Theory of Magnetic Bipolar Transistors

NASA Astrophysics Data System (ADS)

Zutic, Igor; Fabian, Jaroslav; Das Sarma, S.

2003-03-01

We introduce the concept of a magnetic bipolar transistor (MBT) (J. Fabian, I. Zutic, S. Das Sarma, cond-mat/0211639.), which can be realized using already available materials. The transistor has at least one magnetic region (emitter, base, or collector) characterized by spin-splitting of the carrier bands. In addition, nonequilibrium (source) spin in MBTs can be induced by external means (electrically or optically). The theory of ideal MBTs is developed and discussed in the forward active regime where the transistors can amplify signals. It is shown that source spin can be injected from the emitter to the collector. It is predicted that electrical current gain (amplification) can be controlled effectively by magnetic field and source spin. If a base is a ferromagnetic semiconductor we suggest several methods for using spin-polarized bipolar transport (I. Zutic, J. Fabian, S. Das Sarma, Phys. Rev. Lett. f 88, 066603 (2002); J. Fabian, I. Zutic, S. Das Sarma, Phys. Rev. B f 66, 165301 (2002).) to manipulate semiconductor ferromagnetism.

Gallium arsenide-gallium nitride wafer fusion and the n-aluminum gallium arsenide/p-gallium arsenide/n-gallium nitride double heterojunction bipolar transistor

NASA Astrophysics Data System (ADS)

Estrada, Sarah M.

This dissertation describes the n-AlGaAs/p-GaAs/n-GaN heterojunction bipolar transistor (HBT), the first transistor formed via wafer fusion. The fusion process was developed as a way to combine lattice-mismatched materials for high-performance electronic devices, not obtainable via conventional all-epitaxial formation methods. Despite the many challenges of wafer fusion, successful transistors were demonstrated and improved, via the optimization of material structure and fusion process conditions. Thus, this project demonstrated the integration of disparate device materials, chosen for their optimal electronic properties, unrestricted by the conventional (and very limiting) requirement of lattice-matching. By combining an AlGaAs-GaAs emitter-base with a GaN collector, the HBT benefited from the high breakdown voltage of GaN, and from the high emitter injection efficiency and low base transit time of AlGaAs-GaAs. Because the GaAs-GaN lattice mismatch precluded an all-epitaxial formation of the HBT, the GaAs-GaN heterostructure was formed via fusion. This project began with the development of a fusion process that formed mechanically robust and electrically active GaAs-GaN heterojunctions. During the correlation of device electrical performance with a systematic variation of fusion conditions over a wide range (500--750°C, 0.5--2hours), a mid-range fusion temperature was found to induce optimal HBT electrical performance. Transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS) were used to assess possible reasons for the variations observed in device electrical performance. Fusion process conditions were correlated with electrical (I-V), structural (TEM), and chemical (SIMS) analyses of the resulting heterojunctions, in order to investigate the trade-off between increased interfacial disorder (TEM) with low fusion temperature and increased diffusion (SIMS) with high fusion temperature. The best do device results (IC ˜ 2.9 kA/cm2 and beta �

Flexible Low-power SiGe HBT Amplifier Circuits for Fast Single-shot Spin Readout

NASA Astrophysics Data System (ADS)

England, Troy; Lilly, Michael; Curry, Matthew; Carr, Stephen; Carroll, Malcolm

Fast, low-power quantum state readout is one of many challenges facing quantum information processing. Single electron transistors (SETs) are potentially fast, sensitive detectors for performing spin readout of electrons bound to Si:P donors. From a circuit perspective, however, their output impedance and nonlinear conductance are ill suited to drive the parasitic capacitance of coaxial conductors used in cryogenic environments, necessitating a cryogenic amplification stage. We will introduce two new amplifier topologies that provide excellent gain versus power tradeoffs using silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs). The AC HBT allows in-situ adjustment of power dissipation during an experiment and can provide gain in the millikelvin temperature regime while dissipating less than 500 nW. The AC Current Amplifier maximizes gain at nearly 800 A/A. We will also show results of using these amplifiers with SETs at 4 K. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000. Flexible Low-power SiGe HBT Amplifier Circuits for Fast Single-shot Spin Readout.

Bipolar Spintronics: From magnetic diodes to magnetic bipolar transistors

NASA Astrophysics Data System (ADS)

Zutic, Igor

2004-03-01

We develop a theory of bipolar (electrons and holes) spin-polarized transport [1,2] in semiconductors and discuss its implications for spintronic devices [3]. In our proposal for magnetic bipolar transistors [4,5] we show how bipolar spintronics can lead to spin and magnetic field controlled active devices, not limited by the magnetoresistive effects used in all-metallic structures [3]. We focus on magnetic p-n diodes [1,2] with spatially dependent spin splitting (Zeeman or exchange) of carrier bands. An exchange splitting can be provided by ferromagnetic semiconductors [6], while a large Zeeman splitting can be realized in the presence of magnetic field in magnetically doped or narrow band gap semiconductors [3]. Our theory of magnetic diodes [1,2] can be directly applied to magnetic bipolar transistors--the three-terminal devices which consist of two magnetic p-n diodes connected in series [4,5]. Predictions of exponentially large magnetoresistance [1] and a strong coupling between the spin and charge transport leading to the spin-voltaic effect [1,7] for magnetic diodes are also relevant for magnetic bipolar transistors. In particular, in n-p-n transistors, we show the importance of considering the nonequilibrium spin leading to the spin-voltaic effect. In addition to the applied magnetic filed, the injected nonequilibrium spin can be used to dynamically control the current amplification (gain). Recent experimental progress [8,9] supports the viability of our theoretical proposals. [1] I. Zutic, J. Fabian, S. Das Sarma, Phys. Rev. Lett. 88, 066603 (2002). [2] J. Fabian, I. Zutic, S. Das Sarma, Phys. Rev. B 66, 165301 (2002). [3] I. Zutic, J. Fabian, S. Das Sarma, Rev. Mod. Phys., in press. [4] J. Fabian, I. Zutic, S. Das Sarma, cond-mat/0211639; cond-mat/0307014, Appl. Phys. Lett., in press. [5] J. Fabian and I. Zutic, cond-mat/0311456. [6] H. Ohno, Science 281, 951 (1998). [7] I. Zutic, J. Fabian, S. Das Sarma, Appl. Phys. Lett. 82, 221 (2003). [8] N. Samarth

Up-converted 1/f PM and AM noise in linear HBT amplifiers.

PubMed

Ferre-Pikal, Eva S; Savage, Frederick H

2008-08-01

In this paper we describe a technique to predict the 1/f phase modulation (PM) and 1/f amplitude modulation (AM) noise due to up-conversion of 1/f baseband current noise in microwave heterojunction bipolar transistor (HBT) amplifiers. We obtain an accurate model for the amplifier and find the expression for voltage gain in terms of DC bias, transistor parameters, and circuit components. Theoretical 1/f PM and AM noise sensitivities to 1/f baseband current noise are then found by applying the definitions of PM and AM noise to the gain expression of the amplifier. Measurements of PM and AM sensitivities at 500 MHz and 1 GHz were in good agreement with the values predicted by theory, verifying the validity of this technique. This method can be used to optimize amplifier design for low PM and AM noise. We show that the amplifier PM noise can be reduced by 9 dB by adjusting the value of the input coupling capacitor.

Burst-type noise mechanisms in bipolar transistors

NASA Astrophysics Data System (ADS)

Wu, X. L.; van der Ziel, A.; Birbas, A. N.; van Rheenen, A. D.

1989-11-01

Two types of burst noise have been observed in silicon bipolar transistors. They can be characterized by the typical frequency dependence of their current fluctuation spectra. Interestingly, observation of the noise signal in the time domain gives two distinctively different pictures of the bistable waveform. Also, amplification of the noise signal yields different sounds when fed to a speaker. One of the noise spectra is the superposition of 1/ƒ noise and a Lorentzian component (burst noise) and the other can be described mathematically as 1/ƒ noise modulated by the burst noise. The classification of those two types of burst noise and the mathematical explanation will lead to a better understanding of the bipolar transistor burst noise itself.

Ion bipolar junction transistors

PubMed Central

Tybrandt, Klas; Larsson, Karin C.; Richter-Dahlfors, Agneta; Berggren, Magnus

2010-01-01

Dynamic control of chemical microenvironments is essential for continued development in numerous fields of life sciences. Such control could be achieved with active chemical circuits for delivery of ions and biomolecules. As the basis for such circuitry, we report a solid-state ion bipolar junction transistor (IBJT) based on conducting polymers and thin films of anion- and cation-selective membranes. The IBJT is the ionic analogue to the conventional semiconductor BJT and is manufactured using standard microfabrication techniques. Transistor characteristics along with a model describing the principle of operation, in which an anionic base current amplifies a cationic collector current, are presented. By employing the IBJT as a bioelectronic circuit element for delivery of the neurotransmitter acetylcholine, its efficacy in modulating neuronal cell signaling is demonstrated. PMID:20479274

High-power microwave bipolar transistor modeling

NASA Astrophysics Data System (ADS)

Asensio, Alberto; Perez, Felix

1992-01-01

This article introduces a model for high-power microwave bipolar transistors and its associated parameter-measuring strategy, whose inclusion of thermal phenomena in the dc characterization allows a good estimate of the device's thermal resistance to be obtained. This type of model provides important capabilities for solid-state radar transmitter design.

In situ arsenic-doped polycrystalline silicon as a low thermal budget emitter contact for Si/Si1 - xGex heterojunction bipolar transistors

NASA Astrophysics Data System (ADS)

King, C. A.; Johnson, R. W.; Pinto, M. R.; Luftman, H. S.; Munanka, J.

1996-01-01

A low thermal budget emitter contact with low specific contact resistivity (ρc) with the absence of transient enhanced diffusion (TED) effects is essential to fabricate integratable high performance Si/SiGe heterojunction bipolar transistors (HBTs). We report the use of in situ As-doped polycrystalline silicon (polysilicon) from a low base pressure rapid thermal episystem for this purpose and find that it meets all the requirements. We used secondary ion mass spectrometry to find that 18 nm, heavily B-doped layers remain intact after implantation into the surface polysilicon and annealing at 800 °C for 40 s. Similar samples without the surface polylayer displayed extreme broadening of B profile. Kelvin crossbridge resistors together with 2D device simulations revealed that ρc is an extremely low value of 1.2×10-8 Ω cm2 in as-deposited material. Fabrication of simple 30×30 μm2 mesa isolated HBT devices showed IC to be more than two decades higher in devices with only an in situ As-doped polyemitter compared with devices that incorporated a surface implant into the single crystal portion of the emitter before polysilicon deposition. These results demonstrate that this doped polycrystalline silicon material is an excellent choice for emitter contacts to HBT devices.

Analysis of improved dc and ac performances of an InGaP/GaAs heterojunction bipolar transistor with a graded Al xGa 1- xAs layer at emitter/base heterojunction

NASA Astrophysics Data System (ADS)

Cheng, Shiou-Ying

2004-07-01

An InGaP/GaAs heterojunction bipolar transistor (HBT) with a continuous conduction-band structure is demonstrated and theoretically investigated. This device exhibited good performance including lower turn-on voltage, lower offset voltage and smaller collector current saturation voltage. The novel aspect of device structure design is the adoption of the compositionally linear-graded AlGaAs layer between the InGaP-emitter and GaAs-base layers. Therefore, the device studied shows better dc and ac performances than a conventional device. Consequently, this causes the substantial benefit for practical analog and digital applications especially for lower operation voltage, lower power consumption commercial and military products.

Npn double heterostructure bipolar transistor with ingaasn base region

DOEpatents

Chang, Ping-Chih; Baca, Albert G.; Li, Nein-Yi; Hou, Hong Q.; Ashby, Carol I. H.

2004-07-20

An NPN double heterostructure bipolar transistor (DHBT) is disclosed with a base region comprising a layer of p-type-doped indium gallium arsenide nitride (InGaAsN) sandwiched between n-type-doped collector and emitter regions. The use of InGaAsN for the base region lowers the transistor turn-on voltage, V.sub.on, thereby reducing power dissipation within the device. The NPN transistor, which has applications for forming low-power electronic circuitry, is formed on a gallium arsenide (GaAs) substrate and can be fabricated at commercial GaAs foundries. Methods for fabricating the NPN transistor are also disclosed.

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

NASA Technical Reports Server (NTRS)

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

Development of a Planar Heterojunction Bipolar Transistor for Very High Speed Logic.

DTIC Science & Technology

1983-12-01

AD- R136 341 DEVELOPMENT OF A PLANAR HETEROJUNCTION BIPOLAR i/i TRANSISTOR FOR VERV HIGH S..(U) CALIFORNIA UNIV SANTA BARBARA DEPT OF ELECTRICAL AND...GaAs material systems . Emphasis has been placed on growth and char- acterization of the above heterojunctions by Holecular Beam Epitaxy and on the...GaAs material system is used to fabricate discrete single heterojunction bipolar transistor structures. Conventional mesa-etch tech- niques will be used

Modeling of charge transport in ion bipolar junction transistors.

PubMed

Volkov, Anton V; Tybrandt, Klas; Berggren, Magnus; Zozoulenko, Igor V

2014-06-17

Spatiotemporal control of the complex chemical microenvironment is of great importance to many fields within life science. One way to facilitate such control is to construct delivery circuits, comprising arrays of dispensing outlets, for ions and charged biomolecules based on ionic transistors. This allows for addressability of ionic signals, which opens up for spatiotemporally controlled delivery in a highly complex manner. One class of ionic transistors, the ion bipolar junction transistors (IBJTs), is especially attractive for these applications because these transistors are functional at physiological conditions and have been employed to modulate the delivery of neurotransmitters to regulate signaling in neuronal cells. Further, the first integrated complementary ionic circuits were recently developed on the basis of these ionic transistors. However, a detailed understanding of the device physics of these transistors is still lacking and hampers further development of components and circuits. Here, we report on the modeling of IBJTs using Poisson's and Nernst-Planck equations and the finite element method. A two-dimensional model of the device is employed that successfully reproduces the main characteristics of the measurement data. On the basis of the detailed concentration and potential profiles provided by the model, the different modes of operation of the transistor are analyzed as well as the transitions between the different modes. The model correctly predicts the measured threshold voltage, which is explained in terms of membrane potentials. All in all, the results provide the basis for a detailed understanding of IBJT operation. This new knowledge is employed to discuss potential improvements of ion bipolar junction transistors in terms of miniaturization and device parameters.

A gallium phosphide high-temperature bipolar junction transistor

NASA Technical Reports Server (NTRS)

Zipperian, T. E.; Dawson, L. R.; Chaffin, R. J.

1981-01-01

Preliminary results are reported on the development of a high temperature (350 C) gallium phosphide bipolar junction transistor (BJT) for geothermal and other energy applications. This four-layer p(+)n(-)pp(+) structure was formed by liquid phase epitaxy using a supercooling technique to insure uniform nucleation of the thin layers. Magnesium was used as the p-type dopant to avoid excessive out-diffusion into the lightly doped base. By appropriate choice of electrodes, the device may also be driven as an n-channel junction field-effect transistor. The initial design suffers from a series resistance problem which limits the transistor's usefulness at high temperatures.

Electrical coupling of single cardiac rat myocytes to field-effect and bipolar transistors.

PubMed

Kind, Thomas; Issing, Matthias; Arnold, Rüdiger; Müller, Bernt

2002-12-01

A novel bipolar transistor for extracellular recording the electrical activity of biological cells is presented, and the electrical behavior compared with the field-effect transistor (FET). Electrical coupling is examined between single cells separated from the heart of adults rats (cardiac myocytes) and both types of transistors. To initiate a local extracellular voltage, the cells are periodically stimulated by a patch pipette in voltage clamp and current clamp mode. The local extracellular voltage is measured by the planar integrated electronic sensors: the bipolar and the FET. The small signal transistor currents correspond to the local extracellular voltage. The two types of sensor transistors used here were developed and manufactured in the laboratory of our institute. The manufacturing process and the interfaces between myocytes and transistors are described. The recordings are interpreted by way of simulation based on the point-contact model and the single cardiac myocyte model.

Degradation Mechanisms for GaN and GaAs High Speed Transistors

PubMed Central

Cheney, David J.; Douglas, Erica A.; Liu, Lu; Lo, Chien-Fong; Gila, Brent P.; Ren, Fan; Pearton, Stephen J.

2012-01-01

We present a review of reliability issues in AlGaN/GaN and AlGaAs/GaAs high electron mobility transistors (HEMTs) as well as Heterojunction Bipolar Transistors (HBTs) in the AlGaAs/GaAs materials systems. Because of the complex nature and multi-faceted operation modes of these devices, reliability studies must go beyond the typical Arrhenius accelerated life tests. We review the electric field driven degradation in devices with different gate metallization, device dimensions, electric field mitigation techniques (such as source field plate), and the effect of device fabrication processes for both DC and RF stress conditions. We summarize the degradation mechanisms that limit the lifetime of these devices. A variety of contact and surface degradation mechanisms have been reported, but differ in the two device technologies: For HEMTs, the layers are thin and relatively lightly doped compared to HBT structures and there is a metal Schottky gate that is directly on the semiconductor. By contrast, the HBT relies on pn junctions for current modulation and has only Ohmic contacts. This leads to different degradation mechanisms for the two types of devices.

Review of Heterojunctin Bipolar Transistor Structure, Applications, and Reliability

NASA Technical Reports Server (NTRS)

Lee, C.; Kayali, S.

1993-01-01

Heterojunction Bipolar Transistors (HBTs) are increasingly employed in high frequency, high linerity, and high efficiency applications. As the utilization of these devices becomes more widespread, their operation will be viewed with more scrutiny.

Total Dose Effects in Conventional Bipolar Transistors

NASA Technical Reports Server (NTRS)

Johnston, A. H.; Swift, G. W.; Rax, B. G.

1994-01-01

This paper examines various factors in bipolar device construction and design, and discusses their impact on radiation hardness. The intent of the paper is to improve understanding of the underlying mechanisms for practical devices without special test structures, and to provide (1) guidance in ways to select transistor designs that are more resistant to radiation damage, and (2) methods to estimate the maximum amount of damage that might be expected from a basic transistor design. The latter factor is extremely important in assessing the risk that future lots of devices will be substantially below design limits, which are usually based on test data for older devices.

Carrier tunneling in models of irradiated heterojunction bipolar transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wampler, William R.; Myers, Samuel Maxwell

2014-08-01

As part of Sandia's program to simulate the effect of displacement damage on operation of heterojunction bipolar transistors (HBTs), we are examining the formulation in 1-D of band-to-band (bb) and band-to-trap (b-t) carrier tunneling.

Atomic-Monolayer Two-Dimensional Lateral Quasi-Heterojunction Bipolar Transistors with Resonant Tunneling Phenomenon.

PubMed

Lin, Che-Yu; Zhu, Xiaodan; Tsai, Shin-Hung; Tsai, Shiao-Po; Lei, Sidong; Shi, Yumeng; Li, Lain-Jong; Huang, Shyh-Jer; Wu, Wen-Fa; Yeh, Wen-Kuan; Su, Yan-Kuin; Wang, Kang L; Lan, Yann-Wen

2017-11-28

High-frequency operation with ultrathin, lightweight, and extremely flexible semiconducting electronics is highly desirable for the development of mobile devices, wearable electronic systems, and defense technologies. In this work, the experimental observation of quasi-heterojunction bipolar transistors utilizing a monolayer of the lateral WSe 2 -MoS 2 junctions as the conducting p-n channel is demonstrated. Both lateral n-p-n and p-n-p heterojunction bipolar transistors are fabricated to exhibit the output characteristics and current gain. A maximum common-emitter current gain of around 3 is obtained in our prototype two-dimensional quasi-heterojunction bipolar transistors. Interestingly, we also observe the negative differential resistance in the electrical characteristics. A potential mechanism is that the negative differential resistance is induced by resonant tunneling phenomenon due to the formation of quantum well under applying high bias voltages. Our results open the door to two-dimensional materials for high-frequency, high-speed, high-density, and flexible electronics.

Local bipolar-transistor gain measurement for VLSI devices

NASA Astrophysics Data System (ADS)

Bonnaud, O.; Chante, J. P.

1981-08-01

A method is proposed for measuring the gain of a bipolar transistor region as small as possible. The measurement then allows the evaluation particularly of the effect of the emitter-base junction edge and the technology-process influence of VLSI-technology devices. The technique consists in the generation of charge carriers in the transistor base layer by a focused laser beam in order to bias the device in as small a region as possible. To reduce the size of the conducting area, a transversal reverse base current is forced through the base layer resistance in order to pinch in the emitter current in the illuminated region. Transistor gain is deduced from small signal measurements. A model associated with this technique is developed, and this is in agreement with the first experimental results.

Bipolar Transistors Can Detect Charge in Electrostatic Experiments

ERIC Educational Resources Information Center

Dvorak, L.

2012-01-01

A simple charge indicator with bipolar transistors is described that can be used in various electrostatic experiments. Its behaviour enables us to elucidate links between 'static electricity' and electric currents. In addition it allows us to relate the sign of static charges to the sign of the terminals of an ordinary battery. (Contains 7 figures…

Experiments with Charge Indicator Based on Bipolar Transistors

ERIC Educational Resources Information Center

Dvorak, Leos; Planinsic, Gorazd

2012-01-01

A simple charge indicator with bipolar transistors described recently enables us to perform a number of experiments suitable for high-school physics. Several such experiments are presented and discussed in this paper as well as some features of the indicator important for its use in schools, namely its sensitivity and robustness, i.e. the…

Experimental Analysis of Proton-Induced Displacement and Ionization Damage Using Gate-Controlled Lateral PNP Bipolar Transistors

NASA Technical Reports Server (NTRS)

Ball, D. R.; Schrimpf, R. D.; Barnaby, H. J.

2006-01-01

The electrical characteristics of proton-irradiated bipolar transistors are affected by ionization damage to the insulating oxide and displacement damage to the semiconductor bulk. While both types of damage degrade the transistor, it is important to understand the mechanisms individually and to be able to analyze them separately. In this paper, a method for analyzing the effects of ionization and displacement damage using gate-controlled lateral PNP bipolar junction transistors is described. This technique allows the effects of oxide charge, surface recombination velocity, and bulk traps to be measured independently.

Low-frequency noise behavior of polysilicon emitter bipolar junction transistors: a review

NASA Astrophysics Data System (ADS)

Deen, M. Jamal; Pascal, Fabien

2003-05-01

For many analog integrated circuit applications, the polysilicon emitter bipolar junction transistor (PE-BJT) is still the preferred choice because of its higher operational frequency and lower noise performance characteristics compared to MOS transistors of similar active areas and at similar biasing currents. In this paper, we begin by motivating the reader with reasons why bipolar transistors are still of great interest for analog integrated circuits. This motivation includes a comparison between BJT and the MOSFET using a simple small-signal equivalent circuit to derive important parameters that can be used to compare these two technologies. An extensive review of the popular theories used to explain low frequency noise results is presented. However, in almost all instances, these theories have not been fully tested. The effects of different processing technologies and conditions on the noise performance of PE-BJTs is reviewed and a summary of some of the key technological steps and device parameters and their effects on noise is discussed. The effects of temperature and emitter geometries scaling is reviewed. It is shown that dispersion of the low frequency noise in ultra-small geometries is a serious issue since the rate of increase of the noise dispersion is faster than the noise itself as the emitter geometry is scaled to smaller values. Finally, some ideas for future research on PE-BJTs, some of which are also applicable to SiGe heteorjunction bipolar transistors and MOSFETs, are presented after the conclusions.

Copper-Based OHMIC Contracts for the Si/SiGe Heterojunction Bipolar Transistor Structure

NASA Technical Reports Server (NTRS)

Das, Kalyan; Hall, Harvey

1999-01-01

Silicon based heterojunction bipolar transistors (HBT) with SiGe base are potentially important devices for high-speed and high-frequency microelectronics. These devices are particularly attractive as they can be fabricated using standard Si processing technology. However, in order to realize the full potential of devices fabricated in this material system, it is essential to be able to form low resistance ohmic contacts using low thermal budget process steps and have full compatibility with VLSI/ULSI processing. Therefore, a study was conducted in order to better understand the contact formation and to develop optimized low resistance contacts to layers with doping densities corresponding to the p-type SiGe base and n-type Si emitter regions of the HBTS. These as-grown doped layers were implanted with BF(sub 2) up to 1 X 10(exp 16)/CM(exp 2) and As up to 5 x 10(exp 15)/CM2, both at 30 keV for the p-type SiGe base and n-type Si emitter layers, respectively, in order to produce a low sheet resistance surface layer. Standard transfer length method (TLM) contact pads on both p and n type layers were deposited using an e-beam evaporated trilayer structure of Ti/CufTi/Al (25)A/1500A/250A/1000A). The TLM pads were delineated by a photoresist lift-off procedure. These contacts in the as-deposited state were ohmic, with specific contact resistances for the highest implant doses of the order of 10(exp -7) ohm-CM2 and lower.

Negative differential transconductance in silicon quantum well metal-oxide-semiconductor field effect/bipolar hybrid transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naquin, Clint; Lee, Mark; Edwards, Hal

2014-11-24

Introducing explicit quantum transport into Si transistors in a manner amenable to industrial fabrication has proven challenging. Hybrid field-effect/bipolar Si transistors fabricated on an industrial 45 nm process line are shown to demonstrate explicit quantum transport signatures. These transistors incorporate a lateral ion implantation-defined quantum well (QW) whose potential depth is controlled by a gate voltage (V{sub G}). Quantum transport in the form of negative differential transconductance (NDTC) is observed to temperatures >200 K. The NDTC is tied to a non-monotonic dependence of bipolar current gain on V{sub G} that reduces drain-source current through the QW. These devices establish the feasibility ofmore » exploiting quantum transport to transform the performance horizons of Si devices fabricated in an industrially scalable manner.« less

The total switch time of silicon bipolar transistors with base doping gradients or with germanium gradients in the base

NASA Astrophysics Data System (ADS)

Karlsteen, M.; Willander, M.

1993-11-01

In this paper the total switch time for a transistor in a Direct Coupled Transistor Logic (DCTL) circuit is simulated by using Laplace transformations of the Ebers-Moll equations. The influence of doping gradients and germanium gradients in the base is investigated and their relative importance and their limitations are established. In a well designed bipolar transistor only a minor enhancement of the total switch time is obtained with the use of a doping gradient in the base. However, for bipolar transistors with base thickness over 500 Å, an improperly selected doping profile could be devastating for the total switch time. For a bipolar transistor the improvement of the total switch time due to a linear germanium gradient in the base could be up to about 30% compared with an ordinary silicon bipolar transistor. Still, a too high germanium gradient forces the normal transistor current gain (α N) to grow and the total switch time is thereby increased. Further enhancement could be achieved by the use of a second degree polynomial germanium profile in the base. Also in this case, care must be taken not to enlarge the germanium gradient too much as the total switch time then starts to increase. In all cases the betterment of the base transit time that is introduced by the electric field will not be directly used to reduce the base transit time. Instead the improvement is mostly used to lower the emitter transition charging time. However, the most important parameter to control is the normal transistor current gain (α N) that has to be kept within a narrow range to keep the total switch time low.

High-frequency output characteristics of AlGaAs/GaAs heterojunction bipolar transistors for large-signal applications

NASA Astrophysics Data System (ADS)

Chen, J.; Gao, G. B.; Ünlü, M. S.; Morkoç, H.

1991-11-01

High-frequency ic- vce output characteristics of bipolar transistors, derived from calculated device cutoff frequencies, are reported. The generation of high-frequency output characteristics from device design specifications represents a novel bridge between microwave circuit design and device design: the microwave performance of simulated device structures can be analyzed, or tailored transistor device structures can be designed to fit specific circuit applications. The details of our compact transistor model are presented, highlighting the high-current base-widening (Kirk) effect. The derivation of the output characteristics from the modeled cutoff frequencies are then presented, and the computed characteristics of an AlGaAs/GaAs heterojunction bipolar transistor operating at 10 GHz are analyzed. Applying the derived output characteristics to microwave circuit design, we examine large-signal class A and class B amplification.

Perpendicular transport in superlattice bipolar transistors (SBT)

NASA Astrophysics Data System (ADS)

Sibille, A.; Palmier, J. F.; Minot, C.; Harmand, J. C.; Dubon-Chevallier, C.

Diffusion-limited electron transport in superlattices is studied by gain measurements on heterojunction bipolar transistors with a {GaAs}/{GaAlAs} superlattice base. In the case of thin barriers, Bloch conduction is observed, while hopping between localized levels prevails for large barriers. A transition occurs between these two regimes, localization being achieved when the energy broadening induced by the electron-phonon coupling added to the disorder due to imperfect growth is of the order of the miniband width. This interpretation is supported by temperature dependence measurements of the perpendicular mobilities in relation with theoretical calculations of these mobilities.

Dose Rate Effects in Linear Bipolar Transistors

NASA Technical Reports Server (NTRS)

Johnston, Allan; Swimm, Randall; Harris, R. D.; Thorbourn, Dennis

2011-01-01

Dose rate effects are examined in linear bipolar transistors at high and low dose rates. At high dose rates, approximately 50% of the damage anneals at room temperature, even though these devices exhibit enhanced damage at low dose rate. The unexpected recovery of a significant fraction of the damage after tests at high dose rate requires changes in existing test standards. Tests at low temperature with a one-second radiation pulse width show that damage continues to increase for more than 3000 seconds afterward, consistent with predictions of the CTRW model for oxides with a thickness of 700 nm.

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

NASA Astrophysics Data System (ADS)

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.

Using Animation to Improve the Students' Academic Achievement on Bipolar Junction Transistor

ERIC Educational Resources Information Center

Zoabi, W.; Sabag, N.; Gero, A.

2012-01-01

Teaching abstract subjects to students studying towards a degree in electronics practical engineering (a degree between a technician and an engineer) requires didactic tools that enable understanding of issues without using advanced mathematics and physics. One basic issue is the BJT (Bipolar Junction Transistor) that requires preliminary…

Fabrication and high temperature characteristics of ion-implanted GaAs bipolar transistors and ring-oscillators

NASA Technical Reports Server (NTRS)

Doerbeck, F. H.; Yuan, H. T.; Mclevige, W. V.

1981-01-01

Ion implantation techniques that permit the reproducible fabrication of bipolar GaAs integrated circuits are studied. A 15 stage ring oscillator and discrete transistor were characterized between 25 and 400 C. The current gain of the transistor was found to increase slightly with temperature. The diode leakage currents increase with an activation energy of approximately 1 eV and dominate the transistor leakage current 1 sub CEO above 200 C. Present devices fail catastrophically at about 400 C because of Au-metallization.

Unified planar process for fabricating heterojunction bipolar transistors and buried-heterostructure lasers utilizing impurity-induced disordering

NASA Astrophysics Data System (ADS)

Thornton, R. L.; Mosby, W. J.; Chung, H. F.

1988-12-01

We describe results on a novel geometry of heterojunction bipolar transistor that has been realized by impurity-induced disordering. This structure is fabricated by a method that is compatible with techniques for the fabrication of low threshold current buried-heterostructure lasers. We have demonstrated this compatibility by fabricating a hybrid laser/transistor structure that operates as a laser with a threshold current of 6 mA at room temperature, and as a transistor with a current gain of 5.

Base and collector resistances in heterojunction bipolar transistors

NASA Astrophysics Data System (ADS)

Anholt, R.; Bozada, C.; Desalvo, G.; Dettmer, R.; Ebel, J.; Gillespie, J.; Jenkins, T.; Havasy, C.; Ito, C.; Nakano, K.; Pettiford, C.; Quach, T.; Sewell, J.; Via, D.

1997-11-01

In heterojunction bipolar transistors (HBTs), the reverse base currents flow from the outer base periphery to the collector. The reverse base and collector resistances are therefore dominated by contact resistance, which is inversely proportional to the outer base and inner collector periphery lengths which are larger than the emitter lengths when the base and collector electrodes surround the emitter element. These resistances can be extracted from reverse Gummel (current vs Vbc with Vbc = 0) and from measurements of output resistances at zero collector voltage sweeps. We compare models with measurements where the base and collector peripheries decrease with increasing emitter diameters.

Quantum-well-base heterojunction bipolar light-emitting transistor

NASA Astrophysics Data System (ADS)

Feng, M.; Holonyak, N.; Chan, R.

2004-03-01

This letter reports the enhanced radiative recombination realized by incorporating InGaAs quantum wells in the base layer of light-emitting InGaP/GaAs heterojunction bipolar transistors (LETs) operating in the common-emitter configuration. Two 50 Å In1-xGaxAs (x=85%) quantum wells (QWs) acting, in effect, as electron capture centers ("traps") are imbedded in the 300 Å GaAs base layer, thus improving (as a "collector" and recombination center) the light emission intensity compared to a similar LET structure without QWs in the base. Gigahertz operation of the QW LET with simultaneously amplified electrical output and an optical output with signal modulation is demonstrated.

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

NASA Astrophysics Data System (ADS)

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

One bipolar transistor selector - One resistive random access memory device for cross bar memory array

NASA Astrophysics Data System (ADS)

Aluguri, R.; Kumar, D.; Simanjuntak, F. M.; Tseng, T.-Y.

2017-09-01

A bipolar transistor selector was connected in series with a resistive switching memory device to study its memory characteristics for its application in cross bar array memory. The metal oxide based p-n-p bipolar transistor selector indicated good selectivity of about 104 with high retention and long endurance showing its usefulness in cross bar RRAM devices. Zener tunneling is found to be the main conduction phenomena for obtaining high selectivity. 1BT-1R device demonstrated good memory characteristics with non-linearity of 2 orders, selectivity of about 2 orders and long retention characteristics of more than 105 sec. One bit-line pull-up scheme shows that a 650 kb cross bar array made with this 1BT1R devices works well with more than 10 % read margin proving its ability in future memory technology application.

Effect of germanium concentrations on tunnelling current calculation of Si/Si1-xGex/Si heterojunction bipolar transistor

NASA Astrophysics Data System (ADS)

Hasanah, L.; Suhendi, E.; Khairrurijal

2018-05-01

Tunelling current calculation on Si/Si1-xGex/Si heterojunction bipolar transistor was carried out by including the coupling between transversal and longitudinal components of electron motion. The calculation results indicated that the coupling between kinetic energy in parallel and perpendicular to S1-xGex barrier surface affected tunneling current significantly when electron velocity was faster than 1x105 m/s. This analytical tunneling current model was then used to study how the germanium concentration in base to Si/Si1-xGex/Si heterojunction bipolar transistor influenced the tunneling current. It is obtained that tunneling current increased as the germanium concentration given in base decreased.

Modelling the influence of high currents on the cutoff frequency in Si/SiGe/Si heterojunction transistors

NASA Astrophysics Data System (ADS)

Briggs, P. J.; Walker, A. B.; Herbert, D. C.

1998-05-01

A one-dimensional self-consistent bipolar Monte Carlo simulation code has been used to model carrier mobilities in strained doped SiGe and the base-collector region of Si/SiGe/Si and SiC/Si heterojunction bipolar transistors (HBTs) with wide collectors, to study the variation of the cutoff frequency 0268-1242/13/5/005/img6 with collector current density 0268-1242/13/5/005/img7. Our results show that while the presence of strain enhances the electron mobility, the scattering from alloy disorder and from ionized impurities reduces the electron mobility so much that it is less than that of Si at the same doping level, leading to larger base transit times 0268-1242/13/5/005/img8 and hence poorer 0268-1242/13/5/005/img6 performance for large 0268-1242/13/5/005/img7 for an Si/SiGe/Si HBT than for an SiC/Si HBT. At high values of 0268-1242/13/5/005/img7, we demonstrate the formation of a parasitic electron barrier at the base-collector interface which causes a sharp increase in 0268-1242/13/5/005/img8 and hence a dramatic reduction in 0268-1242/13/5/005/img6. Based on a comparison of the height of this parasitic barrier with estimates from an analytical model, we suggest a physical mechanism for base pushout after barrier formation that differs somewhat from that given for the analytical model.

Surface passivation of InGaP/GaAs HBT using silicon-nitride film deposited by ECR CVD plasma

NASA Astrophysics Data System (ADS)

Manera, L. T.; Zoccal, L. B.; Diniz, J. A.; Tatsch, P. J.; Doi, I.

2008-07-01

In this paper we have developed a passivation technique with silicon-nitride (SiN X) film that requires no surface pre-treatment, and is fully compatible to monolithic microwave integrated circuits (MMICs). The nitride depositions were carried out by ECR-CVD (electron cyclotron resonance-chemical vapor deposition) directly over InGaP/GaAs heterojunction structures, which are used for heterojunction bipolar transistors (HBTs). Optical emission spectrometry (OES) was used for plasma characterization, and low formation of H and NH molecules in the gas phase was detected at pressure of 2.5 mTorr. These molecules can degrade III-V semiconductor surfaces due to the preferential loss of As or P and hydrogen incorporation at the substrate. The substrates were cleaned with organic solvents using a Sox-let distillate. The ECR depositions were carried out at a fixed substrate temperature of 20 °C, SiH 4/N 2 flow ratio of 1, Ar flow of 5 sccm pressure of 2.5 mTorr and microwave (2.45 GHz) power of 250 W and RF (13.56 MHz) power of 4 W. We have applied this film for InGaP/GaAs HBT fabrication process with excellent results, where two major contribuiton is related to this passivation technique, the enhancement in the transistor dc gain β and the improvement in the signal-to-noise ratio when compared unpassivated and passivated devices.

Demonstration and properties of a planar heterojunction bipolar transistor with lateral current flow

NASA Astrophysics Data System (ADS)

Thornton, Robert L.; Mosby, William J.; Chung, Harlan F.

1989-10-01

The authors present fabrication techniques and device performance for a novel transistor structure, the lateral heterojunction bipolar transistor. The lateral heterojunctions are formed by impurity-induced disordering of a GaAs base layer sandwiched between two AlGaAs layers. These transistor structures exhibit current gains of 14 for base widths of 0.74 micron. Transistor action in this device occurs parallel to the surface of the device structure. The active base region of the structure is completely submerged, resulting in a reduction of surface recombination as a mechanism for gain reduction in the device. Impurity-induced disordering is used to widen the bandgap of the alloy in the emitter and collector, resulting in an improvement of the emitter injection efficiency. Since the device is based entirely on a surface diffusion process, the device is completely planar and has no steps involving etching of the III-V alloy material. These advantages lead this device to be considered as a candidate for optoelectronic integration applications. The transistor device functions as a buried heterostructure laser, with a threshold current as low as 6 mA for a 1.4-micron stripe.

An analog front-end bipolar-transistor integrated circuit for the SDC silicon tracker

NASA Astrophysics Data System (ADS)

Kipnis, I.; Spieler, H.; Collins, T.

1994-08-01

A low-noise, low-power, high-bandwidth, radiation hard, silicon bipolar-transistor full-custom integrated circuit (IC) containing 64 channels of analog signal processing has been developed for the SDC silicon tracker The IC was designed and tested at LBL and was fabricated using AT&T's CBIC-U2, 4 GHz f/sub /spl tau// complementary bipolar technology. Each channel contains the following functions: low-noise preamplification, pulse shaping and threshold discrimination. This is the first iteration of the production analog IC for the SDC silicon tracker. The IC is laid out to directly match the 50 /spl mu/m pitch double-sided silicon strip detector. The chip measures 6.8 mm/spl times/3.1 mm and contains 3,600 transistors. Three stages of amplification provide 180 mV/fC of gain with a 35 nsec peaking time at the comparator input. For a 14 pF detector capacitance, the equivalent noise charge is 1300 el. RMS at a power consumption of 1 mW/channel from a single 3.5 V supply. With the discriminator threshold set to 4 times the noise level, a 16 nsec time-walk for 1.25 to 10 fC signals is achieved using a time-walk compensation network. Irradiation tests at TRIUMF to a /spl Phi/=10/sup 14/ protons/cm/sup 2/ have been performed on the IC, demonstrating the radiation hardness of the complementary bipolar process.

Transient electro-thermal characterization of Si-Ge heterojunction bipolar transistors

NASA Astrophysics Data System (ADS)

Sahoo, Amit Kumar; Weiß, Mario; Fregonese, Sébastien; Malbert, Nathalie; Zimmer, Thomas

2012-08-01

In this paper, a comprehensive evaluation of the transient self-heating in microwave heterojunction bipolar transistors (HBTs) have been carried out through simulations and measurements. Three dimensional thermal TCAD simulations have been performed to investigate precisely the influence of backend metallization on transient thermal behavior of a submicron SiGe:C BiCMOS technology with fT and fmax of 230 GHz and 290 GHz, respectively. Transient variation of Collector current caused by self-heating is obtained through pulse measurements. For thermal characterization, different electro-thermal networks have been employed at the temperature node of HiCuM compact model. Thermal parameters have been extracted by means of compact model simulation using a scalable transistor library. It has been shown that, the conventional R-C thermal network is not sufficient to accurately model the transient thermal spreading behavior and therefore a recursive network needs to be used. Recursive network is verified with device simulations as well as measurements and found to be in excellent agreement.

Thermal management of microwave power heterojunction bipolar transistors

NASA Astrophysics Data System (ADS)

Bozada, C.; Cerny, C.; De Salvo, G.; Dettmer, R.; Ebel, J.; Gillespie, J.; Havasy, C.; Jenkins, T.; Ito, C.; Nakano, K.; Pettiford, C.; Quach, T.; Sewell, J.; Via, G. D.; Anholt, R.

1997-10-01

A comprehensive study of the device layout effects on thermal resistance in thermally-shunted heterojunction bipolar transistors (HBTs) was completed. The thermal resistance scales linearly with emitter dot diameter for single element HBTs. For multiple emitter element devices, the thermal resistance scales with area. HBTs with dot geometrics have lower thermal impedance than bar HBTs with equivalent emitter area. The thermal resistance of a 200 μm 2 emitter area device was reduced from 266°C/W to 146°C/W by increasing the shunt thickness from 3 μm to 20 μm and placing a thermal shunt landing between the fingers. Also, power-added efficiencies at 10 GHz were improved from 30% to 68% by this thermal resistance reduction.

Comparison between Field Effect Transistors and Bipolar Junction Transistors as Transducers in Electrochemical Sensors

NASA Astrophysics Data System (ADS)

Zafar, Sufi; Lu, Minhua; Jagtiani, Ashish

2017-01-01

Field effect transistors (FET) have been widely used as transducers in electrochemical sensors for over 40 years. In this report, a FET transducer is compared with the recently proposed bipolar junction transistor (BJT) transducer. Measurements are performed on two chloride electrochemical sensors that are identical in all details except for the transducer device type. Comparative measurements show that the transducer choice significantly impacts the electrochemical sensor characteristics. Signal to noise ratio is 20 to 2 times greater for the BJT sensor. Sensitivity is also enhanced: BJT sensing signal changes by 10 times per pCl, whereas the FET signal changes by 8 or less times. Also, sensor calibration curves are impacted by the transducer choice. Unlike a FET sensor, the calibration curve of the BJT sensor is independent of applied voltages. Hence, a BJT sensor can make quantitative sensing measurements with minimal calibration requirements, an important characteristic for mobile sensing applications. As a demonstration for mobile applications, these BJT sensors are further investigated by measuring chloride levels in artificial human sweat for potential cystic fibrosis diagnostic use. In summary, the BJT device is demonstrated to be a superior transducer in comparison to a FET in an electrochemical sensor.

S-MMICs: Sub-mm-Wave Transistors and Integrated Circuits

DTIC Science & Technology

2008-09-01

Research Lab BAA DAAD19-03-R-0017 Research area 2.35: RF devices—Dr. Alfred Hung Submitted by: Mark Rodwell, Department of Electrical and Computer ...MOTIVATION / APPLICATION 3 TECHNOLOGY STATUS 4 TRANSISTOR SCALING LAWS 5 256 NM GENERATION 6 HBT POWER AMPLIFIER DEVELOPMENT 7 DRY-ETCHED EMITTER...TECHNOLOGY: 256 NM GENERATION 9 SCALED EPITAXY 11 CONCLUSIONS 12 20081103013 Executive Summary Transistor and power amplifier IC technology was

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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.

Note: cryogenic low-noise dc-coupled wideband differential amplifier based on SiGe heterojunction bipolar transistors.

PubMed

Beev, Nikolai; Kiviranta, Mikko

2012-06-01

Silicon-germanium heterojunction bipolar transistors can be used to construct low-noise cryogenic amplifiers. We present a dc-coupled differential amplifier capable of operating down to 10 K. In this temperature regime it has bandwidth of 15 MHz and noise temperature as low as 1.3 K. When operated at liquid nitrogen temperature of 77 K, the measured noise temperature is lower than 3 K. The amplifier is based on the commercially available transistors NESG3031 and operational amplifier OPA836 and is capable of standalone operation without any additional stages at room temperature.

Design considerations for FET-gated power transistors

NASA Technical Reports Server (NTRS)

Chen, D. Y.; Chin, S. A.

1983-01-01

An FET-bipolar combinational power transistor configuration (tested up to 300 V, 20 A at 100 kHz) is described. The critical parameters for integrating the chips in hybrid form are examined, and an effort to optimize the overall characteristics of the configuration is discussed. Chip considerations are examined with respect to the voltage and current rating of individual chips, the FET surge capability, the choice of triple diffused transistor or epitaxial transistor for the bipolar element, the current tailing effect, and the implementation of the bipolar transistor and an FET as single chip or separate chips. Package considerations are discussed with respect to package material and geometry, surge current capability of bipolar base terminal bonding, and power losses distribution.

A 311-GHz Fundamental Oscillator Using InP HBT Technology

NASA Technical Reports Server (NTRS)

Gaier, Todd; Fung, King Man; Samoska, Lorene; Radisic, Vesna; Sawdai, Donald; Scott, Dennis; Deal, W.R.

2010-01-01

This oscillator uses a single-emitter 0.3- m InP heterojunction bipolar transistor (HBT) device with maximum frequency of oscillation (fmax) greater than 500 GHz. Due to high conductor and substrate losses at submillimeterwave frequencies, a primary challenge is to efficiently use the intrinsic device gain. This was done by using a suitable transmission-line media and circuit topology. The passive components of the oscillator are realized in a twometal process with benzocyclobutene (BCB) used as the primary transmission line dielectric. The circuit was designed using microstrip transmission lines. The oscillator is implemented in a common-base topology due to its inherent instability, and the design includes an on-chip resonator, outputmatching circuitry, and an injection-locking port, the port being used to demonstrate the injection-locking prin ciple. A free-running frequency of 311.6 GHz has been measured by down-converting the signal. Ad di tionally, injection locking has been successfully demonstrated with up to 17.8 dB of injection-locking gain. The injection-locking reference signal is generated using a 2 20 GHz frequency synthesizer, followed by a doubler, active tripler, a W-band amplifier, and then a passive tripler. Therefore, the source frequency is multiplied 18 times to obtain a signal above 300 GHz that can be used to injection lock the oscillator. Measurement shows that injection locking has improved the phase noise of the oscillator and can be also used for synchronizing a series of oscillators. A signal conductor is implemented near the BCP -InP interface and the topside of the BCB layer is fully metallized as a signal ground. Because the fields are primarily constrained in the lower permittivity BCB region, this type of transmission line is referred to as an inverted microstrip. In addition, both common-emitter and commonbase circuits were investigated to determine optimum topology for oscillator design. The common -base topology required smaller

Comparison between Field Effect Transistors and Bipolar Junction Transistors as Transducers in Electrochemical Sensors

PubMed Central

Zafar, Sufi; Lu, Minhua; Jagtiani, Ashish

2017-01-01

Field effect transistors (FET) have been widely used as transducers in electrochemical sensors for over 40 years. In this report, a FET transducer is compared with the recently proposed bipolar junction transistor (BJT) transducer. Measurements are performed on two chloride electrochemical sensors that are identical in all details except for the transducer device type. Comparative measurements show that the transducer choice significantly impacts the electrochemical sensor characteristics. Signal to noise ratio is 20 to 2 times greater for the BJT sensor. Sensitivity is also enhanced: BJT sensing signal changes by 10 times per pCl, whereas the FET signal changes by 8 or less times. Also, sensor calibration curves are impacted by the transducer choice. Unlike a FET sensor, the calibration curve of the BJT sensor is independent of applied voltages. Hence, a BJT sensor can make quantitative sensing measurements with minimal calibration requirements, an important characteristic for mobile sensing applications. As a demonstration for mobile applications, these BJT sensors are further investigated by measuring chloride levels in artificial human sweat for potential cystic fibrosis diagnostic use. In summary, the BJT device is demonstrated to be a superior transducer in comparison to a FET in an electrochemical sensor. PMID:28134275

Advanced insulated gate bipolar transistor gate drive

DOEpatents

Short, James Evans [Monongahela, PA; West, Shawn Michael [West Mifflin, PA; Fabean, Robert J [Donora, PA

2009-08-04

A gate drive for an insulated gate bipolar transistor (IGBT) includes a control and protection module coupled to a collector terminal of the IGBT, an optical communications module coupled to the control and protection module, a power supply module coupled to the control and protection module and an output power stage module with inputs coupled to the power supply module and the control and protection module, and outputs coupled to a gate terminal and an emitter terminal of the IGBT. The optical communications module is configured to send control signals to the control and protection module. The power supply module is configured to distribute inputted power to the control and protection module. The control and protection module outputs on/off, soft turn-off and/or soft turn-on signals to the output power stage module, which, in turn, supplies a current based on the signal(s) from the control and protection module for charging or discharging an input capacitance of the IGBT.

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

NASA Astrophysics Data System (ADS)

Shaheed, M. Reaz

1995-01-01

Higher speed at lower cost and at low power consumption is a driving force for today's semiconductor technology. Despite a substantial effort toward achieving this goal via alternative technologies such as III-V compounds, silicon technology still dominates mainstream electronics. Progress in silicon technology will continue for some time with continual scaling of device geometry. However, there are foreseeable limits on achievable device performance, reliability and scaling for room temperature technologies. Thus, reduced temperature operation is commonly viewed as a means for continuing the progress towards higher performance. Although silicon CMOS will be the first candidate for low temperature applications, bipolar devices will be used in a hybrid fashion, as line drivers or in limited critical path elements. Silicon -germanium-base bipolar transistors look especially attractive for low-temperature bipolar applications. At low temperatures, various new physical phenomena become important in determining device behavior. Carrier freeze-out effects which are negligible at room temperature, become of crucial importance for analyzing the low temperature device characteristics. The conventional Pearson-Bardeen model of activation energy, used for calculation of carrier freeze-out, is based on an incomplete picture of the physics that takes place and hence, leads to inaccurate results at low temperatures. Plasma -induced bandgap narrowing becomes more pronounced in device characteristics at low temperatures. Even with modern numerical simulators, this effect is not well modeled or simulated. In this dissertation, improved models for such physical phenomena are presented. For accurate simulation of carrier freeze-out, the Pearson-Bardeen model has been extended to include the temperature dependence of the activation energy. The extraction of the model is based on the rigorous, first-principle theoretical calculations available in the literature. The new model is shown

Evaluation of Enhanced Low Dose Rate Sensitivity in Discrete Bipolar Junction Transistors

NASA Technical Reports Server (NTRS)

Chen, Dakai; Ladbury Raymond; LaBel, Kenneth; Topper, Alyson; Ladbury, Raymond; Triggs, Brian; Kazmakites, Tony

2012-01-01

We evaluate the low dose rate sensitivity in several families of discrete bipolar transistors across device parameter, quality assurance level, and irradiation bias configuration. The 2N2222 showed the most significant low dose rate sensitivity, with low dose rate enhancement factor of 3.91 after 100 krad(Si). The 2N2907 also showed critical degradation levels. The devices irradiated at 10 mrad(Si)/s exceeded specifications after 40 and 50 krad(Si) for the 2N2222 and 2N2907 devices, respectively.

Effect of random inhomogeneities in the spatial distribution of radiation-induced defect clusters on carrier transport through the thin base of a heterojunction bipolar transistor upon neutron irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Puzanov, A. S.; Obolenskiy, S. V., E-mail: obolensk@rf.unn.ru; Kozlov, V. A.

We analyze the electron transport through the thin base of a GaAs heterojunction bipolar transistor with regard to fluctuations in the spatial distribution of defect clusters induced by irradiation with a fissionspectrum fast neutron flux. We theoretically demonstrate that the homogeneous filling of the working region with radiation-induced defect clusters causes minimum degradation of the dc gain of the heterojunction bipolar transistor.

Origin of 1/f PM and AM noise in bipolar junction transistor amplifiers.

PubMed

Walls, F L; Ferre-Pikal, E S; Jefferts, S R

1997-01-01

In this paper we report the results of extensive research on phase modulation (PM) and amplitude modulation (AM) noise in linear bipolar junction transistor (BJT) amplifiers. BJT amplifiers exhibit 1/f PM and AM noise about a carrier signal that is much larger than the amplifiers thermal noise at those frequencies in the absence of the carrier signal. Our work shows that the 1/f PM noise of a BJT based amplifier is accompanied by 1/f AM noise which can be higher, lower, or nearly equal, depending on the circuit implementation. The 1/f AM and PM noise in BJTs is primarily the result of 1/f fluctuations in transistor current, transistor capacitance, circuit supply voltages, circuit impedances, and circuit configuration. We discuss the theory and present experimental data in reference to common emitter amplifiers, but the analysis can be applied to other configurations as well. This study provides the functional dependence of 1/f AM and PM noise on transistor parameters, circuit parameters, and signal frequency, thereby laying the groundwork for a comprehensive theory of 1/f AM and PM noise in BJT amplifiers. We show that in many cases the 1/f PM and AM noise can be reduced below the thermal noise of the amplifier.

Thermal Simulation of Switching Pulses in an Insulated Gate Bipolar Transistor (IGBT) Power Module

DTIC Science & Technology

2015-02-01

executed with SolidWorks Flow Simulation , a computational fluid-dynamics code. The graph in Fig. 2 shows the timing and amplitudes of power pulses...defined a convective flow of air perpendicular to the bottom surface of the mounting plate, with a velocity of 10 ft/s. The thermal simulations were...Thermal Simulation of Switching Pulses in an Insulated Gate Bipolar Transistor (IGBT) Power Module by Gregory K Ovrebo ARL-TR-7210

Analysis of long-term ionizing radiation effects in bipolar transistors

NASA Technical Reports Server (NTRS)

Stanley, A. G.; Martin, K. E.

1978-01-01

The ionizing radiation effects of electrons on bipolar transistors have been analyzed using the data base from the Voyager project. The data were subjected to statistical analysis, leading to a quantitative characterization of the product and to data on confidence limits which will be useful for circuit design purposes. These newly-developed methods may form the basis for a radiation hardness assurance system. In addition, an attempt was made to identify the causes of the large variations in the sensitivity observed on different product lines. This included a limited construction analysis and a determination of significant design and processes variables, as well as suggested remedies for improving the tolerance of the devices to radiation.

Laccase/HBT and laccase-CBM/HBT treatment of softwood kraft pulp: impact on pulp bleachability and physical properties.

PubMed

Ravalason, Holy; Bertaud, Frédérique; Herpoël-Gimbert, Isabelle; Meyer, Valérie; Ruel, Katia; Joseleau, Jean-Paul; Grisel, Sacha; Olivé, Caroline; Sigoillot, Jean-Claude; Petit-Conil, Michel

2012-10-01

Pycnoporus cinnabarinus laccase and a chimeric laccase-CBM were applied in softwood kraft pulp biobleaching in the presence of 1-hydroxybenzotriazole (HBT). The presence of CBM could enhance the laccase biobleaching potential as a decrease in the enzymatic charge and chlorine dioxide consumption, as well as an increase in pulp brightness were observed. Laccase/HBT treatment could be improved by increasing oxygen pressure from 1 to 3bar and pulp consistency from 5% to 10%. Conversely, under the same conditions, no improvement of laccase-CBM/HBT treatment was observed, indicating a different behavior of both systems. However, laccase-CBM/HBT treatment led to a better preservation of pulp properties. This effect was probably due to fiber surface modifications involving the action of the CBM. Transmission electron microscopy examination of pulp fibers indicated a retention of laccase-CBM inside the pulp fibers due to CBM binding and an increased external microfibrillation of the fibers due to enzymatic treatments. Copyright © 2012 Elsevier Ltd. All rights reserved.

Thermal Simulation of a Silicon Carbide (SiC) Insulated-Gate Bipolar Transistor (IGBT) in Continuous Switching Mode

DTIC Science & Technology

operation in a DC-DC power converter switching at a frequency of up to 15 kHz. Calculations also estimated the effect of solder layers on temperature in the device....Thermal simulations were used to calculate temperatures in a silicon carbide (SiC) Insulated -Gate Bipolar Transistor (IGBT),simulating device

Type-II GaAsSb/InP heterojunction bipolar light-emitting transistor

NASA Astrophysics Data System (ADS)

Feng, M.; Holonyak, N.; Chu-Kung, B.; Walter, G.; Chan, R.

2004-06-01

We report radiative recombination in the base layer of Type-II InP/GaAsSb/InP double heterojunction bipolar light-emitting transistors (HBLET) operating in the common-emitter configuration. The typical current gain, β, for a 120×120 μm2 emitter area of the HBLET is 38. The optical emission wavelength from a 30 nm GaAs0.51Sb0.49 base is centered at λpeak=1600 nm. Three-port operation of the Type-II HBLET with simultaneously an amplified electrical output and an optical output with signal modulation is demonstrated at 10 kHz.

Hardening measures for bipolar transistors against microwave-induced damage

NASA Astrophysics Data System (ADS)

Chai, Chang-Chun; Ma, Zhen-Yang; Ren, Xing-Rong; Yang, Yin-Tang; Zhao, Ying-Bo; Yu, Xin-Hai

2013-06-01

In the present paper we study the influences of the bias voltage and the external components on the damage progress of a bipolar transistor induced by high-power microwaves. The mechanism is presented by analyzing the variation in the internal distribution of the temperature in the device. The findings show that the device becomes less vulnerable to damage with an increase in bias voltage. Both the series diode at the base and the relatively low series resistance at the emitter, Re, can obviously prolong the burnout time of the device. However, Re will aid damage to the device when the value is sufficiently high due to the fact that the highest hot spot shifts from the base-emitter junction to the base region. Moreover, the series resistance at the base Rb will weaken the capability of the device to withstand microwave damage.

Correlation of a Bipolar-Transistor-Based Neutron Displacement Damage Sensor Methodology with Proton Irradiations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tonigan, Andrew M.; Arutt, Charles N.; Parma, Edward J.

For this research, a bipolar-transistor-based sensor technique has been used to compare silicon displacement damage from known and unknown neutron energy spectra generated in nuclear reactor and high-energy-density physics environments. The technique has been shown to yield 1-MeV(Si) equivalent neutron fluence measurements comparable to traditional neutron activation dosimetry. This study significantly extends previous results by evaluating three types of bipolar devices utilized as displacement damage sensors at a nuclear research reactor and at a Pelletron particle accelerator. Ionizing dose effects are compensated for via comparisons with 10-keV x-ray and/or cobalt-60 gamma ray irradiations. Non-ionizing energy loss calculations adequately approximate themore » correlations between particle-device responses and provide evidence for the use of one particle type to screen the sensitivity of the other.« less

Correlation of a Bipolar-Transistor-Based Neutron Displacement Damage Sensor Methodology with Proton Irradiations

DOE PAGES

Tonigan, Andrew M.; Arutt, Charles N.; Parma, Edward J.; ...

2017-11-16

For this research, a bipolar-transistor-based sensor technique has been used to compare silicon displacement damage from known and unknown neutron energy spectra generated in nuclear reactor and high-energy-density physics environments. The technique has been shown to yield 1-MeV(Si) equivalent neutron fluence measurements comparable to traditional neutron activation dosimetry. This study significantly extends previous results by evaluating three types of bipolar devices utilized as displacement damage sensors at a nuclear research reactor and at a Pelletron particle accelerator. Ionizing dose effects are compensated for via comparisons with 10-keV x-ray and/or cobalt-60 gamma ray irradiations. Non-ionizing energy loss calculations adequately approximate themore » correlations between particle-device responses and provide evidence for the use of one particle type to screen the sensitivity of the other.« less

Collector modulation in high-voltage bipolar transistor in the saturation mode: Analytical approach

NASA Astrophysics Data System (ADS)

Dmitriev, A. P.; Gert, A. V.; Levinshtein, M. E.; Yuferev, V. S.

2018-04-01

A simple analytical model is developed, capable of replacing the numerical solution of a system of nonlinear partial differential equations by solving a simple algebraic equation when analyzing the collector resistance modulation of a bipolar transistor in the saturation mode. In this approach, the leakage of the base current into the emitter and the recombination of non-equilibrium carriers in the base are taken into account. The data obtained are in good agreement with the results of numerical calculations and make it possible to describe both the motion of the front of the minority carriers and the steady state distribution of minority carriers across the collector in the saturation mode.

Proton Irradiation as a Screen for Displacement-Damage Sensitivity in Bipolar Junction Transistors

NASA Astrophysics Data System (ADS)

Arutt, Charles N.; Warren, Kevin M.; Schrimpf, Ronald D.; Weller, Robert A.; Kauppila, Jeffrey S.; Rowe, Jason D.; Sternberg, Andrew L.; Reed, Robert A.; Ball, Dennis R.; Fleetwood, Daniel M.

2015-12-01

NPN and PNP bipolar junction transistors of varying sizes are irradiated with 4-MeV protons and 10-keV X-rays to determine the amount of ionization-related degradation caused by protons and calculate an improved estimate of displacement-related degradation due to protons. While different ratios of degradation produced by displacement damage and ionization effects will occur for different device technologies, this general approach, with suitable margin, can be used as a screen for sensitivity to neutron-induced displacement damage. Further calculations are performed to estimate the amount of degradation produced by 1-MeV equivalent neutron displacement damage compared to that produced by the displacement damage due to protons. The results are compared to previous work.

Theoretical and experimental characterization of the DUal-BAse transistor (DUBAT)

NASA Astrophysics Data System (ADS)

Wu, Chung-Yu; Wu, Ching-Yuan

1980-11-01

A new A-type integrated voltage controlled differential negative resistance device using an extra effective base region to form a lateral pnp (npn) bipolar transistor beside the original base region of a vertical npn (pnp) bipolar junction transistor, and so called the DUal BAse Transistor (DUBAT), is studied both experimentally and theoretically, The DUBAT has three terminals and is fully comparible with the existing bipolar integrated circuits technologies. Based upon the equivalent circuit of the DUBAT, a simple first-order analytical theory is developed, and important device parameters, such as: the I-V characteristic, the differential negative resistance, and the peak and valley points, are also characterized. One of the proposed integrated structures of the DUBAT, which is similar in structure to I 2L but with similar high density and a normally operated vertical npn transistor, has been successfully fabricated and studied. Comparisons between the experimental data and theoretical analyses are made, and show in satisfactory agreements.

Field effect transistors improve buffer amplifier

NASA Technical Reports Server (NTRS)

1967-01-01

Unity gain buffer amplifier with a Field Effect Transistor /FET/ differential input stage responds much faster than bipolar transistors when operated at low current levels. The circuit uses a dual FET in a unity gain buffer amplifier having extremely high input impedance, low bias current requirements, and wide bandwidth.

Mixing-Chamber Preamplifier for Spin Qubit Readout

NASA Astrophysics Data System (ADS)

Curry, Matthew; Mounce, Andrew; England, Troy; Manginell, Ronald; Wendt, Joel; Pluym, Tammy; Carr, Stephen; Carroll, Malcolm

Spin qubit states are often read out with a nearby charge sensor. To improve signal-to-noise ratio (SNR) and bandwidth, we amplify a charge sensor with a low-current-bias, silicon-germanium heterojunction-bipolar-transistor (HBT). The HBT is located at the mixing chamber of a dilution refrigerator, which minimizes parasitic capacitance and amplifies signal before fridge noise is introduced. Using the HBT-charge-sensor circuit, we tune a few-electron quantum dot (QD) into resonance with a donor-like object and observe singlet-triplet (ST) behavior. ST separation in this MOS donor-implanted-QD molecular system is measured using magnetospectroscopy to be approximately 100 μeV. The low current bias of the HBT minimizes both heating of the charge-sensed QD as well as maintains an overall low power at the mixing chamber. HBT bias impact on QD electron temperature is examined and we find that the HBT preamplifier can operate at around 100 nW with a current gain of around 500 without influencing the electron temperature, which is around 150 mK. We will also examine single-shot readout of a charge state using the HBT preamplifier. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

A transistor based on 2D material and silicon junction

NASA Astrophysics Data System (ADS)

Kim, Sanghoek; Lee, Seunghyun

2017-07-01

A new type of graphene-silicon junction transistor based on bipolar charge-carrier injection was designed and investigated. In contrast to many recent studies on graphene field-effect transistor (FET), this device is a new type of bipolar junction transistor (BJT). The transistor fully utilizes the Fermi level tunability of graphene under bias to increase the minority-carrier injection efficiency of the base-emitter junction in the BJT. Single-layer graphene was used to form the emitter and the collector, and a p-type silicon was used as the base. The output of this transistor was compared with a metal-silicon junction transistor ( i.e. surface-barrier transistor) to understand the difference between a graphene-silicon junction and metal-silicon Schottky junction. A significantly higher current gain was observed in the graphene-silicon junction transistor as the base current was increased. The graphene-semiconductor heterojunction transistor offers several unique advantages, such as an extremely thin device profile, a low-temperature (< 110 °C) fabrication process, low cost (no furnace process), and high-temperature tolerance due to graphene's stability. A transistor current gain ( β) of 33.7 and a common-emitter amplifier voltage gain of 24.9 were achieved.

Design and implementation of GaAs HBT circuits with ACME

NASA Technical Reports Server (NTRS)

Hutchings, Brad L.; Carter, Tony M.

1993-01-01

GaAs HBT circuits offer high performance (5-20 GHz) and radiation hardness (500 Mrad) that is attractive for space applications. ACME is a CAD tool specifically developed for HBT circuits. ACME implements a novel physical schematic-capture design technique where designers simultaneously view the structure and physical organization of a circuit. ACME's design interface is similar to schematic capture; however, unlike conventional schematic capture, designers can directly control the physical placement of both function and interconnect at the schematic level. In addition, ACME provides design-time parasitic extraction, complex wire models, and extensions to Multi-Chip Modules (MCM's). A GaAs HBT gate-array and semi-custom circuits have been developed with ACME; several circuits have been fabricated and found to be fully functional .

Black Silicon Germanium (SiGe) for Extended Wavelength Near Infrared Electro-optical Applications

DTIC Science & Technology

2010-05-01

samples were dipped in an aqueous solution of iodine (I) and potassium iodide (KI) (25 gm I and 100 gm KI per liter of water [H2O] ) (16). The samples...Satterfield, C. N.; Wentworth, R. L. in Hydrogen Peroxide , Reinhold Publishing, New York, 1955, p. 370. 12 19. Kishioka, K.; Horita, S.; Ohdaria, K...germanium H2O water HBT heterojunction bipolar transistor I iodine IPA isopropal alcohol KI potassium iodide MEE metal enhanced etching

Analysis of the dynamic avalanche of carrier stored trench bipolar transistor (CSTBT) during clamped inductive turn-off transient

NASA Astrophysics Data System (ADS)

Xue, Peng; Fu, Guicui

2017-03-01

The dynamic avalanche has a huge impact on the switching robustness of carrier stored trench bipolar transistor (CSTBT). The purpose of this work is to investigate the CSTBT's dynamic avalanche mechanism during clamped inductive turn-off transient. At first, with a Mitsubishi 600 V/150 A CSTBT and a Infineon 600 V/200 A field stop insulated gate bipolar transistor (FS-IGBT) utilized, the clamped inductive turn-off characteristics are obtained by double pulse test. The unclamped inductive switching (UIS) test is also utilized to identify the CSTBT's clamping voltage under dynamic avalanche condition. After the test data analysis, it is found that the CSTBT's dynamic avalanche is abnormal and can be triggered under much looser condition than the conventional buffer layer IGBT. The comparison between the FS-IGBT and CSTBT's experimental results implies that the CSTBT's abnormal dynamic avalanche phenomenon may be induced by the carrier storage (CS) layer. Based on the semiconductor physics, the electric field distribution and dynamic avalanche generation in the depletion region are analyzed. The analysis confirms that the CS layer is the root cause of the CSTBT's abnormal dynamic avalanche mechanism. Moreover, the CSTBT's negative gate capacitance effect is also investigated to clarify the underlying mechanism of the gate voltage bump observed in the test. In the end, the mixed-mode numerical simulation is utilized to reproduce the CSTBT's dynamic avalanche behavior. The simulation results validate the proposed dynamic avalanche mechanisms.

Carbon reactivation kinetics in the base of heterojunction GaInP-GaAs bipolar transistors

NASA Astrophysics Data System (ADS)

Mimila-Arroyo, J.; Bland, S. W.; Chevallier, J.

2002-05-01

The reactivation kinetics of carbon acceptors in the base region of GaInP/GaAs heterojunction bipolar transistors was studied. The reactivation was achieved by ex situ thermal annealing, through a multistage annealing experiment where the carrier concentration was monitored at each stage. Results indicate that carbon reactivation follows a first-order kinetics process in which the activation energy appears to be the sum of the energy needed to debond the hydrogen from the carbon-hydrogen complex, and the energy necessary to overcome the electrostatic junction barrier. The reactivation constant is thermally activated with an activation energy of 2.83 eV and an attempt frequency of 1.2×1013 s-1.

Application of the Johnson criteria to graphene transistors

NASA Astrophysics Data System (ADS)

Kelly, M. J.

2013-12-01

For 60 years, the Johnson criteria have guided the development of materials and the materials choices for field-effect and bipolar transistor technology. Intrinsic graphene is a semi-metal, precluding transistor applications, but only under lateral bias is a gap opened and transistor action possible. This first application of the Johnson criteria to biased graphene suggests that this material will struggle to ever achieve competitive commercial applications.

Open-tube diffusion techniques for InP/LnGaAs heterojunctior bipolar transistors

NASA Astrophysics Data System (ADS)

Schuitemaker, P.; Houston, P. A.

1986-11-01

Open-tube diffusion techniques used between 450 and 600° C are described which involve the supply of diffusant from a vapour source (via a solution) and a solid evaporated metal source. Investigations of Zn into InP and InGaAs(P) have been undertaken using both sources. SIMS profile analyses show that in the case of the vapour source the profiles indicate a concentration-dependent diffusion coefficient while the solid source diffusions can be well described by a Gaussian-type profile. The usefulness of the vapour source method has been demonstrated in the fabrication of bipolar transistors which exhibit good d.c. characteristics. The solid source method is limited by the slow diffusion velocity and more gradual profile. The InGaAs(P)/InP materials system has important applications in optical communications and future high speed microwave and switching devices. Useful technologies allied to the introduction of impurities into Si by diffusion, have gradually been emerging for use in the III-V semiconductor family. Closed tube systems1 have been used in order to contain the volatile group V species and prevent surface erosion. In addition, simpler open tube systems2,3 have been developed that maintain a sufficient overpressure of the group V element. Zn and Cd p-dopants have been studied extensively because of the volatility and relatively large diffusion rates in III-V semiconductors. Opentube diffusion into both InP and InGaAs2-6 has been studied but little detail has appeared concerning InGaAs and InGaAsP. In this paper we describe a comprehensive study of the diffusion of Zn into InP and InGaAs(P) using both open-tube vapour source and a Au/Zn/Au evaporated solid source with SiNx acting both as a mask and also an encapsulant to prevent loss of Zn and decomposition of the substrate material. The techniques have been successfully applied to the fabrication of InP/lnGaAs heterojunction bipolar transistors which show good dc characteristics. Reference to InGaAs in

Comparing SiGe HBT Amplifier Circuits for Fast Single-shot Spin Readout

NASA Astrophysics Data System (ADS)

England, Troy; Curry, Matthew; Carr, Stephen; Mounce, Andrew; Jock, Ryan; Sharma, Peter; Bureau-Oxton, Chloe; Rudolph, Martin; Hardin, Terry; Carroll, Malcolm

Fast, low-power quantum state readout is one of many challenges facing quantum information processing. Single electron transistors (SETs) are potentially fast, sensitive detectors for performing spin readout. From a circuit perspective, however, their output impedance and nonlinear conductance are ill suited to drive the parasitic capacitance of coaxial conductors used in cryogenic environments, necessitating a cryogenic amplification stage. We will compare two amplifiers based on single-transistor circuits implemented with silicon germanium heterojunction bipolar transistors. Both amplifiers provide gain at low power levels, but the dynamics of each circuit vary significantly. We will explore the gain mechanisms, linearity, and noise of each circuit and explain the situations in which each amplifier is best used. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

Synergistic effect of mixed neutron and gamma irradiation in bipolar operational amplifier OP07

NASA Astrophysics Data System (ADS)

Yan, Liu; Wei, Chen; Shanchao, Yang; Xiaoming, Jin; Chaohui, He

2016-09-01

This paper presents the synergistic effects in bipolar operational amplifier OP07. The radiation effects are studied by neutron beam, gamma ray, and mixed neutron/gamma ray environments. The characterateristics of the synergistic effects are studied through comparison of different experiment results. The results show that the bipolar operational amplifier OP07 exhibited significant synergistic effects in the mixed neutron and gamma irradiation. The bipolar transistor is identified as the most radiation sensitive unit of the operational amplifier. In this paper, a series of simulations are performed on bipolar transistors in different radiation environments. In the theoretical simulation, the geometric model and calculations based on the Medici toolkit are built to study the radiation effects in bipolar components. The effect of mixed neutron and gamma irradiation is simulated based on the understanding of the underlying mechanisms of radiation effects in bipolar transistors. The simulated results agree well with the experimental data. The results of the experiments and simulation indicate that the radiation effects in the bipolar devices subjected to mixed neutron and gamma environments is not a simple combination of total ionizing dose (TID) effects and displacement damage. The data suggests that the TID effect could enhance the displacement damage. The synergistic effect should not be neglected in complex radiation environments.

Lateral carrier diffusion and current gain in terahertz InGaAs/InP double-heterojunction bipolar transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiang, Han-Wei; Rode, Johann C.; Choudhary, Prateek

2014-01-21

The DC current gain in In{sub 0.53}Ga{sub 0.47}As/InP double-heterojunction bipolar transistors is computed based on a drift-diffusion model, and is compared with experimental data. Even in the absence of other scaling effects, lateral diffusion of electrons to the base Ohmic contacts causes a rapid reduction in DC current gain as the emitter junction width and emitter-base contact spacing are reduced. The simulation and experimental data are compared in order to examine the effect of carrier lateral diffusion on current gain. The impact on current gain due to device scaling and approaches to increase current gain are discussed.

A comparative study on electrical characteristics of 1-kV pnp and npn SiC bipolar junction transistors

NASA Astrophysics Data System (ADS)

Okuda, Takafumi; Kimoto, Tsunenobu; Suda, Jun

2018-04-01

We investigate the electrical characteristics of 1-kV pnp SiC bipolar junction transistors (BJTs) and compare them with those of npn SiC BJTs. The base resistance, current gain, and blocking capability are characterized. It is found that the base resistance of pnp SiC BJTs is two orders of magnitude lower than that of npn SiC BJTs. However, the obtained current gains are low below unity in pnp SiC BJTs, whereas npn SiC BJTs exhibit a current gain of 14 without surface passivation. The reason for the poor current gain of pnp SiC BJTs is discussed.

MOSFET-BJT hybrid mode of the gated lateral bipolar junction transistor for C-reactive protein detection.

PubMed

Yuan, Heng; Kwon, Hyurk-Choon; Yeom, Se-Hyuk; Kwon, Dae-Hyuk; Kang, Shin-Won

2011-10-15

In this study, we propose a novel biosensor based on a gated lateral bipolar junction transistor (BJT) for biomaterial detection. The gated lateral BJT can function as both a BJT and a metal-oxide-semiconductor field-effect transistor (MOSFET) with both the emitter and source, and the collector and drain, coupled. C-reactive protein (CRP), which is an important disease marker in clinical examinations, can be detected using the proposed device. In the MOSFET-BJT hybrid mode, the sensitivity, selectivity, and reproducibility of the gated lateral BJT for biosensors were evaluated in this study. According to the results, in the MOSFET-BJT hybrid mode, the gated lateral BJT shows good selectivity and reproducibility. Changes in the emitter (source) current of the device for CRP antigen detection were approximately 0.65, 0.72, and 0.80 μA/decade at base currents of -50, -30, and -10 μA, respectively. The proposed device has significant application in the detection of certain biomaterials that require a dilution process using a common biosensor, such as a MOSFET-based biosensor. Copyright © 2011 Elsevier B.V. All rights reserved.

The bipolar silicon microstrip detector: A proposal for a novel precision tracking device

NASA Astrophysics Data System (ADS)

Horisberger, R.

1990-03-01

It is proposed to combine the technology of fully depleted silicon microstrip detectors fabricated on n doped high resistivity silicon with the concept of the bipolar transistor. This is done by adding a n ++ doped region inside the normal p + implanted region of the reverse biased p + n diode. Teh resulting structure has amplifying properties and is referred to as bipolar pixel transistor. The simplest readout scheme of a bipolar pixel array by an aluminium strip bus leads to the bipolar microstrip detector. The bipolar pixel structure is expected to give a better signal-to-noise performance for the detection of minimum ionizing charged particle tracks than the normal silicon diode strip detector and therefore should allow in future the fabrication of thinner silicon detectors for precision tracking.

Junction-to-Case Thermal Resistance of a Silicon Carbide Bipolar Junction Transistor Measured

NASA Technical Reports Server (NTRS)

Niedra, Janis M.

2006-01-01

Junction temperature of a prototype SiC-based bipolar junction transistor (BJT) was estimated by using the base-emitter voltage (V(sub BE)) characteristic for thermometry. The V(sub BE) was measured as a function of the base current (I(sub B)) at selected temperatures (T), all at a fixed collector current (I(sub C)) and under very low duty cycle pulse conditions. Under such conditions, the average temperature of the chip was taken to be the same as that of the temperature-controlled case. At increased duty cycle such as to substantially heat the chip, but same I(sub C) pulse height, the chip temperature was identified by matching the V(sub BE) to the thermometry curves. From the measured average power, the chip-to-case thermal resistance could be estimated, giving a reasonable value. A tentative explanation for an observed bunching with increasing temperature of the calibration curves may relate to an increasing dopant atom ionization. A first-cut analysis, however, does not support this.

K-Band Si/SiGe HBT MMIC Amplifiers Using Lumped Passive Components with a Micromachined Structure

NASA Technical Reports Server (NTRS)

Lu, Liang-Hung; Rieh, Jae-Sung; Bhattacharya, Pallab; Katechi, Linda P. B.; Croke, E. T.; Ponchak, George E.; Alterovitz, Samuel A.

2000-01-01

Using Si/SiGe heterojunction bipolar transistors with a maximum oscillation frequency of 52 GHz and a novel structure for passive components, a two-stage K-band lumped-element amplifier has been designed and fabricated on high-resistivity Si substrates. The chip size including biasing and RF chokes is 0.92 x 0.67 sq mm.

Nonlinear system analysis in bipolar integrated circuits

NASA Astrophysics Data System (ADS)

Fang, T. F.; Whalen, J. J.

1980-01-01

Since analog bipolar integrated circuits (IC's) have become important components in modern communication systems, the study of the Radio Frequency Interference (RFI) effects in bipolar IC amplifiers is an important subject for electromagnetic compatibility (EMC) engineering. The investigation has focused on using the nonlinear circuit analysis program (NCAP) to predict RF demodulation effects in broadband bipolar IC amplifiers. The audio frequency (AF) voltage at the IC amplifier output terminal caused by an amplitude modulated (AM) RF signal at the IC amplifier input terminal was calculated and compared to measured values. Two broadband IC amplifiers were investigated: (1) a cascode circuit using a CA3026 dual differential pair; (2) a unity gain voltage follower circuit using a micro A741 operational amplifier (op amp). Before using NCAP for RFI analysis, the model parameters for each bipolar junction transistor (BJT) in the integrated circuit were determined. Probe measurement techniques, manufacturer's data, and other researcher's data were used to obtain the required NCAP BJT model parameter values. An important contribution included in this effort is a complete set of NCAP BJT model parameters for most of the transistor types used in linear IC's.

An Evaluation of Bipolar Junction Transistors as Dosimeter for Megavoltage Electron Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Passos, Renan Garcia de; Vidal da Silva, Rogerio Matias; Silva, Malana Marcelina Almeida

Dosimetry is an extremely important field in medical applications of radiation and nowadays, electron beam is a good option for superficial tumor radiotherapy. Normally, the applied dose to the patient both in diagnostic and therapy must be monitored to prevent injuries and ensure the success of the treatment, therefore, we should always look for improving of the dosimetric methods. Accordingly, the aim of this work is about the use of a bipolar junction transistor (BJT) for electron beam dosimetry. After previous studies, such an electronic device can work as a dosimeter when submitted to ionizing radiation of photon beam. Actually,more » a typical BJT consists of two PN semiconductor junctions resulting in the NPN structure device, for while, and each semiconductor is named as collector (C), base (B) and emitter (E), respectively. Although the transistor effect, which corresponds to the current amplification, be accurately described by the quantum physics, one can utilize a simple concept from the circuit theory: the base current IB (input signal) is amplified by a factor of β resulting in the collector current IC (output signal) at least one hundred times greater the IB. In fact, the BJT is commonly used as a current amplifier with gain β=I{sub C}/I{sub B}, therefore, it was noticed that this parameter is altered when the device is exposed to ionizing radiation. The current gain alteration can be explained by the trap creation and the positive charges build up, beside the degradation of the lattice structure. Then, variations of the gain of irradiated transistors may justify their use as a dosimeter. Actually, the methodology is based on the measurements of the I{sub C} variations whereas I{sub B} is maintained constant. BC846 BJT type was used for dose monitoring from passive-mode measurements: evaluation of its electrical characteristic before and after irradiation procedure. Thus, IC readings were plotted as a function of the applied dose in 6 Me

A 32-bit Ultrafast Parallel Correlator using Resonant Tunneling Devices

NASA Technical Reports Server (NTRS)

Kulkarni, Shriram; Mazumder, Pinaki; Haddad, George I.

1995-01-01

An ultrafast 32-bit pipeline correlator has been implemented using resonant tunneling diodes (RTD) and hetero-junction bipolar transistors (HBT). The negative differential resistance (NDR) characteristics of RTD's is the basis of logic gates with the self-latching property that eliminates pipeline area and delay overheads which limit throughput in conventional technologies. The circuit topology also allows threshold logic functions such as minority/majority to be implemented in a compact manner resulting in reduction of the overall complexity and delay of arbitrary logic circuits. The parallel correlator is an essential component in code division multi-access (CDMA) transceivers used for the continuous calculation of correlation between an incoming data stream and a PN sequence. Simulation results show that a nano-pipelined correlator can provide and effective throughput of one 32-bit correlation every 100 picoseconds, using minimal hardware, with a power dissipation of 1.5 watts. RTD plus HBT based logic gates have been fabricated and the RTD plus HBT based correlator is compared with state of the art complementary metal oxide semiconductor (CMOS) implementations.

Quantum Thermal Transistor.

PubMed

Joulain, Karl; Drevillon, Jérémie; Ezzahri, Younès; Ordonez-Miranda, Jose

2016-05-20

We demonstrate that a thermal transistor can be made up with a quantum system of three interacting subsystems, coupled to a thermal reservoir each. This thermal transistor is analogous to an electronic bipolar one with the ability to control the thermal currents at the collector and at the emitter with the imposed thermal current at the base. This is achieved by determining the heat fluxes by means of the strong-coupling formalism. For the case of three interacting spins, in which one of them is coupled to the other two, that are not directly coupled, it is shown that high amplification can be obtained in a wide range of energy parameters and temperatures. The proposed quantum transistor could, in principle, be used to develop devices such as a thermal modulator and a thermal amplifier in nanosystems.

Method for double-sided processing of thin film transistors

DOEpatents

Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.; Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang

2008-04-08

This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

Transistor Laser Optical NOR Gate for High Speed Optical Logic Processors

DTIC Science & Technology

2017-03-20

proposes an optical bistable latch can be built with two universal photonic NOR gate circuits, which are implemented by the three-port tunneling ... Tunneling Junction Transistor Laser (TJ-TL); Optical NOR Gate. Introduction To fulfill the future national security and intelligence needs in this...two-terminal diode lasers. Three-Port Transistor Laser – an Integration of Quantum-Wells into Heterojunction Bipolar Transistor Different than

Passivation of InP heterojunction bipolar transistors by strain controlled plasma assisted electron beam evaporated hafnium oxide

NASA Astrophysics Data System (ADS)

Driad, R.; Sah, R. E.; Schmidt, R.; Kirste, L.

2012-01-01

We present structural, stress, and electrical properties of plasma assisted e-beam evaporated hafnium dioxide (HfO2) layers on n-type InP substrates. These layers have subsequently been used for surface passivation of InGaAs/InP heterostructure bipolar transistors either alone or in combination with plasma enhanced chemical vapor deposited SiO2 layers. The use of stacked HfO2/SiO2 results in better interface quality with InGaAs/InP heterostructures, as illustrated by smaller leakage current and improved breakdown voltage. These improvements can be attributed to the reduced defect density and charge trapping at the dielectric-semiconductor interface. The deposition at room temperature makes these films suitable for sensitive devices.

Silicon direct bonding approach to high voltage power device (insulated gate bipolar transistors)

NASA Astrophysics Data System (ADS)

Cha, Giho; Kim, Youngchul; Jang, Hyungwoo; Kang, Hyunsoon; Song, Changsub

2001-10-01

Silicon direct bonding technique was successfully applied for the fabrication of high voltage IGBT (Insulated Gate Bipolar Transistor). In this work, 5 inch, p-type CZ wafer for handle wafer and n-type FZ wafer for device wafer were used and bonding the two wafers was performed at reduced pressure (1mmTorr) using a modified vacuum bonding machine. Since the breakdown voltage in high voltage device has been determined by the remained thickness of device layer, grinding and CMP steps should be carefully designed in order to acquire better uniformity of device layer. In order to obtain the higher removal rate and the final better uniformity of device layer, the harmony of the two processes must be considered. We found that the concave type of grinding profile and the optimal thickness of ground wafer was able to reduce the process time of CMP step and also to enhance the final thickness uniformity of device layer up to +/- 1%. Finally, when compared epitaxy layer with SDB wafer, the SDB wafer was found to be more favorable in terms of cost and electrical characteristics.

Development of Si/SiGe heterostructures

NASA Astrophysics Data System (ADS)

Hauenstein, R. J.; Veteran, J. L.; Young, M. H.

1991-01-01

New molecular beam epitaxy (MBE) materials growth and doping processes were developed for the fabrication of Si/SiGe heterostructure devices. These new materials processes are applied to the demonstration of cryogenic n-p-n Si/Si 1-x Gex/Si heterojunction bipolar transistors (HBT). This application has special significance as an enabling DoD technology for fast low noise, high performance readout and signal processing circuits for IR focal systems. Reliable, versatile methods were developed to grow very high quality Si/SiGe strained layer heterostructures and multilayers. In connection with this program methods were developed to dope the Si and SiGe with B, Sb and Ga. B and Sb were found to be the preferred dopants for p and n regions respectively, of the HBT devices. The test devices clearly displayed gain enhancement due to the heterojunction and provided useful gains from room temperature down to 10 K.

HBT+: an improved code for finding subhaloes and building merger trees in cosmological simulations

NASA Astrophysics Data System (ADS)

Han, Jiaxin; Cole, Shaun; Frenk, Carlos S.; Benitez-Llambay, Alejandro; Helly, John

2018-02-01

Dark matter subhalos are the remnants of (incomplete) halo mergers. Identifying them and establishing their evolutionary links in the form of merger trees is one of the most important applications of cosmological simulations. The HBT (Hierachical Bound-Tracing) code identifies haloes as they form and tracks their evolution as they merge, simultaneously detecting subhaloes and building their merger trees. Here we present a new implementation of this approach, HBT+ , that is much faster, more user friendly, and more physically complete than the original code. Applying HBT+ to cosmological simulations, we show that both the subhalo mass function and the peak-mass function are well fitted by similar double-Schechter functions. The ratio between the two is highest at the high-mass end, reflecting the resilience of massive subhaloes that experience substantial dynamical friction but limited tidal stripping. The radial distribution of the most-massive subhaloes is more concentrated than the universal radial distribution of lower mass subhaloes. Subhalo finders that work in configuration space tend to underestimate the masses of massive subhaloes, an effect that is stronger in the host centre. This may explain, at least in part, the excess of massive subhaloes in galaxy cluster centres inferred from recent lensing observations. We demonstrate that the peak-mass function is a powerful diagnostic of merger tree defects, and the merger trees constructed using HBT+ do not suffer from the missing or switched links that tend to afflict merger trees constructed from more conventional halo finders. We make the HBT+ code publicly available.

Monolithically Integrated SiGe/Si PIN-HBT Front-End Transimpedance Photoreceivers

NASA Technical Reports Server (NTRS)

Rieh, J.-S.; Qasaimeh, O.; Klotzkin, D.; Lu, L.-H.; Katehi, L. P. B.; Yang, K.; Bhattacharya, P.; Croke, E. T.

1997-01-01

The demand for monolithically integrated photoreceivers based on Si-based technology keeps increasing as low cost and high reliability products are required for the expanding commercial market. Higher speed and wider operating frequency range are expected when SiGe/Si heterojunction is introduced to the circuit design. In this paper, a monolithic SiGe/Si PIN-HBT front-end transimpedance photoreceiver is demonstrated for the first time. For this purpose, mesa-type SiGe/Si PIN-HBT technology was developed. Fabricated HBTs exhibit f(sub max) of 34 GHz with DC gain of 25. SiGe/Si PIN photodiodes, which share base and collector layers of HBTs, demonstrate responsivity of 0.3 A/W at lambda=850 nm and bandwidth of 450 MHz. Based on these devices, single- and dual-feedback transimpedance amplifiers were fabricated and they exhibited the bandwidth of 3.2 GHz and 3.3 GHz with the transimpedance gain of 45.2 dB(Omega) and 47.4 dB(Omega) respectively. Monolithically integrated single-feedback PIN-HBT photoreceivers were implemented and the bandwidth was measured to be approx. 0.5 GHz, which is limited by the bandwidth of PIN photodiodes.

Stochastic Gain Degradation in III-V Heterojunction Bipolar Transistors due to Single Particle Displacement Damage

DOE PAGES

Vizkelethy, Gyorgy; Bielejec, Edward S.; Aguirre, Brandon A.

2017-11-13

As device dimensions decrease single displacement effects are becoming more important. We measured the gain degradation in III-V Heterojunction Bipolar Transistors due to single particles using a heavy ion microbeam. Two devices with different sizes were irradiated with various ion species ranging from oxygen to gold to study the effect of the irradiation ion mass on the gain change. From the single steps in the inverse gain (which is proportional to the number of defects) we calculated Cumulative Distribution Functions to help determine design margins. The displacement process was modeled using the Marlowe Binary Collision Approximation (BCA) code. The entiremore » structure of the device was modeled and the defects in the base-emitter junction were counted to be compared to the experimental results. While we found good agreement for the large device, we had to modify our model to reach reasonable agreement for the small device.« less

Heat removal from bipolar transistor by loop heat pipe with nickel and copper porous structures.

PubMed

Nemec, Patrik; Smitka, Martin; Malcho, Milan

2014-01-01

Loop heat pipes (LHPs) are used in many branches of industry, mainly for cooling of electrical elements and systems. The loop heat pipe is a vapour-liquid phase-change device that transfers heat from evaporator to condenser. One of the most important parts of the LHP is the porous wick structure. The wick structure provides capillary force to circulate the working fluid. To achieve good thermal performance of LHP, capillary wicks with high permeability and porosity and fine pore radius are expected. The aim of this work was to develop porous structures from copper and nickel powder with different grain sizes. For experiment copper powder with grain size of 50 and 100 μm and nickel powder with grain size of 10 and 25 μm were used. Analysis of these porous structures and LHP design are described in the paper. And the measurements' influences of porous structures in LHP on heat removal from the insulated gate bipolar transistor (IGBT) have been made.

Heat Removal from Bipolar Transistor by Loop Heat Pipe with Nickel and Copper Porous Structures

PubMed Central

Smitka, Martin; Malcho, Milan

2014-01-01

Loop heat pipes (LHPs) are used in many branches of industry, mainly for cooling of electrical elements and systems. The loop heat pipe is a vapour-liquid phase-change device that transfers heat from evaporator to condenser. One of the most important parts of the LHP is the porous wick structure. The wick structure provides capillary force to circulate the working fluid. To achieve good thermal performance of LHP, capillary wicks with high permeability and porosity and fine pore radius are expected. The aim of this work was to develop porous structures from copper and nickel powder with different grain sizes. For experiment copper powder with grain size of 50 and 100 μm and nickel powder with grain size of 10 and 25 μm were used. Analysis of these porous structures and LHP design are described in the paper. And the measurements' influences of porous structures in LHP on heat removal from the insulated gate bipolar transistor (IGBT) have been made. PMID:24959622

Stochastic Gain Degradation in III-V Heterojunction Bipolar Transistors due to Single Particle Displacement Damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vizkelethy, Gyorgy; Bielejec, Edward S.; Aguirre, Brandon A.

As device dimensions decrease single displacement effects are becoming more important. We measured the gain degradation in III-V Heterojunction Bipolar Transistors due to single particles using a heavy ion microbeam. Two devices with different sizes were irradiated with various ion species ranging from oxygen to gold to study the effect of the irradiation ion mass on the gain change. From the single steps in the inverse gain (which is proportional to the number of defects) we calculated Cumulative Distribution Functions to help determine design margins. The displacement process was modeled using the Marlowe Binary Collision Approximation (BCA) code. The entiremore » structure of the device was modeled and the defects in the base-emitter junction were counted to be compared to the experimental results. While we found good agreement for the large device, we had to modify our model to reach reasonable agreement for the small device.« less

Bipolar-power-transistor-based limiter for high frequency ultrasound imaging systems.

PubMed

Choi, Hojong; Yang, Hao-Chung; Shung, K Kirk

2014-03-01

High performance limiters are described in this paper for applications in high frequency ultrasound imaging systems. Limiters protect the ultrasound receiver from the high voltage (HV) spikes produced by the transmitter. We present a new bipolar power transistor (BPT) configuration and compare its design and performance to a diode limiter used in traditional ultrasound research and one commercially available limiter. Limiter performance depends greatly on the insertion loss (IL), total harmonic distortion (THD) and response time (RT), each of which will be evaluated in all the limiters. The results indicated that, compared with commercial limiter, BPT-based limiter had less IL (-7.7 dB), THD (-74.6 dB) and lower RT (43 ns) at 100 MHz. To evaluate the capability of these limiters, they were connected to a 100 MHz single element transducer and a two-way pulse-echo test was performed. It was found that the -6 dB bandwidth and sensitivity of the transducer using BPT-based limiter were better than those of the commercial limiter by 22% and 140%, respectively. Compared to the commercial limiter, BPT-based limiter is shown to be capable of minimizing signal attenuation, RT and THD at high frequencies and is thus suited for high frequency ultrasound applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Forward-bias tunneling - A limitation to bipolar device scaling

NASA Technical Reports Server (NTRS)

Del Alamo, Jesus A.; Swanson, Richard M.

1986-01-01

Forward-bias tunneling is observed in heavily doped p-n junctions of bipolar transistors. A simple phenomenological model suitable to incorporation in device codes is developed. The model identifies as key parameters the space-charge-region (SCR) thickness at zero bias and the reduced doping level at its edges which can both be obtained from CV characteristics. This tunneling mechanism may limit the maximum gain achievable from scaled bipolar devices.

Static and dynamic behavior of a Si/Si0.8Ge0.2/Si heterojunction bipolar transistor using Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Galdin, Sylvie; Dollfus, Philippe; Hesto, Patrice

1994-03-01

A theoretical study of a Si/Si1-xGex/Si heterojunction bipolar transistor using Monte Carlo simulations is reported. The geometry and composition of the emitter-base junction are optimized using one-dimensional simulations with a view to improving electron transport in the base. It is proposed to introduce a thin Si-P spacer layer, between the Si-N emitter and the SiGe-P base, which allows launching hot electrons into the base despite the lack of natural conduction-band discontinuity between Si and strain SiGe. The high-frequency behavior of the complete transistor is then studied using 2D modeling. A method of microwave analysis using small signal Monte Carlo simulations that consists of expanding the terminal currents in Fourier series is presented. A cutoff frequency fT of 68 GHz has been extracted. Finally, the occurrence of a parasitic electron barrier at the collector-base junction is responsible for the fT fall-off at high collector current density. This parasitic barrier is lowered through the influence of the collector potential.

Characterization of Si (sub X)Ge (sub 1-x)/Si Heterostructures for Device Applications Using Spectroscopic Ellipsometry

NASA Technical Reports Server (NTRS)

Sieg, R. M.; Alterovitz, S. A.; Croke, E. T.; Harrell, M. J.; Tanner, M.; Wang, K. L.; Mena, R. A.; Young, P. G.

1993-01-01

Spectroscopic ellipsometry (SE) characterization of several complex Si (sub X)Ge (sub 1-x)/Si heterostructures prepared for device fabrication, including structures for heterojunction bipolar transistors (HBT), p-type and n-type heterostructure modulation doped field effect transistors, has been performed. We have shown that SE can simultaneously determine all active layer thicknesses, Si (sub X)Ge (sub 1-x) compositions, and the oxide overlayer thickness, with only a general knowledge of the structure topology needed a priori. The characterization of HBT material included the SE analysis of a Si (sub X)Ge (sub 1-x) layer deeply buried (600 nanometers) under the silicon emitter and cap layers. In the SE analysis of n-type heterostructures, we examined for the first time a silicon layer under tensile strain. We found that an excellent fit can be obtained using optical constants of unstrained silicon to represent the strained silicon conduction layer. We also used SE to measure lateral sample homogeneity, providing quantitative identification of the inhomogeneous layer. Surface overlayers resulting from prior sample processing were also detected and measured quantitatively. These results should allow SE to be used extensively as a non-destructive means of characterizing Si (sub X)Ge (sub 1-x)/Si heterostructures prior to device fabrication and testing.

Magnetic Vortex Based Transistor Operations

PubMed Central

Kumar, D.; Barman, S.; Barman, A.

2014-01-01

Transistors constitute the backbone of modern day electronics. Since their advent, researchers have been seeking ways to make smaller and more efficient transistors. Here, we demonstrate a sustained amplification of magnetic vortex core gyration in coupled two and three vortices by controlling their relative core polarities. This amplification is mediated by a cascade of antivortex solitons travelling through the dynamic stray field. We further demonstrated that the amplification can be controlled by switching the polarity of the middle vortex in a three vortex sequence and the gain can be controlled by the input signal amplitude. An attempt to show fan–out operation yielded gain for one of the symmetrically placed branches which can be reversed by switching the core polarity of all the vortices in the network. The above observations promote the magnetic vortices as suitable candidates to work as stable bipolar junction transistors (BJT). PMID:24531235

Magnetic vortex based transistor operations.

PubMed

Kumar, D; Barman, S; Barman, A

2014-02-17

Transistors constitute the backbone of modern day electronics. Since their advent, researchers have been seeking ways to make smaller and more efficient transistors. Here, we demonstrate a sustained amplification of magnetic vortex core gyration in coupled two and three vortices by controlling their relative core polarities. This amplification is mediated by a cascade of antivortex solitons travelling through the dynamic stray field. We further demonstrated that the amplification can be controlled by switching the polarity of the middle vortex in a three vortex sequence and the gain can be controlled by the input signal amplitude. An attempt to show fan-out operation yielded gain for one of the symmetrically placed branches which can be reversed by switching the core polarity of all the vortices in the network. The above observations promote the magnetic vortices as suitable candidates to work as stable bipolar junction transistors (BJT).

Magnetic Vortex Based Transistor Operations

NASA Astrophysics Data System (ADS)

Kumar, D.; Barman, S.; Barman, A.

2014-02-01

Transistors constitute the backbone of modern day electronics. Since their advent, researchers have been seeking ways to make smaller and more efficient transistors. Here, we demonstrate a sustained amplification of magnetic vortex core gyration in coupled two and three vortices by controlling their relative core polarities. This amplification is mediated by a cascade of antivortex solitons travelling through the dynamic stray field. We further demonstrated that the amplification can be controlled by switching the polarity of the middle vortex in a three vortex sequence and the gain can be controlled by the input signal amplitude. An attempt to show fan-out operation yielded gain for one of the symmetrically placed branches which can be reversed by switching the core polarity of all the vortices in the network. The above observations promote the magnetic vortices as suitable candidates to work as stable bipolar junction transistors (BJT).

Optically switched graphene/4H-SiC junction bipolar transistor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chandrashekhar, MVS; Sudarshan, Tangali S.; Omar, Sabih U.

A bi-polar device is provided, along with methods of making the same. The bi-polar device can include a semiconductor substrate doped with a first dopant, a semiconductor layer on the first surface of the semiconductor substrate, and a Schottky barrier layer on the semiconductor layer. The method of forming a bi-polar device can include: forming a semiconductor layer on a first surface of a semiconductor substrate, where the semiconductor substrate comprises a first dopant and where the semiconductor layer comprises a second dopant that has an opposite polarity than the first dopant; and forming a Schottky barrier layer on amore » first portion of the semiconductor layer while leaving a second portion of the semiconductor layer exposed.« less

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

NASA Astrophysics Data System (ADS)

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.

Hardness assurance testing and radiation hardening by design techniques for silicon-germanium heterojunction bipolar transistors and digital logic circuits

NASA Astrophysics Data System (ADS)

Sutton, Akil K.

Hydrocarbon exploration, global navigation satellite systems, computed tomography, and aircraft avionics are just a few examples of applications that require system operation at an ambient temperature, pressure, or radiation level outside the range covered by military specifications. The electronics employed in these applications are known as "extreme environment electronics." On account of the increased cost resulting from both process modifications and the use of exotic substrate materials, only a handful of semiconductor foundries have specialized in the production of extreme environment electronics. Protection of these electronic systems in an extreme environment may be attained by encapsulating sensitive circuits in a controlled environment, which provides isolation from the hostile ambient, often at a significant cost and performance penalty. In a significant departure from this traditional approach, system designers have begun to use commercial off-the-shelf technology platforms with built in mitigation techniques for extreme environment applications. Such an approach simultaneously leverages the state of the art in technology performance with significant savings in project cost. Silicon-germanium is one such commercial technology platform that demonstrates potential for deployment into extreme environment applications as a result of its excellent performance at cryogenic temperatures, remarkable tolerance to radiation-induced degradation, and monolithic integration with silicon-based manufacturing. In this dissertation the radiation response of silicon-germanium technology is investigated, and novel transistor-level layout-based techniques are implemented to improve the radiation tolerance of HBT digital logic.

High Accuracy Transistor Compact Model Calibrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hembree, Charles E.; Mar, Alan; Robertson, Perry J.

2015-09-01

Typically, transistors are modeled by the application of calibrated nominal and range models. These models consists of differing parameter values that describe the location and the upper and lower limits of a distribution of some transistor characteristic such as current capacity. Correspond- ingly, when using this approach, high degrees of accuracy of the transistor models are not expected since the set of models is a surrogate for a statistical description of the devices. The use of these types of models describes expected performances considering the extremes of process or transistor deviations. In contrast, circuits that have very stringent accuracy requirementsmore » require modeling techniques with higher accuracy. Since these accurate models have low error in transistor descriptions, these models can be used to describe part to part variations as well as an accurate description of a single circuit instance. Thus, models that meet these stipulations also enable the calculation of quantifi- cation of margins with respect to a functional threshold and uncertainties in these margins. Given this need, new model high accuracy calibration techniques for bipolar junction transis- tors have been developed and are described in this report.« less

Total Dose Effects on Bipolar Integrated Circuits at Low Temperature

NASA Technical Reports Server (NTRS)

Johnston, A. H.; Swimm, R. T.; Thorbourn, D. O.

2012-01-01

Total dose damage in bipolar integrated circuits is investigated at low temperature, along with the temperature dependence of the electrical parameters of internal transistors. Bandgap narrowing causes the gain of npn transistors to decrease far more at low temperature compared to pnp transistors, due to the large difference in emitter doping concentration. When irradiations are done at temperatures of -140 deg C, no damage occurs until devices are warmed to temperatures above -50 deg C. After warm-up, subsequent cooling shows that damage is then present at low temperature. This can be explained by the very strong temperature dependence of dispersive transport in the continuous-time-random-walk model for hole transport. For linear integrated circuits, low temperature operation is affected by the strong temperature dependence of npn transistors along with the higher sensitivity of lateral and substrate pnp transistors to radiation damage.

Recent Results on SEU Hardening of SiGe HBT Logic Circuits

NASA Technical Reports Server (NTRS)

Krithivasan, Ramkumar; Marshall, Paul W.; Nayeem, Mustayeen; Sutton, Akil K.; Kuo, Wei-Min Lance; Haugerud, Becca M.; Najafizadeh, Laieh; Cressler, John D.; Carts, martin A.; Marshall, Cheryl J.

2006-01-01

A viewgraph presentation on SEU tolerant SiGe HBT technology is shown. The topics include: 1) Introduction; 2) TID and SEU in SiGe Technology; 3) RHBD Techniques; 4) Experiment; 5) Heavy-Ion Data and Analysis; and 6) Summary.

Structured-gate organic field-effect transistors

NASA Astrophysics Data System (ADS)

Aljada, Muhsen; Pandey, Ajay K.; Velusamy, Marappan; Burn, Paul L.; Meredith, Paul; Namdas, Ebinazar B.

2012-06-01

We report the fabrication and electrical characteristics of structured-gate organic field-effect transistors consisting of a gate electrode patterned with three-dimensional pillars. The pillar gate electrode was over-coated with a gate dielectric (SiO2) and solution processed organic semiconductors producing both unipolar p-type and bipolar behaviour. We show that this new structured-gate architecture delivers higher source-drain currents, higher gate capacitance per unit equivalent linear channel area, and enhanced charge injection (electrons and/or holes) versus the conventional planar structure in all modes of operation. For the bipolar field-effect transistor (FET) the maximum source-drain current enhancements in p- and n-channel mode were >600% and 28%, respectively, leading to p and n charge mobilities with the same order of magnitude. Thus, we have demonstrated that it is possible to use the FET architecture to manipulate and match carrier mobilities of material combinations where one charge carrier is normally dominant. Mobility matching is advantageous for creating organic logic circuit elements such as inverters and amplifiers. Hence, the method represents a facile and generic strategy for improving the performance of standard organic semiconductors as well as new materials and blends.

Transferred substrate heterojunction bipolar transistors for submillimeter wave applications

NASA Technical Reports Server (NTRS)

Fung, A.; Samoska, L.; Siegel, P.; Rodwell, M.; Urteaga, M.; Paidi, V.

2003-01-01

We present ongoing work towards the development of submillimeter wave transistors with goals of realizing advanced high frequency amplifiers, voltage controlled oscillators, active multipliers, and traditional high-speed digital circuits.

Method and apparatus for increasing resistance of bipolar buried layer integrated circuit devices to single-event upsets

NASA Technical Reports Server (NTRS)

Zoutendyk, John A. (Inventor)

1991-01-01

Bipolar transistors fabricated in separate buried layers of an integrated circuit chip are electrically isolated with a built-in potential barrier established by doping the buried layer with a polarity opposite doping in the chip substrate. To increase the resistance of the bipolar transistors to single-event upsets due to ionized particle radiation, the substrate is biased relative to the buried layer with an external bias voltage selected to offset the built-in potential just enough (typically between about +0.1 to +0.2 volt) to prevent an accumulation of charge in the buried-layer-substrate junction.

Low-frequency switching in a transistor amplifier.

PubMed

Carroll, T L

2003-04-01

It is known from extensive work with the diode resonator that the nonlinear properties of a P-N junction can lead to period doubling, chaos, and other complicated behaviors in a driven circuit. There has been very little work on what happens when more than one P-N junction is present. In this work, the first step towards multiple P-N junction circuits is taken by doing both experiments and simulations with a single-transistor amplifier using a bipolar transistor. Period doubling and chaos are seen when the amplifier is driven with signals between 100 kHz and 1 MHz, and they coincide with a very low frequency switching between different period doubled (or chaotic) wave forms. The switching frequencies are between 5 and 10 Hz. The switching behavior was confirmed in a simplified model of the transistor amplifier.

High-Gain AlxGa1-xAs/GaAs Transistors For Neural Networks

NASA Technical Reports Server (NTRS)

Kim, Jae-Hoon; Lin, Steven H.

1991-01-01

High-gain AlxGa1-xAs/GaAs npn double heterojunction bipolar transistors developed for use as phototransistors in optoelectronic integrated circuits, especially in artificial neural networks. Transistors perform both photodetection and saturating-amplification functions of neurons. Good candidates for such application because structurally compatible with laser diodes and light-emitting diodes, detect light, and provide high current gain needed to compensate for losses in holographic optical elements.

Efficient Band-to-Trap Tunneling Model Including Heterojunction Band Offset

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Xujiao; Huang, Andy; Kerr, Bert

In this paper, we present an efficient band-to-trap tunneling model based on the Schenk approach, in which an analytic density-of-states (DOS) model is developed based on the open boundary scattering method. The new model explicitly includes the effect of heterojunction band offset, in addition to the well-known field effect. Its analytic form enables straightforward implementation into TCAD device simulators. It is applicable to all one-dimensional potentials, which can be approximated to a good degree such that the approximated potentials lead to piecewise analytic wave functions with open boundary conditions. The model allows for simulating both the electric-field-enhanced and band-offset-enhanced carriermore » recombination due to the band-to-trap tunneling near the heterojunction in a heterojunction bipolar transistor (HBT). Simulation results of an InGaP/GaAs/GaAs NPN HBT show that the proposed model predicts significantly increased base currents, due to the hole-to-trap tunneling enhanced by the emitter-base junction band offset. Finally, the results compare favorably with experimental observation.« less

Efficient Band-to-Trap Tunneling Model Including Heterojunction Band Offset

DOE PAGES

Gao, Xujiao; Huang, Andy; Kerr, Bert

2017-10-25

In this paper, we present an efficient band-to-trap tunneling model based on the Schenk approach, in which an analytic density-of-states (DOS) model is developed based on the open boundary scattering method. The new model explicitly includes the effect of heterojunction band offset, in addition to the well-known field effect. Its analytic form enables straightforward implementation into TCAD device simulators. It is applicable to all one-dimensional potentials, which can be approximated to a good degree such that the approximated potentials lead to piecewise analytic wave functions with open boundary conditions. The model allows for simulating both the electric-field-enhanced and band-offset-enhanced carriermore » recombination due to the band-to-trap tunneling near the heterojunction in a heterojunction bipolar transistor (HBT). Simulation results of an InGaP/GaAs/GaAs NPN HBT show that the proposed model predicts significantly increased base currents, due to the hole-to-trap tunneling enhanced by the emitter-base junction band offset. Finally, the results compare favorably with experimental observation.« less

Total Dose Effects on Single Event Transients in Digital CMOS and Linear Bipolar Circuits

NASA Technical Reports Server (NTRS)

Buchner, S.; McMorrow, D.; Sibley, M.; Eaton, P.; Mavis, D.; Dusseau, L.; Roche, N. J-H.; Bernard, M.

2009-01-01

This presentation discusses the effects of ionizing radiation on single event transients (SETs) in circuits. The exposure of integrated circuits to ionizing radiation changes electrical parameters. The total ionizing dose effect is observed in both complementary metal-oxide-semiconductor (CMOS) and bipolar circuits. In bipolar circuits, transistors exhibit grain degradation, while in CMOS circuits, transistors exhibit threshold voltage shifts. Changes in electrical parameters can cause changes in single event upset(SEU)/SET rates. Depending on the effect, the rates may increase or decrease. Therefore, measures taken for SEU/SET mitigation might work at the beginning of a mission but not at the end following TID exposure. The effect of TID on SET rates should be considered if SETs cannot be tolerated.

Extreme Temperature Performance of Automotive-Grade Small Signal Bipolar Junction Transistors

NASA Technical Reports Server (NTRS)

Boomer, Kristen; Damron, Benny; Gray, Josh; Hammoud, Ahmad

2018-01-01

Electronics designed for space exploration missions must display efficient and reliable operation under extreme temperature conditions. For example, lunar outposts, Mars rovers and landers, James Webb Space Telescope, Europa orbiter, and deep space probes represent examples of missions where extreme temperatures and thermal cycling are encountered. Switching transistors, small signal as well as power level devices, are widely used in electronic controllers, data instrumentation, and power management and distribution systems. Little is known, however, about their performance in extreme temperature environments beyond their specified operating range; in particular under cryogenic conditions. This report summarizes preliminary results obtained on the evaluation of commercial-off-the-shelf (COTS) automotive-grade NPN small signal transistors over a wide temperature range and thermal cycling. The investigations were carried out to establish a baseline on functionality of these transistors and to determine suitability for use outside their recommended temperature limits.

The Effect of Strain on the Base Resistance and Transit Time of Ungraded and Compositional-Graded SiGe HBTs

NASA Technical Reports Server (NTRS)

Rosenfeld, D.; Alterovitz, S. A.

1994-01-01

A theoretical study of the effects of the strain on the base properties of ungraded and compositional-graded n-p-n SiGe Heterojunction Bipolar Transistors (HBT) is presented. The dependencies of the transverse hole mobility and longitudinal electron mobility upon strain, composition and doping, are formulated using published Monte-Carlo data and, consequently, the base resistance and transit time are modeled and calculated. The results are compared to results obtained using common formulas that ignore these dependencies. The differences between the two sets of results are shown. The paper's conclusion is that for the design, analysis and optimization of high frequency SiGe HBTs the strain effects on the base properties cannot be ignored.

High-performance silicon nanowire bipolar phototransistors

NASA Astrophysics Data System (ADS)

Tan, Siew Li; Zhao, Xingyan; Chen, Kaixiang; Crozier, Kenneth B.; Dan, Yaping

2016-07-01

Silicon nanowires (SiNWs) have emerged as sensitive absorbing materials for photodetection at wavelengths ranging from ultraviolet (UV) to the near infrared. Most of the reports on SiNW photodetectors are based on photoconductor, photodiode, or field-effect transistor device structures. These SiNW devices each have their own advantages and trade-offs in optical gain, response time, operating voltage, and dark current noise. Here, we report on the experimental realization of single SiNW bipolar phototransistors on silicon-on-insulator substrates. Our SiNW devices are based on bipolar transistor structures with an optically injected base region and are fabricated using CMOS-compatible processes. The experimentally measured optoelectronic characteristics of the SiNW phototransistors are in good agreement with simulation results. The SiNW phototransistors exhibit significantly enhanced response to UV and visible light, compared with typical Si p-i-n photodiodes. The near infrared responsivities of the SiNW phototransistors are comparable to those of Si avalanche photodiodes but are achieved at much lower operating voltages. Compared with other reported SiNW photodetectors as well as conventional bulk Si photodiodes and phototransistors, the SiNW phototransistors in this work demonstrate the combined advantages of high gain, high photoresponse, low dark current, and low operating voltage.

High ESD Breakdown-Voltage InP HBT Transimpedance Amplifier IC for Optical Video Distribution Systems

NASA Astrophysics Data System (ADS)

Sano, Kimikazu; Nagatani, Munehiko; Mutoh, Miwa; Murata, Koichi

This paper is a report on a high ESD breakdown-voltage InP HBT transimpedance amplifier IC for optical video distribution systems. To make ESD breakdown-voltage higher, we designed ESD protection circuits integrated in the TIA IC using base-collector/base-emitter diodes of InP HBTs and resistors. These components for ESD protection circuits have already existed in the employed InP HBT IC process, so no process modifications were needed. Furthermore, to meet requirements for use in optical video distribution systems, we studied circuit design techniques to obtain a good input-output linearity and a low-noise characteristic. Fabricated InP HBT TIA IC exhibited high human-body-model ESD breakdown voltages (±1000V for power supply terminals, ±200V for high-speed input/output terminals), good input-output linearity (less than 2.9-% duty-cycle-distortion), and low noise characteristic (10.7pA/√Hz averaged input-referred noise current density) with a -3-dB-down higher frequency of 6.9GHz. To the best of our knowledge, this paper is the first literature describing InP ICs with high ESD-breakdown voltages.

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

NASA Technical Reports Server (NTRS)

Ma, Zhenqiang; Jiang, Ningyue; Ponchak, George E.; Alterovitz, Samuel A.

2005-01-01

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

Outlook and emerging semiconducting materials for ambipolar transistors.

PubMed

Bisri, Satria Zulkarnaen; Piliego, Claudia; Gao, Jia; Loi, Maria Antonietta

2014-02-26

Ambipolar or bipolar transistors are transistors in which both holes and electrons are mobile inside the conducting channel. This device allows switching among several states: the hole-dominated on-state, the off-state, and the electron-dominated on-state. In the past year, it has attracted great interest in exotic semiconductors, such as organic semiconductors, nanostructured materials, and carbon nanotubes. The ability to utilize both holes and electrons inside one device opens new possibilities for the development of more compact complementary metal-oxide semiconductor (CMOS) circuits, and new kinds of optoelectronic device, namely, ambipolar light-emitting transistors. This progress report highlights the recent progresses in the field of ambipolar transistors, both from the fundamental physics and application viewpoints. Attention is devoted to the challenges that should be faced for the realization of ambipolar transistors with different material systems, beginning with the understanding of the importance of interface modification, which heavily affects injections and trapping of both holes and electrons. The recent development of advanced gating applications, including ionic liquid gating, that open up more possibility to realize ambipolar transport in materials in which one type of charge carrier is highly dominant is highlighted. Between the possible applications of ambipolar field-effect transistors, we focus on ambipolar light-emitting transistors. We put this new device in the framework of its prospective for general lightings, embedded displays, current-driven laser, as well as for photonics-electronics interconnection. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nonlinear System Analysis in Bipolar Integrated Circuits.

DTIC Science & Technology

1980-01-01

H2 (fl,f 6), H2 (f2,f4), and H2 (f3,f4) are all equal, Equation (7-8) can be written as v M(t) = mA2 H2 (fl’-f 2) cos[27(f ,-f2)t] (7-9) The AF...and R. A. AMADORI: Micro- wave Interference Effect in Bipolar Transistors, IEEE Trans. EMC, Vol. EMC-17, pp. 216-219, November 1975. 55. KAPLAN , G

Development of ion implanted gallium arsenide transistors

NASA Technical Reports Server (NTRS)

Hunsperger, R.; Baron, R.

1972-01-01

Techniques were developed for creating bipolar microwave transistors in GaAs by ion implantation doping. The electrical properties of doped layers produced by the implantation of the light ions Be, Mg, and S were studied. Be, Mg, and S are suitable for forming the relatively deep base-collector junction at low ion energies. The electrical characteristics of ion-implanted diodes of both the mesa and planar types were determined. Some n-p-n planar transistor structures were fabricated by implantation of Mg to form the base regions and Si to form the emitters. These devices were found to have reasonably good base-collector and emitter-base junctions, but the current gain beta was small. The low was attributable to radiative recombination in the base region, which was extremely wide.

Specifics of Pulsed Arc Welding Power Supply Performance Based On A Transistor Switch

NASA Astrophysics Data System (ADS)

Krampit, N. Yu; Kust, T. S.; Krampit, M. A.

2016-08-01

Specifics of designing a pulsed arc welding power supply device are presented in the paper. Electronic components for managing large current was analyzed. Strengths and shortcomings of power supply circuits based on thyristor, bipolar transistor and MOSFET are outlined. As a base unit for pulsed arc welding was chosen MOSFET transistor, which is easy to manage. Measures to protect a transistor are given. As for the transistor control device is a microcontroller Arduino which has a low cost and adequate performance of the work. Bead transfer principle is to change the voltage on the arc in the formation of beads on the wire end. Microcontroller controls transistor when the arc voltage reaches the threshold voltage. Thus there is a separation and transfer of beads without splashing. Control strategies tested on a real device and presented. The error in the operation of the device is less than 25 us, it can be used controlling drop transfer at high frequencies (up to 1300 Hz).

A Physics-Based Engineering Methodology for Calculating Soft Error Rates of Bulk CMOS and SiGe Heterojunction Bipolar Transistor Integrated Circuits

NASA Astrophysics Data System (ADS)

Fulkerson, David E.

2010-02-01

This paper describes a new methodology for characterizing the electrical behavior and soft error rate (SER) of CMOS and SiGe HBT integrated circuits that are struck by ions. A typical engineering design problem is to calculate the SER of a critical path that commonly includes several circuits such as an input buffer, several logic gates, logic storage, clock tree circuitry, and an output buffer. Using multiple 3D TCAD simulations to solve this problem is too costly and time-consuming for general engineering use. The new and simple methodology handles the problem with ease by simple SPICE simulations. The methodology accurately predicts the measured threshold linear energy transfer (LET) of a bulk CMOS SRAM. It solves for circuit currents and voltage spikes that are close to those predicted by expensive 3D TCAD simulations. It accurately predicts the measured event cross-section vs. LET curve of an experimental SiGe HBT flip-flop. The experimental cross section vs. frequency behavior and other subtle effects are also accurately predicted.

Energy dependence of proton displacement damage factors for bipolar transistors

NASA Astrophysics Data System (ADS)

Summers, Geoffrey P.; Xapsos, Michael A.; Dale, Cheryl J.; Wolicki, Eligius A.; Marshall, Paul

1986-12-01

Displacement damage factors, K(p), have been measured as a function of collector current for proton irradiations of 2N2222A (npn) and 2N2907A (pnp) switching transistors and 2N3055 (npn) power transistors over the energy range 5.0 to 60.3 MeV. The measurements of K(p) were made on specially selected lots of devices and were compared to values of the neutron damage factors, K(n), for 1-MeV displacement damage equivalent neutrons made on the same devices. The results show that, so far as device operation is concerned, the nature of the displacement damage produced by high energy protons and by fission neutrons is essentially the same. Over the energy range studied, protons were found to be more damaging than neutrons. For 5.0 MeV protons Kp/Kn was about 8.5 compared to about 1.8 for 60.3 MeV protons.

A bipolar analog front-end integrated circuit for the SDC silicon tracker

NASA Astrophysics Data System (ADS)

Kipnis, I.; Spieler, H.; Collins, T.

1993-11-01

A low noise, low power, high bandwidth, radiation hard, silicon bipolar transistor full-custom integrated circuit (IC) containing 64 channels of analog signal processing has been developed for the SDC silicon tracker. The IC was designed and tested at LBL and was fabricated using CBIC-U2, 4 GHz f(sub T) complementary bipolar technology. Each channel contains the following functions: low noise preamplification, pulse shaping, and threshold discrimination. This is the first iteration of the production analog IC for the SDC silicon tracker. The IC is laid out to directly match the 50 micron pitch double-sided silicon strip detector. The chip measures 6.8 mm by 3.1 mm and contains 3,600 transistors. Three stages of amplification provide 180 mV/fC of gain with a 35 nsec peaking time at the comparator input. For a 14 pF detector capacitance, the equivalent noise charge is 1300 el. rms at a power consumption of 1 mW/channel from a single 3.5 V supply. With the discriminator threshold set to four times the noise level, a 16 nsec time-walk for 1.25 to 10 fC signals is achieved using a time-walk compensation network. Irradiation tests at TRIUMF to a Phi = 10(exp 14) protons/sq cm have been performed on the IC, demonstrating the radiation hardness of the complementary bipolar process.

Carbon incorporation in InP grown by metalorganic chemical vapor deposition and application to InP/InGaAs heterojunction bipolar transistors

NASA Astrophysics Data System (ADS)

Stockman, S. A.; Fresina, M. T.; Hartmann, Q. J.; Hanson, A. W.; Gardner, N. F.; Baker, J. E.; Stillman, G. E.

1994-04-01

The incorporation of residual carbon has been studied for InP grown at low temperatures using TMIn and PH3 by low-pressure metalorganic chemical vapor deposition. n-type conduction is observed with electron concentrations as high as 1×1018 cm-3, and the electrical activation efficiency is 5%-15%. Carbon incorporation is found to be highly dependent on substrate temperature, suggesting that the rate-limiting step is desorption of CHy (0≤y≤3) from the surface during growth. Hydrogen is also incorporated in the layers during growth. The electron mobilities are lower for C-doped InP than for Si-doped InP. InP/InGaAs heterojunction bipolar transistors with C as the p-type base dopant and either Si or C as the n-type emitter dopant have been fabricated and compared. Devices with a carbon-doped base and emitter showed degraded performance, likely as a result of deep levels incorporated during growth of the emitter.

On the AlGaInP-bulk and AlGaInP/GaAs-superlattice confinement effects for heterostructure-emitter bipolar transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, Jung-Hui, E-mail: jhtsai@nknucc.nknu.edu.tw

2015-02-09

The confinement effect and electrical characteristics of heterostructure-emitter bipolar transistors with an AlGaInP bulk-confinement layer and an AlGaInP/GaAs superlattice-confinement layer are first demonstrated and compared by experimentally results. In the two devices, the relatively large valence band discontinuity at AlGaInP/GaAs heterojunction provides excellent confinement effect for holes to enhance current gain. As to the AlGaInP/GaAs superlattice-confinement device, part of thermionic-emission electrons will be trapped in the GaAs quantum wells of the superlattice. This will result in lower collector current and current gain as compared with the bulk-confinement device. Nevertheless, the superlattice-confinement device exhibits a larger current-gain cutoff frequency, which canmore » be attributed that the tunneling behavior is included in the carrier transportation and transporting time across the emitter region could be substantially reduced.« less

Graphene base heterojunction transistor: An explorative study on device potential, optimization, and base parasitics

NASA Astrophysics Data System (ADS)

Di Lecce, Valerio; Grassi, Roberto; Gnudi, Antonio; Gnani, Elena; Reggiani, Susanna; Baccarani, Giorgio

2015-12-01

The Graphene-Base Heterojunction Transistor (GBHT) is a novel device concept with a high potential for analog high-frequency RF operation, in which the current is due to both thermionic emission and tunneling. In this paper we study through numerical simulations the influence of previously uninvestigated aspects of Si- and Ge-based GBHTs-namely, crystallographic orientation and doping density values-on the device performance; a comparison with an aggressively scaled HBT structure is then reported. The simulations are carried out with an in-house developed code based on a 1-D quantum transport model within the effective mass approximation and the assumptions of ballistic transport with non-parabolic corrections and ideal semiconductor-graphene interface. We show that crystallographic orientation has a negligible effect on the GBHT performance. The doping density values in the GBHT emitter and collector regions can be tailored to maximize the device performance: the Si device shows better overall performance than the Ge one, yielding a peak cut-off frequency fT higher than 4 THz together with an intrinsic voltage gain above 10, or even higher fT at the cost of a lower gain. The Si-based GBHT can potentially outperform the SiGe HBT by a 2.8 higher fT . For a Si-based GBHT with a circular active region of diameter 50-100 nm, a theoretical balanced value for fT and fmax above 2 THz can be achieved, provided the base parasitics are carefully minimized.

An ion-gated bipolar amplifier for ion sensing with enhanced signal and improved noise performance

NASA Astrophysics Data System (ADS)

Zhang, Da; Gao, Xindong; Chen, Si; Norström, Hans; Smith, Ulf; Solomon, Paul; Zhang, Shi-Li; Zhang, Zhen

2014-08-01

This work presents a proof-of-concept ion-sensitive device operating in electrolytes. The device, i.e., an ion-gated bipolar amplifier (IGBA), consists of a modified ion-sensitive field-effect transistor (ISFET) intimately integrated with a vertical bipolar junction transistor for immediate current amplification without introducing additional noise. With the current non-optimized design, the IGBA is already characterized by a 70-fold internal amplification of the ISFET output signal. This signal amplification is retained when the IGBA is used for monitoring pH variations. The tight integration significantly suppresses the interference of the IGBA signal by external noise, which leads to an improvement in signal-to-noise performance compared to its ISFET reference. The IGBA concept is especially suitable for biochips with millions of electric sensors that are connected to peripheral readout circuitry via extensive metallization which may in turn invite external interferences leading to contamination of the signal before it reaches the first external amplification stage.

Electroluminescence from single-wall carbon nanotube network transistors.

PubMed

Adam, E; Aguirre, C M; Marty, L; St-Antoine, B C; Meunier, F; Desjardins, P; Ménard, D; Martel, R

2008-08-01

The electroluminescence (EL) properties from single-wall carbon nanotube network field-effect transistors (NNFETs) and small bundle carbon nanotube field effect transistors (CNFETs) are studied using spectroscopy and imaging in the near-infrared (NIR). At room temperature, NNFETs produce broad (approximately 180 meV) and structured NIR spectra, while they are narrower (approximately 80 meV) for CNFETs. EL emission from NNFETs is located in the vicinity of the minority carrier injecting contact (drain) and the spectrum of the emission is red shifted with respect to the corresponding absorption spectrum. A phenomenological model based on a Fermi-Dirac distribution of carriers in the nanotube network reproduces the spectral features observed. This work supports bipolar (electron-hole) current recombination as the main mechanism of emission and highlights the drastic influence of carrier distribution on the optoelectronic properties of carbon nanotube films.

Mass Dependence of the HBT Radii Observed in e+e- Annihilation

NASA Astrophysics Data System (ADS)

Bialas, A.; Zalewski, K.

1999-02-01

It is shown that the recently established strong mass-dependence of the radii of the hadron sources, as observed in HBT analyses of the e+e- annihilation, can be explained by assuming a generalized inside--outside cascade, i.e. that (i) the four-momenta and the space-time position four-vectors of the produced particles are approximately proportional to each other and (ii) the ``freeze-out'' times are distributed along the hyperbola t2-z2= τ02.

A 65-kV insulated gate bipolar transistor switch applied in damped AC voltages partial discharge detection system.

PubMed

Jiang, J; Ma, G M; Luo, D P; Li, C R; Li, Q M; Wang, W

2014-02-01

Damped AC voltages detection system (DAC) is a productive way to detect the faults in power cables. To solve the problems of large volume, complicated structure and electromagnetic interference in existing switches, this paper developed a compact solid state switch based on electromagnetic trigger, which is suitable for DAC test system. Synchronous electromagnetic trigger of 32 Insulated Gate Bipolar Transistors (IGBTs) in series was realized by the topological structure of single line based on pulse width modulation control technology. In this way, external extension was easily achieved. Electromagnetic trigger and resistor-capacitor-diode snubber circuit were optimized to reduce the switch turn-on time and circular layout. Epoxy encapsulating was chosen to enhance the level of partial discharge initial voltage (PDIV). The combination of synchronous trigger and power supply is proposed to reduce the switch volume. Moreover, we have overcome the drawback of the electromagnetic interference and improved the detection sensitivity of DAC by using capacitor storage energy to maintain IGBT gate driving voltage. The experimental results demonstrated that the solid-state switch, with compact size, whose turn-on time was less than 400 ns and PDIV was more than 65 kV, was able to meet the actual demands of 35 kV DAC test system.

A pattern recognition approach to transistor array parameter variance

NASA Astrophysics Data System (ADS)

da F. Costa, Luciano; Silva, Filipi N.; Comin, Cesar H.

2018-06-01

The properties of semiconductor devices, including bipolar junction transistors (BJTs), are known to vary substantially in terms of their parameters. In this work, an experimental approach, including pattern recognition concepts and methods such as principal component analysis (PCA) and linear discriminant analysis (LDA), was used to experimentally investigate the variation among BJTs belonging to integrated circuits known as transistor arrays. It was shown that a good deal of the devices variance can be captured using only two PCA axes. It was also verified that, though substantially small variation of parameters is observed for BJT from the same array, larger variation arises between BJTs from distinct arrays, suggesting the consideration of device characteristics in more critical analog designs. As a consequence of its supervised nature, LDA was able to provide a substantial separation of the BJT into clusters, corresponding to each transistor array. In addition, the LDA mapping into two dimensions revealed a clear relationship between the considered measurements. Interestingly, a specific mapping suggested by the PCA, involving the total harmonic distortion variation expressed in terms of the average voltage gain, yielded an even better separation between the transistor array clusters. All in all, this work yielded interesting results from both semiconductor engineering and pattern recognition perspectives.

Ambipolar nonvolatile memory based on a quantum-dot transistor with a nanoscale floating gate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Che, Yongli; Zhang, Yating, E-mail: yating@tju.edu.cn; Song, Xiaoxian

2016-07-04

Using only solution processing methods, we developed ambipolar quantum-dot (QD) transistor floating-gate memory (FGM) that uses Au nanoparticles as a floating gate. Because of the bipolarity of the active channel of PbSe QDs, the memory could easily trap holes or electrons in the floating gate by programming/erasing (P/E) operations, which could shift the threshold voltage both up and down. As a result, the memory exhibited good programmable memory characteristics: a large memory window (ΔV{sub th} ∼ 15 V) and a long retention time (>10{sup 5 }s). The magnitude of ΔV{sub th} depended on both P/E voltages and the bias voltage (V{sub DS}): ΔV{sub th}more » was a cubic function to V{sub P/E} and linearly depended on V{sub DS}. Therefore, this FGM based on a QD transistor is a promising alternative to its inorganic counterparts owing to its advantages of bipolarity, high mobility, low cost, and large-area production.« less

Extreme ultraviolet diagnostic upgrades for kink mode control on the HBT-EP tokamak

NASA Astrophysics Data System (ADS)

Levesque, J. P.; Brooks, J. W.; Desanto, S.; Mauel, M. E.; Navratil, G. A.; Page, J. W.; Hansen, C. J.; Delgado-Aparicio, L.

2016-10-01

Optical diagnostics can provide non-invasive measurements of tokamak equilibria and the internal characteristics of MHD mode activity. We present research plans and ongoing progress on upgrading extreme ultraviolet (EUV) diagnostics in the HBT-EP tokamak. Four sets of 16 poloidal views will allow tomographic reconstruction of plasma emissivity and internal kink mode structure. Emission characteristics of naturally-occurring m/n = 2/1, 3/2, and 3/1 tearing and kink modes will be compared with expectations from a synthetic diagnostic. Coupling between internal and external modes leading up to disruptions is studied. The internal plasma response to external magnetic perturbations is investigated, and compared with magnetic response measurements. Correlation between internal emissivity and external magnetic measurements provides a global picture of long-wavelength MHD instabilities. Measurements are input to HBT-EP's GPU-based feedback system, allowing active feedback for kink modes using only optical sensors and both magnetic and edge current actuators. A separate two-color, 16-chord tangential system will be installed next year to allow reconstruction of temperature profiles and their fluctuations versus time. Supported by U.S. DOE Grant DE-FG02-86ER53222.

Design of a High-Speed and Compact Electro-Optic Modulator using Silicon-Germanium HBT

NASA Astrophysics Data System (ADS)

Neogi, Tuhin Guha

Optical interconnects between electronics systems have attracted significant attention and development for a number of years because optical links have demonstrated potential advantages for high-speed, low-power, and interference immunity. With increasing system speed and greater bandwidth requirements, the distance over which optical communication is useful has continually decreased to chip-to-chip and on-chip levels. Monolithic integration of photonics and electronics will significantly reduce the cost of optical components and further combine the functionalities of chips on the same or different boards or systems. Modulators are one of the fundamental building blocks for optical interconnects. High-speed modulation and low driving voltage are the keys for the device's practical use. In this study two separate designs show that using a graded base SiGe HBT we can modulate light at high speeds with moderate length and dynamic power consumption. The first design analyzes the terminal characteristics of the HBT and a close match is obtained in comparison with npn HBTs using IBM.s 8HP technology. This suggests that the modulator can be manufactured using the IBM 8HP fabrication process. At a sub-collector depth of 0.4 mum and at a base-emitter swing of 0 V to 1.1 V, this model predicts a bit rate of 80 Gbit/s. Optical simulations predict a pi phase shift length (Lpi) of 240.8 mum with an extinction ratio of 7.5 dB at a wavelength of 1.55 mum. Additionally, the trade-off between the switching speed, Lpi and propagation loss with a thinner sub-collector is analyzed and reported. The dynamic power consumption is reported to be 3.6 pJ /bit. The second design examine a theoretical aggressively-scaled SiGe HBT that may approximate a device that is two device generations more advanced than available today. At a base-emitter swing of 0 V to 1.0 V, this model predicts a bit rate of 250 Gbit/s. Optical simulations predict a pi phase shift length (Lpi) of 204 mum, with an

Physical meaning of two-particle HBT measurements in case of correlated emission

NASA Astrophysics Data System (ADS)

Bialas, A.; Zalewski, K.

2004-07-01

It is shown that, in the presence of correlations in particle emission, the measured HBT radii are related to the correlation range rather than to the size of the interaction volume. Only in the case of weak correlations the standard interpretation may be applicable. The earlier discussion [Phys. Rev. Lett. 68 (1992) 1109; Phys. Rev. C 49 (1994) 2722] of the short-range correlations in configuration space is generalized to include also the correlations of particle momenta.

A dc model for power switching transistors suitable for computer-aided design and analysis

NASA Technical Reports Server (NTRS)

Wilson, P. M.; George, R. T., Jr.; Owen, H. A., Jr.; Wilson, T. G.

1979-01-01

The proposed dc model for bipolar junction power switching transistors is based on measurements which may be made with standard laboratory equipment. Those nonlinearities which are of importance to power electronics design are emphasized. Measurements procedures are discussed in detail. A model formulation adapted for use with a computer program is presented, and a comparison between actual and computer-generated results is made.

A dc model for power switching transistors suitable for computer-aided design and analysis

NASA Technical Reports Server (NTRS)

Wilson, P. M.; George, R. T., Jr.; Owen, H. A.; Wilson, T. G.

1979-01-01

A model for bipolar junction power switching transistors whose parameters can be readily obtained by the circuit design engineer, and which can be conveniently incorporated into standard computer-based circuit analysis programs is presented. This formulation results from measurements which may be made with standard laboratory equipment. Measurement procedures, as well as a comparison between actual and computed results, are presented.

Long-Term Reliability of SiGe/Si HBTs From Accelerated Lifetime Testing

NASA Technical Reports Server (NTRS)

Bhattacharya, Pallab

2001-01-01

Accelerated lifetime tests were performed on double-mesa structure Si(0.7)Ge(0.3)/Si npn heterojunction bipolar transistors, grown by molecular beam epitaxy, in the temperature range of 175 C-275 C. The transistors (with 5x20 sq micron emitter area) have DC current gains approx. 40-50 and f(sub T) and f(sub max) of up to 22 GHz and 25 GHz, respectively. It is found that a gradual degradation in these devices is caused by the recombination enhanced impurity diffusion (REID) of boron atoms from the p-type base region and the associated formation of parasitic energy barriers to electron transport from the emitter to collector layers. This REED has been quantitatively modeled and explained, to the first order of approximation, and the agreement with the measured data is good. The mean time to failure (MTTF) of these devices at room temperature under 1.35 x 10(exp 4) A/sq cm current density operation is estimated from the extrapolation of the Arrhenius plots of device lifetime versus reciprocal temperature. The results of the reliability tests offer valuable feedback for SiGe heterostructure design in order to improve the long-term reliability of the devices and circuits made with them. Hot electron induced degradation of the base-emitter junction was also observed during the accelerated lifetime testing. In order to improve the HBT reliability endangered by the hot electrons, deuterium sintered techniques have been proposed. The preliminary results from this study show that a deuterium-sintered HBT is, indeed, more resistant to hot-electron induced base-emitter junction degradation.

Optimization of Vertical Double-Diffused Metal-Oxide Semiconductor (VDMOS) Power Transistor Structure for Use in High Frequencies and Medical Devices

PubMed Central

Farhadi, Rozita; Farhadi, Bita

2014-01-01

Power transistors, such as the vertical, double-diffused, metal-oxide semiconductor (VDMOS), are used extensively in the amplifier circuits of medical devices. The aim of this research was to construct a VDMOS power transistor with an optimized structure to enhance the operation of medical devices. First, boron was implanted in silicon by implanting unclamped inductive switching (UIS) and a Faraday shield. The Faraday shield was implanted in order to replace the gate-field parasitic capacitor on the entry part of the device. Also, implanting the UIS was used in order to decrease the effect of parasitic bipolar junction transistor (BJT) of the VDMOS power transistor. The research tool used in this study was Silvaco software. By decreasing the transistor entry resistance in the optimized VDMOS structure, power losses and noise at the entry of the transistor were decreased, and, by increasing the breakdown voltage, the lifetime of the VDMOS transistor lifetime was increased, which resulted in increasing drain flow and decreasing Ron. This consequently resulted in enhancing the operation of high-frequency medical devices that use transistors, such as Radio Frequency (RF) and electrocardiograph machines. PMID:25763152

Optimization of Vertical Double-Diffused Metal-Oxide Semiconductor (VDMOS) Power Transistor Structure for Use in High Frequencies and Medical Devices.

PubMed

Farhadi, Rozita; Farhadi, Bita

2014-01-01

Power transistors, such as the vertical, double-diffused, metal-oxide semiconductor (VDMOS), are used extensively in the amplifier circuits of medical devices. The aim of this research was to construct a VDMOS power transistor with an optimized structure to enhance the operation of medical devices. First, boron was implanted in silicon by implanting unclamped inductive switching (UIS) and a Faraday shield. The Faraday shield was implanted in order to replace the gate-field parasitic capacitor on the entry part of the device. Also, implanting the UIS was used in order to decrease the effect of parasitic bipolar junction transistor (BJT) of the VDMOS power transistor. The research tool used in this study was Silvaco software. By decreasing the transistor entry resistance in the optimized VDMOS structure, power losses and noise at the entry of the transistor were decreased, and, by increasing the breakdown voltage, the lifetime of the VDMOS transistor lifetime was increased, which resulted in increasing drain flow and decreasing Ron. This consequently resulted in enhancing the operation of high-frequency medical devices that use transistors, such as Radio Frequency (RF) and electrocardiograph machines.

Memristive device based on a depletion-type SONOS field effect transistor

NASA Astrophysics Data System (ADS)

Himmel, N.; Ziegler, M.; Mähne, H.; Thiem, S.; Winterfeld, H.; Kohlstedt, H.

2017-06-01

State-of-the-art SONOS (silicon-oxide-nitride-oxide-polysilicon) field effect transistors were operated in a memristive switching mode. The circuit design is a variation of the MemFlash concept and the particular properties of depletion type SONOS-transistors were taken into account. The transistor was externally wired with a resistively shunted pn-diode. Experimental current-voltage curves show analog bipolar switching characteristics within a bias voltage range of ±10 V, exhibiting a pronounced asymmetric hysteresis loop. The experimental data are confirmed by SPICE simulations. The underlying memristive mechanism is purely electronic, which eliminates an initial forming step of the as-fabricated cells. This fact, together with reasonable design flexibility, in particular to adjust the maximum R ON/R OFF ratio, makes these cells attractive for neuromorphic applications. The relative large set and reset voltage around ±10 V might be decreased by using thinner gate-oxides. The all-electric operation principle, in combination with an established silicon manufacturing process of SONOS devices at the Semiconductor Foundry X-FAB, promise reliable operation, low parameter spread and high integration density.

Initial Ferritic Wall Mode studies on HBT-EP

NASA Astrophysics Data System (ADS)

Hughes, Paul; Bialek, J.; Boozer, A.; Mauel, M. E.; Levesque, J. P.; Navratil, G. A.

2013-10-01

Low-activation ferritic steels are leading material candidates for use in next-generation fusion development experiments such as a prospective US component test facility and DEMO. Understanding the interaction of plasmas with a ferromagnetic wall will provide crucial physics for these experiments. Although the ferritic wall mode (FWM) was seen in a linear machine, the FWM was not observed in JFT-2M, probably due to eddy current stabilization. Using its high-resolution magnetic diagnostics and positionable walls, HBT-EP has begun exploring the dynamics and stability of plasma interacting with high-permeability ferritic materials tiled to reduce eddy currents. We summarize a simple model for plasma-wall interaction in the presence of ferromagnetic material, describe the design of a recently-installed set of ferritic shell segments, and report initial results. Supported by U.S. DOE Grant DE-FG02-86ER53222.

MMIC DHBT Common-Base Amplifier for 172 GHz

NASA Technical Reports Server (NTRS)

Paidi, Vamsi; Griffith, Zack; Wei, Yun; Dahlstrom, Mttias; Urteaga, Miguel; Rodwell, Mark; Samoska, Lorene; Fung, King Man; Schlecht, Erich

2006-01-01

Figure 1 shows a single-stage monolithic microwave integrated circuit (MMIC) power amplifier in which the gain element is a double-heterojunction bipolar transistor (DHBT) connected in common-base configuration. This amplifier, which has been demonstrated to function well at a frequency of 172 GHz, is part of a continuing effort to develop compact, efficient amplifiers for scientific instrumentation, wide-band communication systems, and radar systems that will operate at frequencies up to and beyond 180 GHz. The transistor is fabricated from a layered structure formed by molecular beam epitaxy in the InP/InGaAs material system. A highly doped InGaAs base layer and a collector layer are fabricated from the layered structure in a triple mesa process. The transistor includes two separate emitter fingers, each having dimensions of 0.8 by 12 m. The common-base configuration was chosen for its high maximum stable gain in the frequency band of interest. The input-matching network is designed for high bandwidth. The output of the transistor is matched to a load line for maximum saturated output power under large-signal conditions, rather than being matched for maximum gain under small-signal conditions. In a test at a frequency of 172 GHz, the amplifier was found to generate an output power of 7.5 mW, with approximately 5 dB of large-signal gain (see Figure 2). Moreover, the amplifier exhibited a peak small-signal gain of 7 dB at a frequency of 176 GHz. This performance of this MMIC single-stage amplifier containing only a single transistor represents a significant advance in the state of the art, in that it rivals the 170-GHz performance of a prior MMIC three-stage, four-transistor amplifier. [The prior amplifier was reported in "MMIC HEMT Power Amplifier for 140 to 170 GHz" (NPO-30127), NASA Tech Briefs, Vol. 27, No. 11 (November 2003), page 49.] This amplifier is the first heterojunction- bipolar-transistor (HBT) amplifier built for medium power operation in this

Gigascale Silicon Photonic Transmitters Integrating HBT-based Carrier-injection Electroabsorption Modulator Structures

NASA Astrophysics Data System (ADS)

Fu, Enjin

Demand for more bandwidth is rapidly increasing, which is driven by data intensive applications such as high-definition (HD) video streaming, cloud storage, and terascale computing applications. Next-generation high-performance computing systems require power efficient chip-to-chip and intra-chip interconnect yielding densities on the order of 1Tbps/cm2. The performance requirements of such system are the driving force behind the development of silicon integrated optical interconnect, providing a cost-effective solution for fully integrated optical interconnect systems on a single substrate. Compared to conventional electrical interconnect, optical interconnects have several advantages, including frequency independent insertion loss resulting in ultra wide bandwidth and link latency reduction. For high-speed optical transmitter modules, the optical modulator is a key component of the optical I/O channel. This thesis presents a silicon integrated optical transmitter module design based on a novel silicon HBT-based carrier injection electroabsorption modulator (EAM), which has the merits of wide optical bandwidth, high speed, low power, low drive voltage, small footprint, and high modulation efficiency. The structure, mechanism, and fabrication of the modulator structure will be discussed which is followed by the electrical modeling of the post-processed modulator device. The design and realization of a 10Gbps monolithic optical transmitter module integrating the driver circuit architecture and the HBT-based EAM device in a 130nm BiCMOS process is discussed. For high power efficiency, a 6Gbps ultra-low power driver IC implemented in a 130nm BiCMOS process is presented. The driver IC incorporates an integrated 27-1 pseudo-random bit sequence (PRBS) generator for reliable high-speed testing, and a driver circuit featuring digitally-tuned pre-emphasis signal strength. With outstanding drive capability, the driver module can be applied to a wide range of carrier

Switching Characteristics of a 4H-SiC Based Bipolar Junction Transistor to 200 C

NASA Technical Reports Server (NTRS)

Niedra, Janis M.

2006-01-01

Static curves and resistive load switching characteristics of a 600 V, 4 A rated, SiC-based NPN bipolar power transistor (BJT) were observed at selected temperatures from room to 200 C. All testing was done in a pulse mode at low duty cycle (approx.0.1 percent). Turn-on was driven by an adjustable base current pulse and turn-off was accelerated by a negative base voltage pulse of 7 V. These base drive signals were implemented by 850 V, gated power pulsers, having rise-times of roughly 10 ns, or less. Base charge sweep-out with a 7 V negative pulse did not produce the large reverse base current pulse seen in a comparably rated Si-based BJT. This may be due to a very low charge storage time. The decay of the collector current was more linear than its exponential-like rise. Switching observations were done at base drive currents (I(sub B)) up to 400 mA and collector currents (I(sub C)) up to 4 A, using a 100 Omega non-inductive load. At I(sub B) = 400 mA and I(sub C) = 4 A, turn-on times typically varied from 80 to 94 ns, over temperatures from 23 to 200 C. As expected, lowering the base drive greatly extended the turn-on time. Similarly, decreasing the load current to I(sub C) = 1 A with I(sub B) = 400 mA produced turn-on times as short as 34 ns. Over the 23 to 200 C range, with I(sub B) = 400 mA and I(sub C) = 4 A, turn-off times were in the range of 72 to 84 ns with the 7 V sweep-out.

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

NASA Astrophysics Data System (ADS)

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

2016-05-01

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. Project supported by the National Natural Science Foundation of China (Grant No. 61501091) and the Fundamental Research Funds for the Central Universities of Ministry of Education of China (Grant Nos. ZYGX2014J003 and ZYGX2013J020).

A nonlinear macromodel of the bipolar integrated circuit operational amplifier for electromagnetic interference analysis

NASA Astrophysics Data System (ADS)

Chen, G. K. C.

1981-06-01

A nonlinear macromodel for the bipolar transistor integrated circuit operational amplifier is derived from the macromodel proposed by Boyle. The nonlinear macromodel contains only two nonlinear transistors in the input stage in a differential amplifier configuration. Parasitic capacitance effects are represented by capacitors placed at the collectors and emitters of the input transistors. The nonlinear macromodel is effective in predicting the second order intermodulation effect of operational amplifiers in a unity gain buffer amplifier configuration. The nonlinear analysis computer program NCAP is used for the analysis. Accurate prediction of demodulation of amplitude modulated RF signals with RF carrier frequencies in the 0.05 to 100 MHz range is achieved. The macromodel predicted results, presented in the form of second order nonlinear transfer function, come to within 6 dB of the full model predictions for the 741 type of operational amplifiers for values of the second order transfer function greater than -40 dB.

A Physics-Based Heterojunction Bipolar Transistor Model for Integrated Circuit Simulation

DTIC Science & Technology

1993-12-01

Laverghetta, Practical Microwaves, IN, Howard W. Sams & Co., 1984. [56] C. R . Selvakumar , "A New Minority Carrier Lifetime Model for Heavily Doped GaAs...transistor common-emitter output conductance (S). gm Small-signal transconductance (S). r Reflection coefficient of a transmission line. ’Y Emitter...material and geometry parameters to equivalent circuit element values. Typically, the first step in 6 C RC Re + VWc- +B B ,a W’ COE ’IIc I R E Figure 1.7

Atypical transistor-based chaotic oscillators: Design, realization, and diversity

NASA Astrophysics Data System (ADS)

Minati, Ludovico; Frasca, Mattia; OświÈ©cimka, Paweł; Faes, Luca; DroŻdŻ, Stanisław

2017-07-01

In this paper, we show that novel autonomous chaotic oscillators based on one or two bipolar junction transistors and a limited number of passive components can be obtained via random search with suitable heuristics. Chaos is a pervasive occurrence in these circuits, particularly after manual adjustment of a variable resistor placed in series with the supply voltage source. Following this approach, 49 unique circuits generating chaotic signals when physically realized were designed, representing the largest collection of circuits of this kind to date. These circuits are atypical as they do not trivially map onto known topologies or variations thereof. They feature diverse spectra and predominantly anti-persistent monofractal dynamics. Notably, we recurrently found a circuit comprising one resistor, one transistor, two inductors, and one capacitor, which generates a range of attractors depending on the parameter values. We also found a circuit yielding an irregular quantized spike-train resembling some aspects of neural discharge and another one generating a double-scroll attractor, which represent the smallest known transistor-based embodiments of these behaviors. Through three representative examples, we additionally show that diffusive coupling of heterogeneous oscillators of this kind may give rise to complex entrainment, such as lag synchronization with directed information transfer and generalized synchronization. The replicability and reproducibility of the experimental findings are good.

Atypical transistor-based chaotic oscillators: Design, realization, and diversity.

PubMed

Minati, Ludovico; Frasca, Mattia; Oświȩcimka, Paweł; Faes, Luca; Drożdż, Stanisław

2017-07-01

In this paper, we show that novel autonomous chaotic oscillators based on one or two bipolar junction transistors and a limited number of passive components can be obtained via random search with suitable heuristics. Chaos is a pervasive occurrence in these circuits, particularly after manual adjustment of a variable resistor placed in series with the supply voltage source. Following this approach, 49 unique circuits generating chaotic signals when physically realized were designed, representing the largest collection of circuits of this kind to date. These circuits are atypical as they do not trivially map onto known topologies or variations thereof. They feature diverse spectra and predominantly anti-persistent monofractal dynamics. Notably, we recurrently found a circuit comprising one resistor, one transistor, two inductors, and one capacitor, which generates a range of attractors depending on the parameter values. We also found a circuit yielding an irregular quantized spike-train resembling some aspects of neural discharge and another one generating a double-scroll attractor, which represent the smallest known transistor-based embodiments of these behaviors. Through three representative examples, we additionally show that diffusive coupling of heterogeneous oscillators of this kind may give rise to complex entrainment, such as lag synchronization with directed information transfer and generalized synchronization. The replicability and reproducibility of the experimental findings are good.

Vertical Hole Transport and Carrier Localization in InAs /InAs1 -xSbx Type-II Superlattice Heterojunction Bipolar Transistors

NASA Astrophysics Data System (ADS)

Olson, B. V.; Klem, J. F.; Kadlec, E. A.; Kim, J. K.; Goldflam, M. D.; Hawkins, S. D.; Tauke-Pedretti, A.; Coon, W. T.; Fortune, T. R.; Shaner, E. A.; Flatté, M. E.

2017-02-01

Heterojunction bipolar transistors are used to measure vertical hole transport in narrow-band-gap InAs /InAs1 -xSbx type-II superlattices (T2SLs). Vertical hole mobilities (μh) are reported and found to decrease rapidly from 360 cm2/V s at 120 K to approximately 2 cm2/V s at 30 K, providing evidence that holes are confined to localized states near the T2SL valence-miniband edge at low temperatures. Four distinct transport regimes are identified: (1) pure miniband transport, (2) miniband transport degraded by temporary capture of holes in localized states, (3) hopping transport between localized states in a mobility edge, and (4) hopping transport through defect states near the T2SL valence-miniband edge. Region (2) is found to have a thermal activation energy of ɛ2=36 meV corresponding to the energy range of a mobility edge. Region (3) is found to have a thermal activation energy of ɛ3=16 meV corresponding to the hopping transport activation energy. This description of vertical hole transport is analogous to electronic transport observed in disordered amorphous semiconductors displaying Anderson localization. For the T2SL, we postulate that localized states are created by disorder in the group-V alloy of the InAs1 -xSbx hole well causing fluctuations in the T2SL valence-band energy.

Transistor Effect in Improperly Connected Transistors.

ERIC Educational Resources Information Center

Luzader, Stephen; Sanchez-Velasco, Eduardo

1996-01-01

Discusses the differences between the standard representation and a realistic representation of a transistor. Presents an experiment that helps clarify the explanation of the transistor effect and shows why transistors should be connected properly. (JRH)

Monolithic integration of a GaAlAs buried-heterostructure laser and a bipolar phototransistor

NASA Technical Reports Server (NTRS)

Bar-Chaim, N.; Harder, CH.; Margalit, S.; Yariv, A.; Katz, J.; Ury, I.

1982-01-01

A GaAlAs buried-heterostructure laser has been monolithically integrated with a bipolar phototransistor. The heterojunction transistor was formed by the regrowth of the burying layers of the laser. Typical threshold current values for the lasers were 30 mA. Common-emitter current gains for the phototransistor of 100-400 and light responsitivity of 75 A/W (for wavelengths of 0.82 micron) at collector current levels of 15 mA were obtained.

Heuristic for learning common emitter amplification with bipolar transistors

NASA Astrophysics Data System (ADS)

Staffas, Kjell

2017-11-01

Mathematics in engineering education causes many thresholds in the courses because of the demand of abstract conceptualisation. Electronics depend heavily on more or less complex mathematics. Therefore the concepts of analogue electronics are hard to learn since a great deal of students struggle with the calculations and procedures needed. A survey was done focusing on students' struggle to pass a course in analogue electronics by introducing a top-down perspective and the revised taxonomy of Bloom. From a top-down perspective you can create learning environments from any spot in the taxonomy using a step-by-step approach of the verbs understand and apply. Three textbooks with a top-down perspective on analogue electronics are analysed on the concept of amplifying with a transistor circuit. The study claims issues when losing the top-down perspective to present concepts and procedures of the content to be learned.

10 K gate I(2)L and 1 K component analog compatible bipolar VLSI technology - HIT-2

NASA Astrophysics Data System (ADS)

Washio, K.; Watanabe, T.; Okabe, T.; Horie, N.

1985-02-01

An advanced analog/digital bipolar VLSI technology that combines on the same chip 2-ns 10 K I(2)L gates with 1 K analog devices is proposed. The new technology, called high-density integration technology-2, is based on a new structure concept that consists of three major techniques: shallow grooved-isolation, I(2)L active layer etching, and I(2)L current gain increase. I(2)L circuits with 80-MHz maximum toggle frequency have developed compatibly with n-p-n transistors having a BV(CE0) of more than 10 V and an f(T) of 5 GHz, and lateral p-n-p transistors having an f(T) of 150 MHz.

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

PubMed

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.

Evaluation of Anisotropic Biaxial Stress Induced Around Trench Gate of Si Power Transistor Using Water-Immersion Raman Spectroscopy

NASA Astrophysics Data System (ADS)

Suzuki, Takahiro; Yokogawa, Ryo; Oasa, Kohei; Nishiwaki, Tatsuya; Hamamoto, Takeshi; Ogura, Atsushi

2018-05-01

The trench gate structure is one of the promising techniques to reduce on-state resistance (R on) for silicon power devices, such as insulated gate bipolar transistors and power metal-oxide-semiconductor field-effect transistors. In addition, it has been reported that stress is induced around the trench gate area, modifying the carrier mobilities. We evaluated the one-dimensional distribution and anisotropic biaxial stress by quasi-line excitation and water-immersion Raman spectroscopy, respectively. The results clearly confirmed anisotropic biaxial stress in state-of-the-art silicon power devices. It is theoretically possible to estimate carrier mobility using piezoresistance coefficients and anisotropic biaxial stress. The electron mobility was increased while the hole mobility was decreased or remained almost unchanged in the silicon (Si) power device. The stress significantly modifies the R on of silicon power transistors. Therefore, their performance can be improved using the stress around the trench gate.

GaAsP/InGaP HBTs grown epitaxially on Si substrates: Effect of dislocation density on DC current gain

NASA Astrophysics Data System (ADS)

Heidelberger, Christopher; Fitzgerald, Eugene A.

2018-04-01

Heterojunction bipolar transistors (HBTs) with GaAs0.825P0.175 bases and collectors and In0.40Ga0.60P emitters were integrated monolithically onto Si substrates. The HBT structures were grown epitaxially on Si via metalorganic chemical vapor deposition, using SiGe compositionally graded buffers to accommodate the lattice mismatch while maintaining threading dislocation density at an acceptable level (˜3 × 106 cm-2). GaAs0.825P0.175 is used as an active material instead of GaAs because of its higher bandgap (increased breakdown voltage) and closer lattice constant to Si. Misfit dislocation density in the active device layers, measured by electron-beam-induced current, was reduced by making iterative changes to the epitaxial structure. This optimized process culminated in a GaAs0.825P0.175/In0.40Ga0.60P HBT grown on Si with a DC current gain of 156. By considering the various GaAsP/InGaP HBTs grown on Si substrates alongside several control devices grown on GaAs substrates, a wide range of threading dislocation densities and misfit dislocation densities in the active layers could be correlated with HBT current gain. The effect of threading dislocations on current gain was moderated by the reduction in minority carrier lifetime in the base region, in agreement with existing models for GaAs light-emitting diodes and photovoltaic cells. Current gain was shown to be extremely sensitive to misfit dislocations in the active layers of the HBT—much more sensitive than to threading dislocations. We develop a model for this relationship where increased base current is mediated by Fermi level pinning near misfit dislocations.

Cryogenic ultra-low-noise SiGe transistor amplifier.

PubMed

Ivanov, B I; Trgala, M; Grajcar, M; Il'ichev, E; Meyer, H-G

2011-10-01

An ultra-low-noise one-stage SiGe heterojunction bipolar transistor amplifier was designed for cryogenic temperatures and a frequency range of 10 kHz-100 MHz. A noise temperature T(N) ≈ 1.4 K was measured at an ambient temperature of 4.2 K at frequencies between 100 kHz and 100 MHz for a source resistance of ~50 Ω. The voltage gain of the amplifier was 25 dB at a power consumption of 720 μW. The input voltage noise spectral density of the amplifier is about 35 pV/√Hz. The low noise resistance and power consumption makes the amplifier suitable for readout of resistively shunted DC SQUID magnetometers and amplifiers.

Electrical characterisation of SiGe heterojunction bipolar transistors and Si pseudo-HBTS

NASA Astrophysics Data System (ADS)

De Barros, O.; Le Tron, B.; Woods, R. C.; Giroult-Matlakowski, G.; Vincent, G.; Brémond, G.

1996-08-01

This paper reports an electrical characterisation of the emitter-base junction of Si pseudo-HBTs and SiGe HBTs fabricated in a CMOS compatible single polysilicon self-aligned process. From the reverse characteristics it appears that the definition of the emitter-base junction by plasma etching induces peripheral defects that increase the base current of the transistors. Deep level transient spectroscopy measurements show a deep level in the case of SiGe base, whose spatial origin is not fully determinate up to now.

Extreme ultraviolet and Soft X-ray diagnostic upgrade on the HBT-EP tokamak: Progress and Results

NASA Astrophysics Data System (ADS)

Desanto, S.; Levesque, J. P.; Battey, A.; Brooks, J. W.; Mauel, M. E.; Navratil, G. A.; Hansen, C. J.

2017-10-01

In order to understand internal MHD mode structure in a tokamak plasma, it is helpful to understand temperature and density fluctuations within that plasma. In the HBT-EP tokamak, the plasma emits bremsstrahlung radiation in the extreme ultraviolet (EUV) and soft x-ray (SXR) regimes, and the emitted power is primarily related to electron density and temperature. This radiation is detected by photodiode arrays located at several different angular positions near the plasma's edge, each array making several views through a poloidal slice of plasma. From these measurements a 2-d emissivity profile of that slice can be reconstructed with tomographic algorithms. This profile cannot directly tell us whether the emissivity is due to electron density, temperature, line emission, or charge recombination; however, when combined with information from other diagnostics, it can provide strong evidence of the type of internal mode or modes depending on the temporal-spatial context. We present ongoing progress and results on the installation of a new system that will eventually consist of four arrays of 16 views each and a separate two-color, 16-chord tangential system, which will provide an improved understanding of the internal structure of HBT-EP plasmas. Supported by U.S. DOE Grant DE-FG02-86ER5322.

Collector-up aluminum gallium arsenide/gallium arsenide heterojunction bipolar transistors using oxidized aluminum arsenide for current confinement

NASA Astrophysics Data System (ADS)

Massengale, Alan Ross

1998-12-01

The discovery in 1990 that the wet thermal oxidation of AlAs can create a stable native oxide has added a new constituent, AlAs-oxide, to the AlGaAs/GaAs materials system. Native oxides of high Al mole-fraction AlGaAs are being used to confine electrical and/or optical fields in many types of electronic and optoelectronic structures with very promising results. Among these devices are collector-up heterojunction bipolar transistors (HBTs). Collector-up HBTs offer a means to reduce base-collector capacitance relative to their emitter-up counterparts, and thus to improve device performance. A novel method for fabricating collector-up AlGaAs/GaAs HBTs where an AlAs layer is inserted into the emitter layer and is oxidized in water vapor at 450sp°C has been developed. The resulting AlAs-oxide serves as a current confining layer that constricts collector current flow to the intrinsic portion of the device. Compared to previous methods of fabricating these devices, the process of converting AlAs into an insulator requires only one growth, and does not suffer from implant damage in the base. Because the lateral oxidation of AlAs is a process that proceeds at rates of microns per minute, one of the major challenges facing its implementation is the ability to accurately control the oxidation rate over the wafer, and from one wafer to the next. In the course of work on the oxidation of AlAs, a method to lithographically form lateral oxidation stop layers has been achieved. This technique utilizes impurity induced layer disordering (IILD) in heavily Si-doped buried planes, combined with selective surface patterning and thermal annealing, to create a lateral variation in the Al mole-fraction of the layer to be oxidized.

High-Power, High-Frequency Si-Based (SiGe) Transistors Developed

NASA Technical Reports Server (NTRS)

Ponchak, George E.

2002-01-01

Future NASA, DOD, and commercial products will require electronic circuits that have greater functionality and versatility but occupy less space and cost less money to build and integrate than current products. System on a Chip (SOAC), a single semiconductor substrate containing circuits that perform many functions or containing an entire system, is widely recognized as the best technology for achieving low-cost, small-sized systems. Thus, a circuit technology is required that can gather, process, store, and transmit data or communications. Since silicon-integrated circuits are already used for data processing and storage and the infrastructure that supports silicon circuit fabrication is very large, it is sensible to develop communication circuits on silicon so that all the system functions can be integrated onto a single wafer. Until recently, silicon integrated circuits did not function well at the frequencies required for wireless or microwave communications, but with the introduction of small amounts of germanium into the silicon to make silicon-germanium (SiGe) transistors, silicon-based communication circuits are possible. Although microwavefrequency SiGe circuits have been demonstrated, there has been difficulty in obtaining the high power from their transistors that is required for the amplifiers of a transmitter, and many researchers have thought that this could not be done. The NASA Glenn Research Center and collaborators at the University of Michigan have developed SiGe transistors and amplifiers with state-of-the-art output power at microwave frequencies from 8 to 20 GHz. These transistors are fabricated using standard silicon processing and may be integrated with CMOS integrated circuits on a single chip. A scanning electron microscope image of a typical SiGe heterojunction bipolar transistor is shown in the preceding photomicrograph. This transistor achieved a record output power of 550 mW and an associated power-added efficiency of 33 percent at 8

Psychotic and Bipolar Disorders: Bipolar Disorder.

PubMed

Holder, Sarah D

2017-04-01

Bipolar disorder is a severe chronic mental illness that affects a large number of individuals. This disorder is separated into two major types, bipolar I disorder, with mania and typically recurrent depression, and bipolar II disorder, with recurrent major depression and hypomania. Patients with bipolar disorder spend the majority of time experiencing depression, and this typically is the presenting symptom. Because outcomes are improved with earlier diagnosis and treatment, physicians should maintain a high index of suspicion for bipolar disorder. The most effective long-term treatments are lithium and valproic acid, although other drugs also are used. In addition to referral to a mental health subspecialist for initiation and management of drug treatment, patients with bipolar disorder should be provided with resources for psychotherapy. Several comorbidities commonly associated with bipolar disorder include other mental disorders, substance use disorders, migraine headaches, chronic pain, stroke, metabolic syndrome, and cardiovascular disease. Family physicians who care for patients with bipolar disorder should focus their efforts on prevention and management of comorbidities. These patients should be assessed continually for risk of suicide because they are at high risk and their suicide attempts tend to be successful. Written permission from the American Academy of Family Physicians is required for reproduction of this material in whole or in part in any form or medium.

A Cryogenic SiGe Low-noise Amplifier Optimized for Phased-array Feeds

NASA Astrophysics Data System (ADS)

Groves, Wavley M., III; Morgan, Matthew A.

2017-08-01

The growing number of phased-array feeds (PAF) being built for radio astronomy demonstrates an increasing need for low-noise amplifiers (LNA), which are designed for repeatability, low noise, and ease of manufacture. Specific design features that help to achieve these goals include the use of unpackaged transistors (for cryogenic operation); single-polarity biasing; straight plug-in radio frequency (RF) interfaces to facilitate installation and re-work; and the use of off-the-shelf components. The focal L-band array for the Green Bank Telescope (FLAG) is a cooperative effort by Brigham Young University and the National Radio Astronomy Observatory using warm dipole antennae and cryogenic Silicon Germanium Heterojunction Bipolar Transistor (SiGe HBT) LNAs. These LNAs have an in band gain average of 38 dB and 4.85 Kelvin average noise temperature. Although the FLAG instrument was the driving instrument behind this development, most of the key features of the design and the advantages they offer apply broadly to other array feeds, including independent-beam and phased, and for many antenna types such as horn, dipole, Vivaldi, connected-bowtie, etc. This paper focuses on the unique requirements array feeds have for low-noise amplifiers and how amplifier manufacturing can accommodate these needs.

VCO PLL Frequency Synthesizers for Spacecraft Transponders

NASA Technical Reports Server (NTRS)

Smith, Scott; Mysoor, Narayan; Lux, James; Cook, Brian

2007-01-01

Two documents discuss a breadboard version of advanced transponders that, when fully developed, would be installed on future spacecraft to fly in deep space. These transponders will be required to be capable of operation on any deepspace- communications uplink frequency channel between 7,145 and 7,235 MHz, and any downlink frequency channel between 8,400 and 8,500 MHz. The document focuses on the design and operation of frequency synthesizers for the receiver and transmitter. Heretofore, frequency synthesizers in deep-space transponders have been based on dielectric resonator oscillators (DROs), which do not have the wide tuning bandwidth necessary to tune over all channels in the uplink or downlink frequency bands. To satisfy the requirement for tuning bandwidth, the present frequency synthesizers are based on voltage-controlled-oscillator (VCO) phase-locked loops (PLLs) implemented by use of monolithic microwave integrated circuits (MMICs) implemented using inGaP heterojunction bipolar transistor (HBT) technology. MMIC VCO PLL frequency synthesizers similar to the present ones have been used in commercial and military applications but, until now, have exhibited too much phase noise for use in deep-space transponders. The present frequency synthesizers contain advanced MMIC VCOs, which use HBT technology and have lower levels of flicker (1/f) phase noise. When these MMIC VCOs are used with high-speed MMIC frequency dividers, it becomes possible to obtain the required combination of frequency agility and low phase noise.

STABILIZED TRANSISTOR AMPLIFIER

DOEpatents

Noe, J.B.

1963-05-01

A temperature stabilized transistor amplifier having a pair of transistors coupled in cascade relation that are capable of providing amplification through a temperature range of - 100 un. Concent 85% F to 400 un. Concent 85% F described. The stabilization of the amplifier is attained by coupling a feedback signal taken from the emitter of second transistor at a junction between two serially arranged biasing resistances in the circuit of the emitter of the second transistor to the base of the first transistor. Thus, a change in the emitter current of the second transistor is automatically corrected by the feedback adjustment of the base-emitter potential of the first transistor and by a corresponding change in the base-emitter potential of the second transistor. (AEC)

Electronic Model of a Ferroelectric Field Effect Transistor

NASA Technical Reports Server (NTRS)

MacLeod, Todd C.; Ho, Fat Duen; Russell, Larry (Technical Monitor)

2001-01-01

A pair of electronic models has been developed of a Ferroelectric Field Effect transistor. These models can be used in standard electrical circuit simulation programs to simulate the main characteristics of the FFET. The models use the Schmitt trigger circuit as a basis for their design. One model uses bipolar junction transistors and one uses MOSFET's. Each model has the main characteristics of the FFET, which are the current hysterisis with different gate voltages and decay of the drain current when the gate voltage is off. The drain current from each model has similar values to an actual FFET that was measured experimentally. T'he input and o Output resistance in the models are also similar to that of the FFET. The models are valid for all frequencies below RF levels. No attempt was made to model the high frequency characteristics of the FFET. Each model can be used to design circuits using FFET's with standard electrical simulation packages. These circuits can be used in designing non-volatile memory circuits and logic circuits and is compatible with all SPICE based circuit analysis programs. The models consist of only standard electrical components, such as BJT's, MOSFET's, diodes, resistors, and capacitors. Each model is compared to the experimental data measured from an actual FFET.

Bipolar Disorder.

PubMed

Miller, Thomas H

2016-06-01

Bipolar disorder is a chronic mental health disorder that is frequently encountered in primary care. Many patients with depression may actually have bipolar disorder. The management of bipolar disorder requires proper diagnosis and awareness or referral for appropriate pharmacologic therapy. Patients with bipolar disorder require primary care management for comorbidities such as cardiovascular and metabolic disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

All-optical transistor- and diode-action and logic gates based on anisotropic nonlinear responsive liquid crystal

PubMed Central

Wang, Cheng-Yu; Chen, Chun-Wei; Jau, Hung-Chang; Li, Cheng-Chang; Cheng, Chiao-Yu; Wang, Chun-Ta; Leng, Shi-Ee; Khoo, Iam-Choon; Lin, Tsung-Hsien

2016-01-01

In this paper, we show that anisotropic photosensitive nematic liquid crystals (PNLC) made by incorporating anisotropic absorbing dyes are promising candidates for constructing all-optical elements by virtue of the extraordinarily large optical nonlinearity of the nematic host. In particular, we have demonstrated several room-temperature ‘prototype’ PNLC-based all-optical devices such as optical diode, optical transistor and all primary logic gate operations (OR, AND, NOT) based on such optical transistor. Owing to the anisotropic absorption property and the optical activity of the twist alignment nematic cell, spatially non-reciprocal transmission response can be obtained within a sizeable optical isolation region of ~210 mW. Exploiting the same mechanisms, a tri-terminal configuration as an all-optical analogue of a bipolar junction transistor is fabricated. Its ability to be switched by an optical field enables us to realize an all-optical transistor and demonstrate cascadability, signal fan-out, logic restoration, and various logical gate operations such as OR, AND and NOT. Due to the possibility of synthesizing anisotropic dyes and wide ranging choice of liquid crystals nonlinear optical mechanisms, these all-optical operations can be optimized to have much lower thresholds and faster response speeds. The demonstrated capabilities of these devices have shown great potential in all-optical control system and photonic integrated circuits. PMID:27491391

All-optical transistor- and diode-action and logic gates based on anisotropic nonlinear responsive liquid crystal

NASA Astrophysics Data System (ADS)

Wang, Cheng-Yu; Chen, Chun-Wei; Jau, Hung-Chang; Li, Cheng-Chang; Cheng, Chiao-Yu; Wang, Chun-Ta; Leng, Shi-Ee; Khoo, Iam-Choon; Lin, Tsung-Hsien

2016-08-01

In this paper, we show that anisotropic photosensitive nematic liquid crystals (PNLC) made by incorporating anisotropic absorbing dyes are promising candidates for constructing all-optical elements by virtue of the extraordinarily large optical nonlinearity of the nematic host. In particular, we have demonstrated several room-temperature ‘prototype’ PNLC-based all-optical devices such as optical diode, optical transistor and all primary logic gate operations (OR, AND, NOT) based on such optical transistor. Owing to the anisotropic absorption property and the optical activity of the twist alignment nematic cell, spatially non-reciprocal transmission response can be obtained within a sizeable optical isolation region of ~210 mW. Exploiting the same mechanisms, a tri-terminal configuration as an all-optical analogue of a bipolar junction transistor is fabricated. Its ability to be switched by an optical field enables us to realize an all-optical transistor and demonstrate cascadability, signal fan-out, logic restoration, and various logical gate operations such as OR, AND and NOT. Due to the possibility of synthesizing anisotropic dyes and wide ranging choice of liquid crystals nonlinear optical mechanisms, these all-optical operations can be optimized to have much lower thresholds and faster response speeds. The demonstrated capabilities of these devices have shown great potential in all-optical control system and photonic integrated circuits.

All-optical transistor- and diode-action and logic gates based on anisotropic nonlinear responsive liquid crystal.

PubMed

Wang, Cheng-Yu; Chen, Chun-Wei; Jau, Hung-Chang; Li, Cheng-Chang; Cheng, Chiao-Yu; Wang, Chun-Ta; Leng, Shi-Ee; Khoo, Iam-Choon; Lin, Tsung-Hsien

2016-08-05

In this paper, we show that anisotropic photosensitive nematic liquid crystals (PNLC) made by incorporating anisotropic absorbing dyes are promising candidates for constructing all-optical elements by virtue of the extraordinarily large optical nonlinearity of the nematic host. In particular, we have demonstrated several room-temperature 'prototype' PNLC-based all-optical devices such as optical diode, optical transistor and all primary logic gate operations (OR, AND, NOT) based on such optical transistor. Owing to the anisotropic absorption property and the optical activity of the twist alignment nematic cell, spatially non-reciprocal transmission response can be obtained within a sizeable optical isolation region of ~210 mW. Exploiting the same mechanisms, a tri-terminal configuration as an all-optical analogue of a bipolar junction transistor is fabricated. Its ability to be switched by an optical field enables us to realize an all-optical transistor and demonstrate cascadability, signal fan-out, logic restoration, and various logical gate operations such as OR, AND and NOT. Due to the possibility of synthesizing anisotropic dyes and wide ranging choice of liquid crystals nonlinear optical mechanisms, these all-optical operations can be optimized to have much lower thresholds and faster response speeds. The demonstrated capabilities of these devices have shown great potential in all-optical control system and photonic integrated circuits.

Mode control using two electrodes on HBT-EP

NASA Astrophysics Data System (ADS)

Stewart, I. G.; Brooks, J. W.; Levesque, J. P.; Mauel, M. E.; Navratil, G. A.

2017-10-01

Understanding the effects of plasma rotation on magnetohydrodynamic (MHD) modes and tokamak plasma stability is important for performance enhancement of current magnetic confinement experiments and to future fusion devices such as ITER. In order to control plasma rotation, two molybdenum electrodes have been installed on HBT-EP toroidally separated by 144 degrees. This allows independent biasing of the two probes both spatially and temporally. When the bias probes are inserted into the edge of the plasma and a voltage is applied, the probes drive radial currents and produce plasma flow from the torque induced by the currents. If the bias probe voltage is sufficiently positive, the MHD mode rotation transitions into a state with a rapid mode rotation frequency (in excess of 25 kHz) in the direction opposite to mode rotation without bias. The transition into this reversed rotation state occurs when the torque exceeds a threshold, which can depend upon the phase of an applied n = 1 error field. We present recent studies of the two-electrode system on mode rotation, mode stability, and the toroidal symmetry of the radial current through the scrape-off-layer (SOL) during MHD activity and applied magnetic perturbations. Supported by U.S. DOE Grant DE-FG02-86ER53222.

DC power limitation of the heterojunction bipolar transistor with dot geometry: Effect of base potential distribution on thermal runaway

NASA Astrophysics Data System (ADS)

Liou, L. L.; Jenkins, T.; Huang, C. I.

1997-06-01

The d.c. power limitation of a conventional HBT with dot geometry was studied theoretically using combined electro-thermal and transmission line models. In most cases, the thermal runaway occurs at a power level lower than that set by the intrinsic electronic property of the device. The dependence of the d.c. thermal runaway threshold power density, Pmax, on the emitter dot radius and emitter ballast resistance was calculated. Increasing emitter dot radius lowers Pmax. Although ballast resistance increases Pmax, the effect reduces as the emitter dot radius increases. This is caused by the non-uniform potential distribution in the base layer. When thermal runaway is considered, the nonuniform base-emitter potential offsets the improvement of the power handling capability by the physical ballast resistance. Conventional HBTs with a large radius (greater than 4 μm) exhibit a small Pmax caused by thermal effect. This threshold power density can be increased drastically by using the thermal shunt technique.

The role of optoelectronic feedback on Franz-Keldysh voltage modulation of transistor lasers

NASA Astrophysics Data System (ADS)

Chang, Chi-Hsiang; Chang, Shu-Wei; Wu, Chao-Hsin

2016-03-01

Possessing both the high-speed characteristics of heterojunction bipolar transistors (HBTs) and enhanced radiative recombination of quantum wells (QWs), the light-emitting transistor (LET) which operates in the regime of spontaneous emissions has achieved up to 4.3 GHz modulation bandwidth. A 40 Gbit/s transmission rate can be even achieved using transistor laser (TL). The transistor laser provides not only the current modulation but also direct voltage-controlled modulation scheme of optical signals via Franz-Keldysh (FK) photon-assisted tunneling effect. In this work, the effect of FK absorption on the voltage modulation of TLs is investigated. In order to analyze the dynamics and optical responses of voltage modulation in TLs, the conventional rate equations relevant to diode lasers (DLs) are first modified to include the FK effect intuitively. The theoretical results of direct-current (DC) and small-signal alternating-current (AC) characteristics of optical responses are both investigated. While the DC characteristics look physical, the intrinsic optical response of TLs under the FK voltage modulation shows an AC enhancement with a 20 dB peak, which however is not observed in experiment. A complete model composed of the intrinsic optical transfer function and an electrical transfer function fed back by optical responses is proposed to explain the behaviors of voltage modulation in TLs. The abnormal AC peak disappears through this optoelectronic feedback. With the electrical response along with FK-included photon-carrier rate equations taken into account, the complete voltage-controlled optical modulation response of TLs is demonstrated.

Direct observation of lifetime killing defects in 4H SiC epitaxial layers through spin dependent recombination in bipolar junction transistors

NASA Astrophysics Data System (ADS)

Cochrane, C. J.; Lenahan, P. M.; Lelis, A. J.

2009-03-01

We have identified a magnetic resonance spectrum associated with minority carrier lifetime killing defects in device quality 4H SiC through magnetic resonance measurements in bipolar junction transistors using spin dependent recombination (SDR). The SDR spectrum has nine distinguishable lines; it is, within experimental error, essentially isotropic with four distinguishable pairs of side peaks symmetric about the strong center line. The line shape is, within experimental error, independent of bias voltage and recombination current. The large amplitude and spacing of the inner pair of side peaks and three more widely separated pairs of side peaks are not consistent with either a simple silicon or carbon vacancy or a carbon or silicon antisite. This indicates that the lifetime killing defect is not a simple defect but a defect aggregate. The spectrum is consistent with a multidefect cluster with an electron spin S =1/2. (The observed spectrum has not been reported previously in the magnetic resonance literature on SiC.) A fairly strong argument can be made in terms of a first order model linking the SDR spectrum to a divacancy or possibly a vacancy/antisite pair. The SDR amplitude versus gate voltage is semiquantitatively consistent with a very simple model in which the defect is uniformly distributed within the depletion region of the base/collector junction and is also the dominating recombination center. The large relative amplitude of the SDR response is more nearly consistent with a Kaplan-Solomon-Mott-like model for spin dependent recombination than the Lepine model.

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

PubMed Central

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

Doped Organic Transistors.

PubMed

Lüssem, Björn; Keum, Chang-Min; Kasemann, Daniel; Naab, Ben; Bao, Zhenan; Leo, Karl

2016-11-23

Organic field-effect transistors hold the promise of enabling low-cost and flexible electronics. Following its success in organic optoelectronics, the organic doping technology is also used increasingly in organic field-effect transistors. Doping not only increases device performance, but it also provides a way to fine-control the transistor behavior, to develop new transistor concepts, and even improve the stability of organic transistors. This Review summarizes the latest progress made in the understanding of the doping technology and its application to organic transistors. It presents the most successful doping models and an overview of the wide variety of materials used as dopants. Further, the influence of doping on charge transport in the most relevant polycrystalline organic semiconductors is reviewed, and a concise overview on the influence of doping on transistor behavior and performance is given. In particular, recent progress in the understanding of contact doping and channel doping is summarized.

Rapid thermal anneal in InP, GaAs and GaAs/GaAlAs

NASA Astrophysics Data System (ADS)

Descouts, B.; Duhamel, N.; Godefroy, S.; Krauz, P.

Ion implantation in semiconductors provides a doping technique with several advantages over more conventional doping methods and is now extensively used for device applications, e.g. field effect transistors (MESFET GaAs, MIS (InP), GaAs/GaAlAs heterojunction bipolar transistors (HBT). Because of the lattice disorder produced by the implantation, the dopant must be made electrically active by a postimplant anneal. As the device performances are very dependent on its electrical characteristics, the anneal is a very important stage of the process. Rapid anneal is known to provide less exodiffusion and less induffusion of impurities compared to conventional furnace anneal, so this technique has been used in this work to activate an n-type dopant (Si) in InP and a p-type dopant (Mg) in GaAs and GaAs/GaAIAs. These two ions have been chosen to realize implanted MIS InP and the base contacts for GaAs/GaAlAs HBTs. The experimental conditions to obtain the maximum electrical activity in these two cases will be detailed. For example, although we have not been able to obtain a flat profile in Mg + implanted GaAs/GaAlAs heterostructure by conventional thermal anneal, rapid thermal anneal gives a flat hole profile over a depth of 0.5 μm with a concentration of 1 x 10 19 cm -3.

On the wide-range bias dependence of transistor d.c. and small-signal current gain factors.

NASA Technical Reports Server (NTRS)

Schmidt, P.; Das, M. B.

1972-01-01

Critical reappraisal of the bias dependence of the dc and small-signal ac current gain factors of planar bipolar transistors over a wide range of currents. This is based on a straightforward consideration of the three basic components of the dc base current arising due to emitter-to-base injected minority carrier transport, base-to-emitter carrier injection, and emitter-base surface depletion layer recombination effects. Experimental results on representative n-p-n and p-n-p silicon devices are given which support most of the analytical findings.

A CMOS-Compatible, Low-Noise ISFET Based on High Efficiency Ion-Modulated Lateral-Bipolar Conduction

PubMed Central

Chang, Sheng-Ren; Chen, Hsin

2009-01-01

Ion-sensitive, field-effect transistors (ISFET) have been useful biosensors in many applications. However, the signal-to-noise ratio of the ISFET is limited by its intrinsic, low-frequency noise. This paper presents an ISFET capable of utilizing lateral-bipolar conduction to reduce low-frequency noise. With a particular layout design, the conduction efficiency is further enhanced. Moreover, the ISFET is compatible with the standard CMOS technology. All materials above the gate-oxide are removed by simple, die-level post-CMOS process, allowing ions to modulate the lateral-bipolar current directly. By varying the gate-to-bulk voltage, the operation mode of the ISFET is controlled effectively, so is the noise performance measured and compared. Finally, the biasing conditions preferable for different low-noise applications are identified. Under the identified biasing condition, the signal-to-noise ratio of the ISFET as a pH sensor is proved to be improved by more than five times. PMID:22408508

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

PubMed Central

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

High-Speed, High-Power Active Control Coils for HBT-EP

NASA Astrophysics Data System (ADS)

Debono, Bryan

2010-11-01

We report the performance of a newly installed high-speed, high-power active control system for the application of non-symmetric magnetic fields and the study of rotating MHD and resistive wall modes in the HBTEP tokamak. The new control system consists of an array of 120 modular control coils and 40 solid-state, high-power amplifiers that can apply non-symmetric control fields that are more than 10 times larger than previous studies in HBT-EP and exceed 5% of the equilibrium poloidal field strength. Measurements of the current and field response of the control system are presented as a function of frequency and control coil geometry, and these demonstrate the effectiveness of the system to interact with both growing RWM instabilities and long-wavelength modes rotating with the plasma. We describe a research plan to study the interaction of both kink and tearing mode fluctuations with applied static and rotating magnetic perturbations while systematically changing the plasma rotation with a biased molybdenum electrode inserted into the edge plasma.

An accurate two-dimensional LBIC solution for bipolar transistors

NASA Astrophysics Data System (ADS)

Benarab, A.; Baudrand, H.; Lescure, M.; Boucher, J.

1988-05-01

A complete solution of the diffusion problem of carriers generated by a located light beam in the emitter and base region of a bipolar structure is presented. Green's function method and moment method are used to solve the 2-D diffusion equation in these regions. From the Green's functions solution of these equations, the light beam induced currents (LBIC) in the different junctions of the structure due to an extended generation represented by a rectangular light spot; are thus decided. The equations of these currents depend both on the parameters which characterise the structure, surface states, dimensions of the emitter and the base region, and the characteristics of the light spot, that is to say, the width and the wavelength. Curves illustrating the variation of the various LBIC in the base region junctions as a function of the impact point of the light beam ( x0) for different values of these parameters are discussed. In particular, the study of the base-emitter currents when the light beam is swept right across the sample illustrates clearly a good geometrical definition of the emitter region up to base end of the emitter-base space-charge areas and a "whirl" lateral diffusion beneath this region, (i.e. the diffusion of the generated carriers near the surface towards the horizontal base-emitter junction and those created beneath this junction towards the lateral (B-E) junctions).

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

PubMed

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.

EDITORIAL: Reigniting innovation in the transistor Reigniting innovation in the transistor

NASA Astrophysics Data System (ADS)

Demming, Anna

2012-09-01

Today the transistor is integral to the electronic circuitry that wires our lives. When Bardeen and Brattain first observed an amplified signal by connecting electrodes to a germanium crystal they saw that their 'semiconductor triode' could prove a useful alternative to the more cumbersome vacuum tubes used at the time [1]. But it was perhaps William Schottky who recognized the extent of the transistor's potential. A basic transistor has three or more terminals and current across one pair of terminals can switch or amplify current through another pair. Bardeen, Brattain and Schottky were jointly awarded a Nobel Prize in 1956 'for their researches on semiconductors and their discovery of the transistor effect' [2]. Since then many new forms of the transistor have been developed and understanding of the underlying properties is constantly advancing. In this issue Chen and Shih and colleagues at Taiwan National University and Drexel University report a pyroelectrics transistor. They show how a novel optothermal gating mechanism can modulate the current, allowing a range of developments in nanoscale optoelectronics and wireless devices [3]. The explosion of interest in nanoscale devices in the 1990s inspired electronics researchers to look for new systems that can act as transistors, such as carbon nanotube [4] and silicon nanowire [5] transistors. Generally these transistors function by raising and lowering an energy barrier of kBT -1, but researchers in the US and Canada have demonstrated that the quantum interference between two electronic pathways through aromatic molecules can also modulate the current flow [6]. The device has advantages for further miniaturization where energy dissipation in conventional systems may eventually cause complications. Interest in transistor technology has also led to advances in fabrication techniques for achieving high production quantities, such as printing [7]. Researchers in Florida in the US demonstrated field effect transistor

Single-event burnout of n-p-n bipolar-junction transistors in hybrid DC/DC converters

NASA Astrophysics Data System (ADS)

Warren, K.; Roth, D.; Kinnison, J.; Pappalardo, R.

2002-12-01

Single-event-induced failure of the Lambda Advanced Analog AMF2805S DC/DC Converter has been traced to burnout of an n-p-n transistor in the MOSFET drive stage. The failures were observed during testing while in inhibit mode only. Modifications to prevent burnout of the drive stage were successfully employed. A discussion of the failure mechanism and consequences for DC/DC converter testing are presented.

BIMOS transistor solutions for ESD protection in FD-SOI UTBB CMOS technology

NASA Astrophysics Data System (ADS)

Galy, Philippe; Athanasiou, S.; Cristoloveanu, S.

2016-01-01

We evaluate the Electro-Static Discharge (ESD) protection capability of BIpolar MOS (BIMOS) transistors integrated in ultrathin silicon film for 28 nm Fully Depleted SOI (FD-SOI) Ultra Thin Body and BOX (UTBB) high-k metal gate technology. Using as a reference our measurements in hybrid bulk-SOI structures, we extend the BIMOS design towards the ultrathin silicon film. Detailed study and pragmatic evaluations are done based on 3D TCAD simulation with standard physical models using Average Current Slope (ACS) method and quasi-static DC stress (Average Voltage Slope AVS method). These preliminary 3D TACD results are very encouraging in terms of ESD protection efficiency in advanced FD-SOI CMOS.

Transistor-based interface circuitry

DOEpatents

Taubman, Matthew S [Richland, WA

2007-02-13

Among the embodiments of the present invention is an apparatus that includes a transistor, a servo device, and a current source. The servo device is operable to provide a common base mode of operation of the transistor by maintaining an approximately constant voltage level at the transistor base. The current source is operable to provide a bias current to the transistor. A first device provides an input signal to an electrical node positioned between the emitter of the transistor and the current source. A second device receives an output signal from the collector of the transistor.

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

PubMed

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.

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

PubMed Central

Martí, A.; Luque, A.

2015-01-01

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. PMID:25902374

Bipolar disorders.

PubMed

Vieta, Eduard; Berk, Michael; Schulze, Thomas G; Carvalho, André F; Suppes, Trisha; Calabrese, Joseph R; Gao, Keming; Miskowiak, Kamilla W; Grande, Iria

2018-03-08

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. Psychiatric and nonpsychiatric medical comorbidities are common in patients and might also contribute to increased mortality. Bipolar disorders are some of the most heritable psychiatric disorders, although a model with gene-environment interactions is believed to best explain the aetiology. Early 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 the significance of their symptoms, especially with hypomanic or manic symptoms. As specific biomarkers for bipolar disorders are not yet available, careful clinical assessment remains the cornerstone of diagnosis. The detection of hypomanic symptoms and longtudinal clinical assessment are crucial to differentiate 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.

Low-voltage all-inorganic perovskite quantum dot transistor memory

NASA Astrophysics Data System (ADS)

Chen, Zhiliang; Zhang, Yating; Zhang, Heng; Yu, Yu; Song, Xiaoxian; Zhang, Haiting; Cao, Mingxuan; Che, Yongli; Jin, Lufan; Li, Yifan; Li, Qingyan; Dai, Haitao; Yang, Junbo; Yao, Jianquan

2018-05-01

An all-inorganic cesium lead halide quantum dot (QD) based Au nanoparticle (NP) floating-gate memory with a solution processed layer-by-layer method is demonstrated. Easy synthesis at room temperature and excellent stability make all-inorganic CsPbBr3 perovskite QDs suitable as a semiconductor layer in low voltage nonvolatile transistor memory. The bipolarity of QDs has both electrons and holes stored in the Au NP floating gate, resulting in bidirectional shifts of initial threshold voltage according to the applied programing and erasing pulses. Under low operation voltage (±5 V), the memory achieved a great memory window (˜2.4 V), long retention time (>105 s), and stable endurance properties after 200 cycles. So the proposed memory device based on CsPbBr3 perovskite QDs has a great potential in the flash memory market.

Test simulation of neutron damage to electronic components using accelerator facilities

NASA Astrophysics Data System (ADS)

King, D. B.; Fleming, R. M.; Bielejec, E. S.; McDonald, J. K.; Vizkelethy, G.

2015-12-01

The purpose of this work is to demonstrate equivalent bipolar transistor damage response to neutrons and silicon ions. We report on irradiation tests performed at the White Sands Missile Range Fast Burst Reactor, the Sandia National Laboratories (SNL) Annular Core Research Reactor, the SNL SPHINX accelerator, and the SNL Ion Beam Laboratory using commercial silicon npn bipolar junction transistors (BJTs) and III-V Npn heterojunction bipolar transistors (HBTs). Late time and early time gain metrics as well as defect spectra measurements are reported.

Bipolar disorder.

PubMed

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

2016-04-09

Bipolar disorder is a recurrent chronic disorder characterised by fluctuations in mood state and energy. It affects more than 1% of the world's population irrespective of nationality, ethnic origin, or socioeconomic status. Bipolar disorder is one of the main causes of disability among young people, leading to cognitive and functional impairment and raised mortality, particularly death by suicide. A high prevalence of psychiatric and medical comorbidities is typical in affected individuals. Accurate diagnosis of bipolar disorder is difficult in clinical practice because onset is most commonly a depressive episode and looks similar to unipolar depression. Moreover, there are currently no valid biomarkers for the disorder. Therefore, the role of clinical assessment remains key. Detection of hypomanic periods and longitudinal assessment are crucial to differentiate bipolar disorder from other conditions. Current knowledge of the evolving pharmacological and psychological strategies in bipolar disorder is of utmost importance. Copyright © 2016 Elsevier Ltd. All rights reserved.

VOLTAGE-CONTROLLED TRANSISTOR OSCILLATOR

DOEpatents

Scheele, P.F.

1958-09-16

This patent relates to transistor oscillators and in particular to those transistor oscillators whose frequencies vary according to controlling voltages. A principal feature of the disclosed transistor oscillator circuit resides in the temperature compensation of the frequency modulating stage by the use of a resistorthermistor network. The resistor-thermistor network components are selected to have the network resistance, which is in series with the modulator transistor emitter circuit, vary with temperature to compensate for variation in the parameters of the transistor due to temperature change.

Radiation-hardened transistor and integrated circuit

DOEpatents

Ma, Kwok K.

2007-11-20

A composite transistor is disclosed for use in radiation hardening a CMOS IC formed on an SOI or bulk semiconductor substrate. The composite transistor has a circuit transistor and a blocking transistor connected in series with a common gate connection. A body terminal of the blocking transistor is connected only to a source terminal thereof, and to no other connection point. The blocking transistor acts to prevent a single-event transient (SET) occurring in the circuit transistor from being coupled outside the composite transistor. Similarly, when a SET occurs in the blocking transistor, the circuit transistor prevents the SET from being coupled outside the composite transistor. N-type and P-type composite transistors can be used for each and every transistor in the CMOS IC to radiation harden the IC, and can be used to form inverters and transmission gates which are the building blocks of CMOS ICs.

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

PubMed

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.

Recent HBT results in Au+Au and p+p collisions from PHENIX

NASA Astrophysics Data System (ADS)

PHENIX Collaboration; Glenn, Andrew; PHENIX Collaboration

2009-11-01

We present Hanbury-Brown Twiss measurements from the PHENIX experiment at RHIC for final results for charged kaon pairs from s=200 GeV Au+Au collisions and preliminary results for charged pion pairs from s=200 GeVp+p collisions. We find that for kaon pairs from Au+Au, each traditional 3D Gaussian radius shows approximately the same linear increase as a function of Npart1/3. An imaging analysis reveals a significant non-Gaussian tail for r≳10 fm. The presence of a tail for kaon pairs demonstrates that similar non-Gaussian tails observed in earlier pion measurements cannot be fully explained by decays of long-lived resonances. The preliminary analysis of pions from s=200 GeV p+p minimum biased collisions show correlations which are well suited to traditional 3D HBT radii extraction via the Bowler-Sinyukov method, and we present R, R, and R as a function of mean transverse pair mass.

A D-band Active Imager in a SiGe HBT Technology

NASA Astrophysics Data System (ADS)

Yoon, Daekeun; Song, Kiryong; Kim, Jungsoo; Kaynak, Mehmet; Tillack, Bernd; Rieh, Jae-Sung

2015-04-01

In this paper, an amplifier and a detector operating near 140 GHz have been developed and integrated together with an on-chip antenna for an integrated active imager based on a 0.13-μm SiGe HBT technology. The 5-stage differential common-emitter (CE) amplifier shows a peak gain of 14 dB and noise figure (NF) down to 10 dB around 140 GHz with a DC power dissipation of 18 mW. The common-base (CB) differential detector exhibits a peak responsivity of 52.5 kV/W and a noise equivalent power (NEP) of 3.3 pW/Hz1/2. For the integrated imager, a peak responsivity of 1,740 kV/W and a minimum NEP of 80 fW/Hz1/2 were achieved with a DC power dissipation of 18 mW. With the fabricated active imager with on-chip antenna, which occupies an area of 2,200 × 600 μm2 including the antenna and bonding pads, images of various objects were successfully acquired.

Bipolar disorder in adolescence.

PubMed

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.

Bipolar Disorder - Multiple Languages

MedlinePlus

... Russian (Русский) Expand Section Bipolar Disorder (An Introduction) - English PDF Bipolar Disorder (An Introduction) - Русский (Russian) PDF Bipolar Disorder (An Introduction) - English MP3 Bipolar Disorder (An Introduction) - Русский (Russian) MP3 ...

Teaching the Common Emitter Amplifier.

ERIC Educational Resources Information Center

Ellse, Mark D.

1984-01-01

Describes experiments in which a bipolar transistor is used to examine the behavior of a simple circuit. Also addresses problems in teaching the related concepts. (The experiments can be modified to incorporate devices other than bipolar transistors.) (JN)

Bipolar disorder: diagnostic issues.

PubMed

Tiller, John W G; Schweitzer, Isaac

2010-08-16

Bipolar disorders are cyclical mood disorders with clinical features including distinct sustained periods of mood elevation. Briefer (4 days or more), mild episodes of mood elevation define bipolar II disorder; lengthier (7 days or more), more severe episodes (or those requiring hospitalisation), with or without psychotic features, define bipolar I disorder. Depressive periods are more common and lengthier than manic or hypomanic states, and are the main cause of disability. Bipolar depression may respond poorly to antidepressants and these medications may destabilise the illness. The diagnosis of bipolar disorder should be considered when a patient with depression is treatment resistant. Irritability is a common symptom in bipolar disorder, particularly during mixed states (during which patients have features of mood elevation and depression concurrently) or when there is rapid cycling of mood (more than four episodes of mood disorder per year). Alcohol misuse and use of illicit drugs may simulate mood changes in bipolar disorder. Accurate diagnosis and assessment of bipolar disorder is essential for clinical decision making and determining prognosis and treatments.

Giant electron-hole transport asymmetry in ultra-short quantum transistors.

PubMed

McRae, A C; Tayari, V; Porter, J M; Champagne, A R

2017-05-31

Making use of bipolar transport in single-wall carbon nanotube quantum transistors would permit a single device to operate as both a quantum dot and a ballistic conductor or as two quantum dots with different charging energies. Here we report ultra-clean 10 to 100 nm scale suspended nanotube transistors with a large electron-hole transport asymmetry. The devices consist of naked nanotube channels contacted with sections of tube under annealed gold. The annealed gold acts as an n-doping top gate, allowing coherent quantum transport, and can create nanometre-sharp barriers. These tunnel barriers define a single quantum dot whose charging energies to add an electron or a hole are vastly different (e-h charging energy asymmetry). We parameterize the e-h transport asymmetry by the ratio of the hole and electron charging energies η e-h . This asymmetry is maximized for short channels and small band gap tubes. In a small band gap device, we demonstrate the fabrication of a dual functionality quantum device acting as a quantum dot for holes and a much longer quantum bus for electrons. In a 14 nm-long channel, η e-h reaches up to 2.6 for a device with a band gap of 270 meV. The charging energies in this device exceed 100 meV.

Giant electron-hole transport asymmetry in ultra-short quantum transistors

PubMed Central

McRae, A. C.; Tayari, V.; Porter, J. M.; Champagne, A. R.

2017-01-01

Making use of bipolar transport in single-wall carbon nanotube quantum transistors would permit a single device to operate as both a quantum dot and a ballistic conductor or as two quantum dots with different charging energies. Here we report ultra-clean 10 to 100 nm scale suspended nanotube transistors with a large electron-hole transport asymmetry. The devices consist of naked nanotube channels contacted with sections of tube under annealed gold. The annealed gold acts as an n-doping top gate, allowing coherent quantum transport, and can create nanometre-sharp barriers. These tunnel barriers define a single quantum dot whose charging energies to add an electron or a hole are vastly different (e−h charging energy asymmetry). We parameterize the e−h transport asymmetry by the ratio of the hole and electron charging energies ηe−h. This asymmetry is maximized for short channels and small band gap tubes. In a small band gap device, we demonstrate the fabrication of a dual functionality quantum device acting as a quantum dot for holes and a much longer quantum bus for electrons. In a 14 nm-long channel, ηe−h reaches up to 2.6 for a device with a band gap of 270 meV. The charging energies in this device exceed 100 meV. PMID:28561024

High temperature bias line stabilized current sources

DOEpatents

Patterson, III, Raymond B.

1984-01-01

A compensation device for the base of emitter follower configured bipolar transistors becoming operable at elevated temperatures including a bipolar transistor of a geometry of not more than half the geometry of the bipolar emitter follower having its collector connected to the base of the emitter follower and its base and emitter connected together and to the emitter of the emitter follower.

Azimuthal Angle Dependence of HBT Radii in Au+Au Collisions at RHIC-PHENIX

NASA Astrophysics Data System (ADS)

Niida, Takafumi

Measurement of Hanbury-Brown and Twiss (HBT) interferometry with respect to the event plane have been performed in Au+Au collisions at √{sNN} = 200 GeV at PHENIX, which is a unique tool to study the spatial extent of the created matter at final state in heavy ion collisions and the detailed picture of the space-time evolution from the initial state to the final state. The Gaussian source radii was measured for charged pions and kaons with respect to 2nd-order event plane. There was a difference in final eccentricity between both species, which may imply the different freeze-out mechanism by the particle species. The pion source radii was also measured relative to 3rd-order event plane, and the azimuthal angle dependence of the radii was observed, which qualitatively agrees with the recent hydrodynamic calculation and the oscillation may be driven from the triangular flow.

Bipolar disorder

MedlinePlus

... bipolar symptoms worse and increase the risk of suicide. Episodes of depression are more common than episodes of mania. The ... have problems with relationships, school, work, and finances. ... and depression. People with bipolar disorder who think or talk ...

Copper atomic-scale transistors.

PubMed

Xie, Fangqing; Kavalenka, Maryna N; Röger, Moritz; Albrecht, Daniel; Hölscher, Hendrik; Leuthold, Jürgen; Schimmel, Thomas

2017-01-01

We investigated copper as a working material for metallic atomic-scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO 4 + H 2 SO 4 ) in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate). The electrochemical switching-on potential of the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and -170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes ( U bias ) influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper atomic-scale transistors, with only one or two atoms at the narrowest constriction, were realized to switch between 0 and 1 G 0 ( G 0 = 2e 2 /h; with e being the electron charge, and h being Planck's constant) or 2 G 0 by the function generator. The switching rate can reach up to 10 Hz. The copper atomic-scale transistor demonstrates volatile/non-volatile dual functionalities. Such an optimal merging of the logic with memory may open a perspective for processor-in-memory and logic-in-memory architectures, using copper as an alternative working material besides silver for fully metallic atomic-scale transistors.

Copper atomic-scale transistors

PubMed Central

Kavalenka, Maryna N; Röger, Moritz; Albrecht, Daniel; Hölscher, Hendrik; Leuthold, Jürgen

2017-01-01

We investigated copper as a working material for metallic atomic-scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO4 + H2SO4) in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate). The electrochemical switching-on potential of the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and −170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes (U bias) influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper atomic-scale transistors, with only one or two atoms at the narrowest constriction, were realized to switch between 0 and 1G 0 (G 0 = 2e2/h; with e being the electron charge, and h being Planck’s constant) or 2G 0 by the function generator. The switching rate can reach up to 10 Hz. The copper atomic-scale transistor demonstrates volatile/non-volatile dual functionalities. Such an optimal merging of the logic with memory may open a perspective for processor-in-memory and logic-in-memory architectures, using copper as an alternative working material besides silver for fully metallic atomic-scale transistors. PMID:28382242

Dual-Gate p-GaN Gate High Electron Mobility Transistors for Steep Subthreshold Slope.

PubMed

Bae, Jong-Ho; Lee, Jong-Ho

2016-05-01

A steep subthreshold slope characteristic is achieved through p-GaN gate HEMT with dual-gate structure. Obtained subthreshold slope is less than 120 μV/dec. Based on the measured and simulated data obtained from single-gate device, breakdown of parasitic floating-base bipolar transistor and floating gate charged with holes are responsible to increase abruptly in drain current. In the dual-gate device, on-current degrades with high temperature but subthreshold slope is not changed. To observe the switching speed of dual-gate device and transient response of drain current are measured. According to the transient responses of drain current, switching speed of the dual-gate device is about 10(-5) sec.

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

PubMed

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

Power Supply Fault Tolerant Reliability Study

DTIC Science & Technology

1991-04-01

easier to design than for equivalent bipolar transistors. MCDONNELL DOUGLAS ELECTRONICS SYSTEMS COMPANY 9. Base circuitry should be designed to drive...SWITCHING REGULATORS (Ref. 28), SWITCHING AND LINEAR POWER SUPPLY DESIGN (Ref. 25) 6. Sequence the turn-off/turn-on logic in an orderly and controllable ...for equivalent bipolar transistors. MCDONNELL DOUGLAS ELECTRONICS SYSTEMS COMPANY 8. Base circuitry should be designed to drive the transistor into

High temperature bias line stabilized current sources

DOEpatents

Patterson, R.B. III.

1984-09-11

A compensation device for the base of emitter follower configured bipolar transistors becoming operable at elevated temperatures including a bipolar transistor of a geometry of not more than half the geometry of the bipolar emitter follower having its collector connected to the base of the emitter follower and its base and emitter connected together and to the emitter of the emitter follower. 1 fig.

Nutrition and Bipolar Depression.

PubMed

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.

Scrape-off-layer characterization and current-control of kink modes in HBT-EP

NASA Astrophysics Data System (ADS)

Brooks, John; Stewart, Ian; Levesque, Jeffrey; Mauel, Mike; Navratil, Gerald

2017-10-01

Scrape-off layer (SOL) currents and their paths through tokamaks are not well understood, but their control may prove crucial to the success of ITER and future fusion energy devices. We extend Columbia University's High Beta Tokamak-Extended Pulse (HBT-EP) experiment and active GPU feedback system to study the SOL and control MHD kink instabilities by actively controlling these currents. First, the radial plasma profiles and the edge structure of kink instabilities are measured with two triple probes. Second, we use active feedback control of a radially adjustable biased electrode to change the rotation and magnitude of slowly growing kink instabilities. By changing the phase between the probe's voltage and the edge instability with active feedback, we study its ability to influence and control plasma MHD structures. This work is in preparation for a planned 2018 multi-electrode SOL control upgrade. Supported by U.S. DOE Grant DE-FG02-86ER53222.

Realization of Molecular-Based Transistors.

PubMed

Richter, Shachar; Mentovich, Elad; Elnathan, Roey

2018-06-06

Molecular-based devices are widely considered as significant candidates to play a role in the next generation of "post-complementary metal-oxide-semiconductor" devices. In this context, molecular-based transistors: molecular junctions that can be electrically gated-are of particular interest as they allow new modes of operation. The properties of molecular transistors composed of a single- or multimolecule assemblies, focusing on their practicality as real-world devices, concerning industry demands and its roadmap are compared. Also, the capability of the gate electrode to modulate the molecular transistor characteristics efficiently is addressed, showing that electrical gating can be easily facilitated in single molecular transistors and that gating of transistor composed of molecular assemblies is possible if the device is formed vertically. It is concluded that while the single-molecular transistor exhibits better performance on the lab-scale, its realization faces signifacant challenges when compared to those faced by transistors composed of a multimolecule assembly. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evolvable circuit with transistor-level reconfigurability

NASA Technical Reports Server (NTRS)

Stoica, Adrian (Inventor); Salazar-Lazaro, Carlos Harold (Inventor)

2004-01-01

An evolvable circuit includes a plurality of reconfigurable switches, a plurality of transistors within a region of the circuit, the plurality of transistors having terminals, the plurality of transistors being coupled between a power source terminal and a power sink terminal so as to be capable of admitting power between the power source terminal and the power sink terminal, the plurality of transistors being coupled so that every transistor terminal to transistor terminal coupling within the region of the circuit comprises a reconfigurable switch.

Bipolar Disorder in Children

PubMed Central

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

Interband Lateral Resonant Tunneling Transistor.

DTIC Science & Technology

1994-11-14

INTERBAND LATERAL RESONANT TUNNELING TRANSISTOR 10 BACKGROUND OF THE INVENTION Field of the Invention This invention pertains to a tunneling transistor...and in 15 particular to an interband lateral resonant tunneling transistor. Description of Related Art Conventional semiconductor technologies are... interband lateral resonant tunneling transistor along the cross-section B-B of Figure 2c. Figure 4 is another preferred embodiment cross-sectional 20

Inversion channel diamond metal-oxide-semiconductor field-effect transistor with normally off characteristics.

PubMed

Matsumoto, Tsubasa; Kato, Hiromitsu; Oyama, Kazuhiro; Makino, Toshiharu; Ogura, Masahiko; Takeuchi, Daisuke; Inokuma, Takao; Tokuda, Norio; Yamasaki, Satoshi

2016-08-22

We fabricated inversion channel diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) with normally off characteristics. At present, Si MOSFETs and insulated gate bipolar transistors (IGBTs) with inversion channels are widely used because of their high controllability of electric power and high tolerance. Although a diamond semiconductor is considered to be a material with a strong potential for application in next-generation power devices, diamond MOSFETs with an inversion channel have not yet been reported. We precisely controlled the MOS interface for diamond by wet annealing and fabricated p-channel and planar-type MOSFETs with phosphorus-doped n-type body on diamond (111) substrate. The gate oxide of Al2O3 was deposited onto the n-type diamond body by atomic layer deposition at 300 °C. The drain current was controlled by the negative gate voltage, indicating that an inversion channel with a p-type character was formed at a high-quality n-type diamond body/Al2O3 interface. The maximum drain current density and the field-effect mobility of a diamond MOSFET with a gate electrode length of 5 μm were 1.6 mA/mm and 8.0 cm(2)/Vs, respectively, at room temperature.

Temperature characteristics research of SOI pressure sensor based on asymmetric base region transistor

NASA Astrophysics Data System (ADS)

Zhao, Xiaofeng; Li, Dandan; Yu, Yang; Wen, Dianzhong

2017-07-01

Based on the asymmetric base region transistor, a pressure sensor with temperature compensation circuit is proposed in this paper. The pressure sensitive structure of the proposed sensor is constructed by a C-type silicon cup and a Wheatstone bridge with four piezoresistors ({R}1, {R}2, {R}3 and {R}4) locating on the edge of a square silicon membrane. The chip was designed and fabricated on a silicon on insulator (SOI) wafer by micro electromechanical system (MEMS) technology and bipolar transistor process. When the supply voltage is 5.0 V, the corresponding temperature coefficient of the sensitivity (TCS) for the sensor before and after temperature compensation are -1862 and -1067 ppm/°C, respectively. Through varying the ratio of the base region resistances {r}1 and {r}2, the TCS for the sensor with the compensation circuit is -127 ppm/°C. It is possible to use this compensation circuit to improve the temperature characteristics of the pressure sensor. Project supported by the National Natural Science Foundation of China (No. 61471159), the Natural Science Foundation of Heilongjiang Province (No. F201433), the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province (No. 2015018), and the Special Funds for Science and Technology Innovation Talents of Harbin in China (No. 2016RAXXJ016).

High-performance vertical organic transistors.

PubMed

Kleemann, Hans; Günther, Alrun A; Leo, Karl; Lüssem, Björn

2013-11-11

Vertical organic thin-film transistors (VOTFTs) are promising devices to overcome the transconductance and cut-off frequency restrictions of horizontal organic thin-film transistors. The basic physical mechanisms of VOTFT operation, however, are not well understood and VOTFTs often require complex patterning techniques using self-assembly processes which impedes a future large-area production. In this contribution, high-performance vertical organic transistors comprising pentacene for p-type operation and C60 for n-type operation are presented. The static current-voltage behavior as well as the fundamental scaling laws of such transistors are studied, disclosing a remarkable transistor operation with a behavior limited by injection of charge carriers. The transistors are manufactured by photolithography, in contrast to other VOTFT concepts using self-assembled source electrodes. Fluorinated photoresist and solvent compounds allow for photolithographical patterning directly and strongly onto the organic materials, simplifying the fabrication protocol and making VOTFTs a prospective candidate for future high-performance applications of organic transistors. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Basic Electronics II.

ERIC Educational Resources Information Center

Willison, Neal A.; Shelton, James K.

Designed for use in basic electronics programs, this curriculum guide is comprised of 15 units of instruction. Unit titles are Review of the Nature of Matter and the P-N Junction, Rectifiers, Filters, Special Semiconductor Diodes, Bipolar-Junction Diodes, Bipolar Transistor Circuits, Transistor Amplifiers, Operational Amplifiers, Logic Devices,…

Bipolar Disorder.

ERIC Educational Resources Information Center

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…

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

PubMed

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.

Reliability of self-aligned, ledge passivated 7.5 GHz GaAs/AlGaAs HBT power amplifiers under RF bias stress at elevated temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henderson, T.S.; Ikalainen, P.K.

1995-12-31

The authors report a two-temperature RF bias stress test on nominal 1.2 W 7.5 GHz GaAs/AlGaAs HBT unit cell amplifiers. MTTF`s of 2020 and 1340 hours were obtained at Tj = 218{degrees}C and 245{degrees}C, respectively, under nominal input bias. An activation energy of 0.42 eV is estimated, consistent with published results for similar devices under DC bias stress.

Bipolar polygenic loading and bipolar spectrum features in major depressive disorder

PubMed Central

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

Control of radiative base recombination in the quantum cascade light-emitting transistor using quantum state overlap

NASA Astrophysics Data System (ADS)

Chen, Kanuo; Hsiao, Fu-Chen; Joy, Brittany; Dallesasse, John M.

2018-07-01

The concept of the quantum cascade light-emitting transistor (QCLET) is proposed by incorporating periodic stages of quantum wells and barriers in the completely depleted base-collector junction of a heterojunction bipolar transistor. The radiative band-to-band base recombination in the QCLET is shown to be controllable using the base-collector voltage bias for a given emitter-base biasing condition. A self-consistent Schrödinger-Poisson Equation model is built to validate the idea of the QCLET. A GaAs-based QCLET is designed and fabricated. Control of radiative band-to-band base recombination is observed and characterized. By changing the voltage across the quantum cascade region in the QCLET, the alignment of quantum states in the cascade region creates a tunable barrier for electrons that allows or suppresses emitter-injected electron flow from the p-type base through the quantum cascade region into the collector. The field-dependent electron barrier in the base-collector junction manipulates the effective minority carrier lifetime in the base and controls the radiative base recombination process. Under different quantum cascade region biasing conditions, the radiative base recombination is measured and analyzed.

Vertical organic transistors.

PubMed

Lüssem, Björn; Günther, Alrun; Fischer, Axel; Kasemann, Daniel; Leo, Karl

2015-11-11

Organic switching devices such as field effect transistors (OFETs) are a key element of future flexible electronic devices. So far, however, a commercial breakthrough has not been achieved because these devices usually lack in switching speed (e.g. for logic applications) and current density (e.g. for display pixel driving). The limited performance is caused by a combination of comparatively low charge carrier mobilities and the large channel length caused by the need for low-cost structuring. Vertical Organic Transistors are a novel technology that has the potential to overcome these limitations of OFETs. Vertical Organic Transistors allow to scale the channel length of organic transistors into the 100 nm regime without cost intensive structuring techniques. Several different approaches have been proposed in literature, which show high output currents, low operation voltages, and comparatively high speed even without sub-μm structuring technologies. In this review, these different approaches are compared and recent progress is highlighted.

Toward the definition of a bipolar prodrome: Dimensional predictors of bipolar spectrum disorder in at-risk youth

PubMed Central

Hafeman, Danella M.; Merranko, John; Axelson, David; Goldstein, Benjamin I.; Goldstein, Tina; Monk, Kelly; Hickey, Mary Beth; Sakolsky, Dara; Diler, Rasim; Iyengar, Satish; Brent, David; Kupfer, David; Birmaher, Boris

2016-01-01

Objective We aimed to assess dimensional symptomatic predictors of new-onset bipolar spectrum disorder in youth at familial risk of bipolar disorder (“at-risk” youth). Method Offspring aged 6–18 of parents with bipolar-I/II disorder (n=391) and offspring of community controls (n=248) were recruited without regard to non-bipolar psychopathology. At baseline, 8.4% (33/391) of offspring of bipolar parents had bipolar spectrum; 14.7% (44/299) of offspring with follow-up developed new-onset bipolar spectrum (15 with bipolar-I/II) over eight years. Scales collected at baseline and follow-up were reduced using factor analyses; factors (both at baseline and visit proximal to conversion or last contact) were then assessed as predictors of new-onset bipolar spectrum. Results Relative to community control offspring, at-risk and bipolar offspring had higher baseline levels of anxiety/depression, inattention/disinhibition, externalizing, subsydromal manic, and affective lability symptoms (p<.05). The strongest predictors of new-onset bipolar spectrum were: baseline anxiety/depression, baseline and proximal affective lability, and proximal subsyndromal manic symptoms (p<.05). While affective lability and anxiety/depression were elevated throughout follow-up in those who later developed bipolar spectrum, manic symptoms increased up to the point of conversion. A path analysis supported the hypothesized model that affective lability at baseline predicted new-onset bipolar spectrum, in part, through increased manic symptoms at the visit prior to conversion; earlier parental age of mood disorder onset also significantly increased risk of conversion (p<.001). While youth without anxiety/depression, affective lability, and mania (and with a parent with older age of mood disorder onset) had a 2% predicted chance of conversion to bipolar spectrum, those with all risk factors had a 49% predicted chance of conversion. Conclusions Dimensional measures of anxiety/depression, affective

Experimental synchronization of chaos in a large ring of mutually coupled single-transistor oscillators: phase, amplitude, and clustering effects.

PubMed

Minati, Ludovico

2014-12-01

In this paper, experimental evidence of multiple synchronization phenomena in a large (n = 30) ring of chaotic oscillators is presented. Each node consists of an elementary circuit, generating spikes of irregular amplitude and comprising one bipolar junction transistor, one capacitor, two inductors, and one biasing resistor. The nodes are mutually coupled to their neighbours via additional variable resistors. As coupling resistance is decreased, phase synchronization followed by complete synchronization is observed, and onset of synchronization is associated with partial synchronization, i.e., emergence of communities (clusters). While component tolerances affect community structure, the general synchronization properties are maintained across three prototypes and in numerical simulations. The clusters are destroyed by adding long distance connections with distant notes, but are otherwise relatively stable with respect to structural connectivity changes. The study provides evidence that several fundamental synchronization phenomena can be reliably observed in a network of elementary single-transistor oscillators, demonstrating their generative potential and opening way to potential applications of this undemanding setup in experimental modelling of the relationship between network structure, synchronization, and dynamical properties.

Experimental synchronization of chaos in a large ring of mutually coupled single-transistor oscillators: Phase, amplitude, and clustering effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minati, Ludovico, E-mail: lminati@ieee.org, E-mail: ludovico.minati@unitn.it

In this paper, experimental evidence of multiple synchronization phenomena in a large (n = 30) ring of chaotic oscillators is presented. Each node consists of an elementary circuit, generating spikes of irregular amplitude and comprising one bipolar junction transistor, one capacitor, two inductors, and one biasing resistor. The nodes are mutually coupled to their neighbours via additional variable resistors. As coupling resistance is decreased, phase synchronization followed by complete synchronization is observed, and onset of synchronization is associated with partial synchronization, i.e., emergence of communities (clusters). While component tolerances affect community structure, the general synchronization properties are maintained across three prototypes andmore » in numerical simulations. The clusters are destroyed by adding long distance connections with distant notes, but are otherwise relatively stable with respect to structural connectivity changes. The study provides evidence that several fundamental synchronization phenomena can be reliably observed in a network of elementary single-transistor oscillators, demonstrating their generative potential and opening way to potential applications of this undemanding setup in experimental modelling of the relationship between network structure, synchronization, and dynamical properties.« less

Scrape-off-layer currents during MHD activity and disruptions in HBT-EP

NASA Astrophysics Data System (ADS)

Levesque, J. P.; Desanto, S.; Battey, A.; Bialek, J.; Brooks, J. W.; Mauel, M. E.; Navratil, G. A.

2017-10-01

We report scrape-off layer (SOL) current measurements during MHD mode activity and disruptions in the HBT-EP tokamak. Currents are measured via Rogowski coils mounted on tiles in the low-field-side SOL, toroidal jumpers between otherwise-isolated vessel sections, and segmented plasma current Rogowski coils. These currents strongly depend on the plasma's major radius, mode amplitude, and mode phase. Plasma current asymmetries and SOL currents during disruptions reach 4% of the plasma current. Asymmetric toroidal currents between vessel sections rotate at tens of kHz through most of the current quench, then symmetrize once Ip reaches 30% of its pre-disruptive value. Toroidal jumper currents oscillate between co- and counter-Ip, with co-Ip being dominant on average during disruptions. Increases in local plasma current correlate with counter-Ip current in the nearest toroidal jumper. Measurements are interpreted in the context of two models that produce contrary predictions for the toroidal vessel current polarity during disruptions. Plasma current asymmetries are consistent with both models, and scale with plasma displacement toward the wall. Progress of ongoing SOL current diagnostic upgrades is also presented. Supported by U.S. DOE Grant DE-FG02-86ER53222.

Early Intervention in Bipolar Disorder.

PubMed

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

Virginia Woolf, neuroprogression, and bipolar disorder.

PubMed

Boeira, Manuela V; Berni, Gabriela de Á; Passos, Ives C; Kauer-Sant'Anna, Márcia; Kapczinski, Flávio

2017-01-01

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.

Transistor-based particle detection systems and methods

DOEpatents

Jain, Ankit; Nair, Pradeep R.; Alam, Muhammad Ashraful

2015-06-09

Transistor-based particle detection systems and methods may be configured to detect charged and non-charged particles. Such systems may include a supporting structure contacting a gate of a transistor and separating the gate from a dielectric of the transistor, and the transistor may have a near pull-in bias and a sub-threshold region bias to facilitate particle detection. The transistor may be configured to change current flow through the transistor in response to a change in stiffness of the gate caused by securing of a particle to the gate, and the transistor-based particle detection system may configured to detect the non-charged particle at least from the change in current flow.

Bipolar battery

DOEpatents

Kaun, Thomas D.

1992-01-01

A bipolar battery having a plurality of cells. The bipolar battery includes: a negative electrode; a positive electrode and a separator element disposed between the negative electrode and the positive electrode, the separator element electrically insulating the electrodes from one another; an electrolyte disposed within at least one of the negative electrode, the positive electrode and the separator element; and an electrode containment structure including a cup-like electrode holder.

High voltage power transistor development

NASA Technical Reports Server (NTRS)

Hower, P. L.

1981-01-01

Design considerations, fabrication procedures, and methods of evaluation for high-voltage power-transistor development are discussed. Technique improvements such as controlling the electric field at the surface and perserving lifetimes in the collector region which have advanced the state of the art in high-voltage transistors are discussed. These improvements can be applied directly to the development of 1200 volt, 200 ampere transistors.

Silicon on insulator self-aligned transistors

DOEpatents

McCarthy, Anthony M.

2003-11-18

A method for fabricating thin-film single-crystal silicon-on-insulator (SOI) self-aligned transistors. Standard processing of silicon substrates is used to fabricate the transistors. Physical spaces, between the source and gate, and the drain and gate, introduced by etching the polysilicon gate material, are used to provide connecting implants (bridges) which allow the transistor to perform normally. After completion of the silicon substrate processing, the silicon wafer is bonded to an insulator (glass) substrate, and the silicon substrate is removed leaving the transistors on the insulator (glass) substrate. Transistors fabricated by this method may be utilized, for example, in flat panel displays, etc.

[Emotional endophenotypes and bipolar disorder].

PubMed

Dubois, M; Azorin, J-M; Fakra, E; Adida, M; Belzeaux, R

2012-12-01

Emotion can be described as a multidimensional affective state, accompanied with physiological, cognitive and subjective manifestations. Most bipolar patients spontaneously claim they have a higher sensitivity than average, which may lead to extreme emotional reactions, even during intercrisis periods. Few studies have focused on this particular affective dimension. Moreover, the emotional reactivity is a way to raise the question of bipolar patients' vulnerability to stress during euthymic periods. The aim of this study is to examine the emotional reactivity of euthymic bipolar patients in comparison with a control group, using a test of emotional induction with short films, in order to determine whether this particular affective dimension can be a potential endophenotype. Our hypothesis is that euthymic bipolar patients have a higher emotional reactivity than controls. 20 euthymic bipolar patients and 15 healthy control subjects were recruited. The emotional reactivity was assessed using a method of emotional induction, based on viewing a set of positive, negative and neutral short films. The subjects have to appreciate the valence (pleasant, unpleasant or neutral) and the arousal (degree of emotion triggered by each film), while physiological parameters (heart rate and galvanic skin response) were measured. On average, euthymic bipolar patients report the same valence for each set of films and the same arousal to positive and negative movies as control subjects. Neutral pictures, however, were considered more moving by euthymic bipolar patients than by control subjects. Bipolar patient showed a higher heart rate than the control group, and no statistically difference was shown considering the galvanic skin response. Euthymic bipolar patients seem to present an emotional hypereactivity which occurs especially during neutral situations.These results partly corroborate other authors outcomes, using a new and more ecologic methodology through an emotional induction

Bipolar fuel cell

DOEpatents

McElroy, James F.

1989-01-01

The present invention discloses an improved fuel cell utilizing an ion transporting membrane having a catalytic anode and a catalytic cathode bonded to opposite sides of the membrane, a wet-proofed carbon sheet in contact with the cathode surface opposite that bonded to the membrane and a bipolar separator positioned in electrical contact with the carbon sheet and the anode of the adjacent fuel cell. Said bipolar separator and carbon sheet forming an oxidant flowpath, wherein the improvement comprises an electrically conductive screen between and in contact with the wet-proofed carbon sheet and the bipolar separator improving the product water removal system of the fuel cell.

Bipolar affective disorder and psychoeducation.

PubMed

Prasko, Jan; Ociskova, Marie; Kamaradova, Dana; Sedlackova, Zuzana; Cerna, Monika; Mainerova, Barbora; Sandoval, Aneta

2013-01-01

Bipolar affective disorder runs a natural course of frequent relapses and recurrences. Despite significant strides in the pharmacological treatment of bipolar disorder, most bipolar patients cannot be treated only by drugs. The limitations of using medication alone in symptomatic, relapse prevention, and satisfaction/quality of life terms have long prompted interest in wider forms of management. One of the promising way how to enhance remission seems to be combination of pharmacotherapy and psychoeducation. Studies were identified through PUBMED, Web of Science and Scopus databases as well as existing reviews. The search terms included "bipolar disorder", "psychoeducation", "psychotherapy", "psychosocial treatment", "family therapy", "individual therapy", "group therapy", and "psychoeducation". The search was performed by repeated use of the words in different combinations with no language or time limitations. This article is a review with conclusions concerned with psychoeducation in bipolar disorder. Randomized controlled trials of cognitive behavioral therapy, interpersonal and social rhythm therapy, individual, group and family psychoeducation show that these approaches augment stabilizing effect of pharmacotherapy. Patients and their families should be educated about bipolar disorder, triggers, warning signs, mood relapse, suicidal ideation, and the effectiveness of early intervention to reduce complications. Psychosocial approaches are important therapeutic strategies for reducing relapse and rehospitalization in bipolar disorder.

Lightweight bipolar storage battery

NASA Technical Reports Server (NTRS)

Rowlette, John J. (Inventor)

1992-01-01

An apparatus [10] is disclosed for a lightweight bipolar battery of the end-plate cell stack design. Current flow through a bipolar cell stack [12] is collected by a pair of copper end-plates [16a,16b] and transferred edgewise out of the battery by a pair of lightweight, low resistance copper terminals [28a,28b]. The copper terminals parallel the surface of a corresponding copper end-plate [16a,16b] to maximize battery throughput. The bipolar cell stack [12], copper end-plates [16a,16b] and copper terminals [28a,28b] are rigidly sandwiched between a pair of nonconductive rigid end-plates [20] having a lightweight fiber honeycomb core which eliminates distortion of individual plates within the bipolar cell stack due to internal pressures. Insulating foam [30] is injected into the fiber honeycomb core to reduce heat transfer into and out of the bipolar cell stack and to maintain uniform cell performance. A sealed battery enclosure [ 22] exposes a pair of terminal ends [26a,26b] for connection with an external circuit.

Single-transistor-clocked flip-flop

DOEpatents

Zhao, Peiyi; Darwish, Tarek; Bayoumi, Magdy

2005-08-30

The invention provides a low power, high performance flip-flop. The flip-flop uses only one clocked transistor. The single clocked transistor is shared by the first and second branches of the device. A pulse generator produces a clock pulse to trigger the flip-flop. In one preferred embodiment the device can be made as a static explicit pulsed flip-flop which employs only two clocked transistors.

Evaluation of semiconductor devices for Electric and Hybrid Vehicle (EHV) ac-drive applications, volume 2

NASA Technical Reports Server (NTRS)

Lee, F. C.; Chen, D. Y.; Jovanic, M.; Hopkins, D. C.

1985-01-01

Test data of switching times characterization of bipolar transistors, of field effect transistor's switching times on-resistance and characterization, comparative data of field effect transistors, and test data of field effect transistor's parallel operation characterization are given. Data is given in the form of graphs.

Six years of evidence-based adult dissection tonsillectomy with ultrasonic scalpel, bipolar electrocautery, bipolar radiofrequency or 'cold steel' dissection.

PubMed

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.

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

ERIC Educational Resources Information Center

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…

The Integration and Applications of Organic Thin Film Transistors and Ferroelectric Polymers

NASA Astrophysics Data System (ADS)

Hsu, Yu-Jen

Organic thin film transistors and ferroelectric polymer (polyvinylidene difluoride) sheet material are integrated to form various sensors for stress/strain, acoustic wave, and Infrared (heat) sensing applications. Different from silicon-based transistors, organic thin film transistors can be fabricated and processed in room-temperature and integrated with a variety of substrates. On the other hand, polyvinylidene difluoride (PVDF) exhibits ferroelectric properties that are highly useful for sensor applications. The wide frequency bandwidth (0.001 Hz to 10 GHz), vast dynamic range (100n to 10M psi), and high elastic compliance (up to 3 percent) make PVDF a more suitable candidate over ceramic piezoelectric materials for thin and flexible sensor applications. However, the low Curie temperature may have impeded its integration with silicon technology. Organic thin film transistors, however, do not have the limitation of processing temperature, hence can serve as transimpedance amplifiers to convert the charge signal generated by PVDF into current signal that are more measurable and less affected by any downstream parasitics. Piezoelectric sensors are useful for a range of applications, but passive arrays suffer from crosstalk and signal attenuation which have complicated the development of array-based PVDF sensors. We have used organic field effect transistors, which are compatible with the low Curie temperature of a flexible piezoelectric polymer,PVDF, to monolithically fabricate transimpedance amplifiers directly on the sensor surface and convert the piezoelectric charge signal into a current signal which can be detected even in the presence of parasitic capacitances. The device couples the voltage generated by the PVDF film under strain into the gate of the organic thin film transistors (OFET) using an arrangement that allows the full piezoelectric voltage to couple to the channel, while also increasing the charge retention time. A bipolar detector is created by

Complementary spin transistor using a quantum well channel.

PubMed

Park, Youn Ho; Choi, Jun Woo; Kim, Hyung-Jun; Chang, Joonyeon; Han, Suk Hee; Choi, Heon-Jin; Koo, Hyun Cheol

2017-04-20

In order to utilize the spin field effect transistor in logic applications, the development of two types of complementary transistors, which play roles of the n- and p-type conventional charge transistors, is an essential prerequisite. In this research, we demonstrate complementary spin transistors consisting of two types of devices, namely parallel and antiparallel spin transistors using InAs based quantum well channels and exchange-biased ferromagnetic electrodes. In these spin transistors, the magnetization directions of the source and drain electrodes are parallel or antiparallel, respectively, depending on the exchange bias field direction. Using this scheme, we also realize a complementary logic operation purely with spin transistors controlled by the gate voltage, without any additional n- or p-channel transistor.

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

PubMed Central

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

Cognitive vulnerability to bipolar disorder in offspring of parents with bipolar disorder.

PubMed

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.

[Lithium and anticonvulsants in bipolar depression].

PubMed

Samalin, L; Nourry, A; Llorca, P-M

2011-12-01

For decades, lithium and anticonvulsants have been widely used in the treatment of bipolar disorder. Their efficacy in the treatment of mania is recognized. These drugs have been initially evaluated in old and methodologically heterogeneous studies. Their efficacy in bipolar depression has not always been confirmed in more recent and methodologically more reliable studies. Thus, lithium's efficacy as monotherapy was challenged by the study of Young (2008) that showed a lack of efficacy compared with placebo in the treatment of bipolar depression. In two recent meta-analyses, valproate has shown a modest efficacy in the treatment of bipolar depression. As for lithium, valproate appeared to have a larger antimanic effect for acute phase and prophylaxis of bipolar disorder. In contrast, lamotrigine is more effective on the depressive pole of bipolar disorder with better evidence for the prevention of depressive recurrences. The guidelines include these recent studies and recommend lamotrigine as a first-line treatment of bipolar depression and for maintenance treatment. Because of more discordant data concerning lithium and valproate, these two drugs are placed either as first or as second line treatment of bipolar depression. The different safety/efficacy ratios of mood stabilizers underlie the complementarity and the importance of combination between them, or with some second-generation antipsychotics, in the treatment of patients with bipolar disorder. Copyright © 2011 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

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

PubMed

Rajewska-Rager, Aleksandra; Sibilski, Piotr; Lepczyńska, Natalia

2015-01-01

In recent years much attention has been given to determine risk factors for suicide among adults with bipolar disorder. Such studies concerning children and youths, which would also take into account the specificity of the developmental age, are still too few. The ability to identify risk factors for children and youths with mood disorders, as well as the possibility to monitor them, is an essential element in preventing suicidal behaviours. Previous studies have clearly indicated that in the group of patients with an early onset of the bipolar disorder the occurrence of suicidal thoughts and intentions were significantly increased. Identifying the risk of suicide is hindered further by the complexity of the phenomenon, which is a compound interaction of various factors: biological, environmental, sociological, psychological and clinical. This is especially true with young adults suffering from mental illness and presenting a number of other psychopathological symptoms. The following paper introduces and reviews the results of current studies, which analysed the risk factors for suicide among children and youths with bipolar spectrum or already diagnosed with bipolar disorder. For this purpose we conducted the overview of recent years literature available in PubMed/MEDLINE database, including the following search criteria: early onset bipolar disorder, bipolar disorder in children and young people, the spectrum of bipolar disorder, and suicidal ideation, suicidal intent, suicide.

Threat Sensitivity in Bipolar Disorder

PubMed Central

Muhtadie, Luma; Johnson, Sheri L.

2015-01-01

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

Current sensing circuit

NASA Technical Reports Server (NTRS)

Franke, Ralph J. (Inventor)

1996-01-01

A current sensing circuit is described in which a pair of bipolar transistors are arranged with a pair of field effect transistors such that the field effect transistors absorb most of the supply voltage associated with a load.

Silicon device performance measurements to support temperature range enhancement

NASA Technical Reports Server (NTRS)

Johnson, R. Wayne; Askew, Ray; Bromstead, James; Weir, Bennett

1991-01-01

The results of the NPN bipolar transistor (BJT) (2N6023) breakdown voltage measurements were analyzed. Switching measurements were made on the NPN BJT, the insulated gate bipolar transistor (IGBT) (TA9796) and the N-channel metal oxide semiconductor field effect transistor (MOSFET) (RFH75N05E). Efforts were also made to build a H-bridge inverter. Also discussed are the plans that have been made to do life testing on the devices, to build an inductive switching test circuit and to build a dc/dc switched mode converter.

Bipolar Disorder and Early Affective Trauma.

PubMed

de Codt, Aloise; Monhonval, Pauline; Bongaerts, Xavier; Belkacemi, Ikram; Tecco, Juan Martin

2016-09-01

Bipolar disorder is a chronic psychiatric disease with a high prevalence and is a major psychosocial and medical burden. The exact etiological pathways of bipolar disorder are not fully understood. Genetic factors are known to play an important role in the etiology of bipolar disorder. However, high rates of discordance among identical twins and a growing body of evidence that environmental factors such as early stress can influence the onset and course of psychiatric diseases underline the importance of additional etiological mechanisms of bipolar disorders. There has been little investigation about early trauma in bipolar disorder. The aim of this study was to review the literature on the association between early traumatic interactions like child neglect, mistreatment, abuse or early parental separation and the occurrence of bipolar disorder in adulthood or impact on the course of the disease. Studies investigating associations between child neglect, mistreatment, abuse or early parental separation and occurrence of bipolar disorder in adulthood or impact on the course of the disease were searched in the Pubmed database. More than 700 articles were sorted independently by two of the authors using predefined criteria. Only research articles, reviews and meta-analyses were selected for this review. 53 articles met the inclusion criteria. To date, four systematic reviews partially addressed our research question. Early trauma is more frequently found in the past of bipolar patients than in the general population. Studies support a harmful effect of childhood trauma on the course of bipolar disease, with more anxious, depressive or psychotic symptoms, an early age of onset and a worse prognosis. Early trauma is more often found in the past of bipolar adult patients than the general population and studies support a harmful effect of childhood trauma on the course of bipolar disease, with more anxious, depressive or psychotic symptoms, an early age of onset and a

TRANSISTOR HIGH VOLTAGE POWER SUPPLY

DOEpatents

Driver, G.E.

1958-07-15

High voltage, direct current power supplies are described for use with battery powered nuclear detection equipment. The particular advantages of the power supply described, are increased efficiency and reduced size and welght brought about by the use of transistors in the circuit. An important feature resides tn the employment of a pair of transistors in an alternatefiring oscillator circuit having a coupling transformer and other circuit components which are used for interconnecting the various electrodes of the transistors.

Photosensitive graphene transistors.

PubMed

Li, Jinhua; Niu, Liyong; Zheng, Zijian; Yan, Feng

2014-08-20

High performance photodetectors play important roles in the development of innovative technologies in many fields, including medicine, display and imaging, military, optical communication, environment monitoring, security check, scientific research and industrial processing control. Graphene, the most fascinating two-dimensional material, has demonstrated promising applications in various types of photodetectors from terahertz to ultraviolet, due to its ultrahigh carrier mobility and light absorption in broad wavelength range. Graphene field effect transistors are recognized as a type of excellent transducers for photodetection thanks to the inherent amplification function of the transistors, the feasibility of miniaturization and the unique properties of graphene. In this review, we will introduce the applications of graphene transistors as photodetectors in different wavelength ranges including terahertz, infrared, visible, and ultraviolet, focusing on the device design, physics and photosensitive performance. Since the device properties are closely related to the quality of graphene, the devices based on graphene prepared with different methods will be addressed separately with a view to demonstrating more clearly their advantages and shortcomings in practical applications. It is expected that highly sensitive photodetectors based on graphene transistors will find important applications in many emerging areas especially flexible, wearable, printable or transparent electronics and high frequency communications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

2017 Bipolar Plate Workshop Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kopasz, John P.; Benjamin, Thomas G.; Schenck, Deanna

The Bipolar Plate (BP) Workshop was held at USCAR1 in Southfield, Michigan on February 14, 2017 and included 63 participants from industry, government agencies, universities, and national laboratories with expertise in the relevant fields. The objective of the workshop was to identify research and development (R&D) needs, in particular early-stage R&D, for bipolar plates for polymer electrolyte membrane (PEM) fuel cells for transportation applications. The focus of the workshop was on materials, manufacturing, and design aspects of bipolar plates with the goal of meeting DOE’s 2020 bipolar plate targets. Of special interest was the cost target of ≤$3/kW for themore » bipolar plate.« less

Electro-magnetic physics studies at RHIC: Neutral pion production, direct photon HBT, photon elliptic flow in gold-gold collisions at sqrt(s_NN) = 200 GeV and the Muon Telescope Detector simulation

NASA Astrophysics Data System (ADS)

Lin, Guoji

Electro-magnetic (E&M) probes such as direct photons and muons (mu) are important tools to study the properties of the extremely hot and dense matter created in heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC). In this thesis, several topics of E&M physics will be addressed, including neutral pion (pi0) production, direct photon HBT, and photon elliptic flow (v2) in Au+Au collisions at sNN = 200 GeV. A discussion on the simulation study of the new Muon Telescope Detector (MTD) will also be presented. The pi0 production is a fundamental measurement of hadron production and prerequisite for the background study of direct photons. Neutral pions are reconstructed using the photons detected by the STAR Barrel Electro-magnetic Calorimeter (BEMC) and the Time Projection Chamber (TPC). Spectra of pi 0 are measured at transverse momentum 1 < pT < 12 GeV/c near mid-rapidity (0 < eta < 0.8) in 200 GeV Au+Au collisions. The spectra and nuclear modification factors RCP and RAA are compared to earlier pi+/- and pi0 results. Direct photon Hanbury-Brown and Twiss (HBT) correlations can reveal information of the system size throughout the whole collision. A first attempt of direct photon HBT study at RHIC in 200 GeV Au+Au collisions is done using photons detected by the STAR BEMC and TPC. All unknown correlation at small Qinv is observed, whose magnitude is much larger than the expected HBT signal, and possible causes of the correlation will be discussed. Direct photon elliptic flow (v2) at intermediate to high pT is sensitive to the source of direct photon production. Results of inclusive photon v2 in 200 GeV Au+Au collisions are presented. The v2 of pi0 decay photons is calculated from the previously published pi results. The comparison between inclusive and decay photon v 2 indicates that direct photon v2 is small. A new large-area Muon Telescope Detector at mid-rapidity at RHIC is proposed and under investigation, using the Long-strip Multi-Gap Resistive Plate

A neuron-astrocyte transistor-like model for neuromorphic dressed neurons.

PubMed

Valenza, G; Pioggia, G; Armato, A; Ferro, M; Scilingo, E P; De Rossi, D

2011-09-01

Experimental evidences on the role of the synaptic glia as an active partner together with the bold synapse in neuronal signaling and dynamics of neural tissue strongly suggest to investigate on a more realistic neuron-glia model for better understanding human brain processing. Among the glial cells, the astrocytes play a crucial role in the tripartite synapsis, i.e. the dressed neuron. A well-known two-way astrocyte-neuron interaction can be found in the literature, completely revising the purely supportive role for the glia. The aim of this study is to provide a computationally efficient model for neuron-glia interaction. The neuron-glia interactions were simulated by implementing the Li-Rinzel model for an astrocyte and the Izhikevich model for a neuron. Assuming the dressed neuron dynamics similar to the nonlinear input-output characteristics of a bipolar junction transistor, we derived our computationally efficient model. This model may represent the fundamental computational unit for the development of real-time artificial neuron-glia networks opening new perspectives in pattern recognition systems and in brain neurophysiology. Copyright © 2011 Elsevier Ltd. All rights reserved.

Bipolar mixed features - Results from the comparative effectiveness for bipolar disorder (Bipolar CHOICE) study.

PubMed

Tohen, Mauricio; Gold, Alexandra K; Sylvia, Louisa G; Montana, Rebecca E; McElroy, Susan L; Thase, Michael E; Rabideau, Dustin J; Nierenberg, Andrew A; Reilly-Harrington, Noreen A; Friedman, Edward S; Shelton, Richard C; Bowden, Charles L; Singh, Vivek; Deckersbach, Thilo; Ketter, Terence A; Calabrese, Joseph R; Bobo, William V; McInnis, Melvin G

2017-08-01

DSM-5 changed the criteria from DSM-IV for mixed features in mood disorder episodes to include non-overlapping symptoms of depression and hypomania/mania. It is unknown if, by changing these criteria, the same group would qualify for mixed features. We assessed how those meeting DSM-5 criteria for mixed features compare to those meeting DSM-IV criteria. We analyzed data from 482 adult bipolar patients in Bipolar CHOICE, a randomized comparative effectiveness trial. Bipolar diagnoses were confirmed through the MINI International Neuropsychiatric Interview (MINI). Presence and severity of mood symptoms were collected with the Bipolar Inventory of Symptoms Scale (BISS) and linked to DSM-5 and DSM-IV mixed features criteria. Baseline demographics and clinical variables were compared between mood episode groups using ANOVA for continuous variables and chi-square tests for categorical variables. At baseline, the frequency of DSM-IV mixed episodes diagnoses obtained with the MINI was 17% and with the BISS was 20%. Using DSM-5 criteria, 9% of participants met criteria for hypomania/mania with mixed features and 12% met criteria for a depressive episode with mixed features. Symptom severity was also associated with increased mixed features with a high rate of mixed features in patients with mania/hypomania (63.8%) relative to those with depression (8.0%). Data on mixed features were collected at baseline only and thus do not reflect potential patterns in mixed features within this sample across the study duration. The DSM-5 narrower, non-overlapping definition of mixed episodes resulted in fewer patients who met mixed criteria compared to DSM-IV. Copyright © 2017. Published by Elsevier B.V.

Brief Report: A Family Risk Study Exploring Bipolar Spectrum Problems and Cognitive Biases in Adolescent Children of Bipolar Parents

ERIC Educational Resources Information Center

Espie, Jonathan; Jones, Steven H.; Vance, Yvonne H.; Tai, Sara J.

2012-01-01

Children of parents with bipolar disorder are at increased risk of bipolar spectrum diagnoses. This cross-sectional study explores cognitive factors in the prediction of vulnerability to bipolar disorder. Adolescents at high-risk (with a parent with bipolar disorder; n = 23) and age and gender matched adolescents (n = 24) were recruited. Parent…

Boron nitride housing cools transistors

NASA Technical Reports Server (NTRS)

1965-01-01

Boron nitride ceramic heat sink cools transistors in r-f transmitter and receiver circuits. Heat dissipated by the transistor is conducted by the boron nitride housing to the metal chassis on which it is mounted.

Histopathologic changes after bipolar resection of the prostate: depth of penetration of bipolar thermal injury.

PubMed

Maddox, Michael; Pareek, Gyan; Al Ekish, Shadi; Thavaseelan, Simone; Mehta, Akanksha; Mangray, Shamlal; Haleblian, George

2012-10-01

While the power needed to initiate bipolar vaporization is higher than conventional monopolar resection, the energy needed to maintain bipolar vaporization is significantly lower and may result in less thermal tissue injury. This may have implications for hemostasis, scarring, and perioperative morbidity. The objective of this study is to assess histopathologic changes in prostatic tissue after bipolar transurethral vaporization of the prostate. Male patients older than 40 years with a diagnosis of benign prostatic hyperplasia (BPH) who elected to undergo bipolar transurethral vaporization of the prostate were included in this study. Patients were excluded if they had a previous transurethral resection of the prostate (TURP) or prostate radiation therapy. An Olympus button vaporization electrode was used to vaporize prostate tissue. A loop electrode was then used to obtain a deep resection specimen. The vaporized and loop resection surfaces were inked and sent for pathologic analysis to determine the presence of gross histologic changes and the depth of penetration of the bipolar vaporization current. A total of 12 men underwent bipolar TURP at standard settings of 290 W cutting and 145 W coagulation current. Mean patient age was 70±10.2 years (range 56-88 years). Mean surgical time was 48.7±20.2 minutes (range 30-89 min). Mean depth of thermal injury was 2.4±0.84 mm (range 0.3-3.5 mm). Histopathologic evaluation demonstrated thermal injury in all specimens, but no gross char was encountered. In bipolar systems, resection takes place at much lower peak voltages and temperatures compared with monopolar systems. Theoretically, this leads to less collateral thermal damage and tissue char. Our tissue study illustrates that the button vaporization electrode achieves a much larger depth of penetration than previous studies of bipolar TURP. This may be because thermal injury represents a gradual continuum of histologic changes.

The resonant body transistor.

PubMed

Weinstein, Dana; Bhave, Sunil A

2010-04-14

This paper introduces the resonant body transistor (RBT), a silicon-based dielectrically transduced nanoelectromechanical (NEM) resonator embedding a sense transistor directly into the resonator body. Combining the benefits of FET sensing with the frequency scaling capabilities and high quality factors (Q) of internal dielectrically transduced bar resonators, the resonant body transistor achieves >10 GHz frequencies and can be integrated into a standard CMOS process for on-chip clock generation, high-Q microwave circuits, fundamental quantum-state preparation and observation, and high-sensitivity measurements. An 11.7 GHz bulk-mode RBT is demonstrated with a quality factor Q of 1830, marking the highest frequency acoustic resonance measured to date on a silicon wafer.

Bipolar plates for PEM fuel cells

NASA Astrophysics Data System (ADS)

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.

Complementary junction heterostructure field-effect transistor

DOEpatents

Baca, Albert G.; Drummond, Timothy J.; Robertson, Perry J.; Zipperian, Thomas E.

1995-01-01

A complimentary pair of compound semiconductor junction heterostructure field-effect transistors and a method for their manufacture are disclosed. The p-channel junction heterostructure field-effect transistor uses a strained layer to split the degeneracy of the valence band for a greatly improved hole mobility and speed. The n-channel device is formed by a compatible process after removing the strained layer. In this manner, both types of transistors may be independently optimized. Ion implantation is used to form the transistor active and isolation regions for both types of complimentary devices. The invention has uses for the development of low power, high-speed digital integrated circuits.

Complementary junction heterostructure field-effect transistor

DOEpatents

Baca, A.G.; Drummond, T.J.; Robertson, P.J.; Zipperian, T.E.

1995-12-26

A complimentary pair of compound semiconductor junction heterostructure field-effect transistors and a method for their manufacture are disclosed. The p-channel junction heterostructure field-effect transistor uses a strained layer to split the degeneracy of the valence band for a greatly improved hole mobility and speed. The n-channel device is formed by a compatible process after removing the strained layer. In this manner, both types of transistors may be independently optimized. Ion implantation is used to form the transistor active and isolation regions for both types of complimentary devices. The invention has uses for the development of low power, high-speed digital integrated circuits. 10 figs.

Temperament and personality in bipolar II disorder.

PubMed

Fletcher, Kathryn; Parker, Gordon; Barrett, Melissa; Synnott, Howe; McCraw, Stacey

2012-02-01

There is limited research examining temperament and personality in bipolar II disorder. We sought to determine any over-represented temperament and personality features in bipolar II disorder compared to other affective groups. Scores on a self-report measure of temperament and personality were examined in a sample of 443 participants diagnosed with unipolar, bipolar I and bipolar II disorder. After controlling for age, gender, age of depression onset and current depression severity, those with bipolar II disorder were characterized by higher irritability, anxious worrying, self-criticism and interpersonal sensitivity scores, and with lower social avoidance scores compared to unipolar participants. No differences were found between bipolar sub-types on any temperament and personality sub-scales. Limitations included the lack of a control group, a relatively small sample of bipolar I participants, and with the cross-sectional design disallowing conclusions regarding premorbid personality traits as opposed to illness 'scarring' effects. Further research should seek to clarify whether certain temperament and personality styles are over-represented in bipolar II disorder. Any over-represented characteristics may assist with diagnostic differentiation from phenomenologically similar conditions and lead to more appropriate clinical management. Copyright © 2011 Elsevier B.V. All rights reserved.

Assessment of Phospohrene Field Effect Transistors

DTIC Science & Technology

2018-01-28

electronics industry. To this end, transistor test structures would initially be fabricated on phosphorene exfoliated from black phosphorus and, later, on...34Phosphorene FETs-Promising Transistors Based on a few Layers of Phosphorus Atoms," Nanjing Electronic Devices Institute, Nanjing, China, Jul. 2015...OH, Nov. 2015. J.C. M. Hwang, "Phosphorene Transistors-Transient or Lasting Electronics ?" Workshop Frontier Electronics , San Juan, PR, Dec. 2015

Oxide Based Transistor for Flexible Displays

DTIC Science & Technology

2014-09-15

thin film transistors (TFTs) for next generation display technologies. A detailed and comprehensive study was carried out to ascertain the process...Box 12211 Research Triangle Park, NC 27709-2211 Thin film transistors , flexible electronics, RF sputtering, Transparent amorphous oxide semiconductors...NC A&T and RTI, International investigated In free GaSnZnO (GSZO) material system, as the active channel in thin film transistors (TFTs) for next

Electronic monitoring in bipolar disorder.

PubMed

Faurholt-Jepsen, Maria

2018-03-01

Major reasons for the insufficient effects of current treatment options in bipolar disorder include delayed intervention for prodromal depressive and manic symptoms and decreased adherence to psychopharmacological treatment. The reliance on subjective information and clinical evaluations when diagnosing and assessing the severity of depressive and manic symptoms calls for less biased and more objective markers. By using electronic devices, fine-grained data on complex psychopathological aspects of bipolar disorder can be evaluated unobtrusively over the long term. Moreover, electronic data could possibly represent candidate markers of diagnosis and illness activity in bipolar disorder and allow for early and individualized intervention for prodromal symptoms outside clinical settings. 
The present dissertation concerns the use of electronic monitoring as a marker and treatment intervention in bipolar disorder and investigated the scientific literature and body of evidence within the area, which includes ten original study reports and two systematic reviews, one of which included a meta-analysis, conducted by the author of the dissertation. 
Taken together, the literature presented in this dissertation illustrates that 1) smartphone-based electronic self-monitoring of mood seems to reflect clinically assessed depressive and manic symptoms and enables the long-term characterization of mood

instability in bipolar disorder; 2) preliminary results suggest that smartphone-based automatically generated data (e.g. the number of text messages sent/day; the number of incoming and outgoing calls/day; the number of changes in cell tower IDs/day; and voice features) seem to reflect clinically assessed depressive and manic symptoms in bipolar disorder; 3) smartphone-based electronic self-monitoring had no effects on the severity of depressive and manic symptoms in bipolar disorder, according to a randomized controlled trial; and 4) electronic monitoring of psychomotor

[Bipolar disorder in the elderly].

PubMed

Monczor, Myriam

2010-01-01

Bipolar disorder is a frequent disorder in the elderly, with a prevalence of 0.1 a 0.4%; a 10% of bipolar patients have mania onset after 50 years old. It has in ageing a more heterogeneous clinical presentation. The manic episodes are less severe, mixed depression is common, as well as confusion and cognitive impairment. A first manic episode in ageing can be secondary to medical illness. Treatment for bipolar disorder in ageing is similar to treatment for young patients. The differences are due to pharmacocinetic changes because of the age, with the comorbidity and with the etiology, if it is a secondary mania. Lithium can be the first choice for treating mania in patients with antecedent of good response and have tolerance to adverse effects, but because of its toxicity and secondary effects other possibilities may be considered: divalproate, cabamazepine, antipsychotics. There are some little studies that show lamotrigine efficacy in bipolar depression in elderly. We need more specific studies about bipolar disorder treatment in aging.

Prediction of transition from common adolescent bipolar experiences to bipolar disorder: 10-year study.

PubMed

Tijssen, Marijn J A; van Os, Jim; Wittchen, Hans-Ulrich; Lieb, Roselind; Beesdo, Katja; Mengelers, Ron; Wichers, Marieke

2010-02-01

Although (hypo)manic symptoms are common in adolescence, transition to adult bipolar disorder is infrequent. To examine whether the risk of transition to bipolar disorder is conditional on the extent of persistence of subthreshold affective phenotypes. In a 10-year prospective community cohort study of 3021 adolescents and young adults, the association between persistence of affective symptoms over 3 years and the 10-year clinical outcomes of incident DSM-IV (hypo)manic episodes and incident use of mental healthcare was assessed. Transition to clinical outcome was associated with persistence of symptoms in a dose-dependent manner. Around 30-40% of clinical outcomes could be traced to prior persistence of affective symptoms. In a substantial proportion of individuals, onset of clinical bipolar disorder may be seen as the poor outcome of a developmentally common and usually transitory non-clinical bipolar phenotype.

Life expectancy in bipolar disorder.

PubMed

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

2015-08-01

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. Using nationwide registers of all inpatient and outpatient contacts to all psychiatric hospitals in Denmark from 1970 to 2012 we calculated remaining life expectancies for values of age 15, 25, 35 ⃛ 75 years among all individuals alive in year 2000. For the typical male or female patient aged 25 to 45 years, the remaining life expectancy was decreased by 12.0-8.7 years and 10.6-8.3 years, respectively. The ratio between 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. Life expectancy in bipolar disorder is decreased substantially, but less so than previously reported. Patients start losing life-years during early and mid-adulthood. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

"Is it menopause or bipolar?": a qualitative study of the experience of menopause for women with bipolar disorder.

PubMed

Perich, Tania; Ussher, Jane; Parton, Chloe

2017-11-16

Menopause can be a time of change for women and may be marked by disturbances in mood. For women living with a mental illness, such as bipolar disorder, little is known about how they experience mood changes during menopause. This study aimed to explore how women with bipolar disorder constructed mood changes during menopause and how this impacted on treatment decisions. Semi-structured interviews were undertaken with fifteen women who reported they had been diagnosed with bipolar disorder. Data was analysed using thematic analysis guided by a social constructionist framework. Themes identified included 'Constructions of mood change: menopause or bipolar disorder?',' Life events, bipolar disorder and menopause coming together'; 'Treatment choices for mood change during menopause'. The accounts suggested that women related to the experience of mood changes during menopause through the lens of their existing framework of bipolar disorder, with implications for understanding of self and treatment choices.

Reconfigurable Complementary Logic Circuits with Ambipolar Organic Transistors

PubMed Central

Yoo, Hocheon; Ghittorelli, Matteo; Smits, Edsger C. P.; Gelinck, Gerwin H.; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

2016-01-01

Ambipolar organic electronics offer great potential for simple and low-cost fabrication of complementary logic circuits on large-area and mechanically flexible substrates. Ambipolar transistors are ideal candidates for the simple and low-cost development of complementary logic circuits since they can operate as n-type and p-type transistors. Nevertheless, the experimental demonstration of ambipolar organic complementary circuits is limited to inverters. The control of the transistor polarity is crucial for proper circuit operation. Novel gating techniques enable to control the transistor polarity but result in dramatically reduced performances. Here we show high-performance non-planar ambipolar organic transistors with electrical control of the polarity and orders of magnitude higher performances with respect to state-of-art split-gate ambipolar transistors. Electrically reconfigurable complementary logic gates based on ambipolar organic transistors are experimentally demonstrated, thus opening up new opportunities for ambipolar organic complementary electronics. PMID:27762321

Reconfigurable Complementary Logic Circuits with Ambipolar Organic Transistors.

PubMed

Yoo, Hocheon; Ghittorelli, Matteo; Smits, Edsger C P; Gelinck, Gerwin H; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

2016-10-20

Ambipolar organic electronics offer great potential for simple and low-cost fabrication of complementary logic circuits on large-area and mechanically flexible substrates. Ambipolar transistors are ideal candidates for the simple and low-cost development of complementary logic circuits since they can operate as n-type and p-type transistors. Nevertheless, the experimental demonstration of ambipolar organic complementary circuits is limited to inverters. The control of the transistor polarity is crucial for proper circuit operation. Novel gating techniques enable to control the transistor polarity but result in dramatically reduced performances. Here we show high-performance non-planar ambipolar organic transistors with electrical control of the polarity and orders of magnitude higher performances with respect to state-of-art split-gate ambipolar transistors. Electrically reconfigurable complementary logic gates based on ambipolar organic transistors are experimentally demonstrated, thus opening up new opportunities for ambipolar organic complementary electronics.

Ultra-high gain diffusion-driven organic transistor

PubMed Central

Torricelli, Fabrizio; Colalongo, Luigi; Raiteri, Daniele; Kovács-Vajna, Zsolt Miklós; Cantatore, Eugenio

2016-01-01

Emerging large-area technologies based on organic transistors are enabling the fabrication of low-cost flexible circuits, smart sensors and biomedical devices. High-gain transistors are essential for the development of large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show a new organic field-effect transistor architecture with a gain larger than 700. This is the highest gain ever reported for organic field-effect transistors. In the proposed organic field-effect transistor, the charge injection and extraction at the metal–semiconductor contacts are driven by the charge diffusion. The ideal conditions of ohmic contacts with negligible contact resistance and flat current saturation are demonstrated. The approach is general and can be extended to any thin-film technology opening unprecedented opportunities for the development of high-performance flexible electronics. PMID:26829567

Ultra-high gain diffusion-driven organic transistor.

PubMed

Torricelli, Fabrizio; Colalongo, Luigi; Raiteri, Daniele; Kovács-Vajna, Zsolt Miklós; Cantatore, Eugenio

2016-02-01

Emerging large-area technologies based on organic transistors are enabling the fabrication of low-cost flexible circuits, smart sensors and biomedical devices. High-gain transistors are essential for the development of large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show a new organic field-effect transistor architecture with a gain larger than 700. This is the highest gain ever reported for organic field-effect transistors. In the proposed organic field-effect transistor, the charge injection and extraction at the metal-semiconductor contacts are driven by the charge diffusion. The ideal conditions of ohmic contacts with negligible contact resistance and flat current saturation are demonstrated. The approach is general and can be extended to any thin-film technology opening unprecedented opportunities for the development of high-performance flexible electronics.

Ultra-high gain diffusion-driven organic transistor

NASA Astrophysics Data System (ADS)

Torricelli, Fabrizio; Colalongo, Luigi; Raiteri, Daniele; Kovács-Vajna, Zsolt Miklós; Cantatore, Eugenio

2016-02-01

Emerging large-area technologies based on organic transistors are enabling the fabrication of low-cost flexible circuits, smart sensors and biomedical devices. High-gain transistors are essential for the development of large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show a new organic field-effect transistor architecture with a gain larger than 700. This is the highest gain ever reported for organic field-effect transistors. In the proposed organic field-effect transistor, the charge injection and extraction at the metal-semiconductor contacts are driven by the charge diffusion. The ideal conditions of ohmic contacts with negligible contact resistance and flat current saturation are demonstrated. The approach is general and can be extended to any thin-film technology opening unprecedented opportunities for the development of high-performance flexible electronics.

High-Performance Vertical Organic Electrochemical Transistors.

PubMed

Donahue, Mary J; Williamson, Adam; Strakosas, Xenofon; Friedlein, Jacob T; McLeod, Robert R; Gleskova, Helena; Malliaras, George G

2018-02-01

Organic electrochemical transistors (OECTs) are promising transducers for biointerfacing due to their high transconductance, biocompatibility, and availability in a variety of form factors. Most OECTs reported to date, however, utilize rather large channels, limiting the transistor performance and resulting in a low transistor density. This is typically a consequence of limitations associated with traditional fabrication methods and with 2D substrates. Here, the fabrication and characterization of OECTs with vertically stacked contacts, which overcome these limitations, is reported. The resulting vertical transistors exhibit a reduced footprint, increased intrinsic transconductance of up to 57 mS, and a geometry-normalized transconductance of 814 S m -1 . The fabrication process is straightforward and compatible with sensitive organic materials, and allows exceptional control over the transistor channel length. This novel 3D fabrication method is particularly suited for applications where high density is needed, such as in implantable devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modeling suicide in bipolar disorders.

PubMed

Malhi, Gin S; Outhred, Tim; Das, Pritha; Morris, Grace; Hamilton, Amber; Mannie, Zola

2018-02-19

Suicide is a multicausal human behavior, with devastating and immensely distressing consequences. Its prevalence is estimated to be 20-30 times greater in patients with bipolar disorders than in the general population. The burden of suicide and its high prevalence in bipolar disorders make it imperative that our current understanding be improved to facilitate prediction of suicide and its prevention. In this review, we provide a new perspective on the process of suicide in bipolar disorder, in the form of a novel integrated model that is derived from extant knowledge and recent evidence. A literature search of articles on suicide in bipolar disorder was conducted in recognized databases such as Scopus, PubMed, and PsycINFO using the keywords "suicide", "suicide in bipolar disorders", "suicide process", "suicide risk", "neurobiology of suicide" and "suicide models". Bibliographies of identified articles were further scrutinized for papers and book chapters of relevance. Risk factors for suicide in bipolar disorders are well described, and provide a basis for a framework of epigenetic mechanisms, moderated by neurobiological substrates, neurocognitive functioning, and social inferences within the environment. Relevant models and theories include the diathesis-stress model, the bipolar model of suicide and the ideation-to-action models, the interpersonal theory of suicide, the integrated motivational-volitional model, and the three-step theory. Together, these models provide a basis for the generation of an integrated model that illuminates the suicidal process, from ideation to action. Suicide is complex, and it is evident that a multidimensional and integrated approach is required to reduce its prevalence. The proposed model exposes and provides access to components of the suicide process that are potentially measurable and may serve as novel and specific therapeutic targets for interventions in the context of bipolar disorder. Thus, this model is useful not only

High transconductance organic electrochemical transistors

NASA Astrophysics Data System (ADS)

Khodagholy, Dion; Rivnay, Jonathan; Sessolo, Michele; Gurfinkel, Moshe; Leleux, Pierre; Jimison, Leslie H.; Stavrinidou, Eleni; Herve, Thierry; Sanaur, Sébastien; Owens, Róisín M.; Malliaras, George G.

2013-07-01

The development of transistors with high gain is essential for applications ranging from switching elements and drivers to transducers for chemical and biological sensing. Organic transistors have become well-established based on their distinct advantages, including ease of fabrication, synthetic freedom for chemical functionalization, and the ability to take on unique form factors. These devices, however, are largely viewed as belonging to the low-end of the performance spectrum. Here we present organic electrochemical transistors with a transconductance in the mS range, outperforming transistors from both traditional and emerging semiconductors. The transconductance of these devices remains fairly constant from DC up to a frequency of the order of 1 kHz, a value determined by the process of ion transport between the electrolyte and the channel. These devices, which continue to work even after being crumpled, are predicted to be highly relevant as transducers in biosensing applications.

High transconductance organic electrochemical transistors

PubMed Central

Khodagholy, Dion; Rivnay, Jonathan; Sessolo, Michele; Gurfinkel, Moshe; Leleux, Pierre; Jimison, Leslie H.; Stavrinidou, Eleni; Herve, Thierry; Sanaur, Sébastien; Owens, Róisín M.; Malliaras, George G.

2013-01-01

The development of transistors with high gain is essential for applications ranging from switching elements and drivers to transducers for chemical and biological sensing. Organic transistors have become well-established based on their distinct advantages, including ease of fabrication, synthetic freedom for chemical functionalization, and the ability to take on unique form factors. These devices, however, are largely viewed as belonging to the low-end of the performance spectrum. Here we present organic electrochemical transistors with a transconductance in the mS range, outperforming transistors from both traditional and emerging semiconductors. The transconductance of these devices remains fairly constant from DC up to a frequency of the order of 1 kHz, a value determined by the process of ion transport between the electrolyte and the channel. These devices, which continue to work even after being crumpled, are predicted to be highly relevant as transducers in biosensing applications. PMID:23851620

Recent progress in photoactive organic field-effect transistors.

PubMed

Wakayama, Yutaka; Hayakawa, Ryoma; Seo, Hoon-Seok

2014-04-01

Recent progress in photoactive organic field-effect transistors (OFETs) is reviewed. Photoactive OFETs are divided into light-emitting (LE) and light-receiving (LR) OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These are categorized according to their functionalities: phototransistors, non-volatile optical memories, and photochromism-based transistors. For both, various device configurations are introduced: thin-film based transistors for practical applications, single-crystalline transistors to investigate fundamental physics, nanowires, multi-layers, and vertical transistors based on new concepts.

Bipolar Medications and Weight Gain

MedlinePlus

... Answers from Daniel K. Hall-Flavin, M.D. Bipolar disorder can be treated with a number of medications. ... Also, how well the medication works to treat bipolar disorder symptoms differs among individuals. Because of this, finding ...

High-Speed, high-power, switching transistor

NASA Technical Reports Server (NTRS)

Carnahan, D.; Ohu, C. K.; Hower, P. L.

1979-01-01

Silicon transistor rate for 200 angstroms at 400 to 600 volts combines switching speed of transistors with ruggedness, power capacity of thyristor. Transistor introduces unique combination of increased power-handling capability, unusally low saturation and switching losses, and submicrosecond switching speeds. Potential applications include high power switching regulators, linear amplifiers, chopper controls for high frequency electrical vehicle drives, VLF transmitters, RF induction heaters, kitchen cooking ranges, and electronic scalpels for medical surgery.

Suprasensory phenomena in those with a bipolar disorder.

PubMed

Parker, Gordon; Paterson, Amelia; Romano, Mia; Granville Smith, Isabelle

2018-03-01

To increase awareness of the sensory changes experienced during hypo/manic and depressive states by those with a bipolar disorder and determine if the prevalence of such features is similar across differing bipolar sub-types. We interviewed 66 patients who acknowledged sensory changes during hypo/manic states. They were allocated to bipolar I, bipolar II and soft bipolar diagnostic categories and the prevalence of 10 differing sensory changes was quantified during hypo/manic and depressive phases. Bipolar I patients were just as likely, if not more likely, to report suprasensory changes which typically involved enhancement of senses during hypo/manic phases and muting or blunting during depressive phases. The high prevalence of changes in intuition, empathy, appreciation of danger and predictive capacities suggests that these are more part of the intrinsic bipolar mood domain states and not necessarily suprasensory, while changes in primary senses of smell, taste, vision, touch and hearing appear to more commonly define the suprasensory domain. It is important for clinicians and patients with a bipolar disorder to be aware of non-psychotic, suprasensory phenomena. Identification of such features may aid diagnosis and also explain the recognised increased creativity in those with a bipolar condition.

The bipolarity of light and dark: A review on Bipolar Disorder and circadian cycles.

PubMed

Abreu, T; Bragança, M

2015-10-01

Bipolar Disorder is characterized by episodes running the full mood spectrum, from mania to depression. Between mood episodes, residual symptoms remain, as sleep alterations, circadian cycle disturbances, emotional deregulation, cognitive impairment and increased risk for comorbidities. The present review intends to reflect about the most recent and relevant information concerning the biunivocal relation between bipolar disorder and circadian cycles. It was conducted a literature search on PubMed database using the search terms "bipolar", "circadian", "melatonin", "cortisol", "body temperature", "Clock gene", "Bmal1 gene", "Per gene", "Cry gene", "GSK3β", "chronotype", "light therapy", "dark therapy", "sleep deprivation", "lithum" and "agomelatine". Search results were manually reviewed, and pertinent studies were selected for inclusion as appropriate. Several studies support the relationship between bipolar disorder and circadian cycles, discussing alterations in melatonin, body temperature and cortisol rhythms; disruption of sleep/wake cycle; variations of clock genes; and chronotype. Some therapeutics for bipolar disorder directed to the circadian cycles disturbances are also discussed, including lithium carbonate, agomelatine, light therapy, dark therapy, sleep deprivation and interpersonal and social rhythm therapy. This review provides a summary of an extensive research for the relevant literature on this theme, not a patient-wise meta-analysis. In the future, it is essential to achieve a better understanding of the relation between bipolar disorder and the circadian system. It is required to establish new treatment protocols, combining psychotherapy, therapies targeting the circadian rhythms and the latest drugs, in order to reduce the risk of relapse and improve affective behaviour. Copyright © 2015 Elsevier B.V. All rights reserved.

Bipolar spectrum disorders. New perspectives.

PubMed Central

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

2002-01-01

OBJECTIVE: To review new perspectives on diagnosis, clinical features, epidemiology, and treatment of bipolar II and related disorders. QUALITY OF EVIDENCE: Articles were identified by searching MEDLINE and ClinPSYCH from January 1994 to August 2001 using the key words bipolar disorder, type II or 2; hypomania; spectrum; or variants. Reference lists from articles were reviewed. Overall, the quality of evidence was not high; we found no randomized controlled trials that specifically addressed bipolar II or bipolar spectrum disorders (BSDs). MAIN MESSAGE: Characterized by elevated mood cycling with depression, BSDs appear to be much more common than previously thought, affecting up to 30% of primary care patients presenting with anxiety or depressive symptoms. Hypomania, the defining feature of bipolar II disorder, is often not detected. Collateral information, semistructured interviews, and brief screening instruments could improve diagnosis. Antidepressants should be used with caution. The newer mood stabilizers or combinations of mood stabilizers might be the treatments of choice in the future. CONCLUSION: Family physicians, as primary providers of mental health care, should try to recognize and treat BSDs more frequently. These disorders are becoming increasingly common in primary care populations. PMID:12053634

Universal power transistor base drive control unit

DOEpatents

Gale, Allan R.; Gritter, David J.

1988-01-01

A saturation condition regulator system for a power transistor which achieves the regulation objectives of a Baker clamp but without dumping excess base drive current into the transistor output circuit. The base drive current of the transistor is sensed and used through an active feedback circuit to produce an error signal which modulates the base drive current through a linearly operating FET. The collector base voltage of the power transistor is independently monitored to develop a second error signal which is also used to regulate base drive current. The current-sensitive circuit operates as a limiter. In addition, a fail-safe timing circuit is disclosed which automatically resets to a turn OFF condition in the event the transistor does not turn ON within a predetermined time after the input signal transition.

Universal power transistor base drive control unit

DOEpatents

Gale, A.R.; Gritter, D.J.

1988-06-07

A saturation condition regulator system for a power transistor is disclosed which achieves the regulation objectives of a Baker clamp but without dumping excess base drive current into the transistor output circuit. The base drive current of the transistor is sensed and used through an active feedback circuit to produce an error signal which modulates the base drive current through a linearly operating FET. The collector base voltage of the power transistor is independently monitored to develop a second error signal which is also used to regulate base drive current. The current-sensitive circuit operates as a limiter. In addition, a fail-safe timing circuit is disclosed which automatically resets to a turn OFF condition in the event the transistor does not turn ON within a predetermined time after the input signal transition. 2 figs.

The Effects of Low Dose-Rate Ionizing Radiation on the Shapes of Transients in the LM124 Operational Amplifier

NASA Technical Reports Server (NTRS)

Buchner, Stephen; McMorrow, Dale; Roche, Nicholas; Dusseau, Laurent; Pease, Ron L.

2008-01-01

Shapes of single event transients (SETs) in a linear bipolar circuit (LM124) change with exposure to total ionizing dose (TID) radiation. SETs shape changes are a direct consequence of TID-induced degradation of bipolar transistor gain. A reduction in transistor gain causes a reduction in the drive current of the current sources in the circuit, and it is the lower drive current that most affects the shapes of large amplitude SETs.

Development of Process Technologies for High-Performance MOS-Based SiC Power Switching Devices

DTIC Science & Technology

2007-08-01

investigated are insulated-gate bipolar transistors ( IGBTs ) in 4H-SiC. The IGBT combines the best aspects of MOS and bipolar power transistors... IGBTs can be thought of as a fusion of a MOSFET and a BJT. The MOSFET provides a high input impedance while the BJT provides conductivity modulation of...region due to conductivity modulation from the forward-biased BJT. The IGBT is structurally identical to a MOSFET, except that the substrate doping

Intraoperative dislocation of the trial bipolar cup into the pelvis during bipolar hip arthroplasty - A case report.

PubMed

Miyake, Takahito; Kanda, Akio; Morohashi, Itaru; Obayashi, Osamu; Mogami, Atsuhiko; Kaneko, Kazuo

2017-06-01

Bipolar hip arthroplasty is a good option for treating femoral neck fractures, although some contraindications have been indicated. We report a case of intraoperative dislocation of the trial bipolar cup into the pelvis during bipolar hip arthroplasty. A 74-year-old woman underwent bipolar hip arthroplasty for a femoral neck fracture (AO31-B2). She was placed in a lateral decubitus position, and a direct lateral approach was used. During intraoperative trial reduction, the trial bipolar cup became disengaged and dislocated into the anterior space of hip joint. Several attempts to retrieve it failed. The permanent femoral component was inserted, and the wound was closed. The patient was repositioned supine to allow an ilioinguinal approach, and the component was easily removed. She had an uneventful, good recovery. Several cases of intraoperative dislocation of the femoral trial head during total hip arthroplasty have been reported, this is the first report of dislocation of a bipolar trial cup. A previous report described difficulty retrieving a trial cup. We easily removed our trial cup using another approach. It is vital to plan systematically for this frustrating complication.

Hafnium transistor design for neural interfacing.

PubMed

Parent, David W; Basham, Eric J

2008-01-01

A design methodology is presented that uses the EKV model and the g(m)/I(D) biasing technique to design hafnium oxide field effect transistors that are suitable for neural recording circuitry. The DC gain of a common source amplifier is correlated to the structural properties of a Field Effect Transistor (FET) and a Metal Insulator Semiconductor (MIS) capacitor. This approach allows a transistor designer to use a design flow that starts with simple and intuitive 1-D equations for gain that can be verified in 1-D MIS capacitor TCAD simulations, before final TCAD process verification of transistor properties. The DC gain of a common source amplifier is optimized by using fast 1-D simulations and using slower, complex 2-D simulations only for verification. The 1-D equations are used to show that the increased dielectric constant of hafnium oxide allows a higher DC gain for a given oxide thickness. An additional benefit is that the MIS capacitor can be employed to test additional performance parameters important to an open gate transistor such as dielectric stability and ionic penetration.

Thyroid Functions and Bipolar Affective Disorder

PubMed Central

Chakrabarti, Subho

2011-01-01

Accumulating evidence suggests that hypothalamo-pituitary-thyroid (HPT) axis dysfunction is relevant to the pathophysiology and clinical course of bipolar affective disorder. Hypothyroidism, either overt or more commonly subclinical, appears to the commonest abnormality found in bipolar disorder. The prevalence of thyroid dysfunction is also likely to be greater among patients with rapid cycling and other refractory forms of the disorder. Lithium-treatment has potent antithyroid effects and can induce hypothyroidism or exacerbate a preexisting hypothyroid state. Even minor perturbations of the HPT axis may affect the outcome of bipolar disorder, necessitating careful monitoring of thyroid functions of patients on treatment. Supplementation with high dose thyroxine can be considered in some patients with treatment-refractory bipolar disorder. Neurotransmitter, neuroimaging, and genetic studies have begun to provide clues, which could lead to an improved understanding of the thyroid-bipolar disorder connection, and more optimal ways of managing this potentially disabling condition. PMID:21808723

Nickel hydrogen bipolar battery electrode design

NASA Technical Reports Server (NTRS)

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.

Fundamentals of bipolar high-frequency surgery.

PubMed

Reidenbach, H D

1993-04-01

In endoscopic surgery a very precise surgical dissection technique and an efficient hemostasis are of decisive importance. The bipolar technique may be regarded as a method which satisfies both requirements, especially regarding a high safety standard in application. In this context the biophysical and technical fundamentals of this method, which have been known in principle for a long time, are described with regard to the special demands of a newly developed field of modern surgery. After classification of this method into a general and a quasi-bipolar mode, various technological solutions of specific bipolar probes, in a strict and in a generalized sense, are characterized in terms of indication. Experimental results obtained with different bipolar instruments and probes are given. The application of modern microprocessor-controlled high-frequency surgery equipment and, wherever necessary, the integration of additional ancillary technology into the specialized bipolar instruments may result in most useful and efficient tools of a key technology in endoscopic surgery.

Suicide in bipolar disorder: a review.

PubMed

Latalova, Klara; Kamaradova, Dana; Prasko, Jan

2014-06-01

Suicide is a leading cause of death in patients with bipolar disorder. Risk factors and prevention of suicide in this illness are the focus of considerable current research. MEDLINE data base was searched for the key words "bipolar disorder" with "suicide", "lithium" with "suicide", "anticonvulsants" with "bipolar disorder", and "anticonvulsants" with "bipolar disorder" and with "suicide". No language or time constraints were applied. The lists of references were searched manually to find additional articles. It is estimated that 25% to 50% of patients with bipolar disorder will attempt suicide at least once over their lifetime, and that 8% to 19% will complete suicide. Mortality rates from cardiovascular diseases are elevated in bipolar disorder. Risk factors for suicide include younger age of onset of the illness, history of past suicidal behavior, family history of suicide acts, comorbid borderline personality disorder and substance use disorders, and hopelessness. The warning signs calling for immediate action include the patients threatening to harm themselves, or looking for ways to kill themselves (seeking access to pills or weapons), or the patient talking or writing about death. Robust evidence supports the effects of lithium treatment in reducing suicidal attempts and completions in bipolar disorder. The evidence for antisuicidal effects of anticonvulsants is weaker. Nevertheless, valproate and other anticonvulsants are frequently prescribed as mood stabilizers. There have been controversial suggestions that this treatment may elevate the risk of suicide, but the data supporting this are not convincing. Psychoeducation can reduce the number of suicide attempts and completions. Suicide in bipolar disorder is a major public health problem. Recent research has expanded our knowledge of risk factors and warning signs. Nevertheless, it appears that the introduction of lithium treatment in the 1970s was the most recent important breakthrough in the prevention

Impairment in emotion perception from body movements in individuals with bipolar I and bipolar II disorder is associated with functional capacity.

PubMed

Vaskinn, Anja; Lagerberg, Trine Vik; Bjella, Thomas D; Simonsen, Carmen; Andreassen, Ole A; Ueland, Torill; Sundet, Kjetil

2017-12-01

Individuals with bipolar disorder present with moderate impairments in social cognition during the euthymic state. The impairment extends to theory of mind and to the perception of emotion in faces and voices, but it is unclear if emotion perception from body movements is affected. The main aim of this study was to examine if participants with bipolar disorder perform worse than healthy control participants on a task using point-light displays of human full figures moving in a manner indicative of a basic emotion (angry, happy, sad, fearful, neutral/no emotion). A secondary research question was whether diagnostic subtypes (bipolar I, bipolar II) and history of psychosis impacted on this type of emotion perception. Finally, symptomatic, neurocognitive, and functional correlates of emotion perception from body movements were investigated. Fifty-three individuals with bipolar I (n = 29) or bipolar II (n = 24) disorder, and 84 healthy control participants were assessed for emotion perception from body movements. The bipolar group also underwent clinical, cognitive, and functional assessment. Research questions were analyzed using analyses of variance and bivariate correlations. The bipolar disorder group differed significantly from healthy control participants for emotion perception from body movements (Cohen's d = 0.40). Analyses of variance yielded no effects of sex, diagnostic subtype (bipolar I, bipolar II), or history of psychosis. There was an effect of emotion, indicating that some emotions are easier to recognize. The lack of a significant group × emotion interaction effect points, however, to this being so regardless of the presence of bipolar disorder. Performance was unrelated to manic and depressive symptom load but showed significant associations with neurocognition and functional capacity. Individuals with bipolar disorder had a small but significant impairment in the ability to perceive emotions from body movement. The impairment was global, i

The relationship between borderline personality disorder and bipolar disorder

PubMed Central

Zimmerman, Mark; Morgan, Theresa A.

2013-01-01

It is clinically important to recognize both bipolar disorder and borderline personality disorder (BPD) in patients seeking treatment for depression, and it is important to distinguish between the two. Research considering whether BPD should be considered part of a bipolar spectrum reaches differing conclusions. We reviewed the most studied question on the relationship between BPD and bipolar disorder: their diagnostic concordance. Across studies, approximately 10% of patients with BPD had bipolar I disorder and another 10% had bipolar II disorder. Likewise, approximately 20% of bipolar II patients were diagnosed with BPD, though only 10% of bipolar I patients were diagnosed with BPD. While the comorbidity rates are substantial, each disorder is nontheless diagnosed in the absence of the other in the vast majority of cases (80% to 90%). In studies examining personality disorders broadly, other personality disorders were more commonly diagnosed in bipolar patients than was BPD. Likewise, the converse is also true: other axis I disorders such as major depression, substance abuse, and post-traumatic stress disorder are also more commonly diagnosed in patients with BPD than is bipolar disorder. These findings challenge the notion that BPD is part of the bipolar spectrum. PMID:24174890

Understanding and Control of Bipolar Self-Doping in Copper Nitride

PubMed Central

Fioretti, Angela N.; Schwartz, Craig P.; Vinson, John; Nordlund, Dennis; Prendergast, David; Tamboli, Adele C.; Caskey, Christopher M.; Tuomisto, Filip; Linez, Florence; Christensen, Steven T.; Toberer, Eric S.; Lany, Stephan; Zakutayev, Andriy

2016-01-01

Semiconductor materials that can be doped both n-type and p-type are desirable for diode-based applications and transistor technology. Copper nitride (Cu3N) is a metastable semiconductor with a solar-relevant bandgap that has been reported to exhibit bipolar doping behavior. However, deeper understanding and better control of the mechanism behind this behavior in Cu3N is currently lacking in the literature. In this work, we use combinatorial growth with a temperature gradient to demonstrate both conduction types of phase-pure, sputter-deposited Cu3N thin films. Room temperature Hall effect and Seebeck effect measurements show n-type Cu3N with an electron density of 1017 cm−3 for low growth temperature (≈ 35 °C) and p-type with a hole density between 1015 cm−3 and 1016 cm−3 for elevated growth temperatures (50 °C to 120 °C). Mobility for both types of Cu3N was ≈ 0.1 cm2/Vs to 1 cm2/V. Additionally, temperature-dependent Hall effect measurements indicate that ionized defects are an important scattering mechanism in p-type films. By combining X-ray absorption spectroscopy and first-principles defect theory, we determined that VCu defects form preferentially in p-type Cu3N while Cui defects form preferentially in n-type Cu3N; suggesting that Cu3N is a compensated semiconductor with conductivity type resulting from a balance between donor and acceptor defects. Based on these theoretical and experimental results, we propose a kinetic defect formation mechanism for bipolar doping in Cu3N, that is also supported by positron annihilation experiments. Overall, the results of this work highlight the importance of kinetic processes in the defect physics of metastable materials, and provide a framework that can be applied when considering the properties of such materials in general. PMID:27746508

Understanding and control of bipolar self-doping in copper nitride

NASA Astrophysics Data System (ADS)

Fioretti, Angela N.; Schwartz, Craig P.; Vinson, John; Nordlund, Dennis; Prendergast, David; Tamboli, Adele C.; Caskey, Christopher M.; Tuomisto, Filip; Linez, Florence; Christensen, Steven T.; Toberer, Eric S.; Lany, Stephan; Zakutayev, Andriy

2016-05-01

Semiconductor materials that can be doped both n-type and p-type are desirable for diode-based applications and transistor technology. Copper nitride (Cu3N) is a metastable semiconductor with a solar-relevant bandgap that has been reported to exhibit bipolar doping behavior. However, deeper understanding and better control of the mechanism behind this behavior in Cu3N is currently lacking in the literature. In this work, we use combinatorial growth with a temperature gradient to demonstrate both conduction types of phase-pure, sputter-deposited Cu3N thin films. Room temperature Hall effect and Seebeck effect measurements show n-type Cu3N with 1017 electrons/cm3 for low growth temperature (≈35 °C) and p-type with 1015 holes/cm3-1016 holes/cm3 for elevated growth temperatures (50 °C-120 °C). Mobility for both types of Cu3N was ≈0.1 cm2/Vs-1 cm2/Vs. Additionally, temperature-dependent Hall effect measurements indicate that ionized defects are an important scattering mechanism in p-type films. By combining X-ray absorption spectroscopy and first-principles defect theory, we determined that VCu defects form preferentially in p-type Cu3N, while Cui defects form preferentially in n-type Cu3N, suggesting that Cu3N is a compensated semiconductor with conductivity type resulting from a balance between donor and acceptor defects. Based on these theoretical and experimental results, we propose a kinetic defect formation mechanism for bipolar doping in Cu3N that is also supported by positron annihilation experiments. Overall, the results of this work highlight the importance of kinetic processes in the defect physics of metastable materials and provide a framework that can be applied when considering the properties of such materials in general.

Understanding and Control of Bipolar Self-Doping in Copper Nitride

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fioretti, Angela N.; Schwartz, Craig P.; Vinson, John

2016-05-14

Semiconductor materials that can be doped both n-type and p-type are desirable for diode-based applications and transistor technology. Copper nitride (Cu3N) is a metastable semiconductor with a solar-relevant bandgap that has been reported to exhibit bipolar doping behavior. However, deeper understanding and better control of the mechanism behind this behavior in Cu3N is currently lacking in the literature. In this work, we use combinatorial growth with a temperature gradient to demonstrate both conduction types of phase-pure, sputter-deposited Cu3N thin films. Room temperature Hall effect and Seebeck effect measurements show n-type Cu3N with 1017 electrons/cm3 for low growth temperature (approximately 35more » degrees C) and p-type with 1015 holes/cm3-1016 holes/cm3 for elevated growth temperatures (50 degrees C-120 degrees C). Mobility for both types of Cu3N was approximately 0.1 cm2/Vs-1 cm2/Vs. Additionally, temperature-dependent Hall effect measurements indicate that ionized defects are an important scattering mechanism in p-type films. By combining X-ray absorption spectroscopy and first-principles defect theory, we determined that VCu defects form preferentially in p-type Cu3N, while Cui defects form preferentially in n-type Cu3N, suggesting that Cu3N is a compensated semiconductor with conductivity type resulting from a balance between donor and acceptor defects. Based on these theoretical and experimental results, we propose a kinetic defectformation mechanism for bipolar doping in Cu3N that is also supported by positron annihilation experiments. Overall, the results of this work highlight the importance of kinetic processes in the defect physics of metastable materials and provide a framework that can be applied when considering the properties of such materials in general.« less

The clinical trajectory of emerging bipolar disorder among the high-risk offspring of bipolar parents: current understanding and future considerations.

PubMed

Duffy, A; Vandeleur, C; Heffer, N; Preisig, M

2017-11-22

Relatively little is known about the onset of bipolar disorder, yet the early illness course is already associated with significant morbidity and mortality. Therefore, characterizing the bipolar illness trajectory is key to risk prediction and early intervention advancement. In this narrative review, we discuss key findings from prospective longitudinal studies of the high-risk offspring of bipolar parents and related meta-analyses that inform us about the clinical trajectory of emerging bipolar disorder. Challenges such as phenotypic and etiologic heterogeneity and the non-specificity of early symptoms and syndromes are highlighted. Implications of the findings for both research and clinical practice are discussed. Bipolar disorder in young people at familial risk does not typically onset with a hypomanic or manic episode. Rather the first activated episode is often preceded by years of impairing psychopathological states that vary over development and across emerging bipolar subtype. Taking heterogeneity into account and adopting a more comprehensive approach to diagnosis seems necessary to advance earlier identification and our understanding of the onset of bipolar disorder.

Planar-Processed Polymer Transistors.

PubMed

Xu, Yong; Sun, Huabin; Shin, Eul-Yong; Lin, Yen-Fu; Li, Wenwu; Noh, Yong-Young

2016-10-01

Planar-processed polymer transistors are proposed where the effective charge injection and the split unipolar charge transport are all on the top surface of the polymer film, showing ideal device characteristics with unparalleled performance. This technique provides a great solution to the problem of fabrication limitations, the ambiguous operating principle, and the performance improvements in practical applications of conjugated-polymer transistors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Neurobiology of Bipolar Disorder: An Integrated Approach

PubMed Central

2016-01-01

Bipolar disorder is a heterogeneous condition with myriad clinical manifestations and many comorbidities leading to severe disabilities in the biopsychosocial realm. The objective of this review article was to underline recent advances in knowledge regarding the neurobiology of bipolar disorder. A further aim was to draw attention to new therapeutic targets in the treatment of bipolar disorder. To accomplish these goals, an electronic search was undertaken of the PubMed database in August 2015 of literature published during the last 10 years on the pathophysiology of bipolar disorder. A wide-ranging evaluation of the existing work was done with search terms such as "mood disorders and biology," "bipolar disorder and HPA axis," "bipolar disorder and cytokines," "mood disorders and circadian rhythm," "bipolar disorder and oxidative stress," etc. This endeavor showed that bipolar disorder is a diverse condition sharing neurobiological mechanisms with major depressive disorder and psychotic spectrum disorders. There is convincing evidence of crosstalk between different biological systems that act in a deleterious manner causing expression of the disease in genetically predisposed individuals. Inflammatory mediators act in concert with oxidative stress to dysregulate hormonal, metabolic, and circadian homeostasis in precipitating and perpetuating the illness. Stress, whether biologically or psychologically mediated, is responsible for the initiation and progression of the diathesis. Bipolar spectrum disorders have a strong genetic component; severe life stresses acting through various paths cause the illness phenotype. PMID:26865997

Graphene-based flexible and stretchable thin film transistors.

PubMed

Yan, Chao; Cho, Jeong Ho; Ahn, Jong-Hyun

2012-08-21

Graphene has been attracting wide attention owing to its superb electronic, thermal and mechanical properties. These properties allow great applications in the next generation of optoelectronics, where flexibility and stretchability are essential. In this context, the recent development of graphene growth/transfer and its applications in field-effect transistors are involved. In particular, we provide a detailed review on the state-of-the-art of graphene-based flexible and stretchable thin film transistors. We address the principles of fabricating high-speed graphene analog transistors and the key issues of producing an array of graphene-based transistors on flexible and stretchable substrates. It provides a platform for future work to focus on understanding and realizing high-performance graphene-based transistors.

VALPROATE, BIPOLAR DISORDER AND POLYCYSTIC OVARIAN SYNDROME.

PubMed

Okanović, Milana; Zivanović, Olga

2016-01-01

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

Distinctions of bipolar disorder symptoms in adolescence.

PubMed

Gudiene, Devika; Leskauskas, Darius; Markeviciūte, Aurelija; Klimavicius, Dalius; Adomaitiene, Virginija

2008-01-01

Bipolar disorder in adolescents is a serious mental illness with problematic diagnosis that adversely affects social, academic, emotional, and family functioning. The objective of this study was to analyze features of premorbid and clinical symptoms, comorbidity, and course of bipolar disorder in adolescence. Data for analysis were collected from all case histories (N=6) of 14-18-year-old patients, hospitalized with diagnosis of bipolar disorder in the Unit of Children's and Adolescents' Psychiatry, Department of Psychiatry, Hospital of Kaunas University of Medicine, during the period from 2000 to 2005. Analysis of bipolar disorder course showed that five patients previously had been diagnosed with an episode of depression. The most frequent symptoms typical to bipolar disorder were disobedience and impulsive behavior, rapid changes of mood. The most common premorbid features were frequent changes of mood, being active in communication, hyperactive behavior. Adolescence-onset bipolar disorder was frequently comorbid with emotionally instable personality disorder, borderline type. Findings of the study confirm the notion that oppositional or impulsive behavior, rapid changes of mood without any reason, dysphoric mood and euphoric mood episodes with increased energy were cardinal symptoms of bipolar disorder with mania in adolescents. Most frequent premorbid features of these patients were quite similar to attention-deficit/hyperactivity disorder making differential diagnosis problematic.

Pregnancy and bipolar disorder: a systematic review.

PubMed

Sharma, Verinder; Pope, Carley J

2012-11-01

The postpartum period is generally considered a time of heightened vulnerability to bipolar disorder; however, there is controversy about the effect of pregnancy on the course of bipolar disorder. This article reviews the literature on the relationship between pregnancy and bipolar disorder and suggests areas for future research. Three electronic databases, MEDLINE (1966-2010), PsycINFO (1840-2010), and EMBASE, were searched on April 30, 2010, using the following keywords: pregnancy, bipolar disorder, manic depressive disorder, suicide, hospitalization, pharmacotherapy, and psychotherapy. The reference lists of articles identified were also searched. All relevant papers published in English were included. A total of 70 articles were identified and included in the review. Evidence from studies using nonclinical samples, some retrospective studies, and studies on psychiatric hospitalization rates is suggestive of a positive effect of pregnancy on bipolar disorder; however, recent studies conducted at tertiary care facilities have reported high rates of recurrence following discontinuation of mood stabilizers. Understanding the relationship between pregnancy and bipolar disorder has implications for perinatal treatment and etiologic understanding of the disorder. Research is urgently needed to estimate the prevalence of bipolar disorder during pregnancy, using both clinical and nonclinical samples. © Copyright 2012 Physicians Postgraduate Press, Inc.

Coaxial inverted geometry transistor having buried emitter

NASA Technical Reports Server (NTRS)

Hruby, R. J.; Cress, S. B.; Dunn, W. R. (Inventor)

1973-01-01

The invention relates to an inverted geometry transistor wherein the emitter is buried within the substrate. The transistor can be fabricated as a part of a monolithic integrated circuit and is particularly suited for use in applications where it is desired to employ low actuating voltages. The transistor may employ the same doping levels in the collector and emitter, so these connections can be reversed.

Highly Crumpled All-Carbon Transistors for Brain Activity Recording.

PubMed

Yang, Long; Zhao, Yan; Xu, Wenjing; Shi, Enzheng; Wei, Wenjing; Li, Xinming; Cao, Anyuan; Cao, Yanping; Fang, Ying

2017-01-11

Neural probes based on graphene field-effect transistors have been demonstrated. Yet, the minimum detectable signal of graphene transistor-based probes is inversely proportional to the square root of the active graphene area. This fundamentally limits the scaling of graphene transistor-based neural probes for improved spatial resolution in brain activity recording. Here, we address this challenge using highly crumpled all-carbon transistors formed by compressing down to 16% of its initial area. All-carbon transistors, chemically synthesized by seamless integration of graphene channels and hybrid graphene/carbon nanotube electrodes, maintained structural integrity and stable electronic properties under large mechanical deformation, whereas stress-induced cracking and junction failure occurred in conventional graphene/metal transistors. Flexible, highly crumpled all-carbon transistors were further verified for in vivo recording of brain activity in rats. These results highlight the importance of advanced material and device design concepts to make improvements in neuroelectronics.

Bipolar battery construction

NASA Technical Reports Server (NTRS)

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

1981-01-01

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

Integrated Neurobiology of Bipolar Disorder

PubMed Central

Maletic, Vladimir; Raison, Charles

2014-01-01

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

Transport of carbon ion test particles and hydrogen recycling in the plasma of the Columbia tokamak HBT'' (High Beta Tokamak)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jian-Hua.

Carbon impurity ion transport is studied in the Columbia High Beta Tokamak (HBT), using a carbon tipped probe which is inserted into the plasma (n{sub e} {approx} 1 {minus} 5 {times} 10{sup 14} (cm{sup {minus}3}), T{sub e} {approx} 4 {minus} 10 (eV), B{sub t} {approx} 0.2 {minus} 0.4(T)). Carbon impurity light, mainly the strong lines of C{sub II}(4267A, emitted by the C{sup +} ions) and C{sub III} (4647A, emitted by the C{sup ++} ions), is formed by the ablation or sputtering of plasma ions and by the discharge of the carbon probe itself. The diffusion transport of the carbon ionsmore » is modeled by measuring the space-and-time dependent spectral light emission of the carbon ions with a collimated optical beam and photomultiplier. The point of emission can be observed in such a way as to sample regions along and transverse to the toroidal magnetic field. The carbon ion diffusion coefficients are obtained by fitting the data to a diffusion transport model. It is found that the diffusion of the carbon ions is classical'' and is controlled by the high collisionality of the HBT plasma; the diffusion is a two-dimensional problem and the expected dependence on the charge of the impurity ion is observed. The measurement of the spatial distribution of the H{sub {alpha}} emissivity was obtained by inverting the light signals from a 4-channel polychromator, the data were used to calculate the minor-radial influx, the density, and the recycling time of neutral hydrogen atoms or molecules. The calculation shows that the particle recycling time {tau}{sub p} is comparable with the plasma energy confinement time {tau}{sub E}; therefore, the recycling of the hot plasma ions with the cold neutrals from the walls is one of the main mechanisms for loss of plasma energy.« less

Epidemiology, neurobiology and pharmacological interventions related to suicide deaths and suicide attempts in bipolar disorder: Part I of a report of the International Society for Bipolar Disorders Task Force on Suicide in Bipolar Disorder.

PubMed

Schaffer, Ayal; Isometsä, Erkki T; Tondo, Leonardo; Moreno, Doris H; Sinyor, Mark; Kessing, Lars Vedel; Turecki, Gustavo; Weizman, Abraham; Azorin, Jean-Michel; Ha, Kyooseob; Reis, Catherine; Cassidy, Frederick; Goldstein, Tina; Rihmer, Zoltán; Beautrais, Annette; Chou, Yuan-Hwa; Diazgranados, Nancy; Levitt, Anthony J; Zarate, Carlos A; Yatham, Lakshmi

2015-09-01

Bipolar disorder is associated with elevated risk of suicide attempts and deaths. Key aims of the International Society for Bipolar Disorders Task Force on Suicide included examining the extant literature on epidemiology, neurobiology and pharmacotherapy related to suicide attempts and deaths in bipolar disorder. Systematic review of studies from 1 January 1980 to 30 May 2014 examining suicide attempts or deaths in bipolar disorder, with a specific focus on the incidence and characterization of suicide attempts and deaths, genetic and non-genetic biological studies and pharmacotherapy studies specific to bipolar disorder. We conducted pooled, weighted analyses of suicide rates. The pooled suicide rate in bipolar disorder is 164 per 100,000 person-years (95% confidence interval = [5, 324]). Sex-specific data on suicide rates identified a 1.7:1 ratio in men compared to women. People with bipolar disorder account for 3.4-14% of all suicide deaths, with self-poisoning and hanging being the most common methods. Epidemiological studies report that 23-26% of people with bipolar disorder attempt suicide, with higher rates in clinical samples. There are numerous genetic associations with suicide attempts and deaths in bipolar disorder, but few replication studies. Data on treatment with lithium or anticonvulsants are strongly suggestive for prevention of suicide attempts and deaths, but additional data are required before relative anti-suicide effects can be confirmed. There were limited data on potential anti-suicide effects of treatment with antipsychotics or antidepressants. This analysis identified a lower estimated suicide rate in bipolar disorder than what was previously published. Understanding the overall risk of suicide deaths and attempts, and the most common methods, are important building blocks to greater awareness and improved interventions for suicide prevention in bipolar disorder. Replication of genetic findings and stronger prospective data on

Epidemiology, neurobiology and pharmacological interventions related to suicide deaths and suicide attempts in bipolar disorder: Part I of a report of the International Society for Bipolar Disorders Task Force on Suicide in Bipolar Disorder

PubMed Central

Schaffer, Ayal; Isometsä, Erkki T; Tondo, Leonardo; Moreno, Doris H; Sinyor, Mark; Kessing, Lars Vedel; Turecki, Gustavo; Weizman, Abraham; Azorin, Jean-Michel; Ha, Kyooseob; Reis, Catherine; Cassidy, Frederick; Goldstein, Tina; Rihmer, Zoltán; Beautrais, Annette; Chou, Yuan-Hwa; Diazgranados, Nancy; Levitt, Anthony J; Zarate, Carlos A; Yatham, Lakshmi

2016-01-01

Objectives Bipolar disorder is associated with elevated risk of suicide attempts and deaths. Key aims of the International Society for Bipolar Disorders Task Force on Suicide included examining the extant literature on epidemiology, neurobiology and pharmacotherapy related to suicide attempts and deaths in bipolar disorder. Methods Systematic review of studies from 1 January 1980 to 30 May 2014 examining suicide attempts or deaths in bipolar disorder, with a specific focus on the incidence and characterization of suicide attempts and deaths, genetic and non-genetic biological studies and pharmacotherapy studies specific to bipolar disorder. We conducted pooled, weighted analyses of suicide rates. Results The pooled suicide rate in bipolar disorder is 164 per 100,000 person-years (95% confidence interval = [5, 324]). Sex-specific data on suicide rates identified a 1.7:1 ratio in men compared to women. People with bipolar disorder account for 3.4–14% of all suicide deaths, with self-poisoning and hanging being the most common methods. Epidemiological studies report that 23–26% of people with bipolar disorder attempt suicide, with higher rates in clinical samples. There are numerous genetic associations with suicide attempts and deaths in bipolar disorder, but few replication studies. Data on treatment with lithium or anticonvulsants are strongly suggestive for prevention of suicide attempts and deaths, but additional data are required before relative anti-suicide effects can be confirmed. There were limited data on potential anti-suicide effects of treatment with antipsychotics or antidepressants. Conclusion This analysis identified a lower estimated suicide rate in bipolar disorder than what was previously published. Understanding the overall risk of suicide deaths and attempts, and the most common methods, are important building blocks to greater awareness and improved interventions for suicide prevention in bipolar disorder. Replication of genetic findings and

Bipolar disorder diagnosis: challenges and future directions

PubMed Central

Phillips, Mary L; Kupfer, David J

2018-01-01

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

Psychopharmacological treatment of psychotic mania and psychotic bipolar depression compared to non-psychotic mania and non-psychotic bipolar depression.

PubMed

Bjørklund, Louise B; Horsdal, Henriette T; Mors, Ole; Gasse, Christiane; Østergaard, Søren D

2017-09-01

An evidence base for the treatment of mania and bipolar depression with psychotic symptoms is lacking. Nevertheless, clinicians may have a preference for treating episodes of bipolar disorder with or without psychotic symptoms in different ways, which is likely to reflect notions of differential efficacy of treatments between these subtypes. This study aimed to investigate whether the psychopharmacological treatment of psychotic and non-psychotic episodes of mania and bipolar depression, respectively, differs in clinical practice. We conducted a register-based study assessing the psychopharmacological treatment of all individuals receiving their first diagnosis of mania or bipolar depression between 2010 and 2012. The psychopharmacological treatment within 3 months following the time of diagnosis was considered. Potential differences in psychopharmacological treatment between the psychotic and non-psychotic subtypes of mania and bipolar depression, respectively, were investigated by means of Pearson's χ 2 test and logistic regression adjusted for sex and age at diagnosis of bipolar disorder. A total of 827 patients were included in the analyses. The adjusted odds ratio (aOR) for treatment with an antipsychotic was 1.71 (95% confidence interval [CI]: 1.18-2.48, P<.01) for psychotic mania and 3.89 (95% CI: 1.95-7.76, P<.001) for psychotic bipolar depression. The aOR for treatment with the combination of an antipsychotic and an anticonvulsant was 1.60 (95% CI: 1.06-2.43, P<.05) for psychotic mania. The aOR for treatment with the combination of an antipsychotic and an antidepressant was 2.50 (95% CI: 1.43-4.37, P<.01) for bipolar psychotic depression. It would be of interest to conduct studies evaluating whether antipsychotics represent the superior pharmacological treatment for psychotic mania and psychotic bipolar depression. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Family environment patterns in families with bipolar children.

PubMed

Belardinelli, Cecilia; Hatch, John P; Olvera, Rene L; Fonseca, Manoela; Caetano, Sheila C; Nicoletti, Mark; Pliszka, Steven; Soares, Jair C

2008-04-01

We studied the characteristics of family functioning in bipolar children and healthy comparison children. We hypothesized that the family environment of bipolar children would show greater levels of dysfunction as measured by the Family Environment Scale (FES). We compared the family functioning of 36 families that included a child with DSM-IV bipolar disorder versus 29 comparison families that included only healthy children. All subjects and their parents were assessed with the K-SADS-PL interview. The parents completed the FES to assess their current family functioning. Multivariate analysis of variance was used to compare the family environment of families with and without offspring with bipolar disorder. Parents of bipolar children reported lower levels of family cohesion (p<0.001), expressiveness (p=0.005), active-recreational orientation (p<0.001), intellectual-cultural orientation (p=0.04) and higher levels of conflict (p<0.001) compared to parents with no bipolar children. Secondary analyses within the bipolar group revealed lower levels of organization (p=0.031) and cohesion (p=0.014) in families where a parent had a history of mood disorders compared to families where parents had no history of mood disorders. Length of illness in the affected child was inversely associated with family cohesion (r=-0.47, p=0.004). Due to the case-control design of the study, we cannot comment on the development of these family problems or attribute their cause specifically to child bipolar disorder. Families with bipolar children show dysfunctional patterns related to interpersonal interactions and personal growth. A distressed family environment should be addressed when treating children with bipolar disorder.

Differential diagnosis of bipolar disorder and major depressive disorder.

PubMed

Hirschfeld, R M

2014-12-01

Patients with bipolar disorder spend approximately half of their lives symptomatic and the majority of that time suffering from symptoms of depression, which complicates the accurate diagnosis of bipolar disorder. Challenges in the differential diagnosis of bipolar disorder and major depressive disorder are reviewed, and the clinical utility of several screening instruments is evaluated. The estimated lifetime prevalence of major depressive disorder (i.e., unipolar depression) is over 3 and one-half times that of bipolar spectrum disorders. The clinical presentation of a major depressive episode in a bipolar disorder patient does not differ substantially from that of a patient with major depressive disorder (unipolar depression). Therefore, it is not surprising that without proper screening and comprehensive evaluation many patients with bipolar disorder may be misdiagnosed with major depressive disorder (unipolar depression). In general, antidepressants have demonstrated little or no efficacy for depressive episodes associated with bipolar disorder, and treatment guidelines recommend using antidepressants only as an adjunct to mood stabilizers for patients with bipolar disorder. Thus, correct identification of bipolar disorder among patients who present with depression is critical for providing appropriate treatment and improving patient outcomes. Clinical characteristics indicative of bipolar disorder versus major depressive disorder identified in this review are based on group differences and may not apply to each individual patient. The overview of demographic and clinical characteristics provided by this review may help medical professionals distinguish between major depressive disorder and bipolar disorder. Several validated, easily administered screening instruments are available and can greatly improve the recognition of bipolar disorder in patients with depression. Copyright © 2014 Elsevier B.V. All rights reserved.

The bipolar II disorder personality traits, a true syndrome?

PubMed

Gudmundsson, Einar

2015-06-01

The author was struck by the similarities and commonality of complaints, aside from mood swings, made by Bipolar II patients and started registrating these complaints. This registrational work eventually led to the development of The Bipolar II Syndome Checklist. The aim of this work was to understand how widely the Bipolar II disorder affects the personality, and what disturbing personality traits are the most common? Deliberately, no attempt was made to diagnose psychiatric comorbidities, in the hope that one would get a clearer view of what symptoms, if any, could be considered a natural part of the Bipolar II Disorder. As far as the author knows this is a novel approach. 105 Bipolar II patients completed the Bipolar II Syndrome Checklist. The answers to the 44 questions on the list are presented in tables. Symptoms like anxiety, low self esteem, paranoia, extreme hurtfulness, migraine, Post Partum Depression, obsessive traits, alcoholism in the family are amongst the findings which will be presented in greater detail. No control group. Bipolar I patients excluded. The Bipolar II Syndrome Checklist has not been systematically validated. The results show that Bipolar II Disorder causes multiple symptoms so commonly that it may be justified to describe it as a syndrome, The Bipolar II Syndrome. Also these disturbances commonly lie in families of Bipolar II patients and are in all likelihood, greatly underdiagnosed. The clinical relevance of this study lies in increasing our knowledge and understanding of the nature of the Bipolar II Disorder, which in all probability will increase the diagnostic and treatment accuracy, since clinicians are more likely to scan for other symptoms needing treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

Multiple-channel detection of cellular activities by ion-sensitive transistors

NASA Astrophysics Data System (ADS)

Machida, Satoru; Shimada, Hideto; Motoyama, Yumi

2018-04-01

An ion-sensitive field-effect transistor to record cellular activities was demonstrated. This field-effect transistor (bio transistor) includes cultured cells on the gate insulator instead of gate electrode. The bio transistor converts a change in potential underneath the cells into variation of the drain current when ion channels open. The bio transistor has high detection sensitivity to even minute variations in potential utilizing a subthreshold swing region. To open ion channels, a reagent solution (acetylcholine) was added to a human-originating cell cultured on the bio transistor. The drain current was successfully decreased with the addition of acetylcholine. Moreover, we attempted to detect the opening of ion channels using a multiple-channel measurement circuit containing several bio transistors. As a consequence, the drain current distinctly decreased only after the addition of acetylcholine. We confirmed that this measurement system including bio transistors enables to observation of cellular activities sensitively and simultaneously.

Multimode Silicon Nanowire Transistors

PubMed Central

2014-01-01

The combined capabilities of both a nonplanar design and nonconventional carrier injection mechanisms are subject to recent scientific investigations to overcome the limitations of silicon metal oxide semiconductor field effect transistors. In this Letter, we present a multimode field effect transistors device using silicon nanowires that feature an axial n-type/intrinsic doping junction. A heterostructural device design is achieved by employing a self-aligned nickel-silicide source contact. The polymorph operation of the dual-gate device enabling the configuration of one p- and two n-type transistor modes is demonstrated. Not only the type but also the carrier injection mode can be altered by appropriate biasing of the two gate terminals or by inverting the drain bias. With a combined band-to-band and Schottky tunneling mechanism, in p-type mode a subthreshold swing as low as 143 mV/dec and an ON/OFF ratio of up to 104 is found. As the device operates in forward bias, a nonconventional tunneling transistor is realized, enabling an effective suppression of ambipolarity. Depending on the drain bias, two different n-type modes are distinguishable. The carrier injection is dominated by thermionic emission in forward bias with a maximum ON/OFF ratio of up to 107 whereas in reverse bias a Schottky tunneling mechanism dominates the carrier transport. PMID:25303290

Self-protecting transistor oscillator for treating animal tissues

DOEpatents

Doss, James D.

1980-01-01

A transistor oscillator circuit wherein the load current applied to animal tissue treatment electrodes is fed back to the transistor. Removal of load is sensed to automatically remove feedback and stop oscillations. A thermistor on one treatment electrode senses temperature, and by means of a control circuit controls oscillator transistor current.

[Recurrences of bipolar disorders - comparative study of bipolar disorders, recurring depressions and single depressions in a cohort of patients aged over 65 years].

PubMed

Galland, F; Vaille-Perret, E; Gerbaud, L; Jalenques, I

2007-09-01

Bipolar mood disorders, after starting at adulthood, may remain active throughout life, but bipolar disorders may only be revealed in later life. Indeed, Yet few data on bipolar disorders in the elderly have been reported in the litterature. The influence of normal aging on the outcome of the disease as well as the specific prognosis of bipolar disorders in the elderly has occasionally been studied. Eventually Finally, and contrasting with adults, few studies comparing the various subtypes of mood disorders were have been performed in the elderly. We therefore developed a study in patients aged 65 or above, in order to evaluate the course (recurrences) of bipolar disorders, compared to recurring depressions and single depressions, and to determine the influence of recurrences on the outcome of bipolar disorders. Patients aged over 65 years were inpatients admitted to the department of psychiatry in 2000 for one of the three previously mentioned diagnoses according to DSM IV. Retrospective data were collected from medical reports. Prospectively, data were collected from the general practitioner of each patient (relying on telephone calls), before statistical analysis was performed. Our study demonstrates a more severe outcome for bipolar disorders compared to recurring depressions and single depressions. Patients with bipolar disorders have a higher prevalence of psychiatric recurrences. Furthermore, the greater the number of previous relapses (or the longer the duration and intensity of the disease), the higher the risk of future new future recurrences both in bipolar disorders and recurring depressions. An age of onset of bipolar disorders before 60 years and more than 5 in-hospital admissions increase the risk of recurrences. We originally compare the outcome of bipolar disorders in the elderly, to recurring depressions and single depressions. We confirm the fatal outcome of recurrences in bipolar disorders in old age. Bipolar disorders in the elderly should be

Bipolar diagnosis in China: Evaluating diagnostic confidence using the Bipolarity Index.

PubMed

Ma, Yantao; Gao, Huimin; Yu, Xin; Si, Tianmei; Wang, Gang; Fang, Yiru; Liu, Zhening; Sun, Jing; Yang, Haichen; Wang, Xueyi; Li, Jing; Zhang, Yonghua; Sachs, Gary

2016-09-15

Diagnosis of bipolar disorder is inherently difficult. The goal of this study was to examine the utility and psychometric properties of the Bipolarity Index (BPx) in a population of patients treated in China. At nine Chinese health facilities participating in CAFÉ-BD, clinicians completed a standardized affective disorder evaluation for consecutive patients (N=615) with a clinical diagnosis of MDD and BPD and scored the Bipolarity Index. The investigators constructed ROC curves to determine the optimal cut off points to discriminate subjects in three clinical diagnostic groups: bipolar disorder (BPD), major depressive disorder (MDD) and healthy (no psychiatric diagnosis) controls (HC). This study is registered with ClinicalTrials.gov, number NCT02015143. 1) The cut-off score between the MDD and BPD groups was 42.0, with a sensitivity of 0.957 and specificity of 0.881 (Z=63.064, P<0.001); the cut-off score between the MDD and BPD II groups was 34.0, with a sensitivity of 0.810 and specificity of 0.855 (Z=20.174, P<0.001); and the cut-off score between the BPD II and BPD I groups was 57.0, with a sensitivity of 0.680 and specificity of 0.772 (Z=9.636, P<0.001). 2) Five domains contributed to the discrimination results. State-related domains (episode characteristics and course of illness) made greater contributions than trait-related domains (age of onset, family history, and treatment response). The data are purely descriptive. The BPD II sample and the family history dataset were small. Our finding indicates good reliability and validity for the Chinese version of the BPx, which encourages its use as a measure of diagnostic confidence for bipolar spectrum disorders. Further prospective study is necessary to determine if the BPx is useful in identifying subgroups among MDD subjects at high risk for conversion to BPD. Copyright © 2016 Elsevier B.V. All rights reserved.

Exercising control over bipolar disorder.

PubMed

Malhi, Gin S; Byrow, Yulisha

2016-11-01

Following extensive research exercise has emerged as an effective treatment for major depressive disorder, and it is now a recognised therapy alongside other interventions. In contrast, there is a paucity of research examining the therapeutic effects of exercise for those with bipolar disorder. Given that dysfunctional reward processing is central to bipolar disorder, research suggests that exercise can perhaps be framed as a reward-related event that may have the potential to precipitate a manic episode. The behavioural activation system (BAS) is a neurobehavioural system that is associated with responding to reward and provides an appropriate framework to theoretically examine and better understand the effects of exercise treatment on bipolar disorder. This article discusses recent research findings and provides an overview of the extant literature related to the neurobiological underpinnings of BAS and exercise as they relate to bipolar disorder. This is important clinically because depending on mood state in bipolar disorder, we postulate that exercise could be either beneficial or deleterious with positive or negative effects on the illness. Clearly, this complicates the evaluation of exercise as a potential treatment in terms of identifying its optimal characteristics in this population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Doped organic transistors operating in the inversion and depletion regime

PubMed Central

Lüssem, Björn; Tietze, Max L.; Kleemann, Hans; Hoßbach, Christoph; Bartha, Johann W.; Zakhidov, Alexander; Leo, Karl

2013-01-01

The inversion field-effect transistor is the basic device of modern microelectronics and is nowadays used more than a billion times on every state-of-the-art computer chip. In the future, this rigid technology will be complemented by flexible electronics produced at extremely low cost. Organic field-effect transistors have the potential to be the basic device for flexible electronics, but still need much improvement. In particular, despite more than 20 years of research, organic inversion mode transistors have not been reported so far. Here we discuss the first realization of organic inversion transistors and the optimization of organic depletion transistors by our organic doping technology. We show that the transistor parameters—in particular, the threshold voltage and the ON/OFF ratio—can be controlled by the doping concentration and the thickness of the transistor channel. Injection of minority carriers into the doped transistor channel is achieved by doped contacts, which allows forming an inversion layer. PMID:24225722

Kilovolt dc solid state remote power controller development

NASA Technical Reports Server (NTRS)

Mitchell, J. T.

1982-01-01

The experience gained in developing and applying solid state power controller (SSPC) technology at high voltage dc (HVDC) potentials and power levels of up to 25 kilowatts is summarized. The HVDC switching devices, power switching concepts, drive circuits, and very fast acting overcurrent protection circuits were analyzed. A 25A bipolar breadboard with Darlington connected switching transistor was built. Fault testing at 900 volts was included. A bipolar transistor packaged breadboard design was developed. Power MOSFET remote power controller (RPC) was designed.

[Bipolar disorders and anorexia nervosa: A clinical study].

PubMed

Valentin, M; Radon, L; Duclos, J; Curt, F; Godart, N

2018-06-20

Anorexia nervosa is often accompanied by comorbid mood disorders, in particular depression, but individual or family history of bipolar disorders has not frequently been explored in anorexia nervosa. The objectives of the present study were: (1) to assess the frequency of bipolar disorders in patients with anorexia nervosa hospitalized in adolescence and in their parents, (2) to determine whether the patients with a personal or family history of bipolar disorders present particular characteristics in the way in which anorexia nervosa manifests itself, in their medical history, in the secondary diagnoses established, and in the treatments prescribed. Overall, 97 female patients aged 13 to 20 hospitalized for anorexia nervosa and their parents were assessed. The diagnoses of anorexia nervosa and bipolar disorders were established on the basis of DSM-IV-TR criteria. A high frequency of type II and type V bipolar disorders was observed. The patients with anorexia nervosa and presenting personal or family histories of bipolar disorder had an earlier onset of anorexia nervosa, more numerous hospitalizations, a longer time-lapse between anorexia nervosa onset and hospitalization, more suicide attempts and more psychiatric comorbidities. The occurrence of anorexia nervosa-bipolar disorders comorbidity appears to be considerable and linked to the severity of anorexia nervosa, raising the issue of the relationship between anorexia nervosa and bipolar disorders. Copyright © 2017. Published by Elsevier Masson SAS.

CMOS-based carbon nanotube pass-transistor logic integrated circuits

PubMed Central

Ding, Li; Zhang, Zhiyong; Liang, Shibo; Pei, Tian; Wang, Sheng; Li, Yan; Zhou, Weiwei; Liu, Jie; Peng, Lian-Mao

2012-01-01

Field-effect transistors based on carbon nanotubes have been shown to be faster and less energy consuming than their silicon counterparts. However, ensuring these advantages are maintained for integrated circuits is a challenge. Here we demonstrate that a significant reduction in the use of field-effect transistors can be achieved by constructing carbon nanotube-based integrated circuits based on a pass-transistor logic configuration, rather than a complementary metal-oxide semiconductor configuration. Logic gates are constructed on individual carbon nanotubes via a doping-free approach and with a single power supply at voltages as low as 0.4 V. The pass-transistor logic configurarion provides a significant simplification of the carbon nanotube-based circuit design, a higher potential circuit speed and a significant reduction in power consumption. In particular, a full adder, which requires a total of 28 field-effect transistors to construct in the usual complementary metal-oxide semiconductor circuit, uses only three pairs of n- and p-field-effect transistors in the pass-transistor logic configuration. PMID:22334080

Triple-mode single-transistor graphene amplifier and its applications.

PubMed

Yang, Xuebei; Liu, Guanxiong; Balandin, Alexander A; Mohanram, Kartik

2010-10-26

We propose and experimentally demonstrate a triple-mode single-transistor graphene amplifier utilizing a three-terminal back-gated single-layer graphene transistor. The ambipolar nature of electronic transport in graphene transistors leads to increased amplifier functionality as compared to amplifiers built with unipolar semiconductor devices. The ambipolar graphene transistors can be configured as n-type, p-type, or hybrid-type by changing the gate bias. As a result, the single-transistor graphene amplifier can operate in the common-source, common-drain, or frequency multiplication mode, respectively. This in-field controllability of the single-transistor graphene amplifier can be used to realize the modulation necessary for phase shift keying and frequency shift keying, which are widely used in wireless applications. It also offers new opportunities for designing analog circuits with simpler structure and higher integration densities for communications applications.

Modeling bipolar stimulation of cardiac tissue

NASA Astrophysics Data System (ADS)

Galappaththige, Suran K.; Gray, Richard A.; Roth, Bradley J.

2017-09-01

Unipolar stimulation of cardiac tissue is often used in the design of cardiac pacemakers because of the low current required to depolarize the surrounding tissue at rest. However, the advantages of unipolar over bipolar stimulation are not obvious at shorter coupling intervals when the tissue near the pacing electrode is relatively refractory. Therefore, this paper analyzes bipolar stimulation of cardiac tissue. The strength-interval relationship for bipolar stimulation is calculated using the bidomain model and a recently developed parsimonious ionic current model. The strength-interval curves obtained using different electrode separations and arrangements (electrodes placed parallel to the fibers versus perpendicular to the fibers) indicate that bipolar stimulation results in more complex activation patterns compared to unipolar stimulation. An unusually low threshold stimulus current is observed when the electrodes are close to each other (a separation of 1 mm) because of break excitation. Unlike for unipolar stimulation, anode make excitation is not present during bipolar stimulation, and an abrupt switch from anode break to cathode make excitation can cause dramatic changes in threshold with very small changes in the interval. These results could impact the design of implantable pacemakers and defibrillators.

Thermal transistor utilizing gas-liquid transition.

PubMed

Komatsu, Teruhisa S; Ito, Nobuyasu

2011-01-01

We propose a simple thermal transistor, a device to control heat current. In order to effectively change the current, we utilize the gas-liquid transition of the heat-conducting medium (fluid) because the gas region can act as a good thermal insulator. The three terminals of the transistor are located at both ends and the center of the system, and are put into contact with distinct heat baths. The key idea is a special arrangement of the three terminals. The temperature at one end (the gate temperature) is used as an input signal to control the heat current between the center (source, hot) and another end (drain, cold). Simulating the nanoscale systems of this transistor, control of heat current is demonstrated. The heat current is effectively cut off when the gate temperature is cold and it flows normally when it is hot. By using an extended version of this transistor, we also simulate a primitive application for an inverter.

Water-gel for gating graphene transistors.

PubMed

Kim, Beom Joon; Um, Soong Ho; Song, Woo Chul; Kim, Yong Ho; Kang, Moon Sung; Cho, Jeong Ho

2014-05-14

Water, the primary electrolyte in biology, attracts significant interest as an electrolyte-type dielectric material for transistors compatible with biological systems. Unfortunately, the fluidic nature and low ionic conductivity of water prevents its practical usage in such applications. Here, we describe the development of a solid state, megahertz-operating, water-based gate dielectric system for operating graphene transistors. The new electrolyte systems were prepared by dissolving metal-substituted DNA polyelectrolytes into water. The addition of these biocompatible polyelectrolytes induced hydrogelation to provide solid-state integrity to the system. They also enhanced the ionic conductivities of the electrolytes, which in turn led to the quick formation of an electric double layer at the graphene/electrolyte interface that is beneficial for modulating currents in graphene transistors at high frequencies. At the optimized conditions, the Na-DNA water-gel-gated flexible transistors and inverters were operated at frequencies above 1 MHz and 100 kHz, respectively.

Olfactocentric paralimbic cortex morphology in adolescents with bipolar disorder

PubMed Central

Wang, Fei; Kalmar, Jessica H.; Womer, Fay Y.; Edmiston, Erin E.; Chepenik, Lara G.; Chen, Rachel; Spencer, Linda

2011-01-01

The olfactocentric paralimbic cortex plays a critical role in the regulation of emotional and neurovegetative functions that are disrupted in core features of bipolar disorder. Adolescence is thought to be a critical period in both the maturation of the olfactocentric paralimbic cortex and in the emergence of bipolar disorder pathology. Together, these factors implicate a central role for the olfactocentric paralimbic cortex in the development of bipolar disorder and suggest that abnormalities in this cortex may be expressed by adolescence in the disorder. We tested the hypothesis that differences in olfactocentric paralimbic cortex structure are a morphological feature in adolescents with bipolar disorder. Subjects included 118 adolescents (41 with bipolar disorder and 77 healthy controls). Cortical grey matter volume differences between adolescents with and without bipolar disorder were assessed with voxel-based morphometry analyses of high-resolution structural magnetic resonance imaging scans. Compared with healthy comparison adolescents, adolescents with bipolar disorder demonstrated significant volume decreases in olfactocentric paralimbic regions, including orbitofrontal, insular and temporopolar cortices. Findings in these regions survived small volume correction (P < 0.05, corrected). Volume decreases in adolescents with bipolar disorder were also noted in inferior prefrontal and superior temporal gyri and cerebellum. The findings suggest that abnormalities in the morphology of the olfactocentric paralimbic cortex may contribute to the bipolar disorder phenotype that emerges in adolescence. The morphological development of the olfactocentric paralimbic cortex has received little study. The importance of these cortices in emotional and social development, and support for a central role for these cortices in the development of bipolar disorder, suggest that study of the development of these cortices in health and in bipolar disorder is critically needed

Olfactocentric paralimbic cortex morphology in adolescents with bipolar disorder.

PubMed

Wang, Fei; Kalmar, Jessica H; Womer, Fay Y; Edmiston, Erin E; Chepenik, Lara G; Chen, Rachel; Spencer, Linda; Blumberg, Hilary P

2011-07-01

The olfactocentric paralimbic cortex plays a critical role in the regulation of emotional and neurovegetative functions that are disrupted in core features of bipolar disorder. Adolescence is thought to be a critical period in both the maturation of the olfactocentric paralimbic cortex and in the emergence of bipolar disorder pathology. Together, these factors implicate a central role for the olfactocentric paralimbic cortex in the development of bipolar disorder and suggest that abnormalities in this cortex may be expressed by adolescence in the disorder. We tested the hypothesis that differences in olfactocentric paralimbic cortex structure are a morphological feature in adolescents with bipolar disorder. Subjects included 118 adolescents (41 with bipolar disorder and 77 healthy controls). Cortical grey matter volume differences between adolescents with and without bipolar disorder were assessed with voxel-based morphometry analyses of high-resolution structural magnetic resonance imaging scans. Compared with healthy comparison adolescents, adolescents with bipolar disorder demonstrated significant volume decreases in olfactocentric paralimbic regions, including orbitofrontal, insular and temporopolar cortices. Findings in these regions survived small volume correction (P < 0.05, corrected). Volume decreases in adolescents with bipolar disorder were also noted in inferior prefrontal and superior temporal gyri and cerebellum. The findings suggest that abnormalities in the morphology of the olfactocentric paralimbic cortex may contribute to the bipolar disorder phenotype that emerges in adolescence. The morphological development of the olfactocentric paralimbic cortex has received little study. The importance of these cortices in emotional and social development, and support for a central role for these cortices in the development of bipolar disorder, suggest that study of the development of these cortices in health and in bipolar disorder is critically needed.

Toward a complex system understanding of bipolar disorder: A chaotic model of abnormal circadian activity rhythms in euthymic bipolar disorder.

PubMed

Hadaeghi, Fatemeh; Hashemi Golpayegani, Mohammad Reza; Jafari, Sajad; Murray, Greg

2016-08-01

In the absence of a comprehensive neural model to explain the underlying mechanisms of disturbed circadian function in bipolar disorder, mathematical modeling is a helpful tool. Here, circadian activity as a response to exogenous daily cycles is proposed to be the product of interactions between neuronal networks in cortical (cognitive processing) and subcortical (pacemaker) areas of the brain. To investigate the dynamical aspects of the link between disturbed circadian activity rhythms and abnormalities of neurotransmitter functioning in frontal areas of the brain, we developed a novel mathematical model of a chaotic system which represents fluctuations in circadian activity in bipolar disorder as changes in the model's parameters. A novel map-based chaotic system was developed to capture disturbances in circadian activity across the two extreme mood states of bipolar disorder. The model uses chaos theory to characterize interplay between neurotransmitter functions and rhythm generation; it aims to illuminate key activity phenomenology in bipolar disorder, including prolonged sleep intervals, decreased total activity and attenuated amplitude of the diurnal activity rhythm. To test our new cortical-circadian mathematical model of bipolar disorder, we utilized previously collected locomotor activity data recorded from normal subjects and bipolar patients by wrist-worn actigraphs. All control parameters in the proposed model have an important role in replicating the different aspects of circadian activity rhythm generation in the brain. The model can successfully replicate deviations in sleep/wake time intervals corresponding to manic and depressive episodes of bipolar disorder, in which one of the excitatory or inhibitory pathways is abnormally dominant. Although neuroimaging research has strongly implicated a reciprocal interaction between cortical and subcortical regions as pathogenic in bipolar disorder, this is the first model to mathematically represent this

Bipolar electrochemistry.

PubMed

Fosdick, Stephen E; Knust, Kyle N; Scida, Karen; Crooks, Richard M

2013-09-27

A bipolar electrode (BPE) is an electrically conductive material that promotes electrochemical reactions at its extremities (poles) even in the absence of a direct ohmic contact. More specifically, when sufficient voltage is applied to an electrolyte solution in which a BPE is immersed, the potential difference between the BPE and the solution drives oxidation and reduction reactions. Because no direct electrical connection is required to activate redox reactions, large arrays of electrodes can be controlled with just a single DC power supply or even a battery. The wireless aspect of BPEs also makes it possible to electrosynthesize and screen novel materials for a wide variety of applications. Finally, bipolar electrochemistry enables mobile electrodes, dubbed microswimmers, that are able to move freely in solution. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CMOS-compatible InP/InGaAs digital photoreceiver

DOEpatents

Lovejoy, Michael L.; Rose, Benny H.; Craft, David C.; Enquist, Paul M.; Slater, Jr., David B.

1997-01-01

A digital photoreceiver is formed monolithically on an InP semiconductor substrate and comprises a p-i-n photodetector formed from a plurality of InP/InGaAs layers deposited by an epitaxial growth process and an adjacent heterojunction bipolar transistor (HBT) amplifier formed from the same InP/InGaAs layers. The photoreceiver amplifier operates in a large-signal mode to convert a detected photocurrent signal into an amplified output capable of directly driving integrated circuits such as CMOS. In combination with an optical transmitter, the photoreceiver may be used to establish a short-range channel of digital optical communications between integrated circuits with applications to multi-chip modules (MCMs). The photoreceiver may also be used with fiber optic coupling for establishing longer-range digital communications (i.e. optical interconnects) between distributed computers or the like. Arrays of digital photoreceivers may be formed on a common substrate for establishing a plurality of channels of digital optical communication, with each photoreceiver being spaced by less than about 1 mm and consuming less than about 20 mW of power, and preferably less than about 10 mW. Such photoreceiver arrays are useful for transferring huge amounts of digital data between integrated circuits at bit rates of up to about 1000 Mb/s or more.

Multi-mode multi-band power amplifier module with high low-power efficiency

NASA Astrophysics Data System (ADS)

Xuguang, Zhang; Jie, Jin

2015-10-01

Increasingly, mobile communications standards require high power efficiency and low currents in the low power mode. This paper proposes a fully-integrated multi-mode and multi-band power amplifier module (PAM) to meet these requirements. A dual-path PAM is designed for high-power mode (HPM), medium-power mode (MPM), and low-power mode (LPM) operations without any series switches for different mode selection. Good performance and significant current saving can be achieved by using an optimized load impedance design for each power mode. The PAM is tapeout with the InGaP/GaAs heterojunction bipolar transistor (HBT) process and the 0.18-μm complementary metal-oxide semiconductor (CMOS) process. The test results show that the PAM achieves a very low quiescent current of 3 mA in LPM. Meanwhile, across the 1.7-2.0 GHz frequency, the PAM performs well. In HPM, the output power is 28 dBm with at least 39.4% PAE and -40 dBc adjacent channel leakage ratio 1 (ACLR1). In MPM, the output power is 17 dBm, with at least 21.3% PAE and -43 dBc ACLR1. In LPM, the output power is 8 dBm, with at least 18.2% PAE and -40 dBc ACLR1. Project supported by the National Natural Science Foundation of China (No. 61201244).

CMOS-compatible InP/InGaAs digital photoreceiver

DOEpatents

Lovejoy, M.L.; Rose, B.H.; Craft, D.C.; Enquist, P.M.; Slater, D.B. Jr.

1997-11-04

A digital photoreceiver is formed monolithically on an InP semiconductor substrate and comprises a p-i-n photodetector formed from a plurality of InP/InGaAs layers deposited by an epitaxial growth process and an adjacent heterojunction bipolar transistor (HBT) amplifier formed from the same InP/InGaAs layers. The photoreceiver amplifier operates in a large-signal mode to convert a detected photocurrent signal into an amplified output capable of directly driving integrated circuits such as CMOS. In combination with an optical transmitter, the photoreceiver may be used to establish a short-range channel of digital optical communications between integrated circuits with applications to multi-chip modules (MCMs). The photoreceiver may also be used with fiber optic coupling for establishing longer-range digital communications (i.e. optical interconnects) between distributed computers or the like. Arrays of digital photoreceivers may be formed on a common substrate for establishing a plurality of channels of digital optical communication, with each photoreceiver being spaced by less than about 1 mm and consuming less than about 20 mW of power, and preferably less than about 10 mW. Such photoreceiver arrays are useful for transferring huge amounts of digital data between integrated circuits at bit rates of up to about 1,000 Mb/s or more. 4 figs.

Effects of carbon on phosphorus diffusion in SiGe:C and the implications on phosphorus diffusion mechanisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Yiheng; Xia, Guangrui; Yasuda, Hiroshi

2014-10-14

The use of carbon (C) in SiGe base layers is an important approach to control the base layer dopant phosphorus (P) diffusion and thus enhance PNP heterojunction bipolar transistor (HBT) performance. This work quantitatively investigated the carbon impacts on P diffusion in Si₀.₈₂Ge₀.₁₈:C and Si:C under rapid thermal anneal conditions. The carbon molar fraction is up to 0.32%. The results showed that the carbon retardation effect on P diffusion is less effective for Si₀.₈₂Ge₀.₁₈:C than for Si:C. In Si₀.₈₂Ge₀.₁₈:C, there is an optimum carbon content at around 0.05% to 0.1%, beyond which more carbon incorporation does not retard P diffusionmore » any more. This behavior is different from the P diffusion behavior in Si:C and the B in Si:C and low Ge SiGe:C, which can be explained by the decreased interstitial-mediated diffusion fraction f{sub I}{sup P,SiGe} to 95% as Ge content increases to 18%. Empirical models were established to calculate the time-averaged point defect concentrations and effective diffusivities as a function of carbon and was shown to agree with previous studies on boron, phosphorus, arsenic and antimony diffusion with carbon.« less

Mitochondrial Agents for Bipolar Disorder.

PubMed

Pereira, Círia; Chavarria, Victor; Vian, João; Ashton, Melanie Maree; Berk, Michael; Marx, Wolfgang; Dean, Olivia May

2018-03-27

Bipolar disorder is a chronic and often debilitating illness. Current treatment options (both pharmaco- and psychotherapy) have shown efficacy, but for many leave a shortfall in recovery. Advances in the understanding of the pathophysiology of bipolar disorder suggest that interventions that target mitochondrial dysfunction may provide a therapeutic benefit. This review explores the current and growing theoretical rationale as well as existing preclinical and clinical data for those therapies aiming to target the mitochondrion in bipolar disorder. A Clinicaltrials.gov and ANZCTR search was conducted for complete and ongoing trials on mitochondrial agents used in psychiatric disorders. A PubMed search was also conducted for literature published between January 1981 and July 2017. Systematic reviews, randomized controlled trials, observational studies, case series, and animal studies with an emphasis on agents affecting mitochondrial function and its role in bipolar disorder were included. The search was augmented by manually searching the references of key papers and related literature. The results were presented as a narrative review. Mitochondrial agents offer new horizons in mood disorder treatment. While some negative effects have been reported, most compounds are overall well tolerated and have generally benign side-effect profiles. The study of neuroinflammation, neurodegeneration, and mitochondrial function has contributed the understanding of bipolar disorder's pathophysiology. Agents targeting these pathways could be a potential therapeutic strategy. Future directions include identification of novel candidate mitochondrial modulators as well as rigorous and well-powered clinical trials.

Photon-triggered nanowire transistors

NASA Astrophysics Data System (ADS)

Kim, Jungkil; Lee, Hoo-Cheol; Kim, Kyoung-Ho; Hwang, Min-Soo; Park, Jin-Sung; Lee, Jung Min; So, Jae-Pil; Choi, Jae-Hyuck; Kwon, Soon-Hong; Barrelet, Carl J.; Park, Hong-Gyu

2017-10-01

Photon-triggered electronic circuits have been a long-standing goal of photonics. Recent demonstrations include either all-optical transistors in which photons control other photons or phototransistors with the gate response tuned or enhanced by photons. However, only a few studies report on devices in which electronic currents are optically switched and amplified without an electrical gate. Here we show photon-triggered nanowire (NW) transistors, photon-triggered NW logic gates and a single NW photodetection system. NWs are synthesized with long crystalline silicon (CSi) segments connected by short porous silicon (PSi) segments. In a fabricated device, the electrical contacts on both ends of the NW are connected to a single PSi segment in the middle. Exposing the PSi segment to light triggers a current in the NW with a high on/off ratio of >8 × 106. A device that contains two PSi segments along the NW can be triggered using two independent optical input signals. Using localized pump lasers, we demonstrate photon-triggered logic gates including AND, OR and NAND gates. A photon-triggered NW transistor of diameter 25 nm with a single 100 nm PSi segment requires less than 300 pW of power. Furthermore, we take advantage of the high photosensitivity and fabricate a submicrometre-resolution photodetection system. Photon-triggered transistors offer a new venue towards multifunctional device applications such as programmable logic elements and ultrasensitive photodetectors.

Photon-triggered nanowire transistors.

PubMed

Kim, Jungkil; Lee, Hoo-Cheol; Kim, Kyoung-Ho; Hwang, Min-Soo; Park, Jin-Sung; Lee, Jung Min; So, Jae-Pil; Choi, Jae-Hyuck; Kwon, Soon-Hong; Barrelet, Carl J; Park, Hong-Gyu

2017-10-01

Photon-triggered electronic circuits have been a long-standing goal of photonics. Recent demonstrations include either all-optical transistors in which photons control other photons or phototransistors with the gate response tuned or enhanced by photons. However, only a few studies report on devices in which electronic currents are optically switched and amplified without an electrical gate. Here we show photon-triggered nanowire (NW) transistors, photon-triggered NW logic gates and a single NW photodetection system. NWs are synthesized with long crystalline silicon (CSi) segments connected by short porous silicon (PSi) segments. In a fabricated device, the electrical contacts on both ends of the NW are connected to a single PSi segment in the middle. Exposing the PSi segment to light triggers a current in the NW with a high on/off ratio of >8 × 10 6 . A device that contains two PSi segments along the NW can be triggered using two independent optical input signals. Using localized pump lasers, we demonstrate photon-triggered logic gates including AND, OR and NAND gates. A photon-triggered NW transistor of diameter 25 nm with a single 100 nm PSi segment requires less than 300 pW of power. Furthermore, we take advantage of the high photosensitivity and fabricate a submicrometre-resolution photodetection system. Photon-triggered transistors offer a new venue towards multifunctional device applications such as programmable logic elements and ultrasensitive photodetectors.

Biological dysrhythm in remitted bipolar I disorder.

PubMed

Iyer, Aishwarya; Palaniappan, Pradeep

2017-12-01

Recent treatment guidelines support treatment of biological rhythm abnormalities as a part of treatment of bipolar disorder, but still, literature examining various domains (Sleep, Activity, Social, and Eating) of biological rhythm and its clinical predictors are less. The main aim of our study is to compare various domains of biological rhythm among remitted bipolar I subjects and healthy controls. We also explored for any association between clinical variables and biological rhythm among bipolar subjects. 40 subjects with Bipolar I disorder and 40 healthy controls who met inclusion and exclusion criteria were recruited for the study. Diagnoses were ascertained by a qualified psychiatrist using MINI 5.0. Sociodemographic details, biological rhythm (BRIAN-Biological Rhythm Interview of assessment in Neuropsychiatry) and Sleep functioning (PSQI- Pittsburgh Sleep Quality Index) were assessed in all subjects. Mean age of the Bipolar subjects and controls were 41.25±11.84years and 38.25±11.25 years respectively. Bipolar subjects experienced more biological rhythm disturbance when compared to healthy controls (total BRIAN score being 34.25±9.36 vs 28.2±6.53) (p=0.002). Subsyndromal depressive symptoms (HDRS) had significant positive correlation with BRIAN global scores(r=0.368, p=0.02). Linear regression analysis showed that number of episodes which required hospitalization (β=0.601, t=3.106, P=0.004), PSQI (β=0.394, t=2.609, p=0.014), HDRS (β=0.376, t=2.34, t=0.036) explained 31% of variance in BRIAN scores in remitted bipolar subjects. Biological rhythm disturbances seem to persist even after clinical remission of bipolar illness. More studies to look into the impact of subsyndromal depressive symptoms on biological rhythm are needed. Copyright © 2017 Elsevier B.V. All rights reserved.

Modeling of short channel MOS transistors

NASA Technical Reports Server (NTRS)

Lin, H. C.; Kokalis, D. P.; Bandy, W. R.

1976-01-01

Higher frequency response in MOS technology can be obtained by shortening the channel length. One approach for doing this involves an employment of higher resolution lithography technology. A second approach makes use of a double-diffused MOS transistor (DMOS). It is pointed out that the ordinary method of modeling the transistors used in both approaches is not accurate. An investigation is conducted of the questions which have to be considered for DMOS modeling. The modeling of a short channel MOS transistor is discussed, taking into account the derivation of the threshold voltage equation. Excellent agreement between theoretical and experimental data shows the accuracy of the described modeling approach.

Pass-transistor very large scale integration

NASA Technical Reports Server (NTRS)

Maki, Gary K. (Inventor); Bhatia, Prakash R. (Inventor)

2004-01-01

Logic elements are provided that permit reductions in layout size and avoidance of hazards. Such logic elements may be included in libraries of logic cells. A logical function to be implemented by the logic element is decomposed about logical variables to identify factors corresponding to combinations of the logical variables and their complements. A pass transistor network is provided for implementing the pass network function in accordance with this decomposition. The pass transistor network includes ordered arrangements of pass transistors that correspond to the combinations of variables and complements resulting from the logical decomposition. The logic elements may act as selection circuits and be integrated with memory and buffer elements.

Coping and personality in older patients with bipolar disorder.

PubMed

Schouws, Sigfried N T M; Paans, Nadine P G; Comijs, Hannie C; Dols, Annemiek; Stek, Max L

2015-09-15

Little is known about coping styles and personality traits in older bipolar patients. Adult bipolar patients show a passive coping style and higher neuroticism scores compared to the general population. Our aim is to investigate personality traits and coping in older bipolar patients and the relationship between coping and personality. 75 Older patients (age > 60) with bipolar I or II disorder in a euthymic mood completed the Utrecht Coping List and the NEO Personality Inventory FFI and were compared to normative data. Older bipolar patients show more passive coping styles compared to healthy elderly. Their personality traits are predominated by openness, in contrast conscientiousness and altruism are relatively sparse. Neuroticism was related to passive coping styles, whereas conscientiousness was related to an active coping style. Older bipolar patients have more passive coping styles. Their personality is characterized by openness and relatively low conscientiousness and altruism. Our sample represents a survival cohort; this may explain the differences in personality traits between older patients in this study and in adult bipolar patients in other studies. The association between coping styles and personality traits is comparable to reports of younger adult patients with bipolar disorder. Longitudinal studies are warranted to explore if coping and personality change with ageing in bipolar patients and to determine which coping style is most effective in preventing mood episodes. Copyright © 2015 Elsevier B.V. All rights reserved.

Bipolar Disorder

MedlinePlus

... periods of depressive symptoms (though less severe than major depression). Other types. These include, for example, bipolar and ... or making foolish investments Major depressive episode A major depressive episode ... insomnia or sleeping too much Either restlessness ...

Bipolar Disorder

MedlinePlus

... rule out other illnesses that might cause your mood changes. If not treated, bipolar disorder can lead to damaged relationships, poor job or school performance, and even suicide. However, there are effective treatments to control symptoms: ...

Genetic Risk Score Analysis in Early-Onset Bipolar Disorder

PubMed Central

Croarkin, Paul E.; Luby, Joan L.; Cercy, Kelly; Geske, Jennifer R.; Veldic, Marin; Simonson, Matthew; Joshi, Paramjit T.; Wagner, Karen Dineen; Walkup, John T.; Nassan, Malik M.; Cuellar-Barboza, Alfredo B.; Casuto, Leah; McElroy, Susan L.; Jensen, Peter S.; Frye, Mark A.; Biernacka, Joanna M.

2018-01-01

Objective In this study, we performed a candidate genetic risk score (GRS) analysis of early-onset bipolar disorder. Method Treatment of Early Age Mania (TEAM) study enrollment and sample collection took place from 2003–2008. Mayo Clinic Bipolar Biobank samples were collected from 2009–2013. Genotyping and analyses for the present study took place from 2013–2014. The diagnosis of bipolar disorder was based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria. Eight single-nucleotide polymorphisms (SNPs), previously reported in genome-wide association studies to be associated with bipolar disorder, were chosen for GRS analysis in early-onset bipolar disease. These SNPs map to 3 genes: CACNA1C (calcium channel, voltage-dependent, L type, alpha 1C subunit), ANK3 (ankyrin-3, node of Ranvier [ankyrin G]), and ODZ4 (teneurin transmembrane protein 4 [formerly “odz, odd Oz/ten-m homolog 4 {Drosophila}, ODZ4”]). The 8 candidate SNPs were genotyped in patients from the TEAM study (n=69), adult patients with bipolar disorder (n=732) including a subset with early-onset illness [n=192]), and healthy controls (n=776). GRS analyses were performed comparing early-onset cases with controls. In addition, associations of early-onset BD with individual SNPs and haplotypes were explored. Results GRS analysis revealed associations of the risk score with early-onset bipolar disorder (P=.01). Gene-level haplotype analysis comparing TEAM patients with controls suggested association of early-onset bipolar disorder with a CACNA1C haplotype (global test, P=.01). At the level of individual SNPs, comparison of TEAM cases with healthy controls provided nominally significant evidence for association of SNP rs10848632 in CACNA1C with early-onset bipolar disorder (P=.017), which did not remain significant after correction for multiple comparisons. Conclusion These preliminary analyses suggest that previously identified bipolar disorder risk loci

Ultrashort Channel Length Black Phosphorus Field-Effect Transistors.

PubMed

Miao, Jinshui; Zhang, Suoming; Cai, Le; Scherr, Martin; Wang, Chuan

2015-09-22

This paper reports high-performance top-gated black phosphorus (BP) field-effect transistors with channel lengths down to 20 nm fabricated using a facile angle evaporation process. By controlling the evaporation angle, the channel length of the transistors can be reproducibly controlled to be anywhere between 20 and 70 nm. The as-fabricated 20 nm top-gated BP transistors exhibit respectable on-state current (174 μA/μm) and transconductance (70 μS/μm) at a VDS of 0.1 V. Due to the use of two-dimensional BP as the channel material, the transistors exhibit relatively small short channel effects, preserving a decent on-off current ratio of 10(2) even at an extremely small channel length of 20 nm. Additionally, unlike the unencapsulated BP devices, which are known to be chemically unstable in ambient conditions, the top-gated BP transistors passivated by the Al2O3 gate dielectric layer remain stable without noticeable degradation in device performance after being stored in ambient conditions for more than 1 week. This work demonstrates the great promise of atomically thin BP for applications in ultimately scaled transistors.

Low electron mobility of field-effect transistor determined by modulated magnetoresistance

NASA Astrophysics Data System (ADS)

Tauk, R.; Łusakowski, J.; Knap, W.; Tiberj, A.; Bougrioua, Z.; Azize, M.; Lorenzini, P.; Sakowicz, M.; Karpierz, K.; Fenouillet-Beranger, C.; Cassé, M.; Gallon, C.; Boeuf, F.; Skotnicki, T.

2007-11-01

Room temperature magnetotransport experiments were carried out on field-effect transistors in magnetic fields up to 10 T. It is shown that measurements of the transistor magnetoresistance and its first derivative with respect to the gate voltage allow the derivation of the electron mobility in the gated part of the transistor channel, while the access/contact resistances and the transistor gate length need not be known. We demonstrate the potential of this method using GaN and Si field-effect transistors and discuss its importance for mobility measurements in transistors with nanometer gate length.

Carbon Doping of Compound Semiconductor Epitaxial Layers Grown by Metalorganic Chemical Vapor Deposition Using Carbon Tetrachloride.

NASA Astrophysics Data System (ADS)

Cunningham, Brian Thomas

1990-01-01

A dilute mixture of CCl_4 in high purity H_2 has been used as a carbon dopant source for rm Al_ {x}Ga_{1-x}As grown by low pressure metalorganic chemical vapor deposition (MOCVD). To understand the mechanism for carbon incorporation from CCl_4 doping and to provide experimental parameters for the growth of carbon doped device structures, the effects of various crystal growth parameters on CCl _4 doping have been studied, including growth temperature, growth rate, V/III ratio, Al composition, and CCl_4 flow rate. Although CCl _4 is an effective p-type dopant for MOCVD rm Al_{x}Ga_ {1-x}As, injection of CCl_4 into the reactor during growth of InP resulted in no change in the carrier concentration or carbon concentration. Abrupt, heavy carbon doping spikes in GaAs have been obtained using CCl_4 without a dopant memory effect. By annealing samples with carbon doping spikes grown within undoped, n-type, and p-type GaAs, the carbon diffusion coefficient in GaAs at 825 ^circC has been estimated and has been found to depend strongly on the GaAs background doping. Heavily carbon doped rm Al_{x}Ga _{1-x}As/GaAs superlattices have been found to be more stable against impurity induced layer disordering (IILD) than Mg or Zn doped superlattices, indicating that the low carbon diffusion coefficient limits the IILD process. Carbon doping has been used in the base region on an Npn AlGaAs/GaAs heterojunction bipolar transistor (HBT). Transistors with 3 x 10 μm self-aligned emitter fingers have been fabricated which exhibit a current gain cutoff frequency of f_ {rm t} = 26 GHz.

Suicide attempts and clinical features of bipolar patients.

PubMed

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

2016-06-01

To identify clinical predictors of suicide attempts in patients with bipolar disorder. This study included bipolar patients who were treated in the Psychiatry Department, Haseki Training and Research Hospital, Istanbul, Turkey, between 2013 and 2014; an informed consent was obtained from the participants. Two  hundred and eighteen bipolar patients were assessed by using the structured clinical interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) Axis-I (SCID-I) in order to detect all possible psychiatric comorbid diagnoses. Clinical predictors of suicide attempts were examined in attempters and non-attempters. The study design was retrospective. The lifetime suicide attempt rate for the entire sample was 19.2%. Suicide attempters with bipolar disorder had more lifetime comorbidity of eating disorder. Female gender and family history of mood disorder were significant predictors for suicide attempts. There was no difference between groups in terms of bipolar disorder subtype, onset age of bipolar disorder, total number of episodes, first and predominant episode type, suicide history in first degree relatives, severity of episodes, and hospitalization and being psychotic. Our study revealed that female gender, family history of mood disorder, and eating disorder are more frequent in bipolar patients with at least one suicide attempt.

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

ERIC Educational Resources Information Center

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

2008-01-01

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

The Utility of Low-Dose Aripiprazole for the Treatment of Bipolar II and Bipolar NOS Depression.

PubMed

Kelly, Tammas; Lieberman, Daniel Z

2017-02-01

Despite initial reports of efficacy in bipolar depression, multicenter trials did not show aripiprazole to be better than placebo, possibly because the doses used were too high, leading to lower efficacy and high dropout rates. This study evaluated the effects of low-dose aripiprazole. Extensive clinical experience has suggested that doses beyond 5 mg are rarely efficacious. Data were gathered from patients with bipolar II or bipolar not otherwise specified depression using a retrospective chart review. Efficacy was assessed with the Clinical Global Impression-Improvement score. Patients who had at least 2 trials of aripiprazole were included in a retrospective off-on-off-on experimental design. All patients were on other medications when aripiprazole was started. Patients were treated with doses of 1 to 5 mg. On average, patients were rated improved or very much improved compared with baseline. Sixteen of 211 patients worsened or experienced no change. Forty-four patients (21%) discontinued due to adverse effects. The group of patients who underwent off-on-off-on trials experienced statistically significant improvement when they started and restarted aripiprazole, and statistically significant worsening when they discontinued it. When treating bipolar II or bipolar not otherwise specified depression, low doses of aripiprazole, 5 mg or less, may be more effective and better tolerated than higher ones. Clinicians should start treatment with a very low dose and give patients time to respond.

Flexible Proton-Gated Oxide Synaptic Transistors on Si Membrane.

PubMed

Zhu, Li Qiang; Wan, Chang Jin; Gao, Ping Qi; Liu, Yang Hui; Xiao, Hui; Ye, Ji Chun; Wan, Qing

2016-08-24

Ion-conducting materials have received considerable attention for their applications in fuel cells, electrochemical devices, and sensors. Here, flexible indium zinc oxide (InZnO) synaptic transistors with multiple presynaptic inputs gated by proton-conducting phosphorosilicate glass-based electrolyte films are fabricated on ultrathin Si membranes. Transient characteristics of the proton gated InZnO synaptic transistors are investigated, indicating stable proton-gating behaviors. Short-term synaptic plasticities are mimicked on the proposed proton-gated synaptic transistors. Furthermore, synaptic integration regulations are mimicked on the proposed synaptic transistor networks. Spiking logic modulations are realized based on the transition between superlinear and sublinear synaptic integration. The multigates coupled flexible proton-gated oxide synaptic transistors may be interesting for neuroinspired platforms with sophisticated spatiotemporal information processing.

Clinical, Demographic, and Familial Correlates of Bipolar Spectrum Disorders among Offspring of Parents with Bipolar Disorder

ERIC Educational Resources Information Center

Goldstein, Benjamin I.; Shamseddeen, Wael; Axelson, David A.; Kalas, Cathy; Monk, Kelly; Brent, David A.; Kupfer, David J.; Birmaher, Boris

2010-01-01

Objective: Despite increased risk, most offspring of parents with bipolar disorder (BP) do not manifest BP. The identification of risk factors for BP among offspring could improve preventive and treatment strategies. We examined this topic in the Pittsburgh Bipolar Offspring Study (BIOS). Method: Subjects included 388 offspring, ages 7-17 years,…

Precursors in adolescence of adult-onset bipolar disorder.

PubMed

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.

Use of Stimulants in Bipolar Disorder.

PubMed

Perugi, Giulio; Vannucchi, Giulia; Bedani, Fulvio; Favaretto, Ettore

2017-01-01

Several international guidelines indicate stimulants, including methylphenidate (MPH), amphetamines and derivatives, modafinil, and armodafinil among the second-third-line choices for bipolar depression. Efficacy of stimulants has been also reported for the management of residual depressive symptoms such as fatigue and sleepiness and for the management of affective, cognitive, and behavioral symptoms in children and adult bipolar patients with comorbid ADHD. Few case reports show positive results with MPH in the treatment of resistant mania. Finally, MPH might be an option in some bipolar forms observed in psychiatric presentations of frontotemporal dementia and traumatic brain injury. In spite of these preliminary observations, the use of stimulants in bipolar patients is still controversial. Potential of misuse and abuse and mood destabilization with induction of (hypo)manic switches, mixed states, and rapid cycling are the concerns most frequently reported. Our aims are to summarize available literature on this topic and discuss practical management implications.

Proton Damage Effects on Carbon Nanotube Field-Effect Transistors

DTIC Science & Technology

2014-06-19

PROTON DAMAGE EFFECTS ON CARBON NANOTUBE FIELD-EFFECT TRANSISTORS THESIS Evan R. Kemp, Ctr...United States. AFIT-ENP-T-14-J-39 PROTON DAMAGE EFFECTS ON CARBON NANOTUBE FIELD-EFFECT TRANSISTORS THESIS Presented to...PROTON DAMAGE EFFECTS ON CARBON NANOTUBE FIELD-EFFECT TRANSISTORS Evan R. Kemp, BS Ctr, USAF Approved: // Signed

A nanoscale piezoelectric transformer for low-voltage transistors.

PubMed

Agarwal, Sapan; Yablonovitch, Eli

2014-11-12

A novel piezoelectric voltage transformer for low-voltage transistors is proposed. Placing a piezoelectric transformer on the gate of a field-effect transistor results in the piezoelectric transformer field-effect transistor that can switch at significantly lower voltages than a conventional transistor. The piezoelectric transformer operates by using one piezoelectric to squeeze another piezoelectric to generate a higher output voltage than the input voltage. Multiple piezoelectrics can be used to squeeze a single piezoelectric layer to generate an even higher voltage amplification. Coupled electrical and mechanical modeling in COMSOL predicts a 12.5× voltage amplification for a six-layer piezoelectric transformer. This would lead to more than a 150× reduction in the power needed for communications.

The use of bipolar technology in hysteroscopy.

PubMed

Calabrese, Stefania; DE Alberti, Davide; Garuti, Giancarlo

2016-04-01

Bipolar technology was introduced in the hysteroscopic clinical use in 1999, by the design of both loop electrodes addressed to resectoscopic surgery and miniaturized electrodes adaptable to small-size hysteroscopes. The need of an electrolytic solution as distension medium and the spatial relationships between the active and return bipolar electrode avoid, by definition, the risks of severe electrolyte imbalance syndromes and unpredictable electrical burns, sometimes complicating monopolar surgery. The true revolution in the hysteroscopy care has achieved through the availability of mini-hysteroscopes not requiring cervical dilatation, thus limiting uterine wall damages and allowing surgeons to manage several endometrial pathologies by mini-invasive procedures using an effective electrosurgical bipolar instrumentation. Many surgical interventions, traditionally accomplished by the resectoscope in a surgical room theatre, can be now carried out in an outpatient setting without any support from anesthesia. The patients' avoidance of surgical room access and the quick return to daily activities lead to an obvious - but not fully demonstrated - improvement in the medical and social costs associated to outpatient operative hysteroscopy. In the field of resectoscopy, bipolar electrodes are clinically as effective as monopolar devices. Randomized trials showed that bipolar resectoscopic technology prevents the electrolyte imbalance observed after monopolar surgery. However, in daily clinical practice the assumedly safer profile of bipolar with respect to monopolar resectoscopy has not been demonstrated yet.

Mathematical models of bipolar disorder

NASA Astrophysics Data System (ADS)

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

2009-07-01

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

HBT-EP Program: MHD Dynamics and Active Control through 3D Fields and Currents

NASA Astrophysics Data System (ADS)

Navratil, G. A.; Bialek, J.; Brooks, J. W.; Byrne, P. J.; Desanto, S.; Levesque, J. P.; Mauel, M. E.; Stewart, I. G.; Hansen, C. J.

2017-10-01

The HBT-EP active mode control research program aims to: (i) advance understanding of the effects of 3D shaping on advanced tokamak fusion performance, (ii) resolve important MHD issues associated with disruptions, and (iii) measure and mitigate the effects of 3D scrape-off layer (SOL) currents through active and passive control of the plasma edge and conducting boundary structures. Comparison of kink mode structure and RMP response in circular versus diverted plasmas shows good agreement with DCON modeling. SOL current measurements have been used to study SOL current dynamics and current-sharing with the vacuum vessel wall during kink-mode growth and disruptions. A multi-chord extreme UV/soft X-ray array is being installed to provide detailed internal mode structure information. Internal local electrodes were used to apply local bias voltage at two radial locations to study the effect of rotation profile on MHD mode rotation and stability and radial current flow through the SOL. A GPU-based low latency control system using 96 inputs and 64 outputs to apply magnetic perturbations for active control of kink modes is extended to directly control the SOL currents for kink-mode control. An extensive array of SOL current monitors and edge drive electrodes are being installed for pioneering studies of helical edge current control. Supported by U.S. DOE Grant DE-FG02-86ER53222.

Anxiety, stress and perfectionism in bipolar disorder.

PubMed

Corry, Justine; Green, Melissa; Roberts, Gloria; Frankland, Andrew; Wright, Adam; Lau, Phoebe; Loo, Colleen; Breakspear, Michael; Mitchell, Philip B

2013-12-01

Previous reports have highlighted perfectionism and related cognitive styles as a psychological risk factor for stress and anxiety symptoms as well as for the development of bipolar disorder symptoms. The anxiety disorders are highly comorbid with bipolar disorder but the mechanisms that underpin this comorbidity are yet to be determined. Measures of depressive, (hypo)manic, anxiety and stress symptoms and perfectionistic cognitive style were completed by a sample of 142 patients with bipolar disorder. Mediation models were used to explore the hypotheses that anxiety and stress symptoms would mediate relationships between perfectionistic cognitive styles, and bipolar disorder symptoms. Stress and anxiety both significantly mediated the relationship between both self-critical perfectionism and goal attainment values and bipolar depressive symptoms. Goal attainment values were not significantly related to hypomanic symptoms. Stress and anxiety symptoms did not significantly mediate the relationship between self-critical perfectionism and (hypo)manic symptoms. 1. These data are cross-sectional; hence the causality implied in the mediation models can only be inferred. 2. The clinic patients were less likely to present with (hypo)manic symptoms and therefore the reduced variability in the data may have contributed to the null findings for the mediation models with (hypo) manic symptoms. 3. Those patients who were experiencing current (hypo)manic symptoms may have answered the cognitive styles questionnaires differently than when euthymic. These findings highlight a plausible mechanism to understand the relationship between bipolar disorder and the anxiety disorders. Targeting self-critical perfectionism in the psychological treatment of bipolar disorder when there is anxiety comorbidity may result in more parsimonious treatments. © 2013 Published by Elsevier B.V.

Bipolar postpartum depression: An update and recommendations.

PubMed

Sharma, Verinder; Doobay, Minakshi; Baczynski, Christine

2017-09-01

Over the past few years there has been a surge of interest in the study of bipolar postpartum depression (PPD); however, questions remain about its prevalence, screening, clinical features, and treatment. Three electronic databases, MEDLINE/PubMed (1966-2016), PsycINFO (1806-2016), and the Cochrane Database of Systematic Reviews, were searched using a combination of the keywords bipolar, depression, postpartum, peripartum, prevalence, screening, diagnosis, treatment, drugs, and psychotherapy. The reference lists of articles identified were also searched. All relevant articles published in English were included. Depending on the population studied, 21.4-54% of women with PPD have a diagnosis of bipolar disorder (BD). Characteristic clinical features include younger age at illness onset, first onset of depression after childbirth, onset immediately after delivery, atypical depressive symptoms, psychotic features, mixed features, and history of BD in first-degree family members. Treatment should be guided by symptom acuity, safety concerns, the patient's response to past treatments, drug tolerability, and breastfeeding preference. In the absence of controlled treatment data, preference should be given to drugs normally indicated for bipolar depression including lithium, quetiapine and lamotrigine. Although antidepressants have been studied in combination with mood stabilizers in bipolar depression, these drugs should be avoided due to likelihood of elevated risk of induction of manic symptoms in the postpartum period. In the postpartum period, bipolar PPD is common, can be differentiated from unipolar PPD, and needs to be identified promptly in order to expedite appropriate treatment. Future studies on pharmacotherapy and psychotherapy should focus on the acute and preventative treatment of bipolar PPD. Copyright © 2017 Elsevier B.V. All rights reserved.

Regulation of glycogen synthase kinase-3 during bipolar mania treatment.

PubMed

Li, Xiaohong; Liu, Min; Cai, Zhuoji; Wang, Gang; Li, Xiaohua

2010-11-01

Bipolar disorder is a debilitating psychiatric illness presenting with recurrent mania and depression. The pathophysiology of bipolar disorder is poorly understood, and molecular targets in the treatment of bipolar disorder remain to be identified. Preclinical studies have suggested that glycogen synthase kinase-3 (GSK3) is a potential therapeutic target in bipolar disorder, but evidence of abnormal GSK3 in human bipolar disorder and its response to treatment is still lacking. This study was conducted in acutely ill type I bipolar disorder subjects who were hospitalized for a manic episode. The protein level and the inhibitory serine phosphorylation of GSK3 in peripheral blood mononuclear cells of bipolar manic and healthy control subjects were compared, and the response of GSK3 to antimanic treatment was evaluated. The levels of GSK3α and GSK3β in this group of bipolar manic subjects were higher than healthy controls. Symptom improvement during an eight-week antimanic treatment with lithium, valproate, and atypical antipsychotics was accompanied by a significant increase in the inhibitory serine phosphorylation of GSK3, but not the total level of GSK3, whereas concomitant electroconvulsive therapy treatment during a manic episode appeared to dampen the response of GSK3 to pharmacological treatment. Results of this study suggest that GSK3 can be modified during the treatment of bipolar mania. This finding in human bipolar disorder is in agreement with preclinical data suggesting that inhibition of GSK3 by increasing serine phosphorylation is a response of GSK3 to psychotropics used in bipolar disorder, supporting the notion that GSK3 is a promising molecular target in the pharmacological treatment of bipolar disorder. © 2010 John Wiley and Sons A/S.

Hypnotic susceptibility and affective states in bipolar I and II disorders.

PubMed

Zhang, Bingren; Wang, Jiawei; Zhu, Qisha; Ma, Guorong; Shen, Chanchan; Fan, Hongying; Wang, Wei

2017-11-09

Highly hypnotizable individuals have impaired executive function, elevated motor impulsivity and increased emotional sensitivity, which are sometimes found in bipolar disorder patients. It is then reasonable to assume that certain aspects of hypnotic susceptibility differ with the types of bipolar disorder. The Stanford Hypnotic Susceptibility Scale: Form C (SHSS:C) test, the Mood Disorder Questionnaire (MDQ), the Hypomanic Checklist-32 (HCL-32) and the Plutchick-van Praag Depression Inventory (PVP) were applied to 62 patients with bipolar I disorder, 33 bipolar II disorder, and 120 healthy volunteers. The passing rate of the SHSS:C 'Moving hands apart' item was higher in bipolar I patients than in controls, whereas for 'Mosquito hallucination' the rate was lower. Bipolar I and II patients scored significantly higher on MDQ, HCL-32 and PVP scales than controls. The passing rates of 'Mosquito hallucination' in controls, 'Arm rigidity' in bipolar I, and 'Age regression' in bipolar II predicted the respective MDQ scores. In contrast to cognitive suggestions, bipolar I patients followed motor suggestions more often under hypnosis. Furthermore, both bipolar disorder patients and healthy volunteers demonstrated associations between mania levels and certain hypnotic susceptibility features. Our study aids in better understanding the altered conscious states in bipolar disorders, and encourages the use of related psychotherapy for these patients.

[Pediatric bipolar disorder - case report of a bipolar patient with disease onset in childhood and adolescence: implications for diagnosis and therapy].

PubMed

Lackner, N; Birner, A; Bengesser, S A; Reininghaus, B; Kapfhammer, H P; Reininghaus, E

2014-11-01

In recent years, intense controversies have evolved about the existence and exact diagnostic criteria of pediatric bipolar affective disorder. The present study aims to discuss pediatric bipolar affective disorder based on the current literature focussing on the diagnostic prospects. Based on a case study, a process of bipolar disorder developed in childhood is depicted exemplarily. Because of the high comorbidity and overlapping symptoms of paediatric bipolar affective disorder and other psychiatric disorders, the major impact of the differential diagnosis has to be stressed. An early diagnosis and the treatment possibilities are discussed. © Georg Thieme Verlag KG Stuttgart · New York.

Modeling MHD Equilibrium and Dynamics with Non-Axisymmetric Resistive Walls in LTX and HBT-EP

NASA Astrophysics Data System (ADS)

Hansen, C.; Levesque, J.; Boyle, D. P.; Hughes, P.

2017-10-01

In experimental magnetized plasmas, currents in the first wall, vacuum vessel, and other conducting structures can have a strong influence on plasma shape and dynamics. These effects are complicated by the 3D nature of these structures, which dictate available current paths. Results from simulations to study the effect of external currents on plasmas in two different experiments will be presented: 1) The arbitrary geometry, 3D extended MHD code PSI-Tet is applied to study linear and non-linear plasma dynamics in the High Beta Tokamak (HBT-EP) focusing on toroidal asymmetries in the adjustable conducting wall. 2) Equilibrium reconstructions of the Lithium Tokamak eXperiment (LTX) in the presence of non-axisymmetric eddy currents. An axisymmetric model is used to reconstruct the plasma equilibrium, using the PSI-Tri code, along with a set of fixed 3D eddy current distributions in the first wall and vacuum vessel [C. Hansen et al., PoP Apr. 2017]. Simulations of detailed experimental geometries are enabled by use of the PSI-Tet code, which employs a high order finite element method on unstructured tetrahedral grids that are generated directly from CAD models. Further development of PSI-Tet and PSI-Tri will also be presented. This work supported by US DOE contract DE-SC0016256.

Social influences on bipolar affective disorders.

PubMed

Ramana, R; Bebbington, P

1995-07-01

The impact of psychosocial adversity on the onset and course of bipolar disorder has been assessed in studies that have relied on methods of eliciting life event histories and evaluating family atmosphere. The results of life event studies have been inconsistent, perhaps because the relationship between bipolar disorder and major stress is only pronounced in first or early episodes. If this is so, this phenomenon itself invites explanation, whether in social or biological terms. The two studies to data of family atmosphere suggest an association between high expressed emotion and relapse. The relationship between psychosocial stress and bipolar disorder requires further and more detailed research.

Electrochemical doping for lowering contact barriers in organic field effect transistors

PubMed Central

Schaur, Stefan; Stadler, Philipp; Meana-Esteban, Beatriz; Neugebauer, Helmut; Serdar Sariciftci, N.

2012-01-01

By electrochemically p-doping pentacene in the vicinity of the source-drain electrodes in organic field effect transistors the injection barrier for holes is decreased. The focus of this work is put on the influence of the p-doping process on the transistor performance. Cyclic voltammetry performed on a pentacene based transistor exhibits a reversible p-doping response. This doped state is evoked at the transistor injection electrodes. An improvement is observed when comparing transistor characteristics before and after the doping process apparent by an improved transistor on-current. This effect is reflected in the analysis of the contact resistances of the devices. PMID:23483101

High current gain transistor laser

PubMed Central

Liang, Song; Qiao, Lijun; Zhu, Hongliang; Wang, Wei

2016-01-01

A transistor laser (TL), having the structure of a transistor with multi-quantum wells near its base region, bridges the functionality gap between lasers and transistors. However, light emission is produced at the expense of current gain for all the TLs reported up to now, leading to a very low current gain. We propose a novel design of TLs, which have an n-doped InP layer inserted in the emitter ridge. Numerical studies show that a current flow aperture for only holes can be formed in the center of the emitter ridge. As a result, the common emitter current gain can be as large as 143.3, which is over 15 times larger than that of a TL without the aperture. Besides, the effects of nonradiative recombination defects can be reduced greatly because the flow of holes is confined in the center region of the emitter ridge. PMID:27282466

Neuropsychological Impairments in Schizophrenia and Psychotic Bipolar Disorder: Findings from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) Study

PubMed Central

Hill, S. Kristian; Reilly, James L.; Keefe, Richard S.E.; Gold, James M.; Bishop, Jeffrey R.; Gershon, Elliot S.; Tamminga, Carol A.; Pearlson, Godfrey D.; Keshavan, Matcheri S.; Sweeney, John A.

2017-01-01

Objective Familial neuropsychological deficits are well established in schizophrenia but remain less well characterized in other psychotic disorders. This study from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) consortium 1) compares cognitive impairment in schizophrenia and bipolar disorder with psychosis, 2) tests a continuum model of cognitive dysfunction in psychotic disorders, 3) reports familiality of cognitive impairments across psychotic disorders, and 4) evaluates cognitive impairment among nonpsychotic relatives with and without cluster A personality traits. Method Participants included probands with schizophrenia (N=293), psychotic bipolar disorder (N=227), schizoaffective disorder (manic, N=110; depressed, N=55), their first-degree relatives (N=316, N=259, N=133, and N=64, respectively), and healthy comparison subjects (N=295). All participants completed the Brief Assessment of Cognition in Schizophrenia (BACS) neuropsychological battery. Results Cognitive impairments among psychotic probands, compared to healthy comparison subjects, were progressively greater from bipolar disorder (z=−0.77) to schizoaffective disorder (manic z=−1.08; depressed z=−1.25) to schizophrenia (z=−1.42). Profiles across subtests of the BACS were similar across disorders. Familiality of deficits was significant and comparable in schizophrenia and bipolar disorder. Of particular interest were similar levels of neuropsychological deficits in relatives with elevated cluster A personality traits across proband diagnoses. Nonpsychotic relatives of schizophrenia probands without these personality traits exhibited significant cognitive impairments, while relatives of bipolar probands did not. Conclusions Robust cognitive deficits are present and familial in schizophrenia and psychotic bipolar disorder. Severity of cognitive impairments across psychotic disorders was consistent with a continuum model, in which more prominent affective features and less

Family planning for women with bipolar disorder.

PubMed

Packer, S

1992-05-01

Women with bipolar disorder often ask their treating clinician for information about family planning, as they are concerned about the impact of their illness on offspring. Three areas that should be included in discussions with patients and their partners are heritability of the disorder, risks during pregnancy, and risks during the postpartum period. The author summarizes information about genetic transmission of bipolar disorder, effects on bipolar patients of stress associated with pregnancy and childrearing, and effects of medication on the fetus and newborn. Discussion of these issues is most relevant for a women patient who is planning a pregnancy, but may also be useful for couples before marriage, for a women patient who finds that she is pregnant, and for men with bipolar disorder who want to become fathers.

Bipolar Disorder in School-Age Children

ERIC Educational Resources Information Center

Olson, Patricia M.; Pacheco, Mary Rae

2005-01-01

This article examines the individual components of bipolar disorder in children and the behaviors that can escalate as a result of misdiagnosis and treatment. The brain/behavior relationship in bipolar disorders can be affected by genetics, developmental failure, or environmental influences, which can cause an onset of dramatic mood swings and…

Liquid crystals for organic transistors (Conference Presentation)

NASA Astrophysics Data System (ADS)

Hanna, Jun-ichi; Iino, Hiroaki

2016-09-01

Liquid crystals are a new type of organic semiconductors exhibiting molecular orientation in self-organizing manner, and have high potential for device applications. In fact, various device applications have been proposed so far, including photosensors, solar cells, light emitting diodes, field effect transistors, and so on.. However, device performance in those fabricated with liquid crystals is less than those of devices fabricated with conventional materials in spite of unique features of liquid crystals. Here we discuss how we can utilize the liquid crystallinity in organic transistors and how we can overcome conventional non-liquid crystalline organic transistor materials. Then, we demonstrate high performance organic transistors fabricated with a smectic E liquid crystal of Ph-BTBT-10, which show high mobility of over 10cm2/Vs and high thermal durability of over 200oC in OFETs fabricated with its spin-coated polycrystalline thin films.

Review of Evidence for Use of Antidepressants in Bipolar Depression

PubMed Central

McInerney, Shane J.

2014-01-01

Objective: Depressive episodes predominate over the course of bipolar disorder and cause considerable functional impairment. Antidepressants are frequently prescribed in the treatment of bipolar depression, despite concerns about efficacy and risk of switching to mania. This review provides a critical examination of the evidence for and against the use of antidepressants in bipolar depression. Data Sources: English-language peer-reviewed literature and evidence-based guidelines published between January 1, 1980, and March 2014, were identified using PubMed, MEDLINE, PsycINFO/PsycLIT, and EMBASE. All searches contained the terms antidepressants, bipolar depression, depressive episodes in bipolar disorder, and treatment guidelines for bipolar depression. Meta-analyses, randomized controlled trials, systematic reviews, and practice guidelines were included. Bibliographies from these publications were used to identify additional articles of interest. Data Extraction: Studies involving treatment of bipolar depression with antidepressant monotherapy, adjunctive use of antidepressant with a mood stabilizer, and meta-analysis of such studies combined were reviewed. Conclusions: The body of evidence on the use of antidepressant monotherapy to treat patients with bipolar depression is contentious, but the recommendations from evidence-based guidelines do not support antidepressant monotherapy for bipolar depression. Only when mood stabilizer or atypical antipsychotic monotherapy has failed should adjunctive treatment with an antidepressant be considered. PMID:25667812

The electrolysis time on electrosynthesis of hydroxyapatite with bipolar membrane

NASA Astrophysics Data System (ADS)

Nur, Adrian; Jumari, Arif; Budiman, Anatta Wahyu; Puspitaningtyas, Stella Febianti; Cahyaningrum, Suci; Nazriati, Nazriati; Fajaroh, Fauziatul

2018-02-01

The electrochemical method with bipolar membrane has been successfully used for the synthesis of hydroxyapatite. In this work, we have developed 2 chambers electrolysis system separated by a bipolar membrane. The membrane was used to separate cations (H+ ions produced by the oxidation of water at the anode) and anions (OH- ions produced by the reduction of water at the cathode). With this system, we have designed that OH- ions still stay in the anions chamber because OH- ions was very substantial in the hydroxyapatite particles formation. The aim of this paper was to compare the electrolysis time on electrosynthesis of hydroxyapatite with and without the bipolar membrane. The electrosynthesis was performed at 500 mA/cm2 for 0.5 to 2 hours at room temperature and under ultrasonic cleaner to void agglomeration with and without the bipolar membrane. The electrosynthesis of hydroxyapatite with the bipolar membrane more effective than without the bipolar membrane. The hydroxyapatite has been appeared at 0.5 h of the electrolysis time with the bipolar membrane (at the cathode chamber) while it hasn't been seen without the bipolar membrane. The bipolar membrane prevents OH- ions migrate to the cation chamber. The formation of HA becomes more effective because OH- ions just formed HA particle.

Identifying early indicators in bipolar disorder: a qualitative study.

PubMed

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.

Transistor circuit increases range of logarithmic current amplifier

NASA Technical Reports Server (NTRS)

Gilmour, G.

1966-01-01

Circuit increases the range of a logarithmic current amplifier by combining a commercially available amplifier with a silicon epitaxial transistor. A temperature compensating network is provided for the transistor.

Changes in mood stabilizer prescription patterns in bipolar disorder.

PubMed

Karanti, Alina; Kardell, Mathias; Lundberg, Ulrika; Landén, Mikael

2016-05-01

Lithium is a first line treatment option in bipolar disorder, but several alternative treatments have been introduced in recent years, such as antiepileptic and atypical antipsychotic drugs. Little is known about how this has changed the prescription patterns. We investigated possible changes in the use of mood stabilizers and antidepressants in Sweden during 2007-2013. Data was collected from Swedish registers: the National Quality Assurance Register for bipolar disorder (BipoläR), the Prescribed Drug Register, and the Patient Register. Logistic regression models with drug use as outcomes were used to adjust for confounding factors such as sex, age, year of registration, and subtypes of bipolar disorder. In both bipolar subtypes, lithium use decreased steadily during the study period, while the use of lamotrigine and quetiapine increased. The use of valproate decreased in bipolar II disorder and the use of olanzapine decreased among women. The use of antidepressant remained principally unchanged but increased somewhat in bipolar I disorder. We only report data from 2007 as the coverage of BipoläR prior to 2007 was too low to allow for reliable analyses. Significant changes in the prescription of drugs in the treatment of bipolar disorder have occurred in recent years in Sweden. Further studies are needed to clarify whether these changes alter the outcome in bipolar disorder. Copyright © 2016 Elsevier B.V. All rights reserved.

[Drug Abuse Comorbidity in Bipolar Disorder].

PubMed

Ortiz, Óscar Medina

2012-06-01

Drug use among patients with bipolar disorder is greater than the one observed in the general population; psychotic episodes are likely to occur after consumption. This has implications in the prevention, etiology, management, and treatment of the disease. Bipolar disorder pathology is likely to have positive response to pharmacological treatment. Therefore, identifying the strategies with better results to be applied in these patients is fundamental for psychiatrists and primary care physicians. Review literature in order to determine the prevalence and characteristics of drug abuse in patients with bipolar disorder and establish the pharmacological strategies that have produced better results. Literature review. A great variety of studies demonstrate the relationship between bipolar disorder and drug use disorder. These patients are hospitalized more frequently, have an earlier onset of the disease, and present a larger number of depressive episodes and suicide attempts which affect the course of the disease. The drug with better results in the treatment of these patients is Divalproate. Satisfactory results have been also obtained with other mood stabilizers such as carbamazepine, lamotrigine, and the antipsychotic aripiprazole. Substance abuse is present in a large number of patients with bipolar disorder. The Divalproate is the drug that has shown better results in the studies. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Dysfunctional Cognitions among Offspring of Individuals with Bipolar Disorder.

PubMed

Ruggero, Camilo J; Bain, Kathleen M; Smith, Patrick M; Kilmer, Jared N

2015-07-01

Individuals with bipolar disorder often endorse dysfunctional beliefs consistent with cognitive models of bipolar disorder (Beck, 1976; Mansell, 2007). The present study sought to assess whether young adult offspring of those with bipolar disorder would also endorse these beliefs, independent of their own mood episode history. Participants (N = 89) were young adult college students with a parent with bipolar disorder (n = 27), major depressive disorder (MDD; n = 30), or no mood disorder (n = 32). Semi-structured interviews of the offspring were used to assess diagnoses. Dysfunctional beliefs related to Beck and colleagues' (2006) and Mansell's (2007) cognitive models were assessed. Unlike offspring of parents with MDD or no mood disorder, those with a parent with bipolar disorder endorsed significantly more dysfunctional cognitions associated with extreme appraisal of mood states, even after controlling for their own mood diagnosis. Once affected by a bipolar or depressive disorder, offspring endorsed dysfunctional cognitions across measures. Dysfunctional cognitions, particularly those related to appraisals of mood states and their potential consequences, are evident in young adults with a parent who has bipolar disorder and may represent targets for psychotherapeutic intervention.

Thin co-radial bipolar leads: technology and clinical performance.

PubMed

Fahraeus, T; Israel, C W; Wöllenstein, M

2001-09-01

While bipolar leads offer advantages such as better sensing performance than unipolar leads, their use has been limited by a larger lead diameter and reports about a high failure rate of several bipolar lead models. This has led to the development of thin bipolar leads using a special technology which aims at improving lead safety. Leads with monofilar thin conductors (drawn filled tube) which are individually coated with a very resistant material (ETFE) have been developed. Using a co-radial instead of co-axial bipolar conductor design, the lead diameter could be reduced to 4.5 F compared to 6-7 F of conventional bipolar leads. Bench testing demonstrated a significant improvement of this lead technology with respect to degradation of insulation material by biochemically reactive solutions. Also mechanical characteristics such as resistance to tearing forces and compression showed a high lead durability. From our own experience, co-radial bipolar leads show a favorable electrical performance with the exception of a relatively low pacing impedance. Also during long-term follow-up, the rate of lead failure was very low. These findings are corroborated by other clinical studies which also demonstrated good handling characteristics of thin bipolar leads during implantation.

Stretchable transistors with buckled carbon nanotube films as conducting channels

DOEpatents

Arnold, Michael S; Xu, Feng

2015-03-24

Thin-film transistors comprising buckled films comprising carbon nanotubes as the conductive channel are provided. Also provided are methods of fabricating the transistors. The transistors, which are highly stretchable and bendable, exhibit stable performance even when operated under high tensile strains.

Metal nanoparticle film-based room temperature Coulomb transistor.

PubMed

Willing, Svenja; Lehmann, Hauke; Volkmann, Mirjam; Klinke, Christian

2017-07-01

Single-electron transistors would represent an approach to developing less power-consuming microelectronic devices if room temperature operation and industry-compatible fabrication were possible. We present a concept based on stripes of small, self-assembled, colloidal, metal nanoparticles on a back-gate device architecture, which leads to well-defined and well-controllable transistor characteristics. This Coulomb transistor has three main advantages. By using the scalable Langmuir-Blodgett method, we combine high-quality chemically synthesized metal nanoparticles with standard lithography techniques. The resulting transistors show on/off ratios above 90%, reliable and sinusoidal Coulomb oscillations, and room temperature operation. Furthermore, this concept allows for versatile tuning of the device properties such as Coulomb energy gap and threshold voltage, as well as period, position, and strength of the oscillations.

Organic field effect transistor with ultra high amplification

NASA Astrophysics Data System (ADS)

Torricelli, Fabrizio

2016-09-01

High-gain transistors are essential for the large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show organic transistors fabricated on plastic foils enabling unipolar amplifiers with ultra-gain. The proposed approach is general and opens up new opportunities for ultra-large signal amplification in organic circuits and sensors.

Cross-national prevalence and cultural correlates of bipolar I disorder.

PubMed

Johnson, Kaja R; Johnson, Sheri L

2014-07-01

Bipolar disorder has been consistently related to heightened sensitivity to reward. Greater reward sensitivity predicts the onset of disorder, a more severe course, and conversion from milder to severe forms. No studies consider whether cultural factors related to reward sensitivity influence the course of bipolar disorder. This study examines the relationship of reward-relevant cultural values to global prevalence rates of bipolar I disorder. Lifetime prevalence of bipolar I disorder for 17 countries was drawn from epidemiological studies that used structured diagnostic interviews of large community samples. Bivariate correlations were used to assess the relationship of bipolar disorder prevalence with national scores on four reward-relevant cultural dimensions (Power Distance, Individualism, Long-Term Orientation, and Performance Orientation). The prevalence of bipolar I disorder was correlated in the predicted manner with Power Distance and Individualism, and with Long-Term Orientation and Performance Orientation after outliers were removed. Findings provide evidence for a cultural model of reward sensitivity in bipolar disorder.

Bipolar batteries based on Ebonex ® technology

NASA Astrophysics Data System (ADS)

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

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

Design concepts of high power bipolar rechargeable lithium battery

NASA Technical Reports Server (NTRS)

Shen, David H.; Halpert, Gerald

1993-01-01

The present study shows that current bipolar Li/TiS2 batteries using a 0.38 mm thick TiS2 bipolar plate can yield moderate specific power and also high specific energy battery. The computer design studies project that a 100 V, 10 A h bipolar Li/TiS2 battery can achieve 150 W h/kg, 210 W h/l, and 150 W/kg. The unoptimized experimental bipolar Li/TiS2 batteries (3 cells, 90 mA h) exhibited 47 W h/kg, 90 W h/l, and 140 W/kg. Preliminary results on the cycleability of the bipolar batteries are demonstrated. The results also show that enhanced rate capability can be achieved by using pulse discharge and longer rest period between pulses.

Understanding and control of bipolar self-doping in copper nitride

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fioretti, Angela N., E-mail: afiorett@mines.edu, E-mail: riy.zakutayev@nrel.gov; Tamboli, Adele C.; Caskey, Christopher M.

2016-05-14

Semiconductor materials that can be doped both n-type and p-type are desirable for diode-based applications and transistor technology. Copper nitride (Cu{sub 3}N) is a metastable semiconductor with a solar-relevant bandgap that has been reported to exhibit bipolar doping behavior. However, deeper understanding and better control of the mechanism behind this behavior in Cu{sub 3}N is currently lacking in the literature. In this work, we use combinatorial growth with a temperature gradient to demonstrate both conduction types of phase-pure, sputter-deposited Cu{sub 3}N thin films. Room temperature Hall effect and Seebeck effect measurements show n-type Cu{sub 3}N with 10{sup 17} electrons/cm{sup 3}more » for low growth temperature (≈35 °C) and p-type with 10{sup 15} holes/cm{sup 3}–10{sup 16} holes/cm{sup 3} for elevated growth temperatures (50 °C–120 °C). Mobility for both types of Cu{sub 3}N was ≈0.1 cm{sup 2}/Vs–1 cm{sup 2}/Vs. Additionally, temperature-dependent Hall effect measurements indicate that ionized defects are an important scattering mechanism in p-type films. By combining X-ray absorption spectroscopy and first-principles defect theory, we determined that V{sub Cu} defects form preferentially in p-type Cu{sub 3}N, while Cu{sub i} defects form preferentially in n-type Cu{sub 3}N, suggesting that Cu{sub 3}N is a compensated semiconductor with conductivity type resulting from a balance between donor and acceptor defects. Based on these theoretical and experimental results, we propose a kinetic defect formation mechanism for bipolar doping in Cu{sub 3}N that is also supported by positron annihilation experiments. Overall, the results of this work highlight the importance of kinetic processes in the defect physics of metastable materials and provide a framework that can be applied when considering the properties of such materials in general.« less

Carrier mobility in organic field-effect transistors

NASA Astrophysics Data System (ADS)

Xu, Yong; Benwadih, Mohamed; Gwoziecki, Romain; Coppard, Romain; Minari, Takeo; Liu, Chuan; Tsukagoshi, Kazuhito; Chroboczek, Jan; Balestra, Francis; Ghibaudo, Gerard

2011-11-01

A study of carrier transport in top-gate and bottom-contact TIPS-pentacene organic field-effect transistors (OFETs) based on mobility is presented. Among three mobilities extracted by different methods, the low-field mobility obtained by the Y function exhibits the best reliability and ease for use, whereas the widely applied field-effect mobility is not reliable, particularly in short-channel transistors and at low temperatures. A detailed study of contact transport reveals its strong impact on short-channel transistors, suggesting that a more intrinsic transport analysis is better implemented in relatively longer-channel devices. The observed temperature dependences of mobility are well explained by a transport model with Gaussian-like diffusivity band tails, different from diffusion in localized states band tails. This model explicitly interprets the non-zero constant mobility at low temperatures and clearly demonstrates the effects of disorder and hopping transport on temperature and carrier density dependences of mobility in organic transistors.

Clinical features of bipolar spectrum with binge eating behaviour.

PubMed

McElroy, Susan L; Crow, Scott; Blom, Thomas J; Cuellar-Barboza, Alfredo B; Prieto, Miguel L; Veldic, Marin; Winham, Stacey J; Bobo, William V; Geske, Jennifer; Seymour, Lisa R; Mori, Nicole; Bond, David J; Biernacka, Joanna M; Frye, Mark A

2016-09-01

To determine whether bipolar spectrum disorder with binge eating behavior (BE) is an important clinical sub-phenotype. Prevalence rates and correlates of different levels of BE were assessed in 1114 bipolar spectrum patients participating in a genetic biobank. BE and eating disorders (EDs) were assessed with the Eating Disorder Diagnostic Scale (EDDS). Psychiatric illness burden was evaluated with measures of suicidality, psychosis, mood instability, anxiety disorder comorbidity, and substance abuse comorbidity. Medical illness burden was evaluated with body mass index (BMI) and the Cumulative Index Rating Scale (CIRS). Thirty percent of patients had any BE and 27% had BE plus an ED diagnosis. Compared with bipolar spectrum patients without BE, bipolar spectrum patients with BE were younger and more likely to be female; had significantly higher levels of eating psychopathology, suicidality, mood instability, and anxiety disorder comorbidity; had a significantly higher mean BMI and a significantly higher rate of obesity; and had a significantly higher medical illness burden. Bipolar spectrum patients with BE but no ED diagnosis were more similar to bipolar spectrum patients without BE than to those with an ED. Nonetheless, the positive predictive value and specificity of BE predicting an ED was 0.90 and 0.96, respectively. As only two patients had co-occurring anorexia nervosa, these results may not generalize to bipolar spectrum patients with restricting EDs. Bipolar spectrum disorder with broadly-defined BE may not be as clinically relevant a sub-phenotype as bipolar spectrum disorder with an ED but may be an adequate proxy for the latter when phenotyping large samples of individuals. Copyright © 2016. Published by Elsevier B.V.

Emotion in Bipolar I Disorder: Implications for Functional and Symptom Outcomes

PubMed Central

Johnson, Sheri L.; Tharp, Jordan A.; Peckham, Andrew D.; McMaster, Kaja J.

2015-01-01

Despite the centrality of emotion disturbance in neurobiological models of bipolar disorder, the behavioral literature has not yet clearly identified the most central aspects of emotion disturbance in bipolar disorder. Toward this aim, we gathered a battery of emotion-related measures in 67 persons diagnosed with bipolar I disorder as assessed with SCID and a well-matched control group of 58 persons without a history of mood disorders. Those with bipolar disorder were interviewed monthly until they achieved remission, and then tested on emotion measures. A subset of 36 participants with bipolar disorder completed symptom severity interviews at 12-month follow-up. Factor analyses indicated four emotion factor scores: Negative Emotion, Positive Emotion, Reappraisal and Suppression. Bivariate analyses suggested that bipolar disorder was tied to a host of emotion disturbances, but multivariate analyses suggested that bipolar disorder was particularly tied to elevations of Negative Emotion. High Negative Emotion, low Positive Emotion, and high Suppression were conjointly related to lower functioning. Reappraisal predicted declines in depression over time for those with bipolar disorder. Findings highlight the importance of considering the overall profile of emotion disturbance in bipolar disorder. Emotion and emotion regulation appear central to a broad range of outcomes in bipolar disorder. PMID:26480234

Safety and efficacy of quetiapine in bipolar depression.

PubMed

Bogart, Gregory T; Chavez, Benjamin

2009-11-01

To review the clinical data investigating the efficacy and safety of quetiapine in bipolar depression. Searches of MEDLINE and PubMed (1977-July 2009) were conducted using the key words quetiapine and bipolar depression. The references of literature found were cross-referenced. The pharmaceutical company that produces quetiapine was contacted to obtain the posters for the EMBOLDEN I and EMBOLDEN II trials. Only double-blind, placebo-controlled trials were included for review, as well as any subanalyses of the literature that matched this criterion. There was a total of 5 double-blind, placebo-controlled trials and 5 subanalyses reviewed. The results of these data demonstrated quetiapine's efficacy in the treatment of depressive phases of bipolar disorder, including statistically significant improvement in the Montgomery-Asberg Depression Rating Scale (MADRS). In the trials reviewed in this article, the change in MADRS scores ranged from -15.4 to -16.94 within the quetiapine groups, and from -10.26 to -11.93 in the placebo groups. There were also statistically significant improvements in the Hamilton Anxiety Rating Scale, the Short Form of the Quality of Life Enjoyment and Satisfaction Questionnaire, the Pittsburgh Sleep Quality Index, and the Sheehan Disability Scale. All of these trials had a duration of 8 weeks and therefore cannot be applied to the long-term use of quetiapine in bipolar depression. The most common adverse events were sedation, somnolence, and dry mouth. The overall dropout rates for the trials reviewed ranged from 24% to 47%. Based on the literature reviewed here, quetiapine appears to be a safe and efficacious short-term treatment option for bipolar depression. Patients with bipolar type I showed greater improvement on the MADRS than those with bipolar type II. Patients with a rapid-cycling disease course showed an improvement in depressive symptoms, regardless of bipolar type.

Personality Disorder Symptom Severity Predicts Onset of Mood Episodes and Conversion to Bipolar I Disorder in Individuals with Bipolar Spectrum Disorder

PubMed Central

Ng, Tommy H.; Burke, Taylor A.; Stange, Jonathan P.; Walshaw, Patricia D.; Weiss, Rachel B.; Urosevic, Snezana; Abramson, Lyn Y.; Alloy, Lauren B.

2017-01-01

Although personality disorders (PDs) are highly comorbid with bipolar spectrum disorders (BSDs), little longitudinal research has been conducted to examine the prospective impact of PD symptoms on the course of BSDs. The aim of this study is to examine whether PD symptom severity predicts shorter time to onset of bipolar mood episodes and conversion to bipolar I disorder over time among individuals with less severe BSDs. Participants (n = 166) with bipolar II disorder, cyclothymia, or bipolar disorder not otherwise specified completed diagnostic interview assessments of PD symptoms and self-report measures of mood symptoms at baseline. They were followed prospectively with diagnostic interviews every four months for an average of 3.02 years. Cox proportional hazard regression analyses indicated that overall PD symptom severity significantly predicted shorter time to onset of hypomanic (hazard ratio [HR]= 1.42; p < .001) and major depressive episodes (HR = 1.51; p < .001) and conversion to bipolar I disorder (HR = 2.51; p < .001), after controlling for mood symptoms. Results also suggested that cluster B severity predicted shorter time to onset of hypomanic episodes (HR = 1.38; p = .002) and major depressive episodes (HR = 1.35; p = .01) and conversion to bipolar I disorder (HR = 2.77; p < .001), whereas cluster C severity (HR= 1.56; p < .001) predicted shorter time to onset of major depressive episodes. These results support predisposition models in suggesting that PD symptoms may act as a risk factor for a more severe course of BSDs. PMID:28368159

[Differences in Subjective Experience Between Unipolar and Bipolar Depression].

PubMed

Fierro, Marco; Bustos, Andrés; Molina, Carlos

2016-01-01

It is important to make distinction between bipolar and unipolar depression because treatment and prognosis are different. Since the diagnosis of the two conditions is purely clinical, find symptomatic differences is useful. Find differences in subjective experience (first person) between unipolar and bipolar depression. Phenomenological-oriented qualitative exploratory study of 12 patients (7 with bipolar depression and 5 with unipolar depression, 3 men and 9 women). We used a semi-structured interview based on Examination of Anomalous Self-Experience (EASE). The predominant mood in bipolar depression is emotional dampening, in unipolar is sadness. The bodily experience in bipolar is of a heavy, tired body; an element that inserts between the desires of acting and performing actions and becomes an obstacle to the movement. In unipolar is of a body that feels more comfortable with the stillness than activity, like laziness of everyday life. Cognition and the stream of consciousness: in bipolar depression, compared with unipolar, thinking is slower, as if to overcome obstacles in their course. There are more difficult to understand what is heard or read. Future perspective: in bipolar depression, hopelessness is stronger and broader than in unipolar, as if the very possibility of hope was lost. Qualitative differences in predominant mood, bodily experience, cognition and future perspective were found between bipolar and unipolar depression. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Screening for bipolar disorders in Spanish-speaking populations: sensitivity and specificity of the Bipolar Spectrum Diagnostic Scale-Spanish Version.

PubMed

Vázquez, Gustavo Héctor; Romero, Ester; Fabregues, Fernando; Pies, Ronald; Ghaemi, Nassir; Mota-Castillo, Manuel

2010-01-01

Bipolar disorder is commonly misdiagnosed, perhaps more so in Latin American and Spanish-speaking populations than in the United States. The Bipolar Spectrum Diagnostic Scale (BSDS) is a 19-item screening instrument designed to assist in screening for all types of bipolar disorder. The authors investigated the sensitivity of a Spanish-language version of the BSDS in a cohort of 65 outpatients with a diagnosis of bipolar disorder, based on a semi-structured interview and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria. To determine specificity, we assessed a control group of 36 outpatients with diagnosis of unipolar major depressive disorder. The overall sensitivity of the BSDS Spanish version with bipolar disorders types I, II, and NOS was 0.70, which was slightly lower than the sensitivity in the study using the English version of the BSDS (0.76). The specificity was 0.89. When the threshold was decreased from 13 to 12, the sensitivity of the Spanish BSDS increased to 0.76 and specificity dropped to 0.81. The Spanish version of the BSDS is promising as a screening instrument in Spanish-speaking populations. Copyright 2010 Elsevier Inc. All rights reserved.

Wavelength-Division Multiplexing Of Bipolar Digital Signals

NASA Technical Reports Server (NTRS)

Gibbons, Ronnie D.; Ubele, John L., II

1994-01-01

In system, bipolar digital data transmitted by use of wavelength-division multiplexing on single optical fiber. Two different wavelengths used to transmit pulses signifying "positive" or "negative" bipolar digital data. Simultaneous absence of pulses at both wavelengths signifies digital "zero."

Enhanced neurocognitive functioning and positive temperament in twins discordant for bipolar disorder.

PubMed

Higier, Rachel G; Jimenez, Amy M; Hultman, Christina M; Borg, Jacqueline; Roman, Cristina; Kizling, Isabelle; Larsson, Henrik; Cannon, Tyrone D

2014-11-01

Based on evidence linking creativity and bipolar disorder, a model has been proposed whereby factors influencing liability to bipolar disorder confer certain traits with positive effects on reproductive fitness. The authors tested this model by examining key traits known to be associated with evolutionary fitness, namely, temperament and neurocognition, in individuals carrying liability for bipolar disorder. Schizophrenia probands and their co-twins were included as psychiatric controls. Twin pairs discordant for bipolar disorder and schizophrenia and control pairs were identified through the Swedish Twin Registry. The authors administered a neuropsychological test battery and temperament questionnaires to samples of bipolar probands, bipolar co-twins, schizophrenia probands, schizophrenia co-twins, and controls. Multivariate mixed-model analyses of variance were conducted to compare groups on temperament and neurocognitive scores. Bipolar co-twins showed elevated scores on a "positivity" temperament scale compared with controls and bipolar probands, while bipolar probands scored higher on a "negativity" scale compared with their co-twins and controls, who did not differ. Additionally, bipolar co-twins showed superior performance compared with controls on tests of verbal learning and fluency, while bipolar probands showed performance decrements across all neurocognitive domains. In contrast, schizophrenia co-twins showed attenuated impairments in positivity and overall neurocognitive functioning relative to their ill proband counterparts. These findings suggest that supra-normal levels of sociability and verbal functioning may be associated with liability for bipolar disorder. These effects were specific to liability for bipolar disorder and did not apply to schizophrenia. Such benefits may provide a partial explanation for the persistence of bipolar illness in the population.

A steep-slope transistor based on abrupt electronic phase transition

NASA Astrophysics Data System (ADS)

Shukla, Nikhil; Thathachary, Arun V.; Agrawal, Ashish; Paik, Hanjong; Aziz, Ahmedullah; Schlom, Darrell G.; Gupta, Sumeet Kumar; Engel-Herbert, Roman; Datta, Suman

2015-08-01

Collective interactions in functional materials can enable novel macroscopic properties like insulator-to-metal transitions. While implementing such materials into field-effect-transistor technology can potentially augment current state-of-the-art devices by providing unique routes to overcome their conventional limits, attempts to harness the insulator-to-metal transition for high-performance transistors have experienced little success. Here, we demonstrate a pathway for harnessing the abrupt resistivity transformation across the insulator-to-metal transition in vanadium dioxide (VO2), to design a hybrid-phase-transition field-effect transistor that exhibits gate controlled steep (`sub-kT/q') and reversible switching at room temperature. The transistor design, wherein VO2 is implemented in series with the field-effect transistor's source rather than into the channel, exploits negative differential resistance induced across the VO2 to create an internal amplifier that facilitates enhanced performance over a conventional field-effect transistor. Our approach enables low-voltage complementary n-type and p-type transistor operation as demonstrated here, and is applicable to other insulator-to-metal transition materials, offering tantalizing possibilities for energy-efficient logic and memory applications.

A steep-slope transistor based on abrupt electronic phase transition.

PubMed

Shukla, Nikhil; Thathachary, Arun V; Agrawal, Ashish; Paik, Hanjong; Aziz, Ahmedullah; Schlom, Darrell G; Gupta, Sumeet Kumar; Engel-Herbert, Roman; Datta, Suman

2015-08-07

Collective interactions in functional materials can enable novel macroscopic properties like insulator-to-metal transitions. While implementing such materials into field-effect-transistor technology can potentially augment current state-of-the-art devices by providing unique routes to overcome their conventional limits, attempts to harness the insulator-to-metal transition for high-performance transistors have experienced little success. Here, we demonstrate a pathway for harnessing the abrupt resistivity transformation across the insulator-to-metal transition in vanadium dioxide (VO2), to design a hybrid-phase-transition field-effect transistor that exhibits gate controlled steep ('sub-kT/q') and reversible switching at room temperature. The transistor design, wherein VO2 is implemented in series with the field-effect transistor's source rather than into the channel, exploits negative differential resistance induced across the VO2 to create an internal amplifier that facilitates enhanced performance over a conventional field-effect transistor. Our approach enables low-voltage complementary n-type and p-type transistor operation as demonstrated here, and is applicable to other insulator-to-metal transition materials, offering tantalizing possibilities for energy-efficient logic and memory applications.

Enhanced transconductance in a double-gate graphene field-effect transistor

NASA Astrophysics Data System (ADS)

Hwang, Byeong-Woon; Yeom, Hye-In; Kim, Daewon; Kim, Choong-Ki; Lee, Dongil; Choi, Yang-Kyu

2018-03-01

Multi-gate transistors, such as double-gate, tri-gate and gate-all-around transistors are the most advanced Si transistor structure today. Here, a genuine double-gate transistor with a graphene channel is experimentally demonstrated. The top and bottom gates of the double-gate graphene field-effect transistor (DG GFET) are electrically connected so that the conductivity of the graphene channel can be modulated simultaneously by both the top and bottom gate. A single-gate graphene field-effect transistor (SG GFET) with only the top gate is also fabricated as a control device. For systematical analysis, the transfer characteristics of both GFETs were measured and compared. Whereas the maximum transconductance of the SG GFET was 17.1 μS/μm, that of the DG GFET was 25.7 μS/μm, which is approximately a 50% enhancement. The enhancement of the transconductance was reproduced and comprehensively explained by a physics-based compact model for GFETs. The investigation of the enhanced transfer characteristics of the DG GFET in this work shows the possibility of a multi-gate architecture for high-performance graphene transistor technology.

Metal nanoparticle film–based room temperature Coulomb transistor

PubMed Central

Willing, Svenja; Lehmann, Hauke; Volkmann, Mirjam; Klinke, Christian

2017-01-01

Single-electron transistors would represent an approach to developing less power–consuming microelectronic devices if room temperature operation and industry-compatible fabrication were possible. We present a concept based on stripes of small, self-assembled, colloidal, metal nanoparticles on a back-gate device architecture, which leads to well-defined and well-controllable transistor characteristics. This Coulomb transistor has three main advantages. By using the scalable Langmuir-Blodgett method, we combine high-quality chemically synthesized metal nanoparticles with standard lithography techniques. The resulting transistors show on/off ratios above 90%, reliable and sinusoidal Coulomb oscillations, and room temperature operation. Furthermore, this concept allows for versatile tuning of the device properties such as Coulomb energy gap and threshold voltage, as well as period, position, and strength of the oscillations. PMID:28740864

Development and fabrication of improved power transistor switches

NASA Technical Reports Server (NTRS)

Hower, P. L.; Chu, C. K.

1979-01-01

A new class of high-voltage power transistors was achieved by adapting present interdigitated thyristor processing techniques to the fabrication of npn Si transistors. Present devices are 2.3 cm in diameter and have V sub CEO (sus) in the range of 400 to 600V. V sub CEO (sus) = 450V devices were made with an (h sub FE)(I sub C) product of 900A at V sub CE = 2.5V. The electrical performance obtained was consistent with the predictions of an optimum design theory specifically developed for power switching transistors. The device design, wafer processing, and assembly techniques are described. Experimental measurements of the dc characteristics, forward SOA, and switching times are included. A new method of characterizing the switching performance of power transistors is proposed.

Large scale electromechanical transistor with application in mass sensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Leisheng; Li, Lijie, E-mail: L.Li@swansea.ac.uk

Nanomechanical transistor (NMT) has evolved from the single electron transistor, a device that operates by shuttling electrons with a self-excited central conductor. The unfavoured aspects of the NMT are the complexity of the fabrication process and its signal processing unit, which could potentially be overcome by designing much larger devices. This paper reports a new design of large scale electromechanical transistor (LSEMT), still taking advantage of the principle of shuttling electrons. However, because of the large size, nonlinear electrostatic forces induced by the transistor itself are not sufficient to drive the mechanical member into vibration—an external force has to bemore » used. In this paper, a LSEMT device is modelled, and its new application in mass sensing is postulated using two coupled mechanical cantilevers, with one of them being embedded in the transistor. The sensor is capable of detecting added mass using the eigenstate shifts method by reading the change of electrical current from the transistor, which has much higher sensitivity than conventional eigenfrequency shift approach used in classical cantilever based mass sensors. Numerical simulations are conducted to investigate the performance of the mass sensor.« less

Ideal Channel Field Effect Transistors

DTIC Science & Technology

2010-03-01

well as on /?-GaAs/w-GaAs homojunctions grown by molecular beam epitaxy (MBE). The diode I-Vs at reverse bias are plotted below. The measured breakdown...transistors and composite channel InAlAs/InGaAs/lnP/InAlAs high electron mobility transistors ( HEMTs ), which have taken the full advantage of the matched...result in a large number of dislocations in GaAs films epitaxially grown on wurtzite GaN. In this work, we have successfully integrated GaAs with GaN

Organic transistors manufactured using inkjet technology with subfemtoliter accuracy

PubMed Central

Sekitani, Tsuyoshi; Noguchi, Yoshiaki; Zschieschang, Ute; Klauk, Hagen; Someya, Takao

2008-01-01

A major obstacle to the development of organic transistors for large-area sensor, display, and circuit applications is the fundamental compromise between manufacturing efficiency, transistor performance, and power consumption. In the past, improving the manufacturing efficiency through the use of printing techniques has inevitably resulted in significantly lower performance and increased power consumption, while attempts to improve performance or reduce power have led to higher process temperatures and increased manufacturing cost. Here, we lift this fundamental limitation by demonstrating subfemtoliter inkjet printing to define metal contacts with single-micrometer resolution on the surface of high-mobility organic semiconductors to create high-performance p-channel and n-channel transistors and low-power complementary circuits. The transistors employ an ultrathin low-temperature gate dielectric based on a self-assembled monolayer that allows transistors and circuits on rigid and flexible substrates to operate with very low voltages. PMID:18362348

Bipolar disorder and criminal offending: a data linkage study.

PubMed

Daff, Elizabeth; Thomas, Stuart D M

2014-12-01

The current study explored criminal offending among people diagnosed with bipolar disorder with and without comorbid substance use and compared this with a community sample with no history of bipolar disorder. A case-linkage design was used to compare patterns of officially recorded criminal offending between 1,076 people with bipolar disorder drawn from a state-wide psychiatric case register with a community comparison group. Those with bipolar disorder were significantly more likely than community members to be charged with, convicted of, and be found guilty of, violent, non-violent and intermediate level criminal offences. Those with a comorbid substance use disorder were two times more likely than those without a substance use disorder to offend; both groups had a significantly higher chance of offending than the community sample. Females with bipolar disorder were significantly more likely to have been convicted of violent offences, irrespective of substance use. Significant interactions were found between bipolar disorder and substance use for males and females with respect to violent offending and for males with respect to non-violent offending. There is a statistically significant association between bipolar disorder and the likelihood of having a criminal history. Co-occurring substance use differentially impacts on the likelihood of criminal offending for males and females.

Broadening the diagnosis of bipolar disorder: benefits vs. risks

PubMed Central

STRAKOWSKI, STEPHEN M.; FLECK, DAVID E.; MAJ, MARIO

2011-01-01

There is considerable debate over whether bipolar and related disorders that share common signs and symptoms, but are currently defined as distinct clinical entities in DSM-IV and ICD-10, may be better characterized as falling within a more broadly defined “bipolar spectrum”. With a spectrum view in mind, the possibility of broadening the diagnosis of bipolar disorder has been proposed. This paper discusses some of the rationale for an expanded diagnostic scheme from both clinical and research perspectives in light of potential drawbacks. The ultimate goal of broadening the diagnosis of bipolar disorder is to help identify a common etiopathogenesis for these conditions to better guide treatment. To help achieve this goal, bipolar researchers have increasingly expanded their patient populations to identify objective biological or endophenotypic markers that transcend phenomenological observation. Although this approach has and will likely continue to produce beneficial results, the upcoming DSM-IV and ICD-10 revisions will place increasing scrutiny on psychiatry’s diagnostic classification systems and pressure to re-evaluate our conceptions of bipolar disorder. However, until research findings can provide consistent and converging evidence as to the validity of a broader diagnostic conception, clinical expansion to a dimensional bipolar spectrum should be considered with caution. PMID:21991268

[Actigraphy in Bipolar Disorder and First Degree Relatives].

PubMed

Andrade Carrillo, Rommel; Gómez Cano, Sujey; Palacio Ortiz, Juan David; García Valencia, Jenny

2015-01-01

Bipolar disorder is a disabling disease that involves a significant economic costs to the health system, making it is essential to investigate possible early predictors such as changes in sleep-wake cycle in high-risk populations. To review the available literature on alterations in the sleep-wake cycle and circadian rhythm in patients with bipolar disorder and their first degree relatives. A literature search was performed in the data bases, Access Medicine, ClinicalKey, EMBASE, JAMA, Lilacs, OVID, Oxford Journals, ScienceDirect, SciELO, APA y PsycNET. Articles in both English and Spanish were reviewed, without limits by study type. Actigraphy is a non-invasive, useful method for assessing sleep-wake cycle disturbances in the active phases of bipolar disorder, and during euthymia periods. Actigraphy showed good sensitivity to predict true sleep, but low specificity, compared with polysomnography. Although studies in bipolar offspring and relatives are scarce, they show sleep changes similar to bipolar patients. Actigraphy may be a good screening tool of sleep/wake cycle in patients with bipolar disorders, because it is economic, non-invasive and sensitive. Longitudinal studies are required to evaluate its potential use as a risk marker. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Transistors using crystalline silicon devices on glass

DOEpatents

McCarthy, Anthony M.

1995-01-01

A method for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed.

Field-effect transistors (2nd revised and enlarged edition)

NASA Astrophysics Data System (ADS)

Bocharov, L. N.

The design, principle of operation, and principal technical characteristics of field-effect transistors produced in the USSR are described. Problems related to the use of field-effect transistors in various radioelectronic devices are examined, and tables of parameters and mean statistical characteristics are presented for the main types of field-effect transistors. Methods for calculating various circuit components are discussed and illustrated by numerical examples.

Progress and challenges in bipolar lead-acid battery development

NASA Astrophysics Data System (ADS)

Bullock, Kathryn R.

1995-05-01

Bipolar lead-acid batteries have higher power densities than any other aqueous battery system. Predicted specific powers based on models and prototypes range from 800 kW/kg for 100 ms discharge times to 1.6 kW/kg for 10 s. A 48 V automotive bipolar battery could have 2 1/2 times the cold cranking rate of a monopolar 12 V design in the same size. Problems which have precluded the development of commercial bipolar designs include the instability of substrate materials and enhanced side reactions. Design approaches include pseudo-bipolar configurations, as well as true bipolar designs in planar and tubular configurations. Substrate materials used include lead and lead alloys, carbons, conductive ceramics, and tin-oxide-coated glass fibers. These approaches are reviewed and evaluated.

Microwave components for cellular portable radiotelephone

NASA Astrophysics Data System (ADS)

Muraguchi, Masahiro; Aikawa, Masayoshi

1995-09-01

Mobile and personal communication systems are expected to represent a huge market for microwave components in the coming years. A number of components in silicon bipolar, silicon Bi-CMOS, GaAs MESFET, HBT and HEMT are now becoming available for system application. There are tradeoffs among the competing technologies with regard to performance, cost, reliability and time-to-market. This paper describes process selection and requirements of cost and r.f. performances to microwave semiconductor components for digital cellular and cordless telephones. Furthermore, new circuit techniques which were developed by NTT are presented.

Three dimensional-stacked complementary thin-film transistors using n-type Al:ZnO and p-type NiO thin-film transistors.

PubMed

Lee, Ching-Ting; Chen, Chia-Chi; Lee, Hsin-Ying

2018-03-05

The three dimensional inverters were fabricated using novel complementary structure of stacked bottom n-type aluminum-doped zinc oxide (Al:ZnO) thin-film transistor and top p-type nickel oxide (NiO) thin-film transistor. When the inverter operated at the direct voltage (V DD ) of 10 V and the input voltage from 0 V to 10 V, the obtained high performances included the output swing of 9.9 V, the high noise margin of 2.7 V, and the low noise margin of 2.2 V. Furthermore, the high performances of unskenwed inverter were demonstrated by using the novel complementary structure of the stacked n-type Al:ZnO thin-film transistor and p-type nickel oxide (NiO) thin-film transistor.

Family Functioning and the Course of Adolescent Bipolar Disorder

ERIC Educational Resources Information Center

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

2012-01-01

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

A PWM transistor inverter for an ac electric vehicle drive

NASA Technical Reports Server (NTRS)

Slicker, J. M.

1981-01-01

A prototype system consisting of closely integrated motor, inverter, and transaxle has been built in order to demonstrate the feasibility of a three-phase ac transistorized inverter for electric vehicle applications. The microprocessor-controlled inverter employs monolithic power transistors to drive an oil-cooled, three-phase induction traction motor at a peak output power of 30 kW from a 144 V battery pack. Transistor safe switching requirements are discussed, and a circuit is presented for recovering trapped snubber inductor energy at transistor turn-off.

Trends in diagnosis of bipolar disorder: Have the boundaries changed?

PubMed

Sara, Grant E; Malhi, Gin S

2015-11-01

There are concerns that the diagnostic boundaries of bipolar disorder have expanded. This study seeks evidence of change in diagnostic practice at three boundaries: the 'lower' boundary with subclinical mood conditions, the 'lateral' boundary with other mental health conditions (psychotic, anxiety, substance and personality disorders) and the 'internal' boundary within affective disorders. Diagnoses recorded in health system administrative data collections were used as a measure of clinician diagnostic behaviour. We examined all diagnoses made by public (state operated) inpatient and community mental health services in New South Wales, Australia, from 2003 to 2014. A total of 31,746 people had at least one recorded diagnosis of bipolar disorder in the period. There was a significant upward trend in the age-standardised population rate of diagnosis of bipolar disorder. Bipolar disorders made up an increasing proportion of psychosis diagnoses. There was no increase in the rate of comorbid diagnosis of bipolar disorders with non-psychotic disorders or in the likelihood of diagnosis of bipolar disorder at first or subsequent episodes of depression. There were significant reductions in diagnoses of schizophrenia, particularly in younger people. There may be some increase in diagnoses of bipolar disorder in New South Wales public mental health services. However, some changes in diagnosis, particularly in younger adults, may reflect movement away from diagnoses of schizophrenia towards a range of other diagnoses, rather than specific movement towards bipolar disorder. Expansion of bipolar disorder may have been more marked in private practice settings and may have involved the poorly defined bipolar II subtype. © The Royal Australian and New Zealand College of Psychiatrists 2015.

Risk factors for suicide in bipolar disorder: a systematic review.

PubMed

Costa, Lucas da Silva; Alencar, Átila Pereira; Nascimento Neto, Pedro Januário; dos Santos, Maria do Socorro Vieira; da Silva, Cláudio Gleidiston Lima; Pinheiro, Sally de França Lacerda; Silveira, Regiane Teixeira; Bianco, Bianca Alves Vieira; Pinheiro, Roberto Flávio Fontenelle; de Lima, Marcos Antonio Pereira; Reis, Alberto Olavo Advincula; Rolim Neto, Modesto Leite

2015-01-01

Bipolar disorder confers the highest risk of suicide among major psychological disorders. The risk factors associated with bipolar disorder and suicide exist and are relevant to clinicians and researchers. The aim of the present study was to conduct a systematic review of articles regarding the suicide risk factors in bipolar disorder. A systematic review of articles on suicide risk factors in bipolar disorder, published from January 1, 2010 to April 05, 2014, on SCOPUS and PUBMED databases was carried out. Search terms were "Suicide" (medical subject headings [MeSH]), "Risk factors" (MeSH), and "Bipolar" (keyword). Of the 220 retrieved studies, 42 met the eligibility criteria. Bipolar disorder is associated with an increased rate death by suicide which contributes to overall mortality rates. Studies covered a wide range of aspects regarding suicide risk factors in bipolar disorder, such as risk factors associated to Sociodemographic conditions, Biological characteristics, Drugs Relationships, Psychological Factors, Genetic Compound, Religious and Spirituals conditions. Recent scientific literature regarding the suicide risk factors in bipolar disorder converge to, directly or indirectly, highlight the negative impacts of risk factors to the affected population quality of life. This review demonstrated that Bipolar disorders commonly leads to other psychiatric disorders and co-morbidities involving risk of suicide. Thus the risk factors are relevant to have a better diagnosis and prognosis of BD cases involving risk of suicide. Copyright © 2014 Elsevier B.V. All rights reserved.

Employment outcomes in people with bipolar disorder: a systematic review.

PubMed

Marwaha, S; Durrani, A; Singh, S

2013-09-01

Employment outcome in bipolar disorder is an under investigated, but important area. The aim of this study was to identify the long-term employment outcomes of people with bipolar disorder. A systematic review using the Medline, PsychInfo and Web of Science databases. Of 1962 abstracts retrieved, 151 full text papers were read. Data were extracted from 25 papers representing a sample of 4892 people with bipolar disorder and a mean length of follow-up of 4.9 years. Seventeen studies had follow-up periods of up to 4 years and eight follow-up of 5-15 years. Most studies with samples of people with established bipolar disorder suggest approximately 40-60% of people are in employment. Studies using work functioning measures mirrored this result. Bipolar disorder appears to lead to workplace underperformance and 40-50% of people may suffer a slide in their occupational status over time. Employment levels in early bipolar disorder were higher than in more established illness. Bipolar disorder damages employment outcome in the longer term, but up to 60% of people may be in employment. Whilst further studies are necessary, the current evidence provides support for extending the early intervention paradigm to bipolar disorder. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Characteristics of stress-coping behaviors in patients with bipolar disorders.

PubMed

Moon, Eunsoo; Chang, Jae Seung; Choi, Sungwon; Ha, Tae Hyon; Cha, Boseok; Cho, Hyun Sang; Park, Je Min; Lee, Byung Dae; Lee, Young Min; Choi, Yoonmi; Ha, Kyooseob

2014-08-15

Appropriate stress-coping strategies are needed to improve the outcome in the treatment of bipolar disorders, as stressful life events may aggravate the course of the illness. The aim of this study was to compare stress-coping behaviors between bipolar patients and healthy controls. A total of 206 participants comprising 103 bipolar patients fulfilling the Diagnostic and Statistical Manual for Axis I disorder fourth edition (DSM-IV) diagnostic criteria for bipolar I and II disorders and controls matched by age and sex were included in this study. Stress-coping behaviors were assessed using a 53-item survey on a newly-designed behavioral checklist. The characteristics of stress-coping behaviors between the two groups were compared by using t-test and factor analysis. Social stress-coping behaviors such as 'journey', 'socializing with friends', and 'talking something over' were significantly less frequent in bipolar patients than controls. On the other hand, pleasurable-seeking behaviors such as 'smoking', 'masturbation', and 'stealing' were significantly more frequent in bipolar patients than controls. These results suggest that bipolar patients may have more maladaptive stress-coping strategies than normal controls. It is recommended to develop and apply psychosocial programs to reduce maladaptive stress-coping behaviors of bipolar patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.