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Sample records for amorphous ge bipolar

  1. Parametrized dielectric functions of amorphous GeSn alloys

    Science.gov (United States)

    D'Costa, Vijay Richard; Wang, Wei; Schmidt, Daniel; Yeo, Yee-Chia

    2015-09-01

    We obtained the complex dielectric function of amorphous Ge1-xSnx (0 ≤ x ≤ 0.07) alloys using spectroscopic ellipsometry from 0.4 to 4.5 eV. Amorphous GeSn films were formed by room-temperature implantation of phosphorus into crystalline GeSn alloys grown by molecular beam epitaxy. The optical response of amorphous GeSn alloys is similar to amorphous Ge and can be parametrized using a Kramers-Kronig consistent Cody-Lorentz dispersion model. The parametric model was extended to account for the dielectric functions of amorphous Ge0.75Sn0.25 and Ge0.50Sn0.50 alloys from literature. The compositional dependence of band gap energy Eg and parameters associated with the Lorentzian oscillator have been determined. The behavior of these parameters with varying x can be understood in terms of the alloying effect of Sn on Ge.

  2. Early effect of SiGe heterojunction bipolar transistors

    Science.gov (United States)

    Xu, Xiao-Bo; Zhang, He-Ming; Hu, Hui-Yong; Qu, Jiang-Tao

    2012-06-01

    The standard Early voltage of the SGP model is generalized for SiGe NPN heterojunction bipolar transistors (HBTs). A new compact formulation of the Early voltage compatible with the SGP model is presented. The impact of the Ge profile on Early effect is shown and validated by experiments. The model can be applied to the SGP model for circuit simulation.

  3. Parametrized dielectric functions of amorphous GeSn alloys

    Energy Technology Data Exchange (ETDEWEB)

    D' Costa, Vijay Richard, E-mail: elevrd@nus.edu.sg; Wang, Wei; Yeo, Yee-Chia, E-mail: eleyeoyc@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583 (Singapore); Schmidt, Daniel [Singapore Synchrotron Light Source, National University of Singapore, Singapore 117603 (Singapore)

    2015-09-28

    We obtained the complex dielectric function of amorphous Ge{sub 1−x}Sn{sub x} (0 ≤ x ≤ 0.07) alloys using spectroscopic ellipsometry from 0.4 to 4.5 eV. Amorphous GeSn films were formed by room-temperature implantation of phosphorus into crystalline GeSn alloys grown by molecular beam epitaxy. The optical response of amorphous GeSn alloys is similar to amorphous Ge and can be parametrized using a Kramers-Kronig consistent Cody-Lorentz dispersion model. The parametric model was extended to account for the dielectric functions of amorphous Ge{sub 0.75}Sn{sub 0.25} and Ge{sub 0.50}Sn{sub 0.50} alloys from literature. The compositional dependence of band gap energy E{sub g} and parameters associated with the Lorentzian oscillator have been determined. The behavior of these parameters with varying x can be understood in terms of the alloying effect of Sn on Ge.

  4. Epitaxial growth of amorphous Ge films deposited on single-crystal Ge

    OpenAIRE

    M. G. Grimaldi; Mäenpää, M. (Markus); Paine, B. M.; Nicolet, M-A.; Lau, S. S.; Tseng, W. F.

    1981-01-01

    The epitaxial growth of amorphous Ge films deposited onto 110 Ge substrate is demonstrated. Substrate cleaning prior to deposition involves only conventional chemical procedures. The growth appears to be a strong function of the interface cleanliness. Two different growth mechanisms are observed: (a) a direct transition from amorphous to single-crystalline layer and (b) the growth involving the transition of amorphous to polycrystals to single crystal.

  5. Structural origin of resistance drift in amorphous GeTe

    Science.gov (United States)

    Zipoli, Federico; Krebs, Daniel; Curioni, Alessandro

    2016-03-01

    We used atomistic simulations to study the origin of the change of resistance over time in the amorphous phase of GeTe, a prototypical phase-change material (PCM). Understanding the cause of resistance drift is one of the biggest challenges to improve multilevel storage technology. For this purpose, we generated amorphous structures via classical molecular-dynamics simulations under conditions as close as possible to the experimental operating ones of such memory devices. Moreover, we used the replica-exchange technique to generate structures comparable with those obtained in the experiment after long annealing that show an increase of resistance. This framework allowed us to overcome the main limitation of previous simulations, based on density-functional theory, that suffered from being computationally too expensive therefore limited to the nanosecond time scale. We found that resistance drift is caused by consumption of Ge atom clusters in which the coordination of at least one Ge atom differs from that of the crystalline phase and by removal of stretched bonds in the amorphous network, leading to a shift of the Fermi level towards the middle of the band gap. These results show that one route to design better memory devices based on current chalcogenide alloys is to reduce the resistance drift by increasing the rigidity of the amorphous network.

  6. Amorphous inclusions during Ge and GeSn epitaxial growth via chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gencarelli, F., E-mail: federica.gencarelli@imec.be [imec, Kapeldreef 75, 3001 Leuven (Belgium); Dept. of Metallurgy and Materials Engineering, KU Leuven, B-3001 Leuven (Belgium); Shimura, Y. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Nuclear and Radiation Physics Section, KU Leuven, B-3001 Leuven (Belgium); Kumar, A. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Nuclear and Radiation Physics Section, KU Leuven, B-3001 Leuven (Belgium); Vincent, B.; Moussa, A.; Vanhaeren, D.; Richard, O.; Bender, H. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Vandervorst, W. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Nuclear and Radiation Physics Section, KU Leuven, B-3001 Leuven (Belgium); Caymax, M.; Loo, R. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Heyns, M. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Dept. of Metallurgy and Materials Engineering, KU Leuven, B-3001 Leuven (Belgium)

    2015-09-01

    In this work, we discuss the characteristics of particular island-type features with an amorphous core that are developed during the low temperature epitaxial growth of Ge and GeSn layers by means of chemical vapor deposition with Ge{sub 2}H{sub 6}. Although further investigations are needed to unambiguously identify the origin of these features, we suggest that they are originated by the formation of clusters of H and/or contaminants atoms during growth. These would initially cause the formation of pits with crystalline rough facets over them, resulting in ring-shaped islands. Then, when an excess surface energy is overcome, an amorphous phase would nucleate inside the pits and fill them. Reducing the pressure and/or increasing the growth temperature can be effective ways to prevent the formation of these features, likely due to a reduction of the surface passivation from H and/or contaminant atoms. - Highlights: • Island features with amorphous cores develop during low T Ge(Sn) CVD with Ge{sub 2}H{sub 6.} • These features are thoroughly characterized in order to understand their origin. • A model is proposed to describe the possible evolution of these features. • Lower pressures and/or higher temperatures avoid the formation of these features.

  7. Mechanical properties of bismuth implanted amorphous Ge film

    Energy Technology Data Exchange (ETDEWEB)

    Juhasz, A.; Szommer, P.; Lendvai, J.; Vertesy, Z.; Peto, G. E-mail: peto@mfa.kfki.hu

    1999-01-02

    Mechanical properties of Bi ion implanted a-Ge film were studied by dynamic microhardness tests and compared to those of unimplanted a-Ge film. 400 nm thick films were evaporated in units of 30 nm thick layers and bombarded with Bi ions at 60 keV energy and 2 {mu}A/cm{sup 2} current. Cyclic load-unload indentation tests and indentation creep tests were performed to determine the hardness and ductility of the ion implanted and unimplanted specimens, respectively. The brittleness of the materials was characterised by scanning electron microscopic observation of crack formation around the Vickers indentations. The dynamic hardness was much larger, the ductility lower, the crack formation was significantly larger in the case of the unimplanted than in the ion bombarded specimens. The observed differences in the mechanical properties indicate structural differences between the two types of a-Ge are in agreement with the earlier reported formation of a new amorphous phase of Ge induced by ion implantation (G. Peto, J. Kanski, U. Sodervall, Phys. Lett. 124 (1987) 510)

  8. Mechanical properties of bismuth implanted amorphous Ge film

    Science.gov (United States)

    Juhász, A.; Szommer, P.; Lendvai, J.; Vértesy, Z.; Pető, G.

    1999-01-01

    Mechanical properties of Bi ion implanted a-Ge film were studied by dynamic microhardness tests and compared to those of unimplanted a-Ge film. 400 nm thick films were evaporated in units of 30 nm thick layers and bombarded with Bi ions at 60 keV energy and 2 μA/cm 2 current. Cyclic load-unload indentation tests and indentation creep tests were performed to determine the hardness and ductility of the ion implanted and unimplanted specimens, respectively. The brittleness of the materials was characterised by scanning electron microscopic observation of crack formation around the Vickers indentations. The dynamic hardness was much larger, the ductility lower, the crack formation was significantly larger in the case of the unimplanted than in the ion bombarded specimens. The observed differences in the mechanical properties indicate structural differences between the two types of a-Ge are in agreement with the earlier reported formation of a new amorphous phase of Ge induced by ion implantation (G. Pető, J. Kanski, U. Sodervall, Phys. Lett. 124 (1987) 510 [6]).

  9. Anisotropic phase separation in amorphous Fe--Ge alloys

    International Nuclear Information System (INIS)

    Magnetron sputtered amorphous FexGe100-x films have been examined with anomalous small-angle x-ray scattering (ASAXS) in an attempt to characterize composition fluctuations which have been previously reported in this system. Films grown under various deposition conditions have been studied, with the scattering vector both in and oblique to the plane of the films, to search for anisotropy. By manipulating the deposited power flux and rates of growth, films which have the same composition can be grown to different states of phase separation. The total correlation functions have been calculated from the oblique scattering experiments. The anisotropy can be successfully modeled as a close-packing of oriented prolate ellipsoidal particles, with the elongated axis along the direction of film growth. A method for using these measurements to determine the compositions of the phase-separating species has been developed and utilized. The results indicate phase separation into a-Ge and a-FeGe2 for the a-FexGe100-x (x<33) alloy

  10. Molecular dynamics simulation of ion-beam-amorphization of Si, Ge and GaAs

    CERN Document Server

    Nord, J D; Keinonen, J

    2002-01-01

    We use molecular dynamics simulations to study ion-irradiation-induced amorphization in Si, Ge and GaAs using several different interatomic force models. We find that the coordination number is higher, and the average bond length longer, for the irradiated amorphous structures than for the molten ones in Si and Ge. For amorphous GaAs, we suggest that longer Ga-Ga bonds, also present in pure Ga, are produced during the irradiation. In Si the amorphization is found to proceed via growth of amorphous regions, and low energy recoils are found to induce athermal recrystallization during irradiation.

  11. Intrinsic complexity of the melt-quenched amorphous Ge2Sb2Te5 memory alloy

    Science.gov (United States)

    Krbal, M.; Kolobov, A. V.; Fons, P.; Tominaga, J.; Elliott, S. R.; Hegedus, J.; Uruga, T.

    2011-02-01

    Through the use of first-principles Ge K-edge XANES simulations we demonstrate that the structure of melt-quenched amorphous Ge-Sb-Te is intrinsically complex and is a mixture of Ge(3):Te(3) and Ge(4):Te(2) configurations in comparable concentrations, in contrast to the as-deposited amorphous phase that is dominated by the Ge(4):Te(2) configurations. The reasons for Ge-Te polyvalency are discussed and it is argued that both configurations are compatible with the Mott 8-N rule and the definition of an ideal amorphous solid. The near-perfect Te-Te distance match between the two major configurations accounts for the high cyclability of phase-change materials. Stable compositions in the Ge-Sb-Te system are suggested.

  12. Photoinduced effects in amorphous semiconductor Ge(S, Se)2 chalcogenide films

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The blue shift of optical transmittance edges were observed in amorphous semiconductor Ge(S, Se)2 chalcogenide films with light illumination. The shift in well-annealed films could be recovered by annealing the films near the glass-transition temperature again. The photocrystallization was also observed in amorphous Ge(S,Se)2 films with light illumination by the transmitting electron microscope measurement. The photoinduced phenomina of the amorphous Ge(S,Se)2 films could be applied to designing some new kinds of optical storage materials.

  13. Structure of amorphous Ag/Ge/S alloys: experimentally constrained density functional study

    Science.gov (United States)

    Akola, J.; Beuneu, B.; Jones, R. O.; Jóvári, P.; Kaban, I.; Kolář, J.; Voleská, I.; Wágner, T.

    2015-12-01

    Density functional/molecular dynamics simulations have been performed to determine structural and other properties of amorphous Ag/Ge/S and Ge/S alloys. In the former, the calculations have been combined with experimental data (x-ray and neutron diffraction, extended x-ray absorption fine structure). Ag/Ge/As alloys have high ionic conductivity and are among the most promising candidates for future memristor technology. We find excellent agreement between the experimental results and large-scale (500 atoms) simulations in Ag/Ge/S, and we compare and contrast the structures of Ge/S and Ag/Ge/S. The calculated electronic structures, vibrational densities of states, ionic mobilities, and cavity distributions of the amorphous materials are discussed and compared with data on crystalline phases where available. The high mobility of Ag in solid state electrolyte applications is related to the presence of cavities and can occur via jumps to a neighbouring vacant site.

  14. Nanostructuring of GeTiO amorphous films by pulsed laser irradiation

    Directory of Open Access Journals (Sweden)

    Valentin S. Teodorescu

    2015-04-01

    Full Text Available Laser pulse processing of surfaces and thin films is a useful tool for amorphous thin films crystallization, surface nanostructuring, phase transformation and modification of physical properties of thin films. Here we show the effects of nanostructuring produced at the surface and under the surface of amorphous GeTiO films through laser pulses using fluences of 10–30 mJ/cm2. The GeTiO films were obtained by RF magnetron sputtering with 50:50 initial atomic ratio of Ge:TiO2. Laser irradiation was performed by using the fourth harmonic (266 nm of a Nd:YAG laser. The laser-induced nanostructuring results in two effects, the first one is the appearance of a wave-like topography at the film surface, with a periodicity of 200 nm and the second one is the structure modification of a layer under the film surface, at a depth that is related to the absorption length of the laser radiation. The periodicity of the wave-like relief is smaller than the laser wavelength. In the modified layer, the Ge atoms are segregated in spherical amorphous nanoparticles as a result of the fast diffusion of Ge atoms in the amorphous GeTiO matrix. The temperature estimation of the film surface during the laser pulses shows a maximum of about 500 °C, which is much lower than the melting temperature of the GeTiO matrix. GeO gas is formed at laser fluences higher than 20 mJ/cm2 and produces nanovoids in the laser-modified layer at the film surface. A glass transition at low temperatures could happen in the amorphous GeTiO film, which explains the formation of the wave-like topography. The very high Ge diffusivity during the laser pulse action, which is characteristic for liquids, cannot be reached in a viscous matrix. Our experiments show that the diffusivity of atomic and molecular species such as Ge and GeO is very much enhanced in the presence of the laser pulse field. Consequently, the fast diffusion drives the formation of amorphous Ge nanoparticles through the

  15. Early effect modeling of silicon-on-insulator SiGe heterojunction bipolar transistors

    Institute of Scientific and Technical Information of China (English)

    Xu Xiao-Bo; Zhang He-Ming; Hu Hui-Yong; Ma Jian-Li

    2011-01-01

    Silicon germanium (SiGe) heterojunction bipolar transistor (HBT) on thin silicon-on-insulator (SOI) has recently been demonstrated and integrated into the latest SOI BiCMOS technology. The Early effect of the SOI SiGe HBT is analysed considering vertical and horizontal collector depletion, which is different from that of a bulk counterpart. A new compact formula of the Early voltage is presented and validated by an ISE TCAD simulation. The Early voltage shows a kink with the increase of the reverse base-collector bias. Large differences are observed between SOI devices and their bulk counterparts. The presented Early effect model can be employed for a fast evaluation of the Early voltage and is useful to the design, the simulation and the fabrication of high performance SOI SiGe devices and circuits.

  16. Direct observation of Ag filament growth and unconventional SET-RESET operation in GeTe amorphous films

    Science.gov (United States)

    Imanishi, Yusuke; Kida, Shimon; Nakaoka, Toshihiro

    2016-07-01

    We report on the direct observation of Ag filament growth and a peculiar resistance switching in amorphous GeTe films with a lateral electrode geometry. The Ag filament growth was monitored by in-situ optical microscopy. The resistance switching was studied in three electrode pairs, Ag-Ag, Pt-Ag, and Pt-Ag/Pt (Ag electrode covered with Pt). In all the three electrode pairs, similar dendritic Ag filaments were clearly observed growing along both directions from one electrode to the other, according to the applied bias polarity. However, the SET and RESET processes are quite different. The Ag-Ag pair produces a unipolar clockwise switching. The Pt-Ag pair shows a bipolar counter-clockwise switching, as predicted in the basic electrochemical metallization theory, but the observed switching polarity is exactly opposite to the basic theory prediction. The Pt-Ag/Pt pair produces a unipolar counter-clockwise switching. The peculiar SET/RESET processes are explained on the basis of strong Ag diffusion into GeTe matrix resulting in an asymmetric effective electrode pair. The findings suggest that the SET/RESET processes are controlled by the amount of Ag and the electrode geometry.

  17. Structural studies of the phase separation of amorphous FexGe100-x alloys

    Science.gov (United States)

    Lorentz, Robert D.; Bienenstock, Arthur; Morrison, Timothy I.

    1994-02-01

    Small-angle x-ray scattering and x-ray-absorption near-edge spectroscopy (XANES) experiments have been performed on amorphous FexGe100-x alloys over the composition range 0Janot for the related FexSn100-x system. This phase separation explains the Mossbauer observation of ``magnetic'' and ``nonmagnetic'' Fe atoms in these alloys.

  18. Heat capacity of amorphous and disordered Nb3Ge thin films

    International Nuclear Information System (INIS)

    Heat capacity measurements on 1000 to 1500A thick amorphous Nb3Ge and granular Al films have been carried out using an ac technique. The major goal of the experiment was to study the effect of thermal fluctuations, both above and below the superconducting transition temperature T/sub c/, in dirty, short meanfree path materials

  19. Amorphous Ge quantum dots embedded in crystalline Si: ab initio results

    International Nuclear Information System (INIS)

    We study amorphous Ge quantum dots embedded in a crystalline Si matrix through structure modeling and simulation using ab initio density functional theory including spin–orbit interaction and quasiparticle effects. Three models are generated by replacing a spherical region within diamond Si by Ge atoms and creating a disordered bond network with appropriate density inside the Ge quantum dot. After total-energy optimisations of the atomic geometry we compute the electronic and optical properties. We find three major effects: (i) the resulting nanostructures adopt a type-I heterostructure character; (ii) the lowest optical transitions occur only within the Ge quantum dots, and do not involve or cross the Ge–Si interface. (iii) for larger amorphous Ge quantum dots, with diameters of about 2.0 and 2.7 nm, absorption peaks appear in the mid-infrared spectral region. These are promising candidates for intense luminescence at photon energies below the gap energy of bulk Ge. (paper)

  20. Nanocrystals and amorphous matrix phase studies of Finemet-like alloys containing Ge

    Energy Technology Data Exchange (ETDEWEB)

    Moya, J.A., E-mail: jmoya.fi.uba@gmail.co [IESIING, Facultad de Ingenieria e Informatica, UCASAL, A4402FYP Salta (Argentina); Lab. Solidos Amorfos, Facultad de Ingenieria, INTECIN, UBA-CONICET (Argentina); CONICET (Argentina)

    2010-07-15

    Two simple models were developed in order to determine the chemical composition of both nanocrystals and intergranular amorphous phases in nanocrystallized Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} containing Ge using data from X-ray diffraction and Moessbauer spectroscopy techniques. Saturation magnetization of the amorphous intergranular matrix (M{sub s}{sup am}) was calculated considering the contribution of the alpha-Fe(Si,Ge) nanocrystals and saturation magnetization of the alloys. The behavior of M{sub s}{sup am} with the iron content of the matrix was obtained and discussed. The exchange stiffness constant for the nanograins and for the amorphous phases was determined. The increment in the coercive field (H{sub c}) with increasing Ge content was evaluated using two theoretical models for the random magnetocrystalline anisotropy constant (). Results show that the magnetic hardening observed could not be attributed to an increase in but mainly to an important increment of the magnetostriction constant of the alpha-Fe(Si,Ge) nanocrystals (lambda{sub s}{sup cr}). Values for lambda{sub s}{sup cr} are proposed.

  1. Tracks and voids in amorphous Ge induced by swift heavy-ion irradiation.

    Science.gov (United States)

    Ridgway, M C; Bierschenk, T; Giulian, R; Afra, B; Rodriguez, M D; Araujo, L L; Byrne, A P; Kirby, N; Pakarinen, O H; Djurabekova, F; Nordlund, K; Schleberger, M; Osmani, O; Medvedev, N; Rethfeld, B; Kluth, P

    2013-06-14

    Ion tracks formed in amorphous Ge by swift heavy-ion irradiation have been identified with experiment and modeling to yield unambiguous evidence of tracks in an amorphous semiconductor. Their underdense core and overdense shell result from quenched-in radially outward material flow. Following a solid-to-liquid phase transformation, the volume contraction necessary to accommodate the high-density molten phase produces voids, potentially the precursors to porosity, along the ion direction. Their bow-tie shape, reproduced by simulation, results from radially inward resolidification. PMID:25165936

  2. Tuning the properties of Ge-quantum dots superlattices in amorphous silica matrix through deposition conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, S. [University of Minho, Portugal; Roldan Gutierrez, Manuel A [ORNL; Ramos, M. M.D. [University of Minho, Portugal; Gomes, M.J.M. [University of Minho, Portugal; Molina, S. I. [Universidad de Cadiz, Spain; Pennycook, Stephen J [ORNL; Varela del Arco, Maria [ORNL; Buljan, M. [R. Boskovic Institute, Zagreb, Croatia; Barradas, N. [Instituto Tecnologico e Nuclear (ITN), Lisbon, Portugal; Alves, E. [Instituto Tecnologico e Nuclear (ITN), Lisbon, Portugal; Chahboun, A. [FST Tanger, Morocco; Bernstorff, S. [Sincrotrone Trieste, Basovizza, Italy

    2012-01-01

    In this work, we investigate the structural properties of Ge quantum dot lattices in amorphous silica matrix, prepared by low-temperature magnetron sputtering deposition of (Ge+SiO{sub 2})/SiO{sub 2} multilayers. The dependence of quantum dot shape, size, separation, and arrangement type on the Ge-rich (Ge + SiO{sub 2}) layer thickness is studied. We show that the quantum dots are elongated along the growth direction, perpendicular to the multilayer surface. The size of the quantum dots and their separation along the growth direction can be tuned by changing the Ge-rich layer thickness. The average value of the quantum dots size along the lateral (in-plane) direction along with their lateral separation is not affected by the thickness of the Ge-rich layer. However, the thickness of the Ge-rich layer significantly affects the quantum dot ordering. In addition, we investigate the dependence of the multilayer average atomic composition and also the quantum dot crystalline quality on the deposition parameters.

  3. Study of Cutoff Frequency of High Collector Current Density in SiGe Single-Heterojunction Bipolar Transistor

    Directory of Open Access Journals (Sweden)

    G. M. Khanduri

    2004-01-01

    Full Text Available The cutoff frequency performance of an NPN Si/SiGe/SiGe Single-heterojunction bipolar transistor (SiGe SHBT at high collector current densities has been analyzed using a 2-dimensional MEDICI device simulator. A conventional NPN Si/SiGe/Si Double-heterojunction bipolar transistor (SiGe DHBT having uniform 14%Ge in the base region has been investigated for comparison. The analysis shows the formation of a retarding potential barrier for minority carrier electrons at the basecollector heterojunction of the DHBT structure. Whereas, the base-collector homojunction of the SiGe SHBT structure, having a uniform 14%Ge profile in its base and collector, inhibits the formation of such a retarding potential barrier. The SHBT structure with a base-collector homojunction shows an Improved cutoff frequency at a high collector current density in comparison with conventional SiGe DHBT, which makes it more promising for high speed, scaled down, field-specific applications.

  4. The Relationship between Nanocluster Precipitation and Thermal Conductivity in Si/Ge Amorphous Multilayer Films: Effects of Cu Addition

    OpenAIRE

    Ahmad Ehsan Mohd Tamidi; Yasushi Sasajima

    2016-01-01

    We have used a molecular dynamics technique to simulate the relationship between nanocluster precipitation and thermal conductivity in Si/Ge amorphous multilayer films, with and without Cu addition. In the study, the Green-Kubo equation was used to calculate thermal conductivity in these materials. Five specimens were prepared: Si/Ge layers, Si/(Ge + Cu) layers, (Si + Cu)/(Ge + Cu) layers, Si/Cu/Ge/Cu layers, and Si/Cu/Ge layers. The number of precipitated nanoclusters in these specimens, whi...

  5. Effect of doping and stoichiometric profile on transport in SiGe heterojunction bipolar transistor

    Science.gov (United States)

    Halilov, S.

    2016-09-01

    Based on analytical consideration and numerical simulations, it is shown how the mutually adjusted doping and stoichiometric profile results in improved frequency response and current gain in Si1-x Ge x -based heterojunction bipolar transistor. The closed-form expressions are derived for the dopant distribution within a certain mobility model which is parametrized in terms of the impurity concentration and stoichiometric grading on the same footing. With proper parametrization of the mobility, the method is suitable in both limits of high alloy scattering/low crystal ordering and low alloy scattering/highly ordered stoichiometrically graded structure. The work is corroborated by device simulations of a single-side HBT 30% stoichiometrically graded base, with detailed IV-curve, Gummel and AC analysis. It is shown that the distinct impurity distribution results in a reduced space-charge region, contributes to an effective electric field assisting the diffusion of the minority carriers and results in the saturation current density increased by 50%, the AC gain increased by 90%, the four-fold increase of the DC current gain, and improves the transition frequency from 274 to 358 GHz as compared to the case of the uniformly distributed acceptors. The obtained results may serve as a practical guide in design of highly-graded heterojunction bipolar transistors with efficient frequency response, high gain and enhanced power.

  6. Formation of nano-porous GeOx by de-alloying of an Al–Ge–Mn amorphous alloy

    International Nuclear Information System (INIS)

    The present study shows that nanometer-scale amorphous phase separation occurs by spinodal decomposition of the undercooled liquid in a melt-spun Al60Ge30Mn10 alloy, although there is no atomic pair with positive enthalpy of mixing. By adopting a proper de-alloying process, an interconnected nano-porous germanium oxide with an amorphous structure is successfully synthesized. The present study shows that nano-porous amorphous germanium oxide can be easily obtained by de-alloying of Al-based amorphous alloys with nm-scale composition fluctuation

  7. Heterogeneous nucleation of the amorphous phase and dissolution of nanocrystalline grains in bilayer Al-Ge thin films

    Energy Technology Data Exchange (ETDEWEB)

    Raghavan, G.; Divakar, R.; Sundari, T.; Sundararaman, D.; Tyagi, A.K.; Krishan, K. [Indira Gandhi Center for Atomic Research, Kalpakkam (India)

    1997-12-18

    Solid State Amorphization Reaction (SSAR) was first reported in thin film couples of Au-La by Schwarz et al. Since then, many other systems have been shown to undergo SSAR. Various issues involved in SSAR have been extensively investigated and reviewed. The existence of a large negative heat of mixing, anomalous fast diffusion of one component, the requirement of heterogeneous nucleation sites such as grain boundaries are found to be some of the key features of solid state amorphization. The authors present in this paper evidence of heterogeneous nucleation and growth of the amorphous phase followed by the precipitation of germanium from the amorphous phase in Al-Ge bilayer films.

  8. Enhanced Au induced lateral crystallization in electron-irradiated amorphous Ge on SiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Sakiyama, Shin; Kaneko, Takahiro; Ootsubo, Takanobu; Sakai, Takatsugu; Nakashima, Kazutoshi; Moto, Kenta; Yoneoka, Masashi; Takakura, Kenichiro; Tsunoda, Isao, E-mail: isao_tsunoda@kumamoto-nct.ac.jp

    2014-04-30

    We have investigated the low temperature of Au induced lateral crystallization of electron irradiated amorphous Ge on SiO{sub 2}/Si substrate. The reduction of the critical annealing time to cause the Au induced lateral crystallization is realized by high energy electron irradiation. In addition, the lateral crystallization region of the sample with electron irradiation has high crystalline quality as well as the sample without electron irradiation. We have speculated that the Au induced lateral crystallization of amorphous Ge on SiO{sub 2}/Si substrate was enhanced by electron irradiation, due to the introduction of point defects into amorphous Ge able to diffuse easily of Au atoms. - Highlights: • Au induced lateral crystallization of electron irradiated Ge is investigated. • Crystallization annealing time is significantly reduced. • High crystalline quality of lateral region was not changed by electron irradiation.

  9. Atomic mobility in the overheated amorphous GeTe compound for phase change memories

    International Nuclear Information System (INIS)

    Abstractauthoren Phase change memories rest on the ability of some chalcogenide alloys to undergo a fast and reversible transition between the crystalline and amorphous phases upon Joule heating. The fast crystallization is due to a high nucleation rate and a large crystal growth velocity which are actually possible thanks to the fragility of the supercooled liquid that allows for the persistence of a high atomic mobility at high supercooling where the thermodynamical driving force for crystallization is also high. Since crystallization in the devices occurs by rapidly heating the amorphous phase, hysteretic effects might arise with a different diffusion coefficient and viscosity on heating than on cooling. In this work, we have quantified these hysteretic effects in the phase change compound GeTe by means of molecular dynamics simulations. The atomic mobility in the overheated amorphous phase is lower than in supercooled liquid at the same temperature and the viscosity is consequently higher. Still, the simulations of the overheated amorphous phase reveal a breakdown of the Stokes-Einstein relation between the diffusion coefficient and the viscosity, similarly to what we found previously in the supercooled liquid. Evidences are provided that the breakdown is due to the emergence of dynamical heterogeneities at high supercooling. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Atomic mobility in the overheated amorphous GeTe compound for phase change memories

    Energy Technology Data Exchange (ETDEWEB)

    Sosso, G.C. [Dipartimento di Scienza dei Materiali, Universita di Milano-Bicocca, Via R. Cozzi 55, 20125 Milano (Italy); Thomas Young Centre and Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom); London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH (United Kingdom); Behler, J. [Lehrstuhl fuer Theoretische Chemie, Ruhr-Universitaet Bochum, Universitaetsstrasse 150, 44780 Bochum (Germany); Bernasconi, M. [Dipartimento di Scienza dei Materiali, Universita di Milano-Bicocca, Via R. Cozzi 55, 20125 Milano (Italy)

    2016-02-15

    Abstractauthoren Phase change memories rest on the ability of some chalcogenide alloys to undergo a fast and reversible transition between the crystalline and amorphous phases upon Joule heating. The fast crystallization is due to a high nucleation rate and a large crystal growth velocity which are actually possible thanks to the fragility of the supercooled liquid that allows for the persistence of a high atomic mobility at high supercooling where the thermodynamical driving force for crystallization is also high. Since crystallization in the devices occurs by rapidly heating the amorphous phase, hysteretic effects might arise with a different diffusion coefficient and viscosity on heating than on cooling. In this work, we have quantified these hysteretic effects in the phase change compound GeTe by means of molecular dynamics simulations. The atomic mobility in the overheated amorphous phase is lower than in supercooled liquid at the same temperature and the viscosity is consequently higher. Still, the simulations of the overheated amorphous phase reveal a breakdown of the Stokes-Einstein relation between the diffusion coefficient and the viscosity, similarly to what we found previously in the supercooled liquid. Evidences are provided that the breakdown is due to the emergence of dynamical heterogeneities at high supercooling. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Structural change upon annealing of amorphous GeSbTe grown on Si(111)

    Energy Technology Data Exchange (ETDEWEB)

    Bragaglia, V., E-mail: bragaglia@pdi-berlin.de; Jenichen, B.; Giussani, A.; Perumal, K.; Riechert, H.; Calarco, R. [Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2014-08-07

    The structural change upon annealing of an amorphous GeSbTe (GST) film deposited by molecular beam epitaxy on a Si(111) substrate is studied by means of X-ray diffraction (XRD), X-ray reflectivity (XRR), and atomic force microscopy (AFM). XRD profiles reveal that both metastable cubic and stable hexagonal phases are obtained with a single out-of-plane orientation. XRR study shows a density increase and consequent thickness decrease upon annealing, in accordance with literature. From both, the XRD and the AFM study, it emerges that the crystalline substrate acts as a template for the film, favoring the crystallization of the amorphous GST into the [111] oriented metastable cubic phase, and the latter turns into the [0001] stable hexagonal phase for higher annealing temperature.

  12. Impact of defect occupation on conduction in amorphous Ge2Sb2Te5

    Science.gov (United States)

    Kaes, Matthias; Salinga, Martin

    2016-08-01

    Storage concepts employing the resistance of phase-change memory (PRAM) have matured in recent years. Attempts to model the conduction in the amorphous state of phase-change materials dominating the resistance of PRAM devices commonly invoke a connection to the electronic density-of-states (DoS) of the active material in form of a “distance between trap states s”. Here, we point out that s depends on the occupation of defects and hence on temperature. To verify this, we numerically study how the occupation in the DoS of Ge2Sb2Te5 is affected by changes of temperature and illumination. Employing a charge-transport model based on the Poole-Frenkel effect, we correlate these changes to the field- and temperature-dependent current-voltage characteristics of lateral devices of amorphous Ge2Sb2Te5, measured in darkness and under illumination. In agreement with our calculations, we find a pronounced temperature-dependence of s. As the device-current depends exponentially on the value of s, accounting for its temperature-dependence has profound impact on device modeling.

  13. PLD Preparation of GeS6 Amorphous Film and Investigation on Its Photo-induced Darkening Phenomenon

    Institute of Scientific and Technical Information of China (English)

    LIU Gang; GU Shaoxuan; ZHANG Haochun; ZHANG Ning; TAO Haizheng

    2014-01-01

    GeS6 chalcogenide amorphous film was deposited on glass substrate via PLD (pulsed laser deposition) technique. The performance and structure of the film was characterized by XRD (X-ray diffraction), SEM (Scanning Electron Microscopy), EDS (Energy Dispersive Spectroscopy), optical transmission spectra, and Raman spectra, etc. The GeS6 amorphous film was irradiated by 532 nm linearly polarized light, and its photo-induced darkening was investigated. The results showed that the GeS6 chalcogenide amorphous film was smooth and compact with uniform thickness and combined with the substrate firmly, and its chemical composition was in consistency with the bulky target. When laser energy was fixed, the transparence of the film declined with the increase of the laser irradiation time. Obvious photo-induced darkening and relaxation phenomenon of the film after laser irradiation were observed in this investigation.

  14. Substrate bias effects on collector resistance in SiGe heterojunction bipolar transistors on thin film silicon-on-insulator

    Institute of Scientific and Technical Information of China (English)

    Xu Xiao-Bo; Zhang He-Ming; Hu Hui-Yong; Qu Jiang-Tao

    2011-01-01

    An analytical expression for the collector resistance of a novel vertical SiGe heteroj unction bipolar transistor (HBT)on thin film silicon-on-insulator (SOI) is obtained with the substrate bias effects being considered. The resistance is found to decrease slowly and then quickly and to have kinks with the increase of the substrate-collector bias, which is quite different from that of a conventional bulk HBT. The model is consistent with the simulation result and the reported data and is useful to the frequency characteristic design of 0.13 μm millimeter-wave SiGe SOI BiCMOS devices.

  15. Long-Term Reliability of High Speed SiGe/Si Heterojunction Bipolar Transistors

    Science.gov (United States)

    Ponchak, George E. (Technical Monitor); Bhattacharya, Pallab

    2003-01-01

    Accelerated lifetime tests were performed on double-mesa structure Si/Si0.7Ge0.3/Si npn heterojunction bipolar transistors, grown by molecular beam epitaxy, in the temperature range of 175C-275C. Both single- and multiple finger transistors were tested. The single-finger transistors (with 5x20 micron sq m emitter area) have DC current gains approximately 40-50 and f(sub T) and f(sub MAX) of up to 22 GHz and 25 GHz, respectively. The multiple finger transistors (1.4 micron finger width, 9 emitter fingers with total emitter area of 403 micron sq m) have similar DC current gain but f(sub T) of 50 GHz. It is found that a gradual degradation in these devices is caused by the recombination enhanced impurity diffusion (REID) of boron atoms from the p-type base region and the associated formation of parasitic energy barriers to electron transport from the emitter to collector layers. This REID has been quantitatively modeled and explained, to the first order of approximation, and the agreement with the measured data is good. The mean time to failure (MTTF) of the devices at room temperature is estimated from the extrapolation of the Arrhenius plots of device lifetime versus reciprocal temperature. The results of the reliability tests offer valuable feedback for SiGe heterostructure design in order to improve the long-term reliability of the devices and circuits made with them. Hot electron induced degradation of the base-emitter junction was also observed during the accelerated lifetime testing. In order to improve the HBT reliability endangered by the hot electrons, deuterium sintered techniques have been proposed. The preliminary results from this study show that a deuterium-sintered HBT is, indeed, more resistant to hot-electron induced base-emitter junction degradation. SiGe/Si based amplifier circuits were also subjected to lifetime testing and we extrapolate MTTF is approximately 1.1_10(exp 6) hours at 125iC junction temperature from the circuit lifetime data.

  16. Top electrode material related bipolar memory and unipolar threshold resistance switching in amorphous Ta2O5 films

    Science.gov (United States)

    Cai, Yunyu; Sheng, Cuicui; Liang, Changhao

    2013-06-01

    Tantalum oxide (Ta2O5) is one of the most studied materials for its stable resistance switching and potential application in nonvolatile memory devices. Top electrode and essential switching material are two critical points dominating its switching characteristics. Here, Ta2O5 films of amorphous nature (a-Ta2O5) with tunable thicknesses were made by changing the applied voltage during anodic oxidation of Ta-metal foils. The resistance-switching behavior of an a-Ta2O5 film in a metal/a-Ta2O5/Ta configuration was investigated by using a sputtered W or Ag metal film as the top electrode. The unipolar threshold switching phenomenon was observed using W as top electrode (WTE), while bipolar switching behaviors were achieved using active Ag metal as top electrode (AgTE). The thickness of the a-Ta2O5 film shows an obvious effect on the SET voltage in a WTE/a-Ta2O5/Ta device. The interfacial redox reaction induced formation of more conductive Ta-rich suboxide and the Joule heating effect are proposed to contribute to the unipolar threshold switching behavior. It is also suggested that the bipolar switching could have resulted from the electrochemical reaction-induced dissolution and growth of Ag conducting channels inside the Ta2O5 films.

  17. Thermal stability improvement of a multiple finger power SiGe heterojunction bipolar transistor under different power dissipations using non-uniform finger spacing

    Institute of Scientific and Technical Information of China (English)

    Chen Liang; Zhang Wan-Rong; Jin Dong-Yue; Shen Pei; Xie Hong-Yun; Ding Chun-Bao; Xiaa Ying; Sun Bo-Tao; Wang Ren-Qing

    2011-01-01

    method of non-uniform finger spacing is proposed to enhance thermal stability of a multiple finger power SiGe hererojunction bipolar transistor under different power dissipations. Temperature distribution on the emitter fingers of a multi-finger SiGe heterojunction bipolar transistor is studied using a numerical electro-thermal model. The results show that the SiGe heterojunction bipolar transistor with non-uniform finger spacing has a small temperature difference between fingers compared with a traditional uniform finger spacing heterojunction bipolar transistor at the same power dissipation. What is most important is that the ability to improve temperature non-uniformity is not weakened as power dissipation increases. So the method of non-uniform finger spacing is very effective in enhancing the thermal stability and the power handing capability of power device. Experimental results verify our conclusious.

  18. Amorphous GeOx-Coated Reduced Graphene Oxide Balls with Sandwich Structure for Long-Life Lithium-Ion Batteries.

    Science.gov (United States)

    Choi, Seung Ho; Jung, Kyeong Youl; Kang, Yun Chan

    2015-07-01

    Amorphous GeOx-coated reduced graphene oxide (rGO) balls with sandwich structure are prepared via a spray-pyrolysis process using polystyrene (PS) nanobeads as sacrificial templates. This sandwich structure is formed by uniformly coating the exterior and interior of few-layer rGO with amorphous GeOx layers. X-ray photoelectron spectroscopy analysis reveals a Ge:O stoichiometry ratio of 1:1.7. The amorphous GeOx-coated rGO balls with sandwich structure have low charge-transfer resistance and fast Li(+)-ion diffusion rate. For example, at a current density of 2 A g(-1), the GeOx-coated rGO balls with sandwich and filled structures and the commercial GeO2 powders exhibit initial charge capacities of 795, 651, and 634 mA h g(-1), respectively; the corresponding 700th-cycle charge capacities are 758, 579, and 361 mA h g(-1). In addition, at a current density of 5 A g(-1), the rGO balls with sandwich structure have a 1600th-cycle reversible charge capacity of 629 mA h g(-1) and a corresponding capacity retention of 90.7%, as measured from the maximum reversible capacity at the 100th cycle.

  19. Amorphous GeOx-Coated Reduced Graphene Oxide Balls with Sandwich Structure for Long-Life Lithium-Ion Batteries.

    Science.gov (United States)

    Choi, Seung Ho; Jung, Kyeong Youl; Kang, Yun Chan

    2015-07-01

    Amorphous GeOx-coated reduced graphene oxide (rGO) balls with sandwich structure are prepared via a spray-pyrolysis process using polystyrene (PS) nanobeads as sacrificial templates. This sandwich structure is formed by uniformly coating the exterior and interior of few-layer rGO with amorphous GeOx layers. X-ray photoelectron spectroscopy analysis reveals a Ge:O stoichiometry ratio of 1:1.7. The amorphous GeOx-coated rGO balls with sandwich structure have low charge-transfer resistance and fast Li(+)-ion diffusion rate. For example, at a current density of 2 A g(-1), the GeOx-coated rGO balls with sandwich and filled structures and the commercial GeO2 powders exhibit initial charge capacities of 795, 651, and 634 mA h g(-1), respectively; the corresponding 700th-cycle charge capacities are 758, 579, and 361 mA h g(-1). In addition, at a current density of 5 A g(-1), the rGO balls with sandwich structure have a 1600th-cycle reversible charge capacity of 629 mA h g(-1) and a corresponding capacity retention of 90.7%, as measured from the maximum reversible capacity at the 100th cycle. PMID:26047208

  20. The Relationship between Nanocluster Precipitation and Thermal Conductivity in Si/Ge Amorphous Multilayer Films: Effects of Cu Addition

    Directory of Open Access Journals (Sweden)

    Ahmad Ehsan Mohd Tamidi

    2016-01-01

    Full Text Available We have used a molecular dynamics technique to simulate the relationship between nanocluster precipitation and thermal conductivity in Si/Ge amorphous multilayer films, with and without Cu addition. In the study, the Green-Kubo equation was used to calculate thermal conductivity in these materials. Five specimens were prepared: Si/Ge layers, Si/(Ge + Cu layers, (Si + Cu/(Ge + Cu layers, Si/Cu/Ge/Cu layers, and Si/Cu/Ge layers. The number of precipitated nanoclusters in these specimens, which is defined as the number of four-coordinate atoms, was counted along the lateral direction of the specimens. The observed results of precipitate formation were considered in relation to the thermal conductivity results. Enhancement of precipitation of nanoclusters by Cu addition, that is, densification of four-coordinate atoms, can prevent the increment of thermal conductivity. Cu dopant increases the thermal conductivity of these materials. Combining these two points, we concluded that Si/Cu/Ge is the best structure to improve the conversion efficiency of the Si/Ge amorphous multilayer films.

  1. History dependent vortex configurations in superconducting disks of amorphous MoGe

    International Nuclear Information System (INIS)

    We have investigated spatial configurations of vortices in superconducting disks of amorphous MoGe as a function of field history. Employing a scanning SQUID microscope technique, we observe quasi-symmetric distributions of the vortices imposed by the disk geometry. For a field cool measurement, a single vortex state appears after the Meissner state and it is followed by multi-vortex states at higher fields. In a zero field cool (ZFC) measurement, however, different behaviors are observed. On increasing magnetic field, the Meissner state switches directly to the multi-vortex state without showing the single vortex state. The corresponding magnetization curves of the disks are strikingly history dependent. These results indicate that the ZFC procedure results in an unusual penetration of the vortices in the small superconducting disks.

  2. Photosensitivity of pulsed laser deposited Ge20As20Se60 and Ge10As30Se60 amorphous thin films

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Amorphous Ge20As20Se60/Ge10As30Se60 films are fabricated by pulsed laser deposition. • Photosensitivity of the layers is studied by employing spectroscopic ellipsometry. • As-deposited/relaxed thin films were irradiated by 593, 635, and 660 nm lasers. • Ge20As20Se60 layers present almost zero photorefraction in relaxed state. - Abstract: Amorphous Ge20As20Se60 and Ge10As30Se60 thin films are fabricated by pulsed laser deposition. Prepared films are characterized in terms of their morphology, chemical composition, and optical properties. Special attention is given to the photosensitivity of the layers, which was studied by spectroscopic ellipsometry with as-deposited, annealed and exposed films by three different laser sources (593, 635, and 660 nm). The results show better photostability for Ge20As20Se60 thin films, where photoinduced change of optical band gap was found to be equal or less than 0.04 eV and these layers present almost zero photorefraction

  3. A device model for thin silicon-on-insulator SiGe heterojunction bipolar transistors with saturation effects

    Institute of Scientific and Technical Information of China (English)

    Xu Xiao-Bo; Xu Kai-Xuan; Zhang He-Ming; Qin Shan-Shan

    2011-01-01

    In this paper,we describe the saturation effect of a silicon germanium (SiGe) heterojunction bipolar transistor (HBT) fabricated on a thin silicon-on-insulator (SOI) with a step-by-step derivation of the model formulation. The collector injection width,the internal base-collector bias,and the hole density at the base-collector junction interface are analysed by considering the unique features of the internal and the external parts of the collector,.they are different from those of a bulk counterpart.

  4. Pressure induced amorphization and collapse of magnetic order in type-I clathrate Eu8Ga16Ge30

    OpenAIRE

    Mardegan, J. R. L.; Fabbris, G.; Veiga, L. S. I.; Adriano, C.; M.A. Avila; Haskel, D.; Giles, C.

    2013-01-01

    We investigate the low temperature structural and electronic properties of the type-I clathrate Eu8Ga16Ge30 under pressure using x-ray powder diffraction (XRD), x-ray absorption near-edge structure (XANES) and x-ray magnetic circular dichroism (XMCD) techniques. The XRD measurements reveal a transition to an amorphous phase above 18 GPa. Unlike previous reports on other clathrate compounds, no volume-collapse is observed prior to the crystalline-amorphous phase transition which takes place wh...

  5. Weak avalanche multiplication in SiGe heterojunction bipolar transistors on thin film silicon-on-insulator

    Institute of Scientific and Technical Information of China (English)

    Xu Xiao-Bo; Zhang He-Ming; Hu Hui-Yong; Li Yu-Chen; Qu Jiang-Tao

    2011-01-01

    In this paper,we propose an analytical avalanche multiplication model for the next generation of SiGe siliconon-insulator (SOI) heterojunction bipolar transistors (HBTs) and consider their vertical and lateral impact ionizations for the first time.Supported by experimental data,the analytical model predicts that the avalanche multiplication governed by impact ionization shows kinks and the impact ionization effect is small compared with that of the bulk HBT,resulting in a larger base-collector breakdown voltage.The model presented in the paper is significant and has useful applications in the design and simulation of the next generation of SiGe SOI BiCMOS technology.

  6. An Analytical Avalanche Multiplication Model for Partially Depleted Silicon-on-Insulator SiGe Heterojunction Bipolar Transistors

    Institute of Scientific and Technical Information of China (English)

    XU Xiao-Bo; ZHANG He-Ming

    2011-01-01

    An analytical expression for avalanche multiplication of a novel vertical SiGe partially depleted heterojunction bipolar transistor (HBT) on a thin silicon-on-insulator (SOI) layer is obtained,considering vertical and horizontal impact ionization effects.The avalanche multiplication is found to be dependent on the collector width and doping concentration,and shows kinks with the increase of reverse base-collector bias,which is quite different from that of a conventional bulk HBT.The model is consistent with the experimental and simulation data and is found to be significant for the design and simulation of 0.13μm millimeter wave SiGe SOI BiCMOS technology.

  7. First- and second-order electrical modelling and experiment on very high speed SiGeC heterojunction bipolar transistors

    Science.gov (United States)

    Nunez-Perez, José Cruz; Lakhdara, Maya; Bouhouche, Manel; Verdier, Jacques; Latreche, Saïda; Gontrand, Christian

    2009-04-01

    We present in this paper an electrical study centred on NPN heterojunction bipolar transistors (HBTs), realized in an industrial BiCMOS SiGe:C process, featuring high attractive performances (ft > 200 GHz) in terms of microwave behaviour and low-frequency noise; reaching this level of performance with good dc characteristics could be however a difficult challenge. Electrical modelling is investigated, using our 2D simulator, based on the drift-diffusion model (DDM). The simulations were very efficient for optimizing the devices. The dc and ac results obtained in this work are efficiently compared with electrical characteristics coming from measurements and SPICE-like parameter extractions, from simulations via a compact model (HICUM) implemented in the so-called commercial simulator ADS (advanced design system). This work was a first step for designing RF circuits like oscillators in a simple way.

  8. Effect of Si interface surface roughness to the tunneling current of the Si/Si{sub 1-x}Ge{sub x}/Si heterojunction bipolar transistor

    Energy Technology Data Exchange (ETDEWEB)

    Hasanah, Lilik, E-mail: lilikhasanah@upi.edu; Suhendi, Endi; Tayubi, Yuyu Rahmat; Yuwono, Heru [Department of Physics Education, Universitas Pendidikan Indonesia, Jl. Setiabudhi 229 Bandung 40154 (Indonesia); Nandiyanto, Asep Bayu Dani [Department Kimia, Universitas Pendidikan Indonesia, Jl. Setiabudhi 229 Bandung 40154 (Indonesia); Murakami, Hideki [Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan); Khairrurijal [Physics of Electronic Materials Research Division, Institut Teknologi Bandung, Bandung 40132 (Indonesia)

    2016-02-08

    In this work we discuss the surface roughness of Si interface impact to the tunneling current of the Si/Si{sub 1-x}Ge{sub x}/Si heterojunction bipolar transistor. The Si interface surface roughness can be analyzed from electrical characteristics through the transversal electron velocity obtained as fitting parameter factor. The results showed that surface roughness increase as Ge content of virtual substrate increase This model can be used to investigate the effect of Ge content of the virtual substrate to the interface surface condition through current-voltage characteristic.

  9. The thickness dependence of the crystallization behavior in sandwiched amorphous Ge2Sb2Te5 thin films

    Science.gov (United States)

    Bai, G.; Li, R.; Xu, H. N.; Xia, Y. D.; Liu, Z. G.; Lu, H. M.; Yin, J.

    2011-12-01

    The thickness dependent crystallization behavior of thin amorphous Ge2Sb2Te5(GST) films sandwiched between different cladding materials has been investigated based on a thermodynamic model. It is revealed that there is a critical thickness below which the crystallization cannot occur. The critical thickness is determined by the energy difference Δγ between the crystalline GST/substrate interface energy and the amorphous GST/substrate interface energy, the melting enthalpy, and the mole volume. The calculated result is in good agreement with the experiments. Furthermore, the crystallization temperature is also affected by interface energy difference Δγ. Larger Δγ gives rise to a higher crystallization temperature, and vice versa. This impact becomes stronger as the film thickness is decreased.

  10. Comparison of total dose effects on SiGe heterojunction bipolar transistors induced by different swift heavy ion irradiation

    Science.gov (United States)

    Sun, Ya-Bin; Fu, Jun; Xu, Jun; Wang, Yu-Dong; Zhou, Wei; Zhang, Wei; Cui, Jie; Li, Gao-Qing; Liu, Zhi-Hong

    2014-11-01

    The degradations in NPN silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) were fully studied in this work, by means of 25-MeV Si, 10-MeV Cl, 20-MeV Br, and 10-MeV Br ion irradiation, respectively. Electrical parameters such as the base current (IB), current gain (β), neutral base recombination (NBR), and Early voltage (VA) were investigated and used to evaluate the tolerance to heavy ion irradiation. Experimental results demonstrate that device degradations are indeed radiation-source-dependent, and the larger the ion nuclear energy loss is, the more the displacement damages are, and thereby the more serious the performance degradation is. The maximum degradation was observed in the transistors irradiated by 10-MeV Br. For 20-MeV and 10-MeV Br ion irradiation, an unexpected degradation in IC was observed and Early voltage decreased with increasing ion fluence, and NBR appeared to slow down at high ion fluence. The degradations in SiGe HBTs were mainly attributed to the displacement damages created by heavy ion irradiation in the transistors. The underlying physical mechanisms are analyzed and investigated in detail.

  11. Reversible Resistance Switching Effect in Amorphous Ge1Sb4Te7 Thin Films without Phase Transformation

    Institute of Scientific and Technical Information of China (English)

    SUN Hua-Jun; HOU Li-Song; WU Yi-Qun; TANG Xiao-Dong

    2009-01-01

    We demonstrate a reversible resistance switching effect that does not rely on amorphous-crystalline phase trans-formation in a nanoscale capacitor-like cell using Ge1Sb4Te7 films as the working material. The polarity and amplitude of the applied electric voltage switches the cell resistance between low- and high-resistance states, as revealed in the current-voltage characteristics of the film by conductive atomic force microscopy (CAFM). This reversible SET/RESET switching effect is induced by voltage pulses and their polarity. The change of electrical resistance due to the switching effect is approximately two orders of magnitude.

  12. Kinetics of liquid-mediated crystallization of amorphous Ge from multi-frame dynamic transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Santala, M. K., E-mail: melissa.santala@oregonstate.edu; Campbell, G. H. [Materials Science Division, Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551 (United States); Raoux, S. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany)

    2015-12-21

    The kinetics of laser-induced, liquid-mediated crystallization of amorphous Ge thin films were studied using multi-frame dynamic transmission electron microscopy (DTEM), a nanosecond-scale photo-emission transmission electron microscopy technique. In these experiments, high temperature gradients are established in thin amorphous Ge films with a 12-ns laser pulse with a Gaussian spatial profile. The hottest region at the center of the laser spot crystallizes in ∼100 ns and becomes nano-crystalline. Over the next several hundred nanoseconds crystallization continues radially outward from the nano-crystalline region forming elongated grains, some many microns long. The growth rate during the formation of these radial grains is measured with time-resolved imaging experiments. Crystal growth rates exceed 10 m/s, which are consistent with crystallization mediated by a very thin, undercooled transient liquid layer, rather than a purely solid-state transformation mechanism. The kinetics of this growth mode have been studied in detail under steady-state conditions, but here we provide a detailed study of liquid-mediated growth in high temperature gradients. Unexpectedly, the propagation rate of the crystallization front was observed to remain constant during this growth mode even when passing through large local temperature gradients, in stark contrast to other similar studies that suggested the growth rate changed dramatically. The high throughput of multi-frame DTEM provides gives a more complete picture of the role of temperature and temperature gradient on laser crystallization than previous DTEM experiments.

  13. Ultrafast optical response of the amorphous and crystalline states of the phase change material Ge2Sb2Te5

    Science.gov (United States)

    Miller, T. A.; Rudé, M.; Pruneri, V.; Wall, S.

    2016-07-01

    We examine the ultrafast optical response of the crystalline and amorphous phases of the phase change material Ge2Sb2Te5 (GST) below the phase transformation threshold. Simultaneous measurement of the transmissivity and reflectivity of thin film samples yields the time-dependent evolution of the dielectric function for both phases. We then identify how lattice motion and electronic excitation manifest in the dielectric response. The dielectric response of both phases is large but markedly different. At 800 nm, the changes in amorphous GST are well described by the Drude response of the generated photocarriers, whereas the crystalline phase is better described by the depopulation of resonant bonds. We find that the generated coherent phonons have a greater influence in the amorphous phase than the crystalline phase. Furthermore, coherent phonons do not influence resonant bonding. For fluences up to 50% of the transformation threshold, the structure does not exhibit bond softening in either phase, enabling large changes of the optical properties without structural modification.

  14. Amorphous silicon germanium carbide photo sensitive bipolar junction transistor with a base-contact and a continuous tunable high current gain

    Energy Technology Data Exchange (ETDEWEB)

    Bablich, A., E-mail: andreas.bablich@uni-siegen.de [Department of Electrical and Computer Engineering, Institute for Microsystem Technologies, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany); Merfort, C., E-mail: merfort@imt.e-technik.uni-siegen.de [Department of Electrical and Computer Engineering, Institute for Microsystem Technologies, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany); Eliasz, J., E-mail: jacek.eliasz@student.uni-siegen.de [Department of Electrical and Computer Engineering, Institute for Microsystem Technologies, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany); Schäfer-Eberwein, H., E-mail: heiko.schaefer@uni-siegen.de [Department of Electrical and Computer Engineering, Institute of High Frequency and Quantum Electronics, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany); Haring-Bolivar, P., E-mail: peter.haring@uni-siegen.de [Department of Electrical and Computer Engineering, Institute of High Frequency and Quantum Electronics, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany); Boehm, M., E-mail: markus.boehm@uni-siegen.de [Department of Electrical and Computer Engineering, Institute for Microsystem Technologies, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany)

    2014-05-02

    In this paper, the design, fabrication and characterization of an amorphous silicon germanium carbide (a-SiGeC:H) photo sensitive bipolar junction transistor (PS-BJT) with three terminals are presented. Whereas the current gain of similar transistor devices presented in the past (Wu et al., 1984; Hwang et al., 1993; Nascetti and Caputo, 2002; Chang et al., 1985a,b; Wu et al, 1985; Hong et al., 1990) can only be controlled with photo induced charge generation, the n–i–δp–i–n structure developed features a contacted base to provide the opportunity to adjust the current gain optically and electrically, too. Electron microscope-, current-/voltage- and spectral measurements were performed to study the PS-BJT behavior and calculate the electrical and optical current gain. The spectral response maximum of the base–collector diode has a value of 170 mA/W applying a base–collector voltage of − 1 V and is located at 620 nm. The base–emitter diode reaches a sensitivity of 25.7 mA/W at 530 nm with a base-emitter voltage of − 3 V. The good a-Si:H transport properties are validated in a μτ-product of 4.6 × 10{sup −6} cm{sup 2} V s, which is sufficient to reach a continuous base- and photo-tunable current gain of up to − 126 at a base current of I{sub B} = + 10 nA and a collector–emitter voltage of V{sub CE} = − 3 V. The transistor obtains a maximum collector current of − 65.5 μA (V{sub CE} = − 3 V) and + 56.2 μA (V{sub CE} = + 3 V) at 10,000 lx 5300 K white-light illumination. At 3300 lx, the electrical current gain reaches a value of + 100 (V{sub CE} = + 2 V) at I{sub B} = 10 nA. With a negative base current of I{sub B} = − 10 nA the electrical gain can be adjusted between 87 (V{sub CE} = + 2 V) and − 106 (V{sub CE} = -3 V), respectively. When no base charge is applied, the transistor is “off” for V{sub CE} > − 3 V. Reducing the base current increases the electrical current gain. Operating with a voltage V{sub CE} of just ± 2 V

  15. Amorphous silicon germanium carbide photo sensitive bipolar junction transistor with a base-contact and a continuous tunable high current gain

    International Nuclear Information System (INIS)

    In this paper, the design, fabrication and characterization of an amorphous silicon germanium carbide (a-SiGeC:H) photo sensitive bipolar junction transistor (PS-BJT) with three terminals are presented. Whereas the current gain of similar transistor devices presented in the past (Wu et al., 1984; Hwang et al., 1993; Nascetti and Caputo, 2002; Chang et al., 1985a,b; Wu et al, 1985; Hong et al., 1990) can only be controlled with photo induced charge generation, the n–i–δp–i–n structure developed features a contacted base to provide the opportunity to adjust the current gain optically and electrically, too. Electron microscope-, current-/voltage- and spectral measurements were performed to study the PS-BJT behavior and calculate the electrical and optical current gain. The spectral response maximum of the base–collector diode has a value of 170 mA/W applying a base–collector voltage of − 1 V and is located at 620 nm. The base–emitter diode reaches a sensitivity of 25.7 mA/W at 530 nm with a base-emitter voltage of − 3 V. The good a-Si:H transport properties are validated in a μτ-product of 4.6 × 10−6 cm2 V s, which is sufficient to reach a continuous base- and photo-tunable current gain of up to − 126 at a base current of IB = + 10 nA and a collector–emitter voltage of VCE = − 3 V. The transistor obtains a maximum collector current of − 65.5 μA (VCE = − 3 V) and + 56.2 μA (VCE = + 3 V) at 10,000 lx 5300 K white-light illumination. At 3300 lx, the electrical current gain reaches a value of + 100 (VCE = + 2 V) at IB = 10 nA. With a negative base current of IB = − 10 nA the electrical gain can be adjusted between 87 (VCE = + 2 V) and − 106 (VCE = -3 V), respectively. When no base charge is applied, the transistor is “off” for VCE > − 3 V. Reducing the base current increases the electrical current gain. Operating with a voltage VCE of just ± 2 V, the device presented in this paper obtains no optical gain with an incident

  16. Mode locking features of driven vortex matter in an amorphous MoGe film detected by rf impedance technique

    International Nuclear Information System (INIS)

    We have investigated mode locking resonance of a driven vortex lattice in an amorphous MoGe film by means of rf impedance measurements. This technique allows us to detect directly the lattice motion in response to a rf current superimposed on top of a dc current. At low rf currents the resonance appears as jumps (dips) in real (imaginary) part of rf impedance Z. On increasing rf current, the jump height in the real part of Z at a given resonant condition decreases monotonically, whereas the imaginary part of Z exhibits a transformation from the dip to peak behaviors. Namely, the resonant feature changes from capacitive to inductive responses, on increasing rf current. This behavior implies variations in the phase of rf current relative to that of the lattice velocity modulated by the pinning potential.

  17. Analytical base-collector depletion capacitance in vertical SiGe heterojunction bipolar transistors fabricated on CMOS-compatible silicon on insulator

    Institute of Scientific and Technical Information of China (English)

    Xu Xiao-Bo; Zhang He-Ming; Hu Hui-Yong; Ma Jian-Li; Xu Li-Jun

    2011-01-01

    The base-collector depletion capacitance for vertical SiGe npn heterojunction bipolar transistors (HBTs) on silicon on insulator (SOI) is split into vertical and lateral parts. This paper proposes a novel analytical depletion capacitance model of this structure for the first time. A large discrepancy is predicted when the present model is compared with the conventional depletion model, and it is shown that the capacitance decreases with the increase of the reverse collectorbase bias-and shows a kink as the reverse collector-base bias reaches the effective vertical punch-through voltage while the voltage differs with the collector doping concentrations, which is consistent with measurement results. The model can be employed for a fast evaluation of the depletion capacitance of an SOI SiGe HBT and has useful applications on the design and simulation of high performance SiGe circuits and devices.

  18. Analytical base-collector depletion capacitance in vertical SiGe heterojunction bipolar transistors fabricated on CMOS-compatible silicon on insulator

    Science.gov (United States)

    Xu, Xiao-Bo; Zhang, He-Ming; Hu, Hui-Yong; Ma, Jian-Li; Xu, Li-Jun

    2011-01-01

    The base—collector depletion capacitance for vertical SiGe npn heterojunction bipolar transistors (HBTs) on silicon on insulator (SOI) is split into vertical and lateral parts. This paper proposes a novel analytical depletion capacitance model of this structure for the first time. A large discrepancy is predicted when the present model is compared with the conventional depletion model, and it is shown that the capacitance decreases with the increase of the reverse collector—base bias—and shows a kink as the reverse collector—base bias reaches the effective vertical punch-through voltage while the voltage differs with the collector doping concentrations, which is consistent with measurement results. The model can be employed for a fast evaluation of the depletion capacitance of an SOI SiGe HBT and has useful applications on the design and simulation of high performance SiGe circuits and devices.

  19. Control of carbon content in amorphous GeTe films deposited by plasma enhanced chemical vapor deposition (PE-MOCVD) for phase-change random access memory applications

    International Nuclear Information System (INIS)

    Amorphous and smooth GeTe thin films are deposited on 200 mm silicon substrates by plasma enhanced—metal organic chemical vapor deposition (PE–MOCVD) using the commercial organometallic precursors TDMAGe and DIPTe as Ge and Te precursors, respectively. X-ray photoelectron spectroscopy (XPS) measurements show a stoichiometric composition of the deposited GeTe films but with high carbon contamination. Using information collected by Optical Emission Spectroscopy (OES) and XPS, the origin of carbon contamination is determined and the dissociation mechanisms of Ge and Te precursors in H2 + Ar plasma are proposed. As a result, carbon level is properly controlled by varying operating parameters such as plasma radio frequency power, pressure and H2 rate. Finally, GeTe films with carbon level as low as 5 at. % are obtained. (paper)

  20. Photosensitivity of pulsed laser deposited Ge{sub 20}As{sub 20}Se{sub 60} and Ge{sub 10}As{sub 30}Se{sub 60} amorphous thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hawlová, P.; Olivier, M.; Verger, F. [Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice (Czech Republic); Nazabal, V. [Chemical Sciences Institute of Rennes (ISCR), Glasses and Ceramics Team, UMR-CNRS 6226, University of Rennes 1, 35042 Rennes Cedex (France); Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice (Czech Republic); Němec, P., E-mail: petr.nemec@upce.cz [Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice (Czech Republic)

    2013-10-15

    Graphical abstract: - Highlights: • Amorphous Ge{sub 20}As{sub 20}Se{sub 60}/Ge{sub 10}As{sub 30}Se{sub 60} films are fabricated by pulsed laser deposition. • Photosensitivity of the layers is studied by employing spectroscopic ellipsometry. • As-deposited/relaxed thin films were irradiated by 593, 635, and 660 nm lasers. • Ge{sub 20}As{sub 20}Se{sub 60} layers present almost zero photorefraction in relaxed state. - Abstract: Amorphous Ge{sub 20}As{sub 20}Se{sub 60} and Ge{sub 10}As{sub 30}Se{sub 60} thin films are fabricated by pulsed laser deposition. Prepared films are characterized in terms of their morphology, chemical composition, and optical properties. Special attention is given to the photosensitivity of the layers, which was studied by spectroscopic ellipsometry with as-deposited, annealed and exposed films by three different laser sources (593, 635, and 660 nm). The results show better photostability for Ge{sub 20}As{sub 20}Se{sub 60} thin films, where photoinduced change of optical band gap was found to be equal or less than 0.04 eV and these layers present almost zero photorefraction.

  1. X-ray photoelectron spectroscopy studies of Ag-doped thin amorphous Ge{sub x}Sb{sub 40-x}S{sub 60} films

    Energy Technology Data Exchange (ETDEWEB)

    Debnath, R.K.; Fitzgerald, A.G.; Christova, K

    2002-12-30

    X-ray photoelectron spectroscopy has been used to determine the binding energies of the core electrons in Ag-doped amorphous thin Ge{sub x}Sb{sub 40-x}S{sub 60} films (x=15, 20, 25 and 27). Chemical shifts of the constituent elements have revealed that electrons are transferred from chalcogenide to metal and compounds such as Ag{sub 2}S and Ag{sub 2}O are likely to foue to photo-induced chemical modification and oxidation, respectively. Charge defects are induced in the amorphous system.

  2. Effect of Sb addition on linear and non-linear optical properties of amorphous Ge-Se-Sn thin films

    Science.gov (United States)

    Sharma, Navjeet; Sharma, Surbhi; Sarin, Amit; Kumar, Rajesh

    2016-01-01

    Optical characterization of amorphous thin films of Ge20Sn10Se70-xSbx (x = 0, 3, 6, 9, 12, 15) has been carried out. Thin films were deposited onto pre cleaned glass substrates using thermal evaporation technique. Transmission spectra of the films were recorded, for normal incidence, in range 400-2400 nm. Refractive index of the films was calculated using the envelope method by Swanepoel. Dispersion analysis has been carried out using single effective oscillator model. Other optical constants such as absorption coefficients, extinction coefficients have also been evaluated. Tauc plots were used to evaluate the optical band gap. The refractive index has been found to be increasing while the band gap decreases with increasing Sb concentration. The observed optical behavior of the films has been explained using chemical bond approach. Cohesive energy is found to be decreasing in the present work, which reflects that bond strength decreases with the increasing content of Sb. Non-linear optical parameters (i.e. n2 and χ(3)) have been derived from linear optical parameters (i.e. n, k, Eg). Observed changes in linear and non-linear parameters have been reported in this study.

  3. Amorphous to fcc-polycrystal transition in Ge2Sb2Te5 thin films studied by electrical measurements: Data analysis and comparison with direct microscopy observations

    International Nuclear Information System (INIS)

    We experimentally investigate the isothermal amorphous-to-fcc polycrystalline phase transition process in amorphous Ge2Sb2Te5 thin films prepared by sputtering. The amorphous layers were either as deposited or formed by Ar+ ion implantation after crystallization at 300 deg. C. The kinetics of the amorphous-to-polycrystal transition are analyzed through electrical measurements, in which the Johnson-Mehl-Avrami-Kolmogorov theory is employed. The procedure to extract the kinetics of the phase transition from conductivity versus time data is carefully discussed and compared to data of cross-sectional transmission electron microscopy images versus anneal time. By following this proposed procedure, the nucleation and growth parameters, and the activation energies have been determined. Results indicate that the process of isothermal crystallization in Ge2Sb2Te5 takes place in two stages, in which the Avrami exponent changes in the range from 3 to 1. These results are understood in terms of modifications in the kinetics of the phase transition.

  4. Work function contrast and energy band modulation between amorphous and crystalline Ge{sub 2}Sb{sub 2}Te{sub 5} films

    Energy Technology Data Exchange (ETDEWEB)

    Tong, H.; Yang, Z.; Yu, N. N.; Zhou, L. J.; Miao, X. S., E-mail: miaoxs@mail.hust.edu.cn [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-08-24

    The work function (WF) is of crucial importance to dominate the carrier transport properties of the Ge-Sb-Te based interfaces. In this letter, the electrostatic force microscopy is proposed to extract the WF of Ge{sub 2}Sb{sub 2}Te{sub 5} (GST) films with high spatial and energy resolution. The measured WF of as-deposited amorphous GST is 5.34 eV and decreases drastically after the amorphous GST is crystallized by annealing or laser illumination. A 512 × 512 array 2D-WF map is designed to study the WF spatial distribution and shows a good consistency. The WF contrast between a-GST and c-GST is ascribed to band modulation, especially the modification of electron affinity including the contribution of charges or dipoles. Then, the band alignments of GST/n-Si heterostructures are obtained based on the Anderson's rule. Due to the band modulation, the I-V characteristics of a-GST/Si heterojunction and c-GST/Si heterojunction are very different from each other. The quantitative relationship is calculated by solving the Poisson's equation, which agrees well with the I-V measurements. Our findings not only suggest a way to further understand the electrical transport properties of Ge-Sb-Te based interfaces but also provide a non-touch method to distinguish crystalline area from amorphous matrix with high spatial resolution.

  5. Absence of mode-locking resonance for driven vortices in a thin amorphous MoxGe1−x film

    International Nuclear Information System (INIS)

    We present measurements of the mode-locking (ML) resonance for the thin amorphous MoxGe1−x film with weak pinning. In contrast to the thick film, where the clear ML resonance indicative of driven vortex lattices is observed over a wide temperature T and field B range, any sign of ML is not detected for the thin film down to below 1 K The results suggest that the vortex lattice for the thin film may be unstable against small pinning. We construct the vortex phase diagram in the B − T plane, which consists of disordered solid phase and large liquid phase.

  6. Coherent phonon modes of crystalline and amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} thin films: A fingerprint of structure and bonding

    Energy Technology Data Exchange (ETDEWEB)

    Shalini, A.; Liu, Y.; Srivastava, G. P.; Hicken, R. J. [Department of Physics and Astronomy, University of Exeter, Exeter EX4 4QL (United Kingdom); Katmis, F.; Braun, W. [Paul Drude Institute for Solid State Electronics, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2015-01-14

    Femtosecond optical pump-probe measurements have been made upon epitaxial, polycrystalline, and amorphous thin films of Ge{sub 2}Sb{sub 2}Te{sub 5} (GST). A dominant coherent optical phonon mode of 3.4 THz frequency is observed in time-resolved anisotropic reflectance (AR) measurements of epitaxial films, and is inferred to have 3-dimensional T{sub 2}-like character based upon the dependence of its amplitude and phase on pump and probe polarization. In contrast, the polycrystalline and amorphous phases exhibit a comparatively weak mode of about 4.5 THz frequency in both reflectivity (R) and AR measurements. Raman microscope measurements confirm the presence of the modes observed in pump-probe measurements, and reveal additional modes. While the Raman spectra are qualitatively similar for all three phases of GST, the mode frequencies are found to be different within experimental error, ranging from 3.2 to 3.6 THz and 4.3 to 4.7 THz, indicating that the detailed crystallographic structure has a significant effect upon the phonon frequency. While the lower frequency (3.6 THz) mode of amorphous GST is most likely associated with GeTe{sub 4} tetrahedra, modes in epitaxial (3.4 THz) and polycrystalline (3.2 THz) GST could be associated with either GeTe{sub 6} octahedra or Sb-Te bonds within defective octahedra. The more polarizable Sb-Te bonds are the most likely origin of the higher frequency (4.3–4.7 THz) mode, although the influence of Te-Te bonds cannot be excluded. The effect of high pump fluence, which leads to irreversible structural changes, has been explored. New modes with frequency of 3.5/3.6 THz in polycrystalline/amorphous GST may be associated with Sb{sub 2}Te{sub 3} or GeTe{sub 4} tetrahedra, while a 4.2 THz mode observed in epitaxial GST may be related to segregation of Sb.

  7. Preparing amorphous graphite/resin bipolar plate by mould pressing process%模压成型工艺制备微晶石墨/树脂双极板

    Institute of Scientific and Technical Information of China (English)

    林政宇; 张杰; 刘兵

    2011-01-01

    Amorphous graphite/resin composite bipolar plates for PEMFC were prepared by mould pressing process. Thermoset-ting resin was used as the binder and amorphous graphite as the conductive filler. The effects of filler particle size,filler content, thermosetting resin and moulding condition on the performance of bipolar plates were studied. The bipolar plate prepared with ther-mosetting resin P104-02 whose content was 18% ~ 20% as binder,amorphous graphite whose particle size was 200 ~ 250 mesh as conductive filler,in the moulding condition of 140- 145℃ , 15 - 20 Mpa and 18 ~ 22 min had such performance:flexural strength > 25 Mpa,conductivity > 100 S/cm,permeability < 3 × 10-5 ml/(s·cm2).%以微晶石墨为导电骨料,热固性树脂为粘结剂,通过模压成型工艺制备PEMFC用微晶石墨/树脂复合材料双极板.研究了骨科粒度分布、骨料配比、树脂种类和成型条件等对双极板性能的影响.以含量为18%~20%的双酚A乙烯基树脂(P104-02)为粘结剂,粒度为200~250目的石墨粉为导电骨料,在140 ~ 145℃、15 ~ 20 MPa及18~22 min的成型条件下制备的双极板的性能为:弯曲强度> 25 MPa、电导率>100 S/cm、气体渗透率<3×10-5 ml/(s·cm2).

  8. High Power SiGe X-Band (8~10GHz) Heterojunction Bipolar Transistors and Amplifiers

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Limited by increased parasitics and thermal effects as device size increases, current commercial SiGe power HBTs are difficult to operate at X-band (8~ 12GHz) frequencies with adequate power added efficiencies at high power levels. We find that, by changing the heterostructure and doping profile of SiGe HBTs, their power gain can be significantly improved without resorting to substantial lateral scaling. Furthermore, employing a common-base configuration with a proper doping profile instead of a common-emitter configuration improves the power gain characteristics of SiGe HBTs, thus permitting these devices to be efficiently operated at X-band frequencies. In this paper,we report the results of SiGe power HBTs and MMIC power amplifiers operating at 8~10GHz. At 10GHz,a 22.5dBm (178mW) RF output power with a concurrent gain of 7.32dB is measured at the peak power-added efficiency of 20.0%, and a maximum RF output power of 24.0dBm (250mW) is achieved from a 20 emitter finger SiGe power HBT. The demonstration of a single-stage X-band medium-power linear MMIC power amplifier is also realized at 8GHz. Employing a 10-emitter finger SiGe HBT and on-chip input and output matching passive components, a linear gain of 9.7dB,a maximum output power of 23.4dBm,and peak power added efficiency of 16% are achieved from the power amplifier. The MMIC exhibits very low distortion with 3rd order intermodulation (IM) suppression C/I of -13dBc at an output power of 21.2dBm and over 20dBm 3rd order output intercept point (OIP3).

  9. The phase-change kinetics of amorphous Ge2Sb2Te5 and device characteristics investigated by thin-film mechanics

    International Nuclear Information System (INIS)

    For high switching speed and high reliability of phase-change random access memory (PcRAM), we need to identify materials that enable fast crystallization at elevated temperatures but are stable at and above room temperature. Achieving this goal requires a breakthrough in our understanding of the unique crystallization kinetics of amorphous phase change materials as a fragile glass, described as the non-Arrhenius behavior of atomic mobility. It is a highly rewarding task to unravel the unconventional crystallization kinetics and related properties, because these properties can be utilized to predict the device characteristics. This manuscript utilizes the thin-film mechanics to investigate the crystallization kinetics of amorphous Ge2Sb2Te5 phase-change materials doped with Al, Bi, C and N, which is an effective method to analyze the structural changes in amorphous materials. Crystallization temperature, super-cooled liquid region, glass transition temperature and fragility are measured to describe the crystallization kinetics tuned by doping; characteristic fragile-to-strong transition is observed for C and N dopings due to their structural feature as an interstitial dopant. Consequently, doping effects on the phase stability and atomic mobility manifested by the crystallization temperature and the super-cooled liquid region (or 1/fragility) successfully correspond with PcRAM characteristics, i.e., reliability and switching speed, respectively

  10. Optical waveguide based on amorphous Er{sup 3+}-doped Ga-Ge-Sb-S(Se) pulsed laser deposited thin films

    Energy Technology Data Exchange (ETDEWEB)

    Nazabal, V., E-mail: virginie.nazabal@univ-rennes1.f [Sciences Chimiques de Rennes (SCR), UMR CNRS 6226, Equipe Verres et Ceramiques, Universite de Rennes 1, Rennes (France); Nemec, P. [Department of General and Inorganic Chemistry and Research Center, Faculty of Chemical Technology, University of Pardubice, Legions Sq. 565, 53210, Pardubice (Czech Republic); Jurdyc, A.M [Laboratoire de Physico-Chimie des Materiaux Luminescents (LPCML), UMR CNRS 5620, Universite Claude Bernard-Lyon 1, Villeurbanne (France); Zhang, S.; Charpentier, F. [Sciences Chimiques de Rennes (SCR), UMR CNRS 6226, Equipe Verres et Ceramiques, Universite de Rennes 1, Rennes (France); Lhermite, H. [IETR-Microelectronique, UMR CNRS 6251, Universite de Rennes 1, 35042 Rennes (France); Charrier, J. [FOTON, UMR 6082-ENSSAT, UMR CNRS 6251, Universite de Rennes 1, 35042 Rennes (France); Guin, J.P. [LARMAUR, UMR CNRS 6251, Universite de Rennes 1, 35042 Rennes (France); Moreac, A. [Institut de Physique de Rennes, UMR CNRS 6251, Universite de Rennes 1, 35042 Rennes (France); Frumar, M. [Department of General and Inorganic Chemistry and Research Center, Faculty of Chemical Technology, University of Pardubice, Legions Sq. 565, 53210, Pardubice (Czech Republic); Adam, J.-L. [Sciences Chimiques de Rennes (SCR), UMR CNRS 6226, Equipe Verres et Ceramiques, Universite de Rennes 1, Rennes (France)

    2010-06-30

    Amorphous chalcogenide films play a motivating role in the development of integrated planar optical circuits due to their potential functionality in near infrared (IR) and mid-IR spectral regions. More specifically, the photoluminescence of rare earth ions in amorphous chalcogenide films can be used in laser and amplifier devices in the IR spectral domain. The aim of the present investigation was to optimize the deposition conditions for the fabrication of undoped and Er{sup 3+} doped sulphide and selenide thin films with nominal composition Ga{sub 5}Ge{sub 20}Sb{sub 10}S(Se){sub 65} or Ga{sub 5}Ge{sub 23}Sb{sub 5}S{sub 67} by pulsed laser deposition (PLD). The study of compositional, morphological and structural characteristics of the layers was realized by scanning electron microscopy-energy dispersive spectroscopy, atomic force microscopy and Raman spectroscopy analyses, respectively. Some optical properties (transmittance, index of refraction, optical band gap, etc.) of prepared chalcogenide films and optical losses were investigated as well. The clear identification of near-IR photoluminescence of Er{sup 3+} ions was obtained for both selenide and sulphide films. The decay of the {sup 4}I{sub 13/2} {yields} {sup 4}I{sub 15/2} transition at 1.54 {mu}m in Er{sup 3+} doped Ga{sub 5}Ge{sub 20}Sb{sub 10}S{sub 65} PLD sulphide films was studied to assess the effects of film thickness, rare earth concentration and multilayer PLD deposition on their spectroscopic properties.

  11. Structural investigation of the amorphous/crystalline interface by means of quantitative high-resolution transmission electron microscopy on the systems a-Si/c-Si and a-Ge/c-Si; Strukturelle Untersuchung der amorph/kristallinen Grenzflaeche mittels quantitativer hochaufloesender Transmissionselektronenmikroskopie an den Systemen a-Si/c-Si und a-Ge/c-Si

    Energy Technology Data Exchange (ETDEWEB)

    Thiel, K.

    2006-11-02

    In this Thesis the interfaces between covalently bonded crystalline and amorphous materials were studied with regard to the induced ordering in the amorphous material in the interfacial region by means of high-resolution transmission electron microscopy (HREM). The interface between amorphous germanium and crystalline silicon and the interface between amorphous and crystalline silicon served as material system. In order to quantify the influence of the crystalline order on the amorphous material, the HREM images were periodically averaged along the interface. The intensity components, which are correlated with the period of the lattice image, could thus be separated from the statistical intensity fluctuations, which are characteristic for images of amorphous materials. Since amorphous materials can only be described meaningful by statistical distribution functions, for the induced order a three-dimensional distribution function {rho}{sub 3D}(r) was taken as a basis, which describes the probability to find an atom in the amorphous material, if r=0 is the position of an atom in the crystal. Its two-dimensional projection, {rho}, can be determined using iterative image matching techniques on averaged experimental and simulated interface images. For the analyzed material systems {rho} exhibits lateral ordering as well as a pronounced layering in the vicinity of the interface. In the case of the a-Si/c-Si sample the mean orientation of bonds was 70.5 , as is in the case of the undistorted diamond lattice, while for the a-Ge/c-Si sample 65 resulted. The standard deviation for the distribution of the deviations from the mean bond angle yields for the a-Ge/c-Si sample in the first atomic layer a value of 11.3 and for the a-Si/c-Si sample 1.9 . These results suggest the conclusion, that the differences in these values are to be interpreted as the reaction of the amorphous material to the volume misfit. Although for both material systems 1.4 nm was calculated for the width

  12. A cross sectional study on the crystallization of amorphous Ge2Sb2Te5 films induced by a single-pulse ultraviolet laser

    Science.gov (United States)

    Zhu, Z.; Liu, F. R.; Yang, J. F.; Fan, Z. K.; Liu, F.; Sun, N. X.

    2016-07-01

    In this paper, the crystallization along the film thickness of amorphous Ge2Sb2Te5 (a-GST) films induced by a single-pulse ultraviolet laser was investigated by using transmission electron microscopy (TEM) integrated with SAED. TEM observations showed that the crystalline GST (c-GST) was composed of columnar grains at the top surface and equaixed grains inside the film. Moreover, the columnar grains became larger with the increase of laser fluence. A three-dimensional finite element method simulation was further used to elucidate the temperature field by a nanosecond excimer laser in the cross section of the a-GST film. A big temperature gradient obtained at the top surface in the cooling process caused the formation of columnar grains, while columnar grains were gradually substituted by small equaixed grains with the decrease of temperature gradient downwards the film interior.

  13. Superconducting nanowire single photon detectors fabricated from an amorphous Mo{sub 0.75}Ge{sub 0.25} thin film

    Energy Technology Data Exchange (ETDEWEB)

    Verma, V. B.; Lita, A. E.; Vissers, M. R.; Marsili, F.; Pappas, D. P.; Mirin, R. P.; Nam, S. W. [National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305 (United States)

    2014-07-14

    We present the characteristics of superconducting nanowire single photon detectors (SNSPDs) fabricated from amorphous Mo{sub 0.75}Ge{sub 0.25} thin-films. Fabricated devices show a saturation of the internal detection efficiency at temperatures below 1 K, with system dark count rates below 500 cps. Operation in a closed-cycle cryocooler at 2.5 K is possible with system detection efficiencies exceeding 20% for SNSPDs which have not been optimized for high detection efficiency. Jitter is observed to vary between 69 ps at 250 mK and 187 ps at 2.5 K using room temperature amplifiers.

  14. Power SiGe Heterojunction Bipolar Transistors (HBTs) Fabricated by Fully Self-Aligned Double Mesa Technology

    Science.gov (United States)

    Lu, Liang-Hung; Mohammadi, Saeed; Ma, Zhen-Qiang; Ponchak, George E.; Alterovitz, Samuel A.; Strohm, Karl M.; Luy, Johann-Friedrich; Downey, Alan (Technical Monitor)

    2001-01-01

    Multifinger SiGe HBTs have been fabricated using a novel fully self-aligned double-mesa technology. With the novel process technology, a common-emitter 2x2x30 sq micrometer device exhibits high maximum oscillating frequency (f(sub max)) and cut-off frequency (f(sub T)) of 78 and 37 GHz, respectively. In class-A operation, a multifinger device with l0x2x30 sq micrometer emitter is expected to provide an output power of 25.6 dBm with a gain of 10 dB and a maximum power added efficiency (PAE) of 30.33% at 8 GHz.

  15. ac conductivity and dielectric properties of amorphous Se{sub 80}Te{sub 20-x}Ge{sub x} chalcogenide glass film compositions

    Energy Technology Data Exchange (ETDEWEB)

    Hegab, N.A. [Physics Department, Faculty of Education, Ain Shams University, Cairo (Egypt)], E-mail: abir_net_2005@hotmail.com; Afifi, M.A.; Atyia, H.E.; Farid, A.S. [Physics Department, Faculty of Education, Ain Shams University, Cairo (Egypt)

    2009-05-27

    Thin films of the prepared Se{sub 80}Te{sub 20-x}Ge{sub x} (x = 5, 7 and 10 at.%) were prepared by thermal evaporation technique. X-ray diffraction patterns showed that the films were in amorphous state. The ac conductivity and dielectric properties of the investigated film compositions were studied in the frequency range 0.1-100 kHz and in temperature range (303-373 K). The experimental results indicated that the ac conductivity and the dielectric properties depended on the temperature and frequency. The ac conductivity is found to obey the {omega}{sup s} law, in accordance with the hopping model, s is found to be temperature dependent (s < 1) and its value goes down as the temperature is increased. The temperature dependence of ac conductivity can be reasonably interpreted in terms of the correlated barrier hopping (CBH) model. Values of dielectric constant {epsilon}{sub 1} and dielectric loss {epsilon}{sub 2} were found to decrease with frequency and increase with temperature. The maximum barrier height W{sub m}, calculated from dielectric measurements according to Guintini equation, agrees with that proposed by the theory of hopping over potential barrier as suggested by Elliott in case of chalcogenide glasses. The density of localized states was estimated for the studied film compositions. The variation of the studied properties with Ge content was also investigated.

  16. Bipolar Disorder.

    Science.gov (United States)

    Miller, Thomas H

    2016-06-01

    Bipolar disorder is a chronic mental health disorder that is frequently encountered in primary care. Many patients with depression may actually have bipolar disorder. The management of bipolar disorder requires proper diagnosis and awareness or referral for appropriate pharmacologic therapy. Patients with bipolar disorder require primary care management for comorbidities such as cardiovascular and metabolic disorders. PMID:27262007

  17. Study of temperature and pressure dependences of electric properties of amorphous Ag-Ge-As-S chalcogenides containing carbon nanotubes

    International Nuclear Information System (INIS)

    Frequency and temperature dependences of impedance of AgGe1+xAs1-x(S+CNT)3, x = 0.4; 0.5; 0.6 were measured. There are maxima on frequency dependences of tangent of loss, which can be connected with relaxation processes inside the sample (the maximum at high frequencies) and the second maximum can be connected with processes occurring on the sample-electrode border. Activation energy of all synthesized materials was estimated to be near 0.5 eV. The relaxation of electric resistance at fixed pressures within the pressure range of 30 to 50 GPa was observed. It is established that the resistance decreases exponentially with time within this range of pressures

  18. Comparative study on crystallization characteristics of amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} films by an ultraviolet laser radiation and isothermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Z. [Institute of Laser Engineering, Beijing University of Technology, 100124, Beijing (China); Liu, F.R., E-mail: Liufr@bjut.edu.cn [Institute of Laser Engineering, Beijing University of Technology, 100124, Beijing (China); Wang, Z.M.; Fan, Z.K. [Institute of Laser Engineering, Beijing University of Technology, 100124, Beijing (China); Liu, F. [State Key Laboratory of Solidification Processing, Northwestern Poly technical University (China); Sun, N.X. [Electrical and Computer Engineering Department, Northeastern University, MA02115 (United States)

    2015-04-30

    Highlights: • Crystallization characteristics of α-GST by laser radiation and isothermal annealing were compared. • Effects of film thickness on the crystallization were also demonstrated. • A thinner α-GST film showed a more complete crystallization owing to thermal convection. • An obvious red shift in the Raman spectrum was observed for the laser induced crystallization. - Abstract: A comparative study on crystallization characteristics of amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} (GST) films induced by an ultraviolet pulse laser and isothermal annealing was carried out by using transmission electron microscopy (TEM) and Raman scattering. TEM observations showed that the mean grain size induced by a pulse laser was in the nanoscale. A more complete crystallization in the 50 nm thick GST film was obtained which was ascribed to the effect of thermal convection produced in a thinner GST film, however, when the film thickness was over 70 nm, no significant decrease in the mean grain size was found because of the effect of heating mode, where a surface heat source by the ultraviolet laser radiation caused a quick temperature drop. The body heating mode at the isothermal annealing condition made the mean grain size increase remarkably with the increase of film thickness, which could be up to the submicron scale, relative to the size of film thickness. The Raman spectrum analysis showed that a red shift was observed in laser induced Ge{sub 2}Sb{sub 2}Te{sub 5} films as compared to the isothermal annealing samples, which was caused by the resultant stress of the thermal stress and phase transformation stress.

  19. Comparative study on crystallization characteristics of amorphous Ge2Sb2Te5 films by an ultraviolet laser radiation and isothermal annealing

    International Nuclear Information System (INIS)

    Highlights: • Crystallization characteristics of α-GST by laser radiation and isothermal annealing were compared. • Effects of film thickness on the crystallization were also demonstrated. • A thinner α-GST film showed a more complete crystallization owing to thermal convection. • An obvious red shift in the Raman spectrum was observed for the laser induced crystallization. - Abstract: A comparative study on crystallization characteristics of amorphous Ge2Sb2Te5 (GST) films induced by an ultraviolet pulse laser and isothermal annealing was carried out by using transmission electron microscopy (TEM) and Raman scattering. TEM observations showed that the mean grain size induced by a pulse laser was in the nanoscale. A more complete crystallization in the 50 nm thick GST film was obtained which was ascribed to the effect of thermal convection produced in a thinner GST film, however, when the film thickness was over 70 nm, no significant decrease in the mean grain size was found because of the effect of heating mode, where a surface heat source by the ultraviolet laser radiation caused a quick temperature drop. The body heating mode at the isothermal annealing condition made the mean grain size increase remarkably with the increase of film thickness, which could be up to the submicron scale, relative to the size of film thickness. The Raman spectrum analysis showed that a red shift was observed in laser induced Ge2Sb2Te5 films as compared to the isothermal annealing samples, which was caused by the resultant stress of the thermal stress and phase transformation stress

  20. Compositional Dependence of the Optical Properties of Amorphous Semiconducting Glass Se80Ge20- x Cd x (0 ≤ x ≤ 12 at.%) Thin Films

    Science.gov (United States)

    Hegab, N. A.; Farid, A. S.; Shakra, A. M.; Afifi, M. A.; Alrebati, A. M.

    2016-07-01

    Se80Ge20- x Cd x (0 ≤ x ≤ 12 at.%) compositions were prepared by a quenching technique. Thin films of the obtained compositions were deposited on dry clean glass substrates by a thermal evaporation technique. The chemical composition of the film samples have been determined by energy dispersive x-ray spectroscopy (EDX). X-ray diffraction measurements showed the amorphous nature of the studied films. The optical constants ( n, k) were determined for the studied films using spectrophotometric measurements of transmittance T( λ) in the wavelength range (350 nm to 2500 nm), and using Swanepoel's method. The values of the dispersion energy E d, oscillator energy E o, the lattice dielectric constant ɛ ∞L and the high-frequency dielectric constant ɛ s were determined. The optical band gap Eg^{{opt}} is estimated for all compositions from the absorption coefficient α. The analysis of the optical absorption data revealed the existence of allowed indirect transitions for all compositions. The effect of adding Cd content on the obtained optical parameters was also discussed.

  1. Bipolar Disorder

    Science.gov (United States)

    Bipolar disorder is a serious mental illness. People who have it go through unusual mood changes. They go from ... down feeling is depression. The causes of bipolar disorder aren't always clear. It runs in families. ...

  2. Bipolar Disorder

    Science.gov (United States)

    ... types of psychotherapies. Other Treatment Options Electroconvulsive Therapy (ECT) : ECT can provide relief for people with severe bipolar ... been able to recover with other treatments. Sometimes ECT is used for bipolar symptoms when other medical ...

  3. Thermal stability and electrical properties of Se{sub 90}Ge{sub 10-x}In{sub x} amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Abo Ghazala, M.S. [Physics Department, Faculty of Science, Menoufia University, Sheben El-Koom (Egypt); Aboelhasn, E. [Physics Department, Faculty of Science, Banha University, Banha (Egypt); Amar, A.H. [Physics Department, Faculty of Education, Ain Shams University, Cairo (Egypt); Gamel, W. [Physics Department, Faculty of Science, Taiz University, Taiz (Yemen)

    2011-11-15

    Bulk glasses of Se{sub 90}Ge{sub 10-x}In{sub x}(where x = 2, 4 and 6 at.%) were prepared using a conventional rapid quenching technique. The amorphous nature and the crystalline phases of the samples annealed at 393 K for 25 h were investigated using X-ray diffraction. Calorimetric analysis of the bulk glassy samples has been carried out using differential scanning calorimetric (DSC) under non-isothermal condition. It was found that these glasses exhibit double glass transitions and double-stage crystallization transitions on heating. The glass transition temperature, T{sub g} and the crystallization transformation temperature, T{sub c} were found to be dependent on the composition and heating rates. The activation energy for glass transition (E{sub g}) and that for crystallization (E{sub c}) were evaluated using different empirical approaches and their composition dependence was discussed. The results revealed that the activation energy of crystallization, E{sub c} increases with rising the In content. The electrical resisitivity of the prepared glasses was measured as a function of temperature and annealing time. It was found that the activation energy of conduction deduced from the temperature dependence of the resistivity increases with increasing the In content. On the other hand it was found that the activation energy of crystallization deduced from the annealing time dependence of the resistivity using Avrami's equation is compositional dependent. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Bipolar disorder.

    Science.gov (United States)

    Grande, Iria; Berk, Michael; Birmaher, Boris; Vieta, Eduard

    2016-04-01

    Bipolar disorder is a recurrent chronic disorder characterised by fluctuations in mood state and energy. It affects more than 1% of the world's population irrespective of nationality, ethnic origin, or socioeconomic status. Bipolar disorder is one of the main causes of disability among young people, leading to cognitive and functional impairment and raised mortality, particularly death by suicide. A high prevalence of psychiatric and medical comorbidities is typical in affected individuals. Accurate diagnosis of bipolar disorder is difficult in clinical practice because onset is most commonly a depressive episode and looks similar to unipolar depression. Moreover, there are currently no valid biomarkers for the disorder. Therefore, the role of clinical assessment remains key. Detection of hypomanic periods and longitudinal assessment are crucial to differentiate bipolar disorder from other conditions. Current knowledge of the evolving pharmacological and psychological strategies in bipolar disorder is of utmost importance. PMID:26388529

  5. Bipolar Disorder

    Science.gov (United States)

    ... lows). These aren't the normal periods of happiness and sadness that everyone experiences from time to ... with long-lasting medical conditions (such as asthma , diabetes , or epilepsy ), teens with bipolar disorder need to ...

  6. Bipolar disorder

    OpenAIRE

    Goodwin, Frederick K; Ghaemi, S Nassir

    1999-01-01

    Bipolar disorder's unique combination of three characteristics - clear genetic diathesis, distinctive clinical features, early availability of an effective treatment (lithium) - explains its special place in the history of psychiatry and its contribution to the current explosive growth of neuroscience. This article looks at the state of the art in bipolar disorder from the vantage point of: (i) genetics (possible linkages on chromosomes 18 and 21q, polygenic hypothesis, research into genetic ...

  7. Effect of the Sn dopant on the crystallization of amorphous Ge2Sb2Te5 films induced by an excimer laser

    Science.gov (United States)

    Bai, N.; Liu, F. R.; Han, X. X.; Zhu, Z.; Liu, F.; Lin, X.; Sun, N. X.

    2015-11-01

    In this paper, the influence of Sn doping (0%, 8%, and 14%) on the crystallization of Ge2Sb2Te5 (GST) was studied with the aid of an ultraviolet laser. It was found that the addition of Sn element not only expanded the lattice parameter but also decreased the crystallization temperature and activation energy as compared to the GST. As compared to the Ge2Sb2Te5, a more complete crystallization of the Sn doping Ge2Sb2Te5 is mainly due to the lower binding energy of Sn-Te (359.8 kJ/mol), which could be more easily taken part in the bond breakage and formation than Ge-Te (456 kJ/mol) in such a short time as 30 ns. The equiaxial grains were obtained for the Sn8Ge15Sb23Te54 films when crystallization was induced by the laser fluence of 20 mJ/cm2 but the grains elongated when the laser fluence was increased to 60 mJ/cm2. The reason may be the incorporation of Sn elements changed the crystal nucleation mode.

  8. A study on the crystallization behavior of Sn-doped amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} by ultraviolet laser radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bai, N. [Institute of Laser Engineering, Beijing University of Technology, 100124, Beijing (China); Liu, F.R., E-mail: Liufr@bjut.edu.cn [Institute of Laser Engineering, Beijing University of Technology, 100124, Beijing (China); Han, X.X.; Zhu, Z. [Institute of Laser Engineering, Beijing University of Technology, 100124, Beijing (China); Liu, F.; Lin, X. [State Key Laboratory of Solidification Processing, Northwestern Poly technical University (China); Sun, N.X. [Electrical and Computer Engineering Department, Northeastern University, MA 02115 (United States)

    2014-10-15

    Highlights: • The Raman peaks of Sn doped GST moved towards lower wavenumbers compared to GST. • The crystallization fluence for Sn doped GST was smaller than that for pure GST. • The optical contrast increased from 15% to 40% with the addition of Sn. • Optical contrast changed little with the variation of laser fluence. - Abstract: In this paper, the influence of Sn doping (0%, 8% and 14%) on the crystallization of Ge{sub 2}Sb{sub 2}Te{sub 5} was studied with the aid of an ultraviolet laser. The XRD analyses revealed that the addition of Sn maintained the NaCl-type structure of Ge{sub 2}Sb{sub 2}Te{sub 5} after crystallization but expanded the lattice parameter due to the smaller atomic radii of Ge replaced by Sn. Raman peaks (123, 150 and 110 cm{sup −1}) moved towards lower wavenumbers (118, 137 and 104 cm{sup −1}), which can be explained by the remarkable decrease of the binding energy from Ge–Te to Sn–Te. A remarkable increase in optical contrast from 15% to 40% was observed in the Sn-doped Ge{sub 2}Sb{sub 2}Te{sub 5} film after crystallization with both the isothermal annealing and laser radiance. While the optical contrast changed little for a fixed volume fraction of Sn-doped sample with the variation of laser fluence which is attributed to the crystallization mechanism induced by laser under different fluences is the same.

  9. Transtorno bipolar

    OpenAIRE

    Alda Martin

    1999-01-01

    Os resultados de estudos de famílias sugerem que o transtorno bipolar tenha uma base genética. Essa hipótese foi reforçada em estudos de adoção e de gêmeos. A herança do transtorno bipolar é complexa, envolve vários genes, além de apresentar heterogeneidade e interação entre fatores genéticos e não-genéticos. Achados, que já foram replicados, já implicaram os cromossomos 4, 12, 18 e 21, entre outros, na busca por genes de suscetibilidade. Os resultados mais promissores foram obtidos através d...

  10. Transtorno bipolar

    Directory of Open Access Journals (Sweden)

    Alda Martin

    1999-01-01

    Full Text Available Os resultados de estudos de famílias sugerem que o transtorno bipolar tenha uma base genética. Essa hipótese foi reforçada em estudos de adoção e de gêmeos. A herança do transtorno bipolar é complexa, envolve vários genes, além de apresentar heterogeneidade e interação entre fatores genéticos e não-genéticos. Achados, que já foram replicados, já implicaram os cromossomos 4, 12, 18 e 21, entre outros, na busca por genes de suscetibilidade. Os resultados mais promissores foram obtidos através de estudos de ligação. Por outro lado, os estudos de associação geraram dados interessantes, mas ainda vagos. Os estudos de populações de pacientes homogêneos e a melhor definição do fenótipo deverão contribuir para avanços futuros. A identificação dos genes relacionados ao transtorno bipolar irá permitir o melhor entendimento e tratamento dessa doença.

  11. Metastable Ge nanocrystalline in SiGe matrix for photodiode

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang, Yao-Tsung; Su, Chien-Hao [Department of Chemical and Materials Engineering, National Central University, Taoyuan City 320, Taiwan (China); Chang, Jenq-Yang [Department of Optics and Photonics, National Central University, Taoyuan City 320, Taiwan (China); Cheng, Shao-Liang; Lin, Po-Chen [Department of Chemical and Materials Engineering, National Central University, Taoyuan City 320, Taiwan (China); Wu, Albert T., E-mail: atwu@ncu.edu.tw [Department of Chemical and Materials Engineering, National Central University, Taoyuan City 320, Taiwan (China)

    2015-09-15

    Highlights: • Amorphous Si{sub 1−x}Ge{sub x} films were prepared by co-sputtering by using rapid thermal annealing to form nanocrystal films. • Si–Ge alloy does not form total solid solution that is shown in phase diagram. • HRTEM images indicated that Ge atoms segregated and formed Ge clusters that are embedded in the amorphous Si–Ge matrix. • Ge segregation permitted high mobility; the grain size increased and the resistivity decreased with higher Ge content. • The rectifying property became stronger with the Ge fraction in the Si{sub 1−x}Ge{sub x} diodes. Si{sub 1−x}Ge{sub x} diodes are used as photodetectors, which provide a greater output current under illumination. - Abstract: Amorphous Si{sub 1−x}Ge{sub x} films were prepared by co-sputtering on an oxidized Si wafer, followed by rapid thermal annealing to form nanocrystal films. The formation of Ge nanocrystals was not at thermodynamic equilibrium formed in the amorphous Si{sub 1−x}Ge{sub x} matrix. High-resolution transmission electron microscopy was used to characterize the increase in the size of the grains in the Ge nanocrystals as the Ge content increased. The Ge nanocrystals have a greater absorption in the near-infrared region and higher carrier mobility than SiGe crystals, and the variation in their grain sizes can be used to tune the bandgap. This characteristic was exploited herein to fabricate n-Si{sub 1−x}Ge{sub x}/p-Si{sub 1−x}Ge{sub x} p–n diodes on insulating substrates, which were then examined by analyzing their current–voltage characteristics. The rectifying property became stronger as the fraction of Ge in the Si{sub 1−x}Ge{sub x} films increased. The Si{sub 1−x}Ge{sub x} diodes are utilized as photodetectors that have a large output current under illumination. This paper elucidates the correlations between the structural, optical and electrical properties and the p–n junction performance of the film.

  12. Neutrality in bipolar structures

    DEFF Research Database (Denmark)

    Montero, Javier; Rodríguez, J. Tinguaro; Franco, Camilo;

    2014-01-01

    In this paper, we want to stress that bipolar knowledge representation naturally allows a family of middle states which define as a consequence different kinds of bipolar structures. These bipolar structures are deeply related to the three types of bipolarity introduced by Dubois and Prade, but our...

  13. Cytokines in bipolar disorder

    DEFF Research Database (Denmark)

    Munkholm, Klaus; Vinberg, Maj; Vedel Kessing, Lars

    2012-01-01

    BACKGROUND: Current research and hypothesis regarding the pathophysiology of bipolar disorder suggests the involvement of immune system dysfunction that is possibly related to disease activity. Our objective was to systematically review evidence of cytokine alterations in bipolar disorder according...... to affective state. METHODS: We conducted a systemtic review of studies measuring endogenous cytokine concentrations in patients with bipolar disorder and a meta-analysis, reporting results according to the PRISMA statement. RESULTS: Thirteen studies were included, comprising 556 bipolar disorder patients...

  14. Staging Bipolar Disorder.

    OpenAIRE

    Vieta i Pascual, Eduard, 1963-; Reinares, M.; Rosa, A. R.

    2011-01-01

    The purpose of this study was to analyze the evidence supporting a staging model for bipolar disorder. The authors conducted an extensive Medline and Pubmed search of the published literature using a variety of search terms (staging, bipolar disorder, early intervention) to find relevant articles, which were reviewed in detail. Only recently specific proposals have been made to apply clinical staging to bipolar disorder. The staging model in bipolar disorder suggests a progression from prodro...

  15. 高速NPN锗硅异质结双极晶体管的设计与制作%Design and Fabrication of High Speed NPN SiGe Heterojunction Bipolar Transistor

    Institute of Scientific and Technical Information of China (English)

    钱文生; 刘冬华; 陈帆; 陈雄斌; 石晶; 段文婷; 胡君; 黄景丰

    2012-01-01

    The paper presents the device structure and fabrication process of 0.18 μm high speed SiGe HBT. The DC and RF characteristics of SiGe HBT are analyzed with typical Ft=U0 GHz, .BVcez = 1- 8 V and β=270. The impact of different process conditions on SiGe HBT performance is investigated, including the doping of implanted collector, EPI SiGeC base and polysili-con emitter as well as the thickness of SiGeC base. The optimum process conditions are exhibited.%报告了0.18 μm高速N型锗硅异质结双极晶体管(SiGe HBT)的器件结构和制作工艺.分析了SiGe HBT器件的直流和射频特性,其截止频率为110 GHz,击穿电压为1.8V,电流增益为270.研究了集电区掺杂及锗硅碳外延基区的厚度与掺杂工艺条件对器件特性的影响,并给出最优化的工艺条件.

  16. Oxide bipolar electronics: materials, devices and circuits

    Science.gov (United States)

    Grundmann, Marius; Klüpfel, Fabian; Karsthof, Robert; Schlupp, Peter; Schein, Friedrich-Leonhard; Splith, Daniel; Yang, Chang; Bitter, Sofie; von Wenckstern, Holger

    2016-06-01

    We present the history of, and the latest progress in, the field of bipolar oxide thin film devices. As such we consider primarily pn-junctions in which at least one of the materials is a metal oxide semiconductor. A wide range of n-type and p-type oxides has been explored for the formation of such bipolar diodes. Since most oxide semiconductors are unipolar, challenges and opportunities exist with regard to the formation of heterojunction diodes and band lineups. Recently, various approaches have led to devices with high rectification, namely p-type ZnCo2O4 and NiO on n-type ZnO and amorphous zinc-tin-oxide. Subsequent bipolar devices and applications such as photodetectors, solar cells, junction field-effect transistors and integrated circuits like inverters and ring oscillators are discussed. The tremendous progress shows that bipolar oxide electronics has evolved from the exploration of various materials and heterostructures to the demonstration of functioning integrated circuits. Therefore a viable, facile and high performance technology is ready for further exploitation and performance optimization.

  17. Neuroimaging in Bipolar Disorder

    Directory of Open Access Journals (Sweden)

    Kemal Kara

    2013-03-01

    Full Text Available Bipolar disorder is characterized by recurrent attacks, significantly disrupts the functionality of a chronic mental disorder. Although there is growing number of studies on the neurobiological basis of the disorder, the pathophysiology has not yet been clearly understood. Structural and functional imaging techniques present a better understanding of the etiology of bipolar disorder and has contributed significantly to the development of the diagnostic approach. Recent developments in brain imaging modalities have let us learn more about the underlying abnormalities in neural systems of bipolar patients. Identification of objective biomarkers would help to determine the pathophysiology of bipolar disorder, a disorder which causes significant deterioration in neurocognitive and emotional areas.

  18. Management of bipolar depression

    Directory of Open Access Journals (Sweden)

    Jae Seung Chang

    2011-01-01

    Full Text Available Patients with bipolar disorder spend more time in a depressed than manic state, even with individualized treatment. To date, bipolar depression is often misdiagnosed and ineffectively managed both for acute episodes and residual symptoms. This review attempts to summarize the current status of available treatment strategies in the treatment of bipolar depression. For acute and prophylactic treatment, a substantial body of evidence supports the antidepressive efficacy of lithium for bipolar disorders and its antisuicidal effects. Among numerous anticonvulsants with mood-stabilizing properties, valproate and lamotrigine could be first-line options for bipolar depression. Due to receptor profile, mood-stabilizing properties of second-generation antipsychotics have been explored, and up to date, quetiapine and olanzapine appear to be a reasonable option for bipolar depression. The usefulness of antidepressants in bipolar depression is still controversial. Current guidelines generally recommend the cautious antidepressant use in combination with mood stabilizers to reduce the risk of mood elevation or cycle acceleration. Results from clinical trials on psychosocial intervention are promising, especially when integrated with pharmacotherapy. Most patients with bipolar depression need individualized and combined treatment, although the published evidence on this type of treatment strategy is limited. Future studies on the utility of currently available agents and modalities including psychosocial intervention are required.

  19. STRUCTURE OF AMORPHOUS SOLID INTERFACES USING COMPOSITIONALLY MODULATED SUPERLATTICES

    OpenAIRE

    Persans, P.; Ruppert, A.; Abeles, B.; Tiedje, T.; Stasiewski, H.

    1985-01-01

    We demonstrate the use of amorphous superlattice structures combined with quantitative Raman spectroscopy to study the extent of intermixing at as-grown a-Si : H/a-Ge : H solid-solid interfaces. We find that the interface can be described by ~ one monolayer of randomly mixed Si and Ge bounded by pure materials.

  20. Pulsed laser deposited GeTe-rich GeTe-Sb2Te3 thin films

    Science.gov (United States)

    Bouška, M.; Pechev, S.; Simon, Q.; Boidin, R.; Nazabal, V.; Gutwirth, J.; Baudet, E.; Němec, P.

    2016-05-01

    Pulsed laser deposition technique was used for the fabrication of Ge-Te rich GeTe-Sb2Te3 (Ge6Sb2Te9, Ge8Sb2Te11, Ge10Sb2Te13, and Ge12Sb2Te15) amorphous thin films. To evaluate the influence of GeTe content in the deposited films on physico-chemical properties of the GST materials, scanning electron microscopy with energy-dispersive X-ray analysis, X-ray diffraction and reflectometry, atomic force microscopy, Raman scattering spectroscopy, optical reflectivity, and sheet resistance temperature dependences as well as variable angle spectroscopic ellipsometry measurements were used to characterize as-deposited (amorphous) and annealed (crystalline) layers. Upon crystallization, optical functions and electrical resistance of the films change drastically, leading to large optical and electrical contrast between amorphous and crystalline phases. Large changes of optical/electrical properties are accompanied by the variations of thickness, density, and roughness of the films due to crystallization. Reflectivity contrast as high as ~0.21 at 405 nm was calculated for Ge8Sb2Te11, Ge10Sb2Te13, and Ge12Sb2Te15 layers.

  1. Neuroinflammation in bipolar disorders

    Directory of Open Access Journals (Sweden)

    Georgios D Kotzalidis

    2015-01-01

    Full Text Available Recent literature based on peripheral immunity findings speculated that neuroinflammation, with its connection to microglial activation, is linked to bipolar disorder. The endorsement of the neuroinflammatory hypotheses of bipolar disorder requires the demonstration of causality, which requires longitudinal studies. We aimed to review the evidence for neuroinflammation as a pathogenic mechanism of the bipolar disorder. We carried out a hyper inclusive PubMed search using all appropriate neuroinflammation-related terms and crossed them with bipolar disorder-related terms. The search produced 310 articles and the number rose to 350 after adding articles from other search engines and reference lists. Twenty papers were included that appropriately tackled the issue of the presence (but not of its pathophysiological role of neuroinflammation in bipolar disorder. Of these, 15 were postmortem and 5 were carried out in living humans. Most articles were consistent with the presence of neuroinflammation in bipolar disorder, but factors such as treatment may mask it. All studies were cross-sectional, preventing causality to be inferred. Thus, no inference can be currently made about the role of neuroinflammation in bipolar disorder, but a link is likely. The issue remains little investigated, despite an excess of reviews on this topic.

  2. Types of Bipolar Disorder

    Science.gov (United States)

    ... improve the lives of people who have mood disorders. The Power of Peers DBSA envisions wellness for people who live with depression and bipolar disorder. Because DBSA was created for and is led ...

  3. Thermal transport in amorphous materials: a review

    Science.gov (United States)

    Wingert, Matthew C.; Zheng, Jianlin; Kwon, Soonshin; Chen, Renkun

    2016-11-01

    Thermal transport plays a crucial role in performance and reliability of semiconductor electronic devices, where heat is mainly carried by phonons. Phonon transport in crystalline semiconductor materials, such as Si, Ge, GaAs, GaN, etc, has been extensively studied over the past two decades. In fact, study of phonon physics in crystalline semiconductor materials in both bulk and nanostructure forms has been the cornerstone of the emerging field of ‘nanoscale heat transfer’. On the contrary, thermal properties of amorphous materials have been relatively less explored. Recently, however, a growing number of studies have re-examined the thermal properties of amorphous semiconductors, such as amorphous Si. These studies, which included both computational and experimental work, have revealed that phonon transport in amorphous materials is perhaps more complicated than previously thought. For instance, depending on the type of amorphous materials, thermal transport occurs via three types of vibrations: propagons, diffusons, and locons, corresponding to the propagating, diffusion, and localized modes, respectively. The relative contribution of each of these modes dictates the thermal conductivity of the material, including its magnitude and its dependence on sample size and temperature. In this article, we will review the fundamental principles and recent development regarding thermal transport in amorphous semiconductors.

  4. Bipolar Affective Disorder and Migraine

    Directory of Open Access Journals (Sweden)

    Birk Engmann

    2012-01-01

    Full Text Available This paper consists of a case history and an overview of the relationship, aetiology, and treatment of comorbid bipolar disorder migraine patients. A MEDLINE literature search was used. Terms for the search were bipolar disorder bipolar depression, mania, migraine, mood stabilizer. Bipolar disorder and migraine cooccur at a relatively high rate. Bipolar II patients seem to have a higher risk of comorbid migraine than bipolar I patients have. The literature on the common roots of migraine and bipolar disorder, including both genetic and neuropathological approaches, is broadly discussed. Moreover, bipolar disorder and migraine are often combined with a variety of other affective disorders, and, furthermore, behavioural factors also play a role in the origin and course of the diseases. Approach to treatment options is also difficult. Several papers point out possible remedies, for example, valproate, topiramate, which acts on both diseases, but no first-choice treatments have been agreed upon yet.

  5. Bipolar battery construction

    Science.gov (United States)

    Rippel, Wally E. (Inventor); Edwards, Dean B. (Inventor)

    1981-01-01

    A lightweight, bipolar battery construction for lead acid batteries in which a plurality of thin, rigid, biplates each comprise a graphite fiber thermoplastic composition in conductive relation to lead stripes plated on opposite flat surfaces of the plates, and wherein a plurality of nonconductive thermoplastic separator plates support resilient yieldable porous glass mats in which active material is carried, the biplates and separator plates with active material being contained and maintained in stacked assembly by axial compression of the stacked assembly. A method of assembling such a bipolar battery construction.

  6. Hydrogen Bonding in Hydrogenated Amorphous Germanium

    Institute of Scientific and Technical Information of China (English)

    M.S.Abo-Ghazala; S. Al Hazmy

    2004-01-01

    Thin films of hydrogenated amorphous germanium (a-Ge:H) were prepared by radio frequency glow discharge deposition at various substrate temperatures. The hydrogen distribution and bonding structure in a-Ge:H were discussed based on infrared absorption data. The correlation between infrared absorption spectra and hydrogen effusion measurements was used to determine the proportionality constant for each vibration mode of the Ge-H bonds. The results reveal that the bending mode appearing at 835 cm?1 is associated with the Ge-H2 (dihydride) groups on the internal surfaces of voids. While 1880 cm?1 is assigned to vibrations of Ge-H (monohydride) groups in the bulk, the 2000 cm?1 stretching mode is attributed to Ge-H and Ge-H2 bonds located on the surfaces of voids. For films associated with bending modes in the infrared spectra, the proportionality constant values of the stretching modes near 1880 and 2000 cm?1 are found to be lower than those of films which had no corresponding bending modes.

  7. Development, optimization and characterization of thin film materials and structures of tetrahedrally bonded amorphous semiconductors II. Final report; Entwicklung, Optimierung und Charakterisierung von Duennschichtmaterialien und -strukturen sowie Grenzflaechen fuer photovoltaische Anwendungen tetraedrisch gebundener Halbleiterschichten II (Basisforschung a-Si/a-Ge). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, B.; Oechsner, H.

    1998-07-31

    In a comprehensive study we have investigated the effect of the most important deposition parameters on the electronic and microstructural properties of a-Si:H films, deposited by the thermocatalytic CVD, also called hot wire (HW) CVD. This method was found to be an attractive alternative to the plasma enhanced CVD realizing the deposition of amorphous and microcrystalline semiconductor films for solar cell application. Using relatively simple equipment device quality material can be deposited with high rates and large flexibility. Due to results obtained by thin film growth investigations employing the in-situ ellipsometry the material quality could be optimized in terms of microstructural properties. With the invention of a special process control, the microstructural interface engineering, the thermocatalytic CVD a-Si:H material was integrated in solar cells with a conversion efficiency of up to 10.2%. This value was obtained without using highly reflecting rear contacts and, even more, two until now unavoidable `air breaks`. The knowledge about the relationship between microstructure and stability, which was gained during the investigation within the project, enabled us to open up new ways to reduce the degradation of solar cells containing HW-a-Si:H. In that way solar cells with the same initial conversion efficiency but improved stability have been produced, depositing the HW-a-Si:H i-layer with moderate H-dilution. Also {mu}c-Si:H, a-SiGe:H, and a-Ge:H films could be deposited with large rates and high quality applying the TCCVD method. These materials which are important for stacked cell application could be integrated with good (a-SiGe:H) and less good effort ({mu}c-Si:H, a-Ge:H) into solar cell structures. (orig.) [Deutsch] Intensive und grundlegende Untersuchungen im Rahmen dieses Vorhabens haben ergeben, dass sog. `Hot wire (HW)` oder `thermokatalytische (TC)` CVD-Verfahren eine aeusserst attraktive Alternative zur Abscheidung von amorphem und

  8. Mechanism of Germanium-Induced Perimeter Crystallization of Amorphous Silicon

    OpenAIRE

    Hakim, M. M. A.; Ashburn, P.

    2007-01-01

    We report a study aimed at highlighting the mechanism of a new amorphous silicon crystallization phenomenon that originates from the perimeter of a germanium layer during low-temperature annealing (500°C). Results are reported on doped and undoped amorphous silicon films, with thicknesses in the range 40–200 nm, annealed at a temperature of 500 or 550°C. A comparison is made of crystallization arising from Ge and SiGe layers and the role of damage from a high-dose fluorine implant is investig...

  9. Bipolar Disorder in Turkey

    Directory of Open Access Journals (Sweden)

    Bulent Kadri Gultekin

    2014-06-01

    Full Text Available Assessment of studies related with bipolar disorder in Turkey did not reveal an epidemiologically qualified field study. Most of the studies are hospital based or clinical studies which did not include a systematical scanning and did not aim to collect any epidemiological data and transfer information to health authorities. The generalizability of these studies to our community is far from being valid and reliable. On the other hand, a profile which will be created by reviewing the findings of these studies performed in various regions of Turkey will have a contribution to knowing the and ldquo;unique to us and rdquo; features of bipolar disorder and determining cultural risk factors. All this information can constitute a basis for formation and development of public mental health services related with bipolar disorder. In Turkey, the need for epidemiologically significant, polycentric, public sampled studies with broad participation is indispensable. Although our psychiatric epidemiology and clinical studies include necessary scientific basis, they are not powerful enough to evaluate the authentic and progressional relations such as rapid urbanization and immigration. The aim of this review is to evaluate and discuss prominent epidemiological findings, deficiencies and possibile future activities related with studies conducted in Turkey about bipolar disorder.. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(2.000: 199-209

  10. Electrical properties of amorphous chalcogenide/silicon heterojunctions modified by ion implantation

    OpenAIRE

    Fedorenko, Yanina G.; Hughes, Mark A.; Colaux, Julien L.; Jeynes, C.; Gwilliam, Russell M.; Homewood, Kevin P.; Yao, Jin; Hewak, Dan W.; Lee, Tae-Hoon; Elliott, Stephen R; Gholipour, B.; Curry, Richard J.

    2014-01-01

    Doping of amorphous chalcogenide films of rather dissimilar bonding type and resistivity, namely, Ga-La-S, GeTe, and Ge-Sb-Te by means of ion implantation of bismuth is considered. To characterize defects induced by ion-beam implantation space-charge-limited conduction and capacitance-voltage characteristics of amorphous chalcogenide/silicon heterojunctions are investigated. It is shown that ion implantation introduces substantial defect densities in the films and their interfaces with silico...

  11. Corrosion resistant amorphous alloys

    International Nuclear Information System (INIS)

    A review of publication data on corrosion resistance of amorphous alloys and the methods of amorphization of surface layers of massive materials (laser treatment, iron implantation, detonation-gas spraying, cathode and ion sputtering, electrodeposition) was made. A study was made on corrosion properties of Fe66Cr11B10Si4 alloy in cast state and after laser irradiation, rendering the surface amorphous as well as the samples of Arenco iron and steel 20 with ion-plasma coatings of Fe-Cr-Ni-Ti alloy. It was established that amorphous coatings posses much higher corrosion resistance as compared to crystalline alloys on the same base

  12. BIPOLAR DISORDER IN ADULTS

    Directory of Open Access Journals (Sweden)

    Yadav Jaya

    2013-06-01

    Full Text Available Bipolar disorder is a chronic illness, which may require life-long treatment. Patients will spend 3-5 times more days in the depressed episode then in the manic phase. Due to this variability in episodes, polypharmacy is used quite frequently in practice, though the evidence to do this remains quite limited. Many positive and negative outcomes can occur from this practice. Bipolar disorder is the 6th leading cause of disability in the developed world among those between the ages 15 and 44 years age groups. Serotonin is one of the neurotransmitter in the brain, and one of that strongly affects the person mood. Clozapine (clozaril, olanzapine (zyperexa, risperidone (Risperdal, and ziprasidone (zeldox and the clozapine may be helpful as mood stabilizer for people who do not respond to lithium and anticonvulsant.

  13. Epilepsy and bipolar disorder.

    Science.gov (United States)

    Knott, Sarah; Forty, Liz; Craddock, Nick; Thomas, Rhys H

    2015-11-01

    It is well recognized that mood disorders and epilepsy commonly co-occur. Despite this, our knowledge regarding the relationship between epilepsy and bipolar disorder is limited. Several shared features between the two disorders, such as their episodic nature and potential to run a chronic course, and the efficacy of some antiepileptic medications in the prophylaxis of both disorders, are often cited as evidence of possible shared underlying pathophysiology. The present paper aims to review the bidirectional associations between epilepsy and bipolar disorder, with a focus on epidemiological links, evidence for shared etiology, and the impact of these disorders on both the individual and wider society. Better recognition and understanding of these two complex disorders, along with an integrated clinical approach, are crucial for improved evaluation and management of comorbid epilepsy and mood disorders.

  14. Life expectancy in bipolar disorder

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Vradi, Eleni; Andersen, Per Kragh

    2015-01-01

    OBJECTIVE: Life expectancy in patients with bipolar disorder has been reported to be decreased by 11 to 20 years. These calculations are based on data for individuals at the age of 15 years. However, this may be misleading for patients with bipolar disorder in general as most patients have a later...... onset of illness. The aim of the present study was to calculate the remaining life expectancy for patients of different ages with a diagnosis of bipolar disorder. METHODS: Using nationwide registers of all inpatient and outpatient contacts to all psychiatric hospitals in Denmark from 1970 to 2012 we...... remaining life expectancy in bipolar disorder and that of the general population decreased with age, indicating that patients with bipolar disorder start losing life-years during early and mid-adulthood. CONCLUSIONS: Life expectancy in bipolar disorder is decreased substantially, but less so than previously...

  15. Bipolar Disorder and Cancer

    OpenAIRE

    Sermin Kesebir; Arzu Bayrak

    2012-01-01

    Prevalence studies and studies on causation relations have shown that the relation between psychiatric disorders and chronic physical diseases is neglected. For heterogeneous diseases an increasing number of susceptibility variants are being defined. Alzheimer disease, bipolar disorder, breast and prostate cancer, coronary artery disease, Chron's disease, systemic lupus eritematosus, type 1 and type 2 diabetes mellitus are mentioned together with epigenetic concept. In acrocentric zone of chr...

  16. Treatment of bipolar disorder

    OpenAIRE

    Geddes, John R.; Miklowitz, David J.

    2013-01-01

    We review recent developments in the acute and long-term treatment of bipolar disorder and identify promising future routes to therapeutic innovation. Overall, advances in drug treatment remain quite modest. Antipsychotic drugs are effective in the acute treatment of mania; their efficacy in the treatment of depression is variable with the clearest evidence for quetiapine. Despite their widespread use, considerable uncertainty and controversy remains about the use of antidepressant drugs in t...

  17. Prophylactic treatment in bipolar disorder

    OpenAIRE

    Eroğlu, Meliha Zengin; Özpoyraz, Nurgül; Tamam, Lut

    2014-01-01

    Objective: The aim of this study was to determine the prophylactic treatment response and its relationship between clinical variables among the bipolar disorder patient group followed up in the Bipolar Disorder Unit of Psychiatry Department of Cukurova University Faculty of Medicine. Methods: One hundred patients, in euthymic period, diagnosed as bipolar disorder, were included in this study. “Affective Disorders Patient Registry Form” developed by our unit, SCID-I, Young Mani Rating Scale...

  18. Mathematical models of bipolar disorder

    OpenAIRE

    Daugherty, D; Roque-Urrea, T; Urrea-Roque, J; DE TROYER, J; Wirkus, S; Porter, M. A.

    2009-01-01

    We use limit cycle oscillators to model bipolar II disorder, which is characterized by alternating hypomanic and depressive episodes and afflicts about 1% of the United States adult population. We consider two non-linear oscillator models of a single bipolar patient. In both frameworks, we begin with an untreated individual and examine the mathematical effects and resulting biological consequences of treatment. We also briefly consider the dynamics of interacting bipolar II individuals using ...

  19. The Genetics of Bipolar Disorder

    OpenAIRE

    Jennifer H Barnett; Smoller, Jordan W.

    2009-01-01

    Bipolar disorder is a mood disorder characterized by impairing episodes of mania and depression. Twin studies have established that bipolar disorder is among the most heritable of medical disorders and efforts to identify specific susceptibility genes have intensified over the past two decades. The search for genes influencing bipolar disorder has been complicated by a paucity of animal models, limited understanding of pathogenesis, and the genetic and phenotypic complexity of the syndrome. L...

  20. Mathematical Models of Bipolar Disorder

    OpenAIRE

    Daugherty, Darryl; Roque-Urrea, Tairi; Urrea-Roque, John; Snyder, Jessica; Wirkus, Stephen; Mason A. Porter

    2003-01-01

    We use limit cycle oscillators to model Bipolar II disorder, which is characterized by alternating hypomanic and depressive episodes and afflicts about one percent of the United States adult population. We consider two nonlinear oscillator models of a single bipolar patient. In both frameworks, we begin with an untreated individual and examine the mathematical effects and resulting biological consequences of treatment. We also briefly consider the dynamics of interacting bipolar II individual...

  1. Childhood trauma in bipolar disorder

    OpenAIRE

    Watson, S; Gallagher, P.; Dougall, D.; R Porter; Moncrieff, J.; Ferrier, I. N.; Young, A. H.

    2014-01-01

    Objective: There has been little investigation of early trauma in bipolar disorder despite evidence that stress impacts on the course of this illness. We aimed to compare the rates of childhood trauma in adults with bipolar disorder to a healthy control group, and to investigate the impact of childhood trauma on the clinical course of bipolar disorder. Methods: Retrospective assessment of childhood trauma was conducted using the Childhood Trauma Questionnaire (CTQ) in 60 outpatients with bipo...

  2. Bipolar Disorder in Children and Teens

    Science.gov (United States)

    ... is in crisis. What do I do? Share Bipolar Disorder in Children and Teens Download PDF Download ePub ... brochure will give you more information. What is bipolar disorder? Bipolar disorder is a serious brain illness. It ...

  3. Bipolar Disorder and Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Sermin Kesebir

    2010-04-01

    Full Text Available Comorbid endocrine and cardiovascular situations with bipolar disorder usually result from the bipolar disorder itself or as a consequence of its treatment. With habits and lifestyle, genetic tendency and side effects, this situation is becoming more striking. Subpopulations of bipolar disorders patients should be considered at high risk for diabetes mellitus. The prevalence of diabetes mellitus in bipolar disorder may be three times greater than in the general population. Comorbidity of diabetes causes a pathophysiological overlapping in the neurobiological webs of bipolar cases. Signal mechanisms of glycocorticoid/insulin and immunoinflammatory effector systems are junction points that point out the pathophysiology between bipolar disorder and general medical cases susceptible to stress. Glycogen synthetase kinase (GSK-3 is a serine/treonine kinase and inhibits the transport of glucose stimulated by insulin. It is affected in diabetes, cancer, inflammation, Alzheimer disease and bipolar disorder. Hypoglycemic effect of lithium occurs via inhibiting glycogen synthetase kinase. When comorbid with diabetes, the other disease -for example bipolar disorder, especially during its acute manic episodes-, causes a serious situation that presents its influences for a lifetime. Choosing pharmacological treatment and treatment adherence are another important interrelated areas. The aim of this article is to discuss and review the etiological, clinical and therapeutic properties of diabetes mellitus and bipolar disorder comorbidity.

  4. Silicon-germanium Single-heterojunction Bipolar Transistor

    Directory of Open Access Journals (Sweden)

    G.M. Khanduri

    2006-04-01

    Full Text Available The cutoff frequency performance of an NPN Si/SiGe/SiGe single-heterojunction bipolartransistor (SiGe SHBT at high collector current densities has been analysed using a 2-D MEDICIdevice simulator. A conventional NPN Si/SiGe/Si double-heterojunction bipolar transistor(SiGe DHBT having uniform 20 atomic per cent of germanium in the base region has beeninvestigated for comparison. The analysis shows the formation of a retarding potential barrierfor minority carrier electrons at the base-collector heterojunction of the DHBT structure. Whereas,the base-collector homojunction of the SiGe SHBT structure, having a uniform 15 atomic percent of germanium profile in its base and collector, inhibits the formation of such a retardingpotential barrier, the SHBT structure with a base-collector homojunction shows an improvedcutoff frequency at high collector current density in comparison with conventional SiGe DHBT,which makes it more promising for high speed, scaled down, field-specific applications.

  5. Amorphization of hard crystalline materials by electrosprayed nanodroplet impact

    International Nuclear Information System (INIS)

    A beam of electrosprayed nanodroplets impacting on single-crystal silicon amorphizes a thin surface layer of a thickness comparable to the diameter of the drops. The phase transition occurs at projectile velocities exceeding a threshold, and is caused by the quenching of material melted by the impacts. This article demonstrates that the amorphization of silicon is a general phenomenon, as nanodroplets impacting at sufficient velocity also amorphize other covalently bonded crystals. In particular, we bombard single-crystal wafers of Si, Ge, GaAs, GaP, InAs, and SiC in a range of projectile velocities, and characterize the samples via electron backscatter diffraction and transmission electron microscopy to determine the aggregation state under the surface. InAs requires the lowest projectile velocity to develop an amorphous layer, followed by Ge, Si, GaAs, and GaP. SiC is the only semiconductor that remains fully crystalline, likely due to the relatively low velocities of the beamlets used in this study. The resiliency of each crystal to amorphization correlates well with the specific energy needed to melt it except for Ge, which requires projectile velocities higher than expected

  6. Amorphous iron (II) carbonate

    DEFF Research Database (Denmark)

    Sel, Ozlem; Radha, A.V.; Dideriksen, Knud;

    2012-01-01

    Abstract The synthesis, characterization and crystallization energetics of amorphous iron (II) carbonate (AFC) are reported. AFC may form as a precursor for siderite (FeCO3). The enthalpy of crystallization (DHcrys) of AFC is similar to that of amorphous magnesium carbonate (AMC) and more...

  7. 用气态源分子束外延生长法制备Si/SiGe/Si nPn异质结双极晶体管%Growth of Si/SiGe/Si Heterojunction Bipolar Transistors by Gas-Source Molecular Beam Epitaxy

    Institute of Scientific and Technical Information of China (English)

    刘学锋; 李晋闽; 孔梅影; 黄大定; 李建平; 林兰英

    2000-01-01

    用气态源分子束外延法制备了Si/SiGe/Si npn异质结双极晶体管.晶体管基区Ge组分为0.12,B掺杂浓度为1.5×101 9cm-3, SiGe合金厚度约45nm.直流特性测试表明,共发射极直流放大倍数约50,击穿电压VCE约9V;射频特性测试结果表明,晶体管的截止频率为7GHz,最高振荡频率为2.5GHz.

  8. Radiation damage of SiGe HBT Technologies at different bias configurations

    CERN Document Server

    Ullán, M; Lozano, M; Pellegrini, G; Knoll, D; Heinemann, B

    2008-01-01

    SiGe BiCMOS technologies are being proposed for the Front-end readout of the detectors in the middle region of the ATLAS-Upgrade. The radiation hardness of the SiGe bipolar transistors is being assessed for this application through irradiations with different particles. Biasing conditions during irradiation of bipolar transistors or circuits have an influence on the damage and there is a risk of erroneous results. We have performed several irradiation experiments of SiGe devices from IHP in different bias conditions. We have observed a systematic trend in gamma irradiations, showing a smaller damage in transistors irradiated biased compared to shorted or floating terminals.

  9. An Electrochromic Bipolar Membrane Diode.

    Science.gov (United States)

    Malti, Abdellah; Gabrielsson, Erik O; Crispin, Xavier; Berggren, Magnus

    2015-07-01

    Conducting polymers with bipolar membranes (a complementary stack of selective membranes) may be used to rectify current. Integrating a bipolar membrane into a polymer electrochromic display obviates the need for an addressing backplane while increasing the device's bistability. Such devices can be made from solution-processable materials.

  10. Genetics of bipolar disorder

    Directory of Open Access Journals (Sweden)

    Kerner B

    2014-02-01

    Full Text Available Berit Kerner Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA Abstract: Bipolar disorder is a common, complex genetic disorder, but the mode of transmission remains to be discovered. Many researchers assume that common genomic variants carry some risk for manifesting the disease. The research community has celebrated the first genome-wide significant associations between common single nucleotide polymorphisms (SNPs and bipolar disorder. Currently, attempts are under way to translate these findings into clinical practice, genetic counseling, and predictive testing. However, some experts remain cautious. After all, common variants explain only a very small percentage of the genetic risk, and functional consequences of the discovered SNPs are inconclusive. Furthermore, the associated SNPs are not disease specific, and the majority of individuals with a “risk” allele are healthy. On the other hand, population-based genome-wide studies in psychiatric disorders have rediscovered rare structural variants and mutations in genes, which were previously known to cause genetic syndromes and monogenic Mendelian disorders. In many Mendelian syndromes, psychiatric symptoms are prevalent. Although these conditions do not fit the classic description of any specific psychiatric disorder, they often show nonspecific psychiatric symptoms that cross diagnostic boundaries, including intellectual disability, behavioral abnormalities, mood disorders, anxiety disorders, attention deficit, impulse control deficit, and psychosis. Although testing for chromosomal disorders and monogenic Mendelian disorders is well established, testing for common variants is still controversial. The standard concept of genetic testing includes at least three broad criteria that need to be fulfilled before new genetic tests should be introduced: analytical validity, clinical validity, and clinical utility. These criteria are

  11. Scientific attitudes towards bipolar disorders

    Directory of Open Access Journals (Sweden)

    Mohammad-Hossein Biglu

    2014-02-01

    Full Text Available Introduction: Bipolar disorder is a psychiatric condition that is also called manic-depressive disease. It causes unusual changes in mood, energy, activity levels, and the ability to carry out day-to-day tasks. In the present study, 3 sets of data were considered and analyzed: first, all papers categorized under Bipolar Disorders in Science Citation Index Expanded (SCI-E database through 2001-2011; second, papers published by the international journal of Bipolar Disorders indexed in SCI-E during a period of 11 years; and third, all papers distributed by the international journal of Bipolar Disorders indexed in MEDLINE during the period of study. Methods: The SCI-E database was used to extract all papers indexed with the topic of Bipolar Disorders as well as all papers published by The International Journal of Bipolar Disorders. Extraction of data from MEDLINE was restricted to the journals name from setting menu. The Science of Science Tool was used to map the co-authorship network of papers published by The International Journal of Bipolar Disorders through 2009-2011. Results: Analysis of data showed that the majority of publications in the subject area of bipolar disorders indexed in SCI-E were published by The International Journal of Bipolar Disorders. Although journal articles consisted of 59% of the total publication type in SCI-E, 65% of publications distributed by The Journal of Bipolar Disorders were in the form of meetingabstracts. Journal articles consisted of only 23% of the total publications. USA was the leading country regarding sharing data in the field of bipolar disorders followed by England, Canada, and Germany. Conclusion: The editorial policy of The International Journal of Bipolar Disorders has been focused on new themes and new ways of researching in the subject area of bipolar disorder. Regarding the selection of papers for indexing, the SCI-E database selects data more comprehensively than MEDLINE. The number of papers

  12. Tobacco Use in Bipolar Disorder

    Science.gov (United States)

    Thomson, Daniel; Berk, Michael; Dodd, Seetal; Rapado-Castro, Marta; Quirk, Shae E.; Ellegaard, Pernille K.; Berk, Lesley; Dean, Olivia M.

    2015-01-01

    Tobacco use in mental health in general and bipolar disorder in particular remains disproportionally common, despite declining smoking rates in the community. Furthermore, interactions between tobacco use and mental health have been shown, indicating the outcomes for those with mental health disorders are impacted by tobacco use. Factors need to be explored and addressed to improve outcomes for those with these disorders and target specific interventions for people with psychiatric illness to cease tobacco smoking. In the context of bipolar disorder, this review explores; the effects of tobacco smoking on symptoms, quality of life, suicidal behaviour, the biological interactions between tobacco use and bipolar disorder, the interactions between tobacco smoking and psychiatric medications, rates and factors surrounding tobacco smoking cessation in bipolar disorder and suggests potential directions for research and clinical translation. The importance of this review is to bring together the current understanding of tobacco use in bipolar disorder to highlight the need for specific intervention. PMID:25912533

  13. Bipolar Disorder and Childhood Trauma

    Directory of Open Access Journals (Sweden)

    Evrim Erten

    2015-06-01

    Full Text Available Bipolar disorder is a chronic disorder in which irregular course of depressive, mania or mixed episodes or a complete recovery between episodes can be observed. The studies about the effects of traumatic events on bipolar disorder showed that they had significant and long-term effects on the symptoms of the disorder. Psychosocial stress might change the neurobiology of bipolar disorder over time. The studies revealed that the traumatic events could influence not only the onset of the disorder but also the course of the disorder and in these patients the rate of suicide attempt and comorbid substance abuse might increase. Bipolar patients who had childhood trauma had an earlier onset, higher number of episodes and comorbid disorders. In this review, the relationship between childhood trauma and bipolar disorder is reviewed. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2015; 7(2: 157-165

  14. Trehalose amorphization and recrystallization.

    Science.gov (United States)

    Sussich, Fabiana; Cesàro, Attilio

    2008-10-13

    The stability of the amorphous trehalose prepared by using several procedures is presented and discussed. Amorphization is shown to occur by melting (T(m)=215 degrees C) or milling (room temperature) the crystalline anhydrous form TRE-beta. Fast dehydration of the di-hydrate crystalline polymorph, TRE-h, also produces an amorphous phase. Other dehydration procedures of TRE-h, such as microwave treatment, supercritical extraction or gentle heating at low scan rates, give variable fractions of the polymorph TRE-alpha, that undergo amorphization upon melting (at lower temperature, T(m)=130 degrees C). Additional procedures for amorphization, such as freeze-drying, spray-drying or evaporation of trehalose solutions, are discussed. All these procedures are classified depending on the capability of the undercooled liquid phase to undergo cold crystallization upon heating the glassy state at temperatures above the glass transition temperature (T(g)=120 degrees C). The recrystallizable amorphous phase is invariably obtained by the melt of the polymorph TRE-alpha, while other procedures always give an amorphous phase that is unable to crystallize above T(g). The existence of two different categories is analyzed in terms of the transformation paths and the hypothesis that the systems may exhibit different molecular mobilities.

  15. Physics of amorphous metals

    CERN Document Server

    Kovalenko, Nikolai P; Krey, Uwe

    2008-01-01

    The discovery of bulk metallic glasses has led to a large increase in the industrial importance of amorphous metals, and this is expected to continue. This book is the first to describe the theoretical physics of amorphous metals, including the important theoretical development of the last 20 years.The renowned authors stress the universal aspects in their description of the phonon or magnon low-energy excitations in the amorphous metals, e.g. concerning the remarkable consequences of the properties of these excitations for the thermodynamics at low and intermediate temperatures. Tunneling

  16. Enhanced formation of Ge nanocrystals in Ge : SiO2 layers by swift heavy ions

    International Nuclear Information System (INIS)

    In this paper we report the ability of swift heavy Xe ions with an energy of 480 MeV and a fluence of 1012 cm-2 to enhance the formation of Ge nanocrystals within SiO2 layers with variable Ge contents. These Ge-SiO2 films were fabricated by the co-sputtering of Ge and quartz sources which followed various annealing procedures. In particular, we found that the irradiation of the Ge : SiO2 films with subsequent annealing at 500 °C leads to the formation of a high concentration of nanocrystals (NCs) with a size of 2-5 nm, whereas without irradiation only amorphous inclusions were observed. This effect, as evidenced by Raman spectra, is enhanced by pre-irradiation at 550 °C and post-irradiation annealing at 600 °C, which also leads to the observation of room temperature visible photoluminescence. (paper)

  17. Heteroepitaxial Ge-on-Si by DC magnetron sputtering

    International Nuclear Information System (INIS)

    The growth of Ge on Si(100) by DC Magnetron Sputtering at various temperatures is studied by Spectroscopic Ellipsometry and Transmission Electron Microscopy. Smooth heteroepitaxial Ge films are prepared at relatively low temperatures of 380°C. Typical Stransky-Krastanov growth is observed at 410°C. At lower temperatures (320°C), films are essentially amorphous with isolated nanocrystallites at the Si-Ge interface. A minor oxygen contamination at the interface, developing after ex-situ oxide removal, is not seen to hinder epitaxy. Compensation of dislocation-induced acceptors in Ge by sputtering from n-doped targets is proposed.

  18. Electronic transport in amorphous phase-change materials

    Energy Technology Data Exchange (ETDEWEB)

    Luckas, Jennifer Maria

    2012-09-14

    Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. Starting from a brief introduction of the physics of phase-change materials this thesis summarizes the most important models behind electrical switching and resistance drift with the aim to discuss the role of localized defect states. The centerpiece of this thesis is the investigation of defects state densities in different amorphous phase-change materials and electrical switching chalcogenides. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Deflection Spectroscopy, a sophisticated band model for the disordered phase of the binary phase-change alloy GeTe has been developed. By this direct experimental approach the band-model for a-Ge

  19. Electronic transport in amorphous phase-change materials

    International Nuclear Information System (INIS)

    Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. Starting from a brief introduction of the physics of phase-change materials this thesis summarizes the most important models behind electrical switching and resistance drift with the aim to discuss the role of localized defect states. The centerpiece of this thesis is the investigation of defects state densities in different amorphous phase-change materials and electrical switching chalcogenides. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Deflection Spectroscopy, a sophisticated band model for the disordered phase of the binary phase-change alloy GeTe has been developed. By this direct experimental approach the band-model for a-Ge

  20. Amorphous Solid Water:

    DEFF Research Database (Denmark)

    Wenzel, Jack; Linderstrøm-Lang, C. U.; Rice, Stuart A.

    1975-01-01

    The structure factor of amorphous solid D2O deposited from the vapor at 10°K has been obtained by measuring the neutron diffraction spectrum in the wave vector transfer from 0.8 to 12.3 reciprocal angstroms. The results indicate that the phase investigated is amorphous and has a liquiid-like stru......The structure factor of amorphous solid D2O deposited from the vapor at 10°K has been obtained by measuring the neutron diffraction spectrum in the wave vector transfer from 0.8 to 12.3 reciprocal angstroms. The results indicate that the phase investigated is amorphous and has a liquiid...

  1. Asenapine for bipolar disorder

    Directory of Open Access Journals (Sweden)

    Scheidemantel T

    2015-12-01

    Full Text Available Thomas Scheidemantel,1 Irina Korobkova,2 Soham Rej,3,4 Martha Sajatovic1,2 1University Hospitals Case Medical Center, 2Case Western Reserve University School of Medicine, Cleveland, OH, USA; 3Department of Psychiatry, University of Toronto, Toronto, ON, 4Geri PARTy Research Group, Jewish General Hospital, Montreal, QC, Canada Abstract: Asenapine (Saphris® is an atypical antipsychotic drug which has been approved by the US Food and Drug Administration for the treatment of schizophrenia in adults, as well as the treatment of acute manic or mixed episodes of bipolar I in both adult and pediatric populations. Asenapine is a tetracyclic drug with antidopaminergic and antiserotonergic activity with a unique sublingual route of administration. In this review, we examine and summarize the available literature on the safety, efficacy, and tolerability of asenapine in the treatment of bipolar disorder (BD. Data from randomized, double-blind trials comparing asenapine to placebo or olanzapine in the treatment of acute manic or mixed episodes showed asenapine to be an effective monotherapy treatment in clinical settings; asenapine outperformed placebo and showed noninferior performance to olanzapine based on improvement in the Young Mania Rating Scale scores. There are limited data available on the use of asenapine in the treatment of depressive symptoms of BD, or in the maintenance phase of BD. The available data are inconclusive, suggesting the need for more robust data from prospective trials in these clinical domains. The most commonly reported adverse effect associated with use of asenapine is somnolence. However, the somnolence associated with asenapine use did not cause significant rates of discontinuation. While asenapine was associated with weight gain when compared to placebo, it appeared to be modest when compared to other atypical antipsychotics, and its propensity to cause increases in hemoglobin A1c or serum lipid levels appeared to be

  2. Electrical properties of Bi-implanted amorphous chalcogenide films

    International Nuclear Information System (INIS)

    The impact of Bi implantation on the conductivity and the thermopower of GeTe, Ge–Sb–Te, and Ga–La–S films is investigated. The enhanced conductivity appears to be notably sensitive to a dose of an implant. Incorporation of Bi in amorphous chalcogenide films at doses up to 1 × 1015 cm−2 is seen not to change the majority carrier type and activation energy for the conduction process. Higher implantation doses may reverse the majority carrier type in the studied films. Electron conductivity was observed in GeTe films implanted with Bi at a dose of 2 × 1016 cm−2. These studies indicate that native coordination defects present in amorphous chalcogenide semiconductors can be deactivated by means of ion implantation. A substantial density of implantation-induced traps in the studied films and their interfaces with silicon is inferred from analysis of the space-charge-limited current and capacitance-voltage characteristics taken on Au/amorphous chalcogenide/Si structures. - Highlights: • Electron conductivity is observed in Bi-implanted GeTe films. • Higher conductivity in Bi-implanted films stems from increased density of electrically active defects. • Bi implanted in amorphous chalcogenides may promote formation of a more chemically ordered alloy

  3. Electrical properties of Bi-implanted amorphous chalcogenide films

    Energy Technology Data Exchange (ETDEWEB)

    Fedorenko, Yanina G.

    2015-08-31

    The impact of Bi implantation on the conductivity and the thermopower of GeTe, Ge–Sb–Te, and Ga–La–S films is investigated. The enhanced conductivity appears to be notably sensitive to a dose of an implant. Incorporation of Bi in amorphous chalcogenide films at doses up to 1 × 10{sup 15} cm{sup −2} is seen not to change the majority carrier type and activation energy for the conduction process. Higher implantation doses may reverse the majority carrier type in the studied films. Electron conductivity was observed in GeTe films implanted with Bi at a dose of 2 × 10{sup 16} cm{sup −2}. These studies indicate that native coordination defects present in amorphous chalcogenide semiconductors can be deactivated by means of ion implantation. A substantial density of implantation-induced traps in the studied films and their interfaces with silicon is inferred from analysis of the space-charge-limited current and capacitance-voltage characteristics taken on Au/amorphous chalcogenide/Si structures. - Highlights: • Electron conductivity is observed in Bi-implanted GeTe films. • Higher conductivity in Bi-implanted films stems from increased density of electrically active defects. • Bi implanted in amorphous chalcogenides may promote formation of a more chemically ordered alloy.

  4. Risk factors for suicide among children and youths with bipolar spectrum and early bipolar disorder.

    Directory of Open Access Journals (Sweden)

    Aleksandra Rajewska-Rager

    2015-06-01

    the overview of recent years literature available in PubMed/MEDLINE database, including the following search criteria: early onset bipolar disorder, bipolar disorder in children and young people, the spectrum of bipolar disorder, and suicidal ideation, suicidal intent, suicide.

  5. Lattice strain induced phase selection and epitaxial relaxation in crystalline GeTe thin film

    International Nuclear Information System (INIS)

    We report that the lattice strain induced phase selection and epitaxial relaxation in crystalline GeTe thin films by pulsed laser deposition. The single-crystal substrates of MgO and BaF2 are designed to match the lattice of low-temperature α-GeTe phase and high-temperature β-GeTe phase, respectively. The structures of deposited GeTe films show lattice-match dependence rather than temperature dependence. Raman analysis indicates that the α-GeTe to β-GeTe ferroelectric phase transition accompanies an increase of local six-coordinated Ge atoms, which is analogous to the phase transition from amorphous to crystalline for memory application. - Highlights: • Lattice-match dependence in crystalline GeTe growth • The epitaxial relaxation induced by slight misfit strain • Crystalline GeTe is ferroelectric. • The local structure evolution during crystalline GeTe phase transition

  6. Stable, free-standing Ge nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, I.D.; Xu, Q.; Liao, C.Y.; Yi, D.O.; Beeman, J.W.; Liliental-Weber, Z.; Yu, K.M.; Zakharov, D.N.; Ager III, J.W.; Chrzan,D.C.; Haller, E.E.

    2005-01-28

    Free-standing Ge nanocrystals that are stable under ambient conditions have been synthesized in a two-step process. First, nanocrystals with a mean diameter of 5 nm are grown in amorphous SiO{sub 2} by ion implantation followed by thermal annealing. The oxide matrix is then removed by selective etching in diluted HF to obtain free-standing nanocrystals on a Si wafer. After etching, nanocrystals are retained on the surface and the size distribution is not significantly altered. Free-standing nanocrystals are stable under ambient atmospheric conditions, suggesting formation of a self-limiting native oxide layer. For free-standing as opposed to embedded Ge nanocrystals, an additional amorphous-like contribution to the Raman spectrum is observed and is assigned to surface reconstruction-induced disordering of near-surface atoms.

  7. Structural evolution of Ge-rich Si{sub 1−x}Ge{sub x} films deposited by jet-ICPCVD

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yu; Yang, Meng; Wang, Gang [Key Laboratory of Advanced Photonic and Electronic Materials and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Wei, Xiaoxu; Wang, Junzhuan; Li, Yun; Zheng, Youdou; Shi, Yi, E-mail: yshi@nju.edu.cn [Key Laboratory of Advanced Photonic and Electronic Materials and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Collaborative Innovation Center of Advanced Micro-structures, Nanjing University, Nanjing 210093 (China); Zou, Zewen [College of Physics and Electronics Information, Anhui Normal University, Wuhu 241000 (China)

    2015-11-15

    Amorphous Ge-rich Si{sub 1−x}Ge{sub x} films with local Ge-clustering were deposited by dual-source jet-type inductively coupled plasma chemical-vapor deposition (jet-ICPCVD). The structural evolution of the deposited films annealed at various temperatures (Ta) is investigated. Experimental results indicate that the crystallization occurs to form Ge and Si clusters as Ta = 500 °C. With raising Ta up to 900 °C, Ge clusters percolate together and Si diffuses and redistributes to form a Ge/SiGe core/shell structure, and some Ge atoms partially diffuse to the surface as a result of segregation. The present work will be helpful in understanding the structural evolution process of a hybrid SiGe films and beneficial for further optimizing the microstructure and properties.

  8. Formation mechanism of Ge nanocrystals embedded in SiO2 studied by fluorescence x-ray absorption fine structure

    Institute of Scientific and Technical Information of China (English)

    Yan Wen-Sheng; Li Zhong-Rui; Sun Zhi-Hu; Pan Zhi-Yun; Wei Shi-Qiang

    2007-01-01

    This paper reports that the Ge nanocrystals embedded in SiO2 matrix are grown on Si(100) and quartz-glass substrates, and the formation mechanism is systematically studied by using fluorescence x-ray absorption fine structure (XAFS). It is found that the formation of Ge nanocrystals strongly depends on the properties of substrate materials. In the as-prepared samples with Ge molar content of 60%, Ge atoms exist in amorphous Ge (about 36%) and GeO2 (about 24%) phases. At the annealing temperature of 1073 K, on the quartz-glass substrate Ge nanocrystals are generated from crystallization of amorphous Ge, rather than from the direct decomposition of GeO2 in the as-deposited sample.However, on the Si(100) substrate, the Ge nanocrystals are generated partly from crystallization of amorphous Ge, and partly from GeO2 phases through the permutation reaction with Si substrate. Quantitative analysis reveals that about 10% of GeO2 in the as-prepared sample are permuted with Si wafer to form Ge nanocrystals.

  9. Sleep Disturbances in Bipolar Disorder

    OpenAIRE

    Cátia Alves Moreira; Pedro Afonso

    2015-01-01

    Background: Bipolar disorder, characterized by episodes of mania, hypomania and depression is associated with sleep disturbances and circadian rhythm disruption. These changes have significant impact on quality of life and in the disease prognosis. Aims: Review of the main sleep disturbances observed in the bipolar disorder, their clinical impact and the hypothetical pathophysiological mechanisms involved. Methods: We conducted a non-systematic review of the literature in English through rese...

  10. : Genetic heterogeneity of bipolar disorder

    OpenAIRE

    Mathieu, Flavie; Dizier, Marie-Hélène; Etain, Bruno; Jamain, Stéphane; Rietschel, Marcella; Maier, Wolfgang; Albus, Margot; Mckeon, Patrick; Roche, Siobhan; Blackwood, Douglas; Muir, Walter,; Henry, Chantal; Malafosse, Alain; Preisig, Martin; Ferrero, François

    2010-01-01

    Bipolar disorder has a genetic component, but the mode of inheritance remains unclear. A previous genome scan conducted in 70 European families led to detect eight regions linked to bipolar disease. Here, we present an investigation of whether the phenotypic heterogeneity of the disorder corresponds to genetic heterogeneity in these regions using additional markers and an extended sample of families. The MLS statistic was used for linkage analyses. The predivided sample test and the maximum l...

  11. Bipolar spectrum disorders. New perspectives.

    OpenAIRE

    Piver, Andre; Yatham, Lakshmi N.; Raymond W. Lam

    2002-01-01

    OBJECTIVE: To review new perspectives on diagnosis, clinical features, epidemiology, and treatment of bipolar II and related disorders. QUALITY OF EVIDENCE: Articles were identified by searching MEDLINE and ClinPSYCH from January 1994 to August 2001 using the key words bipolar disorder, type II or 2; hypomania; spectrum; or variants. Reference lists from articles were reviewed. Overall, the quality of evidence was not high; we found no randomized controlled trials that specifically addressed ...

  12. Threat sensitivity in bipolar disorder.

    Science.gov (United States)

    Muhtadie, Luma; Johnson, Sheri L

    2015-02-01

    Life stress is a major predictor of the course of bipolar disorder. Few studies have used laboratory paradigms to examine stress reactivity in bipolar disorder, and none have assessed autonomic reactivity to laboratory stressors. In the present investigation we sought to address this gap in the literature. Participants, 27 diagnosed with bipolar I disorder and 24 controls with no history of mood disorder, were asked to complete a complex working memory task presented as "a test of general intelligence." Self-reported emotions were assessed at baseline and after participants were given task instructions; autonomic physiology was assessed at baseline and continuously during the stressor task. Compared to controls, individuals with bipolar disorder reported greater increases in pretask anxiety from baseline and showed greater cardiovascular threat reactivity during the task. Group differences in cardiovascular threat reactivity were significantly correlated with comorbid anxiety in the bipolar group. Our results suggest that a multimethod approach to assessing stress reactivity-including the use of physiological parameters that differentiate between maladaptive and adaptive profiles of stress responding-can yield valuable information regarding stress sensitivity and its associations with negative affectivity in bipolar disorder. (PsycINFO Database Record (c) 2015 APA, all rights reserved). PMID:25688436

  13. The Reliability of III-V semiconductor Heterojunction Bipolar Transistors

    OpenAIRE

    M. Borgarino; Plana, R.; Graffeuil, J; Cattani, L; F. Fantini

    2000-01-01

    The Heterojunction Bipolar Transistor (HBT) features some characteristics that make it a very promising device in the telecom field. For these applications, the reliability is a key issue. The aim of the present paper is to summarise the most relevant reliability concerns, from whose the HBT suffers, as the stability of the ohmic contact, the presence of defects, and the stability of the base dopant. Since in the last years the Si/SiGe HBT has emerged as a strong competitor against the III-V ...

  14. Integrated neurobiology of bipolar disorder

    Directory of Open Access Journals (Sweden)

    Vladimir eMaletic

    2014-08-01

    Full Text Available From a neurobiological perspective there is no such thing as bipolar disorder. Rather, it is almost certainly the case that many somewhat similar, but subtly different, pathological conditions produce a disease state that we currently diagnose as bipolarity. This heterogeneity—reflected in the lack of synergy between our current diagnostic schema and our rapidly advancing scientific understanding of the condition—limits attempts to articulate an integrated perspective on bipolar disorder. However, despite these challenges, scientific findings in recent years are beginning to offer a provisional unified field theory of the disease. This theory sees bipolar disorder as a suite of related neurodevelopmental conditions with interconnected functional abnormalities that often appear early in life and worsen over time. In addition to accelerated loss of volume in brain areas known to be essential for mood regulation and cognitive function, consistent findings have emerged at a cellular level, providing evidence that bipolar disorder is reliably associated with dysregulation of glial-neuronal interactions. Among these glial elements are microglia—the brain’s primary immune elements, which appear to be overactive in the context of bipolarity. Multiple studies now indicate that inflammation is also increased in the periphery of the body in both the depressive and manic phases of the illness, with at least some return to normality in the euthymic state. These findings are consistent with changes in the HPA axis, which are known to drive inflammatory activation. In summary, the very fact that no single gene, pathway or brain abnormality is likely to ever account for the condition is itself an extremely important first step in better articulating an integrated perspective on both its ontological status and pathogenesis. Whether this perspective will translate into the discovery of innumerable more homogeneous forms of bipolarity is one of the great

  15. Targeting astrocytes in bipolar disorder.

    Science.gov (United States)

    Peng, Liang; Li, Baoman; Verkhratsky, Alexei

    2016-06-01

    Astrocytes are homeostatic cells of the central nervous system, which are critical for development and maintenance of synaptic transmission and hence of synaptically connected neuronal ensembles. Astrocytic densities are reduced in bipolar disorder, and therefore deficient astroglial function may contribute to overall disbalance in neurotransmission and to pathological evolution. Classical anti-bipolar drugs (lithium salts, valproic acid and carbamazepine) affect expression of astroglial genes and modify astroglial signalling and homeostatic cascades. Many effects of both antidepressant and anti-bipolar drugs are exerted through regulation of glutamate homeostasis and glutamatergic transmission, through K(+) buffering, through regulation of calcium-dependent phospholipase A2 (that controls metabolism of arachidonic acid) or through Ca(2+) homeostatic and signalling pathways. Sometimes anti-depressant and anti-bipolar drugs exert opposite effects, and some effects on gene expression in drug treated animals are opposite in neurones vs. astrocytes. Changes in the intracellular pH induced by anti-bipolar drugs affect uptake of myo-inositol and thereby signalling via inositoltrisphosphate (InsP3), this being in accord with one of the main theories of mechanism of action for these drugs. PMID:27015045

  16. Imunologia do transtorno bipolar Immunology of bipolar disorder

    OpenAIRE

    Izabela Guimarães Barbosa; Rodrigo Barreto Huguet; Fernando Silva Neves; Moisés Evandro Bauer; Antônio Lúcio Teixeira

    2009-01-01

    OBJETIVO: Pesquisas recentes têm implicado fatores imunes na patogênese de diversos transtornos neuropsiquiátricos. O objetivo do presente trabalho é revisar os trabalhos que investigaram a associação entre transtorno bipolar e alterações em parâmetros imunes. MÉTODOS: Artigos que incluíam as palavras-chave: "bipolar disorder", "mania", "immunology", "cytokines", "chemokines", "interleukins", "interferon" e "tumor necrosis factor" foram selecionados em uma revisão sistemática da literatura. A...

  17. Effect of Heavily Doped Boron on Bandgap Narrowing of Strained SiGe Layers

    Institute of Scientific and Technical Information of China (English)

    YAO Fei; XUE Chun-Lai; CHENG Bu-Wen; WANG Qi-Ming

    2007-01-01

    Taking into account the compensation effect of B to Ge in strained SiGe layers for the first time, the effect of heavily doped boron on the bandgap narrowing of strained SiGe layers is calculated, and the classical Jain-Roulston (J-R) model is modified. The results show that our modified J-R model well fits the experimental values. Based on the modified J-R model, the real bandgap narrowing distribution between the conduction and valence bands is further calculated, which has great influence on modelling the electrical characteristics of SiGe heterojunction bipolar transistors.

  18. SiGe HBT X-Band LNAs for Ultra-Low-Noise Cryogenic Receivers

    OpenAIRE

    Thirivikraman, Tushar K.; Yuan, Jiahui; Bardin, Joseph C.; Mani, Hamdi; Phillips, Stanley D.; Kuo, Wei-Min Lance; Cressler, John D.; Weinreb, Sander

    2008-01-01

    We report results on the cryogenic operation of two different monolithic X-band silicon-germanium (SiGe) heterojunction bipolar transistor low noise amplifiers (LNAs) implemented in a commercially-available 130 nm SiGe BiCMOS platform. These SiGe LNAs exhibit a dramatic reduction in noise temperature with cooling, yielding Teff of less than 21 K (0.3 dB noise figure) across X-band at a 15 K operating temperature. To the authors’ knowledge, these SiGe LNAs exhibit the lowest broadband noise...

  19. Direct simulation of ion beam induced stressing and amorphization of silicon

    OpenAIRE

    Beardmore, Keith M.; Gronbech-Jensen, Niels

    1999-01-01

    Using molecular dynamics (MD) simulation, we investigate the mechanical response of silicon to high dose ion-irradiation. We employ a realistic and efficient model to directly simulate ion beam induced amorphization. Structural properties of the amorphized sample are compared with experimental data and results of other simulation studies. We find the behavior of the irradiated material is related to the rate at which it can relax. Depending upon the ability to deform, we observe either the ge...

  20. Mathematical models of bipolar disorder

    Science.gov (United States)

    Daugherty, Darryl; Roque-Urrea, Tairi; Urrea-Roque, John; Troyer, Jessica; Wirkus, Stephen; Porter, Mason A.

    2009-07-01

    We use limit cycle oscillators to model bipolar II disorder, which is characterized by alternating hypomanic and depressive episodes and afflicts about 1% of the United States adult population. We consider two non-linear oscillator models of a single bipolar patient. In both frameworks, we begin with an untreated individual and examine the mathematical effects and resulting biological consequences of treatment. We also briefly consider the dynamics of interacting bipolar II individuals using weakly-coupled, weakly-damped harmonic oscillators. We discuss how the proposed models can be used as a framework for refined models that incorporate additional biological data. We conclude with a discussion of possible generalizations of our work, as there are several biologically-motivated extensions that can be readily incorporated into the series of models presented here.

  1. Design and optimization of Ge profiles for improved thermal stability of SiGe HBTs

    Institute of Scientific and Technical Information of China (English)

    Fu Qiang; Zhang Wanrong; Jin Dongyue; Ding Chunbao; Zhao Yanxiao; Zhang Yujie

    2013-01-01

    The impact of the three state-of-the-art germanium (Ge) profiles (box,trapezoid and triangular) across the base of SiGe heterojunction bipolar transistors (HBTs) under the condition of the same total amount of Ge on the temperature dependence of current gainβ and cut-off frequency fT,as well as the temperature profile,are investigated.It can be found that although theβ of HBT with a box Ge profile is larger than that of the others,it decreases the fastest as the temperature increases,while theβ of HBT with a triangular Ge profile is smaller than that of the others,but decreases the slowest as the temperature increases.On the other hand,the fT of HBT with a trapezoid Ge profile is larger than that of the others,but decreases the fastest as the temperature increases,and the fT of HBT with a box Ge profile is smaller than that of the others,but decreases the slowest as temperature increases.Furthermore,the peak and surface temperature difference between the emitter fingers of the HBT with a triangular Ge profile is higher than that of the others.Based on these results,a novel segmented step box Ge profile is proposed,which has modestβ and fT,and trades off the temperature sensitivity of current gain and cut-off frequency,and the temperature profile of the device.

  2. 193 nm Excimer laser processing of Si/Ge/Si(100) micropatterns

    Science.gov (United States)

    Gontad, F.; Conde, J. C.; Chiussi, S.; Serra, C.; González, P.

    2016-01-01

    193 nm Excimer laser assisted growth and crystallization of amorphous Si/Ge bilayer patterns with circular structures of 3 μm diameter and around 25 nm total thickness, is presented. Amorphous patterns were grown by Laser induced Chemical Vapor Deposition, using nanostencils as shadow masks and then irradiated with the same laser to induce structural and compositional modifications for producing crystalline SiGe alloys through fast melting/solidification cycles. Compositional and structural analyses demonstrated that pulses of 240 mJ/cm2 lead to graded SiGe alloys with Si rich discs of 2 μm diameter on top, a buried Ge layer, and Ge rich SiGe rings surrounding each feature, as predicted by previous numerical simulation.

  3. Anomalous activation of shallow B+ implants in Ge

    DEFF Research Database (Denmark)

    Yates, B.R.; Darby, B.L.; Rudawski, N.G.;

    2011-01-01

    The electrical activation of B+ implantation at 2 keV to doses of 5.0×1013-5.0×1015 cm-2 in crystalline and pre-amorphized Ge following annealing at 400 °C for 1.0 h was studied using micro Hall effect measurements. Preamorphization improved activation for all samples with the samples implanted t...

  4. Social support and bipolar disorder

    OpenAIRE

    Paula Mendonça Studart; Severino Bezerra Filho; Ana Beatriz Didier Studart; Amanda Galvão-de Almeida; Ângela Miranda-Scippa

    2015-01-01

    Background Bipolar disorder is a chronic condition that affects the functioning of its carriers in many different ways, even when treated properly. Therefore, it’s also important to identify the psychosocial aspects that could contribute to an improvement of this population’s quality of life.Objective Carry out a literature review on the role of social support in cases of bipolar disorder.Method A research on the following online databases PubMed, Lilacs and SciELO was conducted by using the ...

  5. Bipolar lead acid battery development

    Science.gov (United States)

    Eskra, Michael; Vidas, Robin; Miles, Ronald; Halpert, Gerald; Attia, Alan; Perrone, David

    1991-01-01

    A modular bipolar battery configuration is under development at Johnson Control, Inc. (JCI) and the Jet Propulsion Laboratory (JPL). The battery design, incorporating proven lead acid electrochemistry, yields a rechargeable, high-power source that is light weight and compact. This configuration offers advantages in power capability, weight, and volume over conventional monopolar batteries and other battery chemistries. The lead acid bipolar battery operates in a sealed, maintenance-free mode allowing for maximum application flexibility. It is ideal for high-voltage and high-power applications.

  6. Bipolar dislocation of the clavicle

    Directory of Open Access Journals (Sweden)

    Wei Jiang

    2012-01-01

    Full Text Available Bipolar dislocation of the clavicle at acromioclavicular and sternoclavicular joint is an uncommon traumatic injury. The conservative treatments adopted in the past is associated with redislocation dysfunction and deformity. A 41 years old lady with bipolar dislocation of right shoulder is treated surgically by open reduction and internal fixation by oblique T-plate at sternoclavicular joint and Kirschner wire stabilization at acromioclavicular joint. The patient showed satisfactory recovery with full range of motion of the right shoulder and normal muscular strength. The case reported in view of rarity and at 2 years followup.

  7. Bipolar dislocation of the clavicle.

    Science.gov (United States)

    Jiang, Wei; Gao, Shu-Guang; Li, Yu-Sheng; Lei, Guang-Hua

    2012-11-01

    Bipolar dislocation of the clavicle at acromioclavicular and sternoclavicular joint is an uncommon traumatic injury. The conservative treatments adopted in the past is associated with redislocation dysfunction and deformity. A 41 years old lady with bipolar dislocation of right shoulder is treated surgically by open reduction and internal fixation by oblique T-plate at sternoclavicular joint and Kirschner wire stabilization at acromioclavicular joint. The patient showed satisfactory recovery with full range of motion of the right shoulder and normal muscular strength. The case reported in view of rarity and at 2 years followup. PMID:23325981

  8. Refractory bipolar disorder and neuroprogression.

    Science.gov (United States)

    da Costa, Sabrina C; Passos, Ives C; Lowri, Caroline; Soares, Jair C; Kapczinski, Flavio

    2016-10-01

    Immune activation and failure of physiologic compensatory mechanisms over time have been implicated in the pathophysiology of illness progression in bipolar disorder. Recent evidence suggests that such changes are important contributors to neuroprogression and may mediate the cross-sensitization of episode recurrence, trauma exposure and substance use. The present review aims to discuss the potential factors related to bipolar disorder refractoriness and neuroprogression. In addition, we will discuss the possible impacts of early therapeutic interventions as well as the alternative approaches in late stages of the disorder. PMID:26368941

  9. Amorphous Semiconductor Nanowires Created by Site-Specific Heteroatom Substitution with Significantly Enhanced Photoelectrochemical Performance.

    Science.gov (United States)

    He, Ting; Zu, Lianhai; Zhang, Yan; Mao, Chengliang; Xu, Xiaoxiang; Yang, Jinhu; Yang, Shihe

    2016-08-23

    Semiconductor nanowires that have been extensively studied are typically in a crystalline phase. Much less studied are amorphous semiconductor nanowires due to the difficulty for their synthesis, despite a set of characteristics desirable for photoelectric devices, such as higher surface area, higher surface activity, and higher light harvesting. In this work of combined experiment and computation, taking Zn2GeO4 (ZGO) as an example, we propose a site-specific heteroatom substitution strategy through a solution-phase ions-alternative-deposition route to prepare amorphous/crystalline Si-incorporated ZGO nanowires with tunable band structures. The substitution of Si atoms for the Zn or Ge atoms distorts the bonding network to a different extent, leading to the formation of amorphous Zn1.7Si0.3GeO4 (ZSGO) or crystalline Zn2(GeO4)0.88(SiO4)0.12 (ZGSO) nanowires, respectively, with different bandgaps. The amorphous ZSGO nanowire arrays exhibit significantly enhanced performance in photoelectrochemical water splitting, such as higher and more stable photocurrent, and faster photoresponse and recovery, relative to crystalline ZGSO and ZGO nanowires in this work, as well as ZGO photocatalysts reported previously. The remarkable performance highlights the advantages of the ZSGO amorphous nanowires for photoelectric devices, such as higher light harvesting capability, faster charge separation, lower charge recombination, and higher surface catalytic activity. PMID:27494205

  10. Pseudomorphic GeSn/Ge (001) heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Tonkikh, A. A., E-mail: tonkikh@mpi-halle.de [Max Planck Institute of Microstructure Physics (Germany); Talalaev, V. G. [Martin Luther University Halle-Wittenberg, ZIK SiLi-nano (Germany); Werner, P. [Max Planck Institute of Microstructure Physics (Germany)

    2013-11-15

    The synthesis of pseudomorphic GeSn heterostructures on a Ge (001) substrate by molecular-beam epitaxy is described. Investigations by transmission electron microscopy show that the GeSn layers are defect free and possess cubic diamondlike structure. Photoluminescence spectroscopy reveals interband radiative recombination in the GeSn quantum wells, which is identified as indirect transitions between the subbands of heavy electrons and heavy holes. On the basis of experimental data and modeling of the band structure of pseudomorphic GeSn compounds, the lower boundary of the bowing parameter for the indirect band gap is estimated as b{sub L} {>=} 1.47 eV.

  11. Direct synthesis of highly textured Ge on flexible polyimide films by metal-induced crystallization

    OpenAIRE

    Oya, N; Toko, K.; Saitoh, N.; Yoshizawa, N.; Suemasu, T.

    2014-01-01

    The highly (111)-textured Ge thin film (50-nm thickness) is demonstrated on a flexible polyimide film via the low-temperature crystallization (325 °C) of amorphous Ge using Al as a catalyst. Covering the polyimide with insulators significantly improved the crystal quality of the resulting Ge layer. In particular, SiN covering led to 97% (111)-oriented Ge with grains 200 μm in size, two orders larger than the grain size of polycrystalline Ge directly formed on the polyimide film. This achievem...

  12. Growth Mechanism and Surface Structure of Ge Nanocrystals Prepared by Thermal Annealing of Cosputtered GeSiO Ternary Precursor

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2014-01-01

    Full Text Available Ge nanocrystals (Ge-ncs embedded in a SiO2 superlattice structure were prepared by magnetron cosputtering and postdeposition annealing. The formation of spherical nanocrystals was confirmed by transmission electron microscopy and their growth process was studied by a combination of spectroscopic techniques. The crystallinity volume fraction of Ge component was found to increase with crystallite size, but its overall low values indicated a coexistence of crystalline and noncrystalline phases. A reduction of Ge-O species was observed in the superlattice during thermal annealing, accompanied by a transition from oxygen-deficient silicon oxide to silicon dioxide. A growth mechanism involving phase separation of Ge suboxides (GeOx was then proposed to explain these findings and supplement the existing growth models for Ge-ncs in SiO2 films. Further analysis of the bonding structure of Ge atoms suggested that Ge-ncs are likely to have a core-shell structure with an amorphous-like surface layer, which is composed of GeSiO ternary complex. The surface layer thickness was extracted to be a few angstroms and equivalent to several atomic layer thicknesses.

  13. Sleep Disturbances in Bipolar Disorder

    Directory of Open Access Journals (Sweden)

    Cátia Alves Moreira

    2015-11-01

    Full Text Available Background: Bipolar disorder, characterized by episodes of mania, hypomania and depression is associated with sleep disturbances and circadian rhythm disruption. These changes have significant impact on quality of life and in the disease prognosis. Aims: Review of the main sleep disturbances observed in the bipolar disorder, their clinical impact and the hypothetical pathophysiological mechanisms involved. Methods: We conducted a non-systematic review of the literature in English through research in PubMed with the keywords “sleep disturbance”, “bipolar disorder”, “polysomnography”. Results and Conclusions: Complaints about sleep pattern changes may occur during any phase of the disease. These in clude frequent night-time awakenings, poor sleep quality, reduction of the total sleeping time and decreased latency and increased density of REM sleep. The treatment of the sleep disturbances observed in bipolar disorder should be considered a priority, since it prevents symptoms recurrence and facilitate the socio-professional integration, thus providing greater success in patient’s rehabilitation and quality of life.

  14. SUTURELESS THYROIDECTOMY WITH BIPOLAR DIATHERMY

    Directory of Open Access Journals (Sweden)

    Ravi Kumar

    2016-05-01

    Full Text Available The thyroid gland is one of the most vascular organs in the body and surgical resection mandates meticulous surgical technique and haemostasis. The rate of complications of thyroid surgeries were very high earlier but with the advent of ligasure, harmonic scalpel and bipolar surgical diathermy complications have reduced. In this study, we have used bipolar surgical diathermy. MATERIALS 116 patients with thyroid swelling attending surgical OPD in Vydehi Institute of Medical Sciences and Research Centre during the period of 2011-2015 were included in the study. Proper preoperative workup was done and sutureless thyroidectomy surgeries were done using bipolar surgical diathermy. Patients were reviewed for any complications following thyroidectomy like haemorrhage, hypocalcaemia and recurrent laryngeal nerve palsy. RESULTS Out of 116 patients who underwent sutureless thyroidectomy none of them had any primary, secondary or reactionary haemorrhage, one patient who underwent total thyroidectomy for follicular carcinoma had transient hypocalcaemia. CONCLUSION Sutureless thyroidectomy is a very good surgical practice with bipolar surgical diathermy and it permits low postoperative complications and cost effectiveness.

  15. Corrosion resistant metallic bipolar plate

    Science.gov (United States)

    Brady, Michael P.; Schneibel, Joachim H.; Pint, Bruce A.; Maziasz, Philip J.

    2007-05-01

    A corrosion resistant, electrically conductive component such as a bipolar plate for a PEM fuel cell includes 20 55% Cr, balance base metal such as Ni, Fe, or Co, the component having thereon a substantially external, continuous layer of chromium nitride.

  16. [Cognitive deficits in bipolar disorder].

    Science.gov (United States)

    Sachs, Gabriele; Schaffer, Markus; Winklbaur, Bernadette

    2007-01-01

    Bipolar disorders are often associated with cognitive deficits which have an influence on social functioning and the course of the illness. These deficits have an impact on occupational ability and social integration. To date, specific cognitive domains have been found which characterize bipolar affective disorders. However, there is evidence of stable and lasting cognitive impairment in all phases of the disorder, including the remission phase, in the following domains: sustained attention, memory and executive functions (e.g. cognitive flexibility and problem solving). Although their cognitive deficits are comparable the deficits in patients with schizophrenia are more severe than those with bipolar disorder. Recent brain imaging findings indicate structural and functional abnormalities in the cortical and limbic networks of the brain in patients with bipolar disorder compared to healthy controls. Mood stabilizer and atypical antipsychotics may reduce cognitive deficits in certain domains (e.g. executive functions and word fluency) and may have a positive effect on quality of life and social functioning. PMID:17640495

  17. Social support and bipolar disorder

    Directory of Open Access Journals (Sweden)

    Paula Mendonça Studart

    2015-08-01

    Full Text Available Background Bipolar disorder is a chronic condition that affects the functioning of its carriers in many different ways, even when treated properly. Therefore, it’s also important to identify the psychosocial aspects that could contribute to an improvement of this population’s quality of life.Objective Carry out a literature review on the role of social support in cases of bipolar disorder.Method A research on the following online databases PubMed, Lilacs and SciELO was conducted by using the keywords “social support” or “social networks” and “mood disorders” or “bipolar disorder” or “affective disorder,” with no defined timeline.Results Only 13 studies concerning the topic of social support and BD were found in the search for related articles. Generally speaking, the results show low rates of social support for BD patients.Discussion Despite the growing interest in the overall functioning of patients with bipolar disorder, studies on social support are still rare. Besides, the existing studies on the subject use different methodologies, making it difficult to establish data comparisons.

  18. Plasmon-assisted photoresponse in Ge-coated bowtie nanojunctions

    CERN Document Server

    Evans, Kenneth M; Natelson, Douglas

    2016-01-01

    We demonstrate plasmon-enhanced photoconduction in Au bowtie nanojunctions containing nanogaps overlaid with an amorphous Ge film. The role of plasmons in the production of nanogap photocurrent is verified by studying the unusual polarization dependence of the photoresponse. With increasing Ge thickness, the nanogap polarization of the photoresponse rotates 90 degrees, indicating a change in the dominant relevant plasmon mode, from the resonant transverse plasmon at low thicknesses to the nonresonant "lightning rod" mode at higher thicknesses. To understand the plasmon response in the presence of the Ge overlayer and whether the Ge degrades the Au plasmonic properties, we investigate the photothermal response (from the temperature-dependent Au resistivity) in no-gap nanowire structures, as a function of Ge film thickness and nanowire geometry. The film thickness and geometry dependence are modeled using a cross-sectional, finite element simulation. The no-gap structures and the modeling confirm that the strik...

  19. Analytical modeling and numerical simulations of the thermal behavior of bipolar transistors

    OpenAIRE

    Marano, Ilaria

    2008-01-01

    The thermal behavior of various bipolar transistor categories, namely, trench-isolated (1) SOI BJTs, (2) BJTs fabricated on silicon substrates, and (3) SiGe HBTs, is thorougly analyzed. Detailed 3-D numerical simulations are employed to provide a deep understanding of the thermal process in all the structures. Based on the numerical analysis, novel highly-effective analytical thermal models are conceived and developed for a fully predictive detection of the temperature field corresponding to ...

  20. Amorphous silicon based particle detectors

    OpenAIRE

    Wyrsch, N; Franco, A; Riesen, Y.; Despeisse, M; S. Dunand; Powolny, F; Jarron, P.; Ballif, C.

    2012-01-01

    Radiation hard monolithic particle sensors can be fabricated by a vertical integration of amorphous silicon particle sensors on top of CMOS readout chip. Two types of such particle sensors are presented here using either thick diodes or microchannel plates. The first type based on amorphous silicon diodes exhibits high spatial resolution due to the short lateral carrier collection. Combination of an amorphous silicon thick diode with microstrip detector geometries permits to achieve micromete...

  1. Responsabilidade penal no transtorno bipolar Penal responsibility in bipolar disorder

    Directory of Open Access Journals (Sweden)

    Alexandre Martins Valença

    2010-01-01

    Full Text Available Os autores relatam o caso de uma mulher que cometeu delito de assalto e foi avaliada em perícia psiquiátrica para análise da responsabilidade penal. Conclui-se que ela apresentava doença mental, na forma de transtorno bipolar, daí ser inimputável. A avaliação da responsabilidade penal é de extrema importância, para que se possam aplicar medidas de segurança ou sanções penais e correcionais adequadas a cada caso.The authors report a case of a woman who committed the crime of assault and was evaluated in penal imputability exam to assess criminal responsibility. It was concluded that she had a mental illness, bipolar disorder, being inimputable. The evaluation of penal responsibility is extremely important, in order to apply adequate involuntary commitment or correctional and penal sanctions to each case.

  2. Circadian rhythms in the neuorbiology of bipolar of bipolar disorder

    OpenAIRE

    Timothy, Joseph

    2015-01-01

    Daily rhythms of physiology and behaviour in mammals are orchestrated by a hierarchical network of cellular oscillators. The master pacemaker that defines local and systemic timing across the brain and body are the suprachiasmatic nuclei of the hypothalamus (SCN). Disruption to the timing of sleep and daily behavioural activity can manifest in a range of pathologies including neuropsychiatric disorders. Bipolar disorder (BPD) is once such neurological condition that exhibits profound associat...

  3. Fabrication and ferromagnetism of Si-SiGe/MnGe core-shell nanopillars

    Science.gov (United States)

    Wang, Liming; Liu, Tao; Wang, Shuguang; Zhong, Zhenyang; Jia, Quanjie; Jiang, Zuimin

    2016-10-01

    Si-Si0.5Ge0.5/Mn0.08Ge0.92 core-shell nanopillar samples were fabricated on ordered Si nanopillar patterned substrates by molecular beam epitaxy at low temperatures. The magnetic properties of the samples are found to depend heavily on the growth temperature of the MnGe layer. The sample grown at a moderate temperature of 300 °C has the highest Curie temperature of 240 K as well as the strongest ferromagnetic signals. On the basis of the microstructural results, the ferromagnetic properties of the samples are believed to come from the intrinsic Mn-doped amorphous or crystalline Ge ferromagnetic phase rather than any intermetallic ferromagnetic compounds of Mn and Ge. After being annealed at a temperature of 500 °C, all the samples exhibit the same Curie temperature of 220 K, which is in sharp contrast to the different Curie temperature for the as-grown samples, and the ferromagnetism for the annealed samples comes from Mn5GeSi2 compounds which are formed during the annealing.

  4. The International Society for Bipolar Disorders (ISBD) Task Force Report on Antidepressant Use in Bipolar Disorders

    NARCIS (Netherlands)

    Pacchiarotti, Isabella; Bond, David J.; Baldessarini, Ross J.; Nolen, Willem A.; Grunze, Heinz; Licht, Rasmus W.; Post, Robert M.; Berk, Michael; Goodwin, Guy M.; Sachs, Gary S.; Tondo, Leonardo; Findling, Robert L.; Youngstrom, Eric A.; Tohen, Mauricio; Undurraga, Juan; Gonzalez-Pinto, Ana; Goldberg, Joseph F.; Yildiz, Aysegul; Altshuler, Lori L.; Calabrese, Joseph R.; Mitchell, Philip B.; Thase, Michael E.; Koukopoulos, Athanasios; Colom, Francesc; Frye, Mark A.; Malhi, Gin S.; Fountoulakis, Konstantinos N.; Vazquez, Gustavo; Perlis, Roy H.; Ketter, Terence A.; Cassidy, Frederick; Akiskal, Hagop; Azorin, Jean-Michel; Valenti, Marc; Mazzei, Diego Hidalgo; Lafer, Beny; Kato, Tadafumi; Mazzarini, Lorenzo; Martinez-Aran, Anabel; Parker, Gordon; Souery, Daniel; Ozerdem, Aysegul; McElroy, Susan L.; Girardi, Paolo; Bauer, Michael; Yatham, Lakshmi N.; Zarate, Carlos A.; Nierenberg, Andrew A.; Birmaher, Boris; Kanba, Shigenobu; El-Mallakh, Rif S.; Serretti, Alessandro; Rihmer, Zoltan; Young, Allan H.; Kotzalidis, Georgios D.; MacQueen, Glenda M.; Bowden, Charles L.; Ghaemi, S. Nassir; Lopez-Jaramillo, Carlos; Rybakowski, Janusz; Ha, Kyooseob; Perugi, Giulio; Kasper, Siegfried; Amsterdam, Jay D.; Hirschfeld, Robert M.; Kapczinski, Flavio; Vieta, Eduard

    2013-01-01

    Objective: The risk-benefit profile of antidepressant medications in bipolar disorder is controversial. When conclusive evidence is lacking, expert consensus can guide treatment decisions. The International Society for Bipolar Disorders (ISBD) convened a task force to seek consensus recommendations

  5. Internet use by patients with bipolar disorder

    DEFF Research Database (Denmark)

    Bauer, Rita; Conell, Jörn; Glenn, Tasha;

    2016-01-01

    There is considerable international interest in online education of patients with bipolar disorder, yet little understanding of how patients use the Internet and other sources to seek information. 1171 patients with a diagnosis of bipolar disorder in 17 countries completed a paper-based, anonymous...... on bipolar disorder or 63% of the total sample. More years of education in relation to the country mean, and feeling very confident about managing life decreased the odds of seeking information on bipolar disorder online, while having attended support groups increased the odds. Patients who looked online...... for information on bipolar disorder consulted medical professionals plus a mean of 2.3 other information sources such as books, physician handouts, and others with bipolar disorder. Patients not using the Internet consulted medical professionals plus a mean of 1.6 other information sources. The percentage...

  6. Bipolar disorder: staging and neuroprogression

    OpenAIRE

    Rodrigues, Aline André; Rosa, Adriana R.; Kunz, Maurício; Ascoli, Bruna; Kapczinski, Flávio

    2014-01-01

    In bipolar disorder illness progression has been associated with a higher number of mood episodes and hospitalizations, poorer response to treatment, and more severe cognitive and functional impairment. This supports the notion of the use of staging models in this illness. The value of staging models has long been recognized in many medical and malignant conditions. Staging models rely on the fact that different interventions may suit different stages of the disorder, and that better outcomes...

  7. Neurocognitive function in bipolar disorder: a comparison between bipolar I and II disorder and matched controls

    OpenAIRE

    Pålsson, Erik; Figueras, Clara; Johansson, Anette GM; Ekman, Carl-Johan; Hultman, Björn; Östlind, Josefin; Landén, Mikael

    2013-01-01

    Background Cognitive deficits have been documented in patients with bipolar disorder. Further, it has been suggested that the degree and type of cognitive impairment differ between bipolar I and bipolar II disorder, but data is conflicting and remains inconclusive. This study aimed to clarify the suggested differences in cognitive impairment between patients with bipolar I and II disorder in a relatively large, clinically stable sample while controlling for potential confounders. Methods 67 p...

  8. Tuning electronic properties of graphene heterostructures by amorphous-to-crystalline phase transitions

    Science.gov (United States)

    Kulju, S.; Akola, J.; Prendergast, D.; Jones, R. O.

    2016-05-01

    The remarkable ability of phase change materials (PCM) to switch between amorphous and crystalline states on a nanosecond time scale could provide new opportunities for graphene engineering. We have used density functional calculations to investigate the structures and electronic properties of heterostructures of thin amorphous and crystalline films of the PCM GeTe (16 Å thick) and Ge2Sb2Te5 (20 Å) between graphene layers. The interaction between graphene and PCM is very weak, charge transfer is negligible, and the structures of the chalcogenide films differ little from those of bulk phases. A crystalline GeTe (111) layer induces a band gap opening of 80 meV at the Dirac point. This effect is absent for the amorphous film, but the Fermi energy shifts down along the Dirac cone by -60 meV. Ge2Sb2Te5 shows similar features, although inherent disorder in the crystalline rocksalt structure reduces the contrast in band structure from that in the amorphous structure. These features originate in charge polarization within the crystalline films, which show electromechanical response (piezoelectricity) upon compression, and show that the electronic properties of graphene structures can be tuned by inducing ultrafast structural transitions within the chalcogenide layers. Graphene can also be used to manipulate the structural state of the PCM layer and its electronic and optical properties.

  9. Metabolic syndrome in bipolar disorders

    Directory of Open Access Journals (Sweden)

    Sandeep Grover

    2012-01-01

    Full Text Available To review the data with respect to prevalence and risk factors of metabolic syndrome (MetS in bipolar disorder patients. Electronic searches were done in PUBMED, Google Scholar and Science direct. From 2004 to June 2011, 34 articles were found which reported on the prevalence of MetS. The sample size of these studies varied from 15 to 822 patients, and the rates of MetS vary widely from 16.7% to 67% across different studies. None of the sociodemographic variable has emerged as a consistent risk factor for MetS. Among the clinical variables longer duration of illness, bipolar disorder- I, with greater number of lifetime depressive and manic episodes, and with more severe and difficult-to-treat index affective episode, with depression at onset and during acute episodes, lower in severity of mania during the index episode, later age of onset at first manic episode, later age at first treatment for the first treatment for both phases, less healthy diet as rated by patients themselves, absence of physical activity and family history of diabetes mellitus have been reported as clinical risk factors of MetS. Data suggests that metabolic syndrome is fairly prevalent in bipolar disorder patients.

  10. Biological rhythm disturbance in remitted bipolar patients

    OpenAIRE

    Rosa, Adriane R; Comes, Mercè; Torrent, Carla; Solè, Brisa; Reinares, Maria; Pachiarotti, Isabella; Salamero, Manel; Kapczinski, Flávio; Colom, Francesc; Vieta, Eduard

    2013-01-01

    Background Biological rhythm disturbance is common in bipolar patients and seems to affect the course and prognosis of the illness negatively. The main aim of the current study was to assess biological rhythms in remitted bipolar patients. We also assessed whether there was an association between clinical variables or functioning and biological rhythms in remitted bipolar participants. Methods The Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN) was used to assess biologi...

  11. Bipolar Experiences and Self-Identity

    OpenAIRE

    Bedford, Rosie

    2012-01-01

    Background: Bipolar II disorder has a prevalence rate of approximately 0.4% in adults and 1.5% in adolescents, with the onset typically around 18 years old (Merikangas & Lamers, 2012). As the age of onset is during adolescent years the impact on identity is of special interest. Although the profound impact bipolar has on an individual’s sense of self has surfaced as a predominant theme in the bipolar literature, there remains a dearth of research directly addressing this impact. ...

  12. Major Ups and Downs: Bipolar Disorder Brings Extreme Mood Swings

    Science.gov (United States)

    ... our exit disclaimer . Subscribe Major Ups and Downs Bipolar Disorder Brings Extreme Mood Swings Most people feel happy ... Strike Out Stroke Wise Choices Links Dealing with Bipolar Disorder If you have bipolar disorder, get treatment and ...

  13. Course of Subthreshold Bipolar Disorder in Youth: Diagnostic Progression from Bipolar Disorder Not Otherwise Specified

    Science.gov (United States)

    Axelson, David A.; Birmaher, Boris; Strober, Michael A.; Goldstein, Benjamin I.; Ha, Wonho; Gill, Mary Kay; Goldstein, Tina R.; Yen, Shirley; Hower, Heather; Hunt, Jeffrey I.; Liao, Fangzi; Iyengar, Satish; Dickstein, Daniel; Kim, Eunice; Ryan, Neal D.; Frankel, Erica; Keller, Martin B.

    2011-01-01

    Objective: To determine the rate of diagnostic conversion from an operationalized diagnosis of bipolar disorder not otherwise specified (BP-NOS) to bipolar I disorder (BP-I) or bipolar II disorder (BP-II) in youth over prospective follow-up and to identify factors associated with conversion. Method: Subjects were 140 children and adolescents…

  14. ????????????-???????????? ?????? ? ????????????? ????????? ???????? ??????? Ge-Si

    OpenAIRE

    ????????, ?. ?.; ???????????, ?. ?.; ???, ?. ?.; ?????????, ?. ?.

    2003-01-01

    ?????????? ????????????-???????????? ?????? ? ????????????? ????????? (??) ???????? ??????? GexSi1-x (? = 0.01 - 0.03) p-???? ??????????? ? ?????????????? ????????? (4,2 ... 300 K). ????????????? ????? ?????????? ?? ?????-??? ?? ?????????????????? ??. ??????????? ?????????? ??????? ????????? ??????? ??? ?????????? ??. ???????? ?????????? ??????????? ?'???-??????? ?? ??????????????? ? ?? Ge-Si ??????? ???????? ?????-?????????? ?? ???????? ???????????. ?????????? ?????????? ??????????? ???...

  15. Bipolar Disorder and Obsessive Compulsive Disorder Comorbidity

    Directory of Open Access Journals (Sweden)

    Necla Keskin

    2014-08-01

    Full Text Available The comorbidity of bipolar disorder and anxiety disorders is a well known concept. Obsessive-compulsive disorder is the most commonly seen comorbid anxiety disorder in bipolar patients. Some genetic variants, neurotransmitters especially serotonergic systems and second-messenger systems are thought to be responsible for its etiology. Bipolar disorder alters the clinical aspects of obsessive compulsive disorder and is associated with poorer outcome. The determination of comorbidity between bipolar disorder and obsessive compulsive disorder is quite important for appropriate clinical management and treatment. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(4.000: 429-437

  16. [Oxidative stress in bipolar affective disorder].

    Science.gov (United States)

    Reininghaus, E Z; Zelzer, S; Reininghaus, B; Lackner, N; Birner, A; Bengesser, S A; Fellendorf, F T; Kapfhammer, H-P; Mangge, H

    2014-09-01

    The results of mortality studies have indicated that medical conditions, such as cardiovascular disease, obesity and diabetes are the most important causes of mortality among patients with bipolar disorder. The reasons for the increased incidence and mortality are not fully understood. Oxidative stress and an inadequate antioxidative system might be one missing link and could also help to further elucidate the pathophysiological basis of bipolar disorder. This article provides a comprehensive review of oxidative stress in general and about the existing data for bipolar disorder. In addition information is given about possible therapeutic strategies to reduce oxidative stress and the use in bipolar disorder. PMID:24441847

  17. SiGe HBT BiCMOS technology for millimeter-wave applications

    Science.gov (United States)

    Joseph, Alvin; Dahlstrom, Mattias; Liu, Qizhi; Orner, Bradley; Liu, Xuefeng; Sheridan, David; Rassel, Robert; Dunn, Jim; Ahlgren, David

    2006-03-01

    We present the advances in Silicon Germanium Heterojunction Bipolar Transistor (SiGe HBT) and BiCMOS technology capabilities to address the emerging millimetre-wave (mmWave) applications. SiGe HBTs with f MAX performance reaching 350 GHz that are integrated with advanced CMOS and high-frequency passives is envisioned to allow better integration capability for mmWave applications. This capability of SiGe HBT BiCMOS technology is discussed relative to an InP HBT technology.

  18. Laser ablation and growth of Si and Ge

    Energy Technology Data Exchange (ETDEWEB)

    Yap, Seong Shan, E-mail: seong.yap@ntnu.no [Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Siew, Wee Ong; Nee, Chen Hon [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Reenaas, Turid Worren [Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Tou, Teck Yong [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)

    2012-02-01

    In this work, we investigated the laser ablation and deposition of Si and Ge at room temperature in vacuum by employing nanosecond lasers of 248 nm, 355 nm, 532 nm and 1064 nm. Time-integrated optical emission spectra were obtained for neutrals and ionized Ge and Si species in the plasma at laser fluences from 0.5 to 11 J/cm{sup 2}. The deposited films were characterized by using Raman spectroscopy, scanning electron microscopy and atomic force microscopy. Amorphous Si and Ge films, micron-sized crystalline droplets and nano-sized particles were deposited. The results suggested that ionized species in the plasma promote the process of subsurface implantation for both Si and Ge films while large droplets were produced from the superheated and melted layer of the target. The dependence of the properties of the materials on laser wavelength and fluence were discussed.

  19. Formation of Ge{sup 0} and GeO{sub x} nanoclusters in Ge{sup +}-implanted SiO{sub 2}/Si thin-film heterostructures under rapid thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Zatsepin, A.F., E-mail: a.f.zatsepin@urfu.ru [Institute of Physics and Technology, Ural Federal University, Mira Str. 19, 620002 Yekaterinburg (Russian Federation); Zatsepin, D.A. [Institute of Physics and Technology, Ural Federal University, Mira Str. 19, 620002 Yekaterinburg (Russian Federation); Institute of Metal Physics, Russian Academy of Sciences – Ural Division, S. Kovalevskoi Str. 18, 620990 Yekaterinburg (Russian Federation); Institute of Physics, Polish Academy of Science, 02-668 Warsaw (Poland); Zhidkov, I.S. [Institute of Physics and Technology, Ural Federal University, Mira Str. 19, 620002 Yekaterinburg (Russian Federation); Kurmaev, E.Z. [Institute of Physics and Technology, Ural Federal University, Mira Str. 19, 620002 Yekaterinburg (Russian Federation); Institute of Metal Physics, Russian Academy of Sciences – Ural Division, S. Kovalevskoi Str. 18, 620990 Yekaterinburg (Russian Federation); Fitting, H.-J. [Institute of Physics, University of Rostock, D-18051 Rostock (Germany); Schmidt, B. [Institute of Ion Beam Physics, Research Center Dresden-Rossendorf, POB 510119, 01314 Dresden (Germany); Mikhailovich, A.P. [Institute of Physics and Technology, Ural Federal University, Mira Str. 19, 620002 Yekaterinburg (Russian Federation); Lawniczak-Jablonska, K. [Institute of Physics, Polish Academy of Science, 02-668 Warsaw (Poland)

    2015-09-15

    Highlights: • Results of XPS for valence and core levels of Ge implanted SiO{sub 2} films are presented. • Chemical-state transformation of the host-matrix composition and Ge ions is performed. • The rapid thermal annealing strongly affects the oxidation states of Ge-atoms. • The formation of Ge{sup 0} and GeO{sub x} clusters within subsurface layer is observed. - Abstract: The results of X-ray photoelectron spectra (XPS valence band and core levels) measurements for Ge{sup +} implanted SiO{sub 2}/Si heterostructures are presented. These heterostructures have a 30 nm thick Ge{sup +} ion implanted amorphous SiO{sub 2} layer on p-type Si. The chemical-state transformation of the host-matrix composition after Ge{sup +} ion implantation and rapid thermal annealing (RTA) are discussed. The XPS-analysis performed allows to conclude the formation of Ge{sup 0} and GeO{sub x} clusters within the samples under study. It was established, that the annealing time strongly affects the degree of oxidation states of Ge-atoms.

  20. Morphological analysis of GeTe in inline phase change switches

    International Nuclear Information System (INIS)

    Crystallization and amorphization phenomena in indirectly heated phase change material-based devices were investigated. Scanning transmission electron microscopy was utilized to explore GeTe phase transition processes in the context of the unique inline phase change switch (IPCS) architecture. A monolithically integrated thin film heating element successfully converted GeTe to ON and OFF states. Device cycling prompted the formation of an active area which sustains the majority of structural changes during pulsing. A transition region on both sides of the active area consisting of polycrystalline GeTe and small nuclei (<15 nm) in an amorphous matrix was also observed. The switching mechanism, determined by variations in pulsing parameters, was shown to be predominantly growth-driven. A preliminary model for crystallization and amorphization in IPCS devices is presented

  1. Morphological analysis of GeTe in inline phase change switches

    Science.gov (United States)

    King, Matthew R.; El-Hinnawy, Nabil; Salmon, Mike; Gu, Jitty; Wagner, Brian P.; Jones, Evan B.; Borodulin, Pavel; Howell, Robert S.; Nichols, Doyle T.; Young, Robert M.

    2015-09-01

    Crystallization and amorphization phenomena in indirectly heated phase change material-based devices were investigated. Scanning transmission electron microscopy was utilized to explore GeTe phase transition processes in the context of the unique inline phase change switch (IPCS) architecture. A monolithically integrated thin film heating element successfully converted GeTe to ON and OFF states. Device cycling prompted the formation of an active area which sustains the majority of structural changes during pulsing. A transition region on both sides of the active area consisting of polycrystalline GeTe and small nuclei (<15 nm) in an amorphous matrix was also observed. The switching mechanism, determined by variations in pulsing parameters, was shown to be predominantly growth-driven. A preliminary model for crystallization and amorphization in IPCS devices is presented.

  2. Amorphous silicon based large format uncooled FPA microbolometer technology

    Science.gov (United States)

    Schimert, T.; Brady, J.; Fagan, T.; Taylor, M.; McCardel, W.; Gooch, R.; Ajmera, S.; Hanson, C.; Syllaios, A. J.

    2008-04-01

    This paper presents recent developments in next generation microbolometer Focal Plane Array (FPA) technology at L-3 Communications Infrared Products (L-3 CIP). Infrared detector technology at L-3 CIP is based on hydrogenated amorphous silicon (a-Si:H) and amorphous silicon germanium(a-SiGe:H). Large format high performance, fast, and compact IR FPAs are enabled by a low thermal mass pixel design; favorable material properties; an advanced ROIC design; and wafer level packaging. Currently at L-3 CIP, 17 micron pixel FPA array technology including 320x240, 640 x 480 and 1024 x768 arrays is under development. Applications of these FPAs range from low power microsensors to high resolution near-megapixel imager systems.

  3. Transient Stuttering in Catatonic Bipolar Patients

    Directory of Open Access Journals (Sweden)

    Anthony B. Joseph

    1991-01-01

    Full Text Available Two cases of transient stuttering occurring in association with catatonia and bipolar disorder are described. Affective decompensation has been associated with lateralized cerebral dysfunction, and it is hypothesized that in some bipolar catatonic patients a concomitant disorder of the lateralization of language function may lead to a variety of clinical presentations including aphasia, mutism, and stuttering.

  4. Bipolar Disorder and Cognitive Therapy: A Commentary

    Science.gov (United States)

    Riskind, John H.

    2005-01-01

    This article comments on the three articles (Leahy, 2005; Newman, 2005; and Reilly-Harrington & Knauz, 2005) that deal with the applications of cognitive therapy to treatment of bipolar disorder. They focus on the uses of cognitive therapy in treating three important facets of the special problems of bipolar patients: rapid cycling, severe…

  5. Developmental staging models in bipolar disorder

    OpenAIRE

    Passos, Ives C; Jansen, Karen; Kapczinski, Flavio

    2015-01-01

    The previous contribution of Duffy and colleagues suggests that a chain of behavioral events starting during childhood precedes the development of full-blown bipolar disorder. In this vein, the recent contribution of Keown-Stoneman and colleagues brings a new perspective to the study of prodromal symptoms of bipolar disorder.

  6. Modeling "Soft" Errors in Bipolar Integrated Circuits

    Science.gov (United States)

    Zoutendyk, J.; Benumof, R.; Vonroos, O.

    1985-01-01

    Mathematical models represent single-event upset in bipolar memory chips. Physics of single-event upset in integrated circuits discussed in theoretical paper. Pair of companion reports present mathematical models to predict critical charges for producing single-event upset in bipolar randomaccess memory (RAM) chips.

  7. Swimming in Deep Water: Childhood Bipolar Disorder

    Science.gov (United States)

    Senokossoff, Gwyn W.; Stoddard, Kim

    2009-01-01

    The authors focused on one parent's struggles in finding a diagnosis and intervention for a child who had bipolar disorder. The authors explain the process of identification, diagnosis, and intervention of a child who had bipolar disorder. In addition to the personal story, the authors provide information on the disorder and outline strategies…

  8. Bipolar disorder diagnosis: challenges and future directions.

    Science.gov (United States)

    Phillips, Mary L; Kupfer, David J

    2013-05-11

    Bipolar disorder refers to a group of affective disorders, which together are characterised by depressive and manic or hypomanic episodes. These disorders include: bipolar disorder type I (depressive and manic episodes: this disorder can be diagnosed on the basis of one manic episode); bipolar disorder type II (depressive and hypomanic episodes); cyclothymic disorder (hypomanic and depressive symptoms that do not meet criteria for depressive episodes); and bipolar disorder not otherwise specified (depressive and hypomanic-like symptoms that do not meet the diagnostic criteria for any of the aforementioned disorders). Bipolar disorder type II is especially difficult to diagnose accurately because of the difficulty in differentiation of this disorder from recurrent unipolar depression (recurrent depressive episodes) in depressed patients. The identification of objective biomarkers that represent pathophysiologic processes that differ between bipolar disorder and unipolar depression can both inform bipolar disorder diagnosis and provide biological targets for the development of new and personalised treatments. Neuroimaging studies could help the identification of biomarkers that differentiate bipolar disorder from unipolar depression, but the problem in detection of a clear boundary between these disorders suggests that they might be better represented as a continuum of affective disorders. Innovative combinations of neuroimaging and pattern recognition approaches can identify individual patterns of neural structure and function that accurately ascertain where a patient might lie on a behavioural scale. Ultimately, an integrative approach, with several biological measurements using different scales, could yield patterns of biomarkers (biosignatures) to help identify biological targets for personalised and new treatments for all affective disorders. PMID:23663952

  9. Thomson semiconductors bipolar IC strategy to 1986

    Science.gov (United States)

    Dellamussia, J. P.

    1984-04-01

    The strategy to develop and market bipolar integrated circuits through 1986 by thomson semiconductors is discussed. Current technology and future research on prototype microprocessors using bipolar integrated circuits is evaluated. The physical properties of the circuits such as heat dissipation, energy consumption rates and response times are studied.

  10. Luminescence properties of Ge implanted SiO2:Ge and GeO2:Ge films

    International Nuclear Information System (INIS)

    We have investigated cathodeluminescence (CL) of Ge implanted SiO2:Ge and GeO2:Ge films. The GeO2 films were grown by oxidation of Ge substrate at 550 deg. C for 3 h in O2 gas flow. The GeO2 films on Ge substrate and SiO2 films on Si substrate were implanted with Ge-negative ions. The implanted Ge atom concentrations in the films were ranging from 0.1 to 6.0 at%. To produce Ge nanoparticles the SiO2:Ge films were thermally annealed at various temperatures of 600-900 deg. C for 1 h in N2 gas flow. An XPS analysis has shown that the implanted Ge atoms were partly oxidized. CL was observed at wavelengths around 400 nm from the GeO2 films before and after Ge--implantation as well as from SiO2:Ge films. After Ge--implantation of about 0.5 at% the CL intensity has increased by about four times. However, the CL intensity from the GeO2:Ge films was several orders of magnitude smaller than the intensity from the 800 deg. C-annealed SiO2:Ge films with 0.5 at% of Ge atomic concentration. These results suggested that the luminescence was generated due to oxidation of Ge nanoparticles in the SiO2:Ge films.

  11. Simulation in Amorphous Silicon and Amorphous Silicon Carbide Pin Diodes

    OpenAIRE

    Gonçalves, Dora; Fernandes, Miguel; Louro, Paula; Fantoni, Alessandro; Vieira, Manuela

    2014-01-01

    Part 21: Electronics: Devices International audience Photodiodes are devices used as image sensors, reactive to polychromatic light and subsequently color detecting, and they are also used in optical communication applications. To improve these devices performance it is essential to study and control their characteristics, in fact their capacitance and spectral and transient responses. This study considers two types of diodes, an amorphous silicon pin and an amorphous silicon carbide pi...

  12. Diagnostic stability in pediatric bipolar disorder

    DEFF Research Database (Denmark)

    Vedel Kessing, Lars; Vradi, Eleni; Andersen, Per Kragh

    2015-01-01

    BACKGROUND: The diagnostic stability of pediatric bipolar disorder has not been investigated previously. The aim was to investigate the diagnostic stability of the ICD-10 diagnosis of pediatric mania/bipolar disorder.METHODS: All patients below 19 years of age who got a diagnosis of mania/bipolar...... disorder at least once in a period from 1994 to 2012 at psychiatric inpatient or outpatient contact in Denmark were identified in a nationwide register.RESULTS: Totally, 354 children and adolescents got a diagnosis of mania/bipolar disorder at least once; a minority, 144 patients (40.7%) got the diagnosis...... at the first contact whereas the remaining patients (210; 59.3%) got the diagnosis at later contacts before age 19. For the latter patients, the median time elapsed from first treatment contact with the psychiatric service system to the first diagnosis with a manic episode/bipolar disorder was nearly 1 year...

  13. Thyroid Functions and Bipolar Affective Disorder

    Directory of Open Access Journals (Sweden)

    Subho Chakrabarti

    2011-01-01

    Full Text Available Accumulating evidence suggests that hypothalamo-pituitary-thyroid (HPT axis dysfunction is relevant to the pathophysiology and clinical course of bipolar affective disorder. Hypothyroidism, either overt or more commonly subclinical, appears to the commonest abnormality found in bipolar disorder. The prevalence of thyroid dysfunction is also likely to be greater among patients with rapid cycling and other refractory forms of the disorder. Lithium-treatment has potent antithyroid effects and can induce hypothyroidism or exacerbate a preexisting hypothyroid state. Even minor perturbations of the HPT axis may affect the outcome of bipolar disorder, necessitating careful monitoring of thyroid functions of patients on treatment. Supplementation with high dose thyroxine can be considered in some patients with treatment-refractory bipolar disorder. Neurotransmitter, neuroimaging, and genetic studies have begun to provide clues, which could lead to an improved understanding of the thyroid-bipolar disorder connection, and more optimal ways of managing this potentially disabling condition.

  14. Charge trapping of Ge-nanocrystals embedded in TaZrO{sub x} dielectric films

    Energy Technology Data Exchange (ETDEWEB)

    Lehninger, D., E-mail: David.Lehninger@physik.tu-freiberg.de; Seidel, P.; Geyer, M.; Schneider, F.; Heitmann, J. [Institute of Applied Physics, TU Bergakademie Freiberg, D-09596 Freiberg (Germany); Klemm, V.; Rafaja, D. [Institute of Materials Science, TU Bergakademie Freiberg, D-09596 Freiberg (Germany); Borany, J. von [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden (Germany)

    2015-01-12

    Ge-nanocrystals (NCs) were synthesized in amorphous TaZrO{sub x} by thermal annealing of co-sputtered Ge-TaZrO{sub x} layers. Formation of spherical shaped Ge-NCs with small variation of size, areal density, and depth distribution was confirmed by high-resolution transmission electron microscopy. The charge storage characteristics of the Ge-NCs were investigated by capacitance-voltage and constant-capacity measurements using metal-insulator-semiconductor structures. Samples with Ge-NCs exhibit a maximum memory window of 5 V by sweeping the bias voltage from −7 V to 7 V and back. Below this maximum, the width of the memory window can be controlled by the bias voltage. The fitted slope of the memory window versus bias voltage characteristics is very close to 1 for samples with one layer Ge-NCs. A second layer Ge-NCs does not result in a second flat stair in the memory window characteristics. Constant-capacity measurements indicate charge storage in trapping centers at the interfaces between the Ge-NCs and the surrounding materials (amorphous matrix/tunneling oxide). Charge loss occurs by thermal detrapping and subsequent band-to-band tunneling. Reference samples without Ge-NCs do not show any memory window.

  15. Charge trapping of Ge-nanocrystals embedded in TaZrOx dielectric films

    International Nuclear Information System (INIS)

    Ge-nanocrystals (NCs) were synthesized in amorphous TaZrOx by thermal annealing of co-sputtered Ge-TaZrOx layers. Formation of spherical shaped Ge-NCs with small variation of size, areal density, and depth distribution was confirmed by high-resolution transmission electron microscopy. The charge storage characteristics of the Ge-NCs were investigated by capacitance-voltage and constant-capacity measurements using metal-insulator-semiconductor structures. Samples with Ge-NCs exhibit a maximum memory window of 5 V by sweeping the bias voltage from −7 V to 7 V and back. Below this maximum, the width of the memory window can be controlled by the bias voltage. The fitted slope of the memory window versus bias voltage characteristics is very close to 1 for samples with one layer Ge-NCs. A second layer Ge-NCs does not result in a second flat stair in the memory window characteristics. Constant-capacity measurements indicate charge storage in trapping centers at the interfaces between the Ge-NCs and the surrounding materials (amorphous matrix/tunneling oxide). Charge loss occurs by thermal detrapping and subsequent band-to-band tunneling. Reference samples without Ge-NCs do not show any memory window

  16. Effect of crystalline/amorphous interfaces on thermal transport across confined thin films and superlattices

    Science.gov (United States)

    Giri, Ashutosh; Braun, Jeffrey L.; Hopkins, Patrick E.

    2016-06-01

    We report on the thermal boundary resistances across crystalline and amorphous confined thin films and the thermal conductivities of amorphous/crystalline superlattices for Si/Ge systems as determined via non-equilibrium molecular dynamics simulations. Thermal resistances across disordered Si or Ge thin films increase with increasing length of the interfacial thin films and in general demonstrate higher thermal boundary resistances in comparison to ordered films. However, for films ≲3 nm, the resistances are highly dependent on the spectral overlap of the density of states between the film and leads. Furthermore, the resistances at a single amorphous/crystalline interface in these structures are much lower than those at interfaces between the corresponding crystalline materials, suggesting that diffusive scattering at an interface could result in higher energy transmissions in these systems. We use these findings, together with the fact that high mass ratios between amorphous and crystalline materials can lead to higher thermal resistances across thin films, to design amorphous/crystalline superlattices with very low thermal conductivities. In this regard, we study the thermal conductivities of amorphous/crystalline superlattices and show that the thermal conductivities decrease monotonically with increasing interface densities above 0.1 nm-1. These thermal conductivities are lower than that of the homogeneous amorphous counterparts, which alludes to the fact that interfaces non-negligibly contribute to thermal resistance in these superlattices. Our results suggest that the thermal conductivity of superlattices can be reduced below the amorphous limit of its material constituent even when one of the materials remains crystalline.

  17. Amorphous drugs and dosage forms

    DEFF Research Database (Denmark)

    Grohganz, Holger; Löbmann, K.; Priemel, P.;

    2013-01-01

    The transformation to an amorphous form is one of the most promising approaches to address the low solubility of drug compounds, the latter being an increasing challenge in the development of new drug candidates. However, amorphous forms are high energy solids and tend to recry stallize. New...... formulation principles are needed to ensure the stability of amorphous drug forms. The formation of solid dispersions is still the most investigated approach, but additional approaches are desirable to overcome the shortcomings of solid dispersions. Spatial separation by either coating or the use of micro......-containers has shown potential to prevent or delay recrystallization. Another recent approach is the formation of co-amorphous mixtures between either two drugs or one drug and one low molecular weight excipient. Molecular interactions between the two molecules provide an energy barrier that has to be overcome...

  18. Structural evolution of Ge-rich Si1−xGex films deposited by jet-ICPCVD

    International Nuclear Information System (INIS)

    Amorphous Ge-rich Si1−xGex films with local Ge-clustering were deposited by dual-source jet-type inductively coupled plasma chemical-vapor deposition (jet-ICPCVD). The structural evolution of the deposited films annealed at various temperatures (Ta) is investigated. Experimental results indicate that the crystallization occurs to form Ge and Si clusters as Ta = 500 °C. With raising Ta up to 900 °C, Ge clusters percolate together and Si diffuses and redistributes to form a Ge/SiGe core/shell structure, and some Ge atoms partially diffuse to the surface as a result of segregation. The present work will be helpful in understanding the structural evolution process of a hybrid SiGe films and beneficial for further optimizing the microstructure and properties

  19. Boron doping compensation of hydrogenated amorphous and polymorphous germanium thin films for infrared detection applications

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, M., E-mail: mmoreno@inaoep.mx [National Institute of Astrophysics, Optics and Electronics, INAOE, P.O. Box 51 and 216, Puebla, Z. P. 72840 Puebla (Mexico); Delgadillo, N. [Universidad Autónoma de Tlaxcala, Av. Universidad No. 1, Z. P. 90006 Tlaxcala (Mexico); Torres, A. [National Institute of Astrophysics, Optics and Electronics, INAOE, P.O. Box 51 and 216, Puebla, Z. P. 72840 Puebla (Mexico); Ambrosio, R. [Technology and Engineering Institute, Ciudad Juarez University UACJ, Av. Del Charro 450N, Z. P. 32310 Chihuahua (Mexico); Rosales, P.; Kosarev, A.; Reyes-Betanzo, C.; Hidalga-Wade, J. de la; Zuniga, C.; Calleja, W. [National Institute of Astrophysics, Optics and Electronics, INAOE, P.O. Box 51 and 216, Puebla, Z. P. 72840 Puebla (Mexico)

    2013-12-02

    In this work we have studied boron doping of hydrogenated amorphous germanium a-Ge:H and polymorphous germanium (pm-Ge:H) in low regimes, in order to compensate the material from n-type (due to oxygen contamination that commonly occurs during plasma deposition) to intrinsic, and in this manner improve the properties that are important for infrared (IR) detection, as activation energy (E{sub a}) and temperature coefficient of resistance (TCR). Electrical, structural and optical characterization was performed on the films produced. Measurements of the temperature dependence of conductivity, room temperature conductivity (σ{sub RT}), E{sub a} and current–voltage characteristics under IR radiation were performed in the compensated a-Ge:H and pm-Ge:H films. Our results demonstrate that, effectively, the values of E{sub a}, TCR and IR detection are improved on the a-Ge:H/pm-Ge:H films, using boron doping in low regimes, which results of interest for infrared detectors. - Highlights: • We reported boron doping compensation of amorphous and polymorphous germanium. • The films were deposited by plasma enhanced chemical vapor deposition. • The aim is to use the films as thermo-sensing elements in un-cooled microbolometers. • Those films have advantages over boron doped a-Si:H used in commercial detectors.

  20. Valproate, bipolar disorder and polycystic ovarian syndrome

    Directory of Open Access Journals (Sweden)

    Okanović Milana

    2016-01-01

    Full Text Available Introduction. Polycystic ovarian syndrome is a syndrome of ovarian dysfunction with the principal features of hyperandrogenism and polycystic ovary morphology. A large number of studies conducted on this topic have suggested a possible role of anticonvulsants, particularly valproate, in the pathogenesis or risk factors associated with polycystic ovarian syndrome. Bipolar treatment guidelines from Canada and the United States of America recommend valproate as the first line strategy in the acute treatment of bipolar disorder. Discussion. Most persons with bipolar disorder require maintenance treatment. Long-term administration of valproate in women with bipolar disorder or epilepsy is believed to result in the increased risk of hyperandro­genism, menstrual abnormalities and polycystic ovaries. Valproate may also increase the risk of infertility and other associated symptoms of polycystic ovarian syndrome. Therefore, particular caution is indicated in the use of valproate in women of reproductive age. Conclusion. The treatment of the female patients with bipolar disorder presents various challenges for the clinician. Every woman of reproductive age needs to know the risk and benefits of her pharmacologic treatment options. Bipolar disorder should be considered chronic disorder, whose development is largely affected by hormonal changes and reproductive cycle in women. These issues should be researched more thoroughly in order to opt for the most appropriate treatment in women with bipolar disorder.

  1. Amorphous carbon for photovoltaics

    Science.gov (United States)

    Risplendi, Francesca; Grossman, Jeffrey C.

    2015-03-01

    All-carbon solar cells have attracted attention as candidates for innovative photovoltaic devices. Carbon-based materials such as graphene, carbon nanotubes (CNT) and amorphous carbon (aC) have the potential to present physical properties comparable to those of silicon-based materials with advantages such as low cost and higher thermal stability.In particular a-C structures are promising systems in which both sp2 and sp3 hybridization coordination are present in different proportions depending on the specific density, providing the possibility of tuning their optoelectronic properties and achieving comparable sunlight absorption to aSi. In this work we employ density functional theory to design suitable device architectures, such as bulk heterojunctions (BHJ) or pn junctions, consisting of a-C as the active layer material.Regarding BHJ, we study interfaces between aC and C nanostructures (such as CNT and fullerene) to relate their optoelectronic properties to the stoichiometry of aC. We demonstrate that the energy alignment between the a-C mobility edges and the occupied and unoccupied states of the CNT or C60 can be widely tuned by varying the aC density to obtain a type II interface.To employ aC in pn junctions we analyze the p- and n-type doping of a-C focusingon an evaluation of the Fermi level and work function dependence on doping.Our results highlight promising features of aC as the active layer material of thin-film solar cells.

  2. Tratamento do transtorno bipolar: eutimia Bipolar disorder treatment: euthymia

    Directory of Open Access Journals (Sweden)

    Fábio Gomes de Matos e Souza

    2005-01-01

    Full Text Available O transtorno bipolar é um quadro complexo caracterizado por episódios de depressão, mania ou hipomania e fases assintomáticas. O tratamento visa ao controle de episódios agudos e prevenção de novos episódios. O tratamento farmacológico iniciou-se com o lítio. Até o momento, o lítio permanece como o tratamento com mais evidências favoráveis na fase de manutenção. Outros tratamentos demonstram eficácia nessa fase, como o valproato, a carbamazepina e os antipsicóticos atípicos. Dos antipsicóticos atípicos o mais estudado nesta fase do tratamento é a olanzapina. Mais estudos prospectivos são necessários para confirmar a ação profilática de novos agentes.Bipolar disorder is a complex disorder characterized by depression episodes, mania or hypomania and asymptomatic phases. The treatment aims at the control of acute episodes and prevention of new episodes. The pharmacological treatment was inaugurated with lithium. Until the moment, lithium remains as the treatment with more favorable evidences in the maintenance phase. Other treatments demonstrate efficacy in this phase, as valproate, carbamazepine and atypical antipsychotics. Of the atypical antipsychotics, the most studied in this phase of treatment is olanzapine. More prospective studies are necessary to confirm prophylactic action of new agents.

  3. Lower switch rate in depressed patients with bipolar II than bipolar I disorder treated adjunctively with second-generation antidepressants

    NARCIS (Netherlands)

    Altshuler, LL; Suppes, T; Nolen, WA; Leverich, G; Keck, PE; Frye, MA; Kupka, R; McElroy, SL; Grunze, H; Kitchen, CMR; Post, R; Black, D.O.

    2006-01-01

    Objectives: The authors compared the switch rate into hypomania/mania in depressed patients treated with second-generation antidepressants who had either bipolar I or bipolar II disorder. Method: In a 10-week trial, 184 outpatients with bipolar depression (134 with bipolar I disorder, 48 with bipola

  4. Nanomechanical morphology of amorphous, transition, and crystalline domains in phase change memory thin films

    Energy Technology Data Exchange (ETDEWEB)

    Bosse, J.L. [Department of Materials Science and Engineering, University of Connecticut, 97 North Eagleville Road, Unit 3136, Storrs, CT 06269-3136 (United States); Grishin, I. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom); Huey, B.D. [Department of Materials Science and Engineering, University of Connecticut, 97 North Eagleville Road, Unit 3136, Storrs, CT 06269-3136 (United States); Kolosov, O.V., E-mail: o.kolosov@lancaster.ac.uk [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)

    2014-09-30

    Highlights: • The nanomechanical morphology of GeTe and Ge{sub 2}Sb{sub 2}Te{sub 5} phase change memory thin films are investigated with combined ultrasonic force microscopy and beam exit Ar ion polishing. • Both plan-view and shallow-angle cross-sections are investigated for each stoichiometry. • Contrast in the nanomechanical response due to stiffness variations between the amorphous and crystalline phases are demonstrated up to 14% and 20% for the normal and cross-sectioned films, respectively. - Abstract: In the search for phase change materials (PCM) that may rival traditional random access memory, a complete understanding of the amorphous to crystalline phase transition is required. For the well-known Ge{sub 2}Sb{sub 2}Te{sub 5} (GST) and GeTe (GT) chalcogenides, which display nucleation and growth dominated crystallization kinetics, respectively, this work explores the nanomechanical morphology of amorphous and crystalline phases in 50 nm thin films. Subjecting these PCM specimens to a lateral thermal gradient spanning the crystallization temperature allows for a detailed morphological investigation. Surface and depth-dependent analyses of the resulting amorphous, transition and crystalline regions are achieved with shallow angle cross-sections, uniquely implemented with beam exit Ar ion polishing. To resolve the distinct phases, ultrasonic force microscopy (UFM) with simultaneous topography is implemented revealing a relative stiffness contrast between the amorphous and crystalline phases of 14% for the free film surface and 20% for the cross-sectioned surface. Nucleation is observed to occur preferentially at the PCM-substrate and free film interface for both GST and GT, while fine subsurface structures are found to be sputtering direction dependent. Combining surface and cross-section nanomechanical mapping in this manner allows 3D analysis of microstructure and defects with nanoscale lateral and depth resolution, applicable to a wide range of

  5. Vacuum interface flashover with bipolar electric fields

    International Nuclear Information System (INIS)

    High energy, compact, particle accelerators require accelerating cavities that have large gradients and operate with high efficiency. The bipolar electric fields necessary in these efficient accelerating cavities place severe requirements on the insulator-vacuum interface. A new interface has been designed and 50 gv/cm bipolar flashover field achieved for a waveform train that lasted 1 μs. This paper discusses the design of this vacuum interface and the evaluation of various materials that led to achieving bipolar flashover fields 50% greater than the authors had previously obtained

  6. A SiGe BiCMOS double-balanced mixer with active balun for X-band Doppler radar

    DEFF Research Database (Denmark)

    Michaelsen, Rasmus S.; Johansen, Tom K.; Tamborg, Kjeld M.;

    2015-01-01

    In this paper, we present an X-band doublebalanced mixer in SiGe BiCMOS technology. The mixer core consists of a LO Matched quad diode ring using diode-connected Heterojunction Bipolar Transistors (HBTs). The mixer is integrated with a low-noise, high-linearity active balun on the RF port...

  7. Raman spectra and XPS studies of phase changes in Ge2Sb2Te5 films

    Institute of Scientific and Technical Information of China (English)

    Liu Bo; Song Zhi-Tang; Zhang Ting; Feng Song-Lin; Chen Bomy

    2004-01-01

    Ge2Sb2Te5 film was deposited by RF magnetron sputtering on Si (100) substrate. The structure of amorphous and crystalline Ge2Sb2Te5 thin films was investigated using XRD, Raman spectra and XPS. XRD measurements revealed the existence of two different crystalline phases, which has a FCC structure and a hexagonal structure, respectively.The broad peak in the Raman spectra of amorphous Ge2Sb2Te5 film is due to the amorphous -Te-Te- stretching. As the annealing temperature increases, the broad peak separates into two peaks, which indicates that the heteropolar bond in GeTe4 and the Sb-Sb bond are connected with four Te atoms, and other units such as (TeSb) Sb-Sb (Te2)and (Sb2) Sb-Sb (Te2), where some of the four Te atoms in the above formula are replaced by Sb atoms, remain in crystalline Ge2Sb2Te5 thin film. And from the results of Raman spectra and XPS, higher the annealing temperature,more Te atoms bond to Ge atoms and more Sb atoms substitute Te in (Te2) Sb-Sb (Te2).

  8. Study of Ge2Sb2Te5 Film for Nonvolatile Memory Medium

    Institute of Scientific and Technical Information of China (English)

    Baowei QIAO; Yunfeng LAI; Jie FENG; Yun LING; Yinyin LIN; Ting'ao TANG; Bingchu CAI; Bomy CHEN

    2005-01-01

    The amorphous Ge2Sb2Te5 film with stoichiometric compositions was deposited by co-sputtering of separate Ge,Sb, and Te targets on SiO2/Si (100) wafer in ultrahigh vacuum magnetron sputtering apparatus. The crystallization behavior of amorphous Ge2Sb2Te5 film was investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and differential scanning calorimetry (DSC). With an increase of annealing temperature, the amorphous Ge2Sb2Te5 film undergoes a two-step crystallization process that it first crystallizes in face-centered-cubic (fcc) crystal structure and finally fcc structure changes to hexagonal (hex) structure. Activation energy values of 3.636±0.137and 1.579±0.005 eV correspond to the crystallization and structural transformation processes, respectively. From annealing temperature dependence of the film resistivity, it is determined th at the first steep decrease of the resistivity corresponds to crystallization while the second one is primarily caused by structural transformation from "fcc"to "hex" and growth of the crystal grains. Current-voltage (I-V) characteristics of the device with 40 nm-thick Ge2Sb2Te5 film show that the Ge2Sb2Te5 film with nanometer order thickness is still applicable for memory medium of nonvolatile phase change memory.

  9. Ferromagnetic Fe-based Amorphous Alloy with High Glass-forming Ability

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A ferromagnetic amorphous Fe73Al4Ge2Nb1P10C6B4 alloy with highglass-forming ability was synthesized by melt spinning. The supercooled liquid region before crystallization reaches about 65.7 K. The crystallized structure consists of α-Fe, Fe3B, FeB, Fe3P and Fe3C phases. The Febased amorphous alloy exhibits good magnetic properties with a high saturation magnetization and a low saturated magnetostriction. The crystallization leads to an obvious decrease in the soft magnetic properties.

  10. Comorbidade com transtornos de ansiedade em transtorno bipolar Anxiety disorders comorbidity in bipolar disorder

    Directory of Open Access Journals (Sweden)

    Cilly Klüger Issler

    2004-10-01

    Full Text Available Comorbidade elevada de transtornos de ansiedade em bipolares é freqüentemente relatada em estudos epidemiológicos e clínicos. A associação tem implicações importantes no diagnóstico, evolução clínica, tratamento e prognóstico do transtorno bipolar, que são apresentadas nesta revisão.High comorbidity between bipolar and anxiety disorders is frequently described in epidemiological and clinical studies. This association has important implications for diagnoses, clinical outcome, therapeutic intervention and prognoses of bipolar disorder that are presented in this review.

  11. Overview of patient care issues and treatment in bipolar spectrum and bipolar II disorder.

    Science.gov (United States)

    Calabrese, Joseph R

    2008-06-01

    Recent studies have reported lifetime prevalence estimates of 1.0% for bipolar I disorder, 1.1% for bipolar II disorder, and 2.4% to 4.7% for subthreshold bipolar disorder, illustrating the need for consensus definitions of bipolar spectrum disorders. These definitions will aid researchers in studying viable treatments options, as well as help clinicians in the differential diagnosis of patients. Broader definitions of bipolar spectrum disorders would also allow clinicians to more accurately diagnose patients, rather than placing them in the catchall category of bipolar disorder not otherwise specified. Bipolar symptoms that are currently labeled as subthreshold symptoms are becoming increasingly recognized as having relevant clinical implications. Despite diagnostic controversy, screening for the presence of mania in patients who present with depressive symptoms is a critical step in the appropriate treatment of bipolar spectrum disorders. Identifying the early onset of bipolar symptoms as manifested in prodromal disorders such as childhood major depressive disorder and attention-deficit/hyperactivity disorder is also important for possible early intervention and improved outcomes.

  12. Electronic transport in amorphous phase-change materials

    Energy Technology Data Exchange (ETDEWEB)

    Luckas, Jennifer Maria

    2012-09-14

    Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. Starting from a brief introduction of the physics of phase-change materials this thesis summarizes the most important models behind electrical switching and resistance drift with the aim to discuss the role of localized defect states. The centerpiece of this thesis is the investigation of defects state densities in different amorphous phase-change materials and electrical switching chalcogenides. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Deflection Spectroscopy, a sophisticated band model for the disordered phase of the binary phase-change alloy GeTe has been developed. By this direct experimental approach the band-model for a-Ge

  13. Bipolar disorder and neurophysiologic mechanisms

    Directory of Open Access Journals (Sweden)

    Simon M McCrea

    2008-11-01

    Full Text Available Simon M McCreaDepartments of Neurology and Neuroophthalmology, University of British Columbia, 2550 Willow Street, Vancouver, British Columbia, Canada V5Z 3N9Abstract: Recent studies have suggested that some variants of bipolar disorder (BD may be due to hyperconnectivity between orbitofrontal (OFC and temporal pole (TP structures in the dominant hemisphere. Some initial MRI studies noticed that there were corpus callosum abnormalities within specific regional areas and it was hypothesized that developmentally this could result in functional or effective connectivity changes within the orbitofrontal-basal ganglia-thalamocortical circuits. Recent diffusion tensor imaging (DTI white matter fiber tractography studies may well be superior to region of interest (ROI DTI in understanding BD. A “ventral semantic stream” has been discovered connecting the TP and OFC through the uncinate and inferior longitudinal fasciculi and the elusive TP is known to be involved in theory of mind and complex narrative understanding tasks. The OFC is involved in abstract valuation in goal and sub-goal structures and the TP may be critical in binding semantic memory with person–emotion linkages associated with narrative. BD patients have relative attenuation of performance on visuoconstructional praxis consistent with an atypical localization of cognitive functions. Multiple lines of evidence suggest that some BD alleles are being selected for which could explain the enhanced creativity in higher-ability probands. Associations between ROI’s that are not normally connected could explain the higher incidence of artistic aptitude, writing ability, and scientific achievements among some mood disorder subjects.Keywords: bipolar disorder, diffusion tensor imaging, white matter tractography, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, mood dysphoria, creativity, ventral semantic stream, writing ability, artistic aptitude

  14. On coarse projective integration for atomic deposition in amorphous systems

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Claire Y., E-mail: yungc@seas.upenn.edu, E-mail: meister@unm.edu, E-mail: zepedaruiz1@llnl.gov; Sinno, Talid, E-mail: talid@seas.upenn.edu [Department of Chemical and Biomolecular Engineering, University of Pennsylvania, 220 South 33rd Street, 311A Towne Building, Philadelphia, Pennsylvania 19104 (United States); Han, Sang M., E-mail: yungc@seas.upenn.edu, E-mail: meister@unm.edu, E-mail: zepedaruiz1@llnl.gov [Department of Chemical and Biological Engineering, University of New Mexico, 1 University of New Mexico, MSC01 1120, Albuquerque, New Mexico 87131 (United States); Zepeda-Ruiz, Luis A., E-mail: yungc@seas.upenn.edu, E-mail: meister@unm.edu, E-mail: zepedaruiz1@llnl.gov [Lawrence Livermore National Laboratory, P.O. Box 808, L-367, Livermore, California 94550 (United States)

    2015-10-07

    Direct molecular dynamics simulation of atomic deposition under realistic conditions is notoriously challenging because of the wide range of time scales that must be captured. Numerous simulation approaches have been proposed to address the problem, often requiring a compromise between model fidelity, algorithmic complexity, and computational efficiency. Coarse projective integration, an example application of the “equation-free” framework, offers an attractive balance between these constraints. Here, periodically applied, short atomistic simulations are employed to compute time derivatives of slowly evolving coarse variables that are then used to numerically integrate differential equations over relatively large time intervals. A key obstacle to the application of this technique in realistic settings is the “lifting” operation in which a valid atomistic configuration is recreated from knowledge of the coarse variables. Using Ge deposition on amorphous SiO{sub 2} substrates as an example application, we present a scheme for lifting realistic atomistic configurations comprised of collections of Ge islands on amorphous SiO{sub 2} using only a few measures of the island size distribution. The approach is shown to provide accurate initial configurations to restart molecular dynamics simulations at arbitrary points in time, enabling the application of coarse projective integration for this morphologically complex system.

  15. Are rates of pediatric bipolar disorder increasing?

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Vradi, Eleni; Andersen, Per Kragh

    2014-01-01

    Studies from the USA suggest that rates of pediatric bipolar disorder have increased since the mid-90s, but no study outside the USA has been published on the rates of pediatric bipolar disorder. Further, it is unclear whether an increase in rates reflects a true increase in the illness or more...... diagnostic attention. Using nationwide registers of all inpatients and outpatients contacts to all psychiatric hospitals in Denmark, we investigated (1) gender-specific rates of incident pediatric mania/bipolar disorder during a period from 1995 to 2012, (2) whether age and other characteristics...... for pediatric mania/bipolar disorder changed during the calendar period (1995 to 2003 versus 2004 to 2012), and (3) whether the diagnosis is more often made at first psychiatric contact in recent time compared to earlier according to gender. Totally, 346 patients got a main diagnosis of a manic episode (F30...

  16. White matter microstructure alterations in bipolar disorder

    Science.gov (United States)

    Bellani, Marcella; Perlini, Cinzia; Ferro, Adele; Cerruti, Stefania; Rambaldelli, Gianluca; Isola, Miriam; Cerini, Roberto; Dusi, Nicola; Andreone, Nicola; Balestrieri, Matteo; Mucelli, Roberto Pozzi; Tansella, Michele; Brambilla, Paolo

    2012-01-01

    Summary Genetic, neuropathological and magnetic resonance imaging findings support the presence of diffuse white matter cytoarchitectural disruption in bipolar disorder. In this study, diffusion-weighted imaging (DWI) was applied to study cortical white matter microstructure organisation in 24 patients with DSM-IV bipolar disorder and 35 matched normal controls. DWI images were obtained using a 1.5 Tesla scanner and apparent diffusion coefficient (ADC) values were determined over regions of interest placed, bilaterally, in the frontal, temporal, parietal, and occipital white matter. Significantly increased ADC values were found in bipolar patients with respect to normal controls in the right temporal lobe, left parietal lobe and bilateral occipital lobes. ADC values did not associate significantly with age or with clinical variables (p>0.05). Diffuse cortical white matter alterations on DWI in bipolar disorder denote widespread disruption of white matter integrity and may be due to altered myelination and/or axonal integrity. PMID:22687164

  17. [Bipolar patients, structured psychotherapeutic treatment and approaches].

    Science.gov (United States)

    Bonvalot, Thierry; Mazouni, Rabbah; Rivallan, Armel; Lassignardie, Hélène

    2010-01-01

    The current development of structured psychotherapy has brought gradual improvements to the treatment provided to bipolar patients. This psychotherapy may be either carried out individually or in a group. In this context, psychotherapeutic meditation seems beneficial.

  18. Nanostructures having crystalline and amorphous phases

    Science.gov (United States)

    Mao, Samuel S; Chen, Xiaobo

    2015-04-28

    The present invention includes a nanostructure, a method of making thereof, and a method of photocatalysis. In one embodiment, the nanostructure includes a crystalline phase and an amorphous phase in contact with the crystalline phase. Each of the crystalline and amorphous phases has at least one dimension on a nanometer scale. In another embodiment, the nanostructure includes a nanoparticle comprising a crystalline phase and an amorphous phase. The amorphous phase is in a selected amount. In another embodiment, the nanostructure includes crystalline titanium dioxide and amorphous titanium dioxide in contact with the crystalline titanium dioxide. Each of the crystalline and amorphous titanium dioxide has at least one dimension on a nanometer scale.

  19. Fundamentals of amorphous solids structure and properties

    CERN Document Server

    Stachurski, Zbigniew H

    2014-01-01

    Long awaited, this textbook fills the gap for convincing concepts to describe amorphous solids. Adopting a unique approach, the author develops a framework that lays the foundations for a theory of amorphousness. He unravels the scientific mysteries surrounding the topic, replacing rather vague notions of amorphous materials as disordered crystalline solids with the well-founded concept of ideal amorphous solids. A classification of amorphous materials into inorganic glasses, organic glasses, glassy metallic alloys, and thin films sets the scene for the development of the model of ideal amorph

  20. Degradation of SiGe devices by proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ohyama, Hidenori; Hayama, Kiyoteru [Kumamoto National Coll. of Technology, Nishigoshi (Japan); Vanhellemont, J.; Takami, Yasukiyo; Sunaga, Hiromi; Nashiyama, Isamu; Uwatoko, Yoshiya; Poortmans, J.; Caymax, M.

    1997-03-01

    The degradation and recovery behavior of strained Si{sub 1-x}Ge{sub x} diodes and heterojunction bipolar transistors (HBTs) by irradiated by protons are studied. The degradation of device performance and the generation of lattice defects are reported as a function of fluence and germanium content and also compared extensively with previous results obtained on electron and neutron irradiated devices. In order to study the recovery behavior of the irradiated devices, isochronal annealing is performed. The radiation source dependence of the degradation is discussed taking into account the number of knock-on atoms and the nonionizing energy loss (NIEL). (author)

  1. Inversion of diffraction data for amorphous materials

    Science.gov (United States)

    Pandey, Anup; Biswas, Parthapratim; Drabold, D. A.

    2016-09-01

    The general and practical inversion of diffraction data–producing a computer model correctly representing the material explored–is an important unsolved problem for disordered materials. Such modeling should proceed by using our full knowledge base, both from experiment and theory. In this paper, we describe a robust method to jointly exploit the power of ab initio atomistic simulation along with the information carried by diffraction data. The method is applied to two very different systems: amorphous silicon and two compositions of a solid electrolyte memory material silver-doped GeSe3. The technique is easy to implement, is faster and yields results much improved over conventional simulation methods for the materials explored. By direct calculation, we show that the method works for both poor and excellent glass forming materials. It offers a means to add a priori information in first-principles modeling of materials, and represents a significant step toward the computational design of non-crystalline materials using accurate interatomic interactions and experimental information.

  2. Effect of the addition of Ge to the FINEMET alloy

    International Nuclear Information System (INIS)

    The results obtained by partially substituting Ge for B and Si in the FINEMET alloy for the purpose of improving its magnetic properties at high temperatures are presented in this work. Nanocrystalline ribbons were obtained from controlled crystallization of amorphous material made employing the melt spinning technique. The studied compositions were: Fe73.5Si13.5Ge2Nb3B7Cu1 and Fe73.5Si13.5Ge4Nb3B5Cu1. The structural evolution of these alloys was studied using X-ray diffraction (XRD) and differential scanning calorimetry (DSC) and these results were correlated with their magnetic properties at different annealing temperatures. The coercivity obtained for both alloys was below 1 A/m at anneling temperatures between 773 and 823 K. The amorphous saturation magnetization was satisfactory, almost 137 emu/g, comparable with that obtained for FINEMET alloys. The nanocrystallization and the Curie temperatures are dependent on Ge concentration

  3. O transtorno bipolar na mulher Bipolar disorder in women

    Directory of Open Access Journals (Sweden)

    Alexandro de Borja Gonçalves Guerra

    2005-01-01

    Full Text Available Diferenças sexuais, descritas em vários transtornos psiquiátricos, também parecem estar presentes no transtorno afetivo bipolar (TAB. A prevalência do TAB tipo I se distribui igualmente entre mulheres e homens. Mulheres parecem estar sujeitas a um risco maior de ciclagem rápida e mania mista, condições que fariam do TAB um transtorno com curso mais prejudicial no sexo feminino. Uma diátese depressiva mais marcante, uso excessivo de antidepressivos e diferenças hormonais surgem como hipóteses para explicar essas diferenças fenomenológicas, apesar das quais, mulheres e homens parecem responder igualmente ao tratamento medicamentoso. A indicação de anticonvulsivantes como primeira escolha em mulheres é controversa, a não ser para o tratamento da mania mista e, talvez, da ciclagem rápida. O tratamento do TAB na gravidez deve levar em conta tanto os riscos de exposição aos medicamentos quanto à doença materna. A profilaxia do TAB no puerpério está fortemente indicada em decorrência do grande risco de recorrência da doença nesse período. Embora, de modo geral, as medicações psicotrópicas estejam contra-indicadas durante a amamentação, entre os estabilizadores do humor, a carbamazepina e o valproato são mais seguros do que o lítio. Mais estudos são necessários para a confirmação das diferenças de curso do TAB entre mulheres e homens e a investigação de possíveis diferenças na efetividade dos tratamentos.Gender differences, described in several psychiatric disorders, seem to be also present in bipolar disorder (BD. The prevalence of bipolar I disorder is equally distributed between women and men. Women seem to be at higher risk for rapid cycling and mixed mania, conditions that could make BD a disorder with a more severe course in the female sex. A marked depressive diathesis among women, greatest use of antidepressants and hormonal differences have been mentioned as hypotheses to explain these

  4. Amorphization of Crystalline Water Ice

    CERN Document Server

    Zheng, Weijun; Kaiser, Ralf I

    2008-01-01

    We conducted a systematic experimental study to investigate the amorphization of crystalline ice by irradiation in the 10-50 K temperature range with 5 keV electrons at a dose of ~140 eV per molecule. We found that crystalline water ice can be converted partially to amorphous ice by electron irradiation. Our experiments showed that some of the 1.65-micrometer band survived the irradiation, to a degree that depends on the temperature, demonstrating that there is a balance between thermal recrystallization and irradiation-induced amorphization, with thermal recrystallizaton dominant at higher temperatures. At 50 K, recrystallization due to thermal effects is strong, and most of the crystalline ice survived. Temperatures of most known objects in the solar system, including Jovian satellites, Saturnian satellites, and Kuiper belt objects, are equal to or above 50 K, this might explain why water ice detected on those objects is mostly crystalline.

  5. Bipolar Saline TURP for Large Prostate Glands

    OpenAIRE

    Finley, David S.; Shawn Beck; Szabo, Richard J.

    2007-01-01

    The objective of this study was to evaluate the feasibility of bipolar transurethral resection of the prostate ( TURP) in patients with very large prostate glands and significant comorbidities. Four patients with prostate glands > 160 cc on preoperative volume measurement and ASA class three or higher underwent bipolar TURP with the Gyrus PlasmaKinetic system. Preoperative, operative, and postoperative parameters were studied. The results showed an average ASA class 3.25 (range: 3-4). The ave...

  6. Bipolar Harmonic encoding of CMB correlation patterns

    OpenAIRE

    Joshi, Nidhi; Jhingan, Sanjay; Souradeep, Tarun; Hajian, Amir

    2009-01-01

    Deviations from statistical isotropy can be modeled in various ways, for instance, anisotropic cosmological models (Bianchi models), compact topologies and presence of primordial magnetic field. Signature of anisotropy manifests itself in CMB correlation patterns. Here we explore the symmetries of the correlation function and its implications on the observable measures constructed within the Bipolar harmonic formalism for these variety of models. Different quantifiers within the Bipolar harmo...

  7. Integrating Bipolar Disorder Management in Primary Care

    OpenAIRE

    Kilbourne, Amy M.; Goodrich, David E.; O’Donnell, Allison N.; Miller, Christopher J.

    2012-01-01

    There is growing realization that persons with bipolar disorder may exclusively be seen in primary (general medical) care settings, notably because of limited access to mental health care and stigma in seeking mental health treatment. At least two clinical practice guidelines for bipolar disorder recommend collaborative chronic care models (CCMs) to help integrate mental health care to better manage this illness. CCMs, which include provider guideline support, self-management support, care ma...

  8. Homocysteine and cognitive functions in bipolar depression

    OpenAIRE

    Agnieszka Permoda-Osip; Jacek Kisielewski; Jolanta Dorszewska; Janusz Rybakowski

    2014-01-01

    Objectives The aim of the study was to evaluate a relationship between concentrations of hoocysteine (HCY), vitamin B12 and folic acid and disturbances of cognitive functions during acute episode of bipolar depression. Methods 116 patients were studied (93 women, 23 men), aged 20-78 (mean 51±13) years during acute episode of bipolar depression. Depression was evaluated by the 17-item Hamilton’s Depression Rating Scale (HDRS). The following tests measuring cognitive functions were ap...

  9. Optimising the management of bipolar disorder.

    Science.gov (United States)

    MsAbda Mahmood; Ebmeler, Klaus R

    2015-05-01

    NICE recommends that when adults present in primary care with depression, they should be asked about previous periods of overactivity or disinhibited behaviour. If this behaviour lasted for four or more days referral for a specialist mental health assessment should be considered. Although depressive episodes are not necessary for a diagnosis of bipolar disorder, they are common and dominate the lifetime pattern of the condition: 50% of the time is spent in a euthymic (well) state, 38% in a depressed and 12% in a manic state. If there have only been depressive symptoms, it is not possible to exclude bipolar disorder. A diagnosis of bipolar disorder is supported by diagnostic criteria and usually confirmed by a psychiatrist. If the GP suspects mania or severe depression, or if patients are a danger to themselves or others, an urgent referral should be made for a specialist mental health assessment. If a manic episode has been present during the history the diagnosis is bipolar I disorder, while a hypomanic episode is indicative of bipolar disorder. The patient's care plan should include current health status, social situation, social support, co-ordination arrangements with secondary care, details of early warning signs, and the patient's preferred course of action in the event of a clinical relapse. Physical health checks should focus on cardiovascular disease, diabetes, obesity and respiratory disease given the heightened risk for these illnesses in bipolar disorder. PMID:27254890

  10. The role of sleep in bipolar disorder

    Directory of Open Access Journals (Sweden)

    Gold AK

    2016-06-01

    Full Text Available Alexandra K Gold,1 Louisa G Sylvia,1,2 1Department of Psychiatry, Massachusetts General Hospital, 2Harvard Medical School, Boston, MA, USA Abstract: Bipolar disorder is a serious mental illness characterized by alternating periods of elevated and depressed mood. Sleep disturbances in bipolar disorder are present during all stages of the condition and exert a negative impact on overall course, quality of life, and treatment outcomes. We examine the partnership between circadian system (process C functioning and sleep–wake homeostasis (process S on optimal sleep functioning and explore the role of disruptions in both systems on sleep disturbances in bipolar disorder. A convergence of evidence suggests that sleep problems in bipolar disorder result from dysregulation across both process C and process S systems. Biomarkers of depressive episodes include heightened fragmentation of rapid eye movement (REM sleep, reduced REM latency, increased REM density, and a greater percentage of awakenings, while biomarkers of manic episodes include reduced REM latency, greater percentage of stage I sleep, increased REM density, discontinuous sleep patterns, shortened total sleep time, and a greater time awake in bed. These findings highlight the importance of targeting novel treatments for sleep disturbance in bipolar disorder. Keywords: bipolar disorder, circadian rhythms, sleep–wake homeostasis

  11. Rumination in bipolar disorder: evidence for an unquiet mind

    Directory of Open Access Journals (Sweden)

    Ghaznavi Sharmin

    2012-01-01

    Full Text Available Abstract Depression in bipolar disorder has long been thought to be a state characterized by mental inactivity. However, recent research demonstrates that patients with bipolar disorder engage in rumination, a form of self-focused repetitive cognitive activity, in depressed as well as in manic states. While rumination has long been associated with depressed states in major depressive disorder, the finding that patients with bipolar disorder ruminate in manic states is unique to bipolar disorder and challenges explanations put forward for why people ruminate. We review the research on rumination in bipolar disorder and propose that rumination in bipolar disorder, in both manic and depressed states, reflects executive dysfunction. We also review the neurobiology of bipolar disorder and recent neuroimaging studies of rumination, which is consistent with our hypothesis that the tendency to ruminate reflects executive dysfunction in bipolar disorder. Finally, we relate the neurobiology of rumination to the neurobiology of emotion regulation, which is disrupted in bipolar disorder.

  12. Epitaxial growth of Ge-Sb-Te based phase change materials

    International Nuclear Information System (INIS)

    Ge-Sb-Te based phase change materials are considered as a prime candidate for optical and electrical data storage applications. With the application of an optical or electrical pulse, they can be reversibly switched between amorphous and crystalline state, thereby exhibiting large optical and electrical contrast between the two phases, which are then stored as information in the form of binary digits. Single crystalline growth is interesting from both the academic and industrial perspective, as ordered Ge-Sb-Te based metamaterials are known to exhibit switching at reduced energies. The present study deals with the epitaxial growth and analysis of Ge-Sb-Te based thin films. The first part of the thesis deals with the epitaxial growth of GeTe. Thin films of GeTe were grown on highly mismatched Si(111) and (001) substrates. On both the substrate orientations the film grows along [111] direction with an amorphous-to-crystalline transition observed during the initial stages of growth. The amorphous-to-crystalline transition was studied in-vivo using azimuthal reflection high-energy electron diffraction scans and grazing incidence X-ray diffraction. In the second part of the thesis epitaxy and characterization of Sb2Te3 thin films are presented. The third part of the thesis deals with the epitaxy of ternary Ge-Sb-Te alloys. The composition of the films are shown to be highly dependent on growth temperatures and vary along the pseudobinary line from Sb2Te3 to GeTe with increase in growth temperatures. A line-of-sight quadrupole mass spectrometer was used to reliably control the GeSbTe growth temperature. Growth was performed at different Ge, Sb, Te fluxes to study the compositional variation of the films. Incommensurate peaks are observed along the [111] direction by X-ray diffraction. The possibility of superstructural vacancy ordering along the [111] direction is discussed.

  13. Epitaxial growth of Ge-Sb-Te based phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Perumal, Karthick

    2013-07-30

    Ge-Sb-Te based phase change materials are considered as a prime candidate for optical and electrical data storage applications. With the application of an optical or electrical pulse, they can be reversibly switched between amorphous and crystalline state, thereby exhibiting large optical and electrical contrast between the two phases, which are then stored as information in the form of binary digits. Single crystalline growth is interesting from both the academic and industrial perspective, as ordered Ge-Sb-Te based metamaterials are known to exhibit switching at reduced energies. The present study deals with the epitaxial growth and analysis of Ge-Sb-Te based thin films. The first part of the thesis deals with the epitaxial growth of GeTe. Thin films of GeTe were grown on highly mismatched Si(111) and (001) substrates. On both the substrate orientations the film grows along [111] direction with an amorphous-to-crystalline transition observed during the initial stages of growth. The amorphous-to-crystalline transition was studied in-vivo using azimuthal reflection high-energy electron diffraction scans and grazing incidence X-ray diffraction. In the second part of the thesis epitaxy and characterization of Sb{sub 2}Te{sub 3} thin films are presented. The third part of the thesis deals with the epitaxy of ternary Ge-Sb-Te alloys. The composition of the films are shown to be highly dependent on growth temperatures and vary along the pseudobinary line from Sb{sub 2}Te{sub 3} to GeTe with increase in growth temperatures. A line-of-sight quadrupole mass spectrometer was used to reliably control the GeSbTe growth temperature. Growth was performed at different Ge, Sb, Te fluxes to study the compositional variation of the films. Incommensurate peaks are observed along the [111] direction by X-ray diffraction. The possibility of superstructural vacancy ordering along the [111] direction is discussed.

  14. Iron - based bulk amorphous alloys

    Directory of Open Access Journals (Sweden)

    R. Babilas

    2010-07-01

    Full Text Available Purpose: The paper presents a structure characterization, thermal and soft magnetic properties analysis of Fe-based bulk amorphous materials in as-cast state and after crystallization process. In addition, the paper gives some brief review about achieving, formation and structure of bulk metallic glasses as a special group of amorphous materials.Design/methodology/approach: The studies were performed on Fe72B20Si4Nb4 metallic glass in form of ribbons and rods. The amorphous structure of tested samples was examined by X-ray diffraction (XRD, transmission electron microscopy (TEM and scanning electron microscopy (SEM methods. The thermal properties of the glassy samples were measured using differential thermal analysis (DTA and differential scanning calorimetry (DSC. The magnetic properties contained initial and maximum magnetic permeability, coercive force and magnetic after-effects measurements were determined by the Maxwell-Wien bridge and VSM methods.Findings: The X-ray diffraction and transmission electron microscopy investigations revealed that the studied as-cast bulk metallic glasses in form of ribbons and rods were amorphous. Two stage crystallization process was observed for studied bulk amorphous alloy. The differences of crystallization temperature between ribbons and rods with chosen thickness are probably caused by different amorphous structures as a result of the different cooling rates in casting process. The SEM images showed that studied fractures could be classified as mixed fractures with indicated two zones contained “river” and “smooth” areas. The changing of chosen soft magnetic properties (μr, Bs, Hc obtained for samples with different thickness is a result of the non-homogenous amorphous structure of tested metallic glasses. The annealing process in temperature range from 373 to 773 K causes structural relaxation of tested amorphous materials, which leads to changes in their physical properties. The qualitative

  15. Temporal order of bipolar cell genesis in the neural retina

    Directory of Open Access Journals (Sweden)

    Chen C-M Amy

    2008-01-01

    Full Text Available Abstract Background Retinal bipolar cells comprise a diverse group of neurons. Cone bipolar cells and rod bipolar cells are so named for their connections with cone and rod photoreceptors, respectively. Morphological criteria have been established that distinguish nine types of cone bipolar cells and one type of rod bipolar cell in mouse and rat. While anatomical and physiological aspects of bipolar types have been actively studied, little is known about the sequence of events that leads to bipolar cell type specification and the potential relationship this process may have with synapse formation in the outer plexiform layer. In this study, we have examined the birth order of rod and cone bipolar cells in the developing mouse and rat in vivo. Results Using retroviral lineage analysis with the histochemical marker alkaline phosphatase, the percentage of cone and rod bipolar cells born on postnatal day 0 (P0, P4, and P6 were determined, based upon the well characterized morphology of these cells in the adult rat retina. In this in vivo experiment, we have demonstrated that cone bipolar genesis clearly precedes rod bipolar genesis. In addition, in the postnatal mouse retina, using a combination of tritiated-thymidine birthdating and immunohistochemistry to distinguish bipolar types, we have similarly found that cone bipolar genesis precedes rod bipolar genesis. The tritiated-thymidine birthdating studies also included quantification of the birth of all postnatally generated retinal cell types in the mouse. Conclusion Using two independent in vivo methodologies in rat and mouse retina, we have demonstrated that there are distinct waves of genesis of the two major bipolar cell types, with cone bipolar genesis preceding rod bipolar genesis. These waves of bipolar genesis correspond to the order of genesis of the presynaptic photoreceptor cell types.

  16. Phase Transition Phenomena in Ultra-Thin Ge2Sb2Te5 Film

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ting; LIU Bo; SONG Zhi-Tang; LIU Wei-Li; FENG Song-Lin; CHEN Bomy

    2005-01-01

    @@ We observe reversible phase transition phenomena in proto-type chalcogenide random access memory (C-RAM)devices adopting ultra-thin (12nm) Ge2Sb3 Te5 thin film. In this kind of proto-type device, the ultra-thin amorphous Ge2Sb2 Te5 thin film undergoes a crystallization process when a voltage is applied. The polycrystalline Ge2Sb3 Te5 remain unchanged when the voltage is below 0.6 V. A higher power is needed if the transition from polycrystalline to amorphous is expected. The re-amorphization process can be realized by applying a voltage higher than 0.7 V. The threshold voltage Vth and threshold electric field Eth of the transition from the polycrystalline state to the amorphous state in this proto-type device are ~0.7 V and ~ 5 × 105 V/cm, respectively. The programming voltage is significantly reduced compared to the values of C-RAM devices adopting a 200-nm-thick Ge2Sb2 Te5 inset.

  17. Phase-Change Memory Properties of Electrodeposited Ge-Sb-Te Thin Film

    Science.gov (United States)

    Huang, Ruomeng; Kissling, Gabriela P.; Jolleys, Andrew; Bartlett, Philip N.; Hector, Andrew L.; Levason, William; Reid, Gillian; De Groot, C. H. `Kees'

    2015-11-01

    We report the properties of a series of electrodeposited Ge-Sb-Te alloys with various compositions. It is shown that the Sb/Ge ratio can be varied in a controlled way by changing the electrodeposition potential. This method opens up the prospect of depositing Ge-Sb-Te super-lattice structures by electrodeposition. Material and electrical characteristics of various compositions have been investigated in detail, showing up to three orders of magnitude resistance ratio between the amorphous and crystalline states and endurance up to 1000 cycles.

  18. Terapia comportamental cognitiva para pessoas com transtorno bipolar Cognitive behavioral therapy for bipolar disorders

    OpenAIRE

    Francisco Lotufo Neto

    2004-01-01

    Descrição dos objetivos e principais técnicas da terapia comportamental cognitiva usadas para a psicoterapia das pessoas com transtorno bipolar.Objectives and main techniques of cognitive behavior therapy for the treatment of bipolar disorder patients are described.

  19. Terapia comportamental cognitiva para pessoas com transtorno bipolar Cognitive behavioral therapy for bipolar disorders

    Directory of Open Access Journals (Sweden)

    Francisco Lotufo Neto

    2004-10-01

    Full Text Available Descrição dos objetivos e principais técnicas da terapia comportamental cognitiva usadas para a psicoterapia das pessoas com transtorno bipolar.Objectives and main techniques of cognitive behavior therapy for the treatment of bipolar disorder patients are described.

  20. Subcortical Gray Matter Volume Abnormalities in Healthy Bipolar Offspring: Potential Neuroanatomical Risk Marker for Bipolar Disorder?

    Science.gov (United States)

    Ladouceur, Cecile D.; Almeida, Jorge R. C.; Birmaher, Boris; Axelson, David A.; Nau, Sharon; Kalas, Catherine; Monk, Kelly; Kupfer, David J.; Phillips, Mary L.

    2008-01-01

    A study is conducted to examine the extent to which bipolar disorder (BD) is associated with gray matter volume abnormalities in brain regions in healthy bipolar offspring relative to age-matched controls. Results show increased gray matter volume in the parahippocampus/hippocampus in healthy offspring at genetic risk for BD.

  1. Amorphous-silicon cell reliability testing

    Science.gov (United States)

    Lathrop, J. W.

    1985-01-01

    The work on reliability testing of solar cells is discussed. Results are given on initial temperature and humidity tests of amorphous silicon devices. Calibration and measurement procedures for amorphous and crystalline cells are given. Temperature stress levels are diagrammed.

  2. Investigation of Sb diffusion in amorphous silicon

    OpenAIRE

    Csik, A.; Langer, G A; Erdelyi, G.; Beke, D. L.; Erdelyi, Z.; Vad, K.

    2009-01-01

    Amorphous silicon materials and its alloys become extensively used in some technical applications involving large area of the microelectronic and optoelectronic devices. However, the amorphous-crystalline transition, segregation and diffusion processes still have numerous unanswered questions. In this work we study the Sb diffusion into an amorphous Si film by means of Secondary Neutral Mass Spectrometry (SNMS). Amorphous Si/Si1-xSbx/Si tri-layer samples with 5 at% antimony concentration were...

  3. Processamento cognitivo "Teoria da Mente" no transtorno bipolar Cognitive "Theory of Mind" processing in bipolar disorder

    Directory of Open Access Journals (Sweden)

    Hélio Anderson Tonelli

    2009-12-01

    Full Text Available OBJETIVO: O transtorno afetivo bipolar está associado ao comprometimento funcional persistente. Apesar de muitas pesquisas demonstrarem que bipolares podem apresentar déficits cognitivos, um número menor de trabalhos avaliou o papel de prejuízos no processamento cognitivo social, a Teoria da Mente (relacionado à capacidade de inferir estados mentais, no aparecimento de sintomas e complicações sociais em bipolares. O objetivo deste trabalho é o de revisar sistemática e criticamente a literatura sobre possíveis alterações do processamento Teoria da Mente no transtorno afetivo bipolar. MÉTODO: Foi realizada uma busca na base de dados Medline por trabalhos publicados em língua inglesa, alemã, espanhola ou portuguesa nos últimos 20 anos, utilizando a frase de busca "Bipolar Disorder"[Mesh] AND "Theory of Mind". Foram procurados por estudos clínicos envolvendo indivíduos bipolares e que empregaram uma ou mais tarefas cognitivas desenvolvidas para a avaliação de habilidades Teoria da Mente. Foram excluídos os relatos de caso e cartas ao editor. A busca inicial resultou em cinco artigos, sendo selecionados quatro. Outros quatro foram também selecionados a partir da leitura dos artigos acima. DISCUSSÃO: Os artigos selecionados avaliaram populações de bipolares adultos e pediátricos, incluindo indivíduos eutímicos, maníacos e deprimidos. A maioria dos trabalhos avaliados sugere que existam prejuízos no processamento Teoria da Mente em portadores de transtorno afetivo bipolar e que estes podem estar por trás dos sintomas e dos déficits funcionais do transtorno afetivo bipolar. CONCLUSÃO: Pesquisas futuras a respeito do tema em questão poderão esclarecer muito acerca do papel das alterações sociocognitivas no surgimento dos sintomas do transtorno afetivo bipolar, bem como ajudar no desenvolvimento de estratégias preventivas e terapêuticas do mesmo.OBJECTIVE: Bipolar disorder is associated to persistent functional

  4. Atomistic Models of Amorphous Semiconductors

    NARCIS (Netherlands)

    Jarolimek, K.

    2011-01-01

    Crystalline silicon is probably the best studied material, widely used by the semiconductor industry. The subject of this thesis is an intriguing form of this element namely amorphous silicon. It can contain a varying amount of hydrogen and is denoted as a-Si:H. It completely lacks the neat long ran

  5. Structural, thermal, and photoacoustic study of nanocrystalline Cr3Ge produced by mechanical alloying

    Science.gov (United States)

    Prates, P. B.; Maliska, A. M.; Ferreira, A. S.; Poffo, C. M.; Borges, Z. V.; de Lima, J. C.; de Biasi, R. S.

    2015-10-01

    A thermodynamic analysis of the Cr-Ge system suggested that it was possible to produce a nanostructured Cr3Ge phase by mechanical alloying. The same analysis showed that, due to low activation energies, Cr-poor crystalline and/or amorphous alloy could also be formed. In fact, when the experiment was performed, Cr11Ge19 and amorphous phases were present for small milling times. For milling times larger than 15 h these additional phases decomposed and only the nanostructured Cr3Ge phase remained up to the highest milling time used (32 h). From the differential scanning calorimetry measurements, the Avrami exponent n was obtained, indicating that the nucleation and growth of the nanostructured Cr3Ge phase may be restricted to one or two dimensions, where the Cr and Ge atoms diffuse along the surface and grain boundaries. In addition, contributions from three-dimensional diffusion with a constant nucleation rate may be present. The thermal diffusivity of the nanostructured Cr3Ge phase was determined by photoacoustic absorption spectroscopy measurements.

  6. Structural, thermal, and photoacoustic study of nanocrystalline Cr{sub 3}Ge produced by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Prates, P. B.; Maliska, A. M.; Ferreira, A. S. [Departamento de Engenharia Mecânica, Universidade Federal de Santa Catarina, Campus Universitário Trindade, S/N, C.P. 476, 88040-900 Florianópolis, Santa Catarina (Brazil); Poffo, C. M. [Universidade Federal de Santa Catarina, Campus de Araranguá, 88900-000 Araranguá, Santa Catarina (Brazil); Borges, Z. V. [Departamento de Física, Universidade Federal do Amazonas, 3000 Japiim, 69077-000 Manaus, Amazonas (Brazil); Lima, J. C. de, E-mail: fsc1jcd@fisica.ufsc.br [Departamento de Física, Universidade Federal de Santa Catarina, Campus Universitário Trindade, S/N, C.P. 476, 88040-900 Florianópolis, Santa Catarina (Brazil); Biasi, R. S. de [Seção de Engenharia Mecânica e de Materiais, Instituto Militar de Engenharia, 22290-270 Rio de Janeiro (Brazil)

    2015-10-21

    A thermodynamic analysis of the Cr-Ge system suggested that it was possible to produce a nanostructured Cr{sub 3}Ge phase by mechanical alloying. The same analysis showed that, due to low activation energies, Cr-poor crystalline and/or amorphous alloy could also be formed. In fact, when the experiment was performed, Cr{sub 11}Ge{sub 19} and amorphous phases were present for small milling times. For milling times larger than 15 h these additional phases decomposed and only the nanostructured Cr{sub 3}Ge phase remained up to the highest milling time used (32 h). From the differential scanning calorimetry measurements, the Avrami exponent n was obtained, indicating that the nucleation and growth of the nanostructured Cr{sub 3}Ge phase may be restricted to one or two dimensions, where the Cr and Ge atoms diffuse along the surface and grain boundaries. In addition, contributions from three-dimensional diffusion with a constant nucleation rate may be present. The thermal diffusivity of the nanostructured Cr{sub 3}Ge phase was determined by photoacoustic absorption spectroscopy measurements.

  7. Big data for bipolar disorder.

    Science.gov (United States)

    Monteith, Scott; Glenn, Tasha; Geddes, John; Whybrow, Peter C; Bauer, Michael

    2016-12-01

    The delivery of psychiatric care is changing with a new emphasis on integrated care, preventative measures, population health, and the biological basis of disease. Fundamental to this transformation are big data and advances in the ability to analyze these data. The impact of big data on the routine treatment of bipolar disorder today and in the near future is discussed, with examples that relate to health policy, the discovery of new associations, and the study of rare events. The primary sources of big data today are electronic medical records (EMR), claims, and registry data from providers and payers. In the near future, data created by patients from active monitoring, passive monitoring of Internet and smartphone activities, and from sensors may be integrated with the EMR. Diverse data sources from outside of medicine, such as government financial data, will be linked for research. Over the long term, genetic and imaging data will be integrated with the EMR, and there will be more emphasis on predictive models. Many technical challenges remain when analyzing big data that relates to size, heterogeneity, complexity, and unstructured text data in the EMR. Human judgement and subject matter expertise are critical parts of big data analysis, and the active participation of psychiatrists is needed throughout the analytical process.

  8. Big data for bipolar disorder.

    Science.gov (United States)

    Monteith, Scott; Glenn, Tasha; Geddes, John; Whybrow, Peter C; Bauer, Michael

    2016-12-01

    The delivery of psychiatric care is changing with a new emphasis on integrated care, preventative measures, population health, and the biological basis of disease. Fundamental to this transformation are big data and advances in the ability to analyze these data. The impact of big data on the routine treatment of bipolar disorder today and in the near future is discussed, with examples that relate to health policy, the discovery of new associations, and the study of rare events. The primary sources of big data today are electronic medical records (EMR), claims, and registry data from providers and payers. In the near future, data created by patients from active monitoring, passive monitoring of Internet and smartphone activities, and from sensors may be integrated with the EMR. Diverse data sources from outside of medicine, such as government financial data, will be linked for research. Over the long term, genetic and imaging data will be integrated with the EMR, and there will be more emphasis on predictive models. Many technical challenges remain when analyzing big data that relates to size, heterogeneity, complexity, and unstructured text data in the EMR. Human judgement and subject matter expertise are critical parts of big data analysis, and the active participation of psychiatrists is needed throughout the analytical process. PMID:27068058

  9. Roughening transition in nanoporous hydrogenated amorphous germanium: Roughness correlation to film stress

    Science.gov (United States)

    Carroll, M. S.; Verley, J. C.; Sheng, J. J.; Banks, J.

    2007-03-01

    Hydrogenated amorphous germanium (a-Ge:H) is a material of interest for optoelectronic applications such as solar cells and radiation detectors because of the material's potential to extend the wavelength sensitivity of hydrogenated amorphous silicon (a-Si:H). An increase in porosity is observed in amorphous germanium compared to a-Si :H, and this increase in porosity has been correlated with a degradation of the electrical performance. Improved understanding of the mechanisms of porous formation in a-Ge :H films is therefore desirable in order to better control it. In this paper we describe a correlation between film stress and surface roughness, which evolves with increasing thickness of a-Ge :H. A roughening transition from planar two-dimensional growth to three-dimensional growth at a critical thickness less than 800Å results in a network of needlelike nanotrench cavities which stretch from the transition thickness to the surface in films up to 4000Å thick. Surface roughness measurements by atomic force microscope and transmission electron microscopy indicate that the transition is abrupt and that the roughness increases linearly after the transition thickness. The roughening transition thickness is, furthermore, found to correlate with the maxima of the integrated compressive stress. The compressive stress is reduced after this transition thickness due to the incorporation of nanovoids into the film that introduce tensile stress as the islands coalesce together. The roughening transition behavior is similar to that found in a general class of Volmer-Weber mode thin film deposition (e.g., Cu, Ag, and nonhydrogenated amorphous silicon), which offers additional insight into the underlying mechanisms of the stress and roughening in these a-Ge :H films. The suppression of the roughening transition by changing the kinetics of the deposition rates (e.g., slowing the deposition rate with a weak sputtering bias) is also observed and discussed.

  10. Hydrogenated Amorphous Silicon Germanium Active Layer for Top Cell of a Multi Junction Cell Structure.

    Science.gov (United States)

    Cho, Jaehyun; Iftiquar, S M; Kim, Minbum; Park, Jinjoo; Jung, Junhee; Kim, Jiwoong; Yi, Junsin

    2016-05-01

    Intrinsic hydrogenated amorphous silicon-germanium (a-SiGe:H) alloy is generally used in the bottom cell because of its low band gap. The a-SiGe:H has a higher photo conductivity in comparison to the a-Si:H; thus, it is expected that the a-SiGe:H can show better short circuit current density than that of the a-Si:H based solar cell. Therefore, we optimized a-SiGe:H active layer that can be a suitable choice for the front cell of a multi junction.solar cell. Furthermore, we carried out a comparative study of the solar cells that have a-SiGe:H and a-Si:H as respective active layers. The a-SiGe:H based solar cells show higher short circuit current density, while the a-Si:H based cells show higheropen circuit voltage. The current-voltage characteristics of these cells are as follows: (a) V(oc) = 770 mV, J(sc) = 15.0 mA/cm2, FF = 64.5%, and η = 7.47% for a-SiGe:H based cell; and (b) V(oc) = 826 mV, J(sc) = 13.63 mA/cm2, FF = 72.0%, and η = 8.1% for a-Si:H based cell. PMID:27483837

  11. SiGeHBTs on Bonded SOI Incorporating Buried Silicide Layers

    OpenAIRE

    Bain, M.; El Mubarek, H A; Bonar, J. M.; Wang, Y.; Buiu, O.; Gamble, H.; Armstrong, B M; Hemment, P L; Hall, S.; Ashburn, P.

    2005-01-01

    A technology is described for fabricating SiGe hetero-junction bipolar transistors (HBTs) on wafer-bonded silicon-on-insulator (SOI) substrates that incorporate buried tungsten silicide layers for collector resistance reduction or buried groundplanes for crosstalk suppression. The physical structure of the devices is characterized using cross section transmission electron microscopy, and the electrical properties of the buried tungsten silicide layer are characterized using sheet resistance m...

  12. SiGe HBTs on bonded SOI incorporating buried silicide layers

    OpenAIRE

    Bain, M.; El Mubarek, A. W.; Bonar, J. M.; Wang, Y.; Buiu, O.; Gamble, H.; Armstrong, B M; Hemment, P. L. F.; Hall, Steven; Ashburn, Peter

    2005-01-01

    A technology is described for fabricating SiGe heterojunction bipolar transistors (HBTs) on wafer-bonded silicon-on-insulator (SOI) substrates that incorporate buried tungsten silicide layers for collector resistance reduction or buried groundplanes for crosstalk suppression. The physical structure of the devices is characterized using cross section transmission electron microscopy, and the electrical properties of the buried tungsten silicide layer are characterized using sheet resistance me...

  13. SiGe BiCMOS RF ICs and Components for High Speed Wireless Data Networks

    OpenAIRE

    Svitek, Richard M

    2005-01-01

    The advent of high-fT silicon CMOS/BiCMOS technologies has led to a dramatic upsurge in the research and development of radio and microwave frequency integrated circuits (ICs) in silicon. The integration of silicon-germanium heterojunction bipolar transistors (SiGe HBTs) into established "digital" CMOS processes has provided analog performance in silicon that is not only competitive with III-V compound-semiconductor technologies, but is also potentially lower in cost. Combined with improvem...

  14. Structure and Spatial Distribution of Ge Nanocrystals Subjected to Fast Neutron Irradiation

    Directory of Open Access Journals (Sweden)

    Alexander N. Ionov

    2011-07-01

    Full Text Available The influence of fast neutron irradiation on the structure and spatial distribution of Ge nanocrystals (NC embedded in an amorphous SiO2 matrix has been studied. The investigation was conducted by means of laser Raman Scattering (RS, High Resolution Transmission Electron Microscopy (HR-TEM and X-ray photoelectron spectroscopy (XPS. The irradiation of Ge- NC samples by a high dose of fast neutrons lead to a partial destruction of the nanocrystals. Full reconstruction of crystallinity was achieved after annealing the radiation damage at 8000C, which resulted in full restoration of the RS spectrum. HR-TEM images show, however, that the spatial distributions of Ge-NC changed as a result of irradiation and annealing. A sharp decrease in NC distribution towards the SiO2 surface has been observed. This was accompanied by XPS detection of Ge oxides and elemental Ge within both the surface and subsurface region.

  15. Bipolar batteries based on Ebonex ® technology

    Science.gov (United States)

    Loyns, A. C.; Hill, A.; Ellis, K. G.; Partington, T. J.; Hill, J. M.

    Continuing work by Atraverda on the production of a composite-laminate form of the Ebonex ® material, that can be cheaply formulated and manufactured to form substrate plates for bipolar lead-acid batteries, is described. Ebonex ® is the registered trade name of a range of titanium suboxide ceramic materials, typically Ti 4O 7 and Ti 5O 9, which combine electrical conductivity with high corrosion and oxidation resistance. Details of the structure of the composite, battery construction techniques and methods for filling and forming of batteries are discussed. In addition, lifetime and performance data obtained by Atraverda from laboratory bipolar lead-acid batteries and cells are presented. Battery production techniques for both conventional monopolar and bipolar batteries are reviewed. The findings indicate that substantial time and cost savings may be realised in the manufacture of bipolar batteries in comparison to conventional designs. This is due to the fewer processing steps required and more efficient formation. The results indicate that the use of Ebonex ® composite material as a bipolar substrate will provide lightweight and durable high-voltage lead-acid batteries suitable for a wide range of applications including advanced automotive, stationary power and portable equipment.

  16. The role of sleep in bipolar disorder.

    Science.gov (United States)

    Gold, Alexandra K; Sylvia, Louisa G

    2016-01-01

    Bipolar disorder is a serious mental illness characterized by alternating periods of elevated and depressed mood. Sleep disturbances in bipolar disorder are present during all stages of the condition and exert a negative impact on overall course, quality of life, and treatment outcomes. We examine the partnership between circadian system (process C) functioning and sleep-wake homeostasis (process S) on optimal sleep functioning and explore the role of disruptions in both systems on sleep disturbances in bipolar disorder. A convergence of evidence suggests that sleep problems in bipolar disorder result from dysregulation across both process C and process S systems. Biomarkers of depressive episodes include heightened fragmentation of rapid eye movement (REM) sleep, reduced REM latency, increased REM density, and a greater percentage of awakenings, while biomarkers of manic episodes include reduced REM latency, greater percentage of stage I sleep, increased REM density, discontinuous sleep patterns, shortened total sleep time, and a greater time awake in bed. These findings highlight the importance of targeting novel treatments for sleep disturbance in bipolar disorder. PMID:27418862

  17. QUALITY OF LIFE IN BIPOLAR DISORDER

    Directory of Open Access Journals (Sweden)

    Nieznańska, Anna

    2014-12-01

    Full Text Available Background: Among the consequences of bipolar disorder there i s a decreased quality of life, including the deterioration of patients’ social functioning. Material: The paper contains an analysis of 24 major publica tions from the years 2009 to 2014, including 17 related to the assessment of quality of life and 7 articles on the bipolar patients’ social functioning. Results: There were selected 8 factors which are related with the assessment of the quality of life of persons with a diagnosis of bipolar disorder: the presence of depressive symptoms, substance use, sleep deficit, religious activity and social support, internalized stigma, suicide attempts in the past, the perception of emotions and impulsivity. It was defined that social functioning of bipolar patients is dependent on the emotional state of patients, and in particular the presence of depressive symptoms. It is dependent also on patients’ cognitive performance and internalized stigma. Conclusions: Assistance in mastering the first symptoms of a depressive phase can help bipolar patients in their smooth social functioning and quality of life. Taking into account the implementation of appropriate therapy with cognitive exercise and which is aimed at reducing internalized stigma, may contribute to improving the quality of life and improve the patients’ social functioning.

  18. The role of sleep in bipolar disorder

    Science.gov (United States)

    Gold, Alexandra K; Sylvia, Louisa G

    2016-01-01

    Bipolar disorder is a serious mental illness characterized by alternating periods of elevated and depressed mood. Sleep disturbances in bipolar disorder are present during all stages of the condition and exert a negative impact on overall course, quality of life, and treatment outcomes. We examine the partnership between circadian system (process C) functioning and sleep–wake homeostasis (process S) on optimal sleep functioning and explore the role of disruptions in both systems on sleep disturbances in bipolar disorder. A convergence of evidence suggests that sleep problems in bipolar disorder result from dysregulation across both process C and process S systems. Biomarkers of depressive episodes include heightened fragmentation of rapid eye movement (REM) sleep, reduced REM latency, increased REM density, and a greater percentage of awakenings, while biomarkers of manic episodes include reduced REM latency, greater percentage of stage I sleep, increased REM density, discontinuous sleep patterns, shortened total sleep time, and a greater time awake in bed. These findings highlight the importance of targeting novel treatments for sleep disturbance in bipolar disorder. PMID:27418862

  19. [Pseudocholinesterase activity in type 1 bipolar patients].

    Science.gov (United States)

    Ezzaher, Asma; Haj Mouhamed, Dhouha; Mechri, Anwar; Neffati, Fadoua; Douki, Wahiba; Gaha, Lotfi; Najjar, Mohamed Fadhel

    2012-01-01

    This study aims to investigate the variation of pseudocholinesterase activity (BuChE) in bipolar patients and to explore its relation to the clinical and therapeutic characteristics of this disease. Our study included 105 patients with bipolar disorder and 100 control subjects aged 38.7 ± 12.2 and 36.4 ± 15.7 y, respectively. BuChE was determined by kinetic methods on Cobas Integra 400 plus™. Compared with controls, patients had a significantly higher pseudocholinesterase activity. Moreover, this increase was significantly associated (p = 0.001) with bipolar disorder with sensibility of 58% and specificity of 62% at threshold of 7392 IU/L. There was no significant change in pseudocholinesterase activity in relation to illness episodes and treatment, whereas the lowest values of this activity were seen in euthymic patients and those taking psychotics. Therefore, this activity is a real interest in the biological monitoring of patients as a risk factor for neurodegenerative diseases associated with bipolar disorder. But it would be most useful to evaluate their interest as a predictor of bipolar disorder in patients at risk. PMID:22294139

  20. Ion-beam induced structure modifications in amorphous germanium; Ionenstrahlinduzierte Strukturmodifikationen in amorphem Germanium

    Energy Technology Data Exchange (ETDEWEB)

    Steinbach, Tobias

    2012-05-03

    Object of the present thesis was the systematic study of ion-beam induced structure modifications in amorphous germanium (a-Ge) layers due to low- (LEI) and high-energetic (SHI) ion irradiation. The LEI irradiation of crystalline Ge (c-Ge) effects because the dominating nuclear scattering of the ions on the solid-state atoms the formation of a homogeneous a-Ge Layer. Directly on the surface for fluences of two orders of magnitude above the amorphization fluence the formation of stable cavities independently on the irradiation conditions was observed. For the first time for the ion-beam induced cavity formation respectively for the steady expansion of the porous layer forming with growing fluence a linear dependence on the energy {epsilon}{sub n} deposed in nuclear processes was detected. Furthermore the formation of buried cavities was observed, which shows a dependence on the type of ions. While in the c-Ge samples in the range of the high electronic energy deposition no radiation defects, cavities, or plastic deformations were observed, the high electronic energy transfer in the 3.1 {mu}m thick pre-amorphized a-Ge surface layers leads to the formation of randomly distributed cavities. Basing on the linear connection between cavity-induced vertical volume expansion and the fluence determined for different energy transfers for the first time a material-specific threshold value of {epsilon}{sub e}{sup HRF}=(10.5{+-}1.0) kev nm{sup -1} was determined, above which the ion-beam induced cavity formation in a-Ge sets on. The anisotropic plastic deformation of th a-Ge layer superposed at inclined SHI irradiation on the cavity formation was very well described by an equation derived from the viscoelastic Maxwell model, but modified under regardment of the experimental results. The positive deformation yields determined thereby exhibit above a threshold value for the ion-beam induced plastic deformation {epsilon}{sub e}{sup S{sub a}}=(12{+-}2) keV nm{sup -1} for the first

  1. Cytokines in bipolar disorder vs. healthy control subjects

    DEFF Research Database (Denmark)

    Munkholm, Klaus; Braüner, Julie Vestergaard; Kessing, Lars Vedel;

    2013-01-01

    Bipolar disorder may be associated with peripheral immune system dysfunction; however, results in individual studies are conflicting. Our aim was to systematically review evidence of peripheral cytokine alterations in bipolar disorder integrating findings from various affective states....

  2. Assessment of subjective and objective cognitive function in bipolar disorder

    DEFF Research Database (Denmark)

    Demant, Kirsa M; Vinberg, Maj; Kessing, Lars V;

    2015-01-01

    Cognitive dysfunction is prevalent in bipolar disorder (BD). However, the evidence regarding the association between subjective cognitive complaints, objective cognitive performance and psychosocial function is sparse and inconsistent. Seventy seven patients with bipolar disorder who presented...

  3. Application of Bipolar Fuzzy Sets in Graph Structures

    Directory of Open Access Journals (Sweden)

    Muhammad Akram

    2016-01-01

    Full Text Available A graph structure is a useful tool in solving the combinatorial problems in different areas of computer science and computational intelligence systems. In this paper, we apply the concept of bipolar fuzzy sets to graph structures. We introduce certain notions, including bipolar fuzzy graph structure (BFGS, strong bipolar fuzzy graph structure, bipolar fuzzy Ni-cycle, bipolar fuzzy Ni-tree, bipolar fuzzy Ni-cut vertex, and bipolar fuzzy Ni-bridge, and illustrate these notions by several examples. We study ϕ-complement, self-complement, strong self-complement, and totally strong self-complement in bipolar fuzzy graph structures, and we investigate some of their interesting properties.

  4. Anticonvulsant Drugs for Nerve Pain, Bipolar Disorder and Fibromyalgia

    Science.gov (United States)

    Anticonvulsant Drugs for Nerve Pain, Bipolar Disorder &Fibromyalgia: Choosing What’sRight for You What are anticonvulsant drugs? Anticonvulsants are drugs used to treat seizures. They are also used to treat bipolar ...

  5. Lithium Beats Newer Meds for Bipolar Disorder, Study Finds

    Science.gov (United States)

    ... for Treatment and Research of Bipolar Disorder at Zucker Hillside Hospital in Glen Oaks, N.Y., and ... Center for Treatment and Research of Bipolar Disorder, Zucker Hillside Hospital, Glen Oaks, N.Y.; May 11, ...

  6. Kids with Bipolar Disorder More Likely to Abuse Drugs, Alcohol

    Science.gov (United States)

    ... html Kids With Bipolar Disorder More Likely to Abuse Drugs, Alcohol: Study And those who also have conduct disorder ... with bipolar disorder, the risk that they will abuse alcohol and drugs may increase as they get older, ...

  7. Immune activation by casein dietary antigens in bipolar disorder

    NARCIS (Netherlands)

    Severance, E.G.; Dupont, D.; Dickerson, F.B.; Stallings, C.R.; Origoni, A.E.; Krivogorsky, B.; Yang, S.; Haasnoot, W.; Yolken, R.H.

    2010-01-01

    Objectives: Inflammation and other immune processes are increasingly linked to psychiatric diseases. Antigenic triggers specific to bipolar disorder are not yet defined. We tested whether antibodies to bovine milk caseins were associated with bipolar disorder, and whether patients recognized differe

  8. A minimum thermodynamic model for the bipolar seesaw

    DEFF Research Database (Denmark)

    Stocker, Thomas F.; Johnsen, Sigfus Johann

    2003-01-01

    Bipolar seesaw, synchronization of Antarctic and Greenland ice cores, Dansgaard-Oeschger events, north-south connection......Bipolar seesaw, synchronization of Antarctic and Greenland ice cores, Dansgaard-Oeschger events, north-south connection...

  9. Differences between Depression Episodes of Bipolar Disorder I and II

    Directory of Open Access Journals (Sweden)

    Leman Inanc

    2013-09-01

    Full Text Available In 1975 Fieve and Dunner made the distinction between hypomania and mania as hypomania does not usually cause social and occupational impair-ment and hospitalization is not needed, moreover patients do not experience psychosis. Bipolar disorder type I is defined by the presence of manic and depressive episodes and differs from Bipolar disorder type II characterized with hipomanic and depressive episodes. Bipolar disorder type I and II do not differ in their depressive episodes. It is still point of contention whether bipolar type II is a variant of bipolar disorder type I or is positioned on the spectrum between bipolar type I and unipolar disorder. Even there are some similarities in characteristics of depressive episodes and outcome features of different bipolar disorder subtypes, there are differences that can be useful in differential diagnosis and treatment. This paper aims to focus on those differences between bipolar disorder type I and II.

  10. Immunocytochemical Evidence that Monkey Rod Bipolar Cells Use GABA

    OpenAIRE

    Lassová, Luisa; Fina, Marie; Sulaiman, Pyroja; Vard, Noga

    2010-01-01

    Certain bipolar cells in most species immunostain for GABA or its synthesizing enzyme, GAD. However it is unknown whether they actually release GABA, and if so, from which cellular compartment, and by what release mechanism. We investigated these questions in monkey retina where rod bipolar cells immunostain for GABA. We found that rod bipolar cells immunostain for one isoform of GAD, GAD65, in their somas, dendrites, and axon terminals. Near the fovea, the somatic stain of rod bipolar cells ...

  11. Experience of Subjective Symptoms in Euthymic Patients with Bipolar Disorder

    OpenAIRE

    Joe, Soohyun; Joo,YeonHo; Kim, Seongyoon

    2008-01-01

    Bipolar patients often experience subjective symptoms even if they do not have active psychotic symptoms in their euthymic state. Most studies about subjective symptoms are conducted in schizophrenia, and there are few studies involving bipolar patients. We examined the nature of the subjective symptoms of bipolar patients in their euthymic state, and we also compared it to that of schizophrenia and normal control. Thirty bipolar patients, 25 patients with schizophrenia, and 21 normal control...

  12. A Review of MR Spectroscopy Studies of Pediatric Bipolar Disorder

    OpenAIRE

    Kondo, D.G.; Hellem, T.L.; Shi, X.-F.; Sung, Y.H.; Prescot, A.P.; Kim, T.S.; Huber, R.S.; Forrest, L.N.; Renshaw, P.F.

    2014-01-01

    Pediatric bipolar disorder is a severe mental illness whose pathophysiology is poorly understood and for which there is an urgent need for improved diagnosis and treatment. MR spectroscopy is a neuroimaging method capable of in vivo measurement of neurochemicals relevant to bipolar disorder neurobiology. MR spectroscopy studies of adult bipolar disorder provide consistent evidence for alterations in the glutamate system and mitochondrial function. In bipolar disorder, these 2 phenomena may be...

  13. Rumination in bipolar disorder: evidence for an unquiet mind

    OpenAIRE

    Ghaznavi Sharmin; Deckersbach Thilo

    2012-01-01

    Abstract Depression in bipolar disorder has long been thought to be a state characterized by mental inactivity. However, recent research demonstrates that patients with bipolar disorder engage in rumination, a form of self-focused repetitive cognitive activity, in depressed as well as in manic states. While rumination has long been associated with depressed states in major depressive disorder, the finding that patients with bipolar disorder ruminate in manic states is unique to bipolar disord...

  14. Ferromagnetism modulation by phase change in Mn-doped GeTe chalcogenide magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Adam, Adam Abdalla Elbashir [Huazhong University of Science and Technology, School of Optical and Electronic Information, Wuhan (China); Wuhan National Laboratory for Optoelectronics, Wuhan (China); Alneelain University, Faculty of Science and Technology, Khartoum (Sudan); Cheng, Xiaomin; Guan, Xiawei; Miao, Xiangshui [Huazhong University of Science and Technology, School of Optical and Electronic Information, Wuhan (China); Wuhan National Laboratory for Optoelectronics, Wuhan (China)

    2014-12-15

    In this work, an effective method to modulate the ferromagnetic properties of Mn-doped GeTe chalcogenide-based phase change materials is presented. The microstructure of the phase change magnetic material Ge{sub 1-x} Mn{sub x} Te thin films was studied. The X-ray diffraction results demonstrate that the as-deposited films are amorphous, and the crystalline films are formed after annealing at 350 C for 10 min. Crystallographic structure investigation shows the existence of some secondary magnetic phases. The lattice parameters of Ge{sub 1-x} Mn{sub x} Te (x = 0.04, 0.12 and 0.15) thin films are found to be slightly different with changes of Mn compositions. The structural analysis clearly indicates that all the films have a stable rhombohedral face-centered cubic polycrystalline structure. The magnetic properties of the amorphous and crystalline Ge{sub 0.96}Mn{sub 0.04}Te were investigated. The measurements of magnetization (M) as a function of the magnetic field (H) show that both amorphous and crystalline phases of Ge{sub 0.96}Mn{sub 0.04}Te thin film are ferromagnetic and there is drastic variation between amorphous and crystalline states. The temperature (T) dependence of magnetizations at zero field cooling (ZFC) and field cooling (FC) conditions of the crystalline Ge{sub 0.96}Mn{sub 0.04}Te thin film under different applied magnetic fields were performed. The measured data at 100 and 300 Oe applied magnetic fields show large bifurcations in the ZFC and FC curves while on the 5,000 Oe magnetic field there is no deviation. (orig.)

  15. Paired structures and bipolar knowledge representation

    DEFF Research Database (Denmark)

    Montero, Javier; Bustince, Humberto; Franco, Camilo;

    In this strictly positional paper we propose a general approach to bipolar knowledge representation, where the meaning of concepts can be modelled by examining their decomposition into opposite and neutral categories. In particular, it is the semantic relationship between the opposite categories...... and at the same time the type of neutrality rising in between opposites. Based on this first level of bipolar knowledge representation, paired structures in fact offer the means to characterize a specific bipolar valuation scale depending on the meaning of the concept that has to be verified. In this sense...... which suggests the emergence of a paired structure and its associated type of neutrality, being there three general types of neutral categories, namely indeterminacy, ambivalence and conflict. Hence, the key issue consists in identifying the semantic opposition characterizing the meaning of concepts...

  16. Plain carbon steel bipolar plates for PEMFC

    Institute of Scientific and Technical Information of China (English)

    WANG Jianli; SUN Juncai; TIAN Rujin; XU Jing

    2006-01-01

    Bipolar plates are a multifunctional component of PEMFC. Comparing with the machined graphite and stainless steels, the plain carbon steel is a very cheap commercial metal material. In this paper, the possibility of applying the plain carbon steels in the bipolar plate for PEMFC was exploited. In order to improve the corrosion resistance of the low carbon steel in the PEMFCs' environments,two surface modification processes was developed and then the electrochemical performances and interfacial contact resistance (ICR) of the surface modified plate of plain carbon steel were investigated. The results show that the surface modified steel plates have good corrosion resistance and relatively low contact resistance, and it may be a candidate material as bipolar plate of PEMFC.

  17. Family Functioning and the Course of Adolescent Bipolar Disorder

    Science.gov (United States)

    Sullivan, Aimee E.; Judd, Charles M.; Axelson, David A.; Miklowitz, David J.

    2012-01-01

    The symptoms of bipolar disorder affect and are affected by the functioning of family environments. Little is known, however, about the stability of family functioning among youth with bipolar disorder as they cycle in and out of mood episodes. This study examined family functioning and its relationship to symptoms of adolescent bipolar disorder,…

  18. Amorphous metal based nanoelectromechanical switch

    KAUST Repository

    Mayet, Abdulilah M.

    2013-04-01

    Nanoelectromechanical (NEM) switch is an interesting ultra-low power option which can operate in the harsh environment and can be a complementary element in complex digital circuitry. Although significant advancement is happening in this field, report on ultra-low voltage (pull-in) switch which offers high switching speed and area efficiency is yet to be made. One key challenge to achieve such characteristics is to fabricate nano-scale switches with amorphous metal so the shape and dimensional integrity are maintained to achieve the desired performance. Therefore, we report a tungsten alloy based amorphous metal with fabrication process development of laterally actuated dual gated NEM switches with 100 nm width and 200 nm air-gap to result in <5 volts of actuation voltage (Vpull-in). © 2013 IEEE.

  19. Processamento cognitivo "Teoria da Mente" no transtorno bipolar Cognitive "Theory of Mind" processing in bipolar disorder

    OpenAIRE

    Hélio Anderson Tonelli

    2009-01-01

    OBJETIVO: O transtorno afetivo bipolar está associado ao comprometimento funcional persistente. Apesar de muitas pesquisas demonstrarem que bipolares podem apresentar déficits cognitivos, um número menor de trabalhos avaliou o papel de prejuízos no processamento cognitivo social, a Teoria da Mente (relacionado à capacidade de inferir estados mentais), no aparecimento de sintomas e complicações sociais em bipolares. O objetivo deste trabalho é o de revisar sistemática e criticamente a literatu...

  20. Transtorno bipolar do humor e gênero Bipolar affective disorder and gender

    OpenAIRE

    Rodrigo da Silva Dias; Florence Kerr-Corrêa; Ricardo Cezar Torresan; Carlos Henrique R. dos Santos

    2006-01-01

    Embora o transtorno bipolar (TB) ocorra quase igualmente em ambos os sexos, a fenomenologia e o curso da doença diferem no homem e na mulher. No entanto, há evidências de que mulheres bipolares, mais que os homens, apresentariam início mais tardio (em especial na quinta década de vida), ciclagem rápida, mais episódios depressivos, mais mania disfórica que eufórica, estados mistos e evolução do tipo bipolar II, ainda que os achados nem sempre sejam consistentes. Embora o risco de comorbidades ...

  1. Amorphous silicon based betavoltaic devices

    OpenAIRE

    Wyrsch, N; Riesen, Y.; Franco, A; S. Dunand; Kind, H.; Schneider, S.; Ballif, C.

    2013-01-01

    Hydrogenated amorphous silicon betavoltaic devices are studied both by simulation and experimentally. Devices exhibiting a power density of 0.1 μW/cm2 upon Tritium exposure were fabricated. However, a significant degradation of the performance is taking place, especially during the first hours of the exposure. The degradation behavior differs from sample to sample as well as from published results in the literature. Comparisons with degradation from beta particles suggest an effect of tritium...

  2. Structural study of Ge/GaAs thin films

    Science.gov (United States)

    Lazarov, V. K.; Lari, L.; Lytvyn, P. M.; Kholevchuk, V. V.; Mitin, V. F.

    2012-07-01

    Ge/GaAs heterostructure research is largely motivated by the application of this material in solar cells, metal-oxide-semiconductor field-effect transistors, mm-wave mixer diodes, temperature sensors and photodetectors. Therefore, understanding of how the properties of Ge/GaAs heterostructure depend on its preparation (growth) is of importance for various high-efficiency devices. In this work, by using thermal Ge evaporation on GaAs(100), we studied structural properties of these films as a function of the deposition rate. Film grains size and morphology show strong dependence of the deposition rate. Low deposition rates results in films with large crystal grains and rough surface. At high deposition rates films become flatter and their crystal grains size decreases, while at very high deposition rates films become amorphous. Cross-sectional TEM of the films show that the Ge films are granular single crystal epitaxially grown on GaAs. The Ge/GaAs interface is atomically abrupt and free from misfit dislocations. Stacking faults along the [111] directions that originate at the interface were also observed. Finally by using the Kelvin probe microscopy we show that work function changes are related to the grain structure of the film.

  3. Climatic factors and bipolar affective disorder

    DEFF Research Database (Denmark)

    Christensen, Ellen Margrethe; Larsen, Jens Knud; Gjerris, Annette;

    2008-01-01

    . A group of patients with at least three previous hospitalizations for bipolar disorder was examined every 3 months for up to 3 years. At each examination an evaluation of the affective phase was made according to the Hamilton Depression Scale (HAM-D(17)), and the Bech-Rafaelsen Mania Rating Scale (MAS......). In the same period, daily recordings from the Danish Meteorological Institute were received. We found no correlations between onset of bipolar episodes [defined as MAS score of 11 or more (mania) and as HAM-D(17) score of 12 or more (depression)] and any meteorological parameters. We found a statistical...

  4. [Bipolar disorders and self-stigma].

    Science.gov (United States)

    Richard-Lepouriel, H

    2015-09-16

    Despite wide media coverage in recent years, the stigmatization of people with bipolar disorder still exists. Bipolar people also have their own tendency to self-stigmatize that is to integrate their beliefs, prejudices and stigmatizing behaviors. The consequences are important: shame, guilt, withdrawal and renunciation to lead one's own life according to personal values increasing therefore the risk of mood relapses. Self-stigma is rarely assessed in clinical practice and few strategies have been designed to face them efficiently. Recognizing self-stigmatizing beliefs and challenging them are the first steps of this vast endeavour. PMID:26591079

  5. Bipolar effects in unipolar junctionless transistors

    Science.gov (United States)

    Parihar, Mukta Singh; Ghosh, Dipankar; Armstrong, G. Alastair; Yu, Ran; Razavi, Pedram; Kranti, Abhinav

    2012-08-01

    In this work, we analyze hysteresis and bipolar effects in unipolar junctionless transistors. A change in subthreshold drain current by 5 orders of magnitude is demonstrated at a drain voltage of 2.25 V in silicon junctionless transistor. Contrary to the conventional theory, increasing gate oxide thickness results in (i) a reduction of subthreshold slope (S-slope) and (ii) an increase in drain current, due to bipolar effects. The high sensitivity to film thickness in junctionless devices will be most crucial factor in achieving steep transition from ON to OFF state.

  6. Rumination in bipolar disorder: a systematic review

    OpenAIRE

    Érico de M. Silveira Jr.; Marcia Kauer-Sant'Anna

    2015-01-01

    Objective:To conduct a systematic review of the literature about the symptom of rumination in bipolar disorder (BD).Methods:We searched the MEDLINE (PubMed), ISI Web of Knowledge, PsycINFO, and SciELO databases using the descriptors “rumination” and “bipolar disorder” and no time limits. This strategy yielded 105 references, of which 74 were selected. Inclusion criteria were studies involving patients with BD and the use of at least one validated scale for the assessment of rumination. Review...

  7. Low Specific Contact Resistivity to n-Ge and Well-Behaved Ge n+/p Diode Achieved by Implantation and Excimer Laser Annealing

    Science.gov (United States)

    Wang, Chen; Li, Cheng; Huang, Shihao; Lu, Weifang; Yan, Guangming; Lin, Guangyang; Wei, Jiangbin; Huang, Wei; Lai, Hongkai; Chen, Songyan

    2013-10-01

    Excimer laser annealing of phosphorus-implanted p-type germanium substrate with various laser energy densities for n+/p junction were investigated. The effects of laser energy density on the redistribution of dopant, surface morphology, and recrystallization of the amorphous Ge induced by ion implantation were characterized. A low specific contact resistivity of 1.61×10-6 Ω·cm2 was achieved from Al/n-Ge ohmic contact, in which phosphorus-implanted Ge was annealed at a laser energy density of 250 mJ/cm2, tailoring a small phosphorus diffusion length, high activation level, and low dopant loss. A well-behaved Ge n+/p diode with a rectification ratio up to 1.99×105 was demonstrated.

  8. Three times more days depressed than manic or hypomanic in both bipolar I and bipolar II disorder

    NARCIS (Netherlands)

    Kupka, Ralph W.; Altshuler, Lori L.; Nolen, Willem A.; Suppes, Trisha; Luckenbaugh, David A.; Leverich, Gabriele S.; Frye, Mark A.; Keck, Paul E.; McElroy, Susan L.; Grunze, Heinz; Post, Robert M.

    2007-01-01

    Objectives: To assess the proportion of time spent in mania, depression and euthymia in a large cohort of bipolar subjects studied longitudinally, and to investigate depression/mania ratios in patients with bipolar I versus bipolar II disorder. Methods: Clinician-adjusted self-ratings of mood were c

  9. A report on older-age bipolar disorder from the International Society for Bipolar Disorders Task Force

    DEFF Research Database (Denmark)

    Sajatovic, Martha; Strejilevich, Sergio A; Gildengers, Ariel G;

    2015-01-01

    OBJECTIVES: In the coming generation, older adults with bipolar disorder (BD) will increase in absolute numbers as well as proportion of the general population. This is the first report of the International Society for Bipolar Disorder (ISBD) Task Force on Older-Age Bipolar Disorder (OABD). METHO...

  10. Sleep disturbances in pediatric bipolar disorder: A comparison between Bipolar I and Bipolar NOS

    Directory of Open Access Journals (Sweden)

    Argelinda eBaroni

    2012-03-01

    Full Text Available Introduction: The diagnosis of Bipolar Disorder (BD in youths has been controversial, especially for the subtype BD Not Otherwise Specified (BD-NOS. In spite of growing evidence that sleep is a core feature of BD, few studies characterize and compare sleep disturbances in youth with BD type I (BD-I and BD-NOS. Sleep disturbances are frequently reported in clinical descriptions of children and adolescents with BD, however the reporting of the frequency and characteristics of sleep symptoms in youth with BD NOS and BD I during episodes remain poor. This study compares symptom of sleep disturbance as occurring in manic and depressive episodes in BD I and BD NOS youth using KSADS-PL interview data. The study also addresses whether symptoms of sleep disturbance vary in different age groups. Material and Methods: The sample consisted of 70 children and adolescent outpatients at an urban specialty clinic (42M/28F, 10.8±3.6 years old including 24 BP-I and 46 BP-NOS assessed using K-SADS-PL-parent interview. Results: Sleep disturbances including insomnia and decreased need for sleep were reported by 84.3% of the sample. Enuresis was diagnosed in 27% of sample. There were no significant differences in frequency of sleep symptoms between BD-I and BD-NOS. Regardless of BD subtype, current functioning was negatively correlated with decreased need for sleep but not insomnia, and regardless of BD subtype. Conclusion: The majority of youth with BD presents with sleep symptoms during mood episodes. BD NOS presents with the same proportion of sleep symptoms as BD I in our sample.

  11. Role of Activation Energy in Resistance Drift of Amorphous Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Martin eWimmer

    2014-12-01

    Full Text Available The time evolution of the resistance of amorphous thin films of the phase change materials Ge2Sb2Te5, GeTe and AgIn-Sb2Te is measured during annealing at T=80°C. The annealing process is interrupted by several fast temperature dips to determine the changing temperature dependence of the resistance. This procedure enables us to identify to what extent the resistance increase over time can be traced back to an increase in activation energy EA or to a rise of the prefactor R*. We observe that, depending on the material, the dominating contribution to the increase in resistance during annealing can be either a change in activation energy (Ge2Sb2Te5 or a change in prefactor (AgIn-Sb2Te. In the case of GeTe, both contribute about equally. We conclude that any phenomenological model for the resistance drift in amorphous phase change materials that is based on the increase of one parameter alone (e.g. the activation energy cannot claim general validity.

  12. Long-range structural correlations in amorphous ternary In-based oxides

    Science.gov (United States)

    Khanal, Rabi; Medvedeva, Julia

    2015-03-01

    In recent years, there is an increasing shift towards the use of oxide semiconductor materials in their amorphous form owing to several technological advantages and the fact that amorphous oxides exhibit similar or even superior properties than their crystalline counterparts. In this work we have systemically investigated the effect of chemical composition and oxygen stoichiometry on the local and long-range structure of ternary amorphous oxides, namely In-X-O with X =Sn, Zn, Ga, Cd, Ge, Sc, Y, or La, by means of ab-initio molecular dynamics. The results reveal that the local MO structure remains nearly intact upon amorphization and exhibit weak dependence on the composition. In marked contrast, the structural characteristics of the metal-metal shell, namely, the M-M distances and M-O-M angles that determine how MO polyhedra are connected into a network, are affected by the presence of X. Complex interplay between several factors such as the cation ionic size, metal-oxygen bond strength, as well as the natural preference for edge, corner, or face-sharing between the MO polyhedra, leads to a correlated behavior in the long-range structure. These findings highlight the mechanisms of the amorphous structure formation as well as the species of the carrier transport in these oxides.

  13. Colloidal Photoluminescent Amorphous Porous Silicon, Methods Of Making Colloidal Photoluminescent Amorphous Porous Silicon, And Methods Of Using Colloidal Photoluminescent Amorphous Porous Silicon

    KAUST Repository

    Chaieb, Sahraoui

    2015-04-09

    Embodiments of the present disclosure provide for a colloidal photoluminescent amorphous porous silicon particle suspension, methods of making a colloidal photoluminescent amorphous porous silicon particle suspension, methods of using a colloidal photoluminescent amorphous porous silicon particle suspension, and the like.

  14. Nanoscale manipulation of Ge nanowires by ion hammering

    Energy Technology Data Exchange (ETDEWEB)

    Picraux, Samuel T [Los Alamos National Laboratory; Romano, Lucia [UNIV OF FLORIDA; Rudawski, Nicholas G [UNIV OF FLORIDA; Holzworth, Monta R [UNIV OF FLORIDA; Jones, Kevin S [UNIV OF FLORIDA; Choi, S G [NREL

    2009-01-01

    Nanowires generated considerable interest as nanoscale interconnects and as active components of both electronic and electromechanical devices. However, in many cases, manipulation and modification of nanowires are required to realize their full potential. It is essential, for instance, to control the orientation and positioning of nanowires in some specific applications. This work demonstrates a simple method to reversibly control the shape and the orientation of Ge nanowires by using ion beams. Initially, crystalline nanowires were partially amorphized by 30 keY Ga+-implantation. After amorphization, viscous flow and plastic deformation occurred due to the ion hammering effect, causing the nanowires to bend toward the beam direction. The bending was reversed multiple times by ion-implanting the opposite side of the nanowires, resulting in straightening of the nanowires and subsequent bending in the opposite direction. This ion hammering effect demonstrates the detailed manipulation of nanoscale structures is possible through the use of ion irradiation.

  15. Behaviors of Zn2GeO4 under high pressure and high temperature

    Science.gov (United States)

    Shu-Wen, Yang; Fang, Peng; Wen-Tao, Li; Qi-Wei, Hu; Xiao-Zhi, Yan; Li, Lei; Xiao-Dong, Li; Duan-Wei, He

    2016-07-01

    The structural stability of Zn2GeO4 was investigated by in-situ synchrotron radiation angle dispersive x-ray diffraction. The pressure-induced amorphization is observed up to 10 GPa at room temperature. The high-pressure and high-temperature sintering experiments and the Raman spectrum measurement firstly were performed to suggest that the amorphization is caused by insufficient thermal energy and tilting Zn-O-Ge and Ge-O-Ge bond angles with increasing pressure, respectively. The calculated bulk modulus of Zn2GeO4 is 117.8 GPa from the pressure-volume data. In general, insights into the mechanical behavior and structure evolution of Zn2GeO4 will shed light on the micro-mechanism of the materials variation under high pressure and high temperature. Project supported by the Joint Fund of the National Natural Science Foundation of China and Chinese Academy of Sciences (Grant No. U1332104).

  16. Influence of the Composition on the Thermoelectric and Electro-physical Properties of Ge-Sb-Te Thin Films for Phase Change Memory Application

    Directory of Open Access Journals (Sweden)

    P.I. Lazarenko

    2016-10-01

    Full Text Available Influence of the composition variation along the quasi-binary line GeTe-Sb2Te3 on the thermoelectric and electro-physical properties of thin films was investigated. GST amorphous thin films have high Seebeck coefficients, which drops nearly on the order of magnitude after the crystallization. Temperature dependences of the resistivities were studied, and it was determined that crystallization temperature increases with moving along the quasi-binary line GeTe-Sb2Te3 from GeSb4Te7 to GeSb2Te4, and then to Ge2Sb2Te5, while the phase transition temperature range decreases. Current-voltage characteristics of amorphous thin films have three voltage ranges with different dependencies due to the different mechanisms of charge carrier transport.

  17. BIPOLAR DISORDER AND METABOLIC SYNDROME: COMORBIDITY OR SIDE EFFECTS OF TREATMENT OF BIPOLAR DISORDER

    OpenAIRE

    Babić, Dragan; Maslov, Boris; Nikolić, Katica; Martinac, Marko; Uzun, Suzana; Kozumplik, Oliver

    2010-01-01

    Objective: There is evidence that people with mental disorders are more likely to suffer from metabolic syndrome. In the last decades there has been an increase in interest for researching metabolic syndrome in psychiatric patients and plenty of evidence about their association. However, investigations on the prevalence of metabolic syndrome in patients with bipolar disorder are still surprisingly rare. The aim of this paper is to analyze comorbidity of bipolar disorder and metabolic syndrome...

  18. Commentary on N. Ghaemi's “Hippocratic Psychopharmacology of Bipolar Disorder” Maintenance Treatment in Bipolar Disorder

    OpenAIRE

    Tohen, Mauricio; Lin, Daniel

    2006-01-01

    Bipolar disorder is a chronic recurring condition that is associated with high mortality and severe functional and psychosocial impairments. Treatment strategies that prolong recovery from a mood episode and delay relapse into a new mood episode are essential for long-term improvements in outcomes. Maintenance treatments for bipolar disorder should be evaluated on the strength of the empirical evidence and with the recognition that some treatments may be more effective in preventing relapse i...

  19. Clinical variables and implications of the personality on the outcome of bipolar illness: a pilot study

    OpenAIRE

    Casas-Barquero, Nieves; García-López, Olga; Fernández-Argüelles, Pedro; Camacho-Laraña, Manuel

    2007-01-01

    Outcome in bipolar patients is affected by comorbidity. Comorbid personality disorders are frequent and may complicate the course of bipolar illness. This pilot study examined a series of 40 euthymic bipolar patients (DSM-IV criteria) (bipolar I disorder 31, bipolar II disorder 9) to assess the effect of clinical variables and the influence of comorbid personality on the clinical course of bipolar illness. Bipolar patients with a diagnosis of comorbid personality disorder (n = 30) were compar...

  20. Rapid Thermal annealing of silicon layers amorphized by ion implantation

    International Nuclear Information System (INIS)

    The recrystallization behavior and the supression mechanisms of the residual defects of silicon layers amorphized by ion implantation, were investigated. The samples were annealed with the aid of a rapid thermal annealing (RTA) system at temperature range from 850 to 12000C, and annealing time up to 120 s. Random and aligned Rutherford backscattering spectroscopy were used to analyse the samples. Similarities in the recrystallization behavior for layers implanted with ions of the same chemical groups such as As or Sb; Ge, Sn or Pb, In or Ga, are observed. The results show that the effective supression of resisual defects of the recrystallired layers is vinculated to the redistribution of impurities via thermal diffusion. (author)

  1. Heritability of cognitive functions in families with bipolar disorder.

    Science.gov (United States)

    Antila, Mervi; Tuulio-Henriksson, Annamari; Kieseppä, Tuula; Soronen, Pia; Palo, Outi M; Paunio, Tiina; Haukka, Jari; Partonen, Timo; Lönnqvist, Jouko

    2007-09-01

    Bipolar disorder is highly heritable. Cognitive dysfunctions often observed in bipolar patients and their unaffected relatives implicate that these impairments may be associated with genetic predisposition to bipolar disorder and thus fulfill the criteria of a valid endophenotype for the disorder. However, the most fundamental criterion, their heritability, has not been directly studied in any bipolar population. This population-based study estimated the heritability of cognitive functions in bipolar disorder. A comprehensive neuropsychological test battery and the Structured Clinical Interview for DSM-IV were administered to a population-based sample of 110 individuals from 52 families with bipolar disorder. Heritability of cognitive functions as assessed with neuropsychological test scores were estimated using the Solar package. Significant additive heritabilities were found in verbal ability, executive functioning, and psychomotor processing speed. Genetic contribution was low to verbal learning functions. High heritability, in executive functioning and psychomotor processing speed suggest that these may be valid endophenotypic traits for genetic studies of bipolar disorder.

  2. Cognitive enhancement treatments for bipolar disorder

    DEFF Research Database (Denmark)

    Miskowiak, Kamilla W; Carvalho, André F; Vieta, Eduard;

    2016-01-01

    Cognitive dysfunction is an emerging treatment target in bipolar disorder (BD). Several trials have assessed the efficacy of novel pharmacological and psychological treatments on cognition in BD but the findings are contradictory and unclear. A systematic search following the PRISMA guidelines...

  3. Bias in emerging biomarkers for bipolar disorder

    DEFF Research Database (Denmark)

    Carvalho, A F; Köhler, C A; Fernandes, B S;

    2016-01-01

    BACKGROUND: To date no comprehensive evaluation has appraised the likelihood of bias or the strength of the evidence of peripheral biomarkers for bipolar disorder (BD). Here we performed an umbrella review of meta-analyses of peripheral non-genetic biomarkers for BD. METHOD: The Pubmed...

  4. Designing Mobile Health Technology for Bipolar Disorder

    DEFF Research Database (Denmark)

    Bardram, JE; Frost, Mads; Szántó, Károly;

    2013-01-01

    An increasing number of pervasive healthcare systems are being designed, that allow people to monitor and get feedback on their health and wellness. To address the challenges of self-management of mental illnesses, we have developed the MONARCA system - a personal monitoring system for bipolar...

  5. Homocysteine and cognitive functions in bipolar depression

    Directory of Open Access Journals (Sweden)

    Agnieszka Permoda-Osip

    2014-12-01

    The results obtained show higher HCY concentration in considerable proportion of patients with bipolar depression, especially in men. They also confirm a connect between high homocysteine concentration and worse performance in some neuropsychological tests. Such relationship was more marked in men.

  6. Electrostatic Changes Observed with Narrow Bipolar Pulses

    Science.gov (United States)

    Karunarathne, S.; Marshall, T. C.; Stolzenburg, M.; Karunarathna, N.

    2015-12-01

    Narrow bipolar pulses (NBPs) or compact intracloud discharges are impulsive discharges that are considered to be the strongest natural emitters in the HF radio band; they usually occur at high altitudes in some thunderstorms. In the summer of 2011, we collected E-change data with wideband flat-plate antennas (0.16 Hz - 2.5 MHz) at ten stations covering an area of nearly 70 km x 100 km in and around Kennedy Space Center, Florida, USA. On one thunderstorm day, 14 August 2011, we detected 226 positive NBPs, and some observations of these pulses were published in Karunarathne et al. [2015, JGR-atmospheres]. Of these 226 NBPs, 50 (22.1 %) occurred within 10 km horizontally of at least one sensor. All of these closer sensors show electrostatic changes associated with corresponding NBPs, with a net electrostatic change in the main bipolar pulse and with a slower electrostatic change after the bipolar pulse that seems similar to short continuing current immediately after some cloud-to-ground return strokes. Although NBPs have been considered as short duration pulses (10 - 20 microseconds), the electrostatic changes after the main bipolar pulse ranged from 0.7 ms to 34 ms and associated charge moments were calculated. The total duration of the electrostatic E-change was strongly dependent on the distance to the sensors. In this presentation, we will present data for these electrostatic changes, some statistics, and physical background and reasoning for the electrostatic changes.

  7. Unraveling Psychomotor Slowing in Bipolar Disorde

    NARCIS (Netherlands)

    Morsel, A.M.; Temmerman, A.; Sabbe, B.G.C.; Hulstijn, W.; Morrens, M.

    2015-01-01

    Background/Aims: In addition to affective and cognitive symptomatology, psychomotor deficits are known to be present in bipolar disorder (BD). Psychomotor functioning includes all of the processes necessary for completing a movement, from planning to initiation and execution. While these psychomotor

  8. Bipolar disorder: from genes to behavior pathways

    OpenAIRE

    Martinowich, Keri; Schloesser, Robert J; Manji, Husseini K

    2009-01-01

    Bipolar disorder (BPD) is a devastating illness that is characterized by recurrent episodes of mania and depression. In addition to these cyclic episodes, individuals with BPD exhibit changes in psychovegetative function, cognitive performance, and general health and well being. In this article we draw from neuroimaging findings in humans, postmortem data, and human genetic and pharmacological studies as well as ...

  9. Mechanism on bipolar distribution of Permian brachiopods

    Institute of Scientific and Technical Information of China (English)

    Chengwen WANG; Songmei ZHANG

    2008-01-01

    By reasearch on geographic distribution, nine genera in bipolar distribution are selected from Permian brachiopods. These taxa originated from middle-high latitude areas in the boreal realm, of which five genera were derived from Late Carboniferous, and other four genera originated from Permian. They were all in bipolar distribution during some different stages in Permian. Specific diversity for each genus was high in the boreal realm, whereas in the Gondwana realm was very low. Perdurability was long in the boreal realm, and short in the Gondwana realm. It was the time when these nine genera came to their maximum diversity that these genera appeared in the Gondwana and formed bipolar distribution; while they also migrated to the low latitude from high latitude. This shows very close relationship between several main cooling events in Permian and the migration of genera from the boreal realm to the Gondwana realm through the Tethys. Therefore, the cooling events might be the main drive which caused these cold-water-type brachiopods migrated to the Gondwana realm and being bipolar distribution. In this process, the planula tolerance to warm water would be another important factor.

  10. Vacuum interface flashover with bipolar electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, W.K.; Anderson, R.A.; Hasti, D.E.; Jones, E.E.; Bennett, L.F.

    1985-05-01

    High energy, compact, particle accelerators require accelerating cavities that have large gradients and operate with high efficiency. The bipolar electric fields required in these efficient accelerating cavities place severe requirements on the vacuum interface. Experimentally, we have found that the bipolar flashover field varies as t/sup -1/2/ for times out to 300 ns and then remains essentially constant at 33 kV/cm for longer duration waveforms, whereas materials subjected to unipolar electric fields follow a t/sup -1/6/ relationship. Furthermore, specific accelerating cavities offer enhancements that may be employed to achieve highly uniform electric fields across the vacuum interface. Using these results and the results of a previously developed theory of unipolar flashover, a new interface has been designed and 50 kV/cm bipolar flashover field achieved for a waveform train that lasted 1 ..mu..s. This paper will discuss the design of this vacuum interface and the evaluation of various materials that led to achieving bipolar flashover fields 50% greater than we had previously obtained for long duration waveforms. 10 refs., 6 figs.

  11. Vacuum interface flashover with bipolar electric fields

    International Nuclear Information System (INIS)

    High energy, compact, particle accelerators require accelerating cavities that have large gradients and operate with high efficiency. The bipolar electric fields required in these efficient accelerating cavities place severe requirements on the vacuum interface. Experimentally, we have found that the bipolar flashover field varies as t/sup -1/2/ for times out to 300 ns and then remains essentially constant at 33 kV/cm for longer duration waveforms, whereas materials subjected to unipolar electric fields follow a t/sup -1/6/ relationship. Furthermore, specific accelerating cavities offer enhancements that may be employed to achieve highly uniform electric fields across the vacuum interface. Using these results and the results of a previously developed theory of unipolar flashover, a new interface has been designed and 50 kV/cm bipolar flashover field achieved for a waveform train that lasted 1 μs. This paper will discuss the design of this vacuum interface and the evaluation of various materials that led to achieving bipolar flashover fields 50% greater than we had previously obtained for long duration waveforms. 10 refs., 6 figs

  12. Corrosion test cell for bipolar plates

    Science.gov (United States)

    Weisbrod, Kirk R.

    2002-01-01

    A corrosion test cell for evaluating corrosion resistance in fuel cell bipolar plates is described. The cell has a transparent or translucent cell body having a pair of identical cell body members that seal against opposite sides of a bipolar plate. The cell includes an anode chamber and an cathode chamber, each on opposite sides of the plate. Each chamber contains a pair of mesh platinum current collectors and a catalyst layer pressed between current collectors and the plate. Each chamber is filled with an electrolyte solution that is replenished with fluid from a much larger electrolyte reservoir. The cell includes gas inlets to each chamber for hydrogen gas and air. As the gases flow into a chamber, they pass along the platinum mesh, through the catalyst layer, and to the bipolar plate. The gas exits the chamber through passageways that provide fluid communication between the anode and cathode chambers and the reservoir, and exits the test cell through an exit port in the reservoir. The flow of gas into the cell produces a constant flow of fresh electrolyte into each chamber. Openings in each cell body is member allow electrodes to enter the cell body and contact the electrolyte in the reservoir therein. During operation, while hydrogen gas is passed into one chamber and air into the other chamber, the cell resistance is measured, which is used to evaluate the corrosion properties of the bipolar plate.

  13. Bipolar disorder: Evidence for a major locus

    Energy Technology Data Exchange (ETDEWEB)

    Spence, M.A.; Flodman, P.L. [Univ. of California, Irvine, CA (United States); Sadovnick, A.D.; Ameli, H. [Univ. of British Columbia, Vancouver (Canada)] [and others

    1995-10-09

    Complex segregation analyses were conducted on families of bipolar I and bipolar II probands to delineate the mode of inheritance. The probands were ascertained from consecutive referrals to the Mood Disorder Service, University Hospital, University of British Columbia and diagnosed by DSM-III-R and Research Diagnostic Criteria. Data were available on over 1,500 first-degree relatives of the 186 Caucasian probands. The purpose of the analyses was to determine if, after correcting for age and birth cohort, there was evidence for a single major locus. Five models were fit to the data using the statistical package SAGE: (1) dominant, (2) recessive, (3) arbitrary mendelian inheritance, (4) environmental, and (5) no major effects. A single dominant, mendelian major locus was the best fitting of these models for the sample of bipolar I and II probands when only bipolar relatives were defined as affected (polygenic inheritance could not be tested). Adding recurrent major depression to the diagnosis {open_quotes}affected{close_quotes} for relatives reduced the evidence for a major locus effect. Our findings support the undertaking of linkage studies and are consistent with the analyses of the National Institutes of Mental Health (NIMH) Collaborative Study data by Rice et al. and Blangero and Elston. 39 refs., 4 tabs.

  14. On Structure and Properties of Amorphous Materials

    Directory of Open Access Journals (Sweden)

    Zbigniew H. Stachurski

    2011-09-01

    Full Text Available Mechanical, optical, magnetic and electronic properties of amorphous materials hold great promise towards current and emergent technologies. We distinguish at least four categories of amorphous (glassy materials: (i metallic; (ii thin films; (iii organic and inorganic thermoplastics; and (iv amorphous permanent networks. Some fundamental questions about the atomic arrangements remain unresolved. This paper focuses on the models of atomic arrangements in amorphous materials. The earliest ideas of Bernal on the structure of liquids were followed by experiments and computer models for the packing of spheres. Modern approach is to carry out computer simulations with prediction that can be tested by experiments. A geometrical concept of an ideal amorphous solid is presented as a novel contribution to the understanding of atomic arrangements in amorphous solids.

  15. Effect of Si interface surface roughness to the tunneling current of the Si/Si1-xGex/Si heterojunction bipolar transistor

    Science.gov (United States)

    Hasanah, Lilik; Suhendi, Endi; Tayubi, Yuyu Rahmat; Yuwono, Heru; Nandiyanto, Asep Bayu Dani; Murakami, Hideki; Khairrurijal

    2016-02-01

    In this work we discuss the surface roughness of Si interface impact to the tunneling current of the Si/Si1-xGex/Si heterojunction bipolar transistor. The Si interface surface roughness can be analyzed from electrical characteristics through the transversal electron velocity obtained as fitting parameter factor. The results showed that surface roughness increase as Ge content of virtual substrate increase This model can be used to investigate the effect of Ge content of the virtual substrate to the interface surface condition through current-voltage characteristic.

  16. The physics and applications of amorphous semiconductors

    CERN Document Server

    Madan, Arun

    1988-01-01

    This comprehensive, detailed treatise on the physics and applications of the new emerging technology of amorphous semiconductors focuses on specific device research problems such as the optimization of device performance. The first part of the book presents hydrogenated amorphous silicon type alloys, whose applications include inexpensive solar cells, thin film transistors, image scanners, electrophotography, optical recording and gas sensors. The second part of the book discusses amorphous chalcogenides, whose applications include electrophotography, switching, and memory elements. This boo

  17. Unmet needs of bipolar disorder patients

    Directory of Open Access Journals (Sweden)

    Hajda M

    2016-06-01

    Full Text Available Miroslav Hajda,1 Jan Prasko,1 Klara Latalova,1 Radovan Hruby,2 Marie Ociskova,1 Michaela Holubova,1,3 Dana Kamaradova,1 Barbora Mainerova1 1Department of Psychiatry, Faculty of Medicine and Dentistry, Palacky University Olomouc, University Hospital Olomouc, Olomouc, Czech Republic; 2Outpatient Psychiatric Department, Martin, Slovak Republic; 3Department of Psychiatry, Regional Hospital Liberec, Liberec, Czech Republic Background: Bipolar disorder (BD is a serious mental illness with adverse impact on the lives of the patients and their caregivers. BD is associated with many limitations in personal and interpersonal functioning and restricts the patients’ ability to use their potential capabilities fully. Bipolar patients long to live meaningful lives, but this goal is hard to achieve for those with poor insight. With progress and humanization of society, the issue of patients’ needs became an important topic. The objective of the paper is to provide the up-to-date data on the unmet needs of BD patients and their caregivers. Methods: A systematic computerized examination of MEDLINE publications from 1970 to 2015, via the keywords “bipolar disorder”, “mania”, “bipolar depression”, and “unmet needs”, was performed. Results: Patients’ needs may differ in various stages of the disorder and may have different origin and goals. Thus, we divided them into five groups relating to their nature: those connected with symptoms, treatment, quality of life, family, and pharmacotherapy. We suggested several implications of these needs for pharmacotherapy and psychotherapy. Conclusion: Trying to follow patients’ needs may be a crucial point in the treatment of BD patients. However, many needs remain unmet due to both medical and social factors. Keywords: bipolar disorder, unmet needs, stigma, treatment, medication, quality of life, family, psychotherapy

  18. Forbidden energy band gap in diluted a-Ge1−xSix:N films

    International Nuclear Information System (INIS)

    By means of electron gun evaporation Ge1−xSix:N thin films, in the entire range 0 ≤ x ≤ 1, were prepared on Si (100) and glass substrates. The initial vacuum reached was 6.6 × 10−4 Pa, then a pressure of 2.7 × 10−2 Pa of high purity N2 was introduced into the chamber. The deposition time was 4 min. Crucible-substrate distance was 18 cm. X-ray diffraction patterns indicate that all the films were amorphous (a-Ge1−xSix:N). The nitrogen concentration was of the order of 1 at% for all the films. From optical absorption spectra data and by using the Tauc method the energy band gap (Eg) was calculated. The Raman spectra only reveal the presence of Si-Si, Ge-Ge, and Si-Ge bonds. Nevertheless, infrared spectra demonstrate the existence of Si-N and Ge-N bonds. The forbidden energy band gap (Eg) as a function of x in the entire range 0 ≤ x ≤ 1 shows two well defined regions: 0 ≤ x ≤ 0.67 and 0.67 ≤ x ≤ 1, due to two different behaviors of the band gap, where for x > 0.67 exists an abruptly change of Eg(x). In this case Eg(x) versus x is different to the variation of Eg in a-Ge1−xSix and a-Ge1−xSix:H. This fact can be related to the formation of Ge3N4 and GeSi2N4 when x ≤ 0.67, and to the formation of Si3N4 and GeSi2N4 for 0.67 ≤ x. - Highlights: ► Nitrogen doped amorphous Ge1-xSix thin films are grown by electron gun technique. ► Nitrogen atoms on Eg of the a-Ge1-xSix films in the 0 £ x £ 1 range are analyzed. ► Variation in 0 £ x £ 1 range shows a warped change of Eg in 1.0 – 3.6 eV range. ► The change in Eg(x) behavior when x ∼ 0.67 was associated with Ge2SiN4 presence.

  19. Recent developments in amorphous silicon-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Beneking, C.; Rech, B.; Foelsch, J.; Wagner, H. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Schicht- und Ionentechnik

    1996-03-01

    Two examples of recent advances in the field of thin-film, amorphous hydrogenated silicon (a-Si:H) pin solar cells are described: the improved understanding and control of the p/i interface, and the improvement of wide-bandgap a-Si:H material deposited at low substrate temperature as absorber layer for cells with high stabilized open-circuit voltage. Stacked a-Si:H/a-Si:H cells incorporating these concepts exhibit less than 10% (relative) efficiency degradation and show stabilized efficiencies as high as 9 to 10% (modules 8 to 9%). The use of low-gap a-Si:H and its alloys like a-SiGe:H as bottom cell absorber materials in multi-bandgap stacked cells offers additional possibilities. The combination of a-Si:H based top cells with thin-film crystalline silicon-based bottom cells appears as a promising new trend. It offers the perspective to pass significantly beyond the present landmark of 10% module efficiency reached by the technology utilizing exclusively amorphous silicon-based absorber layers, while keeping its advantages of potentially low-cost production. (orig.) 47 refs.

  20. Hydrophobic transition in porous amorphous silica

    International Nuclear Information System (INIS)

    Realistic models of amorphous silica surfaces with different silanol densities are built using Monte Carlo annealing. Water-silica interfaces are characterized by their energy interaction maps, adsorption isotherms, self-diffusion coefficients, and Poiseuille flows. A hydrophilic to hydrophobic transition appears as the surface becomes purely siliceous. These results imply significant consequences for the description of surfaces. First, realistic models are required for amorphous silica interfaces. Second, experimental amorphous silica hydrophilicity is attributed to charged or uncharged defects, and not to amorphousness. In addition, auto irradiation in nuclear waste glass releases hydrogen atoms from silanol groups and can induce such a transition. (authors)

  1. Plasma Deposition of Amorphous Silicon

    Science.gov (United States)

    Calcote, H. F.

    1982-01-01

    Strongly adhering films of silicon are deposited directly on such materials as Pyrex and Vycor (or equivalent materials) and aluminum by a non-equilibrium plasma jet. Amorphous silicon films are formed by decomposition of silicon tetrachloride or trichlorosilane in the plasma. Plasma-jet technique can also be used to deposit an adherent silicon film on aluminum from silane and to dope such films with phosphorus. Ability to deposit silicon films on such readily available, inexpensive substrates could eventually lead to lower cost photovoltaic cells.

  2. Polymeric amorphous carbon as p-type window within amorphous silicon solar cells

    NARCIS (Netherlands)

    Khan, R.U.A.; Silva, S.R.P.; Van Swaaij, R.A.C.M.M.

    2003-01-01

    Amorphous carbon (a-C) has been shown to be intrinsically p-type, and polymeric a-C (PAC) possesses a wide Tauc band gap of 2.6 eV. We have replaced the p-type amorphous silicon carbide layer of a standard amorphous silicon solar cell with an intrinsic ultrathin layer of PAC. The thickness of the p

  3. Pure, single crystal Ge nanodots formed using a sandwich structure via pulsed UV excimer laser annealing.

    Science.gov (United States)

    Liao, Ting-Wei; Chen, Hung-Ming; Shen, Kuan-Yuan; Kuan, Chieh-Hsiung

    2015-04-24

    In this paper, a sandwich structure comprising a SiO2 capping layer, amorphous Germanium (a-Ge) nanodots (NDs), and a pit-patterned Silicon (Si) substrate is developed, which is then annealed by utilizing a pulsed ultraviolet excimer laser in order to fabricate an array of pure, single crystal Ge NDs at room temperature. A wide bandgap SiO2 capping layer is used as a transparent thermally isolated layer to prevent thermal loss and Si-Ge intermixing. The two-dimensional pit-patterned Si substrate is designed to confine the absorbed laser energy, reduce the melting point, and block the surface migration of the Ge. After optimizing the laser radiation parameters such that the laser energy density is 200 mJ cm(-2), the laser annealing period is 10 s, and the number of laser shots is 10, pure, single crystal Ge NDs that have both a regular arrangement and a uniform size distribution are obtained in the pits of the Si substrates. The Raman spectrum shows a highly symmetric Ge transversal optical peak with a full width at half maximum of 4.2 cm(-1) at 300.7 cm(-1), which is close to that of the original Ge wafer. In addition, the high-resolution transmission electron microscopy image for the Ge NDs and the corresponding selected area electron diffraction pattern shows a clear single crystalline structure without any impurities. PMID:25815515

  4. Laser surface treatment of amorphous metals

    Science.gov (United States)

    Katakam, Shravana K.

    Amorphous materials are used as soft magnetic materials and also as surface coatings to improve the surface properties. Furthermore, the nanocrystalline materials derived from their amorphous precursors show superior soft magnetic properties than amorphous counter parts for transformer core applications. In the present work, laser based processing of amorphous materials will be presented. Conventionally, the nanocrystalline materials are synthesized by furnace heat treatment of amorphous precursors. Fe-based amorphous/nanocrystalline materials due to their low cost and superior magnetic properties are the most widely used soft magnetic materials. However, achieving nanocrystalline microstructure in Fe-Si-B ternary system becomes very difficult owing its rapid growth rate at higher temperatures and sluggish diffusion at low temperature annealing. Hence, nanocrystallization in this system is achieved by using alloying additions (Cu and Nb) in the ternary Fe-Si-B system. Thus, increasing the cost and also resulting in reduction of saturation magnetization. laser processing technique is used to achieve extremely fine nanocrystalline microstructure in Fe-Si-B amorphous precursor. Microstructure-magnetic Property-laser processing co-relationship has been established for Fe-Si-B ternary system using analytical techniques. Laser processing improved the magnetic properties with significant increase in saturation magnetization and near zero coercivity values. Amorphous materials exhibit excellent corrosion resistance by virtue of their atomic structure. Fe-based amorphous materials are economical and due to their ease of processing are of potential interest to synthesize as coatings materials for wear and corrosion resistance applications. Fe-Cr-Mo-Y-C-B amorphous system was used to develop thick coatings on 4130 Steel substrate and the corrosion resistance of the amorphous coatings was improved. It is also shown that the mode of corrosion depends on the laser processing

  5. Study of gold diffusion in thin-film glass semiconductor GeTe4 by nuclear methods

    International Nuclear Information System (INIS)

    Recent considerable interest has been brought to amorphous S.C. Their study can lead to a greater understanding of the non-crystalline state as well as of crystallization mechanisms. Gold thin-film-diffusion profiles into the A.S.C. Ge18Te82 has been studied versus different annealing conditions using nuclear backscattering analysis. Atomic diffusion into the amorphous film has been showed to be tightly related to the diffusion into polycristalline configurations, and classical polycrystalline models have been successfully employed in the amorphous case. Moreover, the comparison between air and vacuum annealing has emphasized the delaying action of oxygen. This element, adsorbed mainly on Ge and Te sites, leads to oxide formation that can even inhibit the nucleation and growth processes of the crystalline compound AuTesub(1,7)

  6. Abordagens psicoterápicas no transtorno bipolar Psychoterapeutic approach in bipolar disorder

    Directory of Open Access Journals (Sweden)

    Paulo Knapp

    2005-01-01

    Full Text Available Embora o tratamento farmacológico seja essencial para o tratamento do transtorno bipolar, apenas 40% de todos os pacientes que aderem às medicações permanecem assintomáticos durante o período de seguimento, o que tem levado ao desenvolvimento de intervenções psicoterápicas associadas. O objetivo deste artigo é examinar as evidências atuais da eficácia de intervenções psicoterápicas no tratamento do transtorno bipolar. Foi realizada uma pesquisa bibliográfica por meio do MedLine, PsychoINFO, Lilacs e Cochrane Data Bank, até o ano de 2004, em que foram procurados artigos originais e revisões sobre as abordagens psicoterápicas utilizadas no tratamento do transtorno bipolar. Há várias abordagens que podem se mostrar úteis no tratamento do transtorno bipolar. A psicoeducação e a terapia cognitivo-comportamental apresentam as evidências mais consistentes e são as técnicas mais amplamente estudadas. As intervenções envolvendo familiares e a terapia interpessoal e de ritmo social se mostram tratamentos eficazes em determinadas situações. Há alguns estudos empregando a terapia psicodinâmica no transtorno bipolar, mas são estudos com limitações metodológicas. Apesar de haver evidências demonstrando a eficácia de determinadas abordagens psicoterápicas no transtorno bipolar, ainda é necessária a realização de estudos posteriores que comprovem tais dados e que desenvolvam tratamentos baseados em modelos etiológicos e que identifiquem tratamentos específicos para as diferentes fases e tipos de transtorno bipolar.Although pharmacological treatment is essential for treating bipolar disorder, less than half of all medication compliant patients are non-symptomatic during follow-up, which has led to developments of adjunctive psychosocial interventions. This paper examines the current evidence for effectiveness of psychotherapeutic interventions in the treatment of bipolar disorder. Searches were undertaken through Med

  7. Electron tunnelling into amorphous germanium and silicon.

    Science.gov (United States)

    Smith, C. W.; Clark, A. H.

    1972-01-01

    Measurements of tunnel conductance versus bias, capacitance versus bias, and internal photoemission were made in the systems aluminum-oxide-amorphous germanium and aluminium-oxide-amorphous silicon. A function was extracted which expresses the deviation of these systems from the aluminium-oxide-aluminium system.

  8. Band Gaps of an Amorphous Photonic Materials

    Institute of Scientific and Technical Information of China (English)

    WANG Yi-Quan; FENG Zhi-Fang; HU Xiao-Yong; CHENG Bing-Ying; ZHANG Dao-Zhong

    2004-01-01

    @@ A new kind of amorphous photonic materials is presented. Both the simulated and experimental results show that although the disorder of the whole dielectric structure is strong, the amorphous photonic materials have two photonic gaps. This confirms that the short-range order is an essential factor for the formation of the photonic gaps.

  9. Towards upconversion for amorphous silicon solar cells

    NARCIS (Netherlands)

    de Wild, J.; Meijerink, A.; Rath, J.K.; van Sark, W.G.J.H.M.; Schropp, R.E.I.

    2010-01-01

    Upconversion of subbandgap light of thin film single junction amorphous silicon solar cells may enhance their performance in the near infrared (NIR). In this paper we report on the application of the NIR–vis upconverter β-NaYF4:Yb3+(18%) Er3+(2%) at the back of an amorphous silicon solar cell in com

  10. Electron beam recrystallization of amorphous semiconductor materials

    Science.gov (United States)

    Evans, J. C., Jr.

    1968-01-01

    Nucleation and growth of crystalline films of silicon, germanium, and cadmium sulfide on substrates of plastic and glass were investigated. Amorphous films of germanium, silicon, and cadmium sulfide on amorphous substrates of glass and plastic were converted to the crystalline condition by electron bombardment.

  11. Systematic review of the prevalence of bipolar disorder and bipolar spectrum disorders in population-based studies

    Directory of Open Access Journals (Sweden)

    José Caetano Dell'Aglio Jr.

    2013-01-01

    Full Text Available This paper describes the findings of a systematic literature review aimed at providing an overview of the lifetime prevalence of bipolar disorder and bipolar spectrum disorders in population-based studies. Databases MEDLINE, ProQuest, Psychnet, and Web of Science were browsed for papers published in English between 1999 and May 2012 using the following search string: bipolar disorders OR bipolar spectrum disorders AND prevalence OR cross-sectional OR epidemiology AND population-based OR non-clinical OR community based. The search yielded a total of 434 papers, but only those published in peer-reviewed journals and with samples aged ≥ 18 years were included, resulting in a final sample of 18 papers. Results revealed rather heterogeneous findings concerning the prevalence of bipolar disorders and bipolar spectrum disorders. Lifetime prevalence of bipolar disorder ranged from 0.1 to 7.5%, whereas lifetime prevalence of bipolar spectrum disorders ranged from 2.4 to 15.1%. Differences in the rates of bipolar disorder and bipolar spectrum disorders may be related to the consideration of subthreshold criteria upon diagnosis. Differences in the prevalence of different subtypes of the disorder are discussed in light of diagnostic criteria and instruments applied.

  12. Solid-state diffusion in amorphous zirconolite

    Science.gov (United States)

    Yang, C.; Zarkadoula, E.; Dove, M. T.; Todorov, I. T.; Geisler, T.; Brazhkin, V. V.; Trachenko, K.

    2014-11-01

    We discuss how structural disorder and amorphization affect solid-state diffusion, and consider zirconolite as a currently important case study. By performing extensive molecular dynamics simulations, we disentangle the effects of amorphization and density, and show that a profound increase of solid-state diffusion takes place as a result of amorphization. Importantly, this can take place at the same density as in the crystal, representing an interesting general insight regarding solid-state diffusion. We find that decreasing the density in the amorphous system increases pre-factors of diffusion constants, but does not change the activation energy in the density range considered. We also find that atomic species in zirconolite are affected differently by amorphization and density change. Our microscopic insights are relevant for understanding how solid-state diffusion changes due to disorder and for building predictive models of operation of materials to be used to encapsulate nuclear waste.

  13. Neutron irradiation induced amorphization of silicon carbide

    International Nuclear Information System (INIS)

    This paper provides the first known observation of silicon carbide fully amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60 C to a total fast neutron fluence of 2.6 x 1025 n/m2. Amorphization was seen in both materials, as evidenced by TEM, electron diffraction, and x-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density (-10.8%), elastic modulus as measured using a nanoindentation technique (-45%), hardness as measured by nanoindentation (-45%), and standard Vickers hardness (-24%). Similar property changes are observed for the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than 130 C

  14. Neutron irradiation induced amorphization of silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Snead, L.L.; Hay, J.C. [Oak Ridge National Lab., TN (United States)

    1998-09-01

    This paper provides the first known observation of silicon carbide fully amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60 C to a total fast neutron fluence of 2.6 {times} 10{sup 25} n/m{sup 2}. Amorphization was seen in both materials, as evidenced by TEM, electron diffraction, and x-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density ({minus}10.8%), elastic modulus as measured using a nanoindentation technique ({minus}45%), hardness as measured by nanoindentation ({minus}45%), and standard Vickers hardness ({minus}24%). Similar property changes are observed for the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than 130 C.

  15. Solid-state diffusion in amorphous zirconolite

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.; Dove, M. T.; Trachenko, K. [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Zarkadoula, E. [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6138 (United States); Todorov, I. T. [STFC Daresbury Laboratory, Warrington WA4 1EP (United Kingdom); Geisler, T. [Steinmann-Institut für Geologie, Mineralogie und Paläontologie, University of Bonn, D-53115 Bonn (Germany); Brazhkin, V. V. [Institute for High Pressure Physics, RAS, 142190 Moscow (Russian Federation)

    2014-11-14

    We discuss how structural disorder and amorphization affect solid-state diffusion, and consider zirconolite as a currently important case study. By performing extensive molecular dynamics simulations, we disentangle the effects of amorphization and density, and show that a profound increase of solid-state diffusion takes place as a result of amorphization. Importantly, this can take place at the same density as in the crystal, representing an interesting general insight regarding solid-state diffusion. We find that decreasing the density in the amorphous system increases pre-factors of diffusion constants, but does not change the activation energy in the density range considered. We also find that atomic species in zirconolite are affected differently by amorphization and density change. Our microscopic insights are relevant for understanding how solid-state diffusion changes due to disorder and for building predictive models of operation of materials to be used to encapsulate nuclear waste.

  16. Long-term Treatment in Bipolar Disorder

    Directory of Open Access Journals (Sweden)

    Meliha Zengin Eroglu

    2010-08-01

    Full Text Available Although the importance of long-term prophylactic treatment is certain in bipolar disorder, there is stil debate on how to which patients and evaluate the treatment response. Efficacious long-term treatment can reduce morbidity and mortality significantly and improve quality of life of bipolar patients. The concept of ideal response should also be defined very clearly in order to discuss the difficulties of measuring the effectiveness of the prophylactic treatment. The aims of this paper are to determine whether our currently methods and criteria are valid, reliable and sensitive evaluating the efficacy of the treatment response and to briefly inform the clinicians about the drugs used in pharmacologic prophylaxis in accordance with relevant data.

  17. Comorbidity of Asperger's syndrome and Bipolar disorder

    Directory of Open Access Journals (Sweden)

    Azzoni Antonella

    2008-11-01

    Full Text Available Abstract Background and objective Asperger's Syndrome (AS is a pervasive developmental disorder that is sometimes unrecognized, especially in the adult psychiatric setting. On the other hand, in patients with an AS diagnosis, comorbid psychiatric disorders may be unrecognized in the juvenile setting. The aim of the paper is to show and discuss some troublesome and complex problems of the management of patients with AS and comorbid Bipolar Disorder (BD. Methods The paper describes three patients affected by AS and bipolar spectrum disorders. Results and conclusion Mood stabilizers and 2nd generation antipsychotics were effective in the treatment of these AS patients with comorbid BD, while the use of antidepressants was associated with worsening of the mood disorder. It is of importance to recognize both the psychiatric diagnoses in order to arrange an exhaustive therapeutic program and to define specific and realistic goals of treatment.

  18. Udvikling af medicinsk behandling mod bipolar lidelse

    DEFF Research Database (Denmark)

    Ellegaard, Pernille Kempel

    2015-01-01

    Selvom Esbjerg ligger i vandkants Danmark, er det den Psykiatriske Forskningsenhed i denne by, der er primus motor for et stort forsøg blandt mennesker, der lider af bipolar lidelse. Forsøget hedder ”NACOS”, og er et medicinsk forsøg til mennesker, der befinder sig i den depressive fase.......Selvom Esbjerg ligger i vandkants Danmark, er det den Psykiatriske Forskningsenhed i denne by, der er primus motor for et stort forsøg blandt mennesker, der lider af bipolar lidelse. Forsøget hedder ”NACOS”, og er et medicinsk forsøg til mennesker, der befinder sig i den depressive fase....

  19. Bipolar zinc/oxygen battery development

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, S. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Schlatter, C. [Swiss Federal Inst. of Technology, Lausanne (Switzerland)

    1997-06-01

    A bipolar electrically rechargeable Zn/O{sub 2} battery has been developed. Reticulated copper foam served as substrate for the zinc deposit on the anodic side, and La{sub 0.6}Ca{sub 0.4}CoO{sub 3}-catalyzed bifunctional oxygen electrodes were used on the cathodic side of the cells. The 100 cm{sup 2} unit cell had an open circuit voltage of 1,4 V(O{sub 2}) in moderately alkaline electrolyte. The open circuit voltage and the peak power measured for a stack containing seven cells were ca. 10V and 90W, respectively. The current-potential behaviour was determined as a function of the number of bipolar cells, and the maximum discharge capacity was determined at different discharge rates. (author) 4 figs., 1 ref.

  20. Diagnostic features, prevalence, and impact of bipolar disorder.

    Science.gov (United States)

    Ketter, Terrence A

    2010-06-01

    Bipolar disorder shares depressive symptoms with unipolar major depressive disorder but is defined by episodes of mania or hypomania. Bipolar disorder in its broadest sense has a community lifetime prevalence of 4% and is a severely impairing illness that impacts several aspects of patients' lives. Race, ethnicity, and gender have no effect on prevalence rates, but women are more likely to experience rapid cycling, mixed states, depressive episodes, and bipolar II disorder than men. Patients with bipolar disorder have high rates of disability and higher rates of mortality than individuals without bipolar disorder. Natural causes such as cardiovascular disease and diabetes, as well as suicide and other "unnatural" causes are key contributors to the high mortality rate. The costs associated with bipolar disorder include not only the direct costs of treatment, but also the much greater indirect costs of decreased productivity, excess unemployment, and excess mortality. PMID:20573324

  1. Using Ge Secondary Phases to Enhance the Power Factor and Figure of Merit of Ge17Sb2Te20

    Science.gov (United States)

    Williams, Jared B.; Morelli, Donald T.

    2016-08-01

    Thermoelectric materials are the leading candidate today for applications in solid-state waste-heat recovery/cooling applications. Research and engineering has pushed the ZT, and overall conversion efficiency, of these materials to values which can be deemed practical for commercialization. However, many of the state-of-the-art thermoelectric materials of today utilize elements which are toxic, such as Ag, Pb, Tl, and Cd. Alloys of GeTe and Sb2Te3 were first explored for their applications in phase-change memory, because of their ability to rapidly alternate between crystalline and amorphous phases. Recently, these materials have been identified as materials with ZT (S 2 T/ρκ, where S is the Seebeck coefficient, ρ is the electrical resistivity, T is the operating temperature, and κ is the thermal conductivity) much greater than unity. In this work, the influence of elemental Ge as a secondary phase on transport in Ge17Sb2Te20 was explored. It was found that Ge introduces an additional scattering mechanism, which leads to increased electrical resistivity, Seebeck coefficient, and power factor values as high as 36 μW cm-1 K-2. The thermal conductivity was slightly reduced and the ZT was enhanced across the entire temperature range of measurement, with peak values greater than 2.

  2. Unmet needs of bipolar disorder patients

    OpenAIRE

    Hajda M; Prasko J; Latalova K; Hruby R; Ociskova M; Holubova M; Kamaradova D; Mainerova B

    2016-01-01

    Miroslav Hajda,1 Jan Prasko,1 Klara Latalova,1 Radovan Hruby,2 Marie Ociskova,1 Michaela Holubova,1,3 Dana Kamaradova,1 Barbora Mainerova1 1Department of Psychiatry, Faculty of Medicine and Dentistry, Palacky University Olomouc, University Hospital Olomouc, Olomouc, Czech Republic; 2Outpatient Psychiatric Department, Martin, Slovak Republic; 3Department of Psychiatry, Regional Hospital Liberec, Liberec, Czech Republic Background: Bipolar disorder (BD) is a serious mental illness with advers...

  3. The Bipolar Quantum Drift-diffusion Model

    Institute of Scientific and Technical Information of China (English)

    Xiu Qing CHEN; Li CHEN

    2009-01-01

    A fourth order parabolic system, the bipolar quantum drift-diffusion model in semiconductor simulation, with physically motivated Dirichlet-Neumann boundary condition is studied in this paper. By semidiscretization in time and compactness argument, the global existence and semiclassical limit are obtained, in which semiclassical limit describes the relation between quantum and classical drift-diffusion models. Furthermore, in the case of constant doping, we prove the weak solution exponentially approaches its constant steady state as time increases to infinity.

  4. Partial Rodent Genetic Models for Bipolar Disorder

    OpenAIRE

    Chen, Guang; Henter, Ioline D.; Manji, Husseini K

    2011-01-01

    Bipolar disorder (BPD) is a complex clinical phenomenon. This episodic illness comprises at least four features/components: depression, mania, vulnerability to mood swings in euthymic BPD patients, and spontaneous cyclicity in at least some BPD patients. Currently, there is no rodent genetic model capable of encompassing the whole phenotype of BPD exists; however, recent genetic-behavioral studies have delineated partial models for some components of BPD, namely, depression, mania, and vulner...

  5. Bipolar electrochemistry for high throughput screening applications

    OpenAIRE

    Munktell, Sara

    2016-01-01

    Bipolar electrochemistry is an interesting concept for high throughput screening techniques due to the ability to induce gradients in a range of materials and their properties, such as composition, particle size, or dopant levels, among many others. One of the key advantages of the method is the ability to test, create or modify materials without the need for a direct electrical connection. In this thesis, the viability of this method has been explored for a range of possible applications, su...

  6. Bipolar Transistor Tester for Physics Lab

    CERN Document Server

    Baddi, Raju

    2012-01-01

    A very simple low cost bipolar transistor tester for physics lab is given. The proposed circuit not only indicates the type of transistor(NPN/PNP) but also indicates the terminals(emitter, base and collector) using simple dual colored(Red/Green) LEDs. Color diagrams of testing procedure have been given for easy following. This article describes the construction of this apparatus in all detail with schematic circuit diagram, circuit layout and constructional illustration.

  7. Thought Suppression in Patients With Bipolar Disorder

    OpenAIRE

    Miklowitz, David J.; Alatiq, Yousra; Geddes, John R.; Goodwin, Guy M.; Williams, J. Mark G.

    2010-01-01

    Suppression of negative thoughts has been observed under experimental conditions among patients with major depressive disorder (MDD) but has never been examined among patients with bipolar disorder (BD). Patients with BD (n = 36), patients with MDD (n = 20), and healthy controls (n = 20) completed a task that required unscrambling 6-word strings into 5-word sentences, leaving out 1 word. The extra word allowed the sentences to be completed in a negative, neutral, or “hyperpositive” (manic/goa...

  8. Bipolar Outflows and the Evolution of Stars

    OpenAIRE

    Frank, Adam

    1998-01-01

    Hypersonic bipolar outflows are a ubiquitous phenomena associated with both young and highly evolved stars. Observations of Planetary Nebulae, the nebulae surrounding Luminous Blue Variables such as $\\eta$ Carinae, Wolf Rayet bubbles, the circumstellar environment of SN 1987A and Young Stellar Objects all revealed high velocity outflows with a wide range of shapes. In this paper I review the current state of our theoretical understanding of these outflows. Beginning with Planetary Nebulae con...

  9. Paired structures and bipolar knowledge representation

    OpenAIRE

    Montero, Javier; Bustince, H.; Franco, C.; Rodríguez, Juan Tinguaro; Gómez, Daniel; Pagola, Miguel; Fernandez, Javier; Barrenechea, Edurne

    2014-01-01

    In this strictly positional paper we propose a general approach to bipolar knowledge representation, where the meaning of concepts can be modelled by examining their decomposition into opposite and neutral categories. In particular, it is the semantic relationship between the opposite categories which suggests the emergence of a paired structure and its associated type of neutrality, being there three general types of neutral categories, namely indeterminacy, ambivalence and conflict. Hence, ...

  10. Comorbidity of Asperger's syndrome and Bipolar disorder

    OpenAIRE

    Azzoni Antonella; Raja Michele

    2008-01-01

    Abstract Background and objective Asperger's Syndrome (AS) is a pervasive developmental disorder that is sometimes unrecognized, especially in the adult psychiatric setting. On the other hand, in patients with an AS diagnosis, comorbid psychiatric disorders may be unrecognized in the juvenile setting. The aim of the paper is to show and discuss some troublesome and complex problems of the management of patients with AS and comorbid Bipolar Disorder (BD). Methods The paper describes three pati...

  11. The role of the surfaces in the photon absorption in Ge nanoclusters embedded in silica

    Directory of Open Access Journals (Sweden)

    Nicotra Giuseppe

    2011-01-01

    Full Text Available Abstract The usage of semiconductor nanostructures is highly promising for boosting the energy conversion efficiency in photovoltaics technology, but still some of the underlying mechanisms are not well understood at the nanoscale length. Ge quantum dots (QDs should have a larger absorption and a more efficient quantum confinement effect than Si ones, thus they are good candidate for third-generation solar cells. In this work, Ge QDs embedded in silica matrix have been synthesized through magnetron sputtering deposition and annealing up to 800°C. The thermal evolution of the QD size (2 to 10 nm has been followed by transmission electron microscopy and X-ray diffraction techniques, evidencing an Ostwald ripening mechanism with a concomitant amorphous-crystalline transition. The optical absorption of Ge nanoclusters has been measured by spectrophotometry analyses, evidencing an optical bandgap of 1.6 eV, unexpectedly independent of the QDs size or of the solid phase (amorphous or crystalline. A simple modeling, based on the Tauc law, shows that the photon absorption has a much larger extent in smaller Ge QDs, being related to the surface extent rather than to the volume. These data are presented and discussed also considering the outcomes for application of Ge nanostructures in photovoltaics. PACS: 81.07.Ta; 78.67.Hc; 68.65.-k

  12. Crystallization of Ge2Sb2Te5 phase-change optical disk media

    Institute of Scientific and Technical Information of China (English)

    刘波; 阮昊; 干福熹

    2002-01-01

    In this paper, the crystallization behaviour of amorphous Ge2Sb2Te5 thin films is investigated using differentialscanning calorimetry), x-ray diffraction and optical transmissivity measurements. It is indicated that only the amorphousphase to face-centred-cubic phase transformation occurs during laser annealing of the normal phase-change structure,which is a benefit for raising the phase-change optical disk's carrier-to-noise ratio (CNR). For amorphous Ge2Sb2Te5thin films, the crystallization temperature is about 200℃ and the melting temperature is 546.87℃.The activationenergy for the crystallization, Ea, is 2.25eV. The crystallization dynamics for Ge2Sb2Te5 thin fihms obeys the law ofnucleation and growth reaction. The sputtered Ge2Sb2Te5 films were initialized by an initializer unit. The initializationconditions have a great effect on the reflectivity contrast of the Ge2Sb2Te5 phase-change optical disk.

  13. Olanzapine discontinuation emergent recurrence in bipolar disorder

    Directory of Open Access Journals (Sweden)

    Manu Arora

    2014-01-01

    Full Text Available Objective: The efficacy of atypical antipsychotics including olanzapine in acute treatment of manic episode has been established, whereas its role in maintenance treatment is not clear. Materials and Methods: Thirteen patients of bipolar disorder who were on regular treatment with mood stabilizer and subsequently relapsed into mania or depressive episode after discontinuation of olanzapine were studied for various socio-demographic and clinical factors using retrospective chart review. Results: There was no correlation found between the period of tapering olanzapine, time to recurrence of episode after discontinuation, and the dosage of olanzapine at the time of discontinuation. The predominant early signs of relapse after discontinuation of olanzapine included sleep disturbance (72.7%, lack of insight for change in behavior (72.7%, irritability (54.5%, and elevated mood (45.5%. Conclusion: Mood stabilizer alone as a maintenance therapy of bipolar disorder may be inadequate for long-term management. A low dose of olanzapine along with mood stabilizers might be useful for prevention of recurrence in bipolar disorder.

  14. Historical Underpinnings of Bipolar Disorder Diagnostic Criteria

    Directory of Open Access Journals (Sweden)

    Brittany L. Mason

    2016-07-01

    Full Text Available Mood is the changing expression of emotion and can be described as a spectrum. The outermost ends of this spectrum highlight two states, the lowest low, melancholia, and the highest high, mania. These mood extremes have been documented repeatedly in human history, being first systematically described by Hippocrates. Nineteenth century contemporaries Falret and Baillarger described two forms of an extreme mood disorder, with the validity and accuracy of both debated. Regardless, the concept of a cycling mood disease was accepted before the end of the 19th century. Kraepelin then described “manic depressive insanity” and presented his description of a full spectrum of mood dysfunction which could be exhibited through single episodes of mania or depression or a complement of many episodes of each. It was this concept which was incorporated into the first DSM and carried out until DSM-III, in which the description of episodic mood dysfunction was used to build a diagnosis of bipolar disorder. Criticism of this approach is explored through discussion of the bipolar spectrum concept and some recent examinations of the clinical validity of these DSM diagnoses are presented. The concept of bipolar disorder in children is also explored.

  15. Historical Underpinnings of Bipolar Disorder Diagnostic Criteria.

    Science.gov (United States)

    Mason, Brittany L; Brown, E Sherwood; Croarkin, Paul E

    2016-01-01

    Mood is the changing expression of emotion and can be described as a spectrum. The outermost ends of this spectrum highlight two states, the lowest low, melancholia, and the highest high, mania. These mood extremes have been documented repeatedly in human history, being first systematically described by Hippocrates. Nineteenth century contemporaries Falret and Baillarger described two forms of an extreme mood disorder, with the validity and accuracy of both debated. Regardless, the concept of a cycling mood disease was accepted before the end of the 19th century. Kraepelin then described "manic depressive insanity" and presented his description of a full spectrum of mood dysfunction which could be exhibited through single episodes of mania or depression or a complement of many episodes of each. It was this concept which was incorporated into the first DSM and carried out until DSM-III, in which the description of episodic mood dysfunction was used to build a diagnosis of bipolar disorder. Criticism of this approach is explored through discussion of the bipolar spectrum concept and some recent examinations of the clinical validity of these DSM diagnoses are presented. The concept of bipolar disorder in children is also explored. PMID:27429010

  16. Bipolar outflows in OH/IR stars

    CERN Document Server

    Zijlstra, A A; Hekkert, P L; Likkel, L; Comeron, F; Norris, R P; Molster, F J; Cohen, R J; Zijlstra, Albert A.

    2000-01-01

    We investigate the development of bipolar outflows during the early post-AGB evolution. A sample of ten OH/IR stars is observed at high angular resolution, including bipolar nebulae (OH231.8+4.2), bright post-AGB stars (HD 101584) and reflection nebulae (e.g. Roberts 22). The IRAS colour--colour diagram separates the sample into different types of objects. One group may contain the progenitors to the (few) extreme bipolar planetary nebulae. Two objects show colours and chemistry very similar to the planetary nebulae with late IR-[WC] stars. One object is a confirmed close binary. A model is presented consisting of an outer AGB wind which is swept up by a faster post-AGB wind, with either wind being non-spherically symetric. The interface of the two winds is shown to exhibit a linear relation between velocity and distance from the star. The OH data confirms the predicted linear velocity gradients, and reveals torus-like, uniformly expanding components. All sources are discussed in detail using optical/HST imag...

  17. Recurrence and Relapse in Bipolar Mood Disorder

    Directory of Open Access Journals (Sweden)

    S Gh Mousavi

    2004-06-01

    Full Text Available Background: Despite the effectiveness of pharmacotherapy in acute phase of bipolar mood disorder, patients often experience relapses or recurrent episodes. Hospitalization of patients need a great deal of financial and humanistic resources which can be saved through understanding more about the rate of relapse and factors affecting this rate. Methods: In a descriptive analytical study, 380 patients with bipolar disorder who were hospitalized in psychiatric emergency ward of Noor hospital, Isfahan, Iran, were followed. Each patient was considered for; the frequency of relapse and recurrence, kind of pharmachotherapy, presence of psychotherapeutic treatments, frequency of visits by psychiatrist and the rank of present episode. Results: The overall prevalence of recurrence was 42.2%. Recurrence was lower in patients using lithium carbonate or sodium valproate or combined therapy (about 40%, compared to those using carbamazepine (80%. Recurrence was higher in patients treated with only pharmacotherapy (44.5% compared to those treated with both pharmacotherapy and psychotherapy (22.2%. Patients who were visited monthy by psychiatrist had lower rate of recurrence compared to those who had irregular visits. Conclusion: The higher rate of recurrence observed in carbamazepine therapy may be due to its adverse reactions and consequently poor compliance to this drug. Lower rates of recurrence with psychotherapy and regular visits may be related to the preventive effects of these procedures and especially to the effective management of stress. Keywords: Bipolar Mood Disorder, Recurrence, Relapse.

  18. Locomotion of Amorphous Surface Robots

    Science.gov (United States)

    Bradley, Arthur T. (Inventor)

    2016-01-01

    An amorphous robot includes a compartmented bladder containing fluid, a valve assembly, and an outer layer encapsulating the bladder and valve assembly. The valve assembly draws fluid from a compartment(s) and discharges the drawn fluid into a designated compartment to displace the designated compartment with respect to the surface. Another embodiment includes elements each having a variable property, an outer layer that encapsulates the elements, and a control unit. The control unit energizes a designated element to change its variable property, thereby moving the designated element. The elements may be electromagnetic spheres with a variable polarity or shape memory polymers with changing shape and/or size. Yet another embodiment includes an elongated flexible tube filled with ferrofluid, a moveable electromagnet, an actuator, and a control unit. The control unit energizes the electromagnet and moves the electromagnet via the actuator to magnetize the ferrofluid and lengthen the flexible tube.

  19. Enhancement of the crystalline Ge film growth by inductively coupled plasma-assisted pulsed DC sputtering.

    Science.gov (United States)

    Kim, Eunkyeom; Han, Seung-Hee

    2014-11-01

    The effect of pulsed DC sputtering on the crystalline growth of Ge thin film was investigated. Ge thin films were deposited on the glass substrates using ICP-assisted pulsed DC sputtering. The Ge target was sputtered using asymmetric bipolar pulsed DC sputtering system with and without assistance of ICP source. The pulse frequency of 200 Hz and the pulse on time of 500 μsec (duty cycle = 10%) were kept during sputtering process. Crystal structures were studied from X-ray diffraction. The X-ray diffraction patterns clearly showed crystalline film structures. The Ge thin films with randomly oriented crystalline were obtained using pulsed DC sputtering without ICP, whereas they had well aligned (220) orientation crystalline using ICP source. Moreover, the combination of ICP assistance and pulsed DC sputtering enhanced the growth of crystalline Ge thin films without hydrogen and metal by in situ deposition. The structure and lattice of the films were studied from TEM images. The cross-sectional TEM images revealed the deposited Ge films with columnar structure.

  20. Suicide attempts and clinical features of bipolar patients

    OpenAIRE

    Berkol, Tonguç D.; İslam, Serkan; Kırlı, Ebru; Pınarbaşı, Rasim; Özyıldırım, İlker

    2016-01-01

    Objectives: To identify clinical predictors of suicide attempts in patients with bipolar disorder. Methods: This study included bipolar patients who were treated in the Psychiatry Department, Haseki Training and Research Hospital, Istanbul, Turkey, between 2013 and 2014; an informed consent was obtained from the participants. Two hundred and eighteen bipolar patients were assessed by using the structured clinical interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition...

  1. Undiagnosed Bipolar Disorder: New Syndromes and New Treatments

    OpenAIRE

    Glick, Ira D.

    2004-01-01

    Recent studies have indicated that bipolar disorder is more common than previously believed. The socioeconomic and personal burdens of this illness are significant, and the lifetime risk of suicide attempts by patients with bipolar II disorder is high. It is not uncommon for patients with bipolar disorder, especially those presenting with depression, to be seen first in a primary care setting; therefore, primary care physicians need to be ready to diagnose and manage patients with these menta...

  2. Sex Dependence of Cognitive Functions in Bipolar Disorder

    OpenAIRE

    Aleksandra Suwalska; Dorota Łojko

    2014-01-01

    The objective of the present study was to assess the performance of lithium treated euthymic bipolar patients in tests measuring spatial working memory (SWM), planning, and verbal fluency and to delineate the influence of gender on cognitive functioning. Fifty-nine euthymic bipolar patients, treated with lithium carbonate for at least 5 yr, were studied. Patients and controls underwent a neuropsychological assessment. Bipolar patients had significantly worse results than the healthy controls ...

  3. Commercialization of Fuel Cell Bipolar Plate Manufacturing by Electromagnetic Forming

    OpenAIRE

    Daehn, G. S.; Hatkevich, S.; Shang, J.; Wilkerson, L.

    2010-01-01

    The cost of manufacturing bipolar plates is a major component to the overall cost structure of a Proton Exchange Membrane (PEM) fuel cell stack. To achieve the commercialization of PEM fuel cells, a high volume and low cost manufacturing process for the bipolar plate must be developed. American Trim has identified high velocity electromagnetic forming as a suitable technology to manufacture metallic fuel cell bipolar plates, because of its low capital cost, flexible tooling and rapid prototyp...

  4. Perturbed reward processing in pediatric bipolar disorder: an antisaccade study

    OpenAIRE

    Mueller, Sven C; Ng, Pamela; Temple, Veronica; Hardin, Michael G.; Pine, Daniel S.; Leibenluft, Ellen; Ernst, Monique

    2010-01-01

    Pediatric bipolar disorder is a severe and impairing illness. Characterizing the impact of pediatric bipolar disorder on cognitive function might aid in understanding the phenomenology of the disorder. While previous studies of pediatric bipolar disorder have reported deficits in cognitive control and reward behavior, little is understood about how affective processes influence behavioral control. Relative to prior studies using manual-response paradigms, eye movement tasks provide a more pre...

  5. Bipolar Bozukluk Obsesif Kompulsif Bozukluk Birlikteliği

    OpenAIRE

    Necla Keskin; Lut Tamam

    2014-01-01

    The comorbidity of bipolar disorder and anxiety disorders is a well known concept. Obsessive-compulsive disorder is the most commonly seen comorbid anxiety disorder in bipolar patients. Some genetic variants, neurotransmitters especially serotonergic systems and second-messenger systems are thought to be responsible for its etiology. Bipolar disorder alters the clinical aspects of obsessive compulsive disorder and is associated with poorer outcome. The determination of comorbidity between bip...

  6. Quetiapine: A Pharmacoeconomic Review of its Use in Bipolar Disorder

    OpenAIRE

    Greg L. Plosker

    2012-01-01

    This article briefly summarizes the burden of bipolar disorder and the clinical profile of quetiapine (Seroquel) in the management of bipolar disorder, followed by a detailed review of pharmacoeconomic analyses. Quetiapine is an atypical antipsychotic that is available in numerous countries as immediate-release and extended-release tablets for the treatment of major psychiatric disorders, including bipolar disorder. Randomized, double-blind, placebo-controlled trials with quetiapine have demo...

  7. Binary hypotheses for bipolar mass loss in transients

    OpenAIRE

    Fitzpatrick, Benedict John Russell; Podsiadlowski, Philipp

    2012-01-01

    We investigate binary hypotheses for the formation of bipolar nebulae using the smoothed particle hydrodynamics code Gadget-2. In the general case, we present a parameter study of mass loss from very simple common envelope models, which seems to show a strongly bipolar trend for sufficiently oblate envelopes and low enough spiral-in injection energy. The density profiles of the envelopes produce differing structure within the ejecta. We also investigate 3 specific bipolar ma...

  8. Cognitive impairment in manic bipolar patients: important, understated, significant aspects

    OpenAIRE

    Vrabie, Mădălina; Marinescu, Victor; Talaşman, Anca; Tăutu, Oana; Drima, Eduard; Micluţia, Ioana

    2015-01-01

    Background Bipolar disorder is a chronic mood disorder with episodic progress and high relapse rate. Growing evidence suggests that individuals with bipolar disorder display cognitive impairment which persists even throughout periods of symptom's remission. Method 137 bipolar patients met the inclusion criteria (depressive episode: DSM-IV-TR criteria for major depressive episode, HAMD score ≥17; manic/hypomanic episode: DSM-IV-TR criteria for manic/hypomanic episode, YMRS score ≥12, euthymic:...

  9. Symptom severity of bipolar disorder during the menopausal transition

    OpenAIRE

    Marsh, Wendy K.; Gershenson, Bernice; Rothschild, Anthony J.

    2015-01-01

    Background Little is known about the mood symptom experience of women with bipolar disorder during the menopausal transition (MT). Yet times of rapid hormonal decline, such as the postpartum, are associated with increased risk of severe mood episodes in bipolar disorder, and the MT is a time of increased risk for unipolar depression in women with or without a history of depression. Methods Enrollment included 56 women 40–60 years old diagnosed in the bipolar spectrum who were experiencing men...

  10. Altered Neurochemical Ingredient of Hippocampus in Patients with Bipolar Depression

    OpenAIRE

    Murad Atmaca; Hanefi Yildirim

    2012-01-01

    Background. In a number of investigations, hippocampal neurochemicals were evaluated in the patients with bipolar disorder who were on their first episode or euthymic periods. However, we did not meet any investigation in which only patients with bipolar depression were examined. As a consequence, the objective of the present study was to examine both sides of hippocampus of patients with bipolar disorder in depressive episode and healthy controls using 1H-MRS. Methods. Thirteen patients with...

  11. Treating bipolar disorder. Evidence-based guidelines for family medicine.

    OpenAIRE

    McIntyre, Roger S; Mancini, Deborah A.; Lin, Peter; Jordan, John

    2004-01-01

    OBJECTIVE: To provide an evidence-based summary of medications commonly used for bipolar disorders and a practical approach to managing bipolar disorders in the office. QUALITY OF EVIDENCE: Articles from 1990 to 2003 were selected from MEDLINE using the key words "bipolar disorder," "antiepileptics," "antipsychotics," "antidepressants," and "mood stabilizers." Good-quality evidence for many of these treatments comes from randomized trials. Lithium, divalproex, carbamazepine, lamotrigine, oxca...

  12. Bipolar disorder and metabolic syndrome: a systematic review

    OpenAIRE

    Letícia Czepielewski; Ledo Daruy Filho; Elisa Brietzke; Rodrigo Grassi-Oliveira

    2013-01-01

    OBJECTIVE: Summarize data on metabolic syndrome (MS) in bipolar disorder (BD). METHODS: A systematic review of the literature was conducted using the Medline, Embase and PsycInfo databases, using the keywords "metabolic syndrome", "insulin resistance" and "metabolic X syndrome" and cross-referencing them with "bipolar disorder" or "mania". The following types of publications were candidates for review: (i) clinical trials, (ii) studies involving patients diagnosed with bipolar disorder or (ii...

  13. The Neurobiology of Bipolar Disorder: An Integrated Approach

    OpenAIRE

    Muneer, Ather

    2016-01-01

    Bipolar disorder is a heterogeneous condition with myriad clinical manifestations and many comorbidities leading to severe disabilities in the biopsychosocial realm. The objective of this review article was to underline recent advances in knowledge regarding the neurobiology of bipolar disorder. A further aim was to draw attention to new therapeutic targets in the treatment of bipolar disorder. To accomplish these goals, an electronic search was undertaken of the PubMed database in August 201...

  14. Broadening the diagnosis of bipolar disorder: benefits vs. risks

    OpenAIRE

    Strakowski, Stephen M.; Fleck, David E.; MAJ, MARIO

    2011-01-01

    There is considerable debate over whether bipolar and related disorders that share common signs and symptoms, but are currently defined as distinct clinical entities in DSM-IV and ICD-10, may be better characterized as falling within a more broadly defined “bipolar spectrum”. With a spectrum view in mind, the possibility of broadening the diagnosis of bipolar disorder has been proposed. This paper discusses some of the rationale for an expanded diagnostic scheme from both cl...

  15. The Bipolar Interactive Psychoeducation (BIPED) study: trial design and protocol

    OpenAIRE

    Jones Ian; Craddock Nick; Cohen David; Hood Kerry; Griffiths Emily; Barnes Emma; Simpson Sharon; Smith Daniel J

    2009-01-01

    Abstract Background Bipolar disorders affect between 3–5% of the population and are associated with considerable lifelong impairment. Since much of the morbidity associated with bipolar disorder is caused by recurrent depressive symptoms, which are often only poorly responsive to antidepressants, there is a need to develop alternative, non-pharmacological interventions. Psychoeducational interventions have emerged as promising long-term therapeutic options for bipolar disorder. Methods/design...

  16. Characteristics of Sn segregation in Ge/GeSn heterostructures

    International Nuclear Information System (INIS)

    We report an investigation of Sn segregation in Ge/GeSn heterostructures occurred during the growth by molecular beam epitaxy. The measured Sn profile in the Ge layer shows that: (a) the Sn concentration decreases rapidly near the Ge/GeSn interface, and (b) when moving away from the interface, the Sn concentration reduced with a much slower rate. The 1/e decay lengths of the present system are much longer than those of the conventional group IV system of Ge segregation in the Si overlayer because of the smaller kinetic potential as modeled by a self-limited two-state exchange scheme. The demonstration of the Sn segregation shows the material characteristics of the heterostructure, which are needed for the investigation of its optical properties.

  17. Phonons in Ge/Si superlattices with Ge quantum dots

    CERN Document Server

    Milekhin, A G; Pchelyakov, O P; Schulze, S; Zahn, D R T

    2001-01-01

    Ge/Si superlattices with Ge quantum dots obtained by means of molecular-beam epitaxy were investigated by means of light Raman scattering under resonance conditions. These structures are shown to have oscillation properties of both two-dimensional and zero-dimensional objects. Within spectrum low-frequency range one observes twisted acoustic phonons (up to 15 order) typical for planar superlattices. Lines of acoustic phonons are overlapped with a wide band of continuous emission. Analysis of frequencies of Ge and Ge-Si optical phonons shows that Ge quantum dots are pseudoamorphous ones and mixing of Ge and Si atoms is a negligible one. One detected low-frequency shift of longitudinal optical phonons at laser excitation energy increase (2.54-2.71 eV)

  18. Birth of cone bipolar cells, but not rod bipolar cells, is associated with existing RGCs.

    Directory of Open Access Journals (Sweden)

    Ling Bai

    Full Text Available Retinal ganglion cells (RGCs play important roles in retinogenesis. They are required for normal retinal histogenesis and retinal cell number balance. Developmental RGC loss is typically characterized by initial retinal neuronal number imbalance and subsequent loss of retinal neurons. However, it is not clear whether loss of a specific non-RGC cell type in the RGC-depleted retina is due to reduced cell production or subsequent degeneration. Taking advantage of three knockout mice with varying degrees of RGC depletion, we re-examined bipolar cell production in these retinas from various aspects. Results show that generation of the cone bipolar cells is correlated with the existing number of RGCs. However, generation of the rod bipolar cells is unaffected by RGC shortage. Results report the first observation that RGCs selectively influence the genesis of subsequent retinal cell types.

  19. Birth of cone bipolar cells, but not rod bipolar cells, is associated with existing RGCs.

    Science.gov (United States)

    Bai, Ling; Kiyama, Takae; Li, Hongyan; Wang, Steven W

    2014-01-01

    Retinal ganglion cells (RGCs) play important roles in retinogenesis. They are required for normal retinal histogenesis and retinal cell number balance. Developmental RGC loss is typically characterized by initial retinal neuronal number imbalance and subsequent loss of retinal neurons. However, it is not clear whether loss of a specific non-RGC cell type in the RGC-depleted retina is due to reduced cell production or subsequent degeneration. Taking advantage of three knockout mice with varying degrees of RGC depletion, we re-examined bipolar cell production in these retinas from various aspects. Results show that generation of the cone bipolar cells is correlated with the existing number of RGCs. However, generation of the rod bipolar cells is unaffected by RGC shortage. Results report the first observation that RGCs selectively influence the genesis of subsequent retinal cell types.

  20. Effect of Annealing Temperature on the Microstructure and Resistivity of Ge2Sb2Te5 Films

    Institute of Scientific and Technical Information of China (English)

    LIU Bo; SONG Zhi-Tang; FENG Song-Lin; CHEN Bomy

    2004-01-01

    @@ The effect of annealing temperature on crystallization of amorphous Ge2Sb2 Te5 films with thickness of 40 nm is studied by TEM and AFM methods. The relationship between microstructure and resistivity of the Ge2Sb2 Te5film is investigated. From the TEM measurements, the grain size of crystallites increases gradually as the annealing temperature increases. When the annealing temperature is too high, voids are formed, which may originate from evaporation of the Ge2Sb2 Te5 film at the elevated temperatures, formation of sink, being nucleated by residual vacancies, and surface roughness. The resistivity of the Ge2Sb2 Te5 film decreases with the increasing annealing temperature and has slight changes when the temperature is higher than 400 ℃. Phase transitions and scattering of crystallite boundaries may be the major factors affecting the resistivity of the Ge2Sb2 Te5 film.

  1. RBS-study of GexSi1-x Compounds Formed by Variable Dose Ge Implantation into Si Wafers

    Directory of Open Access Journals (Sweden)

    Ramírez A.

    2002-01-01

    Full Text Available Amorphous and relaxed epitaxial GeSi films are prepared by Ge-implantation into Si(111 wafers of both 60 keV and 200 keV energetic Ge+-ions with appropriate dose, followed by post-implantation thermal annealing, comprising a single final annealing at a temperature of 900 °C. The implantation dose was varied between 10(14 and 10(17 atoms cm-2. Rutherford backscattering (RBS and channeling analysis was applied in order to explore the formation of a single crystalline Si-Ge compound layer, both prior and after the thermal treatment. The depth and the thickness of the implanted layer, as well as their molar composition and crystalline quality was determined, and it was found that a single crystalline Si-Ge alloy layer was created, with both depth and mole fraction depending on the ion energy and the ion dose.

  2. Oscillation of coercivity between positive and negative in MnxGe1-x∶H ferromagnetic semiconductor films

    Institute of Scientific and Technical Information of China (English)

    Qin Yu-Feng; Yan Shi-Shen; Xiao Shu-Qin; Li Qiang; Dai Zheng-Kun; Shen Ting-Ting; Yang Ai-Chun

    2013-01-01

    Amorphous MnxGe1-x∶H ferromagnetic semiconductor films prepared in mixed Ar with 20% H2 by magnetron cosputtering show global ferromagnetism with positive coercivity at low temperatures.With increasing temperature,the coercivity of MnxGe1-x:H films first changes from positive to negative,and then back to positive again,which was not found in the corresponding MnxGe1-x and other ferromagnetic semiconductors before.For Mn0.4Ge0.6∶H film,the inverted Hall loop is also observed at 30 K,which is consistent with the negative coercivity.The negative coercivity is explained by the antiferromagnetic exchange coupling between the H-rich ferromagnetic regions separated by the H-poor non-ferromagnetic spacers.Hydrogenation is a useful method to tune the magnetic properties of MnxGe1-x films for the application in spintronics.

  3. State-related alterations of gene expression in bipolar disorder

    DEFF Research Database (Denmark)

    Munkholm, Klaus; Vinberg, Maj; Berk, Michael;

    2012-01-01

    Munkholm K, Vinberg M, Berk M, Kessing LV. State-related alterations of gene expression in bipolar disorder: a systematic review. Bipolar Disord 2012: 14: 684-696. © 2012 The Authors. Journal compilation © 2012 John Wiley & Sons A/S. Objective:  Alterations in gene expression in bipolar disorder...... on comprehensive database searches for studies on gene expression in patients with bipolar disorder in specific mood states, was conducted. We searched Medline, Embase, PsycINFO, and The Cochrane Library, supplemented by manually searching reference lists from retrieved publications. Results:  A total of 17...

  4. Modeling of single-event upset in bipolar integrated circuits

    Science.gov (United States)

    Zoutendyk, J. A.

    1983-01-01

    The results of work done on the quantitative characterization of single-event upset (SEU) in bipolar random-access memories (RAMs) have been obtained through computer simulation of SEU in RAM cells that contain circuit models for bipolar transistors. The models include current generators that emulate the charge collected from ion tracks. The computer simulation results are compared with test data obtained from a RAM in a bipolar microprocessor chip. This methodology is applicable to other bipolar integrated circuit constructions in addition to RAM cells.

  5. Micro- and macro-structure of implantation-induced disorder in Ge

    CERN Document Server

    Glover, C J; Byrne, A P; Yu, K M; Foran, G J; Clerc, C; Hansen, J L; Nylandsted-Larsen, A

    2000-01-01

    The structure of ion implantation-induced damage in Ge substrates has been investigated with a combination of ion- and photon-based techniques including Rutherford backscattering spectrometry (RBS), perturbed angular correlation (PAC) and extended X-ray absorption fine structure (EXAFS) spectroscopy. For MeV Ge ion implantation at -196 degrees C, the dose dependence of the decrease in local atomic order, determined from EXAFS and PAC, was compared to the number of displaced atoms determined from RBS measurements. An EXAFS determined damage fraction was shown to be a better estimate of amorphous fraction than the number of displaced atoms. PAC was used to elucidate the evolution of defective configurations, and was compared to the RBS and EXAFS results. A fit to the overlap model with the overlap of two ion cascades for complete amorphization best described the experimental results. (16 refs).

  6. Antidepressants for bipolar disorder: A meta-analysis of randomized, double-blind, controlled trials

    OpenAIRE

    Zhang, Yingli; Yang, Huan; Yang, Shichang; Liang, Wei; DAI, Ping; Wang, Changhong; Zhang, Yalin

    2013-01-01

    OBJECTIVE: To examine the efficacy and safety of short-term and long-term use of antidepressants in the treatment of bipolar disorder. DATA SOURCES: A literature search of randomized, double-blind, controlled trials published until December 2012 was performed using the PubMed, ISI Web of Science, Medline and Cochrane Central Register of Controlled Trials databases. The keywords “bipolar disorder, bipolar I disorder, bipolar II disorder, bipolar mania, bipolar depression, cyclothymia, mixed ma...

  7. The Mood Disorder Questionnaire: A Simple, Patient-Rated Screening Instrument for Bipolar Disorder

    OpenAIRE

    Hirschfeld, Robert M. A.

    2002-01-01

    Bipolar disorder is frequently encountered in primary care settings, often in the form of poor response to treatment for depression. Although lifetime prevalence of bipolar I disorder is 1%, the prevalence of bipolar spectrum disorders (e.g., bipolar I, bipolar II, and cyclothymia) is much higher, especially among patients with depression. The consequences of misdiagnosis can be devastating. One way to improve recognition of bipolar spectrum disorders is to screen for them. The Mood Disorder ...

  8. Transtorno afetivo bipolar: um enfoque transcultural Transcultural aspects of bipolar disorder

    OpenAIRE

    Marsal Sanches; Miguel Roberto Jorge

    2004-01-01

    Considerando-se que existem diferenças importantes na maneira como as emoções são vivenciadas e expressas em diferentes culturas, a apresentação e o manejo do transtorno afetivo bipolar sofrem influência de fatores culturais. O presente artigo realiza uma breve revisão da evidência referente aos aspectos transculturais do transtorno bipolar.Cultural variations in the expression of emotions have been described. Consequently, there are cross-cultural influences on the diagnosis and management o...

  9. Abordagens psicoterápicas no transtorno bipolar Psychoterapeutic approach in bipolar disorder

    OpenAIRE

    Paulo Knapp; Luciano Isolan

    2005-01-01

    Embora o tratamento farmacológico seja essencial para o tratamento do transtorno bipolar, apenas 40% de todos os pacientes que aderem às medicações permanecem assintomáticos durante o período de seguimento, o que tem levado ao desenvolvimento de intervenções psicoterápicas associadas. O objetivo deste artigo é examinar as evidências atuais da eficácia de intervenções psicoterápicas no tratamento do transtorno bipolar. Foi realizada uma pesquisa bibliográfica por meio do MedLine, PsychoINFO, L...

  10. Bipolar disorder and age-related functional impairment Prejuízo funcional associado à idade e transtorno bipolar

    Directory of Open Access Journals (Sweden)

    Alice Aita Cacilhas

    2009-12-01

    Full Text Available OBJECTIVE: Although bipolar disorder is a major contributor to functional impairment worldwide, an independent impact of bipolar disorder and ageing on functioning has yet to be demonstrated. The objective of the present study was to evaluate the effect of bipolar disorder on age-related functional status using matched controls as a standard. METHOD: One-hundred patients with bipolar disorder and matched controls were evaluated for disability. Age-related effects controlled for confounders were cross-sectionally evaluated. RESULTS: Patients were significantly more impaired than controls. Regression showed effects for aging in both groups. The effect, size, however, was significantly stronger in patients. CONCLUSION: Bipolar disorder was an important effect modifier of the age impact on functioning. While a longitudinal design is needed to effectively demonstrate this different impact, this study further depicts bipolar disorder as a chronic and progressively impairing illness.OBJETIVO: O transtorno bipolar é responsável por importante parcela do prejuízo funcional ao redor do mundo. Um efeito independente do transtorno bipolar e da idade no funcionamento ainda não foi demonstrado. O presente estudo tem o objetivo de avaliar o efeito do transtorno bipolar no prejuízo funcional relacionado à idade, com controles pareados como padrão. MÉTODO: Cem pacientes com transtorno bipolar e controles pareados foram avaliados para incapacidade. Efeitos relacionados à idade, com controle para confundidores, foram investigados. RESULTADOS: Pacientes tiveram significativamente mais prejuízo que controles. A regressão mostrou efeito para a idade em ambos os grupos, e o efeito foi significativamente mais forte nos pacientes. CONCLUSÃO: O transtorno bipolar foi um importante modificador de efeito no impacto da idade no funcionamento. Enquanto um desenho de estudo longitudinal é necessário para efetivamente demonstrar este impacto diferencial, este

  11. Feedforward lateral inhibition in retinal bipolar cells: input-output relation of the horizontal cell-depolarizing bipolar cell synapse.

    OpenAIRE

    Yang, X. L.; S. M. Wu

    1991-01-01

    Lateral inhibition is the ubiquitous strategy used by visual neurons for spatial resolution throughout the animal kingdom. It has been a puzzle whether lateral inputs in retinal bipolar cells are mediated by the horizontal cell (HC)-cone feedback synapse, by the HC-bipolar cell feedforward synapse, or by both. By blocking the central inputs of the depolarizing bipolar cells (DBCs) with L-2-amino-4-phosphonobutyrate, we were able to eliminate the contribution of the feedback synapse and to dem...

  12. Comparing clinical responses and the biomarkers of BDNF and cytokines between subthreshold bipolar disorder and bipolar II disorder

    OpenAIRE

    Tzu-Yun Wang; Sheng-Yu Lee; Shiou-Lan Chen; Yun-Hsuan Chang; Liang-Jen Wang; Po See Chen; Shih-Heng Chen; Chun-Hsien Chu; San-Yuan Huang; Nian-Sheng Tzeng; Chia-Ling Li; Yi-Lun Chung; Tsai-Hsin Hsieh; I Hui Lee; Kao Chin Chen

    2016-01-01

    Patients with subthreshold hypomania (SBP; subthreshold bipolar disorder) were indistinguishable from those with bipolar disorder (BP)-II on clinical bipolar validators, but their analyses lacked biological and pharmacological treatment data. Because inflammation and neuroprogression underlies BP, we hypothesized that cytokines and brain-derived neurotrophic factor (BDNF) are biomarkers for BP. We enrolled 41 drug-naïve patients with SBP and 48 with BP-II undergoing 12 weeks of pharmacologica...

  13. Quantification of surface amorphous content using dispersive surface energy: the concept of effective amorphous surface area.

    Science.gov (United States)

    Brum, Jeffrey; Burnett, Daniel

    2011-09-01

    We investigate the use of dispersive surface energy in quantifying surface amorphous content, and the concept of effective amorphous surface area is introduced. An equation is introduced employing the linear combination of surface area normalized square root dispersive surface energy terms. This equation is effective in generating calibration curves when crystalline and amorphous references are used. Inverse gas chromatography is used to generate dispersive surface energy values. Two systems are investigated, and in both cases surface energy data collected for physical mixture samples comprised of amorphous and crystalline references fits the predicted response with good accuracy. Surface amorphous content of processed lactose samples is quantified using the calibration curve, and interpreted within the context of effective amorphous surface area. Data for bulk amorphous content is also utilized to generate a thorough picture of how disorder is distributed throughout the particle. An approach to quantifying surface amorphous content using dispersive surface energy is presented. Quantification is achieved by equating results to an effective amorphous surface area based on reference crystalline, and amorphous materials. PMID:21725707

  14. In-situ characterization of the optical and electronic properties in GeTe and GaSb thin films

    Energy Technology Data Exchange (ETDEWEB)

    Velea, A.; Popescu, M.; Galca, A. C., E-mail: ac-galca@infim.ro [National Institute of Materials Physics, Atomistilor 105 bis, RO-077125 Magurele, Ilfov (Romania); Socol, G. [National Institute for Laser, Plasma and Radiation Physics, Atomistilor 409, RO-077125 Magurele, Ilfov (Romania)

    2015-10-07

    GeTe and GaSb thin films obtained by pulsed laser deposition were investigated by spectroscopic ellipsometry at controlled temperatures. The GeTe films were fully amorphous, while the GaSb films were partially crystalized in the as-deposited state. The Tauc-Lorentz model was employed to fit the experimental data. From the temperature study of the optical constants, it was observed the crystallization in the 150–160 °C range of GeTe amorphous films and between 230 and 240 °C of GaSb amorphous phase. A second transition in the resonance energy and the broadening parameter of the Lorentz oscillator was observed due to the crystallization of Sb after 250 °C. The temperatures of 85 °C and 130 °C are noticed as the start of the relaxation of the amorphous GeTe phase and as-deposited GaSb. The peaks of the imaginary part of the dielectric function red shifted after the phase change, while the variation with temperature of the crystalline phase follows the Varshni law. The electron-phonon coupling constants are 2.88 and 1.64 for c-GeTe and c-GaSb, respectively. An optical contrast up to 60% was obtained for GeTe films and a maximum value of 7.5% is revealed in the case GaSb, which is altered by the partial crystallinity of the as-deposited films.

  15. A positron source using an axially oriented crystal associated to a granular amorphous converter

    Institute of Scientific and Technical Information of China (English)

    XU Cheng-Hai; Robert Chehab; Peter Sievers; Xavier Artru; Michel Chevallier; Olivier Dadoun; PEI Guo-Xi; Vladimir M. Strakhovenko; Alessandro Variola

    2012-01-01

    A non-conventional positron source using the intense γ radiation from an axially oriented monocrystal which materializes into e+e- pairs in a granular amorphous converter is described.The enhancement of photon radiation by multi-GeV electrons crossing a tungsten crystal along its 〈111〉 axis is reported.The resulting enhancement of pair production in an amorphous converter placed 2 meters downstream,is also reported.Sweeping off the charged particles from the crystal by a bending magnet upstream of the converter allows a significant reduction of the deposited energy density.Substituting a granular target made of small spheres for the usual compact one,makes the energy dissipation easier.The deposited energy and corresponding heating are analyzed and solutions for cooling are proposed.The configurations studied here for this kind of positron source allow its consideration for unpolarized positrons for the ILC.

  16. A positron source using an axially oriented crystal associated to a granular amorphous converter

    CERN Document Server

    Xu, Cheng-Hai; Sievers, Peter; Artru, Xavier; Chevallier, Michel; Dadoun, Olivier; Pei, Guo-Xi; Strakhovenko, Vladimir M; Variola, Alessandro

    2012-01-01

    A non-conventional positron source using the intense l radiation from an axially oriented monocrystal which materializes into e(+)e(-') pairs in a granular amorphous converter is described. The enhancement of photon radiation by multi-GeV electrons crossing a tungsten crystal along its axis is reported. The resulting enhancement of pair production in an amorphous converter placed 2 meters downstream, is also reported. Sweeping off the charged particles from the crystal by a bending magnet upstream of the converter allows a significant reduction of the deposited energy density. Substituting a granular target made of small spheres for the usual compact one, makes the energy dissipation easier. The deposited energy and corresponding heating are analyzed and solutions for cooling are proposed. The configurations studied here for this kind of positron source allow its consideration for unpolarized positrons for the ILC.

  17. Competing covalent and ionic bonding in Ge-Sb-Te phase change materials

    OpenAIRE

    Mukhopadhyay, S.; Sun, J.; A. Subedi; Siegrist, T.; Singh, D.

    2016-01-01

    Ge2Sb2Te5 and related phase change materials are highly unusual in that they can be readily transformed between amorphous and crystalline states using very fast melt, quench, anneal cycles, although the resulting states are extremely long lived at ambient temperature. These states have remarkably different physical properties including very different optical constants in the visible in strong contrast to common glass formers such as silicates or phosphates. This behavior has been described in...

  18. [Confusing clinical presentations and differential diagnosis of bipolar disorder].

    Science.gov (United States)

    Gorwood, P

    2004-01-01

    An early recognition of bipolar disorders may have an important impact on the prognosis of this disorder according to different mechanisms. Bipolar disorder is nevertheless not easy to detect, the diagnosis being correctly proposed after, in average more than a couple of Years and three different doctors assessments. A short delay before introducing the relevant treatment should help avoiding inappropriate treatments (prescribing, for example, neuroleptics for long periods, antidepressive drugs each time depressive symptoms occurs, absence of treatment despite mood disorders), with their associated negative impact such as mood-switching, rapid cycling or presence of chronic side-effects stigmates. Furthermore, non-treated mood disorders in bipolar disorder are longer, more stigmatizing and may be associated with an increased risk of suicidal behaviour and mortality. Lastly, compliance, an important factor regarding the long term prognosis of bipolar disorder, should be improved when there is a short delay between correct diagnosis and treatment and onset of the disorder. We therefore propose to review the literature for the different pitfalls involved in the diagnosis of bipolar disorder. Non-bipolar mood-disorders are frequently quoted as one of the alternative diagnosis. Hyperthymic temperament, side-effects of prescribed treatments and organic comorbid disorders may be involved. Bipolar disorders have a sex-ratio closer to 1 (men are thus more frequently of the bipolar type in mood-disorders), with earlier age at onset, and more frequent family history of suicidal attempts and bipolar disorder. Schizo-affective disorders are also a major concern regarding the diagnosis of bipolar disorder. This is explained by flat affects sometimes close to anhedonia, presence of a schizoïd personality in bipolar disorder, persecutive hostility that can be considered to be related to irritability rather than a schizophrenic symptom. Rapid cycling, mixed episodes and short

  19. High-frequency noise modeling of Si(Ge) bipolar transistors

    NARCIS (Netherlands)

    Vitale, F.

    2014-01-01

    The design and the optimization of electronic systems often requires a detailed knowledge of the inherent noise generated within semiconductor active devices, constituting the core of such systems. Examples of applications in which noise is a key issue include receiver front-ends in radiofrequency (

  20. Photonic crystals, amorphous materials, and quasicrystals

    International Nuclear Information System (INIS)

    Photonic crystals consist of artificial periodic structures of dielectrics, which have attracted much attention because of their wide range of potential applications in the field of optics. We may also fabricate artificial amorphous or quasicrystalline structures of dielectrics, i.e. photonic amorphous materials or photonic quasicrystals. So far, both theoretical and experimental studies have been conducted to reveal the characteristic features of their optical properties, as compared with those of conventional photonic crystals. In this article, we review these studies and discuss various aspects of photonic amorphous materials and photonic quasicrystals, including photonic band gap formation, light propagation properties, and characteristic photonic states. (focus issue)

  1. High mechanical endurance RRAM based on amorphous gadolinium oxide for flexible nonvolatile memory application

    Science.gov (United States)

    Zhao, Hongbin; Tu, Hailing; Wei, Feng; Shi, Zhitian; Xiong, Yuhua; Zhang, Yan; Du, Jun

    2015-05-01

    In this paper, we use amorphous Gd2O3 as the switching layer for fabricated RRAM devices with novel high performance, excellent flexibility, and mechanical endurance properties as potential candidate memory for flexible electronics applications. The obtained Cu/Gd2O3/Pt devices on flexible polyethylene terephthalate (PET) substrates show bipolar switching characteristics, low voltage operation (106 s). No performance degradation occurs, and the stored information is not lost after the device has been bent to different angles and up to 104 times in the bending tests. Based on temperature-dependent switching characteristics, the formation of Cu conducting filaments stemming from electrochemical reactions is believed to be the reason for the resistance switching from a high resistance state to a low resistance state. The studies of the integrated experiment and mechanism lay the foundation for the development of high-performance flexible RRAM.

  2. Ge/SiGe superlattices for nanostructured thermoelectric modules

    Energy Technology Data Exchange (ETDEWEB)

    Chrastina, D., E-mail: daniel@chrastina.net [L-NESS Politecnico di Milano, Polo di Como, via Anzani 42, 22100 Como (Italy); Cecchi, S. [L-NESS Politecnico di Milano, Polo di Como, via Anzani 42, 22100 Como (Italy); Hague, J.P. [Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA (United Kingdom); Frigerio, J. [L-NESS Politecnico di Milano, Polo di Como, via Anzani 42, 22100 Como (Italy); Samarelli, A.; Ferre–Llin, L.; Paul, D.J. [School of Engineering, University of Glasgow, Oakfield Avenue, Glasgow, G12 8LT (United Kingdom); Müller, E. [Electron Microscopy ETH Zurich (EMEZ), ETH-Zürich, CH-8093 (Switzerland); Etzelstorfer, T.; Stangl, J. [Institut für Halbleiter und Festkörperphysik, Universität Linz, A-4040 Linz (Austria); Isella, G. [L-NESS Politecnico di Milano, Polo di Como, via Anzani 42, 22100 Como (Italy)

    2013-09-30

    Thermoelectrics are presently used in a number of applications for both turning heat into electricity and also for using electricity to produce cooling. Mature Si/SiGe and Ge/SiGe heteroepitaxial growth technology would allow highly efficient thermoelectric materials to be engineered, which would be compatible and integrable with complementary metal oxide silicon micropower circuits used in autonomous systems. A high thermoelectric figure of merit requires that electrical conductivity be maintained while thermal conductivity is reduced; thermoelectric figures of merit can be improved with respect to bulk thermoelectric materials by fabricating low-dimensional structures which enhance the density of states near the Fermi level and through phonon scattering at heterointerfaces. We have grown and characterized Ge-rich Ge/SiGe/Si superlattices for nanofabricated thermoelectric generators. Low-energy plasma-enhanced chemical vapor deposition has been used to obtain nanoscale-heterostructured material which is several microns thick. Crystal quality and strain control have been investigated by means of high resolution X-ray diffraction. High-resolution transmission electron microscopy images confirm the material and interface quality. Electrical conductivity has been characterized by the mobility spectrum technique. - Highlights: ► High-quality Ge/SiGe multiple quantum wells for thermoelectric applications ► Mobility spectra of systems featuring a large number of parallel conduction channels ► Competitive thermoelectric properties measured in single devices.

  3. Bipolar disorder and multiple sclerosis Transtorno bipolar e esclerose múltipla

    Directory of Open Access Journals (Sweden)

    Mariana Inés Ybarra

    2007-12-01

    Full Text Available Bipolar disorder may be overrepresented in multiple sclerosis (MS patients. Although research in this area is limited, studies assessing the nature of this association have focused on genetic aspects, adverse reaction to drugs and brain demyelinating lesions. Herein we report three patients with MS that also presented bipolar disorder. The coexistence of neurological and psychiatric symptoms in most MS relapses highlights the relevance of biological factors in the emergence of mood disorders in these patients.O transtorno bipolar do humor parece estar super-representado em pacientes com esclerose múltipla (EM. Apesar de a pesquisa nessa área ser limitada, estudos acerca da natureza dessa associação têm se concentrado em aspectos genéticos, reações adversas a drogas e lesões desmielinizantes no sistema nervoso central. Relatamos, aqui, três casos de pacientes com EM que também apresentaram transtorno bipolar do humor. A coexistência de sintomas neurológicos e psiquiátricos em grande parte das recaídas de EM reforça a importância de fatores biológicos na gênese dos sintomas afetivos nesses pacientes.

  4. Neurocognitive profiles in treatment-resistant bipolar I and bipolar II disorder depression

    OpenAIRE

    Kessler, Ute; Schøyen, Helle Kristine; Andreassen, Ole Andreas; Eide, Geir Egil; Hammar, Åsa; Malt, Ulrik Fredrik; Ødegaard, Ketil Joachim; Morken, Gunnar; Sundet, Kjetil Søren; Vaaler, Arne Einar

    2013-01-01

    Background The literature on the neuropsychological profiles in Bipolar disorder (BD) depression is sparse. The aims of the study were to assess the neurocognitive profiles in treatment-resistant, acutely admitted BD depression inpatients, to compare the neurocognitive functioning in patients with BD I and II, and to identify the demographic and clinical illness characteristics associated with cognitive functioning. Met...

  5. Corrosion resistant amorphous metals and methods of forming corrosion resistant amorphous metals

    Science.gov (United States)

    Farmer, Joseph C.; Wong, Frank M.G.; Haslam, Jeffery J.; Yang, Nancy; Lavernia, Enrique J.; Blue, Craig A.; Graeve, Olivia A.; Bayles, Robert; Perepezko, John H.; Kaufman, Larry; Schoenung, Julie; Ajdelsztajn, Leo

    2014-07-15

    A system for coating a surface comprises providing a source of amorphous metal, providing ceramic particles, and applying the amorphous metal and the ceramic particles to the surface by a spray. The coating comprises a composite material made of amorphous metal that contains one or more of the following elements in the specified range of composition: yttrium (.gtoreq.1 atomic %), chromium (14 to 18 atomic %), molybdenum (.gtoreq.7 atomic %), tungsten (.gtoreq.1 atomic %), boron (.ltoreq.5 atomic %), or carbon (.gtoreq.4 atomic %).

  6. Surface Acidity of Amorphous Aluminum Hydroxide

    Institute of Scientific and Technical Information of China (English)

    K. FUKUSHI; K. TSUKIMURA; H. YAMADA

    2006-01-01

    The surface acidity of synthetic amorphous Al hydroxide was determined by acid/base titration with several complementary methods including solution analyses of the reacted solutions and XRD characterization of the reacted solids. The synthetic specimen was characterized to be the amorphous material showing four broad peaks in XRD pattern. XRD analyses of reacted solids after the titration experiments showed that amorphous Al hydroxide rapidly transformed to crystalline bayerite at the alkaline condition (pH>10). The solution analyses after and during the titration experiments showed that the solubility of amorphous aluminum hydroxide, Ksp =aAl3+/a3H+,was 1010.3,The amount of consumption of added acid or base during the titration experiment was attributed to both the protonation/deprotonation of dissolved Al species and surface hydroxyl group. The surface acidity constants, surface hydroxyl density and specific surface area were estimated by FITEQL 4.0.

  7. LOCAL ATOMIC STRUCTURE OF AMORPHOUS METALS

    OpenAIRE

    Egami, T.; Maed, K.; Srolovitz, D.; Vitek, V.

    1980-01-01

    The local parameters are introduced to describe the local atomic structure of amorphous metals. They define the structural defects which facilitate the explanation of various properties, including the volume change by annealing.

  8. New types of bipolar fuzzy sets in -semihypergroups

    Directory of Open Access Journals (Sweden)

    Naveed Yaqoob

    2016-04-01

    Full Text Available The notion of bipolar fuzzy set was initiated by Lee (2000 as a generalization of the notion fuzzy sets and intuitionistic fuzzy sets, which have drawn attention of many mathematicians and computer scientists. In this paper, we initiate a study on bipolar ( , -fuzzy sets in -semihypergroups. By using the concept of bipolar ( , -fuzzy sets (Yaqoob and Ansari, 2013, we introduce the notion of bipolar ( , -fuzzy sub -semihypergroups (-hyperideals and bi--hyperideals and discuss some basic results on bipolar ( , -fuzzy sets in -semihypergroups. Furthermore, we define the bipolar fuzzy subset ,               and prove that if  ,       is a bipolar ( , -fuzzy sub -semihypergroup (resp., -hyperideal and bi--hyperideal of H; then ,               is also a bipolar ( , -fuzzy sub -semihypergroup (resp., -hyperideal and bi--hyperideal of H.

  9. Cognitive-Behavioral Therapy for Rapid Cycling Bipolar Disorder

    Science.gov (United States)

    Reilly-Harrington, Noreen A.; Knauz, Robert O.

    2005-01-01

    This article describes the application of cognitive-behavioral therapy (CBT) to the treatment of rapid cycling bipolar disorder. Between 10% and 24% of bipolar patients experience a rapid cycling course, with 4 or more mood episodes occurring per year. Characterized by nonresponse to standard mood-stabilizing medications, rapid cyclers are…

  10. Polygenic risk scores for schizophrenia and bipolar disorder predict creativity

    NARCIS (Netherlands)

    Power, R.A.; Steinberg, S.; Bjornsdottir, G.; Rietveld, C.A.; Abdellaoui, A.; Nivard, M.M.; Johannesson, M.; Galesloot, T.E.; Hottenga, J.J.; Willemsen, G.; Cesarini, D.; Benjamin, D.J.; Magnusson, P.K.; Ullen, F.; Tiemeier, H.; Hofman, A.; Rooij, F.J. van; Walters, G.B.; Sigurdsson, E.; Thorgeirsson, T.E.; Ingason, A.; Helgason, A.; Kong, A.; Kiemeney, B.; Koellinger, P.; Boomsma, D.I.; Gudbjartsson, D.; Stefansson, H.; Stefansson, K.

    2015-01-01

    We tested whether polygenic risk scores for schizophrenia and bipolar disorder would predict creativity. Higher scores were associated with artistic society membership or creative profession in both Icelandic (P = 5.2 x 10(-6) and 3.8 x 10(-6) for schizophrenia and bipolar disorder scores, respectiv

  11. Bipolar-FET combinational power transistors for power conversion applications

    Science.gov (United States)

    Chen, D. Y.; Chin, S. A.

    1984-01-01

    Four bipolar-FET (field-effect transistor) combinational transistor configurations are compared from the application point of view. The configurations included are FET-Darlington (cascade), emitter-open switch (cascode), parallel configuration, and FET-gated bipolar transistors (FGT).

  12. Mechanisms of Centrosome Separation and Bipolar Spindle Assembly

    NARCIS (Netherlands)

    Tanenbaum, Marvin E.; Medema, Rene H.

    2010-01-01

    Accurate segregation of chromosomes during cell division is accomplished through the assembly of a bipolar microtubule-based structure called the mitotic spindle. Work over the past two decades has identified a core regulator of spindle bipolarity, the microtubule motor protein kinesin-5. However, a

  13. Premorbid intelligence and educational level in bipolar and unipolar disorders

    DEFF Research Database (Denmark)

    Sørensen, Holger Jelling; Sæbye, Ditte; Urfer-Parnas, Annick;

    2012-01-01

    Registry-based studies have found no or weak associations between premorbid intelligence and the broad entity of affective spectrum disorder, but none of the studies compared bipolar/unipolar subgroups.......Registry-based studies have found no or weak associations between premorbid intelligence and the broad entity of affective spectrum disorder, but none of the studies compared bipolar/unipolar subgroups....

  14. Cortisol exposure, cognition and clinical course of bipolar disorder

    NARCIS (Netherlands)

    Spijker, Anne Titia

    2012-01-01

    In this dissertation, we aimed to identify the influence of cortisol exposure and cognitive performance on the clinical course of bipolar disorder. Data regarding sociodemographics, disease characteristics and genetic analysis of the cortisol receptors, were collected of 366 patients with bipolar d

  15. SEMICLASSICAL LIMIT FOR BIPOLAR QUANTUM DRIFT-DIFFUSION MODEL

    Institute of Scientific and Technical Information of China (English)

    Ju Qiangchang; Chen Li

    2009-01-01

    Semiclassical limit to the solution of transient bipolar quantum drift-diffusion model in semiconductor simulation is discussed. It is proved that the semiclassical limit ofthis solution satisfies the classical bipolar drift-diffusion model. In addition, the authors also prove the existence of weak solution.

  16. Bipolar Disorder in Children: Implications for Speech-Language Pathologists

    Science.gov (United States)

    Quattlebaum, Patricia D.; Grier, Betsy C.; Klubnik, Cynthia

    2012-01-01

    In the United States, bipolar disorder is an increasingly common diagnosis in children, and these children can present with severe behavior problems and emotionality. Many studies have documented the frequent coexistence of behavior disorders and speech-language disorders. Like other children with behavior disorders, children with bipolar disorder…

  17. The Enigma of Bipolar Disorder in Children and Adolescents

    Science.gov (United States)

    Hatchett, Gregory T.

    2009-01-01

    In the past decade, there has been a proliferation in the number of children and adolescents diagnosed with bipolar disorder. Except in rare cases, the young people who receive this diagnosis do not meet the strict diagnostic criteria for bipolar disorder I or II in the DSM-IV-TR. Many pediatric psychiatrists insist there are important development…

  18. Olfactocentric Paralimbic Cortex Morphology in Adolescents with Bipolar Disorder

    Science.gov (United States)

    Wang, Fei; Kalmar, Jessica H.; Womer, Fay Y.; Edmiston, Erin E.; Chepenik, Lara G.; Chen, Rachel; Spencer, Linda; Blumberg, Hilary P.

    2011-01-01

    The olfactocentric paralimbic cortex plays a critical role in the regulation of emotional and neurovegetative functions that are disrupted in core features of bipolar disorder. Adolescence is thought to be a critical period in both the maturation of the olfactocentric paralimbic cortex and in the emergence of bipolar disorder pathology. Together,…

  19. Pediatric Bipolar Disorder: Evidence for Prodromal States and Early Markers

    Science.gov (United States)

    Luby, Joan L.; Navsaria, Neha

    2010-01-01

    Background: Childhood bipolar disorder remains a controversial but increasingly diagnosed disorder that is associated with significant impairment, chronic course and treatment resistance. Therefore, the search for prodromes or early markers of risk for later childhood bipolar disorder may be of great importance for prevention and/or early…

  20. Bipolar Disorder: not only in the Brain - immunological aspects

    NARCIS (Netherlands)

    E.M. Knijff (Esther)

    2006-01-01

    textabstractThe main objective of this thesis was to obtain more insight in the role of the immune system in the pathogenesis of bipolar disorder by investigating various aberrancies in the immune system of patients with bipolar disorder. In Chapter 1 some general concepts, important for the per

  1. Tiagabine in treatment refractory bipolar disorder : a clinical case series

    NARCIS (Netherlands)

    Suppes, T; Chisholm, KA; Dhavale, D; Frye, MA; Atshuler, LL; McElroy, SL; Keck, PE; Nolen, WA; Kupka, R; Denicoff, KD; Leverich, GS; Rush, AJ; Post, RM

    2002-01-01

    Objectives: Anticonvulsants have provided major treatment advances for patients with bipolar disorder. Many of these drugs, including several with proven efficacy in bipolar mania or depression, enhance the activity of the gamma-amino butyric acid (GABA) neurotransmitter system. A new anticonvulsant

  2. The Ebers-Moll model for magnetic bipolar transistors

    OpenAIRE

    Fabian, J.; Zutic, I.

    2004-01-01

    The equivalent electrical circuit of the Ebers-Moll type is introduced for magnetic bipolar transistors. In addition to conventional diodes and current sources, the new circuit comprises two novel elements due to spin-charge coupling. A classification scheme of the operating modes of magnetic bipolar transistors in the low bias regime is presented.

  3. [Obesity and dyslipidemia in Tunisian bipolar subjects].

    Science.gov (United States)

    Ezzaher, Asma; Haj Mouhamed, Dhouha; Mechri, Anwar; Neffati, Fadoua; Douki, Wahiba; Gaha, Lotfi; Najjar, Mohamed Fadhel

    2010-01-01

    This study aims to investigate the prevalence of obesity and overweight and their association with lipid parameters in bipolar patients. Our study included 130 patients with bipolar disorder and 130 control subjects aged respectively 37.9 +/- 12.1 and 37.2 +/- 13.1 years. Obesity was evaluated by body mass index (BMI). Concentrations of total cholesterol, triglycerides, cLDL and cHDL were determined by enzymatic methods and ApoA1, ApoB and Lp(a) by techniques immunoturbidimetric. The prevalence of obesity in patients is 30.1% vs 12.3% in controls. A significant increase in BMI was noted in patients compared with controls regardless of sex and tobacco status and in patients aged less than 35 years and those consumers of alcohol. The majority of obese and overweight patients are treated with valproic acid. We found increase in cholesterol (4.41 +/- 1.02 vs 3.90 +/- 0.98 mmol/L), in cLDL (2.13 +/- 1.09 vs 1.29 +/- 0.56 mmol/L) and in Lp(a) (236 +/- 207 vs 163 +/- 150 mg/L) and decrease in HDLc (0.98 +/- 0.28 vs 1.09 +/- 0.36 mmol/L), more frequent at the obese patients and those presenting an overweight. In conclusion, in bipolar patients, obesity and overweight are frequent and associated with perturbations in lipid profile particularly an increase in total cholesterol, cLDL and Lp(a) and decrease in cHDL that increase the risk of cardiovascular disease. PMID:20478770

  4. Bipolar Saline TURP for Large Prostate Glands

    Directory of Open Access Journals (Sweden)

    David S. Finley

    2007-01-01

    Full Text Available The objective of this study was to evaluate the feasibility of bipolar transurethral resection of the prostate (TURP in patients with very large prostate glands and significant comorbidities. Four patients with prostate glands >160 cc on preoperative volume measurement and ASA class three or higher underwent bipolar TURP with the Gyrus PlasmaKinetic system. Preoperative, operative, and postoperative parameters were studied. The results showed an average ASA class 3.25 (range: 3–4. The average preoperative prostate volume was 207.4 cc (range: 163–268. The average preoperative International Prostate Symptom Score (IPSS and bother score was 31 and 6, respectively. Mean resection time was 163 min (range: 129–215. The weight of resected tissue and percentage of vaporized tissue was 80.8 g (range: 62–115 and 10.0% (range: 3.8–15.1, respectively. An average of 61L of saline was used (range: 48–78. The mean change in hemoglobin and serum sodium was 2.1 g/dl (range: 1.4–2.7 and 3.3 meq/l (range: 2–4, respectively. Postoperative catheter time averaged 76 h (range: 40–104. Mean length of hospital stay was 12 h (range: 4–24. The mean postoperative IPSS and bother score was 2.75 and 0.25, respectively. Bipolar TURP is a feasible alternative to simple open prostatectomy in high-risk patients with massive prostate adenomas. Prostate volume is reduced by approximately 10% due to vaporization.

  5. Emerging trends in the stabilization of amorphous drugs

    DEFF Research Database (Denmark)

    Laitinen, Riikka; Löbmann, Korbinian; Strachan, Clare J.;

    2013-01-01

    water-soluble drugs can be increased by the formation of stabilized amorphous forms. Currently, formulation as solid polymer dispersions is the preferred method to enhance drug dissolution and to stabilize the amorphous form of a drug. The purpose of this review is to highlight emerging alternative...... methods to amorphous polymer dispersions for stabilizing the amorphous form of drugs. First, an overview of the properties and stabilization mechanisms of amorphous forms is provided. Subsequently, formulation approaches such as the preparation of co-amorphous small-molecule mixtures and the use...... of mesoporous silicon and silica-based carriers are presented as potential means to increase the stability of amorphous pharmaceuticals....

  6. Laser annealing of hydrogen implanted amorphous silicon

    International Nuclear Information System (INIS)

    Amorphous silicon, prepared by silicon bombardment at energies of 200 to 250 keV, was implanted with 40 keV H2+ to peak concentrations up to 15 at .% and recrystallized in air by single 20 nsec pulses at 1.06 μm from a Nd:glass laser. Amorphous layer formation and recrystallization were verified using Raman spectroscopy and ion backscattering/channeling analysis

  7. Tests Of Amorphous-Silicon Photovoltaic Modules

    Science.gov (United States)

    Ross, Ronald G., Jr.

    1988-01-01

    Progress in identification of strengths and weaknesses of amorphous-silicon technology detailed. Report describes achievements in testing reliability of solar-power modules made of amorphous-silicon photovoltaic cells. Based on investigation of modules made by U.S. manufacturers. Modules subjected to field tests, to accelerated-aging tests in laboratory, and to standard sequence of qualification tests developed for modules of crystalline-silicon cells.

  8. Amorphous Carbon-Boron Nitride Nanotube Hybrids

    Science.gov (United States)

    Kim, Jae Woo (Inventor); Siochi, Emilie J. (Inventor); Wise, Kristopher E. (Inventor); Lin, Yi (Inventor); Connell, John (Inventor)

    2016-01-01

    A method for joining or repairing boron nitride nanotubes (BNNTs). In joining BNNTs, the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures. In repairing BNNTs, the damaged site of the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures at the damage site.

  9. A Magnetic Sensor with Amorphous Wire

    Directory of Open Access Journals (Sweden)

    Dongfeng He

    2014-06-01

    Full Text Available Using a FeCoSiB amorphous wire and a coil wrapped around it, we have developed a sensitive magnetic sensor. When a 5 mm long amorphous wire with the diameter of 0.1 mm was used, the magnetic field noise spectrum of the sensor was about 30 pT/ÖHz above 30 Hz. To show the sensitivity and the spatial resolution, the magnetic field of a thousand Japanese yen was scanned with the magnetic sensor.

  10. DEFECTS IN AMORPHOUS CHALCOGENIDES AND SILICON

    OpenAIRE

    Adler, D.

    1981-01-01

    Our comprehension of the physical properties of amorphous semiconductors has improved considerably over the past few years, but many puzzles remain. From our present perspective, the major features of chalcogenide glasses appear to be well understood, and some of the fine points which have arisen recently have been explained within the same general model. On the other hand, there are a grear number of unresolved mysteries with regard to amorphous silicon-based alloys. In this paper, the valen...

  11. Climatic factors and bipolar affective disorder

    DEFF Research Database (Denmark)

    Christensen, Ellen Margrethe; Larsen, Jens Knud; Gjerris, Annette;

    2008-01-01

    . A group of patients with at least three previous hospitalizations for bipolar disorder was examined every 3 months for up to 3 years. At each examination an evaluation of the affective phase was made according to the Hamilton Depression Scale (HAM-D(17)), and the Bech-Rafaelsen Mania Rating Scale (MAS...... significant correlation between mean HAM-D(17) scores and change in mean and maximum temperature, and non-statistical significant correlations between mean MAS scores and rainfall plus atmospheric pressure, and non-statistical significant correlations between mean HAM-D(17) scores and hours of sunshine...

  12. A new bipolar Qtrim power supply system

    Energy Technology Data Exchange (ETDEWEB)

    Mi, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Bruno, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Drozd, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Nolan, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Orsatti, F. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Heppener, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Di Lieto, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Schultheiss, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Samms, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Zapasek, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Sandberg, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2015-05-03

    This year marks the 15th run of RHIC (Relativistic Heavy Ion Collider) operations. The reliability of superconducting magnet power supplies is one of the essential factors in the entire accelerator complex. Besides maintaining existing power supplies and their associated equipment, newly designed systems are also required based on the physicist’s latest requirements. A bipolar power supply was required for this year’s main quadruple trim power supply. This paper will explain the design, prototype, testing, installation and operation of this recently installed power supply system.

  13. Síntesis de sumadores bipolares

    OpenAIRE

    Mellado Rodríguez, E.; Alonso Rentería, Esther; Tarela Pereiro, José Manuel

    1982-01-01

    La clase de códigos denominada bipolar binaria incluye un amplio conjunto de códigos binarios con ciertas propiedades comunes. Este hecho, así como la circunstancia de que ciertos conjuntos de operadores funcionalmente completos que incluyen al EXOR facilitan la síntesis de funciones, se aplica a la obtención de sumadores generalizados tanto en el sentido de que aceptan más de dos entradas simultáneas como en el sentido de que éstas pudieran pertenecer a códigos diferentes. The class of co...

  14. Animal models of recurrent or bipolar depression.

    Science.gov (United States)

    Kato, T; Kasahara, T; Kubota-Sakashita, M; Kato, T M; Nakajima, K

    2016-05-01

    Animal models of mental disorders should ideally have construct, face, and predictive validity, but current animal models do not always satisfy these validity criteria. Additionally, animal models of depression rely mainly on stress-induced behavioral changes. These stress-induced models have limited validity, because stress is not a risk factor specific to depression, and the models do not recapitulate the recurrent and spontaneous nature of depressive episodes. Although animal models exhibiting recurrent depressive episodes or bipolar depression have not yet been established, several researchers are trying to generate such animals by modeling clinical risk factors as well as by manipulating a specific neural circuit using emerging techniques. PMID:26265551

  15. Dose Rate Effects in Linear Bipolar Transistors

    Science.gov (United States)

    Johnston, Allan; Swimm, Randall; Harris, R. D.; Thorbourn, Dennis

    2011-01-01

    Dose rate effects are examined in linear bipolar transistors at high and low dose rates. At high dose rates, approximately 50% of the damage anneals at room temperature, even though these devices exhibit enhanced damage at low dose rate. The unexpected recovery of a significant fraction of the damage after tests at high dose rate requires changes in existing test standards. Tests at low temperature with a one-second radiation pulse width show that damage continues to increase for more than 3000 seconds afterward, consistent with predictions of the CTRW model for oxides with a thickness of 700 nm.

  16. Neurocognitive features in subgroups of bipolar disorder

    OpenAIRE

    Aminoff, Sofie Ragnhild; Hellvin, Tone; Lagerberg, Trine Vik; Berg, Akiah Ottesen; Andreassen, Ole A; Melle, Ingrid

    2013-01-01

    Objective To examine which subgroups of DSM-IV bipolar disorder (BD) [BD type I (BD-I) or BD type II (BD-II), and subgroups based on history of psychosis, presenting polarity, and age at onset] differentiate best regarding neurocognitive measures. Methods A total of 199 patients with BD were characterized by clinical and neurocognitive features. The distribution of subgroups in this sample was: BD-I, 64% and BD-II, 36%; 60% had a history of psychosis; 57% had depression as the presenting pola...

  17. High-field electrical transport in amorphous phase-change materials

    Science.gov (United States)

    Kaes, Matthias; Le Gallo, Manuel; Sebastian, Abu; Salinga, Martin; Krebs, Daniel

    2015-10-01

    Electrical transport in chalcogenide-based phase change materials is an active area of research owing to the prominent role played by these materials in the field of information technology. Here, we present transport measurements (IV curves) obtained on line-cells of as-deposited amorphous phase change materials (Ge2Sb2Te5, GeTe, Ag4In3Sb66Te27) over a wide voltage and temperature range (300 K to 160 K). The well defined geometry of our devices enables a description of the transport behavior in terms of conductivity vs. electric field. At higher temperatures (300 K ≥ T ≥ 220 K) and low to intermediate fields (F behavior quantitatively.

  18. Photonic bandgap amorphous chalcogenide thin films with multilayered structure grown by pulsed laser deposition method

    Science.gov (United States)

    Zhang, Shao-qian; Němec, Petre; Nazabal, Virginie; Jin, Yu-qi

    2016-05-01

    Amorphous chalcogenide thin films were fabricated by the pulsed laser deposition technique. Thereafter, the stacks of multilayered thin films for reflectors and microcavity were designed for telecommunication wavelength. The prepared multilayered thin films for reflectors show good compatibility. The microcavity structure consists of Ge25Ga5Sb10S65 (doped with Er3+) spacer layer surrounded by two 5-layer As40Se60/Ge25Sb5S70 reflectors. Scanning/transmission electron microscopy results show good periodicity, great adherence and smooth interfaces between the alternating dielectric layers, which confirms a suitable compatibility between different materials. The results demonstrate that the chalcogenides can be used for preparing vertical Bragg reflectors and microcavity with high quality.

  19. Isospin structure in 68Ge

    Institute of Scientific and Technical Information of China (English)

    BAI Hong-Bo; DONG Hong-Fei; ZHANG Jin-Fu; LU Li-Jun; CAO Wan-Cang; LI Xiao-Wei; WANg Yin

    2009-01-01

    The interacting boson model-3(IBM-3) has been used to study the low-energy level structure and electromagnetic transitions of 68Ge nucleus. The main components of the wave function for some states are also analyzed respectively. The theoretical calculations are in agreement with experimental data, and the 68Ge is in transition from U(5) to SU(3).

  20. Electrical and structural properties of group-4 transition-metal nitride (TiN, ZrN, and HfN) contacts on Ge

    International Nuclear Information System (INIS)

    Electrical and structural properties were investigated for group-4 transition-metal nitride contacts on Ge (TiN/Ge, ZrN/Ge, and HfN/Ge), which were prepared by direct sputter depositions using nitride targets. These contacts could alleviate the intrinsic Fermi-level pinning (FLP) position toward the conduction band edge. It was revealed that this phenomenon is induced by an amorphous interlayer (a-IL) containing nitrogen atoms at the nitride/Ge interfaces. The strength of FLP alleviation positively depended on the thickness of a-IL. TiN/Ge and ZrN/Ge contacts with ∼2 nm-thick a-ILs showed strong FLP alleviations with hole barrier heights (ΦBP) in the range of 0.52–56 eV, and a HfN/Ge contact with an ∼1 nm-thick a-IL showed a weaker one with a ΦBP of 0.39 eV. However, TaN/Ge contact without a-IL did not show such FLP alleviation. Based on the results of depth distributions for respective elements, we discussed the formation kinetics of a-ILs at TiN/Ge and ZrN/Ge interfaces. Finally, we proposed an interfacial dipole model to explain the FLP alleviation

  1. Electrical and structural properties of group-4 transition-metal nitride (TiN, ZrN, and HfN) contacts on Ge

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Keisuke; Nakashima, Hiroshi, E-mail: nakasima@astec.kyushu-u.ac.jp [Art, Science and Technology Center for Cooperative Research, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Noguchi, Ryutaro; Wang, Dong [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Mitsuhara, Masatoshi; Nishida, Minoru [Department of Engineering Sciences for Electronics and Materials, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Hara, Toru [National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2015-09-21

    Electrical and structural properties were investigated for group-4 transition-metal nitride contacts on Ge (TiN/Ge, ZrN/Ge, and HfN/Ge), which were prepared by direct sputter depositions using nitride targets. These contacts could alleviate the intrinsic Fermi-level pinning (FLP) position toward the conduction band edge. It was revealed that this phenomenon is induced by an amorphous interlayer (a-IL) containing nitrogen atoms at the nitride/Ge interfaces. The strength of FLP alleviation positively depended on the thickness of a-IL. TiN/Ge and ZrN/Ge contacts with ∼2 nm-thick a-ILs showed strong FLP alleviations with hole barrier heights (Φ{sub BP}) in the range of 0.52–56 eV, and a HfN/Ge contact with an ∼1 nm-thick a-IL showed a weaker one with a Φ{sub BP} of 0.39 eV. However, TaN/Ge contact without a-IL did not show such FLP alleviation. Based on the results of depth distributions for respective elements, we discussed the formation kinetics of a-ILs at TiN/Ge and ZrN/Ge interfaces. Finally, we proposed an interfacial dipole model to explain the FLP alleviation.

  2. Gender and Depressive Symptoms in 711 Patients With Bipolar Disorder Evaluated Prospectively in the Stanley Foundation Bipolar Treatment Outcome Network

    NARCIS (Netherlands)

    Altshuler, Lori L.; Kupka, Ralph W.; Hellemann, Gerhard; Frye, Mark A.; Sugar, Catherine A.; McElroy, Susan L.; Nolen, Willem A.; Grunze, Heinz; Leverich, Gabriele S.; Keck, Paul E.; Zermeno, Melanie

    2010-01-01

    Objective: The authors assessed gender differences in the proportion of clinical visits spent depressed, manic, or euthymic in patients with bipolar disorder. Method: Data were analyzed from 711 patients with bipolar I or II disorder who were followed prospectively over 7 years (13,191 visits). The

  3. Ge-Au eutectic bonding of Ge {100} single crystals

    Science.gov (United States)

    Knowlton, W. B.; Itoh, K. M.; Beeman, J. W.; Emes, J. H.; Loretto, D.; Haller, E. E.

    1993-11-01

    We present preliminary results on the eutectic bonding between two {100} Ge single crystal surfaces using thin films of Au ranging from 900Å/surface to 300Å/surface and Pd (10% the thickness of Au). Following bonding, plan view optical microscopy (OM) of the cleaved interface of samples with Au thicknesses ≤ 500Å/surface show a eutectic morphology more conducive to phonon transmission through the bond interface. High resolution transmission electron microscopy (HRTEM) cross sectional interface studies of a 300Å/surface Au sample show epitaxial growth of Ge. In sections of the bond, lattice continuity of the Ge is apparent through the interface. TEM studies also reveal heteroepitaxial growth of Au with a Au-Ge lattice mismatch of less than 2%. Eutectic bonds with 200Å/surface Au have been attained with characterization pending. An optical polishing technique for Ge has been optimized to insure intimate contact between the Ge surfaces prior to bonding. Interferometry analysis of the optically polished Ge surface shows that surface height fluctuations lie within ±150Å across an interval of 1mm. Characterization of phonon transmission through the interface is discussed with respect to low temperature detection of ballistic phonons.

  4. Device Physics Analysis of Parasitic Conduction Band Barrier Formation in SiGe HBTs

    Science.gov (United States)

    Roenker, K. P.; Alterovitz, S. A.

    2000-01-01

    This paper presents a physics-based model describing the current-induced formation of a parasitic barrier in the conduction band at the base collector heterojunction in npn SiGe heterojunction bipolar transistors (HBTs). Due to the valence band discontinuity DELTA E(sub v), hole injection into the collector at the onset of base pushout is impeded, which gives rise to formation of a barrier to electron transport which degrades the device's high frequency performance. In this paper, we present results from an analytical model for the height of the barrier calculated from the device's structure as a function of the collector junction bias and collector current density.

  5. De-embedding and Modelling of pnp SiGe HBTs

    DEFF Research Database (Denmark)

    Hadziabdic, Dzenan; Jiang, Chenhui; Johansen, Tom Keinicke;

    2007-01-01

    In this work we present a direct parameter extraction procedure for SiGe pnp heterojunction bipolar transistor (HBT) large-signal and small-signal models. Test structure parasitics are removed from the measured small-signal parameters using an open-short de-embedding technique, improved to account...... for the distributed nature of the interconnect lines. Good agreement is achieved between the small-signal model of the HBT and the measurements. Parameters for the large-signal VBIC model are extracted based on multi-bias small-signal model extraction, leading to consistency between measured and...... modeled fBTB....

  6. Technology computer aided design for Si, SiGe and GaAs integrated circuits

    CERN Document Server

    Armstrong, GA

    2007-01-01

    The first book to deal with a broad spectrum of process and device design, and modelling issues related to semiconductor devices, bridging the gap between device modelling and process design using TCAD. Examples for types of Si-, SiGe-, GaAs- and InP-based heterostructure MOS and bipolar transistors are compared with experimental data from state-of-the-art devices. With various aspects of silicon heterostructures, this book presents a comprehensive perspective of emerging fields and covers topics ranging from materials to fabrication, devices, modelling and applications. Aimed at research-and-

  7. Rumination in bipolar disorder: a systematic review

    Directory of Open Access Journals (Sweden)

    Érico de M. Silveira Jr.

    2015-09-01

    Full Text Available Objective:To conduct a systematic review of the literature about the symptom of rumination in bipolar disorder (BD.Methods:We searched the MEDLINE (PubMed, ISI Web of Knowledge, PsycINFO, and SciELO databases using the descriptors “rumination” and “bipolar disorder” and no time limits. This strategy yielded 105 references, of which 74 were selected. Inclusion criteria were studies involving patients with BD and the use of at least one validated scale for the assessment of rumination. Review articles were excluded. Seventeen articles were ultimately analyzed and included in the review.Results:Rumination is present in all BD phases, is a stable interepisodic symptom, is associated with symptoms of depression, anxiety, and hypomania, and may occur in response to both positive and negative affect. There is no research on rumination and neurobiological findings in patients with BD.Conclusions:Rumination seems to be independent of mood state, but shows close relationship with it. It is possible that rumination has a negative impact on cognitive and executive functions, particularly inhibitory control. Finally, rumination is an important symptom in both phases of BD, and, therefore, may be a useful target for further exploration as a dimensional domain and a transdiagnostic phenomenon in Research Domain Criteria (RDoC projects.

  8. Loopy: The Political Ontology of Bipolar Disorder

    Directory of Open Access Journals (Sweden)

    RACHEL JANE LIEBERT

    2013-01-01

    Full Text Available This essay is at once a critical analysis, an experiment in form, and – with some irony – a cautionary tale. Triggered by the inclusion of prodromal diagnoses in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, and the recent call by the United States’ (U.S. Obama administration for increased mental health screening, I argue that shifts toward identifying and intervening on one’s potential madness, or risk, circulate with/in the contemporary U.S. climate of intensified discipline and terror, and use Bipolar Disorder as a site to critically explore how and with what implications this circulation occurs. Specifically, I weave Massumi’s ‘political ontology of threat’ with the narrative of a woman diagnosed with Bipolar Disorder in order to trace the pre-emptive politics and affective logic of a risk-based approach to madness. I contend that the diagnosing and drugging of potential is a self-perpetuating loop that is personally and politically harmful, and consider alternatives to this burgeoning practice.

  9. Polyphosphonium-based ion bipolar junction transistors.

    Science.gov (United States)

    Gabrielsson, Erik O; Tybrandt, Klas; Berggren, Magnus

    2014-11-01

    Advancements in the field of electronics during the past few decades have inspired the use of transistors in a diversity of research fields, including biology and medicine. However, signals in living organisms are not only carried by electrons but also through fluxes of ions and biomolecules. Thus, in order to implement the transistor functionality to control biological signals, devices that can modulate currents of ions and biomolecules, i.e., ionic transistors and diodes, are needed. One successful approach for modulation of ionic currents is to use oppositely charged ion-selective membranes to form so called ion bipolar junction transistors (IBJTs). Unfortunately, overall IBJT device performance has been hindered due to the typical low mobility of ions, large geometries of the ion bipolar junction materials, and the possibility of electric field enhanced (EFE) water dissociation in the junction. Here, we introduce a novel polyphosphonium-based anion-selective material into npn-type IBJTs. The new material does not show EFE water dissociation and therefore allows for a reduction of junction length down to 2 μm, which significantly improves the switching performance of the ion transistor to 2 s. The presented improvement in speed as well the simplified design will be useful for future development of advanced iontronic circuits employing IBJTs, for example, addressable drug-delivery devices. PMID:25553192

  10. The structural neuroimaging of bipolar disorder.

    Science.gov (United States)

    Emsell, Louise; McDonald, Colm

    2009-01-01

    There is an increasing body of literature fuelled by advances in high-resolution structural MRI acquisition and image processing techniques which implicates subtle neuroanatomical abnormalities in the aetiopathogenesis of bipolar disorder. This account reviews the main findings from structural neuroimaging research into regional brain abnormalities, the impact of genetic liability and mood stabilizing medication on brain structure in bipolar disorder, and the overlapping structural deviations found in the allied disorders of schizophrenia and depression. The manifold challenges extant within neuroimaging research are highlighted with accompanying recommendations for future studies. The most consistent findings include preservation of total cerebral volume with regional grey and white matter structural changes in prefrontal, midline and anterior limbic networks, non-contingent ventriculomegaly and increased rates of white matter hyperintensities, with more pronounced deficits in juveniles suffering from the illness. There is increasing evidence that medication has observable effects on brain structure, whereby lithium status is associated with volumetric increase in the medial temporal lobe and anterior cingulate gyrus. However, research continues to be confounded by the use of highly heterogeneous methodology and clinical populations, in studies employing small scale, low-powered, cross-sectional designs. Future work should investigate larger, clinically homogenous groups of patients and unaffected relatives, combining both categorical and dimensional approaches to illness classification in cross-sectional and longitudinal designs in order to elucidate trait versus state mechanisms, genetic effects and medication/illness progression effects over time. PMID:20374145

  11. A linkage study of bipolar disorder

    Energy Technology Data Exchange (ETDEWEB)

    Kelsoe, J.R. [Univ. of California, San Diego (United States); Sadovnick, A.D.; Remick, R.A. [Univ. of British Columbia, Vancouver (Canada)] [and others

    1994-09-01

    We are currently surveying the genome with polymorphic DNA markers in search of loci linked to bipolar disorder (manic-depressive illness) in three populations: 20 families (175 subjects) from the general North American population from San Diego (UCSD) and Vancouver (UBC); 3 Icelandic families (55 subjects); and an Old Order Amish pedigree 110 (118 subjects). Over 50 markers on chromosomes 1, 2, 5, 11, 17, 18, 20 and 21 have been examined. All markers have been tested in the Amish and Icelandic families, and a portion of them in the UCSD/UBC families, which we have only recently begun genotyping. The following candidate genes have been examined: {beta}-TSH, dopamine transporter (HDAT), {beta}2 adrenergic receptor (ADRB2), glucocorticoid type II receptor (GRL), D2 dopamine receptor, serotonin transporter (HSERT), and G{alpha}s G protein subunit (GNAS1). Linkage analysis was conducted using an autosomal dominant model with age-dependent reduced penetrance. Subjects with bipolar, schizoaffective, or recurrent major depressive disorders were considered affected. No significant evidence for linkage was obtained. Mildly positive lods ranging between 1.1 and 1.6 were obtained for three loci: D11S29, HDAT, and GRL.

  12. Transtorno bipolar do humor e gênero Bipolar affective disorder and gender

    Directory of Open Access Journals (Sweden)

    Rodrigo da Silva Dias

    2006-01-01

    Full Text Available Embora o transtorno bipolar (TB ocorra quase igualmente em ambos os sexos, a fenomenologia e o curso da doença diferem no homem e na mulher. No entanto, há evidências de que mulheres bipolares, mais que os homens, apresentariam início mais tardio (em especial na quinta década de vida, ciclagem rápida, mais episódios depressivos, mais mania disfórica que eufórica, estados mistos e evolução do tipo bipolar II, ainda que os achados nem sempre sejam consistentes. Embora o risco de comorbidades no TB inclua, para ambos os gêneros, abuso de álcool e drogas, homens bipolares teriam maior probabilidade de ser alcoolistas, não procurar tratamento e de se suicidar. Hipóteses sugeridas para explicar tais diferenças variam daquelas centradas em aspectos culturais ou psicológicos para as que focalizam os sistemas hormonais, como os esteróides gonadais ou o eixo tireoidiano, e até mesmo a anatomia cerebral. A influência do ciclo reprodutivo (ciclo menstrual, gravidez e menopausa sobre as opções terapêuticas no tratamento do TB é apresentada na última parte desta revisão.Although the bipolar disorder (BD occurs almost with the same frequency in both genders, the phenomenology and the outcome of the illness differ between them. Nevertheless, there is evidence that women with BD show, more than men, delayed beginning, especially in their fifth decade, more rapid cycling outcome, more depressive episodes, more dysphoric mania, more mixed states and more BD type II. Even so, the findings are not always consistent. Although the risk of comorbidities in BD includes, for both the sorts, excessive alcoholic consumption and drugs, bipolar men would have greater probability of being alcohol dependent, of not seeking treatment and of committing suicide. Suggested hypotheses to explain such differences vary from those centered in cultural or psychological aspects to those that focus on the steroids hormones, and other hormones such as cortisol

  13. Meta-Analysis of Amygdala Volumes in Children and Adolescents with Bipolar Disorder

    Science.gov (United States)

    Pfeifer, Jonathan C.; Welge, Jeffrey; Strakowski. Stephen M.; Adler, Caleb M.; Delbello, Melissa P.

    2008-01-01

    The size of amygdala of bipolar youths and adults is investigated using neuroimaging studies. Findings showed that smaller volumes of amygdala were observed in youths with bipolar youths compared with children and adolescents without bipolar disorder. The structural amygdala abnormalities in bipolar youths are examined further.

  14. Microstructural analyses of amorphic diamond, i-C, and amorphous carbon

    DEFF Research Database (Denmark)

    Collins, C. B.; Davanloo, F.; Jander, D.R.;

    1992-01-01

    comparative examinations of the microstructures of samples of amorphic diamond, i-C, and amorphous carbon. Four distinct morphologies were found that correlated closely with the energy densities used in preparing the different materials. Journal of Applied Physics is copyrighted by The American Institute of...... Physics....

  15. Electrons and phonons in amorphous semiconductors

    Science.gov (United States)

    Prasai, Kiran; Biswas, Parthapratim; Drabold, D. A.

    2016-07-01

    The coupling between lattice vibrations and electrons is one of the central concepts of condensed matter physics. The subject has been deeply studied for crystalline materials, but far less so for amorphous and glassy materials, which are among the most important for applications. In this paper, we explore the electron-lattice coupling using current tools of a first-principles computer simulation. We choose three materials to illustrate the phenomena: amorphous silicon (a-Si), amorphous selenium (a-Se) and amorphous gallium nitride (a-GaN). In each case, we show that there is a strong correlation between the localization of electron states and the magnitude of thermally induced fluctuations in energy eigenvalues obtained from the density-functional theory (i.e. Kohn–Sham eigenvalues). We provide a heuristic theory to explain these observations. The case of a-GaN, a topologically disordered partly ionic insulator, is distinctive compared to the covalent amorphous examples. Next, we explore the consequences of changing the charge state of a system as a proxy for tracking photo-induced structural changes in the materials. Where transport is concerned, we lend insight into the Meyer–Neldel compensation rule and discuss a thermally averaged Kubo–Greenwood formula as a means to estimate electrical conductivity and especially its temperature dependence. We close by showing how the optical gap of an amorphous semiconductor can be computationally engineered with the judicious use of Hellmann–Feynman forces (associated with a few defect states) using molecular dynamics simulations. These forces can be used to close or open an optical gap, and identify a structure with a prescribed gap. We use the approach with plane-wave density functional methods to identify a low-energy amorphous phase of silicon including several coordination defects, yet with a gap close to that of good quality a-Si models.

  16. Electrons and phonons in amorphous semiconductors

    Science.gov (United States)

    Prasai, Kiran; Biswas, Parthapratim; Drabold, D. A.

    2016-07-01

    The coupling between lattice vibrations and electrons is one of the central concepts of condensed matter physics. The subject has been deeply studied for crystalline materials, but far less so for amorphous and glassy materials, which are among the most important for applications. In this paper, we explore the electron-lattice coupling using current tools of a first-principles computer simulation. We choose three materials to illustrate the phenomena: amorphous silicon (a-Si), amorphous selenium (a-Se) and amorphous gallium nitride (a-GaN). In each case, we show that there is a strong correlation between the localization of electron states and the magnitude of thermally induced fluctuations in energy eigenvalues obtained from the density-functional theory (i.e. Kohn-Sham eigenvalues). We provide a heuristic theory to explain these observations. The case of a-GaN, a topologically disordered partly ionic insulator, is distinctive compared to the covalent amorphous examples. Next, we explore the consequences of changing the charge state of a system as a proxy for tracking photo-induced structural changes in the materials. Where transport is concerned, we lend insight into the Meyer-Neldel compensation rule and discuss a thermally averaged Kubo-Greenwood formula as a means to estimate electrical conductivity and especially its temperature dependence. We close by showing how the optical gap of an amorphous semiconductor can be computationally engineered with the judicious use of Hellmann-Feynman forces (associated with a few defect states) using molecular dynamics simulations. These forces can be used to close or open an optical gap, and identify a structure with a prescribed gap. We use the approach with plane-wave density functional methods to identify a low-energy amorphous phase of silicon including several coordination defects, yet with a gap close to that of good quality a-Si models.

  17. Growth of Ge Layer on Relaxed Ge-Rich SiGe by Ultrahigh Vacuum Chemical Vapor Deposition

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The paper describes the growth of a germanium (Ge) film on a thin relaxed Ge-rich SiGe buffer.The thin Ge-rich SiGe buffer layer was achieved through a combination of ultrahigh vacuum chemical vapor deposition (UHVCVD) SiGe epitaxial growth and SiGe oxidation. A lower Ge content strained SiGe layer was first grown on the Si (001) substrate and then the Ge mole fraction was increased by oxidation. After removal of the surface oxide, a higher Ge content SiGe layer was grown and oxidized again. The Ge mole fraction was increased to 0.8 in the 50 nm thick SiGe layer. Finally a 150 nm thick pure Ge film was grown on the SiGe buffer layer using the UHVCVD system. This technique produces a much thinner buffer than the conventional compositionally graded relaxed SiGe method with the same order of magnitude threading dislocation density.

  18. Atypical self-activation of Ga dopant for Ge nanowire devices.

    Science.gov (United States)

    Zeiner, Clemens; Lugstein, Alois; Burchhart, Thomas; Pongratz, Peter; Connell, Justin G; Lauhon, Lincoln J; Bertagnolli, Emmerich

    2011-08-10

    In this Letter we report the atypical self-activation of gallium (Ga) implanted by focused ion beam (FIB) into germanium nanowires (Ge-NWs). By FIB implantation of 30 keV Ga(+) ions at room temperature, the Ge-NW conductivity increases up to 3 orders of magnitude with increasing ion fluence. Cu(3)Ge heterostructures were formed by diffusion to ensure well-defined contacts to the NW and enable two point I/V measurements. Additional four point measurements prove that the conductivity enhancement emerges from the modification of the wires themselves and not from contact property modifications. The Ga distribution in the implanted Ge-NWs was measured using atom probe tomography. For high ion fluences, and beginning amorphization of the NWs, the conductivity decreases exponentially. Temperature dependent conductivity measurements show strong evidence for an in situ doping of the Ge-NWs without any further annealing. Finally the feasibility of improving the device performance of top-gated Ge-NW MOSFETs by FIB implantation was shown. PMID:21744779

  19. Ferromagnetism in Mn-Implanted Epitaxially Grown Ge on Si(100)

    Energy Technology Data Exchange (ETDEWEB)

    Guchhait, S.; Jamil, M.; Ohldag, H.; Mehta, A.; Arenholz, E.; Lian, G.; Li Fatou, A.; Ferrer, D. A.; Markert, J. T.; Colombo, L.; Banerjee, S. K.

    2011-01-05

    We have studied ferromagnetism of Mn-implanted epitaxial Ge films on silicon. The Ge films were grown by ultrahigh vacuum chemical vapor deposition using a mixture of germane (GeH{sub 4}) and methylgermane (CH{sub 3}GeH{sub 3}) gases with a carbon concentration of less than 1 at. %, and observed surface rms roughness of 0.5 nm, as measured by atomic force microscopy. Manganese ions were implanted in epitaxial Ge films grown on Si (100) wafers to an effective concentration of 16, 12, 6, and 2 at. %. Superconducting quantum interference device measurements showed that only the three highest Mn concentration samples are ferromagnetic, while the fourth sample, with [Mn] = 2 at. %, is paramagnetic. X-ray absorption spectroscopy and x-ray magnetic circular dichroism measurements indicate that localized Mn moments are ferromagnetically coupled below the Curie temperature. Isothermal annealing of Mn-implanted Ge films with [Mn] = 16 at. % at 300 C for up to 1200 s decreases the magnetization but does not change the Curie temperature, suggesting that the amount of the magnetic phase slowly decreases with time at this anneal temperature. Furthermore, transmission electron microscopy and synchrotron grazing incidence x-ray diffraction experiments show that the Mn-implanted region is amorphous, and we believe that it is this phase that is responsible for the ferromagnetism. This is supported by our observation that high-temperature annealing leads to recrystallization and transformation of the material into a paramagnetic phase.

  20. Magnetism of Mn doped in a-Si and a-Ge

    Science.gov (United States)

    Cao, Juexian

    2009-03-01

    With experimental studies and density function theory calculations, we report on the properties of Mn-doped amorphous Si and Ge which are designed to understand the fundamentals of cooperative phenomena in highly correlated electronic and magnetic systems. We observed a striking difference in Mn local moment when doped in a-Si and a-Ge matrices, in great contrast to the previous speculation that these two should behave very similar as the semiconductor host for transition metals. While we observed a large local moment of Mn in a-Ge, Mn moment is quenched in a-Si. The large difference of local magnetic moment of Mn in a-Si and a-Ge can be understood by the local atomic environment at the magnetic dopant sites, that is, the bond length and the coordination. Statistical DFT calculations shows that the magnetic dopant Mn with less coordination and large bond length hold large magnetic moment. Otherwise, the magnetic moment would be killed. In a-Ge, dopant Mn favours less coordination and large bond while more coordination and small bond length in a-Si, which result in the enhancement/quenchement of local magnetic moment Mn in a-Si/ a-Ge.

  1. Iron-based amorphous alloys and methods of synthesizing iron-based amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Saw, Cheng Kiong; Bauer, William A.; Choi, Jor-Shan; Day, Dan; Farmer, Joseph C.

    2016-05-03

    A method according to one embodiment includes combining an amorphous iron-based alloy and at least one metal selected from a group consisting of molybdenum, chromium, tungsten, boron, gadolinium, nickel phosphorous, yttrium, and alloys thereof to form a mixture, wherein the at least one metal is present in the mixture from about 5 atomic percent (at %) to about 55 at %; and ball milling the mixture at least until an amorphous alloy of the iron-based alloy and the at least one metal is formed. Several amorphous iron-based metal alloys are also presented, including corrosion-resistant amorphous iron-based metal alloys and radiation-shielding amorphous iron-based metal alloys.

  2. Perturbed reward processing in pediatric bipolar disorder: an antisaccade study.

    Science.gov (United States)

    Mueller, Sven C; Ng, Pamela; Temple, Veronica; Hardin, Michael G; Pine, Daniel S; Leibenluft, Ellen; Ernst, Monique

    2010-12-01

    Pediatric bipolar disorder is a severe and impairing illness. Characterizing the impact of pediatric bipolar disorder on cognitive function might aid in understanding the phenomenology of the disorder. While previous studies of pediatric bipolar disorder have reported deficits in cognitive control and reward behavior, little is understood about how affective processes influence behavioral control. Relative to prior studies using manual-response paradigms, eye movement tasks provide a more precise assessment of reward sensitivity and cognitive and motor control. The current study compares 20 youths with bipolar disorder (mean age = 13.9 years ± 2.22) and 23 healthy subjects (mean age = 13.8 years ± 2.49) on a mixed pro-antisaccade task with monetary incentives. On both types of saccades, participants were presented with three types of incentives: those where subjects can win money, lose money, or neither win nor lose money. Impaired reward processing was found in youths with bipolar disorder relative to controls, particularly on antisaccades. This difference was reflected in lower error rates during incentive trials in the control but not in the bipolar disorder group. By comparison, no group differences were found on prosaccade trials. The results provide further evidence for deficits in cognitive and reward processing in bipolar disorder. PMID:20080923

  3. Impulsivity and risk taking in bipolar disorder and schizophrenia.

    Science.gov (United States)

    Reddy, L Felice; Lee, Junghee; Davis, Michael C; Altshuler, Lori; Glahn, David C; Miklowitz, David J; Green, Michael F

    2014-01-01

    Impulsive risk taking contributes to deleterious outcomes among clinical populations. Indeed, pathological impulsivity and risk taking are common in patients with serious mental illness, and have severe clinical repercussions including novelty seeking, response disinhibition, aggression, and substance abuse. Thus, the current study seeks to examine self-reported impulsivity (Barratt Impulsivity Scale) and performance-based behavioral risk taking (Balloon Analogue Risk Task) in bipolar disorder and schizophrenia. Participants included 68 individuals with bipolar disorder, 38 with schizophrenia, and 36 healthy controls. Self-reported impulsivity was elevated in the bipolar group compared with schizophrenia patients and healthy controls, who did not differ from each other. On the risk-taking task, schizophrenia patients were significantly more risk averse than the bipolar patients and controls. Aside from the diagnostic group differences, there was a significant effect of antipsychotic (AP) medication within the bipolar group: bipolar patients taking AP medications were more risk averse than those not taking AP medications. This difference in risk taking because of AP medications was not explained by history of psychosis. Similarly, the differences in risk taking between schizophrenia and bipolar disorder were not fully explained by AP effects. Implications for clinical practice and future research are discussed. PMID:23963117

  4. Broadening the diagnosis of bipolar disorder: benefits vs. risks

    Science.gov (United States)

    STRAKOWSKI, STEPHEN M.; FLECK, DAVID E.; MAJ, MARIO

    2011-01-01

    There is considerable debate over whether bipolar and related disorders that share common signs and symptoms, but are currently defined as distinct clinical entities in DSM-IV and ICD-10, may be better characterized as falling within a more broadly defined “bipolar spectrum”. With a spectrum view in mind, the possibility of broadening the diagnosis of bipolar disorder has been proposed. This paper discusses some of the rationale for an expanded diagnostic scheme from both clinical and research perspectives in light of potential drawbacks. The ultimate goal of broadening the diagnosis of bipolar disorder is to help identify a common etiopathogenesis for these conditions to better guide treatment. To help achieve this goal, bipolar researchers have increasingly expanded their patient populations to identify objective biological or endophenotypic markers that transcend phenomenological observation. Although this approach has and will likely continue to produce beneficial results, the upcoming DSM-IV and ICD-10 revisions will place increasing scrutiny on psychiatry’s diagnostic classification systems and pressure to re-evaluate our conceptions of bipolar disorder. However, until research findings can provide consistent and converging evidence as to the validity of a broader diagnostic conception, clinical expansion to a dimensional bipolar spectrum should be considered with caution. PMID:21991268

  5. Bipolar II postpartum depression: Detection, diagnosis, and treatment.

    Science.gov (United States)

    Sharma, Verinder; Burt, Vivien K; Ritchie, Hendrica L

    2009-11-01

    Research on postpartum mood disorders has focused primarily on major depressive disorder, bipolar I disorder, and puerperal psychosis and has largely ignored or neglected bipolar II disorder. Hypomanic symptoms are common after delivery but frequently unrecognized. DSM-IV does not consider early postpartum hypomania as a significant diagnostic feature. Although postpartum hypomania may not cause marked impairment in social or occupational functioning, it is often associated with subsequent, often disabling depression. Preliminary evidence suggests that bipolar II depression arising in the postpartum period is often misdiagnosed as unipolar major depressive disorder. The consequences of the misdiagnosis can be particularly serious because of delayed initiation of appropriate treatment and the inappropriate prescription of antidepressants. Moreover, no pharmacological or psychotherapeutic studies of bipolar postpartum depression are available to guide clinical decision making. Also lacking are screening instruments designed specifically for use before or after delivery in women with suspected bipolar depression. It is recommended that the treatment of postpartum bipolar depression follow the same guidelines as the treatment of nonpuerperal bipolar II depression, using medications that are compatible with lactation.

  6. Uniaxially stressed Ge:Ga and Ge:Be

    Energy Technology Data Exchange (ETDEWEB)

    Dubon, O.D. Jr.

    1992-12-01

    The application of a large uniaxial stress to p-type Ge single crystals changes the character of both the valence band and the energy levels associated with the acceptors. Changes include the splitting of the fourfold degeneracy of the valence band top and the reduction of the ionization energy of shallow acceptors. In order to study the effect of uniaxial stress on transport properties of photoexcited holes, a variable temperature photo-Hall effect system was built in which stressed Ge:Ga and Ge:Be could be characterized. Results indicate that stress increases the lifetime and Hall mobility of photoexcited holes. These observations may help further the understanding of fundamental physical processes that affect the performance of stressed Ge photoconductors including the capture of holes by shallow acceptors.

  7. Three-dimensional fabrication and characterisation of core-shell nano-columns using electron beam patterning of Ge-doped SiO2

    DEFF Research Database (Denmark)

    Gontard, Lionel C.; Jinschek, Joerg R.; Ou, Haiyan;

    2012-01-01

    A focused electron beam in a scanning transmission electron microscope (STEM) is used to create arrays of core-shell structures in a specimen of amorphous SiO2 doped with Ge. The same electron microscope is then used to measure the changes that occurred in the specimen in three dimensions using e...

  8. Strain relaxation during solid-phase epitaxial crystallisation of Ge{sub x}Si{sub 1-x} alloy layers with depth dependent G{sub e} compositions

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Wahchung; Elliman, R.G.; Kringhoj, P. [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences

    1993-12-31

    The solid-phase epitaxial crystallisation of depth dependent Ge{sub x}Si{sub lx} alloy layers produced by implanting Ge into Si substrates was studied. In-situ monitoring was done using time-resolved reflectivity (TRR) whilst post-anneal defect structures were characterised by Rutherford backscattering and channeling spectrometry (RBS-C) and transmission electron microscopy (TEM). Particular attention was directed at Ge concentrations above the critical concentration for the growth of fully strained layers. Strain relief is shown to be correlated with a sudden reduction in crystallisation velocity caused by roughening of the crystalline/amorphous interface. 11 refs., 1 tab., 2 figs.

  9. Amorphous Diamond MEMS and Sensors

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN, JOHN P.; FRIEDMANN, THOMAS A.; ASHBY, CAROL I.; DE BOER, MAARTEN P.; SCHUBERT, W. KENT; SHUL, RANDY J.; HOHLFELDER, ROBERT J.; LAVAN, D.A.

    2002-06-01

    This report describes a new microsystems technology for the creation of microsensors and microelectromechanical systems (MEMS) using stress-free amorphous diamond (aD) films. Stress-free aD is a new material that has mechanical properties close to that of crystalline diamond, and the material is particularly promising for the development of high sensitivity microsensors and rugged and reliable MEMS. Some of the unique properties of aD include the ability to easily tailor film stress from compressive to slightly tensile, hardness and stiffness 80-90% that of crystalline diamond, very high wear resistance, a hydrophobic surface, extreme chemical inertness, chemical compatibility with silicon, controllable electrical conductivity from insulating to conducting, and biocompatibility. A variety of MEMS structures were fabricated from this material and evaluated. These structures included electrostatically-actuated comb drives, micro-tensile test structures, singly- and doubly-clamped beams, and friction and wear test structures. It was found that surface micromachined MEMS could be fabricated in this material easily and that the hydrophobic surface of the film enabled the release of structures without the need for special drying procedures or the use of applied hydrophobic coatings. Measurements using these structures revealed that aD has a Young's modulus of {approx}650 GPa, a tensile fracture strength of 8 GPa, and a fracture toughness of 8 MPa{center_dot}m {sup 1/2}. These results suggest that this material may be suitable in applications where stiction or wear is an issue. Flexural plate wave (FPW) microsensors were also fabricated from aD. These devices use membranes of aD as thin as {approx}100 nm. The performance of the aD FPW sensors was evaluated for the detection of volatile organic compounds using ethyl cellulose as the sensor coating. For comparable membrane thicknesses, the aD sensors showed better performance than silicon nitride based sensors. Greater

  10. Intervenções psicossociais no transtorno bipolar Psychosocial interventions for bipolar disorder

    Directory of Open Access Journals (Sweden)

    Luis Pereira Justo

    2004-01-01

    Full Text Available Neste trabalho, os autores, através de revisão bibliográfica narrativa, situam as intervenções psicossociais dentro do panorama terapêutico para o transtorno bipolar e constatam que ainda são insuficientes os estudos primários feitos com metodologia adequada para a obtenção de informações científicas de boa qualidade. São sucintamente descritos os trabalhos mais relevantes.In this paper, the authors review the status of psychosocial interventions within the general treatment for bipolar disorder. They have verified the scantiness of studies performed with adequate methodology to obtain scientific information of good quality. The more relevant studies are briefly described.

  11. Differences between bipolar and unipolar depression on Rorschach testing

    Directory of Open Access Journals (Sweden)

    Kimura H

    2013-05-01

    Full Text Available Hiromi Kimura, Akemi Osaki, Rui Kawashima, Takeshi Inoue, Shin Nakagawa, Katsuji Suzuki, Satoshi Asakura, Teruaki Tanaka, Yuji Kitaichi, Takuya Masui, Nobuki Kitagawa, Yuki Kako, Tomohiro Abekawa, Ichiro Kusumi, Hiroyoshi Yamanaka, Kenzo Denda, Tsukasa KoyamaDepartment of Psychiatry, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, JapanBackground: The bipolar-unipolar distinction in patients with a major depressive episode is the most important issue related to the diagnosis and treatment of mood disorders, but remains unresolved. This study was undertaken to compare bipolar and unipolar depression on Rorschach testing using the Comprehensive System with reference to healthy Japanese controls.Methods: Patients with bipolar or unipolar depression who had undergone the Rorschach test for routine clinical purposes were followed up naturalistically for a long period. Based on diagnostic confirmation after long-term follow-up, scores on this test for patients with bipolar and unipolar depression were compared with those published elsewhere for healthy Japanese controls.Results: The bipolar depression group showed significantly higher scores or positive findings in five variables of the Rorschach test, ie, WSum6, DR2 > 0, (CF + C > FC + 2, PureC > 1, and Populars > 7, as assessed using the Comprehensive System, than did the unipolar depression group and healthy controls. These scores did not differ between the unipolar depression and control groups.Conclusion: The results of this study show thought disorder or cognitive slippage and marked laxness in modulating emotion in bipolar depression, indicating the psychopathological characteristics of bipolar disorder.Keywords: bipolar depression, bipolar disorder, Rorschach test, thought disorder, unipolar depression

  12. Evidence for genetic association of RORB with bipolar disorder

    Directory of Open Access Journals (Sweden)

    Mick Eric

    2009-11-01

    Full Text Available Abstract Background Bipolar disorder, particularly in children, is characterized by rapid cycling and switching, making circadian clock genes plausible molecular underpinnings for bipolar disorder. We previously reported work establishing mice lacking the clock gene D-box binding protein (DBP as a stress-reactive genetic animal model of bipolar disorder. Microarray studies revealed that expression of two closely related clock genes, RAR-related orphan receptors alpha (RORA and beta (RORB, was altered in these mice. These retinoid-related receptors are involved in a number of pathways including neurogenesis, stress response, and modulation of circadian rhythms. Here we report association studies between bipolar disorder and single-nucleotide polymorphisms (SNPs in RORA and RORB. Methods We genotyped 355 RORA and RORB SNPs in a pediatric cohort consisting of a family-based sample of 153 trios and an independent, non-overlapping case-control sample of 152 cases and 140 controls. Bipolar disorder in children and adolescents is characterized by increased stress reactivity and frequent episodes of shorter duration; thus our cohort provides a potentially enriched sample for identifying genes involved in cycling and switching. Results We report that four intronic RORB SNPs showed positive associations with the pediatric bipolar phenotype that survived Bonferroni correction for multiple comparisons in the case-control sample. Three RORB haplotype blocks implicating an additional 11 SNPs were also associated with the disease in the case-control sample. However, these significant associations were not replicated in the sample of trios. There was no evidence for association between pediatric bipolar disorder and any RORA SNPs or haplotype blocks after multiple-test correction. In addition, we found no strong evidence for association between the age-at-onset of bipolar disorder with any RORA or RORB SNPs. Conclusion Our findings suggest that clock genes in

  13. Understanding Thermal Conductivity in Amorphous Materials

    Science.gov (United States)

    Kommandur, Sampath; Yee, Shannon

    2014-03-01

    Current energy technologies such as thermoelectrics, photovoltaics, and LEDs make extensive use of amorphous materials and are limited by heat transfer. Device improvements necessitate a better understanding of the thermal conductivity in amorphous materials. While there are basic theories that capture the trends in thermal conductivity of a select set of amorphous materials, a general framework is needed to explain the fundamental transport of heat in all amorphous materials. One empirical theory that has been successful at describing the thermal conductivity in some materials is the k-min model, however, assumptions in that model limit its generalizability. Another theory defines the existence of propagons, diffusons, and locons, which constitute vibrational modes that carry heat. Our work first presents a summary of literature on the thermal conductivity in amorphous materials and then compares those theories to a breadth of experimental data. Based upon those results, a generic model is proposed that is widely applicable with the ultimate goal of this work being to describe the temperature dependent thermal conductivity of polymers. -/abstract- Sampath Kommandur and Shannon K. Yee 21.1.1: Thermoelectric Phenomena, Materials, Devices, and Applications (GER

  14. Crystallization of amorphous Zr-Be alloys

    Science.gov (United States)

    Golovkova, E. A.; Surkov, A. V.; Syrykh, G. F.

    2015-02-01

    The thermal stability and structure of binary amorphous Zr100 - x Be x alloys have been studied using differential scanning calorimetry and neutron diffraction over a wide concentration range (30 ≤ x ≤ 65). The amorphous alloys have been prepared by rapid quenching from melt. The studied amorphous system involves the composition range around the eutectic composition with boundary phases α-Zr and ZrBe2. It has been found that the crystallization of alloys with low beryllium contents ("hypoeutectic" alloys with x ≤ 40) proceeds in two stages. Neutron diffraction has demonstrated that, at the first stage, α-Zr crystallizes and the remaining amorphous phase is enriched to the eutectic composition; at the second stage, the alloy crystallizes in the α-Zr and ZrBe2 phases. At higher beryllium contents ("hypereutectic" alloys), one phase transition of the amorphous phase to a mixture of the α-Zr and ZrBe2 phases has been observed. The concentration dependences of the crystallization temperature and activation energy have been revealed.

  15. Amorphous silicon detectors in positron emission tomography

    International Nuclear Information System (INIS)

    The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters ε2τ's are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs

  16. Amorphous silicon detectors in positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Conti, M. (Istituto Nazionale di Fisica Nucleare, Pisa (Italy) Lawrence Berkeley Lab., CA (USA)); Perez-Mendez, V. (Lawrence Berkeley Lab., CA (USA))

    1989-12-01

    The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters {epsilon}{sup 2}{tau}'s are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs.

  17. Secondary growth mechanism of SiGe islands deposited on a mixed-phase microcrystalline Si by ion beam co-sputtering

    Science.gov (United States)

    Ke, S. Y.; Yang, J.; Qiu, F.; Wang, Z. Q.; Wang, C.; Yang, Y.

    2015-11-01

    We discuss the SiGe island co-sputtering deposition on a microcrystalline silicon (μc-Si) buffer layer and the secondary island growth based on this pre-SiGe island layer. The growth phenomenon of SiGe islands on crystalline silicon (c-Si) is also investigated for comparison. The pre-SiGe layer grown on μc-Si exhibits a mixed-phase structure, including SiGe islands and amorphous SiGe (a-SiGe) alloy, while the layer deposited on c-Si shows a single-phase island structure. The preferential growth and Ostwald ripening growth are shown to be the secondary growth mechanism of SiGe islands on μc-Si and c-Si, respectively. This difference may result from the effect of amorphous phase Si (AP-Si) in μc-Si on the island growth. In addition, the Si-Ge intermixing behavior of the secondary-grown islands on μc-Si is interpreted by constructing the model of lateral atomic migration, while this behavior on c-Si is ascribed to traditional uphill atomic diffusion. It is found that the aspect ratios of the preferential-grown super islands are higher than those of the Ostwald-ripening ones. The lower lateral growth rate of super islands due to the lower surface energy of AP-Si on the μc-Si buffer layer for the non-wetting of Ge at 700 °C and the stronger Si-Ge intermixing effect at 730 °C may be responsible for this aspect ratio difference.

  18. Secondary growth mechanism of SiGe islands deposited on a mixed-phase microcrystalline Si by ion beam co-sputtering.

    Science.gov (United States)

    Ke, S Y; Yang, J; Qiu, F; Wang, Z Q; Wang, C; Yang, Y

    2015-11-01

    We discuss the SiGe island co-sputtering deposition on a microcrystalline silicon (μc-Si) buffer layer and the secondary island growth based on this pre-SiGe island layer. The growth phenomenon of SiGe islands on crystalline silicon (c-Si) is also investigated for comparison. The pre-SiGe layer grown on μc-Si exhibits a mixed-phase structure, including SiGe islands and amorphous SiGe (a-SiGe) alloy, while the layer deposited on c-Si shows a single-phase island structure. The preferential growth and Ostwald ripening growth are shown to be the secondary growth mechanism of SiGe islands on μc-Si and c-Si, respectively. This difference may result from the effect of amorphous phase Si (AP-Si) in μc-Si on the island growth. In addition, the Si-Ge intermixing behavior of the secondary-grown islands on μc-Si is interpreted by constructing the model of lateral atomic migration, while this behavior on c-Si is ascribed to traditional uphill atomic diffusion. It is found that the aspect ratios of the preferential-grown super islands are higher than those of the Ostwald-ripening ones. The lower lateral growth rate of super islands due to the lower surface energy of AP-Si on the μc-Si buffer layer for the non-wetting of Ge at 700 °C and the stronger Si-Ge intermixing effect at 730 °C may be responsible for this aspect ratio difference.

  19. Neutron studies of amorphous solids

    International Nuclear Information System (INIS)

    The thesis begins with an introduction to glass and glass science, followed by a brief overview of the theory of neutron scattering. A background to neutron experiments is given and a more detailed description of the sources and instruments used. Subsequent chapters are then devoted to lead and zinc phosphate glasses, iron phosphate glasses, ultra low expansion glass, boron sulphide glass, bismuth containing glasses, pressure compacted glasses and cesium borate glasses. Lead and zinc phosphate glasses were found to have a coordination number of four for Pb or Zn and the lead and zinc were both incorporated into the network structure. In ultra low expansion glass the titania was found to be four fold coordinated. Vitreous boron sulphide gives results consistent with borsulphol superstructural units. Diffraction patterns for the bismuth borate glasses suggest an asymmetric B-O bond length distribution for the BO3 triangles and BO4 tetrahedra. The fraction of four fold coordinated boron atoms increases from 0.35 at 31 Mol.% to 0.55 at 67 Mol.%. The data are also consistent with the presence of superstructural units. The results for bismuth germanate glass have confirmed that the bismuth atoms are six-fold coordinated but with distorted octahedra. The GeO4 tetrahedra are relatively undistorted. In pressure compacted glasses the main mechanism is the compression of the network cages. In the case of the cesium borate glasses the B-O peak indicates the existence of both three and four coordinated boron. Superstructural units were found to be present even at high Cs2O contents. The above results have shown that superstructural units are found in many borate glasses. (author)

  20. Bipolar affective puerperal psychosis- genome-wide significant evidence for linkage to chromosome 16.

    OpenAIRE

    Corvin, Aiden; Gill, Michael

    2007-01-01

    OBJECTIVE: Vulnerability to the triggering of bipolar episodes by childbirth aggregates in families and may define a genetically relevant subtype of bipolar disorder. The authors conducted a search by systematic whole genome linkage scan for loci influencing vulnerability to bipolar affective puerperal psychosis. METHOD: The authors selected families with bipolar disorder from their previous bipolar disorder genome scan, in which there was at least one family member with a manic or psychotic ...