged particles and photoelectric emission with UV radiation from nearby sources. The sign and the magnitude of the particle charge are determined by the competition between the charging processes by UV radiation and collisions with charged particles. Knowledge of the particle charges and equilibrium potentials is important for understanding of a number of physical processes. The charge of a dust grain is thus a fundamental parameter that influences the physics of dusty plasmas, processes in the interplanetary medium and interstellar medium, interstellar dust clouds, planetary rings, cometary and outer atmospheres of planets etc. In this paper we present some results of experiments on charging of dust grains carried out on a laboratory facility capable levitating micron size dust grains in an electrodynamic balance in simulated space environments. The charging/discharging experiments were carried out by exposing the dust grains to energetic electron beams and UV radiation. Photoelectric efficiencies and yields of micron size dust grains of SiO2, and lunar simulates obtained from NASA-JSC will be presented.

  19. Coagulation of dielectric dust grains due to variable asymmetric charging

    International Nuclear Information System (INIS)

    Manweiler, Jerry W.; Armstrong, Thomas P.; Cravens, Thomas E.

    1998-01-01

    Observational evidence of electrical forces acting significantly on small solids is present for both the modern solar system in Saturn's rings and the ancient solar system in chondritic meteorites. It is likely that grain-grain coagulation rates are affected by the distribution of charges on small grains. Plasma particle impacts and photoelectric effects can provide the charges. It appears that some charging is inevitable and that plasma grain interactions need to be evaluated to determine the size of the effect on coagulation rates. We apply the results of our previous charging work to models of the protoplanetary nebula. It is expected that the protoplanetary nebula is weakly ionized except in certain instances and locations such as: solar flares in the interior, ultraviolet radiation at the outer boundary, and during enhanced luminosity of the star. Since the grains we study are non-conducting and show strong dipole moments in flowing plasma, we modify the geometric cross sections to include the effects of flowing plasma on non-conducting grains with plasma mediated shielding. This paper provides results showing how plasma flow affects the processes involved in charging the grains--total charge and charge distribution. We calculate the modifications to the cross sections and subsequent changes in the coagulation rates

  20. Highly transparent and conductive Al-doped ZnO nanoparticulate thin films using direct write processing

    International Nuclear Information System (INIS)

    Vunnam, S; Ankireddy, K; Kellar, J; Cross, W

    2014-01-01

    Solution processable Al-doped ZnO (AZO) thin films are attractive candidates for low cost transparent electrodes. We demonstrate here an optimized nanoparticulate ink for the fabrication of AZO thin films using scalable, low-cost direct write processing (ultrasonic spray deposition) in air at atmospheric pressure. The thin films were made via thermal processing of as-deposited films. AZO films deposited using the proposed nanoparticulate ink with further reducing in vacuum and rf plasma of forming gas exhibited optical transparency greater than 95% across the visible spectrum, and electrical resistivity of 0.5 Ω cm and it drops down to 7.0 × 10 −2 Ω cm after illuminating with UV light, which is comparable to commercially available tin doped indium oxide colloidal coatings. Various structural analyses were performed to investigate the influence of ink chemistry, deposition parameters, and annealing temperatures on the structural, optical, and electrical characteristics of the spray deposited AZO thin films. Optical micrographs confirmed the presence of surface defects and cracks using the AZO NPs ink without any additives. After adding N-(2-Aminoethyl)-3-aminopropylmethyldimethoxy silane to the ink, AZO films exhibited an optical transparency which was virtually identical to that of the plain glass substrate. (papers)