High-performance indium gallium phosphide/gallium arsenide heterojunction bipolar transistors

Science.gov (United States)

Ahmari, David Abbas

Heterojunction bipolar transistors (HBTs) have demonstrated the high-frequency characteristics as well as the high linearity, gain, and power efficiency necessary to make them attractive for a variety of applications. Specific applications for which HBTs are well suited include amplifiers, analog-to-digital converters, current sources, and optoelectronic integrated circuits. Currently, most commercially available HBT-based integrated circuits employ the AlGaAs/GaAs material system in applications such as a 4-GHz gain block used in wireless phones. As modern systems require higher-performance and lower-cost devices, HBTs utilizing the newer, InGaP/GaAs and InP/InGaAs material systems will begin to dominate the HBT market. To enable the widespread use of InGaP/GaAs HBTs, much research on the fabrication, performance, and characterization of these devices is required. This dissertation will discuss the design and implementation of high-performance InGaP/GaAs HBTs as well as study HBT device physics and characterization.

Direct Extraction of InP/GaAsSb/InP DHBT Equivalent-Circuit Elements From S-Parameters Measured at Cut-Off and Normal Bias Conditions

DEFF Research Database (Denmark)

Johansen, Tom Keinicke; Leblanc, Rémy; Poulain, Julien

2016-01-01

A unique direct parameter extraction method for the small-signal equivalent-circuit model of InP/GaAsSb/InP double heterojunction bipolar transistors (DHBTs) is presented. $S$-parameters measured at cut-off bias are used, at first, to extract the distribution factor $X_{0}$ for the base-collector......A unique direct parameter extraction method for the small-signal equivalent-circuit model of InP/GaAsSb/InP double heterojunction bipolar transistors (DHBTs) is presented. $S$-parameters measured at cut-off bias are used, at first, to extract the distribution factor $X_{0}$ for the base......-collector capacitance at zero collector current and the collector-to-emitter overlap capacitance $C_{ceo}$ present in InP DHBT devices. Low-frequency $S$-parameters measured at normal bias conditions then allows the extraction of the external access resistances $R_{bx}$, $R_{e}$, and $R_{cx}$ as well as the intrinsic...

Procedure to derive analytical models for microwave noise performances of Si/SiGe:C and InP/InGaAs heterojunction bipolar transistors

International Nuclear Information System (INIS)

Ramirez-Garcia, E; Enciso-Aguilar, M A; Aniel, F P; Zerounian, N

2013-01-01

We present a useful procedure to derive simplified expressions to model the minimum noise factor and the equivalent noise resistance of Si/SiGe:C and InP/InGaAs heterojunction bipolar transistors (HBTs). An acceptable agreement between models and measurements at operation frequencies up to 18 GHz and at several bias points is demonstrated. The development procedure includes all the significant microwave noise sources of the HBTs. These relations should be useful to model F min and R n for state-of-the-art IV-IV and III–V HBTs. The method is the first step to derive noise analyses formulas valid for operation frequencies near the unitary current gain frequency (f T ); however, to achieve this goal a necessary condition is to have access to HFN measurements up to this frequency regime. (paper)

The Aluminum-Free P-n-P InGaAsN Double Heterojunction Bipolar Transistors

Energy Technology Data Exchange (ETDEWEB)

CHANG,PING-CHIH; LI,N.Y.; BACA,ALBERT G.; MONIER,C.; LAROCHE,J.R.; HOU,H.Q.; REN,F.; PEARTON,S.J.

2000-08-01

The authors have demonstrated an aluminum-free P-n-P GaAs/InGaAsN/GaAs double heterojunction bipolar transistor (DHBT). The device has a low turn-on voltage (V{sub ON}) that is 0.27 V lower than in a comparable P-n-p AlGaAs/GaAs HBT. The device shows near-ideal D. C. characteristics with a current gain ({beta}) greater than 45. The high-speed performance of the device are comparable to a similar P-n-p AlGaAs/GaAs HBT, with f{sub T} and f{sub MAX} values of 12 GHz and 10 GHz, respectively. This device is very suitable for low-power complementary HBT circuit applications, while the aluminum-free emitter structure eliminates issues typically associated with AlGaAs.

Fluid phase passivation and polymer encapsulation of InP/InGaAs heterojunction bipolar transistors

International Nuclear Information System (INIS)

Oxland, R K; Rahman, F

2008-01-01

This paper reports on the development of effective passivation techniques for improving and stabilizing the characteristics of InP/InGaAs heterojunction bipolar transistors. Two different methods for carrying out sulfur-based surface passivations are compared. These include exposure to gaseous hydrogen sulfide and immersion treatment in an ammonium sulfide solution. The temporal behaviour of effects resulting from such passivation treatments is reported. It is shown that liquid phase passivation has a larger beneficial effect on device performance than gas phase passivation. This is explained in terms of the polarity of passivating species and the exposed semiconductor surface. Finally, device encapsulation in a novel chalcogenide polymer is shown to be effective in preserving the benefits of surface passivation treatments. The relevant properties of this encapsulation material are also discussed

Heterojunction bipolar assembly with CrxTi1-xO2 thin films and vertically aligned ZnO nanorods

International Nuclear Information System (INIS)

Das, Soumen; Kim, Sang-Hoon; Park, Yong-Kyu; Choi, Cheol-Min; Kim, Dae-Young; Hahn, Yoon-Bong

2010-01-01

Polycrystalline and homogeneous Cr x Ti 1-x O 2 thin films were deposited on silicon (Si) substrates and on indium doped tin oxide (ITO) coated glass substrates by spin coating technique. We report the p-type conductivity in Cr x Ti 1-x O 2 thin films (x = 0.005, 0.05, 0.1, 0.15, 0.2) and variable turn-on voltages (V O ) in heterojunction ZnO-nanorod/Cr x Ti 1-x O 2 /ITO bipolar device. Results showed that V O varies substantially from ∼0.8 V (x = 0.005) to ∼0.53 (x = 0.2) for the bipolar assembly. X-ray photoelectron spectroscopy (XPS) showed that chemical state of Ti is the +4 valence state and Cr remains in three different oxidation states of +3. XPS in the valence band region showed a shift in the binding energy towards the lower energy side with increasing Cr intake confirming more p-type conductivity in Cr x Ti 1-x O 2 thin films.

Fabrication and Characterization of N-Type Zinc Oxide/P-Type Boron Doped Diamond Heterojunction

Science.gov (United States)

Marton, Marián; Mikolášek, Miroslav; Bruncko, Jaroslav; Novotný, Ivan; Ižák, Tibor; Vojs, Marian; Kozak, Halyna; Varga, Marián; Artemenko, Anna; Kromka, Alexander

2015-09-01

Diamond and ZnO are very promising wide-bandgap materials for electronic, photovoltaic and sensor applications because of their excellent electrical, optical, physical and electrochemical properties and biocompatibility. In this contribution we show that the combination of these two materials opens up the potential for fabrication of bipolar heterojunctions. Semiconducting boron doped diamond (BDD) thin films were grown on Si and UV grade silica glass substrates by HFCVD method with various boron concentration in the gas mixture. Doped zinc oxide (ZnO:Al, ZnO:Ge) thin layers were deposited by diode sputtering and pulsed lased deposition as the second semiconducting layer on the diamond films. The amount of dopants within the films was varied to obtain optimal semiconducting properties to form a bipolar p-n junction. Finally, different ZnO/BDD heterostructures were prepared and analyzed. Raman spectroscopy, SEM, Hall constant and I-V measurements were used to investigate the quality, structural and electrical properties of deposited heterostructures, respectively. I-V measurements of ZnO/BDD diodes show a rectifying ratio of 55 at ±4 V. We found that only very low dopant concentrations for both semiconducting materials enabled us to fabricate a functional p-n junction. Obtained results are promising for fabrication of optically transparent ZnO/BDD bipolar heterojunction.

Cryogenic preamplification of a single-electron-transistor using a silicon-germanium heterojunction-bipolar-transistor

Energy Technology Data Exchange (ETDEWEB)

Curry, M. J. [Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Center for Quantum Information and Control, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Sandia National Laboratories, 1515 Eubank Blvd SE, Albuquerque, New Mexico 87123 (United States); England, T. D.; Bishop, N. C.; Ten-Eyck, G.; Wendt, J. R.; Pluym, T.; Lilly, M. P.; Carroll, M. S. [Sandia National Laboratories, 1515 Eubank Blvd SE, Albuquerque, New Mexico 87123 (United States); Carr, S. M. [Center for Quantum Information and Control, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Sandia National Laboratories, 1515 Eubank Blvd SE, Albuquerque, New Mexico 87123 (United States)

2015-05-18

We examine a silicon-germanium heterojunction bipolar transistor (HBT) for cryogenic pre-amplification of a single electron transistor (SET). The SET current modulates the base current of the HBT directly. The HBT-SET circuit is immersed in liquid helium, and its frequency response from low frequency to several MHz is measured. The current gain and the noise spectrum with the HBT result in a signal-to-noise-ratio (SNR) that is a factor of 10–100 larger than without the HBT at lower frequencies. The transition frequency defined by SNR = 1 has been extended by as much as a factor of 10 compared to without the HBT amplification. The power dissipated by the HBT cryogenic pre-amplifier is approximately 5 nW to 5 μW for the investigated range of operation. The circuit is also operated in a single electron charge read-out configuration in the time-domain as a proof-of-principle demonstration of the amplification approach for single spin read-out.

Tunneling-assisted transport of carriers through heterojunctions.

Energy Technology Data Exchange (ETDEWEB)

Wampler, William R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Myers, Samuel M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Modine, Normand A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-10-01

The formulation of carrier transport through heterojunctions by tunneling and thermionic emission is derived from first principles. The treatment of tunneling is discussed at three levels of approximation: numerical solution of the one-band envelope equation for an arbitrarily specified potential profile; the WKB approximation for an arbitrary potential; and, an analytic formulation assuming constant internal field. The effects of spatially varying carrier chemical potentials over tunneling distances are included. Illustrative computational results are presented. The described approach is used in exploratory physics models of irradiated heterojunction bipolar transistors within Sandia's QASPR program.

Improved External Base Resistance Extraction for Submicrometer InP/InGaAs DHBT Models

DEFF Research Database (Denmark)

Johansen, Tom Keinicke; Krozer, Viktor; Nodjiadjim, Virginie

2011-01-01

An improved direct parameter extraction method is proposed for III–V heterojunction bipolar transistor (HBT) external base resistance $R_{\\rm bx}$ extraction from forward active $S$-parameters. The method is formulated taking into account the current dependence of the intrinsic base–collector cap......An improved direct parameter extraction method is proposed for III–V heterojunction bipolar transistor (HBT) external base resistance $R_{\\rm bx}$ extraction from forward active $S$-parameters. The method is formulated taking into account the current dependence of the intrinsic base...... factor given as the ratio of the emitter to the collector area. The determination of the parameters $I_{p}$ and $X_{0}$ from experimental $S$-parameters is described. The method is applied to high-speed submicrometer InP/InGaAs DHBT devices and leads to small-signal equivalent circuit models, which...

Experimental Investigation of a Direct Methanol Fuel Cell with Hilbert Fractal Current Collectors

Directory of Open Access Journals (Sweden)

Jing-Yi Chang

2014-01-01

Full Text Available The Hilbert curve is a continuous type of fractal space-filling curve. This fractal curve visits every point in a square grid with a size of 2×2, 4×4, or any other power of two. This paper presents Hilbert fractal curve application to direct methanol fuel cell (DMFC current collectors. The current collectors are carved following first, second, and third order Hilbert fractal curves. These curves give the current collectors different free open ratios and opening perimeters. We conducted an experimental investigation into DMFC performance as a function of the free open ratio and opening perimeter on the bipolar plates. Nyquist plots of the bipolar plates are made and compared using electrochemical impedance spectroscopy (EIS experiments to understand the phenomena in depth. The results obtained in this paper could be a good reference for future current collector design.

Electrical properties of InP/InGaAs heterojunction bipolar transistors

International Nuclear Information System (INIS)

Ouacha, A.

1993-01-01

In recent years, there has been considerable interest in indium phosphide (InP) and In-based III-V compounds because of their applications in many electronic and photonic devices. The issues involved in processing high quality InP-based devices have been widely explored during the last decade. Realization of highly reliable, high speed, and long distance fiber-optics communication systems requires good quality of the material growth, characterization techniques and reproducible device processing concepts. All these three elements should be included in the manufacturing sequence in order to produce devices of high quality. Until recently, most of the InP related technologies and advances have been focused around optical fiber communications (1.3-1.55 μm) where Si and GaAs could not compete. The main obstacle to rapid growth of InP based technology in the 80s was the enormous investment and interest of large companies and commercial research organizations in GaAs technology. Supporting and financing InP related devices and material was at best minimal. As a consequence, there has been a much slower perhaps more realistic development curve for non-optical InP-based devices and technologies. InP technology has survived solely on the basic of its technical performance, despite the financial problems. In this thesis, we investigate the static behaviour of InP/InGaAs heterojunction bipolar transistors (HBTs) which have attracted a significant amount of attention. (20 refs., 5 figs., 3 tabs.)

DC modeling and characterization of AlGaAs/GaAs heterojunction bipolar transistors for high-temperature applications

International Nuclear Information System (INIS)

Dikmen, C.T.; Dogan, N.S.; Osman, M.A.

1994-01-01

There is currently a demand for active electronic devices operating reliably over wide range of temperatures. Potential applications for the high-temperature devices and integrated circuits are in the areas of jet engine and control instrumentation for nuclear power plants. Here, the large signal dc characteristics of AlGaAs/GaAs heterojunction bipolar transistors (HBT) at high temperatures (27--300 C) are reported. A high-temperature SPICE model is developed which includes the recombination-generation current components and avalanche multiplication which become extremely important at high temperatures. The effect of avalanche breakdown is also included to model the current due to thermal generation of electron/hole pairs causing breakdown at high temperatures. A parameter extraction program is developed used to extract the model parameters of HBT's at different temperatures. Fitting functions for the model parameters as a function of temperature are developed. These parameters are then used in the SPICE Ebers-Moll model for the dc characterization of the HBT at any temperature between (27--300 C)

Detailed balance theory of excitonic and bulk heterojunction solar cells

Science.gov (United States)

Kirchartz, Thomas; Mattheis, Julian; Rau, Uwe

2008-12-01

A generalized solar cell model for excitonic and classical bipolar solar cells describes the combined transport and interaction of electrons, holes, and excitons in accordance with the principle of detailed balance. Conventional inorganic solar cells, single-phase organic solar cells and bulk heterojunction solar cells, i.e., nanoscale mixtures of two organic materials, are special cases of this model. For high mobilities, the compatibility with the principle of detailed balance ensures that our model reproduces the Shockley-Queisser limit irrespective of how the energy transport is achieved. For less ideal devices distinct differences become visible between devices that are described by linear differential equations and those with nonlinear effects, such as a voltage-dependent collection in bipolar p-i-n -type devices. These differences in current-voltage characteristics are also decisive for the validity of the reciprocity theorem between photovoltaic quantum efficiency and electroluminescent emission. Finally, we discuss the effect of band offset at the heterointerface in a bulk heterojunction cell and the effect of the average distances between these heterointerfaces on the performance of a solar cell in order to show how our detailed balance model includes also these empirically important quantities.

A G-band terahertz monolithic integrated amplifier in 0.5-μm InP double heterojunction bipolar transistor technology

International Nuclear Information System (INIS)

Li Ou-Peng; Zhang Yong; Xu Rui-Min; Cheng Wei; Wang Yuan; Niu Bing; Lu Hai-Yan

2016-01-01

Design and characterization of a G-band (140–220 GHz) terahertz monolithic integrated circuit (TMIC) amplifier in eight-stage common-emitter topology are performed based on the 0.5-μm InGaAs/InP double heterojunction bipolar transistor (DHBT). An inverted microstrip line is implemented to avoid a parasitic mode between the ground plane and the InP substrate. The on-wafer measurement results show that peak gains are 20 dB at 140 GHz and more than 15-dB gain at 140–190 GHz respectively. The saturation output powers are −2.688 dBm at 210 GHz and −2.88 dBm at 220 GHz, respectively. It is the first report on an amplifier operating at the G-band based on 0.5-μm InP DHBT technology. Compared with the hybrid integrated circuit of vacuum electronic devices, the monolithic integrated circuit has the advantage of reliability and consistency. This TMIC demonstrates the feasibility of the 0.5-μm InGaAs/InP DHBT amplifier in G-band frequencies applications. (paper)

Oxide bipolar electronics: materials, devices and circuits

International Nuclear Information System (INIS)

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

2016-01-01

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 ZnCo 2 O 4 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. (topical review)

Electrochemical Properties of Current Collector in the All-vanadium Redox Flow Battery

International Nuclear Information System (INIS)

Hwang, Gan-Jin; Oh, Yong-Hwan; Ryu, Cheol-Hwi; Choi, Ho-Sang

2014-01-01

Two commercial carbon plates were evaluated as a current collector (bipolar plate) in the all vanadium redox-flow battery (V-RFB). The performance properties of V-RFB were test in the current density of 60 mA/cm 2 . The electromotive forces (OCV at SOC 100%) of V-RFB using A and B current collector were 1.47 V and 1.54 V. The cell resistance of V-RFB using A current collector was 4.44-5.00 Ω·cm 2 and 3.28-3.75 Ω·cm 2 for charge and discharge, respectively. The cell resistance of V-RFB using B current collector was 4.19-4.42Ω·cm 2 and 4.71-5.49Ω·cm 2 for charge and discharge, respectively. The performance of V-RFB using each current collector was evaluated. The performance of V-RFB using A current collector was 93.1%, 76.8% and 71.4% for average current efficiency, average voltage efficiency and average energy efficiency, respectively. The performance of V-RFB using B current collector was 96.4%, 73.6% and 71.0% for average current efficiency, average voltage efficiency and average energy efficiency, respectively

22.5% efficient silicon heterojunction solar cell with molybdenum oxide hole collector

OpenAIRE

Geissbühler Jonas; Werner Jérémie; Martin de Nicolas Silvia; Barraud Loris; Hessler-Wyser Aïcha; Despeisse Matthieu; Nicolay Sylvain; Tomasi Andrea; Niesen Bjoern; De Wolf Stefaan; Ballif Christophe

2015-01-01

Substituting the doped amorphous silicon films at the front of silicon heterojunction solar cells with wide bandgap transition metal oxides can mitigate parasitic light absorption losses. This was recently proven by replacing p type amorphous silicon with molybdenum oxide films. In this article we evidence that annealing above 130?°C—often needed for the curing of printed metal contacts—detrimentally impacts hole collection of such devices. We circumvent this issue by using electrodeposited c...

Probability density of tunneled carrier states near heterojunctions calculated numerically by the scattering method.

Energy Technology Data Exchange (ETDEWEB)

Wampler, William R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Myers, Samuel M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Modine, Normand A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-09-01

The energy-dependent probability density of tunneled carrier states for arbitrarily specified longitudinal potential-energy profiles in planar bipolar devices is numerically computed using the scattering method. Results agree accurately with a previous treatment based on solution of the localized eigenvalue problem, where computation times are much greater. These developments enable quantitative treatment of tunneling-assisted recombination in irradiated heterojunction bipolar transistors, where band offsets may enhance the tunneling effect by orders of magnitude. The calculations also reveal the density of non-tunneled carrier states in spatially varying potentials, and thereby test the common approximation of uniform- bulk values for such densities.

Validation of the Seven Up Seven Down Inventory in bipolar offspring : screening and prediction of mood disorders. Findings from the Dutch Bipolar Offspring Study

NARCIS (Netherlands)

Mesman, E; Youngstrom, E A; Juliana, N K; Nolen, W A; Hillegers, M H J

2016-01-01

OBJECTIVE: To validate the Seven Up Seven Down (7U7D), an abbreviated version of the General Behavior Inventory (GBI), as screener for mood disorders and test its ability to predict mood disorders over time in individuals at risk for bipolar disorder (BD). METHODS: Bipolar offspring (n=108) were

Validation of the Seven Up Seven Down Inventory in bipolar offspring : screening and prediction of mood disorders. Findings from the Dutch Bipolar Offspring Study

NARCIS (Netherlands)

Mesman, Esther; Youngstrom, E. A.; Juliana, N. K.; Nolen, W. A.; Hillegers, M. H. J.

2017-01-01

Objective: To validate the Seven Up Seven Down (7U7D), an abbreviated version of the General Behavior Inventory (GBI), as screener for mood disorders and test its ability to predict mood disorders over time in individuals at risk for bipolar disorder (BD). Methods: Bipolar offspring (n=108) were

Five-year follow-up of cognitive impairment in older adults with bipolar disorder.

Science.gov (United States)

Schouws, Sigfried N T M; Comijs, Hannie C; Dols, Annemieke; Beekman, Aartjan T F; Stek, Max L

2016-03-01

To date, cognitive impairment has been thought to be an integral part of bipolar disorder. In clinical staging models, cognitive impairment is one of the hallmarks to define the clinical stage and it plays an important role in identifying the risk factors for progression to later stages of the illness. It is important to examine neurocognitive performance over longer periods to test the hypothesis of neuroprogression of bipolar disorder. A comprehensive neuropsychological test battery was applied at baseline and five years later to 56 euthymic older outpatients with bipolar disorder (mean age = 68.35 years, range: 60-90 years) and to a demographically matched sample of 44 healthy subjects. A group-by-time repeated measures multivariate analysis of variance was performed to measure changes over time for the two groups. The impact of baseline illness characteristics on the intra-individual change in neurocognitive performance within the bipolar disorder group was studied by using logistic regression analysis. At baseline and at follow-up, patients with bipolar disorder performed worse on all neurocognitive measures compared to the matched healthy subjects. However, there was no significant group-by-time interaction between the patients with bipolar disorder and the comparison group. Although older patients with bipolar disorder had worse cognitive function than healthy subjects, they did not have greater cognitive decline over a five-year period. The change in acquired cognitive impairment of patients with bipolar disorder might parallel the cognitive development as seen in normal aging. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Dutch Bipolar Offspring Study: 12-Year Follow-Up

OpenAIRE

Mesman, Esther; Nolen, Willem A.; Reichart, Catrien G.; Wals, Marjolein; Hillegers, Manon N. J.

2013-01-01

Objective: Offspring of bipolar parents have a genetically increased risk of developing mood disorders. In a longitudinal study, the authors followed a bipolar offspring cohort from adolescence into adulthood to determine the onset, prevalence, and early course of mood disorders and other psychopathology. Method: The Dutch bipolar offspring cohort is a fixed cohort initiated in 1997 (N=140; age range at baseline, 12-21 years). Bipolar offspring were psychiatrically evaluated at baseline and a...

Lateral n-p-n bipolar transistors by ion implantation into semi-insulating GaAs

International Nuclear Information System (INIS)

Canfield, P.; Forbes, L.

1988-01-01

GaAs bipolar transistors have not seen the major development effort that GaAs MESFETs have due primarily to the short minority carrier lifetimes in GaAs. The short minority carrier lifetimes require that the base region be very thin which, if done by implantation, requires that the doping be high to obtain a well defined base profile. These requirements are very difficult to achieve in GaAs and typically, if high current gain and high speed are desired for a bipolar technology, then heterostructure bipolars are the appropriate technology, although the cost of heterostructure devices will be prohibitive for some time to come. For applications requiring low current gain, more modest fabrication rules can be followed. Lateral bipolars are particularly attractive since they would be easier to fabricate than a planar bipolar or a heterojunction bipolar. Lateral bipolars do not require steps or deep contacts to make contact with the subcollector or highly doped very thin epilayers for the base region and they can draw upon the semi-insulating properties of the GaAs substrates for device isolation. Bipolar transistors are described and shown to work successfully. (author)

A study of s new power semiconductor insulated gate bipolar transistor (IGBT) characteristics and its application to automotive ignition

International Nuclear Information System (INIS)

Rabah, K.V.O.

1995-05-01

Assessment has been made of the problem of the on-resistance and temperature effects in the three power transistor combinations, such as Darlington-types or IGBT. The IGBT is a device in which the drain of the MOSFET feeds the bipolar base in monolithic (IC and Power on the same chip) to give it both the MOS and bipolar advantages. The high temperature operating characteristics of the device are discussed and compared to that of power bipolar transistor. Unlike the power bipolar transistor whose operating current density shows current crowding at above forward collector current of 4Amps and forward voltage drop above 0.4V, the IGBT is found to maintain its high current density above forward collector of current 1Amp (or a forward voltage drop above 1.2V). The results also indicate that these devices (IGBTs) can be interdigited (paralleled) without current hogging problems if the forward conduction occurs at forward voltage drops in excess of 1.2V, and this makes it the best candidate for automotive ignition power switches. (author). 20 refs, 10 figs, 1 tab

Comparison of the optics of non-tracking and novel types of tracking solar thermal collectors for process heat applications up to 300{sup o}C

Energy Technology Data Exchange (ETDEWEB)

Grass, C.; Schoelkopf, W.; Staudacher, L.; Hacker, Z. [Bavarian Centre for Applied Energy Research, ZAE Bayern Division 4, Garching (Germany)

2004-03-01

Evacuated CPC (compound parabolic concentrator) collectors with non-tracking reflectors are compared with two novel tracking collectors: a parabolic trough and an evacuated tube collector with integrated tracking reflector. Non-tracking low concentrating CPC collectors are mostly mounted in east-west direction with a latitude dependent slope angle. They are suitable at most for working temperatures up to 200-250 {sup o}C. We present a tracking evacuated tube-collector with a trough-like concentrating mirror. Single-axis tracking of the mirror is realized with a magnetic mechanism. The mirror is mounted inside the evacuated tube and hence protected from environmental influences. One axis tracking in combination with a small acceptance angle allows for higher concentration as compared to non-tracking concentrating collectors. Ray-tracing analysis shows a half acceptance angle of about 5.7{sup o} at geometrical concentration ratio of 3.2. Losses of well constructed evacuated tube collectors (heat conductivity through the manifolds inside the thermally insulated terminating housing are low) are dominated by radiation losses of the absorber. Hence, reducing the absorber size can lead to higher efficiencies at high operating temperature levels. With the presented collector we aim for operating temperatures up to 350 {sup o}C. At temperatures of 300 {sup o}C we expect with anti-reflective coating of the glass tube and a selective absorber coating efficiencies of 0.65. This allows for application in industrial process heat generation, high efficient solar cooling and power generation. A first prototype, equipped with a standard glass tube and a black paint absorber coating, was tested at ZAE Bayern. The optical efficiency was measured to be 0.71. This tube-collector is compared by ray-tracing with non-tracking market available tube-collectors with geometrical concentration ratios up to 1.1 and with a low cost parabolic trough collector of Industrial Solar Technology (IST

Operation of resonant-tunneling diodes with strong back injection from the collector at frequencies up to 1.46 THz

International Nuclear Information System (INIS)

Feiginov, Michael; Kanaya, Hidetoshi; Suzuki, Safumi; Asada, Masahiro

2014-01-01

In search for possibilities to increase the operating frequencies of resonant-tunneling diodes (RTDs), we are studying RTDs working in an unusual regime. The collector side of our diodes is so heavily doped that the collector depletion region is fully eliminated in our RTDs and the ground quantum-well subband stays immersed under (or stays close to) the collector quasi-Fermi level. The electron injection from the collector into the RTD quantum well is very strong in our diodes and stays comparable to that from the emitter in the whole range of RTD operating biases. Our RTDs exhibit well pronounced negative-differential-conductance region and peak-to-valley current ratio around 1.8. We demonstrate operation of our diodes in RTD oscillators up to 1.46 THz. We also observe a fine structure in the emission spectra of our RTD oscillators, when they are working in the regime close to the onset of oscillations.

Maximizing ion current rectification in a bipolar conical nanopore fluidic diode using optimum junction location.

Science.gov (United States)

Singh, Kunwar Pal

2016-10-12

The ion current rectification has been obtained as a function of the location of a heterojunction in a bipolar conical nanopore fluidic diode for different parameters to determine the junction location for maximum ion current rectification using numerical simulations. Forward current peaks for a specific location of the junction and reverse current decreases with the junction location due to a change in ion enrichment/depletion in the pore. The optimum location of the heterojunction shifts towards the tip with base/tip diameter and surface charge density, and towards the base with the electrolyte concentration. The optimum location of the heterojunction has been approximated by an equation as a function of pore length, base/tip diameter, surface charge density and electrolyte concentration. The study is useful to design a rectifier with maximum ion current rectification for practical purposes.

Atomically precise graphene nanoribbon heterojunctions from a single molecular precursor

Science.gov (United States)

Nguyen, Giang D.; Tsai, Hsin-Zon; Omrani, Arash A.; Marangoni, Tomas; Wu, Meng; Rizzo, Daniel J.; Rodgers, Griffin F.; Cloke, Ryan R.; Durr, Rebecca A.; Sakai, Yuki; Liou, Franklin; Aikawa, Andrew S.; Chelikowsky, James R.; Louie, Steven G.; Fischer, Felix R.; Crommie, Michael F.

2017-11-01

The rational bottom-up synthesis of atomically defined graphene nanoribbon (GNR) heterojunctions represents an enabling technology for the design of nanoscale electronic devices. Synthetic strategies used thus far have relied on the random copolymerization of two electronically distinct molecular precursors to yield GNR heterojunctions. Here we report the fabrication and electronic characterization of atomically precise GNR heterojunctions prepared through late-stage functionalization of chevron GNRs obtained from a single precursor. Post-growth excitation of fully cyclized GNRs induces cleavage of sacrificial carbonyl groups, resulting in atomically well-defined heterojunctions within a single GNR. The GNR heterojunction structure was characterized using bond-resolved scanning tunnelling microscopy, which enables chemical bond imaging at T = 4.5 K. Scanning tunnelling spectroscopy reveals that band alignment across the heterojunction interface yields a type II heterojunction, in agreement with first-principles calculations. GNR heterojunction band realignment proceeds over a distance less than 1 nm, leading to extremely large effective fields.

A study of process-related electrical defects in SOI lateral bipolar transistors fabricated by ion implantation

Science.gov (United States)

Yau, J.-B.; Cai, J.; Hashemi, P.; Balakrishnan, K.; D'Emic, C.; Ning, T. H.

2018-04-01

We report a systematic study of process-related electrical defects in symmetric lateral NPN transistors on silicon-on-insulator (SOI) fabricated using ion implantation for all the doped regions. A primary objective of this study is to see if pipe defects (emitter-collector shorts caused by locally enhanced dopant diffusion) are a show stopper for such bipolar technology. Measurements of IC-VCE and Gummel currents in parallel-connected transistor chains as a function of post-fabrication rapid thermal anneal cycles allow several process-related electrical defects to be identified. They include defective emitter-base and collector-base diodes, pipe defects, and defects associated with a dopant-deficient region in an extrinsic base adjacent its intrinsic base. There is no evidence of pipe defects being a major concern in SOI lateral bipolar transistors.

Staying well with bipolar disorder: A qualitative analysis of five-year follow-up interviews with young people.

Science.gov (United States)

Crowe, M; Inder, M

2018-05-01

WHAT IS ALREADY KNOWN ABOUT THE TOPIC?: Bipolar disorder is a long-term condition which causes ongoing disruptions to the individual's life. Current evidence suggests that a combination of medication in combination with psychotherapy is more effective than medication alone. WHAT THE PAPER ADDS TO EXISTING KNOWLEDGE?: There are few published reports of the effects of interventions (pharmacological or psychotherapeutic) for treatment in bipolar disorder. While both psychotherapies provided a framework for understanding bipolar disorder each had specific strategies that participants identified as effective. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Because bipolar disorder is a long-term condition, its treatment needs to incorporate psychotherapeutic approaches that address the unique nature of its impact on each individual and provide individualized strategies for managing the disorder. Both Interpersonal and Social Rhythm Therapy and Specialist Supportive Care provide strategies that promote personal recovery. Introduction The primary outcomes from this study of psychotherapy for young people with bipolar disorder identified that most participants had continued to remain well. Given that up to 80% of people relapse within 2 years, it was important to establish how these participants described the process of staying well. Aim To examine how participants in a psychotherapy for young people with bipolar disorder study at 5-year follow-up described their experiences of the intervention and its impact on living with the disorder. Methods This qualitative study was conducted 5 years after participants had completed a psychotherapy intervention in a randomized controlled trial for young people with bipolar disorder. Thirty people were recruited into this qualitative study and interviewed regarding their experiences. The data were analysed using an inductive thematic analysis. Findings Three themes were identified from the data: self-awareness in the context of bipolar

High Detectivity Graphene-Silicon Heterojunction Photodetector.

Science.gov (United States)

Li, Xinming; Zhu, Miao; Du, Mingde; Lv, Zheng; Zhang, Li; Li, Yuanchang; Yang, Yao; Yang, Tingting; Li, Xiao; Wang, Kunlin; Zhu, Hongwei; Fang, Ying

2016-02-03

A graphene/n-type silicon (n-Si) heterojunction has been demonstrated to exhibit strong rectifying behavior and high photoresponsivity, which can be utilized for the development of high-performance photodetectors. However, graphene/n-Si heterojunction photodetectors reported previously suffer from relatively low specific detectivity due to large dark current. Here, by introducing a thin interfacial oxide layer, the dark current of graphene/n-Si heterojunction has been reduced by two orders of magnitude at zero bias. At room temperature, the graphene/n-Si photodetector with interfacial oxide exhibits a specific detectivity up to 5.77 × 10(13) cm Hz(1/2) W(-1) at the peak wavelength of 890 nm in vacuum, which is highest reported detectivity at room temperature for planar graphene/Si heterojunction photodetectors. In addition, the improved graphene/n-Si heterojunction photodetectors possess high responsivity of 0.73 A W(-1) and high photo-to-dark current ratio of ≈10(7) . The current noise spectral density of the graphene/n-Si photodetector has been characterized under ambient and vacuum conditions, which shows that the dark current can be further suppressed in vacuum. These results demonstrate that graphene/Si heterojunction with interfacial oxide is promising for the development of high detectivity photodetectors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Dutch Bipolar Offspring Study : 12-Year Follow-Up

NARCIS (Netherlands)

Mesman, Esther; Nolen, Willem A.; Reichart, Catrien G.; Wals, Marjolein; Hillegers, Manon N. J.

Objective: Offspring of bipolar parents have a genetically increased risk of developing mood disorders. In a longitudinal study, the authors followed a bipolar offspring cohort from adolescence into adulthood to determine the onset, prevalence, and early course of mood disorders and other

GaAs integrated circuits and heterojunction devices

Science.gov (United States)

Fowlis, Colin

1986-06-01

The state of the art of GaAs technology in the U.S. as it applies to digital and analog integrated circuits is examined. In a market projection, it is noted that whereas analog ICs now largely dominate the market, in 1994 they will amount to only 39 percent vs. 57 percent for digital ICs. The military segment of the market will remain the largest (42 percent in 1994 vs. 70 percent today). ICs using depletion-mode-only FETs can be constructed in various forms, the closest to production being BFL or buffered FET logic. Schottky diode FET logic - a lower power approach - can reach higher complexities and strong efforts are being made in this direction. Enhancement type devices appear essential to reach LSI and VLSI complexity, but process control is still very difficult; strong efforts are under way, both in the U.S. and in Japan. Heterojunction devices appear very promising, although structures are fairly complex, and special fabrication techniques, such as molecular beam epitaxy and MOCVD, are necessary. High-electron-mobility-transistor (HEMT) devices show significant performance advantages over MESFETs at low temperatures. Initial results of heterojunction bipolar transistor devices show promise for high speed A/D converter applications.

Twenty year multi-follow-up of different types of hallucinations in schizophrenia, schizoaffective disorder, bipolar disorder, and depression.

Science.gov (United States)

Goghari, Vina M; Harrow, Martin

2016-10-01

Hallucinations are a salient feature of both psychotic and mood disorders. Currently there is a call for more research on the phenomenology of different forms of hallucinations, in a broader array of disorders, to further both theoretical knowledge and clinical utility. We investigated auditory, visual, and olfactory hallucinations at index hospitalization and auditory and visual hallucinations prospectively for 20years in 150 young patients, namely 51 schizophrenia, 25 schizoaffective, 28 bipolar, and 79 unipolar depression. For the index hospitalization, the data showed schizophrenia and schizoaffective patients had a greater rate of auditory and visual hallucinations than bipolar and depression patients. However, over the longitudinal trajectory of their illness, a greater percentage of schizophrenia patients had auditory and visual hallucinations than schizoaffective patients, as well as bipolar and depression patients. Also, in contrast to the initial period, schizoaffective patients did not differentiate themselves over the follow-up period from bipolar patients. Bipolar and depression patients did not significantly differ at index hospitalization or at follow-up. We found visual hallucinations differentiated the groups to a greater degree over the 20year course than did auditory hallucinations. These findings suggest the longitudinal course is more important for differentiating schizophrenia and schizoaffective disorder, whereas the initial years may be more useful to differentiate schizoaffective disorder from bipolar disorder. Furthermore, we found that the early presence of auditory hallucinations was associated with a reduced likelihood for a future period of recovery. No olfactory hallucinations were present at the index hospitalization in any patients. Over the course of 20years, a minority of schizophrenia patients presented with olfactory hallucinations, and very few schizoaffective and bipolar patients presented with olfactory hallucinations. This

Graphene-based heterojunction photocatalysts

Science.gov (United States)

Li, Xin; Shen, Rongchen; Ma, Song; Chen, Xiaobo; Xie, Jun

2018-02-01

Due to their unique physicochemical, optical and electrical properties, 2D semimetallic or semiconducting graphene has been extensively utilized to construct highly efficient heterojunction photocatalysts for driving a variety of redox reactions under proper light irradiation. In this review, we carefully addressed the fundamental mechanism of heterogeneous photocatalysis, fundamental properties and advantages of graphene in photocatalysis, and classification and comparison of graphene-based heterojunction photocatalysts. Subsequently, we thoroughly highlighted and discussed various graphene-based heterojunction photocatalysts, including Schottky junctions, Type-II heterojunctions, Z-scheme heterojunctions, Van der Waals heterostructures, in plane heterojunctions and multicomponent heterojunctions. Several important photocatalytic applications, such as photocatalytic water splitting (H2 evolution and overall water splitting), degradation of pollutants, carbon dioxide reduction and bacteria disinfection, are also summarized. Through reviewing the important advances on this topic, it may inspire some new ideas for exploiting highly effective graphene-based heterojunction photocatalysts for a number of applications in photocatlysis and other fields, such as photovoltaic, (photo)electrocatalysis, lithium battery, fuel cell, supercapacitor and adsorption separation.

Large-signal modeling of multi-finger InP DHBT devices at millimeter-wave frequencies

DEFF Research Database (Denmark)

Johansen, Tom Keinicke; Midili, Virginio; Squartecchia, Michele

2017-01-01

A large-signal modeling approach has been developed for multi-finger devices fabricated in an Indium Phosphide (InP) Double Heterojunction Bipolar Transistor (DHBT) process. The approach utilizes unit-finger device models embedded in a multi-port parasitic network. The unit-finger model is based...... on an improved UCSD HBT model formulation avoiding an erroneous RciCbci transit-time contribution from the intrinsic collector region as found in other III-V based HBT models. The mutual heating between fingers is modeled by a thermal coupling network with parameters extracted from electro-thermal simulations...

High-performance photoresponse from single-walled carbon nanotube-zinc oxide heterojunctions

International Nuclear Information System (INIS)

Chang, Jingbo; Najeeb, Choolakadavil Khalid; Lee, Jae-Hyeok; Lee, Minsu; Kim, Jae-Ho

2011-01-01

Photoactive materials consisting of single-walled carbon nanotube (SWNT)-zinc oxide (ZnO) heterojunctions targeted for optoelectronic applications are investigated in terms of photoresponse and photovoltaic effects. The devices based on SWNT-ZnO heterojunction films are fabricated by two step processes: first, a well aligned SWNT monolayer is deposited on an oxide substrate by the Langmuir-Blodgett (LB) technique; then a ZnO film prepared by filtration of ZnO nanowire solution is transferred onto the SWNT film to form SWNT-ZnO junctions. The SWNT-ZnO heterojunction demonstrates faster photoresponse time (2.75 s) up to 18 times and photovoltaic efficiency (1.33 nA) up to 4 times higher than that of only a ZnO device. Furthermore, the mechanisms of UV sensitivity enhancement and photovoltaic effects are explained according to the high electron mobility in the SWNT-ZnO heterojunctions.

Diagnostic consistency and interchangeability of schizophrenic disorders and bipolar disorders: A 7-year follow-up study.

Science.gov (United States)

Hung, Yen-Ni; Yang, Shu-Yu; Kuo, Chian-Jue; Lin, Shih-Ku

2018-03-01

The change in psychiatric diagnoses in clinical practice is not an unusual phenomenon. The interchange between the diagnoses of schizophrenic disorders and bipolar disorders is a major clinical issue because of the differences in treatment regimens and long-term prognoses. In this study, we used a nationwide population-based sample to compare the diagnostic consistency and interchange rate between schizophrenic disorders and bipolar disorders. In total, 25 711 and 11 261 patients newly diagnosed as having schizophrenic disorder and bipolar disorder, respectively, were retrospectively enrolled from the Psychiatric Inpatient Medical Claims database between 2001 and 2005. We followed these two cohorts for 7 years to determine whether their diagnoses were consistent throughout subsequent hospitalizations. The interchange between the two diagnoses was analyzed. In the schizophrenic disorder cohort, the overall diagnostic consistency rate was 87.3% and the rate of change to bipolar disorder was 3.0% during the 7-year follow-up. Additional analyses of subtypes revealed that the change rate from schizoaffective disorder to bipolar disorder was 12.0%. In the bipolar disorder cohort, the overall diagnostic consistency rate was 71.9% and the rate of change to schizophrenic disorder was 8.3%. Changes in the diagnosis of a major psychosis are not uncommon. The interchange between the diagnoses of schizophrenic disorders and bipolar disorders might be attributed to the evolution of clinical symptoms and the observation of preserved social functions that contradict the original diagnosis. While making a psychotic diagnosis, clinicians should be aware of the possibility of the change in diagnosis in the future. © 2017 The Authors. Psychiatry and Clinical Neurosciences © 2017 Japanese Society of Psychiatry and Neurology.

Hybrid organic-inorganic heterojunctions for photovoltaic applications

OpenAIRE

Dietmüller, Roland

2012-01-01

Hybrid organic-inorganic bulk heterojunction solar cells based on silicon nanocrystals (Si-nc) have been realized and investigated. A photo-induced charge transfer could be demonstrated in composites made of silicon nanocrystals and poly(3-hexylthiophene) (P3HT) or [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) via light-induced electron spin resonance measurements. With bulk heterojunction solar cells made of P3HT/Si-nc composites in a sandwich structure, open-circuit voltages of up to 0....

Tube collector with integrated tracking parabolic concentrator

Energy Technology Data Exchange (ETDEWEB)

Grass, C.; Benz, N.; Hacker, Z.; Timinger, A. [ZAE Bayern, Bavarian Centre for Applied Energy Research, Muenchen (Germany)

2000-07-01

Low concentrating CPC collectors usually do not track the sun and are mounted in east-west direction with a latitude dependent slope angle. They are most suitable for maximum working temperatures up to 200 250 deg. C. We present a novel evacuated tube-collector with a trough-like concentrating mirror. Single-axis tracking of the mirror is realized with a magnetic mechanism. The mirror is mounted inside the evacuated tube and hence protected from environmental influences. One axis tracking in combination with a small acceptance angle allows for higher concentration as compared to non-tracking concentrating collectors. Ray-tracing analysis shows a half acceptance angle of about 5 deg. at a geometrical concentration ratio of 3.2. The losses of evacuated tube collectors are dominated by the radiation losses of the absorber. Hence, reducing the absorber size can lead to higher efficiencies at high operating temperature levels. With the presented collector we aim for operating temperatures up to 400 deg. C. At temperatures of 300 deg. C we expect efficiencies of 65 %. This allows for application in industrial process heat generation, high efficient solar cooling and power generation. A first prototype was tested at the ZAE Bayern. The optical efficiency was measured to be 75 %. (au)

Dielectric properties investigation of Cu2O/ZnO heterojunction thin films by electrodeposition

International Nuclear Information System (INIS)

Li, Qiang; Xu, Mengmeng; Fan, Huiqing; Wang, Hairong; Peng, Biaolin; Long, Changbai; Zhai, Yuchun

2013-01-01

Highlights: ► Bottom-up self-assembly Cu 2 O/ZnO heterojunction was fabricated by electrochemical deposition on indium tin oxide (ITO) flexible substrate (polyethylene terephthalate-PET). ► The dielectric response of Cu 2 O/ZnO heterojunction thin films had been investigated. ► The universal dielectric response was used to investigate the hopping behavior in Cu 2 O/ZnO heterojunction. -- Abstract: Structures and morphologies of the Cu 2 O/ZnO heterojunction electrodeposited on indium tin oxide (ITO) flexible substrate (polyethylene terephthalate-PET) were investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), high resolution transmission electron microscopy (HRTEM), respectively. The dielectric response of bottom-up self-assembly Cu 2 O/ZnO heterojunction was investigated. The low frequency dielectric dispersion (LFDD) was observed. The universal dielectric response (UDR) was used to investigate the frequency dependence of dielectric response for Cu 2 O/ZnO heterojunction, which was attributed to the long range and the short range hopping charge carriers at the low frequency and the high frequency region, respectively

Low cost bipolar current collector-separator for electrochemical cells

International Nuclear Information System (INIS)

Lawrence, R.

1980-01-01

A bipolar current collecting, cell separating element for electrochemical cells for conducting current from the anode electrode of one cell unit to cathode electrode of the adjacent cell unit comprises: (A) a pressure mold aggregate of electrically conductive carbon/graphite particles and thermoplastic fluorocarbon polymer resin particles in a weight ratio of 2.5:1 to 16:1 whereby said molded aggregated has a bulk resistivity which is less than 4x10 -3 ohm/inch, (B) said molded aggregate having a fluid imprevious main body, at least one recessed chamber on one side of said main body and a plurality of spaced, conductive projections extending from the base of said chamber for contacting and permitting current flow between the electrode of adjacent cell unit, and (C) means communicating with said recessed chambers to permit introduction and removal of fluids

Bioinspired plate-based fog collectors.

Science.gov (United States)

Heng, Xin; Luo, Cheng

2014-09-24

In a recent work, we explored the feeding mechanism of a shorebird to transport liquid drops by repeatedly opening and closing its beak. In this work, we apply the corresponding results to develop a new artificial fog collector. The collector includes two nonparallel plates. It has three advantages in comparison with existing artificial collectors: (i) easy fabrication, (ii) simple design to scale up, and (iii) active transport of condensed water drops. Two collectors have been built. A small one with dimensions of 4.2 × 2.1 × 0.05 cm(3) (length × width × thickness) was first built and tested to examine (i) the time evolution of condensed drop sizes and (ii) the collection processes and efficiencies on the glass, SiO2, and SU-8 plates. Under similar experimental conditions, the amount of water collected per unit area on the small collector is about 9.0, 4.7, and 3.7 times, respectively, as much as the ones reported for beetles, grasses, and metal wires, and the total amount of water collected is around 33, 18, and 15 times. On the basis of the understanding gained from the tests on the small collector, a large collector with dimensions of 26 × 10 × 0.2 cm(3) was further built and tested, which was capable of collecting 15.8 mL of water during a period of 36 min. The amount of water collected, when it is scaled from 36 to 120 min, is about 878, 479, or 405 times more than what was collected by individual beetles, grasses, or metal wires.

Hierarchical On-Surface Synthesis of Deterministic Graphene Nanoribbon Heterojunctions

OpenAIRE

Bronner, Christopher; Durr, Rebecca A.; Rizzo, Daniel J.; Lee, Yea-Lee; Marangoni, Tomas; Kalayjian, Alin Miksi; Rodriguez, Henry; Zhao, William; Louie, Steven G.; Fischer, Felix R.; Crommie, Michael F.

2017-01-01

Bottom-up graphene nanoribbon (GNR) heterojunctions are nanoscale strips of graphene whose electronic structure abruptly changes across a covalently bonded interface. Their rational design offers opportunities for profound technological advancements enabled by their extraordinary structural and electronic properties. Thus far the most critical aspect of their synthesis, the control over sequence and position of heterojunctions along the length of a ribbon, has been plagued by randomness in mo...

Resilience dimensions and mental health outcomes in bipolar disorder in a follow-up study.

Science.gov (United States)

Echezarraga, A; Calvete, E; González-Pinto, A M; Las Hayas, C

2018-02-01

The individual process of resilience has been related to positive outcomes in mental disorders. We aimed (a) to identify the resilience domains from the Resilience Questionnaire for Bipolar Disorder that are associated cross sectionally and longitudinally with mental health outcomes in bipolar disorder (BD) and (b) to explore cross-lagged associations among resilience factors. A clinical adult sample of 125 patients diagnosed with BD (62.10% female, mean age = 46.13, SD = 10.89) gave their informed consent and completed a battery of disease-specific tools on resilience, personal recovery, symptomatology, psychosocial functioning, and quality of life, at baseline and at follow-up (n = 63, 58.10% female, mean age = 45.13, SD = 11.06, participation rate = 50.40%). Resilience domains of self-management of BD, turning point, self-care, and self-confidence were significantly associated with mental health indicators at baseline. In addition, self-confidence at baseline directly predicted an increase in personal recovery at follow-up, and self-confidence improvement mediated the relationship between interpersonal support and self-care at baseline and personal recovery at follow-up. These findings highlight that resilience domains are significantly associated with positive mental health outcomes in BD and that some predict personal recovery at follow-up. Moreover, some resilience factors improve other resilience factors over time. Copyright © 2017 John Wiley & Sons, Ltd.

Generation of short electrical pulses based on bipolar transistorsny

Directory of Open Access Journals (Sweden)

M. Gerding

2004-01-01

Full Text Available A system for the generation of short electrical pulses based on the minority carrier charge storage and the step recovery effect of bipolar transistors is presented. Electrical pulses of about 90 ps up to 800 ps duration are generated with a maximum amplitude of approximately 7V at 50Ω. The bipolar transistor is driven into saturation and the base-collector and base-emitter junctions become forward biased. The resulting fast switch-off edge of the transistor’s output signal is the basis for the pulse generation. The fast switching of the transistor occurs as a result of the minority carriers that have been injected and stored across the base-collector junction under forward bias conditions. If the saturated transistor is suddenly reverse biased the pn-junction will appear as a low impedance until the stored charge is depleted. Then the impedance will suddenly increase to its normal high value and the flow of current through the junction will turn to zero, abruptly. A differentiation of the output signal of the transistor results in two short pulses with opposite polarities. The differentiating circuit is implemented by a transmission line network, which mainly acts as a high pass filter. Both the transistor technology (pnp or npn and the phase of the transfer function of the differentating circuit influence the polarity of the output pulses. The pulse duration depends on the transistor parameters as well as on the transfer function of the pulse shaping network. This way of generating short electrical pulses is a new alternative for conventional comb generators based on steprecovery diodes (SRD. Due to the three-terminal structure of the transistor the isolation problem between the input and the output signal of the transistor network is drastically simplified. Furthermore the transistor is an active element in contrast to a SRD, so that its current gain can be used to minimize the power of the driving signal.

Progression along the Bipolar Spectrum: A Longitudinal Study of Predictors of Conversion from Bipolar Spectrum Conditions to Bipolar I and II Disorders

Science.gov (United States)

Alloy, Lauren B.; Urošević, Snežana; Abramson, Lyn Y.; Jager-Hyman, Shari; Nusslock, Robin; Whitehouse, Wayne G.; Hogan, Michael

2011-01-01

Little longitudinal research has examined progression to more severe bipolar disorders in individuals with “soft” bipolar spectrum conditions. We examine rates and predictors of progression to bipolar I and II diagnoses in a non-patient sample of college-age participants (n = 201) with high General Behavior Inventory scores and childhood or adolescent onset of “soft” bipolar spectrum disorders followed longitudinally for 4.5 years from the Longitudinal Investigation of Bipolar Spectrum (LIBS) project. Of 57 individuals with initial cyclothymia or bipolar disorder not otherwise specified (BiNOS) diagnoses, 42.1% progressed to a bipolar II diagnosis and 10.5% progressed to a bipolar I diagnosis. Of 144 individuals with initial bipolar II diagnoses, 17.4% progressed to a bipolar I diagnosis. Consistent with hypotheses derived from the clinical literature and the Behavioral Approach System (BAS) model of bipolar disorder, and controlling for relevant variables (length of follow-up, initial depressive and hypomanic symptoms, treatment-seeking, and family history), high BAS sensitivity (especially BAS Fun Seeking) predicted a greater likelihood of progression to bipolar II disorder, whereas early age of onset and high impulsivity predicted a greater likelihood of progression to bipolar I (high BAS sensitivity and Fun-Seeking also predicted progression to bipolar I when family history was not controlled). The interaction of high BAS and high Behavioral Inhibition System (BIS) sensitivities also predicted greater likelihood of progression to bipolar I. We discuss implications of the findings for the bipolar spectrum concept, the BAS model of bipolar disorder, and early intervention efforts. PMID:21668080

Experimental study on short-circuit characteristics of the new protection circuit of insulated gate bipolar transistor

International Nuclear Information System (INIS)

Ji, In-Hwan; Choi, Young-Hwan; Ha, Min-Woo; Han, Min-Koo; Choi, Yearn-Ik

2006-01-01

A new protection circuit employing the collector to emitter voltage (V CE ) sensing scheme for short-circuit withstanding capability of the insulated gate bipolar transistor (IGBT) is proposed and verified by experimental results. Because the current path between the gate and collector can be successfully eliminated in the proposed protection circuit, the power consumption can be reduced and the gate input impedance can be increased. Previous study is limited to dc characteristics. However, experimental results show that the proposed protection circuit successfully reduces the over-current of main IGBT by 80.4% under the short-circuit condition

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…

Integrated Design of Undepressed Collector for Low Power Gyrotron

Science.gov (United States)

Kumar, Anil; Goswami, Uttam K.; Poonia, Sunita; Singh, Udaybir; Kumar, Nitin; Alaria, M. K.; Bera, A.; Khatun, Hasina; Sinha, A. K.

2011-06-01

A 42 GHz, 200 kW continuous wave (CW) gyrotron, operating at TE03 mode is under development for the electron cyclotron resonance plasma heating of the Indian TOKAMAK system. The gyrotron is made up of an undepressed collector. The undepressed collector is simple to design and cost effective. In this paper, a detailed design study of the undepressed collector for the 42 GHz gyrotron is presented. The EGUN code is used to analyze the spent electron beam trajectory for the maximum spread to reduce the power loading on the collector surface. To achieve wall loading ≤1 kW/cm2, a collector with a length of 800 mm and a radius of 42.5 mm is designed. The design also includes the three magnet systems around the collector for maximum and uniform beam spread. The thermal and the structural analyses are done using the ANSYS code to optimize the collector structure and dimensions with tolerance.

Performance of solar collectors under low temperature conditions

DEFF Research Database (Denmark)

Bunea, Mircea; Eicher, Sara; Hildbrand, Catherine

The performance of four solar thermal collectors (flat plate, evacuated tube, unglazed with rear insulation and unglazed without rear insulation) was experimentally measured and simulated for temperatures below ambient. The influence of several parameters (e.g. collector inlet temperature, air...... evaluated and results compared to experimental measurements. A mathematical model is also under development to include, in addition to the condensation phenomena, the frost, the rain and the long-wave radiation gains/losses on the rear of the solar collector. While the potential gain from rain was estimated...... to be around 2%, frost heat gains were measured to be up to 40% per day, under specific conditions. Overall, results have shown that unglazed collectors are more efficient than flat plate or evacuated tube collectors at low operation temperatures or for night conditions, making them more suitable for heat pump...

Electrical characteristics of SiGe-base bipolar transistors on thin-film SOI substrates

International Nuclear Information System (INIS)

Liao, Shu-Hui; Chang, Shu-Tong

2010-01-01

This paper, based on two-dimensional simulations, provides a comprehensive analysis of the electrical characteristics of the Silicon germanium (SiGe)-base bipolar transistors on thin-film siliconon-insulator (SOI) substrates. The impact of the buried oxide thickness (T OX ), the emitter width (W E ), and the lateral distance between the edge of the intrinsic base and the reach-through region (L col ) on both the AC and DC device characteristics was analyzed in detail. Regarding the DC characteristics, the simulation results suggest that a thicker T OX gives a larger base-collector breakdown voltage (BV CEO ), whereas reducing the T OX leads to an enhanced maximum electric field at the B-C junction. As for the AC characteristics, cut-off frequency (f T ) increases slightly with increasing buried oxide thickness and finally saturates to a constant value when the buried oxide thickness is about 0.15 μm. The collector-substrate capacitance (C CS ) decreases with increasing buried oxide thickness while the maximum oscillation frequency (f max ) increases with increasing buried oxide thickness. Furthermore, the impact of self-heating effects in the device was analyzed in various areas. The thermal resistance as a function of the buried oxide thickness indicates that the thermal resistance of the SiGe-base bipolar transistor on a SOI substrate is slightly higher than that of a bulk SiGe-base bipolar transistor. The thermal resistance is reduced by ∼37.89% when the emitter width is increased by a factor of 5 for a fixed buried oxide thickness of 0.1 μm. All the results can be used to design and optimize SiGe-base bipolar transistors on SOI substrates with minimum thermal resistance to enhance device performance.

Optimal nonimaging integrated evacuated solar collector

Science.gov (United States)

Garrison, John D.; Duff, W. S.; O'Gallagher, Joseph J.; Winston, Roland

1993-11-01

A non imaging integrated evacuated solar collector for solar thermal energy collection is discussed which has the lower portion of the tubular glass vacuum enveloped shaped and inside surface mirrored to optimally concentrate sunlight onto an absorber tube in the vacuum. This design uses vacuum to eliminate heat loss from the absorber surface by conduction and convection of air, soda lime glass for the vacuum envelope material to lower cost, optimal non imaging concentration integrated with the glass vacuum envelope to lower cost and improve solar energy collection, and a selective absorber for the absorbing surface which has high absorptance and low emittance to lower heat loss by radiation and improve energy collection efficiency. This leads to a very low heat loss collector with high optical collection efficiency, which can operate at temperatures up to the order of 250 degree(s)C with good efficiency while being lower in cost than current evacuated solar collectors. Cost estimates are presented which indicate a cost for this solar collector system which can be competitive with the cost of fossil fuel heat energy sources when the collector system is produced in sufficient volume. Non imaging concentration, which reduces cost while improving performance, and which allows efficient solar energy collection without tracking the sun, is a key element in this solar collector design.

Dust collector

Energy Technology Data Exchange (ETDEWEB)

Sahourin, H.

1988-03-22

This invention relates to a dust collector or filter which may be used for large volume cleaning air for gases or for separating out industrial byproducts such as wood chips, sawdust, and shavings. It relies on filtration or separation using only a uniquely configured medium. A primary, but not exclusive, purpose of the invention is to enable very large throughput, capable of separating or filtering of gases containing up to three or more tons of byproduct with a minimum pressure-drop across the device. No preliminary cycloning, to remove major particulates is necessary. The collector generally comprises a continuous and integral filter medium which is suspended from a plurality of downwardly extending frames forming a series of separate elements having a triangular cross-section, each element being relatively wide at the top and narrow at the bottom to define, between adjacent elements, a divergent collecting space which is wide at the bottom. 11 figs.

Performance of evaporator-collector and air collector in solar assisted heat pump dryer

International Nuclear Information System (INIS)

Hawlader, M.N.A.; Rahman, S.M.A.; Jahangeer, K.A.

2008-01-01

A solar assisted heat pump dryer has been designed, fabricated and tested. This paper presents the performance of the evaporator-collector and the air collector when operated under the same meteorological conditions. ASHRAE standard procedure for collector testing has been followed. The evaporator-collector of the heat pump is acting directly as the solar collector, and the temperature of the refrigerant at the inlet to the evaporator-collector always remained below the ambient temperature. Because of the rejection of sensible and latent heats of air at the dehumidifier, the temperature at the inlet to the air collector is lower than that of the ambient air. Hence, the thermal efficiency of the air collector also increases due to a reduction of losses from the collector. The efficiencies of the evaporator-collector and the air collector were found to vary between 0.8-0.86 and 0.7-0.75, respectively, when operated under the meteorological conditions of Singapore

Depression and Bipolar Support Alliance

Science.gov (United States)

Depression and Bipolar Support Alliance Crisis Hotline Information Coping with a Crisis Suicide Prevention Information Psychiatric Hospitalization ... sign-up Education info, training, events Mood Disorders Depression Bipolar Disorder Anxiety Screening Center Co-occurring Illnesses/ ...

Connectable solar air collectors

Energy Technology Data Exchange (ETDEWEB)

Oestergaard Jensen, S.; Bosanac, M.

2002-02-01

The project has proved that it is possible to manufacture solar air collector panels, which in an easy way can be connected into large collector arrays with integrated ducting without loss of efficiency. The developed connectable solar air collectors are based on the use of matrix absorbers in the form of perforated metal sheets. Three interconnected solar air collectors of the above type - each with an transparent area of approx. 3 m{sup 2} - was tested and compared with parallel tests on two single solar air collectors also with a transparent area of approx. 3 m{sup 2} One of the single solar air collectors has an identical absorber as the connectable solar air collectors while the absorber of the other single solar air collector was a fibre cloth. The efficiency of the three solar air collectors proved to be almost identical in the investigated range of mass flow rates and temperature differences. The solar air collectors further proved to be very efficient - as efficient as the second most efficient solar air collectors tested in the IEA task 19 project Solar Air Systems. Some problems remain although to be solved: the pressure drop across especially the connectable solar air collectors is too high - mainly across the inlets of the solar air collectors. It should, however, be possible to considerably reduce the pressure losses with a more aerodynamic design of the inlet and outlet of the solar air collectors; The connectable solar air collectors are easy connectable but the air tightness of the connections in the present form is not good enough. As leakage leads to lower efficiencies focus should be put on making the connections more air tight without loosing the easiness in connecting the solar air collectors. As a spin off of the project a simple and easy way to determine the efficiency of solar, air collectors for pre-heating of fresh air has been validated. The simple method of determining the efficiency has with success been compared with an advance method

Air/liquid collectors

DEFF Research Database (Denmark)

Jensen, Søren Østergaard; Olesen, Ole; Kristiansen, Finn Harken

1997-01-01

this kind of collectors. The modified simulation program has been used for the determination of the surplus in performance which solar heating systems with this type of solar collectors for combined preheating of ventilation air and domestic hot water will have. The simulation program and the efficiency......This report determine efficiency equations for combined air/liquid solar collectors by measurements on to different air/liquid collectors. Equations which contain all relevant informations on the solar collectors. A simulation program (Kviksol) has been modified in order to be able to handle...

Plasmonic engineering of metal-oxide nanowire heterojunctions in integrated nanowire rectification units

Energy Technology Data Exchange (ETDEWEB)

Lin, Luchan; Zhou, Y. Norman, E-mail: liulei@tsinghua.edu.cn, E-mail: nzhou@uwaterloo.ca [Department of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Centre for Advanced Materials Joining, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Zou, Guisheng; Liu, Lei, E-mail: liulei@tsinghua.edu.cn, E-mail: nzhou@uwaterloo.ca [Department of Mechanical Engineering, State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Duley, Walt W. [Centre for Advanced Materials Joining, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

2016-05-16

We show that irradiation with femtosecond laser pulses can produce robust nanowire heterojunctions in coupled non-wetting metal-oxide Ag-TiO{sub 2} structures. Simulations indicate that joining arises from the effect of strong plasmonic localization in the region of the junction. Strong electric field effects occur in both Ag and TiO{sub 2} resulting in the modification of both surfaces and an increase in wettability of TiO{sub 2}, facilitating the interconnection of Ag and TiO{sub 2} nanowires. Irradiation leads to the creation of a thin layer of highly defected TiO{sub 2} in the contact region between the Ag and TiO{sub 2} nanowires. The presence of this layer allows the formation of a heterojunction and offers the possibility of engineering the electronic characteristics of interfacial structures. Rectifying junctions with single and bipolar properties have been generated in Ag-TiO{sub 2} nanowire circuits incorporating asymmetrical and symmetrical interfacial structures, respectively. This fabrication technique should be applicable for the interconnection of other heterogeneous metal-oxide nanowire components and demonstrates that femtosecond laser irradiation enables interfacial engineering for electronic applications of integrated nanowire structures.

Plasmonic engineering of metal-oxide nanowire heterojunctions in integrated nanowire rectification units

Science.gov (United States)

Lin, Luchan; Zou, Guisheng; Liu, Lei; Duley, Walt W.; Zhou, Y. Norman

2016-05-01

We show that irradiation with femtosecond laser pulses can produce robust nanowire heterojunctions in coupled non-wetting metal-oxide Ag-TiO2 structures. Simulations indicate that joining arises from the effect of strong plasmonic localization in the region of the junction. Strong electric field effects occur in both Ag and TiO2 resulting in the modification of both surfaces and an increase in wettability of TiO2, facilitating the interconnection of Ag and TiO2 nanowires. Irradiation leads to the creation of a thin layer of highly defected TiO2 in the contact region between the Ag and TiO2 nanowires. The presence of this layer allows the formation of a heterojunction and offers the possibility of engineering the electronic characteristics of interfacial structures. Rectifying junctions with single and bipolar properties have been generated in Ag-TiO2 nanowire circuits incorporating asymmetrical and symmetrical interfacial structures, respectively. This fabrication technique should be applicable for the interconnection of other heterogeneous metal-oxide nanowire components and demonstrates that femtosecond laser irradiation enables interfacial engineering for electronic applications of integrated nanowire structures.

Scale-up of Carbon/Carbon Bipolar Plates

Energy Technology Data Exchange (ETDEWEB)

David P. Haack

2009-04-08

This project was focused upon developing a unique material technology for use in PEM fuel cell bipolar plates. The carbon/carbon composite material developed in this program is uniquely suited for use in fuel cell systems, as it is lightweight, highly conductive and corrosion resistant. The project further focused upon developing the manufacturing methodology to cost-effectively produce this material for use in commercial fuel cell systems. United Technology Fuel Cells Corp., a leading fuel cell developer was a subcontractor to the project was interested in the performance and low-cost potential of the material. The accomplishments of the program included the development and testing of a low-cost, fully molded, net-shape carbon-carbon bipolar plate. The process to cost-effectively manufacture these carbon-carbon bipolar plates was focused on extensively in this program. Key areas for cost-reduction that received attention in this program was net-shape molding of the detailed flow structures according to end-user design. Correlations between feature detail and process parameters were formed so that mold tooling could be accurately designed to meet a variety of flow field dimensions. A cost model was developed that predicted the cost of manufacture for the product in near-term volumes and long-term volumes (10+ million units per year). Because the roduct uses lowcost raw materials in quantities that are less than competitive tech, it was found that the cost of the product in high volume can be less than with other plate echnologies, and can meet the DOE goal of $4/kW for transportation applications. The excellent performance of the all-carbon plate in net shape was verified in fuel cell testing. Performance equivalent to much higher cost, fully machined graphite plates was found.

Bipolar soft connected, bipolar soft disconnected and bipolar soft compact spaces

Directory of Open Access Journals (Sweden)

Muhammad Shabir

2017-06-01

Full Text Available Bipolar soft topological spaces are mathematical expressions to estimate interpretation of data frameworks. Bipolar soft theory considers the core features of data granules. Bipolarity is important to distinguish between positive information which is guaranteed to be possible and negative information which is forbidden or surely false. Connectedness and compactness are the most important fundamental topological properties. These properties highlight the main features of topological spaces and distinguish one topology from another. Taking this into account, we explore the bipolar soft connectedness, bipolar soft disconnectedness and bipolar soft compactness properties for bipolar soft topological spaces. Moreover, we introduce the notion of bipolar soft disjoint sets, bipolar soft separation, and bipolar soft hereditary property and study on bipolar soft connected and disconnected spaces. By giving the detailed picture of bipolar soft connected and disconnected spaces we investigate bipolar soft compact spaces and derive some results related to this concept.

Bipolar characteristics of AlGaN/AlN/GaN/AlGaN double heterojunction structure with AlGaN as buffer layer

International Nuclear Information System (INIS)

Peng, Enchao; Wang, Xiaoliang; Xiao, Hongling; Wang, Cuimei; Yin, Haibo; Chen, Hong; Feng, Chun; Jiang, Lijuan; Hou, Xun; Wang, Zhanguo

2013-01-01

Highlights: •2DEG and 2DHG coexist in the AlGaN/AlN/GaN/AlGaN DH-structure. •The sheet densities of 2DEG and 2DHG vary with buffer Al content and GaN thickness. •The conditions for the disappearance of 2DHG are discussed. •Increasing buffer Al content provides better electron confinement. •Dislocation scattering is reduced in the DH-structure. -- Abstract: This is a theoretical study of AlGaN/AlN/GaN/AlGaN double heterojunction (DH) structure with AlGaN as buffer layer. Our calculation shows that as the buffer Al content increases, though two-dimensional electron gas (2DEG) sheet density decreases, the channel back-barrier caused by polarization-induced electric field in GaN provides better electron confinement. And under certain conditions the DH-structure shows bipolar characteristics, with an additional two-dimensional hole gas (2DHG) formed at GaN/AlGaN interface. The influence of the buffer Al content and GaN channel thickness on the 2DEG and 2DHG sheet densities are investigated, and the conditions for the disappearance of 2DHG are discussed. Also, the mobility inhibited by dislocation scattering is enhanced in DH-structure due to the enhancement of screening effect of the 2DEG

Garbage collector interface

OpenAIRE

Ive, Anders; Blomdell, Anders; Ekman, Torbjörn; Henriksson, Roger; Nilsson, Anders; Nilsson, Klas; Robertz, Sven

2002-01-01

The purpose of the presented garbage collector interface is to provide a universal interface for many different implementations of garbage collectors. This is to simplify the integration and exchange of garbage collectors, but also to support incremental, non-conservative, and thread safe implementations. Due to the complexity of the interface, it is aimed at code generators and preprocessors. Experiences from ongoing implementations indicate that the garbage collector interface successfully ...

A Generalized Theory Explains the Anomalous Suns–Voc Response of Si Heterojunction Solar Cells

KAUST Repository

Chavali, Raghu Vamsi Krishna

2016-11-30

Suns–Voc measurements exclude parasitic series resistance effects and are, therefore, frequently used to study the intrinsic potential of a given photovoltaic technology. However, when applied to a-Si/c-Si heterojunction (SHJ) solar cells, the Suns–Voc curves often feature a peculiar turnaround at high illumination intensities. Generally, this turn-around is attributed to extrinsic Schottky contacts that should disappear with process improvement. In this paper, we demonstrate that this voltage turnaround may be an intrinsic feature of SHJ solar cells, arising from the heterojunction (HJ), as well as its associated carrier-transport barriers, inherent to SHJ devices. We use numerical simulations to explore the full current–voltage (J–V) characteristics under different illumination and ambient temperature conditions. Using these characteristics, we establish the voltage and illumination-intensity bias, as well as temperature conditions necessary to observe the voltage turnaround in these cells. We validate our turnaround hypothesis using an extensive set of experiments on a high-efficiency SHJ solar cell and a molybdenum oxide (MoOx) based hole collector HJ solar cell. Our work consolidates Suns–Voc as a powerful characterization tool for extracting the cell parameters that limit efficiency in HJ devices.

Heterojunction Structures for Photon Detector Applications

Science.gov (United States)

2014-07-21

IR: Fourier-transform infrared FTO: Fluorine doped tin oxide G-R: generation-recombination HEIWIP: heterojunction interfacial workfunction internal...SECURITY CLASSIFICATION OF: The work presented here report findings in (1) infrared detectors based on p-GaAs/AlGaAs heterojunctions , (2) J and H...aggregate sensitized heterojunctions for solar cell and photon detection applications, (3) heterojunctions sensitized with quantum dots as low cost

Investigations on efficiencies of HT solar collectors for different flow rates and collector tilts

DEFF Research Database (Denmark)

Chen, Ziqian; Perers, Bengt; Furbo, Simon

2013-01-01

Two HT solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one solar collector is equipped with an ETFE foil between the abso......Two HT solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one solar collector is equipped with an ETFE foil between...... the absorber and the cover glass and the other is without ETFE foil. The efficiencies for the collectors are tested at different flow rates and tilt. On the basis of the measured efficiencies, the efficiencies for the collectors as functions of flow rates are obtained. The calculated efficiencies are in good...

Six-month open-label follow-up of risperidone long-acting injection use in pediatric bipolar disorder.

Science.gov (United States)

Boarati, Miguel A; Wang, Yuan-Pang; Ferreira-Maia, Ana Paula; Cavalcanti, Ana Rosa S; Fu-I, Lee

2013-01-01

Recent studies suggest that risperidone long-acting injection (RLAI) may be considered for controlling mood episodes in bipolar disorder patients who have relapsed due to medication nonadherence or failure to respond to standard therapies. Currently, no study has reported the usefulness of RLAI in youths with bipolar disorder. The aim of this study was to evaluate short-term effects of RLAI in the naturalistic treatment of early-onset bipolar disorder and its role in symptomatic remission and adherence to treatment. Nineteen early-onset bipolar disorder outpatients receiving RLAI were observed in a 6-month naturalistic study at the outpatient clinic of the Child and Adolescent Affective Disorders Program at the Institute of Psychiatry of the University of São Paulo, São Paulo, Brazil. All patients met DSM-IV criteria for bipolar disorder. Clinical response to RLAI was evaluated using the Children's Global Assessment Scale (CGAS) and Clinical Global Impressions scale (CGI) across 3 time periods: index time (T0), 8 weeks after (T1), and 24 weeks after (T2). These subjects were recruited from May 2008 to December 2009. Patients receiving RLAI presented considerable improvement in global functioning (CGAS: T0 = 20.6; T1 = 42.9; and T2 = 49.2) and clinical severity (CGI: T0 = 5.9; T1 = 3.9; and T2 = 3.4). Global CGI mean scores of clinical improvement were 2.2 at T1 and 2.4 at T2. There were no significant changes in laboratory measurements and weight throughout follow-up. RLAI was shown to be an alternative treatment for youths with bipolar disorder failing to respond to prior medication trials or with adherence problems. Further blind, randomized controlled studies are necessary to confirm these initial findings. Sistema Nacional de Informaçōes Sobre Ética em Pesquisa Envolvendo Seres Humanos-Commisão Nacional de Ética em Pesquisa identifier: CAAE 0709.0.015.000-06.

Bipolar radiofrequency ablation of benign thyroid nodules using a multiple overlapping shot technique in a 3-month follow-up.

Science.gov (United States)

Kohlhase, Konstantin David; Korkusuz, Yücel; Gröner, Daniel; Erbelding, Christian; Happel, Christian; Luboldt, Wolfgang; Grünwald, Frank

2016-08-01

Purpose The aim of this study was to evaluate the decrease of benign thyroid nodules after bipolar radiofrequency ablation (RFA) in a 3-month follow-up using a multiple overlapping shot technique ('MOST'). Methods A total of 18 patients with 20 symptomatic benign thyroid nodules (17 cold nodules, 3 hyperfunctioning nodules) were treated in one single session by bipolar RFA. Bipolar ablation was performed using MOST. The nodule volumes were measured prior to ablation and 3 months after the procedure using ultrasound. The population consisted of either solid (>80% solid tissue within the volume of interest), complex, or cystic nodules (nodule volume (ΔV), median 5.3 mL (range 0.13-43.1 mL), corresponding to a relative reduction in mean of 56 ± 17.9%. Median initial volume was 8 mL (range 0.48-62 mL); 3 months after ablation a median volume of 2.3 mL (range 0.3-32 mL) was measured. Nodule growth ≥50% occurred in 70% (14 nodules). At the follow-up no complications such as infections, persisting pain, nerve injuries or immunogen stimulation occurred. Patients with cold nodules (15) remained euthyroid, with hyperfunctioning nodules either euthyroid (2) or latent hypofunctional (1). Conclusion The use of bipolar RFA is an effective, safe and suitable thermoablative technique to treat benign thyroid nodules. Combined with the multiple overlapping shot technique it allows sufficient ablation.

Efficiency of liquid flat-plate solar energy collector with solar tracking system

Directory of Open Access Journals (Sweden)

Chekerovska Marija

2015-01-01

Full Text Available An extensive testing programme is performed on a solar collector experimental set-up, installed on a location in Shtip (Republic of Macedonia, latitude 41º 45’ and longitude 22º 12’, in order to investigate the effect of the sun tracking system implementation on the collector efficiency. The set-up consists of two flat plate solar collectors, one with a fixed surface tilted at 30о towards the South, and the other one equipped with dual-axis rotation system. The study includes development of a 3-D mathematical model of the collectors system and a numerical simulation programme, based on the computational fluid dynamics (CFD approach. The main aim of the mathematical modelling is to provide information on conduction, convection and radiation heat transfer, so as to simulate the heat transfer performances and the energy capture capabilities of the fixed and moving collectors in various operating modes. The feasibility of the proposed method was confirmed by experimental verification, showing significant increase of the daily energy capture by the moving collector, compared to the immobile collector unit. The comparative analysis demonstrates a good agreement between the experimental and numerically predicted results at different running conditions, which is a proof that the presented CFD modelling approach can be used for further investigations of different solar collectors configurations and flow schemes.

Mathematical modelling of unglazed solar collectors under extreme operating conditions

DEFF Research Database (Denmark)

Bunea, M.; Perers, Bengt; Eicher, S.

2015-01-01

average temperature levels at the evaporator. Simulation of these systems requires a collector model that can take into account operation at very low temperatures (below freezing) and under various weather conditions, particularly operation without solar irradiation.A solar collector mathematical model......Combined heat pumps and solar collectors got a renewed interest on the heating system market worldwide. Connected to the heat pump evaporator, unglazed solar collectors can considerably increase their efficiency, but they also raise the coefficient of performance of the heat pump with higher...... was found due to the condensation phenomenon and up to 40% due to frost under no solar irradiation. This work also points out the influence of the operating conditions on the collector's characteristics.Based on experiments carried out at a test facility, every heat flux on the absorber was separately...

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

The effect of fluorine in low thermal budget polysilicon emitters for SiGe heterojunction bipolar transistors

International Nuclear Information System (INIS)

Schiz, F.J.W.

1999-03-01

results are explained by the different evolution of defects in as-deposited α-Si and p-Si. The application of fluorine in low thermal budget polysilicon emitters is demonstrated ill a novel self-aligned SiGe heterojunction bipolar transistor concept which is implemented using selective and non-selective epitaxy. The process has the advantage of layer growth ill a single epitaxy step, no growth interfaces in the depletion regions, and oxide isolation as all intrinsic part of the device structure. The device electrical results demonstrate the feasibility of the transistor concept. A detailed analysis of leakage currents is performed and a correlation made with cross-section TEM micrographs. It is shown that E/C leakage is due to punch through at the perimeter of the transistor where the SiGe base is thinner. E/B is explained by the penetration of the E/B depletion region into the extrinsic at the perimeter of the emitter. By directing the extrinsic base implant into single crystal material at the perimeter of the base, both leakage mechanisms can be avoided. (author)

Radiation energy collector

Energy Technology Data Exchange (ETDEWEB)

Chao, Bei Tse; Rabl, A

1977-02-10

The invention deals with a concentrating solar collector. Collectors of this kind often have considerable natural convection losses which are due, among other facts, to the location of the energy absorber at the outlet with the heated surface of the absorber facing the inlet opening of the collector. According to the invention, the collector is designed in such manner that the absorber is located inside a space in such a way that the radiation emitted by the absorber is reflected back to the absorber with the aid of mirror surfaces. Various designs are described.

Solar collectors and heat pump: Market review and preliminary simulation results

International Nuclear Information System (INIS)

Tepe, Rainer; Roennelid, Mats

2002-01-01

Heating systems that combine solar collectors and a heat pump available on the market in Sweden have been studied. A majority of the systems found combine the solar collectors with a ground source heat pump. The technology for combining the collectors and the heat pump does however vary considerably. In the most simple systems, the collectors heat the return water from the heat pump, i.e. the collectors are used for raising the temperature in the boreholes for the heat pump. In the advanced systems, the solar heat is used for tap water, space heating and for raising the temperature of the heat pump's evaporator. There exist only very few comparative evaluations of the contributions from solar collectors in heat pump systems, and there is a need for finding the potential for this technique. In the present study, results are reported from preliminary simulations of solar collectors and ground source heat pumps installed in one-family houses. Simulations are made for two heating loads: 8,650 and 16,500 kWh/year resp., and a hot water load of 3,000 kWh/year. The study shows that: the temperature of the borehole decreases when solar collectors are not used (about 1.2 deg C in three years): 8 m 2 glazed solar collectors used for hot water production can reduce the electricity consumption with up to 13%, with best results in the house with low heating load: 50 m 2 unglazed solar collectors coupled to the evaporator or the borehole can give reductions of up to 14%, largest reduction in the house with high heating load, where the heat extraction from the borehole is large: the unglazed collectors have the highest economic potential, and can be cost effective for houses with high heating load: the simulations do not include a thorough system optimization, better results can be expected from continued optimization work

Low cost bare-plate solar air collector

Science.gov (United States)

Maag, W. L.; Wenzler, C. J.; Rom, F. E.; Vanarsdale, D. R.

1980-09-01

A low cost, bare plate solar collector for preheating ambient air was developed. This type of solar heating system would be applicable for preheating ventilation air for public buildings or other commercial and industrial ventilation requirements. Two prototype collectors were designed, fabricated and installed into an instrumented test system. Tests were conducted for a period of five months. Results of the tests showed consistent operating efficiencies of 60 percent or greater with air preheat temperature uses up to 20 degrees for one of the prototypes. The economic analyses indicated that this type of solar system was economically viable. For the materials of construction and the type of fabrication and installation perceived, costs for the bare plate solar collector are attainable. Applications for preheating ventilation air for schools were evaluated and judged to be economically viable.

Investigating the collector efficiency of silver nanofluids based direct absorption solar collectors

International Nuclear Information System (INIS)

Chen, Meijie; He, Yurong; Zhu, Jiaqi; Wen, Dongsheng

2016-01-01

Highlights: • An analysis coupled with Radiation transfer, Maxwell and Energy equation is developed. • Plasmonic Au and Ag nanofluids show better photo-thermal conversion properties. • Collector height and particle concentration exist optimum solutions for efficiency. - Abstract: A one-dimensional transient heat transfer analysis was carried out to analyze the effects of the Nanoparticle (NP) volume fraction, collector height, irradiation time, solar flux, and NP material on the collector efficiency. The numerical results were compared with the experimental results obtained by silver nanofluids to validate the model, and good agreement was obtained. The numerical results show that the collector efficiency increases as the collector height and NP volume fraction increase and then reaches a maximum value. An optimum collector height (∼10 mm) and particle concentration (∼0.03%) achieving a collector efficiency of 90% of the maximum efficiency can be obtained under the conditions used in the simulation. However, the collector efficiency decreases as the irradiation time increases owing to the increased heat loss. A high solar flux is desirable to maintain a high efficiency over a wide temperature range, which is beneficial for subsequent energy utilization. The modeling results also show silver and gold nanofluids obtain higher photothermal conversion efficiencies than the titanium dioxide nanofluid because their absorption spectra are similar to the solar radiation spectrum.

On the Influence of Collector Size on the Solar Chimneys Performance

Directory of Open Access Journals (Sweden)

Al-Azawiey Sundus S.

2017-01-01

Full Text Available Performance of solar chimney power plant system is highly influenced by the design geometries. The collector size is logically enhances the solar chimney performance, but the trend of enhancement is not yet investigated. In the present work, experimental and numerical investigations have been carried out to ascertain, in terms of qualitative and quantitative evaluation, the effect of the collector diameter. Daily thermal efficiency has been determined at four different collector diameter. Two different collector diameters, 3.0 and 6.0 m, have been investigated experimentally, and then scaled up, to 9.0 and 12.0 m, by numerical simulation using ANSYS-FLUENT®15 software. Results demonstrated that collector diameter has effectively influenced the system performance. Larger collector diameter imposed increase in the velocity, temperature and the daily average thermal efficiency of the system. From the experimental results, increasing the collector diameter from 3.0 to 6.0 m has increased the daily average thermal efficiency of the collector from 9.81 to 12.8. Simulation results at 800 W/m2 irradiation revealed that the velocity in the chimney have increased from 1.66 m/s at 3.0 m collector diameter to 2.34, 2.47 and 2.63 m/s for 6.0, 9.0 and 12.0 m collector diameters, respectively.

Bipolar charge transport in PCPDTBT-PCBM bulk-heterojunctions for photovoltaic applications

Energy Technology Data Exchange (ETDEWEB)

Morana, Mauro [Konarka Austria GmbH, 4040 Linz (Austria); Dipartimento di Ingegeria Elettrica ed Elettronica, Universita di Cagliari (Italy); Wegscheider, Matthias; Bonanni, Alberta [Johannes Kepler University, Institute of Solid State Physics, Linz (Austria); Kopidakis, Nikos; Shaheen, Sean [National Renewable Energy Laboratory, Golden, CO (United States); Scharber, Markus; Brabec, Christoph [Konarka Austria GmbH, 4040 Linz (Austria); Zhu, Zhengguo; Waller, David; Gaudiana, Russell [Konarka Technologies Inc., Lowell, MA (United States)

2008-06-24

An experimental study of the transport properties of a low-bandgap conjugated polymer giving high photovoltaic quantum efficiencies in the near infrared spectral region (E{sub g-opt}{proportional_to} 1.35 eV) is presented. Using a organic thin film transistor geometry, we demonstrate a relatively high in-plane hole mobility, up to 1.5. x 10{sup -2} cm{sup 2} V{sup -1} s{sup -1} and quantify the electron mobility at 3 x . 10{sup -5} cm{sup 2} V{sup -1} s{sup -1} on a SiO{sub 2} dielectric. In addition, singular contact behavior results in bipolar quasi-Ohmic injection both from low and high workfunction metals like LiF/Al and Au. X-ray investigations revealed a degree of interchain {pi}-stacking that is probably embedded in a disordered matrix. Disorder also manifests itself in a strong positive field dependence of the hole mobility from the electric field. In blends made with the electron acceptor methanofullerene [6,6]-phenyl C{sub 61} butyric acid methyl ester (PCBM), the transistor characteristics suggest a relatively unfavorable intermixing of the two components for the application to photovoltaic devices. We attribute this to a too fine dispersion of [C60]-PCBM in the polymer matrix, that is also confirmed by the quenching of the photoluminescence signal measured in PCPDTBT [C60]-PCBM films with various composition. We show that a higher degree of phase separation can be induced during the film formation by using 1,8-octanedithiol (ODT), which leads to a more efficient electron percolation in the [C60]-PCBM. In addition, the experimental results, in combination with those of solar cells seem to support the correlation between the blend morphology and charge recombination. We tentatively propose that the drift length, and similarly the electrical fill factor, can be limited by the recombination of holes with electrons trapped on isolated [C60]-PCBM clusters. Ionized and isolated [C60]-PCBM molecules can modify the local electric field in the solar cell by build-up

Tracking system for solar collectors

Science.gov (United States)

Butler, B.

1980-10-01

A tracking system is provided for pivotally mounted spaced-apart solar collectors. A pair of cables is connected to spaced-apart portions of each collector, and a driver displaces the cables, thereby causing the collectors to pivot about their mounting, so as to assume the desired orientation. The collectors may be of the cylindrical type as well as the flat-plate type. Rigid spar-like linkages may be substituted for the cables. Releasable attachments of the cables to the collectors is also described, as is a fine tuning mechanism for precisely aligning each individual collector.

Perceived parental rearing of bipolar offspring

NARCIS (Netherlands)

Reichart, C. G.; van der Ende, J.; Hillegers, M. H. J.; Wals, M.; Bongers, I. L.; Nolen, W. A.; Ormel, J.; Verhulst, F. C.

Objective: To explore the impact of growing up with a parent with a bipolar disorder. First, we compared parental rearing behavior perceived by young adult offspring of bipolar parents with parental rearing behavior perceived by same aged young adults from the general population. Secondly, we

A comparison of two cloudwater/fogwater collectors: The rotating arm collector and the caltech active strand cloudwater collector

Science.gov (United States)

Collett, Jeffrey L.; Daube, Bruce C.; Munger, J. William; Hoffmann, Michael R.

A side-by-side comparison of the Rotating Arm Collector (RAC) and the Caltech Active Strand Cloudwater Collector (CASCC) was conducted at an elevated coastal site near the eastern end of the Santa Barbara Channel in southern California. The CASCC was observed to collect cloudwater at rates of up to 8.5 ml min -1. The ratio of cloudwater collection rates was found to be close to the theoretical prediction of 4.2:1 (CASCC:RAC) over a wide range of liquid water contents (LWC). At low LWC, however, this ratio climbed rapidly, possibly reflecting a predominance of small droplets under these conditions, coupled with a greater collection efficiency of small droplets by the CASCC. Cloudwater samples collected by the RAC had significantly higher concentrations of Na +, Ca 2+, Mg 2+ and Cl - than those collected by the CASCC. These higher concentrations may be due to differences in the chemical composition of large vs small droplets. No significant differences were observed in concentrations of NO 3-, SO 42- or NH 4+ in samples collected by the two instruments.

Hybrid van der Waals p-n Heterojunctions based on SnO and 2D MoS2

KAUST Repository

Wang, Zhenwei

2016-08-30

A p-type oxide/2D hybrid van der Waals p-n heterojunction is demonstrated for the first time between SnO (tin monoxide) (the p-type oxide) and 2D MoS2 (molybdenum disulfide), showing an ideality factor of 2 and rectification ratio up to 10(4) . The reported heterojunction is gate-tunable with typical anti-ambipolar transfer characteristics. Surface potential mapping is performed and a current model for such a heterojunction is proposed.

PV-hybrid and thermoelectric collectors

Energy Technology Data Exchange (ETDEWEB)

Rockendorf, G.; Sillmann, R. [Institut fuer Solarenergieforschung GmbH, Emmerthal (Germany); Podlowski, L.; Litzenburger, B. [SolarWerk GmbH, Teltow (Germany)

1999-07-01

Two different principles of thermoelectric cogeneration solar collectors have been realized and investigated. Concerning the first principle, the thermoelectric collector (TEC) delivers electricity indirectly by first producing heat and subsequently generating electricity by means of a thermoelectric generator. Concerning the second principle, the photovoltaic-hybrid collector (PVHC) uses photovoltaic cells, which are cooled by a liquid heat-transfer medium. The characteristics of both collector types are described. Simulation modules have been developed and implemented in TRNSYS 14.1 (1994), in order to simulate their behaviour in typical domestic hot-water systems. The discussion of the results shows that the electric output of the PV-hybrid collector is significantly higher than that of the thermoelectric collector. (author)

Modeling Heat Flow In a Calorimeter Equipped With a Textured Solar Collector

Science.gov (United States)

Jaworske, Donald A.; Allen, Bradley J.

2001-01-01

Heat engines are being considered for generating electric power for minisatellite applications, particularly for those missions in high radiation threat orbits. To achieve this objective, solar energy must be collected and transported to the hot side of the heat engine. A solar collector is needed having the combined properties of high solar absorptance, low infrared emittance, and high thermal conductivity. To test candidate solar collector concepts, a simple calorimeter was designed, manufactured, and installed in a bench top vacuum chamber to measure heat flow. In addition, a finite element analysis model of the collector/calorimeter combination was made to model this heat flow. The model was tuned based on observations from the as-manufactured collector/calorimeter combination. In addition, the model was exercised to examine other collector concepts, properties, and scale up issues.

Mathematical Modeling of Dual Intake Transparent Transpired Solar Collector

Directory of Open Access Journals (Sweden)

Thomas Semenou

2015-01-01

Full Text Available Nowadays, in several types of commercial or institutional buildings, a significant rise of transpired solar collectors used to preheat the fresh air of the building can be observed. Nevertheless, when the air mass flow rate is low, the collector efficiency collapses and a large amount of energy remains unused. This paper presents a simple yet effective mathematical model of a transparent transpired solar collector (TTC with dual intake in order to remove stagnation problems in the plenum and ensure a better thermal efficiency and more heat recovery. A thermal model and a pressure loss model were developed. Then, the combined model was validated with experimental data from the Solar Rating and Certification Corporation (SRCC. The results show that the collector efficiency can be up to 70% and even 80% regardless of operating conditions. The temperature gain is able to reach 20°K when the solar irradiation is high.

Comparative familial aggregation of bipolar disorder in patients with bipolar I and bipolar II disorders.

Science.gov (United States)

Parker, Gordon B; Romano, Mia; Graham, Rebecca K; Ricciardi, Tahlia

2018-05-01

We sought to quantify the prevalence and differential prevalence of a bipolar disorder among family members of patients with a bipolar I or II disorder. The sample comprised 1165 bipolar and 1041 unipolar patients, with the former then sub-typed as having either a bipolar I or II condition. Family history data was obtained via an online self-report tool. Prevalence of a family member having a bipolar disorder (of either sub-type) was distinctive (36.8%). Patients with a bipolar I disorder reported a slightly higher family history (41.2%) compared to patients with a bipolar II disorder (36.3%), and with both significantly higher than the rate of bipolar disorder in family members of unipolar depressed patients (18.5%). Findings support the view that bipolar disorder is heritable. The comparable rates in the two bipolar sub-types support the positioning of bipolar II disorder as a valid condition with strong genetic underpinnings.

ROTATING STARS AND THE FORMATION OF BIPOLAR PLANETARY NEBULAE. II. TIDAL SPIN-UP

Energy Technology Data Exchange (ETDEWEB)

García-Segura, G. [Instituto de Astronomía, Universidad Nacional Autónoma de Mexico, Km. 103 Carr. Tijuana-Ensenada, 22860, Ensenada, B. C. (Mexico); Villaver, E. [Departamento de Física Teórica, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Manchado, A. [Instituto de Astrofísica de Canarias, Via Láctea s/n, E-38200 La Laguna, Tenerife (Spain); Langer, N. [Argelander-Institut für Astronomie, Universität Bonn, D-53121 Bonn (Germany); Yoon, S.-C., E-mail: ggs@astrosen.unam.mx [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul, 151-747 (Korea, Republic of)

2016-06-01

We present new binary stellar evolution models that include the effects of tidal forces, rotation, and magnetic torques with the goal of testing planetary nebulae (PNs) shaping via binary interaction. We explore whether tidal interaction with a companion can spin-up the asymptotic giant brach (AGB) envelope. To do so, we have selected binary systems with main-sequence masses of 2.5 M {sub ⊙} and 0.8 M {sub ⊙} and evolve them allowing initial separations of 5, 6, 7, and 8 au. The binary stellar evolution models have been computed all the way to the PNs formation phase or until Roche lobe overflow (RLOF) is reached, whatever happens first. We show that with initial separations of 7 and 8 au, the binary avoids entering into RLOF, and the AGB star reaches moderate rotational velocities at the surface (∼3.5 and ∼2 km s{sup −1}, respectively) during the inter-pulse phases, but after the thermal pulses it drops to a final rotational velocity of only ∼0.03 km s{sup −1}. For the closest binary separations explored, 5 and 6 au, the AGB star reaches rotational velocities of ∼6 and ∼4 km s{sup −1}, respectively, when the RLOF is initiated. We conclude that the detached binary models that avoid entering the RLOF phase during the AGB will not shape bipolar PNs, since the acquired angular momentum is lost via the wind during the last two thermal pulses. This study rules out tidal spin-up in non-contact binaries as a sufficient condition to form bipolar PNs.

Solar water disinfecting system using compound parabolic concentrating collector

Energy Technology Data Exchange (ETDEWEB)

El-Ghetany, H.H.; Saitoh, T.S. [Tohoku Univ., Sendai (Japan)

2000-05-31

Solar water disinfection is an alternative technology using solar radiation and thermal treatment to inactivate and destroy pathogenic microorganisms present in water. The Compound Parabolic Concentrating, (CPC) collector can be used as an efficient key component for solar disinfectanting system. Two types of the CPC collectors are studied, namely the transparent-tube and the Copper-tube CPC collector. It is found that after 30 minutes of exposing the water sample to solar radiation or heating it up to 65 degree C for a few minuets all the coliform bacterial present in the contaminated water sample were completely eliminated. In this article, the effect of water temperature on the disinfecting process was presented. Thermal and micro-biological measurements were also made to evaluate the system performance. (author)

Three-terminal heterojunction bipolar transistor solar cell for high-efficiency photovoltaic conversion.

Science.gov (United States)

Martí, A; Luque, A

2015-04-22

Here we propose, for the first time, a solar cell characterized by a semiconductor transistor structure (n/p/n or p/n/p) where the base-emitter junction is made of a high-bandgap semiconductor and the collector is made of a low-bandgap semiconductor. We calculate its detailed-balance efficiency limit and prove that it is the same one than that of a double-junction solar cell. The practical importance of this result relies on the simplicity of the structure that reduces the number of layers that are required to match the limiting efficiency of dual-junction solar cells without using tunnel junctions. The device naturally emerges as a three-terminal solar cell and can also be used as building block of multijunction solar cells with an increased number of junctions.

Bipolar polygenic loading and bipolar spectrum features in major depressive disorder

Science.gov (United States)

Wiste, Anna; Robinson, Elise B; Milaneschi, Yuri; Meier, Sandra; Ripke, Stephan; Clements, Caitlin C; Fitzmaurice, Garrett M; Rietschel, Marcella; Penninx, Brenda W; Smoller, Jordan W; Perlis, Roy H

2014-01-01

Objectives Family and genetic studies indicate overlapping liability for major depressive disorder and bipolar disorder. The purpose of this study was to determine whether this shared genetic liability influences clinical presentation. Methods A polygenic risk score for bipolar disorder, derived from a large genome-wide association meta-analysis, was generated for each subject of European–American ancestry (n = 1,274) in the Sequential Treatment Alternatives to Relieve Depression study (STAR*D) outpatient major depressive disorder cohort. A hypothesis-driven approach was used to test for association between bipolar disorder risk score and features of depression associated with bipolar disorder in the literature. Follow-up analyses were performed in two additional cohorts. Results A generalized linear mixed model including seven features hypothesized to be associated with bipolar spectrum illness was significantly associated with bipolar polygenic risk score [F = 2.07, degrees of freedom (df) = 7, p = 0.04). Features included early onset, suicide attempt, recurrent depression, atypical depression, subclinical mania, subclinical psychosis, and severity. Post-hoc univariate analyses demonstrated that the major contributors to this omnibus association were onset of illness at age ≤ 18 years [odds ratio (OR) = 1.2, p = 0.003], history of suicide attempt (OR = 1.21, p = 0.03), and presence of at least one manic symptom (OR = 1.16, p = 0.02). The maximal variance in these traits explained by polygenic score ranged from 0.8–1.1%. However, analyses in two replication cohorts testing a five feature model did not support this association. Conclusions Bipolar genetic loading appeared to be associated with bipolar-like presentation in major depressive disorder in the primary analysis. However, results are at most inconclusive because of lack of replication. Replication efforts are challenged by different ascertainment and assessment strategies in the different cohorts

High rate lithium/thionyl chloride bipolar battery development

Science.gov (United States)

Russell, P. G.; Goebel, F.

The lithium/thionyl chloride ( {Li}/{SOCl2}) electrochemistry is capable of providing high power and high specific power, especially under pulse discharge conditions, when cells containing thin components are arranged in a bipolar configuration. This paper describes recent work concerned with bipolar cell design, cathode evaluation, component manufacturing methods, and the assembly and testing of bipolar modules containing up to 150 cells for Sonobuoy application.

High rate lithium/thionyl chloride bipolar battery development

Energy Technology Data Exchange (ETDEWEB)

Russell, P.G. [Yardney Technical Products, Inc., Pawcatuck, CT (United States); Goebel, F. [Yardney Technical Products, Inc., Pawcatuck, CT (United States)

1995-04-01

The lithium/thionyl chloride (Li/SOCl{sub 2}) electrochemistry is capable of providing high power and high specific power, especially under pulse discharge conditions, when cells containing thin components are arranged in a bipolar configuration. This paper describes recent work concerned with bipolar cell design, cathode evaluation, component manufacturing methods, and the assembly and testing of bipolar modules containing up to 150 cells for Sonobuoy application. (orig.)

Characteristics of heterojunctions of amorphous LaAlO2.73 on Si

International Nuclear Information System (INIS)

Huang Yanhong; Zhao Kun; Lu Huibin; Jin Kuijuan; He Meng; Chen Zhenghao; Zhou Yueliang; Yang Guozhen

2006-01-01

High-quality heterojunctions consisting of n-type amorphous LaAlO 3- δ and p-type Si without Si interfacial layer were prepared using a thin film deposition system normally used for laser-molecular beam epitaxy. Good I-V rectifying property, ferroelectricity of interface enhancement and fast photovoltaic effect have been observed in the LaAlO 3- δ /Si p-n heterojunctions. We expect that the multifunctional properties of rectification, ferroelectricity and photovoltaic effect should open up new possibilities in device development and other applications

Rising hopes for vacuum tube collectors

Energy Technology Data Exchange (ETDEWEB)

Godolphin, D.

1982-06-01

The performance, feasibility and use of vacuum tube solar collectors for domestic hot water (DHW) systems are discussed. An introduction to the design of vacuum tube collectors is presented and comparisons are made with flat plate collectors in terms of effectiveness in DHW applications and cost. The use of vacuum tube collectors is well established for high temperature use such as process heat and absorption cooling applications; there is considerable debate concerning their use in DHW and these arguments are presented. It is pointed out that the accepted standardized comparison test (ASHRAE 93-77) is apparently biased towards the flat plate collectors in direct comparisons of collector efficiencies. Recent developments among manufacturers with regard to vacuum tube collectors and their thinking (pro and con) are discussed in some detail. Breakage and other problems are pointed out although advocates look ahead to lower costs, higher efficiencies, and broader markets (particularly in DHW). It is concluded by some that flat plate collector technology has reached its peak and that vacuum tube collectors will be very prominent in the future. (MJJ)

Understanding noise suppression in heterojunction field-effect transistors

International Nuclear Information System (INIS)

Green, F.

1996-01-01

Full text: The enhanced transport properties displayed by quantum-well-confined, two-dimensional, electron systems underpin the success of heterojunction, field-effect transistors. At cryogenic temperatures, these devices exhibit impressive mobilities and, as a result, high signal gain and low noise. Conventional wisdom has it that the same favourable conditions also hold for normal room-temperature operation. In that case, however, high mobilities are precluded by abundant electron-phonon scattering. Our recent study of nonequilibrium current noise shows that quantum confinement, not high mobility, is the principal source of noise in these devices; this opens up new and exciting opportunities in low-noise transistor design. As trends in millimetre-wave technology push frequencies beyond 100 GHz, it is essential to develop a genuine understanding of noise processes in heterojunction devices

Pediatric Bipolar Disorder versus Severe Mood Dysregulation: Risk for Manic Episodes on Follow-Up

Science.gov (United States)

Stringaris, Argyris; Baroni, Argelinda; Haimm, Caroline; Brotman, Melissa; Lowe, Catherine H.; Myers, Frances; Rustgi, Eileen; Wheeler, Wanda; Kayser, Reilly; Towbin, Kenneth; Leibenluft, Ellen

2010-01-01

Objective: An important question in pediatric bipolar research is whether marked nonepisodic irritability is a manifestation of bipolar disorder in youth. This study tests the hypothesis that youth with severe mood dysregulation (SMD), a category created for the purpose of studying children presenting with severe nonepisodic irritability, will be…

City sewer collectors biocorrosion

Science.gov (United States)

Ksiażek, Mariusz

2014-12-01

This paper presents the biocorrosion of city sewer collectors impregnated with special polymer sulphur binders, polymerized sulphur, which is applied as the industrial waste material. The city sewer collectors are settled with a colony of soil bacteria which have corrosive effects on its structure. Chemoautotrophic nitrifying bacteria utilize the residues of halites (carbamide) which migrate in the city sewer collectors, due to the damaged dampproofing of the roadway and produce nitrogen salts. Chemoorganotrophic bacteria utilize the traces of organic substrates and produce a number of organic acids (formic, acetic, propionic, citric, oxalic and other). The activity of microorganisms so enables the origination of primary and secondary salts which affect physical properties of concretes in city sewer collectors unfavourably.

Solar radiation on a catenary collector

Science.gov (United States)

Crutchik, M.; Appelbaum, J.

1992-01-01

A tent-shaped structure with a flexible photovoltaic blanket acting as a catenary collector is presented. The shadow cast by one side of the collector produces a shadow on the other side of the collector. This self-shading effect is analyzed. The direct beam, the diffuse, and the albedo radiation on the collector are determined. An example is given for the insolation on the collector operating on Viking Lander 1 (VL1).

Experimental and numerical investigation of a linear Fresnel solar collector with flat plate receiver

International Nuclear Information System (INIS)

Bellos, Evangelos; Mathioulakis, Emmanouil; Tzivanidis, Christos; Belessiotis, Vassilis; Antonopoulos, Kimon A.

2016-01-01

Highlights: • A linear Fresnel solar collector with flat plate receiver is investigated. • The collector is investigated experimentally in energetic and exergetic terms. • The developed numerical model is validated with the experimental results. • The operation with thermal oil is also examined with the developed model. • The final results prove satisfying performance for medium temperature levels. - Abstract: In this study a linear Fresnel solar collector with flat plate receiver is investigated experimentally and numerically with Solidworks Flow Simulation. The developed model combines optical, thermal and flow analysis; something innovative and demanding which leads to accurate results. The main objective of this study is to determine the thermal, the optical and the exergetic performance of this collector in various operating conditions. For these reasons, the developed model is validated with the respective experimental data and after this step, the solar collector model is examined parametrically for various fluid temperature levels and solar incident angles. The use of thermal oil is also analyzed with the simulation tool in order to examine the collector performance in medium temperature levels. The experiments are performed with water as working fluid and for low temperature levels up to 100 °C. The final results proved that this solar collector is able to produce about 8.5 kW useful heat in summer, 5.3 kW in spring and 2.9 kW in winter. Moreover, the operation of this collector with thermal oil can lead to satisfying results up to 250 °C.

High rate lithium-thionyl chloride bipolar battery development

Energy Technology Data Exchange (ETDEWEB)

Russell, P.G.; Goebel, F. [Yardney Technical Products, Inc., Pawcatuck, CT (United States)

1994-12-31

The lithium/thionyl chloride system is capable of providing both high power and high energy density when cells containing thin components are arranged in a bipolar configuration. Electrode current densities in excess of 300mA/cm{sup 2} are achieved during pulse discharge. The present work is concerned with bipolar cell design, cathode evaluation, component manufacturing methods, and the assembly and testing of bipolar modules containing up to 150 cells.

Colored solar collectors - Annual report 2006

Energy Technology Data Exchange (ETDEWEB)

Schueler, A.; Chambrier, E. De; Roecker, Ch.; Scartezzini, J.-L.

2007-12-15

The architectural integration of thermal solar collectors into buildings is often limited by their black color, and the visibility of tubes and corrugations of the absorber sheets. A certain freedom in color choice would be desirable, but the colored appearance should not cause an excessive degradation of the collector efficiency. Multilayered thin film interference filters on the collector glazing can produce a colored reflection, hiding the corrugated metal sheet, while transmitting the non-reflected radiation entirely to the absorber. These interference filters are designed and optimized by numerical simulation, and are manufactured by sol-gel dip-coating or magnetron sputtering. The novel colored glazed solar collectors will be ideally suited for architectural integration into buildings, e.g. as solar active glass facades. Due to the tunability of the refractive index, nanostructured materials such as SiO{sub 2}:TiO{sub 2} composites and porous SiO{sub 2} are very useful for application in multilayer interference stacks. Novel quaternary Mg-F-Si-O films exhibit a surprisingly low refractive index and are therefore promising candidates for highly transparent coatings on solar collector glazing. The nanostructure of these thin films is studied by transmission electron microscopy, while the optical constants are measured precisely by ellipsometry. For a convincing demonstration, sufficiently large samples of high quality are imperatively needed. The fabrication of nanocomposite SiO{sub 2}:TiO{sub 2} films has been demonstrated by sol-gel dip-coating of A4-sized glass panes. The produced coatings exhibit a colored reflection in combination with a high solar transmittance, a homogenous appearance, and are free of visible defects. Film hardening by UV exposure will result in speeding up the sol-gel process and saving energy, thereby reducing costs significantly. The infrastructure for UV-curing has been established. A UV C radiation source can now be attached to the

Solar collector manufacturing activity, 1990

International Nuclear Information System (INIS)

1992-01-01

The Solar Collector Manufacturing Activity 1990 report prepared by the Energy Information Administration (EIA) presents summary and detailed data provided by domestic manufacturers on shipments of solar thermal collectors and photovoltaic cells and modules. Summary data on solar thermal collector shipments are presented for the period 1974 through 1990. Summary data on photovoltaic cell and module shipments are presented for the period 1982 through 1990. Detailed information for solar thermal collectors and photovoltaic cells and modules are presented for 1990

Nickel hydrogen bipolar battery electrode design

Science.gov (United States)

Puglisi, V. J.; Russell, P.; Verrier, D.; Hall, A.

1985-01-01

The preferred approach of the NASA development effort in nickel hydrogen battery design utilizes a bipolar plate stacking arrangement to obtain the required voltage-capacity configuration. In a bipolar stack, component designs must take into account not only the typical design considerations such as voltage, capacity and gas management, but also conductivity to the bipolar (i.e., intercell) plate. The nickel and hydrogen electrode development specifically relevant to bipolar cell operation is discussed. Nickel oxide electrodes, having variable type grids and in thicknesses up to .085 inch are being fabricated and characterized to provide a data base. A selection will be made based upon a system level tradeoff. Negative (hydrpogen) electrodes are being screened to select a high performance electrode which can function as a bipolar electrode. Present nickel hydrogen negative electrodes are not capable of conducting current through their cross-section. An electrode was tested which exhibits low charge and discharge polarization voltages and at the same time is conductive. Test data is presented.

Analysis of the Nonlinear Characteristics of Microwave Power Heterojunction Bipolar Transistors and Optoelectronic Integrated Circuits.

Science.gov (United States)

Samelis, Apostolos

A physical basis for large-signal HBT modeling was established in terms of transit times using a Monte Carlo analysis of AlGaAs/GaAs and GaInP/GaAs designs. Static carriers located in the collector-subcollector interface were found to prohibit accurate evaluation of transit times from electron velocity profiles. These carriers also influence the bias dependence of device capacitances. Analytical parameter extraction techniques for DC, thermal and high frequency HBT parameters were developed and applied to HBT large-signal modeling. The "impedance block" conditioned optimization technique was introduced to facilitate parameter extraction. Physical analysis of HBTs by means of Volterra Series techniques showed that C_{bc } dominates nonlinear distortion in high gain amplifiers. Designs with that C_{bc }-V_{cb} characteristics i.e. p -n collector HBTs lead to more than 10 dB IP3 improvement over n-collector HBTs. Nonlinear current cancellation was found to improve intermodulation distortion. A Gummel -Poon-based HBT large-signal model incorporating self-heating effects was developed and applied to AlGaAs/GaAs HBTs. Maximum power drive was shown to occur using constant V _{be} father than I_ {b} bias. The device temperature of constant I_{b} biased HBTs decreases at increased rf-drive levels ensuring in this case safer device operation. A large-signal model incorporating "soft" -breakdown effects typical of InP/InGaAs HBTs was developed and found to model succesfully the power characteristics of OEICs built with them. The effective large-signal transimpedance of a cascode transimpedance preamplifier was evaluated using this model and found to degrade by 3dBOmega for a variation of P_{in} from -65 to -5 dBm. Self-bias of individual transistors was studied and found to be related to variations of the amplifier characteristics at higher rf-drive levels. The power characteristics of CE and CB AlGaAs/GaAs HBTs were investigated using an on -wafer source/load pull setup

Design package for concentrating solar collector panels

Energy Technology Data Exchange (ETDEWEB)

1978-08-01

Information used to evaluate the design of the Northrup concentrating collector is presented. Included are the system performance specifications, the applications manual, and the detailed design drawings of the collector. The Northrup concentrating solar collector is a water/glycol/working fluid type, dipped galvanized steel housing, transparent acrylic Fresnel lens cover, copper absorber tube, fiber glass insulation and weighs 98 pounds. The gross collector area is about 29.4/sup 2/ per collector. A collector assembly includes four collector units within a tracking mount array.

Economical judge possibility uses solar collectors to warm service water and heating

Directory of Open Access Journals (Sweden)

Lívia Bodonská

2006-09-01

Full Text Available The sun-heated water has been used from before fossil fuels started to determine the direction of our power consumption. This article is focused on the assessing of the use of solar energy as one of inexhaustible resources that has multiple uses, including hot water service systems. Heating is rendered through solar collectors that permit to transform solar energy to warm water. We divide solar collectors into various groups but in principle they are medium temperature collectors and low temperature collectors. The work is directed also on the solar collector market. In our case the market is just at its initial stage as this technology is little known and costs of collectors are rather high, compared to our conditions, on average, they may grow up to 100,000 Slovac crowns per a family house. Because it is the only investment and the costs of operation are minimum throughout the entire collectors lifetime, from the economic point of view, it is a rather advantageous investment. Solar collectors are used in heating and also in hot service water systems in family houses, where they permit to lower costs for the consumption of many kinds of energies. In the hot service water system, solar collectors permit to lower the consumption by almost 70 %. This way of using the solar energy is very prospective and in future it will be used in various sectors

Bipolar plates for PEM fuel cells

Science.gov (United States)

Middelman, E.; Kout, W.; Vogelaar, B.; Lenssen, J.; de Waal, E.

The bipolar plates are in weight and volume the major part of the PEM fuel cell stack, and are also a significant contributor to the stack costs. The bipolar plate is therefore a key component if power density has to increase and costs must come down. Three cell plate technologies are expected to reach targeted cost price levels, all having specific advantages and drawbacks. NedStack has developed a conductive composite materials and a production process for fuel cell plates (bipolar and mono-polar). The material has a high electric and thermal conductivity, and can be processed into bipolar plates by a proprietary molding process. Process cycle time has been reduced to less than 10 s, making the material and process suitable for economical mass production. Other development work to increase material efficiency resulted in thin bipolar plates with integrated cooling channels, and integrated seals, and in two-component bipolar plates. Total thickness of the bipolar plates is now less than 3 mm, and will be reduced to 2 mm in the near future. With these thin integrated plates it is possible to increase power density up to 2 kW/l and 2 kW/kg, while at the same time reducing cost by integrating other functions and less material use.

Electrical characterization of commercial NPN bipolar junction transistors under neutron and gamma irradiation

Directory of Open Access Journals (Sweden)

OO Myo Min

2014-01-01

Full Text Available Electronics components such as bipolar junction transistors, diodes, etc. which are used in deep space mission are required to be tolerant to extensive exposure to energetic neutrons and ionizing radiation. This paper examines neutron radiation with pneumatic transfer system of TRIGA Mark-II reactor at the Malaysian Nuclear Agency. The effects of the gamma radiation from Co-60 on silicon NPN bipolar junction transistors is also be examined. Analyses on irradiated transistors were performed in terms of the electrical characteristics such as current gain, collector current and base current. Experimental results showed that the current gain on the devices degraded significantly after neutron and gamma radiations. Neutron radiation can cause displacement damage in the bulk layer of the transistor structure and gamma radiation can induce ionizing damage in the oxide layer of emitter-base depletion layer. The current gain degradation is believed to be governed by the increasing recombination current in the base-emitter depletion region.

Highs and lows, ups and downs: Meteorology and mood in bipolar disorder.

Directory of Open Access Journals (Sweden)

Ben Bullock

Full Text Available Seasonal variation of manic and depressive symptoms is a controversial topic in bipolar disorder research. Several studies report seasonal patterns of hospital admissions for depression and mania and variation in symptoms that appear to follow a seasonal pattern, whereas others fail to report such patterns. Differences in research methodologies, data analysis strategies, and temporal resolution of data may partly explain the variation in findings between studies. The current study adds a novel perspective to the literature by investigating specific meteorological factors such as atmospheric pressure, hours of sunshine, relative humidity, and daily maximum and minimum temperatures as more proximal predictors of self-reported daily mood change in people diagnosed with bipolar disorder. The results showed that daily maximum temperature was the only meteorological variable to predict clinically-relevant mood change, with increases in temperature associated with greater odds of a transition into manic mood states. The mediating effects of sleep and activity were also investigated and suggest at least partial influence on the prospective relationship between maximum temperature and mood. Limitations include the small sample size and the fact that the number and valence of social interactions and exposure to natural light were not investigated as potentially important mediators of relationships between meteorological factors and mood. The current data make an important contribution to the literature, serving to clarify the specific meteorological factors that influence mood change in bipolar disorder. From a clinical perspective, greater understanding of seasonal patterns of symptoms in bipolar disorder will help mood episode prophylaxis in vulnerable individuals.

Turning collectors for solar radiation

Science.gov (United States)

Barak, Amitzur Z.

1976-01-01

A device is provided for turning a solar collector about the polar axis so that the collector is directed toward the sun as the sun tracks the sky each day. It includes two heat-expansive elements and a shadow plate. In the morning a first expansive element is heated, expands to turn the collector to face the sun, while the second expansive element is shaded by the plate. In the afternoon the second element is heated, expands to turn the collector to face the sun, while the first is shaded by the plate.

Effect of the work function and emission of the collector on the parameters of thermionic converters (TC)

International Nuclear Information System (INIS)

Kaibyshev, V.Z.

1986-01-01

In the optimal, relative to the temperature of the collector, state of modern thermionic converters (TC) the emission of the electrons from it has a substantial effect on the voltage drop in the gap. This paper preents an analysis of the boundary conditions at the collector of the TC. Calculations are presented which show that with a constant current the plasma parameters at the boundary with the collector are virtually independent of the emission from the collector right up to vanishing of the potential jump. The optimal regime with respect to temperatuer and work function of the collector is examined. The collector with a nonuniform work function is discussed

Coloured solar collectors. Phase II : from laboratory samples to collector prototypes. Final report

Energy Technology Data Exchange (ETDEWEB)

Schueler, A; Roecker, Ch; Chambrier, E de; Munari Probst, M

2007-07-01

This illustrated final report for the Swiss Federal Office of Energy (SFOE) deals with the second phase of a project concerning the architectural integration of glazed solar collectors into the facades of buildings for heat production. The factors that limit the integration of photovoltaic panels in facades are discussed. The authors state that, for a convincing demonstration, sufficiently large samples and high quality levels are needed. The sol-gel deposition of the multi-layered coatings on A4-sized glass panes demonstrated in the laboratory by EPFL-LESO are discussed. The coatings produced exhibit a coloured reflection in combination with a high solar transmittance, a homogenous appearance, and are free of visible defects. Film hardening by UV exposure is discussed: This should result in the speeding up of the sol-gel process and thus save energy, thereby significantly reducing costs. Collaboration with industry is discussed in which full-scale glass panes are to be coated with novel multiple layers. The novel glazing is to be integrated into first prototype collectors. The manufacturing and test processes for the prototypes manufactured are discussed in detail.

Modeling and Simulation of - and Silicon Germanium-Base Bipolar Transistors Operating at a Wide Range of Temperatures.

Science.gov (United States)

Shaheed, M. Reaz

1995-01-01

to provide consistently accurate values for base sheet resistance for both Si- and SiGe-base transistors over a wide range of temperatures. A model for plasma-induced bandgap narrowing suitable for implementation in a numerical simulator has been developed. The appropriate method of incorporating this model in a drift -diffusion solver is described. The importance of including this model for low temperature simulation is demonstrated. With these models in place, the enhanced simulator has been used for evaluating and designing the Si- and SiGe-base bipolar transistors. Silicon-germanium heterojunction bipolar transistors offer significant performance and cost advantages over conventional technologies in the production of integrated circuits for communications, computer and transportation applications. Their high frequency performance at low cost, will find widespread use in the currently exploding wireless communication market. However, the high performance SiGe-base transistors are prone to have a low common-emitter breakdown voltage. In this dissertation, a modification in the collector design is proposed for improving the breakdown voltage without sacrificing the high frequency performance. A comprehensive simulation study of p-n-p SiGe-base transistors has been performed. Different figures of merit such as drive current, current gain, cut -off frequency and Early voltage were compared between a graded germanium profile and an abrupt germanium profile. The differences in the performance level between the two profiles diminishes as the base width is scaled down.

Psychiatric and physical comorbidities and their impact on the course of bipolar disorder: A prospective, naturalistic 4-year follow-up study.

Science.gov (United States)

Amann, Benedikt L; Radua, Joaquim; Wunsch, Christian; König, Barbara; Simhandl, Christian

2017-05-01

The aim of the present study was to increase the available evidence on how physical and psychiatric comorbidities influence the long-term outcome in bipolar I and II disorder. We examined the prevalence of comorbid physical (metabolic, cardiovascular, thyroid, and neurological) diseases and psychiatric (neurotic, stress-related, somatoform, and personality) disorders and their impact on the risk of relapse in bipolar disorder. A total of 284 consecutively admitted patients with ICD-10 bipolar I (n=161) and II (n=123) disorder were followed up naturalistically over a period of 4 years. Globally, 22.0% patients had metabolic, 18.8% cardiovascular, 18.8% thyroid, and 7.6% neurological diseases; 15.5% had neurotic, stress-related, and somatoform disorders; 12.0% had personality disorders; and 52.9% had nicotine dependence. We did not find any effect of comorbid metabolic, cardiovascular or neurological diseases or psychiatric disorders on the relapse risk. However, the presence of thyroid diseases, and especially hypothyroidism, was associated with an increased risk of manic relapse in bipolar disorder I (thyroid disease: hazard ratio [HR]=2.7; P=.003; hypothyroidism: HR=3.7;, Pbipolar disorder with more manic episodes, and the importance of its detection and treatment. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Chemical vapor deposition growth of two-dimensional heterojunctions

Science.gov (United States)

Cui, Yu; Li, Bo; Li, JingBo; Wei, ZhongMing

2018-01-01

The properties of two-dimensional (2D) layered materials with atom-smooth surface and special interlayer van der Waals coupling are different from those of traditional materials. Due to the absence of dangling bonds from the clean surface of 2D layered materials, the lattice mismatch influences slightly on the growth of 2D heterojunctions, thus providing a flexible design strategy. 2D heterojunctions have attracted extensive attention because of their excellent performance in optoelectronics, spintronics, and valleytronics. The transfer method was utilized for the fabrication of 2D heterojunctions during the early stage of fundamental research on these materials. This method, however, has limited practical applications. Therefore, chemical vapor deposition (CVD) method was recently developed and applied for the preparation of 2D heterojunctions. The CVD method is a naturally down-top growth strategy that yields 2D heterojunctions with sharp interfaces. Moreover, this method effectively reduces the introduction of contaminants to the fabricated heterojunctions. Nevertheless, the CVD-growth method is sensitive to variations in growth conditions. In this review article, we attempt to provide a comprehensive overview of the influence of growth conditions on the fabrication of 2D heterojunctions through the direct CVD method. We believe that elucidating the effects of growth conditions on the CVD method is necessary to help control and improve the efficiency of the large-scale fabrication of 2D heterojunctions for future applications in integrated circuits.

Silicon nanowire array architecture for heterojunction electronics

International Nuclear Information System (INIS)

Solovan, M. M.; Brus, V. V.; Mostovyi, A. I.; Maryanchuk, P. D.; Orletskyi, I. G.; Kovaliuk, T. T.; Abashin, S. L.

2017-01-01

Photosensitive nanostructured heterojunctions n-TiN/p-Si were fabricated by means of titanium nitride thin films deposition (n-type conductivity) by the DC reactive magnetron sputtering onto nano structured single crystal substrates of p-type Si (100). The temperature dependencies of the height of the potential barrier and series resistance of the n-TiN/p-Si heterojunctions were investigated. The dominant current transport mechanisms through the heterojunctions under investigation were determined at forward and reverse bias. The heterojunctions under investigation generate open-circuit voltage V_o_c = 0.8 V, short-circuit current I_s_c = 3.72 mA/cm"2 and fill factor FF = 0.5 under illumination of 100 mW/cm"2.

Towards the optimization of the thermal–hydraulic performance of gyrotron collectors

Energy Technology Data Exchange (ETDEWEB)

Savoldi, Laura; Bertani, Cristina [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy); Cau, Francesca; Cismondi, Fabio [F4E, Barcelona (Spain); Gantenbein, Gerd; Illy, Stefan [Karlsruhe Institute of Technology (KIT), Institute for Pulsed Power and Microwave Technology (IHM), Kaiserstr. 12, 76131 Karlsruhe (Germany); Monni, Grazia [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy); Rozier, Yoann [Thales Electron Devices, 78141 Vélizy-Villacoublay (France); Zanino, Roberto, E-mail: roberto.zanino@polito.it [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy)

2015-11-15

Different configurations of water-cooled Cu collector for gyrotrons are investigated using the StarCCM + CFD code, aimed at optimizing its thermal–hydraulic (TH) performance. Although the current collectors show a good performance, the collector can be subjected to transient heat loads, due to the spent electron beam, of up to several tens of MW/m{sup 2}, and there is an interest to increase the gyrotron output power in the future. Furthermore, an optimized cooling will lead to improved reliability and lifetime of the collector. Starting from a hypervapotron (HV)-like collector, characterized by 100+ deep rectangular cavities with aspect ratio (AR) = 3, we present in the first part of the paper a single-cavity steady-state parametric analysis of the effect of AR on the heat exhaust capabilities. The investigation is then extended to other collector designs, including circumferential ribs and dimples, in order to assess the options for further improvements of the TH performance. The peak Cu temperature is computed by the code and its minimization is the target of the present optimization exercise. A self-consistent estimate of the heat transfer coefficient between collector and coolant is also obtained, which could be useful for fatigue and lifetime assessments. In the second part of the paper the most promising collector geometries identified in the first part are analyzed in the case of a transient heat load (vertical sweeping), first at the level of a single spatial period of the collector structure, then at the full-collector level. The results of the TH transient analysis are compared with both the results of the first part and with the transient purely thermal analysis of the full collector, showing for all geometries considered in this study a room for cooling efficiency improvement with respect to the HV-like design with AR = 3, at least in the operating conditions considered for this study (V ∼ 4 m/s, almost 100 °C sub-cooling).

Commissioning a Megawatt-class Gyrotron with Collector Potential Depression

Science.gov (United States)

Lohr, J.; Cengher, M.; Gorelov, Y. A.; Ponce, D.; Prater, R.

2013-10-01

A 110 GHz depressed collector gyrotron has been installed on the DIII-D tokamak. The commissioning process rapidly achieved operation at full parameters, 45 A and 94 kV total voltage, with 29 kV depression. Although short pulse, 2 ms, factory testing demonstrated 1.2 MW at 41% electrical efficiency, long pulse testing at DIII-D achieved only 33% efficiency at full power parameters, for pulse lengths up to 10 s. Maximum generated power was ~950 kW, considerably below the 1.2 MW target. During attempts to increase the power at 5 s pulse length, it was noted that the collector cooling water was boiling. This led to the discovery that 14 of the 160 cooling channels in the collector had been blocked by braze material during manufacture of the tube. The locations of blocked channels were identified using infrared imaging of the outside of the collector during rapid changes in the cooling water temperature. Despite these difficulties, the rf beam itself was of very high quality and the stray rf found calorimetrically in the Matching Optics Unit, which couples the Gaussian rf beam to the waveguide, was only 2% of the generated power, about half that of our previous best quality high power beam. Details of the power measurements and collector observations will be presented. Work supported by the US DOE under DE-FC02-04ER54698.

Characterization of ionizing radiation effects in MOS structures by study of bipolar operation; Caracterisation des effets induits par irradiations ionisantes dans des structures MOS a partir de leur fonctionnement en regime bipolaire

Energy Technology Data Exchange (ETDEWEB)

Bakhtiar, H. [Univ. Teknologi Malaysia, Dept. of Physics, Johor (Malaysia); Picard, C.; Brisset, C. [CEA Saclay, Lab. d' Electronique et de Technologie de l' Informatique, LETI, 91 - Gif-sur-Yvette (France); Bakhtiar, H.; Hoffmann, A.; Charles, J.P. [Metz Univ., LICM-CLOES-Supelec, 57 (France)

1999-07-01

This work presents an original method to characterize radiation effects of micronic transistors. The characterization includes a study of the transistor substrate-drain junction and current gain variation of the bipolar transistor (drain-substrate-source as emitter-base-collector) for different gate voltages. (author000.

Design of a solar-assisted drying system using the double-pass solar collector

International Nuclear Information System (INIS)

Sopian, K.; Daud, W.R.; Supranto; Othman, M.Y.; Yatim, B.

2000-01-01

A solar-assisted drying system that uses the double-pass solar collector with porous media in the second channel has been designed and constructed at the Solar Energy Research Park, Universiti Kebangsaan Malaysia. The drying system has a total of six double-pass solar collectors. Each collector has a length of 240 cm and a width of 120 cm. The upper channel depth is 3.5 cm and the lower channel depth is 10.5 cm. The lower channel is filled up with steel wool as the porous media. The solar collectors are arranged as 2 banks of 3 collectors each in series. Internal manifold are used to connect the collectors. An auxiliary heater source is installed to supply heat under unfavourable solar radiation conditions. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 80-90 0 C can be achieved at a solar radiation range of 800-900 W/m 3 , ambient temperature of 29 degree C and flow rate of O.20 kg/s. (Author)

Silicon nanowire array architecture for heterojunction electronics

Energy Technology Data Exchange (ETDEWEB)

Solovan, M. M., E-mail: m.solovan@chnu.edu.ua [Chernivtsi National University, Department of Electronics and Energy Engeneering (Ukraine); Brus, V. V. [Helmholtz-Zentrum Berlin fur Materialien und Energie GmbH, Institute for Silicon Photovoltaics (Germany); Mostovyi, A. I.; Maryanchuk, P. D.; Orletskyi, I. G.; Kovaliuk, T. T. [Chernivtsi National University, Department of Electronics and Energy Engeneering (Ukraine); Abashin, S. L. [National Aerospace University “Kharkiv Aviation Institute”, Department of Physics (Ukraine)

2017-04-15

Photosensitive nanostructured heterojunctions n-TiN/p-Si were fabricated by means of titanium nitride thin films deposition (n-type conductivity) by the DC reactive magnetron sputtering onto nano structured single crystal substrates of p-type Si (100). The temperature dependencies of the height of the potential barrier and series resistance of the n-TiN/p-Si heterojunctions were investigated. The dominant current transport mechanisms through the heterojunctions under investigation were determined at forward and reverse bias. The heterojunctions under investigation generate open-circuit voltage V{sub oc} = 0.8 V, short-circuit current I{sub sc} = 3.72 mA/cm{sup 2} and fill factor FF = 0.5 under illumination of 100 mW/cm{sup 2}.

On the Failure of Upscaling the Single-Collector Efficiency to the Transport of Colloids in an Array of Collectors

Science.gov (United States)

Messina, F.; Tosco, T.; Sethi, R.

2017-12-01

Colloidal transport and deposition in saturated porous media are phenomena of considerable importance in a large number of natural processes and engineering applications, such as the contaminant and microorganism propagation in aquifer systems, the development of innovative groundwater remediation technologies, air and water filtration, and many others. Therefore, a thorough understanding of particle filtration is essential for predicting the transport and fate of colloids in the subsurface environment. The removal efficiency of a filter is a key aspect for colloid transport in porous media. Several efforts were devoted to derive accurate correlations for the single collector efficiency, one of the key concept in the filtration theory. However, up scaling this parameter to the entire porous medium is still a challenge. The common up-scaling approach assumes the deposition to be independent of the transport history, which means that the collector efficiency is considered uniform along the porous medium. However, previous works showed that this approach is inadequate under unfavorable deposition conditions. This study demonstrates that it is not adequate even in the simplest case of favorable deposition. Computational Fluid Dynamics simulations were run for a simplify porous media geometry, composed of a vertical array of 50 identical spherical collectors. A combination of Lagrangian and Eulerian simulations were performed to analyze the particle transport under a broad range of parameters (i.e., particle size, particle density, water velocity). The results show the limits of the existing models to interpret the experimental data. In fact, the outcome evidenced that when particle deposition is not controlled by Brownian diffusion, non-exponential concentration profiles are retrieved, in contrast with the assumption of uniform efficiency. Moreover, when the deposition mechanisms of sedimentation and interception dominate, the efficiency of the first sphere of the

Broad Beam and Ion Microprobe Studies of Single-Event Upsets in High Speed 0.18micron Silicon Germanium Heterojunction Bipolar Transistors and Circuits

Science.gov (United States)

Reed, Robert A.; Marshall, Paul W.; Pickel, Jim; Carts, Martin A.; Irwin, TIm; Niu, Guofu; Cressler, John; Krithivasan, Ramkumar; Fritz, Karl; Riggs, Pam

2003-01-01

SiGe based technology is widely recognized for its tremendous potential to impact the high speed microelectronic industry, and therefore the space industry, by monolithic incorporation of low power complementary logic with extremely high speed SiGe Heterojunction Bipolar Transistor (HBT) logic. A variety of studies have examined the ionizing dose, displacement damage and single event characteristics, and are reported. Accessibility to SiGe through an increasing number of manufacturers adds to the importance of understanding its intrinsic radiation characteristics, and in particular the single event effect (SEE) characteristics of the high bandwidth HBT based circuits. IBM is now manufacturing in its 3rd generation of their commercial SiGe processes, and access is currently available to the first two generations (known as and 6HP) through the MOSIS shared mask services with anticipated future release of the latest (7HP) process. The 5 HP process is described and is characterized by a emitter spacing of 0.5 micron and a cutoff frequency ff of 50 GHz, whereas the fully scaled 7HP HBT employs a 0.18 micron emitter and has an fT of 120 GHz. Previous investigations have the examined SEE response of 5 HP HBT circuits through both circuit testing and modeling. Charge collection modeling studies in the 5 H P process have also been conducted, but to date no measurements have been reported of charge collection in any SiGe HBT structures. Nor have circuit models for charge collection been developed in any version other than the 5 HP HBT structure. Our investigation reports the first indications of both charge collection and circuit response in IBM s 7HP-based SiGe process. We compare broad beam heavy ion SEU test results in a fully function Pseudo-Random Number (PRN) sequence generator up to frequencies of 12 Gbps versus effective LET, and also report proton test results in the same circuit. In addition, we examine the charge collection characteristics of individual 7HP HBT

Bipolar Treatment: Are Bipolar I and Bipolar II Treated Differently?

Science.gov (United States)

... The diagnosis and management of bipolar I and bipolar II disorders: Clinical practice update. Mayo Clinic Proceedings. 2017;92:1532. Haynes PL, et al. Social rhythm therapies for mood disorders: An update. Current Psychiatry Reports. ...

Solar collector overheating protection

NARCIS (Netherlands)

Slaman, M.J.; Griessen, R.P.

Prismatic structures in a thermal solar collector are used as overheating protection. Such structures reflect incoming light efficiently back whenever less thermal power is extracted from the solar collector. Maximum thermal power is generated when the prismatic structure is surrounded by a

Climatic factors and bipolar affective disorder

DEFF Research Database (Denmark)

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

2008-01-01

In bipolar disorder, the factors provoking a new episode are unknown. As a seasonal variation has been noticed, it has been suggested that weather conditions may play a role. The aim of the study was to elucidate whether meteorological parameters influence the development of new bipolar phases....... 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...

Design package for concentrating solar collector panels

Science.gov (United States)

1978-01-01

Information used to evaluate the design of the Northrup concentrating collector is presented. Included are the system performance specifications, the applications manual, and the detailed design drawings of the collector. The collector is a water/glycol/working fluid type, with a dipped galvanized steel housing, transparent acrylic Fresnel lens cover, copper absorber tube, and fiber glass insulation. It weights 98 pounds. A collector assembly includes four collector units within a tracking mount array.

Simulation of a solar collector array consisting of two types of solar collectors, with and without convection barrier

DEFF Research Database (Denmark)

Bava, Federico; Furbo, Simon; Perers, Bengt

2015-01-01

The installed area of solar collectors in solar heating fields is rapidly increasing in Denmark. In this scenario even relatively small performance improvements may lead to a large increase in the overall energy production. Both collectors with and without polymer foil, functioning as convection...... barrier, can be found on the Danish market. Depending on the temperature level at which the two types of collectors operate, one can perform better than the other. This project aimed to study the behavior of a 14 solar collector row made of these two different kinds of collectors, in order to optimize...... the composition of the row. Actual solar collectors available on the Danish market (models HT-SA and HT-A 35-10 manufactured by ARCON Solar A/S) were used for this analysis. To perform the study, a simulation model in TRNSYS was developed based on the Danish solar collector field in Braedstrup. A parametric...

Performance of planar heterojunction perovskite solar cells under light concentration

Directory of Open Access Journals (Sweden)

Aaesha Alnuaimi

2016-11-01

Full Text Available In this work, we present 2D simulation of planar heterojunction perovskite solar cells under high concentration using physics-based TCAD. The performance of planar perovskite heterojunction solar cells is examined up to 1000 suns. We analyze the effect of HTM mobility and band structure, surface recombination velocities at interfaces and the effect of series resistance under concentrated light. The simulation results revealed that the low mobility of HTM material limits the improvement in power conversation efficiency of perovskite solar cells under concentration. In addition, large band offset at perovskite/HTM interface contributes to the high series resistance. Moreover, losses due to high surface recombination at interfaces and the high series resistance deteriorate significantly the performance of perovskite solar cells under concentration.

Numerical and experimental investigation on a new type of compound parabolic concentrator solar collector

International Nuclear Information System (INIS)

Zheng, Wandong; Yang, Lin; Zhang, Huan; You, Shijun; Zhu, Chunguang

2016-01-01

Highlights: • A serpentine compound parabolic concentrator solar collector is proposed. • A mathematical model for the new collector is developed and verified by experiments. • The thermal efficiency of the collector can be up to 60.5% during the experiments. • The effects of key parameters on the thermal performance are mathematically studied. - Abstract: In order to improve the thermal efficiency, reduce the heat losses and achieve high freezing resistance of the solar device for space heating in cold regions, a new type of serpentine compound parabolic concentrator solar collector is presented in this paper, which is a combination of a compound parabolic concentrator solar collector and a flat plate solar collector. A detailed mathematical model for the new collector based on the analysis of heat transfer is developed and then solved by the software tool Matlab. The numerical results are compared with the experimental data and the maximum deviation is 8.07%, which shows a good agreement with each other. The experimental results show that the thermal efficiency of the collector can be as high as 60.5%. The model is used to predict the thermal performance of the new collector. The effects of structure and operating parameters on the thermal performance are mathematically discussed. The numerical and experimental results show that the new collector is more suitable to provide low temperature hot water for space heating in cold regions and the mathematical model will be much helpful in the designing and optimizing of the solar collectors.

Four-collector flux sensor

International Nuclear Information System (INIS)

Wiegand, W.J. Jr.; Bullis, R.H.; Mongeon, R.J.

1980-01-01

A flowmeter based on ion drift techniques was developed for measuring the rate of flow of a fluid through a given cross-section. Ion collectors are positioned on each side of an immediately adjacent to ion source. When air flows axially through the region in which ions are produced and appropriate electric fields are maintained between the collectors, an electric current flows to each collector due to the net motion of the ions. The electric currents and voltages and other parameters which define the flow are combined in an electric circuit so that the flux of the fluid can be determined. (DN)

A distributed garbage collector for active objects

OpenAIRE

Puaut , Isabelle

1993-01-01

This paper introduces an algorithm that performs garbage collection in distributed systems of active objects (i.e., objects having their own threads of control). The proposed garbage collector is made of a set of local garbage collectors, one per node, loosely coupled to a global garbage collector. The novelties of the proposed garbage collector come from the fact that local garbage collectors need not be synchronized with each other for detecting garbage objects and that faulty communication...

Resistance change effect in SrTiO3/Si (001) isotype heterojunction

Science.gov (United States)

Huang, Xiushi; Gao, Zhaomeng; Li, Pei; Wang, Longfei; Liu, Xiansheng; Zhang, Weifeng; Guo, Haizhong

2018-02-01

Resistance switching has been observed in double and multi-layer structures of ferroelectric films. The higher switching ratio opens up a vast path for emerging ferroelectric semiconductor devices. An n-n+ isotype heterojunction has been fabricated by depositing an oxide SrTiO3 layer on a conventional n-type Si (001) substrate (SrTiO3/Si) by pulsed laser disposition. Rectification and resistive switching behaviors in the n-n+ SrTiO3/Si heterojunction were observed by a conductive atomic force microscopy, and the n-n+ SrTiO3/Si heterojunction exhibits excellent endurance and retention characteristics. The possible mechanism was proposed based on the band structure of the n-n+ SrTiO3/Si heterojunction, and the observed electrical behaviors could be attributed to the modulation effect of the electric field reversal on the width of accumulation and the depletion region, as well as the height of potential of the n-n+ junction formed at the STO/Si interface. Moreover, oxygen vacancies are also indicated to play a crucial role in causing insulator to semiconductor transition. These results open the way to potential application in future microelectronic devices based on perovskite oxide layers on conventional semiconductors.

Standardized performance tests of collectors of solar thermal energy: Prototype moderately concentrating grooved collectors

Science.gov (United States)

1976-01-01

Prototypes of moderately concentrating grooved collectors were tested with a solar simulator for varying inlet temperature, flux level, and incident angle. Collector performance is correlated in terms of inlet temperature and flux level.

Elevated left mid-frontal cortical activity prospectively predicts conversion to bipolar I disorder

Science.gov (United States)

Nusslock, Robin; Harmon-Jones, Eddie; Alloy, Lauren B.; Urosevic, Snezana; Goldstein, Kim; Abramson, Lyn Y.

2013-01-01

Bipolar disorder is characterized by a hypersensitivity to reward-relevant cues and a propensity to experience an excessive increase in approach-related affect, which may be reflected in hypo/manic symptoms. The present study examined the relationship between relative left-frontal electroencephalographic (EEG) activity, a proposed neurophysiological index of approach-system sensitivity and approach/reward-related affect, and bipolar course and state-related variables. Fifty-eight individuals with cyclothymia or bipolar II disorder and 59 healthy control participants with no affective psychopathology completed resting EEG recordings. Alpha power was obtained and asymmetry indices computed for homologous electrodes. Bipolar spectrum participants were classified as being in a major/minor depressive episode, a hypomanic episode, or a euthymic/remitted state at EEG recording. Participants were then followed prospectively for an average 4.7 year follow-up period with diagnostic interview assessments every four-months. Sixteen bipolar spectrum participants converted to bipolar I disorder during follow-up. Consistent with hypotheses, elevated relative left-frontal EEG activity at baseline 1) prospectively predicted a greater likelihood of converting from cyclothymia or bipolar II disorder to bipolar I disorder over the 4.7 year follow-up period, 2) was associated with an earlier age-of-onset of first bipolar spectrum episode, and 3) was significantly elevated in bipolar spectrum individuals in a hypomanic episode at EEG recording. This is the first study to identify a neurophysiological marker that prospectively predicts conversion to bipolar I disorder. The fact that unipolar depression is characterized by decreased relative left-frontal EEG activity suggests that unipolar depression and vulnerability to hypo/mania may be characterized by different profiles of frontal EEG asymmetry. PMID:22775582

Photovoltaic effects of Si-CdSe n-n heterojunctions

International Nuclear Information System (INIS)

Chung, C.C.; Kim, W.T.

1979-01-01

Si-CdSe n-n heterojunction have been prepared by growing CdSe thin film on Si(111) surface with vacuum deposition method. The sign of photovoltage of this heterojunction was reversed at 1.67eV. The energy band profile of this heterojunction was deduced from its electrical and optical properties. This lattice mismatching abrupt heterojunction had a discontinuous energy band profile with the discontinuity of 0.87eV at the conduction band, of 0.27eV at the valance band. (author)

New collectors from all over the world

Energy Technology Data Exchange (ETDEWEB)

Augsten, Eva

2008-07-01

Flat-plate collectors are fashionable, even among customers in Shanghai, although China is considered the land of evacuated tubes. Elsewhere, fashion is also a consideration, which partly explains the switch from fin collectors to full-surface collectors. Sun and Wind Energy has put together a list of new collectors from various countries. (orig.)

THERMAL PERFORMANCE OF FLAT PLATE SOLAR COLLECTOR

Directory of Open Access Journals (Sweden)

TABET I.

2017-06-01

Full Text Available In this paper, a theoretical and experimental studyof flat platesolar water collector with reflectors.A mathematical model based on energy balance equations saw the thermal behavior of the collector is investigated. The experimental test was made at the unit research applies in renewable energy (URAER located in southern Algeria.An increase of 23% for solar radiation incident on the collector surface with the addition of the planers reflectors in the day of May, this increase causes an improvement of the performance of the collector,the fluid temperature increases with an average of 5%. Thetests conducted on the flat plate solar water collector in open circuit enabled the determination of thermal performance of the collector by estimating the daily output The thermal efficiency of the collector ranges from 1% -63% during the day, a mean value of 36%obtained.

Analysis and validation of a quasi-dynamic model for a solar collector field with flat plate collectors and parabolic trough collectors in series for district heating

DEFF Research Database (Denmark)

Tian, Zhiyong; Perers, Bengt; Furbo, Simon

2018-01-01

performance of the hybrid solar district heating plants is also presented. The measured and simulated results show that the integration of parabolic trough collectors in solar district heating plants can guarantee that the system produces hot water with relatively constant outlet temperature. The daily energy......A quasi-dynamic TRNSYS simulation model for a solar collector field with flat plate collectors and parabolic trough collectors in series was described and validated. A simplified method was implemented in TRNSYS in order to carry out long-term energy production analyses of the whole solar heating...... plant. The advantages of the model include faster computation with fewer resources, flexibility of different collector types in solar heating plant configuration and satisfactory accuracy in both dynamic and long-term analyses. In situ measurements were taken from a pilot solar heating plant with 5960 m...

Exergy analysis of photovoltaic solar collector

International Nuclear Information System (INIS)

Sopian, K.; Othman, M.Y.Hj.

1998-01-01

The exergy analysis (availability or second law analysis) is applied to the photovoltaic thermal solar collector. Photovoltaic thermal collector is a special type of solar collector where electricity and heat are produced simultaneously. The electricity produced from the photovoltaic thermal collector is all converted into useful work. The available quantity of the heat collected can readily be determined by taking into account both the quantity (heat quantity) and quality ( a function of temperature) of the thermal energy. Therefore, using the concept of exergy allows heat produced from the thermal collector and the electricity generated from the photovoltaic cells to be compared or to be evaluated on the basis of a common measure such as the effectiveness on solar energy collection or the total amount of available energy. In this paper, the effectiveness of solar energy collection is called combined photovoltaic thermal exergy efficiency. An experimental setup of a double pas photovoltaic thermal solar collector has been deigned, fabricated and tested. (author)

A van der Waals pn heterojunction with organic/inorganic semiconductors

International Nuclear Information System (INIS)

He, Daowei; Yang, Ziyi; Wu, Bing; Xu, Bingchen; Zhang, Yuhan; Li, Yun; Shi, Yi; Wang, Xinran; Pan, Yiming; Wang, Baigeng; Nan, Haiyan; Luo, Xiaoguang; Ni, Zhenhua; Gu, Shuai; Zhu, Jia; Chai, Yang

2015-01-01

van der Waals (vdW) heterojunctions formed by two-dimensional (2D) materials have attracted tremendous attention due to their excellent electrical/optical properties and device applications. However, current 2D heterojunctions are largely limited to atomic crystals, and hybrid organic/inorganic structures are rarely explored. Here, we fabricate the hybrid 2D heterostructures with p-type dioctylbenzothienobenzothiophene (C 8 -BTBT) and n-type MoS 2 . We find that few-layer C 8 -BTBT molecular crystals can be grown on monolayer MoS 2 by vdW epitaxy, with pristine interface and controllable thickness down to monolayer. The operation of the C 8 -BTBT/MoS 2 vertical heterojunction devices is highly tunable by bias and gate voltages between three different regimes: interfacial recombination, tunneling, and blocking. The pn junction shows diode-like behavior with rectifying ratio up to 10 5 at the room temperature. Our devices also exhibit photovoltaic responses with a power conversion efficiency of 0.31% and a photoresponsivity of 22 mA/W. With wide material combinations, such hybrid 2D structures will offer possibilities for opto-electronic devices that are not possible from individual constituents

A van der Waals pn heterojunction with organic/inorganic semiconductors

Science.gov (United States)

He, Daowei; Pan, Yiming; Nan, Haiyan; Gu, Shuai; Yang, Ziyi; Wu, Bing; Luo, Xiaoguang; Xu, Bingchen; Zhang, Yuhan; Li, Yun; Ni, Zhenhua; Wang, Baigeng; Zhu, Jia; Chai, Yang; Shi, Yi; Wang, Xinran

2015-11-01

van der Waals (vdW) heterojunctions formed by two-dimensional (2D) materials have attracted tremendous attention due to their excellent electrical/optical properties and device applications. However, current 2D heterojunctions are largely limited to atomic crystals, and hybrid organic/inorganic structures are rarely explored. Here, we fabricate the hybrid 2D heterostructures with p-type dioctylbenzothienobenzothiophene (C8-BTBT) and n-type MoS2. We find that few-layer C8-BTBT molecular crystals can be grown on monolayer MoS2 by vdW epitaxy, with pristine interface and controllable thickness down to monolayer. The operation of the C8-BTBT/MoS2 vertical heterojunction devices is highly tunable by bias and gate voltages between three different regimes: interfacial recombination, tunneling, and blocking. The pn junction shows diode-like behavior with rectifying ratio up to 105 at the room temperature. Our devices also exhibit photovoltaic responses with a power conversion efficiency of 0.31% and a photoresponsivity of 22 mA/W. With wide material combinations, such hybrid 2D structures will offer possibilities for opto-electronic devices that are not possible from individual constituents.

A van der Waals pn heterojunction with organic/inorganic semiconductors

Energy Technology Data Exchange (ETDEWEB)

He, Daowei; Yang, Ziyi; Wu, Bing; Xu, Bingchen; Zhang, Yuhan; Li, Yun; Shi, Yi, E-mail: yshi@nju.edu.cn, E-mail: xrwang@nju.edu.cn; Wang, Xinran, E-mail: yshi@nju.edu.cn, E-mail: xrwang@nju.edu.cn [National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Pan, Yiming; Wang, Baigeng [National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093 (China); Nan, Haiyan; Luo, Xiaoguang; Ni, Zhenhua [Department of Physics, Southeast University, Nanjing 211189 (China); Gu, Shuai; Zhu, Jia [College of Engineering and Applied Science, Nanjing University, Nanjing 210093 (China); Chai, Yang [Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)

2015-11-02

van der Waals (vdW) heterojunctions formed by two-dimensional (2D) materials have attracted tremendous attention due to their excellent electrical/optical properties and device applications. However, current 2D heterojunctions are largely limited to atomic crystals, and hybrid organic/inorganic structures are rarely explored. Here, we fabricate the hybrid 2D heterostructures with p-type dioctylbenzothienobenzothiophene (C{sub 8}-BTBT) and n-type MoS{sub 2}. We find that few-layer C{sub 8}-BTBT molecular crystals can be grown on monolayer MoS{sub 2} by vdW epitaxy, with pristine interface and controllable thickness down to monolayer. The operation of the C{sub 8}-BTBT/MoS{sub 2} vertical heterojunction devices is highly tunable by bias and gate voltages between three different regimes: interfacial recombination, tunneling, and blocking. The pn junction shows diode-like behavior with rectifying ratio up to 10{sup 5} at the room temperature. Our devices also exhibit photovoltaic responses with a power conversion efficiency of 0.31% and a photoresponsivity of 22 mA/W. With wide material combinations, such hybrid 2D structures will offer possibilities for opto-electronic devices that are not possible from individual constituents.

Electronic structure of defects in semiconductor heterojunctions

International Nuclear Information System (INIS)

Haussy, Bernard; Ganghoffer, Jean Francois

2002-01-01

Full text.heterojunctions and semiconductors and superlattices are well known and well used by people interested in optoelectronics communications. Components based on the use of heterojunctions are interesting for confinement of light and increase of quantum efficiency. An heterojunction is the contact zone between two different semiconductors, for example GaAs and Ga 1-x Al x As. Superlattices are a succession of heterojunctions (up to 10 or 20). These systems have been the subjects of many experiments ao analyse the contact between semiconductors. They also have been theoretically studied by different types of approach. The main result of those studies is the prediciton of band discontinuities. Defects in heterojunctions are real traps for charge carriers; they can affect the efficiency of the component decreasing the currents and the fluxes in it. the knowledge of their electronic structure is important, a great density of defects deeply modifies the electronic structure of the whole material creating real new bands of energy in the band structure of the component. in the first part of this work, we will describe the heterostructure and the defect in terms of quantum wells and discrete levels. This approach allows us to show the role of the width of the quantum well describing the structure but induces specific behaviours due to the one dimensional modelling. Then a perturbative treatment is proposed using the Green's functions formalism. We build atomic chains with different types of atoms featuring the heterostructure and the defect. Densities of states of a structure with a defect and levels associated to the defect are obtained. Results are comparable with the free electrons work, but the modelling do not induce problems due to a one dimensional approach. To extend our modelling, a three dimensions approach, based on a cavity model, is investigated. The influence of the defect, - of hydrogenoid type - introduced in the structure, is described by a cavity

Biological sample collector

Science.gov (United States)

Murphy, Gloria A [French Camp, CA

2010-09-07

A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

High mobility and high concentration Type-III heterojunction FET

Science.gov (United States)

Tsu, R.; Fiddy, M. A.; Her, T.

2018-02-01

The PN junction was introduced in transistors by doping, resulting in high losses due to Coulomb scattering from the dopants. The MOSFET introduced carriers in the form of electrons and holes with an applied bias to the oxide barrier, resulting in carrier transfer without doping. This avoids high scattering losses and dominates the IC industries. With heterojunctions having valence-band maxima near and even above the conduction-band minimum in the formation of Type-III superlattices, very useful devices, introduced by Tsu, Sai-Halacz, and Esaki, soon followed. If the layer thicknesses are more than the carrier mean-free-path, incoherent scattering results in the formation of carrier transfer via diffusion instead of opening up new energy gaps. The exploitation of carriers without scattering represents a new and significant opportunity in what we call a Broken Gap Heterojunction FET.

Heterojunctions formed by annealing of GaSe and InSe layered crystals in zinc vapor

Directory of Open Access Journals (Sweden)

Kudrynskyi Z. R.

2012-12-01

Full Text Available The article presents a method of creating heterojunc¬tions based on semiconductors with different lattice types. Substrates manufactured from GaSe and InSe layered crystals were annealed in Zn vapor. This way, n-ZnSe–p-GaSe and n-ZnSe–p-InSe heterojunctions were obtained. The obtained heterojunctions are photo¬sensitive in near and infrared spectral regions. This method opens up greate possibilities of producing heterostructures with a desired sensitivity band.

Co-occurrence of Marfan syndrome and bipolar disorder: A fifteen year follow up.

Science.gov (United States)

Jha, Vijendra Nath; Kumar, Manoj; Tarwani, Jatin

2016-12-01

Marfan syndrome, a chromosomal disorder, has been commonly associated with schizophrenia but no association with Bipolar affective disorder has been reported in the scientific literature. This case depicts the occurrence of Bipolar affective disorder in a previously undiagnosed case of Marfan syndrome. In this case patient had all manic episodes without any depressive or schizophrenia-like episodes, suggesting a diagnostic stability over a long period of over fifteen years. Studies and research are needed in this regard to look for any possible potential association between the two illnesses. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of an industrialized space-frame system for the support of medium to large solar collector arrays

Energy Technology Data Exchange (ETDEWEB)

1982-11-01

A low-cost industrialized space-frame system suitable for the economical support of medium to large solar collector arrays was designed following a study of building types, collector interface conditions, structural design requirements, and market and procurement factors. The system consists of a series of welded truss modular sections which may be bolted together in the field to create a support structure with a span capability up to 25 m, thus minimizing expensive structural beams and roof penetrations. Collectors can be readily attached to top and bottom channels. The system meets all current government specifications for collector support. A full-size prototype was built to prove the concept and identify any fabrication and on-site assembly problems. Collectors were attached to test collector interface conditions, and a manufacturing strategy developed. 24 figs., 3 tabs.

Is bipolar always bipolar? Understanding the controversy on bipolar disorder in children

Science.gov (United States)

Grimmer, Yvonne; Hohmann, Sarah

2014-01-01

Dramatically increasing prevalence rates of bipolar disorder in children and adolescents in the United States have provoked controversy regarding the boundaries of manic symptoms in child and adolescent psychiatry. The serious impact of this ongoing debate on the treatment of affected children is reflected in the concomitant increase in prescription rates for antipsychotic medication. A key question in the debate is whether this increase in bipolar disorder in children and adolescents is based on a better detection of early-onset bipolar disorder—which can present differently in children and adolescents—or whether it is caused by an incorrect assignment of symptoms which overlap with other widely known disorders. So far, most findings suggest that the suspected symptoms, in particular chronic, non-episodic irritability (a mood symptom presenting with easy annoyance, temper tantrums and anger) do not constitute a developmental presentation of childhood bipolar disorder. Additional research based on prospective, longitudinal studies is needed to further clarify the developmental trajectories of bipolar disorder and the diagnostic status of chronic, non-episodic irritability. PMID:25580265

Single-stage depressed collectors for gyrotrons

International Nuclear Information System (INIS)

Piosczyk, B.; Iatrou, C.T.; Dammertz, G.; Thumm, M.; Univ. Karlsruhe

1996-01-01

Two 140 GHz gyrotrons with a single-step depressed collector have been operated. The different position of the isolating collector gap in the stray magnetic field causes the electron motion in the retarding region to be in one case adiabatic and in the other case nonadiabatic. The kind of motion within the retarding field influences strongly the behavior of the gyrotron with a depressed collector. In the case of nonadiabatic motion a significant amount of transverse momentum is given to the electrons reflected at the collector potential. This causes the reflected electrons to be trapped between the magnetic mirror and the collector. The electrons escape from the trap by diffusion across the magnetic field to the body of the tube thus contributing to the body current. Despite the high body current there is no observable influence of the collector voltage on the RF output power. In the case of adiabatic motion the reflected electrons do not gain a sufficient amount of transverse momentum to be trapped by the magnetic mirror. They pass the cavity toward the gun and they are trapped between the negative gun potential and the collector. The interaction with the RF field by electrons traveling through the cavity enhances the diffusion in the velocity space thus enabling the trapped electrons to overcome the potential barrier and escape toward the collector. Therefore the body current stays at low values since in this case the reflected electrons do not contribute to it. However, at higher collector voltages a reduction of RF power occurred and some noise in the electron beam was observed. The main motivation for the development of gyrotrons in the frequency range above 100 GHz with power levels in excess of several hundreds kW per tube, is the application in magnetic fusion devices for plasma heating and for electron current drive

Depleted Nanocrystal-Oxide Heterojunctions for High-Sensitivity Infrared Detection

Science.gov (United States)

2015-08-28

Approved for Public Release; Distribution Unlimited Final Report: 4.3 Electronic Sensing - Depleted Nanocrystal- Oxide Heterojunctions for High...reviewed journals: Final Report: 4.3 Electronic Sensing - Depleted Nanocrystal- Oxide Heterojunctions for High-Sensitivity Infrared Detection Report Title...PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: 1 1 Final Progress Report Project title: Depleted Nanocrystal- Oxide Heterojunctions for High

ANALYSIS AND MODELING OF SOLAR EVAPORATOR-COLLECTOR

Directory of Open Access Journals (Sweden)

Zakaria Mohd. Amin

2015-11-01

Full Text Available Solar energy is considered a sustainable resource that poses little to no harmful effects on the environment. The performance of a solar system depends to a great extent on the collector used for the conversion of solar radiant energy to thermal energy. A solar evaporator-collector (SEC is basically an unglazed flat plate collector where refrigerants, such as R134a is used as the working fluid. As the operating temperature of the SEC is very low, it utilizes both solar irradiation and ambient energy leading to a much higher efficiency than the conventional collectors. This capability of SECs to utilize ambient energy also enables the system to operate at night. This type of collector can be locally made and is relatively much cheaper than the conventional collector.   At the National University of Singapore, the evaporator-collector was integrated to a heat pump and the performance was investigated for several thermal applications: (i water heating, (ii drying and (iii desalination. A 2-dimensional transient mathematical model of this system was developed and validated by experimental data. The present study provides a comprehensive study of performance. KEYWORDS: heat pump; evaporator-collector.

Performance of an absorbing concentrating solar collectors

International Nuclear Information System (INIS)

Imadojemu, H.

1990-01-01

This paper reports on a comparison of the efficiency of an absorbing fluid parabolic trough concentrating solar collector and a traditional concentrating collector that was made. In the absorbing fluid collector, black liquid flows through a glass tube absorber while the same black liquid flows through a selective black coated copper tube absorber while the same black fluid flows through a selective black coated copper tube absorber in the traditional collector. After a careful study of the properties of available black liquids, a mixture of water and black ink was chosen as the black absorbing medium or transfer fluid. In the black liquid glass collector there is a slightly improved efficiency based on beam radiation as a result of the direct absorption process and an increase in the effective transmittance absorptance. At worst the efficiency of this collector equals that of the traditional concentrating collector when the efficiency is based on total radiation. The collector's reflecting surfaces were made of aluminum sheet, parabolic line focus and with cylindrical receivers. The ease of manufacture and reduced cost per unit energy collected, in addition to the clean and pollution free mode of energy conversion, makes it very attractive

Usage of hybrid solar collector system in drying technologies of medical plants

International Nuclear Information System (INIS)

Čiplienė, Aušra; Novošinskas, Henrikas; Raila, Algirdas; Zvicevičius, Egidijus

2015-01-01

Highlights: • Solar radiation energy utilization in drying technologies. • Accumulation of solar radiation energy. • The system comprising two different solar collector types. • Preparation of the drying agent by employing solar radiation energy around the clock. • The energy resources saving technology for medicinal plants’ raw material processing and drying. - Abstract: In the temperate climate zone under natural conditions, medicinal plants drying up to 8–12% moisture content and preparation of the quality medicinal plant’s raw material are complicated tasks. In many cases drying process of medicinal plants raw material, particularly rich in volatile compounds, needs the optimal drying temperatures of 30–45 °C and relative humidity not higher than 50–60%. In Lithuania, located in the northern part of the temperate climate zone, in summer the average temperature of ambient air is 16.1 ± 0.5 °C, and relative humidity is 77.3 ± 1.8%. In order to improve the sorption properties of ambient air, it is heated up to the admissible drying temperature. The experimental dryer was developed comprising two different solar collectors: the air type solar collector with area 12 m 2 for direct heating of the drying agent and the flat-plate type solar collector (8 m 2 ) for accumulation of converted heat energy. The research of motherwort (Leonurus cardiaca L.) drying was carried out in the dryer. It was determined that by combining operation of two different solar collectors, the solar radiation energy for drying agent’s heating could be used continuously around the clock by employing the accumulated energy, in order to compensate the solar irradiance variability and to ensure stability of the drying process. In the daytime the air-type solar collector at an airflow equal to 367 m 3 h −1 , i.e. at comparative flow of the drying agent per ton of dried medicinal plant raw material – 2450 m 3 h −1 , heats the air up to 30 °C when the solar

Evaluation of Test Method for Solar Collector Efficiency

DEFF Research Database (Denmark)

Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

The test method of the standard EN12975-2 (European Committee for Standardization, 2004) is used by European test laboratories to determine the efficiency of solar collectors. In the test methods the mean solar collector fluid temperature in the solar collector, Tm is determined by the approximat...... and the sky temperature. Based on the investigations, recommendations for change of the test methods and test conditions are considered. The investigations are carried out within the NEGST (New Generation of Solar Thermal Systems) project financed by EU.......The test method of the standard EN12975-2 (European Committee for Standardization, 2004) is used by European test laboratories to determine the efficiency of solar collectors. In the test methods the mean solar collector fluid temperature in the solar collector, Tm is determined by the approximated...... equation where Tin is the inlet temperature to the collector and Tout is the outlet temperature from the collector. The specific heat of the solar collector fluid is in the test method as an approximation determined as a constant equal to the specific heat of the solar collector fluid at the temperature Tm...

Behavior of a solar collector loop during stagnation

DEFF Research Database (Denmark)

Chen, Ziqian; Dragsted, Janne; Furbo, Simon

2015-01-01

A mathematical model simulating the emptying behavior of a pressurized solar collector loop with solar collectors with a good emptying behavior is developed and validated with measured data. The calculated results are in good agreement with the measured results. The developed simulation model...... is therefore suitable to determine the behavior of a solar collector loop during stagnation. A volume ratio R, which is the ratio of the volume of the vapour in the upper pipes of the solar collector loop during stagnation and the fluid content of solar collectors, is introduced to determine the mass...... of the collector fluid pushed into the expansion vessel during stagnation, Min. A correlation function for the mass Min and the volume ratio R for solar collector loops is obtained. The function can be used to determine a suitable size of expansion vessels for solar collector loops....

Effect of Installation of Solar Collector on Performance of Balcony Split Type Solar Water Heaters

Directory of Open Access Journals (Sweden)

Xu Ji

2015-01-01

Full Text Available The influences of surface orientation and slope of solar collectors on solar radiation collection of balcony split type solar water heaters for six cities in China were analyzed by employing software TRNSYS. The surface azimuth had greater effect on solar radiation collection in high latitude regions. For deviation of the surface slope angle within ±20° around the optimized angle, the variation of the total annual collecting solar radiation was less than 5%. However, with deviation of 70° to 90°, the variation was up to 20%. The effects of water cycle mode, reverse slope placement of solar collector, and water tank installation height on system efficiency were experimentally studied. The thermal efficiencies of solar water heater with single row horizontal arrangement all-glass evacuated tubular collector were higher than those with vertical arrangement at the fixed surface slope angle of 90°. Compared with solar water heaters with flat-plate collector under natural circulation, the system thermal efficiency was raised up to 63% under forced circulation. For collector at reverse slope placement, the temperature-based water stratification in water tank deteriorated, and thus the thermal efficiency became low. For improving the system efficiency, an appropriate installation height of the water tank was suggested.

Carbonate fuel cell endurance: Hardware corrosion and electrolyte management status

Energy Technology Data Exchange (ETDEWEB)

Yuh, C.; Johnsen, R.; Farooque, M.; Maru, H.

1993-01-01

Endurance tests of carbonate fuel cell stacks (up to 10,000 hours) have shown that hardware corrosion and electrolyte losses can be reasonably controlled by proper material selection and cell design. Corrosion of stainless steel current collector hardware, nickel clad bipolar plate and aluminized wet seal show rates within acceptable limits. Electrolyte loss rate to current collector surface has been minimized by reducing exposed current collector surface area. Electrolyte evaporation loss appears tolerable. Electrolyte redistribution has been restrained by proper design of manifold seals.

Carbonate fuel cell endurance: Hardware corrosion and electrolyte management status

Energy Technology Data Exchange (ETDEWEB)

Yuh, C.; Johnsen, R.; Farooque, M.; Maru, H.

1993-05-01

Endurance tests of carbonate fuel cell stacks (up to 10,000 hours) have shown that hardware corrosion and electrolyte losses can be reasonably controlled by proper material selection and cell design. Corrosion of stainless steel current collector hardware, nickel clad bipolar plate and aluminized wet seal show rates within acceptable limits. Electrolyte loss rate to current collector surface has been minimized by reducing exposed current collector surface area. Electrolyte evaporation loss appears tolerable. Electrolyte redistribution has been restrained by proper design of manifold seals.

Toward designing semiconductor-semiconductor heterojunctions for photocatalytic applications

Science.gov (United States)

Zhang, Liping; Jaroniec, Mietek

2018-02-01

Semiconductor photocatalysts show a great potential for environmental and energy-related applications, however one of the major disadvantages is their relatively low photocatalytic performance due to the recombination of electron-hole pairs. Therefore, intensive research is being conducted toward design of heterojunctions, which have been shown to be effective for improving the charge-transfer properties and efficiency of photocatalysts. According to the type of band alignment and direction of internal electric field, heterojunctions are categorized into five different types, each of which is associated with its own charge transfer characteristics. Since the design of heterojunctions requires the knowledge of band edge positions of component semiconductors, the commonly used techniques for the assessment of band edge positions are reviewed. Among them the electronegativity-based calculation method is applied for a large number of popular visible-light-active semiconductors, including some widely investigated bismuth-containing semiconductors. On basis of the calculated band edge positions and the type of component semiconductors reported, heterojunctions composed of the selected bismuth-containing semiconductors are proposed. Finally, the most popular synthetic techniques for the fabrication of heterojunctions are briefly discussed.

A new desalination system using a combination of heat pipe, evacuated tube and parabolic trough collector

International Nuclear Information System (INIS)

Jafari Mosleh, H.; Jahangiri Mamouri, S.; Shafii, M.B.; Hakim Sima, A.

2015-01-01

Highlights: • A new desalination uses a combination of heat pipe and parabolic trough collector. • A twin-glass evacuated tube is used to decrease the thermal losses from heat pipe. • Adding oil into the space between heat pipe and tube collector enhances the yield. • The yield and efficiency reach up to 0.933 kg/(m 2 h) and 65.2%, respectively. - Abstract: The solar collectors have been commonly used in desalination systems. Recent investigations show that the use of a linear parabolic trough collector in solar stills can improve the efficiency of a desalination system. In this work, a combination of a heat pipe and a twin-glass evacuated tube collector is utilized with a parabolic trough collector. Results show that the rate of production and efficiency can reach to 0.27 kg/(m 2 h) and 22.1% when aluminum conducting foils are used in the space between the heat pipe and the twin-glass evacuated tube collector to transfer heat from the tube collector to the heat pipe. When oil is used as a medium for the transfer of heat, filling the space between heat pipe and twin-glass evacuated tube collector, the production and efficiency can increase to 0.933 kg/(m 2 h) and 65.2%, respectively

The free electron gas primary thermometer using an ordinary bipolar junction transistor approaches ppm accuracy

Science.gov (United States)

Mimila-Arroyo, J.

2017-06-01

In this paper, it is demonstrated that the free electron gas primary thermometer based on a bipolar junction transistor is able to provide the temperature with an accuracy of a few parts per million. Its simple functioning principle exploits the behavior of the collector current when properly biased to extract the temperature. Using general purpose silicon transistors at the water triple point (273.16 K) and gallium melting point (302.9146), an accuracy of a few parts per million has been reached, constituting the simplest and the easiest to operate primary thermometer, that might be considered even for the redefinition of Kelvin.

Standardized performance tests of collectors of solar thermal energy: A selectively coated, steel collector with one transparent cover

Science.gov (United States)

1976-01-01

Basic test results are presented of a flat-plate solar collector whose performance was determined in solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and coolant flow rates. Collector efficiency was correlated in terms of inlet temperature and flux level.

An investigation on the performance characteristics of solar flat plate collector with different selective surface coatings

Energy Technology Data Exchange (ETDEWEB)

Madhukeshwara, N. [Department of Mechanical Engineering, B.I.E.T, Davanagere, Karnataka (India); Prakash, E.S. [Department of Studies in Mechanical Engineering, U.B.D.T.C.E, Davanagere, Karnataka (India)

2012-07-01

In the present work, investigations are made to study performance characteristics of solar flat plate collector with different selective surface coatings. Flat plate collector is one of the important solar energy trapping device which uses air or water as working fluid. Of the many solar collector concepts presently being developed, the relative simple flat plate solar collector has found the widest application so far. Its characteristics are known, and compared with other collector types, it is the easiest and least expensive to fabricate, install, and maintain. Moreover, it is capable of using both the diffuse and the direct beam solar radiation. For residential and commercial use, flat plate collectors can produce heat at sufficiently high temperatures to heat swimming pools, domestic hot water, and buildings; they also can operate a cooling unit, particularly if the incident sunlight is increased by the use of reflector. Temperatures up to 70 C are easily attained by flat plate collectors. With very careful engineering using special surfaces, reflectors to increase the incident radiation and heat resistant materials, higher operating temperatures are feasible.

Standardized performance tests of collectors of solar thermal energy - A flat-plate copper collector with parallel mylar striping

Science.gov (United States)

Johnson, S. M.

1976-01-01

Basic test results are reported for a flat plate solar collector whose performance was determined in a solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and one coolant flow rate. Collector efficiency is correlated in terms of inlet temperature and flux level.

Participation in multilateral effort to develop high performance integrated CPC evacuated collectors

Science.gov (United States)

Winston, R.; Ogallagher, J. J.

1992-05-01

The University of Chicago Solar Energy Group has had a continuing program and commitment to develop an advanced evacuated solar collector integrating nonimaging concentration into its design. During the period from 1985-1987, some of our efforts were directed toward designing and prototyping a manufacturable version of an Integrated Compound Parabolic Concentrator (ICPC) evacuated collector tube as part of an international cooperative effort involving six organizations in four different countries. This 'multilateral' project made considerable progress towards a commercially practical collector. One of two basic designs considered employed a heat pipe and an internal metal reflector CPC. We fabricated and tested two large diameter (125 mm) borosilicate glass collector tubes to explore this concept. The other design also used a large diameter (125 mm) glass tube but with a specially configured internal shaped mirror CPC coupled to a U-tube absorber. Performance projections in a variety of systems applications using the computer design tools developed by the International Energy Agency (IEA) task on evacuated collectors were used to optimize the optical and thermal design. The long-term goal of this work continues to be the development of a high efficiency, low cost solar collector to supply solar thermal energy at temperatures up to 250 C. Some experience and perspectives based on our work are presented and reviewed. Despite substantial progress, the stability of research support and the market for commercial solar thermal collectors were such that the project could not be continued. A cooperative path involving university, government, and industrial collaboration remains the most attractive near term option for developing a commercial ICPC.

-MoS2 Lateral Heterojunctions

KAUST Repository

Li, Ming-yang

2018-02-28

2D layered heterostructures have attracted intensive interests due to their unique optical, transport, and interfacial properties. The laterally stitched heterojunction based on dissimilar 2D transition metal dichalcogenides forms an intrinsic p–n junction without the necessity of applying an external voltage. However, no scalable processes are reported to construct the devices with such lateral heterostructures. Here, a scalable strategy, two-step and location-selective chemical vapor deposition, is reported to synthesize self-aligned WSe2–MoS2 monolayer lateral heterojunction arrays and demonstrates their light-emitting devices. The proposed fabrication process enables the growth of high-quality interfaces and the first successful observation of electroluminescence at the WSe2–MoS2 lateral heterojunction. The electroluminescence study has confirmed the type-I alignment at the interface rather than commonly believed type-II alignment. This self-aligned growth process paves the way for constructing various 2D lateral heterostructures in a scalable manner, practically important for integrated 2D circuit applications.

Embedded Ag Grid Electrodes as Current Collector for Ultraflexible Transparent Solid-State Supercapacitor.

Science.gov (United States)

Xu, Jian-Long; Liu, Yan-Hua; Gao, Xu; Sun, Yilin; Shen, Su; Cai, Xinlei; Chen, Linsen; Wang, Sui-Dong

2017-08-23

Flexible transparent solid-state supercapacitors have attracted immerse attention for the power supply of next-generation flexible "see-through" or "invisible" electronics. For fabrication of such devices, high-performance flexible transparent current collectors are highly desired. In this paper, the utilization of embedded Ag grid transparent conductive electrodes (TCEs) fabricated by a facile soft ultraviolet imprinting lithography method combined with scrap techniques, as the current collector for flexible transparent solid-state supercapacitors, is demonstrated. The embedded Ag grid TCEs exhibit not only excellent optoelectronic properties (R S ∼ 2.0 Ω sq -1 and T ∼ 89.74%) but also robust mechanical properties, which could meet the conductivity, transparency, and flexibility needs of current collectors for flexible transparent supercapacitors. The obtained supercapacitor exhibits large specific capacitance, long cycling life, high optical transparency (T ∼ 80.58% at 550 nm), high flexibility, and high stability. Owing to the embedded Ag grid TCE structure, the device shows a slight capacitance loss of 2.6% even after 1000 cycles of repetitive bending for a bending radius of up to 2.0 mm. This paves the way for developing high-performance current collectors and thus flexible transparent energy storage devices, and their general applicability opens up opportunities for flexible transparent electronics.

DeepBipolar: Identifying genomic mutations for bipolar disorder via deep learning.

Science.gov (United States)

Laksshman, Sundaram; Bhat, Rajendra Rana; Viswanath, Vivek; Li, Xiaolin

2017-09-01

Bipolar disorder, also known as manic depression, is a brain disorder that affects the brain structure of a patient. It results in extreme mood swings, severe states of depression, and overexcitement simultaneously. It is estimated that roughly 3% of the population of the United States (about 5.3 million adults) suffers from bipolar disorder. Recent research efforts like the Twin studies have demonstrated a high heritability factor for the disorder, making genomics a viable alternative for detecting and treating bipolar disorder, in addition to the conventional lengthy and costly postsymptom clinical diagnosis. Motivated by this study, leveraging several emerging deep learning algorithms, we design an end-to-end deep learning architecture (called DeepBipolar) to predict bipolar disorder based on limited genomic data. DeepBipolar adopts the Deep Convolutional Neural Network (DCNN) architecture that automatically extracts features from genotype information to predict the bipolar phenotype. We participated in the Critical Assessment of Genome Interpretation (CAGI) bipolar disorder challenge and DeepBipolar was considered the most successful by the independent assessor. In this work, we thoroughly evaluate the performance of DeepBipolar and analyze the type of signals we believe could have affected the classifier in distinguishing the case samples from the control set. © 2017 Wiley Periodicals, Inc.

Depressed collectors for millimeter wave gyrotrons

International Nuclear Information System (INIS)

Singh, A.; Granatstein, V.L.

1992-01-01

The main issues relating to design of depressed collectors for millimeter wave gyrotrons are discussed. A flow diagram is presented and the interlinking steps are outlined. Design studies are given for two kinds of gyrotrons on which severe constraints on the maximum radii of the collectors had been imposed; namely, for a cavity type and a quasi-optical gyrotron. A collector efficiency of the order of 70 percent is shown to be feasible for either case using careful tailoring of magnetic field profiles. A code has been developed to assist in doing this. A general approach toward initial placement of collectors has been indicated

Solar Heating Systems with Evacuated Tubular Solar Collector

DEFF Research Database (Denmark)

Qin, Lin; Furbo, Simon

1998-01-01

Recently different designed evacuated tubular solar collectors were introduced on the market by different Chinese companies. In the present study, investigations on the performance of four different Chinese evacuated tubular collectors and of solar heating systems using these collectors were...... carried out, employing both laboratory test and theoretical calculations. The collectors were tested in a small solar domestic hot water (SDHW) system in a laboratory test facility under realistic conditions. The yearly thermal performance of solar heating systems with these evacuated tubular collectors......, as well as with normal flat-plate collectors was calculated under Danish weather conditions. It is found that, for small SDHW systems with a combi tank design, an increase of 25% -55% net utilized solar energy can be achieved by using these evacuated tubular collectors instead of normal flat...

Effect of openings collectors and solar irradiance on the thermal efficiency of flat plate-finned collector for indirect-type passive solar dryer

Science.gov (United States)

Batubara, Fatimah; Dina, Sari Farah; Klaudia Kathryn Y., M.; Turmuzi, M.; Siregar, Fitri; Panjaitan, Nora

2017-06-01

Research on the effect of openings solar collector and solar irradiance to thermal efficiency has been done. Solar collector by flat plate-finned type consists of 3 ply insulator namely wood, Styrofoam and Rockwool with thickness respectively are 10 mm, 25 mm and 50 mm. Absorber plate made of aluminum sheet with thickness of 0.30 mm, painted by black-doff. Installation of 19 units fins (length x height x thickness: 1000x20x10 mm) on the collector will increase surface area of absorber so it can receive much more solar energy. The solar collector cover is made of glass (thickness of 5 mm). During the research, the solar irradiance and temperature of collector are measured and recorded every five minutes. Temperature measurement performed on the surface of the absorber plate, inside of collector, surface cover and the outer side insulator (plywood). This data is used to calculate the heat loss due to conduction, convection and radiation on the collector. Openings of collectors vary as follows: 100%, 75%, 15% and 0% (total enclosed). The data collecting was conducted from 09.00 am to 17.00 pm and triplicates. The collector thermal efficiency calculated based on the ratio of the amount of heat received to the solar irradiance absorbed. The results show that each of openings solar collector has different solar irradiance (because it was done on a different day) which is in units of W/m2: 390 (100% open), 376 (75% open), 429 (15% open), and 359 (totally enclosed). The highest thermal efficiency is in openings variation of 15% opened. These results indicate that the efficiency of the collector is influenced by the solar irradiance received by the collector and the temperature on the collector plate. The highest thermal efficiency is in variation of openings 15%. These indicate that the efficiency of the collector was influenced by solar irradiance received by the collector and openings of the collector plate.

COMPARATIVE FIELD EXPERIMENTAL INVESTIGATIONS OF DIFFERENT FLAT PLATE SOLAR COLLECTORS

Directory of Open Access Journals (Sweden)

Guangming Chen

2015-12-01

Full Text Available Full-scale traditional metal solar collectors and solar collector specimens fabricated from polymeric materials were investigated in the present study. A polymeric collector is 67.8% lighter than a traditional metal solar collector, and a metal solar collector with transparent plastic covering is 40.3% lighter than a traditional metal solar collector. Honeycomb multichannel plates made from polycarbonate were chosen to create a polymeric solar collector. A test rig for the natural circulation of the working fluid in a solar collector was built for a comparative experimental investigation of various solar collectors operating at ambient conditions. It was shown experimentally that the efficiency of a polymeric collector is 8–15% lower than the efficiency of a traditional collector.

Drying of fruits and vegetables using a flat plate solar collector with convective air flow

International Nuclear Information System (INIS)

Mansoor, K.K.; Hanif, M.

2011-01-01

This paper presents the analysis of drying of different fruits and vegetables dried by a flat plate solar collector developed at the Department of Agricultural Mechanization, Khyber PukhtunKhwa Agricultural University Peshawar, Pakistan. A small flat plate solar collector is designed and tested for its maximum performance in terms of efficiency with different convective flow rates. The collector assembly is divided into two parts. The flat plate solar collector and the drying chamber. The materials used for flat plate solar collector are wood, steel sheet, Insulation materials, and glass sheet as covering material. The insulation box (0.9 x 1.8 x 0.3 meter) is made up of wood of popular and deodar, to be fully isolated with the help of polystyrene. The absorber is black painted v-corrugated steel sheet. Collector has a tilt angle of 34 deg. (Equivalent to the latitude of Peshawar). The covering material is (0.9 x 1.8 meter) and 5 mm thick glass sheet placed at the top of the wooden box. The collector is supported and tilted with the help of a frame made up of iron angled arms. While the drying chamber is a (1 X 0.5 x 0.3 meter) wooden box connected to the outlet duct of the collector with the help of polyvinylchloride pipe. Experiments were conducted different fruits and vegetables and different parameters like moisture lost by the products in each hour, drying rate at each hour of drying, humidity and temperature of the drying chamber. It was observed that the products such as bitter guard and onion were dried in 10 to 2 hours up to moisture content less then 8%. These two product lost 8% to 10% moisture during each hour of drying. While grapes and Green chili are dried in 24 to 25 hours up to moisture content less then 8%. These two products lost 4% to 5% moisture in each hour of drying. The drying rate of all the products dried was very much consistent. It was observed that onion and bitter guard showed a good drying rate of 0.03[g(H/sub 2/O)/g(d.m).cm/ 2 hr] to

Annual measured and simulated thermal performance analysis of a hybrid solar district heating plant with flat plate collectors and parabolic trough collectors in series

DEFF Research Database (Denmark)

Tian, Zhiyong; Perers, Bengt; Furbo, Simon

2017-01-01

Flat plate collectors have relatively low efficiency at the typical supply temperatures of district heating networks (70–95 °C). Parabolic trough collectors retain their high efficiency at these temperatures. To maximize the advantages of flat plate collectors and parabolic trough collectors in l...... for this type of hybrid solar district heating plants with flat plate collectors and parabolic trough collectors in the Nordic region, but also introduce a novel design concept of solar district heating plants to other high solar radiation areas....... in large solar heating plants for a district heating network, a hybrid solar collector field with 5960 m2 flat plate collectors and 4039 m2 parabolic trough collectors in series was constructed in Taars, Denmark. The design principle is that the flat plate collectors preheat the return water from...

A YinYang bipolar fuzzy cognitive TOPSIS method to bipolar disorder diagnosis.

Science.gov (United States)

Han, Ying; Lu, Zhenyu; Du, Zhenguang; Luo, Qi; Chen, Sheng

2018-05-01

Bipolar disorder is often mis-diagnosed as unipolar depression in the clinical diagnosis. The main reason is that, different from other diseases, bipolarity is the norm rather than exception in bipolar disorder diagnosis. YinYang bipolar fuzzy set captures bipolarity and has been successfully used to construct a unified inference mathematical modeling method to bipolar disorder clinical diagnosis. Nevertheless, symptoms and their interrelationships are not considered in the existing method, circumventing its ability to describe complexity of bipolar disorder. Thus, in this paper, a YinYang bipolar fuzzy multi-criteria group decision making method to bipolar disorder clinical diagnosis is developed. Comparing with the existing method, the new one is more comprehensive. The merits of the new method are listed as follows: First of all, multi-criteria group decision making method is introduced into bipolar disorder diagnosis for considering different symptoms and multiple doctors' opinions. Secondly, the discreet diagnosis principle is adopted by the revised TOPSIS method. Last but not the least, YinYang bipolar fuzzy cognitive map is provided for the understanding of interrelations among symptoms. The illustrated case demonstrates the feasibility, validity, and necessity of the theoretical results obtained. Moreover, the comparison analysis demonstrates that the diagnosis result is more accurate, when interrelations about symptoms are considered in the proposed method. In a conclusion, the main contribution of this paper is to provide a comprehensive mathematical approach to improve the accuracy of bipolar disorder clinical diagnosis, in which both bipolarity and complexity are considered. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparison of three different collectors for process heat applications

Science.gov (United States)

Brunold, Stefan; Frey, R.; Frei, Ulrich

1994-09-01

In general vacuum tube collectors are used in solar process heat systems. Another possibility is to use transparent insulated flat plate collectors. A critical point however, is that most of the common transparent insulating materials can not withstand high temperatures because they consist of plastics. Thus, temperature resistive collector covers combining a high tranmisivity with a low U-value are required. One possibility is to use capillaries made of glass instead of plastics. Measurement results of collector efficiency and incident angle modifier will be presented as well as calculated energy gains for three different collectors: a vacuum tube collector (Giordano Ind., France), a CPC vacuum tube collector (microtherm Energietechnik Germany; a new flat plate collector using glass capillary as transparent insulation (SET, Germany).

Development of a selective thin film and of a hermetically sealed flat plate solar collector with gas filling

Science.gov (United States)

Zernial, W.

1982-12-01

The industrial productibility of a selective absorbing thin film was investigated on the basis of reactive cathodic sputtering of Ni. On substrates of 1.8 sq m of Al, Cu, steel and stainless steel, solar absorption values up to 97% were achieved at emissivities of 5 to 10%. A prototype flat plate collector for high temperatures with two covers and hermetical sealing was developed. The technical data of the collector were measured, dependent on the selectivity of the absorber, gas fillings of dry air, argon or SF6 and the geometry and were compared with those of an evacuated flat plate collector. A hermetical sealed double flat plate collector for low temperatures was developed which has the advantage of lower no load temperatures and higher energy gain for heating swimming pool water compared with a conventional flat plate collector. The insolation values on collectors were measured and were used for a calculation of the energy gains of different collector types.

A new concept of hybrid photovoltaic thermal (PVT) collector with natural circulation

Science.gov (United States)

Lu, Longsheng; Wang, Xiaowu; Wang, Shuai; Liu, Xiaokang

2017-07-01

Hybrid photovoltaic thermal (PVT) technology refers to the integration of a photovoltaic module into a conventional solar thermal collector. Generally, the traditional design of a PVT collector has solar cells fixed on the top surface of an absorber in a flat-plate solar thermal collector. In this work, we presented a new concept of water-based PVT collector in which solar cells were directly placed on the bottom surface of its glass cover. A dynamic numerical model of this new PVT is developed and validated by experimental tests. With numerical analysis, it is found that at same covering factor, the electricity conversion efficiency of solar cells of the new PVT exceed that of the traditional PVT by nearly 10% while its thermal efficiency is approximately 30% lower than that of the traditional PVT. When the covering factor changes from 0.05 to 1, the thermal efficiency of the new PVT drops nearly 70%. The thermal efficiency of both the new PVT and the traditional PVT rise up as the water mass in tank increases. Meanwhile, the final water temperature in tank of the traditional PVT collector declines more than 17 °C, whereas that of the new PVT declines less than 6 °C, when the water mass increases from 100 to 300 kg.

Risk of bipolar disorder among adolescents with allergic rhinitis: A nationwide longitudinal study.

Science.gov (United States)

Chen, Mu-Hong; Lan, Wen-Hsuan; Hsu, Ju-Wei; Huang, Kai-Lin; Chen, Ying-Sheue; Li, Cheng-Ta; Lin, Wei-Chen; Chang, Wen-Han; Chen, Tzeng-Ji; Pan, Tai-Long; Su, Tung-Ping; Bai, Ya-Mei

2015-12-01

Previous studies have suggested an immunological dysfunction in bipolar disorder, but none has investigated the temporal association between allergic rhinitis (AR) and bipolar disorder. Using Taiwan National Health Insurance Research Database, 9506 adolescents aged 12-18 years with allergic rhinitis were enrolled between 2000 and 2008 and compared to 38,024 age-and gender-matched (1:4) control groups. Subjects of bipolar disorder that occurred up to the end of follow-up (December 31, 2011) were identified. Adolescents with AR had a significantly higher incidence of developing bipolar disorder (0.77 vs. 0.18 per 1000 person-years, pAdolescents with AR had an increased risk (hazard ratio [HR]: 4.62, 95% confidence interval [CI]: 3.17-6.75) of developing bipolar disorder in their later life compared to the control group after adjusting for demographic data and comorbid allergic diseases. This is the first study showing a temporal association between AR and bipolar disorder, in that patients who had AR in adolescence exhibited an increased risk of developing bipolar disorder in later life. Further study would be required to investigate the underlying mechanism about this association. Copyright © 2015 Elsevier Inc. All rights reserved.

One-way optical transmission in silicon photonic crystal heterojunction with circular and square scatterers

Energy Technology Data Exchange (ETDEWEB)

Liu, Dan, E-mail: liudanhu725@126.com [School of Physics and Mechanical & Electrical Engineering, Hubei University of Education, Wuhan, 430205 (China); Hu, Sen [School of Physics and Mechanical & Electrical Engineering, Hubei University of Education, Wuhan, 430205 (China); Gao, Yihua [Wuhan National Laboratory for Optoelectronics (WNLO), School of Physics, Huazhong University of Science and Technology (HUST), Wuhan, 430074 (China)

2017-07-12

A 2D orthogonal square-lattice photonic crystal (PC) heterojunction consisting of circular and square air holes in silicon is presented. Band structures are calculated using the plane wave expansion method, and the transmission properties are investigated by the finite-different time-domain simulations. Thanks to the higher diffraction orders excited when the circular and square holes are interlaced along the interface, one-way transmission phenomena can exist within wide frequency regions. The higher order diffraction is further enhanced through two different interface optimization designs proposed by modifying the PC structure of the hetero-interface. An orthogonal PC heterojunction for wide-band and efficient one-way transmission is constructed, and the maximum transmissivity is up to 78%. - Highlights: • Photonic crystal heterojunction with circular and square scatterers is first studied. • One-way transmission efficiency is closely related to the hetero-interface. • Wide-band and efficient one-way transmission is realized.

Monolayered Bi2WO6 nanosheets mimicking heterojunction interface with open surfaces for photocatalysis

Science.gov (United States)

Zhou, Yangen; Zhang, Yongfan; Lin, Mousheng; Long, Jinlin; Zhang, Zizhong; Lin, Huaxiang; Wu, Jeffrey C.-S.; Wang, Xuxu

2015-09-01

Two-dimensional-layered heterojunctions have attracted extensive interest recently due to their exciting behaviours in electronic/optoelectronic devices as well as solar energy conversion systems. However, layered heterojunction materials, especially those made by stacking different monolayers together by strong chemical bonds rather than by weak van der Waal interactions, are still challenging to fabricate. Here the monolayer Bi2WO6 with a sandwich substructure of [BiO]+-[WO4]2--[BiO]+ is reported. This material may be characterized as a layered heterojunction with different monolayer oxides held together by chemical bonds. Coordinatively unsaturated Bi atoms are present as active sites on the surface. On irradiation, holes are generated directly on the active surface layer and electrons in the middle layer, which leads to the outstanding performances of the monolayer material in solar energy conversion. Our work provides a general bottom-up route for designing and preparing novel monolayer materials with ultrafast charge separation and active surface.

Small-Scale Flat Plate Collectors for Solar Thermal Scavenging in Low Conductivity Environments

Directory of Open Access Journals (Sweden)

Emmanuel Ogbonnaya

2017-01-01

Full Text Available There is great opportunity to develop power supplies for autonomous application on the small scale. For example, remote environmental sensors may be powered through the harvesting of ambient thermal energy and heating of a thermoelectric generator. This work investigates a small-scale (centimeters solar thermal collector designed for this application. The absorber is coated with a unique selective coating and then studied in a low pressure environment to increase performance. A numerical model that is used to predict the performance of the collector plate is developed. This is validated based on benchtop testing of a fabricated collector plate in a low-pressure enclosure. Model results indicate that simulated solar input of about 800 W/m2 results in a collector plate temperature of 298 K in ambient conditions and up to 388 K in vacuum. The model also predicts the various losses in W/m2 K from the plate to the surroundings. Plate temperature is validated through the experimental work showing that the model is useful to the future design of these small-scale solar thermal energy collectors.

Modelling of Microclimate in collectors

DEFF Research Database (Denmark)

Holck, Ole

1996-01-01

Abstract It is important to avoid condensation in solar collectors, most of all because wetness of the absorber can damage the selective surface and cause corrosion on the absorber plate. During night time the cover of collectors will cool below ambient temperature due to thermal radiation...

Fractionated bipolar radiofrequency and bipolar radiofrequency potentiated by infrared light for treating striae: A prospective randomized, comparative trial with objective evaluation.

Science.gov (United States)

Harmelin, Yona; Boineau, Dominique; Cardot-Leccia, Nathalie; Fontas, Eric; Bahadoran, Philippe; Becker, Anne-Lise; Montaudié, Henri; Castela, Emeline; Perrin, Christophe; Lacour, Jean-Philippe; Passeron, Thierry

2016-03-01

Very few treatments for striae are based on prospective randomized trials. The objective of this study was to assess the efficacy of bipolar fractional radiofrequency and bipolar radiofrequency potentiated with infrared light, alone or combined, for treating abdominal stretch marks. Bicentric prospective interventional randomized controlled trial in the department of Dermatology of University Hospital of Nice and Aesthetics Laser Center of Bordeaux, France. Men and women of age 18 years or above, who presented for the treatment of mature or immature abdominal striae were included. The patients' abdomens were divided into four equal quadrants. Bipolar radiofrequency potentiated with infrared light and fractional bipolar radiofrequency were applied, alone or combined, and compared to the remaining untreated quadrant. The main criterion of evaluation was the measurement of depth of striae, using 3D photography at 6 months follow-up. A global assessment was also rated by the physician performing the treatment and by the patients. Histological analysis and confocal laser microscopy were additionally performed. A total of 22 patients were enrolled, and 384 striae were measured. In per protocol analysis mean striae depth was decreased by 21.64%, observed at 6 months follow-up with the combined approach, compared to an increase of 1.73% in the control group (P radiofrequency, combined with bipolar radiofrequency potentiated by infrared light, is an effective treatment of both immature and mature striae of the abdomen. © 2016 Wiley Periodicals, Inc.

Standardized performance tests of collectors of solar thermal energy: An evacuated flatplate copper collector with a serpentine flow distribution

Science.gov (United States)

Johnson, S. M.

1976-01-01

Basic test results are given for a flat plate solar collector whose performance was determined in the NASA-Lewis solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and one coolant flow rate. Collector efficiency is correlated in terms of inlet temperature and flux level.

Interfacial recombination at /AlGa/As/GaAs heterojunction structures

Science.gov (United States)

Ettenberg, M.; Kressel, H.

1976-01-01

Experiments were conducted to determine the interfacial recombination velocity at Al0.25Ga0.75As/GaAs and Al0.5Ga0.5As/GaAs heterojunctions. The recombination velocity was derived from a study of the injected minority-carrier lifetime as a function of the junction spacing. It is found that for heterojunction spacings in excess of about 1 micron, the interfacial recombination can be characterized by a surface recombination velocity of 4,000 and 8,000 cm/sec for the two types of heterojunctions, respectively. For double-heterojunction spacings below 1 micron, the constancy of the minority-carrier lifetime suggests that the interfacial recombination velocity decreases effectively. This effect is technologically very important since it makes it possible to construct very low-threshold injection lasers. No such effect is observed in single-heterojunction diodes.

Solution-Processed In2O3/ZnO Heterojunction Electron Transport Layers for Efficient Organic Bulk Heterojunction and Inorganic Colloidal Quantum-Dot Solar Cells

KAUST Repository

Eisner, Flurin

2018-04-25

We report the development of a solution‐processed In2O3/ZnO heterojunction electron transport layer (ETL) and its application in high efficiency organic bulk‐heterojunction (BHJ) and inorganic colloidal quantum dot (CQD) solar cells. Study of the electrical properties of this low‐dimensional oxide heterostructure via field‐effect measurements reveals that electron transport along the heterointerface is enhanced by more than a tenfold when compared to the individual single‐layer oxides. Use of the heterojunction as the ETL in organic BHJ photovoltaics is found to consistently improve the cell\\'s performance due to the smoothening of the ZnO surface, increased electron mobility and a noticeable reduction in the cathode\\'s work function, leading to a decrease in the cells’ series resistance and a higher fill factor (FF). Specifically, non‐fullerene based organic BHJ solar cells based on In2O3/ZnO ETLs exhibit very high power conversion efficiencies (PCE) of up to 12.8%, and high FFs of over 70%. The bilayer ETL concept is further extended to inorganic lead‐sulphide CQD solar cells. Resulting devices exhibit excellent performance with a maximum PCE of 8.2% and a FF of 56.8%. The present results highlight the potential of multilayer oxides as novel ETL systems and lay the foundation for future developments.

Solution-Processed In2O3/ZnO Heterojunction Electron Transport Layers for Efficient Organic Bulk Heterojunction and Inorganic Colloidal Quantum-Dot Solar Cells

KAUST Repository

Eisner, Flurin; Seitkhan, Akmaral; Han, Yang; Khim, Dongyoon; Yengel, Emre; Kirmani, Ahmad R.; Xu, Jixian; Garcí a de Arquer, F. Pelayo; Sargent, Edward H.; Amassian, Aram; Fei, Zhuping; Heeney, Martin; Anthopoulos, Thomas D.

2018-01-01

We report the development of a solution‐processed In2O3/ZnO heterojunction electron transport layer (ETL) and its application in high efficiency organic bulk‐heterojunction (BHJ) and inorganic colloidal quantum dot (CQD) solar cells. Study of the electrical properties of this low‐dimensional oxide heterostructure via field‐effect measurements reveals that electron transport along the heterointerface is enhanced by more than a tenfold when compared to the individual single‐layer oxides. Use of the heterojunction as the ETL in organic BHJ photovoltaics is found to consistently improve the cell's performance due to the smoothening of the ZnO surface, increased electron mobility and a noticeable reduction in the cathode's work function, leading to a decrease in the cells’ series resistance and a higher fill factor (FF). Specifically, non‐fullerene based organic BHJ solar cells based on In2O3/ZnO ETLs exhibit very high power conversion efficiencies (PCE) of up to 12.8%, and high FFs of over 70%. The bilayer ETL concept is further extended to inorganic lead‐sulphide CQD solar cells. Resulting devices exhibit excellent performance with a maximum PCE of 8.2% and a FF of 56.8%. The present results highlight the potential of multilayer oxides as novel ETL systems and lay the foundation for future developments.

CarbonNanoTubes (CNT) in bipolar plates for PEM fuel cell applications

Energy Technology Data Exchange (ETDEWEB)

Grundler, M.; Derieth, T.; Beckhaus, P.; Heinzel, A. [centre for fuel cell technology ZBT GmbH (Germany)

2010-07-01

Using standard mass production techniques for the fabrication of fuel cell components, such as bipolar plates, is a main issue for the commercialisation of PEM fuel cell systems. Bipolar plates contribute significantly to the cost structure of PEM stacks. In an upcoming fuel cell market a large number of bipolar plates with specific high-quality standards will be needed. At the Centre for Fuel Cell Technology (ZBT) together with the University of Duisburg-Essen fuel cell stacks based on injection moulded bipolar plates have been developed and demonstrated successfully [1]. This paper focuses on the interactions between carbon filling materials (graphite, carbon black and carbon nanotubes (CNT)) in compound based bipolar plates and especially the potential of CNTs, which were used in bipolar plates for the first time. The entire value added chain based on the feedstock, the compounding and injection moulding process, the component bipolar plate, up to the operation of a PEM single fuel cell stack with CNT-based bipolar plates is disclosed. (orig.)

Thermal performance of a transpired solar collector updraft tower

International Nuclear Information System (INIS)

Eryener, Dogan; Hollick, John; Kuscu, Hilmi

2017-01-01

Highlights: • Transpired solar collector updraft tower has been studied experimentally. • Transpired solar collector updraft tower efficiency ranges from 60 to 80%. • A comparison has been made with other SUT prototypes. • Three times higher efficiency compared to the glazed collectors of conventional solar towers. - Abstract: A novel solar updraft tower prototype, which consists of transpired solar collector, is studied, its function principle is described and its experimental thermal performance is presented for the first time. A test unit of transpired solar collector updraft tower was installed at the campus of Trakya University Engineering Faculty in Edirne-Turkey in 2014. Solar radiation, ambient temperature, collector cavity temperatures, and chimney velocities were monitored during summer and winter period. The results showed that transpired solar collector efficiency ranges from 60% to 80%. The maximum temperature rise in the collector area is found to be 16–18 °C on the typical sunny day. Compared to conventional solar tower glazed collectors, three times higher efficiency is obtained. With increased thermal efficiency, large solar collector areas for solar towers can be reduced in half or less.

Current collectors for improved safety

Science.gov (United States)

Abdelmalak, Michael Naguib; Allu, Srikanth; Dudney, Nancy J.; Li, Jianlin; Simunovic, Srdjan; Wang, Hsin

2017-12-19

A battery electrode assembly includes a current collector with conduction barrier regions having a conductive state in which electrical conductivity through the conduction barrier region is permitted, and a safety state in which electrical conductivity through the conduction barrier regions is reduced. The conduction barrier regions change from the conductive state to the safety state when the current collector receives a short-threatening event. An electrode material can be connected to the current collector. The conduction barrier regions can define electrical isolation subregions. A battery is also disclosed, and methods for making the electrode assembly, methods for making a battery, and methods for operating a battery.

AEROSOL PARTICLE COLLECTOR DESIGN STUDY

Energy Technology Data Exchange (ETDEWEB)

Lee, S; Richard Dimenna, R

2007-09-27

A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.

Bipolar disorders

DEFF Research Database (Denmark)

Vieta, Eduard; Berk, Michael; Schulze, Thomas G

2018-01-01

Bipolar disorders are chronic and recurrent disorders that affect >1% of the global population. Bipolar disorders are leading causes of disability in young people as they can lead to cognitive and functional impairment and increased mortality, particularly from suicide and cardiovascular disease...... and accurate diagnosis is difficult in clinical practice as the onset of bipolar disorder is commonly characterized by nonspecific symptoms, mood lability or a depressive episode, which can be similar in presentation to unipolar depression. Moreover, patients and their families do not always understand...... a bipolar disorder from other conditions. Optimal early treatment of patients with evidence-based medication (typically mood stabilizers and antipsychotics) and psychosocial strategies is necessary....

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...... approach offers a systematic explanation of how such bipolar structures appear and can be identified....

Precursors in adolescence of adult-onset bipolar disorder.

Science.gov (United States)

Hiyoshi, Ayako; Sabet, Julia A; Sjöqvist, Hugo; Melinder, Carren; Brummer, Robert J; Montgomery, Scott

2017-08-15

Although the estimated contribution of genetic factors is high in bipolar disorder, environmental factors may also play a role. This Swedish register-based cohort study of men examined if physical and psychological characteristics in late adolescence, including factors previously linked with bipolar disorder (body mass index, asthma and allergy), are associated with subsequent bipolar disorder in adulthood. Unipolar depression and anxiety are analysed as additional outcomes to identify bipolar disorder-specific associations. A total of 213,693 men born between 1952 and 1956, who participated in compulsory military conscription assessments in late adolescence were followed up to 2009, excluding men with any psychiatric diagnoses at baseline. Cox regression estimated risk of bipolar disorder, depression and anxiety in adulthood associated with body mass index, asthma, allergy, muscular strength stress resilience and cognitive function in adolescence. BMI, asthma and allergy were not associated with bipolar disorder. Higher grip strength, cognitive function and stress resilience were associated with a reduced risk of bipolar disorder and the other disease outcomes. The sample consisted only of men; even though the characteristics in adolescence pre-dated disease onset, they may have been the consequence of prodromal disease. Associations with body mass index and asthma found by previous studies may be consequences of bipolar disorder or its treatment rather than risk factors. Inverse associations with all the outcome diagnoses for stress resilience, muscular strength and cognitive function may reflect general risks for these psychiatric disorders or intermediary factors. Copyright © 2017 Elsevier B.V. All rights reserved.

Clinical practice recommendations for bipolar disorder.

Science.gov (United States)

Malhi, G S; Adams, D; Lampe, L; Paton, M; O'Connor, N; Newton, L A; Walter, G; Taylor, A; Porter, R; Mulder, R T; Berk, M

2009-01-01

To provide clinically relevant evidence-based recommendations for the management of bipolar disorder in adults that are informative, easy to assimilate and facilitate clinical decision-making. A comprehensive literature review of over 500 articles was undertaken using electronic database search engines (e.g. MEDLINE, PsychINFO and Cochrane reviews). In addition articles, book chapters and other literature known to the authors were reviewed. The findings were then formulated into a set of recommendations that were developed by a multidisciplinary team of clinicians who routinely deal with mood disorders. These preliminary recommendations underwent extensive consultative review by a broader advisory panel that included experts in the field, clinical staff and patient representatives. The clinical practice recommendations for bipolar disorder (bipolar CPR) summarise evidence-based treatments and provide a synopsis of recommendations relating to each phase of the illness. They are designed for clinical use and have therefore been presented succinctly in an innovative and engaging manner that is clear and informative. These up-to-date recommendations provide an evidence-based framework that incorporates clinical wisdom and consideration of individual factors in the management of bipolar disorder. Further, the novel style and practical approach should promote their uptake and implementation.

The Thermal Collector With Varied Glass Covers

International Nuclear Information System (INIS)

Luminosu, I.; Pop, N.

2010-01-01

The thermal collector with varied glass covers represents an innovation realized in order to build a collector able to reach the desired temperature by collecting the solar radiation from the smallest surface, with the highest efficiency. In the case of the thermal collector with variable cover glasses, the number of the glass plates covering the absorber increases together with the length of the circulation pipe for the working fluid. The thermal collector with varied glass covers compared to the conventional collector better meet user requirements because: for the same temperature increase, has the collecting area smaller; for the same collection area, realizes the highest temperature increase and has the highest efficiency. This works is addressed to researchers in the solar energy and to engineers responsible with air-conditioning systems design or industrial and agricultural products drying.

Experimental investigation of a solar collector integrated with a pulsating heat pipe and a compound parabolic concentrator

International Nuclear Information System (INIS)

Xu, Rong Ji; Zhang, Xiao Hui; Wang, Rui Xiang; Xu, Shu Hui; Wang, Hua Sheng

2017-01-01

Highlights: • Solar collector integrates compound parabolic concentrator and pulsating heat pipe. • Concentrator of a concentration ratio 3.4 matches well heat flux of heat pipe. • Solar collector efficiency increases with decreasing absorber thermal resistance. • Maximum 50% efficiency of the integrated solar collector has been achieved. - Abstract: The paper reports an experimental investigation of a newly proposed solar collector that integrates a closed-end pulsating heat pipe (PHP) and a compound parabolic concentrator (CPC). The PHP is used as an absorber due to its simple structure and high heat transfer capacity. The CPC has a concentration ratio of 3.4 and can be readily manufactured by three-dimensional printing. The CPC can significantly increase the incident solar irradiation intensity to the PHP absorber and also reduce the heat loss due to the decrease in the area of the hot surface. A prototype of the solar collector has been built, consisting of a PHP absorber bent by 4 mm diameter copper tube, CPC arrayed by 10 × 2 CPC units with the collection area of 300 × 427.6 mm 2 , a hot water tank and a glass cover. HFE7100 was utilized as the working fluid at a filling ratio of 40%. The operating characteristics and thermal efficiency of the solar collector were experimentally studied. The steady and periodic temperature fluctuations of the evaporation and condensation sections of the PHP absorber indicate that the absorber works well with a thermal resistance of about 0.26 °C/W. It is also found that, as the main factor to the the thermal performance of the collector, thermal resistance of the PHP absorber decreases with increasing evaporation temperature. The collector apparently shows start-up, operational and shutdown stages at the starting and ending temperatures of 75 °C. When the direct normal irradiance is 800 W/m 2 , the instantaneous thermal efficiency of the solar collector can reach up to 50%.

Pathways toward a low cost evacuated collector system

Science.gov (United States)

Hull, J. R.; Schertz, W. W.; Allen, J. W.; Ogallagher, J. J.; Winston, R.

The goal of widespread use of solar thermal collectors will only be achieved when they are proven to be economically superior to competing energy sources. Evacuated tubular collectors appear to have the potential to achieve this goal. An advanced evacuated collector using nonimaging concentration under development at the University of Chicago and Argonne can achieve a 50% seasonal efficiency at heat delivery temperatures in excess of 170C. The same collector has an optical efficiency so that low temperature performance is also excellent. In this advanced collector design all of the critical components are enclosed in the vacuum, and the collector has an inherently long lifetime. The current cost of evacuated systems is too high, mainly because the volume of production has been too low to realize economies of mass production. It appears that certain design features of evacuated collectors can be changed (e.g., use of heat pipe absorbers) so as to introduce new system design and market strategy options that can reduce the balance of system cost.

Air solar collectors in building use - A review

Science.gov (United States)

Bejan, Andrei-Stelian; Labihi, Abdelouhab; Croitoru, Cristiana; Catalina, Tiberiu

2018-02-01

In the current energy and environmental context it is imperative to implement systems based on renewable energy sources in order to reduce energy consumptions worldwide. Solar collectors are studied by many years and many researchers are focusing their attention in order to increase their efficiency and cost-effectiveness. Water solar collectors are often implemented for domestic hot water, heating or industrial processes and already have a place on the market. A promising system which is not yet widely known is represented by air solar collectors that could represent an efficient way to use the solar energy with a lower investment cost, a system that can be used in order to preheat the fresh air required for heating, drying, or to maintain a minimum temperature during winter. This paper presents a comprehensive literature review on air solar collectors used mainly in buildings, acting as a solar wall. Air solar collectors are roughly classified into two types: glazed and opaque. The present study comprises the solar collector classification, applications and their main parameters with a special focus on opaque solar collectors.

Air solar collectors in building use - A review

Directory of Open Access Journals (Sweden)

Bejan Andrei-Stelian

2018-01-01

Full Text Available In the current energy and environmental context it is imperative to implement systems based on renewable energy sources in order to reduce energy consumptions worldwide. Solar collectors are studied by many years and many researchers are focusing their attention in order to increase their efficiency and cost-effectiveness. Water solar collectors are often implemented for domestic hot water, heating or industrial processes and already have a place on the market. A promising system which is not yet widely known is represented by air solar collectors that could represent an efficient way to use the solar energy with a lower investment cost, a system that can be used in order to preheat the fresh air required for heating, drying, or to maintain a minimum temperature during winter. This paper presents a comprehensive literature review on air solar collectors used mainly in buildings, acting as a solar wall. Air solar collectors are roughly classified into two types: glazed and opaque. The present study comprises the solar collector classification, applications and their main parameters with a special focus on opaque solar collectors.

Rates and predictors of remission, recurrence and conversion to bipolar disorder after the first lifetime episode of depression--a prospective 5-year follow-up study.

Science.gov (United States)

Bukh, J D; Andersen, P K; Kessing, L V

2016-04-01

In depression, non-remission, recurrence of depressive episodes after remission and conversion to bipolar disorder are crucial determinants of poor outcome. The present study aimed to determine the cumulative incidences and clinical predictors of these long-term outcomes after the first lifetime episode of depression. A total of 301 in- or out-patients aged 18-70 years with a validated diagnosis of a single depressive episode were assessed from 2005 to 2007. At 5 years of follow-up, 262 patients were reassessed by means of the life chart method and diagnostic interviews from 2011 to 2013. Cumulative incidences and the influence of clinical variables on the rates of remission, recurrence and conversion to bipolar disorder, respectively, were estimated by survival analysis techniques. Within 5 years, 83.3% obtained remission, 31.5% experienced recurrence of depression and 8.6% converted to bipolar disorder (6.3% within the first 2 years). Non-remission increased with younger age, co-morbid anxiety and suicidal ideations. Recurrence increased with severity and treatment resistance of the first depression, and conversion to bipolar disorder with treatment resistance, a family history of affective disorder and co-morbid alcohol or drug abuse. The identified clinical characteristics of the first lifetime episode of depression should guide patients and clinicians for long-term individualized tailored treatment.

Solar collector design with respect to moisture problems

DEFF Research Database (Denmark)

Holck, Ole; Svendsen, Svend; Brunold, Stefan

2003-01-01

more ventilation openings should be made and what influence the insulation material has. Guidelines for collector designers are proposed. The design guidelines provide some suggestions to be considered during the design of solar collectors.The work was carried out within the framework of the working...... group Materials in Solar Thermal Collectors of the International Energy Agency-Solar Heating and Cooling Programme....... the design of the collector, the location and size of ventilation holes, properties of the insulation materials and dimension of the solar collector box are parameters that have to be taken into account for the optimisation in order to achieve the most favourable microclimate to prevent corrosion...

A solar energy collector

Energy Technology Data Exchange (ETDEWEB)

Vasil' yev, L.L.; Avakyan, Yu.V.; Bogdanov, V.M.; Gagiyan, L.A.; Grakovich, L.P.; Karapetyan, G.S.; Morgun, V.A.

1984-01-01

A collector whose primary component is a heating pipe is proposed. The evaporation zone located in the lower half of the heating pipe has an external absorption coating. Chambers that open upward and contain the evaporating fluid are mounted within this region along the top. In order to improve operational reliability of the collector, these chambers are mounted on one coated wall; the area of projection of each of the chambers onto the horizontal plane is greater than the area of the projection of each of the chambers placed above it. The coating may be in the form of photocells; a filter is mounted on the chamber side inside the evaporation zone. The evaporation zone may take the form of a cylinder with a segmented base; the photocells are mounted on a flat section of the lateral surface. The collector may be used to cool the photocells.

Bicentric bipolar hip prosthesis: A radiological study of movement at the interprosthetic joint

Directory of Open Access Journals (Sweden)

Anil Kumar Rai

2011-01-01

Full Text Available Background: The bipolar hip prostheses after some time functions as a unipolar device. There is a need to change the design of bipolar hip prostheses to make it function as a bipolar device over a prolonged period of time. A bicentric bipolar hip prosthesis was used as an implant for various conditions of the hip. We evaluated the movement of this newly developed prosthesis at the interprosthetic joint radiologically at periodic intervals. Materials and Methods: Fifty two cases were operarted with the Bicentric bipolar prosthesis for indications like fracture neck of femur and various other diseases of the hip and were followed up with serial radiographs at periodic intervals to evaluate, what fraction of the total abduction at the hip was occurring at the interprosthetic joint. Results: In cases of intracapsular fracture neck of femur, the percentage of total abduction occurring at the interprosthetic joint at 3 months follow-up was 33.74% (mean value of all the patients, which fell to 25.66% at 1.5 years. In indications for bipolar hemireplacement other than fracture neck of femur, the percentage of total abduction occurring at the interprosthetic joint at 3 months follow-up was 71.71% (mean value and at 1.5 years it was 67.52%. Conclusion: This study shows the relative preservation of inner bearing movement in the bipolar hip prosthesis with time probably due its refined design. Further refinements are needed to make the prosthesis work better in patients of intracapsular fracture neck femur.

Identifying early indicators in bipolar disorder: a qualitative study.

Science.gov (United States)

Benti, Liliane; Manicavasagar, Vijaya; Proudfoot, Judy; Parker, Gordon

2014-06-01

The identification of early markers has become a focus for early intervention in bipolar disorder. Using a retrospective, qualitative methodology, the present study compares the early experiences of participants with bipolar disorder to those with unipolar depression up until their first diagnosed episode. The study focuses on differences in early home and school environments as well as putative differences in personality characteristics between the two groups. Finally we a compare and contrast prodromal symptoms in these two populations. Thirty-nine participants, 20 diagnosed with unipolar depression and 19 diagnosed with bipolar disorder, took part in the study. A semi-structured interview was developed to elicit information about participants' experiences prior to their first episode. Participants with bipolar disorder reported disruptive home environments, driven personality features, greater emotion dysregulation and adverse experiences during the school years, whereas participants with depression tended to describe more supportive home environments, and more compliant and introvert personality traits. Retrospective data collection and no corroborative evidence from other family members. No distinction was made between bipolar I and bipolar II disorder nor between melancholic and non-melancholic depression in the sample. Finally the study spanned over a 12-month period which does not allow for the possibility of diagnostic reassignment of some of the bipolar participants to the unipolar condition. These findings indicate that there may be benefits in combining both proximal and distal indicators in identifying a bipolar disorder phenotype which, in turn, may be relevant to the development of early intervention programs for young people with bipolar disorder.

The thermodynamics of bipolarity: a bifurcation model of bipolar illness and bipolar character and its psychotherapeutic applications.

Science.gov (United States)

Sabelli, H C; Carlson-Sabelli, L; Javaid, J I

1990-11-01

Two models dominate current formulations of bipolar illness: the homeostatic model implicit in Freud's psychodynamics and most neuroamine deficit/excess theories; and the oscillatory model of exaggerated biological rhythms. The homeostatic model is based on the closed systems approach of classic thermodynamics, while the oscillatory model requires the open systems approach of modern thermodynamics. Here we present a thermodynamic model of bipolarity that includes both homeostatic and oscillatory features and adds the most important feature of open systems thermodynamics: the creation of novel structures in bifurcation processes. According to the proposed model, bipolarity is the result of exaggerated biological energy that augments homeostatic, oscillatory and creative psychological processes. Only low-energy closed systems tend to rest ("point attractor") and entropic disorder. Open processes containing and exchanging energy fluctuate between opposite states ("periodic attractors"); they are characteristic of most physiological rhythms and are exaggerated in bipolar subjects. At higher energies, their strong fluctuations destroy pre-existing patterns and structures, produce turbulence ("chaotic attractors"), which sudden switches between opposite states, and create new and more complex structures. Likewise, high-energy bipolars develop high spontaneity, great fluctuations between opposite moods, internal and interpersonal chaos, and enhanced creativity (personal, artistic, professional) as well as psychopathology (personality deviations, psychotic delusions). Offered here is a theoretical explanation of the dual--creative and destructive--nature of bipolarity in terms of the new enantiodromic concept of entropy generalized by process theory. Clinically, this article offers an integrative model of bipolarity that accounts for many clinical features and contributes to a definition of the bipolar personality.

Fabrication and characterization of photosensitive n-ZnO/p-InSe heterojunctions

Energy Technology Data Exchange (ETDEWEB)

Kudrynskyi, Z., E-mail: kudrynskyi@gmail.com [Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, Chernivtsi Branch, Str. I. Vilde 5, 58001 Chernivtsi (Ukraine); Khomyak, V. [Yuriy Fedkovich Chernivtsi National University, Str. Kotsubinsky 2, 58012 Chernivtsi (Ukraine); Katerynchuk, V.; Kovalyuk, M.; Netyaga, V.; Kushnir, B. [Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, Chernivtsi Branch, Str. I. Vilde 5, 58001 Chernivtsi (Ukraine)

2015-05-01

Indium monochalcogenide (InSe) with a band gap of 1.25 eV is a promising material for photovoltaic applications. In this work, photosensitive anisotype n-ZnO/p-InSe heterojunctions were fabricated by means of radio-frequency magnetron sputtering of the zinc oxide onto freshly cleaved (0001) van der Waals surface of p-InSe single-crystal. Structural properties of the obtained heterostructures were investigated by means of X-ray diffraction. Surface morphology of the grown ZnO thin films was studied by means of atomic force microscopy. The electrical and photoelectrical properties of the heterojunctions were investigated using the current-voltage characteristics measured at different temperatures, capacitance-voltage characteristics and photoresponse spectra. The dominating current transport mechanisms through the heterojunctions under investigation were determined at forward and reverse biases. It was found that the developed heterojunctions n-ZnO/p-InSe show photosensitivity in the photon energy range (1.25-3.20 eV) at room temperature. In addition, we analyzed the influence of vacuum annealing of the heterojunctions at different temperatures on their photoelectric properties. - Highlights: • Thin ZnO films were grown onto van der Waals surface of InSe substrate. • n-ZnO/p-InSe heterojunctions were fabricated. • The heterojunctions are photosensitive in photon energy range from 1.12 to 3.75 eV. • Despite the lattice mismatch of 19% the heterojunctions exhibit diode-like behavior. • Vacuum annealing improves electrical properties of the heterojunctions.

Comorbidity of bipolar disorder and eating disorders.

Science.gov (United States)

Álvarez Ruiz, Eva M; Gutiérrez-Rojas, Luis

2015-01-01

The comorbidity of bipolar disorder and eating disorders has not been studied in depth. In addition, clinical implications involved in the appearance of both disorders are very important. A systematic literature review of MEDLINE published up to September 2013 was performed, analyzing all the articles that studied the comorbidity of both conditions (bipolar disorder and eating disorders) and others research that studied the efficacy of pharmacological treatment and psychotherapy to improve these illnesses. In this review we found a high comorbidity of bipolar disorder and eating disorders, especially of bulimia nervosa and binge eating disorder. Studies show that lithium and topiramate are 2 of the more effective pharmacological agents in the treatment of both disorders. There are a lot of studies that show evidence of comorbidity of bipolar disorder and eating disorders. However, further research is needed on assessment and treatment when these conditions co-exist, as well as study into the biopsychological aspects to determine the comorbid aetiology. Copyright © 2014 SEP y SEPB. Published by Elsevier España. All rights reserved.

Flat plate collector. Solarflachkollektor

Energy Technology Data Exchange (ETDEWEB)

Raab, N

1979-03-29

The invention refers to a flat solar collector with an absorber plate, which is arranged on a support and is covered by a transparent window, between which and the plate there is an air space. The previously known structures of this type had the disadvantage that the thermal expansion of the enclosed air caused considerable difficulties. The purpose of the invention is therefore to create a collector, which can be used on the modular system, retains its properties and is safe in spite of the great temperature variations. According to the invention this problem is solved by providing a compensating space in the collector, which is separated by a diaphragm from the airspace between the plate and the covering window. The airspace therefore remains sealed against the atmosphere, so that no dirt, corrosion of the inside and no condensation can reduce the efficiency of the collector. A rise in pressure due to an increase in temperature is immediately reduced by expansion of the diaphragm, which enters the compensation space. In order to increase the pressure in the airspace above the plate for increases in temperature, the compensation space is connected to the atmosphere. The diaphragm can be mirrored on the side towards the absorber, which makes the diaphragm into an insulating element, as it reflects radiated heat from the absorber.

[Circadian markers and genes in bipolar disorder].

Science.gov (United States)

Yeim, S; Boudebesse, C; Etain, B; Belliviera, F

2015-09-01

Bipolar disorder is a severe and complex multifactorial disease, characterized by alternance of acute episodes of depression and mania/hypomania, interspaced by euthymic periods. The etiological determinants of bipolar disorder yet, are still poorly understood. For the last 30 years, chronobiology is an important field of investigation to better understand the pathophysiology of bipolar disorder. We conducted a review using Medline, ISI Database, EMBase, PsyInfo up to January 2015, using the following keywords combinations: "mood disorder", "bipolar disorder", "depression", "unipolar disorder", "major depressive disorder", "affective disorder", for psychiatric conditions; and "circadian rhythms", "circadian markers", "circadian gene", "clock gene", "melatonin" for circadian rhythms. The search critera was presence of word in any field of the article. Quantitative and qualitative circadian abnormalities are associated with bipolar disorders both during acute episodes and euthymic periods, suggesting that these altered circadian rhythms may represent biological trait markers of the disorder. These circadian dysfunctions were assessed by various validated tools including polysomnography, actigraphy, sleep diaries, chronotype assessments and blood melatonin/cortisol measures. Other altered endogenous circadian activities have also been reported in bipolar patients, such as hormones secretion, core body temperature or fibroblasts activity. Moreover, these markers were also altered in healthy relatives of bipolar patients, suggesting a degree of heritability. Several genetic association studies have also showed associations between multiple circadian genes and bipolar disorder, such as CLOCK, ARTNL1, GSK3β, PER3, NPAS2, NR1D1, TIMELESS, RORA, RORB, and CSNK1ε. Thus, these circadian gene variants may contribute to the genetic susceptibility of the disease. Furthermore, the study of the clock system may help to better understand some phenotypic aspects like the

Standardized performance tests of collectors of solar thermal energy-a flat-plate collector with a single-tube serpentine flow distribution

Science.gov (United States)

Johnson, S.

1976-01-01

This preliminary data report gives basic test results of a flat-plate solar collector whose performance was determined in the NASA-Lewis solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and coolant flow rates. Collector efficienty is correlated in terms of inlet temperature and flux level.

Bariatric surgery in patients with bipolar spectrum disorders: Selection factors, post-operative visit attendance, and weight outcomes

Science.gov (United States)

Friedman, Kelli E.; Applegate, Katherine; Portenier, Dana; McVay, Megan

2017-01-01

Background As many of 3% of bariatric surgery candidates are diagnosed with a bipolar spectrum disorder. Objectives 1) To describe differences between patients with bipolar spectrum disorders who are approved and not approved for surgery by the mental health evaluator. 2) To examine surgical outcomes of patients with bipolar spectrum disorders. Setting Academic medical center, United States. Methods A retrospective record review was conducted of consecutive patients who applied for bariatric surgery between 2004 and 2009. Patients diagnosed with bipolar spectrum disorders who were approved for surgery (n=42) were compared with patients with a bipolar spectrum disorder who were not approved (n=31) and to matched control surgical patients without a bipolar spectrum diagnosis (n=29) on a variety of characteristics and surgical outcomes. Results Of bariatric surgery candidates diagnosed with a bipolar spectrum disorder who applied for surgery, 57% were approved by the psychologist and 48% ultimately had surgery. Patients with a bipolar spectrum disorder who were approved for surgery were less likely to have had a previous psychiatric hospitalizations than those who were not approved for surgery. Bariatric surgery patients diagnosed with a bipolar spectrum disorder were less likely to attend follow-up care appointments 2 or more years post-surgery compared to matched patients without bipolar disorder. Among patients with available data, those with a bipolar spectrum disorder and matched patients had similar weight loss at 12 months (n=21 for bipolar, n=24 for matched controls) and at 2 or more years (mean=51 months; n=11 for bipolar, n=20 for matched controls). Conclusions Patients diagnosed with a bipolar spectrum disorder have a high rate of delay/denial for bariatric surgery based on the psychosocial evaluation and are less likely to attend medical follow-up care 2 or more years post-surgery. Carefully screened patients with bipolar disorder who engage in long

Charge Separation at Mixed-Dimensional Single and Multilayer MoS2/Silicon Nanowire Heterojunctions.

Science.gov (United States)

Henning, Alex; Sangwan, Vinod K; Bergeron, Hadallia; Balla, Itamar; Sun, Zhiyuan; Hersam, Mark C; Lauhon, Lincoln J

2018-05-16

Layered two-dimensional (2-D) semiconductors can be combined with other low-dimensional semiconductors to form nonplanar mixed-dimensional van der Waals (vdW) heterojunctions whose charge transport behavior is influenced by the heterojunction geometry, providing a new degree of freedom to engineer device functions. Toward that end, we investigated the photoresponse of Si nanowire/MoS 2 heterojunction diodes with scanning photocurrent microscopy and time-resolved photocurrent measurements. Comparison of n-Si/MoS 2 isotype heterojunctions with p-Si/MoS 2 heterojunction diodes under varying biases shows that the depletion region in the p-n heterojunction promotes exciton dissociation and carrier collection. We measure an instrument-limited response time of 1 μs, which is 10 times faster than the previously reported response times for planar Si/MoS 2 devices, highlighting the advantages of the 1-D/2-D heterojunction. Finite element simulations of device models provide a detailed understanding of how the electrostatics affect charge transport in nanowire/vdW heterojunctions and inform the design of future vdW heterojunction photodetectors and transistors.

Bipolar Disorder and Heart Transplantation: A Case Report.

Science.gov (United States)

Ramírez-Giraldo, Ana María; Restrepo, Diana

Bipolar disorder is a chronic and recurrent mood disease that includes symptoms that fluctuate from euphoria to depression. As a mood disorder, itis one of the main contraindications for transplantation procedures. The case is presented of a patient with bipolar disorder who had a heart transplant after a cardiac arrest. Heart transplantation is the treatment of choice in patients with heart failure and arrhythmias that do not respond to conventional treatment. Case report and narrative review of literature. A 34-year-old woman with bipolar disorder diagnosed when she was 13, treated with lithium and aripiprazole. She required a heart transplant as the only therapeutic option, after presenting with ventricular tachycardia refractory to conventional treatment. The patient did not suffer an emotional decompensation with the removal of the lithium and aripiprazole that were associated with prolonged QTc interval, and remained eurhythmic throughout the process. Heart transplantation can be performed safely and successfully in patients with bipolar disorder, when suitably followed-up by a liaison psychiatry group. Bipolar disorder should not be considered as an absolute contraindication for heart transplantation. Copyright © 2017 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Foldable Frame Supporting Electromagnetic Radiation Collectors

DEFF Research Database (Denmark)

2011-01-01

The present invention relates to flexible frames supporting electromagnetic radiation collectors, such as antennas, antenna reflectors, deflectors or solar collectors, for celestial or terrestrial applications, which can be folded to be stored and/or transported. The method for stowing deforms...

OUT Success Stories: Transpired Solar Collectors

International Nuclear Information System (INIS)

Clyne, R.

2000-01-01

Transpired solar collectors are a reliable, low-cost technology for preheating building ventilation air. With simple payback periods ranging from 3 to 12 years and an estimated 30-year life span, transpired collector systems offer building owners substantial cost savings

Determination of band offsets at strained NiO and MgO heterojunction for MgO as an interlayer in heterojunction light emitting diode applications

Energy Technology Data Exchange (ETDEWEB)

Singh, S.D., E-mail: devsh@rrcat.gov.in [Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013 (India); Nand, Mangla [Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085 (India); Ajimsha, R.S.; Upadhyay, Anuj; Kamparath, Rajiv; Mukherjee, C.; Misra, P.; Sinha, A.K. [Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013 (India); Jha, S.N. [Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085 (India); Ganguli, Tapas [Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013 (India)

2016-12-15

Highlights: • Valence band offset at NiO/MgO heterojunction is experimentally determined. • Experimentally determined value of 2.3 ± 0.4 eV is significantly larger than the predicted from theoretical calculations. • The value of valence band offset is in corroboration with that estimated from the band transitivity model. • Our result can be used to predict accurately carrier transport and electroluminescence mechanisms for heterojunction LEDs. - Abstract: Valence band offset of 2.3 ± 0.4 eV at strained NiO/MgO heterojunction is determined from photoelectron spectroscopy (PES) measurements. The determined value of valence band offset is larger than that is predicted from first principle calculations, but is in corroboration with that obtained from band transitivity rule. Our PES result indicates a larger value of the valence band offset at strained NiO/MgO heterojunction and can be used to predict accurately carrier transport and electroluminescence mechanisms for n-ZnO/MgO/p-NiO and p-NiO/MgO/n-GaN heterojunction light emitting diodes.

Bipolar disorder in adolescence.

Science.gov (United States)

DeFilippis, Melissa; Wagner, Karen Dineen

2013-08-01

Bipolar disorder is a serious psychiatric condition that may have onset in childhood. It is important for physicians to recognize the symptoms of bipolar disorder in children and adolescents in order to accurately diagnose this illness early in its course. Evidence regarding the efficacy of various treatments is necessary to guide the management of bipolar disorder in youth. For example, several medications commonly used for adults with bipolar disorder have not shown efficacy for children and adolescents with bipolar disorder. This article reviews the prevalence, diagnosis, course, and treatment of bipolar disorder in children and adolescents and provides physicians with information that will aid in diagnosis and treatment.

Efficiency of the Fermilab Electron Cooler's Collector

CERN Document Server

Prost, L R

2005-01-01

The newly installed high-energy Recycler Electron Cooling system (REC) at Fermilab will work at an electron energy of 4.34 MeV and a DC beam current of 0.5 A in an energy recovery scheme. For reliable operation of the system, the relative beam current loss must be maintained to levels < 3.e-5. Experiments have shown that the loss is determined by the performance of the electron beam collector, which must retain secondary electrons generated by the primary beam hitting its walls. As a part of the Electron cooling project, the efficiency of the collector for the REC was optimized, both with dedicated test bench experiments and on two versions of the cooler prototype. We find that to achieve the required relative current loss, an axially-symmetric collector must be immersed in a transverse magnetic field with certain strength and gradient prescriptions. Collector efficiencies in various magnetic field configurations, including without a transverse field on the collector, are presented and discussed

An improved dynamic test method for solar collectors

DEFF Research Database (Denmark)

Kong, Weiqiang; Wang, Zhifeng; Fan, Jianhua

2012-01-01

A comprehensive improvement of the mathematical model for the so called transfer function method is presented in this study. This improved transfer function method can estimate the traditional solar collector parameters such as zero loss coefficient and heat loss coefficient. Two new collector...... parameters t and mfCf are obtained. t is a time scale parameter which can indicate the heat transfer ability of the solar collector. mfCf can be used to calculate the fluid volume content in the solar collector or to validate the regression process by comparing it to the physical fluid volume content...... for the second-order differential term with 6–9min as the best averaging time interval. The measured and predicted collector power output of the solar collector are compared during a test of 13days continuously both for the ITF method and the QDT method. The maximum and averaging error is 53.87W/m2 and 5.22W/m2...

The seroprevalence of antithyroid peroxidase antibodies in bipolar families and bipolar twins: results from two longitudinal studies.

Science.gov (United States)

Snijders, G; de Witte, L; Mesman, E; Kemner, S; Vonk, R; Brouwer, R; Nolen, W A; Drexhage, H A; Hillegers, M H J

2017-12-01

Previous studies of our group among bipolar offspring and bipolar twins showed significant higher prevalence's and levels of antithyroid peroxidase antibodies (TPO-Abs) in offspring and co-twins (without a mood disorder) compared to controls, suggesting that TPO-Abs might be considered as vulnerability factor (trait marker) for BD development. Here we elucidate, in the same cohorts, but now after 12- and 6-year follow-up, whether TPO-abs should be considered as a 'trait' marker for BD. The present study aims to investigate whether TPO-Abs (1) are stable over time, (2) are associated with lithium-exposure, (3) share a common genetic background with BD and are related to psychopathology. In bipolar offspring and twins, the prevalence of TPO-Abs is stable over time (r s  = .72 p bipolar offspring (10,4% versus 4%) and higher TPO-abs titers were still present in co-twins of bipolar cases compared to control twins [mean 1.06 IU/ml (SD .82) versus mean .82 IU/ml (SD .67)], although statistical significance was lost. Although our results show a trend toward an increased inherited risk of the co-occurrence of BD and thyroid autoimmunity, large-scale studies can only draw final conclusions. Nationwide epidemiological and GWAS studies reach such numbers and support the view of a possible common (autoimmune) etiology of severe mood disorders and chronic recurrent infections and autoimmunity, including thyroid autoimmunity.

Childhood CBCL Bipolar Profile and Adolescent/Young Adult Personality Disorders: A 9-year Follow-up

Science.gov (United States)

Halperin, Jeffrey M.; Rucklidge, Julia J.; Powers, Robyn L.; Miller, Carlin J.; Newcorn, Jeffrey H.

2010-01-01

Background To assess the late adolescent psychiatric outcomes associated with a positive Child Behavior Checklist – Juvenile Bipolar Disorder Phenotype (CBCL-JBD) in children diagnosed with ADHD and followed over a 9-year period. Methods Parents of 152 children diagnosed as ADHD (ages 7–11 years) completed the CBCL. Ninety of these parents completed it again 9 years later as part of a comprehensive evaluation of Axis I and II diagnoses as assessed using semi-structured interviews. As previously proposed, the CBCL-JBD phenotype was defined as T-scores of 70 or greater on the Attention Problems, Aggression, and Anxiety/Depression subscales. Results The CBCL-JBD phenotype was found in 31% of those followed but only 4.9% of the sample continued to meet the phenotype criteria at follow up. Only two of the sample developed Bipolar Disorder by late adolescence and only one of those had the CBCL-JBD profile in childhood. The proxy did not predict any Axis I disorders. However, the CBCL-JBD proxy was highly predictive of later personality disorders. Limitations Only a subgroup of the original childhood sample was followed. Given this sample was confined to children with ADHD, it is not known whether the prediction of personality disorders from CBCL scores would generalize to a wider community or clinical population Conclusions A positive CBCL-JBD phenotype profile in childhood does not predict Axis I Disorders in late adolescence; however, it may be prognostic of the emergence of personality disorders. PMID:21056910

Movable air solar collector and its efficiency

International Nuclear Information System (INIS)

Lauva, A.; Aboltinš, A.; Palabinskis, J.; Karpova Sadigova, N.

2008-01-01

Implementing the guidelines of the Latvian National Programme for Energy in the field of alternative energy, intensive research shall be carried on regarding the use of solar energy, as it can be successfully used not only for the purposes of water heating and production of electrical energy, but also for air warming. The amount of heat necessary for the drying of rough forage and grain drying by active aeration in June, July and August can be obtained using solar radiation. The Latvian Guidelines for the Energy Development 2006-2016 state that the solar radiance in Latvia is of quite low intensity. The total amount of solar energy is 1109 kWh m -2 per year. The period of usage of the solar thermal energy is beginning from the last decade of April, when the intensity of radiation is 120 kWh m -2 , until the first decade of September. Within this period (approximately 1800 hours), it is possible to use the solar thermal energy by placing solar collectors. The usage of solar collectors for in drying of agricultural production is topical from the viewpoint of decreasing the consumption of energy used for the drying, as electrical energy and fossil energy resources become more expensive and tend to run out. In the processes that concern drying of agricultural production, efficiently enough solar radiation energy can be used. Due to this reason researching continues and expands in the field of usage of solar energy for the processes of drying and heating. The efficiency factor of the existing solar collectors is not high, but they are of simple design and cheep for production and exploitation. By improving the design of the solar collectors and choosing modern materials that absorb the solar radiation energy, it is possible the decrease the efficiency factor of solar collectors and decrease the production costs. In the scientific laboratory of grain drying and storage of Latvia University of Agriculture, a pilot device movable folding solar collector pilot device

Organic semiconductor heterojunctions and its application in organic light-emitting diodes

CERN Document Server

Ma, Dongge

2017-01-01

This book systematically introduces the most important aspects of organic semiconductor heterojunctions, including the basic concepts and electrical properties. It comprehensively discusses the application of organic semiconductor heterojunctions as charge injectors and charge generation layers in organic light-emitting diodes (OLEDs). Semiconductor heterojunctions are the basis for constructing high-performance optoelectronic devices. In recent decades, organic semiconductors have been increasingly used to fabricate heterojunction devices, especially in OLEDs, and the subject has attracted a great deal of attention and evoked many new phenomena and interpretations in the field. This important application is based on the low dielectric constant of organic semiconductors and the weak non-covalent electronic interactions between them, which means that they easily form accumulation heterojunctions. As we know, the accumulation-type space charge region is highly conductive, which is an important property for high...

Does Treatment of the Tibia Matter in Bipolar Chondral Defects of the Knee? Clinical Outcomes with Greater Than 2 Years Follow-up.

Science.gov (United States)

Hannon, Charles P; Weber, Alexander E; Gitelis, Matthew; Meyer, Maximillian A; Yanke, Adam B; Cole, Brian J

2018-04-01

To compare the osteochondral allograft (OCA) outcomes of bipolar defects with isolated femoral defects and to investigate the optimal treatment of bipolar defects by comparing femoral OCA with tibial debridement to femoral OCA and tibial microfracture. A series of patients with 2-year follow-up from March 2004 to September 2015 after femoral OCA for bipolar chondral defects was identified. Group 1 contained patients with tibial defects treated with debridement and group 2 contained patients with microfractured tibial defects. A third group (group 3) with isolated femoral defects treated with OCA was identified and matched by gender, body mass index (BMI), laterality, and OCA size to groups 1 and 2. Patient-specific, defect-specific, intraoperative, and postoperative data including patient-reported outcomes were collected on all patients. The study groups were compared using analyses of variance, paired sample t tests, and χ-square analyses. Thirty-six patients who had femoral OCA for bipolar lesions were identified with 20 patients in group 1 and 16 patients in group 2. Group 3 had 20 patients. There were no differences between the 3 groups in terms of gender (P = .616), BMI (P = .271), number of previous surgeries (P = .451), femoral or tibial defect size (P = .296), and OCA size (P = .981). Preoperative to postoperative patient-reported clinical outcomes (PROs) revealed statistical and clinically meaningful improvement in all 3 groups, but did not differ between groups. Patient-specific and defect-specific factors did not correlate with PROs. The graft survivorship for group 1 was 85% at 4.5 years, 100% for group 2 at 2.5 years, and 95% for group 3 at 3.8 years. Regardless of tibial treatment, patients with bipolar defects treated with femoral OCA have clinically meaningful improvements in PROs and excellent graft survivorship comparable to isolated femoral OCAs at more than 2 years. Level III, case-control study. Copyright © 2017 Arthroscopy

Epidemiology and burden of bipolar disorder in Africa: a systematic review of data from Africa.

Science.gov (United States)

Esan, Oluyomi; Esan, Arinola

2016-01-01

Bipolar disorder impacts negatively on the patient, the family, as well as the society. It taxes the health care services due to a combination of the illness with associated medical and psychiatric comorbidities. In Africa, unfortunately, knowledge of the epidemiology and burden of bipolar disorder is based mainly on studies from the USA and Europe. In this systematic review of literature from Africa, we highlight the epidemiology and burden of bipolar disorder. A systematic review of publications from Africa relating to the epidemiology and burden of bipolar disorder was conducted. Data from community surveys conducted in Nigeria and Ethiopia indicated a lifetime prevalence estimate of 0.1 % to 1.83 for bipolar disorder. Missed diagnosis rate of bipolar disorder was up to 36.2 %. In one study, 8.1 % of the males and 5.4 % of the females reported a previous suicide attempt. A study showed that up to 60 % of patients with bipolar disorder had at least one comorbidity. There were no reports on all-cause mortality and cost of illness. Bipolar disorder is a major mental health problem in Africa. Scientific findings on bipolar disorder from Africa are consistent with the existing literature from other parts of the world. There still exists a dearth of high quality studies addressing the epidemiological, clinical, social, and economic burden of the disorder.

Multi-channel unidirectional transmission of phononic crystal heterojunctions

Science.gov (United States)

Xu, Zhenlong; Tong, Jie; Wu, Fugen

2018-02-01

Two square steel columns are arranged in air to form two-dimensional square lattice phononic crystals (PNCs). Two PNCs can be combined into a non-orthogonal 45∘ heterojunction when the difference in the directional band gaps of the two PNC types is utilized. The finite element method is used to calculate the acoustic band structure, the heterogeneous junction transmission characteristics, acoustic field distribution, and many others. Results show that a non-orthogonal PNC heterojunction can produce a multi-channel unidirectional transmission of acoustic waves. With the square scatterer rotated, the heterojunction can select a frequency band for unidirectional transmission performance. This capability is particularly useful for constructing acoustic diodes with wide-bands and high-efficiency unidirectional transmission characteristics.

Thermal analysis of gyrotron traveling-wave tube collector

International Nuclear Information System (INIS)

Zheng Zhiqing; Luo Yong; Jiang Wei; Tang Yong

2013-01-01

In order to solve cooling problem of the gyrotron traveling-wave tube(TWT) collector and guarantee the gyrotron TWT's reliability and stability, the electron trajectories in the gyrotron TWT are simulated using CST electron simulation software. Thermal analysis of the collector with finite element software ANSYS is performed. The ways of applying boundary that affects the distribution of collector temperature are compared. The influence of the water temperature and flow rate on collector temperature distribution under actual heat fluxes (boundary condition) is researched. The size and number of collector fins are optimized, and a relatively perfect structure is obtained finally. The result estimated by simulation is consistent with the experiment and proves that the model and method employed in this work are suitable. (authors)

Metal-free current collectors based on graphene materials for supecapacitors produced by 3D printing

Science.gov (United States)

Baskakov, S. A.; Baskakova, Yu. V.; Lyskov, N. V.; Dremova, N. N.; Shul'ga, Yu. M.

2017-10-01

Supercapacitor (SC) current collectors with electrodes made of graphite oxide reduced during microwave exfoliation are produced from a commercial filament with a graphene component via layer-by-layer fusing with a 3D printer. The separator is made of a graphene oxide film. The current collectors are investigated by means of IR spectroscopy. Electrochemical tests are performed for the assembled SC that include tests of its cyclic stability up to 1000 cycles.

Optimal design of orientation of PV/T collector with reflectors

International Nuclear Information System (INIS)

Kostic, Lj.T.; Pavlovic, T.M.; Pavlovic, Z.T.

2010-01-01

Hybrid conversion of solar radiation implies simultaneous solar radiation conversion into thermal and electrical energy in the PV/Thermal collector. In order to get more thermal and electrical energy, flat solar radiation reflectors have been mounted on PV/T collector. To obtain higher solar radiation intensity on PV/T collector, position of reflectors has been changed and optimal position of reflectors has been determined by both experimental measurements and numerical calculation so as to obtain maximal concentration of solar radiation intensity. The calculated values have been found to be in good agreement with the measured ones, both yielding the optimal position of the flat reflector to be the lowest (5 o ) in December and the highest (38 o ) in June. In this paper, the thermal and electrical efficiency of PV/T collector without reflectors and with reflectors in optimal position have been calculated. Using these results, the total efficiency and energy-saving efficiency of PV/T collector have been determined. Energy-saving efficiency for PV/T collector without reflectors is 60.1%, which is above the conventional solar thermal collector, whereas the energy-saving efficiency for PV/T collector with reflectors in optimal position is 46.7%, which is almost equal to the values for conventional solar thermal collector. Though the energy-saving efficiency of PV/T collector decreases slightly with the solar radiation intensity concentration factor, i.e. the thermal and electrical efficiency of PV/T collector with reflectors are lower than those of PV/T collector without reflectors, the total thermal and electrical energy generated by PV/T collector with reflectors in optimal position are significantly higher than total thermal and electrical energy generated by PV/T collector without reflectors.

Next Generation Solar Collectors for CSP

Energy Technology Data Exchange (ETDEWEB)

Molnar, Attila [3M Company, St. Paul, MN (United States); Charles, Ruth [3M Company, St. Paul, MN (United States)

2014-07-31

The intent of “Next Generation Solar Collectors for CSP” program was to develop key technology elements for collectors in Phase 1 (Budget Period 1), design these elements in Phase 2 (Budget Period 2) and to deploy and test the final collector in Phase 3 (Budget Period 3). 3M and DOE mutually agreed to terminate the program at the end of Budget Period 1, primarily due to timeline issues. However, significant advancements were achieved in developing a next generation reflective material and panel that has the potential to significantly improve the efficiency of CSP systems.

Sub-bandgap response of graphene/SiC Schottky emitter bipolar phototransistor examined by scanning photocurrent microscopy

Science.gov (United States)

Barker, Bobby G., Jr.; Chava, Venkata Surya N.; Daniels, Kevin M.; Chandrashekhar, M. V. S.; Greytak, Andrew B.

2018-01-01

Graphene layers grown epitaxially on SiC substrates are attractive for a variety of sensing and optoelectronic applications because the graphene acts as a transparent, conductive, and chemically responsive layer that is mated to a wide-bandgap semiconductor with large breakdown voltage. Recent advances in control of epitaxial growth and doping of SiC epilayers have increased the range of electronic device architectures that are accessible with this system. In particular, a recently-introduced Schottky-emitter bipolar phototransistor (SEPT) based on an epitaxial graphene (EG) emitter grown on a p-SiC base epilayer has been found to exhibit a maximum common emitter current gain of 113 and a UV responsivity of 7.1 A W-1. The behavior of this device, formed on an n +-SiC substrate that serves as the collector, was attributed to a very large minority carrier injection efficiency at the EG/p-SiC Schottky contact. This large minority carrier injection efficiency is in turn related to the large built-in potential found at a EG/p-SiC Schottky junction. The high performance of this device makes it critically important to analyze the sub bandgap visible response of the device, which provides information on impurity states and polytype inclusions in the crystal. Here, we employ scanning photocurrent microscopy (SPCM) with sub-bandgap light as well as a variety of other techniques to clearly demonstrate a localized response based on the graphene transparent electrode and an approximately 1000-fold difference in responsivity between 365 nm and 444 nm excitation. A stacking fault propagating from the substrate/epilayer interface, assigned as a single layer of the 8H-SiC polytype within the 4H-SiC matrix, is found to locally increase the photocurrent substantially. The discovery of this polytype heterojunction opens the potential for further development of heteropolytype devices based on the SEPT architecture.

Molecular design of flotation collectors: A recent progress.

Science.gov (United States)

Liu, Guangyi; Yang, Xianglin; Zhong, Hong

2017-08-01

The nature of froth flotation is to selectively hydrophobize valuable minerals by collector adsorption so that the hydrophobized mineral particles can attach air bubbles. In recent years, the increasing commercial production of refractory complex ores has been urgent to develop special collectors for enhancing flotation separation efficiency of valuable minerals from these ores. Molecular design methods offer an effective way for understanding the structure-property relationship of flotation collectors and developing new ones. The conditional stability constant (CSC), molecular mechanics (MM), quantitative structure-activity relationship (QSAR), and first-principle theory, especially density functional theory (DFT), have been adopted to build the criteria for designing flotation collectors. Azole-thiones, guanidines, acyl thioureas and thionocarbamates, amide-hydroxamates, and double minerophilic-group surfactants such as Gemini, dithiourea and dithionocarbamate molecules have been recently developed as high-performance collectors. To design hydrophobic groups, the hydrophilic-hydrophobic balance parameters have been extensively used as criteria. The replacement of aryl group with aliphatic group or CC single bond(s) with CC double bond(s), reduction of carbon numbers, introduction of oxygen atom(s) and addition of trisiloxane to the tail terminal have been proved to be useful approaches for adjusting the surface activity of collectors. The role of molecular design of collectors in practical flotation applications was also summarized. Based on the critical review, some comments and prospects for further research on molecular design of flotation collectors were also presented in the paper. Copyright © 2017 Elsevier B.V. All rights reserved.

Bipolar Disorder

Science.gov (United States)

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

Structural, electronic and transport properties of armorphous/crystalline silicon heterojunctions

Energy Technology Data Exchange (ETDEWEB)

Schulze, Tim Ferdinand

2011-06-15

The present dissertation is concerned with the physical aspects of the a-Si:H/c-Si heterojunction in the context of PV research. In a first step, the technological development which took place in the framework of the thesis is summarized. Its main constituent was the development and implementation of ultrathin ({<=}10 nm) undoped a-Si:H[(i)a-Si:H] layers to improve the passivation of the c-Si surface with the goal of increasing the open-circuit voltage of the solar cell. It is shown that the effect of (i)a-Si:H interlayers depends on the c-Si substrate doping type, and that challenges exist particularly on the technologically more relevant (n)c-Si substrate. A precise optimization of (i)a-Si:H thickness and the doping level of the following a-Si:H top layers is required to realize an efficiency gain in the solar cell. In this chapter, the key scientific questions to be tackled in the main part of the thesis are brought up by the technological development. In the next chapter, the charge carrier transport through a-Si:H/c-Si heterojunctions is investigated making use of current-voltage (I/V) characteristics taken at different temperatures. The dominant transport mechanisms in a-Si:H/c-Si heterojunctions are identified, and the relevance for solar cell operation is discussed. It is found that in the bias regime relevant for solar cell operation, the theoretical framework for the description of carrier transport in classical c-Si solar cells applies as well, which enables to use I/V curves for a simple characterization of a-Si:H/c-Si structures. The next chapter deals with the microscopic characterization of ultrathin a-Si:H layers. Employing infrared spectroscopy, spectroscopic ellipsometry, photoelectron spectroscopy and secondary ion mass spectroscopy, the structural, electronic and optical properties of (i)a-Si:H are analyzed. It is found that ultrathin a-Si:H essentially behaves like layers of 10..100 times the thickness. This represents the basis for the

Efficiency improvement of flat plate solar collector using reflector

Directory of Open Access Journals (Sweden)

Himangshu Bhowmik

2017-11-01

Full Text Available Solar collectors are the main components of a solar heating system. The collectors collect the sun’s energy, transform this radiation into heat, and then transfer this heat into a fluid, water or air, which has many household or industrial applications. This paper introduces a new technology to improve the performance of the solar thermal collectors. The solar reflector used here with the solar collector to increase the reflectivity of the collector. Thus, the reflector concentrates both direct and diffuse radiation of the sun toward the collector. To maximize the intensity of incident radiation, the reflector was allowed to change its angle with daytime. The radiations coming from the sun’s energy were converted into heat, and then this heat was transferred to the collector fluid, water. A prototype of a solar water heating system was constructed and obtained the improvement of the collector efficiency around 10% by using the reflector. Thus, the present solar water heating systems having the best thermal performance compared to the available systems.

High Performance Flat Plate Solar Thermal Collector Evaluation

Energy Technology Data Exchange (ETDEWEB)

Rockenbaugh, Caleb [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dean, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lovullo, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lisell, Lars [National Renewable Energy Lab. (NREL), Golden, CO (United States); Barker, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hanckock, Ed [National Renewable Energy Lab. (NREL), Golden, CO (United States); Norton, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-09-01

This report was prepared for the General Services Administration by the National Renewable Energy Laboratory. The Honeycomb Solar Thermal Collector (HSTC) is a flat plate solar thermal collector that shows promising high efficiencies over a wide range of climate zones. The technical objectives of this study are to: 1) verify collector performance, 2) compare that performance to other market-available collectors, 3) verify overheat protection, and 4) analyze the economic performance of the HSTC both at the demonstration sites and across a matrix of climate zones and utility markets.

Nanocrystalline Silicon Carrier Collectors for Silicon Heterojunction Solar Cells and Impact on Low-Temperature Device Characteristics

KAUST Repository

Nogay, Gizem

2016-09-26

Silicon heterojunction solar cells typically use stacks of hydrogenated intrinsic/doped amorphous silicon layers as carrier selective contacts. However, the use of these layers may cause parasitic optical absorption losses and moderate fill factor (FF) values due to a high contact resistivity. In this study, we show that the replacement of doped amorphous silicon with nanocrystalline silicon is beneficial for device performance. Optically, we observe an improved short-circuit current density when these layers are applied to the front side of the device. Electrically, we observe a lower contact resistivity, as well as higher FF. Importantly, our cell parameter analysis, performed in a temperature range from -100 to +80 °C, reveals that the use of hole-collecting p-type nanocrystalline layer suppresses the carrier transport barrier, maintaining FF s in the range of 70% at -100 °C, whereas it drops to 40% for standard amorphous doped layers. The same analysis also reveals a saturation onset of the open-circuit voltage at -100 °C using doped nanocrystalline layers, compared with saturation onset at -60 °C for doped amorphous layers. These findings hint at a reduced importance of the parasitic Schottky barrier at the interface between the transparent electrodes and the selective contact in the case of nanocrystalline layer implementation. © 2011-2012 IEEE.

Nanocrystalline Silicon Carrier Collectors for Silicon Heterojunction Solar Cells and Impact on Low-Temperature Device Characteristics

KAUST Repository

Nogay, Gizem; Seif, Johannes Peter; Riesen, Yannick; Tomasi, Andrea; Jeangros, Quentin; Wyrsch, Nicolas; Haug, Franz-Josef; De Wolf, Stefaan; Ballif, Christophe

2016-01-01

Silicon heterojunction solar cells typically use stacks of hydrogenated intrinsic/doped amorphous silicon layers as carrier selective contacts. However, the use of these layers may cause parasitic optical absorption losses and moderate fill factor (FF) values due to a high contact resistivity. In this study, we show that the replacement of doped amorphous silicon with nanocrystalline silicon is beneficial for device performance. Optically, we observe an improved short-circuit current density when these layers are applied to the front side of the device. Electrically, we observe a lower contact resistivity, as well as higher FF. Importantly, our cell parameter analysis, performed in a temperature range from -100 to +80 °C, reveals that the use of hole-collecting p-type nanocrystalline layer suppresses the carrier transport barrier, maintaining FF s in the range of 70% at -100 °C, whereas it drops to 40% for standard amorphous doped layers. The same analysis also reveals a saturation onset of the open-circuit voltage at -100 °C using doped nanocrystalline layers, compared with saturation onset at -60 °C for doped amorphous layers. These findings hint at a reduced importance of the parasitic Schottky barrier at the interface between the transparent electrodes and the selective contact in the case of nanocrystalline layer implementation. © 2011-2012 IEEE.

Direct-heating solar-collector dump valve

Science.gov (United States)

Howikman, T. C.

1977-01-01

Five-port ganged valve isolates collector from primary load system pressure and drains collectors, allowing use of direct heating with all its advantages. Valve is opened and closed by same switch that controls pump or by temperature sensor set at O C, while providing direct dump option.

Flat-plate solar collector - installation package

Science.gov (United States)

1978-01-01

Package includes installation, operation and maintenance manual for collector, analysis of safety hazards, special handling instructions, materials list, installation drawings, and warranty and certification statement. Manual includes instructions for roof preparation and for preparing collector for installation. Several pages are devoted to major and minor repairs.

The continuum between Bipolar Disorder and Borderline Personality Disorder.

Science.gov (United States)

Elisei, Sandro; Anastasi, Serena; Verdolini, Norma

2012-09-01

Several studies have been carried out regarding the possible overlap between Bipolar Disorder and borderline personality disorder. Up to now, it is not possible to provide a definitive picture. In fact, there is currently significant debate about the relationship between Borderline Personality Disorder and Bipolar Disorder. MEDLINE searches were performed to identify the latest studies of these disorders, considering psychodynamic aspects. Bipolar disorder and borderline personality disorder share common clinical features, namely affective instability and impulsivity which however differ in quality. Consequently, to better understand these aspects, it is necessary to trace the stages of childhood psychological development. It has been claimed that Bipolar Disorder Type II can be divided into two subtypes: one stable and functional between episodes and one unstable between episodes which is related to Borderline Personality Disorder. However, better diagnostic theories, psychiatrist's empathy and patience remain the essential tool to understand and to face human suffering.

A self-powered nano-photodetector based on PFH/ZnO nanorods organic/inorganic heterojunction

Science.gov (United States)

Li, Xiaoyun; Liu, Wei; Li, Peigang; Song, Jia; An, Yuehua; Shen, Jingqin; Wang, Shunli; Guo, Daoyou

2018-03-01

PFH/ZnO nanorods heterojunctions were fabricated by spin-coating p-type Poly (9,9-dihexylfluorene) (PFH) on n-type vertically aligned ZnO nanorod arrays grown by a facile hydrothermal method on indium tin oxide (ITO) transparent conductive glass. A typical p-n junction behavior was observed in the fabricated heterojunction. The current of heterojunction increases and decreases dramatically by switching the illumination on and off at zero bias, showing potential self-powered photodetector applications. The heterojunction were capable of generating negative current when illuminated under an appropriate wavelength. The photoresponse properties of the heterojunction can be tuned by the applied bias. In vacuum, the rectifying behavior disappeared, and show only simple semiconductor behavior. Band structure of the heterojunction was schematic drawn and explain the mechanism of the properties of PFH/ZnO nanorods heterojunctions.

A self-powered nano-photodetector based on PFH/ZnO nanorods organic/inorganic heterojunction

Directory of Open Access Journals (Sweden)

Xiaoyun Li

2018-03-01

Full Text Available PFH/ZnO nanorods heterojunctions were fabricated by spin-coating p-type Poly (9,9-dihexylfluorene (PFH on n-type vertically aligned ZnO nanorod arrays grown by a facile hydrothermal method on indium tin oxide (ITO transparent conductive glass. A typical p-n junction behavior was observed in the fabricated heterojunction. The current of heterojunction increases and decreases dramatically by switching the illumination on and off at zero bias, showing potential self-powered photodetector applications. The heterojunction were capable of generating negative current when illuminated under an appropriate wavelength. The photoresponse properties of the heterojunction can be tuned by the applied bias. In vacuum, the rectifying behavior disappeared, and show only simple semiconductor behavior. Band structure of the heterojunction was schematic drawn and explain the mechanism of the properties of PFH/ZnO nanorods heterojunctions.

Novel multiple criteria decision making methods based on bipolar neutrosophic sets and bipolar neutrosophic graphs

OpenAIRE

Muhammad, Akram; Musavarah, Sarwar

2016-01-01

In this research study, we introduce the concept of bipolar neutrosophic graphs. We present the dominating and independent sets of bipolar neutrosophic graphs. We describe novel multiple criteria decision making methods based on bipolar neutrosophic sets and bipolar neutrosophic graphs. We also develop an algorithm for computing domination in bipolar neutrosophic graphs.

Morphological Control for High Performance, Solution-Processed Planar Heterojunction Perovskite Solar Cells

KAUST Repository

Eperon, Giles E.

2013-09-09

Organometal trihalide perovskite based solar cells have exhibited the highest efficiencies to-date when incorporated into mesostructured composites. However, thin solid films of a perovskite absorber should be capable of operating at the highest efficiency in a simple planar heterojunction configuration. Here, it is shown that film morphology is a critical issue in planar heterojunction CH3NH3PbI3-xCl x solar cells. The morphology is carefully controlled by varying processing conditions, and it is demonstrated that the highest photocurrents are attainable only with the highest perovskite surface coverages. With optimized solution based film formation, power conversion efficiencies of up to 11.4% are achieved, the first report of efficiencies above 10% in fully thin-film solution processed perovskite solar cells with no mesoporous layer. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficiencies of flat plate solar collectors at different flow rates

DEFF Research Database (Denmark)

Chen, Ziqian; Furbo, Simon; Perers, Bengt

2012-01-01

Two flat plate solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one collector is equipped with an ETFE foil between...... the absorber and the cover glass and the other is without ETFE foil. The efficiencies for the collectors are tested at different flow rates. On the basis of the measured efficiencies, the efficiencies for the collectors as functions of flow rate are obtained. The calculated efficiencies are in good agreement...

Hierarchically Mesostructured Aluminum Current Collector for Enhancing the Performance of Supercapacitors.

Science.gov (United States)

Huang, Yilun; Li, Yuyao; Gong, Qianming; Zhao, Guanlei; Zheng, Pengjie; Bai, Junfei; Gan, Jianning; Zhao, Ming; Shao, Yang; Wang, Dazhi; Liu, Lei; Zou, Guisheng; Zhuang, Daming; Liang, Ji; Zhu, Hongwei; Nan, Cewen

2018-05-16

Aluminum (Al) current collector is one of the most important components of supercapacitors, and its performance has vital effects on the electrochemical performance and cyclic stability of supercapacitors. In the present work, a scalable and low-cost, yet highly efficient, picosecond laser processing method of Al current collectors was developed to improve the overall performance of supercapacitors. The laser treatment resulted in hierarchical micro-nanostructures on the surface of the commercial Al foil and reduced the surface oxygen content of the foil. The electrochemical performance of the Al foil with the micro-nanosurface structures was examined in the symmetrical activated carbon-based coin supercapacitors with an organic electrolyte. The results suggest that the laser-treated Al foil (laser-Al) increased the capacitance density of supercapacitors up to 110.1 F g -1 and promoted the rate capability due to its low contact resistance with the carbonaceous electrode and high electrical conductivity derived from its larger specific surface areas and deoxidized surface. In addition, the capacitor with the laser-Al current collector exhibited high cyclic stability with 91.5% capacitance retention after 10 000 cycles, 21.3% higher than that with pristine-Al current collector due to its stronger bonding with the carbonaceous electrode that prevented any delamination during aging. Our work has provided a new strategy for improving the electrochemical performance of supercapacitors.

Investigation of Impact of the Gate Circuitry on IGBT Transistor Dynamic Parameters

Directory of Open Access Journals (Sweden)

Vytautas Bleizgys

2011-03-01

Full Text Available The impact of Insulated Gate Bipolar Transistor driver circuit parameters on the rise and fall time of the collector current and voltage collector-emitter was investigated. The influence of transistor driver circuit parameters on heating of Insulated Gate Bipolar Transistors was investigated as well.Article in Lithuanian

Quantitative measurement of 222Rn in water by the activated charcoal passive collector method: 1. The effect of water in a collector

International Nuclear Information System (INIS)

Yoneda, Minoru; Inoue, Yoriteru; Yoshimoto, Keizo

1994-01-01

The activated charcoal passive collector method can be applied to measure the concentration of 222 Rn in river water. The 222 Rn collector is composed of dry activated charcoal sealed in a polyethylene bag. However, we found it very difficult to keep activated charcoal in a collector dry during the period the collector was left in a river. The degree of dampness and the time lapsed when activated charcoal became wet were thought to affect the quantity of 222 Rn collected. First, we studied the effect of some parameters in the activated charcoal passive collector method qualitatively in three experiments. We found that the quantity of 222 Rn collected in a collector was not so sensitive to the quantity of activated charcoal in the collector or the thickness of polyethylene film under the condition of wet activated charcoal, and that wet activated charcoal accumulated less 222 Rn than dry activated charcoal. We present some equations which could explain how much 222 Rn was collected in a collector when activated charcoal was submerged directly in water and when activated charcoal was packed in a polyethylene bag but completely wet. These equations were proved effective by being compared with the results of the other experiments. Finally, we recommended some conditions which proved useful when measuring at an actual river

Two new designs of parabolic solar collectors

Directory of Open Access Journals (Sweden)

Karimi Sadaghiyani Omid

2014-01-01

Full Text Available In this work, two new compound parabolic trough and dish solar collectors are presented with their working principles. First, the curves of mirrors are defined and the mathematical formulation as one analytical method is used to trace the sun rays and recognize the focus point. As a result of the ray tracing, the distribution of heat flux around the inner wall can be reached. Next, the heat fluxes are calculated versus several absorption coefficients. These heat flux distributions around absorber tube are functions of angle in polar coordinate system. Considering, the achieved heat flux distribution are used as a thermal boundary condition. After that, Finite Volume Methods (FVM are applied for simulation of absorber tube. The validation of solving method is done by comparing with Dudley's results at Sandia National Research Laboratory. Also, in order to have a good comparison between LS-2 and two new designed collectors, some of their parameters are considered equal with together. These parameters are consist of: the aperture area, the measures of tube geometry, the thermal properties of absorber tube, the working fluid, the solar radiation intensity and the mass flow rate of LS-2 collector are applied for simulation of the new presented collectors. After the validation of the used numerical models, this method is applied to simulation of the new designed models. Finally, the outlet results of new designed collector are compared with LS-2 classic collector. Obviously, the obtained results from the comparison show the improving of the new designed parabolic collectors efficiency. In the best case-study, the improving of efficiency are about 10% and 20% for linear and convoluted models respectively.

Imunologia do transtorno bipolar Immunology of bipolar disorder

Directory of Open Access Journals (Sweden)

Izabela Guimarães Barbosa

2009-01-01

Full Text Available 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. As bases de dados avaliadas foram MedLine e Scopus, entre os anos de 1980 e 2008. RESULTADOS: Foram identificados 28 trabalhos que estudaram alterações imunes em pacientes com transtorno bipolar. Seis artigos investigaram genes relacionados à resposta imune; cinco, autoanticorpos; quatro, populações leucocitárias; 13, citocinas e/ou moléculas relacionadas à resposta imune e seis, leucócitos de pacientes in vitro. CONCLUSÕES: Embora haja evidências na literatura correlacionando o transtorno bipolar a alterações imunes, os dados não são conclusivos. O transtorno bipolar parece estar associado a níveis mais elevados de autoanticorpos circulantes, assim como à tendência à ativação imune com produção de citocinas pró-inflamatórias e redução de parâmetros anti-inflamatórios.OBJECTIVE: Emerging research has implicated immune factors in the pathogenesis of a variety of neuropsychiatric disorders. The objective of the present paper is to review the studies that investigated the association between bipolar disorder and immune parameters. METHODS: Papers that included the keywords "bipolar to disorder", "mania", "immunology", "cytokines", "chemokines", "interleukins", "interferon" and "tumor necrosis factor" were selected in a systematic review of the literature. The evaluated databases were MedLine and Scopus in the period between 1980 and 2008. RESULTS: Twenty eight works were found. Six studies investigated immune response

Performance of non-conventional solar collectors in local market of Nawabshah

International Nuclear Information System (INIS)

Memon, M.; Tanwani, N.K.; Memon, A.H.

1998-01-01

This paper presents experimental studies concerning the performance of solar collectors using sand-bed as absorbing surface and a collector. These collectors were designed, manufactured locally and tested in meteorological conditions of Nawabshah, Sindh, Pakistan. The ordinary tap water was used as working fluid and tests were carried out in open space during day time. The effect of collector area and tubing diameter on collector performance was investigated. For each test run ambient, inlet and outlet water temperature together with flow rate of collector fluid was recorded. Two collectors connected in series showed an increase of about 20 deg. C in outlet temperature of water. Thus an average increase of 15 deg. C in the temperature was observed for each collector. The temperature was raised to 90 deg. C using the concentrator in combination with the two non-conventional flat collectors. (author)

Arrangement, manufacturing process and use of solar heat collectors

Energy Technology Data Exchange (ETDEWEB)

Scheel, H W

1978-03-30

Solar collectors generally have a timber or metal frame where the transparent front cover, usually of glass, is replaceable. In order to prevent great deformation, such a frame must be relatively stable and of heavy construction, which may lead to difficulties in mounting the collector on the roofs or front walls of houses. The present invention proposes a light but nevertheless rigid collector frame, which consists of plastic material and is constructed so that the installation and replacement of collectors can be realized. Further, collectors are proposed which guarantee a minimum of reflection and are so designed that an optimum architectural effect is produced.

Electro-optical modeling of bulk heterojunction solar cells

Science.gov (United States)

Kirchartz, Thomas; Pieters, Bart E.; Taretto, Kurt; Rau, Uwe

2008-11-01

We introduce a model for charge separation in bulk heterojunction solar cells that combines exciton transport to the interface between donor and acceptor phases with the dissociation of the bound electron/hole pair. We implement this model into a standard semiconductor device simulator, thereby creating a convenient method to simulate the optical and electrical characteristics of a bulk heterojunction solar cell with a commercially available program. By taking into account different collection probabilities for the excitons in the polymer and the fullerene, we are able to reproduce absorptance, internal and external quantum efficiency, as well as current/voltage curves of bulk heterojunction solar cells. We further investigate the influence of mobilities of the free excitons as well as the mobilities of the free charge carriers on the performance of bulk heterojunction solar cells. We find that, in general, the highest efficiencies are achieved with the highest mobilities. However, an optimum finite mobility of free charge carriers can result from a large recombination velocity at the contacts. In contrast, Langevin-type of recombination cannot lead to finite optimum mobilities even though this mechanism has a strong dependence on the free carrier mobilities.

Genetic structure of personality factors and bipolar disorder in families segregating bipolar disorder.

Science.gov (United States)

Hare, Elizabeth; Contreras, Javier; Raventos, Henriette; Flores, Deborah; Jerez, Alvaro; Nicolini, Humberto; Ontiveros, Alfonso; Almasy, Laura; Escamilla, Michael

2012-02-01

Bipolar disorder (BPD) has been associated with variations in personality dimensions, but the nature of this relationship has been unclear. In this study, the heritabilities of BPD and the Big Five personality factors and the genetic correlations between BPD and personality factors are reported. The participants in this study were 1073 individuals from 172 families of Mexican or Central American ancestry. Heritabilities and genetic correlations were calculated under a polygenic model using the maximum-likelihood method of obtaining variance components implemented in the SOLAR software package. Heritabilities of 0.49, 0.43, and 0.43 were found for the narrowest phenotype (schizoaffective bipolar and bipolar I), the intermediate phenotype (schizoaffective bipolar, bipolar I, and bipolar II), and the broadest phenotype (schizoaffective bipolar, bipolar I, bipolar II, and recurrent depression), respectively. For the Big Five personality factors, heritabilities were 0.25 for agreeableness, 0.24 for conscientiousness, 0.24 for extraversion, 0.23 for neuroticism, and 0.32 for openness to experience. For the narrowest phenotype, a significant negative correlation (-0.32) with extraversion was found. For the broadest phenotype, negative correlations were found for agreeableness (-0.35), conscientiousness (-0.39), and extraversion (-0.44). A positive correlation (0.37) was found with neuroticism. It is not possible to determine whether aspects of personality are factors in the development of bipolar disorder or vice versa. The short form of the NEO does not provide the ability to examine in detail which facets of extraversion are most closely related to bipolar disorder or to compare our results with studies that have used the long version of the scale. This study establishes a partial genetic basis for the Big Five personality factors in this set of families, while the environmental variances demonstrate that non-genetic factors are also important in their influence on

Cheap effective thermal solar-energy collectors

Energy Technology Data Exchange (ETDEWEB)

Highgate, D.J.; Probert, S.D. [Cranfield University, Bedford (United Kingdom). Dept. of Applied Energy

1996-04-01

A light-weight flexible solar-collector, with a wavelength-selective absorption surface and an insolation-transparent thermal-insulation protecter for its aperture, was built and tested. Its cheapness and high performance, relative to a conventional flat-plate solar-collector, provide a prima-facie case for the more widespread adoption of its design. (author)

INVESTIGATION OF PROPERTIES OF CURRENT COLLECTOR ELEMENTS AND THEIR EFFECT ON THE PERFORMANCE OF TRIBOSYSTEM «CONTACT WIRE - CURRENT COLLECTOR ELEMENT»

Directory of Open Access Journals (Sweden)

Yu. L. Bolshakov

2015-11-01

Full Text Available Purpose. The paper is devoted to the detailed analysis of interrelations at the contact point of friction pair «contact wire – current collector insert». In the work it is necessary: 1 to examine quality of manufacturing of specimens of current collector elements from different manufacturers; 2 to narrow the range of hardness for carbon inserts; 3 to develop a technique of sorting carbon current collector inserts for the structural parameters. Methodology. The executed work was based on the use of the theory of reliability of technical systems and electromechanical processes. Findings. The paper studies the interrelation at the contact point of friction pair «contact wire – current col lector insert», the connection was established between the hardness and electrical resistivity. It is proposed to narrow the range of carbon inserts hardness. The method of sorting coal collector inserts in hardness was developed, and the research has revealed the discrepancy of current collector inserts with existing regulations. It was proposed to equip the pantographs slide with current collector elements using special scheme and to develop a specialized research facility, which will be possible to conduct studies of the interaction of the friction pair «contact wire – current collector insert». Originality. In the course of the study the current collector inserts the sharp structural heterogeneity and fluctuations of the density of the material along the length of the insert were established. The dependence between hardness of inserts and electrical resistivity was established. It was analyzed and concluded about the need to reduce the values of the normal range of hardness. Based on the results of the research, the experimental dependences were obtained and proposed the method for sorting carbon current collector inserts for the structural parameters. Practical value. The obtained results of coal current collector inserts define the need to use

Room temperature synthesis and photocatalytic property of AgO/Ag2Mo2O7 heterojunction nanowires

International Nuclear Information System (INIS)

Hashim, Muhammad; Hu, Chenguo; Wang, Xue; Wan, Buyong; Xu, Jing

2012-01-01

Graphical abstract: The AgO nanoparticles are attached on the surface of the Ag 2 Mo 2 O 7 nanowires to form a heterojunction structure. The AgO nanoparticles start embedding into the nanowires with increasing reaction temperature or time. Highlights: ► AgO/Ag 2 Mo 2 O 7 heterojunction NWs were synthesized at room temperature for the first time. ► AgO particles embed into the Ag 2 Mo 2 O 7 NWs with increase in reaction time and temperature. ► The heterojunction NWs display much better photocatalytic activity than the none-heterojunction NWs. ► The catalytic mechanism was proposed. -- Abstract: AgO/Ag 2 Mo 2 O 7 heterojunction nanowires were synthesized at temperatures of 25 °C, 50 °C, 80 °C, and 110 °C, under magnetic stirring in solution reaction. The catalytic activity of AgO/Ag 2 Mo 2 O 7 nanowires was evaluated by the degradation of Rhodmine B dye under the irradiation of the simulated sunlight. The synthesized samples were characterized by X-ray diffractometer, energy dispersive spectrometry, X-ray photoelectron spectrometer, scanning electron microscopy, and transmission electron microscopy. The results show that the AgO nanoparticles are attached on the surface of the Ag 2 Mo 2 O 7 nanowires to form a heterojunction structure. The length of the nanowires is up to 10 μm and the size of the AgO nanoparticles is 10–20 nm. The length of nanowires increases with increasing reaction time and temperature while the AgO particles are gradually embedded into the nanowires. The photocatalytic activity is greatly improved for the AgO/Ag 2 Mo 2 O 7 heterojunction nanowires compared with that of the pure Ag 2 Mo 2 O 7 nanowires, indicating a remarkable role of AgO particles on the Ag 2 Mo 2 O 7 nanowires in the photodegradation.

Nutrition and Bipolar Depression.

Science.gov (United States)

Beyer, John L; Payne, Martha E

2016-03-01

As with physical conditions, bipolar disorder is likely to be impacted by diet and nutrition. Patients with bipolar disorder have been noted to have relatively unhealthy diets, which may in part be the reason they also have an elevated risk of metabolic syndrome and obesity. An improvement in the quality of the diet should improve a bipolar patient's overall health risk profile, but it may also improve their psychiatric outcomes. New insights into biological dysfunctions that may be present in bipolar disorder have presented new theoretic frameworks for understanding the relationship between diet and bipolar disorder. Copyright © 2016 Elsevier Inc. All rights reserved.

Engineering design of 500KW CW collector

International Nuclear Information System (INIS)

Kumar, Ramesh; Mishra, Deepak; Prasad, M.; Hannuarakar, P.R.

2006-01-01

An electron beam collector for 500kW beam power has been designed to test the electron gun. The gun is designed for 250kW, 350MHz CW Klystron with 50% efficiency. This will also help in preliminary studies related to final collector design for Klystron. This paper presents the design parameters, thermal analysis and mechanical features of the design. Electron trajectory on inside wall of the collector is determined with EGUN and computational flow dynamics simulation was done on ANSYS for cooling requirements. (author)

A tool for standardized collector performance calculations including PVT

DEFF Research Database (Denmark)

Perers, Bengt; Kovacs, Peter; Olsson, Marcus

2012-01-01

A tool for standardized calculation of solar collector performance has been developed in cooperation between SP Technical Research Institute of Sweden, DTU Denmark and SERC Dalarna University. The tool is designed to calculate the annual performance of solar collectors at representative locations...... can be tested and modeled as a thermal collector, when the PV electric part is active with an MPP tracker in operation. The thermal collector parameters from this operation mode are used for the PVT calculations....

Applied research on 2-6 compound materials for heterojunction solar cells

Science.gov (United States)

Bube, R. H.

1975-01-01

Several II-VI heterojunctions show promise for photovoltaic conversion of solar energy. The three of greatest interest are p-CdTe/n-CdS, p-CdTe/n-ZnSe, and p-ZnTe/n-CdSe. Several p-CdTe/n-CdS heterojunction cells have been prepared by close spaced transport deposition of p-CdTe on single crystal n-CdS, and by two source vacuum evaporation of n-CdS on single crystal p-CdTe. Both types of cells, in an experimental stage, are quite comparable, exhibiting values of quantum efficiency between 0.5 and 0.9, open circuit voltages between 0.50 and 0.66 V, fill factors between 0.4 and 0.6, and solar efficiencies up to 4 percent. Cells of p-ZnTe/n-CdSe have also been made by close spaced vapor transport deposition of n-CdSe on single crystal p-ZnTe.

Experience with building integrated solar collectors; Erfaring med bygningsintegrerte solfangere

Energy Technology Data Exchange (ETDEWEB)

Simonsen, Ingeborg; Time, Berit; Andresen, Inger

2011-07-01

The main objective of the research 'Zero Emission Buildings' ZEB is to develop products and solutions that provide buildings with zero greenhouse gas emissions associated with the production, operation and disposal. Can we make this happen must the building produce more energy than it needs to compensate for greenhouse gas emissions from the production of materials and the actual construction.To build up knowledge on experience with building integrated solar collectors in Norway, we have in this study made interviews with suppliers and manufacturers of solar collectors and some building owners. Since the focus is on climate shell, we have limited the study to include solar collectors to replace a part of the cladding or roofing. Construction upstairs roofing, outside facade or freestanding rack is not considered as building integrated in this context. The providers we have been in contact with appeals to slightly different parts of the market. This is reflected in the product's development, assembly and approach to the calculation of energy delivery. Overall, providers may offer a range of products suitable for both the professional and skilled carpenter, the interested 'man in the street' . The feedback we have received shows generally good experiences with the product and the installation. Because of the preliminary short operating periods of the investigated plants we have little data on energy supply from these plants. In summary, we can say that the knowledge and the products are available and it is up to use to use them.(Author)

Chronic obstructive pulmonary disease associated with increased risk of bipolar disorder.

Science.gov (United States)

Su, Vincent Yi-Fong; Hu, Li-Yu; Yeh, Chiu-Mei; Chiang, Huey-Ling; Shen, Cheng-Che; Chou, Kun-Ta; Chen, Tzeng-Ji; Lu, Ti; Tzeng, Cheng-Hwai; Liu, Chia-Jen

2017-05-01

Epidemiological studies have identified a trend in the development of depressive and anxiety disorders following a diagnosis of chronic obstructive pulmonary disease (COPD). However, the relationship between COPD and subsequent bipolar disorder remains unclear. From January 1, 2000, we identified adult patients with COPD from the Taiwan National Health Insurance Research Database. A nationwide population-based study was conducted; 46,778 COPD patients and 46,778 age-, sex-, and comorbidity-matched subjects between 2000 and 2011 were enrolled. The two cohorts were followed up till December 31, 2011 and observed for occurrence of bipolar disorder. We observed the COPD and comparison cohorts for 263,020 and 267,895 person-years, respectively, from 2000 to 2011. The incidence rate for bipolar disorder was 1.6/1000 person-years in the COPD cohort and 1.2/1000 person-years in the comparison cohort ( p bipolar disorder among the COPD patients was 1.42 (95% confidence interval [CI], 1.22-1.64; p bipolar disorder development (HR = 1.83, 95% CI = 1.25-2.69, p = 0.002). Other COPD medications were not associated with the risk of bipolar disorder development. The study results indicate that COPD may be an independent risk factor for the development of bipolar disorder. The regular use of SABAs might increase the risk of bipolar disorder in COPD patients.

High-gain bipolar detector on float-zone silicon

Science.gov (United States)

Han, D. J.; Batignani, G.; Del Guerra, A.; Dalla Betta, G.-F.; Boscardin, M.; Bosisio, L.; Giorgi, M.; Forti, F.

2003-10-01

Since the float-zone (FZ) silicon has lower contaminations and longer minority-carrier lifetime than those in Czochralski silicon and other semiconductor materials, it has potential advantages to fabricate bipolar detectors on the high-purity FZ silicon substrate to achieve a high gain at ultra-low-signal levels. The authors present preliminary experimental results on a bipolar detector fabricated on an unusual high-purity FZ silicon substrate. A backside gettering layer of phosphorus-doped polysilicon was employed to preserve the long carrier lifetime of the high-purity FZ silicon. The device has been investigated in the detection of a continuous flux of X-ray and infrared light. The bipolar detector with a circular emitter of 2 mm diameter has demonstrated high gains up to 3820 for 22 keV X-ray from a 1 mCi Cd radioactive source (the X-ray photon flux, received by the detector is estimated to be ˜7.77×10 4/s). High gain up to 4400 for 0.17 nW light with a wavelength of 0.83 μm has been observed for the same device.

High-gain bipolar detector on float-zone silicon

International Nuclear Information System (INIS)

Han, D.J.; Batignani, G.; Guerra, A.D.A. Del; Dalla Betta, G.-F.; Boscardin, M.; Bosisio, L.; Giorgi, M.; Forti, F.

2003-01-01

Since the float-zone (FZ) silicon has lower contaminations and longer minority-carrier lifetime than those in Czochralski silicon and other semiconductor materials, it has potential advantages to fabricate bipolar detectors on the high-purity FZ silicon substrate to achieve a high gain at ultra-low-signal levels. The authors present preliminary experimental results on a bipolar detector fabricated on an unusual high-purity FZ silicon substrate. A backside gettering layer of phosphorus-doped polysilicon was employed to preserve the long carrier lifetime of the high-purity FZ silicon. The device has been investigated in the detection of a continuous flux of X-ray and infrared light. The bipolar detector with a circular emitter of 2 mm diameter has demonstrated high gains up to 3820 for 22 keV X-ray from a 1 mCi Cd radioactive source (the X-ray photon flux, received by the detector is estimated to be ∼7.77x10 4 /s). High gain up to 4400 for 0.17 nW light with a wavelength of 0.83 μm has been observed for the same device

FLOW DISTRIBUTION IN A SOLAR COLLECTOR PANEL WITH HORIZONTAL ABSORBER STRIPS

DEFF Research Database (Denmark)

Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

2007-01-01

The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontal strips. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid dynamics...... (CFD) calculations. Further, experimental investigations of a 12.5 m² solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured...... collector fluid, and by increased collector tilt and inlet temperature, the flow distribution gets worse resulting in a decreased collector efficiency and an increased risk of boiling in the upper part of the collector panel. Keywords: Solar collector; Flow distribution; Computational Fluid Dynamics (CFD...

Fabrication of Si/ZnS radial nanowire heterojunction arrays for white light emitting devices on Si substrates.

Science.gov (United States)

Katiyar, Ajit K; Sinha, Arun Kumar; Manna, Santanu; Ray, Samit K

2014-09-10

Well-separated Si/ZnS radial nanowire heterojunction-based light-emitting devices have been fabricated on large-area substrates by depositing n-ZnS film on p-type nanoporous Si nanowire templates. Vertically oriented porous Si nanowires on p-Si substrates have been grown by metal-assisted chemical etching catalyzed using Au nanoparticles. Isolated Si nanowires with needle-shaped arrays have been made by KOH treatment before ZnS deposition. Electrically driven efficient white light emission from radial heterojunction arrays has been achieved under a low forward bias condition. The observed white light emission is attributed to blue and green emission from the defect-related radiative transition of ZnS and Si/ZnS interface, respectively, while the red arises from the porous surface of the Si nanowire core. The observed white light emission from the Si/ZnS nanowire heterojunction could open up the new possibility to integrate Si-based optical sources on a large scale.

Heat Pumps With Direct Expansion Solar Collectors

Science.gov (United States)

Ito, Sadasuke

In this paper, the studies of heat pump systems using solar collectors as the evaporators, which have been done so far by reserchers, are reviwed. Usually, a solar collector without any cover is preferable to one with ac over because of the necessity of absorbing heat from the ambient air when the intensity of the solar energy on the collector is not enough. The performance of the collector depends on its area and the intensity of the convective heat transfer on the surface. Fins are fixed on the backside of the collector-surface or on the tube in which the refrigerant flows in order to increase the convective heat transfer. For the purpose of using a heat pump efficiently throughout year, a compressor with variable capacity is applied. The solar assisted heat pump can be used for air conditioning at night during the summer. Only a few groups of people have studied cooling by using solar assisted heat pump systems. In Japan, a kind of system for hot water supply has been produced commercially in a company and a kind of system for air conditioning has been installed in buildings commercially by another company.

PERFORMANCE EVALUATION OF SOLAR COLLECTORS USING A SOLAR SIMULATOR

OpenAIRE

M. Norhafana; Ahmad Faris Ismail; Z. A. A. Majid

2015-01-01

Solar water heating systems is one of the applications of solar energy. One of the components of a solar water heating system is a solar collector that consists of an absorber. The performance of the solar water heating system depends on the absorber in the solar collector. In countries with unsuitable weather conditions, the indoor testing of solar collectors with the use of a solar simulator is preferred. Thus, this study is conducted to use a multilayered absorber in the solar collector of...

Properties of Bipolar Fuzzy Hypergraphs

OpenAIRE

Akram, M.; Dudek, W. A.; Sarwar, S.

2013-01-01

In this article, we apply the concept of bipolar fuzzy sets to hypergraphs and investigate some properties of bipolar fuzzy hypergraphs. We introduce the notion of $A-$ tempered bipolar fuzzy hypergraphs and present some of their properties. We also present application examples of bipolar fuzzy hypergraphs.

Ultrafast Exciton Dissociation and Long-Lived Charge Separation in a Photovoltaic Pentacene-MoS2 van der Waals Heterojunction.

Science.gov (United States)

Bettis Homan, Stephanie; Sangwan, Vinod K; Balla, Itamar; Bergeron, Hadallia; Weiss, Emily A; Hersam, Mark C

2017-01-11

van der Waals heterojunctions between two-dimensional (2D) layered materials and nanomaterials of different dimensions present unique opportunities for gate-tunable optoelectronic devices. Mixed-dimensional p-n heterojunction diodes, such as p-type pentacene (0D) and n-type monolayer MoS 2 (2D), are especially interesting for photovoltaic applications where the absorption cross-section and charge transfer processes can be tailored by rational selection from the vast library of organic molecules and 2D materials. Here, we study the kinetics of excited carriers in pentacene-MoS 2 p-n type-II heterojunctions by transient absorption spectroscopy. These measurements show that the dissociation of MoS 2 excitons occurs by hole transfer to pentacene on the time scale of 6.7 ps. In addition, the charge-separated state lives for 5.1 ns, up to an order of magnitude longer than the recombination lifetimes from previously reported 2D material heterojunctions. By studying the fractional amplitudes of the MoS 2 decay processes, the hole transfer yield from MoS 2 to pentacene is found to be ∼50%, with the remaining holes undergoing trapping due to surface defects. Overall, the ultrafast charge transfer and long-lived charge-separated state in pentacene-MoS 2 p-n heterojunctions suggest significant promise for mixed-dimensional van der Waals heterostructures in photovoltaics, photodetectors, and related optoelectronic technologies.

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.

Two-axis movable concentrating solar energy collector

Science.gov (United States)

Perkins, G. S.

1977-01-01

Proposed solar-tracker collector assembly with boiler in fixed position, allows use of hard line connections, capable of withstanding optimum high temperature fluid flow. System thereby eliminates need for flexible or slip connection previously used with solar collector systems.

The performance of solar collector CPC (compound parabolic concentrator) type with three pipes covered by glass tubes

Science.gov (United States)

Gaos, Yogi Sirodz; Yulianto, Muhamad; Juarsa, Mulya; Nurrohman, Marzuki, Edi; Yuliaji, Dwi; Budiono, Kabul

2017-03-01

Indonesia is a tropical country that has potential energy of solar radiation worth of 4.5 until 4.8 kWh/m2. However, this potential has not been utilized regularly. This paper will discuss the performance of solar collector compound parabolic concentrator (CPC) type with water as the working fluid. This CPC solar collector utilized three pipes covered by glass tubes. This paper has contribution to provide the temperature achievement between three pipes covered by glass tubes with and without glass cover of solar collector CPC type. The research conducted by varying the water flow rate of 1 l/m up to 6 l/m with three pipes arranged in series and parallel. From the results, the used of solar collector CPC type in the current study shows that the decrease of solar radiation, which was caused by climate change, did not influence the heat absorbance by water in the pipe. Therefore, the design of the solar collector in this research has potential to be used in future when solar radiation are used as the energy source.

Understanding the failure mechanisms of microwave bipolar transistors caused by electrostatic discharge

Science.gov (United States)

Jin, Liu; Yongguang, Chen; Zhiliang, Tan; Jie, Yang; Xijun, Zhang; Zhenxing, Wang

2011-10-01

Electrostatic discharge (ESD) phenomena involve both electrical and thermal effects, and a direct electrostatic discharge to an electronic device is one of the most severe threats to component reliability. Therefore, the electrical and thermal stability of multifinger microwave bipolar transistors (BJTs) under ESD conditions has been investigated theoretically and experimentally. 100 samples have been tested for multiple pulses until a failure occurred. Meanwhile, the distributions of electric field, current density and lattice temperature have also been analyzed by use of the two-dimensional device simulation tool Medici. There is a good agreement between the simulated results and failure analysis. In the case of a thermal couple, the avalanche current distribution in the fingers is in general spatially unstable and results in the formation of current crowding effects and crystal defects. The experimental results indicate that a collector-base junction is more sensitive to ESD than an emitter-base junction based on the special device structure. When the ESD level increased to 1.3 kV, the collector-base junction has been burnt out first. The analysis has also demonstrated that ESD failures occur generally by upsetting the breakdown voltage of the dielectric or overheating of the aluminum-silicon eutectic. In addition, fatigue phenomena are observed during ESD testing, with devices that still function after repeated low-intensity ESDs but whose performances have been severely degraded.

Topological insulator nanowires and nanowire hetero-junctions

Science.gov (United States)

Deng, Haiming; Zhao, Lukas; Wade, Travis; Konczykowski, Marcin; Krusin-Elbaum, Lia

2014-03-01

The existing topological insulator materials (TIs) continue to present a number of challenges to complete understanding of the physics of topological spin-helical Dirac surface conduction channels, owing to a relatively large charge conduction in the bulk. One way to reduce the bulk contribution and to increase surface-to-volume ratio is by nanostructuring. Here we report on the synthesis and characterization of Sb2Te3, Bi2Te3 nanowires and nanotubes and Sb2Te3/Bi2Te3 heterojunctions electrochemically grown in porous anodic aluminum oxide (AAO) membranes with varied (from 50 to 150 nm) pore diameters. Stoichiometric rigid polycrystalline nanowires with controllable cross-sections were obtained using cell voltages in the 30 - 150 mV range. Transport measurements in up to 14 T magnetic fields applied along the nanowires show Aharonov-Bohm (A-B) quantum oscillations with periods corresponding to the nanowire diameters. All nanowires were found to exhibit sharp weak anti-localization (WAL) cusps, a characteristic signature of TIs. In addition to A-B oscillations, new quantization plateaus in magnetoresistance (MR) at low fields (< 0 . 7T) were observed. The analysis of MR as well as I - V characteristics of heterojunctions will be presented. Supported in part by NSF-DMR-1122594, NSF-DMR-1312483-MWN, and DOD-W911NF-13-1-0159.

Installation package for concentrating solar collector panels

Science.gov (United States)

1978-01-01

The concentrating solar collector panels comprise a complete package array consisting of collector panels using modified Fresnel prismatic lenses for a 10 to 1 concentrating ratio, supporting framework, fluid manifolding and tracking drive system, and unassembled components for field erection.

Advances in design of air-heating collectors

CSIR Research Space (South Africa)

Johannsen, A

1982-11-01

Full Text Available Principles of the operation of air-heating collectors are discussed. The fundamental differences between the design principles of air-heating as opposed to water-heating collectors are highlighted. The main requirement is the transfer of heat from...

Carbon dioxide induces erratic respiratory responses in bipolar disorder.

Science.gov (United States)

Mackinnon, Dean F; Craighead, Brandie; Lorenz, Laura

2009-01-01

CO(2) respiration stimulates both anxiety and dyspnea ("air hunger") and has long been used to study panic vulnerability and respiratory control. High comorbidity with panic attacks suggests individuals with bipolar disorder may also mount a heightened anxiety response to CO(2). Moreover, problems in the arousal and modulation of appetites are central to the clinical syndromes of mania and depression; hence CO(2) may arouse an abnormal respiratory response to "air hunger". 72 individuals (34 bipolar I, 25 depressive and bipolar spectrum, 13 with no major affective diagnosis) breathed air and air with 5% CO(2) via facemask for up to 15 min each; subjective and respiratory responses were recorded. Nearly half the subjects diverged from the typical response to a fixed, mildly hypercapneic environment, which is to increase breathing acutely, and then maintain a hyperpneic plateau. The best predictors of an abnormal pattern were bipolar diagnosis and anxiety from air alone. 25 individuals had a panic response; panic responses from CO(2) were more likely in subjects with bipolar I compared to other subjects, however the best predictors of a panic response overall were anxiety from air alone and prior history of panic attacks. Heterogeneous sample, liberal definition of panic attack. Carbon dioxide produces abnormal respiratory and heightened anxiety responses among individuals with bipolar and depressive disorders. These may be due to deficits in emotional conditioning related to fear and appetite. Although preliminary, this work suggests a potentially useful test of a specific functional deficit in bipolar disorder.

Doped Heterojunction Used in Quantum Dot Sensitized Solar Cell

Directory of Open Access Journals (Sweden)

Yanyan Gao

2014-01-01

Full Text Available Incorporated foreign atoms into the quantum dots (QDs used in heterojunction have always been a challenge for solar energy conversion. A foreign atom indium atom was incorporated into PbS/CdS QDs to prepare In-PbS/In-CdS heterojunction by successive ionic layer adsorption and reaction method which is a chemical method. Experimental results indicate that PbS or CdS has been doped with In by SILAR method; the concentration of PbS and CdS which was doped In atoms has no significantly increase or decrease. In addition, incorporating of Indium atoms has resulted in the lattice distortions or changes of PbS or CdS and improved the light harvest of heterojunction. Using this heterojunction, Pt counter electrode and polysulfide electrolyte, to fabricate quantum dot sensitized solar cells, the short circuit current density ballooned to 27.01 mA/cm2 from 13.61 mA/cm2 and the open circuit voltage was improved to 0.43 V from 0.37 V at the same time.

Attention-deficit hyperactivity disorder and anxiety disorders as precursors of bipolar disorder onset in adulthood

DEFF Research Database (Denmark)

Meier, Sandra M; Pavlova, Barbara; Dalsgaard, Søren

2018-01-01

BACKGROUND: Attention-deficit hyperactivity disorder (ADHD) and anxiety disorders have been proposed as precursors of bipolar disorder, but their joint and relative roles in the development of bipolar disorder are unknown.AimsTo test the prospective relationship of ADHD and anxiety with onset...... of bipolar disorder. METHOD: We examined the relationship between ADHD, anxiety disorders and bipolar disorder in a birth cohort of 2 409 236 individuals born in Denmark between 1955 and 1991. Individuals were followed from their sixteenth birthday or from January 1995 to their first clinical contact...... for bipolar disorder or until December 2012. We calculated incidence rates per 10 000 person-years and tested the effects of prior diagnoses on the risk of bipolar disorder in survival models. RESULTS: Over 37 394 865 person-years follow-up, 9250 onsets of bipolar disorder occurred. The incidence rate...

Selective flotation of phosphate minerals with hydroxamate collectors

Science.gov (United States)

Miller, Jan D.; Wang, Xuming; Li, Minhua

2002-01-01

A method is disclosed for separating phosphate minerals from a mineral mixture, particularly from high-dolomite containing phosphate ores. The method involves conditioning the mineral mixture by contacting in an aqueous in environment with a collector in an amount sufficient for promoting flotation of phosphate minerals. The collector is a hydroxamate compound of the formula; ##STR1## wherein R is generally hydrophobic and chosen such that the collector has solubility or dispersion properties it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms. M is a cation, typically hydrogen, an alkali metal or an alkaline earth metal. Preferably, the collector also comprises an alcohol of the formula, R'--OH wherein R' is generally hydrophobic and chosen such that the collector has solubility or dispersion properties so that it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms.

Bipolar Disorder in Children

Science.gov (United States)

2014-01-01

Although bipolar disorder historically was thought to only occur rarely in children and adolescents, there has been a significant increase in children and adolescents who are receiving this diagnosis more recently (Carlson, 2005). Nonetheless, the applicability of the current bipolar disorder diagnostic criteria for children, particularly preschool children, remains unclear, even though much work has been focused on this area. As a result, more work needs to be done to further the understanding of bipolar symptoms in children. It is hoped that this paper can assist psychologists and other health service providers in gleaning a snapshot of the literature in this area so that they can gain an understanding of the diagnostic criteria and other behaviors that may be relevant and be informed about potential approaches for assessment and treatment with children who meet bipolar disorder criteria. First, the history of bipolar symptoms and current diagnostic criteria will be discussed. Next, assessment strategies that may prove helpful for identifying bipolar disorder will be discussed. Then, treatments that may have relevance to children and their families will be discussed. Finally, conclusions regarding work with children who may have a bipolar disorder diagnosis will be offered. PMID:24800202

Generation of metal composition gradients by means of bipolar electrodeposition

International Nuclear Information System (INIS)

Tisserant, Gwendoline; Fattah, Zahra; Ayela, Cédric; Roche, Jérome; Plano, Bernard; Zigah, Dodzi; Goudeau, Bertrand; Kuhn, Alexander; Bouffier, Laurent

2015-01-01

Highlights: • A bipolar electrochemistry approach for the preparation of surface gradients is reported. • Several metals are simultaneously deposited on a bipolar electrode. • The elemental composition and thickness of the deposit varies alongside the bipolar electrode. • The deposit affects the surface properties and exhibits a barcode feature. - Abstract: Bipolar electrochemistry is an unconventional technique that currently encounters a renewal of interest due to modern applications in the fields of analytical chemistry or materials science. The approach is particularly relevant for the preparation of asymmetric objects or surfaces such as Janus particles for example. Bipolar electrochemistry allows spatially controlled deposition of various layers from electroactive precursors, selectively at one side of a bipolar electrode. We report here the concomitant cathodic deposition of up to three different metals at the same time in a single experiment. The deposits were characterized by optical and electron microscopy imaging as well as profilometry and energy dispersive X-ray spectroscopy. As a result, the deposited layer is composed of several areas exhibiting both a composition and a thickness gradient. Such a variation directly modifies the optical and electronic properties alongside the surface and gives access to the design of composite surfaces exhibiting a visual gradient feature.

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...

Electroluminescence from GaN-polymer heterojunction

International Nuclear Information System (INIS)

Chitara, Basant; Lal, Nidhi; Krupanidhi, S.B.; Rao, C.N.R.

2011-01-01

Inorganic and organic semiconductor devices are generally viewed as distinct and separate technologies. Herein we report a hybrid inorganic-organic light-emitting device employing the use of an air stable polymer, Poly (9,9-dioctylfluorene-alt-benzothiadiazole) as a p-type layer to create a heterojunction, avoiding the use of p-type GaN, which is difficult to grow, being prone to the complex and expensive fabrication techniques that characterises it. I-V characteristics of the GaN-polymer heterojunction fabricated by us exhibits excellent rectification. The luminescence onset voltage is typically about 8-10 V. The device emits yellowish white electroluminescence with CIE coordinates (0.42, 0.44). - Highlights: → We use a polymer Poly (9,9-dioctylfluorene-alt-benzothiadiazole) as a p-type layer to create a heterojunction. → I-V characteristics of the device fabricated by us exhibits excellent rectification. → The p-type polymer also emits yellow light, which when combined in proper composition with GaN, give rise to white light. → Device can be readily fabricated by just spin coating the polymer over GaN reducing the cost of the device.

Analysis of a solar collector field water flow network

Science.gov (United States)

Rohde, J. E.; Knoll, R. H.

1976-01-01

A number of methods are presented for minimizing the water flow variation in the solar collector field for the Solar Building Test Facility at the Langley Research Center. The solar collector field investigated consisted of collector panels connected in parallel between inlet and exit collector manifolds to form 12 rows. The rows were in turn connected in parallel between the main inlet and exit field manifolds to complete the field. The various solutions considered included various size manifolds, manifold area change, different locations for the inlets and exits to the manifolds, and orifices or flow control valves. Calculations showed that flow variations of less than 5 percent were obtainable both inside a row between solar collector panels and between various rows.

Early-Onset Bipolar Disorder: Characteristics and Outcomes in the Clinic.

Science.gov (United States)

Connor, Daniel F; Ford, Julian D; Pearson, Geraldine S; Scranton, Victoria L; Dusad, Asha

2017-12-01

important. Given high rates of high-risk behaviors in these youth, regular mental health follow-up to assess safety is important. Additional evidence-based treatments for pediatric bipolar disorder are needed.

Flat solar collector an approach to its evaluation

Energy Technology Data Exchange (ETDEWEB)

Sonino, T [Israel Atomic Energy Commission, Yavne. Soreq Nuclear Research Center

1977-01-01

The flat solar collector is the most widely used device for the utilization of solar energy, but its energetic and economic values are still debated. A preliminary energy and economic analysis is presented. The energy analysis indicates that the energy needed to produce one solar collector is equivalent to the electricity consumed by an electric water heater in roughly three months. The economic analysis indicates that the pay-back time for a solar collector varies from 5.5 to 7.7 yr. according to the discount rate. The economic analysis from a national point of view indicates that the use of solar collectors for domestic purposes could only reduce electricity consumption in Israel by 10%.

Performance of jet impingement in unglazed air collectors

Energy Technology Data Exchange (ETDEWEB)

Belusko, M.; Saman, W.; Bruno, F. [Institute for Sustainable Systems and Technologies, University of South Australia, Mawson Lakes Boulevard, Mawson Lakes, SA 5095 (Australia)

2008-05-15

Jet impingement is effective at improving the heat transfer between air and a heated surface. Studies have shown that jet impingement can marginally improve the thermal efficiency of a glazed collector. However, little attention has been placed on applying jet impingement to an unglazed solar air collector. This paper presents a theoretical and experimental investigation identifying the performance characteristics of jet impingement. Overall, jet impingement was able to improve the thermal efficiency of the collector by 21%. An increase in the pressure loss was also measured but found to be small. The flow distribution of jets along the collector was the most significant factor in determining the efficiency. Increasing the hole spacing was found to improve the efficiency. (author)

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

ZnO-graphene quantum dots heterojunctions for natural sunlight-driven photocatalytic environmental remediation

Science.gov (United States)

Kumar, Suneel; Dhiman, Ankita; Sudhagar, Pitchaimuthu; Krishnan, Venkata

2018-07-01

In this work, we report the formation of heterojunctions comprising of graphene quantum dots (GQD) decorated ZnO nanorods (NR) and its use as efficient photocatalysts for environmental remediation. The heterojunctions has been designed to be active both in the UV and visible light regions and anticipated utilize the maximum part of the solar light spectrum. In this view, we examined the photocatalytic performance of our heterojunctions towards the degradation of colored pollutant (methylene blue (MB) dye) and a colorless pollutant (carbendazim (CZ) fungicide) under sunlight irradiation. Compared to bare photocatalyst ZnO and GQD, the heterojunction with 2 wt% of GQD (ZGQD2) showed the best photocatalytic activity by effectively degrading (about 95%) of organic pollutants (MB and CZ) from water within a short span of 70 min. The superior photocatalytic activity of these ZnO-GQD heterojunctions could be attributed to efficient charge carrier separation lead suppressed recombination rate at photocatalyst interfaces. In addition to the enhanced light absorption from UV to visible region, the high specific surface area of ZGQD2 heterojunction (353.447 m2 g-1) also imparts strong adsorption capacity for pollutants over catalyst surface, resulting in high photoactivity. Based on the obtained results, band gap alignment at ZnO-GQD heterojunction and active species trapping experiments, a plausible mechanism is proposed for photocatalytic reaction. The excellent photostability and recyclability of the ZnO-GQD heterojunctions fostering as promising photocatalyst candidate for environmental remediation applications.

Current Status and Future Prospects of Copper Oxide Heterojunction Solar Cells.

Science.gov (United States)

Wong, Terence K S; Zhuk, Siarhei; Masudy-Panah, Saeid; Dalapati, Goutam K

2016-04-07

The current state of thin film heterojunction solar cells based on cuprous oxide (Cu₂O), cupric oxide (CuO) and copper (III) oxide (Cu₄O₃) is reviewed. These p-type semiconducting oxides prepared by Cu oxidation, sputtering or electrochemical deposition are non-toxic, sustainable photovoltaic materials with application potential for solar electricity. However, defects at the copper oxide heterojunction and film quality are still major constraining factors for achieving high power conversion efficiency, η. Amongst the Cu₂O heterojunction devices, a maximum η of 6.1% has been obtained by using pulsed laser deposition (PLD) of Al x Ga 1- x O onto thermal Cu₂O doped with Na. The performance of CuO/n-Si heterojunction solar cells formed by magnetron sputtering of CuO is presently limited by both native oxide and Cu rich copper oxide layers at the heterointerface. These interfacial layers can be reduced by using a two-step sputtering process. A high η of 2.88% for CuO heterojunction solar cells has been achieved by incorporation of mixed phase CuO/Cu₂O nanopowder. CuO/Cu₂O heterojunction solar cells fabricated by electrodeposition and electrochemical doping has a maximum efficiency of 0.64% after surface defect passivation and annealing. Finally, early stage study of Cu₄O₃/GaN deposited on sapphire substrate has shown a photovoltaic effect and an η of ~10 -2 %.

An anomalous behavior in degraded bulk heterojunction organic solar cells

International Nuclear Information System (INIS)

Singh, Vinamrita; Tandon, Ram Pal; Arora, Swati; Kumar, Pankaj; Bhatnagar, Pramod Kumar; Arora, Manoj

2011-01-01

An anomalous behavior—a change in polarity with the passage of time in the bulk heterojunction poly(3-hexylthiophene) (P3HT):6,6-phenylC61 butyric acid methyl ester (PCBM) organic solar cells—is reported here. This work is a continuation of our previous work where the initial degradation of the organic solar cells, freshly prepared up to 4 h, was mainly due to domain formation in the active layer. With the passage of time, the activity at the interfaces starts becoming significant. A decrease of V OC and J SC , leading to a change in polarity, has been reported and explained up to 300 h after fabrication.

-MoS2 Lateral Heterojunctions

KAUST Repository

Li, Ming-yang; Pu, Jiang; Huang, Jing-Kai; Miyauchi, Yuhei; Matsuda, Kazunari; Takenobu, Taishi; Li, Lain-Jong

2018-01-01

2D layered heterostructures have attracted intensive interests due to their unique optical, transport, and interfacial properties. The laterally stitched heterojunction based on dissimilar 2D transition metal dichalcogenides forms an intrinsic p

Thermal performances of vertical hybrid PV/T air collector

Science.gov (United States)

Tabet, I.; Touafek, K.; Bellel, N.; Khelifa, A.

2016-11-01

In this work, numerical analyses and the experimental validation of the thermal behavior of a vertical photovoltaic thermal air collector are investigated. The thermal model is developed using the energy balance equations of the PV/T air collector. Experimental tests are conducted to validate our mathematical model. The tests are performed in the southern Algerian region (Ghardaïa) under clear sky conditions. The prototype of the PV/T air collector is vertically erected and south oriented. The absorber upper plate temperature, glass cover temperature, air temperature in the inlet and outlet of the collector, ambient temperature, wind speed, and solar radiation are measured. The efficiency of the collector increases with increase in mass flow of air, but the increase in mass flow of air reduces the temperature of the system. The increase in efficiency of the PV/T air collector is due to the increase in the number of fins added. In the experiments, the air temperature difference between the inlet and the outlet of the PV/T air collector reaches 10 ° C on November 21, 2014, the interval time is between 10:00 and 14:00, and the temperature of the upper plate reaches 45 ° C at noon. The mathematical model describing the dynamic behavior of the typical PV/T air collector is evaluated by calculating the root mean square error and mean absolute percentage error. A good agreement between the experiment and the simulation results is obtained.

A solar collector for air-conditioning

Energy Technology Data Exchange (ETDEWEB)

Kose, E. [Microtherm Energietechnik GmbH, 25 - Lods (France)

1999-03-01

A high performance Compound Parabolic Concentrator (CPC) collector is presented. It comprises dewar type tubular vacuum tubes with an absorber coating of very low emittance, a moderately concentrating reflector and a simple thermosyphon heat removal system. The reflectors car be designed with respect to the specific needs; reflector material, concentration, truncation and symmetry car be chosen freely. The collector allows the construction of cooling systems with higher COP's without using tracking systems. Land use and costs are greatly reduced. For a certain application (optimum yearly gain in Munich with a constant collector temperature of 180 deg C) the reflector was optimized, it is a fairly asymmetrical design. A symmetrical design with a similar performance has been tested, the results are shown. (author)

ON BIPOLAR SINGLE VALUED NEUTROSOPHIC GRAPHS

OpenAIRE

Said Broumi; Mohamed Talea; Assia Bakali; Florentin Smarandache

2016-01-01

In this article, we combine the concept of bipolar neutrosophic set and graph theory. We introduce the notions of bipolar single valued neutrosophic graphs, strong bipolar single valued neutrosophic graphs, complete bipolar single valued neutrosophic graphs, regular bipolar single valued neutrosophic graphs and investigate some of their related properties.

Attempted suicide in bipolar disorder: risk factors in a cohort of 6086 patients.

Directory of Open Access Journals (Sweden)

Dag Tidemalm

Full Text Available OBJECTIVE: Bipolar disorder is associated with high risk of self-harm and suicide. We wanted to investigate risk factors for attempted suicide in bipolar patients. METHOD: This was a cohort study of 6086 bipolar patients (60% women registered in the Swedish National Quality Register for Bipolar Disorder 2004-2011 and followed-up annually 2005-2012. Logistic regression was used to calculate adjusted odds ratios for fatal or non-fatal attempted suicide during follow-up. RESULTS: Recent affective episodes predicted attempted suicide during follow-up (men: odds ratio = 3.63, 95% CI = 1.76-7.51; women: odds ratio = 2.81, 95% CI = 1.78-4.44, as did previous suicide attempts (men: odds ratio = 3.93, 95% CI = 2.48-6.24; women: odds ratio = 4.24, 95% CI = 3.06-5.88 and recent psychiatric inpatient care (men: odds ratio = 3.57, 95% CI = 1.59-8,01; women: odds ratio = 2.68, 95% CI = 1.60-4.50. Further, those with many lifetime depressive episodes were more likely to attempt suicide. Comorbid substance use disorder was a predictor in men; many lifetime mixed episodes, early onset of mental disorder, personality disorder, and social problems related to the primary group were predictors in women. CONCLUSION: The principal clinical implication of the present study is to pay attention to the risk of suicidal behaviour in bipolar patients with depressive features and more severe or unstable forms of the disorder.

Thermal performance of evacuated tube heat pipe solar collector

Science.gov (United States)

Putra, Nandy; Kristian, M. R.; David, R.; Haliansyah, K.; Ariantara, Bambang

2016-06-01

The high fossil energy consumption not only causes the scarcity of energy but also raises problems of global warming. Increasing needs of fossil fuel could be reduced through the utilization of solar energy by using solar collectors. Indonesia has the abundant potential for solar energy, but non-renewable energy sources still dominate energy consumption. With heat pipe as passive heat transfer device, evacuated tube solar collector is expected to heat up water for industrial and home usage without external power supply needed to circulate water inside the solar collector. This research was conducted to determine the performance of heat pipe-based evacuated tube solar collector as solar water heater experimentally. The experiments were carried out using stainless steel screen mesh as a wick material, and water and Al2O3-water 0.1% nanofluid as working fluid, and applying inclination angles of 0°, 15°, 30°, and 45°. To analyze the heat absorbed and transferred by the prototype, water at 30°C was circulated through the condenser. A 150 Watt halogen lamp was used as sun simulator, and the prototype was covered by an insulation box to obtain a steady state condition with a minimum affection of ambient changes. Experimental results show that the usage of Al2O3-water 0.1% nanofluid at 30° inclination angle provides the highest thermal performance, which gives efficiency as high as 0.196 and thermal resistance as low as 5.32 °C/W. The use of nanofluid as working fluid enhances thermal performance due to high thermal conductivity of the working fluid. The increase of the inclination angle plays a role in the drainage of the condensate to the evaporator that leads to higher thermal performance until the optimal inclination angle is reached.

Daily efficiency of flat-plate solar air collectors for grain drying

Energy Technology Data Exchange (ETDEWEB)

Ting, K.C.; Shove, G.C.

1983-01-01

Single cover flat-plate solar collectors incorporated into walls and roofs of farm buildings have been used to heat ambient air for low temperature grain drying systems. Large surface area and high airflow rate are common features of these collectors. The drying period may range from several days to several weeks. Therefore, a knowledge of the variations of the collectors' daily efficiencies with respect to their design parameters would be helpful in applying solar collectors to grain drying. The objective of this study was to develop a simpler means of direct calculation of a collector's daily efficiency based on its design parameters. Many factors, such as configuration of the collector, airflow rate, weather conditions, etc. will affect the performance of solar collectors. A large number of varied conditions need to be tested in order to investigate the effect of different parameters on the collector performance. To facilitate this investigation, a computer simulation model developed by Ting was used to calculate the daily efficiencies of collectors under different operating conditions. The computer model was verified by Morrison's experimental data. Based on the simulation results, a functional relationship was developed between the daily efficiencies of collectors and their design parameters.

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.

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

A facility for the testing and repair of primary collectors of steam generators at WWER nuclear power plants

International Nuclear Information System (INIS)

Herman, M.; Kuna, M.

1990-01-01

A facility labelled ZOKPG-1 has been developed for in-service inspection and repair of steam generator collectors in WWER-440 nuclear power plants. The facility makes possible visual, capillary, luminescence and ultrasonic inspection and eddy current testing of the internal surface, base material and welded joints of the collector. The repair modules of the ZOKPG-1 manipulator enable electroerosive elimination of surface defects of the material and local electrochemical decontamination of the internal surfaces. The manipulator can be operated at temperatures up to 40 degC, humidity up to 100%, and in conditions of radiation load up to 15 mGy/h and of surface contamination on the order of 100 Bq/cm 2 . (Z.M.). 16 figs

Improved high-frequency equivalent circuit model based on distributed effects for SiGe HBTs with CBE layout

International Nuclear Information System (INIS)

Sun Ya-Bin; Li Xiao-Jin; Zhang Jin-Zhong; Shi Yan-Ling

2017-01-01

In this paper, we present an improved high-frequency equivalent circuit for SiGe heterojunction bipolar transistors (HBTs) with a CBE layout, where we consider the distributed effects along the base region. The actual device structure is divided into three parts: a link base region under a spacer oxide, an intrinsic transistor region under the emitter window, and an extrinsic base region. Each region is considered as a two-port network, and is composed of a distributed resistance and capacitance. We solve the admittance parameters by solving the transmission-line equation. Then, we obtain the small-signal equivalent circuit depending on the reasonable approximations. Unlike previous compact models, in our proposed model, we introduce an additional internal base node, and the intrinsic base resistance is shifted into this internal base node, which can theoretically explain the anomalous change in the intrinsic bias-dependent collector resistance in the conventional compact model. (paper)

Transparent Cu4O3/ZnO heterojunction photoelectric devices

Science.gov (United States)

Kim, Hong-Sik; Yadav, Pankaj; Patel, Malkeshkumar; Kim, Joondong; Pandey, Kavita; Lim, Donggun; Jeong, Chaehwan

2017-12-01

The present article reports the development of flexible, self-biased, broadband, high speed and transparent heterojunction photodiode, which is essentially important for the next generation electronic devices. We grow semitransparent p-type Cu4O3 using the reactive sputtering method at room temperature. The structural and optical properties of the Cu4O3 film were investigated by using the X-ray diffraction and UV-visible spectroscopy, respectively. The p-Cu4O3/n-ZnO heterojunction diode under dark condition yields rectification behavior with an extremely low saturation current value of 1.8 × 10-10 A and a zero bias photocurrent under illumination condition. The transparent p-Cu4O3/n-ZnO heterojunction photodetector can be operated without an external bias, due to the light-induced voltage production. The metal oxide heterojunction based on Cu4O3/ZnO would provide a route for the transparent and flexible photoelectric devices, including photodetectors and photovoltaics.

Bipolar Disorder.

Science.gov (United States)

Spearing, Melissa

Bipolar disorder, a brain disorder that causes unusual shifts in a person's mood, affects approximately one percent of the population. It commonly occurs in late adolescence and is often unrecognized. The diagnosis of bipolar disorder is made on the basis of symptoms, course of illness, and when possible, family history. Thoughts of suicide are…

Thermodynamic model to study a solar collector for its application to Stirling engines

International Nuclear Information System (INIS)

Abdollahpour, Amir; Ahmadi, Mohammad H.; Mohammadi, Amir H.

2014-01-01

Highlights: • A thermodynamic model is presented to study a solar collector for its application to Stirling engines. • The parabolic collector is analyzed based on optical and thermal. • Effects of changing some conditions and parameters are studied. - Abstract: Energy production through clean and green sources has been paid attention over the last decades owing to high energy consumption and environmental emission. Solar energy is one of the most useful energy sources. Due to high investment cost of centralized generation of electricity and considerable loss in the network, it is necessary to look forward to decentralized electricity generation technologies. Stirling engines have high efficiency and are able to be coupled with solar energy which cannot be applied in internal combustion engines. Solar Stirling engines can be commercialized and used to generate decentralized electricity in small to medium levels. One of the most important steps to set up an efficient solar Stirling engine is choosing and designing the collector. In this study, a solar parabolic collector with 3500 W of power for its application to Stirling engines was designed and analyzed (It is the thermal inlet power for a Stirling engine). We studied the parabolic collector based on optical and thermal analysis. In this case, solar energy is focused by a concentrating mirror and transferred to a pipe containing fluid. MATLAB software was used for obtaining the parameters of the collector, with respect to the geographic, temporal, and environmental conditions, fluid inlet temperature and some other considerations. After obtaining the results of the design, we studied the effects of changing some conditions and parameters such as annular space pressure, type of the gas, wind velocity, environment temperature and absorber pipe coating

Dual curvature acoustically damped concentrating collector. Final technical report

Energy Technology Data Exchange (ETDEWEB)

Smith, G.A.; Rausch, R.A.

1980-05-01

A development program was conducted to investigate the design and performance parameters of a novel, dual curvature, concentrating solar collector. The reflector of the solar collector is achieved with a stretched-film reflective surface that approximates a hyperbolic paraboloid and is capable of line-focusing at concentration ratios ranging from 10 to 20X. A prototype collector was designed based on analytical and experimental component trade-off activities as well as economic analyses of solar thermal heating and cooling systems incorporating this type of collector. A prototype collector incorporating six 0.66 x 1.22 m (2 x 4 ft) was fabricated and subjected to a limited thermal efficiency test program. A peak efficiency of 36% at 121/sup 0/C (250/sup 0/F) was achieved based upon the gross aperture area. Commercialization activities were conducted, including estimated production costs of $134.44/m/sup 2/ ($12.49/ft/sup 2/) for the collector assembly (including a local suntracker and controls) and $24.33/m/sup 2/ ($2.26/ft/sup 2/) for the reflector subassembly.

[Bipolar disorders in DSM-5].

Science.gov (United States)

Severus, E; Bauer, M

2014-05-01

In spring 2013 the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) edited by the American Psychiatric Association was published. The DSM-5 has also brought some important changes regarding bipolar disorders. The goal of this manuscript is to review the novelties in DSM-5 and to evaluate the implications of these changes. The diagnostic criteria as well as the additional remarks provided in the running text of DSM-5 were carefully appraised. For the first time diagnostic criteria are provided for disorders which up to now have been considered as subthreshold bipolar disorders. Furthermore, mixed episodes were eliminated and instead a mixed specifier was introduced. An increase in goal-directed activity/energy is now one of the obligatory symptoms for a (hypo)manic episode. Diagnostic guidance is provided as to when a (hypo)manic episode that has developed during treatment with an antidepressant has to be judged to be causally related to antidepressants and when this episode has only occurred coincidentally with antidepressant use. While some of the novelties are clearly useful, e.g. addition of increased goal-directed activity/energy as obligatory symptom for (hypo)manic episodes, this remains to be demonstrated for others, such as the definition of various subthreshold bipolar disorders.

Ambipolar organic heterojunction transistors with various p-type semiconductors

International Nuclear Information System (INIS)

Shi Jianwu; Wang Haibo; Song De; Tian Hongkun; Geng Yanhou; Yan Donghang

2008-01-01

Ambipolar transport has been realized in organic heterojunction transistors with metal phthalocyanines, phenanthrene-based conjugated oligomers as the first semiconductors and copper-hexadecafluoro-phthalocyanine as the second semiconductor. The electron and hole mobilities of ambipolar devices with rod-like molecules were comparable to the corresponding single component devices, while the carrier mobility of ambipolar devices with disk-like molecules was much lower than the corresponding single component devices. The much difference of their device performance was attributed to the roughness of the first semiconductor films, which was original from their distinct growth habits. The flat and continuous films for the first semiconductors layer can lead to a smooth heterojunction interface, and obtained a high device performance for ambipolar organic heterojunction transistors

Simulation of HPIB propagation in biased charge collector

International Nuclear Information System (INIS)

Li Hongyu; Qiu Aici

2004-01-01

A 2.5D PIC simulation using KARAT code for inner charge propagation within biased charge collector for measuring HPIB is presented. The simulation results indicate that the charges were neutralized but the current non-neutralized in the biased charge collector. The influence of ions collected vs biased voltage of the collector was also simulated. -800 V biased voltage can meet the measurement of 500 keV HPIB, and this is consistent with the experimental results

Performance analysis of photovoltaic thermal (PVT) water collectors

International Nuclear Information System (INIS)

Fudholi, Ahmad; Sopian, Kamaruzzaman; Yazdi, Mohammad H.; Ruslan, Mohd Hafidz; Ibrahim, Adnan; Kazem, Hussein A.

2014-01-01

Highlights: • Performances analysis of PVT collector based on energy efficiencies. • New absorber designs of PVT collectors were presented. • Comparison present study with other absorber collector designs was presented. • High efficiencies were obtained for spiral flow absorber. - Abstract: The electrical and thermal performances of photovoltaic thermal (PVT) water collectors were determined under 500–800 W/m 2 solar radiation levels. At each solar radiation level, mass flow rates ranging from 0.011 kg/s to 0.041 kg/s were introduced. The PVT collectors were tested with respect to PV efficiency, thermal efficiency, and a combination of both (PVT efficiency). The results show that the spiral flow absorber exhibited the highest performance at a solar radiation level of 800 W/m 2 and mass flow rate of 0.041 kg/s. This absorber produced a PVT efficiency of 68.4%, a PV efficiency of 13.8%, and a thermal efficiency of 54.6%. It also produced a primary-energy saving efficiency ranging from 79% to 91% at a mass flow rate of 0.011–0.041 kg/s

Integrated collector storage solar water heater: Temperature stratification

International Nuclear Information System (INIS)

Garnier, C.; Currie, J.; Muneer, T.

2009-01-01

An analysis of the temperature stratification inside an Integrated Collector Storage Solar Water Heater (ICS-SWH) was carried out. The system takes the form of a rectangular-shaped box incorporating the solar collector and storage tank into a single unit and was optimised for simulation in Scottish weather conditions. A 3-month experimental study on the ICS-SWH was undertaken in order to provide empirical data for comparison with the computed results. Using a previously developed macro model; a number of improvements were made. The initial macro model was able to generate corresponding water bulk temperature in the collector with a given hourly incident solar radiation, ambient temperature and inlet water temperature and therefore able to predict ICS-SWH performance. The new model was able to compute the bulk water temperature variation in different SWH collectors for a given aspect ratio and the water temperature along the height of the collector (temperature stratification). Computed longitudinal temperature stratification results obtained were found to be in close agreement with the experimental data.

Development of a Polymer-carbon Nanotubes based Economic Solar Collector

OpenAIRE

Kim, S. I.; Kissick, John; Spence, Stephen; Boyle, Christine

2014-01-01

A low cost solar collector was developed by using polymeric components as opposed to metal and glass components of traditional solar collectors. In order to utilize polymers for the absorber of the solar collector, Carbon Nanotubes (CNT) has been added as a filler to improve the thermal conductivity and the solar absorptivity of polymers. The solar collector was designed as a multi-layer construction with considering the economic manufacturing. Through the mathematical heat transfer analysis,...

Current Status and Future Prospects of Copper Oxide Heterojunction Solar Cells

Directory of Open Access Journals (Sweden)

Terence K. S. Wong

2016-04-01

Full Text Available The current state of thin film heterojunction solar cells based on cuprous oxide (Cu2O, cupric oxide (CuO and copper (III oxide (Cu4O3 is reviewed. These p-type semiconducting oxides prepared by Cu oxidation, sputtering or electrochemical deposition are non-toxic, sustainable photovoltaic materials with application potential for solar electricity. However, defects at the copper oxide heterojunction and film quality are still major constraining factors for achieving high power conversion efficiency, η. Amongst the Cu2O heterojunction devices, a maximum η of 6.1% has been obtained by using pulsed laser deposition (PLD of AlxGa1−xO onto thermal Cu2O doped with Na. The performance of CuO/n-Si heterojunction solar cells formed by magnetron sputtering of CuO is presently limited by both native oxide and Cu rich copper oxide layers at the heterointerface. These interfacial layers can be reduced by using a two-step sputtering process. A high η of 2.88% for CuO heterojunction solar cells has been achieved by incorporation of mixed phase CuO/Cu2O nanopowder. CuO/Cu2O heterojunction solar cells fabricated by electrodeposition and electrochemical doping has a maximum efficiency of 0.64% after surface defect passivation and annealing. Finally, early stage study of Cu4O3/GaN deposited on sapphire substrate has shown a photovoltaic effect and an η of ~10−2%.

Current Status and Future Prospects of Copper Oxide Heterojunction Solar Cells

Science.gov (United States)

Wong, Terence K. S.; Zhuk, Siarhei; Masudy-Panah, Saeid; Dalapati, Goutam K.

2016-01-01

The current state of thin film heterojunction solar cells based on cuprous oxide (Cu2O), cupric oxide (CuO) and copper (III) oxide (Cu4O3) is reviewed. These p-type semiconducting oxides prepared by Cu oxidation, sputtering or electrochemical deposition are non-toxic, sustainable photovoltaic materials with application potential for solar electricity. However, defects at the copper oxide heterojunction and film quality are still major constraining factors for achieving high power conversion efficiency, η. Amongst the Cu2O heterojunction devices, a maximum η of 6.1% has been obtained by using pulsed laser deposition (PLD) of AlxGa1−xO onto thermal Cu2O doped with Na. The performance of CuO/n-Si heterojunction solar cells formed by magnetron sputtering of CuO is presently limited by both native oxide and Cu rich copper oxide layers at the heterointerface. These interfacial layers can be reduced by using a two-step sputtering process. A high η of 2.88% for CuO heterojunction solar cells has been achieved by incorporation of mixed phase CuO/Cu2O nanopowder. CuO/Cu2O heterojunction solar cells fabricated by electrodeposition and electrochemical doping has a maximum efficiency of 0.64% after surface defect passivation and annealing. Finally, early stage study of Cu4O3/GaN deposited on sapphire substrate has shown a photovoltaic effect and an η of ~10−2%. PMID:28773398

Thwarted interpersonal needs and suicide ideation: Comparing psychiatric inpatients with bipolar and non-bipolar mood disorders.

Science.gov (United States)

Taylor, Nathanael J; Mitchell, Sean M; Roush, Jared F; Brown, Sarah L; Jahn, Danielle R; Cukrowicz, Kelly C

2016-12-30

Psychiatric inpatients are at heightened risk for suicide, and evidence suggests that psychiatric inpatients with bipolar mood disorders may be at greater risk for suicide ideation compared to those with non-bipolar mood disorders. There is a paucity of research directly comparing risk factors for suicide ideation in bipolar versus non-bipolar mood disorders in an inpatient sample. The current study sought to clarify the association between two constructs from the interpersonal theory of suicide (i.e., perceived burdensomeness and thwarted belongingness) in leading to suicide ideation among psychiatric inpatients with bipolar and non-bipolar mood disorders. Participants were (N=90) psychiatric inpatients with a bipolar (n = 20) or non-bipolar mood disorder (n=70; per their medical charts). Perceived burdensomeness, but not thwarted belongingness, was significantly associated with suicide ideation after adjusting for other covariates. This suggests perceived burdensomeness may play a key role in suicide ideation among psychiatric inpatients with any mood disorder and highlights the importance of assessment and intervention of perceived burdensomeness in this population. Contrary to our hypothesis, mood disorder group (i.e., bipolar versus non-bipolar) did not moderate the relations between perceived burdensomeness/thwarted belongingness and suicide ideation. Published by Elsevier Ireland Ltd.

Solar energy captured by a curved collector designed for architectural integration

International Nuclear Information System (INIS)

Rodríguez-Sánchez, D.; Belmonte, J.F.; Izquierdo-Barrientos, M.A.; Molina, A.E.; Rosengarten, G.; Almendros-Ibáñez, J.A.

2014-01-01

Highlights: • We present a new prototype of solar collector for architectural integration. • Equations of the solar radiation on a curved surface. • We compare the energy intercepted by the prototype with the energy intercepted by conventional collectors. • The prototype can be competitive compared with conventional collectors. - Abstract: In this paper we present a prototype for a new type of solar thermal collector designed for architectural integration. In this proposal, the conventional geometry of a flat solar thermal collector is changed to a curved geometry, to improve its visual impact when mounted on a building facade or roof. The mathematical equations for the beam and diffuse solar radiation received by a collector with this geometry are developed for two different orientations, horizontal and vertical. The performance of this curved prototype, in terms of solar radiation received, is compared with a conventional tilted-surface collector for different orientations in Madrid (Spain). The comparison is made for typical clear-sky days in winter and summer as well as for an entire year. The results demonstrate that the curved collector only receives between 12% and 25% less radiation than the conventional tilted-surface collectors when oriented horizontally, depending on the azimuth of the curved surface, although these percentages are reduced to approximately 50% when the collector is oriented vertically

Characterization of the polymer energy landscape in polymer:fullerene bulk heterojunctions with pure and mixed phases

KAUST Repository

Sweetnam, Sean

2014-10-08

Theoretical and experimental studies suggest that energetic offsets between the charge transport energy levels in different morphological phases of polymer:fullerene bulk heterojunctions may improve charge separation and reduce recombination in polymer solar cells (PSCs). In this work, we use cyclic voltammetry, UV-vis absorption, and ultraviolet photoelectron spectroscopy to characterize hole energy levels in the polymer phases of polymer:fullerene bulk heterojunctions. We observe an energetic offset of up to 150 meV between amorphous and crystalline polymer due to bandgap widening associated primarily with changes in polymer conjugation length. We also observe an energetic offset of up to 350 meV associated with polymer:fullerene intermolecular interactions. The first effect has been widely observed, but the second effect is not always considered despite being larger in magnitude for some systems. These energy level shifts may play a major role in PSC performance and must be thoroughly characterized for a complete understanding of PSC function.

Test results, Industrial Solar Technology parabolic trough solar collector

Energy Technology Data Exchange (ETDEWEB)

Dudley, V.E. [EG and G MSI, Albuquerque, NM (United States); Evans, L.R.; Matthews, C.W. [Sandia National Labs., Albuquerque, NM (United States)

1995-11-01

Sandia National Laboratories and Industrial Solar Technology are cost-sharing development of advanced parabolic trough technology. As part of this effort, several configurations of an IST solar collector were tested to determine the collector efficiency and thermal losses with black chrome and black nickel receiver selective coatings, combined with aluminized film and silver film reflectors, using standard Pyrex{reg_sign} and anti-reflective coated Pyrex{reg_sign} glass receiver envelopes. The development effort has been successful, producing an advanced collector with 77% optical efficiency, using silver-film reflectors, a black nickel receiver coating, and a solgel anti-reflective glass receiver envelope. For each receiver configuration, performance equations were empirically derived relating collector efficiency and thermal losses to the operating temperature. Finally, equations were derived showing collector performance as a function of input insolation value, incident angle, and operating temperature.

Potential of roof-integrated solar collectors for preheating air at drying facilities in Northern Thailand

Energy Technology Data Exchange (ETDEWEB)

Roman, Franz; Nagle, Marcus; Leis, Hermann; Mueller, Joachim [Institute of Agricultural Engineering 440e, University of Hohenheim, Garbenstrasse 9, 70599 Stuttgart (Germany); Janjai, Serm [Department of Physics, Silpakorn University, Nakhon Pathom (Thailand); Mahayothee, Busarakorn [Department of Food Technology, Silpakorn University, Nakhon Pathom (Thailand); Haewsungcharoen, Methinee [Department of Food Engineering, Chiang Mai University, Chiang Mai (Thailand)

2009-07-15

Longan is one of the most widely cropped fruits in Northern Thailand, where a significant amount of the annual harvest is commercially dried and exported as a commodity. Liquefied petroleum gas is generally used as the energy source for heating the drying air, but concern is growing as fuel prices are expected to increase for the foreseeable future. Meanwhile, with the ample solar radiation in Thailand, the roofs of drying facilities could be adapted to serve as solar collectors to preheat the drying air, thus reducing the energy requirement from fossil fuels. In this study, a simulation program for a flat-plate solar air heater was used to estimate the potential to preheat drying air given the conditions of several longan drying facilities. Results showed that solar collectors can replace up to 19.6% of the thermal energy demand during the drying season. Bigger collectors and smaller air channels result in more useful heat, but attention has to be paid to costs and pressure drop, respectively. Annual monetary savings can reach up to THB 56,000 ({approx}US$ 1800 at US$ 1 THB 31). (author)

Results of IEA SHC Task 45: Large Scale Solar Heating and Cooling Systems. Subtask A: “Collectors and Collector Loop”

DEFF Research Database (Denmark)

Bava, Federico; Nielsen, Jan Erik; Knabl, Samuel

2016-01-01

. Within this project, subtask A had the more specific objectives of investigating ways to evaluate the influence that different operating conditions can have on the collector performance, assure proper and safe installation of large solar collector fields, and guarantee their performance and yearly energy......The IEA SHC Task 45 Large Scale Solar Heating and Cooling Systems, carried out between January 2011 and December 2014, had the main objective to assist in the development of a strong and sustainable market of large solar heating systems by focusing on high performance and reliability of systems...... output. The results of the different investigations are presented, with a particular focus on how different parameters such as tilt, flow rate and fluid type, can affect the collector efficiency. Other presented results include methods to guarantee and check the thermal performance of a solar collector...

Mindfulness-based Cognitive Therapy for Non-remitted Patients with Bipolar Disorder

Science.gov (United States)

Deckersbach, Thilo; Hölzel, Britta K.; Eisner, Lori R.; Stange, Jonathan P.; Peckham, Andrew D.; Dougherty, Darin D.; Rauch, Scott L.; Lazar, Sara; Nierenberg, Andrew A.

2013-01-01

Introduction Bipolar disorder is characterized by recurrent episodes of depression and/or mania along with inter-episodic mood symptoms that interfere with psychosocial functioning. Despite periods of symptomatic recovery, many individuals with bipolar disorder continue to experience substantial residual mood symptoms that often lead to the recurrence of mood episodes. Aims The present study explored whether a new mindfulness-based cognitive therapy (MBCT) for bipolar disorder would increase mindfulness, reduce residual mood symptoms, and increase emotion regulation abilities, psychological well-being, positive affect and psychosocial functioning. Following a baseline clinical assessment, 12 individuals with DSM-IV bipolar disorder were treated with 12 group sessions of MBCT. Results At the end of treatment, as well as at the 3-months follow-up, participants showed increased mindfulness, lower residual depressive mood symptoms, less attentional difficulties, and increased emotion regulation abilities, psychological well-being, positive affect and psychosocial functioning. Conclusions These findings suggest that treating residual mood symptoms with MBCT may be another avenue to improving mood, emotion regulation, well-being and functioning in individuals with bipolar disorder. PMID:22070469

Treatment of the depressive phase of bipolar affective disorder: a review

International Nuclear Information System (INIS)

Muneer, A.

2013-01-01

Bipolar disorder is a chronic mood disorder which usually has its onset in adolescence and young adulthood. The disorder is typified by a remitting and relapsing course. While remissions are often partial in nature, relapses are frequent and manifested as manic, mixed, hypomanic and depressive episodes. Rapid cycling is a particularly disabling form of bipolar disorder, characterised by four or more episodes in a 12-month period. Bipolar disorder inevitably causes impairment in social and occupational functioning. Many patients experience severe hopelessness and suicidal ideation and the disorder is associated with one of the highest mortality rates of all psychiatric disorders. The treatment of bipolar depression is particularly challenging and numerous patients achieve incomplete benefit even with complex psychopharmacological strategies. In recent years, many new pharmacological options have become available for the treatment of bipolar depression and the field has seen significant progress. In order to achieve better outcome for the patients, it is mandatory that treating physicians have an up to date knowledge of recent advances in the management of this condition. (author)

An energy and exergy study of a solar thermal air collector

Directory of Open Access Journals (Sweden)

Mohseni-Languri Ehsan

2009-01-01

Full Text Available A solar flat plate air collector was manufactured in the north of Iran, and connected to a room as the model to study the possibility of using such solar heating systems in the northern parts of Iran. This collector was tested as a solar air heater to see how good it could be for warming up the test room during the winter. The experimental data obtained through accurate measurements were analyzed using second law approach to find the optimum mass flow rate, which leads to the maximum exergy efficiency. It was found that for the test setup at the test location, a mass flow rate of 0.0011 kg/s is the optimum mass flow rate for tested conditions which leads to the highest second law efficiency.

Advanced evacuated tube collectors

Science.gov (United States)

Schertz, W. W.; Hull, J. R.; Winston, R.; Ogallagher, J.

1985-04-01

The essence of the design concept for these new collectors is the integration of moderate levels of nonimaging concentration inside the evacuated tube itself. This permanently protects the reflection surfaces and allows the use of highly reflecting front surface mirrors with reflectances greater than 95%. Previous fabrication and long term testing of a proof-of-concept prototype has established the technical success of the concept. Present work is directed toward the development of a manufacturable unit that will be suitable for the widest possible range of applications. Design alternatives include scaling up the original prototype's tube diameter from 5 cm to 10 cm, using an internal shaped metal concentrating reflector, using a variety of profile shapes to minimize so-called gap losses and accommodate both single ended and double-ended flow geometries, and allowing the use of heat pipes for the absorber tube.

PERFORMANCE EVALUATION OF SOLAR COLLECTORS USING A SOLAR SIMULATOR

Directory of Open Access Journals (Sweden)

M. Norhafana

2015-11-01

Full Text Available Solar water heating systems is one of the applications of solar energy. One of the components of a solar water heating system is a solar collector that consists of an absorber. The performance of the solar water heating system depends on the absorber in the solar collector. In countries with unsuitable weather conditions, the indoor testing of solar collectors with the use of a solar simulator is preferred. Thus, this study is conducted to use a multilayered absorber in the solar collector of a solar water heating system as well as to evaluate the performance of the solar collector in terms of useful heat of the multilayered absorber using the multidirectional ability of a solar simulator at several values of solar radiation. It is operated at three variables of solar radiation of 400 W/m2, 550 W/m2 and 700 W/m2 and using three different positions of angles at 0º, 45º and 90º. The results show that the multilayer absorber in the solar collector is only able to best adapt at 45° of solar simulator with different values of radiation intensity. At this angle the maximum values of useful heat and temperature difference are achieved. KEYWORDS: solar water heating system; solar collector; multilayered absorber; solar simulator; solar radiation 

Evaluation of heat transfer enhancement in air-heating collectors

Energy Technology Data Exchange (ETDEWEB)

Mattox, D. L.

1979-06-01

The present research effort was initiated for the purpose of increasing the thermal efficiency of air heating solar collectors through identification and development of optimum design and operation criteria for solar absorber-to-air heat exchangers. Initially this effort took the form of a solar collector systems analysis to evaluate the impact of various techniques for enhancing the heat transfer between the absorber and air stream on overall thermal performance of the entire solar collector. This systems analysis resulted in the selection of solar collector designs providing ducted cooling air on the absorber shaded side as a base line. A transient heat transfer analysis of a complete solar air heating collector was used to demonstrate that an optimum absorber-to-air heat exchanger design could be provided with several interrupted fin configurations. Additional analyses were performed to establish that the maximum solar collector thermal performance to required pumping power was realized for a Reynolds number range of 1000 to 2000. This Reynolds number range was used to establish a theoretical design limit curve for maximum thermal performance versus required pumping power for all interrupted fin designs as published in the open literature. Heat and momentum transfer empirical relationships were defined for scaling the state-of-the-art high conductance fin designs identified from a compact configuration to the less compact designs needed for solar collectors.

Experimental investigation and thermodynamic performance analysis of a solar dryer using an evacuated-tube air collector

International Nuclear Information System (INIS)

Lamnatou, Chr.; Papanicolaou, E.; Belessiotis, V.; Kyriakis, N.

2012-01-01

Highlights: ► We evaluate an evacuated-tube solar air collector and use it to develop a novel dryer. ► Apple, carrot and apricot thin-layer drying experiments are conducted. ► Best overall fitting among several available thin-layer drying models is pursued. ► Thermodynamic analysis yields optimal collector area, energy utilization/exergy loss. ► The proposed dryer has a capacity for drying larger quantities of products. -- Abstract: The present work presents a thermodynamic performance analysis of a solar dryer with an evacuated-tube collector. Drying experiments for apples, carrots and apricots were conducted, after a preliminary stage of the investigation which included measurements for the determination of the collector efficiency. These results showed that the warm outlet air of the collector attains temperature levels suitable for drying of agricultural products without the need of preheating. Thus, the present collector was used as the heat source for a drying chamber in the frame of the development of a novel, convective, indirect solar dryer; given the fact that in the literature there are only a few studies about this type of collectors in conjunction with solar drying applications. Thin-layer drying models were fitted to the experimental drying curves, including the recent model of Diamante et al. which showed good correlation coefficients for all the tested products. Drying parameters such as moisture ratio and drying rates were calculated. Furthermore, an energetic/exergetic analysis of the dryer was also conducted and performance coefficients such as pick-up and exergy efficiencies, energy utilization ratio, exergy losses were determined for several configurations such as single and double-trays and several drying air velocities. On the other hand, an optimal collector surface area study was conducted, based on laws for minimum entropy generation. Design parameters such as optimum collector area were determined based on the minimum entropy

Hybrid tandem solar cells with depleted-heterojunction quantum dot and polymer bulk heterojunction subcells

KAUST Repository

Kim, Taesoo

2015-10-01

We investigate hybrid tandem solar cells that rely on the combination of solution-processed depleted-heterojunction colloidal quantum dot (CQD) and bulk heterojunction polymer:fullerene subcells. The hybrid tandem solar cell is monolithically integrated and electrically connected in series with a suitable p-n recombination layer that includes metal oxides and a conjugated polyelectrolyte. We discuss the monolithic integration of the subcells, taking into account solvent interactions with underlayers and associated constraints on the tandem architecture, and show that an adequate device configuration consists of a low bandgap CQD bottom cell and a high bandgap polymer:fullerene top cell. Once we optimize the recombination layer and individual subcells, the hybrid tandem device reaches a VOC of 1.3V, approaching the sum of the individual subcell voltages. An impressive fill factor of 70% is achieved, further confirming that the subcells are efficiently connected via an appropriate recombination layer. © 2015.

Large rectification magnetoresistance in nonmagnetic Al/Ge/Al heterojunctions

OpenAIRE

Zhang, Kun; Li, Huan-huan; Grünberg, Peter; Li, Qiang; Ye, Sheng-tao; Tian, Yu-feng; Yan, Shi-shen; Lin, Zhao-jun; Kang, Shi-shou; Chen, Yan-xue; Liu, Guo-lei; Mei, and Liang-mo

2015-01-01

Magnetoresistance and rectification are two fundamental physical properties of heterojunctions and respectively have wide applications in spintronics devices. Being different from the well known various magnetoresistance effects, here we report a brand new large magnetoresistance that can be regarded as rectification magnetoresistance: the application of a pure small sinusoidal alternating-current to the nonmagnetic Al/Ge Schottky heterojunctions can generate a significant direct-current volt...

High-efficiency omnidirectional photoresponses based on monolayer lateral p–n heterojunctions

KAUST Repository

Tsai, Meng-Lin; Li, Ming-yang; Shi, Yumeng; Chen, Lih-Juann; Li, Lain-Jong; He, Jr-Hau

2016-01-01

Electrical and optical properties of lateral monolayer WSe2–MoS2 p–n heterojunctions were characterized to demonstrate a high responsivity of 0.26 A W−1 with an excellent omnidirectional photodetection capability. The heterojunction functioning as a

Genetics Home Reference: bipolar disorder

Science.gov (United States)

... Email Facebook Twitter Home Health Conditions Bipolar disorder Bipolar disorder Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Bipolar disorder is a mental health condition that causes extreme ...

Impact of pressure losses in small-sized parabolic-trough collectors for direct steam generation

International Nuclear Information System (INIS)

Lobón, David H.; Valenzuela, Loreto

2013-01-01

Using PTC (parabolic-trough solar collectors) for industrial thermal processes in the temperature range up to 300 °C is not new, but in recent years there is a boosted interest in this type of concentrating solar technology. One of the problems that arise when designing PTC solar fields is how to deal with the pressure losses which are critical when producing saturated steam directly in the collectors. Depending on the characteristics of the collector, mainly on the receiver diameter, and on the nominal process conditions defined, a solar field configuration can be feasible or not. This paper presents a sensitivity analysis done using a software tool developed to study the thermo-hydraulic behaviour of PTC systems using water-steam as heat transfer fluid. In the case study presented, a small-sized PTC designed for industrial process heat applications is considered, which has a focal length of 0.2 m, an aperture area of 2 m 2 , and its receiver pipe has an inner diameter of 15 mm. Varied process conditions are inlet water pressure, temperature, and mass flow rate, solar irradiance and incidence angle of solar radiation. Results show that working pressure definition is particularly critical to make feasible or not the direct steam generation in solar collectors. - Highlights: • DSG (Direct steam generation) in small-sized parabolic-trough collectors. • Thermo-hydraulic sensitivity analysis. • Influence of working pressure and receiver geometry in DSG process

VALIDATION OF SIMULATION MODELS FOR DIFFERENTLY DESIGNED HEAT-PIPE EVACUATED TUBULAR COLLECTORS

DEFF Research Database (Denmark)

Fan, Jianhua; Dragsted, Janne; Furbo, Simon

2007-01-01

Differently designed heat-pipe evacuated tubular collectors have been investigated theoretically and experimentally. The theoretical work has included development of two TRNSYS [1] simulation models for heat-pipe evacuated tubular collectors utilizing solar radiation from all directions. One model...... coating on both sides. The input to the models is thus not a simple collector efficiency expression but the actual collector geometry. In this study, the TRNSYS models are validated with measurements for four differently designed heat-pipe evacuated tubular collectors. The collectors are produced...

Interfacial effects in organic semiconductor heterojunctions

International Nuclear Information System (INIS)

Stadler, P.

2011-01-01

The field of organic electronics has systematically gained interest in recent years, technologically and scientifically advances have been made leading to practical applications such as organic light emitting diodes, organic field-effect transistors and organic photo-voltaic cells. In this thesis a fundamental study on organic molecules is presented targeting on interfacial effects at organic heterojunctions. Generally in organic electronic devices interfaces are considered as key parameters for achieving high performance applications. Therefore in this work the emphasis is to investigate layer-by-layer heterojunctions of organic molecules. Defined heterojunctions at inorganic III-V semiconductors form superlattices and quantum-wells, which lead to interfacial effects summarized as quantum confinement and two-dimensional electron gases. Although organic molecules differ in many aspects from their inorganic counterparts, similar effects can be theoretically expected at organic heterojunctions as well. Organic molecules form van-der-Waals type crystals and domains which are macroscopically anisotropic and polycrystalline or amorphous. Organic molecules are intrinsic semiconductors and at interfaces dipoles are formed, which control the energy level alignment. In order to characterize such structures and compare them to inorganic superlattices and quantum-wells it is necessary to induce charge carriers. In this work this is established either by interfacial doping using high-performance dielectrics in a field-effect transistor structure or by photo-doping by exciting a donor-acceptor bilayer. In both cases C 60 was chosen as organic semiconductor exhibiting good acceptor properties and an electron mobility in the range of 0.5 cm 2 V -1 s -1 . The fabrication of well-defined few-molecular layers allows probing directly at the interface. Spectroscopic methods and transport measurements are applied for characterization: Photoemission spectroscopy, absorption and photo

Distributed-feedback single heterojunction GaAs diode laser

International Nuclear Information System (INIS)

Scifres, D.R.; Burnham, R.D.; Streifer, W.

1974-01-01

Laser operation of single-heterojunction GaAl As/GaAs diode lasers using a periodic structure within the gain medium of the device, thereby obviating the need for carefully cleaved end crystal faces to produce feedback, is reported. By varying the grating period, wavelengths from 8430 to 8560 A were observed. The threshold current densities were of the same order as for normal single heterojunction diode lasers. Some advantages in output wavelengths were observed over lasers with cleared faces. (U.S.)

Starting lithium prophylaxis early v. late in bipolar disorder

DEFF Research Database (Denmark)

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

2014-01-01

BACKGROUND: No study has investigated when preventive treatment with lithium should be initiated in bipolar disorder. AIMS: To compare response rates among patients with bipolar disorder starting treatment with lithium early v. late. METHOD: Nationwide registers were used to identify all patients...... with a diagnosis of bipolar disorder in psychiatric hospital settings who were prescribed lithium during the period 1995-2012 in Denmark (n = 4714). Lithium responders were defined as patients who, following a stabilisation lithium start-up period of 6 months, continued lithium monotherapy without being admitted...... to hospital. Early v. late intervention was defined in two ways: (a) start of lithium following first contact; and (b) start of lithium following a diagnosis of a single manic/mixed episode. RESULTS: Regardless of the definition used, patients who started lithium early had significantly decreased rates of non...

The impact of internal longitudinal fins in parabolic trough collectors operating with gases

International Nuclear Information System (INIS)

Bellos, Evangelos; Tzivanidis, Christos; Daniil, Ilias; Antonopoulos, Kimon A.

2017-01-01

Highlights: • In this study, the impact of internal fins in PTC operating with gases is presented. • Air, helium and CO_2 are tested in smooth absorber and with fins of 5–10 mm and 15 mm. • Greater fin length leads to higher thermal efficiency and 10 mm is the optimum length exergetically. • Helium is the best working fluid exergetically, with CO_2 and air to follow. • Up to 290 °C, helium performs better energetically, while CO_2 in higher temperatures. - Abstract: In this study, the use of internal fins in parabolic trough collectors operating with gas working fluids is examined. Air, helium and carbon dioxide are the investigated working fluids, while Eurotrough ET-150 is the examined solar collector. The design and the simulation of this solar collector are performed with the commercial software Solidworks Flow Simulation. The internal fins lead to higher thermal efficiency but also to higher pressure losses; something very important for the solar fields of Concentrated Power Plants. Thus, the collector is examined energetically and exergetically in order to take into account the increase in the useful output with the simultaneous greater need of pumping power. Various fin lengths are examined and finally the fin of 10 mm was proved to be the most appropriate exergetically. In working fluid comparison, helium is the most efficient working fluid exergetically for all the examined cases. In the thermal efficiency comparison, helium performs better up to 290 °C, while carbon dioxide is the best choice in higher temperature levels. Moreover, the optimum mass flow rate for the helium was proved to be 0.03 kg/s and for the other working fluids the value of 0.015 kg/s seems to lead to the most satisfying results.

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...

EFFICIENCY AND LIFETIME OF SOLAR COLLECTORS FOR SOLAR HEATING PLANTS

DEFF Research Database (Denmark)

The 12.5 m² flat plate solar collector HT, today marketed by Arcon Solvarme A/S, has been used in solar heating plants in Scandinavia since 1983. The collector is designed to operate in a temperature interval between 40°C and 90°C. The efficiency of the collector has been strongly improved since...... it was introduced on the market. The paper will present the increase of the efficiency of the collector due to technical improvements since 1983. Further, measurements from the spring of 2009 of the efficiency of two HT collectors, which have been in operation in the solar heating plant Ottrupgaard, Skørping......, Denmark since 1994 with a constant high flow rate and in the solar heating plant Marstal, Denmark since 1996 with a variable flow rate, will be presented. The efficiencies will be compared to the efficiencies of the collectors when they were first installed in the solar heating plants. The measurements...

EFFICIENCY AND LIFETIME OF SOLAR COLLECTORS FOR SOLAR HEATING PLANTS

DEFF Research Database (Denmark)

Fan, Jianhua; Chen, Ziqian; Furbo, Simon

2009-01-01

The 12.5 m² flat plate solar collector HT, today marketed by Arcon Solvarme A/S, has been used in solar heating plants in Scandinavia since 1983. The collector is designed to operate in a temperature interval between 40°C and 90°C. The efficiency of the collector has been strongly improved since...... it was introduced on the market. The paper will present the increase of the efficiency of the collector due to technical improvements since 1983. Further, measurements from the spring of 2009 of the efficiency of two HT collectors, which have been in operation in the solar heating plant Ottrupgaard, Skørping......, Denmark since 1994 with a constant high flow rate and in the solar heating plant Marstal, Denmark since 1996 with a variable flow rate, will be presented. The efficiencies will be compared to the efficiencies of the collectors when they were first installed in the solar heating plants. The measurements...

Efficient cascade multiple heterojunction organic solar cells with inverted structure

Science.gov (United States)

Guo, Tingting; Li, Mingtao; Qiao, Zhenfang; Yu, Leiming; Zhao, Jianhong; Feng, Nianjun; Shi, Peiguang; Wang, Xiaoyan; Pu, Xiaoyun; Wang, Hai

2018-05-01

In this work, we demonstrate an efficient cascade multiple heterojunction organic solar cell with inverted structure. By using two donor materials, poly(3-hexylthiosphene) (P3HT) and titanyl phthalocyanine (TiOPc), as well as two acceptor materials, [6,6]-phenyl C61 butyric acid methyl ester (PCBM) and C60, the cascade multiple heterojunctions of P3HT:PCBM/TiOPc:C60/C60 have been constructed. Applying the optimized inverted configuration of FTO/Zinc Tin Oxide (ZTO)/C60 (30 nm)/TiOPc:C60 (1:1.5, 25 nm)/P3HT:PCBM (1:0.8, 100 nm)/MoO3 (4 nm)/Ag, the considerably enhanced open circuit voltage (VOC) and short circuit current (JSC) can be harvested together, and the power conversion efficiency (PCE) is three times higher than that of the control cell with conventional structure. The significant improvements of the inverted cell are mostly due to the broadened spectral absorption and high efficient multi-interface exciton dissociation in the cascade multiple heterojunctions, indicating that the optimized cascade heterojunctions match the inverted structure well.

Bipolar Disorder in Women

Directory of Open Access Journals (Sweden)

Sermin Kesebir

2013-06-01

Full Text Available The research on gender's role in bipolar disorders has drawn significant interest recently. The presentation and course of bipolar disorder differs between women and men. Women experience depressive episodes, dysphoric mood, mixed states, rapid cycling and seasonal patterns more often than men. Comorbidity, particularly thyroid disease, migraine, obesity, and anxiety disorders laso occur more frequently in women than men. On the other hand men with bipolar disorder are also more likely than women to have problems with drug or alcohol abuse. The pregnancy and postpartum period is a time of high risk for onset and recurrence of bipolar disorder in women.

A stationary evacuated collector with integrated concentrator

Energy Technology Data Exchange (ETDEWEB)

Snail, K.A.; O' Gallagher, J.J.; Winston, R.

1984-01-01

A comprehensive set of experimental tests and detailed optical and thermal models are presented for a newly developed solar thermal collector. The new collector has an optical efficiency of 65 per cent and achieves thermal efficiencies of better than 50 per cent at fluid temperatures of 200/sup 0/C without tracking the sun. The simultaneous features of high temperature operation and a fully stationary mount are made possible by combining vacuum insulation, spectrally selective coatings, and nonimaging concentration in a novel way. These 3 design elements are ''integrated'' together in a self containe unit by shaping the outer glass envelope of a conventional evacuated tube into the profile of a nonimaging CPC-type concentrator. This permits the use of a first surface mirror and eliminates the need for second cover glazing. The new collector has been given the name ''Integrated Stationary Evacuated Concentrator'', or ISEC collector. Not only is the peak thermal efficiency of the ISEC comparable to that of commercial tracking parabolic troughs, but projections of the average yearly energy delivery also show competitive performance with a net gain for temperatures below 200/sup 0/C. In addition, the ISEC is less subject to exposure induced degradation and could be mass produced with assembly methods similar to those used with fluorescent lamps. Since no tracking or tilt adjustments are ever required and because its sensitive optical surfaces are protected from the environment, the ISEC collector provides a simple, easily maintained solar thermal collector for the range 100-300/sup 0/C which is suitable for most climates and atmospheric conditions. Potential applications include space heating, air conditioning, and industrial process heat.

Amorphous silicon/crystalline silicon heterojunctions for nuclear radiation detector applications

International Nuclear Information System (INIS)

Walton, J.T.; Hong, W.S.; Luke, P.N.; Wang, N.W.; Ziemba, F.P.

1996-10-01

Results on characterization of electrical properties of amorphous Si films for the 3 different growth methods (RF sputtering, PECVD [plasma enhanced], LPCVD [low pressure]) are reported. Performance of these a-Si films as heterojunctions on high resistivity p-type and n- type crystalline Si is examined by measuring the noise, leakage current, and the alpha particle response of 5mm dia detector structures. It is demonstrated that heterojunction detectors formed by RF sputtered films and PECVD films are comparable in performance with conventional surface barrier detectors. Results indicate that the a-Si/c-Si heterojunctions have the potential to greatly simplify detector fabrication. Directions for future avenues of nuclear particle detector development are indicated

Amorphous silicon/crystalline silicon heterojunctions for nuclear radiation detector applications

International Nuclear Information System (INIS)

Walton, J.T.; Hong, W.S.; Luke, P.N.; Wang, N.W.; Ziemba, F.P.

1996-01-01

Results on the characterization of the electrical properties of amorphous silicon films for the three different growth methods, RF sputtering, PECVD, and LPCVD are reported. The performance of these a-Si films as heterojunctions on high resistivity p-type and n-type crystalline silicon is examined by measuring the noise, leakage current and the alpha particle response of 5 mm diameter detector structures. It is demonstrated that heterojunction detectors formed by RF sputtered films and PECVD films are comparable in performance with conventional surface barrier detectors. The results indicate that the a-Si/c-Si heterojunctions have the potential to greatly simplify detector fabrication. Directions for future avenues of nuclear particle detector development are indicated

Anticonvulsivantes e antipsicóticos no tratamento do transtorno bipolar Anticonvulsants and antipsychotics in the treatment of Bipolar Disorder

Directory of Open Access Journals (Sweden)

Ricardo Alberto Moreno

2004-10-01

Full Text Available O transtorno bipolar é uma condição médica complexa e até o momento não há um tratamento único comprovadamente eficaz no controle de todos aspectos da doença. Foram revisadas a literatura disponível sobre o uso de anticonvulsivantes (valproato, carbamazepina, oxcarbazepina, lamotrigina, gabapentina, topiramato, clonazepam e antipsicóticos atípicos (clozapina, risperidona, olanzapina, quetiapina, ziprasidona e aripiprazole no tratamento agudo e profilático do transtorno bipolar. Existe um acúmulo de evidências acerca da eficácia do lítio na profilaxia e de ser melhor no tratamento da mania aguda do que nos episódios depressivos. Outros dados indicam que a carbamazepina e o valproato são eficazes na mania aguda. A lamotrigina parece reduzir ciclagem e ser eficaz em episódios depressivos. Baseado nas informações disponíveis, as evidências apontam a olanzapina como o antipsicótico atípico mais apropriado no tratamento de pacientes bipolares em mania, embora existam estudos sugerindo a eficácia da risperidona, aripiprazol e da clozapina. Resultados preliminares avaliando a eficácia de ziprasidona e quetiapina no transtorno bipolar ainda são bastante limitadas. Não há dados consistentes apoiando o uso profilático dos novos antipsicóticos.Bipolar disorder is a complex medical condition, and up to the date there is no single treatment with proven efficacy in the control of all aspects of the illness. The available literature on the use of anticonvulsants (valproate, carbamazepine, oxcarbazepine, lamotrigine, gabapentin, topiramate, clonazepam and atypical antipsychotics (clozapine, risperidone, olanzapine, quetiapine, ziprasidone, and aripiprazole for acute and prophylactic treatment of bipolar disorder was reviewed. There is a large amount of evidence that lithium is efficacious in the prophylaxis of episodes and better for acute mania than for depressive episodes. Other data show that carbamazepine and valproate are

Bipolar polygenic loading and bipolar spectrum features in major depressive disorder

NARCIS (Netherlands)

Wiste, Anna; Robinson, Elise B.; Milaneschi, Yuri; Meier, Sandra; Ripke, Stephan; Clements, Caitlin C.; Fitzmaurice, Garrett M.; Rietschel, Marcella; Penninx, Brenda W.; Smoller, Jordan W.; Perlis, Roy H.

Objectives Family and genetic studies indicate overlapping liability for major depressive disorder and bipolar disorder. The purpose of the present study was to determine whether this shared genetic liability influences clinical presentation. Methods A polygenic risk score for bipolar disorder,

Optimization of the functional domain of flat plate collectors

Science.gov (United States)

Ritoux, G.; Irigaray, J.-L.

1981-12-01

The variations of the extracted heat flux as function of the temperature of the heat transfer fluid in black and selective surface solar collectors are examined. The heat flux is calculated based on the difference of the initial to the stage of thermal equilibrium of the fluid. A nonlinear system of equations is developed and solved by a fast, iterative method to obtain the equilibrium temperatures. It is found that more flux can be extracted from the solar heat by a collector with only one glass cover than with more than one cover. The captured flux is proportional to the coefficient of transmission of the glass coverings, to the coefficient of absorption of the collector, and to the incident flux. Black painted surfaces were more absorbent than selective surfaces, and highest collection efficiencies were displayed by low temperature collectors. Charts of effective uses of the respective types of collectors for heating swimming pools, hot water, home heat, and for refrigeration and air-conditioning are provided.

Design, Simulation and Experimental Investigation of a Solar System Based on PV Panels and PVT Collectors

Directory of Open Access Journals (Sweden)

Annamaria Buonomano

2016-06-01

Full Text Available This paper presents numerical and experimental analyses aimed at evaluating the technical and economic feasibility of photovoltaic/thermal (PVT collectors. An experimental setup was purposely designed and constructed in order to compare the electrical performance of a PVT solar field with the one achieved by an identical solar field consisting of conventional photovoltaic (PV panels. The experimental analysis also aims at evaluating the potential advantages of PVT vs. PV in terms of enhancement of electrical efficiency and thermal energy production. The installed experimental set-up includes four flat polycrystalline silicon PV panels and four flat unglazed polycrystalline silicon PVT collectors. The total electrical power and area of the solar field are 2 kWe and 13 m2, respectively. The experimental set-up is currently installed at the company AV Project Ltd., located in Avellino (Italy. This study also analyzes the system from a numerical point of view, including a thermo-economic dynamic simulation model for the design and the assessment of energy performance and economic profitability of the solar systems consisting of glazed PVT and PV collectors. The experimental setup was modelled and partly simulated in TRNSYS environment. The simulation model was useful to analyze efficiencies and temperatures reached by such solar technologies, by taking into account the reference technology of PVTs (consisting of glazed collectors as well as to compare the numerical data obtained by dynamic simulations with the gathered experimental results for the PV technology. The numerical analysis shows that the PVT global efficiency is about 26%. Conversely, from the experimental point of view, the average thermal efficiency of PVT collectors is around 13% and the electrical efficiencies of both technologies are almost coincident and equal to 15%.

Recent advances in flat plate photovoltaic/thermal (PV/T) solar collectors

Energy Technology Data Exchange (ETDEWEB)

Ibrahim, Adnan; Othman, Mohd Yusof; Ruslan, Mohd Hafidz; Mat, Sohif; Sopian, Kamaruzzaman [Solar Energy Research Institute Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

2011-01-15

Flat plate photovoltaic/thermal (PV/T) solar collector produces both thermal energy and electricity simultaneously. This paper presents the state-of-the-art on flat plate PV/T collector classification, design and performance evaluation of water, air and combination of water and/or air based. This review also covers the future development of flat plate PV/T solar collector on building integrated photovoltaic (BIPV) and building integrated photovoltaic/thermal (BIPVT) applications. Different designs feature and performance of flat plate PV/T solar collectors have been compared and discussed. Future research and development (R and D) works have been elaborated. The tube and sheet design is the simplest and easiest to be manufactured, even though, the efficiency is 2% lower compared to other types of collectors such as, channel, free flow and two-absorber. It is clear from the review that for both air and water based PV/T solar collectors, the important key factors that influenced the efficiency of the system are the area where the collector covered, the number of passes and the gap between the absorber collector and solar cells. From the literature review, it is obvious that the flat plate PV/T solar collector is an alternative promising system for low-energy applications in residential, industrial and commercial buildings. Other possible areas for the future works of BIPVT are also mentioned. (author)

Wind load design methods for ground-based heliostats and parabolic dish collectors

Energy Technology Data Exchange (ETDEWEB)

Peterka, J A; Derickson, R G [Colorado State Univ., Fort Collins, CO (United States). Fluid Dynamics and Diffusion Lab.

1992-09-01

The purpose of this design method is to define wind loads on flat heliostat and parabolic dish collectors in a simplified form. Wind loads are defined for both mean and peak loads accounting for the protective influence of upwind collectors, wind protective fences, or other wind-blockage elements. The method used to define wind loads was to generalize wind load data obtained during tests on model collectors, heliostats or parabolic dishes, placed in a modeled atmospheric wind in a boundary-layer wind-tunnel at Colorado State University. For both heliostats and parabolic dishes, loads are reported for solitary collectors and for collectors as elements of a field. All collectors were solid with negligible porosity; thus the effects of porosity in the collectors is not addressed.

EFFECT OF BLENDING VARIOUS COLLECTORS AT BULK ...

African Journals Online (AJOL)

Nkana Concentrator under the ownership of the then Zambia Consolidated Copper Mines Ltd (ZCCM) had been using Sodium Ethyl Xanthate (SEX) mainly as a collector, but with the coming of new Mopani Copper Mines Plc (M.C.M), it was felt that there was a need to test alternative collectors in an attempt to improve the ...

Physically absorbable reagents-collectors in elementary flotation

Energy Technology Data Exchange (ETDEWEB)

S.A. Kondrat' ev; I.G. Bochkarev [Russian Academy of Sciences, Novosibirsk (Russian Federation). Institute of Mining

2007-09-15

Based on the reviewed researches held at the Institute of Mining, Siberian Branch, Russian Academy of Sciences, the effect of physically absorbable reagents-collectors on formation of a flotation complex and its stability in turbulent pulp flows in flotation machines of basic types is considered. The basic requirements for physically absorbable reagents-collectors at different flotation stages are established.

Psychological mechanisms and the ups and downs of personal recovery in bipolar disorder

OpenAIRE

Dodd, Alyson; Mezes, Barbara; Lobban, Fiona; Jones, Steven

2017-01-01

Background: Personal recovery is recognised as an important outcome for individuals with bipolar disorder (BD), and is distinct from symptomatic and functional recovery. Recovery-focused psychological therapies show promise. As with therapies aiming to delay relapse and improve symptoms, research on the psychological mechanisms underlying recovery is crucial to inform effective recovery-focused therapy. However, empirical work is limited. This study investigated whether negative beliefs about...

Illness perception of dropout patients followed up at bipolar outpatient clinic, Turkey.

Science.gov (United States)

Oflaz, Serap; Guveli, Hulya; Kalelioglu, Tevfik; Akyazı, Senem; Yıldızhan, Eren; Kılıc, Kasım Candas; Basyigit, Sehnaz; Ozdemiroglu, Filiz; Akyuz, Fatma; Gokce, Esra; Bag, Sevda; Kurt, Erhan; Oral, Esat Timucin

2015-06-01

Dropout is a common problem in the treatment of psychiatric illnesses including bipolar disorders (BD). The aim of the present study is to investigate illness perceptions of dropout patients with BD. A cross sectional study was done on the participants who attended the Mood Disorder Outpatient Clinic at least 3 times from January 2003 through June 2008, and then failed to attend clinic till to the last one year, 2009, determined as dropout. Thirty-nine dropout patients and 39 attendent patients with BD were recruited for this study. A sociodemographic form and brief illness perception questionnaire were used to capture data. The main reasons of patients with BD for dropout were difficulties of transport (31%), to visit another doctor (26%), giving up drugs (13%) and low education level (59%) is significant for dropout patients. The dropout patients reported that their illness did not critically influence their lives, their treatment had failed to control their illnesses, they had no symptoms, and that their illness did not emotionally affect them. In conclusion, the nonattendance of patients with serious mental illness can result in non-compliance of therapeutic drug regimens, and a recurrence of the appearance symptoms. The perception of illness in dropout patients with BD may be important for understanding and preventing nonattendance. Copyright © 2015 Elsevier B.V. All rights reserved.

The PKI collector

Science.gov (United States)

Rice, M. P.

1982-07-01

The design and manufacturing of a solar thermal collector is discussed. The collector has three primary subsystems: concentrator, receiver/fluid loop, and controls. Identical curved reflective columns are utilized in a faceted Fresnel design to support 864 one foot square flat inexpensive second-surface, silvered glass mirrors. The columns are ganged together and rotated through their centers of gravity to provide elevation tracking. The concentrator is supported by a lightweight spaceframe structure which distributes all wind and gravity loads to the base supports. The base of the structure is a track which rotates on wheels mounted on concrete piers. A parallel tube steel heat exchanger is mounted at the concentrator focal area in a well insulated, galvanized steel housing. Two rows of vertical close-packed, staggered tubes connect a mud header and a steam header. Automatic two axis tracking and operational control is provided with a microprocessor based package. Concentrator-mounted shadowbands are the basis for active tracking. A software program provides azimuthal tracking during cloudy periods.

Early Intervention in Bipolar Disorder.

Science.gov (United States)

Vieta, Eduard; Salagre, Estela; Grande, Iria; Carvalho, André F; Fernandes, Brisa S; Berk, Michael; Birmaher, Boris; Tohen, Mauricio; Suppes, Trisha

2018-05-01

Bipolar disorder is a recurrent disorder that affects more than 1% of the world population and usually has its onset during youth. Its chronic course is associated with high rates of morbidity and mortality, making bipolar disorder one of the main causes of disability among young and working-age people. The implementation of early intervention strategies may help to change the outcome of the illness and avert potentially irreversible harm to patients with bipolar disorder, as early phases may be more responsive to treatment and may need less aggressive therapies. Early intervention in bipolar disorder is gaining momentum. Current evidence emerging from longitudinal studies indicates that parental early-onset bipolar disorder is the most consistent risk factor for bipolar disorder. Longitudinal studies also indicate that a full-blown manic episode is often preceded by a variety of prodromal symptoms, particularly subsyndromal manic symptoms, therefore supporting the existence of an at-risk state in bipolar disorder that could be targeted through early intervention. There are also identifiable risk factors that influence the course of bipolar disorder, some of them potentially modifiable. Valid biomarkers or diagnosis tools to help clinicians identify individuals at high risk of conversion to bipolar disorder are still lacking, although there are some promising early results. Pending more solid evidence on the best treatment strategy in early phases of bipolar disorder, physicians should carefully weigh the risks and benefits of each intervention. Further studies will provide the evidence needed to finish shaping the concept of early intervention. AJP AT 175 Remembering Our Past As We Envision Our Future April 1925: Interpretations of Manic-Depressive Phases Earl Bond and G.E. Partridge reviewed a number of patients with manic-depressive illness in search of a unifying endo-psychic conflict. They concluded that understanding either phase of illness was "elusive" and

Increasing efficiency of a 33 MW OTEC in Indonesia using flat-plate solar collector for the seawater heater

Directory of Open Access Journals (Sweden)

Iwan Rohman Setiawan

2017-07-01

Full Text Available This paper presents a design concept of Ocean Thermal Energy Conversion (OTEC plant built in Mamuju, West Sulawesi, with 33 MWe and 7.1% of the power capacity and efficiency, respectively. The generated electrical power and the efficiency of OTEC plant are enhanced by a simulation of a number of derived formulas. Enhancement of efficiency is performed by increasing the temperature of the warm seawater toward the evaporator from 26˚C up to 33.5˚C using a flat-plate solar collector. The simulation results show that by increasing these a water temperature up to 33.5˚C, the generated power will increase up to 144.155 MWe with the OTEC efficiency up to 9.54%, respectively. The required area of flat-plate solar collector to achieve the results is around 6.023 x 106 m2.

Humidification dehumidification desalination system using parabolic trough solar air collector

International Nuclear Information System (INIS)

Al-Sulaiman, Fahad A.; Zubair, M. Ifras; Atif, Maimoon; Gandhidasan, Palanichamy; Al-Dini, Salem A.; Antar, Mohamed A.

2015-01-01

This paper deals with a detailed thermodynamic analysis to assess the performance of an HDH system with an integrated parabolic trough solar collector (PTSC). The HDH system considered is an open air, open water, air heated system that uses a PTSC as an air heater. Two different configurations were considered of the HDH system. In the first configuration, the solar air heater was placed before the humidifier whereas in the second configuration the solar air heater was placed between the humidifier and the dehumidifier. The current study revealed that PTSCs are well suited for air heated HDH systems for high radiation location, such as Dhahran, Saudi Arabia. The comparison between the two HDH configurations demonstrates that the gained output ratio (GOR) of the first configuration is, on average, about 1.5 whereas for the second configuration the GOR increases up to an average value of 4.7. The study demonstrates that the HDH configuration with the air heater placed between the humidifier and the dehumidifier has a better performance and a higher productivity. - Highlights: • Thermodynamic analysis of an HDH system driven by a parabolic trough solar collector was conducted. • The first configuration reveals a GOR of 1.5 while the second configuration reveals a GOR of 4.7. • Effective heating of the HDH system was obtained through parabolic trough solar collector

A five year follow-up study of 11 patients with bipolar disorder Seguimento de 11 pacientes com transtorno bipolar por cinco anos

Directory of Open Access Journals (Sweden)

Fernanda Novis

2010-01-01

Full Text Available OBJECTIVE: To study the long-term follow-up of patients with bipolar disorder (BPD. METHOD: Eleven outpatients with BPD type I were followed up naturalistically for five years at a university teaching hospital. The Clinical Global Impression Scale (BPD version was used to evaluate the occurrence of affective episodes, and the Strauss-Carpenter Outcome Scale was used to evaluate social and occupational functioning. RESULTS: The majority of patients were symptomatic most of the time, with predominantly depressive episodes. Overall, patients remained euthymic a mean of 47.7% of the time. Despite a low rate of hospitalization, social and occupational functioning was poor in the majority of patients. A poor disease course with respect to work-related functioning was associated with fewer months of euthymia with a longer duration of depressive episodes. The total number of months of euthymia negatively correlated with the patient's age and disease duration. CONCLUSION: Despite the small sample size, the present findings appear to corroborate previous studies on the evolution of BPD. Most of the patients had a poor disease course, with long symptomatic periods, particularly depressive episodes, and significantly impaired social and occupational functioning.OBJETIVO: Estudar a evolução de longo prazo do transtorno bipolar (TB. MÉTODO: Onze pacientes com TB do tipo I foram acompanhados de forma naturalística em um ambulatório universitário por cinco anos. Foram utilizadas a Escala de Impressão Clínica Global (versão TB, para a avaliação dos episódios afetivos, e a Escala de Evolução Strauss-Carpenter, para a avaliação do funcionamento sócio-ocupacional. RESULTADOS: A maioria dos pacientes esteve sintomática a maior parte do tempo, apresentando predominantemente quadros depressivos. Em média, os pacientes ficaram em eutimia durante 47,7% do tempo. Apesar do baixo índice de hospitalização, a maioria dos pacientes apresentou

Virginia Woolf, neuroprogression, and bipolar disorder

Directory of Open Access Journals (Sweden)

Manuela V. Boeira

2016-01-01

Full Text Available Family history and traumatic experiences are factors linked to bipolar disorder. It is known that the lifetime risk of bipolar disorder in relatives of a bipolar proband are 5-10% for first degree relatives and 40-70% for monozygotic co-twins. It is also known that patients with early childhood trauma present earlier onset of bipolar disorder, increased number of manic episodes, and more suicide attempts. We have recently reported that childhood trauma partly mediates the effect of family history on bipolar disorder diagnosis. In light of these findings from the scientific literature, we reviewed the work of British writer Virginia Woolf, who allegedly suffered from bipolar disorder. Her disorder was strongly related to her family background. Moreover, Virginia Woolf was sexually molested by her half siblings for nine years. Her bipolar disorder symptoms presented a pernicious course, associated with hospitalizations, suicidal behavioral, and functional impairment. The concept of neuroprogression has been used to explain the clinical deterioration that takes places in a subgroup of bipolar disorder patients. The examination of Virgina Woolf’s biography and art can provide clinicians with important insights about the course of bipolar disorder.

Psychological mechanisms and the ups and downs of personal recovery in bipolar disorder.

Science.gov (United States)

Dodd, Alyson L; Mezes, Barbara; Lobban, Fiona; Jones, Steven H

2017-09-01

Personal recovery is recognized as an important outcome for individuals with bipolar disorder (BD) and is distinct from symptomatic and functional recovery. Recovery-focused psychological therapies show promise. As with therapies aiming to delay relapse and improve symptoms, research on the psychological mechanisms underlying recovery is crucial to inform effective recovery-focused therapy. However, empirical work is limited. This study investigated whether negative beliefs about mood swings and self-referent appraisals of mood-related experiences were negatively associated with personal recovery. Cross-sectional online survey. People with a verified research diagnosis of BD (n = 87), recruited via relevant voluntary sector organizations and social media, completed online measures. Pearson's correlations and multiple regression analysed associations between appraisals, beliefs, and recovery. Normalizing appraisals of mood changes were positively associated with personal recovery. Depression, negative self-appraisals of depression-relevant experiences, extreme positive and negative appraisals of activated states, and negative beliefs about mood swings had negative relationships with recovery. After controlling for current mood symptoms, negative illness models (relating to how controllable, long-term, concerning, and treatable mood swings are; β = -.38), being employed (β = .39), and both current (β = -.53) and recent experience of depression (β = .30) predicted recovery. Due to the cross-sectional design, causality cannot be determined. Participants were a convenience sample primarily recruited online. Power was limited by the sample size. Interventions aiming to empower people to feel able to manage mood and catastrophize less about mood swings could facilitate personal recovery in people with BD, which might be achieved in recovery-focused therapy. Personal recovery is an important outcome for people living with bipolar disorder More positive

Low social rhythm regularity predicts first onset of bipolar spectrum disorders among at-risk individuals with reward hypersensitivity.

Science.gov (United States)

Alloy, Lauren B; Boland, Elaine M; Ng, Tommy H; Whitehouse, Wayne G; Abramson, Lyn Y

2015-11-01

The social zeitgeber model (Ehlers, Frank, & Kupfer, 1988) suggests that irregular daily schedules or social rhythms provide vulnerability to bipolar spectrum disorders. This study tested whether social rhythm regularity prospectively predicted first lifetime onset of bipolar spectrum disorders in adolescents already at risk for bipolar disorder based on exhibiting reward hypersensitivity. Adolescents (ages 14-19 years) previously screened to have high (n = 138) or moderate (n = 95) reward sensitivity, but no lifetime history of bipolar spectrum disorder, completed measures of depressive and manic symptoms, family history of bipolar disorder, and the Social Rhythm Metric. They were followed prospectively with semistructured diagnostic interviews every 6 months for an average of 31.7 (SD = 20.1) months. Hierarchical logistic regression indicated that low social rhythm regularity at baseline predicted greater likelihood of first onset of bipolar spectrum disorder over follow-up among high-reward-sensitivity adolescents but not moderate-reward-sensitivity adolescents, controlling for follow-up time, gender, age, family history of bipolar disorder, and initial manic and depressive symptoms (β = -.150, Wald = 4.365, p = .037, odds ratio = .861, 95% confidence interval [.748, .991]). Consistent with the social zeitgeber theory, low social rhythm regularity provides vulnerability to first onset of bipolar spectrum disorder among at-risk adolescents. It may be possible to identify adolescents at risk for developing a bipolar spectrum disorder based on exhibiting both reward hypersensitivity and social rhythm irregularity before onset occurs. (c) 2015 APA, all rights reserved).

Rational Design of Zinc Phosphide Heterojunction Photovoltaics

Science.gov (United States)

Bosco, Jeffrey Paul

The prospect of terawatt-scale electricity generation using a photovoltaic (PV) device places strict requirements on the active semiconductor optoelectronic properties and elemental abundance. After reviewing the constraints placed on an ``earth-abundant'' solar absorber, we find zinc phosphide (α-Zn 3P2) to be an ideal candidate. In addition to its near-optimal direct band gap of 1.5 eV, high visible-light absorption coefficient (>10. 4cm-1), and long minority-carrier diffusion length (>5 μm), Zn3P 2 is composed of abundant Zn and P elements and has excellent physical properties for scalable thin-film deposition. However, to date, a Zn 3P2 device of sufficient efficiency for commercial applications has not been demonstrated. Record efficiencies of 6.0% for multicrystalline and 4.3% for thin-film cells have been reported, respectively. Performance has been limited by the intrinsic p-type conductivity of Zn3P 2 which restricts us to Schottky and heterojunction device designs. Due to our poor understanding of Zn3P2 interfaces, an ideal heterojunction partner has not yet been found. The goal of this thesis is to explore the upper limit of solar conversion efficiency achievable with a Zn3P2 absorber through the design of an optimal heterojunction PV device. To do so, we investigate three key aspects of material growth, interface energetics, and device design. First, the growth of Zn3P2 on GaAs(001) is studied using compound-source molecular-beam epitaxy (MBE). We successfully demonstrate the pseudomorphic growth of Zn3P2 epilayers of controlled orientation and optoelectronic properties. Next, the energy-band alignments of epitaxial Zn3P2 and II-VI and III-V semiconductor interfaces are measured via high-resolution x-ray photoelectron spectroscopy in order to determine the most appropriate heterojunction partner. From this work, we identify ZnSe as a nearly ideal n-type emitter for a Zn3P 2 PV device. Finally, various II-VI/Zn3P2 heterojunction solar cells designs are

Epidemiology in Pediatric Bipolar Disorder

Directory of Open Access Journals (Sweden)

Caner Mutlu

2015-12-01

Full Text Available Childhood and adolescent bipolar disorder diagnosis has been increasing recently. Since studies evaluating attempted suicide rates in children and adolescents have shown bipolarity to be a significant risk factor, diagnosis and treatment of bipolarity has become a very important issue. Since there is a lack of specific diagnostic criteria for especially preadolescent samples and evaluations are made mostly symptomatically, suspicions about false true diagnosis and increased prevalence rates have emerged. This situation leads to controversial data about the prevalence rates of bipolar disorder in children and adolescents. The aim of this article is to review the prevalence of childhood and adolescent bipolar disorder in community, inpatient and outpatient based samples in literature.

BIPOLAR DISORDER: A REVIEW

OpenAIRE

Pathan Dilnawaz N; Ziyaurrahaman A.R; Bhise K.S.

2010-01-01

Bipolar disorder (BD) is a severe psychiatric disorder that results in poor global functioning, reduced quality of life and high relapse rates. Research finds that many adults with bipolar disorder identify the onset of symptoms in childhood and adolescence, indicating the importance of early accurate diagnosis and treatment. Accurate diagnosis of mood disorders is critical for treatment to be effective. Distinguishing between major depression and bipolar disorders, especially the depressed p...

Zinc-oxide nanorod / copper-oxide thin-film heterojunction for a nitrogen-monoxide gas sensor

International Nuclear Information System (INIS)

Yoo, Hwansu; Kim, Hyojin; Kim, Dojin

2014-01-01

A novel p - n oxide heterojunction structure was fabricated by employing n-type zinc-oxide (ZnO) nanorods grown on an indium-tin-oxide-coated glass substrate by using the hydrothermal method and a p-type copper-oxide (CuO) thin film deposited onto the ZnO nanorod array by using the sputtering method. The crystallinities and microstructures of the heterojunction materials were examined by using X-ray diffraction and scanning electron microscopy. The observed current - voltage characteristics of the p - n oxide heterojunction showed a nonlinear diode-like rectifying behavior. The effects of an oxidizing or electron acceptor gas, such as nitrogen monoxide (NO), on the ZnO nanorod/CuO thin-film heterojunction were investigated to determine the potential applications of the fabricated material for use in gas sensors. The forward current of the p - n heterojunction was remarkably reduced when NO gas was introduced into dry air at temperatures from 100 to 250 .deg. C. The NO gas response of the oxide heterojunction reached a maximum value at an operating temperature of 180 .deg. C and linearly increased as the NO gas concentration was increased from 5 to 30 ppm. The sensitivity value was observed to be as high as 170% at 180 .deg. C when biased at 2 V in the presence of 20-ppm NO. The ZnO nanorod/CuO thin-film heterojunction also exhibited a stable and repeatable response to NO gas. The experimental results suggest that the ZnO nanorod/CuO thin-film heterojunction structure may be a novel candidate for gas sensors.

Zinc-oxide nanorod / copper-oxide thin-film heterojunction for a nitrogen-monoxide gas sensor

Energy Technology Data Exchange (ETDEWEB)

Yoo, Hwansu; Kim, Hyojin; Kim, Dojin [Chungnam National University, Daejeon (Korea, Republic of)

2014-11-15

A novel p - n oxide heterojunction structure was fabricated by employing n-type zinc-oxide (ZnO) nanorods grown on an indium-tin-oxide-coated glass substrate by using the hydrothermal method and a p-type copper-oxide (CuO) thin film deposited onto the ZnO nanorod array by using the sputtering method. The crystallinities and microstructures of the heterojunction materials were examined by using X-ray diffraction and scanning electron microscopy. The observed current - voltage characteristics of the p - n oxide heterojunction showed a nonlinear diode-like rectifying behavior. The effects of an oxidizing or electron acceptor gas, such as nitrogen monoxide (NO), on the ZnO nanorod/CuO thin-film heterojunction were investigated to determine the potential applications of the fabricated material for use in gas sensors. The forward current of the p - n heterojunction was remarkably reduced when NO gas was introduced into dry air at temperatures from 100 to 250 .deg. C. The NO gas response of the oxide heterojunction reached a maximum value at an operating temperature of 180 .deg. C and linearly increased as the NO gas concentration was increased from 5 to 30 ppm. The sensitivity value was observed to be as high as 170% at 180 .deg. C when biased at 2 V in the presence of 20-ppm NO. The ZnO nanorod/CuO thin-film heterojunction also exhibited a stable and repeatable response to NO gas. The experimental results suggest that the ZnO nanorod/CuO thin-film heterojunction structure may be a novel candidate for gas sensors.

Energy Analysis of Solar Collector With perforated Absorber Plate

Directory of Open Access Journals (Sweden)

Ammar A. Farhan

2017-09-01

Full Text Available The thermal performance of three solar collectors with 3, 6 mm and without perforation absorber plate was assessed experimentally. The experimental tests were implemented in Baghdad during the January and February 2017. Five values of airflow rates range between 0.01 – 0.1 m3/s were used through the test with a constant airflow rate during the test day. The variation of the following parameters air temperature difference, useful energy, absorber plate temperature, and collector efficiency was recorded every 15 minutes. The experimental data reports that the increases the number of absorber plate perforations with a small diameter is more efficient rather than increasing the hole diameter of the absorber plate with decreasing the perforation numbers. Maximum air temperature difference throughout the solar collector with 3, 6 mm perforations and without perforations are 17, 15, and 12 oC, respectively. Also, it can be concluded that the energy gained from the solar collector with 3 mm perforation absorber plate is 28.2 % more than the energy gained from solar collector without holes per day for 0.1 m3/s airflow rate. The maximum values of the thermal performance curves are 0.67, 0.64, and 0.56 for the solar collector with 3, 6 mm, and without perforations, respectively.

Optimum solar collector fluid flow rates

DEFF Research Database (Denmark)

Furbo, Simon; Shah, Louise Jivan

1996-01-01

Experiments showed that by means of a standard electronically controlled pump, type UPE 2000 from Grundfos it is possible to control the flow rate in a solar collector loop in such a way that the flow rate is strongly influenced by the temperature of the solar collector fluid passing the pump....... The flow rate is increasing for increasing temperature.The flow rate at the high temperature level is typically 70 % greater than the flow rate at the low temperature level.Further, the energy consumption for the electronically controlled pump in a solar heating system will be somewhat smaller than...... the energy consumption of a normal ciculation pump in the solar heating system.Calculations showed that the highest thermal performances for small SDHW systems based on mantle tanks with constant volume flow rates in the solar collector loops are achieved if the flow rate is situated in the interval from 0...

The distinct temperament profiles of bipolar I, bipolar II and unipolar patients.

Science.gov (United States)

Akiskal, Hagop S; Kilzieh, Nael; Maser, Jack D; Clayton, Paula J; Schettler, Pamela J; Traci Shea, M; Endicott, Jean; Scheftner, William; Hirschfeld, Robert M A; Keller, Martin B

2006-05-01

Despite a plethora of studies, controversies abound on whether the long-term traits of unipolar and bipolar patients could be differentiated by temperament and whether these traits, in turn, could be distinguished from subthreshold affective symptomatology. 98 bipolar I (BP-I), 64 bipolar II (BP-II), and 251 unipolar major depressive disorder (UP-MDD) patients all when recovered from discrete affective episodes) and 617 relatives, spouses or acquaintances without lifetime RDC diagnoses (the comparison group, CG) were administered a battery of 17 self-rated personality scales chosen for theoretical relevance to mood disorders. Subsamples of each of the four groups also received the General Behavior Inventory (GBI). Of the 436 personality items, 103 that significantly distinguished the three patient groups were subjected to principal components analysis, yielding four factors which reflect the temperamental dimensions of "Mood Lability", "Energy-Assertiveness," "Sensitivity-Brooding," and "Social Anxiety." Most BP-I described themselves as near normal in emotional stability and extroversion; BP-II emerged as labile in mood, energetic and assertive, yet sensitive and brooding; MDD were socially timid, sensitive and brooding. Gender and age did not have marked influence on these overall profiles. Within the MDD group, those with baseline dysthymia were the most pathological (i.e., high in neuroticism, insecurity and introversion). Selected GBI items measuring hypomania and biphasic mood changes were endorsed significantly more often by BP-II. Finally, it is relevant to highlight a methodologic finding about the precision these derived temperament factors brought to the UP-BP differentiation. Unlike BP-I who were low on neuroticism, both BP-II and UP scored high on this measure: yet, in the case of BP-II high neuroticism was largely due to mood lability, in UP it reflected subdepressive traits. We used self-rated personality measures, a possible limitation generic to

Analytical analysis of solar thermal collector with glass and Fresnel lens glazing

Science.gov (United States)

Zulkifle, Idris; Ruslan, Mohd Hafidz Hj; Othman, Mohd Yusof Hj; Ibarahim, Zahari

2018-04-01

Solar thermal collector is a system that converts solar radiation to heat. The heat will raise the temperature higher than the ambient temperature. Absorber and glazing are two important components in order to increase the temperature of the collector. The thermal absorber will release heat by convection and as radiation to the surrounding. These losses will be reduced by glazing. Other than that, glazing is beneficial for protecting the collector from dust and water. This study discusses about modelling of solar thermal collector effects of different mass flow rates with different glazing for V-groove flat plate solar collectors. The glazing used was the glass and linear Fresnel lens. Concentration ratio in this modelling was 1.3 for 0.1m solar collector thickness. Results show that solar collectors with linear Fresnel lens has the highest efficiency value of 71.18% compared to solar collectors with glass which has efficiency 54.10% with same operation conditions.

Electrical properties of CdS/CdTe heterojunctions

International Nuclear Information System (INIS)

Chu, T.L.; Chu, S.S.; Ang, S.T.

1988-01-01

The electrical properties of n-CdS/p-CdTe heterojunctions depend strongly on the cleanliness of the interface region. In this work, CdTe films were deposited on CdS/glass substrates by close-spaced sublimation (CSS) under various conditions. The dark current-voltage characteristics of the resulting heterojunctions were measured over a wide temperature range, and the capacitance-voltage characteristics were measured in the dark and under illumination. When the CdS surface is in situ cleaned prior to the deposition of the CdTe film, the current transport across the junction is controlled by a thermally activated process. Tunneling makes an important contribution to the interface recombination at temperatures below room temperature when the in situ cleaning of CdS is not used. The dark capacitance of CdS/CdTe heterojunctions prepared with in situ etching is essentially independent of the reverse bias due to intrinsic interface states. Under white light illumination, the 1/C 2 vs V relation is nearly linear. The CdS/CdTe heterojunctions without in situ cleaning showed different 1/C 2 vs V relations due to higher density of interface states. The in situ cleaning also has pronounced effects on the frequency dependence of dark and illuminated capacitances. Using the in situ cleaning technique, solar cells of about 1 cm 2 area have achieved an AM 1.5 (global) efficiency of about 10.5%

Strategies for increasing the efficiency of heterojunction organic solar cells: material selection and device architecture.

Science.gov (United States)

Heremans, Paul; Cheyns, David; Rand, Barry P

2009-11-17

Thin-film blends or bilayers of donor- and acceptor-type organic semiconductors form the core of heterojunction organic photovoltaic cells. Researchers measure the quality of photovoltaic cells based on their power conversion efficiency, the ratio of the electrical power that can be generated versus the power of incident solar radiation. The efficiency of organic solar cells has increased steadily in the last decade, currently reaching up to 6%. Understanding and combating the various loss mechanisms that occur in processes from optical excitation to charge collection should lead to efficiencies on the order of 10% in the near future. In organic heterojunction solar cells, the generation of photocurrent is a cascade of four steps: generation of excitons (electrically neutral bound electron-hole pairs) by photon absorption, diffusion of excitons to the heterojunction, dissociation of the excitons into free charge carriers, and transport of these carriers to the contacts. In this Account, we review our recent contributions to the understanding of the mechanisms that govern these steps. Starting from archetype donor-acceptor systems of planar small-molecule heterojunctions and solution-processed bulk heterojunctions, we outline our search for alternative materials and device architectures. We show that non-planar phthalocynanines have appealing absorption characteristics but also have reduced charge carrier transport. As a result, the donor layer needs to be ultrathin, and all layers of the device have to be tuned to account for optical interference effects. Using these optimization techniques, we illustrate cells with 3.1% efficiency for the non-planar chloroboron subphthalocyanine donor. Molecules offering a better compromise between absorption and carrier mobility should allow for further improvements. We also propose a method for increasing the exciton diffusion length by converting singlet excitons into long-lived triplets. By doping a polymer with a

Optoelectrical Properties of a Heterojunction with Amorphous InGaZnO Film on n-Silicon Substrate

Science.gov (United States)

Jiang, D. L.; Ma, X. Z.; Li, L.; Xu, Z. K.

2017-10-01

An a-IGZO/ n-Si heterojunction device has been fabricated at room temperature by depositing amorphous InGaZnO (a-IGZO) film on n-type silicon substrate by plasma-assisted pulsed laser deposition and its optoelectrical properties studied in detail. The heterojunction showed distinct rectifying characteristic with rectification ratio of 1.93 × 103 at ±2 V bias and reverse leakage current density of 1.6 × 10-6 A cm-2 at -2 V bias. More interestingly, the heterojunction not only showed the characteristic of unbiased photoresponse, but could also detect either ultraviolet or ultraviolet-visible light by simply changing the polarity of the bias applied to the heterojunction. The variable photoresponse phenomenon and the charge transport mechanisms in the heterojunction are explained based on the energy band diagram of the heterojunction.

Growth dynamics of SiGe nanowires by the Vapour Liquid Solid method and its impact on SiGe/Si axial heterojunction abruptness.

Science.gov (United States)

Pura, Jose Luis; Periwal, Priyanka; Baron, Thierry; Jimenez, Juan

2018-06-05

The Vapour Liquid Solid (VLS) method is by far the most extended procedure for bottom-up nanowire growth. This method also allows for the manufacture of nanowire axial heterojunctions in a straightforward way. To do this, during the growth process the precursor gases are switched on/off to obtain the desired change in the nanowire composition. Using this technique axially heterostructured nanowires can be grown, which are crucial for the fabrication of electronic and optoelectronic devices. SiGe/Si nanowires are compatible with Complementary Metal Oxide Semiconductor (CMOS) technology, this improves their versatility and the possibility of integration with the current electronic technologies. Abrupt heterointerfaces are fundamental for the development and correct operation of electronic and optoelectronic devices. Unfortunately, VLS growth of SiGe/Si heterojunctions does not provide abrupt transitions because of the high solubility of group IV semiconductors in Au, with the corresponding reservoir effect that precludes the growth of sharp interfaces. In this work, we studied the growth dynamics of SiGe/Si heterojunctions based on already developed models for VLS growth. A composition map of the Si-Ge-Au liquid alloy is proposed to better understand the impact of the growing conditions on the nanowire growth process and the heterojunction formation. The solution of our model provides heterojunction profiles in good agreement with experimental measurements. Finally, the in-depth study of the composition map provides a practical approach to reduce drastically the heterojunction abruptness by reducing the Si and Ge concentrations in the catalyst droplet. This converges with previous approaches that use catalysts aiming to reduce the solubility of the atomic species. This analysis opens new paths to reduce the heterojunction abruptness using Au catalysts, but the model can be naturally extended to other catalysts and semiconductors. © 2018 IOP Publishing Ltd.

Standarized performance tests of collectors of solar thermal energy: A steel flat-plate collector with two transparent covers and a proprietary coating

Science.gov (United States)

1976-01-01

Basic test results of a flat-plate solar collector whose performance was determined in the NASA-Lewis solar simulator are given. The collector was tested over ranges of inlet temperature and flux level.

Monolayer MoS2 heterojunction solar cells

KAUST Repository

Tsai, Menglin

2014-08-26

We realized photovoltaic operation in large-scale MoS2 monolayers by the formation of a type-II heterojunction with p-Si. The MoS 2 monolayer introduces a built-in electric field near the interface between MoS2 and p-Si to help photogenerated carrier separation. Such a heterojunction photovoltaic device achieves a power conversion efficiency of 5.23%, which is the highest efficiency among all monolayer transition-metal dichalcogenide-based solar cells. The demonstrated results of monolayer MoS 2/Si-based solar cells hold the promise for integration of 2D materials with commercially available Si-based electronics in highly efficient devices. © 2014 American Chemical Society.

Glycogen synthase kinase-3β in patients with bipolar I disorder

DEFF Research Database (Denmark)

Jacoby, Anne S; Munkholm, Klaus; Vinberg, Maj

2016-01-01

OBJECTIVES: The enzyme glycogen synthase kinase-3β (GSK3β) is involved in the mechanisms of action of lithium and may play a role in relation to affective states in bipolar disorder. The objectives of the present study were to compare the activity of GSK-3β (measured as levels of phosphorylated GSK......-3β [p-GSK-3β]) between patients with bipolar disorder in the euthymic state and healthy control subjects, and to investigate whether GSK-3β activity varies with affective states in patients with bipolar I disorder. METHODS: In a prospective 6-12-month follow-up study, we investigated state......-specific, intraindividual alterations in the activity of GSK-3β in 60 patients with bipolar I disorder with an acute severe manic index episode and in subsequent euthymic, depressive and manic states and compared this with repeated measurements in healthy control subjects. Data were analyzed using linear mixed...

Progressive neurostructural changes in adolescent and adult patients with bipolar disorder.

Science.gov (United States)

Lisy, Megan E; Jarvis, Kelly B; DelBello, Melissa P; Mills, Neil P; Weber, Wade A; Fleck, David; Strakowski, Stephen M; Adler, Caleb M

2011-06-01

Several lines of evidence suggest that bipolar disorder is associated with progressive changes in gray matter volume (GMV), particularly in brain structures involved in emotional regulation and expression. The majority of these studies however, have been cross-sectional in nature. In this study we compared baseline and follow-up scans in groups of bipolar disorder and healthy subjects. We hypothesized bipolar disorder subjects would demonstrate significant GMV changes over time. A total of 58 bipolar disorder and 48 healthy subjects participated in structural magnetic resonance imaging (MRI). Subjects were rescanned 3-34 months after their baseline MRI. MRI images were segmented, normalized to standard stereotactic space, and compared voxel-by-voxel using statistical parametrical mapping software (SPM2). A model was developed to investigate differences in GMV at baseline, and associated with time and episodes, as well as in comparison to healthy subjects. We observed increases in GMV in bipolar disorder subjects across several brain regions at baseline and over time, including portions of the prefrontal cortex as well as limbic and subcortical structures. Time-related changes differed to some degree between adolescent and adult bipolar disorder subjects. The interval between scans positively correlated with GMV increases in bipolar disorder subjects in portions of the prefrontal cortex, and both illness duration and number of depressive episodes were associated with increased GMV in subcortical and limbic structures. Our findings support suggestions that widely observed progressive neurofunctional changes in bipolar disorder patients may be related to structural brain abnormalities in anterior limbic structures. Abnormalities largely involve regions previously noted to be integral to emotional expression and regulation, and appear to vary by age. © 2011 John Wiley and Sons A/S.

Photosensitive Ox/GaAs heterojunctions: Creation and properties

Energy Technology Data Exchange (ETDEWEB)

Rud' , V. Yu. [St. Petersburg State Polytechnical University (Russian Federation); Rud' , Yu. V., E-mail: yuryrud@mail.ioffe.ru; Terukov, E. I.; Ushakova, T. N. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

2012-06-15

A method for the thermal oxidation of GaAs crystals in air is suggested and the first photosensitive Ox/n-GaAs heterojunctions, where Ox is a native oxide, are fabricated. The steady current-voltage characteristics and spectra of relative quantum efficiency of the new structures are studied. The features of the spectra of photoactive absorption of the obtained heterojunctions are discussed. The potential of using vacuumfree thermal oxidation of the GaAs crystals in air to fabricate broadband heterophotoconverters of optical radiation on their basis is established.

Combined solar collector and energy storage system

Science.gov (United States)

Jensen, R. N. (Inventor)

1980-01-01

A combined solar energy collector, fluid chiller and energy storage system is disclosed. A movable interior insulated panel in a storage tank is positionable flush against the storage tank wall to insulate the tank for energy storage. The movable interior insulated panel is alternately positionable to form a solar collector or fluid chiller through which the fluid flows by natural circulation.

Conduction band offset at the InN/GaN heterojunction

International Nuclear Information System (INIS)

Wang Kejia; Lian Chuanxin; Su Ning; Jena, Debdeep; Timler, John

2007-01-01

The conduction-band offset between GaN and InN is experimentally determined. InN/n-type GaN isotype heterojunctions grown by molecular beam epitaxy are observed to exhibit Schottky-junction like behavior based on rectifying vertical current flow. From capacitance-voltage measurements on the heterojunction, the Schottky barrier height is found to be ∼0.94 eV. The photocurrent spectroscopy measurement by backside illumination reveals an energy barrier height of 0.95 eV across the heterojunction, consistent with the capacitance measurement. By combining electrical transport, capacitance-voltage, and photocurrent spectroscopy measurement results, the conduction band offset between InN and GaN is estimated to be ΔE C =1.68±0.1 eV

Autologous Chondrocyte Implantation for Bipolar Chondral Lesions in the Tibiofemoral Compartment.

Science.gov (United States)

Ogura, Takahiro; Bryant, Tim; Mosier, Brian A; Minas, Tom

2018-05-01

Treating bipolar chondral lesions in the tibiofemoral (TF) compartment with cartilage repair procedures is challenging, and a suitable treatment remains unclear. To evaluate clinical outcomes after autologous chondrocyte implantation (ACI) for the treatment of bipolar chondral lesions in the TF compartment. Case series; Level of evidence, 4. We evaluated 57 patients who underwent ACI for the treatment of symptomatic bipolar chondral lesions in the TF compartment by a single surgeon between October 1995 and June 2014. One patient did not return for follow-up. Thus, 56 patients (58 knees) were included with a minimum of 2 years' follow-up. A mean of 3.1 lesions per knee were treated, representing a mean total surface area of 16.1 cm 2 (range, 3.2-44.5 cm 2 ) per knee. Bipolar lesions were present in the medial compartment (32 knees) and in the lateral compartment (26 knees). Patients were evaluated with the modified Cincinnati Knee Rating Scale, visual analog scale for pain, Western Ontario and McMaster Universities Osteoarthritis Index, and Short Form-36. Patients also answered questions regarding self-rated knee function and satisfaction with the procedure. Standard radiographs were evaluated with the Kellgren-Lawrence grading system. The survival rate was 80% at 5 years and 76% at 10 years. A significantly better survival rate was found in patients with the use of a collagen membrane than periosteum (97% vs 61% at 5 years, respectively; P = .0014). Of 46 knees with retained grafts, all functional scores significantly improved postoperatively, with a very high satisfaction rate (91%) at a mean of 8.3 ± 5.1 years (range, 2-20 years) after ACI. At last follow-up, 24 of 46 successful knees were radiographically assessed (mean, 5.5 ± 4.0 years [range, 2.0-18.7 years]) and showed no significant osteoarthritis progression ( P = .3173). Outcomes for 12 patients were considered as failures at a mean of 4.1 years. Of these, 9 patients were converted to partial or total

Recent progress in terrestrial photovoltaic collector technology

Science.gov (United States)

Ferber, R. R.

1982-01-01

The U.S. Photovoltaic Research and Development Program has the objective to develop the technology necessary to foster widespread grid-competitive electric power generation by the late 1980s. The flat-plate and the concentrator collector activities form the nucleus of the program. The project is concerned with the refining of silicon, silicon sheet production, solar cell processing and fabrication, encapsulation materials development, and collector design and production. The Large-Area Silicon Sheet Task has the objective to develop and demonstrate the feasibility of several methods for producing large area silicon sheet material suitable for fabricating low-cost, high-efficiency solar cells. It is expected that a variety of economic flat-plate and concentrator collectors will become commercially available for grid-connected applications.

Design of a collector shape for uniform flow distribution in microchannels

International Nuclear Information System (INIS)

Siddique, Ayyaz; Agrawal, Amit; Saha, Sandip K; Medhi, Bhaskar J; Singh, Anugrah

2017-01-01

The focus of this study is the design of a collector with the objective of achieving uniform flow in multiple parallel microchannels. This objective is achieved by understanding the limitations of current designs and a novel design is proposed, which is further carefully optimized. The existing collector shape considered is U-type, which is investigated numerically. The creation of a stagnation zone, growth of a boundary layer along the collector wall and low/high velocity zones in the collector are identified as the prime causes of flow maldistribution. A novel design, a dumbbell shape collector, is proposed to overcome the limitations of the earlier designs. The dumbbell shape is evaluated quantitatively and is found to perform better than all existing shapes. This dumbbell shape collector provides a uniform flow distribution with less than 0.4% relative difference from the average flow rate in different channels, which is substantially better than existing collectors with 2.3% relative difference from the average flow rate for Re ch   =  32. The uniformity is further confirmed using micro-particle image velocimetry measurements. The dumbbell shape collector is generalized and optimized to cater to heat sinks of different dimensions and to broaden its applicability in both micro and macro dimensions. (paper)

Hybrid van der Waals p-n Heterojunctions based on SnO and 2D MoS2

KAUST Repository

Wang, Zhenwei; He, Xin; Zhang, Xixiang; Alshareef, Husam N.

2016-01-01

A p-type oxide/2D hybrid van der Waals p-n heterojunction is demonstrated for the first time between SnO (tin monoxide) (the p-type oxide) and 2D MoS2 (molybdenum disulfide), showing an ideality factor of 2 and rectification ratio up to 10

«Desire is everything». Desires, dreams, obsessions of collectors and antiquarians

Directory of Open Access Journals (Sweden)

Beatrice Laghezza

2013-06-01

Full Text Available The aim of this essay is to intersect the figures of the collector and the antiquarian with the dynamics of desire, and identify the possible connections between the three themes. Therefore, a thematic and comparative approach was chosen, while the sample text were drawn from the Italian literature of the late nineteenth and twentieth centuries. The textual analysis will reveal the various desires moving collectors and antiquarians in search of the items that make up their collections: greed, pathological need of wealth, fantasies of martyrdom, love, ambition to excel, dreams of omnipotence, libido, jealousy, Illusion of immortality, attraction to the perverse, flâneuristic curiosity. But at the top of this list there is undoubtedly the desire to listen to literature’s description of life.

Project 'Colored solar collectors' - Annual report 2004

Energy Technology Data Exchange (ETDEWEB)

Schueler, A.; Chambrier, E. De; Roecker, Ch.; Scartezzini, J.-L.

2004-12-15

The architectural integration of thermal solar collectors into buildings is often limited by their black color, and the visibility of tubes and corrugations of the absorber sheets. A certain freedom in color choice would be desirable, but the colored appearance should not cause excessive performance degradation. Multilayered thin film interference filters on the collector glazing can produce a colored reflection, hiding the corrugated metal sheet, while transmitting the non-reflected radiation entirely to the absorber. These interference filters are designed and optimized by numerical simulation and shall be manufactured by the sol-gel dip-coating process. The proposed colored glazed solar collectors will be ideally suited for architectural integration into buildings, e.g. as solar active glass facades. The sol-gel fabrication of interference stacks of up to five layers of silicon and titanium oxide films could be demonstrated in the laboratory, in the first step on microscope slides. Optical measurements are used to determine film thicknesses and optical constants of the individual layers, and to measure color coordinates and solar transmission for the multilayer stacks. The solar transmission of such samples can be improved by titanium silicon mixed oxides, which could have been synthesized by the sol-gel method. Hereby the compatibility problems of the originally used solution have been solved, and the refractive index of the resulting mixed oxide can be perfectly controlled by tuning the atomic concentration ratio of silicon and titanium. One of the main technical risks is related to the fact that for a convincing demonstration of the idea high quality coatings are absolutely necessary. Therefore, visible defects induced during the dip-coating process by dust particles in the atmosphere or in the used solutions must be imperatively avoided, as well as thickness variations due to vibrations. After optimizing various aspects of sample preparation, processing and

Trap-mediated electronic transport properties of gate-tunable pentacene/MoS2 p-n heterojunction diodes.

Science.gov (United States)

Kim, Jae-Keun; Cho, Kyungjune; Kim, Tae-Young; Pak, Jinsu; Jang, Jingon; Song, Younggul; Kim, Youngrok; Choi, Barbara Yuri; Chung, Seungjun; Hong, Woong-Ki; Lee, Takhee

2016-11-10

We investigated the trap-mediated electronic transport properties of pentacene/molybdenum disulphide (MoS 2 ) p-n heterojunction devices. We observed that the hybrid p-n heterojunctions were gate-tunable and were strongly affected by trap-assisted tunnelling through the van der Waals gap at the heterojunction interfaces between MoS 2 and pentacene. The pentacene/MoS 2 p-n heterojunction diodes had gate-tunable high ideality factor, which resulted from trap-mediated conduction nature of devices. From the temperature-variable current-voltage measurement, a space-charge-limited conduction and a variable range hopping conduction at a low temperature were suggested as the gate-tunable charge transport characteristics of these hybrid p-n heterojunctions. Our study provides a better understanding of the trap-mediated electronic transport properties in organic/2-dimensional material hybrid heterojunction devices.

Dynamics and control of a solar collector system for near Earth object deflection

International Nuclear Information System (INIS)

Gong Shenping; Li Junfeng; Gao Yunfeng

2011-01-01

A solar collector system is a possible method using solar energy to deflect Earth-threatening near-Earth objects. We investigate the dynamics and control of a solar collector system including a main collector (MC) and secondary collector (SC). The MC is used to collect the sunlight to its focal point, where the SC is placed and directs the collected light to an asteroid. Both the relative position and attitude of the two collectors should be accurately controlled to achieve the desired optical path. First, the dynamical equation of the relative motion of the two collectors in the vicinity of the asteroid is modeled. Secondly, the nonlinear sliding-mode method is employed to design a control law to achieve the desired configuration of the two collectors. Finally, the deflection capability of this solar collector system is compared with those of the gravitational tractor and solar sail gravitational tractor. The results show that the solar collector is much more efficient with respect to deflection capability.

A heterojunction photocatalyst composed of zinc rhodium oxide, single crystal-derived bismuth vanadium oxide, and silver for overall pure-water splitting under visible light up to 740 nm.

Science.gov (United States)

Kobayashi, Ryoya; Takashima, Toshihiro; Tanigawa, Satoshi; Takeuchi, Shugo; Ohtani, Bunsho; Irie, Hiroshi

2016-10-12

We recently reported the synthesis of a solid-state heterojunction photocatalyst consisting of zinc rhodium oxide (ZnRh 2 O 4 ) and bismuth vanadium oxide (Bi 4 V 2 O 11 ), which functioned as hydrogen (H 2 ) and oxygen (O 2 ) evolution photocatalysts, respectively, connected with silver (Ag). Polycrystalline Bi 4 V 2 O 11 (p-Bi 4 V 2 O 11 ) powders were utilized to form ZnRh 2 O 4 /Ag/p-Bi 4 V 2 O 11 , which was able to photocatalyze overall pure-water splitting under red-light irradiation with a wavelength of 700 nm (R. Kobayashi et al., J. Mater. Chem. A, 2016, 4, 3061). In the present study, we replaced p-Bi 4 V 2 O 11 with a powder obtained by pulverizing single crystals of Bi 4 V 2 O 11 (s-Bi 4 V 2 O 11 ) to form ZnRh 2 O 4 /Ag/s-Bi 4 V 2 O 11 , and demonstrated that this heterojunction photocatalyst had enhanced water-splitting activity. In addition, ZnRh 2 O 4 /Ag/s-Bi 4 V 2 O 11 was able to utilize nearly the entire range of visible light up to a wavelength of 740 nm. These properties were attributable to the higher O 2 evolution activity of s-Bi 4 V 2 O 11 .

Axial motion of collector plasma in a relativistic backward wave oscillator

Energy Technology Data Exchange (ETDEWEB)

Xiao, Renzhen; Chen, Changhua; Deng, Yuqun; Cao, Yibing; Sun, Jun; Li, Jiawei [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi' an 710024 (China)

2016-06-15

In this paper, it is proposed that plasma formed at the collector may drift back to the cathode and cause pulse shortening of the relativistic backward wave oscillator. Theoretical analysis shows that the axial drift velocity of plasma ions can be up to 5 mm/ns due to the presence of space charge potential provided by an intense relativistic electron beam. Particle-in-cell simulations indicate that the plasma electrons are initially trapped around the collector surface. With the accumulation of the plasma ions, a large electrostatic field forms and drives the plasma electrons to overcome the space charge potential and enter the beam-wave interaction region along the magnetic field lines. As a result, the beam current modulation is disturbed and the output microwave power falls rapidly. The plasma ions move in the beam-wave interaction region with an average axial velocity of 5–8 mm/ns. After the plasma ions reach the diode region, the emitted current at the cathode rises due to the charge neutralizations by the ions. The impedance collapse leads to further decrease of the microwave power. In experiments, when the diode voltage and beam current were 850 kV and 9.2 kA, and the collector radius was 2.15 cm, the output microwave power was 2.4 GW with a pulse width of less than 20 ns. The ion drift velocity was estimated to be about 5 mm/ns. After an improved collector with 3.35 cm radius was adopted, the pulse width was prolonged to more than 30 ns.

Thermo-ecological optimization of a solar collector

International Nuclear Information System (INIS)

Szargut, J.; Stanek, W.

2007-01-01

The depletion of non-renewable natural exergy resources (the thermo-ecological cost) has been accepted as the objective function for thermo-ecological optimization. Its general formulation has been cited. A detailed form of the objective function has been formulated for a solar collector producing hot water for household needs. The following design parameters have been accepted as the decision variables: the collector area per unit of the heat demand, the diameter of collector pipes, the distance of the pipe axes in the collector plate. The design parameters of the internal installation (the pipes, the hot water receiver) have not been taken into account, because they are very individual. The accumulation ability of hot water comprising one day has been assumed. The objective function contains the following components: the thermo-ecological cost of copper plate, copper pipes, glass plate, steel box, thermal insulation, heat transfer liquid, electricity for driving the pump of liquid, fuel for the peak boiler. The duration curves of the flux of solar radiation and absorbed heat have been elaborated according to meteorological data and used in the calculations. The objective function for economic optimization may have a similar form, only the cost values would be different

Solar collector wall with active curtain system; Lasikatteinen massiivienen aurinkokeraeaejaeseinae

Energy Technology Data Exchange (ETDEWEB)

Ojanen, T.; Heimonen, I. [VTT Building Technology, Espoo (Finland). Building Physics, Building Services and Fire Technology

1998-12-01

Integration of solar collector into the building envelope structure brings many advantages. The disadvantage of a passive solar collector wall is that its thermal performance can not be controlled, which may cause temporary overheating and low thermal efficiency of the collector. The thermal performance of the collector wall can be improved by using controllable, active collector systems. In this paper a solar collector wall with a controllable curtain between the transparent and absorption layers is investigated. The curtain is made of several low-emissivity foil layers, which ensures low radiation heat transfer through the curtain. The curtain decreases the heat losses out from the collector wall and it improves the U-value of the wall. The curtain is used when the solar radiation intensity to the wall is not high enough or when the wall needs protection against overheating during warm weather conditions. The materials and building components used in the collector wall, except those of the curtain, are ordinary in buildings. The transparent layer can be made by using normal glazing technology and the thermal storage layer can be made out of brick or similar material. The solar energy gains through the glazing can be utilised better than in passive systems, because the curtain provides the wall with high thermal resistance outside the solar radiation periods. The thermal performance of the collector wall was studied experimentally using a Hot-Box apparatus equipped with a solar lamp. Numerical simulations were carried out to study the yearly performance of the collector wall under real climate conditions. The objectives were to determine the thermal performance of the collector wall and to study how to optimise the use of solar radiation in this system. When the curtain with high thermal resistance is used actively, the temperature level of the thermal storage layer in the wall is relatively high also during dark periods and the heat losses out from the storage

Interface states in stressed semiconductor heterojunction with antiferromagnetic ordering

International Nuclear Information System (INIS)

Kantser, V.G.

1995-08-01

The stressed heterojunctions with antiferromagnetic ordering in which the constituents have opposite band edge symmetry and their gaps have opposite signs have been investigated. The interface states have been shown to appear in these heterojunctions and they are spin-split. As a result if the Fermi level gets into one of the interface bands then it leads to magnetic ordering in the interface plane. That is if the interface magnetization effect can be observed. (author). 14 refs, 2 figs

Investigation of a hybrid PVT air collector system

Science.gov (United States)

Haddad, S.; Touafek, K.; Mordjaoui, M.; Khelifa, A.; Tabet, I.

2017-02-01

The photovoltaic thermal hybrid (PVT) collectors, which simultaneously produce electricity and heat, are an alternative to photovoltaic modules and thermal collectors installed separately. Indeed, the heat extracted from the solar cell is used to heat water or air, thereby cooling the cell, and thus increasing its energy efficiency. This paper deals with a hybrid PVT air collector in which a new design has been proposed and tested. Its principle is based on the return of the preheating air to a second heating. The air thus passes twice under the solar cells before being evacuated to the outside of the collector (for space heating). The system is modular and expandable to cover large spaces to be heated. The experimental results of this novel design are presented and discussed under both normal and forced circulation. This technique of air return shows favorable results in terms of the quality of the heated air and electric power generation.

Interface magnetization effect in heterojunctions based on semimagnetic compounds

International Nuclear Information System (INIS)

Malkova, N.

1998-07-01

The electronic states of stressed heterojunctions formed from narrow-gap semimagnetic semiconductors showing antiferromagnetic ordering are studies. The model Hamiltonian is constructed in the framework of the two-band envelope function approximation including far-band corrections. Heterojunctions both with normal and inverted band arrangements in the initial semiconductors are investigated. The interface Tamm-like states have been shown recently toe appear in these heterojunctions and they are spin-split with the magnetic axis perpendicular to the interface plane. The effect of far-band corrections is shown to be conditioned by the mutual movement of the constituent bands, resulting in changes and in some cases in full disappearance of the energy interval in which the interface state exists. The interface magnetization effect is expected when the Fermi level lies in one of the spin-polarized interface bands. Using the appropriate parameters, the value of the relative interface magnetization is calculated. (author)

Large rectification magnetoresistance in nonmagnetic Al/Ge/Al heterojunctions.

Science.gov (United States)

Zhang, Kun; Li, Huan-Huan; Grünberg, Peter; Li, Qiang; Ye, Sheng-Tao; Tian, Yu-Feng; Yan, Shi-Shen; Lin, Zhao-Jun; Kang, Shi-Shou; Chen, Yan-Xue; Liu, Guo-Lei; Mei, Liang-Mo

2015-09-21

Magnetoresistance and rectification are two fundamental physical properties of heterojunctions and respectively have wide applications in spintronics devices. Being different from the well known various magnetoresistance effects, here we report a brand new large magnetoresistance that can be regarded as rectification magnetoresistance: the application of a pure small sinusoidal alternating-current to the nonmagnetic Al/Ge Schottky heterojunctions can generate a significant direct-current voltage, and this rectification voltage strongly varies with the external magnetic field. We find that the rectification magnetoresistance in Al/Ge Schottky heterojunctions is as large as 250% at room temperature, which is greatly enhanced as compared with the conventional magnetoresistance of 70%. The findings of rectification magnetoresistance open the way to the new nonmagnetic Ge-based spintronics devices of large rectification magnetoresistance at ambient temperature under the alternating-current due to the simultaneous implementation of the rectification and magnetoresistance in the same devices.

Bipolar Disorder and Cancer

Directory of Open Access Journals (Sweden)

Sermin Kesebir

2012-06-01

Full Text Available 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 chromosome 13, breast cancer, retinoblastoma, chronic Iymphocytic leukemia genes with B cells, dopamin loci of bipolar disorder are found together. Among bipolar and healthy individuals, an increase risk of breast cancer in female cases has been resported. On the other hand, psychosocial factors that affect stress and response to stress itself may be important variables in prognosis and progression of different cancer types. During the course of many cancer types –especially brain tumors- and during treatment of chemotherapeutic agents, bipolar symptomatology may appear. In this article, it is reviewed with relevant literature that whether an etiological relation between bipolar disorder and cancer exist and how both diseases affect each other's course and treatment.

Monocyte activation, brain-derived neurotrophic factor (BDNF), and S100B in bipolar offspring: a follow-up study from adolescence into adulthood.

Science.gov (United States)

Mesman, Esther; Hillegers, Manon Hj; Ambree, Oliver; Arolt, Volker; Nolen, Willem A; Drexhage, Hemmo A

2015-02-01

There is increasing evidence that both immune and neurochemical alterations are involved in the pathogenesis of bipolar disorder; however, their precise role remains unclear. In this study, we aimed to evaluate neuro-immune changes in a prospective study on children of patients with bipolar disorder. Bipolar offspring, from the prospective Dutch bipolar offspring study (n = 140), were evaluated cross-sectionally within a longitudinal context at adolescence, young adulthood, and adulthood. We examined the expression of 44 inflammation-related genes in monocytes, the cytokines pentraxin 3 (PTX3), chemokine ligand 2 (CCL2), and interleukin-1β (IL-1β), and brain-derived neurotrophic factor (BDNF) and S100 calcium binding protein B (S100B) in the serum of bipolar offspring and healthy controls. During adolescence, bipolar offspring showed increased inflammatory gene expression in monocytes, high serum PTX3 levels, but normal CCL2 levels. BDNF levels were decreased, while S100B levels were normal. During young adulthood, monocyte activation remained, although to a lesser degree. Serum PTX3 levels remained high, and signs of monocyte migration became apparent through increased CCL2 levels. BDNF and S100B levels were not measured. At adulthood, circulating monocytes had lost their activation state, but CCL2 levels remained increased. Both BDNF and S100B were now increased. Abnormalities were independent of psychopathology state at all stages. This study suggests an aberrant neuro-immune state in bipolar offspring, which followed a dynamic course from adolescence into adulthood and was present irrespective of lifetime or future mood disorders. We therefore assumed that the aberrant neuro-immune state reflects a general state of vulnerability for mood disorders rather than being of direct predictive value. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Self-Aligned van der Waals Heterojunction Diodes and Transistors.

Science.gov (United States)

Sangwan, Vinod K; Beck, Megan E; Henning, Alex; Luo, Jiajia; Bergeron, Hadallia; Kang, Junmo; Balla, Itamar; Inbar, Hadass; Lauhon, Lincoln J; Hersam, Mark C

2018-02-14

A general self-aligned fabrication scheme is reported here for a diverse class of electronic devices based on van der Waals materials and heterojunctions. In particular, self-alignment enables the fabrication of source-gated transistors in monolayer MoS 2 with near-ideal current saturation characteristics and channel lengths down to 135 nm. Furthermore, self-alignment of van der Waals p-n heterojunction diodes achieves complete electrostatic control of both the p-type and n-type constituent semiconductors in a dual-gated geometry, resulting in gate-tunable mean and variance of antiambipolar Gaussian characteristics. Through finite-element device simulations, the operating principles of source-gated transistors and dual-gated antiambipolar devices are elucidated, thus providing design rules for additional devices that employ self-aligned geometries. For example, the versatility of this scheme is demonstrated via contact-doped MoS 2 homojunction diodes and mixed-dimensional heterojunctions based on organic semiconductors. The scalability of this approach is also shown by fabricating self-aligned short-channel transistors with subdiffraction channel lengths in the range of 150-800 nm using photolithography on large-area MoS 2 films grown by chemical vapor deposition. Overall, this self-aligned fabrication method represents an important step toward the scalable integration of van der Waals heterojunction devices into more sophisticated circuits and systems.

Six years of evidence-based adult dissection tonsillectomy with ultrasonic scalpel, bipolar electrocautery, bipolar radiofrequency or 'cold steel' dissection.

Science.gov (United States)

Ragab, S M

2012-10-01

To conduct an adequately powered, prospective, randomised, controlled trial comparing adult dissection tonsillectomy using either ultrasonic scalpel, bipolar electrocautery, bipolar radiofrequency or 'cold steel' dissection. Three hundred patients were randomised into four tonsillectomy technique groups. The operative time, intra-operative bleeding, post-operative pain, tonsillar fossa healing, return to full diet, return to work and post-operative complications were recorded. The bipolar radiofrequency group had a shorter mean operative time. The mean intra-operative blood loss during bipolar radiofrequency tonsillectomy was significantly less compared with cold dissection and ultrasonic scalpel tonsillectomy. Pain scores were significantly higher after bipolar electrocautery tonsillectomy. Patients undergoing bipolar electrocautery tonsillectomy required significantly more days to return to full diet and work. The bipolar electrocautery group showed significantly reduced tonsillar fossa healing during the first and second post-operative weeks. In this adult series, bipolar radiofrequency tonsillectomy was superior to ultrasonic, bipolar electrocautery and cold dissection tonsillectomies. This method combines the advantages of 'hot' and 'cold' tonsillectomy.

Secondary-electron-emission losses in multistage depressed collectors and traveling-wave-tube efficiency improvements with carbon collector electrode surfaces

Science.gov (United States)

Ramins, P.; Ebihara, B. T.

1986-01-01

Secondary-electron-emission losses in multistage depressed collectors (MDC's) and their effects on overall traveling-wave-tube (TWT) efficiency were investigated. Two representative TWT's and several computer-modeled MDC's were used. The experimental techniques provide the measurement of both the TWT overall and the collector efficiencies. The TWT-MDC performance was optimized and measured over a wide range of operating conditions, with geometrically identical collectors, which utilized different electrode surface materials. Comparisons of the performance of copper electrodes to that of various forms of carbon, including pyrolytic and iisotropic graphites, were stressed. The results indicate that: (1) a significant improvement in the TWT overall efficiency was obtained in all cases by the use of carbon, rather than copper electrodes, and (2) that the extent of this efficiency enhancement depended on the characteristics of the TWT, the TWT operating point, the MDC design, and collector voltages. Ion textured graphite was found to be particularly effective in minimizing the secondary-electron-emission losses. Experimental and analytical results, however, indicate that it is at least as important to provide a maximum amount of electrostatic suppression of secondary electrons by proper MDC design. Such suppression, which is obtained by ensuring that a substantial suppressing electric field exists over the regions of the electrodes where most of the current is incident, was found to be very effective. Experimental results indicate that, with proper MDC design and the use of electrode surfaces with low secondary-electron yield, degradation of the collector efficiency can be limited to a few percent.

Amorphous silicon crystalline silicon heterojunction solar cells

CERN Document Server

Fahrner, Wolfgang Rainer

2013-01-01

Amorphous Silicon/Crystalline Silicon Solar Cells deals with some typical properties of heterojunction solar cells, such as their history, the properties and the challenges of the cells, some important measurement tools, some simulation programs and a brief survey of the state of the art, aiming to provide an initial framework in this field and serve as a ready reference for all those interested in the subject. This book helps to "fill in the blanks" on heterojunction solar cells. Readers will receive a comprehensive overview of the principles, structures, processing techniques and the current developmental states of the devices. Prof. Dr. Wolfgang R. Fahrner is a professor at the University of Hagen, Germany and Nanchang University, China.

Low-threshold pure UV electroluminescence from n-ZnO:Al/i-layer/n-GaN heterojunction

International Nuclear Information System (INIS)

Li Songzhan; Fang Guojia; Long Hao; Wang Haoning; Huang Huihui; Mo Xiaoming; Zhao Xingzhong

2012-01-01

Ultraviolet (UV) electroluminescence (EL) of n-ZnO:Al (AZO)/i-layer/n-GaN heterojunctions with different intrinsic layers has been obtained. Rectifying behavior and EL spectra of the heterojunctions are investigated at room temperature. Under positive voltage, a dominant UV emission peak around ∼370 nm is observed for both AZO/i-ZnO/n-GaN and AZO/i-MgO/n-GaN heterojunctions. Nevertheless, the UV emission peak intensity of AZO/i-MgO/n-GaN heterojunction is much stronger than that of AZO/i-ZnO/n-GaN heterojunction at the same voltage. The threshold voltage of AZO/i-MgO/n-GaN heterostructured device is as low as 2.3 V. The difference of EL spectra and the emission mechanism in these devices are discussed. - Highlights: ► UV electroluminescence of n-ZnO:Al/i-layer/n-GaN heterojunctions has been obtained. ► Under positive voltage, a dominant UV emission peak around ∼370 nm is observed for both heterojunctions. ► The UV emission peak intensity of the heterojunction with i-MgO layer is much stronger than that with i-ZnO layer at the same voltage. ► The threshold voltage of n-ZnO:Al/i-MgO/n-GaN heterostructured device is as low as 2.3 V.

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

Science.gov (United States)

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; González-Pinto, Ana; Goldberg, Joseph F.; Yildiz, Ayşegül; 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.; Vázquez, Gustavo; Perlis, Roy H.; Ketter, Terence A.; Cassidy, Frederick; Akiskal, Hagop; Azorin, Jean-Michel; Valentí, Marc; Mazzei, Diego Hidalgo; Lafer, Beny; Kato, Tadafumi; Mazzarini, Lorenzo; Martínez-Aran, Anabel; Parker, Gordon; Souery, Daniel; Özerdem, Ayşegül; 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, Flávio; Vieta, Eduard

2014-01-01

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 on the use of antidepressants in bipolar disorders. Method An expert task force iteratively developed consensus through serial consensus-based revisions using the Delphi method. Initial survey items were based on systematic review of the literature. Subsequent surveys included new or reworded items and items that needed to be rerated. This process resulted in the final ISBD Task Force clinical recommendations on antidepressant use in bipolar disorder. Results There is striking incongruity between the wide use of and the weak evidence base for the efficacy and safety of antidepressant drugs in bipolar disorder. Few well-designed, long-term trials of prophylactic benefits have been conducted, and there is insufficient evidence for treatment benefits with antidepressants combined with mood stabilizers. A major concern is the risk for mood switch to hypomania, mania, and mixed states. Integrating the evidence and the experience of the task force members, a consensus was reached on 12 statements on the use of antidepressants in bipolar disorder. Conclusions Because of limited data, the task force could not make broad statements endorsing antidepressant use but acknowledged that individual bipolar patients may benefit from antidepressants. Regarding safety, serotonin reuptake inhibitors and bupropion may have lower rates of manic switch than tricyclic and tetracyclic antidepressants and norepinephrine-serotonin reuptake inhibitors. The frequency and severity of antidepressant-associated mood elevations appear to be greater in bipolar I than bipolar II disorder. Hence, in bipolar I patients antidepressants should be prescribed only as an adjunct to mood-stabilizing medications

Electrostatically Gated Graphene-Zinc Oxide Nanowire Heterojunction.

Science.gov (United States)

You, Xueqiu; Pak, James Jungho

2015-03-01

This paper presents an electrostatically gated graphene-ZnO nanowire (NW) heterojunction for the purpose of device applications for the first time. A sub-nanometer-thick energy barrier width was formed between a monatomic graphene layer and electrochemically grown ZnO NWs. Because of the narrow energy barrier, electrons can tunnel through the barrier when a voltage is applied across the junction. A near-ohmic current-voltage (I-V) curve was obtained from the graphene-electrochemically grown ZnO NW heterojunction. This near-ohmic contact changed to asymmetric I-V Schottky contact when the samples were exposed to an oxygen environment. It is believed that the adsorbed oxygen atoms or molecules on the ZnO NW surface capture free electrons of the ZnO NWs, thereby creating a depletion region in the ZnO NWs. Consequentially, the electron concentration in the ZnO NWs is dramatically reduced, and the energy barrier width of the graphene-ZnO NW heterojunction increases greatly. This increased energy barrier width reduces the electron tunneling probability, resulting in a typical Schottky contact. By adjusting the back-gate voltage to control the graphene-ZnO NW Schottky energy barrier height, a large modulation on the junction current (on/off ratio of 10(3)) was achieved.

One-dimensional Z-scheme TiO{sub 2}/WO{sub 3}/Pt heterostructures for enhanced hydrogen generation

Energy Technology Data Exchange (ETDEWEB)

Gao, Hongqing [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); State Centre for International Cooperation on Designer Low-carbon and Environmental Materials (SCICDLCEM), Zhengzhou University, Zhengzhou 450001, Henan (China); Zhang, Peng, E-mail: Zhangp@zzu.edu.cn [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); State Centre for International Cooperation on Designer Low-carbon and Environmental Materials (SCICDLCEM), Zhengzhou University, Zhengzhou 450001, Henan (China); Hu, Junhua, E-mail: Hujh@zzu.edu.cn [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); State Centre for International Cooperation on Designer Low-carbon and Environmental Materials (SCICDLCEM), Zhengzhou University, Zhengzhou 450001, Henan (China); Pan, Jimin [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); Fan, Jiajie [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); State Centre for International Cooperation on Designer Low-carbon and Environmental Materials (SCICDLCEM), Zhengzhou University, Zhengzhou 450001, Henan (China); Shao, Guosheng [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); State Centre for International Cooperation on Designer Low-carbon and Environmental Materials (SCICDLCEM), Zhengzhou University, Zhengzhou 450001, Henan (China); Institute for Renewable Energy and Environmental Technologies, University of Bolton, Bolton BL35AB (United Kingdom)

2017-01-01

Graphical abstract: We reported one-dimensional solid-state Z-scheme photosynthetic heterojunction system with Pt nanoparticle as an electron collector and WO{sub 3} as a hole collector, leading to effective charge separation. - Highlights: • The composite nanofibers were fabricated by facile electrospinning technique. • The composite nanofibers exhibited enhanced activity for H{sub 2} evolution. • Enhanced activity is due to the formation of Z-scheme TiO{sub 2}/WO{sub 3}/Pt heterojunction. - Abstract: One-dimensional Z-scheme TiO{sub 2}/WO{sub 3}/Pt heterostructures were fabricated by integrating a facile electrospinning technique and subsequent annealing in air. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and UV–vis diffuse reflectance spectroscopy, were used to characterize the as-fabricated samples. The results showed that the H{sub 2}-generation of the as-fabricated one-dimensional Z-scheme TiO{sub 2}/WO{sub 3}/Pt heterostructures (S2) was greatly enhanced compared with pure TiO{sub 2} nanofibers (S0) and TiO{sub 2}/WO{sub 3} nanofibers (S1). The enhanced photocatalyst activities were mainly attributed to the solid-state Z-scheme photosynthetic heterojunction system with Pt nanoparticle as an electron collector and WO{sub 3} as a hole collector, leading to effective charge separation on these semiconductors, which were evidenced by electrochemical impedance spectroscopy (EIS) and photocurrent analysis.

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

Directory of Open Access Journals (Sweden)

Jones Ian

2009-08-01

Full Text Available 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 The study is an exploratory, individually randomised controlled trial. The intervention known as 'Beating Bipolar' is a psychoeducational programme which is delivered via a novel web-based system. We will recruit 100 patients with a diagnosis of DSM-IV bipolar disorder (including type I and type II currently in clinical remission. The primary outcome is quality of life. This will be compared for those patients who have participated in the psychoeducational programme with those who received treatment as usual. Quality of life will be assessed immediately following the intervention as well as 10 months after randomisation. Secondary outcomes include current depressive and manic symptoms, number of episodes of depression and mania/hypomania experienced during the follow-up period, global functioning, functional impairment and insight. An assessment of costs and a process evaluation will also be conducted which will explore the feasibility and acceptability of the intervention as well as potential barriers to effectiveness. Discussion Bipolar disorder is common, under-recognised and often poorly managed. It is a chronic, life-long, relapsing condition which has an enormous impact on the individual and the economy. This trial will be the first to explore the effectiveness of a novel web-based psychoeducational intervention for patients with bipolar disorder which has potential to be easily rolled out to patients. Trial registration Current Controlled Trials

Tritium separation from light and heavy water by bipolar electrolysis

International Nuclear Information System (INIS)

Ramey, D.W.; Petek, M.; Taylor, R.D.; Kobisk, E.H.; Ramey, J.; Sampson, C.A.

1979-10-01

Use of bipolar electrolysis with countercurrent electrolyte flow to separate hydrogen isotopes was investigated for the removal of tritium from light water effluents or from heavy water moderator. Deuterium-tritium and protium-tritium separation factors occurring on a Pd-25% Ag bipolar electrode were measured to be 2.05 to 2.16 and 11.6 to 12.4 respectively, at current densities between 0.21 and 0.50 A cm -2 , and at 35 to 90 0 C. Current densities up to 0.3 A cm -2 have been achieved in continuous operation, at 80 to 90 0 C, without significant gas formation on the bipolar electrodes. From the measured overvoltage at the bipolar electrodes and the electrolyte conductivity the power consumption per stage was calculated to be 3.0 kwh/kg H 2 O at 0.2 A cm -2 and 5.0 kwh/kg H 2 O at 0.5 A cm -2 current density, compared to 6.4 and 8.0 kwh/kg H 2 O for normal electrolysis. A mathematical model derived for hydrogen isotope separation by bipolar electrolysis, i.e., for a square cascade, accurately describes the results for protium-tritium separation in two laboratory scale, multistage experiments with countercurrent electrolyte flow; the measured tiritum concentration gradient through the cascade agreed with the calculated values

Short-Term Solar Collector Power Forecasting

DEFF Research Database (Denmark)

Bacher, Peder; Madsen, Henrik; Perers, Bengt

2011-01-01

This paper describes a new approach to online forecasting of power output from solar thermal collectors. The method is suited for online forecasting in many applications and in this paper it is applied to predict hourly values of power from a standard single glazed large area flat plate collector...... enabling tracking of changes in the system and in the surrounding conditions, such as decreasing performance due to wear and dirt, and seasonal changes such as leaves on trees. This furthermore facilitates remote monitoring and check of the system....

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

Cognitive vulnerability to bipolar disorder in offspring of parents with bipolar disorder.

Science.gov (United States)

Pavlickova, Hana; Turnbull, Oliver; Bentall, Richard P

2014-11-01

Bipolar disorder is a highly heritable illness, with a positive family history robustly predictive of its onset. It follows that studying biological children of parents with bipolar disorder may provide information about developmental pathways to the disorder. Moreover, such studies may serve as a useful test of theories that attribute a causal role in the development of mood disorders to psychological processes. Psychological style (including self-esteem, coping style with depression, domain-specific risk-taking, sensation-seeking, sensitivity to reward and punishment, and hypomanic personality and cognition) was assessed in 30 offspring of bipolar parents and 30 children of well parents. Parents of both child groups completed identical assessments. Although expected differences between parents with bipolar disorder and well parents were detected (such as low self-esteem, increased rumination, high sensitivity to reward and punishment), offspring of bipolar parents were, as a group, not significantly different from well offspring, apart from a modest trend towards lower adaptive coping. When divided into affected and non-affected subgroups, both groups of index children showed lower novelty-seeking. Only affected index children showed lower self-esteem, increased rumination, sensitivity to punishment, and hypomanic cognitions. Notably, these processes were associated with symptoms of depression. Psychological abnormalities in index offspring were associated with having met diagnostic criteria for psychiatric illnesses and the presence of mood symptoms, rather than preceding them. Implications of the present findings for our understanding of the development of bipolar disorder, as well as for informing early interventions, are discussed. © 2014 The British Psychological Society.

Evaluation of initial collector field performance at the Langley Solar Building Test Facility

Science.gov (United States)

Boyle, R. J.; Knoll, R. H.; Jensen, R. N.

1977-01-01

The thermal performance of the solar collector field for the NASA Langley Solar Building Test Facility is given for October 1976 through January 1977. An 1180 square meter solar collector field with seven collector designs helped to provide hot water for the building heating system and absorption air conditioner. The collectors were arranged in 12 rows with nominally 51 collectors per row. Heat transfer rates for each row are calculated and recorded along with sensor, insolation, and weather data every 5 minutes using a mini-computer. The agreement between the experimental and predicted collector efficiencies was generally within five percentage points.

Development of 12.5 m² Solar Collector Panel for Solar Heating Plants

DEFF Research Database (Denmark)

Vejen, Niels Kristian; Furbo, Simon; Shah, Louise Jivan

2004-01-01

and large solar heating systems. Based on the theoretical findings a prototype of an improved HT solar collector was built and tested side-by-side with the original HT solar collector. The improved HT collector makes use of a changed insulation material, an absorber with improved absorptance and emittance......Theoretical and experimental investigations have elucidated how different changes in the design of the 12.5 m(2) HT flat-plate solar collector from the Danish company ARCON Solvarme A/S influence the solar collector efficiency and the yearly thermal performance. The collector is designed for medium...

Transition-metal impurities in semiconductors and heterojunction band lineups

Science.gov (United States)

Langer, Jerzy M.; Delerue, C.; Lannoo, M.; Heinrich, Helmut

1988-10-01

The validity of a recent proposal that transition-metal impurity levels in semiconductors may serve as a reference in band alignment in semiconductor heterojunctions is positively verified by using the most recent data on band offsets in the following lattice-matched heterojunctions: Ga1-xAlxAs/GaAs, In1-xGaxAsyP1-y/InP, In1-xGaxP/GaAs, and Cd1-xHgxTe/CdTe. The alignment procedure is justified theoretically by showing that transition-metal energy levels are effectively pinned to the average dangling-bond energy level, which serves as the reference level for the heterojunction band alignment. Experimental and theoretical arguments showing that an increasingly popular notion on transition-metal energy-level pinning to the vacuum level is unjustified and must be abandoned in favor of the internal-reference rule proposed recently [J. M. Langer and H. Heinrich, Phys. Rev. Lett. 55, 1414 (1985)] are presented.

Molecular orientation and electronic structure at organic heterojunction interfaces

Energy Technology Data Exchange (ETDEWEB)

Zhong, Shu [Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore (Singapore); Zhong, Jian Qiang; Wee, Andrew T.S. [Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore (Singapore); Chen, Wei, E-mail: phycw@nus.edu.sg [Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore (Singapore); Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore (Singapore); National University of Singapore (Suzhou) Research Institute, Suzhou (China)

2015-10-01

Highlights: • Molecular orientation at the organic heterojunction interfaces. • Energy level alignments at the organic heterojunction interfaces. • Gap-states mediated interfacial energy level alignment. - Abstract: Due to the highly anisotropic nature of π-conjugated molecules, the molecular orientation in organic thin films can significantly affect light absorption, charge transport, energy level alignment (ELA) and hence device performance. Synchrotron-based near-edge X-ray absorption fine structure (NEXAFS) spectroscopy represents a powerful technique for probing molecular orientation. The aim of this review paper is to provide a balanced assessment on the investigation of molecular orientation at the organic–organic heterojunction (OOH) interface by NEXAFS, as well as the gap-states mediated orientation dependent energy level alignment at OOH interfaces. We highlight recent progress in elucidating molecular orientation at OOH interfaces dominated by various interfacial interactions, gap-states controlled orientation dependent energy level alignments at OOH interfaces, and the manipulations of molecular orientation and ELA in OOH.

Theoretical analysis to investigate thermal performance of co-axial heat pipe solar collector

Science.gov (United States)

Azad, E.

2011-12-01

The thermal performance of co-axial heat pipe solar collector which consist of a collector 15 co-axial heat pipes surrounded by a transparent envelope and which heat a fluid flowing through the condenser tubes have been predicted using heat transfer analytical methods. The analysis considers conductive and convective losses and energy transferred to a fluid flowing through the collector condenser tubes. The thermal performances of co-axial heat pipe solar collector is developed and are used to determine the collector efficiency, which is defined as the ratio of heat taken from the water flowing in the condenser tube and the solar radiation striking the collector absorber. The theoretical water outlet temperature and efficiency are compared with experimental results and it shows good agreement between them. The main advantage of this collector is that inclination of collector does not have influence on performance of co-axial heat pipe solar collector therefore it can be positioned at any angle from horizontal to vertical. In high building where the roof area is not enough the co-axial heat pipe solar collectors can be installed on the roof as well as wall of the building. The other advantage is each heat pipe can be topologically disconnected from the manifold.

Theoretical analysis to investigate thermal performance of co-axial heat pipe solar collector

Energy Technology Data Exchange (ETDEWEB)

Azad, E. [Iranian Research Organization for Science and Technology (IROST), Advanced Materials and Renewable Energy Department, Tehran (Iran, Islamic Republic of)

2011-12-15

The thermal performance of co-axial heat pipe solar collector which consist of a collector 15 co-axial heat pipes surrounded by a transparent envelope and which heat a fluid flowing through the condenser tubes have been predicted using heat transfer analytical methods. The analysis considers conductive and convective losses and energy transferred to a fluid flowing through the collector condenser tubes. The thermal performances of co-axial heat pipe solar collector is developed and are used to determine the collector efficiency, which is defined as the ratio of heat taken from the water flowing in the condenser tube and the solar radiation striking the collector absorber. The theoretical water outlet temperature and efficiency are compared with experimental results and it shows good agreement between them. The main advantage of this collector is that inclination of collector does not have influence on performance of co-axial heat pipe solar collector therefore it can be positioned at any angle from horizontal to vertical. In high building where the roof area is not enough the co-axial heat pipe solar collectors can be installed on the roof as well as wall of the building. The other advantage is each heat pipe can be topologically disconnected from the manifold. (orig.)

Impact of irritability: a 2-year observational study of outpatients with bipolar I or schizoaffective disorder.

Science.gov (United States)

Berk, Lesley; Hallam, Karen T; Venugopal, Kamalesh; Lewis, Andrew James; Austin, David W; Kulkarni, Jayashri; Dodd, Seetal; de Castella, Anthony; Fitzgerald, Paul B; Berk, Michael

2017-05-01

Many people experience irritability when manic, hypomanic, or depressed, yet its impact on illness severity and quality of life in bipolar and schizoaffective disorders is poorly understood. This study aimed to examine the relationship between irritability and symptom burden, functioning, quality of life, social support, suicidality, and overall illness severity in a naturalistic cohort of people with bipolar I or schizoaffective disorder. We used data from 239 adult outpatients with bipolar I or schizoaffective disorder in the Bipolar Comprehensive Outcomes Study (BCOS) - a non-interventional observational study with a 2-year follow-up period. Baseline demographic and clinical characteristics of participants with and without irritability were compared. A mixed-model repeated measures analysis was conducted to examine the longitudinal effect of irritability on clinical and quality-of-life variables over follow-up using significant baseline variables. At baseline, 54% of participants were irritable. Baseline irritability was associated with illness severity, mania, depression, psychotic symptoms, suicidality, poor functioning, and quality of life, but not diagnosis (schizoaffective/bipolar disorder). Participants with irritability were less likely to have a partner and perceived less adequate social support. On average, over follow-up, those with irritability reported more symptoms, functional impairment, and suicidality. Furthermore, the effects of irritability could not be fully explained by illness severity. Irritability was associated with more negative symptomatic, functional, and quality-of-life outcomes and suicidality. The identification, monitoring, and targeted treatment of irritability may be worth considering, to enhance health and wellbeing outcomes for adults with bipolar and schizoaffective disorders. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Z-Scheme NiTiO ₃ /g-C ₃ N ₄ Heterojunctions with Enhanced Photoelectrochemical and Photocatalytic Performances under Visible LED Light Irradiation

Energy Technology Data Exchange (ETDEWEB)

Huang, Zhenyu [School; Zeng, Xiaoqiao [Chemical; Li, Kai [School; Gao, Shanmin [School; Wang, Qingyao [School; Lu, Jun [Chemical

2017-11-14

Direct Z-scheme NiTiO3/g-C3N4 heterojunctions were successfully assembled by using simple calcination method and the photoelectrochemical and photocatalytic performance were investigated by light emitting diode (LED). The photoanode composed by the heterojunction with about 50 wt% NiTiO3 content exhibits the best photoelectrochemical activity with photoconversion efficiency up to 0.066%, which is 4.4 and 3.13 times larger than NiTiO3 or g-C3N4. The remarkably enhanced photoelectrochemical and photocatalytic activity of the heterojunction can be due to the efficiently photogenerated electron-hole separation by a Z-scheme mechanism.